Spatial characterization of relativistic electron enhancements in the Earth's outer radiation belt during the Van Allen Probes era

Science.gov (United States)

Pinto, V. A.; Bortnik, J.; Moya, P. S.; Lyons, L. R.; Sibeck, D. G.; Kanekal, S. G.

2017-12-01

Using Van Allen Probes Relativistic Electron-Proton Telescope (REPT) instrument we have identified 73 relativistic electron enhancement events in the outer radiation belt that occurred at different L values between L = 2.5 and L = 6.0. To determine an enhancement, we have used three different identification methods. We then determine the radial location, MLT location, timing and strength of those enhancements. We discuss the differences of each of the methods and test them to pinpoint the origin and spatial propagation of each enhancement. We have classified the events based on the radial propagation, speed of enhancement and intensity of fluxes and response for energy channels ranging from 1.8 MeV to 6.3 MeV. In addition, we have used OMNI data to study the statistical properties of the solar wind during each event and have classified similarities and differences that might be relevant for each group of enhancements and help us determine the physical process responsible for different types of enhancements. Additionally, we have used >2 MeV electron fluxes at geostationary orbit as measured by the GOES 13 and 15 Energetic Particle Sensor (EPS) instrument to compare our results with the geostationary orbit. Our results suggest that under certain conditions GOES data can be used to predict fluxes at the core of the radiation belt and vice-versa.

Flow of Energy through the Inner Magnetosphere during the March 17, 2015 solar storm as observed by the Van Allen Probes Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE)

Science.gov (United States)

Manweiler, J. W.; Madanian, H.; Gerrard, A. J.; Patterson, J. D.; Mitchell, D. G.; Lanzerotti, L. J.

2017-12-01

On March 17, 2015, a large solar storm impacted the Earth's magnetosphere with a maximum negative Dst of -232 nT. We report on the temporal and spatial evolution of the proton energetic particle distributions in phase space during this storm, as measured by the Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument on board each of the Van Allen Probes. We characterize the distribution prior to onset of the storm to provide a definition of quiet time conditions. We then show how the distribution evolves during the storm noting key changes of the distribution as a function of L and MLT and showing how the pitch angle distributions change throughout the storm. These observations displayed a number of interesting features of the storm including high beta plasma conditions and multiple injections of protons into the inner magnetosphere. We present the radial changes of the distribution at storm onset and following the evolution of the distribution during storm recovery. We compare observations of the East/West asymmetry in the proton distribution before versus after onset using both Van Allen Probes A and B spacecraft observations. Finally, we note interesting changes in the distribution showing an anomalous dropout in mid-energies of the distribution and observe an outward radial propagation of this dropout during recovery.

In situ observations of Pc1 pearl pulsations by the Van Allen Probes

Science.gov (United States)

Paulson, K. W.; Smith, C. W.; Lessard, M. R.; Engebretson, M. J.; Torbert, R. B.; Kletzing, C. A.

2014-03-01

We present in situ observations of Pc1 pearl pulsations using the Van Allen Probes. These waves are often observed using ground-based magnetometers, but are rarely observed by orbiting satellites. With the Van Allen Probes, we have seen at least 14 different pearl pulsation events during the first year of operations. These new in situ measurements allow us to identify the wave classification based on local magnetic field conditions. Additionally, by using two spacecraft, we are able to observe temporal changes in the region of observation. The waves appear to be generated at an overall central frequency, as often observed on the ground, and change polarization from left- to right-handedness as they propagate into a region where they are resonant with the crossover frequency (where R- and L-mode waves have the same phase velocity). By combining both in situ and ground-based data, we have found that the region satisfying electromagnetic ion cyclotron wave generation conditions is azimuthally large while radially narrow. The observation of a similar modulation period on the ground as in the magnetosphere contradicts the bouncing wave packet mechanism of generation.

Van Allen Probes, THEMIS, GOES, and Cluster Observations of EMIC Waves, ULF Pulsations, and an Electron Flux Dropout

Science.gov (United States)

Sigsbee, K.; Kletzing, C. A.; Smith, C. W.; Macdowall, R.; Spence, H.; Reeves, G.; Blake, J. B.; Baker, D. N.; Green, J. C.; Singer, H. J.;

Pitch Angle Dependence of Drift Resonant Ions Observed by the Van Allen Probes

Science.gov (United States)

Rankin, R.; Wang, C.; Wang, Y.; Zong, Q. G.; Zhou, X.

2017-12-01

Acceleration and modulation of ring current ions by poloidal mode ULF waves is investigated. A simplified MHD model of ULF waves in a dipole magnetic field is presented that includes phase mixing to perpendicular scales determined by the ionospheric Pedersen conductivity. The wave model is combined with a full Lorentz force test particle code to study drift and drift bounce resonance wave-particle interactions. Ion trajectories are traced backward-in-time to an assumed form of the distribution function, and Liouville's method is used to reconstruct the phase space density response (PSD) poloidal mode waves observed by the Van Allen Probes. In spite of its apparent simplicity, simulations using the wave and test particle models are able to explain the acceleration of ions and energy dispersion observed by the Van Allen Probes. The paper focuses on the pitch angle evolution of the initial PSD as it responds to the action of ULF waves. An interesting aspect of the study is the formation of butterfly ion distributions as ions make periodic radial oscillations across L. Ions become trapped in an effective potential well across a limited range of L and follow trajectories that cause them to surf along constant phase fronts. The impications of this new trapping mechanism for both ions and electrons is discussed.

Deterministic methods for the relativistic Vlasov-Maxwell equations and the Van Allen belts dynamics

International Nuclear Information System (INIS)

Le Bourdiec, S.

2007-03-01

Artificial satellites operate in an hostile radiation environment, the Van Allen radiation belts, which partly condition their reliability and their lifespan. In order to protect them, it is necessary to characterize the dynamics of the energetic electrons trapped in these radiation belts. This dynamics is essentially determined by the interactions between the energetic electrons and the existing electromagnetic waves. This work consisted in designing a numerical scheme to solve the equations modelling these interactions: the relativistic Vlasov-Maxwell system of equations. Our choice was directed towards methods of direct integration. We propose three new spectral methods for the momentum discretization: a Galerkin method and two collocation methods. All of them are based on scaled Hermite functions. The scaling factor is chosen in order to obtain the proper velocity resolution. We present in this thesis the discretization of the one-dimensional Vlasov-Poisson system and the numerical results obtained. Then we study the possible extensions of the methods to the complete relativistic problem. In order to reduce the computing time, parallelization and optimization of the algorithms were carried out. Finally, we present 1Dx-3Dv (mono-dimensional for x and three-dimensional for velocity) computations of Weibel and whistler instabilities with one or two electrons species. (author)

Propagation of lower-band whistler-mode waves in the outer Van Allen belt: Systematic analysis of 11 years of multi-component data from the Cluster spacecraft

Czech Academy of Sciences Publication Activity Database

Santolík, Ondřej; Macúšová, Eva; Kolmašová, Ivana; Cornilleau-Wehrlin, N.; De Conchy, Y.

2014-01-01

Roč. 41, č. 8 (2014), s. 2729-2737 ISSN 0094-8276 R&D Projects: GA MŠk 7E12026; GA ČR GAP205/10/2279 Institutional support: RVO:68378289 Keywords : whistler-mode chorus * wave vector directions * Van Allen radiation belts Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.456, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/2014GL059815/abstract

On the interactions between energetic electrons and lightning whistler waves observed at high L-shells on Van Allen Probes

Science.gov (United States)

Zheng, H.; Holzworth, R. H., II; Brundell, J. B.; Hospodarsky, G. B.; Jacobson, A. R.; Fennell, J. F.; Li, J.

2017-12-01

Lightning produces strong broadband radio waves, called "sferics", which propagate in the Earth-ionosphere waveguide and are detected thousands of kilometers away from their source. Global real-time detection of lightning strokes including their time, location and energy, is conducted with the World Wide Lightning Location Network (WWLLN). In the ionosphere, these sferics couple into very low frequency (VLF) whistler waves which propagate obliquely to the Earth's magnetic field. A good match has previously been shown between WWLLN sferics and Van Allen Probes lightning whistler waves. It is well known that lightning whistler waves can modify the distribution of energetic electrons in the Van Allen belts by pitch angle scattering into the loss cone, especially at low L-Shells (referred to as LEP - Lightning-induced Electron Precipitation). It is an open question whether lightning whistler waves play an important role at high L-shells. The possible interactions between energetic electrons and lightning whistler waves at high L-shells are considered to be weak in the past. However, lightning is copious, and weak pitch angle scattering into the drift or bounce loss cone would have a significant influence on the radiation belt populations. In this work, we will analyze the continuous burst mode EMFISIS data from September 2012 to 2016, to find out lightning whistler waves above L = 3. Based on that, MAGEIS data are used to study the related possible wave-particle interactions. In this talk, both case study and statistical analysis results will be presented.

Ring Current Response to Different Storm Drivers. Van Allen Probes and Cluster Observations.

Science.gov (United States)

Bingham, S.; Mouikis, C.; Kistler, L. M.; Spence, H. E.; Gkioulidou, M.; Claudepierre, S. G.; Farrugia, C. J.

2015-12-01

The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), co-rotating interaction regions (CIR's), high-speed streamers and other structures. The resulting changes in the ring current particle pressure change the global magnetic field, which affects the transport of the radiation belts. In order to determine the field changes during a storm it is necessary to understand the transport, sources and losses of the particles that contribute to the ring current. The source population of the storm time ring current is the night side plasma sheet. However, it is not clear how these convecting particles affect the storm time ring current pressure development. We use Van Allen Probes and Cluster observations together with the Volland-Stern and dipole magnetic field models to determine the contribution in the ring current pressure of the plasma sheet particles convecting from the night side that are on open drift paths, during the storm evolution. We compare storms that are related to different interplanetary drivers, CME and CIR, as observed at different local times.

Space Weather Operation at KASI With Van Allen Probes Beacon Signals

Science.gov (United States)

Lee, Jongkil; Kim, Kyung-Chan; Giuseppe, Romeo; Ukhorskiy, Sasha; Sibeck, David; Kessel, Ramona; Mauk, Barry; Giles, Barbara; Gu, Bon-Jun; Lee, Hyesook; Park, Young-Deuk; Lee, Jaejin

2018-02-01

The Van Allen Probes (VAPs) are the only modern National Aeronautics and Space Administration (NASA) spacecraft broadcasting real-time data on the Earth's radiation belts for space weather operations. Since 2012, the Korea Astronomy and Space Science Institute (KASI) has contributed to the receipt of these data via a 7 m satellite-tracking antenna and used these beacon data for space weather operations. An approximately 15 min period is required from measurement to acquisition of Level-1 data. In this paper, we demonstrate the use of VAP data for monitoring space weather conditions at geostationary orbit (GEO) by highlighting the Saint Patrick's Day storm of 2015. During that storm, Probe-A observed a significant increase in the relativistic electron flux at 3 RE. Those electrons diffused outward resulting in a large increase of the electron flux >2 MeV at GEO, which potentially threatened satellite operations. Based on this study, we conclude that the combination of VAP data and National Oceanic and Atmospheric Administration-Geostationary Operational Environmental Satellite (NOAA-GOES) data can provide improved space environment information to geostationary satellite operators. In addition, the findings obtained indicate that more data-receiving sites would be necessary and data connections improved if this or a similar system were to be used as an operational data service.

Van Allen Probes, THEMIS, GOES, and Cluster Observations of EMIC Waves, ULF Pulsations, and an Electron Flux Dropout

Science.gov (United States)

Sigsbee, K.; Kletzing, C. A.; Smith, C. W.; Macdowall, R.; Spence, H.; Reeves, G.; Blake, J. B.; Baker, D. N.; Green, J. C.; Singer, H. J.;

Deterministic methods for the relativistic Vlasov-Maxwell equations and the Van Allen belts dynamics; Methodes deterministes de resolution des equations de Vlasov-Maxwell relativistes en vue du calcul de la dynamique des ceintures de Van Allen

Energy Technology Data Exchange (ETDEWEB)

Le Bourdiec, S

2007-03-15

Artificial satellites operate in an hostile radiation environment, the Van Allen radiation belts, which partly condition their reliability and their lifespan. In order to protect them, it is necessary to characterize the dynamics of the energetic electrons trapped in these radiation belts. This dynamics is essentially determined by the interactions between the energetic electrons and the existing electromagnetic waves. This work consisted in designing a numerical scheme to solve the equations modelling these interactions: the relativistic Vlasov-Maxwell system of equations. Our choice was directed towards methods of direct integration. We propose three new spectral methods for the momentum discretization: a Galerkin method and two collocation methods. All of them are based on scaled Hermite functions. The scaling factor is chosen in order to obtain the proper velocity resolution. We present in this thesis the discretization of the one-dimensional Vlasov-Poisson system and the numerical results obtained. Then we study the possible extensions of the methods to the complete relativistic problem. In order to reduce the computing time, parallelization and optimization of the algorithms were carried out. Finally, we present 1Dx-3Dv (mono-dimensional for x and three-dimensional for velocity) computations of Weibel and whistler instabilities with one or two electrons species. (author)

Energetic Proton Spectra Measured by the Van Allen Probes

Science.gov (United States)

Summers, Danny; Shi, Run; Engebretson, Mark J.; Oksavik, Kjellmar; Manweiler, Jerry W.; Mitchell, Donald G.

2017-10-01

We test the hypothesis that pitch angle scattering by electromagnetic ion cyclotron (EMIC) waves can limit ring current proton fluxes. For two chosen magnetic storms, during 17-20 March 2013 and 17-20 March 2015, we measure proton energy spectra in the region 3 ≤ L ≤ 6 using the RBSPICE-B instrument on the Van Allen Probes. The most intense proton spectra are observed to occur during the recovery periods of the respective storms. Using proton precipitation data from the POES (NOAA and MetOp) spacecraft, we deduce that EMIC wave action was prevalent at the times and L-shell locations of the most intense proton spectra. We calculate limiting ring current proton energy spectra from recently developed theory. Comparisons between the observed proton energy spectra and the theoretical limiting spectra show reasonable agreement. We conclude that the measurements of the most intense proton spectra are consistent with self-limiting by EMIC wave scattering.

Ion spectral structures observed by the Van Allen Probes

Science.gov (United States)

Ferradas, C.; Zhang, J.; Spence, H. E.; Kistler, L. M.; Larsen, B.; Reeves, G. D.; Skoug, R. M.; Funsten, H. O.

2015-12-01

During the last decades several missions have recorded the presence of dynamic spectral features of energetic ions in the inner magnetosphere. Previous studies have reported single "nose-like" structures occurring alone and simultaneous nose-like structures (up to three). These ion structures are named after the characteristic shapes of energy bands or gaps in the energy-time spectrograms of in situ measured ion fluxes. They constitute the observational signatures of ion acceleration, transport, and loss in the global magnetosphere. The HOPE mass spectrometer onboard the Van Allen Probes measures energetic hydrogen, helium, and oxygen ions near the inner edge of the plasma sheet, where these ion structures are observed. We present a statistical study of nose-like structures, using 2-years measurements from the HOPE instrument. The results provide important details about the spatial distribution (dependence on geocentric distance), spectral features of the structures (differences among species), and geomagnetic conditions under which these structures occur.

The Inner Magnetosphere Plasma Response to Interplanetary Shocks: Van Allen Probes HOPE Observations

Science.gov (United States)

Winter, L. M.; Denton, M.; Ferradas, C.; Henderson, M. G.; Larsen, B.; Reeves, G.; Skoug, R. M.; Thomsen, M. F.

2017-12-01

The Van Allen Probes' Helium, Oxygen, Proton, and Electron (HOPE) sensors measure ion and electron populations in the plasmasphere, plasma sheet, and lower-energy ring current, providing unique observations at low energies (0.001-50 keV) and low L-shell (down to 1.5 RE). We use the capabilities of these two spacecraft to probe changes in the low energy particles in response to interplanetary (IP) shocks. We focus on changes in the plasma energies, composition, and pitch angle distributions following IP shocks and storm sudden commencements from 2012-2017 through a comparison of HOPE observations preceding and post shock.

Van Allen Probe Observations of Chorus Wave Activity, Source and Seed electrons, and the Radiation Belt Response During ICME and CIR Storms

Science.gov (United States)

Bingham, S.; Mouikis, C.; Kistler, L. M.; Farrugia, C. J.; Paulson, K. W.; Huang, C. L.; Boyd, A. J.; Spence, H. E.; Kletzing, C.

2017-12-01

Whistler mode chorus waves are electromagnetic waves that have been shown to be a major contributor to enhancements in the outer radiation belt during geomagnetic storms. The temperature anisotropy of source electrons (10s of keV) provides the free energy for chorus waves, which can accelerate sub-relativistic seed electrons (100s of keV) to relativistic energies. This study uses Van Allen Probe observations to examine the excitation and plasma conditions associated with chorus wave observations, the development of the seed population, and the outer radiation belt response in the inner magnetosphere, for 25 ICME and 35 CIR storms. Plasma data from the Helium Oxygen Proton Electron (HOPE) instrument and magnetic field measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) are used to identify chorus wave activity and to model a linear theory based proxy for chorus wave growth. A superposed epoch analysis shows a peak of chorus wave power on the dawnside during the storm main phase that spreads towards noon during the storm recovery phase. According to the linear theory results, this wave activity is driven by the enhanced convection driving plasma sheet electrons across the dayside. Both ICME and CIR storms show comparable levels of wave growth. Plasma data from the Magnetic Electron Ion Spectrometer (MagEIS) and the Relativistic Electron Proton Telescope (REPT) are used to observe the seed and relativistic electrons. A superposed epoch analysis of seed and relativistic electrons vs. L shows radiation belt enhancements with much greater frequency in the ICME storms, coinciding with a much stronger and earlier seed electron enhancement in the ICME storms.

Space Radiation

Energy Technology Data Exchange (ETDEWEB)

Corliss, William R.

1968-01-01

This booklet discusses three kinds of space radiation, cosmic rays, Van Allen Belts, and solar plasma. Cosmic rays are penetrating particles that we cannot see, hear or feel, which come from distant stars. Van Allen Belts, named after their discoverer are great belts of protons and electrons that the earth has captured in its magnetic trap. Solar plasma is a gaseous, electrically neutral mixture of positive and negative ions that the sun spews out from convulsed regions on its surface.

Void structure of O+ ions in the inner magnetosphere observed by the Van Allen Probes

Science.gov (United States)

Nakayama, Y.; Ebihara, Y.; Ohtani, S.; Gkioulidou, M.; Takahashi, K.; Kistler, L. M.; Tanaka, T.

2016-12-01

The Van Allen Probes Helium Oxygen Proton Electron instrument observed a new type of enhancement of O+ ions in the inner magnetosphere during substorms. As the satellite moved outward in the premidnight sector, the flux of the O+ ions with energy 10 keV appeared first in the energy-time spectrograms. Then, the enhancement of the flux spread toward high and low energies. The enhanced flux of the O+ ions with the highest energy remained, whereas the flux of the ions with lower energy vanished near apogee, forming what we call the void structure. The structure cannot be found in the H+ spectrogram. We studied the generation mechanism of this structure by using numerical simulation. We traced the trajectories of O+ ions in the electric and magnetic fields from the global magnetohydrodynamics simulation and calculated the flux of O+ ions in the inner magnetosphere in accordance with the Liouville theorem. The simulated spectrograms are well consistent with the ones observed by Van Allen Probes. We suggest the following processes. (1) When magnetic reconnection starts, an intensive equatorward and tailward plasma flow appears in the plasma lobe. (2) The flow transports plasma from the lobe to the plasma sheet where the radius of curvature of the magnetic field line is small. (3) The intensive dawn-dusk electric field transports the O+ ions earthward and accelerates them nonadiabatically to an energy threshold; (4) the void structure appears at energies below the threshold.

Shielding of manned space stations against Van Allen Belt protons: a preliminary scoping study

International Nuclear Information System (INIS)

Santoro, R.T.; Alsmiller, R.G. Jr.; Barnes, J.M.; Corbin, J.M.

1986-09-01

Calculated results are presented to aid in the design of the shielding required to protect astronauts in a space station that is orbiting through the Van Allen proton belt. The geometry considered - a spherical shell shield with a spherical tissue phantom at its center - is only a very approximate representation of an actual space station, but this simple geometry makes it possible to consider a wide range of possible shield materials. Both homogeneous and laminated shields are considered. Also, an approximation procedure - the equivalent thickness approximation - that allows dose rates to be estimated for any shield material or materials from the dose rates for an aluminum shield is presented and discussed

Electron dropout echoes induced by interplanetary shock: Van Allen Probes observations

International Nuclear Information System (INIS)

Hao, Y. X.; Zong, Q.-G.; Zhou, X.-Z.; Fu, S. Y.; Rankin, R.

2016-01-01

On 23 November 2012, a sudden dropout of the relativistic electron flux was observed after an interplanetary shock arrival. The dropout peaks at ~1 MeV and more than 80% of the electrons disappeared from the drift shell. Van Allen twin Probes observed a sharp electron flux dropout with clear energy dispersion signals. The repeating flux dropout and recovery signatures, or “dropout echoes”, constitute a new phenomenon referred to as a “drifting electron dropout” with a limited initial spatial range. The azimuthal range of the dropout is estimated to be on the duskside, from ~1300 to 0100 LT. We then conclude that the shock-induced electron dropout is not caused by the magnetopause shadowing. Furthermore, the dropout and consequent echoes suggest that the radial migration of relativistic electrons is induced by the strong dusk-dawn asymmetric interplanetary shock compression on the magnetosphere.

Van Allen Probes, THEMIS, GOES, and Cluster observations of EMIC waves, ULF pulsations, and an electron flux dropout

Czech Academy of Sciences Publication Activity Database

Sigsbee, K.; Kletzing, C. A.; Smith, C. W.; MacDowall, R.; Spence, H.; Reeves, G.; Blake, J. B.; Baker, D. N.; Green, J. C.; Singer, H. J.; Carr, C.; Santolík, Ondřej

2016-01-01

Roč. 121, č. 3 (2016), s. 1990-2008 ISSN 2169-9380 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : EMIC waves * ULF pulsations * electron flux dropouts * Dst effect * magnetopause shadowing * Van Allen Probes Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2014JA020877/full

Propagation of Dipolarization Signatures Observed by the Van Allen Probes in the Inner Magnetosphere

Science.gov (United States)

Ohtani, S.; Motoba, T.; Gkioulidou, M.; Takahashi, K.; Kletzing, C.

2017-12-01

Dipolarization, the change of the local magnetic field from a stretched to a more dipolar configuration, is one of the most fundamental processes of magnetospheric physics. It is especially critical for the dynamics of the inner magnetosphere. The associated electric field accelerates ions and electrons and transports them closer to Earth. Such injected ions intensify the ring current, and electrons constitute the seed population of the radiation belt. Those ions and electrons may also excite various waves that play important roles in the enhancement and loss of the radiation belt electrons. Despite such critical consequences, the general characteristics of dipolarization in the inner magnetosphere still remain to be understood. The Van Allen Probes mission, which consists of two probes that orbit through the equatorial region of the inner magnetosphere, provides an ideal opportunity to examine dipolarization signatures in the core of the ring current. In the present study we investigate the spatial expansion of the dipolarization region by examining the correlation and time delay of dipolarization signatures observed by the two probes. Whereas in general it requires three-point measurements to deduce the propagation of a signal on a certain plane, we statically examined the observed time delays and found that dipolarization signatures tend to propagate radially inward as well as away from midnight. In this paper we address the propagation of dipolarization signatures quantitatively and compare with the propagation velocities reported previously based on observations made farther away from Earth. We also discuss how often and under what conditions the dipolarization region expands.

Multipoint Observations of Energetic Particle Injections and Substorm Activity During a Conjunction Between Magnetospheric Multiscale (MMS) and Van Allen Probes

Science.gov (United States)

Turner, D. L.; Fennell, J. F.; Blake, J. B.; Claudepierre, S. G.; Clemmons, J. H.; Jaynes, A. N.; Leonard, T.; Baker, D. N.; Cohen, I. J.; Gkioulidou, M.; Ukhorskiy, A. Y.; Mauk, B. H.; Gabrielse, C.; Angelopoulos, V.; Strangeway, R. J.; Kletzing, C. A.; Le Contel, O.; Spence, H. E.; Torbert, R. B.; Burch, J. L.; Reeves, G. D.

2017-11-01

This study examines multipoint observations during a conjunction between Magnetospheric Multiscale (MMS) and Van Allen Probes on 7 April 2016 in which a series of energetic particle injections occurred. With complementary data from Time History of Events and Macroscale Interactions during Substorms, Geotail, and Los Alamos National Laboratory spacecraft in geosynchronous orbit (16 spacecraft in total), we develop new insights on the nature of energetic particle injections associated with substorm activity. Despite this case involving only weak substorm activity (maximum AE energy wave activity is also established from Van Allen Probes and MMS. Drift mapping using a simplified magnetic field model provides estimates of the dispersionless injection boundary locations as a function of universal time, magnetic local time, and L shell. The analysis reveals that at least five electron injections, which were localized in magnetic local time, preceded a larger injection of both electrons and ions across nearly the entire nightside of the magnetosphere near geosynchronous orbit. The larger ion and electron injection did not penetrate to L < 6.6, but several of the smaller electron injections penetrated to L < 6.6. Due to the discrepancy between the number, penetration depth, and complexity of electron versus ion injections, this event presents challenges to the current conceptual models of energetic particle injections.

Space Weather Effects in the Earth's Radiation Belts

Science.gov (United States)

Baker, D. N.; Erickson, P. J.; Fennell, J. F.; Foster, J. C.; Jaynes, A. N.; Verronen, P. T.

2018-02-01

The first major scientific discovery of the Space Age was that the Earth is enshrouded in toroids, or belts, of very high-energy magnetically trapped charged particles. Early observations of the radiation environment clearly indicated that the Van Allen belts could be delineated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. The energy distribution, spatial extent and particle species makeup of the Van Allen belts has been subsequently explored by several space missions. Recent observations by the NASA dual-spacecraft Van Allen Probes mission have revealed many novel properties of the radiation belts, especially for electrons at highly relativistic and ultra-relativistic kinetic energies. In this review we summarize the space weather impacts of the radiation belts. We demonstrate that many remarkable features of energetic particle changes are driven by strong solar and solar wind forcings. Recent comprehensive data show broadly and in many ways how high energy particles are accelerated, transported, and lost in the magnetosphere due to interplanetary shock wave interactions, coronal mass ejection impacts, and high-speed solar wind streams. We also discuss how radiation belt particles are intimately tied to other parts of the geospace system through atmosphere, ionosphere, and plasmasphere coupling. The new data have in many ways rewritten the textbooks about the radiation belts as a key space weather threat to human technological systems.

Kalman Filtering and Smoothing of the Van Allen Probes Observations to Estimate the Radial, Energy and Pitch Angle Diffusion Rates

Science.gov (United States)

Podladchikova, T.; Shprits, Y.; Kellerman, A. C.

2015-12-01

The Kalman filter technique combines the strengths of new physical models of the Earth's radiation belts with long-term spacecraft observations of electron fluxes and therefore provide an extremely useful method for the analysis of the state and evolution of the electron radiation belts. However, to get the reliable data assimilation output, the Kalman filter application is confronted with a set of fundamental problems. E.g., satellite measurements are usually limited to a single location in space, which confines the reconstruction of the global evolution of the radiation environment. The uncertainties arise from the imperfect description of the process dynamics and the presence of observation errors, which may cause the failure of data assimilation solution. The development of adaptive Kalman filter that combines the Van Allen Probes data and 3-D VERB code, its accurate customizations in the reconstruction of model describing the phase space density (PSD) evolution, extension of the possibilities to use measurement information, and the model adjustment by developing the identification techniques of model and measurement errors allowed us to reveal hidden and implicit regularities of the PSD dynamics and obtain quantitative and qualitative estimates of radial, energy and pitch angle diffusion characteristics from satellite observations. In this study we propose an approach to estimate radial, energy and pitch angle diffusion rates, as well as the direction of their propagation.

An improved sheath impedance model for the Van Allen Probes EFW instrument: Effects of the spin axis antenna

Czech Academy of Sciences Publication Activity Database

Hartley, D. P.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Bounds, S. R.; Averkamp, T. F.; Bonnell, J. W.; Santolík, Ondřej; Wygant, J. R.

2017-01-01

Roč. 122, č. 4 (2017), s. 4420-4429 ISSN 2169-9380 R&D Projects: GA MŠk(CZ) LH15304 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : antenna sheath impedance * electric field * Van Allen Probes * EFW * EMFISIS * whistler mode waves Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016JA023597/abstract

Using the cold plasma dispersion relation and whistler mode waves to quantify the antenna sheath impedance of the Van Allen Probes EFW instrument

Czech Academy of Sciences Publication Activity Database

Hartley, D. P.; Kletzing, C. A.; Kurth, W. S.; Bounds, S. R.; Averkamp, T. F.; Hospodarsky, G. B.; Wygant, J. R.; Bonnell, J. W.; Santolík, Ondřej; Watt, C. E. J.

2016-01-01

Roč. 121, č. 5 (2016), s. 4590-4606 ISSN 2169-9380 R&D Projects: GA MŠk(CZ) LH15304 Institutional support: RVO:68378289 Keywords : EFW * EMFISIS * plasmaspheric hiss * sheath impedance * Van Allen Probes * whistler mode chorus Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016JA022501/abstract

Van Allen Probes Measurements of Energetic Particle Deep Penetration Into the Low L Region (L Storm on 8 April 2016

Science.gov (United States)

Zhao, H.; Baker, D. N.; Califf, S.; Li, X.; Jaynes, A. N.; Leonard, T.; Kanekal, S. G.; Blake, J. B.; Fennell, J. F.; Claudepierre, S. G.; Turner, D. L.; Reeves, G. D.; Spence, H. E.

2017-12-01

Using measurements from the Van Allen Probes, a penetration event of tens to hundreds of keV electrons and tens of keV protons into the low L shells (L electric field represented by the Volland-Stern model or a uniform dawn-dusk electric field model based on the electric field measurements. It suggests that the underlying physical mechanism responsible for energetic electron deep penetration, which is very important for fully understanding energetic electron dynamics in the low L shells, should be MLT localized.

A Telescopic and Microscopic Examination of Acceleration in the June 2015 Geomagnetic Storm: Magnetospheric Multiscale and Van Allen Probes Study of Substorm Particle Injection

Science.gov (United States)

Baker, D. N.; Jaynes, A. N.; Turner, D. L.; Nakamura, R.; Schmid, D.; Mauk, B. H.; Cohen, I. J.; Fennell, J. F.; Blake, J. B.; Strangeway, R. J.;

Using ACE Observations of Interplanetary Particles and Magnetic Fields as Possible Contributors to Variations Observed at Van Allen Probes during Major events in 2013

Science.gov (United States)

Armstrong, T. P.; Manweiler, J. W.; Gerrard, A. J.; Gkioulidou, M.; Lanzerotti, L. J.; Patterson, J. D.

2013-12-01

Observations from ACE EPAM including energy spectra of protons, helium, and oxygen will be prepared for coordinated use in estimating the direct and indirect access of energetic particles to inner and outer geomagnetic trapping zones. Complete temporal coverage from ACE at 12 seconds, 5 minutes, 17 minutes, hourly and daily cadences will be used to catalog interplanetary events arriving at Earth including interplanetary magnetic field sector boundaries, interplanetary shocks, and interplanetary coronal mass ejections, ICMEs. The first 6 months of 2013 have included both highly disturbed times, March 17 and May 22, and extended quiet periods of little or no variations. Among the specific questions that ACE and Van Allen Probes coordinated observations may aid in resolving are: 1. How much, if any, direct capture of interplanetary energetic particles occurs and what conditions account for it? 2. How much influence do interplanetary field and particle variations have on energization and/or loss of geomagnetically trapped populations? The poster will also present important links and describe methods and important details of access to numerically expressed ACE EPAM and Van Allen Probes RBSPICE observations that can be flexibly and easily accessed via the internet for student and senior researcher use.

Rapid flattening of butterfly pitch angle distributions of radiation belt electrons by whistler-mode chorus

Science.gov (United States)

Yang, Chang; Su, Zhenpeng; Xiao, Fuliang; Zheng, Huinan; Wang, Yuming; Wang, Shui; Spence, H. E.; Reeves, G. D.; Baker, D. N.; Blake, J. B.; Funsten, H. O.

2016-08-01

Van Allen radiation belt electrons exhibit complex dynamics during geomagnetically active periods. Investigation of electron pitch angle distributions (PADs) can provide important information on the dominant physical mechanisms controlling radiation belt behaviors. Here we report a storm time radiation belt event where energetic electron PADs changed from butterfly distributions to normal or flattop distributions within several hours. Van Allen Probes observations showed that the flattening of butterfly PADs was closely related to the occurrence of whistler-mode chorus waves. Two-dimensional quasi-linear STEERB simulations demonstrate that the observed chorus can resonantly accelerate the near-equatorially trapped electrons and rapidly flatten the corresponding electron butterfly PADs. These results provide a new insight on how chorus waves affect the dynamic evolution of radiation belt electrons.

Rapid flattening of butterfly pitch angle distributions of radiation belt electrons by whistler-mode chorus

International Nuclear Information System (INIS)

Yang, Chang; Changsha University of Science and Technology, Changsha; Su, Zhenpeng; Xiao, Fuliang; Zheng, Huinan

2016-01-01

Van Allen radiation belt electrons exhibit complex dynamics during geomagnetically active periods. Investigation of electron pitch angle distributions (PADs) can provide important information on the dominant physical mechanisms controlling radiation belt behaviors. In this paper, we report a storm time radiation belt event where energetic electron PADs changed from butterfly distributions to normal or flattop distributions within several hours. Van Allen Probes observations showed that the flattening of butterfly PADs was closely related to the occurrence of whistler-mode chorus waves. Two-dimensional quasi-linear STEERB simulations demonstrate that the observed chorus can resonantly accelerate the near-equatorially trapped electrons and rapidly flatten the corresponding electron butterfly PADs. Finally, these results provide a new insight on how chorus waves affect the dynamic evolution of radiation belt electrons.

Subauroral Polarization Streams (SAPS) Duration as Determined From Van Allen Probe Successive Electric Drift Measurements

Science.gov (United States)

Lejosne, Solène; Mozer, F. S.

2017-09-01

We examine a characteristic feature of the magnetosphere-ionosphere coupling, namely, the persistent and latitudinally narrow bands of rapid westward ion drifts called the subauroral polarization streams (SAPS). Despite countless works on SAPS, information relative to their durations is lacking. Here we report on the first statistical analysis of more than 200 near-equatorial SAPS observations based on more than 2 years of Van Allen Probe electric drift measurements. First, we present results relative to SAPS radial locations and amplitudes. Then, we introduce two different ways to estimate SAPS durations. In both cases, SAPS activity is estimated to last for about 9 h on average. However, our estimates for SAPS duration are limited either by the relatively long orbital periods of the spacecraft or by the relatively small number of observations involved. Fifty percent of the events fit within the time interval [0;18] hours.

Fast Magnetosonic Waves Observed by Van Allen Probes: Testing Local Wave Excitation Mechanism

Science.gov (United States)

Min, Kyungguk; Liu, Kaijun; Wang, Xueyi; Chen, Lunjin; Denton, Richard E.

2018-01-01

Linear Vlasov theory and particle-in-cell (PIC) simulations for electromagnetic fluctuations in a homogeneous, magnetized, and collisionless plasma are used to investigate a fast magnetosonic wave event observed by the Van Allen Probes. The fluctuating magnetic field observed exhibits a series of spectral peaks at harmonics of the proton cyclotron frequency Ωp and has a dominant compressional component, which can be classified as fast magnetosonic waves. Furthermore, the simultaneously observed proton phase space density exhibits positive slopes in the perpendicular velocity space, ∂fp/∂v⊥>0, which can be a source for these waves. Linear theory analyses and PIC simulations use plasma and field parameters measured in situ except that the modeled proton distribution is modified to have larger ∂fp/∂v⊥ under the assumption that the observed distribution corresponds to a marginally stable state when the distribution has already been scattered by the excited waves. The results show that the positive slope is the source of the proton cyclotron harmonic waves at propagation quasi-perpendicular to the background magnetic field, and as a result of interactions with the excited waves the evolving proton distribution progresses approximately toward the observed distribution.

Charging of the Van Allen Probes: Theory and Simulations

Science.gov (United States)

Delzanno, G. L.; Meierbachtol, C.; Svyatskiy, D.; Denton, M.

2017-12-01

The electrical charging of spacecraft has been a known problem since the beginning of the space age. Its consequences can vary from moderate (single event upsets) to catastrophic (total loss of the spacecraft) depending on a variety of causes, some of which could be related to the surrounding plasma environment, including emission processes from the spacecraft surface. Because of its complexity and cost, this problem is typically studied using numerical simulations. However, inherent unknowns in both plasma parameters and spacecraft material properties can lead to inaccurate predictions of overall spacecraft charging levels. The goal of this work is to identify and study the driving causes and necessary parameters for particular spacecraft charging events on the Van Allen Probes (VAP) spacecraft. This is achieved by making use of plasma theory, numerical simulations, and on-board data. First, we present a simple theoretical spacecraft charging model, which assumes a spherical spacecraft geometry and is based upon the classical orbital-motion-limited approximation. Some input parameters to the model (such as the warm plasma distribution function) are taken directly from on-board VAP data, while other parameters are either varied parametrically to assess their impact on the spacecraft potential, or constrained through spacecraft charging data and statistical techniques. Second, a fully self-consistent numerical simulation is performed by supplying these parameters to CPIC, a particle-in-cell code specifically designed for studying plasma-material interactions. CPIC simulations remove some of the assumptions of the theoretical model and also capture the influence of the full geometry of the spacecraft. The CPIC numerical simulation results will be presented and compared with on-board VAP data. This work will set the foundation for our eventual goal of importing the full plasma environment from the LANL-developed SHIELDS framework into CPIC, in order to more accurately

The evolution of ring current ion energy density and energy content during geomagnetic storms based on Van Allen Probes measurements

International Nuclear Information System (INIS)

Zhao, H.; University of Colorado, Boulder, CO; Li, X.; University of Colorado, Boulder, CO; Baker, D. N.

2015-01-01

Enabled by the comprehensive measurements from the Magnetic Electron Ion Spectrometer (MagEIS), Helium Oxygen Proton Electron mass spectrometer (HOPE), and Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instruments onboard Van Allen Probes in the heart of the radiation belt, the relative contributions of ions with different energies and species to the ring current energy density and their dependence on the phases of geomagnetic storms are quantified. The results show that lower energy (<50 keV) protons enhance much more often and also decay much faster than higher-energy protons. During the storm main phase, ions with energies <50 keV contribute more significantly to the ring current than those with higher energies; while the higher-energy protons dominate during the recovery phase and quiet times. The enhancements of higher-energy proton fluxes as well as energy content generally occur later than those of lower energy protons, which could be due to the inward radial diffusion. For the 29 March 2013 storm we investigated in detail that the contribution from O + is ~25% of the ring current energy content during the main phase and the majority of that comes from <50 keV O + . This indicates that even during moderate geomagnetic storms the ionosphere is still an important contributor to the ring current ions. Using the Dessler-Parker-Sckopke relation, the contributions of ring current particles to the magnetic field depression during this geomagnetic storm are also calculated. In conclusion, the results show that the measured ring current ions contribute about half of the Dst depression.

Energy resolution in liquid argon doped with allene

International Nuclear Information System (INIS)

Ichinose, H.; Doke, T.; Masuda, K.; Shibamura, E.

1989-01-01

Studies have been made on liquid argon as detection medium with large volume and good energy and position resolution. It is advantageous to dope liquid argon with molecules with an ionization potential lower than the energy of scintillation light. In the present work, the energy resolution for 5.305MeV alpha particles is examined, and the effect of allene added to liquid argon is investigated. Some preliminary results for 976 KeV electrons are also presented. Allene is purified by two methods: (a) small-quantity purification and (b) mass purification. Three methods are tried for mixing allene with argon. Results concerning the allene purification methods, effect of allene concentration, and allene-argon mixing methods are presented. Discussion is made of the collected charge and energy resolution. It is concluded that the addition of allene to liquid argon greatly improves the energy resolution of 5.305 MeV alpha particles. The best intrinsic resolution is 1.4 percent FWHM obtained for 4 ppm allene doped liquid argon. In the case of 976 KeV electron radiation, energy resolution is not improved by adding allene to liquid argon. The best resolution is 31 KeV FWHM obtaiend for 65ppm allene doped liquid argon. (N.K.)

Space Flight Ionizing Radiation Environments

Science.gov (United States)

Koontz, Steve

2017-01-01

The space-flight ionizing radiation (IR) environment is dominated by very high-kinetic energy-charged particles with relatively smaller contributions from X-rays and gamma rays. The Earth's surface IR environment is not dominated by the natural radioisotope decay processes. Dr. Steven Koontz's lecture will provide a solid foundation in the basic engineering physics of space radiation environments, beginning with the space radiation environment on the International Space Station and moving outward through the Van Allen belts to cislunar space. The benefits and limitations of radiation shielding materials will also be summarized.

Relativistic Electron Response to the Combined Magnetospheric Impact of a Coronal Mass Ejection Overlapping with a High-Speed Stream: Van Allen Probes Observations

Science.gov (United States)

Kanekal, S. G.; Baker, D. N.; Henderson, M. G.; Li, W.; Fennell, J. F.; Zheng, Y.; Richardson, I. G.; Jones, A.; Ali, A. F.; Elkington, S. R.;

Astronaut radiation. Will it become a problem?

International Nuclear Information System (INIS)

Parker, I.

1988-01-01

The U.S. NRCP recommendations to NASA for astronauts' dose limits to deep-body, eyes and skin are discussed in outline in relation to the longer space flights (e.g. space station duties and a manned Mars mission). Cosmic rays, solar flares and trapped Van Allen belt radiation are considered. (U.K.)

The characteristic pitch angle distributions of 1 eV to 600 keV protons near the equator based on Van Allen Probes observations

Science.gov (United States)

Yue, C.; Bortnik, J.; Thorne, R. M.; Ma, Q.; An, X.; Chappell, C. R.; Gerrard, A. J.; Lanzerotti, L. J.; Shi, Q.

2017-12-01

Understanding the source and loss processes of various plasma populations is greatly aided by having accurate knowledge of their pitch angle distributions (PADs). Here, we statistically analyze 1 eV to 600 keV hydrogen (H+) PADs near the geomagnetic equator in the inner magnetosphere based on Van Allen Probes measurements, to comprehensively investigate how the H+ PADs vary with different energies, magnetic local times (MLTs), L-shells, and geomagnetic conditions. Our survey clearly indicates four distinct populations with different PADs: (1) a pancake distribution of the plasmaspheric H+ at low L-shells except for dawn sector; (2) a bi-directional field-aligned distribution of the warm plasma cloak; (3) pancake or isotropic distributions of ring current H+; (4) radiation belt particles show pancake, butterfly and isotropic distributions depending on their energy, MLT and L-shell. Meanwhile, the pancake distribution of ring current H+ moves to lower energies as L-shell increases which is primarily caused by adiabatic transport. Furthermore, energetic H+ (> 10 keV) PADs become more isotropic following the substorm injections, indicating wave-particle interactions. The radiation belt H+ butterfly distributions are identified in a narrow energy range of 100 5), which are less significant during quiet times and extend from dusk to dawn sector through midnight during substorms. The different PADs near the equator provide clues of the underlying physical processes that produce the dynamics of these different populations.

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US-CRCM

Science.gov (United States)

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching; Glocer, Alex; Valek, Phil; McComas, David; Korth, Haje; Anderson, Brian

2018-01-01

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases (dropouts) in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere-ionosphere (M-I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US-CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensification of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open-closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M-I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the global

Van Allen Probe observations of drift-bounce resonances with Pc 4 pulsations and wave–particle interactions in the pre-midnight inner magnetosphere

Directory of Open Access Journals (Sweden)

G. I. Korotova

2015-08-01

Full Text Available We present Van Allen Probe B observations of azimuthally limited, antisymmetric, poloidal Pc 4 electric and magnetic field pulsations in the pre-midnight sector of the magnetosphere from 05:40 to 06:00 UT on 1 May 2013. Oscillation periods were similar for the magnetic and electric fields and proton fluxes. The flux of energetic protons exhibited an energy-dependent response to the pulsations. Energetic proton variations were anticorrelated at medium and low energies. Although we attribute the pulsations to a drift-bounce resonance, we demonstrate that the energy-dependent response of the ion fluxes results from pulsation-associated velocities sweeping energy-dependent radial ion flux gradients back and forth past the spacecraft.

Remote sensing of electron density and ion composition using nonducted whistler observations on OGO 1 and Van Allen Probes

Science.gov (United States)

Sonwalkar, V. S.; Butler, J.; Reddy, A.

2017-12-01

We present a new method to remotely measure magnetospheric electron density and ion composition using lightning generated nonducted whistlers observed on a satellite. Electron and ion densities play important roles in magnetospheric processes such as wave-particle interactions in the equatorial region and ion-neutral dynamics in the ionosphere, and are important for calculating space weather effects such as particle precipitation, GPS scintillations, and satellite drag. The nonducted whistler resulting from a single lightning appears on a spectrogram as a series of magnetospherically reflected traces with characteristic dispersion (time delay versus frequency) and upper and lower cut off frequencies. Ray tracing simulations show that these observed characteristics depend on the magnetospheric electron density and ion composition. The cut off frequencies depend on both electron density and ion composition. The dispersion depends strongly on electron density, but weakly on ion composition. Using an iterative process to fit the measured dispersion and cutoff frequencies to those obtained from ray tracing simulations, it is possible to construct the electron and ion density profiles of the magnetosphere. We demonstrate our method by applying it to nonducted whistlers observed on OGO 1 and Van Allen probe satellites. In one instance (08 Nov 1965), whistler traces observed on OGO 1 (L = 2.4, λm = -6°) displayed a few seconds of dispersion and cutoff frequencies in the 1-10 kHz range. Ray tracing analysis showed that a diffusive equilibrium density model with the following parameters can reproduce the observed characteristics of the whistler traces: 1900 el/cc at L=2.4 and the equator, 358,000 el/cc at F2 peak (hmF2 = 220 km), the relative ion concentrations αH+ = 0.2, αHe+ = 0.2, and αO+ = 0.6 at 1000 km, and temperature 1600 K. The method developed here can be applied to whistlers observed on the past, current, and future magnetospheric satellite missions carrying

Study the Precipitation of Radiation Belt Electrons during the Rapid Dropout Events

Science.gov (United States)

Tu, W.; Cunningham, G.; Li, X.; Chen, Y.

2015-12-01

During the main phase of storms, the relativistic electron flux in the radiation belt can drop by orders of magnitude on timescales of a few hours. Where do the electrons go? This is one of the most important outstanding questions in radiation belt studies. Radiation belt electrons can be lost either by transport across the magnetopause into interplanetary space or by precipitation into the atmosphere. In this work we first conduct a survey of the MeV electron dropouts using the Van Allen Probes data in conjunction with the low-altitude measurements of precipitating electrons by 6 NOAA/POES satellites. The dropout events are categorized into three types: precipitation-loss dominant, outward radial diffusion dominant, or with contributions from both mechanisms. The survey results suggest the relative importance of precipitation and outward radial diffusion to the fast dropouts of radiation belt electrons, and their extent in L-shell and electron energy. Then, for specific events identified as dominated by precipitation loss, we use the Drift-Diffusion model, which includes the effects of azimuthal drift and pitch angle diffusion, to simulate both the electron dropout observed by Van Allen Probes and the distributions of drift-loss-cone electrons observed by multiple low-earth-orbit satellites (6 POES and the Colorado Student Space Weather Experiment). The model quantifies the electron precipitation loss and pitch angle diffusion coefficient, Dxx, with high temporal and spatial resolution. Finally, by comparing the Dxx derived from the model with those estimated from the quasi-linear theory using wave data from Van Allen Probes and other event-specific wave models, we are able to test the validity of quasi-linear theory and seek direct evidence of the wave-particle interactions during the dropouts.

Modeling Pc4 Pulsations in Two and a Half Dimensions with Comparisons to Van Allen Probes Observations

Science.gov (United States)

McEachern, Charles A.

Field line resonances---that is, Alfven waves bouncing between the northern and southern foot points of a geomagnetic field line---serve to energize magnetospheric particles through drift-resonant interactions, carry energy from high to low altitude, induce currents in the magnetosphere, and accelerate particles into the atmosphere. Wave structure and polarization significantly impact the execution these roles. The present work showcases a new two and a half dimensional code, Tuna, ideally suited to model FLRs, with the ability to consider large-but-finite azimuthal modenumbers, coupling between the poloidal, toroidal, and compressional modes, and arbitrary harmonic structure. Using Tuna, the interplay between Joule dissipation and poloidal-to-toroidal rotation is considered for both dayside and nightside conditions. An attempt is also made to demystify giant pulsations, a class of FLR knows for its distinctive ground signatures. Numerical results are supplemented by a survey of ˜700 FLRs using data from the Van Allen Probes, the first such survey to characterize each event by both polarization and harmonic. The combination of numerical and observational results suggests an explanation for the disparate distributions observed in poloidal and toroidal FLR events.

NASA's Van Allen Probes RBSP-ECT and NSF's FIREBIRD Data Products and Access to Them: An Insider's Outlook on the Inner and Outer Belts.

Science.gov (United States)

Smith, S. S.; Spence, H. E.; Geoffrey, R.; Klumpar, D. M.

2017-12-01

In this poster, we present a summary of access to data products Radiation Belt Storm Probes - Energetic Particle Composition, and Thermal plasma (RBSP-ECT) suite of NASA's Van Allen Probes mission. The RBSP-ECT science investigation (http://rbsp-ect.sr.unh.edu) measures comprehensively the near-Earth charged particle environment in order to understand the processes that control the acceleration, global distribution, and variability of radiation belt electrons and ions. RBSP-ECT data products derive from the three instrument elements that comprise the suite, which collectively covers the broad energies that define the source and seed populations, the core radiation belts, and also their highest energy ultra-relativistic extensions. These RBSP-ECT instruments include, from lowest to highest energies: the Helium, Oxygen, Proton, and Electron (HOPE) sensor, the Magnetic Electron and Ion Spectrometer (MagEIS), and the Relativistic Electron and Proton Telescope (REPT). We provide a brief overview of their principles of operation, as well as a description of the Level 1-3 data products that the HOPE, MagEIS, and REPT instruments produce, both separately and together. We provide a summary of how to access these RBSP-ECT data products at our Science Operation Center and Science Data Center (http://www.rbsp-ect.lanl.gov/rbsp_ect.php ) as well as caveats for their use. In addition, we also provide a summary of access to the data products from NSF's CubeSat mission called Focused Investigation of Relativistic Electron Burst: Intensity, Range, and Dynamics (FIREBIRD). The dual CubeSat FIREBIRD missions provide data on energetic radiation belt electrons precipitating into the atmosphere at low altitudes, which complements and is contemporary with RBSP-ECT measurements. We provide a similar summary of how to access these data (https://ssel.montana.edu/firebird2.html). Finally, in the spirit of efficiently and effectively promoting and encouraging new collaborations, we present a

Surviving radiation in space

International Nuclear Information System (INIS)

Coates, A.

1990-01-01

Radiation damage to communications, navigation and weather satellites is common and caused by high energy charged particles, mainly protons and electrons, from the Earth's Van Allen belts. The combined release and radiation effects satellite (CRRES), recently launched by the United States, will allow scientists to create far more realistic computer models of satellite radiation damage than has been the case to date. It is hoped that information thus received will allow satellite builders to protect these essential structures in future. The second aim of the CCRES mission is to study the effect of releasing artificially charged particles into the magnetosphere and the ionosphere. Spacecraft design engineers will benefit from the results produced by the CCRES mission. (UK)

The O+ contribution and role on the ring current pressure development for CMEs and CIRs using Van Allen Probes observations

Science.gov (United States)

Mouikis, C.; Bingham, S.; Kistler, L. M.; Farrugia, C. J.; Spence, H. E.; Gkioulidou, M.

2016-12-01

The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), co-rotating interaction regions (CIR's), high-speed streamers and other structures. The resulting changes in the ring current particle pressure change the global magnetic field, which affects the transport of the radiation belts. In order to determine the field changes during a storm, it is necessary to understand the transport, sources and losses of the particles that contribute to the ring current. The source population of the storm time ring current is the night side plasma sheet. We use Van Allen Probes observations to determine the ring current pressure contribution of the convecting plasma sheet H+ and O+ particles in the storm time development of the ring current. We compare storms that are related to different interplanetary drivers, CMEs and CIRs, as observed at different local times. We find that during the storm main phase most of the ring current pressure in the pre-midnight inner magnetosphere is contributed by particles on open drift paths that cause the development of a strong partial ring current that causes most of the main phase Dst drop. These particles can reach as deep as L 2 and their pressure compares to the local magnetic field pressure as deep as L 3. During the recovery phase, if these particles are not lost at the magnetopause, will become trapped and will contribute to the symmetric ring current. However, the largest difference between the CME and CIR ring current responses during the storm main and early recovery phases is caused by how the 15 - 60 keV O+ responds to these drivers.

Second harmonic poloidal waves observed by Van Allen Probes in the dusk-midnight sector

International Nuclear Information System (INIS)

Min, Kyungguk; Takahashi, Kazue; Ukhorskiy, Aleksandr Y.; Manweiler, Jerry W.; Spence, Harlan E.

2017-01-01

This paper presents observations of ultralow-frequency (ULF) waves from Van Allen Probes. The event that generated the ULF waves occurred 2 days after a minor geomagnetic storm during a geomagnetically quiet time. Narrowband pulsations with a frequency of about 7 mHz with moderate amplitudes were registered in the premidnight sector when Probe A was passing through an enhanced density region near geosynchronous orbit. Probe B, which passed through the region earlier, did not detect the narrowband pulsations but only broadband noise. Despite the single-spacecraft measurements, we were able to determine various wave properties. We find that the observed waves are a second harmonic poloidal mode propagating westward with an azimuthal wave number estimated to be ~100; the magnetic field fluctuations have a finite compressional component due to small but finite plasma beta (~0.1); the energetic proton fluxes in the energy ranging from above 10 keV to about 100 keV exhibit pulsations with the same frequency as the poloidal mode and energy-dependent phase delays relative to the azimuthal component of the electric field, providing evidence for drift-bounce resonance; and the second harmonic poloidal mode may have been excited via the drift-bounce resonance mechanism with free energy fed by the inward radial gradient of ~80 keV protons. Here, we show that the wave active region is where the plume overlaps the outer edge of ring current and suggest that this region can have a wide longitudinal extent near geosynchronous orbit.

EPICS: Allen-Bradley hardware reference manual

International Nuclear Information System (INIS)

Nawrocki, G.

1993-01-01

This manual covers the following hardware: Allen-Bradley 6008 -- SV VMEbus I/O scanner; Allen-Bradley universal I/O chassis 1771-A1B, -A2B, -A3B, and -A4B; Allen-Bradley power supply module 1771-P4S; Allen-Bradley 1771-ASB remote I/O adapter module; Allen-Bradley 1771-IFE analog input module; Allen-Bradley 1771-OFE analog output module; Allen-Bradley 1771-IG(D) TTL input module; Allen-Bradley 1771-OG(d) TTL output; Allen-Bradley 1771-IQ DC selectable input module; Allen-Bradley 1771-OW contact output module; Allen-Bradley 1771-IBD DC (10--30V) input module; Allen-Bradley 1771-OBD DC (10--60V) output module; Allen-Bradley 1771-IXE thermocouple/millivolt input module; and the Allen-Bradley 2705 RediPANEL push button module

The Distribution of Chorus and Plasmaspheric Hiss Waves in the Inner Magnetospahere as Functions of Geomagnetic Activity and Solar Wind Parameters as Observed by The Van Allen Probes.

Science.gov (United States)

Aryan, H.; Sibeck, D. G.; Balikhin, M. A.; Agapitov, O. V.; Kletzing, C.

2015-12-01

The dynamics of the radiation belts is dependent upon the acceleration and loss of radiation belt electrons that is largely determined by the interaction of georesonant wave particles with chorus and plasmaspheric hiss waves. The distribution of these waves in the inner magnetosphere is commonly presented as a function of geomagnetic activity as expressed by the geomagnetic indices (Ae, Kp, and Dst). However, it has been shown that not all geomagnetic storms necessarily increase the flux of energetic electrons at the radiation belts. In fact, almost 20% of all geomagnetic storms cause a decrease in the flux of energetic electrons, while 30% has relatively no effect. Also, the geomagnetic indices are indirect, nonspecific parameters compiled from imperfectly covered ground based measurements that lack time history. This emphasises the need to present wave distributions as a function of both geomagnetic activity and solar wind parameters, such as velocity (V), density (n), and interplanetary magnetic field component (Bz), that are known to be predominantly effective in the control of radiation belt energetic electron fluxes. This study presents the distribution of chorus and plasmaspheric hiss waves in the inner magnetosphere as functions of both geomagnetic activity and solar wind parameters for different L-shell, magnetic local time, and magnetic latitude. This study uses almost three years of data measured by the EMFISIS on board the Van Allen Probes. Initial results indicate that the intensity of chorus and plasmaspheric hiss emissions are not only dependent on the geomagnetic activity but also dependent on solar wind parameters. The largest average wave intensities are observed with equatorial chorus in the region 4

Quantitative Simulation of QARBM Challenge Events During Radiation Belt Enhancements

Science.gov (United States)

Li, W.; Ma, Q.; Thorne, R. M.; Bortnik, J.; Chu, X.

2017-12-01

Various physical processes are known to affect energetic electron dynamics in the Earth's radiation belts, but their quantitative effects at different times and locations in space need further investigation. This presentation focuses on discussing the quantitative roles of various physical processes that affect Earth's radiation belt electron dynamics during radiation belt enhancement challenge events (storm-time vs. non-storm-time) selected by the GEM Quantitative Assessment of Radiation Belt Modeling (QARBM) focus group. We construct realistic global distributions of whistler-mode chorus waves, adopt various versions of radial diffusion models (statistical and event-specific), and use the global evolution of other potentially important plasma waves including plasmaspheric hiss, magnetosonic waves, and electromagnetic ion cyclotron waves from all available multi-satellite measurements. These state-of-the-art wave properties and distributions on a global scale are used to calculate diffusion coefficients, that are then adopted as inputs to simulate the dynamical electron evolution using a 3D diffusion simulation during the storm-time and the non-storm-time acceleration events respectively. We explore the similarities and differences in the dominant physical processes that cause radiation belt electron dynamics during the storm-time and non-storm-time acceleration events. The quantitative role of each physical process is determined by comparing against the Van Allen Probes electron observations at different energies, pitch angles, and L-MLT regions. This quantitative comparison further indicates instances when quasilinear theory is sufficient to explain the observed electron dynamics or when nonlinear interaction is required to reproduce the energetic electron evolution observed by the Van Allen Probes.

Empirical Modeling of the Storm Time Innermost Magnetosphere Using Van Allen Probes and THEMIS Data: Eastward and Banana Currents

Science.gov (United States)

Stephens, G. K.; Sitnov, M. I.; Ukhorskiy, A. Y.; Roelof, E. C.; Tsyganenko, N. A.; Le, G.

2016-01-01

The structure of storm time currents in the inner magnetosphere, including its innermost region inside 4R(sub E), is studied for the first time using a modification of the empirical geomagnetic field model TS07D and new data from Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms missions. It is shown that the model, which uses basis-function expansions instead of ad hoc current modules to approximate the magnetic field, consistently improves its resolution and magnetic field reconstruction with the increase of the number of basis functions and resolves the spatial structure and evolution of the innermost eastward current. This includes a connection between the westward ring current flowing largely at R > or approx. 3R(sub E) and the eastward ring current concentrated at R storm phase. During the main phase, it is complex, with several asymmetries forming banana currents. Near SYM-H minimum, the banana current is strongest, is localized in the evening-midnight sector, and is more structured compared to the main phase. It then weakens during the recovery phase resulting in the equatorial currents to become mostly azimuthally symmetric.

Kolb in de klas: vijf docenten in het hoger onderwijs onderzoeken de waarde van Kolbs leerstijlen voor hun eigen onderwijspraktijk

NARCIS (Netherlands)

Schoonenboom, J.; Van den Heuvel, W.; Leighton, R.; Dols, L.; Visser, W.; Van Steijn, S.

2009-01-01

Deze bundel bevat de resultaten van vijf kortlopende onderzoeken door deelnemers aan de masteropleiding Teaching in Higher Education, allen docenten in het hoger onderwijs, naar de waarde van de leerstijlen van Kolb voor hun eigen lespraktijk. Uit de onderzoeken komt naar voren dat het

Sunshine-based estimation of global solar radiation on horizontal surface at Lake Van region (Turkey)

International Nuclear Information System (INIS)

Duzen, Hacer; Aydin, Harun

2012-01-01

Highlights: ► The global solar radiation at Lake Van region is estimated. ► This study is unique for the Lake Van region. ► Solar radiation around Lake Van has the highest value at the east-southeast region. ► The annual average solar energy potential is obtained as 750–2458 kWh/m 2 . ► Results can be used to estimate evaporation. - Abstract: In this study several sunshine-based regression models have been evaluated to estimate monthly average daily global solar radiation on horizontal surface of Lake Van region in the Eastern Anatolia region in Turkey by using data obtained from seven different meteorological stations. These models are derived from Angström–Prescott linear regression model and its derivatives such as quadratic, cubic, logarithmic and exponential. The performance of this regression models were evaluated by comparing the calculated clearness index and the measured clearness index. Several statistical tests were used to control the validation and goodness of the regression models in terms of the coefficient of determination, mean percent error, mean absolute percent error, mean biased error, mean absolute biased error, root mean square error and t-statistic. The results of all the regression models are within acceptable limits according to the statistical tests. However, the best performances are obtained by cubic regression model for Bitlis, Gevaş, Hakkari, Muş stations and by quadratic regression model for Malazgirt, Tatvan and Van stations to predict global solar radiation. The spatial distributions of the monthly average daily global solar radiation around the Lake Van region were obtained with interpolation of calculated solar radiation data that acquired from best fit models of the stations. The annual average solar energy potential for Lake Van region is obtained between 750 kWh/m 2 and 2485 kWh/m 2 with annual average of 1610 kWh/m 2 .

Generation of Nonlinear Electric Field Bursts in the Outer Radiation Belt through Electrons Trapping by Oblique Whistler Waves

Science.gov (United States)

Agapitov, Oleksiy; Drake, James; Mozer, Forrest

2016-04-01

Huge numbers of different nonlinear structures (double layers, electron holes, non-linear whistlers, etc. referred to as Time Domain Structures - TDS) have been observed by the electric field experiment on board the Van Allen Probes. A large part of the observed non-linear structures are associated with whistler waves and some of them can be directly driven by whistlers. The parameters favorable for the generation of TDS were studied experimentally as well as making use of 2-D particle-in-cell (PIC) simulations for the system with inhomogeneous magnetic field. It is shown that an outward propagating front of whistlers and hot electrons amplifies oblique whistlers which collapse into regions of intense parallel electric field with properties consistent with recent observations of TDS from the Van Allen Probe satellites. Oblique whistlers seed the parallel electric fields that are driven by the beams. The resulting parallel electric fields trap and heat the precipitating electrons. These electrons drive spikes of intense parallel electric field with characteristics similar to the TDSs seen in the VAP data. The decoupling of the whistler wave and the nonlinear electrostatic component is shown in PIC simulation in the inhomogeneous magnetic field system. These effects are observed by the Van Allen Probes in the radiation belts. The precipitating hot electrons propagate away from the source region in intense bunches rather than as a smooth flux.

Comparison of several methods to calculate sunshine hours from global radiation; Vergelijking van diverse methodes voor de berekening van zonneschijnduur uit globale straling

Energy Technology Data Exchange (ETDEWEB)

Schipper, J.

2004-07-01

non-scientific use of sunshine hour data. As the sensor can also be used to make accurate solar radiation measurements, scientific data can be collected at the same time. Further development resulted in an alteration of this algorithm in 1993 (Algorithm Bergman). In this study the results for 'sunshine-duration' calculated by both algorithms will be compared to measurements from the Campbell-Stokes. The results of the comparison will be discussed and concluding remarks will be given. [Dutch] Het KNMI heeft de uurlijkse waarden van zonneschijnduur vanaf 1899 opgeslagen in de klimatologische database. Deze waarden zijn de basis voor tal van klimatologische producten. Per 1-1-1993 is op alle KNMI-stations overgeschakeld op een andere methode om de zonneschijnduur te bepalen. Sinds die datum wordt niet langer de oude en vertrouwde Campbell-Stokes (brandspoor) methode gebruikt, maar is overgeschakeld op een indirecte methode, gebaseerd op globale straling. Redenen voor vernieuwing waren de nieuwe richtlijnen van het WMO. Deze trok in september 1989 de Campbell-Stokes terug als standaard meetinstrument voor de bepaling van zonneschijnduur vanwege de te grote meetonzekerheid en de klimaatgevoeligheid van de Campbell-Stokes. Het KNMI heeft daarom gekozen voor een meer indirecte methode. Slob ontwikkelde hiertoe een methode waarbij de zonneschijnduur wordt bepaald met behulp van een herleiding uit metingen van de globale straling, in het bijzonder uit de 10-minuten registraties van de waarden gemiddelde, maximum en minimum globale straling, het zogeheten 'algoritme Slob'. Met het algoritme wordt uit de genoemde informatie de zonneschijnduur per 10'-vak bepaald. De 10'-waarden zijn de basis voor de berekening van de uurwaarden en de etmaalwaarden zonneschijnduur. De methode is in de periode 1991-1993 operationeel ingevoerd. De nieuwe technieken van inzamelen maakte het mogelijk om m.b.v. hogere tijdsresolutie (10'- basis) een nauwkeurige

Woody Allen kimpus arhitektuuriga

Index Scriptorium Estoniae

2000-01-01

Woody Allen protesteerib oma uue lühifilmiga kavatsuse vastu ehitada 16-korruseline ärihoone tema New Yorgi kodu lähedale. W. Allen hindab New Yorgi ajaloolisi rajoone, mida näitab ka oma filmides

Empirical Modeling of the Storm Time Innermost Magnetosphere Using Van Allen Probes and THEMIS Data: Eastward and Banana Currents

Science.gov (United States)

Stephens, G. K.; Sitnov, M. I.; Ukhorskiy, A. Y.; Roelof, E. C.; Tsyganenko, N. A.; Le, G.

2016-01-01

The structure of storm time currents in the inner magnetosphere, including its innermost region inside 4R(sub E), is studied for the first time using a modification of the empirical geomagnetic field model TS07D and new data from Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms missions. It is shown that the model, which uses basis-function expansions instead of ad hoc current modules to approximate the magnetic field, consistently improves its resolution and magnetic field reconstruction with the increase of the number of basis functions and resolves the spatial structure and evolution of the innermost eastward current. This includes a connection between the westward ring current flowing largely at R > or approx. 3R(sub E) and the eastward ring current concentrated at R banana current' was previously inferred from the pressure distributions based on the energetic neutral atom imaging and first-principles ring current simulations. The morphology of the equatorial currents is dependent on storm phase. During the main phase, it is complex, with several asymmetries forming banana currents. Near SYM-H minimum, the banana current is strongest, is localized in the evening-midnight sector, and is more structured compared to the main phase. It then weakens during the recovery phase resulting in the equatorial currents to become mostly azimuthally symmetric.

Radial transport of high-energy oxygen ions into the deep inner magnetosphere observed by Van Allen Probes

Science.gov (United States)

Mitani, K.; Seki, K.; Keika, K.; Gkioulidou, M.; Lanzerotti, L. J.; Mitchell, D. G.; Kletzing, C.

2017-12-01

It is known that proton is main contributor of the ring current and oxygen ions can make significant contribution during major magnetic storms. Ions are supplied to the ring current by radial transport from the plasma sheet. Convective transport of lower-energy protons and diffusive transport of higher-energy protons were reported to contribute to the storm-time and quiet-time ring current respectively [e.g., Gkioulidou et al., 2016]. However, supply mechanisms of the oxygen ions are not clear. To characterize the supply of oxygen ions to the ring current during magnetic storms, we studied the properties of energetic proton and oxygen ion phase space densities (PSDs) for specific magnetic moment (μ) during the April 23-25, 2013, geomagnetic storm observed by the Van Allen Probes mission. We here report on radial transport of high-energy (μ ≥ 0.5 keV/nT) oxygen ions into the deep inner magnetosphere during the late main phase of the magnetic storm. Since protons show little change during this period, this oxygen radial transport is inferred to cause the development of the late main phase. Enhancement of poloidal magnetic fluctuations is simultaneously observed. We estimated azimuthal mode number ≤5 by using cross wavelet analysis with ground-based observation of IMAGE ground magnetometers. The fluctuations can resonate with drift and bounce motions of the oxygen ions. The results suggest that combination of the drift and drift-bounce resonances is responsible for the radial transport of high-energy oxygen ions into the deep inner magnetosphere. We also report on the radial transport of the high-energy oxygen ions into the deep inner magnetosphere during other magnetic storms.

Allene functionalization via bicyclic methylene aziridines.

Science.gov (United States)

Boralsky, Luke A; Marston, Dagmara; Grigg, R David; Hershberger, John C; Schomaker, Jennifer M

2011-04-15

The oxidative functionalization of olefins is a common method for the formation of vicinal carbon-heteroatom bonds. However, oxidative methods to transform allenes into synthetic motifs containing three contiguous carbon-heteroatom bonds are much less developed. This paper describes the use of bicyclic methylene aziridines (MAs), prepared via intramolecular allene aziridination, as scaffolds for functionalization of all three allene carbons. © 2011 American Chemical Society

Radiations and space flight; Quand les radiations font partie du voyage

Energy Technology Data Exchange (ETDEWEB)

Maalouf, M.; Vogin, G.; Foray, N. [Groupe de Radiobiologie, Inserm U836, Institut des Neurosciences, 38 - Grenoble (France); Maalouf [CNES, Dept. des Sciences de la Vie, 75 - Paris (France); Vogin, G. [Laboratoire de Radiobiologie, EA3738, Faculte de Medecine de Lyon Sud, 69- Oullins (France)

2011-02-15

A space flight is submitted to 3 main sources of radiation: cosmic radiation (4 protons/cm{sup 2}/s and 10000 times less for the heaviest particles), solar radiation (10{sup 8} protons/cm{sup 2}/s in the solar wind), the Van Allen belt around the earth: the magnetosphere traps particles and at an altitude of 500 km the proton flux can reach 100 protons/cm{sup 2}/s. If we take into account all the spatial missions performed since 1960, we get an average dose of 400 {mu}Gray per day with an average dose rate of 0.28 {mu}Gray/mn. A significant risk of radiation-induced cancer is expected for missions whose duration is over 250 days.The cataract appears to be the most likely non-cancerous health hazard due to the exposition to comic radiation. Its risk appears to have been under-estimated, particularly for doses over 8 mGray. Some studies on astronauts have shown for some a very strong predisposition for radio-induced cancers: during the reparation phase of DNA breaking due to irradiation, multiple new damages are added by the cells themselves that behave abnormally. (A.C.)

Nonlinear Whistler Wave Physics in the Radiation Belts

Science.gov (United States)

Crabtree, Chris

2016-10-01

Wave particle interactions between electrons and whistler waves are a dominant mechanism for controlling the dynamics of energetic electrons in the radiation belts. They are responsible for loss, via pitch-angle scattering of electrons into the loss cone, and energization to millions of electron volts. It has previously been theorized that large amplitude waves on the whistler branch may scatter their wave-vector nonlinearly via nonlinear Landau damping leading to important consequences for the global distribution of whistler wave energy density and hence the energetic electrons. It can dramatically reduce the lifetime of energetic electrons in the radiation belts by increasing the pitch angle scattering rate. The fundamental building block of this theory has now been confirmed through laboratory experiments. Here we report on in situ observations of wave electro-magnetic fields from the EMFISIS instrument on board NASA's Van Allen Probes that show the signatures of nonlinear scattering of whistler waves in the inner radiation belts. In the outer radiation belts, whistler mode chorus is believed to be responsible for the energization of electrons from 10s of Kev to MeV energies. Chorus is characterized by bursty large amplitude whistler mode waves with frequencies that change as a function of time on timescales corresponding to their growth. Theories explaining the chirping have been developed for decades based on electron trapping dynamics in a coherent wave. New high time resolution wave data from the Van Allen probes and advanced spectral techniques are revealing that the wave dynamics is highly structured, with sub-elements consisting of multiple chirping waves with discrete frequency hops between sub-elements. Laboratory experiments with energetic electron beams are currently reproducing the complex frequency vs time dynamics of whistler waves and in addition revealing signatures of wave-wave and beat-wave nonlinear wave-particle interactions. These new data

Multi-Point Measurements to Characterize Radiation Belt Electron Precipitation Loss

Science.gov (United States)

Blum, L. W.

2017-12-01

Multipoint measurements in the inner magnetosphere allow the spatial and temporal evolution of various particle populations and wave modes to be disentangled. To better characterize and quantify radiation belt precipitation loss, we utilize multi-point measurements both to study precipitating electrons directly as well as the potential drivers of this loss process. Magnetically conjugate CubeSat and balloon measurements are combined to estimate of the temporal and spatial characteristics of dusk-side precipitation features and quantify loss due to these events. To then understand the drivers of precipitation events, and what determines their spatial structure, we utilize measurements from the dual Van Allen Probes to estimate spatial and temporal scales of various wave modes in the inner magnetosphere, and compare these to precipitation characteristics. The structure, timing, and spatial extent of waves are compared to those of MeV electron precipitation during a few individual events to determine when and where EMIC waves cause radiation belt electron precipitation. Magnetically conjugate measurements provide observational support of the theoretical picture of duskside interaction of EMIC waves and MeV electrons leading to radiation belt loss. Finally, understanding the drivers controlling the spatial scales of wave activity in the inner magnetosphere is critical for uncovering the underlying physics behind the wave generation as well as for better predicting where and when waves will be present. Again using multipoint measurements from the Van Allen Probes, we estimate the spatial and temporal extents and evolution of plasma structures and their gradients in the inner magnetosphere, to better understand the drivers of magnetospheric wave characteristic scales. In particular, we focus on EMIC waves and the plasma parameters important for their growth, namely cold plasma density and cool and warm ion density, anisotropy, and composition.

Isomer-specific combustion chemistry in allene and propyne flames

Energy Technology Data Exchange (ETDEWEB)

Hansen, Nils; Miller, James A. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States); Westmoreland, Phillip R. [Department of Chem. Engineering, University of Massachusetts, Amherst, MA 01003 (United States); Kasper, Tina [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States); Department of Chemistry, Bielefeld University, D-33615 Bielefeld (Germany); Kohse-Hoeinghaus, Katharina [Department of Chemistry, Bielefeld University, D-33615 Bielefeld (Germany); Wang, Juan; Cool, Terrill A. [School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 (United States)

2009-11-15

A combined experimental and modeling study is performed to clarify the isomer-specific combustion chemistry in flames fueled by the C{sub 3}H{sub 4} isomers allene and propyne. To this end, mole fraction profiles of several flame species in stoichiometric allene (propyne)/O{sub 2}/Ar flames are analyzed by means of a chemical kinetic model. The premixed flames are stabilized on a flat-flame burner under a reduced pressure of 25 Torr (=33.3 mbar). Quantitative species profiles are determined by flame-sampling molecular-beam mass spectrometry, and the isomer-specific flame compositions are unraveled by employing photoionization with tunable vacuum-ultraviolet synchrotron radiation. The temperature profiles are measured by OH laser-induced fluorescence. Experimental and modeled mole fraction profiles of selected flame species are discussed with respect to the isomer-specific combustion chemistry in both flames. The emphasis is put on main reaction pathways of fuel consumption, of allene and propyne isomerization, and of isomer-specific formation of C{sub 6} aromatic species. The present model includes the latest theoretical rate coefficients for reactions on a C{sub 3}H{sub 5} potential [J.A. Miller, J.P. Senosiain, S.J. Klippenstein, Y. Georgievskii, J. Phys. Chem. A 112 (2008) 9429-9438] and for the propargyl recombination reactions [Y. Georgievskii, S.J. Klippenstein, J.A. Miller, Phys. Chem. Chem. Phys. 9 (2007) 4259-4268]. Larger peak mole fractions of propargyl, allyl, and benzene are observed in the allene flame than in the propyne flame. In these flames virtually all of the benzene is formed by the propargyl recombination reaction. (author)

Radiations and space flight

International Nuclear Information System (INIS)

Maalouf, M.; Vogin, G.; Foray, N.; Maalouf; Vogin, G.

2011-01-01

A space flight is submitted to 3 main sources of radiation: -) cosmic radiation (4 protons/cm 2 /s and 10000 times less for the heaviest particles), -) solar radiation (10 8 protons/cm 2 /s in the solar wind), -) the Van Allen belt around the earth: the magnetosphere traps particles and at an altitude of 500 km the proton flux can reach 100 protons/cm 2 /s. If we take into account all the spatial missions performed since 1960, we get an average dose of 400 μGray per day with an average dose rate of 0.28 μGray/mn. A significant risk of radiation-induced cancer is expected for missions whose duration is over 250 days.The cataract appears to be the most likely non-cancerous health hazard due to the exposition to comic radiation. Its risk appears to have been under-estimated, particularly for doses over 8 mGray. Some studies on astronauts have shown for some a very strong predisposition for radio-induced cancers: during the reparation phase of DNA breaking due to irradiation, multiple new damages are added by the cells themselves that behave abnormally. (A.C.)

Intriguing radiation signatures at aviation altitudes

Science.gov (United States)

Tobiska, W. K.

2017-12-01

The Automated Radiation Measurements for Aerospace Safety (ARMAS) project captures absorbed dose in Si with a fleet of 6 instruments on research aircraft. These dose rates are then converted to an effective dose rate. Over 325 flights since 2013 have captured global radiation at nearly all altitudes and latitudes. The radiation is predominantly caused by atmospheric neutrons and protons from galactic cosmic rays (GCRs). We have not yet obtained dose from solar energetic particle (SEP) events, which are rather rare. On 13 flights we have also measured dose rates that are up to twice the GCR background for approximately a half an hour per event while flying at higher magnetic latitudes near 60 degrees. The timing of the radiation appears to be coincident with periods of mild geomagnetic disturbances while flying above 10 km at L-shells of 3 to 6. The radiation source is best modeled as secondary gamma-ray photons caused by precipitating ultra-relativistic electrons from the outer Van Allen radiation belt originating as loss cone electrons scattered by electromagnetic ion cyclotron (EMIC) waves. We describe the observations and the lines of evidence for this intriguing new radiation source relevant to aviation crew and frequent flyers.

Star tracker and vision systems performance in a high radiation environment

DEFF Research Database (Denmark)

Jørgensen, John Leif; Riis, Troels; Betto, Maurizio

1999-01-01

A part of the payload of the second Ariane 5 prototype vehicle to be launched by Arianespace, was a small technology demonstration satellite. On October 30th, 1997, this test satellite, dubbed Teamsat, was launched into Geostationary Transfer Orbit and would as such pass the Van Allen radiation...... belts twice per orbit. One of the experiments onboard Teamsat was the so-called Autonomous Vision System (AVS). The AVS instrument is a fully autonomous star tracker with several advanced features for non-stellar object detection and tracking, real-time image compression and transmission. The objectives...... for the AVS in Teamsat were to test these functions, to validate their autonomous operation in space, and to assess the operational constraints of a high radiation environment on such processes. This paper describes the AVS experiment, and the radiation flux experienced onboard TEAMSAT. This overview...

Mapping lightning discharges on Earth with lightning-generated whistlers wave emission in space and their effects on radiation belt electrons

Science.gov (United States)

Farges, T.; Ripoll, J. F.; Santolik, O.; Kolmasova, I.; Kurth, W. S.; Hospodarsky, G. B.; Kletzing, C.

2017-12-01

It is widely accepted that the slot region of the Van Allen radiation belts is sculpted by the presence of whistler mode waves especially by plasmaspheric hiss emissions. In this work, we investigate the role of lightning-generated whistler waves (LGW), which also contribute to scatter electrons trapped in the plasmaphere but, in general, to a lesser extent due to their low mean amplitude and occurrence rate. Our goal is to revisit the characterization of LGW occurrence in the Earth's atmosphere and in space as well as the computation of LGW effects by looking at a series of particular events, among which intense events, in order to characterize maximal scattering effects. We use multicomponent measurements of whistler mode waves by the Waves instrument of Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) onboard the Van Allen Probes spacecraft as our primary data source. We combine this data set with local measurements of the plasma density. We also use the data of the World Wide Lightning Location Network in order to localize the source of lightning discharges on Earth and their radiated energy, both locally at the footprint of the spacecraft and, globally, along the drift path. We discuss how to relate the signal measured in space with the estimation of the power emitted in the atmosphere and the associated complexity. Using these unique data sets we model the coefficients of quasi-linear pitch angle diffusion and we estimate effects of these waves on radiation belt electrons. We show evidence that lightning generated whistlers can, at least in some cases, influence the radiation belt dynamics.

Quantifying the Precipitation Loss of Radiation Belt Electrons during a Rapid Dropout Event

Science.gov (United States)

Pham, K. H.; Tu, W.; Xiang, Z.

2017-12-01

Relativistic electron flux in the radiation belt can drop by orders of magnitude within the timespan of hours. In this study, we used the drift-diffusion model that includes azimuthal drift and pitch angle diffusion of electrons to simulate low-altitude electron distribution observed by POES/MetOp satellites for rapid radiation belt electron dropout event occurring on May 1, 2013. The event shows fast dropout of MeV energy electrons at L>4 over a few hours, observed by the Van Allen Probes mission. By simulating the electron distributions observed by multiple POES satellites, we resolve the precipitation loss with both high spatial and temporal resolution and a range of energies. We estimate the pitch angle diffusion coefficients as a function of energy, pitch angle, and L-shell, and calculate corresponding electron lifetimes during the event. The simulation results show fast electron precipitation loss at L>4 during the electron dropout, with estimated electron lifetimes on the order of half an hour for MeV energies. The electron loss rate show strong energy dependence with faster loss at higher energies, which suggest that this dropout event is dominated by quick and localized scattering process that prefers higher energy electrons. The estimated pitch angle diffusion rates from the model are then compared with in situ wave measurements from Van Allen Probes to uncover the underlying wave-particle-interaction mechanisms that are responsible for the fast electron precipitation. Comparing the resolved precipitation loss with the observed electron dropouts at high altitudes, our results will suggest the relative role of electron precipitation loss and outward radial diffusion to the radiation belt dropouts during storm and non-storm times, in addition to its energy and L dependence.

Direct transformation of silyl enol ethers into functionalized allenes.

Science.gov (United States)

Langer, P; Döring, M; Seyferth, D; Görls, H

2001-02-02

The first elimination reactions of silyl enol ethers to lithiated allenes are reported. These reactions allow a direct transformation of readily available silyl enol ethers into functionalized allenes. The action of three to four equivalents of lithium diisopropylamide (LDA) on silyl enol ethers results in the formation of lithiated allenes by initial allylic lithiation, subsequent elimination of a lithium silanolate, and finally, lithiation of the allene thus formed. Starting with amide-derived silyl imino ethers, lithiated ketenimines are obtained. A variety of reactions of the lithiated allenes with electrophiles (chlorosilanes, trimethylchlorostannane, dimethyl sulfate and ethanol) were carried out. Elimination of silanolate is observed only for substrates that contain the hindered SiMe2tBu or Si(iPr)3 moiety, but not for the SiMe3 group. The reaction of 1,1-dilithio-3,3-diphenylallene with ketones provides a convenient access to novel 1,1-di(hydroxymethyl)allenes which undergo a domino Nazarov-Friedel-Crafts reaction upon treatment with p-toluenesulfonic acid.

Substituent effects on dynamics at conical intersections: Allene and methyl allenes

Energy Technology Data Exchange (ETDEWEB)

Neville, Simon P. [Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5 (Canada); Wang, Yanmei [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Boguslavskiy, Andrey E.; Stolow, Albert, E-mail: albert.stolow@nrc-cnrc.gc.ca [Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5 (Canada); National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa ON K1N 6N5 (Canada); Schuurman, Michael S., E-mail: michael.schuurman@nrc-cnrc.gc.ca [Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5 (Canada); National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada)

2016-01-07

We report a joint experimental and theoretical study on the ultrafast excited state dynamics of allene and a series of its methylated analogues (1,2-butadiene, 1,1-dimethylallene, and tetramethylallene) in order to elucidate the conical intersection mediated dynamics that give rise to ultrafast relaxation to the ground electronic state. We use femtosecond time-resolved photoelectron spectroscopy (TRPES) to probe the coupled electronic-vibrational dynamics following UV excitation at 200 nm (6.2 eV). Ab initio multiple spawning (AIMS) simulations are employed to determine the mechanistic details of two competing dynamical pathways to the ground electronic state. In all molecules, these pathways are found to involve as follows: (i) twisting about the central allenic C–C–C axis followed by pyramidalization at one of the terminal carbon atoms and (ii) bending of allene moiety. Importantly, the AIMS trajectory data were used for ab initio simulations of the TRPES, permitting direct comparison with experiment. For each molecule, the decay of the TRPES signal is characterized by short (30 fs, 52 fs, 23 fs) and long (1.8 ps, 3.5 ps, [306 fs, 18 ps]) time constants for 1,2-butadiene, 1,1-dimethylallene, and tetramethylallene, respectively. However, AIMS simulations show that these time constants are only loosely related to the evolution of electronic character and actually more closely correlate to large amplitude motions on the electronic excited state, modulating the instantaneous vertical ionization potentials. Furthermore, the fully substituted tetramethylallene is observed to undergo qualitatively different dynamics, as displacements involving the relatively massive methyl groups impede direct access to the conical intersections which give rise to the ultrafast relaxation dynamics observed in the other species. These results show that the branching between the “twisting” and “bending” pathways can be modified via the selective methylation of the terminal

James A. Van Allen: The Trip to Jupiter

Science.gov (United States)

Jacobsen, Sally

1973-01-01

Discusses the research purposes and activities of the Pioneer mission, including the instruments used, data on Jupiter's radiation belt, and information about cosmic ray intensity. Included is a description of the scientist's view about the value of the space program. (CC)

Modular functionalization of allenes to aminated stereotriads.

Science.gov (United States)

Adams, Christopher S; Boralsky, Luke A; Guzei, Ilia A; Schomaker, Jennifer M

2012-07-04

Nitrogen-containing stereotriads, compounds with three adjacent stereodefined carbons, are commonly found in biologically important molecules. However, the preparation of molecules bearing these motifs can be challenging. Herein, we describe a modular oxidation protocol which converts a substituted allene to a triply functionalized amine of the form C-X/C-N/C-Y. The key step employs a Rh-catalyzed intramolecular conversion of the allene to a strained bicyclic methylene aziridine. This reactive intermediate is further elaborated to the target products, often in one reaction vessel and with effective transfer of the axial chirality of the allene to point chirality in the stereotriad.

Crafoord Symposium on Magnetospheric Physics : Achievements and Prospects

CERN Document Server

Fälthammar, C-G

1990-01-01

This book contains the proceedings of the 1989 Crafoord Symposium organized by the Royal Swedish Academy of Sciences. The scientific field for the Crafoord Prize of 1989 was decided in 1988 by the Academy to be Magnetospheric Physics. On September 27,1989 the Academy awarded the 1989 Crafoord Prize to Professor J. A. Van Allen, Iowa City, USA "for his pioneer work in space research, in particular for the discovery of the high energy charged particles that are trapped in the Earth's magnetic field and form the radiation belts -often called the Van Allen belts - around the Earth". The subject for the Crafoord Symposium, which was held on September 28-29 at the Royal Swedish Academy of Sciences in Stockholm, was Magnetospheric Physics, Achievements and Prospects. Some seventy of the world's leading scientists in magnetospheric physics (see list of participants) were invited to the Symposium. The program contained only invited papers. After the ?resentation of the Crafoord Prize Laureate, Prof. J . A. Van Allen, ...

The Global Statistical Response of the Outer Radiation Belt During Geomagnetic Storms

Science.gov (United States)

Murphy, K. R.; Watt, C. E. J.; Mann, I. R.; Jonathan Rae, I.; Sibeck, D. G.; Boyd, A. J.; Forsyth, C. F.; Turner, D. L.; Claudepierre, S. G.; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Blake, J. B.; Fennell, J.

2018-05-01

Using the total radiation belt electron content calculated from Van Allen Probe phase space density, the time-dependent and global response of the outer radiation belt during storms is statistically studied. Using phase space density reduces the impacts of adiabatic changes in the main phase, allowing a separation of adiabatic and nonadiabatic effects and revealing a clear modality and repeatable sequence of events in storm time radiation belt electron dynamics. This sequence exhibits an important first adiabatic invariant (μ)-dependent behavior in the seed (150 MeV/G), relativistic (1,000 MeV/G), and ultrarelativistic (4,000 MeV/G) populations. The outer radiation belt statistically shows an initial phase dominated by loss followed by a second phase of rapid acceleration, while the seed population shows little loss and immediate enhancement. The time sequence of the transition to the acceleration is also strongly μ dependent and occurs at low μ first, appearing to be repeatable from storm to storm.

Coordinates for Representing Radiation Belt Particle Flux

Science.gov (United States)

Roederer, Juan G.; Lejosne, Solène

2018-02-01

Fifty years have passed since the parameter "L-star" was introduced in geomagnetically trapped particle dynamics. It is thus timely to review the use of adiabatic theory in present-day studies of the radiation belts, with the intention of helping to prevent common misinterpretations and the frequent confusion between concepts like "distance to the equatorial point of a field line," McIlwain's L-value, and the trapped particle's adiabatic L* parameter. And too often do we miss in the recent literature a proper discussion of the extent to which some observed time and space signatures of particle flux could simply be due to changes in magnetospheric field, especially insofar as off-equatorial particles are concerned. We present a brief review on the history of radiation belt parameterization, some "recipes" on how to compute adiabatic parameters, and we illustrate our points with a real event in which magnetospheric disturbance is shown to adiabatically affect the particle fluxes measured onboard the Van Allen Probes.

Diastereoselective Au-Catalyzed Allene Cycloisomerizations to Highly Substituted Cyclopentenes.

Science.gov (United States)

Reeves, Ryan D; Phelps, Alicia M; Raimbach, William A T; Schomaker, Jennifer M

2017-07-07

Site- and regiocontrolled Au-catalyzed allene carbocyclizations furnish highly substituted cyclopentenes in >1:1 dr. Significant substitution on the substrate is tolerated, with potential to install five contiguous stereocenters after alkene functionalization. Major challenges include identifying a Au/Cu catalyst that controls both the relative rates of allene epimerization/cyclization and the facial selectivity in addition of a metal enolate to the allene. Experiments to achieve stereodivergent cyclizations and transform key cyclopentenes into useful synthetic building blocks are described.

Allen Ginsberg kirjutab Ameerikast

Index Scriptorium Estoniae

2003-01-01

Arvustus: Ginsberg, Allen. Ameerika : valik luuletusi 1947-1996 / koostanud ja toimetanud Hasso Krull ; inglise keelest tõlkinud Contra, Lauri Kitsnik, Hasso Krull, Andres Langemets, Margit Langemets, Jürgen Rooste, Tõnu Õnnepalu. Tallinn : Perioodika, 2003

76 FR 36318 - Safety Zone; Waterway Closure, Morgan City-Port Allen Route From Mile Marker 0 to Port Allen Lock

Science.gov (United States)

2011-06-22

... Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks. This rule is not an economically significant rule and does not create an environmental risk to health or risk to...-AA00 Safety Zone; Waterway Closure, Morgan City-Port Allen Route From Mile Marker 0 to Port Allen Lock...

Photolysis of allene-ozone mixtures at 647 nm in cryogenic matrices. Part 1. Formation of allene oxide

Science.gov (United States)

Singmaster, Karen A.; Pimentel, George C.

1989-03-01

Matrix studies of the photolytic reaction at 647 nm between allene and ozone were carried out at 12 K. Primary photoproducts include carbon monoxide, acrolein ( cis and trans), cyclopropanone, ketene, ethylene, allene oxide and formaldehyde. In Ar and Kr matrices both acrolein and cyclopropanone are produced in high yields, whereas in Xe matrices cyclopropanone is the major product. Infrared spectra for cyclopropanone and its oxygen-18 and deuterium substitutes are reported. The carbonyl stretch for cyclopropanone is observed at 1815 cm -1 in an Ar matrix. Also reported is the first synthesis of allene oxide. The carbon—carbon double bond stretch is observed at 1823.4 cm -1 and it exhibits a small oxygen-18 shift. The change in product distribution is discussed in terms of heavy atom spin—orbit enhancement of singlet—triplet excitation, so that in xenon reaction takes place on a triplet surface, whereas in argon it occurs on a singlet surface.

33 CFR 80.1440 - Port Allen, Kauai, HI.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Port Allen, Kauai, HI. 80.1440 Section 80.1440 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1440 Port Allen, Kauai, HI. A line drawn from...

Resistance of holograms made in Polaroid DMP128 photopolymer to ionizing radiation damage

International Nuclear Information System (INIS)

Golden, J.P.; Summers, G.P.; Carter, W.H.

1988-01-01

Because of their light weight and general wave-front-transforming ability, holograms appear potentially useful as beam correctors and collimators for diode-laser arrays in intersatellite optical data links. However, to survive in space a hologram must withstand damage from electrons and protons trapped in the Van Allen belts. We have found that holograms made with Polaroid DMP128 photopolymer on Suprasil-2 can withstand 63-MeV protons up to a total dose of 2 Mrad in (Si) and withstand /sup 60/Co gamma rays up to a total dose of 2 Mrad in (Si) without loss of diffraction efficiency. It appears that these holograms are sufficiently radiation hard for space application

Chemoselective allene aziridination via Ag(I) catalysis.

Science.gov (United States)

Rigoli, Jared W; Weatherly, Cale D; Vo, Brian T; Neale, Samuel; Meis, Alan R; Schomaker, Jennifer M

2013-01-18

Allene aziridination generates useful bicyclic methylene aziridine scaffolds that can be flexibly transformed into a range of stereochemically complex and densely functionalized amine-containing stereotriads. The scope of this chemistry has been limited by the poor chemoselectivity that often results when typical dinuclear Rh(II) catalysts are employed with homoallenic carbamates. Herein, Ag(I) catalysts that significantly improve the scope and yield of bicyclic methylene aziridines that can be prepared via allene aziridination are described.

Pattern-free thermal modulator via thermal radiation between Van der Waals materials

Science.gov (United States)

Liu, Xianglei; Shen, Jiadong; Xuan, Yimin

2017-10-01

Modulating heat flux provides a platform for a plethora of emerging devices such as thermal diodes, thermal transistors, and thermal memories. Here, a pattern-free noncontact thermal modulator is proposed based on the mechanical rotation between two Van der Waals films with optical axes parallel to the surfaces. A modulation contrast can reach a value higher than 5 for hexagonal Boron Nitride (hBN) films separated by a nanoscale gap distance. The dominant radiative heat exchange comes from the excitation of both Type I and Type II hyperbolic surface phonon polaritons (HSPhPs) at the vacuum-hBN interface for different orientations, while the large modulation contrast is mainly attributed to the mismatching Type I HSPhPs induced by rotation. This work opens the possibility to design cheap thermal modulators without relying on nanofabrication techniques, and paves the way to apply natural Van der Waals materials in manipulating heat currents in an active way.

Trapping in stochastic mechanics and applications to covers of clouds and radiation belts

International Nuclear Information System (INIS)

Albeverio, S.; Blanchard, P.; Combe, P.; Rodriguez, R.; Sirugue, M.; Sirugue-Collin, M.

1984-11-01

It is possible to assign a stochastic acceleration to conservative stochastic diffusion processes. As a basic assumption, this stochastic acceleration is set equal to the deterministic smooth component of the external force acting on the particle, whereas the influences of the remainder is modelled by a diffusion coefficient. In this paper, we shall try to see whether it can account for the observation in two cases: the cover of clouds of planets and the radiation belts in the planetary magnetic field. We describe the basic properties of Newtonian Diffusion Stochastic Processes and indicate their connection with Schroedinger-like equations. Furthermore we give a heuristic interpretation of the nodal surfaces as impenetrable barriers for Newtonian Stochastic Diffusion Processes. The possible applications to the observed average cloud covering in the planetary atmosphere are presented we discuss the radiation belts (Van Allen Belts) along the previous ideas

The storm time ring current dynamics and response to CMEs and CIRs using Van Allen Probes observations and CIMI simulations

Science.gov (United States)

Mouikis, Christopher; Bingham, Samuel; Kistler, Lynn; Spence, Harlan; Gkioulidou, Matina

2017-04-01

The ring current responds differently to the different solar and interplanetary storm drivers such as coronal mass injections, (CME's), and co-rotating interaction regions (CIR's). Using Van Allen Probes observations, we develop an empirical ring current model of the ring current pressure, the pressure anisotropy and the current density development during the storm phases for both types of storm drivers and for all MLTs inside L 6. Delineating the differences in the ring current development between these two drivers will aid our understanding of the ring current dynamics. We find that during the storm main phase most of the ring current pressure in the pre-midnight inner magnetosphere is contributed by particles on open drift paths that cause the development of a strong partial ring current that causes most of the main phase Dst drop. These particles can reach as deep as L 2 and their pressure compares to the local magnetic field pressure as deep as L 3. During the recovery phase, if these particles are not lost at the magnetopause, will become trapped and will contribute to the symmetric ring current. However, the largest difference between the CME and CIR ring current responses during the storm main and early recovery phases is caused by how the 15 - 60 keV O+ responds to these drivers. This empirical model is compared to the results of CIMI simulations of a CMEs and a CIRs where the model input is comprised of the superposed epoch solar wind conditions of the storms that comprise the empirical model. Different inner magnetosphere boundary conditions are tested in order to match the empirical model results. Comparing the model and simulation results improves our understanding of the ring current dynamics as part of the highly coupled inner magnetosphere system. In addition, within the framework of this empirical model, the prediction of the EMIC wave generation linear theory is tested using the observed plasma parameters and comparing with the observations of

Lower Hybrid Frequency Range Waves Generated by Ion Polarization Drift Due to Electromagnetic Ion Cyclotron Waves: Analysis of an Event Observed by the Van Allen Probe B

Science.gov (United States)

Khazanov, G. V.; Boardsen, S.; Krivorutsky, E. N.; Engebretson, M. J.; Sibeck, D.; Chen, S.; Breneman, A.

2017-01-01

We analyze a wave event that occurred near noon between 07:03 and 07:08 UT on 23 February 2014 detected by the Van Allen Probes B spacecraft, where waves in the lower hybrid frequency range (LHFR) and electromagnetic ion cyclotron (EMIC) waves are observed to be highly correlated, with Pearson correlation coefficient of approximately 0.86. We assume that the correlation is the result of LHFR wave generation by the ions polarization drift in the electric field of the EMIC waves. To check this assumption the drift velocities of electrons and H+, He+, and O+ ions in the measured EMIC wave electric field were modeled. Then the LHFR wave linear instantaneous growth rates for plasma with these changing drift velocities and different plasma compositions were calculated. The time distribution of these growth rates, their frequency distribution, and the frequency dependence of the ratio of the LHFR wave power spectral density (PSD)parallel and perpendicular to the ambient magnetic eld to the total PSD were found. These characteristics of the growth rates were compared with the corresponding characteristics of the observed LHFR activity. Reasonable agreement between these features and the strong correlation between EMIC and LHFR energy densities support the assumption that the LHFR wave generation can be caused by the ions polarization drift in the electric field of an EMIC wave.

Interview of David Elliston Allen

OpenAIRE

Allen, David

2009-01-01

Interviewed on 12 April 1983 by Jack Goody and Alan Macfarlane and filmed and edited by Sarah Harrison. Made on old and low quality equipment. An interview of the historian and naturalist David Elliston Allen

Wave-Particle Interactions Involving Correlated Electron Bursts and Whistler Chorus in Earth's Radiation Belts

Science.gov (United States)

Echterling, N.; Schriver, D.; Roeder, J. L.; Fennell, J. F.

2017-12-01

During the recovery phase of substorm plasma injections, the Van Allen Probes commonly observe events of quasi-periodic energetic electron bursts correlating with simultaneously detected upper-band, whistler-mode chorus emissions. These electron bursts exhibit narrow ranges of pitch angles (75-80° and 100-105°) and energies (20-40 keV). Electron cyclotron harmonic (ECH) emissions are also commonly detected, but typically do not display correlation with the electron bursts. To examine sources of free energy and the generation of these wave emissions, an observed electron velocity distribution on January 13, 2013 is used as the starting condition for a particle in cell (PIC) simulation. Effects of temperature anisotropy (perpendicular temperature greater than parallel temperature), the presence of a loss cone and a cold electron population on the generation of whistler and ECH waves are examined to understand wave generation and nonlinear interactions with the particle population. These nonlinear interactions produce energy diffusion along with strong pitch angle scattering into the loss cone on the order of milliseconds, which is faster than a typical bounce period of seconds. To examine the quasi-periodic nature of the electron bursts, a loss-cone recycling technique is implemented to model the effects of the periodic emptying of the loss cone and electron injection on the growth of whistler and ECH waves. The results of the simulations are compared to the Van Allen Probe observations to determine electron acceleration, heating and transport in Earth's radiation belts due to wave-particle interactions.

Radiation belt seed population and its association with the relativistic electron dynamics: A statistical study: Radiation Belt Seed Population

International Nuclear Information System (INIS)

Tang, C. L.; Wang, Y. X.; Ni, B.; Zhang, J.-C.

2017-01-01

Using the Van Allen Probes data, we study the radiation belt seed population and it associated with the relativistic electron dynamics during 74 geomagnetic storm events. Based on the flux changes of 1 MeV electrons before and after the storm peak, these storm events are divided into two groups of “non-preconditioned” and “preconditioned”. The statistical study shows that the storm intensity is of significant importance for the distribution of the seed population (336 keV electrons) in the outer radiation belt. However, substorm intensity can also be important to the evolution of the seed population for some geomagnetic storm events. For non-preconditioned storm events, the correlation between the peak fluxes and their L-shell locations of the seed population and relativistic electrons (592 keV, 1.0 MeV, 1.8 MeV, and 2.1 MeV) is consistent with the energy-dependent dynamic processes in the outer radiation belt. For preconditioned storm events, the correlation between the features of the seed population and relativistic electrons is not fully consistent with the energy-dependent processes. It is suggested that the good correlation between the radiation belt seed population and ≤1.0 MeV electrons contributes to the prediction of the evolution of ≤1.0 MeV electrons in the Earth’s outer radiation belt during periods of geomagnetic storms.

Space Radiation Environment Prediction for VLSI microelectronics devices onboard a LEO Satellite using OMERE-Trad Software

Science.gov (United States)

Sajid, Muhammad

This tutorial/survey paper presents the assessment/determination of level of hazard/threat to emerging microelectronics devices in Low Earth Orbit (LEO) space radiation environment with perigee at 300 Km, apogee at 600Km altitude having different orbital inclinations to predict the reliability of onboard Bulk Built-In Current Sensor (BBICS) fabricated in 350nm technology node at OptMA Lab. UFMG Brazil. In this context, the various parameters for space radiation environment have been analyzed to characterize the ionizing radiation environment effects on proposed BBICS. The Space radiation environment has been modeled in the form of particles trapped in Van-Allen radiation belts(RBs), Energetic Solar Particles Events (ESPE) and Galactic Cosmic Rays (GCR) where as its potential effects on Device- Under-Test (DUT) has been predicted in terms of Total Ionizing Dose (TID), Single-Event Effects (SEE) and Displacement Damage Dose (DDD). Finally, the required mitigation techniques including necessary shielding requirements to avoid undesirable effects of radiation environment at device level has been estimated /determined with assumed standard thickness of Aluminum shielding. In order to evaluate space radiation environment and analyze energetic particles effects on BBICS, OMERE toolkit developed by TRAD was utilized.

The 3D Radiation Dose Analysis For Satellite

Science.gov (United States)

Cai, Zhenbo; Lin, Guocheng; Chen, Guozhen; Liu, Xia

2002-01-01

the earth. These particles come from the Van Allen Belt, Solar Cosmic Ray and Galaxy Cosmic Ray. They have different energy and flux, varying with time and space, and correlating with solar activity tightly. These particles interact with electrical components and materials used on satellites, producing various space radiation effects, which will damage satellite to some extent, or even affect its safety. orbit. Space energy particles inject into components and materials used on satellites, and generate radiation dose by depositing partial or entire energy in them through ionization, which causes their characteristic degradation or even failure. As a consequence, the analysis and protection for radiation dose has been paid more attention during satellite design and manufacture. Designers of satellites need to analyze accurately the space radiation dose while satellites are on orbit, and use the results as the basis for radiation protection designs and ground experiments for satellites. can be calculated, using the model of the trapped proton and the trapped electron in the Van Allen Belt (AE8 and AP8). This is the 1D radiation dose analysis for satellites. Obviously, the mass shielding from the outside space to the computed point in all directions is regarded as a simple sphere shell. The actual structure of satellites, however, is very complex. When energy particles are injecting into a given equipment inside satellite from outside space, they will travel across satellite structure, other equipment, the shell of the given equipment, and so on, which depends greatly on actual layout of satellite. This complex radiation shielding has two characteristics. One is that the shielding masses for the computed point are different in different injecting directions. The other is that for different computed points, the shielding conditions vary in all space directions. Therefore, it is very difficult to tell the differences described above using the 1D radiation analysis, and

Modeling of Jupiter's electron an ion radiation belts

International Nuclear Information System (INIS)

Sicard, Angelica

2004-01-01

In the Fifties, James Van Allen showed the existence of regions of the terrestrial magnetosphere consisted of energetic particles, trapped by the magnetic field: the radiation belts. The radiation belts of the Earth were the subject of many modeling works and are studied since several years at the Departement Environnement Spatial (DESP) of ONERA. In 1998, the DESP decided to adapt the radiation belts model of the Earth, Salammbo, to radiation environment of Jupiter. A first thesis was thus carried out on the subject and a first radiation belts model of electrons of Jupiter was developed [Santos-Costa, 2001]. The aim of this second thesis is to develop a radiation belts model for protons and heavy ions. In order to validate the developed model, the comparisons between Salammbo results and observations are essential. However, the validation is difficult in the case of protons and heavy ions because in-situ measurements of the probes are very few and most of the time contaminated by very energetic electrons. To solve this problem, a very good model of electrons radiation belts is essential to confirm or cancel the contamination of protons and heavy ions measurements. Thus, in parallel to the development of the protons and heavy ions radiation belts model, the electrons models, already existing, has been improved. Then Salammbo results have been compared to the different observations available (in-situ measurements, radio-astronomical observations). The different comparisons show a very good agreement between Salammbo results and observations. (author) [fr

Nonlinear VLF Wave Physics in the Radiation Belts

Science.gov (United States)

Crabtree, C. E.; Tejero, E. M.; Ganguli, G.; Mithaiwala, M.; Rudakov, L.; Hospodarsky, G. B.; Kletzing, C.

2014-12-01

Electromagnetic VLF waves, such as whistler mode waves, both control the lifetime of trapped electrons in the radiation belts by pitch-angle scattering and are responsible for the energization of electrons during storms. Traditional approaches to understanding the influence of waves on trapped electrons have assumed that the wave characteristics (frequency spectrum, wave-normal angle distribution, etc.) were both stationary in time and amplitude independent from event to event. In situ data from modern satellite missions, such as the Van Allen probes, are showing that this assumption may not be justified. In addition, recent theoretical results [Crabtree et al. 2012] show that the threshold for nonlinear wave scattering can often be met by naturally occurring VLF waves in the magnetosphere, with wave magnetic fields of the order of 50-100 pT inside the plasmapause. Nonlinear wave scattering (Nonlinear Landau Damping) is an amplitude dependent mechanism that can strongly alter VLF wave propagation [Ganguli et al. 2010], primarily by altering the direction of propagation. Laboratory results have confirmed the dramatic change in propagation direction when the pump wave has sufficient amplitude to exceed the nonlinear threshold [Tejero et al. 2014]. Nonlinear scattering can alter the macroscopic dynamics of waves in the radiation belts leading to the formation of a long-lasting wave-cavity [Crabtree et al. 2012] and, when amplification is present, a multi-pass amplifier [Ganguli et al., 2012]. Such nonlinear wave effects can dramatically reduce electron lifetimes. Nonlinear wave dynamics such as these occur when there are more than one wave present, such a condition necessarily violates the assumption of traditional wave-normal analysis [Santolik et al., 2003] which rely on the plane wave assumption. To investigate nonlinear wave dynamics using modern in situ data we apply the maximum entropy method [Skilling and Bryan, 1984] to solve for the wave distribution function

Woody Allen, serial schlemiel ?

Directory of Open Access Journals (Sweden)

Frédérique Brisset

2011-04-01

Full Text Available Woody Allen a développé au fil des années une persona cinématographique de schlemiel new-yorkais aisément reconnaissable par le spectateur. Elle marque nombre de ses films, qu’il y apparaisse en tant qu’acteur ou y dirige des substituts comédiens comme déclinaisons de lui-même. Si cette figure prototypique est le fondement de la sérialité dans sa filmographie, il est des traits stylistiques qui en portent trace tout au long de son œuvre : la récurrence annuelle de ses réalisations, la signature formelle symbolisée par ses génériques à la typographie singulière, le rythme de ses dialogues ponctués d’interjections et l’usage de l’autocitation sont autant de procédés qui marquent son cinéma d’un sceau très personnel. Ils fonctionnent comme des clins d’œil au spectateur qui reçoit dès lors LE Woody Allen millésimé comme une invitation à retrouver son microcosme. Ainsi la sérialité se pose comme à la fois initiale et conséquentielle de son système filmique, processus de création unique dans le cinéma américain.Woody Allen has long constructed a cinematographic persona of schlemiel New- Yorker that the audience can easily identify. It impacts most of his films, whether he stars in them or directs “substitute” actors to impersonate his character. If this prototypical figure is the basis of seriality in his cinematography, serial stylistic features can also be found all along his career: the annual recurrence of his productions, the formal signature symbolised by the typography of his singular credit titles, his rhythmical interjection-punctuated dialogues and the use of self-quotation imprint a very personal seal upon his movies. They all work as a recognition signals for the audience who thus receive THE Woody Allen vintage as an invitation to re-enter his microcosm. Seriality is then both initial and consequential to his cinematographic system, a unique creative process in American film history.

Application of multi-parameter chorus and plasmaspheric hiss wave models in radiation belt modeling

Science.gov (United States)

Aryan, H.; Kang, S. B.; Balikhin, M. A.; Fok, M. C. H.; Agapitov, O. V.; Komar, C. M.; Kanekal, S. G.; Nagai, T.; Sibeck, D. G.

2017-12-01

Numerical simulation studies of the Earth's radiation belts are important to understand the acceleration and loss of energetic electrons. The Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model along with many other radiation belt models require inputs for pitch angle, energy, and cross diffusion of electrons, due to chorus and plasmaspheric hiss waves. These parameters are calculated using statistical wave distribution models of chorus and plasmaspheric hiss amplitudes. In this study we incorporate recently developed multi-parameter chorus and plasmaspheric hiss wave models based on geomagnetic index and solar wind parameters. We perform CIMI simulations for two geomagnetic storms and compare the flux enhancement of MeV electrons with data from the Van Allen Probes and Akebono satellites. We show that the relativistic electron fluxes calculated with multi-parameter wave models resembles the observations more accurately than the relativistic electron fluxes calculated with single-parameter wave models. This indicates that wave models based on a combination of geomagnetic index and solar wind parameters are more effective as inputs to radiation belt models.

Photochemical generation and 1H NMR detection of alkyl allene oxides in solution

International Nuclear Information System (INIS)

Breen, L.E.; Schepp, N.P.; Tan, C.-H.E.

2005-01-01

Irradiation of substituted 5-alkyl-4,5-epoxyvalerophenones leads to the formation of alkyl allene oxides that, in some cases, are sufficiently long-lived to be detected at room temperature by 1 H NMR spectroscopy. Absolute lifetime measurements show that the size of the alkyl group has a significant influence on the reactivity of the allene oxide, with tert-butyl allene oxide having a lifetime of 24 h in CD 3 CN at room temperature that is considerably longer than the 1.5 h lifetime of the ethyl allene oxide. The allene oxides react rapidly with water to give α-hydroxyketones. The mechanism involves nucleophilic attack to the epoxide carbon to give an enol, which can also be detected as an intermediate by 1 H NMR spectroscopy. (author)

Wave-Particle Interactions in the Earth's Radiation Belts: Recent Advances and Unprecedented Future Opportunities

Science.gov (United States)

Li, W.

2017-12-01

In the collisionless heliospheric plasmas, wave-particle interaction is a fundamental physical process in transferring energy and momentum between particles with different species and energies. This presentation focuses on one of the important wave-particle interaction processes: interaction between whistler-mode waves and electrons. Whistler-mode waves have frequencies between proton and electron cyclotron frequency and are ubiquitously present in the heliospheric plasmas including solar wind and planetary magnetospheres. I use Earth's Van Allen radiation belt as "local space laboratory" to discuss the role of whistler-mode waves in energetic electron dynamics using multi-satellite observations, theory and modeling. I further discuss solar wind drivers leading to energetic electron dynamics in the Earth's radiation belts, which is critical in predicting space weather that has broad impacts on our technological systems and society. At last, I discuss the unprecedented future opportunities of exploring space science using multi-satellite observations and state-of-the-art theory and modeling.

Astronauts Allen and Gemar during extravehicular activity (EVA) training in CCT

Science.gov (United States)

1994-01-01

Astronauts Charles D. (Sam) Gemar, and Andrew M. Allen participate in a training exercise at JSC's Crew Compartment Trainer (CCT), located in the Space Vehicle Mockup Facility. Gemar sits inside the airlock as Allen reviews procedures for EVA.

Empirical radiation belt models: Comparison with in situ data and implications for environment definition

Science.gov (United States)

de Soria-Santacruz Pich, Maria; Jun, Insoo; Evans, Robin

2017-09-01

The empirical AP8/AE8 model has been the de facto Earth's radiation belts engineering reference for decades. The need from the community for a better model incubated the development of AP9/AE9/SPM, which addresses several shortcomings of the old model. We provide additional validation of AP9/AE9 by comparing in situ electron and proton data from Jason-2, Polar Orbiting Environmental Satellites (POES), and the Van Allen Probes spacecraft with the 5th, 50th, and 95th percentiles from AE9/AP9 and with the model outputs from AE8/AP8. The relatively short duration of Van Allen Probes and Jason-2 missions means that their measurements are most certainly the result of specific climatological conditions. In low Earth orbit (LEO), the Jason-2 proton flux is better reproduced by AP8 compared to AP9, while the POES electron data are well enveloped by AE9 5th and 95th percentiles. The shape of the South Atlantic anomaly (SAA) from Jason-2 data is better captured by AP9 compared to AP8, while the peak SAA flux is better reproduced by AP8. The <1.5 MeV inner belt electrons from Magnetic Electron Ion Spectrometer (MagEIS) are well enveloped by AE9 5th and 95th percentiles, while AE8 overpredicts the measurements. In the outer radiation belt, MagEIS and Relativistic Electron and Proton Telescope (REPT) electrons closely follow the median estimate from AE9, while AP9 5th and 95th percentiles generally envelope REPT proton measurements in the inner belt and slot regions. While AE9/AP9 offer the flexibility to specify the environment with different confidence levels, the dose and trapped proton peak flux for POES and Jason-2 trajectories from the AE9/AP9 50th percentile and above are larger than the estimates from the AE8/AP8 models.

Upper limit on the inner radiation belt MeV electron intensity

Science.gov (United States)

Li, X; Selesnick, RS; Baker, DN; Jaynes, AN; Kanekal, SG; Schiller, Q; Blum, L; Fennell, J; Blake, JB

2015-01-01

No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonstrate that there exist sub-MeV electrons in the inner belt because their flux level is orders of magnitude higher than the background, while higher-energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Detailed analysis of high-quality measurements from the Relativistic Electron and Proton Telescope on board Van Allen Probes, in a geo-transfer-like orbit, provides, for the first time, quantified upper limits on MeV electron fluxes in various energy ranges in the inner belt. These upper limits are rather different from flux levels in the AE8 and AE9 models, which were developed based on older data sources. For 1.7, 2.5, and 3.3 MeV electrons, the upper limits are about 1 order of magnitude lower than predicted model fluxes. The implication of this difference is profound in that unless there are extreme solar wind conditions, which have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even though such enhancements are commonly seen in the outer belt. Key Points Quantified upper limit of MeV electrons in the inner belt Actual MeV electron intensity likely much lower than the upper limit More detailed understanding of relativistic electrons in the magnetosphere PMID:26167446

Frances Allen Wins Turing Award

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 8. Frances Allen Wins Turing Award. Priti Shankar. Article-in-a-Box Volume 12 Issue 8 August 2007 pp ... Author Affiliations. Priti Shankar1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India ...

The Foundations of Radiation Belt Research

Science.gov (United States)

Ludwig, G. H.

2008-12-01

The United States undertook the launching of an artificial Earth satellite as part of its contribution to the International Geophysical Year. The Vanguard program was established to meet that commitment, and it developed a launch vehicle, ground station network, and suite of scientific payloads, including the cosmic ray experiment proposed by James A. Van Allen. Although Vanguard eventually exceeded all of its pre-stated goals, the preemptive launches of Sputniks I and II by the Soviets in October and November 1957 spurred the U.S. into a frenzy of activity, resulting in the launches of Explorers I and III in January and March of 1958. The data from those two satellites quickly revealed the lower boundary of an unexpected region of high intensity radiation trapped in the Earth's magnetic field. The original announcement in May 1958 stated that the radiation was probably composed of either protons or electrons, and that, if electrons, it was probably bremsstrahlung formed in the satellite shell. Immediately following that announcement, approval was received for what became Explorer IV, whose announced purpose was to follow up on the new discovery. Another reason for the satellite, unmentioned at the time, was its inclusion as a component of the highly classified Argos program, a covert military program to test whether the detonation of nuclear devices at high altitude would inject measurable numbers of charged particles into durable trajectories in the Earth's magnetic field. Our team at Iowa produced the satellites under the oversight of, and with assistance by, the Army Ballistic Missile Agency in Huntsville, and with the contributions of key hardware from several other government laboratories. The project was completed in the unbelievably short period of seventy-seven days from approval to launch. Launched into a higher-inclination orbit than the earlier Explorers, Explorer IV confirmed the discovery and greatly expanded our understanding of the natural

Storm-time radiation belt electron dynamics: Repeatability in the outer radiation belt

Science.gov (United States)

Murphy, K. R.; Mann, I. R.; Rae, J.; Watt, C.; Boyd, A. J.; Turner, D. L.; Claudepierre, S. G.; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Blake, J. B.; Fennell, J. F.

2017-12-01

During intervals of enhanced solar wind driving the outer radiation belt becomes extremely dynamic leading to geomagnetic storms. During these storms the flux of energetic electrons can vary by over 4 orders of magnitude. Despite recent advances in understanding the nature of competing storm-time electron loss and acceleration processes the dynamic behavior of the outer radiation belt remains poorly understood; the outer radiation belt can exhibit either no change, an enhancement, or depletion in radiation belt electrons. Using a new analysis of the total radiation belt electron content, calculated from the Van Allen probes phase space density (PSD), we statistically analyze the time-dependent and global response of the outer radiation belt during storms. We demonstrate that by removing adiabatic effects there is a clear and repeatable sequence of events in storm-time radiation belt electron dynamics. Namely, the relativistic (μ=1000 MeV/G) and ultra-relativistic (μ=4000 MeV/G) electron populations can be separated into two phases; an initial phase dominated by loss followed by a second phase dominated by acceleration. At lower energies, the radiation belt seed population of electrons (μ=150 MeV/G) shows no evidence of loss but rather a net enhancement during storms. Further, we investigate the dependence of electron dynamics as a function of the second adiabatic invariant, K. These results demonstrate a global coherency in the dynamics of the source, relativistic and ultra-relativistic electron populations as function of the second adiabatic invariant K. This analysis demonstrates two key aspects of storm-time radiation belt electron dynamics. First, the radiation belt responds repeatably to solar wind driving during geomagnetic storms. Second, the response of the radiation belt is energy dependent, relativistic electrons behaving differently than lower energy seed electrons. These results have important implications in radiation belt research. In particular

Memory and Nostalgia in Woody Allen’s "Midnight in Paris" (Memoria y nostalgia en "Medianoche en París" de Woody Allen

Directory of Open Access Journals (Sweden)

Peter Eubanks

2015-06-01

Full Text Available Abstract: Woody Allen´s recent "Midnight in Paris" describes a Paris that has as many identities as there are observers to ascribe them. Indeed, there is no one, true Paris that everyone objectively shares; Paris, in Allen´s film, exists only in the phenomenology of the observer’s perception, a perception often marred and made unreliable by an escapist need to withdraw from the present in order to take shelter in a glorified, utopian past. Allen thus criticizes the nostalgic impulse, the "Golden-Age thinking" (as it is called in the film that forces various characters simultaneously to inhabit two worlds, that of a prelapsarian past and that of the fallen present. His protagonist´s journey back and forth between the present and the idealized Roaring Twenties is everyman´s journey, the sometimes surreal voyage between reality and imagination, between the world actually inhabited and the world artificially constructed for oneself. Yet it is when Allen´s protagonist finally discovers nostalgia within his nostalgia, a longing within his longing, that he recognizes the flawed thinking behind his almost mythologized perception of the past, reflecting everyman´s realization that the past is ultimately the expression of our present needs.Resumen: Uno de los films recientes de Woody Allen, "Midnight in Paris", describe un París que tiene tantas identidades como observadores hay a quienes atribuirlos. De hecho, no hay un París auténtico que compartan todos. París, en el film de Allen, solo existe en la fenomenología de la percepción del observador, una percepción con frecuencia dañada/arruinada y realizada poco fidedigna por una necesidad escapista a retirarse del presente para refugiarse en un pasado glorificado, utópico. Así Allen critica el impulso nostálgico, la idea del "pensamiento del siglo de oro" (tal y como viene a ser llamado en el film que obliga a que varios personajes residan en dos mundos al mismo tiempo: el de un mundo

Eerste inschatting van vrijkomen van plastics als gevolg van slijtage van Mosselzaad-Invagsystemen (MZI's)

NARCIS (Netherlands)

Hartog, E.; Brink, van den A.M.; Kamermans, P.

2014-01-01

IMARES heeft onderzoek uitgevoerd naar het ontstaan en de aanwezigheid van microplastic zwerfvuil afkomstig van mosselzaad invangsystemen (hierna MZI’s genoemd). Deze studie is onderdeel van een opdracht van het ministerie van EL&I, om de ecologische effecten van opschaling van MZI’s in de

Global solution branches for a nonlocal Allen-Cahn equation

Science.gov (United States)

Kuto, Kousuke; Mori, Tatsuki; Tsujikawa, Tohru; Yotsutani, Shoji

2018-05-01

We consider the Neumann problem of a 1D stationary Allen-Cahn equation with nonlocal term. Our previous paper [4] obtained a local branch of asymmetric solutions which bifurcates from a point on the branch of odd-symmetric solutions. This paper derives the global behavior of the branch of asymmetric solutions, and moreover, determines the set of all solutions to the nonlocal Allen-Cahn equation. Our proof is based on a level set analysis for an integral map associated with the nonlocal term.

The Brosimum allene: a structural revision.

Science.gov (United States)

Hu, Gaojie; Liu, Kai; Williams, Lawrence J

2008-12-04

Insight derived from a synthetic model, calculated (13)C NMR data, and comparison to experimental data indicate that the proposed allenic structure A, originally assigned to an isolate from Brosimum acutifolium Huber, should be revised to B, a natural product and nonallenic substance, mururin C.

Q & A with Ed Tech Leaders: Interview with Michael W. Allen

Science.gov (United States)

Shaughnessy, Michael F.

2014-01-01

Michael W. Allen, the Chairman and CEO of Allen Interactions, is an architect of interactive multimedia learning and is recognized for his many insights, inventions, and presentations. With over 50 years of experience in e-learning, both in academic and corporate settings, he is known for his role in creating Authorware and overseeing the work of…

The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) on RBSP

Czech Academy of Sciences Publication Activity Database

Kletzing, C. A.; Kurth, W. S.; Acuna, M.; MacDowall, R. J.; Torbert, R. B.; Averkamp, T.; Bodet, D.; Bounds, S. R.; Chutter, M.; Connerney, J.; Crawford, D.; Dolan, J. S.; Dvorsky, R.; Hospodarsky, G. B.; Howard, J.; Jordanova, V.; Johnson, R. A.; Kirchner, D. L.; Mokrzycki, B.; Needell, G.; Odom, J.; Mark, D.; Pfaff Jr, R.; Phillips, J. R.; Piker, C. V.; Remington, S. L.; Rowland, D.; Santolík, Ondřej; Schnurr, R.; Sheppard, D.; Smith, C. W.; Thorne, R. M.; Tyler, J.

2013-01-01

Roč. 179, 1-4 (2013), s. 127-181 ISSN 0038-6308 Grant - others: NASA (US) 921647 Institutional support: RVO:68378289 Keywords : radiation belt physics * wave measurements * magnetometer measurements * space flight instruments * RBSP * radiation belt storm probes * Van Allen probes * whistler waves * geomagnetic storms * space weather Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 5.874, year: 2013 http://link.springer.com/article/10.1007%2Fs11214-013-9993-6#page-1

Using a Neural Network Approach to Find Unusual Butterfly Pitch Angle Distribution Shapes

Science.gov (United States)

Medeiros, C.; Sibeck, D. G.; Souza, V. M. C. E. S.; Vieira, L.; Alves, L. R.; Da Silva, L. A.; Kanekal, S. G.; Baker, D. N.

2017-12-01

A special kind of neural network referred to as a Self-Organizing Map (SOM) was previously adopted to identify, in pitch angle-resolved relativistic electron flux data provided by the REPT instrument onboard the Van Allen Probes, three major types of electron pitch angle distributions (PADs), namely 90o-peaked, butterfly and flattop (Souza et al., 2016), following the classification scheme employed by Gannon et al. (2007). Previous studies show that butterfly distribution can be found in more than one shape. They usually exhibit an intense decrease near 90° pitch angles compared to the peaks usually around 30° and 150°. Sometimes unusual butterfly PAD shapes with peaks near 45° and 135° pitch angles can be observed. These could be correlated with different physical processes that govern the production and loss of energetic particles in the Van Allen radiation belt. A neural network approach allows the distinction of different kinds of butterfly PADs which were not analyzed in detail by Souza et al. (2016). This study uses SOM methodology to find these unusual butterfly PAD shape during the interval between January 1, 2014 and October 1, 2015, during which Van Allen Probes orbit covered all MLT. The spatial and temporal occurrence of these events were investigated as well as their solar wind and magnetospheric drivers.

Passive radiation shielding considerations for the proposed space elevator

Science.gov (United States)

Jorgensen, A. M.; Patamia, S. E.; Gassend, B.

2007-02-01

The Earth's natural van Allen radiation belts present a serious hazard to space travel in general, and to travel on the space elevator in particular. The average radiation level is sufficiently high that it can cause radiation sickness, and perhaps death, for humans spending more than a brief period of time in the belts without shielding. The exact dose and the level of the related hazard depends on the type or radiation, the intensity of the radiation, the length of exposure, and on any shielding introduced. For the space elevator the radiation concern is particularly critical since it passes through the most intense regions of the radiation belts. The only humans who have ever traveled through the radiation belts have been the Apollo astronauts. They received radiation doses up to approximately 1 rem over a time interval less than an hour. A vehicle climbing the space elevator travels approximately 200 times slower than the moon rockets did, which would result in an extremely high dose up to approximately 200 rem under similar conditions, in a timespan of a few days. Technological systems on the space elevator, which spend prolonged periods of time in the radiation belts, may also be affected by the high radiation levels. In this paper we will give an overview of the radiation belts in terms relevant to space elevator studies. We will then compute the expected radiation doses, and evaluate the required level of shielding. We concentrate on passive shielding using aluminum, but also look briefly at active shielding using magnetic fields. We also look at the effect of moving the space elevator anchor point and increasing the speed of the climber. Each of these mitigation mechanisms will result in a performance decrease, cost increase, and technical complications for the space elevator.

Rejuvenating Allen's Arc with the Geometric Mean.

Science.gov (United States)

Phillips, William A.

1994-01-01

Contends that, despite ongoing criticism, Allen's arc elasticity formula remains entrenched in the microeconomics principles curriculum. Reviews the evolution and continuing scrutiny of the formula. Argues that the use of the geometric mean offers pedagogical advantages over the traditional arithmetic mean approach. (CFR)

A radiation hardened digital fluxgate magnetometer for space applications

Science.gov (United States)

Miles, D. M.; Bennest, J. R.; Mann, I. R.; Millling, D. K.

2013-09-01

Space-based measurements of Earth's magnetic field are required to understand the plasma processes responsible for energising particles in the Van Allen radiation belts and influencing space weather. This paper describes a prototype fluxgate magnetometer instrument developed for the proposed Canadian Space Agency's (CSA) Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS) mission and which has applications in other space and suborbital applications. The magnetometer is designed to survive and operate in the harsh environment of Earth's radiation belts and measure low-frequency magnetic waves, the magnetic signatures of current systems, and the static background magnetic field. The new instrument offers improved science data compared to its predecessors through two key design changes: direct digitisation of the sensor and digital feedback from two cascaded pulse-width modulators combined with analog temperature compensation. These provide an increase in measurement bandwidth up to 450 Hz with the potential to extend to at least 1500 Hz. The instrument can resolve 8 pT on a 65 000 nT field with a magnetic noise of less than 10 pT/√Hz at 1 Hz. This performance is comparable with other recent digital fluxgates for space applications, most of which use some form of sigma-delta (ΣΔ) modulation for feedback and omit analog temperature compensation. The prototype instrument was successfully tested and calibrated at the Natural Resources Canada Geomagnetics Laboratory.

Crimes e pecados: Woody Allen, Hollywood e o cinema independente

OpenAIRE

Soares, Marcos; Anjos, Ana Paula B.; Fabris, Marcos

2012-01-01

In this essay we propose an analysis of the film Crimes and Misdemeanors (1989) by Woody Allen in an attempt to focus on its reflections both on the American independent movie production in the 80’s as well as on the conditions of possibility of Allen’s career. Este ensaio traz uma análise do filme Crimes e Pecados (1989) do cineasta Woody Allen que enfatiza suas reflexões tanto sobre a situação do cinema independente no final dos anos 80 nos Estados...

Versterking van de loopbaanladder van leraren : wat kunnen we leren van Singapore?

NARCIS (Netherlands)

Elffers, L.

2015-01-01

In de Lerarenagenda 2013-2020 is een aantal doelstellingen geformuleerd ten aanzien van de bevordering van de loopbaan en professionele ontwikkeling van leraren. Enerzijds wordt ingezet op het stimuleren van professionalisering van leraren na hun initiële opleiding, anderzijds op het versterken van

Effects of Drift-Shell Splitting by Chorus Waves on Radiation Belt Electrons

Science.gov (United States)

Chan, A. A.; Zheng, L.; O'Brien, T. P., III; Tu, W.; Cunningham, G.; Elkington, S. R.; Albert, J.

2015-12-01

Drift shell splitting in the radiation belts breaks all three adiabatic invariants of charged particle motion via pitch angle scattering, and produces new diffusion terms that fully populate the diffusion tensor in the Fokker-Planck equation. Based on the stochastic differential equation method, the Radbelt Electron Model (REM) simulation code allows us to solve such a fully three-dimensional Fokker-Planck equation, and to elucidate the sources and transport mechanisms behind the phase space density variations. REM has been used to perform simulations with an empirical initial phase space density followed by a seed electron injection, with a Tsyganenko 1989 magnetic field model, and with chorus wave and ULF wave diffusion models. Our simulation results show that adding drift shell splitting changes the phase space location of the source to smaller L shells, which typically reduces local electron energization (compared to neglecting drift-shell splitting effects). Simulation results with and without drift-shell splitting effects are compared with Van Allen Probe measurements.

Diagnostic accuracy of guys Hospital stroke score (allen score) in acute supratentorial thrombotic/haemorrhagic stroke

International Nuclear Information System (INIS)

Zulfiqar, A.; Toori, K. U.; Khan, S. S.; Hamza, M. I. M.; Zaman, S. U.

2006-01-01

A consecutive series of 103 patients, 58% male with mean age of 62 year (range 40-75 years), admitted with supratentorial stroke in our teaching hospital were studied. All patients had Computer Tomography scan brain done after clinical evaluation and application of Allen stroke score. Computer Tomography Scan confirmed thrombotic stroke in 55 (53%) patients and haemorrhagic stroke in 48 (47%) patients. Out of the 55 patients with definitive thrombotic stroke on Computer Tomography Scan, Allen stroke score suggested infarction in 67%, haemorrhage in 6% and remained inconclusive in 27% of cases. In 48 patients with definitive haemorrhagic stroke on Computer Tomography Scan, Allen stroke score suggested haemorrhage in 60%, infarction in 11% and remained inconclusive in 29% of cases. The overall accuracy of Allen stroke score was 66%. (author)

Duurzame inzetbaarheid van ouderen: resultaten van de eerste twee metingen van STREAM

NARCIS (Netherlands)

Heuvel, S. van den; Ybema, J.F; Leijten, F.; Wind, A. de

2013-01-01

In deze notitie richten we ons op voorspellers van duurzame inzetbaarheid, waarbij we gebruik maken van de resultaten van de eerste twee metingen van STREAM en van een interviewstudie bij deelnemers aan STREAM. Meer specifiek gaan we na hoe personen met gezondheidsproblemen toch productief kunnen

Understanding the Driver of Energetic Electron Precipitation Using Coordinated Multi-Satellite Measurements

Science.gov (United States)

Capannolo, L.; Li, W.; Ma, Q.

2017-12-01

Electron precipitation into the upper atmosphere is one of the important loss mechanisms in the Earth's inner magnetosphere. Various magnetospheric plasma waves (i.e., chorus, plasmaspheric hiss, electromagnetic ion cyclotron waves, etc.) play an important role in scattering energetic electrons into the loss cone, thus enhance ionization in the upper atmosphere and affect ring current and radiation belt dynamics. The present study evaluates conjunction events where low-earth-orbiting satellites (twin AeroCube-6) and near-equatorial satellites (twin Van Allen Probes) are located roughly along the same magnetic field line. By analyzing electron flux variation at various energies (> 35 keV) measured by AeroCube-6 and wave and electron measurements by Van Allen Probes, together with quasilinear diffusion theory and modeling, we determine the physical process of driving the observed energetic electron precipitation for the identified electron precipitation events. Moreover, the twin AeroCube-6 also helps us understand the spatiotemporal effect and constrain the coherent size of each electron precipitation event.

Bepaling van de kwaliteit van reinigingsprocessen.

NARCIS (Netherlands)

Terpstra, P.M.J.

1993-01-01

Ingegaan wordt op de operationalisering van het begrip schoon voor verschillende toepassingen. Daarna worden twee recent ontwikkelde onderzoekmethoden gepresenteerd voor de meting van respectievelijk het reinigingseffect van textiel reinigen en het reinigen van harde vloeroppervlakken en enkele met

Estudo da resistência do tendão do supra-espinal com pontos simples, duplos e Mason Allen Study on the resistance of the supraspinous tendon using simple, matress and mason allen stitches

Directory of Open Access Journals (Sweden)

Roberto Yukio Ikemoto

2010-01-01

Full Text Available OBJETIVO: O objetivo do trabalho foi comparar a resistência entre os pontos simples, duplo e Mason-Allen modificado, utilizados para o reparo do manguito rotador, e verificar se há diferença significativa que justifique a utilização do ponto do tipo Mason-Allen modificado ao invés dos pontos simples ou duplo. MÉTODO: Retiramos tendões do músculo supra-espinal de 15 cadáveres humanos frescos (30 ombros, com a média de idade de 45 anos. Os testes foram realizados na máquina universal de ensaio mecânico Kratos® 500/2000 e os resultados submetidos aos testes estatísticos de t-student, análise de variância (ANOVA, comparação múltipla de Bonferroni e calculadas as correlações de Pearson. Os testes foram realizados ao nível de significância de 5%. RESULTADOS: Não houve diferença significativa com relação à idade, ao tamanho das amostras e deslocamento do tendão. A resistência variou com média de 127,50 N com o ponto simples, 163,95 N com o duplo e com o ponto de Mason-Allen modificado esta foi de 198,45 N. CONCLUSÃO: não existe diferença da resistência no tendão quanto à falha na interface sutura - tendão comparando-se o ponto duplo com o Mason-Allen modificado e os pontos simples e duplo, porém há diferença quando comparados os pontos simples e Mason-Allen modificado.OBJECTIVE: The purpose of this study was to compare the rotator cuff tendon resistance at the interface tendon-suture using three different sorts of stitches (simple, mattress and modified Mason-Allen. METHODS: To do this, 30 rotator cuffs were totally dissected from 15 specimens, which were 45 years old on average. The tests were done using a Kratos® 500/2000 machine and the statistical analyses applied were the Student t-test, ANOVA test, Multiple Bonferroni Comparison, and Pearson's correlation coefficients; all the analyses used a significance level of 5%. RESULTS: No significant difference was observed regarding the age, sample sizes and

Verbeteren van functionele fitheid van brandweermensen

NARCIS (Netherlands)

van Orden, Claudia Y.D.

Posterpresentatie over IAG4-project 'Functional Fitness Monitor', een methodiek voor het verbeteren van functionele fitheid van brandweermensen door een combinatie van meten, presenteren van feedback en coaching. Gepresenteerd op Symposium Healthy Work: Good for Business, gehouden op 29 april 2016

Combined Global MHD and Test-Particle Simulation of a Radiation Belt Storm: Comparing Depletion, Recovery and Enhancement with in Situ Measurements

Science.gov (United States)

Sorathia, K.; Ukhorskiy, A. Y.; Merkin, V. G.; Wiltberger, M. J.; Lyon, J.; Claudepierre, S. G.; Fennell, J. F.

2017-12-01

During geomagnetic storms the intensities of radiation belt electrons exhibit dramatic variability. In the main phase electron intensities exhibit deep depletion over a broad region of the outer belt. The intensities then increase during the recovery phase, often to levels that significantly exceed their pre-storm values. In this study we analyze the depletion, recovery and enhancement of radiation belt intensities during the 2013 St. Patrick's geomagnetic storm. We simulate the dynamics of high-energy electrons using our newly-developed test-particle radiation belt model (CHIMP) based on a hybrid guiding-center/Lorentz integrator and electromagnetic fields derived from high-resolution global MHD (LFM) simulations. Our approach differs from previous work in that we use MHD flow information to identify and seed test-particles into regions of strong convection in the magnetotail. We address two science questions: 1) what are the relative roles of magnetopause losses, transport-driven atmospheric precipitation, and adiabatic cooling in the radiation belt depletion during the storm main phase? and 2) to what extent can enhanced convection/mesoscale injections account for the radiation belt buildup during the recovery phase? Our analysis is based on long-term model simulation and the comparison of our model results with electron intensity measurements from the MAGEIS experiment of the Van Allen Probes mission.

Review of radiation effects on ReRAM devices and technology

Science.gov (United States)

Gonzalez-Velo, Yago; Barnaby, Hugh J.; Kozicki, Michael N.

2017-08-01

A review of the ionizing radiation effects on resistive random access memory (ReRAM) technology and devices is presented in this article. The review focuses on vertical devices exhibiting bipolar resistance switching, devices that have already exhibited interesting properties and characteristics for memory applications and, in particular, for non-volatile memory applications. Non-volatile memories are important devices for any type of electronic and embedded system, as they are for space applications. In such applications, specific environmental issues related to the existence of cosmic rays and Van Allen radiation belts around the Earth contribute to specific failure mechanisms related to the energy deposition induced by such ionizing radiation. Such effects are important in non-volatile memory as the current leading technology, i.e. flash-based technology, is sensitive to the total ionizing dose (TID) and single-event effects. New technologies such as ReRAM, if competing with or complementing the existing non-volatile area of memories from the point of view of performance, also have to exhibit great reliability for use in radiation environments such as space. This has driven research on the radiation effects of such ReRAM technology, on both the conductive-bridge RAM as well as the valence-change memories, or OxRAM variants of the technology. Initial characterizations of ReRAM technology showed a high degree of resilience to TID, developing researchers’ interest in characterizing such resilience as well as investigating the cause of such behavior. The state of the art of such research is reviewed in this article.

Beam-Beam effects at the CMS BRIL van-der-Meer scans

CERN Document Server

CMS Collaboration

2017-01-01

The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is devoted to the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS Experiment at CERN. The project is engaged in operating and developing new detectors, compatible with the high luminosity experimental environments at the LHC. BRIL operates several detectors based on different physical principles and technologies. The detectors are calibrated using van-der-Meer scans to measure the luminosity that is a fundamental quantity of the LHC beam. In van-der-Meer scans the count rate in a detector is measured as a function of the distance between beams in the plane perpendicular to beam direction, to extract the underlying beam overlap area. The goal of the van-der-Meer scans is to obtain the calibration constant for each luminometer to be used at calibration then in physics data taking runs. The note presents the overview of beam-beam effects at the van-der-Meer scan and the corresponding corrections that sh...

Diastereoselective Synthesis of the Aminocyclitol Core of Jogyamycin via an Allene Aziridination Strategy.

Science.gov (United States)

Gerstner, Nels C; Adams, Christopher S; Grigg, R David; Tretbar, Maik; Rigoli, Jared W; Schomaker, Jennifer M

2016-01-15

Oxidative allene amination provides rapid access to densely functionalized amine-containing stereotriads through highly reactive bicyclic methyleneaziridine intermediates. This strategy has been demonstrated as a viable approach for the construction of the densely functionalized aminocyclitol core of jogyamycin, a natural product with potent antiprotozoal activity. Importantly, the flexibility of oxidative allene amination will enable the syntheses of modified aminocyclitol analogues of the jogyamycin core.

Allene oxide synthase, allene oxide cyclase and jasmonic acid levels in Lotus japonicus nodules.

Directory of Open Access Journals (Sweden)

Anna Zdyb

Full Text Available Jasmonic acid (JA, its derivatives and its precursor cis-12-oxo phytodienoic acid (OPDA form a group of phytohormones, the jasmonates, representing signal molecules involved in plant stress responses, in the defense against pathogens as well as in development. Elevated levels of JA have been shown to play a role in arbuscular mycorrhiza and in the induction of nitrogen-fixing root nodules. In this study, the gene families of two committed enzymes of the JA biosynthetic pathway, allene oxide synthase (AOS and allene oxide cyclase (AOC, were characterized in the determinate nodule-forming model legume Lotus japonicus JA levels were to be analysed in the course of nodulation. Since in all L. japonicus organs examined, JA levels increased upon mechanical disturbance and wounding, an aeroponic culture system was established to allow for a quick harvest, followed by the analysis of JA levels in whole root and shoot systems. Nodulated plants were compared with non-nodulated plants grown on nitrate or ammonium as N source, respectively, over a five week-period. JA levels turned out to be more or less stable independently of the growth conditions. However, L. japonicus nodules formed on aeroponically grown plants often showed patches of cells with reduced bacteroid density, presumably a stress symptom. Immunolocalization using a heterologous antibody showed that the vascular systems of these nodules also seemed to contain less AOC protein than those of nodules of plants grown in perlite/vermiculite. Hence, aeroponically grown L. japonicus plants are likely to be habituated to stress which could have affected JA levels.

Radiation Effects and Hardening Techniques for Spacecraft Microelectronics

Science.gov (United States)

Gambles, J. W.; Maki, G. K.

2002-01-01

The natural radiation from the Van Allen belts, solar flares, and cosmic rays found outside of the protection of the earth's atmosphere can produce deleterious effects on microelectronics used in space systems. Historically civil space agencies and the commercial satellite industry have been able to utilize components produced in special radiation hardened fabrication process foundries that were developed during the 1970s and 1980s under sponsorship of the Departments of Defense (DoD) and Energy (DoE). In the post--cold war world the DoD and DoE push to advance the rad--hard processes has waned. Today the available rad--hard components lag two-plus technology node generations behind state- of-the-art commercial technologies. As a result space craft designers face a large performance gap when trying to utilize available rad--hard components. Compounding the performance gap problems, rad--hard components are becoming increasingly harder to get. Faced with the economic pitfalls associated with low demand versus the ever increasing investment required for integrated circuit manufacturing equipment most sources of rad--hard parts have simply exited this market in recent years, leaving only two domestic US suppliers of digital rad--hard components. This paper summarizes the radiation induced mechanisms that can cause digital microelectronics to fail in space, techniques that can be applied to mitigate these failure mechanisms, and ground based testing used to validate radiation hardness/tolerance. The radiation hardening techniques can be broken down into two classes, Hardness By Process (HBP) and Hardness By Design (HBD). Fortunately many HBD techniques can be applied to commercial fabrication processes providing space craft designer with radiation tolerant Application Specific Integrated Circuits (ASICs) that can bridge the performance gap between the special HBP foundries and the commercial state-of-the-art performance.

Gold(I)-Catalysed Hydroarylation of 1,3-Disubstituted Allenes with Efficient Axial-to-Point Chirality Transfer.

Science.gov (United States)

Sutherland, Daniel R; Kinsman, Luke; Angiolini, Stuart M; Rosair, Georgina M; Lee, Ai-Lan

2018-05-11

Hydroarylation of enantioenriched 1,3-disubstituted allenes has the potential to proceed with axial-to-point chirality transfer to yield enantioenriched allylated (hetero)aryl compounds. However, the gold-catalysed intermolecular reaction was previously reported to occur with no chirality transfer owing to competing allene racemisation. Herein, we describe the development of the first intermolecular hydroarylations of allenes to proceed with efficient chirality transfer and summarise some of the key criteria for achieving high regio- and stereoselectivity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oxidative allene amination for the synthesis of azetidin-3-ones.

Science.gov (United States)

Burke, Eileen G; Schomaker, Jennifer M

2015-10-05

Regioselectivity in the aziridination of silyl-substituted homoallenic sulfamates is readily diverted to the distal double bond of the allene to yield endocyclic bicyclic methyleneaziridines with excellent stereocontrol. Subsequent reaction with electrophilic oxygen sources initiates facile rearrangement to densely functionalized, fused azetidin-3-ones in excellent d.r., effectively transferring the axial chirality of the allene to central chirality in the products. The steric nature of the silyl group dictates which of the two rings of the fused azetidin-3-one will undergo further functionalization, providing an additional element of diversity for the preparation of enantioenriched azetidine scaffolds with potential biological activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Replacement of two amino acids of 9R-dioxygenase-allene oxide synthase of Aspergillus niger inverts the chirality of the hydroperoxide and the allene oxide.

Science.gov (United States)

Sooman, Linda; Wennman, Anneli; Hamberg, Mats; Hoffmann, Inga; Oliw, Ernst H

2016-02-01

The genome of Aspergillus niger codes for a fusion protein (EHA25900), which can be aligned with ~50% sequence identity to 9S-dioxygenase (DOX)-allene oxide synthase (AOS) of Fusarium oxysporum, homologues of the Fusarium and Colletotrichum complexes and with over 62% sequence identity to homologues of Aspergilli, including (DOX)-9R-AOS of Aspergillus terreus. The aims were to characterize the enzymatic activities of EHA25900 and to identify crucial amino acids for the stereospecificity. Recombinant EHA25900 oxidized 18:2n-6 sequentially to 9R-hydroperoxy-10(E),12(Z)-octadecadienoic acid (9R-HPODE) and to a 9R(10)-allene oxide. 9S- and 9R-DOX-AOS catalyze abstraction of the pro-R hydrogen at C-11, but the direction of oxygen insertion differs. A comparison between twelve 9-DOX domains of 9S- and 9R-DOX-AOS revealed conserved amino acid differences, which could contribute to the chirality of products. The Gly616Ile replacement of 9R-DOX-AOS (A. niger) increased the biosynthesis of 9S-HPODE and the 9S(10)-allene oxide, whereas the Phe627Leu replacement led to biosynthesis of 9S-HPODE and the 9S(10)-allene oxide as main products. The double mutant (Gly616Ile, Phe627Leu) formed over 90% of the 9S stereoisomer of HPODE. 9S-HPODE was formed by antarafacial hydrogen abstraction and oxygen insertion, i.e., the original H-abstraction was retained but the product chirality was altered. We conclude that 9R-DOX-AOS can be altered to 9S-DOX-AOS by replacement of two amino acids (Gly616Ile, Phe627Leu) in the DOX domain. Copyright © 2015 Elsevier B.V. All rights reserved.

Allen's astrophysical quantities

CERN Document Server

2000-01-01

This new, fourth, edition of Allen's classic Astrophysical Quantities belongs on every astronomer's bookshelf. It has been thoroughly revised and brought up to date by a team of more than ninety internationally renowned astronomers and astrophysicists. While it follows the basic format of the original, this indispensable reference has grown to more than twice the size of the earlier editions to accommodate the great strides made in astronomy and astrophysics. It includes detailed tables of the most recent data on: - General constants and units - Atoms, molecules, and spectra - Observational astronomy at all wavelengths from radio to gamma-rays, and neutrinos - Planetary astronomy: Earth, planets and satellites, and solar system small bodies - The Sun, normal stars, and stars with special characteristics - Stellar populations - Cataclysmic and symbiotic variables, supernovae - Theoretical stellar evolution - Circumstellar and interstellar material - Star clusters, galaxies, quasars, and active galactic nuclei ...

Automatic control model of water filling system with Allen Bradley Micrologix 1400 PLC

Science.gov (United States)

Harahap, R.; Adyatma, AF; Fahmi, F.

2018-02-01

Programmable Logic Controller or PLC today plays an important role in most industrial control systems. PLC usage can be encountered in almost all fields of industry, not only in the manufacturing world but also on many other things such as elevators in office buildings, hotels hospitals, and others. PLC is an electronic control tool that operates in logic that its programming can be modified with relative ease. As with any controller in general, the PLC processes input signals to further discharge output according to the desired program. PLC usage is very broad because of its high reliability, can be reprogrammed or modified with relative ease, and very helpful in the tracking troubleshooting. One type of existing PLC is Allen Bradley PLC. Allen Bradley PLC program is commonly used in various industries. PLC Allen Bradley (AB) has several types, and one of them is the type of Micrologic 1400. In this study we design a system as a comparison with the conventional system. For that to explore the use of a PLC program which will be supported by a simulator tool, including a program to RSLogic 500, how to programming, monitoring via RSView32, and modification. It is expected to understand the application aspect of operation and programming of this specific PLC and its potential. The purpose of this research is to design water filling automation system by using Allen Bradley Micrologic 1400 type 1766-L32BXB PLC, empowering the use of Allen Bradley Micrologic 1400 PLC and to regulate the desired process to obtain efficiency and effectiveness compared with conventional system arrangement using Relay.

Verdeling van oxytetraxycline (afkomstig van versleping) in diervoeders

NARCIS (Netherlands)

Stolker, A.A.M.; Zuidema, T.; Egmond, van H.J.; Jong, de J.; Haelermans, P.J.M.; Hooglugt, J.H.

2012-01-01

De laatste jaren is er een toenemende aandacht voor de mogelijke bijdrage van therapeutisch gebruik van antibiotica in de dierhouderij op de ontwikkeling van antimicrobiële resistentie. Een additionele bron van blootstelling van landbouwhuisdieren aan antibiotica is versleping via diervoeders. In

On the dynamic London-van der Waals interaction

International Nuclear Information System (INIS)

Guzman, A.

2003-08-01

We present a theory of atomic reflection by evanescent waves in the quantized electromagnetic field vacuum that yields an analytical expression for the radiation pressure resulting from the combined effect of the evanescent field and spontaneous emission. The dynamic London-van der Waals potential between atoms and a dielectric wall is introduced as the effective interaction between the induced oscillating atomic dipole and its dipole image. Dissipative effects due to the imaginary part of the London-van der Waals potential are predicted. (author)

Space power system utilizing Fresnel lenses for solar power and also thermal energy storage

Science.gov (United States)

Turner, R. H.

1983-01-01

A solar power plant suitable for earth orbits passing through Van Allen radiation belts is described. The solar-to-electricity conversion efficiency is estimated to be around 9 percent, and the expected power-to-weight ratio is competitive with photovoltaic arrays. The system is designed to be self-contained, to be indifferent to radiation belt exposures, store energy for periods when the orbiting system is in earth shadow (so that power generation is contant), have no moving parts and no working fluids, and be robust against micrometeorite attack. No electrical batteries are required.

Selectie van Italiaanse werkwoordsvormen op basis van frequentieonderzoek

NARCIS (Netherlands)

Boer, M.G. de

2009-01-01

SAMENVATTING Dit artikel is een vroege recensie (mei 1972) van het LIF, de frequentielijst van IBM Italia uit 1971. De auteur concentreert zich op de verschillen met het project van Juilland, dat als uitgangspunt voor het LIF heeft gefungeerd. Op grond van de gegevens van het LIF is een basislijst

’n Oorsig van die bepaling van die vroeë bakterisidiese aktiwiteit van verskeie antituberkulosemiddels

Directory of Open Access Journals (Sweden)

P. R. Donald

2003-06-01

Full Text Available Die vroeë bakterisidiese aktiwiteit (VBA van ’n antituberkulosemiddel is die daaglikse afname van M tuberculosis in log10 kolonievormende eenhede per ml sputum, tydens die eerste twee dae van behandeling met die middel. Dit weerspieël die vermoë van ’n middel om aktief metaboliserende organismes in tuberkulose-longholtes te dood. Dit is ’n relatief goedkoop metode om in ’n klein groep pasiënte die antituberkulose-aktiwiteit van ’n middel, binne maande, in vivo te evalueer. Hierdie artikel som ons ondervinding op tydens sewe gepubliseerde VBA-studies, en die bronne van variasie in die prosedure word identifiseer. Die pasiënte in hierdie studies was gemiddeld 33 jaar oud, met ’n gemiddelde gewig van 50 kg en 55% het ekstensiewe of massiewe longaantasting gehad. Die hoogste VBA-waardes (0,50-0,66 is gevind in pasiënte wat isoniasied ontvang het, en die laagste waardes (0,05 en 0,09 respektiewelik was gevind in pasiënte wat die aminoglikosiede amikasien en paromomisien, albei in doserings van 15 mg/kg liggaamsgewig, ontvang het. Die algehele variasie in die VBA van 248 pasiënte was 0,0312, en die variasie toegeskryf aan die proses van sputumproduksie en -versameling was 0,0223. Dit blyk dat die verskillende aspekte van sputumproduksie en -versameling, betrokke by die lewering van ’n verteenwoordigende sputummonster, ’n groter bydrae maak tot variasie tydens die prosedure as die laboratoriumaspekte van die tegniek. Die keuring van pasiënte vir insluiting in VBA-studies, en hulle vermoë om saam te werk om ’n verteenwoordigende sputummonster te produseer, is van deurslaggewende belang in die suksesvolle voltooiing van VBA-studies.

Chloroplast DNA haplotype samenstelling van eikenopstanden (categorie "van bekende origine") van de Rassenlijst van Bomen; een aanvullende methode voor identificatie van autochtoniteit

NARCIS (Netherlands)

Buiteveld, J.; Boerwinkel, M.C.; Bovenschen, J.; Kranenborg, K.G.; Vries, de S.M.G.

2005-01-01

Tegenwoordig kan autochtoon materiaal op de Rassenlijst van Bomen geplaatst worden in de categorie `van bekende origine¿ en heeft daardoor een `officiële¿ status. Identificatie van autochtone opstanden blijft echter nog een lastige zaak. Momenteel worden autochtone opstanden geïdentificeerd met de

Neuroinformatics of the Allen Mouse Brain Connectivity Atlas.

Science.gov (United States)

Kuan, Leonard; Li, Yang; Lau, Chris; Feng, David; Bernard, Amy; Sunkin, Susan M; Zeng, Hongkui; Dang, Chinh; Hawrylycz, Michael; Ng, Lydia

2015-02-01

The Allen Mouse Brain Connectivity Atlas is a mesoscale whole brain axonal projection atlas of the C57Bl/6J mouse brain. Anatomical trajectories throughout the brain were mapped into a common 3D space using a standardized platform to generate a comprehensive and quantitative database of inter-areal and cell-type-specific projections. This connectivity atlas has several desirable features, including brain-wide coverage, validated and versatile experimental techniques, a single standardized data format, a quantifiable and integrated neuroinformatics resource, and an open-access public online database (http://connectivity.brain-map.org/). Meaningful informatics data quantification and comparison is key to effective use and interpretation of connectome data. This relies on successful definition of a high fidelity atlas template and framework, mapping precision of raw data sets into the 3D reference framework, accurate signal detection and quantitative connection strength algorithms, and effective presentation in an integrated online application. Here we describe key informatics pipeline steps in the creation of the Allen Mouse Brain Connectivity Atlas and include basic application use cases. Copyright © 2014 Elsevier Inc. All rights reserved.

A new Predictive Model for Relativistic Electrons in Outer Radiation Belt

Science.gov (United States)

Chen, Y.

2017-12-01

Relativistic electrons trapped in the Earth's outer radiation belt present a highly hazardous radiation environment for spaceborne electronics. These energetic electrons, with kinetic energies up to several megaelectron-volt (MeV), manifest a highly dynamic and event-specific nature due to the delicate interplay of competing transport, acceleration and loss processes. Therefore, developing a forecasting capability for outer belt MeV electrons has long been a critical and challenging task for the space weather community. Recently, the vital roles of electron resonance with waves (including such as chorus and electromagnetic ion cyclotron) have been widely recognized; however, it is still difficult for current diffusion radiation belt models to reproduce the behavior of MeV electrons during individual geomagnetic storms, mainly because of the large uncertainties existing in input parameters. In this work, we expanded our previous cross-energy cross-pitch-angle coherence study and developed a new predictive model for MeV electrons over a wide range of L-shells inside the outer radiation belt. This new model uses NOAA POES observations from low-Earth-orbits (LEOs) as inputs to provide high-fidelity nowcast (multiple hour prediction) and forecast (> 1 day prediction) of the energization of MeV electrons as well as the evolving MeV electron distributions afterwards during storms. Performance of the predictive model is quantified by long-term in situ data from Van Allen Probes and LANL GEO satellites. This study adds new science significance to an existing LEO space infrastructure, and provides reliable and powerful tools to the whole space community.

Biologische effectiviteit van bespuitingen: effecten van druppelgrootte en waterkwaliteit

NARCIS (Netherlands)

Zande, van de J.C.; Schans, van der D.A.; Koster, A.T.J.

2004-01-01

Deze rapportage beschrijft de invloed van watervolume, druppelgrootte en kwaliteit van het tankmengsel op de biologische effectiviteit van bespuitingen. Onder kwaliteit van het tankmengsel wordt in dit verband verstaan: temperatuur, hardheid, pH en zoutgehalte (chloor en ijzerzouten) van de

Fluorinated Amine Stereotriads via Allene Amination.

Science.gov (United States)

Liu, Lu; Gerstner, Nels C; Oxtoby, Lucas J; Guzei, Ilia A; Schomaker, Jennifer M

2017-06-16

The incorporation of fluorine into organic scaffolds often improves the bioactivity of pharmaceutically relevant compounds. C-F/C-N/C-O stereotriad motifs are prevalent in antivirals, neuraminidase inhibitors, and modulators of androgen receptors, but are challenging to install. An oxidative allene amination strategy using Selectfluor rapidly delivers triply functionalized triads of the form C-F/C-N/C-O, exhibiting good scope and diastereoselectivity for all syn products. The resulting stereotriads are readily transformed into fluorinated pyrrolidines and protected α-, β-, and γ-amino acids.

Verslag van de voorstudie: Paddenstoelen bedrijf van de toekomst

NARCIS (Netherlands)

Tuijl, van B.A.J.; Bos, A.P.; Sonnenberg, A.S.M.

2013-01-01

Het rapport ‘Paddenstoelenbedrijf van de toekomst’ is het resultaat van een uitgebreid vooronderzoek en geeft de eerste aanzet tot het creëren van gemeenschappelijke visie van de sector op een betere toekomst voor paddenstoelenkwekerijen. Het rapport doet verslag van een reeks interviews en een

An Experimental Concept for Probing Nonlinear Physics in Radiation Belts

Science.gov (United States)

Crabtree, C. E.; Ganguli, G.; Tejero, E. M.; Amatucci, B.; Siefring, C. L.

2017-12-01

A sounding rocket experiment, Space Measurement of Rocket-Released Turbulence (SMART), can be used to probe the nonlinear response to a known stimulus injected into the radiation belt. Release of high-speed neutral barium atoms (8- 10 km/s) generated by a shaped charge explosion in the ionosphere can be used as the source of free energy to seed weak turbulence in the ionosphere. The Ba atoms are photo-ionized forming a ring velocity distribution of heavy Ba+ that is known to generate lower hybrid waves. Induced nonlinear scattering will convert the lower hybrid waves into EM whistler/magnetosonic waves. The escape of the whistlers from the ionospheric region into the radiation belts has been studied and their observable signatures quantified. The novelty of the SMART experiment is to make coordinated measurement of the cause and effect of the turbulence in space plasmas and from that to deduce the role of nonlinear scattering in the radiation belts. Sounding rocket will carry a Ba release module and an instrumented daughter section that includes vector wave magnetic and electric field sensors, Langmuir probes and energetic particle detectors. The goal of these measurements is to determine the whistler and lower hybrid wave amplitudes and spectrum in the ionospheric source region and look for precipitated particles. The Ba release may occur at 600-700 km near apogee. Ground based cameras and radio diagnostics can be used to characterize the Ba and Ba+ release. The Van Allen Probes can be used to detect the propagation of the scattering-generated whistler waves and their effects in the radiation belts. By detecting whistlers and measuring their energy density in the radiation belts the SMART mission will confirm the nonlinear generation of whistlers through scattering of lower hybrid along with other nonlinear responses of the radiation belts and their connection to weak turbulence.

Samenstelling van de vluchtige olie van Origanum vulgare L. ssp. vulgare gedurende de ontwikkeling van de plant

NARCIS (Netherlands)

Maarse, Henk

1971-01-01

INLEIDING EN DOEL VAN HET ONDERZOEK Vele onderzoekers hebben de laatste jaren de vorming van de verbindingen in vluchtige olien van planten bestudeerd door het bepalen van de verandering in de samenstelling van de vluchtige olie tijdens de groei van de plant. Lemli (68) wees als eerste op de

Onderzoek naar vermindering van de bijvangst van een boomkortuig

NARCIS (Netherlands)

Marlen, van B.; Ybema, M.S.; Duijn, van J.B.

2005-01-01

In het kader van EU-project RECOVERY werden vergelijkende visserij- en selectiviteitsproeven uitgevoerd in 2002 en 2003 aan boord van MS “Tridens” aan 12 m boomkortuigen. De resultaten van een negental vistuigproeven zijn hier gegeven, gericht op het bepalen van het effect van een grote mazen kap

Wave-Particle Interactions in the Radiation Belts, Aurora,and Solar Wind: Opportunities for Lab Experiments

Science.gov (United States)

Kletzing, C.

2017-12-01

The physics of the creation, loss, and transport of radiation belt particles is intimately connected to the electric and magnetic fields which mediate these processes. A large range of field and particle interactions are involved in this physics from large-scale ring current ion and magnetic field dynamics to microscopic kinetic interactions of whistler-mode chorus waves with energetic electrons. To measure these kinds of radiation belt interactions, NASA implemented the two-satellite Van Allen Probes mission. As part of the mission, the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) investigation is an integrated set of instruments consisting of a triaxial fluxgate magnetometer (MAG) and a Waves instrument which includes a triaxial search coil magnetometer (MSC). We show a variety of waves thought to be important for wave particle interactionsin the radiation belts: low frequency ULF pulsations, EMIC waves, and whistler mode waves including upper and lower band chorus. Outside ofthe radiation belts, Alfven waves play a key role in both solar wind turbulenceand auroral particle acceleration. Several of these wave modes could benefit (or have benefitted) from laboratory studies to further refineour understanding of the detailed physics of the wave-particle interactionswhich lead to energization, pitch angle scattering, and cross-field transportWe illustrate some of the processes and compare the wave data with particle measurements to show relationships between wave activity and particle processobserved in the inner magnetosphere and heliosphere.

Die Romeinse nastrewing van onsterflikheid deur middel van memoria

Directory of Open Access Journals (Sweden)

D. R. Fouché

1985-05-01

Full Text Available Benewens die omvangryke en nasionale manifestasies van die oorspronklike onsterflikheidsgedagte in die Romeinse gemeenskap, vind ons by die Romein op kleiner skaal in groepe of indiwidueel ’n strewe na onsterflikheid langs die weg van memoria. Soos aangetoon sal word, verskil die pogings van die verskillende groepe radikaal van mekaar, hoewel die strewe en einddoel dieselfde bly, naamlik om deur die daarstelling van memoria op die gebied van woord of daad onsterflikheid te bekom.

Het planetarium van Hartog van Laun

Directory of Open Access Journals (Sweden)

Hans Hooijmaaijers

2009-12-01

Full Text Available The instrument maker Hartog van Laun devised a special table for an orrery, a lunarium and a tellurium. Van Laun made these instruments for educational purposes, but what makes his planetariums so interesting is the great variety and accuracy of demonstrations one can perform with them. In this paper I will deal with Van Laun and his instrument makers business. I will outline the design of the planetarium and some of the firm’s other instruments. Furthermore I will demonstrate that the detailed description of the planetarium made by Professor Jan Hendrik van Swinden boosted the spread of the instrument.

Theory of the Allen method and its practical bearing on pipe discharge measurement

International Nuclear Information System (INIS)

Guizerix, J.; Margrita, R.

1976-01-01

The Allen method for measurement of pipe discharge is based on a general relationship between discharge, instrument section volume and the first moment of the residence time distribution. An original demonstration of this standard chemical engineering relationship is given. The Allen method thus offers a very wide practical application scope. Requirements are limited to knowing the volume of the instrument section and the residence time distribution; the shape of the instrument section is immaterial. The information can be obtained for example by means of a system correlating the instrument section input and output signals [fr

Commentary on Sowcik and Allen: Getting Down to Business

Science.gov (United States)

Murphy, Susan Elaine

2013-01-01

Sowcik and Allen's paper, "Getting Down to Business: A Look at Leadership Education in Business Schools," identifies a number of compelling issues in improving leadership education in business schools and provides a thorough overview of how these efforts could benefit from the considerations present in the National Leadership Educators…

‘n Kritiese bespreking van roskam se seining van apartheid as grondslag van die Suid-afrikaanse samelewing

Directory of Open Access Journals (Sweden)

N. van Loggerenberg

1963-03-01

Full Text Available Segregasie is al deur vele ondersoekers histories tot ’n tradisie uit die stigtingsjaar 1652 met die aankoms van Jan van Riebeeck herlei. Roskam sion dit egter as 'n beleid wat veel later aanvaar is. Hy sien dit as beleid wat bepaalde groepe van die bevolking as 'n politieke eenheid, kragtens ’n sosiale hiërargie, van mekaar wil afskei, isoleer. Dit is vir  hom duidelik dat die politieke eenheid van Ordinansie 50 van 1828 nooit werklikheid geword het nie, en die tradisie van blanke heerskappy pas vir liom as heleid beter in die huidige situasic as segregasie. Roskam is dan van oordeel dat ..white supremacy” daarom die juiste en omskrywende betekenis van segregasie is.

Detectie van ziektesymptomen met behulp van fluorescentiebeelden

NARCIS (Netherlands)

Loon, van P.C.C.

2004-01-01

Rapport over de positie van de biologische paddestoelenteelt op intersectoraal en (inter)-regionaal niveau. Het overzicht in tabel- en schemavorm van de stromen grondstoffen en producten verduidelijkt de intersectorale positie van de champignonteelt. Dit kan een aanzet zijn bij het signaleren en

Een revisie van de taxonomie van gifkikkers

NARCIS (Netherlands)

Poelman, E.H.

2007-01-01

Recent kwam het lang verwachte ruim tweehonderdvijftig pagina`s tellende manuscript uit met daarin een revisie van de taxonomie van gifkikkers. De auteurs onder leiding van Taran Grant stellen een nieuwe taxonomie voor, die de familie Dendrobatidae met haar tien algemener geaccepteerde genera

Three-dimensional data assimilation and reanalysis of radiation belt electrons: Observations over two solar cycles, and operational forecasting.

Science.gov (United States)

Kellerman, A. C.; Shprits, Y.; Kondrashov, D. A.; Podladchikova, T.; Drozdov, A.; Subbotin, D.; Makarevich, R. A.; Donovan, E.; Nagai, T.

2015-12-01

Understanding of the dynamics in Earth's radiation belts is critical to accurate modeling and forecasting of space weather conditions, both which are important for design, and protection of our space-borne assets. In the current study, we utilize the Versatile Electron Radiation Belt (VERB) code, multi-spacecraft measurements, and a split-operator Kalman filter to recontructe the global state of the radiation belt system in the CRRES era and the current era. The reanalysis has revealed a never before seen 4-belt structure in the radiation belts during the March 1991 superstorm, and highlights several important aspects in regards to the the competition between the source, acceleration, loss, and transport of particles. In addition to the above, performing reanalysis in adiabatic coordinates relies on specification of the Earth's magnetic field, and associated observational, and model errors. We determine the observational errors for the Kalman filter directly from cross-spacecraft phase-space density (PSD) conjunctions, and obtain the error in VERB by comparison with reanalysis over a long time period. Specification of errors associated with several magnetic field models provides an important insight into the applicability of such models for radiation belt research. The comparison of CRRES area reanalysis with Van Allen Probe era reanalysis allows us to perform a global comparison of the dynamics of the radiation belts during different parts of the solar cycle and during different solar cycles. The data assimilative model is presently used to perform operational forecasts of the radiation belts (http://rbm.epss.ucla.edu/realtime-forecast/).

De toekomst van flex : een onderzoek van tno naar flexstrategieën van Nederlandse bedrijven

NARCIS (Netherlands)

Verbiest, S.E.; Goudswaard, A.; Wijk, E.B. van

2014-01-01

In 2020 zal het personeelsbestand van organisaties voor 30% uit flexkrachten bestaan. Op dit moment is dat 25%. Dit blijkt uit een onderzoek van TNO onder 900 ondernemingen in opdracht van de ABU (Algemene Bond Uitzendondernemingen). Het blijkt dat met name organisaties die al gebruikmaken van

De trek van kruiden van volgroeid wortelmateriaal : handleiding van A tot Z in beknopte vorm

NARCIS (Netherlands)

Wijk, van C.A.P.

2005-01-01

Deze teelthandleiding richt zich op de trek van vooral dragon, krulpeterselie, rucola en munt, uitgaande van wortelmateriaal dat in de vollegrond wordt geteeld. Deze forcering richt zich zowel op aanbod van kruiden in potjes als de meermalige oogst van het gesneden product in een kas of een

Numerieke simulatie van de blastbelasting op vlucht MH17 van Malaysia Airlines als gevolg van de detonatie van een gevechtslading (U)

NARCIS (Netherlands)

2015-01-01

De Onderzoeksraad voor Veiligheid (OVV) onderzoekt de crash van vlucht MH17 van Malaysia Airlines die plaatsvond op donderdag 17 juli 2014 in de regio Donetsk (Oekraïne). De OVV wil een duidelijk beeld geven van de oorzaak van de crash. Een mogelijke oorzaak is fatale schade aan het vliegtuig als

The effectiveness of the Allen Carr smoking cessation training in companies tested in a quasi-experimental design

NARCIS (Netherlands)

Dijkstra, Arie; Zuidema, Rixt; Vos, Diederick; van Kalken, Marike

2014-01-01

Background: The Allen Carr training (ACt) is a popular one-session smoking cessation group training that is provided by licensed organizations that have the permission to use the Allen Carr method. However, few data are available on the effectiveness of the training. Methods: In a quasi-experimental

Filosofiese tendense in die wordinggeskiedenis van ons verstaan van die fisiese natuur

Directory of Open Access Journals (Sweden)

D. F. M. Strauss

2006-09-01

Full Text Available Die ontstaan van ’n lang tradisie van natuurwetenskaplike denke is in antieke Griekeland te vind – die bakermat van die Westerse beskawing en die bron van geartikuleerde rasionele besinning. Die vroegste fases van die Griekse kultuur het reeds geboorte geskenk aan ’n teoretiese nadenke oor die heelal. Die Pythagoreërs is veral bekend vir hul klem op die verklaringskrag van getalsverhoudinge. In hul tese dat “alles getal is” het hulle egter slegs rasionale getalle (breuke erken en gevolglik uiteindelik vasgeloop in die ontdekking van irrasionale getalle wat tot die geometrisering van die Griekse wiskunde gelei het en tegelyk die bedding gevorm het van waaruit ’n magtige tradisie van ruimte-metafisika gegroei het wat die hele middeleeuse tydperk omspan het. Die vermeende statiese syn is in die mees ekstreme geval – die skool van Parmenides en die argumente van Zeno teen veelheid en beweging – tot in die uiteindelike antinomiese konsekwensies daarvan deurdink. Dit was egter eers die vroeg-moderne tyd – die voorgangers en nakomelinge van Galilei – wat naas getal en ruimte ’n waardering ontwikkel het vir die verklaringskrag van beweging (vergelyk die klassieke meganistiese wêreldbeeld van die heelal as ’n meganisme van stofdeeltjies in beweging. Maar ook hierdie meganistiese reduksie (waardeur alle fisiese verskynsels herlei is tot die beweging van al of niegelade massapunte sou uiteindelik misluk omdat dit nie van die onomkeerbaarheid van fisiese prosesse rekenskap kon gee nie. Gevolglik beliggaam eers die fisika van die 20ste eeu ’n erkenning van die deurslaggewend-stempelende rol van energie-werking (dus van die fisiese aspek in die aard van stoflike dinge en prosesse. Die artikel word afgesluit met ’n vlugtige verduideliking van die implikasies van die voorafgaande argumentasie vir ’n benadering van die misterie van die bestaan van materie.

Beoordeling van het gedrag van bestrijdingsmiddelen in de verzadigde zone van de bodem

NARCIS (Netherlands)

Linden AMA van der; Beek CGEM van; Boesten JJTI; Leistra M; Meinardi CR; Puijker LM; LBG

1994-01-01

In het MeerJarenPlan-Gewasbescherming van 1991 is de mogelijkheid gegeven om door middel van onderzoek in de verzadigde fase van de bodem aan te tonen dat bestrijdingsmiddelen, die kunnen uitspoelen naar de verzadigde zone, alsnog voor toelating in aanmerking kunnen komen als de

Onderzoek naar de effecten van snoezelen op het gedrag van demente verpleeghuisbewoners en de werkbeleving van verzorgenden.

NARCIS (Netherlands)

Weert, J. van; Peter, J.; Dulmen, S. van; Ribbe, M.; Bensing, J.

2004-01-01

Het effect van snoezelen in de 24-uurszorg op de stemming en het gedrag van demente ouderen is nooit eerder onderzocht. Ook is in geen van de eerdere studies het effect onderzocht van snoezelen op de werkbeleving van verzorgenden. Uit onderzoek is bekend dat in verpleeghuizen waar geen

Beoordeling van het gedrag van bestrijdingsmiddelen in de verzadigde zone van de bodem

NARCIS (Netherlands)

Linden, van der A.M.A.; Beek, van C.G.E.M.; Boesten, J.J.T.I.; Leistra, M.; Meinardi, C.R.; Puijker, L.M.

1999-01-01

In het MeerJarenPlan-Gewasbescherming van 1991 is de mogelijkheid gegeven om door middel van onderzoek in de verzadigde fase van de bodem aan te tonen dat bestrijdingsmiddelen, die kunnen uitspoelen naar de verzadigde zone, alsnog voor toelating in aanmerking kunnen komen als de omzettingssnelheid

[A study on Horace N. Allen's medicine and recognition of Korean body].

Science.gov (United States)

Lee, Young Ah

2011-12-31

Je Jung Won was the first modern-style Government hospital built by the Korean King Ko-Jong in April 1885, and it was the medical missionary Horace Newton Allen(1858~1932) who made one of the greatest contributions to the establishment of the hospital. Allen was an American missionary. He graduated from Ohio Wesleyan University with a degree in theology in 1881, and completed one-yearcourse at Miami Medical College. In Korea and America he worked as a physician, a missionary, an American diplomatic minister to Korea and a Korean minister's secretary to America. While acting as a mediator between Korea and America, he knew and recorded the domestic and foreign situation of Korea during Gaehwagi(the civilized and enlightened age). Thus to study him is to understand Korea's Gaehwagi as well as to research American medical missionaries. During his stay in Korea(1884~1905), Allen steadily wrote diaries and letters about Korean politics, diplomacy, society, culture, and medicine. Thus his public/private record through diaries and letters(the quantity of these materials amounts to several thousands) supplements the Korean early modern era's historical record. However, until now these materials have received little scholarly attention from researchers except for a few historians of missionary work between Korea and America, or of Korean modern medicine. I intended to use these materials to suggest a new perspective on the study of Korean Gaehwagi. Allen, along with John W. Heron, who came to Seoul on June 21st 1885, treated about 10,460 Korean patients in the first year of the opening of JeJungWon. They made "the first annual report of the Korean Government Hospital". This report explained how Allen and Heron regarded and treated Korean patients. Allen's diaries, letters and other writings offer a realistic view of how the western people actually recognized the Korean people at that time. As a western doctor, Allen had an ambivalent attitude toward Korean medical concepts

Miks meil on kogu aeg kiire? / David Allen ; interv. Endrik Randoja

Index Scriptorium Estoniae

Allen, David

2006-01-01

Produktiivsuse ekspert vastab küsimustele ettevõetud tegevuste tulemuslikumalt lõpule viimise kohta. Lisa: Aja paremaks kasutamiseks pakub David Allen lisaks veel kolm tõhusat ja lihtsasti rakendatavat põhimõtet

Isotope separation by photodissociation of Van der Wall's molecules

International Nuclear Information System (INIS)

Lee, Y.T.

1977-01-01

A method of separating isotopes based on the dissociation of a Van der Waal's complex is described. A beam of molecules of a Van der Waal's complex containing, as one partner of the complex, a molecular species in which an element is present in a plurality of isotopes is subjected to radiation from a source tuned to a frequency which will selectively excite vibrational motion by a vibrational transition or through electronic transition of those complexed molecules of the molecular species which contain a desired isotope. Since the Van der Waal's binding energy is much smaller than the excitational energy of vibrational motion, the thus excited Van der Waal's complex dissociate into molecular components enriched in the desired isotope. The recoil velocity associated with vibrational to translational and rotational relaxation will send the separated molecules away from the beam whereupon the product enriched in the desired isotope can be separated from the constituents of the beam

Bepaling van de optredende temperaturen bij tunnelcompostering van geitenmest

NARCIS (Netherlands)

Melse, R.W.; Sauvage, de G.J.; Roest, H.I.J.

2010-01-01

Het doel van het project is om inzicht te krijgen in de composteerbaarheid van geitenmest en het hiermee samenhangende temperatuursverloop . Bepaald dient te worden welke temperaturen tijdens het composteren van geitenmest worden bereikt om op basis daarvan een inschatting te kunnen maken van de

Kleinschalige raffinage van bietenblad : eerste verkenning van de moglijkheden

NARCIS (Netherlands)

Wolf, de P.L.; Visser, de C.L.M.; Keijsers, E.R.P.; Meesters, K.P.H.; Heesakkers, J.W.M.; Aerts, M.

2013-01-01

Doelstelling van de eerste fase van het onderzoek was ‘het verkennen van kleinschalige keten(s) voor de raffinage van bietenblad’, met aandacht voor de technologische en economische haalbaarheid. Deze verkenning vormt de basis voor de volgende fase, waarin kansrijke opties verder worden uitgewerkt

Presence of the vancomycin resistance gene cluster vanC1, vanXYc, and vanT in Enterococcus casseliflavus.

Science.gov (United States)

Hölzel, Christina; Bauer, Johann; Stegherr, Eva-Maria; Schwaiger, Karin

2014-04-01

The three chromosomally located clustered genes vanC1, vanXYc, and vanT confer intrinsic resistance to vancomycin and are used for species identification of Enterococcus gallinarum. In this study, 28 strains belonging to the E. gallinarum/casseliflavus group isolated from cloacal swabs from laying hens were screened for the presence of vanC1. As confirmed by species-specific multiplex PCR, 11 vanC1-positive strains were identified as E. gallinarum. Surprisingly, one yellow pigmented strain, verified as E. casseliflavus by species-specific multiplex PCR, was also vanC1 positive; vanXYc and vanT were additionally detectable in this strain. To our knowledge, this is the first report of vanC1, vanXYc, and vanT in E. casseliflavus. The minimum inhibitory concentration of vancomycin was 4 mg/L. Real-time reverse transcription-PCR revealed that none of the clustered genes was expressed in this strain. Even if the genes seem not to be active, there is a certain risk that they will be transferred to other bacteria where they might be functionally expressed. Therefore, it may be advisable to expand the search for vanC1, vanXYc, and vanT from E. gallinarum to other (enterococcal) species. This study confirms that enterococci live up to their name as being reservoir bacteria and should therefore always be closely monitored.

Die gebruik van parallelplaatreologie vir die bepaling van die intrinsieke viskositeit van poli-etileentereftalaat

Directory of Open Access Journals (Sweden)

O. C. Vorster

2005-09-01

Full Text Available Die bepaling van die intrinsieke viskositeit van poli-etileentereftalaat word bemoeilik deur die feit dat daar tans slegs twee metodes in gebruik is. In die eerste metode word die bepaling deur middel van oplossingsviskometrie gedoen, maar die toksisiteit van die oplosmiddel, asook die tydperk wat dit neem om die bepaling te doen, is ’n probleem. Die tweede metode word beperk deur die kompleksiteit en beskikbaarheid van die apparatuur in Suid-Afrika. In hierdie studie word ’n alternatiewe metode, gebaseer op parallelplaatreologie, voorgestel wat albei hierdie probleme oorkom en die resultate sodoende verkry, word vergelyk met dié wat met bestaande metodes verkry is.

Die identifisering van maatstawwe vir die navorsingsprestasie van akademici

Directory of Open Access Journals (Sweden)

H. A. Labuschagne

1990-06-01

Full Text Available Identification of criteria for academic research performance. At South African universities, the achievement of objectives is usually measured in terms of so-called "process criteria" (e.g. pass rates, instead of performance criteria which reflect the quality of academic personnel. Stimulated by the need to identify valid indices of research performance, as a component of academic performance, this study investigated the dimensionality of several criteria, identified from empirical and literature studies. It was found that various valid criteria could be represented by six constructs, viz.: the stature of the researcher as scientist; scientific contributions; enhancement of own profession; community development; participation in research projects; and giving advice to persons or institutions outside the university. Opsomming By Suid-Afrikaanse universiteite word doelwitbereiking gewoonlik aan die hand van sogenaamde "prosesmaat-stawwe" (bv. slaagsyfers in plaas van prestasiemaatstawwe wat die gehalte van akademiese personeel weerspieel, gemeet. Na aanleiding van 'n behoefte aan die identifisering van geldige rigtingwysers vir navorsingsprestasie as 'n komponent van akademiese prestasie, is daar ondersoek ingestel na die dimensionaliteit van verskillende maatstawwe wat vooraf deur middel van empiriese- en literatuurstudies geidentifiseer is. Daar is gevind dat verskeie geldige maatstawwe deur ses konstrukte verteenwoordig word, te wete: die statuur van die navorser as wetenskaplike, wetenskaplike bydraes, uitbouing van eie professie, gemeenskapsontwikkeling, deelname aan navorsingsprojekte en advieslewering aan persone of instellings buite die Universiteit.

Arthroscopic modified Mason-Allen technique for large U- or L-shaped rotator cuff tears.

Science.gov (United States)

Jung, Sung-Weon; Kim, Dong-Hee; Kang, Seung-Hoon; Lee, Ji-Heon

2017-07-01

While a conventional single- or double-row repair technique could be applied for repair of C-shaped tears, a different surgical strategy should be considered for repair of U- or L-shaped tears because they typically have complex patterns with anterior, posterior, or both mobile leaves. This study was performed to examine the outcomes of the modified Mason-Allen technique for footprint restoration in the treatment of large U- or L-shaped rotator cuff tears. Thirty-two patients who underwent an arthroscopic modified Mason-Allen technique for large U- or L-shaped rotator cuff tears between January 2012 and December 2013 were included in this study. Margin convergence was first performed to reduce the tear gap and tension, and then, an arthroscopic Mason-Allen technique was performed to restore the rotator cuff footprint in a side-to-end repair fashion. All patients were evaluated preoperatively and for a minimum of 2 years of follow-up with a visual analog scale (VAS) for pain, Constant score, and ultrasonography. There was significant improvement in all VAS and Constant scores compared with the preoperative values (P rotator cuff in our data. Overall satisfactory results were achieved in most patients, with the exception of those with severe fatty degeneration. An arthroscopic modified Mason-Allen technique could be an effective and reliable alternative for patients with large U- or L-shaped rotator cuff tears. Case Series, Therapeutic Level IV.

Effects of Electromagnetic Perturbations on Particles Trapped in the Radiation Belts

Energy Technology Data Exchange (ETDEWEB)

Dungey, J. W. [Imperial College of Science and Technology, London (United Kingdom)

1965-06-15

Since the radiation belts were discovered by Van Allen in 1958, observations of trapped particles have rapidly built up a large body of information. Knowledge of the neutral atmosphere as well as the ionosphere shows that for energetic particles the probable time before colliding with another particle of any kind may be extremely long. Then the only feature known to affect the motion of the particle is the electromagnetic field and, conversely, over a long time even weak electromagnetic disturbances can be important. Consequently, electromagnetic disturbances should be important in determining the form of the radiation belts, and it will be seen that certain features encourage an interpretation of this kind. The physics of the radiation belts may be regarded as a part of plasma physics, namely the realm in which collisions are negligible. This needs qualifying in that there is a boundary layer (the ionosphere) where collisions are important, and this is analogous to laboratory plasma containment devices. The energy range of trapped particles is wide, but includes the energy range required for fusion reactors. The mean free time in the radiation belts is extreme, but the neglect of collisions yields a great simplification in theoretical work, and an understanding of collision-free plasmas is expected to be useful. Observations in space have great advantages. The quantity measured by a particle-detector sensitive to a limited range of energy and with a limited cone of acceptance is the velocity distribution function, which is fundamental in theoretical work. Local electric and magnetic measurements are also made with very little disturbance by the spacecraft. The disadvantage is that simultaneous measurements cannot be made at many different points.

Invloed van minerale olie op de bestrijding van Phytophthora infestans in pootaardappelen

NARCIS (Netherlands)

Spits, H.G.; Bus, C.B.

2003-01-01

De invloed van toevoeging van olie aan een fungicide op de werking van het fungicide is afhankelijk van het gebruikte fungicide. Gezamenlijk spuiten van olie en Aviso DF, Curzate M en mogelijk ook Acrobat, verhoogt de curatieve werking van deze fungiciden. Gezamenlijk spuiten van olie en Aviso DF,

B. J. van der Merwe . Pentateugtradisies in die prediking van ...

African Journals Online (AJOL)

B. J. van der Merwe . Pentateugtradisies in die prediking van Deuterojesaja. Proefschrift ter verkrijging van de graad van Doctor in de Godgeleerdheid aan de Rijkuniversiteit te Groningen. Uitg. J. B. Wolters, Groningen, Djakarta. 1955. 280 bls.

n Oorsig van die huidige stand van navorsing oor die

African Journals Online (AJOL)

Test

7 Jun 2011 ... Die eerste maal wat dit as deel van die teks van 1 Johannes aangehaal word, is in die. 4de eeu in 'n Latynse teks, Liber Apologeticus (hf 4). Eers aan die einde van die 16de eeu is dit in 'n amptelike Katolieke uitgawe van die Vulgaat ingesluit. Die doel van die Johannesbriewe. Waarom is die Briewe ...

Design and Development of a Configurable Fault-Tolerant Processor (CFTP) for Space Applications

Science.gov (United States)

2003-06-01

Slot Region BIRA/ IASB Figure 5. Van Allen Belts (After Ref. [20].) 17 The trapped particles in the Van Allen Belts include electrons trapped in...the most sig- nificant role in the failure of electronic equipment in orbit. There exists a wide range of these circuit-crippling events, including...such, the goals of the CFTP project are the most rigorous constraints applied on the design process, and are what will ensure its future role as an

Detectie van Meloidogyne spp. in grondmonsters - een vergelijking van twee technieken

NARCIS (Netherlands)

Veenhuizen, P.T.M.; Schoemakers, N.; Vos, J.; Versteegen, F.; Landeweert, R.; Karssen, G.

2007-01-01

Hier volgen de samenvattingen van de bijeenkomst van 20 maart 2007 van de KNPV-werkgroep Meloidogyne. 1) Kwantitatieve multiplexdetectie van aaltjes; 2). Meloidogyne chitwoodi en M. fallax: vergelijking visuele beoordeling en Taqman-PCR aan pootaardappelen; 3) Detectie van Meloidogyne spp. in

Stroming en samenstelling van de sprengen en het grondwater van de Veluwe in 1996; een vergelijking met de toestand van 1986

NARCIS (Netherlands)

Meinardi CR; LBG

1999-01-01

Monsters water uit sprengen en grondwater van de Veluwe zijn onderzocht op concentraties van hoofdcomponenten en van microcomponenten (bepalingen door NITG). Onderzoek is gedaan ter bepaling van verblijftijden in de bodem van grondwater en van het water in sprengen. De intrekgebieden van de

A. VAN SELMS. LUKAS SE SEGSMAN VIR DIE GESKIEDENIS VAN ...

African Journals Online (AJOL)

Test

oordele aan die eerste drie hoofstukke van sy Evangelie, het Lukas onder „van ..... Simon te onderskei van Simon Petrus, hoef ons nie erns te maak nie. .... op hulle beurt vereenselwig met Mosa van Jos. .... i&) Lukas der Arzt. Leipzig, 1906.

Van de Graaff Irradiation of Materials

Energy Technology Data Exchange (ETDEWEB)

Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-10-01

Through irradiations using our 3 MeV Van de Graaf accelerator, Argonne is testing the radiation stability of components of equipment that are being used to dispense molybdenum solutions for use as feeds to ^99mTc generators and in the ^99mTc generators themselves. Components have been irradiated by both a direct electron beam and photons generated from a tungsten convertor.

Digitale incunabelen : Over het belang van het archiveren van websites

NARCIS (Netherlands)

Voerman, Gerrit; Keyzer, Andreas; den Hollander, Franciscus

'Het geheugen van Nederland verpulvert'. Zo luidde de noodkreet van ruim twintig grote bibliotheken in het voorjaar van 1998. In een advertentie in enkele landelijke dagbladen vroegen deze bibliotheken om honderden miljoenen guldens voor het restaureren, fotograferen en digitaliseren van boeken en

Digitale incunabelen : Over het belang van het archiveren van websites

NARCIS (Netherlands)

Voerman, Gerrit; Keyzer, Andreas; den Hollander, Franciscus

2000-01-01

'Het geheugen van Nederland verpulvert'. Zo luidde de noodkreet van ruim twintig grote bibliotheken in het voorjaar van 1998. In een advertentie in enkele landelijke dagbladen vroegen deze bibliotheken om honderden miljoenen guldens voor het restaureren, fotograferen en digitaliseren van boeken en

Inclusie door interprofessionele samenwerking. : Resultaten van de proeftuinen van PACT.

NARCIS (Netherlands)

Doornenbal, Jeannette; Fukkink, Ruben; van Yperen, Tom; Balledux, Mariëlle; Spoelstra, Jolanda; Verseveld, Marloes

2017-01-01

Deze rapportage gaat over de resultaten van de PACT-proeftuinen waaraan in opdracht van Het Kinderopvangfonds van 2015 tot 2017 is gewerkt. PACT-proeftuinen zijn innovatieve praktijken waarin door middel van interprofessionele samenwerking tussen de kinderopvang, het basisonderwijs en de zorg wordt

Die opleiding van bedryfsielkundiges aan die universiteit van Fort Hare

Directory of Open Access Journals (Sweden)

W. Botha

1977-11-01

Full Text Available Die Departement Bedryfsielkunde aan die Universiteit van Fort Hare is 'n relatiewe jong departement en het eers in 1965 tot stand gekom. Voor hierdie datum is Bedryfsielkunde as 'n kort kursus deur die departement van suiwer Sielkunde aangebied en een van die destydse dosente, Dr. W. Backer, het die inisiatief geneem om 'n selfstandige departement van Bedryfsielkunde in die Fakulteit van Ekonomiese Wetenskappe op die been te bring.

Het effect van creatief schrijven op het lezen van korte verhalen

NARCIS (Netherlands)

Janssen, T.; van den Bergh, H.

2010-01-01

Schrijven en lezen zijn complementaire vaardigheden, niet alleen bij referentiële teksten, maar ook bij fictionele. Janssen en Van den Bergh doen verslag van een onderzoek naar de invloed van creatief schrijven op het lezen van verhalen. Als leerlingen, voorafgaand aan het lezen van een verhaal, een

Databank van de lithografische opbouw en morfologische ontwikkeling van de uiterwaarden van de Midden-Waal

NARCIS (Netherlands)

Hebinck, K.A.

2008-01-01

In de uiterwaarden zijn de komende decennia veel ingrepen gepland. Een goede kennis van de sedimentatiedynamiek en morfologische ontwikkeling van de uiterwaarden is daarbij een vereiste. Daartoe is een digitale databank (op CD bij dit rapport) opgesteld van de opbouw en geomorfologische ontwikkeling

Fluorescentievingerafdruk van Aardappel, Melganzenvoet en Mais : Eerste resultaten van plantonderscheid met behulp van fluorescentie

NARCIS (Netherlands)

Groot, T.T.; Nieuwenhuizen, A.T.

2012-01-01

Als het spectrum van één “soort” (gewas) vergeleken wordt met de rest (onkruid) neemt het onderscheid van het “gewas” af tot 70%. Het lijkt dus nodig ook de spectra van alle soorten onkruid in het veld te kennen om een goed onderscheid mogelijk te maken. De doelstelling voor deze metingen is een

Proeven van tekstkritiek. Een onderzoek betreffende de tekstgeschiedenis van de Renout van Montalbaen en de Perceval

NARCIS (Netherlands)

Hogenhout-Mulder, Maaike Janna

1984-01-01

In dit proefschrift wordt een poging gedaan de tekstgeschiedenis te achterhalen van twee Middelnederlandse tekstfragmenten: een gedeelte uit de RENOUT VAN MONTALBAEN en een gedeelte uit de PERCEVAL. ... Zie: Twee tekstfragmenten als object van onderzoek

Invoering van algemene vaardigheden: mogelijkheden van een vakoverstijgende aanpak

NARCIS (Netherlands)

Leenders, F.J.

2003-01-01

Centrale vraag: Het onderzoek richtte zich op de implementatie van vakoverstijgend vaardighedenonderwijs in de Tweede Fase van het voortgezet onderwijs. Belangrijkste conclusies: De brochure bevat onder meer een beschrijving van vijf scholen waar op verschillende wijze vaardighedenonderwijs

Resultaten van het Rijkswaterstaat JAMP 2009 monitoringsprogramma van bot (Platichthys flesus L.). Biologische gegevens van bot en milieukritische stoffen in bot

OpenAIRE

Hoek-van Nieuwenhuizen, van, M.; Barneveld, van, E.

2010-01-01

De in dit rapport beschreven werkzaamheden zijn in 2009 door IMARES uitgevoerd op basis van een opdracht van Rijkswaterstaat in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De opdracht hield in het verkrijgen van biologische gegevens van bot (visziekten). De benodigde monsters bot werden verzameld door IMARES. Tevens werd materiaal van bot verzameld voor chemisch onderzoek en geanalyseerd.

Optique moderne et post-moderne dans la composition d'images transculturelles dans trois films de Woody Allen

Directory of Open Access Journals (Sweden)

Nadia Fuchs

2010-12-01

Full Text Available Avec le personnage récurrent juif new-yorkais névrosé plus ou moins autobiographique, les films de Woody Allen ont créé, volontairement ou pas, leur propre mythologie et un genre à part entière composé de codes que le spectateur décrypte instantanément. Pourtant, Woody Allen est surtout un cinéaste post-moderne, analysant et déconstruisant les simulacres de son époque. Il est ainsi un passeur d'images retraçant l'histoire des arts modernes des XXe et XXIe siècles et de leurs stratégies énonciatives et réceptives.With the recurrent persona of the neurotic and more or less autobiographical Jewish New Yorker, Woody Allen's films have created, willingly or not, their own mythology and a specific genre made up of codes readily accessible to the spectator. However, Woody Allen is more than anything else a postmodern filmmaker who analyses and deconstructs the simulacra of his time. He is thus a conveyor of images which retrace the history of modern art of the XXth and XXIth centuries, and of their strategies of enunciation and reception.

Resultaten van het Rijkswaterstaat JAMP 2008 monitoringsprogramma van bot (Platichthys flesus L.). Biologische gegevens van bot en milieukritische stoffen in bot

NARCIS (Netherlands)

Hoek-van Nieuwenhuizen, van M.; Barneveld, van E.

2009-01-01

De in dit rapport beschreven werkzaamheden zijn door Wageningen IMARES uitgevoerd op basis van een opdracht van Rijkswaterstaat in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De opdracht hield in het verkrijgen van biologische gegevens van bot. De benodigde monsters

Afbouw van het Wsw-bestand: actualisatie op basis van Wsw-gegevens ultimo 2013

NARCIS (Netherlands)

Berden, C.; Tempelman, C.

2014-01-01

In opdracht van het ministerie van Sociale Zaken en Werkgelegenheid heeft SEO Economisch Onderzoek onderzoek gedaan naar de verdeling van het Participatiebudget over gemeenten. Een onderdeel van dit onderzoek vormde het voorspellen van de afbouw van het huidige zittend bestand in de Wsw op basis van

Resultaten van het Rijkswaterstaat JAMP 2009 monitoringsprogramma van bot (Platichthys flesus L.). Biologische gegevens van bot en milieukritische stoffen in bot

NARCIS (Netherlands)

Hoek-van Nieuwenhuizen, van M.; Barneveld, van E.

2010-01-01

De in dit rapport beschreven werkzaamheden zijn in 2009 door IMARES uitgevoerd op basis van een opdracht van Rijkswaterstaat in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De opdracht hield in het verkrijgen van biologische gegevens van bot (visziekten). De benodigde

Die beskerming van biologiese diversiteit deur gebruik te maak van die gevoeligheidsvariasie van spesies vir toksiese stowwe

Directory of Open Access Journals (Sweden)

A. J. Reinecke

2003-09-01

Full Text Available Pogings om algemeen geldende standaarde of maatstawwe vir omgewingskwaliteit op te stel vir die beskerming van Suid-Afrika se ryk biodiversiteit word bemoeilik deur die feit dat spesies baie kan verskil  ten opsigte van hulle gevoeligheid vir toksiese stowwe. Daar kan dus nie sonder meer vanaf een spesie na ’n ander geëkstrapoleer word nie. Deur egter juis gebruik te maak van hierdie variasie in gevoeligheid van spesies, kan die assessering van die risiko wat besoedelingstowwe vir organismes inhou wel op ’n meer wetenskaplike grondslag bedryf word. Hierdie konsep gaan uit van die standpunt dat indien kwaliteitskriteriums opgestel word wat die sensitiefste spesies beskerm, alle ander spesies outomaties beskerm word. Hierdie bydrae fokus op die gebruik van sensitiwiteitsverspreidings van spesies as metode en kyk oorsigtelik en krities na die aard en toepassings van die ekstrapolasiemodelle wat op hierdie verspreidings gebaseer is. Die moontlike aanwending daarvan en die argumente ten gunste daarvan en daarteen word bespreek. Die gevolgtrekking word gemaak dat spesie-sensitiwiteitsverspreidings wel nuttige aanwending kan vind, maar dat  gegewens oor die gevoeligheid van plaaslike spesies  baie skaars is. Hoewel dit reeds bruikbaar is, kan die algemene aanwending daarvan  in Suid-Afrika aansienlik uitgebrei word indien meer navorsing gedoen word om betroubare toksisiteitsgegewens vir verskillende spesies in te win, sodat die model meer verfyn kan word. Daarvoor moet gestandaardiseerde toksisiteitstoetse vir plaaslike spesies eers ontwikkel word.

Gevolgen van hydrocephalus

NARCIS (Netherlands)

Tromp, Cornelis Nicolaas

1984-01-01

Hydrocephalus is een aandoening van het centrale zenuwstelsel die de clinicus vrij lang voor grote problemen ten aanzien van de behandeling heeft qesteld. Door de toepassing van de ventriculo-atriale shunttechniek zijn de behandelingsmogelijkheden van hydrocephalus sterk verbeterd. Deze studie

Activity Regulation by Heteromerization of Arabidopsis Allene Oxide Cyclase Family Members

Czech Academy of Sciences Publication Activity Database

Otto, M.; Naumann, Ch.; Brandt, W.; Wasternack, Claus; Hause, B.

2016-01-01

Roč. 5, č. 1 (2016), č. článku 3. ISSN 2223-7747 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Activity regulation * Arabidopsis allene oxide cyclase isoforms * Heteromerization Subject RIV: EB - Genetics ; Molecular Biology

Overzicht van de onderzoekresultaten van kroketten, bitterballen en frikandellen van 1986

NARCIS (Netherlands)

Cazemier, G.; Veen, van der N.G.

1987-01-01

In 1986 werden in opdracht van de AID 54 monsters frikandellen en 237 monsters kroketten en bitterballen door het RIKILT onderzocht op de eisen, zoals die zijn vastgelegd in de Kwaliteitsverordening Kroketten, Bitterballen en Frika(n)dellen. In dit verslag zijn de analyseresultaten van deze monsters

Spatial and temporal variability of chorus and hiss

Science.gov (United States)

Santolik, O.; Hospodarsky, G. B.; Kurth, W. S.; Kletzing, C.

2017-12-01

Whistler-mode electromagnetic waves, especially natural emissions of chorus and hiss, have been shown to influence the dynamics of the Van Allen radiation belts via quasi-linear or nonlinear wave particle interactions, transferring energy between different electron populations. Average intensities of chorus and hiss emissions have been found to increase with increasing levels of geomagnetic activity but their stochastic variations in individual spacecraft measurements are usually larger these large-scale temporal effects. To separate temporal and spatial variations of wave characteristics, measurements need to be simultaneously carried out in different locations by identical and/or well calibrated instrumentation. We use two-point survey measurements of the Waves instruments of the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) onboard two Van Allen Probes to asses spatial and temporal variability of chorus and hiss. We take advantage of a systematic analysis of this large data set which has been collected during 2012-2017 over a range of separation vectors of the two spacecraft. We specifically address the question whether similar variations occur at different places at the same time. Our results indicate that power variations are dominated by separations in MLT at scales larger than 0.5h.

ʼn Kritiese evaluering van wetgewing wat die gesondheid van ...

African Journals Online (AJOL)

User

gereguleer wat "basiese watervoorsiening" omskryf as "die voorgeskrewe minimum standaard van watervoorsieningsdienste wat nodig is vir die betroubare voorsiening van ʼn toereikende hoeveelheid en gehalte water aan huishoudings, met inbegrip van informele huishoudings, om lewe en persoonlike higiëne te steun".

Cooperative Metal–Ligand Catalyzed Intramolecular Hydroamination and Hydroalkoxylation of Allenes Using a Stable Iron Catalyst

KAUST Repository

El-Sepelgy, Osama

2018-01-18

A new iron-catalyzed chemoselective intramolecular hydroamination and hydroalkoxylation of the readily available α-allenic amines and alcohols to valuable unsaturated 5-membered heterocycles, 2,3-dihydropyrrole and 2,3-dihydrofuran, is reported. Effective selectivity control is achieved by a metal–ligand cooperative activation of the substrates. The mild reaction conditions and the use of low amounts of an air and moisture stable iron catalyst allow for the hydrofunctionalization of a wide range of allenes bearing different functional groups in good yields in the absence of base or any sensitive additives.

Cooperative Metal–Ligand Catalyzed Intramolecular Hydroamination and Hydroalkoxylation of Allenes Using a Stable Iron Catalyst

KAUST Repository

El-Sepelgy, Osama; Brzozowska, Aleksandra; Sklyaruk, Jan; Jang, Yoon Kyung; Zubar, Viktoriia; Rueping, Magnus

2018-01-01

A new iron-catalyzed chemoselective intramolecular hydroamination and hydroalkoxylation of the readily available α-allenic amines and alcohols to valuable unsaturated 5-membered heterocycles, 2,3-dihydropyrrole and 2,3-dihydrofuran, is reported. Effective selectivity control is achieved by a metal–ligand cooperative activation of the substrates. The mild reaction conditions and the use of low amounts of an air and moisture stable iron catalyst allow for the hydrofunctionalization of a wide range of allenes bearing different functional groups in good yields in the absence of base or any sensitive additives.

Karakterisering van het Etimologiewoordeboek van Afrikaans (EWA

Directory of Open Access Journals (Sweden)

Fons Moerdijk

2011-10-01

Full Text Available

Samenvatting: Zesendertig jaar na Afrikaanse etimologieë van Boshoff en Nienaber verscheener in 2003 een nieuw etymologisch woordenboek van het Afrikaans: het Etimologiewoordeboek vanAfrikaans (EWA. Tussen die twee woordenboeken bestaat een wezenlijk verschil. Het werk vanBoshoff en Nienaber is vrijwel alleen toegankelijk voor specialisten en niet specifiek bedoeld vooreen breed publiek. EWA is juist allereerst bestemd voor de leek die zich interesseert voor de oorsprongen de geschiedenis van de eigen taal. Daarnaast biedt het ook de etymoloog en historischtaalkundige een hoop gegevens en inspiratie voor nader onderzoek. Als etymologisch woordenboekbezit EWA een aantal bijzondere, eigen kenmerken. De selectie van de woorden is bepaalddoor het beoogde gebruikerspubliek. Als gevolg daarvan bevat EWA verscheidene typen woordendie in traditionele etymologische woordenboeken doorgaans veronachtzaamd worden, zoals afleidingen,samenstellingen, neologismen en gemeenzame spreektaalwoorden. De artikelstructuurwordt gekenmerkt door een hoge graad van uniformiteit en consistentie. Het accent ligt op dezogenaamde etymologia proxima, de etymologie waarbij men één stap teruggaat en de meestdirecte herkomst van het woord biedt. Voorts is speciale aandacht besteed aan polysemie: nietalleen de herkomst van de dominante betekenis van een woord wordt gegeven, maar ook die vanzijn eventuele andere betekenis(sen. Benoemingsmotieven komen ook veelvuldig aan bod. In eeneventuele tweede druk zouden opvallende verschillen in vorm of betekenis altijd verklaard of inieder geval besproken moeten worden. Dat blijft nu nogal eens achterwege. Ook zou voorafgaandaan zo'n volgende editie meer onderzoek naar woordhistorisch materiaal uit primaire bronnenvoor met name de 17de–19de eeuw verricht moeten worden. Het zou mooi zijn als deze eersteuitgave van EWA de aanleiding tot een dergelijk onderzoek zou vormen.

Sleutelwoorden: BENOEMINGSMOTIEF, ETYMOLOGIA PROXIMA

Kwantificatie van de invloed van regen op de verkeerdoorstroming

NARCIS (Netherlands)

Calvert, S.C.; Van Stralen, W.; Molin, E.J.E.

2013-01-01

Kwantificatie van de invloed van regen op de verkeerdoorstroming Het is bekend dat het weer invloed heeft op het verkeer op snelwegen, en in het bijzonder filevorming. Op de eerste plaats wordt de wegcapaciteit tijdelijk beïnvloed door een verandering in rijgedrag van bestuurders. Ten tweede

Hovering and forward flight energetics in Anna's and Allen's hummingbirds.

Science.gov (United States)

Clark, Christopher James; Dudley, Robert

2010-01-01

Aerodynamic theory predicts that the mechanical costs of flight are lowest at intermediate flight speeds; metabolic costs of flight should trend similarly if muscle efficiency is constant. We measured metabolic rates for nine Anna's hummingbirds (Calypte anna) and two male Allen's hummingbirds (Selasphorus sasin) feeding during flight from a free-standing mask over a range of airspeeds. Ten of 11 birds exhibited higher metabolic costs during hovering than during flight at intermediate airspeeds, whereas one individual exhibited comparable costs at hovering and during forward flight up to speeds of approximately 7 m s(-1). Flight costs of all hummingbirds increased at higher airspeeds. Relative to Anna's hummingbirds, Allen's hummingbirds exhibited deeper minima in the power curve, possibly due to higher wing loadings and greater associated costs of induced drag. Although feeding at a mask in an airstream may reduce body drag and, thus, the contributions of parasite power to overall metabolic expenditure, these results suggest that hummingbird power curves are characterized by energetic minima at intermediate speeds relative to hovering costs.

Prozaci asemel GTD ehk getting things done / David Allen ; interv. Endrik Randoja

Index Scriptorium Estoniae

Allen, David

2007-01-01

Konsultant ja koolitaja David Allen oma aja- ja enesejuhtimise meetodist GTD - getting things done. Vt. samas: Väikesed nipid, et tõhusam olla; Milles seisneb Alleni meetod; Kuidas ma oma ülesannet täitsin - logiraamat

Resultaten van het RWS-RIKZ JAMP 2005 monitoringsprogramma van bot (Platichthys flesus L.) : Biologische gegevens van bot en milieukritische stoofen in bot

NARCIS (Netherlands)

Kotterman, M.J.J.

2006-01-01

In opdracht van RWS-RIKZ werden door het RIVO werkzaamheden uitgevoerd in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De opdracht hield in het verkrijgen van biologische gegevens van bot. De werkzaamheden bestonden uit het verzamelen van monsters bot waarvan

'Uytnemende Schilder van Antwerpen' : Joos van Cleve: atelier, productie en werkmethoden

NARCIS (Netherlands)

Leeflang, Micha

2007-01-01

Joos van Cleve (ca. 1480-1541) was een van de meest invloedrijke Antwerpse schilders in de eerste helft van dezestiende eeuw. Hij kreeg belangrijke opdrachten voor portretten en altaarstukken van onder anderen de Franse koning Frans I. Micha Leeflang onderzocht met name de materieel-technische

Resultaten van het RWS-RIKZ JAMP 2006 monitoringsprogramma van bot (Platichthys flesus L.). Biologische gegevens van bot en milieukritische stoffen in bot

OpenAIRE

Kotterman, M.J.J.; Barneveld, van, E.

2007-01-01

De in dit rapport beschreven werkzaamheden werden door IMARES uitgevoerd op basis van een opdracht van Rijkswaterstaat- Rijksinstituut voor Kust en Zee (RIKZ) in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De opdracht hield in het verkrijgen van biologische gegevens van bot. De benodigde monsters bot werden verzameld door IMARES. Tevens werd materiaal van bot verzameld voor chemisch onderzoek en geanalyseerd.

Toepassing van de basisvrachtbenadering op fosfaat van compost; advies

NARCIS (Netherlands)

Ehlert, P.A.I.

2005-01-01

Bij het vormgeven van het stelsel van gebruiksnormen is een maatschappelijke discussie ontstaan over de aanvoer van fosfaat met grond in compost en zwarte grond. Deze deskstudie gaat in op vragen die hierbij gesteld zijn. Het aandeel grond in compost en zwarte grond en de hoeveelheid fosfaat daarin

"Die beiteltjie" van N.P. van Wyk Louw en

African Journals Online (AJOL)

Tom

belangrike kenmerk van die postmodernisme is, wil ek dit nie tot abso- lute kenmerk verhef nie. Een van die .... oorgang vanaf 'n epistemologiese ingesteldheid tot 'n ontologiese ingesteldheid demonstreer en ..... the neglected and a whole range of phenomena which have been denied a history. Die formulering van die ...

Invioed van de zuurtegraad van varkensurine op de ammoniakemissie

NARCIS (Netherlands)

Eizing, A.; Aarnink, A.J.A.

1996-01-01

Dit rapport beschrijft het effect van een lagere urine-pH op de ammoniakemissie in een varkensstal. Het onderzoek is uitgevoerd in een modelopstelling met de zogenaamde stalsimulator, waarbij de invloed van de urine-pH op de ammoniakemissie werd onderzocht. Hiervoor werd de urine van vleesvarkens op

Ontwerp van een interventie om de groenteconsumptie van jongeren te verhogen

NARCIS (Netherlands)

Gilissen, L.J.W.J.; Meer, van der I.M.; Reinders, M.J.; Sluis, van der A.A.; Woltering, E.J.

2011-01-01

In dit rapport zullen verschillende mogelijke strategieën besproken worden die ingezet kunnen worden om de consumptie van groenten door jongeren te verhogen. De centrale vragen van dit onderzoek zijn: 1) Hoe kunnen groenten in het eetpatroon van jongeren een vaste plek van voldoende omvang krijgen?

Reductie van het kiemgetal van bacteriën op champignons : literatuuroverzicht

NARCIS (Netherlands)

Baars, J.J.P.

2006-01-01

Dit rapport bevat een literatuurstudie waarin een overzicht wordt gegeven van de beschikbare literatuur m.b.t. hoogte van het kiemgetal van bacteriën op champignons en de grondstoffen voor de champignonteelt, aanwezigheid van pathogene bacteriën op champignons die in de retail worden aangeboden en

Het handwerk van de theorie in de praktijk van het Sociaal Werk

Directory of Open Access Journals (Sweden)

Hans Oostrik

2010-06-01

Sociaal werk is een narratieve praktijk. Vanuit een sociaal-constructivistische invalshoek, reflecteert de auteur in dit artikel op de vraag hoe vanuit deze narratieve praktijk tot theoretische handelingsmodellen kan worden gekomen. Drie elementen spelen daarbij een rol, welke door de auteur worden behandeld. Ten eerste zijn dat de vaardigheden van de professional, die bijdragen aan conceptualisering, zoals daar zijn: het signaleren van kwesties, het analyseren en vormen van begrippen en het ontwerpen van conceptuele modellen. Ten tweede kunnen theoretische modellen in de praktijk van het sociaal werk gebruikt worden als instrumenten om die praktijk als het ware te theoretiseren of reflectief te maken. De praktijk wordt met behulp van modellen zoals scenario’s en stappenplannen, verbeterd en verder ontwikkeld. Ten derde bestaat het handwerk van de theorie in het innemen van een theoretische houding of praktische verstandigheid waardoor sociaal werkers beter om kunnen gaan met de complexiteit van hun praktijk.

Effecten van wintergewassen op verliezen en benutting van stikstof bij de teelt van snijmaos; verslag van onderzoek op ROC Aver-Heino tussen voorjaar 1991 en najaar 1994

NARCIS (Netherlands)

Dijk, van W.; Schröder, J.J.; Holte, ten L.; Groot, de W.J.M.

1995-01-01

Tussen 1988 en 1994 is onderzoek verricht naar de effecten van wintergewassen (winterrogge en onderzaai van gras) op de verliezen en benutting van stikstof bij continuteelt van snijmaos op zandgrond. Gemiddeld over de gehele onderzoeksperiode nam zowel rogge als gras 30-40 kg/ha op in de

Gebruik van TaqMan PCR voor het kwantificeren van Fusarium spp. en Microdochium nivale in gewassen en gewasresten van tarwe.

NARCIS (Netherlands)

Köhl, J.; Haas, de B.H.; Kastelein, P.; Burgers, S.L.G.E.; Waalwijk, C.

2005-01-01

Infecties van tarwe door toxigene Fusarium spp. kunnen leiden tot contaminatie van graan met diverse mycotoxines. Voorkoming van mycotoxinebesmetting is uit oogpunt van voedselveiligheid, diergezondheid, maar ook bedrijfseconomisch, vereist. Voor vier Fusariumsoorten is een kwantitatieve detectie

Van die Gasredakteur

African Journals Online (AJOL)

cherish and teach.'1. Die Fakulteit Geneeskunde van die Universiteit van die Oranje-Vrystaat het pragtig gegroei ge- durende die eerste 21 jaar van sy bestaan. Die entoesiasme, doelgerigtheid, harde werk en inisia- tiewe van 'n groot aantal persone was hiervoor verantwoordelik. 'If we see a bit more clearly than they, it is ...

De werking van de hydro- en acetylverbindingen van kinidine en kinine op het hart van Rana esculenta

NARCIS (Netherlands)

Sibie, Johan Dirk

1942-01-01

In hoofdstuk I werd een inleiding gegeven betreffende de geschiedenis van de kina en van het begin der kinacultuur op Java, de chemie der kinaälkaloïden en enkele aspecten der pharmacologische werking van de kinaderivaten. ... Zie: Samenvatting

Introductie van de Chevon : een zoektocht naar de afzet van geitenvlees

NARCIS (Netherlands)

Eleveld, I.; Louis Bolk,

2008-01-01

Het afmesten en afzetten van lammeren op een biologisch bedrijf is geen gemakkelijke weg. Aan de smaak van het vlees zal het niet liggen. De chevon, lammeren met een leeftijd van 5 tot 7 maand, geven vlees met karakter: een vleugje geit! De onbekendheid van het vlees vereist een zorgvuldige

De auteursrechtelijke aansprakelijkheid van intermediairs, het kabelpiratenarrest revisited in de tijd van Internet

NARCIS (Netherlands)

Dommering, E.J.; Verkade, D.W.F.; Visser, D.J.G.

1998-01-01

Het kabelpiratenarrest vestigde de auteursrechtelijke aansprakelijkheid van de kabelexploitant voor het verspreiden van gestolen films die clandestien na de uitzendingen van de reguliere omroepen werden uitgezonden met gebruikmaking van de centrale antenne-inrichting van KTA. Zouden wij de

De mislukte missie van mr. Maarten van Naarden als luitenant-stadhouder van Stad en Lande 1541-1557

Directory of Open Access Journals (Sweden)

F. Postma

2005-01-01

Full Text Available Maarten van Naarden’s failed mission  as lieutenant-stadholder of the province of Groningen, 1541-1557In November 1557, Maarten van Naarden resigned from his post as lieutenant-stadholder of the province of Groningen and left the province after staying there for sixteen years. Van Naarden’s resignation was preceded by a number of conflicts with the Groningen town council and the States of the province. However, these conflicts were neither confined to Van Naarden nor the province of Groningen. They had also taken place  in other provinces in the Northeast of the Netherlands. What makes Van Naarden’s clash with the Groningen provincial authorities in the 1550s so important is that it clarifies the principles that were at stake. These principles were less apparent in the conflicts between the representatives of the central government in Friesland, Overijssel and Gelderland. It was a struggle in which Van Naarden tried, as his opponents rightly saw it, to introduce the ‘constitution’ of Utrecht in the town and county of Groningen. In Utrecht, which had been annexed by Charles V in 1528, the autonomy of the province had been reduced to next to nothing. The only authority still resting with the States was the surveillance of the provincial dikes and waterways. All their other areas of authority had been taken over by the provincial court of which Van Naarden had been president between 1537 and 1541. To avoid the same thing happening to them, Van Naarden was ordered to appear before the Groningen States assembly in January 1556. At this meeting, the weakness of his position became crystal clear. None of the members took his side. Because the government lacked the means to keep Van Naarden in office, his withdrawal from Groningen was inevitable. What we see behind the story of Van Naarden more clearly than in the conflicts in the neighbouring provinces is the outline of the absolute state that Van Naarden’s superiors had in mind for the

DIE ROL VAN DIE TAALWETENSKAP IN DIE ONTWIKKELING VAN ...

African Journals Online (AJOL)

aanslag op die sogenaamde "Intentional Fallacy", heelwat verder. n. Mens sou hier eintlik ook op die invloed van Lacan se toepassing van. De Sacs sure op Freud moet wys, en op Macherey se Theory of Literary. Production. Barthes is naamlik besig om repressie teen te werk, en die teks as produksieproses in stede van ...

'n Voordrag van Adrianus van Seims oor hermeneutiek | Boshoff ...

African Journals Online (AJOL)

A lecture on hermeneutics by Adrianus van Seims This article is the content of a lecture on hermeneutics given by A van Seims. After a few opening words on the introduction to the lecture and its content, the presentation is reproduced in its entirety. Van Seims considers that hermeneutics is concerned not only with ...

"Krakende kaken"; psychiatrische beschouwingen over het syndroom van het pijnlijke, slecht functionerende kaakgewricht (Arthrosis deformans van het kaakgewricht of het syndroom van Costen)

NARCIS (Netherlands)

Schuler, Jacques

1966-01-01

Naar aanleiding van klinische indrukken en mede op grond van literatuurgegevens werd een psychiatrisch onderzoek verricht naar het aandeel van psychogene factoren bij het tot stand komen van kaakgewrichtsklachten. Het klachtencomplex dat van stoornissen in de functie van het kaakgewricht het gevolg

Voedselverspilling, waarden van voedsel in de keten : de mogelijke rol van het groene onderwijs bij het oplossen van een maatschappelijke opgave

OpenAIRE

Waarts, Y.R.; Onwezen, M.C.; Wiersinga, R.C.; Eppink, M.M.; Thoden van Velzen, E.U.; Timmermans, A.J.M.

2009-01-01

Het doel van deze verkenning is om op basis van literatuur en interviews met belangrijkste stakeholders een visie te formuleren over de wijze waarop het groene onderwijs een bijdrage kan leveren aan het verminderen van voedselverliezen binnen alle schakels van de keten inclusief de consument, en aan de nuttige toepassing van reststromen.

die impak van metodologie op die verstaan van die nuwe testament

African Journals Online (AJOL)

voorbeeld eers een maal deur die bril van die vorm- en redaksiekritiek na die Evangelies gekyk het, dink jy vir altyd anders oor hulle tot- standkoming. Inderdaad, nuwe metodes lei tot nuwe perspektiewe! Dit is dan ook waar die fokus van hierdie artikel val: die impak van metodologie op die verstaan van die Nuwe ...

Effectieve bestrijding van varroa

NARCIS (Netherlands)

Cornelissen, B.; Blacquiere, T.; Steen, van der J.J.M.

2010-01-01

De varroa mijtziekte (Varroa destructor) is de belangrijkste bedreiging van de Europese honingbij. Wintersterfte van honingbijen is in de meeste gevallen toe te schrijven aan deze ziekte. Deze brochure van de WUR biedt informatie over de biologie van varroa, de effecten van varroa op honingbijen en

Prediking aan die hand van die metafoor van fiksieskryf

African Journals Online (AJOL)

p1243322

HTS 64(3) 2008 siening van die self en waarheid. In die pre-moderne paradigma kan die dominante metafoor verstaan word aan die hand van 'n spieël wat die lig uit 'n transendente oorsprong weerkaats, terwyl die moderne paradigma uitgedruk word met die metafoor van 'n lamp wat 'n eie, oorspronklike lig binne die self.

’n Etiek van liefde: Die etiese perspektiewe van die Heidelbergse Kategismus

Directory of Open Access Journals (Sweden)

Koos Vorster

2013-06-01

Full Text Available Hierdie artikel behandel die etiese perspektiewe van die Heidelbergse Kategismus – een van die prominente belydenisskrifte in die gereformeerde tradisie. Die etiese relevansie is ingebed in die konfessie se verklaring van die tien gebooie. Die artikel verduidelik dat die etiek van die Heidelbergse Kategismus ten diepste ’n karakteretiek is en dat dit gelowiges oproep tot ’n etiek van liefde. Hierdie liefde sluit in liefde vir die verbondsgemeenskap, die bediening van die Woord, die heiligheid van God en die waardigheid van mense, die gemeenskap van die gelowiges, gesag, die lewe, die huwelik, privaatbesit en arbeid asook waarheid en geregtigheid. As gevolg van die sinekdogeekarakter van die wet is hierdie etiek van liefde vandag baie relevant. This article deals with the ethical relevance of one of the prominent confessions in the reformed tradition, namely the Heidelberg Cathechism. The ethical relevance lies in the confession’s elucidation of the ten commandments and its application to moral conduct. The article explains that the ethics of the Heidelberg Catechism is essentially a virtue ethics calling for an ethics of love. This love should include love for the covenantal communion, ministry of the Word, the holiness of God and the dignity of people, the communion of the saints, authority, life, marriage, private property and labour, and truth and justice. Due to the synecdochical character of the ten commandments this ethics of love is highy relevant in the present times.

Optimaliseren van een biovergister

NARCIS (Netherlands)

van der Bij, Joost; Rademaker, Mark; Visser, Klaas; de Vries, Herman

2014-01-01

Dit rapport beschrijft onderzoek van conversie van biomassa in een Swill-gasser geplaatst bij het Van der Valk restaurant in Cuijk. De Swill-gasser is een biomassa vergister voor restaurant afval. Het onderzoek heeft zich gericht op het optimaliseren van de data acquisitie en op het bepalen van de

Kenmerkend van hierdie afdeling is die tema van ouderdom wat in ...

African Journals Online (AJOL)

8 Apr 2016 ... Kenmerkend van hierdie afdeling is die tema van ouderdom wat in menige van die stories voorkom. Hier is dit die onvermydelike aftakelingsproses van die liggaam (en verstand) wat 'n beduidende invloed op die skrywer het. In verhale soos “Wat 'n lieflike geraas”, “Die ou met die overall”, “Lofredes en ...

Bepaling van enkele neurotransmitters, monoaminen, en metabolieten, met behulp van Continuous Flowapparatuur

NARCIS (Netherlands)

Eigeman L; Schonewille F; Borst M; van der Laan JW

1986-01-01

Bij het onderzoek in de psychofarmacologie kan kennis van de effecten van stoffen op de omzettingssnelheid van neurotransmitters een belangrijk aspect zijn. Met de huidige psychofarmaca lijken vooral de klassieke neurotransmitters zoals de monoaminen, noradrenaline, dopamine en serotonine van

Kansen voor conflictbemiddeling : Verslag van een onderzoek naar de toepassingsmogelijkheden van conflictbemiddeling

NARCIS (Netherlands)

Geveke, Henk; Plant, Ernelies; Thieme, Marianneke; Verberk, Marielle

1998-01-01

In opdracht van het Platform ADR, een klankbordgroep en denktank op het gebied van alternatieve geschilbeslechting, is onderzoek verricht naar de toepasbaarheid van een specifieke vorm van Alternative Dispute Resolution (ADR): conflictbemiddeling (mediation). De onderzoeksopdracht was als volgt: het

Allen Brain Atlas-Driven Visualizations: a web-based gene expression energy visualization tool.

Science.gov (United States)

Zaldivar, Andrew; Krichmar, Jeffrey L

2014-01-01

The Allen Brain Atlas-Driven Visualizations (ABADV) is a publicly accessible web-based tool created to retrieve and visualize expression energy data from the Allen Brain Atlas (ABA) across multiple genes and brain structures. Though the ABA offers their own search engine and software for researchers to view their growing collection of online public data sets, including extensive gene expression and neuroanatomical data from human and mouse brain, many of their tools limit the amount of genes and brain structures researchers can view at once. To complement their work, ABADV generates multiple pie charts, bar charts and heat maps of expression energy values for any given set of genes and brain structures. Such a suite of free and easy-to-understand visualizations allows for easy comparison of gene expression across multiple brain areas. In addition, each visualization links back to the ABA so researchers may view a summary of the experimental detail. ABADV is currently supported on modern web browsers and is compatible with expression energy data from the Allen Mouse Brain Atlas in situ hybridization data. By creating this web application, researchers can immediately obtain and survey numerous amounts of expression energy data from the ABA, which they can then use to supplement their work or perform meta-analysis. In the future, we hope to enable ABADV across multiple data resources.

Allen Brain Atlas-Driven Visualizations: A Web-Based Gene Expression Energy Visualization Tool

Directory of Open Access Journals (Sweden)

Andrew eZaldivar

2014-05-01

Full Text Available The Allen Brain Atlas-Driven Visualizations (ABADV is a publicly accessible web-based tool created to retrieve and visualize expression energy data from the Allen Brain Atlas (ABA across multiple genes and brain structures. Though the ABA offers their own search engine and software for researchers to view their growing collection of online public data sets, including extensive gene expression and neuroanatomical data from human and mouse brain, many of their tools limit the amount of genes and brain structures researchers can view at once. To complement their work, ABADV generates multiple pie charts, bar charts and heat maps of expression energy values for any given set of genes and brain structures. Such a suite of free and easy-to-understand visualizations allows for easy comparison of gene expression across multiple brain areas. In addition, each visualization links back to the ABA so researchers may view a summary of the experimental detail. ABADV is currently supported on modern web browsers and is compatible with expression energy data from the Allen Mouse Brain Atlas in situ hybridization data. By creating this web application, researchers can immediately obtain and survey numerous amounts of expression energy data from the ABA, which they can then use to supplement their work or perform meta-analysis. In the future, we hope to enable ABADV across multiple data resources.

De mislukte missie van mr. Maarten van Naarden als luitenant-stadhouder van Stad en Lande 1541-1557

NARCIS (Netherlands)

Postma, F.

2005-01-01

Maarten van Naarden’s failed mission as lieutenant-stadholder of the province of Groningen, 1541-1557 In November 1557, Maarten van Naarden resigned from his post as lieutenant-stadholder of the province of Groningen and left the province after staying there for sixteen years. Van Naarden’s

Ondersoek na ’n teoretiese onderskraging van boekkuns: Die toepassing van Bakhtin se dialogisme en heteroglossia op geselekteerde voorbeelde van kunstenaarsboeke

Directory of Open Access Journals (Sweden)

David Paton

2012-11-01

Full Text Available Onlangse navorsingsprojekte en konferensies oor boekkuns het gereageer op Johanna Drucker se oproep in 2005 dat noodsaaklike navorsingswerk gedoen moet word om ’n deegliker teoretiese basis vir die terrein van boekkunsproduksie te vestig. Die deelname van kunstenaars en ander praktisyns van boekkuns veroorsaak dat gesprekke en besprekings noodwendig en voorspelbaar neig na die praktyk en weg van die teorie. In die lig van die behoefte aan die bepaling van ’n toepaslike visie waarvolgens die kunsboek meer eksplisiet, ook teoreties, ondersoek kan word, ondersoek hierdie artikel Stéphane Mallarmé en Marcel Broodthaers se Un coup de dés publikasies, Buzz Spector se simplifiserende Marcel Broodthaers, Ulises Carrion se For fans and scholars alike, en Helen Douglas en Telfer Stokes se Real fiction. Hierdie spesifieke voorbeelde, en hulle onderlinge verbande en dialoog met mekaar, word ondersoek vanuit die perspektief van die Russiese filosoof en literêre teoretikus Mikhail Bakhtin se werk oor dialogisme en heteroglossia (‘ander-tongigheid’. Hierdie begrippe demonstreer die dialogiese, multivokale en veeltongige wisselwerking tussen en binne historiese werke as kultuuruitings. Deur die analise toon ek aan dat hierde begrippe toepaslike en funksionele raamwerke uitmaak vir die analise van spesifieke aspekte wat die teenwoordigheid van kunstenaarsboeke aankondig in die wêreld: selfbewustheid en omvattende diskoers wat wederkerend toepaslik is. Ek stel voor dat Bakthin se idees oor dialogisme en heteroglossie gebruik word as die teoretiese begronding van die kunstenaarsboek as ’n dinamiese visuele taal wat in ’n netwerk van ander tekste staan en deel is van die proses van die eindelose herbeskrywing van die wêreld.

Resultaten van het RWS-RIKZ JAMP 2006 monitoringsprogramma van bot (Platichthys flesus L.). Biologische gegevens van bot en milieukritische stoffen in bot

NARCIS (Netherlands)

Kotterman, M.J.J.; Barneveld, van E.

2007-01-01

De in dit rapport beschreven werkzaamheden werden door IMARES uitgevoerd op basis van een opdracht van Rijkswaterstaat- Rijksinstituut voor Kust en Zee (RIKZ) in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De opdracht hield in het verkrijgen van biologische gegevens

Voedingpraktyke en behoeftes van hulpbron-arm gemeenskappe deur die oë van laerskoolonderwysers

Directory of Open Access Journals (Sweden)

Ronel Ferreira

2013-02-01

Full Text Available In hierdie artikel bespreek ons die persepsies van onderwysers (n = 45 wat betref die voedingpraktyke van ’n steekproef laerskoolleerders en hul gesinne in ’n hulpbron-arm gemeenskap. Ons fokus spesifiek op die behoeftes, praktyke en verwagtings ten opsigte van die gebruik van voedsel, wat die produksie, keuse en voorbereiding van voedsel impliseer. Ons studie vorm die eerste deel van ’n groter institusionele navorsingprojek. Vir die doel van ons studie het ons deelnemende refleksie en aksie-gebaseerde werkwinkels gehou om data te genereer en tydens die interpretasie van bevindinge op interpretivisme staatgemaak. Hierdie studie beklemtoon die behoeftes van hulpbron-arm en werklose gemeenskapslede wat dikwels genoodsaak is om teen verlaagde pryse voedsel te koop waarvan die kwaliteit nie optimaal is nie. ’n Verskraalde ontbyt, middagete of aandete waarvan die keuse algemeen beperk is tot swart tee, pap en een of twee snye ou brood, bevestig die manifestasies van armoede in hulpbron-arm gemeenskappe. Maaltye is dikwels beperk tot groot hoeveelhede koolhidrate, min groente, ingelegde vis, pap met inkomazi en marog. Hoenderpote en afval vul soms die spyskaart aan. Onderwysers beklemtoon die feit dat gemeenskapslede tipies op skenkings van werkgewers, kerke en kruidenierswinkels staatmaak om hul voedselbegroting aan te vul. Onderwysers fokus verder op die behoeftes aan opleiding vir gemeenskapslede. Na hulle mening moet gemeenskappe ingelig word oor voedselproduksie, groentetuine, die wyses waarop die kwaliteit van grond bepaal kan word, besproeiing en die toepassing van volhoubare wisselbou. Die artikel word afgesluit met uitvoerbare en leersame wenke vir die opleiding van landelike gemeenskappe. Op grond van dié navorsingsbevindinge word ’n intervensieprogram tans ontwikkel, met die doel om dit in die onderskeie deelnemende skole te implementeer ter bevordering van gesonde voedselverwante gedrag en welsyn.

An allene oxide and 12-oxophytodienoic acid are key intermediates in jasmonic acid biosynthesis by Fusarium oxysporum.

Science.gov (United States)

Oliw, Ernst H; Hamberg, Mats

2017-08-01

Fungi can produce jasmonic acid (JA) and its isoleucine conjugate in large quantities, but little is known about the biosynthesis. Plants form JA from 18:3 n -3 by 13 S -lipoxygenase (LOX), allene oxide synthase, and allene oxide cyclase. Shaking cultures of Fusarium oxysporum f. sp. tulipae released over 200 mg of jasmonates per liter. Nitrogen powder of the mycelia expressed 10 R -dioxygenase-epoxy alcohol synthase activities, which was confirmed by comparison with the recombinant enzyme. The 13 S -LOX of F. oxysporum could not be detected in the cell-free preparations. Incubation of mycelia in phosphate buffer with [17,17,18,18,18- 2 H 5 ]18:3 n -3 led to biosynthesis of a [ 2 H 5 ]12-oxo-13-hydroxy-9 Z ,15 Z -octadecadienoic acid (α-ketol), [ 2 H 5 ]12-oxo-10,15 Z -phytodienoic acid (12-OPDA), and [ 2 H 5 ]13-keto- and [ 2 H 5 ]13 S -hydroxyoctadecatrienoic acids. The α-ketol consisted of 90% of the 13 R stereoisomer, suggesting its formation by nonenzymatic hydrolysis of an allene oxide with 13 S configuration. Labeled and unlabeled 12-OPDA were observed following incubation with 0.1 mM [ 2 H 5 ]18:3 n -3 in a ratio from 0.4:1 up to 47:1 by mycelia of liquid cultures of different ages, whereas 10 times higher concentration of [ 2 H 5 ]13 S -hydroperoxyoctadecatrienoic acid was required to detect biosynthesis of [ 2 H 5 ]12-OPDA. The allene oxide is likely formed by a cytochrome P450 or catalase-related hydroperoxidase. We conclude that F. oxysporum , like plants, forms jasmonates with an allene oxide and 12-OPDA as intermediates. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

Beheersing van valse meeldauw in de akkerbouwmatige teelt van peterselie

NARCIS (Netherlands)

Mheen, van der H.J.C.J.; Lamers, J.G.

2009-01-01

In 2007 en 2008 heeft PPO-agv in opdracht van het Productwschap Akkerbouw onderzoek gedaan naar de beheersing van valse meeldauw in de akkerbouwmatige teelt van peterselie. Diverse fungicidentoepassingen zijn in staat om de peterselie (in meer of mindere mate) tegen valse meeldauw te beschermen.

Allen diesel standby sets at Sellafield

International Nuclear Information System (INIS)

Ruff, G.

1982-01-01

As part of the extension and improvement plans for the British Nuclear Fuels Ltd reprocessing facilities at Sellafield, three Allen diesel engines have been installed for essential standby duty. They are 16-cylinder V-form engines with a continuous rating of 2,832 bhp and drive a 2000kW 11,000 volt 3 phase 50Hz salient pole synchronous alternator at 750r/min. They are arranged for running in parallel and with the public electricity mains supply and are also controlled to operate as standby in the event of mains failure. To prevent radioactive contamination from the atmosphere, primary and secondary air filtration has been supplied for each engine. Other operational facilities and safeguards are mentioned and the cooling system described. (U.K.)

Inzicht in het presteren van de executieketen : Ontwikkeling van een monitor voor het meten van Kritieke Prestatie Indicatoren in de Executieketen

NARCIS (Netherlands)

Braak, S.W. van den; Netten, C.P.M.; Witzenburg, R. van

2013-01-01

Dit zijn de voorlopige resultaten van het ontwikkelprojcet Monitor Kritieke Prestatie Indicatoren Executieketen. Het structureel meten van de vastgestelde Kritieke Prestatie Indicatoren (KPI's) behelst het periodiek verzamelen, bewerken en presenteren van grote hoeveelheden data van verschillende

Vergelijking van vangsten van een 12 m pulskor met een conventionele wekkerboomkor

NARCIS (Netherlands)

Marlen, van B.; Ybema, M.S.; Kraayenoord, A.; Vries, de M.; Rink, G.J.

2005-01-01

In het kader van de ontwikkeling van een pulskor als alternatief voor de conventionele boomkor met wekkerkettingen werd in nov-dec 2004 en jan 2005 onderzoek uitgevoerd op het visserij-onderzoekingsvaartuig “Tridens” naar de vangstverschillen van beide visserijtechnieken en de overleving van door

Het gebruik van antropometrische gegevens bij het opstellen van normen voor kantoorstoelen

NARCIS (Netherlands)

Groot, M.D. de; Voorbij, A.I.M.; Molenbroek, J.F.M.

2003-01-01

De fysieke belasting van werknemers is bij het invoeren van de personal computer veranderd. De werkplekken zijn zitplekken geworden. Het aantal gebruikers van kantoorstoelen is daarmee enorm toegenomen. Achter een monitor zitten mensen vaak lang achter elkaar in dezelfde houding, wat in weerwil van

De verleidelijkheid van het grote gebaar : Het werk van Dogma

NARCIS (Netherlands)

Teerds, P.J.

2013-01-01

In vier portacabins op het parkeerterrein van de Delftse Faculteit Bouwkunde is nog tot volgende week de tentoonstelling 11+1 projects te zien, een overzichtstentoonstelling van het intrigerende werk van het Brusselse bureau Dogma. Met de tentoonstelling zet de faculteit na de brand in 2008 weer een

De afschaffing van de bezwaarfase bij boetebesluiten van de ACM

NARCIS (Netherlands)

Jans, J.H.; Outhuijse, A.

Per 1 maart 2013 ontstaat door samenvoeging van de NMa, de OPTA en de Consumentenautoriteit, de Autoriteit Consument en Markt. Om de ACM slagvaardig te laten functioneren, wordt voorgesteld het handhavingsinstrumentarium m.b.t. het markttoezicht van de ACM te vereenvoudigen. Eén van de voorstellen

Implementatie van de Surviving Sepsis Campaign bundels : Monitoring van ervaringen

NARCIS (Netherlands)

Lilian Vloet; J. Schouten; N. Stevens; A. Rensen; A. Willems; F. Zeegers

2011-01-01

Sepsis komt vaak voor in ziekenhuizen. Ernstige sepsis is verantwoordelijk voor 10 - 20% van alle Intensive Care (IC) opnames en is de belangrijkste doodsoorzaak op niet-cardiale IC?s. De gemiddelde mortaliteit van volwassenen met ernstige sepsis op de IC is 33% en van volwassenen met septische

Omkering van de bewijslast: knelpunten in de regeling en bij de toepassing van de omkering van de sanctie (deel I)

NARCIS (Netherlands)

Okhuizen, E.C.G.

2013-01-01

De omkering van de bewijslast als processuele sanctie op het niet nakomen van de aangifteplicht en de daaraan verbonden bijkomende verplichtingen lijken niet weg te denken uit ons belastingrecht. De sanctie kwam al voor in de fiscale wetgeving die dateert van vóór de invoering van de Algemene wet

Vervluchtiging van EPTC, tri-allaat en parathion na bespuiting van een kleigrond

NARCIS (Netherlands)

Bor, G.; Berg, van den F.; Smelt, J.H.; Peppel-Groen, van de A.E.; Leistra, M.

1995-01-01

Op tien tijdstippen na de bespuiting van een onbegroeide kleigrond met EPTC, tri-allaat en parathion werden de snelheden van vervluchtiging van deze middelen bepaald met de kapmethode en de theoretisch-profielmethode (TP-methode). De vervluchtiging was het hoogst op de dag van toepassing. In de

Enkele aspecten van de diagnostiek van hypophysaire insufficiëntie bij kinderen

NARCIS (Netherlands)

Israëls, Albertus Leonard Maurits

1960-01-01

In dit proefschrift is een onderzoek beschreven, dat naar de functie van de hypophyse bij kinderen met tekenen van hypophysaire insufficiëntie werd ingesteld. Het onderzoek werd in de kinderkliniek van het Academisch Ziekenhuis te Groningen verricht. In hoofdstuk I is een overzicht van de literatuur

VT-NRK Toepassing bioplastics : verbeteren van de technische eigenschappen van PLA-folies

NARCIS (Netherlands)

Molenveld, K.; Schennink, G.G.J.

2009-01-01

Het doel van dit project, VT-NRK toepassing bioplastics, is het genereren en verspreiden van kennis met betrekking tot het verbeteren van de technische eigenschappen van PLA folies. De kennis is bedoeld voor de bedrijven die binnen de kunststofindustrie aangesloten zijn bij de MJA én folies

Rituele van plesier: Dolf van Coller se Die Bieliebalies

Directory of Open Access Journals (Sweden)

J. van Wyk

1998-04-01

Full Text Available Rituals of pleasure: Dolf van Coller’s Die Bieliebalies This article is an analysis of Dolf van Coller's Die Bieliebalies (1993, read as a hedonist text. It has many points of similarity with what Bakhtin (1984 called grotesque realism, and with Nietzsche’s views as expounded in The birth of tragedy (1956. By comparing Van Caller's text to that of Bakhtin and Nietzsche, a counter-discourse to contemporary moral discourses such as feminism is explored. Van Coller’s use of laughter as a relativising mechanism is very liberating in the context where petty morality intervenes dogmatically in the field of literature and other spheres of life.

Die ontwikkeling van menslike potensiaal in die Republiek van Suid ...

African Journals Online (AJOL)

Erna Kinsey

Dit het dus ook te doen met lewenstandaard, aangesien lewenstandaard `n bepalende faktor is met betrekking tot die optimale ontwikkeling van menslike potensiaal. Ander minder materiële aspekte van menslike potensiaal het te doen met menslike vryheid, waaronder vryheid van spraak, beweging en keuse ter sake is.

Master Illustrator Allen Say Opens Students' Eyes to the Artist's Craft.

Science.gov (United States)

Brehl, Sandy

2002-01-01

Discusses how the author uses Allen Say's picture storybooks to introduce intimidating (even to adults!) artistic language and concepts. Elaborates on several books that she used with her third-grade students. Demonstrates that a meaningful encounter with a skilled artist can change the way students see art in literary experiences and in their…

Katalytisch verbranden van varkensmest

NARCIS (Netherlands)

Hendriks, J.

1995-01-01

Door het verbranden van mest kan het mestvolume worden verkleind. Binnenkort gaat op het Varkensproefbedrijf 'Zuid- en West-Nederland' in Sterksel onderzoek van start om de mogelijkheden van het katalytisch verbranden van varkensmest te bekijken.

Witte vlekken in het bereik van NME? : raamwerk voor het meten van gebruik en de effecten van NME in het primair onderwijs

NARCIS (Netherlands)

Vreke, J.; Langers, F.; Berg, van den A.E.

2011-01-01

In het NME-beleid wordt het geven van NME ingezet als instrument om bij te dragen aan het reduceren van de achteruitgang, in omvang en kwaliteit, van natuur en milieu. Het bereik van NME moet aangeven in hoeverre NME de bevolking heeft bereikt en aan dit doel heeft bijgedragen. Het identificeren van

Produktie van pigmenten

NARCIS (Netherlands)

Etman EJ; Duesmann HB; Eijssen PHM; LAE

1994-01-01

Dit rapport over de produktie van pigmenten is gepubliceerd binnen het Samenwerkingsproject Procesbeschrijvingen Industrie Nederland (SPIN). In het kader van dit project is informatie verzameld over industriele bedrijven of industriele processen ter ondersteuning van het overheidsbeleid op het

Het effect van het bijvoeren van tarwe aan vleeskuikens op de slachtrendementen

NARCIS (Netherlands)

Middelkoop, van J.H.; Harn, van J.

1994-01-01

Tarwe bijvoeren aan vleeskuikens staat momenteel volop in de belangstelling. Redenen hiervoor zijn de lage prijs van de tarwe en het positieve effect dat tarwe kan hebben op de resultaten en gezondheid van de koppel. Door het bijvoeren van tarwe wordt de werking van de spiermaag en de ontwikkeling

St. Teresa van Avila: sentrale figuur in die werk van Cussons en Van Wyk Louw

Directory of Open Access Journals (Sweden)

H. van Vuuren

1989-05-01

Full Text Available A central poem in Van Wyk Louw’s Tristia (1962, is “H. Teresa van Avila flap uit” (literally translated: “Saint Teresa of Avila talks too much/babbles uncontrollably”. This article illustrates how intertextual reading helped to clarify the poem. Teresa of Avila’s The way of perfection (a translation of the Spanish work El Camino de la Perfección, 1573 is the intertext of the Van Wyk Louw poem. In the last section of the article it is shown how the figure of St. Teresa of Avila is central not only to Van Wyk Louw’s Tristia (1962, but also to the oeuvre of Sheila Cussons, which underlines a strong intertextuality between these two Afrikaans oeuvres.

Origins Of Magnetospheric Physics An Expanded Edition

CERN Document Server

Van Allen, James A

2004-01-01

Early in 1958, instruments on the space satellites Explorer I and Explorer III revealed the presence of radiation belts, enormous populations of energetic particles trapped in the magnetic field of the earth. Originally published in 1983 but long out of print until now, Origins of Magnetospheric Physics tells the story of this dramatic and hugely transformative period in scientific and Cold War history. Writing in an accessible style and drawing on personal journals, correspondence, published papers, and the recollections of colleagues, James Van Allen documents a trail-blazing era in space hi

Effects of whistler mode hiss waves in March 2013

Czech Academy of Sciences Publication Activity Database

Ripoll, J.-F.; Santolík, Ondřej; Reeves, G. D.; Kurth, W. S.; Denton, M. H.; Loridan, V.; Thaller, S. A.; Kletzing, C. A.; Turner, D. L.

2017-01-01

Roč. 122, č. 7 (2017), s. 7433-7462 ISSN 2169-9380 R&D Projects: GA ČR(CZ) GA17-07027S; GA MŠk(CZ) LH15304 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : van allen probes * radiation-belt electrons * linear diffusion-coefficients Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2017JA024139/full

Die gebruik van ’n reologiese tegniek in die bepaling van die verhardingsreaksiekinetika van ’n reaktiewe poliësterpoeierdeklaag

Directory of Open Access Journals (Sweden)

O. C. Vorster

2004-09-01

Full Text Available

Die studie van die verhardingsreaksiekinetika van deklae word bemoeilik deur die aanwesigheid van vlugtige stowwe, pigmente en bypigmente. In hierdie studie word die verhardingsreaksiekinetika van ’n karboksielgetermineerde poliëstertriglisediel-isosianuraat deur middel van parallelplaatspanningsreometrie bepaal. Jeltye is verkry en skaleringseksponente bepaal. ’n Nuwe metode vir die voorspelling van die verloop van die reaksie word voorgestel en vergelyk met resultate verkry deur middel van differensiël skanderingskalorimetrie.

Abstract

The use of a rheological technique in the determination of the curing kinetics of a reactive polyester powder coating

In this article a study of the curing process of carboxyl terminated polyester-triglycidyl isocyanurate systems is reported. A comparison is made between the generally used Differential Scanning Calorimetric methods and rheokinetic methods, using a parallel plate oscillating stress rheometer. Gel times were determined and scaling exponents calculated. A new method for the estimation of the extent of reaction is presented and compared with results obtained by means of differential scanning calorimetry

Lognormal Kalman filter for assimilating phase space density data in the radiation belts

Science.gov (United States)

Kondrashov, D.; Ghil, M.; Shprits, Y.

2011-11-01

Data assimilation combines a physical model with sparse observations and has become an increasingly important tool for scientists and engineers in the design, operation, and use of satellites and other high-technology systems in the near-Earth space environment. Of particular importance is predicting fluxes of high-energy particles in the Van Allen radiation belts, since these fluxes can damage spaceborne platforms and instruments during strong geomagnetic storms. In transiting from a research setting to operational prediction of these fluxes, improved data assimilation is of the essence. The present study is motivated by the fact that phase space densities (PSDs) of high-energy electrons in the outer radiation belt—both simulated and observed—are subject to spatiotemporal variations that span several orders of magnitude. Standard data assimilation methods that are based on least squares minimization of normally distributed errors may not be adequate for handling the range of these variations. We propose herein a modification of Kalman filtering that uses a log-transformed, one-dimensional radial diffusion model for the PSDs and includes parameterized losses. The proposed methodology is first verified on model-simulated, synthetic data and then applied to actual satellite measurements. When the model errors are sufficiently smaller then observational errors, our methodology can significantly improve analysis and prediction skill for the PSDs compared to those of the standard Kalman filter formulation. This improvement is documented by monitoring the variance of the innovation sequence.

Handelsstromen van pluimveevlees

NARCIS (Netherlands)

Tacken, G.M.L.; Horne, van P.L.M.

2006-01-01

Dit onderzoek geeft inzicht in de goederenstromen van (rauw) pluimveevlees binnen envooral naar Nederland en de daarmee gepaard gaande zoönoserisico's. Het onderzoek biedtinput voor het nog op te zetten controlebeleid, waarmee handhaving van het beleidsvoornemenom het aanbieden van rauw

Bekalking en toevoegen van nutriënten; evaluatie van de effecten op de vitaliteit van het bos; een veldonderzoek naar boomgroei

NARCIS (Netherlands)

Wolf, R.J.A.M.; Engels, M.E.; Knotters, M.; Schraven, R.; Boertjes, M.

2006-01-01

Dit rapport doet verslag van een deelonderzoek uit de Evaluatie van effectgerichte maatregelen in multifunctionele bossen 2004-2005 en is gericht op de effecten van de maatregelen bemes-ting en bekalking in bossen als overbruggingsmaatregel in het kader van het Overlevingsplan Bos en Natuur (OBN).

Paradiplomacia y desarrollo económico en la región transfronteriza de Reynosa-McAllen

Directory of Open Access Journals (Sweden)

Karla María Nava Aguirre

2018-02-01

Full Text Available La paradiplomacia es un nuevo fenómeno de participación internacional de gobiernos locales y otras entidades no-estatales. La investigación tiene como objetivo analizar la construcción paradiplomática y observar el desarrollo económico en la región transfronteriza Reynosa-McAllen a partir del Tratado de Libre Comercio de América del Norte (TLCAN. Se utilizó la investigación cualitativa con un enfoque descriptivo. Los instrumentos de recolección de información fueron la revisión bibliográfica y la entrevista. Los hallazgos demuestran que las actividades de vinculación entre Reynosa y McAllen, obedecen al trabajo en equipo que se realiza principalmente entre el Gobierno Municipal de Reynosa, Gobierno del Estado de Tamaulipas y la organización McAllen Economic Development Corporation (MEDC, que han incrementado la inversión y empleo generando un desarrollo económico en esta región transfronteriza.

Die berekening van vloeiing in ’n roterende annulus deur die metode van kunsmatige saamdrukbaarheid

Directory of Open Access Journals (Sweden)

H. Grobler

1987-03-01

Full Text Available Die vloeiing van ’n onsaamdrukbare, viskeuse vloeier word ondersoek aan die hand van die numeriese oplossing van die gediskretiseerde Navier-Stokes- en kontinuiteitsbeheervergelykings. In die besonder word vloeiing in ’n annulus bestaande uit twee koaksiale silinders wat elk ten opsigte van die ander kan roteer, en met ’n voorgeskrewe drukval oor die lengte van die silinder, beskou. Die oplossings word bereken deur die toepassing van Chorin se metode van kunsmatige saamdrukbaarheid, waarin die tydonafhanklike beheervergelykings getransformeer word na tydafhanklike hulpvergelykings deur die invoering van ’n kunsmatige toestandsvergelyking. Die oplossing van die hulpvergelykings konvergeer na ’n stasionêre oplossing, wat ooreenstem met die oplossing van die oorspronklike tydonafhanklike beheervergelykings. Die gedrag van die vloeier, wanneer ten voile ontwikkelde laminêre vloeiing bereik word, is met sukses bereken. ’n Eenvoudige model vir die bepaling van ontwikkeling van vloeiing langs die annulus vir enige gegewe invloeisnelheidsprofiel word voorgestel. Die berekende resultate stem ooreen met die resultate wat uit die fisika van die probleem verwag word.

Het format van de stad. Een evaluatie van recente Nederlandse stadsgeschiedenissen

Directory of Open Access Journals (Sweden)

P. Kooij

2002-01-01

Full Text Available R. Kunst, Leeuwarden 750-2000. Hoofdstad van Friesland; A. van der Schoor, N. Schadee, Stad in aanwas. Geschiedenis van Rotterdam tot 1813; P. van de Laar, Stad van formaat. Geschiedenis van Rotterdam in de negentiende en twintigste eeuw; R.E. de Bruin, 'Een paradijs vol weelde'. Geschiedenis van de stad Utrecht.The shape of the city. An evaluation of recent historical studies on Dutch townsUrban history in the Netherlands started roundabout 1970. It was initially promoted by mainly economic and social historians who used concepts derived from geography which centred on town and country relations, urban networks, and migration. The spatial factor was considered to be a core feature, also inside the towns and cities. An alternative view, however, argued that a completely introspective urban history, focussing on one city, would result in more integration. This hypothesis has been proved in a number of recent, more or less integral urban histories, commissioned by several independent municipal authorities in individual cities. They show that a combination of internal and external elements offers the best results with regard to integration.

Psigologiese benadering van pastorale arbeid

Directory of Open Access Journals (Sweden)

D. J. Strümpfer

1969-03-01

Full Text Available In die spreektaal van ons Afrikaanse kerke is ons lief om die bedienaar van die Woord aan te dui as „die predikant”, „die leraar” of „die dominee”. Miskien plaas ons met hierdie semantiese gebruik van terme wat lering en proklamering impliseer, ’n ongelukkige klem op die preekamp. Daarteenoor, het ons semanties miskien iets te leer van die Pinkstersektes wat die benaming „pastoor” verkies, of die Amerikaanse ge­ bruik van die term „the pastor”. Ons is wel lief om te praat van „ons herder en leraar”. Veelal word die herderlike, of pastorale, deel van die taak van die bedienaar van die Woord egter in sy eie gedagtes, asook in die gedagtes van sy gemeentelede, deur die leraarskap op die agtergrond gedwing. Al te dikwels word hy deur gemeentelede beskou as iemand wat op Sondag op die kansel gesien moet word en wat niks met die res van hul lewens te doen het nie. Herstel van die pastoraat sal deel moet wees van die proses om die ontkerstening van die hedendaagse lewe teen te gaan.

Mindfulness voor volwassenen met een licht verstandelijke beperking

NARCIS (Netherlands)

Punt, M.; Helmond, P.E.; Meirmans, M.; Otten, R.; Speckens, A.E.M.

2016-01-01

Mensen met een licht verstandelijke beperking (LVB) hebben veelal te maken met een opeenstapeling van verschillende biologische, psychologische en sociale factoren, waardoor zij vijf tot zes keer meer kans hebben op het ontwikkelen van psychopathologie dan normaal begaafden (Allen, 2008; Buckles,

Verlies van (thuis en haard. Het belang van verliesbegeleiding als onderdeel van de maatschappelijke begeleiding binnen het Vluchtelingenwerk, regio Utrecht

Directory of Open Access Journals (Sweden)

Birgit Hoogenberk

2014-06-01

Full Text Available Loss of home and house. The importance of loss counseling as a part of refugee social supportIn this article it is advocated that it is important that the implementation of loss counseling is part of social support for refugees, also called integrative eclectic working. Social support from VluchtelingenWerk, also known as Refugee Council, is about supporting the client in an effective manner with their personal problems which can hinder their integration. Because the target group of VluchtelingenWerk is a group of people whom have suffered many losses, attention should be brought to this subject. Unfortunately in current work methods there is no room for loss counseling, partly due to the lack of methodological tools. The losses associated with this group have a lot of impact on their daily lives and often are the source of functional limitations. By offering loss counseling and multi-method grief counseling, volunteers and employees are offered tools to make loss more negotiable. In this article different examples will be discussed and the new loss model of Stroebe and Schut will be explained. What will be clarified is the importance of the implementation of loss counseling, for the well-being and the integration process of clients as well as achieving organizational goals.Verlies van (thuis en haard. Het belang van verliesbegeleiding als onderdeel van de maatschappelijke begeleiding binnen het VluchtelingenWerk, regio UtrechtIn dit artikel wordt gepleit voor het implementeren van verliesbegeleiding als onderdeel van de maatschappelijke begeleiding, er is sprake van integratief eclectisch werken. De maatschappelijke begeleiding van het VluchtelingenWerk heeft als taak de cliënt zo goed mogelijk te begeleiden bij persoonlijke problemen die de inburgering kunnen belemmeren. Aangezien de doelgroep van het VluchtelingenWerk bestaat uit mensen die ontzettend veel verliezen hebben geleden dient hier aandacht voor te zijn. Helaas is in de huidige

Economische gevolgen van ontwapening

NARCIS (Netherlands)

Duisenberg, Willem Frederik

1965-01-01

Samenvatting van de gehele studie 4.1. Economie en ontwapening Ontwapening betekent in deze studie de algehele, snelle afschaffing van alle militaire maatregelen in aIle landen. Het negeren van de politieke waarschijnlijkheden die veeleer wijzen op een zeer geleidelijke afschaffing van slechts

Neurotoxische effecten van broomcyclohexaan

NARCIS (Netherlands)

Velsen; F.L.van; Danse; L.H.J.C.; Vries; L.J.de; Liefde; A.de

1984-01-01

Kortdurende toediening (4-7 dagen) van broomcyclohexaan (BCH) veroorzaakt in een dosering van 1200 mg/kg lichaamsgewicht (per maagsonde) necrose van gegranuleerde cellen in de korrellaag van de kleine hersenen. In deze doseringen zijn ook gedragsafwijkingen waargenomen d.m.v. een objectieve

Evaluatie van het gebruik van de iPad in het klaslokaal : Een onderzoek naar het iPadgebruik onder brugklasleerlingen van een Leeuwarder Lyceum

NARCIS (Netherlands)

Klaas Jan Huizing; Chantal Philipsen; Luka Linster

2013-01-01

In november 2012 kregen alle brugklasleerlingen van het Leeuwarder Lyceum een iPad uitgereikt. Dit nieuwe ‘device’ is de aanjager van onderwijsvernieuwingen op het gebied van digitalisering van lesmateriaal. Sowijs volgde de implementatie van de iPad en vroeg zich af: hoe is het iPadgebruik na een

Leven en werken van Geert Reinders. De grondlegger van de immunologie.

NARCIS (Netherlands)

Bruins, Luitje Hendrik

1951-01-01

De levensgeschiedenis van Geert Reinders is het relaas van de vele prestaties, waartoe deze man ondanks een zeer gebrekkige schoolopleiding in staat was. Hij was werkzaam als molenaar, boer, koopman, redger, gemeentesecretaris, secretaris en ontvanger van een groot zijlvest, veeartsenijdeskundige;

Die rol van die blanke werker in die motivering van die swart werker

Directory of Open Access Journals (Sweden)

G. J. Oosthuizen

1980-11-01

Opsomming Die motivering van die Swart werker kan nie in die huidige situasie in isolasie bestudeer word nie, omdat die Blanke werker steeds in die bestuursposisie is en daarom die motivering van die Swart werker kan beïnvloed. Hierdie ondersoek was daarop gerig om die rol van die Blanke werker in die motivering van die Swart werker nader te ondersoek. Die houding en die leierskapsbenadering van die Blanke werker teenoor die Swart werker is gemeet, asook die behoeftes wat volgens die Blanke werker by die Swart werker bestaan, bevredig is, of nie bestaan nie. Die behoeftes van Swart werkers, soos deur hulleself gesien, is ook ondersoek. Ten opsigte van sekere aspekte is beduidende verskille gevind.

De eeuw van de Beeldenstorm

Directory of Open Access Journals (Sweden)

F. Postma

1988-01-01

Full Text Available P. van Boheemen, N.P.J. van der Lof, E. van Meurs, Het boek in Nederland in de 16e eeuw S. Groenveld, Ketters en papen onder Filips II. Het godsdienstig leven in de tweede helft van de zestiende eeuw R. Kistemaker, M. Jonker, De smaak van de elite. Amsterdam in de eeuw van de Beeldenstorm W.Th. Kloek, Kunst voor de Beeldenstorm. Noord-Nederlandse kunst ca 1525-1580, [I], Inleiding, [II, Catalogus] J.R. ter Molen, A.P.E. Ruempol, A.G.A. Dongen, Huisraad van een molenaarsweduwe. Gebruiksvoorwerpen uit een 16e eeuwse boedelinventaris M. de Roever, B. Bakker, Woelige tijden. Amsterdam in de eeuw van de Beeldenstorm I.M. Veldman, Leerrijke reeksen van Maarten van Heemskerck

Benaderingen van over

NARCIS (Netherlands)

Boer, M.G. de

2010-01-01

SAMENVATTING In dit hoofdstuk wordt de relatie tussen de betekenissen van het Nederlandse voorzetsel over en een aantal corpora bestudeerd. Het hoofdstuk begint met een analyse van de voorbeelden uit Uit het leven van Dik Trom (1891); daarna wordt de woordenboekinformatie behandeld en vergeleken

Die effek van intelligensie op die verhouding tussen lokus van kontrole en taakkompleksiteit

Directory of Open Access Journals (Sweden)

F. G. de Kock

1995-06-01

Full Text Available The effect of intelligence on the relationship between locus of control and task complexity. The aim of the study was to establish the effects of intelligence on the relationship between locus of control and task complexity. These constructs were selected by virtue of their importance in the literature, as well as the lack of empirical research regarding the assumed relationship which exists between them. The Human Sciences Research Council's (HSRC General Scholastic Aptitude Test (ASAT was used for measuring intelligence, Duttweiler's Internal Control Index (ICI was used for determining locus of control and the Raven's Advanced Progressive Matrices (APM was used as a criterion for coping with task complexity. These instruments were administered to 292 subjects to determine whether the relationship between locus of control and task complexity was effected when the effect of intelligence was controlled. The results indicated a significant relationship between locus of control and task complexity, however the relationship was no longer significant after the effect of intelligence was controlled. Opsomming Die doel van die studie was om die effek van intelligensie op die verhouding tussen lokus van kontrole en taak-kompleksiteit te ondersoek. Hierdie konstrukte is gekies na aanleiding van hulle belangrikheid in die literatuur asook die leemte in empiric se navorsing rakende die veronderstelde verband wat tussen hulle bestaan. Die Algemene Skolastiese Aanlegtoets (ASAT van die Raad vir Geesteswetenskaplike Navorsing (RGN is gebruik vir die meting van intelligensie, die Internal Control Index (ICI van Duttweiler is gebruik vir die meting van lokus van kontrole en die Advanced Progressive Matrices (APM van Raven is gebruik as maatstaf vir die bantering van taakkompleksiteit. Die genoemde meetinstrumente is op 292 proefpersone toegepas om te bepaal of die verband tussen lokus van kontrole en taakkompleksiteit geaffekteer word wanneer daar vir die effek

Ziekten van het ruggenmerg

NARCIS (Netherlands)

Groen, Robertus; Kuks, Joannes; Snoek, Jozef; Kuks, Jan B.M.; Snoek, Jos W.

2016-01-01

Er zijn vele oorzaken voor een myelopathie. Beschadiging van het myelum kan compleet zijn (zoals in het geval van een complete dwarslaesie), maar is vaker incompleet (zoals bij een incomplete traumatische dwarslaesie en de meeste vormen van myelopathie op basis van niet-traumatische oorzaken). Er

Analyse van de vervormingen van de Fusee Ceramique daken van de productiehallen in Dongen : Rapport met bevindingen betreffende de vervormingen van de Fuseedaken van de productiehallen van Coca Cola in Dongen

NARCIS (Netherlands)

Kamerling, M.W.

2014-01-01

In 1962 werden in Dongen bedrijfshallen gemaakt met cilindervormige overkappingen waarin ter besparing van gewicht en cement ceramische elementen, de Fusée's Ceramique, werden gelegd. De schalen worden ondersteund met balken 450*750 mm2 en kolommen 450 * 450 mm2 op een raster van 5,6 m * 20,4 m. Het

Effectiviteit van facultatief aansluitonderwijs wiskunde in de transitie van voortgezet naar hoger onderwijs

NARCIS (Netherlands)

Tempelaar, D.T.; Rienties, B.; Kaper, W.; Giesbers, B.; Gastel, van L.J.; Vrie, van de E.M.; Kooij, van der H.; Cuypers, H.

2011-01-01

Samenvatting Wat is het effect van vrijwillig aansluitonderwijs, zoals het remediërend wiskundeonderwijs dat op veel instellingen voor hoger onderwijs wordt gegeven ter verbetering van de doorstroom? Bepaling van de doelmatigheid van dit onderwijs wordt bemoeilijkt door selectie-effecten die kunnen

De opdeling van Centraal-Afrika, 1875-1885 : een analyse van twee territoriale conflicten

NARCIS (Netherlands)

Foeken, D.W.J.

1992-01-01

Deze studie beschrijft een politiek-historisch proces en vormt een bijdrage aan de systematische studie van internationale territoriale conflicten vanuit het gezichtspunt van de politieke geografie. Tevens worden aspecten van het Europese imperialisme van de late 19e eeuw nader verklaard. De

De economische kracht van de baggerindustrie: clusterstudie met behulp van de 'methode Porter'

NARCIS (Netherlands)

Jacobs, D.; Limpens, I.; Kuijper, J.; Ven, B. van de

1993-01-01

Deze clusterstudie van de Nederlands-Belgische baggerindustrie is uitgevoerd in opdracht van IHC Holland, de belangrijkste bouwer van baggerschepen ter wereld, en de Vereniging Centrale Baggerbedrijf, de branche-organisatie van aannemers in de bagger. De bedoeling is een beter inzicht te krijgen in

Maatskaplike aspekte van geriatriese sorg

Directory of Open Access Journals (Sweden)

D. Louw

1979-09-01

Full Text Available Dit is maar enkele dekades gelede dat Westerse gemeenskappe bewus geword het van die besondere behoeftes van die relatief groot en nog steeds groeiende persentasie bejaardes in hulle midde. Nie alleen het die liggaamlike behoeftes van liggaamlike afgetakelde bejaardes die aandag getrek nie maar die gemeenskappe het ook bewus geword van die maatskaplike behoeftes van ouerwordendes in ’n tydperk wat gekenmerk is deur die dramatiese veranderings in die lewenswyses van ons mense — veranderinge wat in baie opsigte ’n negatiewe invloed gehad het op die lewensomstandighede van ’n groot groep bejaardes. Welsynsbeplanners het besef dat hulle in hulle beplanning spesiale voorsiening moes maak vir die lewensbehoeftes van hierdie groep in die gemeenskap en dat hulle in die verband ’n groot agterstand het om in te haal. Geneeshere wat belang begin stel het in die gesondheidsbehoeftes van bejaardes het ook besef dat gevestigde geneeskundige praktyke geensins voldoen aan die spesifieke behoeftes van ’n groot groep bejaardes nie en dat groot aanpassings gemaak moes word met betrekking tot hulle benaderings en metodes van behandeling van hierdie pasiente.

Betekenis van Legionella-soorten voor preventiebeleid van leidingwaterinstallaties

NARCIS (Netherlands)

Versteegh JFM; Brandsema PS; Lodder WJ; de Roda Husman AM; Schalk JAC; van der Aa NGFM; IMG; LZO; EPI

2009-01-01

Het RIVM adviseert om de huidige normstelling voor het preventiebeleid van Legionella te handhaven en niet uitsluitend op Legionella pneumophila te richten. Als andere Legionella-soorten worden aangetroffen kan er ook groei van Legionella pneumophila optreden. Als er dan geen maatregelen worden

Update on the Active Magnetospheric Particle Tracer Explorers (AMPTE) program

International Nuclear Information System (INIS)

Mcentire, R.W.

1987-01-01

The principles involved in the AMPTE mission's active experiments are discussed together with the role of the AMPTE satellites (the Germany's Ion Release Module, IRM, the United Kingdom Subsatellite, and the U.S Charge Composition Explorer, CCE) in and the results of the ion-release experiments. The AMPTE orbit profile is described, with the times of solar-wind and magnetotail ion releases (two barium and two lithium releases were carried out as the IRM precessed through the magnetosheath) shown schematically. In addition to the results on the Van Allen radiation belts obtained through the ion-release experiments, studies of the radiation belts with the new generation of sensors aboard the CCE and IRM are described. 25 references

Plausibiliteitsdocument STONE 2.0 (Globale verkenning van de plausibiliteit van het model STONE versie 2.0 voor de modellering van uit- en afspoeling van N en P).

NARCIS (Netherlands)

Overbeek, G.B.J.; Beusen, A.H.W.; Boers, P.C.M.; Born, van den G.J.; Groenendijk, P.; Grinsven, van J.J.M.; Kroon, T.; Meer, van der H.G.; Oosterom, H.P.; Puijenbroek, van P.J.T.M.; Roelsma, J.; Roest, C.W.J.; Rötter, R.; Tiktak, A.; Tol, van S.

2002-01-01

STONE is ontwikkeld om landsdekkend voor Nederland de effecten van bemesting en mestbeleid op de emissies van stikstof en fosfaat uit de landbouw naar grond- en oppervlaktewater te verkennen. De nadruk in de hier gerapporteerde plausibiliteitsstudie ligt op vaststelling van de geloofwaardigheid, het

Plausibiliteitsdocument STONE 2.0.Globale verkenning van de plausibiliteit van het model STONE versie 2.0 voor de modellering van uit -en afspoeling van N en P

NARCIS (Netherlands)

Overbeek GBJ; Beusen AHW; Boers PCM; Born GJ van den; Groenendijk P; Grinsven JJM; Kroon T; Meer HG van der; Oosterom HP; Puijenbroek PJTM van; Roelsma J; Roest CJW; Rotter R; Tiktak A; Tol S van; LBG; CIM; LAE; LWD

2002-01-01

STONE is ontwikkeld om landsdekkend voor Nederland de effecten van bemesting en mestbeleid op de emissies van stikstof en fosfaat uit de landbouw naar grond- en oppervlaktewater te verkennen. De nadruk in de hier gerapporteerde plausibiliteitsstudie ligt op vaststelling van de geloofwaardigheid,

Geochemische bodematlas van Nederland

NARCIS (Netherlands)

Mol, G.; Spijker, J.H.; Gaans, van P.; Römkens, P.F.A.M.

2012-01-01

Deze Geochemische bodematlas geeft een uniek overzicht van de chemische samenstelling van de bodem in Nederland. Bodemmonsters van meer dan 350 locaties zijn geanalyseerd op meer dan 40 chemische elementen. De atlas geeft niet alleen informatie over de door de mens beïnvloede toplaag van de bodem,

Evaluatie van bemesting en bekalking in bossen en de ontwikkeling van onbehandelde bossen

NARCIS (Netherlands)

Olsthoorn, A.F.M.; Berg, van den C.A.; Gruijter, de J.J.

2006-01-01

Dit rapport doet verslag van een deelonderzoek uit de Evaluatie van effectgerichte maatregelen in multifunctionele bossen 2004-2005 en is gericht op de effecten van de maatregelen bemesting en bekalking in bossen als overbruggingsmaatregel in het kader van het Overlevingsplan Bos en Natuur (OBN). Na

Die meting van die gelyktydige hantering van teenstrydige en dubbelsinnige inligting as kritieke eienskap in 'n verskeidenheid van Beroepe

Directory of Open Access Journals (Sweden)

W. S. de Villiers

1983-11-01

Min informasie bestaan omtrent die hantering van teenstrydige en dubbelsinnige inligting as kritieke vermoë in vele werksituasies. Met hierdie ondersoek is daar gepoog om die konstruk te omlyn en aan 'n empiriese verifiering te onderwerp. ‘n Meetinstrument (posmandjie is ontwikkel om die hantering van teenstrydige en dubbelsinnige inligting te meet en is saam met ander meetinstrumente ter omlyning van die genoemde konstruk aan twee groepe proefpersone geadministreer. Daar is vasgestel dat hierdie vermoë verband hou met intellektuele vermoëns en sensories kognitiewe oordeel en nie met sekere persoonlikheids- en ander determinante van mens like gedrag nie en dat dit na alle waarskynlikheid dui op die bestaan van 'n afsonderlike werksvermoë of konstruk.

Een traditie herneemt zich - Over het belang van Aldo van Eyck

NARCIS (Netherlands)

Colenbrander, B.J.F.

1997-01-01

Zo'n zeven, acht jaar geleden veranderde Aldo van Eyck, overigens bij leven en welzijn, van een lijfelijk deelnemer aan de architectuurdiscussie in een historische figuur. Hij werd verguisd en gelauwerd. Met de Rekenkamer in Den Haag echter doet Van Eyck lang vergeten manifesten herleven. Gloort er

Het belang van beschermende factoren in de risicotaxatie van tbs-gestelden

NARCIS (Netherlands)

Nagtegaal, M.H.; Schönberger, H.J.M.

2013-01-01

In dit onderzoek staan de volgende vragen centraal: Is het meenemen van beschermende factoren van toegevoegde waarde voor de risicotaxatie zoals deze plaatsvindt in de tbs-praktijk? Zo ja, op welke manier? Hierbij wordt onder ander het belang van beschermende factoren voor de behandelpraktijk en de

Een geschiedenis van vleesloos eten

NARCIS (Netherlands)

Dagevos, H.

2009-01-01

Recensie van de populaire editie van het proefschrift van Dirk-Jan Verdonk: Het dierloze gerecht: een vegetarische geschiedenis in Nederland. Hierin wordt de geschiedenis van het vegetarisme vanaf de tweede helft van de 19e eeuw tot nu beschreven

Een nieuwe ondersoort van Zosterops montana afkomstig van de Goenoeng Papandajan (West Java)

NARCIS (Netherlands)

Hoogerwerf, A.; Boer, de L.E.

1947-01-01

In zijn laatste revisie van het genus Zosterops (Journ. für Orn., vol. 87, 1939, p. 156-164) geeft Stresemann o.a. een schematische voorstelling van de horizontale en verticale verspreiding binnen deze Archipel van de vier voornaamste groepen van dit geslacht: montana, atricapilla, palpebrosa en

Naar meer bruto nationaal sportgeluk? Verkenning van de rol van sport in geluk

NARCIS (Netherlands)

Dool, R. van den; Breedveld, K.

2017-01-01

Op verzoek van NOC*NSF heeft het Mulier Instituut, met financiële steun van het ministerie van VWS, een verkenning uitgevoerd naar de relatie tussen sport en geluk. NOC*NSF en de Nederlandse sportbonden streven, als onderdeel van het 'transitietraject', ernaar om duidelijker voor het

Gebruik van TaqMan PCR voor het kwantificeren van Fusarium spp. en Microdochium nivale in gewassen en gewasresten van tarwe

NARCIS (Netherlands)

Köhl, J.; Haas, de B.H.; Kastelein, P.; Burgers, S.L.G.E.; Waalwijk, C.

2005-01-01

Samenvattingen van 5 presentaties: 'Heterogenity of Dutch Fusarium oxysporum strains isolated as forma specialis radicis-lycopersici';'Een proteomics benadering om eiwitten te identificeren die door Fusarium oxysporum worden uitgescheiden in xyleemsap van tomaat'; 'Ontwikkeling en implementatie van

Richtlijnen voor selectie en weergave van residugehaltes van bestrijdingsmiddelen

NARCIS (Netherlands)

van den Velde-Koerts T; van Hoeven-Arentzen PH; Ossendorp BC; CSR

2002-01-01

Residubeoordelingen van bestrijdingsmiddelen worden uitgevoerd om wettelijke residulimieten (MRLs = maximum residue limits) vast te leggen. MRLs worden afgeleid uit de resultaten van die residuproeven met bestrijdingsmiddelen die volgens kritisch "Good Agricultural Practice" zijn

Toepassing van optische sensoren (I). Meting van bellengrootteverdeling in luchtige levensmiddelen.

NARCIS (Netherlands)

Bisperink, C.G.J.; Akkerman, J.C.; Prins, A.

1991-01-01

Beschrijving van een methode, ontwikkeld op het laboratorium voor Zuivel en Levensmiddelennatuurkunde van de LU Wageningen in nauwe samenwerking met de TU Delft, waarmee goed en snel de verdeling van de gasfase in de vloeibare fase in de tijd en op verschillende plaatsen in een monster kan worden

van der Waals

Indian Academy of Sciences (India)

University education was beyond reach for van der Waals as he had to work for earning his daily bread ... languages, which was a prerequisite for entering a University those days. van der Waals worked as a school ... take academic examinations at the University yet, van der Waals continued studying at Leiden. University ...

Het beslissingsproces van de huisarts bij de keuze van een geneesmiddel

NARCIS (Netherlands)

B. Wierenga (Berend); S.J.T. Jong; A. Mantel

1989-01-01

textabstractHet beslissingsproces van de huisarts bij de keuze van een geneesmiddel, zoals het uit dit empirisch onderzoek naar voren kwam, kan als volgt worden getypeerd. In het merendeel van de gevallen (ca. 90%) beperkt de arts zich tot de informatie die hij al in zijn geheugen heeft. Vaak wordt

Vaststellen reproduceerbaarheid van de nachtactiviteit van de Balb/c/rivm muis over de afgelopen vijf jaar

NARCIS (Netherlands)

Steen BVL; Jansen van ' t Land C; CDL

1999-01-01

Om de inschatting van de mate van ongerief onafhankelijk te maken van ervaring en interpretatie van de persoon die de observatie uitvoert, maken wij in onze studies gebruik van een volledig geautomatiseerde opstelling. Met deze geautomatiseerde opstelling kan de bewegingsactiviteit van

Bereiding van gevriesdroogd cholesterolcalibratie en -controleserum ten behoeve van de Stichting Kwaliteitsbewaking Chemische Analyse ten behoeve van Epidemiologisch Onderzoek (KCA)

NARCIS (Netherlands)

Dreumel; H.J.van; Wikkeling; R.H.; Steentjes; G.M.; Buitenhuis; S.G.; Koedam; J.C.

1986-01-01

In het kader van de samenwerking tussen het RIVM en de Stichting KCA (Kwaliteitsbewaking Chemische Analyse t.b.v. Epidemiologisch Onderzoek) werden drie partijen cholesterolserum bereid. Uitgegaan werd van menselijk serum (Centraal Laboratorium van de Bloedtransfusiedienst). Door uit een deel

De auteursrechtelijke groeipijnen van Google

NARCIS (Netherlands)

Hugenholtz, P.B.

2011-01-01

Het succesverhaal van Google behoort tot de canon van de geschiedenis van onze informatiemaatschappij. In 1998 begonnen in een studentenkamer op de campus van Stanford University, groeide Google in enkele jaren uit tot het orakel van het internet. Zo werd ‘googelen’ de gebruikelijke term voor zoeken

Beoordeling van de gevoeligheid van soorten en habitattypes van Europees belang bij verstoringingrepen

OpenAIRE

Wouters, Jan

2011-01-01

Om ecologische schade te vermijden, moeten activiteiten of plannen met mogelijk schadelijke effecten doorgelicht worden. Het instrument ‘effectenindicator’ licht activiteiten in algemene termen door op mogelijke natuureffecten. De in dit advies weergegeven gevoeligheidstabellen geven de gevoeligheid op van soorten en biotopen voor effecten ten gevolge van menselijke activiteiten. De tabellen bevatten deze gegevens voor de soorten waarvoor gewestelijke instandhoudingsdoelstellingen zijn opgest...

De consequenties van categorieën: een analyse van grensoverschrijdende genre-identiteit in de populaire muziek

NARCIS (Netherlands)

van Venrooij, A.; Schmutz, V.

2013-01-01

Op basis van een analyse van de genreclassificaties door recensenten van 2951 popmuziekalbums worden in dit paper de consequenties onderzocht van het bezitten van een fuzzy of grensoverschrijdende genre-identiteit op het vergaren van commercieel en kritisch succes. De resultaten bevestigen in grote

Advies voor de toepassing van ground-penetrating radar bij de inventarisatie van de grondwaterdynamiek

NARCIS (Netherlands)

Knotters, M.

2001-01-01

Ground-penetrating radar (GPR) biedt mogelijk een nauwkeurig alternatief voor arbeidsintensieve metingen van de grondwaterstand in boorgaten. De GPR-metingen kunnen als hulpinformatie dienen bij geostatistische interpolatie van grondwaterstanden. Op basis van literatuurstudie en verkenning van het

Quantitative mid-infrared spectra of allene and propyne from room to high temperatures

KAUST Repository

Es-sebbar, Et-touhami; Jolly, A.; Benilan, Y.; Farooq, Aamir

2014-01-01

Allene (a-C3H4; CH2CCH2) and propyne (p-C3H4; CH3C2H) have attracted much interest because of their relevance to the photochemistry in astrophysical environments as well as in combustion processes. Both allene and propyne have strong absorption in the infrared region. In the present work, infrared spectra of a-C3H4 and p-C3H4 are measured in the gas phase at temperatures ranging from 296 to 510 K. The spectra are measured over the 580-3400 cm-1 spectral region at resolutions of 0.08 and 0.25 cm-1 using Fourier Transform Infrared spectroscopy. Absolute integrated intensities of the main infrared bands are determined at room temperature and compared with values derived from literature for both molecules. Integrated band intensities are also determined as a function of temperature in various spectral regions.

Quantitative mid-infrared spectra of allene and propyne from room to high temperatures

KAUST Repository

Es-sebbar, Et-touhami

2014-11-01

Allene (a-C3H4; CH2CCH2) and propyne (p-C3H4; CH3C2H) have attracted much interest because of their relevance to the photochemistry in astrophysical environments as well as in combustion processes. Both allene and propyne have strong absorption in the infrared region. In the present work, infrared spectra of a-C3H4 and p-C3H4 are measured in the gas phase at temperatures ranging from 296 to 510 K. The spectra are measured over the 580-3400 cm-1 spectral region at resolutions of 0.08 and 0.25 cm-1 using Fourier Transform Infrared spectroscopy. Absolute integrated intensities of the main infrared bands are determined at room temperature and compared with values derived from literature for both molecules. Integrated band intensities are also determined as a function of temperature in various spectral regions.

Vrouekarakters in enkele prosawerke van C.M. van den Heever

Directory of Open Access Journals (Sweden)

E. Botha

2003-08-01

Full Text Available The role of women in some prose works of C.M. van den Heever Re-reading the C.M. van den Heever “classics” Somer (1935 and Laat vrugte (1939 within the framework of Van den Heever criticism through the years, one becomes aware that central themes in his oeuvre are acted out by women. The beautiful young girl Linda in Somer embodies the sadness of the transcience of beauty and happiness. Through Ouma Willa, Betta and Johanna – three women from three generations in Laat vrugte – the theme of the endurance of the memory of love and passion beyond decay and death is expressed. A cursory examination of other and earlier works by Van den Heever – Op die plaas (1927, Langs die grootpad (1928, Kromburg (1937 and the short story “Leuens” (Lies from Vuurvlieg en sterre (1934 – bears out the observation that women express core meanings in C.M. van den Heever’s prose works.

Tranen van bloed : Het beleg van 's-Hertogenbosch en de oorlog in de Nederlanden, 1629

NARCIS (Netherlands)

Cauwer, de Peter

2008-01-01

Het beleg van 's-Hertogenbosch en de veldtocht van 1629 staat in de Nederlandse geschiedschrijving te boek als een van de meest roemruchte gebeurtenissen van de Tachtigjarige Oorlog. Het beeld en de interpretaties van deze gebeurtenis zijn de afgelopen decennia nauwelijks veranderd. Toch bleven de

Onderdeel: Kwaliteit van uitleg, deel uitmakend van het onderzoek naar: Corporate governance in Nederland

NARCIS (Netherlands)

Schutte-Veenstra, J.N.; Boschma, H.E.

2011-01-01

De wijze en mate van naleving en toepasing van de principes en best practices van de nederlandse corporate governance code door de Nederlandse beursgenoteede vennootschappen in ht boekjaar 2010, alsmede de redengeving van eventuele afwijkingen, d.d. 21 september 2011.

Groei van ongelijkjarige mengingen van grove den en berk op arme zandgronden; resultaten van metingen in 22 opstanden op de Veluwe en de Sallandse Heuvelrug

NARCIS (Netherlands)

Wijdeven, S.M.J.; Oosterbaan, A.; Berg, v.d. C.; Jole, van M.

2000-01-01

Het voorkomen en de groei van berk in ongelijkjarige mengingen van grove den en berk is bepaald op basis van opstandgemiddelden. Er is geen duidelijk verband tussen het voorkomen en de groei van berk en de schermdichtheid van grove den. Actuele groeigegevens zijn noodzakelijk voor een nadere

Die meting van die invloed van organisasiegrootte op bruin werkers se houdings en gedrag

Directory of Open Access Journals (Sweden)

R. van der Bank

1985-11-01

'n Oorsig van die literatuur dui daarop dat bevindinge onkonsekwent is wat betref die invloed van die grootte van organisasies op veranderlikes soos die doeltreffendheid van personeel-keuringstelsels, opleiding, arbeidsomset, werkafwesigheid, werkdoeltreffendheid en so meer. In Wes-Kaapland is tien "groot" fabrieke geselekteer (aantal bruin werkers 300 of meer en vergelyk met 17 "klein" fabrieke (aantal bruin werkers minder as 50. Met behulp van t-toetse is statisties beduidende verskille gevind ten opsigte van die volgende veranderlikes waarvolgens groot organisasies meer gunstig vertoon: 1 meer keuringstegnieke word gebruik; 2 die doeltreffendheid van die keurings-programme is hoër; 3 meer opleidingstegnieke word gebruik; 4 opleidingsprogramme is meer doeltreffend; 5 werkers is meer tevrede; 6 werkers se gemiddelde beroepsaanpassing is beter, en 7 werkers is meer tevrede met hul salarisse of lone. Geen betekenisvolle verskille is egter gevind ten opsigte van arbeidsomset, werkafwesigheid en werkbehoeftes nie.

09 Van Coller 03.pmd

African Journals Online (AJOL)

Owner

29 Jul 2010 ... strangeness, awakening in it a drama whose actors are all those assumptions and operations which make the text the work of another period”. Die spore van Raka: Oor herskrywing en kanonisering. (Deel 2). H.P. van Coller en A. van Jaarsveld. H. P. van Coller is hoof van die Departement. Afrikaans ...

Het dichtwerk van Jan van Foreest (1585-1651)

NARCIS (Netherlands)

Vries, M. de

2007-01-01

The dissertation consists of an edition of Jan van Foreest's Greek poems and the greater part of those written in Latin, provided with translations and a succinct commentary in Dutch. A number of the Latin poems appears in print for the first time ever. Jan van Foreest (1586-1651) studied arts at

De miskenning van Theo van Doesburg; zijn bijdrage tot de ontwikkeling van de konkrete poëzie

Directory of Open Access Journals (Sweden)

J. van der Elst

1987-05-01

Full Text Available More literary critics outside Belgium and the Netherlands have written about Theo van Doesburg than from inside these countries. The first important monograph on him appeared in English - Theo van Doesburg - Propagandist and Practitioner of the Avant-Garde, 1909-1923, by Hannah Hedrick. Van Doesburg’s poetry developed in the direction of concrete poetry - the type of poetry in which the spatial, acoustic and visual characteristics of language are maximally utilized towards the creation of the poem. Word as sound and as image is foregrounded in concrete poetry, while the imaging of persons and subjective experience is eliminated as far as possible. The anecdotal or the epic component of the concrete poem is minimal and the language of this sort of poem has been reduced to the minimum. In the spirit of the theory of concrete poetry Van Doesburg advocates the liberation of art from all the commitments imposed upon it. That with which Van Doesburg began was continued by other poets, especially in Germanic literature by poets of the so-called neo-realism.

Effect minerale samenstelling van bodem en plant op de expressie van bladnecrose bij Freesia

NARCIS (Netherlands)

Doorduin, J.C.; Bos, van den A.L.

2003-01-01

Freesiatelers veronderstellen een relatie tussen de voedingstoestand in de grond, de minerale samenstelling van de plant en de expressie van bladnecrose bij freesia. Op verzoek van de Landelijke Freesiacommissie van LTO is een inventarisatie uitgevoerd op ‘gezonde’ en ‘necrose’ bedrijven naar de

Lysine analoga; bereiding en enzymatische hydrolyse van peptide derivaten van lysine en lysine analoga

NARCIS (Netherlands)

Tesser, Godefridus Ignatius

1961-01-01

De synthese van enkele structuuranaloga van lysine wordt beschreven. Aangetoond wordt dat zij lysine in substraten voor trypsine, cathepsine B en papaine kan vervangen. Daar de structuur van de analoga O-(Beta-aminoaethyl)serine en S-(Beta-aminoaethyl) cysteine die van lysine dicht nadert, wordt

Verspreiding en habitats van Bulinus tropicus, tussengasheerslak van die peervormige bot Calicophoron microbothrium, in Suid-Afrika

Directory of Open Access Journals (Sweden)

K. N. de Kock

2002-09-01

Full Text Available Hierdie artikel fokus op die geografiese verspreiding en habitats van Bulinus tropicus, die slaktussengasheer van die peervormige bot, Calicophoron microbothrium. Bulinus tropicus is die varswaterslakspesie met verreweg die wydste geografiese verspreiding, soos gereflekteer deur die vindplekke van die 7 992 monsters wat tans in die databasis van die Nasionale Varswaterslakversameling (NVV van Suid-Afrika op rekord is. Die voorkoms van hierdie spesie is deur versamelaars in ’n totaal van 14 waterliggaamtipes opgeteken, maar die grootste getal monsters is in damme en spruite en in habitats waarvan die water as staande, helder en vars beskryf is, versamel. Die effekgrootte van elke veranderlike is afsonderlik bereken om die rol daarvan in die bepaling van die verspreiding van hierdie spesie vas te stel. Die data in die databasis is verder verwerk en aangepas om ’n geïntegreerde besluitnemingsboom saam te stel. Dit is ’n statistiese model waarvolgens ’n seleksie van veranderlikes gemaak kan word wat maksimaal kan diskrimineer tussen die voorkomsfrekwensie van ’n gegewe spesie en die res van die spesies in die databasis. Die sukses van B. tropicus soos gereflekteer deur sy omvangryke geografiese verspreiding, is waarskynlik toe te skryf aan die omstandigheid dat hierdie spesie grootliks r-geselekteerd is soos onteenseglik in bevolkingsdinamikastudies deur verskeie outeurs bevind is. Daarbenewens beskik die spesie oor’n besondere vermoë om opdroging van ’n habitat vir relatief lang tydperke te kan oorleef. Dit kom egter voor asof sy beperkte verdraagsaamheid ten opsigte van water met ’n relatief lae geleidingsvermoë, moontlik as ’n beperkende faktor vir sy besetting van bepaalde gebiede in Suid-Afrika mag optree. As tussengasheer vir C. microbothrium, wat paramphistomose by vee veroorsaak en soms tot groot verliese kan lei, het die wye verspreiding van B. tropicus in Suid-Afrika egter ook ekonomiese implikasies, veral vir inwoners

DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009-2016

Science.gov (United States)

Berger, Thomas; Burmeister, Sönke; Matthiä, Daniel; Przybyla, Bartos; Reitz, Günther; Bilski, Pawel; Hajek, Michael; Sihver, Lembit; Szabo, Julianna; Ambrozova, Iva; Vanhavere, Filip; Gaza, Ramona; Semones, Edward; Yukihara, Eduardo G.; Benton, Eric R.; Uchihori, Yukio; Kodaira, Satoshi; Kitamura, Hisashi; Boehme, Matthias

2017-03-01

The natural radiation environment in Low Earth Orbit (LEO) differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR), as well as of protons and electrons trapped in the Earth's radiation belts (Van Allen belts). Protons and some heavier particles ejected in occasional Solar Particle Events (SPEs) might in addition contribute to the radiation exposure in LEO. All sources of radiation are modulated by the solar cycle. During solar maximum conditions SPEs occur more frequently with higher particle intensities. Since the radiation exposure in LEO exceeds exposure limits for radiation workers on Earth, the radiation exposure in space has been recognized as a main health concern for humans in space missions from the beginning of the space age on. Monitoring of the radiation environment is therefore an inevitable task in human spaceflight. Since mission profiles are always different and each spacecraft provides different shielding distributions, modifying the radiation environment measurements needs to be done for each mission. The experiments "Dose Distribution within the ISS (DOSIS)" (2009-2011) and "Dose Distribution within the ISS 3D (DOSIS 3D)" (2012-onwards) onboard the Columbus Laboratory of the International Space Station (ISS) use a detector suite consisting of two silicon detector telescopes (DOSimetry TELescope = DOSTEL) and passive radiation detector packages (PDP) and are designed for the determination of the temporal and spatial variation of the radiation environment. With the DOSTEL instruments' changes of the radiation composition and the related exposure levels in dependence of the solar cycle, the altitude of the ISS and the influence of attitude changes of the ISS during Space Shuttle dockings inside the Columbus Laboratory have been monitored. The absorbed doses measured at the end of May 2016 reached up to 286 �

Inventarisatie van mogelijke effecten van kribverlaging in de Waal op de beroepsvisserij

NARCIS (Netherlands)

Winter, H.V.

2011-01-01

Om de hoogwaterveiligheid van het rivierengebied te vergroten is het doel van Rijkswaterstaat om eind 2015 ca. 500 kribben in de Waal verlaagd te hebben en daarnaast langsdammen aangelegd te hebben tussen Wamel en Ophemert. In deze korte deskstudie wordt een inventarisatie gemaakt van mogelijke

Beheersing en bestrijding van Botrytis cinerea en van Penicillium in Euphorbia fulgens

NARCIS (Netherlands)

Wubben, J.P.; Hazendonk, A.; Bosker, I.; Slootweg, C.; Hoope, ten M.

2002-01-01

De bloeiwijze van Euphorbia fulgens kent twee belangrijke schimmelbelagers, die problemen in de teelt veroorzaken: Botrytis cinerea en Penicillium. B. cinerea geeft schade in de vorm van smet of pokken, die op de bloemblaadjes verschijnen. Dit zijn kleine donkerbruine/zwarte plekjes van ongeveer 1

Modellering van begrazing in SUMO : verbetering van de vegetatiemodellering in de Natuurplanner

NARCIS (Netherlands)

Wamelink, G.W.W.; Wegman, R.M.A.; Slim, P.A.; Dirksen, J.; Mol-Dijkstra, J.P.; Dobben, van H.F.

2001-01-01

In samenwerking met het RIVM en WU wordt het vegetatievoorspellingsmodel SUMO ontwikkeld. Het model vormt een integraal onderdeel met SMART en wordt onder andere gebruikt in de natuurplanner van het RIVM. Om de modellering van de effecten van begrazing op de vegetatieontwikkeling en successie

Kwaliteitsdocument inzake de bepaling van Cadmium in kunststoffen met behulp van Rontgenflurescentie

NARCIS (Netherlands)

Hoogerbrugge R; van de Wiel HJ; van de Beek ACW; Kliest JJG; IEM

1999-01-01

Bij de handhaving van het besluit Cadmium in Kunststoffen is gebleken, dat de analyse met behulp van Rvntgenfluorescentie (XRF) een snel en goedkoop alternatief zou kunnen zijn voor de op dit moment wettelijk voorgeschreven methoden. In opdracht van de Inspecteur Milieuhygikne is daarom door het

De morbiditeit van astma en COPD in Nederland; een inventariserend onderzoek ten behoeve van de beleidsondersteuning van het Nederlands Astma Fonds

NARCIS (Netherlands)

Smit HA; Beaumont M; CZE

2000-01-01

In opdracht van het Nederlands Astma Fonds is een inventarisatie gemaakt van beschikbare kennis over de morbiditeit van astma en COPD in Nederland. De volgende vraagstellingen werden geformuleerd: Inventarisatie: welke gegevensbronnen zijn beschikbaar, welke gegevens zijn daarin aanwezig? In

’n Evaluering van die welstand onder werknemers van ’n mediesefondsmaatskappy in Suid-Afrika

Directory of Open Access Journals (Sweden)

Lee-Anne Naicker

2015-02-01

Full Text Available Huidige navorsing op die gebied van welstand in die werkplek is gefragmenteer en vereis ’n holistiese, geïntegreerde en stelselmatige begrip van werknemerwelstand sodat gesondheiden welstandsorg doeltreffend bestuur kan word. Die toenemende las van nie-oordraagbare toestande in Suid-Afrika beklemtoon die noodsaaklikheid van voorkomingstrategieë soos welstandprogramme. Die werkomgewing bied ’n ideale plek, aangesien ’n groot deel van die bevolking geteiken word, insluitende diegene wie se lewenstyl verbeter moet word. Hierdie studie is dus daarop gemik om verskeie gesondheid- en welstandkomponente onder werknemers van ’n mediesefondsmaatskappy te evalueer in ’n poging om risikogebiede te identifiseer wat verdere ingryping vereis. Die deelnemers het bestaan uit 140 werknemers van ’n mediesefondsmaatskappy wat ten minste 40 h per week werk. Hulle is onderwerp aan ’n welstandassesseringsbattery bestaande uit antropometrieke, gesondheidverwante en fisieke kapasiteitmetings. Die resultate toon dat ingryping nodig is betreffende alkohol- en dwelmgebruik, dieetgewoontes, hartgesondheid, liggaamsamestelling, spieruithouvermoë, kardiorespiratoriese uithouvermoë en individuele persepsies van die maatskappy. Dié studie het resultate opgelewer wat die bevindings van baie vorige navorsing op hierdie gebied staaf. Die trefwydte van welstandprogramme op die Suid-Afrikaanse bevolking is egter beperk. Die sukses van welstandprogramme wat fisieke aktiwiteit beklemtoon, is goed gedokumenteer in hoë-inkomstelande, met bewys van die ekonomiese voordele en opbrengs op belegging. Gevolglik word daar aangevoer dat die toepassing van welstandprogramme ’n positiewe uitwerking op die Suid-Afrikaanse werkmag sal hê.

Praktijkkennis van leerkrachten als ontwerpers van een ICT rijke leeromgeving

NARCIS (Netherlands)

Boschman, Ferry; McKenney, Susan; Voogt, Joke

2011-01-01

Ormel, B., Pareja, N., & McKenney, S. (2011, 8-10 June). Praktijkkennis van leerkrachten als ontwerpers van een ICT rijke leeromgeving. Presentation at the ORD annual meeting, Maastricht, The Netherlands.

Mogelijkheden tot productie van beertjes

NARCIS (Netherlands)

Scholten, R.; Huiskes, J.

1994-01-01

In opdracht van het Produktschap Vee en Vlees is het project Mogelijkheden tot productie van vleesbeertjes en afzet van vlees en vleesproducten hiervan uitgevoerd. De afzetmogelijkheden voor vlees van beertjes zijn en blijven vooralsnog minimaal

Rate Coefficients of the Reaction of OH with Allene and Propyne at High Temperatures

KAUST Repository

Es-sebbar, Et-touhami

2016-09-28

Allene (H2C═C═CH2; a-C3H4) and propyne (CH3C≡CH; p-C3H4) are important species in various chemical environments. In combustion processes, the reactions of hydroxyl radicals with a-C3H4 and p-C3H4 are critical in the overall fuel oxidation system. In this work, rate coefficients of OH radicals with allene (OH + H2C═C═CH2 → products) and propyne (OH + CH3C≡CH → products) were measured behind reflected shock waves over the temperature range of 843–1352 K and pressures near 1.5 atm. Hydroxyl radicals were generated by rapid thermal decomposition of tert-butyl hydroperoxide ((CH3)3–CO–OH), and monitored by narrow line width laser absorption of the well-characterized R1(5) electronic transition of the OH A–X (0,0) electronic system near 306.7 nm. Results show that allene reacts faster with OH radicals than propyne over the temperature range of this study. Measured rate coefficients can be expressed in Arrhenius form as follows: kallene+OH(T) = 8.51(±0.03) × 10–22T3.05 exp(2215(±3)/T), T = 843–1352 K; kpropyne+OH(T) = 1.30(±0.07) × 10–21T3.01 exp(1140(±6)/T), T = 846–1335 K.

2012, 11/01807, (Vrijstellingsmethode niet van toepassing op Amerikaans deel van bestuurdersbeloning)

NARCIS (Netherlands)

D. Molenaar (Dick)

2012-01-01

textabstractSamenvatting: Belanghebbende is met ingang van 1 februari 2004 werkzaam als CEO bij C en vanaf 31 december 2003 als statutair bestuurder van de Amerikaanse werkmaatschappij van C. Eind 2004 heeft belanghebbende een additioneel belang in C verworven. Het verschil tussen de waarde in het

Van graf tot wieg ; de rol van fintech door de generaties heen

NARCIS (Netherlands)

Vries, A. de; Bakas, A.

2015-01-01

Als financiële dienstverlener moet je rekening houden met mensen van alle leeftijden en uit alle lagen van de bevolking. Van de hulpbehoevende senior tot de nieuwsgierige kleuter. We vroegen 2 experts wat verschillende levensfasen typeert, hoe deze persona’s tegen technologie aankijken en hoe

Isomerization of Internal Alkynes to Iridium(III Allene Complexes via C–H Bond Activation: Expanded Substrate Scope, and Progress towards a Catalytic Methodology

Directory of Open Access Journals (Sweden)

Neha Phadke

2015-11-01

Full Text Available The synthesis of a series of allene complexes (POCOPIr(η2-RC=.=CR’ 1b–4b (POCOP = 2,6-bis(di-tert-butylphosphonitobenzene via isomerization of internal alkynes is reported. We have demonstrated that the application of this methodology is viable for the isomerization of a wide variety of alkyne substrates. Deuterium labeling experiments support our proposed mechanism. The structures of the allene complexes 1b–4b were determined using spectroscopic data analysis. Additionally, the solid-state molecular structure of complex 2b was determined using single crystal X-ray diffraction studies and it confirmed the assignment of an iridium-bound allene isomerization product. The rates of isomerization were measured using NMR techniques over a range of temperatures to allow determination of thermodynamic parameters. Finally, we report a preliminary step towards developing a catalytic methodology; the allene may be liberated from the metal center by exposure of the complex to an atmosphere of carbon monoxide.

De fysica van polymere materialen

NARCIS (Netherlands)

Struik, L.C.E.

1987-01-01

Rede, uitgesproken ter gelegenheid van de aanvaarding van het ambt van buitengewoon hoogleraar in de fysica van polymere materialen aan de Universitelt Twente op donderdag 22 januarì 1987 door Dr.lr. L.C.E. Struik.

Die histologie en ultrastruktuur van die hepatopankreas van die bloukurper Oreochromis mossambicus

Directory of Open Access Journals (Sweden)

M. M. Nel

1990-07-01

Full Text Available Die histologie en ultrastruktuur van die hepatopankreas van die bloukurper Oreochromis mossambicus word beskryf. ’n Dun bindweefselkapsel omring die lewer. Die hepatosietrangskikking vertoon as lobules, met die koorde van hepatosiete wat vanaf ’n sentrale vene uitradieer en met mekaar anastomaseer. Indiwiduele lewerlohules vertoon nie duidelike grense nie, maar enkele duidelike triades word wel in die lewer van O. mossambicus aangetref. Die hepatosiete bevat ’n enkele ronde kern met ’n duidelike nukleolus en die growwe endoplasmiese retikula kom in twee of meer rye om die kerne en teen die selgrense van die hepatosiete voor. Die ander sitoplasmiese organelle kom verspreid in die hepatosietsitoplasma voor. Die eksokriene pankreasselle is om die portale venes gesetel. Die kerne van hierdie selle is rond en is hasaal in die kubies- tot silindervormige selle gelee. ’n Goedontwikkelde growwe endoplasmiese retikulum — vesikulêr, tubulêr en sirkulêr in vorm — en sektretoriese granules wat apikaal in die sel gelee is, kom voor.

Verspreiding van zout bij het terugwinnen van zeezand uit een depot in het Haringvliet

NARCIS (Netherlands)

Kranenburg, C.

1991-01-01

Dit rapport geeft een beknopte analyse van de verdunning en verspreiding van zout vanuit een gepland depot voor ontzilt zeezand in het Haringvliet. Beschouwd zijn de initiële menging van het zout bij terugwinnen van het zand, de verspreiding door stroming en turbulentie bij geopende spuisluis, en de

Van strafbaar tot huwbaar : homorecht wereldwijd (presentatie op Ministerie van Buitenlandse Zaken, Den Haag)

NARCIS (Netherlands)

Waaldijk, C.

2015-01-01

Met de door hem ontwikkelde Global Index on Legal Recognition of Homosexual Orientation (GILRHO) geeft Kees Waaldijk op een schaal van nul tot acht aan, hoe ver een land is met het uit het strafrecht halen van homoseksualiteit, met het verbieden van homodiscriminatie en met het erkennen van

Voorkoming en beheersing van gebreksverschijnselen in de bloembollenteelt : teelt en afbroeiproeven met als doel het voorkomen van ijzergebrek bij tulpen, hyacinten en narcissen van mangaangebrek bij tulpen en van vervroegde afsterving bij lelies

NARCIS (Netherlands)

Dam, van A.M.; Dam, van M.F.N.; Bruin, P.N.A.

2004-01-01

Door veranderingen in de teelten en de aanscherping van het overheidsbeleid t.a.v. het gebruik van met name dierlijke mest kunnen zich bij de teelt van bloembollen verschijnselen voordoen die mogelijk samenhangen met een gebreksituatie. PPO heeft in dit project een aantal van deze verschijnselen

Uw ziekteperceptie is de mijne niet! : DSM-5 over de Somatische Symptoom Aandoening (SSD)

NARCIS (Netherlands)

Drs. Rob Arnoldus

2013-01-01

Worden we met z’n allen steeds gekker? In DSM-5, de nieuwe versie van het handboek van de American Psychiatric Association (APA), maken we kennis met een reeks nieuwe, weinig afgebakende stoornissen. Een daarvan is de Somatische Symptoom Aandoening (SSD). Met dit nieuwe label ligt slodderdiagnostiek

Kosten van allogene stamceltransplantaties

NARCIS (Netherlands)

M. van Agthoven (Michel); M.T. Groot (Martijn); C.A. Uyl-de Groot (Carin)

2001-01-01

textabstractAllogene stamceltransplantatie is een topspecialistische procedure die met succes kan worden ingezet in de behandeling van (hematologische) maligniteiten, met name bij leukemie. Van oudsher worden transplantaten van verwante donoren gebruikt, maar met de mogelijkheden om transplantaten

Contra-expertise op bepalingen van radioactiviteit van afvalwater en ventilatielucht van de kernenergiecentrale Borssele. Periode 2008

NARCIS (Netherlands)

Kwakman PJM; Overwater RMW; LSO

2012-01-01

Dit rapport is eerder vertrouwelijk uitgebracht als briefrapport 610330093. Dit is besproken met de VROM-opdrachtgever en vertegenwoordigers van de betreffende nucleaire installatie: het commentaar op het rapport is verwerkt, voorzien van een Rapport in het Kort, en mag openbaar worden als RIVM

Contra-expertise op bepalingen van radioactiviteit van afvalwater en ventilatielucht van de kernenergiecentrale Borssele. Periode 2009

NARCIS (Netherlands)

Kwakman PJM; Overwater RMW; LSO

2012-01-01

Dit rapport is eerder vertrouwelijk uitgebracht als briefrapport 610330103. Dit is besproken met de VROM-opdrachtgever en vertegenwoordigers van de betreffende nucleaire installatie: het commentaar op het rapport is verwerkt, voorzien van een Rapport in het Kort, en mag openbaar worden als RIVM

Contra-expertise op bepalingen van radioactiviteit van afvalwater en ventilatielucht van de kernenergiecentrale Borssele. Periode 2007

NARCIS (Netherlands)

Kwakman PJM; Overwater RMW; LSO

2012-01-01

Dit rapport is eerder vertrouwelijk uitgebracht als briefrapport 610330076. Dit is besproken met de VROM-opdrachtgever en vertegenwoordigers van de betreffende nucleaire installatie: het commentaar op het rapport is verwerkt, voorzien van een Rapport in het Kort, en mag openbaar worden als RIVM

Resultaten van het RWS-RIKZ JAMP 2003 monitoringsprogramma van bot (Platychthys flesus L.). Biologische gegevens van bot en milieukritische stoffen in bot en mosselen

NARCIS (Netherlands)

Kotterman, M.J.J.

2004-01-01

In opdracht van RWS-RIKZ werden door het RIVO werkzaamheden uitgevoerd in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De werkzaamheden bestonden uit het verzamelen van monsters bot waarvan biologische parameters werden bepaald. Tevens werden milieukritische stoffen

Resultaten van het RWS-RIKZ JAMP 2004 monitoringsprogramma van bot (Platichthys flesus L.). Biologische gegevens van bot en milieukritische stoffen in bot en mosselen

NARCIS (Netherlands)

Kotterman, M.J.J.

2005-01-01

In opdracht van RWS-RIKZ werden door het RIVO werkzaamheden uitgevoerd in het kader van het Joint Assessment and Monitoring Program van de OSPARCOM. De werkzaamheden bestonden uit het verzamelen van monsters bot waarvan biologische parameters werden bepaald. Tevens werden milieukritische stoffen

Mathematics and Humor: John Allen Paulos and the Numeracy Crusade

OpenAIRE

Paul H. Grawe

2015-01-01

John Allen Paulos at minimum gave the Numeracy movement a name through his book Innumeracy: Mathematical Illiteracy and Its Consequences. What may not be so obvious was Paulos’ strong interest in the relationship between mathematics and mathematicians on the one hand and humor and stand-up-comedian joke structures on the other. Innumeracy itself could be seen as a typically mathematical Gotcha joke on American culture generally. In this perspective, a Minnesotan acculturated to Minnesota-Nice...

‘Op de wijze van Kavafis’: Die voorbeeld van die digter uit Alexandrië

Directory of Open Access Journals (Sweden)

Phil van Schalkwyk

2014-12-01

Full Text Available Die Griekse digter K.P. Kavafis (1863–1933 word wêreldwyd deur lesers sowel as skrywers besonder hoog geag. Hy het nie net van die grootste twintigste-eeuse skrywers beïnvloed nie,maar is vanweë die buitengewone vertaalbaarheid van sy werk ook betreklik sterk teenwoordig in die letterkunde van meer tale as slegs Grieks en Engels. Vir baie – veral gay lesers, skrywers en kunstenaars – besit Kavafis ’n voorbeeldstatus, ten opsigte van die letterkunde sowel asdie lewe. W.H. Auden het beweer dat dit wat Kavafis onderskei, sy stemtoon is, een wat ’n persoon met ’n unieke perspektief op die wêreld openbaar. Hierdie bydrae, wat deel is van ’nnavorsingsprojek oor idiolektiese skrywersidentiteit, is daarop gerig om die onderskeidende kenmerke van Kavafis se werk, sowel in terme van vorm as inhoud, opnuut te ondersoek. Dit word gedoen binne die raamwerk van die breë kritiese diskoers oor Kavafis en met verwysing na enkele manifestasies/voorbeelde van Nederlandse en Afrikaanse kritiese en kreatieweperspektiewe op sy poësie, met die doel om spesifiek lig te werp op die besondere soortwysheid wat in Kavafis se werk oorgedra word.

Stabilisatie en samenstelling van het glycosidenmengsel van Folia digitalis

NARCIS (Netherlands)

Tattje, Derk Hendrik Evert

1952-01-01

Na een korte inleiding wordt een omschrijving van het begrip stabilisatie gegeven en besproken hoe deze stabilisatie, dit is het irreversibel inactiveren van de enzymen, in het algemeen tot stand kan worden gebracht. Tevens wordt nagegaan of ook door verschillende oplosmiddelen reeds bij gewone

Controle van spectrofotometers in ziekenhuislaboratoria

NARCIS (Netherlands)

Ham; W.A.van den; Steentjes; G.M.; Buitenhuis; S.G.; Terlingen; J.B.A.

1985-01-01

In dit rapport worden de resultaten beschreven van een onderzoek dat door twee medewerkers van het Laboratorium voor Klinische Chemie en Hematologie werd ingesteld naar de toestand van 22 fotometers in ziekenhuislaboratoria. Onderzocht werden: - juistheid van de golflengte-instelling - juistheid

Ingredienten voor kwaliteitsborging van modelonderzoek

NARCIS (Netherlands)

Grinsven JJM van; Haan BJ de; Braat LC; MNV; LBG; CIM

1995-01-01

In dit rapport wordt een aanzet gepresenteerd tot harmonisatie van de kwaliteitsborging van modelonderzoek in het RIVM. Het rapport komt voort uit initiatieven van leden van het Intersectoraal Modellen Overleg. Het rapport is in eerste instantie bedoeld voor onderzoekers die modellen

Die meting van sistematiese tydorientasie as 'n sielkundige konstruk van Beroepsgedrag

Directory of Open Access Journals (Sweden)

J. I. De Jager

1985-11-01

Met hierdie navorsing is gepoog om 'n persoonsbeeld van 'n individu met ‘n sistematiese tydoriëntasiestyl saam te stel, en om 'n verfynde instrument vir die meting van sistematiese tydoriëntasie te ontwikkel. Resultate toon dat die vraelys wel 'n bevredigende interne bestendigheid het en ook as ‘n verfynde instrument vir die meting van sistematiese tydoriëntasie beskou kan word.

DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009–2016

Directory of Open Access Journals (Sweden)

Berger Thomas

2017-01-01

Full Text Available The natural radiation environment in Low Earth Orbit (LEO differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR, as well as of protons and electrons trapped in the Earth’s radiation belts (Van Allen belts. Protons and some heavier particles ejected in occasional Solar Particle Events (SPEs might in addition contribute to the radiation exposure in LEO. All sources of radiation are modulated by the solar cycle. During solar maximum conditions SPEs occur more frequently with higher particle intensities. Since the radiation exposure in LEO exceeds exposure limits for radiation workers on Earth, the radiation exposure in space has been recognized as a main health concern for humans in space missions from the beginning of the space age on. Monitoring of the radiation environment is therefore an inevitable task in human spaceflight. Since mission profiles are always different and each spacecraft provides different shielding distributions, modifying the radiation environment measurements needs to be done for each mission. The experiments “Dose Distribution within the ISS (DOSIS” (2009–2011 and “Dose Distribution within the ISS 3D (DOSIS 3D” (2012–onwards onboard the Columbus Laboratory of the International Space Station (ISS use a detector suite consisting of two silicon detector telescopes (DOSimetry TELescope = DOSTEL and passive radiation detector packages (PDP and are designed for the determination of the temporal and spatial variation of the radiation environment. With the DOSTEL instruments’ changes of the radiation composition and the related exposure levels in dependence of the solar cycle, the altitude of the ISS and the influence of attitude changes of the ISS during Space Shuttle dockings inside the Columbus Laboratory have been monitored. The absorbed doses measured at the end of May 2016

Well-posedness for one-dimensional anisotropic Cahn-Hilliard and Allen-Cahn systems

Directory of Open Access Journals (Sweden)

Ahmad Makki

2015-01-01

Full Text Available Our aim is to prove the existence and uniqueness of solutions for one-dimensional Cahn-Hilliard and Allen-Cahn type equations based on a modification of the Ginzburg-Landau free energy proposed in [8]. In particular, the free energy contains an additional term called Willmore regularization and takes into account strong anisotropy effects.

Ontwikkeling van een protocol voor de transformatie van iris; introductie van resistentie tegen irismozaik viris (IMMV)

NARCIS (Netherlands)

Langeveld, S.A.; Klerk, de G.J.M.

2004-01-01

Twee iris cultivars, Blue Magic en Blue Sail, werden in weefselkweek gebracht en callus werd geïnduceerd. Dit callus werd genetisch gemodificeerd met virusresistentie via de particle gun procedure die eerder voor lelie was ontwikkeld. Van een van de cultivars, Blue Magic, werden getransformeerde

Effects of island seabird subsidies and invasive species dynamics on the body size and foraging ecology of the Allen Cays Rock Iguana (Cyclura cychlura inornata)

OpenAIRE

Richardson, Kristen Mundie

2015-01-01

Island systems have long been valuable to ecological research as they provide natural experiments for the study of ecosystem processes. We examined Allen, Leaf, U and Flat Rock Reef Cays in the Bahamas to study the effects of seabird driven marine subsidies and invasive mice on island food webs on the body size and foraging ecology of the Allen Cays Rock Iguana (Cyclura cychlura inornata). Iguanas on an island with nesting seabirds (Allen Cay) had 6 times the body mass and 1.7 times the snout...

Plaatsen van beschaafd vertier

Directory of Open Access Journals (Sweden)

James Kennedy

2014-09-01

Full Text Available Plaatsen van beschaafd vertier [Places of civilised amusement] by Jan Hein Furnée, which appeared as a PhD thesis in 2007 and was adapted and extended into a book in 2012, is regarded by historians of the Low Countries as an impressive tour de force. In a stimulating manner Furnée demonstrates with this profound urban history that for the elite of The Hague leisure activities played an important role in acquiring status and maintaining their position. His study is based on extensive and systematic research into a great variety of sources, from census registers, membership lists of clubs and societies to address books. This gives the reader an extraordinarily detailed picture of the changing social relations in the upper echelons of society in The Hague in the latter half of the nineteenth century. The sophisticated use of both qualitative and quantitative methods can serve as a model for other historians in the field of urban history. In a lively fashion Furnée shows that the inhabitants of The Hague grasped at all kinds of pastimes in order to distinguish themselves from others, and when possible to increase their own status through their participation in elegant societies, theatre visits or supporting the proposed zoo: but the book also makes statements about status and class, the history of gender and of politics at the end of the nineteenth century. Plaatsen van beschaafd vertier van Jan Hein Furnée dat in 2007 als proefschrift en in 2012 bewerkt en uitgebreid als boek verscheen, staat onder historici van de Lage Landen bekend als een imponerende tour de force. Op prikkelende wijze laat Furnée in deze diepgravende stadsgeschiedenis zien dat vrijetijdsbesteding voor Haagse elites een belangrijke rol speelde in standsvorming en handhaving van hun positie. Zijn studie is gebaseerd op uitgebreid en systematisch onderzoek van veelsoortige bronnen, van volkstellingsregisters, ledenlijsten van verenigingen en sociëteiten tot adresboeken

Van wie zijn zij? De ambtenaren

NARCIS (Netherlands)

Peters, Jit

2011-01-01

Aan de hand van actuele voorbeelden gaat Jit Peters tijdens zijn afscheidscollege in op de toegenomen macht van ambtenaren. De loyaliteit van de ambtenaar is volgens hem nu te veel gericht op het ondersteunen van de eigen minister. Als tegenwichten van de macht van de ambtenaar staat Peters stil bij

Microbewerking met behulp van lasers

NARCIS (Netherlands)

Ezendam, M.M.M.

1994-01-01

Het bewerken van materialen met behulp van lasers staat momenteel enorm in de belangstelling, en terecht. De ontwikkeling van bestaande en nieuwe typen lasers staat alles behalve stil. Ontwikkelingen bevinden zich met name in het gebied van hogere vermogens, betere bundelkwaliteit en hogere

Characteristics of pitch angle distributions of hundreds of keV electrons in the slot region and inner radiation belt

Science.gov (United States)

Zhao, H.; Li, X.; Blake, J. B.; Fennell, J. F.; Claudepierre, S. G.; Baker, D. N.; Jaynes, A. N.; Malaspina, D. M.

2014-12-01

The pitch angle distribution (PAD) of energetic electrons in the slot region and inner radiation belt received little attention in the past decades due to the lack of quality measurements. Using the state-of-the-art pitch angle-resolved data from the Magnetic Electron Ion Spectrometer instrument onboard the Van Allen Probes, a detailed analysis of hundreds of keV electron PADs below L = 4 is performed, in which the PADs are categorized into three types: normal (flux peaking at 90°), cap (exceedingly peaking narrowly around 90°), and 90° minimum (lower flux at 90°) PADs. By examining the characteristics of the PADs of ˜460 keV electrons for over a year, we find that the 90° minimum PADs are generally present in the inner belt (Lpitch angle scattering of hiss waves. Fitting the normal PADs into sinnα form, the parameter n is much higher below L = 3 than that in the outer belt and relatively constant in the inner belt but changes significantly in the slot region (2 mechanism can hardly explain the formation of 90° minimum PADs at the center of inner belt.

Thijs van Vugt, Een arbeidersbuurt onder de rook van ‘De Sphinx’. Eeen sociaal-ruimtelijke geschiedenis van het Boschstraatkwartier-Oost te Maastricht, 1829-1904

Directory of Open Access Journals (Sweden)

Christianne Smit

2015-12-01

Full Text Available Thijs van Vugt, Een arbeidersbuurt onder de rook van ‘De Sphinx’. Een sociaal-ruimtelijke geschiedenis van het Boschstraatkwartier-Oost te Maastricht, 1829-1904 (Dissertatie Universiteit van Maastricht 2015; Maaslandse Monografieën 78; Hilversum: Verloren, 2015, 228 pp., isbn 978 90 8704 493 0.

De Smartcard van 2010

NARCIS (Netherlands)

Hartel, Pieter H.; Jacobs, Bart

2001-01-01

Aan de universiteiten van Twente en Nijmegen zijn twee onderzoeksgroepen onder leiding van de auteurs intensief bezig met smartcards. Beide auteurs zijn eerder dit jaar betrokken geweest bij het opstellen van de nieuwe Europese onderzoeksagenda voor smartcards, binnen het zogenaamde zesde kader

Lichtdoorlatendheid van kasdekken onder verschillende omstsndigheden

NARCIS (Netherlands)

Bot, G.P.A.

1984-01-01

Aandacht voor lichtonderschepping; bewolkingsgraad; direkte straling; diffuse straling en gevolgen van veranderingen in kaskonstruktie of materiaaleigenschappen ten aanzien van de lichtdoorlatendheid. Bij vergelijking van de lichttransmissie van diverse kasdekken dient te worden uitgegaan van

Vloeistof-vloeistof verdeling als onderzoekmethode bij de vergelijking van enige rassen van digitalis purpurea L.

NARCIS (Netherlands)

Henning, Gerardus Johannes

1962-01-01

De samenstelling van het glycosidenmengsel van drie rassen van Digitalis purpura L. werd in verschillende groeistadia onderzocht. Door extractie met chloroform van een waterige oplossing der in het gefermenteerde blad voorkomende glycosiden werden deze in twee groepen verdeeld, een in chloroform

Algemene principes van palliatieve zorg

NARCIS (Netherlands)

de Graeff, A; Jobse, A.; Teunissen, SCCM; Verkuijlen, S.; Vissers, K.C.P.; Zylicz, Z; Gilsing, M.

2017-01-01

Palliatieve zorg is een benadering die de kwaliteit van leven verbetert van patiënten (kinderen en volwassenen) en hun naasten die te maken hebben met een levensbedreigende aandoening, door het voorkomen en verlichten van lijden door middel van vroegtijdige signalering en zorgvuldige beoordeling en

Burnout : de stand van zaken

NARCIS (Netherlands)

Taris, T.; Houtman, I.L.D.; Schaufeli, W.

2013-01-01

Dit artikel geeft een overzicht van de stand van zaken in het onderzoek naar burnout. Burnout is een syndroom van extreme vermoeidheid (uitputting), afstand nemen van het werk (distantie) en weinig vertrouwen in het eigen kunnen (verminderde competentie), waarbij de oorzaken voor deze aspecten

Bestrijding van duist in wintertarwe

NARCIS (Netherlands)

Timmer, R.D.

2006-01-01

Duist, en speciaal resistente duist, is één van de grootste problemen in het graantelend gebied het Oldambt. De wintertarwegewassen ondervinden sterke concurrentie van de groeiende duistpopulatie, hetgeen ten koste gaat van de opbrengst. De inzet en kosten van de toegepaste herbiciden nemen toe

Die konteks vir die keuse van geriefsvoedsel van bepaalde ...

African Journals Online (AJOL)

Seugnet

70. Die konteks vir die keuse van geriefsvoedsel van bepaalde beroepsvroue *. Martha Kok en Priscilla Botha. ABSTRACT. The purpose of this research is to understand and describe the context in which career women choose, purchase and use convenience food (CF). A person is rarely isolated from or unaffected by.

A Versatile Room-Temperature Route to Di- and Trisubstituted Allenes Using Flow-Generated Diazo Compounds**

Science.gov (United States)

Poh, Jian-Siang; Tran, Duc N; Battilocchio, Claudio; Hawkins, Joel M; Ley, Steven V

2015-01-01

A copper-catalyzed coupling reaction between flow-generated unstabilized diazo compounds and terminal alkynes provides di- and trisubstituted allenes. This extremely mild and rapid transformation is highly tolerant of several functional groups. PMID:26013774

Het presteren van FM

NARCIS (Netherlands)

van der Voordt, D.J.M.

2008-01-01

Prestatieafspraken. Prestatiespecificaties. Prestatiecontracten. Het woord prestatie duikt steeds vaker op in de wereld van FM. Maar wat bedoelen we er nu precies mee? En kunnen we de prestaties van FM wel op een betrouwbare en valide manier meten? Een beschouwing vanuit de wereld van een

Enkele hydrologische aspecten van een bodem- en grondwaterverontreiniging op het fabrieksterrein van Nestle te Rotterdam

NARCIS (Netherlands)

Mulschlegel; J.; Kusse; A.A.M.

1984-01-01

De Regionaal Inspecteur van de Volksgezondheid voor de Milieuhygiene voor Zuid-Holland verzocht RIVM-LBG inzicht te geven in de eventuele verbreiding van een verontreiniging op het fabrieksterrein van Nestle te Rotterdam. Bij het uitgevoerde onderzoek is gebruik gemaakt van een 3-dimensionaal

Performing Allen's test in immobile hand: The Esmarch bandage method

Directory of Open Access Journals (Sweden)

Nebil Yesiloglu

2015-12-01

Full Text Available In this study, an alternative method of assessing hand vascular flow using a modification of Allen's test is presented. This technique may be helpful for patients who have immobile hands due to severe trauma, patients scheduled for free tissue transfer reconstruction, patients under general anesthesia in intensive care units that require serial arterial blood gas analyses, and emergency coronary by-pass candidates who decided to receive radial arterial grafts. [Hand Microsurg 2015; 4(3.000: 83-85

Cyclotron Acceleration of Relativistic Electrons through Landau Resonance with Obliquely Propagating Whistler Mode Chorus Emissions

Science.gov (United States)

Omura, Y.; Hsieh, Y. K.; Foster, J. C.; Erickson, P. J.; Kletzing, C.; Baker, D. N.

2017-12-01

A recent test particle simulation of obliquely propagating whistler mode wave-particle interaction [Hsieh and Omura, 2017] shows that the perpendicular wave electric field can play a significant role in trapping and accelerating relativistic electrons through Landau resonance. A further theoretical and numerical investigation verifies that there occurs nonlinear wave trapping of relativistic electrons by the nonlinear Lorentz force of the perpendicular wave magnetic field. An electron moving with a parallel velocity equal to the parallel phase velocity of an obliquely propagating wave basically see a stationary wave phase. Since the electron position is displaced from its gyrocenter by a distance ρ*sin(φ), where ρ is the gyroradius and φ is the gyrophase, the wave phase is modulated with the gyromotion, and the stationary wave fields as seen by the electron are expanded as series of Bessel functions Jn with phase variations n*φ. The J1 components of the wave electric and magnetic fields rotate in the right-hand direction with the gyrofrequency, and they can be in resonance with the electron undergoing the gyromotion, resulting in effective electron acceleration and pitch angle scattering. We have performed a subpacket analysis of chorus waveforms observed by the Van Allen Probes [Foster et al., 2017], and calculated the energy gain by the cyclotron acceleration through Landau resonance. We compare the efficiencies of accelerations by cyclotron and Landau resonances in typical events of rapid electron acceleration observed by the Van Allen Probes.References:[1] Hsieh, Y.-K., and Y. Omura (2017), Nonlinear dynamics of electrons interacting with oblique whistler mode chorus in the magnetosphere, J. Geophys. Res. Space Physics, 122, 675-694, doi:10.1002/2016JA023255.[2] Foster, J. C., P. J. Erickson, Y. Omura, D. N. Baker, C. A. Kletzing, and S. G. Claudepierre (2017), Van Allen Probes observations of prompt MeV radiation belt electron acceleration in nonlinear

Die bantering van daar-interferensie in die Duits van Afrikaansmoedertaliges

Directory of Open Access Journals (Sweden)

Emerencia C. Steyn

2013-02-01

Full Text Available A comparison of sentence constructions in the soundtracks (simulcast of some television programmes indicates a general lack of a German equivalent for the multiple use of the A.frikaans daar. This naturally results in interference in the usage of German by A.frikaans speaking students, as they are inclined to construct their German sentences in accordance with the A.frikaans equivalents. This problem is mainly illustrated in either the erroneous use of a da or an inappropriate es gibt. Various exercises are submitted, aimed at obviating such errors of interference which are mainly noticeable in the spoken ·language. Soos blyk uit 'n vergelyking van segslryses in die parallelle klankbane van enkele televisieprogramme, het die veelvuldige gebruik van die Afrikaanse woord daar gewoonlik geen ekwivalensie in Duits nie. Dit lei maklik tot interferensie in die Duits van Afrikaansmoedertalige studente, omdat hulle daartoe neig om hul Duitse sinne soos die in A.frikaans te konstrueer. Hierdie probleem word hoofsaaklik in die foutiewe gebruik van da geopenbaar; soms egter ook in 'n misplaaste es gibt. Verskeie oefeninge word aan die hand gedoen om sulke interferensiefoute, wat vera! in m(mdelinge werk opduik, te bekamp.

Beam-dynamic effects at the CMS BRIL van der Meer scans

Science.gov (United States)

Babaev, A.

2018-03-01

The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is responsible for the simulation and measurement of luminosity, beam conditions and radiation fields in the CMS experiment. The project is engaged in operating and developing new detectors (luminometers), adequate for the experimental conditions associated with high values of instantaneous luminosity delivered by the CERN LHC . BRIL operates several detectors based on different physical principles and technologies. Precise and accurate measurements of the delivered luminosity is of paramount importance for the CMS physics program. The absolute calibration of luminosity is achieved by the van der Meer method, which is carried out under specially tailored conditions. This paper presents models used to simulate of beam-dynamic effects arising due to the electromagnetic interaction of colliding bunches. These effects include beam-beam deflection and dynamic-β effect. Both effects are important to luminosity measurements and influence calibration constants at the level of 1-2%. The simulations are carried out based on 2016 CMS van der Meer scan data for proton-proton collisions at a center-of-mass energy of 13 TeV.

Preventie van slaapgebrek en vermoeidheid

NARCIS (Netherlands)

Simons, R; Valk, P.

2006-01-01

Korte schets van de bijdrage aan het Europese Fit-to Fly project ( Early Warning Systems sensoren) van TNO Defensie en Veiligheid en hun eigen onderzoek naar fase-verschuiving van de slaap en strategisch gedoseerde slaapperioden. De eisen die een missie aan het personeel stelt, de verstoring van het

Teelt van hybride wintertarwerassen

NARCIS (Netherlands)

Timmer, R.D.; Paauw, J.G.M.

2003-01-01

Om de mogelijkheden van de teelt van hybride wintertarwerassen onder Nederlandse omstandigheden in beeld te brengen zijn er van 2000-2002 proeven uitgevoerd op het PPO-proefbedrijf te Lelystad. In deze proeven zijn een 4-tal hybriderassen (Hybnos, Hyno-braba, Hyno-esta, Mercury) vergeleken met een

De keuze van Vincent

NARCIS (Netherlands)

Stolwijk, Chris

2003-01-01

Official publication to accompany the important exhibition Vincent's Choice, Van Gogh's 'musee imaginaire' at the Van Gogh Museum, Amsterdam marking the 150th anniversary of the artist's birth.Thanks to van Gogh's correspondence, it has been possible to identify the works he knew and admired. The

The use of solar cells for continuous recording of absorbed dose in the product during radiation sterilization

International Nuclear Information System (INIS)

Moehlmann, J.H.F.

1981-01-01

As a result of the rapidly developing space programme, reliable solar panels were needed as an energy source for space capsules. It was found that when a space capsule passed through the Van Allen Belt, the solar panels aged owing to the radiation, and the energy output declined. The United States National Aeronautics and Space Administration investigated the pre-irradiation of solar panels and found that they withstood high doses, such as 20 Mrad, the panels having aged and the energy output having become lower but steady. The response of the solar cells to high levels of radiation caused Gammaster to attempt to use this effect to serve as a check on the operating status of its large 60 Co gamma irradiation facility. During γ-irradiation a potential is generated in a p-n silicon solar cell which can be made to drive ancillary equipment. For example, the current from the solar cell can be fed to a pen recorder to assist in process control. The pen recorder can, for example, also act as an automatic logbook by recording the irradiation times. The sensitivity of a cell is such that changes in absorption between homogeneously and inhomogeneously filled containers are clearly shown on the recorder sheets. All source movements are visible, and the timer setting and the number of containers treated, etc. can be monitored. Such a system provides a reliable additional process control at low cost and requests little maintenance. (author)

‘Anders slapen’. Evaluatie van ‘anders slapen’: een pilotonderzoek naar het effect van ‘anders slapen’ bij spanningshoofdpijn op Kwaliteit van Leven en participatie.

NARCIS (Netherlands)

de Vlugt, Liesbeth

2014-01-01

Samenvatting Inleiding- (Spannings)hoofdpijn is een veelvoorkomend probleem dat van invloed is op de Kwaliteit van Leven (KvL) en participatie van mensen in het dagelijks leven. Cervicogene hoofdpijn is een vorm van spanningshoofdpijn, waarbij de oorzaak gelegen is in spanning in de nek. Elkhuizen

Effects of ionizing radiation; Effecten van ioniserende straling

Energy Technology Data Exchange (ETDEWEB)

Loos, M.; Hardeman, F.; Holmstock, L.; Hurtgen, C.; Mahieu, L.; Sohier, A.; Vandecasteele, C.; Vanhavere, F.; Vanmaercke, H.; Zeevaert, T

1998-12-01

Starting with a brief introduction to radiation protection, the report gives an overview of exposure to ionising radiation in Belgium due to activities in relation to the nuclear fuel cycle, processing and disposal of radioactive waste and other artificial or natural sources. Where appropriate, the Belgian situation discussed from an international perspective. The radiological impact of reprocessing and non-reprocessing are compared. The biological effects of ionizing radiation, epidemiological studies as well as surveillance programmes on the Belgian territory are reported on.

Ontwikkeling en validatie van computer vision technologie ten behoeve van een broccoli oogstrobot

NARCIS (Netherlands)

Blok, Pieter M.; Tielen, Antonius P.M.

2018-01-01

De selectieve en handmatige oogst van broccoli is arbeidsintensief en omvat ongeveer 35% van de totale productiekosten. Dit onderzoek is uitgevoerd om te bepalen of computer vision kan worden gebruikt om broccoli kronen te detecteren, als eerste stap in de ontwikkeling van een autonome selectieve

Bachelorenquêtes 2013. Verslag van de bevindingen van recent afgestudeerden over hun opleiding

NARCIS (Netherlands)

Nielissen, Gé; Münstermann, Henk; Van den Munckhof, Rieny; Schlusmans, Kathleen

2018-01-01

De OU heeft vanaf haar oprichting veel aandacht besteed aan de kwaliteit en innovatie van het onderwijs. Medewerkers van de OU zijn gericht op vernieuwing en verbetering van het onderwijs, wat tot uitdrukking komt in de vele vernieuwingsinitiatieven die de afgelopen jaren hebben plaatsgevonden. De

Siektes van peroksisome - 'n oorsig

African Journals Online (AJOL)

(x 14 SOO). Peroksisoomsiektes2. ,3,5.6. Ongeveer 12 genetiese siektes wat as gevolg van foute in die ontwikkeling of in die samestelling van peroksisome antstaan, is reeds beskryf. Volgens die omvang van die biogenetiese fout en die graad van verlies aan peroksisoomfunksies word hierdie sindrome in 3 groepe.

Implementatie van EU-handhavingsvoorschriften

NARCIS (Netherlands)

Adriaanse, P.C.; Barkhuysen, T.; Boswijk, P.; Habib, K.; Kruif, C. de; Luchtman, M.J.J.P.; Ouden, W. den; Prechal, A.; Steunenberg, B.; Vervaele, J.A.E.; Voermans, W.J.M.; Vries, S.A. de; Widdershoven, R.J.G.M.

2008-01-01

Na een verkennend onderzoek op twaalf beleidsterreinen naar aard, wijze en variatie van de EU/EG-beïnvloeding van nationale handhaving, zijn aan de hand van ‘beïnvloedingsscores’ acht beleidsterreinen geselecteerd voor nadere analyse. In het onderzoek staan de volgende vragen centraal:Hoe is de

Childhood cancer in the vicinity of nuclear power plants. Results of a German study in perspective; Kinderkanker in de omgeving van kerncentrales. Resultaten van een Duitse studie in perspectief

Energy Technology Data Exchange (ETDEWEB)

Dekkers, S.A.J.; Slaper, H.; Tanzi, C.P.

2010-09-15

Whether or not childhood cancer occurs more frequently in the vicinity of nuclear power plants remains uncertain. The results of a German study completed in 2007 that found a significantly increased risk of disease are not confirmed in British and French investigations. This follows from work carried out at RIVM. In the German study, the so-called KiKK-study, the number of cases of childhood cancer in the vicinity of sixteen German nuclear power plants in recent decades was investigated. The study showed that children under the age of five who live within five kilometers of a nuclear power plant are at an increased risk of developing childhood cancer. The authors of the study are unable to explain this risk, which cannot be explained as an effect of the extremely limited extra radiation produced by a nuclear power plant. After publication of the KiKK-study's results questions were asked in Dutch parliament. The minister of VROM (housing, spatial planning and the environment) in response to these questions asked RIVM to compare the results of the German study with those of other studies and to give extra attention to the situation in the vicinity of Borssele, the location of the only Dutch nuclear power plant. In Borssele, circa three hundred children under the age of five live within five kilometers of the nuclear power plant. If the risk observed in Germany is applicable to the nuclear power plant at Borssele, one extra case of childhood cancer could be expected every thirty years. Epidemiological research would not be able to determine a frequency that low. A person living in the vicinity of the nuclear power plant at Borssele incurs less radiation from the power plant during a year, than the average dose a Dutch citizen receives in a single day from natural sources. The extra risk observed in Germany cannot be explained as the effect of such a low dose. [Dutch] Of kinderkanker nabij kerncentrales vaker voorkomt blijft onzeker. Het resultaat van een Duits

Prestatiemeting ten tijde van economische crisis: de aanpak van DSM

NARCIS (Netherlands)

van Rinsum, M.; den Dekker, R.; Maas, V.

2011-01-01

Deze studie besteedt aandacht aan de gevolgen van de financiële crisis voor het prestatiemeetsysteem van een onderneming. Vanwege de financiële crisis hebben veel ondernemingen naast langetermijndoelstellingen ook een aantal kortetermijndoelstellingen geformuleerd die betrekking hebben op hun

Invloed van waterconditioners en hulpstoffen op de effectiviteit van gewasbeschermingsmiddelen

NARCIS (Netherlands)

Zeeland, van M.G.

2007-01-01

In 2005 heeft de gebruikerscommissie naar aanleiding van de literatuurstudie over hulpstoffen drie aanbevelingen voor verder onderzoek geformuleerd. In 2006 zijn twee daarvan in onderzoek genomen, namelijk: wordt door toevoegen van waterconditioners (Easi-mix, Intake, X-change) aan hard water de

Opname van nicotine door kippen en overdracht naar eieren bij toepassing van nicotine tegen bloedluis

NARCIS (Netherlands)

Traag, W.A.; Rijk, de T.C.; Zomer, P.; Vos Van Avezathe, A.; Kan, C.A.; Zeilmaker, M.; Hoogenboom, L.A.P.

2005-01-01

Uit onderzoek van de AID blijkt nicotine gebruikt te worden voor de bestrijding van bloedluis bij kippen. Dit levert mogelijk gezondheidsrisico's op voor de consument van het kippenvlees of de eieren. Omdat niet duidelijk is of het nicotine na de bestrijding van bloedluis in het vlees of eieren

De syntaxis van de Italiaanse preposities

NARCIS (Netherlands)

Boer, M.G. de

2010-01-01

SAMENVATTING In dit hoofdstuk wordt een inventaris opgesteld van de Italiaanse preposities die voorkomen in een corpus bestaande uit de romans La Ciociara van Moravia en Il Gattopardo van Tomasi di Lampedusa. Achtergrond voor de herkenning van preposities is de Extended Standard Theory van de

Die skrifbeskouing van feministiese teoloë, in die besonder dié van Fiorenza, Brenner en Van Dijk-Hemmes – beoordeel in die lig van die gereformeerde teologie

Directory of Open Access Journals (Sweden)

Alta E. Swart

2013-10-01

Full Text Available Dit wil voorkom asof die feministiese Skrifbeskouing op die beginsel van selektiewe Skrifgesag berus. Dit beteken dat slegs dié dele in die Bybel wat met die feministiese ideologie ooreenstem, as gesaghebbend aanvaar word. Dit is veral die sogenaamde androsentriese taalgebruik wat dit vir aanhangers van hierdie benadering moeilik maak om die hele Skrif as gesaghebbend te erken. Hermeneuties vertoon hierdie benadering groot ooreenkomste met die Postmodernisme, waarin geen vaste reëls bestaan om die betekenis van tekste te bepaal nie. Gesien in die lig van die gereformeerde teologie, soos veranker in die Woord en belydenisskrifte, vertoon die feministiese teologie ernstige leemtes. Die bydraes (Skrifbeskouing van drie prominente feministiese teoloë – Fiorenza, Brenner en Van Dijk-Hemmes – word onder die loep geneem en teologies-krities geëvalueer ten einde hierdie leemtes uit te wys. It appears that the feminist view of Scripture is based on the principle of selective authority of the Scriptures, which means that only the parts of the Bible corresponding with the feminist ideology are accepted as authoritative. The use of androcentric language, in particular, makes it difficult for followers of feminism to accept the whole Bible as authoritative. Hermeneutically, their approach resembles Postmodernism, interpreting without any rules. Viewed from the paradigm of the reformed theology, which is anchored in Scripture and the articles of faith, feminist theology shows serious shortfalls. The contributions of three prominent feminist theologians – Fiorenza, Brenner and Van Dijk-Hemmes – are studied closely and evaluated critically in the light of the reformed theology, to underline these shortfalls.

Onderzoek naar het voorkomen van vijf sulfonamiden en Dapson in nieren van Nederlandse slachtvarkens

OpenAIRE

Vaessen HAMG; Kamp CG van de

1987-01-01

Onderzocht zijn 208 monsters varkensnier op voorkomen (HPTLC) en gehalte (HPLC) van sulfanilamide, sulfadimidine, sulfadoxine, sulfadiazine, sulfaquinoxaline en Dapson. De monsters waren afkomstig van slachthuizen gelegen in de zes veterinaire Inspectiegebieden. Uit het HPTLC onderzoek op voorkomen kwamen 8 monsters die kwantitatief werden onderzocht m.b.v. HPLC. Drie monsters bleken < 0,02 mg/kg sulfadimidine te bevatten, het sulfadimidinegehalte van de vijf andere monsters varieerde van ...

De geschiedenis van de keppel : van Borsalino hoed tot Spiderman keppel

NARCIS (Netherlands)

Ottenheijm, H.L.M.|info:eu-repo/dai/nl/164045775

2017-01-01

Keppels zijn er in alle soorten en maten. Na de Tweede Wereldoorlog werden ze hét symbool van het jodendom. Religiewetenschapper Eric Ottenheijm beschrijft de ontwikkelingen van de joodse hoofdbedekking.

De invloed van bodemreiniging op de biologische beschikbaarheid van metalen

NARCIS (Netherlands)

Adema DMM*; Boer JLM de; Gestel CAM van; Jong P de*

1987-01-01

Er werd onderzoek uitgevoerd met als doel het uitlooggedrag en de biologische beschikbaarheid van metalen in verontreinigde gronden voor en na reiniging te bepalen. Dit (deel)rapport beschrijft de resultaten van het onderzoek naar de biologische beschikbaarheid. Op zes locaties in Nederland

Clinical outcomes and repair integrity after arthroscopic full-thickness rotator cuff repair: suture-bridge versus double-row modified Mason-Allen technique.

Science.gov (United States)

Lee, Kwang Won; Yang, Dae Suk; Lee, Gyu Sang; Ma, Chang Hyun; Choy, Won Sik

2018-05-23

This retrospective study compared the clinical and radiologic outcomes of patients who underwent arthroscopic rotator cuff repairs by the suture-bridge and double-row modified Mason-Allen techniques. From January 2012 to May 2013, 76 consecutive cases of full-thickness rotator cuff tear, 1 to 4 cm in the sagittal plane, for which arthroscopic rotator cuff repair was performed, were included. The suture-bridge technique was used in 37 consecutive shoulders; and the double-row modified Mason-Allen technique, in 39 consecutive shoulders. Clinical outcomes at a minimum of 2 years (mean, 35.7 months) were evaluated postoperatively using the visual analog scale; University of California, Los Angeles Shoulder Scale; American Shoulder and Elbow Surgeons Subjective Shoulder Scale; and Constant score. Postoperative cuff integrity was evaluated at a mean of 17.7 months by magnetic resonance imaging. At the final follow-up, the clinical outcomes improved in both groups (all P  .05). The retear rate was 18.9% in the shoulders subjected to suture-bridge repair and 12.8% in the double-row modified Mason-Allen group; the difference was not significant (P = .361). Despite the presence of fewer suture anchors, the patients who underwent double-row modified Mason-Allen repair had comparable shoulder functional outcomes and a comparable retear rate with those who underwent suture-bridge repair. Therefore, the double-row modified Mason-Allen repair technique can be considered an effective treatment for patients with medium- to large-sized full-thickness rotator cuff tears. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Hoge resolutie typering van Coxiella burnetii

NARCIS (Netherlands)

Janse, I.; Bossers, A.; Roest, H.I.J.; Rotterdam, van B.

2011-01-01

Dit rapport beschrijft het onderzoek wat uitgevoerd is in het kader van het project ‘Hoge Resolutie Typering Coxiella burnetii’’. Het doel van dit project was om de genoomsequenties van een aantal Nederlandse isolaten van de bacterie Coxiella burnetii, de veroorzaker van Q-koorts, in kaart te

Studentopinie als onderdeel van Cursuskwaliteit : Quickscan

NARCIS (Netherlands)

Elzinga, Hanny; Groenewoud, Jan; Ike, Paul; Loth, Betram; Reitsma, Sieuwke; Schotanus, Janke; Schuurman, Mieke; Steur, Jessica

2015-01-01

In het kader van dit onderzoek is een quickscan (15 vragen) opgesteld met als doel die informatie te verzamelen die nodig is om een eerste indicatie te krijgen van de kwaliteit van een cursus (vak). De quickscan is gebaseerd op literatuuronderzoek en best practices van de faculteiten van de

Bepaling van 14C in afvalwater

NARCIS (Netherlands)

Hiemstra YS; Kwakman PJM; Nissan LN; Aldenkamp FJ; LSO

1998-01-01

In opdracht van de Hoofdinspectie Milieuhygiene van het ministerie van VROM heeft LSO een methode ontwikkeld om 14C in afvalwater van nucleaire installaties te bepalen. De methode meet organisch gebonden-14C en anorganisch-14C in de vorm van carbonaat (14CO32-) in afvalwater. Het rapport

Per maand of per kWh?: beoordeling van de effecten van een ander tariefsysteem voor kleinverbruikers electriciteit

NARCIS (Netherlands)

Aalbers, R.F.A.; de Nooij, M.

2006-01-01

Dit rapport bepaalt de effecten van de invoering van een capaciteitstarief voor de kosten van het transport van elektriciteit voor kleinverbruikers. Centraal kenmerk van een capaciteitstarief is dat kleinverbruikers niet langer per afgenomen kWh, maar een vast bedrag per aansluiting betalen. In het

Radiation belt electron acceleration during the 17 March 2015 geomagnetic storm: Observations and simulations

International Nuclear Information System (INIS)

Li, W.; Ma, Q.; Thorne, R. M.; Bortnik, J.; Zhang, X.-J.

2016-01-01

Various physical processes are known to cause acceleration, loss, and transport of energetic electrons in the Earth's radiation belts, but their quantitative roles in different time and space need further investigation. During the largest storm over the past decade (17 March 2015), relativistic electrons experienced fairly rapid acceleration up to ~7 MeV within 2 days after an initial substantial dropout, as observed by Van Allen Probes. In the present paper, we evaluate the relative roles of various physical processes during the recovery phase of this large storm using a 3-D diffusion simulation. By quantitatively comparing the observed and simulated electron evolution, we found that chorus plays a critical role in accelerating electrons up to several MeV near the developing peak location and produces characteristic flat-top pitch angle distributions. By only including radial diffusion, the simulation underestimates the observed electron acceleration, while radial diffusion plays an important role in redistributing electrons and potentially accelerates them to even higher energies. Moreover, plasmaspheric hiss is found to provide efficient pitch angle scattering losses for hundreds of keV electrons, while its scattering effect on > 1 MeV electrons is relatively slow. Although an additional loss process is required to fully explain the overestimated electron fluxes at multi-MeV, the combined physical processes of radial diffusion and pitch angle and energy diffusion by chorus and hiss reproduce the observed electron dynamics remarkably well, suggesting that quasi-linear diffusion theory is reasonable to evaluate radiation belt electron dynamics during this big storm.

Toepassing van finite difference- en finite element methoden voor het oplossen van een aantal stationaire grondwaterstromingsproblemen

NARCIS (Netherlands)

Wesseling, J.G.

1977-01-01

In dit verslag worden de oplossingsmethoden met de bijbehorende zelfontwikkelde FORTRAN computerprogramma's van de volgende stationaire grondwaterstromingsgevallen gegeven: - Analyse van de grondwaterstroming in een horizontaal vlak over een gedeelte van de Astense Aa, waar van plaats tot plaats

Die gebruik van tegnologie vir die ontwikkeling van professionele karaktereienskappe of sagte vaardighede van onderwysers deur afstandsonderrig

Directory of Open Access Journals (Sweden)

Johanna G. Ferreira

2016-02-01

Full Text Available Die doel van hierdie artikel was om ondersoek in te stel na die mate waartoe tegnologie suksesvol gebruik kan word om onderwysstudente deur afstandsonderrig op te lei. Omdat die sogenaamde sagte vaardighede en meegaande karatereienskappe eie is aan professies soos dié van medici of ouditeure, was dit nodig om te bepaal of onderwys wel as ’n professie beskou kan word. Die literatuur bevestig dit egter en gevolglik word aanvaar dat onderwys ’n professie is met gepaardgaande ‘sagte vaardighede’ of karaktereienskappe wat eie aan die beroep is. Vir effektiewe onderwys is die verwerwing van sodanige sagte vaardighede noodsaaklik. Die sagte vaardighede in die onderwysprofessie is derhalwe ondersoek en bespreek om ’n idee te kry van wat hierdie vaardighede behels en hoe hulle deur onderwysstudente ontwikkel en toegeëien kan word. Ten slotte is voorstelle gemaak oor hoe tegnologie ingespan kan word om sagte vaardighede by voornemende onderwysers deur afstandsonderrig te vestig.

Broeigedrag en -sukses van tuinduiwe

Directory of Open Access Journals (Sweden)

Pieter le Roux

2013-02-01

Full Text Available Broei-aktiwiteite van tuinduiwe (Columba livia in die Bloemfonteinse stadsgebied vind dwarsdeur die jaar plaas met ’n afname gedurende die laat somermaande wanneer seisoenale reënval in die streek ’n hoogtepunt bereik. Nesstrukture is relatief primitief en word gekenmerk deur ’n losse samestelling van nesmateriaal op opgehoopte, droë voëlmis. Broeisels van twee eiers is die mees algemene grootte en die eiers word gewoonlik binne twee dae ná mekaar gelê. Beide ouers is by die broeiproses van meer as twee weke betrokke, waartydens die eiers ’n progressiewe afname in massa ondergaan. Pas uitgebroeide neskuikens is met geel dons bedek en is grootliks hulpeloos. Egte vere begin eers ná die eerste week te voorskyn kom, en vanaf die derde week kan individue wankelrig rondbeweeg. Afgesien van die eerste paar dae na uitbroei, handhaaf neskuikens van seldsame enkeleier-broeisels deurgaans ’n laer liggaammassa as dié van normale broeisels. Die broeisukses van 247 broeipare vir hierdie studie is 34%. Eierverlies is hoër as die mortaliteitsyfer van neskuikens, en word veral deur klimaatsfaktore soos reënval geaffekteer. Predasie blyk die belangrikste faktor te wees wat die mortaliteitsyfer van neskuikens beïnvloed. Antagonistiese interaksie tussen krans- en tuinduiwe, asook moontlike intraspesie-aggressie, speel egter ook ’n beduidende rol.

Dutch Water Mining: Potentie van een zuiverend landschap van overvloed

NARCIS (Netherlands)

Os, van E.; Kruijs, A.; Bomas, B.; Poelman, M.; Pater, de M.; Bokhoven, van D.

2012-01-01

De blauwalg in het Volkerak - Zoommeer zorgt jaarlijks voor veel overlast. In de zomerperiode zijn giftig water en stank een hinderlijk fenomeen voor iedereen. Met de techniek Dutch Water Mining verdwijnt de overlast van blauwalgen. Voor de omliggende landbouwbedrijven ontstaat de zekerheid van een

Barcode van DNA. Democratisering van de taxonomie door digitaal identificatiesysteem

NARCIS (Netherlands)

Bakker, F.T.

2011-01-01

Het herkennen van biologische soorten aan de hand van een gestandaardiseerde DNA-barcode heeft de laatste tijd een enorme vlucht genomen. Gedreven door aan de ene kant de biodiversiteitscrises en de mogelijke global change, en aan de andere kant zowel razendsnelle technologische vooruitgang als ook

Die taak van akademiese geletterdheid/hede binne die konteks van ...

African Journals Online (AJOL)

Opsomming. Die vestiging van Akademiese Geletterdheid by tersiêre instansies in Suid-Afrika het gegroei uit die besef dat 'n goedontwikkelde akademiese taalvermoë essensieel is vir akademiese prestasie. Gepubliseerde literatuur getuig van die belangrike verskuiwings wat oor die afgelope aantal dekades plaasgevind ...

Contractiemechanisme en elektrolythuishouding van het geïsoleerde, overlevende rattehart, mede in verband met de werking van insuline

NARCIS (Netherlands)

Meijler, F.L.; Offerijns, F.G.J.; Willebrands, A.F.; Groen, J.

1959-01-01

Het waarnemen van een effect van insuline op de contracties van het geïsoleerde, overlevende rattenhart was aanleiding om de fysische verrichtingen in samenhang van het gehalte aan water en elektrolyten van dit orgaan tot onderwerp van studie te maken. Daarbij werd een zo goed mogelijk aan de

Die invloed van drie kruisbestuiwers op die saadinhoud van Minneola tangelo (Citrus parodist x C reticulata

Directory of Open Access Journals (Sweden)

H. J. Esterhuizen

1991-07-01

Full Text Available Die invloed van verskillende kruisbestuiwers (Clementine, Empress en Valencia op die gemiddelde saadinhoud van Minneo­la tangelo is ondersoek. Clementine en Empress as kruisbestuiwers het die grootste invloed op die gemiddelde saadinhoud van die vrugte gehad, terwyl dié van Valencia nie noemenswaardig was nie. Die gemiddelde saadinhoud van die vrugte het afgeneem met toename in afstand vanaf die kruisbestuiwer. Indien ’n beperking op die afstand tussen kultivar en kruisbestuiwer geplaas word, sal ’n groter persentasie vrugte aan uitvoerstandaarde ten opsigte van saadinhoud voldoen.

Rapport van het onderzoek naar de kosten, verbonden aan het bewaren van consumptie-aardappelen

NARCIS (Netherlands)

Anonymous,

1941-01-01

Het doel van deit rapport is vast te stellen hoe het verloop van den prijs van consumptie-aardappelen gedurende den winter en het voorjaar moet zijn om de gemaakte kosten en het verlies aan product goed te maken.

Dynamisch cloudsourcen van bedrijfsprocessen, gebruik van business rules management bij transitie en exit van BPO uit de cloud

NARCIS (Netherlands)

Rudolf Liefers; Jeroen van Grondelle; Johan Versendaal

2015-01-01

Dit artikel beschrijft een onderzoek waarbij gekeken is naar mogelijkheden die Business Rules Management-concepten bieden bij het aanbieden van bedrijfsprocessen as a service via een cloud-dienst. BRM helpt bedrijven door het gestructureerd vastleggen van organisatorische keuzes en regels waaraan

De vluchtige olie van enkele chemotypen van mentha suaveolens EHRH. en van hybriden met mentha longifolia (L.) HUDSON

NARCIS (Netherlands)

Hendriks, Hindrik

1974-01-01

De opvatting dat Mentha x piperita L. een bastaard zou zijn van Mentha spicata L. en Mentha aquatica L. werd nader besproken. Hierbij werd Mentha spicata beschouwd als een bastaard van Mentha longifolia (L.) HUDSON en Mentha suaveolens EHRH. ... Zie: Samenvatting.

Die verband tussen lokus van beheer en die werks prestasie van swart bemarkers in die lewensversekeringsbedryf

Directory of Open Access Journals (Sweden)

E. L. Coetzer

1997-06-01

Full Text Available The relationship between locus of control and the work performance of black marketers in the life assurance industry. The aim of the study was to establish the relationship between locus of control and the work performance of black marketers in the life assurance industry. These constructs were selected by virtue of the lack of empirical research regarding the assumed relationship between them. The Locus of Control Scale of Schepers (1995 was used for measuring locus of control. Work performance was measured by the commission earned per month by the marketer, the number of policies generated by the marketer, as well as the percentage of lapsed policies. The relevant measurements were obtained in respect of a sample of 149 black marketing personnel. The results indicated a modest but statistically significant relationship between external locus of control and the work performance of black marketers. Opsomming Die doel van die studie was om die verband tussen lokus van beheer en die werksprestasie van swart bemarkers in die lewensversekeringsbedryf te bepaal. Hierdie konstrukte is gekies op grond van die gebrek aan empiriese navorsing rakende die veronderstelde verband tussen genoemde konstrukte. Die Lokus van Beheer-vraelys van Schepers (1995 is in die meting van lokus van beheer gebruik. Werksprestasie is aan die hand van kommissie per maand verdien, aantal polisse gegenereer deur 'n bemarker en die persentasie vervalde polisse, gemeet. Die tersaaklike metinge is verkry ten opsigte van 'n steekproef van 149 swart bemarkers. Die resultate toon 'n klein, dog statisties beduidende verband tussen eksterne lokus van beheer en die werksprestasie van swart bemarkers in die lewensversekeringsbedryf.

Toepassing van DIN-ICP-MS en scanning-scouting van B en Mo in grondwater, drinkwater en regenwater

NARCIS (Netherlands)

van den Velde-Koerts T; LAC

1998-01-01

Doel van dit onderzoek was het ontwikkelen van een bepalingsmethode voor boor (B) en molybdeen (Mo) met ICP-MS om een indruk te krijgen van de concentraties in grond-, drink- en regenwater van Nederland. Omdat B adsorbeert aan de wand van de meeste verstuiverkamers (memory-effect) werd een directe

Evaluatie pilot toepassing van technieken op gebied van electronic monitoring binnen een penitentiaire inrichting

NARCIS (Netherlands)

Bekkers, R.N.A.; te Velde, R.; Segers, J.; Bilderbeek, R.

2008-01-01

Publicatienummer 2006.051-0713; Een evaluatie van een pilot inzake de toepassing van technieken op gebied van electronic monitoring binnen een penitentiaire inrichting. Wat zijn de gevolgen voor de veiligheid (incidenten, ontvluchtingen) en welk inzicht biedt een kosten-batenanalyse?

76 FR 9636 - Franklin Financial Corporation, Inc., Glen Allen, VA; Approval of Conversion Application

Science.gov (United States)

2011-02-18

... DEPARTMENT OF THE TREASURY Office of Thrift Supervision [AC-59: OTS No. H-4761] Franklin Financial... 11, 2011, the Office of Thrift Supervision approved the application of Franklin Financial Corporation MHC and Franklin Federal Savings Bank, Glen Allen, Virginia, to convert to the stock form of...

De metafoor van het washandje. Column

Directory of Open Access Journals (Sweden)

Yolan Koster-Dreese

2007-03-01

Full Text Available In hun artikel ‘Kwaliteit en Zorg’ van ruim tien jaar geleden stellen Van Houten en Prins (1995 dat de thans vigerende zorgtaal in meer algemene zin kan worden aangeduid als ‘zorg-Taylorisme’: een scientific management-benadering van zorg. Met de introductie van de ‘zorgmarkt’ is een benadering ontstaan die grote overeenkomsten vertoont met die scientific management-benadering uit het begin van de vorige eeuw, zo menen Van Houten en Prins.

Verzuring van bodem en grondwater als gevolg van atmosferische depositie

NARCIS (Netherlands)

Hoeks, J.

1983-01-01

In het kader van de Tweede-Kamer-rapportage over verzuring door atmosferische depositie heeft het ICW een bijdrage geleverd aan het deelrapport over effecten op bodem en grondwater. Deze ICW-notitie is hier nu nader uitgewerkt, waarbij vooral aandacht wordt besteed aan de methode om effecten van

Sedimentologische interpretatie van de afzettingen van de Nuenen-groep nabij Best

NARCIS (Netherlands)

Alphen; J.S.L.J.

1984-01-01

In het kader van het project "Variaties in fysisch-chemische bodemkarakteristieken" zijn twaalf boringen uit de Nuenen-groep bij Best beschreven. Uit deze beschrijvingen is de sedimentologische ontstaansgeschiedenis van de onderscheiden bodemlagen gereconstrueerd. Vijf pakketten

Brief overview of the role of ICT in saving energy; Beknopt overzicht van de rol van ICT bij de besparing van energie

Energy Technology Data Exchange (ETDEWEB)

Wartena, C.

2008-02-15

10 percent energy saving can be realized in households, offices and trade by means of smart information and communication technology. The saving is realized by a range of innovative measures that lead to this percentage without loss of comfort. One example is the heating in houses and offices by means of 'intelligent' software based on behavioral patterns and weather forecasts and on energy efficient hardware. The wide application of smart ICT in society can lead to 5 percent energy saving, thus rendering the 6 percent energy reduction target of the Kyoto Protocol within arm's reach. [mk]. [Dutch] Het is mogelijk om in huishoudens, kantoren en handel minstens 10 procent van het energiegebruik te besparen door de inzet van slimme informatie- en communicatietechnologie. De besparing wordt bereikt door een scala aan vernieuwende maatregelen die, zonder verlies van comfort, bij elkaar tot dit percentage leiden. Een voorbeeld is het door 'intelligente' software regelen van verwarming in huizen en kantoren afhankelijk van gedragspatronen en weersvoorspellingen en aan energiezuinigere hardware. De brede toepassing van slimme ICT in de samenleving kan ertoe leiden dat ongeveer 5 procent energie kan worden bespaard en dat de 6 procent energiereductie waartoe Nederland zich in het kader van het Kyoto-protocol heeft verplicht, binnen handbereik komt.

Afbouw van het Wsw-bestand: update 2011

NARCIS (Netherlands)

Berden, C.; Tempelman, C.

2012-01-01

In opdracht van het ministerie van Sociale Zaken en Werkgelegenheid heeft SEO Economisch Onderzoek recent onderzoek gedaan naar bouwstenen voor verdeelsleutels van het ongebundelde participatiebudget (Tempelman et al., 2012). Een onderdeel van dit onderzoek vormde het voorspellen van de afbouw van

Effecten van bosbegrazing op het humusprofiel van arme zandgronden onder naaldbos

NARCIS (Netherlands)

Kemmers, R.H.; Mekkink, P.; Smit, A.; Sevink, J.

1996-01-01

In het veld zijn de effecten van bosbegrazing op strooiselvoorraden onderzocht. Biomassa, pH, organische-stofgehalte, elektrisch geleidingsvermogen, elementenvoorraden en stikstofmineralisatie van strooisellagen werden gemeten na nul, twee en vijf jaar begrazing. De ondergrondse en bovengrondse

Die hermeneutiek van gereformeerde kerkreg

Directory of Open Access Journals (Sweden)

Andries le Roux du Plooy

2012-10-01

Full Text Available Die artikel het op die belangrikheid en noodsaaklikheid van ‘n hermeneutiek vir die gereformeerde kerkreg gefokus. Die kerkregtelike dokument wat besonderlik ter sake was, is die kerkorde van die Gereformeerde kerke in Suid-Afrika, met sy besondere band met die Dordtse kerkorde van 1618 en 1619. Agtereenvolgens is aandag gegee aan die volgende aspekte soos (1 die eiesoortige aard van ‘n kerkorde as ‘n teologiese dokument en teks, in onderskeiding van regsdokumente; (2 die aard van die hermeneutiek van kerkreg; (3 enkele teorieë oor die interpretasie of uitleg van tekste, veral regstekste en (4 normatiewe vooronderstellings en reëls vir die interpretasie en verstaan van die teks en artikels van die kerkorde asook besluite van kerklike vergaderinge. Die gevolgtrekking was dat weinig indringende navorsing gedoen is oor die saak van hermeneutiek vir kerkreg, hoewel dit noodsaaklik is. Duidelike hermeneutiese reëls is gesuggereer en verduidelik, wat sou kon meehelp dat kerke en kerklike vergaderinge die artikels van die kerkorde asook besluite en reglemente wat daarop berus het, kan interpreteer en toepas. The hermeneutics of reformed church polity. The article focused on the importance and urgency of a design for reformed hermeneutics on church polity. The Church Order referred to in the article is the Church Order of the Reformed Churches in South Africa, which are closely related to the Church Order of Dordt of 1618 and 1619. The following aspects received attention namely (1  the unique character of a Church Order, in comparison to and distinguished from legal documents and statutes; (2 the character and nature of hermeneutics of church polity; (3 theories of interpretation in the common law tradition and their relevance to church polity and (4 normative presuppositions and marks for the interpretation and understanding of the text and articles of the Church Order, as well as the resolutions of church assemblies. It was found that

Die nabyheid van die Koninkryk

Directory of Open Access Journals (Sweden)

W.J. Snyman

1963-03-01

Full Text Available Vanweë die belangrikheid daarvan volg hier ’n breër bespreking van die proefskrif van dr. Tjaart van der Walt oor die nabyheid van die Koninkryk as wat in ’n gewone resensie kan geskied. Die vraagstuk wat onder oë gesien word is so oud as die kerk en die teologie, soms minder en soms meer op die voorgrond. Tans kan gesê word, staan dit in die middelpunt. Daarby is dit nie maar ’n akademiese vraagstuk nie, maar ’n vraagstuk waarvoor elke nadenkende leser van die Skrif te staan kom.

Esperanto: een taal van mij, een taal om van te houden = Esperanto: lingvo malfremda, lingvo amida

NARCIS (Netherlands)

Jansen, W.

2010-01-01

Onderstaande tekst vormt de artikelversie van mijn op 4 september 2009 gehouden oratie bij de aanvaarding van het bijzonder hoogleraarschap in de interlinguïstiek en het Esperanto aan de Universiteit van Amsterdam (Jansen, 2009). Ten opzichte van de oorspronkelijke oratie is de nu volgende tekst op

Tim Allen, one of Hollywood's top comedy actors with Rolf Landua from CERN

CERN Multimedia

Laurent Guiraud

2000-01-01

Tim Allen ('Galaxy Quest', 'For Richer and Poorer', 'The Santa Clause', Voice of 'Buzz Lightyear', in Toy Story 1 and 2), visited CERN in July 2000. He has a keen interest in modern physics. In his last book "I'm not really here" he contemplates the funny and the intriguing aspects of quantum physics in his daily life.

Resultaten van de proeftuinen van PACT : inclusie door interprofessionele samenwerking in kindvoorzieningen 0-6 jaar

NARCIS (Netherlands)

Doornenbal, Jeannette; Balledux, Marielle; Fukkink, Ruben; Spoelstra, Jolanda; van Verseveld, Marloes; van Yperen, Tom

2018-01-01

In deze bijdrage worden de onderzoeksresultaten gepresenteerd van de ontwikkelingen in de PACT-proeftuinen om door middel van interprofessionele samenwerking tussen onderwijs, kinderopvang en zorg inclusie van elk kind te realiseren.

Bevordering van transformerende leer: Die skryf van ’n reflektiewe joernaal in die Natuurwetenskappe

Directory of Open Access Journals (Sweden)

Erna R. du Toit

2012-03-01

Full Text Available Die doel van die artikel is om aan te toon hoe die skryf van ’n reflektiewe joernaal in die Natuurwetenskappe die perspektiewe en denke van onderwysstudente kan transformeer en/of leer kan bevorder. Die studie maak voorspraak vir die gebruik van ’n reflektiewe joernaal as ’n instrument vir studente om betekenis te gee aan die leeromgewing vanuit verskillende perspektiewe deur te leer in praktyk. ’n Kwalitatiewe navorsingsmetode is gevolg om die inskrywings in ’n joernaal te analiseer aan die hand van bepaalde indikatore. Die bevindinge toon dat die meeste studente na die praktykervaring positief was en sommiges het tot ander perspektiewe vanweë hul ervaring gekom.

William Allen Miller (1817-70): a distinguished scientist re-discovered.

Science.gov (United States)

Ashley-Miller, Michael

2008-11-01

Dr William Allen Miller developed an early interest in science and astronomy at secondary school. Although qualifying in medicine, he pursued a career in Chemistry at King's College, London. A particular interest in spectrum analysis led to a collaboration with Dr Huggins in examining the spectra of stars. For this work they each received the Gold Medal of the Royal Astronomical Society. His subsequent work at King's College, the Royal Society, the Courts of Law and for various Government enterprises earned him an outstanding scientific and advisory reputation.

Effectiviteit van markting management support systemen

OpenAIRE

Bruggen, Gerrit; Smidts, Ale; Wierenga, Berend

1994-01-01

textabstractVerhoogt het gebruik van marketing management support systemen de kwaliteit van marketingbeslissingen? En zo ja, onder welke omstandigheden? Aan de hand van een experimenteel laboratoriumonderzoek met het simulatiespel MARKSTRATonder 80 marketing managers en 160 studenten, kan de eerste vraag positief worden beantwoord. Omstandigheden als tijdsdruk, ervaring in het nemen van marketingbeslissingen en de analytische capaciteiten van de gebruikers vormen een belangrijk aandachtspunt ...