Op zoek naar het Griensvenneke

Uit de bestudering van kaartmateriaal, toponiemen en archiefmateriaal zijn sterke aanwijzingen naar voren gekomen dat langs de Spekstraat in Den Dungen een ven gelegen moet hebben (Van Minderhout et al. 2011). Ook wordt de plaats genoemd in relatie tot turfwinning. Tot in de late Middeleeuwen was dit een heidegebied met een ven. Vermoedelijk is het ven tijdens of na het ontginnen van de heide in de 14e en 15e eeuw dichtgegroeid of dichtgewaaid. Bij een eerste verkenning met een grondboor door een van ons konden geen aanwijzingen gevonden worden voor het voorkomen van een venbodem

Op zoek naar het Griensvenneke

Uit de bestudering van kaartmateriaal, toponiemen en archiefmateriaal zijn sterke aanwijzingen naar voren gekomen dat langs de Spekstraat in Den Dungen een ven gelegen moet hebben (Van Minderhout et al. 2011). Ook wordt de plaats genoemd in relatie tot turfwinning. Tot in de late Middeleeuwen was dit een heidegebied met een ven. Vermoedelijk is het ven tijdens of na het ontginnen van de heide in de 14e en 15e eeuw dichtgegroeid of dichtgewaaid. Bij een eerste verkenning met een grondboor door een van ons konden geen aanwijzingen gevonden worden voor het voorkomen van een venbodem

Charge neutralisation of microparticles by pulsing a low-pressure shielded spatial plasma afterglow

In this paper, it is shown that microparticles can be effectively neutralised in the (spatial) plasma afterglow of an inductively coupled plasma. A key element in the reported experiments is the utilisation of a grounded mesh grid separating the plasma bulk and the 'shielded' plasma afterglow. Once particles-being injected in and charged by the inductively coupled plasma-had passed this mesh grid, the plasma was switched off while the particles continued to be transported under the influence of both flow and gravity. In the shielded spatial plasma afterglow region, the particle charge was deducted from their acceleration in an externally applied electric field. Our experiments demonstrate that all particles were neutralised independently of the applied electric field magnitude. The achieved neutralisation is of primary importance for the further development of plasma-assisted contamination control strategies as well as for a wide range of other applications, such as colourimetric sensing, differential mobility analysers, and medical applications

Plasma assisted particle contamination control:Plasma charging dependence on particle morphology

With the introduction of EUV lithography, the control of contamination in advanced semiconductor processes has become increasingly critical. Our work is a joint effort (TU/e and VDL-ETG) and is aimed at the development of plasma-assisted contamination control strategies mainly focusing on airborne particles in a low pressure gas. We present experiments comparing the charge-to-mass ratio of single spherical micron-sized particles with that of non-spherical agglomerates thereof in the spatial plasma afterglow. It is shown that the charge-to-mass ratio of two-particle clusters deviates only 6% from that of singlets. This means that for the proposed mitigation strategy, of which the efficiency is based on the charge-to-mass ratio, it is acceptable to study the charging of spherical particles and to extrapolate the results towards non-spherical particles within a reasonable range.</p

Quantitative visual field analysis of squinting eye under binocular conditions in ten patients with microstrabismus

Introduction: It is still not exactly known how strabismic patients perceive the surrounding world. It is commonly believed that patients with early onset convergent strabismus and microstrabismus do not suffer from diplopia because of two mechanisms: suppression and anomalous retinal correspondence (ARC). Suppression only occurs under binocular viewing conditions and concerns the central part of the visual field of the strabismic eye. Suppression is associated with a decrease of binocular functions in the central part of the visual field. ARC can be described as a form of internal squint that corrects for the image disparity due to external squint. It is the defence mechanism against diplopia in the more peripheral visual field. There is evidence however that this shift in retinal localisation does not affect the visual field equally. It seems that ARC is more outspoken in the periphery than in the centre of the visual field. This might be expl

Charge of clustered microparticles measured in spatial plasma afterglows follows the smallest enclosing sphere model

The plasma-induced charge of non-spherical microparticles is a crucial parameter in complex plasma physics, aerosol science and astrophysics. Yet, the literature describes this charge by two competing models, neither of which has been experimentally verified or refuted. Here we offer experimental proof that the charge on a two-particle cluster (doublet) in the spatial afterglow of a low-pressure plasma equals the charge that would be obtained by the smallest enclosing sphere and that it should therefore not be based on its geometrical capacitance but rather on the capacitance of its smallest enclosing sphere. To support this conclusion, the size, mass and charge of single particles (singlets) and doublets are measured with high precision. The measured ratio between the plasma-afterglow-induced charges on doublets and singlets is compared to both models and shows perfect agreement with the predicted ratio using the capacitance of the smallest enclosing sphere, while being significantly dissimilar to the predicted ratio based on the particle’s geometrical capacitance

Particle contamination control by application of plasma

With the introduction of Extreme Ultraviolet (EUV) lithography, the control of contamination has become crucial. Sources for contamination in EUV lithography scanners are not limited to only particle generation and release inside the scanner environment but may be introduced from outside as well, e.g. through translational and/or rotational (robotic) feedthroughs.\u3cbr/\u3eIn this contribution we highlight our joint (TU/e and VDL ETG) research efforts aimed at the development of plasma-enabled contamination control strategies. The focus in this research is on airborne particles immersed in a low pressure gas flow that interact with both the afterglow of a plasma and an externally applied electric field.\u3cbr/\u3eA flexible experimental setup has been developed and will be introduced which is able to study the interaction between contaminants, plasmas and externally applied electric fields. Our results show that the designed configuration allows to carefully control the residual charges of the particles as well as their positions and trajectories with respect to the gas flow in which they are immersed. These results, together with the understanding of the underlying principle processes, open-up various possibilities to achieve improved cleanliness of the mentioned systems

Plasma assisted particle contamination control: Plasma charging dependence on particle morphology

With the introduction of EUV lithography, the control of contamination in advanced semiconductor processes has become increasingly critical. Our work is a joint effort (TU/e and VDL-ETG) and is aimed at the development of plasma-assisted contamination control strategies mainly focusing on airborne particles in a low pressure gas. We present experiments comparing the charge-to-mass ratio of single spherical micron-sized particles with that of non-spherical agglomerates thereof in the spatial plasma afterglow. It is shown that the charge-to-mass ratio of two-particle clusters deviates only 6% from that of singlets. This means that for the proposed mitigation strategy, of which the efficiency is based on the charge-to-mass ratio, it is acceptable to study the charging of spherical particles and to extrapolate the results towards non-spherical particles within a reasonable range

Nightblindness-Associated Transient Tonic Downgaze (NATTD) in Infant Boys with Chin-Up Head Posture

Eleven infant boys presented with chin-up head posture, tonic downgaze and, on attempted upgaze, large-amplitude upward saccades with deceleration during the slow phase downward. The gaze-evoked upward saccades disappeared at the age of 2 or 3 years. In addition, they had high-frequency, small-amplitude horizontal pendular nystagmus that remained. Among these infant boys were 2 pairs of maternally related half-brothers, 2 cousins, and 2 siblings. Visual acuity ranged from 0.1 to 0.6, ERG-amplitudes (both A- and B-wave) were reduced, and severe myopia was found in 5 cases. Eight boys had CACNA1F mutations, and 1 boy had a NYX mutation, compatible with incomplete or complete congenital stationary nightblindness (iCSNB or cCSNB), respectively. This points to a defective synapse between the rod and the ON-bipolar cell causing the motility disorder: CACNA1F is located on the rod side of this synapse, whereas NYX is located on the side of the ON-bipolar cell. The coexistence of horizontal and vertical nystagmus has been previously described in dark-reared cat