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The Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK model) was developed by the U.S. Environmental Protection Agency to support assessments of health risks to children from exposures to lead (Pb).This study evaluated performance of IEUBK model (v2.0) as it would be typically applied at Superfund sites to predict blood Pb levels (BLLs) in populations of children.The model was evaluated by comparing model predictions of BLLs to 1144 observed BLLs in a population of children at the Bunker Hill Superfund Site for which there were paired estimates of environmental Pb concentrations.Predicted population geometric mean (GM) BLLs (GM: 3.4 µg/dL, 95% CI: 3.3, 3.5) were within 0.3 µg/dL of observed (GM: 3.6 µg/dL, 95% CI: 3.5, 3.8). The model predicted the observed age trend in GM BLLs and explained ~90% of the variance in the observed age-stratified GM BLLs. The mean predicted probability of exceeding 5 µg/dL (PAlthough the more general applicability of these findings to other populations remains to be determined in future studies, our results support applications of the IEUBK model (v2.0) for informing risk-based decisions regarding remediation of soils and mitigation of exposures at Superfund sites where the majority of the exposure unit GM BLLs are expected to be ≤5 µg/dL and where it is desired to limit the predicted probability of exceeding 5 µg/dL to5%.

HarmVect is a tool simulating the introduction of arthropods into Belgium. The tool is designed to guide the user to divide the complex arrival of the arthropod into all its potential pathways, which in turn are further subdivided into individual pathway segments. These manageable pathway segments are then used to specify which detailed data the user needs to gather to input into the tool. This information is used to simulate the magnitude of the arthropod population during the successive pathway segments throughout each potential introduction pathway. The tool simulates the fluctuating propagule pressure throughout the successive segments of each pathway to calculate risk indices, which are then used to generate pathway risk maps of the arthropod for Belgium. The tool generates 2 types of pathway risk map: (a) a point of entry pathway (POE) risk map consisting of concentrated hotspots relating to the arthropod's entry at national borders, and (b) a point of appearance (POA) pathway risk map, succeeding the POE and visualizing the locations and level at which undetected propagules of the arthropod are exposed to the outside environment throughout Belgium. In conclusion, the tool produces an establishment risk map for the arthropods, which is generated by combining the POA with a map of climate suitability and host availability.

The Japanese flower thrips, Thrips setosus, is a polyphagous insect which in Europe has mainly been observed on hydrangeas (Hydrangea spp.). The first report of T. setosus in the EPPO region was in the Netherlands (2014). Since then it has been observed in four other countries inside the EPPO region: Germany (2015), the United Kingdom (2016), France (2016) and Croatia (2016). Its dispersal is most likely to be related to trade. Because of its polyphagous nature, there is a risk of spread to other economically important crops. Therefore, T. setosus was included in the national survey project ‘STATREGO’, during which the status of several invasive plant pests and diseases in Belgium was determined.

Aluminum alloys 2099-T6 die forgings, 2099-T83 extrusions, 7075-T7651 plate, 7085-T7452 die forgings, 7085-T7651 plate, and 2397-T87 plate were thermally exposed at temperatures of 180 °C (350 °F), 230 °C (450 °F), and 290 °C (550 °F) for 0.1, 0.5, 2, 10, 100, and 1000 h. The purpose of this study was to determine the effect of thermal exposure on the mechanical properties and electrical conductivity of these alloys. The data shows that higher temperatures and longer exposure times generally resulted in decreased strength and hardness and increased percent elongation and electrical conductivity.

Atomic layer deposition is a promising technique to deposit conformal, nm-thin metal barriers in high aspect ratio trenches. However, exactly because of its excellent conformality, the deposition can also occur inside the nanopores of the most advanced low-k materials. In this work, the mechanisms of atomic layer deposition on and in low-k, porous dielectric films were studied, using HfO 2 as a test material. Exhaustive analyses showed firstly that the HfCl 4 precursor penetrated uniformly in the pores throughout a 44 nm low-k film. Secondly it is shown that the pores were sealed as function of precursor size, i.e. there are conditions where the pores became inaccessible for HfCl 4 , while the - smaller - H 2 O molecules could still penetrate the pores. From these analyses a deposition model was proposed.

The difference between the specific heat of a dilute [sup 3]He-[sup 4]He mixture and the specific heat of pure superfluid [sup 4]He at temperatures below the superfluid transition temperature is usually explained by considering the [sup 3]He as an ideal gas of quasiparticles with an energy spectrum that is not quadratic in the momentum, but which is difficult to justify on a theoretical basis. On the basis of a polaron-type model, introduced by three of the present authors, the specific heat of the mixture can be calculated, taking into account the emission and absorption of the phonon-roton excitations. In a temperature range where the [sup 3]He particles follow Boltzmann statistics, we find that the model accurately explains the experimental data for the specific heat. Therefore, the difference between the specific heat of the mixture and the specific heat of pure superfluid [sup 4]He can be explained as the result of the interaction of [sup 3]He with the excitations of the superfluid. Moreover, it is one of the most clearly measured polaron'' effects.

In order to get the accreditation EN ISO/IEC 17025 for Thrips palmi the Berlese-funnel technique, which is used for the isolation of quarantine insects out of plant material, was validated. Following parameters were investigated: cleaning of the funnel, temperature during isolation, detection limit and duration of the isolation period. Thrips fuscipennis was collected from heavily infected rosehip and used as target organism. Besides orchids, artificially contaminated maple leaves (Acer pseudoplatanus) were used for the validation. Results showed that thrips and other organisms can be present alive or dead in the funnel after removing the treated plants and can contaminate the next sample or isolate. Cleaning of the funnel with a vacuum cleaner and compressed-air apparatus is necessary before running a new extraction. Contamination of the recipient is also possible from the environment. This can be avoided by closing the opening between the funnel and the recipient. To reach an optimal temperature for isolation of the thrips a 60 Watt bulb is necessary. The results showed that the maximum temperature doesn't reach a temperature above 51 degrees C, the average temperatures were situated between 35, 74 degrees C and 39, 38 degrees C. A 40 Watt bulb doesn't create enough heat to guarantee an efficient isolation of the thrips; the average temperature was 34, 74 degrees C and the maximum temperature 36, 80 degrees C. Based on the results we can conclude that an isolation time of 20 hours is necessary to obtain accurate data. Dependent on the number of thrips in the artificially infected samples 87 to 95% is isolated after 20 hours. The detection limit is 1 thrips with a probability of 95% being isolated after 20 hours.

We measured the far infrared (FIR) absorption by the Gd 3+ ion in both randomly oriented and field oriented GdBa 2 Cu 3 O 7− σ powders in pulsed magnetic fields. The lower g anisotropy in the oriented samples reveals a superposition of two lines at low temperatures: one line with a g factor of 2.02 due to the Gd 3+ ions and another line with a g factor of 2.07 which we attribute to the Cu 2+ ions.

In the framework of the EUROMAGTECH cooperation, several coils for pulsed magnetic fields were developed and tested for their ultimate performance. A winding machine was developed which can reinforce each layer of conductor with a uniaxial wrap of fibers. Thus, optimum reinforcement can be obtained which resulted in coils producing 67 T in a 12-mm bore and 58 T in a 20-mm bore. Alternatively, a cable of pearlitic steel around a copper core was developed at BEKAERT, resulting in a wire with a strength of more than 1 GPa at a room-temperature conductivity of 60% IACS. This wire was wound into a coil with a bore of 17 mm, producing 54-T without noticeable radial deformation of the coil. >

We performed magneto-resistance measurements on a semi-metallic InAs–GaSb quantum well. By shining visible light on the sample, a Negative Persistent Photoconductivity effect (NPPC) was observed. Overnight illumination reduced the electron density of the sample from 9.54×1011 cm−2 to 9.04×1011 cm−2. A possible explanation for this effect is being sought in interface defect states.

During the period 2004-2006, 1691 samples of different origin were examined at the Diagnostic Centre for Plants. We received 1046 samples of imported plant material for detection and identification of quarantine organisms. More than 200 samples were checked on mites and insects to get a phytosanitary certificate for export and 391 samples were investigated for diagnostic reason. The Berlese-funnel and dissecting microscopy technique were used to separate mites from the samples. For identification, the mites were slide mounted in Berlese-Hoyer's medium and examined by using phase-contrast microscopy. In 3% of the samples examined on the presence of quarantine organisms, phytophagous mites belonging to the superfamily Tetranychoidea were found, but none with the quarantine status in accordance with the EPPO A1/A2 list. Besides Tetranychus urticae detected on different crops, the cassava green mite Mononychellus progresivus was found on cassava (import Cameroon) in 2006. Tenuipalpus elegans (Tenuipalpidae) was found on cut foliage (import South Africa) in 2004. In 19.9% of the investigated samples for diagnostic reason mites were found. In 47.7% of the infested samples mites were definitely the reason for the damage; in 15.9% mites were secondary and in 36.4% the occurrence of mites was not relevant for the injury. An overview of the determined mites will be given. During this 3 years diagnostic research a few new pest mites belonging to families Tetranychidae and Eriophyidae can be reported. In 2006 Panonychus citri was found on Prunus laurocerasus and later on Eleaegnus sp. and Skimmia sp.. Aceria silvicola was determined on Rubus idaeus in 2006 and Aculus ulae and Aceria carpini on Carpinus betulus in 2005. Besides new pest mites, never seen problems with the broad mite Polyphagotarsonemus latus (Fam. Tarsonemidae) occurred in tree-nurseries in 2005 and 2006. Also 20 samples coming from private persons were investigated. The main problems indoor were caused by Dermanyssus gallinae and Bryobia praetiosa. In gardens especially spider mite problems occurred. Eurytetranychus buxi, Oligonychus ununguis, Eotetranychus carpini and Eotetranychus tiliarium caused considerable damage in topiary and formal fences.

Interoperability between public administrations receives nowadays a lot of attention. Also in the European Union interworking is high on the priority list, but the challenges to achieve the European administrative space is enormous. Many research projects are undertaken, especially in the domain of semantic interoperability. Many of these efforts seem to start from a technical solution rather than from an actual business problem. By taking a narrow view on the problem space, they only promise limited support for the many challenges in the domain of interoperability and innovation of e-government services. In this paper we present a business driven approach that looks promising in enabling entire classes of interoperability solutions

We present FIR magneto-absorption experiments on InAs-GaSb heterojunctions. The results are discussed in terms of interband transitions and cyclotron resonances of a single electron (and a single hole) energy level. Fitting of the data to this model yields the position of these levels relative to the bottom of the quantum well.

Eotetranychus fagi (Acari: Tetranychidae) was first recorded in Belgium on Fagus sylvatica in Kortrijk in October 2002. In the autumn of 2003 E. fagi was noticed again at several locations in Flanders. Because F. sylvatica is often used as hedge plants in private gardens, it is expected that further spread of this spider mite will occur in the next few years.

Controlling the conformance of available bit rate (ABR) cells requires a dynamic usage parameter control (UPC) function to monitor and enforce the changing cell rates that are fed back by the network to the ABR source. Due to delays involved in the feedback control loop, rate changes conveyed in backward resource management (RM) cells may not immediately be enforced. This article presents the throughput analysis of a UPC function, based on a dynamic generic cell rate algorithm (DGCRA). In particular, analytical as well as simulative methods are used to describe the throughput behaviour of the UPC function monitoring the cell flow originating from a misbehaving ABR source. The throughput study shows that (i) unexpected UPC cell discard phenomena occur and (ii) more cell traffic may pass the UPC than expected by the network. It is also demonstrated to which extent the throughput results depend on e.g. the considered round trip times, the traffic contract and the degree of contract violation.

This paper investigates a Generic Cell Rate Algorithm (GCRA) based Usage Parameter Control (UPC) function implementing a discard function for non-conforming cells, thereby establishing a so-called Cell Discard Ratio (CDR) as UPC performance measure. Focusing on Constant Bit Rate (CBR) connections, the UPC transfer characteristics are studied in case of Peak Cell Rate Contract Violations. Also the influence of the Contracted Cell Delay Variation Tolerance value on the CDR performance of the UPC is incorporated in the study.

A theoretical analysis of the long jump take‐off is presented, with the conclusion that elastic effects are important. Measured data from the literature for groups of top athletes and average performers in the long jump confirm this conclusion and lead to an estimate of elastic energy conversion efficiency, which is very low (between 0.2 and 0.3), in contrast with much higher conversion efficiencies for the running stride.

An improved SPICE DC model for high-voltage DMOS transistors is proposed by considering the drift resistance modulation by both the gate and the drain voltages. A non-linear voltage controlled voltage source (VCVS) is introduced to represent this modulation. Results calculated from this model agree well with the experimental curves of the device DC characteristics

For MOSFETs operating at moderate and higher power levels a negative dynamic resistance is observed. An electro-thermal model based on the temperature dependence of the mobility and the velocity saturation is proposed.

Breakdown walkout in high-voltage pLDMOS transistors on a thin epitaxial layer is observed and investigated by using ion implantation to vary the surface electric field in the drift region. Results show that the walkout is closely related to the surface field and can be reduced by determining the correct extent of ion implantation.

The CESR linewidth of pure aluminium is shown to have a temperature dependent phonon contribution which is largely frequency independent. A second term in the linewidth is found to be temperature independent but linearly dependent upon frequency giving 0.11 mT per GHz. Finally it is shown that if partial breakdown of motional narrowing occurs it contributes a term proportional to the frequency and not, as expected, to the frequency squared.

Results are presented of an electron spin resonance (ESR) study carried out at cryogenic temperatures (4.2 K≲T≲35 K) at X‐ and K‐band frequencies of spin‐active defect centers created by ion implantation of 1014 As+ cm−2 at 60 or 80 keV into the SiO2 layer of Si‐SiO2 structures (dSiO2=104–130 nm). Observations were made on single‐crystal boron doped (001) Si wafers of resistivities ρ300 K=0.23 and 22 Ω cm, which had been thermally oxidized. In general, three well‐distinguished centers are observed; two signals, which originate from centers residing in the SiO2 layer, showed typical ‘‘glass’’ pattern line shapes. The first is definitely proven to be the E′ center, which constitutes the first clear experimental evidence of the E′ center in ion‐implanted Si/SiO2 structures. The second signal is shown to correspond very nearly with the ‘‘wet’’ oxygen‐related hole center (OHC) with zero crossing of the derivative spectrum dP/dB given by ga=2.0095. A third previously unreported anisotropic center located at the...

A magnetic resonance spectrometer is described with an HCN laser and an optically pumped FIR laser as radiation sources. The latter enables us to measure magnetic resonances at many frequencies throughout the FIR range. High magnetic fields up to 35 T are generated by means of a capacitor discharge with 10 ms pulse duration. The results of our measurments on LiErF4 are in good agreement with resonance conditions calculated from parameters found by Hansen et al[10]. Different aspects of FIR magnetic resonance spectroscopy are discussed.

Analytical solutions for the radial and tangential stresses in the midplane of long magnetic field coils are derived, for both constant current density and a 1/r current distribution. The elastic anisotropy is contained in the solution as the ratio of the axial and tangential modulus of elasticity. The critical tangential stress is largest at the inner surface for coils with radial transmission of stress; this is greatly reduced if the coil is softer in the radial direction. An outer reinforcing cylinder becomes quite ineffective in this case. The average axial stress in the midplane is calculated for inclusion in Timoshenko's criterion. The authors also calculate the critical stresses in polyhelix coils with equally distributed stress among the layers. These have a modest advantage over radially soft coils only for a large number of layers.

The effect of the observational frequency upon the Conduction Electron Spin Resonance recorded from silver foils and sodium in quartz tubes is reported. For both materials an increase in frequency results in an increase in linewidth, a linear relationship being indicated for silver. We interpret some features of the results as being due to surface effects, additional evidence for the influence of the surface on CESR coming from surface treatment of copper foils.

The influence of ion implantation of 56Fe and 63Cu on the bulk properties of the conduction electrons in aluminium has been investigated with the reflection conduction electron spin resonance (CESR) technique at 21 GHz. The doses were kept low and varied from 3*1013 to 5.4*1014 atoms cm-2. Below 25K, large line broadening and an unexpected g rise has been found in the nonannealed Fe implanted samples, which indicate the existence of surface spins. From the similarity between pure and ion implanted Al it is concluded that surface spins may be important in the so called pure Al too.

CW saturation ESR experiments at 20.9 and 9.0 GHz have been carried out between 4.2 and 300 K on a-Si films sputtered on fused silica substrates. The ESR signal (of g = 2.0050 ± 0.0001) ascribed to dangling bonds in the a-Si network shows up to be strongly saturatable (onset of saturation at K-band microwave power PS ≲ 1μW at 4.2 K). Submitting the a-Si film subsequently to a SiO2 chemical etchant drastically decreases (PS increased by more than a factor 1500) the saturatability from where a strongly phonon-bottlenecked (PBN) spin—lattice relaxation regime is concluded to exist on the non-etched films. This PBN is ascribed to O2 contamination, enhancing the saturatability in two steps.

The linewidths of the conduction electron spin resonances from high purity aluminium foils and films are measured at frequencies of 9.27 and 20.98 GHz using reflection spectrometers. An attempt is made to fit a breakdown of motional narrowing model to the data. It is found that such a model cannot satisfactorily explain the dependence of the linewidths on frequency, temperature, and sample thickness. Likewise a model based on many-body effects, although explaining some of the features of the results, does not fit all the data. It is possible that a contribution to the impurity induced linewidth which is frequency dependent would provide a better fit and it is concluded that to fully interpret the data a more complex theory is necessary. Leslargeurs de raie des spectres de resonance magnetique des electrons de conduction dans ľaluminium ont ete mesurees a des frequences de 9.27 et 20,98 GHz. Les echantillons etaient sons forme de films ou de couches minces. avec des epaisseurs variant entre 0.8 et 3.8 μm. On a essaye ďexpliquer les resultats par des modeles comprenant les effets de diffusion et ďinteraction d′bechange. Ces modeles ne peuvent pas expliquer toutes les donnees sur la variation des largeurs de raie causee par ľinteraction des electrons avec les impuretes que ľon suppose dependante de la frequence. Ľon peut en conclure qu′une theorie plus complexe est neessaire.

A simple theory of rolling resistance is compared to experimental results on rolling billiard balls. The resistive force is shown to be independent of velocity for velocities smaller than 0.5 m/s. The sliding friction coefficient is determined by measuring the force needed to immobilize a skidding ball. The coefficient increases with increasing sliding velocity and approaches asymptotically the value of 0.21 which is quoted in the literature.

The Hall coefficient and the transverse magnetoresistance in aluminium single crystals were determined from measurements on standing helicon waves, in the three main crystallographic directions [100], [110] and [111]. The magnetic fields ranged from 1 to 7T and the temperature from 4.2 to 20 K. A Legendy-type theory with parameters adapted to the separation of the satellites as measured at high fields gave good fittings over the whole field range. The Hall coefficients, determined in this work, decrease with magnetic field as mentioned in earlier publications, but are generally lower than those published previously for comparable field ranges. The transverse magnetoresistance as a function of temperature was determined from a continuous recording of the helicon response at resonance. The temperature dependent part of the resistivity varies according to a T 3 law for all fields. The field dependence is close to linear, but indications of quadratic and saturation behaviour are also present.

We measured the ferromagnetic resonance absorption in pulsed fields up to 35 T. The linewidth is analysed in terms of the phenomenological damping parameter λ and the exchange-conductivity broadening. λ was determined in the 3d metals Ni and Fe as a function of frequency and temperature.

A simple theory is developed for the interaction of conduction electron spins with local moments in the bulk or at the surface of the metal, with emphasis on the conduction electron system, which is considered most important. When considering a local moment system with a distribution in g-values and introducing an interaction strength in the electron system, this can give rise to extra linewidth terms, depending on the coupling strengths between the d-s, d-d, and s-s subsystems, as compared to the width of the g-distribution in the d-system. Une theorie simple a ete construite pour expliquer l'interaction des electrons de conduction avec des moments magnetiques locaux situes dans le metal ou sur la surface. On accepte que le systeme des electrons de conduction est le plus important. En considerant un systeme compose de moments locaux avec une distribution des facteurs g et en introduisant une certaine force d'interaction dans le systeme des electrons, on arrive a des largeurs de raie des spectres affectuees par la distribution des facteurs g. Cet elargissement depend evidemment des forces d'interaction entre les systemes d-s, d-d et s-s.

A reinterpretation is presented of recent results (Chizhov et al. 1982) on the conduction electron spin resonance (CESR) linewidths recorded from small lithium particles to which small levels c of sodium impurities have been added. This reanalysis demonstrates good agreement with contemporary understanding of interface spin scattering in bimetallic, layered, systems. It is shown that the sodium segregates out to the surface of the lithium particles. A maximum of three atomic layers of sodium on the surface gives rise to the observed spin-flip probability of the lithium conduction electrons at the surface, ϵ obs , being equal to ϵ Na where ϵ Na is the surface spin-flip probability for the sodium-vacuum interface. We approximate, for sufficient sodium impurities, ϵ obs = ϵ Na to σ sf , Li (Na)/ σ r , Li (Na) where σ sf , Li (Na) and σ r , Li (Na) are the spin-flip and resistivity scattering cross sections respectively for Na impurities in Li. From this relationship it is predicted that the amount of CESR linewidth broadening due to dissolved Na, is ΔB i (Na)/ c = 0.11 mT/at.%.

A comprehensive resonance-like experiment for an undergraduate electronics workshop is described. The main purpose is to demonstrate how a microprocessor can be used in experiments and the power this can have as a noise-reduction technique. The experiment demonstrates that, when using signal averaging, the increase of the signal-noise ratio is proportional to the square root of the number of repetitions.

The exchange parameters and saturation magnetization have been measured for a large number of films of nickel-cobalt alloys. The data are obtained from standing spin wave resonance at room temperature in a conventional 9 GHz spectrometer. The distortions in the spectra are accounted for by a first order perturbation calculation. 1 The results are analysed using a model proposed by Hatherley et al . 2 Within the framework of this model values for the second moment of the exchange integral between NiNi, NiCo and CoCo pairs of atoms are derived.

Une etude a ete faite sur la resonance ferromagnetique de couches de permalloy, deposees dans le vide. Pour cette recherche nous avons utilise un spectrometre a ondes centimetriques (3 cm). Nous avons examine l'influence des facteurs suivants : 1) Le degre du vide utilise lors du depot ; vide variant de 10—5 mm. Hg jusque 10 —9 mm. Hg. 2) La variation des grandeurs 4πMs et g entre les temperatures de 300 °K et 4 °K. 3) Les effets que les ondes de spins ont sur le phenomene de resonance. 4) L'influence de la structure des couches sur les raies d'absorption. Finalement nous avons compare la forme des raies avec une solution simplifiee de l'equation de Bloch.

Polycristalline copper surfaces and germanium single crystals were bombarded with 1000 eV argon ions. The argon ions were produced by means of an electron current between a heated tungsten cathode and an anode at a potential of +300 V. The pressure of the argon gas was maintained at 10−3 mm Hg. The whole system could be evacuated to 10−6 mm Hg with an oil diffusion pump.

On sait que les raies de resonance ferromagnetique dans les couches de permalloy deposees par evaporation sont plutot fines, comparees a celles d'autres metaux ferromagnetiques. Nous avons realise un montage pour observer la resonance ferromagnetique dans les couches minces, en fonction de leur epaisseur. Nous n'avons pas trouve d'influence de l'epaisseur de la couche, mais nous avons observe, pour certaines couches, une raie de resonance possedant deux maxima : nous pensons qu'il s'agit la d'un effet d'heterogeneites ou de tensions existant dans la couche, et qui peuvent dependre des conditions d'evaporation.

A wide sampling of eighty-two modern marine and freshwater muds was analyzed for B, Cr, Ga, Ni, V, clay in amounts less than $$2 \mu (

The damages induced in solid crystalline DPPH, when neutron irradiated at liquid nitrogen temperature, is studied using the technique of paramagnetic resonance. A model is proposed which explains satisfactorily the observed variation in g-value, linewidth and spin concentration.