Structure in turbulent mixing layers and wakes using a chemical reaction

Plane turbulent mixing between two streams of water which contained dilute chemical reactants was studied in a new blow-down water tunnel. In a diffusion-limited reaction, a pH indicator, phenolphthalein, in one stream mixed and reacted with a base, sodium hydroxide, in the other stream to form a visible reaction product. The product was found to exist, as expected, in concentrated regions associated with the large, span-wise-coherent structures of the turbulence. A transition in the mixing was observed in which the aqueous mixing product increased by an order of magnitude. The transition is a consequence of the appearance and development of small-scale three-dimensional motions in the flow. Downstream of the transition, the amount of mixing product was independent of Reynolds number (for an order-of-magnitude increase in the latter) and at most only weakly dependent on Schmidt number

Structure and mixing of a transverse jet in incompressible flow

The flow field induced by a jet in incompressible cross-flow is analysed and the results compared with those obtained in a reacting water-jet experiment. It is argued that the axial vortex pair in the flow arises from the jet momentum normal to the free stream, the momentum flux being equivalent to a normal force, i.e. to a lift

A simple model of mixing and chemical reaction in a turbulent shear layer

Arguments are presented to show that the concept of gradient diffusion is inapplicable to mixing in turbulent shear layers. A new model is proposed for treating molecular mixing and chemical reaction in such flows at high Reynolds number. It is based upon the experimental observations that revealed the presence of coherent structures and that showed that fluid elements from the two streams are distributed unmixed throughout the layer by large-scale inviscid motions. The model incorporates features of the strained flame model and makes use of the Kolmogorov cascade in scales. Several model predictions differ markedly from those of diffusion models and suggest experiments for testing the two approaches

Core and Off-Core Processes in Systems Engineering

An emerging methodology of organizing systems-engineering plans is based on a concept of core and off-core processes or activities. This concept has emerged as a result of recognition of a risk in the traditional representation of systems-engineering plans by a Vee model alone, according to which a large system is decomposed into levels of smaller subsystems, then integrated through levels of increasing scope until the full system is constructed. Actual systems-engineering activity is more complicated, raising the possibility that the staff will become confused in the absence of plans which explain the nature and ordering of work beyond the traditional Vee model

Aerodynamics of vortex generators

An experimental and theoretical study was undertaken of the separation delay and dramatic boundary-layer thinning that can occur in vortex-generator installations. Wind tunnel measurements of the dynamic-pressure profile downstream of a vortex generator were found to compare under certain conditions with that downstream of a suction slit, while water-tunnel visualization studies of vortex-generator height and geometry suggested optimum configurations, and only a minor effect of base porosity. A series of progressively more complex inviscid flow models was developed to be applied to a 3-D integral boundary-layer code. This code predicted layer thinning downstream of the suction site of the vortex models, and other observed features. Thin-layer Navier-Stokes equations are now being used with the ultimate goal of clarifying the physical processes involved in vortex generator performance and developing calculational procedures capable of predicting it

Environmental stress alters genetic regulation of novelty seeking in vervet monkeys.

Considerable attention has been paid to identifying genetic influences and gene-environment interactions that increase vulnerability to environmental stressors, with promising but inconsistent results. A nonhuman primate model is presented here that allows assessment of genetic influences in response to a stressful life event for a behavioural trait with relevance for psychopathology. Genetic and environmental influences on free-choice novelty seeking behaviour were assessed in a pedigreed colony of vervet monkeys before and after relocation from a low stress to a higher stress environment. Heritability of novelty seeking scores, and genetic correlations within and between environments were conducted using variance components analysis. The results showed that novelty seeking was markedly inhibited in the higher stress environment, with effects persisting across a 2-year period for adults but not for juveniles. There were significant genetic contributions to novelty seeking scores in each year (h(2) = 0.35-0.43), with high genetic correlations within each environment (rhoG > 0.80) and a lower genetic correlation (rhoG = 0.35, non-significant) between environments. There were also significant genetic contributions to individual change scores from before to after the move (h(2) = 0.48). These results indicate that genetic regulation of novelty seeking was modified by the level of environmental stress, and they support a role for gene-environment interactions in a behavioural trait with relevance for mental health

Addressing Complexity in Laboratory Experiments: The Scaling of Dilute Multiphase Flows in Magmatic Systems.

The kinematic and dynamic scaling of dilute multiphase mixtures in magmatic systems is the only guarantee for the geological verisimilitude of laboratory experiments. We present scaling relations that can provide a more complete framework to scale dilute magmatic systems because they explicitly take into account the complexity caused by the feedback between particles (crystal, bubble, or pyroclast) and the continuous phase (liquid or gas). We consider three canonical igneous systems: magma chambers, volcanic plumes, and pyroclastic surges, and we provide estimates of the proposed scaling relations for published experiments on those systems. Dilute magmatic mixtures can display a range of distinct dynamical regimes that we characterize with a combination of average (Eulerian) properties and instantaneous (Lagrangian) variables. The Eulerian properties of the mixtures yield the Reynolds number (Re), which indicates the level of unsteadiness in the continuous phase. The Lagrangian acceleration of particles is a function of the viscous drag and gravity forces, and from these two forces are derived the Stokes number (ST) and the stability number (ΣT), two dimensionless numbers that describe the dynamic behavior of the particles within the mixture. The compilation of 17 experimental studies relevant for pyroclastic surges and volcanic plumes indicates that there is a need for experiments above the mixing transition (Re>104), and for scaling ST and ΣT. Among the particle dynamic regimes present in surges and plumes, some deserve special attention, such as the role of mesoscale structures on transport and sedimentary processes, or the consequences of the transition to turbulence on particle gathering and dispersal. The compilation of 7 experimental studies relevant to magma bodies indicates that in the laminar regime, crystals mostly follow the motion of the melt, and thus the physical state of the system can be approximated as single phase. In the transition to turbulence, magmas can feature spatially heterogeneous distributions of laminar regions and important velocity gradients. This heterogeneity has a strong potential for crystals sorting. In conclusion, the Re-ST-ΣT framework demonstrates that, despite numerous experimental studies on processes relevant to magmatic systems, some and perhaps most, geologically important parameter ranges still need to be addressed at the laboratory scale

Data Potential of Archaeological Deposits at the Chelan Station Site

The Chelan Station Site (45CH782/783), located along the Rocky Reach of the Columbia River, includes lithic and faunal artifacts buried beneath volcanic tephra from Mt. Mazama (6,830 BP). Artifacts were inadvertently discovered in buried soils within a secondary alluvial terrace during construction of a pipeline to supply water to the Beebe Springs Fish Hatchery. This thesis stems from participation in original field work and includes the author’s own models of early land forms and site formation. The study reviews the construction monitoring and archaeological testing of both sites, and documents the archaeological data potential early occupations of the vicinity. The stratigraphy of artifacts, tephra, alluvial sediment, and buried soils is summarized for a 1,212 m-long transect. People bearing tools related to the Old Cordilleran Tradition (cobble tools and leaf shaped points) colonized the region and fished for salmon and hunted large game in the vicinity between 9,190 ± 50 BP and 8,480 ± 40 BP. Stratigraphic models are created and schematic diagrams are used to summarize early site formation across five landforms on the terrace. Two buried soils include evidence of burning that probably represent human activity. Magnetic susceptibility measurements confirm the presence of buried organic layers and the influence of fire. All strata are iv best preserved in a deeper back-channel of the Columbia River. Artifacts are best represented at the bottom of profiles with less distinct strata on higher ground of the terrace scarp. Deeper strata in the back-channel, at first interpreted to represent tephra from Glacier Peak or Mt St. Helen’s, do not contain tephra. Results from Washington State University Geoanalytic Laboratory reveal feldspar and quartzite associated with alluvial layers from Columbia River floods bearing a unique sediment load. The site stratigraphy and models of site formation are compared with three other site investigations where the author has firsthand experience. Recommendations include: 1) nominating sites 45CH782 and 45CH783 to the National Register of Historic Places under significance criterion D, preparing a site specific historic properties treatment plan, and developing a state-wide database to aid management of buried soils as cultural features

Lacan\u27s critique of Freud\u27s case of Dora and the therapeutic action of working in the symbolic : a project based upon an independent investigation

This study was undertaken to determine the therapeutic action of working in the symbolic order. Lacan critiques psychoanalytic theory for reducing psychoanalysis to a therapy of the imaginary, thus ignoring the true significance of Freud\u27s discovery. A review of contemporary accounts of therapeutic action established interpretation, the clinical relationship, and the position of the analyst as key identifiers of a theory of therapeutic action. The case of Dora was utilized to identify Freud\u27s theory of therapeutic action. Lacan\u27s critique of Freud\u27s case in Intervention on Transference resulted in an explication of Lacan\u27s theory of therapeutic action, particularly in regards to the differentiation of the imaginary and the symbolic. The study clarified the significance of the difference between working in the symbolic rather than the imaginary order. It was found that Lacanian theory and practice place a distinctive focus on unconscious desire, alterity, structure, and fantasy. The findings suggest that Lacanian theory and practice offer a unique alternative to contemporary accounts of therapeutic action. As such it is hoped that Lacanian theory and practice will be better represented and utilized in the field of clinical social work

Facial expressions as social signals of the drill (Mandrillus leucophaeus)

I studied one aspect of the social behavior of the drill, Mandrillus leucophaeus: social communication by way of facial expressions. Eleven different facial expressions of nine captive drills were described and categorized. Of these expressions, three (grin, figure-eight, and lip-smack) were identified as being mainly affiliative, two (lip-flutter and yawn threat) as neutral and six (mock bite, open-mouth threat, head bob, bared-teeth threat, snarl and square-mouth) as aggressive. The square-mouth was unique to one individual, an adolescent male, possibly due to his undeveloped facial structure and his low rank. The behaviors were classified prior to and during the study and grouped into four categories: affiliative, neutral, submissive and aggressive. The actions preceding and following a facial expression helped determine its communication value. I determined that several of the drill expressions paralleled other nonhuman primate expressions. However, my results indicated a greater number of distinct expressions than has previously been reported in this species.California State University, Northridge. Department of Biology.Includes bibliographical references (leaves 110-113