@conference {60094, title = {Potential energy savings with exterior shades in large office buildings and the impact of discomfort glare}, booktitle = {Fourth BEST Conference Building Enclosure Science \& Technology (BEST4)}, year = {2015}, month = {04/2015}, address = {Kansas City, Missouri}, abstract = {

Exterior shades are highly efficient for reducing solar load in commercial buildings. Their impact on net energy use depends on the annual energy balance of heating, cooling, fan and lighting energy. This paper discusses the overall energy use intensity of various external shading systems for a prototypical large office building split into the different types of energy use and for different orientations and window sizes. Lighting energy was calculated for a constant lighting power as well as for dimmed lighting fixtures (daylighting control).

In Section 3, slat angles and solar cut-off angles were varied for fixed exterior slat shading systems. While the most light-blocking shades performed best for the case without daylighting controls, the optimum cut-off angle with daylighting controls was found to be 30 deg for the office building prototype used in Chicago and Houston. For large window-to-wall (WWR) ratios, window related annual energy use could be reduced by at least 70 \% without daylighting control and by a minimum of 86 \% with daylighting control in average over all orientations.

The occurrence of discomfort glare was is considered in Section 4 of the paper, which looks at the performance of commercially available exterior shading systems when an interior shade is used in addition to the exterior shade during hours when occupants would experience discomfort glare. Glare control impacts overall energy use intensity significantly for exterior shades with high transmittance, especially when daylighting controls are used. In these cases, exterior shades are only beneficial for window-to-wall areas >= 45\% in the hot Houston climate. For smaller windows and in a heating/cooling climate like Chicago, exterior shades can increase energy consumption.

}, author = {Sabine Hoffmann and Eleanor S. Lee} } @techreport {60935, title = {A Pilot Demonstration of Electrochromic and Thermochromic Windows in the Denver Federal Center, Building 41, Denver, Colorado}, year = {2013}, note = {

Completed September 30, 2012, released March 30, 2014.

}, month = {07/2013}, abstract = {

Chromogenic glazing materials are emerging technologies that tint reversibly from a clear to dark tinted state either passively in response to environmental conditions or actively in response to a command from a switch or building automation system. Switchable coatings on glass manage solar radiation and visible light while enabling unobstructed views to the outdoors. Building energy simulations estimate that actively controlled, near-term chromogenic glazings can reduce perimeter zone heating, ventilation, and air- conditioning (HVAC) and lighting energy use by 10-20\% and reduce peak electricity demand by 20-30\%, achieving energy use levels that are lower than an opaque, insulated wall.

This project demonstrates the use of two types of chromogenic windows: thermochromic and electrochromic windows. By 2013, these windows will begin production in the U.S. by multiple vendors at high-volume manufacturing plants, enabling lower cost and larger area window products to be specified. Both technologies are in the late R\&D stage of development, where cost reductions and performance improvements are underway. Electrochromic windows have been installed in numerous buildings over the past four years, but monitored energy-efficiency performance has been independently evaluated in very limited applications. Thermochromic windows have been installed in one other building with an independent evaluation, but results have not yet been made public.

}, keywords = {building controls, daylighting, Demand Side Management, electrochromic, energy-efficiency, Smart windows, switchable windows, Thermochromic, Window}, url = {http://gsa.gov/portal/content/187967}, author = {Eleanor S. Lee and Luis L. Fernandes and Howdy Goudey and Jacob C. Jonsson and Dragan C. Curcija and Xiufeng Pang and Dennis L. DiBartolomeo and Sabine Hoffmann} } @techreport {3441, title = {A Post-Occupancy Monitored Evaluation of the Dimmable Lighting, Automated Shading, and Underfloor Air Distribution System in The New York Times Building}, year = {2013}, month = {01/2013}, institution = {Lawrence Berkeley National Laboratory}, address = {Berkeley, CA}, abstract = {

With aggressive goals to reduce national energy use and carbon emissions, the US Department of Energy will be looking to exemplary buildings that have already invested in new approaches to achieving the energy performance goals now needed at a national level. The New York Times Building, in New York, New York, incorporates a number of innovative technologies, systems and processes and could become a model for widespread replication in new and existing buildings. Post-occupancy data are invaluable in establishing confidence in innovation. A year-long monitored study was conducted to verify energy performance, assess occupant comfort and satisfaction with the indoor environment, and evaluate impacts on maintenance and operations. Lessons learned were derived from the analysis; these lessons could help identify and shape policy, financial, or supporting strategies to accelerate diffusion in the commercial building market.

}, author = {Eleanor S. Lee and Luis L. Fernandes and Brian E. Coffey and Andrew McNeil and Robert D. Clear and Thomas L. Webster and Fred S. Bauman and Darryl J. Dickerhoff and David Heinzerling and Tyler Hoyt} } @techreport {3419, title = {A Practical Framework for Sharing and Rendering Real-World Bidirectional Scattering Distribution Functions}, year = {2012}, month = {10/2012}, abstract = {

The utilization of real-world materials has been hindered by a lack of standards for sharing and interpreting measured data. This paper presents an XML representation and an Open Source C library to support bidirectional scattering distribution functions (BSDFs) in data-driven lighting simulation and rendering applications.The library provides for the efficient representation, query, and Monte Carlo sampling of arbitrary BSDFs in amodel-free framework. Currently, we support two BSDF data representations: one using a fixed subdivision of thehemisphere, and one with adaptive density. The fixed type has advantages for certain matrix operations, while theadaptive type can more accurately represent highly peaked data. We discuss advanced methods for data-driven BSDF rendering for both types, including the proxy of detailed geometry to enhance appearance and accuracy. We also present an advanced interpolation method to reduce measured data into these standard representations. We end with our plan for future extensions and sharing of BSDF data.

}, keywords = {building technology and urban systems department, windows and envelope materials group}, author = {Gregory J. Ward and Murat Kurt and Nicolas Bonneel} } @article {12172, title = {Performance of Integrated Systems of Automated Roller Shade Systems and Daylight Responsive Dimming Systems}, journal = {Building and Environment}, volume = {46}, year = {2011}, month = {03/2011}, pages = {747-757}, chapter = {747}, abstract = {

Daylight responsive dimming systems have been used in few buildings to date because they require improvements to improve reliability. The key underlying factor contributing to poor performance is the variability of the ratio of the photosensor signal to daylight workplane illuminance in accordance with sun position, sky condition, and fenestration condition. Therefore, this paper describes the integrated systems between automated roller shade systems and daylight responsive dimming systems with an improved closed-loop proportional control algorithm, and the relative performance of the integrated systems and single systems. The concept of the improved closed-loop proportional control algorithm for the integrated systems is to predict the varying correlation of photosensor signal to daylight workplane illuminance according to roller shade height and sky conditions for improvement of the system accuracy. In this study, the performance of the integrated systems with two improved closed-loop proportional control algorithms was compared with that of the current (modified) closed-loop proportional control algorithm. In the results, the average maintenance percentage and the average discrepancies of the target illuminance, as well as the average time under 90\% of target illuminance for the integrated systems significantly improved in comparison with the current closed-loop proportional control algorithm for daylight responsive dimming systems as a single system.

}, keywords = {automated roller shade systems, daylight responsive dimming systems, daylighting, Integrated systems, photoelectric controls}, doi = {10.1016/j.buildenv.2010.10.007}, author = {Byoung-Chul Park and An-Seop Choi and Jae-Weon Jeong and Eleanor S. Lee} } @article {58921, title = {A Plasma Lens for Magnetron Sputtering}, journal = {IEEE Transactions on Plasma Science}, volume = {39}, year = {2011}, month = {11/2011}, pages = {2528 - 2529}, abstract = {

A plasma lens, consisting of a solenoid and potential-defining ring electrodes, has been placed between a magnetron and substrates to be coated. Photography reveals qualitative information on excitation, ionization, and the transport of plasma to the substrate.

}, issn = {0093-3813}, doi = {10.1109/TPS.2011.2157172}, author = {Andr{\'e} Anders and Jeff Brown} } @techreport {58302, title = {Post Occupancy Study of The New York Times Building: Survey Findings Assessing Occupant Comfort and Satisfaction}, year = {2010}, month = {11/2010}, type = {Final report by Sustainable Energy Partnerships}, address = {Tarrytown, New York}, abstract = {

The New York Times (NY Times) building located at 620 Eighth Avenue in Manhattan was designed to include state of the art, environmentally-sustainable features intended to enhance occupant satisfaction and save energy. Some of the features in the NY Times space, including daylight dimming controls, automated window shades, and an advanced under-floor air distribution (UFAD) system, were first of their kind ventures on this scale in the US. The New York State Energy Research \& Development Authority (NYSERDA) actively supported the design and construction of this new facility with significant incentives toward the innovative features of the facility.

In order to understand occupant satisfaction and comfort levels associated with these new technologies, NYSERDA is providing support to the NY Times Facility Management staff with a simplified post occupancy review, assisting with development and analysis of an occupant satisfaction survey. The survey (survey instrument attached as Appendix 2) was intended to determine the level of occupant satisfaction with certain aspects of the indoor environmental quality of the NY Times Building, with a special focus on lighting and comfort quality provided by the innovative lighting/shading control and UFAD systems. In distributing the survey, it was stated that results from the survey would be shared with occupants, and will also inform Facilities Management in their operation of the building.

}, author = {Adam Hinge} } @techreport {58235, title = {Post-Occupancy Evaluation of The New York Times Headquarters Building: an Examination of Causes for Occupant Satisfaction and Dissatisfaction with the Energy-Efficiency Measures}, year = {2010}, month = {10/2010}, type = {DOE/LBNL Technical report}, address = {Berkeley}, abstract = {

A post-occupancy evaluation (POE) survey was issued by The New York Times (NYT) to their employees with the assistance of Sustainable Energy Partnerships (SEP). SEP conducted a detailed analysis of the survey data (September 29, 2010 draft) and found that a significant fraction of the building occupants were satisfied to very satisfied with the overall building. Compared to other buildings, the overall level of satisfaction was greater than the norm of surveyed buildings.

This additional analysis was conducted to identify potential causes of the occupants{\textquoteright} satisfaction or dissatisfaction with the innovative lighting, shading, and space- conditioning systems themselves and/or the resultant indoor environment produced by these systems. The analysis used various methods to identify statistically significant factors, where the factors were those given in the survey questionnaire. Additional factors or causes of satisfaction and dissatisfaction were identified through analysis of the detailed comments: this was done for the questions related to the lighting section of the survey.

}, author = {Robert D. Clear} } @article {58226, title = {Phase transitions in non-hydride switchable mirror thin films}, journal = {Phase Transitions}, volume = {81}, year = {2008}, month = {07/2008}, pages = {807 - 813}, abstract = {

Switchable mirrors modulate incident light by changes in the reflectivity of thin films that are converted by chemical reactions from a metallic reflective state to a semiconducting transparent state. The reactions may be effected by exposure to a gas, by treatment with a liquid reagent, or by electrochemical means. The changes in optical properties coincide with phase transformations. In the examples reviewed here, the reactions are accompanied by substantial volume changes and atomic rearrangement. Bismuth, antimony, and antimony alloy films are switched by electrochemical lithiation. Copper films are electrochemically oxidized to Cu(I) and Cu(II) oxides, which are transparent and opaque, respectively. Morphological changes in all films during cycling lead to degradation in performance without loss of active material. Strategies to improve the cycling stability of these systems are discussed.

}, keywords = {electrochromism, optoelectronics, Switchable mirrors, thin films}, issn = {0141-1594}, doi = {10.1080/01411590801911406}, author = {Thomas J. Richardson} } @article {12182, title = {Physical properties of erbium implanted tungsten oxide films deposited by reactive dual magnetron sputtering}, journal = {Thin Solid Films}, volume = {515}, number = {8}, year = {2007}, month = {05/2007}, pages = {5264-5269}, chapter = {5264}, abstract = {

Amorphous and partially crystalline WO3 thin films were prepared by reactive dual magnetron sputtering and successively implanted by erbium ions with a fluence in the range from 7.7 x 1014 to 5 x 1015 ions/cm2. The electrical and optical properties were studied as a function of the film deposition parameters and the ion fluence. Ion implantation caused a strong decrease of the resistivity, a moderate decrease of the index of refraction and a moderate increase of the extinction coefficient in the visible and near infrared, while the optical band gap remained almost unchanged. These effects could be largely ascribed to ion-induced oxygen deficiency. When annealed in air, the already low resistivities of the implanted samples decreased further up to 70{\textdegree}C, whereas oxidation, and hence a strong increase of the resistivity, was observed at higher annealing temperatures

}, keywords = {Dual magnetron sputtering, electrical resistivity, Er ion implantation, optical properties, tungsten oxide films}, doi = {10.1016/j.tsf.2006.12.179}, author = {Sodky H. Mohamed and Andr{\'e} Anders} } @conference {1731, title = {Physics of High Power Impulse Magnetron Sputtering}, booktitle = {ISSP2007: The 9th International Symposium on Sputtering \& Plasma Processes}, year = {2007}, abstract = {

High power impulse magnetron sputtering is characterized by discharge pulses whose target power density exceeds conventional sputtering power densities by two orders of magnitude or more; the goal is to provide a large flux of ionized sputtered material. The processes of pulse evolution are briefly reviewed, including secondary electron emission, self-sputtering, and rarefaction. Using a pulse power supply capable of providing constant voltage for target peak power densities up to 5 kW/cm2, the evolution of the current-voltage characteristics was investigated for copper and titanium. It is shown that the characteristic cannot be reduced to value pairs. Rather, a strong but reproducible development exists. The details depend on the argon pressure and applied voltage. Each target material exhibits a distinct and sharp transition to a high current regime that appears to be dominated by metal plasma. Despite the higher sputter yields for copper, the transition to the high current regime occurs much earlier and stronger for titanium, which may be attributed to a higher secondary electron yield and hence a higher density of electrons confined in the magnetron structure. At high currents, the closed-drift Hall current generates a magnetic field that weakens plasma confinement, thereby enabling large ion currents to reach a biased substrate.

}, author = {Andr{\'e} Anders and Joakim Andersson and David Horwat and Arutiun P. Ehiasarian} } @conference {1732, title = {Plasma and Ion Assistance in Physical Vapor Deposition: A Historical Perspective}, booktitle = {50th Technical Annual Meeting of the Society of Vacuum Coaters}, year = {2007}, abstract = {

Deposition of films using plasma or plasma-assist can be traced back surprisingly far, namely to the 18th century for arcs and to the 19th century for sputtering. However, only since the 1960s the coatings community considered other processes than evaporation for large scale commercial use. Ion Plating was perhaps the first important process, introducing vapor ionization and substrate bias to generate a beam of ions arriving on the surface of the growing film. Rather independently, cathodic arc deposition was established as an energetic condensation process, first in the former Soviet Union in the 1970s, and in the 1980s in the Western Hemisphere.

About a dozen various ion-based coating technologies evolved in the last decades, all characterized by specific plasma or ion generation processes. Gridded and gridless ion sources were taken from space propulsion and applied to thin film deposition. Modeling and simulation have helped to make plasma and ions effects to be reasonably well understood. Yet{\textemdash}due to the complex, often non-linear and non-equilibrium nature of plasma and surface interactions{\textemdash}there is still a place for the experienced ion and plasma "sourcerer."

}, author = {Andr{\'e} Anders} } @conference {12166, title = {Performance Criteria for Residential Zero Energy Windows}, booktitle = {2007 ASHRAE Winter Meeting}, year = {2006}, month = {01/2007}, address = {Dallas, TX}, abstract = {

This paper shows that the energy requirements for today{\textquoteright}s typical efficient window products (i.e. ENERGY STAR products) are significant when compared to the needs of Zero Energy Homes (ZEHs). Through the use of whole house energy modeling, typical efficient products are evaluated in five US climates and compared against the requirements for ZEHs. Products which meet these needs are defined as a function of climate. In heating dominated climates, windows with U-factors of 0.10 Btu/hr-ft2-F (0.57 W/m2-K) will become energy neutral. In mixed heating/cooling climates a low U-factor is not as significant as the ability to modulate from high SHGCs (heating season) to low SHGCs (cooling season).

}, author = {Dariush K. Arasteh and Howdy Goudey and Yu Joe Huang and Christian Kohler and Robin Mitchell} } @article {12188, title = {Plasma biasing to control the growth conditions of diamond-like carbon}, journal = {Surface and Coatings Technology}, volume = {201}, year = {2006}, month = {01/2007}, pages = {4628-4632}, chapter = {4628}, abstract = {

It is well known that the structure and properties of diamond-like carbon, and in particular the sp3/sp2 ratio, can be controlled by the energy of the condensing carbon ions or atoms. In many practical cases, the energy of ions arriving at the surface of the growing film is determined by the bias applied to the substrate. The bias causes a sheath to form between substrate and plasma in which the potential difference between plasma potential and surface potential drops. In this contribution, we demonstrate that the same results can be obtained with grounded substrates by shifting the plasma potential. This plasma biasing (as opposed to substrate biasing) is shown to work well with pulsed cathodic carbon arcs, resulting in tetrahedral amorphous carbon (ta-C) films that are comparable to the films obtained with the conventional substrate bias. To verify the plasma bias approach, ta-C films were deposited by both conventional and plasma bias and characterized by transmission electron microscopy (TEM) and electron energy loss spectrometry (EELS). Detailed data for comparison of these films are provided.

}, keywords = {Diamond-like carbon films, Electron energy loss spectroscopy, Plasma bias, Substrate bias, transmission electron microscopy}, doi = {10.1016/j.surfcoat.2006.09.313}, author = {Andr{\'e} Anders and Nitisak Pasaja and Sunnie H.N. Lim and Tim C. Petersen and Vicki J. Keast} } @article {12184, title = {Physics of Arcing, and Implications to Sputter Deposition}, journal = {Thin Solid Films}, year = {2005}, abstract = {

Arcing on sputter targets and negatively biased substrates is known as one of the most challenging issues in physical vapor deposition of thin films and coatings. This is particularly true when high-rate deposition with reactive gases, large area deposition, and high power pulsed sputtering are considered. Much progress has been made in the development of power supplies that can handle arcing events with minimal damage to target and substrate. However, relatively little is known about the processes leading to arcs and the physics of the arcing events themselves. In this contribution, the issue of arcing is approached from the point of view of arc physics. Current knowledge of arcing and arc suppression is reviewed.

(Note: PDF contains both LBNL-54220 \& LBNL-54220 Journal.)

}, author = {Andr{\'e} Anders} } @conference {12187, title = {Plasma and Ion Sources in Large Area Coatings: A Review}, year = {2005}, abstract = {

Efficient deposition of high-quality coatings often requires controlled application of excited or ionized particles. These particles are either condensing (film-forming) or assisting by providing energy and momentum to the film growth process, resulting in densification, sputtering/etching, modification of stress, roughness, texture, etc. In this review, the technical means are surveyed enabling large area application of ions and plasmas, with ion energies ranging from a few eV to a few keV. Both semiconductor-type large area (single wafer or batch processing with ~ 1000 cm2) and in-line web and glass-coating-type large area (\> 107 m2 annually) are considered. Characteristics and differences between plasma and ion sources are explained. The latter include gridded and gridless sources. Many examples are given, including sources based on DC, RF, and microwave discharges, some with special geometries like hollow cathodes and E x B configurations.

}, author = {Andr{\'e} Anders} } @article {12189, title = {Plasma-Based Ion Implantation and Deposition: A Review of Physics, Technology, and Applications}, journal = {IEEE Transactions on Plasma Science}, volume = {33}, number = {6}, year = {2005}, pages = {1944-1959}, abstract = {

After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modelling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and chemically inert phases and coatings, e.g. for engine components. PBII has become viable for the formation of shallow junctions and other applications in microelectronics. More recently, the rapidly growing field of biomaterial synthesis makes used of PBII\&D to produce surgical implants, bio- and blood-compatible surfaces and coatings, etc. With limitations, also non-conducting materials such as plastic sheets can be treated. The major interest in PBII processing originates from its flexibility in ion energy (from a few eV up to about 100 keV), and the capability to efficiently treat, or deposit on, large areas, and (within limits) to process non-flat, three-dimensional workpieces, including forming and modifying metastable phases and nanostructures. We use the acronym PBII\&D when referring to both implantation and deposition, while PBIID implies that deposition is part of the process.

}, author = {Jacques Pelletier and Andr{\'e} Anders} } @conference {58262, title = {Perspectives on Advanced Fa{\c c}ades with Dynamic Glazings and Integrated Lighting Controls}, booktitle = {CISBAT 2003, Innovation in Building Envelopes and Environmental Systems, International Conferences on Solar Energy in Buildings}, year = {2003}, month = {10/2003}, address = {Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland}, abstract = {

There is growing interest in North America on the subject of highly glazed building fa{\c c}ades. The concept of a smart, interactive fa{\c c}ade is not new {\textendash} the ability of specific fa{\c c}ade systems to work reliably and effectively is a far greater challenge. We have been exploring various dynamic fa{\c c}ade systems with integrated lighting and HVAC over the last 10 years. These include automated blind systems as well as emerging electrochromic glazings, both with automated dimmable lighting and smart controls. More recently we have extended this work to include internet-based control of lights, blinds and glazings using low cost chips embedded in fixtures, motors, and glazing controls. As each window and lighting element becomes a node on the internet they can be controlled via the existing building energy management system either from an occupants desktop computer, an on-site facility manager or even from a remote location. Recent experience in California with disruptions in electric supply and costly peak power suggest value for such capabilities. This paper briefly summaries the state of recent work in this field, describing a new facility with three side-by-side test rooms in Berkeley to test new electrochromic window prototypes, and identifies key performance, systems integration and cost issues now being studied. The authors bring a cross section of both North American and European experience to address the many technology, design and business issues involved.

}, author = {Stephen E. Selkowitz and Eleanor S. Lee and {\O}yvind Aschehoug} } @conference {12183, title = {Physics of Arcing, and Implications to Sputter Deposition}, booktitle = {International Conference on Coatings on Glass}, year = {2003}, month = {07/2004}, address = {Saarbrucken, Germany}, abstract = {

Arc and glow discharges are defined based on their cathode processes. Arcs are characterized by collective electron emission, which can be stationary with hot cathodes (thermionic arcs), or nonstationary with cold cathodes (cathodic arcs). A brief review on cathodic arc properties serves as the starting point to better understand arcing phenomena in sputtering. Although arcing occurs in both metal and reactive sputtering, it is more of an issue in the reactive case. Arcing occurs if sufficiently high field strength leads to thermal runaway of an electron emission site. The role of insulating layers and surface potential adjustment through current leakage is highlighted. In the situation of magnetron sputtering with racetrack, the need for a model with two spatial dimensions is shown. In many cases, arcing is initiated by breakdown of dielectric layers and inclusions. It is most efficiently prevented if formation and excessive charge-up of dielectric layers and inclusions can be avoided.

(Note: PDF contains both LBNL-54220 \& LBNL-54220 Journal.)

}, author = {Andr{\'e} Anders} } @article {12196, title = {Pressure Controlled GaN MBE Growth Using a Hollow Anode Nitrogen Ion Source}, journal = {Materials Research Society Proceedings}, volume = {449}, year = {1997}, note = {

1996 MRS Fall Meeting

}, abstract = {

GaN films were grown on sapphire substrates at temperatures below 1000 K utilizing a Hollow Anode nitrogen ion source. A Ga flux limited growth rate of ~0.5 μm/h is demonstrated. Active utilization of strain and the assistance of a nitrogen partial pressure during buffer layer growth are found to be crucial issues that can improve the film quality. The best films exhibit a full width at half maximum of the x-ray rocking curves of 80 arcsec and 1.85 meV for the excitonic photoluminescence measured at 4 K. A Volmer-Weber three dimensional growth mode and the spontaneous formation of cubic GaN inclusions in the hexagonal matrix are observed in the investigated growth temperature range. It is argued that this growth mode contributes to a limitation of the carrier mobility in these films that did not exceed 120 cm2/Vs through a minimum canier concentration of ~1015 cm-3 was achieved.

}, doi = {10.1557/PROC-449-221}, author = {Michael S.H. Leung and Ralf Klockenbrink and Christian F. Kisielowski and Hiroaki Fujii and Joachim Kr{\"u}ger and Sudhir G. Subramanya and Andr{\'e} Anders and Zuzanna Liliental-Weber and Michael D. Rubin and Eicke R. Weber}, editor = {Joachim Kr{\"u}ger} } @article {12195, title = {Preparation and Properties of Spin-Coated Nb2O5 Films by the Sol-Gel Process for Electrochemical Applications}, journal = {Thin Solid Films}, volume = {277}, number = {2-Jan}, year = {1995}, month = {05/1996}, pages = {162-168}, chapter = {162}, abstract = {

The preparation and properties of Nb2O5 coatings made by the sol-gel process were investigated. The films were deposited by spin coating on In2O3:Sn/glass and quartz substrates from a polymeric solutions of niobia derived from niobium ethoxide. The films were characterized by investigation of the stoichiometry, refractive index, optical transmission, electrochemical behavior, and the microstructure. X-ray diffraction studies showed the films to be amorphous for heat treatments below 450 {\textdegree}C. X-ray photoelectron spectroscopy (XPS) measurement revealed the O:Nb atomic stoichiometry to be 5:2. Cyclic voltammetric measurements showed that the Nb2O5/1 M LiClO4-propylene carbonate system exhibits electrochemical reversibility beyond 1200 cycles without change in performance. In situ UV-Vis-NIR spectroelectrochemical measurement revealed that Nb2O5 films exhibit an electrochromic effect in the spectral range 300\<λ\<2100 nm and remain unchanged in the infrared spectral range. The change in visible transmittance was 40\% for a 250 nm thick electrode. XPS spectra indicate that Nb(V) is reduced to a lower valence state Nb(IV) in a colored state with injected Li+. The bronze coloration is due to a simultaneous injection of electrons and Li+ ions into Nb2O5. The sol-gel-deposited\ Nb2O5 films are useful for cathodically coloring electrochromic electrodes in electrochromic devices.

}, keywords = {Electrochemistry, Niobium oxide, optical properties, X-ray photoelectron spectroscopy}, url = {http://dx.doi.org/10.1016/0040-6090(95)08011-2}, author = {Nilg{\"u}n {\"O}zer and Din-Guo Chen and Carl M Lampert} } @article {12175, title = {Phase I Results of the NFRC U-Value Procedure Validation Project}, journal = {ASHRAE Transactions}, volume = {100, Pt. 1}, number = {Part 1}, year = {1993}, month = {08/1993}, abstract = {

The NFRC U-Value Procedure Validation Project was undertaken by a collaborative group of industry, public utility, trade associations, and government researchers in order to validate the testing and calculational methods of the NFRC 100-91: Procedure for Determining Fenestration Product Thermal Properties (Currently Limited to U-Values). This paper summarizes the validation projects goals and test methodology, the results of the data analysis, and the recommendations following completion of Phase I of the project. Simulations performed according to NFRC 100-91 are shown to agree with each other, to within the NFRC tolerance, in 100\% of the cases. Window test results with perpendicular wind performed according to NFRC 100-91 are shown to agree with each other, to within the NFRC tolerance, in 84\% of the cases. Simulations and perpendicular wind window test results are shown to agree with each other, to within the NFRC tolerance, in 80\% of the cases. Testing of skylights was shown to be problematic under the procedure as written at the time. Agreement between tests and simulations will improve as a result of a strong NFRC education and accreditation program.

}, author = {Dariush K. Arasteh and Fredric A. Beck and Nehemiah Stone and William DuPont and R. Christophe Mathis and Michael Koenig} } @article {12159, title = {P-Type Gallium Nitride by Reactive Ion-Beam Molecular Beam Epitaxy with Ion Implantation, Diffusion or Coevaporation of Mg}, journal = {Applied Physics Letters}, volume = {64}, number = {1}, year = {1993}, pages = {64-66}, chapter = {64}, abstract = {

Gallium nitride is one of the most promising materials for ultraviolet and blue light-emitting diodes and lasers. The principal technical problem that limits device applications has been achieving controllable p-type doping. Molecular beam epitaxy assisted by a nitrogen ion beam produced p-type GaN when doped via ion implantation, diffusion, or coevaporation of Mg. Nearly intrinsic p-type material was also produced without intentional doping, exhibiting hole carrier concentrations of 5{\texttimes}1011 cm-3 and hole mobilities of over 400 cm2/V/s at 250 K. This value for the hole mobility is an order of magnitude greater than previously reported.

}, keywords = {carrier density, carrier mobility, crystal doping, diffusion, evaporation, gallium nitrides, ion implantation, magnesium additions, molecular beam epitaxy, p-type conductors}, issn = {0003-6951}, doi = {10.1063/1.110870}, author = {Michael D. Rubin and Nathan Newman and James S. Chan and T.C. Fu and Jennifer T. Ross} } @techreport {1724, title = {Photoelectric Control of Daylight-Following Lighting Systems}, year = {1989}, month = {02/1989}, abstract = {

The ability of daylight-following lighting systems to provide a minimum specified light level at the task surface is influenced by 1) the control algorithm used, 2) the spatial response of the ceiling-mounted control photosensor and 3) the location of the photosensor relative to task and window. Best performance was obtained with a closed-loop proportional control system controlled by a photosensor, with a large field of view but shielded from direct light from the window. A minimum specified illuminance level could be maintained at specific points on the task surface regardless of daylight condition or room geometry provided that the system gain was properly calibrated to account for the local luminous environment.

Open-loop proportional control also performed adequately but offered less precise control than closed-loop systems due to the necessity of using a photosensor that was not shielded from direct window light. Integral-reset systems that were tested performed poorly, but performance could be improved slightly by completely shielding the photocell from direct window light.

}, author = {Francis M. Rubinstein and Rudolph R. Verderber and Gregory J. Ward} } @article {12177, title = {Photo-Electric Control of Equi-Illumination Lighting Systems}, journal = {Energy and Buildings}, volume = {6}, year = {1983}, pages = {141-150}, abstract = {

A complete analysis of the cost-effectiveness of daylighting strategies should include the impact of daylighting on peak electrical demand as well as on energy consumption. We utilized an hour-by-hour building energy analysis program to study the thermal and daylighting impacts of fenestration on peak demand. Fenestration properties and lighting system characteristics were varied parametrically for office buildings in Madison WI and Lake Charles LA. Peak electrical demand was disaggregated by component and by zone, monthly patterns of peak demand were examined, and impacts of fenestration performance on chiller size were studied. The results suggest that for daylighted office buildings, the peak electrical demand results from a complex trade-off between cooling load due to fenestration parameters, lighting load reductions due to glazing and lighting system characteristics. Lowest peak demands generally occur with small to moderate size apertures. With daylighting, peak electrical demand is reduced by 10 to 20\% for the building configuration studied (37\% perimeter zone, 63\% core zone). This work indicates that solar gain through fenestration must be effectively controlled in order to realize the potential of daylighting to significantly reduce peak electrical demand.

}, author = {Francis M. Rubinstein} }