Joseph Katz - US grants

1. To determine the mechanism of the stimulating effect of amino acids on glycogen synthesis in liver cells, and the stimulation of glucose uptake and lipogenesis in quail hepatocytes, the effect of alanine and glutamine on Fructose 2,6P and other phosphorylated intermediates and Krebs cycle acids will be determined, using a bacterial luciferase assay. 2. The role of malic acid as a donor of NADPH for reductive biosynthesis of fatty acids in quail hepatocytes will be studied. Methyl esters of dicarboxylic acids have been shown to penetrate intact liver hepatocytes. 1-methyl-2-3H-malate will be synthesized and incubated with quail hepatocytes and tritium incorporation into water and lipid determined. Monomethyl tartronic acid, a penetrating inhibitor of malic enzyme will be prepared and its effect on lipogenesis studied. 3. The distribution and kinetics of glucokinase of quail liver will be studied. 4. The heterogeneity of mitochondria and endoplasmic reticulum of liver cells will be studied. The nature of the bonds holding together the mitochondrial-reticular cytostructure will be explored, using hepatocytes from which the plasma membrane was removed with digitonin.

We plan to study glucose metabolism and lipogenesis in isolated hepatocytes of Japanese quail (Coutournix coutournix). This is a continuation of our current studies with liver cells of egglaying quail. These cells have a very high metabolic rate and incorporate lactate extensively into fatty acid. Glucose is a poor substrate for lipogenesis. We discovered that physiological concentrations of alanine and several other amino acids stimulate many fold the uptake of glucose and increase its contribution to fatty acid carbon by 400 to 800%. The amino acids also depress gluconeogenesis from lactate and redirect the carbon flux into fatty acid. Our plans are: (1) to study the mechanism of the amino acid effect to determine its site of action, whether it causes a covalent modification of rate limiting enzyme(s) or whether the amino acids serve as precursors for an allosteric activator; (2) Birds including quail have no pentose cycle, and it is not known how NADPH for fatty acid synthesis is generated. We will determine the source of the reducing equivalents and evaluate the role of malic enzyme and isocitric dehydrogenase for transhydrogenation and NADPH generation; (3) It is generally believed that birds lack a high KM hexokinase (glucokinase). We have established however, the presence of an active glucokinase, with properties different from that in rats. the enzyme is membrane bound. We will determine the nature of the membrane (most likely cell plasma membrane) and will study the kinetics of glucokinase and its regulatory role in glucose uptake. Other enzymes of glycolysis and lipogenesis in quail liver will be examined. (4) To account for the large increase in lipogenesis which accompanies the onset of egglaying, we will compare the profile of glycolytic and lipogenic enzymes in nonlaying and egglaying quail. The kinetics of glucose and lactate labelled with 14C and 3H will be studied in vivo in both types of bird, and the relative contribution of glucose and non-glucose carbon to fatty acids will be evaluated.

The effect of alcohol intake on the operation of the pentose cycle and NADPH generation will be studied in rats in vivo and in vitro. Chronic alcoholic rats will be used when "drunk" (high blood alcohol) and "sober," with control diet substituted overnight for that with ethanol. Methods to calculate the pentose cycle developed by us will be used. For in vivo studies rats will be infused with 2-3H glucose and 1-14C acetate, and glucose isolated. The formation of NADPH will be calculated from the turnover of 2-3H glucose and the distribution of 14C in carbons 1,2 and 3 of glucose. Experiments in vitro will be with isolated hepatocytes from chronic alcoholic "drunk" and "sober" and control rats. The cells will be incubated with 2-3h glucose and 1-14C galactose, and the effect of ethanol on the pathways of glucose-6P and NADPH yield will be determined by novel procedures. The role of NADPH production by malic enzyme will be explored. The source of NADPH for the hydroxylation of aniline and hexobarbitol in alcoholic and control rats will be examined.

The proposal consists of two projects: (A) The Precursors of Glycogen Several investigators including myself have presented evidence that the major precursors of hepatic glycogen are 3-carbon precursors, rather than glucose. There is some contrary evidence and the issue is controversial. A novel approach, using 3HOH incorporation, to resolve the problem is proposed. 3HOH will be administered in vivo and the distribution of tritium in glucose will be determined. 3HOH yield in C-2 should represent glycogen synthesis from all precursors, including glucose, whereas that on C-6, synthesis from pyruvate. The tritium pattern in circulating glucose, liver and muscle glycogen and lactate will be determined. The effects of diet, diabetes and hormones on the labelling pattern will be determined. (B) Determination of Gluconeogenesis in vivo Oxalacetate is a shared intermediate for synthesis of phosphoenolpyruvate and the tricarboxylic acid cycle. Therefore, in the conversion of pyruvate to PEP, the carbon of PEP is diluted by carbon from acetyl CoA and CO2. To calculate the contribution of alanine and lactate to gluconeogenesis, it is essential to evaluate this dilution. A theory to obtain this dilution is presented. Two labelled species, such as 1-13C and 2-14C alanine or lactate, are required to calculate the true rate of gluconeogenesis. Experiments with the administration of two tracers (13C and 14C) and methods to calculate the true contribution of alanine and lactate to glucose production are planned. Methods to quantitate gluconeogenesis from the incorporation of 14CO2 and 14C acetate will be examined. Fed, starved, diabetic and hormone-treated animals will be used.

The proposal consists of two projects: (A) The Precursors of Glycogen Several investigators including myself have presented evidence that the major precursors of hepatic glycogen are 3-carbon precursors, rather than glucose. There is some contrary evidence and the issue is controversial. A novel approach, using 3HOH incorporation, to resolve the problem is proposed. 3HOH will be administered in vivo and the distribution of tritium in glucose will be determined. 3HOH yield in C-2 should represent glycogen synthesis from all precursors, including glucose, whereas that on C-6, synthesis from pyruvate. The tritium pattern in circulating glucose, liver and muscle glycogen and lactate will be determined. The effects of diet, diabetes and hormones on the labelling pattern will be determined. (B) Determination of Gluconeogenesis in vivo Oxalacetate is a shared intermediate for synthesis of phosphoenolpyruvate and the tricarboxylic acid cycle. Therefore, in the conversion of pyruvate to PEP, the carbon of PEP is diluted by carbon from acetyl CoA and CO2. To calculate the contribution of alanine and lactate to gluconeogenesis, it is essential to evaluate this dilution. A theory to obtain this dilution is presented. Two labelled species, such as 1-13C and 2-14C alanine or lactate, are required to calculate the true rate of gluconeogenesis. Experiments with the administration of two tracers (13C and 14C) and methods to calculate the true contribution of alanine and lactate to glucose production are planned. Methods to quantitate gluconeogenesis from the incorporation of 14CO2 and 14C acetate will be examined. Fed, starved, diabetic and hormone-treated animals will be used.

The wind-tunnel laboratories used in this institution's aerospace engineering program are updated and improved, exposing students to modern computer-aided wind-tunnel technology. A mini- computer, with graphic capabilities, is interfaced to the wind- tunnels so that students can carry on experiments using real-time data acquisition and analysis. This modernization of equipment and analytic techniques exposes students to laboratory computer technology, enhances the study of experimental/analytical fluid dynamics and better prepares students for the aerospace industry and graduate study. This award is being matched by an equal sum from the grantee.

This research will measure rates of homogeneous nucleation for a variety of vapors at various temperatures and supersaturations using a thermal diffusion cloud chamber. The influence of photo-induced ions of controlled sign and concentration on the nucleation rate also will be measured. The theory for thermal diffusion cloud chambers will be extended to account for vapor depletion and latent heat release associated with droplet formation and growth in order to allow data interpretation at significantly higher nucleation rates than obtained heretofore by this technique. Acquisition of an extensive and consistent data base should enable a critical test of theories for homogeneous nucleation rates which sometimes differ from experimental rates by many orders of magnitude and will guide modifications where necessary to these theories. Nucleation is an important phenomenon in a wide variety of engineering and environmental applications.

Calcite (CaCO3) is one of the most prevalent of boiler and heat exchanger scale. Recent work has shown that trace concentrations of divalent iron (Fe2+) very strongly inhibit the growth of CaC03, suggesting that iron of the appropriate form and in sufficient concentration can lead to a significant reduction in the amount and tenacity of such scale deposits. It is proposed to examine how iron and other metal cations affect the nucleation and growth of a variety of scale-forming carbonate minerals, and how various solution parameters enhance or suppress crystallization. A model will be developed to predict carbonate crystal growth inhibition, and electrolytic and magnetic means of introducing the metal cations into solution will be examined. The build up of scale deposits inside cooling water pipes and boilers is a multimillion dollar problem. Scale significantly reduces heat transfer efficiency and can lead to blockage of water flow passages. Understanding the mechanisms by which metal ions inhibit crystal nucleation and growth can lead to cost effective means of maintaining peak performance of heat exchange equipment.

This award supports Joseph L. Katz of Johns Hopkins University for collaborative research in chemical engineering with Professor Friedrich Hensel of Phillips University in Marburg, Germany. They are cooperating in a study that involves the use of upward thermal diffusion chambers to measure the homogeneous nucleation of cesium and other metal vapors. Their research plan exploits the complementary strengths of the two research groups. The German group led by Dr. Hensel is well known for their research on the metal-insulator transition and other properties of metal vapors. They have state-of-the-art facilities where they are actively studying supersaturated mercury vapor. Dr. Katz and his group are expert in the use of the diffusion cloud chamber and in nucleation theory. They have a very active program using upward thermal diffusion cloud chambers for the study of homogeneous and other nucleations. Most of the experimental work will be done in Marburg, with some data analysis and other support going on in Maryland. Reciprocal visits of members of the two research groups will facilitate this joint work. Nucleation processes are extremely widespread in the natural world as well as in the laboratory. However, our ability to predict the conditions that cause nucleation and the rate at which it occurs in typical processes is almost non-existent. Homogeneous nucleation of a liquid from its supersaturated vapor is particularly amenable to theoretical and experimental study. The nucleation properties of metals are quite different from those of non-metals, and they are of growing importance as technologies develop to produce and use novel alloys or to use known metals in novel ways.

Glycogen in liver may be synthesized either directly from glucose or indirectly from lactate and alanine, which are cleavage products of glucose in nonhepatic tissues and which are returned to liver. We are developing methods to measure the contribution of these pathways to glycogen in the intact animal (rat) by using radioactive and nonradioactive tracers. The radioactive tracer used here is water labeled with tritium (3HOH). The incorporation of labeled hydrogen on carbons 2 and 6 of glucose provides an estimate of these pathways that is much more reliable than with 14C labeled substrates. Another method to measure the pathways of glycogen is by using nonradioactive carbon (13C). Glucose labeled uniformly with 13C (U-13C) will be infused intragastrically in rats. Liver glycogen will be isolated and assayed by gas liquid-mass spectroscopy to obtain the distribution of masses from 181 to 186 (1 to 6 labeled carbons per molecule). The ratio of glucose of mass 186 to that of all labeled molecules provides an estimation of the direct pathway. This method also does not depend on the specific activity of precursors and attainment of steady state. The use of labeled substrates and mass spectroscopy to study glycogen and glucose synthesis and the operation of the Krebs cycle will be explored. The value of the use of nonradioactive tracers such as 13C is that ultimately these procedures can be applied to humans without risks due to radioaction damage.

Abstract Joseph L. Katz Johns Hopkins University CTS-9626661 The goal of this continuing research project is to provide a better understanding of nucleation processes, and to allow one to make accurate quantitative predictions. The research focuses on three complementary fields of investigation; ion-induced nucleation, homogeneous nucleation of metal vapors, and heterogeneous nucleation of water vapor onto uniform surfaces. Efforts in ion-induced nucleation have resulted in the development of a method for measuring nucleation rates under conditions where all the important variables (supersaturation, temperature, and ion density) are accurately measurable and all can be varied. Initial measurements on n-Nonane have been made. Measurements now will be made on several substances for which ions have a much larger nucleation propensity. These will begin with substances with significant dipole moments (1-Pentanol as well as 1-Butanol and 1-Hexanol), and will be followed by measurements on substances with significant quadrupole moments (Benzene, p-Xylene). A second major effort is the homogeneous nucleation of metal vapors. Metals in their dilute vapor state are non-metallic. Thus there has to be a non-metal to metal transition which is a function of cluster size. Nucleation studies of metal vapors enable the study of this size dependent non-metal to metal transition and also the testing of the validity of nucleation theories when they are applied to a class of substances which are very different from any studied until now. This part of the project involves collaboration with a research group in Marburg, Germany, and to date has focused on the homogeneous nucleation of Cesium vapor. Results obtained thus far suggest that a smooth non-metal to metal transition is being observed. These measurements will be extended to higher temperatures, since critical cluster sizes then will be much larger and thus closer to being fully metallic. The homogeneous nucleation of Rubidium then wil l be investigated and will be followed by measurements on Cadmium and Mercury, substances which are known to have more sharply size-dependent non-metal to metal transitions. The third major effort is the heterogeneous nucleation of water vapor onto the surface of water insoluble liquids. By investigating heterogeneous nucleation onto a liquid substrate one takes advantage of the uniformity of the substrate's surface properties, thus avoiding many of the uncertainties encountered in heterogeneous nucleation onto solid surfaces. Even more important, all surface free energies needed to characterize this process (the interfacial tension between the condensing liquid and the liquid that it is condensing onto, and the surface tension of each liquid) are experimentally measurable. The critical supersaturations required for water nucleation onto Dodecane and Hexadecane will be determined and compared to theory.

Glycogen in liver may be synthesized either directly from glucose or indirectly from lactate and alanine, which are cleavage products of glucose in nonhepatic tissues and which are returned to liver. We are developing methods to measure the contribution of these pathways to glycogen in the intact animal (rat) by using radioactive and nonradioactive tracers. The radioactive tracer used here is water labeled with tritium (3HOH). The incorporation of labeled hydrogen on carbons 2 and 6 of glucose provides an estimate of these pathways that is much more reliable than with 14C labeled substrates. Another method to measure the pathways of glycogen is by using nonradioactive carbon (13C). Glucose labeled uniformly with 13C (U-13C) will be infused intragastrically in rats. Liver glycogen will be isolated and assayed by gas liquid-mass spectroscopy to obtain the distribution of masses from 181 to 186 (1 to 6 labeled carbons per molecule). The ratio of glucose of mass 186 to that of all labeled molecules provides an estimation of the direct pathway. This method also does not depend on the specific activity of precursors and attainment of steady state. The use of labeled substrates and mass spectroscopy to study glycogen and glucose synthesis and the operation of the Krebs cycle will be explored. The value of the use of nonradioactive tracers such as 13C is that ultimately these procedures can be applied to humans without risks due to radioaction damage.

The project is intended to investigate the inhibiting effects of iron and other metal cations on the growth of scale forming minerals; to determine the specific mechanisms of crystal growth inhibition by metal cations and construct a predictive model; and to examine how temperature influences the effectiveness as well as the mechanism of calcite growth inhibition; and to examine whether metal cations can outperform chemical inhibitors currently in use. How iron and other metal cations affect growth of calcium sulphate, another scale forming mineral, will also be investigated.

9320153 Katz Under and SGER award an attempt will be made to solve the problem of nozzle wear in abrasive slurry jet cutting operations by lubricating the interior nozzle surface from a pressurized reservoir located on the outside of the porous nozzle material. A two dimensional apparatus will be constructed to allow detailed observation of individual particle movements as an aid in determining optimal process and design parameters. ***

ABSTRACT Proposal Number: CTS-9706701 Principal Investigator: Katz The present study is an integrated experimental and numerical effort to determine and explain the conditions for the onset of cavitation in high-Reynolds-number jets. Experimentally, high resolution PIV will be used to measure the unsteady velocity distribution within primary vortices, from which one can extract the vorticity and strain. Holography and video photography will be used to determine the motion of artificially-introduced microscopic seed bubbles. The pressure field within the primary eddies will be determined using microscopic bubbles as pressure sensors. The conditions for cavitation inception within observed secondary vortices (ribs) will be used to estimate the corresponding pressure minima. Computationally, Lagrangian simulations of primary structures will be conducted, with initial and boundary conditions provided by the experiments. The simulations will be first validated by comparison with the experimental results, and then used to analyze the impact of slenderness ratio on the pressure field within primary vortices and the strain field that they induce. The measured strain field will be used in direct numerical simulation of the rollup of streamwise vorticity perturbations in the braids. The experimentally-determined pressure minima within the ribs can then be used to select the appropriate streamwise vorticity perturbation levels. This combined approach will enable a mapping the pressure distribution within the near field of the jet.

9726626 Katz This award supports the participation of American scientists and engineers in a U.S.-Japan seminar on Abnormal Flow Phenomena in Turbomachines -- From Avoidance to Suppression and Control, to be held in Osaka, Japan from October 26-29, l998. The co-organizers are Professors Joseph Katz of Johns Hopkins University and Oshinobu Tsujimoto of Osaka University in Japan. The seminar will focus on the underlying flow mechanisms, available means to detect, compute and measure them, as well as existing and potential future effective countermeasures for them. Turbomachines are being used in increasingly more severe and demanding conditions in order to meet higher performance requirements and a wider range of applications. Under such conditions, various kinds of "abnormal" flow phenomena, such as rotating cavitation, rotating stall, surge, and massive flow separation occur. Besides having adverse effects on the performance and causing increased levels of vibrations and noise, these abnormal phenomena can and do regularly lead to component and system failures. Thus, in addition to meeting conventional design targets, such as improvements in the performance and efficiency, it is becoming increasingly important to understand the underlying mechanisms causing these abnormal phenomena and develop effective counter-measures against them. The participants will develop clear identification of the dominating flow phenomena and recommended strategies for avoidance, suppression and control. The U.S. researchers are experienced in theoretical, computational and experimental research tools while the Japanese have expertise in the fundamental and practical aspects of flows. The seminar brings together researchers from academia, industry and government. In addition, postdoctoral researchers will be included. The exchange of ideas and data with Japanese experts in this field will enable U.S. participants to advance their own work, and will set the stage for fu ture collaborative projects. ***

This work combines instrument development and scientific observations
and seeks to apply a proven laboratory technique to the observation of
turbulence in the coastal ocean. A Particle Imagery Velocimetry (PIV) instrument will be deployed on an extensible platform resting
on the sea-floor in coastal waters. After testing, the device will
be deployed in 15m of water at the LEO-15 site and used to repeatedly
measure the flow field over an area of from 0.25 to 0.5 m^2. The resulting data will be used to examine various properties of turbulence in the coastal ocean and its dependence on environmental
parameters such as stratification, wave state and macroscopic shear.
Additional data will be collected from the instrument suite already
in place at LEO-15 in order to characterize the environmental parameters. Separate deployments during late spring and fall will allow the PIs to study turbulence in different degrees of stratification.

Abstract
CTS-0079674
J. Katz, Johns Hopkins University

The objective of this project is to develop and implement a large scale Holographic Particle Image Velocimetry (HPIV) system for measuring complex turbulent flows. The data will be used for addressing fundamental turbulence modeling questions. The system will enable measurements of the instantaneous, three-dimensional velocity distribution over sample volumes of up to 25x25x25 cm^3, at an unprecedented resolution in scale, with arrays of 500x500x500, 3-D velocity vectors. Efficient and high speed processing tools will enable analysis of many holograms.

Two main avenues of turbulence research provide motivation: i) scaling dynamics and statistical geometry of velocity increments in high Reynolds number turbulent flows, and ii) relationships between large and small scales in turbulence and their implications for subgird-scale modeling for Large Eddy Simulations (LES). The 3-D data will enable the PI and his colleagues to address the anomalous scaling behavior of high order structure functions that significantly deviate from Kolmogorov's predictions; Turbulence modeling for LES must be based on understanding of the interactions among turbulent motions at various length-scales. Such understanding requires data consisting of well-resolved velocity fields that can be the filtered to obtain the subgrid scale stresses, filtered velocity and its gradients.

Development and improvements to this technology would eventually make it available to an entire community of researchers in a wide range of fields where transport phenomena are of significance. Included are communities involved in fundamental and applied fluid mechanics, multiphase flows involving transport of bubbles, particles and droplets as well as environmental flows, such as sediment transport, atmospheric sciences (turbulence and particle transport) and oceanography flow, particles and plankton dynamics, etc.).

9909170
Katz

This ocean sciences technology development project builds on previous work to develop and test a submersible holographic camera system using lasers to produce holograms, from which the motion and distribution of small particles can be studied. A submersible "holocamera" system for recording in-situ holograms in the ocean presently operates in an in-line mode utilizing a ruby laser as its light source. It is powered by onboard batteries and is controlled via two fiber optic cables, which also provide real time data from other onboard environmental sensors. The system is designed to minimize the effect the system has on the sampled water volume. The present effort focuses on enhancing the performance of the holocamera and continuing the development of hologram analysis procedures. Holography is a unique tool that can provide the instantaneous location of microscopic particles over a large sample volume as well as the shape, size and orientation of each particle. A series of holograms can also be used to determine the full 3 -D velocity field of the liquid in that sample volume and the relative velocities of larger particles.

The data analysis procedure consists of reconstructing a recorded hologram to create a 3 - D frozen image of the original sample volume. By scanning the reconstructed image at high magnification, one can observe and measure desired details down to less than 10 mm within a sample volume of about 1000 cm3. Work will be undertaken to automate and improve the efficiency of the analysis procedures by incorporating and developing software tools that will perform 1) image enhancement using a variety of histogram-based, non-linear and morphological filters; 2) particle detection involving use of blob analysis subroutines; and 3) particle classification based on size and shape. A further enhancement will provide the capability for Holographic Particle Image Velocimetry by providing the holocamera with a separate, off-axis reference beam, and a spatial, high pass filter inserted between the sample volume and the film.

The ability to measure the 3-D liquid velocity distribution in the ocean and the relative motion of selected particles will be developed using methods used for laboratory applications where the liquid flow field is measured using the displacement of small particles. In situ methods will be developed to obtain all three velocity components from a single hologram by determining the axial displacement of particles accurately using their exact location in space (particle tracking); and by using the continuity equation that enables computation of the axial component from the spatial distribution of the other two. Methods to address the overlap problem for in-line holography and for off-axis holography are proposed.

Field tests will be performed in conjunction with investigators from Harbor Branch Oceanographic Institute. Their research requires data on the local shear strains (i.e. 3 - D velocity distribution) in the scale of planktonic organisms as well as correlation between copepod abundance and marine snow and/or other resource abundance. Both can be simultaneously provided by the holocamera. This sensor could be applied to other physical and biological oceanographic problems such as small scale turbulence, microscale patchiness of organisms, capture of food particles, and describing the size and motion of bubbles including those smaller than multi-frequency acoustical techniques can measure.

CTS-0095917
J. Katz, Johns Hopkins University

The goal of this proposal is the determination of the critical conditions for the onset of cavitation in high Reynolds number turbulent boundary layers and shear flows. This is an important problem in industrial applications involving flow of liquids. To accomplish this goal, it is proposed to use new experimental techniques including triple-exposure 2-D PIV and 3-D Holographic PIV to measure the instantaneous pressure and velocity fields simultaneously. The experimental results will be used to guide and validate the development of numerical codes for the prediction of the critical conditions for cavitation inception.

0119903
Parlange
The objective of the proposed research is to focus on the measurement of the emission and transport of biological aerosols (focusing on pollens) in the atmosphere. Several instruments that cover the size range of microns for the particles themselves to particulate dispersal over many kilometers will be developed. The behavior of individual pollen particles and the emission of pollen from the plant will be observed and modeled. At the larger scales, particulate dispersal will be studied in a wind tunnel and in field studies, and the experimental results will be used to refine large eddy simulation models. The field studies will be carried out at four sites in the Chesapeake Bay region. Pollen transport is of interest because of species cross-fertilization and genetic diversity concerns that have arisen due to human disruption of the natural landscape, as well as concerns about transport distances of genetically altered pollens.

Measurements of Turbulence and flow Structure in the Water Column of the Coastal Ocean using PIV
Thomas Osborn and Joseph Katz
John Hopkins University

A novel and unique measurement system will be deployed to obtain measurements of oceanic turbulence. A submersible PIV system will be used during 3 campaigns at SABSOON, a coastal observatory in the South Atlantic Bight, to measure turbulence and mean flow characteristics in the bottom 10 m of the water column and to compare these to stratification, wave climate, and circulation. Reynolds stresses, dissipation, production, transport, and buoyancy flux will be related to elevation, mean velocity distribution, shear, stratification, Richardson number, and wave phase. When and where a local balance between production, dissipation, and buoyancy flux holds will be explored. The correlation, or lack thereof, between turbulent and wave stresses will be investigated. The origin of gusts will be characterized. In the context of Large Eddy Simulation (LES) modeling, subgrid scale (SGS) turbulent stresses will be compared to typical parameterizations. Wave-turbulence separation will be performed using a version of the Trowbridge technique.

0211625 Parlange The purpose of the research is to address questions on the particle transport from the World Trade Center (WTC) Site through the deployment of state-of-the-art instrumentation to measure the emission and resuspension of particles into the atmosphere It is planned to conduct the study over a ten-day intensive field observation period at the WTC site and the surrounding region of the greater New York City area to measure the flux of particles from the site and the vertical and horizontal extent of the aerosol plume.
At the site, a combination of turbulence sensors, including Particle Image Velocimetry (PIV), Holographic PIV and sonic anemometers mounted on a telescopic profiling tower to continually measure the shear stress and the concentration and flux profiles of p[articles from the surface up to 10 m. above the site.
A scanning elastic lidar system will be deployed to measure at high resolution (1.5 m.) the relative concentration of particles in the lower atmosphere (range up to 7 km.). The lidar will be deployed both near the site and at sites to be identified in the greater NYC area.
The lidar system will be calibrated using the concentration measurements obtained from the PIV systems.
An analysis of the field data collected will be conducted to identify relationships between weather conditions (e.g., wind shear stress, sensible heat flux) and the magnitude of the surface flux of particles and the extent of the transport into the atmosphere. ***

This project was submitted under the EU-US Cooperative Activity on the Ecology and Oceanography of Harmful Algae. The U.S. PIs will join colleagues from France, Ireland, Spain and UK to study the physics and biology of thin layers with concentrated Harmful Algal Bloom (HAB). Serious problems in Europe are caused by contamination of farmed shellfish with Diarrheic Shellfish Poisoning (DSP) toxins produced by the dinoflagellate genus Dinophysis. The existence of thin layers with high Dinophysis concentration has come to light recently, but the information is sporadic because the layers can be present at any depth, and due to sampling difficulties with standard instruments. In the case of Dinophysis, the concentration does not depend solely on nutrition, but also on interactions between physics, life cycle and behavior. This study will determine the hydrodynamic (e.g. local flow structure, turbulence, stratification, small gyres and pycnoclines), biological (e.g. growth, nutrition and mortality) and chemical environment leading to the build up, maintenance and population dynamics of Dinophysis in thin layers. The field tests will take place under a variety of hydrodynamic regimes in the Rias of Galicia (NWSpain), the estuarine plume zones of the Atlantic coast of France, and in the bays of southwestern Ireland. All are shellfish production areas with history of harvest closures due to contamination with DSP toxins. The Johns Hopkins group will focus on small-scale biophysical and particle-particle interactions. By deploying a submersible holocamera, augmented with a digital holographic cinematography, they will observe and measure processes and interactions occurring at the critical scales of 10 mm to 10 cm. Automated data analysis tools will enable the investigators to process a large database under various conditions that will be used for parameterizing the behavior of Dinophysis. The results will include: i. The spatial and size distributions of different classes of particles. Particles larger than 10 mm are detected, and shapes can be defined in particles larger than 30 mm. ii. The nearest neighbor distance (NNS) within the same species, and between species, including predators and prey; iii. The instantaneous 3-D velocity distributions within the sample volume, which is used for calculating the local velocity, strain rate, vorticity, dissipation rate and turbulence intensity; iv. The swimming behavior (speed, trajectory, direction) of Dinophysis in its local environment; v. Direct observations on behavior, feeding and grazing of Dinophysis; vi. Conditional statistics of concentration, NNS and behavior based on local physical and biological parameters;

Intellectual Merit: Progress in understanding of population dynamics of different phytoplankton species, including Dinophysis, requires detailed knowledge of their in-situ concentrations, behavior, and biophysical interactions. This project will deploy a new but proven/developed technology in the ocean in order to obtain detailed and unique insight on the interaction of dinoflagellates with their local biophysical environments. The results will illuminate processes affecting the formation and maintenance of thin layers containing Dinophysis.

Broader Impacts.
Socio-Economic Issues: HAB adversely affect health, tourism, fisheries and food production in the coastal ocean, causing closure of fisheries, illness and even death. This project will obtain essential information to develop such understanding of the importance of bio-physical mechanisms in the formation of some HABs.
Education of future Scientists: Studies of biophysical interactions in the ocean require background in biology, fluid mechanics, and instrumentation. This project will support one such student in an interdisciplinary training program.

This project continues our effort to measure the flow structure and turbulence in the bottom 10 m of the water column of the coastal ocean, and study their dependence on elevation, circulation, wave field, bottom topography and stratification. The turbulence measurements were performed using a submersible Particle Image Velocimetry (PIV) system mounted on a telescopic profiling platform with a 10 m profiling range that can align the sample area in any desired direction. The data consist of time series of instantaneous, 2-D velocity distributions in two independent sample areas. The sample areas are spaced to obtain the Reynolds stresses with minimal wave contamination using structure functions. With varying magnifications, the PIV data resolve length scales ranging between 1.2 mm to 1 m, enabling direct calculation of dissipation rate. Preliminary results from the deployments that motivate the present analysis proposal include evidence of: a) Variations of Reynolds stresses and mean current with wave phase. b) Turbulence production lower than the dissipation rate, and variations of stresses with depth in the outer portions of the bottom boundary layer. The stresses seem to scale with the mean current. c) Turbulent energy spectra that increase in similarity to the universal spectrum with increasing Reynolds number, but still indicate anisotropy at all scales, including the dissipation range. e) At moderate, but typical tidal flows, the production is intermittent, occurring during periods of gusts, while the dissipation changes little.

Proper modeling of oceanic circulation is essential for improvements in predictions of climate, weather and human impact on the coastal ocean. Transport of pollutants, nutrients and sediment in coastal waters affect many aspects of human life along the coast including the economy, health, tourism, fisheries and food production. It is essential to obtain the knowledge and understanding that leads to development of improved prediction of oceanic transport, circulation and mixing.

PROPOSAL NO.: CTS-0625571
PRINCIPAL INVESTIGATOR: JOSEPH KATZ
INSTITUTION: JOHNS HOPKINS UNIVERSITY


Intellectual Merit: The investigators propose using a novel digital holographic method to examine flow features near the wall in canonical turbulent boundary layers. This experimental technique is original and promises groundbreaking results in the understanding of turbulent wall bounded flows. The panel was very impressed with the proposal and felt the development of the high resolution digital holographic microscopy (DHM) would be a valuable measurement tool for turbulence. The high spatial resolution of the technique as well has the relatively large measurement region provides the ability to obtain the instantaneous distribution of velocity, wall shear stress as well as near wall flow structures. Tracking the same group of particles in pairs of velocity fields recorded at different times also provides the material acceleration. The PIs have been extremely productive and innovative in the past and the preliminary results using the technique are convincing.

Broader Impacts: Successful completion of this research would have a substantial impact in the field of turbulence by advancing an emerging, high spatial resolution measurement tool for turbulence, as well as providing a valuable data set on canonical boundary layers. This work will be used in an educational plan by involving two graduate students as well as senior high-school students from the Baltimore Polytechnic Institute. Details of the technique will also be made available to the community.

Flow and transport processes in the atmosphere are strongly influenced by orography that generates forces and causes complex flow distortions. At smaller scales, the atmospheric surface layer is also affected substantially by vegetation canopies. Most previous work has focused on effects of hills and vegetated terrain characterized by a single length scale, e.g. a single hill of a particular size, or canopies consisting of plants, often modeled using a prescribed leaf-area density distribution. It is well known, however, that flow obstructions such as mountain ranges and canopies are characterized by a wide range of length scales. Yet, it is not known how to parameterize the effects of such multi-scale objects on the lower atmospheric dynamics. This research addresses this issue with an integrated laboratory experimental and computational program, focusing on atmospheric boundary layer flow over fractal shapes. Fractals provide convenient idealizations of the inherently multi-scale character of mountain range and vegetation geometries, within certain ranges of scales. The experiments consist of laboratory model studies of flow structure and drag forces in an "optically index-matched" facility, where unobstructed, detailed flow and force measurements can be performed within the entire complex domain. Multi-plane particle image velocimetry measurements will provide all components of the stress and velocity gradient tensors. A key motivation for the experimental work is the need to validate and support further development and improvements of a new prediction tool, Renormalized Numerical Simulation (RNS). This technique models forces from unresolved features of the ground topology using drag coefficients determined from interrogation of the large scales that are explicitly resolved on the computational mesh, followed by dynamic rescaling. The RNS will be used to model the flow across fractal trees and mountain ranges, and compare the predicted forces and flow features with the measurements. With the detailed flow data available, causes for discrepancies will be identified and used for improvements.

Research on improving scientific foundations of sub-grid parameterizations of land-atmosphere interactions, the subject of the project, has a broad impact on the infrastructure of atmospheric and climate sciences. Measurements using novel, optically index-matched, methods in the context of atmospheric flow phenomena provide the possibility of a quantum step in the level of detail with which flows can be mapped and understood. Moreover, the development of properly validated RNS applied to flow with fractal boundaries may yield broader impact in areas other than turbulent boundary layers over multi-scale ground topology. Fractals have been used as a descriptive tool in many disciplines, such as biology (branching blood network, pulmonary structures, corals), astrophysics (large-scale structure of the universe, intermittency of interplanetary magnetic fields), and other geosciences aspects (fractal coastlines, clouds). RNS extends the geometric idea of fractals to fluid dynamics. Educational impact of the work will focus on graduate education/training that stresses the interplay between physical experimentation and simulation. As part of the educational outreach effort, interactions with the Baltimore City School system will continue and strengthen. Specifically, senior high-school students from the Baltimore Polytechnic Institute will be involved in yearlong research experiences in our laboratory, as part of their required Research Practicum. Involvement in research on atmospheric flows over fractal boundaries will help motivate talented senior high-school students to consider future careers in this field.

OCE-0648490
Intellectual Merit: Predictions of ocean dynamics, sediment transport, pollutant dispersal and biological processes in the coastal ocean require proper modeling of turbulence in the bottom boundary layer. Obtaining well-characterized data, which is essential for modeling, is a challenge due to the demanding and enormously variable environmental conditions. This project extends our effort to measure the flow structure and turbulence in the bottom boundary layer of the coastal ocean, and study their dependence on circulation, waves, bottom topography, elevation and stratification. Turbulence measurements are performed using a submersible Particle Image Velocimetry (PIV) system with a 10 m profiling range that can align two sample areas independently in any direction, e.g. with mean current, with waves or inclined to each other to measure 3-D flow features. The PIV data consists of two time series of instantaneous, 2-D velocity distributions. With varying magnifications, the data resolve length scales ranging between 1.2 mm to 1 m, enabling direct calculation of dissipation rate or Reynolds stresses from structure functions. Results from previous deployments show: a) Variations of Reynolds stresses and mean current with wave phase. b) Decrease of Reynolds stresses with elevation in outer portions of the boundary layer, consistent with laboratory data. It is found that stresses scale with mean current. c) Decrease of turbulence production dissipation ratio with increasing elevation, from slightly below one at 30 cm elevation to very low values at 1.5 m. The missing energy most likely originates from high production very near bottom, and is transported up by mean flow, waves and turbulence. d) At moderate Reynolds numbers, but typical to tidal flows, events contributing to Reynolds stresses and production occur intermittently during periods of "gusts", while dissipation changes little with time. Meaningful statistics on intermittent events requires a large database. e) Turbulent energy spectra appear more similar to the universal spectrum with increasing Reynolds number, but still indicate anisotropy at all scales, including dissipation range. f) Repeatable variations of sub-grid scale (SGS) stresses and energy flux with wave phase provide direct evidence that wave-induced straining modifies the energy cascading process of turbulence at all scales. Based on these previous observations, objectives of the present study are: a) To identify, measure and subsequently model specific mechanism dominating turbulence production near the benthic-pelagic interface resulting from interactions of currents and waves with a rough bottom. b) To determine causes and contributors to variations of Reynolds stresses with wave phase, including cyclic changes in production due to wave-induced straining at high elevations, interactions of waves with bottom ripples, orientation of waves relative to mean currents and vertical transport of turbulence by waves. Analysis will examine resulting effects on profiles and scaling of mean flow and Reynolds stresses. c) To measure effect of wave-induced straining on SGS energy fluxes and resulting impact on the energy cascading process and turbulent energy spectra at different scales. A large database required for achieving these objectives will be recorded during two deployments near LEO-15. The PIV data will be acquired concurrently with measurements of mean current, direction and amplitude of waves, bottom roughness, temperature spectra, density profiles and buoyancy flux.
Broader impact:
Socio-Economic Issues: Proper modeling of oceanic circulation is essential for predictions of climate, weather and human impact on the coastal ocean. Furthermore, transport of pollutants, nutrients and sediment affect the economy, health, tourism, fisheries and food production along the coast. The data and analysis will contribute to improved predictions of oceanic transport, circulation and mixing. Education of future Scientists: Educational outreach effort with the Baltimore City Schools will continue involving senior high-school students from the Baltimore Polytechnic Institute in a yearlong research experience, as part of their required Research Practicum. On-going participation of undergraduates in field trips and data analysis as a means of motivating them to get involved in oceanography will be continued. The project will support two graduate students that will be trained as oceanographers. Their education includes research, and specially geared courses in oceanography, fluid mechanics, instrumentation, biology and mathematics. A joint degree program available at JHU facilitates interaction with faculty having diverse backgrounds.

Katz
0932941

High Reynolds number turbulent boundary layers continue to pose major scientific and technological challenges due to their inherently complex couplings of dynamics across many length and time scales. Integration of recently introduced techniques enables 3D high-resolution volumetric velocity measurements across a range of scales, from very near the wall to the outer part of the boundary layer. The objective of this study is to experimentally investigate interactions among buffer layer vortices and outer (inertial) layer, larger-scale structures above a smooth wall at moderate to high Reynolds numbers. Data analysis will examine effects of mean flow acceleration and local instantaneous pressure gradients on the characteristics of buffer layer vortices and their effects on turbulence statistics. The study will also address fundamental Large-Eddy Simulation (LES) issues in wall-bounded flows, especially modeling of wall shear stresses in terms of large-scale features that are resolved in LES, and impact of unsteadiness, local pressure gradient, and instantaneous streamwise curvature on the wall stress. Finally, the PIs will develop a systematic method for determining the length-scale required for fully resolving the inner boundary layer flow, both experimentally and numerically. The multi-scale velocity measurements will be performed by simultaneously implementing two state-of-the-art, 3D flow measurement techniques: Relatively "coarse" measurements will be performed using tomographic particle image velocimetry (PIV) at a spatial resolution of 0.5mm. High-resolution velocity measurements near the wall within part of the coarse volume will be performed using digital holographic microscopy (DHM), at a spatial resolution of 20 um. Also, using recently introduced procedures, four-exposure DHM will measure the instantaneous distribution of material acceleration, and provide the local pressure gradients. Experiments will be performed in the optically index-matched facility at JHU that enables unobstructed near-wall measurements, even near rough walls and curved boundaries used for generating mean pressure gradients. In-line DHM, a high-resolution flow measurement technique recently developed in the PIs' laboratory, involves acquisition of in-line holograms of a seeded flow by a digital camera. Numerical reconstruction and particle tracking provide the 3D velocity distribution. The present optical setup and data analysis procedures will be further developed for simultaneous application with tomographic PIV. DHM extends the depth of field of a conventional microscope by 3 orders of magnitude, and may revolutionize microscopy in many other fields that require measurements of 3D dynamic processes as in swimming of bacterial suspensions. The PIs have been active in disseminating holographic microscopy by providing software, training and follow-up assistance to personnel in several academic laboratories, including Rutgers, LSU and VA Tech. The PIs will continue their long-term commitment to and record of success at involving undergraduate students in laboratory and field research, as part of the PIs' effort to motivate them to pursue graduate education. The PIs will also continue engaging high school students from Baltimore Polytechnic in an extensive, yearlong research experience as part of their Research Practicum.

0923391
Katz

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."

The objective of this proposal is to develop a system that can perform multiscale, time resolved, 3D velocity measurements within a finite sample volume of a fluid flow. This instrument integrates and extends the capability of two state-of-the-art, 3D flow measurement techniques. There is a wide range of problems that would greatly benefit from availability of this unique instrument. The near-term objective is to focus on the flow within high Reynolds number turbulent boundary layers over smooth and rough walls, with DHM fully resolving the inner part and tomographic PIV covering the entire boundary layer surrounding the holographic volume. Experiments will be performed in the optically index-matched facility at JHU that enables unobstructed near-wall measurements, even between roughness elements. The time-resolved 3D measurements will provide unprecedented resolution and range of scales spanning four orders of magnitude. Data will be used for addressing several fundamental issues including: (i) Impact of outer layer structures on buffer layer turbulence; (ii) Wall modeling issues related to LES, e.g. relationships between inertial layer structures and wall stresses, and impact of unsteadiness and instantaneous streamwise curvature on wall stress; (iii) Required length scales for fully resolving the flow; and (iv) Relationships among flow structures generated by roughness and turbulence above the roughness sublayer. This system will also be used for investigating turbulent canopy flows.

This project extends efforts by the same team to measure the flow structure and turbulence in the bottom boundary layer (BBL) of the coastal ocean, and study their dependence on circulation, wave field and bottom topography. In-situ measurements have been performed using Particle Image Velocimetry (PIV), which provides time series of 2-D velocity distributions in two independent sample areas, at an unprecedented resolution of 3.5 Kolmogorov scales. Data from other sensors, including an ADV, are also available. Analysis of large datasets obtained in the inner part of the BBL provides profiles of mean velocity, Reynolds shear stress, shear production and dissipation rates, energy spectra, and abundance of eddies. Analysis shows that an inflection point develops in the mean velocity profile, which indicates flow instability, below the mean current log layer, but well above the bottom ripples. Several arguments, including distortion of wave induced velocity, suggest that this inflection develops at the interface between current and thinner wave boundary layer (WBL) below it. Scaling of mean velocity with shear velocity and roughness scales is effective only above the inflection point. Associated instabilities are manifested by a shear production peak at much higher elevations than those in steady rough-wall boundary layers, as well as a rapid increase in the number of small-scale eddies. The latter increases the dissipation rate and modifies the energy spectra. Transition between current and wave boundary layers also involves broad Reynolds stress peaks and shear production exceeding the dissipation rate.

This project focuses on elucidating the flow and turbulence near the inflection point, as well as on turbulence generated by interactions of flow and waves with roughness within the WBL. Relying initially on available data, and subsequently on extensive, but selective additional in situ data that will be obtained, the study will address the following questions: (1) Are the inflection, associated instabilities and high turbulence persistent characteristic features of current-WBL interfaces? (2) How are the inflection and associated Reynolds stresses, production and dissipation rates affected by combinations of mean current, wave-induced motion (amplitude, excursion and direction relative to current) and bottom topography? (3) In laboratory steady boundary layers and in canopy flows, turbulence production peaks very near the interface with roughness elements. The question is whether such an interfacial turbulence production peak exists also within the WBL, in addition to the inflection point peak. (4) What are the characteristic strength, scale and abundance of eddies generated by interactions with roughness? How are they related to the current-wave-bottom scales? Do they affect the scale of eddies populating the inflection area and rest of BBL? How do they affect the turbulence statistics? Do these eddies differ from structures populating steady rough wall boundary layers, and what is the implication of these differences?

In order to provide a meaningful picture on current-waves-turbulence interactions in the coastal BBL, including the above questions, it is essential to obtain and analyze a substantial database at varying Reynolds numbers, ratios of mean current to wave amplitude, orientation of waves relative to mean current, and orientation of both relative to bottom ripples. Consequently, the available database will be extended during two field deployments in several sites along the Atlantic Continental Shelf. These experiments will feature alignment of one PIV plane with mean current and the other one with waves or roughness as well detailed acoustic mapping of the local bottom roughness.
Broader impact: Proper modeling of turbulence in the BBL is essential for predictions of oceanic circulation, climate and weather, as well as transport of pollutants, nutrients and sediment and associated biological processes in coastal waters. The combination of waves, currents and roughness makes modeling of the BBL particularly challenging. Analysis of data obtained by state-of-the-art instruments is an essential step in development of modeling tools.

Education of future Scientists: This project will support two graduate (PhD) students, who will be broadly trained in oceanography, fluid mechanics, optics and instrumentation. Undergraduate students will continue to be involved extensively in field trips, subsequent analysis and publications, as a proven means of motivating them to pursue careers in oceanography. The team will also continue the long-term custom of engaging senior high-school students from a neighboring school (Baltimore Polytechnic) in a yearlong, research practicum project, which is part of their required curriculum.

PI: Katz, Joseph
Proposal Number: 1438203

The proposed research aims to explore how turbulence is generated and sustained close to solid boundaries. It will use findings from very accurate experiments to clarify the way that energy is transferred in turbulent flows between the different regions of the flow. As such, this research would allow the development of correct models for the design of flow systems where solid walls are present, which are in fact the most common cases of turbulent flows in industry and the environment. Educational activities involve graduate and undergraduate students for the development and implementation of the proposed measurement system. There are also activities planned for Baltimore City high-school students to work yearlong in the PI?s laboratory as part of their required Research Practicum.

This work will investigate how the roughness height, wavelength, spatial arrangement and uniformity, affect the generation of vortices, their evolution in time, their interactions with vortices away from the wall, and impact of these interactions on turbulence statistics. A rather comprehensive and non-trivial experimental approach is proposed: A 3D time-resolved tomographic PIV will resolve small-scale turbulence near the wall, while digital holographic microscopy (DHM) will be used to simultaneously observe the large scale structures away from the wall. The combined TPIV-DHM instrument would resolve 3.5 orders of magnitude of length scales.

Bats perform feats of aerial agility that are unique in the animal kingdom, and completely unparalleled by even the very best robotic flying machines. This project aims to discover the fundamental principles that underlie how these animals achieve such superior flight control performance. Bat flight is powered by a ?hand-wing,? i.e. the wing is actually an evolutionary adaptation of the mammalian forelimb. As such, the bat hand-wing shares the same basic anatomy as the human hand and is highly sensitive to physical forces. The bat hand-wing is highly deformable and controllable, and is unlike any artificial wing that has ever been successfully constructed. The bat hand-wing is built from a very thin membrane that stretches across its fingers and is covered with small wind-sensitive hairs that enable the animal to ?feel? the complex flow of air that envelopes its wing. This unique set of flight and sensing adaptations presents a powerful model to investigate the mechanisms of sensing, brain computation, and movement control. The multidisciplinary research team will characterize and uncover the complex coupling relationships between aerodynamics, tactile sensing, and neural processing using a combination of engineering and biological techniques. This project will lead to deeper understanding of biological flight control, and will lend insights into ingredients that could one day be used in developing new robotic aerial vehicles capable of bat-like flight performance.

This project integrates state-of-the-art experimental measurements and computational flow modeling with behavioral and neurophysiological experimentation and dynamical control systems neural modeling. Using a multidisciplinary approach, the team will test the hypothesis that bat wing sensors carry information about complex airflow patterns and forces to the sensory cortex. The team will also elucidate sensorimotor mechanisms that guide wing adjustments to enhance lift and prevent stall. To achieve these goals, the research includes, : 1) Quantifying the mechanical stimulus inputs to receptors on the bat hand-wing using stereo-particle-image velocimetry, digital image correlation and computational fluid dynamic modeling; 2) Encoding mechanosensory signals from the wings via multichannel neural recordings from bat primary somatosensory cortex; 3) Closed-loop modeling and real-time control based on decoded output of neural signals. This research will yield a deeper understanding of sensorimotor feedback in biological systems while also contributing novel computational and experimental tools in the arena of sensorimotor control, biophysics, and mechanics, with wide applications to many arenas of neuroscience. The project will leverage the JHU?s Women in Science and Engineering (WISE) program and Baltimore Polytechnic?s Ingenuity Project to engage high school students from diverse backgrounds.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.