A new version of the ENERGY-10 computer program simulates the performance of photovoltaic systems, in addition to presenting a wide range of opportunities to improve energy efficiency in buildings. This paper describes two test cases in which the beta release of ENERGY-10 version 1.4 was used to evaluate energy efficiency and building-integrated photovoltaics (BIPV) for two Federal building projects: an office and laboratory building at the Smithsonian Astrophysical Laboratory in Hilo, Hawaii, and housing for visiting scientists at the Smithsonian Environmental Research Center in Edgewater, Maryland. The paper describes the capabilities of the software, the method in which ENERGY-10 was used to assist in the design, and the results. ENERGY-10 appears to be an effective tool for evaluating BIPV options early in the building design process. By simulating both the building electrical load and simultaneous PV performance for each hour of the year, the ENERGY-10 program facilitates a highly accurate, integrated analysis.

Angle-resolved XPS (ARXPS) was performed on thin films of 2-methyl-4-nitroanaline (MNA) vapor deposited onto a Si(001) substrate. The relative concentrations of the different components observed in the MNA film at takeoff angles of 30 and 90 degrees was determined. This allows an estimation of the layer composition and thickness as well as depth of all layers within a region of several electron escape depths from the surface [1]. The results obtained are compared to layer thicknesses from ellipsometric measurements and atomic force microscopy (AFM).

Electron lens aberration is the major barrier limiting the resolution of electron microscopy. Here we describe a novel form of electron microscopy to overcome electron lens aberration. By combining coherent electron diffraction with the oversampling phasing method, we show that the 3D structure of a 2 x 2 x 2 unit cell nano-crystal (framework of LTA [Al12Si12O48]8) can be ab initio determined at the resolution of 1 Angstrom from a series of simulated noisy diffraction pattern projections with rotation angles ranging from -70 degrees to +70 degrees in 5 degrees increments along a single rotation axis. This form of microscopy (which we call 3D electron diffraction microscopy) does not require any reference waves, and can image the 3D structure of nanocrystals, as well as non-crystalline biological and materials science samples, with the resolution limited only by the quality of sample diffraction.

Recent lattice QCD calculations of the baryon spectrum are outlined.

The dynamics of a longitudinally cold, charged-particle beam can be simulated by dividing the beam into slices and calculating the motion of the slice boundaries due to the longitudinal electric field generated by the beam. On each time step, the beam charge is deposited onto an (r, z) grid, and an existing (r, z) electrostatic field solver is used to find the longitudinal electric field. Transversely, the beam envelope equation is used for each slice boundary separately. In contrast to the g-factor model, it can be shown analytically that the repulsive electric field of a slice compressed to zero length is bounded. Consequently, this model allows slices to overtake their neighbors, effectively incorporating mixing. The model then effectively describes a cold fluid in longitudinal z, v{sub z} phase space. Longitudinal beam compression calculations based on this cold phase fluid model showed that slice overtaking reflects local mixing, while the global phase space structure is preserved.

A new definition is proposed for the effective number of bits of an ADC. This definition removes the variation in the calculated effective bits when the amplitude and offset of the sinewave test signal is slightly varied. This variation is most pronounced when test signals with amplitudes of a small number of code bin widths are applied to very low noise ADC's. The effectiveness of the proposed definition is compared with that of other proposed definitions over a range of signal amplitudes and noise levels.

High performance polymers are of interest for high temperature gas separations, especially for the sequestration of carbon dioxide. A new family of high performance imide polymers has been identified as a successful membrane capture material. VTEC polyimides possess desired thermal properties (up to 500 °C) along with being robust and flexible even after multiple thermal cycles (up to 400 °C). Polyimides (PI) are excellent materials for high selectivity for smaller kinetic diameter gases such as H2 and CO2; however, they have low fluxes. We blended small amounts of different polymers with VTEC polyimide, which changes the fluxes. Another critical problem when working with glassy polymers is their moisture content. It has been found that water entrapped within the polymer matrix (left over from the solvent, or physisorbed) can also cause the polymer to change dramatically. Additionally presence of molecular water in the polymer’s void volume has been validated through Positron Annihilation Lifetime (PAL) spectroscopy. In this presentation, polymer characterization and gas-separation testing results will be discussed.

Electron field emission (FE) from broad-area metal surfaces is known to occur at much lower electric field than predicted by Fowler-Nordheim law. Although micron or submicron particles are often observed at such enhanced field emission (EFE) sites, the strength and number of emitting sites and the causes of EFE strongly depend on surface preparation and handling, and the physical mechanism of EFE remains unknown. To systematically investigate the sources of this emission, a DC scanning field emission microscope (SFEM) has been built as an extension to an existing commercial scanning electron microscope (SEM) equipped with an energy-dispersive spectrometer (EDX/EDS) for emitter characterization. In the SFEM chamber of ultra high vacuum ({approx}10-9 Torr), a sample is moved laterally in a raster pattern (2.5 mm step resolution) under a high voltage anode micro-tip for field emission detection and localization. The sample is then transferred under vacuum by a hermetic retractable linear transporter to the SEM chamber for individual emitter site characterization. Artificial marks on the sample surface serve as references to convert x, y coordinates of emitters in the SFEM chamber to corresponding positions in the SEM chamber with a common accuracy of {+-}100-200 mm in x and y. Samples designed to …

The DeltaQ test has been developed in order to provide better estimates of forced air system air leakage for use in energy efficiency calculations and for compliance testing of duct systems. The DeltaQ test combines a model of the house and duct system with the results of house pressurization tests with the air handler on and off to determine the duct leakage air flows to outside conditioned space at operating conditions. The key advantage of the DeltaQ test over other methods is that it determines the air leakage flows directly, rather than requiring interpretation of indirect measurements. The results from over 200 field and laboratory tests are presented. The laboratory tests have shown that the DeltaQ repeatability uncertainties are typically 1% or less of system fan flow and that the accuracy of the test is between 1.3% and 2.5% of fan flow (or 13 cfm to 25 cfm (6 to 12 l/s) for this system).

Work in recent years has produced improvements in determining the solar resource by better characterizing the responsivity of pyranometers. The calibration process can characterize a common responsivity dependency on the solar zenith angle, which can then be used to compensate for sensor variations during instrument deployment. However, daily compensation throughout the range of zenith angles might not be necessary for applications requiring only annual irradiance. This paper describes a method of identifying a measurement bias due to latitude of deployment and optimizing an instrument's clear-sky responsivity for annual solar radiation measurements based on the relationship between solar zenith angles and the latitude.

Residential air conditioning is responsible for a substantial amount of peak electrical demand and energy consumption throughout most of the United States. Coil fouling, the deposition of indoor dusts and other particulate matter on evaporator heat exchangers, increases system pressure drop and, correspondingly, decreases system air flow and air conditioner performance. In this paper, we apply experimental and simulation results describing particle deposition on evaporator coils as well as research about indoor particle and dust concentrations to determine coil fouling rates. The results suggest that typical coils foul enough to double evaporator pressure drop in about 7.5 years, much sooner than the expected 15-30 year life time for an evaporator coil. The most important parameters in determining coil fouling times are the efficiency of the filter and indoor particle concentrations, although filter bypass and duct and coil design are important as well. The reduced air flows that result from coil fouling cause typical efficiency and capacity degradations of less than 5%, however they can be much greater for marginal systems or extreme conditions. These energy issues, as well as possible indoor air quality issues resulting from fouling by biological aerosols, suggest that regular coil cleaning to ameliorate low flow and …

Recent electroproduction results in the domain of s-channel nucleon resonance excitation are presented, and preliminary data in the search for missing states will be discussed. I also address a new avenue to pursue N* physics using exclusive deeply virtual Compton scattering, recently measured for the first time at JLab and DESY.

The mission of the EMSP is to develop and fund targeted, long-term research programs that will result in transformational or breakthrough approaches for solving DOE’s environmental problems. The purpose of this research is to provide the basic science knowledge that will lead to reduced remediation cost, schedule, technical uncertainty, and risk.

We present first results of calculations of masses of positive and negative parity excited baryons in lattice QCD using an O(a{sup 2}) improved gluon action and a fat-link clover fermion action in which only the irrelevant operators are constructed with fat links. The results are in agreement with earlier calculations of N* resonances using improved actions and exhibit a clear mass splitting between the nucleon and its chiral partner. The results also indicate a splitting between the lowest J{sup P}=(1/2){sup -} states for the two standard nucleon interpolating fields. The study of different Lambda interpolating fields suggests a similar splitting between the lowest two Lambda{sup 1/2{sup -}} octet states. However, the empirical mass suppression of the Lambda*(1405) is not evident in these quenched QCD simulations, suggesting an important role for the meson cloud of the Lambda*(1405) or a need for more exotic interpolating fields.

A Compton polarimeter has been installed in Hall A at Jefferson Laboratory. This letter reports on the first electron beam polarization measurements performed during the HAPPEX experiment at an electron energy of 3.3 GeV and an average current of 40 muA. The heart of this device is a Fabry-Perot cavity which increased the luminosity for Compton scattering in the interaction region so much that a 1.4% statistical accuracy could be obtained within one hour, with a 3.3% total error.

Article reporting findings from the Environmental Protection Agency (EPA)'s Environmental Monitoring and Assessment Program (EMAP) conducted on a sample of lakes in the Northeastern United States from 1991 to 1996.

Several surface adsorptions related field emission behaviors were investigated for W, Pt/Ir metal tips and multi-wall carbon nanotubes (MWNT). With the help of Fowler-Nordheim theory, we show clearly that there exists a stabilization process of the surface effective work function for W, Pt/Ir and MWNT emitters during emitting. Joule heating from electron emission may desorb the adsorbates on the emission sites of the metal emitter. We observed large emission current variation for MWNT emitters when they were tested after exposure to atmosphere. We suggest that there exist two different surface reaction modes in initial emission period, which are H{sub 2}O and H{sub 2} dominated processes respectively. An emission-adsorption equilibrium state may form stronger surface-adsorbate bonds. Nitrogen gas is a good protecting environment to maintain emission stability during the vacuum-atmosphere cycle. Operation of MWNT emitters under hydrogen atmosphere may improve the emission, which could be related to the modification of the surface work function. We suggest that surface adsorbate participated reaction is the dominated factor for the emission loss.

We present a calculation of the lowest-lying baryon masses in the quenched approximation to QCD. The calculations are performed using a non-perturbatively improved clover fermion action, and a splitting found between the masses of the nucleon and its parity partner. An analysis of the mass of the first radial excitation of the nucleon finds a value considerably larger than that of the parity partner of the nucleon, and thus little evidence for the Roper resonance as a simple three-quark state.

Solid state lighting in the form of Light Emitting Diodes (LEDs) is bringing new sources with different operating characteristics to the market. With the control in dimension, optics, intensity and color, these sources have the potential to transform the way we use light. This paper will review the recent improvements in performance that have been achieved by these devices, focusing on those product attributes identified as being critical to end users. The paper will conclude with a consideration of applications capitalizing on the LEDs' unique operating and physical properties.

Researchers installed radon mitigation systems in 12 houses in Spokane, Washington and Coeur d'Alene, Idaho during the heating season 1985--1986 and continued to monitor indoor radon quarterly and annually for ten years. The mitigation systems included active sub-slab ventilation, basement over-pressurization, and crawlspace isolation and ventilation. The occupants reported various operational problems with these early mitigation systems. The long-term radon measurements were essential to track the effectiveness of the mitigation systems over time. All 12 homes were visited during the second year of the study, while a second set 5 homes was visited during the fifth year to determine the cause(s) of increased radon in the homes. During these visits, the mitigation systems were inspected and measurements of system performance were made. Maintenance and modifications were performed to improve system performance in these homes.

We report N* masses in the spin 3/2 sector from a highly-improved anisotropic action. States with both positive and negative parity are isolated via a parity projection method. The extent to which spin projection is needed is examined. The gross features of the splittings from the nucleon ground state show a trend consistent with experimental results at the quark masses explored.

The ratio of the electric and magnetic form factors of the proton, G{sub E{sub p}}/G{sub M{sub p}}, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic {rvec e}p {yields} e{rvec p} reaction. The new data presented in this article span the range 3.5 < Q{sup 2} < 5.6 GeV{sup 2} and are well described by a linear Q{sup 2} fit. Also, the ratio QF{sub 2p}/F{sub 1p} reaches a constant value above Q{sup 2}=2 GeV{sup 2}.

SASE saturation was recently achieved at the Advanced Photon Source's SASE FEL in the low-energy undulator test line (LEUTL) at 530 nm and 385 nm. The electron beam microbunching becomes more and more prominent until saturation is achieved. This bunching causes nonlinear harmonic emission that extends the usefulness of a SASE system in achieving shorter FEL wavelengths for the same electron beam energy. They have investigated the intensity of the fundamental and second-harmonic undulator radiation as a function of distance along the undulator line and present the experimental results and compare them to numerical simulations. In addition, they have measured the single-shot second harmonic spectra as well as the simultaneous fundamental and second harmonic spectra and present the experimental results.

None