Optimization of Wastewater Design Using Genetic Algorithms

Recently, at Brigham Young University, graduate students in the Environmental Engineering Laboratory have been exploring the possibility of using Genetic Algorithms for the optimization of wastewater treatment design. This research applies the IA WRC ASM no. 1 model for solving a four-stage Bardenpho process system using a tournament style selection genetic algorithm. The mathematical model was solved in Maple, and programmed in C++ using a Gauss-Seidel iterative method. Final results will be available in June 2003

Er udvikling overhovedet meningen? Om det psykosociale arbejdes betingelser og muligheder i socialpsykiatrien

Vor deltagelse i en socialpsykiatrisk boenhed har givet os anledning til at reflektere over den udfordring, det er, at omsætte gode intentioner til en egentlig udviklende socialpsykiatrisk praksis og, hvorfor dette projekt er vanskeligt at realisere. Brugerinddragelse og recovery står øverst på dagsordenen hos de fleste so- cialforvaltninger i de her år. Men hvordan skabes og understøttes brugerinddragelse og recovery side om side med et neoliberalistisk tankegods i form af individualisering og isole- ring af problemstillingerne, managementlogik- ker og økonomisk rationalisering? Vor erfaring med indarbejdning af netop brugerinddragelse og elementer af recovery- tanken (ved genetablering af solide forbindel- ser til samfundet og udvidelse af handleevnen; med henblik på at gøre videre institutiona- lisering unødvendig) har været, at så længe managementlogikkerne og den økonomiske ra- tionalisering ikke udfordres eller anfægtes, så er der åbenhed for både brugerinddragelse og recovery-orienteret arbejde. Vore erfaringer giver anledning til at reflektere over, hvorvidt vi har at gøre med et system af sociale hjæl- peforanstaltninger, der, helt selvmodsigende med sine indbyggede logikker, forhindrer det egentlige formål – nemlig at hjælpe mennesker i en udsat og marginaliseret position til en god og meningsfuld tilværelse

Imaging Performance of Quantitative Transmission Ultrasound

Quantitative Transmission Ultrasound (QTUS) is a tomographic transmission ultrasound modality that is capable of generating 3D speed-of-sound maps of objects in the field of view. It performs this measurement by propagating a plane wave through the medium from a transmitter on one side of a water tank to a high resolution receiver on the opposite side. This information is then used via inverse scattering to compute a speed map. In addition, the presence of reflection transducers allows the creation of a high resolution, spatially compounded reflection map that is natively coregistered to the speed map. A prototype QTUS system was evaluated for measurement and geometric accuracy as well as for the ability to correctly determine speed of sound

Accelerated Testing Validation

The DOE Fuel Cell technical team recommended ASTs were performed on 2 different MEAs (designated P5 and HD6) from Ballard Power Systems. These MEAs were also incorporated into stacks and operated in fuel cell bus modules that were either operated in the field (three P5 buses) in Hamburg, or on an Orange county transit authority drive cycle in the laboratory (HD6 bus module). Qualitative agreement was found in the degradation mechanisms and rates observed in the AST and in the field. The HD6 based MEAs exhibited lower voltage degradation rates (due to catalyst corrosion) and slower membrane degradation rates in the field as reflected by their superior performance in the high potential hold and open-circuit potential AST tests. The quantitative correlation of the degradation rates will have to take into account the various stressors in the field including temperature, relative humidity, start/stops and voltage cycles

Measuring anisotropic resistivity of single crystals using the van der Pauw technique

Anisotropy in properties of materials is important in materials science and solid-state physics. Measurement of the full resistivity tensor of crystals using the standard four-point method with bar shaped samples requires many measurements and may be inaccurate due to misalignment of the bars along crystallographic directions. Here an approach to extracting the resistivity tensor using van der Pauw measurements is presented. This reduces the number of required measurements. The theory of the van der Pauw method is extended to extract the tensor from parallelogram shaped samples with known geometry. Methods to extract the tensor for both known and unknown principal axis orientation are presented for broad applicability to single crystals. Numerical simulations of errors are presented to quantify error sources. Several benchmark experiments are performed on isotropic graphite samples to verify the internal consistency of the developed theory, test experimental precision, and characterize error sources. The presented methods are applied to a RuSb_2 single crystal at room temperature and the results are discussed based on the error source analysis. Temperature resolved resistivities along the a and b directions are finally reported and briefly discussed

Phase transition enhanced thermoelectric figure-of-merit in copper chalcogenides

While thermoelectric materials can be used for solid state cooling, waste heat recovery, and solar electricity generation, low values of the thermoelectric figure of merit, zT, have led to an efficiency too low for widespread use. Thermoelectric effects are characterized by the Seebeck coefficient or thermopower, which is related to the entropy associated with charge transport. For example, coupling spin entropy with the presence of charge carriers has enabled the enhancement of zT in cobalt oxides. We demonstrate that the coupling of a continuous phase transition to carrier transport in Cu 2Se over a broad (360–410 K) temperature range results in a dramatic peak in thermopower, an increase in phonon and electron scattering, and a corresponding doubling of zT (to 0.7 at 406 K), and a similar but larger increase over a wider temperature range in the zT of Cu 1.97 Ag .03Se (almost 1.0 at 400 K). The use of structural entropy for enhanced thermopower could lead to new engineering approaches for thermoelectric materials with high zT and new green applications for thermoelectrics

A diagnostic illusory? : The case of distinguishing between "vegetative" and "minimally conscious" states

Throughout affluent societies there are growing numbers of people who survive severe brain injuries only to be left with long-term chronic disorders of consciousness. This patient group who exist betwixt and between life and death are variously diagnosed as in 'comatose', 'vegetative', and, more recently, 'minimally conscious' states. Drawing on a nascent body of sociological work in this field and developments in the sociology of diagnosis in concert with Bauman's thesis of 'ambivalence' and Turner's work on 'liminality', this article proposes a concept we label as diagnostic illusory in order to capture the ambiguities, nuanced complexities and tensions that the biomedical imperative to name and classify these patients give rise to. Our concept emerged through a reading of debates within medical journals alongside an analysis of qualitative data generated by way of a study of accounts of those close to patients: primarily relatives (N=51); neurologists (N=4); lawyers (N=2); and others (N=5) involved in their health care in the UK

Accelerating Innovation in the Creation of Biovalue : The Cell and Gene Therapy Catapult

The field of regenerative medicine (RM) has considerable therapeutic promise that is proving difficult to realize. As a result, governments have supported the establishment of intermediary agencies to “accelerate” innovation. This paper examines in detail one such agency, the UK's Cell and Gene Therapy Catapult (CGTC). We describe CGTC’s role as an accelerator agency and its value-narrative, which combines both “health and wealth.” Drawing on the notion of socio-technical imaginaries, we unpack the tensions within this narrative and its instantiation as the CGTC cell therapy infrastructure is built and engages with other agencies, some of which have different priorities and roles to play within the RM field