Short-term airing by natural ventilation - implication on IAQ and thermal comfort.

PubMed

Heiselberg, P; Perino, M

2010-04-01

The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. Among the available ventilation strategies that are currently available, buoyancy driven, single-sided natural ventilation has proved to be very effective and can provide high air change rates for temperature and Indoor Air Quality (IAQ) control. However, to promote a wider distribution of these systems an improvement in the knowledge of their working principles is necessary. The present study analyses and presents the results of an experimental evaluation of airing performance in terms of ventilation characteristics, IAQ and thermal comfort. It includes investigations of the consequences of opening time, opening frequency, opening area and expected airflow rate, ventilation efficiency, thermal comfort and dynamic temperature conditions. A suitable laboratory test rig was developed to perform extensive experimental analyses of the phenomenon under controlled and repeatable conditions. The results showed that short-term window airing is very effective and can provide both acceptable IAQ and thermal comfort conditions in buildings. Practical Implications This study gives the necessary background and in-depth knowledge of the performance of window airing by single-sided natural ventilation necessary for the development of control strategies for window airing (length of opening period and opening frequency) for optimum IAQ and thermal comfort in naturally ventilated buildings.

A performance comparison of nuclear electric and nuclear thermal propulsion for Mars cargo missions across the 15-17 year synodic cycle

NASA Technical Reports Server (NTRS)

Sponaugle, Steven J.; Davis, Steven F.; Everett, Shonn F.

1992-01-01

This paper examines the effects of the Earth-Mars synodic cycle on Mars cargo missions. Cargo vehicles that use nuclear thermal propulsion are compared with those that use nuclear electric propulsion. It will be shown that for low energy class cargo missions, nuclear electric systems exhibit far less variation in peak performance over the synodic cycle than comparable nuclear thermal systems. Performance is measured by the amount of usable mass delivered to Mars, as well as the initial mass requirements in nuclear safe orbit. Nuclear electric propulsion systems also have significantly longer injection window opportunities for a given 26 month synodic period, resulting in much greater mission design flexibility. Injection window opportunities over a 20 year period from 2010 to 2030 are examined. This covers a complete synodic cycle and shows its effects on performance for Mars cargo missions.

Low-E Retrofit Demonstration and Educational Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Culp, Thomas D; Wiehagen, Joseph; Drumheller, S Craig

The objective of this project was to demonstrate the capability of low-emissivity (low-E) storm windows / panels and low-E retrofit glazing systems to significantly and cost effectively improve the energy efficiency of both existing residential and commercial buildings. The key outcomes are listed below: RESIDENTIAL CASE STUDIES: (a) A residential case study in two large multifamily apartment buildings in Philadelphia showed a substantial 18-22% reduction in heating energy use and a 9% reduction in cooling energy use by replacing old clear glass storm windows with modern low-E storm windows. Furthermore, the new low-E storm windows reduced the overall apartment airmore » leakage by an average of 10%. (b) Air leakage testing on interior low-E panels installed in a New York City multifamily building over windows with and without AC units showed that the effective leakage area of the windows was reduced by 77-95%. (c) To study the use of low-E storm windows in a warmer mixed climate with a balance of both heating and cooling, 10 older homes near Atlanta with single pane windows were tested with three types of exterior storm windows: clear glass, low-E glass with high solar heat gain, and low-E glass with lower solar heat gain. The storm windows significantly reduced the overall home air leakage by an average of 17%, or 3.7 ACH50. Considerably high variability in the data made it difficult to draw strong conclusions about the overall energy usage, but for heating periods, the low-E storm windows showed approximately 15% heating energy savings, whereas clear storm windows were neutral in performance. For cooling periods, the low-E storm windows showed a wide range of performance from 2% to over 30% cooling energy savings. Overall, the study showed the potential for significantly more energy savings from using low-E glass versus no storm window or clear glass storm windows in warmer mixed climates, but it is difficult to conclusively say whether one type of low-E performed better than the other. COMMERCIAL CASE STUDIES: (a) A 12-story office building in Philadelphia was retrofitted by adding a double-pane low-E insulating glass unit to the existing single pane windows, to create a triple glazed low-E system. A detailed side-by-side comparison in two pairs of perimeter offices facing north and east showed a 39-60% reduction in heating energy use, a 9-36% reduction in cooling energy use, and a 10% reduction in peak electrical cooling demand. An analysis of utility bills estimated the whole building heating and cooling energy use was reduced by over 25%. Additionally, the retrofit window temperatures were commonly 20 degrees warmer on winter days, and 10-20 degrees cooler on summer days, leading to increased occupant comfort. (b) Two large 4-story office buildings in New Jersey were retrofitted with a similar system, but using two low-E coatings in the retrofit system. The energy savings are being monitored by a separate GPIC project; this work quantified the changes in glass surface temperatures, thermal comfort, and potential glass thermal stress. The low-E retrofit panels greatly reduced daily variations in the interior window surface temperatures, lowering the maximum temperature and raising the minimum temperature by over 20F compared to the original single pane windows with window film. The number of hours of potential thermal discomfort, as measured by deviation between mean radiant temperature and ambient air temperature by more than 3F, were reduced by 93 percent on the south orientation and over two-thirds on the west orientation. Overall, the low-E retrofit led to substantially improved occupant comfort with less periods of both overheating and feeling cold. (c) No significant thermal stress was observed in the New Jersey office building test window when using the low-E retrofit system over a variety of weather conditions. The surface temperature difference only exceeded 10F (500 psi thermal stress) for less than 1.5% of the monitored time, and in all cases, the maximum surface temperature difference never exceeded 35F (1,750 psi thermal stress). LOW-E STORM WINDOW OUTREACH AND EDUCATION PROGRAM: (a) The project team assisted the State of Pennsylvania in adding low-E storm windows as a cost effective weatherization measure on its priority list for the state weatherization assistance program. (b) No technical barriers that could hinder widespread application were identified in the case studies. However, educational barriers have been identified, in that weatherization personnel commonly misunderstand how the application of low-E storm windows is very different than much more expensive full window replacement. (c) A package of educational materials was developed to help communicate the benefits of low-E storm windows and retrofits as a cost effective tool for weatherization personnel. (d) Using detailed thermal simulations, more accurate U-factor and solar heat gain coefficient (SHGC) values were determined for low-E storm windows installed over different primary windows. IN SUMMARY, this work confirmed the potential for low-E storm windows, panels, and retrofit systems to provide significant energy savings, reductions in air leakage, and improvements in thermal comfort in both residential and commercial existing buildings.« less

Evaluation of Cellular Shades in the PNNL Lab Homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, Joseph M.; Sullivan, Greg; Cort, Katherine A.

This report examines the energy performance of cellular shade window coverings in a matched pair of all-electric, factory-built “Lab Homes” located on the Pacific Northwest National Laboratory (PNNL) campus in Richland, Washington. The 1500-square-foot homes were identical in construction and baseline performance, which allowed any difference in energy and thermal performance between the baseline home and the experimental home to be attributed to the retrofit technology installed in the experimental home. To assess the performance of high efficiency window attachments in a residential retrofit application, the building shell air leakage, energy use, and interior temperatures of each home were comparedmore » during the 2015 -2016 winter heating and summer cooling seasons. Hunter Douglas Duette® Architella® Trielle™ opaque honeycomb “cellular” shades were installed over double-pane clear-glass, aluminum-frame primary windows in the experimental home and were compared to identical primary windows with no window coverings and with standard typical white vinyl horizontal blind window coverings in the baseline home.« less

Influence of coatings on the thermal and mechanical processes at insulating glass units

NASA Astrophysics Data System (ADS)

Penkova, Nina; Krumov, Kalin; Surleva, Andriana; Geshkova, Zlatka

2017-09-01

Different coatings on structural glass are used in the advances transparent facades and window systems in order to increase the thermal performance of the glass units and to regulate their optical properties. Coated glass has a higher absorptance in the solar spectrum which leads to correspondent higher temperature in the presence of solar load compared to the uncoated one. That process results in higher climatic loads at the insulating glass units (IGU) and in thermal stresses in the coated glass elements. Temperature fields and gradients in glass panes and climatic loads at IGU in window systems are estimated at different coating of glazed system. The study is implemented by numerical simulation of conjugate heat transfer in the window systems at summer time and presence of solar irradiation, as well as during winter night time.

Acoustical and thermal performance of exterior residential walls, doors, and windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabine, H.J.; Lacher, M.B.; Flynn, D.R.

1975-11-01

Laboratory tests of sound transmission loss, thermal transmittance, and rate of air leakage were conducted on full scale (9 feet high x 14 feet wide; 2.7 x 4.3 meters) specimens of typical residential exterior wall constructions, either unbroken or penetrated by a door or window. The walls were of wood frame construction with gypsum board drywall interior finish and exterior finishes of wood siding, stucco, or brick veneer. Additional accoustical tests were run on a number of individual doors and windows. A total of 109 acoustical tests and 48 thermal tests are reported. The resultant data are compared with literaturemore » data on similar constructions. Correlations developed among the several quantities measured will assist more rational design where both energy conservation and noise isolation must be considered. (130 references) (auth)« less

Data resulting from the CFD analysis of ten window frames according to the UNI EN ISO 10077-2.

PubMed

Baglivo, Cristina; Malvoni, Maria; Congedo, Paolo Maria

2016-09-01

Data are related to the numerical simulation performed in the study entitled "CFD modeling to evaluate the thermal performances of window frames in accordance with the ISO 10077" (Malvoni et al., 2016) [1]. The paper focuses on the results from a two-dimensional numerical analysis for ten frame sections suggested by the ISO 10077-2 and performed using GAMBIT 2.2 and ANSYS FLUENT 14.5 CFD code. The dataset specifically includes information about the CFD setup and boundary conditions considered as the input values of the simulations. The trend of the isotherms points out the different impacts on the thermal behaviour of all sections with air solid material or ideal gas into the cavities.

Thermal Stress in HFEF Hot Cell Windows Due to an In-Cell Metal Fire

DOE PAGES

Solbrig, Charles W.; Warmann, Stephen A.

2016-01-01

This work investigates an accident during the pyrochemical extraction of Uranium and Plutonium from PWR spent fuel in an argon atmosphere hot cell. In the accident, the heavy metals (U and Pu) being extracted are accidentally exposed to air from a leaky instrument penetration which goes through the cell walls. The extracted pin size pieces of U and Pu metal readily burn when exposed to air. Technicians perform the electrochemical extraction using manipulators through a 4 foot thick hot cell concrete wall which protects them from the radioactivity of the spent fuel. Four foot thick windows placed in the wallmore » allow the technicians to visually control the manipulators. These windows would be exposed to the heat of the metal fire. As a result, this analysis determines if the thermal stress caused by the fire would crack the windows and if the heat would degrade the window seals allowing radioactivity to escape from the cell.« less

Thermal Stress in HFEF Hot Cell Windows Due to an In-Cell Metal Fire

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solbrig, Charles W.; Warmann, Stephen A.

This work investigates an accident during the pyrochemical extraction of Uranium and Plutonium from PWR spent fuel in an argon atmosphere hot cell. In the accident, the heavy metals (U and Pu) being extracted are accidentally exposed to air from a leaky instrument penetration which goes through the cell walls. The extracted pin size pieces of U and Pu metal readily burn when exposed to air. Technicians perform the electrochemical extraction using manipulators through a 4 foot thick hot cell concrete wall which protects them from the radioactivity of the spent fuel. Four foot thick windows placed in the wallmore » allow the technicians to visually control the manipulators. These windows would be exposed to the heat of the metal fire. As a result, this analysis determines if the thermal stress caused by the fire would crack the windows and if the heat would degrade the window seals allowing radioactivity to escape from the cell.« less

HVI Ballistic Limit Charaterization of Fused Silica Thermal Pane

NASA Technical Reports Server (NTRS)

Bohl, William E.; Miller, Joshua E.; Christiansen, Eric L.; Deighton, Kevin.; Davis, Bruce

2015-01-01

The Orion spacecraft's windows are exposed to the micrometeroid and orbital debris (MMOD) space environments while in space as well as the Earth entry environment at the mission's conclusion. The need for a low-mass spacecraft window design drives the need to reduce conservatism when assessing the design for loss of crew due to MMOD impact and subsequent Earth entry. Therefore, work is underway at NASA and Lockheed Martin to improve characterization of the complete penetration ballistic limit of an outer fused silica thermal pane. Hypervelocity impact tests of the window configuration at up to 10 km/s and hydrocode modeling have been performed with a variety of projectile materials to enable refinement of the fused silica ballistic limit equation.

Influence of Courtyard Ventilation on Thermal Performance of Office Building in Hot-Humid Climate: A Case Study

NASA Astrophysics Data System (ADS)

Abbaas, Esra'a. Sh.; Saif, Ala'eddin A.; Munaaim, MAC; Azree Othuman Mydin, Md.

2018-03-01

The influence of courtyard on the thermal performance of Development Department office building in University Malaysia Perlis (UniMAP, Pauh Putra campus) is investigated through simulation study for the effect of ventilation on indoor air temperature and relative humidity of the building. The study is carried out using EnergyPlus simulator interface within OpenStudio and SketchUp plug in software to measure both of air temperature and relative humidity hourly on 21 April 2017 as a design day. The results show that the ventilation through the windows facing the courtyard has sufficient effect on reducing the air temperature compared to the ventilation through external windows since natural ventilation is highly effective on driving the indoor warm air out to courtyard. In addition, the relative humidity is reduced due to ventilation since the courtyard has high ability to remove or dilute indoor airborne pollutants coming from indoor sources. This indicates that the presence of courtyard is highly influential on thermal performance of the building.

Mind the Gap: Summary of Window Residential Retrofit Solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, Joseph M.; Cort, Katherine A.; Widder, Sarah H.

Improving the insulation, solar heat gain, and infiltration characteristics of windows in a home has the potential to significantly improve the overall thermal performance by reducing heat transfer through the window and also by decreasing infiltration of outdoor air into the home. As approximately 43% of existing homes still have single-pane clear windows (~50 million houses) and millions of other homes have only double-pane clear windows (Cort 2013), improving window performance also presents a significant opportunity for energy savings in the residential sector. Today, various energy-saving window retrofit opportunities are available to homeowners, ranging from window coverings and storm panelsmore » to highly-insulating triple-pane R-5 window replacements. Many of these technologies have been evaluated in the field, in the “Lab Homes” at Pacific Northwest National Laboratory, and through modeling to prove their cost-effectiveness and performance in different climate regions. Recently, the Pacific Northwest’s Regional Technical Forum approved a utility measure for low- emissivity storm windows based on such data. This action represents a watershed moment for increasing the variety and prevalence of fenestration options in utility programs, especially for the low-income demographic. This paper will review various window retrofit options, the most recent field test and modeling data regarding their performance and cost-effectiveness, and discuss future rating efforts. This information is useful for utilities and energy-efficiency program managers to help effectively implement incentive measures for these technologies.« less

Building-Integrated Solar Energy Devices based on Wavelength Selective Films

NASA Astrophysics Data System (ADS)

Ulavi, Tejas

A potentially attractive option for building integrated solar is to employ hybrid solar collectors which serve dual purposes, combining solar thermal technology with either thin film photovoltaics or daylighting. In this study, two hybrid concepts, a hybrid photovoltaic/thermal (PV/T) collector and a hybrid 'solar window', are presented and analyzed to evaluate technical performance. In both concepts, a wavelength selective film is coupled with a compound parabolic concentrator (CPC) to reflect and concentrate the infrared portion of the solar spectrum onto a tubular absorber. The visible portion of the spectrum is transmitted through the concentrator to either a thin film Cadmium Telluride (CdTe) solar panel for electricity generation or into the interior space for daylighting. Special attention is given to the design of the hybrid devices for aesthetic building integration. An adaptive concentrator design based on asymmetrical truncation of CPCs is presented for the hybrid solar window concept. The energetic and spectral split between the solar thermal module and the PV or daylighting module are functions of the optical properties of the wavelength selective film and the concentrator geometry, and are determined using a Monte Carlo Ray-Tracing (MCRT) model. Results obtained from the MCRT can be used in conjugation with meteorological data for specific applications to study the impact of CPC design parameters including the half-acceptance angle thetac, absorber diameter D and truncation on the annual thermal and PV/daylighting efficiencies. The hybrid PV/T system is analyzed for a rooftop application in Phoenix, AZ. Compared to a system of the same area with independent solar thermal and PV modules, the hybrid PV/T provides 20% more energy, annually. However, the increase in total delivered energy is due solely to the addition of the thermal module and is achieved at an expense of a decrease in the annual electrical efficiency from 8.8% to 5.8% due to shading by the absorber tubes. For this reason, the PV/T hybrid is not recommended over other options in new installations. The hybrid solar window is evaluated for a horizontal skylight and south and east facing vertical windows in Minneapolis, MN. The predicted visible transmittance for the solar window is 0.66 to 0.73 for single glazed systems and 0.61 to 0.67 for double glazed systems. The solar heat gain coefficient and the U-factor for the window are comparable to existing glazing technology. Annual thermal efficiencies of up to 24% and 26% are predicted for the vertical window and the horizontal skylight respectively. Experimental measurements of the solar thermal component of the window confirm the trends of the model. In conclusion, the hybrid solar window combines the functionality of an energy efficient fenestration system with hybrid thermal energy generation to provide a compelling solution towards sustainable design of the built environment.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Through recent research efforts, CARB has been evaluating strategies and technologies that can make dramatic improvements in energy performance in multifamily buildings. In this project, the team helped to transform a 100-year-old empty school building into 12 high performance apartments with low energy costs. The advanced features included an excellent thermal envelope of closed-cell spray foam and triple-pane windows, ductless heat pumps, solar thermal hot water system, and photovoltaic system.

Graphene Reinforced Glassy Carbon (GRGC) Beam Windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Renomeron, Lynda L.

Secondary particle beams require beam windows that isolate the target (usually in air) from the primary particle beam vacuum. Advanced beam window solutions are needed that can withstand anticipated increases in beam power and intensity that will result in higher thermal shock on the window and increased oxidative erosion rates on the air-side caused by increased temperatures. Carbon-based windows, in particular, glassy carbon windows are of interest to minimize interaction with the beam. The attractive properties of glassy carbon are: 1. Low atomic number 2. Low thermal expansion 3. High strength and low Young's modulus 4. Low gas permeability andmore » low outgassing for ultrahigh vacuum use The one liability of glassy carbon is its low thermal conductivity, nominally 5 W/mK, which will exacerbate temperature rise, oxidation, and thermal shock concerns as beam powers increase. TA&T proposes the development of graphene reinforced glassy carbon (GRGC) composites to increase the thermal conductivity and address this Achilles heel of glassy carbon. Graphene as a reinforcing phase has shown the capability to increase the thermal conductivity of the matrix material by up to two orders of magnitude. For beam windows this would substantially increase heat spreading away from the beam zone of the window and improve thermal shock resistance, and reduce maximum temperature and air-side oxidation of the window. Increased thermal conductivity would also improve the effectiveness of edge-cooling schemes to minimize temperature increase. In the Phase I effort, graphene oxide (GO) particles were dispersed into glassy carbon precursor at different content levels and cast into solid shapes. The goal was to determine the effect of graphene concentration on the mechanical properties (flexure strength), and thermal (thermal conductivity). The Phase I results indicated that addition of graphene did have a significant effect on thermal conductivity; however the microstructural properties of the composite need further improvement. The Phase II work is designed to address the processing issues found during Phase I, so as to fully realize the benefits of GO within the glassy carbon In addition to enabling improved windows for high energy particle beam experiments, the reinforced glassy carbon material will find various other applications such as thruster bodies for rocket propulsion, more durable carbon-based electrodes for electrochemistry applications, bi-polar plates for advanced batteries, catalyst support structures, and structural bio-implants.« less

Simulating the energy performance of holographic glazings

NASA Astrophysics Data System (ADS)

Papamichael, K.; Beltran, L.; Furler, Reto; Lee, E. S.; Selkowitz, Steven E.; Rubin, Michael

1994-09-01

The light diffraction properties of holographic diffractive structures present an opportunity to improve the daylight performance in side-lit office spaces by redirecting and reflecting sunlight off the ceiling, providing adequate daylight illumination up to 30 ft (9.14 m) from the window wall. Prior studies of prototypical holographic glazings, installed above conventional `view' windows, have shown increased daylight levels over a deeper perimeter area than clear glass, for selected sun positions. In this study, we report on the simulation of the energy performance of prototypical holographic glazings assuming a commercial office building in the inland Los Angeles climate. The simulation of the energy performance involved determination of both luminous and thermal performance. Since the optical complexity of holographic glazings prevented the use of conventional algorithms for the simulation of their luminous performance, we used a newly developed method that combines experimentally determined directional workplane illuminance coefficients with computer-based analytical routines to determine a comprehensive set of daylight factors for many sun positions. These daylight factors were then used within the DOE-2.1D energy simulation program to determine hourly daylight and energy performance over the course of an entire year for four window orientations. Since the prototypical holographic diffractive structures considered in this study were applied on single pane clear glass, we also simulated the performance of hypothetical glazings, assuming the daylight performance of the prototype holographic glazings and the thermal performance of double-pane and low-e glazings. Finally, we addressed various design and implementation issues towards potential performance improvement.

Occupant-responsive optimal control of smart facade systems

NASA Astrophysics Data System (ADS)

Park, Cheol-Soo

Windows provide occupants with daylight, direct sunlight, visual contact with the outside and a feeling of openness. Windows enable the use of daylighting and offer occupants a outside view. Glazing may also cause a number of problems: undesired heat gain/loss in winter. An over-lit window can cause glare, which is another major complaint by occupants. Furthermore, cold or hot window surfaces induce asymmetric thermal radiation which can result in thermal discomfort. To reduce the potential problems of window systems, double skin facades and airflow window systems have been introduced in the 1970s. They typically contain interstitial louvers and ventilation openings. The current problem with double skin facades and airflow windows is that their operation requires adequate dynamic control to reach their expected performance. Many studies have recognized that only an optimal control enables these systems to truly act as active energy savers and indoor environment controllers. However, an adequate solution for this dynamic optimization problem has thus far not been developed. The primary objective of this study is to develop occupant responsive optimal control of smart facade systems. The control could be implemented as a smart controller that operates the motorized Venetian blind system and the opening ratio of ventilation openings. The objective of the control is to combine the benefits of large windows with low energy demands for heating and cooling, while keeping visual well-being and thermal comfort at an optimal level. The control uses a simulation model with an embedded optimization routine that allows occupant interaction via the Web. An occupant can access the smart controller from a standard browser and choose a pre-defined mode (energy saving mode, visual comfort mode, thermal comfort mode, default mode, nighttime mode) or set a preferred mode (user-override mode) by moving preference sliders on the screen. The most prominent feature of these systems is the capability of dynamically reacting to the environmental input data through real-time optimization. The proposed occupant responsive optimal control of smart facade systems could provide a breakthrough in this under-developed area and lead to a renewed interest in smart facade systems.

State-of-the-Art Highly Insulating Window Frames - Research and Market Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsen, Arild; Jelle, Bjorn Petter; Arasteh, Dariush

2007-01-01

This document reports the findings of a market and research review related to state-of-the-art highly insulating window frames. The market review focuses on window frames that satisfy the Passivhaus requirements (window U-value less or equal to 0.8 W/m{sup 2}K ), while other examples are also given in order to show the variety of materials and solutions that may be used for constructing window frames with a low thermal transmittance (U-value). The market search shows that several combinations of materials are used in order to obtain window frames with a low U-value. The most common insulating material seems to be Polyurethanemore » (PUR), which is used together with most of the common structural materials such as wood, aluminum, and PVC. The frame research review also shows examples of window frames developed in order to increase the energy efficiency of the frames and the glazings which the frames are to be used together with. The authors find that two main tracks are used in searching for better solutions. The first one is to minimize the heat losses through the frame itself. The result is that conductive materials are replaced by highly thermal insulating materials and air cavities. The other option is to reduce the window frame area to a minimum, which is done by focusing on the net energy gain by the entire window (frame, spacer and glazing). Literature shows that a window with a higher U-value may give a net energy gain to a building that is higher than a window with a smaller U-value. The net energy gain is calculated by subtracting the transmission losses through the window from the solar energy passing through the windows. The net energy gain depends on frame versus glazing area, solar factor, solar irradiance, calculation period and U-value. The frame research review also discusses heat transfer modeling issues related to window frames. Thermal performance increasing measures, surface modeling, and frame cavity modeling are among the topics discussed. The review shows that the current knowledge gives the basis for improving the calculation procedures in the calculation standards. At the same time it is room for improvement within some areas, e.g. to fully understand the natural convection effects inside irregular vertical frame cavities (jambs) and ventilated frame cavities.« less

Night-time naturally ventilated offices: Statistical simulations of window-use patterns from field monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yun, Geun Young; Steemers, Koen

2010-07-15

This paper investigates occupant behaviour of window-use in night-time naturally ventilated offices on the basis of a pilot field study, conducted during the summers of 2006 and 2007 in Cambridge, UK, and then demonstrates the effects of employing night-time ventilation on indoor thermal conditions using predictive models of occupant window-use. A longitudinal field study shows that occupants make good use of night-time natural ventilation strategies when provided with openings that allow secure ventilation, and that there is a noticeable time of day effect in window-use patterns (i.e. increased probability of action on arrival and departure). We develop logistic models ofmore » window-use for night-time naturally ventilated offices, which are subsequently applied to a behaviour algorithm, including Markov chains and Monte Carlo methods. The simulations using the behaviour algorithm demonstrate a good agreement with the observational data of window-use, and reveal how building design and occupant behaviour collectively affect the thermal performance of offices. They illustrate that the provision of secure ventilation leads to more frequent use of the window, and thus contributes significantly to the achievement of a comfortable indoor environment during the daytime occupied period. For example, the maximum temperature for a night-time ventilated office is found to be 3 C below the predicted value for a daytime-only ventilated office. (author)« less

Radiation heat transfer simulation in a window for a small particle solar receiver using the Monte Carlo method

NASA Astrophysics Data System (ADS)

Whitmore, Alexander Jason

Concentrating solar power systems are currently the predominant solar power technology for generating electricity at the utility scale. The central receiver system, which is a concentrating solar power system, uses a field of mirrors to concentrate solar radiation onto a receiver where a working fluid is heated to drive a turbine. Current central receiver systems operate on a Rankine cycle, which has a large demand for cooling water. This demand for water presents a challenge for the current central receiver systems as the ideal locations for solar power plants have arid climates. An alternative to the current receiver technology is the small particle receiver. The small particle receiver has the potential to produce working fluid temperatures suitable for use in a Brayton cycle which can be more efficient when pressurized to 0.5 MPa. Using a fused quartz window allows solar energy into the receiver while maintaining a pressurized small particle receiver. In this thesis, a detailed numerical investigation for a spectral, three dimensional, cylindrical glass window for a small particle receiver was performed. The window is 1.7 meters in diameter and 0.0254 meters thick. There are three Monte Carlo Ray Trace codes used within this research. The first MCRT code, MIRVAL, was developed by Sandia National Laboratory and modified by a fellow San Diego State University colleague Murat Mecit. This code produces the solar rays on the exterior surface of the window. The second MCRT code was developed by Steve Ruther and Pablo Del Campo. This code models the small particle receiver, which creates the infrared spectral direction flux on the interior surface of the window used in this work. The third MCRT, developed for this work, is used to model radiation heat transfer within the window itself and is coupled to an energy equation solver to produce a temperature distribution. The MCRT program provides a source term to the energy equation. This in turn, produces a new temperature field for the MCRT program; together the equations are solved iteratively. These iterations repeat until convergence is reached for a steady state temperature field. The energy equation was solved using a finite volume method. The window's thermal conductivity is modeled as a function of temperature. This thermal model is used to investigate the effects of different materials, receiver geometries, interior convection coefficients and exterior convection coefficients. To prevent devitrification and the ultimate failure of the window, the window needs to stay below the devitrification temperature of the material. In addition, the temperature gradients within the window need to be kept to a minimum to prevent thermal stresses. A San Diego State University colleague E-Fann Saung uses these temperature maps to insure that the mounting of the window does not produce thermal stresses which can cause cracking in the brittle fused quartz. The simulations in this thesis show that window temperatures are below the devitrification temperature of the window when there are cooling jets on both surfaces of the window. Natural convection on the exterior window surface was explored and it does not provide adequate cooling; therefore forced convection is required. Due to the low thermal conductivity of the window, the edge mounting thermal boundary condition has little effect on the maximum temperature of the window. The simulations also showed that the solar input flux absorbed less than 1% of the incoming radiation while the window absorbed closer to 20% of the infrared radiation emitted by the receiver. The main source of absorbed power in the window is located directly on the interior surface of the window where the infrared radiation is absorbed. The geometry of the receiver has a large impact on the amount of emitted power which reached the interior surface of the window, and using a conical shaped receiver dramatically reduced the receiver's infrared flux on the window. The importance of internal emission is explored within this research. Internal emission produces a more even emission field throughout the receiver than applying radiation surface emission only. Due to a majority of the infrared receiver re-radiation being absorbed right at the interior surface, the surface emission only approximation method produces lower maximum temperatures.

Thermal performance demonstration of a prototype internally cooled nose tip/forebody/window assembly

NASA Astrophysics Data System (ADS)

Wojciechowski, Carl J.; Brooks, Lori C.; Teal, Gene; Karu, Zain; Kalin, David A.; Jones, Gregory W.; Romero, Harold

1996-11-01

Internally liquid cooled apertures (windows) installed in a full size forebody have been characterized under high heat flux conditions representative of endoatmospheric flight. Analysis and test data obtained in the laboratory and at arc heater test facilities at Arnold Engineering Development Center and NASA Ames are presented in this paper. Data for several types of laboratory bench tests are presented: transmission interferometry and imaging, coolant pressurization effects on optical quality, and coolant flow rate calibrations for both the window and other internally cooled components. Initially, using heat transfer calibration models identical in shape to the flight test articles, arc heater facility thermal test environments were obtained at several conditions representative of full flight thermal environments. Subsequent runs tested the full-up flight article including nosetip, forebody and aperture for full flight duplication of surface heating rates and exposure ties. Pretest analyses compared will to test measurements. These data demonstrate a very efficient internal liquid cooling design which can be applied to other applications such as cooled mirrors for high heat flux applications.

High performance sapphire windows

NASA Technical Reports Server (NTRS)

Bates, Stephen C.; Liou, Larry

1993-01-01

High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire.

High performance sapphire windows

NASA Astrophysics Data System (ADS)

Bates, Stephen C.; Liou, Larry

1993-02-01

High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire.

Determination of Thermal Transmittance of Insulated Double Low-E Glazing Panel Using Portable Uglass Measuring Technique

NASA Astrophysics Data System (ADS)

Kim, Inkoo; Frenzl, Alexander; Kim, Taehan; Min, Steven; Blumm, Jürgen

2018-01-01

Windows are regarded as the primary object of energy efficiency in buildings because window is one of the major energy loss areas in building construction. Existing methods were not field measurements and were not enough to get the correct thermal transmittance. We used portable Ug measuring device on field and measured the thermal transmittance with low-E coated and uncoated double glazing panels in existing houses, apartments and buildings. In addition, we prepared four test benches and compared the insulation performance according to the construction conditions. In results, the insulation performance of double glazing panel with low-E coating is up to about 41 % higher than uncoated panel due to low-E coating inside and the glazing panel filled with about 90 % of argon gas decrease about 0.15 W \\cdot m^{-2} \\cdot K^{-1} than glazing panel filled with air gas. The measured results were compared with the theoretically calculated results according to DIN EN 673 to confirm the reliability of the analytical results. In this study, portable NETZSCH Uglass is used to increase the accuracy of calculation of thermal transmittance with various double and triple glazing panels. The paper analyzes the insulation performance of the double glazing panels in accordance with the construction conditions.

Active two-phase cooling of an IR window for a hypersonic interceptor

NASA Astrophysics Data System (ADS)

Burzlaff, B. H.; Chivian, Jay S.; Cotten, W. D.; Hemphill, R. B.; Huhlein, Michael A.

1993-06-01

A novel actively cooled window for an IR sensor on a hypersonic interceptor is envisioned which achieves an IR window with high transmittance, low emittance, and low image distortion under high aerodynamic heat flux. The cooling concept employs two-phase convective boiling of liquid ammonia. Coolant is confined to narrow, parallel channels within the window to minimize obscuration of the aperture. The high latent heat of vaporization of ammonia minimizes coolant mass-flow requirements. Low boiling temperatures at projected operating pressures promote high thermal conductivity and low emissivity in the window. The concept was tested with thermal measurements on sub-mm width coolant channels in Si. High values for heat transfer coefficient and critical heat flux were obtained. Thermal gradients within the window can be controlled by the coolant channel configuration. Design options are investigated by predicting the effect of aerodynamic heat flux on the image produced by an IR sensor with a cooled window. Ammonia-cooled IR windows will function in the anticipated aerothermal environment.

Smart window using a thermally and optically switchable liquid crystal cell

NASA Astrophysics Data System (ADS)

Oh, Seung-Won; Kim, Sang-Hyeok; Baek, Jong-Min; Yoon, Tae-Hoon

2018-02-01

Light shutter technologies that can control optical transparency have been studied extensively for developing curtain-free smart windows. We introduce thermally and optically switchable light shutters using LCs doped with push-pull azobenzene, which is known to speed up thermal relaxation. The liquid crystal light shutter can be switched between translucent and transparent states or transparent and opaque states by phase transition through changing temperature or photo-isomerization of doped azobenzene. The liquid crystal light shutter can be used for privacy windows with an initial translucent state or energy-saving windows with an initial transparent state.

Thermoelastic Analysis of Hyper-X Camera Windows Suddenly Exposed to Mach 7 Stagnation Aerothermal Shock

NASA Technical Reports Server (NTRS)

Ko, William L.; Gong, Leslie

2000-01-01

To visually record the initial free flight event of the Hyper-X research flight vehicle immediately after separation from the Pegasus(registered) booster rocket, a video camera was mounted on the bulkhead of the adapter through which Hyper-X rides on Pegasus. The video camera was shielded by a protecting camera window made of heat-resistant quartz material. When Hyper-X separates from Pegasus, this camera window will be suddenly exposed to Mach 7 stagnation thermal shock and dynamic pressure loading (aerothermal loading). To examine the structural integrity, thermoelastic analysis was performed, and the stress distributions in the camera windows were calculated. The critical stress point where the tensile stress reaches a maximum value for each camera window was identified, and the maximum tensile stress level at that critical point was found to be considerably lower than the tensile failure stress of the camera window material.

Experimental validation and model development for thermal transmittances of porous window screens and horizontal louvred blind systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, Robert; Goudey, Howdy; Curcija, D. Charlie

Virtually every home in the US has some form of shades, blinds, drapes, or other window attachment, but few have been designed for energy savings. In order to provide a common basis of comparison for thermal performance it is important to have validated simulation tools. This study outlines a review and validation of the ISO 15099 centre-of-glass thermal transmittance correlations for naturally ventilated cavities through measurement and detailed simulations. The focus is on the impacts of room-side ventilated cavities, such as those found with solar screens and horizontal louvred blinds. The thermal transmittance of these systems is measured experimentally, simulatedmore » using computational fluid dynamics analysis, and simulated utilizing simplified correlations from ISO 15099. Finally, correlation coefficients are proposed for the ISO 15099 algorithm that reduces the mean error between measured and simulated heat flux for typical solar screens from 16% to 3.5% and from 13% to 1% for horizontal blinds.« less

Experimental validation and model development for thermal transmittances of porous window screens and horizontal louvred blind systems

DOE PAGES

Hart, Robert; Goudey, Howdy; Curcija, D. Charlie

2017-05-16

Virtually every home in the US has some form of shades, blinds, drapes, or other window attachment, but few have been designed for energy savings. In order to provide a common basis of comparison for thermal performance it is important to have validated simulation tools. This study outlines a review and validation of the ISO 15099 centre-of-glass thermal transmittance correlations for naturally ventilated cavities through measurement and detailed simulations. The focus is on the impacts of room-side ventilated cavities, such as those found with solar screens and horizontal louvred blinds. The thermal transmittance of these systems is measured experimentally, simulatedmore » using computational fluid dynamics analysis, and simulated utilizing simplified correlations from ISO 15099. Finally, correlation coefficients are proposed for the ISO 15099 algorithm that reduces the mean error between measured and simulated heat flux for typical solar screens from 16% to 3.5% and from 13% to 1% for horizontal blinds.« less

Arcjet exploratory tests of ARC optical window design for the AFE vehicle

NASA Technical Reports Server (NTRS)

Whiting, Ellis E.; Terrazas-Salinas, Imelda; Craig, Roger A.; Sobeck, Charles K.; Sarver, George L., III; Salerno, Louis J.; Love, Wendell; Maa, Scott; Covington, AL

1991-01-01

Tests were made in the 20 MW arc jet facility at the NASA ARC to determine the suitability of sapphire and fused silica as window materials for the Aeroassist Flight Experiment (AFE) entry vehicle. Twenty nine tests were made; 25 at a heating rate about 80 percent of that expected during the AFE entry and 4 at approximately the full, 100 percent AFE heating rate profile, that produces a temperature of about 2900 F on the surface of the tiles that protect the vehicle. These tests show that a conductively cooled window design using mechanical thermal contacts and sapphire is probably not practical. Cooling the window using mechanical thermal contacts produces thermal stresses in the sapphire that cause the window to crack. An insulated design using sapphire, that cools the window as little as possible, appears promising although some spectral data in the vacuum-ultra-violet (VUV) will be lost due to the high temperature reached by the sapphire. The surface of the insulated sapphire windows, tested at the 100 percent AFE heating rate, showed some slight ablation, and cracks appeared in two of three test windows. One small group of cracks were obviously caused by mechanical binding of the window in the assembly, which can be eliminated with improved design. Other cracks were long, straight, thin crystallographic cracks that have very little effect on the optical transmission of the window. Also, the windows did not fall apart along these crystallographic cracks when the windows were removed from their assemblies. Theoretical results from the thermal analysis computer program SINDA indicate that increasing the window thickness from 4 to 8 mm may enable surface ablation to be avoided. An insulated design using a fused silica window tested at the nominal AFE heating rate experienced severe ablation, thus fused silica is not considered to be an acceptable window material.

Rain Erosion Resistant AR Coating for ZnS Windows

DTIC Science & Technology

1980-05-10

number) FLUR Windows, Rain Erosion Coatings; High Performance Aircrait in’- Coa t f ng De 1)os I t L on Tv c I n I (Iu es ; Me t ro Io gy ; TLest, i11g...developed for jinaging el"(rtrlo opt ical sensor systems intended for use on high performance a irer; Ia It s, ’ as F-4, F-15, F-16, A-10 J-18 and F-ill...for Forward Looking Infrared (FLIk) thermal imaging sensors such as those in- corporated in the PAVE TACK pod and the IR Maverick Missile. ’This

Numerical and experimental validation for the thermal transmittance of windows with cellular shades

DOE PAGES

Hart, Robert

2018-02-21

Some highly energy efficient window attachment products are available today, but more rapid market adoption would be facilitated by fair performance metrics. It is important to have validated simulation tools to provide a basis for this analysis. This paper outlines a review and validation of the ISO 15099 center-of-glass zero-solar-load heat transfer correlations for windows with cellular shades. Thermal transmittance was measured experimentally, simulated using computational fluid dynamics (CFD) analysis, and simulated utilizing correlations from ISO 15099 as implemented in Berkeley Lab WINDOW and THERM software. CFD analysis showed ISO 15099 underestimates heat flux of rectangular cavities by up tomore » 60% when aspect ratio (AR) = 1 and overestimates heat flux up to 20% when AR = 0.5. CFD analysis also showed that wave-type surfaces of cellular shades have less than 2% impact on heat flux through the cavities and less than 5% for natural convection of room-side surface. WINDOW was shown to accurately represent heat flux of the measured configurations to a mean relative error of 0.5% and standard deviation of 3.8%. Finally, several shade parameters showed significant influence on correlation accuracy, including distance between shade and glass, inconsistency in cell stretch, size of perimeter gaps, and the mounting hardware.« less

Numerical and experimental validation for the thermal transmittance of windows with cellular shades

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, Robert

Some highly energy efficient window attachment products are available today, but more rapid market adoption would be facilitated by fair performance metrics. It is important to have validated simulation tools to provide a basis for this analysis. This paper outlines a review and validation of the ISO 15099 center-of-glass zero-solar-load heat transfer correlations for windows with cellular shades. Thermal transmittance was measured experimentally, simulated using computational fluid dynamics (CFD) analysis, and simulated utilizing correlations from ISO 15099 as implemented in Berkeley Lab WINDOW and THERM software. CFD analysis showed ISO 15099 underestimates heat flux of rectangular cavities by up tomore » 60% when aspect ratio (AR) = 1 and overestimates heat flux up to 20% when AR = 0.5. CFD analysis also showed that wave-type surfaces of cellular shades have less than 2% impact on heat flux through the cavities and less than 5% for natural convection of room-side surface. WINDOW was shown to accurately represent heat flux of the measured configurations to a mean relative error of 0.5% and standard deviation of 3.8%. Finally, several shade parameters showed significant influence on correlation accuracy, including distance between shade and glass, inconsistency in cell stretch, size of perimeter gaps, and the mounting hardware.« less

High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baechler, M.; Gilbride, T.; Ruiz, K.

This document is the sixth volume of the Building America Best Practices Series. It presents information that is useful throughout the United States for enhancing the energy efficiency practices in the specific climate zones that are presented in the first five Best Practices volumes. It provides an introduction to current photovoltaic and solar thermal building practices. Information about window selection and shading is included.

Window Frame Types | Efficient Windows Collaborative

Science.gov Websites

metal frames. Metal Frames Metal Frame with Thermal Break Non-metal Frames Non-metal There is a variety of non-metal framing materials for windows including, wood, wood with metal/vinyl cladding, vinyl disadvantages. Non-metal Frames Non-metal Frame, Thermally Improved Does frame material type matter? The

Conjugate Heat Transfer and Thermal Mechanical Analysis for Liquid Metal Targets for High Power Electron Beams.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olivas, Eric Richard

2016-02-26

A conjugate heat transfer and thermal structural analysis was completed, with the objective of determining the following: Lead bismuth eutectic (LBE) peak temperature, free convective velocity patterns in the LBE, peak beam window temperature, and thermal stress/deformation in the window.

Advanced Antireflection Coatings for High-Performance Solar Energy Applications

NASA Technical Reports Server (NTRS)

Pan, Noren

2015-01-01

Phase II objectives: Develop and refine antireflection coatings incorporating lanthanum titanate as an intermediate refractive index material; Investigate wet/dry thermal oxidation of aluminum containing semiconductor compounds as a means of forming a more transparent window layer with equal or better optical properties than its unoxidized form; Develop a fabrication process that allows integration of the oxidized window layer and maintains the necessary electrical properties for contacting the solar cell; Conduct an experimental demonstration of the best candidates for improved antireflection coatings.

Design of energy efficient building with radiant slab cooling

NASA Astrophysics Data System (ADS)

Tian, Zhen

2007-12-01

Air-conditioning comprises a substantial fraction of commercial building energy use because of compressor-driven refrigeration and fan-driven air circulation. Core regions of large buildings require year-round cooling due to heat gains from people, lights and equipment. Negative environmental impacts include CO2 emissions from electric generation and leakage of ozone-depleting refrigerants. Some argue that radiant cooling simultaneously improves building efficiency and occupant thermal comfort, and that current thermal comfort models fail to reflect occupant experience with radiant thermal control systems. There is little field evidence to test these claims. The University of Calgary's Information and Communications Technology (ICT) Building, is a pioneering radiant slab cooling installation in North America. Thermal comfort and energy performance were evaluated. Measurements included: (1) heating and cooling energy use, (2) electrical energy use for lighting and equipment, and (3) indoor temperatures. Accuracy of a whole building energy simulation model was evaluated with these data. Simulation was then used to compare the radiant slab design with a conventional (variable air volume) system. The radiant system energy performance was found to be poorer mainly due to: (1) simultaneous cooling by the slab and heating by other systems, (2) omission of low-exergy (e.g., groundwater) cooling possible with the high cooling water temperatures possible with radiant slabs and (3) excessive solar gain and conductive heat loss due to the wall and fenestration design. Occupant thermal comfort was evaluated through questionnaires and concurrent measurement of workstation comfort parameters. Analysis of 116 sets of data from 82 occupants showed that occupant assessment was consistent with estimates based on current thermal comfort models. The main thermal comfort improvements were reductions in (1) local discomfort from draft and (2) vertical air temperature stratification. The analysis showed that integrated architectural and mechanical design is required to achieve the potential benefits of radiant slab cooling, including: (1) reduction of peak solar gain via windows through (a) avoiding large window-to-wall ratios and/or (b) exterior shading of windows, (2) use of low-quality cooling sources such as cooling towers and ground water, especially in cold, dry climates, and (3) coordination of system control to avoid simultaneous heating and cooling.

3D PRINTING SUSTAINABLE BUILDING COMPONENTS FOR FACADES AND AS WINDOW ELEMENTS

EPA Science Inventory

The façade elements we design will be targeted at the construction industry and will be evaluated in the context of rapid manufacturing, energy conservation, thermal performance, structural strength, durability and construction assembly. The façade element des...

Stimulation research on the measurement of the IRW pneumatic thermal radiation

NASA Astrophysics Data System (ADS)

Wei, Yifang; Liu, Xiaohua; Liu, Ming; Dong, Liquan; Zhao, Yuejin

2018-01-01

When an aircraft flies at a hypersonic speed within the atmosphere, the temperature of the infrared window (IRW) on the aircraft will rise rapidly due to the high-speed incoming flow will produce a severe aerodynamic heating to its optical detection window. The infrared (IR) radiation of the high-temperature gas and optical window will generate severe pneumatic thermal radiation effect upon the detection system, with the performance of the IR detector possibly being reduced or even destroyed. To evaluate the influence on the target imaging made by the IRW radiation, the experiment on the basis of building a simulating model is conducted by the means of ray tracing so that the accurate transmittance of the IRW can be observed under the different temperature. And then the radiation distribution of the thermal radiation on the detector generated by the IRW radiation noise and target signal can finally be obtained. This paper also records the different parameters in the detection system being set in the experiment, and analyzes the different influences brought by various factors to the Signal to Noise Ratio (SNR). It is also expected that it will provide a data reference to the following research of radiation noise suppression and design of IR detection system.

Improved Ohmic-contact to AlGaN/GaN using Ohmic region recesses by self-terminating thermal oxidation assisted wet etching technique

NASA Astrophysics Data System (ADS)

Liu, J.; Wang, J.; Wang, H.; Zhu, L.; Wu, W.

2017-06-01

Lower Ti/Al/Ni/Au Ohmic contact resistance on AlGaN/GaN with wider rapid thermal annealing (RTA) temperature window was achieved using recessed Ohmic contact structure based on self-terminating thermal oxidation assisted wet etching technique (STOAWET), in comparison with conventional Ohmic contacts. Even at lower temperature such as 650°C, recessed structure by STOAWET could still obtain Ohmic contact with contact resistance of 1.97Ω·mm, while conventional Ohmic structure mainly featured as Schottky contact. Actually, both Ohmic contact recess and mesa isolation processes could be accomplished by STOAWET in one process step and the process window of STOAWET is wide, simplifying AlGaN/GaN HEMT device process. Our experiment shows that the isolation leakage current by STOAWET is about one order of magnitude lower than that by inductivity coupled plasma (ICP) performed on the same wafer.

Using of Aerogel to Improve Thermal Insulating Properties of Windows

NASA Astrophysics Data System (ADS)

Valachova, Denisa; Zdrazilova, Nada; Panovec, Vladan; Skotnicova, Iveta

2018-06-01

For the best possible thermal-technical properties of building structures it is necessary to use materials with very low thermal conductivity. Due to the increasing thermal-technical requirements for building structures, the insulating materials are developed. One of the modern thermal insulating materials is so-called aerogel. Unfortunately, this material is not used in the field of external thermal insulation composite systems because of its price and its properties. The aim of this paper is to present possibilities of using this insulating material in the civil engineering - specifically a usage of aerogel in the production of windows.

Investigation of high temperature antennas for space shuttle

NASA Technical Reports Server (NTRS)

Kuhlman, E. A.

1973-01-01

The design and development of high temperature antennas for the space shuttle orbiter are discussed. The antenna designs were based on three antenna types, an annular slot (L-Band), a linear slot (C-Band), and a horn (C-Band). The design approach was based on combining an RF window, which provides thermal protection, with an off-the-shelf antenna. Available antenna window materials were reviewed and compared, and the materials most compatible with the design requirements were selected. Two antenna window design approaches were considered: one employed a high temperature dielectric material and a low density insulation material, and the other an insulation material usable for the orbiter thermal protection system. Preliminary designs were formulated and integrated into the orbiter structure. Simple electrical models, with a series of window configurations, were constructed and tested. The results of tests and analyses for the final antenna system designs are given and show that high temperature antenna systems consisting of off-the-shelf antennas thermally protected by RF windows can be designed for the Space Shuttle Orbiter.

High temperature solar receiver

NASA Technical Reports Server (NTRS)

1981-01-01

The development of a high temperature solar thermal receiver is described. A prototype receiver and associated test support (auxiliary) hardware was fabricated. Shakedown and initial performance tests of the prototype receiver were performed. Maximum outlet temperatures of 1600 F were achieved at 100% solar (70-75 kW) input power with 900 F inlet temperatures and a subsequent testing was concluded by a 2550 F outlet run. The window retaining assembly was modified to improve its tolerance for thermal distortion of the flanges. It is shown that cost effective receiver designs can be implemented within the framework of present materials technology.

Apparatus for insulating windows and the like

DOEpatents

Mitchell, R.A.

1984-06-19

Apparatus for insulating window openings through walls and the like includes a thermal shutter, a rail for mounting the shutter adjacent to the window opening and a coupling for connecting the shutter to the rail. The thermal shutter includes an insulated panel adhered to frame members which surround the periphery of the panel. The frame members include a hard portion for providing the frame and a soft portion for providing a seal with that portion of the wall adjacent to the periphery of the opening. The coupling means is preferably integral with the attachment rail. According to a preferred embodiment, the coupling means includes a continuous hinge of reduced thickness. The thermal shutter can be permanently attached, hinged, bi-folded, or sliding with respect to the window and wall. A distribution method is to market the apparatus in kit'' form. 11 figs.

Apparatus for insulating windows and the like

DOEpatents

Mitchell, Robert A.

1984-01-01

Apparatus for insulating window openings through walls and the like includes a thermal shutter, a rail for mounting the shutter adjacent to the window opening and a coupling for connecting the shutter to the rail. The thermal shutter includes an insulated panel adhered to frame members which surround the periphery of the panel. The frame members include a hard portion for providing the frame and a soft portion for providing a seal with that portion of the wall adjacent to the periphery of the opening. The coupling means is preferably integral with the attachment rail. According to a preferred embodiment, the coupling means includes a continuous hinge of reduced thickness. The thermal shutter can be permanently attached, hinged, bi-folded, or sliding with respect to the window and wall. A distribution method is to market the apparatus in "kit" form.

Dynamic study for performance improvements of a thermo-mechanically bistable heat engine

NASA Astrophysics Data System (ADS)

Boughaleb, J.; Arnaud, A.; Monfray, S.; Cottinet, P. J.; Quenard, S.; Pitone, G.; Boeuf, F.; Guyomar, D.; Skotnicki, T.

2015-12-01

This paper focuses on a thermal study of a thermal energy harvester based on the coupling of a bimetallic strip heat engine with a piezoelectric membrane for wasted heat scavenging. Such a harvester is dedicated to power autonomous systems such as wireless sensor nodes. For a better understanding of the working principle of the system, it is compulsory to have a good understanding of the thermal specificities and phenomenon taking place inside the harvester. Attention is consequently focused on the thermal modeling of the harvester in static mode using the equivalence between the electrical and thermal quantities. This first modeling step allowed the improvement of the thermal properties inside the system by increasing the thermal gradient across it. However, the bimetal being the active part of the system has not been taken into account in this model and shadow zones persisted regarding the bimetal operation windows as a function of its snapping temperatures and hysteresis. To overcome this, a dynamic model is proposed in this paper taking into account the bimetal as a switched capacitance alternatively in contact with the hot source and the cold surface. This last model completed the static one by predicting the bimetal's operation windows in function of its intrinsic properties and the operation range evolution in function of the snapping temperature first and then in function of the bimetal thermal hysteresis. Moreover, experimental measurements enable to validate the proposed model and to point out the most powerful bimetals for scavenging higher amounts of power.

On the relationship between human search strategies, conspicuity, and search performance

NASA Astrophysics Data System (ADS)

Hogervorst, Maarten A.; Bijl, Piet; Toet, Alexander

2005-05-01

We determined the relationship between search performance with a limited field of view (FOV) and several scanning- and scene parameters in human observer experiments. The observers (38 trained army scouts) searched through a large search sector for a target (a camouflaged person) on a heath. From trial to trial the target appeared at a different location. With a joystick the observers scanned through a panoramic image (displayed on a PC-monitor) while the scan path was registered. Four conditions were run differing in sensor type (visual or thermal infrared) and window size (large or small). In conditions with a small window size the zoom option could be used. Detection performance was highly dependent on zoom factor and deteriorated when scan speed increased beyond a threshold value. Moreover, the distribution of scan speeds scales with the threshold speed. This indicates that the observers are aware of their limitations and choose a (near) optimal search strategy. We found no correlation between the fraction of detected targets and overall search time for the individual observers, indicating that both are independent measures of individual search performance. Search performance (fraction detected, total search time, time in view for detection) was found to be strongly related to target conspicuity. Moreover, we found the same relationship between search performance and conspicuity for visual and thermal targets. This indicates that search performance can be predicted directly by conspicuity regardless of the sensor type.

Some selected quantitative methods of thermal image analysis in Matlab.

PubMed

Koprowski, Robert

2016-05-01

The paper presents a new algorithm based on some selected automatic quantitative methods for analysing thermal images. It shows the practical implementation of these image analysis methods in Matlab. It enables to perform fully automated and reproducible measurements of selected parameters in thermal images. The paper also shows two examples of the use of the proposed image analysis methods for the area of ​​the skin of a human foot and face. The full source code of the developed application is also provided as an attachment. The main window of the program during dynamic analysis of the foot thermal image. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thermal regulation for APDs in a 1 mm(3) resolution clinical PET camera: design, simulation and experimental verification.

PubMed

Zhai, Jinjian; Vandenbroucke, Arne; Levin, Craig S

2014-07-21

We are developing a 1 mm(3) resolution positron emission tomography camera dedicated to breast imaging. The camera collects high energy photons emitted from radioactively labeled agents introduced in the patients in order to detect molecular signatures of breast cancer. The camera comprises many layers of lutetium yttrium oxyorthosilicate (LYSO) scintillation crystals coupled to position sensitive avalanche photodiodes (PSAPDs). The main objectives of the studies presented in this paper are to investigate the temperature profile of the layers of LYSO-PSAPD detectors (a.k.a. 'fins') residing in the camera and to use these results to present the design of the thermal regulation system for the front end of the camera. The study was performed using both experimental methods and simulation. We investigated a design with a heat-dissipating fin. Three fin configurations are tested: fin with Al windows (FwW), fin without Al windows (FwoW) and fin with alumina windows (FwAW). A Fluent® simulation was conducted to study the experimentally inaccessible temperature of the PSAPDs. For the best configuration (FwW), the temperature difference from the center to a point near the edge is 1.0 K when 1.5 A current was applied to the Peltier elements. Those of FwoW and FwAW are 2.6 K and 1.7 K, respectively. We conclude that the design of a heat-dissipating fin configuration with 'aluminum windows' (FwW) that borders the scintillation crystal arrays of 16 adjacent detector modules has better heat dissipation capabilities than the design without 'aluminum windows' (FwoW) and the design with 'alumina windows' (FwAW), respectively.

Passivhaus: indoor comfort and energy dynamic analysis.

NASA Astrophysics Data System (ADS)

Guida, Antonella; Pagliuca, Antonello; Cardinale, Nicola; Rospi, Gianluca

2013-04-01

The research aims to verify the energy performance as well as the indoor comfort of an energy class A+ building, built so that the sum of the heat passive contributions of solar radiation, transmitted through the windows, and the heat generated inside the building, are adeguate to compensate for the envelope loss during the cold season. The building, located in Emilia Romagna (Italy), was built using a wooden structure, an envelope realized using a pinewood sandwich panels (transmittance U = 0.250 W/m2K) and, inside, a wool flax insulation layer and thermal window frame with low-emissivity glass (U = 0524 W/m2K). The building design and construction process has followed the guidelines set by "CasaClima". The building has been modeled in the code of dynamic calculation "Energy Plus" by the Design Builder application and divided it into homogenous thermal zones, characterized by winter indoor temperature set at 20 ° (+ / - 1 °) and summer indoor temperature set at 26 ° (+ / - 1 °). It has modeled: the envelope, as described above, the "free" heat contributions, the air conditioning system, the Mechanical Ventilation system as well as home automation solutions. The air conditioning system is an heat pump, able to guarantee an optimization of energy consumption (in fact, it uses the "free" heat offered by the external environment for conditioning indoor environment). As regards the air recirculation system, it has been used a mechanical ventilation system with internal heat cross-flow exchanger, with an efficiency equal to 50%. The domotic solutions, instead, regard a system for the control of windows external screening using reeds, adjustable as a function of incident solar radiation and a lighting management system adjusted automatically using a dimmer. A so realized building meets the requirement imposed from Italian standard UNI/TS 11300 1, UNI/TS 11300 2 and UNI/TS 11300 3. The analysis was performed according to two different configurations: in "spontaneous-state analysis" (that provides the only energy performance of the structure) and considering the "building-equipments" as a system (which provides the overall performance of the "building system"). The first analysis shows as the absence of thermal mass and the envelope super-heating prevent to incoming heat to exit, overheating the indoor environment. The analysis of the overall performance of the "building system" highlights, instead, as the thermal load is much greater during the summer than in winter; this means that, using a low inertia envelopes, the energy saved in the winter can be used to satisfy the thermal performance in the summer. This is further demonstrated by comparing the performance of indoor temperatures and the relative energy consumption of a similar building with greater thermal inertia. Further analysis involved a critical comparison between the "semisteady-state analysis" ("CasaClima" methodology) and the analysis in dynamic conditions (using "Energy Plus" software).

Thermal effects in Cs DPAL and alkali cell window damage

NASA Astrophysics Data System (ADS)

Zhdanov, B. V.; Rotondaro, M. D.; Shaffer, M. K.; Knize, R. J.

2016-10-01

Experiments on power scaling of Diode Pumped Alkali Lasers (DPALs) revealed some limiting parasitic effects such as alkali cell windows and gain medium contamination and damage, output power degradation in time and others causing lasing efficiency decrease or even stop lasing1 . These problems can be connected with thermal effects, ionization, chemical interactions between the gain medium components and alkali cells materials. Study of all these and, possibly, other limiting effects and ways to mitigate them is very important for high power DPAL development. In this talk we present results of our experiments on temperature measurements in the gain medium of operating Cs DPAL at different pump power levels in the range from lasing threshold to the levels causing damage of the alkali cell windows. For precise contactless in situ temperature measurements, we used an interferometric technique, developed in our lab2 . In these experiments we demonstrated that damage of the lasing alkali cell starts in the bulk with thermal breakdown of the hydrocarbon buffer gas. The degradation processes start at definite critical temperatures of the gain medium, different for each mixture of buffer gas. At this critical temperature, the hydrocarbon and the excited alkali metal begin to react producing the characteristic black soot and, possibly, some other chemical compounds, which both harm the laser performance and significantly increase the harmful heat deposition within the laser medium. This soot, being highly absorptive, is catastrophically heated to very high temperatures that visually observed as bulk burning. This process quickly spreads to the cell windows and causes their damage. As a result, the whole cell is also contaminated with products of chemical reactions.

Facile fabrication of multilayer separators for lithium-ion battery via multilayer coextrusion and thermal induced phase separation

NASA Astrophysics Data System (ADS)

Li, Yajie; Pu, Hongting

2018-04-01

Polypropylene (PP)/polyethylene (PE) multilayer separators with cellular-like submicron pore structure for lithium-ion battery are efficiently fabricated by the combination of multilayer coextrusion (MC) and thermal induced phase separation (TIPS). The as-prepared separators, referred to as MC-TIPS PP/PE, not only show efficacious thermal shutdown function and wider shutdown temperature window, but also exhibit higher thermal stability than the commercial separator with trilayer construction of PP and PE (Celgard® 2325). The dimensional shrinkage of MC-TIPS PP/PE can be negligible until 160 °C. In addition, compared to the commercial separator, MC-TIPS PP/PE exhibits higher porosity and electrolyte uptake, leading to higher ionic conductivity and better battery performances. The above-mentioned fascinating characteristics with the convenient preparation process make MC-TIPS PP/PE a promising candidate for the application as high performance lithium-ion battery separators.

Ultrathin Fluidic Laminates for Large‐Area Façade Integration and Smart Windows

PubMed Central

Heiz, Benjamin P. V.; Pan, Zhiwen; Lautenschläger, Gerhard; Sirtl, Christin; Kraus, Matthias

2016-01-01

Buildings represent more than 40% of Europe's energy demands and about one third of its CO2 emissions. Energy efficient buildings and, in particular, building skins have therefore been among the key priorities of international research agendas. Here, glass–glass fluidic devices are presented for large‐area integration with adaptive façades and smart windows. These devices enable harnessing and dedicated control of various liquids for added functionality in the building envelope. Combining a microstructured glass pane, a thin cover sheet with tailored mechanical performance, and a liquid for heat storage and transport, a flat‐panel laminate is generated with thickness adapted to a single glass sheet in conventional windows. Such multimaterial devices can be integrated with state‐of‐the‐art window glazings or façades to harvest and distribute thermal as well as solar energy by wrapping buildings into a fluidic layer. High visual transparency is achieved through adjusting the optical properties of the employed liquid. Also secondary functionality, such as chromatic windows, polychromatism, or adaptive energy uptake can be generated on part of the liquid. PMID:28331790

Ultrathin Fluidic Laminates for Large-Area Façade Integration and Smart Windows.

PubMed

Heiz, Benjamin P V; Pan, Zhiwen; Lautenschläger, Gerhard; Sirtl, Christin; Kraus, Matthias; Wondraczek, Lothar

2017-03-01

Buildings represent more than 40% of Europe's energy demands and about one third of its CO 2 emissions. Energy efficient buildings and, in particular, building skins have therefore been among the key priorities of international research agendas. Here, glass-glass fluidic devices are presented for large-area integration with adaptive façades and smart windows. These devices enable harnessing and dedicated control of various liquids for added functionality in the building envelope. Combining a microstructured glass pane, a thin cover sheet with tailored mechanical performance, and a liquid for heat storage and transport, a flat-panel laminate is generated with thickness adapted to a single glass sheet in conventional windows. Such multimaterial devices can be integrated with state-of-the-art window glazings or façades to harvest and distribute thermal as well as solar energy by wrapping buildings into a fluidic layer. High visual transparency is achieved through adjusting the optical properties of the employed liquid. Also secondary functionality, such as chromatic windows, polychromatism, or adaptive energy uptake can be generated on part of the liquid.

3rd Generation Thermal Imager Sensor Performance

DTIC Science & Technology

2006-11-01

suffers in the day compared to the night. This degradation is related to high levels of daytime clutter caused by solar reflections and loading and...1 2 3 4 5 LWIR σT (K) M W IR σ T (K ) MWIR = LWIR White Building Block Door Road Roof Shingle Window Rural Backgrounds: MWIR σT vs LWIR σT

Investigation of a large power water-cooled microwave resonance window for application with the ECR ion source

NASA Astrophysics Data System (ADS)

Guo, Guo; Guo, Junwei; Niu, Xinjian; Liu, Yinghui; Wang, Hui; Wei, Yanyu

2017-06-01

A large power water-cooled microwave resonance window used for the electron cyclotron resonance (ECR) ion source is investigated in this paper. The microwave characteristic simulation, thermal analysis, and structure design are deeply and successively carried out before fabrication. After the machining and welding of the components, the window is cold and hot tested. The application results demonstrate that when the input power is 2000 W, the reflected power is only 5 W. The vacuum is below 10-10 Pa, and the high power microwave operation can last 30 h continuously and reliably, which indicates that the design and assembling can achieve the high efficiency of the microwave transmission. Finally, the performance of the ECR ion source is enhanced by the improvement of the injected microwave power to the ECR plasma.

Thermally adapted design strategy of colonial houses in Surabaya

NASA Astrophysics Data System (ADS)

Antaryama, I. G. N.; Ekasiwi, S. N. N.; Mappajaya, A.; Ulum, M. S.

2018-03-01

Colonial buildings, including houses, have been considered as a representation of climate-responsive architecture. The design was thought to be a hybrid model of Dutch and tropical architecture. It was created by way of reinventing tropical and Dutch architecture design principles, and expressed in a new form, i.e. neither resembling Dutch nor tropical building. Aside from this new image, colonial house does show good climatic responses. Previous researches on colonial house generally focus on qualitative assessment of climate performance of the building. Yet this kind of study tends to concentrate on building elements, e.g. wall, window, etc. The present study is designed to give more complete picture of architecture design strategy of the house by exploring and analysing thermal performance of colonial buildings and their related architecture design strategies. Field measurements are conducted during the dry season in several colonial building in Surabaya. Air temperature and humidity are both taken, representing internal and external thermal conditions of the building. These data are then evaluated to determine thermal performance of the house. Finally, various design strategies are examined in order to reveal their significant contributions to its thermal performance. Results of the study in Surabaya confirm findings of the previous researches that are conducted in other locations, which stated that thermal performance of the house is generally good. Passive design strategies such as mass effect and ventilation play an important role in determining performance of the building.

Improved safety of retinal photocoagulation with a shaped beam and modulated pulse

NASA Astrophysics Data System (ADS)

Sramek, Christopher; Brown, Jefferson; Paulus, Yannis M.; Nomoto, Hiroyuki; Palanker, Daniel

2010-02-01

Shorter pulse durations help confine thermal damage during retinal photocoagulation, decrease treatment time and minimize pain. However, safe therapeutic window (the ratio of threshold powers for rupture and mild coagulation) decreases with shorter exposures. A ring-shaped beam enables safer photocoagulation than conventional beams by reducing the maximum temperature in the center of the spot. Similarly, a temporal pulse modulation decreasing its power over time improves safety by maintaining constant temperature for a significant portion of the pulse. Optimization of the beam and pulse shapes was performed using a computational model. In vivo experiments were performed to verify the predicted improvement. With each of these approaches, the pulse duration can be decreased by a factor of two, from 20 ms down to 10 ms while maintaining the same therapeutic window.

Magnetic properties and thermal stability of Ti-doped CrO2 films

NASA Astrophysics Data System (ADS)

Zhang, Z.; Cheng, M.; Lu, Z.; Yu, Z.; Liu, S.; Liang, R.; Liu, Y.; Shi, J.; Xiong, R.

2018-04-01

Chromium dioxide (CrO2) is a striking half metal material which may have important applications in the field of spintronics. However, pure CrO2 film is metastable at room temperature and the synthesis process can be only performed in a narrow temperature range of 390-410 °C with TiO2 used as substrate material. Here, we report the preparation and investigation of (1 0 0) oriented Ti-doped CrO2 films on TiO2 substrates. It is found that Ti-doped films can maintain pure rutile phase even after a 510 °C post-annealing, showing much better thermal stability than pure CrO2 films. Ti-doped films can be prepared in a wider temperature window (390-470 °C), which may be attributed to the improvement of thermal stability. The broadening of process window may be beneficial for further improvement of film quality by optimizing growth temperature in a larger range. In addition to the improvement of thermal stability, the magnetic properties of Ti-doped CrO2 are also found to be tuned by Ti doping: saturation magnetizations of Ti-doped films at room temperature are significantly lower, and magnetic anisotropy decreases as the Ti-concentration increases, which is beneficial for decreasing switching current density in STT-based spintronic devices.

Determination of Vertical Borehole and Geological Formation Properties using the Crossed Contour Method.

PubMed

Leyde, Brian P; Klein, Sanford A; Nellis, Gregory F; Skye, Harrison

2017-03-01

This paper presents a new method called the Crossed Contour Method for determining the effective properties (borehole radius and ground thermal conductivity) of a vertical ground-coupled heat exchanger. The borehole radius is used as a proxy for the overall borehole thermal resistance. The method has been applied to both simulated and experimental borehole Thermal Response Test (TRT) data using the Duct Storage vertical ground heat exchanger model implemented in the TRansient SYstems Simulation software (TRNSYS). The Crossed Contour Method generates a parametric grid of simulated TRT data for different combinations of borehole radius and ground thermal conductivity in a series of time windows. The error between the average of the simulated and experimental bore field inlet and outlet temperatures is calculated for each set of borehole properties within each time window. Using these data, contours of the minimum error are constructed in the parameter space of borehole radius and ground thermal conductivity. When all of the minimum error contours for each time window are superimposed, the point where the contours cross (intersect) identifies the effective borehole properties for the model that most closely represents the experimental data in every time window and thus over the entire length of the experimental data set. The computed borehole properties are compared with results from existing model inversion methods including the Ground Property Measurement (GPM) software developed by Oak Ridge National Laboratory, and the Line Source Model.

Laser window with annular grooves for thermal isolation

DOEpatents

Warner, B.E.; Horton, J.A.; Alger, T.W.

1983-07-13

A laser window or other optical element which is thermally loaded, heats up and causes optical distortions because of temperature gradients between the center and the edge. A number of annular grooves, one to three or more, are formed in the element between a central portion and edge portion, producing a web portion which concentrates the thermal gradient and thermally isolates the central portion from the edge portion, producing a uniform temperature profile across the central portion and therefore reduce the optical distortions. The grooves are narrow and closely spaced with respect to the thickness of the element, and successive grooves are formed from alternate sides of the element.

Diamond Technology Initiative

DTIC Science & Technology

1994-05-01

thermal stresses of 10 million Watts per meter, 1,000 times better than Zerodur *. This property is also important for many thermal management...products UTD has coated to date include: • Optical windows, lenses, and mirrors . Zinc sulfide infrared windows coated with a 2.5 micron-thick...implants 16, 49 microwave plasma-enhanced CVD 2 mirrors , diamond-coated 49 models of diamond growth 10, 25, 33, 34, 39 moderators 10

Ocean acidification has little effect on developmental thermal windows of echinoderms from Antarctica to the tropics.

PubMed

Karelitz, Sam E; Uthicke, Sven; Foo, Shawna A; Barker, Mike F; Byrne, Maria; Pecorino, Danilo; Lamare, Miles D

2017-02-01

As the ocean warms, thermal tolerance of developmental stages may be a key driver of changes in the geographical distributions and abundance of marine invertebrates. Additional stressors such as ocean acidification may influence developmental thermal windows and are therefore important considerations for predicting distributions of species under climate change scenarios. The effects of reduced seawater pH on the thermal windows of fertilization, embryology and larval morphology were examined using five echinoderm species: two polar (Sterechinus neumayeri and Odontaster validus), two temperate (Fellaster zelandiae and Patiriella regularis) and one tropical (Arachnoides placenta). Responses were examined across 12-13 temperatures ranging from -1.1 °C to 5.7 °C (S. neumayeri), -0.5 °C to 10.7 °C (O. validus), 5.8 °C to 27 °C (F. zelandiae), 6.0 °C to 27.1 °C (P. regularis) and 13.9 °C to 34.8 °C (A. placenta) under present-day and near-future (2100+) ocean acidification conditions (-0.3 pH units) and for three important early developmental stages 1) fertilization, 2) embryo (prehatching) and 3) larval development. Thermal windows for fertilization were broad and were not influenced by a pH decrease. Embryological development was less thermotolerant. For O. validus, P. regularis and A. placenta, low pH reduced normal development, albeit with no effect on thermal windows. Larval development in all five species was affected by both temperature and pH; however, thermal tolerance was not reduced by pH. Results of this study suggest that in terms of fertilization and development, temperature will remain as the most important factor influencing species' latitudinal distributions as the ocean continues to warm and decrease in pH, and that there is little evidence of a synergistic effect of temperature and ocean acidification on the thermal control of species ranges. © 2016 John Wiley & Sons Ltd.

A Noise Reduction Method for Dual-Mass Micro-Electromechanical Gyroscopes Based on Sample Entropy Empirical Mode Decomposition and Time-Frequency Peak Filtering

PubMed Central

Shen, Chong; Li, Jie; Zhang, Xiaoming; Shi, Yunbo; Tang, Jun; Cao, Huiliang; Liu, Jun

2016-01-01

The different noise components in a dual-mass micro-electromechanical system (MEMS) gyroscope structure is analyzed in this paper, including mechanical-thermal noise (MTN), electronic-thermal noise (ETN), flicker noise (FN) and Coriolis signal in-phase noise (IPN). The structure equivalent electronic model is established, and an improved white Gaussian noise reduction method for dual-mass MEMS gyroscopes is proposed which is based on sample entropy empirical mode decomposition (SEEMD) and time-frequency peak filtering (TFPF). There is a contradiction in TFPS, i.e., selecting a short window length may lead to good preservation of signal amplitude but bad random noise reduction, whereas selecting a long window length may lead to serious attenuation of the signal amplitude but effective random noise reduction. In order to achieve a good tradeoff between valid signal amplitude preservation and random noise reduction, SEEMD is adopted to improve TFPF. Firstly, the original signal is decomposed into intrinsic mode functions (IMFs) by EMD, and the SE of each IMF is calculated in order to classify the numerous IMFs into three different components; then short window TFPF is employed for low frequency component of IMFs, and long window TFPF is employed for high frequency component of IMFs, and the noise component of IMFs is wiped off directly; at last the final signal is obtained after reconstruction. Rotation experimental and temperature experimental are carried out to verify the proposed SEEMD-TFPF algorithm, the verification and comparison results show that the de-noising performance of SEEMD-TFPF is better than that achievable with the traditional wavelet, Kalman filter and fixed window length TFPF methods. PMID:27258276

A Noise Reduction Method for Dual-Mass Micro-Electromechanical Gyroscopes Based on Sample Entropy Empirical Mode Decomposition and Time-Frequency Peak Filtering.

PubMed

Shen, Chong; Li, Jie; Zhang, Xiaoming; Shi, Yunbo; Tang, Jun; Cao, Huiliang; Liu, Jun

2016-05-31

The different noise components in a dual-mass micro-electromechanical system (MEMS) gyroscope structure is analyzed in this paper, including mechanical-thermal noise (MTN), electronic-thermal noise (ETN), flicker noise (FN) and Coriolis signal in-phase noise (IPN). The structure equivalent electronic model is established, and an improved white Gaussian noise reduction method for dual-mass MEMS gyroscopes is proposed which is based on sample entropy empirical mode decomposition (SEEMD) and time-frequency peak filtering (TFPF). There is a contradiction in TFPS, i.e., selecting a short window length may lead to good preservation of signal amplitude but bad random noise reduction, whereas selecting a long window length may lead to serious attenuation of the signal amplitude but effective random noise reduction. In order to achieve a good tradeoff between valid signal amplitude preservation and random noise reduction, SEEMD is adopted to improve TFPF. Firstly, the original signal is decomposed into intrinsic mode functions (IMFs) by EMD, and the SE of each IMF is calculated in order to classify the numerous IMFs into three different components; then short window TFPF is employed for low frequency component of IMFs, and long window TFPF is employed for high frequency component of IMFs, and the noise component of IMFs is wiped off directly; at last the final signal is obtained after reconstruction. Rotation experimental and temperature experimental are carried out to verify the proposed SEEMD-TFPF algorithm, the verification and comparison results show that the de-noising performance of SEEMD-TFPF is better than that achievable with the traditional wavelet, Kalman filter and fixed window length TFPF methods.

Photothermal Therapy Generates a Thermal Window of Immunogenic Cell Death in Neuroblastoma.

PubMed

Sweeney, Elizabeth E; Cano-Mejia, Juliana; Fernandes, Rohan

2018-04-17

A thermal "window" of immunogenic cell death (ICD) elicited by nanoparticle-based photothermal therapy (PTT) in an animal model of neuroblastoma is described. In studies using Prussian blue nanoparticles to administer photothermal therapy (PBNP-PTT) to established localized tumors in the neuroblastoma model, it is observed that PBNP-PTT conforms to the "more is better" paradigm, wherein higher doses of PBNP-PTT generates higher cell/local heating and thereby more cell death, and consequently improved animal survival. However, in vitro analysis of the biochemical correlates of ICD (ATP, high-motility group box 1, and calreticulin) elicited by PBNP-PTT demonstrates that PBNP-PTT triggers a thermal window of ICD. ICD markers are highly expressed within an optimal temperature (thermal dose) window of PBNP-PTT (63.3-66.4 °C) as compared with higher (83.0-83.5 °C) and lower PBNP-PTT (50.7-52.7 °C) temperatures, which both yield lower expression. Subsequent vaccination studies in the neuroblastoma model confirm the in vitro findings, wherein PBNP-PTT administered within the optimal temperature window results in long-term survival (33.3% at 100 d) compared with PBNP-PTT administered within the higher (0%) and lower (20%) temperature ranges, and controls (0%). The findings demonstrate a tunable immune response to heat generated by PBNP-PTT, which should be critically engaged in the administration of PTT for maximizing its therapeutic benefits. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The dark side of Venus - Near-infrared images and spectra from the Anglo-Australian Observatory

NASA Technical Reports Server (NTRS)

Crisp, D.; Allen, D. A.; Grinspoon, D. H.; Pollack, J. B.

1991-01-01

Near-IR images and spectra of the night side of Venus taken at the Anglo-Australian Telescope during February 1990 reveal four new thermal emission windows at 1.10, 1.18, 1.27, and 1.31 microns, in addition to the previously discovered windows at 1.74 and 2.3 microns. Images of the Venus night side show similar bright and dark markings in all windows, but their contrast is much lower at short wavelengths. The 1.27-micron window includes a bright, high-altitude O2 airglow feature in addition to a thermal contribution from the deep atmosphere. Simulations of the 1.27- and 2.3-micron spectra indicate water vapor mixing ratios near 40 + or - 20 ppm by volume between the surface and the cloud base.

Smart window coating based on F-TiO2-KxWO3 nanocomposites with heat shielding, ultraviolet isolating, hydrophilic and photocatalytic performance

PubMed Central

Liu, Tongyao; Liu, Bin; Wang, Jing; Yang, Linfen; Ma, Xinlong; Li, Hao; Zhang, Yihong; Yin, Shu; Sato, Tsugio; Sekino, Tohru; Wang, Yuhua

2016-01-01

A series of smart window coated multifunctional NIR shielding-photocatalytic films were fabricated successfully through KxWO3 and F-TiO2 in a low-cost and environmentally friendly process. Based on the synergistic effect of KxWO3 and F-TiO2, the optimal proportion of KxWO3 to F-TiO2 was investigated and the FT/2KWO nanocomposite film exhibited strong near-infrared, ultraviolet light shielding ability, good visible light transmittance, high photocatalytic activity and excellent hydrophilic capacity. This film exhibited better thermal insulation capacity than ITO and higher photocatalytic activity than P25. Meanwhile, the excellent stability of this film was examined by the cycle photocatalytic degradation and thermal insulation experiments. Overall, this work is expected to provide a possibility in integrating KxWO3 with F-TiO2, so as to obtain a multifunctional NIR shielding-photocatalytic nanocomposite film in helping solve the energy crisis and deteriorating environmental issues. PMID:27265778

Thermochromic halide perovskite solar cells.

PubMed

Lin, Jia; Lai, Minliang; Dou, Letian; Kley, Christopher S; Chen, Hong; Peng, Fei; Sun, Junliang; Lu, Dylan; Hawks, Steven A; Xie, Chenlu; Cui, Fan; Alivisatos, A Paul; Limmer, David T; Yang, Peidong

2018-03-01

Smart photovoltaic windows represent a promising green technology featuring tunable transparency and electrical power generation under external stimuli to control the light transmission and manage the solar energy. Here, we demonstrate a thermochromic solar cell for smart photovoltaic window applications utilizing the structural phase transitions in inorganic halide perovskite caesium lead iodide/bromide. The solar cells undergo thermally-driven, moisture-mediated reversible transitions between a transparent non-perovskite phase (81.7% visible transparency) with low power output and a deeply coloured perovskite phase (35.4% visible transparency) with high power output. The inorganic perovskites exhibit tunable colours and transparencies, a peak device efficiency above 7%, and a phase transition temperature as low as 105 °C. We demonstrate excellent device stability over repeated phase transition cycles without colour fade or performance degradation. The photovoltaic windows showing both photoactivity and thermochromic features represent key stepping-stones for integration with buildings, automobiles, information displays, and potentially many other technologies.

Thermochromic halide perovskite solar cells

NASA Astrophysics Data System (ADS)

Lin, Jia; Lai, Minliang; Dou, Letian; Kley, Christopher S.; Chen, Hong; Peng, Fei; Sun, Junliang; Lu, Dylan; Hawks, Steven A.; Xie, Chenlu; Cui, Fan; Alivisatos, A. Paul; Limmer, David T.; Yang, Peidong

2018-03-01

Smart photovoltaic windows represent a promising green technology featuring tunable transparency and electrical power generation under external stimuli to control the light transmission and manage the solar energy. Here, we demonstrate a thermochromic solar cell for smart photovoltaic window applications utilizing the structural phase transitions in inorganic halide perovskite caesium lead iodide/bromide. The solar cells undergo thermally-driven, moisture-mediated reversible transitions between a transparent non-perovskite phase (81.7% visible transparency) with low power output and a deeply coloured perovskite phase (35.4% visible transparency) with high power output. The inorganic perovskites exhibit tunable colours and transparencies, a peak device efficiency above 7%, and a phase transition temperature as low as 105 °C. We demonstrate excellent device stability over repeated phase transition cycles without colour fade or performance degradation. The photovoltaic windows showing both photoactivity and thermochromic features represent key stepping-stones for integration with buildings, automobiles, information displays, and potentially many other technologies.

Measuring thermal conductivity of thin films and coatings with the ultra-fast transient hot-strip technique

NASA Astrophysics Data System (ADS)

Belkerk, B. E.; Soussou, M. A.; Carette, M.; Djouadi, M. A.; Scudeller, Y.

2012-07-01

This paper reports the ultra-fast transient hot-strip (THS) technique for determining the thermal conductivity of thin films and coatings of materials on substrates. The film thicknesses can vary between 10 nm and more than 10 µm. Precise measurement of thermal conductivity was performed with an experimental device generating ultra-short electrical pulses, and subsequent temperature increases were electrically measured on nanosecond and microsecond time scales. The electrical pulses were applied within metallized micro-strips patterned on the sample films and the temperature increases were analysed within time periods selected in the window [100 ns-10 µs]. The thermal conductivity of the films was extracted from the time-dependent thermal impedance of the samples derived from a three-dimensional heat diffusion model. The technique is described and its performance demonstrated on different materials covering a large thermal conductivity range. Experiments were carried out on bulk Si and thin films of amorphous SiO2 and crystallized aluminum nitride (AlN). The present approach can assess film thermal resistances as low as 10-8 K m2 W-1 with a precision of about 10%. This has never been attained before with the THS technique.

Infrared Emissivity of Tin upon Release of a 25 GPa Shock into a LiF Window

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turley, W. D., Holtkamp, D. B., Marshall, B. R., Stevens, G. D., Veeser, L. R.

We measured the emissivity of a tin sample at its interface with a lithium-fluoride window upon release of a 25 GPa shock wave from the tin into the window. Measurements were made over four wavelength bands between 1.2 and 5.4 μm. Thermal emission backgrounds from the tin, glue, and lithium fluoride were successfully removed from the reflectance signals. Emissivity changes for the sample, which was initially nearly specular, were small except for the longest wavelength band, where uncertainties were high because of poor signal-to-noise ratio at that wavelength. A thin glue layer, which bonds the sample to the window, wasmore » found to heat from reverberations of the shock wave between the tin and the lithium fluoride. At approximately 3.4 μm the thermal emission from the glue was large compared to the tin, allowing a good estimate of the glue temperature from the thermal radiance. The glue appears to remain slightly colder than the tin, thereby minimizing heat conduction into or out of the tin immediately after the shock passage.« less

Design and fabrication of a large area freestanding compressive stress SiO2 optical window

NASA Astrophysics Data System (ADS)

Van Toan, Nguyen; Sangu, Suguru; Ono, Takahito

2016-07-01

This paper reports the design and fabrication of a 7.2 mm  ×  9.6 mm freestanding compressive stress SiO2 optical window without buckling. An application of the SiO2 optical window with and without liquid penetration has been demonstrated for an optical modulator and its optical characteristic is evaluated by using an image sensor. Two methods for SiO2 optical window fabrication have been presented. The first method is a combination of silicon etching and a thermal oxidation process. Silicon capillaries fabricated by deep reactive ion etching (deep RIE) are completely oxidized to form the SiO2 capillaries. The large compressive stress of the oxide causes buckling of the optical window, which is reduced by optimizing the design of the device structure. A magnetron-type RIE, which is investigated for deep SiO2 etching, is the second method. This method achieves deep SiO2 etching together with smooth surfaces, vertical shapes and a high aspect ratio. Additionally, in order to avoid a wrinkling optical window, the idea of a Peano curve structure has been proposed to achieve a freestanding compressive stress SiO2 optical window. A 7.2 mm  ×  9.6 mm optical window area without buckling integrated with an image sensor for an optical modulator has been successfully fabricated. The qualitative and quantitative evaluations have been performed in cases with and without liquid penetration.

Determination of Vertical Borehole and Geological Formation Properties using the Crossed Contour Method

PubMed Central

Leyde, Brian P.; Klein, Sanford A; Nellis, Gregory F.; Skye, Harrison

2017-01-01

This paper presents a new method called the Crossed Contour Method for determining the effective properties (borehole radius and ground thermal conductivity) of a vertical ground-coupled heat exchanger. The borehole radius is used as a proxy for the overall borehole thermal resistance. The method has been applied to both simulated and experimental borehole Thermal Response Test (TRT) data using the Duct Storage vertical ground heat exchanger model implemented in the TRansient SYstems Simulation software (TRNSYS). The Crossed Contour Method generates a parametric grid of simulated TRT data for different combinations of borehole radius and ground thermal conductivity in a series of time windows. The error between the average of the simulated and experimental bore field inlet and outlet temperatures is calculated for each set of borehole properties within each time window. Using these data, contours of the minimum error are constructed in the parameter space of borehole radius and ground thermal conductivity. When all of the minimum error contours for each time window are superimposed, the point where the contours cross (intersect) identifies the effective borehole properties for the model that most closely represents the experimental data in every time window and thus over the entire length of the experimental data set. The computed borehole properties are compared with results from existing model inversion methods including the Ground Property Measurement (GPM) software developed by Oak Ridge National Laboratory, and the Line Source Model. PMID:28785125

Management of heat in laser tissue welding using NIR cover window material.

PubMed

Sriramoju, Vidyasagar; Savage, Howard; Katz, Alvin; Muthukattil, Ronex; Alfano, Robert R

2011-12-01

Laser tissue welding (LTW) is a novel method of surgical wound closure by the use of laser radiation to induce fusion of the biological tissues. Molecular dynamics associated with LTW is a result of thermal and non-thermal mechanisms. This research focuses exclusively on better heat management to reduce thermal damage of tissues in LTW using a near infrared laser radiation. An infrared continuous-wave (CW) laser radiation at 1,450 nm wavelength corresponding to the absorption band from combination vibrational modes of water is used to weld together ex vivo porcine aorta. In these studies we measured the optimal laser power and scan speed, for better tensile strength of the weld and lesser tissue dehydration. Significant amount of water loss from the welded tissue results in cellular death and tissue buckling. Various thermally conductive optical cover windows were used as heat sinks to reduce thermal effects during LTW for the dissipation of the heat. The optimal use of the method prevents tissue buckling and minimizes the water loss. Diamond, sapphire, BK7, fused silica, and IR quartz transparent optical cover windows were tested. The data from this study suggests that IR-quartz as the material with optimal thermal conductivity is ideal for laser welding of the porcine aorta. Copyright © 2011 Wiley Periodicals, Inc.

Design and fabrication of absorber coupled TES microbolometers on continuous silicon-nitride windows.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, C. L.; Carlstrom, J. E.; Datesman, A.

2008-04-01

The implementation of TES based microbolometer arrays will achieve unprecedented sensitivities for mm and sub-mm astronomy through fabrication of large format arrays and improved linearity and stability arising from strong electro-thermal feedback. We report on progress in developing TES microbolometers using Mo/Au thin films and Au absorbing structures. We present measurements of suppressing the thermal conductance through the etching of features on a continuous Silicon-Nitride window.

Single Project Replaces District's Windows.

ERIC Educational Resources Information Center

American School and University, 1981

1981-01-01

The towns of Maplewood and South Orange (New Jersey) earmarked over $1 million, raised from a bond issue, to replace with thermal aluminum-framed units the 2400 worn out windows in eight 50-year-old schools. (Author)

Micromachined single-level nonplanar polycrystalline SiGe thermal microemitters for infrared dynamic scene projection

NASA Astrophysics Data System (ADS)

Malyutenko, V. K.; Malyutenko, O. Yu.; Leonov, V.; Van Hoof, C.

2009-05-01

The technology for self-supported membraneless polycrystalline SiGe thermal microemitters, their design, and performance are presented. The 128-element arrays with a fill factor of 88% and a 2.5-μm-thick resonant cavity have been grown by low-pressure chemical vapor deposition and fabricated using surface micromachining technology. The 200-nm-thick 60×60 μm2 emitting pixels enforced with a U-shape profile pattern demonstrate a thermal time constant of 2-7 ms and an apparent temperature of 700 K in the 3-5 and 8-12 μm atmospheric transparency windows. The application of the devices to the infrared dynamic scene simulation and their benefit over conventional planar membrane-supported emitters are discussed.

Daylighting and shuttering: RIB system mechanical design and preliminary performance data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinney, L.; Reynolds, D.

1983-12-01

The Reflective, Insulating Blind (RIB) system is a flexible, user-controlled daylighting device which also has direct thermal advantages: it can reject a considerable portion of summer sun while still retaining an adequate daylighting function; and it functions as moveable insulation to significantly decrease thermal losses through fenestration during evening hours. The conceptual design of the RIB system was accomplished by Barnes and Shapira at the Oak Ridge National Laboratory (ORNL). Mechanical design and prototype fabrication was accomplished by the authors and 29 systems were installed immediately inside existing south-facing windows of an energy-efficient office and dormitory at ORNL. The buildingmore » is a heavily-instrumented, passively-solar-heated structure for which reliable performance data was gathered and analyzed before the addition of RIB systems, thus facilitating the interpretation of ''after RIB'' performance data.« less

Energy efficiency evaluation of hospital building office

NASA Astrophysics Data System (ADS)

Fitriani, Indah; Sangadji, Senot; Kristiawan, S. A.

2017-01-01

One of the strategy employed in building design is reducing energy consumption while maintaining the best comfort zone in building indoor climate. The first step to improve office buildings energy performance by evaluating its existing energy usage using energy consumption intensity (Intensitas Konsumsi Energi, IKE) index. Energy evaluation of office building for hospital dr. Sayidiman at Kabupaten Magetan has been carried out in the initial investigation. The office building is operated with active cooling (air conditioning, AC) and use limited daylighting which consumes 14.61 kWh/m2/month. This IKE value is attributed into a slightly inefficient category. Further investigation was carried out by modeling and simulating thermal energy load and room lighting in every building zone using of Ecotect from Autodesk. Three scenarios of building energy and lighting retrofit have been performed simulating representing energy efficiency using cross ventilation, room openings, and passive cooling. The results of the numerical simulation indicate that the third scenario by employing additional windows, reflector media and skylight exhibit the best result and in accordance with SNI 03-6575-2001 lighting standard. Total thermal load of the existing building which includes fabric gains, indirect solar gains, direct solar gains, ventilation fans, internal gains, inter-zonal gains and cooling load were 162,145.40 kWh. Based on the three scenarios, the thermal load value (kWh) obtained was lowest achieved scenario 2 with the thermal value of 117,539.08 kWh.The final results are interpreted from the total energy emissions evaluated using the Ecotect software, the heating and cooling demand value and specific design of the windows are important factors to determine the energy efficiency of the buildings.

Side-by-Side Field Evaluation of Highly Insulating Windows in the PNNL Lab Homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Widder, Sarah H.; Parker, Graham B.; Baechler, Michael C.

2012-08-01

To examine the energy, air leakage, and thermal performance of highly insulating windows, a field evaluation was undertaken in a matched pair of all-electric, factory-built “Lab Homes” located on the Pacific Northwest National Laboratory (PNNL) campus in Richland, Washington. The “baseline” Lab Home B was retrofitted with “standard” double-pane clear aluminum-frame slider windows and patio doors, while the “experimental” Lab Home A was retrofitted with Jeld-Wen® triple-pane vinyl-frame slider windows and patio doors with a U-factor of 0.2 and solar heat gain coefficient of 0.19. To assess the window, the building shell air leakage, energy use, and interior temperatures ofmore » each home were compared during the 2012 winter heating and summer cooling seasons. The measured energy savings in Lab Home B averaged 5,821 watt-hours per day (Wh/day) during the heating season and 6,518 Wh/day during the cooling season. The overall whole-house energy savings of Lab Home B compared to Lab Home A are 11.6% ± 1.53% for the heating season and 18.4 ± 2.06% for the cooling season for identical occupancy conditions with no window coverings deployed. Extrapolating these energy savings numbers based on typical average heating degree days and cooling degree days per year yields an estimated annual energy savings of 12.2%, or 1,784 kWh/yr. The data suggest that highly insulating windows are an effective energy-saving measure that should be considered for high-performance new homes and in existing retrofits. However, the cost effectiveness of the measure, as determined by the simple payback period, suggests that highly insulating window costs continue to make windows difficult to justify on a cost basis alone. Additional reductions in costs via improvements in manufacturing and/or market penetration that continue to drive down costs will make highly insulating windows much more viable as a cost-effective energy efficiency measure. This study also illustrates that highly insulating windows have important impacts on peak load, occupant comfort, and condensation potential, which are not captured in the energy savings calculation. More consistent and uniform interior temperature distributions suggest that highly insulated windows, as part of a high performance building envelope, may enable more centralized duct design and downsized HVAC systems. Shorter, more centralized duct systems and smaller HVAC systems to yield additional cost savings, making highly insulating windows more cost effective as part of a package of new construction or retrofit measures which achieve significant reductions in home energy use.« less

Radiation, Thermal Gradient and Weight: a threefold dilemma for PLATO

NASA Astrophysics Data System (ADS)

Magrin, Demetrio; Ragazzoni, Roberto; Bruno, Giordano; Piazza, Daniele; Borsa, Francesco; Ghigo, Mauro; Mogulsky, Valery; Bergomi, Maria; Biondi, Federico; Chinellato, Simonetta; Dima, Marco; Farinato, Jacopo; Greggio, Davide; Gullieuszik, Marco; Marafatto, Luca; Viotto, Valentina; Munari, Matteo; Pagano, Isabella; Sicilia, Daniela; Basso, Stefano; Spiga, Daniele; Bandy, Timothy; Brändli, Mathias; Benz, Willy; De Roche, Thierry; Rieder, Martin; Brandeker, Alexis; Klebor, Maximilian; Schweitzer, Mario; Wieser, Matthias; Erikson, Anders; Rauer, Heike

2016-07-01

The project PLAnetary Transits and Oscillations of stars (PLATO) is one of the selected medium class (M class) missions in the framework of the ESA Cosmic Vision 2015-2025 program. The mean scientific goal of PLATO is the discovery and study of extrasolar planetary systems by means of planetary transits detection. The opto mechanical subsystem of the payload is made of 32 normal telescope optical units (N-TOUs) and 2 fast telescope optical units (FTOUs). The optical configuration of each TOU is an all refractive design based on six properly optimized lenses. In the current baseline, in front of each TOU a Suprasil window is foreseen. The main purposes of the entrance window are to shield the following lenses from possible damaging high energy radiation and to mitigate the thermal gradient that the first optical element will experience during the launch from ground to space environment. In contrast, the presence of the window increases the overall mass by a non-negligible quantity. We describe here the radiation and thermal analysis and their impact on the quality and risks assessment, summarizing the trade-off process with pro and cons on having or dropping the entrance window in the optical train.

Performative building envelope design correlated to solar radiation and cooling energy consumption

NASA Astrophysics Data System (ADS)

Jacky, Thiodore; Santoni

2017-11-01

Climate change as an ongoing anthropogenic environmental challenge is predominantly caused by an amplification in the amount of greenhouse gases (GHGs), notably carbon dioxide (CO2) in building sector. Global CO2 emissions are emitted from HVAC (Heating, Ventilation, and Air Conditioning) occupation to provide thermal comfort in building. In fact, the amount of energy used for cooling or heating building is implication of building envelope design. Building envelope acts as interface layer of heat transfer between outdoor environment and the interior of a building. It appears as wall, window, roof and external shading device. This paper examines performance of various design strategy on building envelope to limit solar radiation and reduce cooling loads in tropical climate. The design strategies are considering orientation, window to wall ratio, material properties, and external shading device. This research applied simulation method using Autodesk Ecotect to investigate simultaneously between variations of wall and window ratio, shading device composition and the implication to the amount of solar radiation, cooling energy consumption. Comparative analysis on the data will determine logical variation between opening and shading device composition and cooling energy consumption. Optimizing the building envelope design is crucial strategy for reducing CO2 emissions and long-term energy reduction in building sector. Simulation technology as feedback loop will lead to better performative building envelope.

Solar Transparent Radiators by Optical Nanoantennas.

PubMed

Jönsson, Gustav; Tordera, Daniel; Pakizeh, Tavakol; Jaysankar, Manoj; Miljkovic, Vladimir; Tong, Lianming; Jonsson, Magnus P; Dmitriev, Alexandre

2017-11-08

Architectural windows are a major cause of thermal discomfort as the inner glazing during cold days can be several degrees colder than the indoor air. Mitigating this, the indoor temperature has to be increased, leading to unavoidable thermal losses. Here we present solar thermal surfaces based on complex nanoplasmonic antennas that can raise the temperature of window glazing by up to 8 K upon solar irradiation while transmitting light with a color rendering index of 98.76. The nanoantennas are directional, can be tuned to absorb in different spectral ranges, and possess a structural integrity that is not substrate-dependent, and thus they open up for application on a broad range of surfaces.

Field Evaluation of Highly Insulating Windows in the Lab Homes: Winter Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, Graham B.; Widder, Sarah H.; Bauman, Nathan N.

2012-06-01

This field evaluation of highly insulating windows was undertaken in a matched pair of 'Lab Homes' located on the Pacific Northwest National Laboratory (PNNL) campus during the 2012 winter heating season. Improving the insulation and solar heat gain characteristics of a home's windows has the potential to significantly improve the home's building envelope and overall thermal performance by reducing heat loss (in the winter), and cooling loss and solar heat gain (in the summer) through the windows. A high quality installation and/or window retrofit will also minimize or reduce air leakage through the window cavity and thus also contribute tomore » reduced heat loss in the winter and cooling loss in the summer. These improvements all contribute to decreasing overall annual home energy use. Occupant comfort (non-quantifiable) can also be increased by minimizing or eliminating the cold 'draft' (temperature) many residents experience at or near window surfaces that are at a noticeably lower temperature than the room air temperature. Lastly, although not measured in this experiment, highly insulating windows (triple-pane in this experiment) also have the potential to significantly reduce the noise transmittance through windows compared to standard double-pane windows. The metered data taken in the Lab Homes and data analysis presented here represent 70 days of data taken during the 2012 heating season. As such, the savings from highly insulating windows in the experimental home (Lab Home B) compared to the standard double-pane clear glass windows in the baseline home (Lab Home A) are only a portion of the energy savings expected from a year-long experiment that would include a cooling season. The cooling season experiment will take place in the homes in the summer of 2012, and results of that experiment will be reported in a subsequent report available to all stakeholders.« less

High-performance 193-nm photoresist materials based on ROMA polymers: sub-90-nm contact hole application with resist reflow

NASA Astrophysics Data System (ADS)

Joo, Hyun S.; Seo, Dong C.; Kim, Chang M.; Lim, Young T.; Cho, Seong D.; Lee, Jong B.; Song, Ji Y.; Kim, Kyoung M.; Park, Joo H.; Jung, Jae Chang; Shin, Ki S.; Bok, Cheol Kyu; Moon, Seung C.

2004-05-01

There are numerous methods being explored by lithographers to achieve the patterning of sub-90nm contact hole features. Regarding optical impact on contact imaging, various optical extension techniques such as assist features, focus drilling, phase shift masks, and off-axis illumination are being employed to improve the aerial image. One possible option for improving of the process window in contact hole patterning is resist reflow. We have already reported the resist using a ring opened polymer of maleic anhydride unit(ROMA) during the past two years in this conference. It has several good properties such as UV transmittance, PED stability, solubility and storage stability. The resist using ROMA polymer as a matrix resin showed a good lithographic performance at C/H pattern and one of the best characteristics in a ROMA polymer is the property of thermal shrinkage. It has a specific glass transition temperature(Tg) each polymers, so they made a applying of resist reflow technique to print sub-90nm C/H possible. Recently, we have researched about advanced ROMA polymer(ROMA II), which is composed of cycloolefine derivatives with existing ROMA type polymer(ROMA I), for dry etch resistance increasing, high resolution, and good thermal shrinkage property. In this paper, we will present the structure, thermal shrinkage properties, Tg control, material properties for ROMA II polymer and will show characteristics, the lithographic performance for iso and dense C/H applications of the resist using ROMA II polymer. In addition, we will discuss resist reflow data gained at C/H profile of sub-90nm sizes, which has good process window.

DOE Office of Scientific and Technical Information (OSTI.GOV)

A. Herk; Poerschke, A.; Beach, R.

In 2012-2013, IBACOS worked with a builder, Brookfield Homes in Denver, Colorado, to design and construct a Passive House certified model home. IBACOS used several modeling programs and calculation methods to complete the final design package along with Brookfield's architect KGA Studio. This design package included upgrades to the thermal enclosure, basement insulation, windows, and heating, ventilation, and air conditioning. Short-term performance testing in the Passive House was done during construction and after construction.

Engine management during NTRE start up

NASA Technical Reports Server (NTRS)

Bulman, Mel; Saltzman, Dave

1993-01-01

The topics are presented in viewgraph form and include the following: total engine system management critical to successful nuclear thermal rocket engine (NTRE) start up; NERVA type engine start windows; reactor power control; heterogeneous reactor cooling; propellant feed system dynamics; integrated NTRE start sequence; moderator cooling loop and efficient NTRE starting; analytical simulation and low risk engine development; accurate simulation through dynamic coupling of physical processes; and integrated NTRE and mission performance.

DPAL: Historical Perspective And Summary Of Achievements

DTIC Science & Technology

2013-08-20

of a gas gain medium. The thermal effects existing, for example, in solid state lasers cause aberrations and thermal lensing that degrade the beam...and 500 torr of ethane buffer gas had windows AR coated on both sides (external and internal) and was kept at 98°C. The pump and lasing beams were...back mirror. A 2 cm long cell with antireflection coated windows was filled with metallic cesium and 500 Torr ethane and placed in a heated oven with a

Study of Mechanical and Thermal Impact of a Plasma Focus Discharge on Diagnostic Elements of PFM-72M Installation

NASA Astrophysics Data System (ADS)

Bashutin, O. A.; Savelov, A. S.; Sidorov, P. P.

2017-12-01

Mechanical and thermal impact of the plasma focus discharge on structural elements of diagnostic windows of the PFM-72m discharge installation are calculated. The absence of critical impact at early discharge stages and during the first 300 ns after the "plasma focus" formation is shown. The possibility of shock impact on the surface of diagnostic windows at later times, which may result in their substantial deformation and destruction, is demonstrated.

Computational model of retinal photocoagulation and rupture

NASA Astrophysics Data System (ADS)

Sramek, Christopher; Paulus, Yannis M.; Nomoto, Hiroyuki; Huie, Phil; Palanker, Daniel

2009-02-01

In patterned scanning laser photocoagulation, shorter duration (< 20 ms) pulses help reduce thermal damage beyond the photoreceptor layer, decrease treatment time and minimize pain. However, safe therapeutic window (defined as the ratio of rupture threshold power to that of light coagulation) decreases for shorter exposures. To quantify the extent of thermal damage in the retina, and maximize the therapeutic window, we developed a computational model of retinal photocoagulation and rupture. Model parameters were adjusted to match measured thresholds of vaporization, coagulation, and retinal pigment epithelial (RPE) damage. Computed lesion width agreed with histological measurements in a wide range of pulse durations and power. Application of ring-shaped beam profile was predicted to double the therapeutic window width for exposures in the range of 1 - 10 ms.

Investigating crater lake warming using ASTER thermal imagery: Case studies at Ruapehu, Poás, Kawah Ijen, and Copahué Volcanoes

NASA Astrophysics Data System (ADS)

Trunk, Laura; Bernard, Alain

2008-12-01

A two-channel or split-window algorithm designed to correct for atmospheric conditions was applied to thermal images taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) of Lake Yugama on Kusatsu-Shirane volcano in Japan in order to measure the temperature of its crater lake. These temperature calculations were validated using lake water temperatures that were collected on the ground. Overall, the agreement between the temperatures calculated using the split-window method and ground truth is quite good, typically ± 1.5 °C for cloud-free images. Data from fieldwork undertaken in the summer of 2004 at Kusatsu-Shirane allow a comparison of ground-truth data with the radiant temperatures measured using ASTER imagery. Further images were analyzed of Ruapehu, Poás, Kawah Ijen, and Copahué volcanoes to acquire time-series of lake temperatures. A total of 64 images of these 4 volcanoes covering a wide range of geographical locations and climates were analyzed. Results of the split-window algorithm applied to ASTER images are reliable for monitoring thermal changes in active volcanic lakes. These temperature data, when considered in conjunction with traditional volcano monitoring techniques, lead to a better understanding of whether and how thermal changes in crater lakes aid in eruption forecasting.

Thermal Analysis for Monitoring Effects of Shock-Induced Physical, Mechanical, and Chemical Changes in Materials

DTIC Science & Technology

2015-01-19

MS WINDOWS platform, which enables multitasking with simultaneous evaluation and operation 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13...measurement and analysis software for data acquisition, storage and evaluation with MS WINDOWS platform, which enables multitasking with simultaneous...Proteus measurement and analysis software for data acquisition, storage and evaluation with MS WINDOWS platform, which enables multitasking with

Micrometeoroid and Orbital Debris (MMOD) Shield Ballistic Limit Analysis Program

NASA Technical Reports Server (NTRS)

Ryan, Shannon

2013-01-01

This software implements penetration limit equations for common micrometeoroid and orbital debris (MMOD) shield configurations, windows, and thermal protection systems. Allowable MMOD risk is formulated in terms of the probability of penetration (PNP) of the spacecraft pressure hull. For calculating the risk, spacecraft geometry models, mission profiles, debris environment models, and penetration limit equations for installed shielding configurations are required. Risk assessment software such as NASA's BUMPERII is used to calculate mission PNP; however, they are unsuitable for use in shield design and preliminary analysis studies. The software defines a single equation for the design and performance evaluation of common MMOD shielding configurations, windows, and thermal protection systems, along with a description of their validity range and guidelines for their application. Recommendations are based on preliminary reviews of fundamental assumptions, and accuracy in predicting experimental impact test results. The software is programmed in Visual Basic for Applications for installation as a simple add-in for Microsoft Excel. The user is directed to a graphical user interface (GUI) that requires user inputs and provides solutions directly in Microsoft Excel workbooks.

CMOS minimal array

NASA Astrophysics Data System (ADS)

Janesick, James; Cheng, John; Bishop, Jeanne; Andrews, James T.; Tower, John; Walker, Jeff; Grygon, Mark; Elliot, Tom

2006-08-01

A high performance prototype CMOS imager is introduced. Test data is reviewed for different array formats that utilize 3T photo diode, 5T pinned photo diode and 6T photo gate CMOS pixel architectures. The imager allows several readout modes including progressive scan, snap and windowed operation. The new imager is built on different silicon substrates including very high resistivity epitaxial wafers for deep depletion operation. Data products contained in this paper focus on sensor's read noise, charge capacity, charge transfer efficiency, thermal dark current, RTS dark spikes, QE, pixel cross- talk and on-chip analog circuitry performance.

New WC-Cu thermal barriers for fusion applications: High temperature mechanical behaviour

NASA Astrophysics Data System (ADS)

Tejado, E.; Dias, M.; Correia, J. B.; Palacios, T.; Carvalho, P. A.; Alves, E.; Pastor, J. Y.

2018-01-01

The combination of tungsten carbide and copper as a thermal barrier could effectively reduce the thermal mismatch between tungsten and copper alloy, which are proposed as base armour and heat sink, respectively, in the divertor of future fusion reactors. Furthermore, since the optimum operating temperature windows for these divertor materials do not overlap, a compatible thermal barrier interlayer between them is required to guarantee a smooth thermal transition, which in addition may mitigate radiation damage. The aim of this work is to study the thermo-mechanical properties of WC-Cu cermets fabricated by hot pressing. Focus is placed on the temperature effect and composition dependence, as the volume fraction of copper varies from 25 to 50 and 75 vol%. To explore this behaviour, fracture experiments are performed within a temperature range from room temperature to 800 °C under vacuum. In addition, elastic modulus and thermal expansion coefficient are estimated from these tests. Results reveal a strong dependence of the performance on temperature and on the volume fraction of copper and, surprisingly, a slight percent of Cu (25 vol%) can effectively reduce the large difference in thermal expansion between tungsten and copper alloy, which is a critical point for in service applications. The thermal performance of these materials, together with their mechanical properties could indeed reduce the heat transfer from the PFM to the underlying element while supporting the high thermal stresses of the joint. Thus, the presence of these cermets could allow the reactor to operate above the ductile to brittle transition temperature of tungsten, without compromising the underlying materials.

High temperature antenna development for space shuttle, volume 1

NASA Technical Reports Server (NTRS)

Kuhlman, E. A.

1973-01-01

Design concepts for high temperature flush mounted Space Shuttle Orbiter antenna systems are discussed. The design concepts include antenna systems for VHF, L-band, S-band, C-band and Ku-band frequencies. The S-band antenna system design was completed and test hardware fabricated. It was then subjected to electrical and thermal testing to establish design requirements and determine reuse capabilities. The thermal tests consisted of applying ten high temperature cycles simulating the Orbiter entry heating environment in an arc tunnel plasma facility and observing the temperature distributions. Radiation pattern and impedance measurements before and after high temperature exposure were used to evaluated the antenna systems performance. Alternate window design concepts are considered. Layout drawings, supported by thermal and strength analyses, are given for each of the antenna system designs. The results of the electrical and thermal testing of the S-band antenna system are given.

Laser-Induced Thermal-Mechanical Damage Characteristics of Cleartran Multispectral Zinc Sulfide with Temperature-Dependent Properties

NASA Astrophysics Data System (ADS)

Peng, Yajing; Jiang, Yanxue; Yang, Yanqiang

2015-01-01

Laser-induced thermal-mechanical damage characteristics of window materials are the focus problems in laser weapon and anti-radiation reinforcement technology. Thermal-mechanical effects and damage characteristics are investigated for cleartran multispectral zinc sulfide (ZnS) thin film window materials irradiated by continuous laser using three-dimensional (3D) thermal-mechanical model. Some temperature-dependent parameters are introduced into the model. The temporal-spatial distributions of temperature and thermal stress are exhibited. The damage mechanism is analyzed. The influences of temperature effect of material parameters and laser intensity on the development of thermal stress and the damage characteristics are examined. The results show, the von Mises equivalent stress along the thickness direction is fluctuant, which originates from the transformation of principal stresses from compressive stress to tensile stress with the increase of depth from irradiated surface. The damage originates from the thermal stress but not the melting. The thermal stress is increased and the damage is accelerated by introducing the temperature effect of parameters or the increasing laser intensity.

Method of improving the performance of lenses for use in thermal infrared

NASA Astrophysics Data System (ADS)

McDowell, M. W.; Klee, H. W.

1980-10-01

A method is described whereby the field performance of an all-germanium triplet, as used for imaging radiation in the 8 to 13 micron waveband, can be improved. The principle of the method, which could also be used to improve the performance of achromatic triplets or aspherized doublets, involves the use of a field flattener lens which replaces the germanium window of the detector. The curvature of this lens can be optimized to minimize field curvature, which together with chromatic aberration is one of the most serious residuals of thermal imaging systems with relative apertures of around f/0.7. It is also shown that for such relative apertures, and for typical fields of less than 15 degrees, at 100 mm focal length, the location of the aperture stop is not a significant design parameter. This arises as a result of the intrinsic optical properties of germanium.

Performance Standards for Windows | Efficient Windows Collaborative

Science.gov Websites

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Silicon Oil DC200(R)5CST as AN Alternative Coolant for Cvd Diamond Windows

NASA Astrophysics Data System (ADS)

Vaccaro, A.; Aiello, G.; Meier, A.; Schere, T.; Schreck, S.; Spaeh, P.; Strauss, D.; Gantenbein, G.

2011-02-01

The production of high power mm-wave radiation is a key technology in large fusion devices, since it is required for localized plasma heating and current drive. Transmission windows are necessary to keep the vacuum in the gyrotron system and also act as tritium barriers. With its excellent optical, thermal and mechanical properties, synthetic CVD (Chemical Vapor Deposition) diamond is the state of the art material for the cw transmission of the mm-wave beams produced by high power gyrotrons. The gyrotrons foreseen for the W7-X stellarator are designed for cw operation with 1 MW output power at 140 GHz. The output window unit is designed by TED (Thales Electron Devices, France) using a single edge circumferentially cooled CVD-diamond disc with an aperture of 88 mm. The window unit is cooled by de-ionized water which is considered as chemical aggressive and might cause corrosion in particular at the brazing. The use of a different coolant such as silicon oil could prevent this issue. The cooling circuit has been simulated by steady-state CFD analysis. A total power generation of 1 kW (RF transmission losses) with pure Gaussian distribution has been assumed for the diamond disc. The performance of both water and the industrial silicon oil DC200(R) have been investigated and compared with a focus on the temperature distribution on the disc, the pressure drop across the cooling path and the heat flux distribution. Although the silicon oil has a higher viscosity (~x5), lower heat capacity (~x1/2) and lower thermal conductivity (~x1/3), it has proven to be a good candidate as alternative to water.

Optical performance of the SO/PHI full disk telescope due to temperature gradients effect on the heat rejection entrance window

NASA Astrophysics Data System (ADS)

Garranzo, D.; Núñez, A.; Zuluaga-Ramírez, P.; Barandiarán, J.; Fernández-Medina, A.; Belenguer, T.; Álvarez-Herrero, A.

2017-11-01

The Polarimetric Helioseismic Imager for Solar Orbiter (SO/PHI) is an instrument on board in the Solar Orbiter mission. The Full Disk Telescope (FDT) will have the capability of providing images of the solar disk in all orbital faces with an image quality diffraction-limited. The Heat Rejection Entrance Window (HREW) is the first optical element of the instrument. Its function is to protect the instrument by filtering most of the Solar Spectrum radiation. The HREW consists of two parallel-plane plates made from Suprasil and each surface has a coating with a different function: an UV shield coating, a low pass band filter coating, a high pass band filter coating and an IR shield coating, respectively. The temperature gradient on the HREW during the mission produces a distortion of the transmitted wave-front due to the dependence of the refractive index with the temperature (thermo-optic effect) mainly. The purpose of this work is to determine the capability of the PHI/FDT refocusing system to compensate this distortion. A thermal gradient profile has been considered for each surface of the plates and a thermal-elastic analysis has been done by Finite Element Analysis to determine the deformation of the optical elements. The Optical Path Difference (OPD) between the incident and transmitted wavefronts has been calculated as a function of the ray tracing and the thermo-optic effect on the optical properties of Suprasil (at the work wavelength of PHI) by means of mathematical algorithms based on the 3D Snell Law. The resultant wavefronts have been introduced in the optical design of the FDT to evaluate the performance degradation of the image at the scientific focal plane and to estimate the capability of the PHI refocusing system for maintaining the image quality diffraction-limited. The analysis has been carried out considering two different situations: thermal gradients due to on axis attitude of the instrument and thermal gradients due to 1° off pointing attitude. The effect over the boresight at the instrument focal plane has also been analyzed. The results show that the effect of the FDT HREW thermal gradients on the FDT performance can be optically corrected. The influence of the thermal gradients on the system is also presented.

Thermal and Lorentz Force Analysis of Beryllium Windows for the Rectilinear Muon Cooling Channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Tianhuan; Li, D.; Virostek, S.

Reduction of the 6-dimensional phase-space of a muon beam by several orders of magnitude is a key requirement for a Muon Collider. Recently, a 12-stage rectilinear ionization cooling channel has been proposed to achieve that goal. The channel consists of a series of low frequency (325 MHz-650 MHz) normal conducting pillbox cavities, which are enclosed with thin beryllium windows (foils) to increase shunt impedance and give a higher field on-axis for a given amount of power. These windows are subject to ohmic heating from RF currents and Lorentz force from the EM field in the cavity, both of which willmore » produce out of the plane displacements that can detune the cavity frequency. In this study, using the TEM3P code, we report on a detailed thermal and mechanical analysis for the actual Be windows used on a 325 MHz cavity in a vacuum ionization cooling rectilinear channel for a Muon Collider.« less

Thermal and Lorentz force analysis of beryllium windows for a rectilinear muon cooling channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, T.; Stratakis, D.; Li, D.

Reduction of the 6-dimensional phase-space of a muon beam by several orders of magnitude is a key requirement for a Muon Collider. Recently, a 12-stage rectilinear ionization cooling channel has been proposed to achieve that goal. The channel consists of a series of low frequency (325 MHz-650 MHz) normal conducting pillbox cavities, which are enclosed with thin beryllium windows (foils) to increase shunt impedance and give a higher field on-axis for a given amount of power. These windows are subject to ohmic heating from RF currents and Lorentz force from the EM field in the cavity, both of which willmore » produce out of the plane displacements that can detune the cavity frequency. In this study, using the TEM3P code, we report on a detailed thermal and mechanical analysis for the actual Be windows used on a 325 MHz cavity in a vacuum ionization cooling rectilinear channel for a Muon Collider.« less

Assessment of candidates for target window material in accelerator-driven molybdenum-99 production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strons, Philip; Bailey, James; Makarashvili, Vakhtang

2016-10-01

NorthStar Medical Technologies is pursuing production of an important medical isotope, Mo-99, through a photo-nuclear reaction of a Mo-100 target using a high-power electron accelerator. The current target utilizes an Inconel 718 window. The purpose of this study was to evaluate other candidate materials for the target window, which separates the high-pressure helium gas inside the target from the vacuum inside the accelerator beamline and is subjected to significant stress. Our initial analysis assessed the properties (density, thermal conductivity, maximum stress, minimum window thickness, maximum temperature, and figure of merit) for a range of materials, from which the three mostmore » promising were chosen: Inconel 718, 250 maraging steel, and standard-grade beryllium. These materials were subjected to further analysis to determine the effects of thermal and mechanical strain versus beam power at varying thicknesses. Both beryllium and the maraging steel were calculated to withstand more than twice as high beam power than Inconel 718.« less

Flexible transparent aerogels as window retrofitting films and optical elements with tunable birefringence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Qingkun; Frazier, Allister W.; Zhao, Xinpeng

Experimental realization of optically transparent, mechanically robust and flexible aerogels has been a longstanding challenge, which limits their practical applications in energy-saving devices, such as thermally insulating films for enhancing energy efficiency of windows. The poor transparency precluded even hypothetical consideration of the possibility of birefringent aerogels. We develop birefringent and optically isotropic aerogels that combine properties of thermal super-insulation, mechanical robustness and flexibility, and transparency to visible-spectrum light. This unusual combination of physical properties is achieved by combining liquid crystalline self-organization of cellulose nanofibers with polysiloxane cross-linking and control of the nanoscale porosity to form hybrid organic-inorganic mesostructured aerogels.more » Potential applications of these inexpensive materials range from single pane window retrofitting to smart fabrics.« less

Effects of ocean acidification increase embryonic sensitivity to thermal extremes in Atlantic cod, Gadus morhua.

PubMed

Dahlke, Flemming T; Leo, Elettra; Mark, Felix C; Pörtner, Hans-Otto; Bickmeyer, Ulf; Frickenhaus, Stephan; Storch, Daniela

2017-04-01

Thermal tolerance windows serve as a powerful tool for estimating the vulnerability of marine species and their life stages to increasing temperature means and extremes. However, it remains uncertain to which extent additional drivers, such as ocean acidification, modify organismal responses to temperature. This study investigated the effects of CO 2 -driven ocean acidification on embryonic thermal sensitivity and performance in Atlantic cod, Gadus morhua, from the Kattegat. Fertilized eggs were exposed to factorial combinations of two PCO 2 conditions (400 μatm vs. 1100 μatm) and five temperature treatments (0, 3, 6, 9 and 12 °C), which allow identifying both lower and upper thermal tolerance thresholds. We quantified hatching success, oxygen consumption (MO 2 ) and mitochondrial functioning of embryos as well as larval morphometrics at hatch and the abundance of acid-base-relevant ionocytes on the yolk sac epithelium of newly hatched larvae. Hatching success was high under ambient spawning conditions (3-6 °C), but decreased towards both cold and warm temperature extremes. Elevated PCO 2 caused a significant decrease in hatching success, particularly at cold (3 and 0 °C) and warm (12 °C) temperatures. Warming imposed limitations to MO 2 and mitochondrial capacities. Elevated PCO 2 stimulated MO 2 at cold and intermediate temperatures, but exacerbated warming-induced constraints on MO 2 , indicating a synergistic interaction with temperature. Mitochondrial functioning was not affected by PCO 2 . Increased MO 2 in response to elevated PCO 2 was paralleled by reduced larval size at hatch. Finally, ionocyte abundance decreased with increasing temperature, but did not differ between PCO 2 treatments. Our results demonstrate increased thermal sensitivity of cod embryos under future PCO 2 conditions and suggest that acclimation to elevated PCO 2 requires reallocation of limited resources at the expense of embryonic growth. We conclude that ocean acidification constrains the thermal performance window of embryos, which has important implication for the susceptibility of cod to projected climate change. © 2016 John Wiley & Sons Ltd.

Optical effect of the contamination of infrared windows by the outgassing of materials in outer space

NASA Technical Reports Server (NTRS)

Silberman, E.

1975-01-01

The composition and evaporation rate of the outgassing of a space vehicle thermal control paint as a function of temperature were studied. A contamination chamber was designed, constructed, and tested. Samples of thermal control paint were tested to determine if heating to moderate temperatures causes them to release outgassing products which can be collected on a cooled cesium iodide window for identification by IR analysis. Results showed that outgassing of surfaces other than the sample was a problem. Spectral bands of the deposits collected were compared.

Noise and Sonic Boom Impact Technology. Sonic Boom Damage to Conventional Structures

DTIC Science & Technology

1989-02-01

Pallant (21) reported on tests on leaded glass windows conducted in England. Tests were conducted to investigate the effect of repeated booms and to...changes can cause considerable deflections in the window due to the thermal expansion of the lead. However, Pallant also found that these...RD-775-118, July , 1975. 10. Abiassi, J.J., "The Strength of Weathered Window Glass Using Surface Characteristics," Institute For Disaster Research

Flow chemistry using milli- and microstructured reactors-from conventional to novel process windows.

PubMed

Illg, Tobias; Löb, Patrick; Hessel, Volker

2010-06-01

The terminology Novel Process Window unites different methods to improve existing processes by applying unconventional and harsh process conditions like: process routes at much elevated pressure, much elevated temperature, or processing in a thermal runaway regime to achieve a significant impact on process performance. This paper is a review of parts of IMM's works in particular the applicability of above mentioned Novel Process Windows on selected chemical reactions. First, general characteristics of microreactors are discussed like excellent mass and heat transfer and improved mixing quality. Different types of reactions are presented in which the use of microstructured devices led to an increased process performance by applying Novel Process Windows. These examples were chosen to demonstrate how chemical reactions can benefit from the use of milli- and microstructured devices and how existing protocols can be changed toward process conditions hitherto not applicable in standard laboratory equipment. The used milli- and microstructured reactors can also offer advantages in other areas, for example, high-throughput screening of catalysts and better control of size distribution in a particle synthesis process by improved mixing, etc. The chemical industry is under continuous improvement. So, a lot of research is being done to synthesize high value chemicals, to optimize existing processes in view of process safety and energy consumption and to search for new routes to produce such chemicals. Leitmotifs of such undertakings are often sustainable development(1) and Green Chemistry(2).

Energy efficiency buildings program

NASA Astrophysics Data System (ADS)

1981-05-01

Progress is reported in developing techniques for auditing the energy performance of buildings. The ventilation of buildings and indoor air quality is discussed from the viewpoint of (1) combustion generated pollutants; (2) organic contaminants; (3) radon emanation, measurements, and control; (4) strategies for the field monitoring of indoor air quality; and (5) mechanical ventilation systems using air-to-air heat exchanges. The development of energy efficient windows to provide optimum daylight with minimal thermal losses in cold weather and minimum thermal gain in hot weather is considered as well as the production of high frequency solid state ballasts for fluorescent lights to provide more efficient lighting at a 25% savings over conventional core ballasts. Data compilation, analysis, and demonstration activities are summarized.

Gradient heating protocol for a diode-pumped alkali laser

NASA Astrophysics Data System (ADS)

Cai, He; Wang, You; Han, Juhong; Yu, Hang; Rong, Kepeng; Wang, Shunyan; An, Guofei; Wang, Hongyuan; Zhang, Wei; Wu, Peng; Yu, Qiang

2018-06-01

A diode-pumped alkali laser (DPAL) has gained rapid development in the recent years. Until now, the structure with single heater has been widely utilized to adjust the temperature of an alkali vapor cell in most of the literatures about DPALs. However, for an end-pumped DPAL using single heater, most pump energy is absorbed by the gain media near the entrance cell window because of the large absorption cross section of atomic alkali. As a result, the temperature in the pumping area around the entrance window will go up rapidly, especially in a case of high pumping density. The temperature rise would bring about some negative influences such as thermal effects and variations in population density. In addition, light scattering and window contamination aroused by the chemical reaction between the alkali vapor and the buffer gas will also affect the output performance of a DPAL system. To find a solution to these problems, we propose a gradient heating approach in which several heaters are tandem-set along the optical axis to anneal an alkali vapor cell. The temperature at the entrance window is adjusted to be lower than that of the other side. By using this novel scheme, one can not only achieve a homogeneous absorption of the pump energy along the cell axis, but also decrease the possibility of the window damage in a DPAL configuration. The theoretical simulation of the laser output features has been carried out for a configuration of multiple heaters. Additionally, the DPAL output performance under different gradient temperatures is also discussed in this paper. The conclusions might be helpful for development of a high-powered and high-beam-quality DPAL.

VIRTIS on Venus Express: retrieval of real surface emissivity on global scales

NASA Astrophysics Data System (ADS)

Arnold, Gabriele E.; Kappel, David; Haus, Rainer; Telléz Pedroza, Laura; Piccioni, Giuseppe; Drossart, Pierre

2015-09-01

The extraction of surface emissivity data provides the data base for surface composition analyses and enables to evaluate Venus' geology. The Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) aboard ESA's Venus Express mission measured, inter alia, the nightside thermal emission of Venus in the near infrared atmospheric windows between 1.0 and 1.2 μm. These data can be used to determine information about surface properties on global scales. This requires a sophisticated approach to understand and consider the effects and interferences of different atmospheric and surface parameters influencing the retrieved values. In the present work, results of a new technique for retrieval of the 1.0 - 1.2 μm - surface emissivity are summarized. It includes a Multi-Window Retrieval Technique, a Multi-Spectrum Retrieval technique (MSR), and a detailed reliability analysis. The MWT bases on a detailed radiative transfer model making simultaneous use of information from different atmospheric windows of an individual spectrum. MSR regularizes the retrieval by incorporating available a priori mean values, standard deviations as well as spatial-temporal correlations of parameters to be retrieved. The capability of this method is shown for a selected surface target area. Implications for geologic investigations are discussed. Based on these results, the work draws conclusions for future Venus surface composition analyses on global scales using spectral remote sensing techniques. In that context, requirements for observational scenarios and instrumental performances are investigated, and recommendations are derived to optimize spectral measurements for Venus' surface studies.

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Influence of defects on the thermal conductivity of compressed LiF

DOE PAGES

Jones, R. E.; Ward, D. K.

2018-02-08

We report defect formation in LiF, which is used as an observation window in ramp and shock experiments, has significant effects on its transmission properties. Given the extreme conditions of the experiments it is hard to measure the change in transmission directly. Using molecular dynamics, we estimate the change in conductivity as a function of the concentration of likely point and extended defects using a Green-Kubo technique with careful treatment of size effects. With this data, we form a model of the mean behavior and its estimated error; then, we use this model to predict the conductivity of a largemore » sample of defective LiF resulting from a direct simulation of ramp compression as a demonstration of the accuracy of its predictions. Given estimates of defect densities in a LiF window used in an experiment, the model can be used to correct the observations of thermal energy through the window. Also, the methodology we develop is extensible to modeling, with quantified uncertainty, the effects of a variety of defects on the thermal conductivity of solid materials.« less

Influence of defects on the thermal conductivity of compressed LiF

NASA Astrophysics Data System (ADS)

Jones, R. E.; Ward, D. K.

2018-02-01

Defect formation in LiF, which is used as an observation window in ramp and shock experiments, has significant effects on its transmission properties. Given the extreme conditions of the experiments it is hard to measure the change in transmission directly. Using molecular dynamics, we estimate the change in conductivity as a function of the concentration of likely point and extended defects using a Green-Kubo technique with careful treatment of size effects. With this data, we form a model of the mean behavior and its estimated error; then, we use this model to predict the conductivity of a large sample of defective LiF resulting from a direct simulation of ramp compression as a demonstration of the accuracy of its predictions. Given estimates of defect densities in a LiF window used in an experiment, the model can be used to correct the observations of thermal energy through the window. In addition, the methodology we develop is extensible to modeling, with quantified uncertainty, the effects of a variety of defects on the thermal conductivity of solid materials.

Distortion in the thermal noise spectrum and quality factor of nanomechanical devices due to finite frequency resolution with applications to the atomic force microscope.

PubMed

Sader, John E; Sanelli, Julian; Hughes, Barry D; Monty, Jason P; Bieske, Evan J

2011-09-01

The thermal noise spectrum of nanomechanical devices is commonly used to characterize their mechanical properties and energy dissipation. This spectrum is measured from finite time series of Brownian motion of the device, which is windowed and Fourier transformed. Here, we present a theoretical and experimental investigation of the effect of such finite sampling on the measured device quality factor. We prove that if no spectral window is used, the thermal noise spectrum retains its original Lorentzian distribution but with a reduced quality factor, indicating an apparent enhancement in energy dissipation. A simple analytical formula is derived connecting the true and measured quality factors - this enables extraction of the true device quality factor from measured data. Common windows used to reduce spectral leakage are found to distort the (true) Lorentzian shape, potentially making fitting problematic. These findings are expected to be of particular importance for devices with high quality factors, where spectral resolution can be limited in practice. Comparison and validation using measurements on atomic force microscope cantilevers are presented. © 2011 American Institute of Physics

Influence of defects on the thermal conductivity of compressed LiF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, R. E.; Ward, D. K.

We report defect formation in LiF, which is used as an observation window in ramp and shock experiments, has significant effects on its transmission properties. Given the extreme conditions of the experiments it is hard to measure the change in transmission directly. Using molecular dynamics, we estimate the change in conductivity as a function of the concentration of likely point and extended defects using a Green-Kubo technique with careful treatment of size effects. With this data, we form a model of the mean behavior and its estimated error; then, we use this model to predict the conductivity of a largemore » sample of defective LiF resulting from a direct simulation of ramp compression as a demonstration of the accuracy of its predictions. Given estimates of defect densities in a LiF window used in an experiment, the model can be used to correct the observations of thermal energy through the window. Also, the methodology we develop is extensible to modeling, with quantified uncertainty, the effects of a variety of defects on the thermal conductivity of solid materials.« less

Angular selective window systems: Assessment of technical potential for energy savings

DOE PAGES

Fernandes, Luis L.; Lee, Eleanor S.; McNeil, Andrew; ...

2014-10-16

Static angular selective shading systems block direct sunlight and admit daylight within a specific range of incident solar angles. The objective of this study is to quantify their potential to reduce energy use and peak demand in commercial buildings using state-of-the art whole-building computer simulation software that allows accurate modeling of the behavior of optically-complex fenestration systems such as angular selective systems. Three commercial systems were evaluated: a micro-perforated screen, a tubular shading structure, and an expanded metal mesh. This evaluation was performed through computer simulation for multiple climates (Chicago, Illinois and Houston, Texas), window-to-wall ratios (0.15-0.60), building codes (ASHRAEmore » 90.1-2004 and 2010) and lighting control configurations (with and without). The modeling of the optical complexity of the systems took advantage of the development of state-of-the-art versions of the EnergyPlus, Radiance and Window simulation tools. Results show significant reductions in perimeter zone energy use; the best system reached 28% and 47% savings, respectively without and with daylighting controls (ASHRAE 90.1-2004, south facade, Chicago,WWR=0.45). As a result, angular selectivity and thermal conductance of the angle-selective layer, as well as spectral selectivity of low-emissivity coatings, were identified as factors with significant impact on performance.« less

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High-temperature, high-pressure optical port for rocket engine applications

NASA Technical Reports Server (NTRS)

Delcher, Ray; Nemeth, ED; Powers, W. T.

1993-01-01

This paper discusses the design, fabrication, and test of a window assembly for instrumentation of liquid-fueled rocket engine hot gas systems. The window was designed to allow optical measurements of hot gas in the SSME fuel preburner and appears to be the first window designed for application in a rocket engine hot gas system. Such a window could allow the use of a number of remote optical measurement technologies including: Raman temperature and species concentration measurement, Raleigh temperature measurements, flame emission monitoring, flow mapping, laser-induced florescence, and hardware imaging during engine operation. The window assembly has been successfully tested to 8,000 psi at 1000 F and over 11,000 psi at room temperature. A computer stress analysis shows the window will withstand high temperature and cryogenic thermal shock.

Center for the Built Environment: Research on Building Envelope Systems

Science.gov Websites

Studies Facade and Perimeter Zone Field Study Facades and Thermal Comfort Facade Symposium Mixed-Mode Research Adaptive Comfort Model Mixed-Mode Case Studies Operable Windows and Thermal Comfort Occupant thermal preferences in naturally ventilated as sealed buildings? Case Study Research of Mixed-Mode Office

Evaluation of Building Energy Saving Through the Development of Venetian Blinds' Optimal Control Algorithm According to the Orientation and Window-to-Wall Ratio

NASA Astrophysics Data System (ADS)

Kwon, Hyuk Ju; Yeon, Sang Hun; Lee, Keum Ho; Lee, Kwang Ho

2018-02-01

As various studies focusing on building energy saving have been continuously conducted, studies utilizing renewable energy sources, instead of fossil fuel, are needed. In particular, studies regarding solar energy are being carried out in the field of building science; in order to utilize such solar energy effectively, solar radiation being brought into the indoors should be acquired and blocked properly. Blinds are a typical solar radiation control device that is capable of controlling indoor thermal and light environments. However, slat-type blinds are manually controlled, giving a negative effect on building energy saving. In this regard, studies regarding the automatic control of slat-type blinds have been carried out for the last couple of decades. Therefore, this study aims to provide preliminary data for optimal control research through the controlling of slat angle in slat-type blinds by comprehensively considering various input variables. The window area ratio and orientation were selected as input variables. It was found that an optimal control algorithm was different among each window-to-wall ratio and window orientation. In addition, through comparing and analyzing the building energy saving performance for each condition by applying the developed algorithms to simulations, up to 20.7 % energy saving was shown in the cooling period and up to 12.3 % energy saving was shown in the heating period. In addition, building energy saving effect was greater as the window area ratio increased given the same orientation, and the effects of window-to-wall ratio in the cooling period were higher than those of window-to-wall ratio in the heating period.

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Poster — Thur Eve — 22: A water calorimeter for low-energy particle beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Renaud, J; Sarfehnia, A; Seuntjens, J

2014-08-15

In this work, the feasibility of absolute dose to water measurements in low-energy electron beams using a water calorimeter specifically developed for shallow measurements is established. The calorimeter design consists of a cylindrical glass vessel encased in a block of expanded polystyrene. The vessel has a front window thickness of 1.1 mm, a 4 cm radius, and is 2.5 cm in depth. The vessel-block assembly sits inside a thermally-insulated box and is air-cooled to an operating temperature of 4 °C. Radiation-induced thermal gradients were simulated in a geometric model of the calorimeter using a finite element analysis software package. 52more » absorbed dose to water measurements were performed in a 6 and 8 MeV electron beam (z{sub max} of 1.32 and 1.76 cm, respectively) for 60 seconds at a repetition rate of 400 MU/min and an SSD of 120 cm. Within the vessel, the depth of measurement was set to 1.08 cm relative to the inner front window. The average measured dose to water was 59.6 ± 0.2 cGy/100 MU (6 MeV), and 63.7 ± 0.3 cGy/100 MU (8 MeV). The associated heat transfer corrections were determined to be 1.026 ± 0.003 and 1.017 ± 0.004 for the 6 and 8 MeV beams, respectively. The most significant source of uncertainty in this study was the repeatability (type A, 0.42%). It is expected that performing fewer consecutive measurements under higher dose rate conditions will improve the stability of the thermal background, thereby improving the repeatability and reducing the overall standard uncertainty.« less

Heat-coping strategies and bedroom thermal satisfaction in New York City.

PubMed

Lee, W Victoria; Shaman, Jeffrey

2017-01-01

There has been little research into the thermal condition of the sleeping environment. Even less well documented and understood is how the sleeping thermal environment is affected by occupant behaviors such as the use of air-conditioning (AC) and electric fans, or window operations. In this paper we present results from a questionnaire survey administered to assess summertime bedroom thermal satisfaction and heat-coping strategies among New York City (NYC) residents. Specifically, we investigated current AC usage in bedrooms and examined alternate cooling strategies, cooling appliance usage patterns, and the motivations that drove these patterns during the 2015 summer. Among survey respondents (n=706), AC was the preferred heat-coping strategy, and for 30% of respondents was the only strategy used. Electric fan use and window opening were deemed ineffective for cooling by many respondents. Indeed, less than a quarter of all respondents ever opened windows to alleviate heat in their bedrooms. In general, people utilized strategies that modify the environment more than the individual person. Unsurprisingly, the frequency and overall use of AC were significantly associated with greater bedroom thermal satisfaction; however, setting AC to a lower temperature provided no additional benefit. In contrast, more frequent use of electric fans was associated with lower thermal satisfaction. In addition, 14.7% of all respondents did not have AC in their sleeping environment and 5.8% were without any AC at home. Despite the high penetration of AC ownership, usage cost was still a major concern for most. This work contributes to a better understanding of bedtime heat-coping strategies, cooling appliance usage patterns, and associated thermal satisfaction in NYC. The findings of this study suggest resident AC usage patterns may not be optimized for thermal satisfaction. Potential alternative cooling approaches could be explored to better balance maximizing thermal comfort while reducing energy consumption and environmental impact. Copyright © 2016 Elsevier B.V. All rights reserved.

A Comparison of Photo-Induced Hysteresis Between Hydrogenated Amorphous Silicon and Amorphous IGZO Thin-Film Transistors.

PubMed

Ha, Tae-Jun; Cho, Won-Ju; Chung, Hong-Bay; Koo, Sang-Mo

2015-09-01

We investigate photo-induced instability in thin-film transistors (TFTs) consisting of amorphous indium-gallium-zinc-oxide (a-IGZO) as active semiconducting layers by comparing with hydrogenated amorphous silicon (a-Si:H). An a-IGZO TFT exhibits a large hysteresis window in the illuminated measuring condition but no hysteresis window in the dark condition. On the contrary, a large hysteresis window measured in the dark condition in a-Si:H was not observed in the illuminated condition. Even though such materials possess the structure of amorphous phase, optical responses or photo instability in TFTs looks different from each other. Photo-induced hysteresis results from initially trapped charges at the interface between semiconductor and dielectric films or in the gate dielectric which possess absorption energy to interact with deep trap-states and affect the movement of Fermi energy level. In order to support our claim, we also perform CV characteristics in photo-induced hysteresis and demonstrate thermal-activated hysteresis. We believe that this work can provide important information to understand different material systems for optical engineering which includes charge transport and band transition.

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"TPSX: Thermal Protection System Expert and Material Property Database"

NASA Technical Reports Server (NTRS)

Squire, Thomas H.; Milos, Frank S.; Rasky, Daniel J. (Technical Monitor)

1997-01-01

The Thermal Protection Branch at NASA Ames Research Center has developed a computer program for storing, organizing, and accessing information about thermal protection materials. The program, called Thermal Protection Systems Expert and Material Property Database, or TPSX, is available for the Microsoft Windows operating system. An "on-line" version is also accessible on the World Wide Web. TPSX is designed to be a high-quality source for TPS material properties presented in a convenient, easily accessible form for use by engineers and researchers in the field of high-speed vehicle design. Data can be displayed and printed in several formats. An information window displays a brief description of the material with properties at standard pressure and temperature. A spread sheet window displays complete, detailed property information. Properties which are a function of temperature and/or pressure can be displayed as graphs. In any display the data can be converted from English to SI units with the click of a button. Two material databases included with TPSX are: 1) materials used and/or developed by the Thermal Protection Branch at NASA Ames Research Center, and 2) a database compiled by NASA Johnson Space Center 9JSC). The Ames database contains over 60 advanced TPS materials including flexible blankets, rigid ceramic tiles, and ultra-high temperature ceramics. The JSC database contains over 130 insulative and structural materials. The Ames database is periodically updated and expanded as required to include newly developed materials and material property refinements.

STS-114 Flight Director Press Conference, PAO Support

NASA Image and Video Library

2005-08-04

JSC2005-E-32511 (4 August 2005) --- One of four visual aids used by Shuttle Deputy Program Manager Wayne Hale during an August 4 press conference that dealt with important tests in wind tunnels at NASA's Ames Research Center. Engineers simulated the conditions of the Space Shuttle Discovery for a disrupted thermal blanket near the commander's window on the forward cabin of the spacecraft. Eventually it was decided that no additonal spacewalk work needed to be performed to fix the blanket.

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Energy performance analysis of a detached single-family house to be refurbished

NASA Astrophysics Data System (ADS)

Aleixo, Kevin; Curado, António

2017-07-01

This study was developed with the purpose of analyzing the reinforcement of the energy performance in a detached single-family house to be refurbished, using this building as a case-study for simulation and experimental analysis. The building is located in Viana do Castelo, a city in the northwest of Portugal nearby the Atlantic Ocean. The developed study was carried out in order to characterize the thermal performance of the house, using simulation analysis in a dynamic regime. The energy consumption study was developed in permanent regime analysis, using simulation tools. At the end, the study aimed to propose and define the best retrofitting solutions, both passive and active, and to improve the energy performance of the building. The outcomes of the study provided the importance of passive retrofitting solutions on thermal comfort and energy performance. The use of a set of thermal solutions, as the insulation of the roof, walls and the windows, it is possible to achieve a global gain of 0, 63 °C and to reduce energy consumption in 61, 46 [kWh/m2.year]. The study of the building in a simplified thermal regime, according to the Portuguese energy efficiency regulation, allowed the determination of the energy efficiency class of the house and retrofitting solutions proposed. The initial energy performance class of the building is C. With the application of a passive set of solutions, it's possible to improve the energy performance to a class B. With the implementation of some active solutions, it is possible to reach an energy class A +.

Optimization of Dish Solar Collectors with and without Secondary Concentrators

NASA Technical Reports Server (NTRS)

Jaffe, L. D.

1982-01-01

Methods for optimizing parabolic dish solar collectors and the consequent effects of various optical, thermal, mechanical, and cost variables are examined. The most important performance optimization is adjusting the receiver aperture to maximize collector efficiency. Other parameters that can be adjusted to optimize efficiency include focal length, and, if a heat engine is used, the receiver temperature. The efficiency maxima associated with focal length and receiver temperature are relatively broad; it may, accordingly, be desirable to design somewhat away from the maxima. Performance optimization is sensitive to the slope and specularity errors of the concentrator. Other optical and thermal variables affecting optimization are the reflectance and blocking factor of the concentrator, the absorptance and losses of the receiver, and, if a heat engine is used, the shape of the engine efficiency versus temperature curve. Performance may sometimes be improved by use of an additional optical element (a secondary concentrator) or a receiver window if the errors of the primary concentrator are large or the receiver temperature is high.

Solar Heat Gain Coefficient (SHGC) | Efficient Windows Collaborative

Science.gov Websites

Foundry Foundry New Construction Windows Window Selection Tool Selection Process Design Guidance Installation Replacement Windows Window Selection Tool Assessing Options Selection Process Design Guidance Installation Understanding Windows Benefits Design Considerations Measuring Performance Performance Standards

Proton irradiation damage of an annealed Alloy 718 beam window

DOE PAGES

Bach, H. T.; Anderoglu, O.; Saleh, T. A.; ...

2015-04-01

Mechanical testing and microstructural analysis was performed on an Alloy 718 window that was in use at the Los Alamos Neutron Science Center (LANSCE) Isotope Production Facility (IPF) for approximately 5 years. It was replaced as part of the IPF preventive maintenance program. The window was transported to the Wing 9 hot cells at the Chemical and Metallurgical Research (CMR) LANL facility, visually inspected and 3-mm diameter samples were trepanned from the window for mechanical testing and microstructural analysis. Shear punch testing and optical metallography was performed at the CMR hot cells. The 1-mm diameter shear punch disks were cutmore » into smaller samples to further reduce radiation exposure dose rate using Focus Ion Beam (FIB) and microstructure changes were analyzed using a Transmission Electron Microscopy (TEM). Irradiation doses were determined to be ~0.2–0.7 dpa (edge) to 11.3 dpa (peak of beam intensity) using autoradiography and MCNPX calculations. The corresponding irradiation temperatures were calculated to be ~34–120 °C with short excursion to be ~47–220 °C using ANSYS. Mechanical properties and microstructure analysis results with respect to calculated dpa and temperatures show that significant work hardening occurs but useful ductility still remains. The hardening in the lowest dose region (~0.2–0.7 dpa) was the highest and attributed to the formation of γ" precipitates and irradiation defect clusters/bubbles whereas the hardening in the highest dose region (~11.3 dpa) was lower and attributed mainly to irradiation defect clusters and some thermal annealing.« less

Performance Optimization of the Gasdynamic Mirror Propulsion System

NASA Technical Reports Server (NTRS)

Emrich, William J., Jr.; Kammash, Terry

1999-01-01

Nuclear fusion appears to be a most promising concept for producing extremely high specific impulse rocket engines. Engines such as these would effectively open up the solar system to human exploration and would virtually eliminate launch window restrictions. A preliminary vehicle sizing and mission study was performed based on the conceptual design of a Gasdynamic Mirror (GDM) fusion propulsion system. This study indicated that the potential specific impulse for this engine is approximately 142,000 sec. with about 22,100 N of thrust using a deuterium-tritium fuel cycle. The engine weight inclusive of the power conversion system was optimized around an allowable engine mass of 1500 Mg assuming advanced superconducting magnets and a Field Reversed Configuration (FRC) end plug at the mirrors. The vehicle habitat, lander, and structural weights are based on a NASA Mars mission study which assumes the use of nuclear thermal propulsion' Several manned missions to various planets were analyzed to determine fuel requirements and launch windows. For all fusion propulsion cases studied, the fuel weight remained a minor component of the total system weight regardless of when the missions commenced. In other words, the use of fusion propulsion virtually eliminates all mission window constraints and effectively allows unlimited manned exploration of the entire solar system. It also mitigates the need to have a large space infrastructure which would be required to support the transfer of massive amounts of fuel and supplies to lower a performing spacecraft.

Design of the beryllium window for Brookhaven Linac Isotope Producer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nayak, S.; Mapes, M.; Raparia, D.

2015-11-01

In the Brookhaven Linac Isotope Producer (BLIP) beam line, there were two Beryllium (Be) windows with an air gap to separate the high vacuum upstream side from low vacuum downstream side. There had been frequent window failures in the past which affected the machine productivity and increased the radiation dose received by workers due to unplanned maintenance. To improve the window life, design of Be window is reexamined. Detailed structural and thermal simulations are carried out on Be window for different design parameters and loading conditions to come up with better design to improve the window life. The new designmore » removed the air gap and connect the both beam lines with a Be window in-between. The new design has multiple advantages such as 1) reduces the beam energy loss (because of one window with no air gap), 2) reduces air activation due to nuclear radiation and 3) increased the machine reliability as there is no direct pressure load during operation. For quick replacement of this window, an aluminum bellow coupled with load binder was designed. There hasn’t been a single window failure since the new design was implemented in 2012.« less

The opto-cryo-mechanical design of the short wavelength camera for the CCAT Observatory

NASA Astrophysics Data System (ADS)

Parshley, Stephen C.; Adams, Joseph; Nikola, Thomas; Stacey, Gordon J.

2014-07-01

The CCAT observatory is a 25-m class Gregorian telescope designed for submillimeter observations that will be deployed at Cerro Chajnantor (~5600 m) in the high Atacama Desert region of Chile. The Short Wavelength Camera (SWCam) for CCAT is an integral part of the observatory, enabling the study of star formation at high and low redshifts. SWCam will be a facility instrument, available at first light and operating in the telluric windows at wavelengths of 350, 450, and 850 μm. In order to trace the large curvature of the CCAT focal plane, and to suit the available instrument space, SWCam is divided into seven sub-cameras, each configured to a particular telluric window. A fully refractive optical design in each sub-camera will produce diffraction-limited images. The material of choice for the optical elements is silicon, due to its excellent transmission in the submillimeter and its high index of refraction, enabling thin lenses of a given power. The cryostat's vacuum windows double as the sub-cameras' field lenses and are ~30 cm in diameter. The other lenses are mounted at 4 K. The sub-cameras will share a single cryostat providing thermal intercepts at 80, 15, 4, 1 and 0.1 K, with cooling provided by pulse tube cryocoolers and a dilution refrigerator. The use of the intermediate temperature stage at 15 K minimizes the load at 4 K and reduces operating costs. We discuss our design requirements, specifications, key elements and expected performance of the optical, thermal and mechanical design for the short wavelength camera for CCAT.

Life test results for an ensemble of CO2 lasers

NASA Technical Reports Server (NTRS)

Peruso, C. J.; Degnan, J. J.; Hochuli, U. E.

1978-01-01

The effects of cathode material, cathode operating temperature, anode configuration, window materials, and hydrogen additives on laser lifetime are determined. Internally oxidized copper and silber-copper alloy cathodes were tested. The cathode operating temperature was raised in some tubes through the use of thermal insulation. Lasers incorporating thermally insulated silver copper oxide cathodes clearly yielded the longest lifetimes-typically in excess of 22,000 hours. The use of platinum sheet versus platinum pin anodes had no observable effect on laser lifetime. Similarly, the choice of germanium, cadmium telluride, or zinc selenide as the optical window material appears to have no impact on lifetime.

Micro-machined thermo-conductivity detector

DOEpatents

Yu, Conrad

2003-01-01

A micro-machined thermal conductivity detector for a portable gas chromatograph. The detector is highly sensitive and has fast response time to enable detection of the small size gas samples in a portable gas chromatograph which are in the order of nanoliters. The high sensitivity and fast response time are achieved through micro-machined devices composed of a nickel wire, for example, on a silicon nitride window formed in a silicon member and about a millimeter square in size. In addition to operating as a thermal conductivity detector, the silicon nitride window with a micro-machined wire therein of the device can be utilized for a fast response heater for PCR applications.

Highly Safe Ionic Liquid Electrolytes for Sodium-Ion Battery: Wide Electrochemical Window and Good Thermal Stability.

PubMed

Wu, Feng; Zhu, Na; Bai, Ying; Liu, Libin; Zhou, Hang; Wu, Chuan

2016-08-24

Novel ionic liquid (IL) electrolytes are prepared by mixing 1-ethyl-3-methylimidazolium-bis-tetrafluoroborate (EMIBF4) with different concentrations of sodium salt (NaBF4). The as-prepared IL electrolytes display wide electrochemical windows of ∼4 V (1-5 V), which are consistent with the quantum chemical theoretical calculation. The IL electrolyte with 0.1 M NaBF4 shows excellent ionic conductivity, namely, 9.833 × 10(-3) S cm(-1) at 20 °C. In addition, nonflammability and good thermal stability are exhibited by combustion test and thermogravimetric analysis (TGA), which indicate the high safety of the IL electrolyte.

Comparative burial and thermal history of lower Upper Cretaceous strata, Powder River basin, Wyoming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuccio, V.F.

1989-03-01

Burial histories were reconstructed for three localities in the Powder River basin (PRB), Wyoming. Thermal maturity of lower Upper Cretaceous source rocks was determined by vitrinite reflectance (R/sub m/) and time-temperature index (TTI) modeling, producing independent estimates for timing of the oil window (0.55-1.35% R/sub m/). In the northwestern PRB, lower Upper Cretaceous rocks were buried to about 12,500 ft and achieved a thermal maturity of 0.50% to 0.56% at maximum burial, 10 Ma, based on measured R/sub m/. TTI modeling suggests a slightly higher thermal maturity, with an R/sub m/ equivalent of approximately 0.75%, placing the source rocks atmore » the beginning of the oil window 30 Ma. In the southwestern PRB, lower Upper Cretaceous rocks have been buried to about 15,000 ft and achieved thermal maturities between 0.66% and 0.75% about 10 Ma based on measured R/sub m/; therefore, petroleum generation may have begun slightly earlier. TTI modeling estimates an R/sub m/ equivalent of 1.10%, placing the beginning of the oil window at 45 Ma. In the northeastern PRB, lower Upper Cretaceous rocks have been buried only to approximately 5500 ft. Measured R/sub m/ and TTI modeling indicate a thermal maturity for lower Upper Cretaceous rocks between 0.45% and 0.50% R/sub m/, too low for petroleum generation. The higher R/sub m/ values determined by the TTI models may be due to overestimation of maximum burial depth and/or paleogeothermal gradients. The two independent maturity indicators do, however, constrain fairly narrowly the onset of petroleum generation.« less

Study of wavefront error and polarization of a side mounted infrared window

NASA Astrophysics Data System (ADS)

Liu, Jiaguo; Li, Lin; Hu, Xinqi; Yu, Xin

2008-03-01

The wavefront error and polarization of a side mounted infrared window made of ZnS are studied. The Infrared windows suffer from temperature gradient and stress during their launch process. Generally, the gradient in temperature changes the refractive index of the material whereas stress produces deformation and birefringence. In this paper, a thermal finite element analysis (FEA) of an IR window is presented. For this purpose, we employed an FEA program Ansys to obtain the time-varying temperature field. The deformation and stress of the window are derived from a structural FEA with the aerodynamic force and the temperature field previously obtained as being the loads. The deformation, temperature field, stress field, ray tracing and Jones Calculus are used to calculate the wavefront error and the change of polarization state.

Creep analysis of solid oxide fuel cell with bonded compliant seal design

NASA Astrophysics Data System (ADS)

Jiang, Wenchun; Zhang, Yucai; Luo, Yun; Gong, J. M.; Tu, S. T.

2013-12-01

Solid oxide fuel cell (SOFC) requires good sealant because it works in harsh conditions (high temperature, thermal cycle, oxidative and reducing gas environments). Bonded compliant seal (BCS) is a new sealing method for planar SOFC. It uses a thin foil metal to bond the window frame and cell, achieving the seal between window frame and cell. At high temperature, a comprehensive evaluation of its creep strength is essential for the adoption of BCS design. In order to characterize the creep behavior, the creep induced by thermal stresses in SOFC with BCS design is simulated by finite element method. The results show that the foil is compressed and large thermal stresses are generated. The initial peak thermal stress is located in the thin foil because the foil acts as a spring stores the thermal stresses by elastic and plastic deformation in itself. Serving at high temperature, initial thermal displacement is partially recovered because of the creep relaxation, which becomes a new discovered advantage for BCS design. It predicts that the failures are likely to happen in the middle of the cell edge and BNi-2 filler metal, because the maximum residual displacement and creep strain are located.

Rapidity window dependences of higher order cumulants and diffusion master equation

NASA Astrophysics Data System (ADS)

Kitazawa, Masakiyo

2015-10-01

We study the rapidity window dependences of higher order cumulants of conserved charges observed in relativistic heavy ion collisions. The time evolution and the rapidity window dependence of the non-Gaussian fluctuations are described by the diffusion master equation. Analytic formulas for the time evolution of cumulants in a rapidity window are obtained for arbitrary initial conditions. We discuss that the rapidity window dependences of the non-Gaussian cumulants have characteristic structures reflecting the non-equilibrium property of fluctuations, which can be observed in relativistic heavy ion collisions with the present detectors. It is argued that various information on the thermal and transport properties of the hot medium can be revealed experimentally by the study of the rapidity window dependences, especially by the combined use, of the higher order cumulants. Formulas of higher order cumulants for a probability distribution composed of sub-probabilities, which are useful for various studies of non-Gaussian cumulants, are also presented.

The Zwicky Transient Facility Camera

NASA Astrophysics Data System (ADS)

Dekany, Richard; Smith, Roger M.; Belicki, Justin; Delacroix, Alexandre; Duggan, Gina; Feeney, Michael; Hale, David; Kaye, Stephen; Milburn, Jennifer; Murphy, Patrick; Porter, Michael; Reiley, Daniel J.; Riddle, Reed L.; Rodriguez, Hector; Bellm, Eric C.

2016-08-01

The Zwicky Transient Facility Camera (ZTFC) is a key element of the ZTF Observing System, the integrated system of optoelectromechanical instrumentation tasked to acquire the wide-field, high-cadence time-domain astronomical data at the heart of the Zwicky Transient Facility. The ZTFC consists of a compact cryostat with large vacuum window protecting a mosaic of 16 large, wafer-scale science CCDs and 4 smaller guide/focus CCDs, a sophisticated vacuum interface board which carries data as electrical signals out of the cryostat, an electromechanical window frame for securing externally inserted optical filter selections, and associated cryo-thermal/vacuum system support elements. The ZTFC provides an instantaneous 47 deg2 field of view, limited by primary mirror vignetting in its Schmidt telescope prime focus configuration. We report here on the design and performance of the ZTF CCD camera cryostat and report results from extensive Joule-Thompson cryocooler tests that may be of broad interest to the instrumentation community.

Digitized detection of gamma-ray signals concentrated in narrow time windows for transient positron annihilation lifetime spectroscopy

NASA Astrophysics Data System (ADS)

Kinomura, A.; Suzuki, R.; Oshima, N.; O'Rourke, B. E.; Nishijima, T.; Ogawa, H.

2014-12-01

A pulsed slow-positron beam generated by an electron linear accelerator was directly used for positron annihilation lifetime spectroscopy without any positron storage devices. A waveform digitizer was introduced to simultaneously capture multiple gamma-ray signals originating from positron annihilation events during a single accelerator pulse. The positron pulse was chopped and bunched with the chopper signals also sent to the waveform digitizer. Time differences between the annihilation gamma-ray and chopper peaks were calculated and accumulated as lifetime spectra in a computer. The developed technique indicated that positron annihilation lifetime spectroscopy can be performed in a 20 μs time window at a pulse repetition rate synchronous with the linear accelerator. Lifetime spectra of a Kapton sheet and a thermally grown SiO2 layer on Si were successfully measured. Synchronization of positron lifetime measurements with pulsed ion irradiation was demonstrated by this technique.

Innovative on-chip packaging applied to uncooled IRFPA

NASA Astrophysics Data System (ADS)

Dumont, Geoffroy; Arnaud, Agnès; Imperinetti, Pierre; Mottin, Eric; Simoens, François; Vialle, Claire; Rabaud, Wilfried; Grand, Gilles; Baclet, Nathalie

2008-03-01

The Laboratoire Infrarouge (LIR) of the Laboratoire d'Electronique et de Technologie de l'Information (LETI) has been involved in the development of microbolometers for over fifteen years. Two generations of technology have been transferred to ULIS and LETI is still working to improve performances of low cost detectors. Simultaneously, packaging still represents a significant part of detectors price. Reducing production costs would contribute to keep on extending applications of uncooled IRFPA to high volume markets like automotive. Therefore LETI develops an onchip packaging technology dedicated to microbolometers. The efficiency of a micropackaging technology for microbolometers relies on two major technical specifications. First, it must include an optical window with a high transmittance for the IR band, so as to maximize the detector absorption. Secondly, in order to preserve the thermal insulation of the detector, the micropackaging must be hermetically closed to maintain a vacuum level lower than 10 -3mbar. This paper presents an original microcap structure that enables the use of IR window materials as sealing layers to maintain the expected vacuum level. The modelling and integration of an IR window suitable for this structure is also presented. This zero level packaging technology is performed in a standard collective way, in continuation of bolometers' technology. The CEA-LETI, MINATEC presents status of these developments concerning this innovating technology including optical simulations results and SEM views of technical realizations.

Design Performance of Front Steering-Type Electron Cyclotron Launcher for ITER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahashi, K.; Imai, T.; Kobayashi, N.

2005-01-15

The performance of a front steering (FS)-type electron cyclotron launcher designed for the International Thermonuclear Experimental Reactor (ITER) is evaluated with a thermal, electromagnetic, and nuclear analysis of the components; a mechanical test of a spiral tube for the steering mirror; and a rotational test of bearings. The launcher consists of a front shield and a launcher plug where three movable optic mirrors to steer incident multimegawatt radio-frequency beam power, waveguide components, nuclear shields, and vacuum windows are installed. The windows are located behind a closure plate to isolate the transmission lines from the radioactivated circumstance (vacuum vessel). The waveguidemore » lines of the launcher are doglegged to reduce the direct neutron streaming toward the vacuum windows and other components. The maximum stresses on the critical components such as the steering mirror, its cooling tube, and the front shield are less than their allowable stresses. It was also identified that the stress on the launcher, which yielded from electromagnetic force caused by plasma disruption, was a little larger than the criteria, and a modification of the launcher plug structure was necessary. The nuclear analysis result shows that the neutron shield capability of the launcher satisfies the shield criteria of the ITER. It concludes that the design of the FS launcher is generally suitable for application to the ITER.« less

Evaluation of solar gain through skylights for inclusion in the SP53 residential building loads data base

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanford, J.W.; Huang, Y.J.

The energy performance of skylights is similar to that of windows in admitting solar heat gain, while at the same time providing a pathway for convective and conductive heat transfer through the building envelope. Since skylights are typically installed at angles ranging from 0{degrees} to 45{degrees}, and differ from windows in both their construction and operation, their conductive and convective heat gains or losses, as well as solar heat gain, will differ for the same rough opening and thermal characteristics. The objective of this work is to quantify the impact of solar gain through skylights on building heating and coolingmore » loads in 45 climates, and to develop a method for including these data into the SP53 residential loads data base previously developed by LBL in support of DOE`s Automated Residential Energy Standard (ARES) program. The authors used the DOE-2.1C program to simulate the heating and cooling loads of a prototypical residential building while varying the size and solar characteristics of skylights and windows. The results are presented as Skylight Solar Loads, which are the contribution of solar gains through skylights to the overall building heating and cooling loads, and as Skylight Solar Load Ratios, which are the ratios of skylight solar loads to those for windows with the same orientation. The study shows that skylight solar loads are larger than those for windows in both heating and cooling. Skylight solar cooling loads are from three to four times greater than those for windows regardless of the skylight tilt, except for those facing north. These cooling loads are largest for south-facing skylights at a tilt angle of approximately 20{degrees}, and drop off at higher tilts and other orientations.« less

Simulation of thermal environment in a three-layer vinyl greenhouse by natural ventilation control

NASA Astrophysics Data System (ADS)

Jin, Tea-Hwan; Shin, Ki-Yeol; Yoon, Si-Won; Im, Yong-Hoon; Chang, Ki-Chang

2017-11-01

A high energy, efficient, harmonious, ecological greenhouse has been highlighted by advanced future agricultural technology recently. This greenhouse is essential for expanding the production cycle toward growth conditions through combined thermal environmental control. However, it has a negative effect on farming income via huge energy supply expenses. Because not only production income, but operating costs related to thermal load for thermal environment control is important in farming income, it needs studies such as a harmonious ecological greenhouse using natural ventilation control. This study is simulated for energy consumption and thermal environmental conditions in a three-layered greenhouse by natural ventilation using window opening. A virtual 3D model of a three-layered greenhouse was designed based on the real one in the Gangneung area. This 3D model was used to calculate a thermal environment state such as indoor temperature, relative humidity, and thermal load in the case of a window opening rate from 0 to 100%. There was also a heat exchange operated for heating or cooling controlled by various setting temperatures. The results show that the cooling load can be reduced by natural ventilation control in the summer season, and the heat exchange capacity for heating can also be simulated for growth conditions in the winter season.

The Significance of Temperature Based Approach Over the Energy Based Approaches in the Buildings Thermal Assessment

NASA Astrophysics Data System (ADS)

Albatayneh, Aiman; Alterman, Dariusz; Page, Adrian; Moghtaderi, Behdad

2017-05-01

The design of low energy buildings requires accurate thermal simulation software to assess the heating and cooling loads. Such designs should sustain thermal comfort for occupants and promote less energy usage over the life time of any building. One of the house energy rating used in Australia is AccuRate, star rating tool to assess and compare the thermal performance of various buildings where the heating and cooling loads are calculated based on fixed operational temperatures between 20 °C to 25 °C to sustain thermal comfort for the occupants. However, these fixed settings for the time and temperatures considerably increase the heating and cooling loads. On the other hand the adaptive thermal model applies a broader range of weather conditions, interacts with the occupants and promotes low energy solutions to maintain thermal comfort. This can be achieved by natural ventilation (opening window/doors), suitable clothes, shading and low energy heating/cooling solutions for the occupied spaces (rooms). These activities will save significant amount of operating energy what can to be taken into account to predict energy consumption for a building. Most of the buildings thermal assessment tools depend on energy-based approaches to predict the thermal performance of any building e.g. AccuRate in Australia. This approach encourages the use of energy to maintain thermal comfort. This paper describes the advantages of a temperature-based approach to assess the building's thermal performance (using an adaptive thermal comfort model) over energy based approach (AccuRate Software used in Australia). The temperature-based approach was validated and compared with the energy-based approach using four full scale housing test modules located in Newcastle, Australia (Cavity Brick (CB), Insulated Cavity Brick (InsCB), Insulated Brick Veneer (InsBV) and Insulated Reverse Brick Veneer (InsRBV)) subjected to a range of seasonal conditions in a moderate climate. The time required for heating and/or cooling using the adaptive thermal comfort approach and AccuRate predictions were estimated. Significant savings (of about 50 %) in energy consumption in minimising the time required for heating and cooling were achieved by using the adaptive thermal comfort model.

Spectral definition of the ArTeMiS instrument

NASA Astrophysics Data System (ADS)

Haynes, Vic; Maffei, Bruno; Pisano, Giampaolo; Dubreuil, Didier; Delisle, Cyrille; Le Pennec, Jean; Hurtado, Norma

2014-07-01

ArTeMiS is a sub-millimetre camera to be operated, on the Atacama Pathfinder Experiment Telescope (APEX). The ultimate goal is to observe simultaneously in three atmospheric spectral windows in the region of 200, 350 and 450 microns. We present the filtering scheme, which includes the cryostat window, thermal rejection elements, band separation and spectral isolation, which has been adopted for this instrument. This was achieved using a combination of scattering, Yoshinaga filters, organic dyes and Ulrich type embedded metallic mesh devices. Design of the quasi-optical mesh components has been developed by modelling with an in-house developed code. For the band separating dichroics, which are used with an incidence angle of 35 deg, further modelling has been performed with HFSS (Ansoft). Spectral characterization of the components for the 350 and 450 bands have been performed with a Martin-Puplett Polarizing Fourier Transform Spectrometer. While for the first commissioning and observation campaign, one spectral band only was operational (350 microns), we report on the design of the 200, 350 and 450 micron bands.

Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Horizontal Window Frames with Internal Cavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsen, Arlid; Kohler, Christian; Dalehaug, Arvid

2008-12-01

This paper assesses the accuracy of the simplified frame cavity conduction/convection and radiation models presented in ISO 15099 and used in software for rating and labeling window products. Temperatures and U-factors for typical horizontal window frames with internal cavities are compared; results from Computational Fluid Dynamics (CFD) simulations with detailed radiation modeling are used as a reference. Four different frames were studied. Two were made of polyvinyl chloride (PVC) and two of aluminum. For each frame, six different simulations were performed, two with a CFD code and four with a building-component thermal-simulation tool using the Finite Element Method (FEM). Thismore » FEM tool addresses convection using correlations from ISO 15099; it addressed radiation with either correlations from ISO 15099 or with a detailed, view-factor-based radiation model. Calculations were performed using the CFD code with and without fluid flow in the window frame cavities; the calculations without fluid flow were performed to verify that the CFD code and the building-component thermal-simulation tool produced consistent results. With the FEM-code, the practice of subdividing small frame cavities was examined, in some cases not subdividing, in some cases subdividing cavities with interconnections smaller than five millimeters (mm) (ISO 15099) and in some cases subdividing cavities with interconnections smaller than seven mm (a breakpoint that has been suggested in other studies). For the various frames, the calculated U-factors were found to be quite comparable (the maximum difference between the reference CFD simulation and the other simulations was found to be 13.2 percent). A maximum difference of 8.5 percent was found between the CFD simulation and the FEM simulation using ISO 15099 procedures. The ISO 15099 correlation works best for frames with high U-factors. For more efficient frames, the relative differences among various simulations are larger. Temperature was also compared, at selected locations on the frames. Small differences was found in the results from model to model. Finally, the effectiveness of the ISO cavity radiation algorithms was examined by comparing results from these algorithms to detailed radiation calculations (from both programs). Our results suggest that improvements in cavity heat transfer calculations can be obtained by using detailed radiation modeling (i.e. view-factor or ray-tracing models), and that incorporation of these strategies may be more important for improving the accuracy of results than the use of CFD modeling for horizontal cavities.« less

Mickey Leland Energy Fellowship Report: Development of Advanced Window Coatings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolton, Ladena A.; Alvine, Kyle J.; Schemer-Kohrn, Alan L.

2014-08-05

Advanced fenestration technologies for light and thermal management in building applications are of great recent research interest for improvements in energy efficiency. Of these technologies, there is specific interest in advanced window coating technologies that have tailored control over the visible and infrared (IR) scattering into a room for both static and dynamic applications. Recently, PNNL has investigated novel subwavelength nanostructured coatings for both daylighting, and IR thermal management applications. Such coatings rese still in the early stages and additional research is needed in terms of scalable manufacturing. This project investigates aspects of a potential new methodology for low-cost scalablemore » manufacture of said subwavelength coatings.« less

HVI Ballistic Limit Characterization of Fused Silica Thermal Panes

NASA Technical Reports Server (NTRS)

Miller, J. E.; Bohl, W. D.; Christiansen, E. L.; Davis, B. A.; Deighton, K. D.

2015-01-01

Fused silica window systems are used heavily on crewed reentry vehicles, and they are currently being used on the next generation of US crewed spacecraft, Orion. These systems improve crew situational awareness and comfort, as well as, insulating the reentry critical components of a spacecraft against the intense thermal environments of atmospheric reentry. Additionally, these materials are highly exposed to space environment hazards like solid particle impacts. This paper discusses impact studies up to 10 km/s on a fused silica window system proposed for the Orion spacecraft. A ballistic limit equation that describes the threshold of perforation of a fuse silica pane over a broad range of impact velocities, obliquities and projectile materials is discussed here.

Finite element model of thermal processes in retinal photocoagulation

NASA Astrophysics Data System (ADS)

Sramek, Christopher; Paulus, Yannis M.; Nomoto, Hiroyuki; Huie, Phil; Palanker, Daniel

2009-02-01

Short duration (< 20 ms) pulses are desirable in patterned scanning laser photocoagulation to confine thermal damage to the photoreceptor layer, decrease overall treatment time and reduce pain. However, short exposures have a smaller therapeutic window (defined as the ratio of rupture threshold power to that of light coagulation). We have constructed a finite-element computational model of retinal photocoagulation to predict spatial damage and improve the therapeutic window. Model parameters were inferred from experimentally measured absorption characteristics of ocular tissues, as well as the thresholds of vaporization, coagulation, and retinal pigment epithelial (RPE) damage. Calculated lesion diameters showed good agreement with histological measurements over a wide range of pulse durations and powers.

Application of split window technique to TIMS data

NASA Technical Reports Server (NTRS)

Matsunaga, Tsuneo; Rokugawa, Shuichi; Ishii, Yoshinori

1992-01-01

Absorptions by the atmosphere in thermal infrared region are mainly due to water vapor, carbon dioxide, and ozone. As the content of water vapor in the atmosphere greatly changes according to weather conditions, it is important to know its amount between the sensor and the ground for atmospheric corrections of thermal Infrared Multispectral Scanner (TIMS) data (i.e. radiosonde). On the other hand, various atmospheric correction techniques were already developed for sea surface temperature estimations from satellites. Among such techniques, Split Window technique, now widely used for AVHRR (Advanced Very High Resolution Radiometer), uses no radiosonde or any kind of supplementary data but a difference between observed brightness temperatures in two channels for estimating atmospheric effects. Applications of Split Window technique to TIMS data are discussed because availability of atmospheric profile data is not clear when ASTER operates. After these theoretical discussions, the technique is experimentally applied to TIMS data at three ground targets and results are compared with atmospherically corrected data using LOWTRAN 7 with radiosonde data.

Evolution of oxygenated cadmium sulfide (CdS:O) during high-temperature CdTe solar cell fabrication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meysing, Daniel M.; Reese, Matthew O.; Warren, Charles W.

Oxygenated cadmium sulfide (CdS:O) produced by reactive sputtering has emerged as a promising alternative to conventional CdS for use as the n-type window layer in CdTe solar cells. Here, complementary techniques are used to expose the window layer (CdS or CdS:O) in completed superstrate devices and combined with a suite of materials characterization to elucidate its evolution during high temperature device processing. During device fabrication amorphous CdS:O undergoes significant interdiffusion with CdTe and recrystallization, forming CdS1-yTey nanocrystals whose Te fraction approaches solubility limits. Significant oxygen remains after processing, concentrated in sulfate clusters dispersed among the CdS1-yTey alloy phase, accounting formore » ~30% of the post-processed window layer based on cross-sectional microscopy. Interdiffusion and recrystallization are observed in devices with un-oxygenated CdS, but to a much lesser extent. Etching experiments suggest that the CdS thickness is minimally changed during processing, but the CdS:O window layer is reduced from 100 nm to 60-80 nm, which is confirmed by microscopy. Alloying reduces the band gap of the CdS:O window layer to 2.15 eV, but reductions in thickness and areal density improve its transmission spectrum, which is well matched to device quantum efficiency. The changes to the window layer in the reactive environments of device fabrication are profoundly different than what occurs by thermal annealing in an inert environment, which produced films with a band gap of 2.4 eV for both CdS and CdS:O. These results illustrate for the first time the significant changes that occur to the window layer during processing that are critical to the performance of CdTe solar cells.« less

Computed Tomography Window Blending: Feasibility in Thoracic Trauma.

PubMed

Mandell, Jacob C; Wortman, Jeremy R; Rocha, Tatiana C; Folio, Les R; Andriole, Katherine P; Khurana, Bharti

2018-02-07

This study aims to demonstrate the feasibility of processing computed tomography (CT) images with a custom window blending algorithm that combines soft-tissue, bone, and lung window settings into a single image; to compare the time for interpretation of chest CT for thoracic trauma with window blending and conventional window settings; and to assess diagnostic performance of both techniques. Adobe Photoshop was scripted to process axial DICOM images from retrospective contrast-enhanced chest CTs performed for trauma with a window-blending algorithm. Two emergency radiologists independently interpreted the axial images from 103 chest CTs with both blended and conventional windows. Interpretation time and diagnostic performance were compared with Wilcoxon signed-rank test and McNemar test, respectively. Agreement with Nexus CT Chest injury severity was assessed with the weighted kappa statistic. A total of 13,295 images were processed without error. Interpretation was faster with window blending, resulting in a 20.3% time saving (P < .001), with no difference in diagnostic performance, within the power of the study to detect a difference in sensitivity of 5% as determined by post hoc power analysis. The sensitivity of the window-blended cases was 82.7%, compared to 81.6% for conventional windows. The specificity of the window-blended cases was 93.1%, compared to 90.5% for conventional windows. All injuries of major clinical significance (per Nexus CT Chest criteria) were correctly identified in all reading sessions, and all negative cases were correctly classified. All readers demonstrated near-perfect agreement with injury severity classification with both window settings. In this pilot study utilizing retrospective data, window blending allows faster preliminary interpretation of axial chest CT performed for trauma, with no significant difference in diagnostic performance compared to conventional window settings. Future studies would be required to assess the utility of window blending in clinical practice. Copyright © 2018 The Association of University Radiologists. All rights reserved.

Characteristics of OMVPE grown GaAsBi QW lasers and impact of post-growth thermal annealing

NASA Astrophysics Data System (ADS)

Kim, Honghyuk; Guan, Yingxin; Babcock, Susan E.; Kuech, Thomas F.; Mawst, Luke J.

2018-03-01

Laser diodes employing a strain-compensated GaAs1-xBix/GaAs1-yPy single quantum well (SQW) active region were grown by organometallic vapor phase epitaxy (OMVPE). High resolution x-ray diffraction, room temperature photoluminescence, and real-time optical reflectance measurements during the OMVPE growth were used to find the optimum process window for the growth of the active region material. Systematic post-growth in situ thermal anneals of various lengths were carried out in order to investigate the impacts of thermal annealing on the laser device performance characteristics. While the lowest threshold current density was achieved after the thermal annealing for 30 min at 630 °C, a gradual decrease in the external differential quantum efficiency was observed as the annealing time increases. It was observed that the temperature sensitivities of the threshold current density increase while those of lasing wavelength and slope efficiency remain nearly constant with increasing annealing time. Z-contrast scanning transmission electron microscopic) analysis revealed inhomogeneous Bi distribution within the QW active region.

Coaxial microwave electrothermal thruster performance in hydrogen

NASA Technical Reports Server (NTRS)

Richardson, W.; Asmussen, J.; Hawley, M.

1994-01-01

The microwave electro thermal thruster (MET) is an electric propulsion concept that offers the promise of high performance combined with a long lifetime. A unique feature of this electric propulsion concept is its ability to create a microwave plasma discharge separated or floating away from any electrodes or enclosing walls. This allows propellant temperatures that are higher than those in resistojets and reduces electrode and wall erosion. It has been demonstrated that microwave energy is coupled into discharges very efficiently at high input power levels. As a result of these advantages, the MET concept has been identified as a future high power electric propulsion possibility. Recently, two additional improvements have been made to the coaxial MET. The first was concerned with improving the microwave matching. Previous experiments were conducted with 10-30 percent reflected power when incident power was in excess of 600 W(exp 6). Power was reflected back to the generator because the impedance of the MET did not match the 50 ohm impedance of the microwave circuit. To solve this problem, a double stub tuning system has been inserted between the MET and the microwave power supply. The addition of the double stub tuners reduces the reflected power below 1 percent. The other improvement has prepared the coaxial MET for hydrogen experiments. To operate with hydrogen, the vacuum window which separates the coaxial line from the discharge chamber has been changed from teflon to boron nitride. All the microwave energy delivered to the plasma discharge passes through this vacuum window. This material change had caused problems in the past because of the increased microwave reflection coefficients associated with the electrical properties of boron nitride. However, by making the boron nitride window electrically one-half of a wavelength long, power reflection in the window has been eliminated. This technical note summarizes the experimental performance of the improved coaxial MET when operating in nitrogen, helium, and hydrogen gases.

Polar rotor scattering as atomic-level origin of low mobility and thermal conductivity of perovskite CH3NH3PbI3

PubMed Central

Li, Bing; Kawakita, Yukinobu; Liu, Yucheng; Wang, Mingchao; Matsuura, Masato; Shibata, Kaoru; Ohira-Kawamura, Seiko; Yamada, Takeshi; Lin, Shangchao; Nakajima, Kenji; Liu, Shengzhong (Frank)

2017-01-01

Perovskite CH3NH3PbI3 exhibits outstanding photovoltaic performances, but the understanding of the atomic motions remains inadequate even though they take a fundamental role in transport properties. Here, we present a complete atomic dynamic picture consisting of molecular jumping rotational modes and phonons, which is established by carrying out high-resolution time-of-flight quasi-elastic and inelastic neutron scattering measurements in a wide energy window ranging from 0.0036 to 54 meV on a large single crystal sample, respectively. The ultrafast orientational disorder of molecular dipoles, activated at ∼165 K, acts as an additional scattering source for optical phonons as well as for charge carriers. It is revealed that acoustic phonons dominate the thermal transport, rather than optical phonons due to sub-picosecond lifetimes. These microscopic insights provide a solid standing point, on which perovskite solar cells can be understood more accurately and their performances are perhaps further optimized. PMID:28665407

Low-Enriched Uranium Nuclear Thermal Propulsion Systems

NASA Technical Reports Server (NTRS)

Houts, Michael G.; Mitchell, Doyce P.; Aschenbrenner, Ken

2017-01-01

The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. For example, using NTP for human Mars missions can provide faster transit and/or round trip times for crew; larger mission payloads; off nominal mission opportunities (including wider injection windows); and crew mission abort options not available from other architectures. The use of NTP can also reduce required earth-to-orbit launches, reducing cost and improving ground logistics. In addition to enabling robust human Mars mission architectures, NTP can be used on exploration missions throughout the solar system. A first generation NTP system could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. Progress made under the NTP project could also help enable high performance fission power systems and Nuclear Electric Propulsion (NEP). Guidance, navigation, and control of NTP may have some unique but manageable characteristics.

Diving through the thermal window: implications for a warming world

PubMed Central

Campbell, Hamish A.; Dwyer, Ross G.; Gordos, Matthew; Franklin, Craig E.

2010-01-01

Population decline and a shift in the geographical distribution of some ectothermic animals have been attributed to climatic warming. Here, we show that rises in water temperature of a few degrees, while within the thermal window for locomotor performance, may be detrimental to diving behaviour in air-breathing ectotherms (turtles, crocodilians, marine iguanas, amphibians, snakes and lizards). Submergence times and internal and external body temperature were remotely recorded from freshwater crocodiles (Crocodylus johnstoni) while they free-ranged throughout their natural habitat in summer and winter. During summer, the crocodiles' mean body temperature was 5.2 ± 0.1°C higher than in winter and the largest proportion of total dive time was composed of dive durations approximately 15 min less than in winter. Diving beyond 40 min during summer required the crocodiles to exponentially increase the time they spent on the surface after the dive, presumably to clear anaerobic debt. The relationship was not as significant in winter, even though a greater proportion of dives were of a longer duration, suggesting that diving lactate threshold (DLT) was reduced in summer compared with winter. Additional evidence for a reduced DLT in summer was derived from the stronger influence body mass exerted upon dive duration, compared to winter. The results demonstrate that the higher summer body temperature increased oxygen demand during the dive, implying that thermal acclimatization of the diving metabolic rate was inadequate. If the study findings are common among air-breathing diving ectotherms, then long-term warming of the aquatic environment may be detrimental to behavioural function and survivorship. PMID:20610433

CT thermometry for cone-beam CT guided ablation

NASA Astrophysics Data System (ADS)

DeStefano, Zachary; Abi-Jaoudeh, Nadine; Li, Ming; Wood, Bradford J.; Summers, Ronald M.; Yao, Jianhua

2016-03-01

Monitoring temperature during a cone-beam CT (CBCT) guided ablation procedure is important for prevention of over-treatment and under-treatment. In order to accomplish ideal temperature monitoring, a thermometry map must be generated. Previously, this was attempted using CBCT scans of a pig shoulder undergoing ablation.1 We are extending this work by using CBCT scans of real patients and incorporating more processing steps. We register the scans before comparing them due to the movement and deformation of organs. We then automatically locate the needle tip and the ablation zone. We employ a robust change metric due to image noise and artifacts. This change metric takes windows around each pixel and uses an equation inspired by Time Delay Analysis to calculate the error between windows with the assumption that there is an ideal spatial offset. Once the change map is generated, we correlate change data with measured temperature data at the key points in the region. This allows us to transform our change map into a thermal map. This thermal map is then able to provide an estimate as to the size and temperature of the ablation zone. We evaluated our procedure on a data set of 12 patients who had a total of 24 ablation procedures performed. We were able to generate reasonable thermal maps with varying degrees of accuracy. The average error ranged from 2.7 to 16.2 degrees Celsius. In addition to providing estimates of the size of the ablation zone for surgical guidance, 3D visualizations of the ablation zone and needle are also produced.

Context Switching with Multiple Register Windows: A RISC Performance Study

NASA Technical Reports Server (NTRS)

Konsek, Marion B.; Reed, Daniel A.; Watcharawittayakul, Wittaya

1987-01-01

Although previous studies have shown that a large file of overlapping register windows can greatly reduce procedure call/return overhead, the effects of register windows in a multiprogramming environment are poorly understood. This paper investigates the performance of multiprogrammed, reduced instruction set computers (RISCs) as a function of window management strategy. Using an analytic model that reflects context switch and procedure call overheads, we analyze the performance of simple, linearly self-recursive programs. For more complex programs, we present the results of a simulation study. These studies show that a simple strategy that saves all windows prior to a context switch, but restores only a single window following a context switch, performs near optimally.

Effects of temperature-dependent molecular absorption coefficients on the thermal infrared remote sensing of the earth surface

NASA Technical Reports Server (NTRS)

Wan, Zhengming; Dozier, Jeff

1992-01-01

The effect of temperature-dependent molecular absorption coefficients on thermal infrared spectral signatures measured from satellite sensors is investigated by comparing results from the atmospheric transmission and radiance codes LOWTRAN and MODTRAN and the accurate multiple scattering radiative transfer model ATRAD for different atmospheric profiles. The sensors considered include the operational NOAA AVHRR and two research instruments planned for NASA's Earth Observing System (EOS): MODIS-N (Moderate Resolution Imaging Spectrometer-Nadir-Mode) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer). The difference in band transmittance is as large as 6 percent for some thermal bands within atmospheric windows and more than 30 percent near the edges of these atmospheric windows. The effect of temperature-dependent molecular absorption coefficients on satellite measurements of sea-surface temperature can exceed 0.6 K. Quantitative comparison and factor analysis indicate that more accurate measurements of molecular absorption coefficients and better radiative transfer simulation methods are needed to achieve SST accuracy of 0.3 K, as required for global numerical models of climate, and to develop land-surface temperature algorithms at the 1-K accuracy level.

Centrifugal compressor fault diagnosis based on qualitative simulation and thermal parameters

NASA Astrophysics Data System (ADS)

Lu, Yunsong; Wang, Fuli; Jia, Mingxing; Qi, Yuanchen

2016-12-01

This paper concerns fault diagnosis of centrifugal compressor based on thermal parameters. An improved qualitative simulation (QSIM) based fault diagnosis method is proposed to diagnose the faults of centrifugal compressor in a gas-steam combined-cycle power plant (CCPP). The qualitative models under normal and two faulty conditions have been built through the analysis of the principle of centrifugal compressor. To solve the problem of qualitative description of the observations of system variables, a qualitative trend extraction algorithm is applied to extract the trends of the observations. For qualitative states matching, a sliding window based matching strategy which consists of variables operating ranges constraints and qualitative constraints is proposed. The matching results are used to determine which QSIM model is more consistent with the running state of system. The correct diagnosis of two typical faults: seal leakage and valve stuck in the centrifugal compressor has validated the targeted performance of the proposed method, showing the advantages of fault roots containing in thermal parameters.

Analysis of woven and braided fabric reinforced composites

NASA Technical Reports Server (NTRS)

Naik, Rajiv A.

1994-01-01

A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell, was developed to predict overall, three dimensional, thermal and mechanical properties. This analytical technique was implemented in a user-friendly, personal computer-based, windows compatible code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain, 5-harness satin, and 8-harness satin weave composites along with 2-D braided and 2x2, 2-D triaxial braided composites. The calculated overall stiffnesses correlated well with available 3-D finite element results and test data for both the woven and the braided composites. Parametric studies were performed to investigate the effects of yarn size on the yarn crimp and the overall thermal and mechanical constants for plain weave composites. The effects of braid angle were investigated for the 2-D braided composites. Finally, the effects of fiber volume fraction on the yarn undulations and the thermal and mechanical properties of 2x2, 2-D triaxial braided composites were also investigated.

Experimental Investigation of Thermal Performance in a Vehicle Cabin Test Setup With Pcm in the Roof

NASA Astrophysics Data System (ADS)

Purusothaman, M.; kota, Saichand; Cornilius, C. Sam; Siva, R.

2017-05-01

Heat flow from the roof with radiation through glass windows obviously high level that contributes to the total heat gained of a vehicle cabin. The cabin temperature of closed stationary vehicles in direct sunlight can quickly rise to a very level that may damage property and harm children or pets left in the vehicle. The problem that is faced by many car users today is very hot interior after certain minutes or hours of parking in open or un-shaded parking area. The heat accumulated inside the vehicle with undesired temperature rise would cause the parts of the car’s interior to degrade. Even the passengers are affected with the thermal condition inside the vehicle itself. The passenger has to wait for a certain time before getting into the car to cool down the interior condition either by lowering down the window or switching on the air conditioner at high speed that really affect the fuel consumption. A new roofing structure to improve its total thermal resistance is developed. Its uses phase change material properties to trap the heat from solar radiation and then release it back to the outer atmosphere by external convection when the vehicle is in use or during the nocturnal cycle. Phase change material, which has become an attractive means to store. Thermal energy, which has a wide range of applications, has been used. Phase change material has a high heat of fusion which is able to store and release large amount of energy. This PCM has been insulated in the roof of the vehicle to arrest the heat entering into the vehicle cabin. Experimental and numerical analyses have been conducted to compare the thermal performance of the new roofing structure and the normal roofing. By this experiment, the cooling process of the cabin could be much lower. The experimental investigation revealed that, on a hot day, the interior temperature of the vehicles cabin was approximately 22ºCe higher than the ambient temperature. The results show that the new roofing structure could effectively reduce the inlet of heat from the roof into the cabin. As a result, the interior temperature of the cabin could be much lower.

Atomic Linkage Flexibility Tuned Isotropic Negative, Zero, and Positive Thermal Expansion in MZrF 6 (M = Ca, Mn, Fe, Co, Ni, and Zn)

DOE PAGES

Hu, Lei; Chen, Jun; Xu, Jiale; ...

2016-10-26

The controllable isotropic thermal expansion with a broad coefficient of thermal expansion (CTE) window is intriguing but remains challenge. Herein we report a cubic MZrF 6 series (M = Ca, Mn, Fe, Co, Ni and Zn), which exhibit controllable thermal expansion over a wide temperature range and with a broader CTE window (–6.69 to +18.23 × 10 –6/K). In particular, an isotropic zero thermal expansion (ZTE) is achieved in ZnZrF 6, which is one of the rarely documented hightemperature isotropic ZTE compounds. By utilizing temperature dependent high-energy synchrotron X-ray total scattering diffraction, it is found that the flexibility of metal···Fmore » atomic linkages in MZrF 6 plays a critical role in distinct thermal expansions. The flexible metal···F atomic linkages induce negative thermal expansion (NTE) for CaZrF 6, whereas the stiff ones bring positive thermal expansion (PTE) for 6. Thermal expansion could be transformed from striking negative, to zero, and finally to considerable positive though tuning the flexibility of metal···F atomic linkages by substitution with a series of cations on M sites of MZrF 6. In conclusion, the present study not only extends the scope of NTE families and rare high-temperature isotropic ZTE compounds but also proposes a new method to design systematically controllable isotropic thermal expansion frameworks from the perspective of atomic linkage flexibility.« less

Atomic Linkage Flexibility Tuned Isotropic Negative, Zero, and Positive Thermal Expansion in MZrF 6 (M = Ca, Mn, Fe, Co, Ni, and Zn)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Lei; Chen, Jun; Xu, Jiale

The controllable isotropic thermal expansion with a broad coefficient of thermal expansion (CTE) window is intriguing but remains challenge. Herein we report a cubic MZrF 6 series (M = Ca, Mn, Fe, Co, Ni and Zn), which exhibit controllable thermal expansion over a wide temperature range and with a broader CTE window (–6.69 to +18.23 × 10 –6/K). In particular, an isotropic zero thermal expansion (ZTE) is achieved in ZnZrF 6, which is one of the rarely documented hightemperature isotropic ZTE compounds. By utilizing temperature dependent high-energy synchrotron X-ray total scattering diffraction, it is found that the flexibility of metal···Fmore » atomic linkages in MZrF 6 plays a critical role in distinct thermal expansions. The flexible metal···F atomic linkages induce negative thermal expansion (NTE) for CaZrF 6, whereas the stiff ones bring positive thermal expansion (PTE) for 6. Thermal expansion could be transformed from striking negative, to zero, and finally to considerable positive though tuning the flexibility of metal···F atomic linkages by substitution with a series of cations on M sites of MZrF 6. In conclusion, the present study not only extends the scope of NTE families and rare high-temperature isotropic ZTE compounds but also proposes a new method to design systematically controllable isotropic thermal expansion frameworks from the perspective of atomic linkage flexibility.« less

Low-cost, highly transparent flexible low-e coating film to enable electrochromic windows with increased energy savings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berland, Brian; Hollingsworth, Russell

Five Quads of energy are lost through windows annually in the U.S. Low-e coatings are increasingly employed to reduce the wasted energy. Most commonly, the low-e coating is an oxide material applied directly to the glass at high temperature. With over 100,000,000 existing homes, a retrofit product is crucial to achieve widespread energy savings. Low-e films, i.e. coatings on polymeric substrates, are now also available to meet this need. However, the traditional oxide materials and process is incompatible with low temperature plastics. Alternate high performing low-e films typically incorporate materials that limit visible transmission to 35% or less. Further, themore » cost is high. The objective of this award was to develop a retrofit, integrated low-e/electrochromic window film to dramatically reduce energy lost through windows. While field testing of state-of-the-art electrochromic (EC) windows show the energy savings are maximized if a low-e coating is used in conjunction with the EC, available low-e films have a low visible transmission (~70% or less) that limits the achievable clear state and therefore, appearance and energy savings potential. Comprehensive energy savings models were completed at Lawrence Berkeley National Lab (LBNL). A parametric approach was used to project energy usage for windows with a large range of low-e properties across all U.S. climate zones, without limiting the study to materials that had already been produced commercially or made in a lab. The model enables projection of energy savings for low-e films as well as integrated low-e/EC products. This project developed a novel low-e film, optimized for compatibility with EC windows, using low temperature, high deposition rate processes for the growth of low-e coatings on plastic films by microwave plasma enhanced chemical vapor deposition. Silica films with good density and optical properties were demonstrated at deposition rates as high as 130Å/sec. A simple bi-layer low-e stack of silica and a transparent conductive oxide demonstrated 90% visible transmission with high thermal infrared reflectivity characteristic of conventional low-e coatings. A slightly more complex stack provided high solar infrared reflection without sacrificing visible transmission or thermal infrared reflection. Successful completion of the effort produced a prototype integrated low-e, dynamic window film with characterized energy saving potential. Cost modeling for the passive bi-layer, low-e film projects a manufacturing cost of ~$0.50/ft2 for a plant with 10M ft2/yr capacity. The novel thin film processes developed here enable high deposition rate (low cost), optical quality oxide coatings at low temperatures. When combined with engineered materials, ITN’s coating will result in low-cost, low-e films that reflect a high degree of infrared radiation without substantially reducing the visible transmission. The resultant window film will improve the U-value and achieve SHGC improvements over bare glass. The new low-e coating will be particularly attractive when combined with an electrochromic film. Low-e coating design guided by energy savings modeling allows customization of the product for different climate zones.« less

Theoretical vibro-acoustic modeling of acoustic noise transmission through aircraft windows

NASA Astrophysics Data System (ADS)

Aloufi, Badr; Behdinan, Kamran; Zu, Jean

2016-06-01

In this paper, a fully vibro-acoustic model for sound transmission across a multi-pane aircraft window is developed. The proposed model is efficiently applied for a set of window models to perform extensive theoretical parametric studies. The studied window configurations generally simulate the passenger window designs of modern aircraft classes which have an exterior multi-Plexiglas pane, an interior single acrylic glass pane and a dimmable glass ("smart" glass), all separated by thin air cavities. The sound transmission loss (STL) characteristics of three different models, triple-, quadruple- and quintuple-paned windows identical in size and surface density, are analyzed for improving the acoustic insulation performances. Typical results describing the influence of several system parameters, such as the thicknesses, number and spacing of the window panes, on the transmission loss are then investigated. In addition, a comparison study is carried out to evaluate the acoustic reduction capability of each window model. The STL results show that the higher frequencies sound transmission loss performance can be improved by increasing the number of window panels, however, the low frequency performance is decreased, particularly at the mass-spring resonances.

Self-Cleaning Anticondensing Glass via Supersonic Spraying of Silver Nanowires, Silica, and Polystyrene Nanoparticles.

PubMed

Lee, Jong-Gun; An, Seongpil; Kim, Tae-Gun; Kim, Min-Woo; Jo, Hong-Seok; Swihart, Mark T; Yarin, Alexander L; Yoon, Sam S

2017-10-11

We have sequentially deposited layers of silver nanowires (AgNWs), silicon dioxide (SiO 2 ) nanoparticles, and polystyrene (PS) nanoparticles on uncoated glass by a rapid low-cost supersonic spraying method to create antifrosting, anticondensation, and self-cleaning glass. The conductive silver nanowire network embedded in the coating allows electrical heating of the glass surface. Supersonic spraying is a single-step coating technique that does not require vacuum. The fabricated multifunctional glass was characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), ultraviolet-visible spectroscopy, and transmission electron microscopy (TEM). The thermal insulation and antifrosting performance were demonstrated using infrared thermal imaging. The reliability of the electrical heating function was tested through extensive cycling. This transparent multifunctional coating holds great promise for use in various smart window designs.

Closeup view of the exterior of the starboard side of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of the exterior of the starboard side of the forward fuselage of the Orbiter Discovery looking at the forward facing observation windows of the flight deck. Note the High-temperature Reusable Surface Insulation (HRSI) surrounding the window openings, the Low-temperature Reusable Surface Insulation (LRSI) immediately beyond the HRSI tiles and the Advanced Flexible Reusable Surface Insulation blankets just beyond the LRSI tiles. The holes in the tiles are injection points for the application of waterproofing material. The windows are composed of redundant pressure window panes of thermal glass. This image was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Heavy liquid metals: Research programs at PSI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeda, Y.

1996-06-01

The author describes work at PSI on thermohydraulics, thermal shock, and material tests for mechnical properties. In the presentation, the focus is on two main programs. (1) SINQ LBE target: The phase II study program for SINQ is planned. A new LBE loop is being constructed. The study has the following three objectives: (a) Pump study - design work on an electromagnetic pump to be integrated into the target. (b) Heat pipe performance test - the use of heat pipes as an additional component of the target cooling system is being considered, and it may be a way to futhermore » decouple the liquid metal and water coolant loops. (c) Mixed convection experiment - in order to find an optimal configuration of the additional flow guide for window cooling, mixed convection around the window is to be studied. The experiment will be started using water and then with LBE. (2) ESS Mercury target: For ESS target study, the following experimental studies are planned, some of which are exampled by trial experiments. (a) Flow around the window: Flow mapping around the hemi-cylindrical window will be made for optimising the flow channels and structures, (b) Geometry optimisation for minimizing a recirculation zone behind the edge of the flow separator, (c) Flow induced vibration and buckling problem for a optimised structure of the flow separator and (d) Gas-liquid two-phase flow will be studied by starting to establish the new experimental method of measuring various kinds of two-phase flow characteristics.« less

Wide memory window in graphene oxide charge storage nodes

NASA Astrophysics Data System (ADS)

Wang, Shuai; Pu, Jing; Chan, Daniel S. H.; Cho, Byung Jin; Loh, Kian Ping

2010-04-01

Solution-processable, isolated graphene oxide (GO) monolayers have been used as a charge trapping dielectric in TaN gate/Al2O3/isolated GO sheets/SiO2/p-Si memory device (TANOS). The TANOS type structure serves as memory device with the threshold voltage controlled by the amount of charge trapped in the GO sheet. Capacitance-Voltage hysteresis curves reveal a 7.5 V memory window using the sweep voltage of -5-14 V. Thermal reduction in the GO to graphene reduces the memory window to 1.4 V. The unique charge trapping properties of GO points to the potential applications in flexible organic memory devices.

Synthesis of optically clear polymeric materials for high temperature windows. [preparation of phenolphthalein polycarbonate resin

NASA Technical Reports Server (NTRS)

Pannell, C. E.; Magner, J. E.

1973-01-01

A polymer has been developed that has excellent potential for use as windows in spacecraft as well as conventional aircraft. This polymer, phenolphthalein polycarbonate, has outstanding thermal properties, e.g., in place of melting or burning, it produces an insulating charred foam that closes off transmission of radiant heat through the window. This fact, coupled with an oxygen index of 0.43 and a 177 C tensile strength of 58 mega Newtons/sq m, makes this polymer a prime candidate for further development. Pilot plant preparation in a 20 gallon Pfaudler kettle was accomplished and large test specimens were prepared for evaluations.

Structural and chemical evolution of the CdS:O window layer during individual CdTe solar cell processing steps

DOE PAGES

Abbas, A.; Meysing, D. M.; Reese, M. O.; ...

2017-12-01

Oxygenated cadmium sulfide (CdS:O) is often used as the n-type window layer in high-performance CdTe heterojunction solar cells. The as-deposited layer prepared by reactive sputtering is XRD amorphous, with a bulk composition of CdS0.8O1.2. Recently it was shown that this layer undergoes significant transformation during device fabrication, but the roles of the individual high temperature processing steps was unclear. In this work high resolution transmission electron microscopy coupled to elemental analysis was used to understand the evolution of the heterojunction region through the individual high temperature fabrication steps of CdTe deposition, CdCl2 activation, and back contact activation. It is foundmore » that during CdTe deposition by close spaced sublimation at 600 degrees C the CdS:O film undergoes recrystallization, accompanied by a significant (~30%) reduction in thickness. It is observed that oxygen segregates during this step, forming a bi-layer morphology consisting of nanocrystalline CdS adjacent to the tin oxide contact and an oxygen-rich layer adjacent to the CdTe absorber. This bilayer structure is then lost during the 400 degrees C CdCl2 treatment where the film transforms into a heterogeneous structure with cadmium sulfate clusters distributed randomly throughout the window layer. The thickness of window layer remains essentially unchanged after CdCl2 treatment, but a ~25 nm graded interfacial layer between CdTe and the window region is formed. Finally, the rapid thermal processing step used to activate the back contact was found to have a negligible impact on the structure or composition of the heterojunction region.« less

Structural and chemical evolution of the CdS:O window layer during individual CdTe solar cell processing steps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbas, A.; Meysing, D. M.; Reese, M. O.

Oxygenated cadmium sulfide (CdS:O) is often used as the n-type window layer in high-performance CdTe heterojunction solar cells. The as-deposited layer prepared by reactive sputtering is XRD amorphous, with a bulk composition of CdS0.8O1.2. Recently it was shown that this layer undergoes significant transformation during device fabrication, but the roles of the individual high temperature processing steps was unclear. In this work high resolution transmission electron microscopy coupled to elemental analysis was used to understand the evolution of the heterojunction region through the individual high temperature fabrication steps of CdTe deposition, CdCl2 activation, and back contact activation. It is foundmore » that during CdTe deposition by close spaced sublimation at 600 degrees C the CdS:O film undergoes recrystallization, accompanied by a significant (~30%) reduction in thickness. It is observed that oxygen segregates during this step, forming a bi-layer morphology consisting of nanocrystalline CdS adjacent to the tin oxide contact and an oxygen-rich layer adjacent to the CdTe absorber. This bilayer structure is then lost during the 400 degrees C CdCl2 treatment where the film transforms into a heterogeneous structure with cadmium sulfate clusters distributed randomly throughout the window layer. The thickness of window layer remains essentially unchanged after CdCl2 treatment, but a ~25 nm graded interfacial layer between CdTe and the window region is formed. Finally, the rapid thermal processing step used to activate the back contact was found to have a negligible impact on the structure or composition of the heterojunction region.« less

Wall temperature measurements at elevated pressures and high temperatures in sooting flames in a gas turbine model combustor

NASA Astrophysics Data System (ADS)

Nau, Patrick; Yin, Zhiyao; Geigle, Klaus Peter; Meier, Wolfgang

2017-12-01

Wall temperatures were measured with thermographic phosphors on the quartz walls of a model combustor in ethylene/air swirl flames at 3 bar. Three operating conditions were investigated with different stoichiometries and with or without additional injection of oxidation air downstream of the primary combustion zone. YAG:Eu and YAG:Dy were used to cover a total temperature range of 1000-1800 K. Measurements were challenging due to the high thermal background from soot and window degradation at high temperatures. The heat flux through the windows was estimated from the temperature gradient between the in- and outside of the windows. Differences in temperature and heat flux density profiles for the investigated cases can be explained very well with the previously measured differences in flame temperatures and flame shapes. The heat loss relative to thermal load is quite similar for all investigated flames (15-16%). The results complement previous measurements in these flames to investigate soot formation and oxidation. It is expected, that the data set is a valuable input for numerical simulations of these flames.

Viking Mars launch set for August 11

NASA Technical Reports Server (NTRS)

Panagakos, N.

1975-01-01

The 1975-1976 Viking Mars Mission is described in detail, from launch phase through landing and communications relay phase. The mission's scientific goals are outlined and the various Martian investigations are discussed. These investigations include: geological photomapping and seismology; high-resolution, stereoscopic horizon scanning; water vapor and thermal mapping; entry science; meteorology; atmospheric composition and atmospheric density; and, search for biological products. The configurations of the Titan 3/Centaur combined launch vehicles, the Viking orbiters, and the Viking landers are described; their subsystems and performance characteristics are discussed. Preflight operations, launch window, mission control, and the deep space tracking network are also presented.

Digitized detection of gamma-ray signals concentrated in narrow time windows for transient positron annihilation lifetime spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinomura, A., E-mail: a.kinomura@aist.go.jp; Suzuki, R.; Oshima, N.

2014-12-15

A pulsed slow-positron beam generated by an electron linear accelerator was directly used for positron annihilation lifetime spectroscopy without any positron storage devices. A waveform digitizer was introduced to simultaneously capture multiple gamma-ray signals originating from positron annihilation events during a single accelerator pulse. The positron pulse was chopped and bunched with the chopper signals also sent to the waveform digitizer. Time differences between the annihilation gamma-ray and chopper peaks were calculated and accumulated as lifetime spectra in a computer. The developed technique indicated that positron annihilation lifetime spectroscopy can be performed in a 20 μs time window at amore » pulse repetition rate synchronous with the linear accelerator. Lifetime spectra of a Kapton sheet and a thermally grown SiO{sub 2} layer on Si were successfully measured. Synchronization of positron lifetime measurements with pulsed ion irradiation was demonstrated by this technique.« less

Final Results of Shuttle MMOD Impact Database

NASA Technical Reports Server (NTRS)

Hyde, J. L.; Christiansen, E. L.; Lear, D. M.

2015-01-01

The Shuttle Hypervelocity Impact Database documents damage features on each Orbiter thought to be from micrometeoroids (MM) or orbital debris (OD). Data is divided into tables for crew module windows, payload bay door radiators and thermal protection systems along with other miscellaneous regions. The combined number of records in the database is nearly 3000. Each database record provides impact feature dimensions, location on the vehicle and relevant mission information. Additional detail on the type and size of particle that produced the damage site is provided when sampling data and definitive spectroscopic analysis results are available. Guidelines are described which were used in determining whether impact damage is from micrometeoroid or orbital debris impact based on the findings from scanning electron microscopy chemical analysis. Relationships assumed when converting from observed feature sizes in different shuttle materials to particle sizes will be presented. A small number of significant impacts on the windows, radiators and wing leading edge will be highlighted and discussed in detail, including the hypervelocity impact testing performed to estimate particle sizes that produced the damage.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahajan, Mani, E-mail: manimahajan86@gmail.com; Singla, Gourav, E-mail: gsinghla@gmail.com; Singh, K., E-mail: kusingh@thapar.edu

Carbon nanospheres of grape-like structure (CNS) with diameter ranging from 40 to 50 nm and wall thickness of 6–8 nm were synthesized by solvothermal route. The phase structure, morphology, microstructure, thermal stability, disorder and optical properties of synthesized CNS were investigated by various characterization techniques. The possible formation and growth mechanism for CNS were discussed on the basis of the in-build reaction conditions. The degradation study of organic pollutants (methylene blue) in UV light in the presence of synthesized CNS was done. The stability of the CNS in electrochemical performance was also discussed at the different potential window and comparedmore » its electrocatalytic activity with platinum supported on CNS which shows the better response for oxygen reduction reactions (ORR) at an optimized potential window (–0.2 to 1.0 V vs SCE). - Graphical abstract: A representative synthesis mechanism of carbon nano sphere (CNS) showing spherical morphology with its photo as well as electrocatalyst properties. - Highlights: • Carbon nanospheres (CNS) have been synthesized using in situ chemical-reduction route. • The bare CNS shows good luminescence and photocatalytic applications. • The Pt/CNS shows better electrochemical performance than the reported Pt/C.« less

Thermal Infrared Multispectral Scanner (TIMS): An investigator's guide to TIMS data

NASA Technical Reports Server (NTRS)

Palluconi, F. D.; Meeks, G. R.

1985-01-01

The Thermal Infrared Multispectral Scanner (TIMS) is a NASA aircraft scanner providing six channel spectral capability in the thermal infrared region of the electromagnetic spectrum. Operating in the atmospheric window region (8 to 12 micrometers) with a channel sensitivity of approximately 0.1 C, TIMS may be used whenever an accurate measure of the Earth's surface is needed. A description of this scanner is provided as well as a discussion of data acquisition and reduction.

How to be smart and energy efficient: A general discussion on thermochromic windows

PubMed Central

Long, Linshuang; Ye, Hong

2014-01-01

A window is a unique element in a building because of its simultaneous properties of being “opaque” to inclement weather yet transparent to the observer. However, these unique features make the window an element that can reduce the energy efficiency of buildings. A thermochromic window is a type of smart window whose solar radiation properties vary with temperature. It is thought that the solar radiation gain of a room can be intelligently regulated through the use of thermochromic windows, resulting in lower energy consumption than with standard windows. Materials scientists have made many efforts to improve the performance of thermochromic materials. Despite these efforts, fundamental problems continue to confront us. How should a “smart” window behave? Is a “smart” window really the best candidate for energy-efficient applications? What is the relationship between smartness and energy performance? To answer these questions, a general discussion of smartness and energy performance is provided. PMID:25233891

Feasibility Study of LANDSAT-8 Imagery for Retrieving Sea Surface Temperature (case Study Persian Gulf)

NASA Astrophysics Data System (ADS)

Bayat, F.; Hasanlou, M.

2016-06-01

Sea surface temperature (SST) is one of the critical parameters in marine meteorology and oceanography. The SST datasets are incorporated as conditions for ocean and atmosphere models. The SST needs to be investigated for various scientific phenomenon such as salinity, potential fishing zone, sea level rise, upwelling, eddies, cyclone predictions. On the other hands, high spatial resolution SST maps can illustrate eddies and sea surface currents. Also, near real time producing of SST map is suitable for weather forecasting and fishery applications. Therefore satellite remote sensing with wide coverage of data acquisition capability can use as real time tools for producing SST dataset. Satellite sensor such as AVHRR, MODIS and SeaWIFS are capable of extracting brightness values at different thermal spectral bands. These brightness temperatures are the sole input for the SST retrieval algorithms. Recently, Landsat-8 successfully launched and accessible with two instruments on-board: (1) the Operational Land Imager (OLI) with nine spectral bands in the visual, near infrared, and the shortwave infrared spectral regions; and (2) the Thermal Infrared Sensor (TIRS) with two spectral bands in the long wavelength infrared. The two TIRS bands were selected to enable the atmospheric correction of the thermal data using a split window algorithm (SWA). The TIRS instrument is one of the major payloads aboard this satellite which can observe the sea surface by using the split-window thermal infrared channels (CH10: 10.6 μm to 11.2 μm; CH11: 11.5 μm to 12.5 μm) at a resolution of 30 m. The TIRS sensors have three main advantages comparing with other previous sensors. First, the TIRS has two thermal bands in the atmospheric window that provide a new SST retrieval opportunity using the widely used split-window (SW) algorithm rather than the single channel method. Second, the spectral filters of TIRS two bands present narrower bandwidth than that of the thermal band on board on previous Landsat sensors. Third, TIRS is one of the best space born and high spatial resolution with 30 m. in this regards, Landsat-8 can use the Split-Window (SW) algorithm for retrieving SST dataset. Although several SWs have been developed to use with other sensors, some adaptations are required in order to implement them for the TIRS spectral bands. Therefore, the objective of this paper is to develop a SW, adapted for use with Landsat-8 TIRS data, along with its accuracy assessment. In this research, that has been done for modelling SST using thermal Landsat 8-imagery of the Persian Gulf. Therefore, by incorporating contemporary in situ data and SST map estimated from other sensors like MODIS, we examine our proposed method with coefficient of determination (R2) and root mean square error (RMSE) on check point to model SST retrieval for Landsat-8 imagery. Extracted results for implementing different SW's clearly shows superiority of utilized method by R2 = 0.95 and RMSE = 0.24.

Data in support of energy performance of double-glazed windows.

PubMed

Shakouri, Mahmoud; Banihashemi, Saeed

2016-06-01

This paper provides the data used in a research project to propose a new simplified windows rating system based on saved annual energy ("Developing an empirical predictive energy-rating model for windows by using Artificial Neural Network" (Shakouri Hassanabadi and Banihashemi Namini, 2012) [1], "Climatic, parametric and non-parametric analysis of energy performance of double-glazed windows in different climates" (Banihashemi et al., 2015) [2]). A full factorial simulation study was conducted to evaluate the performance of 26 different types of windows in a four-story residential building. In order to generalize the results, the selected windows were tested in four climates of cold, tropical, temperate, and hot and arid; and four different main orientations of North, West, South and East. The accompanied datasets include the annual saved cooling and heating energy in different climates and orientations by using the selected windows. Moreover, a complete dataset is provided that includes the specifications of 26 windows, climate data, month, and orientation of the window. This dataset can be used to make predictive models for energy efficiency assessment of double glazed windows.

At the edge of the thermal window: effects of elevated temperature on the resting metabolism, hypoxia tolerance and upper critical thermal limit of a widespread African cichlid

PubMed Central

McDonnell, Laura H.; Chapman, Lauren J.

2015-01-01

Tropical inland fishes are predicted to be especially vulnerable to thermal stress because they experience small temperature fluctuations that may select for narrow thermal windows. In this study, we measured resting metabolic rate (RMR), critical oxygen tension (Pcrit) and critical thermal maximum (CTMax) of the widespread African cichlid (Pseudocrenilabrus multicolor victoriae) in response to short-term acclimation to temperatures within and above their natural thermal range. Pseudocrenilabrus multicolor collected in Lake Kayanja, Uganda, a population living near the upper thermal range of the species, were acclimated to 23, 26, 29 and 32°C for 3 days directly after capture, and RMR and Pcrit were then quantified. In a second group of P. multicolor from the same population, CTMax and the thermal onset of agitation were determined for fish acclimated to 26, 29 and 32°C for 7 days. Both RMR and Pcrit were significantly higher in fish acclimated to 32°C, indicating decreased tolerance to hypoxia and increased metabolic requirements at temperatures only slightly (∼1°C) above their natural thermal range. The CTMax increased with acclimation temperature, indicating some degree of thermal compensation induced by short-term exposure to higher temperatures. However, agitation temperature (likely to represent an avoidance response to increased temperature during CTMax trials) showed no increase with acclimation temperature. Overall, the results of this study demonstrate that P. multicolor is able to maintain its RMR and Pcrit across the range of temperatures characteristic of its natural habitat, but incurs a higher cost of resting metabolism and reduced hypoxia tolerance at temperatures slightly above its present range. PMID:27293734

Low-Emissivity, Energy-Control, Retrofit Window Film: Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winckler, Lisa

Solutia Performance Films, utilizing funding from the U.S. Department of Energy's Buildings Technologies Program, completed research to develop, validate, and commercialize a range of cost-effective, low-emissivity energy-control retrofit window films with significantly improved emissivity over current technology. These films, sold under the EnerLogic® trade name, offer the energy-saving properties of modern low-e windows, with several advantages over replacement windows, such as: lower initial installation cost, a significantly lower product carbon footprint, and an ability to provide a much faster return on investment. EnerLogic® window films also offer significantly greater energy savings than previously available with window films with similar visiblemore » light transmissions. EnerLogic® window films offer these energy-saving advantages over other window films due to its ability to offer both summer cooling and winter heating savings. Unlike most window films, that produce savings only during the cooling season, EnerLogic® window film is an all-season, low-emissivity (low-e) film that produces both cooling and heating season savings. This paper will present technical information on the development hurdles as well as details regarding the following claims being made about EnerLogic® window film, which can be found at www.EnerLogicfilm.com: 1. Other window film technologies save energy. EnerLogic® window film's patent-pending coating delivers excellent energy efficiency in every season, so no other film can match its annual dollar or energy consumption savings. 2. EnerLogic® window film is a low-cost, high-return technology that compares favorably to other popular energy-saving measures both in terms of energy efficiency and cost savings. In fact, EnerLogic® window film typically outperforms most of the alternatives in terms of simple payback. 3. EnerLogic® window film provides unparalleled glass insulating capabilities for window film products. With its patent-pending low-e technology, EnerLogic® window film has the best insulating performance of any film product available. The insulating power of EnerLogic® window film gives single-pane windows the annual insulating performance of double-pane windows - and gives double-pane windows the annual insulating performance of triple-pane windows.« less

Fused silica windows for solar receiver applications

NASA Astrophysics Data System (ADS)

Hertel, Johannes; Uhlig, Ralf; Söhn, Matthias; Schenk, Christian; Helsch, Gundula; Bornhöft, Hansjörg

2016-05-01

A comprehensive study of optical and mechanical properties of quartz glass (fused silica) with regard to application in high temperature solar receivers is presented. The dependence of rupture strength on different surface conditions as well as high temperature is analyzed, focussing particularly on damage by devitrification and sandblasting. The influence of typical types of contamination in combination with thermal cycling on the optical properties of fused silica is determined. Cleaning methods are compared regarding effectiveness on contamination-induced degradation for samples with and without antireflective coating. The FEM-aided design of different types of receiver windows and their support structure is presented. A large-scale production process has been developed for producing fused silica dome shaped windows (pressurized window) up to a diameter of 816 mm. Prototypes were successfully pressure-tested in a test bench and certified according to the European Pressure Vessel Directive.

Advanced Solar Receivers

NASA Technical Reports Server (NTRS)

Owen, W. A.

1984-01-01

Low thermal efficiencies in solar receivers are discussed in terms of system design. It is recommended that careful attention be given to the overall thermal systems design, especially to conductive losses about the window and areas of relatively thin insulation. If the cavity design is carefully managed to insure a small, minimally reradiating aperture, the goal of a very high efficiency cavity receiver is a realistic one.

Elevated temperature and acclimation time affect metabolic performance in the heavily exploited Nile perch of Lake Victoria.

PubMed

Nyboer, Elizabeth A; Chapman, Lauren J

2017-10-15

Increasing water temperatures owing to anthropogenic climate change are predicted to negatively impact the aerobic metabolic performance of aquatic ectotherms. Specifically, it has been hypothesized that thermal increases result in reductions in aerobic scope (AS), which lead to decreases in energy available for essential fitness and performance functions. Consequences of warming are anticipated to be especially severe for warm-adapted tropical species as they are thought to have narrow thermal windows and limited plasticity for coping with elevated temperatures. In this study we test how predicted warming may affect the aerobic performance of Nile perch ( Lates niloticus ), a commercially harvested fish species in the Lake Victoria basin of East Africa. We measured critical thermal maxima (CT max ) and key metabolic variables such as AS and excess post-exercise oxygen consumption (EPOC) across a range of temperatures, and compared responses between acute (3-day) exposures and 3-week acclimations. CT max increased with acclimation temperature; however, 3-week-acclimated fish had higher overall CT max than acutely exposed individuals. Nile perch also showed the capacity to increase or maintain high AS even at temperatures well beyond their current range; however, acclimated Nile perch had lower AS compared with acutely exposed fish. These changes were accompanied by lower EPOC, suggesting that drops in AS may reflect improved energy utilization after acclimation, a finding that is supported by improvements in growth at high temperatures over the acclimation period. Overall, the results challenge predictions that tropical species have limited thermal plasticity, and that high temperatures will be detrimental because of limitations in AS. © 2017. Published by The Company of Biologists Ltd.

Effect of window length on performance of the elbow-joint angle prediction based on electromyography

NASA Astrophysics Data System (ADS)

Triwiyanto; Wahyunggoro, Oyas; Adi Nugroho, Hanung; Herianto

2017-05-01

The high performance of the elbow joint angle prediction is essential on the development of the devices based on electromyography (EMG) control. The performance of the prediction depends on the feature of extraction parameters such as window length. In this paper, we evaluated the effect of the window length on the performance of the elbow-joint angle prediction. The prediction algorithm consists of zero-crossing feature extraction and second order of Butterworth low pass filter. The feature was used to extract the EMG signal by varying window length. The EMG signal was collected from the biceps muscle while the elbow was moved in the flexion and extension motion. The subject performed the elbow motion by holding a 1-kg load and moved the elbow in different periods (12 seconds, 8 seconds and 6 seconds). The results indicated that the window length affected the performance of the prediction. The 250 window lengths yielded the best performance of the prediction algorithm of (mean±SD) root mean square error = 5.68%±1.53% and Person’s correlation = 0.99±0.0059.

Thermal design verification testing of the Clementine spacecraft: Quick, cheap, and useful

NASA Technical Reports Server (NTRS)

Kim, Jeong H.; Hyman, Nelson L.

1994-01-01

At this writing, Clementine had successfully fulfilled its moon-mapping mission; at this reading it will have also, with continued good fortune, taken a close look at the asteroid Geographos. The thermal design that made all this possible was indeed formidable in many respects, with very high ratios of requirements-to-available resources and performance-to-cost and mass. There was no question that a test verification of this quite unique and complex design was essential, but it had to be squeezed into an unyielding schedule and executed with bare-bones cost and manpower. After describing the thermal control subsystem's features, we report all the drama, close-calls, and cost-cutting, how objectives were achieved under severe handicap but (thankfully) with little management and documentation interference. Topics include the newly refurbished chamber (ready just in time), the reality level of the engineering model, using the analytical thermal model, the manner of environment simulation, the hand-scratched film heaters, functioning of all three types of heat pipes (but not all heat pipes), and the BMDO sensors' checkout through the chamber window. Test results revealed some surprises and much valuable data, resulting in thermal model and flight hardware refinements. We conclude with the level of correlation between predictions and both test temperatures and flight telemetry.

Mock Target Window OTR and IR Design and Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wass, Alexander Joseph

In order to fully verify temperature measurements made on the target window using infrared (IR) optical non-contact methods, actual comparative measurements are made with a real beam distribution as the heat source using Argonne National Laboratory’s (ANL) 35 MeV electron accelerator. Using Monte Carlo N-Particle (MCNP) simulations and thermal Finite Element Analysis (FEA), a cooled mock target window with thermocouple implants is designed to be used in such a test to achieve window temperatures up to 700°C. An uncoated and blackcoated mock window is designed to enhance the IR temperature measurements and verify optical transmitted radiation (OTR) imagery. This allowsmore » us to fully verify and characterize our temperature accuracy with our current IR camera method and any future method we may wish to explore using actual production conditions. This test also provides us with valuable conclusions/concerns regarding the calibration method we developed using our IR test stand at TA-53 in MPF-14.« less

The Diamond Window with Boron-Doped Layers for the Output of Microwave Radiation at High Peak and Average Power Levels

NASA Astrophysics Data System (ADS)

Ivanov, O. A.; Kuzikov, S. V.; Vikharev, A. A.; Vikharev, A. L.; Lobaev, M. A.

2017-10-01

We propose a novel design of the barrier window for the output of microwave radiation at high peak and average power levels. A window based on a plate of polycrystalline CVD diamond with thin (nanometer-thick) boron-doped layers with increased conductivity is considered. Such a window, which retains the low radiation loss due to the small total thickness of the conductive layers and the high thermal conductivity inherent in diamond, prevents accumulation of a static charge on its surface, on the one hand, and allows one to produce a static electric field on the surface of the doped layer, which impedes the development of a multipactor discharge, on the other hand. In this case, a high level of the power of the transmitted radiation and a large passband width are ensured by choosing the configuration of the field in the form of a traveling wave inside the window.

Crystallographic Oxide Phase Identification of Char Deposits Obtained from Space Shuttle Columbia Window Debris

NASA Technical Reports Server (NTRS)

Olivas, J. D.; Wright, M. C.; Christoffersen, R.; Cone, D. M.; McDanels, S. J.

2009-01-01

Analyzing the remains of Space Shuttle Columbia has proven technically beneficial years after the vehicle breakup. This investigation focused on charred deposits on fragments of Columbia overhead windowpanes. Results were unexpected relative to the engineering understanding of material performance in a reentry environment. The TEM analysis demonstrated that the oxides of aluminum and titanium mixed with silicon oxides to preserve a history of thermal conditions to which portions of the vehicle were exposed. The presence of Ti during the beginning of the deposition process, along with the thermodynamic phase precipitation upon cool down, indicate that temperatures well above the Ti melt point were experienced. The stratified observations implied that additional exothermic reaction, expectedly metal combustion of a Ti structure, had to be present for oxide formation. Results are significant for aerospace vehicles where thermal protection system (TPS) breaches cause substructures to be in direct path with the reentry plasma. 1

Design and development of a 6 MW peak, 24 kW average power S-band klystron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, L.M.; Meena, Rakesh; Nangru, Subhash

2011-07-01

A 6 MW peak, 24 kW average power S-band Klystron is under development at CEERI, Pilani under an MoU between BARC and CEERI. The design of the klystron has been completed. The electron gun has been designed using TRAK and MAGIC codes. RF cavities have been designed using HFSS and CST Microwave Studio while the complete beam wave interaction simulation has been done using MAGIC code. The thermal design of collector and RF window has been done using ANSYS code. A Gun Collector Test Module (GCTM) was developed before making actual klystron to validate gun perveance and thermal design ofmore » collector. A high voltage solid state pulsed modulator has been installed for performance valuation of the tube. The paper will cover the design aspects of the tube and experimental test results of GCTM and klystron. (author)« less

Design of the thermal insulating test system for doors and windows of buildings

NASA Astrophysics Data System (ADS)

Yu, Yan; Qi, Jinqing; Xu, Yunwei; Wu, Hao; Ou, Jinping

2011-04-01

Thermal insulating properties of doors and widows are important parameter to measure the quality of windows and doors. This paper develops the thermal insulating test system of doors and windows for large temperature difference in winter in north of China according to national standards. This system is integrated with temperature measurement subsystem, temperature control subsystem, the heating power measurement subsystem, and heat transfer coefficient calculated subsystem. The temperature measurement subsystem includes temperature sensor which is implemented by sixty-four thermocouple sensors to measure the key positions of cold room and hot room, and the temperature acquisition unit which adopts Agilent 34901A data acquisition card to achieve self-compensation and accurate temperature capture. The temperature control subsystem including temperature controller and compressor system is used to control the temperature between 0 degree to 20 degree for hot room and -20 degree to 0 degree for cold room. The hot room controller uses fuzzy control algorithm to achieve accurate control of temperature and the cold room controller firstly uses compressor to achieve coarse control and then uses more accurate temperature controller unit to obtain constant temperature(-20 degree). The heating power measurement is mainly to get the heat power of hot room heating devices. After above constant temperature environment is constructed, software of the test system is developed. Using software, temperature data and heat power data can be accurately got and then the heat transfer coefficient, representing the thermal insulating properties of doors and widows, is calculated using the standard formula. Experimental results show that the test system is simple, reliable and precise. It meets the testing requirements of national standard and has a good application prospect.

An orbiting multispectral scanner for overland and oceanographic applications.

NASA Technical Reports Server (NTRS)

Peacock, K.; Withrington, R. J.

1971-01-01

Description of the major features of a multispectral scanner designed to perform overland and oceanographic surveys from space. The instrument uses an image plane conical scanner and contains independent spectrometers for land and ocean applications. The overland spectrometer has a spatial resolution of 200 ft and has six spectral bands in the atmospheric windows between 0.5 and 2.4 microns. The oceanographic spectrometer has a spatial resolution of 1200 ft and possesses 24 spectral bands equally spaced and in registration over the wavelength range from 0.4 to 0.8 micron. A thermal band of 600-ft resolution is used with a spectral range from 10.5 to 12.6 microns. The swath width of the scan is 100 nautical miles from an altitude of 500 nautical miles. The system has two modes of operation which are selectable by ground command. The six bands of overland data plus the thermal band data can be transmitted, or the 24 bands of oceanographic data plus data from two of the overland bands and the thermal band can be transmitted. The performance is described by the minimum detectable reflectance difference and the effects of sun angle and target reflectivity variations are discussed. The sensitivity is related to the variation of the ocean reflectivity in the presence of chlorophyll and to typical agricultural targets.

Multidisciplinary Tool for Systems Analysis of Planetary Entry, Descent, and Landing

NASA Technical Reports Server (NTRS)

Samareh, Jamshid A.

2011-01-01

Systems analysis of a planetary entry (SAPE), descent, and landing (EDL) is a multidisciplinary activity in nature. SAPE improves the performance of the systems analysis team by automating and streamlining the process, and this improvement can reduce the errors that stem from manual data transfer among discipline experts. SAPE is a multidisciplinary tool for systems analysis of planetary EDL for Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Titan. It performs EDL systems analysis for any planet, operates cross-platform (i.e., Windows, Mac, and Linux operating systems), uses existing software components and open-source software to avoid software licensing issues, performs low-fidelity systems analysis in one hour on a computer that is comparable to an average laptop, and keeps discipline experts in the analysis loop. SAPE uses Python, a platform-independent, open-source language, for integration and for the user interface. Development has relied heavily on the object-oriented programming capabilities that are available in Python. Modules are provided to interface with commercial and government off-the-shelf software components (e.g., thermal protection systems and finite-element analysis). SAPE currently includes the following analysis modules: geometry, trajectory, aerodynamics, aerothermal, thermal protection system, and interface for structural sizing.

Comparison of 808, 980, and 1075nm lasers for noninvasive thermal coagulation of the canine vas deferens, ex vivo

NASA Astrophysics Data System (ADS)

Cilip, Christopher M.; Schweinsberger, Gino R.; Fried, Nathaniel M.

2011-03-01

Successful noninvasive laser coagulation of the canine vas deferens, in vivo, has been previously reported. However, the therapeutic window for treatment is relatively narrow. This study determines the dependence of vas thermal coagulation on laser wavelength for development of a noninvasive laser vasectomy procedure. Noninvasive laser coagulation of canine vas tissue, ex vivo, was performed using three commonly available near-infrared laser wavelengths: 808, 980, and 1075 nm. Each laser delivered an average power of 9.2 W, 500-ms pulse duration, pulse rate of 1.0-Hz, and 3.2-mm diameter laser spot, synchronized with cryogen spray cooling of the scrotal skin surface for a total treatment time of 60 s. Vas burst pressures were measured to determine strength of vas closure and compared to previously reported ejaculation pressures. Gross inspection of vas and scrotal skin was also performed immediately after the procedure as an indicator of thermal coagulation and skin burns. The 1075 nm laser produced the highest vas burst pressures (288 +/- 28 mmHg), significantly greater than previously reported ejaculation pressures (136 +/- 29 mmHg). The 808 nm wavelength produced insufficient vas burst pressures of 141 +/- 61 mmHg, and minor scrotal skin burns were observed in at least one case. The 980 nm wavelength was unable to produce thermal coagulation of the vas, with low burst pressures (89 +/- 58 mmHg) and severe scrotal skin burns. The 1075 nm wavelength was the only near-IR wavelength that consistently thermally coagulated the vas with a strong degree of closure and without any scrotal skin burns.

HPC in a HEP lab: lessons learned from setting up cost-effective HPC clusters

NASA Astrophysics Data System (ADS)

Husejko, Michal; Agtzidis, Ioannis; Baehler, Pierre; Dul, Tadeusz; Evans, John; Himyr, Nils; Meinhard, Helge

2015-12-01

In this paper we present our findings gathered during the evaluation and testing of Windows Server High-Performance Computing (Windows HPC) in view of potentially using it as a production HPC system for engineering applications. The Windows HPC package, an extension of Microsofts Windows Server product, provides all essential interfaces, utilities and management functionality for creating, operating and monitoring a Windows-based HPC cluster infrastructure. The evaluation and test phase was focused on verifying the functionalities of Windows HPC, its performance, support of commercial tools and the integration with the users work environment. We describe constraints imposed by the way the CERN Data Centre is operated, licensing for engineering tools and scalability and behaviour of the HPC engineering applications used at CERN. We will present an initial set of requirements, which were created based on the above constraints and requests from the CERN engineering user community. We will explain how we have configured Windows HPC clusters to provide job scheduling functionalities required to support the CERN engineering user community, quality of service, user- and project-based priorities, and fair access to limited resources. Finally, we will present several performance tests we carried out to verify Windows HPC performance and scalability.

Evaluation of Energy Efficiency Performance of Heated Windows

NASA Astrophysics Data System (ADS)

Jammulamadaka, Hari Swarup

The study about the evaluation of the performance of the heated windows was funded by the WVU Research Office as a technical assistance award at the 2014 TransTech Energy Business Development Conference to the Green Heated Glass company/project owned by Frank Dlubak. The award supports a WVU researcher to conduct a project important for commercialization. This project was awarded to the WVU Industrial Assessment Center in 2015. The current study attempted to evaluate the performance of the heated windows by developing an experimental setup to test the window at various temperatures by varying the current input to the window. The heated double pane window was installed in an insulated box. A temperature gradient was developed across the window by cooling one side of the window using gel based ice packs. The other face of the window was heated by passing current at different wattages through the window. The temperature of the inside and outside panes, current and voltage input, room and box temperature were recorded, and used to calculate the apparent R-value of the window when not being heated vs when being heated. It has been concluded from the study that the heated double pane window is more effective in reducing heat losses by as much as 50% than a non-heated double pane window, if the window temperature is maintained close to the room temperature. If the temperature of the window is much higher than the room temperature, the losses through the window appear to increase beyond that of a non-heated counterpart. The issues encountered during the current round of experiments are noted, and recommendations provided for future studies.

Ocean warming and acidification: Unifying physiological principles linking organism response to ecosystem change?

NASA Astrophysics Data System (ADS)

Pörtner, H. O.; Bock, C.; Lannig, G.; Lucassen, M.; Mark, F. C.; Stark, A.; Walther, K.; Wittmann, A.

2011-12-01

The effects of ocean warming and acidification on individual species of marine ectothermic animals may be based on some common denominators, i.e. physiological responses that can be assumed to reflect unifying principles, common to all marine animal phyla. Identification of these principles requires studies, which reach beyond the species-specific response, and consider multiple stressors, for example temperature, CO2 or extreme hypoxia. Analyses of response and acclimation include functional traits of physiological performance on various levels of biological organisation, from changes in the transcriptome to patterns of acid-base regulation and whole animal thermal tolerance. Conclusions are substantiated by comparisons of species and phyla from temperate, Arctic and Antarctic ecosystems and also benefit from the interpretation of paleo-patterns based on the use of a unifying physiological concept, suitable to integrate relevant environmental factors into a more comprehensive picture. Studying the differential specialization of animals on climate regimes and their sensitivity to climate leads to improved understanding of ongoing and past ecosystem change and should then support more reliable projections of future scenarios. For example, accumulating CO2 causes disturbances in acid-base status. Resilience to ocean acidification may be reflected in the capacity to compensate for these disturbances or their secondary effects. Ion and pH regulation comprise thermally sensitive active and passive transfer processes across membranes. Specific responses of ion transporter genes and their products to temperature and CO2 were found in fish, crustaceans and bivalves. However, compensation may cause unfavourable shifts in energy budget and beyond that hamper cellular and mitochondrial metabolism, which are directly linked to the animal's aerobic performance window. In crabs, oysters and, possibly, fishes, a narrowing of the thermal window is caused by moderate increases in CO2 levels. Furthermore, a decrease in the efficiency of energy production may occur and affect growth and fitness as well as larval development. Different sensitivities of life history stages indicate physiologically sensitive bottlenecks during the life cycle of marine organisms. Available evidence suggests that the concept of oxygen and capacity limited thermal tolerance (OCLTT) provides access to the physiological mechanisms closely defining the sensitivities and responses of species to various stressors. It provides causality and quantifies the levels and changes of performance and resistance, and supports more realistic estimates of species and ecosystem sensitivities to environmental change. The emerging picture of differential sensitivities across animal phyla is in line with existing categorizations of sensitivities from palaeo-observations during the Permian-Triassic mass extinctions (A.H. Knoll et al., Earth and Planetary Science Letters 256, 295-313, 2007).

How Building Systems Affect Worker Wellness

DTIC Science & Technology

1994-03-01

spatial configuration must strike a balance between the objective needs of the organization and the more subjective human ingredient. Good building...sense, building design for thermal comfort involves a balance between the building’s orientation, its windowing scheme, the use of thermal mass, and the...stated above. An improved quality of worklife and a humanized work environment are psychological incentives that can increase productivity. Worker specific

47 CFR 15.323 - Specific requirements for devices operating in the 1920-1930 MHz sub-band.

Code of Federal Regulations, 2011 CFR

2011-10-01

... monitoring threshold must not be more than 30 dB above the thermal noise power for a bandwidth equivalent to... windows with the lowest power level below a monitoring threshold of 50 dB above the thermal noise power... of 20 °C. For equipment that is capable only of operating from a battery, the frequency stability...

Applying Fused Silica and Other Transparent Window Materials in Aerospace Applications

NASA Technical Reports Server (NTRS)

Salem, Jon

2017-01-01

A variety of transparent ceramics, such as AlONs and spinels, that were developed for military applications hold promise as spacecraft windows. Window materials in spacecraft such as the Space Shuttle must meet many requirements such as maintaining cabin pressure, sustaining thermal shock, and tolerating damage from hyper-velocity impact while providing superior optical characteristics. The workhorse transparent material for space missions from Apollo to the International Space Station has been fused silica due in part to its low density, low coefficient of expansion and optical quality. Despite its successful use, fused silica exhibits lower fracture toughness and impact resistance as compared to newer materials. Can these newer transparent ceramics lighten spacecraft window systems and might they be useful for applications such as phone screens? This presentation will compare recent optical ceramics to fused silica and demonstrate how weight can be saved.

New energy venture: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Three nonprofit WAP subgrantees in Arkansas that currently manufacture storm windows, thermal doors and thermal windows on a limited basis for sale to the public and for use in the weatherization programs intend to form NEW ENERGY VENTURES (NEV) a for-profit entity that will market their products and products from other manufacturers that complement these WAP subgrantee produced products. Participating in the venture are East Central Arkansas Economic Opportunity Corp., Forrest City, AR; Universal Housing Development Corp., Dardanelle, AR; and Southwest Arkansas Development Council, Inc., Texarkana, AR. Because of the location of the agencies throughout Arkansas, the products could reasonablymore » be sold to individuals and businesses in the proximate areas of the neighboring states without remarkably increasing the cost of doing business. This assumption, however, will be tested during the business planning period.« less

Sunlight Responsive Thermochromic Window System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Millett, F,A; Byker,H, J

2006-10-27

Pleotint has embarked on a novel approach with our Sunlight Responsive Thermochromic, SRT™, windows. We are integrating dynamic sunlight control, high insulation values and low solar heat gain together in a high performance window. The Pleotint SRT window is dynamic because it reversibly changes light transmission based on thermochromics activated directly by the heating effect of sunlight. We can achieve a window package with low solar heat gain coefficient (SHGC), a low U value and high insulation. At the same time our windows provide good daylighting. Our innovative window design offers architects and building designers the opportunity to choose theirmore » desired energy performance, excellent sound reduction, external pane can be self-cleaning, or a resistance to wind load, blasts, bullets or hurricanes. SRT windows would provide energy savings that are estimated at up to 30% over traditional window systems. Glass fabricators will be able to use existing equipment to make the SRT window while adding value and flexibility to the basic design. Glazing installers will have the ability to fit the windows with traditional methods without wires, power supplies and controllers. SRT windows can be retrofit into existing buildings,« less

Heat transfer to a heavy liquid metal in curved geometry: Code validation and CFD simulation for the MEGAPIE lower target

NASA Astrophysics Data System (ADS)

Dury, Trevor V.

2006-06-01

The ESS and SINQ Heat Emitting Temperature Sensing Surface (HETSS) mercury experiments have been used to validate the Computational Fluid Dynamics (CFD) code CFX-4 employed in designing the lower region of the international liquid metal cooled MEGAPIE target, to be installed at SINQ, PSI, in 2006. Conclusions were drawn on the best turbulence models and degrees of mesh refinement to apply, and a new CFD model of the MEGAPIE geometry was made, based on the CATIA CAD design of the exact geometry constructed. This model contained the fill and drain tubes as well as the bypass feed duct, with the differences in relative vertical length due to thermal expansion being considered between these tubes and the window. Results of the mercury experiments showed that CFD calculations can be trusted to give peak target window temperature under normal operational conditions to within about ±10%. The target nozzle actually constructed varied from the theoretical design model used for CFD due to the need to apply more generous separation distances between the nozzle and the window. In addition, the bypass duct contraction approaching the nozzle exit was less sharp compared with earlier designs. Both of these changes modified the bypass jet penetration and coverage of the heated window zone. Peak external window temperature with a 1.4 mA proton beam and steady-state operation is now predicted to be 375 °C, with internal temperature 354.0 °C (about 32 °C above earlier predictions). Increasing bypass flow from 2.5 to 3.0 kg/s lowers these peak temperatures by about 12 °C. Stress analysis still needs to be made, based on these thermal data.

Characterization of lithium fluoride windows at 450 K for shock wave experiments: Hugoniot curves and refractive index at 532 nm

NASA Astrophysics Data System (ADS)

Fraizier, E.; Antoine, P.; Godefroit, J.-L.; Lanier, G.; Roy, G.; Voltz, C.

Lithium fluoride (LiF) windows are extensively used in traditional shock wave experiments because of their transparency beyond 100 GPa along [100] axis. A correct knowledge of the optical and mechanical properties of these windows is essential in order to analyze the experimental data and to determine the equation of state on a large variety of metals. This in mind, the windows supply is systematically characterized in order to determine the density, the thermal expansion and the crystalline orientation. Furthermore, an experimental campaign is conducted in order to characterize the windows properties under shock loading at 300 K and preheated conditions (450 K). This article describes the experiments, details the analysis and presents the results. Particle velocity measurements are carried out at the interface of a multiple windows stack using interferometer diagnostic (VISAR and IDL) at 532 nm wavelength. Shock velocity is calculated as a function of the time of flight through each window. The optical correction is calculated as the ratio of the apparent velocity gap and the particle velocity at the free surface. To go further, the Rankine-Hugoniot relations are applied to calculate the pressure and the density. Then, the results and uncertainties are presented and compared with literature data.

Microwave window breakdown experiments and simulations on the UM/L-3 relativistic magnetron

NASA Astrophysics Data System (ADS)

Hoff, B. W.; Mardahl, P. J.; Gilgenbach, R. M.; Haworth, M. D.; French, D. M.; Lau, Y. Y.; Franzi, M.

2009-09-01

Experiments have been performed on the UM/L-3 (6-vane, L-band) relativistic magnetron to test a new microwave window configuration designed to limit vacuum side breakdown. In the baseline case, acrylic microwave windows were mounted between three of the waveguide coupling cavities in the anode block vacuum housing and the output waveguides. Each of the six 3 cm deep coupling cavities is separated from its corresponding anode cavity by a 1.75 cm wide aperture. In the baseline case, vacuum side window breakdown was observed to initiate at single waveguide output powers close to 20 MW. In the new window configuration, three Air Force Research Laboratory-designed, vacuum-rated directional coupler waveguide segments were mounted between the coupling cavities and the microwave windows. The inclusion of the vacuum side power couplers moved the microwave windows an additional 30 cm away from the anode apertures. Additionally, the Lucite microwave windows were replaced with polycarbonate windows and the microwave window mounts were redesigned to better maintain waveguide continuity in the region around the microwave windows. No vacuum side window breakdown was observed in the new window configuration at single waveguide output powers of 120+MW (a factor of 3 increase in measured microwave pulse duration and factor of 3 increase in measured peak power over the baseline case). Simulations were performed to investigate likely causes for the window breakdown in the original configuration. Results from these simulations have shown that in the original configuration, at typical operating voltage and magnetic field ranges, electrons emitted from the anode block microwave apertures strike the windows with a mean kinetic energy of 33 keV with a standard deviation of 14 keV. Calculations performed using electron impact angle and energy data predict a first generation secondary electron yield of 65% of the primary electron population. The effects of the primary aperture electron impacts, combined with multiplication of the secondary populations, were determined to be the likely causes of the poor microwave window performance in the original configuration.

Regional and circadian variations of sweating rate and body surface temperature in camels (Camelus dromedarius).

PubMed

Abdoun, Khalid A; Samara, Emad M; Okab, Aly B; Al-Haidary, Ahmed A

2012-07-01

It was the aim of this study to investigate the regional variations in surface temperature and sweating rate and to visualize body thermal windows responsible for the dissipation of excess body heat in dromedary camels. This study was conducted on five dromedary camels with mean body weight of 450 ± 20.5 kg and 2 years of age. Sweating rate, skin and body surface temperature showed significant (P < 0.001) circadian variation together with the variation in ambient temperature. However, daily mean values of sweating rate, skin and body surface temperature measured on seven regions of the camel body did not significantly differ. The variation in body surface temperature compared to the variation in skin temperature was higher in the hump compared to the axillary and flank regions, indicating the significance of camel's fur in protecting the skin from daily variation in ambient temperature. Infrared thermography revealed that flank and axillary regions had lower thermal gradients at higher ambient temperature (T(a) ) and higher thermal gradients at lower T(a) , which might indicate the working of flank and axillary regions as thermal windows dissipating heat during the night. Sweating rate showed moderate correlation to skin and body surface temperatures, which might indicate their working as potential thermal drivers of sweating in camels. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

Thermal biology of the sub-polar–temperate estuarine crab Hemigrapsus crenulatus (Crustacea: Decapoda: Varunidae)

PubMed Central

Cumillaf, Juan P.; Blanc, Johnny; Paschke, Kurt; Gebauer, Paulina; Díaz, Fernando; Re, Denisse; Chimal, María E.; Vásquez, Jorge; Rosas, Carlos

2016-01-01

ABSTRACT Optimum temperatures can be measured through aerobic scope, preferred temperatures or growth. A complete thermal window, including optimum, transition (Pejus) and critical temperatures (CT), can be described if preferred temperatures and CT are defined. The crustacean Hemigrapsus crenulatus was used as a model species to evaluate the effect of acclimation temperature on: (i) thermal preference and width of thermal window, (ii) respiratory metabolism, and (iii) haemolymph proteins. Dependant on acclimation temperature, preferred temperature was between 11.8°C and 25.2°C while CT was found between a minimum of 2.7°C (CTmin) and a maximum of 35.9°C (CTmax). These data and data from tropical and temperate crustaceans were compared to examine the association between environmental temperature and thermal tolerance. Temperate species have a CTmax limit around 35°C that corresponded with the low CTmax limit of tropical species (34–36°C). Tropical species showed a CTmin limit around 9°C similar to the maximum CTmin of temperate species (5–6°C). The maximum CTmin of deep sea species that occur in cold environments (2.5°C) matched the low CTmin values (3.2°C) of temperate species. Results also indicate that the energy required to activate the enzyme complex (Ei) involved in respiratory metabolism of ectotherms changes along the latitudinal gradient of temperature. PMID:26879464

Simultaneous measurement of the dynamic emissivity and the radiance of the shocked Al/LiF interface in the near-infrared wavelength

NASA Astrophysics Data System (ADS)

Liu, Shenggang; Li, Jiabo; Li, Jun; Xue, Tao; Tao, Tianjiong; Ma, Heli; Wang, Xiang; Weng, Jidong; Li, Zeren

2018-04-01

A novel method based on signal superimposing has been presented to simultaneously measure the dynamic emissivity and the radiance of a shocked sample/window interface in the near-infrared wavelength. In this method, we have used three rectangle laser pulses to illuminate the sample/window interface via an integrating sphere and expect that the reflected laser pulses from the sample/window interface can be superimposed on its thermal radiation at the shocked steady state by time precision synchronization. In the two proving trials, the second laser pulse reflected from the Al/LiF interface has been successfully superimposed on its thermal radiation despite large flyer velocity uncertainty. The dynamic emissivity and the radiance at 1064 nm have been obtained simultaneously from the superimposing signals. The obtained interface temperatures are 1842 ± 82 K and 1666 ± 154 K, respectively, the corresponding release pressures are 65.7 GPa and 62.6 GPa, and the deduced Hugonoit temperatures are consistent with the theoretical calculations. In comparison, the fitting temperatures from the gray body model are 300-500 K higher than our experimental measurement results and the theoretical calculations.

Fluctuations and QCD phase structure

NASA Astrophysics Data System (ADS)

Kitazawa, Masakiyo

2014-11-01

Fluctuation observables are invaluable tools in relativistic heavy ion collisions to investigate primordial thermodynamics of fireballs. Active experimental measurements have been performed at RHIC and LHC. In particular, interesting experimental results were recently reported on the electric charge fluctuation at ALICE and on the higher order cumulants at STAR, which show nontrivial behaviors reflecting non-hadronic and/or non-thermal physics. We argue that more detailed understanding on these observables are needed to use them effectively in the analysis of QCD phase structure. We suggest that the measurement of various cumulants of conserved charges including baryon number and their rapidity window dependence will provide important information needed for making progress in this subject.

Study of the effect of ZnO film on some properties of clear and color window glass

NASA Astrophysics Data System (ADS)

Hamead, Alaa A. Abdul; Ahmed, Sura S.; Khdheer, Mena F.

2018-05-01

In the current research, a samples of transparent color and colorless window glass were prepared, (includes metal transition oxides) for construction applications. A nano-film layer of zinc oxide ZnO was deposited by spray pyrolysis technique for use in sustainability applications prepared. Structural properties (x-ray diffraction XRD, scanning electron microscopy SEM and atomic force microscopy AFM), and thermal properties, as well as optical properties and the effect of weathering conditions on applied film on clear and colored glass were examined. The results showed that the deposition film had a thickness of less than 90nm and that it was crystallized with high optical transparently, that was not significantly affected after deposited the ZnO nano film. While thermal insulation decreased significantly after deposition, and the effect of the weather conditions was very low as the ZnO coating was not affected, as the thermal insulation did not change after exposure to accelerated air conditions. Make it suitable in glass applications for buildings in vertical construction.

Window acoustic study for advanced turboprop aircraft

NASA Technical Reports Server (NTRS)

Prydz, R. A.; Balena, F. J.

1984-01-01

An acoustic analysis was performed to establish window designs for advanced turboprop powered aircraft. The window transmission loss requirements were based on A-weighted interior noise goals of 80 and 75 dBA. The analytical results showed that a triple pane window consisting of two glass outer panes and an inner pane of acrylic would provide the required transmission loss and meet the sidewall space limits. Two window test articles were fabricated for laboratory evaluation and verification of the predicted transmission loss. Procedures for performing laboratory tests are presented.

Interferometric phase measurement of zerodur, aluminum and SXA mirrors at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Magner, Thomas J.; Barney, Richard D.

1988-01-01

A research program was undertaken to determine the surface figure error of several different types of mirrors at cryogenic temperatures. Two-inch diameter parabolic, spherical and flat mirrors were fabricated from zerodur, aluminum and a metal matrix composite of silicon carbide reinforced aluminum (SXA). The ratio of silicon carbide to aluminum was selected so that the coefficient of thermal expansion (CTE) of the metal matrix matched electroless nickel. A liquuid helium dewar was modified to add an interferometric grade window, a cold electronic shutter and a strain-free copper mirror mount. Interferometric phase measurements on each mirror mounted in the dewar were made without the window, with the window, under vacuum, at around 80K and between 10K and 24K.

Flash Memory Featuring Low-Voltage Operation by Crystalline ZrTiO4 Charge-Trapping Layer

NASA Astrophysics Data System (ADS)

Shen, Yung-Shao; Chen, Kuen-Yi; Chen, Po-Chun; Chen, Teng-Chuan; Wu, Yung-Hsien

2017-03-01

Crystalline ZrTiO4 (ZTO) in orthorhombic phase with different plasma treatments was explored as the charge-trapping layer for low-voltage operation flash memory. For ZTO without any plasma treatment, even with a high k value of 45.2, it almost cannot store charges due the oxygen vacancies-induced shallow-level traps that make charges easy to tunnel back to Si substrate. With CF4 plasma treatment, charge storage is still not improved even though incorporated F atoms could introduce additional traps since the F atoms disappear during the subsequent thermal annealing. On the contrary, nevertheless the k value degrades to 40.8, N2O plasma-treated ZTO shows promising performance in terms of 5-V hysteresis memory window by ±7-V sweeping voltage, 2.8-V flatband voltage shift by programming at +7 V for 100 μs, negligible memory window degradation with 105 program/erase cycles and 81.8% charge retention after 104 sec at 125 °C. These desirable characteristics are ascribed not only to passivation of oxygen vacancies-related shallow-level traps but to introduction of a large amount of deep-level bulk charge traps which have been proven by confirming thermally excited process as the charge loss mechanism and identifying traps located at energy level beneath ZTO conduction band by 0.84 eV~1.03 eV.

Flash Memory Featuring Low-Voltage Operation by Crystalline ZrTiO4 Charge-Trapping Layer.

PubMed

Shen, Yung-Shao; Chen, Kuen-Yi; Chen, Po-Chun; Chen, Teng-Chuan; Wu, Yung-Hsien

2017-03-08

Crystalline ZrTiO 4 (ZTO) in orthorhombic phase with different plasma treatments was explored as the charge-trapping layer for low-voltage operation flash memory. For ZTO without any plasma treatment, even with a high k value of 45.2, it almost cannot store charges due the oxygen vacancies-induced shallow-level traps that make charges easy to tunnel back to Si substrate. With CF 4 plasma treatment, charge storage is still not improved even though incorporated F atoms could introduce additional traps since the F atoms disappear during the subsequent thermal annealing. On the contrary, nevertheless the k value degrades to 40.8, N 2 O plasma-treated ZTO shows promising performance in terms of 5-V hysteresis memory window by ±7-V sweeping voltage, 2.8-V flatband voltage shift by programming at +7 V for 100 μs, negligible memory window degradation with 10 5 program/erase cycles and 81.8% charge retention after 10 4  sec at 125 °C. These desirable characteristics are ascribed not only to passivation of oxygen vacancies-related shallow-level traps but to introduction of a large amount of deep-level bulk charge traps which have been proven by confirming thermally excited process as the charge loss mechanism and identifying traps located at energy level beneath ZTO conduction band by 0.84 eV~1.03 eV.

High Reliability R-10 Windows Using Vacuum Insulating Glass Units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stark, David

2012-08-16

The objective of this effort was for EverSealed Windows (“EverSealed” or “ESW”) to design, assemble, thermally and environmentally test and demonstrate a Vacuum Insulating Glass Unit (“VIGU” or “VIG”) that would enable a whole window to meet or exceed the an R-10 insulating value (U-factor ≤ 0.1). To produce a VIGU that could withstand any North American environment, ESW believed it needed to design, produce and use a flexible edge seal system. This is because a rigid edge seal, used by all other know VIG producers and developers, limits the size and/or thermal environment of the VIG to where themore » unit is not practical for typical IG sizes and cannot withstand severe outdoor environments. The rigid-sealed VIG’s use would be limited to mild climates where it would not have a reasonable economic payback when compared to traditional double-pane or triple-pane IGs. ESW’s goals, in addition to achieving a sufficiently high R-value to enable a whole window to achieve R-10, included creating a VIG design that could be produced for a cost equal to or lower than a traditional triple-pane IG (low-e, argon filled). ESW achieved these goals. EverSealed produced, tested and demonstrated a flexible edge-seal VIG that had an R-13 insulating value and the edge-seal system durability to operate reliably for at least 40 years in the harshest climates of North America.« less

Innovative ceramic slab lasers for high power laser applications

NASA Astrophysics Data System (ADS)

Lapucci, Antonio; Ciofini, Marco

2005-09-01

Diode Pumped Solid State Lasers (DPSSL) are gaining increasing interest for high power industrial application, given the continuous improvement in high power diode laser technology reliability and affordability. These sources open new windows in the parameter space for traditional applications such as cutting , welding, marking and engraving for high reflectance metallic materials. Other interesting applications for this kind of sources include high speed thermal printing, precision drilling, selective soldering and thin film etching. In this paper we examine the most important DPSS laser source types for industrial applications and we describe in details the performances of some slab laser configurations investigated at our facilities. The different architectures' advantages and draw-backs are briefly compared in terms of performances, system complexity and ease of scalability to the multi-kW level.

MEMS device for spacecraft thermal control applications

NASA Technical Reports Server (NTRS)

Swanson, Theordore D. (Inventor)

2003-01-01

A micro-electromechanical device that comprises miniaturized mechanical louvers, referred to as Micro Electro-Mechanical Systems (MEMS) louvers are employed to achieve a thermal control function for spacecraft and instruments. The MEMS louvers are another form of a variable emittance control coating and employ micro-electromechanical technology. In a function similar to traditional, macroscopic thermal louvers, the MEMS louvers of the present invention change the emissivity of a surface. With the MEMS louvers, as with the traditional macroscopic louvers, a mechanical vane or window is opened and closed to allow an alterable radiative view to space.

LaF3 core/shell nanoparticles for subcutaneous heating and thermal sensing in the second biological-window

NASA Astrophysics Data System (ADS)

Ximendes, Erving Clayton; Rocha, Uéslen; Kumar, Kagola Upendra; Jacinto, Carlos; Jaque, Daniel

2016-06-01

We report on Ytterbium and Neodymium codoped LaF3 core/shell nanoparticles capable of simultaneous heating and thermal sensing under single beam infrared laser excitation. Efficient light-to-heat conversion is produced at the Neodymium highly doped shell due to non-radiative de-excitations. Thermal sensing is provided by the temperature dependent Nd3+ → Yb3+ energy transfer processes taking place at the core/shell interface. The potential application of these core/shell multifunctional nanoparticles for controlled photothermal subcutaneous treatments is also demonstrated.

BERKELEY LAB WINDOW

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curcija, Dragan Charlie; Zhu, Ling; Czarnecki, Stephen

WINDOW features include: - Microsoft Windows TM interface - algorithms for the calculation of total fenestration product U-values and Solar Heat Gain Coefficient consistent with ASHRAE SPC 142, ISO 15099, and the National Fenestration Rating Council - a Condensation Resistance Index in accordance with the NFRC 500 Standard - and integrated database of properties - imports data from other LBNL window analysis software: - Import THERM file into the Frame Library - Import records from IGDB and OPtics5 into the Glass Library for the optical properties of coated and uncoated glazings, laminates, and applied films. Program Capabilities WINDOW 7.2 offersmore » the following features: The ability to analyze products made from any combination of glazing layers, gas layers, frames, spacers, and dividers under any environmental conditions and at any tilt; The ability to model complex glazing systems such as venetian blinds and roller shades. Directly accessible libraries of window system components, (glazing systems, glazing layers, gas fills, frame and divider elements), and environmental conditions; The choice of working in English (IP), or Systeme International (SI) units; The ability to specify the dimensions and thermal properties of each frame element (header, sills, jamb, mullion) in a window; A multi-band (wavelength-by-wavelength) spectral model; A Glass Library which can access spectral data files for many common glazing materials from the Optics5database; A night-sky radiative model; A link with the DOE-2.1E and Energy Plus building energy analysis program. Performance Indices and Other Results For a user-defined fenestration system and user-defined environmental conditions, WINDOW calculates: The U-value, solar heat gain coefficient, shading coefficient, and visible transmittance for the complete window system; The U-value, solar heat gain coefficient, shading coefficient, and visible transmittance for the glazing system (center-of-glass values); The U-values of the frame and divider elements and corresponding edge-of-glass areas (based on generic correlations); The total solar and visible transmittance and reflectances of the glazing system. Color properties, i.e. L*, a*, and b* color coordinates, dominant wavelength, and purity for transmitted and reflected (outdoor) solar radiation; The damage-weighted transmittance of the glazing system between 0.3 an 0.38 microns; The angular dependence of the solar and visible transmittances, solar and visible reflectances, solar absorptance, and solar heat gain coefficient of the glazing system; The percent relative humidity of the inside and outside air for which condensation will occur on the interior and exterior glazing surfaces respectively; The center-of-glass temperature distribution.« less

Non-Maxwellian Analysis of the Transition-region Line Profiles Observed by the Interface Region Imaging Spectrograph

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dudík, Jaroslav; Dzifčáková, Elena; Polito, Vanessa

2017-06-10

We investigate the nature of the spectral line profiles for transition-region (TR) ions observed with the Interface Region Imaging Spectrograph (IRIS) . In this context, we analyzed an active-region observation performed by IRIS in its 1400 Å spectral window. The TR lines are found to exhibit significant wings in their spectral profiles, which can be well fitted with a non-Maxwellian κ distribution. The fit with a κ distribution can perform better than a double-Gaussian fit, especially for the strongest line, Si iv 1402.8 Å. Typical values of κ found are about 2, occurring in a majority of spatial pixels wheremore » the TR lines are symmetric, i.e., the fit can be performed. Furthermore, all five spectral lines studied (from Si iv, O iv, and S iv) appear to have the same full-width at half-maximum irrespective of whether the line is an allowed or an intercombination transition. A similar value of κ is obtained for the electron distribution by the fitting of the line intensities relative to Si iv 1402.8 Å, if photospheric abundances are assumed. The κ distributions, however, do not remove the presence of non-thermal broadening. Instead, they actually increase the non-thermal width. This is because, for κ distributions, TR ions are formed at lower temperatures. The large observed non-thermal width lowers the opacity of the Si iv line sufficiently enough for this line to become optically thin.« less

Validating computational predictions of night-time ventilation in Stanford's Y2E2 building

NASA Astrophysics Data System (ADS)

Chen, Chen; Lamberti, Giacomo; Gorle, Catherine

2017-11-01

Natural ventilation can significantly reduce building energy consumption, but robust design is a challenging task. We previously presented predictions of natural ventilation performance in Stanford's Y2E2 building using two models with different levels of fidelity, embedded in an uncertainty quantification framework to identify the dominant uncertain parameters and predict quantified confidence intervals. The results showed a slightly high cooling rate for the volume-averaged temperature, and the initial thermal mass temperature and window discharge coefficients were found to have an important influence on the results. To further investigate the potential role of these parameters on the observed discrepancies, the current study is performing additional measurements in the Y2E2 building. Wall temperatures are recorded throughout the nightflush using thermocouples; flow rates through windows are measured using hotwires; and spatial variability in the air temperature is explored. The measured wall temperatures are found the be within the range of our model assumptions, and the measured velocities agree reasonably well with our CFD predications. Considerable local variations in the indoor air temperature have been recorded, largely explaining the discrepancies in our earlier validation study. Future work will therefore focus on a local validation of the CFD results with the measurements. Center for Integrated Facility Engineering (CIFE).

Large-scale fabrication of pseudocapacitive glass windows that combine electrochromism and energy storage.

PubMed

Yang, Peihua; Sun, Peng; Chai, Zhisheng; Huang, Langhuan; Cai, Xiang; Tan, Shaozao; Song, Jinhui; Mai, Wenjie

2014-10-27

Multifunctional glass windows that combine energy storage and electrochromism have been obtained by facile thermal evaporation and electrodeposition methods. For example, WO3 films that had been deposited on fluorine-doped tin oxide (FTO) glass exhibited a high specific capacitance of 639.8 F g(-1). Their color changed from transparent to deep blue with an abrupt decrease in optical transmittance from 91.3% to 15.1% at a wavelength of 633 nm when a voltage of -0.6 V (vs. Ag/AgCl) was applied, demonstrating its excellent energy-storage and electrochromism properties. As a second example, a polyaniline-based pseudocapacitive glass was also developed, and its color can change from green to blue. A large-scale pseudocapacitive WO3-based glass window (15×15 cm(2)) was fabricated as a prototype. Such smart pseudocapacitive glass windows show great potential in functioning as electrochromic windows and concurrently powering electronic devices, such as mobile phones or laptops. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Windowed multipole for cross section Doppler broadening

NASA Astrophysics Data System (ADS)

Josey, C.; Ducru, P.; Forget, B.; Smith, K.

2016-02-01

This paper presents an in-depth analysis on the accuracy and performance of the windowed multipole Doppler broadening method. The basic theory behind cross section data is described, along with the basic multipole formalism followed by the approximations leading to windowed multipole method and the algorithm used to efficiently evaluate Doppler broadened cross sections. The method is tested by simulating the BEAVRS benchmark with a windowed multipole library composed of 70 nuclides. Accuracy of the method is demonstrated on a single assembly case where total neutron production rates and 238U capture rates compare within 0.1% to ACE format files at the same temperature. With regards to performance, clock cycle counts and cache misses were measured for single temperature ACE table lookup and for windowed multipole. The windowed multipole method was found to require 39.6% more clock cycles to evaluate, translating to a 7.9% performance loss overall. However, the algorithm has significantly better last-level cache performance, with 3 fewer misses per evaluation, or a 65% reduction in last-level misses. This is due to the small memory footprint of the windowed multipole method and better memory access pattern of the algorithm.

Optimizing the performance of bandpass photon detectors for inverse photoemission: Transmission of alkaline earth fluoride window crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thiede, Christian, E-mail: christian.thiede@uni-muenster.de; Schmidt, Anke B.; Donath, Markus

2015-08-15

Bandpass photon detectors are widely used in inverse photoemission in the isochromat mode at energies in the vacuum-ultraviolet spectral range. The energy bandpass of gas-filled counters is usually formed by the ionization threshold of the counting gas as high-pass filter and the transmission cutoff of an alkaline earth fluoride window as low-pass filter. The transmission characteristics of the window have, therefore, a crucial impact on the detector performance. We present transmission measurements in the vacuum-ultraviolet spectral range for alkaline earth fluoride window crystals in the vicinity of the transmission cutoff as a function of crystal purity, surface finish, surface contamination,more » temperature, and thickness. Our findings reveal that the transmission characteristics of the window crystal and, thus, the detector performance depend critically on these window parameters.« less

Microbolometer spectrometer opens hoist of new applications

NASA Astrophysics Data System (ADS)

Leijtens, J.; Smorenburg, C.; Escudero, I.; Boslooper, E.; Visser, H.; Helden, W. v.; Breussin, F.

2017-11-01

Current Thermal infra red ( 7..14μm) multispectral imager instruments use cryogenically cooled Mercury Cadmium Telluride (MCT or HgCdTe) detectors. This causes the instruments to be bulky, power hungry and expensive. For systems that have medium NETD (Noise Equivalent Temperature Difference) requirements and can operate with high speed optics (<1.5), room temperature microbolometer performance has increased enough to enable people to design multispectral instruments based on this new detector technology. Because microbolometer technology has been driven by the military need for inexpensive, reliable and small thermal imagers, microbolometer based detectors are almost exclusively available in 2D format, and performance is still increasing. Building a spectrometer for the 7 to 12 μm wavelength region using microbolometers has been discarded until now, based on the expected NETD performance. By optimising the throughput of the optical system, and using the latest improvements in detector performance, TNO TPD has been able to design a spectrometer that is able to provide co-registered measurements in the 7 to 12 μm wavelength region yielding acceptable NETD performance. Apart from the usual multispectral imaging, the concept can be used for several other applications, among which imaging in both the 3 to 5 and 7 to 12 μm atmospheric windows at the same time (forest fire detection and military recognisance) or wideband flame analysis (Nox detection in industrial ovens).

The thermoregulatory theory of yawning: what we know from over 5 years of research

PubMed Central

Gallup, Andrew C.; Eldakar, Omar T.

2012-01-01

Over the past 5 years numerous reports have confirmed and replicated the specific brain cooling and thermal window predictions derived from the thermoregulatory theory of yawning, and no study has found evidence contrary to these findings. Here we review the comparative research supporting this model of yawning among homeotherms, while highlighting a recent report showing how the expression of contagious yawning in humans is altered by seasonal climate variation. The fact that yawning is constrained to a thermal window of ambient temperature provides unique and compelling support in favor of this theory. Heretofore, no existing alternative hypothesis of yawning can explain these results, which have important implications for understanding the potential functional role of this behavior, both physiologically and socially, in humans and other animals. In discussion we stress the broader applications of this work in clinical settings, and counter the various criticisms of this theory. PMID:23293583

Optical Radiation from Shock-Compressed Materials. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Svendsen, Robert F., Jr.

1987-01-01

Recent observations of shock-induced radiation from oxides, silicates, and metals of geophysical interest constrain the shock-compressed temperature of these materials. The relationships between the temperature inferred from the observed radiation and the temperature of the shock-compressed film or foil and/or window were investigated. Changes of the temperature field in each target component away from that of their respective shock-compressed states occur because of: shock-impedance mismatch between target components; thermal mismatch between target components; surface roughness at target interfaces; and conduction within and between target components. In particular, conduction may affect the temperature of the film/foil window interface on the time scale of the experiments, and so control the intensity and history of the dominant thermal radiation sources in the target. This type of model was used to interpret the radiation emitted by a variety of shock-compressed materials and interfaces.

Transport properties of LiF under strong compression: modeling using advanced electronic structure methods and classical molecular dynamics

NASA Astrophysics Data System (ADS)

Mattsson, Thomas R.; Jones, Reese; Ward, Donald; Spataru, Catalin; Shulenburger, Luke; Benedict, Lorin X.

2015-06-01

Window materials are ubiquitous in shock physics and with high energy density drivers capable of reaching multi-Mbar pressures the use of LiF is increasing. Velocimetry and temperature measurements of a sample through a window are both influenced by the assumed index of refraction and thermal conductivity, respectively. We report on calculations of index of refraction using the many-body theory GW and thermal ionic conductivity using linear response theory and model potentials. The results are expected to increase the accuracy of a broad range of high-pressure shock- and ramp compression experiments. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

Basin deconstruction-construction: Seeking thermal-tectonic consistency through the integration of geochemical thermal indicators and seismic fault mechanical stratigraphy ​- Example from Faras Field, North Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Pigott, John D.; Abouelresh, Mohamed O.

2016-02-01

To construct a model of a sedimentary basin's thermal tectonic history is first to deconstruct it: taking apart its geological elements, searching for its initial conditions, and then to reassemble the elements in the temporal order that the basin is assumed to have evolved. Two inherent difficulties implicit to the analysis are that most organic thermal indicators are cumulative, irreversible and a function of both temperature and time and the non-uniqueness of crustal strain histories which complicates tectonic interpretations. If the initial conditions (e.g. starting maturity of the reactants and initial crustal temperature) can be specified and the boundary conditions incrementally designated from changes in the lithospheric heat engine owing to stratigraphic structural constraints, then the number of pathways for the temporal evolution of a basin is greatly reduced. For this investigation, model input uncertainties are reduced through seeking a solution that iteratively integrates the geologically constrained tectonic subsidence, geochemically constrained thermal indicators, and geophysically constrained fault mechanical stratigraphy. The Faras oilfield in the Abu Gharadig Basin, North Western Desert, Egypt, provides an investigative example of such a basin's deconstructive procedure. Multiple episodes of crustal extension and shortening are apparent in the tectonic subsidence analyses which are constrained from the fault mechanical stratigraphy interpreted from reflection seismic profiles. The model was iterated with different thermal boundary conditions until outputs best fit the geochemical observations. In so doing, the thermal iterations demonstrate that general relationship that basin heat flow increases decrease vertical model maturity gradients, increases in surface temperatures shift vertical maturity gradients linearly to higher values, increases in sediment conductivities lower vertical maturities with depth, and the addition of ;ghost; layers (those layers removed) prior to the erosional event increase maturities beneath, and conversely. These integrated constraints upon the basin evolution model indicate that the principal source rocks, Khatatba and the lowest part of the Alam El Bueib formations, entered the oil window at approximately 95 Ma and the gas window at approximately 25 Ma. The upper part of the Alam El Bueib Formation is within the oil window at the present day. Establishing initial and boundary value conditions for a basin's thermal evolution when geovalidated by the integration of seismic fault mechanical stratigraphy, tectonic subsidence analysis, and organic geochemical maturity indicators provides a powerful tool for optimizing petroleum exploration in both mature and frontier basins.

Performance of the round window soft coupler for the backward stimulation of the cochlea in a temporal bone model.

PubMed

Gostian, Antoniu-Oreste; Schwarz, David; Mandt, Philipp; Anagiotos, Andreas; Ortmann, Magdalene; Pazen, David; Beutner, Dirk; Hüttenbrink, Karl-Bernd

2016-11-01

The round window vibroplasty is a feasible option for the treatment of conductive, sensorineural and mixed hearing loss. Although clinical data suggest a satisfying clinical outcome with various coupling methods, the most efficient coupling technique of the floating mass transducer to the round window is still a matter of debate. For this, a soft silicone-made coupler has been developed recently that aims to ease and optimize the stimulation of the round window membrane of this middle ear implant. We performed a temporal bone study evaluating the performance of the soft coupler compared to the coupling with individually shaped cartilage, perichondrium and the titanium round window coupler with loads up to 20 mN at the unaltered and fully exposed round window niche. The stimulation of the cochlea was measured by the volume velocities of the stapes footplate detected by a laser Doppler vibrometer. The coupling method was computed as significant factor with cartilage and perichondrium allowing for the highest volume velocities followed by the soft and titanium coupler. Exposure of the round window niche allowed for higher volume velocities while the applied load did not significantly affect the results. The soft coupler allows for a good contact to the round window membrane and an effective backward stimulation of the cochlea. Clinical data are mandatory to evaluate performance of this novel coupling method in vivo.

Improving the Performance of PbS Quantum Dot Solar Cells by Optimizing ZnO Window Layer

NASA Astrophysics Data System (ADS)

Yang, Xiaokun; Hu, Long; Deng, Hui; Qiao, Keke; Hu, Chao; Liu, Zhiyong; Yuan, Shengjie; Khan, Jahangeer; Li, Dengbing; Tang, Jiang; Song, Haisheng; Cheng, Chun

2017-04-01

Comparing with hot researches in absorber layer, window layer has attracted less attention in PbS quantum dot solar cells (QD SCs). Actually, the window layer plays a key role in exciton separation, charge drifting, and so on. Herein, ZnO window layer was systematically investigated for its roles in QD SCs performance. The physical mechanism of improved performance was also explored. It was found that the optimized ZnO films with appropriate thickness and doping concentration can balance the optical and electrical properties, and its energy band align well with the absorber layer for efficient charge extraction. Further characterizations demonstrated that the window layer optimization can help to reduce the surface defects, improve the heterojunction quality, as well as extend the depletion width. Compared with the control devices, the optimized devices have obtained an efficiency of 6.7% with an enhanced V oc of 18%, J sc of 21%, FF of 10%, and power conversion efficiency of 58%. The present work suggests a useful strategy to improve the device performance by optimizing the window layer besides the absorber layer.

Frugal Construction Standards. Final [Report].

ERIC Educational Resources Information Center

SMART Schools Clearinghouse, Tallahassee, FL.

This booklet provides best practice recommendations for building functional and frugal schools in Florida. Seventeen best practice construction recommendations are addressed, including recommendations for sitework, concrete, masonry, metals, wood and plastics, thermal and moisture protection, doors and windows, finishes, equipment, furnishings,…

Extreme Cold: A Prevention Guide to Promote Your Personal Health and Safety

MedlinePlus

... possible, weatherproof your home by adding weather- stripping, insulation, insulated doors and storm windows, or thermal-pane ... colored cloth for added traction) 4 Indoor Safety Heat Your Home Safely If you plan to use ...

Measurement of stapes vibration in Human temporal bones by round window stimulation using a 3-coil transducer.

PubMed

Shin, Dong Ho; Kim, Dong Wook; Lim, Hyung Gyu; Jung, Eui Sung; Seong, Ki Woong; Lee, Jyung Hyun; Kim, Myoung Nam; Cho, Jin Ho

2014-01-01

Round window placement of a 3-coil transducer offers a new approach for coupling an implantable hearing aid to the inner ear. The transducer exhibits high performance at low-frequencies. One remarkable feature of the 3-coil transducer is that it minimizes leakage flux. Thus, the transducer, which consists of two permanent magnets and three coils, can enhance vibrational displacement. In human temporal bones, stapes vibration was observed by laser Doppler vibrometer in response to round window stimulation using the 3-coil transducer. Coupling between the 3-coil transducer and the round window was connected by a wire-rod. The stimulation created stapes velocity when the round window stimulated. Performance evaluation was conducted by measuring stapes velocity. To verify the performance of the 3-coil transducer, stapes velocity for round window and tympanic membrane stimulation were compared, respectively. Stapes velocity by round window stimulation using the 3-coil transducer was approximately 14 dB higher than that achieved by tympanic membrane stimulation. The study shows that 3-coil transducer is suitable for implantable hearing aids.

Effects of ventilation behaviour on indoor heat load based on test reference years.

PubMed

Rosenfelder, Madeleine; Koppe, Christina; Pfafferott, Jens; Matzarakis, Andreas

2016-02-01

Since 2003, most European countries established heat health warning systems to alert the population to heat load. Heat health warning systems are based on predicted meteorological conditions outdoors. But the majority of the European population spends a substantial amount of time indoors, and indoor thermal conditions can differ substantially from outdoor conditions. The German Meteorological Service (Deutscher Wetterdienst, DWD) extended the existing heat health warning system (HHWS) with a thermal building simulation model to consider heat load indoors. In this study, the thermal building simulation model is used to simulate a standardized building representing a modern nursing home, because elderly and sick people are most sensitive to heat stress. Different types of natural ventilation were simulated. Based on current and future test reference years, changes in the future heat load indoors were analyzed. Results show differences between the various ventilation options and the possibility to minimize the thermal heat stress during summer by using an appropriate ventilation method. Nighttime ventilation for indoor thermal comfort is most important. A fully opened window at nighttime and the 2-h ventilation in the morning and evening are more sufficient to avoid heat stress than a tilted window at nighttime and the 1-h ventilation in the morning and the evening. Especially the ventilation in the morning seems to be effective to keep the heat load indoors low. Comparing the results for the current and the future test reference years, an increase of heat stress on all ventilation types can be recognized.

Thermal biology of the sub-polar-temperate estuarine crab Hemigrapsus crenulatus (Crustacea: Decapoda: Varunidae).

PubMed

Cumillaf, Juan P; Blanc, Johnny; Paschke, Kurt; Gebauer, Paulina; Díaz, Fernando; Re, Denisse; Chimal, María E; Vásquez, Jorge; Rosas, Carlos

2016-02-15

Optimum temperatures can be measured through aerobic scope, preferred temperatures or growth. A complete thermal window, including optimum, transition (Pejus) and critical temperatures (CT), can be described if preferred temperatures and CT are defined. The crustacean Hemigrapsus crenulatus was used as a model species to evaluate the effect of acclimation temperature on: (i) thermal preference and width of thermal window, (ii) respiratory metabolism, and (iii) haemolymph proteins. Dependant on acclimation temperature, preferred temperature was between 11.8°C and 25.2°C while CT was found between a minimum of 2.7°C (CTmin) and a maximum of 35.9°C (CTmax). These data and data from tropical and temperate crustaceans were compared to examine the association between environmental temperature and thermal tolerance. Temperate species have a CTmax limit around 35°C that corresponded with the low CTmax limit of tropical species (34-36°C). Tropical species showed a CTmin limit around 9°C similar to the maximum CTmin of temperate species (5-6°C). The maximum CTmin of deep sea species that occur in cold environments (2.5°C) matched the low CTmin values (3.2°C) of temperate species. Results also indicate that the energy required to activate the enzyme complex (Ei) involved in respiratory metabolism of ectotherms changes along the latitudinal gradient of temperature. © 2016. Published by The Company of Biologists Ltd.

Effects of ventilation behaviour on indoor heat load based on test reference years

NASA Astrophysics Data System (ADS)

Rosenfelder, Madeleine; Koppe, Christina; Pfafferott, Jens; Matzarakis, Andreas

2016-02-01

Since 2003, most European countries established heat health warning systems to alert the population to heat load. Heat health warning systems are based on predicted meteorological conditions outdoors. But the majority of the European population spends a substantial amount of time indoors, and indoor thermal conditions can differ substantially from outdoor conditions. The German Meteorological Service (Deutscher Wetterdienst, DWD) extended the existing heat health warning system (HHWS) with a thermal building simulation model to consider heat load indoors. In this study, the thermal building simulation model is used to simulate a standardized building representing a modern nursing home, because elderly and sick people are most sensitive to heat stress. Different types of natural ventilation were simulated. Based on current and future test reference years, changes in the future heat load indoors were analyzed. Results show differences between the various ventilation options and the possibility to minimize the thermal heat stress during summer by using an appropriate ventilation method. Nighttime ventilation for indoor thermal comfort is most important. A fully opened window at nighttime and the 2-h ventilation in the morning and evening are more sufficient to avoid heat stress than a tilted window at nighttime and the 1-h ventilation in the morning and the evening. Especially the ventilation in the morning seems to be effective to keep the heat load indoors low. Comparing the results for the current and the future test reference years, an increase of heat stress on all ventilation types can be recognized.

Second LDEF Post-Retrieval Symposium interim results of experiment A0034

NASA Technical Reports Server (NTRS)

Linton, Roger C.; Kamenetzky, Rachel R.

1993-01-01

Thermal control coatings and contaminant collector mirrors were exposed on the leading and trailing edge modules of Long Duration Exposure Facility (LDEF) experiment A0034 to provide a basis of comparison for investigating the role of atomic oxygen in the stimulation of volatile outgassing products. The exposure of identical thermal coatings on both the leading and trailing edges of the LDEF and the additional modified exposure of identical coatings under glass windows and metallic covers in each of the flight modules provided multiple combinations of space environmental exposure to the coatings and the contaminant collector mirrors. Investigations were made to evaluate the effects of the natural space and the induced environments on the thermal coatings and the collector mirrors to differentiate the sources of observed material degradation. Two identical flight units were fabricated for the LDEF mission, each of which included twenty-five thermal control coatings mounted in isolated compartments, each with an adjacent contaminant collector mirror mounted on the wall. The covers of the flight units included apertures for each compartment, exposing the thermal coatings directly to the space environment. Six of these compartments were sealed with ultraviolet-grade transmitting quartz windows and four other compartments were sealed with aluminum covers. One module of this passive LDEF experiment, occupying one-sixth of a full tray, was mounted in Tray C9 (leading edge), while the other identical module was mounted in Tray C3 (trailing edge).

Enabling two-phase microfluidic thermal transport systems using a novel thermal-flux degassing and fluid charging approach

NASA Astrophysics Data System (ADS)

Singh Dhillon, Navdeep; Pisano, Albert P.

2014-03-01

A novel two-port thermal-flux method has been proposed and demonstrated for degassing and charging two-phase microfluidic thermal transport systems with a degassed working fluid. In microscale heat pipes and loop heat pipes (mLHPs), small device volumes and large capillary forces associated with smaller feature sizes render conventional vacuum pump-based degassing methods quite impractical. Instead, we employ a thermally generated pressure differential to purge non-condensable gases from these devices before charging them with a degassed working fluid in a two-step process. Based on the results of preliminary experiments studying the effectiveness and reliability of three different high temperature-compatible device packaging approaches, an optimized compression packaging technique was developed to degas and charge a mLHP device using the thermal-flux method. An induction heating-based noninvasive hermetic sealing approach for permanently sealing the degassed and charged mLHP devices has also been proposed. To demonstrate the efficacy of this approach, induction heating experiments were performed to noninvasively seal 1 mm square silicon fill-hole samples with donut-shaped solder preforms. The results show that the minimum hole sealing induction heating time is heat flux limited and can be estimated using a lumped capacitance thermal model. However, further continued heating of the solder uncovers the hole due to surface tension-induced contact line dynamics of the molten solder. It was found that an optimum mass of the solder preform is required to ensure a wide enough induction-heating time window for successful sealing of a fill-hole.

WinSCP for Windows File Transfers | High-Performance Computing | NREL

Science.gov Websites

WinSCP for Windows File Transfers WinSCP for Windows File Transfers WinSCP for can used to securely transfer files between your local computer running Microsoft Windows and a remote computer running Linux

Fluorinated phosphazene co-solvents for improved thermal and safety performance in lithium-ion battery electrolytes

NASA Astrophysics Data System (ADS)

Rollins, Harry W.; Harrup, Mason K.; Dufek, Eric J.; Jamison, David K.; Sazhin, Sergiy V.; Gering, Kevin L.; Daubaras, Dayna L.

2014-10-01

The safety of lithium-ion batteries is coming under increased scrutiny as they are being adopted for large format applications especially in the vehicle transportation industry and for grid-scale energy storage. The primary short-comings of lithium-ion batteries are the flammability of the liquid electrolyte and sensitivity to high voltage and elevated temperatures. We have synthesized a series of non-flammable fluorinated phosphazene liquids and blended them with conventional carbonate solvents. While the use of these phosphazenes as standalone electrolytes is highly desirable, they simply do not satisfy all of the many requirements that must be met such as high LiPF6 solubility and low viscosity, thus we have used them as additives and co-solvents in blends with typical carbonates. The physical and electrochemical properties of the electrolyte blends were characterized, and then the blends were used to build 2032-type coin cells. We have evaluated the performance of the electrolytes by determining the physical properties, thermal stability, electrochemical window, cell cycling data, and the ability to form solid electrolyte interphase (SEI) films. This paper presents our most recent results on a new series of fluorinated cyclic phosphazene trimers, the FM series, which has exhibited numerous beneficial effects on battery performance, lifetimes, and safety aspects.

Nondestrucive analysis of fuel pins

DOEpatents

Stepan, I.E.; Allard, N.P.; Suter, C.R.

1972-11-03

Disclosure is made of a method and a correspondingly adapted facility for the nondestructive analysis of the concentation of fuel and poison in a nuclear reactor fuel pin. The concentrations of fuel and poison in successive sections along the entire length of the fuel pin are determined by measuring the reactivity of a thermal reactor as each successive small section of the fuel pin is exposed to the neutron flux of the reactor core and comparing the measured reactivity with the reactivities measured for standard fuel pins having various known concentrations. Only a small section of the length of the fuel pin is exposed to the neutron flux at any one time while the remainder of the fuel pin is shielded from the neutron flux. In order to expose only a small section at any one time, a boron-10-lined dry traverse tube is passed through the test region within the core of a low-power thermal nuclear reactor which has a very high fuel sensitivity. A narrow window in the boron-10 lining is positioned at the core center line. The fuel pins are then systematically traversed through the tube past the narrow window such that successive small sections along the length of the fuel pin are exposed to the neutron flux which passes through the narrow window.

Night ventilation at courtyard housing estate in warm humid tropic for sustainable environment

NASA Astrophysics Data System (ADS)

Defiana, Ima; Teddy Badai Samodra, FX; Setyawan, Wahyu

2018-03-01

The problem in the night-time for warm humid tropic housing estate is thermal discomfort. Heat gains accumulation from building envelope, internal heat gains and activities of occupants influence indoor thermal comfort. Ventilation is needed for transfer or removes heat gains accumulation to outdoor. This study describes the role of an inner courtyard to promote pressure difference. Pressure difference as a wind driven force to promote wind velocity thereby could transfer indoor heat gains accumulation to outdoor of building. A simulation used as the research method for prediction wind velocity. Purposive sampling used as the method to choose building sample with similar inner courtyards. The field survey was conducted to obtain data of inner courtyard typologies and two housing were used as model simulation. Furthermore, the simulation is running in steady state mode, at 05.00 pm when the occupants usually close window. But the window should be opened in the night-time to transfer indoor heat gain to outdoor. The result shows that the factor influencing physiological cooling as consequences of inner courtyard are height to width ratio, the distance between inner courtyard to windward, window configuration and the inner courtyard design-the proportion between the length, the width, and the height.

Optimum temperature in juvenile salmonids: connecting subcellular indicators to tissue function and whole-organism thermal optimum.

PubMed

Anttila, Katja; Casselman, Matthew T; Schulte, Patricia M; Farrell, Anthony P

2013-01-01

Temperature affects processes at all levels of biological organization, but it is unclear whether processes at different levels have similar thermal optima (T(opt)). Here, we compare the T(opt) for aerobic scope, a whole-organism measure of performance, with both the Arrhenius breakpoint temperature for maximum heart rate (HR-ABT), a measure of tissue level performance, and the temperature at which AMP-activated protein kinase (AMPK) is phosphorylated in the heart, an indicator of an increase in dependence on anaerobic energy metabolism at the cellular level in juvenile rainbow trout Oncorhynchus mykiss. The T(opt) for aerobic scope was 19°C, with aerobic scope being maintained at ≥90% of maximum (termed a "T(opt) window") from 16.5° to 20.5°C. HR-ABT occurred at [Formula: see text], while the profile of AMPK phosphorylation started to change from baseline at 19°C, suggesting that these processes have similar thermal sensitivities as a fish is warmed to T(opt). The effects of temperature on AMPK phosphorylation were also measured in coho salmon Oncorhynchus kisutch hearts and compared with previously published values for HR-ABT and aerobic scope T(opt). AMPK phosphorylation in coho hearts began to change at temperatures above 17°C, which again is comparable with the published T(opt) for aerobic scope (17°C) and HR-ABT ([Formula: see text]) in these individuals. Thus, the thermal sensitivity of these subcellular, tissue, and whole-organism functions are highly correlated in both rainbow trout and coho salmon and may depend on each other.

Piezocomposite Actuator Arrays for Correcting and Controlling Wavefront Error in Reflectors

NASA Technical Reports Server (NTRS)

Bradford, Samuel Case; Peterson, Lee D.; Ohara, Catherine M.; Shi, Fang; Agnes, Greg S.; Hoffman, Samuel M.; Wilkie, William Keats

2012-01-01

Three reflectors have been developed and tested to assess the performance of a distributed network of piezocomposite actuators for correcting thermal deformations and total wave-front error. The primary testbed article is an active composite reflector, composed of a spherically curved panel with a graphite face sheet and aluminum honeycomb core composite, and then augmented with a network of 90 distributed piezoelectric composite actuators. The piezoelectric actuator system may be used for correcting as-built residual shape errors, and for controlling low-order, thermally-induced quasi-static distortions of the panel. In this study, thermally-induced surface deformations of 1 to 5 microns were deliberately introduced onto the reflector, then measured using a speckle holography interferometer system. The reflector surface figure was subsequently corrected to a tolerance of 50 nm using the actuators embedded in the reflector's back face sheet. Two additional test articles were constructed: a borosilicate at window at 150 mm diameter with 18 actuators bonded to the back surface; and a direct metal laser sintered reflector with spherical curvature, 230 mm diameter, and 12 actuators bonded to the back surface. In the case of the glass reflector, absolute measurements were performed with an interferometer and the absolute surface was corrected. These test articles were evaluated to determine their absolute surface control capabilities, as well as to assess a multiphysics modeling effort developed under this program for the prediction of active reflector response. This paper will describe the design, construction, and testing of active reflector systems under thermal loads, and subsequent correction of surface shape via distributed peizeoelctric actuation.

Measure Guideline. Wood Window Repair, Rehabilitation, and Replacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, P.; Eng, P.

2012-12-01

This measure guideline provides information and guidance on rehabilitating, retrofitting, and replacing existing window assemblies in residential construction. The intent is to provide information regarding means and methods to improve the energy and comfort performance of existing wood window assemblies in a way that takes into consideration component durability, in-service operation, and long term performance of the strategies.

Measure Guideline: Window Repair, Rehabilitation, and Replacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, P.

2012-12-01

This measure guideline provides information and guidance on rehabilitating, retrofitting, and replacing existing window assemblies in residential construction. The intent is to provide information regarding means and methods to improve the energy and comfort performance of existing wood window assemblies in a way that takes into consideration component durability, in-service operation, and long term performance of the strategies.

Infrared sensor and window system issues

NASA Astrophysics Data System (ADS)

Hargraves, Charles H., Jr.; Martin, James M.

1992-12-01

EO/IR windows are a significant challenge for the weapon system sensor designer who must design for high EO performance, low radar cross section (RCS), supersonic flight, durability, producibility and affordable initial and life cycle costs. This is particularly true in the 8 to 12 micron IR band at which window materials and coating choices are limited by system design requirements. The requirements also drive the optimization of numerous mechanical, optical, materials, and electrical parameters. This paper addresses the EO/IR window as a system design challenge. The interrelationship of the optical, mechanical, and system design processes are examined. This paper presents a summary of the test results, trade studies and analyses that were performed for multi-segment, flight-worthy optical windows with superior optical performance at subsonic and supersonic aircraft velocities and reduced radar cross section. The impact of the window assembly on EO system modulation transfer function (MTF) and sensitivity will be discussed. The use of conductive coatings for shielding/signature control will be discussed.

Assessment of unconventional oil and gas resources in the Jurassic Sargelu Formation of Iraq, 2014

USGS Publications Warehouse

Schenk, Christopher J.; Pitman, Janet K.; Charpentier, Ronald R.; Klett, Timothy R.; Gaswirth, Stephanie B.; Brownfield, Michael E.; Leathers, Heidi M.; Mercier, Tracey J.; Tennyson, Marilyn E.

2015-01-01

The USGS assessment methodology consists of a well-performance approach that recognizes the geologic variability within assessed reservoirs. For non-U.S. assessments, the USGS assesses shale-gas or shale-oil reservoirs that (1) contain greater than 2 weight percent total organic carbon (TOC), (2) are within the proper thermal maturity window for oil or gas generation, (3) have greater than 15-m thickness of organic-rich shale, and (4) contain Type I or II organic matter. These specific USGS criteria when applied to any given shale-oil or shale-gas reservoir might significantly reduce the potential resource assessment area compared to maps made with greater than 1 weight percent TOC.

Two-Band, Low-Loss Microwave Window

NASA Technical Reports Server (NTRS)

Britcliffe, Michael; Franco, Manuel

2007-01-01

A window for a high-sensitivity microwave receiving system allows microwave radiation to pass through to a cryogenically cooled microwave feed system in a vacuum chamber, while keeping ambient air out of the chamber and helping to keep the interior of the chamber cold. The microwave feed system comprises a feed horn and a low-noise amplifier, both of which are required to be cooled to a temperature of 15 K during operation. The window is designed to exhibit very little microwave attenuation in two frequency bands: 8 to 9 GHz and 30 to 40 GHz. The window is 15 cm in diameter. It includes three layers (see figure): 1) The outer layer is made of a poly(tetrafluoroethylene) film 0.025 mm thick. This layer serves primarily to reflect and absorb solar ultraviolet radiation to prolong the life of the underlying main window layer, which is made of a polyimide that becomes weakened when exposed to ultraviolet. The poly(tetrafluoroethylene) layer also protects the main window layer against abrasion. Moreover, the inherent hydrophobicity of poly(tetrafluoroethylene) helps to prevent the highly undesirable accumulation of water on the outer surface. 2) The polyimide main window layer is 0.08 mm thick. This layer provides the vacuum seal for the window. 3) A 20-mm-thick layer of ethylene/ propylene copolymer foam underlies the main polyimide window layer. This foam layer acts partly as a thermal insulator: it limits radiational heating of the microwave feed horn and, concomitantly, limits radiational cooling of the window. This layer has high compressive strength and provides some mechanical support for the main window layer, reducing the strength required of the main window layer. The ethylene/propylene copolymer foam layer is attached to an aluminum window ring by means of epoxy. The outer poly(tetrafluoroethylene) film and the main polyimide window layer are sandwiched together and pressed against the window ring by use of a bolted clamp ring. The window has been found to introduce a microwave loss of only about 0.4 percent. The contribution of the window to the noise temperature of the microwave feed system has been found to be less than 1 K at 32 GHz and 0.2 K at 8.4 GHz.

Window-mounted auxiliary solar heater

NASA Technical Reports Server (NTRS)

Anthony, K. G.; Herndon, E. P.

1977-01-01

System uses hot-air collectors, no thermal storage, and fan with thermostat switches. At cost of heating efficiency, unit could be manufactured and sold at price allowing immediate entry to market as auxiliary heating system. Its simplicity allows homeowner installation, and maintenance is minimal.

Thermal biology of prey (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya from the Yucatan Peninsula.

PubMed

Noyola Regil, Javier; Mascaro, Maite; Díaz, Fernando; Denisse Re, Ana; Sánchez-Zamora, Adolfo; Caamal-Monsreal, Claudia; Rosas, Carlos

2015-10-01

On the Yucatan Peninsula there is an upwelling which allows access to a body of cold water that controls temperature in this area. This modulates the ecology and distribution of organisms that inhabit the continental shelf. The objective of this study was to determine the effect of different acclimation temperatures on the thermal biology of prey as mollusc, crustacean (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators as fish (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya. Octopus prey preferred temperatures between 23.5°C and 26.0°C, while predators preferred temperatures 26.4-28.5°C. The species with largest thermal windows were M. corona bispinosa (328.8°C(2)), C. similis (322.8°C(2)), L. dubia (319.2°C(2)), C. undecimalis (288.6°C(2)), O. chrysurus (237.5°C(2)), while the smallest thermal window was for S. pugilis (202.0°C(2)). The acclimation response ratios (ARR) estimated for prey ranged from 0.24-0.55 in animals exposed to CTMax and 0.21-0.65 in those exposed to CTMin. Amongst predators, ARR ranged from 0.30 to 0.60 and 0.41 to 0.53 for animals exposed to CTMax and CTMin, respectively. Correlating the optimal temperature limits of prey and predators with surface temperatures on the continental shelf and those 4m deep showed that the main prey, Callinectes similis and L. dubia, shared a thermal niche and that an increase in temperature could force these species to migrate to other sites to find optimal temperatures for their physiological functions. As a consequence the continental shelf community would undergo a structural change. Predators were found to be near their optimal temperatures in surface temperatures on the continental shelf. We conclude that they would remain in the area in a warming scenario. The size of the thermal window was related to the type of ecosystem inhabited by these species. These ARR intervals allowed us to categorize the species as temperate or tropical, according to the oceanographic conditions that prevail on the Yucatan Peninsula. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ground-based remote sensing of thin clouds in the Arctic

NASA Astrophysics Data System (ADS)

Garrett, T. J.; Zhao, C.

2012-11-01

This paper describes a method for using interferometer measurements of downwelling thermal radiation to retrieve the properties of single-layer clouds. Cloud phase is determined from ratios of thermal emission in three "micro-windows" where absorption by water vapor is particularly small. Cloud microphysical and optical properties are retrieved from thermal emission in two micro-windows, constrained by the transmission through clouds of stratospheric ozone emission. Assuming a cloud does not approximate a blackbody, the estimated 95% confidence retrieval errors in effective radius, visible optical depth, number concentration, and water path are, respectively, 10%, 20%, 38% (55% for ice crystals), and 16%. Applied to data from the Atmospheric Radiation Measurement program (ARM) North Slope of Alaska - Adjacent Arctic Ocean (NSA-AAO) site near Barrow, Alaska, retrievals show general agreement with ground-based microwave radiometer measurements of liquid water path. Compared to other retrieval methods, advantages of this technique include its ability to characterize thin clouds year round, that water vapor is not a primary source of retrieval error, and that the retrievals of microphysical properties are only weakly sensitive to retrieved cloud phase. The primary limitation is the inapplicability to thicker clouds that radiate as blackbodies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Three side-by-side lab houses were built, instrumented and monitored in an effort to determine through field testing and analysis the relative contributions of select technologies toward reducing energy use in new manufactured homes.The lab houses in Russellville, Alabama compared the performance of three homes built to varying levels of thermal integrity and HVAC equipment: a baseline HUD-code home equipped with an electric furnace and a split system air conditioner; an ENERGY STAR manufactured home with an enhanced thermal envelope and traditional split system heat pump; and a house designed to qualify for Zero Energy Ready Home designation with a ductlessmore » mini-split heat pump with transfer fan distribution system in place of the traditional duct system for distribution. Experiments were conducted in the lab houses to evaluate impact on energy and comfort of interior door position, window blind position and transfer fan operation. The report describes results of tracer gas and co-heating tests and presents calculation of the heat pump coefficient of performance for both the traditional heat pump and the ductless mini-split. A series of calibrated energy models was developed based on measured data and run in three locations in the Southeast to compare annual energy usage of the three homes.« less

Pulse thermography for quantitative nondestructive evaluation of sound, de-mineralized and re-mineralized enamel

NASA Astrophysics Data System (ADS)

Ando, Masatoshi; Sharp, Nathan; Adams, Douglas

2012-04-01

Current limitations for diagnosing mineralization state of tooth enamel can lead to improper surgical treatments. A method is investigated by which the tooth health state is characterized according to its thermal response, which is hypothesized to be sensitive to increased porosity in enamel that is caused by demineralization. Several specimens consisting of previously extracted human teeth a re prepared by exposure to Streptococcus mutans A32-2 in trypticase-soy-borth supplemented with 5% sucrose at 37°C for 3 or 6 days to de-mineralize two 1×1mm2-windows on each tooth. One of these windows is then re-mineralized with 250 or 1,100ppm-F as NaF for 10 days by pH-cyclic-model. Pulse thermography is used to measure the thermal response of these sections as well as the sound (healthy) portions of the specimen. A spatial profile of the thermal parameters of the specimens is then extracted from the thermography data and are used to compare the sound, de-mineralized, and re-mineralized areas. Results show that the thermal parameters are sensitive to the mineralization state of the tooth and that this method has the potential to accurately and quickly characterize the mineralization state of teeth, thereby allowing future dentists to make informed decisions regarding the best treatment for teeth that have experienced demineralization.

Highly Flexible, Multipixelated Thermosensitive Smart Windows Made of Tough Hydrogels.

PubMed

La, Thanh-Giang; Li, Xinda; Kumar, Amit; Fu, Yiyang; Yang, Shu; Chung, Hyun-Joong

2017-09-27

In a cold night, a clear window that will become opaque while retaining the indoor heat is highly desirable for both privacy and energy efficiency. A thermally responsive material that controls both the transmittance of solar radiance (predominantly in the visible and near-infrared wavelengths) and blackbody radiation (mainly in the mid-infrared) can realize such windows with minimal energy consumption. Here, we report a smart coating made from polyampholyte hydrogel (PAH) that transforms from a transparency state to opacity to visible radiation and strengthens opacity to mid-infrared when lowering the temperature as a result of phase separation between the water-rich and polymer-rich phases. To match a typical temperature fluctuation during the day, we fine-tune the phase transition temperature between 25 and 55 °C by introducing a small amount of relatively hydrophobic monomers (0.1 to 0.5 wt % to PAH). To further demonstrate an actively controlled, highly flexible, and high-contrast smart window, we build in an array of electric heaters made of printed elastomeric composite. The multipixelated window offers rapid switching, ∼70 s per cycle, whereas the device can withstand high strain (up to 80%) during operations.

Interior and Exterior Low-E Storm Window Installation

ScienceCinema

Witters, Sarah

2018-01-16

Until recently, energy-efficient window retrofit options have largely been limited to repair or replacement; leaving the homeowner to decide between affordability and deeper energy savings. A new and improved low-e storm window boasts a combination of curb appeal and energy efficiency, all for a fraction of the cost of window replacement. A recent whole-home experiment performed by PNNL suggests that attaching low-e storm windows can result in as much energy savings replacing the windows.

Low-E Storm Windows Gain Acceptance as a Home Weatherization Measure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilbride, Theresa L.; Cort, Katherine A.

This article for Home Energy Magazine describes work by the U.S. Department of Energy to develop low-emissivity storm windows as an energy efficiency-retrofit option for existing homes. The article describes the low-emissivity invisible silver metal coatings on the glass, which reflect heat back into the home in winter or back outside in summer and the benefits of low-e storm windows including insulation, air sealing, noise blocking, protection of antique windows, etc. The article also describes Pacific Northwest National Laboratory's efforts on behalf of DOE to overcome market barriers to adoption of the technology, including performance validation studies in the PNNLmore » Lab Homes, cost effectiveness analysis, production of reports, brochures, how-to guides on low-e storm window installation for the Building America Solution Center, and a video posted on YouTube. PNNL's efforts were reviewed by the Pacific Northwest Regional Technical Forum (RTF), which serves as the advisory board to the Pacific Northwest Electric Power Planning Council and Bonneville Power Administration. In late July 2015, the RTF approved the low-e storm window measure’s savings and specifications, a critical step in integrating low-e storm windows into energy-efficiency planning and utility weatherization and incentive programs. PNNL estimates that more than 90 million homes in the United States with single-pane or low-performing double-pane windows would benefit from the technology. Low-e storm windows are suitable not only for private residences but also for small commercial buildings, historic properties, and facilities that house residents, such as nursing homes, dormitories, and in-patient facilities. To further assist in the market transformation of low-e storm windows and other high-efficiency window attachments, DOE helped found the window Attachment Energy Rating Council (AERC) in 2015. AERC is an independent, public interest, non-profit organization whose mission is to rate, label, and certify the performance of window attachments.« less

Robust Satellite Techniques to support the short-term assessment of the seismic hazard in Japan: an analysis on 11 years (2005-2015) of MTSAT TIR observations

NASA Astrophysics Data System (ADS)

Genzano, Nicola; Filizzola, Carolina; Hattori, Katsumi; Lisi, Mariano; Paciello, Rossana; Pergola, Nicola; Tramutoli, Valerio

2017-04-01

In order to increase reliability and precision of short-term seismic hazard assessment (but also a possible earthquakes forecast), the integration of different kinds of observations (chemical, physical, biological, etc.) in a multi-parametric approach could be a useful strategy to be undertaken. Among the different observational methodologies, the fluctuations of Earth's thermally emitted radiation, measured by satellite sensors operating in the thermal infrared (TIR) spectral range, have been proposed since eighties as a potential earthquake precursor. Since 2001, the general change detention approach Robust Satellite Techniques (RST), used in combination with RETIRA (Robust Estimator of TIR Anomalies) index, showed good ability to discriminate anomalous TIR signals possibly associated to seismic activity, from the normal variability of TIR signal due to other causes (e.g. meteorological). In this paper, the RST data analysis approach has been implemented on TIR satellite records collected over Japan by the geostationary satellite sensor MTSAT (Multifunctional Transport SATellites) in the period June 2005 - December 2015 in order to evaluate its possible contribute to an improved multi parametric system for a time-Dependent Assessment of Seismic Hazard (t-DASH). For the first time, thermal anomalies have been identified comparing the daily TIR radiation of each location of the considered satellite portions, with its historical expected value and variation range (i.e. RST reference fields) computed using a a 30 days moving window (i.e. 15 days before and 15 days after the considered day of the year) instead than fixed monthly window. Preliminary results of correlation analysis among the appearance of Significant Sequences of TIR Anomalies (SSTAs) and time, location and magnitude of earthquakes (M≥5), performed by applying predefined space-temporal and magnitude constraints, show that 80% of SSTAs were in an apparent space-time relations with earthquakes with a false alarm rate of 20%.

Color tunable low cost transparent heat reflector using copper and titanium oxide for energy saving application

PubMed Central

Dalapati, Goutam Kumar; Masudy-Panah, Saeid; Chua, Sing Teng; Sharma, Mohit; Wong, Ten It; Tan, Hui Ru; Chi, Dongzhi

2016-01-01

Multilayer coating structure comprising a copper (Cu) layer sandwiched between titanium dioxide (TiO2) were demonstrated as a transparent heat reflecting (THR) coating on glass for energy-saving window application. The main highlight is the utilization of Cu, a low-cost material, in-lieu of silver which is widely used in current commercial heat reflecting coating on glass. Color tunable transparent heat reflecting coating was realized through the design of multilayer structure and process optimization. The impact of thermal treatment on the overall performance of sputter deposited TiO2/Cu/TiO2 multilayer thin film on glass substrate is investigated in detail. Significant enhancement of transmittance in the visible range and reflectance in the infra-red (IR) region has been observed after thermal treatment of TiO2/Cu/TiO2 multilayer thin film at 500 °C due to the improvement of crystal quality of TiO2. Highest visible transmittance of 90% and IR reflectance of 85% at a wavelength of 1200 nm are demonstrated for the TiO2/Cu/TiO2 multilayer thin film after annealing at 500 °C. Performance of TiO2/Cu/TiO2 heat reflector coating decreases after thermal treatment at 600 °C. The wear performance of the TiO2/Cu/TiO2 multilayer structure has been evaluated through scratch hardness test. The present work shows promising characteristics of Cu-based THR coating for energy-saving building industry. PMID:26846687

Color tunable low cost transparent heat reflector using copper and titanium oxide for energy saving application.

PubMed

Dalapati, Goutam Kumar; Masudy-Panah, Saeid; Chua, Sing Teng; Sharma, Mohit; Wong, Ten It; Tan, Hui Ru; Chi, Dongzhi

2016-02-05

Multilayer coating structure comprising a copper (Cu) layer sandwiched between titanium dioxide (TiO2) were demonstrated as a transparent heat reflecting (THR) coating on glass for energy-saving window application. The main highlight is the utilization of Cu, a low-cost material, in-lieu of silver which is widely used in current commercial heat reflecting coating on glass. Color tunable transparent heat reflecting coating was realized through the design of multilayer structure and process optimization. The impact of thermal treatment on the overall performance of sputter deposited TiO2/Cu/TiO2 multilayer thin film on glass substrate is investigated in detail. Significant enhancement of transmittance in the visible range and reflectance in the infra-red (IR) region has been observed after thermal treatment of TiO2/Cu/TiO2 multilayer thin film at 500 °C due to the improvement of crystal quality of TiO2. Highest visible transmittance of 90% and IR reflectance of 85% at a wavelength of 1200 nm are demonstrated for the TiO2/Cu/TiO2 multilayer thin film after annealing at 500 °C. Performance of TiO2/Cu/TiO2 heat reflector coating decreases after thermal treatment at 600 °C. The wear performance of the TiO2/Cu/TiO2 multilayer structure has been evaluated through scratch hardness test. The present work shows promising characteristics of Cu-based THR coating for energy-saving building industry.

Evaluation of sliding window correlation performance for characterizing dynamic functional connectivity and brain states

PubMed Central

Shakil, Sadia; Lee, Chin-Hui; Keilholz, Shella Dawn

2016-01-01

A promising recent development in the study of brain function is the dynamic analysis of resting-state functional MRI scans, which can enhance understanding of normal cognition and alterations that result from brain disorders. One widely used method of capturing the dynamics of functional connectivity is sliding window correlation (SWC). However, in the absence of a “gold standard” for comparison, evaluating the performance of the SWC in typical resting-state data is challenging. This study uses simulated networks (SNs) with known transitions to examine the effects of parameters such as window length, window offset, window type, noise, filtering, and sampling rate on the SWC performance. The SWC time course was calculated for all node pairs of each SN and then clustered using the k-means algorithm to determine how resulting brain states match known configurations and transitions in the SNs. The outcomes show that the detection of state transitions and durations in the SWC is most strongly influenced by the window length and offset, followed by noise and filtering parameters. The effect of the image sampling rate was relatively insignificant. Tapered windows provide less sensitivity to state transitions than rectangular windows, which could be the result of the sharp transitions in the SNs. Overall, the SWC gave poor estimates of correlation for each brain state. Clustering based on the SWC time course did not reliably reflect the underlying state transitions unless the window length was comparable to the state duration, highlighting the need for new adaptive window analysis techniques. PMID:26952197

The use of solar simulation systems for producing artificial global radiation for the purpose of determining the heat load of rooms

NASA Technical Reports Server (NTRS)

Kalt, A. C.

1975-01-01

Certain climatic tests which require solar and sky radiation were carried out in the laboratory by using simulated global radiation. The advantages of such a method of measurement and the possibilities and limitations resulting from the simulation of global radiation are described. Experiments concerning the thermal load in rooms were conducted in order to test the procedure. In particular, the heat gain through a window with sunshade is discussed, a venetian blind between the panes of a double-glazed window being used in most cases.

High-Efficiency Low-Cost Solar Receiver for Use Ina a Supercritical CO 2 Recompression Cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sullivan, Shaun D.; Kesseli, James; Nash, James

This project has performed solar receiver designs for two supercritical carbon dioxide (sCO 2) power cycles. The first half of the program focused on a nominally 2 MWe power cycle, with a receiver designed for test at the Sandia Solar Thermal Test Facility. This led to an economical cavity-type receiver. The second half of the program focused on a 10 MWe power cycle, incorporating a surround open receiver. Rigorous component life and performance testing was performed in support of both receiver designs. The receiver performance objectives are set to conform to the US DOE goals of 6¢/kWh by 2020 .more » Key findings for both cavity-type and direct open receiver are highlighted below: A tube-based absorber design is impractical at specified temperatures, pressures and heat fluxes for the application; a plate-fin architecture however has been shown to meet performance and life targets; the $148/kW th cost of the design is significantly less than the SunShot cost target with a margin of 30%; the proposed receiver design is scalable, and may be applied to both modular cavity-type installations as well as large utility-scale open receiver installations; the design may be integrated with thermal storage systems, allowing for continuous high-efficiency electrical production during off-sun hours; costs associated with a direct sCO 2 receiver for a sCO 2 Brayton power cycle are comparable to those of a typical molten salt receiver; lifetimes in excess of the 90,000 hour goal are achievable with an optimal cell geometry; the thermal performance of the Brayton receiver is significantly higher than the industry standard, and enables at least a 30% efficiency improvement over the performance of the baseline steam-Rankine boiler/cycle system; brayton’s patent-pending quartz tube window provides a greater than five-percent efficiency benefit to the receiver by reducing both convection and radiation losses.« less

NOTE: The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields

NASA Astrophysics Data System (ADS)

Shaw, Adam; Nunn, John

2010-06-01

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45° to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 °C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible.

The feasibility of an infrared system for real-time visualization and mapping of ultrasound fields.

PubMed

Shaw, Adam; Nunn, John

2010-06-07

In treatment planning for ultrasound therapy, it is desirable to know the 3D structure of the ultrasound field. However, mapping an ultrasound field in 3D is very slow, with even a single planar raster scan taking typically several hours. Additionally, hydrophones that are used for field mapping are expensive and can be damaged in some therapy fields. So there is value in rapid methods which enable visualization and mapping of the ultrasound field in about 1 min. In this note we explore the feasibility of mapping the intensity distribution by measuring the temperature distribution produced in a thin sheet of absorbing material. A 0.2 mm thick acetate sheet forms a window in the wall of a water tank containing the transducer. The window is oriented at 45 degrees to the beam axis, and the distance from the transducer to the window can be varied. The temperature distribution is measured with an infrared camera; thermal images of the inclined plane could be viewed in real time or images could be captured for later analysis and 3D field reconstruction. We conclude that infrared thermography can be used to gain qualitative information about ultrasound fields. Thermal images are easily visualized with good spatial and thermal resolutions (0.044 mm and 0.05 degrees C in our system). The focus and field structure such as side lobes can be identified in real time from the direct video output. 3D maps and image planes at arbitrary orientations to the beam axis can be obtained and reconstructed within a few minutes. In this note we are primarily interested in the technique for characterization of high intensity focused ultrasound (HIFU) fields, but other applications such as physiotherapy fields are also possible.

Smart nickel oxide materials for the applications of energy efficiency and storage

NASA Astrophysics Data System (ADS)

Lin, Feng

The present dissertation studies nickel oxide-based materials for the application of electrochromic windows and lithium-air batteries. The materials were fabricated via radio frequency magnetron sputtering and subsequently post-treated with thermal evaporation and ozone exposure. The strategies to improve electrochromic performance of nickel oxide materials were investigated including compositional control, morphology tuning, modification of electronic structure and interface engineering (i.e., Li2O 2, graphene). The electrochemical properties of the resulting materials were characterized in lithium ion electrolytes. Extremely high performing nickel oxide-based electrochromic materials were obtained in terms of optical modulation, switching kinetics, bleached-state transparency and durability, which promise the implementation of these materials for practical smart windows. With the aid of advanced synchrotron X-ray absorption spectroscopy, it is reported for the first time that the electrochromic effect in multicomponent nickel oxide-based materials arises from the reversible formation of hole states in the NiO6 cluster accompanying with the reversible formation of Li2O2. The reversible formation of Li2O 2 was successfully leveraged with the study of electro-catalysts and cathode materials for lithium-air batteries. The reversibility of Li 2O2 was thoroughly investigated using soft X-ray absorption spectroscopy and theoretical simulation, which substantiates the promise of using electrochromic films as electro-catalysts and/or cathode materials in lithium-air batteries.

Intelligent Flexible Materials for Space Structures: Expandable Habitat Engineering Development Unit

NASA Technical Reports Server (NTRS)

Hinkle, Jon; Sharpe, George; Lin, John; Wiley, Cliff; Timmers, Richard

2010-01-01

Expandable habitable elements are an enabling technology for human exploration in space and on planetary surfaces. Large geometries can be deployed from a small launch volume, allowing greater mission capability while reducing mass and improving robustness over traditional rigid shells. This report describes research performed by ILC Dover under the Intelligent Flexible Materials for Space Structures program on the design and manufacture of softgoods for LaRC's Expandable Habitat Engineering Development Unit (EDU). The EDU is a full-scale structural test article of an expandable hybrid habitat, integrating an expandable softgoods center section with two rigid end caps. The design of the bladder, restraint layer and a mock-up Thermal Micrometeoroid Cover is detailed together with the design of the interface hardware used to attach them to the end caps. The integration and design of two windows and a floor are also covered. Analysis was performed to study the effects of the open weave design, and to determine the correct webbing and fabric configuration. Stress analyses were also carried out on the interfaces between the softgoods and the end caps and windows. Testing experimentally determined the strength of the fabric and straps, and component testing was used to proof several critical parts of the design. This program established new manufacturing and design techniques that can be applied to future applications in expandable structures.

Diamond-like carbon (DLC) thin film bioelectrodes: effect of thermal post-treatments and the use of Ti adhesion layer.

PubMed

Laurila, Tomi; Rautiainen, Antti; Sintonen, Sakari; Jiang, Hua; Kaivosoja, Emilia; Koskinen, Jari

2014-01-01

The effect of thermal post-treatments and the use of Ti adhesion layer on the performance of thin film diamond like carbon bioelectrodes (DLC) have been investigated in this work. The following results were obtained: (i) The microstructure of the DLC layer after the deposition was amorphous and thermal annealing had no marked effect on the structure, (ii) formation of oxygen containing SiOx and Ti[O,C] layers were detected at the Si/Ti and Ti/DLC interfaces with the help of transmission electron microscope (TEM), (iii) thermal post-treatments increased the polar fraction of the surface energy, (iv) cyclic voltammetry (CV) measurements showed that the DLC films had wide water windows and were stable in contact with dilute sulphuric acid and phosphate buffered saline (PBS) solutions, (v) use of Ti interlayer between Pt(Ir) microwire and DLC layer was crucial for the electrodes to survive the electrochemical measurements without the loss of adhesion of the DLC layer, (vi) DLC electrodes with small exposed Pt areas were an order of magnitude more sensitive towards dopamine than Pt electrodes and (vii) thermal post-treatments did not markedly change the electrochemical behavior of the electrodes despite the significant increase in the polar nature of the surfaces. It can be concluded that thin DLC bioelectrodes are stable under physiological conditions and can detect dopamine in micro molar range, but their sensitivity must be further improved. © 2013 Elsevier B.V. All rights reserved.

Thermal-envelope field measurements in an energy-efficient office/dormitory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, J.E.

1982-01-01

A 345 m/sup 2/ earth-covered structure located at the Oak Ridge National Laboratory is the focus of a DOE sponsored building-envelope research project. To heat the office/dormitory building over the 1981-1982 heating season would cost $1.70/m/sup 2/ ($0.16/ft/sup 2/), assuming $0.07/kWh. The thermal-integrity factor is 0.016 kWh/m/sup 2/ /sup 0/C (2.8 Btu/ft/sup 2/ /sup 0/F). A preliminary DOE-II model estimates the monthly electric energy needs for heating within 5% of field data derived estimates. DOE-II building simulations suggest that this earth-covered/passively heated office dormitory saves 30% for space heating and 26% for cooling compared to an energy efficient above grademore » structure. A preliminary winter energy balance has been generated from data collected in February and March providing a fractional breakdown of thermal losses and gains. A number of the energy-conserving component performances have been isolated; earth-covered roof, bermed wall, and nonvented trombe wall. The earth-covered roof system showed an overall thermal transmittance of 0.18 W/m/sup 2///sup 0/C (R=31 hr ft/sup 2/ /sup 0/F/Btu). The thermocouple wells located in the earth surrounding the building indicate the additional energy savings of burying over berming. For one week in February the trombe wall produced a 50% greater net thermal gain to the building then south facing windows per equivalent unit area.« less

Window Design Strategies to Conserve Energy. NBS Building Science Series 104.

ERIC Educational Resources Information Center

Hastings, S. Robert; Crenshaw, Richard W.

A multitude of design strategies are available to achieve energy-efficient windows. Opportunities for improving window performance fall into six groups: site, exterior appendages, frame, glazing, interior accessories, and building interior. Design strategies within these groups can improve one or more of the six energy functions of windows: solar…

Embryonic critical windows: changes in incubation temperature alter survival, hatchling phenotype, and cost of development in lake whitefish (Coregonus clupeaformis).

PubMed

Mueller, Casey A; Eme, John; Manzon, Richard G; Somers, Christopher M; Boreham, Douglas R; Wilson, Joanna Y

2015-04-01

The timing, success and energetics of fish embryonic development are strongly influenced by temperature. However, it is unclear if there are developmental periods, or critical windows, when oxygen use, survival and hatchling phenotypic characteristics are particularly influenced by changes in the thermal environment. Therefore, we examined the effects of constant incubation temperature and thermal shifts on survival, hatchling phenotype, and cost of development in lake whitefish (Coregonus clupeaformis) embryos. We incubated whitefish embryos at control temperatures of 2, 5, or 8 °C, and shifted embryos across these three temperatures at the end of gastrulation or organogenesis. We assessed hatch timing, mass at hatch, and yolk conversion efficiency (YCE). We determined cost of development, the amount of oxygen required to build a unit of mass, for the periods from fertilization-organogenesis, organogenesis-fin flutter, fin flutter-hatch, and for total development. An increase in incubation temperature decreased time to 50 % hatch (164 days at 2 °C, 104 days at 5 °C, and 63 days at 8 °C), survival decreased from 55 % at 2 °C, to 38 % at 5 °C, and 17 % at 8 °C, and hatchling yolk-free dry mass decreased from 1.27 mg at 2 °C to 0.61 mg at 8 °C. Thermal shifts altered time to 50 % hatch and hatchling yolk-free dry mass and revealed a critical window during gastrulation in which a temperature change reduced survival. YCE decreased and cost of development increased with increased incubation temperature, but embryos that hatched at 8 °C and were incubated at colder temperatures during fertilization-organogenesis had reduced cost. The relationship between cost of development and temperature was altered during fin flutter-hatch, indicating it may be a critical window during which temperature has the greatest impact on energetic processes. The increase in cost of development with an increase in temperature has not been documented in other fishes and suggests whitefish embryos are more energy efficient at colder temperatures.

Critical windows in embryonic development: Shifting incubation temperatures alter heart rate and oxygen consumption of Lake Whitefish (Coregonus clupeaformis) embryos and hatchlings.

PubMed

Eme, J; Mueller, C A; Manzon, R G; Somers, C M; Boreham, D R; Wilson, J Y

2015-01-01

Critical windows are periods of developmental susceptibility when the phenotype of an embryonic, juvenile or adult animal may be vulnerable to environmental fluctuations. Temperature has pervasive effects on poikilotherm physiology, and embryos are especially vulnerable to temperature shifts. To identify critical windows, we incubated whitefish embryos at control temperatures of 2°C, 5°C, or 8°C, and shifted treatments among temperatures at the end of gastrulation or organogenesis. Heart rate (fH) and oxygen consumption ( [Formula: see text] ) were measured across embryonic development, and [Formula: see text] was measured in 1-day old hatchlings. Thermal shifts, up or down, from initial incubation temperatures caused persistent changes in fH and [Formula: see text] compared to control embryos measured at the same temperature (2°C, 5°C, or 8°C). Most prominently, when embryos were measured at organogenesis, shifting incubation temperature after gastrulation significantly lowered [Formula: see text] or fH. Incubation at 2°C or 5°C through gastrulation significantly lowered [Formula: see text] (42% decrease) and fH (20% decrease) at 8°C, incubation at 2°C significantly lowered [Formula: see text] (40% decrease) and fH (30% decrease) at 5°C, and incubation at 5°C and 8°C significantly lowered [Formula: see text] at 2°C (27% decrease). Through the latter half of development, [Formula: see text] and fH in embryos were not different from control values for thermally shifted treatments. However, in hatchlings measured at 2°C, [Formula: see text] was higher in groups incubated at 5°C or 8°C through organogenesis, compared to 2°C controls (43 or 65% increase, respectively). Collectively, these data suggest that embryonic development through organogenesis represents a critical window of embryonic and hatchling phenotypic plasticity. This study presents an experimental design that identified thermally sensitive periods for fish embryos. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

PubMed

Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

2009-04-01

We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, <0.001 and 0.0002, respectively). When comparing measurement errors between stones of different composition in vitro, the error for calcium oxalate calculi was significantly different from the gold standard for all methods except bone window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x magnified bone windows was superior to 4.0x magnified soft tissue windows in measurement accuracy. Magnified bone window measurements were not statistically different from digital caliper measurements (mean underestimation vs digital caliper 0.3 mm, p = 0.4), while magnified soft tissue windows were statistically distinct (mean underestimation 1.4 mm, p = 0.001). In this study magnified bone windows were the most accurate method of stone measurements in vitro and in vivo. Therefore, we recommend the routine use of magnified bone windows for computerized tomography measurement of stones. In vitro the measurement error in calcium oxalate stones was greater than that in uric acid stones, suggesting that stone composition may be responsible for measurement inaccuracies.

Results of thermal test of metallic molybdenum disk target and fast-acting valve testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Virgo, M.; Chemerisov, S.; Gromov, R.

2016-12-01

This report describes the irradiation conditions for thermal testing of helium-cooled metallic disk targets that was conducted on March 9, 2016, at the Argonne National Laboratory electron linac. The four disks in this irradiation were pressed and sintered by Oak Ridge National Laboratory from molybdenum metal powder. Two of those disks were instrumented with thermocouples. Also reported are results of testing a fast-acting-valve system, which was designed to protect the accelerator in case of a target-window failure.

Mercury Thermal Hydraulic Loop (MTHL) Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felde, David K.; Crye, Jason Michael; Wendel, Mark W.

2017-03-01

The Spallation Neutron Source (SNS) is a high-power linear accelerator built at Oak Ridge National Laboratory (ORNL) which incorporates the use of a flowing liquid mercury target. The Mercury Thermal Hydraulic Loop (MTHL) was constructed to investigate and verify the heat transfer characteristics of liquid mercury in a rectangular channel. This report provides a compilation of previously reported results from the water-cooled and electrically heated straight and curved test sections that simulate the geometry of the window cooling channel in the target nose region.

Optimizing Battery Usage and Management for Long Life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Kandler; Shi, Ying; Wood, Eric

2016-06-16

This presentation discusses the impact of system design factors on battery aging and end of life. Topics include sizing of the SOC operating window, cell balancing and thermal management systems and their value in reducing pack degradation rates and cell imbalance growth over lifetime.

Disclosing the temperature of columnar jointing in lavas.

PubMed

Lamur, Anthony; Lavallée, Yan; Iddon, Fiona E; Hornby, Adrian J; Kendrick, Jackie E; von Aulock, Felix W; Wadsworth, Fabian B

2018-04-12

Columnar joints form by cracking during cooling-induced contraction of lava, allowing hydrothermal fluid circulation. A lack of direct observations of their formation has led to ambiguity about the temperature window of jointing and its impact on fluid flow. Here we develop a novel thermo-mechanical experiment to disclose the temperature of columnar jointing in lavas. Using basalts from Eyjafjallajökull volcano (Iceland) we show that contraction during cooling induces stress build-up below the solidus temperature (980 °C), resulting in localised macroscopic failure between 890 and 840 °C. This temperature window for incipient columnar jointing is supported by modelling informed by mechanical testing and thermal expansivity measurements. We demonstrate that columnar jointing takes place well within the solid state of volcanic rocks, and is followed by a nonlinear increase in system permeability of <9 orders of magnitude during cooling. Columnar jointing may promote advective cooling in magmatic-hydrothermal environments and fluid loss during geothermal drilling and thermal stimulation.

Oxygen effects on the performance of XeCl excimer lasers

NASA Astrophysics Data System (ADS)

Jeon, S. H.; Soh, B. S.; Kim, Y. P.

2018-03-01

We have investigated the degradation of window transmittance of XeCl excimer laser with oxygen, from which it was analyzed the laser performances such as stability of output energy, pre-ionization voltage, and spatial shift of laser beam. We found that oxygen suppressed the generation of by-products due to the chemical reactions between electrode material and chlorine. The degradation of transmittance ratio of laser window with oxygen improved from 10.4% to 1.4% after 20 million shots compared to without oxygen. Analyzing XPS spectrum for the contaminated window, we have confirmed that W and Cu on window surface were reduced in case of with oxygen, which means oxygen has a role to suppress the contamination on window surface.

Impact of window decrement rate on TCP performance in an adhoc network

NASA Astrophysics Data System (ADS)

Suherman; Hutasuhut, Arief T. W.; Badra, Khaldun; Al-Akaidi, Marwan

2017-09-01

Transmission control protocol (TCP) is a reliable transport protocol handling end to end connection in TCP/IP stack. It works well in copper or optical fibre link, but experiences increasing delay in wireless network. Further, TCP experiences multiple retransmissions due to higher collision probability within wireless network. The situation may get worsen in an ad hoc network. This paper examines the impact half window or window reduction rate to the overall TCP performances. The evaluation using NS-2 simulator shows that the smaller the window decrement rate results the smaller end to end delay. Delay is reduced to 17.05% in average when window decrement rate decreases. Average jitter also decreases 4.15%, while packet loss is not affected.

LENMODEL: A forward model for calculating length distributions and fission-track ages in apatite

NASA Astrophysics Data System (ADS)

Crowley, Kevin D.

1993-05-01

The program LENMODEL is a forward model for annealing of fission tracks in apatite. It provides estimates of the track-length distribution, fission-track age, and areal track density for any user-supplied thermal history. The program approximates the thermal history, in which temperature is represented as a continuous function of time, by a series of isothermal steps of various durations. Equations describing the production of tracks as a function of time and annealing of tracks as a function of time and temperature are solved for each step. The step calculations are summed to obtain estimates for the entire thermal history. Computational efficiency is maximized by performing the step calculations backwards in model time. The program incorporates an intuitive and easy-to-use graphical interface. Thermal history is input to the program using a mouse. Model options are specified by selecting context-sensitive commands from a bar menu. The program allows for considerable selection of equations and parameters used in the calculations. The program was written for PC-compatible computers running DOS TM 3.0 and above (and Windows TM 3.0 or above) with VGA or SVGA graphics and a Microsoft TM-compatible mouse. Single copies of a runtime version of the program are available from the author by written request as explained in the last section of this paper.

A thesis investigating the impact of energy related environmental factors on domestic window design

NASA Astrophysics Data System (ADS)

McEvoy, Michael Edward

In recent years the extent of glazing in houses has been tightly controlled by the Building Regulations in order to save energy. In addition guidelines derived from passive solar principles prescribe the distribution of domestic windows between elevations according to their orientation. This thesis studies the impact of these energy-related environmental factors on domestic window design. The first of these investigations determined the degree to which limitations on the area and arrangement of windows are significant in terms of daylighting. The experiments measured the effect that passive solar requirements and detailed aspects of window design have on the quality of daylighting in houses. The volume of background ventilation required for domestic accommodation has recently been increased. As a result, in a well-sealed construction, heat loss due to background ventilation becomes a larger part of the total heat loss and larger air movements become a potential cause of draughts. The ventilation experiment sought to establish the impact of these more onerous requirements on comfort within rooms. The third experiment combines these factors and asks the question: Could windows be actively involved in overcoming some of these difficulties by being used to preheat ventilation air in order to diminish the extent of heat loss and to alleviate the problem of cold draughts? Also by designing the window to reclaim heat from the room might it be possible to offset the window's thermal inadequacy? Through analysis of responses to a questionnaire and the use of optimisation techniques, scenarios were suggested for the future modification of windows in relation to energy and health expectations. The conclusions form a commentary on recent and future revisions to the Building Regulations and determine whether or not the Regulations facilitate the environmental engineering of windows as an active component of a building's whole environmental system.

Orion Hatch Window Testing

NASA Image and Video Library

2018-04-09

The first optical quality testing on a full window stack that is ready for installation in the docking hatch of NASA's Orion spacecraft is underway inside a laboratory in the Neil Armstrong Operations and Checkout Building at the agency's Kennedy Space Center in Florida. The test is being performed by a team from the center's Exploration Research and Technology Programs. The data from the tests will help improve the requirements for manufacturing tolerances on Orion's windows and verify how the window should perform in space. Orion is being prepared for its first integrated uncrewed flight atop NASA's Space Launch System rocket on Exploration Mission-1.

Temperature measurement using infrared imaging systems during turbine engine altitude testing

NASA Technical Reports Server (NTRS)

Burns, Maureen E.

1994-01-01

This report details the use of infrared imaging for temperature measurement and thermal pattern determination during simulated altitude engine testing in the NASA Lewis Propulsion Systems Laboratory. Three identical argon-cooled imaging systems were installed in the facility exhaust collector behind sapphire windows to look at engine internal surfaces. The report describes the components of each system, presents the specifics of the complicated installation, and explains the operation of the systems during engine testing. During the program, several problems emerged, such as argon contamination system, component overheating, cracked sapphire windows, and other unexplained effects. This report includes a summary of the difficulties as well as the solutions developed. The systems performed well, considering they were in an unusually harsh exhaust environment. Both video and digital data were recorded, and the information provided valuable material for the engineers and designers to quickly make any necessary design changes to the engine hardware cooling system. The knowledge and experience gained during this program greatly simplified the installation and use of the systems during later test programs in the facility. The infrared imaging systems have significantly enhanced the measurement capabilities of the facility, and have become an outstanding and versatile testing resource in the Propulsion Systems Laboratory.

Large reversible magnetocaloric effect in a Ni-Co-Mn-In magnetic shape memory alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, L.; Cong, D. Y.; Ma, L.

Reversibility of the magnetocaloric effect in materials with first-order magnetostructural transformation is of vital significance for practical magnetic refrigeration applications. Here, we report a large reversible magnetocaloric effect in a Ni49.8Co1.2Mn33.5In15.5 magnetic shape memory alloy. A large reversible magnetic entropy change of 14.6 J/(kg K) and a broad operating temperature window of 18 K under 5 T were simultaneously achieved, correlated with the low thermal hysteresis (-8 K) and large magnetic-field-induced shift of transformation temperatures (4.9 K/T) that lead to a narrow magnetic hysteresis (1.1 T) and small average magnetic hysteresis loss (48.4 J/kg under 5 T) as well. Furthermore,more » a large reversible effective refrigeration capacity (76.6 J/kg under 5 T) was obtained, as a result of the large reversible magnetic entropy change, broad operating temperature window, and small magnetic hysteresis loss. The large reversible magnetic entropy change and large reversible effective refrigeration capacity are important for improving the magnetocaloric performance, and the small magnetic hysteresis loss is beneficial to reducing energy dissipation during magnetic field cycle in potential applications.« less

All-Nonvacuum-Processed CIGS Solar Cells Using Scalable Ag NWs/AZO-Based Transparent Electrodes.

PubMed

Wang, Mingqing; Choy, Kwang-Leong

2016-07-06

With record cell efficiency of 21.7%, CIGS solar cells have demonstrated to be a very promising photovoltaic (PV) technology. However, their market penetration has been limited due to the inherent high cost of the cells. In this work, to lower the cost of CIGS solar cells, all nonvacuum-processed CIGS solar cells were designed and developed. CIGS absorber was prepared by the annealing of electrodeposited metallic layers in a chalcogen atmosphere. Nonvacuum-deposited Ag nanowires (NWs)/AZO transparent electrodes (TEs) with good transmittance (92.0% at 550 nm) and high conductivity (sheet resistance of 20 Ω/□) were used to replace the vacuum-sputtered window layer. Additional thermal treatment after device preparation was conducted at 220 °C for a few of minutes to improve both the value and the uniformity of the efficiency of CIGS pixel cell on 5 × 5 cm substrate. The best performance of the all-nonvacuum-fabricated CIGS solar cells showed an efficiency of 14.05% with Jsc of 34.82 mA/cm(2), Voc of 0.58 V, and FF of 69.60%, respectively, which is comparable with the efficiency of 14.45% of a reference cell using a sputtered window layer.

Pilot case-control study of paediatric falls from windows.

PubMed

Johnston, Brian D; Quistberg, D Alexander; Shandro, Jamie R; Partridge, Rebecca L; Song, Hyun Rae; Ebel, Beth E

2011-12-01

Unintentional falls from windows are an important cause of paediatric morbidity. There have been no controlled studies to identify modifiable environmental risk factors for window falls in young children. The authors have piloted a case-control study to test procedures for case identification, subject enrolment, and environmental data collection. Case windows were identified when a child 0-9 years old presented for care after a fall from that window. Control windows were identified (1) from the child's home and (2) from the home of an age- and gender-matched child seeking care for an injury diagnosis not related to a window fall. Study staff visited enrolled homes to collect window measurements and conduct window screen performance tests. The authors enrolled and collected data on 18 case windows, 18 in-home controls, and 14 matched community controls. Six potential community controls were contacted for every one enrolled. Families who completed the home visit viewed study procedures positively. Case windows were more likely than community controls to be horizontal sliders (100% vs 50%), to have deeper sills (6.28 vs 4.31 inches), to be higher above the exterior surface (183 vs 82 inches), and to have screens that failed below a threshold derived from the static pressure of a 3-year-old leaning against the mesh (60.0% vs 16.7%). Case windows varied very little from in-home controls. Case-control methodology can be used to study risk factors for paediatric falls from windows. Recruitment of community controls is challenging but essential, because in-home controls tend to be over-matched on important variables. A home visit allows direct measurement of window type, height, sill depth, and screen performance. These variables should all be investigated in subsequent, larger studies covering major housing markets.

Next generation smart window display using transparent organic display and light blocking screen.

PubMed

Kim, Gyeong Woo; Lampande, Raju; Choe, Dong Cheol; Ko, Ik Jang; Park, Jin Hwan; Pode, Ramchandra; Kwon, Jang Hyuk

2018-04-02

Transparent organic light emitting diodes (TOLED) have widespread applications in the next-generation display devices particularly in the large size transparent window and interactive displays. Herein, we report high performance and stable attractive smart window displays using facile process. Advanced smart window display is realized by integrating the high performance light blocking screen and highly transparent white OLED panel. The full smart window display reveals a maximum transmittance as high as 64.2% at the wavelength of 600 nm and extremely good along with tunable ambient contrast ratio (171.94:1) compared to that of normal TOLED (4.54:1). Furthermore, the performance decisive light blocking screen has demonstrated an excellent optical and electrical characteristics such as i) high transmittance (85.56% at 562nm) at light-penetrating state, ii) superior absorbance (2.30 at 562nm) in light interrupting mode, iii) high optical contrast (85.50 at 562 nm), iv) high optical stability for more than 25,000 cycle of driving, v) fast switching time of 1.9 sec, and vi) low driving voltage of 1.7 V. The experimental results of smart window display are also validated using optical simulation. The proposed smart window display technology allows us to adjust the intensity of daylight entering the system quickly and conveniently.

Purged window apparatus utilizing heated purge gas

DOEpatents

Ballard, Evan O.

1984-01-01

A purged window apparatus utilizing tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows, and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube. Use of this apparatus prevents backstreaming of gases under investigation which are flowing past the mouth of the mounting tube which would otherwise deposit on the windows. Lengthy spectroscopic investigations and analyses can thereby be performed without the necessity of interrupting the procedures in order to clean or replace contaminated windows.

Light valve based on nonimaging optics with potential application in cold climate greenhouses

NASA Astrophysics Data System (ADS)

Valerio, Angel A.; Mossman, Michele A.; Whitehead, Lorne A.

2014-09-01

We have evaluated a new concept for a variable light valve and thermal insulation system based on nonimaging optics. The system incorporates compound parabolic concentrators and can readily be switched between an open highly light transmissive state and a closed highly thermally insulating state. This variable light valve makes the transition between high thermal insulation and efficient light transmittance practical and may be useful in plant growth environments to provide both adequate sunlight illumination and thermal insulation as needed. We have measured light transmittance values exceeding 80% for the light valve design and achieved thermal insulation values substantially exceeding those of traditional energy efficient windows. The light valve system presented in this paper represents a potential solution for greenhouse food production in locations where greenhouses are not feasible economically due to high heating cost.

Progress on China nuclear data processing code system

NASA Astrophysics Data System (ADS)

Liu, Ping; Wu, Xiaofei; Ge, Zhigang; Li, Songyang; Wu, Haicheng; Wen, Lili; Wang, Wenming; Zhang, Huanyu

2017-09-01

China is developing the nuclear data processing code Ruler, which can be used for producing multi-group cross sections and related quantities from evaluated nuclear data in the ENDF format [1]. The Ruler includes modules for reconstructing cross sections in all energy range, generating Doppler-broadened cross sections for given temperature, producing effective self-shielded cross sections in unresolved energy range, calculating scattering cross sections in thermal energy range, generating group cross sections and matrices, preparing WIMS-D format data files for the reactor physics code WIMS-D [2]. Programming language of the Ruler is Fortran-90. The Ruler is tested for 32-bit computers with Windows-XP and Linux operating systems. The verification of Ruler has been performed by comparison with calculation results obtained by the NJOY99 [3] processing code. The validation of Ruler has been performed by using WIMSD5B code.

Optimizing Battery Usage and Management for Long Life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Kandler; Shi, Ying; Wood, Eric

2016-06-16

This presentation discusses the impact of system design factors on battery aging and end of life. Topics include sizing of the state-of-charge operating window, cell balancing, and thermal management systems and their value in reducing pack degradation rates and cell imbalance growth over lifetime.

Using cooperative control to manage uncertainties for Aquifer Thermal Energy Storage (ATES)

NASA Astrophysics Data System (ADS)

Jaxa-Rozen, Marc; Rostampour, Vahab; Kwakkel, Jan; Bloemendal, Martin

2017-04-01

Aquifer Thermal Energy Storage (ATES) technology can lead to major reductions in energy demand for heating and cooling in buildings. ATES systems rely on shallow aquifers to seasonally store thermal energy and have become popular in the Netherlands, where a combination of easily accessible aquifers and strict energy regulations makes the technology especially relevant. However, this rapid adoption has made their management in dense urban areas more challenging. For instance, thermal interferences between neighboring systems can degrade storage efficiency. Policies for the permitting and spatial layout of ATES thus tend to be conservative to ensure the performance of individual systems, but this limits the space available for new systems - leading to a trade-off between individual system performance, and the overall energy savings obtained from ATES in a given area. Furthermore, recent studies show that operational uncertainties contribute to poor outcomes under current planning practices; systems in the Netherlands typically use less than half of their permitted water volume. This further reduces energy savings compared to expectations and also leads to an over-allocation of subsurface space. In this context, this work investigates the potential of a more flexible approach for ATES planning and operation, under which neighboring systems coordinate their operation. This is illustrated with a three-building idealized case, using a model predictive control approach for two control schemes: a decoupled formulation, and a centralized scheme that aims to avoid interferences between neighboring systems (assuming perfect information exchange). These control schemes are compared across a range of scenarios for spatial layout, building energy demand, and climate, using a coupled agent-based/geohydrological simulation. The simulation indicates that centralized operation could significantly improve the spatial layout efficiency of ATES systems, by allowing systems to be placed more densely without penalizing their individual performance. This effectively relaxes the trade-off between individual system performance and collective energy savings as observed in the decoupled case. The continued adoption of ATES technology provides a window of opportunity to revisit existing practices for the layout and operation of urban ATES systems, as information exchange - supported by appropriate spatial planning - could offer significant potential towards improved performance under operational uncertainties.

Low-loss spinel windows for high-energy lasers

NASA Astrophysics Data System (ADS)

Kim, Woohong; Baker, Colin; Villalobos, Guillermo; Bayya, Shyam; Hunt, Michael; Sadowski, Bryan; Aggarwal, Ishwar; Sanghera, Jasbinder

2014-05-01

Ideal exit aperture windows for high-energy laser (HEL) should possess low absorption and scattering losses and be environmentally rugged and strong in order to protect the laser gain medium without compromising the light propagating through the window. Spinel is an ideal candidate for this application due to its high mechanical strength, high thermal conductivity, and excellent optical transmission between 0.2~5 μm. However, spinel ceramics fabricated with commercial powders often show inhomogeneity and suffer from absorption and scattering caused by various types of intrinsic and extrinsic impurities present in the powders. Here, we report on a convenient and economical powder purification method to significantly lower the absorption loss of transparent spinel ceramics using commercial powders. Acid washing was successfully used to reduce absorption loss in spinel ceramic fabricated using commercial powder from >20,000 ppm/cm down to 75 ppm/cm.

Options for reducing carbon dioxide emissions

NASA Astrophysics Data System (ADS)

Rosenfeld, Arthur H.; Price, Lynn

1992-03-01

Improvements in energy efficiency can significantly reduce the annual growth in greenhouse gas emissions. Such improvements occur when energy intensity is reduced; no reduction in energy services is required. Using the concept of ``cost of conserved energy'' to develop conservation supply curves similar to resource supply curves, researchers consistently find that electricity and natural gas savings of nearly 50% of current consumption are possible for U.S. buildings. Such reductions in energy consumption directly reduce emissions of greenhouse gases. To capture these savings, we must continue to develop energy-efficient technologies and strategies. This paper describes three recent energy-efficient technologies that benefitted from energy conservation research and development (R&D) funding: high-frequency ballasts, compact fluorescent lamps, and low-emissivity windows. Other advanced technologies and strategies of spectrally selective windows, superwindows, electrochromic windows, advanced insulation, low-flow showerheads, improved recessed lamp fixtures, whitening surfaces and planting urban trees, daylighting, and thermal energy storage are also discussed.

Launch Window Trade Analysis for the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Yu, Wayne H.; Richon, Karen

2014-01-01

The James Webb Space Telescope (JWST) is a large-scale space telescope mission designed to study fundamental astrophysical questions ranging from the formation of the universe to the origin of planetary systems and the origins of life. JWSTs orbit design is a Libration Point Orbit (LPO) around the Sun-Earth/Moon (SEM) L2 point for a planned mission lifetime of 10.5 years. The launch readiness period for JWST is from Oct 1st, 2018 November 30th, 2018. This paper presents the first launch window analysis for the JWST observatory using finite-burn modeling; previous analysis assumed a single impulsive midcourse correction to achieve the mission orbit. The physical limitations of the JWST hardware stemming primarily from propulsion, communication and thermal requirements alongside updated mission design requirements result in significant launch window within the launch readiness period. Future plans are also discussed.

Passivating Window/First Layer AR Coating for Space Solar Cells

NASA Technical Reports Server (NTRS)

Faur, Mircea; Faur, Maria; Bailey, S. G.; Flood, D. J.; Brinker, D. J.; Alterovitz, S. A.; Wheeler, D. R.; Matesscu, G.; Goradia, C.; Goradia, M.

2004-01-01

Chemically grown oxides, if well designed, offer excellent surface passivation of the emitter surface of space solar cells and can be used as effective passivating window/first layer AR coating. In this paper, we demonstrate the effectiveness of using a simple room temperature wet chemical technique to grow cost effective passivating layers on solar cell front surfaces after the front grid metallization step. These passivating layers can be grown both on planar and porous surfaces. Our results show that these oxide layers: (i) can effectively passivate the from the surface, (ii) can serve as an effective optical window/first layer AR coating, (iii) are chemically, thermally and UV stable, and (iv) have the potential of improving the BOL and especially the EOL efficiency of space solar cells. The potential of using this concept to simplify the III-V based space cell heterostructures while increasing their BOL and EOL efficiency is also discussed.

James Webb Space Telescope Launch Window Trade Analysis

NASA Technical Reports Server (NTRS)

Yu, Wayne; Richon, Karen

2014-01-01

The James Webb Space Telescope (JWST) is a large-scale space telescope mission designed to study fundamental astrophysical questions ranging from the formation of the universe to the origin of planetary systems and the origins of life. JWSTs orbit design is a Libration Point Orbit (LPO) around the Sun-EarthMoon (SEM) L2 point for a planned mission lifetime of 10.5 years. The launch readiness period for JWST is from Oct 1st, 2018 November 30th, 2018. This paper presents the first launch window analysis for the JWST observatory using finite-burn modeling; previous analysis assumed a single impulsive midcourse correction to achieve the mission orbit. The physical limitations of the JWST hardware stemming primarily from propulsion, communication and thermal requirements alongside updated mission design requirements result in significant launch window within the launch readiness period. Future plans are also discussed.

Effects of thermal increase on aerobic capacity and swim performance in a tropical inland fish.

PubMed

McDonnell, Laura H; Chapman, Lauren J

2016-09-01

Rising water temperature associated with climate change is increasingly recognized as a potential stressor for aquatic organisms, particularly for tropical ectotherms that are predicted to have narrow thermal windows relative to temperate ectotherms. We used intermittent flow resting and swimming respirometry to test for effects of temperature increase on aerobic capacity and swim performance in the widespread African cichlid Pseudocrenilabrus multicolor victoriae, acclimated for a week to a range of temperatures (2°C increments) between 24 and 34°C. Standard metabolic rate (SMR) increased between 24 and 32°C, but fell sharply at 34°C, suggesting either an acclimatory reorganization of metabolism or metabolic rate depression. Maximum metabolic rate (MMR) was elevated at 28 and 30°C relative to 24°C. Aerobic scope (AS) increased between 24 and 28°C, then declined to a level comparable to 24°C, but increased dramatically 34°C, the latter driven by the drop in SMR in the warmest treatment. Critical swim speed (Ucrit) was highest at intermediate temperature treatments, and was positively related to AS between 24 and 32°C; however, at 34°C, the increase in AS did not correspond to an increase in Ucrit, suggesting a performance cost at the highest temperature. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Fluorinated Phosphazene Co-solvents for Improved Thermal and Safety Performance in Lithium-Ion Battery Electrolytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harry W. Rollins; Mason K. Harrup; Eric J. Dufek

2014-10-01

The safety of lithium-ion batteries is coming under increased scrutiny as they are being adopted for large format applications especially in the vehicle transportation industry and for grid-scale energy storage. The primary short-comings of lithium-ion batteries are the flammability of the liquid electrolyte and sensitivity to high voltage and elevated temperatures. We have synthesized a series of non-flammable fluorinated phosphazene liquids and blended them with conventional carbonate solvents. While the use of these phosphazenes as standalone electrolytes is highly desirable, they simply do not satisfy all of the many requirements that must be met such as high LiPF6 solubility andmore » low viscosity, thus we have used them as additives and co-solvents in blends with typical carbonates. The physical and electrochemical properties of the electrolyte blends were characterized, and then the blends were used to build 2032-type coin cells which were evaluated at constant current cycling rates from C/10 to C/1. We have evaluated the performance of the electrolytes by determining the conductivity, viscosity, flash point, vapor pressure, thermal stability, electrochemical window, cell cycling data, and the ability to form solid electrolyte interphase (SEI) films. This paper presents our results on a series of chemically similar fluorinated cyclic phosphazene trimers, the FM series, which has exhibited numerous beneficial effects on battery performance, lifetimes, and safety aspects.« less

Improving energy sustainability for public buildings in Italian mountain communities.

PubMed

Mutani, Guglielmina; Cornaglia, Mauro; Berto, Massimo

2018-05-01

The objective of this work is to analyze and then optimize thermal energy consumptions of public buildings located within the mountain community of Lanzo, Ceronda and Casternone Valleys. Some measures have been proposed to reduce energy consumption and consequently the economic cost for energy production, as well as the harmful GHG emissions in the atmosphere. Initially, a study of the mountain territory has been carried out, because of its vast extension and climatic differences. Defined the communities and the buildings under investigation, energy dependant data were collected for the analysis of energy consumption monitoring: consumption data of three heating seasons, geometric buildings characteristics, type of opaque and transparent envelope, heating systems information with boiler performance and climatic data. Afterward, five buildings with critical energy performances were selected; for each of these buildings, different retrofit interventions have been hypothesized to reduce the energy consumption, with thermal insulation of vertical or horizontal structures, new windows or boiler substitution. The cost-optimal technique was used to choose the interventions that offered higher energy performance at lower costs; then a retrofit scenario has been planned with a specific financial investment. Finally, results showed possible future developments and scenarios related to buildings energy efficiency with regard to the topic of biomass exploitation and its local availability in this area. In this context, the biomass energy resource could to create a virtuous environmental, economic and social process, favouring also local development.

Thermal Windows on Brazilian Free-tailed Bats Facilitate Thermoregulation during Prolonged Flight

PubMed Central

Reichard, Jonathan D.; Prajapati, Suresh I.; Austad, Steven N.; Keller, Charles; Kunz, Thomas H.

2010-01-01

The Brazilian free-tailed bat (Tadarida brasiliensis) experiences challenging thermal conditions while roosting in hot caves, flying during warm daylight conditions, and foraging at cool high altitudes. Using thermal infrared cameras, we identified hot spots along the flanks of free-ranging Brazilian free-tailed bats, ventral to the extended wings. These hot spots are absent in syntopic cave myotis (Myotis velifer), a species that forages over relatively short distances, and does not engage in long-distance migration. We hypothesized that the hot spots, or “radiators,” on Brazilian free-tailed bats may be adaptations for migration, particularly in this long-distance, high-flying species. We examined the vasculature of radiators on Brazilian free-tailed bats with transillumination to characterize the unique arrangements of arteries and veins that are positioned perpendicular to the body in the proximal region of the wing. We hypothesized that these radiators aid in maintaining heat balance by flushing the uninsulated thermal window with warm blood, thereby dissipating heat while bats are flying under warm conditions, but shunting blood away and conserving heat when they are flying in cooler air at high altitudes. We also examined fluid-preserved specimens representing 122 species from 15 of 18 chiropteran families and radiators appeared present only in species in the family Molossidae, including both sedentary and migratory species and subspecies. Thus, the radiator appears to be a unique trait that may facilitate energy balance and water balance during sustained dispersal, foraging, and long-distance migration. PMID:20811514

Study of LANDSAT-D thematic mapper performance as applied to hydrocarbon exploration

NASA Technical Reports Server (NTRS)

Everett, J. R. (Principal Investigator)

1983-01-01

Two fully processed test tapes were enhanced and evaluated at scales up to 1:10,000, using both hardcopy output and interactive screen display. A large scale, the Detroit, Michigan scene shows evidence of an along line data slip every sixteenth line in TM channel 2. Very large scale products generated in false color using channels 1,3, and 4 should be very acceptable for interpretation at scales up to 1:50,000 and useful for change mapping probably up to scale 1:24,000. Striping visible in water bodies for both natural and color products indicates that the detector calibration is probably performing below preflight specification. For a set of 512 x 512 windows within the NE Arkansas scene, the variance-covariance matrices were computed and principal component analyses performed. Initial analysis suggests that the shortwave infrared TM 5 and 6 channels are a highly significant data source. The thermal channel (TM 7) shows negative correlation with TM 1 and 4.

Scale model testing of drogues for free drifting buoys

NASA Technical Reports Server (NTRS)

Vachon, W. A.

1973-01-01

Instrumented model drogue tests were conducted in a ship model towing tank. The purpose of the tests was to observe and measure deployment and drag characteristics of such shapes as parachutes, crossed vanes, and window shades which may be employed in conjunction with free drifting buoys. Both Froude and Reynolds scaling laws were applied while scaling to full scale relative velocities of from 0 to 0.2 knots. A weighted window shade drogue is recommended because of its performance, high drag coefficient, simplicity, and low cost. Detailed theoretical performance curves are presented for parachutes, crossed vanes, and window shade drogues. Theoretical estimates of depth locking accuracy and buoy-induced dynamic loads pertinent to window shade drogues are presented as a design aid. An example of a window shade drogue design is presented.

Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoessel, Chris

2013-11-13

This project developed a new high-performance R-10/high SHGC window design, reviewed market positioning and evaluated manufacturing solutions required for broad market adoption. The project objectives were accomplished by: identifying viable technical solutions based on modeling of modern and potential coating stacks and IGU designs; development of new coating material sets for HM thin film stacks, as well as improved HM IGU designs to accept multiple layers of HM films; matching promising new coating designs with new HM IGU designs to demonstrate performance gains; and, in cooperation with a window manufacturer, assess the potential for high-volume manufacturing and cost efficiency ofmore » a HM-based R-10 window with improved solar heat gain characteristics. A broad view of available materials and design options was applied to achieve the desired improvements. Gated engineering methodologies were employed to guide the development process from concept generation to a window demonstration. The project determined that a slightly de-rated window performance allows formulation of a path to achieve the desired cost reductions to support end consumer adoption.« less

Eye movements and the span of the effective stimulus in visual search.

PubMed

Bertera, J H; Rayner, K

2000-04-01

The span of the effective stimulus during visual search through an unstructured alphanumeric array was investigated by using eye-contingent-display changes while the subjects searched for a target letter. In one condition, a window exposing the search array moved in synchrony with the subjects' eye movements, and the size of the window was varied. Performance reached asymptotic levels when the window was 5 degrees. In another condition, a foveal mask moved in synchrony with each eye movement, and the size of the mask was varied. The foveal mask conditions were much more detrimental to search behavior than the window conditions, indicating the importance of foveal vision during search. The size of the array also influenced performance, but performance reached asymptote for all array sizes tested at the same window size, and the effect of the foveal mask was the same for all array sizes. The results indicate that both acuity and difficulty of the search task influenced the span of the effective stimulus during visual search.

Performance of solid state supercapacitors based on polymer electrolytes containing different ionic liquids

NASA Astrophysics Data System (ADS)

Tiruye, Girum Ayalneh; Muñoz-Torrero, David; Palma, Jesus; Anderson, Marc; Marcilla, Rebeca

2016-09-01

Four Ionic Liquid based Polymer Electrolytes (IL-b-PE) were prepared by blending a Polymeric Ionic Liquid, Poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (PILTFSI), with four different ionic liquids: 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) (IL-b-PE1), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR14FSI) (IL-b-PE2), 1-(2-hydroxy ethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HEMimTFSI) (IL-b-PE3), and 1-Butyl-1-methylpyrrolidinium dicyanamide, (PYR14DCA) (IL-b-PE4). Physicochemical properties of IL-b-PE such as ionic conductivity, thermal and electrochemical stability were found to be dependent on the IL properties. For instance, ionic conductivity was significantly higher for IL-b-PE2 and IL-b-PE4 containing IL with small size anions (FSI and DCA) than IL-b-PE1 and IL-b-PE3 bearing IL with bigger anion (TFSI). On the other hand, wider electrochemical stability window (ESW) was found for IL-b-PE1 and IL-b-PE2 having ILs with electrochemically stable pyrrolidinium cation and FSI and TFSI anions. Solid state Supercapacitors (SCs) were assembled with activated carbon electrodes and their electrochemical performance was correlated with the polymer electrolyte properties. Best performance was obtained with SC having IL-b-PE2 that exhibited a good compromise between ionic conductivity and electrochemical window. Specific capacitance (Cam), real energy (Ereal) & real power densities (Preal) as high as 150 F g-1, 36 Wh kg-1 & 1170 W kg-1 were found at operating voltage of 3.5 V.

High-Performance Flexible Organic Nano-Floating Gate Memory Devices Functionalized with Cobalt Ferrite Nanoparticles.

PubMed

Jung, Ji Hyung; Kim, Sunghwan; Kim, Hyeonjung; Park, Jongnam; Oh, Joon Hak

2015-10-07

Nano-floating gate memory (NFGM) devices are transistor-type memory devices that use nanostructured materials as charge trap sites. They have recently attracted a great deal of attention due to their excellent performance, capability for multilevel programming, and suitability as platforms for integrated circuits. Herein, novel NFGM devices have been fabricated using semiconducting cobalt ferrite (CoFe2O4) nanoparticles (NPs) as charge trap sites and pentacene as a p-type semiconductor. Monodisperse CoFe2O4 NPs with different diameters have been synthesized by thermal decomposition and embedded in NFGM devices. The particle size effects on the memory performance have been investigated in terms of energy levels and particle-particle interactions. CoFe2O4 NP-based memory devices exhibit a large memory window (≈73.84 V), a high read current on/off ratio (read I(on)/I(off)) of ≈2.98 × 10(3), and excellent data retention. Fast switching behaviors are observed due to the exceptional charge trapping/release capability of CoFe2O4 NPs surrounded by the oleate layer, which acts as an alternative tunneling dielectric layer and simplifies the device fabrication process. Furthermore, the NFGM devices show excellent thermal stability, and flexible memory devices fabricated on plastic substrates exhibit remarkable mechanical and electrical stability. This study demonstrates a viable means of fabricating highly flexible, high-performance organic memory devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cloud tolerance of remote sensing technologies to measure land surface temperature

USDA-ARS?s Scientific Manuscript database

Conventional means to estimate land surface temperature (LST) from space relies on the thermal infrared (TIR) spectral window and is limited to cloud-free scenes. To also provide LST estimates during periods with clouds, a new method was developed to estimate LST based on passive microwave (MW) obse...

Simple Estimation of Incident HIV Infection Rates in Notification Cohorts Based on Window Periods of Algorithms for Evaluation of Line-Immunoassay Result Patterns

PubMed Central

Schüpbach, Jörg; Gebhardt, Martin D.; Scherrer, Alexandra U.; Bisset, Leslie R.; Niederhauser, Christoph; Regenass, Stephan; Yerly, Sabine; Aubert, Vincent; Suter, Franziska; Pfister, Stefan; Martinetti, Gladys; Andreutti, Corinne; Klimkait, Thomas; Brandenberger, Marcel; Günthard, Huldrych F.

2013-01-01

Background Tests for recent infections (TRIs) are important for HIV surveillance. We have shown that a patient's antibody pattern in a confirmatory line immunoassay (Inno-Lia) also yields information on time since infection. We have published algorithms which, with a certain sensitivity and specificity, distinguish between incident (< = 12 months) and older infection. In order to use these algorithms like other TRIs, i.e., based on their windows, we now determined their window periods. Methods We classified Inno-Lia results of 527 treatment-naïve patients with HIV-1 infection < = 12 months according to incidence by 25 algorithms. The time after which all infections were ruled older, i.e. the algorithm's window, was determined by linear regression of the proportion ruled incident in dependence of time since infection. Window-based incident infection rates (IIR) were determined utilizing the relationship ‘Prevalence  =  Incidence x Duration’ in four annual cohorts of HIV-1 notifications. Results were compared to performance-based IIR also derived from Inno-Lia results, but utilizing the relationship ‘incident  =  true incident + false incident’ and also to the IIR derived from the BED incidence assay. Results Window periods varied between 45.8 and 130.1 days and correlated well with the algorithms' diagnostic sensitivity (R2 = 0.962; P<0.0001). Among the 25 algorithms, the mean window-based IIR among the 748 notifications of 2005/06 was 0.457 compared to 0.453 obtained for performance-based IIR with a model not correcting for selection bias. Evaluation of BED results using a window of 153 days yielded an IIR of 0.669. Window-based IIR and performance-based IIR increased by 22.4% and respectively 30.6% in 2008, while 2009 and 2010 showed a return to baseline for both methods. Conclusions IIR estimations by window- and performance-based evaluations of Inno-Lia algorithm results were similar and can be used together to assess IIR changes between annual HIV notification cohorts. PMID:23990968

Rigid thin windows for vacuum applications

DOEpatents

Meyer, Glenn Allyn; Ciarlo, Dino R.; Myers, Booth Richard; Chen, Hao-Lin; Wakalopulos, George

1999-01-01

A thin window that stands off atmospheric pressure is fabricated using photolithographic and wet chemical etching techniques and comprises at least two layers: an etch stop layer and a protective barrier layer. The window structure also comprises a series of support ribs running the width of the window. The windows are typically made of boron-doped silicon and silicon nitride and are useful in instruments such as electron beam guns and x-ray detectors. In an electron beam gun, the window does not impede the electrons and has demonstrated outstanding gun performance and survivability during the gun tube manufacturing process.

Lead-free BNT-based composite materials: enhanced depolarization temperature and electromechanical behavior.

PubMed

Bai, Wangfeng; Zheng, Peng; Wen, Fei; Zhang, Jingji; Chen, Daqin; Zhai, Jiwei; Ji, Zhenguo

2017-11-14

The development of (Bi 0.5 Na 0.5 )TiO 3 -based solid solutions with both high depolarization temperature T d and excellent piezoelectric and electromechanical properties for practical application is intractable because improved thermal stability is usually accompanied by a deterioration in piezoelectric and electromechanical performance. Herein, we report a 0-3 type 0.93(Bi 0.5 Na 0.5 )TiO 3 -0.07BaTiO 3  : 30 mol%ZnO composite (BNT-7BT : 0.3ZnO), in which the ZnO nanoparticles exist in two forms, to resolve the abovementioned long-standing obstacle. In this composite, Zn ions fill the boundaries of BNT-7BT grains, and residual Zn ions diffuse into the BNT-7BT lattice, as confirmed by XRD, Raman spectroscopy, and microstructure analysis. The BNT-7BT composite ceramics with a 0-3 type connectivity exhibited enhanced frequency-dependent electromechanical properties, fatigue characteristics, and thermal stabilities. More importantly, low poling field-driven large piezoelectric properties were observed for the composite ceramics as compared to the case of the pure BNT-7BT solid solution. A mechanism related to the ZnO-driven phase transition from the rhombohedral to tetragonal phase and built-in electric field to partially compensate the depolarization field was proposed to explain the achieved outstanding piezoelectric performance. This is the first time that the thermal stability, electromechanical behavior, and low poling field-driven high piezoelectric performance of BNT-based ceramics have been simultaneously optimized. Thus, our study provides a referential methodology to achieve novel piezoceramics with excellent piezoelectricity by composite engineering and opens up a new development window for the utilization of conventional BNT-based and other lead-free ceramics in practical applications.

Optical Absorption in Liquid Semiconductors

NASA Astrophysics Data System (ADS)

Bell, Florian Gene

An infrared absorption cell has been developed which is suitable for high temperature liquids which have absorptions in the range .1-10('3) cm('-1). The cell is constructed by clamping a gasket between two flat optical windows. This unique design allows the use of any optical windows chemically compatible with the liquid. The long -wavelength limit of the measurements is therefore limited only by the choice of the optical windows. The thickness of the cell can easily be set during assembly, and can be varied from 50 (mu)m to .5 cm. Measurements of the optical absorption edge were performed on the liquid alloy Se(,1-x)Tl(,x) for x = 0, .001, .002, .003, .005, .007, and .009, from the melting point up to 475(DEGREES)C. The absorption was found to be exponential in the photon energy over the experimental range from 0.3 eV to 1.2 eV. The absorption increased linearly with concentration according to the empirical relation (alpha)(,T)(h(nu)) = (alpha)(,1) + (alpha)(,2)x, and the absorption (alpha)(,1) was interpreted as the absorption in the absence of T1. (alpha)(,1) also agreed with the measured absorption in 100% Se at corresponding temperatures and energies. The excess absorption defined by (DELTA)(alpha) = (alpha)(,T)(h(nu))-(alpha)(,1) was interpreted as the absorption associated with Tl and was found to be thermally activated with an activation energy E(,t) = 0.5 eV. The exponential edge is explained as absorption on atoms immersed in strong electric fields surrounding ions. The strong fields give rise to an absorption tail similar to the Franz-Keldysh effect. A simple calculation is performed which is based on the Dow-Redfield theory of absorption in an electric field with excitonic effects included. The excess absorption at low photon energies is proportional to the square of the concentration of ions, which are proposed to exist in the liquid according to the relation C(,i) (PROPORTIONAL) x(' 1/2)(.)e('-E)t('/kT), which is the origin of the thermal activation and the proportionality to Tl concentration. The ionic model satisfactorily explains the observed concentration and temperature dependence of the absorption. It also provides for the first time, a universal explanation of the exponential edge in liquid semiconductors where charged defects are present, and provides a means of measuring the concentration of ions when the absorption can be calibrated.

Motorcycle detection and counting using stereo camera, IR camera, and microphone array

NASA Astrophysics Data System (ADS)

Ling, Bo; Gibson, David R. P.; Middleton, Dan

2013-03-01

Detection, classification, and characterization are the key to enhancing motorcycle safety, motorcycle operations and motorcycle travel estimation. Average motorcycle fatalities per Vehicle Mile Traveled (VMT) are currently estimated at 30 times those of auto fatalities. Although it has been an active research area for many years, motorcycle detection still remains a challenging task. Working with FHWA, we have developed a hybrid motorcycle detection and counting system using a suite of sensors including stereo camera, thermal IR camera and unidirectional microphone array. The IR thermal camera can capture the unique thermal signatures associated with the motorcycle's exhaust pipes that often show bright elongated blobs in IR images. The stereo camera in the system is used to detect the motorcyclist who can be easily windowed out in the stereo disparity map. If the motorcyclist is detected through his or her 3D body recognition, motorcycle is detected. Microphones are used to detect motorcycles that often produce low frequency acoustic signals. All three microphones in the microphone array are placed in strategic locations on the sensor platform to minimize the interferences of background noises from sources such as rain and wind. Field test results show that this hybrid motorcycle detection and counting system has an excellent performance.

[The progress in retrieving land surface temperature based on thermal infrared and microwave remote sensing technologies].

PubMed

Zhang, Jia-Hua; Li, Xin; Yao, Feng-Mei; Li, Xian-Hua

2009-08-01

Land surface temperature (LST) is an important parameter in the study on the exchange of substance and energy between land surface and air for the land surface physics process at regional and global scales. Many applications of satellites remotely sensed data must provide exact and quantificational LST, such as drought, high temperature, forest fire, earthquake, hydrology and the vegetation monitor, and the models of global circulation and regional climate also need LST as input parameter. Therefore, the retrieval of LST using remote sensing technology becomes one of the key tasks in quantificational remote sensing study. Normally, in the spectrum bands, the thermal infrared (TIR, 3-15 microm) and microwave bands (1 mm-1 m) are important for retrieval of the LST. In the present paper, firstly, several methods for estimating the LST on the basis of thermal infrared (TIR) remote sensing were synthetically reviewed, i. e., the LST measured with an ground-base infrared thermometer, the LST retrieval from mono-window algorithm (MWA), single-channel algorithm (SCA), split-window techniques (SWT) and multi-channels algorithm(MCA), single-channel & multi-angle algorithm and multi-channels algorithm & multi-angle algorithm, and retrieval method of land surface component temperature using thermal infrared remotely sensed satellite observation. Secondly, the study status of land surface emissivity (epsilon) was presented. Thirdly, in order to retrieve LST for all weather conditions, microwave remotely sensed data, instead of thermal infrared data, have been developed recently, and the LST retrieval method from passive microwave remotely sensed data was also introduced. Finally, the main merits and shortcomings of different kinds of LST retrieval methods were discussed, respectively.

Bulk and molecular-level characterization of laboratory-aged biomass burning organic aerosol from oak leaf and heartwood fuels

NASA Astrophysics Data System (ADS)

Fortenberry, Claire F.; Walker, Michael J.; Zhang, Yaping; Mitroo, Dhruv; Brune, William H.; Williams, Brent J.

2018-02-01

The chemical complexity of biomass burning organic aerosol (BBOA) greatly increases with photochemical aging in the atmosphere, necessitating controlled laboratory studies to inform field observations. In these experiments, BBOA from American white oak (Quercus alba) leaf and heartwood samples was generated in a custom-built emissions and combustion chamber and photochemically aged in a potential aerosol mass (PAM) flow reactor. A thermal desorption aerosol gas chromatograph (TAG) was used in parallel with a high-resolution time-of-flight aerosol mass spectrometer (AMS) to analyze BBOA chemical composition at different levels of photochemical aging. Individual compounds were identified and integrated to obtain relative decay rates for key molecules. A recently developed chromatogram binning positive matrix factorization (PMF) technique was used to obtain mass spectral profiles for factors in TAG BBOA chromatograms, improving analysis efficiency and providing a more complete determination of unresolved complex mixture (UCM) components. Additionally, the recently characterized TAG decomposition window was used to track molecular fragments created by the decomposition of thermally labile BBOA during sample desorption. We demonstrate that although most primary (freshly emitted) BBOA compounds deplete with photochemical aging, certain components eluting within the TAG thermal decomposition window are instead enhanced. Specifically, the increasing trend in the decomposition m/z 44 signal (CO2+) indicates formation of secondary organic aerosol (SOA) in the PAM reactor. Sources of m/z 60 (C2H4O2+), typically attributed to freshly emitted BBOA in AMS field measurements, were also investigated. From the TAG chemical speciation and decomposition window data, we observed a decrease in m/z 60 with photochemical aging due to the decay of anhydrosugars (including levoglucosan) and other compounds, as well as an increase in m/z 60 due to the formation of thermally labile organic acids within the PAM reactor, which decompose during TAG sample desorption. When aging both types of BBOA (leaf and heartwood), the AMS data exhibit a combination of these two contributing effects, causing limited change to the overall m/z 60 signal. Our observations demonstrate the importance of chemically speciated data in fully understanding bulk aerosol measurements provided by the AMS in both laboratory and field studies.

Exploiting the IR: Solar and stellar spectroscopy in the IR

NASA Technical Reports Server (NTRS)

Deming, Drake

1987-01-01

Recent instrumental advances have provided the capability to perform high resolution spectroscopy, in the thermal infrared region of the solar spectrum, with high sensitivity. The 8 to 12 micron region was extensively observed using Fourier transform (FTS) and laser heterodyne techniques. The continuous opacity of the solar atmosphere, due to H(-), increases with wavelength in the infrared region longward of 1.6 microns. Consequently thermal infrared observations probe the upper photosphere, and give an insight into the dynamics and structure of this region. The most notable spectral features in the 10 micron window include pure rotation lines of OH, and emission lines due to high-n states in MgI and AlI. The high-n lines due to MgI and AlI are important to solar and stellar physics because of their very large Zeeman sensitivity. The recent development of a cryogenic grating postdispenser for the FTS has allowed low-noise solar observations of these lines in 90 seconds. Limited mapping of the lines in a sunspot penumbra was performed, and gives information of the structure of the penumbral magnetic field. Although the MgI lines were detected in red giant spectra, instrumental sensitivity is not yet sufficient to see them in stars where significant magnetic fields are expected.

Synthesis, structural, thermal and optical studies of 1-ethyl-2,6-dimethyl-4-hydroxy pyridinium halides.

PubMed

Dhanuskodi, S; Manivannan, S; Kirschbaum, K

2006-05-15

1-Ethyl-2,6-dimethyl-4-hydroxy pyridinium chloride dihydrate and bromide dihydrate salts have been synthesized and their single crystals were grown by the slow evaporation of aqueous solution at 30 degrees C. The grown crystals were characterized by elemental analysis, FT-NMR and FT-IR techniques to confirm the formation of the expected compound. Optical transmittance window in aqueous solution was found to be 275-1100 nm by UV-vis-NIR technique. Thermogravimetric and differential thermal analyses reveal thermal stability and the presence of two water molecules in the crystal lattices. The crystal structure of chloride salt was also determined by X-ray diffraction method.

Heat exchange from the toucan bill reveals a controllable vascular thermal radiator.

PubMed

Tattersall, Glenn J; Andrade, Denis V; Abe, Augusto S

2009-07-24

The toco toucan (Ramphastos toco), the largest member of the toucan family, possesses the largest beak relative to body size of all birds. This exaggerated feature has received various interpretations, from serving as a sexual ornament to being a refined adaptation for feeding. However, it is also a significant surface area for heat exchange. Here we show the remarkable capacity of the toco toucan to regulate heat distribution by modifying blood flow, using the bill as a transient thermal radiator. Our results indicate that the toucan's bill is, relative to its size, one of the largest thermal windows in the animal kingdom, rivaling elephants' ears in its ability to radiate body heat.

Thermal Dependence of the Apparent Km of Glutathione Reductases from Three Plant Species

PubMed Central

Mahan, James R.; Burke, John J.; Orzech, Karen A.

1990-01-01

The thermal dependencies of the apparent Km of the glutathione reductases from spinach (Spinacia oleracea L.) corn (Zea mays L.), and cucumber (Cucumis sativus L.) were determined. The apparent Km of the enzymes were found to vary up to 9-fold between 12.5 and 45°C. Values of the apparent Km in excess of 200% of the observed minimum are suggested to be detrimental to the normal function of the enzyme. We propose the term “thermal kinetic window” to describe to the range of temperatures over which the apparent Km of the glutathione reductase is within 200% of its minimum and suggest that it may be a useful indicator of the limits of thermal stress for a given species. The thermal kinetic windows determined in this study are: <16°C for spinach, 23 to 32°C for corn, and 35 to 41°C for cucumber. PMID:16667543

Relationships between thermal maturity indices calculated using Arrhenius equation and Lopatin method: implications for petroleum exploration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, D.A.

1988-02-01

Thermal maturity can be calculated with time-temperature indices (TTI) based on the Arrhenius equation using kinetics applicable to a range of Types II and III kerogens. These TTIs are compared with TTI calculations based on the Lopatin method and are related theoretically (and empirically via vitrinite reflectance) to the petroleum-generation window. The TTIs for both methods are expressed mathematically as integrals of temperature combined with variable linear heating rates for selected temperature intervals. Heating rates control the thermal-maturation trends of buried sediments. Relative to Arrhenius TTIs, Lopatin TTIs tend to underestimate thermal maturity at high heating rates and overestimate itmore » as low heating rates. Complex burial histories applicable to a range of tectonic environments illustrate the different exploration decisions that might be made on the basis of independent results of these two thermal-maturation models. 15 figures, 8 tables.« less

Heterodyne Spectroscopy in the Thermal Infrared Region: A Window on Physics and Chemistry

NASA Technical Reports Server (NTRS)

Kostiuk, Theodor

2004-01-01

The thermal infrared region contains molecular bands of many of the most important species in gaseous astronomical sources. True shapes and frequencies of emission and absorption spectral lines from these constituents of planetary and stellar atmospheres contain unique information on local temperature and abundance distribution, non-thermal effects, composition, local dynamics and winds. Heterodyne spectroscopy in the thermal infrared can remotely measure true line shapes in relatively cool and thin regions and enable the retrieval of detailed information about local physics and chemistry. The concept and techniques for heterodyne detection will be discussed including examples of thermal infrared photomixers and instrumentation used in studies of several astronomical sources. Use of heterodyne detection to study non-LTE phenomena, planetary aurora, minor planetary species and gas velocities (winds) will be discussed. A discussion of future technological developments and relation to space flight missions will be addressed.

Signal to Noise Studies on Thermographic Data with Fabricated Defects for Defense Structures

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Rajic, Nik; Genest, Marc

2006-01-01

There is a growing international interest in thermal inspection systems for asset life assessment and management of defense platforms. The efficacy of flash thermography is generally enhanced by applying image processing algorithms to the observations of raw temperature. Improving the defect signal to noise ratio (SNR) is of primary interest to reduce false calls and allow for easier interpretation of a thermal inspection image. Several factors affecting defect SNR were studied such as data compression and reconstruction using principal component analysis and time window processing.

Efficient Simulation and Abuse Modeling of Mechanical-Electrochemical-Thermal Phenomena in Lithium-Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santhanagopalan, Shriram; Smith, Kandler A; Graf, Peter A

NREL's Energy Storage team is exploring the effect of mechanical crush of lithium ion cells on their thermal and electrical safety. PHEV cells, fresh as well as ones aged over 8 months under different temperatures, voltage windows, and charging rates, were subjected to destructive physical analysis. Constitutive relationship and failure criteria were developed for the electrodes, separator as well as packaging material. The mechanical models capture well, the various modes of failure across different cell components. Cell level validation is being conducted by Sandia National Laboratories.

The electrical and thermal transport properties of hybrid zigzag graphene-BN nanoribbons

NASA Astrophysics Data System (ADS)

Gao, Song; Lu, Wei; Zheng, Guo-Hui; Jia, Yalei; Ke, San-Huang

2017-06-01

The electron and phonon transport in hybrid graphene-BN zigzag nanoribbons are investigated by the nonequilibrium Green’s function method combined with density functional theory calculations. A 100% spin-polarized electron transport in a large energy window around the Fermi level is found and this behavior is independent of the ribbon width as long as there contain 3 zigzag carbon chains. The phonon transport calculations show that the ratio of C-chain number to BN-chain number will modify the thermal conductance of the hybrid nanoribbon in a complicated manner.

Study on thick film spin-on carbon hardmask

NASA Astrophysics Data System (ADS)

Kim, Taeho; Kim, Youngmin; Hwang, Sunmin; Lee, Hyunsoo; Han, Miyeon; Lim, Sanghak

2017-03-01

A thick spin-on carbon hardmask (SOH) material is designed to overcome inherent problems of amorphous deposited carbon layer (ACL) and thick photoresist. For ACL in use of semiconductor production process, especially when film thickness from sub-micrometer up to few micrometers is required, not only its inherent low transparency at long wavelength light often causes alignment problems with under layers, but also considerable variation of film thickness within a wafer can also cause patterning problems. To avoid these issues, a thick SOH is designed with monomers of high transparency and good solubility at the same time. In comparison with photoresist, the SOH has good etch resistance and high thermal stability, and it provides wide process window of decreased film thickness and increased thermal budget up to 400°C after processes such as high temperature deposition of SiON. In order to achieve high thickness along with uniform film, many solvent factors was considered such as solubility parameter, surface tension, vapor pressure, and others. By optimizing many solvent factors, we were able to develop a product with a good coating performance

Radiative Cooling: Principles, Progress, and Potentials

PubMed Central

Hossain, Md. Muntasir

2016-01-01

The recent progress on radiative cooling reveals its potential for applications in highly efficient passive cooling. This approach utilizes the maximized emission of infrared thermal radiation through the atmospheric window for releasing heat and minimized absorption of incoming atmospheric radiation. These simultaneous processes can lead to a device temperature substantially below the ambient temperature. Although the application of radiative cooling for nighttime cooling was demonstrated a few decades ago, significant cooling under direct sunlight has been achieved only recently, indicating its potential as a practical passive cooler during the day. In this article, the basic principles of radiative cooling and its performance characteristics for nonradiative contributions, solar radiation, and atmospheric conditions are discussed. The recent advancements over the traditional approaches and their material and structural characteristics are outlined. The key characteristics of the thermal radiators and solar reflectors of the current state‐of‐the‐art radiative coolers are evaluated and their benchmarks are remarked for the peak cooling ability. The scopes for further improvements on radiative cooling efficiency for optimized device characteristics are also theoretically estimated. PMID:27812478

Catalog of Window Taper Functions for Sidelobe Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doerry, Armin W.

Window taper functions of finite apertures are well-known to control undesirable sidelobes, albeit with performance trades. A plethora of various taper functions have been developed over the years to achieve various optimizations. We herein catalog a number of window functions, and com pare principal characteristics.

Is Latency to Test Deadline a Predictor of Student Test Performance?

ERIC Educational Resources Information Center

Landrum, R. Eric; Gurung, Regan A. R.

2013-01-01

When students are given a period or window of time to take an exam, is taking an exam earlier in the window (high latency to deadline) related to test scores? In Study 1, students (n = 236) were given windows of time to take online each of 13 quizzes and 4 exams. In Study 2, students (n = 251) similarly took 4 exams online within a test window. In…

Optimisation of the round window opening in cochlear implant surgery in wet and dry conditions: impact on intracochlear pressure changes.

PubMed

Mittmann, Philipp; Ernst, A; Mittmann, M; Todt, I

2016-11-01

To preserve residual hearing in cochlear implant candidates, the atraumatic insertion of the cochlea electrode has become a focus of cochlea implant research. In a previous study, intracochlear pressure changes during the opening of the round window membrane were investigated. In the current study, intracochlear pressure changes during opening of the round window membrane under dry and transfluid conditions were investigated. Round window openings were performed in an artificial cochlear model. Intracochlear pressure changes were measured using a micro-optical pressure sensor, which was placed in the apex. Openings of the round window membrane were performed under dry and wet conditions using a cannula and a diode laser. Statistically significant differences in the intracochlear pressure changes were seen between the different methods used for opening of the round window membrane. Lower pressure changes were seen by opening the round window membrane with the diode laser than with the cannula. A significant difference was seen between the dry and wet conditions. The atraumatic approach to the cochlea is assumed to be essential for the preservation of residual hearing. Opening of the round window under wet conditions produce a significant advantage on intracochlear pressure changes in comparison to dry conditions by limiting negative outward pressure.

Material Behavior of Window 7 Carrier Panel Tiles and Thermal Pane Fragments Recovered from the Space Shuttle Columbia

NASA Astrophysics Data System (ADS)

Arellano, Brenda R.

Since the end of the space shuttle program, a new generation spacecraft has been developed to transport humans back into space. NASA's Orion will carry a crew beyond low-earth orbit and the exploration of Mars may be possible in the future. Space safety becomes significant with human spaceflight and the risks are high. However, aerospace materials may provide opportunities to prevent future disasters. When the space shuttle Columbia disintegrated during re-entry in 2001, thousands of debris were collected for analysis. In contrast, when the Challenger space shuttle broke apart in 1986, all shuttle debris were buried. These tragic disasters are reminders of the importance of proper material selection and the concern of their performance in service. This research focused on investigating the effects of the debris recovered from the Columbia space shuttle after re-entry and break-up. Many of the components encountered unforeseen extreme temperatures, vibrations, and high stresses. The Columbia debris contained unique characteristics that have yet to be examined and the components for this study are the thermal protection system (TPS) carrier panel tiles and the thermal pane glass from the starboard orbiter Window 7. The alterations endured by the debris was studied through forensic materials characterization to investigate material interactions, material degradation, and thermal consequences. These materials played an essential role in the operation of the orbiter as they protected the underlying structural materials of the shuttle and underwent extreme temperatures. The methods and procedures for analyzing the debris included non-destructive and destructive evaluations. Non-destructive evaluations involved visual inspection, photographic documentation, 3D modeling, and surface elemental composition. The destructive analysis consisted of sectioning, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results obtained revealed metallic and oxide formations, flow trajectory, and the presence of other space shuttle materials. Determining the conditions of the debris after break-up is valuable because new developments for future manned spacecraft will require TPS. These materials must be continued to be studied aggressively to provide risk assessment for future missions. The findings of this investigation will identify the alterations on the debris and determine if these TPS materials are reliable for future spacecraft.

Performance limit of daytime radiative cooling in warm humid environment

NASA Astrophysics Data System (ADS)

Suichi, Takahiro; Ishikawa, Atsushi; Hayashi, Yasuhiko; Tsuruta, Kenji

2018-05-01

Daytime radiative cooling potentially offers efficient passive cooling, but the performance is naturally limited by the environment, such as the ambient temperature and humidity. Here, we investigate the performance limit of daytime radiative cooling under warm and humid conditions in Okayama, Japan. A cooling device, consisting of alternating layers of SiO2 and poly(methyl methacrylate) on an Al mirror, is fabricated and characterized to demonstrate a high reflectance for sunlight and a selective thermal radiation in the mid-infrared region. In the temperature measurement under the sunlight irradiation, the device shows 3.4 °C cooler than a bare Al mirror, but 2.8 °C warmer than the ambient of 35 °C. The corresponding numerical analyses reveal that the atmospheric window in λ = 16 ˜ 25 μm is closed due to a high humidity, thereby limiting the net emission power of the device. Our study on the humidity influence on the cooling performance provides a general guide line of how one can achieve practical passive cooling in a warm humid environment.

Effects of mixing eggs of different initial incubation time on the hatching pattern, chick embryonic development and post-hatch performance.

PubMed

Zhong, Zhentao; Yu, Yue; Jin, Shufang; Pan, Jinming

2018-01-01

The hatch window that varies from 24 to 48 h is known to influence post-hatch performance of chicks. A narrow hatch window is needed for commercial poultry industry to acquire a high level of uniformity of chick quality. Hatching synchronization observed in avian species presents possibilities in altering hatch window in artificial incubation. Layer eggs which were laid on the same day by a single breeder flock and stored for no more than two days started incubation 12 h apart to obtain developmental distinction. The eggs of different initial incubation time were mixed as rows adjacent to rows on day 12 of incubation. During the hatching period (since day 18), hatching time of individual eggs and hatch window were obtained by video recordings. Embryonic development (day 18 and 20) and post-hatch performance up to day 7 were measured. The manipulation of mixing eggs of different initial incubation time shortened the hatch window of late incubated eggs in the manipulated group by delaying the onset of hatching process, and improved the hatchability. Compared to the control groups, chick embryos or chicks in the egg redistribution group showed no significant difference in embryonic development and post-hatch performance up to day 7. We have demonstrated that eggs that were incubated with advanced eggs performed a narrow spread of hatch with higher hatchability, normal embryonic development as well as unaffected chick quality. This specific manipulation is applicable in industrial poultry production to shorten hatch window and improve the uniformity of chick quality.

Continuation of research into software for space operations support, volume 1

NASA Technical Reports Server (NTRS)

Collier, Mark D.; Killough, Ronnie; Martin, Nancy L.

1990-01-01

A prototype workstation executive called the Hardware Independent Software Development Environment (HISDE) was developed. Software technologies relevant to workstation executives were researched and evaluated and HISDE was used as a test bed for prototyping efforts. New X Windows software concepts and technology were introduced into workstation executives and related applications. The four research efforts performed included: (1) Research into the usability and efficiency of Motif (an X Windows based graphic user interface) which consisted of converting the existing Athena widget based HISDE user interface to Motif demonstrating the usability of Motif and providing insight into the level of effort required to translate an application from widget to another; (2) Prototype a real time data display widget which consisted of research methods for and prototyping the selected method of displaying textual values in an efficient manner; (3) X Windows performance evaluation which consisted of a series of performance measurements which demonstrated the ability of low level X Windows to display textural information; (4) Convert the Display Manager to X Window/Motif which is the application used by NASA for data display during operational mode.

Foale performs IFM at the science window in the U.S. Lab during Expedition 8

NASA Image and Video Library

2004-04-23

ISS008-E-22271 (23 April 2004) --- Astronaut C. Michael Foale, Expedition 8 commander and NASA ISS science officer, performs in-flight maintenance (IFM) on the nadir window in the Destiny laboratory of the International Space Station (ISS).

Multi-resolution analysis for region of interest extraction in thermographic nondestructive evaluation

NASA Astrophysics Data System (ADS)

Ortiz-Jaramillo, B.; Fandiño Toro, H. A.; Benitez-Restrepo, H. D.; Orjuela-Vargas, S. A.; Castellanos-Domínguez, G.; Philips, W.

2012-03-01

Infrared Non-Destructive Testing (INDT) is known as an effective and rapid method for nondestructive inspection. It can detect a broad range of near-surface structuring flaws in metallic and composite components. Those flaws are modeled as a smooth contour centered at peaks of stored thermal energy, termed Regions of Interest (ROI). Dedicated methodologies must detect the presence of those ROIs. In this paper, we present a methodology for ROI extraction in INDT tasks. The methodology deals with the difficulties due to the non-uniform heating. The non-uniform heating affects low spatial/frequencies and hinders the detection of relevant points in the image. In this paper, a methodology for ROI extraction in INDT using multi-resolution analysis is proposed, which is robust to ROI low contrast and non-uniform heating. The former methodology includes local correlation, Gaussian scale analysis and local edge detection. In this methodology local correlation between image and Gaussian window provides interest points related to ROIs. We use a Gaussian window because thermal behavior is well modeled by Gaussian smooth contours. Also, the Gaussian scale is used to analyze details in the image using multi-resolution analysis avoiding low contrast, non-uniform heating and selection of the Gaussian window size. Finally, local edge detection is used to provide a good estimation of the boundaries in the ROI. Thus, we provide a methodology for ROI extraction based on multi-resolution analysis that is better or equal compared with the other dedicate algorithms proposed in the state of art.

Fast Adaptive Thermal Camouflage Based on Flexible VO₂/Graphene/CNT Thin Films.

PubMed

Xiao, Lin; Ma, He; Liu, Junku; Zhao, Wei; Jia, Yi; Zhao, Qiang; Liu, Kai; Wu, Yang; Wei, Yang; Fan, Shoushan; Jiang, Kaili

2015-12-09

Adaptive camouflage in thermal imaging, a form of cloaking technology capable of blending naturally into the surrounding environment, has been a great challenge in the past decades. Emissivity engineering for thermal camouflage is regarded as a more promising way compared to merely temperature controlling that has to dissipate a large amount of excessive heat. However, practical devices with an active modulation of emissivity have yet to be well explored. In this letter we demonstrate an active cloaking device capable of efficient thermal radiance control, which consists of a vanadium dioxide (VO2) layer, with a negative differential thermal emissivity, coated on a graphene/carbon nanotube (CNT) thin film. A slight joule heating drastically changes the emissivity of the device, achieving rapid switchable thermal camouflage with a low power consumption and excellent reliability. It is believed that this device will find wide applications not only in artificial systems for infrared camouflage or cloaking but also in energy-saving smart windows and thermo-optical modulators.

Solar panels make really good cents.

PubMed

Hancock, Bobby

2009-02-01

Bobby Hancock, senior director of facility management for the Bloorview Kids Rehab facility in Toronto, describes how features such as a 37 kW penthouse roof solar array, thermal glazed windows, rainwater harvesting, and air handling units with variable speed drives and heat recovery wheels, contribute to the "green" credentials of Canada's largest children's rehabilitation centre.

TESTING AT NREL OF THE MINIPILOT SOLAR SYSTEM FOR HAZARDOUS WASTE THERMAL DESTRUCTION

EPA Science Inventory

A minipilot solar system (MSS) was built at MRI, transported to the National Renewable Energy Laboratory (NREL), and tested at NREL's high flux solar furnace. The MSS involved combustion of a liquid feed in a combustion reactor equipped with a quartz window at one end for solar i...

A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs

PubMed Central

Giomi, Folco; Pörtner, Hans-Otto

2013-01-01

Heat tolerance in aquatic ectotherms is constrained by a mismatch, occurring at high temperatures, between oxygen delivery and demand which compromises the maintenance of aerobic scope. The present study analyses how the wide thermal tolerance range of an eurythermal model species, the green crab Carcinus maenas is supported and limited by its ability to sustain efficient oxygen transport to tissues. Similar to other eurytherms, C. maenas sustains naturally occurring acute warming events through the integrated response of circulatory and respiratory systems. The response of C. maenas to warming can be characterized by two phases. During initial warming, oxygen consumption and heart rate increase, while stroke volume and haemolymph oxygen partial pressure decrease. During further warming, dissolved oxygen levels in the venous compartment decrease below the threshold of full haemocyanin oxygen saturation. The progressive release of haemocyanin bound oxygen with further warming follows an exponential pattern, thereby saving energy in oxygen transport and causing an associated leveling off of metabolic rate. According to the concept of oxygen and capacity limited thermal tolerance (OCLTT), this indicates that the thermal tolerance window is widened by the increasing contribution of haemocyanin oxygen transport and associated energy savings in cardiocirculation. Haemocyanin bound oxygen sustains cardiac performance to cover the temperature range experienced by C. maenas in the field. To our knowledge this is the first study providing evidence of a relationship between thermal tolerance and blood (haemolymph) oxygen transport in a eurythermal invertebrate. PMID:23720633

A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs.

PubMed

Giomi, Folco; Pörtner, Hans-Otto

2013-01-01

Heat tolerance in aquatic ectotherms is constrained by a mismatch, occurring at high temperatures, between oxygen delivery and demand which compromises the maintenance of aerobic scope. The present study analyses how the wide thermal tolerance range of an eurythermal model species, the green crab Carcinus maenas is supported and limited by its ability to sustain efficient oxygen transport to tissues. Similar to other eurytherms, C. maenas sustains naturally occurring acute warming events through the integrated response of circulatory and respiratory systems. The response of C. maenas to warming can be characterized by two phases. During initial warming, oxygen consumption and heart rate increase, while stroke volume and haemolymph oxygen partial pressure decrease. During further warming, dissolved oxygen levels in the venous compartment decrease below the threshold of full haemocyanin oxygen saturation. The progressive release of haemocyanin bound oxygen with further warming follows an exponential pattern, thereby saving energy in oxygen transport and causing an associated leveling off of metabolic rate. According to the concept of oxygen and capacity limited thermal tolerance (OCLTT), this indicates that the thermal tolerance window is widened by the increasing contribution of haemocyanin oxygen transport and associated energy savings in cardiocirculation. Haemocyanin bound oxygen sustains cardiac performance to cover the temperature range experienced by C. maenas in the field. To our knowledge this is the first study providing evidence of a relationship between thermal tolerance and blood (haemolymph) oxygen transport in a eurythermal invertebrate.

Continuation of research into software for space operations support: Conversion of the display manager to X Windows/Motif, volume 2

NASA Technical Reports Server (NTRS)

Collier, Mark D.; Killough, Ronnie; Martin, Nancy L.

1990-01-01

NASA is currently using a set of applications called the Display Builder and Display Manager. They run on Concurrent systems and heavily depend on the Graphic Kernel System (GKS). At this time however, these two applications would more appropriately be developed in X Windows, in which a low X is used for all actual text and graphics display and a standard widget set (such as Motif) is used for the user interface. Use of the X Windows will increase performance, improve the user interface, enhance portability, and improve reliability. Prototype of X Window/Motif based Display Manager provides the following advantages over a GKS based application: improved performance by using a low level X Windows, display of graphic and text will be more efficient; improved user interface by using Motif; Improved portability by operating on both Concurrent and Sun workstations; and Improved reliability.

The value of "liver windows" settings in the detection of small renal cell carcinomas on unenhanced computed tomography.

PubMed

Sahi, Kamal; Jackson, Stuart; Wiebe, Edward; Armstrong, Gavin; Winters, Sean; Moore, Ronald; Low, Gavin

2014-02-01

To assess if "liver window" settings improve the conspicuity of small renal cell carcinomas (RCC). Patients were analysed from our institution's pathology-confirmed RCC database that included the following: (1) stage T1a RCCs, (2) an unenhanced computed tomography (CT) abdomen performed ≤ 6 months before histologic diagnosis, and (3) age ≥ 17 years. Patients with multiple tumours, prior nephrectomy, von Hippel-Lindau disease, and polycystic kidney disease were excluded. The unenhanced CT was analysed, and the tumour locations were confirmed by using corresponding contrast-enhanced CT or magnetic resonance imaging studies. Representative single-slice axial, coronal, and sagittal unenhanced CT images were acquired in "soft tissue windows" (width, 400 Hounsfield unit (HU); level, 40 HU) and liver windows (width, 150 HU; level, 88 HU). In addition, single-slice axial, coronal, and sagittal unenhanced CT images of nontumourous renal tissue (obtained from the same cases) were acquired in soft tissue windows and liver windows. These data sets were randomized, unpaired, and were presented independently to 3 blinded radiologists for analysis. The presence or absence of suspicious findings for tumour was scored on a 5-point confidence scale. Eighty-three of 415 patients met the study criteria. Receiver operating characteristics (ROC) analysis, t test analysis, and kappa analysis were used. ROC analysis showed statistically superior diagnostic performance for liver windows compared with soft tissue windows (area under the curve of 0.923 vs 0.879; P = .0002). Kappa statistics showed "good" vs "moderate" agreement between readers for liver windows compared with soft tissue windows. Use of liver windows settings improves the detection of small RCCs on the unenhanced CT. Copyright © 2014 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Recalibration of the Multisensory Temporal Window of Integration Results from Changing Task Demands

PubMed Central

Mégevand, Pierre; Molholm, Sophie; Nayak, Ashabari; Foxe, John J.

2013-01-01

The notion of the temporal window of integration, when applied in a multisensory context, refers to the breadth of the interval across which the brain perceives two stimuli from different sensory modalities as synchronous. It maintains a unitary perception of multisensory events despite physical and biophysical timing differences between the senses. The boundaries of the window can be influenced by attention and past sensory experience. Here we examined whether task demands could also influence the multisensory temporal window of integration. We varied the stimulus onset asynchrony between simple, short-lasting auditory and visual stimuli while participants performed two tasks in separate blocks: a temporal order judgment task that required the discrimination of subtle auditory-visual asynchronies, and a reaction time task to the first incoming stimulus irrespective of its sensory modality. We defined the temporal window of integration as the range of stimulus onset asynchronies where performance was below 75% in the temporal order judgment task, as well as the range of stimulus onset asynchronies where responses showed multisensory facilitation (race model violation) in the reaction time task. In 5 of 11 participants, we observed audio-visual stimulus onset asynchronies where reaction time was significantly accelerated (indicating successful integration in this task) while performance was accurate in the temporal order judgment task (indicating successful segregation in that task). This dissociation suggests that in some participants, the boundaries of the temporal window of integration can adaptively recalibrate in order to optimize performance according to specific task demands. PMID:23951203

Development and performance test of a new high power RF window in S-band PLS-II LINAC

NASA Astrophysics Data System (ADS)

Hwang, Woon-Ha; Joo, Young-Do; Kim, Seung-Hwan; Choi, Jae-Young; Noh, Sung-Ju; Ryu, Ji-Wan; Cho, Young-Ki

2017-12-01

A prototype of RF window was developed in collaboration with the Pohang Accelerator Laboratory (PAL) and domestic companies. High power performance tests of the single RF window were conducted at PAL to verify the operational characteristics for its application in the Pohang Light Source-II (PLS-II) linear accelerator (Linac). The tests were performed in the in-situ facility consisting of a modulator, klystron, waveguide network, vacuum system, cooling system, and RF analyzing equipment. The test results with Stanford linear accelerator energy doubler (SLED) have shown no breakdown up to 75 MW peak power with 4.5 μs RF pulse width at a repetition rate of 10 Hz. The test results with the current operation level of PLS-II Linac confirm that the RF window well satisfies the criteria for PLS-II Linac operation.

Single-agent parallel window search

NASA Technical Reports Server (NTRS)

Powley, Curt; Korf, Richard E.

1991-01-01

Parallel window search is applied to single-agent problems by having different processes simultaneously perform iterations of Iterative-Deepening-A(asterisk) (IDA-asterisk) on the same problem but with different cost thresholds. This approach is limited by the time to perform the goal iteration. To overcome this disadvantage, the authors consider node ordering. They discuss how global node ordering by minimum h among nodes with equal f = g + h values can reduce the time complexity of serial IDA-asterisk by reducing the time to perform the iterations prior to the goal iteration. Finally, the two ideas of parallel window search and node ordering are combined to eliminate the weaknesses of each approach while retaining the strengths. The resulting approach, called simply parallel window search, can be used to find a near-optimal solution quickly, improve the solution until it is optimal, and then finally guarantee optimality, depending on the amount of time available.

Estimation of leaf water contents from mid- and thermal infrared spectra by coupling genetic algorithm and partial least squares regression

NASA Astrophysics Data System (ADS)

Arshad, Muhammad; Ullah, Saleem; Khurshid, Khurram; Ali, Asad

2017-10-01

Leaf Water Content (LWC) is an essential constituent of plant leaves that determines vegetation heath and its productivity. An accurate and on-time measurement of water content is crucial for planning irrigation, forecasting drought and predicting woodland fire. The retrieval of LWC from Visible to Shortwave Infrared (VSWIR: 0.4-2.5 μm) has been extensively investigated but little has been done in the Mid and Thermal Infrared (MIR and TIR: 2.50 -14.0 μm), windows of electromagnetic spectrum. This study is mainly focused on retrieval of LWC from Mid and Thermal Infrared, using Genetic Algorithm integrated with Partial Least Square Regression (PLSR). Genetic Algorithm fused with PLSR selects spectral wavebands with high predictive performance i.e., yields high adjusted-R2 and low RMSE. In our case, GA-PLSR selected eight variables (bands) and yielded highly accurate models with adjusted-R2 of 0.93 and RMSEcv equal to 7.1 %. The study also demonstrated that MIR is more sensitive to the variation in LWC as compared to TIR. However, the combined use of MIR and TIR spectra enhances the predictive performance in retrieval of LWC. The integration of Genetic Algorithm and PLSR, not only increases the estimation precision by selecting the most sensitive spectral bands but also helps in identifying the important spectral regions for quantifying water stresses in vegetation. The findings of this study will allow the future space missions (like HyspIRI) to position wavebands at sensitive regions for characterizing vegetation stresses.

Solar Thermal Propulsion Improvements at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Gerrish, Harold P.

2003-01-01

Solar Thermal Propulsion (STP) is a concept which operates by transferring solar energy to a propellant, which thermally expands through a nozzle. The specific impulse performance is about twice that of chemical combustions engines, since there is no need for an oxidizer. In orbit, an inflatable concentrator mirror captures sunlight and focuses it inside an engine absorber cavity/heat exchanger, which then heats the propellant. The primary application of STP is with upperstages taking payloads from low earth orbit to geosynchronous earth orbit or earth escape velocities. STP engines are made of high temperature materials since heat exchanger operation requires temperatures greater than 2500K. Refractory metals such as tungsten and rhenium have been examined. The materials must also be compatible with hot hydrogen propellant. MSFC has three different engine designs, made of different refractory metal materials ready to test. Future engines will be made of high temperature carbide materials, which can withstand temperatures greater than 3000K, hot hydrogen, and provide higher performance. A specific impulse greater than 1000 seconds greatly reduces the amount of required propellant. A special 1 OkW solar ground test facility was made at MSFC to test various STP engine designs. The heliostat mirror, with dual-axis gear drive, tracks and reflects sunlight to the 18 ft. diameter concentrator mirror. The concentrator then focuses sunlight through a vacuum chamber window to a small focal point inside the STP engine. The facility closely simulates how the STP engine would function in orbit. The flux intensity at the focal point is equivalent to the intensity at a distance of 7 solar radii from the sun.

Application of organic petrography in North American shale petroleum systems: A review

USGS Publications Warehouse

Hackley, Paul C.; Cardott, Brian J.

2016-01-01

Organic petrography via incident light microscopy has broad application to shale petroleum systems, including delineation of thermal maturity windows and determination of organo-facies. Incident light microscopy allows practitioners the ability to identify various types of organic components and demonstrates that solid bitumen is the dominant organic matter occurring in shale plays of peak oil and gas window thermal maturity, whereas oil-prone Type I/II kerogens have converted to hydrocarbons and are not present. High magnification SEM observation of an interconnected organic porosity occurring in the solid bitumen of thermally mature shale reservoirs has enabled major advances in our understanding of hydrocarbon migration and storage in shale, but suffers from inability to confirm the type of organic matter present. Herein we review organic petrography applications in the North American shale plays through discussion of incident light photographic examples. In the first part of the manuscript we provide basic practical information on the measurement of organic reflectance and outline fluorescence microscopy and other petrographic approaches to the determination of thermal maturity. In the second half of the paper we discuss applications of organic petrography and SEM in all of the major shale petroleum systems in North America including tight oil plays such as the Bakken, Eagle Ford and Niobrara, and shale gas and condensate plays including the Barnett, Duvernay, Haynesville-Bossier, Marcellus, Utica, and Woodford, among others. Our review suggests systematic research employing correlative high resolution imaging techniques and in situ geochemical probing is needed to better document hydrocarbon storage, migration and wettability properties of solid bitumen at the pressure and temperature conditions of shale reservoirs.

Electrostatic analyzer measurements of ionospheric thermal ion populations

DOE PAGES

Fernandes, P. A.; Lynch, K. A.

2016-07-09

Here, we define the observational parameter regime necessary for observing low-altitude ionospheric origins of high-latitude ion upflow/outflow. We present measurement challenges and identify a new analysis technique which mitigates these impediments. To probe the initiation of auroral ion upflow, it is necessary to examine the thermal ion population at 200-350 km, where typical thermal energies are tenths of eV. Interpretation of the thermal ion distribution function measurement requires removal of payload sheath and ram effects. We use a 3-D Maxwellian model to quantify how observed ionospheric parameters such as density, temperature, and flows affect in situ measurements of the thermalmore » ion distribution function. We define the viable acceptance window of a typical top-hat electrostatic analyzer in this regime and show that the instrument's energy resolution prohibits it from directly observing the shape of the particle spectra. To extract detailed information about measured particle population, we define two intermediate parameters from the measured distribution function, then use a Maxwellian model to replicate possible measured parameters for comparison to the data. Liouville's theorem and the thin-sheath approximation allow us to couple the measured and modeled intermediate parameters such that measurements inside the sheath provide information about plasma outside the sheath. We apply this technique to sounding rocket data to show that careful windowing of the data and Maxwellian models allows for extraction of the best choice of geophysical parameters. More widespread use of this analysis technique will help our community expand its observational database of the seed regions of ionospheric outflows.« less

Theoretical and experimental investigation on magneto-hydrodynamics of plasma window

DOE PAGES

Wang, S. Z.; Zhu, K.; Huang, S.; ...

2016-01-05

As a new device, we designed plasma window to use plasma discharge to separate atmosphere from vacuum with high difference of pressure. It has many excellent properties, being able to be used as available passage for ion beam with negligible energy loss, also impervious to radiation damage and thermal damage. Normally beam focusing by accelerators is not that easy to achieve within channel of small cross section. 10 mm diameter plasma window's experimental realization could contribute to its further application in accelerator system. In this paper, 10 mm diameter 60 mm long plasma window has first been designed and managedmore » to generate arc discharge with argon gas experimentally. Our result proves that it has the ability to separate at least 28.8 kPa (not the upper limit) from 360 Pa with 50 A direct current and 2.5 kW power supplied. Current increase leads to linear inlet pressure increase obviously, while it has less impact on outlet pressure and voltage, coming to the conclusion that the higher current of plasma discharge, the larger pressure difference it creates. Furthermore, theoretical analysis of 10 mm diameter plasma window in axis symmetrical configuration using argon also has been provided, in which a numerical 2D FLUENT-based magneto-hydrodynamic simulation model is settled. It has a good agreement with experimental result on voltage and mass flow rate when inlet pressure is increased.« less

An epidemiological assessment of the effect of ambient temperature on the incidence of preterm births: Identifying windows of susceptibility during pregnancy.

PubMed

Zheng, Xiangrong; Zhang, Weishe; Lu, Chan; Norbäck, Dan; Deng, Qihong

2018-05-01

It is well known that exposure to thermal stress during pregnancy can lead to an increased incidence of premature births. However, there is little known regarding window(s) of susceptibility during the course of a pregnancy. We attempted to identify possible windows of susceptibility in a cohort study of 3604 children in Changsha with a hot-summer and cold winter climatic characteristics. We examined the association between PTB and ambient temperature during different timing windows of pregnancy: conception month, three trimesters, birth month and entire pregnancy. We found a U-shaped relation between the prevalence of PTB and mean ambient temperature during pregnancy. Both high and low temperatures were associated with PTB risk, adjusted OR (95% CI) respectively 2.57 (1.98-3.33) and 2.39 (1.93-2.95) for 0.5 °C increase in high temperature range (>18.2°C) and 0.5°C decrease in low temperature range (< 18.2°C). Specifically, PTB was significantly associated with ambient temperature and extreme heat/cold days during conception month and the third trimester. Sensitivity analysis indicated that female fetus were more susceptible to the risk of ambient temperature. Our study indicates that the risk of preterm birth due to high or low temperature may exist early during the conception month. Copyright © 2018 Elsevier Ltd. All rights reserved.

Issues related to processability during the manufacture of thermoplastic composites using on-line consolidation techniques

NASA Astrophysics Data System (ADS)

Ghasemi Nejhad, M. N.

1993-04-01

The on-line consolidation of thermoplastic composites is a relatively new technology that can be used to manufacture composite parts with complex geometries. The localized melting/solidification technique employed in this process can reduce the residual stresses and allow for improved dimensional stability and performance. An additional advantage of this technique is the elimination of the curing steps which are necessary in the processing of thermoset-matrix composites. This article presents the effects of processing parameters on processability in on-line consolidation of thermoplastic composites for tape-laying and filament-winding processes employing anisotropic thermal analyses. The results show that the heater size, preheating conditions, and tow thickness can significantly affect the processing window which, in turn, affects the production rate and the quality of the parts.

A Near-Infrared and Thermal Imager for Mapping Titan's Surface Features

NASA Technical Reports Server (NTRS)

Aslam, S.; Hewagma, T.; Jennings, D. E.; Nixon, C.

2012-01-01

Approximately 10% of the solar insolation reaches the surface of Titan through atmospheric spectral windows. We will discuss a filter based imaging system for a future Titan orbiter that will exploit these windows mapping surface features, cloud regions, polar storms. In the near-infrared (NIR), two filters (1.28 micrometer and 1.6 micrometer), strategically positioned between CH1 absorption bands, and InSb linear array pixels will explore the solar reflected radiation. We propose to map the mid, infrared (MIR) region with two filters: 9.76 micrometer and 5.88-to-6.06 micrometers with MCT linear arrays. The first will map MIR thermal emission variations due to surface albedo differences in the atmospheric window between gas phase CH3D and C2H4 opacity sources. The latter spans the crossover spectral region where observed radiation transitions from being dominated by thermal emission to solar reflected light component. The passively cooled linear arrays will be incorporated into the focal plane of a light-weight thin film stretched membrane 10 cm telescope. A rad-hard ASIC together with an FPGA will be used for detector pixel readout and detector linear array selection depending on if the field-of-view (FOV) is looking at the day- or night-side of Titan. The instantaneous FOV corresponds to 3.1, 15.6, and 31.2 mrad for the 1, 5, and 10 micrometer channels, respectively. For a 1500 km orbit, a 5 micrometer channel pixel represents a spatial resolution of 91 m, with a FOV that spans 23 kilometers, and Titan is mapped in a push-broom manner as determined by the orbital path. The system mass and power requirements are estimated to be 6 kg and 5 W, respectively. The package is proposed for a polar orbiter with a lifetime matching two Saturn seasons.

Needs and opportunities for CFD-code validation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, B.L.

1996-06-01

The conceptual design for the ESS target consists of a horizontal cylinder containing a liquid metal - mercury is considered in the present study - which circulates by forced convection and carries away the waste heat generated by the spallation reactions. The protons enter the target via a beam window, which must withstand the thermal, mechanical and radiation loads to which it is subjected. For a beam power of 5MW, it is estimated that about 3.3MW of waste heat would be deposited in the target material and associated structures. it is intended to confirm, by detailed thermal-hydraulics calculations, that amore » convective flow of the liquid metal target material can effectively remove the waste heat. The present series of Computational Fluid Dynamics (CFD) calculations has indicated that a single-inlet Target design leads to excessive local overheating, but a multiple-inlet design, is coolable. With this option, inlet flow streams, two from the sides and one from below, merge over the target window, cooling the window itself in crossflow and carrying away the heat generated volumetrically in the mercury with a strong axial flow down the exit channel. The three intersecting streams form a complex, three-dimensional, swirling flow field in which critical heat transfer processes are taking place. In order to produce trustworthy code simulations, it is necessary that the mesh resolution is adequate for the thermal-hydraulic conditions encountered and that the physical models used by the code are appropriate to the fluid dynamic environment. The former relies on considerable user experience in the application of the code, and the latter assurance is best gained in the context of controlled benchmark activities where measured data are available. Such activities will serve to quantify the accuracy of given models and to identify potential problem area for the numerical simulation which may not be obvious from global heat and mass balance considerations.« less

Incubation history prior to the canonical thermosensitive period determines sex in the American alligator.

PubMed

McCoy, Jessica A; Parrott, Benjamin B; Rainwater, Thomas R; Wilkinson, Phillip M; Guillette, Louis J

2015-10-01

Despite the widespread occurrence of environmental sex determination (ESD) among vertebrates, our knowledge of the temporal dynamics by which environmental factors act on this process remains limited. In many reptiles, incubation temperature determines sex during a discrete developmental window just prior to and coincident with the differentiation of the gonads. Yet, there is substantial variation in sex ratios among different clutches of eggs incubated at identical temperatures during this period. Here, we test the hypothesis that temperatures experienced prior to the reported thermosensitive period for alligators (Alligator mississippiensis) can impact how the sex determination system responds to thermal cues later in development. Temperature shift experiments on eggs collected from the field within 24  h of oviposition were employed to decouple various maternal influences from thermal effects, and results demonstrate a previously undefined window of thermosensitivity occurring by stage 15 of embryonic development, six stages earlier than previously reported. We also examine the intrasexual expression of several male- and female-biased genes and show that while male-biased genes display no intrasexual differences, ovarian CYP19A1 (aromatase) transcript abundance differs by approximately twofold depending on thermal exposures experienced at early stages of embryonic development. These findings expand our understanding of the ESD in the alligator and provide the rationale for reevaluation of the temporal dynamics of sex determination in other crocodilians. © 2015 Society for Reproduction and Fertility.

Nanophotonics-enabled smart windows, buildings and wearables

NASA Astrophysics Data System (ADS)

Smith, Geoff; Gentle, Angus; Arnold, Matthew; Cortie, Michael

2016-06-01

Design and production of spectrally smart windows, walls, roofs and fabrics has a long history, which includes early examples of applied nanophotonics. Evolving nanoscience has a special role to play as it provides the means to improve the functionality of these everyday materials. Improvement in the quality of human experience in any location at any time of year is the goal. Energy savings, thermal and visual comfort indoors and outdoors, visual experience, air quality and better health are all made possible by materials, whose "smartness" is aimed at designed responses to environmental energy flows. The spectral and angle of incidence responses of these nanomaterials must thus take account of the spectral and directional aspects of solar energy and of atmospheric thermal radiation plus the visible and color sensitivity of the human eye. The structures required may use resonant absorption, multilayer stacks, optical anisotropy and scattering to achieve their functionality. These structures are, in turn, constructed out of particles, columns, ultrathin layers, voids, wires, pure and doped oxides, metals, polymers or transparent conductors (TCs). The need to cater for wavelengths stretching from 0.3 to 35 μm including ultraviolet-visible, near-infrared (IR) and thermal or Planck radiation, with a spectrally and directionally complex atmosphere, and both being dynamic, means that hierarchical and graded nanostructures often feature. Nature has evolved to deal with the same energy flows, so biomimicry is sometimes a useful guide.

Orion Hatch Window Testing

NASA Image and Video Library

2018-04-09

Inside a laboratory in the Neil Armstrong Operations and Checkout Building at NASA's Kennedy Space Center in Florida, Mark Nurge, Ph.D., at left, a physicist in the Applied Physics Lab with the center's Exploration Research and Technology Programs, and Bence Bartha, Ph.D., a specialist in non-destructive testing with URS Federal Services, are performing the first optical quality testing on a full window stack that is ready for installation in the docking hatch of NASA's Orion spacecraft. The data from the tests will help improve the requirements for manufacturing tolerances on Orion's windows and verify how the window should perform in space. Orion is being prepared for its first integrated uncrewed flight atop NASA's Space Launch System rocket on Exploration Mission-1.

Assessment of Environmentally Friendly Refrigerants for Window Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Shen, Bo

This paper presents technical assessment of environmentally friendly refrigerants for window air conditioners that currently use refrigerant R410A for residential and commercial applications. The alternative refrigerants that are studied for its replacement include R32, R600a, R290, R1234yf, R1234ze and a mixture of R32 (90% molar concentration) and R125 (10% molar concentration). Baseline experiments were performed on a window unit charged with R410A. The ORNL Heat Pump Design Model was calibrated with the baseline data and was used to assess the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and theirmore » suitability for window air conditioners.« less

Right-to-left-shunt detected by c-TCD using the orbital window in comparison with temporal bone windows.

PubMed

Kobayashi, Kazuto; Kimura, Kazumi; Iguchi, Yasuyuki; Sakai, Kenichirou; Aoki, Junya; Iwanaga, Takeshi; Shibazaki, Kensaku

2012-01-01

There have been some reports on right-to-left shunt as a cause of cryptogenic stroke. Although contrast transcranial Doppler (c-TCD) can detect RLS, an insufficient temporal window has occasionally restricted its applicability. Thus, we compared the rates of detecting RLS among temporal windows for the middle cerebral arteries (MCAs) and the orbital window for the internal carotid artery (ICA) on c-TCD. We used c-TCD to detect RLS in patients with suspected ischemic stroke. We enrolled patients who had both sufficient bilateral temporal windows for MCAs and a right orbital window for ICA and performed c-TCD using all three windows simultaneously. We enrolled 106 consecutive patients and identified microembolic signals (MES) in 30 (28%) of them. Among these 30 patients, 15 had MES from all 3 windows. When these 30 patients were defined as being positive for RLS, the rates of detection were 67%, 73%, and 80% from the right temporal, left temporal, and right orbital windows, respectively (P= .795). The right orbital window as well as the temporal window for c-TCD could detect RLS. Insonation from the orbital window should be useful for patients who lack temporal windows. Copyright © 2010 by the American Society of Neuroimaging.

Guide to Mathematics Released Items: Understanding Scoring. 2015

ERIC Educational Resources Information Center

Partnership for Assessment of Readiness for College and Careers, 2015

2015-01-01

The 2014-2015 administrations of the PARCC assessment included two separate test administration windows: the Performance-Based Assessment (PBA) and the End-of-Year (EOY), both of which were administered in paper-based and computer-based formats. The first window was for administration of the PBA, and the second window was for the administration of…

Waveguide transition with vacuum window for multiband dynamic nuclear polarization systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rybalko, Oleksandr; Bowen, Sean; Zhurbenko, Vitaliy

2016-05-15

A low loss waveguide transition section and oversized microwave vacuum window covering several frequency bands (94 GHz, 140 GHz, 188 GHz) is presented. The transition is compact and was optimized for multiband Dynamic Nuclear Polarization (DNP) systems in a full-wave simulator. The window is more broadband than commercially available windows, which are usually optimized for single band operation. It is demonstrated that high-density polyethylene with urethane adhesive can be used as a low loss microwave vacuum window in multiband DNP systems. The overall assembly performance and dimensions are found using full-wave simulations. The practical aspects of the window implementation inmore » the waveguide are discussed. To verify the design and simulation results, the window is tested experimentally at the three frequencies of interest.« less

Demonstration of a 100-kWth high-temperature solar thermochemical reactor pilot plant for ZnO dissociation

NASA Astrophysics Data System (ADS)

Koepf, E.; Villasmil, W.; Meier, A.

2016-05-01

Solar thermochemical H2O and CO2 splitting is a viable pathway towards sustainable and large-scale production of synthetic fuels. A reactor pilot plant for the solar-driven thermal dissociation of ZnO into metallic Zn has been successfully developed at the Paul Scherrer Institute (PSI). Promising experimental results from the 100-kWth ZnO pilot plant were obtained in 2014 during two prolonged experimental campaigns in a high flux solar simulator at PSI and a 1-MW solar furnace in Odeillo, France. Between March and June the pilot plant was mounted in the solar simulator and in-situ flow-visualization experiments were conducted in order to prevent particle-laden fluid flows near the window from attenuating transparency by blocking incoming radiation. Window flow patterns were successfully characterized, and it was demonstrated that particle transport could be controlled and suppressed completely. These results enabled the successful operation of the reactor between August and October when on-sun experiments were conducted in the solar furnace in order to demonstrate the pilot plant technology and characterize its performance. The reactor was operated for over 97 hours at temperatures as high as 2064 K; over 28 kg of ZnO was dissociated at reaction rates as high as 28 g/min.

Resource sharing on CSMA/CD networks in the presence of noise. M.S. Thesis

NASA Technical Reports Server (NTRS)

Dinschel, Duane Edward

1987-01-01

Resource sharing on carrier sense multiple access with collision detection (CSMA/CD) networks can be accomplished by using window-control algorithms for bus contention. The window-control algorithms are designed to grant permission to transmit to the station with the minimum contention parameter. Proper operation of the window-control algorithm requires that all stations sense the same state of the newtork in each contention slot. Noise causes the state of the network to appear as a collision. False collisions can cause the window-control algorithm to terminate without isolating any stations. A two-phase window-control protocol and approximate recurrence equation with noise as a parameter to improve the performance of the window-control algorithms in the presence of noise are developed. The results are compared through simulation, with the approximate recurrence equation yielding the best overall performance. Noise is even a bigger problem when it is not detected by all stations. In such cases it is possible for the window boundaries of the contending stations to become out of phase. Consequently, it is possible to isolate a station other than the one with the minimum contention parameter. To guarantee proper isolation of the minimum, a broadcast phase must be added after the termination of the algorithm. The protocol required to correct the window-control algorithm when noise is not detected by all stations is discussed.

Comparison of the Intensity of Ventilation at Windows Exchange in the Room - Case Study

NASA Astrophysics Data System (ADS)

Kapalo, Peter; Voznyak, Orest

2017-06-01

Doing the replacement of old wooden windows in a new plastic windows, in the old buildings, we get the great reducing of the building heat loss. Simpler maintenance and attendance of window is the next advantage. New windows are characterized by better tightness. The aim of the article is determination due to the performed experimental measurements, how much more are reduce the uncontrolled ventilation that is caused of the infiltration windows. In the article there is presented the experimental measurement of indoor air quality in the room in two phases. In the first phase there is the room installed by 55 year old wood window. In the second phase there is the same room installed by new plastic window. Due to the experimental measurement of indoor air quality it is calculated intensity of ventilation - infiltration. These results of ventilation intensity are reciprocally compared.

Shuttle Hypervelocity Impact Database

NASA Technical Reports Server (NTRS)

Hyde, James L.; Christiansen, Eric L.; Lear, Dana M.

2011-01-01

With three missions outstanding, the Shuttle Hypervelocity Impact Database has nearly 3000 entries. The data is divided into tables for crew module windows, payload bay door radiators and thermal protection system regions, with window impacts compromising just over half the records. In general, the database provides dimensions of hypervelocity impact damage, a component level location (i.e., window number or radiator panel number) and the orbiter mission when the impact occurred. Additional detail on the type of particle that produced the damage site is provided when sampling data and definitive analysis results are available. Details and insights on the contents of the database including examples of descriptive statistics will be provided. Post flight impact damage inspection and sampling techniques that were employed during the different observation campaigns will also be discussed. Potential enhancements to the database structure and availability of the data for other researchers will be addressed in the Future Work section. A related database of returned surfaces from the International Space Station will also be introduced.

Transparent Wood Smart Windows: Polymer Electrochromic Devices Based on Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulfonate) Electrodes.

PubMed

Lang, Augustus W; Li, Yuanyuan; De Keersmaecker, Michel; Shen, D Eric; Österholm, Anna M; Berglund, Lars; Reynolds, John R

2018-03-09

Transparent wood composites, with their high strength and toughness, thermal insulation, and excellent transmissivity, offer a route to replace glass for diffusely transmitting windows. Here, conjugated-polymer-based electrochromic devices (ECDs) that switch on-demand are demonstrated using transparent wood coated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a transparent conducting electrode. These ECDs exhibit a vibrant magenta-to-clear color change that results from a remarkably colorless bleached state. Furthermore, they require low energy and power inputs of 3 mWh m -2 at 2 W m -2 to switch due to a high coloration efficiency (590 cm 2  C -1 ) and low driving voltage (0.8 V). Each device component is processed with high-throughput methods, which highlights the opportunity to apply this approach to fabricate mechanically robust, energy-efficient smart windows on a large scale. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Accessing thermoplastic processing windows in metallic glasses using rapid capacitive discharge

PubMed Central

Kaltenboeck, Georg; Harris, Thomas; Sun, Kerry; Tran, Thomas; Chang, Gregory; Schramm, Joseph P.; Demetriou, Marios D.; Johnson, William L.

2014-01-01

The ability of the rapid-capacitive discharge approach to access optimal viscosity ranges in metallic glasses for thermoplastic processing is explored. Using high-speed thermal imaging, the heating uniformity and stability against crystallization of Zr35Ti30Cu7.5Be27.5 metallic glass heated deeply into the supercooled region is investigated. The method enables homogeneous volumetric heating of bulk samples throughout the entire supercooled liquid region at high rates (~105 K/s) sufficient to bypass crystallization throughout. The crystallization onsets at temperatures in the vicinity of the “crystallization nose” were identified and a Time-Temperature-Transformation diagram is constructed, revealing a “critical heating rate” for the metallic glass of ~1000 K/s. Thermoplastic process windows in the optimal viscosity range of 100–104 Pa·s are identified, being confined between the glass relaxation and the eutectic crystallization transition. Within this process window, near-net forging of a fine precision metallic glass part is demonstrated. PMID:25269892

SU-E-T-350: Verification of Gating Performance of a New Elekta Gating Solution: Response Kit and Catalyst System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, X; Cao, D; Housley, D

2014-06-01

Purpose: In this work, we have tested the performance of new respiratory gating solutions for Elekta linacs. These solutions include the Response gating and the C-RAD Catalyst surface mapping system.Verification measurements have been performed for a series of clinical cases. We also examined the beam on latency of the system and its impact on delivery efficiency. Methods: To verify the benefits of tighter gating windows, a Quasar Respiratory Motion Platform was used. Its vertical-motion plate acted as a respiration surrogate and was tracked by the Catalyst system to generate gating signals. A MatriXX ion-chamber array was mounted on its longitudinal-movingmore » platform. Clinical plans are delivered to a stationary and moving Matrix array at 100%, 50% and 30% gating windows and gamma scores were calculated comparing moving delivery results to the stationary result. It is important to note that as one moves to tighter gating windows, the delivery efficiency will be impacted by the linac's beam-on latency. Using a specialized software package, we generated beam-on signals of lengths of 1000ms, 600ms, 450ms, 400ms, 350ms and 300ms. As the gating windows get tighter, one can expect to reach a point where the dose rate will fall to nearly zero, indicating that the gating window is close to beam-on latency. A clinically useful gating window needs to be significantly longer than the latency for the linac. Results: As expected, the use of tighter gating windows improved delivery accuracy. However, a lower limit of the gating window, largely defined by linac beam-on latency, exists at around 300ms. Conclusion: The Response gating kit, combined with the C-RAD Catalyst, provides an effective solution for respiratorygated treatment delivery. Careful patient selection, gating window design, even visual/audio coaching may be necessary to ensure both delivery quality and efficiency. This research project is funded by Elekta.« less

Indocyanine green fluorescence in second near-infrared (NIR-II) window

PubMed Central

Bhavane, Rohan; Ghaghada, Ketan B.; Vasudevan, Sanjeev A.; Kaay, Alexander; Annapragada, Ananth

2017-01-01

Indocyanine green (ICG), a FDA approved near infrared (NIR) fluorescent agent, is used in the clinic for a variety of applications including lymphangiography, intra-operative lymph node identification, tumor imaging, superficial vascular imaging, and marking ischemic tissues. These applications operate in the so-called “NIR-I” window (700–900 nm). Recently, imaging in the “NIR-II” window (1000–1700 nm) has attracted attention since, at longer wavelengths, photon absorption, and scattering effects by tissue components are reduced, making it possible to image deeper into the underlying tissue. Agents for NIR-II imaging are, however, still in pre-clinical development. In this study, we investigated ICG as a NIR-II dye. The absorbance and NIR-II fluorescence emission of ICG were measured in different media (PBS, plasma and ethanol) for a range of ICG concentrations. In vitro and in vivo testing were performed using a custom-built spectral NIR assembly to facilitate simultaneous imaging in NIR-I and NIR-II window. In vitro studies using ICG were performed using capillary tubes (as a simulation of blood vessels) embedded in Intralipid solution and tissue phantoms to evaluate depth of tissue penetration in NIR-I and NIR-II window. In vivo imaging using ICG was performed in nude mice to evaluate vascular visualization in the hind limb in the NIR-I and II windows. Contrast-to-noise ratios (CNR) were calculated for comparison of image quality in NIR-I and NIR-II window. ICG exhibited significant fluorescence emission in the NIR-II window and this emission (similar to the absorption profile) is substantially affected by the environment of the ICG molecules. In vivo imaging further confirmed the utility of ICG as a fluorescent dye in the NIR-II domain, with the CNR values being ~2 times those in the NIR-I window. The availability of an FDA approved imaging agent could accelerate the clinical translation of NIR-II imaging technology. PMID:29121078

Light-induced thermodiffusion in two-component media

NASA Astrophysics Data System (ADS)

Ivanov, V.; Ivanova, G.; Okishev, K.; Khe, V.

2017-01-01

We have theoretically studied the optical transmittance response of thin cell with liquid containing absorbing nanoparticles in a Gaussian beam field. The transmittance spatial changing is caused by thermal diffusion phenomenon (Soret effect) which produces the variations of concentration of absorbing nanoparticles. The thickness of optical cell (including windows) is significantly less than the size of the beam. As a result, an exact analytical expression for the one dimensional thermal task is derived, taking into account the Soret feedback that leads to the temperature rising on the axis of a Gaussian beam. We have experimentally studied this phenomenon in carbon nanosuspension.

Benchmarks for Enhanced Network Performance: Hands-On Testing of Operating System Solutions to Identify the Optimal Application Server Platform for the Graduate School of Business and Public Policy

DTIC Science & Technology

2010-09-01

for Applied Mathematics. Kennedy, R. C. (2009a). Clocking Windows netbook performance. Retrieved on 08/14/2010, from http...podcasts.infoworld.com/d/hardware/clocking-windows- netbook -performance-883?_kip_ipx=1177119066-1281460794 Kennedy, R. C. (2009b). OfficeBench 7: A cool new way to

Trade-offs in thermal adaptation: the need for a molecular to ecological integration.

PubMed

Pörtner, Hans O; Bennett, Albert F; Bozinovic, Francisco; Clarke, Andrew; Lardies, Marco A; Lucassen, Magnus; Pelster, Bernd; Schiemer, Fritz; Stillman, Jonathon H

2006-01-01

Through functional analyses, integrative physiology is able to link molecular biology with ecology as well as evolutionary biology and is thereby expected to provide access to the evolution of molecular, cellular, and organismic functions; the genetic basis of adaptability; and the shaping of ecological patterns. This paper compiles several exemplary studies of thermal physiology and ecology, carried out at various levels of biological organization from single genes (proteins) to ecosystems. In each of those examples, trade-offs and constraints in thermal adaptation are addressed; these trade-offs and constraints may limit species' distribution and define their level of fitness. For a more comprehensive understanding, the paper sets out to elaborate the functional and conceptual connections among these independent studies and the various organizational levels addressed. This effort illustrates the need for an overarching concept of thermal adaptation that encompasses molecular, organellar, cellular, and whole-organism information as well as the mechanistic links between fitness, ecological success, and organismal physiology. For this data, the hypothesis of oxygen- and capacity-limited thermal tolerance in animals provides such a conceptual framework and allows interpreting the mechanisms of thermal limitation of animals as relevant at the ecological level. While, ideally, evolutionary studies over multiple generations, illustrated by an example study in bacteria, are necessary to test the validity of such complex concepts and underlying hypotheses, animal physiology frequently is constrained to functional studies within one generation. Comparisons of populations in a latitudinal cline, closely related species from different climates, and ontogenetic stages from riverine clines illustrate how evolutionary information can still be gained. An understanding of temperature-dependent shifts in energy turnover, associated with adjustments in aerobic scope and performance, will result. This understanding builds on a mechanistic analysis of the width and location of thermal windows on the temperature scale and also on study of the functional properties of relevant proteins and associated gene expression mechanisms.

Activity Recognition on Streaming Sensor Data.

PubMed

Krishnan, Narayanan C; Cook, Diane J

2014-02-01

Many real-world applications that focus on addressing needs of a human, require information about the activities being performed by the human in real-time. While advances in pervasive computing have lead to the development of wireless and non-intrusive sensors that can capture the necessary activity information, current activity recognition approaches have so far experimented on either a scripted or pre-segmented sequence of sensor events related to activities. In this paper we propose and evaluate a sliding window based approach to perform activity recognition in an on line or streaming fashion; recognizing activities as and when new sensor events are recorded. To account for the fact that different activities can be best characterized by different window lengths of sensor events, we incorporate the time decay and mutual information based weighting of sensor events within a window. Additional contextual information in the form of the previous activity and the activity of the previous window is also appended to the feature describing a sensor window. The experiments conducted to evaluate these techniques on real-world smart home datasets suggests that combining mutual information based weighting of sensor events and adding past contextual information into the feature leads to best performance for streaming activity recognition.

Performance characteristics of proximity focused ultraviolet image converters

NASA Technical Reports Server (NTRS)

Williams, J. T.; Feibelman, W. A.

1973-01-01

Performance characteristics of Bendix type BX 8025-4522 proximity focused image tubes for ultraviolet to visible light conversion are presented. Quantum efficiency, resolution, background, geometric distortion, and environmental test results are discussed. The converters use magnesium fluoride input windows with Cs - Te photocathodes, and P-11 phosphors on fiber optic output windows.

Performance characteristics of proximity focused ultraviolet image converters

NASA Technical Reports Server (NTRS)

Williams, J. T.; Feibelman, W. A.

1973-01-01

Performance characteristics of Bendix type BX 8025-4522 proximity focused image tubes for UV to visible light conversion are presented. Quantum efficiency, resolution, background, geometric distortion, and environmental test results are discussed. The converters use magnesium fluoride input windows with Cs-Te photocathodes and P-11 phosphors on fiber optic output windows.

Energy Conservation in the Home. Performance Based Lesson Plans.

ERIC Educational Resources Information Center

Alabama State Dept. of Education, Montgomery. Home Economics Service.

These ten performance-based lesson plans concentrate on tasks related to energy conservation in the home. They are (1) caulk cracks, holes, and joints; (2) apply weatherstripping to doors and windows; (3) add plastic/solar screen window covering; (4) arrange furniture for saving energy; (5) set heating/cooling thermostat; (6) replace faucet…

Thermal envelope field measurements in an energy-efficient office and dormitory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, J.E.

1983-04-01

A 345-m/sup 2/ earth-covered structure located at Oak Ridge National Laboratory is the focus of a DOE-sponsored building envelope research project. Based on field-measured data, heating the office and dormitory building over the 1981-1982 heating season cost $1.70/m/sup 2/ ($0.16/ft/sup 2/), assuming the cost of electricity to be $0.057/kWh. The building's thermal integrity factor is 0.016 kWh/m/sup 2/ /sup 0/C (2.8 Btu/ft/sup 2/ /sup 0/F). A preliminary DOE-2 model estimates the monthly electric energy needs for heating to be within 5% of our field data-derived estimates. DOE-2 building simulations suggest that this earth-covered, passively solar heated office dormitory saves 30%more » of the space heating and 26% of the cooling costs of an energy-efficient above grade structure. A preliminary winter energy balance has been generated from data collected in February and March and provides a fractional breakdown of thermal losses and gains. Performances have been isolated for several of the energy-conserving components: the earth-covered roof, the bermed wall, and the nonvented Trombe wall. The earth-covered roof system showed an overall thermal transmittance of 0.18 W/m/sup 2/ /sup 0/C (R = 31 h ft/sup 2/ /sup 0/F Btu/sup -1/). The thermocouple wells in the earth surrounding the building indicate that burying a wall is more energy efficient than berming. During one week in February, the Trombe wall produced a 50% greater net thermal gain to the building than an equivalent area of south-facing windows.« less

Replacement Windows Define the Newly Renovated Fiterman Hall.

ERIC Educational Resources Information Center

Ladesich, Jim

2000-01-01

Explores the planning and testing involved in successfully replacing windows in a corporate office building converted into an academic building. Inspection procedures and performance testing are examined. (GR)

Counter tube window and X-ray fluorescence analyzer study

NASA Technical Reports Server (NTRS)

Hertel, R.; Holm, M.

1973-01-01

A study was performed to determine the best design tube window and X-ray fluorescence analyzer for quantitative analysis of Venusian dust and condensates. The principal objective of the project was to develop the best counter tube window geometry for the sensing element of the instrument. This included formulation of a mathematical model of the window and optimization of its parameters. The proposed detector and instrument has several important features. The instrument will perform a near real-time analysis of dust in the Venusian atmosphere, and is capable of measuring dust layers less than 1 micron thick. In addition, wide dynamic measurement range will be provided to compensate for extreme variations in count rates. An integral pulse-height analyzer and memory accumulate data and read out spectra for detail computer analysis on the ground.

Linear topology in amorphous metal oxide electrochromic networks obtained via low-temperature solution processing

NASA Astrophysics Data System (ADS)

Llordés, Anna; Wang, Yang; Fernandez-Martinez, Alejandro; Xiao, Penghao; Lee, Tom; Poulain, Agnieszka; Zandi, Omid; Saez Cabezas, Camila A.; Henkelman, Graeme; Milliron, Delia J.

2016-12-01

Amorphous transition metal oxides are recognized as leading candidates for electrochromic window coatings that can dynamically modulate solar irradiation and improve building energy efficiency. However, their thin films are normally prepared by energy-intensive sputtering techniques or high-temperature solution methods, which increase manufacturing cost and complexity. Here, we report on a room-temperature solution process to fabricate electrochromic films of niobium oxide glass (NbOx) and `nanocrystal-in-glass’ composites (that is, tin-doped indium oxide (ITO) nanocrystals embedded in NbOx glass) via acid-catalysed condensation of polyniobate clusters. A combination of X-ray scattering and spectroscopic characterization with complementary simulations reveals that this strategy leads to a unique one-dimensional chain-like NbOx structure, which significantly enhances the electrochromic performance, compared to a typical three-dimensional NbOx network obtained from conventional high-temperature thermal processing. In addition, we show how self-assembled ITO-in-NbOx composite films can be successfully integrated into high-performance flexible electrochromic devices.

"Sturdy as a house with four windows," the star tracker of the future

NASA Astrophysics Data System (ADS)

Duivenvoorde, Tom; Leijtens, Johan; van der Heide, Erik J.

2017-11-01

Ongoing miniaturization of spacecraft demands the reduction in size of Attitude and Orbit Control Systems (AOCS). Therefore TNO has created a new design of a multi aperture, high performance, and miniaturized star tracker. The innovative design incorporates the latest developments in camera technology, attitude calculation and mechanical design into a system with 5 arc seconds accuracy, making the system usable for many applications. In this paper the results are presented of the system design and analysis, as well as the performance predictions for the Multi Aperture Baffled Star Tracker (MABS). The highly integrated system consists of multiple apertures without the need for external baffles, resulting in major advantages in mass, volume, alignment with the spacecraft and relative aperture stability. In the analysis part of this paper, the thermal and mechanical stability are discussed. In the final part the simulation results will be described that have lead to the predicted accuracy of the star tracker system and a peek into the future of attitude sensors is given.

High performance solutions and data for nZEBs offices located in warm climates.

PubMed

Congedo, Paolo Maria; Baglivo, Cristina; Zacà, Ilaria; D Agostino, Delia

2015-12-01

This data article contains eleven tables supporting the research article entitled: Cost-Optimal Design For Nearly Zero Energy Office Buildings Located In Warm Climates [1]. The data explain the procedure of minimum energy performance requirements presented by the European Directive (EPBD) [2] to establish several variants of energy efficiency measures with the integration of renewable energy sources in order to reach nZEBs (nearly zero energy buildings) by 2020. This files include the application of comparative methodological framework and give the cost-optimal solutions for non-residential building located in Southern Italy. The data describe office sector in which direct the current European policies and investments [3], [4]. In particular, the localization of the building, geometrical features, thermal properties of the envelope and technical systems for HVAC are reported in the first sections. Energy efficiency measures related to orientation, walls, windows, heating, cooling, dhw and RES are given in the second part of the group; this data article provides 256 combinations for a financial and macroeconomic analysis.

Calculated photonic structures for infrared emittance control

NASA Astrophysics Data System (ADS)

Rung, Andreas; Ribbing, Carl G.

2002-06-01

Using an available program package based on the transfer-matrix method, we calculated the photonic band structure for two different structures: a quasi-three-dimensional crystal of square air rods in a high-index matrix and an opal structure of high-index spheres in a matrix of low index, epsilon = 1.5. The high index used is representative of gallium arsenide in the thermal infrared range. The geometric parameters of the rod dimension, sphere radius, and lattice constants were chosen to give total reflectance for normal incidence, i.e., minimum thermal emittance, in either one of the two infrared atmospheric windows. For these four photonic crystals, the bulk reflectance spectra and the wavelength-averaged thermal emittance as a function of crystal thickness were calculated. The results reveal that potentially useful thermal signature suppression is obtained for crystals as thin as 20-50 mum, i.e., comparable with that of a paint layer.

Thermoplastic polyimide NEW-TPI (trademark)

NASA Technical Reports Server (NTRS)

Hou, Tan-Hung; Reddy, Rakasi M.

1990-01-01

Thermal and rheological properties of a commercial thermoplastic polyimide, NEW-TPI (trademark), were characterized. The as-received material possesses initially a transient crystallite form with a bimodal distribution in peak melting temperatures. After the melting of the initial crystallite structure, the sample can be recrystallized by various thermal treatments. A bimodal or single modal melting peak distribution is formed for annealing temperatures below or above 360 C, respectively. The recrystallized crystallinities are all transient in nature. The polymers are unable to be recrystallized after being subjected to elevated temperature annealing above 450 C. The recrystallization mechanism was postulated, and a simple kinetics model was found to describe the behavior rather satisfactory under the conditions of prolonged thermal annealing. Rheological measurements made in the linear viscoelastic range support the evidence observed in the thermal analysis. Furthermore, the measurements sustain the manufacturer's recommended processing window of 400 to 420 C for this material.

Winter risk estimations through infrared cameras an principal component analysis

NASA Astrophysics Data System (ADS)

Marchetti, M.; Dumoulin, J.; Ibos, L.

2012-04-01

Thermal mapping has been implemented since the late eighties to measure road pavement temperature along with some other atmospheric parameters to establish a winter risk describing the susceptibility of road network to ice occurrence. Measurements are done using a vehicle circulating on the road network in various road weather conditions. When the dew point temperature drops below road surface temperature a risk of ice occurs and therefore a loss of grip risk for circulating vehicles. To avoid too much influence of the sun, and to see the thermal behavior of the pavement enhanced, thermal mapping is usually done before dawn during winter time. That is when the energy accumulated by the road during daytime is mainly dissipated (by radiation, by conduction and by convection) and before the road structure starts a new cycle. This analysis is mainly done when a new road network is built, or when some major pavement changes are made, or when modifications in the road surroundings took place that might affect the thermal heat balance. This helps road managers to install sensors to monitor road status on specific locations identified as dangerous, or simply to install specific road signs. Measurements are anyhow time-consuming. Indeed, a whole road network can hardly be analysed at once, and has to be partitioned in stretches that could be done in the open time window to avoid temperature artefacts due to a rising sun. The LRPC Nancy has been using a thermal mapping vehicle with now two infrared cameras. Road events were collected by the operator to help the analysis of the network thermal response. A conventional radiometer with appropriate performances was used as a reference. The objective of the work was to compare results from the radiometer and the cameras. All the atmospheric parameters measured by the different sensors such as air temperature and relative humidity were used as input parameters for the infrared camera when recording thermal images. Road thermal heterogeneities were clearly identified, while usually missed by a conventional radiometer. In the case presented here, the two lanes of the road could be properly observed. Promising perspectives appeared to increase the measurement rate. Furthermore, to cope with the climatic constraints of the winter measurements as to build a dynamic winter risk, a multivariate data analysis approach was implemented. Principal component analysis was performed and enabled to set up of dynamic thermal signature with a great agreement between statistical results and field measurements.

Effect of the time window on the heat-conduction information filtering model

NASA Astrophysics Data System (ADS)

Guo, Qiang; Song, Wen-Jun; Hou, Lei; Zhang, Yi-Lu; Liu, Jian-Guo

2014-05-01

Recommendation systems have been proposed to filter out the potential tastes and preferences of the normal users online, however, the physics of the time window effect on the performance is missing, which is critical for saving the memory and decreasing the computation complexity. In this paper, by gradually expanding the time window, we investigate the impact of the time window on the heat-conduction information filtering model with ten similarity measures. The experimental results on the benchmark dataset Netflix indicate that by only using approximately 11.11% recent rating records, the accuracy could be improved by an average of 33.16% and the diversity could be improved by 30.62%. In addition, the recommendation performance on the dataset MovieLens could be preserved by only considering approximately 10.91% recent records. Under the circumstance of improving the recommendation performance, our discoveries possess significant practical value by largely reducing the computational time and shortening the data storage space.

Theoretical and experimental investigation on magneto-hydrodynamics of plasma window

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, S. Z.; Zhu, K., E-mail: zhukun@pku.edu.cn; Huang, S.

2016-01-15

As a new device, plasma window has been designed to use plasma discharge to separate atmosphere from vacuum with high difference of pressure. It has many excellent properties, being able to be used as available passage for ion beam with negligible energy loss, also impervious to radiation damage and thermal damage. Normally beam focusing by accelerators is not that easy to achieve within channel of small cross section. 10 mm diameter plasma window's experimental realization could contribute to its further application in accelerator system. In this paper, 10 mm diameter 60 mm long plasma window has first been designed and managed to generatemore » arc discharge with argon gas experimentally. The result proves that it has the ability to separate at least 28.8 kPa (not the upper limit) from 360 Pa with 50 A direct current and 2.5 kW power supplied. Current increase leads to linear inlet pressure increase obviously, while it has less impact on outlet pressure and voltage, coming to the conclusion that the higher current of plasma discharge, the larger pressure difference it creates. Theoretical analysis of 10 mm diameter plasma window in axis symmetrical configuration using argon also has been provided, in which a numerical 2D FLUENT-based magneto-hydrodynamic simulation model is settled. It has a good agreement with experimental result on voltage and mass flow rate when inlet pressure is increased.« less

Effect of Boron Addition on the Thermal, Degradation, and Cytocompatibility Properties of Phosphate-Based Glasses

PubMed Central

Hasan, Muhammad S.; Parsons, Andrew J.; Furniss, David; Scotchford, Colin A.; Ahmed, Ifty; Rudd, Chris D.

2013-01-01

In this study eight different phosphate-based glass compositions were prepared by melt-quenching: four in the (P2O5)45-(CaO)16-(Na2O)15-x -(MgO)24-(B2O3)x system and four in the system (P2O5)50-(CaO)16-(Na2O)10-x-(MgO)24-(B2O3)x, where x = 0,1, 5 and 10 mol%. The effect of B2O3 addition on the thermal properties, density, molar volume, dissolution rates, and cytocompatibility were studied for both glass systems. Addition of B2O3 increased the glass transition (T g), crystallisation (T c), melting (T m), Liquidus (T L) and dilatometric softening (T d) temperature and molar volume (V m). The thermal expansion coefficient (α) and density (ρ) were seen to decrease. An assessment of the thermal stability of the glasses was made in terms of their processing window (crystallisation onset, T c,ons minus glass transition temperature, T g), and an increase in the processing window was observed with increasing B2O3 content. Degradation studies of the glasses revealed that the rates decreased with increasing B2O3 content and a decrease in degradation rates was also observed as the P2O5 content reduced from 50 to 45 mol%. MG63 osteoblast-like cells cultured in direct contact with the glass samples for 14 days revealed comparative data to the positive control for the cell metabolic activity, proliferation, ALP activity, and morphology for glasses containing up to 5 mol% of B2O3. PMID:23991425

LIFETIME AND SPECTRAL EVOLUTION OF A MAGMA OCEAN WITH A STEAM ATMOSPHERE: ITS DETECTABILITY BY FUTURE DIRECT IMAGING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamano, Keiko; Kawahara, Hajime; Abe, Yutaka

2015-06-20

We present the thermal evolution and emergent spectra of solidifying terrestrial planets along with the formation of steam atmospheres. The lifetime of a magma ocean and its spectra through a steam atmosphere depends on the orbital distance of the planet from the host star. For a Type I planet, which is formed beyond a certain critical distance from the host star, the thermal emission declines on a timescale shorter than approximately 10{sup 6} years. Therefore, young stars should be targets when searching for molten planets in this orbital region. In contrast, a Type II planet, which is formed inside themore » critical distance, will emit significant thermal radiation from near-infrared atmospheric windows during the entire lifetime of the magma ocean. The K{sub s} and L bands will be favorable for future direct imaging because the planet-to-star contrasts of these bands are higher than approximately 10{sup −7}–10{sup −8}. Our model predicts that, in the Type II orbital region, molten planets would be present over the main sequence of the G-type host star if the initial bulk content of water exceeds approximately 1 wt%. In visible atmospheric windows, the contrasts of the thermal emission drop below 10{sup −10} in less than 10{sup 5} years, whereas those of the reflected light remain 10{sup −10} for both types of planets. Since the contrast level is comparable to those of reflected light from Earth-sized planets in the habitable zone, the visible reflected light from molten planets also provides a promising target for direct imaging with future ground- and space-based telescopes.« less

Image-guided adaptive gating of lung cancer radiotherapy: a computer simulation study

NASA Astrophysics Data System (ADS)

Aristophanous, Michalis; Rottmann, Joerg; Park, Sang-June; Nishioka, Seiko; Shirato, Hiroki; Berbeco, Ross I.

2010-08-01

The purpose of this study is to investigate the effect that image-guided adaptation of the gating window during treatment could have on the residual tumor motion, by simulating different gated radiotherapy techniques. There are three separate components of this simulation: (1) the 'Hokkaido Data', which are previously measured 3D data of lung tumor motion tracks and the corresponding 1D respiratory signals obtained during the entire ungated radiotherapy treatments of eight patients, (2) the respiratory gating protocol at our institution and the imaging performed under that protocol and (3) the actual simulation in which the Hokkaido Data are used to select tumor position information that could have been collected based on the imaging performed under our gating protocol. We simulated treatments with a fixed gating window and a gating window that is updated during treatment. The patient data were divided into different fractions, each with continuous acquisitions longer than 2 min. In accordance to the imaging performed under our gating protocol, we assume that we have tumor position information for the first 15 s of treatment, obtained from kV fluoroscopy, and for the rest of the fractions the tumor position is only available during the beam-on time from MV imaging. The gating window was set according to the information obtained from the first 15 s such that the residual motion was less than 3 mm. For the fixed gating window technique the gate remained the same for the entire treatment, while for the adaptive technique the range of the tumor motion during beam-on time was measured and used to adapt the gating window to keep the residual motion below 3 mm. The algorithm used to adapt the gating window is described. The residual tumor motion inside the gating window was reduced on average by 24% for the patients with regular breathing patterns and the difference was statistically significant (p-value = 0.01). The magnitude of the residual tumor motion depended on the regularity of the breathing pattern suggesting that image-guided adaptive gating should be combined with breath coaching. The adaptive gating window technique was able to track the exhale position of the breathing cycle quite successfully. Out of a total of 53 fractions the duty cycle was greater than 20% for 42 fractions for the fixed gating window technique and for 39 fractions for the adaptive gating window technique. The results of this study suggest that real-time updating of the gating window can result in reliably low residual tumor motion and therefore can facilitate safe margin reduction.

Flexible Dielectric Nanocomposites with Ultrawide Zero-Temperature Coefficient Windows for Electrical Energy Storage and Conversion under Extreme Conditions.

PubMed

Shehzad, Khurram; Xu, Yang; Gao, Chao; Li, Hanying; Dang, Zhi-Min; Hasan, Tawfique; Luo, Jack; Duan, Xiangfeng

2017-03-01

Polymer dielectrics offer key advantages over their ceramic counterparts such as flexibility, scalability, low cost, and high breakdown voltages. However, a major drawback that limits more widespread application of polymer dielectrics is their temperature-dependent dielectric properties. Achieving dielectric constants with low/zero-temperature coefficient (L/0TC) over a broad temperature range is essential for applications in diverse technologies. Here, we report a hybrid filler strategy to produce polymer composites with an ultrawide L/0TC window of dielectric constant, as well as a significantly enhanced dielectric value, maximum energy storage density, thermal conductivity, and stability. By creating a series of percolative polymer composites, we demonstrated hybrid carbon filler based composites can exhibit a zero-temperature coefficient window of 200 °C (from -50 to 150 °C), the widest 0TC window for all polymer composite dielectrics reported to date. We further show the electric and dielectric temperature coefficient of the composites is highly stable against stretching and bending, even under AC electric field with frequency up to 1 MHz. We envision that our method will push the functional limits of polymer dielectrics for flexible electronics in extreme conditions such as in hybrid vehicles, aerospace, power electronics, and oil/gas exploration.

Selective-area growth of GaN nanowires on SiO{sub 2}-masked Si (111) substrates by molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruse, J. E.; Doundoulakis, G.; Institute of Electronic Structure and Laser, Foundation for Research and Technology–Hellas, N. Plastira 100, 70013 Heraklion

2016-06-14

We analyze a method to selectively grow straight, vertical gallium nitride nanowires by plasma-assisted molecular beam epitaxy (MBE) at sites specified by a silicon oxide mask, which is thermally grown on silicon (111) substrates and patterned by electron-beam lithography and reactive-ion etching. The investigated method requires only one single molecular beam epitaxy MBE growth process, i.e., the SiO{sub 2} mask is formed on silicon instead of on a previously grown GaN or AlN buffer layer. We present a systematic and analytical study involving various mask patterns, characterization by scanning electron microscopy, transmission electron microscopy, and photoluminescence spectroscopy, as well asmore » numerical simulations, to evaluate how the dimensions (window diameter and spacing) of the mask affect the distribution of the nanowires, their morphology, and alignment, as well as their photonic properties. Capabilities and limitations for this method of selective-area growth of nanowires have been identified. A window diameter less than 50 nm and a window spacing larger than 500 nm can provide single nanowire nucleation in nearly all mask windows. The results are consistent with a Ga diffusion length on the silicon dioxide surface in the order of approximately 1 μm.« less

Novel Cranial Implants of Yttria-Stabilized Zirconia as Acoustic Windows for Ultrasonic Brain Therapy.

PubMed

Gutierrez, Mario I; Penilla, Elias H; Leija, Lorenzo; Vera, Arturo; Garay, Javier E; Aguilar, Guillermo

2017-11-01

Therapeutic ultrasound can induce changes in tissues by means of thermal and nonthermal effects. It is proposed for treatment of some brain pathologies such as Alzheimer's, Parkinson's, Huntington's diseases, and cancer. However, cranium highly absorbs ultrasound reducing transmission efficiency. There are clinical applications of transcranial focused ultrasound and implantable ultrasound transducers proposed to address this problem. In this paper, biocompatible materials are proposed for replacing part of the cranium (cranial implants) based on low porosity polycrystalline 8 mol% yttria-stabilized-zirconia (8YSZ) ceramics as acoustic windows for brain therapy. In order to assess the viability of 8YSZ implants to effectively transmit ultrasound, various 8YSZ ceramics with different porosity are tested; their acoustic properties are measured; and the results are validated using finite element models simulating wave propagation to brain tissue through 8YSZ windows. The ultrasound attenuation is found to be linearly dependent on ceramics' porosity. Results for the nearly pore-free case indicate that 8YSZ is highly effective in transmitting ultrasound, with overall maximum transmission efficiency of ≈81%, compared to near total absorption of cranial bone. These results suggest that 8YSZ polycrystals could be suitable acoustic windows for ultrasound brain therapy at 1 MHz. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Air transparent soundproof window

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sang-Hoon, E-mail: shkim@mmu.ac.kr; Lee, Seong-Hyun

2014-11-15

A soundproof window or wall which is transparent to airflow is presented. The design is based on two wave theories: the theory of diffraction and the theory of acoustic metamaterials. It consists of a three-dimensional array of strong diffraction-type resonators with many holes centered on each individual resonator. The negative effective bulk modulus of the resonators produces evanescent wave, and at the same time the air holes with subwavelength diameter existed on the surfaces of the window for macroscopic air ventilation. The acoustic performance levels of two soundproof windows with air holes of 20mm and 50mm diameters were measured. Themore » sound level was reduced by about 30 - 35dB in the frequency range of 400 - 5,000Hz with the 20mm window, and by about 20 - 35dB in the frequency range of 700 - 2,200Hz with the 50mm window. Multi stop-band was created by the multi-layers of the window. The attenuation length or the thickness of the window was limited by background noise. The effectiveness of the soundproof window with airflow was demonstrated by a real installation.« less

Exterior Space Retrofitting Planning with Possible Effect on Building Thermal Characteristics

NASA Astrophysics Data System (ADS)

Berezin, D. V.

2017-11-01

The problems of mass housing which was serially designed and produced throughout Eastern European and former Soviet cities in the middle of the 20th century, in regard to its solar-related thermal conditions improvement by refurbishing are raised in the paper. The impact of functional zones’ dimensions (based on the dwellers’ domestic actions) on shading properties of balconies and loggias is analyzed. As a result, the ratios of exterior space area (as a complex of shading elements related to balconies/loggias) to the windows area that reflect the frequency of the indoor air overheating are determined which can serve as a simple evaluative thermal comfort-related tool for projected and existing buildings under a real solar activity between the geographic latitudes 55° - 56°.

Spectral reflectance and emissivity features of broad leaf plants: Prospects for remote sensing in the thermal infrared (8.0-14.0 μm)

USGS Publications Warehouse

Ribeiro da Luz, Beatriz; Crowley, James K.

2007-01-01

In contrast to visible and short-wave infrared data, thermal infrared spectra of broad leaf plants show considerable spectral diversity, suggesting that such data eventually could be utilized to map vegetation composition. However, remotely measuring the subtle emissivity features of leaves still presents major challenges. To be successful, sensors operating in the 8–14 μm atmospheric window must have high signal-to-noise and a small enough instantaneous field of view to allow measurements of only a few leaf surfaces. Methods for atmospheric compensation, temperature–emissivity separation, and spectral feature analysis also will need to be refined to allow the recognition, and perhaps, exploitation of leaf thermal infrared spectral properties.

Transparent and Flexible Large-scale Graphene-based Heater

NASA Astrophysics Data System (ADS)

Kang, Junmo; Lee, Changgu; Kim, Young-Jin; Choi, Jae-Boong; Hong, Byung Hee

2011-03-01

We report the application of transparent and flexible heater with high optical transmittance and low sheet resistance using graphene films, showing outstanding thermal and electrical properties. The large-scale graphene films were grown on Cu foil by chemical vapor deposition methods, and transferred to transparent substrates by multiple stacking. The wet chemical doping process enhanced the electrical properties, showing a sheet resistance as low as 35 ohm/sq with 88.5 % transmittance. The temperature response usually depends on the dimension and the sheet resistance of the graphene-based heater. We show that a 4x4 cm2 heater can reach 80& circ; C within 40 seconds and large-scale (9x9 cm2) heater shows uniformly heating performance, which was measured using thermocouple and infra-red camera. These heaters would be very useful for defogging systems and smart windows.

Multi-Window Controllers for Autonomous Space Systems

NASA Technical Reports Server (NTRS)

Lurie, B, J.; Hadaegh, F. Y.

1997-01-01

Multi-window controllers select between elementary linear controllers using nonlinear windows based on the amplitude and frequency content of the feedback error. The controllers are relatively simple to implement and perform much better than linear controllers. The commanders for such controllers only order the destination point and are freed from generating the command time-profiles. The robotic missions rely heavily on the tasks of acquisition and tracking. For autonomous and optimal control of the spacecraft, the control bandwidth must be larger while the feedback can (and, therefore, must) be reduced.. Combining linear compensators via multi-window nonlinear summer guarantees minimum phase character of the combined transfer function. It is shown that the solution may require using several parallel branches and windows. Several examples of multi-window nonlinear controller applications are presented.

3D coupled heat and mass transfer processes at the scale of sedimentary basisn

NASA Astrophysics Data System (ADS)

Cacace, M.; Scheck-Wenderoth, M.; Kaiser, B. O.

2014-12-01

We use coupled 3D simulations of fluid, heat, and transport based on a 3D structural model of a complex geological setting, the Northeast German Basin (NEGB). The geological structure of the NEGB is characterized by a relatively thick layer of Permian Zechstein salt, structured in differnet diapirs (up to 5000 m thick) and pillows locally reaching nearly the surface. Salt is thermally more conductive than other sediments, hydraulically impervious but highly solvable. Thus salt structures have first order influence on the temperature distribution, the deep flow regime and the salinity of groundawater bearing aquifers. In addition, the post-Permian sedimentary sequence is vertically subdivided into several aquifers and aquitards. The shallow Quaternary to late Tertiary freshwater aquifer is separated from the underlying Mesozoic saline aquifers by an embedded Tertiary clay enriched aquitard (Rupelian Aquitard). An important feature of this aquitard is that hydraulic connections between the upper and lower aquifers exist in areas where the Rupelian Aquitard is missing (hydrogeological windows). By means of 3D numerical simulations we explore the role of heat conduction, pressure, and density driven groundwater flow as well as fluid viscosity-related and salinity-dependent effects on the resulting flow and temperature fields. Our results suggest that the regional temperature distribution within the basin results from interactions between regional pressure forces and thermal diffusion locally enhanced by thermal conductivity contrasts between the different sedimentary rocks with the highly conductive salt. Buoyancy forces triggered by temperature-dependent fluid density variations affect only locally the internal thermal configuration. Locations, geometry, and wavelengths of convective thermal anomalies are mainly controlled by the permeability field and thickness values of the respective geological layers. Numerical results from 3D thermo-haline numerical simulations suggest that hydrogeological windows act as preferential domains of hydraulic interconnectivity between the different aquifers at depth, and enable vigorous heat and mass transport which causes a mixing of warm and saline groundwater with cold and less saline groundwater within both aquifers.

Transition Metal Switchable Mirror

ScienceCinema

None

2017-12-29

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

Orion Hatch Window Testing

NASA Image and Video Library

2018-04-09

Mark Nurge, Ph.D., a physicist in the Applied Physics Lab with the Exploration Research and Technology Programs at NASA's Kennedy Space Center in Florida, looks at data during the first optical quality test on a full window stack that is ready for installation in the docking hatch of NASA's Orion spacecraft. The data from the tests will help improve the requirements for manufacturing tolerances on Orion's windows and verify how the window should perform in space. Orion is being prepared for its first integrated uncrewed flight atop NASA's Space Launch System rocket on Exploration Mission-1.

Transition Metal Switchable Mirror

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2009-08-21

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

A Pilot Demonstration of Electrochromic and Thermochromic Windows in the Denver Federal Center, Building 41, Denver, Colorado

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Eleanor S.; Fernandes, Luis L.; Goudey, Chad Howdy

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 airconditioning (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 projectmore » 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.« less

Heat Rejection from a Variable Conductance Heat Pipe Radiator Panel

NASA Technical Reports Server (NTRS)

Jaworske, D. A.; Gibson, M. A.; Hervol, D. S.

2012-01-01

A titanium-water heat pipe radiator having an innovative proprietary evaporator configuration was evaluated in a large vacuum chamber equipped with liquid nitrogen cooled cold walls. The radiator was manufactured by Advanced Cooling Technologies, Inc. (ACT), Lancaster, PA, and delivered as part of a Small Business Innovative Research effort. The radiator panel consisted of five titanium-water heat pipes operating as thermosyphons, sandwiched between two polymer matrix composite face sheets. The five variable conductance heat pipes were purposely charged with a small amount of non-condensable gas to control heat flow through the condenser. Heat rejection was evaluated over a wide range of inlet water temperature and flow conditions, and heat rejection was calculated in real-time utilizing a data acquisition system programmed with the Stefan-Boltzmann equation. Thermography through an infra-red transparent window identified heat flow across the panel. Under nominal operation, a maximum heat rejection value of over 2200 Watts was identified. The thermal vacuum evaluation of heat rejection provided critical information on understanding the radiator s performance, and in steady state and transient scenarios provided useful information for validating current thermal models in support of the Fission Power Systems Project.

Ground-based remote sensing of thin clouds in the Arctic

NASA Astrophysics Data System (ADS)

Garrett, T. J.; Zhao, C.

2013-05-01

This paper describes a method for using interferometer measurements of downwelling thermal radiation to retrieve the properties of single-layer clouds. Cloud phase is determined from ratios of thermal emission in three "micro-windows" at 862.5 cm-1, 935.8 cm-1, and 988.4 cm-1 where absorption by water vapour is particularly small. Cloud microphysical and optical properties are retrieved from thermal emission in the first two of these micro-windows, constrained by the transmission through clouds of primarily stratospheric ozone emission at 1040 cm-1. Assuming a cloud does not approximate a blackbody, the estimated 95% confidence retrieval errors in effective radius re, visible optical depth τ, number concentration N, and water path WP are, respectively, 10%, 20%, 38% (55% for ice crystals), and 16%. Applied to data from the Atmospheric Radiation Measurement programme (ARM) North Slope of Alaska - Adjacent Arctic Ocean (NSA-AAO) site near Barrow, Alaska, retrievals show general agreement with both ground-based microwave radiometer measurements of liquid water path and a method that uses combined shortwave and microwave measurements to retrieve re, τ and N. Compared to other retrieval methods, advantages of this technique include its ability to characterise thin clouds year round, that water vapour is not a primary source of retrieval error, and that the retrievals of microphysical properties are only weakly sensitive to retrieved cloud phase. The primary limitation is the inapplicability to thicker clouds that radiate as blackbodies and that it relies on a fairly comprehensive suite of ground based measurements.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandes, P. A.; Lynch, K. A.

Here, we define the observational parameter regime necessary for observing low-altitude ionospheric origins of high-latitude ion upflow/outflow. We present measurement challenges and identify a new analysis technique which mitigates these impediments. To probe the initiation of auroral ion upflow, it is necessary to examine the thermal ion population at 200-350 km, where typical thermal energies are tenths of eV. Interpretation of the thermal ion distribution function measurement requires removal of payload sheath and ram effects. We use a 3-D Maxwellian model to quantify how observed ionospheric parameters such as density, temperature, and flows affect in situ measurements of the thermalmore » ion distribution function. We define the viable acceptance window of a typical top-hat electrostatic analyzer in this regime and show that the instrument's energy resolution prohibits it from directly observing the shape of the particle spectra. To extract detailed information about measured particle population, we define two intermediate parameters from the measured distribution function, then use a Maxwellian model to replicate possible measured parameters for comparison to the data. Liouville's theorem and the thin-sheath approximation allow us to couple the measured and modeled intermediate parameters such that measurements inside the sheath provide information about plasma outside the sheath. We apply this technique to sounding rocket data to show that careful windowing of the data and Maxwellian models allows for extraction of the best choice of geophysical parameters. More widespread use of this analysis technique will help our community expand its observational database of the seed regions of ionospheric outflows.« less

A Simulation Study of Paced TCP

NASA Technical Reports Server (NTRS)

Kulik, Joanna; Coulter, Robert; Rockwell, Dennis; Partridge, Craig

2000-01-01

In this paper, we study the performance of paced TCP, a modified version of TCP designed especially for high delay- bandwidth networks. In typical networks, TCP optimizes its send-rate by transmitting increasingly large bursts, or windows, of packets, one burst per round-trip time, until it reaches a maximum window-size, which corresponds to the full capacity of the network. In a network with a high delay-bandwidth product, however, Transmission Control Protocol's (TCPs) maximum window-size may be larger than the queue size of the intermediate routers, and routers will begin to drop packets as soon as the windows become too large for the router queues. The TCP sender then concludes that the bottleneck capacity of the network has been reached, and it limits its send-rate accordingly. Partridge proposed paced TCP as a means of solving the problem of queueing bottlenecks. A sender using paced TCP would release packets in multiple, small bursts during a round-trip time in which ordinary TCP would release a single, large burst of packets. This approach allows the sender to increase its send-rate to the maximum window size without encountering queueing bottlenecks. This paper describes the performance of paced TCP in a simulated network and discusses implementation details that can affect the performance of paced TCP.

VEM on VERITAS - Retrieval of global infrared surface emissivity maps of Venus and expectable retrieval uncertainties

NASA Astrophysics Data System (ADS)

Kappel, David; Arnold, Gabriele; Haus, Rainer; Helbert, Jörn; Smrekar, Suzanne; Hensley, Scott

2016-04-01

Even though Venus is in many respects the most Earth-like planet we know today, its surface composition and geology are not well understood yet. The major obstacle is the extremely dense, hot, and opaque atmosphere that complicates both in situ measurements and infrared remote sensing, the wavelength range of the latter often being the range of choice due to its coverage of many spectral properties diagnostic to the surface material's composition and texture. Thermal emissions of the hot surface depend on surface temperature and on spectral surface emissivity. As this emitted radiation wells upward, it is strongly attenuated through absorption and multiple scattering by the gaseous and particulate components of the dense atmosphere, and it is superimposed by thermal atmospheric emissions. While surface information this way carried to space is completely lost in the scattered sunlight on the dayside, a few narrow atmospheric transparency windows around 1 μm allow the sounding of the surface with nightside measurements. The successfully completed VEX ('Venus Express') mission, although not dedicated to surface science, enabled a first glimpse at much of the southern hemisphere's surface through the nightside spectral transparency windows covered by VIRTIS-M-IR ('Visible and InfraRed Thermal Imaging Spectrometer, Mapping channel in the IR', 1.0-5.1 μm). Two complementary approaches, a fast semi-empiric technique on the one hand, and a more fundamental but resource-intensive method based on a fully regularized Bayesian multi-spectrum retrieval algorithm in combination with a detailed radiative transfer simulation program on the other hand, were both successfully applied to derive surface emissivity data maps. Both methods suffered from lack of spatial coverage and a small SNR as well as from surface topography maps not sufficiently accurate for the definition of suitable boundary conditions for surface emissivity retrieval. The recently proposed VERITAS mission ('Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy') comprises two instruments, VEM ('Venus Emissivity Mapper') and VISAR ('Venus Interferometric Synthetic Aperture Radar'). This mission will yield a vastly improved data basis with respect to both high SNR Venus nightside radiance measurements at all transparency windows around 1 μm as well as topography maps. The new data will enable the derivation of much more complete and reliable global surface emissivity maps that are required to answer fundamental geologic questions. Here, we discuss the selection of the wavelength ranges covered by the spectral filters of VEM as well as improved estimates of expectable emissivity retrieval errors based on this selection. For this purpose, the locations of the relevant spectral transparency windows are studied with detailed line-by-line radiative transfer simulations in dependence on different spectral line databases. Recent work on VIRTIS-M-IR/VEX measurements indicated the presence of interferences due to ever-varying atmospheric parameters that cannot be derived from radiance measurements with limited spectral information content to be a dominant source of surface emissivity retrieval errors. This work is carried over to the configuration of VEM, and the retrieval pipeline is optimized to minimize such errors. A portion of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

Casing window milling with abrasive fluid jet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vestavik, O.M.; Fidtje, T.H.; Faure, A.M.

1995-12-31

Methods for through tubing re-entry drilling of multilateral wells has a large potential for increasing hydrocarbon production and total recovery. One of the bottle-necks of this technology is initiation of the side-track by milling a window in the casing downhole. A new approach to this problem has been investigated in a joint industry project. An experimental set-up has been built for milling a 4 inch window in a 7 inch steel casing at surface in the laboratory. A specially designed bit developed at RIF using abrasive jet cutting technology has been used for the window milling. The bit has anmore » abrasive jet beam which is always directed in the desired side-track direction, even if the bit is rotating uniformly. The bit performs the milling with a combined mechanical and hydraulic jet action. The method has been successfully demonstrated. The experiments has shown that the window milling can be performed with very low WOB and torque, and that only small side forces are required to perform the operation. Casing milling has been performed without a whipstock, a cement plug has been the only support for the tool. The tests indicate that milling operations can be performed more efficiently with less time and costs than what is required with conventional techniques. However, the method still needs some development of the downhole motor for coiled tubing applications. The method can be used both for milling and drilling giving the advantage of improved rate of penetration, improved bit life and increased horizontal reach. The method is planned to be demonstrated downhole in the near future.« less

Impacts of Climate Variability and Change on (Marine) Animals: Physiological Underpinnings and Evolutionary Consequences.

PubMed

Pörtner, Hans O; Gutt, Julian

2016-07-01

Understanding thermal ranges and limits of organisms becomes important in light of climate change and observed effects on ecosystems as reported by the IPCC (2014). Evolutionary adaptation to temperature is presently unable to keep animals and other organisms in place; if they can these rather follow the moving isotherms. These effects of climate change on aquatic and terrestrial ecosystems have brought into focus the mechanisms by which temperature and its oscillations shape the biogeography and survival of species. For animals, the integrative concept of oxygen and capacity limited thermal tolerance (OCLTT) has successfully characterized the sublethal limits to performance and the consequences of such limits for ecosystems. Recent models illustrate how routine energy demand defines the realized niche. Steady state temperature-dependent performance profiles thus trace the thermal window and indicate a key role for aerobic metabolism, and the resulting budget of available energy (power), in defining performance under routine conditions, from growth to exercise and reproduction. Differences in the performance and productivity of marine species across latitudes relate to changes in mitochondrial density, capacity, and other features of cellular design. Comparative studies indicate how and why such mechanisms underpinning OCLTT may have developed on evolutionary timescales in different climatic zones and contributed to shaping the functional characteristics and species richness of the respective fauna. A cause-and-effect understanding emerges from considering the relationships between fluctuations in body temperature, cellular design, and performance. Such principles may also have been involved in shaping the functional characteristics of survivors in mass extinction events during earth's history; furthermore, they may provide access to understanding the evolution of endothermy in mammals and birds. Accordingly, an understanding is emerging how climate changes and variability throughout earth's history have influenced animal evolution and co-defined their success or failure from a bio-energetic point of view. Deepening such understanding may further reduce uncertainty about projected impacts of anthropogenic climate variability and change on the distribution, productivity and last not least, survival of aquatic and terrestrial species. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Optical Property Requirements for Glasses, Ceramics and Plastics in Spacecraft Window Systems

NASA Technical Reports Server (NTRS)

Estes, Lynda

2011-01-01

This is a preliminary draft of a standard published by the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) that is intended to provide uniform window optical design requirements in support of the development of human-rated spaceflight hardware. The material covered in this standard is based on data from extensive testing by the Advanced Sensing and Optical Measurement Branch at NASA Langley Research Center, and compiled into requirements format by the NASA JSC Structural Engineering Division. At the time of this initial document release, a broader technical community has not reviewed this standard. The technical content of this standard is primarily based on the Constellation Program Orion Crew Exploration Vehicle Window Optical Properties Requirements, CxP 72407, Baseline. Unlike other optical requirements documents available for human rated spacecraft, this document includes requirements that ensure functionality for windows that contain glass/ceramic and/or plastic window substrate materials. These requirements were derived by measuring the optical properties of fused silica and aluminosilicate glass window assemblies and ensuring that the performance of any window assembly that includes a plastic pane or panes will meet the performance level of the all-glass assemblies. The resulting requirements are based upon the performance and parameter metrology testing of a variety of materials, including glass, transparent ceramics, acrylics, and polycarbonates. In general, these requirements are minimum specifications for each optical parameter in order to achieve the function specified for each functional category, A through D. Because acrylic materials perform at a higher level than polycarbonates in the optics regime, and CxP/Orion is planning to use acrylic in the Orion spacecraft, these requirements are based heavily on metrology from that material. As a result, two of the current Category D requirements for plastics are cited in such a way that will result in the screening out of polycarbonates. It is acknowledged that many polycarbonates can perform the functions of Category D, such as piloting and imagery with lens with apertures up to 25mm, without performance issues. Therefore, this forward warns users that certain requirements, such as birefringence and wavefront, for Category D plastics need to be revised to allow those polycarbonates that perform adequately in Category D to be accepted, while at the same time, screen out those materials that do not perform up to par. At the time of document release, the requirements in question have been identified by a TBD beside the proposed requirement criteria (which is based upon acrylic performance). Vehicles that are designed with acrylic materials for windowpanes are encouraged to use the values presented in this document for all requirements, in order to ensure adequate optical performance.

Thermal conductivity in large - J two-dimensional antiferromagnets: Role of phonon scattering

DOE PAGES

Chernyshev, A. L.; Brenig, Wolfram

2015-08-05

Different types of relaxation processes for magnon heat current are discussed, with a particular focus on coupling to three-dimensional phonons. There is thermal conductivity by these in-plane magnetic excitations using two distinct techniques: Boltzmann formalism within the relaxation-time approximation and memory-function approach. Also considered are the scattering of magnons by both acoustic and optical branches of phonons. We demonstrate an accord between the two methods, regarding the asymptotic behavior of the effective relaxation rates. It is strongly suggested that scattering from optical or zone-boundary phonons is important for magnon heat current relaxation in a high-temperature window of ΘD≲T<< J.

Intrinsically High Thermoelectric Performance in AgInSe2 n-Type Diamond-Like Compounds.

PubMed

Qiu, Pengfei; Qin, Yuting; Zhang, Qihao; Li, Ruoxi; Yang, Jiong; Song, Qingfeng; Tang, Yunshan; Bai, Shengqiang; Shi, Xun; Chen, Lidong

2018-03-01

Diamond-like compounds are a promising class of thermoelectric materials, very suitable for real applications. However, almost all high-performance diamond-like thermoelectric materials are p-type semiconductors. The lack of high-performance n-type diamond-like thermoelectric materials greatly restricts the fabrication of diamond-like material-based modules and their real applications. In this work, it is revealed that n-type AgInSe 2 diamond-like compound has intrinsically high thermoelectric performance with a figure of merit ( zT ) of 1.1 at 900 K, comparable to the best p-type diamond-like thermoelectric materials reported before. Such high zT is mainly due to the ultralow lattice thermal conductivity, which is fundamentally limited by the low-frequency Ag-Se "cluster vibrations," as confirmed by ab initio lattice dynamic calculations. Doping Cd at Ag sites significantly improves the thermoelectric performance in the low and medium temperature ranges. By using such high-performance n-type AgInSe 2 -based compounds, the diamond-like thermoelectric module has been fabricated for the first time. An output power of 0.06 W under a temperature difference of 520 K between the two ends of the module is obtained. This work opens a new window for the applications using the diamond-like thermoelectric materials.

Fabrication of MgF2 and LiF windows for the Hubble Space Telescope Imaging Spectrograph

NASA Technical Reports Server (NTRS)

Gormley, Daphne; Bottema, Murk; Darnell, Barbara; Fowler, Walter; Medenica, Walter

1988-01-01

Two prototype test windows (MgF2 and LiF) to be used on the 75-mm UV MAMA detector tubes for the Hubble Space Telescope Imaging Spectrograph are described. The spatial and optical constraints of this instrument dictate that the thickness of the window materials be no greater than 2-3 mm to achieve a minimum 50-percent transmission at hydrogen Lyman alpha (121.6 nm), and that the window must be domed to minimize optical aberrations and provide structural strength. The detector window has an input diameter of about 100 mm with a radius-of-curvature of 70 mm. The manufacturing processes involved in the fabrication of these windows is discussed, as well as test programs (optical and structural) to be performed at Goddard Space Flight Center.

Generalized Split-Window Algorithm for Estimate of Land Surface Temperature from Chinese Geostationary FengYun Meteorological Satellite (FY-2C) Data

PubMed Central

Tang, Bohui; Bi, Yuyun; Li, Zhao-Liang; Xia, Jun

2008-01-01

On the basis of the radiative transfer theory, this paper addressed the estimate of Land Surface Temperature (LST) from the Chinese first operational geostationary meteorological satellite-FengYun-2C (FY-2C) data in two thermal infrared channels (IR1, 10.3-11.3 μm and IR2, 11.5-12.5 μm), using the Generalized Split-Window (GSW) algorithm proposed by Wan and Dozier (1996). The coefficients in the GSW algorithm corresponding to a series of overlapping ranging of the mean emissivity, the atmospheric Water Vapor Content (WVC), and the LST were derived using a statistical regression method from the numerical values simulated with an accurate atmospheric radiative transfer model MODTRAN 4 over a wide range of atmospheric and surface conditions. The simulation analysis showed that the LST could be estimated by the GSW algorithm with the Root Mean Square Error (RMSE) less than 1 K for the sub-ranges with the Viewing Zenith Angle (VZA) less than 30° or for the sub-rangs with VZA less than 60° and the atmospheric WVC less than 3.5 g/cm2 provided that the Land Surface Emissivities (LSEs) are known. In order to determine the range for the optimum coefficients of the GSW algorithm, the LSEs could be derived from the data in MODIS channels 31 and 32 provided by MODIS/Terra LST product MOD11B1, or be estimated either according to the land surface classification or using the method proposed by Jiang et al. (2006); and the WVC could be obtained from MODIS total precipitable water product MOD05, or be retrieved using Li et al.' method (2003). The sensitivity and error analyses in term of the uncertainty of the LSE and WVC as well as the instrumental noise were performed. In addition, in order to compare the different formulations of the split-window algorithms, several recently proposed split-window algorithms were used to estimate the LST with the same simulated FY-2C data. The result of the intercomparsion showed that most of the algorithms give comparable results. PMID:27879744

Generalized Split-Window Algorithm for Estimate of Land Surface Temperature from Chinese Geostationary FengYun Meteorological Satellite (FY-2C) Data.

PubMed

Tang, Bohui; Bi, Yuyun; Li, Zhao-Liang; Xia, Jun

2008-02-14

On the basis of the radiative transfer theory, this paper addressed the estimate ofLand Surface Temperature (LST) from the Chinese first operational geostationarymeteorological satellite-FengYun-2C (FY-2C) data in two thermal infrared channels (IR1,10.3-11.3 μ m and IR2, 11.5-12.5 μ m ), using the Generalized Split-Window (GSW)algorithm proposed by Wan and Dozier (1996). The coefficients in the GSW algorithmcorresponding to a series of overlapping ranging of the mean emissivity, the atmosphericWater Vapor Content (WVC), and the LST were derived using a statistical regressionmethod from the numerical values simulated with an accurate atmospheric radiativetransfer model MODTRAN 4 over a wide range of atmospheric and surface conditions.The simulation analysis showed that the LST could be estimated by the GSW algorithmwith the Root Mean Square Error (RMSE) less than 1 K for the sub-ranges with theViewing Zenith Angle (VZA) less than 30° or for the sub-rangs with VZA less than 60°and the atmospheric WVC less than 3.5 g/cm² provided that the Land Surface Emissivities(LSEs) are known. In order to determine the range for the optimum coefficients of theGSW algorithm, the LSEs could be derived from the data in MODIS channels 31 and 32 provided by MODIS/Terra LST product MOD11B1, or be estimated either according tothe land surface classification or using the method proposed by Jiang et al. (2006); and theWVC could be obtained from MODIS total precipitable water product MOD05, or beretrieved using Li et al.' method (2003). The sensitivity and error analyses in term of theuncertainty of the LSE and WVC as well as the instrumental noise were performed. Inaddition, in order to compare the different formulations of the split-window algorithms,several recently proposed split-window algorithms were used to estimate the LST with thesame simulated FY-2C data. The result of the intercomparsion showed that most of thealgorithms give comparable results.

Aging and the Effects of Exploratory Behavior on Spatial Memory.

PubMed

Varner, Kaitlin M; Dopkins, Stephen; Philbeck, John W

2016-03-01

The present research examined the effect of encoding from multiple viewpoints on scene recall in a group of younger (18-22 years) and older (65-80 years) adults. Participants completed a visual search task, during which they were given the opportunity to examine a room using two sets of windows that partitioned the room differently. Their choice of window set was recorded, to determine whether an association between these choices and spatial memory performance existed. Subsequently, participants were tested for spatial memory of the domain in which the search task was completed. Relative to younger adults, older adults demonstrated an increased tendency to use a single set of windows as well as decreased spatial memory for the domain. Window-set usage was associated with spatial memory, such that older adults who relied more heavily on a single set of windows also had better performance on the spatial memory task. These findings suggest that, in older adults, moderation in exploratory behavior may have a positive effect on memory for the domain of exploration. © The Author(s) 2016.

Simulation-based process windows simultaneously considering two and three conflicting criteria in injection molding

PubMed Central

Rodríguez-Yáñez, Alicia Berenice; Méndez-Vázquez, Yaileen

2014-01-01

Process windows in injection molding are habitually built with only one performance measure in mind. In reality, a more realistic picture can be obtained when considering multiple performance measures at a time, especially in the presence of conflict. In this work, the construction of process windows for injection molding (IM) is undertaken considering two and three performance measures in conflict simultaneously. The best compromises between the criteria involved are identified through the direct application of the concept of Pareto-dominance in multiple criteria optimization. The aim is to provide a formal and realistic strategy to set processing conditions in IM operations. The resulting optimization approach is easily implementable in MS Excel. The solutions are presented graphically to facilitate their use in manufacturing plants. PMID:25530927

Simulation-based process windows simultaneously considering two and three conflicting criteria in injection molding.

PubMed

Rodríguez-Yáñez, Alicia Berenice; Méndez-Vázquez, Yaileen; Cabrera-Ríos, Mauricio

2014-01-01

Process windows in injection molding are habitually built with only one performance measure in mind. In reality, a more realistic picture can be obtained when considering multiple performance measures at a time, especially in the presence of conflict. In this work, the construction of process windows for injection molding (IM) is undertaken considering two and three performance measures in conflict simultaneously. The best compromises between the criteria involved are identified through the direct application of the concept of Pareto-dominance in multiple criteria optimization. The aim is to provide a formal and realistic strategy to set processing conditions in IM operations. The resulting optimization approach is easily implementable in MS Excel. The solutions are presented graphically to facilitate their use in manufacturing plants.

Graphical User Interface for the NASA FLOPS Aircraft Performance and Sizing Code

NASA Technical Reports Server (NTRS)

Lavelle, Thomas M.; Curlett, Brian P.

1994-01-01

XFLOPS is an X-Windows/Motif graphical user interface for the aircraft performance and sizing code FLOPS. This new interface simplifies entering data and analyzing results, thereby reducing analysis time and errors. Data entry is simpler because input windows are used for each of the FLOPS namelists. These windows contain fields to input the variable's values along with help information describing the variable's function. Analyzing results is simpler because output data are displayed rapidly. This is accomplished in two ways. First, because the output file has been indexed, users can view particular sections with the click of a mouse button. Second, because menu picks have been created, users can plot engine and aircraft performance data. In addition, XFLOPS has a built-in help system and complete on-line documentation for FLOPS.

Dynamics of retinal photocoagulation and rupture

NASA Astrophysics Data System (ADS)

Sramek, Christopher; Paulus, Yannis; Nomoto, Hiroyuki; Huie, Phil; Brown, Jefferson; Palanker, Daniel

2009-05-01

In laser retinal photocoagulation, short (<20 ms) pulses have been found to reduce thermal damage to the inner retina, decrease treatment time, and minimize pain. However, the safe therapeutic window (defined as the ratio of power for producing a rupture to that of mild coagulation) decreases with shorter exposures. To quantify the extent of retinal heating and maximize the therapeutic window, a computational model of millisecond retinal photocoagulation and rupture was developed. Optical attenuation of 532-nm laser light in ocular tissues was measured, including retinal pigment epithelial (RPE) pigmentation and cell-size variability. Threshold powers for vaporization and RPE damage were measured with pulse durations ranging from 1 to 200 ms. A finite element model of retinal heating inferred that vaporization (rupture) takes place at 180-190°C. RPE damage was accurately described by the Arrhenius model with activation energy of 340 kJ/mol. Computed photocoagulation lesion width increased logarithmically with pulse duration, in agreement with histological findings. The model will allow for the optimization of beam parameters to increase the width of the therapeutic window for short exposures.

WinHPC System | High-Performance Computing | NREL

Science.gov Websites

System WinHPC System NREL's WinHPC system is a computing cluster running the Microsoft Windows operating system. It allows users to run jobs requiring a Windows environment such as ANSYS and MATLAB

Visual performance assessment through clear and sunscreen-treated windows.

DOT National Transportation Integrated Search

1978-09-01

Reflective sunscreen filters are frequently bonded to vehicle windows to reduce interior heat and brightness. The present study was conducted to investigate the optical properties of and visual preformance through clear and sunscreen-treated glass pa...

Analysis of Environmentally Friendly Refrigerant Options for Window Air Conditioners

DOE PAGES

Bansal, Pradeep; Shen, Bo

2015-03-12

This paper presents a technical assessment of environmentally friendly refrigerants as alternatives to R410A for window air conditioners. The alternative refrigerants that are studied for its replacement include R32, a mixture of R32/R125 with 90%/10% molar concentration, R600a, R290, R1234yf, R1234ze and R134a. Baseline experiments were performed on a window unit charged with R410A. The heat pump design model (HPDM) was modified and calibrated with the baseline data and was used to evaluate the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners. Amongmore » all the refrigerants studied, R32 offers the best efficiency and the lowest Global Warming Potential (GWP), and hence its use will result in the overall environmental friendliness.« less

Exergy Analysis and Operational Efficiency of a Horizontal Ground Source Heat Pump System Operated in a Low-Energy Test House under Simulated Occupancy Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ally, Moonis Raza; Baxter, Van D; Munk, Jeffrey D

2012-01-01

This paper presents data, analyses, measures of performance, and conclusions for a ground-source heat pump (GSHP) providing space conditioning to a 345m2 house whose envelope is made of structural insulated panels (SIP). The entire thermal load of this SIP house with RSI-3.7 (RUS-21) walls, triple pane windows with a U-factor of 1.64 W/m2 K (0.29 Btu/h ft2 oF) and solar heat gain coefficient (SHGC) of 0.25, a roof assembly with overall thermal resistance of about RSI-8.8 (RUS-50) and low leakage rates of 0.74 ACH at 50Pa was satisfied with a 2.16-Ton (7.56 kW) GSHP unit consuming negligible (9.83kWh) auxiliary heatmore » during peak winter season. The highest and lowest heating COP achieved was 4.90 (October) and 3.44 (February), respectively. The highest and lowest cooling COP achieved was 6.09 (April) and 3.88 (August). These COPs are calculated on the basis of the total power input (including duct, ground loop, and control power losses ). The second Law (Exergy) analysis provides deep insight into how systemic inefficiencies are distributed among the various GSHP components. Opportunities for design and further performance improvements are identified. Through Exergy analysis we provide a true measure of how closely actual performance approaches the ideal, and it unequivocally identifies, better than energy analysis does, the sources and causes of lost work, the root cause of system inefficiencies.« less

Encapsulation of ZnO particles by metal fluorides: Towards an application as transparent insulating coatings for windows

NASA Astrophysics Data System (ADS)

Trenque, Isabelle; Mornet, Stéphane; Duguet, Etienne; Majimel, Jérôme; Brüll, Annelise; Teinz, Katharina; Kemnitz, Erhard; Gaudon, Manuel

2013-01-01

Because ZnO is a promising candidate for getting efficient films or varnishes with thermal insulating abilities for windows applications, the effect of the encapsulation of ZnO particles in shells of low refractive index material on the improvement of the visible light transmission was investigated. ZnO-MgF2 core-shell particles were synthesized by deposition of fluoride sols on ZnO particles through a vacuum slip casting process like. The transmission behaviours were first indirectly studied by diffuse reflexion measurements on powder beds. Then, particle films were elaborated by a screen printing process which ensured direct transmission measurements. The encapsulation of ZnO particles with a coating shell of 1.3 wt.% of MgF2 improves the visible light transmission of 32%.

Intrapleural fluid infusion for MR-guided high-intensity focused ultrasound ablation in the liver dome.

PubMed

Wijlemans, Joost W; de Greef, Martijn; Schubert, Gerald; Moonen, Chrit T W; van den Bosch, Maurice A A J; Ries, Mario

2014-12-01

Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation of tumors in the liver dome is challenging because of the presence of air in the costophrenic angle. In this study, we used a porcine liver model and a clinical MR-HIFU system to assess the feasibility and safety of using intrapleural fluid infusion (IPI) to create an acoustic window for MR-HIFU ablation in the liver dome. Healthy adult Dalland land pigs (n = 6) under general anesthesia were used with animal committee approval. Degassed saline (200-800 mL) was infused into the intrapleural space under ultrasound guidance. A clinical 1.5-T MR-HIFU system was used to perform sonications (4-mm treatment cells, 300-450 W, 20-30 seconds) in the liver dome under real-time MR thermometry. An intercostal firing technique was used to prevent rib heating in one experiment. Technical success was defined as a temperature increase (>10°C) in the target area. After termination, the animal was examined for thermal damage to liver, diaphragm, pleura, lung, or intercostal muscle. An acoustic window was established in all animals. A temperature increase in the target area was achieved in all animals (max. 47°C-67°C). MR thermometry showed no heating outside the target area. Intercostal firing effectively reduced rib heating (55°C vs. 42°C). Postmortem examination revealed no unwanted thermal damage. One complication occurred, in the first experiment, because of an ill-suited needle (displacement of the needle). The results indicate that IPI may be used safely to assist MR-HIFU ablation of tumors in the liver dome. For reliable tissue coagulation, IPI must be combined with an intercostal sonication technique. Considering the proportion of patients with tumors in the liver dome, IPI widens the applicability of MR-HIFU ablation for liver tumors considerably. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

Derivation of cloud-free-region atmospheric motion vectors from FY-2E thermal infrared imagery

NASA Astrophysics Data System (ADS)

Wang, Zhenhui; Sui, Xinxiu; Zhang, Qing; Yang, Lu; Zhao, Hang; Tang, Min; Zhan, Yizhe; Zhang, Zhiguo

2017-02-01

The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors (AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the retrieved AMVs are mostly in the upper troposphere. As the noise-equivalent temperature difference (NEdT) performance of FY-2E split window (10.3-11.5 μm, 11.6-12.8 μm) channels has been improved, the weak signals representing the spatial texture of water vapor and aerosols in cloud-free areas can be strengthened with algorithms based on the difference principle, and applied in calculating AMVs in the lower troposphere. This paper is a preliminary summary for this purpose, in which the principles and algorithm schemes for the temporal difference, split window difference and second-order difference (SD) methods are introduced. Results from simulation and cases experiments are reported in order to verify and evaluate the methods, based on comparison among retrievals and the "truth". The results show that all three algorithms, though not perfect in some cases, generally work well. Moreover, the SD method appears to be the best in suppressing the surface temperature influence and clarifying the spatial texture of water vapor and aerosols. The accuracy with respect to NCEP 800 hPa reanalysis data was found to be acceptable, as compared with the accuracy of the cloud motion vectors.

A large, switchable optical clearing skull window for cerebrovascular imaging

PubMed Central

Zhang, Chao; Feng, Wei; Zhao, Yanjie; Yu, Tingting; Li, Pengcheng; Xu, Tonghui; Luo, Qingming; Zhu, Dan

2018-01-01

Rationale: Intravital optical imaging is a significant method for investigating cerebrovascular structure and function. However, its imaging contrast and depth are limited by the turbid skull. Tissue optical clearing has a great potential for solving this problem. Our goal was to develop a transparent skull window, without performing a craniotomy, for use in assessing cerebrovascular structure and function. Methods: Skull optical clearing agents were topically applied to the skulls of mice to create a transparent window within 15 min. The clearing efficacy, repeatability, and safety of the skull window were then investigated. Results: Imaging through the optical clearing skull window enhanced both the contrast and the depth of intravital imaging. The skull window could be used on 2-8-month-old mice and could be expanded from regional to bi-hemispheric. In addition, the window could be repeatedly established without inducing observable inflammation and metabolic toxicity. Conclusion: We successfully developed an easy-to-handle, large, switchable, and safe optical clearing skull window. Combined with various optical imaging techniques, cerebrovascular structure and function can be observed through this optical clearing skull window. Thus, it has the potential for use in basic research on the physiopathologic processes of cortical vessels. PMID:29774069

Protective broadband window coatings

NASA Astrophysics Data System (ADS)

Askinazi, Joel; Narayanan, Authi A.

1997-06-01

Optical windows employed in current and future airborne and ground based optical sensor systems are required to provide long service life under extreme environmental conditions including blowing sand and high speed rain. State of the art sensor systems are employing common aperture windows which must provide optical bandpasses from the TV to the LWIR. Operation Desert Storm experience indicates that current optical coatings provide limited environmental protection which adversely affects window life cycle cost. Most of these production coatings also have limited optical bandpasses (LWIR, MWIR, or TV-NIR). A family of optical coatings has been developed which provide a significant increase in rain and sand impact protection to current optical window materials. These coatings can also be tailored to provide either narrow optical bandwidth (e.g., LWIR) or broadband transmittance (TV- LWIR). They have been applied to a number of standard optical window materials. These coating have successfully completed airborne rain and sand abrasion test with minimal impact on optical window performance. Test results are presented. Low cost service life is anticipated as well as the ability to operate windows in even more taxing environments than currently feasible.

Indium Phosphide Window Layers for Indium Gallium Arsenide Solar Cells

NASA Technical Reports Server (NTRS)

Jain, Raj K.

2005-01-01

Window layers help in reducing the surface recombination at the emitter surface of the solar cells resulting in significant improvement in energy conversion efficiency. Indium gallium arsenide (In(x)Ga(1-x)As) and related materials based solar cells are quite promising for photovoltaic and thermophotovoltaic applications. The flexibility of the change in the bandgap energy and the growth of InGaAs on different substrates make this material very attractive for multi-bandgap energy, multi-junction solar cell approaches. The high efficiency and better radiation performance of the solar cell structures based on InGaAs make them suitable for space power applications. This work investigates the suitability of indium phosphide (InP) window layers for lattice-matched In(0.53)Ga(0.47)As (bandgap energy 0.74 eV) solar cells. We present the first data on the effects of the p-type InP window layer on p-on-n lattice-matched InGaAs solar cells. The modeled quantum efficiency results show a significant improvement in the blue region with the InP window. The bare InGaAs solar cell performance suffers due to high surface recombination velocity (10(exp 7) cm/s). The large band discontinuity at the InP/InGaAs heterojunction offers a great potential barrier to minority carriers. The calculated results demonstrate that the InP window layer effectively passivates the solar cell front surface, hence resulting in reduced surface recombination and therefore, significantly improving the performance of the InGaAs solar cell.

Ground and satellite-based remote sensing of mineral dust using AERI spectra and MODIS thermal infrared window brightness temperatures

NASA Astrophysics Data System (ADS)

Hansell, Richard Allen, Jr.

The radiative effects of dust aerosol on our climate system have yet to be fully understood and remain a topic of contemporary research. To investigate these effects, detection/retrieval methods for dust events over major dust outbreak and transport areas have been developed using satellite and ground-based approaches. To this end, both the shortwave and longwave surface radiative forcing of dust aerosol were investigated. The ground-based remote sensing approach uses the Atmospheric Emitted Radiance Interferometer brightness temperature spectra to detect mineral dust events and to retrieve their properties. Taking advantage of the high spectral resolution of the AERI instrument, absorptive differences in prescribed thermal IR window sub-band channels were exploited to differentiate dust from cirrus clouds. AERI data collected during the UAE2 at Al-Ain UAE was employed for dust retrieval. Assuming a specified dust composition model a priori and using the light scattering programs of T-matrix and the finite difference time domain methods for oblate spheroids and hexagonal plates, respectively, dust optical depths have been retrieved and compared to those inferred from a collocated and coincident AERONET sun-photometer dataset. The retrieved optical depths were then used to determine the dust longwave surface forcing during the UAE2. Likewise, dust shortwave surface forcing is investigated employing a differential technique from previous field studies. The satellite-based approach uses MODIS thermal infrared brightness temperature window data for the simultaneous detection/separation of mineral dust and cirrus clouds. Based on the spectral variability of dust emissivity at the 3.75, 8.6, 11 and 12 mum wavelengths, the D*-parameter, BTD-slope and BTD3-11 tests are combined to identify dust and cirrus. MODIS data for the three dust-laden scenes have been analyzed to demonstrate the effectiveness of this detection/separation method. Detected daytime dust and cloud coverage for the Persian Gulf case compare reasonably well to those from the "Deep Blue" algorithm developed at NASA-GSFC. The nighttime dust/cloud detection for the cases surrounding Cape Verde and Niger, West Africa has been validated by comparing to coincident and collocated ground-based micro-pulse lidar measurements.

Near Infrared Multispectral Mapping of Venus Supports the Hypothesis that Tessera Plateau Material was Formed in the Presence of Surface Water

NASA Astrophysics Data System (ADS)

Mueller, N. T.; Tsang, C.; Nunes, D. C.; Helbert, J.; Dyar, M. D.; Smrekar, S. E.

2017-12-01

The VIRTIS instrument on Venus Express observed surface thermal emission from the surface. Studies of 1020nm data showed that tessera plateaus, intensely tectonically deformed highlands that predate most other terrains, have significantly lower thermal emission than other highlands. Lower thermal emission could be due either to lower surface emissivity, supporting the hypothesis that tessera are analogous to continental crust on Earth, or to a bias of Magellan altimetry, which does not fully resolve the topographic relief of tessera terrain. To eliminate this ambiguity, we additionally investigate the spectral windows at 1100 and 1180nm. Data are reduced to surface emissivity using an atmospheric radiative transfer model to account for atmospheric scattering and absorption/emission. Magellan altimetry was used to model atmospheric column height and surface temperature. The model uses a binary (collision-induced) absorption coefficient for each window. It fits absolute radiance and gradient with surface elevation reasonably well, although there are indications that the assumed adiabatic temperature lapse rate is not appropriate globally. The 1100nm band has a relatively low signal-to-noise ratio at the latitudes of the tessera plateaus, but Alpha Regio is visible in both the 1020 and the 1180nm band. The difference in emissivity between Alpha and the adjacent corona Eve, which has a similar elevation as Alpha, is 3.6% at 1020nm, but only 2% at 1180nm. The altimetry bias equivalent to the 1020nm deviation is 230 m, while the equivalent is only 70m at 1180nm. An altimetry bias therefore cannot fully explain the observations, and there must be a real difference in emissivity. The observations are consistent with the hypothesis that Alpha Regio has a more felsic composition. The emissivity spectra of granites at Venus temperatures are lower than those of basalt at 1020nm, but the difference decreases or vanishes towards the 1180nm window. The most plausible explanation for continent-sized felsic plateaus would be a formation analogous to Earth's continents, i.e. differentiation of basaltic crust in the presence of water.

Effect of fee-for-service air-conditioning management in balancing thermal comfort and energy usage.

PubMed

Chen, Chen-Peng; Hwang, Ruey-Lung; Shih, Wen-Mei

2014-11-01

Balancing thermal comfort with the requirement of energy conservation presents a challenge in hot and humid areas where air-conditioning (AC) is frequently used in cooling indoor air. A field survey was conducted in Taiwan to demonstrate the adaptive behaviors of occupants in relation to the use of fans and AC in a school building employing mixed-mode ventilation where AC use was managed under a fee-for-service mechanism. The patterns of using windows, fans, and AC as well as the perceptions of students toward the thermal environment were examined. The results of thermal perception evaluation in relation to the indoor thermal conditions were compared to the levels of thermal comfort predicted by the adaptive models described in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 55 and EN 15251 and to that of a local model for evaluating thermal adaption in naturally ventilated buildings. A thermal comfort-driven adaptive behavior model was established to illustrate the probability of fans/AC use at specific temperature and compared to the temperature threshold approach to illustrate the potential energy saving the fee-for-service mechanism provided. The findings of this study may be applied as a reference for regulating the operation of AC in school buildings of subtropical regions.

Platform for Postprocessing Waveform-Based NDE

NASA Technical Reports Server (NTRS)

Roth, Don

2008-01-01

Taking advantage of the similarities that exist among all waveform-based non-destructive evaluation (NDE) methods, a common software platform has been developed containing multiple- signal and image-processing techniques for waveforms and images. The NASA NDE Signal and Image Processing software has been developed using the latest versions of LabVIEW, and its associated Advanced Signal Processing and Vision Toolkits. The software is useable on a PC with Windows XP and Windows Vista. The software has been designed with a commercial grade interface in which two main windows, Waveform Window and Image Window, are displayed if the user chooses a waveform file to display. Within these two main windows, most actions are chosen through logically conceived run-time menus. The Waveform Window has plots for both the raw time-domain waves and their frequency- domain transformations (fast Fourier transform and power spectral density). The Image Window shows the C-scan image formed from information of the time-domain waveform (such as peak amplitude) or its frequency-domain transformation at each scan location. The user also has the ability to open an image, or series of images, or a simple set of X-Y paired data set in text format. Each of the Waveform and Image Windows contains menus from which to perform many user actions. An option exists to use raw waves obtained directly from scan, or waves after deconvolution if system wave response is provided. Two types of deconvolution, time-based subtraction or inverse-filter, can be performed to arrive at a deconvolved wave set. Additionally, the menu on the Waveform Window allows preprocessing of waveforms prior to image formation, scaling and display of waveforms, formation of different types of images (including non-standard types such as velocity), gating of portions of waves prior to image formation, and several other miscellaneous and specialized operations. The menu available on the Image Window allows many further image processing and analysis operations, some of which are found in commercially-available image-processing software programs (such as Adobe Photoshop), and some that are not (removing outliers, Bscan information, region-of-interest analysis, line profiles, and precision feature measurements).

Longitudinal discharge laser baffles

DOEpatents

Warner, Bruce E.; Ault, Earl R.

1994-01-01

The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam.

How climate change will affect sessile stages of brown trout (Salmo trutta) in mountain streams of the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Santiago, José M.; Alonso, Carlos; García de Jalón, Diego; Solana, Joaquín

2017-04-01

Streamflow and temperature regimes are determinant for the availability of suitable physical habitat for instream biological communities. Iberian brown trout (Salmo trutta) populations live in a climatic border in which summer water scarcity and raising temperatures will compromise their viability throughout the current century. Due to their impaired mobility, sessile stages of trout life cycle (i.e. eggs and larvae) are among the most sensitive organisms to environmental changing conditions. At a given spawning redd, thermal habitat is limited by the length of the period at which suitable temperatures occur. At the same time, suitable physical habitat is limited by the instream flow regime during spawning and incubation of eggs and larvae. Temperature and flow do also interact, thus producing synergistic effects on both physical and thermal habitats. This study is aimed at quantitatively predicting thermal and physical habitat loss for the sessile stages of brown trout life cycle due to clime change, in mountain streams at the rear edge of the species natural distribution using high-resolution spatial-temporal simulations of the thermal and physical habitat. Two streams of Central Spain have been studied (Cega and Lozoya streams). Daily temperature and flow data from ad hoc downscaled IPCC (RCP4.5 and RCP8.5) predictions were used as input variables. Physical habitat changes were simulated from previously predicted stream flow data by means of hydraulic simulation tools (River2D). By taking into account the thermal tolerance limits and the proportion of lost physical habitat, limiting factors for the reproduction of brown trout in the study area were determined. The general increase of mean temperatures shortens the duration of the early developmental stages. This reduction of the sessile period is rather similar in both RCP4.5 and RCP8.5 scenarios by 2050. Differences between both scenarios become greater by 2099. The duration of sessile developmental is reduced in 12 days (-10%) according to scenario RCP4.5 and as much as 30 days (-25%) according to RCP8.5 in the Cega stream. Reduction of this sessile period in the Lozoya stream ranges between 14 days (-12%) in RCP4.5 and 35 (-29%) in RCP8.5. However, this acceleration of the development is not sufficient to compensate the much greater reduction of the thermal window in which mean water temperature remain below 10°C (considered a critical threshold). In the Cega stream, suitable thermal window reduction will range between 21% (RCP4.5) and 49% (RCP8.5) by 2099. In contrast, the Lozoya stream will lose much less time of suitable temperatures by 2099: 3% and 21%, according to RCP4.5 and RCP8.5, respectively. Although habitat reductions will be significant during the spawning season, the most important problems for trout population viability seem to be related to the reduction of the available time window for embryos and larvae to complete their development. Besides, due to the differential sensitivity of instream thermal habitat to a general increase in air temperature, it is highly recommendable to address locally adapted mitigation programs to avoid a general retraction of the current native range of this species.

The strain and thermal induced tunable charging phenomenon in low power flexible memory arrays with a gold nanoparticle monolayer

NASA Astrophysics Data System (ADS)

Zhou, Ye; Han, Su-Ting; Xu, Zong-Xiang; Roy, V. A. L.

2013-02-01

The strain and temperature dependent memory effect of organic memory transistors on plastic substrates has been investigated under ambient conditions. The gold (Au) nanoparticle monolayer was prepared and embedded in an atomic layer deposited aluminum oxide (Al2O3) as the charge trapping layer. The devices exhibited low operation voltage, reliable memory characteristics and long data retention time. Experimental analysis of the programming and erasing behavior at various bending states showed the relationship between strain and charging capacity. Thermal-induced effects on these memory devices have also been analyzed. The mobility shows ~200% rise and the memory window increases from 1.48 V to 1.8 V when the temperature rises from 20 °C to 80 °C due to thermally activated transport. The retention capability of the devices decreases with the increased working temperature. Our findings provide a better understanding of flexible organic memory transistors under various operating temperatures and validate their applications in various areas such as temperature sensors, temperature memory or advanced electronic circuits. Furthermore, the low temperature processing procedures of the key elements (Au nanoparticle monolayer and Al2O3 dielectric layer) could be potentially integrated with large area flexible electronics.The strain and temperature dependent memory effect of organic memory transistors on plastic substrates has been investigated under ambient conditions. The gold (Au) nanoparticle monolayer was prepared and embedded in an atomic layer deposited aluminum oxide (Al2O3) as the charge trapping layer. The devices exhibited low operation voltage, reliable memory characteristics and long data retention time. Experimental analysis of the programming and erasing behavior at various bending states showed the relationship between strain and charging capacity. Thermal-induced effects on these memory devices have also been analyzed. The mobility shows ~200% rise and the memory window increases from 1.48 V to 1.8 V when the temperature rises from 20 °C to 80 °C due to thermally activated transport. The retention capability of the devices decreases with the increased working temperature. Our findings provide a better understanding of flexible organic memory transistors under various operating temperatures and validate their applications in various areas such as temperature sensors, temperature memory or advanced electronic circuits. Furthermore, the low temperature processing procedures of the key elements (Au nanoparticle monolayer and Al2O3 dielectric layer) could be potentially integrated with large area flexible electronics. Electronic supplementary information (ESI) available: UV-vis spectrum of Au nanoparticle aqueous solution, transfer characteristics of the transistors without inserting an Au nanoparticle monolayer, AFM image of the pentacene layer, transfer characteristics at different program voltages and memory windows with respect to the P/E voltage. See DOI: 10.1039/c2nr32579a

Window Performance in Extreme Cold,

DTIC Science & Technology

1982-12-01

outdoor temperatures ranging between -40 and 20*F Alaska that have undergone an extensive window re- as shown in Table 2. We made these observations in...good predictor of when We made icing and condensation observations over moisture or ice would occur on a window pane. the temperature spectrum shown...tions were made during the daytime, it was often likely sashes or frames, and 4) vapor-loose indoor sashes that ATIo at the time of observation would

Thermal maturity of northern Appalachian Basin Devonian shales: Insights from sterane and terpane biomarkers

USGS Publications Warehouse

Hackley, Paul C.; Ryder, Robert T.; Trippi, Michael H.; Alimi, Hossein

2013-01-01

To better estimate thermal maturity of Devonian shales in the northern Appalachian Basin, eleven samples of Marcellus and Huron Shale were characterized via multiple analytical techniques. Vitrinite reflectance, Rock–Eval pyrolysis, gas chromatography (GC) of whole rock extracts, and GC–mass spectrometry (GCMS) of extract saturate fractions were evaluated on three transects that lie across previously documented regional thermal maturity isolines. Results from vitrinite reflectance suggest that most samples are immature with respect to hydrocarbon generation. However, bulk geochemical data and sterane and terpane biomarker ratios from GCMS suggest that almost all samples are in the oil window. This observation is consistent with the presence of thermogenic gas in the study area and higher vitrinite reflectance values recorded from overlying Pennsylvanian coals. These results suggest that vitrinite reflectance is a poor predictor of thermal maturity in early mature areas of Devonian shale, perhaps because reported measurements often include determinations of solid bitumen reflectance. Vitrinite reflectance interpretations in areas of early mature Devonian shale should be supplanted by evaluation of thermal maturity information from biomarker ratios and bulk geochemical data.

The study of the thermal imaging law on several objects in winter environment

NASA Astrophysics Data System (ADS)

Wang, Xuan-yu; Pang, Min-hui

2013-09-01

Some thermal imaging experiments have been done about a building with a door made of iron, copperplate and aluminum flake, several trees, marbles, a glass window and a concrete wall under different conditions in a winter day while the environmental temperature and relative humidity are simultaneously measured by an electronic sensor. The experimental results show that the thermal imaging temperatures of the targets are related to the category of materials, and presenting some laws with the environment temperature changing. All of the thermal imaging temperature of the targets obviously varies with the atmospheric environment temperature by the large temperature difference. The changes of the surface temperature of metals are more obviously than nonmetals. The thermal imaging temperature of the door made of iron is more easily affected by the atmospheric environment temperature than copperplate while aluminum flake is more difficultly affected than copperplate under the same condition. The temperature of an ordinary concrete wall is obviously higher than the one painted by oil paint. Under the same condition, the changes of glasses are the most in all of the nonmetal targets.