Untersuchung der hydraulischen Bodeneigenschaften durch GPR: Analyse der Kapillarsaumreflexion durch numerische Simulationen

Die Kapillarsaumreflexion von einem Wassergehaltsprofil im hydraulischen Gleichgewicht und während eines Pumpvorgangs wird durch numerische Simulationen einer on-ground GPR-Messung untersucht. Diskutiert wird die Abhängigkeit des reflektierten Wavelets von den hydraulischen Parametern und dem Parametrisierungsmodell, wobei die Modelle von Brooks-Corey, van Genuchten und dessen vereinfachte Form mit m=1-1/n verwendet werden. Durch Benutzung von Informationen aus dem Zeitbereich und dem Frequenzbereich sind die Auswirkungen der Parameter unterscheidbar, die verschiedenen Parametrisierungsmodelle zeigen signifikant unterschiedliche Reflexionen. Zwei Pumpexperimente am ASSESS-GPR Testfeld werden diskutiert, bei denen zeitabhängige Messungen mit einer stationär platzierten GPR-Antenne durchgeführt wurden. Im ersten Experiment wird eine durch Verdichtung entstandene Schicht nachgewiesen. Die resultierende Änderung der hydraulischen Parameter relativ zum nicht verdichteten Sand werden diskutiert. Die Radargramme des zweiten Experiments erlauben die Identifikation des Kapillarsaums und seiner Bewegung durch den Boden. Die erwartete Dynamik der Wasserverteilung kann durch die Radargramme nachvollzogen werden. Ein Vergleich der beobachteten Kapillarsaumreflexion mit numerischen Simulationen erlaubt die Auswahl eines passenden Parametrisierungsmodells aus den genannten Modellen. Die gemessenen Radargramme werden mit manuell angepassten Parametern durch numerische Simulationen semi-quantitativ reproduziert. Insgesamt rechtfertigen die Ergebnisse die Möglichkeit einer Inversion der GPR-Daten zur Schätzung der hydraulischen Parameter. Ein Vorschlag für eine Inversion wird gegeben

Can Preschool Age Children Be Grouped By Temperament? A Quantitative Analysis Of Survey Data

Temperament is a widely researched construct and has significant influence in people’s lives. Still, theorists differ on their approaches to and perspectives on this topic. In their famous New York Longitudinal Study (NYLS), Thomas, Chess, and Birch (1968) gathered information through parent interviews and observations of 136 children. These investigators categorized children as easy, difficult, or slow to warm up based on the temperament characteristics reported in their study. Other researchers have found temperament profiles in children that are similar but not completely consistent with those of Thomas and colleagues. The purpose of the current study is to corroborate and extend the research that places children into groups based on similarity of temperament. Following previous research, I hypothesized that there would be five groups of children. A cluster analysis was used to identify four groups that converge with the findings in previous research—difficult, dilligent, interested, and moderate groups of children—and one group that diverges from previous studies—a disengaged group

Development of a pressure stable inline droplet generator with live droplet size measurement

For the research on droplet deformation and breakup in scaled high-pressure homogenizing units, a pressure stable inline droplet generator was developed. It consists of an optically accessible flow channel with a combination of stainless steel and glass capillaries and a 3D printed orifice. The droplet size is determined online by live image analysis. The influence of the orifice diameter, the mass flow of the continuous phase and the mass flow of the disperse phase on the droplet diameter were investigated. Furthermore, the droplet detachment mechanisms were identified. Droplet diameters with a small diameter fluctuation between 175 µm and 500 µm could be realized, which allows a precise adjustment of the capillary (Ca) and Weber (We) Number in the subsequent scaled high pressure homogenizer disruption unit. The determined influence of geometry and process parameters on the resulting droplet size and droplet detachment mechanism agreed well with the literature on microfluidics. Furthermore, droplet trajectories in an exemplary scaled high-pressure homogenizer disruption unit are presented which show that the droplets can be reinjected on a trajectory close to the center axis or close to the wall, which should result in different stresses on the droplets

Scaling of Droplet Breakup in High-Pressure Homogenizer Orifices. Part II: Visualization of the Turbulent Droplet Breakup

Emulsion formation is of great interest in the chemical and food industry and droplet breakup is the key process. Droplet breakup in a quiet or laminar flow is well understood, however, actual in-dustrial processes are always in the turbulent flow regime, leading to more complex droplet breakup phenomena. Since high resolution optical measurements on microscopic scales are extremely dif-ficult to perform, many aspects of the turbulent droplet breakup are physically unclear. To over-come this problem, scaled experimental setups (with scaling factors of 5 and 50) are used in con-junction with an original scale setup for reference. In addition to the geometric scaling, other non-dimensional numbers such as the Reynolds number, the viscosity ratio and the density ratio were kept constant. The scaling allows observation of the phenomena on macroscopic scales, whereby the objective is to show that the scaling approach makes it possible to directly transfer the findings from the macro- to the micro-/original scale. In this paper, which follows Part I where the flow fields were compared and found to be similar, it is shown by breakup visualizations that the turbulent droplet breakup process is similar on all scales. This makes it possible to transfer the results of detailed parameter variations investigated on the macro scale to the micro scale. The evaluation and analysis of the results imply that the droplet breakup is triggered and strongly influenced by the intensity and scales of the turbulent flow motion

Novel-word learning, executive control and working memory: A bilingual advantage

Studies of the effects of bilingualism on cognition have given results that do not consistently replicate, reflecting at least in part wide differences in criteria for bilingualism and heterogeneity of language combinations within studied samples. We examined the bilingual advantage in attention, working memory and novel-word learning in early sequential Hindi–English bilinguals. We sought to clarify the aspects of cognition that benefit from bilingualism by using multiple measures and a sample sufficiently well-defined to permit independent replication. Bilinguals outperformed monolinguals on response inhibition, novel-word learning and almost all working memory tasks. In contrast, both groups performed comparably on selective attention. Analyses of individual differences showed that bilingual novel-word learning was related to their verbal working memory and ability to inhibit an ongoing action, whereas this was not the case for monolinguals. Results indicate a specific bilingual advantage that is confined to some but not all aspects of cognition

Centre–surround inhibition is a general aspect of famous-person recognition: evidence from negative semantic priming from clearly visible primes

A Centre-Surround Attentional Mechanism was proposed by Carr and Dagenbach (1990) to account for their observations of negative semantic priming from hard-to-perceive primes. The mechanism cannot account for the observation of negative semantic priming when primes are clearly visible. Three experiments (n = 30, 46, and 30) used a familiarity decision to names of famous people preceded by prime names of the same or different occupation. Negative semantic priming was observed at 150 or 200ms SOA with positive priming at shorter (50ms) and longer (1000ms) SOA. Experiment 3 verified that the primes were easily recognisable in the priming task at a SOA that yielded negative semantic priming, which cannot be predicted by the original Centre-Surround mechanism. A modified version is proposed that explains transiently negative semantic priming by proposing that Centre-Surround inhibition is a normal, automatically invoked aspect of the semantic processing of visually-presented famous names

The Validity of d′ Measures

Subliminal perception occurs when prime stimuli that participants claim not to be aware of nevertheless influence subsequent processing of a target. This claim, however, critically depends on correct methods to assess prime awareness. Typically, d′ (“d prime”) tasks administered after a priming task are used to establish that people are unable to discriminate between different primes. Here, we show that such d′ tasks are influenced by the nature of the target, by attentional factors, and by the delay between stimulus presentation and response. Our results suggest that the standard d′ task is not a straightforward measure of prime visibility. We discuss the implications of our findings for subliminal perception research

Prevailing theories of consciousness are challenged by novel cross-modal associations acquired between subliminal stimuli

While theories of consciousness differ substantially, the ‘conscious access hypothesis’, which aligns consciousness with the global accessibility of information across cortical regions, is present in many of the prevailing frameworks. This account holds that consciousness is necessary to integrate information arising from independent functions such as the specialist processing required by different senses. We directly tested this account by evaluating the potential for associative learning between novel pairs of subliminal stimuli presented in different sensory modalities. First, pairs of subliminal stimuli were presented and then their association assessed by examining the ability of the first stimulus to prime classification of the second. In Experiments 1-4 the stimuli were word-pairs consisting of a male name preceding either a creative or uncreative profession. Participants were subliminally exposed to two name-profession pairs where one name was paired with a creative profession and the other an uncreative profession. A supraliminal task followed requiring the timed classification of one of those two professions. The target profession was preceded by either the name with which it had been subliminally paired (concordant) or the alternate name (discordant). Experiment 1 presented stimuli auditorily, Experiment 2 visually, and Experiment 3 presented names auditorily and professions visually. All three experiments revealed the same inverse priming effect with concordant test pairs associated with significantly slower classification judgements. Experiment 4 sought to establish if learning would be more efficient with supraliminal stimuli and found evidence that a different strategy is adopted when stimuli are consciously perceived. Finally, Experiment 5 replicated the unconscious cross-modal association achieved in Experiment 3 utilising non-linguistic stimuli. The results demonstrate the acquisition of novel cross-modal associations between stimuli which are not consciously perceived and thus challenge the global access hypothesis and those theories embracing it