2,718 research outputs found

    Influence of a Large Free Stream Disturbance Level on Dynamics of a Jet in a Cross Flow

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    An experiment to study the physical agents that are responsible for the jet turning into the streamwise direction, and the mixing of the jet and the cross stream fluid in the case of a jet in a cross flow is discussed

    Free stream turbulence and density ratio effects on the interaction region of a jet in a cross flow

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    Jets of low temperature air are introduced into the aft sections of gas turbine combustors for the purpose of cooling the high temperature gases and quenching the combustion reactions. Research studies, motivated by this complex flow field, have been executed by introducing a heated jet into the cross stream of a wind tunnel. The investigation by Kamotani and Greber stands as a prime example of such investigations and it serves as the principal reference for the present study. The low disturbance level of the cross stream, in their study and in similar research investigations, is compatible with an interest in identifying the basic features of this flow field. The influence of the prototypes' strongly disturbed cross flow is not, however, made apparent in these prior investigations

    Development of a temperature measurement system with application to a jet in a cross flow experiment

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    A temperature measurement system, which allows the simultaneous sampling of up to 80 separate thermocouples, was developed. The minimum resolution for the system corresponds to + or - 0.16 C per least significant bit of the A/D converter. The time constant values lambda, for each of the 64 thermocouples, were determined experimentally at 7 mps. Software routines were used to correct the measured temperatures for the effect of lambda for each thermocouple. The temperature measurement system was utilized to study the thermal field of a heated jet discharging perpendicularly into a low and a high disturbance level cross stream for a given momentum flux ratio and for three overheated values. The peak instantaneous temperatures reveal that strong molecular diffusion was operative. Various measures of the thermal field, for the disturbed case, suggest that the jet column remains relatively compact while being buffeted by the ambient turbulence field and that its penetration, into the cross wind, is inhibited by the presence of the strong disturbance field

    Methods for nanoparticle labeling of ricin and effect on toxicity

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    The unique optical properties associated with nanostructured materials that support the excitation of surface plasmons offer many new opportunities for the enhanced optical investigation of biological materials that pose a security threat. In particular, ricin is considered a significant bioterrorism risk due to its high toxicity combined with its ready availability as a byproduct in castor oil production. Therefore, the development of optical techniques capable of rapid on-site toxin detection with high molecular specificity and sensitivity continues to be of significant importance. Furthermore, understanding of the ricin cell entry and intracellular pathways remains poor due to a lack of suitable bioanalytical techniques. Initial work aimed at simultaneously tackling both these issues is described where different approaches for the nanoparticle labeling of ricin are investigated along with changes in ricin toxicity associated with the labeling process

    PATENTS, R&D AND LAG EFFECTS: EVIDENCE FROM FLEXIBLE METHODS FOR COUNT PANEL DATA ON MANUFACTURING FIRMS

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    Hausman, Hall and Griliches (1984) and Hall, Griliches and Hausman (1986) investigated whether there was a lag in the patent-R&D relationship for the U.S. manufacturing sector using 1970¿s data. They found that there was little evidence of anything but contemporaneous movement of patents and R&D. We reexamine this important issue employing new longitudinal patent data at the firm level for the U.S. manufacturing sector from 1982 to 1992. To address unique features of the data, we estimate various distributed lag and dynamic multiplicative panel count data models. The paper also develops a new class of count panel data models based on series expansion of the distribution of individual effects. The empirical analyses show that, although results are somewhat sensitive to different estimation methods, the contemporaneous relationship between patenting and R&D expenditures continues to be rather strong, accounting for over 60% of the total R&D elasticity. Regarding the lag structure of the patents-R&D relationship, we do find a significant lag in all empirical specifications. Moreover, the estimated lag effects are higher than have previously been found, suggesting that the contribution of R&D history to current patenting has increased from the 1970¿s to the 1980¿s.Innovative activity, Patents and R&D, Individual effects, count panel data methods.

    Redefining Faculty Workloads in a Physical Therapy Department: A Case Study

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    The purpose of this case study is to describe the creation and implementation of a sustainable workload model in the physical therapy department, as well as the outcomes resulting from that structure. Between 2002 and 2009, both scholarly productivity and faculty practice activity increased as a result of the redistribution of faculty efforts created by the new workload structure. This case demonstrates how the department has been able to successfully expand research and faculty practice while maintaining a high quality educational experience. The workload guidelines have enabled the collective core faculty to be productive in teaching, research/scholarship and service.

    A microfluidics tool for high-throughput, real-time multimodal imaging of nanoparticle-cell interactions

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    The increasing use of nanomaterials for biomedical applications has raised the need for efficient, robust and low-cost high-throughput assessment of nanotoxicity and cell-nanoparticle interactions. Microfluidics provides the tools for high-throughput single-cell functional monitoring, while gold nanorods have unique potential for intracellular tracking and can simultaneously be used as drug carriers. Presented here is a miniaturised platform that integrates these features with a multimodal approach to cell imaging. A microfluidic device allows for trapping of an array of singlecells, followed by the controlled delivery of nanoparticles into the cell array and subsequent real-time multimodal imaging of cellular interactions with functionalised nanoparticles. This system has been successfully used to assess cellnanoparticle interactions at the single-cell level
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