Analysis of field measurements of carbon dioxide and water vapor fluxes

Analysis of the field measurements of carbon dioxide and water vapor fluxes is discussed. These data were examined in conjunction with reflectance obtained from helicopter mounted Modular Multiband Radiometer. These measurements are representative of the canopy scale (10 to 100 m)(exp 2) and provide a good basis for investigating the hypotheses/relationship potentially useful in remote sensing applications. All the micrometeorological data collected during FIFE-89 were processed and fluxes of CO2, water vapor, and sensible heat were calculated. Soil CO2 fluxes were also estimated. Employing these soil CO2 flux values, in conjunction with micrometeorological measurements, canopy photosynthesis is being estimated. A biochemical model of leaf photosynthesis was adapted to the prairie vegetation. The modeled leaf photosynthesis rates were scaled up to the canopy level. This model and a multiplicative stomatal conductance model are also used to calculate canopy conductance

Analysis of soil and species composition

Measurements were made during May to October, 1987 and June to August, 1989 over a tallgrass prairie near Manhattan, Kansas. Soil at the experimental site is predominantly Dwight silty clay loam. The prairie was burned on 16 April 1987 and on 28 April 1989 to improve the mix of grasses and forbs. The experimental area was not grazed during 1986 - 1989. A summary of results are given for soil moisture and plant growth; momentum flux and canopy aerodynamic characteristics; evapotranspiration, components of energy balance and canopy conductance; modeling canopy stomatal conductance; canopy photosynthesis, photosynthetic efficiency and water use efficiency; modeling canopy photosynthesis; the carbon dioxide budget in a temperate grassland ecosystem; and photosynthesis and stomatal conductance related to reflectance on the canopy scale

Stable configurations of hybrid stars with colour-flavour-locked core

We construct static and mass-shedding limit sequences of hybrid stars, composed of colour flavour locked (CFL) quark matter core, for a set of equations of state (EOSs). The EOS for the hadronic matter is obtained using appropriately calibrated extended field theoretical based relativistic mean-field model. The MIT bag model is employed to compute the EOSs of the CFL quark matter for different values of the CFL gap parameter in the range of $50 - 150\text{MeV}$ with the deconfinement phase transition density ranging from $4\rho_0 - 6\rho_0$ ($\rho_0 = 0.16\text{fm}^{-3}$). We find, depending on the values of the CFL gap parameter and the deconfinement phase transition density, the sequences of stable configurations of hybrid stars either form third families of the compact stars or bifurcate from the hadronic sequence. The hybrid stars have masses $1.0 - 2.1 M_\odot$ with radii $9 - 13.5$ km. The maximum values of mass shedding limit frequency for such hybrid stars are $1 -2$ kHz. For the smaller values of the CFL gap parameter and the deconfinement phase transition density, mass-radius relationships are in harmony with those deduced by applying improved hydrogen atmosphere model to fit the high quality spectra from compact star X7 in the globular cluster 47 Tucanae. We observed for some cases that the third family of compact stars exist in the static sequence, but, disappear from the mass-shedding limit sequence. Our investigation suggests that the third family of compact stars in the mass-shedding limit sequence is more likely to appear, provided they have maximum mass in the static limit higher than their second family counterpart composed of pure hadronic matter.Comment: 27 pages including 10 figures. Accepted in Phys. Rev.

A Method for Dynamic Characterization and Response Prediction Using Ground Vibration Test(GVT)Data for Unknown Structures.

The Objective Of This Proposed Work Is To Develop A Reliable Method For Dynamic Characterization And Prediction Of Dynamic Response Of Structures Of Known/Unknown Configurations, By Processing The Free Vibration Data Generated Experimentally From The Ground Vibration Tests (GVT)Of The Prototype Vehicles. The Methodology Would Make Use Of The Measured Dynamic Data In Terms Of Mode Shapes, Natural Frequencies, Modal Damping, Point Impedances Etc.And Generate Modal (Scaled) Stiffness And Inertia Information That Will Be Used For Prediction Of Response Characteristics Of The Prototype Structure . With These Objectives, The Present Work Develops The Mathematical Formulation Of The Method, And Demonstrates Its Reliability By Performing The Experiment On A Simple Cantilever Beam To Determine Its Dynamic Characteristics. Results On Scaled Modal Stiffness And Inertia, Generated Through The Method Using Experimental (GVT) Data Show Excellent Agreement With Those Generated By FE And Analytical Models .It Must Be Noted That A Valid Benchmarking Is Performed With The Condition That The Experimental Procedure Is 'Blind' To The Actual Stiffness And Inertia Distributions As Used In FEM Or Analytical Models . Agreement Of The Predicted Response Of The Structure With That From Direct Experiment And Those From The FE And Analytical Models Indicates That This Method Will Be A Promising Tool To Predict The Dynamic And Aeroelastic Characteristics Of Any Prototype Vehicle In The Future. Once The Reliability Of The Method Is Established,It Can Be Extended To Determine The Dynamic And Aeroelastic Characteristics Of All Aircraft For Which Dynamic Characteristics Are Available From A Ground -; Vibration Test (GVT)

Correlations in the properties of static and rapidly rotating compact stars

Correlations in the properties of the static compact stars (CSs) and the ones rotating with the highest observed frequency of 1122Hz are studied using a large set of equations of state (EOSs). These EOSs span various approaches and their chemical composition vary from the nucleons to hyperons and quarks in $\beta$-equilibrium. It is found that the properties of static CS, like, the maximum gravitational mass $M_{\rm max}^{\rm stat}$ and radius $R_{1.4}^{\rm stat}$ corresponding to t he canonical mass and supramassive or non-supramassive nature of the CS rotating at 1122 Hz are strongly correlated. In particular, only those EOSs yield the CS rotating at 1122Hz to be non-supramassive for which \left (\frac{M_{\rm max}^{\rm stat}}{M_\odot}\right )^{1/2} \left (\frac{10{\rm km}}{R_{1.4}^{\rm stat}})^{3/2} is greater than unity. Suitable parametric form which can be used to split the $M_{\rm max}^{\rm stat}$ $-$ $R_{1.4}^{\rm stat}$ plane into the regions of different supramassive nature of the CS rotating at 1122Hz is presented. Currently measured maximum gravitational mass 1.76$M_\odot$ of PSR J0437-4715 suggests that the CS rotating at 1122Hz can be non-supramassive provided $R_{1.4}^{\rm stat} \leqslant 12.4$ km.Comment: 13 pages, 4 figures, Appearing in Phys. Rev.

The Connection Between Pulsation, Mass Loss and Circumstellar Shells in Classical Cepheids

Recent observations of Cepheids using infrared interferometry and Spitzer photometry have detected the presence of circumstellar envelopes (CSE) of dust and it has been hypothesized that the CSE's are due to dust forming in a Cepheid wind. Here we use a modified Castor, Abbott & Klein formalism to produce a Cepheid wind, and this is used to estimate the contribution of mass loss to the Cepheid mass discrepancy Furthermore, we test the OGLE-III Classical Cepheids using the IR fluxes from the SAGE survey to determine if Large Magellanic Cloud Cepheids have CSE's. It is found that IR excess is a common phenomenon for LMC Cepheids and that the resulting mass-loss rates can explain at least a fraction of the Cepheid mass discrepancy, depending on the assumed dust-to-gas ratio in the wind.Comment: 5 pages, 3 figures, proceeding for "Stellar Pulsation: Challenges for Theory and Observation", Santa Fe 200