A letter report issued by the Government Accountability Office with an abstract that begins "The Department of Energy (DOE) pays its contractors billions of dollars each year to implement its major projects--those costing more than $400 million each. Many major projects have experienced substantial cost and schedule overruns, largely because of contract management problems. GAO was asked to assess, for major departmental projects, (1) DOE's use of performance incentives to effectively control costs and maintain schedules, (2) the reliability of the data DOE uses to monitor and assess contractor performance, and (3) the reliability of the Project Assessment and Reporting System (PARS) data that senior managers use for project oversight."

A letter report issued by the Government Accountability Office with an abstract that begins "If completed, the Free Trade Area of the Americas (FTAA) agreement would encompass an area of 800 million people and about $13 trillion in production of goods and services, making it the most significant regional trade initiative presently being pursued by the United States. The 34 democratic nations of the Western Hemisphere formally launched negotiations towards a FTAA in 1998, and set a January 2005 deadline for concluding a FTAA agreement. GAO was asked to analyze (1) progress made in FTAA negotiations since GAO's last (April 2003) report (2) factors that have been influencing the FTAA's progress; and (3) future prospects for the FTAA. USTR disagreed with our report, stating it was a poorly framed portrayal of progress and problems in the negotiations, overemphasized the role of the United States and Brazil in the current impasse, and did not give sufficient weight to U.S. efforts to make progress. GAO made several changes in response, but disagreed with USTR's assessment. The Departments of State, Commerce, and Agriculture provided technical comments, which we incorporated."

The ability to fabricate membranes with arrays of apertures only a few nanometers in diameter are important to many fields of research, including ion beam lithography, DNA sequencing, single ion implantations, and single molecule studies. Because even the state-of-the-art lithography tools are limited in their ability to produce nanoscale features, alternative methods of fabricating single pores of nanometer scale have been developed, using ion-beam sculpting and focused-ion-beam assisted deposition. However, these methods cannot simultaneously produce multiple holes of nanometer dimension. Here we report a means of forming arrays of nanopores simultaneously on a thin, solid-state membrane using plasma-based thin-film deposition. By depositing layers of metallic thin films, the aperture sizes of pores in a pre-fabricated membrane can be reduced from a couple of micrometers down to tens of nanometers and even smaller. The technique offers a way to reduce the sizes of aperture of any shape in a variety of substrate materials, both conducting and insulating. Such arrays of nanopores can serve as membrane channels for DNA sequencing, as masks in ion-beam imprinters, for the fabrication of quantum dots, and in other applications.

Free weekly newspaper that includes business and classified advertising.

Free weekly newspaper that includes business and classified advertising.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Whether an appraisal review board may schedule a hearing on a property tax protest and notify the property owner of the hearing time before the property owner has filed a written notice of protest.

Free weekly newspaper that includes business and classified advertising.

In November and December of 2004, the Tank Farm submitted annual samples from 2F, 2H and 3H Evaporator Overhead streams for characterization to verify compliance with the new Effluent Treatment Facility (ETF) Waste Acceptance Criteria (WAC) and to look for organic species. With the exception of slightly high ammonia in the 2F evaporator overheads and high radiation control guide number for the 3H and 2F evaporator overhead samples, all the overheads samples were found to be in compliance with the Effluent Treatment Facility WAC. The ammonium concentration in the 2F-evaporator overhead, at 33 mg/L, was above the ETF waste water collection tank (WWCT) limits of 28 mg/L. The RCG Number for the 3H and 2F evaporator samples at, respectively, 1.38E-02 and 8.24E-03 were higher than the WWCT limit of 7.69E-03. The analytical detection limits for americium-241 and radium-226 in the evaporator samples were not consistently met because of low WWCT detection limits and insufficient evaporator samples.

This paper presents a combinatorial study on the problem ofconstructing a sparse basis forthe null-space of a sparse, underdetermined, full rank matrix, A. Such a null-space is suitable forsolving solving many saddle point problems. Our approach is to form acolumn space basis of A that has a sparse inverse, by selecting suitablecolumns of A. This basis is then used to form a sparse null-space basisin fundamental form. We investigate three different algorithms forcomputing the column space basis: Two greedy approaches that rely onmatching, and a third employing a divide and conquer strategy implementedwith hypergraph partitioning followed by the greedy approach. We alsodiscuss the complexity of selecting a column basis when it is known thata block diagonal basis exists with a small given block size.

Weekly newspaper from Clifton, Texas that includes local, state, and national news along with advertising.

Aerosol optical depth variation over short-term time intervals is determined from broadband observations of stars with a whole sky imager. The main difficulty in such measurements consists of accurately separating the star flux value from the non-stellar diffuse skylight. Using correction method to overcome this difficulty, the monochromatic extinction at the ground due to aerosols is extracted from heterochromatic measurements. A form of closure is achieved by comparison with simultaneous or temporally close measurements with other instruments, and the total error of the method, as a combination of random error of measurements and systematic error of calibration and model, is assessed as being between 2.6 and 3% rms.

The effect of aerosols on the clouds, or the so-called aerosol indirect effect (AIE), is highly uncertain (Penner et al. 2001). The estimation of the AIE can vary from 0.0 to -4.8 W/m2 in Global Climate Models (GCM). Therefore, it is very important to investigate these interactions and cloud-related physical processes further. The Aerosol Intensive Operation Period (AIOP) at the Southern Great Plains (SGP) site in May 2003 dedicated some effort towards the measurement of the Cloud Condensation Nucleus concentration (CCN) as a function of super-saturation and in relating CCN concentration to aerosol composition and size distribution. Furthermore, airborn measurement for the cloud droplet concentration was also available. Therefore this AIOP provides a good opportunity to examine the AIE. In this study, we use a Cloud Resolving Model (CRM), i.e., Active Tracer High-resolution Atmospheric Model (ATHAM), to discuss the effect of aerosol loadings on cloud droplet effective radius (Re) and concentration. The case we examine is a stratiform cloud that occurred on May 17, 2003.

The problem of the choice of the aerosol optical constants and, in particular, imaginary part of the refractive index of particles in visible and infrared (IR) wavelength ranges is very important for calculation of the global albedo of the atmosphere in climatic models. The available models of the aerosol optical constants obtained for the prescribed chemical composition of particles (see, for example, Ivlev et al. 1973; Ivlev 1982; Volz 1972), often are far from real aerosol. It is shown in (Krekov et al. 1982) that model estimates of the optical characteristics of the atmosphere depending on the correctness of real and imaginary parts of the aerosol complex refractive index can differ by some hundreds percent. It is known that the aerosol extinction coefficient {alpha}({lambda}) obtained from measurements on a long horizontal path can be represented as {alpha}({lambda})={sigma}({lambda})+{beta}({lambda}), where {sigma} is the directed light scattering coefficient, and {beta} is the aerosol absorption coefficient. The coefficient {sigma}({lambda}) is measured by means of a nephelometer. Seemingly, if measure the values {alpha}({lambda}) and {sigma}({lambda}), it is easy to determine the value {beta}({lambda}). However, in practice it is almost impossible for a number of reasons. Firstly, the real values {alpha}({lambda}) and {sigma}({lambda}) are very close …

Water vapor is well known to be a critical component in many aspects of atmospheric research, such as radiative transfer and cloud and aerosol processes. This requires both improved measurements of the columnar water vapor and its profiles in the atmosphere in a wide range of conditions, and adjustment of water vapor parameterizations in radiation codes including the perfection of spectroscopic parameters. In this paper we will present the results of comparison of our calculations and downward solar fluxes measured with Rotating Shadowband Spectroradiometer under conditions of horizontally homogeneous clouds. We also will discuss the sensitivity of atmospheric radiation characteristics to variations of water vapor in the band 940 nm: these results may be useful for development of new methods of retrieval of the total column water vapor content (WVC) in the atmosphere from data of radiation observations.

There are currently twenty-four Multi-Filter Rotating Shadowband Radiometers (MFRSR) operating within Atmospheric Radiation Measurement (ARM). Eighteen are located within the Southern Great Plains (SGP) region, there is one at each of the North Slope of Alaska (NSA) and Tropical Western Pacific (TWP) sites, and one is part of the instrumentation of the ARM Mobile Facility. At this time there are four sites, all extended facilities within the SGP, that are equipped for a MFRSR but do not have one due to instrument failure and a lack of spare instruments. In addition to the MFRSRs, there are three other MFRSR derived instruments that ARM operates. They are the Multi-Filter Radiometer (MFR), the Normal Incidence Multi-Filter Radiometer (NIMFR) and the Narrow Field of View (NFOV) radiometer. All are essentially just the head of a MFRSR used in innovative ways. The MFR is mounted on a tower and pointed at the surface. At the SGP Central Facility there is one at ten meters and one at twenty-five meters. The NSA has a MFR at each station, both at the ten meter level. ARM operates three NIMFRs; one is at the SGP Central Facility and one at each of the NSA stations. There are …

Variations of dendrochronologic parameters, especially annual ring density, significantly reflect the physiological tree response to systematic variations of solar UV-B radiation, taking place on monthly and longer timescales during growing season. Such variations of UV-B radiation are totally governed by variations of total ozone (TO). Thus, in any dendrochronologic signal, especially for coniferous trees, there is also a recorded response to TO variations, characterizing variations of UV-B radiation. Because a monitoring of global TO distribution is regularly performed since 1979 using TOMS satellite instrumentation, there appears a possibility to reconstruct TO behavior in the past practically at any point of dendrochronologic monitoring network. The reconstruction is performed by the method of linear regression, based on significant correlation of annual ring density of coniferous trees and TO for coordinates of denrochronologic signal. The present report considers the Subarctic latitudes, which are characterized by considerable TO variations in the second half of twentieth century.

Our overall goal is identical to that of the Atmospheric Radiation Measurement (ARM) Program: the development of new and improved parameterizations of cloud-radiation effects and related processes, using ARM data at all three ARM sites, and the implementation and testing of these parameterizations in global and regional models. To test recently developed prognostic parameterizations based on detailed cloud microphysics, we have first compared single-column model (SCM) output with ARM observations at the Southern Great Plains (SGP), North Slope of Alaska (NSA) and Topical Western Pacific (TWP) sites. We focus on the predicted cloud amounts and on a suite of radiative quantities strongly dependent on clouds, such as downwelling surface shortwave radiation. Our results demonstrate the superiority of parameterizations based on comprehensive treatments of cloud microphysics and cloud-radiative interactions. At the SGP and NSA sites, the SCM results simulate the ARM measurements well and are demonstrably more realistic than typical parameterizations found in conventional operational forecasting models. At the TWP site, the model performance depends strongly on details of the scheme, and the results of our diagnostic tests suggest ways to develop improved parameterizations better suited to simulating cloud-radiation interactions in the tropics generally. These advances have made it possible to …

A theoretical study of problems relevant to the hadron physics program at Jefferson Laboratory and at other laboratories around the world.

One of the Atmospheric Radiation Measurement (ARM) Program important goals is to develop and test radiation and cloud parameterizations of climate models using single column modeling (SCMs) (Randall et al. 1996). As forcing terms, SCMs need advection tendency of cloud condensates besides the tendencies of temperature, moisture and momentum. To compute the tendency terms of cloud condensates, 3D distribution of cloud condensates over a scale much larger than the climate model's grid scale is needed. Since they can cover a large area within a short time period, satellite measurements are useful utilities to provide advection tendency of cloud condensates for SCMs. However, so far, most satellite retrieval algorithms only retrieve vertically integrated quantities, for example, in the case of cloud ice, ice water path (IWP). To fulfill the requirement of 3D ice water content field for computing ice water advection, in this study, we develop an ice water content profile retrieval algorithm by combining the vertical distribution characteristics obtained from long-term surface radar observations and satellite high-frequency microwave observations that cover a large area. The algorithm is based on the Bayesian theorem using a priori database derived from analyzing cloud radar observations at the Southern Great Plains (SGP) site. The …

The methods of sun-photometry of the atmosphere based, for example, on interpretation of the angular distribution of radiation in the solar almucantar are widely used for retrieval of the aerosol optical characteristics. Preliminary analysis has shown that the near-horizon region also can be interesting for solving some applied problems. As is known, investigations of the structure of the daytime cloudless sky brightness at observation from the ground were carried out principally at zenith angles less than 80{sup o} in visible wavelength range. For further development of the methods it is necessary to obtain more complete data on the distribution of the cloudless sky brightness at great zenith angles of observation and wider wavelength range. The regularities of formation of the sky brightness field in the near-horizon region and just above the horizon line are considered in this paper.

Improving climate model predictions over Earth's polar regions requires a comprehensive knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface, making it difficult to detect clouds and retrieve their phase from space. Snow and ice cover, temperature inversions, and the predominance of mixed-phase clouds make it even more difficult to determine cloud phase. Also, since determining cloud phase is the first step toward analyzing cloud optical depth, particle size, and water content, it is vital that the phase be correct in order to obtain accurate microphysical and bulk properties. Changes in these cloud properties will, in turn, affect the Arctic climate since clouds are expected to play a critical role in the sea ice albedo feedback. In this paper, the IR trispectral technique (IRTST) is used as a starting point for a WV and 11-{micro}m brightness temperature (T11) parameterization (WVT11P) of cloud phase using MODIS data. In addition to its ability to detect mixed-phase clouds, the WVT11P also has the capability to identify thin cirrus clouds overlying mixed or liquid phase clouds (multiphase ice). Results from the Atmospheric Radiation Measurement (ARM) MODIS phase model (AMPHM) are compared to the surface-based …

The satellite imagery in Figure 1 provides dramatic examples of how aerosol influences the cloud field. Aerosol from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top image), or can enhance the reflectance/albedo in already cloudy regions. This image is a demonstration of the first indirect effect, in which changes in aerosol modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), aerosol can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom image) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low aerosol concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-aerosol system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-aerosol problem. 1. Drizzling and nondrizzling simulations …

Internal variability of stratiform clouds is manifested on grid scales ranging from cloud resolving models to general circulation models, and its accurate formulation is one of the most important tasks in improvement of model predictions. Understanding cloud variability on different scales will help to develop and improve subgrid-scale cloud parameterizations. Information about variability is also crucial when dealing with retrieval of microphysical information from observations of volume averaged reflectivity parameters, since neglecting variability can lead to substantial biases in estimation of retrieved microphysical variables. The Atmospheric Radiation Measurement Program (ARM) operates millimeter wave cloud radar (MMCR) at the ARM Climate Research Facility over the Southern Great Plains (ACRF SGP) that provides a unique opportunity to obtain continuous observations in order to address issues of cloud variability. These data contain information on spatial and/or temporal short- and long-range correlations in cloudiness, enabling scale-by-scale (scaling) analyses over a range of hundreds of meters to hundreds of kilometers. The objective of this study is to conduct an analysis based on radar reflectivity observations of clouds over the ACRF SGP site with special emphasis on boundary layer clouds, and the effect of drizzle.

Quantification of the aerosol direct effect and climate sensitivity requires accurate estimates of optical properties as inputs to a radiative transfer model. Long-term measurements of aerosol properties at the Southern Great Plains (SGP) site can be used as an improvement over a best guess or global average for optical properties (e.g., asymmetry factor of 0.7) used in Atmospheric Radiation Measurement (ARM) products such as the Broadband Heating Rate Profile VAP. To make this information readily available to the ARM community and others, an add-on module for a commonly used radiative transfer model, SBDART (Ricchiazzi et al. 1998), is being developed. A look up table and algorithm will provide aerosol related model inputs including aerosol optical and atmospheric state properties at high temporal resolution. These inputs can be used in conjunction with any mode of operation and with any other information, for example, cloud properties, in SBDART or any other radiative transfer model. Aerosol properties measured at three visible wavelengths are extrapolated so that flux calculations can be made in any desired wavelength across the shortwave spectrum. Several sources of uncertainty contribute to degraded accuracy of the aerosol property estimation. The effect of these uncertainties is shown through error analysis and …