WorldWideScience

Sample records for wall determinants impacts

  1. Determination of arterial wall shear stress

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The arteries can remodel their structure and function to adapt themselves to the mechanical environment. In various factors that lead to vascular remodeling, the shear stress on the arterial wall induced by the blood flow is of great importance. However, there are many technique difficulties in measuring the wall shear stress directly at present. In this paper, through analyzing the pulsatile blood flow in arteries, a method has been proposed that can determine the wall shear stress quantitatively by measuring the velocity on the arterial axis, and that provides a necessary means to discuss the influence of arterial wall shear stress on vascular remodeling.

  2. Finite element simulation of barge impact into a rigid wall

    Directory of Open Access Journals (Sweden)

    H.W. Leheta

    2014-03-01

    Many approaches have been developed in order to obtain these impact loads. In general, collision mechanics for floating units is classified into, external mechanics and internal mechanics. In external mechanics, analytical approaches are used to determine the absorbed energy acting on the vessel from the collision, while in internal mechanics analytical approaches are used to determine the ability of the ship’s structure to withstand the absorbed energy. Due to the difficulty and the highly expected cost to perform model testing and impact data for validation, finite element simulation provides an alternative tool for physical validation. In this study, a simulation of barge impact to a rigid wall is presented using the explicit nonlinear finite element code LS-DYNA3D. A conventional fine mesh finite element barge model is created. Impact results are obtained at two different speeds in order to show the consequence of barge and wall damage.

  3. Bubble Impact with a Solid Wall

    Science.gov (United States)

    Garg, Vishrut; Thete, Sumeet; Basaran, Osman

    2016-11-01

    In diverse natural and industrial processes, and in particular in process equipment widely used in oil and gas production, bubbles and drops that are immersed in a continuous liquid phase frequently collide with solid walls. In this talk, the impact with a solid wall of a gas bubble that is surrounded by a liquid that is either a Newtonian or a non-Newtonian fluid is analyzed by numerical simulation. Special attention is paid to the thin film that forms between the approaching bubble and the solid wall. Flow regimes that arise as the film thickness decreases are scrutinized and rationalized by comparison of the computational predictions to well-known and new analytical results from lubrication theory based thin film literature. Finally, flow transitions that occur as the lubrication theory breaks down and inertia becomes significant are investigated.

  4. Impact of Thin-Walled Projectiles with Concrete Targets

    Directory of Open Access Journals (Sweden)

    Rayment E. Moxley

    1995-01-01

    Full Text Available An experimental program to determine the response of thin-walled steel projectiles to the impact with concrete targets was recently conducted. The projectiles were fired against 41-MPa concrete targets at an impact velocity of 290 m/s. This article contains an outline of the experimental program, an examination of the results of a typical test, and predictions of projectile deformation by classical shell theory and computational simulation. Classical shell analysis of the projectile indicated that the predicted impact loads would result in circumferential buckling. A computational simulation of a test was conducted with an impact/penetration model created by linking a rigid-body penetration trajectory code with a general-purpose finite element code. Scientific visualization of the resulting data revealed that circumferential buckling was induced by the impact conditions considered.

  5. Impact of an oblique breaking wave on a wall

    CERN Document Server

    Shu, Jian-Jun

    2014-01-01

    The intention of this paper is to study impact force of an oblique-angled slamming wave acting on a rigid wall. In the present study the analytical approach is pursued based on a technique proposed by the author. A nonlinear theory in the context of potential flow is presented for determining accurately the free-surface profiles immediately after an oblique breaking wave impingement on the rigid vertical wall that suddenly starts from rest. The small-time expansion is taken as far as necessary to include the accelerating effect. The analytical solutions for the free-surface elevation are derived up to the third order. The results derived in this paper are of particular interest to the marine and offshore engineering industries, which will find the information useful for the design of ships, coastal and offshore.

  6. Determination of arterial wall shear stress

    Institute of Scientific and Technical Information of China (English)

    LIU; Zhaorong

    2001-01-01

    [1]Langille, B. L., 7Donnell, F., Reductions in arterial diameter produced by chronic decreases in blood flow are endothelium-dependent, Science, 1986, 231: 405—407.[2]Langer, R., Vacanti, J. P., Tissue engineering, Science, 1993, 260: 920—926.[3]Kamiya, A., Togawa, T., Adaptive regulation of wall shear stress to flow change in the canine carotid artery, Am. J. Physiol. (Heart Circ. Physiol.), 1980, 239: H14—H21.[4]Fung, Y. C., Biomechanics: Motion, Flow, Stress, and Growth, New York: Springer-Verlag, 1990.[5]Liu, S. Q., Biomechanical basis of vascular tissue engineering, Critical Reviews in Biomedical Engineering, 1999, 27: 75—148.[6]Ando, J., Kamiya, A., Blood flow and vascular endothelium cell function, Frontiers Med. Biological Eng., 1993, 5: 245—264.[7]Ku, D. N., Giddens, D. P., Zarins, D. K. et al., Pulsatile flow and atherosclerosis in the human carotid bifurcation-positive correlation between plaque location and low and oscillating shear stress, Atherosclerosis, 1985, 5: 293—302.[8]Liu Zhaorong, Li Xixi, Theory and Method on Hemodynamics (in Chinese), Shanghai: Fudan University Press, 1997.

  7. Soft impact testing of a wall-floor-wall reinforced concrete structure

    Energy Technology Data Exchange (ETDEWEB)

    Vepsä, Ari, E-mail: ari.vepsa@vtt.fi; Calonius, Kim; Saarenheimo, Arja; Aatola, Seppo; Halonen, Matti

    2017-01-15

    Highlights: • A wall-floor-wall reinforced concrete structure was built. • The structure was subjected to three almost identical soft impact tests. • Response was measured with accelerometers, displacement sensors and strain gauges. • Modal tests was also carried out with the same structure in different conditions. • The results are meant to be used for validation of computational methods and models. - Abstract: Assessing the safety of the reactor building of a nuclear power plant against the crash of an airplane calls for valid computational tools such as finite element models and material constitutive models. Validation of such tools and models in turn calls for reliable and relevant experimental data. The problem is that such data is scarcely available. One of the aspects of such a crash is vibrations that are generated by the impact. These vibrations tend to propagate from the impact point to the internal parts of the building. If strong enough, these vibrations may cause malfunction of the safety-critical equipment inside the building. To enable validation of computational models for this type of behaviour, we have conducted a series of three tests with a wall-floor-wall reinforced concrete structure under soft impact loading. The response of the structure was measured with accelerometers, displacement sensors and strain gauges. In addition to impact tests, the structure was subjected to modal tests under different conditions. The tests yielded a wealth of useful data for validation of computational models and better understanding about shock induced vibration physics especially in reinforced concrete structures.

  8. Wave impact on walls with/without parapets

    Science.gov (United States)

    Frandsen, Jannette; Tremblay, Olivier; Xharde, Regis

    2015-11-01

    This work is concerned with coastline protection. The usage of vertical walls is examined for various wave trains. The effect of parapets is further studied to minimize overtopping. The results presented are based on large scale flume experiments (Quebec) with a geometric scaling of 1:4. The beach has a slope 1:10. The beach material is highly absorbing and contains a mix of sand-gravel-cobble. Steel plates are mounted locally at the beach top to eliminate effect from local scour. The critical cases found relates to the plunging breakers breaking directly impacting the wall. Entrapped air-pocket(s) under the breaking wave contribute to the run-up energy through compressibility effects and bubble burst physics even from relatively small air-pockets. Highly localized wall pressures greater than 1 MPa and 10 m run-up are easily developed even with moderate amplitude waves at the inlet. The max. peak pressure on the wall identified caused either by water or entrained air pressure is typically greater than 1 MPa occurring in the order of 0.1 ms. The pressure distributions contain either single, double or triple peaks occurring typically above/at mean flume water depth and at around the local water depth in front of the wall. Furthermore, it was identified that the cases with maximum pressure on the wall does not necessarily give the maximum jet velocity (equivalent to vertical force considered in design of parapets). This work is supported by Le ministere des Transports du Quebec, and Le ministere de la Securite publique du Quebec, Canada.

  9. Energy absorption of aluminum alloy thin-walled tubes under axial impact

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hongtu; Wang, Jian [Ludong University, Yantai (China); Shen, Guozhe; Hu, Ping [Dalian University of Technology, Dalian (China)

    2016-07-15

    Aluminum alloys are important technological materials for achieving the lightweight design of automotive structures. Many works have reported on the deformation and energy absorption of thin-walled tubes. Multicorner tubes with extra concave corners in the cross section were presented in this study to improve the energy absorption efficiency of aluminum alloy thin-walled tubes. The axial crushing of square and multicorner thin-walled tubes was simulated with the same cross-sectional perimeter. The method of folding element was applied to predict the crushing behavior of the thin-walled tubes under axial impact. The corners on the cross section were discussed to determine their effect on the energy absorption performance of thin-walled tubes. Results showed that the increasing performance of energy absorption of aluminum alloy thin-walled tubes was caused by the increasing number of corners on the cross section of multicorner tubes. Both the number and size of corners had an important effect on the crushing force efficiency of multicorner tubes. The maximum crushing force efficiency of multicorner tubes was 11.6% higher than that of square tubes with the same material consumption of thin-walled tubes. The multicorner tubes with 12 corners showed better energy absorption performance than the tubes with more than 12 corners; this high number of corners could lead to the small size of corners or unstable deformations. The high energy absorption performance of multicorner tubes prefers increasing the corner number and corner size of adjacent sides at the same time.

  10. Impact of multi-walled carbon nanotubes on aquatic species.

    Science.gov (United States)

    Asharani, P V; Serina, N G B; Nurmawati, M H; Wu, Y L; Gong, Z; Valiyaveettil, S

    2008-07-01

    To understand the environmental impacts of carbon nanotubes (CNTs), the toxicity study was carried out with water-soluble multi-walled carbon nanotubes (MWCNTs) using zebrafish (Danio rerio) as a model system. Zebrafish embryos were treated with different concentrations of MWCNTs. Teratogenic effects were evaluated through changes in embryonic development after 24 hours post-fertilization (hpf), 48 hpf and 72 hpf. No observable effect concentration (NOEC) was at 40 microg/mL. Lowest effect concentration (LOEC) of MWCNTs which caused significant phenotypic defects in zebrafish embryo was 60 microg/mL. At concentration above 60 microg/mL, slimy mucus like coating was observed around the embryo. At high concentrations, MWCNTs was found to be involved in the apoptosis, delayed hatching and formation of abnormal spinal chords. Thus, the toxicity of multi-walled carbon nanotubes is concentration dependent.

  11. Experimental Study and Numerical Simulation of Hypervelocity Projectile Impact on Double-Wall Structure

    Institute of Scientific and Technical Information of China (English)

    陈沿海; 张庆明; 黄风雷

    2004-01-01

    Tests of hypervelocity projectile impact on double-wall structure were performed with the front wall ranging from 0.5 mm to 2.0 mm thick and different impact velocities. Smooth particle hydrodynamics (SPH) code in LS-DYNA was employed for the simulation of hypervelocity impact on the double-wall structure. By using elementary shock wave theory, the experimental results above are analyzed. The analysis can provide an explanation for the penetration mechanism of hypervelocity projectile impact on double-wall structure about the effect of front wall thickness and impact velocity.

  12. Thermal Impact of Fasteners in High-Performance Wood-Framed Walls

    Energy Technology Data Exchange (ETDEWEB)

    Dane Christensen

    2011-01-01

    This paper discusses high-performance wood-framed walls that use much less than 40% of the energy consumed by similar homes built to minimum code, and evaluates the thermal impact of fasteners used to construct these walls.

  13. Modelling of radiation impact on ITER Beryllium wall

    Science.gov (United States)

    Landman, I. S.; Janeschitz, G.

    2009-04-01

    In the ITER H-Mode confinement regime, edge localized instabilities (ELMs) will perturb the discharge. Plasma lost after each ELM moves along magnetic field lines and impacts on divertor armour, causing plasma contamination by back propagating eroded carbon or tungsten. These impurities produce enhanced radiation flux distributed mainly over the beryllium main chamber wall. The simulation of the complicated processes involved are subject of the integrated tokamak code TOKES that is currently under development. This work describes the new TOKES model for radiation transport through confined plasma. Equations for level populations of the multi-fluid plasma species and the propagation of different kinds of radiation (resonance, recombination and bremsstrahlung photons) are implemented. First simulation results without account of resonance lines are presented.

  14. Anti-impact and energy-absorption of metal and compound thin-wall cylindrical tubes

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong-tao; SHEN Zhi-chun; ZHENG Gang-tie

    2008-01-01

    The paper presents an energy iterative method to determine the second critical velocity by comparing the time histories of the kinetic energy and the buckling deformation based on the finite element model of the impact system. To design anti-impact structures of the thin-wall cylindrical tubes with this new method, the cost of the experiment can be considerably reduced. The feasibility and validity of this method are demonstrated by a dropping hammer experiment. In addition, this paper deals with the influence of constrained damping layers on the anti-impact capability and energy-absorption of thin-wall cylindrical tubes. Results show that the constrained damping layers make the energy-absorption and the anti-impact capability increased comparing with the naked tubes; the thickness of the damping layer should be restricted in a range, or else the anti-impact capability will decrease with the increase of the damping layer thickness; for the constrained layer, the anti-impact capability will increase with the augment of its thickness.

  15. Preliminary study of impact fragility to RC wall subjected to aircraft impact

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Shup; Hahm, Dae Gi; Choi, In Kil [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    International experience has shown that internal and external hazards such as fires, earthquakes, and aircraft impacts can be significant safety contributors to the risk to infrastructures such as nuclear power plants. Since the aircraft accident at the World Trade Center (WTC) on September 11, 2001, an aircraft impact problem has been increasingly of the interest and is one of important categories of an unexpected external hazard field. To date, aircraft impact analyses has most focused on the response analysis to the target structures. However, this preliminary study carried out an impact fragility analysis to reinforced concrete (RC) wall subjected to an aircraft impact. The aircraft velocity is used as the important variable of this study. The impact analysis of the applied Ri era's forcing function is used by Abaqus/Explicit.

  16. Impact of Brunswick River Mouth Training Walls on Adjacent Beaches,Brunswick Heads, New South Wales, Australia

    Institute of Scientific and Technical Information of China (English)

    HUANG Hai-jun (黄海军); Andrew D. SHORT; Thomas ZENG; David HANSLOW

    2004-01-01

    River training walls have been built at scores of locations along the NSW coast and their impacts on shoreline change are still not fully understood. In this study, the Bnmswick River entrance and adjacent beaches are selected for examination of the impact of the construction of major training walls. Thirteen sets of aerial photographs taken between 1947 and 1994 are used in a GIS approach to accurately determine the shoreline position, beach contours and sand volumes, and their changes in both time and space, and then to assess the contribution of both the structures and natural hydrodynamic conditions to large scale (years-decades and kilometres) beach changes. The impact of the training walls can be divided into four stages: natural conditions prior to their construction (pre 1959), major downdrift erosion and updrift accretion during and following the construction of the walls in 1959 ~ 1962 and 1966, diminishing impact of the walls between 1966and 1987, and finally no apparent impact between 1987 ~ 1994. The impact extends horizontally about 8 km updrift and 17 km downdrift, and temporally up to 25 years.

  17. Determination of the Airborne Sound Insulation of a Straw Bale Partition Wall

    Science.gov (United States)

    Teslík, Jiří; Fabian, Radek; Hrubá, Barbora

    2017-06-01

    This paper describes the results of a scientific project focused on determining of the Airborne Sound Insulation of a peripheral non-load bearing wall made of straw bales expressed by Weighted Sound Reduction Index. Weighted Sound Reduction Index was determined by measuring in the certified acoustic laboratory at the Faculty of Mechanical Engineering at Brno University of Technology. The measured structure of the straw wall was modified in combinations with various materials, so the results include a wide range of possible compositions of the wall. The key modification was application of plaster on both sides of the straw bale wall. This construction as is frequently done in actual straw houses. The additional measurements were performed on the straw wall with several variants of additional wall of slab materials. The airborne sound insulation value has been also measured in separate stages of the construction. Thus it is possible to compare and determinate the effect of the single layers on the airborne sound insulation.

  18. Impact of turbulence anisotropy near walls in room airflow

    DEFF Research Database (Denmark)

    Schälin, A.; Nielsen, Peter Vilhelm

    2004-01-01

    for the work. The growth rate parallel to the wall in a three-dimensional wall jet is large compared with the growth rate perpendicular to the wall, and it is large compared with the growth rate in a free circular jet. It is shown that it is not possible to predict the high growth rate parallel with a surface......The influence of different turbulence models used in computational fluid dynamics predictions is studied in connection with room air movement. The turbulence models used are the high Re-number k–e model and the high Re- number Reynolds stress model (RSM). The three-dimensional wall jet is selected...... in a three- dimensional wall jet by the k–e turbulence model. Furthermore, it is shown that the growth rate can be predicted to a certain extent by the RSM with wall reflection terms. The flow in a deep room can be strongly influenced by details as the growth rate of a three-dimensional wall jet. Predictions...

  19. Violent wave impacts on vertical and inclined walls: Large scale model tests

    DEFF Research Database (Denmark)

    Obhrai, C.; Bullock, G.; Wolters, G.

    2005-01-01

    New data is presented from large scale model tests where combined measurements of wave pressure and aeration have been made on the front of a vertical and an inclined wall. The shape of the breaking wave was found to have a significant effect on the distribution of the wave impact pressures...... on the wall. The characteristics of violent wave impacts are discussed and related to the impulse on the structure....

  20. Impact of exercise training on arterial wall thickness in humans.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Cable, N.T.; Green, D.J.

    2012-01-01

    Thickening of the carotid artery wall has been adopted as a surrogate marker of pre-clinical atherosclerosis, which is strongly related to increased cardiovascular risk. The cardioprotective effects of exercise training, including direct effects on vascular function and lumen dimension, have been co

  1. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  2. MRI-based Determination of Reference Values of Thoracic Aortic Wall Thickness in a General Population

    Energy Technology Data Exchange (ETDEWEB)

    Mensel, Birger; Quadrat, Alexander; Schneider, Tobias; Kuehn, Jens-Peter; Hegenscheid, Katrin [University Medicine Greifswald, Institute of Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Doerr, Marcus [University Medicine Greifswald, Department of Internal Medicine, Greifswald (Germany); DZHK (German Center for Cardiovascular Research), Greifswald (Germany); Voelzke, Henry [University Medicine Greifswald, Institute for Community Medicine, Greifswald (Germany); DZHK (German Center for Cardiovascular Research), Greifswald (Germany); Lieb, Wolfgang [Christian Albrechts University, Institute of Epidemiology, Kiel (Germany); Lorbeer, Roberto [University Medicine Greifswald, Institute for Community Medicine, Greifswald (Germany)

    2014-09-15

    To provide age- and sex-specific reference values for MRI-derived wall thickness of the ascending and descending aorta in the general population. Data of 753 subjects (311 females) aged 21-81 years were analysed. MRI was used to determine the aortic wall thickness (AWT). Equations for reference value calculation according to age were established for females and males. Median wall thickness of the ascending aorta was 1.46 mm (5th-95th range: 1.15-1.88 mm) for females and 1.56 mm (1.22-1.99 mm) for males. Median wall thickness of the descending aorta was 1.26 mm (0.97-1.58 mm) in females and 1.36 mm (1.04-1.75 mm) in males. While median and 5th and 95th percentiles for the ascending and descending aorta increased with age in both sexes, the association between age and median AWT was stronger in males than in females for both the ascending and descending aorta. Reference values for the ascending and descending AWT are provided. In a healthy sample from the general population, the wall of the ascending aorta is thicker than the wall of the descending aorta, and both walls are thicker in males than females. The increase in wall thickness with age is greater in males. (orig.)

  3. Analysis of the effect of impact of near-wall acoustic bubble collapse micro-jet on Al 1060.

    Science.gov (United States)

    Ye, Linzheng; Zhu, Xijing

    2017-05-01

    The bubble collapse near a wall will generate strong micro-jet in a liquid environment under ultrasonic field. To explore the effect of the impact of near-wall acoustic bubble collapse micro-jet on an aluminum 1060 sheet, the cavitation threshold formula and micro-jet velocity formula were first proposed. Then the Johnson-Cook rate correlation material constitutive model was considered, and a three-dimensional fluid-solid coupling model of micro-jet impact on a wall was established and analyzed. Finally, to validate the model, ultrasonic cavitation test and inversion analysis based on the theory of spherical indentation test were conducted. The results show that cavitation occurs significantly in the liquid under ultrasonic field, as the applied ultrasonic pressure amplitude is much larger than liquid cavitation threshold. Micro pits appear on the material surface under the impact of micro-jet. Pit depth is determined by both micro-jet velocity and micro-jet diameter, and increases with their increase. Pit diameter is mainly related to the micro-jet diameter and dp/dj≈0.95-1.2, while pit's diameter-to-depth ratio is mainly negatively correlated with the micro-jet velocity. Wall pressure distribution is mostly symmetric and its maximum appears on the edge of micro-jet impingement. Obviously, the greater the micro-jet velocity is, the greater the wall pressure is. Micro pits formed after the impact of micro-jet on aluminum 1060 surface were assessed by ultrasonic cavitation test. Inversion analysis results indicate that equivalent stress, equivalent strain of the pit and impact strength, and velocity of the micro-jet are closely related with pit's diameter-to-depth ratio. For the pit's diameter-to-depth ratio of 16-68, the corresponding micro-jet velocity calculated is 310-370m/s. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Local Impact Simulation of SC Wall Structures using Aircraft Engine Projectile

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chulhun; Lee, Jungwhee; Lee, Hanjoo [Dankook Univ., Yongin (Korea, Republic of); Jung, Raeyoung; Hyun, Changhun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-05-15

    SC wall structure developed for nuclear power plant buildings consists of plain concrete and two steel plates on both surface of the concrete, while RC structure consists of re bar and concrete. SC structure has higher scabbing resistance than RC structure due to the action of steel plate on the rear side of impact. Therefore SC structure is known as more effective structure from the viewpoint of aircraft crash than RC structure. However, most of the recent researches and experiments about local impact damage deal with RC structures, and the effect of re bar and steel plate is not considered reasonably. Although Walter et al. and Make-work et al. suggested a formula for evaluating perforation depth of steel plate covered RC walls, most of the previous researches about SC structure are focused on perforation and scabbing due to the impact of hard projectile, rather than soft projectile such as an aircraft. In this research a soft projectile, i. e. aircraft engine, is utilized for impact simulation of RC and SC walls. To evaluate local damage of SC wall structures, parametric study with the variables of wall thickness and steel ratio of the cover plate is performed, and the results are compared with those of RC structures. Since scabbing was prevented by the steel plates, penetration mode of damage was observed in SC walls while scabbing damage was occurred in RC walls. It is confirmed that the rear steel plate not only contains concrete debris, but also reduces the internal damage of the concrete walls. Penetration depth of SC walls did not largely vary due to the increasing steel ratio, and similar results to RC walls were observed when the wall thickness is larger than a certain value since the impact resistance of SC wall is mainly governed by the thickness of concrete part. Therefore, it is expected that similar level of impact resistance to RC structure can be produced with the minimum thickness of steel plates of SC structure. According to these results, SC

  5. Using Mobile Learning: Determinates Impacting Behavioral Intention

    Science.gov (United States)

    Lowenthal, Jeffrey N.

    2010-01-01

    This study examined the factors or determinates that impact the behavioral intention of students to use mobile learning (m-learning) technology. These determinates include performance expectancy, effort expectancy, and self-management of learning, all mediated by age, gender, or both. Regression coefficients showed strong and significant…

  6. Using Mobile Learning: Determinates Impacting Behavioral Intention

    Science.gov (United States)

    Lowenthal, Jeffrey N.

    2010-01-01

    This study examined the factors or determinates that impact the behavioral intention of students to use mobile learning (m-learning) technology. These determinates include performance expectancy, effort expectancy, and self-management of learning, all mediated by age, gender, or both. Regression coefficients showed strong and significant…

  7. Impact of poroelasticity of intraluminal thrombus on wall stress of abdominal aortic aneurysms

    Directory of Open Access Journals (Sweden)

    Polzer Stanislav

    2012-08-01

    Full Text Available Abstract Background The predictions of stress fields in Abdominal Aortic Aneurysm (AAA depend on constitutive descriptions of the aneurysm wall and the Intra-luminal Thrombus (ILT. ILT is a porous diluted structure (biphasic solid–fluid material and its impact on AAA biomechanics is controversially discussed in the literature. Specifically, pressure measurements showed that the ILT cannot protect the wall from the arterial pressure, while other (numerical and experimental studies showed that at the same time it reduces the stress in the wall. Method To explore this phenomenon further a poroelastic description of the ILT was integrated in Finite Element (FE Models of the AAA. The AAA model was loaded by a pressure step and a cyclic pressure wave and their transition into wall tension was investigated. To this end ILT’s permeability was varied within a microstructurally motivated range. Results The two-phase model verified that the ILT transmits the entire mean arterial pressure to the wall while, at the same time, it significantly reduces the stress in the wall. The predicted mean stress in the AAA wall was insensitive to the permeability of the ILT and coincided with the results of AAA models using a single-phase ILT description. Conclusion At steady state, the biphasic ILT behaves like a single-phase material in an AAA model. Consequently, computational efficient FE single-phase models, as they have been exclusively used in the past, accurately predict the wall stress in AAA models.

  8. The quantitative estimation of the vulnerability of brick and concrete wall impacted by an experimental boulder

    Science.gov (United States)

    Zhang, J.; Guo, Z. X.; Wang, D.; Qian, H.

    2016-02-01

    There is little historic data about the vulnerability of damaged elements due to debris flow events in China. Therefore, it is difficult to quantitatively estimate the vulnerable elements suffered by debris flows. This paper is devoted to the research of the vulnerability of brick and concrete walls impacted by debris flows. An experimental boulder (an iron sphere) was applied to be the substitute of debris flow since it can produce similar shape impulse load on elements as debris flow. Several walls made of brick and concrete were constructed in prototype dimensions to physically simulate the damaged structures in debris flows. The maximum impact force was measured, and the damage conditions of the elements (including cracks and displacements) were collected, described and compared. The failure criterion of brick and concrete wall was proposed with reference to the structure characteristics as well as the damage pattern caused by debris flows. The quantitative estimation of the vulnerability of brick and concrete wall was finally established based on fuzzy mathematics and the proposed failure criterion. Momentum, maximum impact force and maximum impact bending moment were compared to be the best candidate for disaster intensity index. The results show that the maximum impact bending moment seems to be most suitable for the disaster intensity index in establishing vulnerability curve and formula.

  9. Impact of wall shear stress on initial bacterial adhesion in rotating annular reactor.

    Science.gov (United States)

    Saur, Thibaut; Morin, Emilie; Habouzit, Frédéric; Bernet, Nicolas; Escudié, Renaud

    2017-01-01

    The objective of this study was to investigate the bacterial adhesion under different wall shear stresses in turbulent flow and using a diverse bacterial consortium. A better understanding of the mechanisms governing microbial adhesion can be useful in diverse domains such as industrial processes, medical fields or environmental biotechnologies. The impact of wall shear stress-four values ranging from 0.09 to 7.3 Pa on polypropylene (PP) and polyvinyl chloride (PVC)-was carried out in rotating annular reactors to evaluate the adhesion in terms of morphological and microbiological structures. A diverse inoculum consisting of activated sludge was used. Epifluorescence microscopy was used to quantitatively and qualitatively characterize the adhesion. Attached bacterial communities were assessed by molecular fingerprinting profiles (CE-SSCP). It has been demonstrated that wall shear stress had a strong impact on both quantitative and qualitative aspects of the bacterial adhesion. ANOVA tests also demonstrated the significant impact of wall shear stress on all three tested morphological parameters (surface coverage, number of objects and size of objects) (p-values < 2.10-16). High wall shear stresses increased the quantity of attached bacteria but also altered their spatial distribution on the substratum surface. As the shear increased, aggregates or clusters appeared and their size grew when increasing the shears. Concerning the microbiological composition, the adhered bacterial communities changed gradually with the applied shear.

  10. Determination of strength behaviour of slope supported by vegetated crib walls using centrifuge model testing

    Science.gov (United States)

    Sudan Acharya, Madhu

    2010-05-01

    The crib retaining structures made of wooden/bamboo logs with live plants inside are called vegetative crib walls which are now becoming popular due to their advantages over conventional civil engineering walls. Conventionally, wooden crib walls were dimensioned based on past experiences. At present, there are several guidelines and design standards for machine finished wooden crib walls, but only few guidelines for the design and construction of vegetative log crib walls are available which are generally not sufficient for an economic engineering design of such walls. Analytical methods are generally used to determine the strength of vegetated crib retaining walls. The crib construction is analysed statically by satisfying the condition of static equilibrium with acceptable level of safety. The crib wall system is checked for internal and external stability using conventional monolithic and silo theories. Due to limitations of available theories, the exact calculation of the strength of vegetated wooden/bamboo crib wall cannot be made in static calculation. Therefore, experimental measurements are generally done to verify the static analysis. In this work, a model crib construction (1:20) made of bamboo elements is tested in the centrifuge machine to determine the strength behaviour of the slope supported by vegetated crib retaining wall. A geotechnical centrifuge is used to conduct model tests to study geotechnical problems such as the strength, stiffness and bearing capacity of different structures, settlement of embankments, stability of slopes, earth retaining structures etc. Centrifuge model testing is particularly well suited to modelling geotechnical events because the increase in gravitational force creates stresses in the model that are equivalent to the much larger prototype and hence ensures that the mechanisms of ground movements observed in the tests are realistic. Centrifuge model testing provides data to improve our understanding of basic mechanisms

  11. Sphere-Wall Impact Experiments with Piezoelectric Force Sensors

    Science.gov (United States)

    Sinko, John E.; Lassiter, Jonathan S.

    2008-04-01

    Measurement of impulse imparted to a target from μs-timescale laser ablation events is often performed with piezoelectric force sensors. For pulsed laser ablation with a target resting on the force sensors, an effect can occur for a vertical thrust stand in an exhaust-up configuration that results in measurement of about twice the actual imparted impulse. A CO2 laser operating at 10.6 μm wavelength, 300 ns pulse length, and up to 20 J pulse energy single shots was used to ablate samples of PCTFE. Force sensor measurements of the imparted impulse were compared to tests with a ballistic pendulum over a variety of fluences. The theoretical impulse delivered by the impacts of 6 mm diameter spheres of aluminum, steel, POM, and PTFE on the force sensor were studied, and the coefficients of restitution were measured for the targets. Practical issues for measurement of ablation-imparted impulse with piezoelectric sensors are discussed.

  12. Overtopping Flow Impact on a Vertical Wall on a Dike Crest

    NARCIS (Netherlands)

    Chen, X.; Hofland, B.; Altomare, C.; Uijttewaal, J.S.W.

    2014-01-01

    In this paper the impact process and mechanism of overtopping flow on a vertical wall on a dike crest are investigated by means of a series of physical model tests. A double-peaked force was recognized in a time series of an overtoping flow. Four stages were summarized for the whole overtopping flow

  13. Analysis of domain wall dynamics based on skewness of magnetic Barkhausen noise for applied stress determination

    Science.gov (United States)

    Ding, Song; Tian, GuiYun; Dobmann, Gerd; Wang, Ping

    2017-01-01

    Skewness of Magnetic Barkhausen Noise (MBN) signal is used as a new feature for applied stress determination. After experimental studies, skewness presents its ability for measuring applied tensile stress compared with conventional feature, meanwhile, a non-linear behavior of this new feature and an independence of the excitation conditions under compressive stress are found and discussed. Effective damping during domain wall motion influencing the asymmetric shape of the MBN statistical distribution function is discussed under compressive and tensile stress variation. Domain wall (DW) energy and distance between pinning edges of the DW are considered altering the characteristic relaxation time, which is the reason for the non-linear phenomenon of skewness.

  14. Daylighting and Cooling of Atrium Buildings in Warm Climates: Impact of the Top-Fenestration and Wall Mass Area.

    Science.gov (United States)

    Atif, Morad Rachid

    1992-01-01

    Sun-lighting and daylighting contribute greatly to the aesthetic value of an atrium. However, today's atria are often found either over-lit with extensive cooling loads, or under-lit requiring increased artificial lighting loads. The increase of the top-glazing area increases the cooling loads and decreases the lighting loads. The increase of the mass in the atrium walls decreases the maximum atrium temperature and the cooling loads. Furthermore, the mass distribution and its reflectance affect the lighting levels at the atrium floor. The purpose of this study is to investigate the simultaneous impact of the top-fenestration and the mass and reflectance of atrium walls on the cooling and daylighting performance of atria in warm climates. It attempts to determine the optimum top-fenestration for efficient daylighting and low cooling loads. The daylighting performance was evaluated through illumination measurements in physical models in a sky simulator. The cooling performance was evaluated using the software TRNSYS 13.1. Two types of top-fenestration were tested: horizontal and vertical south-facing, each with three alternate areas. The variations of the atrium walls included materials (standard frame and heavyweight concrete) and percentage and reflectance of the solid area. Two and four-story atria were considered, each with square and linear configuration. The performance was evaluated for three warm climates. The optimum top-fenestration for efficient daylighting was determined. The daylighting prediction algorithm was extended to include the effective reflectance of the atrium walls. The increase of mass in the atrium walls significantly decreased the atrium temperature range, the maximum atrium temperature, and the cooling loads. This impact decreased from horizontal to vertical south-facing top-glazing. The vertical south-facing top-glazing and, to a lesser degree, the reduction of the glazed atrium cover by 50% had more cooling benefits than increasing the

  15. Monitoring of Refractory Wall recession using high temperature impact echo instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    University of Dayton

    2004-04-30

    Regression of refractory linings of furnaces occurs due to a variety of mechanisms. The specific mechanism selected for investigation during this program is the regression of refractories which are in direct contact with a liquid corrodant. Examples include the melting of glass, the production of pig iron and steel, and the melting of aluminum. The rates of regression to a wall thickness which requires reline or extensive reconstruction vary widely, from less than a year to over ten years depending on the specific service environment. This program investigated the feasibility of measuring refractory wall thickness with an impact-echo method while at operating temperature (wall temperatures exceeding 500 C). The impact-echo method uses the impact of a small sphere with the surface of the test object to send a stress wave into the object. In a plate-like structure, the stress wave reflects back to the front surface, reverberating in the structure and causing a periodic surface displacement whose frequency is inversely proportional to the thickness of the test object. Impact-echo testing was chosen because it requires access to only one side of the test object and could be performed during the operation of a refractory structure. Commercially-available impact-echo instrumentation is available for room temperature use for a variety of tests on concrete. The enabling technology for this work was to use a high-temperature piezoelectric material, aluminum nitride, as the receiving sensor for the stress waves, allowing its use on refractories during furnace operation.

  16. Determining the Sub-Cellular Localization of Proteins within Caenorhabditis elegans Body Wall Muscle

    Science.gov (United States)

    Viveiros, Ryan; Warner, Adam; Plastino, Lorena; Lorch, Adam; Granger, Laure; Segalat, Laurent; Moerman, Donald G.

    2011-01-01

    Determining the sub-cellular localization of a protein within a cell is often an essential step towards understanding its function. In Caenorhabditis elegans, the relatively large size of the body wall muscle cells and the exquisite organization of their sarcomeres offer an opportunity to identify the precise position of proteins within cell substructures. Our goal in this study is to generate a comprehensive “localizome” for C. elegans body wall muscle by GFP-tagging proteins expressed in muscle and determining their location within the cell. For this project, we focused on proteins that we know are expressed in muscle and are orthologs or at least homologs of human proteins. To date we have analyzed the expression of about 227 GFP-tagged proteins that show localized expression in the body wall muscle of this nematode (e.g. dense bodies, M-lines, myofilaments, mitochondria, cell membrane, nucleus or nucleolus). For most proteins analyzed in this study no prior data on sub-cellular localization was available. In addition to discrete sub-cellular localization we observe overlapping patterns of localization including the presence of a protein in the dense body and the nucleus, or the dense body and the M-lines. In total we discern more than 14 sub-cellular localization patterns within nematode body wall muscle. The localization of this large set of proteins within a muscle cell will serve as an invaluable resource in our investigation of muscle sarcomere assembly and function. PMID:21611156

  17. Effects of Moat Wall Impact on the Seismic Response of Base Isolated Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Kyu; Kim, Jung Han [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Mosqueda, Gilberto; Sarebanhab, Alireza [University of California, San Diego (United States)

    2015-10-15

    The objectives of this study are to examine the effects of impact on the response of seismically isolated NPPs and identify characteristics of the isolation hardware and hard stop that minimize these effects. Considering variable distances to the hard stop and properties of the moat wall, the amplification in response is reported for acceleration and floor spectral accelerations at different points along the height of a NPP containment structure. Base isolation can be an effective strategy to protect critical facilities such as Nuclear Power Plants (NPPs) from the damaging effects of horizontal earthquake ground shaking. To be effective in reducing accelerations and deformations of the structure above, the seismic isolation bearings can be subjected to large displacements. In the case of an extreme earthquake, bearing displacements need to be limited by a hard stop in order to prevent failure of the bearings. Impact to the hard stop, which is often the moat wall at the basement level, is also of significant concern due to the potential for increased transfer of forces and amplification in response of the structural system, piping and other contents. However, the consequences of impact or factors important to mitigate its effects are not very well understood. The main findings of this study are related to modeling of NPP with moat wall in OpenSees and LSDyna as well as observations resulting from the parametric study of the performance of the NPP under different intensity levels of seismic excitations for different properties of the moat wall and bearings. • Variation in the isolator properties should be considered when examining seismic pounding. For BDBE even, 58.5 % cases result to the impact for lower bound properties while this value was 5.5 % for upper bound properties. Since the impact results are dependent to the assumed bearing properties, a better range of properties can be obtained from experimental testing of the bearing under large shear strains.

  18. OBLIQUE WATER WAVES IMPACTING ON A THIN POROUS WALL WITH A PARTIAL-SLIPPING BOUNDARY CONDITION

    Institute of Scientific and Technical Information of China (English)

    HSU Hao-Jen; HUANG Liang-Hsiung

    2011-01-01

    When an incoming water wave is parallel to a porous breakwater, a paradoxical phenomenon exists in that by strictly following the potential flow boundary condition of normal flux continuity on the interfaces, the water wave permeates the wall completely, regardless of breakwater porosity. To account for this paradoxical phenomenon when solving the problem of water waves obliquely impacting on a thin porous wall, a new partial-slipping boundary condition on the thin porous wall for potential flow is proposed. Analytical results show that when the water wave is parallel to a thin porous wall (i.e., the incident angle equals to 90°),the transmitted wave side remains quiescent, i.e., the transmitted wave side does not capture any wave energy when no viscous effect exists. This reveals that the above-mentioned paradoxical phenomenon disappears. The viscous boundary layer effect is also investigated in this study, which provides proper boundary conditions on a thin porous wall for viscous flows and detailed flow information.

  19. Technical Note: The determination of enclosed water volume in large flexible-wall mesocosms "KOSMOS"

    Directory of Open Access Journals (Sweden)

    J. Czerny

    2013-03-01

    Full Text Available The volume of water enclosed inside flexible-wall mesocosm bags is hard to estimate using geometrical calculations and can be strongly variable among bags of the same dimensions. Here we present a method for precise water volume determination in mesocosms using salinity as a tracer. Knowledge of the precise volume of water enclosed allows establishment of exactly planned treatment concentrations and calculation of elemental budgets.

  20. Optimizing and slope determination of final wall for Maiduk Mine with consideration of destabilizer factors

    Institute of Scientific and Technical Information of China (English)

    Shamsoddin Saeed Masoud; Maarefvand Parviz; Yaaghubi Ebrahim

    2016-01-01

    In this research, determination of final slope for Maiduk copper mine of Kerman is investigated according to destabilizing factors of the mine. The development of the Maiduk Mine caused the extension of the mine area and also withdrawal of its wall. So, optimizing possibility of mine slope is essential. Finally, the magnitude of optimized slopes for different walls of the mine in association with executive com-mands with better factors of safety is provided. The results show that the most important destabilizer factors are the presence of water and pore pressure in the faults and the main joints. With the omission of pore pressure, mine wall for the designed depth is quite stable. This requires a drainage pattern in the lifetime of the mine. In an optimistic point of view, the minimum factor of safety of the wall will be 2.81 even without drainage. This conclusion allows optimizing the slope to its maximum magnitude of 51 degree. With the pessimistic engineering judgment and with the higher SF, the magnitude of the slope is optimized to 47 degree.

  1. On the Dynamic Behavior of a Liquid Droplet Impacting upon a Wall Having Obstacles

    Directory of Open Access Journals (Sweden)

    Boseon Kang

    2015-01-01

    Full Text Available In this paper, the effects of a step edge and a stationary droplet on the dynamic behavior of a droplet impacting upon a wall are experimentally studied. The main parameters were the distance from the step edge to the center of the impacting droplet and the center-to-center distance between the stationary and impacting droplets. Photographic images showed the coalescence dynamics, shape evolution and contact line movement of the impacting droplet. The spread length is presented for the step edge and two coalescing droplets. The droplets exhibited much different dynamic behavior depending on the location of the step edge. The momentum of the impacting droplet was better transferred to the stationary droplet as the center-to-center distance between the two droplets was reduced, resulting in more spreading of the coalescing droplet.

  2. Simplified Dynamic Structural Time History Response Analysis of Flexible Approach Walls Founded on Clustered Pile Groups Using Impact_Deck

    Science.gov (United States)

    2016-07-01

    The user assigns a fixed ERDC/ITL TR-16-1 243 damping ratio and Impact_Deck estimates the natural frequencies and calculate the coefficients...for a similar structure. ERDC/ITL TR-16-1 244 I.4 Flexible Wall frequency estimates For the flexible wall problem specified in Appendix C...Impact_Deck example problem . .......................... 39 Table 2.4 Extreme forces/moments for the Impact_Deck example problem

  3. Experimental determination of excitonic band structures of single-walled carbon nanotubes using circular dichroism spectra.

    Science.gov (United States)

    Wei, Xiaojun; Tanaka, Takeshi; Yomogida, Yohei; Sato, Naomichi; Saito, Riichiro; Kataura, Hiromichi

    2016-10-05

    Experimental band structure analyses of single-walled carbon nanotubes have not yet been reported, to the best of our knowledge, except for a limited number of reports using scanning tunnelling spectroscopy. Here we demonstrate the experimental determination of the excitonic band structures of single-chirality single-walled carbon nanotubes using their circular dichroism spectra. In this analysis, we use gel column chromatography combining overloading selective adsorption with stepwise elution to separate 12 different single-chirality enantiomers. Our samples show higher circular dichroism intensities than the highest values reported in previous works, indicating their high enantiomeric purity. Excitonic band structure analysis is performed by assigning all observed Eii and Eij optical transitions in the circular dichroism spectra. The results reproduce the asymmetric structures of the valence and conduction bands predicted by density functional theory. Finally, we demonstrate that an extended empirical formula can estimate Eij optical transition energies for any (n,m) species.

  4. Experimental determination of excitonic band structures of single-walled carbon nanotubes using circular dichroism spectra

    Science.gov (United States)

    Wei, Xiaojun; Tanaka, Takeshi; Yomogida, Yohei; Sato, Naomichi; Saito, Riichiro; Kataura, Hiromichi

    2016-10-01

    Experimental band structure analyses of single-walled carbon nanotubes have not yet been reported, to the best of our knowledge, except for a limited number of reports using scanning tunnelling spectroscopy. Here we demonstrate the experimental determination of the excitonic band structures of single-chirality single-walled carbon nanotubes using their circular dichroism spectra. In this analysis, we use gel column chromatography combining overloading selective adsorption with stepwise elution to separate 12 different single-chirality enantiomers. Our samples show higher circular dichroism intensities than the highest values reported in previous works, indicating their high enantiomeric purity. Excitonic band structure analysis is performed by assigning all observed Eii and Eij optical transitions in the circular dichroism spectra. The results reproduce the asymmetric structures of the valence and conduction bands predicted by density functional theory. Finally, we demonstrate that an extended empirical formula can estimate Eij optical transition energies for any (n,m) species.

  5. Calculation of Ground State Rotational Populations for Kinetic Gas Homonuclear Diatomic Molecules including Electron-Impact Excitation and Wall Collisions

    Energy Technology Data Exchange (ETDEWEB)

    David R. Farley

    2010-08-19

    A model has been developed to calculate the ground-state rotational populations of homonuclear diatomic molecules in kinetic gases, including the effects of electron-impact excitation, wall collisions, and gas feed rate. The equations are exact within the accuracy of the cross sections used and of the assumed equilibrating effect of wall collisions. It is found that the inflow of feed gas and equilibrating wall collisions can significantly affect the rotational distribution in competition with non-equilibrating electron-impact effects. The resulting steady-state rotational distributions are generally Boltzmann for N≥3, with a rotational temperature between the wall and feed gas temperatures. The N=0,1,2 rotational level populations depend sensitively on the relative rates of electron-impact excitation versus wall collision and gas feed rates.

  6. Quantitative Assessment of Wall Shear Stress in an Aortic Coarctation - Impact of Virtual Interventions

    Science.gov (United States)

    Karlsson, Matts; Andersson, Magnus; Lantz, Jonas

    2014-11-01

    Turbulent and wall impinging blood flow causes abnormal shear forces onto the lumen and may play an important role in the pathogenesis of numerous cardiovascular diseases. In the present study, wall shear stress (WSS) and related flow parameters were studied in a pre-treated aortic coarctation (CoA) as well as after several virtual interventions using computational fluid dynamics (CFD). Patient-specific geometry and flow conditions were derived from magnetic resonance imaging (MRI) data. Finite element analysis was performed to acquire six different dilated CoAs. The unsteady pulsatile flow was resolved by large eddy simulation (LES) including non-Newtonian blood rheology. Pre-intervention, the presence of jet flow wall impingement caused an elevated WSS zone, with a distal region of low and oscillatory WSS. After intervention, cases with a more favorable centralized jet showed reduced high WSS values at the opposed wall. Despite significant turbulence reduction post-treatment, enhanced regions of low and oscillatory WSS were observed for all cases. This numerical method has demonstrated the morphological impact on WSS distribution in an CoA. With the predictability and validation capabilities of a combined CFD/MRI approach, a step towards patient-specific intervention planning is taken.

  7. Determination of shear parameters of concrete filled head-straight masonry brick walls

    Directory of Open Access Journals (Sweden)

    Reza Amiraslanzadeh

    2015-03-01

    Full Text Available The aim of present study was determination of shear parameters of reinforced and unreinforced masonry brick walls assembled with Head-straight texture order. Experimental tests carried out on triplets in order to define shear parameters of brick mortar interface, and diagonal compression test in order to define shear strength of masonry panels. According to various interpretations on evaluation of shear strength using diagonal compression test, comparison between mentioned values and those obtained by laboratory tests on shear triplets are presented. The results showed that, although the generated internal columns have not been tied together on top and bottom sides, they contributed to a significant improvement on shear resistance of the masonry panels. Referring to the interpretations on test outcomes, it was perceived that the formula which was obtained by adopting the Turnašek- Cacovic criterion is the most suitable and reliable one. It was concluded that filling the voids of Head-straight texture masonry walls using steel fiber concrete, significantly increase these walls shear parameters.

  8. X-ray crystallography and its impact on understanding bacterial cell wall remodeling processes.

    Science.gov (United States)

    Büttner, Felix Michael; Renner-Schneck, Michaela; Stehle, Thilo

    2015-02-01

    The molecular structure of matter defines its properties and function. This is especially true for biological macromolecules such as proteins, which participate in virtually all biochemical processes. A three dimensional structural model of a protein is thus essential for the detailed understanding of its physiological function and the characterization of essential properties such as ligand binding and reaction mechanism. X-ray crystallography is a well-established technique that has been used for many years, but it is still by far the most widely used method for structure determination. A particular strength of this technique is the elucidation of atomic details of molecular interactions, thus providing an invaluable tool for a multitude of scientific projects ranging from the structural classification of macromolecules over the validation of enzymatic mechanisms or the understanding of host-pathogen interactions to structure-guided drug design. In the first part of this review, we describe essential methodological and practical aspects of X-ray crystallography. We provide some pointers that should allow researchers without a background in structural biology to assess the overall quality and reliability of a crystal structure. To highlight its potential, we then survey the impact X-ray crystallography has had on advancing an understanding of a class of enzymes that modify the bacterial cell wall. A substantial number of different bacterial amidase structures have been solved, mostly by X-ray crystallography. Comparison of these structures highlights conserved as well as divergent features. In combination with functional analyses, structural information on these enzymes has therefore proven to be a valuable template not only for understanding their mechanism of catalysis, but also for targeted interference with substrate binding.

  9. Numerical study on energy absorbing characteristics of thin-walled tube under axial and oblique impact

    Directory of Open Access Journals (Sweden)

    V. Santhosh kumar

    2016-03-01

    Full Text Available Energy absorbing characteristics (EAC of thin wall tube during the impact are important in the automobile and aerospace industries. In this paper, energy absorbing characteristics such as mean force, peak force, energy absorption and crash force efficiency (CFE of three different cross-sections (square, rectangular and circular at three different thicknesses (2 mm, 2.5 mm and 4 mm were analyzed. The analysis was accomplished using ABAQUS/EXPLICIT, and aluminum alloy (AA6063 was used as a shell material. The result of impact (or crash-worthiness against axial load indicates that the circular cross section of 2.5 mm thickness is optimum. During the oblique (15°, 30°, 45° impact, increasing the angle leads to less energy absorption. Also, Multilinear regression analysis was carried out to predict the energy absorption characteristics at 90°.

  10. Determination of Optimum Window to External Wall Ratio for Offices in a Hot and Humid Climate

    Directory of Open Access Journals (Sweden)

    Halil Alibaba

    2016-02-01

    Full Text Available Heat loss and gain through windows has a very high impact on the thermal comfort of offices. This paper analyzes a standard low energy consumption university office that has a standard envelope. Dynamic thermal simulations with EDSL Tas software, a predicted mean vote (PMV, and a predicted percentage of dissatisfied (PPD with all local discomfort as stated in ASHRAE, ISO 7730: 2005, EN 15251: 2007 were used for thermal sensation, in order to optimize the best window to external wall proportion in a hot and humid climate that exists in the Famagusta case study. A simulated office building is oriented east to west in order to take advantage of the wind direction. In May 45% (PPD < 6%–0.7% open window, 93% (PPD < 10–0.2 open window, and 97% (PPD < 15%–0.1% open window thermal comfort scores are obtained when the window to external wall ratio (WWR is 10%. In October 43% (PPD < 6%–0.7% open window, 86% (PPD < 10–0.2 open window, and 92% (PPD < 15%–0.1% open window thermal comfort scores are obtained when the WWR is 10%. In September 49% (PPD < 10% full open window and 51% (PPD < 15%–0.1% open window thermal comfort scores are obtained when the WWR is 10%.

  11. Impact of lithium on the plasma performance in the all-metal-wall tokamak ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Lang, P.T.; Moreno Quicios, R.; Arredondo Parra, R.; Ploeckl, B.; McDermott, R.; Neu, R.; Wolfrum, E. [MPI fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Maingi, R.; Mansfield, D.K.; Diallo, A. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Collaboration: ASDEX Upgrade Team

    2016-07-01

    Several tokamaks reported improvement in key plasma parameters concurrent with the presence of lithium in the plasma. At ASDEX Upgrade explorative experiments have been performed to find out if such effects can be observed when operating with an all-metal-wall. A gas gun launcher was developed capable to inject pellets containing about 1.6 x 10{sup 20} Li atoms at 2 Hz. The speed of about 600 m/s is sufficient to achieve core penetration and to create a homogeneous Li concentration of up to 10 %. With a typical sustainment time on the order of 100 ms, only transient Li presence without any pile up was achieved. Deposition of Li on plasma facing components, which remained for several discharges after injection, was observed. This short lived wall conditioning showed beneficial effects during plasma start-up. However, the accompanying surface contamination negatively impacted some diagnostics. The Li impact on the confinement was investigated in a dedicated plasma scenario with a proven sensitivity to nitrogen and helium. In phases with N seeding enhancing the confinement by about 30 %, Li injection resulted in a very modest, transient loss of confinement (about 5 %). No Li impact was found for pure Deuterium plasmas.

  12. Free surface flow impact on a vertical wall: a numerical assessment

    Science.gov (United States)

    Pugliese Carratelli, Eugenio; Viccione, Giacomo; Bovolin, Vittorio

    2016-10-01

    The sudden impact of a free surface flow upon a solid wall is a common occurrence in many situations in nature and technology. The design of marine structures is probably the most obvious example, but also river and dam hydraulics as well as the necessity of understanding flood and debris flow-induced damage have led to theoretical and experimental work on the mechanism of fluid slamming loads. This is therefore a very old and rich research field, which has not yet reached full maturity, so that semi-empirical methods in design practice are still the rule in many sectors. Up-to-date CFD technology with both Eulerian and Lagrangian approaches is employed to investigate highly non-stationary fluid impact on a solid wall. The development of the pressure wave produced by the impact is examined as it propagates and interacts with the fluid boundaries, as well as the subsequent build-up of high-pressure gradients of high fluid velocities. The geometry and the velocity field of the problem considered are very simple, but the results seem to provide new insight, in particular, into the connection between phenomena with different timescales.

  13. Environmental Impacts from Photovoltaic Solar Cells Made with Single Walled Carbon Nanotubes.

    Science.gov (United States)

    Celik, Ilke; Mason, Brooke E; Phillips, Adam B; Heben, Michael J; Apul, Defne S

    2017-02-24

    An ex-ante life cycle inventory was developed for single walled carbon nanotube (SWCNT) PV cells, including a laboratory-made 1 % efficient device and an aspirational 28 % efficient four-cell tandem device. The environmental impact of unit energy generation from the mono-Si PV technology was used as a reference point. Compared to monocrystalline Si (mono-Si), the environmental impacts from 1% SWCNT was ~18 times higher due mainly to the short lifetime of three years. However, even with the same short lifetime, the 28% cell had lower environmental impacts than mono-Si. The effects of lifetime and efficiency on the environmental impacts were further examined. This analysis showed that if the SWCNT device efficiency had the same value as the best efficiency of the material under comparison, to match the total normalized impacts of the mono- and poly-Si, CIGS, CdTe, and a-Si devices, the SWCNT devices would need a lifetime of 2.8, 3.5, 5.3, 5.1, and 10.8 years, respectively. It was also found that if the SWCNT PV has an efficiency of 4.5 % or higher, its energy payback time would be lower than other existing and emerging PV technologies. The major impacts of SWCNT PV came from the cell's materials synthesis.

  14. NUMERICAL INVESTIGATION ON MUD BED-GENERATION AND IMPACTING A WALL ALONG A SLOPE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper mud was treated as the Bingham fluid. In staggered grids, two-dimensional incompressible Navier-Stokes equations for non-Newtonian fluid was solved by the MAC method. Numerical simulations were conducted on mud bed-generating phenomenon and mud impacting a wall along a slope. The distributions of free surface, pressure and velocity of mud and water were obtained. The results indicate that the computed layer thickness of mud bed almost equals the theoretically predicted value. Because of the differences in constitutive relationship, the distributions of free surface are different for water and mud. The distortion of water free surface is much more complicated.

  15. Impact of current on static and kinetic depinning fields of domain wall in ferromagnetic nanostrip

    Indian Academy of Sciences (India)

    R Arun; P Sabareesan; M Daniel

    2015-11-01

    The impact of current on static and kinetic depinning fields of a domain wall in a onedimensional ferromagnetic nanostrip is investigated analytically and numerically by solving the Landau–Lifshitz–Gilbert equation with adiabatic and non-adiabatic spin-transfer torques. The results show that in the absence of current, the static depinning field is greater than the kinetic depinning field. Both the depinning fields decrease by increasing the current applied in a direction opposite to the direction of the applied field. Both the depinning fields can also be tuned by the current to make them equal.

  16. Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture.

    Science.gov (United States)

    Turner, Robert D; Hurd, Alexander F; Cadby, Ashley; Hobbs, Jamie K; Foster, Simon J

    2013-01-01

    Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan, the target of antibiotics essential in modern healthcare. It consists of glycan strands, cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to turgor pressure and yet remains dynamic to allow insertion of new material, and hence growth. The cellular architecture and insertion pattern of peptidoglycan have remained elusive. Here we determine the peptidoglycan architecture and dynamics during growth in rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented bands of material interspersed with a more porous network. Super-resolution fluorescence microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present a consolidated model of growth via architecture-regulated insertion, where we propose only the more porous regions of the peptidoglycan network that are permissive for synthesis.

  17. Determining the Business Impact of Knowledge Management

    Science.gov (United States)

    Aaron, Bruce C.

    2009-01-01

    This case study describes an evaluation of business impact and return on investment (ROI) for the Knowledge Exchange, a knowledge management (KM) system within Accenture. The evaluation used a continuous measurement design to allow impact and ROI to be tracked across time and groups. The results demonstrated a significant positive impact on…

  18. Determining the Business Impact of Knowledge Management

    Science.gov (United States)

    Aaron, Bruce C.

    2009-01-01

    This case study describes an evaluation of business impact and return on investment (ROI) for the Knowledge Exchange, a knowledge management (KM) system within Accenture. The evaluation used a continuous measurement design to allow impact and ROI to be tracked across time and groups. The results demonstrated a significant positive impact on…

  19. Impact of wall hydrophobicity on condensation flow and heat transfer in silicon microchannels

    Science.gov (United States)

    Fang, Chen; Steinbrenner, Julie E.; Wang, Fu-Min; Goodson, Kenneth E.

    2010-04-01

    While microchannel condensation has been the subject of several recent studies, the critical impact of wall hydrophobicity on the microchannel condensation flow has received very little attention. The paper experimentally studies steam condensation in a silicon microchannel 286 µm in hydraulic diameter with three different wall hydrophobicities. It is found that the channel surface wettability has a significant impact on the flow pattern, pressure drop and heat transfer characteristic. Spatial flow pattern transition is observed in both hydrophobic and hydrophilic channels. In the hydrophobic channel, the transition from dropwise/slugwise flow to plug flow is induced by the slug instability. In the hydrophilic channel, the flow transition is characterized by the periodic bubble detachment, a process in which pressure evolution is found important. Local temperature measurement is conducted and heat flux distribution in the microchannel is reconstructed. For the same inlet vapor flux and temperature, the hydrophobic microchannel yields higher heat transfer rate and pressure drop compared to the hydrophilic channel. The difference is attributed to the distinction in flow pattern and heat transfer mechanism dictated by the channel hydrophobicity. This study highlights the importance of the channel hydrophobicity control for the optimization of the microchannel condenser.

  20. Impact of flame-wall interaction on premixed flame dynamics and transfer function characteristics

    KAUST Repository

    Kedia, K.S.

    2011-01-01

    In this paper, we numerically investigate the response of a perforated-plate stabilized laminar methane-air premixed flame to imposed inlet velocity perturbations. A flame model using detailed chemical kinetics mechanism is applied and heat exchange between the burner plate and the gas mixture is incorporated. Linear transfer functions, for low mean inlet velocity oscillations, are analyzed for different equivalence ratio, mean inlet velocity, plate thermal conductivity and distance between adjacent holes. The oscillations of the heat exchange rate at the top of the burner surface plays a critical role in driving the growth of the perturbations over a wide range of conditions, including resonance. The flame response to the perturbations at its base takes the form of consumption speed oscillations in this region. Flame stand-off distance increases/decreases when the flame-wall interaction strengthens/weakens, impacting the overall dynamics of the heat release. The convective lag between the perturbations and the flame base response govern the phase of heat release rate oscillations. There is an additional convective lag between the perturbations at the flame base and the flame tip which has a weaker impact on the heat release rate oscillations. At higher frequencies, the flame-wall interaction is weaker and the heat release oscillations are driven by the flame area oscillations. The response of the flame to higher amplitude oscillations are used to gain further insight into the mechanisms. © 2010 Published by Elsevier Inc. on behalf of The Combustion Institute. All rights reserved.

  1. The impact of alterations in the lignin biosynthetic pathway on molecular architecture of the plant cell wall

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiliang; Kim, Jeong IM; Cusumano, J C; Chapple, C; Venugopalan, Nagarajan; Fischetti, Robert F.; Makowski, Lee

    2016-06-17

    Background: Coordination of synthesis and assembly of the polymeric components of cell walls is essential for plant growth and development. Given the degree of co-mingling and cross-linking among cell wall components, cellulose organization must be dependent on the organization of other polymers such as lignin. Here we seek to identify aspects of that codependency by studying the structural organization of cellulose fibrils in stems from Arabidopsis plants harboring mutations in genes encoding enzymes involved in lignin biosynthesis. Plants containing high levels of G-lignin, S-lignin, H-lignin, aldehyde-rich lignin, and ferulic acid-containing lignin, along with plants with very low lignin content were grown and harvested and longitudinal sections of stem were prepared and dried. Scanning X-ray microdiffraction was carried out using a 5-micron beam that moved across the sections in 5-micron steps and complete diffraction patterns were collected at each raster point. Approximately, 16,000 diffraction patterns were analyzed to determine cellulose fibril orientation and order within the tissues making up the stems. Results: Several mutations-most notably those exhibiting (1) down-regulation of cinnamoyl CoA reductase which leads to cell walls deficient in lignin and (2) defect of cinnamic acid 4-hydroxylase which greatly reduces lignin content-exhibited significant decrease in the proportion of oriented cellulose fibrils in the cell wall. Distinctions between tissues were maintained in all variants and even in plants exhibiting dramatic changes in cellulosic order the trends between tissues (where apparent) were generally maintained. The resilience of cellulose to degradative processes was investigated by carrying out the same analysis on samples stored in water for 30 days prior to data collection. This treatment led to significant loss of cellulosic order in plants rich in aldehyde or H-lignin, less change in wild type, and essentially no change in samples with

  2. Shear velocity and wall position determination from particle image velocimetry data with seed centroid correction

    Science.gov (United States)

    Harris, Jeff; Lance, Blake; Skifton, Richard; Smith, Barton

    2015-11-01

    Two methods of computing the wall shear velocity from high-resolution particle image velocimetry (PIV) measurements are compared with and without a correction that accounts for seed gradient near the wall. It is crucial to know the wall position when computing the wall shear stress, but this can be difficult due to laser scatter on a wall. Furthermore, PIV is well known to be biased near walls due to seeding gradients. We compensate for these effects by replacing the cross-stream location of each vector with a value based on the centroid of the seeding in each interrogation region. The shear velocity and wall position resulting from methods outlined in the literature are presented. The boundary layer cases presented are influenced by buoyancy and the efficacy of these methods for convective flow will be discussed.

  3. Determination of wall tension in cerebral artery aneurysms by numerical simulation

    DEFF Research Database (Denmark)

    Isaksen, J.G.; Bazilevs, Y.; Kvamsdal, T.

    2008-01-01

    BACKGROUND AND PURPOSE: Cerebral artery aneurysms rupture when wall tension exceeds the strength of the wall tissue. At present, risk-assessment of unruptured aneurysms does not include evaluation of the lesions shape, yet clinical experience suggests that this is of importance. We aimed to develop...... a computational model for simulation of fluid-structure interaction in cerebral aneurysms based on patient specific lesion geometry, with special emphasis on wall tension. METHODS: An advanced isogeometric fluid-structure analysis model incorporating flexible aneurysm wall based on patient specific computed...... tomography angiogram images was developed. Variables used in the simulation model were retrieved from a literature review. RESULTS: The simulation results exposed areas of high wall tension and wall displacement located where aneurysms usually rupture. CONCLUSIONS: We suggest that analyzing wall tension...

  4. Additional double-wall roof in single-wall, closed, convective incubators: Impact on body heat loss from premature infants and optimal adjustment of the incubator air temperature.

    Science.gov (United States)

    Delanaud, Stéphane; Decima, Pauline; Pelletier, Amandine; Libert, Jean-Pierre; Stephan-Blanchard, Erwan; Bach, Véronique; Tourneux, Pierre

    2016-09-01

    Radiant heat loss is high in low-birth-weight (LBW) neonates. Double-wall or single-wall incubators with an additional double-wall roof panel that can be removed during phototherapy are used to reduce Radiant heat loss. There are no data on how the incubators should be used when this second roof panel is removed. The aim of the study was to assess the heat exchanges in LBW neonates in a single-wall incubator with and without an additional roof panel. To determine the optimal thermoneutral incubator air temperature. Influence of the additional double-wall roof was assessed by using a thermal mannequin simulating a LBW neonate. Then, we calculated the optimal incubator air temperature from a cohort of human LBW neonate in the absence of the additional roof panel. Twenty-three LBW neonates (birth weight: 750-1800g; gestational age: 28-32 weeks) were included. With the additional roof panel, R was lower but convective and evaporative skin heat losses were greater. This difference can be overcome by increasing the incubator air temperature by 0.15-0.20°C. The benefit of an additional roof panel was cancelled out by greater body heat losses through other routes. Understanding the heat transfers between the neonate and the environment is essential for optimizing incubators.

  5. Desorption of 1,3,5-Trichlorobenzene from Multi-Walled Carbon Nanotubes: Impact of Solution Chemistry and Surface Chemistry

    Directory of Open Access Journals (Sweden)

    Sheikh Uddin

    2013-05-01

    Full Text Available The strong affinity of carbon nanotubes (CNTs to environmental contaminants has raised serious concern that CNTs may function as a carrier of environmental pollutants and lead to contamination in places where the environmental pollutants are not expected. However, this concern will not be realized until the contaminants are desorbed from CNTs. It is well recognized that the desorption of environmental pollutants from pre-laden CNTs varies with the environmental conditions, such as the solution pH and ionic strength. However, comprehensive investigation on the influence of solution chemistry on the desorption process has not been carried out, even though numerous investigations have been conducted to investigate the impact of solution chemistry on the adsorption of environmental pollutants on CNTs. The main objective of this study was to determine the influence of solution chemistry (e.g., pH, ionic strength and surface functionalization on the desorption of preloaded 1,3,5-trichlorobenzene (1,3,5-TCB from multi-walled carbon nanotubes (MWNTs. The results suggested that higher pH, ionic strength and natural organic matter in solution generally led to higher desorption of 1,3,5-TCB from MWNTs. However, the extent of change varied at different values of the tested parameters (e.g., pH 7. In addition, the impact of these parameters varied with MWNTs possessing different surface functional groups, suggesting that surface functionalization could considerably alter the environmental behaviors and impact of MWNTs.

  6. Analyzing the Determinants of Job Satisfaction among Jordanian Hospital Employees Using The Warr-Cook-Wall Scale

    Directory of Open Access Journals (Sweden)

    Adriana Anamaria Davidescu

    2016-09-01

    Full Text Available The paper aims to identify the main determinants of job satisfaction in Jordanian hospitals using a sample of 325 employees from six hospitals at the level of the year 2015. In order to do that, we used Warr-Cook-Wall scale to assess job satisfaction based on four dimensions: extrinsic job satisfaction, and intrinsic job satisfaction, working conditions satisfaction, employee relations satisfaction applying the multivariate regression analysis to highlight the predictors of job satisfaction. The empirical results revealed that the main determinants of job satisfaction among Jordanian employees are related to the intrinsic job satisfaction and employee relations satisfaction and the wage have a relatively small impact on this. The findings revealed that the financial incentives have their significance but they are not fundamental, the non-financial incentives being really important in enhancing motivation among health employees. So, in order to improve the overall degree of retention, the managers need to reinforce the importance of non-financial factors like the freedom to choose the working methods, the recognition for a good work, the responsibility, the chance for promotion, the opportunity to use the abilities, the attention paid to the suggestions and the level of variety in the job.

  7. Impact and mitigation of disruptions with the ITER-like wall in JET

    Science.gov (United States)

    Lehnen, M.; Arnoux, G.; Brezinsek, S.; Flanagan, J.; Gerasimov, S. N.; Hartmann, N.; Hender, T. C.; Huber, A.; Jachmich, S.; Kiptily, V.; Kruezi, U.; Matthews, G. F.; Morris, J.; Plyusnin, V. V.; Reux, C.; Riccardo, V.; Sieglin, B.; de Vries, P. C.; EFDA Contributors, JET

    2013-09-01

    Disruptions are a critical issue for ITER because of the high thermal and magnetic energies that are released on short timescales, which results in extreme forces and heat loads. The choice of material of the plasma-facing components (PFCs) can have significant impact on the loads that arise during a disruption. With the ITER-like wall (ILW) in JET made of beryllium in the main chamber and tungsten in the divertor, the main finding is a low fraction of radiation. This has dropped significantly with the ILW from 50-100% of the total energy being dissipated during disruptions in CFC wall plasmas, to less than 50% on average and down to just 10% for vertical displacement events (VDEs). All other changes in disruption properties and loads are consequences of this low radiation: long current quenches (CQs), high vessel forces caused by halo currents and toroidal current asymmetries as well as severe heat loads. Temperatures close to the melting limit have been locally observed on upper first wall structures during deliberate VDE and even at plasma currents as low as 1.5 MA and thermal energy of about 1.5 MJ only. A high radiation fraction can be regained by massive injection of a mixture of 10% Ar with 90% D2. This accelerates the CQ thus reducing the halo current and sideways impulse. The temperature of PFCs stays below 400 °C. MGI is now a mandatory tool to mitigate disruptions in closed-loop operation for currents at and above 2.5 MA in JET.

  8. The measured energy impact of air leakage on frame wall systems

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, S.

    1991-06-01

    Infiltration is customarily assumed to increase the heating and cooling load of a building by an amount equal to the mass flow rate of the infiltration times the enthalpy difference between the inside and outside air -- with the latent portion of the enthalpy difference sometimes neglected. An experimental and analytical investigation has been conducted on the actual energy impact of air leakage on frame wall systems. Calorimetric measurements conducted on a small test cell and on a well characterized stud-cavity wall specimen with measured amounts of air leakage introduced under a variety of controlled conditions and configurations show convincingly that infiltration can lead to a much smaller change in the energy load than is customarily calculated. The data also suggest that the phenomenon occurs in full-sized houses as well. Infiltration Heat Exchange Effectiveness (IHEE),{var epsilon}, is introduced as a measure of the effectiveness of a building in recovering'' heat otherwise lost (or gained) because of infiltration. Measurements show that {var epsilon} increases as: (a) flow rate decreases; (b) flow path length increases; and, (c) hole/crack size decreases.

  9. The measured energy impact of air leakage on frame wall systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, S.

    1991-06-01

    Infiltration is customarily assumed to increase the heating and cooling load of a building by an amount equal to the mass flow rate of the infiltration times the enthalpy difference between the inside and outside air -- with the latent portion of the enthalpy difference sometimes neglected. An experimental and analytical investigation has been conducted on the actual energy impact of air leakage on frame wall systems. Calorimetric measurements conducted on a small test cell and on a well characterized stud-cavity wall specimen with measured amounts of air leakage introduced under a variety of controlled conditions and configurations show convincingly that infiltration can lead to a much smaller change in the energy load than is customarily calculated. The data also suggest that the phenomenon occurs in full-sized houses as well. Infiltration Heat Exchange Effectiveness (IHEE),{var_epsilon}, is introduced as a measure of the effectiveness of a building in ``recovering`` heat otherwise lost (or gained) because of infiltration. Measurements show that {var_epsilon} increases as: (a) flow rate decreases; (b) flow path length increases; and, (c) hole/crack size decreases.

  10. Impact of blood rheology on wall shear stress in a model of the middle cerebral artery

    Science.gov (United States)

    Bernabeu, Miguel O.; Nash, Rupert W.; Groen, Derek; Carver, Hywel B.; Hetherington, James; Krüger, Timm; Coveney, Peter V.

    2013-01-01

    Perturbations to the homeostatic distribution of mechanical forces exerted by blood on the endothelial layer have been correlated with vascular pathologies, including intracranial aneurysms and atherosclerosis. Recent computational work suggests that, in order to correctly characterize such forces, the shear-thinning properties of blood must be taken into account. To the best of our knowledge, these findings have never been compared against experimentally observed pathological thresholds. In this work, we apply the three-band diagram (TBD) analysis due to Gizzi et al. (Gizzi et al. 2011 Three-band decomposition analysis of wall shear stress in pulsatile flows. Phys. Rev. E 83, 031902. (doi:10.1103/PhysRevE.83.031902)) to assess the impact of the choice of blood rheology model on a computational model of the right middle cerebral artery. Our results show that, in the model under study, the differences between the wall shear stress predicted by a Newtonian model and the well-known Carreau–Yasuda generalized Newtonian model are only significant if the vascular pathology under study is associated with a pathological threshold in the range 0.94–1.56 Pa, where the results of the TBD analysis of the rheology models considered differs. Otherwise, we observe no significant differences. PMID:24427534

  11. The measured energy impact of air leakage on frame wall systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, S.

    1991-06-01

    Infiltration is customarily assumed to increase the heating and cooling load of a building by an amount equal to the mass flow rate of the infiltration times the enthalpy difference between the inside and outside air -- with the latent portion of the enthalpy difference sometimes neglected. An experimental and analytical investigation has been conducted on the actual energy impact of air leakage on frame wall systems. Calorimetric measurements conducted on a small test cell and on a well characterized stud-cavity wall specimen with measured amounts of air leakage introduced under a variety of controlled conditions and configurations show convincingly that infiltration can lead to a much smaller change in the energy load than is customarily calculated. The data also suggest that the phenomenon occurs in full-sized houses as well. Infiltration Heat Exchange Effectiveness (IHEE),{var_epsilon}, is introduced as a measure of the effectiveness of a building in ``recovering`` heat otherwise lost (or gained) because of infiltration. Measurements show that {var_epsilon} increases as: (a) flow rate decreases; (b) flow path length increases; and, (c) hole/crack size decreases.

  12. The measured energy impact of air leakage on frame wall systems

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, S.

    1991-06-01

    Infiltration is customarily assumed to increase the heating and cooling load of a building by an amount equal to the mass flow rate of the infiltration times the enthalpy difference between the inside and outside air -- with the latent portion of the enthalpy difference sometimes neglected. An experimental and analytical investigation has been conducted on the actual energy impact of air leakage on frame wall systems. Calorimetric measurements conducted on a small test cell and on a well characterized stud-cavity wall specimen with measured amounts of air leakage introduced under a variety of controlled conditions and configurations show convincingly that infiltration can lead to a much smaller change in the energy load than is customarily calculated. The data also suggest that the phenomenon occurs in full-sized houses as well. Infiltration Heat Exchange Effectiveness (IHEE),{var epsilon}, is introduced as a measure of the effectiveness of a building in recovering'' heat otherwise lost (or gained) because of infiltration. Measurements show that {var epsilon} increases as: (a) flow rate decreases; (b) flow path length increases; and, (c) hole/crack size decreases.

  13. Robust determination of asymmetric side wall angles by means of coherent scanning Fourier scatterometry

    Science.gov (United States)

    Gödecke, M. L.; Peterhänsel, S.; Frenner, K.; Osten, W.

    2016-04-01

    Optical metrology of grating parameters with small scattering volumes, such as side wall angles (SWAs), is an indispensable prerequisite for accurate process control in modern semiconductor lithography. However, current scatterometric technologies suffer from low sensitivity towards SWA and hence, large measurement uncertainties. In order to overcome this deficit, we propose an interferometric sensor design which enables the precise determination of asymmetric SWAs with values that deviate by less than 1° from the ideal 90°. Our measurement technique is based on coherent scanning Fourier scatterometry, extended by a reference arm in Mach-Zehnder/Linnik configuration, a spatially-structured aperture stop in the object arm, and a self-referencing shearing element in front of the detector. We demonstrate the validity and advantages of our approach by presenting rigorous simulations of an exemplary silicon line grating with a grating period of 800 nm. Each grating line consists of a fine sub-grating with 40 nm pitch and 20 nm critical dimension. A variation of the major grating parameters height and critical dimension highlights the robustness of the method. Although our simulation study focuses on the determination of asymmetric SWAs, it should be noted that the presented technique features high sensitivity towards all kinds of structural asymmetries, such as floor tilt or asymmetric bottom roundings.

  14. Determination of Groundwater Velocity and Dispersion Parameters by Borehole Wall Multielectrode Geoelectrics

    Science.gov (United States)

    Kessels, W.; Wuttke, M. W.

    2007-05-01

    A single well technique to determine groundwater flow values and transport parameters is presented. Multielectrode arrays are placed at the filtered casing depth by an inflatable packer or are installed on the borehole wall behind the casing.Tracer water with a higher or lower specific electrical conductivity (salinity) which is injected between the electrodes. This tracer plume then moves into the natural groundwater flow field. The observation of this movement by geoelectric logging enables the determination of the groundwater velocity and salinity. The transport parameters "effective porosity" and "dispersion length" can also be derived. The geoelectric logging uses n borehole electrodes and two grounding electrodes. Thus, either n independent two point measurements or n*(n-1)/2 pole-to-pole measurements can be conducted to obtain a full set of geoelectric measurements. This set is used to derive all electrode combinations by applying the law of superposition and reciprocity. The tracer distribution around the borehole during and after injection depends on the hydraulic and transport parameters of the aquifer and the filter sand. The transport parameter "porosity" plus the total injected tracer volume determines the tracer distribution around the borehole. The transport parameter "dispersivity" determines the abruptness of the tracer front. The method was tested by undertaking measurements in a lab aquifer filled with sand. The results are discussed and the limitations of the method are shown. Multielectrode installations behind casing were tested in situ in the two scientific boreholes CAT-LUD-1 and CAT- LUD-1A drilled in the northern part of Germany. A multielectrode packer system was designed, built and tested in these boreholes. The results are compared with colloid observations in the borehole and hydraulic triangulation in surrounded observation wells. Here, the interpretation of these in situ measurements is mainly restricted to two point geoelectric

  15. Determination of effective heat transport coefficients for wall-cooled packed beds

    NARCIS (Netherlands)

    Borkink, J.G.H.; Borkink, J.G.H.; Westerterp, K.R.

    1992-01-01

    The influence is studied of several assumptions, often made in literature, on the values for the effective radial heat conductivity, wall heat transfer coefficient and overall heat transfer coefficient, as obtained from experiments in wall-cooled packed beds without a chemical reaction. Especially t

  16. DENSIFICATION OF WOOD VENEERS COMBINED WITH OIL-HEAT TREATMENT. PART III: CELL WALL MECHANICAL PROPERTIES DETERMINED BY NANOINDENTATION

    Directory of Open Access Journals (Sweden)

    Cecillia Bustos Avila,

    2012-02-01

    Full Text Available Compression under the effect of heat and steam, also called thermo-hygromechanical (THM densification, can increase wood density and therefore improve its strength, stiffness, and hardness. Oil-heat treatment (OHT is also known to reduce wood’s hygroscopicity and improve dimensional stability. A combination of both treatments can therefore produce wood with improved mechanical properties and dimensional stability. The objective of this project was to determine cell wall mechanical properties of THM-densified and OHT wood. Trembling aspen veneers were densified by a THM process and subsequently treated in canola oil at 200 and 220°C. Nanoindentations were performed in earlywood cell walls. The results show that cell wall longitudinal modulus of elasticity increased significantly from 13.5 GPa for the control to a maximum of 18.2 GPa for THM densified wood with or without OHT. Cell wall hardness increased from 0.27 GPa to a maximum of 0.43 GPa. Both THM densification and OHT significantly increased cell wall hardness. Therefore, the increase in mechanical properties of THM-densified and OHT wood can be due to an increase in wood density resulting from a reduction in porosity but also to an increase in the mechanical properties of the cell wall.

  17. Parametric Study of Exhaust Pattern in Cold Spray Using CFD and Particle-Wall Impact Analysis

    Directory of Open Access Journals (Sweden)

    M. Karimi

    2014-01-01

    Full Text Available A numerical simulation of a cold gas dynamic spray process using a computational fluid dynamic (CFD technique is presented. Distribution of particulate matter in the immediate surroundings of spray application site is of interest. The flow field inside an oval shaped supersonic nozzle and the surroundings of the nozzle is simulated. Particle trajectories along their flight in the nozzle as well as before and after impact with the target plane are calculated. Fluent is used for the purpose of flow field simulation. A discrete-phase Lagrangian particle trajectory model is used for particle trajectory calculation. A model uses the principles of motion and impact dynamics to predict particle behavior upon impacting the substrate. The locations and concentrations of particle exhaust patterns around the impact location are determined and presented graphically. The dependence of these patterns to variations in the jet-target tilting angle, standoff distance, upstream temperature and particle material is investigated.

  18. Modular and scalable load-wall sled buck for pure-lateral and oblique side impact tests.

    Science.gov (United States)

    Yoganandan, Narayan; Humm, John R; Pintar, Frank A

    2012-05-11

    A considerable majority of side impact sled tests using different types of human surrogates has used a load-wall design not specific to subject anthropometry. The use of one load-wall configuration cannot accurately isolate and evaluate regional responses for the same load-wall geometry. As the anatomy and biomechanical responses of the human torso depends on the region, and anthropomorphic test devices continue to advance and accommodate regional differences, it is important to obtain specific data from sled tests. To achieve this goal, the present study designed a scalable modular load-wall consisting of the shoulder, thorax, abdomen, and superior and inferior pelvis, and lower limb plates. The first five plates were connected to a vertical fixture and the limb plate was connected to another fixture. The width, height, and thickness, and the gap between plates were modular. Independent adjustments in the coronal and sagittal planes allowed region-specific positioning depending on surrogate anthropometry, example pelvis width and seated height. Two tri-axial load cells were fixed on the contralateral face of each plate of the load-wall to record impact force-time histories. The load-wall and vertical fixture design can be used to conduct side impact tests with varying vectors, pure-lateral to anterior and posterior oblique, by appropriately orienting the load-wall with respect to the surrogate. The feasibility of the design to extract region-specific biomechanical data was demonstrated by conducting pure-lateral and anterior oblique sled tests using two different surrogates at a velocity of 6.7m/s. Uses of this design are discussed for different applications.

  19. Low-cost, high-power mechanical impact transducers for sonar and acoustic through-wall surveillance applications

    CERN Document Server

    Felber, Franklin

    2014-01-01

    A new concept is presented for mechanical acoustic transmitters and matched resonant receivers. The lightweight, compact, and low-cost transmitters produce high-power acoustic pulses at one or more discrete frequencies with very little input power. The transducer systems are well suited for coupling acoustic pulse energy into dense media, such as walls and water. Applications of the impact transducers are discussed, including detection and tracking of humans through walls and long-duration underwater surveillance by a low-cost network of autonomous, self-recharging, battery-operated sonobuoys. A conceptual design of a sonobuoy surveillance network for harbors and littoral waters is presented. An impact-transmitter and matched-receiver system that detected human motion through thick walls with only rudimentary signal processing is described, and results are presented. Signal processing methods for increasing the signal-to-noise ratio by several tens of dB are discussed.

  20. Direct and Indirect Impacts of Vegetation on Building Comfort: A Comparative Study of Lawns, Green Walls and Green Roofs

    Directory of Open Access Journals (Sweden)

    Laurent Malys

    2016-01-01

    Full Text Available Following development and validation of the SOLENE-microclimat tool, the underlying model was used to compare the impacts of various “greening strategies” on buildings’ summer energy consumption and indoor comfort. This study distinguishes between direct and indirect impacts by successively implementing the test strategies on both the studied building and surrounding ones; it also considers insulated vs. non-insulated buildings. Findings indicate that green walls have a direct effect on indoor comfort throughout the entire building, whereas the effect of green roofs is apparently primarily confined to the upper floor. Moreover, the indirect effect of a green wall is greater, mainly due to the drop in infrared emissions resulting from a lower surface temperature. It has also been proven that the indirect effects of green walls and surrounding lawns can help reduce the loads acting on a non-insulated building.

  1. Determinants of Murein Hydrolase Targeting to Cross-wall of Staphylococcus aureus Peptidoglycan*

    Science.gov (United States)

    Frankel, Matthew B.; Schneewind, Olaf

    2012-01-01

    Cells of eukaryotic or prokaryotic origin express proteins with LysM domains that associate with the cell wall envelope of bacteria. The molecular properties that enable LysM domains to interact with microbial cell walls are not yet established. Staphylococcus aureus, a spherical microbe, secretes two murein hydrolases with LysM domains, Sle1 and LytN. We show here that the LysM domains of Sle1 and LytN direct murein hydrolases to the staphylococcal envelope in the vicinity of the cross-wall, the mid-cell compartment for peptidoglycan synthesis. LysM domains associate with the repeating disaccharide β-N-acetylmuramic acid, (1→4)-β-N-acetylglucosamine of staphylococcal peptidoglycan. Modification of N-acetylmuramic acid with wall teichoic acid, a ribitol-phosphate polymer tethered to murein linkage units, prevents the LysM domain from binding to peptidoglycan. The localization of LytN and Sle1 to the cross-wall is abolished in staphylococcal tagO mutants, which are defective for wall teichoic acid synthesis. We propose a model whereby the LysM domain ensures septal localization of LytN and Sle1 followed by processive cleavage of peptidoglycan, thereby exposing new LysM binding sites in the cross-wall and separating bacterial cells. PMID:22303016

  2. Determinants of murein hydrolase targeting to cross-wall of Staphylococcus aureus peptidoglycan.

    Science.gov (United States)

    Frankel, Matthew B; Schneewind, Olaf

    2012-03-23

    Cells of eukaryotic or prokaryotic origin express proteins with LysM domains that associate with the cell wall envelope of bacteria. The molecular properties that enable LysM domains to interact with microbial cell walls are not yet established. Staphylococcus aureus, a spherical microbe, secretes two murein hydrolases with LysM domains, Sle1 and LytN. We show here that the LysM domains of Sle1 and LytN direct murein hydrolases to the staphylococcal envelope in the vicinity of the cross-wall, the mid-cell compartment for peptidoglycan synthesis. LysM domains associate with the repeating disaccharide β-N-acetylmuramic acid, (1→4)-β-N-acetylglucosamine of staphylococcal peptidoglycan. Modification of N-acetylmuramic acid with wall teichoic acid, a ribitol-phosphate polymer tethered to murein linkage units, prevents the LysM domain from binding to peptidoglycan. The localization of LytN and Sle1 to the cross-wall is abolished in staphylococcal tagO mutants, which are defective for wall teichoic acid synthesis. We propose a model whereby the LysM domain ensures septal localization of LytN and Sle1 followed by processive cleavage of peptidoglycan, thereby exposing new LysM binding sites in the cross-wall and separating bacterial cells.

  3. Determining scientific impact using a collaboration index.

    Science.gov (United States)

    Stallings, Jonathan; Vance, Eric; Yang, Jiansheng; Vannier, Michael W; Liang, Jimin; Pang, Liaojun; Dai, Liang; Ye, Ivan; Wang, Ge

    2013-06-11

    Researchers collaborate on scientific projects that are often measured by both the quantity and the quality of the resultant peer-reviewed publications. However, not all collaborators contribute to these publications equally, making metrics such as the total number of publications and the H-index insufficient measurements of individual scientific impact. To remedy this, we use an axiomatic approach to assign relative credits to the coauthors of a given paper, referred to as the A-index for its axiomatic foundation. In this paper, we use the A-index to compute the weighted sums of peer-reviewed publications and journal impact factors, denoted as the C- and P-indexes for collaboration and productivity, respectively. We perform an in-depth analysis of bibliometric data for 186 biomedical engineering faculty members and from extensive simulation. It is found that these axiomatically weighted indexes better capture a researcher's scientific caliber than do the total number of publications and the H-index, allowing for fairer and sharper evaluation of researchers with diverse collaborative behaviors.

  4. Determining scientific impact using a collaboration index

    Science.gov (United States)

    Stallings, Jonathan; Vance, Eric; Yang, Jiansheng; Vannier, Michael W.; Liang, Jimin; Pang, Liaojun; Dai, Liang; Ye, Ivan; Wang, Ge

    2013-01-01

    Researchers collaborate on scientific projects that are often measured by both the quantity and the quality of the resultant peer-reviewed publications. However, not all collaborators contribute to these publications equally, making metrics such as the total number of publications and the H-index insufficient measurements of individual scientific impact. To remedy this, we use an axiomatic approach to assign relative credits to the coauthors of a given paper, referred to as the A-index for its axiomatic foundation. In this paper, we use the A-index to compute the weighted sums of peer-reviewed publications and journal impact factors, denoted as the C- and P-indexes for collaboration and productivity, respectively. We perform an in-depth analysis of bibliometric data for 186 biomedical engineering faculty members and from extensive simulation. It is found that these axiomatically weighted indexes better capture a researcher’s scientific caliber than do the total number of publications and the H-index, allowing for fairer and sharper evaluation of researchers with diverse collaborative behaviors. PMID:23720314

  5. An evaluation of the impact of multi-walled carbon nanotubes on soil microbial community structure and functional diversity

    Science.gov (United States)

    Increasing application of carbon nanotubes (CNTs) triggers the need for an assessment of their effects on organisms in the environment. Soil microbial communities play a significant role in soil organic matter dynamics and nutrient cycling. This study evaluated the impacts of multi-walled carbon nan...

  6. Electrochemical Determination of Pentachlorophenol in Water on a Multi-Wall Carbon Nanotubes-Epoxy Composite Electrode

    NARCIS (Netherlands)

    Remes, A.; Pop, A.; Manea, F.; Baciu, A.; Picken, S.J.; Schoonman, J.

    2012-01-01

    The aim of this study was the preparation, characterization, and application of a multi-wall carbon nanotubes-epoxy composite electrode (MWCNT-EP) with 25%, wt. MWCNTs loading for the voltammetric/amperometric determination of pentachlorophenol (PCP) in aqueous solutions. The structural and

  7. Electrochemical Determination of Pentachlorophenol in Water on a Multi-Wall Carbon Nanotubes-Epoxy Composite Electrode

    NARCIS (Netherlands)

    Remes, A.; Pop, A.; Manea, F.; Baciu, A.; Picken, S.J.; Schoonman, J.

    2012-01-01

    The aim of this study was the preparation, characterization, and application of a multi-wall carbon nanotubes-epoxy composite electrode (MWCNT-EP) with 25%, wt. MWCNTs loading for the voltammetric/amperometric determination of pentachlorophenol (PCP) in aqueous solutions. The structural and morpholo

  8. Impact of single-walled carbon nanotubes on the embryo: a brief review

    Directory of Open Access Journals (Sweden)

    Al Moustafa AE

    2016-01-01

    Full Text Available Ala-Eddin Al Moustafa,1–4 Etienne Mfoumou,5 Dacian E Roman,3 Vahe Nerguizian,6 Anas Alazzam,7 Ion Stiharu,3 Amber Yasmeen8 1College of Medicine & Biomedical Research Centre, Qatar University, Doha, Qatar; 2Oncology Department, McGill University, 3Mechanical and Industrial Engineering Department, Concordia University, Montreal, QC, Canada; 4Syrian Research Cancer Centre of the Syrian Society against Cancer, Aleppo, Syria; 5Nova Scotia Community College, Dartmouth, NS, 6École de Technologie Supérieure, Montreal, QC, Canada; 7Department of Mechanical Engineering, Khalifa University, Abu Dhabi, UAE; 8Segal Cancer Centre, Lady Davis Institute for Medical Research of the Sir Mortimer B. Davis-Jewish General Hospital, Montreal, QC, Canada Abstract: Carbon nanotubes (CNTs are considered one of the most interesting materials in the 21st century due to their unique physiochemical characteristics and applicability to various industrial products and medical applications. However, in the last few years, questions have been raised regarding the potential toxicity of CNTs to humans and the environment; it is believed that the physiochemical characteristics of these materials are key determinants of CNT interaction with living cells and hence determine their toxicity in humans and other organisms as well as their embryos. Thus, several recent studies, including ours, pointed out that CNTs have cytotoxic effects on human and animal cells, which occur via the alteration of key regulator genes of cell proliferation, apoptosis, survival, cell–cell adhesion, and angiogenesis. Meanwhile, few investigations revealed that CNTs could also be harmful to the normal development of the embryo. In this review, we will discuss the toxic role of single-walled CNTs in the embryo, which was recently explored by several groups including ours. Keywords: single-walled carbon nanotubes, embryo, toxicity

  9. Caregiver Burden in Epilepsy: Determinants and Impact

    Directory of Open Access Journals (Sweden)

    Ioannis Karakis

    2014-01-01

    Full Text Available Aim. Caregiver burden (CB in epilepsy constitutes an understudied area. Here we attempt to identify the magnitude of this burden, the factors associated with it, and its impact to caregiver quality of life (QOL. Methods. 48 persons with epilepsy (PWE underwent video-EEG monitoring and their caregivers completed questionnaires providing demographic, disease-related, psychiatric, cognitive, sleep, QOL, and burden information. Results. On regression analysis, higher number of antiepileptic drugs, poorer patient neuropsychological performance, lower patient QOL score, and lower caregiver education level were associated with higher CB. Time allocated to patient care approximated but did not attain statistical significance. A moderate inverse correlation between CB and caregiver QOL physical component summary score and a stronger inverse correlation between CB and caregiver QOL mental component summary score were seen. Conclusion. In a selected cohort of PWE undergoing video-EEG monitoring, we identified modest degree of CB, comparable to that reported in the literature for other chronic neurological conditions. It is associated with specific patient and caregiver characteristics and has a negative effect on caregiver QOL.

  10. An Analytical Method for Determining the Convection Heat Transfer Coefficient Between Flowing Fluid and Rock Fracture Walls

    Science.gov (United States)

    Bai, Bing; He, Yuanyuan; Hu, Shaobin; Li, Xiaochun

    2017-07-01

    The convective heat transfer coefficient (HTC) is a useful indicator that characterizes the convective heat transfer properties between flowing fluid and hot dry rock. An analytical method is developed to explore a more realistic formula for the HTC. First, a heat transfer model is described that can be used to determine the general expression of the HTC. As one of the novel elements, the new model can consider an arbitrary function of temperature distribution on the fracture wall along the direction of the rock radius. The resulting Dirichlet problem of the Laplace equation on a semi-disk is successfully solved with the Green's function method. Four specific formulas for the HTC are derived and compared by assuming the temperature distributions along the radius of the fracture wall to be zeroth-, first-, second-, and third-order polynomials. Comparative verification of the four specific formulas based on the test data shows that the formula A corresponding to the zeroth-order polynomial always predicts stable HTC values. At low flow rates, the four formulas predict similar values of HTC, but at higher flow rates, formulas B and D, respectively, corresponding to the first- and third-order polynomials, predict either too large or too small values of the HTC, while formula C, corresponding to the second-order polynomial, predicts relatively acceptable HTC values. However, we cannot tell which one is the more rational formula between formulas A and C due to the limited information measured. One of the clear advantages of formula C is that it can avoid the drawbacks of the discontinuity of temperature and the singular integral of HTC at the points (± R, 0). Further experimental work to measure the actual temperature distribution of water in the fracture will be of great value. It is also found that the absorbed heat of the fluid, Q, has a significant impact on the prediction results of the HTC. The temperatures at the inlet and the outlet used for Q should be

  11. Can experts in acetabular fracture care determine hip stability after posterior wall fractures using plain radiographs and computed tomography?

    Science.gov (United States)

    Davis, Adrian T; Moed, Berton R

    2013-10-01

    Hip stability status after a posterior wall acetabular fracture involving 20%-50% of the posterior wall is difficult to determine. However, noted experts have professed that hip stability can be accurately determined by careful review of high-quality anteroposterior and oblique plain radiographs and a computed tomography scan. The objective of this investigation was to evaluate the interobserver and intraobserver reliabilities and accuracies in determining hip stability status by fellowship-trained orthopedic traumatologists expert in acetabular fracture care using these studies. Reliability and validation study. Level 1 trauma center. Fifteen patients with isolated unilateral posterior wall (OTA 62-A1) acetabular fractures involving 20%-50% of the posterior acetabular wall and known clinical outcome had undergone dynamic stress fluoroscopy under anesthesia to determine hip stability. High-quality anteroposterior and oblique plain radiographs and axial computed tomography images of 15 fractures involving 20%-50% of the posterior acetabular wall were reviewed in random order by 4 fellowship-trained orthopedic traumatologists specializing in acetabular fracture care in 2 separate sessions. The second session occurred after a minimum 1-month washout period. Determination of hip stability status was made for each fracture at the 2 time points based on the images along with any history of dislocation of the hip at the time of injury. These determinations were compared with the findings of examination under anesthesia, which served as the gold standard. Measurement of agreement using the Kappa statistic. Although intraobserver reliability was good (0.65), interobserver reliability was poor (0.12). In addition, percent correct was only 53% (32/60) for the initial reading and only 52% (31/60) for the second. For the initial reading, sensitivity and specificity were 100% (28/28) and 13% (4/32), respectively. For the second reading, the sensitivity and specificity were 57

  12. Numerical simulation of wave impact on a rigid wall using a two--phase compressible SPH method

    CERN Document Server

    Rafiee, Ashkan; Dias, Frédéric

    2013-01-01

    In this paper, an SPH method based on the SPH--ALE formulation is used for modelling two-phase flows with large density ratios and realistic sound speeds. The SPH scheme is further improved to circumvent the tensile instability that may occur in the SPH simulations. The two-phase SPH solver is then used to model a benchmark problem of liquid impact on a rigid wall. The results are compared with an incompressible Level Set solver. Furthermore, a wave impact on a rigid wall with a large entrained air pocket is modelled. The SPH simulation is initialised by the output of a fully non-linear potential flow solver. The pressure distribution, velocity field and impact pressure are then analysed.

  13. Size distributions of sprays produced by violent wave impacts on vertical sea walls.

    Science.gov (United States)

    Watanabe, Y; Ingram, D M

    2016-10-01

    When a steep, breaking wave hits a vertical sea wall in shallow water, a flip-through event may occur, leading to the formation of an up-rushing planar jet. During such an event, a jet of water is ejected at a speed many times larger than the approaching wave's celerity. As the jet rises, the bounded fluid sheet ruptures to form vertical ligaments which subsequently break up to form droplets, creating a polydisperse spray. Experiments in the University of Hokkaido's 24 m flume measured the resulting droplet sizes using image analysis of high-speed video. Consideration of the mechanisms forming spray droplets shows that the number density of droplet sizes is directly proportional to a power p of the droplet radius: where p=-5/2 during the early break-up stage and p=-2 for the fully fragmented state. This was confirmed by experimental observations. Here, we show that the recorded droplet number density follows the lognormal probability distribution with parameters related to the elapsed time since the initial wave impact. This statistical model of polydisperse spray may provide a basis for modelling droplet advection during wave overtopping events, allowing atmospheric processes leading to enhanced fluxes of mass, moisture, heat and momentum in the spray-mediated marine boundary layer over coasts to be described.

  14. Principles of Bacterial Cell-Size Determination Revealed by Cell-Wall Synthesis Perturbations

    Directory of Open Access Journals (Sweden)

    Carolina Tropini

    2014-11-01

    Full Text Available Although bacterial cell morphology is tightly controlled, the principles of size regulation remain elusive. In Escherichia coli, perturbation of cell-wall synthesis often results in similar morphologies, making it difficult to deconvolve the complex genotype-phenotype relationships underlying morphogenesis. Here we modulated cell width through heterologous expression of sequences encoding the essential enzyme PBP2 and through sublethal treatments with drugs that inhibit PBP2 and the MreB cytoskeleton. We quantified the biochemical and biophysical properties of the cell wall across a wide range of cell sizes. We find that, although cell-wall chemical composition is unaltered, MreB dynamics, cell twisting, and cellular mechanics exhibit systematic large-scale changes consistent with altered chirality and a more isotropic cell wall. This multiscale analysis enabled identification of distinct roles for MreB and PBP2, despite having similar morphological effects when depleted. Altogether, our results highlight the robustness of cell-wall synthesis and physical principles dictating cell-size control.

  15. Comparison between methods using copper, lanthanum, and colorimetry for the determination of the cation exchange capacity of plant cell walls.

    Science.gov (United States)

    Wehr, J Bernhard; Blamey, F Pax C; Menzies, Neal W

    2010-04-28

    The determination of the cation exchange capacity (CEC) of plant cell walls is important for many physiological studies. We describe the determination of cell wall CEC by cation binding, using either copper (Cu) or lanthanum (La) ions, and by colorimetry. Both cations are strongly bound by cell walls, permitting fast and reproducible determinations of the CEC of small samples. However, the dye binding methods using two cationic dyes, Methylene Blue and Toluidine Blue, overestimated the CEC several-fold. Column and centrifugation methods are proposed for CEC determination by Cu or La binding; both provide similar results. The column method involves packing plant material (2-10 mg dry mass) in a chromatography column (10 mL) and percolating with 20 bed volumes of 1 mM La or Cu solution, followed by washing with deionized water. The centrifugation method uses a suspension of plant material (1-2 mL) that is centrifuged, and the pellet is mixed three times with 10 pellet volumes of 1 mM La or Cu solution followed by centrifugation and final washing with deionized water. In both methods the amount of La or Cu bound to the material was determined by spectroscopic methods.

  16. 煤巷围岩稳定性分类指标确定研究%Research on Coal Roadway Wall Rock Stability Classification Index Determination

    Institute of Scientific and Technical Information of China (English)

    张小康

    2009-01-01

    Based on the engineering geological conditions and production technology conditions of Huozhou coal electricity group limited liability company, this paper makes a deep analysis on the factors that impact the wall rock stability of the coal seam roadway, in this basis, by using analytic hierarchy process established the AHP model to determine the index of the coal seam roadway wall rock stability classification and extracted nine key index. Has very important significance to the study of the roadway wall rock stability classification.%以霍州煤电集团有限责任公司煤层巷道的具体工程地质条件和生产技术条件为背景,深入分析了影响煤层巷道围岩稳定性的诸多因素,在此基础上,运用层次分析法的基本原理,建立了煤层巷道围岩稳定分类指标确定的AHP分析模型,提取了9个关键指标.对于研究煤层巷道围岩稳定性分类具有十分重要的意义.

  17. Experimental determination of wall correction factors. Pt. 2; NACP and Markus plane-parallel ionization chambers

    Energy Technology Data Exchange (ETDEWEB)

    Wittkaemper, F.W.; Mijnheer, B.J. (Nederlands Kanker Inst. ' Antoni van Leeuwenhoekhuis' , Amsterdam (Netherlands)); Aalbers, A.H.L. (Netherlands Measurements Inst., Bilthoven (Netherlands))

    1992-04-01

    The formalism to derive the absorbed dose to water from ionization chamber measurements in a phantom includes several wall correction factors depending on shape, size and composition of the chamber. Wall correction factors have been measured for a number of NACP and PTW/Markers Chambers. Significant deviations from calculated values occur due to uncertainties in the contribution to the total ionization from the different materials of these inhomogeneous ionization chambers. The discrepancies illustrate the need for the development of a homogeneous plane-parallel chamber. In addition, detailed Monte Carlo calculations, taking the different wall materials into account, are required to quantitatively predict the response of heterogeneous plane-parallel chambers in photon beams. (UK).

  18. Influence of slice thickness on the determination of left ventricular wall thickness and dimension by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Shusaku; Fukui, Sugao; Atsumi, Chisato and others

    1989-02-01

    Wall thickness of the ventricular septum and left ventricle, and left ventricular cavity dimension were determined on magnetic resonance (MR) images with slices 5 mm and 10 mm in thickness. Subjects were 3 healthy volunteers and 7 patients with hypertension (4), hypertrophic cardiomyopathy (one) or valvular heart disease (2). In visualizing the cardiac structures such as left ventricular papillary muscle and right and left ventricles, 5 mm-thick images were better than 10 mm-thick images. Edges of ventricular septum and left ventricular wall were more clearly visualized on 5 mm-thick images than 10 mm-thick images. Two mm-thick MR images obtained from 2 patients yielded the most excellent visualization in end-systole, but failed to reveal cardiac structures in detail in end-diastole. Phantom studies revealed no significant differences in image quality of 10 mm and 5 mm in thickness in the axial view 80 degree to the long axis. In the axial view 45 degree to the long axis, 10 mm-thick images were inferior to 5 mm-thick images in detecting the edge of the septum and the left ventricular wall. These results indicate that the selection of slice thickness is one of the most important determinant factors in the measurement of left ventricular wall thickness and cavity dimension. (Namekawa, K).

  19. Determinants And Impacts Of Poultry Production Technologies On ...

    African Journals Online (AJOL)

    Determinants And Impacts Of Poultry Production Technologies On Productivity Of ... The findings showed that age, rearing experience, Total Variable cost, ... Intensification of farmer education and training (extension) and family planning ...

  20. 24 CFR 58.37 - Environmental impact statement determinations.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Environmental impact statement... Classification § 58.37 Environmental impact statement determinations. (a) An EIS is required when the project is... and Urban Development ENVIRONMENTAL REVIEW PROCEDURES FOR ENTITIES ASSUMING HUD ENVIRONMENTAL...

  1. [Determination of tumor infiltration of the bronchial wall in lung cancer].

    Science.gov (United States)

    Utkin, V V; Ozols, A Ia; Marga, O Ia

    1975-01-01

    In the article, a new method of diagnosing the extent of the tumor spread in the bronchial wall without involvement of the mucosa (a peripbronchial form of the growth) is described. The method consists of two components - angiography of bronchial arteries with subsequent injection of a staining material in the corresponding bronchial artery and bronchoscopy, by means of which staining of the mucous membrane of the bronchial tree is observed. In case of tumor infiltration of the bronchial wall staining was absent completely or partially. A clinical trial of the method indicated its high efficacy.

  2. Numerical modeling of the impact of regenerator housing on the determination of Nusselt numbers

    DEFF Research Database (Denmark)

    Nielsen, Kaspar Kirstein; Nellis, G.F.; Klein, S.A.

    2013-01-01

    to the regenerator fluid is developed. The model is applied to a range of cases and it is shown that at low Reynolds numbers (well below 100) and at Prandtl numbers appropriate to liquids (7 for water) the regenerator housing may influence the experimental determination of Nusselt numbers significantly. The impact......It is suggested that the housing of regenerators may have a significant impact when experimentally determining Nusselt numbers at low Reynolds and large Prandtl numbers. In this paper, a numerical model that takes the regenerator housing into account as a domain that is thermally coupled...... of the housing on the performance during cyclic steady-state regenerator operation is quantified by comparing the regenerator effectiveness for cases where the wall is ignored and with cases where it is included. It is shown that the effectiveness may be decreased by as much as 18% for the cases considered here...

  3. Analyzing the Determinants of Job Satisfaction among Jordanian Hospital Employees Using The Warr-Cook-Wall Scale

    OpenAIRE

    Adriana Anamaria Davidescu; Marji Tania Issa Eid; Cristina Sacală

    2016-01-01

    The paper aims to identify the main determinants of job satisfaction in Jordanian hospitals using a sample of 325 employees from six hospitals at the level of the year 2015. In order to do that, we used Warr-Cook-Wall scale to assess job satisfaction based on four dimensions: extrinsic job satisfaction, and intrinsic job satisfaction, working conditions satisfaction, employee relations satisfaction applying the multivariate regression analysis to highlight the predictors of job satisfaction. ...

  4. Standard guide for mutual inductance bridge applications for wall thickness determinations in boiler tubing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide describes a procedure for obtaining relative wall thickness indications in ferromagnetic and non-ferromagnetic steels using the mutual inductance bridge method. The procedure is intended for use with instruments capable of inducing two substantially identical magnetic fields and noting the change in inductance resulting from differing amounts of steel. It is used to distinguish acceptable wall thickness conditions from those which could place tubular vessels or piping at risk of bursting under high temperature and pressure conditions. 1.2 This guide is intended to satisfy two general needs for users of industrial Mutual Inductance Bridge (MIB) equipment: (1) the need for a tutorial guide addressing the general principles of Mutual Inductance Bridges as they apply to industrial piping; and (2) the need for a consistent set of MIB performance parameter definitions, including how these performance parameters relate to MIB system specifications. Potential users and buyers, as well as experienced M...

  5. Dynamic radionuclide determination of regional left ventricular wall motion using a new digital imaging device

    Science.gov (United States)

    Steele, P.; Kirch, D.

    1975-01-01

    In 47 men with arteriographically defined coronary artery disease comparative studies of left ventricular ejection fraction and segmental wall motion were made with radionuclide data obtained from the image intensifier camera computer system and with contrast cineventriculography. The radionuclide data was digitized and the images corresponding to left ventricular end-diastole and end-systole were identified from the left ventricular time-activity curve. The left ventricular end-diastolic and end-systolic images were subtracted to form a silhouette difference image which described wall motion of the anterior and inferior left ventricular segments. The image intensifier camera allows manipulation of dynamically acquired radionuclide data because of the high count rate and consequently improved resolution of the left ventricular image.

  6. An experimental and theoretical investigation of particle–wall impacts in a T-junction

    KAUST Repository

    Vigolo, D.

    2013-07-01

    Understanding the behaviour of particles entrained in a fluid flow upon changes in flow direction is crucial in problems where particle inertia is important, such as the erosion process in pipe bends. We present results on the impact of particles in a T-shaped channel in the laminar-turbulent transitional regime. The impacting event for a given system is described in terms of the Reynolds number and the particle Stokes number. Experimental results for the impact are compared with the trajectories predicted by theoretical particle-tracing models for a range of configurations to determine the role of the viscous boundary layer in retarding the particles and reducing the rate of collision with the substrate. In particular, a two-dimensional model based on a stagnation-point flow is used together with three-dimensional numerical simulations. We show how the simple two-dimensional model provides a tractable way of understanding the general collision behaviour, while more advanced three-dimensional simulations can be helpful in understanding the details of the flow. © 2013 Cambridge University Press.

  7. Elevated CO2 concentration impacts cell wall polysaccharide composition of green microalgae of the genus Chlorella.

    Science.gov (United States)

    Cheng, Y-S; Labavitch, J M; VanderGheynst, J S

    2015-01-01

    The effect of CO2 concentration on the relative content of starch, lipid and cell wall carbohydrates in microalgal biomass was investigated for the four following Chlorella strains: C. vulgaris (UTEX 259), C. sorokiniana (UTEX 2805), C. minutissima (UTEX 2341) and C. variabilis (NC64A). Each strain had a different response to CO2 concentration. The starch content was higher in UTEX259 and NC64A cultured with 2% CO2 in the air supply than in cells cultured with ca. 0·04% CO2 (ambient air), while starch content was not affected for UTEX 2805 and UTEX 2341. The lipid content was higher in Chlorella minutissima UTEX 2341 cultured in 2% CO2 than in cells cultured in ambient air, but was unchanged for the other three strains. All four Chlorella strains tended to have a higher percentage of uronic acids and lower percentage of neutral sugars in their cell wall polysaccharide complement when grown with 2% CO2 supply. Although the percentage of neutral sugars in the cell walls varied with CO2 concentration, the relative proportions of different neutral sugar constituents remained constant for both CO2 conditions. The results demonstrate the importance of considering the effects of CO2 on the cell wall carbohydrate composition of microalgae. Microalgae have the potential to produce products that will reduce society's reliance on fossil fuels and address challenges related to food and feed production. An overlooked yet industrially relevant component of microalgae are their cell walls. Cell wall composition affects cell flocculation and the recovery of intracellular products. In this study, we show that increasing CO2 level results in greater cell wall polysaccharide and uronic acid content in the cell walls of three strains of microalgae. The results have implications on the management of systems for the capture of CO2 and production of fuels, chemicals and food from microalgae. © 2014 The Society for Applied Microbiology.

  8. Thermal Impact of Fasteners in High-Performance Wood-Framed Walls: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, D.

    2011-01-01

    Buildings are heavy consumers of energy, and residential building design is rapidly addressing topics to maximize energy conservation en route to net-zero energy consumption. Annual energy analysis of a building informs the choice among disparate energy measures, for cost, durability, occupant comfort, and whole-house energy use. Physics-based and empirical models of elements of a building are used in such analyses. High-performance wood-framed walls enable builders to construct homes that use much less than 40% of the energy consumed by similar homes built to minimum code. Modeling for these walls has considered physical features such as framing factor, insulation and framing properties, roughness and convective effects, and air leakage. The thermal effects of fasteners used to construct these walls have not been fully evaluated, even though their thermal conductivity is orders of magnitudes higher than that of other building materials. Drywall screws and siding nails are considered in this finite element thermal conductivity analysis of wall sections that represent wood-framed walls that are often used in high-performance homes. Nails and screws reduce even the best walls' insulating performance by approximately 3% and become increasingly significant as the framing factor increases.

  9. Multi-walled Carbon Nanotubes/Graphite Nanosheets Modified Glassy Carbon Electrode for the Simultaneous Determination of Acetaminophen and Dopamine.

    Science.gov (United States)

    Zhang, Susu; He, Ping; Zhang, Guangli; Lei, Wen; He, Huichao

    2015-01-01

    Graphite nanosheets prepared by thermal expansion and successive sonication were utilized for the construction of a multi-walled carbon nanotubes/graphite nanosheets based amperometric sensing platform to simultaneously determine acetaminophen and dopamine in the presence of ascorbic acid in physiological conditions. The synergistic effect of multi-walled carbon nanotubes and graphite nanosheets catalyzed the electrooxidation of acetaminophen and dopamine, leading to a remarkable potential difference up to 200 mV. The as-prepared modified electrode exhibited linear responses to acetaminophen and dopamine in the concentration ranges of 2.0 × 10(-6) - 2.4 × 10(-4) M (R = 0.999) and 2.0 × 10(-6) - 2.0 × 10(-4) M (R = 0.998), respectively. The detection limits were down to 2.3 × 10(-7) M for acetaminophen and 3.5 × 10(-7) M for dopamine (S/N = 3). Based on the simple preparation and prominent electrochemical properties, the obtained multi-walled carbon nanotubes/graphite nanosheets modified electrode would be a good candidate for the determination of acetaminophen and dopamine without the interference of ascorbic acid.

  10. Impact of wind-driven rain on historic brick wall buildings in a moderately cold and humid climate: Numerical analyses of mould growth risk, indoor climate and energy consumption

    DEFF Research Database (Denmark)

    Masaru, Abuku; Janssen, Hans; Roels, Staf

    2009-01-01

    response, mould growth at interior wall surfaces, indoor climate and energy consumption. First the WDR load oil the facades of a 4 m x 4 m x 10 m tower is determined. Then the hygrothermal behaviour of the brick walls is analysed oil a horizontal slice through the tower. The simulations demonstrate...... that WDR loads can have a significant impact on mould growth especially at the edges of the walls. Finally, for the case analysed, the WDR load Causes a significant increase of indoor relative humidity and energy consumption for heating. (C) 2008 Elsevier B.V. All rights reserved.......This paper gives an onset to whole building hygrothermal modelling in which the interaction between interior and exterior climates via building enclosures is simulated under a moderately cold and humid climate. The focus is particularly on the impact of wind-driven rain (WDR) oil the hygrothermal...

  11. The impact of scaled boundary conditions on wall shear stress computations in atherosclerotic human coronary bifurcations.

    Science.gov (United States)

    Schrauwen, Jelle T C; Schwarz, Janina C V; Wentzel, Jolanda J; van der Steen, Antonius F W; Siebes, Maria; Gijsen, Frank J H

    2016-05-15

    The aim of this study was to determine if reliable patient-specific wall shear stress (WSS) can be computed when diameter-based scaling laws are used to impose the boundary conditions for computational fluid dynamics. This study focused on mildly diseased human coronary bifurcations since they are predilection sites for atherosclerosis. Eight patients scheduled for percutaneous coronary intervention were imaged with angiography. The velocity proximal and distal of a bifurcation was acquired with intravascular Doppler measurements. These measurements were used for inflow and outflow boundary conditions for the first set of WSS computations. For the second set of computations, absolute inflow and outflow ratios were derived from geometry-based scaling laws based on angiography data. Normalized WSS maps per segment were obtained by dividing the absolute WSS by the mean WSS value. Absolute and normalized WSS maps from the measured-approach and the scaled-approach were compared. A reasonable agreement was found between the measured and scaled inflows, with a median difference of 0.08 ml/s [-0.01; 0.20]. The measured and the scaled outflow ratios showed a good agreement: 1.5 percentage points [-19.0; 4.5]. Absolute WSS maps were sensitive to the inflow and outflow variations, and relatively large differences between the two approaches were observed. For normalized WSS maps, the results for the two approaches were equivalent. This study showed that normalized WSS can be obtained from angiography data alone by applying diameter-based scaling laws to define the boundary conditions. Caution should be taken when absolute WSS is assessed from computations using scaled boundary conditions.

  12. Endo-b-1,4-glucanases impact plant cell wall development by influencing cellulose crystallization

    Institute of Scientific and Technical Information of China (English)

    Magdalena Glass; Sarah Barkwill; Faride Unda; Shawn D. Mansfield

    2015-01-01

    Cell walls are vital to the normal growth and development of plants as they protect the protoplast and provide rigidity to the stem. Here, two poplar and Arabidopsis orthologous endoglucanases, which have been proposed to play a role in secondary cell wall development, were examined. The class B endoglucanases, PtGH9B5 and AtGH9B5, are secreted enzymes that have a predicted glycosylphosphatidylinositol anchor, while the class C endo-glucanases, PtGH9C2 and AtGH9C2, are also predicted to be secreted but instead contain a carbohydrate-binding module. The poplar endoglucanases were expressed in Arabidopsis using both a 35S promoter and the Arabidopsis secondary cell wall-specific CesA8 promoter. Additionally, Arabidopsis t-DNA insertion lines and an RNAi construct was created to downregulate AtGH9C2 in Arabidopsis. All of the plant lines were examined for changes in cell morphology and pattern-ing, growth and development, cell wall crystallinity, microfibril angle, and proportion of cell wall carbohydrates. Misregula-tion of PtGH9B5/AtGH9B5 resulted in changes in xylose content, while misregulation of PtGH9C2/AtGH9C2 resulted in changes in crystallinity, which was inversely correlated with changes in plant height and rosette diameter. Together, these results suggest that these endoglucanases affect secondary cell wall development by contributing to the cell wall crystallization process.

  13. Personal Self-Determination and Moderating Variables that Impact Efforts to Promote Self-Determination

    Science.gov (United States)

    Wehmeyer, Michael L.; Abery, Brian H.; Zhang, Dalun; Ward, Karen; Willis, Derrick; Hossain, Waheeda Amin; Balcazar, Fabricio; Ball, Allison; Bacon, Ansley; Calkins, Carl; Heller, Tamar; Goode, Tawara; Dias, Robette; Jesien, George S.; McVeigh, Tom; Nygren, Margaret A.; Palmer, Susan B.; Walker, Hill M.

    2011-01-01

    The purpose of this second article in the special topic issue from the National Training Initiative on Self-Determination is to provide detail with regard to how we understand the self-determination construct and to discuss moderator variables and how such variables impact the design and implementation of interventions to promote…

  14. Simultaneous determination of nitrophenol isomers at the single-wall carbon nanotube compound conducting polymer film modified electrode

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; WANG Zhenhui; ZHOU Shuping

    2005-01-01

    Based on the molecular recognition ability of conductive polymer and the peculiar properties of carbon nanotubes, a novel single wall nanotubes (SWNTs) compound poly(4- aminopyridine) modified electrode (SWNTs/POAPE) is prepared at glass carbon electrode (GCE). The electrochemistry response of nitrophenol isomers is studied at the SWNTs/POAPE. The result indicates that o-, m- and p-nitrophenol are separated entirely at the SWNTs/POAPE interface. The electrode present here can be easily used to determine nitrophenol isomers simultaneously with higher sensitivity.

  15. Hydrodynamics of domain walls in ferroelectrics and multiferroics: Impact on memory devices

    Science.gov (United States)

    Scott, J. F.; Evans, D. M.; Gregg, J. M.; Gruverman, A.

    2016-07-01

    The standard "Kittel Law" for the thickness and shape of ferroelectric, ferroelastic, or ferromagnet domains assumes mechanical equilibrium. The present paper shows that such domains may be highly nonequilibrium, with unusual thicknesses and shapes. In lead germanate and multiferroic lead zirconate titanate iron tantalate domain wall instabilities resemble hydrodynamics (Richtmyer-Meshkov and Helfrich-Hurault, respectively).

  16. Spontaneous Behaviors and Wall-Curvature Lead to Apparent Wall Preference in Planarian.

    Directory of Open Access Journals (Sweden)

    Yoshitaro Akiyama

    Full Text Available The planarian Dugesia japonica tends to stay near the walls of its breeding containers and experimental dishes in the laboratory, a phenomenon called "wall preference". This behavior is thought to be important for environmental adaptation, such as hiding by planarians in nature. However, the mechanisms regulating wall-preference behavior are not well understood, since this behavior occurs in the absence of any particular stimulation. Here we show the mechanisms of wall-preference behavior. Surprisingly, planarian wall-preference behavior was also shown even by the head alone and by headless planarians. These results indicate that planarian "wall-preference" behavior only appears to be a "preference" behavior, and is actually an outcome of spontaneous behaviors, rather than of brain function. We found that in the absence of environmental cues planarians moved basically straight ahead until they reached a wall, and that after reaching a wall, they changed their direction of movement to one tangential to the wall, suggesting that this spontaneous behavior may play a critical role in the wall preference. When we tested another spontaneous behavior, the wigwag movement of the planarian head, using computer simulation with various wigwag angles and wigwag intervals, large wigwag angle and short wigwag interval reduced wall-preference behavior. This indicated that wigwag movement may determine the probability of staying near the wall or leaving the wall. Furthermore, in accord with this simulation, when we tested planarian wall-preference behavior using several assay fields with different curvature of the wall, we found that concavity and sharp curvature of walls negatively impacted wall preference by affecting the permissible angle of the wigwag movement. Together, these results indicate that planarian wall preference may be involuntarily caused by the combination of two spontaneous planarian behaviors: moving straight ahead until reaching a wall and

  17. Determination of optimum insulation thicknesses using economical analyse for exterior walls of buildings with different masses

    Directory of Open Access Journals (Sweden)

    Okan Kon

    2017-07-01

    Full Text Available In this study, five different cities were selected from the five climatic zones according to Turkish standard TS 825, and insulation thicknesses of exterior walls of sample buildings were calculated by using optimization. Vertical perforated bricks with density of 550 kg/m3 and 1000 kg/m3 were chosen within the study content. Glass wool, expanded polystyrene (XPS, extruded polystyrene (EPS were considered as insulation materials. Additionally, natural gas, coal, fuel oil and LPG were utilized as fuel for heating process while electricity was used for cooling.  Life cycle cost (LCC analysis and degree-day method were the approaches for optimum insulation thickness calculations. As a result, in case of usage vertical perforated bricks with density of 550 kg/m3 and 1000 kg/m3 resulted different values in between 0.005-0.007 m (5-7 mm in the optimum insulation thickness calculations under different insulation materials.  Minimum optimum insulation thickness was calculated in case XPS was preferred as insulation material, and the maximum one was calculated in case of using glass wool.

  18. Precise determination of $B_K$ and right quark masses in quenched domain-wall QCD

    CERN Document Server

    Nakamura, Yousuke; Taniguchi, Yusuke; Yoshié, Tomoteru

    2008-01-01

    We calculate non-perturbative renormalization factors at hadronic scale for $\\Delta S=2$ four-quark operators in quenched domain-wall QCD using the Schr\\"{o}dinger functional method. Combining them with the non-perturbative renormalization group running by the Alpha collaboration, our result yields the fully non-perturbative renormalization factor, which converts the lattice bare $B_K$ to the renormalization group invariant (RGI) $\\hat{B}_K$. Applying this to the bare $B_K$ previously obtained by the CP-PACS collaboration at $a^{-1}\\simeq 2, 3, 4$ GeV, we obtain $\\hat{B}_K=0.782(5)(7)$ (equivalent to $B_K^{\\bar{\\rm MS}}({\\rm NDR}, 2 {\\rm GeV}) = 0.565(4)(5)$ by 2-loop running) in the continuum limit, where the first error is statistical and the second is systematic due to the continuum extrapolation. Except the quenching error, the total error we have achieved is less than 2%, which is much smaller than the previous ones. Taking the same procedure, we obtain $m_{u,d}^{\\rm RGI}=5.613(66)$ MeV and $m_s^{\\rm RGI...

  19. Voltammetric determination of theophylline at a Nafion/multi-wall carbon nanotubes composite film-modified glassy carbon electrode

    Indian Academy of Sciences (India)

    Suling Yang; Ran Yang; Gang Li; Jianjun Li; Lingbo Qu

    2010-11-01

    A Nafion/multi-wall carbon nanotubes (MWNTs) composite film-modified electrode was fabricated and applied to the sensitive and convenient determination of theophylline (TP). Multi-wall carbon nanotubes (MWNTs) were easily dispersed homogeneously into 0.1% Nafion methanol solution by sonication. Appropriate amount of Nafion/MWNTs suspension was coated on a glassy carbon electrode. After evaporating methanol, a Nafion/MWNTs composite film-modified electrode was achieved. TP could effectively accumulate at Nafion/MWNTs composite film-modified electrode and cause a sensitive anodic peak at around 1180 mV (vs SCE) in 0.01 mol/L H2SO4 medium (pH 1.8). In contrast with the bare glassy carbon electrode, Nafion film-modified electrode, Nafion/MWNTs film-modified electrode could remarkably increase the anodic peak current and decreased the overpotential of TP oxidation. Under the optimized conditions, the anodic peak current was proportional to TP concentration in the range of 8.0 × 10-8-6.0 × 10-5 mol/L, with a detection limit of 2.0 × 10-8 mol/L. This newly developed method was used to determine TP in drug samples with good percentage of recoveries.

  20. HOSPITAL’S WALL COLOUR IMPACT ON STROKE PATIENTS’ WARD USERS IN SURABAYA

    Directory of Open Access Journals (Sweden)

    Tanuwidjaja GUNAWAN

    2015-12-01

    Full Text Available The Cardiovascular diseases have become the top killer since 1970 worldwide. In 2005, it was recorded the present of 5.7 million stroke survivors. On the other hand, healing stroke and its related complications required much more considerable time. So the patients’ wards quality especially related to wall colour become very important for the patients' recovery. The study was conducted with exploratory methods combining visual methods of research and Luscher colour test. Series of interviews were conducted to gather the users’ perception. So, it was found on that blue wall colour calmed the medical personals, patients, and their family. The most soothing Blue colour variant according to respondents was the Artic Blue (hue 9.8 B, value 7.4 and chroma 5.6.

  1. Impact of Alkali Pretreatment on the Chemical Component Distribution and Ultrastructure of Poplar Cell Walls

    OpenAIRE

    Zhe Ji; Zhe Ling; Xun Zhang; Gui-Hua Yang; Feng Xu

    2014-01-01

    Alkali pretreatment is one of the leading pretreatment technologies for biofuel applications. The histochemical and structural characteristics of poplar cell walls were investigated before and after sodium hydroxide pretreatment (121 oC, 2%) to understand the alterations in biomass cellular structure, which were correlated with saccharification yield. Results showed that alkali pretreatment preferentially removed lignin from the S2 of fibers, which was similar to the behaviors of coniferyl al...

  2. Pinoresinol reductase 1 impacts lignin distribution during secondary cell wall biosynthesis in Arabidopsis.

    Science.gov (United States)

    Zhao, Qiao; Zeng, Yining; Yin, Yanbin; Pu, Yunqiao; Jackson, Lisa A; Engle, Nancy L; Martin, Madhavi Z; Tschaplinski, Timothy J; Ding, Shi-You; Ragauskas, Arthur J; Dixon, Richard A

    2015-04-01

    Pinoresinol reductase (PrR) catalyzes the conversion of the lignan (-)-pinoresinol to (-)-lariciresinol in Arabidopsis thaliana, where it is encoded by two genes, PrR1 and PrR2, that appear to act redundantly. PrR1 is highly expressed in lignified inflorescence stem tissue, whereas PrR2 expression is barely detectable in stems. Co-expression analysis has indicated that PrR1 is co-expressed with many characterized genes involved in secondary cell wall biosynthesis, whereas PrR2 expression clusters with a different set of genes. The promoter of the PrR1 gene is regulated by the secondary cell wall related transcription factors SND1 and MYB46. The loss-of-function mutant of PrR1 shows, in addition to elevated levels of pinoresinol, significantly decreased lignin content and a slightly altered lignin structure with lower abundance of cinnamyl alcohol end groups. Stimulated Raman scattering (SRS) microscopy analysis indicated that the lignin content of the prr1-1 loss-of-function mutant is similar to that of wild-type plants in xylem cells, which exhibit a normal phenotype, but is reduced in the fiber cells. Together, these data suggest an association of the lignan biosynthetic enzyme encoded by PrR1 with secondary cell wall biosynthesis in fiber cells.

  3. Electrochemical determination of cadmium and lead on pristine single-walled carbon nanotube electrodes.

    Science.gov (United States)

    Bui, Minh-Phuong Ngoc; Li, Cheng Ai; Han, Kwi Nam; Pham, Xuan-Hung; Seong, Gi Hun

    2012-01-01

    A flexible, transparent, single-walled carbon nanotube (SWCNT) film electrode was prepared by vacuum filtering methods, followed by photolithographic patterning of a photoresist polymer on the SWCNT surface. The morphology of the SWCNT film electrode surface was characterized using a field-emission scanning electron microscope coupled to an energy-dispersive X-ray spectrophotometer. The electrodes were successfully used as a mercury-free electrochemical sensor for individual and simultaneous detection of cadmium (Cd(2+)) and lead (Pb(2+)) in 0.02 M HCl by square-wave stripping voltammetry. Some important operational parameters, including deposition time, deposition potential, square-wave amplitude, and square wave-frequency were optimized for the detection of Cd(2+) and Pb(2+). The newly developed sensor showed good linear behavior in the examined concentration. For individual Cd(2+) and Pb(2+) ion detection, the linear range was found from 0.033 to 0.228 ppm with detection limits of 0.7 ppb (R(2) = 0.985) for Cd(2+) and 0.8 ppb (R(2) = 0.999) for Pb(2+). For simultaneous detection, the linear range was found from 0.033 to 0.280 ppm with a limit of detection of 2.2 ppb (R(2) = 0.976) and 0.6 ppb (R(2) = 0.996) for Cd(2+) and Pb(2+), respectively. SWCNT film electrodes offered favorable reproducibility of ± 5.4% and 4.3% for Cd(2+) and Pb(2+), respectively. The experiments demonstrated the applicability of carbon nanotubes, specifically in the preparation of SWCNT films. The results suggest that the proposed flexible SWCNT film electrodes can be applied as simple, efficient, cost-effective, and/or disposable electrodes for simultaneous detection of heavy metal ions.

  4. Determining through numerical modeling the effective thermal resistance of a foundation wall system with low emissivity material and furred-airspace

    Energy Technology Data Exchange (ETDEWEB)

    Sabed, Hamed H.; Swinton, M. [National Research Council Canada, Institute for Reserch in Construction, Ottawa, (Canada)

    2010-07-01

    This paper determined the effective thermal resistance of a foundation wall system with low emissivity material and furred airspace through numerical modelling. The model hygIRC-C , a 2D and 3D hygrothermal model, was used to conduct numerical simulations to determine the effective thermal resistance of a foundation wall system having a furred airspace assembly and incorporating low emissivity foil materials. This model accounts for surface-to-surface radiation between the surfaces of the furring, gypsum board and foil. A parametric was conducted to determine the effective thermal resistance of the foundation wall system as a function of foil emissivity. The results showed that, with the furring installed horizontally, a low foil emissivity of 0.05 can increase the wall R-value by as much as approximately 10%. A benchmarking of the present model against experimental data is currently being performed.

  5. MRI of small bowel Crohn's disease: determining the reproducibility of bowel wall gadolinium enhancement measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sharman, A.; Zealley, I.A. [Ninewells Hospital, Dundee (United Kingdom); Greenhalgh, R.; Taylor, S.A. [University College Hospital, Department of Imaging, London (United Kingdom); Bassett, P. [Stats Consultancy, Ruislip (United Kingdom)

    2009-08-15

    This study aims to determine inter- and intra-observer variation in MRI measurements of relative bowel wall signal intensity (SI) in Crohn's disease. Twenty-one small bowel MRI examinations (11 male, mean age 40), including T1-weighted acquisitions acquired 30 to 120s post-gadolinium, were analysed. Maximal bowel wall SI (most avid, conspicuous contrast enhancement) in designated diseased segments was measured by two radiologists and two trainees using self-positioned ''free'' regions of interest (ROIs) followed by ''fixed'' ROIs chosen by one radiologist, and this procedure was repeated 1 month later. Relative enhancement (post-contrast SI minus pre-contrast SI/pre-contrast SI) was calculated. Data were analysed using Bland-Altman limits of agreement and intra-class correlation. Inter-observer agreement for relative enhancement was poor (spanning over 120%) using a free ROI - 95% limits of agreement -0.69, 0.70 and -0.47, 0.74 for radiologists and trainees, respectively, only marginally improved by use of a fixed ROI -0.60, 0.67 and -0.59, 0.49. Intra-class correlation ranged from 0.46 to 0.72. Intra-observer agreement was slightly better and optimised using a fixed ROI - 95% limits of agreement -0.52, 0.50 and -0.34, 0.28 for radiologists and trainees, respectively. Intra-class correlation ranged from 0.49 to 0.86. Relative bowel wall signal intensity measurements demonstrate wide limits of observer agreement, unrelated to reader experience but improved using fixed ROIs. (orig.)

  6. Determination of Lead Ion by a Modified Carbon Paste Electrode Based on Multi-Walled Carbon Nanotubes (MWCNTs and Ligand (N-(4-Hydroxyphenyl Ethanamide

    Directory of Open Access Journals (Sweden)

    Marzieh Bagheri

    2015-06-01

    Full Text Available The preparation of a new modified carbon paste electrode (CPE to measure lead ion has been reported in this study. Lead is a highly toxic element which can have a negative impact on the environment. Therefore, measurement of lead in aquatic environments is very important. Although several methods have been developed for determination of lead ion in aquatic environments, there is no a cheap, simple, accurate and rapid method to measure this ion. Aim of this study is to develop a new method to measure the lead based on using multi walls carbon nanotubes (MWCNTs and Paracetamol as an ionophore for modification of a CPE. The optimum composition of modified CPE was determined as 64% of graphite powder, 20% of paraffin oil, 12% of nanotube and 4% of ionophore. This optimum composition was shown high selectivity, with appropriate Nernestian slope (-29.73 mV/decade, linear range (from 1.0×10-1to 1.0×10-8M, low lead concentration detection limit (7.5×10-9M and good response time (equal of 25 sec.The results of this study to introduce a cheap, accurate and simple method for determination of lead ion in aquatic environments.

  7. Determination of Lead Ion by a Modified Carbon Paste Electrode Based on Multi-Walled Carbon Nanotubes (MWCNTs andLigand (N-(4-Hydroxyphenyl Ethanamide

    Directory of Open Access Journals (Sweden)

    Marzieh Bagheri

    2015-06-01

    Full Text Available The preparation of a new modified carbon paste electrode (CPEto measure lead ion has been reported in this study. Lead is a highly toxic element which can have a negative impact on the environment. Therefore, measurement of lead in aquatic environments is very important. Although several methods have been developed for determination of lead ion in aquatic environments, there is no a cheap, simple, accurate and rapid method to measure this ion. Aim of this study is to develop a new method to measure the lead based on using multi walls carbon nanotubes (MWCNTs and Paracetamol as an ionophore for modificationof a CPE.The optimum composition of modified CPE was determined as 64% of graphite powder, 20% of paraffin oil, 12% of nanotube and 4% of ionophore.This optimum composition was shown high selectivity, with appropriate Nernestian slope (-29.73 mV/decade, linear range (from 1.0×10-1to 1.0×10-8M, low lead concentration detection limit (7.5×10-9M and good response time (equal of 25 sec.The results of this study to introduce a cheap, accurate and simple method for determination of lead ion in aquatic environments.

  8. Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall

    NARCIS (Netherlands)

    Giroud, C.; Maddison, G. P.; Jachmich, S.; Rimini, F.; Beurskens, M. N. A.; Balboa, I.; Brezinsek, S.; Coelho, R.; Coenen, J. W.; Frassinetti, L.; Joffrin, E.; Oberkofler, M.; Lehnen, M.; Liu, Y.; Marsen, S.; McCormick, K.; Meigs, A.; Neu, R.; Sieglin, B.; van Rooij, G. J.; Arnoux, G.; Belo, P.; Brix, M.; Clever, M.; Coffey, I.; Devaux, S.; Douai, D.; Eich, T.; Flanagan, J.; S. Grünhagen,; Huber, A.; Kempenaars, M.; Kruezi, U.; Lawson, K.; Lomas, P.; Lowry, C.; Nunes, I.; Sirinnelli, A.; Sips, A.C.C.; Stamp, M.; Wiesen, S.; JET-EFDA Contributors,

    2013-01-01

    This paper reports the impact on confinement and power load of the high-shape 2.5 MA ELMy H-mode scenario at JET of a change from all carbon plasma-facing components to an all metal wall. In preparation to this change, systematic studies of power load reduction and impact on confinement as a result

  9. Mucosal/submucosal blood flow in the gut wall determined by local washout of 133Xenon

    DEFF Research Database (Denmark)

    Mortensen, Peter; Olsen, J; Bülow, J

    1991-01-01

    the initial slope of the washout was used for measuring blood flow rate. Blood flow rate was simultaneously measured by microsphere entrapment technique. There was an excellent correlation between the blood flow rate determined by the two techniques the correlation coefficient R being 0.89 in the small...

  10. Developing LBM Process Parameters for Ti-6Al-4V Thin Wall Structures and Determining the Corresponding Mechanical Characteristics

    Science.gov (United States)

    Ahuja, Bhrigu; Schaub, Adam; Karg, Michael; Lechner, Michael; Merklein, Marion; Schmidt, Michael

    The Laser Beam Melting (LBM) process technology within the family of Additive Manufacturing technology is characterized by its ability to fabricate fully dense 3D structures directly from micro-sized metal powder. With the current state of the art, Ti-6Al-4V has been processed using LBM machine systems constituting a laser with a beam diameter of about 100 μm. In order to fabricate structures with smaller wall thicknesses, processing of Ti-6Al-4V is attempted on the LBM machine system, Realizer SLM 50 consisting of a laser with a beam diameter 10 μm. The proposed paper presents the development of process parameters for fabricating fully dense Ti-6Al-4V 3D structures using the LBM machine system, Realizer SLM 50. Further experiments are carried out to determine the wall thickness and mechanical properties achievable using the selected process parameters. Analysis and scientific arguments are presented to explain the influence of building direction and heat treatment on mechanical properties.

  11. LytR-CpsA-Psr enzymes as determinants of Bacillus anthracis secondary cell wall polysaccharide assembly.

    Science.gov (United States)

    Liszewski Zilla, Megan; Chan, Yvonne G Y; Lunderberg, Justin Mark; Schneewind, Olaf; Missiakas, Dominique

    2015-01-01

    Bacillus anthracis, the causative agent of anthrax, replicates as chains of vegetative cells by regulating the separation of septal peptidoglycan. Surface (S)-layer proteins and associated proteins (BSLs) function as chain length determinants and bind to the secondary cell wall polysaccharide (SCWP). In this study, we identified the B. anthracis lcpD mutant, which displays increased chain length and S-layer assembly defects due to diminished SCWP attachment to peptidoglycan. In contrast, the B. anthracis lcpB3 variant displayed reduced cell size and chain length, which could be attributed to increased deposition of BSLs. In other bacteria, LytR-CpsA-Psr (LCP) proteins attach wall teichoic acid (WTA) and polysaccharide capsule to peptidoglycan. B. anthracis does not synthesize these polymers, yet its genome encodes six LCP homologues, which, when expressed in S. aureus, promote WTA attachment. We propose a model whereby B. anthracis LCPs promote attachment of SCWP precursors to discrete locations in the peptidoglycan, enabling BSL assembly and regulated separation of septal peptidoglycan.

  12. Single-walled carbon nanotubes as stationary phase in gas chromatographic separation and determination of argon, carbon dioxide and hydrogen.

    Science.gov (United States)

    Safavi, Afsaneh; Maleki, Norooz; Doroodmand, Mohammad Mahdi

    2010-08-24

    A chromatographic technique is introduced based on single-walled carbon nanotubes (SWCNTs) as stationary phase for separation of Ar, CO(2) and H(2) at parts per million (ppm) levels. The efficiency of SWCNTs was compared with solid materials such as molecular sieve, charcoal, multi-walled carbon nanotubes and carbon nanofibers. The morphology of SWCNTs was optimized for maximum adsorption of H(2), CO(2) and Ar and minimum adsorption of gases such as N(2), O(2), CO and H(2)O vapour. To control temperature of the gas chromatography column, peltier cooler was used. Mixtures of Ar, CO(2) and H(2) were separated according to column temperature program. Relative standard deviation for nine replicate analyses of 0.2 mL H(2) containing 10 microL of each Ar or CO(2) was 2.5% for Ar, 2.8% for CO(2) and 3.6% for H(2). The interfering effects of CO, and O(2) were investigated. Working ranges were evaluated as 40-600 ppm for Ar, 30-850 ppm for CO(2) and 10-1200 ppm for H(2). Significant sensitivity, small relative standard deviation (RSD) and acceptable limit of detection (LOD) were obtained for each analyte, showing capability of SWCNTs for gas separation and determination processes. Finally, the method was used to evaluate the contents of CO(2) in air sample.

  13. Effects of arterial blood flow on walls of the abdominal aorta: distributions of wall shear stress and oscillatory shear index determined by phase-contrast magnetic resonance imaging.

    Science.gov (United States)

    Sughimoto, Koichi; Shimamura, Yoshiaki; Tezuka, Chie; Tsubota, Ken'ichi; Liu, Hao; Okumura, Kenichiro; Masuda, Yoshitada; Haneishi, Hideaki

    2016-07-01

    Although abdominal aortic aneurysms (AAAs) occur mostly inferior to the renal artery, the mechanism of the development of AAA in relation to its specific location is not yet clearly understood. The objective of this study was to evaluate the hypothesis that even healthy volunteers may manifest specific flow characteristics of blood flow and alter wall shear or oscillatory shear stress in the areas where AAAs commonly develop. Eight healthy male volunteers were enrolled in this prospective study, aged from 24 to 27. Phase-contrast magnetic resonance imaging (MRI) was performed with electrocardiographic triggering. Flow-sensitive four-dimensional MR imaging of the abdominal aorta, with three-directional velocity encoding, including simple morphological image acquisition, was performed. Information on specific locations on the aortic wall was applied to the flow encodes to calculate wall shear stress (WSS) and oscillatory shear index (OSI). While time-framed WSS showed the highest peak of 1.14 ± 0.25 Pa in the juxtaposition of the renal artery, the WSS plateaued to 0.61 Pa at the anterior wall of the abdominal aorta. The OSI peaked distal to the renal arteries at the posterior wall of the abdominal aorta of 0.249 ± 0.148, and was constantly elevated in the whole abdominal aorta at more than 0.14. All subjects were found to have elevated OSI in regions where AAAs commonly occur. These findings indicate that areas of constant peaked oscillatory shear stress in the infra-renal aorta may be one of the factors that lead to morphological changes over time, even in healthy individuals.

  14. Looking beyond School Walls: Examining the Impact of Superintendent Longevity on Teachers' Perceptions of Their Working Conditions

    Science.gov (United States)

    Jordan, Derrick D.

    2012-01-01

    The purpose of this study was to determine if superintendent longevity significantly impacted teachers' perceptions of their working conditions. In addition, the study sought to determine if there were differences in perceptions among teachers whose superintendent was beginning (1 or fewer years in current position), emerging (between 2 to 6 years…

  15. Determination of extra and intracellular content from some lytic enzymes related with carnation (Dianthus caryophyllus L. root cell wall

    Directory of Open Access Journals (Sweden)

    Sixta Tulia Martínez Peralta

    2016-11-01

    Full Text Available The presence of some enzymes related to cell wall (polygalacturonase, the pectate lyase, protease and xylanase in carnation (Dianthus caryophyllus L. roots as well as the activity levels were determined. These levels were analyzed in different cellular places: the intercellular fluid that is part of apoplast, the symplast, and the total level (apoplast and symplast in carnation roots. Two methods were tested to extract the intercellular fluid. To obtain the intracellular content (symplast and total extract (apoplast+symplast, three methods were tested, using as extracting solution  i phosphate buffer, ii phosphate buffer + PVPP,  iii before the extraction with phosphate buffer, the carnation roots were washed with acetone.  The results showed the effect of different extracting solutions in the enzymatic activities and in the protein content. A new only one step method is proposed to extract the four enzymes and make the comparative analysis of enzymatic activity.

  16. Determination of Optimum Thermal Insulation Thicknesses for External Walls Considering the Heating, Cooling and Annual Energy Requirement

    Directory of Open Access Journals (Sweden)

    Ömer KAYNAKLI

    2016-06-01

    Full Text Available In this study, optimization of thermal insulation thickness applied to the external walls of buildings has been carried out comparatively based on the seasonal (space-heating and cooling and the annual energy requirements considering solar radiation effect. This study has been performed for four degree-day regions of Turkey, namely, Iskenderun (in the first region, Istanbul (in the second region, Ankara (in the third region and Ardahan (in the fourth region. By determining the sol-air temperatures for each region and maximizing the present worth value of seasonal and annual energy savings, the optimum thermal insulation thicknesses have been calculated. The effects of solar radiation on heating-cooling energy requirements, the variation of optimum insulation thicknesses and payback periods with respect to degree-day regions, the differences between the analyses based on seasonal and annual have been presented in tabular and graphical form.

  17. Determination of stress-strain state of the wooden church log walls with software package

    Directory of Open Access Journals (Sweden)

    Chulkova Anastasia

    2016-01-01

    Full Text Available The restoration of architectural monuments is going on all over the world today. The main aim of restoration is the renewal of stable functioning of building constructions in normal state. In this article, we have tried to figure out with special software the bearing capacity of log cabins of the Church of Transfiguration on Kizhi island. As shown in research results, determination of stress-strain stage with software package is necessary for the bearing capacity computation as well as field tests.

  18. Impact of inner-wall reflection on UV reactor performance as evaluated by using computational fluid dynamics: The role of diffuse reflection.

    Science.gov (United States)

    Li, Wentao; Li, Mengkai; Bolton, James R; Qu, Jiuhui; Qiang, Zhimin

    2017-02-01

    Making use of the reflected ultraviolet (UV) radiation with a reflective inner wall is a promising way to improve UV reactor performance. In this study, the impact of inner-wall reflection on UV reactor performance was evaluated in annular single-lamp UV reactors by using computational fluid dynamics, with an emphasis on the role of diffuse reflection. The UV radiation inside the reactor chamber was simulated using a calibrated discrete ordinates radiation model, which has been proven to be a reliable tool for modeling fluence rate (FR) distributions in UV reactors with a reflective inner wall. The results show that UV reactors with a highly reflective inner wall (Reflectivity = 0.80) had obviously higher FRs and reduction equivalent fluences (REFs) than those with an ordinary inner wall (Reflectivity = 0.26). The inner-wall diffuse reflection further increased the reactor REF, as a result of the elevated volume-averaged FR. The FR distribution uniformity had conditioned contributions to UV reactor performance. Specifically, in UV reactors with a plug-like flow the FR distribution uniformity contributed to the REF to some extent, while in UV reactors with a mixed flow it had little influence on the REF. This study has evaluated, for the first time, the impact of inner-wall diffuse reflection on UV reactor performance and has renewed the understanding about the contribution of FR distribution uniformity to UV reactor performance.

  19. A general formalism for the determination of the effective mass of the nanoscale structural inhomogeneities of the domain wall in uniaxial ferromagnets.

    Science.gov (United States)

    Shevchenko, Andriy; Barabash, Maksym

    2015-01-01

    On the basis of the method of gyrotropic Thiele forces, we build a formalism that allows the determination of the effective mass of the nanoscales structural elements of the domain wall (DW): vertical Bloch line and Bloch point in uniaxial ferromagnets. As shown, the effective mass of these magnetic inhomogeneities depends on the value of the gyrotropic domain wall bend that is created by their movement.

  20. Contractility studies on isolated bovine choroidal small arteries: determination of the active and passive wall tension-internal circumference relation.

    Science.gov (United States)

    Delaey, C; Boussery, K; Van de Voorde, J

    2002-09-01

    Studies on isolated choroidal arteries could help to understand the regulatory mechanisms in the choroidal circulation. The aim of the present study was therefore to assess whether contractility studies on isolated choroidal arteries were feasible and to determine the active and passive wall tension-internal circumference relation of these arteries. This relation is essential for reliable further pharmacodynamic studies on these vessels. Isolated choroidal arteries were mounted on a wire myograph for isometric tension recording. After the vessel was mounted, the L(100) (the circumference of the vessel at a transmural pressure of 100 mmHg) was determined. Then the passive and active wall tension-internal circumference relation of the choroidal vessels was obtained by stepwise increasing the internal circumference. The changes in the internal circumference were expressed as a percentage of L(100). After each increase in circumference, the passive tone (in a calcium free medium), the spontaneous tone (in a Krebs--Ringer bicarbonate solution) and the active tone (in a solution containing K(+) 120 mM and prostaglandin F(2 alpha) 30 microM) was measured. The passive tone of the vessel increased exponentially with the circumference of the vessel. Both the spontaneous tone and the active tone also increased when the vessel was stretched. They peaked when the internal circumference approached 90% of the L(100) and diminished again when the circumference was further increased. The peak value of the active tension curve averaged 2.24+/-0.47 Nm(-1) (n=10). The passive tension was 0.57+/-0.08 Nm(-1) (n=10) at this circumference. The peak value of the spontaneous tension curve averaged 0.37+/-0.08 Nm(-1) (n=10). It can be concluded that in vitro contractility studies on isolated choroidal arteries are feasible. The optimal length or preload of the choroidal arteries is attained when the internal circumference of the artery is set to 90% of the L(100).

  1. Impact of structural design criteria on first wall surface heat flux limit

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, S. [Argonne National Lab., IL (United States)

    1998-09-01

    The irradiation environment experienced by the in-vessel components of fusion reactors presents structural design challenges not envisioned in the development of existing structural design criteria such as the ASME Code or RCC-MR. From the standpoint of design criteria, the most significant issues stem from the irradiation-induced changes in material properties, specifically the reduction of ductility, strain hardening capability, and fracture toughness with neutron irradiation. Recently, Draft 7 of the ITER structural design criteria (ISDC), which provide new rules for guarding against such problems, was released for trial use by the ITER designers. The new rules, which were derived from a simple model based on the concept of elastic follow up factor, provide primary and secondary stress limits as functions of uniform elongation and ductility. The implication of these rules on the allowable surface heat flux on typical first walls made of type 316 stainless steel and vanadium alloys are discussed.

  2. Determination of the Photon Impact Position within a DROID

    Science.gov (United States)

    Jerjen, I.; Hijmering, R. A.; Verhoeve, P.; Martin, D. D. E.; Kozorezov, A. G.; Venn, R.

    2008-04-01

    Distributed read-out imaging detectors (DROIDs) combine a good energy resolution with a high position resolving power. Therefore they are promising candidates to build cameras with a huge detection area. A new method is proposed to determine the photon energy and impact position from the two signals of a one-dimensional DROID. For this purpose the diffusion equation was solved for asymmetric devices with arbitrarily trapping. The new method is then applied to fit the experimental data obtained from the illumination with soft X-ray of a 400 μm long Ta absorber strip with one Ta/Al read-out STJ at each end.

  3. Electrochemical Behavior and Determination of Chlorogenic Acid Based on Multi-Walled Carbon Nanotubes Modified Screen-Printed Electrode

    Directory of Open Access Journals (Sweden)

    Xiaoyan Ma

    2016-10-01

    Full Text Available In this paper, the multi-walled carbon nanotubes modified screen-printed electrode (MWCNTs/SPE was prepared and the MWCNTs/SPE was employed for the electrochemical determination of the antioxidant substance chlorogenic acids (CGAs. A pair of well-defined redox peaks of CGA was observed at the MWCNTs/SPE in 0.10 mol/L acetic acid-sodium acetate buffer (pH 6.2 and the electrode process was adsorption-controlled. Cyclic voltammetry (CV and differential pulse voltammetry (DPV methods for the determination of CGA were proposed based on the MWCNTs/SPE. Under the optimal conditions, the proposed method exhibited linear ranges from 0.17 to 15.8 µg/mL, and the linear regression equation was Ipa (µA = 4.1993 C (×10−5 mol/L + 1.1039 (r = 0.9976 and the detection limit for CGA could reach 0.12 µg/mL. The recovery of matrine was 94.74%–106.65% (RSD = 2.92% in coffee beans. The proposed method is quick, sensitive, reliable, and can be used for the determination of CGA.

  4. Electrochemical Behavior and Determination of Chlorogenic Acid Based on Multi-Walled Carbon Nanotubes Modified Screen-Printed Electrode

    Science.gov (United States)

    Ma, Xiaoyan; Yang, Hongqiao; Xiong, Huabin; Li, Xiaofen; Gao, Jinting; Gao, Yuntao

    2016-01-01

    In this paper, the multi-walled carbon nanotubes modified screen-printed electrode (MWCNTs/SPE) was prepared and the MWCNTs/SPE was employed for the electrochemical determination of the antioxidant substance chlorogenic acids (CGAs). A pair of well-defined redox peaks of CGA was observed at the MWCNTs/SPE in 0.10 mol/L acetic acid-sodium acetate buffer (pH 6.2) and the electrode process was adsorption-controlled. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods for the determination of CGA were proposed based on the MWCNTs/SPE. Under the optimal conditions, the proposed method exhibited linear ranges from 0.17 to 15.8 µg/mL, and the linear regression equation was Ipa (µA) = 4.1993 C (×10−5 mol/L) + 1.1039 (r = 0.9976) and the detection limit for CGA could reach 0.12 µg/mL. The recovery of matrine was 94.74%–106.65% (RSD = 2.92%) in coffee beans. The proposed method is quick, sensitive, reliable, and can be used for the determination of CGA. PMID:27801797

  5. Determination of peak deflections from human surrogates using chestbands in side impact tests.

    Science.gov (United States)

    Yoganandan, Narayan; Humm, John R; Pintar, Frank A; Maiman, Dennis J

    2013-08-01

    To understand the biomechanics of the human body in motor vehicle environments, physical models including anthropomorphic test devices (ATD) and biological models (postmortem human surrogates) are used, and sled tests are conducted. Deflection is often used as a biomechanical variable to characterize the effects of impact loading and derive injury criteria. The objective of the present study was to evaluate different techniques and recommend a methodology to determine the peak thorax and abdominal deflections from temporal contours using chestbands in oblique lateral impacts. The side impact ATD WorldSID representing human surrogates was positioned on a seat. The seat was rigidly fixed to the platform of an acceleration sled. The oblique load-wall fixed to the sled consisted of separate and adjustable plates to contact the shoulder, thorax, abdomen, and pelvis. Two 59-gage chestbands were wrapped on the thorax and abdomen. Tests were conducted at low, medium, and high velocities (3.4, 6.7, and 7.5m/s) and three methods, termed the spine-sternum, bilateral, and spine-box, were used to determine the global peak deflection and its angulation. Results indicated that all three methods produced very similar angulations, for all velocity tests, and at both thorax and abdominal regions. However, maximum deflections were the lowest in the spine-sternum, followed by bilateral and spine-box methods, with one exception. Based on the development of deflection contours, locations used in the definitions of the origin, and accuracy in identifying critical locations/points in time-varying contours, results of the present study indicate that the bilateral method is the optimum procedure to determine the oblique peak deflection vector in biomechanical tests.

  6. Impact and mitigation of disruptions with the ITER-like wall in JET

    NARCIS (Netherlands)

    Lehnen, M.; Arnoux, G.; Brezinsek, S.; Flanagan, J.; Gerasimov, S. N.; Hartmann, N.; Hender, T. C.; Huber, A.; Jachmich, S.; Kiptily, V.; Kruezi, U.; Matthews, G. F.; Morris, J.; Plyusnin, V. V.; Reux, C.; Riccardo, V.; Sieglin, B.; de Vries, P. C.; JET-EFDA Contributors,

    2013-01-01

    Disruptions are a critical issue for ITER because of the high thermal and magnetic energies that are released on short timescales, which results in extreme forces and heat loads. The choice of material of the plasma-facing components (PFCs) can have significant impact on the loads that arise during

  7. Investigation of High-Speed Erythrocyte Flow and Erythrocyte-Wall Impact in a Lab-on-a-Chip.

    Science.gov (United States)

    Li, Ping; Zheng, Lu; Zhang, Di; Xie, Yonghui; Feng, Yi; Xie, Gongnan

    2016-05-26

    To better understand erythrocyte high-speed motion, collision characteristics, and collision-induced hemolysis probability in rotary blood pumps, a visual experimental investigation of high-speed erythrocyte flow and erythrocyte-wall collision in a lab-on-a-chip was performed. The erythrocyte suspension was driven by a microsyringe pump connected to the microchip, and the erythrocyte flow and erythrocyte-wall impact process were observed and imaged by an optical microscope and a high-speed camera. Two types of microchips with different impact surfaces (flat and curved) were employed. The motion and deformation features before and after collision were studied in detail. The results show that erythrocytes not only move along the flow direction in the flow plane but also rotate and roll in three-dimensional space. Erythrocytes keep discoid shape during the movement in the straight channel, but their deformations during collision are mainly classified into two types: erythrocyte structure is still stable and the erythrocyte performance can be ensured to a certain extent in the TypeA deformation, while the TypeB deformation makes the membrane more likely to fracture on the stretched side, increasing the probability of hemolysis. Furthermore, the movements and deformations of the erythrocytes after collision are analyzed and classified into two types: bouncing and slipping. Moreover, a simulation method for the flow in microchip was performed and validated through a comparison of the streamlines and experimental erythrocytes tracks, which can be further employed to predict the high-speed blood flow, associated with collision process in mechanical blood pump.

  8. Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall

    CERN Document Server

    Giroud, C; Jachmich, S; Rimini, F; Beurskens, M N A; Balboa, I; Brezinsek, S; Coelho, R; Coenen, J W; Frassinetti, L; Joffrin, E; Oberkofler, M; Lehnen, M; Liu, Y; Marsen, S; K, K McCormick; Meigs, A; Neu, R; Sieglin, B; van Rooij, G; Arnoux, G; Belo, P; Brix, M; Clever, M; Coffey, I; Devaux, S; Douai, D; Eich, T; Flanagan, J; Grunhagen, S; Huber, A; Kempenaars, M; Kruezi, U; Lawson, K; Lomas, P; Lowry, C; Nunes, I; Sirinnelli, A; Sips, A C C; Stamp, M; Wiesen, S; contributors, JET-EFDA

    2013-01-01

    This paper reports the impact on confinement and power load of the high-shape 2.5MA ELMy H-mode scenario at JET of a change from an all carbon plasma facing components to an all metal wall. In preparation to this change, systematic studies of power load reduction and impact on confinement as a result of fuelling in combination with nitrogen seeding were carried out in JET-C and are compared to their counterpart in JET with a metallic wall. An unexpected and significant change is reported on the decrease of the pedestal confinement but is partially recovered with the injection of nitrogen.

  9. Determination of true optical absorption and scattering coefficient of wooden cell wall substance by time-of-flight near infrared spectroscopy.

    Science.gov (United States)

    Kitamura, Ryunosuke; Inagaki, Tetsuya; Tsuchikawa, Satoru

    2016-02-22

    The true absorption coefficient (μa) and reduced scattering coefficient (μ´s) of the cell wall substance in Douglas fir were determined using time-of-flight near infrared spectroscopy. Samples were saturated with hexane, toluene or quinolone to minimize the multiple reflections of light on the boundary between pore-cell wall substance in wood. μ´s exhibited its minimum value when the wood was saturated with toluene because the refractive index of toluene is close to that of the wood cell wall substance. The optical parameters of the wood cell wall substance calculated were μa = 0.030 mm(-1) and μ´s= 18.4 mm(-1). Monte Carlo simulations using these values were in good agreement with the measured time-resolved transmittance profiles.

  10. Impact of assembly on signal detection from thin-wall rotors of micro-gyroscopes

    Directory of Open Access Journals (Sweden)

    Hai Li

    2014-03-01

    Full Text Available The assembly of sealed hollow rotors, a key component in achieving liquid-levitated micro-gyroscopes, represents a significant challenge. The rotor is a thin-wall cylinder composed of materials that are only 100-μm thick. Furnace soldering and hand soldering are used to join the work pieces, but produce defects evident from deformations and surface roughness. Modeling and experiments show that the deformation is related to the temperature during assembly and the mode by which heat is applied to the components. Temperature affects the deformation through thermal stress and air pressure on the rotor, but the mode of heating creates a big difference. Surface deformation of the rotor alters the detecting capacitance and introduces uncertainty in detection sensitivity of the gyroscope. Experiments show that at 220°C, furnace soldering of rotors causes a great decrease in detection sensitivity, leading to a relative uncertainty of nearly 40%. In contrast, hand soldering leads to a relative uncertainty of about 5%. Spot heating of the rotor during assembly is much better than total heating as less thermal stress is generated and the air pressure difference is almost eliminated. Lowering the temperature is helpful to as long as the connection is sufficiently strengthened.

  11. On the Impact of Particulate Matter Distribution on Pressure Drop of Wall-Flow Particulate Filters

    Directory of Open Access Journals (Sweden)

    Vicente Bermúdez

    2017-03-01

    Full Text Available Wall-flow particulate filters are a required exhaust aftertreatment system to abate particulate matter emissions and meet current and incoming regulations applying worldwide to new generations of diesel and gasoline internal combustion engines. Despite the high filtration efficiency covering the whole range of emitted particle sizes, the porous substrate constitutes a flow restriction especially relevant as particulate matter, both soot and ash, is collected. The dependence of the resulting pressure drop, and hence the fuel consumption penalty, on the particulate matter distribution along the inlet channels is discussed in this paper taking as reference experimental data obtained in water injection tests before the particulate filter. This technique is demonstrated to reduce the particulate filter pressure drop without negative effects on filtration performance. In order to justify these experimental data, the characteristics of the particulate layer are diagnosed applying modeling techniques. Different soot mass distributions along the inlet channels are analyzed combined with porosity change to assess the new properties after water injection. Their influence on the subsequent soot loading process and regeneration is assessed. The results evidence the main mechanisms of the water injection at the filter inlet to reduce pressure drop and boost the interest for control strategies able to force the re-entrainment of most of the particulate matter towards the inlet channels’ end.

  12. Sensitive amperometric determination of methimazole based on the electrocatalytic effect of rutin/multi-walled carbon nanotube film.

    Science.gov (United States)

    Dorraji, Parisa S; Jalali, Fahimeh

    2015-02-01

    Electrochemical deposition was used to prepare a glassy carbon electrode modified with multi-walled carbon nanotubes and the glycosidic compound, rutin (R/MWCNTs/GCE). Cyclic voltammetry of the modified electrode in aqueous solution (pH8) showed a pair of well-defined, stable and reversible redox peaks with surface confined characteristics. The catechol moiety of rutin produced the voltammetric peaks via a 2 electron, 2 proton mechanism in the range of 0.0-0.4V (vs. Ag/AgCl). The transfer coefficient (α), heterogeneous electron transfer rate constant (ks), and surface concentration (Γ) for R/MWCNTs/GCE were calculated by using the cyclic voltammetric data. The modified electrode showed excellent catalytic activity toward oxidation of methimazole. Fixed-potential amperometry was used for sub-micromolar determination of methimazole at pH8. Linear dependence of anodic current to methimazole concentration was obtained in the range of 0.1-26μM of the drug with a limit of detection at 18nM. The modified electrode retained its initial response for at least 2weeks if stored in dry ambient conditions. The electrode was used for the amperometric determination of methimazole in formulations and spiked blood serum samples, successfully.

  13. Impact of synthesis methods on the transport of single walled carbon nanotubes in the aquatic environment.

    Science.gov (United States)

    Chowdhury, Indranil; Duch, Mathew C; Gits, Colton C; Hersam, Mark C; Walker, Sharon L

    2012-11-06

    In this study, a systematic approach has been followed to investigate the fate and transport of single walled carbon nanotubes (SWCNTs) from synthesis to environmentally relevant conditions. Three widely used SWCNT synthesis methods have been investigated in this study including high pressure carbon monoxide (HiPco), SWeNT CoMoCat, and electric arc discharge technique (EA). This study relates the transport of three SWCNTs (HiPco-D, SG65-D, and P2-D) with different synthesis methods and residual catalyst content revealing their influence on the subsequent fate of the nanotubes. To minimize nanotube bundling and aggregation, the SWCNTs were dispersed using the biocompatible triblock copolymer Pluronic, which allowed the comparison in the transport trends among these SWCNTs. After purification, the residual metal catalyst between the SWCNTs follows the trend: HiPco-D > SG65-D > P2-D. The electrophoretic mobility (EPM) and hydrodynamic diameter of SWCNTs remained insensitive to SWCNT type, pH, and presence of natural organic matter (NOM); but were affected by ionic strength (IS) and ion valence (K(+), Ca(2+)). In monovalent ions, the hydrodynamic diameter of SWCNTs was not influenced by IS, whereas larger aggregation was observed for HiPco-D with IS than P2-D and SG65-D in the presence of Ca(2+). Transport of HiPco-D in the porous media was significantly higher than SG65-D followed by P2-D. Release of HiPco-D from porous media was higher than SG65-D followed by P2-D, though negligible amount of all types of SWCNTs (acidic than SG65-D followed by P2-D, which is similar to the transport trend. Overall, it was observed that the synthesis methods resulted in distinctive breakthrough trends, which were correlated to metal content. These findings will facilitate the safe design of environmental friendly SWCNTs by minimizing mobility in aquatic environments.

  14. Determination of the chest wall thickness as calibration parameter for dosimetric partial-body counting; Bestimmung der Brustwandstaerke als Kalibrierparameter fuer dosimetrische Teilkoerpermessungen

    Energy Technology Data Exchange (ETDEWEB)

    Guen, H. [Fachhochschule Giessen-Friedberg, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz; Karlsruher Institut fuer Technologie, Eggenstein-Leopoldshafen (Germany). Inst. fuer Strahlenforschung; Hegenbart, L. [Karlsruher Institut fuer Technologie, Eggenstein-Leopoldshafen (Germany). Inst. fuer Strahlenforschung; Breckow, J. [Fachhochschule Giessen-Friedberg, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

    2010-05-15

    The authors describe actual partial body measurements with Phoswich detectors in the in-vivo laboratory of the Institute for Technology in Karlsruhe. The chest wall thickness is estimated from the radio of body weight to body length. This formula includes several uncertainties. The aim of the project was the reduction of the uncertainties of the empirical formula using ultrasonography. This method allows an accuracy of plus or minus 1.1 mm for the determined chest wall thickness. Besides the experimental study several voxel models were used to determine the efficiency of modeled measuring systems. The voxel models reach the same accuracy as the ultrasound method.

  15. A multifunctional mannosyltransferase family in Candida albicans determines cell wall mannan structure and host-fungus interactions.

    NARCIS (Netherlands)

    Mora-Montes, H.M.; Bates, S.; Netea, M.G.; Castillo, L.; Brand, A.; Buurman, E.T.; Diaz-Jimenez, D.F.; Kullberg, B.J.; Brown, A.J.; Odds, F.C.; Gow, N.A.

    2010-01-01

    The cell wall proteins of fungi are modified by N- and O-linked mannosylation and phosphomannosylation, resulting in changes to the physical and immunological properties of the cell. Glycosylation of cell wall proteins involves the activities of families of endoplasmic reticulum and Golgi-located gl

  16. Temperature dependence of carrier spin polarization determined from current-induced domain wall motion in a Co/Ni nanowire

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, K.; Koyama, T.; Hiramatsu, R.; Kobayashi, K.; Ono, T. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Chiba, D. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 322-0012 (Japan); Fukami, S. [Green Innovation Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501 (Japan); Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Tanigawa, H.; Suzuki, T. [RENESAS Electronics Corporation, Sagamihara, Kanagawa 252-5298 (Japan); Ohshima, N. [NEC Energy Device Ltd., 1120 Shimokuzawa, Chuo-ku, Sagamihara, Kanagawa 252-5298 (Japan); Ishiwata, N. [Green Innovation Research Laboratories, NEC Corporation, 34 Miyukigaoka, Tsukuba, Ibaraki 305-8501 (Japan); Nakatani, Y. [University of Electro-communications, Chofu, Tokyo 182-8585 (Japan)

    2012-05-14

    We have investigated the temperature dependence of the current-induced magnetic domain wall (DW) motion in a perpendicularly magnetized Co/Ni nanowire at various temperatures and with various applied currents. The carrier spin polarization was estimated from the measured domain wall velocity. We found that it decreased more with increasing temperature from 100 K to 530 K than the saturation magnetization did.

  17. LIME REQUIREMENT DETERMINATION AND LIMING IMPACT ON SOIL NUTRIENT STATUS

    Directory of Open Access Journals (Sweden)

    Krunoslav Karalić

    2010-06-01

    Full Text Available The aim of conducted research was to determine the influence of liming, mineral and organic fertilization on soil chemical properties and nutrient availability in the soil, yield height and mineral composition of alfalfa. Results were used to create regression models for prediction of liming impact on soil chemical properties. Liming and fertilization experiment was sat up in 20 L volume plastic pots with two types of acid soils with different texture from two sites. Ten liming and fertilization treatments were applied in four repetitions. Lime treatments increased soil pH values and decreased hydrolytic acidity. Mineral and organic fertilization affected additional soil acidification. Application of lime intensified mineralization and humus decomposition, while organic fertilization raised humus content. The results showed significant increase of AL-P2O5 and K2O availability. The treatments increased soil Ca concentrations, but at the same time decreased exchangeable Mg concentrations. Soil pH increase resulted in lower Fe, Mn, Zn and Cu availability. Soil CEC was increased by applied treatments. Lime rates increased number and height of alfalfa plants, as well as yield of leaf, stalk increased concentrations of N, P, K and Ca in alfalfa leaf and stalk, but decreased leaf Mg and Fe, Mn, Zn and Cu concentrations. Regression computer models predicted with adequate accuracy P, Fe, Mn, Zn and Cu availability and final pH value as a result of liming and fertilization impact.

  18. A comprehensive ray tracing study on the impact of solar reflections from glass curtain walls.

    Science.gov (United States)

    Wong, Justin S J

    2016-01-01

    To facilitate the investigation of the impact of solar reflection from the façades of skyscrapers to surrounding environment, a comprehensive ray tracing model has been developed using the International Commerce Centre (ICC) in Hong Kong as an example. Taking into account the actual physical dimensions of buildings and meteorological data, the model simulates and traces the paths of solar reflections from ICC to the surrounding buildings, assessing the impact in terms of hit locations, light intensity and the hit time on each day throughout the year. Our analyses show that various design and architectural features of ICC have amplified the intensity of reflected solar rays and increased the hit rates of surrounding buildings. These factors include the high reflectivity of glass panels, their upward tilting angles, the concave profile of the 'Dragon Tail' (glass panels near the base), the particular location and orientation of ICC, as well as the immense height of ICC with its large reflective surfaces. The simulation results allow us to accurately map the date and time when the ray projections occur on each of the target buildings, rendering important information such as the number of converging (overlapping) projections, and the actual light intensity hitting each of the buildings at any given time. Comparisons with other skyscrapers such as Taipei 101 in Taiwan and 2-IFC (International Finance Centre) Hong Kong are made. Remedial actions for ICC and preventive measures are also discussed.

  19. Using infrared thermography to determine the presence and correct placement of grouted cells in single-width concrete masonry unit (CMU) walls

    Science.gov (United States)

    Stockton, Gregory R.; Allen, Lee R.

    1999-03-01

    Determining the placement of reinforcing grout in single-width CMU (Concrete Masonry Unit) walls has, in the past, been a painstaking and destructive undertaking. Usually, a test is performed because -- by accident -- missing cells are discovered when a wall penetration is retrofitted or change order is executed, requiring that the wall be opened. Often, a hammer or hammer drill is used to punch holes where the grouting is supposed to be. The test results are used to extrapolate the extent of the problem. This method falls short, since the sample is so small, that only outright fraud can be found, and excess grouting cannot be determined. This paper discusses the results of a joint effort between Stockton Infrared Thermographic Services, Inc. (SITS) and Allen Applied Infrared Technology, Inc. (AAIT) to produce a methodology for using non-destructive infrared thermography to ensure that the design specifications are being met.

  20. Magnetism-assisted modification of screen printed electrode with magnetic multi-walled carbon nanotubes for electrochemical determination of dopamine.

    Science.gov (United States)

    Zhang, Yong-Mei; Xu, Pei-Li; Zeng, Qiong; Liu, Yi-Ming; Liao, Xun; Hou, Mei-Fang

    2017-05-01

    A simple and sensitive dopamine (DA) electrochemical sensor was fabricated based on magnetism-assisted modification of screen printed electrode (SPE) with magnetic multi-walled carbon nanotubes (mMWCNTs). The mMWCNTs modified electrodes (mMWCNTs/SPE) combines the advantages of SPE and the simultaneous contribution of magnetic nanoparticles (MNPs) and MWCNTs, increasing sensitivity and selectivity of DA detection. The linearity was found between 5μM to 180μM, with the limit of detection (LOD) of 0.43μM. In the mean time, this modified electrode exhibited excellent selectivity for DA detection with almost no interference from ascorbic acid (AA), which co-exists with DA in many bio-samples and causes common interference. Finally, this novel electrode has been applied to determine DA concentration in spiked human blood serum and satisfactory recovery was found in the range of 97.43-102.94% with the RSDs of less than 2.27%. This work developed a sensitive and reliable electrochemical analytical method based on mMWCNTs/SPE, which exhibits great potential for diagnosis of the diseases related to DA.

  1. CeO{sub 2} nanoparticles decorated multi-walled carbon nanotubes for electrochemical determination of guanine and adenine

    Energy Technology Data Exchange (ETDEWEB)

    Wei Yan [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China); Department of Chemistry, Wannan Medical College, Wuhu 241002 (China); Huang Qinan [Department of Chemistry, Wannan Medical College, Wuhu 241002 (China); Li Maoguo [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China); Huang Xingjiu [Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031 (China); Fang Bin, E-mail: binfang_47@yahoo.com.cn [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China); Wang Lun, E-mail: wanglun@mail.ahnu.edu.cn [College of Chemistry and Materials Sciences, Anhui Normal University, Wuhu 241000 (China)

    2011-10-01

    Sub-10 nm CeO{sub 2} nanoparticles decorated multi-walled carbon nanotubes has been constructed for electrochemial determination of guanine and adenine. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to characterize the nanoparticles CeO{sub 2}/MWCNTs. Electrochemical impedance spectroscopy (EIS) was used to characterize the electrode modifying process. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the electrocatalytic activity toward the electrochemical oxidation of guanine and adenine. The detection limit (S/N = 3) for adenine and guanine was found to be 20 and 10 nM, respectively. The obtained sensitivity toward guanine and adenine was 1.26 and 1.13 {mu}A/{mu}M in the linear concentration range 5-50 {mu}M and 5-35 {mu}M, respectively. These results demonstrate that the carbon nanotubes could provide huge locations and facilitate the adsorptive accumulation of the guanine and adenine, and the CeO{sub 2} nanoparticles are promising substrates for the development of high-performance electrocatalysts for biosensing.

  2. The Role of Nonlocal Sediment Transport in Shaping Impact Crater Walls on Earth and Mars

    Science.gov (United States)

    Abbott, A. M.; Furbish, D. J.

    2013-12-01

    With increasing interest in the concept of ';nonlocal' sediment transport on steep, regolith covered hillslopes, clearer connections between theoretical formulations of nonlocal transport and natural landforms are needed. Scree slopes that form within impact craters provide useful, interesting study sites, due in part to their reasonably well-known initial morphologies. Recent research also suggests that the surface of Mars may be more erosionally active than previously thought. By using elevations derived from LiDAR data for Earth and HiRISE images for Mars together with a probabilistic description of nonlocal transport that includes entrainment and disentrainment rates, comparisons are made between Barringer Meteorite Crater in Arizona and Martian craters of various ages. This enables commentary on whether nonlocal transport produces similar slopes, despite the differing transport processes and acceleration due to gravity for the two planets. Physical insight is obtained through laboratory experiments where gravel particles are dropped on a loose granular slope composed of similar sized gravel inclined at different slopes, including the angle of repose and a flat layer of gravel. Total travel distances were obtained for approximately 500 particles dropped from three different heights for each slope angle. The resulting distributions of travel distances are exponential-like, but for steeper slopes these distributions may decay less rapidly than an exponential function, indicating a decreasing likelihood of disentrainment with increasing travel distance. These approximately dynamically scaled experiments will help clarify the relationship between drop height, slope, surface roughness, and mean travel distance. A description of the disentrainment rate based partly on these findings will to be incorporated in a numerical model that simulates impact crater erosion for Earth and Mars. This will test the theoretical similarity of two locations that are physically very

  3. Finite Element Simulation of Axial Crush of Thin-Walled Tubes with Different Cross-Sections: Vehicle/Pole Impact Applications

    National Research Council Canada - National Science Library

    Ahmed Elmarakbi; Niki Fielding; Homayoun Hadavinia

    2011-01-01

    ... the explicit finite element code LS-DYNA. Results compare the absorbed energy and the deflection of each variable, and recommend best design for the tube structure which improved vehicle crashworthiness. KEYWORDS: Energy absorption; thin-walled structures; vehicle impact; finite element analysis; design optimization 1. Introduction Currently within the UK there ar...

  4. Ecotoxicity of single-wall carbon nanotubes to freshwater snail Lymnaea luteola L.: Impacts on oxidative stress and genotoxicity.

    Science.gov (United States)

    Ali, Daoud; Ahmed, Mukhtar; Alarifi, Saud; Ali, Huma

    2015-01-01

    Mammalian studies have raised concerns about the toxicity of carbon nanotubes, but there is very limited data on ecogenotoxicity to aquatic organisms. The aim of this study was to determine eco-geno toxic effects of single walled carbon nanotubes (SWCNTs) in fresh water snail, Lymnea luteola (L. luteola). A static test system was used to expose L. luteola to a freshwater control, 0.05, 0.15, 0.30, 0.46 mg/L SWCNTs for up to 4 days. SWCNTs changed a significant reduction in glutathione, glutathione-S-transferase, and glutathione peroxidase with in hepatopancreas of L. luteola. Lipid peroxidation (LPO) and catalase showed dose- and time-dependent and statistically significant increase in hepatopancreas during SWCNTs exposure compared with control. However, a significant (p snail L. luteola. The oxidative stress and comet assay can successfully be used as sensitive tools of aquatic pollution biomonitoring.

  5. Determining the impacts of fermentative bacteria on wollastonite dissolution kinetics.

    Science.gov (United States)

    Salek, S S; Kleerebezem, R; Jonkers, H M; Voncken, J H L; van Loosdrecht, M C M

    2013-03-01

    Silicate minerals can be a source of calcium and alkalinity, enabling CO2 sequestration in the form of carbonates. For this to occur, the mineral needs to be first dissolved in an acidifying process such as the biological process of anaerobic fermentation. In the present study, the main factors which govern the dissolution process of an alkaline silicate mineral (wollastonite, CaSiO3) in an anaerobic fermentation process were determined. Wollastonite dissolution kinetics was measured in a series of chemical batch experiments in order to be able to estimate the required amount of alkaline silicate that can neutralize the acidifying fermentation process. An anaerobic fermentation of glucose with wollastonite as the neutralizing agent was consequently performed in a fed-batch reactor. Results of this experiment were compared with an abiotic (control) fed-batch reactor in which the fermentation products (i.e. organic acids and alcohols) were externally supplied to the system at comparable rates and proportions, in order to provide chemical conditions similar to those during the biotic (fermentation) experiment. This procedure enabled us to determine whether dissolution of wollastonite was solely enhanced by production of organic acids or whether there were other impacts that fermentative bacteria could have on the mineral dissolution rate. The established pH profiles, which were the direct indicator of the dissolution rate, were comparable in both experiments suggesting that the mineral dissolution rate was mostly influenced by the quantity of the organic acids produced.

  6. Determination of magnetic anisotropy constants and domain wall pinning energy of Fe/MgO(001) ultrathin film by anisotropic magnetoresistance.

    Science.gov (United States)

    Hu, Bo; He, Wei; Ye, Jun; Tang, Jin; Zhang, Yong-Sheng; Ahmad, Syed Sheraz; Zhang, Xiang-Qun; Cheng, Zhao-Hua

    2015-09-15

    It is challenging to determine domain wall pinning energy and magnetic anisotropy since both coherent rotation and domain wall displacement coexist during magnetization switching process. Here, angular dependence anisotropic magnetoresistance (AMR) measurements at different magnetic fields were employed to determine magnetic anisotropy constants and domain wall pinning energy of Fe/MgO(001) ultrathin film. The AMR curves at magnetic fields which are high enough to ensure the coherent rotation of magnetization indicate a smooth behavior without hysteresis between clockwise (CW) and counter-clockwise (CCW) rotations. By analyzing magnetic torque, the magnetic anisotropy constants can be obtained. On the other hand, the AMR curves at low fields show abrupt transitions with hysteresis between CW and CCW rotations, suggesting the presence of multi-domain structures. The domain wall pinning energy can be obtained by analyzing different behaviors of AMR. Our work suggests that AMR measurements can be employed to figure out precisely the contributions of magnetic anisotropy and domain wall pinning energy, which is still a critical issue for spintronics.

  7. Functional regions of Candida albicans hyphal cell wall protein Als3 that determine interaction with the oral bacterium Streptococcus gordonii.

    Science.gov (United States)

    Bamford, Caroline V; Nobbs, Angela H; Barbour, Michele E; Lamont, Richard J; Jenkinson, Howard F

    2015-01-01

    The opportunistic pathogen Candida albicans colonizes the oral cavity and gastrointestinal tract. Adherence to host cells, extracellular matrix and salivary glycoproteins that coat oral surfaces, including prostheses, is an important prerequisite for colonization. In addition, interactions of C. albicans with commensal oral streptococci are suggested to promote retention and persistence of fungal cells in mixed-species communities. The hyphal filament specific cell wall protein Als3, a member of the Als protein family, is a major determinant in C. albicans adherence. Here, we utilized site-specific in-frame deletions within Als3 expressed on the surface of heterologous Saccharomyces cerevisiae to determine regions involved in interactions of Als3 with Streptococcus gordonii. N-terminal region amino acid residue deletions Δ166-225, Δ218-285, Δ270-305 and Δ277-286 were each effective in inhibiting binding of Strep. gordonii to Als3. In addition, these deletions differentially affected biofilm formation, hydrophobicity, and adherence to silicone and human tissue proteins. Deletion of the central repeat domain (Δ434-830) did not significantly affect interaction of Als3 with Strep. gordonii SspB protein, but affected other adherence properties and biofilm formation. Deletion of the amyloid-forming region (Δ325-331) did not affect interaction of Als3 with Strep. gordonii SspB adhesin, suggesting this interaction was amyloid-independent. These findings highlighted the essential function of the N-terminal domain of Als3 in mediating the interaction of C. albicans with S. gordonii, and suggested that amyloid formation is not essential for the inter-kingdom interaction.

  8. Electrochemical determination of sulphide at multi-walled carbon nanotubes-dihexadecyl hydrogen phosphate composite film modified electrodes based on in situ synthesis of methylene blue

    Institute of Scientific and Technical Information of China (English)

    An Min Xiang; Li Zhou; Cheng Guo Hu; Sheng Shui Hu

    2008-01-01

    A novel electrochemical method for the determination of sulphide at a multi-walled carbon nanotube-dihexadecyl hydrogenphosphate composite film coated glassy carbon electrode (MWNTs-DHP/GCE) based on in situ synthesis of methylene blue (MB)was established.

  9. THE IMPACT OF WALL ROUGHNESS OF THE UNDERGROUND AIRWAYS ON THE VALUE OF HYDRAULIC FRICTION FACTOR

    Directory of Open Access Journals (Sweden)

    Vladimir Rendulić

    1991-12-01

    Full Text Available The studies of turbulent flows in round pipes resulted in many hydraulic formulas up to these days, which can also serve in projecting to calculate the resistance to the air flow in underground openings. The report discusses the way of establishing the hydraulic friction factor of untimbered underground workings when the value of equivalent roughness is obtained by measuring the ventilation parameters in a similar working of some other mine. A double reticular nomogram has been constructed for the fast determination of friction coefficient from the known roughness of an underground working (the paper is published in Croatian.

  10. The impact of an underground cut-off wall on nutrient dynamics in groundwater in the lower Wang River watershed, China.

    Science.gov (United States)

    Kang, Pingping; Xu, Shiguo

    2017-03-01

    Underground cut-off walls in coastal regions are mainly used to prevent saltwater intrusion, but their impact on nutrient dynamics in groundwater is not clear. In this study, a combined analysis of multiple isotopes ([Formula: see text]) and nitrogen and phosphorus concentrations is used in order to assess the impact of the underground cut-off walls on the nutrient dynamics in groundwater in the lower Wang River watershed, China. Compared with the nitrogen and phosphorus concentrations in groundwater downstream of the underground cut-off walls, high [Formula: see text] and total dissolved nitrogen concentrations and similar concentration levels of [Formula: see text] and total dissolved phosphorus are found in groundwater upstream of the underground cut-off walls. The isotopic data indicated the probable occurrence of denitrification and nitrification processes in groundwater upstream, whereas the fingerprint of these processes was not shown in groundwater downstream. The management of fertilizer application is critical to control nitrogen concentrations in groundwater restricted by the underground cut-off walls.

  11. Determination of multi-walled carbon nanotube bioaccumulation in earthworms measured by a microwave-based detection technique

    Science.gov (United States)

    Reliable quantification techniques for carbon nanotubes (CNTs) are limited. In this study, a new procedure was developed for quantifying multi-walled carbon nanotubes (MWNTs) in earthworms (Eisenia fetida) based on freeze drying and microwave-induced heating. Specifically, earthw...

  12. Determination of multi-walled carbon nanotube bioaccumulation in earthworms measured by a microwave-based detection technique

    Science.gov (United States)

    Reliable quantification techniques for carbon nanotubes (CNTs) are limited. In this study, a new procedure was developed for quantifying multi-walled carbon nanotubes (MWNTs) in earthworms (Eisenia fetida) based on freeze drying and microwave-induced heating. Specifically, earthw...

  13. The Vibration Impact Determination of the Helicopter Structural Components

    Directory of Open Access Journals (Sweden)

    Khaksar Zeinab

    2017-01-01

    Full Text Available This paper presents the determination of the vibration impact of the helicopter structural components and skin repairs in terms of frequency characteristics. To address this issue, a 3D Finite Element Method (FEM model of 349 Gazelle helicopter has been developed in ABAQUS and the frequency analysis is conducted. The results on the natural frequencies of the full structure reasonably match with the literature giving confidence in the baseline model. The main advantage of this FEM model is that, it can be used to predict the natural frequencies of the full structure, precisely. In addition, the material properties and conditions of the components can be updated based on the applied conditions during the repair and maintenance period. Thus, the model gives a comprehensive design tool for analysing the frequencies of the helicopter with differing components. The effective variations in the frequency changes due to repair are predicted numerically. The discussion of these results helps in developing leads to improved selection of replacement materials and their properties.

  14. Biomass enzymatic saccharification is determined by the non-KOH-extractable wall polymer features that predominately affect cellulose crystallinity in corn.

    Directory of Open Access Journals (Sweden)

    Jun Jia

    Full Text Available Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at p<0.05 & 0.01, but hemicelluloses did not show any significant impact on hexoses yields. Comparative analysis of five standard pairs of corn samples indicated that cellulose and lignin should not be the major factors on biomass saccharification after pretreatments with NaOH and H2SO4 at three concentrations. Notably, despite that the non-KOH-extractable residues covered 12%-23% hemicelluloses and lignin of total biomass, their wall polymer features exhibited the predominant effects on biomass enzymatic hydrolysis including Ara substitution degree of xylan (reverse Xyl/Ara and S/G ratio of lignin. Furthermore, the non-KOH-extractable polymer features could significantly affect lignocellulose crystallinity at p<0.05, leading to a high biomass digestibility. Hence, this study could suggest an optimal approach for genetic modification of plant cell walls in bioenergy corn.

  15. 7 CFR 1940.314 - Criteria for determining a significant environmental impact.

    Science.gov (United States)

    2010-01-01

    ... Program § 1940.314 Criteria for determining a significant environmental impact. (a) EISs will be done for... proposal's area of environmental impact, other related or similarly located Federal actions, and non... relatively few environmental impacts but create a potential for significantly impacts on a cumulative basis...

  16. Pulsatile flow characterization in a vessel phantom with elastic wall using ultrasonic particle image velocimetry technique: the impact of vessel stiffness on flow dynamics.

    Science.gov (United States)

    Qian, Ming; Niu, Lili; Wong, Kelvin Kian Loong; Abbott, Derek; Zhou, Qifa; Zheng, Hairong

    2014-09-01

    This study aims to experimentally investigate the impact of vessel stiffness on the flow dynamics of pulsatile vascular flow. Vessel phantoms with elastic walls were fabricated using polyvinyl alcohol cryogel to result in stiffness ranging from 60.9 to 310.3 kPa and tested with pulsatile flows using a flow circulation set-up. Two-dimensional instantaneous and time-dependent flow velocity and shear rate vector fields were measured using ultrasonic particle image velocimetry (EchoPIV). The waveforms of peak velocities measured by EchoPIV were compared with the ultrasonic pulse Doppler spectrum, and the measuring accuracy was validated. The cyclic vessel wall motion and flow pressure were obtained as well. The results showed that vessel stiffening influenced the waveforms resulting from vessel wall distension and flow pressure, and the fields of flow velocity and shear rate. The stiffer vessel had smaller inner diameter variation, larger pulse pressure and median pressure. The velocity and shear rate maximized at peak systole for all vessels. The results showed a decrease in wall shear stress for a stiffer vessel, which can initiate the atherosclerotic process. Our study elucidates the impact of vessel stiffness on several flow dynamic parameters, and also demonstrates the EchoPIV technique to be a useful and powerful tool in cardiovascular research.

  17. Determination of an Test Condition for IR Thermography to Inspect a Wall-Thinning Defect in Nuclear Piping Components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Weon; Yun, Won Kyung; Jung, Hyun Chul; Kim, Kyeong Suk [Chosun University, Gwnagju (Korea, Republic of)

    2012-02-15

    This study conducted infrared (IR) thermography tests using pipe and plate specimens with artificial wall-thinning defects to find an optimal condition for IR thermography test on the wall-thinned nuclear piping components. In the experiment halogen lamp was used to heat the specimens. The distance between the specimen and the lamp and the intensity of halogen lamp were regarded as experimental parameter. When the distance was set to 1{approx}2 m and the lamp intensity was above 60 % of full power, a single scanning of IR thermography detected all artificial wall-thinning defects, whose minimum dimension was 2{theta} = 90 .deg., d/t=0.5, and L/D{sub o}, within the pipe of 500 mm in length. Regardless of the distance between the specimen and the lamp, the image of wall-thinning defect in IR thermography became distinctive as the intensity of halogen lamp increased. The detectability of IR thermography was similar for both plate and pipe specimens, but the optimal test condition for IR thermography depended on the type of specimen.

  18. RAPID 2D NMR METHOD FOR DETERMINING P-COUMARATE AND FERULATE LEVELS IN CORN (AND OTHER GRASS) CELL WALLS

    Science.gov (United States)

    Grass cell wall components are acylated by the hydroxycinnamates p-coumarate and ferulate. p-Coumarates largely acylate lignin sidechains, exclusively at the gamma-position, whereas ferulates primarily acylate the arabinosyl C5-position of arabinoxylans. Such components can be quantified as the corr...

  19. Determinant representation of the domain-wall boundary condition partition function of a Richardson-Gaudin model containing one arbitrary spin

    Science.gov (United States)

    Faribault, Alexandre; Tschirhart, Hugo; Muller, Nicolas

    2016-05-01

    In this work we present a determinant expression for the domain-wall boundary condition partition function of rational (XXX) Richardson-Gaudin models which, in addition to N-1 spins \\frac{1}{2}, contains one arbitrarily large spin S. The proposed determinant representation is written in terms of a set of variables which, from previous work, are known to define eigenstates of the quantum integrable models belonging to this class as solutions to quadratic Bethe equations. Such a determinant can be useful numerically since systems of quadratic equations are much simpler to solve than the usual highly nonlinear Bethe equations. It can therefore offer significant gains in stability and computation speed.

  20. Impact of Fractionation and Dose in a Multivariate Model for Radiation-Induced Chest Wall Pain

    Energy Technology Data Exchange (ETDEWEB)

    Din, Shaun U. [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Williams, Eric L.; Jackson, Andrew [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Rosenzweig, Kenneth E. [Department of Radiation Oncology, Mount Sinai Medical Center, New York, New York (United States); Wu, Abraham J.; Foster, Amanda [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Yorke, Ellen D. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Rimner, Andreas, E-mail: rimnera@mskcc.org [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

    2015-10-01

    Purpose: To determine the role of patient/tumor characteristics, radiation dose, and fractionation using the linear-quadratic (LQ) model to predict stereotactic body radiation therapy–induced grade ≥2 chest wall pain (CWP2) in a larger series and develop clinically useful constraints for patients treated with different fraction numbers. Methods and Materials: A total of 316 lung tumors in 295 patients were treated with stereotactic body radiation therapy in 3 to 5 fractions to 39 to 60 Gy. Absolute dose–absolute volume chest wall (CW) histograms were acquired. The raw dose-volume histograms (α/β = ∞ Gy) were converted via the LQ model to equivalent doses in 2-Gy fractions (normalized total dose, NTD) with α/β from 0 to 25 Gy in 0.1-Gy steps. The Cox proportional hazards (CPH) model was used in univariate and multivariate models to identify and assess CWP2 exposed to a given physical and NTD. Results: The median follow-up was 15.4 months, and the median time to development of CWP2 was 7.4 months. On a univariate CPH model, prescription dose, prescription dose per fraction, number of fractions, D83cc, distance of tumor to CW, and body mass index were all statistically significant for the development of CWP2. Linear-quadratic correction improved the CPH model significance over the physical dose. The best-fit α/β was 2.1 Gy, and the physical dose (α/β = ∞ Gy) was outside the upper 95% confidence limit. With α/β = 2.1 Gy, V{sub NTD99Gy} was most significant, with median V{sub NTD99Gy} = 31.5 cm{sup 3} (hazard ratio 3.87, P<.001). Conclusion: There were several predictive factors for the development of CWP2. The LQ-adjusted doses using the best-fit α/β = 2.1 Gy is a better predictor of CWP2 than the physical dose. To aid dosimetrists, we have calculated the physical dose equivalent corresponding to V{sub NTD99Gy} = 31.5 cm{sup 3} for the 3- to 5-fraction groups.

  1. Examination of Single-Walled Carbon Nanotubes Uptake and Toxicity from Dietary Exposure: Tracking Movement and Impacts in the Gastrointestinal System

    OpenAIRE

    Bisesi, Joseph H.; Thuy Ngo; Satvika Ponnavolu; Keira Liu; Candice M. Lavelle; Nabiul Afrooz, A. R. M.; Saleh, Navid B.; P. Lee Ferguson; Denslow, Nancy D.; Tara Sabo-Attwood

    2015-01-01

    Previous studies indicate that exposure of fish to pristine single-walled carbon nanotubes (SWCNTs) by oral gavage, causes no overt toxicity, and no appreciable absorption has been observed. However, in the environment, SWCNTs are likely to be present in dietary sources, which may result in differential impacts on uptake and biological effects. Additionally, the potential of these materials to sorb nutrients (proteins, carbohydrates, and lipids) while present in the gastrointestinal (GI) trac...

  2. unemployment in urban ethiopia: determinants and impact on ...

    African Journals Online (AJOL)

    Eyerusalem

    population growth and increased poverty, it has a significant impact on growth and ... 2010). High level of unemployment rates can also contribute to the spread of. HIV/AIDS .... found that unemployment is negatively related to inflation. Another ...

  3. Use of an infrared detector to analyze the temperature evolution of a droplet impacting on a heating wall

    Science.gov (United States)

    Amiel, Clarisse; Le Clercq, Patrick; Ravel, Olivier; Lavergne, Gerard; Berthoumieu, Pierre; Farre, Jean A.

    2001-03-01

    The improvement of the combustion performance in combustor engines in terms of the reduction of the pollutant emissions is an important objective in Automotive and Aerospace Research and Development. Many phenomena occur during the spray injection in the combustor engine: droplet turbulent dispersion, droplet wall interaction, droplets interaction, droplet evaporation, primary and secondary breakup, auto- ignition, combustion, etc. To improve and to validate the heat exchange models between the droplet and a heated wall, an experimental set-up is developed at the ONERA Toulouse Centre on fundamental studies involving single droplets. An Infrared detector measures the temperature evolution of the surface droplet which impinges on a heated wall.

  4. Simultaneous Determination of Parathion, Malathion, Diazinon, and Pirimiphos Methyl in Dried Medicinal Plants Using Solid-Phase Microextraction Fibre Coated with Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Reza Ahmadkhaniha

    2012-01-01

    Full Text Available A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r2≥0.993 over the concentration ranges from 1.5 to 300 ng g−1, and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g−1. For parathion and malathion, the linear range and limit of detection were 2.5–300 (r2≥0.991 and 0.5 ng g−1, respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350∘C, and longer lifespan (over 250 times than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples.

  5. MRI-determined carotid artery flow velocities and wall shear stress in a mouse model of vulnerable and stable atherosclerotic plaque.

    Science.gov (United States)

    van Bochove, Glenda S; Straathof, Roel; Krams, Rob; Nicolay, Klaas; Strijkers, Gustav J

    2010-04-01

    We report here on the pre-clinical MRI characterization of an apoE-/- mouse model of stable and vulnerable carotid artery atherosclerotic plaques, which were induced by a tapered restriction (cast) around the artery. Specific focus was on the quantification of the wall shear stress, which is considered a key player in the development of the plaque phenotype. In vivo MRI was performed at 9.4 T. The protocol consisted of time-of-flight angiography, high-resolution T1- and T2-weighted black-blood imaging and phase-contrast flow velocity imaging as function of time in the cardiac cycle. Wall shear stress was determined by fitting the flow profile to a quadratic polynomial. Time-of-flight angiography confirmed preservation of blood flow through the carotid arteries in all cases. T1- and T2-weighted MRI resulted in high-resolution images in which the position of the cast, luminal narrowing introduced by cast and plaque, as well as the arterial wall could be well identified. Laminar flow with low wall shear stress (11.2+/- 5.2 Pa) was measured upstream to the cast at the position of the vulnerable plaque. Downstream to the cast at the position of the stable plaque, the apparent velocities were low, which is consistent with vortices and an oscillatory nature of the flow. Flow velocities and wall shear stress were successfully measured in this mouse model of stable and unstable plaque. The presented tools can be used to provide valuable insights in the pathogenesis of atherosclerosis.

  6. Determining the Impact of Online Practicum Facilitation for Inservice Teachers

    Science.gov (United States)

    Frey, Timothy

    2008-01-01

    This study investigated the impact of a project-based graduate practicum experience that was facilitated online. The study investigated the effects of the online practicum experience by: (a) using quantitative data to assess the learning and professional growth of the practicum participants in comparison to a group of teachers that did not…

  7. Cell Wall Proteome

    OpenAIRE

    Boudart, Georges; Minic, Zoran; Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth; Pont-Lezica, Rafael F

    2007-01-01

    In this chapter, we will focus on the contribution of proteomics to the identification and determination of the structure and function of CWPs as well as discussing new perspectives in this area. The great variety of proteins found in the plant cell wall is described. Some families, such as glycoside hydrolases, proteases, lectins, and inhibitors of cell wall modifying enzymes, are discussed in detail. Examples of the use of proteomic techniques to elucidate the structure of various cell wall...

  8. DETERMINING ROAD LIGHTING IMPACT ON TRAFFIC STREAM CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Ben-Edigbe Johnnie

    2013-01-01

    Full Text Available The study is aimed at estimating road lighting impact on traffic stream characteristics; flow, speed, density and headway for an uninterrupted traffic flow. Volume, speed and headway data were collected during daylight, road lighting and dry weather conditions. Flowrate, speed, density and headways were estimated for daylight and road lighting periods; then compared. Since flowrate, free-flow speed, optimum speed critical density and headways during daylight and road lighting periods did not differ significantly: the study concluded that road lighting does not affect traffic stream characteristics significantly.

  9. Determining the Publication Impact of a Digital Library

    Science.gov (United States)

    Kaplan, Nancy R.; Nelson, Michael L.

    2000-01-01

    We attempt to assess the publication impact of a digital library (DL) of aerospace scientific and technical information (STI). The Langley Technical Report Server (LTRS) is a digital library of over 1,400 electronic publications authored by NASA Langley Research Center personnel or contractors and has been available in its current World Wide Web (WWW) form since 1994. In this study, we examine calendar year 1997 usage statistics of LTRS and the Center for AeroSpace Information (CASI), a facility that archives and distributes hard copies of NASA and aerospace information. We also perform a citation analysis on some of the top publications distributed by LTRS. We find that although LTRS distributes over 71,000 copies of publications (compared with an estimated 24,000 copies from CASI), citation analysis indicates that LTRS has almost no measurable publication impact. We discuss the caveats of our investigation, speculate on possible different models of usage facilitated by DLs , and suggest retrieval analysis as a complementary metric to citation analysis. While our investigation failed to establish a relationship between LTRS and increased citations and raises at least as many questions as it answers, we hope it will serve as a invitation to, and guide for, further research in the use of DLs.

  10. Arterial bending angle and wall morphology correlate with slow coronary flow: Determination with multidetector CT coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Kantarci, Mecit, E-mail: akkanrad@hotmail.com [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Guendogdu, Fuat [Department of Cardiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Doganay, Selim [Department of Radiology, Medical Faculty, Erciyes University, Kayseri (Turkey); Duran, Cihan [Department of Radiology, Bilim University, Florence Nightingale Hospital, Istanbul (Turkey); Kalkan, M. Emin [Department of Cardiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Sagsoz, M. Erdem [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Kucuk, Osman [Department of Electronic Engineering, Engineering Faculty, Atatuerk University, Erzurum (Turkey); Karakaya, Afak [Department of Radiology, Medical Faculty, Atatuerk University, Erzurum (Turkey); Kucuk, Ahmet [Department of Mathematics, Science Faculty, Atatuerk University, Erzurum (Turkey); Akguen, Metin [Department of Chest, Medical Faculty, Atatuerk University, Erzurum (Turkey)

    2011-01-15

    Background and purpose: The purpose of this study was to assess angulations and vessel wall morphology that could lead to bending head loss in the RCA and LMCA arteries of patients with slow coronary flow (SCF) evaluated by MDCT coronary angiography. Methods: The study involved 51 patients (45 males, mean age: 59.6 years) who were diagnosed with SCF by coronary angiography. Diagnosis of SCF was based on thrombolysis in myocardial infarction (TIMI) frame count. Fifty-one patients with absence of slow flow were selected as the control group. The angulations of the main coronary arteries with the aorta were measured from the axial images obtained through MDCT coronary angiography, and the findings were recorded. In addition, the coronary artery walls of these patients were evaluated. For statistical analysis, SPSS for Windows 10.0 (SPSS Inc., Chicago, IL) was used. For comparisons of the angles, either independent samples t test or the Mann-Whitney U test was used where appropriate. Results: The results of the study indicated that 38 patients had SCF in the LAD. Comparisons of patients with SCF with the controls revealed that in the patients with SCF, the mean angle of the LMCA with the aorta (40.9 {+-} 20.5{sup o}) was statistically significantly smaller than the mean angle of the LMCA with the aorta in the control cases (71.8 {+-} 11{sup o}). In 12 patients, slow flow was detected in the RCA. Those with slow flow in the RCA had significantly smaller angles (mean: 33.2 {+-} 20.4{sup o}) than the other cases (mean: 78.9 {+-} 10.7{sup o}). Conclusion: A small angle of origin of the main coronary arteries from the aorta, measured on MDCT examinations is correlated with slow blood flow in those vessels, as calculated by the TIMI frame count in catheter coronary angiography.

  11. Experimental determination of temperatures of the inner wall of a boiler combustion chamber for the purpose of verification of a CFD model

    Directory of Open Access Journals (Sweden)

    Petr Trávníček

    2011-01-01

    Full Text Available The paper focuses on the non-destructive method of determination of temperatures in the boiler combustion chamber. This method proves to be significant mainly as regards CFD (Computational Fluid Dynamics simulations of combustion processes, in case of which it is subsequently advisable to verify the data calculated using CFD software application with the actually measured data. Verification of the method was based on usage of reference combustion equipment (130 kW which performs combustion of a mixture of waste sawdust and shavings originating in the course of production of wooden furniture. Measuring of temperatures inside the combustion chamber is – considering mainly the high temperature values – highly demanding and requires a special type of temperature sensors. Furthermore, as regards standard operation, it is not possible to install such sensors without performing structural alterations of the boiler. Therefore, for the purpose of determination of these temperatures a special experimental device was constructed while exploiting a thermal imaging system used for monitoring of the surface temperature of outer wall of the reference boiler. Temperatures on the wall of the boiler combustion chamber were determined on the basis of data measured using the experimental device as well as data from the thermal imaging system. These values might serve for verification of the respective CFD model of combustion equipment.

  12. Determinants and Duration of Impact of Early Gut Bacterial Colonization.

    Science.gov (United States)

    Edwards, Christine Ann

    2017-01-01

    An increasing number of studies show low diversity of the gut microbiome in those with chronic diseases such as obesity, inflammatory bowel disease, and allergy. Manipulation of the microbiota may promote health. However, the adult microbiota is stable and may be difficult to change. Understanding the fixed and modifiable factors, which determine colonization in early life, may provide strategies for acquisition of a health-promoting microbiome. Not enough is known about the long-term effects of established determinants of gut colonization, including delivery mode, perinatal antibiotics, and infant diet. It has been suggested that weaning onto solid diet containing non-digestible carbohydrates and cessation of breastfeeding are key stages in the colonization process. In addition, the microbiome of the placenta, amniotic fluid, and breast milk, alongside vaginal and fecal bacteria, may aid the transfer of maternal bacteria to the infant. However, methodological issues such as contamination during collection and/or analysis should be considered. Key Messages: The factors determining early colonization are becoming more evident. However, longitudinal studies of microbiome maturation into late childhood and adulthood are required. The nutrition and health status of the mother before, during, and after birth may be major factors in the early colonization of the infant. © 2017 S. Karger AG, Basel.

  13. Impact of managers' personal determinants in notifying workplace hazards.

    Science.gov (United States)

    Rabin, S; Feiner, M; Shaham, J; Yekutieli, D; Ribak, J

    1998-05-01

    Notification about work hazards is a legal requirement in advanced industrial countries, but workers have claimed, that in many cases, they do not receive enough information regarding risks, exposure, and medical problems. The recent professional literature on the subject has explored the ways in which notification is delivered without sufficiently considering the psychological incentives and barriers that may affect managers in transmitting risk information. The present study aimed at examining managers' personal determinants and notification of work hazards in a sample of 106 managers and 460 workers in 40 departments of three industrial plants in Israel. Results of our study showed that both managers and workers perceived the importance of the delivery of safety information as quite high (means of 3.43 and 3.7, respectively, out of 5), with managers reporting that they rely primarily on personal modes of communication. Immediate supervisors were regarded by both groups as the most important persons in notification. Managers having past experience in treating injured workers notified more, primarily using personal notification. The most important personal determinants that positively predicted managers' notification were their sense of self-efficacy and positive expectation of notification. Outcome denial and coping by distancing were negatively correlated with notifying about these risks.

  14. Impact of sex: determination of alcohol neuroadaptation and reinforcement.

    Science.gov (United States)

    Wiren, Kristine M; Hashimoto, Joel G; Alele, Paul E; Devaud, Leslie L; Price, Kimber L; Middaugh, Lawrence D; Grant, Kathleen A; Finn, Deborah A

    2006-02-01

    This article represents the proceedings of a symposium at the Research Society on Alcoholism meeting in Santa Barbara, California. The organizers/chairs were Kristine M. Wiren and Deborah A. Finn. Following a brief introduction by Deborah Finn, the presentations were (1) The Importance of Gender in Determining Expression Differences in Mouse Lines Selected for Chronic Ethanol Withdrawal Severity, by Kristine M. Wiren and Joel G. Hashimoto; (2) Sex Differences in Ethanol Withdrawal Involve GABAergic and Stress Systems, by Paul E. Alele and Leslie L. Devaud; (3) The Influence of Sex on Ethanol Consumption and Reward in C57BL/6 Mice, by Kimber L. Price and Lawrence D. Middaugh; and (4) Sex Differences in Alcohol Self-administration in Cynomolgus Monkeys, by Kathleen A. Grant.

  15. Use of yeast cell wall extract as a tool to reduce the impact of necrotic enteritis in broilers.

    Science.gov (United States)

    M'Sadeq, Shawkat A; Wu, Shu-Biao; Choct, Mingan; Forder, Rebecca; Swick, Robert A

    2015-05-01

    The use of a yeast cell wall extract derived from Saccharomyces cerevisiae (Actigen(®)) has been proposed as an alternative to in-feed antibiotics. This experiment was conducted to investigate the efficacy of yeast cell extract as an alternative to zinc bacitracin or salinomycin using a necrotic enteritis challenge model. A feeding study was conducted using 480-day-old male Ross 308 chicks assigned to 48 floor pens. A 2 × 4 factorial arrangement of treatments was employed. The factors were: challenge (- or +) and feed additive (control, zinc bacitracin at 100/50 mg/kg, yeast cell wall extract at 400/800/200 mg/kg, or salinomycin at 60 mg/kg in starter, grower, and finisher, respectively). Diets based on wheat, sorghum, soybean meal, meat and bone meal, and canola meal were formulated according to the Ross 308 nutrient specifications. Birds were challenged using a previously established protocol (attenuated Eimeria spp oocysts) on d 9 and 10(8) to 10(9) Clostridium perfringens (type A strain EHE-NE18) on d 14 and 15). Challenged and unchallenged birds were partitioned to avoid cross contamination. Challenged birds had lower weight gain, feed intake and livability compared to unchallenged birds on d 24 and d 35 (P enteritis lesion scores in the small intestine sections when compared to unchallenged birds (P enteritis in the current study. This study indicates that yeast cell wall extract has promise as a tool for controlling necrotic enteritis.

  16. Altering carbon allocation in hybrid poplar (Populus alba × grandidentata) impacts cell wall growth and development.

    Science.gov (United States)

    Unda, Faride; Kim, Hoon; Hefer, Charles; Ralph, John; Mansfield, Shawn D

    2016-12-20

    Galactinol synthase is a pivotal enzyme involved in the synthesis of the raffinose family of oligosaccharides (RFOs) that function as transport carbohydrates in the phloem, as storage compounds in sink tissues and as soluble metabolites that combat both abiotic and biotic stress in several plant species. Hybrid poplar (Populus alba × grandidentata) overexpressing the Arabidopsis thaliana GolS3 (AtGolS3) gene showed clear effects on development; the extreme overexpressing lines were stunted and had cell wall traits characteristic of tension wood, whereas lines with only moderate up-regulation grew normally and had moderately altered secondary cell wall composition and ultrastructure. Stem cross-sections of the developing xylem revealed a significant increase in the number of vessels, as well as the clear presence of a G-layer in the fibres. Furthermore, AtGolS3-OE lines possessed higher cellulose and lower lignin contents, an increase in cellulose crystallinity, and significantly altered hemicellulose-derived carbohydrates, notably manifested by their mannose and xylose contents. In addition, the transgenic plants displayed elevated xylem starch content. Transcriptome interrogation of the transgenic plants showed a significant up-regulation of genes involved in the synthesis of myo-inositol, along with genes involved in sucrose degradation. The results suggest that the overexpression of GolS and its product galactinol may serve as a molecular signal that initiates metabolic changes, culminating in a change in cell wall development and potentially the formation of tension wood.

  17. Magnetic single-walled carbon nanotubes-dispersive solid-phase extraction method combined with liquid chromatography-tandem mass spectrometry for the determination of paraquat in urine.

    Science.gov (United States)

    Ruan, Xiao-Lin; Qiu, Jing-Jing; Wu, Chuan; Huang, Tao; Meng, Rui-Bo; Lai, Yong-Qiang

    2014-08-15

    In this study, magnetic single-walled carbon nanotubes (MSWCNTs) were prepared by impregnating magnetic Fe3O4 nanoparticles onto the surfaces of carboxylic single-walled carbon nanotubes based on electrostatic interactions. The prepared MSWCNTs were used as the adsorbent for the dispersive solid-phase extraction (DSPE) of paraquat from human urine. After adsorption, the paraquat was quantitatively desorbed with 5%TFA in acetonitrile and determined by HPLC-MS. Extraction parameters such as the type of CNT adsorbent, extraction time, sample volume, wash solvent, and the type and volume of desorption solvent were optimized to obtain high DSPE recoveries and extraction efficiencies. Under the optimized conditions, the calibration curve was linear in the range 3.75-375.0 μg/L with a correlation coefficient of 0.999 45. The LOD (S/N=3) and LOQ (S/N=10) were 0.94 and 2.82 μg/L, respectively. The recoveries ranged from 92.89 to 108.9% for spiked real urine samples with RSDs below 3.21%. Finally, the new method was successfully used to determine paraquat in urine samples of suspected paraquat poisoning patients. The MSWCNTs exhibited suitable properties and a high adsorption capacity for the extraction of paraquat.

  18. Gold nanoparticle/multi-walled carbon nanotube modified glassy carbon electrode as a sensitive voltammetric sensor for the determination of diclofenac sodium.

    Science.gov (United States)

    Afkhami, Abbas; Bahiraei, Atousa; Madrakian, Tayyebeh

    2016-02-01

    A simple and highly sensitive sensor for the determination of diclofenac sodium based on gold nanoparticle/multi-walled carbon nanotube modified glassy carbon electrode is reported. Scanning electron microscopy along with energy dispersive X-ray spectroscopy, electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry was used to characterize the nanostructure and performance of the sensor and the results were compared with those obtained at the multi-walled carbon nanotube modified glassy carbon electrode and bare glassy carbon electrode. Under the optimized experimental conditions diclofenac sodium gave linear response over the range of 0.03-200μmolL(-1). The lower detection limits were found to be 0.02μmolL(-1). The effect of common interferences on the current response of DS was investigated. The practical application of the modified electrode was demonstrated by measuring the concentration of diclofenac sodium in urine and pharmaceutical samples. This revealed that the gold nanoparticle/multiwalled carbon nanotube modified glassy carbon electrode shows excellent analytical performance for the determination of diclofenac sodium in terms of a very low detection limit, high sensitivity, very good accuracy, repeatability and reproducibility.

  19. Complexity and determining dangerous levels of climate impacts

    Science.gov (United States)

    Huntingford, Chris

    2014-01-01

    A recent paper (Garten et al 2013 Environ. Res. Lett. 8 034032) finds very different global warming thresholds of concern between water scarcity and ecosystem changes. This may at first appear surprising, as each process is controlled to some extent by functioning of the land surface. Hence this analysis reflects the fundamentally different character of what constitutes water scarcity among people, compared to water stress for ecosystems. Garten et al (2013 Environ. Res. Lett. 8 034032) find both responses to warming are highly nonlinear, but in opposite senses. Water scarcity could affect multiple millions of people for even low levels of warming, but that number would almost stabilise should warming continue. In contrast, ecosystem changes become massively more responsive to climate change at higher warming levels. This re-iterates how complex the Earth system is, making it difficult to determine what constitutes overall single thresholds of climate change society may choose to consider avoiding. However, it is argued here that such targets are still much needed, providing a focal point for discussion, and complexity should not be used as an excuse to prevent setting them.

  20. Tests for determining impact resistance and strength of glass used for nuclear waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Bunnell, L.R.

    1979-05-01

    Tests are described for determining the impact resistance (Section A) and static tensile strength (Section B) of glasses containing simulated or actual nuclear wastes. This report describes the development and use of these tests to rank different glasses, to assess effects of devitrification, and to examine the effect of impact energy on resulting surface area. For clarity this report is divided into two sections, Impact Resistance and Tensile Strength.

  1. Analysis of a Large Rock Slope Failure on the East Wall of the LAB Chrysotile Mine in Canada: Back Analysis, Impact of Water Infilling and Mining Activity

    Science.gov (United States)

    Grenon, Martin; Caudal, Philippe; Amoushahi, Sina; Turmel, Dominique; Locat, Jacques

    2017-02-01

    A major mining slope failure occurred in July 2012 on the East wall of the LAB Chrysotile mine in Canada. The major consequence of this failure was the loss of the local highway (Road 112), the main commercial link between the region and the Northeast USA. LiDAR scanning and subsequent analyses were performed and enabled quantifying the geometry and kinematics of the failure area. Using this information, this paper presents the back analysis of the July 2012 failure. The analyses are performed using deterministic and probabilistic limit equilibrium analysis and finite-element shear strength reduction analysis modelling. The impact of pit water infilling on the slope stability is investigated. The impact of the mining activity in 2011 in the lower part of the slope is also investigated through a parametric analysis.

  2. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Mantha, Pallavi [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  3. Determinants of health policy impact: comparative results of a European policymaker study.

    NARCIS (Netherlands)

    Rütten, A.; Lüschen, G.; Lengerke, T. von; Abel, T.; Kannas, L.; Rodríguez Diaz, J.A.; Vinck, J.; Zee, J. van der

    2003-01-01

    OBJECTIVES: This article will use a new theoretical framework for the analysis of health policy impact introduced by Rutten et al. (2003). In particular, it will report on a comparative European study of policymakers' perception and evaluation of specific determinants of the policy impact, both in

  4. Whaling on Walling: A Uniform Approach to Determining Whether Interns Are "Employees" Under the Fair Labor Standards Act

    National Research Council Canada - National Science Library

    Cody Elyse Brookhouser

    2015-01-01

      This Note argues that, of the tests currently used by circuit courts to determine who constitutes an "employee" under the Fair Labor Standards Act, the Supreme Court should clarify that the totality...

  5. Gold nanoparticle/multi-walled carbon nanotube modified glassy carbon electrode as a sensitive voltammetric sensor for the determination of diclofenac sodium

    Energy Technology Data Exchange (ETDEWEB)

    Afkhami, Abbas, E-mail: afkhami@basu.ac.ir; Bahiraei, Atousa; Madrakian, Tayyebeh

    2016-02-01

    A simple and highly sensitive sensor for the determination of diclofenac sodium based on gold nanoparticle/multi-walled carbon nanotube modified glassy carbon electrode is reported. Scanning electron microscopy along with energy dispersive X-ray spectroscopy, electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry was used to characterize the nanostructure and performance of the sensor and the results were compared with those obtained at the multi-walled carbon nanotube modified glassy carbon electrode and bare glassy carbon electrode. Under the optimized experimental conditions diclofenac sodium gave linear response over the range of 0.03–200 μmol L{sup −1}. The lower detection limits were found to be 0.02 μmol L{sup −1}. The effect of common interferences on the current response of DS was investigated. The practical application of the modified electrode was demonstrated by measuring the concentration of diclofenac sodium in urine and pharmaceutical samples. This revealed that the gold nanoparticle/multiwalled carbon nanotube modified glassy carbon electrode shows excellent analytical performance for the determination of diclofenac sodium in terms of a very low detection limit, high sensitivity, very good accuracy, repeatability and reproducibility. - Highlights: • GCE was modified with multiwalled carbon nanotube and gold nanoparticles. • AuNP/MWCNT/GCE was used for the determination of diclofenac sodium. • Modified electrode was characterized by SEM, EDS and EIS. • The proposed method showed excellent analytical figures of merit. • This sensor was used for the determination of diclofenac sodium in real samples.

  6. Impact of social determinants of health on outcomes for type 2 diabetes: a systematic review.

    Science.gov (United States)

    Walker, Rebekah J; Smalls, Brittany L; Campbell, Jennifer A; Strom Williams, Joni L; Egede, Leonard E

    2014-09-01

    Social determinants of health include the social and economic conditions that influence health status. Research into the impact of social determinants on individuals with type 2 diabetes has largely focused on the prevention of or risk of developing diabetes. No review exists summarizing the impact of social determinants of health outcomes in patients with type 2 diabetes. This systematic review examined whether social determinants of health have an impact on health outcomes in type 2 diabetes. Medline was searched for articles that (a) were published in English (b) targeted adults, ages 18 + years, (c) had a study population which was diagnosed with type 2 diabetes, (d) the study was done in the United States, and (e) the study measured at least one of the outcome measures-glycemic control, cholesterol (LDL), blood pressure, quality of life or cost. Using a reproducible strategy, 2,110 articles were identified, and 61 were reviewed based on inclusion criteria. Twelve were categorized as Economic Stability and Education, 17 were categorized as Social and Community Context, 28 were categorized as Health and Health Care, and three were categorized as Neighborhood and Built Environment. Based on the studies reviewed, social determinants have an impact on glycemic control, LDL, and blood pressure to varying degrees. The impact on cost and quality of life was not often measured, but when quality of life was investigated, it did show significance. More research is needed to better characterize the direct impact of social determinants of health on health outcomes in diabetes.

  7. Impact of scaffold micro and macro architecture on Schwann cell proliferation under dynamic conditions in a rotating wall vessel bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Valmikinathan, Chandra M.; Hoffman, John [Department of Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, 07030 (United States); Yu, Xiaojun, E-mail: xyu@stevens.edu [Department of Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, 07030 (United States)

    2011-01-01

    Over the last decade tissue engineering has emerged as a powerful alternative to regenerate lost tissues owing to trauma or tumor. Evidence shows that Schwann cell containing scaffolds have improved performance in vivo as compared to scaffolds that depend on cellularization post implantation. However, owing to limited supply of cells from the patients themselves, several approaches have been taken to enhance cell proliferation rates to produce complete and uniform cellularization of scaffolds. The most common approach is the application of a bioreactor to enhance cell proliferation rate and therefore reduce the time needed to obtain sufficiently significant number of glial cells, prior to implantation. In this study, we show the application of a rotating wall bioreactor system for studying Schwann cell proliferation on nanofibrous spiral shaped scaffolds, prepared by solvent casting and salt leaching techniques. The scaffolds were fabricated from polycaprolactone (PCL), which has ideal mechanical properties and upon degradation does not produce acidic byproducts. The spiral scaffolds were coated with aligned or random nanofibers, produced by electrospinning, to provide a substrate that mimics the native extracellular matrix and the essential contact guidance cues. At the 4 day time point, an enhanced rate of cell proliferation was observed on the open structured nanofibrous spiral scaffolds in a rotating wall bioreactor, as compared to static culture conditions. However, the cell proliferation rate on the other contemporary scaffolds architectures such as the tubular and cylindrical scaffolds show reduced cell proliferation in the bioreactor as compared to static conditions, at the same time point. Moreover, the rotating wall bioreactor does not alter the orientation or the phenotype of the Schwann cells on the aligned nanofiber containing scaffolds, wherein, the cells remain aligned along the length of the scaffolds. Therefore, these open structured spiral

  8. Clinical impact of ' in-treatment' wall motion abnormalities in hypertensive patients with left ventricular hypertrophy: the LIFE study

    DEFF Research Database (Denmark)

    Cicala, S.; Simone, G. de; Wachtell, K.;

    2008-01-01

    to analyze the primary composite endpoint of cardiovascular death, MI, or stroke and, separately, for fatal and nonfatal MI and hospitalized heart failure. Results During a mean follow-up of 4.8 years, an event was recorded in 67 ( 9%) patients. In Cox models after adjusting for age, gender, treatment, blood......, however, never been investigated. We examined whether 'in- treatment' wall motion abnormalities predicted outcome in the Losartan Intervention For Endpoint ( LIFE) reduction in hypertension echocardiographic substudy. Methods We studied 749 patients without coronary artery disease, myocardial infarction...

  9. The impact of exercise training on conduit artery wall thickness and remodeling in chronic heart failure patients

    NARCIS (Netherlands)

    Maiorana, A.J.; Naylor, L.H.; Exterkate, A.; Swart, A.; Thijssen, D.H.J.; Lam, K.; O'Driscoll, G.; Green, D.J.

    2011-01-01

    Exercise training is an important adjunct to medical therapy in chronic heart failure, but the extent to which exercise impacts on conduit artery remodeling is unknown. The aim of this study was to evaluate the impact of aerobic and resistance exercise training modalities on arterial remodeling in

  10. Problems of Determining Size and Character of Wind Turbines’ Visual Impact Zones on Lithuanian Landscape

    OpenAIRE

    Jonas Abromas; Jūratė Kamičaitytė-Virbašienė

    2013-01-01

    landscape variety, time of the day, and other factors (Tsoutsos et al., 2009). In this paper the factors that influence the wind turbine’s visibility are analyzed. One of the most important aspects determining wind turbine’s visual impact is observation distance. The visual impact zones of wind turbines in different countries having been analyzed and the situation in Lithuania taken in, the Table of wind turbine’s visual impact hypothetical degrees is set up. To determine the precision of vis...

  11. Determination of the impact of glycolate on ARP and MCU operations

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K. M.L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fondeur, F. F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shehee, T. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, A. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-05-17

    Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal, phase separation, or coalescer performance at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU).

  12. The impact of lithium wall coatings on NSTX discharges and the engineering of the Lithium Tokamak eXperiment (LTX)

    Energy Technology Data Exchange (ETDEWEB)

    Majeski, R. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Avasarala, S. [Princeton Plasma Physics Laboratory (PPPL); Bell, M. G. [Princeton Plasma Physics Laboratory (PPPL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Berzak, L. [Princeton Plasma Physics Laboratory (PPPL); Beiersdorfer, P. [Lawrence Livermore National Laboratory (LLNL); Gerhardt, S. P. [Princeton Plasma Physics Laboratory (PPPL); Gransted, E. [Princeton Plasma Physics Laboratory (PPPL); Gray, T. [Princeton Plasma Physics Laboratory (PPPL); Jacobson, C. [Princeton Plasma Physics Laboratory (PPPL); Kallman, J. [Princeton Plasma Physics Laboratory (PPPL); Kaye, S. [Princeton Plasma Physics Laboratory (PPPL); Kozub, T. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Lepson, J. [Lawrence Livermore National Laboratory (LLNL); Lundberg, D. P. [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Mansfield, D. [Princeton Plasma Physics Laboratory (PPPL); Paul, S. F. [Princeton Plasma Physics Laboratory (PPPL); Pereverzev, G. V. [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, Garching, Germany; Schneider, H. [Princeton Plasma Physics Laboratory (PPPL); Soukhanovskii, V. [Lawrence Livermore National Laboratory (LLNL); Strickler, T. [Princeton Plasma Physics Laboratory (PPPL); Stotler, D. [Princeton Plasma Physics Laboratory (PPPL); Timberlake, J. [Princeton Plasma Physics Laboratory (PPPL); Zakharov, L. E. [Princeton Plasma Physics Laboratory (PPPL)

    2010-01-01

    Recent experiments on the National Spherical Torus eXperiment (NSTX) have shown the benefits of solid lithium coatings on carbon PFC's to diverted plasma performance, in both L- and H-mode confinement regimes. Better particle control, with decreased inductive flux consumption, and increased electron temperature, ion temperature, energy confinement time, and DD neutron rate were observed. Successive increases in lithium coverage resulted in the complete suppression of ELM activity in H-mode discharges. A liquid lithium divertor (LLD), which will employ the porous molybdenum surface developed for the LTX shell, is being installed on NSTX for the 2010 run period, and will provide comparisons between liquid walls in the Lithium Tokamak eXperiment (LTX) and liquid divertor targets in NSTX. LTX, which recently began operations at the Princeton Plasma Physics Laboratory, is the world's first confinement experiment with full liquid metal plasma-facing components (PFCs). All materials and construction techniques in LTX are compatible with liquid lithium. LTX employs an inner, heated, stainless steel-faced liner or shell, which will be lithium-coated. In order to ensure that lithium adheres to the shell, it is designed to operate at up to 500-600 degrees C to promote wetting of the stainless by the lithium, providing the first hot wall in a tokamak to Operate at reactor-relevant temperatures. The engineering of LTX will be discussed. (c) 2010 Elsevier B.V. All rights reserved.

  13. Comparison of sample digestion techniques for the determination of trace and residual catalyst metal content in single-wall carbon nanotubes by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grinberg, Patricia, E-mail: patricia.grinberg@nrc.ca [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Sturgeon, Ralph E. [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Diehl, Liange de O.; Bizzi, Cezar A. [Measurement Science and Standards, National Research Council Canada, Ottawa (Canada); Chemistry Department, Universidade Federal de Santa Maria, Santa Maria (Brazil); Flores, Erico M.M. [Chemistry Department, Universidade Federal de Santa Maria, Santa Maria (Brazil)

    2015-03-01

    A single-wall carbon nanotube material produced by laser ablation of renewable biochar in the presence of Ni and Co catalyst was characterized for residual catalyst (Co and Ni) as well as trace metal impurity content (Fe, Mo, Cr, Pb and Hg) by isotope dilution ICP-MS following sample digestion. Several matrix destruction procedures were evaluated, including a multi-step microwave-assisted acid digestion, dry ashing at 450 °C and microwave-induced combustion with oxygen. Results were benchmarked against those derived from neutron activation analysis and also supported by solid sampling continuum source GF-AAS for several of the elements. Although laborious to execute, the multi-step microwave-assisted acid digestion proved to be most reliable for recovery of the majority of the analytes, although content of Cr remained biased low for each approach, likely due to its presence as refractory carbide. - Highlights: • Determination of trace and residual catalyst metal content in Single-Wall Carbon Nanotubes by Inductively Coupled Plasma Mass Spectrometry. • Comparative study of digestion methodology combined with high precision isotope dilution ICP-MS for quantitation of elements of toxicologic relevance. • Results were benchmarked against those derived from neutron activation analysis and also supported by solid sampling continuum source GF-AAS for several of the elements.

  14. Simultaneous determination of phenolic compounds in sesame oil using LC-MS/MS combined with magnetic carboxylated multi-walled carbon nanotubes.

    Science.gov (United States)

    Wu, Rao; Ma, Fei; Zhang, Liangxiao; Li, Peiwu; Li, Guangming; Zhang, Qi; Zhang, Wen; Wang, Xiuping

    2016-08-01

    A novel magnetic carboxylated multi-walled carbon nanotubes (c-MWCNT-MNPs) was proposed for magnetic solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry to determine phenolic compounds in sesame oil. In this study, c-MWCNT-MNPs were acquired by simply dispersing Fe3O4 magnetic nanoparticles into carboxylated multi-walled carbon nanotubes. The major parameters affecting extraction efficiency were optimized, including the type and volume of desorption solvents, extraction and desorption time, washing solution, and sorbent amount. The limit of quantifications and limit of detections were from 0.03μg/kg to 43.00μg/kg and from 0.01μg/kg to 13.60μg/kg, respectively. The recoveries of phenolic compounds in vegetable oils were in the range of 83.8-125.9% with inter-day and intra-day precisions of less than 13.2%. It was confirmed that this method was simple, rapid and reliable with an excellent potential for routine analysis of phenolic compounds in oil samples.

  15. Impact of flow rates in a cardiac cycle on correlations between advanced human carotid plaque progression and mechanical flow shear stress and plaque wall stress

    Directory of Open Access Journals (Sweden)

    Ferguson Marina

    2011-07-01

    Full Text Available Abstract Background Mechanical stresses are known to play important roles in atherosclerotic plaque initiation, progression and rupture. It has been well-accepted that atherosclerosis initiation and early progression correlate negatively with flow wall shear stresses (FSS. However, mechanisms governing advanced plaque progression are not well understood. Method In vivo serial MRI data (patient follow-up were acquired from 14 patients after informed consent. Each patient had 2-4 scans (scan interval: 18 months. Thirty-two scan pairs (baseline and follow-up scans were formed with slices matched for model construction and analysis. Each scan pair had 4-10 matched slices which gave 400-1000 data points for analysis (100 points per slice on lumen. Point-wise plaque progression was defined as the wall thickness increase (WTI at each data point. 3D computational models with fluid-structure interactions were constructed based on in vivo serial MRI data to extract flow shear stress and plaque wall stress (PWS on all data points to quantify correlations between plaque progression and mechanical stresses (FSS and PWS. FSS and PWS data corresponding to both maximum and minimum flow rates in a cardiac cycle were used to investigate the impact of flow rates on those correlations. Results Using follow-up scans and maximum flow rates, 19 out of 32 scan pairs showed a significant positive correlation between WTI and FSS (positive/negative/no significance correlation ratio = 19/9/4, and 26 out of 32 scan pairs showed a significant negative correlation between WTI and PWS (correlation ratio = 2/26/4. Corresponding to minimum flow rates, the correlation ratio for WTI vs. FSS and WTI vs. PWS were (20/7/5 and (2/26/4, respectively. Using baseline scans, the correlation ratios for WTI vs. FSS were (10/12/10 and (9/13/10 for maximum and minimum flow rates, respectively. The correlation ratios for WTI vs. PWS were the same (18/5/9, corresponding to maximum and minimum

  16. Impact of flow rates in a cardiac cycle on correlations between advanced human carotid plaque progression and mechanical flow shear stress and plaque wall stress.

    Science.gov (United States)

    Yang, Chun; Canton, Gador; Yuan, Chun; Ferguson, Marina; Hatsukami, Thomas S; Tang, Dalin

    2011-07-19

    Mechanical stresses are known to play important roles in atherosclerotic plaque initiation, progression and rupture. It has been well-accepted that atherosclerosis initiation and early progression correlate negatively with flow wall shear stresses (FSS). However, mechanisms governing advanced plaque progression are not well understood. In vivo serial MRI data (patient follow-up) were acquired from 14 patients after informed consent. Each patient had 2-4 scans (scan interval: 18 months). Thirty-two scan pairs (baseline and follow-up scans) were formed with slices matched for model construction and analysis. Each scan pair had 4-10 matched slices which gave 400-1000 data points for analysis (100 points per slice on lumen). Point-wise plaque progression was defined as the wall thickness increase (WTI) at each data point. 3D computational models with fluid-structure interactions were constructed based on in vivo serial MRI data to extract flow shear stress and plaque wall stress (PWS) on all data points to quantify correlations between plaque progression and mechanical stresses (FSS and PWS). FSS and PWS data corresponding to both maximum and minimum flow rates in a cardiac cycle were used to investigate the impact of flow rates on those correlations. Using follow-up scans and maximum flow rates, 19 out of 32 scan pairs showed a significant positive correlation between WTI and FSS (positive/negative/no significance correlation ratio = 19/9/4), and 26 out of 32 scan pairs showed a significant negative correlation between WTI and PWS (correlation ratio = 2/26/4). Corresponding to minimum flow rates, the correlation ratio for WTI vs. FSS and WTI vs. PWS were (20/7/5) and (2/26/4), respectively. Using baseline scans, the correlation ratios for WTI vs. FSS were (10/12/10) and (9/13/10) for maximum and minimum flow rates, respectively. The correlation ratios for WTI vs. PWS were the same (18/5/9), corresponding to maximum and minimum flow rates. Flow shear stress

  17. Wonderful Walls

    Science.gov (United States)

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  18. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    The introduction of Light Emitting Diodes (LEDs) in the built environment has encouraged myriad applications, often embedded in surfaces as an integrated part of the architecture. Thus the wall as responsive luminous skin is becoming, if not common, at least familiar. Taking into account how wall...

  19. Determination of Dopamine in the Presence of Ascorbic Acid by Nafion and Single-Walled Carbon Nanotube Film Modified on Carbon Fiber Microelectrode

    Directory of Open Access Journals (Sweden)

    Haesang Jeong

    2008-11-01

    Full Text Available Carbon fiber microelectrode (CFME modified by Nafion and single-walled carbon nanotubes (SWNTs was studied by voltammetric methods in phosphate buffer saline (PBS solution at pH 7.4. The Nafion-SWNTs/CFME modified microelectrode exhibited strongly enhanced voltammetric sensitivity and selectivity towards dopamine (DA determination in the presence of ascorbic acid (AA. Nafion-SWNTs film accelerated the electron transfer reaction of DA, but Nafion film as a negatively charged polymer restrained the electrochemical response of AA. Voltammetric techniques separated the anodic peaks of DA and AA, and the interference from AA was effectively excluded from DA determination. Linear calibration plots were obtained in the DA concentration range of 10 nM - 10 μM and the detection limit of the anodic current was determined to be 5 nM at a signal-to-noise ratio of 3. The study results demonstrate that DA can be determined without any interference from AA at the modified microelectrode, thereby increasing the sensitivity, selectivity, and reproducibility and stability.

  20. Determination of tryptophan and kynurenine in human plasma by liquid chromatography-electrochemical detection with multi-wall carbon nanotube-modified glassy carbon electrode.

    Science.gov (United States)

    Liu, Lihong; Chen, Ying; Zhang, Yulin; Wang, Fang; Chen, Zilin

    2011-08-01

    A novel method was developed for the simultaneous determination of kynurenine and tryptophan by high-performance liquid chromatography with electrochemical detection at multi-wall carbon nanotube (MWCNT)-modified glassy carbon electrode. The separation and detection conditions were optimized. The typical HPLC experiments were conducted by using a reversed-phase ODS column with a mobile phase consisting of stock acetate buffer (pH 5)-methanol (4:1, v/v) using an isocratic elution at the flow rate of 1.0 mL/min. The obtained LODs for kynurenine and tryptophane were 0.5 and 0.4 µmol/L, respectively. The analytical method for human plasma samples was validated and confirmed by LC-UV and LC-MS. The recoveries were in the range of 84.8-110%, and the precision was lower than 5.9%. Copyright © 2010 John Wiley & Sons, Ltd.

  1. Determination of 6-Mercaptopurine in Rat Blood by Microdialysis Coupled with High Performance Liquid Chromatography on a Functionalized Multi-wall Carbon Nanotubes Modified Electrode

    Institute of Scientific and Technical Information of China (English)

    LIN Li; QIU Pei-hong; XIE Xia-feng; CAO Xu-ni; JIN Li-tong

    2005-01-01

    A new chemically modified electrode(CME) immobilized on the surface of multi-wall carbon nanotubes functionalized with carboxylic groups was fabricated. The results indicate that the CME exhibits efficiently electrocatalytic oxidation of 6-mercaptopurine(6-MP). The CME can be used as the working electrode in the liquid chromatography for the determination of 6-MP. The peak current of 6-MP is linearly changed with its concentration ranging from 4.0×10-7 to 1.0×10-4 mol/L with the calculated detection limit (S/N= 3) of 2.0×10-7 mol/L. Coupled with microdialysis sampling, the method has been successfully applied to assessing the content of 6-MP in rat blood.

  2. Natural Gas and Cellulosic Biomass: A Clean Fuel Combination? Determining the Natural Gas Blending Wall in Biofuel Production.

    Science.gov (United States)

    M Wright, Mark; Seifkar, Navid; Green, William H; Román-Leshkov, Yuriy

    2015-07-07

    Natural gas has the potential to increase the biofuel production output by combining gas- and biomass-to-liquids (GBTL) processes followed by naphtha and diesel fuel synthesis via Fischer-Tropsch (FT). This study reflects on the use of commercial-ready configurations of GBTL technologies and the environmental impact of enhancing biofuels with natural gas. The autothermal and steam-methane reforming processes for natural gas conversion and the gasification of biomass for FT fuel synthesis are modeled to estimate system well-to-wheel emissions and compare them to limits established by U.S. renewable fuel mandates. We show that natural gas can enhance FT biofuel production by reducing the need for water-gas shift (WGS) of biomass-derived syngas to achieve appropriate H2/CO ratios. Specifically, fuel yields are increased from less than 60 gallons per ton to over 100 gallons per ton with increasing natural gas input. However, GBTL facilities would need to limit natural gas use to less than 19.1% on a LHV energy basis (7.83 wt %) to avoid exceeding the emissions limits established by the Renewable Fuels Standard (RFS2) for clean, advanced biofuels. This effectively constitutes a blending limit that constrains the use of natural gas for enhancing the biomass-to-liquids (BTL) process.

  3. Determine an effective golf swing by swing speed and impact precision tests

    Institute of Scientific and Technical Information of China (English)

    Jiann-Jyh Wang; Pei-Feng Yang; Wei-Hua Ho; Tzyy-Yuang Shiang

    2015-01-01

    Background:To understand an effective golf swing, both swing speed and impact precision must be thoroughly and simultaneously examined. The aim of this study was to perform both swing speed test and impact precision test to ascertain what swing type determines an effective impact. Methods:Seven golfers from a college team (handicap:0-12) were recruited to complete a swing speed test and impact precision test using a 5-iron club. A force plate and electromyography (EMG) system were used to collect data in the swing speed test to compare the difference between two motion sequences. High speed video cameras were used to determine the displacement of rotation center for impact precision test. Results: The results showed a significant difference ( p < 0.01) in clubhead speed with different motion sequences and muscle contraction patterns. In the impact precision test, the displacement of the rotation center which defined as the inner center point of the C7 was significantly different ( p<0.05) between different ball impacted marks on club face. Conclusion:The vertical peak ground reaction force on left foot occurring before impact and the left latissimus dorsi contracting prior to the right pectoralis major represent a superior skill by allowing the club to strike the ball with normal collision at a faster speed.

  4. The impact of chimerism in DNA-based forensic sex determination analysis.

    Science.gov (United States)

    George, Renjith; Donald, Preethy Mary; Nagraj, Sumanth Kumbargere; Idiculla, Jose Joy; Hj Ismail, Rashid

    2013-01-01

    Sex determination is the most important step in personal identification in forensic investigations. DNA-based sex determination analysis is comparatively more reliable than the other conventional methods of sex determination analysis. Advanced technology like real-time polymerase chain reaction (PCR) offers accurate and reproducible results and is at the level of legal acceptance. But still there are situations like chimerism where an individual possess both male and female specific factors together in their body. Sex determination analysis in such cases can give erroneous results. This paper discusses the phenomenon of chimerism and its impact on sex determination analysis in forensic investigations.

  5. Determination of n-alkanes contamination in soil samples by micro gas chromatography functionalized by multi-walled carbon nanotubes.

    Science.gov (United States)

    Li, Yubo; Zhang, Runzhou; Wang, Tao; Wang, Yonghuan; Xu, Tianbai; Li, Lingfeng; Zhao, Weijun; Dong, Shurong; Wang, Xiaozhi; Luo, Jikui

    2016-09-01

    A new method for separation of 11 n-alkanes: octane, o-nonane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentdecne, n-hexadecath, heptadecane, n-octadecane in soil samples was developed. Kuderna-Danish (K.D.) concentrator enrichment prior to ultrasonic extraction and the silicone chromatography column purification and with gas chromatography flame ionization detection (GC-FID) could be used for n-alkanes determination. The micro channels of open tubular column were fabricated onto a silicon wafer to replace the quartz capillary chromatographic column. The column structure and analysis parameters that affected the column separation were investigated and optimized. Under optimal conditions, the extract reagent was centrifuged and collected. A silicone chromatography column and a K.D. concentrator were used for further clean-up and enrichment. Using this method, the limits of detection (LOD) and limits of quantification (LOQ) were obtained in the range of 0.03-0.15 and 0.1-0.5 mg kg(-1) in soil samples, respectively. The relative standard deviation (RSD) was under 12%. The optimized procedure that presented good analytical performance (with recoveries ranging from 56.5% to 89.2%), was successfully applied to determine n-alkane content in farmland soil samples adjacent to a highway. The results showed that the MWCNTs-functionalized column is capable of separating the alkane contaminations with high resolution in about 3 min, which is much shorter than that of GC-MS and other conventional analytical methods, demonstrating its great potential for rapid analysis.

  6. Hyper-velocity impact test and simulation of a double-wall shield concept for the Wide Field Monitor aboard LOFT

    CERN Document Server

    Perinati, E; Santangelo, A; Suchy, S; Tenzer, C; Del Monte, E; Herder, J -W den; Diebold, S; Feroci, M; Rachevski, A; Vacchi, A; Zampa, G; Zampa, N

    2014-01-01

    The space mission LOFT (Large Observatory For X-ray Timing) was selected in 2011 by ESA as one of the candidates for the M3 launch opportunity. LOFT is equipped with two instruments, the Large Area Detector (LAD) and the Wide Field Monitor (WFM), based on Silicon Drift Detectors (SDDs). In orbit, they would be exposed to hyper-velocity impacts by environmental dust particles, which might alter the surface properties of the SDDs. In order to assess the risk posed by these events, we performed simulations in ESABASE2 and laboratory tests. Tests on SDD prototypes aimed at verifying to what extent the structural damages produced by impacts affect the SDD functionality have been performed at the Van de Graaff dust accelerator at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg. For the WFM, where we expect a rate of risky impacts notably higher than for the LAD, we designed, simulated and successfully tested at the plasma accelerator at the Technical University in Munich (TUM) a double-wall shield...

  7. Drop Weight Impact Behavior of Al-Si-Cu Alloy Foam-Filled Thin-Walled Steel Pipe Fabricated by Friction Stir Back Extrusion

    Science.gov (United States)

    Hangai, Yoshihiko; Nakano, Yukiko; Utsunomiya, Takao; Kuwazuru, Osamu; Yoshikawa, Nobuhiro

    2017-02-01

    In this study, Al-Si-Cu alloy ADC12 foam-filled thin-walled stainless steel pipes, which exhibit metal bonding between the ADC12 foam and steel pipe, were fabricated by friction stir back extrusion. Drop weight impact tests were conducted to investigate the deformation behavior and mechanical properties of the foam-filled pipes during dynamic compression tests, which were compared with the results of static compression tests. From x-ray computed tomography observation, it was confirmed that the fabricated foam-filled pipes had almost uniform porosity and pore size distributions. It was found that no scattering of the fragments of collapsed ADC12 foam occurred for the foam-filled pipes owing to the existence of the pipe surrounding the ADC12 foam. Preventing the scattering of the ADC12 foam decreases the drop in stress during dynamic compression tests and therefore improves the energy absorption properties of the foam.

  8. Single-Walled-Carbon-Nanotube-Modified Pyrolytic Graphite Electrode Used as a Simple Sensor for the Determination of Salbutamol in Urine

    Directory of Open Access Journals (Sweden)

    Rajendra N. Goyal

    2011-01-01

    Full Text Available A fast and sensitive voltammetric method has been proposed for the determination of salbutamol at single-walled-carbon-nanotube-modified edge-plane pyrolytic graphite electrode (SWNT/EPPGE in human urine. The electrochemical response of salbutamol was determined by square wave voltammetry (SWV in phosphate buffer solution (PBS at physiological pH 7.2. The modified electrode showed improved voltammetric response towards the oxidation of salbutamol, and a well-defined anodic peak was observed at ~600 mV with enhanced peak current in comparison to the bare electrode. Linear calibration plot using SWNT/EPPGE was obtained in the concentration range of 50 to 2500 ngml-1 with sensitivity and detection limit of 2.15 nA/ngml-1 and 4.31 ngml-1, respectively. The developed method has been successfully applied for the determination of salbutamol in commercial preparations and human body fluids. Fast analysis of salbutamol in human urine makes the proposed method of great interest for doping control purposes at the site of competitive games.

  9. Poly(pyrocatechol-3,5-disodiumsulfonate)/multi-walled carbon nanotubes composite for simultaneous determination of dopamine, ascorbic acid and uric acid.

    Science.gov (United States)

    Xue, Ying; Zhao, Hong; Wu, Zhijiao; Li, Xiangjun; He, Yujian; Yuan, Zhuobin

    2013-02-01

    A novel poly(pyrocatechol-3,5-disodiumsulfonate)/multi-walled carbon nanotubes (PPD/MWCNT) composite film modified glassy carbon electrode (GCE) was fabricated and successfully used to simultaneously determine ascorbic acid (AA), dopamine (DA) and uric acid (UA). Owing to the synergistic effects of PPD and MWCNTs, the electrochemical responses of AA, DA and UA at PPD/MWCNTs/GCE were clearly superior to those at bare GCE. Additionally, the PPD/MWCNTs composite film could reduce the potential overlap of AA, DA and UA so as to favor simultaneous determination of the three substances. Under the optimum conditions, the linear calibration curves of AA, DA and UA were obtained by differential pulse voltammetry in the range of 10-1000, 1-100 and 4-1200 microM, and the detection limits were 5, 0.5 and 0.5 microM (S/N = 3) respectively. The results showed PPD/MWCNTs/GCE possessed good reproducibility and stability, and it could be applied to determine UA in human urine with satisfying recovery by standard addition method.

  10. Determination of serotonin on a glassy carbon electrode modified by electropolymerization of meso-tetrakis(2-aminophenyl)porphyrin and single walled carbon nanotubes.

    Science.gov (United States)

    Kim, Seul Ki; Ahmed, Mohammad Shamsuddin; Jeong, Haesang; You, Jung-Min; Jeon, Seungwon

    2011-03-01

    A chemically modified electrode [poly(TAPP)-SWNT/GCE] was prepared by electropolymerization of meso-tetrakis(2-aminophenyl)porphyrin (TAPP)-single walled carbon nanotubes (SWNT) on the surface of a glassy carbon electrode (GCE). This modified electrode was employed as an electrochemical biosensor for the determination of serotonin concentration and exhibited a typical enhance effect on the current response of serotonin and lower oxidation overpotential. The biosensor was very effective to determined 5-HT in a mixture. The linear response was in the range 2.0 x 10(-7) to 1.0 x 10(-5) M, with a correlation coefficient of 0.999 [i(p)(microA) = 3.406 C (microM)+0.132] on the anodic current, with a detection limit of 1 x 10(-9) M. Due to the relatively low currents and different potentials in the electrochemical responses to ascorbic acid and dopamine, the modified electrode is a useful and effective sensing device for the selective and sensitive serotonin determination in the presence of ascorbic acid and dopamine.

  11. Cell Wall Biology: Perspectives from Cell Wall Imaging

    Institute of Scientific and Technical Information of China (English)

    Kieran J.D.Lee; Susan E.Marcus; J.Paul Knox

    2011-01-01

    Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth,are major repositories for photosynthetically accumulated carbon,and,in addition,impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose,hemicelluloses,and pectic polysaccharides. During the evolution of land plants,polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.

  12. Problems of Determining Size and Character of Wind Turbines’ Visual Impact Zones on Lithuanian Landscape

    Directory of Open Access Journals (Sweden)

    Jonas Abromas

    2013-01-01

    Full Text Available landscape variety, time of the day, and other factors (Tsoutsos et al., 2009. In this paper the factors that influence the wind turbine’s visibility are analyzed. One of the most important aspects determining wind turbine’s visual impact is observation distance. The visual impact zones of wind turbines in different countries having been analyzed and the situation in Lithuania taken in, the Table of wind turbine’s visual impact hypothetical degrees is set up. To determine the precision of visual impact degrees, the survey in situ is done and its results have been compared to the theoretical-hypothetical visual impact degrees (a comparative analysis. Visual impact zones of wind turbines are evaluated from ten pre-selected observation points. Six wind turbines (of 2 MW power each, installed in Kretinga district near village Vydmantai, are analyzed. At the end of the study, it is identified that the categorization of visual impact zones of wind turbines should be corrected in accordance with the visual character of Lithuanian landscape. Different observation distances have a great influence on the significance of a visual impact. Being 0-7 km from the wind farm (in this case the wind turbine’s visual impact on the landscape varies from dominants to subdominants, the intervals of observation distances have to be shorter. It is noticed that forests, buildings, and other vertical objects that are located near the observation point change the visual impact significance very much. Weather conditions make significant influence as well, especially on visibility of wind turbine wheels.DOI: http://dx.doi.org/10.5755/j01.erem.62.4.2363

  13. The impact of extraction with a chelating agent under acidic conditions on the cell wall polymers of mango peel.

    Science.gov (United States)

    Jamsazzadeh Kermani, Zahra; Shpigelman, Avi; Kyomugasho, Clare; Van Buggenhout, Sandy; Ramezani, Mohsen; Van Loey, Ann M; Hendrickx, Marc E

    2014-10-15

    The objective of this research was to evaluate whether mango peel is a potential source of functional cell wall polymers. To reach this objective, the native pectin polymers (NPP) extracted as alcohol insoluble residue from mango peel, were characterised in terms of uronic acid content, degree of methoxylation, neutral sugar content, and molar mass and compared to citric acid (pH 2.5, 2h at 80°C) extracted polymers, mimicking industrial pectin extraction conditions. Water-solubilised NPP were highly methoxylated having two populations with a Mw of 904 and 83kDa and a degree of methoxylation of 66%. Citric acid extraction with a yield higher than H2SO4 extraction resulted in a very branched pectin with an extremely high DM (83%) and a high molar mass. Comparing the Fourier Transform Infra-Red spectroscopy of extracted and native WSF showed that citric acid remained partially associated to the extracted pectin due to its chelating properties.

  14. Wall Turbulence.

    Science.gov (United States)

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  15. A new modification method of a Cetyl Trimethyl Ammonium Bromide/Nano-ZnO and Multi-walled Carbon Nanotubes Electrode for Determination of Anti Doping in Urine

    Science.gov (United States)

    Zhao, Zhiwei; Mu, Shuai; Zheng, Jie; Gu, Lingyan; Shen, Guijun; Shen, Yuan

    2017-07-01

    The preparation and application of Cetyl Trimethyl Ammonium Bromide/Nano-ZnO and Multi-walled Carbon Nanotubes (CTAB/ZnO-MWNTs) Modified Electrodes was studied, establishing a new electrochemical method for determination of carteolol hydrochloride in urine. After its pre-enrichment by adsorption and extraction on modified electrodes, electrochemical behaviors of carteolol hydrochloride on the modified electrodes were studied by CV and DPV. The response is linear at the range of 1×10-3 ∼ 2×10-1 g/L, with a detection limit of 2×10-4 g/L. Under appropriate conditions, the content of carteolol hydrochloride in urine can be determined directly by the method, which had strong anti-interference ability and the recovery is 96.5% - 110.5%. In addition, extraction and adsorption behaviors of the modified electrodes for carteolol hydrochloride were studied by chronocoulumetry, and the results showed that extraction during the enrichment process played a major role at low concentrations, and contribution of surface adsorption became greater with the increase of concentrations.

  16. Age determination of vessel wall hematoma in spontaneous cervical artery dissection: A multi-sequence 3T Cardiovascular Magnetic resonance study

    Directory of Open Access Journals (Sweden)

    Habs Maximilian

    2011-11-01

    Full Text Available Abstract Background Previously proposed classifications for carotid plaque and cerebral parenchymal hemorrhages are used to estimate the age of hematoma according to its signal intensities on T1w and T2w MR images. Using these classifications, we systematically investigated the value of cardiovascular magnetic resonance (CMR in determining the age of vessel wall hematoma (VWH in patients with spontaneous cervical artery dissection (sCAD. Methods 35 consecutive patients (mean age 43.6 ± 9.8 years with sCAD received a cervical multi-sequence 3T CMR with fat-saturated black-blood T1w-, T2w- and TOF images. Age of sCAD was defined as time between onset of symptoms (stroke, TIA or Horner's syndrome and the CMR scan. VWH were categorized into hyperacute, acute, early subacute, late subacute and chronic based on their signal intensities on T1w- and T2w images. Results The mean age of sCAD was 2.0, 5.8, 15.7 and 58.7 days in patients with acute, early subacute, late subacute and chronic VWH as classified by CMR (p Conclusions Signal intensities of VWH in sCAD vary over time and multi-sequence CMR can help to determine the age of an arterial dissection. Furthermore, findings of this study suggest that the time course of carotid hematomas differs from that of cerebral hematomas.

  17. Magnetic multi-wall carbon nanotube nanocomposite as an adsorbent for preconcentration and determination of lead (II) and manganese (II) in various matrices.

    Science.gov (United States)

    Daneshvar Tarigh, Ghazale; Shemirani, Farzaneh

    2013-10-15

    Magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was synthesized and used as an adsorbent for preconcentration and determination of lead (II) and manganese (II). The properties of MMWCNT were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Energy dispersive X-ray spectrometry (EDS) and fourier transform infrared spectrophotometer (FT-IR). This adsorbent was found to be advantageous over conventional solid phase extraction (SPE) in terms of operational simplicity and low time-consuming. MMWCNT, carrying target metals, was easily separated from the aqueous solutions with the help of an external magnet; so, no filtration or centrifugation was necessary. After extraction and collection of MMWCNT, the adsorbed analytes were eluted and analyzed by flame atomic absorption spectrometry (FAAS). Experiments were carried out to investigate the influence of different sorption/desorption parameters. Under the optimized conditions, detection limits and enhancement factors of the proposed method for Pb and Mn were 1.0 and 0.6 µg L(-1), 390 and 697 respectively. The presented procedure was successfully applied for determination of Pb(II) and Mn (II) contents in lipstick, rice samples and accuracy was evaluated analyzing a certified reference material Seronorm(™) Urine LOT NO2525.

  18. Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid.

    Science.gov (United States)

    Yang, Guangming; Li, Ling; Jiang, Jinhe; Yang, Yunhui

    2012-08-01

    Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02×10(-7)-5.23×10(-4) mol L(-1) and 1.43×10(-7)-4.64×10(-4) mol L(-1), the detection limits were 1.12×10(-8) mol L(-1) and 2.24×10(-8) mol L(-1), respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. A simple and sensitive method for the determination of 4-n-octylphenol based on multi-walled carbon nanotubes modified glassy carbon electrode

    Institute of Scientific and Technical Information of China (English)

    Qiaoli Zheng; Ping Yang; He Xu; Jianshe Liu; Litong Jin

    2012-01-01

    A simple and sensitive electroanalytical method was presented for the determination of 4-n-octylphenol (OP) based on multi-walled carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE).OP was directly oxidized on the MWCNTs/GCE,and the electrochemical oxidation mechanism was demonstrated by a one-electron and one-proton process in the reaction.The oxidation peak current of OP was significantly enhanced by the use of MWCNTs/GCE compared with those of bare glassy carbon electrode; suggesting that the modified electrode can remarkably improve the performance for OP determination.Factors influencing the detection processes were optimized.Under these optimal conditions,a linear relationship between concentration of OP and current response was obtained in the range of 5 × 10-8 to 1 × 10-5 mol/L with a detection limit of 1.5 × 10-8 mol/L and correlation coeffìcient 0.9986.The modified electrode showed good selectivity,sensitivity,reproducibility and high stability.

  20. Determination of uptake, accumulation, and stress effects in corn (Zea mays L.) grown in single-wall carbon nanotube contaminated soil.

    Science.gov (United States)

    Cano, Amanda M; Kohl, Kristina; Deleon, Sabrina; Payton, Paxton; Irin, Fahmida; Saed, Mohammad; Shah, Smit Alkesh; Green, Micah J; Cañas-Carrell, Jaclyn E

    2016-06-01

    Single-wall carbon nanotubes (SWNTs) are projected to increase in usage across many industries. Two studies were conducted using Zea L. (corn) seeds exposed to SWNT spiked soil for 40 d. In Study 1, corn was exposed to various SWNT concentrations (0, 10, and 100 mg/kg) with different functionalities (non-functionalized, OH-functionalized, or surfactant stabilized). A microwave induced heating method was used to determine SWNTs accumulated mostly in roots (0-24 μg/g), with minimal accumulation in stems and leaves (2-10 μg/g) with a limit of detection at 0.1 μg/g. Uptake was not functional group dependent. In Study 2, corn was exposed to 10 mg/kg SWNTs (non-functionalized or COOH-functionalized) under optimally grown or water deficit conditions. Plant physiological stress was determined by the measurement of photosynthetic rate throughout Study 2. No significant differences were seen between control and SWNT treatments. Considering the amount of SWNTs accumulated in corn roots, further studies are needed to address the potential for SWNTs to enter root crop species (i.e., carrots), which could present a significant pathway for human dietary exposure.

  1. Simultaneous determination of endocrine disrupting compounds bisphenol F and bisphenol AF using carboxyl functionalized multi-walled carbon nanotubes modified electrode.

    Science.gov (United States)

    Yang, Jichun; Wang, Xin; Zhang, Danfeng; Wang, Lingling; Li, Qi; Zhang, Lei

    2014-12-01

    A novel, simple and selective electrochemical method was developed for simultaneous determination of bisphenol F (BPF) and bisphenol AF (BPAF) in aqueous media (phosphate buffer solution, pH 6.0) on carboxyl functionalized multi-walled carbon nanotubes modified glassy carbon electrode (MWCNT-COOH/GCE) using differential pulse voltammetry (DPV). In DPV, MWCNT-COOH/GCE could separate the oxidation peak potentials of BPF and BPAF present in the same solution though, at the bare GCE, the peak potentials were indistinguishable. The results showed that the electrochemical sensor exhibited excellent electrocatalytic activity towards the oxidation of the two analytes. The peak current in DPV of BPF and BPAF increased linearly with their concentration in the ranges of 0.6-1.6 mmol/L BPF and 0.6-1.6 mmol/L BPAF. The detection limits were 0.1243 mmol/L and 0.1742 mmol/L (S/N=3) correspondingly. The modified electrode was successfully used to simultaneously determine BPF and BPAF in real samples.

  2. Single-walled carbon nanotubes as solid-phase microextraction adsorbent for the determination of low-level concentrations of butyltin compounds in seawater.

    Science.gov (United States)

    Rastkari, Noushin; Ahmadkhaniha, Reza; Samadi, Nasrin; Shafiee, Abbas; Yunesian, Masud

    2010-03-03

    Carbon nanotubes are a kind of new carbon-based nanomaterials, which have drawn great attention in many application fields. The potential of single-walled carbon nanotubes (SWCNTs) as solid-phase microextraction (SPME) adsorbent for the preconcentration of environmental pollutants has been investigated in recent years. In the present study, the feasibility of SWCNTs as SPME adsorbent for the determination of monobutyltin, dibutyltin and tributyltin in seawater samples was studied. To achieve this aim, the potential factors affecting the SPME efficiency, including extraction time, extraction temperature, desorption time, desorption temperature, and salinity were optimized. The developed method showed good performance according to the ICH (International Conference on Harmonization of Technical Requirements for Analytical Methods) criteria. The acquired calibration curves were linear (r > or = 0.992) over the concentration range from analytes, the limit of detection at signal-to-noise ratio of 3 was below 5 ng L(-1). Furthermore, in comparison with the commercial carboxen/polydimethylsiloxane fiber, the developed SWCNT fiber showed better thermal stability (over 350 degrees C) and longer life span (over 150 times). The application of the proposed method in environmental analyses was shown by analyzing seawater samples from the harbors on the Persian Gulf for butyltin residues. Some of the butyltins were detected in the analyzed samples. Results of the present study demonstrate the feasibility of the SWCNTs as SPME adsorbent for the determination of butyltins in seawater samples.

  3. Multi-residue determination of pesticides in water using multi-walled carbon nanotubes solid-phase extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Wang, Shuo; Zhao, Peng; Min, Guang; Fang, Guozhen

    2007-09-21

    A reliable multi-residue method which was based on solid-phase extraction (SPE) with multi-walled carbon nanotubes (MWCNTs) as adsorbent was developed for determination and quantitation of 12 pesticides (carbofuran, iprobenfos, parathion-methyl, prometryn, fenitrothion, parathion-ethyl, isocarbofos, phenthoate, methidathion, endrin, ethion, methoxychlor) in surface water by gas chromatography-mass spectrometry (GC-MS). Parameters that might influence the extraction efficiency such as the eluent volume, the sample flow rate and the sample loading volume were optimized. The experimental results showed the excellent linearity of 12 pesticides (R(2)>0.99) over the range of 0.04-4 microg L(-1), and the precisions (RSD) were 3.1-15.1% under the optimal conditions. The detection limits of proposed method could reach 0.01-0.03 microg L(-1) based on the ratio of chromatographic signal to base line noise (S/N=3). Good recoveries achieved with spiked water samples were in the range of 82.0-103.7%. The results indicated that MWCNTs have good adsorbability to the 12 pesticides tested in this study. With less cost, less analytical time and less solvent-consuming, the developed multi-residue method could be used to determine multi-class pesticides in water simultaneously.

  4. An enhanced electrochemical platform based on graphene oxide and multi-walled carbon nanotubes nanocomposite for sensitive determination of Sunset Yellow and Tartrazine.

    Science.gov (United States)

    Qiu, Xinlan; Lu, Limin; Leng, Jing; Yu, Yongfang; Wang, Wenmin; Jiang, Min; Bai, Ling

    2016-01-01

    A novel electrochemical platform was designed for the simultaneous determination of Sunset Yellow (SY) and Tartrazine (TT), synthetic food dyes, by combining the signal amplification properties of graphene oxide (GO) and the excellent electronic and antifouling properties of multi-walled carbon nanotubes (MWCNTs). Stable dispersion of GO/MWCNTs composite was produced by sonication mixing. Compared with glassy carbon, MWCNTs and GO electrodes, GO/MWCNTs electrode exhibited strong enhancement effect and greatly increased the oxidation signal of SY and TT. Under optimized conditions, the enhanced anodic peak currents represented the excellent analytical performance of simultaneous detection of SY and TT in the range of 0.09-8.0 μM, with a low limit of detection of 0.025 μM for SY and 0.01 μM for TT (S/N = 3), respectively. To further validate its possible application, the proposed method was successfully used for the determination of SY and TT in orange juice with satisfactory results.

  5. A DNA biosensor based on gold nanoparticle decorated on carboxylated multi-walled carbon nanotubes for gender determination of Arowana fish.

    Science.gov (United States)

    Saeedfar, Kasra; Heng, Lee Yook; Chiang, Chew Poh

    2017-12-01

    Multi-wall carbon nanotubes (MWCNTs) were modified to design a new DNA biosensor. Functionalized MWCNTs were equipped with gold nanoparticles (GNPs) (~15nm) (GNP-MWCNTCOOH) to construct DNA biosensors based on carbon-paste screen-printed (SPE) electrodes. GNP attachment onto functionalized MWCNTs was carried out by microwave irradiation and was confirmed by spectroscopic studies and surface analysis. DNA biosensors based on differential pulse voltammetry (DPV) were constructed by immobilizing thiolated single-stranded DNA probes onto GNP-MWCNTCOOH. Ruthenium (III) chloride hexaammoniate [Ru(NH3)6,2Cl(-)] (RuHex) was used as hybridization redox indicator. RuHex and MWCNT interaction was low in compared to other organic redox hybridization indicators. The linear response range for DNA determination was 1×10(-21) to 1×10(-9)M with a lower detection limit of 1.55×10(-21)M. Thus, the attachment of GNPs onto functionalized MWCNTs yielded sensitive DNA biosensor with low detection limit and stability more than 30days. Constructed electrode was used to determine gender of arowana fish. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Left ventricular wall stress compendium.

    Science.gov (United States)

    Zhong, L; Ghista, D N; Tan, R S

    2012-01-01

    Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

  7. Experimental Investigations into the Use of Piezoelectric Film Transducers to Determine Particle Size through Impact Analysis

    OpenAIRE

    Coombes, James Robert; Yan, Yong

    2016-01-01

    Sensors are required to determine the particle size of granular materials in a variety of industries such as energy, chemical manufacturing and food processing. The importance of accurately monitoring the particle size is essential in quality control in these industrial sectors. This paper presents the use of a custom made piezoelectric PVDF film transducer that is capable of determining the particle size of granular material through impact analysis. Experiments were carried out using a purpo...

  8. Examination of Single-Walled Carbon Nanotubes Uptake and Toxicity from Dietary Exposure: Tracking Movement and Impacts in the Gastrointestinal System.

    Science.gov (United States)

    Bisesi, Joseph H; Ngo, Thuy; Ponnavolu, Satvika; Liu, Keira; Lavelle, Candice M; Afrooz, A R M Nabiul; Saleh, Navid B; Ferguson, P Lee; Denslow, Nancy D; Sabo-Attwood, Tara

    2015-06-12

    Previous studies indicate that exposure of fish to pristine single-walled carbon nanotubes (SWCNTs) by oral gavage, causes no overt toxicity, and no appreciable absorption has been observed. However, in the environment, SWCNTs are likely to be present in dietary sources, which may result in differential impacts on uptake and biological effects. Additionally, the potential of these materials to sorb nutrients (proteins, carbohydrates, and lipids) while present in the gastrointestinal (GI) tract may lead to nutrient depletion conditions that impact processes such as growth and reproduction. To test this phenomenon, fathead minnows were fed a commercial diet either with or without SWCNTs for 96 h. Tracking and quantification of SWCNTs using near-infrared fluorescence (NIRF) imaging during feeding studies showed the presence of food does not facilitate transport of SWCNTs across the intestinal epithelia. Targeting genes shown to be responsive to nutrient depletion (peptide transporters, peptide hormones, and lipases) indicated that pept2, a peptide transporter, and cck, a peptide hormone, showed differential mRNA expression by 96 h, a response that may be indicative of nutrient limitation. The results of the current study increase our understanding of the movement of SWCNTs through the GI tract, while the changes in nutrient processing genes highlight a novel mechanism of sublethal toxicity in aquatic organisms.

  9. Examination of Single-Walled Carbon Nanotubes Uptake and Toxicity from Dietary Exposure: Tracking Movement and Impacts in the Gastrointestinal System

    Directory of Open Access Journals (Sweden)

    Joseph H. Bisesi

    2015-06-01

    Full Text Available Previous studies indicate that exposure of fish to pristine single-walled carbon nanotubes (SWCNTs by oral gavage, causes no overt toxicity, and no appreciable absorption has been observed. However, in the environment, SWCNTs are likely to be present in dietary sources, which may result in differential impacts on uptake and biological effects. Additionally, the potential of these materials to sorb nutrients (proteins, carbohydrates, and lipids while present in the gastrointestinal (GI tract may lead to nutrient depletion conditions that impact processes such as growth and reproduction. To test this phenomenon, fathead minnows were fed a commercial diet either with or without SWCNTs for 96 h. Tracking and quantification of SWCNTs using near-infrared fluorescence (NIRF imaging during feeding studies showed the presence of food does not facilitate transport of SWCNTs across the intestinal epithelia. Targeting genes shown to be responsive to nutrient depletion (peptide transporters, peptide hormones, and lipases indicated that pept2, a peptide transporter, and cck, a peptide hormone, showed differential mRNA expression by 96 h, a response that may be indicative of nutrient limitation. The results of the current study increase our understanding of the movement of SWCNTs through the GI tract, while the changes in nutrient processing genes highlight a novel mechanism of sublethal toxicity in aquatic organisms.

  10. Determinants of Shift Work impacting Job Satisfaction: A study on Service Sector Organizations in Pakistan

    Directory of Open Access Journals (Sweden)

    Wasim Abbas Awan

    2013-10-01

    Full Text Available This study aims to investigate the impact of determinants of shift work on job satisfaction in service sector organizations of Pakistan. History reveals that the invention of Thomas Edison brought the change in working environment and industrial revolution results in the birth of shift works. A great number of theories in Management are there to define Job satisfaction. All of them show the relationship between ability to perform and the productivity. In order to investigate their impact descriptive study is taken in to account in which survey research method is used to collect data. On the basis of quantitative analysis this study reveals that determinants of shift work has positive impact on job satisfaction. Finally recommendations are made to increase shift work in service sector organizations of Pakistan so that people may upraise their standards of living.

  11. What determines video game use? The impact of users’ habits, addictive tendencies, and intentions to play

    NARCIS (Netherlands)

    Hartmann, T.; Jung, Y.; Vorderer, P.A.

    2012-01-01

    The present study explores the role of intentions, habits, and addictive tendencies in people’s video game use. Although both habits and addictive tendencies may determine higher amounts of video game use, the present study examines whether the impact of habits and addictive tendencies on video game

  12. Determinants of impact of a practice accreditation program in primary care: a qualitative study

    NARCIS (Netherlands)

    Nouwens, E.; Lieshout, J. van; Wensing, M.

    2015-01-01

    BACKGROUND: Practice accreditation is a widely used method to assess and improve the quality of healthcare services. In the Netherlands, a practice accreditation program was implemented in primary medical care. We aimed to identify determinants of impact of a practice accreditation program, building

  13. Impact of uncertainties in discharge determination on the parameter estimation and performance of a hydrological model

    NARCIS (Netherlands)

    Tillaart, van den S.P.M.; Booij, M.J.; Krol, M.S

    2013-01-01

    Uncertainties in discharge determination may have serious consequences for hydrological modelling and resulting discharge predictions used for flood forecasting, climate change impact assessment and reservoir operation. The aim of this study is to quantify the effect of discharge errors on parameter

  14. Determinants and Impacts Of Human Mobility Dynamics In The Western Highlands Of Cameroon

    NARCIS (Netherlands)

    Tankou, C.M.; Iongh, de H.H.; Persoon, G.; Bruijn, de M.E.; Snoo, de G.R.

    2014-01-01

    This study analyses human mobility among inhabitants of Cameroon‘s most populous region, the Western Highlands of Cameroon. In other to capture the impact of various determinants on human mobility, a comparative study was conducted through household and field surveys in three villages in the region

  15. Determinants of impact of a practice accreditation program in primary care: a qualitative study

    NARCIS (Netherlands)

    Nouwens, E.; Lieshout, J. van; Wensing, M.

    2015-01-01

    BACKGROUND: Practice accreditation is a widely used method to assess and improve the quality of healthcare services. In the Netherlands, a practice accreditation program was implemented in primary medical care. We aimed to identify determinants of impact of a practice accreditation program, building

  16. A prospective study comparing the functional impact of SIEA, DIEP, and muscle-sparing free TRAM flaps on the abdominal wall: Part II. Bilateral reconstruction.

    Science.gov (United States)

    Selber, Jesse C; Fosnot, Joshua; Nelson, Jonas; Goldstein, Jesse; Bergey, Meredith; Sonnad, Seema; Serletti, Joseph M

    2010-11-01

    The purpose of this study was to demonstrate the impact of bilateral free flap breast reconstruction on the abdominal wall. This is the second installation of a two-part series. Presented here are bilateral combinations of three techniques: the muscle-sparing free transverse rectus abdominis musculocutaneous (TRAM) flap, deep inferior epigastric perforator (DIEP) flap, and superficial inferior epigastric artery (SIEA) flap. A blinded prospective cohort study was performed involving 234 patients. Patients were evaluated preoperatively and for 1 year postoperatively. At each encounter, patients underwent objective abdominal strength testing using the Manual Muscle Function Test and Functional Independence Measure and psychometric testing using the Short Form 36 questionnaire. At postoperative visits, patients also completed a questionnaire specific to breast reconstruction. Statistical analysis included the Kruskal-Wallis, Mann-Whitney, Friedman, and Wilcoxon signed rank tests. A total of 234 patients were enrolled. Of these, 157 underwent reconstruction, 82 of which were bilateral. There was a significant decline in upper (p=0.02) and lower (p=0.05) abdominal strength from bilateral free TRAM flaps compared with bilateral DIEP flaps. Likewise, there was a significant decline in upper (p=0.055) and lower (p=0.04) abdominal strength from bilateral free TRAM flaps compared with bilateral SIEA flaps. For combinations, the most muscle impairment to least was as follows: free TRAM/free TRAM, free TRAM/DIEP, DIEP/DIEP, DIEP/SIEA, and SIEA/SIEA. The free TRAM/SIEA data were not significant. Although psychometric testing showed trends, there was no significant difference among treatment groups. Abdominal wall strength following various combinations of bilateral free flap breast reconstruction techniques closely adheres to theoretical predictions based on the degree of surgical muscle sacrifice.

  17. Accumulation of Peptidoglycan O-Acetylation Leads to Altered Cell Wall Biochemistry and Negatively Impacts Pathogenesis Factors of Campylobacter jejuni.

    Science.gov (United States)

    Ha, Reuben; Frirdich, Emilisa; Sychantha, David; Biboy, Jacob; Taveirne, Michael E; Johnson, Jeremiah G; DiRita, Victor J; Vollmer, Waldemar; Clarke, Anthony J; Gaynor, Erin C

    2016-10-21

    Campylobacter jejuni is a leading cause of bacterial gastroenteritis in the developed world. Despite its prevalence, its mechanisms of pathogenesis are poorly understood. Peptidoglycan (PG) is important for helical shape, colonization, and host-pathogen interactions in C. jejuni Therefore, changes in PG greatly impact the physiology of this organism. O-acetylation of peptidoglycan (OAP) is a bacterial phenomenon proposed to be important for proper cell growth, characterized by acetylation of the C6 hydroxyl group of N-acetylmuramic acid in the PG glycan backbone. The OAP gene cluster consists of a PG O-acetyltransferase A (patA) for translocation of acetate into the periplasm, a PG O-acetyltransferase B (patB) for O-acetylation, and an O-acetylpeptidoglycan esterase (ape1) for de-O-acetylation. In this study, reduced OAP in ΔpatA and ΔpatB had minimal impact on C. jejuni growth and fitness under the conditions tested. However, accumulation of OAP in Δape1 resulted in marked differences in PG biochemistry, including O-acetylation, anhydromuropeptide levels, and changes not expected to result directly from Ape1 activity. This suggests that OAP may be a form of substrate level regulation in PG biosynthesis. Ape1 acetylesterase activity was confirmed in vitro using p-nitrophenyl acetate and O-acetylated PG as substrates. In addition, Δape1 exhibited defects in pathogenesis-associated phenotypes, including cell shape, motility, biofilm formation, cell surface hydrophobicity, and sodium deoxycholate sensitivity. Δape1 was also impaired for chick colonization and adhesion, invasion, intracellular survival, and induction of IL-8 production in INT407 cells in vitro The importance of Ape1 in C. jejuni biology makes it a good candidate as an antimicrobial target. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Accumulation of Peptidoglycan O-Acetylation Leads to Altered Cell Wall Biochemistry and Negatively Impacts Pathogenesis Factors of Campylobacter jejuni*

    Science.gov (United States)

    Ha, Reuben; Frirdich, Emilisa; Sychantha, David; Biboy, Jacob; Taveirne, Michael E.; Johnson, Jeremiah G.; DiRita, Victor J.; Vollmer, Waldemar; Clarke, Anthony J.; Gaynor, Erin C.

    2016-01-01

    Campylobacter jejuni is a leading cause of bacterial gastroenteritis in the developed world. Despite its prevalence, its mechanisms of pathogenesis are poorly understood. Peptidoglycan (PG) is important for helical shape, colonization, and host-pathogen interactions in C. jejuni. Therefore, changes in PG greatly impact the physiology of this organism. O-acetylation of peptidoglycan (OAP) is a bacterial phenomenon proposed to be important for proper cell growth, characterized by acetylation of the C6 hydroxyl group of N-acetylmuramic acid in the PG glycan backbone. The OAP gene cluster consists of a PG O-acetyltransferase A (patA) for translocation of acetate into the periplasm, a PG O-acetyltransferase B (patB) for O-acetylation, and an O-acetylpeptidoglycan esterase (ape1) for de-O-acetylation. In this study, reduced OAP in ΔpatA and ΔpatB had minimal impact on C. jejuni growth and fitness under the conditions tested. However, accumulation of OAP in Δape1 resulted in marked differences in PG biochemistry, including O-acetylation, anhydromuropeptide levels, and changes not expected to result directly from Ape1 activity. This suggests that OAP may be a form of substrate level regulation in PG biosynthesis. Ape1 acetylesterase activity was confirmed in vitro using p-nitrophenyl acetate and O-acetylated PG as substrates. In addition, Δape1 exhibited defects in pathogenesis-associated phenotypes, including cell shape, motility, biofilm formation, cell surface hydrophobicity, and sodium deoxycholate sensitivity. Δape1 was also impaired for chick colonization and adhesion, invasion, intracellular survival, and induction of IL-8 production in INT407 cells in vitro. The importance of Ape1 in C. jejuni biology makes it a good candidate as an antimicrobial target. PMID:27474744

  19. A Sensitive Simultaneous Determination of Adrenalin and Paracetamol on a Glassy Carbon Electrode Coated with a Film of Chitosan/Room Temperature Ionic Liquid/Single-Walled Carbon Nanotubes Nanocomposite%A Sensitive Simultaneous Determination of Adrenalin and Paracetamol on a Glassy Carbon Electrode Coated with a Film of Chitosan/Room Temperature Ionic Liquid/Single-Walled Carbon Nanotubes Nanocomposite

    Institute of Scientific and Technical Information of China (English)

    Babaei, Ali; Babazadeh, Mitra; Afrasiabi, Mohammad

    2011-01-01

    The present work demonstrates that simultaneous determination of adrenalin (AD) and paracetamol (PAR) can be performed on single-walled carbon nanotube/chitosan/ionic liquid modified glassy carbon electrode (SWCNT-CHIT-IL/GCE). The electro-oxidations of AD and PAR were investigated with cyclic voltammetry (CV), differential pulse voltammetry (DPV) and also chronoamperometry (CA) methods. DPV experiments showed that the oxidation peak currents of AD and PAR are proportional to the corresponding concentrations over the 1-580 μmol/L and 0.5-400 μmol/L ranges, respectively. The RSD at a concentration level of 15 μmol/L AD and 15 μmol/L PAR were 1.69% and 1.82%, respectively. Finally the modified electrode was used for simultaneous determination of AD and PAR in real samples with satisfactory results.

  20. Impact of photon cross section systematic uncertainties on Monte Carlo-determined depth-dose distributions

    CERN Document Server

    Aguirre, Eder; David, Mariano; deAlmeida, Carlos E

    2016-01-01

    This work studies the impact of systematic uncertainties associated to interaction cross sections on depth dose curves determined by Monte Carlo simulations. The corresponding sensitivity factors are quantified by changing cross sections in a given amount and determining the variation in the dose. The influence of total cross sections for all particles, photons and only for Compton scattering is addressed. The PENELOPE code was used in all simulations. It was found that photon cross section sensitivity factors depend on depth. In addition, they are positive and negative for depths below and above an equilibrium depth, respectively. At this depth, sensitivity factors are null. The equilibrium depths found in this work agree very well with the mean free path of the corresponding incident photon energy. Using the sensitivity factors reported here, it is possible to estimate the impact of photon cross section uncertainties on the uncertainty of Monte Carlo-determined depth dose curves.

  1. Multi-walled carbon nanotube modified dummy-template magnetic molecularly imprinted microspheres as solid-phase extraction material for the determination of polychlorinated biphenyls in fish.

    Science.gov (United States)

    Du, Xiaowen; Lin, Saichai; Gan, Ning; Chen, Xidong; Cao, Yuting; Li, Tianhua; Zhan, Pan

    2014-07-01

    Novel multi-walled carbon nanotube modified dummy-template molecularly imprinted microspheres (MWCNTs@DMMIPs) were successfully synthesized as adsorbents for six kinds of polychlorinated biphenyls (PCBs). MWCNTs@DMMIPs were prepared by a surface molecular imprinting technique. Core-shell Fe3 O4 @SiO2 nanoparticles were employed as magnetic support. 3,4-Dichlorobenzene acetic acid was used as a dummy template instead of PCBs, methacrylic acid was used as functional monomer and ethylene glycol dimethacrylate was used as the cross-linker. The resulting absorbent was characterized by various methods. The adsorbent was employed for extracting PCBs and exhibited good selectivity and high adsorption efficiency. Furthermore, it was reusable and capable of magnetic separation. Adsorption kinetics fit well with a pseudo-second-order kinetic equation and also exhibited a three-stage intra-particle diffusion model. The Freundlich model was used to describe the adsorption isotherms. The materials were successfully applied to the magnetic dispersive solid-phase extraction of six kinds of PCBs followed by gas chromatography with mass spectrometry determination in fish samples, the limit of detection of six kinds of PCBs were 0.0028-0.0068 μg/L and spiked recoveries ranged between 73.41 and 114.21%. The prepared adsorbent was expected to be a new material for the removal and recovery of PCBs from contaminated foods.

  2. Determination of guanine and adenine by high-performance liquid chromatography with a self-fabricated wall-jet/thin-layer electrochemical detector at a glassy carbon electrode.

    Science.gov (United States)

    Zhou, Yaping; Yan, Hongling; Xie, Qingji; Yao, Shouzhuo

    2015-03-01

    A sensitive wall-jet/thin-layer amperometric electrochemical detector (ECD) coupled to high-performance liquid chromatography (HPLC) was developed for simultaneous determination of guanine (G) and adenine (A). The analytes were detected at a glassy carbon electrode (GCE) and the HPLC-ECD calibration curves showed good linearity (R(2)>0.997) under optimized conditions. Limits of detection for G and A are 0.6 nM and 1.4 nM (S/N=3), respectively, which are lower than those obtained with an UV-vis detector and a commercial electrochemical detector. We have successfully applied this HPLC-ECD to assess the contents of G and A in hydrochloric acid-digested calf thymus double-stranded DNA. In addition, we compared in detail the analysis of G and A by cyclic voltammetry (CV) and by the HPLC-ECD system on both bare GCE and electroreduced graphene oxide (ERGO) modified GCE. We found that the adsorption of G and A on the electrode surfaces can vary their anodic CV peaks and the competitive adsorption of G and A on the limited sites of the electrode surfaces can cause crosstalk effects on their anodic CV peak signals, but the HPLC-ECD system is insensitive to such electrode-adsorption and can give more reliable analytical results. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The Cu-MOF-199/single-walled carbon nanotubes modified electrode for simultaneous determination of hydroquinone and catechol with extended linear ranges and lower detection limits.

    Science.gov (United States)

    Zhou, Jian; Li, Xi; Yang, Linlin; Yan, Songlin; Wang, Mengmeng; Cheng, Dan; Chen, Qi; Dong, Yulin; Liu, Peng; Cai, Weiquan; Zhang, Chaocan

    2015-10-29

    A novel electrochemical sensor based on Cu-MOF-199 [Cu-MOF-199 = Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylicacid)] and SWCNTs (single-walled carbon nanotubes) was fabricated for the simultaneous determination of hydroquinone (HQ) and catechol (CT). The modification procedure was carried out through casting SWCNTs on the bare glassy carbon electrode (GCE) and followed by the electrodeposition of Cu-MOF-199 on the SWCNTs modified electrode. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) were performed to characterize the electrochemical performance and surface characteristics of the as-prepared sensor. The composite electrode exhibited an excellent electrocatalytic activity with increased electrochemical signals towards the oxidation of HQ and CT, owing to the synergistic effect of SWCNTs and Cu-MOF-199. Under the optimized condition, the linear response range were from 0.1 to 1453 μmol L(-1) (RHQ = 0.9999) for HQ and 0.1-1150 μmol L(-1) (RCT = 0.9990) for CT. The detection limits for HQ and CT were as low as 0.08 and 0.1 μmol L(-1), respectively. Moreover, the modified electrode presented the good reproducibility and the excellent anti-interference performance. The analytical performance of the developed sensor for the simultaneous detection of HQ and CT had been evaluated in practical samples with satisfying results.

  4. [Determination of 21 organophosphorus pesticides in tea by gas chromatography-mass spectrometry coupled with hydroxylated multi-walled carbon nanotubes based on dispersive solid-phase extraction].

    Science.gov (United States)

    Rong, Jiefeng; Wei, Hang; Li, Yijun; Huang, Huoshui; Xu, Meizhu

    2016-02-01

    A rapid determination method of 21 organophosphorus pesticides in tea was developed by QuEChERS method using modified multi-walled carbon nanotubes (MWCNTs-OH), primary-secondary amine (PSA) and MgSO4 coupled with gas chromatography-mass spectrometry. The pesticide residues in tea were extracted with a hexane-acetone (2:1, v/v) mixture, and cleaned up by dispersive solid-phase extraction using MWCNTs-OH and primary-secondary amine (PSA) as the sorbents. After centrifugation and filtration, the target compounds were analyzed by gas chromatography-mass spectrometry and quantified by the external standard method. Under the optimized conditions, good linearities were obtained in the range of 0. 01- 0. 50 mg/kg. The average recoveries were in the range of 81. 5% -109. 4% at three spiked levels, with relative standard deviations (RSDs, n = 5 ) of 2. 3% - 10. 6%. The limits of quantification were 0. 001-0. 040 mg/kg. This method is simple, fast, sensitive, cheap, and can meet the requirements of the rapid detection of organophosphorus pesticides in tea.

  5. Ho{sup 3+} carbon paste sensor based on multi-walled carbon nanotubes: Applied for determination of holmium content in biological and environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Faridbod, Farnoush [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza, E-mail: ganjali@khayam.ut.ac.ir [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Larijani, Bagher [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Hosseini, Morteza [Department of Chemistry, Islamic Azad University, Savadkooh Branch, Savadkooh (Iran, Islamic Republic of); Norouzi, Parviz [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2010-05-10

    For the first time a novel multi-walled carbon nanotubes (MWCNTs) modified Ho{sup 3+} carbon paste sensor is introduced. The electrode with a composition containing 20% paraffin oil, 60% graphite powder, 15% N-(1-thia-2-ylmethylene)-1,3-benzothiazole-2-amine (TBA) as an ionophore, and 5% MWCNTs, exhibits a stable potential response to Ho{sup 3+} ions with a nice Nernstian behavior (19.3 {+-} 0.3 mV decade{sup -1}) in a wide dynamic linear concentration range of Ho{sup 3+} ions (1 x 10{sup -8}-1.0 x 10{sup -2} M). In the absence of MWCNTs, sensitivity of the Ho{sup 3+} sensor was relatively poor. The proposed modified Ho{sup 3+} sensor shows very low detection limit (7.0 x 10{sup -9} M) and a fast response time (13 s). It has a long life time (more than 2 months) and its response is independent of pH in the range of 3.8-7.5. In term of selectivity, Ho{sup 3+} sensor has a good selectivity over all lanthanide members and common alkali and alkaline earth metal ions. The Ho{sup 3+} sensor was applied for the determination of Ho{sup 3+} ion concentration in water, holmium alloys and synthetic human serum.

  6. Quantitative determination and toxicity evaluation of 2,4-dichlorophenol using poly(eosin Y)/hydroxylated multi-walled carbon nanotubes modified electrode

    Science.gov (United States)

    Zhu, Xiaolin; Zhang, Kexin; Wang, Chengzhi; Guan, Jiunian; Yuan, Xing; Li, Baikun

    2016-12-01

    This study aimed at developing simple, sensitive and rapid electrochemical approach to quantitatively determine and assess the toxicity of 2,4-dichlorophenol (2,4-DCP), a priority pollutant and has potential risk to public health through a novel poly(eosin Y, EY)/hydroxylated multi-walled carbon nanotubes composite modified electrode (PEY/MWNTs-OH/GCE). The distinct feature of this easy-fabricated electrode was the synergistic coupling effect between EY and MWNTs-OH that enabled a high electrocatalytic activity to 2,4-DCP. Under optimum conditions, the oxidation peak current enhanced linearly with concentration increasing from 0.005 to 0.1 μM and 0.2 to 40.0 μM, and revealed the detection limit of 1.5 nM. Moreover, the PEY/MWNTs-OH/GCE exhibited excellent electrocatalytic activity toward intracellular electroactive species. Two sensitive electrochemical signals ascribed to guanine/xanthine and adenine/hypoxanthine in human hepatoma (HepG2) cells were detected simultaneously. The sensor was successfully applied to evaluate the toxicity of 2,4-DCP to HepG2 cells. The IC50 values based on the two electrochemical signals are 201.07 and 252.83 μM, respectively. This study established a sensitive platform for the comprehensive evaluation of 2,4-DCP and posed a great potential to simplify environmental toxicity monitoring.

  7. Highlighting the Socio-Demographic Differences of the Key Determinants of Staff’s Satisfaction in Jordanian Hospitals. An Empirical Analysis Based on Warr-Cool-Wall Scales

    Directory of Open Access Journals (Sweden)

    Adriana AnaMaria DAVIDESCU

    2016-12-01

    Full Text Available The aim of this paper is to highlight the socio-demographic differences regarding the main determinants of employee satisfaction in Jordanian hospitals using a sample of 325 employees from six different hospitals in 2015. Therefore, it has been used Warr-Cook-Wall scale in order to assess job satisfaction according to four dimensions: extrinsic job satisfaction, intrinsic job satisfaction, working conditions satisfaction, employee relations satisfaction. The socio-demographic differences on the job satisfaction factors were analyzed using t-test, Anova test and correlation coefficients. The empirical results pointed out that young and older employees express higher degrees of satisfaction comparative with other age group regarding the extrinsic satisfaction and employee relations and that administrative staff, helpers and doctors are more satisfied intrinsic satisfaction, extrinsic satisfaction, working conditions, employee relations and also on the overall level of satisfaction. Also individuals from horizontal structure exhibit higher levels of satisfaction regarding the job satisfaction factors than the ones from vertical structure.

  8. Determining the Conditions for the Hydraulic Impacts Emergence at Hydraulic Systems

    Directory of Open Access Journals (Sweden)

    Mazurenko A.S.

    2017-08-01

    Full Text Available This research aim is to develop a method for modeling the conditions for the critical hydrau-lic impacts emergence on thermal and nuclear power plants’ pipeline systems pressure pumps depart-ing from the general provisions of the heat and hydrodynamic instability theory. On the developed method basis, the conditions giving rise to the reliability-critical hydraulic impacts emergence on pumps for the thermal and nuclear power plants’ typical pipeline system have been determined. With the flow characteristic minimum allowable (critical sensitivity, the flow velocity fluctuations ampli-tude reaches critical values at which the pumps working elements’ failure occurs. The critical hydrau-lic impacts emergence corresponds to the transition of the vibrational heat-hydrodynamic instability into an aperiodic one. As research revealed, a highly promising approach as to the preventing the criti-cal hydraulic impacts related to the foreground use of pumps having the most sensitive consumption (at supply network performance (while other technical characteristics corresponding to that parame-ter. The research novelty refers to the suggested method elaborated by the authors’ team, which, in contrast to traditional approaches, is efficient in determining the pump hydraulic impact occurrence conditions when the vibrational heat-hydrodynamic instability transition to the aperiodic instability.

  9. Asymptotic Dynamics of Monopole Walls

    CERN Document Server

    Cross, R

    2015-01-01

    We determine the asymptotic dynamics of the U(N) doubly periodic BPS monopole in Yang-Mills-Higgs theory, called a monopole wall, by exploring its Higgs curve using the Newton polytope and amoeba. In particular, we show that the monopole wall splits into subwalls when any of its moduli become large. The long-distance gauge and Higgs field interactions of these subwalls are abelian, allowing us to derive an asymptotic metric for the monopole wall moduli space.

  10. Wall Art

    Science.gov (United States)

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  11. Multi-walled carbon nanotube/poly(glycine) modified carbon paste electrode for the determination of dopamine in biological fluids and pharmaceuticals.

    Science.gov (United States)

    Thomas, Tony; Mascarenhas, Ronald J; Swamy, B E Kumara; Martis, Praveen; Mekhalif, Zineb; Sherigara, B S

    2013-10-01

    A modified carbon paste electrode (CPE) for the selective detection of dopamine (DA) in presence of large excess of ascorbic acid (AA) and uric acid (UA) at physiological pH has been fabricated by bulk modification of CPE with multi-walled carbon nanotubes (MWCNTs) followed by electropolymerization of glycine (Gly). The surface morphology is compared using SEM images. The presence of nitrogen was confirmed by the energy dispersion X-ray spectroscopy (EDS) indicating the polymerization of Gly on the surface of the modified electrode. The impedance study indicates a better charge transfer kinetics for DA at CPE modified with MWCNT/polyglycine electrode. The presence of MWCNTs in carbon paste matrix triggers the extent of electropolymerization of Gly and imparts more selectivity towards DA by electrochemically not sensing AA below a concentration of 3.1×10(-4)M. Due to the exclusion of the signal for AA, the interference of AA in the determination of DA is totally ruled out by DPV method which is used for its detection at lower concentrations. Large peak separation, good sensitivity, reproducibility and stability allow this modified electrode to analyze DA individually and simultaneously along with AA and UA. Detection limit of DA was determined from differential pulse voltammetric (DPV) study and found to be 1.2×10(-8)M with a linear dynamic range of 5.0×10(-7)M to 4.0×10(-5)M. The practical analytical application of this electrode was demonstrated by measurement of DA content in dopamine hydrochloride injection and human blood serum.

  12. Simultaneous determination of mycophenolate mofetil and its active metabolite, mycophenolic acid, by differential pulse voltammetry using multi-walled carbon nanotubes modified glassy carbon electrode.

    Science.gov (United States)

    Madrakian, Tayyebeh; Soleimani, Mohammad; Afkhami, Abbas

    2014-09-01

    A highly sensitive electrochemical sensor for the simultaneous determination of mycophenolate mofetil (MPM) and mycophenolic acid (MPA) was fabricated by multi-walled carbon nanotubes modified glassy carbon electrode (MWCNTs/GCE). The electrochemical behavior of these two drugs was studied at the modified electrode using cyclic voltammetry and adsorptive differential pulse voltammetry. MPM and MPA were oxidized at the GCE during an irreversible process. DPV analysis showed two oxidation peaks at 0.87V and 1.1V vs. Ag/AgCl for MPM and an oxidation peak at 0.87V vs. Ag/AgCl for MPA in phosphate buffer solution of pH5.0. The MWCNTs/GCE displayed excellent electrochemical activities toward oxidation of MPM and MPA relative to the bare GCE. The experimental design algorithm was used for optimization of DPV parameters. The electrode represents linear responses in the range 5.0×10(-6) to 1.6×10(-4)molL(-1) and 2.5×10(-6)molL(-1) to 6.0×10(-5)molL(-1) for MPM and MPA, respectively. The detection limit was found to be 9.0×10(-7)molL(-1) and 4.0×10(-7)molL(-1) for MPM and MPA, respectively. The modified electrode showed a good sensitivity and stability. It was successfully applied to the simultaneous determination of MPM and MPA in plasma and urine samples.

  13. Static and dynamic buckling of thin-walled plate structures

    CERN Document Server

    Kubiak, Tomasz

    2013-01-01

    This monograph deals with buckling and postbuckling behavior of thin plates and thin-walled structures with flat wall subjected to static and dynamic load. The investigations are carried out in elastic range. The basic assumption here is the  thin plate theory. This method is used to determination the buckling load and postbuckling analysis of thin-walled structures subjected to static and dynamic load. The book introduces two methods for static and dynamic buckling investigation which allow for a wider understanding of the phenomenon. Two different methods also can allow uncoupling of the phenomena occurring at the same time and attempt to estimate their impact on the final result. A general mathematical model, adopted in proposed analytical-numerical method, enables the consideration of all types of stability loss i.e.local, global and interactive forms of buckling. The applied numerical-numerical method includes adjacent of walls, shear-lag phenomenon and a deplanation of cross-sections.

  14. CosmoQuest: Supporting Subject Matter Experts in Broadening the Impacts of their Work beyond their Institutional Walls.

    Science.gov (United States)

    Noel-Storr, J.; Buxner, S.; Grier, J.; Gay, P.

    2016-12-01

    CosmoQuest is a virtual research facility, which, like its physical counterparts, provides tools for scientists to acquire reduced data products (thanks to our cadre of citizen scientists working to analyze images and produce results online), and also to participate in education and outreach activities either directly through CosmoQuest activities (such as CosmoAcademy and the Educators' Zone) or with the support of CosmoQuest. Here, we present our strategies to inspire, engage and support Subject Matter Experts (SMEs - Scientists, Engineers, Technologists and Mathematicians) in activities outside of their institutions, and beyond college classroom teaching. We provide support for SMEs who are interested in increasing the impacts of their science knowledge and expertise by interacting with people online, or in other venues outside of their normal work environment. This includes a broad spectrum of opportunities for those interested in hosting webinars; running short courses for the public; using Facebook, Twitter or other social media to communicate science; or other diverse activities such as supporting an open house, science fair, or star party. As noted by Katheryn Woods-Townsend and colleagues, "...face-to-face interactions with scientists allowed students to view scientists as approachable and normal people, and to begin to understand the range of scientific areas and careers that exist. Scientists viewed the scientist-student interactions as a vehicle for science communication" (2015). As CosmoQuest fosters these relationships, it We present a framework for SMEs which combine opportunities for continuing professional development (virtually and in person at conferences) with ongoing online support, creating a dynamic professional learning network. The goal of this is to deepen SME capacity-knowledge, attitudes and behaviors-both encouraging and empowering them to connect to broader audiences in new ways.

  15. Novel Methods to Determine Feeder Locational PV Hosting Capacity and PV Impact Signatures

    Energy Technology Data Exchange (ETDEWEB)

    Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Coogan, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Seuss, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    Often PV hosting capacity analysis is performed for a limited number of distribution feeders. For medium - voltage distribution feeders, previous results generally analyze less than 20 feeders, and then the results are extrapolated out to similar types of feeders. Previous hosting capacity research has often focused on determining a single value for the hosting capacity for the entire feeder, whereas this research expands previous hosting capacity work to investigate all the regions of the feeder that may allow many different hosting capacity values wit h an idea called locational hosting capacity (LHC)to determine the largest PV size that can be interconnected at different locations (buses) on the study feeders. This report discusses novel methods for analyzing PV interconnections with advanced simulati on methods. The focus is feeder and location - specific impacts of PV that determine the locational PV hosting capacity. Feeder PV impact signature are used to more precisely determine the local maximum hosting capacity of individual areas of the feeder. T he feeder signature provides improved interconnection screening with certain zones that show the risk of impact to the distribution feeder from PV interconnections.

  16. Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Yang Guangming, E-mail: yangguangmingbs@126.com [Department of Resources and Environment, Baoshan University, Baoshan 678000 (China); Li Ling [Department of Resources and Environment, Baoshan University, Baoshan 678000 (China); Jiang Jinhe; Yang Yunhui [College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650092 (China)

    2012-08-01

    Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02 Multiplication-Sign 10{sup -7}-5.23 Multiplication-Sign 10{sup -4} mol L{sup -1} and 1.43 Multiplication-Sign 10{sup -7}-4.64 Multiplication-Sign 10{sup -4} mol L{sup -1}, the detection limits were 1.12 Multiplication-Sign 10{sup -8} mol L{sup -1} and 2.24 Multiplication-Sign 10{sup -8} mol L{sup -1}, respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. - Graphical abstract: The schematic diagram of formation of Au nanotube arrays (a) and the stepwise procedure of the sensor (b). Highlights: Black-Right-Pointing-Pointer Gold nanotubes array has been synthesized by cyclic voltammetry. Black-Right-Pointing-Pointer The mechanism of deposition of gold nanotube has been discussed. Black-Right-Pointing-Pointer A determination of ascorbic acid and uric acid was constructed by gold array. Black-Right-Pointing-Pointer A satisfied determination of samples can be obtained by this sensor.

  17. Biomass enzymatic saccharification is determined by the non-KOH-extractable wall polymer features that predominately affect cellulose crystallinity in corn.

    Science.gov (United States)

    Jia, Jun; Yu, Bin; Wu, Leiming; Wang, Hongwu; Wu, Zhiliang; Li, Ming; Huang, Pengyan; Feng, Shengqiu; Chen, Peng; Zheng, Yonglian; Peng, Liangcai

    2014-01-01

    Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at pbiomass saccharification after pretreatments with NaOH and H2SO4 at three concentrations. Notably, despite that the non-KOH-extractable residues covered 12%-23% hemicelluloses and lignin of total biomass, their wall polymer features exhibited the predominant effects on biomass enzymatic hydrolysis including Ara substitution degree of xylan (reverse Xyl/Ara) and S/G ratio of lignin. Furthermore, the non-KOH-extractable polymer features could significantly affect lignocellulose crystallinity at pbiomass digestibility. Hence, this study could suggest an optimal approach for genetic modification of plant cell walls in bioenergy corn.

  18. A prospective study comparing the functional impact of SIEA, DIEP, and muscle-sparing free TRAM flaps on the abdominal wall: part I. unilateral reconstruction.

    Science.gov (United States)

    Selber, Jesse C; Nelson, Jonas; Fosnot, Joshua; Goldstein, Jesse; Bergey, Meredith; Sonnad, Seema S; Serletti, Joseph M

    2010-10-01

    The purpose of this two-part study was to demonstrate the impact of free flap breast reconstruction on the abdominal wall. In Part I, the authors present the results for unilateral techniques. A blinded, prospective, cohort study was performed involving 234 free flap breast reconstruction patients. Patients were evaluated preoperatively, and followed for 1 year. At each encounter, patients underwent abdominal strength testing using the Upper and Lower Rectus Abdominis Manual Muscle Function Test, the Functional Independence Measure, and psychometric testing using the 36-Item Short-Form Health Survey. Patients also completed a satisfaction questionnaire specific to breast reconstruction. Statistical analysis included the Kruskal-Wallis, Mann-Whitney, Friedman, and Wilcoxon signed rank tests. Two-hundred thirty-four patients were enrolled. Of these, 157 underwent reconstruction (75 of which were unilateral), completed follow-up, and were included in the analysis. There was a significantly greater decline in upper abdominal strength in patients undergoing muscle-sparing free transverse rectus abdominis musculocutaneous (TRAM) flap surgery compared with deep inferior epigastric perforator (DIEP) flap surgery at early (p = 0.01) and late follow-up (p = 0.02). Unilateral superficial inferior epigastric artery flap procedures (n = 3) were too few for a meaningful conclusion to be reached. Lower abdominal and Functional Independence Measure scores showed no significant differences. Psychometric testing showed that there was a significant decline in physical health within the free TRAM flap group. No significant difference among groups was appreciable. In unilateral cases, the impact of the muscle-sparing free TRAM flap versus the DIEP flap follows theoretical predictions based on the degree of muscle sacrifice: the muscle-sparing free TRAM flap demonstrated a greater decline than the DIEP flap in certain measurable parameters.

  19. Illumina MiSeq sequencing reveals long-term impacts of single-walled carbon nanotubes on microbial communities of wastewater treatment systems.

    Science.gov (United States)

    Qu, Yuanyuan; Zhang, Xuwang; Shen, Wenli; Ma, Qiao; You, Shengnan; Pei, Xiaofang; Li, Shuzhen; Ma, Fang; Zhou, Jiti

    2016-07-01

    In this study, phenol wastewater treatment systems treated with different concentrations of single-walled carbon nanotubes (SWCNTs) (0-3.5g/L) were exposed to phenol and carbon nanotubes (CNTs) shock loadings to investigate the long-term impacts of SWCNTs on microbial communities. Phenol removal remained high efficiency (>98%) in SWCNTs-treated groups but decreased in non-treated group (85.1±1.9%) when exposed to high concentration of phenol (500mg/L). However, secondary dosing of SWCNTs in SWCNTs-treated groups would decrease the phenol removal efficiency. Illumina MiSeq sequencing revealed that the diversity, richness and structure of microbial communities were shifted under phenol shock loading, especially under high phenol concentration, but not under CNTs shock loading. In response to phenol and CNTs shock loadings, Rudaea, Burkholderia, Sphingomonas, Acinetobacter, Methylocystis and Thauera became dominant genera, which should be involved in phenol removal. These results suggested that a proper amount of SWCNTs might have positive effects on phenol wastewater treatment systems.

  20. Aluminum powder impacts the properties of EPS insulation energy-saving wall panel%铝粉对EPS节能保温墙板性能的影响

    Institute of Scientific and Technical Information of China (English)

    周鹏杰; 倪修全

    2013-01-01

    EPS节能保温墙板是一种轻型且保温效果好的保温材料,若在制作过程中加入铝粉,铝粉参与水化产生的氢氧化钙反应,生成氢气泡,使混凝土内部形成许多蜂窝状的结构,能增强保温效果。但当掺入过量铝粉时,发气量过大,墙体内部孔隙率过大,将影响混凝土的抗压强度,为此需要对铝粉的掺量进行研究。%EPS insulation energy-saving wall panels is a kind of light and heat preservation materials with good effect, if adding aluminum powder in the production process, Aluminum can react with the hydration of calcium hydroxide and generate hydrogen bubble, and form a number of cellular structure Inside the concrete, which enhances the heat preservation effect. When mixed with excess aluminum powder, it will have too much gas, and the large porosity impacts the compressive strength of concrete. So to study the content of aluminum powder is needed.

  1. Enhanced washout of {sup 99m}Tc-tetrofosmin in hypertrophic cardiomyopathy: quantitative comparisons with regional {sup 123}I-BMIPP uptake and wall thickness determined by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Thet-Thet-Lwin, Tohoru; Takeda, Jin; Wu, Yuko; Fumikura, Keiji; Iida, Satoru; Kawano, Iwao; Yamaguchi, Yuji; Itai [Institute of Clinical Medicine, University of Tsukuba, Tennodai 1-1-1, 305-8575, Tsukuba-shi, Ibaraki-ken (Japan)

    2003-07-01

    The diagnostic value of technetium-99m tetrofosmin (TF) washout in hypertrophic cardiomyopathy (HCM) was examined by investigating its relation to the metabolic abnormality depicted by iodine-123 {beta}-methyl-p-iodophenylpentadecanoic acid (BMIPP) uptake and the left ventricular (LV) myocardial wall thickness as measured by magnetic resonance imaging (MRI). TF washout was evaluated in 31 patients with HCM and 23 normal control subjects using 30-min (early) and 3-h (delayed) TF single-photon emission tomography images. The LV myocardial wall was divided into 19 segments and the percentage TF washout, regional BMIPP uptake and LV wall thickness were measured in each segment. Mean TF washout in the patients with HCM was significantly faster than that in normal control subjects (23.7{+-}5.7 vs 13.4{+-}4.1, P<0.0001). In the patients with HCM, TF washout showed an excellent correlation with MRI wall thickness (r=0.82, P<0.0001) and a good inverse correlation with regional BMIPP uptake (r=-0.72, P<0.0001). In addition, a good linear correlation was observed between TF uptake and MRI wall thickness in the 19 regional segments. In conclusion, the degree of TF washout corresponds well with the severity of myocardial wall thickness and the degree of metabolic abnormality in patients with HCM. These results suggest that enhanced TF washout might provide additional clinical information regarding metabolic alterations in HCM. (orig.)

  2. Space, composition, vertical wall ...

    OpenAIRE

    Despot, Katerina; Sandeva, Vaska

    2016-01-01

    The space in which it is an integral segment of our life is nourished with many functional and decorative elements. One aspect for consideration of vertical walls or The vertical gardens and their aesthetic impact in space called function. Vertical gardens bordering the decoration to totally functional garden in areas where there is little oxygen and space, ideal for residential buildings and public spaces where missing greenery, special place occupies in interior design where their expres...

  3. Using the thoughts on teen parenting survey to determine the impact of Wise Guys.

    Science.gov (United States)

    Herrman, Judith W; Moore, Christopher C; Sims, Regina

    2013-04-01

    The purpose of this project was to determine if the Wise Guys program influences young men's perceptions of the impact a teen birth would have on their lives in the areas of relationships, vocation, and personal life. The Wise Guys program was implemented with 70 adolescent males. The Thoughts on Teen Parenting Survey was used to determine participants' perceptions of the costs and rewards associated with teen parenting. Data, analyzed using paired t-tests, demonstrated that Wise Guys was effective in reinforcing less positive perceptions of teen parenting. Wise Guys offers an important strategy to impact young men's perceptions about the teen parenting experience and provides one means to promote responsible sexual behavior in teen men. © 2012, Wiley Periodicals, Inc.

  4. The Impact of Fiscal Policies on the Socioeconomic Determinants of Health: A Structured Review.

    Science.gov (United States)

    Mosquera, Isabel; González-Rábago, Yolanda; Bacigalupe, Amaia; Suhrcke, Marc

    2016-12-02

    There has been considerable recent debate around the alleged impact of discretionary fiscal policies - especially austerity policies - on health and health inequalities. Assuming that most of the impact will have to run via the effect of fiscal policies on socioeconomic determinants of health (SDH), it is of interest to gain a further understanding of the relationship between fiscal policies and SDH. Therefore, the aim of this article is to review the recent evidence on the impact of discretionary fiscal policies on key SDH, i.e. income, poverty, education, and employment, in high income OECD countries. We find that there are no simple answers as to how fiscal policy affects those determinants of health. The effects of contractionary and expansionary fiscal policies on the analyzed SDH vary considerably across countries and will largely depend on the pre-crisis situation. Contractionary fiscal policies seem to have increased poverty, while their impact on income inequality will be influenced by the composition of the implemented measures. More empirical research trying to directly link fiscal policies to health outcomes, while taking into account of some of the mechanisms encountered here, would be worthwhile.

  5. Determination of minimum impact parameter by modified touching spheres schemes for intermediate energy Coulomb excitation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajiv; Sharma, Shagun [DAV University, Physics Department, Jalandhar (India); Singh, Pradeep [Deenbandhu Chhotu Ram University of Science and Technology, Department of Physics, Murthal (India); Kharab, Rajesh [Kurukshetra University, Department of Physics, Kurukshetra (India)

    2016-02-15

    The energy-independent touching spheres schemes commonly used for the determination of the safe minimum value of the impact parameter for Coulomb excitation experiments are modified through the inclusion of an energy-dependent term. The touching spheres+3fm scheme after modification emerges out to be the best one while touching spheres+4fm scheme is found to be better in its unmodified form. (orig.)

  6. An electrochemical sensor prepared by sonochemical one-pot synthesis of multi-walled carbon nanotube-supported cobalt nanoparticles for the simultaneous determination of paracetamol and dopamine

    Energy Technology Data Exchange (ETDEWEB)

    Kutluay, Aysegul; Aslanoglu, Mehmet, E-mail: maslanoglu@harran.edu.tr

    2014-08-11

    Highlights: • A GCE was modified with carbon nanotubes and cobalt nanoparticles. • The composite material was obtained using an ultrasonic chemical deposition method. • The CoNPs/MWCNT/GCE was applied for the simultaneous determination of PAR and DA. • The presence of AA and UA did not affect the responses of PAR and DA. • Lower detection limits were obtained using the CoNPs/MWCNT/GCE. - Abstract: Multi-walled carbon nanotubes (MWCNTs) functionalized by cobalt nanoparticles were obtained using a single step chemical deposition method in an ultrasonic bath. The composite material was characterized using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The electroactivity of the cobalt-functionalized MWCNTs was assessed in respect to the electrooxidation of paracetamol (PAR) and dopamine (DA). It was found that the carbon nanotube supported cobalt nanoparticles have significantly higher catalytic properties. The proposed electrode has been applied for the simultaneous determination of PAR and DA. The modified electrode could resolve the overlapped voltammetric waves of PAR and DA into two well-defined voltammetric peaks with peak to peak separation of about 203 mV. On the other hand, the presence of potential drug interfering compounds AA and UA did not affect the voltammetric responses of PAR and DA. The current of oxidation peaks showed a linear dependent on the concentrations of PAR and DA in the range of 5.2 × 10{sup −9}–4.5 × 10{sup −7} M (R{sup 2} = 0.9987) and 5.0 × 10{sup −8}–3.0 × 10{sup −6} M (R{sup 2} = 0.9999), respectively. The detection limits of 1.0 × 10{sup −9} M and 1.5 × 10{sup −8} M were obtained for PAR and DA, respectively. The proposed electrode showed good stability (peak current change: 4.9% with and RSD of 2.6% for PAR; 5.5% with and RSD of 3.0% for DA over 3 weeks), reproducibility (RSD 2.3% for PAR and RSD 1.5% for DA), repeatability (RSD 2.25% for PAR and RSD 2.50% for DA) and

  7. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  8. CLIMBING WALL

    CERN Multimedia

    1999-01-01

    The FIRE AND RESCUE Group of TIS Commission informs that the climbing wall in the yard of the Fire-fighters Station, is intended for the sole use of the members of that service, and recalls that access to this installation is forbidden for safety reasons to all persons not belonging to the Service.CERN accepts no liability for damage or injury suffered as a result of failure to comply with this interdiction.TIS/DI

  9. Single-walled carbon nanotubes coated fibers for solid-phase microextraction and gas chromatography-mass spectrometric determination of pesticides in Tea samples.

    Science.gov (United States)

    Wu, Fang; Lu, Wanping; Chen, Jinghua; Liu, Wei; Zhang, Lan

    2010-08-15

    Using a single-walled carbon nanotubes (SWCNTs) as stationary phase of solid-phase microextraction (SPME) fibers, a simple, low cost and environmentally friendly method for extraction of 13 pesticides in Tea samples has been developed following gas chromatography-mass spectrometric determination. Potential factors affecting the extraction efficiency were investigated and optimized, including extraction and desorption time, extraction temperature, stirring rate, solution pH and ionic strength. Under optimized conditions, the linearity of the developed method was in the range of 0.125-25 ng/mL with correlation coefficients greater than 0.9928 and the limits of detections (LODs) were 0.027-0.23 ng/mL (S/N=3). Meanwhile, the relative standard deviations (RSDs) for five successive measurements with single fiber, fiber-to-fiber, day-to-day were 2.3-13.0, 8.2-14.6 and 4.1-12.5%, respectively, indicating good reproducibility of the proposed method. The fiber had high extraction efficiency for studied pesticides in comparison with commercial poly(dimethylsiloxane) (PDMS) and polyacrylate (PA) fibers and could be used for more than 70 times without decrease of efficiency. The developed method was successfully applied for the analysis of real samples including green Tea, oolong Tea, white Tea, and flower Tea, and the recoveries of the pesticides spiked in these samples ranged from 75.1 to 118.4%. Chlorfenapyr and lambda-cyhalothrin were found in the Tea samples bought randomly from local market. The results demonstrated that the developed SWCNTs-SPME method was a simple, efficient pretreatment and enrichment procedure for pesticides in complex matrices. Copyright 2010 Elsevier B.V. All rights reserved.

  10. The Cu-MOF-199/single-walled carbon nanotubes modified electrode for simultaneous determination of hydroquinone and catechol with extended linear ranges and lower detection limits

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jian [School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070 (China); Li, Xi, E-mail: chemlixi@whut.edu.cn [School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070 (China); Yang, Linlin; Yan, Songlin; Wang, Mengmeng; Cheng, Dan; Chen, Qi; Dong, Yulin; Liu, Peng; Cai, Weiquan [School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Chaocan, E-mail: polymers@whut.edu.cn [School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070 (China)

    2015-10-29

    A novel electrochemical sensor based on Cu-MOF-199 [Cu-MOF-199 = Cu{sub 3}(BTC){sub 2} (BTC = 1,3,5-benzenetricarboxylicacid)] and SWCNTs (single-walled carbon nanotubes) was fabricated for the simultaneous determination of hydroquinone (HQ) and catechol (CT). The modification procedure was carried out through casting SWCNTs on the bare glassy carbon electrode (GCE) and followed by the electrodeposition of Cu-MOF-199 on the SWCNTs modified electrode. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) were performed to characterize the electrochemical performance and surface characteristics of the as-prepared sensor. The composite electrode exhibited an excellent electrocatalytic activity with increased electrochemical signals towards the oxidation of HQ and CT, owing to the synergistic effect of SWCNTs and Cu-MOF-199. Under the optimized condition, the linear response range were from 0.1 to 1453 μmol L{sup −1} (R{sub HQ} = 0.9999) for HQ and 0.1–1150 μmol L{sup −1} (R{sub CT} = 0.9990) for CT. The detection limits for HQ and CT were as low as 0.08 and 0.1 μmol L{sup −1}, respectively. Moreover, the modified electrode presented the good reproducibility and the excellent anti-interference performance. The analytical performance of the developed sensor for the simultaneous detection of HQ and CT had been evaluated in practical samples with satisfying results. - Highlights: • Cu-MOF-199/SWCNTs/GCE was facilely fabricated by the electrodeposition on SWCNTs/GCE. • An electrochemical sensor for detecting HQ and CT was constructed based on this modified electrode. • The proposed electrochemical sensor showed an extended linear range and lower detection limits. • The proposed electrochemical sensor had an excellent stability and reproducibility.

  11. Discrimination and simultaneous determination of hydroquinone and catechol by tunable polymerization of imidazolium-based ionic liquid on multi-walled carbon nanotube surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xun; Gao, Weiwei; Zhou, Shenghai; Shi, Hongyan; Huang, Hao; Song, Wenbo, E-mail: wbsong@jlu.edu.cn

    2013-12-17

    Graphical abstract: -- Highlights: •Tunable free radical polymerization of ionic liquid on MWCNT surfaces. •Discrimination of hydroquinone and catechol at functional electrochemical interface. •Excellent performances in simultaneous determination based on cation-π interaction. -- Abstract: Tunable polymerization of ionic liquid on the surfaces of multi-walled carbon nanotubes (MWCNTs) was achieved by a mild thermal-initiation-free radical reaction of 3-ethy-1-vinylimidazolium tetrafluoroborate in the presence of MWCNTs. Successful modification of polymeric ionic liquid (PIL) on MWCNTs surfaces (PIL-MWCNTs) was demonstrated by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray photoelectron spectroscopy. The resulting PIL-MWCNTs possessed unique features of high dispersity in aqueous solution and tunable thickness of PIL layer, due to positive imidazole groups along PIL chains and controllable ionic liquid polymerization by tuning the ratio of precursor. Based on cation-π interaction between the positive imidazole groups on PIL-MWCNTs surface and hydroquinone (HQ) or catechol (CC), excellent discrimination ability toward HQ and CC and improved simultaneous detection performance were achieved. The linear range for HQ and CC were 1.0 × 10{sup −6} to 5.0 × 10{sup −4} M and 1.0 × 10{sup −6} to 4.0 × 10{sup −4} M, respectively. The detection limit for HQ was 4.0 × 10{sup −7} M and for CC 1.7 × 10{sup −7} M (S/N = 3), correspondingly.

  12. Restricted access magnetic core-mesoporous shell microspheres with C8-modified interior pore-walls for the determination of diazepam in rat plasma by LC-MS.

    Science.gov (United States)

    Liu, Xiaodan; Yu, Yingjia; Li, Yan; Ning, Suli; Liu, Tingting; Li, Fajie; Duan, Gengli

    2013-03-15

    In this study, a novel enrichment technique based on magnetic core-mesoporous shell microspheres with C8-modified interior pore-walls (C8-Fe₃O₄@mSiO₂) was successfully developed for the determination of diazepam in rat plasma by LC-MS. Due to the unique properties of the synthesized C8-Fe₃O₄@mSiO₂ microspheres (C8-modified magnetic mesoporous microsphere), small drug molecules like diazepam can enter the mesopore channels and be efficiently absorbed through hydrophobic interaction by interior C8-groups (Octyl functional groups). Large molecules like proteins are excluded from the mesopore channels as a result of size exclusion effect, leading to direct extraction of drug molecules from protein-rich biosmaples such as plasma without any other pretreatment procedure. Moreover, diazepam adsorbed C8-Fe₃O₄@mSiO₂ microspheres could be simply and rapidly isolated through placing a magnet on the bottom of container, and then diazepam could be easily eluted from C8-Fe₃O₄@mSiO₂ microspheres for further LC-MS analysis. Extraction conditions such as amounts of C8-Fe₃O₄@mSiO₂ microspheres added, adsorption time, elution solvent and elution time were investigated. Method validations including linear range, the limit of detection, precision, and recovery were also studied. The results indicated that the proposed method based on C8-Fe₃O₄@mSiO₂ microspheres was simple and accurate for the analysis of diazepam in the rat plasma. And it will provide new ideas for analyzing plasma concentration and pharmacokinetics of similar drugs.

  13. Determination of the Impact of Glycolate on ARP and MCU Operations

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, K. M.L.; Peters, T. B.; Fondeur, F. F.; Shehee, T. C.; Washington, A. L.

    2012-12-13

    Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal, phase separation, or coalescer performance at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU). Sorption testing was performed using both MST and modified MST (mMST) in the presence of 5000 and 10,000 ppm (mass basis) glycolate. 10,000 ppm is the estimated bounding concentration expected in the DWPF recycle stream based on DWPF melter flammable gas model results. The presence of glycolate was found to slow the removal of Sr and Pu by MST, while increasing the removal rate of Np. Results indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. There was no measurable effect on U removal at either glycolate concentration. The slower removal rates for Sr and Pu at 5000 and 10,000 ppm glycolate could result in lower DF values for these sorbates in ARP based on the current (12 hours) and proposed (8 hours) contact times. For the highest glycolate concentration used in this study, the percentage of Sr removed at 6 hours of contact decreased by 1% and the percentage of Pu removed decreased by nearly 7%. The impact may prove insignificant if the concentration of glycolate that is returned to the tank farm is well below the concentrations tested in this study. The presence of glycolate also decreased the removal rates for all three sorbates (Sr, Pu, and Np) by mMST. Similar to MST, the results for mMST indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. The

  14. An electrochemical sensor prepared by sonochemical one-pot synthesis of multi-walled carbon nanotube-supported cobalt nanoparticles for the simultaneous determination of paracetamol and dopamine.

    Science.gov (United States)

    Kutluay, Aysegul; Aslanoglu, Mehmet

    2014-08-11

    Multi-walled carbon nanotubes (MWCNTs) functionalized by cobalt nanoparticles were obtained using a single step chemical deposition method in an ultrasonic bath. The composite material was characterized using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The electroactivity of the cobalt-functionalized MWCNTs was assessed in respect to the electrooxidation of paracetamol (PAR) and dopamine (DA). It was found that the carbon nanotube supported cobalt nanoparticles have significantly higher catalytic properties. The proposed electrode has been applied for the simultaneous determination of PAR and DA. The modified electrode could resolve the overlapped voltammetric waves of PAR and DA into two well-defined voltammetric peaks with peak to peak separation of about 203 mV. On the other hand, the presence of potential drug interfering compounds AA and UA did not affect the voltammetric responses of PAR and DA. The current of oxidation peaks showed a linear dependent on the concentrations of PAR and DA in the range of 5.2×10(-9)-4.5×10(-7) M (R(2)=0.9987) and 5.0×10(-8)-3.0×10(-6) M (R(2)=0.9999), respectively. The detection limits of 1.0×10(-9) M and 1.5×10(-8) M were obtained for PAR and DA, respectively. The proposed electrode showed good stability (peak current change: 4.9% with and RSD of 2.6% for PAR; 5.5% with and RSD of 3.0% for DA over 3 weeks), reproducibility (RSD 2.3% for PAR and RSD 1.5% for DA), repeatability (RSD 2.25% for PAR and RSD 2.50% for DA) and high recovery (99.7% with an RSD of 1.3% for PAR; 100.8% with an RSD of 1.8% for DA). The proposed method was successfully applied to the determination of PAR and DA in pharmaceuticals. Copyright © 2014. Published by Elsevier B.V.

  15. Determining the Impact of Residential Neighbourhood Crime on Housing Investment Using Logistic Regression

    Directory of Open Access Journals (Sweden)

    Sunday Emmanuel Olajide

    2016-12-01

    Full Text Available This paper discusses the impact of criminal activities on residential property value. With regard to criminal activities, the paper emphasizes on the contribution of each component of property crime. One thousand (1000 sets of structured questionnaire were administered on the residents of residential estates within the South Western States of Nigeria out of which 467 were considered useable after the data screening. Purposive and systematic sampling techniques were used while logistic regression was used to determine the impact of each of the components of residential property crime on housing investment. The results showed the P-Values of 0.000, 0.322, 0.335, 0.545 and 0.992 for violent crime, incivilities and street crime, burglary and theft, vandalism and robbery respectively. However, the R2 which represents the generalisation of the impact of neighbourhood crime on housing investment was 44 % and aggregate P-value was 0.000. Using the Hosmer and Lemeshow (H-L test of goodness of fit, the model had approximately 89% predictive probability which is considered excellent. This indicates that the alternative hypothesis is upheld that residential neighbourhood crime is capable of impacting on residential property value. The policy implication of this result is that no effort should be spared in combating residential neighbourhood crime in order to boost and encourage housing investment.

  16. Determining the minimally important difference for the Oral Health Impact Profile-20.

    LENUS (Irish Health Repository)

    Allen, P Finbarr

    2009-04-01

    In the context of clinical trials, measurement of change is critical. The aim of this study was to determine the minimally important difference (MID) for the Oral Health Impact Profile-20 (OHIP-20) when used with partially dentate patients undergoing treatment that included the provision of removable partial dentures. In a prospective clinical trial, 51 consecutive patients were provided with removable partial dentures. In addition to demographic and dental status data, patients completed an OHIP-20 prior to treatment. One month postoperatively, patients completed a post-treatment OHIP-20 and a global transition scale. Domains assessed in the global transition scale were appearance, ability to chew food, oral comfort, and speech. The MID for the OHIP-20 was calculated using the anchor-based approach. From the initial sample of 51 patients, 44 completed post-treatment questionnaires and were included in the analysis. Change scores in the four transition domains indicated that new dentures had a positive impact in the majority of subjects, especially in perceived impact on chewing and appearance. The study provided a guideline as to what constitutes the MID for the OHIP-20. This benchmark can be used when interpreting the impact of clinical intervention for replacing missing teeth and for power calculation in statistical analyses.

  17. Prioritizing health: a systematic approach to scoping determinants in health impact assessment

    Directory of Open Access Journals (Sweden)

    Lindsay McCallum

    2016-08-01

    Full Text Available The determinants of health are those factors that have the potential to affect health, either positively or negatively, and include a range of personal, social, economic, and environmental factors. In the practice of Health Impact Assessment (HIA, the stage at which the determinants of health are considered for inclusion is during the scoping step. The scoping step is intended to identify how the HIA will be carried out and to set the boundaries (e.g., temporal and geographical for the assessment. There are several factors that can help to inform the scoping process, many of which are considered in existing HIA tools and guidance; however, a systematic method of prioritizing determinants was found to be lacking. In order to analyze existing HIA scoping tools that are available, a systematic literature review was conducted including both primary and grey literature. A total of 10 HIA Scoping tools met the inclusion/exclusion criteria and were carried forward for comparative analysis. The analysis focused on minimum elements and practice standards of HIA scoping that have been established in the field. The analysis determined that existing approaches lack a clear, systematic method of prioritization of health determinants for inclusion in HIA. This finding led to the development of a Systematic HIA Scoping tool that addressed this gap. The decision matrix tool uses factors such as impact, public concern and data availability to prioritize health determinants. Additionally, the tool allows for identification of data gaps and provides a transparent method for budget allocation and assessment planning. In order to increase efficiency and improve utility, the tool was programmed into Microsoft Excel. Future work in the area of HIA methodology development is vital to the ongoing success of the practice and utilization of HIA as a reliable decision-making tool.

  18. Bank Savings and Bank Credits in Nigeria: Determinants and Impact on Economic Growth

    Directory of Open Access Journals (Sweden)

    Orji Anthony

    2012-01-01

    Full Text Available This study investigated the determinants of bank savings in Nigeria as well as examined the impact of bank savings and bank credits on Nigeria’s economic growth from 1970-2006. We adopted two impact models; Distributed Lag-Error Correction Model (DL-ECM and Distributed Model. The empirical results showed a positive influence of values of GDP per capita (PCY, Financial Deepening (FSD, Interest Rate Spread (IRS and negative influence of Real Interest Rate (RIR and Inflation Rate (INFR on the size of private domestic savings. Also a positive relationship exists between the lagged values of total private savings, private sector credit, public sector credit, interest rate spread, exchange rates and economic growth. We therefore recommend, among others, that government’s effort should be geared towards improving per capita income by reducing the unemployment rate in the country in a bid to accelerate growth through enhanced savings.

  19. ROLE CONFLICT AND ROLE AMBIGUITY ON LOCAL GOVERNMENT INTERNAL AUDITORS: THE DETERMINANT AND IMPACTS

    Directory of Open Access Journals (Sweden)

    Agil Novriansa

    2016-01-01

    Full Text Available The bureaucratic reform at the local government level in Indonesia that was instituted in 2012 has turned local government internal auditors into an important part of government governance systems. The role of local government internal auditors has been expanded to include not only the area of audit oversight, but also the areas of anti-corruption-related and consulting activities. These fundamental changes may potentially induce role conflict and role ambiguity among internal auditors. The objective of this study is to examine empirically the determinants and consequences of role conflict and role ambiguity among local government internal auditors. More specifically, this study attempts to examine the extent to which formalization determines role conflict and role ambiguity; it further tests the impact of role conflict and role ambiguity on commitment to independence and job performance. Questionnaires were distributed to 248 local government internal auditors from 12 Regional Inspectorates in the provinces of Yogyakarta, South Sumatra, and East Java. A total of 176 responses were received, and 124 useable responses from the 176 responses were analysed to test the hypotheses. Using Structural Equation Modelling-Partial Least Square the results show that: formalization is negatively related to role conflict and role ambiguity; role ambiguity has a negative impact on commitment to independence; role conflict has a positive impact on job performance; and role ambiguity has a negative impact on job performance. These findings serve as important external validity evidence on the phenomena associated with role conflict and role ambiguity that occur in the public sector, especially among internal auditors at local government institutions.

  20. Determinants of health policy impact: comparative results of a European policymaker study.

    Science.gov (United States)

    Rütten, Alfred; Lüschen, Günther; von Lengerke, Thomas; Abel, Thomas; Kannas, Lasse; Rodríguez Diaz, Josep A; Vinck, Jan; van der Zee, Jouke

    2003-01-01

    This article will use a new theoretical framework for the analysis of health policy impact introduced by Rütten et al. (2003). In particular, it will report on a comparative European study of policymakers' perception and evaluation of specific determinants of the policy impact, both in terms of output (implemented measures) and outcome (health behaviour change). Policy determinants investigated are goals, resources, obligations and opportunities as related to the policymaking process. Theory is applied to a comparative analysis of prevention and health promotion policy in Belgium, Finland, Germany. The Netherlands, Spain and Switzerland. The study is MED2-part of a project that has developed a Methodology for the Analysis of the Rationality and Effectiveness of Prevention and Health Promotion Strategies (MAREPS) within the EU-BIO-program. A mail survey of 719 policymakers on the executive and administrative level selected by a focused sample procedure was conducted. This survey used policymakers' experience and evaluative expertise to analyse determinants of policy output and outcome. Regression analyses reveal differential predictive power of policy goals, resources, obligations, as well as of political, organisational and public opportunities. For instance, whereas resources, concreteness of goals, and public opportunities have significant importance for health outcome of policy, obligations and organisational opportunities significantly predict policy output. Results are discussed in terms of rationality and effectiveness of health policy. They indicate that six sensitising constructs derived from the theoretical framework represent equivalent structures across nations. They comprise a validated instrument that can be used for further comparative health policy research.

  1. [Useage of genetic markers to determine the impact of radiation on the human body].

    Science.gov (United States)

    Zedgenidze, A G; Namchevadze, E N; Nikuradze, T D; Zalinian, G G; Parsadanian, G G

    2015-02-01

    The timely determination of the fact of radiation impact on the organism is extremely important for preventive and curative interventions. Despite the fact that so far cytogenetic violations are considered to be the best biomarkers to determine the impact of ionizing radiation on the organism, actual problem is to find the optimal combination of different biomarkers. The aim of the work was investigation of the extended set of biomarkers in distant periods of exposure in people previously assigned to the radiation risk group, as well as the identification of genetic disorders in the process of radiotherapy. The object of the study were 37 residents of districts, where at the beginning of this century radioactive sources were discovered, and 6 oncology patients in the course of radiotherapy. Chromosome disorders, the overall level of DNA cells single-stranded damage by comet-assay method and a method of level detection of buccal micronuclei in were investigated. The results showed heterogeneity of different organism response to irradiation. Determination of absorbed dose, identification of various genetic disorders in individuals exposed to identical doses of radiation, offers the opportunity to judge the individual biological effect and is very important for individual preventive activities.

  2. Impact of photon cross section uncertainties on Monte Carlo-determined depth-dose distributions.

    Science.gov (United States)

    Aguirre, E; David, M; deAlmeida, C E; Bernal, M A

    2016-09-01

    This work studies the impact of systematic uncertainties associated to interaction cross sections on depth dose curves determined by Monte Carlo simulations. The corresponding sensitivity factors are quantified by changing cross sections by a given amount and determining the variation in the dose. The influence of total and partial photon cross sections is addressed. Partial cross sections for Compton and Rayleigh scattering, photo-electric effect, and pair production have been accounted for. The PENELOPE code was used in all simulations. It was found that photon cross section sensitivity factors depend on depth. In addition, they are positive and negative for depths below and above an equilibrium depth, respectively. At this depth, sensitivity factors are null. The equilibrium depths found in this work agree very well with the mean free path of the corresponding incident photon energy. Using the sensitivity factors reported here, it is possible to estimate the impact of photon cross section uncertainties on the uncertainty of Monte Carlo-determined depth dose curves.

  3. Genetic susceptibility of the arterial wall is an important determinant of atherosclerosis in C57BL/6 and FVB/N mouse strains

    DEFF Research Database (Denmark)

    Shim, Jeong; Handberg, Aase; Östergren, Eva-Britt Caroline

    2011-01-01

    How genetic variations among inbred mouse strains translate into differences in atherosclerosis susceptibility is of significant interest for the development of new therapeutic strategies. The objective of the present study was to examine whether genetically controlled arterial wall properties in...... influence atherosclerosis susceptibility in FVB/N (FVB) and C57BL/6 (B6) apolipoprotein E knockout (apoE(-/-)) mouse strains....

  4. Biomass Enzymatic Saccharification Is Determined by the Non-KOH-Extractable Wall Polymer Features That Predominately Affect Cellulose Crystallinity in Corn

    Science.gov (United States)

    Wu, Leiming; Wang, Hongwu; Wu, Zhiliang; Li, Ming; Huang, Pengyan; Feng, Shengqiu; Chen, Peng; Zheng, Yonglian; Peng, Liangcai

    2014-01-01

    Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at pbiomass saccharification after pretreatments with NaOH and H2SO4 at three concentrations. Notably, despite that the non-KOH-extractable residues covered 12%–23% hemicelluloses and lignin of total biomass, their wall polymer features exhibited the predominant effects on biomass enzymatic hydrolysis including Ara substitution degree of xylan (reverse Xyl/Ara) and S/G ratio of lignin. Furthermore, the non-KOH-extractable polymer features could significantly affect lignocellulose crystallinity at pbiomass digestibility. Hence, this study could suggest an optimal approach for genetic modification of plant cell walls in bioenergy corn. PMID:25251456

  5. The Valence of Self-Generated (Status Updates) and Other-Generated (Wall-Posts) Information Determines Impression Formation on Facebook.

    Science.gov (United States)

    Rosenthal-Stott, Harriet E S; Dicks, Rea E; Fielding, Lois S

    2015-01-01

    We examined whether self-generated (status updates) or other-generated (wall-posts) information on Facebook influenced the impression formed of the target individual. Along with examining reliance on particular types of information, we explored the valence (positive/ neutral/ negative) of the information, as reliance on self-generated or other-generated information may depend on whether self-presentation is perceived (i.e., presenting oneself positively / not negatively). Self-presentation may be perceived if the targets have positive/ neutral statuses, while negative statuses would indicate a lack of self-presentation. In line with previous research, participants should rely on other-generated information (wall-posts) to form an impression when participants are viewed to have self-presented (positive / neutral status updates), as this information could be viewed as unreliable. Forty participants rated nine Facebook profiles where statuses and wall-posts portrayed personality traits varying in valence. Each profile consisted of a neutral profile photo, three status updates (all positive, negative, or neutral) and three wall-posts (all positive, negative, or neutral). Materials were established in two pilots. Impression formation was measured as perceived social, task, and physical attractiveness of the target individual. Participants also ranked the profiles for likeability. Supporting our expectations, other-generated information (wall-posts) dominated impression formation for social attractiveness when self-generated information (status updates) was positive/ neutral. Task attractiveness was affected by information valence, regardless of source (self or other). Despite the inclusion of neutral photos, physical attractiveness was affected by self-generated information, with negative statuses lowering physical attractiveness. We suggest that these findings have implications for impression formation beyond the Facebook setting. The 557 traits analyzed in Pilot 1 are

  6. The Valence of Self-Generated (Status Updates and Other-Generated (Wall-Posts Information Determines Impression Formation on Facebook.

    Directory of Open Access Journals (Sweden)

    Harriet E S Rosenthal-Stott

    Full Text Available We examined whether self-generated (status updates or other-generated (wall-posts information on Facebook influenced the impression formed of the target individual. Along with examining reliance on particular types of information, we explored the valence (positive/ neutral/ negative of the information, as reliance on self-generated or other-generated information may depend on whether self-presentation is perceived (i.e., presenting oneself positively / not negatively. Self-presentation may be perceived if the targets have positive/ neutral statuses, while negative statuses would indicate a lack of self-presentation. In line with previous research, participants should rely on other-generated information (wall-posts to form an impression when participants are viewed to have self-presented (positive / neutral status updates, as this information could be viewed as unreliable. Forty participants rated nine Facebook profiles where statuses and wall-posts portrayed personality traits varying in valence. Each profile consisted of a neutral profile photo, three status updates (all positive, negative, or neutral and three wall-posts (all positive, negative, or neutral. Materials were established in two pilots. Impression formation was measured as perceived social, task, and physical attractiveness of the target individual. Participants also ranked the profiles for likeability. Supporting our expectations, other-generated information (wall-posts dominated impression formation for social attractiveness when self-generated information (status updates was positive/ neutral. Task attractiveness was affected by information valence, regardless of source (self or other. Despite the inclusion of neutral photos, physical attractiveness was affected by self-generated information, with negative statuses lowering physical attractiveness. We suggest that these findings have implications for impression formation beyond the Facebook setting. The 557 traits analyzed in

  7. The Valence of Self-Generated (Status Updates) and Other-Generated (Wall-Posts) Information Determines Impression Formation on Facebook

    Science.gov (United States)

    Rosenthal-Stott, Harriet E. S.; Dicks, Rea E.; Fielding, Lois S.

    2015-01-01

    We examined whether self-generated (status updates) or other-generated (wall-posts) information on Facebook influenced the impression formed of the target individual. Along with examining reliance on particular types of information, we explored the valence (positive/ neutral/ negative) of the information, as reliance on self-generated or other-generated information may depend on whether self-presentation is perceived (i.e., presenting oneself positively / not negatively). Self-presentation may be perceived if the targets have positive/ neutral statuses, while negative statuses would indicate a lack of self-presentation. In line with previous research, participants should rely on other-generated information (wall-posts) to form an impression when participants are viewed to have self-presented (positive / neutral status updates), as this information could be viewed as unreliable. Forty participants rated nine Facebook profiles where statuses and wall-posts portrayed personality traits varying in valence. Each profile consisted of a neutral profile photo, three status updates (all positive, negative, or neutral) and three wall-posts (all positive, negative, or neutral). Materials were established in two pilots. Impression formation was measured as perceived social, task, and physical attractiveness of the target individual. Participants also ranked the profiles for likeability. Supporting our expectations, other-generated information (wall-posts) dominated impression formation for social attractiveness when self-generated information (status updates) was positive/ neutral. Task attractiveness was affected by information valence, regardless of source (self or other). Despite the inclusion of neutral photos, physical attractiveness was affected by self-generated information, with negative statuses lowering physical attractiveness. We suggest that these findings have implications for impression formation beyond the Facebook setting. The 557 traits analyzed in Pilot 1 are

  8. Determining the Onset of Amorphization of Crystalline Silicon due to Hypervelocity Impact

    Science.gov (United States)

    Poletti, C. Shane; Bachlechner, Martina E.

    2009-03-01

    Atomistic simulations were performed to study a hypervelocity impactor striking a silicon/silicon nitride interface with varying silicon substrate thicknesses. Visualization indicates that the crystalline silicon amorphizes upon impact. The objective of the present study is to determine where the boundary between amorphous and crystalline silicon occurrs. In the analysis, the silicon substrate is separated into sixty layers and for each layer the average z displacement is determined. Our results show that the boundary between amorphous and crystalline silicon occurs between layers 20 and 22 for an impactor traveling at 5 km/s. This corresponds to a depth of approximately 32 Angstroms into the silicon. More detailed analyses reveals that the z displacement is noticeably larger for the layers that do not have a silicon atom bonded beneath them compared to the ones that do.

  9. Identifying new lignin bioengineering targets: impact of epicatechin, quercetin glycoside, and gallate derivatives on the lignification and fermentation of maize cell walls

    Science.gov (United States)

    Apoplastic targeting of secondary metabolites compatible with monolignol polymerization may provide new avenues for designing lignins that are less inhibitory toward fiber fermentation. To identify suitable monolignol substitutes, we artificially lignified maize cell walls with normal monolignols pl...

  10. A multi-walled carbon nanotube-modified glassy carbon electrode as a new sensor for the sensitive simultaneous determination of paracetamol and tramadol in pharmaceutical preparations and biological fluids

    OpenAIRE

    Babaei, Ali; Taheri,Ali Reza; Afrasiabi,Mohammad

    2011-01-01

    A chemically modified electrode was constructed based on a multi-walled carbon nanotube-modified glassy carbon electrode (MWCNTs/GCE). It was demonstrated that this sensor can be used for the simultaneous determination of the pharmaceutically important compounds paracetamol (PAR) and tramadol (TRA). The measurements were carried out by the application of differential pulse voltammetry (DPV), cyclic voltammetry (CV) and chronoamperometry (CA) methods. Application of the DPV method demonstrated...

  11. The impact and determinants of donor support in Cross River State - Nigeria

    Directory of Open Access Journals (Sweden)

    Christopher A. Otu

    2016-01-01

    Full Text Available This study examines the impact and determinants of donor support in Cross River State Nigeria by linking donor support program and economic growth in Cross River State, the impact of political, economic, corporate governance, and sound donor governance indicators on economic development indicator, and finally the impact economic governance indicators, corporate governance indicators, sound donor governance indicators, economic development indicator on flow of donor support indicator using a sample of 200 cross sectional respondents - government agencies, donor organizations, Non-Governmental Organizations (NGOs, and private individuals. I use a well validated structured questionnaire method for data collection and use Ordinary Least Squares (OLS and the Pearson Product Moment Correlation for analysis. The results show among others a positive relationship between flow of donor support and indicators of quality of political and economic governance, and quality of the business environment, there existed a significant relationship between donor support and economic growth in Cross River State. Based on the result, it was recommended that maintaining a safe and attractive business environment is critical for sustained inflow of donor funds. Equally, channeling donor funds to agro-allied industrialization, manufacturing, health, and tourism would enhance economic development. Lastly mechanisms for conflict prevention, management, and resolution at both state and local government levels should be encouraged so as to influence more funding activities to the state.

  12. Impact of the cameras radiometric resolution on the accuracy of determining spectral reflectance coefficients

    Science.gov (United States)

    Orych, A.; Walczykowski, P.; Jenerowicz, A.; Zdunek, Z.

    2014-11-01

    Nowadays remote sensing plays a very important role in many different study fields, i.e. environmental studies, hydrology, mineralogy, ecosystem studies, etc. One of the key areas of remote sensing applications is water quality monitoring. Understanding and monitoring of the water quality parameters and detecting different water contaminants is an important issue in water management and protection of whole environment and especially the water ecosystem. There are many remote sensing methods to monitor water quality and detect water pollutants. One of the most widely used method for substance detection with remote sensing techniques is based on usage of spectral reflectance coefficients. They are usually acquired using discrete methods such as spectrometric measurements. These however can be very time consuming, therefore image-based methods are used more and more often. In order to work out the proper methodology of obtaining spectral reflectance coefficients from hyperspectral and multispectral images, it is necessary to verify the impact of cameras radiometric resolution on the accuracy of determination of them. This paper presents laboratory experiments that were conducted using two monochromatic XEVA video sensors (400-1700 nm spectral data registration) with two different radiometric resolutions (12 and 14 bits). In view of determining spectral characteristics from images, the research team used set of interferometric filters. All data collected with multispectral digital video cameras were compared with spectral reflectance coefficients obtained with spectroradiometer. The objective of this research is to find the impact of cameras radiometric resolution on reflectance values in chosen wavelength. The main topic of this study is the analysis of accuracy of spectral coefficients from sensors with different radiometric resolution. By comparing values collected from images acquired with XEVA sensors and with the curves obtained with spectroradiometer it

  13. Space Systems - Safety and Compatibility of Materials - Method to Determine the Ignition Susceptibility of Materials or Components to Particle Impact

    Science.gov (United States)

    Hirsch, David B.

    2011-01-01

    The scope of this International Technical Specification is to provide a method to determine the ignition susceptibility of materials and components to particle impact. The method can be used to determine the conditions at which ignition and consumption of a specimen material occurs when impacted by single or multiple particles entrained in a flow of gaseous oxygen (GOX). Alternatively, the method can be used to determine if a specific material or component is subject to ignition and sustained combustion in a given flow environment when impacted by single or multiple particles entrained in a flow of GOX.

  14. The impact of the combined chimney outlet size and extended solar wall-roof chimney on airflow patterns using numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    AboulNaga, M.M.; Alteraifi, A.M.

    1999-07-01

    This paper investigates airflow patterns and behavior of combined roof and extended solar wall-roof chimney incorporated into a typical room with an inlet and outlet. Numerical simulations using the Fluid Dynamics software Package, FIDAP, are exploited to describe and analyze the airflow patterns inside the room, and in the extended solar wall-roof chimneys. FIDAP simulation analyses and results of the airflow streamline, velocity vectors, and temperature distributions are presented. Maximum velocity vector, temperatures, and smooth streamlines were found for better performance at separation of 0.25m. At 0.25m separation, in both wall and roof solar chimneys, the maximum chimney outlet flow rate and smooth streamline were found when the wall chimney is 2.00m high, which corresponds to a wall chimney inlet of 1.60m. Results show that the maximum relative speed in the combined chimneys is higher than the solar roof chimney alone. These findings suggest that the exploitation of an extended solar roof-wall chimney could enhance nighttime natural ventilation and the cooling of buildings. The system is limited to cool low-rise buildings in hot-arid regions such as Al-Ain City, UAE, where energy use is enormous.

  15. 3D photon impact determination in monolithic crystals based on autocorrelation filters and RTP methods

    Energy Technology Data Exchange (ETDEWEB)

    Conde, Pablo; Gonzalez, Antonio [Institute for Instrumentation in Molecular Imaging, I3M-CSIC, Valencia (Spain); Bettiol, Marco; Fabbri, Andrea; Pani, Roberto [Department of Molecular Medicine, Sapienza University of Rome (Italy); Benlloch Baviera, José María; Talens Aguilar, Albert; Hernandez, Liczandro; Sanchez, Filomeno [Institute for Instrumentation in Molecular Imaging, I3M-CSIC, Valencia (Spain)

    2015-05-18

    In PET detectors based on monolithic scintillators, the photon impact position can be estimated from the light intensity distribution (LD) on the photodetector pixels. Typically, there is a poor estimation of the interaction positions towards the edges when linear algorithms such as Center of Gravity (CoG) are used. We present a novel method to determine the interaction coordinates in thick monolithic crystals filtering the digitized LDs from each gamma-event by means of an autocorrelation filter and the raise to power (RTP) positioning algorithm to reduce the border effects. The experimental setup was based on two detector blocks based on monolithic LYSO scintillator crystals (50x50x20 mm{sup 3}). Each crystal is coupled to a SiPMs array as 12x12 photosensors and an electronic readout that outputs information of each SiPM row and column. Between the detector blocks, a collimated array of 9x9 {sup 22}Na sources, separated 5 mm each other, was placed. The optimum power to use in the RTP positioning algorithm was determined using the third order intercept point (IP3) from plots of the measured coordinates versus known positions. After applying the autocorrelation and RTP fifth to the data, we found an improvement of the spatial resolution from 2.5 mm when CoG is used, to 1.2 mm in the crystal center region. In this work we show how to accurately resolve 3D photon impact coordinates in thick monolithic crystals using autocorrelation filters merged with RTP methods. After applying the new approach it is possible to accurately resolve impacts close to the entrance of 20 mm thick LYSO scintillators. The reached spatial resolution at any photon depth of interaction is comparable with state-of-the-art crystal array approaches with the advantage of the proposed work to also provide continuous depth of interaction information.

  16. Growth and trends in publications about abdominal wall hernias and the impact of a specific journal on herniology: a bibliometric analysis.

    Science.gov (United States)

    Kulacoglu, H; Oztuna, D

    2011-12-01

    The aim of this systematic review was to determine the exact volume and growth pattern of articles on abdominal wall hernias, in particular the effect of the journal Hernia on publications about hernias. A PubMed search was performed for every year between 1965 and 2010, using the title words "inguinal hernia," "incisional hernia," and "umbilical hernia." Then, two consecutive 10-year periods were chosen for a systematic PubMed search, before and after 2001--the year in which Hernia began to be indexed in PubMed. The main keywords used were as follows: "inguinal hernia" "incisional hernia" "umbilical hernia" "mesh" "laparoscopic" and "experimental." The number of all articles indexed in PubMed increased 1.6-fold between the periods 1991-2000 and 2001-2010. The number of articles with the title word "inguinal hernia" increased 1.7-fold, whereas the rises for incisional and umbilical hernias were more prominent: 3.9- and 2.6-fold. Article titles with the combined keywords "hernia and mesh" and "hernia and laparoscopic" increased 2.8- and 2.4-fold. The most striking combined search was for "umbilical hernia and mesh" with a 20.5-fold rise. The percentage of articles published in the journal Hernia among all articles in all 25 selected journals, including Hernia was 30% on average. Hernia, Surgical Endoscopy and the British Journal of Surgery were the leading journals for publications for inguinal hernia in the last decade. Growth in hernia papers is greater than the overall growth in PubMed. Articles on incisional hernia increased faster than did those on inguinal and umbilical hernias. The establishment and indexing of Hernia decreased the proportion of hernia publications in other journals. The core journals for herniology are Hernia, Surgical Endoscopy, and the British Journal of Surgery.

  17. Green towers and green walls

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture and Planning, Vancouver, BC (Canada)

    2006-07-01

    North American cities face many major environmental and health issues such as urban heat island effect, the intensity of storms, microclimate around buildings, imperviousness of sites, poor air quality and increases in respiratory disease. Several new technologies are starting to address global impacts and community level issues as well as the personal health and comfort of building occupants. These include green towers, living walls, vegetated rooftops and ecological site developments. This paper examined these forms of eco-development and presented their benefits. It discussed green walls in Japan; green towers in Malaysia, Singapore and Great Britain; green facades of climbing plants; active living walls in Canada; and passive living walls in France and Canada. It also discussed thermal walls; thematic walls; vertical gardens and structured wildlife habitat. Last, it presented testing, monitoring, research and conclusions. The Centre for the Advancement of Green Roof Technology is setting up a program to test thermal performance, to assess plant survival and to monitor green walls at the British Columbia Institute of Technology in Vancouver, Canada as much of the research out of Japan is only available in Japanese script. It was concluded that green architecture can provide shade, food, rainwater, shelter for wildlife and mimic natural systems. 15 refs.

  18. Determining

    Directory of Open Access Journals (Sweden)

    Bahram Andarzian

    2015-06-01

    Full Text Available Wheat production in the south of Khuzestan, Iran is constrained by heat stress for late sowing dates. For optimization of yield, sowing at the appropriate time to fit the cultivar maturity length and growing season is critical. Crop models could be used to determine optimum sowing window for a locality. The objectives of this study were to evaluate the Cropping System Model (CSM-CERES-Wheat for its ability to simulate growth, development, grain yield of wheat in the tropical regions of Iran, and to study the impact of different sowing dates on wheat performance. The genetic coefficients of cultivar Chamran were calibrated for the CSM-CERES-Wheat model and crop model performance was evaluated with experimental data. Wheat cultivar Chamran was sown on different dates, ranging from 5 November to 9 January during 5 years of field experiments that were conducted in the Khuzestan province, Iran, under full and deficit irrigation conditions. The model was run for 8 sowing dates starting on 25 October and repeated every 10 days until 5 January using long-term historical weather data from the Ahvaz, Behbehan, Dezful and Izeh locations. The seasonal analysis program of DSSAT was used to determine the optimum sowing window for different locations as well. Evaluation with the experimental data showed that performance of the model was reasonable as indicated by fairly accurate simulation of crop phenology, biomass accumulation and grain yield against measured data. The normalized RMSE were 3%, 2%, 11.8%, and 3.4% for anthesis date, maturity date, grain yield and biomass, respectively. Optimum sowing window was different among locations. It was opened and closed on 5 November and 5 December for Ahvaz; 5 November and 15 December for Behbehan and Dezful;and 1 November and 15 December for Izeh, respectively. CERES-Wheat model could be used as a tool to evaluate the effect of sowing date on wheat performance in Khuzestan conditions. Further model evaluations

  19. Impact Analysis of Window-Wall Ratio on Heating and Cooling Energy Consumption of Residential Buildings in Hot Summer and Cold Winter Zone in China

    Directory of Open Access Journals (Sweden)

    Qiaoxia Yang

    2015-01-01

    Full Text Available In order to assess the optimal window-wall ratio and the proper glazing type in different air conditioning system operation modes of residential buildings for each orientation in three typical cities in hot summer and cold winter zone: Chongqing, Shanghai, and Wuhan simulation models were built and analyzed using Designer’s Simulation Toolkit (DeST. The study analyzed the variation of annual heating energy demand, annual cooling energy demand, and the annual total energy consumption in different conditions, including different orientations, patterns of utilization of air conditioning system, window-wall ratio, and types of windows. The results show that the total energy consumption increased when the window-wall ratio is also increased. It appears more obvious when the window orientation is east or west. Furthermore, in terms of energy efficiency, low-emissivity (Low-E glass performs better than hollow glass. From this study, it can be concluded that the influence and sensitivity of window-wall ratio on the total energy consumption are related to the operation mode of air conditioning system, the orientation of outside window, and the glazing types of window. The influence of the factors can be regarded as reference mode for the window-wall ratio when designing residential buildings.

  20. Falling walls

    CERN Multimedia

    It was 20 years ago this week that the Berlin wall was opened for the first time since its construction began in 1961. Although the signs of a thaw had been in the air for some time, few predicted the speed of the change that would ensue. As members of the scientific community, we can take a moment to reflect on the role our field played in bringing East and West together. CERN’s collaboration with the East, primarily through links with the Joint Institute for Nuclear Research, JINR, in Dubna, Russia, is well documented. Less well known, however, is the role CERN played in bringing the scientists of East and West Germany together. As the Iron curtain was going up, particle physicists on both sides were already creating the conditions that would allow it to be torn down. Cold war historian Thomas Stange tells the story in his 2002 CERN Courier article. It was my privilege to be in Berlin on Monday, the anniversary of the wall’s opening, to take part in a conference entitled &lsquo...

  1. "Great Ideas" in Russian Psychology: Personality Impact on Psychophysiological Functions and Causal Approach to Self- determination

    Directory of Open Access Journals (Sweden)

    Irina A. Mironenko

    2009-01-01

    Full Text Available Russian psychology has brought into the world science at least two great ideas: the conditioned reflex (Pavlov and the zone of proximal development (Vygotsky. These concepts were formulated before “iron curtain” fell. Since then Russian science dropped out from the view of western colleagues for decades. Now it is challenged to re-join international mainstream. Are we in a position to contribute?A key concept for Russian psychology is personality impact on psycho-physiological functions and causal approach to self-determination. The concept of selfdetermination appeared in Western theories in 1980-es and since then it has been developed in the context of teleological humanitarian approach. In Russian science the concept of self-determination dates back to 1934, when it was defined by Rubinstein as “sub’ekt”. Self-determination of ontogenesis of psycho physiological functions resulting from confluence of ontogenesis and social development was explicated by Russian scientists whose theoretical reasoning and empirical results are compared to Western counterparts.

  2. OTVE combustor wall condition monitoring

    Science.gov (United States)

    Szemenyei, Brian; Nelson, Robert S.; Barkhoudarian, S.

    1989-01-01

    Conventional ultrasonics, eddy current, and electromagnetic acoustic transduction (EMAT) technologies were evaluated to determine their capability of measuring wall thickness/wear of individual cooling channels in test specimens simulating conditions in the throat region of an OTVE combustion chamber liner. Quantitative results are presented for the eddy current technology, which was shown to measure up to the optimum 20-mil wall thickness with near single channel resolution. Additional results demonstrate the capability of the conventional ultrasonics and EMAT technologies to detect a thinning or cracked wall. Recommendations for additional eddy current and EMAT development tests are presented.

  3. Determination and analysis on solar radiation of trapezoidal soil wall and soil surface in solar greenhouse%日光温室土质梯形墙体与地表太阳辐射测定分析

    Institute of Scientific and Technical Information of China (English)

    张亚红; 白青; 封美琦; 孙利鑫

    2013-01-01

    with the walls and grounds respectively. That is to say, the probes at the wall were set inclined, while horizontal at the ground. Then, solar radiation was determined at the inner back wall’s upper, middle and lower parts, and also at the ground’s northern and southern parts. The radiation on the wall surface was determined by setting inclined and horizontal probes, and then the two groups of figures were analyzed. The results showed that the solar radiation determined by the two methods was strikingly different: the radiation quantity determined by setting inclined probes was much higher than that of horizontal probes. The quantity determined by inclined method was the actual solar radiation the wall ground received. Under the condition of closed tuyere, the results showed that:1) Wall:the daily average solar radiation intensity at the back wall increased successively at the upper, middle and lower parts. On clear days, the total radiation at the three parts was 5.74, 9.70, and 11.08 MJ/m2 respectively, accounting for 21.6%, 36.6%, and 41.8%respectively of the total daily solar radiation. On cloudy days, the total radiation at the three parts were 0.99, 1.50, and 1.92 MJ/m2 respectively, accounting for 22.5%, 34.0%, and 43.5%of the total daily solar radiation. 2) Ground:the total solar radiation in the southern part was always higher than that in northern part. On sunny days, the total radiation at the two parts was 11.00 and 6.74 MJ/m2, accounting for 62.0%and 38.0% respectively of the total ground radiation. On cloudy days, the radiation at the two parts was 3.51 and 2.04 MJ/m2, accounting for 63.2% and 36.8% respectively of the total ground radiation. 3) Wall and ground: the total solar radiation measured along the ground was higher than that measured along the wall. On sunny days, the mean wall radiation was 8.117 MJ/m2 and the ground radiation averaged 8.280 MJ/m2. Therefore, the ground radiation was slightly higher than the wall radiation, but the

  4. Acetylation of cell wall is required for structural integrity of the leaf surface and exerts a global impact on plant stress responses

    DEFF Research Database (Denmark)

    Nafisi, Majse; Stranne, Maria; Fimognari, Lorenzo;

    2015-01-01

    The epidermis on leaves protects plants from pathogen invasion and provides a waterproof barrier. It consists of a layer of cells that is surrounded by thick cell walls, which are partially impregnated by highly hydrophobic cuticular components. We show that the Arabidopsis T-DNA insertion mutants...... to abiotic stress, particularly detoxification of reactive oxygen species and defense against microbial pathogens (e.g., lipid transfer proteins, peroxidases). In accordance, peroxidase activities were found to be elevated in rwa2 as compared to the wild type. These results indicate that cell wall...... acetylation is essential for maintaining the structural integrity of leaf epidermis, and that reduction of cell wall acetylation leads to global stress responses in Arabidopsis....

  5. 铝球弹丸高速斜撞击铝Whipple防护结构时后板的损伤特性%Damage Characteristics of Rear Walls of Aluminum Whipple Shields by Oblique Hypervelocity Impact of Aluminum Spheres

    Institute of Scientific and Technical Information of China (English)

    管公顺; 哈跃; 庞宝君

    2012-01-01

    In order to simulate and study the oblique hypervelocity impacts of space debris on bumper of spacecrafts,a series of oblique hypervelocity impact experiments of aluminum Whipple shields are car- ried out by a two-stage light gas gun. The aluminum alloy projectile diameter is 3.97 mm, the impact velocities range from 1.14 to 5.35 km/s,and the impact angles range from 0° to 70°. The crater distributions on the rear wall of aluminum Whipple shield obliquely impacted by aluminum spheres are obtained and analyzed. In addition, the forecast equations for crater distribution on the rear wall of aluminum Whipple shield by oblique hyperveloeity impact are derived. The results indicate that there are two crater distribution areas on the rear wall under hypervelocity oblique impact. The critical fragmen- tation velocity of projectile will bring effect on the relationship between the impact damage law of rear wall and impact angle. For aluminum alloy Whipple shield,there exists a critical initial collision angle at which the impact damage on the rear wall is the most severe.%为了研究空间碎片对航天器防护结构的高速斜撞击损伤特性,采用二级轻气炮发射铝球弹丸,对铝Whipple防护结构进行高速斜撞击实验。弹丸直径为3.97mm,撞击速度为1.14~5.35km/s,撞击角度为0°~70°。实验得到了铝Whipple防护结构在不同撞击速度区间的后板损伤模式,分析了后板撞击损伤及弹坑分布特性,建立了预测铝球弹丸高速斜撞击铝Whipple防护结构时后板弹坑分布的经验公式。结果表明:在大角度斜撞击条件下,对于一定的撞击速度,铝Whipple防护结构的后板弹坑分布会出现两个区域;弹丸的撞击破碎临界速度将影响后板损伤随撞击角的变化关系;对于铝Whipple防护结构,存在使后板撞击损伤最严重的临界撞击角。

  6. The use of instrumented mobile laboratories to determine gaseous pollutant impacts

    Energy Technology Data Exchange (ETDEWEB)

    Cunnigham, J.E.

    1983-06-01

    Mobile sampling laboratories have been used by the Texas Air Control Board (TACB) to detect and measure the gaseous pollutant impacts from point sources. Mobile sampling enables one to locate zones of relatively high levels of air contaminants and take measurements for any desirable time period. Two types of measurements can be made. The first type is the determination of plume cross-section concentration profile. These measurements are taken while driving the van at a constant speed on a road perpendicular to the direction of plume transport. The second type of measurement is a stationary sample made by monitoring the pollutant concentrations for some time period with the van located at one point. A plume cross-section measurement is made to locate the local point of maximum concentration where stationary sampling may be done most efficaciously.

  7. Relationship between determinant factors of disclosure of information on environmental impacts of Brazilian companies

    Directory of Open Access Journals (Sweden)

    Mara Vogt

    2017-01-01

    Full Text Available This study aims at analyzing the relationship between determinant factors of disclosure of information on environmental impacts of Brazilian companies. A descriptive, documental and quantitative research was conducted through a sample of 97 Brazilian companies. In the Sustainability Reports and in the Annual Reports information, five environmental aspects were collected: emissions, effluents, wastes, products and services; and transport, which were used to measure the degree of environmental disclosure. This concludes that there is a relationship between the variables investigated in all analyzed years. The size, audit and Global Reporting Initiative (GRI are associated with disclosure and the Corporate Sustainability Index (CSI, Pollution Potential (POTEN, governance, stocks, Return on Assets (ROA and Return on Equity (ROE are not.

  8. Determining the inventory impact of extended-shelf-life platelets with a network simulation model.

    Science.gov (United States)

    Blake, John T

    2017-09-06

    The regulatory shelf life for platelets (PLTs) in many jurisdictions is 5 days. PLT shelf life can be extended to 7 days with an enhanced bacterial detection algorithm. Enhanced testing, however, comes at a cost, which may be offset by reductions in wastage due to longer shelf life. This article describes a method for estimating systemwide reductions in PLT outdates after PLT shelf life is extended. A simulation was used to evaluate the impact of an extended PLT shelf life within a national blood network. A network model of the Canadian Blood Services PLT supply chain was built and validated. PLT shelf life was extended from 5 days to 6, 7, and 8 days and runs were completed to determine the impact on outdates. Results suggest that, in general, a 16.3% reduction in PLT wastage can be expected with each additional day that PLT shelf life is extended. Both suppliers and hospitals will experience fewer outdating units, but wastage will decrease at a faster rate at hospitals. No effect was seen by blood group, but there was some evidence that supplier site characteristics influences both the number of units wasted and the site's ability to benefit from extended-shelf-life PLTs. Extended-shelf-life PLTs will reduce wastage within a blood supply chain. At 7 days, an improvement of 38% reduction in wastage can be expected with outdates being equally distributed between suppliers and hospital customers. © 2017 AABB.

  9. The impact of the LHC Z-boson transverse momentum data on PDF determinations

    Science.gov (United States)

    Boughezal, Radja; Guffanti, Alberto; Petriello, Frank; Ubiali, Maria

    2017-07-01

    The LHC has recently released precise measurements of the transverse momentum distribution of the Z-boson that provide a unique constraint on the structure of the proton. Theoretical developments now allow the prediction of these observables through next-to-next-to-leading order (NNLO) in perturbative QCD. In this work we study the impact of incorporating these latest advances into a determination of parton distribution functions (PDFs) through NNLO including the recent ATLAS and CMS 7 TeV and 8 TeV p T Z data. We investigate the consistency of these measurements in a global fit to the available data and quantify the impact of including the p T Z distributions on the PDFs. The inclusion of these new data sets significantly reduces the uncertainties on select parton distributions and the corresponding parton-parton luminosities. In particular, we find that the p T Z data ultimately leads to a reduction of the PDF uncertainty on the gluon-fusion and vector-boson fusion Higgs production cross sections by about 30%, while keeping the central values nearly unchanged.

  10. Exploring the impact of determining factors behind CO2 emissions in China: A CGE appraisal.

    Science.gov (United States)

    Xiao, Bowen; Niu, Dongxiao; Wu, Han

    2017-03-01

    Along with the arrival of the post-Kyoto Protocol era, the Chinese government faces ever greater pressure to reduce greenhouse gases (GHGs). Hence, this paper aims to discuss the drivers of carbon dioxide (CO2) emissions and their impact on society as a whole. First, we analyzed the background and overall situations of CO2 emissions in China. Then, we reviewed previous studies to explore the determinants behind China's CO2 emissions. It is widely acknowledged that energy efficiency, energy mix, and economy structure are three key factors contributing to CO2 emissions. To explore the impacts of those three factors on the economy and CO2 emissions, we established a computable general equilibrium (CGE) model. The following results were found: (1) The decline of a secondary industry can cause an emission reduction effect, but this is at the expense of the gross domestic product (GDP), whereas the development of a tertiary industry can boost the economy and help to reduce CO2 emissions. (2) Cutting coal consumption can contribute significantly to emission reduction, which is accompanied by a great loss in the whole economy. (3) Although the energy efficiency improvement plays a positive role in promoting economic development, a backfire effect can weaken the effects of emission reduction and energy savings.

  11. A Research to Determining the Impact of 360 Degree Performance Evaluation System on Organizational Commitment

    Directory of Open Access Journals (Sweden)

    Gulten Eren Gumustekin

    2010-01-01

    Full Text Available This study tries to find out whether the 360 degree performance evaluation system (PES has an influence on employees in terms of organizational commitment. Then it attempts to determine direction of the impact on commitment. In more detail, the study focuses on the eight key competencies acknowledged by the 360 Degree PES and their respective impacts on organizational commitment dimensions namely affective, continuance and normative. To this end, four different organizations were targeted for the survey which was developed to collect attitudinal information relevant to dimensions of organizational commitment and to key competences defined by 360 degree PES. The results mainly show that the businesses which implement 360 degree PES are more likely to have high levels of organizational commitment. The findings indicate an important degree of positive correlation between key competencies and commitment dimensions. The most influential competency on commitment appears to be communication which is followed by leadership, task management, employee development, adaptability to change, training others, human relations and production/work outputs.

  12. Fandom and the fourth wall

    Directory of Open Access Journals (Sweden)

    Jenna Kathryn Ballinger

    2014-09-01

    Full Text Available I use the Teen Wolf fandom as an example to examine the ways social media has created a more complicated, nuanced relationship with fans. The collapse of the fourth wall between fans and The Powers That Be can have both positive and negative impacts, depending on the willingness of participants to maintain mutual respect and engage in meaningful dialogue.

  13. Wall to Wall Optimal Transport

    CERN Document Server

    Hassanzadeh, Pedram; Doering, Charles R

    2013-01-01

    The calculus of variations is employed to find steady divergence-free velocity fields that maximize transport of a tracer between two parallel walls held at fixed concentration for one of two constraints on flow strength: a fixed value of the kinetic energy or a fixed value of the enstrophy. The optimizing flows consist of an array of (convection) cells of a particular aspect ratio Gamma. We solve the nonlinear Euler-Lagrange equations analytically for weak flows and numerically (and via matched asymptotic analysis in the fixed energy case) for strong flows. We report the results in terms of the Nusselt number Nu, a dimensionless measure of the tracer transport, as a function of the Peclet number Pe, a dimensionless measure of the energy or enstrophy of the flow. For both constraints the maximum transport Nu_{MAX}(Pe) is realized in cells of decreasing aspect ratio Gamma_{opt}(Pe) as Pe increases. For the fixed energy problem, Nu_{MAX} \\sim Pe and Gamma_{opt} \\sim Pe^{-1/2}, while for the fixed enstrophy scen...

  14. Determining the Subcellular Location of Synthesis and Assembly of the Cell Wall Polysaccharide (1,3; 1,4)-β-d-Glucan in Grasses[OPEN

    Science.gov (United States)

    Wilson, Sarah M.; Ho, Yin Ying; Lampugnani, Edwin R.; Van de Meene, Allison M.L.; Bain, Melissa P.; Bacic, Antony; Doblin, Monika S.

    2015-01-01

    The current dogma for cell wall polysaccharide biosynthesis is that cellulose (and callose) is synthesized at the plasma membrane (PM), whereas matrix phase polysaccharides are assembled in the Golgi apparatus. We provide evidence that (1,3;1,4)-β-d-glucan (mixed-linkage glucan [MLG]) does not conform to this paradigm. We show in various grass (Poaceae) species that MLG-specific antibody labeling is present in the wall but absent over Golgi, suggesting it is assembled at the PM. Antibodies to the MLG synthases, cellulose synthase-like F6 (CSLF6) and CSLH1, located CSLF6 to the endoplasmic reticulum, Golgi, secretory vesicles, and the PM and CSLH1 to the same locations apart from the PM. This pattern was recreated upon expression of VENUS-tagged barley (Hordeum vulgare) CSLF6 and CSLH1 in Nicotiana benthamiana leaves and, consistent with our biochemical analyses of native grass tissues, shown to be catalytically active with CSLF6 and CSLH1 in PM-enriched and PM-depleted membrane fractions, respectively. These data support a PM location for the synthesis of MLG by CSLF6, the predominant enzymatically active isoform. A model is proposed to guide future experimental approaches to dissect the molecular mechanism(s) of MLG assembly. PMID:25770111

  15. Simulation of Contrast Agent Transport in Arteries with Multilayer Arterial Wall: Impact of Arterial Transmural Transport on the Bolus Delay and Dispersion

    Directory of Open Access Journals (Sweden)

    Min Xu

    2014-01-01

    Full Text Available One assumption of DSC-MRI is that the injected contrast agent is kept totally intravascular and the arterial wall is impermeable to contrast agent. The assumption is unreal for such small contrast agent as Gd-DTPA can leak into the arterial wall. To investigate whether the unreal assumption is valid for the estimation of the delay and dispersion of the contrast agent bolus, we simulated flow and Gd-DTPA transport in a model with multilayer arterial wall and analyzed the bolus delay and dispersion qualified by mean vascular transit time (MVTT and the variance of the vascular transport function. Factors that may affect Gd-DTPA transport hence the delay and dispersion were further investigated, such as integrity of endothelium and disturbed flow. The results revealed that arterial transmural transport would slightly affect MVTT and moderately increase the variance. In addition, although the integrity of endothelium can significantly affect the accumulation of contrast agent in the arterial wall, it had small effects on the bolus delay and dispersion. However, the disturbed flow would significantly increase both MVTT and the variance. In conclusion, arterial transmural transport may have a small effect on the bolus delay and dispersion when compared to the flow pattern in the artery.

  16. Determining the Impact of Steady-State PV Fault Current Injections on Distribution Protection

    Energy Technology Data Exchange (ETDEWEB)

    Seuss, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grijalva, Santiago [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    This report investigates the fault current contribution from a single large PV system and the impact it has on existing distribution overcurrent protection devices. Assumptions are made about the modeling of the PV system under fault to perform exhaustive steady - state fault analyses throughout distribution feeder models. Each PV interconnection location is tested to determine how the size of the PV system affects the fault current measured by each protection device. This data is then searched for logical conditions that indicate whether a protection device has operated in a manner that will cause more customer outages due to the addition of the PV system. This is referred to as a protection issue , and there are four unique types of issues that have been identified in the study. The PV system size at which any issues occur are recorded to determine the feeder's PV hosting capacity limitations due to interference with protection settings. The analysis is carried out on six feeder models. The report concludes with a discussion of the prevalence and cause of each protection issue caused by PV system fault current.

  17. Determination of the Impact of Urbanization on Agricultural Lands using Multi-temporal Satellite Sensor Images

    Science.gov (United States)

    Kaya, S.; Alganci, U.; Sertel, E.; Ustundag, B.

    2015-12-01

    Throughout the history, agricultural activities have been performed close to urban areas. Main reason behind this phenomenon is the need of fast marketing of the agricultural production to urban residents and financial provision. Thus, using the areas nearby cities for agricultural activities brings out advantage of easy transportation of productions and fast marketing. For decades, heavy migration to cities has directly and negatively affected natural grasslands, forests and agricultural lands. This pressure has caused agricultural lands to be changed into urban areas. Dense urbanization causes increase in impervious surfaces, heat islands and many other problems in addition to destruction of agricultural lands. Considering the negative impacts of urbanization on agricultural lands and natural resources, a periodic monitoring of these changes becomes indisputably important. At this point, satellite images are known to be good data sources for land cover / use change monitoring with their fast data acquisition, large area coverages and temporal resolution properties. Classification of the satellite images provides thematic the land cover / use maps of the earth surface and changes can be determined with GIS based analysis multi-temporal maps. In this study, effects of heavy urbanization over agricultural lands in Istanbul, metropolitan city of Turkey, were investigated with use of multi-temporal Landsat TM satellite images acquired between 1984 and 2011. Images were geometrically registered to each other and classified using supervised maximum likelihood classification algorithm. Resulting thematic maps were exported to GIS environment and destructed agricultural lands by urbanization were determined using spatial analysis.

  18. Detection of Anomalies in Diaphragm Walls

    NARCIS (Netherlands)

    Spruit, R.; Van Tol, F.; Broere, W.

    2015-01-01

    If a calamity with a retaining wall occurs, the impact on surrounding buildings and infrastructure is at least an order of magnitude more severe than without the calamity. In 2005 and 2006 major leaks in the retaining walls of underground stations in Amsterdam and Rotterdam occurred. After these cas

  19. Final Report for "Stabilization of resistive wall modes using moving metal walls"

    Energy Technology Data Exchange (ETDEWEB)

    Forest, Cary B.

    2014-02-05

    The UW experiment used a linear pinch experiment to study the stabilization of MHD by moving metal walls. The methodology of the experiment had three steps. (1) Identify and understand the no-wall MHD instability limits and character, (2) identify and understand the thin-wall MHD instabilities (re- sistive wall mode), and then (3) add the spinning wall and understand its impact on stability properties. During the duration of the grant we accomplished all 3 of these goals, discovered new physics, and completed the experiment as proposed.

  20. Multiple interaction types determine the impact of ant predation of caterpillars in a forest community.

    Science.gov (United States)

    Clark, Robert E; Farkas, Timothy E; Lichter-Marck, Isaac; Johnson, Emily R; Singer, Michael S

    2016-12-01

    Direct and indirect effects of predators are highly variable in complex communities, and understanding the sources of this variation is a research priority in community ecology. Recent evidence indicates that herbivore community structure is a primary determinant of predation strength and its cascading impacts on plants. In this study, we use variation in herbivore community structure among plant species to experimentally test two hypotheses in a temperate forest food web. First, variation in the strength of predator effects, such as ant predation of caterpillars, is predicted to be density dependent, exhibiting stronger effects when prey abundance is high (density-dependent predation hypothesis). Second, mutualistic interactions between ants and sap-feeding herbivores are expected to increase the abundance of predatory ants, strengthening predation effects on herbivores with cascading effects on host plants (keystone mutualism hypothesis). Using a large-scale predator exclusion experiment across eight dominant tree species, we tracked changes in insect density on 862 plants across two years, recording 2,322 ants, 1,062 sap-feeders, 5,322 caterpillars, and quantifying herbivory on 199, 338 leaves. In this experiment, density-dependent predation did not explain variation in the direct or indirect effects of ants on caterpillars and herbivory. In partial support of the keystone mutualism hypothesis, sap-feeders strengthened top-down effects of ants on caterpillars under some conditions. However, stronger ant predation of caterpillars did not lead to measurable trophic cascades on trees occupied by sap-feeders. Instead, the presence of sap-feeders was associated with increased per capita feeding damage by caterpillars, and this bottom-up effect attenuated the indirect effects of ants on host plants. These findings demonstrate that examining the multi-trophic impacts of mutualisms and predation in the context of the broader community can reveal patterns otherwise

  1. A multi-residue method for the determination of pesticides in tea using multi-walled carbon nanotubes as a dispersive solid phase extraction absorbent.

    Science.gov (United States)

    Hou, Xue; Lei, Shaorong; Qiu, Shiting; Guo, Lingan; Yi, Shengguo; Liu, Wei

    2014-06-15

    A modified QuEChERS (quick, easy, cheap, effective, rugged and safe) method using multi-walled carbon nanotubes (MWCNTs) as a dispersive solid phase extraction (d-SPE) absorbent was established for analysis of 78 pesticide residues in tea. A 6 mg MWCNT sample was selected as the optimised amount based on the distribution of pesticide recoveries and clean-up efficiency from 6 mL acetonitrile extracts. The matrix effects of the method were evaluated and matrix-matched calibration was recommended. The method was validated employing gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) at the spiked concentration levels of 0.05, 0.1 and 0.15 mg kg(-1). For most of the targeted pesticides, the percent recoveries range from 70% to 120%, with relative standard deviations (RSDs) absorbent with excellent cleanup efficiency, which could be widely applied for the analysis of pesticide residues.

  2. Determination of power-law attenuation coefficient and dispersion spectra in multi-wall carbon nanotube composites using Kramers-Kronig relations.

    Science.gov (United States)

    Mobley, Joel; Mack, Richard A; Gladden, Joseph R; Mantena, P Raju

    2009-07-01

    Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths investigated and up (>0.2 mm). Using Kramers-Kronig relations, the attenuation and dispersion data were found to be consistent with a power-law attenuation model with a range of exponents from y=1.12 to y=1.19 over the measurement bandwidth. The attenuation coefficients of the respective samples are found to decrease with increasing MWCNT content and a similar trend holds also for the dispersion. In contrast, the mean phase velocities for the samples rise with increasing MWCNT content indicating an increase in the mechanical moduli.

  3. 高压水射流冲击刚壁压力分布规律研究%Experimental Research of Impact Force Distribution on Rigid Wall by High Pressure Waterjet

    Institute of Scientific and Technical Information of China (English)

    刘智谋; 毛桂庭; 柯熠; 欧阳邓培

    2016-01-01

    为了探讨高压纯水射流和高压磨料射流冲击刚壁时射流冲击压力的分布规律,利用建立的专用测力工作台,研究了射流方向与刚壁成90°角时冲击压力的分布规律及靶距、系统工作压力对冲击压力的影响,并对磨料射流的强化效果进行了分析。结果表明:射流冲击力随径向距离的增加急速降低,是一非单调递减阶梯函数,连接各阶中心冲击力值,可视其为具非单调负指数下降规律。在靶距不变的情况下,纯水射流和磨料射流,其中心(最高压力)位置的冲击压力和系统压力呈正相关。%For exploring the distribution of impact force on rigid wall by pure waterjet and abrasive jet, the distribution of impact force with waterjet cutting angle at a 90° angle to the rigid wall, and effects on the impact force by the distance of nozzle from the rigid wall and water pressure available for the waterjet system were all tested with a specific force⁃measurement table, and the intensifying effect achieved by abrasive jetting was also analyzed. It is found that impact force of waterjet decreases rapidly with the increasing of radial distance, as a non⁃monotonically decreasing step function, connecting the central position of workbench and following a non⁃monotonic negative exponential decreasing rule. With the same distance between the nozzle and rigid wall for both pure waterjet and abrasive jet, the central position ( with the highest pressure) correlates positively with the system pressure.

  4. When direct health-care professional communications have an impact on inappropriate and unsafe use of medicines : A retrospective analysis of determinants of impact of safety warnings

    NARCIS (Netherlands)

    Reber, K.C.; Piening, S.; Wieringa, J.E.; Straus, S.M.J.M.; Raine, J.M.; de Graeff, Pauline; Haaijer-Ruskamp, F.M.; Mol, P.G.

    2013-01-01

    Serious safety issues relating to drugs are communicated to health-care professionals via Direct Health-Care Professional Communications (DHPCs). We explored which characteristics determined the impact of DHPCs issued in the Netherlands for ambulatory-care drugs (2001-2008). With multiple linear reg

  5. When direct health-care professional communications have an impact on inappropriate and unsafe use of medicines : A retrospective analysis of determinants of impact of safety warnings

    NARCIS (Netherlands)

    Reber, K.C.; Piening, S.; Wieringa, J.E.; Straus, S.M.J.M.; Raine, J.M.; de Graeff, Pauline; Haaijer-Ruskamp, F.M.; Mol, Peter G. M.

    Serious safety issues relating to drugs are communicated to health-care professionals via Direct Health-Care Professional Communications (DHPCs). We explored which characteristics determined the impact of DHPCs issued in the Netherlands for ambulatory-care drugs (2001-2008). With multiple linear

  6. Acetylation of cell wall is required for structural integrity of the leaf surface and exerts a global impact on plant stress responses

    DEFF Research Database (Denmark)

    Nafisi, Majse; Stranne, Maria; Fimognari, Lorenzo;

    2015-01-01

    -dense deposits. A large number of trichomes were collapsed and surface permeability of the leaves was enhanced in rwa2 as compared to the wild type. A massive reprogramming of the transcriptome was observed in rwa2 as compared to the wild type, including a coordinated up-regulation of genes involved in responses...... acetylation is essential for maintaining the structural integrity of leaf epidermis, and that reduction of cell wall acetylation leads to global stress responses in Arabidopsis....

  7. A pilot study of the impact of high-frequency chest wall oscillation in chronic obstructive pulmonary disease patients with mucus hypersecretion

    OpenAIRE

    Chakravorty I; Chahal K; Austin G

    2011-01-01

    Indranil Chakravorty1, Kamaljit Chahal2, Gillian Austin21St George's Hospital, London, 2East and North Hertfordshire NHS Trust, Lister Hospital and Primary Care Trust, Stevenage, Hertfordshire, UKIntroduction: Chronic obstructive pulmonary disease (COPD) patients with mucus hypersecretion tend to demonstrate increased frequency of infective exacerbations and a steeper slope of decline in lung function. Enhanced mucociliary clearance with high-frequency chest wall oscillation (HFCWO) d...

  8. Directly observed therapy of tuberculosis in Brazil: associated determinants and impact on treatment outcome.

    Science.gov (United States)

    Reis-Santos, B; Pellacani-Posses, I; Macedo, L R; Golub, J E; Riley, L W; Maciel, E L

    2015-10-01

    All Brazilian states. To assess the determinants of tuberculosis (TB) in patients undergoing directly observed therapy (DOT) and the impact of DOT on treatment outcomes. This is a cross-sectional study among TB patients aged ⩾18 years conducted in 2011. The primary outcome was the status of DOT received, while the secondary was the outcome of anti-tuberculosis treatment. In 2011, 35 775 (38.3%) subjects received DOT. The odds of receiving DOT were higher in patients with the following characteristics: brown/mestizo patients (OR 1.18, 95%CI 1.14-1.22) and those of other ethnic groups (OR 2.01, 95%CI 1.79-2.27) compared to Whites, alcohol users (OR 1.37, 95%CI 1.28-1.47) and those with mental disorders (OR 1.88, 95%CI 1.54-2.29). The odds of receiving DOT were lower in human immunodeficiency virus positive patients (OR 0.64, 95%CI 0.60-0.68). Patients who did not receive DOT were more likely to default from anti-tuberculosis treatment (OR 0.62, 95%CI 0.57-0.66), die due to TB (OR 0.68, 95%CI 0.61-0.77) and to have unknown treatment outcomes (OR 0.71, 95%CI 0.66-0.76). The adjusted preventable fraction of DOT in the reduction of unfavorable outcomes was 25%. Sociodemographic and clinical characteristics are determinants of anti-tuberculosis treatment outcomes in patients undergoing DOT; DOT use led to a 25% reduction in unfavorable outcomes.

  9. Structural and biochemical changes induced by pulsed electric field treatments on Cabernet Sauvignon grape berry skins: impact on cell wall total tannins and polysaccharides.

    Science.gov (United States)

    Cholet, Céline; Delsart, Cristèle; Petrel, Mélina; Gontier, Etienne; Grimi, Nabil; L'hyvernay, Annie; Ghidossi, Remy; Vorobiev, Eugène; Mietton-Peuchot, Martine; Gény, Laurence

    2014-04-02

    Pulsed electric field (PEF) treatment is an emerging technology that is arousing increasing interest in vinification processes for its ability to enhance polyphenol extraction performance. The aim of this study was to investigate the effects of PEF treatment on grape skin histocytological structures and on the organization of skin cell wall polysaccharides and tannins, which, until now, have been little investigated. This study relates to the effects of two PEF treatments on harvested Cabernet Sauvignon berries: PEF1 (medium strength (4 kV/cm); short duration (1 ms)) and PEF2 (low intensity (0.7 kV/cm); longer duration (200 ms)). Histocytological observations and the study of levels of polysaccharidic fractions and total amounts of tannins allowed differentiation between the two treatments. Whereas PEF1 had little effect on the polyphenol structure and pectic fraction, PEF2 profoundly modified the organization of skin cell walls. Depending on the PEF parameters, cell wall structure was differently affected, providing variable performance in terms of polyphenol extraction and wine quality.

  10. Differences in water depth determine leaf-litter decomposition in streams: implications on impact assessment reliability

    Directory of Open Access Journals (Sweden)

    Martínez A.

    2016-01-01

    Full Text Available Leaf-litter decomposition is a widespread functional indicator to assess the stream ecosystem status. However, the spatial location of leaf-bags could distort the impact assessment since intrinsic features of a given site have an important role in the spatial distribution of macroinvertebrates, which could affect decomposition rate. A source of variability that can be easily controlled is the water depth at which bags are incubated in stream bed. Therefore, we tested if water depth within a same mesohabitat (riffles can determine decomposition rates. Due to the seasonal variability of macroinvertebrate assemblages in temperate regions, the study was performed in autumn-winter and spring to test the consistency of the findings. In three streams from North of Spain 15 mesh bags with alder leaves were placed in riffles covering a gradient of depths. Depth had a positive effect on decomposition rates and biomass of associated total invertebrates and shredders in autumn-winter, fauna variables helping to explain the differences in rates. In spring, depth affected negatively rates, the observed variability being weakly explained by invertebrates, which did not show differences along depth. Despite the opposite trend between seasons, water depth influences the decomposition rates, which may reduce or increase differences among systems if the water depth distribution is greatly biased. Our study highlights the importance of covering a similar range of water depths in the different systems being compared.

  11. Impact and determinants of nurse turnover: a pan-Canadian study.

    Science.gov (United States)

    O'Brien-Pallas, Linda; Murphy, Gail Tomblin; Shamian, Judith; Li, Xiaoqiang; Hayes, Laureen J

    2010-11-01

    As part of a large study of nursing turnover in Canadian hospitals, the present study focuses on the impact and key determinants of nurse turnover and implications for management strategies in nursing units. Nursing turnover is an issue of ever-increasing priority as work-related stress and job dissatisfaction are influencing nurses' intention to leave their positions. Data sources included the nurse survey, unit managers, medical records and human resources databases. A broad sample of hospitals was represented with nine different types of nursing units included. Nurses turnover is a major problem in Canadian hospitals with a mean turnover rate of 19.9%. Higher levels of role ambiguity and role conflict were associated with higher turnover rates. Increased role conflict and higher turnover rates were associated with deteriorated mental health. Higher turnover rates were associated with lower job satisfaction. Higher turnover rate and higher level of role ambiguity were associated with an increased likelihood of medical error. Managing turnover within nursing units is critical to high-quality patient care. A supportive practice setting in which role responsibilities are understood by all members of the caregiver team would promote nurse retention. Stable nurse staffing and adequate managerial support are essential to promote job satisfaction and high-quality patient care. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

  12. Determining the Impact of Training on Teacher Use for a Web-to-Database System

    Directory of Open Access Journals (Sweden)

    Ray Fenton

    2001-04-01

    Full Text Available When instituting a web-based curriculum or assessment delivery system, how important is face-to-face teacher training? This study uses objective data and teacher survey responses to determine the impact of face-to-face training on a teacher’s Internet use of Alaska Health Online, a health education website. Approximately 80 teachers were randomly assigned to two groups, with one group receiving three days of training in the use of the website, and the other group having full access to the website, but no training. A third group consisted of “volunteers” who responded to a call to use the website. Objective data was automatically collected through web server “log files” which tracked a teacher user’s activities on the site. Completion of a 90-item survey by participants contributed a second source of data. Results show a significant difference between the training and no-training groups, with teachers in the training group visiting the site more frequently than their counterparts, and applying materials from the site to their classes more often.

  13. ON WALL SHEAR STRESS OF ARTERY

    Institute of Scientific and Technical Information of China (English)

    Liu Zhao-rong; Liu Bao-yu; Qin Kai-rong

    2003-01-01

    In this paper, a method was proposed that the wall shear stress of artery could be determined by measuring the centerline axial velocity and radial motion of arterial wall simultaneously.The method is simple in application and can get higher precision when it is used to determine the shear stress of arterial wall in vivo.As an example, the shear stress distribution in periodic oscillatory flow of human carotid was calculated and discussed.The computed results show that the shear stress distribution at any given instant is almost uniform and will be zero at the centerline and tends to maximum at the vessel wall.

  14. Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management

    Science.gov (United States)

    Evans, Thomas; Kumschick, Sabrina; Dyer, Ellie; Blackburn, Tim

    2014-01-01

    Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self-sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions. PMID:25165531

  15. Simultaneous trace-levels determination of Hg(II) and Pb(II) ions in various samples using a modified carbon paste electrode based on multi-walled carbon nanotubes and a new synthesized Schiff base

    Energy Technology Data Exchange (ETDEWEB)

    Afkhami, Abbas, E-mail: afkhami@basu.ac.ir [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Bagheri, Hasan [Department of Chemistry, Takestan Branch, Islamic Azad University, Takestan (Iran, Islamic Republic of); Khoshsafar, Hosein [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Saber-Tehrani, Mohammad [Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Tabatabaee, Masoumeh [Department of Chemistry, Yazd Branch, Islamic Azad University, Yazd (Iran, Islamic Republic of); Shirzadmehr, Ali [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2012-10-09

    Highlights: Black-Right-Pointing-Pointer A new chemically modified carbon paste electrode was constructed and used. Black-Right-Pointing-Pointer A new Schiff base and multi-walled carbon nanotube was used as a modifier. Black-Right-Pointing-Pointer The electrochemical properties of the modified electrode were studied. Black-Right-Pointing-Pointer The electrode was used to the simultaneous determination of Pb{sup 2+} and Hg{sup 2+}. - Abstract: A modified carbon paste electrode based on multi-walled carbon nanotubes (MWCNTs) and 3-(4-methoxybenzylideneamino)-2-thioxothiazolodin-4-one as a new synthesized Schiff base was constructed for the simultaneous determination of trace amounts of Hg(II) and Pb(II) by square wave anodic stripping voltammetry. The modified electrode showed an excellent selectivity and stability for Hg(II) and Pb(II) determinations and for accelerated electron transfer between the electrode and the analytes. The electrochemical properties and applications of the modified electrode were studied. Operational parameters such as pH, deposition potential and deposition time were optimized for the purpose of determination of traces of metal ions at pH 3.0. Under optimal conditions the limits of detection, based on three times the background noise, were 9.0 Multiplication-Sign 10{sup -4} and 6.0 Multiplication-Sign 10{sup -4} {mu}mol L{sup -1} for Hg(II) and Pb(II) with a 90 s preconcentration, respectively. In addition, the modified electrode displayed a good reproducibility and selectivity, making it suitable for the simultaneous determination of Hg(II) and Pb(II) in real samples such as sea water, waste water, tobacco, marine and human teeth samples.

  16. Evaluation of the solid-phase microextraction fiber coated with single walled carbon nanotubes for the determination of benzene, toluene, ethylbenzene, xylenes in aqueous samples.

    Science.gov (United States)

    Li, Quanlong; Ma, Xiaoxia; Yuan, Dongxing; Chen, Jinsheng

    2010-04-09

    A solid-phase microextraction (SPME) fiber coated with single walled carbon nanotubes (SWCNTs) was prepared by electrophoretic deposition and treated at 500 degrees C in H(2) stream. In order to evaluate the characteristics of the obtained fiber, it was applied in the headspace solid-phase microextraction (HS-SPME) of benzene, toluene, ethylbenzene and xylenes (BTEX) from water sample and quantification by gas chromatography with flame ionization detection (GC-FID). The results indicated that the thermal treatment with H(2) enhanced the extraction of the SWCNTs fiber for BTEX significantly. Thermal stability and durability of the fiber were also investigated, showing excellent stability up to 350 degrees C and life time over 120 times. In the comparison with the commercial CAR-PDMS fiber, the SWCNTs fiber showed similar and higher extraction efficiencies for BTEX. Under the optimized conditions, the linearity, LODs (S/N=3) and LOQs (S/N=10) of the method based on the SWCNTs fiber were 0.5-50.0, 0.005-0.026 and 0.017-0.088 microg/L, respectively. Repeatability for one fiber (n=3) was in the range of 1.5-5.6% and fiber-to-fiber reproducibility (n=3) was in the range of 4.2-8.3%. The proposed method was successfully applied in the analysis of BTEX compounds in seawater, tap water and wastewater from a paint plant.

  17. Short-distance charmonium correlator on the lattice with M\\"obius domain-wall fermion and a determination of charm quark mass

    CERN Document Server

    Nakayama, Katsumasa; Hashimoto, Shoji

    2016-01-01

    We calculate charmonium correlators on the lattice with 2+1-flavors of sea quarks and charm valence quark both described by the M\\"obius domain-wall fermion. Temporal moments of the correlators are calculated and matched to perturbative QCD formulae to extract the charm quark mass $m_c(\\mu)$ and strong coupling constant $\\alpha_s(\\mu)$. Lattice data at three lattice spacings, 0.044, 0.055, and 0.080~fm, are extrapolated to the continuum limit. The correlators in the vector channel are confirmed to be consistent with the experimental data for $e^+e^-\\to c\\bar{c}$, while the pseudo-scalar channel is used to extract $m_c(\\mu)$ and $\\alpha_s(\\mu)$. We obtain $m_\\mathrm{c}(3 \\mathrm{\\ GeV})$ = 1.003(8)~GeV and $\\alpha_s^{\\bar{\\mathrm{MS}}(4)}(3\\mathrm{\\ GeV})$ = 0.253(12). Dominant source of the error is the truncation of perturbative expansion at $\\alpha_s^3$.

  18. Determination of Acreage Thermal Protection Foam Loss From Ice and Foam Impacts

    Science.gov (United States)

    Carney, Kelly S.; Lawrence, Charles

    2015-01-01

    A parametric study was conducted to establish Thermal Protection System (TPS) loss from foam and ice impact conditions similar to what might occur on the Space Launch System. This study was based upon the large amount of testing and analysis that was conducted with both ice and foam debris impacts on TPS acreage foam for the Space Shuttle Project External Tank. Test verified material models and modeling techniques that resulted from Space Shuttle related testing were utilized for this parametric study. Parameters varied include projectile mass, impact velocity and impact angle (5 degree and 10 degree impacts). The amount of TPS acreage foam loss as a result of the various impact conditions is presented.

  19. Comparison on heat flux deposition between carbon and tungsten wall – Investigations on energy recycling

    Energy Technology Data Exchange (ETDEWEB)

    Bufferand, H., E-mail: hugo.bufferand@cea.fr [CEA, IRFM, 13108 St Paul-Lez-Durance (France); Bucalossi, J.; Ciraolo, G.; Fedorczak, N. [CEA, IRFM, 13108 St Paul-Lez-Durance (France); Genesio, P. [PIIM, CNRS, Aix-Marseille Université, 13397 Marseille (France); Ghendrih, Ph.; Gunn, J. [CEA, IRFM, 13108 St Paul-Lez-Durance (France); Marandet, Y.; Martin, C.; Mellet, N. [PIIM, CNRS, Aix-Marseille Université, 13397 Marseille (France); Serre, E. [M2P2, CNRS, Aix-Marseille Université, 13451 Marseille (France); Tamain, P. [CEA, IRFM, 13108 St Paul-Lez-Durance (France)

    2015-08-15

    The influence of the plasma facing components material on the scrape-off layer plasma is investigated. In particular, the energy recycling is found to be more pronounced for tungsten wall compared with carbon wall. Edge plasma simulations performed with the transport code SOLEDGE2D-EIRENE show that this enhanced energy recycling in the tungsten case leads to an increase of the scrape-off layer temperature. Moreover, the energy recycling depends on the ion angle of incidence with the wall. A PIC code has been used to model the ion acceleration in the magnetic pre-sheath and determine the later angle of incidence. These simulations show that ions mostly impact the wall with rather shallow incident angles leading to a further increase of the energy recycling.

  20. Development of a soil test for determining the impact of soil disturbance

    Science.gov (United States)

    United States Federal law requires land-managing agencies like the US Army to identify and take into account the impacts of their undertakings on archaeological resources. Development of a method that uses changes in the stratification of horizon interfaces to identify the onset of adverse impacts t...

  1. Variation in cell wall composition among forage maize (Zea mays L.) inbred lines and its impact on digestibility: analysis of neutral detergent fiber composition by pyrolysis-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Fontaine, Anne-Sophie; Bout, Siobhán; Barrière, Yves; Vermerris, Wilfred

    2003-12-31

    Cell wall digestibility is an important determinant of forage quality, but the relationship between cell wall composition and digestibility is poorly understood. We analyzed the neutral detergent fiber (NDF) fraction of nine maize inbred lines and one brown midrib3 mutant with pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). Among 29 pyrolysis fragments that were quantified, two carbohydrate-derived and six lignin-derived fragments showed statistically significant genetic variation. The pyrolysis products 4-vinyl phenol and 2,6-dimethoxy-4-vinyl phenol were negatively correlated with digestibility, whereas furfural and 3-(4-hydroxyphenyl)-3-oxopropanal showed a positive correlation with digestibility. Linear discriminant analysis of the pyrolysis data resulted in the resolution of groups of inbred lines with different digestibility properties based on their chemical composition. These analyses reveal that digestibility is governed by complex interactions between different cell wall compounds, but that several pyrolysis fragments can be used as markers to distinguish between maize lines with different digestibility.

  2. Determinants and impacts of international remittances on household welfare in Vietnam.

    Science.gov (United States)

    Pfau, Wade Donald; Giang, Long Thanh

    2009-01-01

    Remittances can potentially help to promote economic development by providing a mechanism to share risks, reduce poverty and improve equality. However, from the viewpoint of economic theory the overall impacts of remittances are uncertain, as different mechanisms lead to opposite impacts. Since the 1990s Vietnam has experienced a dramatic growth in remittance flows from abroad. Vietnam is a unique case for study, as economic motives historically played a smaller role in outward migration than in other countries. Fortunately, household survey data are available for this time period, allowing for a detailed analysis of the impacts of international remittances on Vietnam. Specifically, we examine the characteristics of recipients and the impacts of international remittances on economic inequality and poverty. We conclude that international remittances are helping to improve equality. For this reason, new development policies must also account for their potential impacts on remittance flows.

  3. Standard Test Method for Determining Resistance of Photovoltaic Modules to Hail by Impact with Propelled Ice Balls

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method provides a procedure for determining the ability of photovoltaic modules to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. 1.2 This test method defines test specimens and methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, provides a method for determining changes in electrical performance, and specifies parameters that must be recorded and reported. 1.3 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice ball impact resistance is beyond the scope of this test method. 1.4 The size of the ice ball to be used in conducting this test is not specified. This test method can be used with various sizes of ice balls. 1.5 This test method may be applied to concentrator and nonconcentrator modules. 1.6 The v...

  4. An Empirical Investigation of Students' Motivational Impact upon University Service Quality Perception: A Self-Determination Perspective

    Science.gov (United States)

    Chong, Yit Sean; Ahmed, Pervaiz K.

    2012-01-01

    Based on Deci and Ryan's self-determination theory, this study examines the impact of an individual's motivation in pursuing higher education towards university service quality perception, with the individual's learning style posited as the moderator of the proposed relationship. The consequent effects upon satisfaction and behavioural intentions…

  5. The Impact of Personal Factors on Self-Determination and Early Adulthood Outcome Constructs in Youth with Disabilities

    Science.gov (United States)

    Shogren, Karrie A.; Shaw, Leslie A.

    2016-01-01

    Data from the National Longitudinal Transition Study-2 (NLTS2) were used to examine the impact of three personal factors--race/ethnicity, gender, and family income--on self-determination (i.e., autonomy, psychological empowerment, self-realization) and early adulthood outcome constructs. Findings suggest for those with high incidence disabilities,…

  6. A Narrative Inquiry to Determine the Impact of Learning Communities on Attitude Change of Developmental College Students

    Science.gov (United States)

    Dyett, La Tonya R.

    2011-01-01

    The purpose of this narrative inquiry research study was to explore how learning communities impact attitude changes of developmental college students. The qualitative research design enabled the researcher to determine attitudes, and changes in attitudes, via narratives shared by the participants about their personal experiences. The participants…

  7. An Empirical Investigation of Students' Motivational Impact upon University Service Quality Perception: A Self-Determination Perspective

    Science.gov (United States)

    Chong, Yit Sean; Ahmed, Pervaiz K.

    2012-01-01

    Based on Deci and Ryan's self-determination theory, this study examines the impact of an individual's motivation in pursuing higher education towards university service quality perception, with the individual's learning style posited as the moderator of the proposed relationship. The consequent effects upon satisfaction and behavioural intentions…

  8. The investigation of the impacts of walls and green facades on the optimization of energy consumption in buildings and its role in a sustainable development

    Directory of Open Access Journals (Sweden)

    Sara Heidarian

    2014-07-01

    Full Text Available In recent decades,artificial environments, compared to the natural spaces in urban areas, areexpanding day by day. Following the same trend in Iran, apartment living framewithout any natural space has changed. And it is while the need to nature isstill alive in human beings. Moreover, all over the world due to major problemssuch as global warming, air and water pollution, excessive energy consumptionand its high economic costs, utilizing technologies of sustainable architectureand specially creating green buildings has got great importance. In thisregard, the use of green areas can be used as appropriate strategy in order tosolve existing problems and creating sustainable architecture. In this paperwith research method based on library studies and descriptive analyticapproach, green walls, to improve the energy consumption efficiency inbuildings, have been investigated. And also the role of these systems in visualaesthetics of urban area in line with the objectives of sustainable developmentis examined. It seems that using green walls as a way to reduce the energyconsumption in buildings can be an effective option to advance the goals ofsustainablearchitecture.

  9. A chemostratigraphic method to determine the end of impact-related sedimentation at marine-target impact craters (Chesapeake Bay, Lockne, Tvären)

    Science.gov (United States)

    Ormö, Jens; Hill, Andrew C.; Self-Trail, Jean M.

    2010-01-01

    To better understand the impact cratering process and its environmental consequences at the local to global scale, it is important to know when in the geological record of an impact crater the impact-related processes cease. In many instances, this occurs with the end of early crater modification, leaving an obvious sedimentological boundary between impactites and secular sediments. However, in marine-target craters the transition from early crater collapse (i.e., water resurge) to postimpact sedimentation can appear gradual. With the a priori assumption that the reworked target materials of the resurge deposits have a different chemical composition to the secular sediments we use chemostratigraphy (δ13Ccarb, %Corg, major elements) of sediments from the Chesapeake Bay, Lockne, and Tvären craters, to define this boundary. We show that the end of impact-related sedimentation in these cases is fairly rapid, and does not necessarily coincide with a visual boundary (e.g., grain size shift). Therefore, in some cases, the boundary is more precisely determined by chemostratigraphy, especially carbonate carbon isotope variations, rather than by visual inspection. It is also shown how chemostratigraphy can confirm the age of marine-target craters that were previously determined by biostratigraphy; by comparing postimpact carbon isotope trends with established regional trends.

  10. Determination of the chest wall thicknesses and needle thoracostomy success rates at second and fifth intercostal spaces: a cadaver-based study.

    Science.gov (United States)

    Ozen, Can; Akoglu, Haldun; Ozdemirel, Rifat Ozgur; Omeroglu, Elif; Ozpolat, Cigdem Ulubay; Onur, Ozge; Buyuk, Yalcin; Denizbasi, Arzu

    2016-12-01

    The purposes of this study were to measure the chest wall thicknesses (CWTs) at second intercostal space (ICS) mid-clavicular line (MCL) and fifth ICS MAL directly, and compare the actual success rates of needle thoracostomies (NTs) by inserting a 5-cm-long syringe needle. Predictive values of weight, body mass index (BMI) and CWT were also analyzed. This study included 199 measurements of 50 adult fresh cadavers from both hemithoraces. Five-centimeter-long syringe needles were inserted and secured. Penetration into the pleural cavity was assessed, and CWTs at 4 locations were measured. Achieved power of this study for the primary aim of CWT comparison from 2(nd) and 5(th) ICSs was .94. Overall mean CWTs at 2(nd) ICS MCL and 5(th) ICS MAL were measured as 2.46 ± 0.78 and 2.89 ± 1.09, respectively, and 5(th) ICS MAL was found to be statistically thicker (P = .002). The success rate of NT at 2(nd) ICS MCL was 87% (95% CI, 80-94), and that at 5(th) ICS MAL was 78% (95% CI, 70-86; P = .3570). Only 6 (17.1%) of 35 failed NTs had a CWT greater than 5-cm. Needle thoracostomy has failed in 29 (14.9%) of 194 locations, despite a CWT less than 5-cm. Below a weight of 72 kg, BMI of 23 kg/m(2), or CWT of 2.4 cm, all NTs were successful. In this report, we present the largest cadaver-based cohort to date to the best of our knowledge, and we observed a statistically nonsignificant 9% more NT success rate at 2(nd) ICS at a power of 88% and statistically significant more success rate in males at 5(th) ICS was (47.7%). We also observed thinner CWTs and higher success rates than previous imaging-based studies. A BMI of 23 kg/m(2) or less and weight of 72 kg or less seem to accurately rule-out NT failure in cadavers, and they seem to be better predictors at the bedside. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Determining perception-based impacts of noxious facilities on wage rates and property values

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Clark, D.E.

    1992-02-01

    This document, written for the US Department of Energy, discusses current information and the need for future research on estimating the impacts on wages and property values that could result from people`s perceptions of the risks associated with noxious facilities. Psychometric studies indicate that the US population is averse to living near noxious facilities, nuclear-related facilities in particular. Contingent valuation and hedonic studies find that the net economic impacts of proximity to noxious facilities are generally negative and often substantial. Most of these studies are limited in scope, and none estimate the impacts derived from public perceptions of such facilities. This study examines the mechanisms by which negative public perceptions result in economic impacts reflected in wages and property values. On the basis of these mechanisms, it develops a predictive model of perception-based impacts and identifies the data and methods needed to implement it. The key to predicting perception-based impacts lies in combining psychometric and hedonic methods. The reliability of psychometric measures as indicators of aversive stimuli that precipitate economic impacts can be empirically tested. To test the robustness of the findings, alternative estimation methods an be employed in the hedonic analysis. Contingent valuation methods can confirm the results.

  12. Determining perception-based impacts of noxious facilities on wage rates and property values

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A.; Clark, D.E.

    1992-02-01

    This document, written for the US Department of Energy, discusses current information and the need for future research on estimating the impacts on wages and property values that could result from people's perceptions of the risks associated with noxious facilities. Psychometric studies indicate that the US population is averse to living near noxious facilities, nuclear-related facilities in particular. Contingent valuation and hedonic studies find that the net economic impacts of proximity to noxious facilities are generally negative and often substantial. Most of these studies are limited in scope, and none estimate the impacts derived from public perceptions of such facilities. This study examines the mechanisms by which negative public perceptions result in economic impacts reflected in wages and property values. On the basis of these mechanisms, it develops a predictive model of perception-based impacts and identifies the data and methods needed to implement it. The key to predicting perception-based impacts lies in combining psychometric and hedonic methods. The reliability of psychometric measures as indicators of aversive stimuli that precipitate economic impacts can be empirically tested. To test the robustness of the findings, alternative estimation methods an be employed in the hedonic analysis. Contingent valuation methods can confirm the results.

  13. Comparative study of Trombe wall, water wall and trans wall

    Energy Technology Data Exchange (ETDEWEB)

    Sodha, M.S.; Bansal, N.K.; Singh, S.; Ram, S.; Annamalai, M.; Iyer, M.V.; Nirmala, K.A.; Venkatesh, P.; Prasad, C.R.; Subramani, C.

    1982-01-01

    The thermal performances of three systems viz. Trombe wall: (1) without; and (2) with vents (forced air circulation), water wall and Transwall have been studied analytically interms of heat flux entering the living space (Maintained at 20/sup 0/C) corresponding to the meteriological data on January 19, 1981 at New Delhi (India), a typical cold winter day. Subsequent parametric studies using the simulation indicated that the Transwall system is the more efficient system for the passive heating of buildings.

  14. Fingerprinting the K/T impact site and determining the time of impact by U-Pb dating of single shocked zircons from distal ejecta

    Science.gov (United States)

    Krogh, T. E.; Kamo, S. L.; Bohor, B. F.

    1993-01-01

    U-Pb isotopic dating of single 1 - 3 micrograms zircons from K/T distal ejecta from a site in the Raton Basin, Colorado provides a powerful new tool with which to determine both the time of the impact event and the age of the basement at the impact site. Data for the least shocked zircons are slightly displaced from the 544 +/- 5 Ma primary age for a component of the target site, while those for highly shocked and granular grains are strongly displaced towards the time of impact at 65.5 +/- 3.0 Ma. Such shocked and granular zircons have never been reported from any source, including explosive volcanic rocks. Zircon is refractory and has one of the highest thermal blocking temperatures; hence, it can record both shock features and primary and secondary ages without modification by post-crystallization processes. Unlike shocked quartz, which can come from almost anywhere on the Earth's crust, shocked zircons can be shown to come from a specific site because basement ages vary on the scale of meters to kilometers. With U-Pb zircon dating, it is now possible to correlate ejecta layers derived from the same target site, test the single versus multiple impact hypothesis, and identify the target source of impact ejecta. The ages obtained in this study indicate that the Manson impact site, Iowa, which has basement rocks that are mid-Proterozoic in age, cannot be the source of K/T distal ejecta. The K/T distal ejecta probably originated from a single impact site because most grains have the same primary age.

  15. Shocked monazite chronometry: integrating microstructural and in situ isotopic age data for determining precise impact ages

    Science.gov (United States)

    Erickson, Timmons M.; Timms, Nicholas E.; Kirkland, Christopher L.; Tohver, Eric; Cavosie, Aaron J.; Pearce, Mark A.; Reddy, Steven M.

    2017-03-01

    Monazite is a robust geochronometer and occurs in a wide range of rock types. Monazite also records shock deformation from meteorite impact but the effects of impact-related microstructures on the U-Th-Pb systematics remain poorly constrained. We have, therefore, analyzed shock-deformed monazite grains from the central uplift of the Vredefort impact structure, South Africa, and impact melt from the Araguainha impact structure, Brazil, using electron backscatter diffraction, electron microprobe elemental mapping, and secondary ion mass spectrometry (SIMS). Crystallographic orientation mapping of monazite grains from both impact structures reveals a similar combination of crystal-plastic deformation features, including shock twins, planar deformation bands and neoblasts. Shock twins were documented in up to four different orientations within individual monazite grains, occurring as compound and/or type one twins in (001), (100), ( 10bar{1} ), {110}, { 212 }, and type two (irrational) twin planes with rational shear directions in [0bar{1}bar{1}] and [bar{1}bar{1}0]. SIMS U-Th-Pb analyses of the plastically deformed parent domains reveal discordant age arrays, where discordance scales with increasing plastic strain. The correlation between discordance and strain is likely a result of the formation of fast diffusion pathways during the shock event. Neoblasts in granular monazite domains are strain-free, having grown during the impact events via consumption of strained parent grains. Neoblastic monazite from the Inlandsee leucogranofels at Vredefort records a 207Pb/206Pb age of 2010 ± 15 Ma (2 σ, n = 9), consistent with previous impact age estimates of 2020 Ma. Neoblastic monazite from Araguainha impact melt yield a Concordia age of 259 ± 5 Ma (2 σ, n = 7), which is consistent with previous impact age estimates of 255 ± 3 Ma. Our results demonstrate that targeting discrete microstructural domains in shocked monazite, as identified through orientation mapping, for in

  16. Moduli of monopole walls and amoebas

    Science.gov (United States)

    Cherkis, Sergey A.; Ward, Richard S.

    2012-05-01

    We study doubly-periodic monopoles, also called monopole walls, determining their spectral data and computing the dimensions of their moduli spaces. Using spectral data we identify the moduli, and compare our results with a perturbative analysis. We also identify an SL(2, {Z}) action on monopole walls, in which the S transformation corresponds to the Nahm transform.

  17. Moduli of Monopole Walls and Amoebas

    CERN Document Server

    Cherkis, Sergey A

    2012-01-01

    We study doubly-periodic monopoles, also called monopole walls, determining their spectral data and computing the dimensions of their moduli spaces. Using spectral data we identify the moduli, and compare our results with a perturbative analysis. We also identify an SL(2,Z) action on monopole walls, in which the S transformation corresponds to the Nahm transform.

  18. Standard Practice for Determining Resistance of Solar Collector Covers to Hail by Impact With Propelled Ice Balls

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1992-01-01

    1.1 This practice covers a procedure for determining the ability of cover plates for flat-plate solar collectors to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. This practice is not intended to apply to photovoltaic cells or arrays. 1.2 This practice defines two types of test specimens, describes methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, and specifies parameters that must be recorded and reported. 1.3 This practice does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice-ball impact resistance is beyond the scope of this practice. 1.4 The size of ice ball to be used in conducting this test is not specified in this practice. This practice can be used with various sizes of ice balls. 1.5 The categories of solar collector cover plat...

  19. Simultaneous trace-levels determination of Hg(II) and Pb(II) ions in various samples using a modified carbon paste electrode based on multi-walled carbon nanotubes and a new synthesized Schiff base.

    Science.gov (United States)

    Afkhami, Abbas; Bagheri, Hasan; Khoshsafar, Hosein; Saber-Tehrani, Mohammad; Tabatabaee, Masoumeh; Shirzadmehr, Ali

    2012-10-09

    A modified carbon paste electrode based on multi-walled carbon nanotubes (MWCNTs) and 3-(4-methoxybenzylideneamino)-2-thioxothiazolodin-4-one as a new synthesized Schiff base was constructed for the simultaneous determination of trace amounts of Hg(II) and Pb(II) by square wave anodic stripping voltammetry. The modified electrode showed an excellent selectivity and stability for Hg(II) and Pb(II) determinations and for accelerated electron transfer between the electrode and the analytes. The electrochemical properties and applications of the modified electrode were studied. Operational parameters such as pH, deposition potential and deposition time were optimized for the purpose of determination of traces of metal ions at pH 3.0. Under optimal conditions the limits of detection, based on three times the background noise, were 9.0×10(-4) and 6.0×10(-4) μmol L(-1) for Hg(II) and Pb(II) with a 90 s preconcentration, respectively. In addition, the modified electrode displayed a good reproducibility and selectivity, making it suitable for the simultaneous determination of Hg(II) and Pb(II) in real samples such as sea water, waste water, tobacco, marine and human teeth samples.

  20. Domain Walls on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe domain walls that live on $A_2$ and $A_3$ singularities. The walls are BPS if the singularity is resolved and non--BPS if it is deformed and fibered. We show that these domain walls may interpolate between vacua that support monopoles and/or vortices.

  1. The Lamportian cell wall

    Energy Technology Data Exchange (ETDEWEB)

    Keiliszewski, M.; Lamport, D. (Michigan State Univ. Plant Research Lab., East Lansing (United States))

    1991-05-01

    The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.

  2. Halogenation of microcapsule walls

    Science.gov (United States)

    Davis, T. R.; Schaab, C. K.; Scott, J. C.

    1972-01-01

    Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.

  3. Emergency assistance for farmers affected by the Wall

    Directory of Open Access Journals (Sweden)

    Saed Essawi

    2006-08-01

    Full Text Available Construction of the Wall in the occupied Palestinian territorieshas had a harsh impact on Palestinian farmers, separatingmany from their land. Catholic Relief Services Palestine1has initiated a project to try to mitigate the impact.

  4. Carbon paste electrode incorporating multi-walled carbon nanotube/ferrocene as a sensor for the electroanalytical determination of -acetyl--cysteine in the presence of tryptophan

    Indian Academy of Sciences (India)

    Jahan Bakhsh Raoof; Fereshteh Chekin; Reza Ojani; Saeideh Barari

    2013-03-01

    The preparation and electrochemical performance of the carbon nanotube paste electrode modified with ferrocene (FCMCNPE) was investigated for electrocatalytic behaviour toward oxidation of -acetyl--cysteine (NAC) in the presence of tryptophan (Trp) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results showed an efficient electrocatalytic activity of FCMCNPE toward oxidation of NAC and Trp, as the electrooxidation of NAC and Trp together gave two well-defined anodic peaks, revealing the applicability of this modified electrode for simultaneous voltammetric detection of mentioned compounds in the same solution. The values of catalytic rate constant () and the apparent diffusion coefficient (Dapp) were also calculated using chronoamperometry. The DPV method was applied as a sensitive method for the quantitative detection of trace amounts of NAC and Trp. A linear dynamic range from 1.0 to 18.0 M for NAC and 2.0 to 150.0 M for Trp was obtained using DPV method in pH 7.00 buffered solution and the detection limit (3) was determined as 0.49 M and 0.54 M for NAC and Trp, respectively. The proposed method was also applied for analysis of NAC tablet, investigating the applicability of the proposed voltammetric method for determination of NAC in real sample.

  5. Immersion Refractometry of Isolated Bacterial Cell Walls

    Science.gov (United States)

    Marquis, Robert E.

    1973-01-01

    Immersion-refractometric and light-scattering measurements were adapted to determinations of average refractive indices and physical compactness of isolated bacterial cell walls. The structures were immersed in solutions containing various concentrations of polymer molecules that cannot penetrate into wall pores, and then an estimate was made of the polymer concentration or the refractive index of the polymer solution in which light scattering was reduced to zero. Because each wall preparation was heterogeneous, the refractive index of the medium for zero light scattering had to be estimated by extrapolation. Refractive indices for walls suspended in bovine serum albumin solutions ranged from 1.348 for walls of the rod form of Arthrobacter crystallopoietes to 1.382 for walls of the teichoic acid deficient, 52A5 strain of Staphylococcus aureus. These indices were used to calculate approximate values for solids content per milliliter, and the calculated values agreed closely with those estimated from a knowledge of dextran-impermeable volumes per gram, dry weight, of the walls. When large molecules such as dextrans or serum albumin were used for immersion refractometry, the refractive indices obtained were for entire walls, including both wall polymers and wall water. When smaller molecules that can penetrate wall pores to various extents were used with Micrococcus lysodeikticus walls, the average, apparent refractive index of the structures increased as the molecular size of probing molecules was decreased. It was possible to obtain an estimate of 1.45 to 1.46 for the refractive index of wall polymers, predominantly peptidoglycans in this case, by extrapolating the curve for refractive index versus molecular radius to a value of 0.2 nm, the approximate radius of a water molecule. This relatively low value for polymer refractive index was interpreted as evidence in favor of the amorphous, elastic model of peptidoglycan structure and against the crystalline, rigid

  6. Relationship between the Pelvic Organ Prolapse Quantification system (POP-Q), the Pelvic Floor Impact Questionnaire (PFIQ-7), and the Pelvic Floor Distress Inventory (PFDI-20) before and after anterior vaginal wall prolapse surgery

    DEFF Research Database (Denmark)

    Rudnicki, Martin

    2015-01-01

    weak correlations between POP-Q and PFIQ-7, including subscales (r 0.173-0.324, p Pelvic Organ Prolapse Distress Inventory (POPDI) subscale (r 0.180-0.211, p ...The aim of this study was to investigate the degree of correlation between the Pelvic Organ Quantification system (POP-Q) measurements and symptom questionnaire scores before and after surgery. This was a part of a randomized controlled study comparing conventional colporrhaphy with mesh repair...... surgery. METHODS: The correlation between POP-Q measurements and Pelvic Floor Impact Questionnaire (PFIQ-7) and Pelvic Floor Distress Inventory (PFDI-20) scores was investigated in 164 women 55 years or older scheduled for primary anterior vaginal wall prolapse surgery at baseline and the correlation...

  7. A Typical Magnetohydrodynamic Flow of a Viscous Incompressible Fluid Between a Parallel Flat Wall and a Wavy Wall : Constant Suction Through the Former Wall

    Directory of Open Access Journals (Sweden)

    S. N. Maitra

    1986-01-01

    Full Text Available A magnetohydrodynamic flow of a viscous, incompressible and slightly conducting fluid is developed between a parallel flat wall and a wavy wall whereas at the same time fluid is continuously sucked through the flat wall with a constant suction velocity. The velocity and temperature distribution are determined alongwith the pressure gradient and co-efficient of skin friction.

  8. Determining spatial variability in PM 2.5 source impacts across Detroit, MI

    Science.gov (United States)

    Duvall, Rachelle M.; Norris, Gary A.; Burke, Janet M.; Olson, David A.; Vedantham, Ram; Williams, Ron

    2012-02-01

    Intra-urban variability in air pollution source impacts was investigated using receptor modeling of daily speciated PM 2.5 measurements collected at residential outdoor locations across Detroit, MI (Wayne County) as part of the Detroit Exposure and Aerosol Research Study (DEARS) during summer and winter from 2004 to 2006. Six areas were selected for the residential monitoring in the DEARS to capture impacts from different sources including local industry, motor vehicles, and upwind regional sources. PM 2.5 measurements were also collected at the Allen Park, MI Chemical Speciation Network (CSN) site for comparison with the residential outdoor sites. Sources impacting PM 2.5 were quantified using the EPA Chemical Mass Balance Model (CMB 8.2). Published source profiles were used as input to CMB along with a mixed industrial profile and a steel manufacturing profile obtained by applying the EPA Positive Matrix Factorization Model (PMF 4.0) to CSN data from a Midwestern U.S. site with industrial sources similar to Detroit. Major PM 2.5 sources impacting the Allen Park and residential monitoring areas during DEARS included motor vehicles (24-36% by mass), secondary sulfate/coal combustion (17-35%), secondary nitrate (16-37%) and organic matter (17-21%). Road dust, steel manufacturing, and mixed industrial sources contributed less than 11% by mass. CMB source contribution estimates for Allen Park during the DEARS generally compared well to CMB estimates from the collocated year-long CSN measurements using the same source profiles. CMB source contributions during DEARS showed similar contributions across the residential monitoring areas for secondary sulfate/coal combustion and secondary nitrate consistent with regional impacts for these sources. Contributions from motor vehicles, steel manufacturing, and mixed industrial sources varied across the DEARS monitoring areas, indicating impacts from local sources within the Detroit airshed that may not be well characterized by

  9. Galileo Declassified: IOV Spacecraft Metadata and Its Impact on Precise Orbit Determination

    Science.gov (United States)

    Dilssner, Florian; Schönemann, Erik; Springer, Tim; Flohrer, Claudia; Enderle, Werner

    2017-04-01

    In December 2016, shortly after the declaration of Galileo Initial Services, the European GNSS Agency (GSA) disclosed Galileo spacecraft metadata relevant to precise orbit determination (POD), such as antenna phase center parameters, dimensions of the solar panels and the main body, specularity and reflectivity coefficients for the surface materials, yaw attitude steering law, and signal group delays. The metadata relates to the first four operational Galileo satellites, known as the In-Orbit Validation (IOV) satellites, and is publicly available through the European GNSS Service Center (GSC) web site. One of the dataset's major benefits is that it includes nearly all information about the satellites' surface properties needed to develop a physically meaningful analytical solar radiation pressure (SRP) macro model, or "box-wing" (BW) model. Such a BW model for the IOV spacecraft has now been generated for use in NAPEOS, the European Space Operation Centre's (ESOC's) main geodetic software package for POD. The model represents the satellite as a simple six-sided box with two attached panels, or "wings", and allows for the a priori computation of the direct and indirect (Earth albedo) SRP force. Further valuable parameters of the metadata set are the IOV navigation antenna (NAVANT) phase center offsets (PCOs) and variations (PCVs) inferred from pre-launch anechoic chamber measurements. In this work, we report on the validation of the Galileo IOV metadata and its impact on POD, an activity ESOC has been deeply committed to since the launch of the first Galileo experimental satellite, GIOVE-A, in 2005. We first reanalyze the full history of Galileo tracking data the global International GNSS Service (IGS) network has collected since 2012. We generate orbit and clock solutions based on the widely used Empirical CODE Orbit Model (ECOM) with and without the IOV a priori BW model. For the satellite antennas, we apply the new as well as the standard IGS-recommended phase

  10. A comparison of the impact of CPOE implementation and organizational determinants on doctor-nurse communications and cooperation.

    Science.gov (United States)

    Pelayo, Sylvia; Anceaux, Françoise; Rogalski, Janine; Elkin, Peter; Beuscart-Zephir, Marie-Catherine

    2013-12-01

    To compare the impact of CPOE implementation and of the workplace organizational determinants on the doctor-nurse cooperation and communication processes. A first study was undertaken in eight different wards aimed to identify the different workplace organizations that support doctor-nurse communications'. A second study compared the impact of these organizations and of a CPOE on medication-related doctor-nurse communications. The doctor-nurse communications could be structured into three typical workplace organizations: the common round, the briefing and the opportunistic exchange organizations. The results (i) confirmed the impact of the organizational determinants on the cooperative activities and (ii) demonstrated the CPOE system has no significant impact within a given workplace organization. The success of the implementation of HIT applications relies partly on the identification of the actual (and sometimes hidden) structuring variables of teamwork and ultimately on their control at the time of implementation to ensure the quality and safety of the patient care provided. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  11. Determine an effective golf swing by swing speed and impact precision tests

    Directory of Open Access Journals (Sweden)

    Jiann-Jyh Wang

    2015-09-01

    Conclusion: The vertical peak ground reaction force on left foot occurring before impact and the left latissimus dorsi contracting prior to the right pectoralis major represent a superior skill by allowing the club to strike the ball with normal collision at a faster speed.

  12. Key Factors for Determining Risk of Groundwater Impacts Due to Leakage from Geologic Carbon Sequestration Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Susan [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keating, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mansoor, Kayyum [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dai, Zhenue [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sun, Yunwei [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Trainor-Guitton, Whitney [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brown, Chris [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bacon, Diana [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-01-06

    The National Risk Assessment Partnership (NRAP) is developing a science-based toolset for the analysis of potential impacts to groundwater chemistry from CO2 injection (www.netldoe.gov/nrap). The toolset adopts a stochastic approach in which predictions address uncertainties in shallow underwater and leakage scenarios. It is derived from detailed physics and chemistry simulation results that are used to train more computationally efficient models,l referred to here as reduced-order models (ROMs), for each component system. In particular, these tools can be used to help regulators and operators understand the expected sizes and longevity of plumes in pH, TDS, and dissolved metals that could result from a leakage of brine and/or CO2 from a storage reservoir into aquifers. This information can inform, for example, decisions on monitoring strategies that are both effective and efficient. We have used this approach to develop predictive reduced-order models for two common types of reservoirs, but the approach could be used to develop a model for a specific aquifer or other common types of aquifers. In this paper we describe potential impacts to groundwater quality due to CO2 and brine leakage, discuss an approach to calculate thresholds under which "no impact" to groundwater occurs, describe the time scale for impact on groundwater, and discuss the probability of detecting a groundwater plume should leakage occur.

  13. Determining the impacts of time-based logistics strategies in the Dutch food industry

    NARCIS (Netherlands)

    Muilerman, G.; van der Hoorn, A.I.J.M.; van der Heijden, R.

    2005-01-01

    The trend towards logistics acceleration and increasing time-sensitivity can be discerned in numerous industry sectors. The associated logistics concepts are called time-based strategies. In this paper, the logistics impacts of these strategies are analysed on the basis of case studies within the Du

  14. The impact of chimerism in DNA-based forensic sex determination analysis

    OpenAIRE

    George, Renjith; Donald, Preethy Mary; Nagraj, Sumanth Kumbargere; Idiculla, Jose Joy; Hj Ismail, Rashid

    2013-01-01

    Sex determination is the most important step in personal identification in forensic investigations. DNA-based sex determination analysis is comparatively more reliable than the other conventional methods of sex determination analysis. Advanced technology like real-time polymerase chain reaction (PCR) offers accurate and reproducible results and is at the level of legal acceptance. But still there are situations like chimerism where an individual possess both male and female specific factors t...

  15. The importance of chain connectivity in the formation of non-covalent interactions between polymers and single-walled carbon nanotubes and its impact on dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Sumpter, Bobby G [ORNL; Dadmun, Mark D [ORNL; Driva, Paraskevi [ORNL; Ivanov, Ilia N [ORNL; Geohegan, David B [ORNL; Linton, Dias [ORNL; Feigerle, Charles S [ORNL

    2010-01-01

    In this study we investigate the formation of non-covalent electron donor acceptor (EDA) interactions between polymers and single-walled carbon nanotubes (SWNTs) with the goal of optimizing interfacial adhesion and homogeneity of nanocomposites without modifying the SWNT native surface. Nanocomposites of SWNTs and three sets of polymer matrices with varying composition of electron donating 2-(dimethylamino)ethyl methacrylate (DMAEMA) or electron accepting acrylonitrile (AN) and cyanostyrene (CNSt) were prepared, quantitatively characterized by optical microscopy and Raman spectroscopy (Raman mapping, Raman D* peak shifts) and qualitatively compared through thick film composite visualization. The experimental data show that copolymers with 30 mol% DMAEMA, 45 mol% AN, 23 mol% CNSt and polyacrylonitrile homopolymer have the highest extent of intermolecular interaction, which translates to an optimum SWNT spatial dispersion among the series. These results are found to correlate very well with the intermolecular interaction energies obtained from quantum density functional theory calculations. Both experimental and computational results also illustrate that chain connectivity is critical in controlling the accessibility of the functional groups to form intermolecular interactions. This means that an adequate distance between interacting functional groups on a polymer chain is needed in order to allow efficient intermolecular contact. Thus, controlling the amount of electron donating or withdrawing moieties throughout the polymer chain will direct the extent of EDA interaction, which enables tuning the SWNT dispersion.

  16. The importance of chain connectivity in the formation of non-covalent interactions between polymers and single-walled carbon nanotubes and its impact on dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Linton, Dias [ORNL; Driva, Paraskevi [ORNL; Ivanov, Ilia N [ORNL; Geohegan, David B [ORNL; Feigerle, Charles S [ORNL; Dadmun, Mark D [ORNL

    2010-05-01

    In this study we investigate the formation of non-covalent electron donor acceptor (EDA) interactions between polymers and single-walled carbon nanotubes (SWNTs) with the goal of optimizing interfacial adhesion and homogeneity of nanocomposites without modifying the SWNT native surface. Nanocomposites of SWNTs and three sets of polymer matrices with varying composition of electron donating 2-(dimethylamino)ethyl methacrylate (DMAEMA) or electron accepting acrylonitrile (AN) and cyanostyrene (CNSt) were prepared, quantitatively characterized by optical microscopy and Raman spectroscopy (Raman mapping, Raman D* peak shifts) and qualitatively compared through thick film composite visualization. The experimental data show that copolymers with 30 mol% DMAEMA, 45 mol% AN, 23 mol% CNSt and polyacrylonitrile homopolymer have the highest extent of intermolecular interaction, which translates to an optimum SWNT spatial dispersion among the series. These results are found to correlate very well with the intermolecular interaction energies obtained from quantum density functional theory calculations. Both experimental and computational results also illustrate that chain connectivity is critical in controlling the accessibility of the functional groups to form intermolecular interactions. This means that an adequate distance between interacting functional groups on a polymer chain is needed in order to allow efficient intermolecular contact. Thus, controlling the amount of electron donating or withdrawing moieties throughout the polymer chain will direct the extent of EDA interaction, which enables tuning the SWNT dispersion.

  17. Length separation of single-walled carbon nanotubes and its impact on structural and electrical properties of wafer-level fabricated carbon nanotube-field-effect transistors

    Science.gov (United States)

    Böttger, Simon; Hermann, Sascha; Schulz, Stefan E.; Gessner, Thomas

    2016-10-01

    For an industrial realization of devices based on single-walled carbon nanotube (SWCNTs) such as field-effect transistors (FETs) it becomes increasingly important to consider technological aspects such as intrinsic device structure, integration process controllability as well as yield. From the perspective of a wafer-level integration technology, the influence of SWCNT length on the performance of short-channel CNT-FETs is demonstrated by means of a statistical and comparative study. Therefore, a methodological development of a length separation process based on size-exclusion chromatography was conducted in order to extract well-separated SWCNT dispersions with narrowed length distribution. It could be shown that short SWCNTs adversely affect integrability and reproducibility, underlined by a 25% decline of the integration yield with respect to long SWCNTs. Furthermore, it turns out that the significant changes in electrical performance are directly linked to a SWCNT chain formation in the transistor channel. In particular, CNT-FETs with long SWCNTs outperform reference and short SWCNTs with respect to hole mobility and subthreshold controllability by up to 300% and up to 140%, respectively. As a whole, this study provides a statistical and comparative analysis towards chain-less CNT-FETs fabricated with a wafer-level technology.

  18. A detailed radiation heat transfer study of a dish-Stirling receiver: The impact of cavity wall radiation properties and cavity shapes

    Science.gov (United States)

    Garrido, Jorge; Wang, Wujun; Nilsson, Martin; Laumert, Björn

    2016-05-01

    A detailed 3-D radiation analysis of a dish-Stirling cavity receiver is carried out to estimate the cavity steady-state temperatures in order to assess the receiver integrity, lifetime and efficiency performance. For this purpose, a parabolic dish was modeled with 5.2 m focal length, 8.85 m aperture diameter and 2 mrad surface error. Three generic cavity shapes (cylindrical, diamond-shaped and reverse-conical) with three different emissivities (0.2, 0.4 and 0.7) are studied. Worst-case scenario heat generations (total absorbed radiation), maximum steady-state temperatures and energy balances of the cavities are calculated to evaluate the receiver performance. The results show that reverse-conical cavities can significantly reduce cavity wall peak temperatures (by 40-120 K), improve the temperature evenness and decrease the radiation losses by 4-5%. Regarding radiation properties, low reflectivities present lower steady-state temperatures even for low/moderate direct solar fluxes. Due to the lower temperatures, lower total thermal losses are also expected.

  19. Determination of pyrazole and pyrrole pesticides in environmental water samples by solid-phase extraction using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Ma, Jiping; Lu, Xi; Xia, Yan; Yan, Fengli

    2015-02-01

    A solid-phase extraction (SPE) method using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography was developed for the determination of four pyrazole and pyrrole pesticides (fenpyroximate, chlorfenapyr, fipronil and flusilazole) in environmental water samples. Several parameters, such as extraction adsorbent, elution solvent and volume and sample loading flow rate were optimized to obtain high SPE recoveries and extraction efficiency. The calibration curves for the pesticides extracted were linear in the range of 0.05-10 μg L(-1) for chlorfenapyr and fenpyroximate and 0.05-20 μg L(-1) for fipronil and flusilazole, with the correlation coefficients (r(2)) between 0.9966 and 0.9990. The method gave good precisions (relative standard deviation %) from 2.9 to 10.1% for real spiked samples from reservoir water and seawater; method recoveries ranged 92.2-105.9 and 98.5-103.9% for real spiked samples from reservoir water and seawater, respectively. Limits of detection (S/N = 3) for the method were determined to be 8-19 ng L(-1). The optimized method was successfully applied to the determination of four pesticides of pyrazoles and pyrroles in real environmental water samples. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Electrochemically selective determination of dopamine in the presence of ascorbic and uric acids on the surface of the modified Nafion/single wall carbon nanotube/poly(3-methylthiophene) glassy carbon electrodes.

    Science.gov (United States)

    Quan, Do Phuc; Tuyen, Do Phuc; Lam, Tran Dai; Tram, Phan Thi Ngoc; Binh, Nguyen Hai; Viet, Pham Hung

    2011-12-01

    A voltammetric method based on a combination of incorporated Nafion, single-walled carbon nanotubes and poly(3-methylthiophene) film-modified glassy carbon electrode (NF/SWCNT/PMT/GCE) has been successfully developed for selective determination of dopamine (DA) in the ternary mixture of dopamine, ascorbic acid (AA) and uric acid (UA) in 0.1M phosphate buffer solution (PBS) pH 4. It was shown that to detect DA from binary DA-AA mixture, the use of NF/PMT/GCE was sufficient, but to detect DA from ternary DA-AA-UA mixture NF/SWCNT/PMT/GCE was required. The later modified electrode exhibits superior electrocatalytic activity towards AA, DA and UA thanks to synergic effect of NF/SWCNT (combining unique properties of SWCNT such as high specific surface area, electrocatalytic and adsorptive properties, with the cation selectivity of NF). On the surface of NF/SWCNT/PMT/GCE AA, DA, UA were oxidized respectively at distinguishable potentials of 0.15, 0.37 and 0.53 V (vs. Ag/AgCl), to form well-defined and sharp peaks, making possible simultaneous determination of each compound. Also, it has several advantages, such as simple preparation method, high sensitivity, low detection limit and excellent reproducibility. Thus, the proposed NF/SWCNT/PMT/GCE could be advantageously employed for the determination of DA in real pharmaceutical formulations.

  1. Multi-walled carbon nanotubes as solid-phase extraction sorbents for simultaneous determination of type A trichothecenes in maize, wheat and rice by ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dong, Maofeng; Si, Wenshuai; Jiang, Keqiu; Nie, Dongxia; Wu, Yongjiang; Zhao, Zhihui; De Saeger, Sarah; Han, Zheng

    2015-12-01

    A solid-phase extraction (SPE) procedure using multi-walled carbon nanotubes (MWCNTs) as sorbents coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for simultaneous determination of four type A trichothecenes in maize, wheat and rice for the first time. Several key parameters including the composition of sample loading solutions, washing and elution solvents were thoroughly investigated to achieve optimal SPE recoveries and efficiency. Performance of the MWCNTs materials was significantly affected by pH, and after optimization, n-hexane and 5% methanol aqueous solution as the washing solutions and methanol containing 1% formic acid as the elution solvent presented an excellent purification efficiency for the four targets in the different matrices. The method was validated by determining the linearity (R(2)≥0.992), recovery (73.4-113.7%), precision (1.2-17.1%) and sensitivity (limit of quantification in the range of 0.02-0.10μg/kg), and was further applied for simultaneous determination of type A trichothecenes in 30 samples. Although low contamination levels of type A trichothecenes in wheat, maize and rice were observed revealing mitigated risks to consumers in Shanghai, China, the developed method has proven to be a valuable tool for type A trichothecenes monitoring in complex crop matrices.

  2. Determination of the Impact of Working Capital Management on Profitability: An Empirical Study from the Cement Sector in Pakistan

    OpenAIRE

    Mobeen Ur Rehman; NaveedAnjum

    2013-01-01

    This paper examines the impact that the running assets management on the profitability of Pakistan cement sector. Moreover, the study outlines the main factors that basically determine the working capital in the financials of Pakistan cement sector. To manage firm’ sliquid assets which is working capital management and to reach a desire equilibrium level among profitability and risk, figures was collected from Annual Reports and sample consist of 10 Pakistani cement Companies listed at KSE fr...

  3. Understanding the determinants of the complex interplay between cost-effectiveness and equitable impact in maternal and child mortality reduction

    Directory of Open Access Journals (Sweden)

    Mickey Chopra

    2012-06-01

    Full Text Available One of the most unexpected outcomes arising from the efforts towards maternal and child mortality reduction is that all too often the objective success has been coupled with increased inequity in the population. The aim of this study is to analyze the determinants of the complex interplay between cost-effectiveness and equity and suggest strategies that will promote an impact on mortality that reduce population child health inequities.

  4. Impact

    NARCIS (Netherlands)

    Lohse, Detlef; Bergmann, Raymond; Mikkelsen, Rene; Zeilstra, Christiaan; Meer, van der Devaraj; Versluis, Michel

    2004-01-01

    A lot of information on impacts of solid bodies on planets has been extracted from remote observations of impact craters on planetary surfaces; experiments however with large enough impact energies as compared to the energy stored in the ground are difficult. We approach this problem by downscaled e

  5. The criteria weight determination of factors impacting the melt flow index of degradable plastics using Lambda-Max method

    Science.gov (United States)

    Dom, Rosma Mohd; Saadon, Nurul Adzlyana; Mohamad, Daud

    2013-09-01

    Three common methods of determining criteria weights using the Analytic Hierarchy Process (AHP) are extent analysis, logarithmic least square method (LLSM) and Lambda-Max. Lambda-Max criteria weights determination method uses pair wise comparison of criteria considered. Studies have shown that Lambda-Max is a preferred criteria weight determination method since it involves lesser computation with consistent results of precise criteria weights generated. In this paper the criteria weights of four factors impacting the Melt Flow Index of degradable plastics are calculated using Lambda-Max method. The input factors (criteria) are the percentages by mass of polyethylene, oil palm biomass, palm olein and starch used in the formulation of degradable plastics. The criteria weights are calculated using Lambda-Max based on input given by four experts. The finding indicates the feasibility of using Lambda-Max method in criteria weight determination for determining the impact of four factors in the formulation of degradable plastics as reflected by the consistency control index value calculated.

  6. Molecularly imprinted polymers coated on multi-walled carbon nanotubes through a simple indirect method for the determination of 2,4-dichlorophenoxyacetic acid in environmental water

    Science.gov (United States)

    Yang, Weijie; Jiao, Feipeng; Zhou, Lei; Chen, Xiaoqing; Jiang, Xinyu

    2013-11-01

    A new and facile method was presented to graft molecularly imprinted polymers (MIPs) on carbon nanotubes (CNTs) for 2,4-dichlorophenoxyacetic acid (2,4-D) analysis. In brief, CNTs were firstly coated with a layer of vinyl group modified silica, followed by a common precipitation polymerization with 2,4-D as the template, ethylene glycol dimethacrylate (EGDMA) as the crosslinker and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The imprinted effects obtained by using different monomers were investigated, and the results showed that acrylamide (AM) and styrene as mixed monomers was the best choice. This functionalized material was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetry (TG), which demonstrated a successful polymerization reaction on CNTs with MIPs grafting ratio of about 80%. The results of static adsorption experiments indicated the imprinted material possessed fast kinetics and good selectivity for 2,4-D molecules. A corresponding analytical method was developed and demonstrated to be applicable for the determination of 2,4-D in environmental water. The recoveries were in the range from 74.6% to 81.2% with relative standard deviation below 7.0%. To be emphasized, the method for MIPs coating proposed herein also provides a significant reference for other radical polymerization reactions based on CNTs.

  7. Molecularly imprinted polymers coated on multi-walled carbon nanotubes through a simple indirect method for the determination of 2,4-dichlorophenoxyacetic acid in environmental water

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Weijie; Jiao, Feipeng; Zhou, Lei; Chen, Xiaoqing, E-mail: xqchen@mail.csu.edu.cn; Jiang, Xinyu, E-mail: jiangxinyu@mail.csu.edu.cn

    2013-11-01

    A new and facile method was presented to graft molecularly imprinted polymers (MIPs) on carbon nanotubes (CNTs) for 2,4-dichlorophenoxyacetic acid (2,4-D) analysis. In brief, CNTs were firstly coated with a layer of vinyl group modified silica, followed by a common precipitation polymerization with 2,4-D as the template, ethylene glycol dimethacrylate (EGDMA) as the crosslinker and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The imprinted effects obtained by using different monomers were investigated, and the results showed that acrylamide (AM) and styrene as mixed monomers was the best choice. This functionalized material was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetry (TG), which demonstrated a successful polymerization reaction on CNTs with MIPs grafting ratio of about 80%. The results of static adsorption experiments indicated the imprinted material possessed fast kinetics and good selectivity for 2,4-D molecules. A corresponding analytical method was developed and demonstrated to be applicable for the determination of 2,4-D in environmental water. The recoveries were in the range from 74.6% to 81.2% with relative standard deviation below 7.0%. To be emphasized, the method for MIPs coating proposed herein also provides a significant reference for other radical polymerization reactions based on CNTs.

  8. Abdominal wall fat pad biopsy

    Science.gov (United States)

    Amyloidosis - abdominal wall fat pad biopsy; Abdominal wall biopsy; Biopsy - abdominal wall fat pad ... method of taking an abdominal wall fat pad biopsy . The health care provider cleans the skin on ...

  9. Determination of the correction factor for attenuation, dispersion and production of electrons (K{sub wall}) in the wall of graphite of a ionization chamber Pattern National Type CC01 in fields of gamma radiation of {sup 60}Co; Determinacion del factor de correccion por atenuacion, dispersion y produccion de electrones (K{sub wall}) en la pared de grafito de una Camara de Ionizacion Patron Nacional Tipo CC01 en campos de radiacion gamma de {sup 60} Co

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T.; Morales P, J.; Cruz E, P. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-12-15

    It was determined the Kwall correction factor for the wall of graphite of the chamber of the pattern national type CC01 series 133 for a radiation field Gamma of {sup 60}Co. With this end to measured the currents of ionization l(x) as function of the thickness of the wall of the chamber: X=4,8,12,16 and 20 mm.The mensurations for each thickness consisting of three groups, of sizes n = 30 or 60 data for each group; obtaining 8 complete groups of mensurations independent in eight different dates.The determinate the factor carried out using three regression models: lineal, logarithmic and quadratic, models that were tried to validate with the tests of : i) Shapiro-Wilk and {chi}{sup 2} for the normality of the entrance data ii) Tests of Bartlett for variances homogeneity among groups for each thickness iii) The tests of Duncan for the stockings among groups of each thickness, and iv) The tests of adjustment lack (LOF) for the models used. Nevertheless, alone the models of the group of corresponding mensurations at 01-03-2000 17-08-2001 they can be validated by LOF, but not for tests of normality and homogeneity of variances. Among other assignable causes of variation we have: i) The values captured by the system of mensuration of the variables of it influences: pressure, temperature and relative humidity don{sup t} belong together with the existent ones to the moment to capture the l(x). ii) The mensuration room presents flows of air, for what was suited o diminish their volume and to eliminate the flows of air. iii) A protocol settled down of taking of measures that it consisted in: - Pre-irradiation 5 minutes the chamber after the change of polarity and hood change, with a period of stabilization of 5 minutes after the pre-irradiation. - Pre-irradiation for 5 minutes before the taking of the readings, with the object of eliminating variation sources assigned to currents of escapes or due variations to transitory. iv) To realize corrections for relative humidity of

  10. Scaling analysis on filtered near wall turbulence

    Science.gov (United States)

    Mohan, Prakash; Moser, Robert

    2016-11-01

    Large Eddy Simulations (LES) directly represent larger scale turbulent motions and model the effects of small scale motions. However in the near wall region the large dynamically important eddies scale in viscous wall units, which makes resolving them in a high Reynolds number LES very expensive. This motivates the use of wall-modeled LES, in which these near-wall eddies are modeled. To aid in the development of new wall models, we pursue an asymptotic analysis of the filtered Navier-Stokes equations, in the limit in which the horizontal filter scale is large compared to the thickness of the wall layer. It will be shown that in this limit the filtered velocities u and subgrid stresses τ in the near-wall layer are determined to zeroth order by filtered velocities at the boundary of the wall layer. Further the asymptotics suggest that there is a scaled universal velocity profile f and subgrid stress profile g in the near-wall region. The validity of this result will be tested and the profiles f and g will be evaluated through analysis of DNS data from channel flow at Reτ = 5200 .

  11. Environmental impact of multi-wall carbon nanotubes in a novel model of exposure: systemic distribution, macrophage accumulation, and amyloid deposition.

    Science.gov (United States)

    Albini, Adriana; Pagani, Arianna; Pulze, Laura; Bruno, Antonino; Principi, Elisa; Congiu, Terenzio; Gini, Elisabetta; Grimaldi, Annalisa; Bassani, Barbara; De Flora, Silvio; de Eguileor, Magda; Noonan, Douglas M

    2015-01-01

    Carbon nanotubes (CNTs) have been extensively investigated and employed for industrial use because of their peculiar physical properties, which make them ideal for many industrial applications. However, rapid growth of CNT employment raises concerns about the potential risks and toxicities for public health, environment, and workers associated with the manufacture and use of these new materials. Here we investigate the main routes of entry following environmental exposure to multi-wall CNTs (MWCNTs; currently the most widely used in industry). We developed a novel murine model that could represent a surrogate of a workplace exposure to MWCNTs. We traced the localization of MWCNTs and their possible role in inducing an innate immune response, inflammation, macrophage recruitment, and inflammatory conditions. Following environmental exposure of CD1 mice, we observed that MWCNTs rapidly enter and disseminate in the organism, initially accumulating in lungs and brain and later reaching the liver and kidney via the bloodstream. Since recent experimental studies show that CNTs are associated with the aggregation process of proteins associated with neurodegenerative diseases, we investigated whether MWCNTs are able to induce amyloid fibril production and accumulation. Amyloid deposits in spatial association with macrophages and MWCNT aggregates were found in the brain, liver, lungs, and kidneys of exposed animals. Our data suggest that accumulation of MWCNTs in different organs is associated with inflammation and amyloid accumulation. In the brain, where we observed rapid accumulation and amyloid fibril deposition, exposure to MWCNTs might enhance progression of neurodegenerative and other amyloid-related diseases. Our data highlight the conclusion that, in a novel rodent model of exposure, MWCNTs may induce macrophage recruitment, activation, and amyloid deposition, causing potential damage to several organs.

  12. The impact of thermal fatigue and carbidization on the W coatings deposited on CFC tiles for the ITER-like Wall project at JET

    Energy Technology Data Exchange (ETDEWEB)

    Ruset, C., E-mail: ruset@infim.ro [National Institute for Laser, Plasma and Radiation Physics, Bucharest, Euratom-MEdC Association Romania (Romania); Grigore, E.; Falie, D.; Gherendi, M. [National Institute for Laser, Plasma and Radiation Physics, Bucharest, Euratom-MEdC Association Romania (Romania); Maier, H. [Max-Plank Institut für Plasma Physik, Euratom Association, 85748 Garching (Germany); Rasinski, M. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Matthews, G.F. [Culham Centre for Fusion Energy, Euratom Association, Abingdon (United Kingdom); Zoita, V. [National Institute for Laser, Plasma and Radiation Physics, Bucharest, Euratom-MEdC Association Romania (Romania); EFDA Close Support Unit, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)

    2013-10-15

    Highlights: ► Degradation curves of the W coatings depend on temperature and number of pulses. ► Thermo-mechanical properties of the W coatings are associated with degradation curves. ► Thermal fatigue and carbidization affect the interface between CFC and W. ► A pore structure was detected at the interface by SEM examination. -- Abstract: Since August 2011 JET operates with the ITER-like wall comprising bulk Be tiles, bulk W tiles and W coated CFC tiles with a thickness of 10–15 μm and 20–25 μm. In order to evaluate behavior of the W coatings to a cyclic thermal loading relevant to JET operation, high heat flux (HHF) tests have been carried out up to 5100 pulses with an electron beam facility at peak temperatures of 1000 °C, 1250 °C and 1450 °C. The pulse duration was 24 s. Optical inspections of the W layer performed periodically by interrupting the test revealed small delaminations with the size of 50–500 μm. The dependence of the delamination percentage on the number of pulses can be seen as a degradation curve for each particular W coating. In this way the thermo-mechanical properties of the W coatings can be characterized quantitatively. Thermal fatigue and carbidization of the tungsten due to the diffusion of the carbon from the substrate have been recognized as mechanisms for degradation of the coatings. Tungsten carbides have been identified by using TEM (transmission electron microscopy) diffraction analysis on FIB (focused ion beam) prepared cross-section samples subjected to HHF tests. Nano-pores developed at the CFC–Mo and Mo–W interfaces during the tests might be also responsible for the degradation of the coating.

  13. Determinants of green innovation, the impact of internal and external knowledge

    OpenAIRE

    Stucki, Tobias; Woerter, Martin

    2012-01-01

    Based on a comprehensive data set comprising 13 countries, 22 industries and a period of 30 years we investigate the impact of internal and external knowledge pools of both green and ‘other than green’ technologies on green patent activities. It turned out that the internal green knowledge stock is positively related to green patent activities with a considerably large marginal value. The country’s green knowledge stock and the green knowledge stock of the same industry in other countries are...

  14. A method to determine the impact of visual function on lesion detection performance

    OpenAIRE

    Thompson, J. D.; Lança, Carla Costa; Lança, Luís; Hogg, Peter

    2016-01-01

    There are few professions in which visual acuity is as important as it is to radiologists. The diagnostic decision making process is composed of a number of events (detection or observation, interpretation and reporting), where the detection phase is subject to a number of physical and psychological phenomena that are critical to the process. Visual acuity is one phenomenon that has often been overlooked, and there is very little research assessing the impact of reduced visual acuity on diagn...

  15. Determinants Of urban Residents' Perceived Tourism Impacts: a Study on the Williamsburg and Virginia Beach Areas

    OpenAIRE

    Yoon, Yooshik

    1998-01-01

    ABSTRACT The existing research in the field of tourism has exhibited a clearer understanding of how residents perceive the dynamic and complex phenomena of tourism. Since the goals of tourism planning and development are to seek maximization of benefits and minimization of the costs of tourism, it is apparent that the effective evaluation of tourism impacts will be valuable information in successful strategies for tourism product development and operation. With these perspectives, this...

  16. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  17. Commercial Impact and Optimum Capacity Determination of Pumped Storage Hydro Plant for a Practical Power System

    Science.gov (United States)

    Latha, P. G.; Anand, S. R.; Imthias, Ahamed T. P.; Sreejith, P. S., Dr.

    2013-06-01

    This paper attempts to study the commercial impact of pumped storage hydro plant on the operation of a stressed power system. The paper further attempts to compute the optimum capacity of the pumped storage scheme that can be provided on commercial basis for a practical power system. Unlike the analysis of commercial aspects of pumped storage scheme attempted in several papers, this paper is presented from the point of view of power system management of a practical system considering the impact of the scheme on the economic operation of the system. A realistic case study is presented as the many factors that influence the pumped storage operation vary widely from one system to another. The suitability of pumped storage for the particular generation mix of a system is well explored in the paper. To substantiate the economic impact of pumped storage on the system, the problem is formulated as a short-term hydrothermal scheduling problem involving power purchase which optimizes the quantum of power to be scheduled and the duration of operation. The optimization model is formulated using an algebraic modeling language, AMPL, which is then solved using the advanced MILP solver CPLEX.

  18. Techniques for determination of impact forces during walking and running in a zero-G environment

    Science.gov (United States)

    Greenisen, Michael; Walton, Marlei; Bishop, Phillip; Squires, William

    1992-01-01

    One of the deleterious adaptations to the microgravity conditions of space flight is the loss of bone mineral content. This loss appears to be at least partially attributable to the minimal skeletal axial loading concomitant with microgravity. The purpose of this study was to develop and fabricate the instruments and hardware necessary to quantify the vertical impact forces (Fz) imparted to users of the space shuttle passive treadmill during human locomotion in a three-dimensional zero-gravity environment. The shuttle treadmill was instrumented using a Kistler forceplate to measure vertical impact forces. To verify that the instruments and hardware were functional, they were tested both in the one-G environment and aboard the KC-135 reduced gravity aircraft. The magnitude of the impact loads generated in one-G on the shuttle treadmill for walking at 0.9 m/sec and running at 1.6 and 2.2 m/sec were 1.1, 1.7, and 1.7 G, respectively, compared with loads of 0.95, 1.2, and 1.5 G in the zero-G environment.

  19. 血液黏滞系数对颅内大型动脉瘤剪切力的影响%Impact of blood viscosity on wall shear stress of large intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    吴京; 刘爱华; 赵艺; 符策基; 彭汤明; 钱增辉; 康慧斌; 吴中学

    2015-01-01

    Objective To simulate the computational hemodynamics of large intracranial aneurysms and analyze the impact of blood viscosity on wall shear stress.Methods Eight large intracranial aneurysms at internal carotid artery between June 2013 and July 2013 were studied retrospectively.Among them,3 aneurysms were ruptured and 5 were unruptured.Pulsatile CFD simulations were carried out using three levels of blood viscosity (0.002,0.004,0.012 Pa·s).For each aneurysm model,the average wall shear stress (WSS) predicted by the three blood viscosity levels were compared.Results Blood viscosity has significant impaction on average wall shear stress of intracranial aneurysms and parent artery.Average wall shear stress increased significantly with the increase of blood viscosity.When blood viscosity was 0.002,0.004,0.012 Pa·s,the average wall shear stress of aneurysms was (2.79 ±2.23),(5.27 ±3.72) and (11.05 ± 7.56) Pa,respectively.The average wall shear stress of parent artery was (5.61 ± 2.59),(9.56 ± 3.74) and (22.56 ± 12.41) Pa respectively.A reduction in wall shear stress between the parent artery and the aneurysm sac was found in all the cases.Conclusion Abnormal increase or decrease in blood viscosity may aggravate vascular wall damage and increase the risk of aneurysmal rupture.It is necessary to adopt patient-specific value of blood viscosity in future hemodynamic studies of intracranial aneurysms.%目的 应用血流动力学数值模拟技术分析不同血液黏滞系数对颅内大型动脉瘤剪切力水平的影响.方法 收集我院2013年6月至2013年7月收治的8例颅内大型囊性动脉瘤患者脑血管三维影像数据,其中破裂动脉瘤3例,未破裂动脉瘤5例.应用CFD ICEM软件对动脉瘤三维模型进行网格划分,再进行流体力学数值模拟计算.在血液黏滞系数为0.002、0.004和0.012 Pa·s 3种水平时对颅内大型动脉瘤进行血流动力学数值模拟运算并比较动脉瘤及载

  20. Determine disturbance impacts of fireworks at the Coquille Point seabird colony complex near Bandon, Oregon

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The USFWS conducted a monitoring study at Pirate Cove Rock during 2011 to determine if the Independence Day fireworks display had any adverse effects on seabirds,...

  1. Modeling the fertility impact of the proximate determinants: Time for a tune-up

    Directory of Open Access Journals (Sweden)

    John Bongaarts

    2015-09-01

    Full Text Available Background: Many analyses of the determinants of fertility make a distinction between proximate and background determinants. The former include behavioral factors such as the use of contraception or abortion through which the background determinants (e.g., social and economic variables affect fertility. These relationships were first recognized by Davis and Blake (1956, who defined a large set of "intermediate fertility variables." In the late 1970s Bongaarts (1978 identified a smaller set of proximate determinants and developed a relatively simple model to quantify their fertility effects. Objective: This paper fine-tunes the Bongaarts proximate determinants model in light of new evidence, research, and data that have become available over the past three decades. Reproductive behavior has changed substantially and certain original simplifying assumptions have become less accurate over time. In addition, new research allows some features of the model to be improved. Methods: Six adjustments to the model are proposed and implemented. The revised model is compared with the original version and with a revision proposed by Stover (1998. Results: Revised estimates of the indexes of the proximate determinants and total fecundity are provided for the most recent DHS surveys in 36 developing countries. The revised model provides a better fit than do earlier models. Conclusions: The proximate determinants model, as originally conceived, remains conceptually sound. However, theoretical and empirical evidence accumulated over the past three decades suggests a number of ways to fine-tune the model to make it more robust and accurate in contemporary populations. The resulting revised model provides an improved assessment of the roles of the proximate determinants in national and sub-national populations.

  2. Linking invasive exotic vertebrates and their ecosystem impacts in Tierra del Fuego to test theory and determine action

    Science.gov (United States)

    Valenzuela, Alejandro E. J.; Anderson, Christopher B.; Fasola, Laura; Cabello, José L.

    2014-01-01

    Understanding processes and impacts of biological invasions is fundamental for ecology and management. Recent reviews summarized the mechanisms by which invasive species alter entire ecosystems, but quantitative assessments of these mechanisms are lacking for actual assemblages to determine their relative importance, frequency and patterns. We updated information on introduced vertebrates in the Tierra del Fuego Archipelago (TDF) via an exhaustive literature review and new data to evaluate ecosystem impact mechanisms and provide management recommendations. To date, 24 exotic vertebrates have naturalized in TDF, outnumbering natives nearly 2:1, with the North American beaver (Castor canadensis) and muskrat (Ondatra zibethica) being the most widely distributed species and also impacting the ecosystem through the greatest number of mechanisms. Introduced vertebrates occupied most parts of the archipelago with human-inhabited islands having greater taxa richness. All exotics potentially altered ecosystems by one or more mechanisms: 100% food webs, 92% invasional meltdown, 42% habitat modification, 38% disease or parasite transmission, 21% soil property and disturbance regime changes. Impact to habitat structure was the main clustering criterion for this assemblage. Within the species that physically alter habitats, we found two sub-groups: 1) large herbivores and 2) "others" including beavers and muskrats. Species that did not alter habitat were divided further into those with predatory trophic effects (carnivorous mammals and trout, sub-group 4) and the rest with assorted impacts (sub-group 3). By establishing high quality information on archipelago-wide assemblage, distribution, impacts and mechanisms for exotic vertebrates, we recommend, based on ecological criteria, prioritizing the management of sub-group 2. A secondary priority might be given to the carnivores in sub-group 4, while species in sub-groups 1 and 3 are less urgent. As the first systematic survey of

  3. Solar heating wall

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, J.L.

    1983-08-16

    A solar heating wall is disclosed including a water pipe circulation system having a plurality of separate tubes, each formed as a loop, connected between a water supply and a return. The separate tubes are arranged in a single vertical plane at the approximate center of the wall. The wall is formed within a frame which is packed with a material suited for use as a thERMAL RESERVOIR, SUCH AS concrete. The frame provides extra support by having a series of horizontally disposed cross supports on one surface of the wall and a series of vertically disposed cross supports on the opposite surface A pressure relief valve may be provided between the water supply to the separate tubes and the water supply to the building or structure containing the solar wall, so that the solar wall can be adapted for use with a city water system.

  4. Synthesis and application of multi-walled carbon nanotubes-molecularly imprinted sol-gel composite material for on-line solid-phase extraction and high-performance liquid chromatography determination of trace Sudan IV

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhaohui, E-mail: zhaohuizhang77@hotmail.com [College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Zhang Huabin; Hu Yufang [College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000 (China); Yao Shouzhuo [State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China)

    2010-02-28

    A novel composite material of multi-walled carbon nanotubes (MWNTs)-Sudan IV molecularly imprinted polymers (MIPs) was prepared by surface molecular imprinting technique in combination with sol-gel technology. The MWNTs-MIPs were evaluated by scanning electron micrograph (SEM), Fourier transform infrared spectroscopy (FT-IR), and adsorption experiments. The results showed that the MWNTs-MIPs exhibited good selective recognition to Sudan IV. The maximum saturated binding capacity (Q{sub max}) is 63.2 {mu}mol g{sup -1}. Applied as sorbent, the MWNTs-MIPs were used for the determination of trace Sudan IV in chilli powder by on-line solid-phase extraction-high-performance liquid chromatography (SPE-HPLC). The results showed that an enrichment factor of 741 was achieved with a loading flow rate of 1.0 mL min{sup -1} for sampling 50 mL. The MWNTs-MIPs provided a fast and convenience determination platform for Sudan IV in real samples.

  5. Selective solid-phase extraction of naproxen drug from human urine samples using molecularly imprinted polymer-coated magnetic multi-walled carbon nanotubes prior to its spectrofluorometric determination.

    Science.gov (United States)

    Madrakian, Tayyebeh; Ahmadi, Mazaher; Afkhami, Abbas; Soleimani, Mohammad

    2013-08-21

    A drug imprinted polymer based on suspension polymerization on magnetic multi-walled carbon nanotubes (MIPMCNTs) was prepared with a synthesized amidoamine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, naproxen (NAP) as the template and ammonium persulfate as the initiator. The MIPMCNTs were characterized by TEM, FT-IR and XRD measurements. The prepared magnetic adsorbent can be well dispersed in aqueous media and can be easily separated magnetically from the medium after loading with NAP. All the aspects influencing the adsorption (extraction time, adsorbent dosage and pH) and desorption (desorption time and desorption solvent) of the analyte on the MIPMCNTs have been investigated. The extracted NAP could be easily desorbed with a mixture of methanol/sodium hydroxide aqueous solution and determined spectrofluorometrically at λem = 353 nm (λex = 271 nm). A linear dynamic range was established from 4.0 to 40.0 ng mL⁻¹ of NAP and the limit of detection (LOD) was found to be 2.0 ng mL⁻¹. In addition, the equilibrium adsorption data of NAP by imprinted polymer were analyzed by Langmuir and Freundlich isotherm models. The developed method was utilized for the determination of NAP in human urine samples with satisfactory results.

  6. Channel Wall Landslides

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation. Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  7. A pilot study of the impact of high-frequency chest wall oscillation in chronic obstructive pulmonary disease patients with mucus hypersecretion

    Directory of Open Access Journals (Sweden)

    Chakravorty I

    2011-12-01

    Full Text Available Indranil Chakravorty1, Kamaljit Chahal2, Gillian Austin21St George's Hospital, London, 2East and North Hertfordshire NHS Trust, Lister Hospital and Primary Care Trust, Stevenage, Hertfordshire, UKIntroduction: Chronic obstructive pulmonary disease (COPD patients with mucus hypersecretion tend to demonstrate increased frequency of infective exacerbations and a steeper slope of decline in lung function. Enhanced mucociliary clearance with high-frequency chest wall oscillation (HFCWO devices previously used in cystic fibrosis and bronchiectasis patients may offer the opportunity for community-based, self-managed therapy to improve quality of life and lung function.Study design and methods: A randomized controlled crossover pilot study of HFCWO compared with conventional treatment was conducted in 22 patients with moderate to severe COPD and mucus hypersecretion. Patients spent 4 weeks using an HFCWO (SmartVest® device and 4 weeks in a conventional phase with a 2-week washout. Eleven patients started with HFCWO and changed to conventional treatment, whereas the other eleven patients started conventional treatment and crossed over to HFCWO.Results: The patients were elderly with a mean age of 71 (standard deviation [SD] 10 years and were at the upper end of the normal range of body mass index (25 [SD 4.2] kg/m2. The majority of patients had moderate to severe COPD with a mean percentage predicted forced expiratory volume in 1 second of 41 (SD 15.6 and percentage predicted forced vital capacity of 73 (SD 17.7. Baseline sputum production was negatively correlated to lung function and positively to St George's Respiratory Questionnaire. Symptom scores and St George's Respiratory Questionnaire symptom dimension improved significantly (-8, P < 0.05. Sputum production showed a declining trend in the HFCWO phase, although not reaching statistical significance. The HFCWO device was well tolerated with good reported compliance.Conclusion: This pilot study

  8. Highly sensitive voltammetric sensor based on immobilization of bisphosphoramidate-derivative and quantum dots onto multi-walled carbon nanotubes modified gold electrode for the electrocatalytic determination of olanzapine

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi-Behzad, Leila [Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Gholivand, Mohammad Bagher, E-mail: mbgholivand@yahoo.com [Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Shamsipur, Mojtaba [Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Gholivand, Khodayar [Department of Chemistry, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Barati, Ali [Department of Analytical Chemistry, Faculty of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Gholami, Akram [Department of Chemistry, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2016-03-01

    In the present paper, a new bisphosphoramidate derivative compound, 1, 4-bis(N-methyl)-benzene-bis(N-phenyl, N-benzoylphosphoramidate) (BMBPBP), was synthesized and used as a mediator for the electrocatalytic oxidation of olanzapine. The electro-oxidation of olanzapine at the surface of the BMBPBP/CdS-quantum dots/multi-walled carbon nanotubes (BMBPBP/CdS-QDs/MWCNTs) modified gold electrode was studied using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. This sensor showed an excellent electrocatalytic oxidation activity toward olanzapine at less positive potential, pronounced current response, and good sensitivity. The diffusion coefficient and kinetic parameters (such as electron transfer coefficient and the heterogeneous rate constant) were determined for olanzapine oxidation, using the electrochemical approaches. Surface morphology and electrochemical properties of the prepared modified electrode were investigated by scanning electron microscopy (SEM), cyclic voltammetry and electrochemical impedance spectroscopy techniques. The hydrodynamic amperometry at rotating modified electrode at constant potential versus reference electrode was used for detection of olanzapine. Under optimized conditions, the calibration plot was linear in the concentration range of 20 nM to 100 μM and detection limit was found to be 6 nM. The proposed method was successfully applied to the determination of olanzapine in pharmaceuticals and human serum samples. - Highlights: • A highly sensitive sensor for OLZ determination was developed. • The sensor constructed based on immobilization of BMBPBP on CdS-QDs/MWCNTs Au electrode • The morphology of the modified electrode was examined by SEM. • The prepared sensor shows stable electrochemical behavior at a wide pH range. • The proposed sensor is used for trace determination of OLZ in real samples.

  9. The Manannan Impact Crater on Europa: Determination of Surface Compositions of Key Stratigraphic Units

    Science.gov (United States)

    Dalton, J. B.; Prockter, L. M.; Shirley, J. H.; Phillips, C. B.; Kamp, L.

    2011-12-01

    Mannanan is a 22-km-diameter impact crater located at 3 N, 240 W on Europa's orbital trailing side. Detailed high resolution geologic mapping by Moore et al. (2001) revealed the likely presence of extensive deposits of impact melt materials largely filling the crater floor, together with surrounding continuous ejecta deposits that may have been excavated from Europa's interior. Terrains surrounding Mannanàn include some of Europa's visibly darkest surfaces, with extensive areas of chaos, traversed by the prominent structure of Belus Linea. The Mannannàn impact crater and its surrounding areas were imaged during the C3 orbital encounter of the Galileo Mission by the orbiter's Near-Infrared Mapping Spectrometer (NIMS). This NIMS observation (C3ENLINEA01A) has not been subjected to a detailed investigation until now, possibly due to the presence of moderate levels of radiation noise. A "despiked" version of this observation has been produced using methods described in Shirley et al. (2010). In addition, new geologic mapping precisely registered to the NIMS coverage of Manannàn and its surroundings allows the extraction of high-quality near-infrared spectra that are specific to individual geologic units and morphological features. We will present linear mixture modeling solutions for the compositions of several of Manannàn's key stratigraphic units, including the crater floor deposits and the adjacent chaos and linea materials. We will interpret these results in the context of ongoing investigations of the interplay of exogenic and endogenic influences on the surface composition of Europa. This work was performed at the Jet Propulsion Laboratory-California Institute of Technology, Johns Hopkins University-Applied Physics Laboratory, and the SETI Institute under a contract with NASA. Support by NASA's Outer Planets Research program is gratefully acknowledged. Moore, J. M. and 25 others 2001. Impact Features on Europa: Results of the Galileo Europa Mission (GEM

  10. Staggered domain wall fermions

    CERN Document Server

    Hoelbling, Christian

    2016-01-01

    We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared to usual domain wall fermions. Moreover, we present first results for four-dimensional quantum chromodynamics, where we also observe significant reductions of chiral symmetry violations for staggered domain wall fermions.

  11. Green walls in Vancouver

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture Inc., Vancouver, BC (Canada)

    2007-07-01

    With the renewed interest in design for microclimate control and energy conservation, many cities are implementing clean air initiatives and sustainable planning policies to mitigate the effects of urban climate and the urban heat island effect. Green roofs, sky courts and green walls must be thoughtfully designed to withstand severe conditions such as moisture stress, extremes in temperature, tropical storms and strong desiccating winds. This paper focused on the installation of green wall systems. There are 2 general types of green walls systems, namely facade greening and living walls. Green facades are trellis systems where climbing plants can grow vertically without attaching to the surface of the building. Living walls are part of a building envelope system where plants are actually planted and grown in a wall system. A modular G-SKY Green Wall Panel was installed at the Aquaquest Learning Centre at the Vancouver Aquarium in Stanley Park in September 2006. This green wall panel, which was originally developed in Japan, incorporates many innovative features in the building envelope. It provides an exterior wall covered with 8 species of plants native to the Coastal Temperate Rain Forest. The living wall is irrigated by rainwater collected from the roof, stored in an underground cistern and fed through a drip irrigation system. From a habitat perspective, the building imitates an escarpment. Installation, support systems, irrigation, replacement of modules and maintenance are included in the complete wall system. Living walls reduce the surface temperature of buildings by as much as 10 degrees C when covered with vegetation and a growing medium. The project team is anticipating LEED gold certification under the United States-Canada Green Building Council. It was concluded that this technology of vegetated building envelopes is applicable for acoustical control at airports, biofiltration of indoor air, greywater treatment, and urban agriculture and vertical

  12. DWPF FLOWSHEET STUDIES WITH SIMULANT TO DETERMINE THE IMPACT OF NEXT GENERATION SOLVENT ON THE CPC PROCESS AND GLASS FORMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Newell, J.; Peeler, D.; Edwards, T.; Hay, M.; Stone, M.

    2011-06-29

    As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS), a new strip acid, and modified monosodium titanate (mMST) will be deployed. The NGS is comprised of four components: 0.050 M MaxCalix (extractant), 0.50 M Cs-7SB (modifier), 0.003 M guanidine-LIX-79, with the balance ({approx}74 wt%) being Isopar{reg_sign} L. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing with the next generation solvent and mMST was required to determine the impact of these changes in 512-S and Defense Waste Processing Facility (DWPF) operations, as well as Chemical Process Cell (CPC), glass formulation activities, and melter operations. Because of these changes, experimental testing with the next generation solvent and mMST is required to determine the impact of these changes. A Technical Task Request (TTR) was issued to support the assessments of the impact of the next generation solvent and mMST on the downstream DWPF flowsheet unit. The TTR identified five tasks to be investigated: (1) CPC Flowsheet Demonstration for NGS; (2) Solvent Stability for DWPF CPC Conditions; (3) Glass Formulation Studies; (4) Boron Volatility and Melt Rate; and (5) CPC Flowsheet Demonstration for mMST.

  13. Impact of Nuss procedure on chest wall%Nuss手术治疗漏斗胸对胸廓的影响

    Institute of Scientific and Technical Information of China (English)

    陈诚豪; 曾骐; 张北叶; 彭芸; 张娜; 于洁; 孙记航; 潘岳松

    2013-01-01

    Objective To introduce a new measurement that can be used to evaluate the improvement of the chest wall after Nuss procedure.Methods From April 2004 to March 2008,449 pectus excavatum(PE) patients received Nuss procedure in Hospital,and according to the inclusion criteria,there were 80 cases enrolled our group at last,then divided the cases into two groups,one group of pre-operative of Nuss surgery,and the other group of post-bar removal.All the cases had examination of posterio-anterior chest radiographs before Nuss procedure and after Nuss bar removal.The maximal distance of the outer boundary of each rib pairs (C,from the 1 st pair to the 9th),the distance between lung apex to the costophrenic angle(H)and the distance between the two costophrenic angles (W),were measured.Results All the 80 cases completed the Nuss procedure and Nuss bar removal safely and effectively.All the patients were followed up from 30 to 36 months,and no recurrence or long-term complications occurred.The measured values of post-bar removal group showed significantly increased compare to the group of pre-Nuss procedure.The measured values (rib of 5 th,6th,7th) of post-bar removal group showed statistically significant compare to the group of normal children of the same age group.Conclusion The chest wall of post-bar removal was significantly increased compare to the cases of pre-Nuss procedure.Compare to the group of normal children of the same age group,there may be some restrictions on the thoracic by the pectus bar in the group of pectus,but whether there are still thorax limited,we need further more follow-up and measurement of chest X-ray to clear.%目的 应用简易的胸部X线片测量法评价漏斗胸术后胸廓改善情况,探讨Nuss手术对胸廓的影响及其程度.方法 对我院2004年4月至2008年3月共449例漏斗胸行Nuss手术的患儿进行回顾性分析.根据一定的入选标准,最终人选学龄前期漏斗胸患儿共80例,分成Nuss术前和取出支架

  14. Dynamic buckling of double-walled carbon nanotubes under axial impact loading%轴向冲击载荷作用下双壁碳纳米管的动力屈曲

    Institute of Scientific and Technical Information of China (English)

    姚小虎; 张晓晴; 韩强

    2011-01-01

    Using the modified finite element method, the nonlinear shell-spring finite element model is established with taking the van der waals force into account. Based on the B-R motion criterion, the dynamic bucking behaviors of multi-walled carbon nanotubes are examined systemically. The dynamic critical loads for buckling and failure of double-walled carbon nanotubes under axial impact load are obtained. It is shown that in the dynamic buckling process of multi-walled carbon nanotubes, the deformation of each wall is harmonious to each other and the change of interlayer spacing is very small. The magnitude and the duration of impact load as well as the length of carbon nanotube have greater effects on the dynamic buckling of carbon nanotubes. For the shorter carbon nanotubes, asymmetrical buckling mode appears earlier. The simulations further show that the stress wave propagation in carbon nanotubes induces the asymmetrical buckling mode. In the dynamic buckling process of carbon nanotubes, there are four circumferential lobes that can be observed obviously, and their wave crest and trough of the lobes change alternately.%应用改进的有限元方法,建立考虑层间范德华力作用的壳-弹簧非线性有限元模型,基于B-R运动准则,系统地研究了双壁碳纳米管的动力屈曲问题,得到了轴向冲击载荷作用下双壁碳纳米管的临界动力屈曲载荷和临界动力失效载荷.研究结果表明,在动力屈曲过程中,双壁碳纳米管层间距的变化非常小,各管的变形相互协调;碳纳米管中应力波的传播导致碳纳米管出现非对称屈曲模态,可明显观测到四个环向波瓣,沿着碳纳米管的轴线方向,四个波瓣的波峰和波谷交替变化.对碳纳米管动力屈曲问题的研究表明,冲击载荷的大小和持续时间对碳纳米管的动力屈曲有较大影响,同时碳纳米管的长度对碳纳米管的动力屈曲也有较大的影响,较短的碳纳米管较早出现非对称屈曲模态.

  15. PR-Index: Using the h-Index and PageRank for Determining True Impact.

    Science.gov (United States)

    Gao, Chao; Wang, Zhen; Li, Xianghua; Zhang, Zili; Zeng, Wei

    2016-01-01

    Several technical indicators have been proposed to assess the impact of authors and institutions. Here, we combine the h-index and the PageRank algorithm to do away with some of the individual limitations of these two indices. Most importantly, we aim to take into account value differences between citations-evaluating the citation sources by defining the h-index using the PageRank score rather than with citations. The resulting PR-index is then constructed by evaluating source popularity as well as the source publication authority. Extensive tests on available collections data (i.e., Microsoft Academic Search and benchmarks on the SIGKDD innovation award) show that the PR-index provides a more balanced impact measure than many existing indices. Due to its simplicity and similarity to the popular h-index, the PR-index may thus become a welcome addition to the technical indices already in use. Moreover, growth dynamics prior to the SIGKDD innovation award indicate that the PR-index might have notable predictive power.

  16. Field methods for determining point source pollution impacts in rivers: A case study of the Grindsted stream

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Sonne, Anne Thobo; Fjordbøge, Annika Sidelmann

    2013-01-01

    by two major polluting point sources, Grindsted factory and Grindsted landfill, representing two of the 43 large-scale contaminated sites in Denmark. Our overall aim was therefore to (i) test the applicability of different methods for mapping groundwater pollution as it enters streams at a complex site...... Water Framework Directive requires member states to evaluate all types of contamination sources within a watershed in order to assess their direct impact on water quality. Understanding and accurately characterizing groundwater-surface water interactions (GSI) and groundwater discharge is thus becoming...... an increasingly important activity for the hydrogeological investigations of rivers and streams. In cases where groundwater contaminant plumes are discharging to streams, determination of flow paths and groundwater fluxes are essential for evaluating the transport, fate and potential impact of the plume...

  17. Analysis of the South African input-output table to determine sector specific economic impacts: A study on real estate

    Directory of Open Access Journals (Sweden)

    Douw Gert Brand Boshoff

    2016-11-01

    Full Text Available Input-output analysis is a well known method of analysing specific economic activity and the influence of different sectors on the economy and on one another. This study investigates the ability of input-output analysis to consider the importance of commercial real estate on the economy. It analyses the economic activity, contribution to GDP, employment created and taxes generated with reference to direct, indirect and induced impacts. The research shows the contribution of the specific sector on the economy and highlights the ability of input-output analysis to determine the impact of different types of property and locational analysis. The interaction of property with the economy is discussed, which also enables the use of the analysis reported here for short term future forecasting, whereby expected real estate activity is used to forecast the direct, indirect and induced effects on the economy.

  18. 75 FR 8299 - Draft Environmental Impact Statement; Determination of Regulated Status of Alfalfa Genetically...

    Science.gov (United States)

    2010-02-24

    ... Regulated Status of Alfalfa Genetically Engineered for Tolerance to the Herbicide Glyphosate AGENCY: Animal... and Forage Genetics International alfalfa lines designated as events J101 and J163 as regulated... determination on the status of the Monsanto Company and Forage Genetics International alfalfa lines designated...

  19. 75 FR 1585 - Draft Environmental Impact Statement; Determination of Regulated Status of Alfalfa Genetically...

    Science.gov (United States)

    2010-01-12

    ... Regulated Status of Alfalfa Genetically Engineered for Tolerance to the Herbicide Glyphosate AGENCY: Animal... determination on the status of the Monsanto Company and Forage Genetics International alfalfa lines designated... Monsanto/Forage Genetics International (FGI) alfalfa events J101 and J163 were no longer considered...

  20. New’ Performance Measures: Determinants of Their Use and Their Impact on Performance

    NARCIS (Netherlands)

    F.H.M. Verbeeten (Frank)

    2005-01-01

    textabstractThis study investigates the extent to which Dutch organizations use ‘new’ performance measures to deal with the perceived inadequacies of traditional accounting performance measures. In addition, the determinants of the use of these ‘new’ performance measures are documented; finally, the

  1. Omega-3 Polyunsaturated Fatty Acids: Structural and Functional Effects on the Vascular Wall.

    Science.gov (United States)

    Zanetti, Michela; Grillo, Andrea; Losurdo, Pasquale; Panizon, Emiliano; Mearelli, Filippo; Cattin, Luigi; Barazzoni, Rocco; Carretta, Renzo

    2015-01-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFA) consumption is associated with reduced cardiovascular disease risk. Increasing evidence demonstrating a beneficial effect of n-3 PUFA on arterial wall properties is progressively emerging. We reviewed the recent available evidence for the cardiovascular effects of n-3 PUFA focusing on structural and functional properties of the vascular wall. In experimental studies and clinical trials n-3 PUFA have shown the ability to improve arterial hemodynamics by reducing arterial stiffness, thus explaining some of its cardioprotective properties. Recent studies suggest beneficial effects of n-3 PUFA on endothelial activation, which are likely to improve vascular function. Several molecular, cellular, and physiological pathways influenced by n-3 PUFA can affect arterial wall properties and therefore interfere with the atherosclerotic process. Although the relative weight of different physiological and molecular mechanisms and the dose-response on arterial wall properties have yet to be determined, n-3 PUFA have the potential to beneficially impact arterial wall remodeling and cardiovascular outcomes by targeting arterial wall stiffening and endothelial dysfunction.

  2. Omega-3 Polyunsaturated Fatty Acids: Structural and Functional Effects on the Vascular Wall

    Directory of Open Access Journals (Sweden)

    Michela Zanetti

    2015-01-01

    Full Text Available Omega-3 polyunsaturated fatty acids (n-3 PUFA consumption is associated with reduced cardiovascular disease risk. Increasing evidence demonstrating a beneficial effect of n-3 PUFA on arterial wall properties is progressively emerging. We reviewed the recent available evidence for the cardiovascular effects of n-3 PUFA focusing on structural and functional properties of the vascular wall. In experimental studies and clinical trials n-3 PUFA have shown the ability to improve arterial hemodynamics by reducing arterial stiffness, thus explaining some of its cardioprotective properties. Recent studies suggest beneficial effects of n-3 PUFA on endothelial activation, which are likely to improve vascular function. Several molecular, cellular, and physiological pathways influenced by n-3 PUFA can affect arterial wall properties and therefore interfere with the atherosclerotic process. Although the relative weight of different physiological and molecular mechanisms and the dose-response on arterial wall properties have yet to be determined, n-3 PUFA have the potential to beneficially impact arterial wall remodeling and cardiovascular outcomes by targeting arterial wall stiffening and endothelial dysfunction.

  3. Shear wall ultimate drift limits

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, T.A. [Duffy, (T.A.) Tijeras, NM (United States); Goldman, A. [Goldman, (A.), Sandia, Los Alamos, NM (United States); Farrar, C.R. [Los Alamos National Lab., NM (United States)

    1994-04-01

    Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.

  4. Understanding the Impact of Brain Disorders: Towards a 'Horizontal Epidemiology' of Psychosocial Difficulties and Their Determinants.

    Directory of Open Access Journals (Sweden)

    Alarcos Cieza

    Full Text Available To test the hypothesis of 'horizontal epidemiology', i.e. that psychosocial difficulties (PSDs, such as sleep disturbances, emotional instability and difficulties in personal interactions, and their environmental determinants are experienced in common across neurological and psychiatric disorders, together called brain disorders.A multi-method study involving systematic literature reviews, content analysis of patient-reported outcomes and outcome instruments, clinical input and a qualitative study was carried out to generate a pool of PSD and environmental determinants relevant for nine different brain disorders, namely epilepsy, migraine, multiple sclerosis, Parkinson's disease, stroke, dementia, depression, schizophrenia and substance dependency. Information from these sources was harmonized and compiled, and after feedback from external experts, a data collection protocol including PSD and determinants common across these nine disorders was developed. This protocol was implemented as an interview in a cross-sectional study including a convenience sample of persons with one of the nine brain disorders. PSDs endorsed by at least 25% of patients with a brain disorder were considered associated with the disorder. PSD were considered common across disorders if associated to 5 out of the 9 brain disorders and if among the 5 both neurological and psychiatric conditions were represented.The data collection protocol with 64 PSDs and 20 determinants was used to collect data from a convenience sample of 722 persons in four specialized health care facilities in Europe.57 of the PSDs and 16 of the determinants included in the protocol were found to be experienced across brain disorders.This is the first evidence that supports the hypothesis of horizontal epidemiology in brain disorders. This result challenges the brain disorder-specific or vertical approach in which clinical and epidemiological research about psychosocial difficulties experienced in daily

  5. Evaluating the impact of new observational constraints on P-S/IVOC emissions, multi-generation oxidation, and chamber wall losses on SOA modeling for Los Angeles, CA

    Science.gov (United States)

    Ma, Prettiny K.; Zhao, Yunliang; Robinson, Allen L.; Worton, David R.; Goldstein, Allen H.; Ortega, Amber M.; Jimenez, Jose L.; Zotter, Peter; Prévôt, André S. H.; Szidat, Sönke; Hayes, Patrick L.

    2017-08-01

    Secondary organic aerosol (SOA) is an important contributor to fine particulate matter (PM) mass in polluted regions, and its modeling remains poorly constrained. A box model is developed that uses recently published literature parameterizations and data sets to better constrain and evaluate the formation pathways and precursors of urban SOA during the CalNex 2010 campaign in Los Angeles. When using the measurements of intermediate-volatility organic compounds (IVOCs) reported in Zhao et al. (2014) and of semi-volatile organic compounds (SVOCs) reported in Worton et al. (2014) the model is biased high at longer photochemical ages, whereas at shorter photochemical ages it is biased low, if the yields for VOC oxidation are not updated. The parameterizations using an updated version of the yields, which takes into account the effect of gas-phase wall losses in environmental chambers, show model-measurement agreement at longer photochemical ages, even though some low bias at short photochemical ages still remains. Furthermore, the fossil and non-fossil carbon split of urban SOA simulated by the model is consistent with measurements at the Pasadena ground site. Multi-generation oxidation mechanisms are often employed in SOA models to increase the SOA yields derived from environmental chamber experiments in order to obtain better model-measurement agreement. However, there are many uncertainties associated with these aging mechanisms. Thus, SOA formation in the model is compared to data from an oxidation flow reactor (OFR) in order to constrain SOA formation at longer photochemical ages than observed in urban air. The model predicts similar SOA mass at short to moderate photochemical ages when the aging mechanisms or the updated version of the yields for VOC oxidation are implemented. The latter case has SOA formation rates that are more consistent with observations from the OFR though. Aging mechanisms may still play an important role in SOA chemistry, but the

  6. Determining the relative impact of electrical conductivity and dielectric permittivity on the GPR early-time signal

    Science.gov (United States)

    Algeo, J.; Slater, L. D.; Binley, A. M.; Van Dam, R. L.; Watts, C. W.

    2016-12-01

    We employ early-time amplitude analysis, a recently developed ground-penetrating radar (GPR) methodology, in conjunction with electrical resistivity tomography (ERT) to determine the relative impact of dielectric permittivity and electrical conductivity on the GPR early-time signal (ETS). Early-time amplitude analysis uses changes in the amplitude of the overlapping GPR air- and ground-waves to resolve the electromagnetic properties of the subsurface. It has been employed to assess the water content of geologic materials at laboratory and field scales. As the amplitude of the ETS is dependent on both conductivity and permittivity, both of which can be affected by changes in soil water content, it is important to understand the relative magnitude of the impacts of these two parameters on GPR amplitude. Previous work in this field has related the early-time signal to conductivity and permittivity changes in a field setting, however these variations in electromagnetic properties were caused by changes in both lithology and water content. We carried out an irrigation experiment at the Butt Close and Honey Pot field sites in Woburn, Bedfordshire, UK, managed by Rothamstead Research, to explore how changes in conductivity and permittivity, caused by changes in water content, impact the ETS. Our GPR data provide early-time information and a measurement of permittivity from reflections off of a plow pan layer located at a constant depth in the subsurface. Data from the ERT survey provide a measurement of electrical conductivity. We modified the conductivity and permittivity of the subsurface by irrigating with groundwater. We carry out a multiple regression analysis to determine the relative impacts of changing conductivity and permittivity at the Butt Close and Honey Pot sites, and what effect these changes might have on estimates of soil water content. The results of our investigation help in the development of GPR ETS techniques for mapping and monitoring water content

  7. Determination of mechanical properties of impacted human morsellized cancellous allografts for revision joint arthroplasty.

    Science.gov (United States)

    Tanabe, Y; Wakui, T; Kobayashi, A; Ohashi, H; Kadoya, Y; Yamano, Y

    1999-12-01

    This paper deals with the characterization of mechanical properties of impacted morsellized cancellous allograft (IMCA) produced by dynamic compaction of allograft femoral heads ground by commercially available bone mills, i.e. rotating rasp and reciprocating type bone mills. Various ranges and profiles of particle size in the graft aggregates were obtained using these bone mills, and the effect of number of compaction as well as the distribution of particle sizes on the mechanical properties of IMCA under quasistatic compression and shear loading conditions was discussed. The morsellized cancellous allograft prepared by the reciprocating type bone mill showed a broad distribution of particle sizes, and gave IMCA superior mechanical properties to the graft with a more uniform size distribution, or prepared by the rotating rasp type bone mills. The increase of number of compaction also improved the mechanical properties of IMCA in compression.

  8. Genetic Variability Overrides the Impact of Parental Cell Type and Determines iPSC Differentiation Potential

    Directory of Open Access Journals (Sweden)

    Aija Kyttälä

    2016-02-01

    Full Text Available Reports on the retention of somatic cell memory in induced pluripotent stem cells (iPSCs have complicated the selection of the optimal cell type for the generation of iPSC biobanks. To address this issue we compared transcriptomic, epigenetic, and differentiation propensities of genetically matched human iPSCs derived from fibroblasts and blood, two tissues of the most practical relevance for biobanking. Our results show that iPSC lines derived from the same donor are highly similar to each other. However, genetic variation imparts a donor-specific expression and methylation profile in reprogrammed cells that leads to variable functional capacities of iPSC lines. Our results suggest that integration-free, bona fide iPSC lines from fibroblasts and blood can be combined in repositories to form biobanks. Due to the impact of genetic variation on iPSC differentiation, biobanks should contain cells from large numbers of donors.

  9. The Chicxulub Impact Crater and Oblique Impact

    Science.gov (United States)

    McDonald, M.; Gulick, S.; Melosh, H.; Christeson, G.

    2007-05-01

    Determining whether or not the Chicxulub impact was oblique (<45 degrees) will aid in our understanding of the environmental consequences 65 Ma. Planetary impact events, and impact simulations in the laboratory, show that oblique impacts have clear asymmetric ejecta distributions. However, the subsurface structures of the resultant craters are not well understood. In 2005, we acquired 1822 km of seismic reflection data onboard the R/V Maurice Ewing imaging the massive (200+ km) Chicxulub impact crater. The seismic profiles show that pre- crater stratigraphy outside the central basin of the Chicxulub impact crater is offset downward into the crater marking the post-impact slumping and formation of the terrace zone. The inward collapse of the Chicxulub terrace zone coincides with the outward collapse of the central uplift to form the peak ring. Chicxulub's peak ring is offset to the southeast, away from the deepest terrace zone mapped in the seismic data, suggesting that its peak ring was offset toward a more gradual wall of the transient cavity. Peak ring offsets, relative to crater center, of Venusian craters from radar images in the Magellan data set allow us to determine whether there are systematic variations in peak ring offset due to oblique impact. Ten pristine Venusian peak ring craters formed by oblique impact show that peak rings are offset both uprange and downrange, suggesting that peak ring position, and related subsurface asymmetries in the terrace zone, do not provide information about impact obliquity. This analysis supports the idea that Chicxulub's peak ring offset is a consequence of target properties and pre-impact structure and independent of impact trajectory.

  10. Método para a Determinação de Ácidos Fenólicos na Parede Celular de Forragens Method for Phenolic Acid Determination in Forage Cell Wall

    Directory of Open Access Journals (Sweden)

    Francisco Carlos Deschamps

    2002-07-01

    be facilitated by the availability of sensible methods that permit processing large amounts of samples. The present paper describes a method for determining phenolic acids in forage cell wall through high-performance liquid chromatography (HPLC. Sugar cane bagasse, elephant grass and cassava leaves were used as experimental samples. To remove soluble low molecular weight products, ethanol 80% and neutral detergent were essayed to determine their effects on the recovery of molecules and other benefits to chromatography profile. The sample solubilization with NaOH 1 mol/L, 20ºC for 24 hours, was used to obtain the free phenolic acids. The method described proved appropriate showing great sensibility and lab productivity. To minimize the effects of salt formation as a consequence of acid neutralization, sample dilution and reduced injection volumes (5uL are suggested. The action of ethanol 80% and neutral detergent differ between grasses and legumes. The amount of extractives in cassava leaves was greater than in other materials.The method described in the present paper is an important tool to study phenolic acids in tropical forage cell wall.

  11. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, A.C.W.(L.)

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful, a

  12. Domain wall filters

    CERN Document Server

    Bär, O; Neuberger, H; Witzel, O; Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-01-01

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  13. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  14. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, A.C.W.(L.)

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful,

  15. Optimizing {sup 18}F-FDG PET/CT imaging of vessel wall inflammation: the impact of {sup 18}F-FDG circulation time, injected dose, uptake parameters, and fasting blood glucose levels

    Energy Technology Data Exchange (ETDEWEB)

    Bucerius, Jan [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); University Hospital, RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany); Mani, Venkatesh; Fayad, Zahi A. [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Moncrieff, Colin [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Machac, Josef [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Farkouh, Michael E. [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Cardiovascular Imaging Clinical Trials Unit, New York, NY (United States); Tawakol, Ahmed [Massachusetts General Hospital, Harvard University, Cardiac MR PET CT Program, Boston, MA (United States); Rudd, James H.F. [Cambridge University, Division of Cardiovascular Medicine, Cambridge (United Kingdom)

    2014-02-15

    {sup 18}F-FDG PET is increasingly used for imaging of vessel wall inflammation. However, limited data are available on the impact of methodological variables, i.e. prescan fasting glucose, FDG circulation time and injected FDG dose, and of different FDG uptake parameters, in vascular FDG PET imaging. Included in the study were 195 patients who underwent vascular FDG PET/CT of the aorta and the carotids. Arterial standardized uptake values ({sub mean}SUV{sub max}), target-to-background ratios ({sub mean}TBR{sub max}) and FDG blood-pool activity in the superior vena cava (SVC) and the jugular veins (JV) were quantified. Vascular FDG uptake values classified according to the tertiles of prescan fasting glucose levels, the FDG circulation time, and the injected FDG dose were compared using ANOVA. Multivariate regression analyses were performed to identify the potential impact of all variables described on the arterial and blood-pool FDG uptake. Tertile analyses revealed FDG circulation times of about 2.5 h and prescan glucose levels of less than 7.0 mmol/l, showing a favorable relationship between arterial and blood-pool FDG uptake. FDG circulation times showed negative associations with aortic{sub mean}SUV{sub max} values as well as SVC and JV FDG blood-pool activity, but positive correlations with aortic and carotid{sub mean}TBR{sub max} values. Prescan glucose levels were negatively associated with aortic and carotid{sub mean}TBR{sub max} and carotid{sub mean}SUV{sub max} values, but were positively correlated with SVC blood-pool uptake. The injected FDG dose failed to show any significant association with vascular FDG uptake. FDG circulation times and prescan blood glucose levels significantly affect FDG uptake in the aortic and carotid walls and may bias the results of image interpretation in patients undergoing vascular FDG PET/CT. The injected FDG dose was less critical. Therefore, circulation times of about 2.5 h and prescan glucose levels less than 7.0 mmol

  16. Hard and soft walls

    CERN Document Server

    Milton, Kimball A

    2011-01-01

    In a continuing effort to understand divergences which occur when quantum fields are confined by bounding surfaces, we investigate local energy densities (and the local energy-momentum tensor) in the vicinity of a wall. In this paper, attention is largely confined to a scalar field. If the wall is an infinite Dirichlet plane, well known volume and surface divergences are found, which are regulated by a temporal point-splitting parameter. If the wall is represented by a linear potential in one coordinate $z$, the divergences are softened. The case of a general wall, described by a potential of the form $z^\\alpha$ for $z>0$ is considered. If $\\alpha>2$, there are no surface divergences, which in any case vanish if the conformal stress tensor is employed. Divergences within the wall are also considered.

  17. Distorted, non-spherical transiting planets: impact on the transit depth and on the radius determination

    CERN Document Server

    Leconte, Jérémy; Chabrier, Gilles

    2011-01-01

    We quantify the systematic impact of the non-spherical shape of transiting planets and brown dwarfs, due to tidal forces and rotation, on the observed transit depth. Such a departure from sphericity leads to a bias in the derivation of the transit radius from the light curve and affects the comparison with planet structure and evolution models which assume spherical symmetry. As the tidally deformed planet projects its smallest cross section area during the transit, the measured effective radius is smaller than the one of the unperturbed spherical planet. This effect can be corrected by calculating the theoretical shape of the observed planet. We derive simple analytical expressions for the ellipsoidal shape of a fluid object (star or planet) accounting for both tidal and rotational deformations and calibratre it with fully numerical evolution models in the 0.3Mjup-75Mjup mass range. Our calculations yield a 20% effect on the transit depth, i.e. a 10% decrease of the measured radius, for the extreme case of a...

  18. Using Attainment of the Designated Aquatic Life Use to Determine Adverse Environmental Impact

    Directory of Open Access Journals (Sweden)

    Greg Seegert

    2002-01-01

    Full Text Available Section 316(b of the Clean Water Act requires that cooling-water intake structures (CWIS use Best Technology Available (BTA to minimize adverse environmental impacts (AEI. The U.S. EPA has not defined AEI, and there is no clear consensus regarding its definition. Nonetheless, operational definitions are necessary to evaluate design alternatives and to measure the success of mitigative measures. Rather than having to develop measures of aquatic health that are highly site-specific, controversial, and often unlikely to elicit agreement from all sides of the environmental “fence”, it may be more productive to use existing ecological assessment tools. Aquatic Life Uses (ALU already provide a regulatory framework to assess the quality (health of the aquatic community in various habitats (e.g., warmwater habitat, exceptional warmwater habitat. Attainment of the ALU indicates that further point source controls are unnecessary, whereas nonattainment indicates that those pollutants or stressors causing the nonattainment must be reduced. A similar approach for existing water intakes is recommended. That is, attainment of the designated ALU will be taken as an indication that there is no AEI. Although attainment of the ALU may not be a foolproof indicator of a lack of AEI, this approach seems more reasonable that using scarce monetary resources to fix problems that likely do not exist, or having both regulators and the regulated community expend their resources debating whether various observed biological responses do or do not constitute AEI.

  19. The determinants of defensive medicine in Italian hospitals: The impact of being a second victim.

    Science.gov (United States)

    Panella, M; Rinaldi, C; Leigheb, F; Donnarumma, C; Kul, S; Vanhaecht, K; Di Stanislao, F

    2016-07-01

    Defensive medicine affects healthcare systems worldwide. The concerns and perception about medical liability could lead practitioners to practise defensive medicine. Second victim is a healthcare worker involved in an unanticipated adverse patient event. The role of being second victim and the other possible determinants for defensive medicine is mostly unclear. To study the condition of being second victim as a possible determinants of defensive medicine among Italian hospital physicians. A secondary analysis of the database of the national survey study on the prevalence and the costs of defensive medicine in Italy that was carried out between April 2014 and June 2014 in 55 Italian hospitals was performed for this study. The demographic section of the questionnaire was selected including the physician's age, gender, specialty, activity volume, grade and the variable being a second victim after an adverse event. A total sample of 1313 physicians (87.5% response rate) was used in the data analyses. Characteristics of the participants included a mean age 49.2 of years and 19.4 average years of experience. The most prominent predictor for practising defensive medicine was the physicians' experience of being a second victim after an adverse event (OR=1.88; 95%CI, 1.38-2.57). Other determinants included age, years of experience, activity volume and risk of specialty. Malpractice reform, effective support to second victims in hospitals together with a systematic use of evidence-based clinical guidelines, emerged as possible recommendations for reducing defensive medicine. Copyright © 2016 SECA. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Determination of non-steroidal anti-inflammatory drugs in water samples by solid-phase microextraction based sol-gel technique using poly(ethylene glycol) grafted multi-walled carbon nanotubes coated fiber.

    Science.gov (United States)

    Sarafraz-Yazdi, Ali; Amiri, Amirhassan; Rounaghi, Gholamhossein; Eshtiagh-Hosseini, Hossein

    2012-03-30

    In this study, poly(ethylene glycol) (PEG) grafted multi-walled carbon nanotubes (PEG-g-MWCNTs) were synthesized by the covalent functionalization of MWCNTs with hydroxyl-terminated PEG chains. PEG-g-MWCNTs was used as a novel stationary phase to prepare the sol-gel solid-phase microextraction (SPME) fiber in combination with gas chromatography-flame ionization detector (GC-FID) for the determination of ibuprofen, naproxen and diclofenac in real water samples. Some parameters which influencing the extraction efficiency were such as desorption temperature and time, extraction temperature and time, pH, salt effect and stirring speed that were investigated and optimized. Under the optimal conditions, the method detection limits (S/N=3) were in the range of 0.007-0.03 ng mL(-1) and the limits of quantification (S/N=10) between 0.05 and 0.07 ng mL(-1). The relative standard deviations (RSDs) for one fiber (repeatability) (n=5) were obtained from 5.9 up to 8.1% and between fibers or batch to batch (n=3) (reproducibility) in the range of 7.2-9.1%. The developed method was successfully applied to real water samples while the relative recovery percentages obtained for the spiked water samples at 0.2 ng mL(-1) were from 84 to 107%.

  1. Iron nanoparticles decorated multi-wall carbon nanotubes modified carbon paste electrode as an electrochemical sensor for the simultaneous determination of uric acid in the presence of ascorbic acid, dopamine and L-tyrosine.

    Science.gov (United States)

    Bhakta, Arvind K; Mascarenhas, Ronald J; D'Souza, Ozma J; Satpati, Ashis K; Detriche, Simon; Mekhalif, Zineb; Dalhalle, Joseph

    2015-12-01

    Iron nanoparticles decorated multi-wall carbon nanotubes modified carbon paste electrode (Fe-MWCNTs/MCPE) was prepared by bulk-modification method. The electrochemical impedance spectroscopy (EIS) suggests least charge transfer resistance at the modified electrode. The electrochemical behavior of UA was studied in 0.1M phosphate buffer solution (PBS) of pH3.0 using cyclic voltammetry (CV) while differential pulse voltammetry (DPV) was used for quantification. The spectroelectrochemial study of oxidation of UA at Fe-MWCNTs/MCPE showed a decrease in the absorbance of two peaks with time, which are ascribed to π to π(⁎) and n to π(⁎) transitions. Under optimum condition, the DPV response offered two linear dynamic ranges for UA in the concentration range 7.0×10(-8)M-1.0×10(-6)M and 2.0×10(-6)M-1.0×10(-5)M with detection limit (4.80±0.35)×10(-8)M (S/N=3). The practical analytical application of this sensor was successfully evaluated by determination of spiked UA in clinical samples, such as human blood serum and urine with good percentage recovery. The proposed electrochemical sensor offers a simple, reliable, rapid, reproducible and cost effective analysis of a quaternary mixture of biomolecules containing AA, DA, UA and Tyr which was free from mutual interferences.

  2. Determination of type A trichothecenes in coix seed by magnetic solid-phase extraction based on magnetic multi-walled carbon nanotubes coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Dong, Maofeng; Si, Wenshuai; Wang, Weimin; Bai, Bing; Nie, Dongxia; Song, Weiguo; Zhao, Zhihui; Guo, Yirong; Han, Zheng

    2016-09-01

    Magnetic solid-phase extraction (m-SPE) is a promising sample preparation approach due to its convenience, speed, and simplicity. For the first time, a rapid and reliable m-SPE approach using magnetic multi-walled carbon nanotubes (m-MWCNTs) as the adsorbent was proposed for purification of type A trichothecenes including T-2 toxins (T2), HT-2 toxins (HT-2), diacetoxyscirpenol (DAS), and neosolaniol (NEO) in coix seed. The m-MWCNTs were synthesized by assembling the magnetic nanoparticles (Fe3O4) with MWCNTs by sonication through an aggregation wrap mechanism, and characterized by transmission electron microscope. Several key parameters affecting the performance of the procedure were extensively investigated including extraction solutions, desorption solvents, and m-MWCNT amounts. Under the optimal sample preparation conditions followed by analysis with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), high sensitivity (limit of quantification in the range of 0.3-1.5 μg kg(-1)), good linearity (R (2) > 0.99), satisfactory recovery (73.6-90.6 %), and acceptable precision (≤2.5 %) were obtained. The analytical performance of the developed method has also been successfully evaluated in real coix seed samples. Graphical Abstract Flow chart of determination of type A trichothecenes in coix seed by magnetic solid-phase extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry.

  3. Multi-walled carbon nanotubes and metal-organic framework nanocomposites as novel hybrid electrode materials for the determination of nano-molar levels of lead in a lab-on-valve format.

    Science.gov (United States)

    Wang, Yang; Wu, Yichun; Xie, Jing; Ge, Huali; Hu, Xiaoya

    2013-09-07

    Metal-organic frameworks have been the subject of intense research because of their unique physicochemical properties. The presented study investigates the application of multi-wall carbon nanotubes and metal-organic frameworks (MWCNTs@Cu3(BTC)2) nanoparticles-modified electrode for the determination of trace levels of lead. The nanocomposites were prepared by solvothermal synthesis and characterized in detail. The experimental procedure was carried out by accumulating lead on the electrode surface and subsequently measuring with differential pulse anodic stripping voltammetry in a lab-on-valve format. The main parameters affecting the analytical performance, including the amount of MWCNTs@Cu3(BTC)2 suspension, supporting electrolyte and its pH, stripping mode, and flow rate, have been investigated in detail. Under the optimum conditions, the oxidation peak current displayed a calibration response for lead over a concentration range from 1.0 × 10(-9) to 5.0 × 10(-8) mol L(-1) with a excellent detection limit of 7.9 × 10(-10) mol L(-1). The relative standard deviation of 7 successive scans was 3.10% for 1.0 × 10(-8) mol L(-1) lead. The established method showed a great improvement in sensitivity and sample throughput for lead analysis.

  4. Multi-residue determination of 171 pesticides in cowpea using modified QuEChERS method with multi-walled carbon nanotubes as reversed-dispersive solid-phase extraction materials.

    Science.gov (United States)

    Han, Yongtao; Song, Le; Zou, Nan; Chen, Ronghua; Qin, Yuhong; Pan, Canping

    2016-09-15

    A rapid and sensitive method for the determination of 171 pesticides in cowpea was developed using multi-walled carbon nanotubes (MWCNTs) as reversed-dispersive solid-phase (r-DSPE) extraction materials. The clean-up performance of MWCNTs was proved to be obviously superior to PSA and GCB. This method was validated on cowpea spiked at 0.01 and 0.1mgkg(-1) with five replicates. The mean recoveries for 169 pesticides ranged from 74% to 129% with relative standard deviations (RSDs) (n=5) lower than 16.4%, except diflufenican and quizalofop-ethyl. Good linearity for all pesticides was obtained with the calibration curve coefficients (R(2)) larger than 0.9970. The limit of detection (LODs) and limit of quantification (LOQs) for the 171 pesticides ranged from 0.001 to 0.003mgkg(-1) and from 0.002 to 0.009mgkg(-1), respectively. The method was demonstrated to be reliable and sensitive for the routine monitoring of the 171 pesticides in cowpea samples.

  5. Impacts of talent development environments on athlete burnout: a self-determination perspective.

    Science.gov (United States)

    Li, Chunxiao; Wang, Chee Keng John; Pyun, Do Young

    2017-09-01

    Guided by Deci and Ryan's (2000) self-determination theory, this survey study aimed to examine the effects of the talent development environmental factors on athlete burnout. Talented adolescent athletes (n = 691) filled out a survey form measuring the talent development environmental factors, needs satisfaction and burnout. The findings showed that three talent environmental factors (i.e., long-term development focus, holistic quality preparation and communication) were negative predictors of burnout via needs satisfaction. It was concluded that the three talent development environmental factors may be important for facilitating athletes' needs satisfaction and preventing burnout.

  6. Electromagnetic approaches to wall characterization, wall mitigation, and antenna design for through-the-wall radar systems

    Science.gov (United States)

    Thajudeen, Christopher

    Through-the-wall imaging (TWI) is a topic of current interest due to its wide range of public safety, law enforcement, and defense applications. Among the various available technologies such as, acoustic, thermal, and optical imaging, which can be employed to sense and image targets of interest, electromagnetic (EM) imaging, in the microwave frequency bands, is the most widely utilized technology and has been at the forefront of research in recent years. The primary objectives for any Through-the-Wall Radar Imaging (TWRI) system are to obtain a layout of the building and/or inner rooms, detect if there are targets of interest including humans or weapons, determine if there are countermeasures being employed to further obscure the contents of a building or room of interest, and finally to classify the detected targets. Unlike conventional radar scenarios, the presence of walls, made of common construction materials such as brick, drywall, plywood, cinder block, and solid concrete, adversely affects the ability of any conventional imaging technique to properly image targets enclosed within building structures as the propagation through the wall can induce shadowing effects on targets of interest which may result in image degradation, errors in target localization, and even complete target masking. For many applications of TWR systems, the wall ringing signals are strong enough to mask the returns from targets not located a sufficient distance behind the wall, beyond the distance of the wall ringing, and thus without proper wall mitigation, target detection becomes extremely difficult. The results presented in this thesis focus on the development of wall parameter estimation, and intra-wall and wall-type characterization techniques for use in both the time and frequency domains as well as analysis of these techniques under various real world scenarios such as reduced system bandwidth scenarios, various wall backing scenarios, the case of inhomogeneous walls, presence

  7. Role of Titanium in Thin Wall Vermicular Graphite Iron Castings Production

    Directory of Open Access Journals (Sweden)

    M. Górny

    2013-04-01

    Full Text Available In this paper the effects of titanium addition in an amount up to 0.13 wt.% have been investigated to determine their effect on the microstructure and mechanical properties of Thin Wall Vermicular Graphite Iron Castings (TWVGI. The study was performed for thinwalled iron castings with 3-5 mm wall thickness and for the reference casting with 13 mm. Microstructural changes were evaluated by analyzing quantitative data sets obtained by image analyzer and also using scanning electron microscope (SEM. Metallographic examinations show that in thin-walled castings there is a significant impact of titanium addition to vermicular graphite formation. Thinwalled castings with vermicular graphite have a homogeneous structure, free of chills, and good mechanical properties. It may predispose them as a potential use as substitutes for aluminum alloy castings in diverse applications.

  8. Current concepts of IgE regulation and impact of genetic determinants.

    Science.gov (United States)

    Potaczek, D P; Kabesch, M

    2012-06-01

    Immunoglobulin E (IgE) mediated immune responses seem to be directed against parasites and neoplasms, but are best known for their involvement in allergies. The IgE network is tightly controlled at different levels as outlined in this review. Genetic determinants were suspected to influence IgE regulation and IgE levels considerably for many years. Linkage and candidate gene studies suggested a number of loci and genes to correlate with total serum IgE levels, and recently genome-wide association studies (GWAS) provided the power to identify genetic determinants for total serum IgE levels: 1q23 (FCER1A), 5q31 (RAD50, IL13, IL4), 12q13 (STAT6), 6p21.3 (HLA-DRB1) and 16p12 (IL4R, IL21R). In this review, we analyse the potential role of these GWAS hits in the IgE network and suggest mechanisms of how genes and genetic variants in these loci may influence IgE regulation.

  9. The Determinants of FDI in the Central and Eastern Europe: The Impact of the European Integration

    Directory of Open Access Journals (Sweden)

    Hanna Makhavikova

    2015-05-01

    Full Text Available The amount of FDI inflows to the Central and Eastern Europe increased dramatically during the last two decades. This article is aimed at identifying the ability of the Central Eastern European countries to attract FDI in the context of European integration, and at estimating the most important factors that influence the decision of foreign investors to invest in the region. Despite the broad research has been devoted to define the FDI determinants, the literature dealing in particular with the role of the European Union in the mobilization of FDI is rather scarce, and these findings are very discrepant. In order to understand factors that influence the location of FDI, we employ an empirical model for the period of 1992-2013 for twenty CEE countries. This study reveals that the most important determinants of FDI in CEECs are the market size, cost of labor and the European integration. The results of the research can be used to estimate the effect on FDI inflows from a prospective additional Eastern expansion of the EU by the countries currently not within the EU.

  10. Identifying the impact of social determinants of health on disease rates using correlation analysis of area-based summary information.

    Science.gov (United States)

    Song, Ruiguang; Hall, H Irene; Harrison, Kathleen McDavid; Sharpe, Tanya Telfair; Lin, Lillian S; Dean, Hazel D

    2011-01-01

    We developed a statistical tool that brings together standard, accessible, and well-understood analytic approaches and uses area-based information and other publicly available data to identify social determinants of health (SDH) that significantly affect the morbidity of a specific disease. We specified AIDS as the disease of interest and used data from the American Community Survey and the National HIV Surveillance System. Morbidity and socioeconomic variables in the two data systems were linked through geographic areas that can be identified in both systems. Correlation and partial correlation coefficients were used to measure the impact of socioeconomic factors on AIDS diagnosis rates in certain geographic areas. We developed an easily explained approach that can be used by a data analyst with access to publicly available datasets and standard statistical software to identify the impact of SDH. We found that the AIDS diagnosis rate was highly correlated with the distribution of race/ethnicity, population density, and marital status in an area. The impact of poverty, education level, and unemployment depended on other SDH variables. Area-based measures of socioeconomic variables can be used to identify risk factors associated with a disease of interest. When correlation analysis is used to identify risk factors, potential confounding from other variables must be taken into account.

  11. Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas.

    Science.gov (United States)

    Ramkat, Rose C; Calari, Alberto; Maghuly, Fatemeh; Laimer, Margit

    2011-08-03

    Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA) for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA) were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV), Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya) contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV) and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a) primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b) primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully.

  12. Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

    Directory of Open Access Journals (Sweden)

    Maghuly Fatemeh

    2011-08-01

    Full Text Available Abstract Background Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. Results A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV, Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Conclusion Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully.

  13. Interspecies interactions determine the impact of the gut microbiota on nutrient allocation in Drosophila melanogaster.

    Science.gov (United States)

    Newell, Peter D; Douglas, Angela E

    2014-01-01

    The animal gut is perpetually exposed to microorganisms, and this microbiota affects development, nutrient allocation, and immune homeostasis. A major challenge is to understand the contribution of individual microbial species and interactions among species in shaping these microbe-dependent traits. Using the Drosophila melanogaster gut microbiota, we tested whether microbe-dependent performance and nutritional traits of Drosophila are functionally modular, i.e., whether the impact of each microbial taxon on host traits is independent of the presence of other microbial taxa. Gnotobiotic flies were constructed with one or a set of five of the Acetobacter and Lactobacillus species which dominate the gut microbiota of conventional flies (Drosophila with untreated microbiota). Axenic (microbiota-free) flies exhibited prolonged development time and elevated glucose and triglyceride contents. The low glucose content of conventional flies was recapitulated in gnotobiotic Drosophila flies colonized with any of the 5 bacterial taxa tested. In contrast, the development rates and triglyceride levels in monocolonized flies varied depending on the taxon present: Acetobacter species supported the largest reductions, while most Lactobacillus species had no effect. Only flies with both Acetobacter and Lactobacillus had triglyceride contents restored to the level in conventional flies. This could be attributed to two processes: Lactobacillus-mediated promotion of Acetobacter abundance in the fly and a significant negative correlation between fly triglyceride content and Acetobacter abundance. We conclude that the microbial basis of host traits varies in both specificity and modularity; microbe-mediated reduction in glucose is relatively nonspecific and modular, while triglyceride content is influenced by interactions among microbes.

  14. Impact of Ionosphere on GPS-based Precise Orbit Determination of Low Earth Orbiters

    Science.gov (United States)

    Arnold, D.; Jaeggi, A.; Beutler, G.; Meyer, U.; Schaer, S.

    2015-12-01

    Deficiencies in geodetic products derived from the orbital trajectories of Low Earth Orbiting (LEO) satellites determined by GPS-based Precise Orbit Determination (POD) were identified in recent years. The precise orbits of the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) mission are, e.g., severely affected by an increased position noise level over the geomagnetic poles and spurious signatures along the Earth's geomagnetic equator (see Fig. 1, which shows the carrier phase residuals of a reduced-dynamic orbit determination for GOCE in m). Such degradations may directly map into the gravity fields recovered from the orbits. They are related to a disturbed GPS signal propagation through the Earth's ionosphere and indicate that the GPS observation model and/or the data pre-processing need to be improved. While GOCE was the first mission where severe ionosphere-related problems became obvious, the GPS-based LEO POD of satellites of the more recent missions Swarm and Sentinel-1A turn out to be affected, as well. We characterize the stochastic and systematic behavior of the ionosphere by analyzing GPS data collected by the POD antennas of various LEO satellites covering a broad altitude range (e.g., GRACE, GOCE and Swarm) and for periods covering significant parts of an entire solar cycle, which probe substantially different ionosphere conditions. The information may provide the basis for improvements of data pre-processing to cope with the ionosphere-induced problems of LEO POD. The performance of cycle slip detection can, e.g., be degraded by large changes of ionospheric refraction from one measurement epoch to the next. Geographically resolved information on the stochastic properties of the ionosphere above the LEOs provide more realistic threshold values for cycle slip detection algorithms. Removing GPS data showing large ionospheric variations is a crude method to mitigate the ionosphere-induced artifacts in orbit and gravity field products

  15. Determination of the fatigue behaviour of thin hard coatings using the impact test and a FEM simulation

    Energy Technology Data Exchange (ETDEWEB)

    Bouzakis, K.D. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Vidakis, N. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Leyendecker, T. [CemeCon, 52068 Aachen (Germany); Lemmer, O. [CemeCon, 52068 Aachen (Germany); Fuss, H.G. [CemeCon, 52068 Aachen (Germany); Erkens, G. [CemeCon, 52068 Aachen (Germany)

    1996-12-15

    The impact test, in combination with a finite element method (FEM) simulation, is used to determine stress values that characterise the fatigue behaviour of thin hard coatings, such as TiAlN, TiAlCN, CrN, MoN, etc. The successive impacts of a cemented carbide ball onto a coated probe induce high contact loads, which can vary in amplitude and cause plastic deformation in the substrate. In the present paper FEM calculations are used in order to determine the critical stress values, which lead to coating fatigue failure. The parametric FEM simulation developed considers elastic behaviour for the coating and elastic plastic behaviour for the substrate. The results of the FEM calculations are correlated to experimental data, as well as to SEM observations of the imprints and to microspectrum analyses within the contact region. Herewith, critical values for various stress components, which are responsible for distinctive fatigue failure modes of the coating-substrate compounds can be obtained. (orig.)

  16. TOURISM SATELLITE ACCOUNT - STATISTICAL METHOD FOR DETERMINING THE ECONOMIC IMPACT OF TOURISM

    Directory of Open Access Journals (Sweden)

    OANA MARIA MILEA

    2012-05-01

    Full Text Available The permanent concerns of analysts to determine how accurately the real economic benefits of tourism, not stopping at only the direct costs of international and domestic visitors but to consider their indirect effects have made them believe that tourism statistics are not comprehensive enough.This is both because they fail to provide a concrete or in respect of costs incurred by tourists on their own and to some extent to those seeking semi-organized tourism and because the economic effects of spending tourist receipts go beyond statistics reported by service providers. As a result, the World Tourism Organization (UNWTO in collaboration with the World Travel and Tourism Council (WTTO, the European Union Statistical Office (EUROSTST and other regional statistical bodies initiated the Tourism Satellite Account system, UNWTO recommending its adoption by all countries.

  17. Determination of rotundone, the pepper aroma impact compound, in grapes and wine.

    Science.gov (United States)

    Siebert, Tracey E; Wood, Claudia; Elsey, Gordon M; Pollnitz, Alan P

    2008-05-28

    Shiraz, also known as Syrah or Hermitage, is one of Australia's most popular red wine varieties both domestically and internationally. Black pepper aroma and flavor are important to some Australian Shiraz red wine styles. Recently, rotundone (a bicyclic sesquiterpene) was identified as the potent aroma compound responsible for pepper aromas in grapes, wine, herbs, and spices, including peppercorns. Here the development, optimization, and validation of the analytical method for the quantitative determination of rotundone in grapes and wine are described and discussed. The method is precise, accurate, robust, and sensitive with a subpart per trillion limit of quantitation. The method uses stable isotope dilution analysis with d(5)-rotundone as internal standard, solid-phase extraction and microextraction, and gas chromatography-mass spectrometry.

  18. The impact of education on wage determination between workers in southern and central-northern Italy

    Directory of Open Access Journals (Sweden)

    Agovino Massimiliano

    2016-01-01

    Full Text Available The aim of this paper is to examine the earnings dynamic in Italy, in order to explain earnings differences between southern Italy and centralnorthern Italy. In our analysis we use different techniques: ordinary least squares (OLS, quantile regression models and the algorithm developed by Machado and Mata (2005. In particular, the Machado and Mata (2005 algorithm allows us to examine the relative importance of both differences in workers’ characteristics and in their returns in explaining southern, central and northern Italy earnings differences at a point in time, as well as across time within each macro-area. We focus on the role of differences in educational endowment and returns to education, one of the most important components of human capital in the stylised literature. The level of education determines the substantial disparities in terms of wage returns. However, this holds only for levels of education related to compulsory education.

  19. Determining the impact of computer-aided control of educational achievements for the health of students

    Directory of Open Access Journals (Sweden)

    Savonova A.V.

    2013-06-01

    Full Text Available The problem of the health of students during the control of knowledge on the example of studying valeological disciplines. In the experiment involved 186 students. Age 17-19 years. The positive effect of regular thematic automated monitoring the health of students. In particular, during unit of knowledge and at exam time. Showed a statistically significant reduction in the average level of reactive anxiety in students of the experimental group, compared to its initial values (before the final test, it fell by 37.91. For comparison, before final testing of the control group, it only reduced by 10.42%. It was determined that a regular automated testing knowledge can be used to organize healthkeeping support professional development of future teachers.

  20. Phase Error Modeling and Its Impact on Precise Orbit Determination of GRACE Satellites

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    Jia Tu

    2012-01-01

    Full Text Available Limiting factors for the precise orbit determination (POD of low-earth orbit (LEO satellite using dual-frequency GPS are nowadays mainly encountered with the in-flight phase error modeling. The phase error is modeled as a systematic and a random component each depending on the direction of GPS signal reception. The systematic part and standard deviation of random part in phase error model are, respectively, estimated by bin-wise mean and standard deviation values of phase postfit residuals computed by orbit determination. By removing the systematic component and adjusting the weight of phase observation data according to standard deviation of random component, the orbit can be further improved by POD approach. The GRACE data of 1–31 January 2006 are processed, and three types of orbit solutions, POD without phase error model correction, POD with mean value correction of phase error model, and POD with phase error model correction, are obtained. The three-dimensional (3D orbit improvements derived from phase error model correction are 0.0153 m for GRACE A and 0.0131 m for GRACE B, and the 3D influences arisen from random part of phase error model are 0.0068 m and 0.0075 m for GRACE A and GRACE B, respectively. Thus the random part of phase error model cannot be neglected for POD. It is also demonstrated by phase postfit residual analysis, orbit comparison with JPL precise science orbit, and orbit validation with KBR data that the results derived from POD with phase error model correction are better than another two types of orbit solutions generated in this paper.

  1. Impact of income inequality and other social determinants on suicide rate in Brazil.

    Directory of Open Access Journals (Sweden)

    Daiane Borges Machado

    Full Text Available PURPOSE: To analyze whether income inequality and other social determinants are associated with suicide rate in Brazil. METHOD: This study used panel data from all 5,507 Brazilian municipalities from 2000 to 2011. Suicide rates were calculated by sex and standardized by age for each municipality and year. The independent variables of the regression model included the Gini Index, per capita income, percentage of individuals with up to eight years of education, urbanization, average number of residents per household, percentage of divorced people, of Catholics, Pentecostals, and Evangelicals. A multivariable negative binomial regression for panel data with fixed-effects specification was performed. RESULTS: The Gini index was positively associated with suicide rates; the rate ratio (RR was 1.055 (95% CI: 1.011-1.101. Of the other social determinants, income had a significant negative association with suicide rates (RR: 0.968, 95% CI: 0.948-0.988, whereas a low-level education had a positive association (RR: 1.015, 95% CI: 1.010-1.021. CONCLUSIONS: Income inequality represents a community-level risk factor for suicide rates in Brazil. The decrease in income inequality, increase in income per capita, and decrease in the percentage of individuals who did not complete basic studies may have counteracted the increase in suicides in the last decade. Other changes, such as the decrease in the mean residents per household, may have contributed to their increase. Therefore, the implementation of social policies that may improve the population's socioeconomic conditions and reduce income inequality in Brazil, and in other low and middle-income countries, can help to reduce suicide rates.

  2. Social Determinants in Health: The Impact of Socio-Economical Issues on Individuals’ Health Conditions

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    Akbar Azizi Zeinalhajlu

    2015-08-01

    Full Text Available Background and objectives: Health, being as an important social and individual value, has many influences and consequences all through the social and individual levels. Individual’s health is one of those fundamental issues and a great target regarding countries development. Nowadays, we are witnessing changes in disease patterns from infectious to chronic in one hand and on the other hand, we can see a widening gap between health condition, life expectancy and death rate in the worldwide. Based on global statistics, chronic diseases are rapidly increasing regardless the fact that there have been remarkable achievements in health promotions. There are many kinds of differences between various countries or social levels in terms of health conditions, life expectancy and death rate. In order to determine above mentioned changes, comprehensive perspectives with biomedical orientations should be applied alongside the concentration on health social factors at the same time. The present study is aimed at investigating socio-economical issues on individuals’ health. Material and Methods: The present study is a review. UN and WHO databases, English/Persian databases containing ISI, PUBMED, MEDLINE, SID, reports by health organizations, books, thesis, magazines and journals concerning health policies in Iran have been scrutinized. Conclusion: Health is a multi-dimensional structure and can be influenced by several factors. In fact, provision, protecting and promotion of public health can go beyond the abilities of Health Ministry. In order to achieve a healthy society, it is needed to focus on social health factors and intersectional cooperation. Without any comprehensive approach to determine health and disease and replacing health based orientation with treatment based orientations, it is impossible to achieve appropriate level of health and development and will lead in wasting society resources.

  3. Household Financial Status and Gender Perspectives in Determining the Financial Impact of Foot and Mouth Disease in Lao PDR.

    Science.gov (United States)

    Nampanya, S; Khounsy, S; Abila, R; Dy, C; Windsor, P A

    2016-08-01

    The socioeconomic impacts of foot and mouth disease (FMD) during 2011-12 outbreaks on large ruminant smallholders in Laos were investigated, including examination of data on gender, household financial status and farmer husbandry practices. A mix of participatory tools and survey questionnaires at the village and household level, respectively, were conducted, involving individual farmer interviews (n = 124) and group meetings with village elders to establish criteria for classification of household financial status as being 'poor, medium or well off' according to rice sufficiency, assets and household incomes. FMD-attributable financial losses were determined by inclusion of losses due to: mortality, morbidity and costs of treatments. The estimated mean financial losses due to FMD were USD 436 (±92) in the 'poor' and USD 949 (±76) in the 'well off' household categories (P financial losses reflected differences in morbidity, farmer husbandry practices including frequency of observation of animals and thus recognition of FMD and choice of treatments. Of concern were adverse financial impacts of treatment especially where antibiotics were used; delays in reporting of FMD cases after observation of signs (mean of 2 days); admission that 10% of farmers had sold FMD-affected livestock; and that 22% of respondents claimed their large ruminants were cared for by females. The findings confirm that FMD has the most severe financial impact on poorer households and that females have a significant role in large ruminant production. It is recommended that livestock extension activities promote the benefits of prevention rather than treatment for FMD and encourage participation of women in biosecurity and disease risk management interventions including rapid reporting and regulatory compliance, particularly with animal movement controls and other biosecurity practices that reduce the negative impacts of FMD on regional food security and poverty reduction in rural

  4. The Impact of 3-Option Responses to Multiple-Choice Questions on Guessing Strategies and Cut Score Determinations

    Science.gov (United States)

    ROYAL, KENNETH D.; STOCKDALE, MYRAH R.

    2017-01-01

    Introduction: Research has asserted MCQ items using three response options (one correct answer with two distractors) is comparable to, and possibly preferable over, traditional MCQ item formats consisting of four response options (e.g., one correct answer with three distractors), or five response options (e.g., one correct answer with four distractors). Some medical educators have also adopted the practice of using 3-option responses on MCQ exams as a response to the difficulty experienced in generating additional plausible distractors. To date, however, little work has explored how 3-option responses might impact validity threats stemming from random guessing strategies, and what impact 3-option responses might have on cut-score determinations, particularly in the context of medical education classroom assessments. The purpose of this work is to further explore these critically important considerations that largely have gone ignored in the medical education literature to this point. Methods: A cumulative binomial distribution formula was used to calculate the probability that an examinee will answer at random a given number of items correctly on any exam (of any length). By way of a demonstration, a variety of scenarios were presented to illustrate how examination length and the number of response options impact examinees’ chances of passing a given examination, and how subsequent cut-score decisions may be impacted by these factors. Results: As a general rule, classroom assessments containing fewer items should utilize traditional 4-option or 5-option responses, whereas assessments of greater length are afforded greater flexibility in potentially utilizing 3-option responses. Conclusions: More research on items with 3-option responses is needed to better understand what value, if any, 3-option responses truly add to classroom assessments, and in what contexts potential benefits might be discernible. PMID:28367465

  5. Publication Metrics of Dental Journals - What is the Role of Self Citations in Determining the Impact Factor of Journals?

    Science.gov (United States)

    Elangovan, Satheesh; Allareddy, Veerasathpurush

    2015-09-01

    The objectives of the present study are to examine the publication metrics of dental journals and to delineate the role of self citations in determining the impact factor of journals. The Journal Citation Reports database was used. All dental journals that had an impact factor assigned for year 2013 were selected. The outcomes were Impact Factor (IF), Eigenfactor™ (EF), article influence score (AIS), and proportion of self-citations to total citations. Independent variables were geographic region of journal and ranking of journal (based on IF). Non-parametric tests were used to examine the associations between outcomes and independent variables. During the year 2013, 82 journals in dentistry had an IF. Mean IF was 1.489 and mean IF without including self-citations was 1.231. Mean EF scores and AIS were .00458 and .5141 respectively. Mean percentage of self cites to total citations for all dental journals was 12.24%. Higher ranking journals were associated with significantly higher EF and AIS. Journals published in USA/Canada or Europe were associated with higher IF and EF compared to those published in other regions. There were no differences in percentages of self citations to total citations either across journal rankings or geographic region. Top ranking journals tend to have higher IFs due to higher EF and AIS rather than by self-citations. Self-citations increase the impact factors of dental journals by 21%. There was no geographic influence in the percentage of self-citations to total citations thus indicating a healthy dental scientific publishing environment. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Impacts of B-factory measurements on determination of fragmentation functions from electron-positron annihilation data

    Science.gov (United States)

    Hirai, M.; Kawamura, H.; Kumano, S.; Saito, K.

    2016-11-01

    Fragmentation functions are determined for the pion and kaon by global analyses of charged-hadron production data in electron-positron annihilation. Accurate measurements were reported by the Belle and BaBar collaborations for the fragmentation functions at the center-of-mass energies of 10.52 and 10.54 GeV, respectively, at the KEK and SLAC B factories, whereas other available ee measurements were mostly done at higher energies, mainly at the Z mass of 91.2 GeV. There is a possibility that gluon fragmentation functions, as well as quark fragmentation functions, are accurately determined by scaling violation. We report our global analysis of the fragmentation functions especially to show impacts of the B-factory measurements on the fragmentation function determination. Our results indicate that the fragmentation functions are determined more accurately not only by the scaling violation but also by the high-statistical nature of the Belle and BaBar data. However, there are some tensions between the Belle and BaBar data in comparison with previous measurements. We also explain how the flavor dependence of quark fragmentation functions and the gluon function are separated by using measurements at different Q values. In particular, the electric and weak charges are different depending on the quark type, so that a light-quark flavor separation also became possible in principle due to the precise data at both √s ≃10.5 and 91.2 GeV.

  7. Impacts of B-factory measurements on determination of fragmentation functions from electron-positron annihilation data

    CERN Document Server

    Hirai, M; Kumano, S; Saito, K

    2016-01-01

    Fragmentation functions are determined for the pion and kaon by global analyses of charged-hadron production data in electron-positron annihilation. Accurate measurements were reported by the Belle and BaBar collaborations for the fragmentation functions at the center-of-mass energies of 10.52 GeV and 10.54 GeV, respectively, at the KEK and SLAC B factories, whereas other available $e^+e^-$ measurements were mostly done at higher energies, mainly at the $Z$ mass of 91.2 GeV. There is a possibility that gluon fragmentation functions, as well as quark fragmentation functions, are accurately determined by scaling violation. We report our global analysis of the fragmentation functions especially to show impacts of the B-factory measurements on the fragmentation function determination. Our results indicate that the fragmentation functions are determined more accurately not only by the scaling violation but also by high-statistical nature of the Belle and BaBar data. However, there are some tensions between the Bel...

  8. Linking expression of fructan active enzymes, cell wall invertases and sucrose transporters with fructan profiles in growing taproot of chicory (Cichorium intybus: Impact of hormonal and environmental cues

    Directory of Open Access Journals (Sweden)

    Hongbin Wei

    2016-12-01

    Full Text Available In chicory taproot, the inulin-type fructans serve as carbohydrate reserve. Inulin metabolism is mediated by fructan active enzymes (FAZYs: sucrose:sucrose 1-fructosyltransferase (1-SST; fructan synthesis, fructan:fructan-1-fructosyltransferase (1-FFT; fructan synthesis and degradation, and fructan 1-exohydrolases (1-FEH1/2a/2b; fructan degradation. In developing taproot, fructan synthesis is affected by source-to-sink sucrose transport and sink unloading. In the present study, expression of FAZYs, sucrose transporter and CWI isoforms, vacuolar invertase and sucrose synthase was determined in leaf blade, petiole and taproot of young chicory plants (taproot diameter: 2cm and compared with taproot fructan profiles for the following scenarios: i N-starvation, ii abscisic acid (ABA treatment, iii ethylene treatment (via 1-aminoyclopropane-1-carboxylic acid [ACC], and iv cold treatment. Both N-starvation and ABA treatment induced an increase in taproot oligofructans. However, while under N-starvation this increase reflected de novo synthesis, under ABA treatment gene expression profiles indicated a role for both de novo synthesis and degradation of long-chain fructans. Conversely, under ACC and cold treatment oligofructans slightly decreased, correlating with reduced expression of 1-SST and 1-FFT and increased expression of FEHs and VI. Distinct SUT and CWI expression profiles were observed, indicating a functional alignment of SUT and CWI expression with taproot fructan metabolism under different source-sink scenarios.

  9. Thinner regions of intracranial aneurysm wall correlate with regions of higher wall shear stress: a 7.0 tesla MRI

    Science.gov (United States)

    Blankena, Roos; Kleinloog, Rachel; Verweij, Bon H.; van Ooij, Pim; ten Haken, Bennie; Luijten, Peter R.; Rinkel, Gabriel J.E.; Zwanenburg, Jaco J.M.

    2016-01-01

    Purpose To develop a method for semi-quantitative wall thickness assessment on in vivo 7.0 tesla (7T) MRI images of intracranial aneurysms for studying the relation between apparent aneurysm wall thickness and wall shear stress. Materials and Methods Wall thickness was analyzed in 11 unruptured aneurysms in 9 patients, who underwent 7T MRI with a TSE based vessel wall sequence (0.8 mm isotropic resolution). A custom analysis program determined the in vivo aneurysm wall intensities, which were normalized to signal of nearby brain tissue and were used as measure for apparent wall thickness (AWT). Spatial wall thickness variation was determined as the interquartile range in AWT (the middle 50% of the AWT range). Wall shear stress was determined using phase contrast MRI (0.5 mm isotropic resolution). We performed visual and statistical comparisons (Pearson’s correlation) to study the relation between wall thickness and wall shear stress. Results 3D colored AWT maps of the aneurysms showed spatial AWT variation, which ranged from 0.07 to 0.53, with a mean variation of 0.22 (a variation of 1.0 roughly means a wall thickness variation of one voxel (0.8mm)). In all aneurysms, AWT was inversely related to WSS (mean correlation coefficient −0.35, P<0.05). Conclusions A method was developed to measure the wall thickness semi-quantitatively, using 7T MRI. An inverse correlation between wall shear stress and AWT was determined. In future studies, this non-invasive method can be used to assess spatial wall thickness variation in relation to pathophysiologic processes such as aneurysm growth and –rupture. PMID:26892986

  10. Relationship between the Pelvic Organ Prolapse Quantification system (POP-Q), the Pelvic Floor Impact Questionnaire (PFIQ-7), and the Pelvic Floor Distress Inventory (PFDI-20) before and after anterior vaginal wall prolapse surgery.

    Science.gov (United States)

    Teleman, P; Laurikainen, E; Kinne, I; Pogosean, R; Jakobsson, U; Rudnicki, M

    2015-02-01

    The aim of this study was to investigate the degree of correlation between the Pelvic Organ Quantification system (POP-Q) measurements and symptom questionnaire scores before and after surgery. This was a part of a randomized controlled study comparing conventional colporrhaphy with mesh repair surgery. The correlation between POP-Q measurements and Pelvic Floor Impact Questionnaire (PFIQ-7) and Pelvic Floor Distress Inventory (PFDI-20) scores was investigated in 164 women 55 years or older scheduled for primary anterior vaginal wall prolapse surgery at baseline and the correlation between the change in point Ba and scores following surgery. Statistical analyses used McNemar's and Wilcoxon signed-rank tests, Spearman's rank-order correlation, and multiple linear regression. Surgery significantly improved POP-Q, PFIQ-7, and PFDI-20 scores, including subscales. We observed weak correlations between POP-Q and PFIQ-7, including subscales (r 0.173-0.324, p POP-Q and urogenital symptoms based on questionnaire scores suggests that neither scoring system is optimal.

  11. Virtual-Wall Model for Molecular Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    Lijuan Qian

    2016-12-01

    Full Text Available A large number of molecules are usually required to model atomic walls in molecular dynamics simulations. A virtual-wall model is proposed in this study to describe fluid-wall molecular interactions, for reducing the computational time. The infinite repetition of unit cell structures within the atomic wall causes the periodicity of the force acting on a fluid molecule from the wall molecules. This force is first calculated and then stored in the memory. A fluid molecule appearing in the wall force field is subjected to the force from the wall molecules. The force can then be determined by the position of the molecule relative to the wall. This model avoids excessive calculations of fluid-wall interactions and reduces the computational time drastically. The time reduction is significant for small fluid density and channel height. The virtual-wall model is applied to Poiseuille and Couette flows, and to a flow in a channel with a rough surface. Results of the virtual and atomic wall simulations agree well with each other, thereby indicating the usefulness of the virtual-wall model. The appropriate bin size and cut-off radius in the virtual-wall model are also discussed.

  12. Vortex dynamics of particle-wall collisions

    Science.gov (United States)

    Leweke, Thomas; Thompson, Mark C.; Hourigan, Kerry

    2003-11-01

    We present results from an experimental and numerical study of the flow generated by a particle impacting onto a solid wall at low Reynolds numbers. Experimentally, a 3/4" bronze sphere attached to an inelastic string was lowered onto a Plexiglas plate inside a glass tank, using a stepper motor. Direct Numerical Simulations were carried out using either an axisymmetric or a fully 3D spectral-element code. The parameters varied were the running distance before impact, the sphere Reynolds number during motion, and the stopping distance away from the wall. For running lengths less than 7.5 diameters, the sphere wake remains axisymmetric in the form of an attached vortex ring. At impact, this ring overtakes the sphere and spreads out along the wall. When the sphere stops more than 0.3 diameters away from the wall, the secondary vorticity generated at the sphere surface rolls up into a second vortex ring persisting over a long time. At Reynolds number above 1000, the flow after impact exhibits a 3D instability with azimuthal wave numbers of around 20. Flow visualizations, vorticity fields, and quantitative information on the flow topology will be shown to illustrate the different regimes. The effect of a rebound of the sphere is also discussed.

  13. Habitat heterogeneity determines climate impact on zooplankton community structure and dynamics.

    Directory of Open Access Journals (Sweden)

    Saskia A Otto

    Full Text Available Understanding and predicting species distribution in space and time and consequently community structure and dynamics is an important issue in ecology, and particularly in climate change research. A crucial factor determining the composition and dynamics of animal populations is habitat heterogeneity, i.e., the number of structural elements in a given locality. In the marine pelagic environment habitat heterogeneity is represented by the distribution of physical oceanographic parameters such as temperature, salinity and oxygen that are closely linked to atmospheric conditions. Little attention has been given, however, to the role of habitat heterogeneity in modulating the response of animal communities to external climate forcing. Here we investigate the long-term dynamics of Acartia spp., Temora longicornis, and Pseudocalanus acuspes, three dominant zooplankton species inhabiting different pelagic habitats in the Central Baltic Sea (CBS. We use the three copepods as indicator species for changes in the CBS zooplankton community and apply non-linear statistical modeling techniques to compare spatial population trends and to identify their drivers. We demonstrate that effects of climate variability and change depend strongly on species-specific habitat utilization, being more direct and pronounced at the upper water layer. We propose that the differential functional response to climate-related drivers in relation to strong habitat segregation is due to alterations of the species' environmental niches. We stress the importance of understanding how anticipated climate change will affect ecological niches and habitats in order to project spatio-temporal changes in species abundance and distribution.

  14. Impact of approach used to determine removal levels of drugs of abuse during wastewater treatment.

    Science.gov (United States)

    Rodayan, Angela; Majewsky, Marius; Yargeau, Viviane

    2014-07-15

    In this study the levels of 19 drugs of abuse were estimated throughout a wastewater treatment plant using polar organic chemical integrative samplers (POCIS), 24h composite samples and grab samples. Overall removal efficiencies and removals in between each treatment unit were calculated using load data for each sampling technique as well as removals that take into account the hydraulic residence time distribution of the treatment plant (time-shifted mass balancing approach). Amphetamine-type stimulants, cocaine and its major metabolite, benzoylecgonine and opioid levels determined with 24h composite samples were generally comparable to those obtained with POCIS and grab samples. Negative mass balances resulting from the estimation of overall removal efficiencies by POCIS, day-to-day mass balancing of 24h composite and grab sample data did not occur when the hydraulic retention time (HRT) distributions of the plant were taken into account for calculation. Among the compounds investigated, cocaine exhibited the highest overall removal (90%) while codeine had the lowest with 13%, respectively. Sampling between the treatment units revealed that highest removal occurs during biological treatment as compared to primary or secondary clarification. Methylenedioxyamphetamine (MDA), fentanyl, dihydrocodeine and heroin were not detected in wastewater at any of the sampling locations at the treatment plant regardless of the sampling technique. The study demonstrates the benefits of applying the time-shifted mass balancing approach to the calculation of removals of drugs of abuse during wastewater treatment.

  15. The impact of 'social determinants of health' on epilepsy prevalence and reported medication use.

    Science.gov (United States)

    Elliott, John O; Lu, Bo; Shneker, Bassel F; Moore, J Layne; McAuley, James W

    2009-04-01

    There is a limited understanding of the complex relationship between poverty and epilepsy. To address the complex interaction of environmental and psychosocial factors in epilepsy a 'social determinants of health' model is presented where individual factors are influenced through three pathways (social environment, work and material factors). In the 2005 California Health Interview Survey, 246 of 604 (41%) persons with a history of epilepsy were in poverty, defined as Poverty Level (FPL). Multivariable logistic regression analyses revealed persons in poverty are not more likely to report a history of epilepsy compared to those not in poverty. However, persons with a history of epilepsy in poverty were significantly less likely than those not in poverty to report taking medication for epilepsy (OR 0.5) once material factors (annual income and living situation) and healthcare access were controlled for in the final sequential model. Healthcare practitioners must continue to recognize that connection to social services and the cost of medications are significant barriers to optimal care in persons with epilepsy. Improved connection to patient advocacy organizations and medication assistance programs may help close these gaps.

  16. Complex antithrombotic therapy: determinants of patient preference and impact on medication adherence

    Directory of Open Access Journals (Sweden)

    Abraham NS

    2015-11-01

    Full Text Available Neena S Abraham,1,2 Aanand D Naik,3,4 Richard L Street Jr,3–5 Diana L Castillo,3 Anita Deswal,6 Peter A Richardson,3,4 Christine M Hartman,3 George Shelton Jr,3,4 Liana Fraenkel7,8 1Division of Gastroenterology, Mayo Clinic, Scottsdale, AZ, USA; 2Divison of Healthcare Policy and Research, Department of Health Services Research, Rochester, MN, USA; 3Center for Innovations in Quality, Effectiveness, and Safety at the Michael E DeBakey VA Medical Center, Houston, TX, USA; 4Department of Medicine, Baylor College of Medicine, Houston, TX, USA; 5Department of Communication, Texas A&M University, College Station, TX, USA; 6Cardiology, Michael E DeBakey VAMC, Houston, TX, USA; 7Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA; 8Department of Medicine, Yale University, New Haven, CT, USA Purpose: For years, older patients have been prescribed multiple blood-thinning medications (complex antithrombotic therapy [CAT] to decrease their risk of cardiovascular events. These therapies, however, increase risk of adverse bleeding events. We assessed patient-reported trade-offs between cardioprotective benefit, gastrointestinal bleeding risk, and burden of self-management using adaptive conjoint analysis (ACA. As ACA could be a clinically useful tool to obtain patient preferences and guide future patient-centered care, we examined the clinical application of ACA to obtain patient preferences and the impact of ACA on medication adherence.Patients and methods: An electronic ACA survey led 201 respondents through medication risk–benefit trade-offs, revealing patients’ preferences for the CAT risk/benefit profile they valued most. The post-ACA prescription regimen was categorized as concordant or discordant with elicited preferences. Adherence was measured using VA pharmacy refill data to measure persistence of use prior to and 1 year following preference-elicitation. Additionally, we analyzed qualitative interviews of 56 respondents

  17. "I Climbed the Great Wall"

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    I finally climbed the Great Wall, A dream of my childhood; my heart is filled with pleasure at the indescribable beauty of the Wall. China’s ancient civilization is best documented by the grandeur of the Wall.

  18. Determinants and impact of microvascular obstruction in successfully reperfused ST-segment elevation myocardial infarction. Assessment by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bogaert, Jan; Kalantzi, Maria; Dymarkowski, Steven [Gasthuisberg University Hospital, Department of Radiology, Leuven (Belgium); Rademakers, Frank E.; Janssens, Stefan [Gasthuisberg University Hospital, Department of Cardiology, Leuven (Belgium)

    2007-10-15

    Microvascular obstruction (MVO) is an important and independent determinant of post-infarct remodeling. Fifty-two patients with a successfully reperfused ST-segment elevation acute myocardial infarction (MI) were studied with MRI in the first week and at 4 months post-infarction. On early (i.e., 2-5 min) post-contrast MRI, MVO was detected in 32 patients with an MVO to infarct ratio of 36.3 {+-} 24.9%. On late (i.e., 10-25 min) post-contrast MRI, MVO was detected in only 27 patients, with an MVO to infarct ratio of 15.9 {+-} 13.9%. MVO infarcts (n = 32) were associated with higher cardiac enzymes (troponin I, P = 0.016), and lower pre-revascularization thrombolysis in myocardial infarction (TIMI) flow (P = 0.018) than non-MVO infarcts (n = 20). Infarct size was larger in MVO infarcts (25.0 {+-} 14.3 g) than non-MVO infarcts (12.5 {+-} 7.9 g), P = 0.0007. Systolic wall thickening in the infarct and peri-infarct area, and left ventricular (LV) ejection fraction (EF) were worse in MVO (46.1 {+-} 7.2%) than non-MVO infarcts (50.5 {+-} 6.6%, P = 0.038). At 4 months, MVO infarcts showed more adverse remodeling and lack of functional improvement, whereas non-MVO infarcts improved significantly (LV EF at 4 months, MVO, 47.5 {+-} 7.8%, P = 0.31; non-MVO, 55.2 {+-} 10.3%, P = 0.0028). In the majority of patients with successfully reperfused ST-segment elevation MI, MVO is observed, whose present and maximal extent can be best evaluated on early post-contrast MRI. Presence of MVO is associated with more extensive infarctions, and characterized by greater adverse LV remodeling and lack of functional recovery. (orig.)

  19. Characterization of a fluidized-bed combustion ash to determine potential for environmental impact. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hassett, D.J.; Henderson, A.K.; Pflughoeft-Hassett, D.F.; Mann, M.D.; Eylands, K.E.

    1997-10-01

    A 440-megawatt, circulating fluidized-bed combustion (CFBC), lignite-fired power plant is planned for construction in Choctaw County north of Ackerman, Mississippi. This power plant will utilize Mississippi lignite from the first lignite mine in that state. Malcolm Pirnie, Inc., is working with the power plant developer in the current planning and permitting efforts for this proposed construction project. In order to accommodate Mississippi state regulatory agencies and meet appropriate permit requirements, Malcolm Pirnie needed to provide an indication of the characteristics of the by-products anticipated to be produced at the proposed plant. Since the Mississippi lignite is from a newly tapped mine and the CFBC technology is relatively new, Malcolm Pirnie contacted with the Energy and Environmental Research Center (EERC) to develop and perform a test plan for the production and characterization of ash similar to ash that will be eventually produced at the proposed power plant. The work performed at the EERC included two primary phases: production of by-products in a bench-scale CFBC unit using lignite provided by Malcolm Pirnie with test conditions delineated by Malcolm Pirnie to represent expected operating conditions for the full-scale plant; and an extensive characterization of the by-products produced, focusing on Mississippi regulatory requirements for leachability, with the understanding that return of the by-product to the mine site was an anticipated by-product management plan. The overall focus of this project was the environmental assessment of the by-product expected to be produced at the proposed power plant. Emphasis was placed on the leachability of potentially problematic trace elements in the by-products. The leaching research documented in this report was performed to determine trends of leachability of trace elements under leaching conditions appropriate for evaluating land disposal in monofills, such as returning the by-products to the mine

  20. Dioxin levels in fertilizers from Belgium: determination and evaluation of the potential impact on soil contamination.

    Science.gov (United States)

    Elskens, M; Pussemier, L; Dumortier, P; Van Langenhove, K; Scholl, G; Goeyens, L; Focant, J F

    2013-06-01

    Dioxins are harmful persistent organic pollutants (POPs) to which humans are exposed mostly via the consumption of animal products. They can enter the food chain at any stage, including crop fertilization. Fertilizers belong to several categories: synthetic chemicals providing the essential elements (mostly N, P and K) that are required by the crops but also organic fertilizers or amendments, liming materials, etc. Ninety-seven samples of fertilizers were taken in Belgium during the year 2011 and analyzed after a soft extraction procedure for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) using GC-IDHRMS. Only small qualitative differences could be observed between the main fertilizer categories since the PCDD:PCDF:DL-PCB average ratio obtained with the results expressed in TEQ was often close to 30:30:40 (typically for sewage sludge) or 40:30:30 (typically for compost). The median dioxin levels determined were