WorldWideScience

Sample records for point source controls

  1. [A landscape ecological approach for urban non-point source pollution control].

    Science.gov (United States)

    Guo, Qinghai; Ma, Keming; Zhao, Jingzhu; Yang, Liu; Yin, Chengqing

    2005-05-01

    Urban non-point source pollution is a new problem appeared with the speeding development of urbanization. The particularity of urban land use and the increase of impervious surface area make urban non-point source pollution differ from agricultural non-point source pollution, and more difficult to control. Best Management Practices (BMPs) are the effective practices commonly applied in controlling urban non-point source pollution, mainly adopting local repairing practices to control the pollutants in surface runoff. Because of the close relationship between urban land use patterns and non-point source pollution, it would be rational to combine the landscape ecological planning with local BMPs to control the urban non-point source pollution, which needs, firstly, analyzing and evaluating the influence of landscape structure on water-bodies, pollution sources and pollutant removal processes to define the relationships between landscape spatial pattern and non-point source pollution and to decide the key polluted fields, and secondly, adjusting inherent landscape structures or/and joining new landscape factors to form new landscape pattern, and combining landscape planning and management through applying BMPs into planning to improve urban landscape heterogeneity and to control urban non-point source pollution.

  2. Model Predictive Control of Z-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    2011-01-01

    This paper presents Model Predictive Control (MPC) of Z-source Neutral Point Clamped (NPC) inverter. For illustration, current control of Z-source NPC grid-connected inverter is analyzed and simulated. With MPC’s advantage of easily including system constraints, load current, impedance network...... response are obtained at the same time with a formulated Z-source NPC inverter network model. Operation steady state and transient state simulation results of MPC are going to be presented, which shows good reference tracking ability of this method. It provides new control method for Z-source NPC inverter...

  3. Rainfall Deduction Method for Estimating Non-Point Source Pollution Load for Watershed

    OpenAIRE

    Cai, Ming; Li, Huai-en; KAWAKAMI, Yoji

    2004-01-01

    The water pollution can be divided into point source pollution (PSP) and non-point source pollution (NSP). Since the point source pollution has been controlled, the non-point source pollution is becoming the main pollution source. The prediction of NSP load is being increasingly important in water pollution controlling and planning in watershed. Considering the monitoring data shortage of NPS in China, a practical estimation method of non-point source pollution load --- rainfall deduction met...

  4. Role of rural solid waste management in non-point source pollution control of Dianchi Lake catchments, China

    Institute of Scientific and Technical Information of China (English)

    Wenjing LU; Hongtao WANG

    2008-01-01

    In recent years, with control of the main municipal and industrial point pollution sources and implementation of cleaning for some inner pollution sources in the water body, the discharge of point source pollution decreased gradually, while non-point source pollution has become increasingly distressing in Dianchi Lake catchments. As one of the major targets in non-point source pollution control, an integrated solid waste controlling strategy combined with a technological solution and management system was proposed and implemented based on the waste disposal situation and characteristics of rural solid waste in the demonstration area. As the key technoogy in rural solid waste treatment, both centralized plantscale composting and a dispersed farmer-operated waste treating system showed promise in rendering timely benefits in efficiency, large handling capacity, high quality of the end product, as well as good economic return. Problems encountered during multi-substrates co-com-posting such as pathogens, high moisture content, asyn-chronism in the decomposition of different substrates, and low quality of the end product can all be tackled. 92.5% of solid waste was collected in the demonstration area, while the treating and recycling ratio reached 87.9%, which pre-vented 32.2 t nitrogen and 3.9 t phosphorus per year from entering the water body of Dianchi Lake after imple-mentation of the project.

  5. BEAMLINE-CONTROLLED STEERING OF SOURCE-POINT ANGLE AT THE ADVANCED PHOTON SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Emery, L.; Fystro, G.; Shang, H.; Smith, M.

    2017-06-25

    An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering given by the value of the "angle request" EPICS record. The new system makes the steering process much faster than before, although the older steering protocols can still be used. The robustness features of the original steering remain. Feedback messages are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinement of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way.

  6. A scanning point source for quality control of FOV uniformity in GC-PET imaging

    International Nuclear Information System (INIS)

    Bergmann, H.; Minear, G.; Dobrozemsky, G.; Nowotny, R.; Koenig, B.

    2002-01-01

    Aim: PET imaging with coincidence cameras (GC-PET) requires additional quality control procedures to check the function of coincidence circuitry and detector zoning. In particular, the uniformity response over the field of view needs special attention since it is known that coincidence counting mode may suffer from non-uniformity effects not present in single photon mode. Materials and methods: An inexpensive linear scanner with a stepper motor and a digital interface to a PC with software allowing versatile scanning modes was developed. The scanner is used with a source holder containing a Sodium-22 point source. While moving the source along the axis of rotation of the GC-PET system, a tomographic acquisition takes place. The scan covers the full axial field of view of the 2-D or 3-D scatter frame. Depending on the acquisition software, point source scanning takes place continuously while only one projection is acquired or is done in step-and-shoot mode with the number of positions equal to the number of gantry steps. Special software was developed to analyse the resulting list mode acquisition files and to produce an image of the recorded coincidence events of each head. Results: Uniformity images of coincidence events were obtained after further correction for systematic sensitivity variations caused by acquisition geometry. The resulting images are analysed visually and by calculating NEMA uniformity indices as for a planar flood field. The method has been applied successfully to two different brands of GC-PET capable gamma cameras. Conclusion: Uniformity of GC-PET can be tested quickly and accurately with a routine QC procedure, using a Sodium-22 scanning point source and an inexpensive mechanical scanning device. The method can be used for both 2-D and 3-D acquisition modes and fills an important gap in the quality control system for GC-PET

  7. Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

    Science.gov (United States)

    Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

    2016-03-29

    Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

  8. Pseudo-dynamic source modelling with 1-point and 2-point statistics of earthquake source parameters

    KAUST Repository

    Song, S. G.

    2013-12-24

    Ground motion prediction is an essential element in seismic hazard and risk analysis. Empirical ground motion prediction approaches have been widely used in the community, but efficient simulation-based ground motion prediction methods are needed to complement empirical approaches, especially in the regions with limited data constraints. Recently, dynamic rupture modelling has been successfully adopted in physics-based source and ground motion modelling, but it is still computationally demanding and many input parameters are not well constrained by observational data. Pseudo-dynamic source modelling keeps the form of kinematic modelling with its computational efficiency, but also tries to emulate the physics of source process. In this paper, we develop a statistical framework that governs the finite-fault rupture process with 1-point and 2-point statistics of source parameters in order to quantify the variability of finite source models for future scenario events. We test this method by extracting 1-point and 2-point statistics from dynamically derived source models and simulating a number of rupture scenarios, given target 1-point and 2-point statistics. We propose a new rupture model generator for stochastic source modelling with the covariance matrix constructed from target 2-point statistics, that is, auto- and cross-correlations. Our sensitivity analysis of near-source ground motions to 1-point and 2-point statistics of source parameters provides insights into relations between statistical rupture properties and ground motions. We observe that larger standard deviation and stronger correlation produce stronger peak ground motions in general. The proposed new source modelling approach will contribute to understanding the effect of earthquake source on near-source ground motion characteristics in a more quantitative and systematic way.

  9. Photoacoustic Point Source

    International Nuclear Information System (INIS)

    Calasso, Irio G.; Craig, Walter; Diebold, Gerald J.

    2001-01-01

    We investigate the photoacoustic effect generated by heat deposition at a point in space in an inviscid fluid. Delta-function and long Gaussian optical pulses are used as sources in the wave equation for the displacement potential to determine the fluid motion. The linear sound-generation mechanism gives bipolar photoacoustic waves, whereas the nonlinear mechanism produces asymmetric tripolar waves. The salient features of the photoacoustic point source are that rapid heat deposition and nonlinear thermal expansion dominate the production of ultrasound

  10. Dynamic Control of Particle Deposition in Evaporating Droplets by an External Point Source of Vapor.

    Science.gov (United States)

    Malinowski, Robert; Volpe, Giovanni; Parkin, Ivan P; Volpe, Giorgio

    2018-02-01

    The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition, and self-assembly. The shape of the final deposit depends on the flows within the droplet during evaporation. These flows are typically determined at the onset of the process by the intrinsic physical, chemical, and geometrical properties of the droplet and its environment. Here, we demonstrate deterministic emergence and real-time control of Marangoni flows within the evaporating droplet by an external point source of vapor. By varying the source location, we can modulate these flows in space and time to pattern colloids on surfaces in a controllable manner.

  11. Pseudo-dynamic source modelling with 1-point and 2-point statistics of earthquake source parameters

    KAUST Repository

    Song, S. G.; Dalguer, L. A.; Mai, Paul Martin

    2013-01-01

    statistical framework that governs the finite-fault rupture process with 1-point and 2-point statistics of source parameters in order to quantify the variability of finite source models for future scenario events. We test this method by extracting 1-point

  12. Analysis of the environmental behavior of farmers for non-point source pollution control and management in a water source protection area in China.

    Science.gov (United States)

    Wang, Yandong; Yang, Jun; Liang, Jiping; Qiang, Yanfang; Fang, Shanqi; Gao, Minxue; Fan, Xiaoyu; Yang, Gaihe; Zhang, Baowen; Feng, Yongzhong

    2018-08-15

    The environmental behavior of farmers plays an important role in exploring the causes of non-point source pollution and taking scientific control and management measures. Based on the theory of planned behavior (TPB), the present study investigated the environmental behavior of farmers in the Water Source Area of the Middle Route of the South-to-North Water Diversion Project in China. Results showed that TPB could explain farmers' environmental behavior (SMC=0.26) and intention (SMC=0.36) well. Furthermore, the farmers' attitude towards behavior (AB), subjective norm (SN), and perceived behavioral control (PBC) positively and significantly influenced their environmental intention; their environmental intention further impacted their behavior. SN was proved to be the main key factor indirectly influencing the farmers' environmental behavior, while PBC had no significant and direct effect. Moreover, environmental knowledge following as a moderator, gender and age was used as control variables to conduct the environmental knowledge on TPB construct moderated mediation analysis. It demonstrated that gender had a significant controlling effect on environmental behavior; that is, males engage in more environmentally friendly behaviors. However, age showed a significant negative controlling effect on pro-environmental intention and an opposite effect on pro-environmental behavior. In addition, environmental knowledge could negatively moderate the relationship between PBC and environmental intention. PBC had a greater impact on the environmental intention of farmers with poor environmental knowledge, compared to those with plenty environmental knowledge. Altogether, the present study could provide a theoretical basis for non-point source pollution control and management. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Prevention and Control of Agricultural Non-Point Source Pollutions in UK and Suggestions to China

    OpenAIRE

    Liu, Kun; Ren, Tianzhi; Wu, Wenliang; Meng, Fanquiao; Bellarby, Jessica; Smith, Laurence

    2016-01-01

    Currently, the world is facing challenges of maintaining food production growth while improving agricultural ecological environmental quality. The prevention and control of agricultural non-point source pollution, a key component of these challenges, is a systematic program which integrates many factors such as technology and its extension, relevant regulation and policies. In the project of UK-China Sustainable Agriculture Innovation Network, we undertook a comprehensive analysis of the prev...

  14. Modeling the contribution of point sources and non-point sources to Thachin River water pollution.

    Science.gov (United States)

    Schaffner, Monika; Bader, Hans-Peter; Scheidegger, Ruth

    2009-08-15

    Major rivers in developing and emerging countries suffer increasingly of severe degradation of water quality. The current study uses a mathematical Material Flow Analysis (MMFA) as a complementary approach to address the degradation of river water quality due to nutrient pollution in the Thachin River Basin in Central Thailand. This paper gives an overview of the origins and flow paths of the various point- and non-point pollution sources in the Thachin River Basin (in terms of nitrogen and phosphorus) and quantifies their relative importance within the system. The key parameters influencing the main nutrient flows are determined and possible mitigation measures discussed. The results show that aquaculture (as a point source) and rice farming (as a non-point source) are the key nutrient sources in the Thachin River Basin. Other point sources such as pig farms, households and industries, which were previously cited as the most relevant pollution sources in terms of organic pollution, play less significant roles in comparison. This order of importance shifts when considering the model results for the provincial level. Crosschecks with secondary data and field studies confirm the plausibility of our simulations. Specific nutrient loads for the pollution sources are derived; these can be used for a first broad quantification of nutrient pollution in comparable river basins. Based on an identification of the sensitive model parameters, possible mitigation scenarios are determined and their potential to reduce the nutrient load evaluated. A comparison of simulated nutrient loads with measured nutrient concentrations shows that nutrient retention in the river system may be significant. Sedimentation in the slow flowing surface water network as well as nitrogen emission to the air from the warm oxygen deficient waters are certainly partly responsible, but also wetlands along the river banks could play an important role as nutrient sinks.

  15. Launching and controlling Gaussian beams from point sources via planar transformation media

    Science.gov (United States)

    Odabasi, Hayrettin; Sainath, Kamalesh; Teixeira, Fernando L.

    2018-02-01

    Based on operations prescribed under the paradigm of complex transformation optics (CTO) [F. Teixeira and W. Chew, J. Electromagn. Waves Appl. 13, 665 (1999), 10.1163/156939399X01104; F. L. Teixeira and W. C. Chew, Int. J. Numer. Model. 13, 441 (2000), 10.1002/1099-1204(200009/10)13:5%3C441::AID-JNM376%3E3.0.CO;2-J; H. Odabasi, F. L. Teixeira, and W. C. Chew, J. Opt. Soc. Am. B 28, 1317 (2011), 10.1364/JOSAB.28.001317; B.-I. Popa and S. A. Cummer, Phys. Rev. A 84, 063837 (2011), 10.1103/PhysRevA.84.063837], it was recently shown in [G. Castaldi, S. Savoia, V. Galdi, A. Alù, and N. Engheta, Phys. Rev. Lett. 110, 173901 (2013), 10.1103/PhysRevLett.110.173901] that a complex source point (CSP) can be mimicked by parity-time (PT ) transformation media. Such coordinate transformation has a mirror symmetry for the imaginary part, and results in a balanced loss/gain metamaterial slab. A CSP produces a Gaussian beam and, consequently, a point source placed at the center of such a metamaterial slab produces a Gaussian beam propagating away from the slab. Here, we extend the CTO analysis to nonsymmetric complex coordinate transformations as put forth in [S. Savoia, G. Castaldi, and V. Galdi, J. Opt. 18, 044027 (2016), 10.1088/2040-8978/18/4/044027] and verify that, by using simply a (homogeneous) doubly anisotropic gain-media metamaterial slab, one can still mimic a CSP and produce Gaussian beam. In addition, we show that a Gaussian-like beams can be produced by point sources placed outside the slab as well. By making use of the extra degrees of freedom (the real and imaginary parts of the coordinate transformation) provided by CTO, the near-zero requirement on the real part of the resulting constitutive parameters can be relaxed to facilitate potential realization of Gaussian-like beams. We illustrate how beam properties such as peak amplitude and waist location can be controlled by a proper choice of (complex-valued) CTO Jacobian elements. In particular, the beam waist

  16. Source splitting via the point source method

    International Nuclear Information System (INIS)

    Potthast, Roland; Fazi, Filippo M; Nelson, Philip A

    2010-01-01

    We introduce a new algorithm for source identification and field splitting based on the point source method (Potthast 1998 A point-source method for inverse acoustic and electromagnetic obstacle scattering problems IMA J. Appl. Math. 61 119–40, Potthast R 1996 A fast new method to solve inverse scattering problems Inverse Problems 12 731–42). The task is to separate the sound fields u j , j = 1, ..., n of n element of N sound sources supported in different bounded domains G 1 , ..., G n in R 3 from measurements of the field on some microphone array—mathematically speaking from the knowledge of the sum of the fields u = u 1 + ... + u n on some open subset Λ of a plane. The main idea of the scheme is to calculate filter functions g 1 ,…, g n , n element of N, to construct u l for l = 1, ..., n from u| Λ in the form u l (x) = ∫ Λ g l,x (y)u(y)ds(y), l=1,... n. (1) We will provide the complete mathematical theory for the field splitting via the point source method. In particular, we describe uniqueness, solvability of the problem and convergence and stability of the algorithm. In the second part we describe the practical realization of the splitting for real data measurements carried out at the Institute for Sound and Vibration Research at Southampton, UK. A practical demonstration of the original recording and the splitting results for real data is available online

  17. A method to analyze "source-sink" structure of non-point source pollution based on remote sensing technology.

    Science.gov (United States)

    Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

    2013-11-01

    With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the "source-sink" theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of "source" of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km(2) in 2008, and the "sink" was 172.06 km(2). The "source" of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the "sink" was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of "source" gets weaker along with the distance from the seas boundary increase, while "sink" gets stronger. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Localization of Point Sources for Poisson Equation using State Observers

    KAUST Repository

    Majeed, Muhammad Usman

    2016-08-09

    A method based On iterative observer design is presented to solve point source localization problem for Poisson equation with riven boundary data. The procedure involves solution of multiple boundary estimation sub problems using the available Dirichlet and Neumann data from different parts of the boundary. A weighted sum of these solution profiles of sub-problems localizes point sources inside the domain. Method to compute these weights is also provided. Numerical results are presented using finite differences in a rectangular domain. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

  19. Localization of Point Sources for Poisson Equation using State Observers

    KAUST Repository

    Majeed, Muhammad Usman; Laleg-Kirati, Taous-Meriem

    2016-01-01

    A method based On iterative observer design is presented to solve point source localization problem for Poisson equation with riven boundary data. The procedure involves solution of multiple boundary estimation sub problems using the available Dirichlet and Neumann data from different parts of the boundary. A weighted sum of these solution profiles of sub-problems localizes point sources inside the domain. Method to compute these weights is also provided. Numerical results are presented using finite differences in a rectangular domain. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

  20. Point Pollution Sources Dimensioning

    Directory of Open Access Journals (Sweden)

    Georgeta CUCULEANU

    2011-06-01

    Full Text Available In this paper a method for determining the main physical characteristics of the point pollution sources is presented. It can be used to find the main physical characteristics of them. The main physical characteristics of these sources are top inside source diameter and physical height. The top inside source diameter is calculated from gas flow-rate. For reckoning the physical height of the source one takes into account the relation given by the proportionality factor, defined as ratio between the plume rise and physical height of the source. The plume rise depends on the gas exit velocity and gas temperature. That relation is necessary for diminishing the environmental pollution when the production capacity of the plant varies, in comparison with the nominal one.

  1. Research on point source simulating the γ-ray detection efficiencies of stander source

    International Nuclear Information System (INIS)

    Tian Zining; Jia Mingyan; Shen Maoquan; Yang Xiaoyan; Cheng Zhiwei

    2010-01-01

    For φ 75 mm x 25 mm sample, the full energy peak efficiencies on different heights of sample radius were obtained using the point sources, and the function parameters about the full energy peak efficiencies of point sources based on radius was fixed. The 59.54 keV γ-ray, 661.66 keV γ-ray, 1173.2 keV γ-ray, 1332.5 keV γ-ray detection efficiencies on different height of samples were obtained, based on the full energy peak efficiencies of point sources and its height, and the function parameters about the full energy peak efficiencies of surface sources based on sample height was fixed. The detection efficiency of (75 mm x 25 mm calibration source can be obtained by integrality, the detection efficiencies simulated by point sources are consistent with the results of stander source in 10%. Therefore, the calibration method of stander source can be substituted by the point source simulation method, and it tis feasible when there is no stander source.) (authors)

  2. Induced Temporal Signatures for Point-Source Detection

    International Nuclear Information System (INIS)

    Stephens, Daniel L.; Runkle, Robert C.; Carlson, Deborah K.; Peurrung, Anthony J.; Seifert, Allen; Wyatt, Cory R.

    2005-01-01

    Detection of radioactive point-sized sources is inherently divided into two regimes encompassing stationary and moving detectors. The two cases differ in their treatment of background radiation and its influence on detection sensitivity. In the stationary detector case the statistical fluctuation of the background determines the minimum detectable quantity. In the moving detector case the detector may be subjected to widely and irregularly varying background radiation, as a result of geographical and environmental variation. This significant systematic variation, in conjunction with the statistical variation of the background, requires a conservative threshold to be selected to yield the same false-positive rate as the stationary detection case. This results in lost detection sensitivity for real sources. This work focuses on a simple and practical modification of the detector geometry that increase point-source recognition via a distinctive temporal signature. A key part of this effort is the integrated development of both detector geometries that induce a highly distinctive signature for point sources and the development of statistical algorithms able to optimize detection of this signature amidst varying background. The identification of temporal signatures for point sources has been demonstrated and compared with the canonical method showing good results. This work demonstrates that temporal signatures are efficient at increasing point-source discrimination in a moving detector system

  3. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...... and better output performance comparing with traditional two-level inverters. Integrating these two types of configurations can help neutral point inverters achieve enhanced votlage buck-boost capability....

  4. Point-source inversion techniques

    Science.gov (United States)

    Langston, Charles A.; Barker, Jeffrey S.; Pavlin, Gregory B.

    1982-11-01

    A variety of approaches for obtaining source parameters from waveform data using moment-tensor or dislocation point source models have been investigated and applied to long-period body and surface waves from several earthquakes. Generalized inversion techniques have been applied to data for long-period teleseismic body waves to obtain the orientation, time function and depth of the 1978 Thessaloniki, Greece, event, of the 1971 San Fernando event, and of several events associated with the 1963 induced seismicity sequence at Kariba, Africa. The generalized inversion technique and a systematic grid testing technique have also been used to place meaningful constraints on mechanisms determined from very sparse data sets; a single station with high-quality three-component waveform data is often sufficient to discriminate faulting type (e.g., strike-slip, etc.). Sparse data sets for several recent California earthquakes, for a small regional event associated with the Koyna, India, reservoir, and for several events at the Kariba reservoir have been investigated in this way. Although linearized inversion techniques using the moment-tensor model are often robust, even for sparse data sets, there are instances where the simplifying assumption of a single point source is inadequate to model the data successfully. Numerical experiments utilizing synthetic data and actual data for the 1971 San Fernando earthquake graphically demonstrate that severe problems may be encountered if source finiteness effects are ignored. These techniques are generally applicable to on-line processing of high-quality digital data, but source complexity and inadequacy of the assumed Green's functions are major problems which are yet to be fully addressed.

  5. Reduction Assessment of Agricultural Non-Point Source Pollutant Loading

    OpenAIRE

    Fu, YiCheng; Zang, Wenbin; Zhang, Jian; Wang, Hongtao; Zhang, Chunling; Shi, Wanli

    2018-01-01

    NPS (Non-point source) pollution has become a key impact element to watershed environment at present. With the development of technology, application of models to control NPS pollution has become a very common practice for resource management and Pollutant reduction control in the watershed scale of China. The SWAT (Soil and Water Assessment Tool) model is a semi-conceptual model, which was put forward to estimate pollutant production & the influences on water quantity-quality under different...

  6. Geodetic Control Points - Multi-State Control Point Database

    Data.gov (United States)

    NSGIC State | GIS Inventory — The Multi-State Control Point Database (MCPD) is a database of geodetic and mapping control covering Idaho and Montana. The control were submitted by registered land...

  7. UHE point source survey at Cygnus experiment

    International Nuclear Information System (INIS)

    Lu, X.; Yodh, G.B.; Alexandreas, D.E.; Allen, R.C.; Berley, D.; Biller, S.D.; Burman, R.L.; Cady, R.; Chang, C.Y.; Dingus, B.L.; Dion, G.M.; Ellsworth, R.W.; Gilra, M.K.; Goodman, J.A.; Haines, T.J.; Hoffman, C.M.; Kwok, P.; Lloyd-Evans, J.; Nagle, D.E.; Potter, M.E.; Sandberg, V.D.; Stark, M.J.; Talaga, R.L.; Vishwanath, P.R.; Zhang, W.

    1991-01-01

    A new method of searching for UHE point source has been developed. With a data sample of 150 million events, we have surveyed the sky for point sources over 3314 locations (1.4 degree <δ<70.4 degree). It was found that their distribution is consistent with a random fluctuation. In addition, fifty two known potential sources, including pulsars and binary x-ray sources, were studied. The source with the largest positive excess is the Crab Nebula. An excess of 2.5 sigma above the background is observed in a bin of 2.3 degree by 2.5 degree in declination and right ascension respectively

  8. Point source reconstruction principle of linear inverse problems

    International Nuclear Information System (INIS)

    Terazono, Yasushi; Matani, Ayumu; Fujimaki, Norio; Murata, Tsutomu

    2010-01-01

    Exact point source reconstruction for underdetermined linear inverse problems with a block-wise structure was studied. In a block-wise problem, elements of a source vector are partitioned into blocks. Accordingly, a leadfield matrix, which represents the forward observation process, is also partitioned into blocks. A point source is a source having only one nonzero block. An example of such a problem is current distribution estimation in electroencephalography and magnetoencephalography, where a source vector represents a vector field and a point source represents a single current dipole. In this study, the block-wise norm, a block-wise extension of the l p -norm, was defined as the family of cost functions of the inverse method. The main result is that a set of three conditions was found to be necessary and sufficient for block-wise norm minimization to ensure exact point source reconstruction for any leadfield matrix that admit such reconstruction. The block-wise norm that satisfies the conditions is the sum of the cost of all the observations of source blocks, or in other words, the block-wisely extended leadfield-weighted l 1 -norm. Additional results are that minimization of such a norm always provides block-wisely sparse solutions and that its solutions form cones in source space

  9. X pinch a point x-ray source

    International Nuclear Information System (INIS)

    Garg, A.B.; Rout, R.K.; Shyam, A.; Srinivasan, M.

    1993-01-01

    X ray emission from an X pinch, a point x-ray source has been studied using a pin-hole camera by a 30 kV, 7.2 μ F capacitor bank. The wires of different material like W, Mo, Cu, S.S.(stainless steel) and Ti were used. Molybdenum pinch gives the most intense x-rays and stainless steel gives the minimum intensity x-rays for same bank energy (∼ 3.2 kJ). Point x-ray source of size (≤ 0.5 mm) was observed using pin hole camera. The size of the source is limited by the size of the pin hole camera. The peak current in the load is approximately 150 kA. The point x-ray source could be useful in many fields like micro lithography, medicine and to study the basic physics of high Z plasmas. (author). 4 refs., 3 figs

  10. Interferometry with flexible point source array for measuring complex freeform surface and its design algorithm

    Science.gov (United States)

    Li, Jia; Shen, Hua; Zhu, Rihong; Gao, Jinming; Sun, Yue; Wang, Jinsong; Li, Bo

    2018-06-01

    The precision of the measurements of aspheric and freeform surfaces remains the primary factor restrict their manufacture and application. One effective means of measuring such surfaces involves using reference or probe beams with angle modulation, such as tilted-wave-interferometer (TWI). It is necessary to improve the measurement efficiency by obtaining the optimum point source array for different pieces before TWI measurements. For purpose of forming a point source array based on the gradients of different surfaces under test, we established a mathematical model describing the relationship between the point source array and the test surface. However, the optimal point sources are irregularly distributed. In order to achieve a flexible point source array according to the gradient of test surface, a novel interference setup using fiber array is proposed in which every point source can be independently controlled on and off. Simulations and the actual measurement examples of two different surfaces are given in this paper to verify the mathematical model. Finally, we performed an experiment of testing an off-axis ellipsoidal surface that proved the validity of the proposed interference system.

  11. Unidentified point sources in the IRAS minisurvey

    Science.gov (United States)

    Houck, J. R.; Soifer, B. T.; Neugebauer, G.; Beichman, C. A.; Aumann, H. H.; Clegg, P. E.; Gillett, F. C.; Habing, H. J.; Hauser, M. G.; Low, F. J.

    1984-01-01

    Nine bright, point-like 60 micron sources have been selected from the sample of 8709 sources in the IRAS minisurvey. These sources have no counterparts in a variety of catalogs of nonstellar objects. Four objects have no visible counterparts, while five have faint stellar objects visible in the error ellipse. These sources do not resemble objects previously known to be bright infrared sources.

  12. Use of multiple water surface flow constructed wetlands for non-point source water pollution control.

    Science.gov (United States)

    Li, Dan; Zheng, Binghui; Liu, Yan; Chu, Zhaosheng; He, Yan; Huang, Minsheng

    2018-05-02

    Multiple free water surface flow constructed wetlands (multi-FWS CWs) are a variety of conventional water treatment plants for the interception of pollutants. This review encapsulated the characteristics and applications in the field of ecological non-point source water pollution control technology. The roles of in-series design and operation parameters (hydraulic residence time, hydraulic load rate, water depth and aspect ratio, composition of influent, and plant species) for performance intensification were also analyzed, which were crucial to achieve sustainable and effective contaminants removal, especially the retention of nutrient. The mechanism study of design and operation parameters for the removal of nitrogen and phosphorus was also highlighted. Conducive perspectives for further research on optimizing its design/operation parameters and advanced technologies of ecological restoration were illustrated to possibly interpret the functions of multi-FWS CWs.

  13. 2011 Radioactive Materials Usage Survey for Unmonitored Point Sources

    Energy Technology Data Exchange (ETDEWEB)

    Sturgeon, Richard W. [Los Alamos National Laboratory

    2012-06-27

    This report provides the results of the 2011 Radioactive Materials Usage Survey for Unmonitored Point Sources (RMUS), which was updated by the Environmental Protection (ENV) Division's Environmental Stewardship (ES) at Los Alamos National Laboratory (LANL). ES classifies LANL emission sources into one of four Tiers, based on the potential effective dose equivalent (PEDE) calculated for each point source. Detailed descriptions of these tiers are provided in Section 3. The usage survey is conducted annually; in odd-numbered years the survey addresses all monitored and unmonitored point sources and in even-numbered years it addresses all Tier III and various selected other sources. This graded approach was designed to ensure that the appropriate emphasis is placed on point sources that have higher potential emissions to the environment. For calendar year (CY) 2011, ES has divided the usage survey into two distinct reports, one covering the monitored point sources (to be completed later this year) and this report covering all unmonitored point sources. This usage survey includes the following release points: (1) all unmonitored sources identified in the 2010 usage survey, (2) any new release points identified through the new project review (NPR) process, and (3) other release points as designated by the Rad-NESHAP Team Leader. Data for all unmonitored point sources at LANL is stored in the survey files at ES. LANL uses this survey data to help demonstrate compliance with Clean Air Act radioactive air emissions regulations (40 CFR 61, Subpart H). The remainder of this introduction provides a brief description of the information contained in each section. Section 2 of this report describes the methods that were employed for gathering usage survey data and for calculating usage, emissions, and dose for these point sources. It also references the appropriate ES procedures for further information. Section 3 describes the RMUS and explains how the survey results are

  14. An international point source outbreak of typhoid fever: a European collaborative investigation*

    Science.gov (United States)

    Stanwell-Smith, R. E.; Ward, L. R.

    1986-01-01

    A point source outbreak of Salmonella typhi, degraded Vi-strain 22, affecting 32 British visitors to Kos, Greece, in 1983 was attributed by a case—control study to the consumption of a salad at one hotel. This represents the first major outbreak of typhoid fever in which a salad has been identified as the vehicle. The source of the infection was probably a carrier in the hotel staff. The investigation demonstrates the importance of national surveillance, international cooperation, and epidemiological methods in the investigation and control of major outbreaks of infection. PMID:3488842

  15. Systematic Review: Impact of point sources on antibiotic-resistant bacteria in the natural environment.

    Science.gov (United States)

    Bueno, I; Williams-Nguyen, J; Hwang, H; Sargeant, J M; Nault, A J; Singer, R S

    2018-02-01

    Point sources such as wastewater treatment plants and agricultural facilities may have a role in the dissemination of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARG). To analyse the evidence for increases in ARB in the natural environment associated with these point sources of ARB and ARG, we conducted a systematic review. We evaluated 5,247 records retrieved through database searches, including both studies that ascertained ARG and ARB outcomes. All studies were subjected to a screening process to assess relevance to the question and methodology to address our review question. A risk of bias assessment was conducted upon the final pool of studies included in the review. This article summarizes the evidence only for those studies with ARB outcomes (n = 47). Thirty-five studies were at high (n = 11) or at unclear (n = 24) risk of bias in the estimation of source effects due to lack of information and/or failure to control for confounders. Statistical analysis was used in ten studies, of which one assessed the effect of multiple sources using modelling approaches; none reported effect measures. Most studies reported higher ARB prevalence or concentration downstream/near the source. However, this evidence was primarily descriptive and it could not be concluded that there is a clear impact of point sources on increases in ARB in the environment. To quantify increases in ARB in the environment due to specific point sources, there is a need for studies that stress study design, control of biases and analytical tools to provide effect measure estimates. © 2017 Blackwell Verlag GmbH.

  16. On the point-source approximation of earthquake dynamics

    Directory of Open Access Journals (Sweden)

    Andrea Bizzarri

    2014-06-01

    Full Text Available The focus on the present study is on the point-source approximation of a seismic source. First, we compare the synthetic motions on the free surface resulting from different analytical evolutions of the seismic source (the Gabor signal (G, the Bouchon ramp (B, the Cotton and Campillo ramp (CC, the Yoffe function (Y and the Liu and Archuleta function (LA. Our numerical experiments indicate that the CC and the Y functions produce synthetics with larger oscillations and correspondingly they have a higher frequency content. Moreover, the CC and the Y functions tend to produce higher peaks in the ground velocity (roughly of a factor of two. We have also found that the falloff at high frequencies is quite different: it roughly follows ω−2 in the case of G and LA functions, it decays more faster than ω−2 for the B function, while it is slow than ω−1 for both the CC and the Y solutions. Then we perform a comparison of seismic waves resulting from 3-D extended ruptures (both supershear and subshear obeying to different governing laws against those from a single point-source having the same features. It is shown that the point-source models tend to overestimate the ground motions and that they completely miss the Mach fronts emerging from the supershear transition process. When we compare the extended fault solutions against a multiple point-sources model the agreement becomes more significant, although relevant discrepancies still persist. Our results confirm that, and more importantly quantify how, the point-source approximation is unable to adequately describe the radiation emitted during a real world earthquake, even in the most idealized case of planar fault with homogeneous properties and embedded in a homogeneous, perfectly elastic medium.

  17. Non-invasive three-dimension control of light between turbid layers using a surface quasi-point light source for precorrection.

    Science.gov (United States)

    Qiao, Mu; Liu, Honglin; Pang, Guanghui; Han, Shensheng

    2017-08-29

    Manipulating light non-invasively through inhomogeneous media is an attractive goal in many disciplines. Wavefront shaping and optical phase conjugation can focus light to a point. Transmission matrix method can control light on multiple output modes simultaneously. Here we report a non-invasive approach which enables three-dimension (3D) light control between two turbid layers. A digital optical phase conjugation mirror measured and conjugated the diffused wavefront, which originated from a quasi-point source on the front turbid layer and passed through the back turbid layer. And then, because of memory effect, the phase-conjugated wavefront could be used as a carrier wave to transport a pre-calculated wavefront through the back turbid layer. The pre-calculated wavefront could project a desired 3D light field inside the sample, which, in our experiments, consisted of two 220-grid ground glass plates spaced by a 20 mm distance. The controllable range of light, according to the memory effect, was calculated to be 80 mrad in solid angle and 16 mm on z-axis. Due to the 3D light control ability, our approach may find applications in photodynamic therapy and optogenetics. Besides, our approach can also be combined with ghost imaging or compressed sensing to achieve 3D imaging between turbid layers.

  18. Nonpoint and Point Sources of Nitrogen in Major Watersheds of the United States

    Science.gov (United States)

    Puckett, Larry J.

    1994-01-01

    Estimates of nonpoint and point sources of nitrogen were made for 107 watersheds located in the U.S. Geological Survey's National Water-Quality Assessment Program study units throughout the conterminous United States. The proportions of nitrogen originating from fertilizer, manure, atmospheric deposition, sewage, and industrial sources were found to vary with climate, hydrologic conditions, land use, population, and physiography. Fertilizer sources of nitrogen are proportionally greater in agricultural areas of the West and the Midwest than in other parts of the Nation. Animal manure contributes large proportions of nitrogen in the South and parts of the Northeast. Atmospheric deposition of nitrogen is generally greatest in areas of greatest precipitation, such as the Northeast. Point sources (sewage and industrial) generally are predominant in watersheds near cities, where they may account for large proportions of the nitrogen in streams. The transport of nitrogen in streams increases as amounts of precipitation and runoff increase and is greatest in the Northeastern United States. Because no single nonpoint nitrogen source is dominant everywhere, approaches to control nitrogen must vary throughout the Nation. Watershed-based approaches to understanding nonpoint and point sources of contamination, as used by the National Water-Quality Assessment Program, will aid water-quality and environmental managers to devise methods to reduce nitrogen pollution.

  19. [Urban non-point source pollution control by runoff retention and filtration pilot system].

    Science.gov (United States)

    Bai, Yao; Zuo, Jian-E; Gan, Li-Li; Low, Thong Soon; Miao, Heng-Feng; Ruan, Wen-Quan; Huang, Xia

    2011-09-01

    A runoff retention and filtration pilot system was designed and the long-term purification effect of the runoff was monitored. Runoff pollution characters in 2 typical events and treatment effect of the pilot system were analyzed. The results showed that the runoff was severely polluted. Event mean concentrations (EMCs) of SS, COD, TN and TP in the runoff were 361, 135, 7.88 and 0.62 mg/L respectively. The runoff formed by long rain presented an obvious first flush effect. The first 25% flow contributed more than 50% of the total pollutants loading of SS, TP, DTP and PO4(3-). The pilot system could reduce 100% of the non-point source pollution if the volume of the runoff was less than the retention tank. Otherwise the overflow will be purification by the filtration pilot system and the removal rates of SS, COD, TN, TP, DTP and PO4(3-) reached 97.4% , 61.8%, 22.6%, 85.1%, 72.1%, and 85.2% respectively. The system was stable and the removal rate of SS, COD, TN, and TP were 98.6%, 65.4%, 55.1% and 92.6%. The whole system could effectively remove the non-point source pollution caused by runoff.

  20. Very Luminous X-ray Point Sources in Starburst Galaxies

    Science.gov (United States)

    Colbert, E.; Heckman, T.; Ptak, A.; Weaver, K. A.; Strickland, D.

    Extranuclear X-ray point sources in external galaxies with luminosities above 1039.0 erg/s are quite common in elliptical, disk and dwarf galaxies, with an average of ~ 0.5 and dwarf galaxies, with an average of ~0.5 sources per galaxy. These objects may be a new class of object, perhaps accreting intermediate-mass black holes, or beamed stellar mass black hole binaries. Starburst galaxies tend to have a larger number of these intermediate-luminosity X-ray objects (IXOs), as well as a large number of lower-luminosity (1037 - 1039 erg/s) point sources. These point sources dominate the total hard X-ray emission in starburst galaxies. We present a review of both types of objects and discuss possible schemes for their formation.

  1. Study on road surface source pollution controlled by permeable pavement

    Science.gov (United States)

    Zheng, Chaocheng

    2018-06-01

    The increase of impermeable pavement in urban construction not only increases the runoff of the pavement, but also produces a large number of Non-Point Source Pollution. In the process of controlling road surface runoff by permeable pavement, a large number of particulate matter will be withheld when rainwater is being infiltrated, so as to control the source pollution at the source. In this experiment, we determined the effect of permeable road surface to remove heavy pollutants in the laboratory and discussed the related factors that affect the non-point pollution of permeable pavement, so as to provide a theoretical basis for the application of permeable pavement.

  2. Family of Quantum Sources for Improving Near Field Accuracy in Transducer Modeling by the Distributed Point Source Method

    Directory of Open Access Journals (Sweden)

    Dominique Placko

    2016-10-01

    Full Text Available The distributed point source method, or DPSM, developed in the last decade has been used for solving various engineering problems—such as elastic and electromagnetic wave propagation, electrostatic, and fluid flow problems. Based on a semi-analytical formulation, the DPSM solution is generally built by superimposing the point source solutions or Green’s functions. However, the DPSM solution can be also obtained by superimposing elemental solutions of volume sources having some source density called the equivalent source density (ESD. In earlier works mostly point sources were used. In this paper the DPSM formulation is modified to introduce a new kind of ESD, replacing the classical single point source by a family of point sources that are referred to as quantum sources. The proposed formulation with these quantum sources do not change the dimension of the global matrix to be inverted to solve the problem when compared with the classical point source-based DPSM formulation. To assess the performance of this new formulation, the ultrasonic field generated by a circular planer transducer was compared with the classical DPSM formulation and analytical solution. The results show a significant improvement in the near field computation.

  3. Design and Implementation of Photovoltaic Maximum Power Point Tracking Controller

    Directory of Open Access Journals (Sweden)

    Fawaz S. Abdullah

    2018-03-01

    Full Text Available  The power supplied by any solar array depends upon the environmental conditions as weather conditions (temperature and radiation intensity and the incident angle of the radiant source. The work aims to study the maximum power tracking schemes that used to compare the system performance without and with different types of controllers. The maximum power points of the solar panel under test studied and compared with two controller's types.  The first controller is the proportional- integral - derivative controller type and the second is the perturbation and observation algorithm controller. The associated converter system is a microcontroller based type, whereas the results studied and compared of greatest power point of the Photovoltaic panels under the different two controllers. The experimental tests results compared with simulation results to verify accurate performance.

  4. Calculation of dose for β point and sphere sources in soft tissue

    International Nuclear Information System (INIS)

    Sun Fuyin; Yuan Shuyu; Tan Jian

    1999-01-01

    Objective: To compare the results of the distribution of dose rate calculated by three typical methods for point source and sphere source of β nuclide. Methods: Calculating and comparing the distributions of dose rate from 32 P β point and sphere sources in soft tissue calculated by the three methods published in references, [1]. [2] and [3], respectively. Results: For the point source of 3.7 x 10 7 Bq (1mCi), the variations of the calculation results of the three formulas are within 10% if r≤0.35 g/cm 2 , r being the distance from source, and larger than 10% if r > 0.35 g/cm 2 . For the sphere source whose volume is 50 μl and activity is 3.7 x 10 7 Bq(1 mCi), the variations are within 10% if z≤0.15 g/cm 2 , z being the distance from the surface of the sphere source to a point outside the sphere. Conclusion: The agreement of the distributions of the dose rate calculated by the three methods mentioned above for point and sphere β source are good if the distances from point source or the surface of sphere source to the points observed are small, and poor if they are large

  5. X-ray Point Source Populations in Spiral and Elliptical Galaxies

    Science.gov (United States)

    Colbert, E.; Heckman, T.; Weaver, K.; Strickland, D.

    2002-01-01

    The hard-X-ray luminosity of non-active galaxies has been known to be fairly well correlated with the total blue luminosity since the days of the Einstein satellite. However, the origin of this hard component was not well understood. Some possibilities that were considered included X-ray binaries, extended upscattered far-infrared light via the inverse-Compton process, extended hot 107 K gas (especially in ellipitical galaxies), or even an active nucleus. Chandra images of normal, elliptical and starburst galaxies now show that a significant amount of the total hard X-ray emission comes from individual point sources. We present here spatial and spectral analyses of the point sources in a small sample of Chandra obervations of starburst galaxies, and compare with Chandra point source analyses from comparison galaxies (elliptical, Seyfert and normal galaxies). We discuss possible relationships between the number and total hard luminosity of the X-ray point sources and various measures of the galaxy star formation rate, and discuss possible options for the numerous compact sources that are observed.

  6. Trans-Z-source Neutral Point Clamped inverter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P. C.; Li, D.

    2012-01-01

    Transformer based Z-source (trans-Z-source) inverters are recently proposed by extending the traditional Z-source inverter with higher buck-boost capability as well as reducing the passive components at the same time. Multi-Level Z-source inverters are single-stage topological solutions used...... for buck-boost energy conversion with all the favourable advantages of multi-level switching retained. This paper presents three-level trans-Z-source Neutral Point Clamped (NPC) inverter topology, which achieves both the advantages of trans-Z-source and three-level NPC inverter configuration. With proper...... modulation scheme, the three-level trans-Z-source inverter can function with minimum of six device commutations per half carrier cycle (same as the traditional buck NPC inverter), while maintaining to produce the designed volt-sec average and inductive voltage boosting at ac output terminals. The designed...

  7. Determination of disintegration rates of a 60Co point source and volume sources by the sum-peak method

    International Nuclear Information System (INIS)

    Kawano, Takao; Ebihara, Hiroshi

    1990-01-01

    The disintegration rates of 60 Co as a point source (<2 mm in diameter on a thin plastic disc) and volume sources (10-100 mL solutions in a polyethylene bottle) are determined by the sum-peak method. The sum-peak formula gives the exact disintegration rate for the point source at different positions from the detector. However, increasing the volume of the solution results in enlarged deviations from the true disintegration rate. Extended sources must be treated as an amalgam of many point sources. (author)

  8. Analysis of point source size on measurement accuracy of lateral point-spread function of confocal Raman microscopy

    Science.gov (United States)

    Fu, Shihang; Zhang, Li; Hu, Yao; Ding, Xiang

    2018-01-01

    Confocal Raman Microscopy (CRM) has matured to become one of the most powerful instruments in analytical science because of its molecular sensitivity and high spatial resolution. Compared with conventional Raman Microscopy, CRM can perform three dimensions mapping of tiny samples and has the advantage of high spatial resolution thanking to the unique pinhole. With the wide application of the instrument, there is a growing requirement for the evaluation of the imaging performance of the system. Point-spread function (PSF) is an important approach to the evaluation of imaging capability of an optical instrument. Among a variety of measurement methods of PSF, the point source method has been widely used because it is easy to operate and the measurement results are approximate to the true PSF. In the point source method, the point source size has a significant impact on the final measurement accuracy. In this paper, the influence of the point source sizes on the measurement accuracy of PSF is analyzed and verified experimentally. A theoretical model of the lateral PSF for CRM is established and the effect of point source size on full-width at half maximum of lateral PSF is simulated. For long-term preservation and measurement convenience, PSF measurement phantom using polydimethylsiloxane resin, doped with different sizes of polystyrene microspheres is designed. The PSF of CRM with different sizes of microspheres are measured and the results are compared with the simulation results. The results provide a guide for measuring the PSF of the CRM.

  9. Using Soluble Reactive Phosphorus and Ammonia to Identify Point Source Discharge from Large Livestock Facilities

    Science.gov (United States)

    Borrello, M. C.; Scribner, M.; Chessin, K.

    2013-12-01

    A growing body of research draws attention to the negative environmental impacts on surface water from large livestock facilities. These impacts are mostly in the form of excessive nutrient loading resulting in significantly decreased oxygen levels. Over-application of animal waste on fields as well as direct discharge into surface water from facilities themselves has been identified as the main contributor to the development of hypoxic zones in Lake Erie, Chesapeake Bay and the Gulf of Mexico. Some regulators claim enforcement of water quality laws is problematic because of the nature and pervasiveness of non-point source impacts. Any direct discharge by a facility is a violation of permits governed by the Clean Water Act, unless the facility has special dispensation for discharge. Previous research by the principal author and others has shown runoff and underdrain transport are the main mechanisms by which nutrients enter surface water. This study utilized previous work to determine if the effects of non-point source discharge can be distinguished from direct (point-source) discharge using simple nutrient analysis and dissolved oxygen (DO) parameters. Nutrient and DO parameters were measured from three sites: 1. A stream adjacent to a field receiving manure, upstream of a large livestock facility with a history of direct discharge, 2. The same stream downstream of the facility and 3. A stream in an area relatively unimpacted by large-scale agriculture (control site). Results show that calculating a simple Pearson correlation coefficient (r) of soluble reactive phosphorus (SRP) and ammonia over time as well as temperature and DO, distinguishes non-point source from point source discharge into surface water. The r value for SRP and ammonia for the upstream site was 0.01 while the r value for the downstream site was 0.92. The control site had an r value of 0.20. Likewise, r values were calculated on temperature and DO for each site. High negative correlations

  10. Concept for Risk-based Prioritisation of Point Sources

    DEFF Research Database (Denmark)

    Overheu, N.D.; Troldborg, Mads; Tuxen, N.

    2010-01-01

    estimates on a local scale from all the sources, and 3D catchment-scale fate and transport modelling. It handles point sources at various knowledge levels and accounts for uncertainties. The tool estimates the impacts on the water supply in the catchment and provides an overall prioritisation of the sites...

  11. Strike Point Control on EAST Using an Isoflux Control Method

    International Nuclear Information System (INIS)

    Xing Zhe; Xiao Bingjia; Luo Zhengping; Walker, M. L.; Humphreys, D. A.

    2015-01-01

    For the advanced tokamak, the particle deposition and thermal load on the divertor is a big challenge. By moving the strike points on divertor target plates, the position of particle deposition and thermal load can be shifted. We could adjust the Poloidal Field (PF) coil current to achieve the strike point position feedback control. Using isoflux control method, the strike point position can be controlled by controlling the X point position. On the basis of experimental data, we establish relational expressions between X point position and strike point position. Benchmark experiments are carried out to validate the correctness and robustness of the control methods. The strike point position is successfully controlled following our command in the EAST operation. (paper)

  12. Optimization and control of a small angle ion source using an adaptive neural network controller

    Energy Technology Data Exchange (ETDEWEB)

    Brown, S.K.; Mead, W.C.; Bowling, P.S.; Jones, R.D.; Barnes, C.W.

    1993-09-01

    This project developed an automated controller based on an artificial neural network and evaluated its applicability in a real-time environment. This capability was developed within the context of a small angle negative ion source on the Discharge Test Stand at Los Alamos. The controller processes information obtained from the beam current waveform, developing a figure of merit (fom) to determine the ion source operating conditions. The fom is composed of the magnitude of the beam current, the stability of operation, and the quietness of the beam. Using no knowledge of operating conditions, the controller begins by making of rough scan of the four-dimensional operating surface. This surface uses as independent variables the anode and cathode temperatures, the hydrogen flow rate, and the arc voltage. `Me dependent variable is the fom described above. Once the rough approximation of the surface has been determined, the network formulates a model from which it determines the best operating point. The controller takes the ion source to that operating point for a reality check. As real data is fed in, the model of the operating surface is updated until the neural network`s model agrees with reality. The controller then uses a gradient ascent method to optimize the operation of the ion source. Initial tests of the controller indicate that it is remarkably capable. It has optimized the operation of the ion source on six different occasions bringing the beam to excellent quality and stability.

  13. Strategies for satellite-based monitoring of CO2 from distributed area and point sources

    Science.gov (United States)

    Schwandner, Florian M.; Miller, Charles E.; Duren, Riley M.; Natraj, Vijay; Eldering, Annmarie; Gunson, Michael R.; Crisp, David

    2014-05-01

    Atmospheric CO2 budgets are controlled by the strengths, as well as the spatial and temporal variabilities of CO2 sources and sinks. Natural CO2 sources and sinks are dominated by the vast areas of the oceans and the terrestrial biosphere. In contrast, anthropogenic and geogenic CO2 sources are dominated by distributed area and point sources, which may constitute as much as 70% of anthropogenic (e.g., Duren & Miller, 2012), and over 80% of geogenic emissions (Burton et al., 2013). Comprehensive assessments of CO2 budgets necessitate robust and highly accurate satellite remote sensing strategies that address the competing and often conflicting requirements for sampling over disparate space and time scales. Spatial variability: The spatial distribution of anthropogenic sources is dominated by patterns of production, storage, transport and use. In contrast, geogenic variability is almost entirely controlled by endogenic geological processes, except where surface gas permeability is modulated by soil moisture. Satellite remote sensing solutions will thus have to vary greatly in spatial coverage and resolution to address distributed area sources and point sources alike. Temporal variability: While biogenic sources are dominated by diurnal and seasonal patterns, anthropogenic sources fluctuate over a greater variety of time scales from diurnal, weekly and seasonal cycles, driven by both economic and climatic factors. Geogenic sources typically vary in time scales of days to months (geogenic sources sensu stricto are not fossil fuels but volcanoes, hydrothermal and metamorphic sources). Current ground-based monitoring networks for anthropogenic and geogenic sources record data on minute- to weekly temporal scales. Satellite remote sensing solutions would have to capture temporal variability through revisit frequency or point-and-stare strategies. Space-based remote sensing offers the potential of global coverage by a single sensor. However, no single combination of orbit

  14. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    modulation (PWM) strategies for controlling the Z-source NPC inverter. While developing the PWM techniques, attention has been devoted to carefully derive them from a common generic basis for improved portability, easier implementation, and most importantly, assisting readers in understanding all concepts......Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...

  15. Discretized energy minimization in a wave guide with point sources

    Science.gov (United States)

    Propst, G.

    1994-01-01

    An anti-noise problem on a finite time interval is solved by minimization of a quadratic functional on the Hilbert space of square integrable controls. To this end, the one-dimensional wave equation with point sources and pointwise reflecting boundary conditions is decomposed into a system for the two propagating components of waves. Wellposedness of this system is proved for a class of data that includes piecewise linear initial conditions and piecewise constant forcing functions. It is shown that for such data the optimal piecewise constant control is the solution of a sparse linear system. Methods for its computational treatment are presented as well as examples of their applicability. The convergence of discrete approximations to the general optimization problem is demonstrated by finite element methods.

  16. Trans-Z-source and Γ-Z-source neutral-point-clamped inverters

    DEFF Research Database (Denmark)

    Wei, Mo; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    Z-source neutral-point-clamped (NPC) inverters are earlier proposed for obtaining voltage buck-boost and three-level switching simultaneously. Their performances are, however, constrained by a trade-off between their input-to-output gain and modulation ratio. This trade-off can lead to high...

  17. The recovery of a time-dependent point source in a linear transport equation: application to surface water pollution

    International Nuclear Information System (INIS)

    Hamdi, Adel

    2009-01-01

    The aim of this paper is to localize the position of a point source and recover the history of its time-dependent intensity function that is both unknown and constitutes the right-hand side of a 1D linear transport equation. Assuming that the source intensity function vanishes before reaching the final control time, we prove that recording the state with respect to the time at two observation points framing the source region leads to the identification of the source position and the recovery of its intensity function in a unique manner. Note that at least one of the two observation points should be strategic. We establish an identification method that determines quasi-explicitly the source position and transforms the task of recovering its intensity function into solving directly a well-conditioned linear system. Some numerical experiments done on a variant of the water pollution BOD model are presented

  18. Isotropic irradiation of detectors from point sources

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    1997-01-01

    NaI(Tl) scintillator detectors have been exposed to gamma rays from 8 different point sources from different directions. Background and backscatter of gamma-rays from the surroundings have been subtracted in order to produce clean spectra. By adding spectra obtained from exposures from different ...

  19. Thermal Analysis of a Cracked Half-plane under Moving Point Heat Source

    Directory of Open Access Journals (Sweden)

    He Kuanfang

    2017-09-01

    Full Text Available The heat conduction in half-plane with an insulated crack subjected to moving point heat source is investigated. The analytical solution and the numerical means are combined to analyze the transient temperature distribution of a cracked half-plane under moving point heat source. The transient temperature distribution of the half plane structure under moving point heat source is obtained by the moving coordinate method firstly, then the heat conduction equation with thermal boundary of an insulated crack face is changed to singular integral equation by applying Fourier transforms and solved by the numerical method. The numerical examples of the temperature distribution on the cracked half-plane structure under moving point heat source are presented and discussed in detail.

  20. Application of genetic algorithm to land use optimization for non-point source pollution control based on CLUE-S and SWAT

    Science.gov (United States)

    Wang, Qingrui; Liu, Ruimin; Men, Cong; Guo, Lijia

    2018-05-01

    The genetic algorithm (GA) was combined with the Conversion of Land Use and its Effect at Small regional extent (CLUE-S) model to obtain an optimized land use pattern for controlling non-point source (NPS) pollution. The performance of the combination was evaluated. The effect of the optimized land use pattern on the NPS pollution control was estimated by the Soil and Water Assessment Tool (SWAT) model and an assistant map was drawn to support the land use plan for the future. The Xiangxi River watershed was selected as the study area. Two scenarios were used to simulate the land use change. Under the historical trend scenario (Markov chain prediction), the forest area decreased by 2035.06 ha, and was mainly converted into paddy and dryland area. In contrast, under the optimized scenario (genetic algorithm (GA) prediction), up to 3370 ha of dryland area was converted into forest area. Spatially, the conversion of paddy and dryland into forest occurred mainly in the northwest and southeast of the watershed, where the slope land occupied a large proportion. The organic and inorganic phosphorus loads decreased by 3.6% and 3.7%, respectively, in the optimized scenario compared to those in the historical trend scenario. GA showed a better performance in optimized land use prediction. A comparison of the land use patterns in 2010 under the real situation and in 2020 under the optimized situation showed that Shennongjia and Shuiyuesi should convert 1201.76 ha and 1115.33 ha of dryland into forest areas, respectively, which represented the greatest changes in all regions in the watershed. The results of this study indicated that GA and the CLUE-S model can be used to optimize the land use patterns in the future and that SWAT can be used to evaluate the effect of land use optimization on non-point source pollution control. These methods may provide support for land use plan of an area.

  1. Search for high energy cosmic neutrino point sources with ANTARES

    International Nuclear Information System (INIS)

    Halladjian, G.

    2010-01-01

    The aim of this thesis is the search for high energy cosmic neutrinos emitted by point sources with the ANTARES neutrino telescope. The detection of high energy cosmic neutrinos can bring answers to important questions such as the origin of cosmic rays and the γ-rays emission processes. In the first part of the thesis, the neutrino flux emitted by galactic and extragalactic sources and the number of events which can be detected by ANTARES are estimated. This study uses the measured γ-ray spectra of known sources taking into account the γ-ray absorption by the extragalactic background light. In the second part of the thesis, the absolute pointing of the ANTARES telescope is evaluated. Being located at a depth of 2475 m in sea water, the orientation of the detector is determined by an acoustic positioning system which relies on low and high frequency acoustic waves measurements between the sea surface and the bottom. The third part of the thesis is a search for neutrino point sources in the ANTARES data. The search algorithm is based on a likelihood ratio maximization method. It is used in two search strategies; 'the candidate sources list strategy' and 'the all sky search strategy'. Analysing 2007+2008 data, no discovery is made and the world's best upper limits on neutrino fluxes from various sources in the Southern sky are established. (author)

  2. Nomogram for Determining Shield Thickness for Point and Line Sources of Gamma Rays

    Energy Technology Data Exchange (ETDEWEB)

    Joenemalm, C; Malen, K

    1966-10-15

    A set of nomograms is given for the determination of the required shield thickness against gamma radiation. The sources handled are point and infinite line sources with shields of Pb, Fe, magnetite concrete (p = 3.6), ordinary concrete (p = 2.3) or water. The gamma energy range covered is 0.5 - 10 MeV. The nomograms are directly applicable for source and dose points on the surfaces of the shield. They can easily be extended to source and dose points in other positions by applying a geometrical correction. Also included are data for calculation of the source strength for the most common materials and for fission product sources.

  3. Nomogram for Determining Shield Thickness for Point and Line Sources of Gamma Rays

    International Nuclear Information System (INIS)

    Joenemalm, C.; Malen, K

    1966-10-01

    A set of nomograms is given for the determination of the required shield thickness against gamma radiation. The sources handled are point and infinite line sources with shields of Pb, Fe, magnetite concrete (p = 3.6), ordinary concrete (p = 2.3) or water. The gamma energy range covered is 0.5 - 10 MeV. The nomograms are directly applicable for source and dose points on the surfaces of the shield. They can easily be extended to source and dose points in other positions by applying a geometrical correction. Also included are data for calculation of the source strength for the most common materials and for fission product sources

  4. Point source search techniques in ultra high energy gamma ray astronomy

    International Nuclear Information System (INIS)

    Alexandreas, D.E.; Biller, S.; Dion, G.M.; Lu, X.Q.; Yodh, G.B.; Berley, D.; Goodman, J.A.; Haines, T.J.; Hoffman, C.M.; Horch, E.; Sinnis, C.; Zhang, W.

    1993-01-01

    Searches for point astrophysical sources of ultra high energy (UHE) gamma rays are plagued by large numbers of background events from isotropic cosmic rays. Some of the methods that have been used to estimate the expected number of background events coming from the direction of a possible source are found to contain biases. Search techniques that avoid this problem are described. There is also a discussion of how to optimize the sensitivity of a search to emission from a point source. (orig.)

  5. Non-point Source Pollutants Loss of Planting Industry in the Yunnan Plateau Lake Basin, China

    Directory of Open Access Journals (Sweden)

    ZHAO Zu-jun

    2017-12-01

    Full Text Available Non-point source pollution of planting has become a major factor affecting the quality and safety of water environment in our country. In recent years, some studies show that the loss of nitrogen and phosphorus in agricultural chemical fertilizers has led to more serious non-point source pollution. By means of the loss coefficient method and spatial overlay analysis, the loss amount, loss of strength and its spatial distribution characteristics of total nitrogen, total phosphorus, ammonium nitrogen and nitrate nitrogen were analyzed in the Fuxian Lake, Xingyun Lake and Qilu Lake Basin in 2015. The results showed that:The loss of total nitrogen was the highest in the three basins, following by ammonium nitrogen, nitrate nitrogen and total phosphorus, which the loss of intensity range were 2.73~22.07, 0.003~3.52, 0.01~2.25 kg·hm-2 and 0.05~1.36 kg·hm-2, respectively. Total nitrogen and total phosphorus loss were mainly concentrated in the southwest of Qilu Lake, west and south of Xingyun Lake. Ammonium nitrogen and nitrate nitrogen loss mainly concentrated in the south of Qilu Lake, south and north of Xingyun Lake. The loss of nitrogen and phosphorus was mainly derived from cash crops and rice. Therefore, zoning, grading and phased prevention and control schemes were proposed, in order to provide scientific basis for controlling non-point source pollution in the study area.

  6. Open-Source Automated Mapping Four-Point Probe

    Directory of Open Access Journals (Sweden)

    Handy Chandra

    2017-01-01

    Full Text Available Scientists have begun using self-replicating rapid prototyper (RepRap 3-D printers to manufacture open source digital designs of scientific equipment. This approach is refined here to develop a novel instrument capable of performing automated large-area four-point probe measurements. The designs for conversion of a RepRap 3-D printer to a 2-D open source four-point probe (OS4PP measurement device are detailed for the mechanical and electrical systems. Free and open source software and firmware are developed to operate the tool. The OS4PP was validated against a wide range of discrete resistors and indium tin oxide (ITO samples of different thicknesses both pre- and post-annealing. The OS4PP was then compared to two commercial proprietary systems. Results of resistors from 10 to 1 MΩ show errors of less than 1% for the OS4PP. The 3-D mapping of sheet resistance of ITO samples successfully demonstrated the automated capability to measure non-uniformities in large-area samples. The results indicate that all measured values are within the same order of magnitude when compared to two proprietary measurement systems. In conclusion, the OS4PP system, which costs less than 70% of manual proprietary systems, is comparable electrically while offering automated 100 micron positional accuracy for measuring sheet resistance over larger areas.

  7. Open-Source Automated Mapping Four-Point Probe.

    Science.gov (United States)

    Chandra, Handy; Allen, Spencer W; Oberloier, Shane W; Bihari, Nupur; Gwamuri, Jephias; Pearce, Joshua M

    2017-01-26

    Scientists have begun using self-replicating rapid prototyper (RepRap) 3-D printers to manufacture open source digital designs of scientific equipment. This approach is refined here to develop a novel instrument capable of performing automated large-area four-point probe measurements. The designs for conversion of a RepRap 3-D printer to a 2-D open source four-point probe (OS4PP) measurement device are detailed for the mechanical and electrical systems. Free and open source software and firmware are developed to operate the tool. The OS4PP was validated against a wide range of discrete resistors and indium tin oxide (ITO) samples of different thicknesses both pre- and post-annealing. The OS4PP was then compared to two commercial proprietary systems. Results of resistors from 10 to 1 MΩ show errors of less than 1% for the OS4PP. The 3-D mapping of sheet resistance of ITO samples successfully demonstrated the automated capability to measure non-uniformities in large-area samples. The results indicate that all measured values are within the same order of magnitude when compared to two proprietary measurement systems. In conclusion, the OS4PP system, which costs less than 70% of manual proprietary systems, is comparable electrically while offering automated 100 micron positional accuracy for measuring sheet resistance over larger areas.

  8. Scattering and absorption of particles emitted by a point source in a cluster of point scatterers

    International Nuclear Information System (INIS)

    Liljequist, D.

    2012-01-01

    A theory for the scattering and absorption of particles isotropically emitted by a point source in a cluster of point scatterers is described and related to the theory for the scattering of an incident particle beam. The quantum mechanical probability of escape from the cluster in different directions is calculated, as well as the spatial distribution of absorption events within the cluster. A source strength renormalization procedure is required. The average quantum scattering in clusters with randomly shifting scatterer positions is compared to trajectory simulation with the aim of studying the validity of the trajectory method. Differences between the results of the quantum and trajectory methods are found primarily for wavelengths larger than the average distance between nearest neighbour scatterers. The average quantum results include, for example, a local minimum in the number of absorption events at the location of the point source and interference patterns in the angle-dependent escape probability as well as in the distribution of absorption events. The relative error of the trajectory method is in general, though not generally, of similar magnitude as that obtained for beam scattering.

  9. OH masers associated with IRAS point sources

    NARCIS (Netherlands)

    Masheder, MRW; Cohen, RJ; Martin-Hernandez, NL; Migenes,; Reid, MJ

    2002-01-01

    We report a search for masers from the Lambda-doublet of the ground-state of OH at 18cm, carried out with the Jodrell Bank Lovell Telescope and with the 25m Dwingeloo telescope. All objects north of delta = -20degrees which appear in the IRAS Point Source Catalog with fluxes > 1000 Jy at 60mum and

  10. Resolution of point sources of light as analyzed by quantum detection theory.

    Science.gov (United States)

    Helstrom, C. W.

    1973-01-01

    The resolvability of point sources of incoherent thermal light is analyzed by quantum detection theory in terms of two hypothesis-testing problems. In the first, the observer must decide whether there are two sources of equal radiant power at given locations, or whether there is only one source of twice the power located midway between them. In the second problem, either one, but not both, of two point sources is radiating, and the observer must decide which it is. The decisions are based on optimum processing of the electromagnetic field at the aperture of an optical instrument. In both problems the density operators of the field under the two hypotheses do not commute. The error probabilities, determined as functions of the separation of the points and the mean number of received photons, characterize the ultimate resolvability of the sources.

  11. Mapping correlation of a simulated dark matter source and a point source in the gamma-ray sky - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Alexander [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-23

    In my research, I analyzed how two gamma-ray source models interact with one another when optimizing to fit data. This is important because it becomes hard to distinguish between the two point sources when they are close together or looking at low energy photons. The reason for the first is obvious, the reason why they become harder to distinguish at lower photon energies is the resolving power of the Fermi Gamma-Ray Space Telescope gets worse at lower energies. When the two point sources are highly correlated (hard to distinguish between), we need to change our method of statistical analysis. What I did was show that highly correlated sources have larger uncertainties associated with them, caused by an optimizer not knowing which point source’s parameters to optimize. I also mapped out where their is high correlation for 2 different theoretical mass dark matter point sources so that people analyzing them in the future knew where they had to use more sophisticated statistical analysis.

  12. Point sources and multipoles in inverse scattering theory

    CERN Document Server

    Potthast, Roland

    2001-01-01

    Over the last twenty years, the growing availability of computing power has had an enormous impact on the classical fields of direct and inverse scattering. The study of inverse scattering, in particular, has developed rapidly with the ability to perform computational simulations of scattering processes and led to remarkable advances in a range of applications, from medical imaging and radar to remote sensing and seismic exploration. Point Sources and Multipoles in Inverse Scattering Theory provides a survey of recent developments in inverse acoustic and electromagnetic scattering theory. Focusing on methods developed over the last six years by Colton, Kirsch, and the author, this treatment uses point sources combined with several far-reaching techniques to obtain qualitative reconstruction methods. The author addresses questions of uniqueness, stability, and reconstructions for both two-and three-dimensional problems.With interest in extracting information about an object through scattered waves at an all-ti...

  13. The peak efficiency calibration of volume source using 152Eu point source in computer

    International Nuclear Information System (INIS)

    Shen Tingyun; Qian Jianfu; Nan Qinliang; Zhou Yanguo

    1997-01-01

    The author describes the method of the peak efficiency calibration of volume source by means of 152 Eu point source for HPGe γ spectrometer. The peak efficiency can be computed by Monte Carlo simulation, after inputting parameter of detector. The computation results are in agreement with the experimental results with an error of +-3.8%, with an exception one is about +-7.4%

  14. Controllable resonant tunnelling through single-point potentials: A point triode

    International Nuclear Information System (INIS)

    Zolotaryuk, A.V.; Zolotaryuk, Yaroslav

    2015-01-01

    A zero-thickness limit of three-layer heterostructures under two bias voltages applied externally, where one of which is supposed to be a gate parameter, is studied. As a result, an effect of controllable resonant tunnelling of electrons through single-point potentials is shown to exist. Therefore the limiting structure may be termed a “point triode” and considered in the theory of point interactions as a new object. The simple limiting analytical expressions adequately describe the resonant behaviour in the transistor with realistic parameter values and thus one can conclude that the zero-range limit of multi-layer structures may be used in fabricating nanodevices. The difference between the resonant tunnelling across single-point potentials and the Fabry–Pérot interference effect is also emphasized. - Highlights: • The zero-thickness limit of three-layer heterostructures is described in terms of point interactions. • The effect of resonant tunnelling through these single-point potentials is established. • The resonant tunnelling is shown to be controlled by a gate voltage

  15. Optical identifications of IRAS point sources: the Fornax, Hydra I and Coma clusters

    International Nuclear Information System (INIS)

    Wang, G.; Leggett, S.K.; Savage, A.

    1991-01-01

    We present optical identifications for 66 IRAS point sources in the region of the Fornax cluster of galaxies, 106 IRAS point sources in the region of the Hydra I cluster of galaxies (Abell 1060) and 59 IRAS point sources in the region of the Coma cluster of galaxies (Abell 1656). Eight other sources in Hydra I do not have optical counterparts and are very probably due to infrared cirrus. Twenty-three (35 per cent) of the Fornax sources are associated with stars and 43 (65 per cent) with galaxies; 48 (42 per cent) of the Hydra I sources are associated with stars and 58 (51 per cent) with galaxies; 18 (31 per cent) of the Coma sources are associated with stars and 41 (69 per cent) with galaxies. The stellar and infrared cirrus surface density is consistent with the galactic latitude of each field. (author)

  16. LOWERING ICECUBE'S ENERGY THRESHOLD FOR POINT SOURCE SEARCHES IN THE SOUTHERN SKY

    Energy Technology Data Exchange (ETDEWEB)

    Aartsen, M. G. [Department of Physics, University of Adelaide, Adelaide, 5005 (Australia); Abraham, K. [Physik-department, Technische Universität München, D-85748 Garching (Germany); Ackermann, M. [DESY, D-15735 Zeuthen (Germany); Adams, J. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Aguilar, J. A.; Ansseau, I. [Université Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels (Belgium); Ahlers, M. [Department of Physics and Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin, Madison, WI 53706 (United States); Ahrens, M. [Oskar Klein Centre and Department of Physics, Stockholm University, SE-10691 Stockholm (Sweden); Altmann, D.; Anton, G. [Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Andeen, K. [Department of Physics, Marquette University, Milwaukee, WI, 53201 (United States); Anderson, T.; Arlen, T. C. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Archinger, M.; Baum, V. [Institute of Physics, University of Mainz, Staudinger Weg 7, D-55099 Mainz (Germany); Arguelles, C. [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Auffenberg, J. [III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen (Germany); Bai, X. [Physics Department, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Barwick, S. W. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Bay, R., E-mail: jacob.feintzeig@gmail.com, E-mail: naoko@icecube.wisc.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States); Collaboration: IceCube Collaboration; and others

    2016-06-20

    Observation of a point source of astrophysical neutrinos would be a “smoking gun” signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current ν{sub μ} interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (∼100 TeV) starting event in the sample found that this event alone represents a 2.8 σ deviation from the hypothesis that the data consists only of atmospheric background.

  17. A method to analyze “source–sink” structure of non-point source pollution based on remote sensing technology

    International Nuclear Information System (INIS)

    Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

    2013-01-01

    With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the “source–sink” theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of “source” of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km 2 in 2008, and the “sink” was 172.06 km 2 . The “source” of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the “sink” was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of “source” gets weaker along with the distance from the seas boundary increase, while “sink” gets stronger. -- Highlights: •We built an index to study the “source–sink” structure of NSP in a space scale. •The Index was applied in Jiulongjiang estuary and got a well result. •The study is beneficial to discern the high load area of non-point source pollution. -- “Source–Sink” Structure of non-point source nitrogen and phosphorus pollution in Jiulongjiang estuary in China was worked out by the Grid Landscape Contrast Index

  18. A systematic analysis of the Braitenberg vehicle 2b for point-like stimulus sources

    International Nuclear Information System (INIS)

    Rañó, Iñaki

    2012-01-01

    Braitenberg vehicles have been used experimentally for decades in robotics with limited empirical understanding. This paper presents the first mathematical model of the vehicle 2b, displaying so-called aggression behaviour, and analyses the possible trajectories for point-like smooth stimulus sources. This sensory-motor steering control mechanism is used to implement biologically grounded target approach, target-seeking or obstacle-avoidance behaviour. However, the analysis of the resulting model reveals that complex and unexpected trajectories can result even for point-like stimuli. We also prove how the implementation of the controller and the vehicle morphology interact to affect the behaviour of the vehicle. This work provides a better understanding of Braitenberg vehicle 2b, explains experimental results and paves the way for a formally grounded application on robotics as well as for a new way of understanding target seeking in biology. (paper)

  19. Tackling non-point source water pollution in British Columbia: An action plan

    Energy Technology Data Exchange (ETDEWEB)

    1998-01-01

    Efforts to protect British Columbia water quality by regulating point discharges from municipal and industrial sources have generally been successful, and it is recognized that the major remaining cause of water pollution in the province is from non-point sources. These sources are largely unregulated and associated with urbanization, agriculture, and other forms of land development. The first part of this report reviews the provincial commitment to clean water, the effects of non-point-source (NPS) pollution, and the management of NPS in the province. Part 2 describes the main causes of NPS in British Columbia: Land development, agriculture, stormwater runoff, on-site sewage systems, forestry and range activities, atmospheric deposition, and boating/marine activities. Finally, it presents key components of the province's NPS action plan: Education and training, prevention at site, land use planning and co-ordination, assessment and reporting, economic incentives, legislation and regulation, and implementation.

  20. Epidemiology, public health, and health surveillance around point sources of pollution

    International Nuclear Information System (INIS)

    Stebbings, J.H. Jr.

    1981-01-01

    In industrial society a large number of point sources of pollution exist, such as chemical plants, smelters, and nuclear power plants. Public concern has forced the practising epidemiologist to undertake health surveillance of the usually small populations living around point sources. Although not justifiable as research, such epidemiologic surveillance activities are becoming a routine part of public health practice, and this trend will continue. This introduction reviews concepts of epidemiologic surveillance, and institutional problems relating to the quality of such applied research

  1. The resolution of point sources of light as analyzed by quantum detection theory

    Science.gov (United States)

    Helstrom, C. W.

    1972-01-01

    The resolvability of point sources of incoherent light is analyzed by quantum detection theory in terms of two hypothesis-testing problems. In the first, the observer must decide whether there are two sources of equal radiant power at given locations, or whether there is only one source of twice the power located midway between them. In the second problem, either one, but not both, of two point sources is radiating, and the observer must decide which it is. The decisions are based on optimum processing of the electromagnetic field at the aperture of an optical instrument. In both problems the density operators of the field under the two hypotheses do not commute. The error probabilities, determined as functions of the separation of the points and the mean number of received photons, characterize the ultimate resolvability of the sources.

  2. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    Science.gov (United States)

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

  3. Identification of a time-varying point source in a system of two coupled linear diffusion-advection- reaction equations: application to surface water pollution

    International Nuclear Information System (INIS)

    Hamdi, Adel

    2009-01-01

    This paper deals with the identification of a point source (localization of its position and recovering the history of its time-varying intensity function) that constitutes the right-hand side of the first equation in a system of two coupled 1D linear transport equations. Assuming that the source intensity function vanishes before reaching the final control time, we prove the identifiability of the sought point source from recording the state relative to the second coupled transport equation at two observation points framing the source region. Note that at least one of the two observation points should be strategic. We establish an identification method that uses these records to identify the source position as the root of a continuous and strictly monotonic function. Whereas the source intensity function is recovered using a recursive formula without any need of an iterative process. Some numerical experiments on a variant of the surface water pollution BOD–OD coupled model are presented

  4. Pulsewidth-modulated 2-source neutral-point-clamped inverter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, Poh Chang; Gao, Feng

    2007-01-01

    This paper presents the careful integration of a newly proposed Z-source topological concept to the basic neutral-point-clamped (NPC) inverter topology for designing a three-level inverter with both voltage-buck and voltage-boost capabilities. The designed Z-source NPC inverter uses two unique X......-shaped inductance-capacitance (LC) impedance networks that are connected between two isolated dc input power sources and its inverter circuitry for boosting its AC output voltage. Through the design of an appropriate pulsewidth-modulation (PWM) algorithm, the two impedance networks can be short......-circuited sequentially (without shooting through the inverter full DC link) for implementing the ldquonearest-three-vectorrdquo modulation principle with minimized harmonic distortion and device commutations per half carrier cycle while performing voltage boosting. With only a slight modification to the inverter PWM...

  5. Clinical Validation of Point-Source Corneal Topography in Keratoplasty

    NARCIS (Netherlands)

    Vrijling, A C L; Braaf, B.; Snellenburg, J.J.; de Lange, F.; Zaal, M.J.W.; van der Heijde, G.L.; Sicam, V.A.D.P.

    2011-01-01

    Purpose. To validate the clinical performance of point-source corneal topography (PCT) in postpenetrating keratoplasty (PKP) eyes and to compare it with conventional Placido-based topography. Methods. Corneal elevation maps of the anterior corneal surface were obtained from 20 post-PKP corneas using

  6. Inadequate control of world's radioactive sources

    International Nuclear Information System (INIS)

    2002-01-01

    The radioactive materials needed to build a 'dirty bomb' can be found in almost any country in the world, and more than 100 countries may have inadequate control and monitoring programs necessary to prevent or even detect the theft of these materials. The IAEA points out that while radioactive sources number in the millions, only a small percentage have enough strength to cause serious radiological harm. It is these powerful sources that need to be focused on as a priority. In a significant recent development, the IAEA, working in collaboration with the United States Department of Energy (DOE) and the Russian Federation's Ministry for Atomic Energy (MINATOM), have established a tripartite working group on 'Securing and Managing Radioactive Sources'. Through its program to help countries improve their national infrastructures for radiation safety and security, the IAEA has found that more than 100 countries may have no minimum infrastructure in place to properly control radiation sources. However, many IAEA Member States - in Africa, Asia, Latin America, and Europe - are making progress through an IAEA project to strengthen their capabilities to control and regulate radioactive sources. The IAEA is also concerned about the over 50 countries that are not IAEA Member States (there are 134), as they do not benefit from IAEA assistance and are likely to have no regulatory infrastructure. The IAEA has been active in lending its expertise to search out and secure orphaned sources in several countries. More than 70 States have joined with the IAEA to collect and share information on trafficking incidents and other unauthorized movements of radioactive sources and other radioactive materials. The IAEA and its Member States are working hard to raise levels of radiation safety and security, especially focusing on countries known to have urgent needs. The IAEA has taken the leading role in the United Nations system in establishing standards of safety, the most significant of

  7. Evaluating horizontal positional accuracy of low-cost UAV orthomosaics over forest terrain using ground control points extracted from different sources

    Science.gov (United States)

    Patias, Petros; Giagkas, Fotis; Georgiadis, Charalampos; Mallinis, Giorgos; Kaimaris, Dimitris; Tsioukas, Vassileios

    2017-09-01

    Within the field of forestry, forest road mapping and inventory plays an important role in management activities related to wood harvesting industry, sentiment and water run-off modelling, biodiversity distribution and ecological connectivity, recreation activities, future planning of forest road networks and wildfire protection and fire-fighting. Especially in countries of the Mediterranean Rim, knowledge at regional and national scales regarding the distribution and the characteristics of rural and forest road network is essential in order to ensure an effective emergency management and rapid response of the fire-fighting mechanism. Yet, the absence of accurate and updated geodatabases and the drawbacks related to the use of traditional cartographic methods arising from the forest environment settings, and the cost and efforts needed, as thousands of meters need to be surveyed per site, trigger the need for new data sources and innovative mapping approaches. Monitoring the condition of unpaved forest roads with unmanned aerial vehicle technology is an attractive option for substituting objective, laboursome surveys. Although photogrammetric processing of UAV imagery can achieve accuracy of 1-2 centimeters and dense point clouds, the process is commonly based on the establishment of control points. In the case of forest road networks, which are linear features, there is a need for a great number of control points. Our aim is to evaluate low-cost UAV orthoimages generated over forest areas with GCP's captured from existing national scale aerial orthoimagery, satellite imagery available through a web mapping service (WMS), field surveys using Mobile Mapping System and GNSS receiver. We also explored the direct georeferencing potential through the GNSS onboard the low cost UAV. The results suggest that the GNSS approach proved to most accurate, while the positional accuracy derived using the WMS and the aerial orthoimagery datasets deemed satisfactory for the

  8. Characteristics of a multi-keV monochromatic point x-ray source

    Indian Academy of Sciences (India)

    Temporal, spatial and spectral characteristics of a multi-keV monochromatic point x-ray source based on vacuum diode with laser-produced plasma as cathode are presented. Electrons from a laser-produced aluminium plasma were accelerated towards a conical point tip titanium anode to generate K-shell x-ray radiation.

  9. Extending the search for neutrino point sources with IceCube above the horizon

    Energy Technology Data Exchange (ETDEWEB)

    IceCube Collaboration; Abbasi, R.

    2009-11-20

    Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This approach improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

  10. Calculation and analysis of the non-point source pollution in the upstream watershed of the Panjiakou Reservoir, People's Republic of China

    Science.gov (United States)

    Zhang, S.; Tang, L.

    2007-05-01

    distributed model, it is possible to view model output as it varies across the basin, so the critical areas and reaches can be found in the study area. According to the simulation results, it is found that different land uses can yield different results and fertilization in rainy season has an important impact on the non- point source pollution. The limitations of the SWAT model are also discussed and the measures of the control and prevention of non- point source pollution for Panjiakou Reservoir are presented according to the analysis of model calculation results.

  11. Point source identification in nonlinear advection–diffusion–reaction systems

    International Nuclear Information System (INIS)

    Mamonov, A V; Tsai, Y-H R

    2013-01-01

    We consider a problem of identification of point sources in time-dependent advection–diffusion systems with a nonlinear reaction term. The linear counterpart of the problem in question can be reduced to solving a system of nonlinear algebraic equations via the use of adjoint equations. We extend this approach by constructing an algorithm that solves the problem iteratively to account for the nonlinearity of the reaction term. We study the question of improving the quality of source identification by adding more measurements adaptively using the solution obtained previously with a smaller number of measurements. (paper)

  12. Detection of Point Sources on Two-Dimensional Images Based on Peaks

    Directory of Open Access Journals (Sweden)

    R. B. Barreiro

    2005-09-01

    Full Text Available This paper considers the detection of point sources in two-dimensional astronomical images. The detection scheme we propose is based on peak statistics. We discuss the example of the detection of far galaxies in cosmic microwave background experiments throughout the paper, although the method we present is totally general and can be used in many other fields of data analysis. We consider sources with a Gaussian profile—that is, a fair approximation of the profile of a point source convolved with the detector beam in microwave experiments—on a background modeled by a homogeneous and isotropic Gaussian random field characterized by a scale-free power spectrum. Point sources are enhanced with respect to the background by means of linear filters. After filtering, we identify local maxima and apply our detection scheme, a Neyman-Pearson detector that defines our region of acceptance based on the a priori pdf of the sources and the ratio of number densities. We study the different performances of some linear filters that have been used in this context in the literature: the Mexican hat wavelet, the matched filter, and the scale-adaptive filter. We consider as well an extension to two dimensions of the biparametric scale-adaptive filter (BSAF. The BSAF depends on two parameters which are determined by maximizing the number density of real detections while fixing the number density of spurious detections. For our detection criterion the BSAF outperforms the other filters in the interesting case of white noise.

  13. Assessment of the impact of point source pollution from the ...

    African Journals Online (AJOL)

    Assessment of the impact of point source pollution from the Keiskammahoek Sewage ... Water SA. Journal Home · ABOUT THIS JOURNAL · Advanced Search ... Also, significant pollution of the receiving Keiskamma River was indicated for ...

  14. Tackling non-point source water pollution in British Columbia : an action plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    British Columbia`s approach to water quality management is discussed. The BC efforts include regulating `end of pipe` point discharges from industrial and municipal outfalls. The major remaining cause of water pollution is from non-point sources (NPS). NPS water pollution is caused by the release of pollutants from different and diffuse sources, mostly unregulated and associated with urbanization, agriculture and other forms of land development. The importance of dealing with such problems on an immediate basis to avoid a decline in water quality in the province is emphasized. Major sources of water pollution in British Columbia include: land development, agriculture, storm water runoff, onsite sewage systems, forestry, atmospheric deposition, and marine activities. 3 tabs.

  15. Guaranteed Unresolved Point Source Emission and the Gamma-ray Background

    International Nuclear Information System (INIS)

    Pavlidou, Vasiliki; Siegal-Gaskins, Jennifer M.; Brown, Carolyn; Fields, Brian D.; Olinto, Angela V.

    2007-01-01

    The large majority of EGRET point sources remain without an identified low-energy counterpart, and a large fraction of these sources are most likely extragalactic. Whatever the nature of the extragalactic EGRET unidentified sources, faint unresolved objects of the same class must have a contribution to the diffuse extragalactic gamma-ray background (EGRB). Understanding this component of the EGRB, along with other guaranteed contributions from known sources (blazars and normal galaxies), is essential if we are to use this emission to constrain exotic high-energy physics. Here, we follow an empirical approach to estimate whether the contribution of unresolved unidentified sources to the EGRB is likely to be important. Additionally, we discuss how upcoming GLAST observations of EGRET unidentified sources, their fainter counterparts, and the Galactic and extragalactic diffuse backgrounds, will shed light on the nature of the EGRET unidentified sources even without any positional association of such sources with low-energy counterparts

  16. Octopuses use a human-like strategy to control precise point-to-point arm movements.

    Science.gov (United States)

    Sumbre, Germán; Fiorito, Graziano; Flash, Tamar; Hochner, Binyamin

    2006-04-18

    One of the key problems in motor control is mastering or reducing the number of degrees of freedom (DOFs) through coordination. This problem is especially prominent with hyper-redundant limbs such as the extremely flexible arm of the octopus. Several strategies for simplifying these control problems have been suggested for human point-to-point arm movements. Despite the evolutionary gap and morphological differences, humans and octopuses evolved similar strategies when fetching food to the mouth. To achieve this precise point-to-point-task, octopus arms generate a quasi-articulated structure based on three dynamic joints. A rotational movement around these joints brings the object to the mouth . Here, we describe a peripheral neural mechanism-two waves of muscle activation propagate toward each other, and their collision point sets the medial-joint location. This is a remarkably simple mechanism for adjusting the length of the segments according to where the object is grasped. Furthermore, similar to certain human arm movements, kinematic invariants were observed at the joint level rather than at the end-effector level, suggesting intrinsic control coordination. The evolutionary convergence to similar geometrical and kinematic features suggests that a kinematically constrained articulated limb controlled at the level of joint space is the optimal solution for precise point-to-point movements.

  17. Study of landscape patterns of variation and optimization based on non-point source pollution control in an estuary.

    Science.gov (United States)

    Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui; Wu, Haiyan

    2014-10-15

    Appropriate increases in the "sink" of a landscape can reduce the risk of non-point source pollution (NPSP) to the sea at relatively lower costs and at a higher efficiency. Based on high-resolution remote sensing image data taken between 2003 and 2008, we analyzed the "source" and "sink" landscape pattern variations of nitrogen and phosphorus pollutants in the Jiulongjiang estuary region. The contribution to the sea and distribution of each pollutant in the region was calculated using the LCI and mGLCI models. The results indicated that an increased amount of pollutants was contributed to the sea, and the "source" area of the nitrogen NPSP in the study area increased by 32.75 km(2). We also propose a landscape pattern optimization to reduce pollution in the Jiulongjiang estuary in 2008 through the conversion of cultivated land with slopes greater than 15° and paddy fields near rivers, and an increase in mangrove areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Incorporation of Complex Hydrological and Socio-economic Factors for Non-point Source Pollution Control: A Case Study at the Yincungang Canal, the Lake Tai Basin of China

    Science.gov (United States)

    Yang, X.; Luo, X.; Zheng, Z.

    2012-04-01

    It is increasingly realized that non-point pollution sources contribute significantly to water environment deterioration in China. Compared to developed countries, non-point source pollution in China has the unique characteristics of strong intensity and composition complexity due to its special socioeconomic conditions. First, more than 50% of its 1.3 billion people are rural. Sewage from the majority of the rural households is discharged either without or only with minimal treatment. The large amount of erratic rural sewage discharge is a significant source of water pollution. Second, China is plagued with serious agricultural pollution due to widespread improper application of fertilizers and pesticides. Finally, there lack sufficient disposal and recycling of rural wastes such as livestock manure and crop straws. Pollutant loads from various sources have far exceeded environmental assimilation capacity in many parts of China. The Lake Tai basin is one typical example. Lake Tai is the third largest freshwater lake in China. The basin is located in the highly developed and densely populated Yangtze River Delta. While accounting for 0.4% of its land area and 2.9% of its population, the Lake Tai basin generates more than 14% of China's Gross Domestic Production (GDP), and the basin's GDP per capita is 3.5 times as much as the state average. Lake Tai is vital to the basin's socio-economic development, providing multiple services including water supply for municipal, industrial, and agricultural needs, navigation, flood control, fishery, and tourism. Unfortunately, accompanied with the fast economic development is serious water environment deterioration in the Lake Tai basin. The lake is becoming increasingly eutrophied and has frequently suffered from cyanobacterial blooms in recent decades. Chinese government has made tremendous investment in order to mitigate water pollution conditions in the basin. Nevertheless, the trend of deteriorating water quality has yet to

  19. Evaluation of the Agricultural Non-point Source Pollution in Chongqing Based on PSR Model

    Institute of Scientific and Technical Information of China (English)

    Hanwen; ZHANG; Xinli; MOU; Hui; XIE; Hong; LU; Xingyun; YAN

    2014-01-01

    Through a series of exploration based on PSR framework model,for the purpose of building a suitable Chongqing agricultural nonpoint source pollution evaluation index system model framework,combined with the presence of Chongqing specific agro-environmental issues,we build a agricultural non-point source pollution assessment index system,and then study the agricultural system pressure,agro-environmental status and human response in total 3 major categories,develope an agricultural non-point source pollution evaluation index consisting of 3 criteria indicators and 19 indicators. As can be seen from the analysis,pressures and responses tend to increase and decrease linearly,state and complex have large fluctuations,and their fluctuations are similar mainly due to the elimination of pressures and impact,increasing the impact for agricultural non-point source pollution.

  20. A modified likelihood-method to search for point-sources in the diffuse astrophysical neutrino-flux in IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, Rene; Haack, Christian; Leuermann, Martin; Raedel, Leif; Schoenen, Sebastian; Schimp, Michael; Wiebusch, Christopher [III. Physikalisches Institut, RWTH Aachen (Germany); Collaboration: IceCube-Collaboration

    2015-07-01

    IceCube, a cubic-kilometer sized neutrino detector at the geographical South Pole, has recently measured a flux of high-energy astrophysical neutrinos. Although this flux has now been observed in multiple analyses, no point sources or source classes could be identified yet. Standard point source searches test many points in the sky for a point source of astrophysical neutrinos individually and therefore produce many trials. Our approach is to additionally use the measured diffuse spectrum to constrain the number of possible point sources and their properties. Initial studies of the method performance are shown.

  1. [Nitrogen non-point source pollution identification based on ArcSWAT in Changle River].

    Science.gov (United States)

    Deng, Ou-Ping; Sun, Si-Yang; Lü, Jun

    2013-04-01

    The ArcSWAT (Soil and Water Assessment Tool) model was adopted for Non-point source (NPS) nitrogen pollution modeling and nitrogen source apportionment for the Changle River watershed, a typical agricultural watershed in Southeast China. Water quality and hydrological parameters were monitored, and the watershed natural conditions (including soil, climate, land use, etc) and pollution sources information were also investigated and collected for SWAT database. The ArcSWAT model was established in the Changle River after the calibrating and validating procedures of the model parameters. Based on the validated SWAT model, the contributions of different nitrogen sources to river TN loading were quantified, and spatial-temporal distributions of NPS nitrogen export to rivers were addressed. The results showed that in the Changle River watershed, Nitrogen fertilizer, nitrogen air deposition and nitrogen soil pool were the prominent pollution sources, which contributed 35%, 32% and 25% to the river TN loading, respectively. There were spatial-temporal variations in the critical sources for NPS TN export to the river. Natural sources, such as soil nitrogen pool and atmospheric nitrogen deposition, should be targeted as the critical sources for river TN pollution during the rainy seasons. Chemical nitrogen fertilizer application should be targeted as the critical sources for river TN pollution during the crop growing season. Chemical nitrogen fertilizer application, soil nitrogen pool and atmospheric nitrogen deposition were the main sources for TN exported from the garden plot, forest and residential land, respectively. However, they were the main sources for TN exported both from the upland and paddy field. These results revealed that NPS pollution controlling rules should focus on the spatio-temporal distribution of NPS pollution sources.

  2. Perturb and Observe Control for an Embedded Point Pivoted Absorber

    Directory of Open Access Journals (Sweden)

    Gianluca Brando

    2016-11-01

    Full Text Available Marine energy sources represent an attractive and inexhaustible reservoir able to contribute to the fulfillment of the world energy demand in accordance with climate/energy regulatory frameworks. Wave energy converter (WEC integration into the main grid requires both the maximization of the harvested energy and the proper management of the generation variability. The present paper focuses on both these mentioned issues. More specifically, it presents an embedded point pivoted absorber (PPA and its related control strategy aimed at maximizing the harvested energy. Experimental and numerical investigations have been carried out in a wave/towing tank facility in order to derive the design characteristics of the full-scale model and demonstrate the validity and effectiveness of the proposed control strategy.

  3. Comparison of Extremum-Seeking Control Techniques for Maximum Power Point Tracking in Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Chen-Han Wu

    2011-12-01

    Full Text Available Due to Japan’s recent nuclear crisis and petroleum price hikes, the search for renewable energy sources has become an issue of immediate concern. A promising candidate attracting much global attention is solar energy, as it is green and also inexhaustible. A maximum power point tracking (MPPT controller is employed in such a way that the output power provided by a photovoltaic (PV system is boosted to its maximum level. However, in the context of abrupt changes in irradiance, conventional MPPT controller approaches suffer from insufficient robustness against ambient variation, inferior transient response and a loss of output power as a consequence of the long duration required of tracking procedures. Accordingly, in this work the maximum power point tracking is carried out successfully using a sliding mode extremum-seeking control (SMESC method, and the tracking performances of three controllers are compared by simulations, that is, an extremum-seeking controller, a sinusoidal extremum-seeking controller and a sliding mode extremum-seeking controller. Being able to track the maximum power point promptly in the case of an abrupt change in irradiance, the SMESC approach is proven by simulations to be superior in terms of system dynamic and steady state responses, and an excellent robustness along with system stability is demonstrated as well.

  4. Effect of point source and heterogeneity on the propagation of ...

    African Journals Online (AJOL)

    user

    propagation of Love waves due to point source in a homogeneous layer overlying a ...... The dispersion equation of SH waves will be obtained by equating to zero the ..... He was Awarded Atomic Energy Fellowship by the Government of India.

  5. Spatiotemporal patterns of non-point source nitrogen loss in an agricultural catchment

    Directory of Open Access Journals (Sweden)

    Jian-feng Xu

    2016-04-01

    Full Text Available Non-point source nitrogen loss poses a risk to sustainable aquatic ecosystems. However, non-point sources, as well as impaired river segments with high nitrogen concentrations, are difficult to monitor and regulate because of their diffusive nature, budget constraints, and resource deficiencies. For the purpose of catchment management, the Bayesian maximum entropy approach and spatial regression models have been used to explore the spatiotemporal patterns of non-point source nitrogen loss. In this study, a total of 18 sampling sites were selected along the river network in the Hujiashan Catchment. Over the time period of 2008–2012, water samples were collected 116 times at each site and analyzed for non-point source nitrogen loss. The morphometric variables and soil drainage of different land cover types were studied and considered potential factors affecting nitrogen loss. The results revealed that, compared with the approach using the Euclidean distance, the Bayesian maximum entropy approach using the river distance led to an appreciable 10.1% reduction in the estimation error, and more than 53.3% and 44.7% of the river network in the dry and wet seasons, respectively, had a probability of non-point source nitrogen impairment. The proportion of the impaired river segments exhibited an overall decreasing trend in the study catchment from 2008 to 2012, and the reduction in the wet seasons was greater than that in the dry seasons. High nitrogen concentrations were primarily found in the downstream reaches and river segments close to the residential lands. Croplands and residential lands were the dominant factors affecting non-point source nitrogen loss, and explained up to 70.7% of total nitrogen in the dry seasons and 54.7% in the wet seasons. A thorough understanding of the location of impaired river segments and the dominant factors affecting total nitrogen concentration would have considerable importance for catchment management.

  6. Multi-angle Indicators System of Non-point Pollution Source Assessment in Rural Areas: A Case Study Near Taihu Lake

    Science.gov (United States)

    Huang, Lei; Ban, Jie; Han, Yu Ting; Yang, Jie; Bi, Jun

    2013-04-01

    This study aims to identify key environmental risk sources contributing to water eutrophication and to suggest certain risk management strategies for rural areas. The multi-angle indicators included in the risk source assessment system were non-point source pollution, deficient waste treatment, and public awareness of environmental risk, which combined psychometric paradigm methods, the contingent valuation method, and personal interviews to describe the environmental sensitivity of local residents. Total risk values of different villages near Taihu Lake were calculated in the case study, which resulted in a geographic risk map showing which village was the critical risk source of Taihu eutrophication. The increased application of phosphorus (P) and nitrogen (N), loss vulnerability of pollutant, and a lack of environmental risk awareness led to more serious non-point pollution, especially in rural China. Interesting results revealed by the quotient between the scores of objective risk sources and subjective risk sources showed what should be improved for each study village. More environmental investments, control of agricultural activities, and promotion of environmental education are critical considerations for rural environmental management. These findings are helpful for developing targeted and effective risk management strategies in rural areas.

  7. IceCube point source searches using through-going muon tracks

    Energy Technology Data Exchange (ETDEWEB)

    Coenders, Stefan [TU Muenchen, Physik-Department, Excellence Cluster Universe, Boltzmannstr. 2, 85748 Garching (Germany); Collaboration: IceCube-Collaboration

    2015-07-01

    The IceCube neutrino observatory located at the South Pole is the current largest neutrino telescope. Using through-going muon tracks, IceCube records approximately 130,000 events per year with reconstruction accuracy as low as 0.7 deg for energies of 10 TeV. Having analysed an integrated time-scale of 4 years, no sources of neutrinos have yet been observed. This talk deals with the current progress in point-source searches, adding another two years of data recorded in the years 2012 and 2013. In a combined search with starting events, sources of hard and soft spectra with- and with-out cut-offs are characterised.

  8. Broadband integrated mid infrared light sources as enabling technology for point of care mid-infrared spectroscopy

    Science.gov (United States)

    2017-08-20

    AFRL-AFOSR-JP-TR-2017-0061 Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy Alex...mid-infrared light sources as enabling technology for point-of-care mid-infrared spectroscopy 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-16-1-4037...Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy ” Date: 16th August 2017 Name

  9. Evaluation of spatial dependence of point spread function-based PET reconstruction using a traceable point-like 22Na source

    Directory of Open Access Journals (Sweden)

    Taisuke Murata

    2016-10-01

    Full Text Available Abstract Background The point spread function (PSF of positron emission tomography (PET depends on the position across the field of view (FOV. Reconstruction based on PSF improves spatial resolution and quantitative accuracy. The present study aimed to quantify the effects of PSF correction as a function of the position of a traceable point-like 22Na source over the FOV on two PET scanners with a different detector design. Methods We used Discovery 600 and Discovery 710 (GE Healthcare PET scanners and traceable point-like 22Na sources (<1 MBq with a spherical absorber design that assures uniform angular distribution of the emitted annihilation photons. The source was moved in three directions at intervals of 1 cm from the center towards the peripheral FOV using a three-dimensional (3D-positioning robot, and data were acquired over a period of 2 min per point. The PET data were reconstructed by filtered back projection (FBP, the ordered subset expectation maximization (OSEM, OSEM + PSF, and OSEM + PSF + time-of-flight (TOF. Full width at half maximum (FWHM was determined according to the NEMA method, and total counts in regions of interest (ROI for each reconstruction were quantified. Results The radial FWHM of FBP and OSEM increased towards the peripheral FOV, whereas PSF-based reconstruction recovered the FWHM at all points in the FOV of both scanners. The radial FWHM for PSF was 30–50 % lower than that of OSEM at the center of the FOV. The accuracy of PSF correction was independent of detector design. Quantitative values were stable across the FOV in all reconstruction methods. The effect of TOF on spatial resolution and quantitation accuracy was less noticeable. Conclusions The traceable 22Na point-like source allowed the evaluation of spatial resolution and quantitative accuracy across the FOV using different reconstruction methods and scanners. PSF-based reconstruction reduces dependence of the spatial resolution on the

  10. Diffusion of dust particles from a point-source above ground level

    International Nuclear Information System (INIS)

    Hassan, M.H.A.; Eltayeb, I.A.

    1998-10-01

    A pollutant of small particles is emitted by a point source at a height h above ground level in an atmosphere in which a uni-directional wind speed, U, is prevailing. The pollutant is subjected to diffusion in all directions in the presence of advection and settling due to gravity. The equation governing the concentration of the pollutant is studied with the wind speed and the different components of diffusion tensor are proportional to the distance above ground level and the source has a uniform strength. Adopting a Cartesian system of coordinates in which the x-axis lies along the direction of the wind velocity, the z-axis is vertically upwards and the y-axis completes the right-hand triad, the solution for the concentration c(x,y,z) is obtained in closed form. The relative importance of the components of diffusion along the three axes is discussed. It is found that for any plane y=constant (=A), c(x,y,z) is concentrated along a curve of ''extensive pollution''. In the plane A=0, the concentration decreases along the line of extensive pollution as we move away from the source. However, for planes A≅0, the line of extensive pollution possesses a point of accumulation, which lies at a nonzero value of x. As we move away from the plane A=0, the point of accumulation moves laterally away from the plane x=0 and towards the plane z=0. The presence of the point of accumulation is entirely due to the presence of lateral diffusion. (author)

  11. Simultaneous Determination of Source Wavelet and Velocity Profile Using Impulsive Point-Source Reflections from a Layered Fluid

    National Research Council Canada - National Science Library

    Bube, K; Lailly, P; Sacks, P; Santosa, F; Symes, W. W

    1987-01-01

    .... We show that a quasi-impulsive, isotropic point source may be recovered simultaneously with the velocity profile from reflection data over a layered fluid, in linear (perturbation) approximation...

  12. Atmospheric mercury dispersion modelling from two nearest hypothetical point sources

    Energy Technology Data Exchange (ETDEWEB)

    Al Razi, Khandakar Md Habib; Hiroshi, Moritomi; Shinji, Kambara [Environmental and Renewable Energy System (ERES), Graduate School of Engineering, Gifu University, Yanagido, Gifu City, 501-1193 (Japan)

    2012-07-01

    The Japan coastal areas are still environmentally friendly, though there are multiple air emission sources originating as a consequence of several developmental activities such as automobile industries, operation of thermal power plants, and mobile-source pollution. Mercury is known to be a potential air pollutant in the region apart from SOX, NOX, CO and Ozone. Mercury contamination in water bodies and other ecosystems due to deposition of atmospheric mercury is considered a serious environmental concern. Identification of sources contributing to the high atmospheric mercury levels will be useful for formulating pollution control and mitigation strategies in the region. In Japan, mercury and its compounds were categorized as hazardous air pollutants in 1996 and are on the list of 'Substances Requiring Priority Action' published by the Central Environmental Council of Japan. The Air Quality Management Division of the Environmental Bureau, Ministry of the Environment, Japan, selected the current annual mean environmental air quality standard for mercury and its compounds of 0.04 ?g/m3. Long-term exposure to mercury and its compounds can have a carcinogenic effect, inducing eg, Minamata disease. This study evaluates the impact of mercury emissions on air quality in the coastal area of Japan. Average yearly emission of mercury from an elevated point source in this area with background concentration and one-year meteorological data were used to predict the ground level concentration of mercury. To estimate the concentration of mercury and its compounds in air of the local area, two different simulation models have been used. The first is the National Institute of Advanced Science and Technology Atmospheric Dispersion Model for Exposure and Risk Assessment (AIST-ADMER) that estimates regional atmospheric concentration and distribution. The second is the Hybrid Single Particle Lagrangian Integrated trajectory Model (HYSPLIT) that estimates the atmospheric

  13. Radio identifications of IRAS point sources with b greater than 30 deg

    International Nuclear Information System (INIS)

    Condon, J.J.; Broderick, J.J.; Virginia Polytechnic Institute and State Univ., Blacksburg)

    1986-01-01

    The present radio identifications of IRAS point sources on the basis of Green Bank 1400 MHz survey maps notes that 365 hot IR sources are not detectable radio sources, and that nearly all cool high latitude IRAS sources are extragalactic. The fainter IR-source identifications encompass optically bright quasars, BL Lac objects, Seyfert galaxies, and elliptical galaxies. No IRAS sources could be identified with distant elliptical radio galaxies, so that although the radio and IR fluxes of most IRAS extragalactic sources are tightly correlated, complete samples of strong radio and IR sources are almost completely disjoint; no more than 1 percent of the IR sources are radio sources and less than 1 percent of the radio sources are IR ones. 35 references

  14. Miniature x-ray point source for alignment and calibration of x-ray optics

    International Nuclear Information System (INIS)

    Price, R.H.; Boyle, M.J.; Glaros, S.S.

    1977-01-01

    A miniature x-ray point source of high brightness similar to that of Rovinsky, et al. is described. One version of the x-ray source is used to align the x-ray optics on the Argus and Shiva laser systems. A second version is used to determine the spatial and spectral transmission functions of the x-ray optics. The spatial and spectral characteristics of the x-ray emission from the x-ray point source are described. The physical constraints including size, intensity and thermal limitations, and useful lifetime are discussed. The alignment and calibration techniques for various x-ray optics and detector combinations are described

  15. Device for dynamic switching of robot control points

    DEFF Research Database (Denmark)

    2015-01-01

    The invention comprises a system for switching between control points of a robotic system involving an industrial robot including a robot arm with a number of joints and provided with a tool interest point movable in a plurality of degrees of freedom.......The invention comprises a system for switching between control points of a robotic system involving an industrial robot including a robot arm with a number of joints and provided with a tool interest point movable in a plurality of degrees of freedom....

  16. Control Point Generated PLS - lines

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Control Point Generated PLS layer contains line and polygon features to the 1/4 of 1/4 PLS section (approximately 40 acres) and government lot level. The layer...

  17. Control Point Generated PLS - polygons

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Control Point Generated PLS layer contains line and polygon features to the 1/4 of 1/4 PLS section (approximately 40 acres) and government lot level. The layer...

  18. Search for point-like sources using the diffuse astrophysical muon-neutrino flux in IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, Rene; Haack, Christian; Raedel, Leif; Schoenen, Sebastian; Schumacher, Lisa; Wiebusch, Christopher [III. Physikalisches Institut B, RWTH Aachen (Germany); Collaboration: IceCube-Collaboration

    2016-07-01

    IceCube, a cubic-kilometer sized neutrino detector at the geographic South Pole, has recently confirmed a flux of high-energy astrophysical neutrinos in the track-like muon channel. Although this muon-neutrino flux has now been observed with high significance, no point sources or source classes could be identified yet with these well pointing events. We present a search for point-like sources based on a six year sample of upgoing muon-neutrinos with very low background contamination. To improve the sensitivity, the standard likelihood approach has been modified to focus on the properties of the measured astrophysical muon-neutrino flux.

  19. Multi-Class Simultaneous Adaptive Segmentation and Quality Control of Point Cloud Data

    Directory of Open Access Journals (Sweden)

    Ayman Habib

    2016-01-01

    Full Text Available 3D modeling of a given site is an important activity for a wide range of applications including urban planning, as-built mapping of industrial sites, heritage documentation, military simulation, and outdoor/indoor analysis of airflow. Point clouds, which could be either derived from passive or active imaging systems, are an important source for 3D modeling. Such point clouds need to undergo a sequence of data processing steps to derive the necessary information for the 3D modeling process. Segmentation is usually the first step in the data processing chain. This paper presents a region-growing multi-class simultaneous segmentation procedure, where planar, pole-like, and rough regions are identified while considering the internal characteristics (i.e., local point density/spacing and noise level of the point cloud in question. The segmentation starts with point cloud organization into a kd-tree data structure and characterization process to estimate the local point density/spacing. Then, proceeding from randomly-distributed seed points, a set of seed regions is derived through distance-based region growing, which is followed by modeling of such seed regions into planar and pole-like features. Starting from optimally-selected seed regions, planar and pole-like features are then segmented. The paper also introduces a list of hypothesized artifacts/problems that might take place during the region-growing process. Finally, a quality control process is devised to detect, quantify, and mitigate instances of partially/fully misclassified planar and pole-like features. Experimental results from airborne and terrestrial laser scanning as well as image-based point clouds are presented to illustrate the performance of the proposed segmentation and quality control framework.

  20. Compensation for loads during arm movements using equilibrium-point control.

    Science.gov (United States)

    Gribble, P L; Ostry, D J

    2000-12-01

    A significant problem in motor control is how information about movement error is used to modify control signals to achieve desired performance. A potential source of movement error and one that is readily controllable experimentally relates to limb dynamics and associated movement-dependent loads. In this paper, we have used a position control model to examine changes to control signals for arm movements in the context of movement-dependent loads. In the model, based on the equilibrium-point hypothesis, equilibrium shifts are adjusted directly in proportion to the positional error between desired and actual movements. The model is used to simulate multi-joint movements in the presence of both "internal" loads due to joint interaction torques, and externally applied loads resulting from velocity-dependent force fields. In both cases it is shown that the model can achieve close correspondence to empirical data using a simple linear adaptation procedure. An important feature of the model is that it achieves compensation for loads during movement without the need for either coordinate transformations between positional error and associated corrective forces, or inverse dynamics calculations.

  1. 四川省农村面源污染状况与治理对策研究%Environmental Protection Countermeasures Against Rural Non-point Pollution Sources in Sichuan Province

    Institute of Scientific and Technical Information of China (English)

    郭卫广; 雍毅; 陈杰; 吴怡; 薛嘉

    2016-01-01

    Rural non-point source pollution is mainly divided into agricultural non-point source, livestock excrement non-point source and rural life non-point source pollution. Based on the emission factor method, this study calculated the two main pollutants( COD and NH3 -N) emissions and researched on the environmental protection countermeasures against rural non-point source pollution. Agricultural non-point source pollution control measures include:promoting soil testing and fertilizer recommen-dation, scientific and safe use of pesticides, agricultural tail water collection and treatment, ecological interception technology, etc. Livestock and poultry non-point source pollution control measures include:strengthen the pollution control of small livestock and poultry farmers, integration of agriculture and husbandry for treating non -point source pollution, promoting dry cleaning process, fermentation bed treatment technology, etc. Rural life pollution control measures include:promoting the construction of rural sewage collection and treatment infrastructure, promoting the application of small sewage treatment facilities in rural areas, etc.%四川省农村面源主要分为农田面源、畜禽养殖粪便污染面源和农村生活污染面源,研究根据排放因子法计算了两种主要考核污染物化学需氧量和氨氮的排放量.根据四川省农村面源污染状况特征提出了面源治理对策措施,其中农田面源治理措施包括:推广测土配方施肥、农田面源生态拦截技术等;畜禽养殖污染治理措施包括:加强小型畜禽养殖污染治理,推广农牧结合、干清粪、发酵床处理工艺等;农村生活污染治理措施包括:推进农村生活污水收集及小型污水处理设施等.

  2. PSFGAN: a generative adversarial network system for separating quasar point sources and host galaxy light

    Science.gov (United States)

    Stark, Dominic; Launet, Barthelemy; Schawinski, Kevin; Zhang, Ce; Koss, Michael; Turp, M. Dennis; Sartori, Lia F.; Zhang, Hantian; Chen, Yiru; Weigel, Anna K.

    2018-06-01

    The study of unobscured active galactic nuclei (AGN) and quasars depends on the reliable decomposition of the light from the AGN point source and the extended host galaxy light. The problem is typically approached using parametric fitting routines using separate models for the host galaxy and the point spread function (PSF). We present a new approach using a Generative Adversarial Network (GAN) trained on galaxy images. We test the method using Sloan Digital Sky Survey r-band images with artificial AGN point sources added that are then removed using the GAN and with parametric methods using GALFIT. When the AGN point source is more than twice as bright as the host galaxy, we find that our method, PSFGAN, can recover point source and host galaxy magnitudes with smaller systematic error and a lower average scatter (49 per cent). PSFGAN is more tolerant to poor knowledge of the PSF than parametric methods. Our tests show that PSFGAN is robust against a broadening in the PSF width of ± 50 per cent if it is trained on multiple PSFs. We demonstrate that while a matched training set does improve performance, we can still subtract point sources using a PSFGAN trained on non-astronomical images. While initial training is computationally expensive, evaluating PSFGAN on data is more than 40 times faster than GALFIT fitting two components. Finally, PSFGAN is more robust and easy to use than parametric methods as it requires no input parameters.

  3. Is a wind turbine a point source? (L).

    Science.gov (United States)

    Makarewicz, Rufin

    2011-02-01

    Measurements show that practically all noise of wind turbine noise is produced by turbine blades, sometimes a few tens of meters long, despite that the model of a point source located at the hub height is commonly used. The plane of rotating blades is the critical location of the receiver because the distances to the blades are the shortest. It is shown that such location requires certain condition to be met. The model is valid far away from the wind turbine as well.

  4. Geodetic Control Points - MO 2014 Springfield Benchmarks (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Points that show set benchmark or survey control locations in the City of Springfield. Many of these points are PLS section corners and quarter corners. These points...

  5. Double point source W-phase inversion: Real-time implementation and automated model selection

    Science.gov (United States)

    Nealy, Jennifer; Hayes, Gavin

    2015-01-01

    Rapid and accurate characterization of an earthquake source is an extremely important and ever evolving field of research. Within this field, source inversion of the W-phase has recently been shown to be an effective technique, which can be efficiently implemented in real-time. An extension to the W-phase source inversion is presented in which two point sources are derived to better characterize complex earthquakes. A single source inversion followed by a double point source inversion with centroid locations fixed at the single source solution location can be efficiently run as part of earthquake monitoring network operational procedures. In order to determine the most appropriate solution, i.e., whether an earthquake is most appropriately described by a single source or a double source, an Akaike information criterion (AIC) test is performed. Analyses of all earthquakes of magnitude 7.5 and greater occurring since January 2000 were performed with extended analyses of the September 29, 2009 magnitude 8.1 Samoa earthquake and the April 19, 2014 magnitude 7.5 Papua New Guinea earthquake. The AIC test is shown to be able to accurately select the most appropriate model and the selected W-phase inversion is shown to yield reliable solutions that match published analyses of the same events.

  6. Temperature Effects of Point Sources, Riparian Shading, and Dam Operations on the Willamette River, Oregon

    Science.gov (United States)

    Rounds, Stewart A.

    2007-01-01

    Water temperature is an important factor influencing the migration, rearing, and spawning of several important fish species in rivers of the Pacific Northwest. To protect these fish populations and to fulfill its responsibilities under the Federal Clean Water Act, the Oregon Department of Environmental Quality set a water temperature Total Maximum Daily Load (TMDL) in 2006 for the Willamette River and the lower reaches of its largest tributaries in northwestern Oregon. As a result, the thermal discharges of the largest point sources of heat to the Willamette River now are limited at certain times of the year, riparian vegetation has been targeted for restoration, and upstream dams are recognized as important influences on downstream temperatures. Many of the prescribed point-source heat-load allocations are sufficiently restrictive that management agencies may need to expend considerable resources to meet those allocations. Trading heat allocations among point-source dischargers may be a more economical and efficient means of meeting the cumulative point-source temperature limits set by the TMDL. The cumulative nature of these limits, however, precludes simple one-to-one trades of heat from one point source to another; a more detailed spatial analysis is needed. In this investigation, the flow and temperature models that formed the basis of the Willamette temperature TMDL were used to determine a spatially indexed 'heating signature' for each of the modeled point sources, and those signatures then were combined into a user-friendly, spreadsheet-based screening tool. The Willamette River Point-Source Heat-Trading Tool allows the user to increase or decrease the heating signature of each source and thereby evaluate the effects of a wide range of potential point-source heat trades. The predictions of the Trading Tool were verified by running the Willamette flow and temperature models under four different trading scenarios, and the predictions typically were accurate

  7. Lessons Learned from OMI Observations of Point Source SO2 Pollution

    Science.gov (United States)

    Krotkov, N.; Fioletov, V.; McLinden, Chris

    2011-01-01

    The Ozone Monitoring Instrument (OMI) on NASA Aura satellite makes global daily measurements of the total column of sulfur dioxide (SO2), a short-lived trace gas produced by fossil fuel combustion, smelting, and volcanoes. Although anthropogenic SO2 signals may not be detectable in a single OMI pixel, it is possible to see the source and determine its exact location by averaging a large number of individual measurements. We describe new techniques for spatial and temporal averaging that have been applied to the OMI SO2 data to determine the spatial distributions or "fingerprints" of SO2 burdens from top 100 pollution sources in North America. The technique requires averaging of several years of OMI daily measurements to observe SO2 pollution from typical anthropogenic sources. We found that the largest point sources of SO2 in the U.S. produce elevated SO2 values over a relatively small area - within 20-30 km radius. Therefore, one needs higher than OMI spatial resolution to monitor typical SO2 sources. TROPOMI instrument on the ESA Sentinel 5 precursor mission will have improved ground resolution (approximately 7 km at nadir), but is limited to once a day measurement. A pointable geostationary UVB spectrometer with variable spatial resolution and flexible sampling frequency could potentially achieve the goal of daily monitoring of SO2 point sources and resolve downwind plumes. This concept of taking the measurements at high frequency to enhance weak signals needs to be demonstrated with a GEOCAPE precursor mission before 2020, which will help formulating GEOCAPE measurement requirements.

  8. Pointing control for LDR

    Science.gov (United States)

    Yam, Y.; Briggs, C.

    1988-01-01

    One important aspect of the LDR control problem is the possible excitations of structural modes due to random disturbances, mirror chopping, and slewing maneuvers. An analysis was performed to yield a first order estimate of the effects of such dynamic excitations. The analysis involved a study of slewing jitters, chopping jitters, disturbance responses, and pointing errors, making use of a simplified planar LDR model which describes the LDR dynamics on a plane perpendicular to the primary reflector. Briefly, the results indicate that the command slewing profile plays an important role in minimizing the resultant jitter, even to a level acceptable without any control action. An optimal profile should therefore be studied.

  9. Space Telescope Pointing Control System software

    Science.gov (United States)

    Dougherty, H.; Rodoni, C.; Rossini, R.; Tompetrini, K.; Nakashima, A.; Bradley, A.

    1982-01-01

    The Space Telescope Pointing Control System software is in the advanced development stage, having been tested on both the airbearing and the static simulator. The overall structure of the software is discussed, along with timing and sizing evaluations. The interaction between the controls analysts and software designer is described.

  10. Identifying populations at risk from environmental contamination from point sources

    OpenAIRE

    Williams, F; Ogston, S

    2002-01-01

    Objectives: To compare methods for defining the population at risk from a point source of air pollution. A major challenge for environmental epidemiology lies in correctly identifying populations at risk from exposure to environmental pollutants. The complexity of today's environment makes it essential that the methods chosen are accurate and sensitive.

  11. Applicability of a desiccant dew-point cooling system independent of external water sources

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Kærn, Martin Ryhl

    2015-01-01

    The applicability of a technical solution for making desiccant cooling systems independent of external water sources is investigated. Water is produced by condensing the desorbed water vapour in a closed regeneration circuit. Desorbed water recovery is applied to a desiccant dew-point cooling...... system, which includes a desiccant wheel and a dew point cooler. The system is simulated during the summer period in the Mediterranean climate of Rome and it results completely independent of external water sources. The seasonal thermal COP drops 8% in comparison to the open regeneration circuit solution...

  12. An effective dose assessment technique with NORM added consumer products using skin-point source on computational human phantom

    International Nuclear Information System (INIS)

    Yoo, Do Hyeon; Shin, Wook-Geun; Lee, Hyun Cheol; Choi, Hyun Joon; Testa, Mauro; Lee, Jae Kook; Yeom, Yeon Soo; Kim, Chan Hyeong; Min, Chul Hee

    2016-01-01

    The aim of this study is to develop the assessment technique of the effective dose by calculating the organ equivalent dose with a Monte Carlo (MC) simulation and a computational human phantom for the naturally occurring radioactive material (NORM) added consumer products. In this study, we suggests the method determining the MC source term based on the skin-point source enabling the convenient and conservative modeling of the various type of the products. To validate the skin-point source method, the organ equivalent doses were compared with that by the product modeling source of the realistic shape for the pillow, waist supporter, sleeping mattress etc. Our results show that according to the source location, the organ equivalent doses were observed as the similar tendency for both source determining methods, however, it was observed that the annual effective dose with the skin-point source was conservative than that with the modeling source with the maximum 3.3 times higher dose. With the assumption of the gamma energy of 1 MeV and product activity of 1 Bq g"−"1, the annual effective doses of the pillow, waist supporter and sleeping mattress with skin-point source was 3.09E-16 Sv Bq"−"1 year"−"1, 1.45E-15 Sv Bq"−"1 year"−"1, and 2,82E-16 Sv Bq"−"1 year"−"1, respectively, while the product modeling source showed 9.22E-17 Sv Bq"−"1 year"−"1, 9.29E-16 Sv Bq"−"1 year"−"1, and 8.83E-17 Sv Bq"−"1 year"−"1, respectively. In conclusion, it was demonstrated in this study that the skin-point source method could be employed to efficiently evaluate the annual effective dose due to the usage of the NORM added consumer products. - Highlights: • We evaluate the exposure dose from the usage of NORM added consumer products. • We suggest the method determining the MC source term based on the skin-point source. • To validate the skin-point source, the organ equivalent doses were compared with that the modeling source. • The skin-point source could

  13. Mobile point sensors and actuators in the controllability theory of partial differential equations

    CERN Document Server

    Khapalov, Alexander Y

    2017-01-01

    This book presents a concise study of controllability theory of partial differential equations when they are equipped with actuators and/or sensors that are finite dimensional at every moment of time. Based on the author’s extensive research in the area of controllability theory, this monograph specifically focuses on the issues of controllability, observability, and stabilizability for parabolic and hyperbolic partial differential equations. The topics in this book also cover related applied questions such as the problem of localization of unknown pollution sources based on information obtained from point sensors that arise in environmental monitoring. Researchers and graduate students interested in controllability theory of partial differential equations and its applications will find this book to be an invaluable resource to their studies.

  14. Preparation of very small point sources for high resolution radiography

    International Nuclear Information System (INIS)

    Case, F.N.

    1976-01-01

    The need for very small point sources of high specific activity 192 Ir, 169 Yb, 170 Tm, and 60 Co in non-destructive testing has motivated the development of techniques for the fabrication of these sources. To prepare 192 Ir point sources for use in examination of tube sheet welds in LMFBR heat exchangers, 191 Ir enriched to greater than 90 percent was melted in a helium blanketed arc to form spheres as small as 0.38 mm in diameter. Methods were developed to form the roughly spherical shaped arc product into nearly symmetrical spheres that could be used for high resolution radiography. Similar methods were used for spherical shaped sources of 169 Yb and 170 Tm. The oxides were arc melted to form rough spheres followed by grinding to precise dimensions, neutron irradiation of the spheres at a flux of 2 to 3 x 10 15 nv, and use of enriched 168 Yb to provide the maximum specific activity. Cobalt-60 with a specific activity of greater than 1100 Ci/g was prepared by processing 59 Co that had been neutron irradiated to nearly complete burnup of the 59 Co target to produce 60 Co, 61 Ni, and 62 Ni. Ion exchange methods were used to separate the cobalt from the nickel. The cobalt was reduced to metal by plating either onto aluminum foil which was dissolved away from the cobalt plate, or by plating onto mercury to prepare amalgam that could be easily formed into a pellet of cobalt with exclusion of the mercury. Both methods are discussed

  15. A new three-dimensional nonscanning laser imaging system based on the illumination pattern of a point-light-source array

    Science.gov (United States)

    Xia, Wenze; Ma, Yayun; Han, Shaokun; Wang, Yulin; Liu, Fei; Zhai, Yu

    2018-06-01

    One of the most important goals of research on three-dimensional nonscanning laser imaging systems is the improvement of the illumination system. In this paper, a new three-dimensional nonscanning laser imaging system based on the illumination pattern of a point-light-source array is proposed. This array is obtained using a fiber array connected to a laser array with each unit laser having independent control circuits. This system uses a point-to-point imaging process, which is realized using the exact corresponding optical relationship between the point-light-source array and a linear-mode avalanche photodiode array detector. The complete working process of this system is explained in detail, and the mathematical model of this system containing four equations is established. A simulated contrast experiment and two real contrast experiments which use the simplified setup without a laser array are performed. The final results demonstrate that unlike a conventional three-dimensional nonscanning laser imaging system, the proposed system meets all the requirements of an eligible illumination system. Finally, the imaging performance of this system is analyzed under defocusing situations, and analytical results show that the system has good defocusing robustness and can be easily adjusted in real applications.

  16. Control of sealed radioactive sources in Peru

    International Nuclear Information System (INIS)

    Ramirez Quijada, R.

    2001-01-01

    The paper describes the inventory of radioactive sources in Peru and assesses the control. Three groups of source conditions are established: controlled sources, known sources, and lost and orphan sources. The potential risk, described as not significant, for producing accidents is established and the needed measures are discussed. The paper concludes that, while the control on sealed sources is good, there is still room for improvement. (author)

  17. Diffusion from a point source in an urban atmosphere

    International Nuclear Information System (INIS)

    Essa, K.S.M.; El-Otaify, M.S.

    2005-01-01

    In the present paper, a model for the diffusion of material from a point source in an urban atmosphere is incorporated. The plume is assumed to have a well-defined edge at which the concentration falls to zero. The vertical wind shear is estimated using logarithmic law, by employing most of the available techniques of stability categories. The concentrations estimated from the model were compared favorably with the field observations of other investigators

  18. Study on the quantitative relationship between Agricultural water and fertilization process and non-point source pollution based on field experiments

    Science.gov (United States)

    Wang, H.; Chen, K.; Wu, Z.; Guan, X.

    2017-12-01

    increased the most in July. The results provide some basis for the field control and management of agricultural non-point source pollution.

  19. IceCube-Gen2 sensitivity improvement for steady neutrino point sources

    Energy Technology Data Exchange (ETDEWEB)

    Coenders, Stefan; Resconi, Elisa [TU Muenchen, Physik-Department, Excellence Cluster Universe, Boltzmannstr. 2, 85748 Garching (Germany); Collaboration: IceCube-Collaboration

    2015-07-01

    The observation of an astrophysical neutrino flux by high-energy events starting in IceCube strengthens the search for sources of astrophysical neutrinos. Identification of these sources requires good pointing at high statistics, mainly using muons created by charged-current muon neutrino interactions going through the IceCube detector. We report about preliminary studies of a possible high-energy extension IceCube-Gen2. Using a 6 times bigger detection volume, effective area as well as reconstruction accuracy will improve with respect to IceCube. Moreover, using (in-ice) active veto techniques will significantly improve the performance for Southern hemisphere events, where possible local candidate neutrino sources are located.

  20. HYDROLOGY AND SEDIMENT MODELING USING THE BASINS NON-POINT SOURCE MODEL

    Science.gov (United States)

    The Non-Point Source Model (Hydrologic Simulation Program-Fortran, or HSPF) within the EPA Office of Water's BASINS watershed modeling system was used to simulate streamflow and total suspended solids within Contentnea Creek, North Carolina, which is a tributary of the Neuse Rive...

  1. Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509–67.5

    Energy Technology Data Exchange (ETDEWEB)

    Litke, Katrina C.; Chu, You-Hua; Holmes, Abigail; Santucci, Robert; Blindauer, Terrence; Gruendl, Robert A.; Ricker, Paul M. [Astronomy Department, University of Illinois, 1002 W. Green Street, Urbana, IL 61801 (United States); Li, Chuan-Jui [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan, R.O.C. (China); Pan, Kuo-Chuan [Departement Physik, Universität Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Weisz, Daniel R., E-mail: kclitke@email.arizona.edu [Department of Astronomy, University of California, 501 Cambell Hall #3411, Berkeley, CA 94720-3411 (United States)

    2017-03-10

    We examine a diffuse emission region near the center of SNR 0509−67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Ly α , H α , and [O ii] λ 3727. We examine the spectral energy distribution (SED) of the source, comprised of Hubble Space Telescope B , V , I , J , and H bands in addition to Spitzer /IRAC 3.6, 4.5, 5.8, and 8 μ m bands. The peak of the SED is consistent with a background galaxy at z ≈ 0.8 ± 0.2 and a possible Balmer jump places the galaxy at z ≈ 0.9 ± 0.3. These SED considerations support the emission line’s identification as [O ii] λ 3727. We conclude that the diffuse source in SNR 0509−67.5 is a background galaxy at z ≈ 0.82. Furthermore, we identify the point-like source superposed near the center of the galaxy as its central bulge. Finally, we find no evidence for a surviving companion star, indicating a double-degenerate origin for SNR 0509−67.5.

  2. Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509–67.5

    International Nuclear Information System (INIS)

    Litke, Katrina C.; Chu, You-Hua; Holmes, Abigail; Santucci, Robert; Blindauer, Terrence; Gruendl, Robert A.; Ricker, Paul M.; Li, Chuan-Jui; Pan, Kuo-Chuan; Weisz, Daniel R.

    2017-01-01

    We examine a diffuse emission region near the center of SNR 0509−67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Ly α , H α , and [O ii] λ 3727. We examine the spectral energy distribution (SED) of the source, comprised of Hubble Space Telescope B , V , I , J , and H bands in addition to Spitzer /IRAC 3.6, 4.5, 5.8, and 8 μ m bands. The peak of the SED is consistent with a background galaxy at z ≈ 0.8 ± 0.2 and a possible Balmer jump places the galaxy at z ≈ 0.9 ± 0.3. These SED considerations support the emission line’s identification as [O ii] λ 3727. We conclude that the diffuse source in SNR 0509−67.5 is a background galaxy at z ≈ 0.82. Furthermore, we identify the point-like source superposed near the center of the galaxy as its central bulge. Finally, we find no evidence for a surviving companion star, indicating a double-degenerate origin for SNR 0509−67.5.

  3. 靖江市农业面源污染现状及防治对策研究%Current Status and Countermeasures of Agriculture Non-point Source Pollution control in Xinhua City

    Institute of Scientific and Technical Information of China (English)

    张明; 曹学章

    2016-01-01

    农业面源污染治理情况是生态文明创建的重要指标之一。本文总结了江苏省靖江市在生态市创建过程中治理农业面源污染所采取的措施以及取得的成效,并提出了靖江市“十三五”期间创建生态文明示范市过程中推进农业面源污染治理工作的对策建议:一,推广种植业清洁生产,控制种植业化肥农药使用;第二,优化养殖业布局,加强畜禽粪污综合利用;第三,调整渔业产业结构,强化水产养殖业污染管控;第四,推进农村环境综合整治。%Agricultural non-point source pollution is one of the important indicators during the construction of ecological civilization. This paper summarizes the measures taken by the management of agricultural non-point source pollution in Jingjiang during the construction of National Eco-city, and the results obtained. Then, it puts forward countermeasures and suggestions for promoting the pollution control of agricultural non-point source in Jingjiang during the 13’ th Five Year. First, the promotion of planting industry clean production, control the farming fertilizer pesticide use; Second, optimize the breeding industry layout, strengthen the comprehensive utilization of livestock and poultry waste; Third, adjust the structure of fishery industry, strengthen the aquaculture pollution control; Fourth, to promote the comprehensive improvement of the rural environment.

  4. Optimized Latching Control of Floating Point Absorber Wave Energy Converter

    Science.gov (United States)

    Gadodia, Chaitanya; Shandilya, Shubham; Bansal, Hari Om

    2018-03-01

    There is an increasing demand for energy in today’s world. Currently main energy resources are fossil fuels, which will eventually drain out, also the emissions produced from them contribute to global warming. For a sustainable future, these fossil fuels should be replaced with renewable and green energy sources. Sea waves are a gigantic and undiscovered vitality asset. The potential for extricating energy from waves is extensive. To trap this energy, wave energy converters (WEC) are needed. There is a need for increasing the energy output and decreasing the cost requirement of these existing WECs. This paper presents a method which uses prediction as a part of the control scheme to increase the energy efficiency of the floating-point absorber WECs. Kalman Filter is used for estimation, coupled with latching control in regular as well as irregular sea waves. Modelling and Simulation results for the same are also included.

  5. Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

    Science.gov (United States)

    Othman, Ahmed M.; El-arini, Mahdi M. M.; Ghitas, Ahmed; Fathy, Ahmed

    2012-12-01

    In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV) systems. Maximum power point tracking (MPPT) plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT) using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O) algorithm and is compared to a designed fuzzy logic controller (FLC). The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

  6. Fixed Point Learning Based Intelligent Traffic Control System

    Science.gov (United States)

    Zongyao, Wang; Cong, Sui; Cheng, Shao

    2017-10-01

    Fixed point learning has become an important tool to analyse large scale distributed system such as urban traffic network. This paper presents a fixed point learning based intelligence traffic network control system. The system applies convergence property of fixed point theorem to optimize the traffic flow density. The intelligence traffic control system achieves maximum road resources usage by averaging traffic flow density among the traffic network. The intelligence traffic network control system is built based on decentralized structure and intelligence cooperation. No central control is needed to manage the system. The proposed system is simple, effective and feasible for practical use. The performance of the system is tested via theoretical proof and simulations. The results demonstrate that the system can effectively solve the traffic congestion problem and increase the vehicles average speed. It also proves that the system is flexible, reliable and feasible for practical use.

  7. Decreasing Computational Time for VBBinaryLensing by Point Source Approximation

    Science.gov (United States)

    Tirrell, Bethany M.; Visgaitis, Tiffany A.; Bozza, Valerio

    2018-01-01

    The gravitational lens of a binary system produces a magnification map that is more intricate than a single object lens. This map cannot be calculated analytically and one must rely on computational methods to resolve. There are generally two methods of computing the microlensed flux of a source. One is based on ray-shooting maps (Kayser, Refsdal, & Stabell 1986), while the other method is based on an application of Green’s theorem. This second method finds the area of an image by calculating a Riemann integral along the image contour. VBBinaryLensing is a C++ contour integration code developed by Valerio Bozza, which utilizes this method. The parameters at which the source object could be treated as a point source, or in other words, when the source is far enough from the caustic, was of interest to substantially decrease the computational time. The maximum and minimum values of the caustic curves produced, were examined to determine the boundaries for which this simplification could be made. The code was then run for a number of different maps, with separation values and accuracies ranging from 10-1 to 10-3, to test the theoretical model and determine a safe buffer for which minimal error could be made for the approximation. The determined buffer was 1.5+5q, with q being the mass ratio. The theoretical model and the calculated points worked for all combinations of the separation values and different accuracies except the map with accuracy and separation equal to 10-3 for y1 max. An alternative approach has to be found in order to accommodate a wider range of parameters.

  8. A Single Phase Doubly Grounded Semi-Z-Source Inverter for Photovoltaic (PV Systems with Maximum Power Point Tracking (MPPT

    Directory of Open Access Journals (Sweden)

    Tofael Ahmed

    2014-06-01

    Full Text Available In this paper, a single phase doubly grounded semi-Z-source inverter with maximum power point tracking (MPPT is proposed for photovoltaic (PV systems. This proposed system utilizes a single-ended primary inductor (SEPIC converter as DC-DC converter to implement the MPPT algorithm for tracking the maximum power from a PV array and a single phase semi-Z-source inverter for integrating the PV with AC power utilities. The MPPT controller utilizes a fast-converging algorithm to track the maximum power point (MPP and the semi-Z-source inverter utilizes a nonlinear SPWM to produce sinusoidal voltage at the output. The proposed system is able to track the MPP of PV arrays and produce an AC voltage at its output by utilizing only three switches. Experimental results show that the fast-converging MPPT algorithm has fast tracking response with appreciable MPP efficiency. In addition, the inverter shows the minimization of common mode leakage current with its ground sharing feature and reduction of the THD as well as DC current components at the output during DC-AC conversion.

  9. 75 FR 10438 - Effluent Limitations Guidelines and Standards for the Construction and Development Point Source...

    Science.gov (United States)

    2010-03-08

    ... Effluent Limitations Guidelines and Standards for the Construction and Development Point Source Category... technology-based Effluent Limitations Guidelines and New Source Performance Standards for the Construction... technology-based Effluent Limitations Guidelines and New Source Performance Standards for the Construction...

  10. Washing and chilling as critical control points in pork slaughter hazard analysis and critical control point (HACCP) systems.

    Science.gov (United States)

    Bolton, D J; Pearce, R A; Sheridan, J J; Blair, I S; McDowell, D A; Harrington, D

    2002-01-01

    The aim of this research was to examine the effects of preslaughter washing, pre-evisceration washing, final carcass washing and chilling on final carcass quality and to evaluate these operations as possible critical control points (CCPs) within a pork slaughter hazard analysis and critical control point (HACCP) system. This study estimated bacterial numbers (total viable counts) and the incidence of Salmonella at three surface locations (ham, belly and neck) on 60 animals/carcasses processed through a small commercial pork abattoir (80 pigs d(-1)). Significant reductions (P HACCP in pork slaughter plants. This research will provide a sound scientific basis on which to develop and implement effective HACCP in pork abattoirs.

  11. The Unicellular State as a Point Source in a Quantum Biological System

    Directory of Open Access Journals (Sweden)

    John S. Torday

    2016-05-01

    Full Text Available A point source is the central and most important point or place for any group of cohering phenomena. Evolutionary development presumes that biological processes are sequentially linked, but neither directed from, nor centralized within, any specific biologic structure or stage. However, such an epigenomic entity exists and its transforming effects can be understood through the obligatory recapitulation of all eukaryotic lifeforms through a zygotic unicellular phase. This requisite biological conjunction can now be properly assessed as the focal point of reconciliation between biology and quantum phenomena, illustrated by deconvoluting complex physiologic traits back to their unicellular origins.

  12. Deghosting, Demultiple, and Deblurring in Controlled-Source Seismic Interferometry

    Directory of Open Access Journals (Sweden)

    Joost van der Neut

    2011-01-01

    Full Text Available With controlled-source seismic interferometry we aim to redatum sources to downhole receiver locations without requiring a velocity model. Interferometry is generally based on a source integral over cross-correlation (CC pairs of full, perturbed (time-gated, or decomposed wavefields. We provide an overview of ghosts, multiples, and spatial blurring effects that can occur for different types of interferometry. We show that replacing cross-correlation by multidimensional deconvolution (MDD can deghost, demultiple, and deblur retrieved data. We derive and analyze MDD for perturbed and decomposed wavefields. An interferometric point spread function (PSF is introduced that can be obtained directly from downhole data. Ghosts, multiples, and blurring effects that may populate the retrieved gathers can be locally diagnosed with the PSF. MDD of perturbed fields can remove ghosts and deblur retrieved data, but it leaves particular multiples in place. To remove all overburden-related effects, MDD of decomposed fields should be applied.

  13. Calibrate the aerial surveying instrument by the limited surface source and the single point source that replace the unlimited surface source

    CERN Document Server

    Lu Cun Heng

    1999-01-01

    It is described that the calculating formula and surveying result is found on the basis of the stacking principle of gamma ray and the feature of hexagonal surface source when the limited surface source replaces the unlimited surface source to calibrate the aerial survey instrument on the ground, and that it is found in the light of the exchanged principle of the gamma ray when the single point source replaces the unlimited surface source to calibrate aerial surveying instrument in the air. Meanwhile through the theoretical analysis, the receiving rate of the crystal bottom and side surfaces is calculated when aerial surveying instrument receives gamma ray. The mathematical expression of the gamma ray decaying following height according to the Jinge function regularity is got. According to this regularity, the absorbing coefficient that air absorbs the gamma ray and the detective efficiency coefficient of the crystal is calculated based on the ground and air measuring value of the bottom surface receiving cou...

  14. Effect of tissue inhomogeneity on dose distribution of point sources of low-energy electrons

    International Nuclear Information System (INIS)

    Kwok, C.S.; Bialobzyski, P.J.; Yu, S.K.; Prestwich, W.V.

    1990-01-01

    Perturbation in dose distributions of point sources of low-energy electrons at planar interfaces of cortical bone (CB) and red marrow (RM) was investigated experimentally and by Monte Carlo codes EGS and the TIGER series. Ultrathin LiF thermoluminescent dosimeters were used to measure the dose distributions of point sources of 204 Tl and 147 Pm in RM. When the point sources were at 12 mg/cm 2 from a planar interface of CB and RM equivalent plastics, dose enhancement ratios in RM averaged over the region 0--12 mg/cm 2 from the interface were measured to be 1.08±0.03 (SE) and 1.03±0.03 (SE) for 204 Tl and 147 Pm, respectively. The Monte Carlo codes predicted 1.05±0.02 and 1.01±0.02 for the two nuclides, respectively. However, EGS gave consistently 3% higher dose in the dose scoring region than the TIGER series when point sources of monoenergetic electrons up to 0.75 MeV energy were considered in the homogeneous RM situation or in the CB and RM heterogeneous situation. By means of the TIGER series, it was demonstrated that aluminum, which is normally assumed to be equivalent to CB in radiation dosimetry, leads to an overestimation of backscattering of low-energy electrons in soft tissue at a CB--soft-tissue interface by as much as a factor of 2

  15. Pressure Points: Preventing and Controlling Hypertension

    Science.gov (United States)

    ... Issue Past Issues Pressure Points: Preventing and Controlling Hypertension Past Issues / Summer 2006 Table of Contents For ... diagnosed with high blood pressure." Aditional Information On Hypertension MedlinePlus: High blood pressure: http://www.nlm.nih. ...

  16. Neutron generator tube ion source control

    International Nuclear Information System (INIS)

    Bridges, J.R.

    1982-01-01

    A system is claimed for controlling the output of a neutron generator tube of the deuterium-tritium accelerator type and having an ion source to produce sharply defined pulses of neutrons for well logging use. It comprises: means for inputting a relatively low voltage input control pulse having a leading edge and a trailing edge; means, responsive to the input control pulse, for producing a relatively high voltage ion source voltage pulse after receipt of the input pulse; and means, responsive to the input control pulse, for quenching, after receipt of the input pulse, the ion source control pulse, thereby providing a sharply time defined neutron output from the generator tube

  17. PSFGAN: a generative adversarial network system for separating quasar point sources and host galaxy light

    Science.gov (United States)

    Stark, Dominic; Launet, Barthelemy; Schawinski, Kevin; Zhang, Ce; Koss, Michael; Turp, M. Dennis; Sartori, Lia F.; Zhang, Hantian; Chen, Yiru; Weigel, Anna K.

    2018-03-01

    The study of unobscured active galactic nuclei (AGN) and quasars depends on the reliable decomposition of the light from the AGN point source and the extended host galaxy light. The problem is typically approached using parametric fitting routines using separate models for the host galaxy and the point spread function (PSF). We present a new approach using a Generative Adversarial Network (GAN) trained on galaxy images. We test the method using Sloan Digital Sky Survey (SDSS) r-band images with artificial AGN point sources added which are then removed using the GAN and with parametric methods using GALFIT. When the AGN point source PS is more than twice as bright as the host galaxy, we find that our method, PSFGAN, can recover PS and host galaxy magnitudes with smaller systematic error and a lower average scatter (49%). PSFGAN is more tolerant to poor knowledge of the PSF than parametric methods. Our tests show that PSFGAN is robust against a broadening in the PSF width of ±50% if it is trained on multiple PSF's. We demonstrate that while a matched training set does improve performance, we can still subtract point sources using a PSFGAN trained on non-astronomical images. While initial training is computationally expensive, evaluating PSFGAN on data is more than 40 times faster than GALFIT fitting two components. Finally, PSFGAN it is more robust and easy to use than parametric methods as it requires no input parameters.

  18. Pointing control using a moving base of support.

    Science.gov (United States)

    Hondzinski, Jan M; Kwon, Taegyong

    2009-07-01

    The purposes of this study were to determine whether gaze direction provides a control signal for movement direction for a pointing task requiring a step and to gain insight into why discrepancies previously identified in the literature for endpoint accuracy with gaze directed eccentrically exist. Straight arm pointing movements were performed to real and remembered target locations, either toward or 30 degrees eccentric to gaze direction. Pointing occurred in normal room lighting or darkness while subjects sat, stood still or side-stepped left or right. Trunk rotation contributed 22-65% to gaze orientations when it was not constrained. Error differences for different target locations explained discrepancies among previous experiments. Variable pointing errors were influenced by gaze direction, while mean systematic pointing errors and trunk orientations were influenced by step direction. These data support the use of a control strategy that relies on gaze direction and equilibrium inputs for whole-body goal-directed movements.

  19. Realworld maximum power point tracking simulation of PV system based on Fuzzy Logic control

    Directory of Open Access Journals (Sweden)

    Ahmed M. Othman

    2012-12-01

    Full Text Available In the recent years, the solar energy becomes one of the most important alternative sources of electric energy, so it is important to improve the efficiency and reliability of the photovoltaic (PV systems. Maximum power point tracking (MPPT plays an important role in photovoltaic power systems because it maximize the power output from a PV system for a given set of conditions, and therefore maximize their array efficiency. This paper presents a maximum power point tracker (MPPT using Fuzzy Logic theory for a PV system. The work is focused on the well known Perturb and Observe (P&O algorithm and is compared to a designed fuzzy logic controller (FLC. The simulation work dealing with MPPT controller; a DC/DC Ćuk converter feeding a load is achieved. The results showed that the proposed Fuzzy Logic MPPT in the PV system is valid.

  20. Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania

    Science.gov (United States)

    Grazhdani, Dorina

    2015-07-01

    Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods—dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was €6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.

  1. Simulation of ultrasonic surface waves with multi-Gaussian and point source beam models

    International Nuclear Information System (INIS)

    Zhao, Xinyu; Schmerr, Lester W. Jr.; Li, Xiongbing; Sedov, Alexander

    2014-01-01

    In the past decade, multi-Gaussian beam models have been developed to solve many complicated bulk wave propagation problems. However, to date those models have not been extended to simulate the generation of Rayleigh waves. Here we will combine Gaussian beams with an explicit high frequency expression for the Rayleigh wave Green function to produce a three-dimensional multi-Gaussian beam model for the fields radiated from an angle beam transducer mounted on a solid wedge. Simulation results obtained with this model are compared to those of a point source model. It is shown that the multi-Gaussian surface wave beam model agrees well with the point source model while being computationally much more efficient

  2. Regulatory Control of Radioactive Sources in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M.; Martin, J.L., E-mail: mrm@csn.es [Nuclear Safety Council, Madrid (Spain)

    2011-07-15

    The arrangements for the regulatory control of the safety and security of sealed radioactive sources in Spain are described. Emphasis is given to the situations which are most likely to result in the loss of control of sources and on the procedures introduced to reduce the likelihood of losses in these cases. Finally, the strategy for locating sources which have been lost from control (orphan sources) is described. (author)

  3. Time dependence of the field energy densities surrounding sources: Application to scalar mesons near point sources and to electromagnetic fields near molecules

    International Nuclear Information System (INIS)

    Persico, F.; Power, E.A.

    1987-01-01

    The time dependence of the dressing-undressing process, i.e., the acquiring or losing by a source of a boson field intensity and hence of a field energy density in its neighborhood, is considered by examining some simple soluble models. First, the loss of the virtual field is followed in time when a point source is suddenly decoupled from a neutral scalar meson field. Second, an initially bare point source acquires a virtual meson cloud as the coupling is switched on. The third example is that of an initially bare molecule interacting with the vacuum of the electromagnetic field to acquire a virtual photon cloud. In all three cases the dressing-undressing is shown to take place within an expanding sphere of radius r = ct centered at the source. At each point in space the energy density tends, for large times, to that of the ground state of the total system. Differences in the time dependence of the dressing between the massive scalar field and the massless electromagnetic field are discussed. The results are also briefly discussed in the light of Feinberg's ideas on the nature of half-dressed states in quantum field theory

  4. Fast and Accurate Rat Head Motion Tracking With Point Sources for Awake Brain PET.

    Science.gov (United States)

    Miranda, Alan; Staelens, Steven; Stroobants, Sigrid; Verhaeghe, Jeroen

    2017-07-01

    To avoid the confounding effects of anesthesia and immobilization stress in rat brain positron emission tomography (PET), motion tracking-based unrestrained awake rat brain imaging is being developed. In this paper, we propose a fast and accurate rat headmotion tracking method based on small PET point sources. PET point sources (3-4) attached to the rat's head are tracked in image space using 15-32-ms time frames. Our point source tracking (PST) method was validated using a manually moved microDerenzo phantom that was simultaneously tracked with an optical tracker (OT) for comparison. The PST method was further validated in three awake [ 18 F]FDG rat brain scans. Compared with the OT, the PST-based correction at the same frame rate (31.2 Hz) reduced the reconstructed FWHM by 0.39-0.66 mm for the different tested rod sizes of the microDerenzo phantom. The FWHM could be further reduced by another 0.07-0.13 mm when increasing the PST frame rate (66.7 Hz). Regional brain [ 18 F]FDG uptake in the motion corrected scan was strongly correlated ( ) with that of the anesthetized reference scan for all three cases ( ). The proposed PST method allowed excellent and reproducible motion correction in awake in vivo experiments. In addition, there is no need of specialized tracking equipment or additional calibrations to be performed, the point sources are practically imperceptible to the rat, and PST is ideally suitable for small bore scanners, where optical tracking might be challenging.

  5. Control system for Siam photon source

    CERN Document Server

    Apiwatwaja, R; Isoyama, G; Ishii, T; Pairsuwan, W

    2003-01-01

    A new computer control system has been developed for Siam photon source, which is the first synchrotron light source in Thailand, personal computers and PLC's have been employed which are connected together through Ethernet. Man Machine Interface Stations (MMIS) at the front end act as a graphical user interface within Windows environment. The monitoring and controlling of individual devices is handled through several pairs of digital control station and the device interface located in each part of the synchrotron complex. The installation of the control system has been completed. The commissioning test of the control system is underway and the reliability of the system is on the positive side. Details of commissioning tests as well as characteristics of this newly built control system for the Siam photon source are described in this report.

  6. Regularized inversion of controlled source and earthquake data

    International Nuclear Information System (INIS)

    Ramachandran, Kumar

    2012-01-01

    Estimation of the seismic velocity structure of the Earth's crust and upper mantle from travel-time data has advanced greatly in recent years. Forward modelling trial-and-error methods have been superseded by tomographic methods which allow more objective analysis of large two-dimensional and three-dimensional refraction and/or reflection data sets. The fundamental purpose of travel-time tomography is to determine the velocity structure of a medium by analysing the time it takes for a wave generated at a source point within the medium to arrive at a distribution of receiver points. Tomographic inversion of first-arrival travel-time data is a nonlinear problem since both the velocity of the medium and ray paths in the medium are unknown. The solution for such a problem is typically obtained by repeated application of linearized inversion. Regularization of the nonlinear problem reduces the ill posedness inherent in the tomographic inversion due to the under-determined nature of the problem and the inconsistencies in the observed data. This paper discusses the theory of regularized inversion for joint inversion of controlled source and earthquake data, and results from synthetic data testing and application to real data. The results obtained from tomographic inversion of synthetic data and real data from the northern Cascadia subduction zone show that the velocity model and hypocentral parameters can be efficiently estimated using this approach. (paper)

  7. Seasonal and spatial variation of diffuse (non-point) source zinc pollution in a historically metal mined river catchment, UK

    Energy Technology Data Exchange (ETDEWEB)

    Gozzard, E., E-mail: emgo@ceh.ac.uk [Hydrogeochemical Engineering Research and Outreach Group, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Mayes, W.M., E-mail: W.Mayes@hull.ac.uk [Hydrogeochemical Engineering Research and Outreach Group, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Potter, H.A.B., E-mail: hugh.potter@environment-agency.gov.uk [Environment Agency England and Wales, c/o Institute for Research on Environment and Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom); Jarvis, A.P., E-mail: a.p.jarvis@ncl.ac.uk [Hydrogeochemical Engineering Research and Outreach Group, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2011-10-15

    Quantifying diffuse sources of pollution is becoming increasingly important when characterising river catchments in entirety - a prerequisite for environmental management. This study examines both low and high flow events, as well as spatial variability, in order to assess point and diffuse components of zinc pollution within the River West Allen catchment, which lies within the northern England lead-zinc Orefield. Zinc levels in the river are elevated under all flow regimes, and are of environmental concern. Diffuse components are of little importance at low flow, with point source mine water discharges dominating instream zinc concentration and load. During higher river flows 90% of the instream zinc load is attributed to diffuse sources, where inputs from resuspension of metal-rich sediments, and groundwater influx are likely to be more dominant. Remediating point mine water discharges should significantly improve water quality at lower flows, but contribution from diffuse sources will continue to elevate zinc flux at higher flows. - Highlights: > Zinc concentrations breach EU quality thresholds under all river flow conditions. > Contributions from point sources dominate instream zinc dynamics in low flow. > Contributions from diffuse sources dominate instream zinc dynamics in high flow. > Important diffuse sources include river-bed sediment resuspension and groundwater influx. > Diffuse sources would still create significant instream pollution, even with point source treatment. - Diffuse zinc sources are an important source of instream contamination to mine-impacted rivers under varying flow conditions.

  8. The timing of control signals underlying fast point-to-point arm movements.

    Science.gov (United States)

    Ghafouri, M; Feldman, A G

    2001-04-01

    It is known that proprioceptive feedback induces muscle activation when the facilitation of appropriate motoneurons exceeds their threshold. In the suprathreshold range, the muscle-reflex system produces torques depending on the position and velocity of the joint segment(s) that the muscle spans. The static component of the torque-position relationship is referred to as the invariant characteristic (IC). According to the equilibrium-point (EP) hypothesis, control systems produce movements by changing the activation thresholds and thus shifting the IC of the appropriate muscles in joint space. This control process upsets the balance between muscle and external torques at the initial limb configuration and, to regain the balance, the limb is forced to establish a new configuration or, if the movement is prevented, a new level of static torques. Taken together, the joint angles and the muscle torques generated at an equilibrium configuration define a single variable called the EP. Thus by shifting the IC, control systems reset the EP. Muscle activation and movement emerge following the EP resetting because of the natural physical tendency of the system to reach equilibrium. Empirical and simulation studies support the notion that the control IC shifts and the resulting EP shifts underlying fast point-to-point arm movements are gradual rather than step-like. However, controversies exist about the duration of these shifts. Some studies suggest that the IC shifts cease with the movement offset. Other studies propose that the IC shifts end early in comparison to the movement duration (approximately, at peak velocity). The purpose of this study was to evaluate the duration of the IC shifts underlying fast point-to-point arm movements. Subjects made fast (hand peak velocity about 1.3 m/s) planar arm movements toward different targets while grasping a handle. Hand forces applied to the handle and shoulder/elbow torques were, respectively, measured from a force sensor placed

  9. ''Anomalous'' air showers from point sources: Mass limits and light curves

    International Nuclear Information System (INIS)

    Domokos, G.; Elliott, B.; Kovesi-Domokos, S.

    1993-01-01

    We describe a method to obtain upper limits on the mass of the primaries of air showers associated with point sources. One also obtains the UHE pulse shape of a pulsar if its period is observed in the signal. As an example, we analyze the data obtained during a recent burst of Hercules-X1

  10. The Potential for Electrofuels Production in Sweden Utilizing Fossil and Biogenic CO2 Point Sources

    International Nuclear Information System (INIS)

    Hansson, Julia; Hackl, Roman; Taljegard, Maria; Brynolf, Selma; Grahn, Maria

    2017-01-01

    This paper maps, categorizes, and quantifies all major point sources of carbon dioxide (CO 2 ) emissions from industrial and combustion processes in Sweden. The paper also estimates the Swedish technical potential for electrofuels (power-to-gas/fuels) based on carbon capture and utilization. With our bottom-up approach using European databases, we find that Sweden emits approximately 50 million metric tons of CO 2 per year from different types of point sources, with 65% (or about 32 million tons) from biogenic sources. The major sources are the pulp and paper industry (46%), heat and power production (23%), and waste treatment and incineration (8%). Most of the CO 2 is emitted at low concentrations (<15%) from sources in the southern part of Sweden where power demand generally exceeds in-region supply. The potentially recoverable emissions from all the included point sources amount to 45 million tons. If all the recoverable CO 2 were used to produce electrofuels, the yield would correspond to 2–3 times the current Swedish demand for transportation fuels. The electricity required would correspond to about 3 times the current Swedish electricity supply. The current relatively few emission sources with high concentrations of CO 2 (>90%, biofuel operations) would yield electrofuels corresponding to approximately 2% of the current demand for transportation fuels (corresponding to 1.5–2 TWh/year). In a 2030 scenario with large-scale biofuels operations based on lignocellulosic feedstocks, the potential for electrofuels production from high-concentration sources increases to 8–11 TWh/year. Finally, renewable electricity and production costs, rather than CO 2 supply, limit the potential for production of electrofuels in Sweden.

  11. Control of trafficking of radioactive sources/substances on European Community eastern border

    International Nuclear Information System (INIS)

    Lovjagina, Irina; Graveris, Visvaldis

    2008-01-01

    Full text: Taking into account Latvia geographical location, historical core stones (the dissolution of Soviet Union, join to European Community) and increasing of the international terrorism treats, control fissile and non-fissile radioactive material become one of high priorities. During past 2 years active work and practical exercise with representative from Ministry of Defense, Police, and Custom etc. on control of trafficking of such materials were performed and Operational Manual for Control on Radioactive Materials for Customs and Policy officers is issued. All land borders check points with Russian Federation and Byelorussian, all harbors and airports were equipped with a gamma/ neutrons or gamma control portals. To control unwanted material traffic within the country, as well as to ensure the recycled scrap metal is source-free use of monitoring portals and additional portable detectors in the past years strictly increased. Cases with alarm levels, when gamma dose rate exceeds more than 1.5 times the background level, are subject to reporting and analyzing by Radiation Safety Centre (RDC) experts (24 hours on duty). Consultative phone service for inhabitants is maintained; guidelines and working procedures within Authority and other Institutions involving were developed and implemented. As a result, in 2007 RDC has got 612 reports from the border. In 83% cases this was relevant to the trains, in 17%- to the trucks. Mostly enhanced activity was due to potassium compounds in fertilizers (85%), due to ceramics (4%), abrasives (2.5%), and refractory materials (3%). Controlling scrap metal there were revealed two sources in 2007 - one Sr-90 calibration source and other Cs-137 orphan source (origin unknown). The presence of radioactive sources in scrap in the past 3 years has been represented by Co-60, Cs-137 and Sr-90 sources, parts of statically electricity neutralizers, Ra-226. Several times NORM industries polluted materials were from scrap excluded

  12. Microbial profile and critical control points during processing of 'robo ...

    African Journals Online (AJOL)

    Microbial profile and critical control points during processing of 'robo' snack from ... the relevant critical control points especially in relation to raw materials and ... to the quality of the various raw ingredients used were the roasting using earthen

  13. The Atacama Cosmology Telescope: Development and preliminary results of point source observations

    Science.gov (United States)

    Fisher, Ryan P.

    2009-06-01

    The Atacama Cosmology Telescope (ACT) is a six meter diameter telescope designed to measure the millimeter sky with arcminute angular resolution. The instrument is currently conducting its third season of observations from Cerro Toco in the Chilean Andes. The primary science goal of the experiment is to expand our understanding of cosmology by mapping the temperature fluctuations of the Cosmic Microwave Background (CMB) at angular scales corresponding to multipoles up to [cursive l] ~ 10000. The primary receiver for current ACT observations is the Millimeter Bolometer Array Camera (MBAC). The instrument is specially designed to observe simultaneously at 148 GHz, 218 GHz and 277 GHz. To accomplish this, the camera has three separate detector arrays, each containing approximately 1000 detectors. After discussing the ACT experiment in detail, a discussion of the development and testing of the cold readout electronics for the MBAC is presented. Currently, the ACT collaboration is in the process of generating maps of the microwave sky using our first and second season observations. The analysis used to generate these maps requires careful data calibration to produce maps of the arcminute scale CMB temperature fluctuations. Tests and applications of several elements of the ACT calibrations are presented in the context of the second season observations. Scientific exploration has already begun on preliminary maps made using these calibrations. The final portion of this thesis is dedicated to discussing the point sources observed by the ACT. A discussion of the techniques used for point source detection and photometry is followed by a presentation of our current measurements of point source spectral indices.

  14. A 24 μm point source catalog of the galactic plane from Spitzer/MIPSGAL

    Energy Technology Data Exchange (ETDEWEB)

    Gutermuth, Robert A.; Heyer, Mark [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

    2015-02-01

    In this contribution, we describe the applied methods to construct a 24 μm based point source catalog derived from the image data of the MIPSGAL 24 μm Galactic Plane Survey and the corresponding data products. The high quality catalog product contains 933,818 sources, with a total of 1,353,228 in the full archive catalog. The source tables include positional and photometric information derived from the 24 μm images, source quality and confusion flags, and counterpart photometry from matched 2MASS, GLIMPSE, and WISE point sources. Completeness decay data cubes are constructed at 1′ angular resolution that describe the varying background levels over the MIPSGAL field and the ability to extract sources of a given magnitude from this background. The completeness decay cubes are included in the set of data products. We present the results of our efforts to verify the astrometric and photometric calibration of the catalog, and present several analyses of minor anomalies in these measurements to justify adopted mitigation strategies.

  15. Word Length Selection Method for Controller Implementation on FPGAs Using the VHDL-2008 Fixed-Point and Floating-Point Packages

    Directory of Open Access Journals (Sweden)

    Urriza I

    2010-01-01

    Full Text Available Abstract This paper presents a word length selection method for the implementation of digital controllers in both fixed-point and floating-point hardware on FPGAs. This method uses the new types defined in the VHDL-2008 fixed-point and floating-point packages. These packages allow customizing the word length of fixed and floating point representations and shorten the design cycle simplifying the design of arithmetic operations. The method performs bit-true simulations in order to determine the word length to represent the constant coefficients and the internal signals of the digital controller while maintaining the control system specifications. A mixed-signal simulation tool is used to simulate the closed loop system as a whole in order to analyze the impact of the quantization effects and loop delays on the control system performance. The method is applied to implement a digital controller for a switching power converter. The digital circuit is implemented on an FPGA, and the simulations are experimentally verified.

  16. LEAP: Looking beyond pixels with continuous-space EstimAtion of Point sources

    Science.gov (United States)

    Pan, Hanjie; Simeoni, Matthieu; Hurley, Paul; Blu, Thierry; Vetterli, Martin

    2017-12-01

    Context. Two main classes of imaging algorithms have emerged in radio interferometry: the CLEAN algorithm and its multiple variants, and compressed-sensing inspired methods. They are both discrete in nature, and estimate source locations and intensities on a regular grid. For the traditional CLEAN-based imaging pipeline, the resolution power of the tool is limited by the width of the synthesized beam, which is inversely proportional to the largest baseline. The finite rate of innovation (FRI) framework is a robust method to find the locations of point-sources in a continuum without grid imposition. The continuous formulation makes the FRI recovery performance only dependent on the number of measurements and the number of sources in the sky. FRI can theoretically find sources below the perceived tool resolution. To date, FRI had never been tested in the extreme conditions inherent to radio astronomy: weak signal / high noise, huge data sets, large numbers of sources. Aims: The aims were (i) to adapt FRI to radio astronomy, (ii) verify it can recover sources in radio astronomy conditions with more accurate positioning than CLEAN, and possibly resolve some sources that would otherwise be missed, (iii) show that sources can be found using less data than would otherwise be required to find them, and (iv) show that FRI does not lead to an augmented rate of false positives. Methods: We implemented a continuous domain sparse reconstruction algorithm in Python. The angular resolution performance of the new algorithm was assessed under simulation, and with visibility measurements from the LOFAR telescope. Existing catalogs were used to confirm the existence of sources. Results: We adapted the FRI framework to radio interferometry, and showed that it is possible to determine accurate off-grid point-source locations and their corresponding intensities. In addition, FRI-based sparse reconstruction required less integration time and smaller baselines to reach a comparable

  17. The estimation of the load of non-point source nitrogen and phosphorus based on observation experiments and export coefficient method in Three Gorges Reservoir Area

    Science.gov (United States)

    Tong, X. X.; Hu, B.; Xu, W. S.; Liu, J. G.; Zhang, P. C.

    2017-12-01

    In this paper, Three Gorges Reservoir Area (TGRA) was chosen to be the study area, the export coefficients of different land-use type were calculated through the observation experiments and literature consultation, and then the load of non-point source (NPS) nitrogen and phosphorus of different pollution sources such as farmland pollution sources, decentralized livestock and poultry breeding pollution sources and domestic pollution sources were estimated. The results show as follows: the pollution load of dry land is the main source of farmland pollution. The order of total nitrogen load of different pollution sources from high to low is livestock breeding pollution, domestic pollution, land use pollution, while the order of phosphorus load of different pollution sources from high to low is land use pollution, livestock breeding pollution, domestic pollution, Therefore, reasonable farmland management, effective control methods of dry land fertilization and sewage discharge of livestock breeding are the keys to the prevention and control of NPS nitrogen and phosphorus in TGRA.

  18. Exact analytical solution of time-independent neutron transport equation, and its applications to systems with a point source

    International Nuclear Information System (INIS)

    Mikata, Y.

    2014-01-01

    Highlights: • An exact solution for the one-speed neutron transport equation is obtained. • This solution as well as its derivation are believed to be new. • Neutron flux for a purely absorbing material with a point neutron source off the origin is obtained. • Spherically as well as cylindrically piecewise constant cross sections are studied. • Neutron flux expressions for a point neutron source off the origin are believed to be new. - Abstract: An exact analytical solution of the time-independent monoenergetic neutron transport equation is obtained in this paper. The solution is applied to systems with a point source. Systematic analysis of the solution of the time-independent neutron transport equation, and its applications represent the primary goal of this paper. To the best of the author’s knowledge, certain key results on the scalar neutron flux as well as their derivations are new. As an application of these results, a scalar neutron flux for a purely absorbing medium with a spherically piecewise constant cross section and an isotropic point neutron source off the origin as well as that for a cylindrically piecewise constant cross section with a point neutron source off the origin are obtained. Both of these results are believed to be new

  19. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik

    1994-01-01

    In alternating type activated sludge nutrient removal processes, the denitrification rate can be limited by the availability of readily-degradable carbon substrate. A control strategy is proposed by which an easily metabolizable COD source is added directly to that point in the process at which d...

  20. Point-Source Contributions to the Water Quality of an Urban Stream

    Science.gov (United States)

    Little, S. F. B.; Young, M.; Lowry, C.

    2014-12-01

    Scajaquada Creek, which runs through the heart of the city of Buffalo, is a prime example of the ways in which human intervention and local geomorphology can impact water quality and urban hydrology. Beginning in the 1920's, the Creek has been partially channelized and connected to Buffalo's combined sewer system (CSS). At Forest Lawn Cemetery, where this study takes place, Scajaquada Creek emerges from a 3.5-mile tunnel built to route stream flow under the city. Collocated with the tunnel outlet is a discharge point for Buffalo's CSS, combined sewer outlet (CSO) #53. It is at this point that runoff and sanitary sewage discharge regularly during rain events. Initially, this study endeavored to create a spatial and temporal picture for this portion of the Creek, monitoring such parameters as conductivity, dissolved oxygen, pH, temperature, and turbidity, in addition to measuring Escherichia coli (E. coli) concentrations. As expected, these factors responded directly to seasonality, local geomorphology, and distance from the point source (CSO #53), displaying a overall, linear response. However, the addition of nitrate and phosphate testing to the study revealed an entirely separate signal from that previously observed. Concentrations of these parameters did not respond to location in the same manner as E. coli. Instead of decreasing with distance from the CSO, a distinct periodicity was observed, correlating with a series of outflow pipes lining the stream banks. It is hypothesized that nitrate and phosphate occurring in this stretch of Scajaquada Creek originate not from the CSO, but from fertilizers used to maintain the lawns within the subwatershed. These results provide evidence of the complexity related to water quality issues in urban streams as a result of point- and nonpoint-source hydrologic inputs.

  1. Controlling superconductivity by tunable quantum critical points.

    Science.gov (United States)

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-03-04

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5.

  2. Mercury exposure in terrestrial birds far downstream of an historical point source

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Allyson K., E-mail: allyson.jackson@briloon.org [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Evers, David C.; Folsom, Sarah B. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Condon, Anne M. [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Diener, John; Goodrick, Lizzie F. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); McGann, Andrew J. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Schmerfeld, John [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Cristol, Daniel A. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States)

    2011-12-15

    Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: > We report blood mercury levels for terrestrial songbirds downstream of contamination. > Blood mercury levels remain elevated above reference for at least 137 km downstream. > Trends vary based on foraging guild and migration strategy. > Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

  3. Model predictive control for Z-source power converter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P.C.; Blaabjerg, Frede

    2011-01-01

    This paper presents Model Predictive Control (MPC) of impedance-source (commonly known as Z-source) power converter. Output voltage control and current control for Z-source inverter are analyzed and simulated. With MPC's ability of multi- system variables regulation, load current and voltage...

  4. X-Ray and Near-Infrared Spectroscopy of Dim X-Ray Point Sources Constituting the Galactic Ridge X-Ray Emission

    Directory of Open Access Journals (Sweden)

    Kumiko Morihana

    2014-12-01

    Full Text Available We present the results of X-ray and Near-Infrared observations of the Galactic Ridge X-ray Emission (GRXE. We extracted 2,002 X-ray point sources in the Chandra Bulge Field (l =0°.113, b = 1°.424 down to ~10-14.8 ergscm-2s-1 in 2-8 keV band with the longest observation (900 ks of the GRXE. Based on X-ray brightness and hardness, we classied the X-ray point sources into three groups: A (hard, B (soft and broad spectrum, and C (soft and peaked spectrum. In order to know populations of the X-ray point sources, we carried out NIR imaging and spectroscopy observation. We identied 11% of X-ray point sources with NIR and extracted NIR spectra for some of them. Based on X-ray and NIR properties, we concluded that non-thermal sources in the group A are mostly active galactic nuclei and the thermal sources are mostly white dwarf binaries such as cataclysmic variables (CVs and Pre-CVs. We concluded that the group B and C sources are X-ray active stars in flare and quiescence, respectively.

  5. Isosbestic points in the quality control oF spectrophotometers

    International Nuclear Information System (INIS)

    Oliveira, E.M. de.

    1987-01-01

    The methodology and results of quality control of spectrophotometers are reported and the calibrating of the monochromator by isosbestic points is presented. Four colorimetric indicators are used. The absorption curves (in acid and alkaline media) and mathematic determination of the common junction point are used for indicated the isosbetic points. (M.A.C.) [pt

  6. Non point source pollution modelling in the watershed managed by Integrated Conctructed Wetlands: A GIS approach.

    OpenAIRE

    Vyavahare, Nilesh

    2008-01-01

    The non-point source pollution has been recognised as main cause of eutrophication in Ireland (EPA Ireland, 2001). Integrated Constructed Wetland (ICW) is a management practice adopted in Annestown stream watershed, located in the south county of Waterford in Ireland, used to cleanse farmyard runoff. Present study forms the annual pollution budget for the Annestown stream watershed. The amount of pollution from non-point sources flowing into the stream was simulated by using GIS techniques; u...

  7. Triana Safehold: A New Gyroless, Sun-Pointing Attitude Controller

    Science.gov (United States)

    Chen, J.; Morgenstern, Wendy; Garrick, Joseph

    2001-01-01

    Triana is a single-string spacecraft to be placed in a halo orbit about the sun-earth Ll Lagrangian point. The Attitude Control Subsystem (ACS) hardware includes four reaction wheels, ten thrusters, six coarse sun sensors, a star tracker, and a three-axis Inertial Measuring Unit (IMU). The ACS Safehold design features a gyroless sun-pointing control scheme using only sun sensors and wheels. With this minimum hardware approach, Safehold increases mission reliability in the event of a gyroscope anomaly. In place of the gyroscope rate measurements, Triana Safehold uses wheel tachometers to help provide a scaled estimation of the spacecraft body rate about the sun vector. Since Triana nominally performs momentum management every three months, its accumulated system momentum can reach a significant fraction of the wheel capacity. It is therefore a requirement for Safehold to maintain a sun-pointing attitude even when the spacecraft system momentum is reasonably large. The tachometer sun-line rate estimation enables the controller to bring the spacecraft close to its desired sun-pointing attitude even with reasonably high system momentum and wheel drags. This paper presents the design rationale behind this gyroless controller, stability analysis, and some time-domain simulation results showing performances with various initial conditions. Finally, suggestions for future improvements are briefly discussed.

  8. Engineering to Control Noise, Loading, and Optimal Operating Points

    International Nuclear Information System (INIS)

    Mitchell R. Swartz

    2000-01-01

    Successful engineering of low-energy nuclear systems requires control of noise, loading, and optimum operating point (OOP) manifolds. The latter result from the biphasic system response of low-energy nuclear reaction (LENR)/cold fusion systems, and their ash production rate, to input electrical power. Knowledge of the optimal operating point manifold can improve the reproducibility and efficacy of these systems in several ways. Improved control of noise, loading, and peak production rates is available through the study, and use, of OOP manifolds. Engineering of systems toward the OOP-manifold drive-point peak may, with inclusion of geometric factors, permit more accurate uniform determinations of the calibrated activity of these materials/systems

  9. A Combined Control Chart for Identifying Out–Of–Control Points in Multivariate Processes

    Directory of Open Access Journals (Sweden)

    Marroquín–Prado E.

    2010-10-01

    Full Text Available The Hotelling's T2 control chart is widely used to identify out–of–control signals in multivariate processes. However, this chart is not sensitive to small shifts in the process mean vec tor. In this work we propose a control chart to identify out–of–control signals. The proposed chart is a combination of Hotelling's T2 chart, M chart proposed by Hayter et al. (1994 and a new chart based on Principal Components. The combination of these charts identifies any type and size of change in the process mean vector. Us ing simulation and the Average Run Length (ARL, the performance of the proposed control chart is evaluated. The ARL means the average points within control before an out–of–control point is detected, The results of the simulation show that the proposed chart is more sensitive that each one of the three charts individually

  10. TIG source control system when welding point-by-point the elements of the collector

    International Nuclear Information System (INIS)

    Bica, I.

    1997-01-01

    The paper presents a control system designed to equip the mechanized welding installations of the collector winding. The logical function of the technological process is determined the synthesis of the electric current is made, too. The logical circuit is made in the TTL technique. It presents reliability and safety in service. (Author) 3 refs

  11. 21 CFR 120.8 - Hazard Analysis and Critical Control Point (HACCP) plan.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Hazard Analysis and Critical Control Point (HACCP... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS General Provisions § 120.8 Hazard Analysis and Critical Control Point (HACCP) plan. (a) HACCP plan. Each...

  12. A proton point source produced by laser interaction with cone-top-end target

    International Nuclear Information System (INIS)

    Yu, Jinqing; Jin, Xiaolin; Zhou, Weimin; Zhao, Zongqing; Yan, Yonghong; Li, Bin; Hong, Wei; Gu, Yuqiu

    2012-01-01

    In this paper, we propose a proton point source by the interaction of laser and cone-top-end target and investigate it by two-dimensional particle-in-cell (2D-PIC) simulations as the proton point sources are well known for higher spatial resolution of proton radiography. Our results show that the relativistic electrons are guided to the rear of the cone-top-end target by the electrostatic charge-separation field and self-generated magnetic field along the profile of the target. As a result, the peak magnitude of sheath field at the rear surface of cone-top-end target is higher compared to common cone target. We test this scheme by 2D-PIC simulation and find the result has a diameter of 0.79λ 0 , an average energy of 9.1 MeV and energy spread less than 35%.

  13. Identifying and characterizing major emission point sources as a basis for geospatial distribution of mercury emissions inventories

    Science.gov (United States)

    Steenhuisen, Frits; Wilson, Simon J.

    2015-07-01

    Mercury is a global pollutant that poses threats to ecosystem and human health. Due to its global transport, mercury contamination is found in regions of the Earth that are remote from major emissions areas, including the Polar regions. Global anthropogenic emission inventories identify important sectors and industries responsible for emissions at a national level; however, to be useful for air transport modelling, more precise information on the locations of emission is required. This paper describes the methodology applied, and the results of work that was conducted to assign anthropogenic mercury emissions to point sources as part of geospatial mapping of the 2010 global anthropogenic mercury emissions inventory prepared by AMAP/UNEP. Major point-source emission sectors addressed in this work account for about 850 tonnes of the emissions included in the 2010 inventory. This work allocated more than 90% of these emissions to some 4600 identified point source locations, including significantly more point source locations in Africa, Asia, Australia and South America than had been identified during previous work to geospatially-distribute the 2005 global inventory. The results demonstrate the utility and the limitations of using existing, mainly public domain resources to accomplish this work. Assumptions necessary to make use of selected online resources are discussed, as are artefacts that can arise when these assumptions are applied to assign (national-sector) emissions estimates to point sources in various countries and regions. Notwithstanding the limitations of the available information, the value of this procedure over alternative methods commonly used to geo-spatially distribute emissions, such as use of 'proxy' datasets to represent emissions patterns, is illustrated. Improvements in information that would facilitate greater use of these methods in future work to assign emissions to point-sources are discussed. These include improvements to both national

  14. The 100 strongest radio point sources in the field of the Large Magellanic Cloud at 1.4 GHz

    Directory of Open Access Journals (Sweden)

    Payne J.L.

    2009-01-01

    Full Text Available We present the 100 strongest 1.4 GHz point sources from a new mosaic image in the direction of the Large Magellanic Cloud (LMC. The observations making up the mosaic were made using Australia Telescope Compact Array (ATCA over a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 1000 at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact H ii regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index (α of -0.53 and present a 1.4 GHz image showing source location in the direction of the LMC.

  15. The 100 Strongest Radio Point Sources in the Field of the Large Magellanic Cloud at 1.4 GHz

    Directory of Open Access Journals (Sweden)

    Payne, J. L.

    2009-06-01

    Full Text Available We present the 100 strongest 1.4~GHz point sources from a new mosaicimage in the direction of the Large Magellanic Cloud (LMC. The observationsmaking up the mosaic were made using Australia Telescope Compact Array (ATCAover a ten year period and were combined with Parkes single dish data at 1.4 GHz to complete the image for short spacing. An initial list of co-identifications within 10arcsec at 0.843, 4.8 and 8.6 GHz consisted of 2682 sources. Elimination of extended objects and artifact noise allowed the creation of a refined list containing 1988 point sources. Most of these are presumed to be background objects seen through the LMC; a small portion may represent compact HII regions, young SNRs and radio planetary nebulae. For the 1988 point sources we find a preliminary average spectral index ($alpha$ of -0.53 and present a 1.4 GHz image showing source locationin the direction of the LMC.

  16. CRITICAL CONTROL POINTS ON THE TECHNOLOGICAL FLOW OF PANIFICATION

    Directory of Open Access Journals (Sweden)

    Gigel PARASCHIV

    2013-05-01

    Full Text Available Bread and panification products are intended for direct human consumption and underlying nutritional pyramid, it can affect the consumers health in case of biological, chemical or physical contamination, immediate or delayed, by noxious accumulation in the human organism. Only by rigorous compliance of the production rules throughout the technological process can ensure the quality and food safety of these products. If the risk can be prevented, eliminated or reduce to an acceptable level, as a result of a control actions made at that stage, it is considered a Critical Control Point (CCP. There can be checkpoints where it can exert a control action. Thus, the checkpoint is represented by any stage in which the risk factors, biological, chemical or physical, can be controlled in order to prevent, disrupt or reduce them to an acceptable level. This paper is referring to the control points on the technological flow of the bread fabrication, in all phases of this technological flow, laying stress on that points (or phases which can affect security and food safety, through the influence of parameters of any kind on the quality of finished products.

  17. Strategies for lidar characterization of particulates from point and area sources

    Science.gov (United States)

    Wojcik, Michael D.; Moore, Kori D.; Martin, Randal S.; Hatfield, Jerry

    2010-10-01

    Use of ground based remote sensing technologies such as scanning lidar systems (light detection and ranging) has gained traction in characterizing ambient aerosols due to some key advantages such as wide area of regard (10 km2), fast response time, high spatial resolution (University, in conjunction with the USDA-ARS, has developed a three-wavelength scanning lidar system called Aglite that has been successfully deployed to characterize particle motion, concentration, and size distribution at both point and diffuse area sources in agricultural and industrial settings. A suite of massbased and size distribution point sensors are used to locally calibrate the lidar. Generating meaningful particle size distribution, mass concentration, and emission rate results based on lidar data is dependent on strategic onsite deployment of these point sensors with successful local meteorological measurements. Deployment strategies learned from field use of this entire measurement system over five years include the characterization of local meteorology and its predictability prior to deployment, the placement of point sensors to prevent contamination and overloading, the positioning of the lidar and beam plane to avoid hard target interferences, and the usefulness of photographic and written observational data.

  18. The IAEA and Control of Radioactive Sources

    International Nuclear Information System (INIS)

    Dodd, B.

    2004-01-01

    The presentation discusses the authoritative functions and the departments of the IAEA, especially the Department of Nuclear Safety and Security and its Safety and Security of Radiation Sources Unit. IAEA safety series and IAEA safety standards series inform about international standards, provide underlying principles, specify obligations and responsibilities and give recommendations to support requirements. Other IAEA relevant publications comprise safety reports, technical documents (TECDOCs), conferences and symposium papers series and accident reports. Impacts of loss of source control is discussed, definitions of orphan sources and vulnerable sources is given. Accidents with orphan sources, radiological accidents statistic (1944-2000) and its consequences are discussed. These incidents lead to development of the IAEA guidance. The IAEA's action plan for the safety of radiation sources and the security of radioactive material was approved by the IAEA Board of Governors and the General Conference in September 1999. This led to the 'Categorization of Radiation Sources' and the 'Code of Conduct on the Safety and Security of Radioactive Sources'. After 0911 the IAEA developed a nuclear security plan of activities including physical protection of nuclear material and nuclear facilities, detection of malicious activities involving nuclear and other radioactive materials, state systems for nuclear material accountancy and control, security of radioactive material other than nuclear material, assessment of safety and security related vulnerability of nuclear facilities, response to malicious acts, or threats thereof, adherence to and implementation of international agreements, guidelines and recommendations and nuclear security co-ordination and information management. The remediation of past problems comprised collection and disposal of known disused sources, securing vulnerable sources and especially high-risk sources (Tripartite initiative), searching for

  19. Validation of novel calibration scheme with traceable point-like (22)Na sources on six types of PET scanners.

    Science.gov (United States)

    Hasegawa, Tomoyuki; Oda, Keiichi; Wada, Yasuhiro; Sasaki, Toshiaki; Sato, Yasushi; Yamada, Takahiro; Matsumoto, Mikio; Murayama, Hideo; Kikuchi, Kei; Miyatake, Hiroki; Abe, Yutaka; Miwa, Kenta; Akimoto, Kenta; Wagatsuma, Kei

    2013-05-01

    To improve the reliability and convenience of the calibration procedure of positron emission tomography (PET) scanners, we have been developing a novel calibration path based on traceable point-like sources. When using (22)Na sources, special care should be taken to avoid the effects of 1.275-MeV γ rays accompanying β (+) decays. The purpose of this study is to validate this new calibration scheme with traceable point-like (22)Na sources on various types of PET scanners. Traceable point-like (22)Na sources with a spherical absorber design that assures uniform angular distribution of the emitted annihilation photons were used. The tested PET scanners included a clinical whole-body PET scanner, four types of clinical PET/CT scanners from different manufacturers, and a small-animal PET scanner. The region of interest (ROI) diameter dependence of ROI values was represented with a fitting function, which was assumed to consist of a recovery part due to spatial resolution and a quadratic background part originating from the scattered γ rays. The observed ROI radius dependence was well represented with the assumed fitting function (R (2) > 0.994). The calibration factors determined using the point-like sources were consistent with those by the standard cross-calibration method within an uncertainty of ±4 %, which was reasonable considering the uncertainty in the standard cross-calibration method. This novel calibration scheme based on the use of traceable (22)Na point-like sources was successfully validated for six types of commercial PET scanners.

  20. Calibrate the aerial surveying instrument by the limited surface source and the single point source that replace the unlimited surface source

    International Nuclear Information System (INIS)

    Lu Cunheng

    1999-01-01

    It is described that the calculating formula and surveying result is found on the basis of the stacking principle of gamma ray and the feature of hexagonal surface source when the limited surface source replaces the unlimited surface source to calibrate the aerial survey instrument on the ground, and that it is found in the light of the exchanged principle of the gamma ray when the single point source replaces the unlimited surface source to calibrate aerial surveying instrument in the air. Meanwhile through the theoretical analysis, the receiving rate of the crystal bottom and side surfaces is calculated when aerial surveying instrument receives gamma ray. The mathematical expression of the gamma ray decaying following height according to the Jinge function regularity is got. According to this regularity, the absorbing coefficient that air absorbs the gamma ray and the detective efficiency coefficient of the crystal is calculated based on the ground and air measuring value of the bottom surface receiving count rate (derived from total receiving count rate of the bottom and side surface). Finally, according to the measuring value, it is proved that imitating the change of total receiving gamma ray exposure rate of the bottom and side surfaces with this regularity in a certain high area is feasible

  1. The Potential for Electrofuels Production in Sweden Utilizing Fossil and Biogenic CO{sub 2} Point Sources

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, Julia, E-mail: julia.hansson@ivl.se [Climate and Sustainable Cities, IVL Swedish Environmental Research Institute, Stockholm (Sweden); Division of Physical Resource Theory, Department of Energy and Environment, Chalmers University of Technology, Göteborg (Sweden); Hackl, Roman [Climate and Sustainable Cities, IVL Swedish Environmental Research Institute, Stockholm (Sweden); Taljegard, Maria [Division of Energy Technology, Department of Energy and Environment, Chalmers University of Technology, Göteborg (Sweden); Brynolf, Selma; Grahn, Maria [Division of Physical Resource Theory, Department of Energy and Environment, Chalmers University of Technology, Göteborg (Sweden)

    2017-03-13

    This paper maps, categorizes, and quantifies all major point sources of carbon dioxide (CO{sub 2}) emissions from industrial and combustion processes in Sweden. The paper also estimates the Swedish technical potential for electrofuels (power-to-gas/fuels) based on carbon capture and utilization. With our bottom-up approach using European databases, we find that Sweden emits approximately 50 million metric tons of CO{sub 2} per year from different types of point sources, with 65% (or about 32 million tons) from biogenic sources. The major sources are the pulp and paper industry (46%), heat and power production (23%), and waste treatment and incineration (8%). Most of the CO{sub 2} is emitted at low concentrations (<15%) from sources in the southern part of Sweden where power demand generally exceeds in-region supply. The potentially recoverable emissions from all the included point sources amount to 45 million tons. If all the recoverable CO{sub 2} were used to produce electrofuels, the yield would correspond to 2–3 times the current Swedish demand for transportation fuels. The electricity required would correspond to about 3 times the current Swedish electricity supply. The current relatively few emission sources with high concentrations of CO{sub 2} (>90%, biofuel operations) would yield electrofuels corresponding to approximately 2% of the current demand for transportation fuels (corresponding to 1.5–2 TWh/year). In a 2030 scenario with large-scale biofuels operations based on lignocellulosic feedstocks, the potential for electrofuels production from high-concentration sources increases to 8–11 TWh/year. Finally, renewable electricity and production costs, rather than CO{sub 2} supply, limit the potential for production of electrofuels in Sweden.

  2. Advanced Light Source control system

    International Nuclear Information System (INIS)

    Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.

    1989-03-01

    The Advanced Light Source (ALS) is a third generation 1--2 GeV synchrotron radiation source designed to provide ports for 60 beamlines. It uses a 50 MeV electron linac and 1.5 GeV, 1 Hz, booster synchrotron for injection into a 1--2 GeV storage ring. Interesting control problems are created because of the need for dynamic closed beam orbit control to eliminate interaction between the ring tuning requirements and to minimize orbit shifts due to ground vibrations. The extremely signal sensitive nature of the experiments requires special attention to the sources of electrical noise. These requirements have led to a control system design which emphasizes connectivity at the accelerator equipment end and a large I/O bandwidth for closed loop system response. Not overlooked are user friendliness, operator response time, modeling, and expert system provisions. Portable consoles are used for local operation of machine equipment. Our solution is a massively parallel system with >120 Mbits/sec I/O bandwidth and >1500 Mips computing power. At the equipment level connections are made using over 600 powerful Intelligent Local Controllers (ILC-s) mounted in 3U size Eurocard slots using fiber-optic cables between rack locations. In the control room, personal computers control and display all machine variables at a 10 Hz rate including the scope signals which are collected though the control system. Commercially available software and industry standards are used extensively. Particular attention is paid to reliability, maintainability and upgradeability. 10 refs., 11 figs

  3. Maximum power point tracking

    International Nuclear Information System (INIS)

    Enslin, J.H.R.

    1990-01-01

    A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

  4. Mercury exposure in terrestrial birds far downstream of an historical point source

    International Nuclear Information System (INIS)

    Jackson, Allyson K.; Evers, David C.; Folsom, Sarah B.; Condon, Anne M.; Diener, John; Goodrick, Lizzie F.; McGann, Andrew J.; Schmerfeld, John; Cristol, Daniel A.

    2011-01-01

    Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: → We report blood mercury levels for terrestrial songbirds downstream of contamination. → Blood mercury levels remain elevated above reference for at least 137 km downstream. → Trends vary based on foraging guild and migration strategy. → Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

  5. Fuzzy Controller Design Using FPGA for Photovoltaic Maximum Power Point Tracking

    OpenAIRE

    Basil M Hamed; Mohammed S. El-Moghany

    2012-01-01

    The cell has optimum operating point to be able to get maximum power. To obtain Maximum Power from photovoltaic array, photovoltaic power system usually requires Maximum Power Point Tracking (MPPT) controller. This paper provides a small power photovoltaic control system based on fuzzy control with FPGA technology design and implementation for MPPT. The system composed of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA for controlling on/off time of MOSF...

  6. Stabilizing Planar Inverted Pendulum System Based on Fuzzy Nine-point Controller

    OpenAIRE

    Qi Qian; Liu Feng; Tang Yong-chuan; Yang Yang

    2013-01-01

    In order to stabilize planar inverted pendulum, after analyzing the physical characteristics of the planar inverted pendulum system, a pendulum nine-point controller and a car nine-point controller for X-axis and Y-axis were designed respectively. Then a fuzzy coordinator was designed using the fuzzy control theory based on the priority of those two controllers, and the priority level of the pendulum is higher than the car. Thus, the control tasks of each controller in each axis were harmoniz...

  7. Crowd-sourced BMS point matching and metadata maintenance with Babel

    DEFF Research Database (Denmark)

    Fürst, Jonathan; Chen, Kaifei; Katz, Randy H.

    2016-01-01

    Cyber-physical applications, deployed on top of Building Management Systems (BMS), promise energy saving and comfort improvement in non-residential buildings. Such applications are so far mainly deployed as research prototypes. The main roadblock to widespread adoption is the low quality of BMS...... systems. Such applications access sensors and actuators through BMS metadata in form of point labels. The naming of labels is however often inconsistent and incomplete. To tackle this problem, we introduce Babel, a crowd-sourced approach to the creation and maintenance of BMS metadata. In our system...

  8. Fuzzy Logic Based Set-Point Weighting Controller Tuning for an Internal Model Control Based PID Controller

    Directory of Open Access Journals (Sweden)

    Maruthai Suresh

    2009-10-01

    Full Text Available Controller tuning is the process of adjusting the parameters of the selected controller to achieve optimum response for the controlled process. For many of the control problems, a satisfactory performance is obtained by using PID controllers. One of the main problems with mathematical models of physical systems is that the parameters used in the models cannot be determined with absolute accuracy. The values of the parameters may change with time or various effects. In these cases, conventional controller tuning methods suffer when trying a lot to produce optimum response. In order to overcome these difficulties a fuzzy logic based Set- Point weighting controller tuning method is proposed. The effectiveness of the proposed scheme is analyzed through computer simulation using SIMULINK software and the results are presented. The fuzzy logic based simulation results are compared with Cohen-Coon (CC, Ziegler- Nichols (ZN, Ziegler – Nichols with Set- Point weighting (ZN-SPW, Internal Model Control (IMC and Internal model based PID controller responses (IMC-PID. The effects of process modeling errors and the importance of controller tuning have been brought out using the proposed control scheme.

  9. Effects of pointing compared with naming and observing during encoding on item and source memory in young and older adults.

    Science.gov (United States)

    Ouwehand, Kim; van Gog, Tamara; Paas, Fred

    2016-10-01

    Research showed that source memory functioning declines with ageing. Evidence suggests that encoding visual stimuli with manual pointing in addition to visual observation can have a positive effect on spatial memory compared with visual observation only. The present study investigated whether pointing at picture locations during encoding would lead to better spatial source memory than naming (Experiment 1) and visual observation only (Experiment 2) in young and older adults. Experiment 3 investigated whether response modality during the test phase would influence spatial source memory performance. Experiments 1 and 2 supported the hypothesis that pointing during encoding led to better source memory for picture locations than naming or observation only. Young adults outperformed older adults on the source memory but not the item memory task in both Experiments 1 and 2. In Experiments 1 and 2, participants manually responded in the test phase. Experiment 3 showed that if participants had to verbally respond in the test phase, the positive effect of pointing compared with naming during encoding disappeared. The results suggest that pointing at picture locations during encoding can enhance spatial source memory in both young and older adults, but only if the response modality is congruent in the test phase.

  10. A Comparative Analysis of Vibrio cholerae Contamination in Point-of-Drinking and Source Water in a Low-Income Urban Community, Bangladesh.

    Science.gov (United States)

    Ferdous, Jannatul; Sultana, Rebeca; Rashid, Ridwan B; Tasnimuzzaman, Md; Nordland, Andreas; Begum, Anowara; Jensen, Peter K M

    2018-01-01

    Bangladesh is a cholera endemic country with a population at high risk of cholera. Toxigenic and non-toxigenic Vibrio cholerae ( V. cholerae ) can cause cholera and cholera-like diarrheal illness and outbreaks. Drinking water is one of the primary routes of cholera transmission in Bangladesh. The aim of this study was to conduct a comparative assessment of the presence of V. cholerae between point-of-drinking water and source water, and to investigate the variability of virulence profile using molecular methods of a densely populated low-income settlement of Dhaka, Bangladesh. Water samples were collected and tested for V. cholerae from "point-of-drinking" and "source" in 477 study households in routine visits at 6 week intervals over a period of 14 months. We studied the virulence profiles of V. cholerae positive water samples using 22 different virulence gene markers present in toxigenic O1/O139 and non-O1/O139 V. cholerae using polymerase chain reaction (PCR). A total of 1,463 water samples were collected, with 1,082 samples from point-of-drinking water in 388 households and 381 samples from 66 water sources. V. cholerae was detected in 10% of point-of-drinking water samples and in 9% of source water samples. Twenty-three percent of households and 38% of the sources were positive for V. cholerae in at least one visit. Samples collected from point-of-drinking and linked sources in a 7 day interval showed significantly higher odds ( P source [OR = 17.24 (95% CI = 7.14-42.89)] water. Based on the 7 day interval data, 53% (17/32) of source water samples were negative for V. cholerae while linked point-of-drinking water samples were positive. There were significantly higher odds ( p source water samples than in point-of-drinking water samples. Contamination of water at the point-of-drinking is less likely to depend on the contamination at the water source. Hygiene education interventions and programs should focus and emphasize on water at the point

  11. Power-Law Template for IR Point Source Clustering

    Science.gov (United States)

    Addison, Graeme E.; Dunkley, Joanna; Hajian, Amir; Viero, Marco; Bond, J. Richard; Das, Sudeep; Devlin, Mark; Halpern, Mark; Hincks, Adam; Hlozek, Renee; hide

    2011-01-01

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217,353,545 and 857 GHz, over angular scales 100 clustered power over the range of angular scales and frequencies considered is well fit by a simple power law of the form C_l\\propto I(sup -n) with n = 1.25 +/- 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, nu(sup beta) B(nu,T_eff), with a single emissivity index beta = 2.20 +/- 0.07 and effective temperature T_eff= 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be alpha_150-220 = 3.68 +/- 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in Cosmic Microwave Background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  12. Power-Law Template for Infrared Point-Source Clustering

    Science.gov (United States)

    Addison, Graeme E; Dunkley, Joanna; Hajian, Amir; Viero, Marco; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Halpern, Mark; Hincks, Adam D; Hlozek, Renee; hide

    2012-01-01

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217, 353, 545, and 857 GHz, over angular scales 100 approx clustered power over the range of angular scales and frequencies considered is well fitted by a simple power law of the form C(sup clust)(sub l) varies as l (sub -n) with n = 1.25 +/- 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, ?(sup Beta)B(?, T(sub eff) ), with a single emissivity index Beta = 2.20 +/- 0.07 and effective temperature T(sub eff) = 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be alpha(sub 150-220) = 3.68 +/- 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in cosmic microwave background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  13. PointCom: semi-autonomous UGV control with intuitive interface

    Science.gov (United States)

    Rohde, Mitchell M.; Perlin, Victor E.; Iagnemma, Karl D.; Lupa, Robert M.; Rohde, Steven M.; Overholt, James; Fiorani, Graham

    2008-04-01

    Unmanned ground vehicles (UGVs) will play an important role in the nation's next-generation ground force. Advances in sensing, control, and computing have enabled a new generation of technologies that bridge the gap between manual UGV teleoperation and full autonomy. In this paper, we present current research on a unique command and control system for UGVs named PointCom (Point-and-Go Command). PointCom is a semi-autonomous command system for one or multiple UGVs. The system, when complete, will be easy to operate and will enable significant reduction in operator workload by utilizing an intuitive image-based control framework for UGV navigation and allowing a single operator to command multiple UGVs. The project leverages new image processing algorithms for monocular visual servoing and odometry to yield a unique, high-performance fused navigation system. Human Computer Interface (HCI) techniques from the entertainment software industry are being used to develop video-game style interfaces that require little training and build upon the navigation capabilities. By combining an advanced navigation system with an intuitive interface, a semi-autonomous control and navigation system is being created that is robust, user friendly, and less burdensome than many current generation systems. mand).

  14. EPICS application source/release control

    International Nuclear Information System (INIS)

    Zieman, B.; Anderson, J.; Kraimer, M.

    1995-01-01

    This manual describes a set of Application Source/Release Control tools (appSR) that can be used to develop software for EPICS based control systems. The Application Source/Release Control System (appSR) has been unbundled from base EPICS and is now available as an EPICS extension. Due to this unbundling, two new directories must be added to a user's path (see section ''Environment'' on page 3 for more information) and a new command getapp must be issued after the getrel command to get a specific version of appSR (see section ''Creating The Initial Application System Area'' on page 7 for more information). It is now required that GNU make version 3.71 or later be used for makes instead of SUN make. Users should now type gmake instead of make

  15. Automatic control of a negative ion source

    International Nuclear Information System (INIS)

    Saadatmand, K.; Sredniawski, J.; Solensten, L.

    1989-01-01

    A CAMAC based control architecture is devised for a Berkeley-type H - volume ion source. The architecture employs three 80386 PCs. One PC is dedicated to control and monitoring of source operation. The other PC functions with digitizers to provide data acquisition of waveforms. The third PC is used for off-line analysis. Initially, operation of the source was put under remote computer control (supervisory). This was followed by development of an automated startup procedure. Finally, a study of the physics of operation is now underway to establish a data base from which automatic beam optimization can be derived. (orig.)

  16. Automatic control of a negative ion source

    Science.gov (United States)

    Saadatmand, K.; Sredniawski, J.; Solensten, L.

    1989-04-01

    A CAMAC based control architecture is devised for a Berkeley-type H - volume ion source [1]. The architecture employs three 80386 TM PCs. One PC is dedicated to control and monitoring of source operation. The other PC functions with digitizers to provide data acquisition of waveforms. The third PC is used for off-line analysis. Initially, operation of the source was put under remote computer control (supervisory). This was followed by development of an automated startup procedure. Finally, a study of the physics of operation is now underway to establish a data base from which automatic beam optimization can be derived.

  17. Automatic control of a negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Saadatmand, K.; Sredniawski, J.; Solensten, L. (Grumman Corp., Long Island, NY (USA))

    1989-04-01

    A CAMAC based control architecture is devised for a Berkeley-type H/sup -/ volume ion source. The architecture employs three 80386 PCs. One PC is dedicated to control and monitoring of source operation. The other PC functions with digitizers to provide data acquisition of waveforms. The third PC is used for off-line analysis. Initially, operation of the source was put under remote computer control (supervisory). This was followed by development of an automated startup procedure. Finally, a study of the physics of operation is now underway to establish a data base from which automatic beam optimization can be derived. (orig.).

  18. System implementation of hazard analysis and critical control points (HACCP) in a nitrogen production plant

    International Nuclear Information System (INIS)

    Barrantes Salazar, Alexandra

    2014-01-01

    System of hazard analysis and critical control points are deployed in a production plant of liquid nitrogen. The fact that the nitrogen has become a complement to food packaging to increase shelf life, or provide a surface that protect it from manipulation, has been the main objective. Analysis of critical control points for the nitrogen production plant has been the adapted methodology. The knowledge of both the standard and the production process, as well as the on site verification process, have been necessary. In addition, all materials and/or processing units that are found in contact with the raw material or the product under study were evaluated. Such a way that the intrinsic risks of each were detected, from the physical, chemical and biological points of view according to the origin or pollution source. For each found risk was evaluated the probability of occurrence according to the frequency and gravity of it, with these variables determined was achieved the definition of the type of risk detected. In the cases that was presented a greater risk or critical, these were subjected decision tree; with which is concluded the non determination of critical control points. However, for each one of them were established the maximum permitted limits. To generate each of the results it has literature or scientific reference of reliable provenance, where is indicated properly the support of the evaluated matter. In a general way, the material matrix and the process matrix are found without critical control points; so that the project is concluded in the analysis, and it has to generate without the monitoring system and verification. To increase this project is suggested in order to cover the packaging system of gaseous nitrogen, due to it was delimited to liquid nitrogen. Furthermore, the liquid nitrogen is a 100% automated and closed process so the introduction of contaminants is very reduced, unlike the gaseous nitrogen process. (author) [es

  19. Control of sources of ionizing radiation in Lithuania

    International Nuclear Information System (INIS)

    Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis

    1997-01-01

    Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented

  20. Temporal-spatial distribution of non-point source pollution in a drinking water source reservoir watershed based on SWAT

    Directory of Open Access Journals (Sweden)

    M. Wang

    2015-05-01

    Full Text Available The conservation of drinking water source reservoirs has a close relationship between regional economic development and people’s livelihood. Research on the non-point pollution characteristics in its watershed is crucial for reservoir security. Tang Pu Reservoir watershed was selected as the study area. The non-point pollution model of Tang Pu Reservoir was established based on the SWAT (Soil and Water Assessment Tool model. The model was adjusted to analyse the temporal-spatial distribution patterns of total nitrogen (TN and total phosphorus (TP. The results showed that the loss of TN and TP in the reservoir watershed were related to precipitation in flood season. And the annual changes showed an "M" shape. It was found that the contribution of loss of TN and TP accounted for 84.5% and 85.3% in high flow years, and for 70.3% and 69.7% in low flow years, respectively. The contributions in normal flow years were 62.9% and 63.3%, respectively. The TN and TP mainly arise from Wangtan town, Gulai town, and Wangyuan town, etc. In addition, it was found that the source of TN and TP showed consistency in space.

  1. A Method of Maximum Power Control in Single-phase Utility Interactive Photovoltaic Generation System by using PWM Current Source Inverter

    Science.gov (United States)

    Neba, Yasuhiko

    This paper deals with a maximum power point tracking (MPPT) control of the photovoltaic generation with the single-phase utility interactive inverter. The photovoltaic arrays are connected by employing the PWM current source inverter to the utility. The use of the pulsating dc current and voltage allows the maximum power point to be searched. The inverter can regulate the array voltage and keep the arrays to the maximum power. This paper gives the control method and the experimental results.

  2. Maximum power point tracker based on fuzzy logic

    International Nuclear Information System (INIS)

    Daoud, A.; Midoun, A.

    2006-01-01

    The solar energy is used as power source in photovoltaic power systems and the need for an intelligent power management system is important to obtain the maximum power from the limited solar panels. With the changing of the sun illumination due to variation of angle of incidence of sun radiation and of the temperature of the panels, Maximum Power Point Tracker (MPPT) enables optimization of solar power generation. The MPPT is a sub-system designed to extract the maximum power from a power source. In the case of solar panels power source. the maximum power point varies as a result of changes in its electrical characteristics which in turn are functions of radiation dose, temperature, ageing and other effects. The MPPT maximum the power output from panels for a given set of conditions by detecting the best working point of the power characteristic and then controls the current through the panels or the voltage across them. Many MPPT methods have been reported in literature. These techniques of MPPT can be classified into three main categories that include: lookup table methods, hill climbing methods and computational methods. The techniques vary according to the degree of sophistication, processing time and memory requirements. The perturbation and observation algorithm (hill climbing technique) is commonly used due to its ease of implementation, and relative tracking efficiency. However, it has been shown that when the insolation changes rapidly, the perturbation and observation method is slow to track the maximum power point. In recent years, the fuzzy controllers are used for maximum power point tracking. This method only requires the linguistic control rules for maximum power point, the mathematical model is not required and therefore the implementation of this control method is easy to real control system. In this paper, we we present a simple robust MPPT using fuzzy set theory where the hardware consists of the microchip's microcontroller unit control card and

  3. Control of radiation sources in Japan

    International Nuclear Information System (INIS)

    Maki, S.

    2001-01-01

    The report refers to the regulations for radioactive material in force in Japan, and to the organizations with responsibilities for regulating radiation sources. An outline of the law regulating the use of radiation sources and radioactive materials is provided, including its scope, types of radiation sources under control, exemptions and the system of notification, authorization and inspection. The experience of Japan with orphan sources is presented in three different cases, and the measures carried out to store the orphan sources in safe conditions. (author)

  4. Morphological control in polymer solar cells using low-boiling-point solvent additives

    Science.gov (United States)

    Mahadevapuram, Rakesh C.

    In the global search for clean, renewable energy sources, organic photovoltaics (OPVs) have recently been given much attention. Popular modern-day OPVs are made from solution-processible, carbon-based polymers (e.g. the model poly(3-hexylthiophene) that are intimately blended with fullerene derivatives (e.g. [6,6]-phenyl-C71-butyric acid methyl ester) to form what is known as the dispersed bulk-heterojunction (BHJ). This BHJ architecture has produced some of the most efficient OPVs to date, with reports closing in on 10% power conversion efficiency. To push efficiencies further into double digits, many groups have identified the BHJ nanomorphology---that is, the phase separations and grain sizes within the polymer: fullerene composite---as a key aspect in need of control and improvement. As a result, many methods, including thermal annealing, slow-drying (solvent) annealing, vapor annealing, and solvent additives, have been developed and studied to promote BHJ self-organization. Processing organic photovoltaic (OPV) blend solutions with high-boiling-point solvent additives has recently been used for morphological control in BHJ OPV cells. Here we show that even low-boiling-point solvents can be effective additives. When P3HT:PCBM OPV cells were processed with a low-boiling-point solvent tetrahydrafuran as an additive in parent solvent o-dichlorobenzene, charge extraction increased leading to fill factors as high as 69.5%, without low work-function cathodes, electrode buffer layers or thermal treatment. This was attributed to PCBM demixing from P3HT domains and better vertical phase separation, as indicated by photoluminescence lifetimes, hole mobilities, and shunt leakage currents. Dependence on solvent parameters and applicability beyond P3HT system was also investigated.

  5. 47 CFR 90.473 - Operation of internal transmitter control systems through licensed fixed control points.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operation of internal transmitter control... Transmitter Control Internal Transmitter Control Systems § 90.473 Operation of internal transmitter control systems through licensed fixed control points. An internal transmitter control system may be operated...

  6. Strengthening control over radioactive sources in authorized use and regaining control over orphan sources. National strategies

    International Nuclear Information System (INIS)

    2004-02-01

    The objective of this report is to provide practical guidance to States on the development of a national strategy for improving control over radioactive sources, particularly dangerous sources (Categories 1-3). Part of this process involves the determination of the magnitude of the potential problem with orphan and vulnerable sources and indeed, whether or not a national strategy is needed. The ultimate objective is that States will use this report to develop and then implement a plan of action that will result in all significant sources being managed in a safe and secure manner. This report attempts to provide both the background knowledge and the methodology necessary for an individual or small team of responsible persons to develop a national strategy for improving control over all radioactive sources, but especially orphan and vulnerable sources. The background knowledge given in Chapter 3 is an update of the information on practices that was given in IAEA-TECDOC-804, which focused on spent radioactive sources. After some introductory material, this report provides both the factual information and the general steps needed to develop and implement a national strategy. Part I contains background information for those who are not already familiar with the subject including the need for national strategies, the generic causes of loss of control of sources, with specific examples and the common applications of radioactive sources. Part II details the actual process for the development and implementation of a national strategy, which includes assessing the problem by first gathering specific and national information, determining the nature and magnitude of the problem, developing the national strategy by evaluating, and prioritizing possible solutions, implementing the strategy subsequent to a high level decision; and evaluating the effectiveness of the plan and making changes as a result until the desired objective is achieved. Searches for sources will be part of

  7. Hazard analysis and critical control point (HACCP) history and conceptual overview.

    Science.gov (United States)

    Hulebak, Karen L; Schlosser, Wayne

    2002-06-01

    The concept of Hazard Analysis and Critical Control Point (HACCP) is a system that enables the production of safe meat and poultry products through the thorough analysis of production processes, identification of all hazards that are likely to occur in the production establishment, the identification of critical points in the process at which these hazards may be introduced into product and therefore should be controlled, the establishment of critical limits for control at those points, the verification of these prescribed steps, and the methods by which the processing establishment and the regulatory authority can monitor how well process control through the HACCP plan is working. The history of the development of HACCP is reviewed, and examples of practical applications of HACCP are described.

  8. Critical Control Points in the Processing of Cassava Tuber for Ighu ...

    African Journals Online (AJOL)

    Determination of the critical control points in the processing of cassava tuber into Ighu was carried out. The critical control points were determined according to the Codex guidelines for the application of the HACCP system by conducting hazard analysis. Hazard analysis involved proper examination of each processing step ...

  9. Reproduction of nearby sources by imposing true interaural differences on a sound field control approach

    DEFF Research Database (Denmark)

    Badajoz, Javier; Chang, Ji-ho; Agerkvist, Finn T.

    2015-01-01

    In anechoic conditions, the Interaural Level Difference (ILD) is the most significant auditory cue to judge the distance to a sound source located within 1 m of the listener's head. This is due to the unique characteristics of a point source in its near field, which result in exceptionally high...... as Pressure Matching (PM), and a binaural control technique. While PM aims at reproducing the incident sound field, the objective of the binaural control technique is to ensure a correct reproduction of interaural differences. The combination of these two approaches gives rise to the following features: (i......, distance dependent ILDs. When reproducing the sound field of sources located near the head with line or circular arrays of loudspeakers, the reproduced ILDs are generally lower than expected, due to physical limitations. This study presents an approach that combines a sound field reproduction method, known...

  10. Advanced controls for light sources

    Science.gov (United States)

    Biedron, S. G.; Edelen, A. L.; Milton, S. V.

    2016-09-01

    We present a summary of our team's recent efforts in developing adaptive, artificial intelligence-inspired techniques specifically to address several control challenges that arise in machines/systems including those in particle accelerator systems. These techniques can readily be adapted to other systems such as lasers, beamline optics, etc… We are not at all suggesting that we create an autonomous system, but create a system with an intelligent control system, that can continually use operational data to improve itself and combines both traditional and advanced techniques. We believe that the system performance and reliability can be increased based on our findings. Another related point is that the controls sub-system of an overall system is usually not the heart of the system architecture or design process. More bluntly, often times all of the peripheral systems are considered as secondary to the main system components in the architecture design process because it is assumed that the controls system will be able to "fix" challenges found later with the sub-systems for overall system operation. We will show that this is not always the case and that it took an intelligent control application to overcome a sub-system's challenges. We will provide a recent example of such a "fix" with a standard controller and with an artificial intelligence-inspired controller. A final related point to be covered is that of system adaptation for requirements not original to a system's original design.

  11. High angle grain boundaries as sources or sinks for point defects

    Energy Technology Data Exchange (ETDEWEB)

    Balluffi, R.W.

    1979-09-01

    A secondary grain boundary dislocation climb model for high angle grain boundaries as sources/sinks for point defects is described in the light of recent advances in our knowledge of grain boundary structure. Experimental results are reviewed and are then compared with the expected behavior of the proposed model. Reasonably good consistency is found at the level of our present understanding of the subject. However, several gaps in our present knowledge still exist, and these are identified and discussed briefly.

  12. The Herschel Virgo Cluster Survey. XVII. SPIRE point-source catalogs and number counts

    Science.gov (United States)

    Pappalardo, Ciro; Bendo, George J.; Bianchi, Simone; Hunt, Leslie; Zibetti, Stefano; Corbelli, Edvige; di Serego Alighieri, Sperello; Grossi, Marco; Davies, Jonathan; Baes, Maarten; De Looze, Ilse; Fritz, Jacopo; Pohlen, Michael; Smith, Matthew W. L.; Verstappen, Joris; Boquien, Médéric; Boselli, Alessandro; Cortese, Luca; Hughes, Thomas; Viaene, Sebastien; Bizzocchi, Luca; Clemens, Marcel

    2015-01-01

    Aims: We present three independent catalogs of point-sources extracted from SPIRE images at 250, 350, and 500 μm, acquired with the Herschel Space Observatory as a part of the Herschel Virgo Cluster Survey (HeViCS). The catalogs have been cross-correlated to consistently extract the photometry at SPIRE wavelengths for each object. Methods: Sources have been detected using an iterative loop. The source positions are determined by estimating the likelihood to be a real source for each peak on the maps, according to the criterion defined in the sourceExtractorSussextractor task. The flux densities are estimated using the sourceExtractorTimeline, a timeline-based point source fitter that also determines the fitting procedure with the width of the Gaussian that best reproduces the source considered. Afterwards, each source is subtracted from the maps, removing a Gaussian function in every position with the full width half maximum equal to that estimated in sourceExtractorTimeline. This procedure improves the robustness of our algorithm in terms of source identification. We calculate the completeness and the flux accuracy by injecting artificial sources in the timeline and estimate the reliability of the catalog using a permutation method. Results: The HeViCS catalogs contain about 52 000, 42 200, and 18 700 sources selected at 250, 350, and 500 μm above 3σ and are ~75%, 62%, and 50% complete at flux densities of 20 mJy at 250, 350, 500 μm, respectively. We then measured source number counts at 250, 350, and 500 μm and compare them with previous data and semi-analytical models. We also cross-correlated the catalogs with the Sloan Digital Sky Survey to investigate the redshift distribution of the nearby sources. From this cross-correlation, we select ~2000 sources with reliable fluxes and a high signal-to-noise ratio, finding an average redshift z ~ 0.3 ± 0.22 and 0.25 (16-84 percentile). Conclusions: The number counts at 250, 350, and 500 μm show an increase in

  13. Control electronic platform based on floating-point DSP and FPGA for a NPC multilevel back-to-back converter

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Francisco J.; Cobreces, Santiago; Bueno, Emilio J.; Hernandez, Alvaro; Mateos, Raul; Espinosa, Felipe [Department of Electronics, University of Alcala, Alcala de Henares, Madrid (Spain)

    2008-09-15

    Modern energy concepts as Distributed Power Generation are changing the appearance of electric distribution and transmission and challenging power electronics researchers, which try to develop new solutions of electronic controllers. The aim is to enable the implementation of new and more complex control algorithms to verify the last standards related to the grid energy quality for new power converters, and, also, for equipments which nowadays are operating. This paper presents the design, implementation and test of a novel real-time controller for a Neutral Point Clamped (NPC) (three-level) multilevel converter based on a floating-point Digital Signal Processor (DSP) and on a Field-Programmable Gate Array (FPGA), by operating in a cooperative way. Although the proposed system can be readily applied to any power electronic application, in this work, it is focused on the next system: a 150 kVA back-to-back three-level NPC Voltage Source Converter (VSC) for wind power applications. (author)

  14. [Preliminary studies on critical control point of traceability system in wolfberry].

    Science.gov (United States)

    Liu, Sai; Xu, Chang-Qing; Li, Jian-Ling; Lin, Chen; Xu, Rong; Qiao, Hai-Li; Guo, Kun; Chen, Jun

    2016-07-01

    As a traditional Chinese medicine, wolfberry (Lycium barbarum) has a long cultivation history and a good industrial development foundation. With the development of wolfberry production, the expansion of cultivation area and the increased attention of governments and consumers on food safety, the quality and safety requirement of wolfberry is higher demanded. The quality tracing and traceability system of production entire processes is the important technology tools to protect the wolfberry safety, and to maintain sustained and healthy development of the wolfberry industry. Thus, this article analyzed the wolfberry quality management from the actual situation, the safety hazard sources were discussed according to the HACCP (hazard analysis and critical control point) and GAP (good agricultural practice for Chinese crude drugs), and to provide a reference for the traceability system of wolfberry. Copyright© by the Chinese Pharmaceutical Association.

  15. Control of sources of ionizing radiation in Lithuania

    Energy Technology Data Exchange (ETDEWEB)

    Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis [Radiation Protection Centre, Vilnius (Lithuania)

    1997-12-31

    Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented 2 refs., 2 tabs.; e-mail: rsc at post.omnitel.net

  16. Neutron generator tube ion source control apparatus

    International Nuclear Information System (INIS)

    Bridges, J.R.

    1982-01-01

    A pulsed neutron well logging system includes a neutron generator tube of the deuterium-tritium accelerator type and an ion source control apparatus providing extremely sharply time-defined neutron pulses. A low voltage control pulse supplied to an input by timing circuits turns a power FET on via a buffer-driver whereby a 2000 volt pulse is produced in the secondary of a pulse transformer and applied to the ion source of the tube. A rapid fall in this ion source control pulse is ensured by a quenching circuit wherein a one-shot responds to the falling edge of the control pulse and produces a 3 microsecond delay to compensate for the propagation delay. A second one-shot is triggered by the falling edge of the output of the first one-shot and gives an 8 microsecond pulse to turn on the power FET which, via an isolation transformer turns on a series-connected transistor to ground the secondary of the pulse transformer and the ion source. (author)

  17. Field-scale operation of methane biofiltration systems to mitigate point source methane emissions

    International Nuclear Information System (INIS)

    Hettiarachchi, Vijayamala C.; Hettiaratchi, Patrick J.; Mehrotra, Anil K.; Kumar, Sunil

    2011-01-01

    Methane biofiltration (MBF) is a novel low-cost technique for reducing low volume point source emissions of methane (CH 4 ). MBF uses a granular medium, such as soil or compost, to support the growth of methanotrophic bacteria responsible for converting CH 4 to carbon dioxide (CO 2 ) and water (H 2 O). A field research program was undertaken to evaluate the potential to treat low volume point source engineered CH 4 emissions using an MBF at a natural gas monitoring station. A new comprehensive three-dimensional numerical model was developed incorporating advection-diffusive flow of gas, biological reactions and heat and moisture flow. The one-dimensional version of this model was used as a guiding tool for designing and operating the MBF. The long-term monitoring results of the field MBF are also presented. The field MBF operated with no control of precipitation, evaporation, and temperature, provided more than 80% of CH 4 oxidation throughout spring, summer, and fall seasons. The numerical model was able to predict the CH 4 oxidation behavior of the field MBF with high accuracy. The numerical model simulations are presented for estimating CH 4 oxidation efficiencies under various operating conditions, including different filter bed depths and CH 4 flux rates. The field observations as well as numerical model simulations indicated that the long-term performance of MBFs is strongly dependent on environmental factors, such as ambient temperature and precipitation. - Highlights: → One-dimensional version of the model was used as a guiding tool for designing and operating the MBF. → Mathematical model predicted CH 4 oxidation behaviors of the field MBF with high accuracy i.e. (> 80 %). → Performance of MBF is dependent on ambient temperature and precipitation. - The developed numerical model simulations and field observations for estimating CH 4 oxidation efficiencies under various operating conditions indicate that the long-term performance of MBFs is strongly

  18. Wireless power charging using point of load controlled high frequency power converters

    Science.gov (United States)

    Miller, John M.; Campbell, Steven L.; Chambon, Paul H.; Seiber, Larry E.; White, Clifford P.

    2015-10-13

    An apparatus for wirelessly charging a battery of an electric vehicle is provided with a point of load control. The apparatus includes a base unit for generating a direct current (DC) voltage. The base unit is regulated by a power level controller. One or more point of load converters can be connected to the base unit by a conductor, with each point of load converter comprising a control signal generator that transmits a signal to the power level controller. The output power level of the DC voltage provided by the base unit is controlled by power level controller such that the power level is sufficient to power all active load converters when commanded to do so by any of the active controllers, without generating excessive power that may be otherwise wasted.

  19. Magnox fuel inventories. Experiment and calculation using a point source model

    International Nuclear Information System (INIS)

    Nair, S.

    1978-08-01

    The results of calculations of Magnox fuel inventories using the point source code RICE and associated Magnox reactor data set have been compared with experimental measurements for the actinide isotopes 234 , 235 , 236 , 238 U, 238 , 239 , 240 , 241 , 242 Pu, 241 , 243 Am and 242 , 244 Cm and the fission product isotopes 142 , 143 , 144 , 145 , 146 , 150 Nd, 95 Zr, 134 , 137 Cs, 144 Ce and daughter 144 Pr produced in four samples of spent Magnox fuel spanning the burnup range 3000 to 9000 MWd/Te. The neutron emissions from a further two samples were also measured and compared with RICE predictions. The results of the comparison were such as to justify the use of the code RICE for providing source terms for environmental impact studies, for the isotopes considered in the present work. (author)

  20. Using the Chandra Source-Finding Algorithm to Automatically Identify Solar X-ray Bright Points

    Science.gov (United States)

    Adams, Mitzi L.; Tennant, A.; Cirtain, J. M.

    2009-01-01

    This poster details a technique of bright point identification that is used to find sources in Chandra X-ray data. The algorithm, part of a program called LEXTRCT, searches for regions of a given size that are above a minimum signal to noise ratio. The algorithm allows selected pixels to be excluded from the source-finding, thus allowing exclusion of saturated pixels (from flares and/or active regions). For Chandra data the noise is determined by photon counting statistics, whereas solar telescopes typically integrate a flux. Thus the calculated signal-to-noise ratio is incorrect, but we find we can scale the number to get reasonable results. For example, Nakakubo and Hara (1998) find 297 bright points in a September 11, 1996 Yohkoh image; with judicious selection of signal-to-noise ratio, our algorithm finds 300 sources. To further assess the efficacy of the algorithm, we analyze a SOHO/EIT image (195 Angstroms) and compare results with those published in the literature (McIntosh and Gurman, 2005). Finally, we analyze three sets of data from Hinode, representing different parts of the decline to minimum of the solar cycle.

  1. KM3NeT/ARCA sensitivity and discovery potential for neutrino point-like sources

    Directory of Open Access Journals (Sweden)

    Trovato A.

    2016-01-01

    Full Text Available KM3NeT is a large research infrastructure with a network of deep-sea neutrino telescopes in the abyss of the Mediterranean Sea. Of these, the KM3NeT/ARCA detector, installed in the KM3NeT-It node of the network, is optimised for studying high-energy neutrinos of cosmic origin. Sensitivities to galactic sources such as the supernova remnant RXJ1713.7-3946 and the pulsar wind nebula Vela X are presented as well as sensitivities to a generic point source with an E−2 spectrum which represents an approximation for the spectrum of extragalactic candidate neutrino sources.

  2. Method of nuclear reactor control using a variable temperature load dependent set point

    International Nuclear Information System (INIS)

    Kelly, J.J.; Rambo, G.E.

    1982-01-01

    A method and apparatus for controlling a nuclear reactor in response to a variable average reactor coolant temperature set point is disclosed. The set point is dependent upon percent of full power load demand. A manually-actuated ''droop mode'' of control is provided whereby the reactor coolant temperature is allowed to drop below the set point temperature a predetermined amount wherein the control is switched from reactor control rods exclusively to feedwater flow

  3. General Approach to the Evolution of Singlet Nanoparticles from a Rapidly Quenched Point Source

    NARCIS (Netherlands)

    Feng, J.; Huang, Luyi; Ludvigsson, Linus; Messing, Maria; Maiser, A.; Biskos, G.; Schmidt-Ott, A.

    2016-01-01

    Among the numerous point vapor sources, microsecond-pulsed spark ablation at atmospheric pressure is a versatile and environmentally friendly method for producing ultrapure inorganic nanoparticles ranging from singlets having sizes smaller than 1 nm to larger agglomerated structures. Due to its fast

  4. Time-lapse controlled-source electromagnetics using interferometry

    NARCIS (Netherlands)

    Hunziker, J.W.; Slob, E.C.; Wapenaar, C.P.A.

    In time-lapse controlled-source electromagnetics, it is crucial that the source and the receivers are positioned at exactly the same location at all times of measurement. We use interferometry by multidimensional deconvolution (MDD) to overcome problems in repeatability of the source location.

  5. Pasteurised milk and implementation of HACCP (Hazard Analysis Critical Control Point

    Directory of Open Access Journals (Sweden)

    T.B Murdiati

    2004-10-01

    Full Text Available The purpose of pasteurisation is to destroy pathogen bacteria without affecting the taste, flavor, and nutritional value. A study on the implementation of HACCP (Hazard Analysis Critical Control Point in producing pasteurized milk was carried out in four processing unit of pasteurised milk, one in Jakarta, two in Bandung and one in Bogor. The critical control points in the production line were identified. Milk samples were collected from the critical points and were analysed for the total number of microbes. Antibiotic residues were detected on raw milks. The study indicated that one unit in Bandung dan one unit in Jakarta produced pasteurized milk with lower number of microbes than the other units, due to better management and control applied along the chain of production. Penisilin residues was detected in raw milk used by unit in Bogor. Six critical points and the hazard might arise in those points were identified, as well as how to prevent the hazards. Quality assurance system such as HACCP would be able to produce high quality and safety of pasteurised milk, and should be implemented gradually.

  6. Search for neutrino point sources with an all-sky autocorrelation analysis in IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Turcati, Andrea; Bernhard, Anna; Coenders, Stefan [TU, Munich (Germany); Collaboration: IceCube-Collaboration

    2016-07-01

    The IceCube Neutrino Observatory is a cubic kilometre scale neutrino telescope located in the Antarctic ice. Its full-sky field of view gives unique opportunities to study the neutrino emission from the Galactic and extragalactic sky. Recently, IceCube found the first signal of astrophysical neutrinos with energies up to the PeV scale, but the origin of these particles still remains unresolved. Given the observed flux, the absence of observations of bright point-sources is explainable with the presence of numerous weak sources. This scenario can be tested using autocorrelation methods. We present here the sensitivities and discovery potentials of a two-point angular correlation analysis performed on seven years of IceCube data, taken between 2008 and 2015. The test is applied on the northern and southern skies separately, using the neutrino energy information to improve the effectiveness of the method.

  7. Current status of agricultural and rural non-point source Pollution assessment in China

    International Nuclear Information System (INIS)

    Ongley, Edwin D.; Zhang Xiaolan; Yu Tao

    2010-01-01

    Estimates of non-point source (NPS) contribution to total water pollution in China range up to 81% for nitrogen and to 93% for phosphorus. We believe these values are too high, reflecting (a) misuse of estimation techniques that were developed in America under very different conditions and (b) lack of specificity on what is included as NPS. We compare primary methods used for NPS estimation in China with their use in America. Two observations are especially notable: empirical research is limited and does not provide an adequate basis for calibrating models nor for deriving export coefficients; the Chinese agricultural situation is so different than that of the United States that empirical data produced in America, as a basis for applying estimation techniques to rural NPS in China, often do not apply. We propose a set of national research and policy initiatives for future NPS research in China. - Estimation techniques used in China for non-point source pollution are evaluated as a basis for recommending future policies and research in NPS studies in China.

  8. Active AirCore Sampling: Constraining Point Sources of Methane and Other Gases with Fixed Wing Unmanned Aerial Systems

    Science.gov (United States)

    Bent, J. D.; Sweeney, C.; Tans, P. P.; Newberger, T.; Higgs, J. A.; Wolter, S.

    2017-12-01

    Accurate estimates of point source gas emissions are essential for reconciling top-down and bottom-up greenhouse gas measurements, but sampling such sources is challenging. Remote sensing methods are limited by resolution and cloud cover; aircraft methods are limited by air traffic control clearances, and the need to properly determine boundary layer height. A new sampling approach leverages the ability of unmanned aerial systems (UAS) to measure all the way to the surface near the source of emissions, improving sample resolution, and reducing the need to characterize a wide downstream swath, or measure to the full height of the planetary boundary layer (PBL). The "Active-AirCore" sampler, currently under development, will fly on a fixed wing UAS in Class G airspace, spiraling from the surface to 1200 ft AGL around point sources such as leaking oil wells to measure methane, carbon dioxide and carbon monoxide. The sampler collects a 100-meter long sample "core" of air in an 1/8" passivated stainless steel tube. This "core" is run on a high-precision instrument shortly after the UAS is recovered. Sample values are mapped to a specific geographic location by cross-referencing GPS and flow/pressure metadata, and fluxes are quantified by applying Gauss's theorem to the data, mapped onto the spatial "cylinder" circumscribed by the UAS. The AirCore-Active builds off the sampling ability and analytical approach of the related AirCore sampler, which profiles the atmosphere passively using a balloon launch platform, but will add an active pumping capability needed for near-surface horizontal sampling applications. Here, we show design elements, laboratory and field test results for methane, describe the overall goals of the mission, and discuss how the platform can be adapted, with minimal effort, to measure other gas species.

  9. Source apportionment of nitrogen and phosphorus from non-point source pollution in Nansi Lake Basin, China.

    Science.gov (United States)

    Zhang, Bao-Lei; Cui, Bo-Hao; Zhang, Shu-Min; Wu, Quan-Yuan; Yao, Lei

    2018-05-03

    Nitrogen (N) and phosphorus (P) from non-point source (NPS) pollution in Nansi Lake Basin greatly influenced the water quality of Nansi Lake, which is the determinant factor for the success of East Route of South-North Water Transfer Project in China. This research improved Johnes export coefficient model (ECM) by developing a method to determine the export coefficients of different land use types based on the hydrological and water quality data. Taking NPS total nitrogen (TN) and total phosphorus (TP) as the study objects, this study estimated the contributions of different pollution sources and analyzed their spatial distributions based on the improved ECM. The results underlined that the method for obtaining output coefficients of land use types using hydrology and water quality data is feasible and accurate, and is suitable for the study of NPS pollution at large-scale basins. The average output structure of NPS TN from land use, rural breeding and rural life is 33.6, 25.9, and 40.5%, and the NPS TP is 31.6, 43.7, and 24.7%, respectively. Especially, dry land was the main land use source for both NPS TN and TP pollution, with the contributed proportions of 81.3 and 81.8% respectively. The counties of Zaozhuang, Tengzhou, Caoxian, Yuncheng, and Shanxian had higher contribution rates and the counties of Dingtao, Juancheng, and Caoxian had the higher load intensities for both NPS TN and TP pollution. The results of this study allowed for an improvement in the understanding of the pollution source contribution and enabled researchers and planners to focus on the most important sources and regions of NPS pollution.

  10. Accuracy assessment of minimum control points for UAV photography and georeferencing

    Science.gov (United States)

    Skarlatos, D.; Procopiou, E.; Stavrou, G.; Gregoriou, M.

    2013-08-01

    In recent years, Autonomous Unmanned Aerial Vehicles (AUAV) became popular among researchers across disciplines because they combine many advantages. One major application is monitoring and mapping. Their ability to fly beyond eye sight autonomously, collecting data over large areas whenever, wherever, makes them excellent platform for monitoring hazardous areas or disasters. In both cases rapid mapping is needed while human access isn't always a given. Indeed, current automatic processing of aerial photos using photogrammetry and computer vision algorithms allows for rapid orthophomap production and Digital Surface Model (DSM) generation, as tools for monitoring and damage assessment. In such cases, control point measurement using GPS is either impossible, or time consuming or costly. This work investigates accuracies that can be attained using few or none control points over areas of one square kilometer, in two test sites; a typical block and a corridor survey. On board GPS data logged during AUAV's flight are being used for direct georeferencing, while ground check points are being used for evaluation. In addition various control point layouts are being tested using bundle adjustment for accuracy evaluation. Results indicate that it is possible to use on board single frequency GPS for direct georeferencing in cases of disaster management or areas without easy access, or even over featureless areas. Due to large numbers of tie points in the bundle adjustment, horizontal accuracy can be fulfilled with a rather small number of control points, but vertical accuracy may not.

  11. A search for hot post-AGE stars in the IRAS Point Source Catalog

    NARCIS (Netherlands)

    Oudmaijer, RD

    In this paper a first step is made to search for hot post-AGB stars in the IRAS Point Source Catalog. In order to find objects that evolved off the AGE a longer time ago than post-AGB objects discussed in the literature, objects that were not detected at 12 mu m by IRAS were selected. The selection

  12. CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

    International Nuclear Information System (INIS)

    Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar

    2002-01-01

    The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

  13. Urban stormwater source control policies: why and how?

    Directory of Open Access Journals (Sweden)

    G. Petrucci

    2014-09-01

    Full Text Available Stormwater source control is becoming a common strategy for urban stormwater management in many countries. It relies on regulations or other policy instruments compelling or inciting implementation, for each new urban development, of small-scale facilities to locally store and manage stormwater. Local authorities that pioneered source control since the 1980s have already observed that small-scale facilities systematically implemented over a catchment are able to influence its hydrological behaviour. This capability is the main strength of source control, as it allows compensation for the negative effects of urbanization. Yet, it also represents its main risk: if initial decision-making is not sufficiently accurate, source control can produce long-term negative effects. Because of its current spreading, source control will acquire an increasing role as a driver of hydrological changes in urban catchments, and the directions of these changes depend on current policy-making practices. This paper presents an analysis and a critical discussion of the main objectives that policy-makers attribute to stormwater source control. The investigation is based on a sample of French case studies, completed by a literature review for international comparison. It identifies four main objectives, some typical of urban stormwater management and some more innovative: flood reduction, receiving waters protection, sustainable development, costs reduction. The discussion focuses on how current policy-making practices are able to translate these objectives in concrete policy instruments, and on which knowledge and tools could improve this process. It is shown that for some objectives, basic knowledge is available, but the creation of policy instruments which are effective at the catchment scale and adapted to local conditions is still problematic. For other objectives, substantial lacks of knowledge exist, casting doubts on long-term effectiveness of current policy

  14. Orphan sources control in the Republic of Korea

    International Nuclear Information System (INIS)

    Kim, C.-W.

    2001-01-01

    In this paper, the orphan source control programme in Korea will be discussed. Orphan sources are, in general, classified into three groups: 1) Illegally trafficking radioactive sources; 2) Domestic loss of radioactive sources due to the bankruptcy of licensees or authorized suppliers; and 3) Contaminated metal scrap, which has been imported. There are, currently, two approaches going on to control and manage orphan sources in Korea. First, the Korean regulatory authority (Ministry of Science and Technology: MOST) will fully run an information system on radiation safety to effectively trace and monitor all radioactive sources in the country by the year 2001. Second, the regulatory authority strongly advises steel mill companies to closely scrutinize and inspect scrap metal through a scrap monitoring system when they attempt to reutilize it in order to prevent it from being contaminated by uncontrolled sources. The Korea Institute of Nuclear Safety (KINS), a regulatory expert organization, is carrying out a three-year multiphase project to control and monitor orphan sources in Korea. The system, called the Information System on Integrated Radiation Safety (ISIRS) on the inter- and intra-net system has been developed to effectively control and accurately monitor radioactive sources on a real time basis since 1998. If the system is successfully set up as scheduled by the middle of May next year, the regulatory authority will be able to control any reutilization of uncontrolled sources efficiently. At the same time, the system can also provide, not only licensees, suppliers, or perspective end users but also the Korean general public of interests with information on radiation safety, safe radiation management tools and public services. The system has been created because of the necessity to effectively control radioactive sources safely. Also, it serves to prepare necessary protective measures in a timely manner for abnormal events of uncontrolled radiation from

  15. Design and control of a point absorber wave energy converter with an open loop hydraulic transmission

    International Nuclear Information System (INIS)

    Fan, YaJun; Mu, AnLe; Ma, Tao

    2016-01-01

    Highlights: • Point absorber wave energy converter is presented. • Piston pump module captures and converts wave energy. • Hydraulic accumulator stores/releases the surplus energy. • Fuzzy controller adjusts the displacement of hydraulic motor. • Generator outputs meet the electricity demand precisely. - Abstract: In this paper, a point absorber wave energy converter combined with offshore wind turbine is proposed. In the system, the wave energy is captured and converted into hydraulic energy by a piston pump module, which is combined with a wind turbine floating platform, and then the hydraulic energy is converted into electricity energy by a variable displacement hydraulic motor and induction generator. In order to smooth and stabilize the captured wave energy, a hydraulic accumulator is applied to store and release the excess energy. In order to meet the demand power a fuzzy controller is designed to adjust the displacement of hydraulic motor and controlled the output power. Simulation under irregular wave condition has been carried out to verify the validity of the mathematical model and the effectiveness of the controller strategy. The results show that the wave energy converter system could deliver the required electricity power precisely as the motor output torque is controlled. The accumulator could damp out all the fluctuations in output power, so the wave energy would become a dispatchable power source.

  16. Microprocessor Controlled Maximum Power Point Tracker for Photovoltaic Application

    International Nuclear Information System (INIS)

    Jiya, J. D.; Tahirou, G.

    2002-01-01

    This paper presents a microprocessor controlled maximum power point tracker for photovoltaic module. Input current and voltage are measured and multiplied within the microprocessor, which contains an algorithm to seek the maximum power point. The duly cycle of the DC-DC converter, at which the maximum power occurs is obtained, noted and adjusted. The microprocessor constantly seeks for improvement of obtained power by varying the duty cycle

  17. Software architecture considerations for ion source control systems

    International Nuclear Information System (INIS)

    Sinclair, J.W.

    1997-09-01

    General characteristics of distributed control system software tools are examined from the perspective of ion source control system requirements. Emphasis is placed on strategies for building extensible, distributed systems in which the ion source element is one component of a larger system. Vsystem, a commercial software tool kit from Vista Control Systems was utilized extensively in the control system upgrade of the Holifield Radioactive Ion Beam Facility. Part of the control system is described and the characteristics of Vsystem are examined and compared with those of EPICS, the Experimental Physics and Industrial Control System

  18. Calcareous Fens - Source Feature Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Pursuant to the provisions of Minnesota Statutes, section 103G.223, this database contains points that represent calcareous fens as defined in Minnesota Rules, part...

  19. Application of random-point processes to the detection of radiation sources

    International Nuclear Information System (INIS)

    Woods, J.W.

    1978-01-01

    In this report the mathematical theory of random-point processes is reviewed and it is shown how use of the theory can obtain optimal solutions to the problem of detecting radiation sources. As noted, the theory also applies to image processing in low-light-level or low-count-rate situations. Paralleling Snyder's work, the theory is extended to the multichannel case of a continuous, two-dimensional (2-D), energy-time space. This extension essentially involves showing that the data are doubly stochastic Poisson (DSP) point processes in energy as well as time. Further, a new 2-D recursive formulation is presented for the radiation-detection problem with large computational savings over nonrecursive techniques when the number of channels is large (greater than or equal to 30). Finally, some adaptive strategies for on-line ''learning'' of unknown, time-varying signal and background-intensity parameters and statistics are present and discussed. These adaptive procedures apply when a complete statistical description is not available a priori

  20. An Improved Statistical Point-source Foreground Model for the Epoch of Reionization

    Energy Technology Data Exchange (ETDEWEB)

    Murray, S. G.; Trott, C. M.; Jordan, C. H. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia)

    2017-08-10

    We present a sophisticated statistical point-source foreground model for low-frequency radio Epoch of Reionization (EoR) experiments using the 21 cm neutral hydrogen emission line. Motivated by our understanding of the low-frequency radio sky, we enhance the realism of two model components compared with existing models: the source count distributions as a function of flux density and spatial position (source clustering), extending current formalisms for the foreground covariance of 2D power-spectral modes in 21 cm EoR experiments. The former we generalize to an arbitrarily broken power law, and the latter to an arbitrary isotropically correlated field. This paper presents expressions for the modified covariance under these extensions, and shows that for a more realistic source spatial distribution, extra covariance arises in the EoR window that was previously unaccounted for. Failure to include this contribution can yield bias in the final power-spectrum and under-estimate uncertainties, potentially leading to a false detection of signal. The extent of this effect is uncertain, owing to ignorance of physical model parameters, but we show that it is dependent on the relative abundance of faint sources, to the effect that our extension will become more important for future deep surveys. Finally, we show that under some parameter choices, ignoring source clustering can lead to false detections on large scales, due to both the induced bias and an artificial reduction in the estimated measurement uncertainty.

  1. An Improved Statistical Point-source Foreground Model for the Epoch of Reionization

    Science.gov (United States)

    Murray, S. G.; Trott, C. M.; Jordan, C. H.

    2017-08-01

    We present a sophisticated statistical point-source foreground model for low-frequency radio Epoch of Reionization (EoR) experiments using the 21 cm neutral hydrogen emission line. Motivated by our understanding of the low-frequency radio sky, we enhance the realism of two model components compared with existing models: the source count distributions as a function of flux density and spatial position (source clustering), extending current formalisms for the foreground covariance of 2D power-spectral modes in 21 cm EoR experiments. The former we generalize to an arbitrarily broken power law, and the latter to an arbitrary isotropically correlated field. This paper presents expressions for the modified covariance under these extensions, and shows that for a more realistic source spatial distribution, extra covariance arises in the EoR window that was previously unaccounted for. Failure to include this contribution can yield bias in the final power-spectrum and under-estimate uncertainties, potentially leading to a false detection of signal. The extent of this effect is uncertain, owing to ignorance of physical model parameters, but we show that it is dependent on the relative abundance of faint sources, to the effect that our extension will become more important for future deep surveys. Finally, we show that under some parameter choices, ignoring source clustering can lead to false detections on large scales, due to both the induced bias and an artificial reduction in the estimated measurement uncertainty.

  2. Neutral-point current modeling and control for Neutral-Point Clamped three-level converter drive with small DC-link capacitors

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, Sergio

    2011-01-01

    A Neutral-Point-Clamped (NPC) three-level inverter with small DC-link capacitors is presented in this paper. This inverter requires zero average neutral-point current for stable neutral-point potential. A simple carrier based modulation strategy is proposed for achieving zero average neutral...... drive with only 14 μF DC-link capacitors. A fast and stable performance of the neutral-point voltage controller is achieved and verified by experiments....

  3. Forced sound transmission through a finite-sized single leaf panel subject to a point source excitation.

    Science.gov (United States)

    Wang, Chong

    2018-03-01

    In the case of a point source in front of a panel, the wavefront of the incident wave is spherical. This paper discusses spherical sound waves transmitting through a finite sized panel. The forced sound transmission performance that predominates in the frequency range below the coincidence frequency is the focus. Given the point source located along the centerline of the panel, forced sound transmission coefficient is derived through introducing the sound radiation impedance for spherical incident waves. It is found that in addition to the panel mass, forced sound transmission loss also depends on the distance from the source to the panel as determined by the radiation impedance. Unlike the case of plane incident waves, sound transmission performance of a finite sized panel does not necessarily converge to that of an infinite panel, especially when the source is away from the panel. For practical applications, the normal incidence sound transmission loss expression of plane incident waves can be used if the distance between the source and panel d and the panel surface area S satisfy d/S>0.5. When d/S ≈0.1, the diffuse field sound transmission loss expression may be a good approximation. An empirical expression for d/S=0  is also given.

  4. Assessment of Groundwater Susceptibility to Non-Point Source Contaminants Using Three-Dimensional Transient Indexes.

    Science.gov (United States)

    Zhang, Yong; Weissmann, Gary S; Fogg, Graham E; Lu, Bingqing; Sun, HongGuang; Zheng, Chunmiao

    2018-06-05

    Groundwater susceptibility to non-point source contamination is typically quantified by stable indexes, while groundwater quality evolution (or deterioration globally) can be a long-term process that may last for decades and exhibit strong temporal variations. This study proposes a three-dimensional (3- d ), transient index map built upon physical models to characterize the complete temporal evolution of deep aquifer susceptibility. For illustration purposes, the previous travel time probability density (BTTPD) approach is extended to assess the 3- d deep groundwater susceptibility to non-point source contamination within a sequence stratigraphic framework observed in the Kings River fluvial fan (KRFF) aquifer. The BTTPD, which represents complete age distributions underlying a single groundwater sample in a regional-scale aquifer, is used as a quantitative, transient measure of aquifer susceptibility. The resultant 3- d imaging of susceptibility using the simulated BTTPDs in KRFF reveals the strong influence of regional-scale heterogeneity on susceptibility. The regional-scale incised-valley fill deposits increase the susceptibility of aquifers by enhancing rapid downward solute movement and displaying relatively narrow and young age distributions. In contrast, the regional-scale sequence-boundary paleosols within the open-fan deposits "protect" deep aquifers by slowing downward solute movement and displaying a relatively broad and old age distribution. Further comparison of the simulated susceptibility index maps to known contaminant distributions shows that these maps are generally consistent with the high concentration and quick evolution of 1,2-dibromo-3-chloropropane (DBCP) in groundwater around the incised-valley fill since the 1970s'. This application demonstrates that the BTTPDs can be used as quantitative and transient measures of deep aquifer susceptibility to non-point source contamination.

  5. The regulatory control of ionizing radiation sources in Lithuania

    International Nuclear Information System (INIS)

    Mastauskas, A.; Ziliukas, J.; Morkunas, G.

    1998-01-01

    The Radiation Protection Centre of the Ministry of Health is the regulatory authority responsible for radiation protection of the public and of workers using sources of ionizing radiation in Lithuania. One of its responsibilities is the control of radioactive sources, which includes keeping the registry, investigating persons arrested while illegally carrying or in possession of radioactive material, decision making and control of users of radioactive sources. The computer based registry contains a directory of more than 24,000 sources and some 800 users in research, medicine and industry. Most of these sources are found in smoke detectors and X ray equipment. The potentially most dangerous sources for therapy and industry (sealed and unsealed) are also listed in this registry. Problems connected with the regulatory control of radioactive sources in Lithuania are presented and their solution is discussed. (author)

  6. Model Predictive Control techniques with application to photovoltaic, DC Microgrid, and a multi-sourced hybrid energy system

    Science.gov (United States)

    Shadmand, Mohammad Bagher

    Renewable energy sources continue to gain popularity. However, two major limitations exist that prevent widespread adoption: availability and variability of the electricity generated and the cost of the equipment. The focus of this dissertation is Model Predictive Control (MPC) for optimal sized photovoltaic (PV), DC Microgrid, and multi-sourced hybrid energy systems. The main considered applications are: maximum power point tracking (MPPT) by MPC, droop predictive control of DC microgrid, MPC of grid-interaction inverter, MPC of a capacitor-less VAR compensator based on matrix converter (MC). This dissertation firstly investigates a multi-objective optimization technique for a hybrid distribution system. The variability of a high-penetration PV scenario is also studied when incorporated into the microgrid concept. Emerging (PV) technologies have enabled the creation of contoured and conformal PV surfaces; the effect of using non-planar PV modules on variability is also analyzed. The proposed predictive control to achieve maximum power point for isolated and grid-tied PV systems speeds up the control loop since it predicts error before the switching signal is applied to the converter. The low conversion efficiency of PV cells means we want to ensure always operating at maximum possible power point to make the system economical. Thus the proposed MPPT technique can capture more energy compared to the conventional MPPT techniques from same amount of installed solar panel. Because of the MPPT requirement, the output voltage of the converter may vary. Therefore a droop control is needed to feed multiple arrays of photovoltaic systems to a DC bus in microgrid community. Development of a droop control technique by means of predictive control is another application of this dissertation. Reactive power, denoted as Volt Ampere Reactive (VAR), has several undesirable consequences on AC power system network such as reduction in power transfer capability and increase in

  7. Gamma Rays from the Inner Milky Way: Dark Matter or Point Sources?

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    Studies of data from the Fermi Gamma-Ray Space Telescope have revealed bright gamma-ray emission from the central regions of our galaxy, with a spatial and spectral profile consistent with annihilating dark matter. I will present a new model-independent analysis that suggests that rather than originating from dark matter, the GeV excess may arise from a surprising new population of as-yet-unresolved gamma-ray point sources in the heart of the Milky Way.

  8. Control of sealed sources and equipments used in gammagraphy

    International Nuclear Information System (INIS)

    Sahyun, A.; Sordi, G.-M.A.A.; Biazzini Filho, F.L.

    1988-01-01

    The Radiation Protection Department of the IPEN-CNEN/SP, in 1987, formed a section incharged to control all radioactive material: a) received by the IPEN-CNEN/SP; b) produced by the IPEN-CNEN/SP; c) delivered from the IPEN-CNEN/SP. The aim of this section is to maintain a permanent control of all radioactive sources movement got at the IPEN-CNEN/SP. This control is performed with a microcomputer, trademark MICRODIGITAL, model TK3000 //e, 256 KBytes of memory, utilizing the TOTALWORKS program. This program permits to have the origin, characteristics and address of the radioactive sources, its sites in the IPEN, its uses, etc. Already we have put in the microcomputer, the control of the sealed sources produced used in nondestructive test, the inspection control of the gamagraphy irradiator and the control of the depleted sources. The next step is to introduce in the computer the inspection of the remote control of the irradiator. The aim of this paper is to describe the control program that was already put on. This radioactive material control was started with the sealed sources used in gamagraphy because we believe that is the field with the most likelihood of accident in the population, and therefore it's that need the most hard control about the site and the performance of the irradiation facility. (author) [pt

  9. An improved export coefficient model to estimate non-point source phosphorus pollution risks under complex precipitation and terrain conditions.

    Science.gov (United States)

    Cheng, Xian; Chen, Liding; Sun, Ranhao; Jing, Yongcai

    2018-05-15

    To control non-point source (NPS) pollution, it is important to estimate NPS pollution exports and identify sources of pollution. Precipitation and terrain have large impacts on the export and transport of NPS pollutants. We established an improved export coefficient model (IECM) to estimate the amount of agricultural and rural NPS total phosphorus (TP) exported from the Luanhe River Basin (LRB) in northern China. The TP concentrations of rivers from 35 selected catchments in the LRB were used to test the model's explanation capacity and accuracy. The simulation results showed that, in 2013, the average TP export was 57.20 t at the catchment scale. The mean TP export intensity in the LRB was 289.40 kg/km 2 , which was much higher than those of other basins in China. In the LRB topographic regions, the TP export intensity was the highest in the south Yanshan Mountains and was followed by the plain area, the north Yanshan Mountains, and the Bashang Plateau. Among the three pollution categories, the contribution ratios to TP export were, from high to low, the rural population (59.44%), livestock husbandry (22.24%), and land-use types (18.32%). Among all ten pollution sources, the contribution ratios from the rural population (59.44%), pigs (14.40%), and arable land (10.52%) ranked as the top three sources. This study provides information that decision makers and planners can use to develop sustainable measures for the prevention and control of NPS pollution in semi-arid regions.

  10. Feedback control of Zero Moment Point for stable bipedal walking

    NARCIS (Netherlands)

    Looij, van de R.M.A.; Nijmeijer, H.; Kostic, D.

    2014-01-01

    In order to prevent the humanoid robot TUlip from falling a start has been made with a Zero Moment Point (ZMP) based controller. The chosen controller, which is called the Linear Inverted Pendulum Tracker (LIPT) controller, is based upon a lag between the real and reference ZMP and is used in

  11. Optical tools and techniques for aligning solar payloads with the SPARCS control system. [Solar Pointing Aerobee Rocket Control System

    Science.gov (United States)

    Thomas, N. L.; Chisel, D. M.

    1976-01-01

    The success of a rocket-borne experiment depends not only on the pointing of the attitude control system, but on the alignment of the attitude control system to the payload. To ensure proper alignment, special optical tools and alignment techniques are required. Those that were used in the SPARCS program are described and discussed herein. These tools include theodolites, autocollimators, a 38-cm diameter solar simulator, a high-performance 1-m heliostat to provide a stable solar source during the integration of the rocket payload, a portable 75-cm sun tracker for use at the launch site, and an innovation called the Solar Alignment Prism. Using the real sun as the primary reference under field conditions, the Solar Alignment Prism facilitates the coalignment of the attitude sun sensor with the payload. The alignment techniques were developed to ensure the precise alignment of the solar payloads to the SPARCS attitude sensors during payload integration and to verify the required alignment under field conditions just prior to launch.

  12. High frequency seismic signal generated by landslides on complex topographies: from point source to spatially distributed sources

    Science.gov (United States)

    Mangeney, A.; Kuehnert, J.; Capdeville, Y.; Durand, V.; Stutzmann, E.; Kone, E. H.; Sethi, S.

    2017-12-01

    During their flow along the topography, landslides generate seismic waves in a wide frequency range. These so called landquakes can be recorded at very large distances (a few hundreds of km for large landslides). The recorded signals depend on the landslide seismic source and the seismic wave propagation. If the wave propagation is well understood, the seismic signals can be inverted for the seismic source and thus can be used to get information on the landslide properties and dynamics. Analysis and modeling of long period seismic signals (10-150s) have helped in this way to discriminate between different landslide scenarios and to constrain rheological parameters (e.g. Favreau et al., 2010). This was possible as topography poorly affects wave propagation at these long periods and the landslide seismic source can be approximated as a point source. In the near-field and at higher frequencies (> 1 Hz) the spatial extent of the source has to be taken into account and the influence of the topography on the recorded seismic signal should be quantified in order to extract information on the landslide properties and dynamics. The characteristic signature of distributed sources and varying topographies is studied as a function of frequency and recording distance.The time dependent spatial distribution of the forces applied to the ground by the landslide are obtained using granular flow numerical modeling on 3D topography. The generated seismic waves are simulated using the spectral element method. The simulated seismic signal is compared to observed seismic data from rockfalls at the Dolomieu Crater of Piton de la Fournaise (La Réunion).Favreau, P., Mangeney, A., Lucas, A., Crosta, G., and Bouchut, F. (2010). Numerical modeling of landquakes. Geophysical Research Letters, 37(15):1-5.

  13. 10 CFR 36.31 - Control of source movement.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Control of source movement. 36.31 Section 36.31 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Design and Performance Requirements for Irradiators § 36.31 Control of source movement. (a) The mechanism that moves the...

  14. Early Versus Delayed Source Control in Open Abdomen Management for Severe Intra-abdominal Infections: A Retrospective Analysis on 111 Cases.

    Science.gov (United States)

    Rausei, Stefano; Pappalardo, Vincenzo; Ruspi, Laura; Colella, Antonio; Giudici, Simone; Ardita, Vincenzo; Frattini, Francesco; Rovera, Francesca; Boni, Luigi; Dionigi, Gianlorenzo

    2018-03-01

    Time to source control plays a determinant prognostic role in patients having severe intra-abdominal infections (IAIs). Open abdomen (OA) management became an effective treatment option for peritonitis. Aim of this study was to analyze the correlation between time to source control and outcome in patients presenting with abdominal sepsis and treated by OA. We retrospectively analyzed 111 patients affected by abdominal sepsis and treated with OA from May 2007 to May 2015. Patients were classified according to time interval from first patient evaluation to source control. The end points were intra-hospital mortality and primary fascial closure rate. The in-hospital mortality rate was 21.6% (24/111), and the primary fascial closure rate was 90.9% (101/111). A time to source control ≥6 h resulted significantly associated with a poor prognosis and a lower fascial closure rate (mortality 27.0 vs 9.0%, p = 0.04; primary fascial closure 86 vs 100%, p = 0.02). We observed a direct increase in mortality (and a reduction in closure rate) for each 6-h delay in surgery to source control. Early source control using OA management significantly improves outcome of patients with severe IAIs. This damage control approach well fits to the treatment of time-related conditions, particularly in case of critically ill patients.

  15. Identification of 'Point A' as the prevalent source of error in cephalometric analysis of lateral radiographs.

    Science.gov (United States)

    Grogger, P; Sacher, C; Weber, S; Millesi, G; Seemann, R

    2018-04-10

    Deviations in measuring dentofacial components in a lateral X-ray represent a major hurdle in the subsequent treatment of dysgnathic patients. In a retrospective study, we investigated the most prevalent source of error in the following commonly used cephalometric measurements: the angles Sella-Nasion-Point A (SNA), Sella-Nasion-Point B (SNB) and Point A-Nasion-Point B (ANB); the Wits appraisal; the anteroposterior dysplasia indicator (APDI); and the overbite depth indicator (ODI). Preoperative lateral radiographic images of patients with dentofacial deformities were collected and the landmarks digitally traced by three independent raters. Cephalometric analysis was automatically performed based on 1116 tracings. Error analysis identified the x-coordinate of Point A as the prevalent source of error in all investigated measurements, except SNB, in which it is not incorporated. In SNB, the y-coordinate of Nasion predominated error variance. SNB showed lowest inter-rater variation. In addition, our observations confirmed previous studies showing that landmark identification variance follows characteristic error envelopes in the highest number of tracings analysed up to now. Variance orthogonal to defining planes was of relevance, while variance parallel to planes was not. Taking these findings into account, orthognathic surgeons as well as orthodontists would be able to perform cephalometry more accurately and accomplish better therapeutic results. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Aab, A. [Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud Universiteit, Nijmegen (Netherlands); Abreu, P. [Laboratório de Instrumentação e Física Experimental de Partículas—LIP and Instituto Superior Técnico—IST, Universidade de Lisboa—UL, Lisbon (Portugal); Aglietta, M. [INFN, Sezione di Torino, Torino (Italy); Samarai, I. Al [Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3, Paris (France); Albuquerque, I. F. M. [Universidade de São Paulo, Inst. de Física, São Paulo (Brazil); Allekotte, I. [Centro Atómico Bariloche and Instituto Balseiro (CNEA-UNCuyo-CONICET), San Carlos de Bariloche (Argentina); Almela, A. [Instituto de Tecnologías en Detección y Astropartículas (CNEA, CONICET, UNSAM), Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, Buenos Aires (Argentina); Castillo, J. Alvarez [Universidad Nacional Autónoma de México, México, D. F., México (Mexico); Alvarez-Muñiz, J. [Universidad de Santiago de Compostela, La Coruña (Spain); Anastasi, G. A. [Gran Sasso Science Institute (INFN), L’Aquila (Italy); and others

    2017-03-10

    Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p -values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictions of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.

  17. Methane Flux Estimation from Point Sources using GOSAT Target Observation: Detection Limit and Improvements with Next Generation Instruments

    Science.gov (United States)

    Kuze, A.; Suto, H.; Kataoka, F.; Shiomi, K.; Kondo, Y.; Crisp, D.; Butz, A.

    2017-12-01

    Atmospheric methane (CH4) has an important role in global radiative forcing of climate but its emission estimates have larger uncertainties than carbon dioxide (CO2). The area of anthropogenic emission sources is usually much smaller than 100 km2. The Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observing SATellite (GOSAT) has measured CO2 and CH4 column density using sun light reflected from the earth's surface. It has an agile pointing system and its footprint can cover 87-km2 with a single detector. By specifying pointing angles and observation time for every orbit, TANSO-FTS can target various CH4 point sources together with reference points every 3 day over years. We selected a reference point that represents CH4 background density before or after targeting a point source. By combining satellite-measured enhancement of the CH4 column density and surface measured wind data or estimates from the Weather Research and Forecasting (WRF) model, we estimated CH4emission amounts. Here, we picked up two sites in the US West Coast, where clear sky frequency is high and a series of data are available. The natural gas leak at Aliso Canyon showed a large enhancement and its decrease with time since the initial blowout. We present time series of flux estimation assuming the source is single point without influx. The observation of the cattle feedlot in Chino, California has weather station within the TANSO-FTS footprint. The wind speed is monitored continuously and the wind direction is stable at the time of GOSAT overpass. The large TANSO-FTS footprint and strong wind decreases enhancement below noise level. Weak wind shows enhancements in CH4, but the velocity data have large uncertainties. We show the detection limit of single samples and how to reduce uncertainty using time series of satellite data. We will propose that the next generation instruments for accurate anthropogenic CO2 and CH

  18. DISCRIMINATION OF NATURAL AND NON-POINT SOURCE EFFECTS FROM ANTHROGENIC EFFECTS AS REFLECTED IN BENTHIC STATE IN THREE ESTUARIES IN NEW ENGLAND

    Science.gov (United States)

    In order to protect estuarine resources, managers must be able to discern the effects of natural conditions and non-point source effects, and separate them from multiple anthropogenic point source effects. Our approach was to evaluate benthic community assemblages, riverine nitro...

  19. Stationary point of the radiometric control of cesium contamination of agricultural animals

    International Nuclear Information System (INIS)

    1997-01-01

    Stationary point of the radiometric control of cesium contamination of an agricultural animals. Is intended for vital measurements of the contents of radiocesium in muscular tissue of a cattle. Can be used on cattle-breeding farms, providing points, in meat factories and personal facilities. As a base means for accommodation of the control point the motor-car is used. Design of the car allows to automate operations on deployment of the control point on a place and translation of one to a transport mode. Limits of measured specific activity of cesium contamination of a cattle is up 5*10 -9 to 5*10 -6 Ci/kg. The basic error on the bottom limit of measurement at confidence coefficient 0,95 is no more than 30%. Measurement time for the bottom limit of determined specific activity is no more than 30 s. There is automatic measurement mode. Type of a power is 220 V, 50 Hz. Range of working temperatures is up -15 to +35 centigrade. Relative humidity is no more than 98% at 25 centigrade. External gamma background is till 0.035 mR/h. Time of installation and dismantle of stationary control point is no more than 1,5 hours. The direct radiometric control in divo allows to fulfil and to use biotechnological process of removing of cesium isotopes from body of animals for decrease of levels of radioactive contamination

  20. Modeling of Maximum Power Point Tracking Controller for Solar Power System

    Directory of Open Access Journals (Sweden)

    Aryuanto Soetedjo

    2012-09-01

    Full Text Available In this paper, a Maximum Power Point Tracking (MPPT controller for solar power system is modeled using MATLAB Simulink. The model consists of PV module, buck converter, and MPPT controller. The contribution of the work is in the modeling of buck converter that allowing the input voltage of the converter, i.e. output voltage of PV is changed by varying the duty cycle, so that the maximum power point could be tracked when the environmental changes. The simulation results show that the developed model performs well in tracking the maximum power point (MPP of the PV module using Perturb and Observe (P&O Algorithm.

  1. UHE γ-rays from point sources based on GRAPES-I observations

    International Nuclear Information System (INIS)

    Gupta, S.K.; Sreekantan, B.V.; Srivatsan, R.; Tonwar, S.C.

    1993-01-01

    An experiment called GRAPES I (Gamma Ray Astronomy at PeV EnergieS) was set up in 1984 at Ooty in India, using 24 scintillation counters, to detect Extensive Air Showers (EAS) produced in the atmosphere by the primary cosmic radiation. The goal of the experiment has been to search for Ultra High Energy (UHE) γ-rays (E≥10 14 eV) from point sources in the sky. Here we discuss the results on X-ray binaries CYG X-3, HER X-1 and SCO X-1 obtained with GRAPES I experiment which covers the period 1984--87

  2. POWER-LAW TEMPLATE FOR INFRARED POINT-SOURCE CLUSTERING

    Energy Technology Data Exchange (ETDEWEB)

    Addison, Graeme E.; Dunkley, Joanna [Sub-department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Hajian, Amir; Das, Sudeep; Hincks, Adam D.; Page, Lyman A.; Staggs, Suzanne T. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Viero, Marco [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Bond, J. Richard [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Devlin, Mark J.; Reese, Erik D. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Halpern, Mark; Scott, Douglas [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Hlozek, Renee; Marriage, Tobias A.; Spergel, David N. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban 4041 (South Africa); Wollack, Edward [NASA/Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States)

    2012-06-20

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217, 353, 545, and 857 GHz, over angular scales 100 {approx}< l {approx}< 2200), the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST; 250, 350, and 500 {mu}m; 1000 {approx}< l {approx}< 9000), and from correlating BLAST and Atacama Cosmology Telescope (ACT; 148 and 218 GHz) maps. We find that the clustered power over the range of angular scales and frequencies considered is well fitted by a simple power law of the form C{sup clust}{sub l}{proportional_to}l{sup -n} with n = 1.25 {+-} 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, {nu}{sup {beta}} B({nu}, T{sub eff}), with a single emissivity index {beta} = 2.20 {+-} 0.07 and effective temperature T{sub eff} = 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be {alpha}{sub 150-220} = 3.68 {+-} 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in cosmic microwave background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  3. Super-resolution for a point source better than λ/500 using positive refraction

    Science.gov (United States)

    Miñano, Juan C.; Marqués, Ricardo; González, Juan C.; Benítez, Pablo; Delgado, Vicente; Grabovickic, Dejan; Freire, Manuel

    2011-12-01

    Leonhardt (2009 New J. Phys. 11 093040) demonstrated that the two-dimensional (2D) Maxwell fish eye (MFE) lens can focus perfectly 2D Helmholtz waves of arbitrary frequency; that is, it can transport perfectly an outward (monopole) 2D Helmholtz wave field, generated by a point source, towards a ‘perfect point drain’ located at the corresponding image point. Moreover, a prototype with λ/5 super-resolution property for one microwave frequency has been manufactured and tested (Ma et al 2010 arXiv:1007.2530v1; Ma et al 2010 New J. Phys. 13 033016). However, neither software simulations nor experimental measurements for a broad band of frequencies have yet been reported. Here, we present steady-state simulations with a non-perfect drain for a device equivalent to the MFE, called the spherical geodesic waveguide (SGW), which predicts up to λ/500 super-resolution close to discrete frequencies. Out of these frequencies, the SGW does not show super-resolution in the analysis carried out.

  4. Super-resolution for a point source better than λ/500 using positive refraction

    International Nuclear Information System (INIS)

    Miñano, Juan C; González, Juan C; Benítez, Pablo; Grabovickic, Dejan; Marqués, Ricardo; Delgado, Vicente; Freire, Manuel

    2011-01-01

    Leonhardt (2009 New J. Phys. 11 093040) demonstrated that the two-dimensional (2D) Maxwell fish eye (MFE) lens can focus perfectly 2D Helmholtz waves of arbitrary frequency; that is, it can transport perfectly an outward (monopole) 2D Helmholtz wave field, generated by a point source, towards a ‘perfect point drain’ located at the corresponding image point. Moreover, a prototype with λ/5 super-resolution property for one microwave frequency has been manufactured and tested (Ma et al 2010 arXiv:1007.2530v1; Ma et al 2010 New J. Phys. 13 033016). However, neither software simulations nor experimental measurements for a broad band of frequencies have yet been reported. Here, we present steady-state simulations with a non-perfect drain for a device equivalent to the MFE, called the spherical geodesic waveguide (SGW), which predicts up to λ/500 super-resolution close to discrete frequencies. Out of these frequencies, the SGW does not show super-resolution in the analysis carried out. (paper)

  5. Analysis of point source pollution and water environmental quality variation trends in the Nansi Lake basin from 2002 to 2012.

    Science.gov (United States)

    Wang, Weiliang; Liu, Xiaohui; Wang, Yufan; Guo, Xiaochun; Lu, Shaoyong

    2016-03-01

    Based on the data analysis of the water environmental quality and economic development from 2002 to 2012 in the Nansi Lake basin, the correlation and change between the water environmental quality and economic development were studied. Results showed that the GDP and wastewater emissions of point source in the Nansi Lake basin had an average annual growth of 7.30 and 7.68 %, respectively, from 2002 to 2012. The emissions of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) had the average annual decrease of 7.69 and 6.79 % in 2012, respectively, compared to 2002. Basin water quality overall improved, reaching the Class III of the "Environmental quality standards for surface water (GB3838-2002)," in which the main reason was that sewage treatment rate increased gradually and was above 90 % in 2012 (an increase of 10 % compared to 2002) with the progress of pollution abatement technology and the implementation of relevant policies and regulations. The contribution of water environmental pollution was analyzed from related cities (Ji'ning, Zaozhuang, Heze). Results indicated that Ji'ning had the largest contribution to water pollution of the Nansi Lake basin, and the pollutant from domestic sources accounted for a higher percentage compared to industrial sources. The wastewater, COD, and NH3-N mainly came from mining and washing of coal, manufacture of raw chemical materials and chemical products, papermaking industry, and food processing industry. According to the water pollution characteristics of the Nansi Lake basin, the basin pollution treatment strategy and prevention and treatment system were dissected to provide a scientific basis for prevention and control of lakeside point source pollution along the Nansi Lake.

  6. Correlation Wave-Front Sensing Algorithms for Shack-Hartmann-Based Adaptive Optics using a Point Source

    International Nuclear Information System (INIS)

    Poynee, L A

    2003-01-01

    Shack-Hartmann based Adaptive Optics system with a point-source reference normally use a wave-front sensing algorithm that estimates the centroid (center of mass) of the point-source image 'spot' to determine the wave-front slope. The centroiding algorithm suffers for several weaknesses. For a small number of pixels, the algorithm gain is dependent on spot size. The use of many pixels on the detector leads to significant propagation of read noise. Finally, background light or spot halo aberrations can skew results. In this paper an alternative algorithm that suffers from none of these problems is proposed: correlation of the spot with a ideal reference spot. The correlation method is derived and a theoretical analysis evaluates its performance in comparison with centroiding. Both simulation and data from real AO systems are used to illustrate the results. The correlation algorithm is more robust than centroiding, but requires more computation

  7. Major and Trace Element Fluxes to the Ganges River: Significance of Small Flood Plain Tributary as Non-Point Pollution Source

    Science.gov (United States)

    Lakshmi, V.; Sen, I. S.; Mishra, G.

    2017-12-01

    There has been much discussion amongst biologists, ecologists, chemists, geologists, environmental firms, and science policy makers about the impact of human activities on river health. As a result, multiple river restoration projects are on going on many large river basins around the world. In the Indian subcontinent, the Ganges River is the focal point of all restoration actions as it provides food and water security to half a billion people. Serious concerns have been raised about the quality of Ganga water as toxic chemicals and many more enters the river system through point-sources such as direct wastewater discharge to rivers, or non-point-sources. Point source pollution can be easily identified and remedial actions can be taken; however, non-point pollution sources are harder to quantify and mitigate. A large non-point pollution source in the Indo-Gangetic floodplain is the network of small floodplain rivers. However, these rivers are rarely studied since they are small in catchment area ( 1000-10,000 km2) and discharge (knowledge gap we have monitored the Pandu River for one year between February 2015 and April 2016. Pandu river is 242 km long and is a right bank tributary of Ganges with a total catchment area of 1495 km2. Water samples were collected every month for dissolved major and trace elements. Here we show that the concentration of heavy metals in river Pandu is in higher range as compared to the world river average, and all the dissolved elements shows a large spatial-temporal variation. We show that the Pandu river exports 192170, 168517, 57802, 32769, 29663, 1043, 279, 241, 225, 162, 97, 28, 25, 22, 20, 8, 4 Kg/yr of Ca, Na, Mg, K, Si, Sr, Zn, B, Ba, Mn, Al, Li, Rb, Mo, U, Cu, and Sb, respectively, to the Ganga river, and the exported chemical flux effects the water chemistry of the Ganga river downstream of its confluence point. We further speculate that small floodplain rivers is an important source that contributes to the dissolved chemical

  8. Super-resolution for a point source using positive refraction

    Science.gov (United States)

    Miñano, Juan C.; Benítez, Pablo; González, Juan C.; Grabovičkić, Dejan; Ahmadpanahi, Hamed

    Leonhardt demonstrated (2009) that the 2D Maxwell Fish Eye lens (MFE) can focus perfectly 2D Helmholtz waves of arbitrary frequency, i.e., it can transport perfectly an outward (monopole) 2D Helmholtz wave field, generated by a point source, towards a receptor called "perfect drain" (PD) located at the corresponding MFE image point. The PD has the property of absorbing the complete radiation without radiation or scattering and it has been claimed as necessary to obtain super-resolution (SR) in the MFE. However, a prototype using a "drain" different from the PD has shown λ/5 resolution for microwave frequencies (Ma et al, 2010). Recently, the SR properties of a device equivalent to the MFE, called the Spherical Geodesic Waveguide (SGW) (Miñano et al, 2012) have been analyzed. The reported results show resolution up to λ /3000, for the SGW loaded with the perfect drain, and up to λ /500 for the SGW without perfect drain. The perfect drain was realized as a coaxial probe loaded with properly calculated impedance. The SGW provides SR only in a narrow band of frequencies close to the resonance Schumann frequencies. Here we analyze the SGW loaded with a small "perfect drain region" (González et al, 2011). This drain is designed as a region made of a material with complex permittivity. The comparative results show that there is no significant difference in the SR properties for both perfect drain designs.

  9. Hyporheic Interfaces Serve as Ecological Control Points for Mountainous Landscape Biological Productivity

    Science.gov (United States)

    Newcomer, M. E.; Dwivedi, D.; Raberg, J.; Fox, P. M.; Nico, P. S.; Wainwright, H. M.; Conrad, M. E.; Bill, M.; Bouskill, N.; Williams, K. H.; Hubbard, S.; Steefel, C. I.

    2017-12-01

    Riverine systems in snow-dominated mountainous regions often express complex biogeochemistry and river nutrient indicators as a function of hydrologic variability. In early spring, meltwater infiltration from a ripened snowpack creates a hydrological gradient through hillslopes, floodplains, and hyporheic zones. During this time, these systems are more-or-less a passive filter that allows the rising limb of the hydrograph to display chemo-dynamic relationships (inversely proportional) with solutes and nutrients. During the growing season, temperatures, plants, microbes, and hydrologic gradients shift dramatically and activate hyporheic-zone biogeochemistry as a major control on water nutrient degradation. Hyporheic biogeochemical reliance on the timing of meltwater infiltration and the possibility of a longer vernal window under future climate change indicates the importance of hyporheic cycling as the dominant ecological control point on carbon and nitrogen fluxes and transformations. The objective of our study is to develop a predictive understanding of the subsurface and surface controls on hyporheic biogeochemical behavior through data-model integration. Data from our 2017 field campaign in the East River, Colorado, a pristine, mountainous watershed, were taken at key times during the rising, peak, falling, and dry limb of the hydrograph. Throughout multiple locations across this spatial and temporal gradient, we measured surface and subsurface gases, geochemistry, isotopes, and hydrological flow conditions and used this data to constrain a numerical flow and reactive transport model of the hyporheic zone that included microbial and flow feedback dynamics. Our data coupled with the predictive power of our numerical model reveal that the hyporheic zone serves dual roles throughout the year—as a net source of nutrients and solutes during the early vernal phase, shifting to a net sink of nutrients during the summer dry season. The possibility of a future

  10. CHANDRA ACIS SURVEY OF X-RAY POINT SOURCES: THE SOURCE CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Song; Liu, Jifeng; Qiu, Yanli; Bai, Yu; Yang, Huiqin; Guo, Jincheng; Zhang, Peng, E-mail: jfliu@bao.ac.cn, E-mail: songw@bao.ac.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2016-06-01

    The Chandra archival data is a valuable resource for various studies on different X-ray astronomy topics. In this paper, we utilize this wealth of information and present a uniformly processed data set, which can be used to address a wide range of scientific questions. The data analysis procedures are applied to 10,029 Advanced CCD Imaging Spectrometer observations, which produces 363,530 source detections belonging to 217,828 distinct X-ray sources. This number is twice the size of the Chandra Source Catalog (Version 1.1). The catalogs in this paper provide abundant estimates of the detected X-ray source properties, including source positions, counts, colors, fluxes, luminosities, variability statistics, etc. Cross-correlation of these objects with galaxies shows that 17,828 sources are located within the D {sub 25} isophotes of 1110 galaxies, and 7504 sources are located between the D {sub 25} and 2 D {sub 25} isophotes of 910 galaxies. Contamination analysis with the log N –log S relation indicates that 51.3% of objects within 2 D {sub 25} isophotes are truly relevant to galaxies, and the “net” source fraction increases to 58.9%, 67.3%, and 69.1% for sources with luminosities above 10{sup 37}, 10{sup 38}, and 10{sup 39} erg s{sup −1}, respectively. Among the possible scientific uses of this catalog, we discuss the possibility of studying intra-observation variability, inter-observation variability, and supersoft sources (SSSs). About 17,092 detected sources above 10 counts are classified as variable in individual observation with the Kolmogorov–Smirnov (K–S) criterion ( P {sub K–S} < 0.01). There are 99,647 sources observed more than once and 11,843 sources observed 10 times or more, offering us a wealth of data with which to explore the long-term variability. There are 1638 individual objects (∼2350 detections) classified as SSSs. As a quite interesting subclass, detailed studies on X-ray spectra and optical spectroscopic follow-up are needed to

  11. Respiratory source control using a surgical mask: An in vitro study.

    Science.gov (United States)

    Patel, Rajeev B; Skaria, Shaji D; Mansour, Mohamed M; Smaldone, Gerald C

    2016-07-01

    Cough etiquette and respiratory hygiene are forms of source control encouraged to prevent the spread of respiratory infection. The use of surgical masks as a means of source control has not been quantified in terms of reducing exposure to others. We designed an in vitro model using various facepieces to assess their contribution to exposure reduction when worn at the infectious source (Source) relative to facepieces worn for primary (Receiver) protection, and the factors that contribute to each. In a chamber with various airflows, radiolabeled aerosols were exhaled via a ventilated soft-face manikin head using tidal breathing and cough (Source). Another manikin, containing a filter, quantified recipient exposure (Receiver). The natural fit surgical mask, fitted (SecureFit) surgical mask and an N95-class filtering facepiece respirator (commonly known as an "N95 respirator") with and without a Vaseline-seal were tested. With cough, source control (mask or respirator on Source) was statistically superior to mask or unsealed respirator protection on the Receiver (Receiver protection) in all environments. To equal source control during coughing, the N95 respirator must be Vaseline-sealed. During tidal breathing, source control was comparable or superior to mask or respirator protection on the Receiver. Source control via surgical masks may be an important adjunct defense against the spread of respiratory infections. The fit of the mask or respirator, in combination with the airflow patterns in a given setting, are significant contributors to source control efficacy. Future clinical trials should include a surgical mask source control arm to assess the contribution of source control in overall protection against airborne infection.

  12. Control of a Vanadium Redox Battery and supercapacitor using a Three-Level Neutral Point Clamped converter

    Science.gov (United States)

    Etxeberria, A.; Vechiu, I.; Baudoin, S.; Camblong, H.; Kreckelbergh, S.

    2014-02-01

    The increasing use of distributed generators, which are mainly based on renewable sources, can create several issues in the operation of the electric grid. The microgrid is being analysed as a solution to the integration in the grid of the renewable sources at a high penetration level in a controlled way. The storage systems play a vital role in order to keep the energy and power balance of the microgrid. Due to the technical limitations of the currently available storage systems, it is necessary to use more than one storage technology to satisfy the requirements of the microgrid application. This work validates in simulations and experimentally the use of a Three-Level Neutral Point Clamped converter to control the power flow of a hybrid storage system formed by a SuperCapacitor and a Vanadium Redox Battery. The operation of the system is validated in two case studies in the experimental platform installed in ESTIA. The experimental results prove the validity of the proposed system as well as the designed control algorithm. The good agreement among experimental and simulation results also validates the simulation model, that can therefore be used to analyse the operation of the system in different case studies.

  13. Impact of point A asymmetry on local control and survival for low dose-rate (LDR) brachytherapy in cervical cancer.

    Science.gov (United States)

    Opfermann, Krisha J; Wahlquist, Amy; Watkins, John; Kohler, Matthew; Jenrette, Joseph

    2012-03-01

    To evaluate whether Point A asymmetry in low dose-rate (LDR) brachytherapy is associated with local control (LC), disease-free survival (DFS) and/or overall survival (OS). A retrospective analysis of disease control and survival outcomes was conducted for patients who underwent LDR brachytherapy for advanced cervical cancer. Institutional protocol entailed concurrent chemotherapy and whole pelvis radiotherapy (WPRT) over 5 weeks, followed by placement of Fletcher-Suit tandem and colpostat applicators at weeks 6 and 8. Objective Point A doses, 80-85 Gy, were accomplished by placement of Cesium-137 (Cs-137) sources. Cox proportional hazards regression models were used to assess associations between disease control and survival endpoints with variables of interest. The records of 50 patients with FIGO stage IB1-IVA cervical cancer undergoing LDR brachytherapy at our institution were identified. Thirty of these patients had asymmetry > 2.5%, and 11 patients had asymmetry > 5%. At a median survivor follow-up of 20.25 months, 15 patients had experienced disease failure (including 5 cervical/vaginal apex only failures and 2 failures encompassing the local site). Right/left dose asymmetry at Point A was associated with statistically significantly inferior LC (p = 0.035) and inferior DFS (p = 0.011) for patients with mean Point A dose of > 80 Gy. Insufficient evidence existed to conclude an association with OS. LDR brachytherapy may be associated with clinically significant dose asymmetry. The present study demonstrates that patients with Point A asymmetry have a higher risk of failure for DFS and LC.

  14. The Development and Application of Spatiotemporal Metrics for the Characterization of Point Source FFCO2 Emissions and Dispersion

    Science.gov (United States)

    Roten, D.; Hogue, S.; Spell, P.; Marland, E.; Marland, G.

    2017-12-01

    There is an increasing role for high resolution, CO2 emissions inventories across multiple arenas. The breadth of the applicability of high-resolution data is apparent from their use in atmospheric CO2 modeling, their potential for validation of space-based atmospheric CO2 remote-sensing, and the development of climate change policy. This work focuses on increasing our understanding of the uncertainty in these inventories and the implications on their downstream use. The industrial point sources of emissions (power generating stations, cement manufacturing plants, paper mills, etc.) used in the creation of these inventories often have robust emissions characteristics, beyond just their geographic location. Physical parameters of the emission sources such as number of exhaust stacks, stack heights, stack diameters, exhaust temperatures, and exhaust velocities, as well as temporal variability and climatic influences can be important in characterizing emissions. Emissions from large point sources can behave much differently than emissions from areal sources such as automobiles. For many applications geographic location is not an adequate characterization of emissions. This work demonstrates the sensitivities of atmospheric models to the physical parameters of large point sources and provides a methodology for quantifying parameter impacts at multiple locations across the United States. The sensitivities highlight the importance of location and timing and help to highlight potential aspects that can guide efforts to reduce uncertainty in emissions inventories and increase the utility of the models.

  15. Monte Carlo simulation of scatter in non-uniform symmetrical attenuating media for point and distributed sources

    International Nuclear Information System (INIS)

    Henry, L.J.; Rosenthal, M.S.

    1992-01-01

    We report results of scatter simulations for both point and distributed sources of 99m Tc in symmetrical non-uniform attenuating media. The simulations utilized Monte Carlo techniques and were tested against experimental phantoms. Both point and ring sources were used inside a 10.5 cm radius acrylic phantom. Attenuating media consisted of combinations of water, ground beef (to simulate muscle mass), air and bone meal (to simulate bone mass). We estimated/measured energy spectra, detector efficiencies and peak height ratios for all cases. In all cases, the simulated spectra agree with the experimentally measured spectra within 2 SD. Detector efficiencies and peak height ratios also are in agreement. The Monte Carlo code is able to properly model the non-uniform attenuating media used in this project. With verification of the simulations, it is possible to perform initial evaluation studies of scatter correction algorithms by evaluating the mechanisms of action of the correction algorithm on the simulated spectra where the magnitude and sources of scatter are known. (author)

  16. Transformer-based asymmetrical embedded Z-source neutral point clamped inverters with continuous input current and enhanced voltage boost capability

    DEFF Research Database (Denmark)

    Mo, W.; Loh, Poh Chiang; Blaabjerg, Frede

    2013-01-01

    Z-source Neutral Point Clamped (NPC) inverters were introduced to integrate both the advantages of Z-source inverters and NPC inverters. However, traditional Z-source inverters suffer from high voltage stress and chopping input current. This paper proposes six types transformer-based impedance-so......-source NPC inverters which have enhanced voltage boost capability and continuous input current by utilizing of transformer and embedded dc source configuration. Experimental results are presented to verify the theory validation....

  17. Synthetic aperture controlled source electromagnetics

    NARCIS (Netherlands)

    Fan, Y.; Snieder, R.; Slob, E.; Hunziker, J.W.; Singer, J.; Sheiman, J.; Rosenquist, M.

    2010-01-01

    Controlled?source electromagnetics (CSEM) has been used as a de?risking tool in the hydrocarbon exploration industry. Although there have been successful applications of CSEM, this technique is still not widely used in the industry because the limited types of hydrocarbon reservoirs CSEM can detect.

  18. Analysis and research on Maximum Power Point Tracking of Photovoltaic Array with Fuzzy Logic Control and Three-point Weight Comparison Method

    Institute of Scientific and Technical Information of China (English)

    LIN; Kuang-Jang; LIN; Chii-Ruey

    2010-01-01

    The Photovoltaic Array has a best optimal operating point where the array operating can obtain the maximum power.However, the optimal operating point can be compromised by the strength of solar radiation,angle,and by the change of environment and load.Due to the constant changes in these conditions,it has become very difficult to locate the optimal operating point by following a mathematical model.Therefore,this study will focus mostly on the application of Fuzzy Logic Control theory and Three-point Weight Comparison Method in effort to locate the optimal operating point of solar panel and achieve maximum efficiency in power generation. The Three-point Weight Comparison Method is the comparison between the characteristic curves of the voltage of photovoltaic array and output power;it is a rather simple way to track the maximum power.The Fuzzy Logic Control,on the other hand,can be used to solve problems that cannot be effectively dealt with by calculation rules,such as concepts,contemplation, deductive reasoning,and identification.Therefore,this paper uses these two kinds of methods to make simulation successively. The simulation results show that,the Three-point Comparison Method is more effective under the environment with more frequent change of solar radiation;however,the Fuzzy Logic Control has better tacking efficiency under the environment with violent change of solar radiation.

  19. Control of exceptional points in photonic crystal slabs

    DEFF Research Database (Denmark)

    Kaminski, Piotr Marek; Taghizadeh, Alireza; Breinbjerg, Olav

    2017-01-01

    Various ways of controlling the extent of the ring of exceptional points in photonic crystal slabs are investigated. The extent of the ring in photonic crystal slabs is found to vary with the thickness of the slab. This enables recovery of Dirac cones in open, non-Hermitian systems, such as a pho...

  20. Establishing control over nuclear materials and radiation sources in Georgia

    International Nuclear Information System (INIS)

    Basilia, G.

    2010-01-01

    Regulatory control over radiation sources in Georgia was lost after disintegration of the Soviet Union. A number of radiation accidents and illegal events occurred in Georgia. From 1999 Nuclear and Radiation Safety Service of the Ministry of Environmental Protection and Natural Resources is responsible for regulatory control over radiation sources in Georgia. US NRC Regulatory Assistance Program in Georgia Assist the Service in establishing long term regulatory control over sources. Main focuses of US NRC program are country-wide inventory, create National Registry of sources, safe storage of disused sources, upgrade legislation and regulation, implementation licensing and inspection activities

  1. CLS A Fully Open-Source Control System

    CERN Document Server

    Matias, Elder; Johnson, Terry; Tanner, Robby; Wilson, Tony; Wright, Glen; Zhang, Hao

    2005-01-01

    The Canadian Light Source is one of the first major accelerator facility to adopt a fully open source control system. The control system is based on Experimental Physics and Industrial Control System (EPICS) in use at may other facilities. From the outset CLS utilised RTEMS and Linux as the underlying operating systems for real-time control computers, operator interface computers and servers. When communicating with PLC and other intelligent devices CLS has also adopted a policy of using open communications protocols where possible. Combined these strategies have lead to a system that can easily evolve over the life of the facility without being tied to specific hardware or software suppliers. The operational experience over the past few years has indicates the selected architecture is sufficiently robust and reliable.

  2. Impact of Point and Non-point Source Pollution on Coral Reef Ecosystems In Mamala Bay, Oahu, Hawaii based on Water Quality Measurements and Benthic Surveys in 1993-1994 (NODC Accession 0001172)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effects of both point and non-point sources of pollution on coral reef ecosystems in Mamala Bay were studied at three levels of biological organization; the...

  3. Hazard analysis and critical control point (HACCP) for an ultrasound food processing operation.

    Science.gov (United States)

    Chemat, Farid; Hoarau, Nicolas

    2004-05-01

    Emerging technologies, such as ultrasound (US), used for food and drink production often cause hazards for product safety. Classical quality control methods are inadequate to control these hazards. Hazard analysis of critical control points (HACCP) is the most secure and cost-effective method for controlling possible product contamination or cross-contamination, due to physical or chemical hazard during production. The following case study on the application of HACCP to an US food-processing operation demonstrates how the hazards at the critical control points of the process are effectively controlled through the implementation of HACCP.

  4. Guaranteeing Pointing Performance of the SDO Sun-Pointing Controllers in Light of Nonlinear Effects

    Science.gov (United States)

    Starin, Scott R.; Bourkland, Kristin L.

    2007-01-01

    The Solar Dynamics Observatory (SDO) mission is the first Space Weather Research Network mission, part of NASA s Living With a Star program.1 This program seeks to understand the changing Sun and its effects on the Solar System, life, and society. To this end, the SDO spacecraft will carry three Sun-observing instruments to geosynchronous orbit: Helioseismic and Magnetic Imager (HMI), led by Stanford University; Atmospheric Imaging Assembly (AIA), led by Lockheed Martin Space and Astrophysics Laboratory; and Extreme Ultraviolet Variability Experiment (EVE), led by the University of Colorado. Links describing the instruments in detail may be found through the SDO web site.2 The basic mission goals are to observe the Sun for a very high percentage of the 5-year mission (10-year goal) with long stretches of uninterrupted observations and with constant, high-data-rate transmission to a dedicated ground station. These goals guided the design of the spacecraft bus that will carry and service the three-instrument payload. At the time of this publication, the SDO spacecraft bus is well into the integration and testing phase at the NASA Goddard Space Flight Center (GSFC). A three-axis stabilized attitude control system (ACS) is needed both to point at the Sun accurately and to keep the roll about the Sun vector correctly positioned. The ACS has four reaction wheel modes and 2 thruster actuated modes. More details about the ACS in general and the control modes in particular can be found in Refs. [3-6]. All four of SDO s wheel-actuated control modes involve Sun-pointing controllers, as might be expected from such a mission. Science mode, during which most science data is collected, uses specialized guide telescopes to point accurately at the Sun. Inertial mode has two sub-modes, one tracks a Sun-referenced target orientation, and another maintains an absolute (star-referenced) target orientation, that both employ a Kalman filter to process data from a digital Sun sensor and

  5. Anthropogenic Methane Emissions in California's San Joaquin Valley: Characterizing Large Point Source Emitters

    Science.gov (United States)

    Hopkins, F. M.; Duren, R. M.; Miller, C. E.; Aubrey, A. D.; Falk, M.; Holland, L.; Hook, S. J.; Hulley, G. C.; Johnson, W. R.; Kuai, L.; Kuwayama, T.; Lin, J. C.; Thorpe, A. K.; Worden, J. R.; Lauvaux, T.; Jeong, S.; Fischer, M. L.

    2015-12-01

    Methane is an important atmospheric pollutant that contributes to global warming and tropospheric ozone production. Methane mitigation could reduce near term climate change and improve air quality, but is hindered by a lack of knowledge of anthropogenic methane sources. Recent work has shown that methane emissions are not evenly distributed in space, or across emission sources, suggesting that a large fraction of anthropogenic methane comes from a few "super-emitters." We studied the distribution of super-emitters in California's southern San Joaquin Valley, where elevated levels of atmospheric CH4 have also been observed from space. Here, we define super-emitters as methane plumes that could be reliably detected (i.e., plume observed more than once in the same location) under varying wind conditions by airborne thermal infrared remote sensing. The detection limit for this technique was determined to be 4.5 kg CH4 h-1 by a controlled release experiment, corresponding to column methane enhancement at the point of emissions greater than 20% above local background levels. We surveyed a major oil production field, and an area with a high concentration of large dairies using a variety of airborne and ground-based measurements. Repeated airborne surveys (n=4) with the Hyperspectral Thermal Emission Spectrometer revealed 28 persistent methane plumes emanating from oil field infrastructure, including tanks, wells, and processing facilities. The likelihood that a given source type was a super-emitter varied from roughly 1/3 for processing facilities to 1/3000 for oil wells. 11 persistent plumes were detected in the dairy area, and all were associated with wet manure management. The majority (11/14) of manure lagoons in the study area were super-emitters. Comparing to a California methane emissions inventory for the surveyed areas, we estimate that super-emitters comprise a minimum of 9% of inventoried dairy emissions, and 13% of inventoried oil emissions in this region.

  6. The development of control processes supporting source memory discrimination as revealed by event-related potentials.

    Science.gov (United States)

    de Chastelaine, Marianne; Friedman, David; Cycowicz, Yael M

    2007-08-01

    Improvement in source memory performance throughout childhood is thought to be mediated by the development of executive control. As postretrieval control processes may be better time-locked to the recognition response rather than the retrieval cue, the development of processes underlying source memory was investigated with both stimulus- and response-locked event-related potentials (ERPs). These were recorded in children, adolescents, and adults during a recognition memory exclusion task. Green- and red-outlined pictures were studied, but were tested in black outline. The test requirement was to endorse old items shown in one study color ("targets") and to reject new items along with old items shown in the alternative study color ("nontargets"). Source memory improved with age. All age groups retrieved target and nontarget memories as reflected by reliable parietal episodic memory (EM) effects, a stimulus-locked ERP correlate of recollection. Response-locked ERPs to targets and nontargets diverged in all groups prior to the response, although this occurred at an increasingly earlier time point with age. We suggest these findings reflect the implementation of attentional control mechanisms to enhance target memories and facilitate response selection with the greatest and least success, respectively, in adults and children. In adults only, response-locked ERPs revealed an early-onsetting parietal negativity for nontargets, but not for targets. This was suggested to reflect adults' ability to consistently inhibit prepotent target responses for nontargets. The findings support the notion that the development of source memory relies on the maturation of control processes that serve to enhance accurate selection of task-relevant memories.

  7. Optimized Controller Design for a 12-Pulse Voltage Source Converter Based HVDC System

    Science.gov (United States)

    Agarwal, Ruchi; Singh, Sanjeev

    2017-12-01

    The paper proposes an optimized controller design scheme for power quality improvement in 12-pulse voltage source converter based high voltage direct current system. The proposed scheme is hybrid combination of golden section search and successive linear search method. The paper aims at reduction of current sensor and optimization of controller. The voltage and current controller parameters are selected for optimization due to its impact on power quality. The proposed algorithm for controller optimizes the objective function which is composed of current harmonic distortion, power factor, and DC voltage ripples. The detailed designs and modeling of the complete system are discussed and its simulation is carried out in MATLAB-Simulink environment. The obtained results are presented to demonstrate the effectiveness of the proposed scheme under different transient conditions such as load perturbation, non-linear load condition, voltage sag condition, and tapped load fault under one phase open condition at both points-of-common coupling.

  8. Effective regulatory control of radioactive sources

    International Nuclear Information System (INIS)

    Meserve, R.A.

    2001-01-01

    This paper provides an overview of the situation in the USA regarding government control over use of radiation sources, the challenges it faces and the potential paths to their resolution. In the light of the large number of radiation sources in use worldwide, the safety record on balance is remarkably good. But there is still considerable room for improvement. The IAEA has an important role to play, and it is playing it effectively

  9. Wärtsilä turbocharger wash and dew point controller integration

    OpenAIRE

    Perälä, Antti

    2013-01-01

    There are two separate control cabinets used in Wärtsilä marine solutions, Turbocharger Wash Control and the Dew Point Control. The cabinets contain similar PLCs with I/O-cards needed in the system and touch screen for monitoring and controlling purposes. The purpose of the thesis was to find and implement a solution for integration of the control cabinets. The advantages of the integration are savings in material, space in the engine room and amount of work. The aim of the project was to cre...

  10. Acupuncture-Point Stimulation for Postoperative Pain Control: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Xian-Liang Liu

    2015-01-01

    Full Text Available The purpose of this study was to evaluate the effectiveness of Acupuncture-point stimulation (APS in postoperative pain control compared with sham/placebo acupuncture or standard treatments (usual care or no treatment. Only randomized controlled trials (RCTs were included. Meta-analysis results indicated that APS interventions improved VAS scores significantly and also reduced total morphine consumption. No serious APS-related adverse effects (AEs were reported. There is Level I evidence for the effectiveness of body points plaster therapy and Level II evidence for body points electroacupuncture (EA, body points acupressure, body points APS for abdominal surgery patients, auricular points seed embedding, manual auricular acupuncture, and auricular EA. We obtained Level III evidence for body points APS in patients who underwent cardiac surgery and cesarean section and for auricular-point stimulation in patients who underwent abdominal surgery. There is insufficient evidence to conclude that APS is an effective postoperative pain therapy in surgical patients, although the evidence does support the conclusion that APS can reduce analgesic requirements without AEs. The best level of evidence was not adequate in most subgroups. Some limitations of this study may have affected the results, possibly leading to an overestimation of APS effects.

  11. Extraction of Point Source Gamma Signals from Aerial Survey Data Taken over a Las Vegas Nevada, Residential Area

    International Nuclear Information System (INIS)

    Thane J. Hendricks

    2007-01-01

    Detection of point-source gamma signals from aerial measurements is complicated by widely varying terrestrial gamma backgrounds, since these variations frequently resemble signals from point-sources. Spectral stripping techniques have been very useful in separating man-made and natural radiation contributions which exist on Energy Research and Development Administration (ERDA) plant sites and other like facilities. However, these facilities are generally situated in desert areas or otherwise flat terrain with few man-made structures to disturb the natural background. It is of great interest to determine if the stripping technique can be successfully applied in populated areas where numerous man-made disturbances (houses, streets, yards, vehicles, etc.) exist

  12. The rise in the positron fraction. Distance limits on positron point sources from cosmic ray arrival directions and diffuse gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Gebauer, Iris; Bentele, Rosemarie [Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2016-07-01

    The rise in the positron fraction as observed by AMS and previously by PAMELA, cannot be explained by the standard paradigm of cosmic ray transport in which positrons are produced by cosmic-ray-gas interactions in the interstellar medium. Possible explanations are pulsars, which produce energetic electron-positron pairs in their rotating magnetic fields, or the annihilation of dark matter. Here we assume that these positrons originate from a single close-by point source, producing equal amounts of electrons and positrons. The propagation and energy losses of these electrons and positrons are calculated numerically using the DRAGON code, the source properties are optimized to best describe the AMS data. Using the FERMI-LAT limits on a possible dipole anisotropy in electron and positron arrival directions, we put a limit on the minimum distance of such a point source. The energy losses that these energetic electrons and positrons suffer on their way through the galaxy create gamma ray photons through bremsstrahlung and Inverse Compton scattering. Using the measurement of diffuse gamma rays from Fermi-LAT we put a limit on the maximum distance of such a point source. We find that a single electron positron point source powerful enough to explain the locally observed positron fraction must reside between 225 pc and 3.7 kpc distance from the sun and compare to known pulsars.

  13. 47 CFR 90.471 - Points of operation in internal transmitter control systems.

    Science.gov (United States)

    2010-10-01

    ...) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Transmitter Control Internal Transmitter Control Systems § 90.471 Points of operation in internal transmitter control systems. The... licensee for internal communications and transmitter control purposes. Operating positions in internal...

  14. CHANDRA ACIS SURVEY OF X-RAY POINT SOURCES IN NEARBY GALAXIES. II. X-RAY LUMINOSITY FUNCTIONS AND ULTRALUMINOUS X-RAY SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Song; Qiu, Yanli; Liu, Jifeng [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Bregman, Joel N., E-mail: songw@bao.ac.cn, E-mail: jfliu@bao.ac.cn [University of Michigan, Ann Arbor, MI 48109 (United States)

    2016-09-20

    Based on the recently completed Chandra /ACIS survey of X-ray point sources in nearby galaxies, we study the X-ray luminosity functions (XLFs) for X-ray point sources in different types of galaxies and the statistical properties of ultraluminous X-ray sources (ULXs). Uniform procedures are developed to compute the detection threshold, to estimate the foreground/background contamination, and to calculate the XLFs for individual galaxies and groups of galaxies, resulting in an XLF library of 343 galaxies of different types. With the large number of surveyed galaxies, we have studied the XLFs and ULX properties across different host galaxy types, and confirm with good statistics that the XLF slope flattens from lenticular ( α ∼ 1.50 ± 0.07) to elliptical (∼1.21 ± 0.02), to spirals (∼0.80 ± 0.02), to peculiars (∼0.55 ± 0.30), and to irregulars (∼0.26 ± 0.10). The XLF break dividing the neutron star and black hole binaries is also confirmed, albeit at quite different break luminosities for different types of galaxies. A radial dependency is found for ellipticals, with a flatter XLF slope for sources located between D {sub 25} and 2 D {sub 25}, suggesting the XLF slopes in the outer region of early-type galaxies are dominated by low-mass X-ray binaries in globular clusters. This study shows that the ULX rate in early-type galaxies is 0.24 ± 0.05 ULXs per surveyed galaxy, on a 5 σ confidence level. The XLF for ULXs in late-type galaxies extends smoothly until it drops abruptly around 4 × 10{sup 40} erg s{sup −1}, and this break may suggest a mild boundary between the stellar black hole population possibly including 30 M {sub ⊙} black holes with super-Eddington radiation and intermediate mass black holes.

  15. 21 CFR 123.6 - Hazard analysis and Hazard Analysis Critical Control Point (HACCP) plan.

    Science.gov (United States)

    2010-04-01

    ... Control Point (HACCP) plan. 123.6 Section 123.6 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Provisions § 123.6 Hazard analysis and Hazard Analysis Critical Control Point (HACCP) plan. (a) Hazard... fish or fishery product being processed in the absence of those controls. (b) The HACCP plan. Every...

  16. Morphology, chemistry and distribution of neoformed spherulites in agricultural land affected by metallurgical point-source pollution

    NARCIS (Netherlands)

    Leguedois, S.; Oort, van F.; Jongmans, A.G.; Chevalier, P.

    2004-01-01

    Metal distribution patterns in superficial soil horizons of agricultural land affected by metallurgical point-source pollution were studied using optical and electron microscopy, synchrotron radiation and spectroscopy analyses. The site is located in northern France, at the center of a former entry

  17. Identification and quantification of point sources of surface water contamination in fruit culture in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Beltman, W.H.J.; Werd, de H.A.E.; Zande, van de J.C.

    2008-01-01

    Measurements of pesticide concentrations in surface water by the water boards show that they have decreased less than was expected from model calculations. Possibly, the implementation of spray drift reducing techniques is overestimated in the model calculation. The impact of point sources is

  18. Estimation of Methane Emissions from Municipal Solid Waste Landfills in China Based on Point Emission Sources

    Directory of Open Access Journals (Sweden)

    Cai Bo-Feng

    2014-01-01

    Citation: Cai, B.-F., Liu, J.-G., Gao, Q.-X., et al., 2014. Estimation of methane emissions from municipal solid waste landfills in China based on point emission sources. Adv. Clim. Change Res. 5(2, doi: 10.3724/SP.J.1248.2014.081.

  19. VizieR Online Data Catalog: ChaMP X-ray point source catalog (Kim+, 2007)

    Science.gov (United States)

    Kim, M.; Kim, D.-W.; Wilkes, B. J.; Green, P. J.; Kim, E.; Anderson, C. S.; Barkhouse, W. A.; Evans, N. R.; Ivezic, Z.; Karovska, M.; Kashyap, V. L.; Lee, M. G.; Maksym, P.; Mossman, A. E.; Silverman, J. D.; Tananbaum, H. D.

    2009-01-01

    We present the Chandra Multiwavelength Project (ChaMP) X-ray point source catalog with ~6800 X-ray sources detected in 149 Chandra observations covering ~10deg2. The full ChaMP catalog sample is 7 times larger than the initial published ChaMP catalog. The exposure time of the fields in our sample ranges from 0.9 to 124ks, corresponding to a deepest X-ray flux limit of f0.5-8.0=9x10-16ergs/cm2/s. The ChaMP X-ray data have been uniformly reduced and analyzed with ChaMP-specific pipelines and then carefully validated by visual inspection. The ChaMP catalog includes X-ray photometric data in eight different energy bands as well as X-ray spectral hardness ratios and colors. To best utilize the ChaMP catalog, we also present the source reliability, detection probability, and positional uncertainty. (10 data files).

  20. Control for nuclear thermionic power source

    International Nuclear Information System (INIS)

    Fletcher, J.C.; Sawyer, C.D.

    1978-01-01

    A control for a power source is described which includes nuclear fuel interspersed with thermionic converters, including a power regulator that maintains a substantially constant output voltage to a variable load, and a control circuit that drives a neutron flux regulator in accordance with the current supplied to the power regulator and the neutron flux density in the region of the converters. The control circuit generates a control signal which is the difference between the neutron flux density and a linear fucntion of the current, and which drives the neutron regulator in a direction to decrease or increase the neutron flux according to the polarity of the control signal

  1. Carbon dioxide capture and separation techniques for advanced power generation point sources

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H.W.; Luebke, D.R.; Morsi, B.I.; Heintz, Y.J.; Jones, K.L.; Ilconich, J.B.

    2006-09-01

    The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (postcombustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle – IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Fabrication techniques and mechanistic studies for hybrid membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic silanes incorporated into an alumina support or ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. An overview of two novel techniques is presented along with a research progress status of each technology.

  2. NONPOINT SOURCES AND WATER QUALITY TRADING

    Science.gov (United States)

    Management of nonpoint sources (NPS) of nutrients may reduce discharge levels more cost effectively than can additional controls on point sources (PS); water quality trading (WQT), where a PS buys nutrient or sediment reductions from an NPS, may be an alternative means for the PS...

  3. Emissions of perfluorinated alkylated substances (PFAS) from point sources--identification of relevant branches.

    Science.gov (United States)

    Clara, M; Scheffknecht, C; Scharf, S; Weiss, S; Gans, O

    2008-01-01

    Effluents of wastewater treatment plants are relevant point sources for the emission of hazardous xenobiotic substances to the aquatic environment. One group of substances, which recently entered scientific and political discussions, is the group of the perfluorinated alkylated substances (PFAS). The most studied compounds from this group are perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS), which are the most important degradation products of PFAS. These two substances are known to be persistent, bioaccumulative and toxic (PBT). In the present study, eleven PFAS were investigated in effluents of municipal wastewater treatment plants (WWTP) and in industrial wastewaters. PFOS and PFOA proved to be the dominant compounds in all sampled wastewaters. Concentrations of up to 340 ng/L of PFOS and up to 220 ng/L of PFOA were observed. Besides these two compounds, perfluorohexanoic acid (PFHxA) was also present in nearly all effluents and maximum concentrations of up to 280 ng/L were measured. Only N-ethylperfluorooctane sulphonamide (N-EtPFOSA) and its degradation/metabolisation product perfluorooctane sulphonamide (PFOSA) were either detected below the limit of quantification or were not even detected at all. Beside the effluents of the municipal WWTPs, nine industrial wastewaters from six different industrial branches were also investigated. Significantly, the highest emissions or PFOS were observed from metal industry whereas paper industry showed the highest PFOA emission. Several PFAS, especially perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorododecanoic acid (PFDoA) and PFOS are predominantly emitted from industrial sources, with concentrations being a factor of 10 higher than those observed in the municipal WWTP effluents. Perfluorodecane sulphonate (PFDS), N-Et-PFOSA and PFOSA were not detected in any of the sampled industrial point sources. (c) IWA Publishing 2008.

  4. Column Number Density Expressions Through M = 0 and M = 1 Point Source Plumes Along Any Straight Path

    Science.gov (United States)

    Woronowicz, Michael

    2016-01-01

    Analytical expressions for column number density (CND) are developed for optical line of sight paths through a variety of steady free molecule point source models including directionally-constrained effusion (Mach number M = 0) and flow from a sonic orifice (M = 1). Sonic orifice solutions are approximate, developed using a fair simulacrum fitted to the free molecule solution. Expressions are also developed for a spherically-symmetric thermal expansion (M = 0). CND solutions are found for the most general paths relative to these sources and briefly explored. It is determined that the maximum CND from a distant location through directed effusion and sonic orifice cases occurs along the path parallel to the source plane that intersects the plume axis. For the effusive case this value is exactly twice the CND found along the ray originating from that point of intersection and extending to infinity along the plume's axis. For sonic plumes this ratio is reduced to about 4/3. For high Mach number cases the maximum CND will be found along the axial centerline path. Keywords: column number density, plume flows, outgassing, free molecule flow.

  5. Maximum Power Point Tracking Using Sliding Mode Control for Photovoltaic Array

    Directory of Open Access Journals (Sweden)

    J. Ghazanfari

    2013-09-01

    Full Text Available In this paper, a robust Maximum Power Point Tracking (MPPT for PV array has been proposed using sliding mode control by defining a new formulation for sliding surface which is based on increment conductance (INC method. The stability and robustness of the proposed controller are investigated to load variations and environment changes. Three different types of DC-DC converter are used in Maximum Power Point (MPP system and the results obtained are given. The simulation results confirm the effectiveness of the proposed method in the presence of load variations and environment changes for different types of DC-DC converter topologies.

  6. Low energy electron point source microscopy: beyond imaging

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Andre; Goelzhaeuser, Armin [Physics of Supramolecular Systems and Surfaces, University of Bielefeld, Postfach 100131, 33501 Bielefeld (Germany)

    2010-09-01

    Low energy electron point source (LEEPS) microscopy has the capability to record in-line holograms at very high magnifications with a fairly simple set-up. After the holograms are numerically reconstructed, structural features with the size of about 2 nm can be resolved. The achievement of an even higher resolution has been predicted. However, a number of obstacles are known to impede the realization of this goal, for example the presence of electric fields around the imaged object, electrostatic charging or radiation induced processes. This topical review gives an overview of the achievements as well as the difficulties in the efforts to shift the resolution limit of LEEPS microscopy towards the atomic level. A special emphasis is laid on the high sensitivity of low energy electrons to electrical fields, which limits the structural determination of the imaged objects. On the other hand, the investigation of the electrical field around objects of known structure is very useful for other tasks and LEEPS microscopy can be extended beyond the task of imaging. The determination of the electrical resistance of individual nanowires can be achieved by a proper analysis of the corresponding LEEPS micrographs. This conductivity imaging may be a very useful application for LEEPS microscopes. (topical review)

  7. CLOSED LOOP CONTROL OF EMBEDDED Z-SOURCE INVERTER WITH FUZZY CONTROLLER FOR SOLAR PV APPLICATIONS

    OpenAIRE

    Midde Mahesh*, K. Leleedhar Rao

    2017-01-01

    This paper proposes the use of Embedded Z –source inverter system with fuzzy controller for Solar Photo Voltaic (PV) applications with adjustable speed drives. Closed loop operation FUZZY control strategies of EZSI system are proposed. EZSI produces the same voltage gain as Z-source inverter (ZSI) but due to the DC sources embedded within the X- shaped impedance network, it has the added advantage of inherent source filtering capability and also reduced capacitor sizing. This can be achiev...

  8. Control of radioisotopes and radiation sources in Indonesia

    International Nuclear Information System (INIS)

    Ridwan, M.

    2001-01-01

    Radioisotopes and radiation sources are extensively used in Indonesia in medicine, industry, mining, agriculture and research. These materials are controlled by the regulatory authority, according to established legal procedures. The Nuclear Energy Control Board of Indonesia (BAPETEN), which was established in 1998 through the Nuclear Energy Act No. 10/1997, is entrusted with the control of any application of nuclear energy, including the application of radioisotopes and radiation sources, through regulation, licensing and inspection. The control is aimed to assure welfare, security and peace, the safety and health of workers and the public, and environmental protection. The number of licences issued to date is around 2400, consisting of 1600 licences for radioisotopes and radiation sources used in hospitals, 347 in radiography, 256 in industry, 53 in mining, and the rest in many other areas such as research and agriculture. A licence can cover one or more radioisotopes or radiation sources, depending on the location of the user institution. These radioisotopes and radiation sources are Co-60, Cs-137, Ir-192, Ra-226, Am-241, Sr-90, Kr-85, Pm-147, linear accelerator and X-ray, and short half-life radioisotopes such as I-125, I-131 and Tc-99m. There are 10 LINACs, 27 X-ray medicines, 61 radioisotope devices for Co-60 and Cs-137, and 10 mHDR Ir-192 for therapeutic purposes currently used in Indonesia and some Ra-226 in storage. Any activity related to the application of nuclear energy is required to be conducted in a manner which observes safety and security. According to the legal requirements, each user has to employ at least one radiation safety officer. To improve the control of the application of radiation sources and radioactive material in the country, BAPETEN introduced some new approaches to the users, including regular dialogues with radiation safety officers and the management of the users, requalification for radiation protection officers twice in five

  9. Orphan sources: Consequences, regaining control and learning the lessons

    International Nuclear Information System (INIS)

    Croft, J.R.

    2001-01-01

    The safety and security record of technologies that use radiation sources is adequate in most cases, but on occasions there has been a lack of appropriate controls or circumvention of those that exist, leading to radiological accidents. Particular concern rise those radiation sources that have become orphans i.e. sources that were never subject to regulatory control, or were abandoned, lost or misplaced, stolen, or removed without authorisation. These sources are likely to be found in the public domain; examples include sources that used in radiotherapy units which have been unintentionally sold as scrap metal and melted thereafter, or which have been found by unsuspecting individuals or stolen, causing serious radiation exposure of people and contamination of the human habitat

  10. The point of no return: A fundamental limit on the ability to control thought and action.

    Science.gov (United States)

    Logan, Gordon D

    2015-01-01

    Bartlett (1958. Thinking. New York: Basic Books) described the point of no return as a point of irrevocable commitment to action, which was preceded by a period of gradually increasing commitment. As such, the point of no return reflects a fundamental limit on the ability to control thought and action. I review the literature on the point of no return, taking three perspectives. First, I consider the point of no return from the perspective of the controlled act, as a locus in the architecture and anatomy of the underlying processes. I review experiments from the stop-signal paradigm that suggest that the point of no return is located late in the response system. Then I consider the point of no return from the perspective of the act of control that tries to change the controlled act before it becomes irrevocable. From this perspective, the point of no return is a point in time that provides enough "lead time" for the act of control to take effect. I review experiments that measure the response time to the stop signal as the lead time required for response inhibition in the stop-signal paradigm. Finally, I consider the point of no return in hierarchically controlled tasks, in which there may be many points of no return at different levels of the hierarchy. I review experiments on skilled typing that suggest different points of no return for the commands that determine what is typed and the countermands that inhibit typing, with increasing commitment to action the lower the level in the hierarchy. I end by considering the point of no return in perception and thought as well as action.

  11. The regulatory control of radioactive sources in Argentina

    International Nuclear Information System (INIS)

    Rojkind, Roberto Hector

    1997-01-01

    Argentina has been conducting nuclear activities for more than forty years, and as early as in 1956 established a Regulatory Authority. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations had been set in Argentina, before the accident in Goiania. The conclusions drawn from that accident encouraged in Argentina the improvement of some regulatory procedures and helped to enhance the quality of the regulatory process. Therefore, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain improved. Some lessons learned in Argentina from the accident in Goiania and the main characteristics of an effective enforcement program helpful to prevent radiological accidents in industrial, medical, research and teaching uses of radioactive sources are presented. (author)

  12. Normalized Point Source Sensitivity for Off-Axis Optical Performance Evaluation of the Thirty Meter Telescope

    Science.gov (United States)

    Seo, Byoung-Joon; Nissly, Carl; Troy, Mitchell; Angeli, George

    2010-01-01

    The Normalized Point Source Sensitivity (PSSN) has previously been defined and analyzed as an On-Axis seeing-limited telescope performance metric. In this paper, we expand the scope of the PSSN definition to include Off-Axis field of view (FoV) points and apply this generalized metric for performance evaluation of the Thirty Meter Telescope (TMT). We first propose various possible choices for the PSSN definition and select one as our baseline. We show that our baseline metric has useful properties including the multiplicative feature even when considering Off-Axis FoV points, which has proven to be useful for optimizing the telescope error budget. Various TMT optical errors are considered for the performance evaluation including segment alignment and phasing, segment surface figures, temperature, and gravity, whose On-Axis PSSN values have previously been published by our group.

  13. Remotely controlled repair at Douglas Point

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The Douglas Point nuclear generating station, completed in 1966, was Canada's first venture in commercial nuclear power. The discovery, 11 years later, of two perforations in auxiliary piping in a high radiation area led Atomic Energy of Canada Ltd and Ontario Hydro to develop new approaches to remotely controlled repair that will have much wider applications. Eddy current and ultrasonic testing were used to determine the pattern and extent of wear in a pipe encircled by a U-bolt, without first removing the U-bolt. Progress was monitored using remote TV cameras. Welding tools were designed and fabricated for the repairs, and a manipulator was also designed to transport the tool into its place of work. (author)

  14. International conference on the safety and security of radioactive sources: Towards a global system for the continuous control of sources throughout their life cycle. Contributed papers

    International Nuclear Information System (INIS)

    2005-01-01

    The objective of the conference is to promote a wide exchange of information on key issues relating to the safety and security of radioactive sources, including: drawing up an inventory; finding a solution without delay to situations resulting from past activities; preparing for the future by defining a global cooperative approach to the continuous control of radioactive sources during their life cycle. It is expected that the conference will foster a better understanding of the risks posed by these sources from the point of view of radiation safety and the threat associated with some of them in the event of malevolent use, and will help in finding ways of reducing the likelihood of the occurrence of a radiological incident or accident, or of a malevolent act. It is also expected to identify the preparedness and response measures that are necessary and to facilitate a common understanding on the feasibility of creating a sustainable global system for ensuring the safety and security of radioactive sources

  15. International conference on the safety and security of radioactive sources: Towards a global system for the continuous control of sources throughout their life cycle. Contributed papers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The objective of the conference is to promote a wide exchange of information on key issues relating to the safety and security of radioactive sources, including: drawing up an inventory; finding a solution without delay to situations resulting from past activities; preparing for the future by defining a global cooperative approach to the continuous control of radioactive sources during their life cycle. It is expected that the conference will foster a better understanding of the risks posed by these sources from the point of view of radiation safety and the threat associated with some of them in the event of malevolent use, and will help in finding ways of reducing the likelihood of the occurrence of a radiological incident or accident, or of a malevolent act. It is also expected to identify the preparedness and response measures that are necessary and to facilitate a common understanding on the feasibility of creating a sustainable global system for ensuring the safety and security of radioactive sources.

  16. Controlling organic chemical hazards in food manufacturing: a hazard analysis critical control points (HACCP) approach.

    Science.gov (United States)

    Ropkins, K; Beck, A J

    2002-08-01

    Hazard analysis by critical control points (HACCP) is a systematic approach to the identification, assessment and control of hazards. Effective HACCP requires the consideration of all hazards, i.e., chemical, microbiological and physical. However, to-date most 'in-place' HACCP procedures have tended to focus on the control of microbiological and physical food hazards. In general, the chemical component of HACCP procedures is either ignored or limited to applied chemicals, e.g., food additives and pesticides. In this paper we discuss the application of HACCP to a broader range of chemical hazards, using organic chemical contaminants as examples, and the problems that are likely to arise in the food manufacturing sector. Chemical HACCP procedures are likely to result in many of the advantages previously identified for microbiological HACCP procedures: more effective, efficient and economical than conventional end-point-testing methods. However, the high costs of analytical monitoring of chemical contaminants and a limited understanding of formulation and process optimisation as means of controlling chemical contamination of foods are likely to prevent chemical HACCP becoming as effective as microbiological HACCP.

  17. Point-source reconstruction with a sparse light-sensor array for optical TPC readout

    International Nuclear Information System (INIS)

    Rutter, G; Richards, M; Bennieston, A J; Ramachers, Y A

    2011-01-01

    A reconstruction technique for sparse array optical signal readout is introduced and applied to the generic challenge of large-area readout of a large number of point light sources. This challenge finds a prominent example in future, large volume neutrino detector studies based on liquid argon. It is concluded that the sparse array option may be ruled out for reasons of required number of channels when compared to a benchmark derived from charge readout on wire-planes. Smaller-scale detectors, however, could benefit from this technology.

  18. The Treatment Train approach to reducing non-point source pollution from agriculture

    Science.gov (United States)

    Barber, N.; Reaney, S. M.; Barker, P. A.; Benskin, C.; Burke, S.; Cleasby, W.; Haygarth, P.; Jonczyk, J. C.; Owen, G. J.; Snell, M. A.; Surridge, B.; Quinn, P. F.

    2016-12-01

    An experimental approach has been applied to an agricultural catchment in NW England, where non-point pollution adversely affects freshwater ecology. The aim of the work (as part of the River Eden Demonstration Test Catchment project) is to develop techniques to manage agricultural runoff whilst maintaining food production. The approach used is the Treatment Train (TT), which applies multiple connected mitigation options that control nutrient and fine sediment pollution at source, and address polluted runoff pathways at increasing spatial scale. The principal agricultural practices in the study sub-catchment (1.5 km2) are dairy and stock production. Farm yards can act as significant pollution sources by housing large numbers of animals; these areas are addressed initially with infrastructure improvements e.g. clean/dirty water separation and upgraded waste storage. In-stream high resolution monitoring of hydrology and water quality parameters showed high-discharge events to account for the majority of pollutant exports ( 80% total phosphorus; 95% fine sediment), and primary transfer routes to be surface and shallow sub-surface flow pathways, including drains. To manage these pathways and reduce hydrological connectivity, a series of mitigation features were constructed to intercept and temporarily store runoff. Farm tracks, field drains, first order ditches and overland flow pathways were all targeted. The efficacy of the mitigation features has been monitored at event and annual scale, using inflow-outflow sampling and sediment/nutrient accumulation measurements, respectively. Data presented here show varied but positive results in terms of reducing acute and chronic sediment and nutrient losses. An aerial fly-through of the catchment is used to demonstrate how the TT has been applied to a fully-functioning agricultural landscape. The elevated perspective provides a better understanding of the spatial arrangement of mitigation features, and how they can be

  19. Source of vacuum electromagnetic zero-point energy and Dirac's large numbers hypothesis

    International Nuclear Information System (INIS)

    Simaciu, I.; Dumitrescu, G.

    1993-01-01

    The stochastic electrodynamics states that zero-point fluctuation of the vacuum (ZPF) is an electromagnetic zero-point radiation with spectral density ρ(ω)=ℎω 3 / 2π 2 C 3 . Protons, free electrons and atoms are sources for this radiation. Each of them absorbs and emits energy by interacting with ZPF. At equilibrium ZPF radiation is scattered by dipoles.Scattered radiation spectral density is ρ(ω,r) ρ(ω).c.σ(ω) / 4πr 2 . Radiation of dipole spectral density of Universe is ρ ∫ 0 R nρ(ω,r)4πr 2 dr. But if σ atom P e σ=σ T then ρ ρ(ω)σ T R.n. Moreover if ρ=ρ(ω) then σ T Rn = 1. With R = G M/c 2 and σ T ≅(e 2 /m e c 2 ) 2 ∝ r e 2 then σ T .Rn 1 is equivalent to R/r e = e 2 /Gm p m e i.e. the cosmological coincidence discussed in the context of Dirac's large-numbers hypothesis. (Author)

  20. Maximum-power-point tracking control of solar heating system

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

    The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

  1. Effective Regulatory Control of Radioactive Sources in Taiwan

    International Nuclear Information System (INIS)

    Liu, W.; Yuan, C.; Fan, S.; Su, S.

    2004-01-01

    Since the incident of radioactively contaminated buildings first surfaced in Taiwan in 1992, efforts have been made by AEC (Atomic Energy Council) of Taiwan to prevent recurrence of similar incidents involving radioactive materials and to achieve effective regulatory control over radioactive sources. The most important milestone is when AEC began to enforce IRPA he Ionizing Radiation Protection Act with the promulgation of 18 relevant regulations on Feb. 1, 2003. In order to enhance accountability of radioactive material and equipment capable of producing ionizing radiation, AEC develops and begins implementing a RPCS Radiation Protection Control System which is a powerful tool in controlling radiation safety and security. In addition, AEC develops a monthly registration program via internet, an o n-line reporting system f or owners/operators of radioactive sources, to improve monitoring of sealed sources (in-use and not-in-use). The registration requirement applies to 469 licensees possessing about 3,000 sealed sources in Taiwan. Because of the threat of orphan sources, AEC has made great efforts in preventing their contamination of construction steel material by establishing and enforcing the RPMMPIRCB Regulation for Preventive Measures and Management Plans for Incident of Radioactively Contaminated Buildings. To comply with this regulation, all 19 of Taiwan's steel factories with melting furnace have installed portal-type radiation detection system to monitor incoming scrap metal. (Author)

  2. Modeling the effects of integrating larval habitat source reduction and insecticide treated nets for malaria control.

    Directory of Open Access Journals (Sweden)

    Laith Yakob

    Full Text Available Integrated vector management for malaria control has received a lot of recent interest. Attacking multiple points in the transmission cycle is hoped to act synergistically and improve upon current single-tool interventions based on the use of insecticide-treated bed nets (ITNs. In the present study, we theoretically examined the application of larval habitat source reduction with ITNs in reducing malaria transmission. We selected this type of environmental management to complement ITNs because of a potential secondary mode of action that both control strategies share. In addition to increasing vector mortality, ITNs reduce the rate at which female mosquitoes locate human hosts for blood feeding, thereby extending their gonotrophic cycle. Similarly, while reducing adult vector emergence and abundance, source reduction of larval habitats may prolong the cycle duration by extending delays in locating oviposition sites. We found, however, that source reduction of larval habitats only operates through this secondary mode of action when habitat density is below a critical threshold. Hence, we illustrate how this strategy becomes increasingly effective when larval habitats are limited. We also demonstrate that habitat source reduction is better suited to human populations of higher density and in the presence of insecticide resistance or when the insecticidal properties of ITNs are depleted.

  3. A frequency controlled LCL - T resonant converter for H- ion source

    International Nuclear Information System (INIS)

    Gauttam, V.K.; Kasliwal, A.; Banwari, R.; Pandit, T.G.; Thakurta, A.C.

    2013-01-01

    An H - ion source is being developed at Raja Ramanna Centre for Advanced Technology, Indore. An LCL-T resonant power converter with variable frequency control is proposed which is utilized to develop a -20 kV/100 mA high voltage (HV) power supply for extraction of H - ions. The LCL-T resonant topology offers many advantages like gainful utilization of the transformer parasitics as a part of resonant network and low circulating current. The power converter is operated with variable frequency control and above resonance to get well known zero-voltage switching (ZVS) advantages for full bridge semiconductor switches in full load range. The converter energizes the symmetrical Cockcroft-Walton (CW) based HV generator to achieve required high voltage. The CW circuit is an attractive solution for HV generation since it has features like low stored energy and low output ripple. The HV power supply is operated in constant current (CC) mode with closed loop control and soft start of the power supply is achieved by sweeping the switching frequency from 40 kHz to defined operating point. Design parameters, simulation results and experimental results of the power converter are presented in this paper. (author)

  4. The regulatory control of radioactive sources in Argentina

    International Nuclear Information System (INIS)

    Rojkind, R.H.

    1998-01-01

    Argentina has been conducting nuclear activities for more than forty years, and had established a Regulatory Authority as early as in 1956. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations were in force in Argentina before the accident in Goiania. The conclusions drawn from the Goiania accident encouraged the Argentine authorities to improve some regulatory procedures and helped to enhance the quality of the regulatory process. As a result, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain have improved. Lessons learned in Argentina from the accident in Goiania are presented as well as the main characteristics of an effective enforcement programme to prevent radiological accidents when radioactive sources are used for industrial, medical, research and teaching purposes. (author)

  5. Point, surface and volumetric heat sources in the thermal modelling of selective laser melting

    Science.gov (United States)

    Yang, Yabin; Ayas, Can

    2017-10-01

    Selective laser melting (SLM) is a powder based additive manufacturing technique suitable for producing high precision metal parts. However, distortions and residual stresses within products arise during SLM because of the high temperature gradients created by the laser heating. Residual stresses limit the load resistance of the product and may even lead to fracture during the built process. It is therefore of paramount importance to predict the level of part distortion and residual stress as a function of SLM process parameters which requires a reliable thermal modelling of the SLM process. Consequently, a key question arises which is how to describe the laser source appropriately. Reasonable simplification of the laser representation is crucial for the computational efficiency of the thermal model of the SLM process. In this paper, first a semi-analytical thermal modelling approach is described. Subsequently, the laser heating is modelled using point, surface and volumetric sources, in order to compare the influence of different laser source geometries on the thermal history prediction of the thermal model. The present work provides guidelines on appropriate representation of the laser source in the thermal modelling of the SLM process.

  6. The 1.4-2.7 micron spectrum of the point source at the galactic center

    Science.gov (United States)

    Treffers, R. R.; Fink, U.; Larson, H. P.; Gautier, T. N., III

    1976-01-01

    The spectrum of the 2-micron point source at the galactic center is presented over the range from 1.4 to 2.7 microns. The two-level-transition CO band heads are seen near 2.3 microns, confirming that the radiation from this source is due to a cool supergiant star. The heliocentric radial velocity is found to be - 173 (+ or -90) km/s and is consistent with the star being in orbit about a dense galactic nucleus. No evidence is found for Brackett-gamma emission, and no interstellar absorption features are seen. Upper limits for the column densities of interstellar H2, CH4, CO, and NH3 are derived.

  7. Nutrient Losses from Non-Point Sources or from Unidentified Point Sources? Application Examples of the Smartphone Based Nitrate App.

    Science.gov (United States)

    Rozemeijer, J.; Ekkelenkamp, R.; van der Zaan, B.

    2017-12-01

    In 2016 Deltares launched the free to use Nitrate App which accurately reads and interprets nitrate test strips. The app directly displays the measured concentration and gives the option to share the result. Shared results are visualised in map functionality within the app and online. Since its introduction we've been seeing an increasing number of nitrate app applications. In this presentation we show some unanticipated types of application. The Nitrate App was originally intended to enable farmers to measure nitrate concentrations on their own farms. This may encourage farmers to talk to specialists about the right nutrient best management practices (BMP's) for their farm. Several groups of farmers have recently started to apply the Nitrate App and to discuss their results with each other and with the authorities. Nitrate concentration routings in catchments have proven to be another useful application. Within a day a person can generate a catchment scale nitrate concentration map identifying nitrate loss hotspots. In several routings in agricultural catchments clear point sources were found, for example at small scale manure processing plants. These routings proved that the Nitrate App can help water managers to target conservation practices more accurately to areas with the highest nitrate concentrations and loads. Other current applications are the screening of domestic water wells in California, the collection of extra measurements (also pH and NH4) in the National Monitoring Network for the Evaluation of the Manure Policy in the Netherlands, and several educational initiatives in cooperation with schools and universities.

  8. Spark-safe power source

    Energy Technology Data Exchange (ETDEWEB)

    Mester, I M; Konushkin, N A; Nevozinskiy, A K; Rubinshteyn, B Sh; Serov, V I; Vasnev, M A

    1981-01-01

    A shortcoming of the known power sources is their low reliability. The purpose of the invention is to improve the reliability of the device. This is achieved because the spark-safe power source is equipped with a by-passing transistor and potentiometer, and also a generator of control interruptions in the circuit, an I-element, first separating transformer, control block, second separating transformer whose secondary winding has a relay winding whose contacts are connected to the load circuit are connected in series. The generator of control separations of the circuit is connected to the base of the by-passing transistor and to the power source outlet, the potentiometer is connected in series to the main thyristor. The middle point of the potentiometer is connected to the second inlet of the I-element.

  9. A Biomechanical Model of Single-joint Arm Movement Control Based on the Equilibrium Point Hypothesis

    OpenAIRE

    Masataka, SUZUKI; Yoshihiko, YAMAZAKI; Yumiko, TANIGUCHI; Department of Psychology, Kinjo Gakuin University; Department of Health and Physical Education, Nagoya Institute of Technology; College of Human Life and Environment, Kinjo Gakuin University

    2003-01-01

    SUZUKI,M., YAMAZAKI,Y. and TANIGUCHI,Y., A Biomechanical Model of Single-joint Arm Movement Control Based on the Equilibrium Point Hypothesis. Adv. Exerc. Sports Physiol., Vol.9, No.1 pp.7-25, 2003. According to the equilibrium point hypothesis of motor control, control action of muscles is not explicitly computed, but rather arises as a consequence of interaction among moving equilibrium point, reflex feedback and muscle mechanical properties. This approach is attractive as it obviates the n...

  10. Regulatory control of radiation sources in Slovakia

    International Nuclear Information System (INIS)

    Auxtova, L.

    2001-01-01

    In Slovakia, there are two regulatory authorities. Regulatory control of the utilization of nuclear energy, based on the Slovak National Council's law No. 130/1998 on the peaceful uses of nuclear energy, is exercised by the Nuclear Regulatory Authority of the Slovak Republic. The second regulatory authority - the Ministry of Health - is empowered by law No. 72/1994 on the protection of human health to license radiation sources and is responsible for radiation protection supervision (there are nearly 3000 establishments with sealed sources, radiation generators and unsealed sources in Slovakia). Pursuant to a new radiation protection regulation based on international standards, radiation sources are to be categorized in six classes according to the associated exposure and contamination hazards. A national strategy for improving the safety of radiation sources over their life-cycle and for the management of disused and orphan sources is being prepared for governmental approval. (author)

  11. Setting the agenda for a healthy retail environment: content analysis of US newspaper coverage of tobacco control policies affecting the point of sale, 2007-2014.

    Science.gov (United States)

    Myers, Allison E; Southwell, Brian G; Ribisl, Kurt M; Moreland-Russell, Sarah; Lytle, Leslie A

    2017-07-01

    Tobacco control policies affecting the point of sale (POS) are an emerging intervention, yet POS-related news media content has not been studied. We describe news coverage of POS tobacco control efforts and assess relationships between article characteristics, including policy domains, frames, sources, localisation and evidence present, and slant towards tobacco control efforts. High circulation state (n=268) and national (n=5) newspapers comprised the sampling frame. We retrieved 917 relevant POS-focused articles in newspapers from 1 January 2007 to 31 December 2014. 5 raters screened and coded articles, 10% of articles were double coded, and mean inter-rater reliability (IRR) was 0.74. POS coverage emphasised tobacco retailer licensing (49.1% of articles) and the most common frame present was regulation (71.3%). Government officials (52.3%), followed by tobacco retailers (39.6%), were the most frequent sources. Half of articles (51.3%) had a mixed, neutral or antitobacco control slant. Articles presenting a health frame, a greater number of protobacco control sources, and statistical evidence were significantly more likely to also have a protobacco control slant. Articles presenting a political/rights or regulation frame, a greater number of antitobacco control sources, or government, tobacco industry, tobacco retailers, or tobacco users as sources were significantly less likely to also have a protobacco control slant. Stories that feature procontrol sources, research evidence and a health frame also tend to support tobacco control objectives. Future research should investigate how to use data, stories and localisation to encourage a protobacco control slant, and should test relationships between content characteristics and policy progression. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  12. Regulated control of practices and radiation sources

    International Nuclear Information System (INIS)

    1992-01-01

    Excepting the radiation caused by the natural background radiation, the Executive Secretariat for Nuclear Affairs (SEAN) does not authorize any source no practice within the national territory that may imply exposure of a person to ionizing radiation unless this use is ruled. This document establishes the basic criteria to set up such system as well as to exclude or exempt practices and sources from this regulated control

  13. Maintenance of equilibrium point control during an unexpectedly loaded rapid limb movement.

    Science.gov (United States)

    Simmons, R W; Richardson, C

    1984-06-08

    Two experiments investigated whether the equilibrium point hypothesis or the mass-spring model of motor control subserves positioning accuracy during spring loaded, rapid, bi-articulated movement. For intact preparations, the equilibrium point hypothesis predicts response accuracy to be determined by a mixture of afferent and efferent information, whereas the mass-spring model predicts positioning to be under a direct control system. Subjects completed a series of load-resisted training trials to a spatial target. The magnitude of a sustained spring load was unexpectedly increased on selected trials. Results indicated positioning accuracy and applied force varied with increases in load, which suggests that the original efferent commands are modified by afferent information during the movement as predicted by the equilibrium point hypothesis.

  14. Point X-ray sources in the SNR G 315.4-2.30 (MSH 14-63, RCW 86)

    Science.gov (United States)

    Gvaramadze, V. V.; Vikhlinin, A. A.

    2003-04-01

    We report the results of a search for a point X-ray source (stellar remnant) in the southwest protrusion of the supernova remnant G 315.4-2.30 (MSH 14-63, RCW 86) using the archival data of the Chandra X-ray Observatory. The search was motivated by a hypothesis that G 315.4-2.30 is the result of an off-centered cavity supernova explosion of a moving massive star, which ended its evolution just near the edge of the main-sequence wind-driven bubble. This hypothesis implies that the southwest protrusion in G 315.4-2.30 is the remainder of a pre-existing bow shock-like structure created by the interaction of the supernova progenitor's wind with the interstellar medium and that the actual location of the supernova blast center is near the center of this hemispherical structure. We have discovered two point X-ray sources in the ``proper" place. One of the sources has an optical counterpart with the photographic magnitude 13.38+/-0.40, while the spectrum of the source can be fitted with an optically thin plasma model. We interpret this source as a foreground active star of late spectral type. The second source has no optical counterpart to a limiting magnitude ~ 21. The spectrum of this source can be fitted almost equally well with several simple models (power law: photon index =1.87; two-temperature blackbody: kT1 =0.11 keV, R1 =2.34 km and kT2 =0.71 keV, R2 =0.06 km; blackbody plus power law: kT =0.07 keV, photon index =2.3). We interpret this source as a candidate stellar remnant (neutron star), while the photon index and non-thermal luminosity of the source (almost the same as those of the Vela pulsar and the recently discovered pulsar PSR J 0205+6449 in the supernova remnant 3C 58) suggest that it can be a young ``ordinary" pulsar.

  15. Development of radioactive source scanner based on PLC

    International Nuclear Information System (INIS)

    Yang Guogui; Gao Xiang; Guo Hongli

    2013-01-01

    The radioactive radial uniformity of 68 Ge line radioactive sources is a critical quality parameter. The radioactive source scanner with linear scanning function is developed by making use of high-speed pulse counters, high-speed pulse output ports, and the powerful instruction system of Siemens S7-200 series programmable logic controller (PLC). A computer used as a host computer of the instrument communicate with. the PLC by point to point interface (PPI) protocol, The instrument with functions of data collection, transmission, displaying, saving, motion control and instrument parameter settings, can be used to measure the radioactive radial uniformity and total activity of line radioactive source. The advantages of Using the PLC to develop nuclear instrumentation are development speed, strong anti-interference ability, and low-cost. This paper mainly describes the control system implementation and feature of the instrument. (authors)

  16. Application of point system in the project control of Ling'ao Nuclear Power Station

    International Nuclear Information System (INIS)

    Xie ahai

    2005-01-01

    Schedule control and cost control are very complicated issues even we set up the detail schedules and engineering measurements requirements for erection of a nuclear power project. In order to solve these problems, a Point System is used in Ling Ao (LA) Nuclear Power Project. This paper introduces the method. The Point System is a measurement system of workload. The measurement unit of any erection works is a Point only. A Point of workload is defined as the equivalent measurement quantities, which could be completed by a relevant skill worker within an hour. A set of procedure manuals for different installations has been set up. The calculation models of equipment installation, piping, cabling are addressed for example in the paper. The application of the Point System in the schedule control is shown in the paper. The following issues are highlighted: to define the duration of a piping activity in the Project Level 2 Schedule, to draught the curves of Point Schedules for different erection fields, to analyze the productive efficiency, to define erection quota of each month for different erection teams, to follow up the erection progress on site. The application of the Point System in the payment of erection contract is outlined. The calculation formula of a monthly payment is given. The advantage of the payment calculation method is discussed, for example, more accurate, very easy and clearly to check the measurement quantities completed on site, to control lump-sum cost. (authors)

  17. A Current Control Approach for an Abnormal Grid Supplied Ultra Sparse Z-Source Matrix Converter with a Particle Swarm Optimization Proportional-Integral Induction Motor Drive Controller

    Directory of Open Access Journals (Sweden)

    Seyed Sina Sebtahmadi

    2016-11-01

    Full Text Available A rotational d-q current control scheme based on a Particle Swarm Optimization- Proportional-Integral (PSO-PI controller, is used to drive an induction motor (IM through an Ultra Sparse Z-source Matrix Converter (USZSMC. To minimize the overall size of the system, the lowest feasible values of Z-source elements are calculated by considering the both timing and aspects of the circuit. A meta-heuristic method is integrated to the control system in order to find optimal coefficient values in a single multimodal problem. Henceforth, the effect of all coefficients in minimizing the total harmonic distortion (THD and balancing the stator current are considered simultaneously. Through changing the reference point of magnitude or frequency, the modulation index can be automatically adjusted and respond to changes without heavy computational cost. The focus of this research is on a reliable and lightweight system with low computational resources. The proposed scheme is validated through both simulation and experimental results.

  18. A simple maximum power point tracker for thermoelectric generators

    International Nuclear Information System (INIS)

    Paraskevas, Alexandros; Koutroulis, Eftichios

    2016-01-01

    Highlights: • A Maximum Power Point Tracking (MPPT) method for thermoelectric generators is proposed. • A power converter is controlled to operate on a pre-programmed locus. • The proposed MPPT technique has the advantage of operational and design simplicity. • The experimental average deviation from the MPP power of the TEG source is 1.87%. - Abstract: ThermoElectric Generators (TEGs) are capable to harvest the ambient thermal energy for power-supplying sensors, actuators, biomedical devices etc. in the μW up to several hundreds of Watts range. In this paper, a Maximum Power Point Tracking (MPPT) method for TEG elements is proposed, which is based on controlling a power converter such that it operates on a pre-programmed locus of operating points close to the MPPs of the power–voltage curves of the TEG power source. Compared to the past-proposed MPPT methods for TEGs, the technique presented in this paper has the advantage of operational and design simplicity. Thus, its implementation using off-the-shelf microelectronic components with low-power consumption characteristics is enabled, without being required to employ specialized integrated circuits or signal processing units of high development cost. Experimental results are presented, which demonstrate that for MPP power levels of the TEG source in the range of 1–17 mW, the average deviation of the power produced by the proposed system from the MPP power of the TEG source is 1.87%.

  19. Iterative image reconstruction for positron emission tomography based on a detector response function estimated from point source measurements

    International Nuclear Information System (INIS)

    Tohme, Michel S; Qi Jinyi

    2009-01-01

    The accuracy of the system model in an iterative reconstruction algorithm greatly affects the quality of reconstructed positron emission tomography (PET) images. For efficient computation in reconstruction, the system model in PET can be factored into a product of a geometric projection matrix and sinogram blurring matrix, where the former is often computed based on analytical calculation, and the latter is estimated using Monte Carlo simulations. Direct measurement of a sinogram blurring matrix is difficult in practice because of the requirement of a collimated source. In this work, we propose a method to estimate the 2D blurring kernels from uncollimated point source measurements. Since the resulting sinogram blurring matrix stems from actual measurements, it can take into account the physical effects in the photon detection process that are difficult or impossible to model in a Monte Carlo (MC) simulation, and hence provide a more accurate system model. Another advantage of the proposed method over MC simulation is that it can easily be applied to data that have undergone a transformation to reduce the data size (e.g., Fourier rebinning). Point source measurements were acquired with high count statistics in a relatively fine grid inside the microPET II scanner using a high-precision 2D motion stage. A monotonically convergent iterative algorithm has been derived to estimate the detector blurring matrix from the point source measurements. The algorithm takes advantage of the rotational symmetry of the PET scanner and explicitly models the detector block structure. The resulting sinogram blurring matrix is incorporated into a maximum a posteriori (MAP) image reconstruction algorithm. The proposed method has been validated using a 3 x 3 line phantom, an ultra-micro resolution phantom and a 22 Na point source superimposed on a warm background. The results of the proposed method show improvements in both resolution and contrast ratio when compared with the MAP

  20. Kernel integration scatter model for parallel beam gamma camera and SPECT point source response

    International Nuclear Information System (INIS)

    Marinkovic, P.M.

    2001-01-01

    Scatter correction is a prerequisite for quantitative single photon emission computed tomography (SPECT). In this paper a kernel integration scatter Scatter correction is a prerequisite for quantitative SPECT. In this paper a kernel integration scatter model for parallel beam gamma camera and SPECT point source response based on Klein-Nishina formula is proposed. This method models primary photon distribution as well as first Compton scattering. It also includes a correction for multiple scattering by applying a point isotropic single medium buildup factor for the path segment between the point of scatter an the point of detection. Gamma ray attenuation in the object of imaging, based on known μ-map distribution, is considered too. Intrinsic spatial resolution of the camera is approximated by a simple Gaussian function. Collimator is modeled simply using acceptance angles derived from the physical dimensions of the collimator. Any gamma rays satisfying this angle were passed through the collimator to the crystal. Septal penetration and scatter in the collimator were not included in the model. The method was validated by comparison with Monte Carlo MCNP-4a numerical phantom simulation and excellent results were obtained. The physical phantom experiments, to confirm this method, are planed to be done. (author)

  1. The regulatory control of radioactive sources in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Rojkind, Roberto Hector [Autoridade Regulatoria Nuclear, Buenos Aires (Argentina)

    1997-12-31

    Argentina has been conducting nuclear activities for more than forty years, and as early as in 1956 established a Regulatory Authority. Procedures for compliance monitoring and enforcement have been in use in the regulatory control of radioactive sources, and regulatory standards and regulations had been set in Argentina, before the accident in Goiania. The conclusions drawn from that accident encouraged in Argentina the improvement of some regulatory procedures and helped to enhance the quality of the regulatory process. Therefore, the effectiveness of the control of spent radioactive sources has gradually increased, and enforcement actions to prevent radioactive sources ending up in the public domain improved. Some lessons learned in Argentina from the accident in Goiania and the main characteristics of an effective enforcement program helpful to prevent radiological accidents in industrial, medical, research and teaching uses of radioactive sources are presented. (author) 9 refs; e-mail: rrojkind at sede.arn.gov.br

  2. Search for atmospheric muon-neutrinos and extraterrestric neutrino point sources in the 1997 AMANDA-B10 data

    International Nuclear Information System (INIS)

    Biron von Curland, A.

    2002-07-01

    The young field of high energy neutrino astronomy can be motivated by the search for the origin of the charged cosmic rays. Large astrophysical objects like AGNs or supernova remnants are candidates to accelerate hadrons which then can interact to eventually produce high energy neutrinos. Neutrino-induced muons can be detected via their emission of Cherenkov light in large neutrino telescopes like AMANDA. More than 10 9 atmospheric muon events and approximately 5000 atmospheric neutrino events were registered by AMANDA-B10 in 1997. Out of these, 223 atmospheric neutrino candidate events have been extracted. This data set contains approximately 15 background events. It allows to confirm the expected sensitivity of the detector towards neutrino events. A second set containing 369 (approximately 270 atmospheric neutrino events and 100 atmospheric muon events) was used to search for extraterrestrial neutrino point sources. Neither a binned search, nor a cluster search, nor a search for preselected sources gave indications for the existence of a strong neutrino point source. Based on this result, flux limits were derived. Assuming E ν -2 spectra, typical flux limits for selected sources of the order of Φ μ limit ∝ 10 -14 cm -2 s -1 for muons and Φ ν limit ∝ 10 -7 cm -2 s -1 for neutrinos have been obtained. (orig.)

  3. An optimising controller for Hinkley Point B AGR boilers

    International Nuclear Information System (INIS)

    Wells, C.

    1986-01-01

    The improvements to the control system at Hinkley Point 'B' Power Station has as one of its objectives the provision of a half unit valve controller. This will enable the asymmetry between the boiler half units, which is a feature of current operation, to be reduced. The use of an on-line boiler model in conjunction with this facility will allow the risk to the boilers from corrosion, creep, and vibration to be assessed and held at the minimum attainable value, thereby prolonging plant life whilst maximising output and efficiency. (author)

  4. Power conversion and control methods for renewable energy sources

    Science.gov (United States)

    Yu, Dachuan

    2005-07-01

    In recent years, there has been an increase in the use of renewable energy due to the growing concern over the pollution caused by fossil-fuel-based energy. Renewable energy sources, such as photovoltaic (PV) and fuel cell, can be used to enhance the safety, reliability, sustainability, and transmission efficiency of a power system. This dissertation focuses on the power conversion and control for two major renewable-energy sources: PV and fuel cell. Firstly, a current-based, maximum power-point tracking (MPPT) algorithm is proposed for PV energy. An economical converter system using the above scheme for converting the output from PV panels into 60 Hz AC voltage is developed and built. Secondly, a novel circuit model for the Proton Exchange Membrane (PEM) fuel-cell stack that is useful in the design and analysis of fuel-cell-based power systems is proposed. This Pspice-based model uses elements available in the Pspice library with some modifications to represent both the static and dynamic responses of a PEM fuel-cell module. The accuracy of the model is verified by comparing the simulation and experimental results. Thirdly, a DSP-controlled three-phase induction-motor drive using constant voltage over frequency is built and can be used in a fuel-cell automobile. A hydrogen sensor is used in the drive to both sound an alarm and shut down the inverter trigger pulses through the DSP. Finally, a hybrid power system consisting of PV panels and fuel cell is proposed and built. In the proposed system, PV panels can supply most of the power when the sunlight is available, and the excess power required by the load is supplied by a fuel cell. Load sharing between a fuel cell (FC) and the PV panel is investigated by both simulation and experiments.

  5. Watershed-based point sources permitting strategy and dynamic permit-trading analysis.

    Science.gov (United States)

    Ning, Shu-Kuang; Chang, Ni-Bin

    2007-09-01

    Permit-trading policy in a total maximum daily load (TMDL) program may provide an additional avenue to produce environmental benefit, which closely approximates what would be achieved through a command and control approach, with relatively lower costs. One of the important considerations that might affect the effective trading mechanism is to determine the dynamic transaction prices and trading ratios in response to seasonal changes of assimilative capacity in the river. Advanced studies associated with multi-temporal spatially varied trading ratios among point sources to manage water pollution hold considerable potential for industries and policy makers alike. This paper aims to present an integrated simulation and optimization analysis for generating spatially varied trading ratios and evaluating seasonal transaction prices accordingly. It is designed to configure a permit-trading structure basin-wide and provide decision makers with a wealth of cost-effective, technology-oriented, risk-informed, and community-based management strategies. The case study, seamlessly integrating a QUAL2E simulation model with an optimal waste load allocation (WLA) scheme in a designated TMDL study area, helps understand the complexity of varying environmental resources values over space and time. The pollutants of concern in this region, which are eligible for trading, mainly include both biochemical oxygen demand (BOD) and ammonia-nitrogen (NH3-N). The problem solution, as a consequence, suggests an array of waste load reduction targets in a well-defined WLA scheme and exhibits a dynamic permit-trading framework among different sub-watersheds in the study area. Research findings gained in this paper may extend to any transferable dynamic-discharge permit (TDDP) program worldwide.

  6. A conceptual study on the formulation of a permeable reactive pavement with activated carbon additives for controlling the fate of non-point source environmental organic contaminants.

    Science.gov (United States)

    Huang, Shengyi; Liang, Chenju

    2018-02-01

    To take advantage of the road pavement network where non-point source (NPS) pollution such as benzene, toluene, ethyl-benzene, and xylene (BTEX) from vehicle traffic exhaust via wet and dry atmospheric deposition occurs, the asphalt pavement may be used as a media to control the NPS pollution. An experiment to prepare an adsorptive porous reactive pavement (PRP) was initiated to explore the potential to reduce environmental NPS vehicle pollution. The PRP was prepared and studied as follows: various activated carbons (AC) were initially screened to determine if they were suitable as an additive in the porous asphalt mixture; various mixtures of a selected AC were incorporated with the design of porous asphalt concrete (PAC) to produce PRP, and the PRP formulations were tested to ensure that they comply with the required specifications; qualified specimens were subsequently tested to determine their adsorption capacity for BTEX in aqueous solution, as compared to conventional PAC. The PRP08 and PRP16 samples, named for the design formulations of 0.8% and 1.6% of AC (by wt. in the formulation), exhibited low asphalt drain-down and low abrasion loss and also met all regulated specifications. The BTEX adsorption capacity measurements of PRP08 and PRP16 were 33-46%, 36-51%, 20-22%, and 6-8% respectively, higher than those obtained from PACs. Based on the test results, PRPs showed good physical performance and adsorption and may be considered as a potential method for controlling the transport of NPS vehicle pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Rate-control algorithms testing by using video source model

    DEFF Research Database (Denmark)

    Belyaev, Evgeny; Turlikov, Andrey; Ukhanova, Anna

    2008-01-01

    In this paper the method of rate control algorithms testing by the use of video source model is suggested. The proposed method allows to significantly improve algorithms testing over the big test set.......In this paper the method of rate control algorithms testing by the use of video source model is suggested. The proposed method allows to significantly improve algorithms testing over the big test set....

  8. [Bibliometric analysis of literature regarding integrated schistosomiasis control strategy with emphasis on infectious source control].

    Science.gov (United States)

    Qian, Yi-Li; Wang, Wei; Hong, Qing-Biao; Liang, You-Sheng

    2014-12-01

    To evaluate the outcomes of implementation of integrated schistosomiasis control strategy with emphasis on infectious source control using a bibliometric method. The literature pertaining to integrated schistosomiasis control strategy with emphasis on infectious source control was retrieved from CNKI, Wanfangdata, VIP, PubMed, Web of Science, BIOSIS and Google Scholar, and a bibliometric analysis of literature captured was performed. During the period from January 1, 2004 through September 30, 2014, a total of 94 publications regarding integrated schistosomiasis control strategy with emphasis on infectious source control were captured, including 78 Chinese articles (82.98%) and 16 English papers (17.02%). The Chinese literature was published in 21 national journals, and Chinese Journal of Schistosomiasis Control had the largest number of publications, consisting of 37.23% of total publications; 16 English papers were published in 12 international journals, and PLoS Neglected Tropical Diseases had the largest number of publications (3 publications). There were 37 affiliations publishing these 94 articles, and National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (16 publications), Anhui Institute of Schistosomiasis Control (12 publications) and Hunan Institute of Schistosomiasis Control (9 publications) ranked top three affiliations in number of publications. A total of 157 persons were co-authored in these 94 publications, and Wang, Zhou and Zhang ranked top 3 authors in number of publications. The integrated schistosomiasis control strategy with emphasis on infectious source control has been widely implemented in China, and the achievements obtained from the implementation of this strategy should be summarized and transmitted internationally.

  9. National strategies for improving control over orphan sources of ionising radiation

    International Nuclear Information System (INIS)

    Nizamska, M.

    2007-01-01

    Since 1989 Bulgaria started reformation of economy sector. Part of this process is the intensive privatisation, as well as in the sited using radioactive materials for different applications - industry, medicine, agriculture, etc. The quick change of property ownership results in difficulties to identify the assessor of radioactive source or material and finally led to appearance of orphan sources. A orphan source is defined as a source that poses sufficient radiological hazard to warrant regulatory control, but which is not under regulatory control because it has never been so, or because it has been abandoned, lost, misplaced, stolen or otherwise transferred without proper authorisation. A face on these problems, Bulgaria is performing a series of measure to improve the control over orphan sources and to strengthening the control over the nuclear and radioactive materials. The report presents briefly this measures. (author)

  10. Calculation of total counting efficiency of a NaI(Tl) detector by hybrid Monte-Carlo method for point and disk sources

    Energy Technology Data Exchange (ETDEWEB)

    Yalcin, S. [Education Faculty, Kastamonu University, 37200 Kastamonu (Turkey)], E-mail: yalcin@gazi.edu.tr; Gurler, O.; Kaynak, G. [Department of Physics, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Gundogdu, O. [Department of Physics, School of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2007-10-15

    This paper presents results on the total gamma counting efficiency of a NaI(Tl) detector from point and disk sources. The directions of photons emitted from the source were determined by Monte-Carlo techniques and the photon path lengths in the detector were determined by analytic equations depending on photon directions. This is called the hybrid Monte-Carlo method where analytical expressions are incorporated into the Monte-Carlo simulations. A major advantage of this technique is the short computation time compared to other techniques on similar computational platforms. Another advantage is the flexibility for inputting detector-related parameters (such as source-detector distance, detector radius, source radius, detector linear attenuation coefficient) into the algorithm developed, thus making it an easy and flexible method to apply to other detector systems and configurations. The results of the total counting efficiency model put forward for point and disc sources were compared with the previous work reported in the literature.

  11. Calculation of total counting efficiency of a NaI(Tl) detector by hybrid Monte-Carlo method for point and disk sources

    International Nuclear Information System (INIS)

    Yalcin, S.; Gurler, O.; Kaynak, G.; Gundogdu, O.

    2007-01-01

    This paper presents results on the total gamma counting efficiency of a NaI(Tl) detector from point and disk sources. The directions of photons emitted from the source were determined by Monte-Carlo techniques and the photon path lengths in the detector were determined by analytic equations depending on photon directions. This is called the hybrid Monte-Carlo method where analytical expressions are incorporated into the Monte-Carlo simulations. A major advantage of this technique is the short computation time compared to other techniques on similar computational platforms. Another advantage is the flexibility for inputting detector-related parameters (such as source-detector distance, detector radius, source radius, detector linear attenuation coefficient) into the algorithm developed, thus making it an easy and flexible method to apply to other detector systems and configurations. The results of the total counting efficiency model put forward for point and disc sources were compared with the previous work reported in the literature

  12. Remotely controlled repairs at Douglas Point NGS

    International Nuclear Information System (INIS)

    Broad, Les

    In September, 1977, leakage of heavy water at a rate of 125 kg/hr was detected in an area of the Douglas Point NGS reactor vault below the calandria known as the lower labyrinth. Radiation in the area ranges up to 5000 R/hr and the only ready access was through four 75 mm inspection ports that open into the moderator room. Remote-controlled equipment was designed and built to diagnose the problems and carry out repairs. All damaged piping was fixed, supports were replaced as needed, and system vibration was reduced. The work was done with no injuries and little radiation dose

  13. Femtosecond Light Source for Phase-Controlled Multiphoton Ionization

    International Nuclear Information System (INIS)

    Sokolov, A. V.; Walker, D. R.; Yavuz, D. D.; Yin, G. Y.; Harris, S. E.

    2001-01-01

    We describe a femtosecond Raman light source with more than an octave of optical bandwidth. We use this source to demonstrate phase control of multiphoton ionization under conditions where ionization requires eleven photons of the lowest frequency of the spectrum or five photons of the highest frequency. The nonlinearity of the photoionization process allows us to characterize the light source. Experiment-to-theory comparison implies generation of a near single-cycle waveform

  14. Field Operations and Enforcement Manual for Air Pollution Control. Volume II: Control Technology and General Source Inspection.

    Science.gov (United States)

    Weisburd, Melvin I.

    The Field Operations and Enforcement Manual for Air Pollution Control, Volume II, explains in detail the following: technology of source control, modification of operations, particulate control equipment, sulfur dioxide removal systems for power plants, and control equipment for gases and vapors; inspection procedures for general sources, fuel…

  15. A Modified Droop Control Method for Parallel-Connected Current Source Inverters

    DEFF Research Database (Denmark)

    Wei, Baoze; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2016-01-01

    In this paper, a novel control method was proposed for current source inverters under the grid-connected working mode. The control scheme is based on a modified droop control method, with an additional current reference signal that will be generated instead of the voltage reference. Hence......, there is only a current control loop with droop control in the whole control scheme without voltage control loop. So it is very suitable for grid-connected current source inverter which will simplify the design of the control scheme and combine the advantage of droop control. The parallel configuration...... is widely used to acquire high power demand, but the circulating current problem is a key issue that should be considered. In this paper, a simulation based on parallel current source inverters using the proposed control scheme is provided. Simulation results showed that a good circulating current...

  16. 238Pu sources for cardiac pacemakers. II. Control

    International Nuclear Information System (INIS)

    Pottier, R.; Merigot, S.

    1976-01-01

    The method and the apparatus used for thermal (power) and radioactive control of radioisotopic sources for pacemakers are briefly described. The cybernetic system is also presented, which assumes almost automatically the monitoring of control, mechanical and electronic works, data processing, the measurements and computations, and the works related to quality control [fr

  17. BRIGITTE, Dose Rate and Heat Source and Energy Flux for Self-Absorbing Rods

    International Nuclear Information System (INIS)

    Jegu, M.; Clement, M.

    1978-01-01

    1 - Nature of physical problem solved: Calculation of dose rate, heat sources or energy flux. The sources are self-absorbing radioactive rods. The shielding consists of blocks of which the cross section can be defined. 2 - Method of solution: Exponential attenuation and build-up factor between source points and detector points. Source integration with error estimate. Automatic or controlled build-up with monitor print-out. 3 - Restrictions on the complexity of the problem: Number of energy points, regions, detector points, abscissa points of the rod, vertical position of the rod, are all limited to ten. The maximum total number of vertical steps is 124

  18. Generalized space vector control for current source inverters and rectifiers

    Directory of Open Access Journals (Sweden)

    Roseline J. Anitha

    2016-06-01

    Full Text Available Current source inverters (CSI is one of the widely used converter topology in medium voltage drive applications due to its simplicity, motor friendly waveforms and reliable short circuit protection. The current source inverters are usually fed by controlled current source rectifiers (CSR with a large inductor to provide a constant supply current. A generalized control applicable for both CSI and CSR and their extension namely current source multilevel inverters (CSMLI are dealt in this paper. As space vector pulse width modulation (SVPWM features the advantages of flexible control, faster dynamic response, better DC utilization and easy digital implementation it is considered for this work. This paper generalizes SVPWM that could be applied for CSI, CSR and CSMLI. The intense computation involved in framing a generalized space vector control are discussed in detail. The algorithm includes determination of band, region, subregions and vectors. The algorithm is validated by simulation using MATLAB /SIMULINK for CSR 5, 7, 13 level CSMLI and for CSR fed CSI.

  19. Control of tongue movements in speech: The Equilibrium point Hypothesis perspective

    OpenAIRE

    Perrier , Pascal; Loevenbruck , Hélène; Payan , Yohan

    1996-01-01

    In this paper , the application of the Equilibrium Point Hypothesis— originally proposed by Feldman for the control of limb movements— to speech control is analysed . In the first part , physiological data published in the literature which argue in favour of such control for the tongue are presented and the possible role of this motor process in a global control model of the tongue is explicated . In the second part , using the example of the acoustic variability associated with vowel reducti...

  20. Regulatory control of radiation sources in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Daroy, Rosita R

    1996-12-31

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI`s regulatory functions are presented. (author). Paper presented during the IAEA Regional (RCA) Workshop on System of Notification, Registration, Licensing, and Control of Radiation Sources and Installations, Jakarta, Indonesia, 24-28 April 1995. 6 refs., 2 figs., 12 tabs.

  1. Preliminary limits on the flux of muon neutrinos from extraterrestrial point sources

    International Nuclear Information System (INIS)

    Bionta, R.M.; Blewitt, G.; Bratton, C.B.

    1985-01-01

    We present the arrival directions of 117 upward-going muon events collected with the IMB proton lifetime detector during 317 days of live detector operation. The rate of upward-going muons observed in our detector was found to be consistent with the rate expected from atmospheric neutrino production. The upper limit on the total flux of extraterrestrial neutrinos >1 GeV is 2 -sec. Using our data and a Monte Carlo simulation of high energy muon production in the earth surrounding the detector, we place limits on the flux of neutrinos from a point source in the Vela X-2 system of 2 -sec with E > 1 GeV. 6 refs., 5 figs

  2. Considering a point-source in a regional air pollution model; Prise en compte d`une source ponctuelle dans un modele regional de pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Lipphardt, M.

    1997-06-19

    This thesis deals with the development and validation of a point-source plume model, with the aim to refine the representation of intensive point-source emissions in regional-scale air quality models. The plume is modelled at four levels of increasing complexity, from a modified Gaussian plume model to the Freiberg and Lusis ring model. Plume elevation is determined by Netterville`s plume rise model, using turbulence and atmospheric stability parameters. A model for the effect of a fine-scale turbulence on the mean concentrations in the plume is developed and integrated in the ring model. A comparison between results with and without considering micro-mixing shows the importance of this effect in a chemically reactive plume. The plume model is integrated into the Eulerian transport/chemistry model AIRQUAL, using an interface between Airqual and the sub-model, and interactions between the two scales are described. A simulation of an air pollution episode over Paris is carried out, showing that the utilization of such a sub-scale model improves the accuracy of the air quality model

  3. Computer aided control of the Bonn Penning polarized ion source

    International Nuclear Information System (INIS)

    He, N.W.; VonRossen, P.; Eversheim, P.D.; Busch, R.

    1984-01-01

    A CBM computer system is described which has been set up to control the Bonn Polarized Ion Source. The controlling program, besides setting and logging parameters, performs an optimization of the ion source output. A free definable figure of merit, being composed of the current of the ionizer and its variance, has proven to be an effective means in directing the source optimization. The performance that has been reached during the first successful tests is reported

  4. Remotely controlled repair of piping at Douglas Point

    International Nuclear Information System (INIS)

    Conrath, J.J.

    1983-06-01

    The 200 MWe Douglas Point Nuclear Generating Station which started operation in 1966 was Canada's first commercial nuclear power plant. In 1977, after 11 years of operation, leakage of heavy water was detected and traced to the Moderator Piping System (pipe sizes 19 mm to 76 mm) located in a vault below the reactor where the radiation fields during shutdown ranged up to 5000 R/Hr. Inspection using remotely operated TV cameras showed that a 'U' bolt clamp support had worn through the wall of one pipe and resulted in the leakage and also that wear was occurring on other pipes. An extensive repair plan was subsequently undertaken in the form of a joint venture of the designer-owner Atomic Energy of Canada Limited, and the builder-operator, Ontario Hydro. This paper describes the equipment and procedures used in remotely controlled repairs at Douglas Point

  5. Testing of an End-Point Control Unit Designed to Enable Precision Control of Manipulator-Coupled Spacecraft

    Science.gov (United States)

    Montgomery, Raymond C.; Ghosh, Dave; Tobbe, Patrick A.; Weathers, John M.; Manouchehri, Davoud; Lindsay, Thomas S.

    1994-01-01

    This paper presents an end-point control concept designed to enable precision telerobotic control of manipulator-coupled spacecraft. The concept employs a hardware unit (end-point control unit EPCU) that is positioned between the end-effector of the Space Shuttle Remote Manipulator System and the payload. Features of the unit are active compliance (control of the displacement between the end-effector and the payload), to allow precision control of payload motions, and inertial load relief, to prevent the transmission of loads between the end-effector and the payload. This paper presents the concept and studies the active compliance feature using a simulation and hardware. Results of the simulation show the effectiveness of the EPCU in smoothing the motion of the payload. Results are presented from initial, limited tests of a laboratory hardware unit on a robotic arm testbed at the l Space Flight Center. Tracking performance of the arm in a constant speed automated retraction and extension maneuver of a heavy payload with and without the unit active is compared for the design speed and higher speeds. Simultaneous load reduction and tracking performance are demonstrated using the EPCU.

  6. Analysis on Single Point Vulnerabilities of Plant Control System

    International Nuclear Information System (INIS)

    Chi, Moon Goo; Lee, Eun Chan; Bae, Yeon Kyoung

    2011-01-01

    The Plant Control System (PCS) is a system that controls pumps, valves, dampers, etc. in nuclear power plants with an OPR-1000 design. When there is a failure or spurious actuation of the critical components in the PCS, it can result in unexpected plant trips or transients. From this viewpoint, single point vulnerabilities are evaluated in detail using failure mode effect analyses (FMEA) and fault tree analyses (FTA). This evaluation demonstrates that the PCS has many vulnerable components and the analysis results are provided for OPR-1000 plants for reliability improvements that can reduce their vulnerabilities

  7. Analysis on Single Point Vulnerabilities of Plant Control System

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Moon Goo; Lee, Eun Chan; Bae, Yeon Kyoung [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2011-08-15

    The Plant Control System (PCS) is a system that controls pumps, valves, dampers, etc. in nuclear power plants with an OPR-1000 design. When there is a failure or spurious actuation of the critical components in the PCS, it can result in unexpected plant trips or transients. From this viewpoint, single point vulnerabilities are evaluated in detail using failure mode effect analyses (FMEA) and fault tree analyses (FTA). This evaluation demonstrates that the PCS has many vulnerable components and the analysis results are provided for OPR-1000 plants for reliability improvements that can reduce their vulnerabilities.

  8. Fissile material detection and control facility with pulsed neutron sources and digital data processing

    International Nuclear Information System (INIS)

    Romodanov, V.L.; Chernikova, D.N.; Afanasiev, V.V.

    2010-01-01

    Full text: In connection with possible nuclear terrorism, there is long-felt need of devices for effective control of radioactive and fissile materials in the key points of crossing the state borders (airports, seaports, etc.), as well as various customs check-points. In International Science and Technology Center Projects No. 596 and No. 2978, a new physical method and digital technology have been developed for the detection of fissile and radioactive materials in models of customs facilities with a graphite moderator, pulsed neutron source and digital processing of responses from scintillation PSD detectors. Detectability of fissile materials, even those shielded with various radiation-absorbing screens, has been shown. The use of digital processing of scintillation signals in this facility is a necessary element, as neutrons and photons are discriminated in the time dependence of fissile materials responses at such loads on the electronic channels that standard types of spectrometers are inapplicable. Digital processing of neutron and photon responses practically resolves the problem of dead time and allows implementing devices, in which various energy groups of neutrons exist for some time after a pulse of source neutrons. Thus, it is possible to detect fissile materials deliberately concealed with shields having a large cross-section of absorption of photons and thermal neutrons. Two models of detection and the control of fissile materials were advanced: 1. the model based on graphite neutrons moderator and PSD scintillators with digital technology of neutrons and photons responses separation; 2. the model based on plastic scintillators and detecting of time coincidences of fission particles by digital technology. Facilities that count time coincidences of neutrons and photons occurring in the fission of fissile materials can use an Am Li source of neutrons, e.g. that is the case with the AWCC system. The disadvantages of the facility are related to the issues

  9. Retailer opinions about and compliance with family smoking prevention and tobacco control act point of sale provisions: a survey of tobacco retailers.

    Science.gov (United States)

    Rose, Shyanika W; Emery, Sherry L; Ennett, Susan; Reyes, Heathe Luz McNaughton; Scott, John C; Ribisl, Kurt M

    2015-09-11

    The objectives of this study were to document retailer opinions about tobacco control policy at the point of sale (POS) and link these opinions with store level compliance with sales and marketing provisions of the Tobacco Control Act. This study conducted interviews of 252 tobacco retailers in three counties in North Carolina and linked their opinions with in-person observational audit data of their stores' compliance with POS policies. We conducted analyses examining retailer factors associated with noncompliance using Generalized Estimating Equations (GEE) controlling for individual, store, neighborhood, and county factors. Over 90 % of retailers support minors' access provisions and a large minority (over 40 %) support graphic warnings and promotion bans. Low levels of support were found for a potential ban on menthol cigarettes (17 %). Store noncompliance with tobacco control policies was associated with both more reported retailer barriers to compliance and less support for POS policies. Awareness of and source of information about tobacco control regulations were not associated with compliance when accounting for neighborhood and county characteristics. Retailers expressed some support for a wide range of POS policies. Advocates and government agencies tasked with enforcement can work with retailers as stakeholders to enhance support, mitigate barriers, and promote compliance with tobacco control efforts at the point of sale.

  10. Non-uniform dwell times in line source high dose rate brachytherapy: physical and radiobiological considerations

    International Nuclear Information System (INIS)

    Jones, B.; Tan, L.T.; Freestone, G.; Bleasdale, C.; Myint, S.; Littler, J.

    1994-01-01

    The ability to vary source dwell times in high dose rate (HDR) brachytherapy allows for the use of non-uniform dwell times along a line source. This may have advantages in the radical treatment of tumours depending on individual tumour geometry. This study investigates the potential improvements in local tumour control relative to adjacent normal tissue isoeffects when intratumour source dwell times are increased along the central portion of a line source (technique A) in radiotherapy schedules which include a relatively small component of HDR brachytherapy. Such a technique is predicted to increase the local control for tumours of diameters ranging between 2 cm and 4 cm by up to 11% compared with a technique in which there are uniform dwell times along the line source (technique B). There is no difference in the local control rates for the two techniques when used to treat smaller tumours. Normal tissue doses are also modified by the technique used. Technique A produces higher normal tissue doses at points perpendicular to the centre of the line source and lower dose at points nearer the ends of the line source if the prescription point is not in the central plane of the line source. Alternatively, if the dose is prescribed at a point in the central plane of the line source, the dose at all the normal tissue points are lower when technique A is used. (author)

  11. Performance summary on a high power dense plasma focus x-ray lithography point source producing 70 nm line features in AlGaAs microcircuits

    International Nuclear Information System (INIS)

    Petr, Rodney; Bykanov, Alexander; Freshman, Jay; Reilly, Dennis; Mangano, Joseph; Roche, Maureen; Dickenson, Jason; Burte, Mitchell; Heaton, John

    2004-01-01

    A high average power dense plasma focus (DPF), x-ray point source has been used to produce ∼70 nm line features in AlGaAs-based monolithic millimeter-wave integrated circuits (MMICs). The DPF source has produced up to 12 J per pulse of x-ray energy into 4π steradians at ∼1 keV effective wavelength in ∼2 Torr neon at pulse repetition rates up to 60 Hz, with an effective x-ray yield efficiency of ∼0.8%. Plasma temperature and electron concentration are estimated from the x-ray spectrum to be ∼170 eV and ∼5·10 19 cm -3 , respectively. The x-ray point source utilizes solid-state pulse power technology to extend the operating lifetime of electrodes and insulators in the DPF discharge. By eliminating current reversals in the DPF head, an anode electrode has demonstrated a lifetime of more than 5 million shots. The x-ray point source has also been operated continuously for 8 h run times at 27 Hz average pulse recurrent frequency. Measurements of shock waves produced by the plasma discharge indicate that overpressure pulses must be attenuated before a collimator can be integrated with the DPF point source

  12. Implementation of Maximum Power Point Tracking (MPPT) Solar Charge Controller using Arduino

    Science.gov (United States)

    Abdelilah, B.; Mouna, A.; KouiderM’Sirdi, N.; El Hossain, A.

    2018-05-01

    the platform Arduino with a number of sensors standard can be used as components of an electronic system for acquiring measures and controls. This paper presents the design of a low-cost and effective solar charge controller. This system includes several elements such as the solar panel converter DC/DC, battery, circuit MPPT using Microcontroller, sensors, and the MPPT algorithm. The MPPT (Maximum Power Point Tracker) algorithm has been implemented using an Arduino Nano with the preferred program. The voltage and current of the Panel are taken where the program implemented will work and using this algorithm that MPP will be reached. This paper provides details on the solar charge control device at the maximum power point. The results include the change of the duty cycle with the change in load and thus mean the variation of the buck converter output voltage and current controlled by the MPPT algorithm.

  13. Five-Level Z-Source Neutral Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Blaabjerg, Frede

    2007-01-01

    This paper proposes a five-level Z-source neutralpoint- clamped (NPC) inverter with two Z-source networks functioning as intermediate energy storages coupled between dc sources and NPC inverter circuitry. Analyzing the operational principles of Z-source network with partial dclink shoot......-through scheme reveals the hidden theories in the five-level Z-source NPC inverter unlike the operational principle appeared in the general two-level Z-source inverter, so that the five-level Z-source NPC inverter can be designed with the modulation of carrier-based phase disposition (PD) or alternative phase...

  14. On-site meteorological instrumentation requirements to characterize diffusion from point sources: workshop report. Final report Sep 79-Sep 80

    International Nuclear Information System (INIS)

    Strimaitis, D.; Hoffnagle, G.; Bass, A.

    1981-04-01

    Results of a workshop entitled 'On-Site Meteorological Instrumentation Requirements to Characterize Diffusion from Point Sources' are summarized and reported. The workshop was sponsored by the U.S. Environmental Protection Agency in Raleigh, North Carolina, on January 15-17, 1980. Its purpose was to provide EPA with a thorough examination of the meteorological instrumentation and data collection requirements needed to characterize airborne dispersion of air contaminants from point sources and to recommend, based on an expert consensus, specific measurement technique and accuracies. Secondary purposes of the workshop were to (1) make recommendations to the National Weather Service (NWS) about collecting and archiving meteorological data that would best support air quality dispersion modeling objectives and (2) make recommendations on standardization of meteorological data reporting and quality assurance programs

  15. [Estimation of urban non-point source pollution loading and its factor analysis in the Pearl River Delta].

    Science.gov (United States)

    Liao, Yi-Shan; Zhuo, Mu-Ning; Li, Ding-Qiang; Guo, Tai-Long

    2013-08-01

    In the Pearl Delta region, urban rivers have been seriously polluted, and the input of non-point source pollution materials, such as chemical oxygen demand (COD), into rivers cannot be neglected. During 2009-2010, the water qualities at eight different catchments in the Fenjiang River of Foshan city were monitored, and the COD loads for eight rivulet sewages were calculated in respect of different rainfall conditions. Interesting results were concluded in our paper. The rainfall and landuse type played important roles in the COD loading, with greater influence of rainfall than landuse type. Consequently, a COD loading formula was constructed that was defined as a function of runoff and landuse type that were derived SCS model and land use map. Loading of COD could be evaluated and predicted with the constructed formula. The mean simulation accuracy for single rainfall event was 75.51%. Long-term simulation accuracy was better than that of single rainfall. In 2009, the estimated COD loading and its loading intensity were 8 053 t and 339 kg x (hm2 x a)(-1), and the industrial land was regarded as the main source of COD pollution area. The severe non-point source pollution such as COD in Fenjiang River must be paid more attention in the future.

  16. Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China.

    Science.gov (United States)

    Zhu, Q D; Sun, J H; Hua, G F; Wang, J H; Wang, H

    2015-10-01

    Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB.

  17. Maximum power point tracking controller for PV systems using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Bahgat, A.B.G. [Cairo Univ. (Egypt). Faculty of Engineering; Helwa, N.H.; Ahmad, G.E.; El Shenawy, E.T. [National Research Center, Dokki, Cairo (Egypt). Solar Energy Dept.

    2005-07-01

    This paper presents a development and implementation of a PC-based maximum power point tracker (MPPT) for PV system using neural networks (NN). The system consists of a PV module via a MPPT supplying a dc motor that drives an air fan. The control algorithm is developed to use the artificial NN for detecting the optimal operating point under different operating conditions, then the control action gives the driving signals to the MPPT. A PC is used for data acquisition, running the control algorithm, data storage, as well as data display and analysis. The system has been implemented and tested under various operating conditions. The experimental results showed that the PV system with MPPT always tracks the peak power point of the PV module under various operating conditions. The MPPT transmits about 97% of the actual maximum power generated by the PV module. The MPPT not only increases the power from the PV module to the load, but also maintains longer operating periods for the PV system. The air velocity and the air mass flow rate of the mechanical load are increased considerably, due to the increase of the PV system power. It is also found that the increase in the output energy due to using the MPPT is about 45.2% for a clear sunny day. (Author)

  18. Investigating the effects of point source and nonpoint source pollution on the water quality of the East River (Dongjiang) in South China

    Science.gov (United States)

    Wu, Yiping; Chen, Ji

    2013-01-01

    Understanding the physical processes of point source (PS) and nonpoint source (NPS) pollution is critical to evaluate river water quality and identify major pollutant sources in a watershed. In this study, we used the physically-based hydrological/water quality model, Soil and Water Assessment Tool, to investigate the influence of PS and NPS pollution on the water quality of the East River (Dongjiang in Chinese) in southern China. Our results indicate that NPS pollution was the dominant contribution (>94%) to nutrient loads except for mineral phosphorus (50%). A comprehensive Water Quality Index (WQI) computed using eight key water quality variables demonstrates that water quality is better upstream than downstream despite the higher level of ammonium nitrogen found in upstream waters. Also, the temporal (seasonal) and spatial distributions of nutrient loads clearly indicate the critical time period (from late dry season to early wet season) and pollution source areas within the basin (middle and downstream agricultural lands), which resource managers can use to accomplish substantial reduction of NPS pollutant loadings. Overall, this study helps our understanding of the relationship between human activities and pollutant loads and further contributes to decision support for local watershed managers to protect water quality in this region. In particular, the methods presented such as integrating WQI with watershed modeling and identifying the critical time period and pollutions source areas can be valuable for other researchers worldwide.

  19. Control and Driving Methods for LED Based Intelligent Light Sources

    DEFF Research Database (Denmark)

    Beczkowski, Szymon

    of the diode is controlled either by varying the magnitude of the current or by driving the LED with a pulsed current and regulate the width of the pulse. It has been shown previously, that these two methods yield different effects on diode's efficacy and colour point. A hybrid dimming strategy has been...... proposed where two variable quantities control the intensity of the diode. This increases the controllability of the diode giving new optimisation possibilities. It has been shown that it is possible to compensate for temperature drift of white diode's colour point using hybrid dimming strategy. Also...

  20. Optimization of Control Points Number at Coordinate Measurements based on the Monte-Carlo Method

    Science.gov (United States)

    Korolev, A. A.; Kochetkov, A. V.; Zakharov, O. V.

    2018-01-01

    Improving the quality of products causes an increase in the requirements for the accuracy of the dimensions and shape of the surfaces of the workpieces. This, in turn, raises the requirements for accuracy and productivity of measuring of the workpieces. The use of coordinate measuring machines is currently the most effective measuring tool for solving similar problems. The article proposes a method for optimizing the number of control points using Monte Carlo simulation. Based on the measurement of a small sample from batches of workpieces, statistical modeling is performed, which allows one to obtain interval estimates of the measurement error. This approach is demonstrated by examples of applications for flatness, cylindricity and sphericity. Four options of uniform and uneven arrangement of control points are considered and their comparison is given. It is revealed that when the number of control points decreases, the arithmetic mean decreases, the standard deviation of the measurement error increases and the probability of the measurement α-error increases. In general, it has been established that it is possible to repeatedly reduce the number of control points while maintaining the required measurement accuracy.

  1. Study on upgrade on nuclear control related open source information website

    International Nuclear Information System (INIS)

    Kim, H. T.; Park, S. S.; Park, W. S.; Choi, Y. M.

    2002-01-01

    The open source information relevant to the nuclear control is regularly collected, analyzed, and published to the three web sites by the Technology Center for Nuclear Control (TCNC) of the Korea Atomic Energy Research Institute (KAERI). These web sites are world-wide, KAERI-wide, and TCNC-wide, respectively. We are to upgrade the KAERI-wide website to the access-controlled world-wide web site with some additional functionality. In this research, the current status of the three nuclear control related open source information websites managed by the TCNC was introduced and methods for upgrading the KAERI-wide open source information website and associated information security technology were reviewed

  2. Energy control of supercapacitor/fuel cell hybrid power source

    International Nuclear Information System (INIS)

    Payman, Alireza; Pierfederici, Serge; Meibody-Tabar, Farid

    2008-01-01

    This paper deals with a flatness based control principle in a hybrid system utilizing a fuel cell as a main power source and a supercapacitor as an auxiliary power source. The control strategy is based on regulation of the dc bus capacitor energy and, consequently, voltage regulation. The proposed control algorithm does not use a commutation algorithm when the operating mode changes with the load power variation and, thus, avoids chattering effects. Using the flatness based control method, the fuel cell dynamic and its delivered power is perfectly controlled, and the fuel cell can operate in a safe condition. In the hybrid system, the supercapacitor functions during transient energy delivery or during energy recovery situations. To validate the proposed method, the control algorithms are executed in dSPACE hardware, while analogical current loops regulators are employed in the experimental environment. The experimental results prove the validity of the proposed approach

  3. Maximum Power Point Tracking Control of Photovoltaic Systems: A Polynomial Fuzzy Model-Based Approach

    DEFF Research Database (Denmark)

    Rakhshan, Mohsen; Vafamand, Navid; Khooban, Mohammad Hassan

    2018-01-01

    This paper introduces a polynomial fuzzy model (PFM)-based maximum power point tracking (MPPT) control approach to increase the performance and efficiency of the solar photovoltaic (PV) electricity generation. The proposed method relies on a polynomial fuzzy modeling, a polynomial parallel......, a direct maximum power (DMP)-based control structure is considered for MPPT. Using the PFM representation, the DMP-based control structure is formulated in terms of SOS conditions. Unlike the conventional approaches, the proposed approach does not require exploring the maximum power operational point...

  4. Strengthening the control on radioactive sources - Cernavoda NPP operating experience

    International Nuclear Information System (INIS)

    Daian, I.; Simionov, V.

    2005-01-01

    This paper presents the national legal frame governing the radioactive source management, legislative requirements introduced during last years and current status of controlled radioactive sources program at Cernavoda NPP. Romania has only one nuclear power plant, Cernavoda NPP, equipped with five PHWR - CANDU-6 Canadian type reactors - with a 700 MW(e) gross capacity each, in different implementation stages. The legal representative of the nuclear power production sector in Romania is 'Nuclearelectrica' S.A. National Company (SNN). SNN is a governmental company controlled by the Ministry of Industry and Trade. The company has headquarters in Bucharest and three subsidiaries: - CNE-PROD Cernavoda (CNE-PROD), operating the Cernavoda NPP - Unit 1; - CNE-INVEST Cernavoda, in charge with the completion of Unit 2 and with the preservation of Units 3,4,5; - Nuclear Fuel Plant in Pitesti (FCN). Unit 1 is in commercial operation since December 2, 1996, Unit 2 is under construction (80% completed) and Units 3, 4, 5 are under preservation. The operation of Cernavoda NPP implies use of radioactive sources that may present a significant risk to health, property and the environment when control is lost. Within the last years CNCAN issued new regulations stating clear responsibilities for the different institutions involved in radioactive materials control programs. To manage radioactive sources in a safe way CNE-PROD established and revised the Controlled Radioactive Sources Program, as part of Station Radiation Protection Regulation, ensuring strict recording of the radioactive sources and their usage, ensuring physical and radiological security, protecting the personnel, members of the public and the environment from the hazards of ionizing radiation during the life cycle of the plant, including decommissioning. (authors)

  5. Strengthening the control on radioactive sources - Cernavoda NPP operating experience

    International Nuclear Information System (INIS)

    Daian, I.; Simionov, V.

    2005-01-01

    Full text: This paper presents the national legal frame governing the radioactive source management, legislative requirements introduced during last years and current status of controlled radioactive sources program at Cernavoda NPP. Romania has only one nuclear power plant, Cernavoda NPP, equipped with five PHWR - CANDU-6 Canadian type reactors - with a 700 MW(e) gross capacity each, in different implementation stages. The legal representative of the nuclear power production sector in Romania is 'Nuclearelectrica' S.A. National Company (SNN). SNN is a governmental company controlled by the Ministry of Industry and Trade. The company has headquarters in Bucharest and three subsidiaries: - CNE-PROD Cernavoda (CNE-PROD), operating the Cernavoda NPP - Unit 1; - CNE-INVEST Cernavoda, in charge with the completion of Unit 2 and with the preservation of Units 3,4,5; - Nuclear Fuel Plant in Pitesti (FCN). Unit 1 is in commercial operation since December 2, 1996, Unit 2 is under construction (80% completed) and Units 3, 4, 5 are under preservation. The operation of Cernavoda NPP implies use of radioactive sources that may present a significant risk to health, property and the environment when control is lost. Within the last years CNCAN issued new regulations stating clear responsibilities for the different institutions involved in radioactive materials control programs. To manage radioactive sources in a safe way CNE-PROD established and revised the Controlled Radioactive Sources Program, as part of Station Radiation Protection Regulation, ensuring strict recording of the radioactive sources and their usage, ensuring physical and radiological security, protecting the personnel, members of the public and the environment from the hazards of ionizing radiation during the life cycle of the plant. (authors)

  6. Microbial profile and critical control points during processing of 'robo ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... frying, surface fat draining, open-air cooling, and holding/packaging in polyethylene films during sales and distribution. The product was, however, classified under category III with respect to risk and the significance of monitoring and evaluation of quality using the hazard analysis critical control point.

  7. An optical system for controlling ion source parameters

    International Nuclear Information System (INIS)

    Zhang Baifang; Liu Zhenhao; Jiang Yi; Xu Zhengjia

    1999-01-01

    An optical control system used for adjusting the source's parameters of an ion separator is described. There are two slice microcomputers at HV terminal and the ground respectively. These microcomputers communicate each other with the full-duplex mode through two pieces of optical fiber, in which many parameters are time-share transmitted in the form of optical pulse. This system can stabilize the arc current and temperature, adjust and display all parameters and has safe-guard ability. At HV terminal, the optical coupling technique is used for connecting the CPU and the ion source, and at the ground the CPU can communicate with a control microcomputer

  8. Industrial point source CO2 emission strength estimation with aircraft measurements and dispersion modelling.

    Science.gov (United States)

    Carotenuto, Federico; Gualtieri, Giovanni; Miglietta, Franco; Riccio, Angelo; Toscano, Piero; Wohlfahrt, Georg; Gioli, Beniamino

    2018-02-22

    CO 2 remains the greenhouse gas that contributes most to anthropogenic global warming, and the evaluation of its emissions is of major interest to both research and regulatory purposes. Emission inventories generally provide quite reliable estimates of CO 2 emissions. However, because of intrinsic uncertainties associated with these estimates, it is of great importance to validate emission inventories against independent estimates. This paper describes an integrated approach combining aircraft measurements and a puff dispersion modelling framework by considering a CO 2 industrial point source, located in Biganos, France. CO 2 density measurements were obtained by applying the mass balance method, while CO 2 emission estimates were derived by implementing the CALMET/CALPUFF model chain. For the latter, three meteorological initializations were used: (i) WRF-modelled outputs initialized by ECMWF reanalyses; (ii) WRF-modelled outputs initialized by CFSR reanalyses and (iii) local in situ observations. Governmental inventorial data were used as reference for all applications. The strengths and weaknesses of the different approaches and how they affect emission estimation uncertainty were investigated. The mass balance based on aircraft measurements was quite succesful in capturing the point source emission strength (at worst with a 16% bias), while the accuracy of the dispersion modelling, markedly when using ECMWF initialization through the WRF model, was only slightly lower (estimation with an 18% bias). The analysis will help in highlighting some methodological best practices that can be used as guidelines for future experiments.

  9. Implementation and performance evaluation open-source controller for precision control of gripper

    Science.gov (United States)

    Lee, Seung-Yong; Ham, Un-Hyeong; Park, Young-Woo; Jung, Hak-Sang; Jung, Il-Kyun; Lim, Sun

    2017-12-01

    This paper proposes integrating gripper embedded operating system, which consist of external interface structure for sophisticated gripper control. This system has multiple functions that control the gripping module and measure the pose of the gripper body with respect to contact environment. A controller based on open source only for the gripper is developed and an external communication interface between robot controller and gripper controller is designed. An experimental environment for the fixed-cycle test consists of integrating magic gripper software system and hardware on commercial business. As a result, a deviation is measured approximately 2% and the system were verified for gripper control.

  10. Development of Remote Control and Interlock System for the PEFP Microwave Ion Source

    International Nuclear Information System (INIS)

    Song, Young Gi; Seol, Kyung Tae; Kwon, Hyeok Jung; Jang, Ji Ho; Cho, Yong Sub

    2011-01-01

    The control system for a microwave ion source as an isolated high voltage device is a main part of the PEFP distributed control system. The system is used to control two sets of microwave ion sources, the remote control and the interlock system. A VME system with an embedded Power PC CPU is used as main computer. The VME system is dedicated to control and monitoring of the ion source operation. An isolated control system has been designed and developed for remote control and monitoring of a microwave generator and various power supplies. As the source is placed on high voltage platform, optical fiber isolation has been used between the serial to optical fiber VME I/O board and the control system on the high voltage platform. These are connected through RS232 serial interface. A fast Ethernet is used to communicate between the microwave ion source control system and other control stations in the PEFP control system. EPICS toolkit is adopted to provide network programming and user interface by using EPICS Channel Access (CA)

  11. Statistical data evaluation in mobile gamma spectrometry. An optimisation of on-line search strategies in the scenario of lost point sources

    International Nuclear Information System (INIS)

    Hjerpe, T.; Samuelsson, C.

    1999-01-01

    There is a potential risk that hazardous radioactive sources could enter the environment, e.g. via satellite debris, smuggled radioactive goods or lost metal scrap. From a radiation protection point of view there is a need for rapid and reliable methods for locating and identifying sources. Car-borne and air-borne detector systems are suitable for the task. The condition in this work is a situation where the missing radionuclide is known, which is not an unlikely scenario. The possibility that the source is located near a road can be high, and thus motivating a car-borne spectrometer system. The main object is to optimise on-line statistical methods in order to achieve a high probability for locating point sources, or hot spots, and still have reasonably few false alarms from variations in the natural background radiation. Data were obtained from a car-borne 3 litres (NaI(Tl) detector and two point sources, located at various distances from the road. The nuclides used were 137 Cs and 131 I. Spectra were measured stationary on the road. From these measurements spectra we have reconstructed spectra applicable to different speed and sampling times; the time 3 seconds and 50 km/h are used in this work. The maximum distance a source can be located from the road and still be detected is estimated with four different statistical analysis methods. This distance is called the detection distance, DD. The method is applied on gross counts in the full energy peak window. For each method alarm thresholds has been calculated from background data obtained in Scania (Skaane), in the south of Sweden. The results show a 30-50% difference in DD's. With this semi-theoretical approach, the two sources could be detected from 250 m ( 137 Cs, 6GBq) and 200 m ( 131 I, 4GBq). (au)

  12. A method for untriggered time-dependent searches for multiple flares from neutrino point sources

    International Nuclear Information System (INIS)

    Gora, D.; Bernardini, E.; Cruz Silva, A.H.

    2011-04-01

    A method for a time-dependent search for flaring astrophysical sources which can be potentially detected by large neutrino experiments is presented. The method uses a time-clustering algorithm combined with an unbinned likelihood procedure. By including in the likelihood function a signal term which describes the contribution of many small clusters of signal-like events, this method provides an effective way for looking for weak neutrino flares over different time-scales. The method is sensitive to an overall excess of events distributed over several flares which are not individually detectable. For standard cases (one flare) the discovery potential of the method is worse than a standard time-dependent point source analysis with unknown duration of the flare by a factor depending on the signal-to-background level. However, for flares sufficiently shorter than the total observation period, the method is more sensitive than a time-integrated analysis. (orig.)

  13. A method for untriggered time-dependent searches for multiple flares from neutrino point sources

    Energy Technology Data Exchange (ETDEWEB)

    Gora, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institute of Nuclear Physics PAN, Cracow (Poland); Bernardini, E.; Cruz Silva, A.H. [Institute of Nuclear Physics PAN, Cracow (Poland)

    2011-04-15

    A method for a time-dependent search for flaring astrophysical sources which can be potentially detected by large neutrino experiments is presented. The method uses a time-clustering algorithm combined with an unbinned likelihood procedure. By including in the likelihood function a signal term which describes the contribution of many small clusters of signal-like events, this method provides an effective way for looking for weak neutrino flares over different time-scales. The method is sensitive to an overall excess of events distributed over several flares which are not individually detectable. For standard cases (one flare) the discovery potential of the method is worse than a standard time-dependent point source analysis with unknown duration of the flare by a factor depending on the signal-to-background level. However, for flares sufficiently shorter than the total observation period, the method is more sensitive than a time-integrated analysis. (orig.)

  14. Volatile organic compound emissions from the oil and natural gas industry in the Uinta Basin, Utah: point sources compared to ambient air composition

    Science.gov (United States)

    Warneke, C.; Geiger, F.; Edwards, P. M.; Dube, W.; Pétron, G.; Kofler, J.; Zahn, A.; Brown, S. S.; Graus, M.; Gilman, J.; Lerner, B.; Peischl, J.; Ryerson, T. B.; de Gouw, J. A.; Roberts, J. M.

    2014-05-01

    The emissions of volatile organic compounds (VOCs) associated with oil and natural gas production in the Uinta Basin, Utah were measured at a ground site in Horse Pool and from a NOAA mobile laboratory with PTR-MS instruments. The VOC compositions in the vicinity of individual gas and oil wells and other point sources such as evaporation ponds, compressor stations and injection wells are compared to the measurements at Horse Pool. High mixing ratios of aromatics, alkanes, cycloalkanes and methanol were observed for extended periods of time and short-term spikes caused by local point sources. The mixing ratios during the time the mobile laboratory spent on the well pads were averaged. High mixing ratios were found close to all point sources, but gas wells using dry-gas collection, which means dehydration happens at the well, were clearly associated with higher mixing ratios than other wells. Another large source was the flowback pond near a recently hydraulically re-fractured gas well. The comparison of the VOC composition of the emissions from the oil and natural gas wells showed that wet gas collection wells compared well with the majority of the data at Horse Pool and that oil wells compared well with the rest of the ground site data. Oil wells on average emit heavier compounds than gas wells. The mobile laboratory measurements confirm the results from an emissions inventory: the main VOC source categories from individual point sources are dehydrators, oil and condensate tank flashing and pneumatic devices and pumps. Raw natural gas is emitted from the pneumatic devices and pumps and heavier VOC mixes from the tank flashings.

  15. Geodetic Control Points, Benchmarks; Vertical elevation bench marks for monumented geodetic survey control points for which mean sea level elevations have been determined., Published in 1995, 1:24000 (1in=2000ft) scale, Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC State | GIS Inventory — Geodetic Control Points dataset current as of 1995. Benchmarks; Vertical elevation bench marks for monumented geodetic survey control points for which mean sea level...

  16. The advanced light source control system

    International Nuclear Information System (INIS)

    Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.; Young, J.

    1990-01-01

    The criteria for the design of a modern control system are discussed in the context of the special requirements for the control of the Advanced Light Source (ALS). This is followed by the description of the system being built, which has a number of special features. The emphasis has been placed on providing an extremely wide I/O and CPU bandwidth (greater than 120 Mbits/s and 1200 Mips, respectively) and on using commercially available hardware and software. The only major custom design item is the Intelligent Local Controller (ILC), of which about 600 will be used to interface to the hardware. The use of personal computers for the operator stations allows the use of a wealth of industrial standards for windows, languages and tools. (orig.)

  17. A New MPPT Control for Photovoltaic Panels by Instantaneous Maximum Power Point Tracking

    Science.gov (United States)

    Tokushima, Daiki; Uchida, Masato; Kanbei, Satoshi; Ishikawa, Hiroki; Naitoh, Haruo

    This paper presents a new maximum power point tracking control for photovoltaic (PV) panels. The control can be categorized into the Perturb and Observe (P & O) method. It utilizes instantaneous voltage ripples at PV panel output terminals caused by the switching of a chopper connected to the panel in order to identify the direction for the maximum power point (MPP). The tracking for the MPP is achieved by a feedback control of the average terminal voltage of the panel. Appropriate use of the instantaneous and the average values of the PV voltage for the separate purposes enables both the quick transient response and the good convergence with almost no ripples simultaneously. The tracking capability is verified experimentally with a 2.8 W PV panel under a controlled experimental setup. A numerical comparison with a conventional P & O confirms that the proposed control extracts much more power from the PV panel.

  18. Mathematic-Graphical Formalization of Switch Point Control Circuit Function

    Directory of Open Access Journals (Sweden)

    Juraj Zdansky

    2004-01-01

    Full Text Available This article describes authors designed method then enables mathematic – graphical formalization of system’s functional specification. The result of this method is algebraic system – finite automata that is written in transition table. This transition table is possible to overwrite to graphic form (state diagram or to mathematic form (transition and output function. This method is described by example of switch point control circuit.

  19. Revised accident source terms and control room habitability

    International Nuclear Information System (INIS)

    Lahti, G.P.; Hubner, R.S.; Johnson, W.J.; Schwartz, B.C.

    1993-01-01

    In April 1992, the NRC staff presented to the Commissioners the draft NUREG open-quotes Revised Accident Source Terms for Light-Water Nuclear Power Plants.close quotes This document is the culmination of more than ten years of NRC-sponsored research and represents the first change in the NRC's position on source terms since TID-14844 was issued in 1962. The purpose of this paper is to investigate the impact of the revised source terms on the current approach to analyzing control room habitability as required by 10 CFR 50. Sample calculations are presented that identify aspects of the model requiring clarification before the implementation of the revised source terms. 6 refs., 4 tabs

  20. Polar coordinated fuzzy controller based real-time maximum-power point control of photovoltaic system

    Energy Technology Data Exchange (ETDEWEB)

    Syafaruddin; Hiyama, Takashi [Department of Computer Science and Electrical Engineering of Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Karatepe, Engin [Department of Electrical and Electronics Engineering of Ege University, 35100 Bornova-Izmir (Turkey)

    2009-12-15

    It is crucial to improve the photovoltaic (PV) system efficiency and to develop the reliability of PV generation control systems. There are two ways to increase the efficiency of PV power generation system. The first is to develop materials offering high conversion efficiency at low cost. The second is to operate PV systems optimally. However, the PV system can be optimally operated only at a specific output voltage and its output power fluctuates under intermittent weather conditions. Moreover, it is very difficult to test the performance of a maximum-power point tracking (MPPT) controller under the same weather condition during the development process and also the field testing is costly and time consuming. This paper presents a novel real-time simulation technique of PV generation system by using dSPACE real-time interface system. The proposed system includes Artificial Neural Network (ANN) and fuzzy logic controller scheme using polar information. This type of fuzzy logic rules is implemented for the first time to operate the PV module at optimum operating point. ANN is utilized to determine the optimum operating voltage for monocrystalline silicon, thin-film cadmium telluride and triple junction amorphous silicon solar cells. The verification of availability and stability of the proposed system through the real-time simulator shows that the proposed system can respond accurately for different scenarios and different solar cell technologies. (author)

  1. 40 CFR 469.16 - Pretreatment standards for existing sources (PSES).

    Science.gov (United States)

    2010-07-01

    ... sources (PSES). 469.16 Section 469.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ELECTRICAL AND ELECTRONIC COMPONENTS POINT SOURCE CATEGORY Semiconductor... implement the solvent management plan approved by the control authority. ...

  2. A Look at the Future of Controlled-Source Seismology

    Science.gov (United States)

    Keller, G. R.; Klemperer, S.; Hole, J.; Snelson, C.

    2008-12-01

    Facilities like EarthScope and IRIS/PASSCAL offer a framework in which to re-assess the role of our highest- resolution geophysical tool, controlled-source seismology. This tool is effective in near surface studies that focus on the upper 100 m of the crust to studies that focus on Moho structure and the lithospheric mantle. IRIS has now existed for over two decades and has transformed the way in which passive-source seismology in particular is carried out. Progress over these two decades has led to major discoveries about continental architecture and evolution through the development of three-dimensional images of the upper mantle and lithosphere. Simultaneously the hydrocarbon exploration industry has mapped increasingly large fractions of our sedimentary basins in three-dimensions and at unprecedented resolution and fidelity. Thanks to the additional instruments in the EarthScope facility, a clear scientific need and opportunity exists to map, at similar resolution, all of the crust - the igneous/metamorphic basement, the non-petroliferous basins that contain the record of continental evolution, and the seismogenic faults and active volcanoes that are the principal natural hazards we face. Controlled-source seismology remains the fundamental technology behind exploration for all fossil fuels and many water resources, and as such is a multi-billion-dollar industry centered in the USA. Academic scientists are leaders in developing the algorithms to process the most advanced industry data, but lack the academic data sets to which to apply this technology. University and government controlled-source seismologists, and their students who will populate the exploration industry, are increasingly divorced from that industry by their reliance on sparse spatial recording of usually only a single-component of the wavefield, generated by even sparser seismic sources. However, if we can find the resources, the technology now exists to provide seismic images of immense

  3. A simplified computer code based on point Kernel theory for calculating radiation dose in packages of radioactive material

    International Nuclear Information System (INIS)

    1986-03-01

    A study on radiation dose control in packages of radioactive waste from nuclear facilities, hospitals and industries, such as sources of Ra-226, Co-60, Ir-192 and Cs-137, is presented. The MAPA and MAPAM computer codes, based on point Kernel theory for calculating doses of several source-shielding type configurations, aiming to assure the safe transport conditions for these sources, was developed. The validation of the code for point sources, using the values provided by NCRP, for the thickness of lead and concrete shieldings, limiting the dose at 100 Mrem/hr for several distances from the source to the detector, was carried out. The validation for non point sources was carried out, measuring experimentally radiation dose from packages developed by Brazilian CNEN/S.P. for removing the sources. (M.C.K.) [pt

  4. Power Controllability of Three-phase Converter with Unbalanced AC Source

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2013-01-01

    Three-phase DC-AC power converters suffer from power oscillation and overcurrentt problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... currents. In this work a new series of control strategies which utilize the zero-sequence components are proposed to enhance the power control ability under this adverse conditions. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC sources....

  5. SREM - WRS system module number 3348 for calculating the removal flux due to point, line or disc sources

    International Nuclear Information System (INIS)

    Grimstone, M.J.

    1978-06-01

    The WRS Modular Programming System has been developed as a means by which programmes may be more efficiently constructed, maintained and modified. In this system a module is a self-contained unit typically composed of one or more Fortran routines, and a programme is constructed from a number of such modules. This report describes one WRS module, the function of which is to calculate the uncollided flux and first-collision source from a disc source in a slab geometry system, a line source at the centre of a cylindrical system or a point source at the centre of a spherical system. The information given in this manual is of use both to the programmer wishing to incorporate the module in a programme, and to the user of such a programme. (author)

  6. Modeling generalized interline power-flow controller (GIPFC using 48-pulse voltage source converters

    Directory of Open Access Journals (Sweden)

    Amir Ghorbani

    2018-05-01

    Full Text Available Generalized interline power-flow controller (GIPFC is one of the voltage-source controller (VSC-based flexible AC transmission system (FACTS controllers that can independently regulate the power-flow over each transmission line of a multiline system. This paper presents the modeling and performance analysis of GIPFC based on 48-pulsed voltage-source converters. This paper deals with a cascaded multilevel converter model, which is a 48-pulse (three levels voltage source converter. The voltage source converter described in this paper is a harmonic neutralized, 48-pulse GTO converter. The GIPFC controller is based on d-q orthogonal coordinates. The algorithm is verified using simulations in MATLAB/Simulink environment. Comparisons between unified power flow controller (UPFC and GIPFC are also included. Keywords: Generalized interline power-flow controller (GIPFC, Voltage source converter (VCS, 48-pulse GTO converter

  7. Free-time and fixed end-point multi-target optimal control theory: Application to quantum computing

    International Nuclear Information System (INIS)

    Mishima, K.; Yamashita, K.

    2011-01-01

    Graphical abstract: The two-state Deutsch-Jozsa algortihm used to demonstrate the utility of free-time and fixed-end point multi-target optimal control theory. Research highlights: → Free-time and fixed-end point multi-target optimal control theory (FRFP-MTOCT) was constructed. → The features of our theory include optimization of the external time-dependent perturbations with high transition probabilities, that of the temporal duration, the monotonic convergence, and the ability to optimize multiple-laser pulses simultaneously. → The advantage of the theory and a comparison with conventional fixed-time and fixed end-point multi-target optimal control theory (FIFP-MTOCT) are presented by comparing data calculated using the present theory with those published previously [K. Mishima, K. Yamashita, Chem. Phys. 361 (2009) 106]. → The qubit system of our interest consists of two polar NaCl molecules coupled by dipole-dipole interaction. → The calculation examples show that our theory is useful for minor adjustment of the external fields. - Abstract: An extension of free-time and fixed end-point optimal control theory (FRFP-OCT) to monotonically convergent free-time and fixed end-point multi-target optimal control theory (FRFP-MTOCT) is presented. The features of our theory include optimization of the external time-dependent perturbations with high transition probabilities, that of the temporal duration, the monotonic convergence, and the ability to optimize multiple-laser pulses simultaneously. The advantage of the theory and a comparison with conventional fixed-time and fixed end-point multi-target optimal control theory (FIFP-MTOCT) are presented by comparing data calculated using the present theory with those published previously [K. Mishima, K. Yamashita, Chem. Phys. 361, (2009), 106]. The qubit system of our interest consists of two polar NaCl molecules coupled by dipole-dipole interaction. The calculation examples show that our theory is useful for minor

  8. Control-structure interaction in precision pointing servo loops

    Science.gov (United States)

    Spanos, John T.

    1989-01-01

    The control-structure interaction problem is addressed via stability analysis of a generic linear servo loop model. With the plant described by the rigid body mode and a single elastic mode, structural flexibility is categorized into one of three types: (1) appendage, (2) in-the-loop minimum phase, and (3) in-the-loop nonminimum phase. Closing the loop with proportional-derivative (PD) control action and introducing sensor roll-off dynamics in the feedback path, stability conditions are obtained. Trade studies are conducted with modal frequency, modal participation, modal damping, loop bandwidth, and sensor bandwidth treated as free parameters. Results indicate that appendage modes are most likely to produce instability if they are near the sensor rolloff, whereas in-the-loop modes are most dangerous near the loop bandwidth. The main goal of this paper is to provide a fundamental understanding of the control-structure interaction problem so that it may benefit the design of complex spacecraft and pointing system servo loops. In this framework, the JPL Pathfinder gimbal pointer is considered as an example.

  9. Biosolid stockpiles are a significant point source for greenhouse gas emissions.

    Science.gov (United States)

    Majumder, Ramaprasad; Livesley, Stephen J; Gregory, David; Arndt, Stefan K

    2014-10-01

    The wastewater treatment process generates large amounts of sewage sludge that are dried and then often stored in biosolid stockpiles in treatment plants. Because the biosolids are rich in decomposable organic matter they could be a significant source for greenhouse gas (GHG) emissions, yet there are no direct measurements of GHG from stockpiles. We therefore measured the direct emissions of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) on a monthly basis from three different age classes of biosolid stockpiles at the Western Treatment Plant (WTP), Melbourne, Australia, from December 2009 to November 2011 using manual static chambers. All biosolid stockpiles were a significant point source for CH4 and N2O emissions. The youngest biosolids (nitrate and ammonium concentration. We also modeled CH4 emissions based on a first order decay model and the model based estimated annual CH4 emissions were higher as compared to the direct field based estimated annual CH4 emissions. Our results indicate that labile organic material in stockpiles is decomposed over time and that nitrogen decomposition processes lead to significant N2O emissions. Carbon decomposition favors CO2 over CH4 production probably because of aerobic stockpile conditions or CH4 oxidation in the outer stockpile layers. Although the GHG emission rate decreased with biosolid age, managers of biosolid stockpiles should assess alternate storage or uses for biosolids to avoid nutrient losses and GHG emissions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Supplementary control points for reactor shutdown without access to the main control room (International Electrotechnical Commission Standard Publication 965:1989)

    International Nuclear Information System (INIS)

    Kubalek, J.; Hajek, B.

    1993-01-01

    This standard establishes the requirements for supplementary Control Points provided to enable the operating staff to shut down the reactor and maintain the plant in a safe shut-down condition when the main control room is no longer available. This standard covers the functional selection, design and organization of the man/machine interface. It also establishes requirements for procedures which systematically verify and validate the functional design of supplementary control points. The requirements reflect the application of human engineering principles as they apply to man/machine interface. This standard does not cover special emergency response centres (e.g. a Technical Support Centre). It also does not include the detailed equipment design. Unavailability of the main control room controls due to intentionally man-induced events is not considered

  11. Draught regulator with control flap lowers dew point, keeps stacks dry

    Energy Technology Data Exchange (ETDEWEB)

    Dreizler, U.; Dreizler, W.

    1982-11-30

    Draught regulators for auxiliary air are particularly important in older stacks operated with new boilers and burners. Owing to better ventilation during burner operation and standstill, the dew point of flue gases will be lowered so that water vapour condensation will be prevented. Postfitting of draught regulators will also help in stacks already damaged by condensation water. The draught regulator has a control flap for better control of auxiliary air supply.

  12. Seismic explosion sources on an ice cap

    DEFF Research Database (Denmark)

    Shulgin, Alexey; Thybo, Hans

    2015-01-01

    crustal model can be modelled. A crucial challenge for applying the technique is to control the sources. Here, we present data that describe the efficiency of explosive sources in the ice cover. Analysis of the data shows, that the ice cap traps a significant amount of energy, which is observed......Controlled source seismic investigation of crustal structure below ice covers is an emerging technique. We have recently conducted an explosive refraction/wide-angle reflection seismic experiment on the ice cap in east-central Greenland. The data-quality is high for all shot points and a full...

  13. Control of orphan sources. Import to and transport through Slovenia

    International Nuclear Information System (INIS)

    Cesarek, J.; Vokal Nemec, B.

    2007-01-01

    Orphan sources are radioactive sources which are not under regulatory control, either because they have never been under regulatory control, or because they have been abandoned, lost, misplaced, stolen or transferred without proper authorisation. The issue of orphan sources is not a new one but the situation has been highlighted more and more in the last ten years. One of the most important international milestones in this regard was the conference in Dijon, France in 1998. The orphan sources have become an international problem due to steady increase in international trade which made impossible to control every transfer of goods between countries. Shipments of metal scrap, either national or international, could comprise orphan sources which had come into metal stream. The consequences of such events vary greatly: from contaminated metal just above exemption levels to a melting of volatile radionuclides of significant activity which may cause enormous remediation costs. In addition, the phenomenon of deliberate abuse of nuclear material and radioactive material or previous accidents with found orphan sources worldwide and fatalities have made this issue even more provoking. In Slovenia, no such drastic events have occurred so far. Since 1991 there have been a few meltings of cobalt-60 sources with only economic impact. On several occasions, Italy - the country with strict import control - has detected elevated radiation and denied shipments of scrap metal. They had originated either from Slovenia or from other countries, mostly from former Yugoslav republics. The Slovenian experience shows that majority of cases is related to import of scrap metal in Slovenia or to transit of such material through Slovenia. These orphan sources have originated from past industrial activities or have been under no or weak regulatory control in their countries of origin. In order to prevent inadvertent movement and illicit trafficking of nuclear material and radioactive sources some

  14. A Survey of Open-Source UAV Flight Controllers and Flight Simulators

    DEFF Research Database (Denmark)

    Ebeid, Emad Samuel Malki; Skriver, Martin; Terkildsen, Kristian Husum

    2018-01-01

    , which are all tightly linked to the UAV flight controller hardware and software. The lack of standardization of flight controller architectures and the use of proprietary closed-source flight controllers on many UAV platforms, however, complicates this work: solutions developed for one flight controller...... may be difficult to port to another without substantial extra development and testing. Using open-source flight controllers mitigates some of these challenges and enables other researchers to validate and build upon existing research. This paper presents a survey of the publicly available open...

  15. Adaptive Control for Buck Power Converter Using Fixed Point Inducting Control and Zero Average Dynamics Strategies

    Science.gov (United States)

    Hoyos Velasco, Fredy Edimer; García, Nicolás Toro; Garcés Gómez, Yeison Alberto

    In this paper, the output voltage of a buck power converter is controlled by means of a quasi-sliding scheme. The Fixed Point Inducting Control (FPIC) technique is used for the control design, based on the Zero Average Dynamics (ZAD) strategy, including load estimation by means of the Least Mean Squares (LMS) method. The control scheme is tested in a Rapid Control Prototyping (RCP) system based on Digital Signal Processing (DSP) for dSPACE platform. The closed loop system shows adequate performance. The experimental and simulation results match. The main contribution of this paper is to introduce the load estimator by means of LMS, to make ZAD and FPIC control feasible in load variation conditions. In addition, comparison results for controlled buck converter with SMC, PID and ZAD-FPIC control techniques are shown.

  16. Design of Neutral-Point Voltage Controller of a Three-level NPC Inverter with Small DC-Link Capacitors

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, S.

    2013-01-01

    A Neutral-Point-Clamped (NPC) three-level inverter with small dc-link capacitors is presented in this paper. The inverter requires zero average neutral-point current for stable neutral-point voltage. The small dc-link capacitors may not maintain capacitor voltage balance, even with zero neutral......-point voltage control on the basis of the continuous model. The design method for optimum performance is discussed. The implementation of the proposed modulation strategy and the controller is very simple. The controller is implemented in a 7.5 kW induction machine based drive with only 14 ìF dc-link capacitors...

  17. Regulatory control and safety of radiation and radioactive sources in Bangladesh

    International Nuclear Information System (INIS)

    Mollah, A.S.

    2001-01-01

    The application of ionizing radiation and radioactive sources in different fields such as, medicine, industry, agriculture, research and teaching is constantly increasing in Bangladesh. Any system enacted to control exposure to ionizing radiation has as primary objective the protection of health of people against the deleterious effects of radiation. Establishing the appropriate level of radiological protection and safety of radiation sources used in practice or intervention attains this objective. The regulatory program governing the safe use of radioactive and radiation sources in Bangladesh is based on the legislation enacted as Nuclear Safety and Radiation Control (NSRC) Act-93 and NSRC Rules-97 and its implementation by the competent authority. The radiation control infrastructures and procedure are described as well as their functioning for the implementation of relevant activities such as licensing, regular inspection, personal dose monitoring, emergency preparedness, etc. The issue of security of radiation source is dealt in close relation with the preparation and use of the inventory of all radiation sources in the country

  18. End point control of an actinide precipitation reactor

    International Nuclear Information System (INIS)

    Muske, K.R.

    1997-01-01

    The actinide precipitation reactors in the nuclear materials processing facility at Los Alamos National Laboratory are used to remove actinides and other heavy metals from the effluent streams generated during the purification of plutonium. These effluent streams consist of hydrochloric acid solutions, ranging from one to five molar in concentration, in which actinides and other metals are dissolved. The actinides present are plutonium and americium. Typical actinide loadings range from one to five grams per liter. The most prevalent heavy metals are iron, chromium, and nickel that are due to stainless steel. Removal of these metals from solution is accomplished by hydroxide precipitation during the neutralization of the effluent. An end point control algorithm for the semi-batch actinide precipitation reactors at Los Alamos National Laboratory is described. The algorithm is based on an equilibrium solubility model of the chemical species in solution. This model is used to predict the amount of base hydroxide necessary to reach the end point of the actinide precipitation reaction. The model parameters are updated by on-line pH measurements

  19. Assessment of Non-Point Source Total Phosphorus Pollution from Different Land Use and Soil Types in a Mid-High Latitude Region of China

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    2016-11-01

    cultivated land. This has important implications for future agricultural management and non-point source control in this agricultural area of the mid-high latitude region.

  20. Interior Point Methods on GPU with application to Model Predictive Control

    DEFF Research Database (Denmark)

    Gade-Nielsen, Nicolai Fog

    The goal of this thesis is to investigate the application of interior point methods to solve dynamical optimization problems, using a graphical processing unit (GPU) with a focus on problems arising in Model Predictice Control (MPC). Multi-core processors have been available for over ten years now...... software package called GPUOPT, available under the non-restrictive MIT license. GPUOPT includes includes a primal-dual interior-point method, which supports both the CPU and the GPU. It is implemented as multiple components, where the matrix operations and solver for the Newton directions is separated...

  1. The equilibrium point hypothesis and its application to speech motor control.

    Science.gov (United States)

    Perrier, P; Ostry, D J; Laboissière, R

    1996-04-01

    In this paper, we address a number of issues in speech research in the context of the equilibrium point hypothesis of motor control. The hypothesis suggests that movements arise from shifts in the equilibrium position of the limb or the speech articulator. The equilibrium is a consequence of the interaction of central neural commands, reflex mechanisms, muscle properties, and external loads, but it is under the control of central neural commands. These commands act to shift the equilibrium via centrally specified signals acting at the level of the motoneurone (MN) pool. In the context of a model of sagittal plane jaw and hyoid motion based on the lambda version of the equilibrium point hypothesis, we consider the implications of this hypothesis for the notion of articulatory targets. We suggest that simple linear control signals may underlie smooth articulatory trajectories. We explore as well the phenomenon of intraarticulator coarticulation in jaw movement. We suggest that even when no account is taken of upcoming context, that apparent anticipatory changes in movement amplitude and duration may arise due to dynamics. We also present a number of simulations that show in different ways how variability in measured kinematics can arise in spite of constant magnitude speech control signals.

  2. Development of safe mechanism for surgical robots using equilibrium point control method.

    Science.gov (United States)

    Park, Shinsuk; Lim, Hokjin; Kim, Byeong-sang; Song, Jae-bok

    2006-01-01

    This paper introduces a novel mechanism for surgical robotic systems to generate human arm-like compliant motion. The mechanism is based on the idea of the equilibrium point control hypothesis which claims that multi-joint limb movements are achieved by shifting the limbs' equilibrium positions defined by neuromuscular activity. The equilibrium point control can be implemented on a robot manipulator by installing two actuators at each joint of the manipulator, one to control the joint position, and the other to control the joint stiffness. This double-actuator mechanism allows us to arbitrarily manipulate the stiffness (or impedance) of a robotic manipulator as well as its position. Also, the force at the end-effector can be estimated based on joint stiffness and joint angle changes without using force transducers. A two-link manipulator and a three-link manipulator with the double-actuator units have been developed, and experiments and simulation results show the potential of the proposed approach. By creating the human arm-like behavior, this mechanism can improve the performance of robot manipulators to execute stable and safe movement in surgical environments by using a simple control scheme.

  3. Analog Fixed Maximum Power Point Control for a PWM Step-downConverter for Water Pumping Installations

    DEFF Research Database (Denmark)

    Beltran, H.; Perez, E.; Chen, Zhe

    2009-01-01

    This paper describes a Fixed Maximum Power Point analog control used in a step-down Pulse Width Modulated power converter. The DC/DC converter drives a DC motor used in small water pumping installations, without any electric storage device. The power supply is provided by PV panels working around....... The proposed Optimal Power Point fix voltage control system is analyzed in comparison to other complex controls....... their maximum power point, with a fixed operating voltage value. The control circuit implementation is not only simple and cheap, but also robust and reliable. System protections and adjustments are also proposed. Simulations and hardware are reported in the paper for a 150W water pumping application system...

  4. Carbon Dioxide Capture and Separation Techniques for Gasification-based Power Generation Point Sources

    Energy Technology Data Exchange (ETDEWEB)

    Pennline, H.W.; Luebke, D.R.; Jones, K.L.; Morsi, B.I. (Univ. of Pittsburgh, PA); Heintz, Y.J. (Univ. of Pittsburgh, PA); Ilconich, J.B. (Parsons)

    2007-06-01

    The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and reduced costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (post-combustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle or IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Pertaining to another separation technology, fabrication techniques and mechanistic studies for membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. Finally, dry, regenerable processes based on sorbents are additional techniques for CO2 capture from fuel gas. An overview of these novel techniques is presented along with a research progress status of technologies related to membranes and physical solvents.

  5. Evaluation of the leap motion controller as a new contact-free pointing device.

    Science.gov (United States)

    Bachmann, Daniel; Weichert, Frank; Rinkenauer, Gerhard

    2014-12-24

    This paper presents a Fitts' law-based analysis of the user's performance in selection tasks with the Leap Motion Controller compared with a standard mouse device. The Leap Motion Controller (LMC) is a new contact-free input system for gesture-based human-computer interaction with declared sub-millimeter accuracy. Up to this point, there has hardly been any systematic evaluation of this new system available. With an error rate of 7.8% for the LMC and 2.8% for the mouse device, movement times twice as large as for a mouse device and high overall effort ratings, the Leap Motion Controller's performance as an input device for everyday generic computer pointing tasks is rather limited, at least with regard to the selection recognition provided by the LMC.

  6. Search for cosmic γ-point sources above 20 TeV with the HEGRA detector fields

    International Nuclear Information System (INIS)

    Prahl, J.

    1999-01-01

    The topic of this thesis is the search for point sources of high energy γ-rays (above 20 TeV) during the time interval from December 1993 until September 1995 with the HEGRA scintillator and AIROBICC arrays. The main aim is to exploit the available data as complete as possible in order to achieve a maximum in sensitivity. A thorough MtCarlo simulation of the registered events from the cosmic-ray-induced air showers allows for the use of all acquired events [de

  7. Science, information, technology, and the changing character of public policy in non-point source pollution

    Science.gov (United States)

    King, John L.; Corwin, Dennis L.

    Information technologies are already delivering important new capabilities for scientists working on non-point source (NPS) pollution in the vadose zone, and more are expected. This paper focuses on the special contributions of modeling and network communications for enhancing the effectiveness of scientists in the realm of policy debates regarding NPS pollution mitigation and abatement. The discussion examines a fundamental shift from a strict regulatory strategy of pollution control characterized by a bureaucratic/technical alliance during the period through the 1970's and early 1980's, to a more recently evolving paradigm of pluralistic environmental management. The role of science and scientists in this shift is explored, with special attention to the challenges facing scientists working in NPS pollution in the vadose zone. These scientists labor under a special handicap in the evolving model because their scientific tools are often times incapable of linking NPS pollution with individuals responsible for causing it. Information can facilitate the effectiveness of these scientists in policy debates, but not under the usual assumptions in which scientific truth prevails. Instead, information technology's key role is in helping scientists shape the evolving discussion of trade-offs and in bringing citizens and policymakers closer to the routine work of scientists.

  8. Three-level grid-connected photovoltaic inverter with maximum power point tracking

    International Nuclear Information System (INIS)

    Tsang, K.M.; Chan, W.L.

    2013-01-01

    Highlight: ► This paper reports a novel 3-level grid connected photovoltaic inverter. ► The inverter features maximum power point tracking and grid current shaping. ► The inverter can be acted as an active filter and a renewable power source. - Abstract: This paper presents a systematic way of designing control scheme for a grid-connected photovoltaic (PV) inverter featuring maximum power point tracking (MPPT) and grid current shaping. Unlike conventional design, only four power switches are required to achieve three output levels and it is not necessary to use any phase-locked-loop circuitry. For the proposed scheme, a simple integral controller has been designed for the tracking of the maximum power point of a PV array based on an improved extremum seeking control method. For the grid-connected inverter, a current loop controller and a voltage loop controller have been designed. The current loop controller is designed to shape the inverter output current while the voltage loop controller can maintain the capacitor voltage at a certain level and provide a reference inverter output current for the PV inverter without affecting the maximum power point of the PV array. Experimental results are included to demonstrate the effectiveness of the tracking and control scheme.

  9. Two- and three-particle interference correlations of identical bosons and fermions with close momenta in the model of independent point-like sources

    International Nuclear Information System (INIS)

    Lyuboshits, V.L.

    1991-01-01

    Interference correlations introduced between identical particles with close momenta by the effect of Bose or Fermi statistics are discussed. Relations describing two- and three-particle correlations of identical bosons and fermions with arbitrary spin and arbitrary spin polarization are obtained on the basis of the model of independent single-particle point-like sources. The general structure of the dependence of narrow two- and three-particle correlations on the difference of the four-momenta in the presence of several groups of single-particle sources with different space-time distributions is analyzed. The idea of many-particle point sources of identical bosons is introduced. The suppression of two- and three-particle interference correlations between identical π mesons under conditions when one or several many-particle sources are added to a system of randomly distributed independent single-particle sources is studied. It is shown that if the multiplicities of the particles emitted by the sources are distributed according to the Poisson law, the present results agree with the relations obtained by means of the formalism of coherent states. This agreement also holds in the limit of very large multiplicities with any distribution laws

  10. Dynamic droop scheme considering effect of intermittent renewable energy source

    DEFF Research Database (Denmark)

    Wang, Yanbo; Chen, Zhe; Deng, Fujin

    2016-01-01

    This paper presents a dynamic droop control scheme for islanded microgrids dominated by intermittent renewable energy sources, which is able to perform desirable power sharing in the presence of renewable energy source fluctuation. First, allowable maximum power points of wind generator and PV...... flexibility and effectiveness in the presence of the renewable energy sources fluctuation....... controller of each DG unit is activated through local logic variable inferred by wind speed and solar insolation information. Simulation results are given for validating the droop control scheme. The proposed dynamic droop scheme preserves the advantage of conventional droop control method, and provides...

  11. Supercritical CO2 Brayton cycle compression and control near the critical point

    International Nuclear Information System (INIS)

    Wright, S. A.; Fuller, R.; Noall, J.; Radel, R.; Vernon, M. E.; Pickard, P. S.

    2008-01-01

    This report describes the supercritical compression and control issues, the analysis, and the measured test results of a small-scale supercritical CO 2 (S-CO 2 ) compression test-loop. The test loop was developed by Sandia and is described in a companion paper in this conference. The results of these experiments will for the first time evaluate and experimentally demonstrate supercritical compression and the required compressor inlet control approaches on an appropriate scale in a series of test loops at Sandia National Laboratories. The Sandia effort is focused on the main compressor of a supercritical Brayton loop while a separate DOE Gen lV program focus is on studying similar behavior in re-compression Brayton cycles that have dual compressors. One of the main goals of this program is to develop and demonstrate the ability to design, operate, and control the supercritical compression process near the critical point due to highly non-linear behavior near this point. This Sandia supercritical test-loop uses a 50 kW radial compressor to pump supercritical CO 2 (S-CO 2 ) through an orifice and through a water-cooled gas-chiller. At the design point the compressor flow rate is 3.5 kg/s, the inlet pressure is 7, 690 kPa, the pressure ratio is 1.8, the inlet temperature is 305 K, and the shaft speed is 75, 000 rpm. The purpose of the loop is to study the compression and control issues near the critical point. To study compression we intend to compare the design code predictions for efficiency and change in enthalpy (or pressure ratio / head) of the radial compressor with the measured results from actual tests. In the tests the inlet flow, temperature, and pressure, will be varied around the critical point of CO 2 (Tc=304.2 K, and Pc=7.377 MPa). To study control, the test loop will use a variety of methods including inventory control, shaft speed control, and cooling water flow rate, and cooling water temperature control methods to set the compressor inlet temperature

  12. Simulation on Change Law of Runoff, Sediment and Non-point Source Nitrogen and Phosphorus Discharge under Different Land uses Based on SWAT Model: A Case Study of Er hai Lake Small Watershed

    Science.gov (United States)

    Tong, Xiao Xia; Lai Cui, Yuan; Chen, Man Yu; Hu, Bo; Xu, Wen Sheng

    2018-05-01

    The Er yuan watershed of Er hai district is chosen as the research area, the law of runoff and sediment and non-point source nitrogen and phosphorus discharges under different land uses during 2001 to 2014 are simulated based on SWAT model. Results of simulation indicate that the order of total runoff yield of different land use type from high to low is grassland, paddy fields, dry land. Specifically, the order of surface runoff yield from high to low is paddy fields, dry land, grassland, the order of lateral runoff yield from high to low is paddy fields, dry land, grassland, the order of groundwater runoff yield from high to low is grassland, paddy fields, dry land. The orders of sediment and nitrogen and phosphorus yield per unit area of different land use type are the same, grassland> paddy fields> dry land. It can be seen, nitrogen and phosphorus discharges from paddy fields and dry land are the main sources of agricultural non-point pollution of the irrigated area. Therefore, reasonable field management measures which can decrease the discharge of nitrogen and phosphorus of paddy fields and dry land are the key to agricultural non-point source pollution prevention and control.

  13. [Sacroiliac joint injury treated with oblique insertion at anatomical points: a randomized controlled trial].

    Science.gov (United States)

    Kuang, Jiayi; Li, Yuxuan; He, Yufeng; Gan, Lin; Wang, Aiming; Chen, Yanhua; Li, Xiaoting; Guo, Lin; Tang, Rongjun

    2016-04-01

    To compare the effects of oblique insertion at anatomical points and conventional acupuncture for sacroiliac joint injury. Eighty patients were randomly divided into an observation group and a control group, 40 cases in each one. In the observation group, oblique insertion therapy at anatomical points was used, and the 9 points of equal division (anatomical points) marked by palpating the anatomical symbol were treated as the insertion acupoints. In the control group, conventional acupuncture was applied, and perpendicular insertion was adopted at Huantiao (GB 30), Zhibian (BL 54) and Weizhong (BL 40), etc. In the two groups, the! treatment was given once a day and 5 times per week. Ten treatments were made into one course and two courses were required. The clinical effects, the changes of visual analogue scale (VAS) and Oswestry dysfunctional index. (ODI) before and after treatment were observed in the two groups. The total effective rate of the observation group was 90.0% (36/40), which was better than 72.5% (29/40) of the control group (P sacroiliac joint injury is superior to that of conventional acupuncture, which can effectively relieve pain and improve the disfunction.

  14. 40 CFR 469.26 - Pretreatment standards for existing sources (PSES).

    Science.gov (United States)

    2010-07-01

    ... sources (PSES). 469.26 Section 469.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ELECTRICAL AND ELECTRONIC COMPONENTS POINT SOURCE CATEGORY Electronic... (d) of this regulation must implement the solvent management plan approved by the control authority...

  15. A source-controlled data center network model.

    Science.gov (United States)

    Yu, Yang; Liang, Mangui; Wang, Zhe

    2017-01-01

    The construction of data center network by applying SDN technology has become a hot research topic. The SDN architecture has innovatively separated the control plane from the data plane which makes the network more software-oriented and agile. Moreover, it provides virtual multi-tenancy, effective scheduling resources and centralized control strategies to meet the demand for cloud computing data center. However, the explosion of network information is facing severe challenges for SDN controller. The flow storage and lookup mechanisms based on TCAM device have led to the restriction of scalability, high cost and energy consumption. In view of this, a source-controlled data center network (SCDCN) model is proposed herein. The SCDCN model applies a new type of source routing address named the vector address (VA) as the packet-switching label. The VA completely defines the communication path and the data forwarding process can be finished solely relying on VA. There are four advantages in the SCDCN architecture. 1) The model adopts hierarchical multi-controllers and abstracts large-scale data center network into some small network domains that has solved the restriction for the processing ability of single controller and reduced the computational complexity. 2) Vector switches (VS) developed in the core network no longer apply TCAM for table storage and lookup that has significantly cut down the cost and complexity for switches. Meanwhile, the problem of scalability can be solved effectively. 3) The SCDCN model simplifies the establishment process for new flows and there is no need to download flow tables to VS. The amount of control signaling consumed when establishing new flows can be significantly decreased. 4) We design the VS on the NetFPGA platform. The statistical results show that the hardware resource consumption in a VS is about 27% of that in an OFS.

  16. A source-controlled data center network model

    Science.gov (United States)

    Yu, Yang; Liang, Mangui; Wang, Zhe

    2017-01-01

    The construction of data center network by applying SDN technology has become a hot research topic. The SDN architecture has innovatively separated the control plane from the data plane which makes the network more software-oriented and agile. Moreover, it provides virtual multi-tenancy, effective scheduling resources and centralized control strategies to meet the demand for cloud computing data center. However, the explosion of network information is facing severe challenges for SDN controller. The flow storage and lookup mechanisms based on TCAM device have led to the restriction of scalability, high cost and energy consumption. In view of this, a source-controlled data center network (SCDCN) model is proposed herein. The SCDCN model applies a new type of source routing address named the vector address (VA) as the packet-switching label. The VA completely defines the communication path and the data forwarding process can be finished solely relying on VA. There are four advantages in the SCDCN architecture. 1) The model adopts hierarchical multi-controllers and abstracts large-scale data center network into some small network domains that has solved the restriction for the processing ability of single controller and reduced the computational complexity. 2) Vector switches (VS) developed in the core network no longer apply TCAM for table storage and lookup that has significantly cut down the cost and complexity for switches. Meanwhile, the problem of scalability can be solved effectively. 3) The SCDCN model simplifies the establishment process for new flows and there is no need to download flow tables to VS. The amount of control signaling consumed when establishing new flows can be significantly decreased. 4) We design the VS on the NetFPGA platform. The statistical results show that the hardware resource consumption in a VS is about 27% of that in an OFS. PMID:28328925

  17. Hardware-accelerated Point Generation and Rendering of Point-based Impostors

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas

    2005-01-01

    This paper presents a novel scheme for generating points from triangle models. The method is fast and lends itself well to implementation using graphics hardware. The triangle to point conversion is done by rendering the models, and the rendering may be performed procedurally or by a black box API....... I describe the technique in detail and discuss how the generated point sets can easily be used as impostors for the original triangle models used to create the points. Since the points reside solely in GPU memory, these impostors are fairly efficient. Source code is available online....

  18. First combined search for neutrino point-sources in the southern sky with the ANTARES and IceCube neutrino telescopes

    Directory of Open Access Journals (Sweden)

    Barrios-Martí J.

    2016-01-01

    Full Text Available A search for cosmic neutrino point-like sources using the ANTARES and IceCube neutrino telescopes over the Southern Hemisphere is presented. The ANTARES data were collected between January 2007 and December 2012, whereas the IceCube data ranges from April 2008 to May 2011. An unbinned maximum likelihood method is used to search for a localized excess of muon events in the southern sky assuming an E−2 neutrino source spectrum. A search over a pre-selected list of candidate sources has also been carried out for different source assumptions: spectral indices of 2.0 and 2.5, and energy cutoffs of 1 PeV, 300 TeV and 100 TeV. No significant excess over the background has been found, and upper limits for the candidate sources are presented compared to the individual experiments.

  19. Seafood safety: economics of hazard analysis and Critical Control Point (HACCP) programmes

    National Research Council Canada - National Science Library

    Cato, James C

    1998-01-01

    .... This document on economic issues associated with seafood safety was prepared to complement the work of the Service in seafood technology, plant sanitation and Hazard Analysis Critical Control Point (HACCP) implementation...

  20. An energy-saving set-point optimizer with a sliding mode controller for automotive air-conditioning/refrigeration systems

    International Nuclear Information System (INIS)

    Huang, Yanjun; Khajepour, Amir; Ding, Haitao; Bagheri, Farshid; Bahrami, Majid

    2017-01-01

    Highlights: • A novel two-layer energy-saving controller for automotive A/C-R system is developed. • A set-point optimizer at the outer loop is designed based on the steady state model. • A sliding mode controller in the inner loop is built. • Extensively experiments studies show that about 9% energy can be saving by this controller. - Abstract: This paper presents an energy-saving controller for automotive air-conditioning/refrigeration (A/C-R) systems. With their extensive application in homes, industry, and vehicles, A/C-R systems are consuming considerable amounts of energy. The proposed controller consists of two different time-scale layers. The outer or the slow time-scale layer called a set-point optimizer is used to find the set points related to energy efficiency by using the steady state model; whereas, the inner or the fast time-scale layer is used to track the obtained set points. In the inner loop, thanks to its robustness, a sliding mode controller (SMC) is utilized to track the set point of the cargo temperature. The currently used on/off controller is presented and employed as a basis for comparison to the proposed controller. More importantly, the real experimental results under several disturbed scenarios are analysed to demonstrate how the proposed controller can improve performance while reducing the energy consumption by 9% comparing with the on/off controller. The controller is suitable for any type of A/C-R system even though it is applied to an automotive A/C-R system in this paper.

  1. AN IN-DEPTH VIEW OF THE MID-INFRARED PROPERTIES OF POINT SOURCES AND THE DIFFUSE ISM IN THE SMC GIANT H II REGION, N66

    International Nuclear Information System (INIS)

    Whelan, David G.; Johnson, Kelsey E.; Indebetouw, Rémy; Lebouteiller, Vianney; Galliano, Frédéric; Peeters, Els; Bernard-Salas, Jeronimo; Brandl, Bernhard R.

    2013-01-01

    The focus of this work is to study mid-infrared point sources and the diffuse interstellar medium (ISM) in the low-metallicity (∼0.2 Z ☉ ) giant H II region N66 in order to determine properties that may shed light on star formation in these conditions. Using the Spitzer Space Telescope's Infrared Spectrograph, we study polycyclic aromatic hydrocarbon (PAH), dust continuum, silicate, and ionic line emission from 14 targeted infrared point sources as well as spectra of the diffuse ISM that is representative of both the photodissociation regions (PDRs) and the H II regions. Among the point source spectra, we spectroscopically confirm that the brightest mid-infrared point source is a massive embedded young stellar object, we detect silicates in emission associated with two young stellar clusters, and we see spectral features of a known B[e] star that are commonly associated with Herbig Be stars. In the diffuse ISM, we provide additional evidence that the very small grain population is being photodestroyed in the hard radiation field. The 11.3 μm PAH complex emission exhibits an unexplained centroid shift in both the point source and ISM spectra that should be investigated at higher signal-to-noise and resolution. Unlike studies of other regions, the 6.2 μm and 7.7 μm band fluxes are decoupled; the data points cover a large range of I 7.7 /I 11.3 PAH ratio values within a narrow band of I 6.2 /I 11.3 ratio values. Furthermore, there is a spread in PAH ionization, being more neutral in the dense PDR where the radiation field is relatively soft, but ionized in the diffuse ISM/PDR. By contrast, the PAH size distribution appears to be independent of local ionization state. Important to unresolved studies of extragalactic low-metallicity star-forming regions, we find that emission from the infrared-bright point sources accounts for only 20%-35% of the PAH emission from the entire region. These results make a comparative data set to other star-forming regions with

  2. 41 CFR 101-26.606 - Supply support available from the inventory control points of the military departments.

    Science.gov (United States)

    2010-07-01

    ... from the inventory control points of the military departments. 101-26.606 Section 101-26.606 Public... § 101-26.606 Supply support available from the inventory control points of the military departments. Federal civil agencies may obtain items of supply which are procured and managed by the inventory control...

  3. Maximum Power Point Tracking Based on Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Nimrod Vázquez

    2015-01-01

    Full Text Available Solar panels, which have become a good choice, are used to generate and supply electricity in commercial and residential applications. This generated power starts with the solar cells, which have a complex relationship between solar irradiation, temperature, and output power. For this reason a tracking of the maximum power point is required. Traditionally, this has been made by considering just current and voltage conditions at the photovoltaic panel; however, temperature also influences the process. In this paper the voltage, current, and temperature in the PV system are considered to be a part of a sliding surface for the proposed maximum power point tracking; this means a sliding mode controller is applied. Obtained results gave a good dynamic response, as a difference from traditional schemes, which are only based on computational algorithms. A traditional algorithm based on MPPT was added in order to assure a low steady state error.

  4. The Central Point Source in G76.9++1.0 V. R. Marthi1,∗ , J. N. ...

    Indian Academy of Sciences (India)

    Astr. (2011) 32, 451–455 c Indian Academy of Sciences. The Central Point Source in G76.9++1.0. V. R. Marthi1,∗. , J. N. Chengalur1, Y. Gupta1 ... emission has indeed been seen at 2 GHz with the Green Bank Telescope. (GBT), establishing the fact that scattering is responsible for its non- detection at low radio frequencies.

  5. Operational experience of SST1 NBI control system with prototype Ion source

    International Nuclear Information System (INIS)

    Patel, V B; Patel, P J; Singh, N P; Tripathi, V; Thakkar, D; Gupta, L N; Prahlad, V; Sharma, S K; Bandyopadyay, M; Chakraborty, A K; Baruah, U K; Mattoo, S K; Patel, G B; Onali, Raja

    2010-01-01

    This paper presents operational experience of integrated control of the arc-filament and High-voltage power supply of Steady State Tokamak (SST)-1 NBI system using Versa Module Europa (VME) system on prototype Ion source. The control algorithm is implemented on the VxWorks operating system using 'C' language. This paper also describes the operating sequence and controls on power supply system. Discharge and Filament power supplies are controlled in such a way so that necessary discharge current can be available in Ion Source. The discharge current is controlled by manipulating the filament current. Close loop control is implemented on each filament power supply with feedback from Discharge Current to control the overall discharge inside the ion source. Necessary actions for shut OFF and subsequent Turn ON are also taken during breakdowns between the Grids of the ion source. Total numbers of breakdowns are also monitored. Shot is terminated, if the breakdown count is higher than the set value. This control system can be programmed to restart High-voltage power supply within 5mS after breakdown occurs. This control system is capable to handle the all types of dynamics in the system. This paper also presents results of experiment.

  6. Infrastructure of Taiwan photon source control network

    International Nuclear Information System (INIS)

    Chang, Y.T.; Kuo, C.H.; Cheng, Y.S.; Jenny Chen; Hsu, S.Y.; Wu, C.Y.; Hu, K.H.; Hsu, K.T.

    2012-01-01

    A reliable, flexible and secure network is essential for the Taiwan Photon Source (TPS) control system which is based upon the EPICS tool-kit framework. Subsystem sub-nets will connect to control system via EPICS based CA gateways for forwarding data and reducing network traffic. Combining cyber security technologies such as fire-wall, NAT and VLAN, control network is isolated to protect IOCs and accelerator components. Network management tools are used to improve network performance. Remote access mechanism will be constructed for maintenance and troubleshooting. The Ethernet is also used as field-bus for instruments such as power supplies. This paper will describe the system architecture for the TPS control network. Cabling topology, redundancy and maintainability are also discussed. (authors)

  7. The simulation research of dissolved nitrogen and phosphorus non-point source pollution in Xiao-Jiang watershed of Three Gorges Reservoir area.

    Science.gov (United States)

    Wu, Lei; Long, Tian-Yu; Li, Chong-Ming

    2010-01-01

    Xiao-jiang, with a basin area of almost 5,276 km(2) and a length of 182.4 km, is located in the center of the Three Gorges Reservoir Area, and is the largest tributary of the central section in Three Gorges Reservoir Area, farmland accounts for a large proportion of Xiao-jiang watershed, and the hilly cropland of purple soil is much of the farmland of the watershed. After the second phase of water storage in the Three Gorges Reservoir, the majority of sub-rivers in the reservoir area experienced eutrophication phenomenon frequently, and non-point source (NPS) pollution has become an important source of pollution in Xiao-jiang Watershed. Because dissolved nitrogen and phosphorus non-point source pollution are related to surface runoff and interflow, using climatic, topographic and land cover data from the internet and research institutes, the Semi-Distributed Land-use Runoff Process (SLURP) hydrological model was introduced to simulate the complete hydrological cycle of the Xiao-jiang Watershed. Based on the SLURP distributed hydrological model, non-point source pollution annual output load models of land use and rural residents were respectively established. Therefore, using GIS technology, considering the losses of dissolved nitrogen and phosphorus in the course of transport, a dissolved non-point source pollution load dynamic model was established by the organic coupling of the SLURP hydrological model and land-use output model. Through the above dynamic model, the annual dissolved non-point source nitrogen and phosphorus pollution output as well as the load in different types were simulated and quantitatively estimated from 2001 to 2008, furthermore, the loads of Xiao-jiang Watershed were calculated and expressed by temporal and spatial distribution in the Three Gorges Reservoir Area. The simulation results show that: the temporal changes of dissolved nitrogen and phosphorus load in the watershed are close to the inter-annual changes of rainfall runoff, and the

  8. Improvement of lithium chloride dew-point hygrometer for direct reading and controlling of relative humidity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.Z.; Chu, Y.

    1986-01-01

    The lithium chloride dew-point hygrometer has many advantages over other types of hygrometers. However, it only reads and controls the dew-point temperature of air instead of the relative humidity, which is more important in industry, agriculture, food storage, and hygiene. This paper describes a new hygrometer which is based on the same principle as the lithium chloride dew-point hygrometer, but it can read and control the relative humidity directly. The instrument is quick in response and the ranges of temperature and relative humidity are quite large. Its accuracy is normally within 3% RH and its precision is within 2% RH.

  9. Characteristics of infrared point sources associated with OH masers

    International Nuclear Information System (INIS)

    Mu Jimang; Esimbek, Jarken; Zhou Jianjun; Zhang Haijuan

    2010-01-01

    We collect 3249 OH maser sources from the literature published up to April 2007, and compile a new catalog of OH masers. We look for the exciting sources of these masers and their infrared properties from IRAS and MSX data, and make a statistical study. MSX sources associated with stellar 1612 MHz OH masers are located mainly above the blackbody line; this is caused by the dust absorption of stellar envelopes, especially in the MSX A band. The mid-IR sources associated with stellar OH masers are concentrated in a small region in an [A]-[D] vs. [A]-[E] diagram with a small fraction of contamination; this gives us a new criterion to search for new stellar OH masers and distinguish stellar masers from unknown types of OH masers. IR sources associated with 1612 MHz stellar OH masers show an expected result: the average flux of sources with F60 > F25 increases with increasing wavelength, while those with F60 F25.

  10. Visco-elastic controlled-source full waveform inversion without surface waves

    Science.gov (United States)

    Paschke, Marco; Krause, Martin; Bleibinhaus, Florian

    2016-04-01

    We developed a frequency-domain visco-elastic full waveform inversion for onshore seismic experiments with topography. The forward modeling is based on a finite-difference time-domain algorithm by Robertsson that uses the image-method to ensure a stress-free condition at the surface. The time-domain data is Fourier-transformed at every point in the model space during the forward modeling for a given set of frequencies. The motivation for this approach is the reduced amount of memory when computing kernels, and the straightforward implementation of the multiscale approach. For the inversion, we calculate the Frechet derivative matrix explicitly, and we implement a Levenberg-Marquardt scheme that allows for computing the resolution matrix. To reduce the size of the Frechet derivative matrix, and to stabilize the inversion, an adapted inverse mesh is used. The node spacing is controlled by the velocity distribution and the chosen frequencies. To focus the inversion on body waves (P, P-coda, and S) we mute the surface waves from the data. Consistent spatiotemporal weighting factors are applied to the wavefields during the Fourier transform to obtain the corresponding kernels. We test our code with a synthetic study using the Marmousi model with arbitrary topography. This study also demonstrates the importance of topography and muting surface waves in controlled-source full waveform inversion.

  11. A quality control program for radiation sources

    International Nuclear Information System (INIS)

    Almeida, C.E. de; Sibata, C.H.; Cecatti, E.R.; Kawakami, N.S.; Alexandre, A.C.; Chiavegatti Junior, M.

    1982-01-01

    An extensive quality control program was established covering the following areas: physical parameters of the therapeutical machines, dosimetric standards, preventive maintenance of radiation sources and measuring instruments. A critical evaluation of this program was done after two years (1977-1979) of routine application and the results will be presented. The fluctuation on physical parameters strongly supports the efforts and cost of a quality control program. This program has certainly improved the accuracy required on the delivery of the prescribed dose for radiotherapy treatment. (Author) [pt

  12. Sliding-Mode Controller for Maximum Power Point Tracking in Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Paula Andrea Ortiz Valencia

    2015-11-01

    Full Text Available The maximum power point tracking (MPPT of photovoltaic systems must be as fast and accurate as possible to increase the power production, which eventually increases the PV system profitability. This paper proposes and mathematically analyses a sliding-mode controller to provide a fast and accurate maximum power point tracking in grid-connected photovoltaic systems using a single control stage. This approach avoids the circular dependency in the design of classical cascade controllers used to optimize the photovoltaic system operation, and at the same time, it reduces the number of controllers and avoids the use of linearized models to provide global stability in all the operation range. Such a compact solution also reduces the system cost and implementation complexity. To ensure the stability of the proposed solution, detailed mathematical analyses are performed to demonstrate the fulfillment of the transversality, reachability and equivalent control conditions. Finally, the performance of the proposed solution is validated using detailed simulations, executed in the power electronics simulator PSIM, accounting for both environmental and load perturbations.

  13. Euromet action 428: transfer of ge detectors efficiency calibration from point source geometry to other geometries; Action euromet 428: transfert de l'etalonnage en rendement de detecteurs au germanium pour une source ponctuelle vers d'autres geometries

    Energy Technology Data Exchange (ETDEWEB)

    Lepy, M.Ch

    2000-07-01

    The EUROMET project 428 examines efficiency transfer computation for Ge gamma-ray spectrometers when the efficiency is known for a reference point source geometry in the 60 keV to 2 MeV energy range. For this, different methods are used, such as Monte Carlo simulation or semi-empirical computation. The exercise compares the application of these methods to the same selected experimental cases to determine the usage limitations versus the requested accuracy. For carefully examining these results and trying to derive information for improving the computation codes, this study was limited to a few simple cases, from an experimental efficiency calibration for point source at 10-cm source-to-detector distance. The first part concerns the simplest case of geometry transfer, i.e., using point sources for 3 source-to-detector distances: 2,5 and 20 cm; the second part deals with transfer from point source geometry to cylindrical geometry with three different matrices. The general results show that the deviations between the computed results and the measured efficiencies are for the most part within 10%. The quality of the results is rather inhomogeneous and shows that these codes cannot be used directly for metrological purposes. However, most of them are operational for routine measurements when efficiency uncertainties of 5-10% can be sufficient. (author)

  14. Regulatory inspection: a powerful tool to control industrial radioactive sources

    International Nuclear Information System (INIS)

    Silva, F.C.A. da; Leocadio, J.C.; Ramalho, A.T.

    2008-01-01

    An important contribution for Brazilian development, especially for the quality control of products, is the use of radiation sources by conventional industries. There are in Brazil roughly 3,000 radioactive sources spread out among 950 industries. The main industrial practices involved are: industrial radiography, industrial irradiators, industrial accelerators, well logging petroleum and nuclear gauges. More than 1,800 Radiation Protection Officers (RPOs) were qualified to work in these practices. The present work presents a brief description of the safety control over industrial radioactive installations performed by the Brazilian Regulatory Authority, i.e. the National Commission of Nuclear Energy (CNEN). This paper also describes the national system for radiation safety inspections, the regulation infrastructure and the national inventory of industrial installations. The inspections are based on specific indicators, and their periodicity depends on the risk and type of installation. The present work discusses some relevant aspects that must be considered during the inspections, in order to make the inspections more efficient in controlling the sources. One of these aspects regards the evaluation of the storage place for the sources, a very important parameter for preventing future risky situations. (author)

  15. APPLICATION OF CONTROLLED SOURCE AUDIO MAGNETOTELLURIC (CSAMT AT GEOTHERMAL

    Directory of Open Access Journals (Sweden)

    Susilawati S.

    2017-04-01

    Full Text Available CSAMT or Controlled Source Audio-Magnetotelluric is one of the Geophysics methods to determine the resistivity of rock under earth surface. CSAMT method utilizes artificial stream and injected into the ground, the frequency of artificial sources ranging from 0.1 Hz to 10 kHz, CSAMT data source effect correction is inverted. From the inversion results showed that there is a layer having resistivity values ranged between 2.5 Ω.m – 15 Ω.m, which is interpreted that the layer is clay.

  16. Identification of gram-negative bacteria from critical control points of raw and pasteurized cow milk consumed at Gondar town and its suburbs, Ethiopia.

    Science.gov (United States)

    Garedew, Legesse; Berhanu, Ayalew; Mengesha, Desalegne; Tsegay, Getachew

    2012-11-06

    Milk is highly prone to contamination and can serve as an efficient vehicle for human transmission of foodborne pathogens, especially gram-negative bacteria, as these are widely distributed in the environment. This cross-sectional study of gram-negative staining bacterial contamination of milk meant for human consumption was carried out from October 2010 to May 2011 in Gondar town, Ethiopia. Milk samples were collected from critical control points, from production to consumption, that were hypothesized to be a source of potential contamination. Milk sampling points included smallholder's milk producers, dairy co-operatives, a milk processing plant, and supermarkets. The hygienic procedures applied during milking, milk collection, transportation, pasteurization, and postpasteurization storage conditions at these specified critical control points were evaluated. Standard bacteriological cultivation and biochemical assays were used to isolate and identify bacterial pathogens in the milk samples. The results of the current study showed that conditions for contamination of raw milk at different critical points were due to less hygienic practices in pre-milking udder preparation, sub-optimal hygiene of milk handlers, and poor sanitation practices associated with milking and storage equipments. Among all critical control points considered, transportation containers at milk collection centers and at processing plants were found to be the most heavily contaminated with gram-negative staining bacterial species. Overall, 54 different bacterial species were indentified, and Escherichia coli (29.6%), Pseudomonas aeruginosa (18.5%), and Klebsiella pneumoniae (16.7%), were the most commonly identified gram-negative staining bacterial pathogens. Of particular interest was that no gram-negative staining bacteria were isolated from pasteurized milk samples with varying shelf life. This study showed the presence of diverse pathogenic gram-negative staining bacterial species in raw

  17. Identification of gram-negative bacteria from critical control points of raw and pasteurized cow milk consumed at Gondar town and its suburbs, Ethiopia

    Directory of Open Access Journals (Sweden)

    Garedew Legesse

    2012-11-01

    Full Text Available Abstract Background Milk is highly prone to contamination and can serve as an efficient vehicle for human transmission of foodborne pathogens, especially gram-negative bacteria, as these are widely distributed in the environment. Methods This cross-sectional study of gram-negative staining bacterial contamination of milk meant for human consumption was carried out from October 2010 to May 2011 in Gondar town, Ethiopia. Milk samples were collected from critical control points, from production to consumption, that were hypothesized to be a source of potential contamination. Milk sampling points included smallholder’s milk producers, dairy co-operatives, a milk processing plant, and supermarkets. The hygienic procedures applied during milking, milk collection, transportation, pasteurization, and postpasteurization storage conditions at these specified critical control points were evaluated. Standard bacteriological cultivation and biochemical assays were used to isolate and identify bacterial pathogens in the milk samples. Results The results of the current study showed that conditions for contamination of raw milk at different critical points were due to less hygienic practices in pre-milking udder preparation, sub-optimal hygiene of milk handlers, and poor sanitation practices associated with milking and storage equipments. Among all critical control points considered, transportation containers at milk collection centers and at processing plants were found to be the most heavily contaminated with gram-negative staining bacterial species. Overall, 54 different bacterial species were indentified, and Escherichia coli (29.6%, Pseudomonas aeruginosa (18.5%, and Klebsiella pneumoniae (16.7%, were the most commonly identified gram-negative staining bacterial pathogens. Of particular interest was that no gram-negative staining bacteria were isolated from pasteurized milk samples with varying shelf life. Conclusion This study showed the presence of

  18. Source-dependent and source-independent controls on plutonium oxidation state and colloid associations in groundwater.

    Science.gov (United States)

    Buesseler, Ken O; Kaplan, Daniel I; Dai, Minhan; Pike, Steven

    2009-03-01

    Plutonium (Pu) was characterized for its isotopic composition, oxidation states, and association with colloids in groundwater samples near disposal basins in F-Area of the Savannah River Site and compared to similar samples collected six years earlier. Two sources of Pu were identified, the disposal basins, which contained a 24Pu/l39Pu isotopic signature consistent with weapons grade Pu, and 244Cm, a cocontaminant that is a progenitor radionuclide of 24Pu. 24Pu that originated primarily from 244Cm tended to be appreciably more oxidized (Pu(V/VI)), less associated with colloids (approximately 1 kDa - 0.2 microm), and more mobile than 239Pu, as suggested by our prior studies at this site. This is not evidence of isotope fractionation but rather "source-dependent" controls on 240Pu speciation which are processes that are not at equilibrium, i.e., processes that appear kinetically hindered. There were also "source-independent" controls on 239Pu speciation, which are those processes that follow thermodynamic equilibrium with their surroundings. For example, a groundwater pH increase in one well from 4.1 in 1998 to 6.1 in 2004 resulted in an order of magnitude decrease in groundwater 239Pu concentrations. Similarly, the fraction of 239Pu in the reduced Pu(III/IV) and colloidal forms increased systematically with decreases in redox condition in 2004 vs 1998. This research demonstrates the importance of source-dependent and source-independent controls on Pu speciation which would impact Pu mobility during changes in hydrological, chemical, or biological conditions on both seasonal and decadal time scales, and over short spatial scales. This implies more dynamic shifts in Pu speciation, colloids association, and transport in groundwater than commonly believed.

  19. Effects of the airwave in time-domain marine controlled-source electromagnetics

    NARCIS (Netherlands)

    Hunziker, J.W.; Slob, E.C.; Mulder, W.

    2011-01-01

    In marine time-domain controlled-source electromagnetics (CSEM), there are two different acquisition methods: with horizontal sources for fast and simple data acquisition or with vertical sources for minimizing the effects of the airwave. Illustrations of the electric field as a function of space

  20. Eternal triangle: the interaction of light source, electrical control gear, and optics

    Science.gov (United States)

    S'heeren, Griet

    1998-04-01

    In this particular 'affair' the participants are less than human but have individual personalities they bring to their relationship with each other. High pressure metal halide lamps such as BriteArc lamps have the highest luminance and radiance of all continuously operating practical light source. Since these lamps have short arcs and are available in power ratings from about 30W to 30kW they have found applications with various optical systems. Besides the lamps, such systems include an electrical control device and an optical system. To fulfil the user's requirements for a specific application, it is not only important to choose the right lamp, but crucial to achieve a harmonious marriage between the light source, electrical control device and the optics. To run a high pressure discharge lamp an ignitor/ballast system is essential This stabilizes the lamp parameters. The chemical components inside the lamp determine the lamp voltage and the gear determines, via the current, the lamp power. These are directly related in the luminance and color temperature of the emitted light. Therefore lamp performance and effective life are dependent on the ignitor, control gear and lamp combination. Since the lamp emits radiation in all directions, collection of the light from a lamp can be improved by using reflectors to deliver the light into a lens system. Since lamps with short arc gaps approach a point source they appear ideal for optical system applications. The shape of the reflector and the focusing of the lamp determine which part of the light is collected out of the light-arc. In the case of an LCD projector, the final light output also depends on the transmission characteristics of the LCD panels. Their nonlinearity causes the color of the emitted light to be different from the lamp color. All these parameters have to be optimized to obtain the highest performance. This leads to the conclusion that a carefully matched combination of lamp, ignitor/ballast and optics

  1. Impedance-Source Networks for Electric Power Conversion Part II

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Peng, Fang Zheng; Blaabjerg, Frede

    2015-01-01

    Impedance-source networks cover the entire spectrum of electric power conversion applications (dc-dc, dc-ac, ac-dc, ac-ac) controlled and modulated by different modulation strategies to generate the desired dc or ac voltage and current at the output. A comprehensive review of various impedance......-source-network-based power converters has been covered in a previous paper and main topologies were discussed from an application point of view. Now Part II provides a comprehensive review of the most popular control and modulation strategies for impedance-source network-based power converters/inverters. These methods...

  2. Large Industrial Point Sources in Italy: a focus on mercury concentrations resulting from three seasonal ship-borne measurements

    Directory of Open Access Journals (Sweden)

    Bencardino M.

    2013-04-01

    Full Text Available In Italy there are 25 Large Industrial Point Sources whose mercury emissions in air exceed the established threshold of 10 kg year−1. Many of these mercury point sources, mostly distributed along the Italian coastal area, are located at sites qualified as National Interest Rehabilitation Sites because of documented contamination in qualitative and/or quantitative terms and of potential health impact. Atmospheric mercury emissions related to Italian Large Industrial Point Sources, with a value of 1.04 Mg·yr−1 for 2007, have a not negligible contribution, accounting, on their own, for more than 10% of the total mercury emissions resulting from all activity sectors at a national level. Among others, thermal power stations, pig iron and steel as well as basic inorganic chemical production, result to be the main contributing industrial activities. In order to assess how mercury species concentrations and distribution in the Marine Boundary Layer (MBL change with vicinity to large industrial sites, measurements of atmospheric mercury were performed during three oceanographic campaigns aboard the Research Vessel (R.V. Urania of the Italian CNR. Collection of GEM, GOM and PBM was conducted across the Adriatic sea, during autumn 2004 (27th of October to 12th of November and summer 2005 (17th to 29th of June, and across the Tyrrhenian sea during autumn 2007 (12th of September to 1st October. Analysis were carried out with reference to the period in which the R.V. Urania has stopped close to the main Italian industrial contaminated sites. Explorative statistical parameters of atmospheric mercury species were computed over each single stop-period and then compared with the overall cruise campaign measurements. Results are herein presented and discussed.

  3. The XMM-SERVS survey: new XMM-Newton point-source catalog for the XMM-LSS field

    Science.gov (United States)

    Chen, C.-T. J.; Brandt, W. N.; Luo, B.; Ranalli, P.; Yang, G.; Alexander, D. M.; Bauer, F. E.; Kelson, D. D.; Lacy, M.; Nyland, K.; Tozzi, P.; Vito, F.; Cirasuolo, M.; Gilli, R.; Jarvis, M. J.; Lehmer, B. D.; Paolillo, M.; Schneider, D. P.; Shemmer, O.; Smail, I.; Sun, M.; Tanaka, M.; Vaccari, M.; Vignali, C.; Xue, Y. Q.; Banerji, M.; Chow, K. E.; Häußler, B.; Norris, R. P.; Silverman, J. D.; Trump, J. R.

    2018-04-01

    We present an X-ray point-source catalog from the XMM-Large Scale Structure survey region (XMM-LSS), one of the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS) fields. We target the XMM-LSS region with 1.3 Ms of new XMM-Newton AO-15 observations, transforming the archival X-ray coverage in this region into a 5.3 deg2 contiguous field with uniform X-ray coverage totaling 2.7 Ms of flare-filtered exposure, with a 46 ks median PN exposure time. We provide an X-ray catalog of 5242 sources detected in the soft (0.5-2 keV), hard (2-10 keV), and/or full (0.5-10 keV) bands with a 1% expected spurious fraction determined from simulations. A total of 2381 new X-ray sources are detected compared to previous source catalogs in the same area. Our survey has flux limits of 1.7 × 10-15, 1.3 × 10-14, and 6.5 × 10-15 erg cm-2 s-1 over 90% of its area in the soft, hard, and full bands, respectively, which is comparable to those of the XMM-COSMOS survey. We identify multiwavelength counterpart candidates for 99.9% of the X-ray sources, of which 93% are considered as reliable based on their matching likelihood ratios. The reliabilities of these high-likelihood-ratio counterparts are further confirmed to be ≈97% reliable based on deep Chandra coverage over ≈5% of the XMM-LSS region. Results of multiwavelength identifications are also included in the source catalog, along with basic optical-to-infrared photometry and spectroscopic redshifts from publicly available surveys. We compute photometric redshifts for X-ray sources in 4.5 deg2 of our field where forced-aperture multi-band photometry is available; >70% of the X-ray sources in this subfield have either spectroscopic or high-quality photometric redshifts.

  4. Correction of head movements in positron emission tomography using point source tracking system: a simulation study.

    Science.gov (United States)

    Nazarparvar, Babak; Shamsaei, Mojtaba; Rajabi, Hossein

    2012-01-01

    The motion of the head during brain positron emission tomography (PET) acquisitions has been identified as a source of artifact in the reconstructed image. In this study, a method is described to develop an image-based motion correction technique for correcting the post-acquisition data without using external optical motion-tracking system such as POLARIS. In this technique, GATE has been used to simulate PET brain scan using point sources mounted around the head to accurately monitor the position of the head during the time frames. The measurement of head motion in each frame showed a transformation in the image frame matrix, resulting in a fully corrected data set. Using different kinds of phantoms and motions, the accuracy of the correction method is tested and its applicability to experimental studies is demonstrated as well.

  5. Maximum Power Point Tracking of Photovoltaic System for Traffic Light Application

    OpenAIRE

    Muhida, Riza; Mohamad, Nor Hilmi; Legowo, Ari; Irawan, Rudi; Astuti, Winda

    2013-01-01

    Photovoltaic traffic light system is a significant application of renewable energy source. The development of the system is an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. Since photovoltaic (PV) modules still have relatively low conversion efficiency, an alternative control of maximum power point tracking (MPPT) method is applied to the traffic light system. MPPT is intended to catch up th...

  6. Experimental properties of gluon and quark jets from a point source

    CERN Document Server

    Abbiendi, G.; Alexander, G.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Blobel, V.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Davis, R.; De Jong, S.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Fiedler, F.; Fierro, M.; Fleck, I.; Folman, R.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon, J.; Gascon-Shotkin, S.M.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hoch, M.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanzaki, J.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lauber, J.; Lautenschlager, S.R.; Lawson, I.; Layter, J.G.; Lee, A.M.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Lui, D.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Markopoulos, C.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menke, S.; Merritt, F.S.; Mes, H.; Meyer, J.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mir, R.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Oreglia, M.J.; Orito, S.; Palinkas, J.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Poli, B.; Polok, J.; Przybycien, M.; Rembser, C.; Rick, H.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Sittler, A.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Steuerer, J.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turcot, A.S.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Yekutieli, G.; Zacek, V.; Zer-Zion, D.

    1999-01-01

    Gluon jets are identified in hadronic Z0 decays as all the particles in a hemisphere opposite to a hemisphere containing two tagged quark jets. Gluon jets defined in this manner are equivalent to gluon jets produced from a color singlet point source and thus correspond to the definition employed for most theoretical calculations. In a separate stage of the analysis, we select quark jets in a manner to correspond to calculations, as the particles in hemispheres of flavor tagged light quark (uds) events. We present the distributions of rapidity, scaled energy, the logarithm of the momentum, and transverse momentum with respect to the jet axes, for charged particles in these gluon and quark jets. We also examine the charged particle multiplicity distributions of the jets in restricted intervals of rapidity. For soft particles at large transverse momentum, we observe the charged particle multiplicity ratio of gluon to quark jets to be 2.29 +- 0.09 +- 0.15 in agreement with the prediction that this ratio should ap...

  7. 40 CFR 413.74 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS ELECTROPLATING POINT SOURCE CATEGORY Electroless Plating Subcategory... regulation must implement the toxic organic management plan approved by the control authority. (Secs. 301, 304, 306, 307, 308, and 501 of the Clean Water Act (the Federal Water Pollution Control Act Amendments...

  8. Application of hazard analysis critical control points (HACCP) to organic chemical contaminants in food.

    Science.gov (United States)

    Ropkins, K; Beck, A J

    2002-03-01

    Hazard Analysis Critical Control Points (HACCP) is a systematic approach to the identification, assessment, and control of hazards that was developed as an effective alternative to conventional end-point analysis to control food safety. It has been described as the most effective means of controlling foodborne diseases, and its application to the control of microbiological hazards has been accepted internationally. By contrast, relatively little has been reported relating to the potential use of HACCP, or HACCP-like procedures, to control chemical contaminants of food. This article presents an overview of the implementation of HACCP and discusses its application to the control of organic chemical contaminants in the food chain. Although this is likely to result in many of the advantages previously identified for microbiological HACCP, that is, more effective, efficient, and economical hazard management, a number of areas are identified that require further research and development. These include: (1) a need to refine the methods of chemical contaminant identification and risk assessment employed, (2) develop more cost-effective monitoring and control methods for routine chemical contaminant surveillance of food, and (3) improve the effectiveness of process optimization for the control of chemical contaminants in food.

  9. Plasma control for efficient extreme ultra-violet source

    International Nuclear Information System (INIS)

    Takahashi, Kensaku; Nakajima, Mitsuo; Kawamura, Tohru; Shiho, Makoto; Hotta, Eiki; Horioka, Kazuhiko

    2008-01-01

    To generate a high efficiency extreme-ultraviolet (EUV) source, effects of plasma shape for controlling radiative plasmas based on xenon capillary discharge are experimentally investigated. The radiation characteristics observed via tapered capillary discharge are compared with those of straight one. From the comparison, the long emission period and different plasma behaviors of tapered capillary discharge are confirmed. This means that control of the plasma geometry is effective for prolonging the EUV emission period. This result also indicates that the plasma shape control seems to have a potential for enhancing the conversion efficiency. (author)

  10. Regulatory control of radiation sources in the Philippines

    International Nuclear Information System (INIS)

    Daroy, Rosita R.

    1995-01-01

    This paper is concerned with the radiation protection and safety infrastructure providing emphasis on the regulation and control of radiation sources in the Philippines. It deals with the experiences of the Philippine Nuclear Research Institute, as a regulatory body, in the regulation and control of radioactive materials in radiotherapy, nuclear medicine, industrial radiography, industrial gauges, industrial irradiators, and well logging. This paper includes an inventory of the sources and types of devices/equipment used by licensed users of radioactive materials in the Philippines as a contribution to the data base being prepared by the IAEA. The problems encountered by the regulatory body in the licensing and enforcement process, as well as the lessons learned from incidents involving radioactive materials are discussed. Plans for improving compliance to the regulations and enhancing the effectiveness of PNRI's regulatory functions are presented. (author)

  11. Magnetic-field control of quantum critical points of valence transition.

    Science.gov (United States)

    Watanabe, Shinji; Tsuruta, Atsushi; Miyake, Kazumasa; Flouquet, Jacques

    2008-06-13

    We study the mechanism of how critical end points of first-order valence transitions are controlled by a magnetic field. We show that the critical temperature is suppressed to be a quantum critical point (QCP) by a magnetic field, and unexpectedly, the QCP exhibits nonmonotonic field dependence in the ground-state phase diagram, giving rise to the emergence of metamagnetism even in the intermediate valence-crossover regime. The driving force of the field-induced QCP is clarified to be cooperative phenomena of the Zeeman and Kondo effects, which create a distinct energy scale from the Kondo temperature. This mechanism explains the peculiar magnetic response in CeIrIn(5) and the metamagnetic transition in YbXCu(4) for X=In as well as the sharp contrast between X=Ag and Cd.

  12. Nonlinear Burn Control and Operating Point Optimization in ITER

    Science.gov (United States)

    Boyer, Mark; Schuster, Eugenio

    2013-10-01

    Control of the fusion power through regulation of the plasma density and temperature will be essential for achieving and maintaining desired operating points in fusion reactors and burning plasma experiments like ITER. In this work, a volume averaged model for the evolution of the density of energy, deuterium and tritium fuel ions, alpha-particles, and impurity ions is used to synthesize a multi-input multi-output nonlinear feedback controller for stabilizing and modulating the burn condition. Adaptive control techniques are used to account for uncertainty in model parameters, including particle confinement times and recycling rates. The control approach makes use of the different possible methods for altering the fusion power, including adjusting the temperature through auxiliary heating, modulating the density and isotopic mix through fueling, and altering the impurity density through impurity injection. Furthermore, a model-based optimization scheme is proposed to drive the system as close as possible to desired fusion power and temperature references. Constraints are considered in the optimization scheme to ensure that, for example, density and beta limits are avoided, and that optimal operation is achieved even when actuators reach saturation. Supported by the NSF CAREER award program (ECCS-0645086).

  13. In vivo quantitative imaging of point-like bioluminescent and fluorescent sources: Validation studies in phantoms and small animals post mortem

    Science.gov (United States)

    Comsa, Daria Craita

    2008-10-01

    There is a real need for improved small animal imaging techniques to enhance the development of therapies in which animal models of disease are used. Optical methods for imaging have been extensively studied in recent years, due to their high sensitivity and specificity. Methods like bioluminescence and fluorescence tomography report promising results for 3D reconstructions of source distributions in vivo. However, no standard methodology exists for optical tomography, and various groups are pursuing different approaches. In a number of studies on small animals, the bioluminescent or fluorescent sources can be reasonably approximated as point or line sources. Examples include images of bone metastases confined to the bone marrow. Starting with this premise, we propose a simpler, faster, and inexpensive technique to quantify optical images of point-like sources. The technique avoids the computational burden of a tomographic method by using planar images and a mathematical model based on diffusion theory. The model employs in situ optical properties estimated from video reflectometry measurements. Modeled and measured images are compared iteratively using a Levenberg-Marquardt algorithm to improve estimates of the depth and strength of the bioluminescent or fluorescent inclusion. The performance of the technique to quantify bioluminescence images was first evaluated on Monte Carlo simulated data. Simulated data also facilitated a methodical investigation of the effect of errors in tissue optical properties on the retrieved source depth and strength. It was found that, for example, an error of 4 % in the effective attenuation coefficient led to 4 % error in the retrieved depth for source depths of up to 12mm, while the error in the retrieved source strength increased from 5.5 % at 2mm depth, to 18 % at 12mm depth. Experiments conducted on images from homogeneous tissue-simulating phantoms showed that depths up to 10mm could be estimated within 8 %, and the relative

  14. RCT: Module 2.08, Radiological Source Control, Course 8774

    Energy Technology Data Exchange (ETDEWEB)

    Hillmer, Kurt T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-10

    radioactive source is material used for its emitted radiation. Sources are sealed or unsealed and are classified as accountable or exempt. Radioactive sources are used for response checks, functional checks, and the calibration of instruments and monitors to traceable standards. To ensure the safety and welfare of all personnel, it is important to maintain control of radioactive sources to minimize the potential for the spread of contamination, unnecessary exposure to personnel, loss or theft, and improper disposal. This course will prepare the student with the skills necessary for RCT qualification by passing quizzes, tests, and the RCT Comprehensive Phase 1, Unit 2 Examination (TEST 27566) and will provide in-the-field skills.

  15. Control of radiation sources in Brazil

    International Nuclear Information System (INIS)

    Oliveira, Silvia Maria Velasques de; Menezes, Sergio Ferreira; Alves Filho, Aristeu Dacio; Xavier, Ana Maria

    1997-01-01

    The radiological accident occurred in Goiania, in 1987, brought to light several deficiencies in the conduction of the licensing processes of medical, industrial and research facilities that handle radioisotopes as well as int he control of radioactive sources in Brazil. The objective of this article is to describe some of the technical and administrative measures taken to ensure the adoption of appropriate radiological safety standards throughout the country, thus reducing the incidence of radiological accidents. (author)

  16. Cross-correlation of the cosmic microwave background with the 2MASS galaxy survey: Signatures of dark energy, hot gas, and point sources

    International Nuclear Information System (INIS)

    Afshordi, Niayesh; Loh, Yeong-Shang; Strauss, Michael A.

    2004-01-01

    We cross-correlate the cosmic microwave background temperature anisotropies observed by the Wilkinson Microwave Anisotropy Probe (WMAP) with the projected distribution of extended sources in the Two Micron All Sky Survey (2MASS). By modeling the theoretical expectation for this signal, we extract the signatures of dark energy [integrated Sachs-Wolfe effect (ISW)], hot gas [thermal Sunyaev-Zeldovich (SZ) effect], and microwave point sources in the cross-correlation. Our strongest signal is the thermal SZ, at the 3.1-3.7σ level, which is consistent with the theoretical prediction based on observations of x-ray clusters. We also see the ISW signal at the 2.5σ level, which is consistent with the expected value for the concordance ΛCDM cosmology, and is an independent signature of the presence of dark energy in the Universe. Finally, we see the signature of microwave point sources at the 2.7σ level

  17. A new lunar absolute control point: established by images from the landing camera on Chang'e-3

    International Nuclear Information System (INIS)

    Wang Fen-Fei; Liu Jian-Jun; Li Chun-Lai; Ren Xin; Mu Ling-Li; Yan Wei; Wang Wen-Rui; Xiao Jing-Tao; Tan Xu; Zhang Xiao-Xia; Zou Xiao-Duan; Gao Xing-Ye

    2014-01-01

    The establishment of a lunar control network is one of the core tasks in selenodesy, in which defining an absolute control point on the Moon is the most important step. However, up to now, the number of absolute control points has been very sparse. These absolute control points have mainly been lunar laser ranging retroreflectors, whose geographical location can be observed by observations on Earth and also identified in high resolution lunar satellite images. The Chang'e-3 (CE-3) probe successfully landed on the Moon, and its geographical location has been monitored by an observing station on Earth. Since its positional accuracy is expected to reach the meter level, the CE-3 landing site can become a new high precision absolute control point. We use a sequence of images taken from the landing camera, as well as satellite images taken by CE-1 and CE-2, to identify the location of the CE-3 lander. With its geographical location known, the CE-3 landing site can be established as a new absolute control point, which will effectively expand the current area of the lunar absolute control network by 22%, and can greatly facilitate future research in the field of lunar surveying and mapping, as well as selenodesy

  18. Non-point Source Pollution Modeling Using Geographic Information System (GIS for Representing Best Management Practices (BMP in the Gorganrood Watershed

    Directory of Open Access Journals (Sweden)

    Z. Pasandidehfard

    2014-09-01

    Full Text Available The most important pollutants that cause water pollution are nitrogen and phosphorus from agricultural runoff called Non-Point Source Pollution (NPS. To solve this problem, management practices known as BMPs or Best Management Practices are applied. One of the common methods for Non-Point Source Pollution prediction is modeling. By modeling, efficiency of many practices can be tested before application. In this study, land use changes were studied from the years 1984 till 2010 that showed an increase in agricultural lands from 516908.52 to 630737.19 ha and expansion of cities from 5237.87 to 15487.59 ha and roads from 9666.07 to 11430.24 ha. Using L-THIA model (from nonpoint source pollution models for both land use categories, the amount of pollutant and the volume of runoff were calculated that showed high growth. Then, the seventh sub-basin was recognized as a critical zone in terms of pollution among the sub-basins. In the end, land use change was considered as a BMP using Multi-Criteria Evaluation (MCE based on which a more suitable land use map was produced. After producing the new land use map, L-THIA model was run again and the result of the model was compared to the actual land use to show the effect of this BMP. Runoff volume decreased from 367.5 to 308.6 M3/ha and nitrogen in runoff was reduced from 3.26 to 1.58 mg/L and water BOD from 3.61 to 2.13 mg/L. Other pollutants also showed high reduction. In the end, land use change is confirmed as an effective BMP for Non-Point Source Pollution reduction.

  19. [Automatic adjustment control system for DC glow discharge plasma source].

    Science.gov (United States)

    Wan, Zhen-zhen; Wang, Yong-qing; Li, Xiao-jia; Wang, Hai-zhou; Shi, Ning

    2011-03-01

    There are three important parameters in the DC glow discharge process, the discharge current, discharge voltage and argon pressure in discharge source. These parameters influence each other during glow discharge process. This paper presents an automatic control system for DC glow discharge plasma source. This system collects and controls discharge voltage automatically by adjusting discharge source pressure while the discharge current is constant in the glow discharge process. The design concept, circuit principle and control program of this automatic control system are described. The accuracy is improved by this automatic control system with the method of reducing the complex operations and manual control errors. This system enhances the control accuracy of glow discharge voltage, and reduces the time to reach discharge voltage stability. The glow discharge voltage stability test results with automatic control system are provided as well, the accuracy with automatic control system is better than 1% FS which is improved from 4% FS by manual control. Time to reach discharge voltage stability has been shortened to within 30 s by automatic control from more than 90 s by manual control. Standard samples like middle-low alloy steel and tin bronze have been tested by this automatic control system. The concentration analysis precision has been significantly improved. The RSDs of all the test result are better than 3.5%. In middle-low alloy steel standard sample, the RSD range of concentration test result of Ti, Co and Mn elements is reduced from 3.0%-4.3% by manual control to 1.7%-2.4% by automatic control, and that for S and Mo is also reduced from 5.2%-5.9% to 3.3%-3.5%. In tin bronze standard sample, the RSD range of Sn, Zn and Al elements is reduced from 2.6%-4.4% to 1.0%-2.4%, and that for Si, Ni and Fe is reduced from 6.6%-13.9% to 2.6%-3.5%. The test data is also shown in this paper.

  20. Licensing authority's control of radiation sources and nuclear materials in Brazil

    International Nuclear Information System (INIS)

    Binns, D.A.C.

    2002-01-01

    Full text: The Brazilian Nuclear Energy Commission is the national licensing authority and among its responsibilities is the control of nuclear materials and radiation sources. This control is carried out in three different ways: 1) Control of the import and export of nuclear materials and radiation sources. To be able to import or export any nuclear material or radiation source, the user has to have an explicit permission of the licensing authority. This is controlled by electronic means in which the user has to fill a special form found on the licensing authority's home page, where he has to fill in his name, license number, license number of his radiation protection officer and data of the material to be imported or exported. These data are checked with a data base that contains all the information of the licensed users and qualified personnel before authorization is emitted. The airport authorities have already installed x-ray machines to check all baggages entering or leaving the country. 2) Transport and transfer permit for radiation sources. In order to transport and/or transfer radiations sources and nuclear materials within the country, the user(s) have to submit an application to the licensing authority. The user(s) fill out an application form where he fills in his company's name, licensing I.D., radiation protection officer's name and I.D and identification of the sources involved. These information are checked with the licensing operations data before the operations is permitted. 3) Inspections and radiation monitoring systems. Routine and regulatory inspections are continuously carried out where the user's radiation sources and nuclear materials inventory are checked. Also the physical security and protection of these materials are verified. The installation of monitoring systems is an item that is being discussed with the airport authorities so as to increase the possibilities of detecting any illegal transport of these materials. (author)