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Sample records for ground ultra-low volume

  1. The impact of sequential ultra-low volume ground aerosol applications of malathion on the population dynamics of Aedes aegypti (L.).

    Science.gov (United States)

    Focks, D A; Kloter, K O; Carmichael, G T

    1987-05-01

    The efficacy of sequential, ultra-low volume ground aerosol applications of malathion at current U.S. label rates was evaluated as an emergency control measure for adult populations of Aedes aegypti (L.) in New Orleans, Louisiana. Replicates of 11 sequential aerosol treatments applied 12 hr apart during a 5.5-day period reduced mean adult captures and oviposition rates during the treatment period 73% and 75%, respectively. We hypothesize that oviposition was not completely suppressed because females with a developing egg burden remained sequestered during treatment periods or were more tolerant to the pesticide. We further concluded that adults could not be totally suppressed because of continued emergence. After treatment, adult densities recovered to pretreatment and control levels within approximately 1 week. A simulation study of the results suggested that, under the conditions of closely spaced housing and abundant vegetation that is typical of much of New Orleans, a single aerosol killed an average of 88% of the males and only 30% of the females present.

  2. PREPARATION OF ULTRA-LOW VOLUME WEIGHT AUTOCLAVED AERATED CONCRETE

    Directory of Open Access Journals (Sweden)

    Ondrej Koutny

    2016-12-01

    Full Text Available Autoclaved aerated concrete is a modern construction material that gains its popularity especially due to its thermal insulation performance resulting from low volume weight and porous structure with sufficient mechanical strength. Nowadays, there are attempts to use this material for thermal insulation purposes and to replace current systems, which have many disadvantages, mainly concerning durability. The key for improvement of thermal insulation properties is therefore obtaining a material based on autoclaved aerated concrete with extremely low volume weight (below 200 kg/m ³ ensuring good thermal isolation properties, but with sufficient mechanical properties to allow easy manipulation. This material can be prepared by foaming very fine powder materials such as silica fume or very finely ground sand. This paper deals with the possibilities of preparation and summarizes the basic requirements for successful preparation of such a material.

  3. The mosquito ultra-low volume dispersion model for estimating environmental concentrations of insecticides used for adult mosquito management.

    Science.gov (United States)

    Schleier, Jerome J; Peterson, Robert K D

    2014-09-01

    Computer models for pesticide drift are widely used tools by regulatory agencies to estimate the deposition of pesticides beyond the intended target area. Currently, there is no model in use that has been validated or verified as an accurate means of estimating concentrations of insecticides after ground-based ultra-low volume (ULV) applications used for adult mosquito management. To address the need for a validated model we created a spreadsheet-based model called Mosquito Ultra-Low Volume Dispersion (MULV-Disp) to aid in the adoption and to provide easier use of a validated model. We explain the origin, use, and utility of MULV-Disp, which can be used by regulatory agencies and other interested parties to estimate deposition of ULV insecticides.

  4. A Technical Review of MULV-Disp, a Recent Mosquito Ultra-Low Volume Pesticide Spray Dispersion Model.

    Science.gov (United States)

    Teske, Milton E; Thistle, Harold W; Bonds, Jane A S

    2015-09-01

    The authors of a recently published paper summarized the development of a regression model for ground-based ultra-low volume applications, suggesting that their model was sufficiently verified that it could be used extensively for mosquito control. These authors claimed that their statistical model was superior in its predictive capability to the extensively developed and Environmental Protection Agency-validated AGDISP mechanistic model. In this technical review, the assumptions, reduction and interpretation of data, and conclusions reached with regard to their model are discussed, and explicit misstatements and incorrect mathematical relationships are pointed out. Two published versions of the model regression equation give substantially different results without explanation. Petri dish collection was used for very small droplets, with no mention of collection efficiency. Meteorological data were misused based on manufacturer's specification of instrument accuracy. We strongly disagree with many of the model results and show that the model misrepresents the actual behavior of aerosol sprays applied in the manner tested.

  5. Field evaluation of indoor thermal fog and ultra-low volume applications for control of Aedes aegypti, in Thailand

    Science.gov (United States)

    Efficacies of a hand-held thermal fogger (PatriotTM) and hand-held Ultra-low volume (ULV) sprayer (TwisterTM) with combinations of two different adulticides and an insect growth regulator (pyriproxyfen) were field assessed and compared for their impact on reducing dengue vector populations in Thaila...

  6. Determinants of acute mortality of Hippodamia convergens (Coleoptera: Coccinellidae) to ultra-low volume permethrin used for mosquito management.

    Science.gov (United States)

    Peterson, Robert K D; Preftakes, Collin J; Bodin, Jennifer L; Brown, Christopher R; Piccolomini, Alyssa M; Schleier, Jerome J

    2016-01-01

    There are relatively few experimental studies and risk assessments of the effects on non-target insects from ultra-low volume (ULV) insecticides used for management of adult mosquitoes. Therefore, we evaluated factors that may influence the ability of an insect to intercept the insecticide at the time of application by using Hippodamia convergens (Coleoptera: Coccinellidae) in field bioassay experiments in 2011 and 2015. Treatment factors included different distances, two cage heights (ground-level and 1.5 m above ground) to the point of the application, and covered vs. uncovered cage faces (2015 only). Insecticides used included a water-based formulation (Aqua-Reslin®) and an oil-based formulation (Permanone® 30-30) of permethrin. Cage height was highly significant both years, with much less acute (i.e., short-term exposure) mortality at ground-level compared with 1.5 m. In 2011, acute mortality was less at ground-level (mean = 3.2%, median = 0%) compared to 1.5 m (mean = 85.2%, median = 100%). Cage type also was highly significant, with less mortality in covered cages compared to uncovered cages. Mortality by cage height and cage type was as follows: ground level, covered cage (mean = 2.8%, median = 0.1%); ground level, uncovered cage (mean = 41.9%, median = 9.6%); 1.5 m, covered cage (mean = 6.8%, median = 0%); 1.5 m, uncovered cage (mean = 83.7%, median = 100%). Results suggest that acute mortality to non-target insects may vary considerably based on their height and their ability to directly intercept the insecticide as the aerosol passes through the area being sprayed.

  7. Ultra Low Volume Dispersal of Insecticides by Ground Equipment

    Science.gov (United States)

    1999-12-01

    measured before they evaporate. To prevent excessive spreading, filming, or coalescence, the slide must be coated with an oleophobic substance that will...cleaning solution, dried, then immersed in the oleophobic coating solution, and redried. When dry the slides should be lightly polished with a soft

  8. Environmental fate model for ultra-low-volume insecticide applications used for adult mosquito management.

    Science.gov (United States)

    Schleier, Jerome J; Peterson, Robert K D; Irvine, Kathryn M; Marshall, Lucy M; Weaver, David K; Preftakes, Collin J

    2012-11-01

    One of the more effective ways of managing high densities of adult mosquitoes that vector human and animal pathogens is ultra-low-volume (ULV) aerosol applications of insecticides. The U.S. Environmental Protection Agency uses models that are not validated for ULV insecticide applications and exposure assumptions to perform their human and ecological risk assessments. Currently, there is no validated model that can accurately predict deposition of insecticides applied using ULV technology for adult mosquito management. In addition, little is known about the deposition and drift of small droplets like those used under conditions encountered during ULV applications. The objective of this study was to perform field studies to measure environmental concentrations of insecticides and to develop a validated model to predict the deposition of ULV insecticides. The final regression model was selected by minimizing the Bayesian Information Criterion and its prediction performance was evaluated using k-fold cross validation. Density of the formulation and the density and CMD interaction coefficients were the largest in the model. The results showed that as density of the formulation decreases, deposition increases. The interaction of density and CMD showed that higher density formulations and larger droplets resulted in greater deposition. These results are supported by the aerosol physics literature. A k-fold cross validation demonstrated that the mean square error of the selected regression model is not biased, and the mean square error and mean square prediction error indicated good predictive ability.

  9. Environmental fate model for ultra-low-volume insecticide applications used for adult mosquito management

    Science.gov (United States)

    Schleier, Jerome J.; Peterson, Robert K.D.; Irvine, Kathryn M.; Marshall, Lucy M.; Weaver, David K.; Preftakes, Collin J.

    2012-01-01

    One of the more effective ways of managing high densities of adult mosquitoes that vector human and animal pathogens is ultra-low-volume (ULV) aerosol applications of insecticides. The U.S. Environmental Protection Agency uses models that are not validated for ULV insecticide applications and exposure assumptions to perform their human and ecological risk assessments. Currently, there is no validated model that can accurately predict deposition of insecticides applied using ULV technology for adult mosquito management. In addition, little is known about the deposition and drift of small droplets like those used under conditions encountered during ULV applications. The objective of this study was to perform field studies to measure environmental concentrations of insecticides and to develop a validated model to predict the deposition of ULV insecticides. The final regression model was selected by minimizing the Bayesian Information Criterion and its prediction performance was evaluated using k-fold cross validation. Density of the formulation and the density and CMD interaction coefficients were the largest in the model. The results showed that as density of the formulation decreases, deposition increases. The interaction of density and CMD showed that higher density formulations and larger droplets resulted in greater deposition. These results are supported by the aerosol physics literature. A k-fold cross validation demonstrated that the mean square error of the selected regression model is not biased, and the mean square error and mean square prediction error indicated good predictive ability.

  10. Deposition from Ultra-Low Volume Application of Public Health Insecticides in a Hot Desert Environment.

    Science.gov (United States)

    Fisher, Michael L; Hoel, David F; Farooq, Muhammad; Walker, Todd W

    2015-06-01

    Three insecticides commonly used for mosquito and sand fly control were applied 30 min to 3 h after sunset during June and July 2010, at Camp Buehring, Kuwait, to determine the relative quantity of pesticides to height and distance traveled in a hot desert environment. A BVA dilution oil was used for the control. Oil-based adulticides were sprayed using a truck-mounted Curtis DynaFog Maxi-Pro 4 ultra-low volume (ULV) sprayer. Malathion (Fyfanon ULV, 96% active ingredient [AI]), resmethrin (Scourge 4+12, 4% AI), pyrethrins (ULD BP-300, 3% AI), and BVA Spray 13 (100% refined petroleum distillate) were mixed with Uvitex optical brightener fluorescent dye and applied at 2 speeds on evenings when wind speed was less than 16.1 km/h (10 mph). Collection targets using biodegradable cotton ribbons (1 m×2.5 cm) were later read with a fluorometer to quantify the amount of insecticide deposited on targets set at heights of 15.2, 76.2, and 152.4 cm (6, 30, and 60 in.) and distances of 1.5, 6.1, 15.2, 30.5, 61.0, and 91.4 m (5, 20, 50, 100, 200, and 300 ft). Mean insecticide deposition across all distances was 31% on 76.2-cm targets and 49% on 152.4-cm targets, while 15.2-cm targets typically collected insecticide deposition was 80% at or above 76.2 cm for all insecticides. This finding may explain in part why control of low-flying phlebotomine sand flies with ULV insecticides has been met with less than optimal success by US military forces deployed in the Middle East.

  11. Environmental Assessment - Proposed Application of Aerially Applied Ultra Low Volume Naled for the Control of Adult Mosquitoes within the Big Branch Marsh National Wildlife Refuge in Lacombe, Louisiana

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document assesses the effects that aerially applied ultra low volume Naled would have on adult mosquito populations. It also offers alternatives.

  12. Temporal and storage effects on ultra-low volume droplets of insecticides collected on Teflon-coated slides.

    Science.gov (United States)

    Farooq, Muhammad; Lloyd, Aaron M; Estep, Alden S; Walker, Todd W; Hughes, Tony

    2013-12-01

    Use of microscope slides is the most commonly used method to field-assess the droplet spectrum of ultra-low volume (ULV) sprays. Due to absence of analysis facilities during military deployments, slides must be stored and shipped, and the impact of delays in processing and storage conditions on droplets is unknown. This study was designed to evaluate the effect of storage temperatures and duration on droplets on Teflon-coated slides. Treatments included BVA-13 mineral oil, Kontrol 30-30 (30% permethrin), and Fyfanon (96.5% malathion), 2 slide wrapping techniques (proper and improper), and 2 storage temperatures (23 and 45 degrees C), replicated 6 times. The same areas of a slide were measured at different times for 56-58 days using the DropVision droplet measurement system. Regardless of the wrapping technique, droplets of BVA-13, Fyfanon, and Kontrol 30-30 on slides stored at 45 degrees C reduced significantly after 1, 2, and 1 day, respectively, but droplets on slides stored at 23 degrees C were not significantly affected. The results of this study may assist vector control professionals to accurately interpret the droplet size and help in the effective dispersal of ULV-applied insecticides.

  13. Controlling Aedes aegypti in Cryptic Environments with Manually Carried Ultra-Low Volume and Mist Blower Pesticide Applications.

    Science.gov (United States)

    Harwood, James F; Helmey, Wendy L; Turnwall, Brent B; Justice, Kevin D; Farooq, Muhammed; Richardson, Alec G

    2016-09-01

    Because Aedes aegypti , a vector of dengue, chikungunya, and Zika viruses, exhibits resting and reproductive behaviors that present challenges to control them, pesticide application equipment available for vector control must be evaluated for their ability to control this species in a variety of cryptic environments. Five types of pesticide sprayers, representing 3 spray technologies (1 mister, 2 ultra-low volume [ULV] cold foggers, and 2 ULV thermal foggers), were evaluated for their ability to control adult and immature stages of Ae. aegypti in indoor and outdoor environments. Cages holding adult mosquitoes and larvae were placed in cryptic sites for indoor sprays and placed among dense vegetation for outdoor sprays. Adult and pupal mortality data were recorded following applications of a mixture of synergized pyrethrins and pyriproxyfen. We found that no single sprayer was best suited for controlling Ae. aegypti in indoor and outdoor environments, nor was one best for controlling adult and immature mosquitoes. Sprayers producing larger droplets (misters and cold foggers) were more effective in controlling immature mosquitoes indoors and outdoors. Thermal fogging was more effective in controlling adults indoors, whereas cold fogs and misters were more effective for outdoor control.

  14. Effectiveness of indoor ultra-low volume application of Aqua Reslin® Super during an emergency.

    Science.gov (United States)

    Ordóñez González, José Genaro; Thirion, Jaime; García Orozco, Abel; Rodríguez, Américo D

    2011-06-01

    Indoor ultra-low volume (ULV) applications of Aqua Reslin Super (Permethrin + s-bioallethrin) were carried out using portable Solo Port 423 sprayers in an urban area of Reforma, Chiapas, Mexico. Sprayers were calibrated to discharge a flow rate of 110 ml/min with a dose range of approximately 0.55 to 0.792 mg Al/m3 space. Entomological evaluation, based on 3 cages per house, each containing 15 sugar-fed, 2-4-day-old Aedes aegypti females and placed in hidden locations in 4 randomly selected houses for 15 min, showed 98.8% to 100% mortality. After the spraying, ovitrap data showed no mosquito adults present 4 days after the applications, and only 1 ovitrap out of 60 positive 8 days after the intervention. This evaluation suggests that indoor ULV application can be useful during emergencies after disasters, during dengue outbreaks, or to prevent mosquito population outbreaks before rainy seasons and, therefore, the onset of dengue transmission in Mexican dengue transmission risk areas.

  15. Impact of image denoising on image quality, quantitative parameters and sensitivity of ultra-low-dose volume perfusion CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Brockmann, Carolin; Afat, Saif; Pjontek, Rastislav; Nikoubashman, Omid; Brockmann, Marc A.; Wiesmann, Martin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Yang, Zepa; Kim, Changwon [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Nikolaou, Konstantin [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Kim, Jong Hyo [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Advanced Institute of Convergence Technology, Center for Medical-IT Convergence Technology Research, Suwon (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of)

    2016-01-15

    To examine the impact of denoising on ultra-low-dose volume perfusion CT (ULD-VPCT) imaging in acute stroke. Simulated ULD-VPCT data sets at 20 % dose rate were generated from perfusion data sets of 20 patients with suspected ischemic stroke acquired at 80 kVp/180 mAs. Four data sets were generated from each ULD-VPCT data set: not-denoised (ND); denoised using spatiotemporal filter (D1); denoised using quanta-stream diffusion technique (D2); combination of both methods (D1 + D2). Signal-to-noise ratio (SNR) was measured in the resulting 100 data sets. Image quality, presence/absence of ischemic lesions, CBV and CBF scores according to a modified ASPECTS score were assessed by two blinded readers. SNR and qualitative scores were highest for D1 + D2 and lowest for ND (all p ≤ 0.001). In 25 % of the patients, ND maps were not assessable and therefore excluded from further analyses. Compared to original data sets, in D2 and D1 + D2, readers correctly identified all patients with ischemic lesions (sensitivity 1.0, kappa 1.0). Lesion size was most accurately estimated for D1 + D2 with a sensitivity of 1.0 (CBV) and 0.94 (CBF) and an inter-rater agreement of 1.0 and 0.92, respectively. An appropriate combination of denoising techniques applied in ULD-VPCT produces diagnostically sufficient perfusion maps at substantially reduced dose rates as low as 20 % of the normal scan. (orig.)

  16. Maglev Launch: Ultra-low Cost, Ultra-high Volume Access to Space for Cargo and Humans

    Science.gov (United States)

    Powell, James; Maise, George; Rather, John

    2010-01-01

    Despite decades of efforts to reduce rocket launch costs, improvements are marginal. Launch cost to LEO for cargo is ~$10,000 per kg of payload, and to higher orbit and beyond much greater. Human access to the ISS costs $20 million for a single passenger. Unless launch costs are greatly reduced, large scale commercial use and human exploration of the solar system will not occur. A new approach for ultra low cost access to space-Maglev Launch-magnetically accelerates levitated spacecraft to orbital speeds, 8 km/sec or more, in evacuated tunnels on the surface, using Maglev technology like that operating in Japan for high speed passenger transport. The cost of electric energy to reach orbital speed is less than $1 per kilogram of payload. Two Maglev launch systems are described, the Gen-1System for unmanned cargo craft to orbit and Gen-2, for large-scale access of human to space. Magnetically levitated and propelled Gen-1 cargo craft accelerate in a 100 kilometer long evacuated tunnel, entering the atmosphere at the tunnel exit, which is located in high altitude terrain (~5000 meters) through an electrically powered ``MHD Window'' that prevents outside air from flowing into the tunnel. The Gen-1 cargo craft then coasts upwards to space where a small rocket burn, ~0.5 km/sec establishes, the final orbit. The Gen-1 reference design launches a 40 ton, 2 meter diameter spacecraft with 35 tons of payload. At 12 launches per day, a single Gen-1 facility could launch 150,000 tons annually. Using present costs for tunneling, superconductors, cryogenic equipment, materials, etc., the projected construction cost for the Gen-1 facility is 20 billion dollars. Amortization cost, plus Spacecraft and O&M costs, total $43 per kg of payload. For polar orbit launches, sites exist in Alaska, Russia, and China. For equatorial orbit launches, sites exist in the Andes and Africa. With funding, the Gen-1 system could operate by 2020 AD. The Gen-2 system requires more advanced technology

  17. Mosquito Management on National Wildlife Refuges, Ecosystem Effects Study. Phase II, Part 1 - Effects of Ultra Low Volume Applications of Pyrethrin, Malathion and Permethrin on Macro-Invertebrates in the Sacramento National Wildlife Refuge, California

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Mosquito control districts often use ultra-low volume (ULV) applications of insecticides to control adult mosquitoes. Few field studies have tested the effects of...

  18. Propagation of interplanetary shock excited ultra low frequency (ULF) waves in magnetosphere-ionosphere-atmosphere——Multi-spacecraft “Cluster” and ground-based magnetometer observations

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The ultra low frequency (ULF) wave in magnetosphere can act as an important means for solar wind energy inward transmission.This paper quantitatively analyzes the propagation process of the ULF wave triggered by the interplanetary shock propagating from inner magnetosphere equatorial plane along magnetic field lines to the top of the ionosphere and below ionosphere propagating process and establishes a relatively complete magnetosphere-ionosphere-atmosphere propagation model which can be used to study the relationship between the amplitude of the ULF waves triggered by the interplanetary shock wave in magnetospheric space and the magnetic effect caused by the ULF waves.After a comparison with recent observations,we found that: in the event during November 7,2004 that an interplanetary shock wave interacted with the magnetosphere,Cluster satellites observed that electric field fluctuations and the band-pass filtered result of ground stations meridional component had similar characteristics.Comparing with the geomagnetic measurement near the footprints,we found that the electric field disturbance in the magnetosphere spread along the ground magnetic field lines in the form of the ULF waves and changed into geomagnetic disturbance.The result reveals that the ULF wave is in contact with the ground geomagnetic observation.The ULF waves couple with ionized components in ionosphere and spread to the ground in the form of electromagnetic waves.In this research,we believe that the magnetosphere,ionosphere and ground magnetic effects caused by interplanetary shock wave are the same physical phenomena responding in different locations.Based on the overall consideration of entire electromagnetic response to the interplanetary shock wave,we found that the correlation between CLUSTER multi-satellite observation and geomagnetic station observation is due to the ULF wave propagated in magnetosphere-ionosphere-atmosphere system,and we quantitatively interpreted this response

  19. Comparison of an ultra-low volume (ULV sprayer against a conventional sprayer, for foliar fertiliser and fungicide applications in turfgrass

    Directory of Open Access Journals (Sweden)

    Ferguson Jason Connor

    2016-01-01

    Full Text Available Two field studies (I and II at the University of Nebraska-Lincoln: John Seaton Anderson Turfgrass Research Facility near Mead, NE, USA, were conducted to determine if a new ultra-low volume (ULV sprayer can apply foliar nutrient, growth regulator, and fungicide treatments, in a manner similar to that of a conventional sprayer. Treatments were applied over creeping bentgrass ‘L-93’ (Agrostis stolonifera L. managed as a fairway at 561 l · ha−1 and 47 l · ha−1 with the conventional and ULV sprayer, respectfully. Data were collected for chlorophyll content with a chlorophyll meter, and for the normalised difference vegetation index (NDVI with a turf colour meter. Each plot was harvested for biomass at 21 days after treatment. Study II compared the ULV sprayer and a conventional sprayer, for the control of brown patch (Rhizoctonia solani Kuhn in creeping bentgrass. The treatments were propiconazole and azoxystrobin. Spray volume was 561 l · ha−1 for the conventional sprayer, and 19 l · ha−1 for the ULV sprayer. Statistical differences in turf quality or dry weight reductions between the conventional and ULV sprayer were not detected. Brown patch control was also similar between the two sprayers, but azoxystrobin provided better control than propiconazole. Even with a 30-fold decrease in application volume, the results indicated that the Kamterter ULV sprayer may be a useful and effective management option for foliar fertiliser and fungicide applications in turfgrass.

  20. Effectiveness of ultra-low volume nighttime applications of an adulticide against diurnal Aedes albopictus, a critical vector of dengue and chikungunya viruses.

    Directory of Open Access Journals (Sweden)

    Ary Farajollahi

    Full Text Available Aedes albopictus, the Asian tiger mosquito, continues expanding its geographic range and involvement in mosquito-borne diseases such as chikungunya and dengue. Vector control programs rarely attempt to suppress this diurnal species with an ultra-low volume (ULV adulticide because for maximum efficacy applications are conducted at night. During 2009-2011 we performed experimental nighttime applications of a novel adulticide (DUET® against field populations of Ae. albopictus within an urban site composed of approximately 1,000 parcels (home and yard in northeastern USA. Dual applications at mid label rate of the adulticide spaced one or two days apart accomplished significantly higher control (85.0 ± 5.4% average reduction than single full rate applications (73.0 ± 5.4%. Our results demonstrate that nighttime ULV adulticiding is effective in reducing Ae. albopictus abundance and highlight its potential for use as part of integrated pest management programs and during disease epidemics when reducing human illness is of paramount importance.

  1. Versatile, ultra-low sample volume gas analyzer using a rapid, broad-tuning ECQCL and a hollow fiber gas cell

    Energy Technology Data Exchange (ETDEWEB)

    Kriesel, Jason M.; Makarem, Camille N.; Phillips, Mark C.; Moran, James J.; Coleman, Max; Christensen, Lance; Kelly, James F.

    2017-05-05

    We describe a versatile mid-infrared (Mid-IR) spectroscopy system developed to measure the concentration of a wide range of gases with an ultra-low sample size. The system combines a rapidly-swept external cavity quantum cascade laser (ECQCL) with a hollow fiber gas cell. The ECQCL has sufficient spectral resolution and reproducibility to measure gases with narrow features (e.g., water, methane, ammonia, etc.), and also the spectral tuning range needed to measure volatile organic compounds (VOCs), (e.g., aldehydes, ketones, hydrocarbons), sulfur compounds, chlorine compounds, etc. The hollow fiber is a capillary tube having an internal reflective coating optimized for transmitting the Mid-IR laser beam to a detector. Sample gas introduced into the fiber (e.g., internal volume = 0.6 ml) interacts strongly with the laser beam, and despite relatively modest path lengths (e.g., L ~ 3 m), the requisite quantity of sample needed for sensitive measurements can be significantly less than what is required using conventional IR laser spectroscopy systems. Example measurements are presented including quantification of VOCs relevant for human breath analysis with a sensitivity of ~2 picomoles at a 1 Hz data rate.

  2. Nanoprobe NAPPA Arrays for the Nanoconductimetric Analysis of Ultra-Low-Volume Protein Samples Using Piezoelectric Liquid Dispensing Technology

    Directory of Open Access Journals (Sweden)

    Eugenia Pechkova

    2015-03-01

    Full Text Available In the last years, the evolution and the advances of the nanobiotechnologies applied to the systematic study of proteins, namely proteomics, both structural and functional, and specifically the development of more sophisticated and largescale protein arrays, have enabled scientists to investigate protein interactions and functions with an unforeseeable precision and wealth of details. Here, we present a further advancement of our previously introduced and described Nucleic Acid Programmable Protein Arrays (NAPPA-based nanoconductometric sensor. We coupled Quartz Crystal Microbalance with Dissipation factor Monitoring (QCM_D with piezoelectric inkjet printing technology (namely, the newly developed ActivePipette, which enables to significantly reduce the volume of probe required for genes/proteins arrays. We performed a negative control (with master mix, or MM and a positive control (MM_p53 plus MDM2. We performed this experiment both in static and in flow, computing the apparent dissociation constant of p53-MDM2 complex (130 nM, in excellent agreement with the published literature. We compared the results obtained with the ActivePipette printing and dispensing technology vs. pin spotting. Without the ActivePipette, after MDM2 addition the shift in frequency (Δf was 7575 Hz and the corresponding adsorbed mass was 32.9 μg. With the ActivePipette technology, after MDM2 addition Δf was 7740 Hz and the corresponding adsorbed mass was 33.6 μg. With this experiment, we confirmed the sensing potential of our device, being able to discriminate each gene and protein as well as their interactions, showing for each one of them a unique conductance curve. Moreover, we obtained a better yield with the ActivePipette technology.

  3. Droplet sampling of an oil-based and two water-based antievaporant ultra-low volume insecticide formulations using Teflon- and magnesium oxide-coated slides.

    Science.gov (United States)

    Chaskopoulou, Alexandra; Latham, Mark D; Pereira, Roberto M; Koehler, Philip G

    2013-06-01

    We estimated the diameters below which 50% and 90% of the volume of droplets exist (Dv50 and Dv90, respectively) of 1 oil-based (Permanone 30-30) and 2 water-based (AquaReslin, Aqua-K-Othrine) antievaporant aerosols (with the Film Forming Aqueous Spray Technology [FFAST]) using Teflon- and magnesium oxide (MgO)-coated slides and determined whether the aging of the droplets on the slides (up to 60 min) exhibited any significant effect on Dv50 and Dv90 calculations. There were no significant differences in either Dv50 or Dv90 estimates on MgO-coated slides at 0 min and 60 min for all 3 products tested. On Teflon-coated slides, the only product that showed significant difference between 0 min and 60 min in both Dv50 and Dv90 estimates was Aqua-K-Othrine, perhaps due to a difference in formulation components. Specifically, both values corresponding to Dv50 and Dv90 at 60 min decreased by approximately 50% when compared to the values at 0 min. For the other 2 products, AquaReslin and Permanone, aging of droplets on Teflon up to 60 min did not have any significant effect on Dv50 and Dv90 values. To further investigate the behavior of Aqua-K-Othrine droplets on Teflon-coated slides we observed the droplets immediately after spraying and at 10-min intervals under different conditions of temperature and humidity. The majority of the shrinkage occurred within the 1st 10 min after impaction on the slides under all conditions tested. So in most field situations where slides are read several hours or days after collection, this shrinkage would not be observed. The MgO-coated slides should be the preferred field method for sampling droplets of Aqua-K-Othirne with the FFAST antievaporant technology.

  4. PROMIS series. Volume 8: Midlatitude ground magnetograms

    Science.gov (United States)

    Fairfield, D. H.; Russell, C. T.

    1990-01-01

    This is the eighth in a series of volumes pertaining to the Polar Region Outer Magnetosphere International Study (PROMIS). This volume contains 24 hour stack plots of 1-minute average, H and D component, ground magnetograms for the period March 10 through June 16, 1986. Nine midlatitude ground stations were selected from the UCLA magnetogram data base that was constructed from all available digitized magnetogram stations. The primary purpose of this publication is to allow users to define universal times and onset longitudes of magnetospheric substorms.

  5. Nucleation in an ultra low ionisation environment

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

    In this work we have studied aerosol formation at ultra-low ionisation levels, using the existing deep underground science facility at Boulby mine, UK. At 1100 m depth, with a corresponding factor 106 reduction in cosmic ray muon flux, the Boulby facility is an ideal place to study the role of ions...

  6. Ultra low power full adder topologies

    DEFF Research Database (Denmark)

    Moradi, Farshad; Wisland, Dag T.; Mahmoodi, Hamid

    In this paper several low power full adder topologies are presented. The main idea of these circuits is based on the sense energy recovery full adder (SERF) design and the GDI (gate diffusion input) technique. These subthreshold circuits are employed for ultra low power applications. While...

  7. Ultra low bit-rate speech coding

    CERN Document Server

    Ramasubramanian, V

    2015-01-01

    "Ultra Low Bit-Rate Speech Coding" focuses on the specialized topic of speech coding at very low bit-rates of 1 Kbits/sec and less, particularly at the lower ends of this range, down to 100 bps. The authors set forth the fundamental results and trends that form the basis for such ultra low bit-rates to be viable and provide a comprehensive overview of various techniques and systems in literature to date, with particular attention to their work in the paradigm of unit-selection based segment quantization. The book is for research students, academic faculty and researchers, and industry practitioners in the areas of speech processing and speech coding.

  8. Uranium in US surface, ground, and domestic waters. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Drury, J.S.; Reynolds, S.; Owen, P.T.; Ross, R.H.; Ensminger, J.T.

    1981-04-01

    The report Uranium in US Surface, Ground, and Domestic Waters comprises four volumes. Volumes 2, 3, and 4 contain data characterizing the location, sampling date, type, use, and uranium conentrations of 89,994 individual samples presented in tabular form. The tabular data in volumes 2, 3, and 4 are summarized in volume 1 in narrative form and with maps and histograms.

  9. Ultra-low temperature MAS-DNP

    Science.gov (United States)

    Lee, Daniel; Bouleau, Eric; Saint-Bonnet, Pierre; Hediger, Sabine; De Paëpe, Gaël

    2016-03-01

    Since the infancy of NMR spectroscopy, sensitivity and resolution have been the limiting factors of the technique. Regular essential developments on this front have led to the widely applicable, versatile, and powerful spectroscopy that we know today. However, the Holy Grail of ultimate sensitivity and resolution is not yet reached, and technical improvements are still ongoing. Hence, high-field dynamic nuclear polarization (DNP) making use of high-frequency, high-power microwave irradiation of electron spins has become very promising in combination with magic angle sample spinning (MAS) solid-state NMR experiments. This is because it leads to a transfer of the much larger polarization of these electron spins under suitable irradiation to surrounding nuclei, greatly increasing NMR sensitivity. Currently, this boom in MAS-DNP is mainly performed at minimum sample temperatures of about 100 K, using cold nitrogen gas to pneumatically spin and cool the sample. This Perspective deals with the desire to improve further the sensitivity and resolution by providing "ultra"-low temperatures for MAS-DNP, using cryogenic helium gas. Different designs on how this technological challenge has been overcome are described. It is shown that stable and fast spinning can be attained for sample temperatures down to 30 K using a large cryostat developed in our laboratory. Using this cryostat to cool a closed-loop of helium gas brings the additional advantage of sample spinning frequencies that can greatly surpass those achievable with nitrogen gas, due to the differing fluidic properties of these two gases. It is shown that using ultra-low temperatures for MAS-DNP results in substantial experimental sensitivity enhancements and according time-savings. Access to this temperature range is demonstrated to be both viable and highly pertinent.

  10. Balloon observations of ultra-low-frequency waves in the electric field above the South Pole

    Energy Technology Data Exchange (ETDEWEB)

    Liao, B.; Benbrrook, J.R.; Bering E.A. III; Byrne, G.J.; Theall, J.R. (Univ. of Houston, TX (USA))

    1988-01-01

    The physics of ultra-low-frequency waves in the magnetosphere, near the cusp and in the polar cap, is important because this region is one where ultra-low-frequency wave energy from the magnetopause can most easily enter the magnetosphere. During the 1985-1986 South Pole balloon campaign, eight stratospheric balloon payloads were launched from Amundsen-Scott Station, South Geographic Pole, Antarctica, to record data on ultra-low-frequency waves. The payloads were instrumented with three-axis double-probe electric field detectors and X-ray scintillation counters. This paper concentrates on the third flight of this series, which was launched at 2205 universal time on 21 December 1985. Good data were received from the payload until the transmitter failed at 0342 universal time on 22 December. During most of the four hours that the balloon was afloat, an intense ultra-low-frequency wave event was in progress. The electric-field data from this period have been examined in detail and compared with magnetic field data, obtained with ground-based fluxgate and induction magnetometers to determine the characteristics of the waves. After float was reached, the electric-field data in figure 1 show large-amplitude, quasi-periodic fluctuations suggesting the presence of intense ultra-low-frequency wave activity. In conclusion, the electric-field signature observed from flight 3 appears to have been essentially an electrostatic event or possibly a short-wavelength hydromagnetic wave with a varying and interesting polarization character. The authors are continuing the analysis of the data to determine the source of the observed ultra-low-frequency waves.

  11. Endometrial safety of ultra-low-dose estradiol vaginal tablets

    DEFF Research Database (Denmark)

    Simon, James; Nachtigall, Lila; Ulrich, Lian G;

    2010-01-01

    To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17ß-estradiol vaginal tablets in postmenopausal women with vaginal atrophy.......To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17ß-estradiol vaginal tablets in postmenopausal women with vaginal atrophy....

  12. Endometrial safety of ultra-low-dose estradiol vaginal tablets

    DEFF Research Database (Denmark)

    Simon, James; Nachtigall, Lila; Ulrich, Lian G;

    2010-01-01

    To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17β-estradiol vaginal tablets in postmenopausal women with vaginal atrophy.......To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17β-estradiol vaginal tablets in postmenopausal women with vaginal atrophy....

  13. Ultra-Low-Density (ULD) Polymer Matrix Composites (PMCs) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA Phase I SBIR proposal seeks to demonstrate a new class of ultra-low-density (ULD) polymer matrix composites of high specific modulus and specific strength...

  14. Thin films with ultra-low thermal expansion.

    Science.gov (United States)

    Yamamoto, Namiko; Gdoutos, Eleftherios; Toda, Risaku; White, Victor; Manohara, Harish; Daraio, Chiara

    2014-05-21

    Ultra-low coefficient of thermal expansion (CTE) is an elusive property, and narrow temperature ranges of operation and poor mechanical properties limit the use of conventional materials with low CTE. We structured a periodic micro-array of bi-metallic cells to demonstrate ultra-low effective CTE with a wide temperature range. These engineered tunable CTE thin film can be applied to minimize thermal fatigue and failure of optics, semiconductors, biomedical sensors, and solar energy applications.

  15. The Aneutronic Rodless Ultra Low Aspect Ratio Tokamak

    Science.gov (United States)

    Ribeiro, Celso

    2016-10-01

    The replacement of the metal centre-post in spherical tokamaks (STs) by a plasma centre-post (PCP, the TF current carrier) is the ideal scenario for a ST reactor. A simple rodless ultra low aspect-ratio tokamak (RULART) using a screw-pinch PCP ECR-assisted with an external solenoid has been proposed in the most compact RULART [Ribeiro C, SOFE-15]. There the solenoid provided the stabilizing field for the PCP and the toroidal electrical field for the tokamak start-up, which will stabilize further the PCP, acting as stabilizing closed conducting surface. Relative low TF will be required. The compactness (high ratio of plasma-spherical vessel volume) may provide passive stabilization and easier access to L-H mode transition. It is presented here: 1) stability analysis of the PCP (initially MHD stable due to the hollow J profile); 2) tokamak equilibrium simulations, and 3) potential use for aneutronic reactions studies via pairs of proton p and boron 11B ion beams in He plasmas. The beams' line-of-sights sufficiently miss the sources of each other, thus allowing a near maximum relative velocities and reactivity. The reactions should occur close to the PCP mid-plane. Some born alphas should cross the PCP and be dragged by the ion flow (higher momentum exchange) towards the anode but escape directly to a direct electricity converter. Others will reach evenly the vessel directly or via thermal diffusion (favourable heating by the large excursion 2a), leading to the lowest power wall load possible. This might be a potential hybrid direct-steam cycle conversion reactor scheme, nearly aneutronic, and with no ash or particle retention problems, as opposed to the D-T thermal reaction proposals.

  16. Ultra Low Loss Optical Fiber Cable Assemblies. Volume 2.

    Science.gov (United States)

    1983-06-07

    attenuation of each cabled fiber is calculated per paragraph 3.1.4. 4.4.5 TESi RESULTS REPORTING The pre test and post test attenuation of each cabled fiber...lg oss of a za:ad pAi: of~~~~~~~~~~~~ coe~r o ±s ;o asma -c~Ln: f cable anda)1khaa :ocaptacla -!5 . imUvab1. gtbers seda.4 crod n .2..) ~"be deaa= on

  17. Ultra-Low Voltage Class AB Switched Current Memory Cell

    DEFF Research Database (Denmark)

    Igor, Mucha

    1996-01-01

    This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process with thr......This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process...

  18. A Multicounter System for Scanning Ultra-Low-Level Radiochromatograms

    DEFF Research Database (Denmark)

    Bøtter-Jensen, Lars; Hansen, Heinz Johs. Max; Theodorsson, P.

    1977-01-01

    A multicounter system consisting of an integrated array of flow counters for the scanning of ultra-low-level radioactivity on paper and thin-layer chromatograms was developed. Experience with routine measurements over a prolonged period has proved the advantages of this system over other systems...

  19. CMOS Ultra Low Power Radiation Tolerant (CULPRiT) Microelectronics

    Science.gov (United States)

    Yeh, Penshu; Maki, Gary

    2007-01-01

    Space Electronics needs Radiation Tolerance or hardness to withstand the harsh space environment: high-energy particles can change the state of the electronics or puncture transistors making them disfunctional. This viewgraph document reviews the use of CMOS Ultra Low Power Radiation Tolerant circuits for NASA's electronic requirements.

  20. FORMULATING ULTRA-LOW-VOC WOOD FURNITURE COATINGS

    Science.gov (United States)

    The article discusses the formulation of ultra-low volatile organic compound (VOC) wood furniture coatings. The annual U.S. market for wood coatings is about 240, 000 cu m (63 million gal). In this basis, between 57 and 91 million kg (125 and 200 million lb) of VOCs are emitted i...

  1. Reaching ultra low phosphorus concentrations by filtration techniques

    NARCIS (Netherlands)

    Scherrenberg, S.M.

    2011-01-01

    This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (<0.15 mg total phosphorus/L) concentrations by coagulation, flocculation and filtrat

  2. Reaching ultra low phosphorus concentrations by filtration techniques

    NARCIS (Netherlands)

    Scherrenberg, S.M.

    2011-01-01

    This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (<0.15 mg total phosphorus/L) concentrations by coagulation, flocculation and

  3. Ultra-low birefringence dodecagonal vacuum glass cell

    CERN Document Server

    Brakhane, Stefan; Meschede, Dieter; Moon, Geol; Robens, Carsten; Alberti, Andrea

    2015-01-01

    We eport on an ultra-low birefringence dodecagonal glass cell for ultra-high vacuum applications. The epoxy-bonded trapezoidal windows of the cell are made of SF57 glass, which exhibits a very low stress-induced birefringence. We characterize the birefringence $\\Delta n$ of each window with the cell under vacuum conditions, obtaining values around $\

  4. Nucleation in an Ultra Low Ionization Environment

    Science.gov (United States)

    Pedersen, J. O.; Enghoff, M. B.; Paling, S.; Svensmark, H.

    2010-12-01

    Atmospheric ions can enhance the nucleation of aerosols, as has been established by experiments, observation, and theory. In the clean marine atmosphere ionization is mainly caused by cosmic rays which in turn are controlled by the activity of the Sun, thus providing a potential link between solar activity and climate. In order to understand the effect ions may have on the production of cloud condensation nuclei the overall contribution of ion induced nucleation to the global production of secondary aerosols must be determined. One issue with determining this contribution is that several mechanisms for nucleation exist and it can be difficult to determine the relative importance of the various mechanisms in a given nucleation event when both ion induced and electrically neutral nucleation mechanisms are at work at the same time. We have carried out nucleation experiments in the Boulby Underground Laboratory, located 1100 meters below ground, thus reducing the flux of ionizing cosmic radiation by six orders of magnitude. Similarly we have reduced the gamma background by shielding the experiment in lead and copper. Finally we have used air stored for several weeks and passed through an active charcoal filter in order to reduce the Radon concentration. In this way we have been able to make nucleation experiments with very low ionizing background, meaning that we can rule out ion induced nucleation as a contributing mechanism. Our experimental setup is a 50 L electropolished stainless steel reactor at near atmospheric conditions. The chamber contains clean air with the addition of water vapor, ozone, and SO2. Using UV lights at 254 nm ozone is photolyzed, leading to the production of sulfuric acid and thus aerosols. An 18 MBq Caesium-137 gamma ray source with various amounts of lead in front allows us to alter the ionization in our chamber. By making series of nucleation bursts with varying amounts of ionizing radiation we then gauge the relative importance of ion

  5. Ultra-Low Voltage Class AB Switched Current Memory Cell

    DEFF Research Database (Denmark)

    Igor, Mucha

    1996-01-01

    This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process with thr......This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process...... with threshold voltages of 0.9V. Both hand calculations and PSPICE simulations showed that the cells designed allowed a maximum signal range better than +/-13 micoamp, with a supply voltage down to 1V and a quiescent bias current of 1 microamp, resulting in a very high current efficiency and effective power...

  6. Design of ultra-low power impulse radios

    CERN Document Server

    Apsel, Alyssa; Dokania, Rajeev

    2014-01-01

    This book covers the fundamental principles behind the design of ultra-low power radios and how they can form networks to facilitate a variety of applications within healthcare and environmental monitoring, since they may operate for years off a small battery or even harvest energy from the environment. These radios are distinct from conventional radios in that they must operate with very constrained resources and low overhead.  This book provides a thorough discussion of the challenges associated with designing radios with such constrained resources, as well as fundamental design concepts and practical approaches to implementing working designs.  Coverage includes integrated circuit design, timing and control considerations, fundamental theory behind low power and time domain operation, and network/communication protocol considerations.   • Enables detailed understanding of the design space for ultra-low power radio; • Provides detailed discussion and examples of the design of a practical low power ...

  7. Oxidation of ultra low carbon and silicon bearing steels

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Lucia [CTM - Technologic Centre, Materials Technology Area, Manresa, Barcelona (Spain)], E-mail: lucia.suarez@ctm.com.es; Rodriguez-Calvillo, Pablo [CTM - Technologic Centre, Materials Technology Area, Manresa, Barcelona (Spain)], E-mail: pablo.rodriguez@ctm.com.es; Houbaert, Yvan [Department of Materials Science and Engineering, University of Ghent (Belgium)], E-mail: Yvan.Houbaert@UGent.be; Colas, Rafael [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico)], E-mail: rcolas@mail.uanl.mx

    2010-06-15

    Oxidation tests were carried out in samples from an ultra low carbon and two silicon bearing steels to determine the distribution and morphology of the oxide species present. The ultra low carbon steel was oxidized for short periods of time within a chamber designed to obtain thin oxide layers by controlling the atmosphere, and for longer times in an electric furnace; the silicon steels were reheated only in the electric furnace. The chamber was constructed to study the behaviour encountered during the short period of time between descaling and rolling in modern continuous mills. It was found that the oxide layers formed on the samples reheated in the electric furnace were made of different oxide species. The specimens treated in the chamber had layers made almost exclusively of wustite. Selected oxide samples were studied by scanning electron microscopy to obtain electron backscattered diffraction patterns, which were used to identify the oxide species in the layer.

  8. ATF2 Ultra-Low IP Betas Proposal

    CERN Document Server

    Bambade, P; Bai, S; Braun, H; Delahaye, J P; Marin, E; Schulte, D; Tomás, R; Zimmermann, F; Gao, J; Wang, D; Zhu, XW; Honda, Y; Kuroda, S; Okugi, T; Tauchi, T; Terunuma, N; Urakawa, J; Seryi, A; White, G; Woodley, M; Angal-Kalinin, D; Jones, J; Scarfe, A

    2010-01-01

    The CLIC Final Focus System has considerably larger chromaticity than those of ILC and its scaled test machine ATF2. We propose to reduce the IP betas of ATF2 to reach a CLIC-like chromaticity. This would also allow to study the FFS tuning difficulty as function of the IP beam spot size. Both the ILC and CLIC projects will largely benefit from the ATF2 experience at these ultra-low IP betas.

  9. Study of ultra-low emittance design for SPEAR3

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M. -H.; Huang, X.; Safranek, J.; /SLAC

    2015-09-17

    Since its 2003 construction, the SPEAR3 synchrotron light source at SLAC has continuously improved its performance by raising beam current, top-off injection, and smaller emittance. This makes SPEAR3 one of the most productive light sources in the world. Now, to further enhance the performance of SPEAR3, we are looking into the possibility of converting SPEAR3 to an ultra-low emittance storage ring within its site constraint.

  10. Ultra-low frequency shock dynamics in degenerate relativistic plasmas

    Science.gov (United States)

    Islam, S.; Sultana, S.; Mamun, A. A.

    2017-09-01

    A degenerate relativistic three-component plasma model is proposed for ultra-low frequency shock dynamics. A reductive perturbation technique is adopted, leading to Burgers' nonlinear partial differential equation. The properties of the shock waves are analyzed via the stationary shock wave solution for different plasma configuration parameters. The role of different intrinsic plasma parameters, especially the relativistic effects on the linear wave properties and also on the shock dynamics, is briefly discussed.

  11. Ultra-Low-Power MEMS Selective Gas Sensors

    Science.gov (United States)

    Stetter, Joseph

    2012-01-01

    This innovation is a system for gas sensing that includes an ultra-low-power MEMS (microelectromechanical system) gas sensor, combined with unique electronic circuitry and a proprietary algorithm for operating the sensor. The electronics were created from scratch, and represent a novel design capable of low-power operation of the proprietary MEMS gas sensor platform. The algorithm is used to identify a specific target gas in a gas mixture, making the sensor selective to that target gas.

  12. Ultra low power transceiver for wireless body area networks

    CERN Document Server

    Masuch, Jens

    2013-01-01

    This book describes the design of ultra low power transceivers for body area networks.  Since these applications have very limited energy resources, typically powered only by tiny batteries or through energy harvesting techniques, this book describes an architecture for a Bluetooth low energy transceiver to overcome these limitations. Coverage includes not only the main concepts for achieving low power consumption, but also the details of the circuit design and its implementation in a standard CMOS technology.     ·         Guides readers through the design of ultra low power transceivers for body area networks, from architecture to circuit-level implementation; ·         Describes 4 key strategies for ultra-low power transceiver design and specific, innovative techniques for circuit-level design; ·         Enables readers to design transceivers for body area networks that are 27% more energy efficient than those currently available; ·         Includes a review of the st...

  13. Ultra-low-power and ultra-low-cost short-range wireless receivers in nanoscale CMOS

    CERN Document Server

    Lin, Zhicheng; Martins, Rui Paulo

    2016-01-01

    This book provides readers with a description of state-of-the-art techniques to be used for ultra-low-power (ULP) and ultra-low-cost (ULC), short-range wireless receivers. Readers will learn what is required to deploy these receivers in short-range wireless sensor networks, which are proliferating widely to serve the internet of things (IoT) for “smart cities.” The authors address key challenges involved with the technology and the typical tradeoffs between ULP and ULC. Three design examples with advanced circuit techniques are described in order to address these trade-offs, which specially focus on cost minimization. These three techniques enable respectively, cascading of radio frequency (RF) and baseband (BB) circuits under an ultra-low-voltage (ULV) supply, cascoding of RF and BB circuits in current domain for current reuse, and a novel function-reuse receiver architecture, suitable for ULV and multi-band ULP applications such as the sub-GHz ZigBee. ·         Summarizes the state-of-the-art i...

  14. Note: Ultra-low birefringence dodecagonal vacuum glass cell

    Energy Technology Data Exchange (ETDEWEB)

    Brakhane, Stefan, E-mail: brakhane@iap.uni-bonn.de; Alt, Wolfgang; Meschede, Dieter; Robens, Carsten; Moon, Geol; Alberti, Andrea [Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, D-53115 Bonn (Germany)

    2015-12-15

    We report on an ultra-low birefringence dodecagonal glass cell for ultra-high vacuum applications. The epoxy-bonded trapezoidal windows of the cell are made of SF57 glass, which exhibits a very low stress-induced birefringence. We characterize the birefringence Δn of each window with the cell under vacuum conditions, obtaining values around 10{sup −8}. After baking the cell at 150 °C, we reach a pressure below 10{sup −10} mbar. In addition, each window is antireflection coated on both sides, which is highly desirable for quantum optics experiments and precision measurements.

  15. Ultra low frequency waves impact on radiation belt energetic particles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    One of the most fundamental important issues in the space physics is to understand how solar wind energy transports into the inner magnetosphere.Ultra low frequency(ULF)wave in the magnetosphere and its impact on energetic particles,such as the wave-particle resonance,modulation,and particle acceleration,are extremely important topics in the Earth’s radiation belt dynamics and solar wind― magnetospheric coupling.In this review,we briefly introduce the recent advances on ULF waves study. Further,we will explore the density structures and ion compositions around the plasmaspheric boundary layer(PBL)and discuss its possible relation to the ULF waves.

  16. Ultra low frequency waves impact on radiation belt energetic particles

    Institute of Scientific and Technical Information of China (English)

    ZONG QiuGang; HAO YongQiang; WANG YongFu

    2009-01-01

    One of the most fundamental important issues in the space physics is to understand how solar wind energy transports into the inner magnetosphere.Ultra low frequency(ULF)wave in the magnetosphere and its impact on energetic particles,such as the wave-particle resonance,modulation,and particle acceleration,are extremely important topics in the Earth's radiation belt dynamics and solar windmagnetospheric coupling.In this review,we briefly introduce the recent advances on ULF waves study.Further,we will explore the density structures and ion compositions around the plasmaspheric boundary layer(PBL)and discuss its possible relation to the ULF waves.

  17. A programmable ultra-low noise X-band exciter.

    Science.gov (United States)

    MacMullen, A; Hoover, L R; Justice, R D; Callahan, B S

    2001-07-01

    A programmable ultra-low noise X-band exciter has been developed using commercial off-the-shelf components. Its phase noise is more than 10 dB below the best available microwave synthesizers. It covers a 7% frequency band with 0.1-Hz resolution. The X-band output at +23 dBm is a combination of signals from an X-band sapphire-loaded cavity oscillator (SLCO), a low noise UHF frequency synthesizer, and special-purpose frequency translation and up-conversion circuitry.

  18. Research of Mold Powder for Ultra-Low Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper explained the mechanism of carbon pickup byultra-low-carbon steels during continuous casting and indicated that the major cause of carbon pickup is the contact of the molten steel with the enriched-carbon layer of the powder. Forming of the enriched-carbon layer is due to the existing of “carbon core”. Accordingly, the measures to reduce the carbon content and amount of the enriched-carbon layer were investigated. A kind of new powder has been developed and successfully used to minimize the carbon pickup by ultra-low carbon steels during continuous casting.

  19. Hannover fare[Ultra low energy flats in Hannover, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Bellew, P.; Kauschmann, J. [Atelier Ten (Germany)

    2000-08-01

    This article describes the new ultra-low energy apartments established for Expo 2000 in the Kronsberg residential district on the outskirts of Hannover. Details are given of the concept design placing the blocks back to back and separating them by a covered atrium, the connection of the eight blocks to a mechanical ventilation system with heat recovery, and the unusual 3-skin roof structure with different cavities inflated in winter and summer. The heating and hot water system, the metering of the apartments, and the regulatory framework governing the construction of the buildings are discussed.

  20. GRABGAM Analysis of Ultra-Low-Level HPGe Gamma Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.

    1999-07-28

    The GRABGAM code has been used successfully for ultra-low level HPGe gamma spectrometry analysis since its development in 1985 at Savannah River Technology Center (SRTC). Although numerous gamma analysis codes existed at that time, reviews of institutional and commercial codes indicated that none addressed all features that were desired by SRTC. Furthermore, it was recognized that development of an in-house code would better facilitate future evolution of the code to address SRTC needs based on experience with low-level spectra. GRABGAM derives its name from Gamma Ray Analysis BASIC Generated At MCA/PC.

  1. Ultra-low-loss tapered optical fibers with minimal lengths

    CERN Document Server

    Nagai, Ryutaro

    2014-01-01

    We design and fabricate ultra-low-loss tapered optical fibers (TOFs) with minimal lengths. We first optimize variations of the torch scan length using the flame-brush method for fabricating TOFs with taper angles that satisfy the adiabaticity criteria. We accordingly fabricate TOFs with optimal shapes and compare their transmission to TOFs with a constant taper angle and TOFs with an exponential shape. The highest transmission measured for TOFs with an optimal shape is in excess of 99.7 % with a total TOF length of only 23 mm, whereas TOFs with a constant taper angle of 2 mrad reach 99.6 % transmission for a 63 mm TOF length.

  2. Ultra-low emittance X-band photocathode RF gun

    Institute of Scientific and Technical Information of China (English)

    TANG Chuan-Xiang; LIU Xiao-Han

    2009-01-01

    In this paper,we present the simulation results of a 1.6 cell X-band photocathode RF gun for ultra-low emittance electron beams.It will work at 9.3 GHz.The emittance,bunch length,electron energy and energy spread at the gun exit are optimized at bunch charge of 1pC using PARMELA.Electron bunches type coupler is adopted in this gun and an initial simulation by MAFIA is also given in this paper.

  3. Cryostat for Ultra-low-energy Threshold Germanium Spectrometers

    CERN Document Server

    Aalseth, Craig E; Fast, James E; Hossbach, Todd W; Orrell, John L; Overman, Cory T; Vandevender, Brent A

    2012-01-01

    This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is given. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance.

  4. Purification of Metal Fluorides for the Ultra Low Loss Program

    Science.gov (United States)

    1990-08-06

    of such high purity can be prepared and incorporated into a ZBLAN glass fiber? The purpose of this report is twofold; firstly determine where we are in...via radiotracer) to fix the absorption contribution of two of the five components of ZBLAN glass . Manuscrip appro d May 14. 1990. t • I I n | | | a...materials and the glass must be in the part-per trillion regime. A crucial question for the ultra low loss program’s viability is whether materials

  5. Ultra-low-power short-range radios

    CERN Document Server

    Chandrakasan, Anantha

    2015-01-01

    This book explores the design of ultra-low-power radio-frequency integrated circuits (RFICs), with communication distances ranging from a few centimeters to a few meters. Such radios have unique challenges compared to longer-range, higher-powered systems. As a result, many different applications are covered, ranging from body-area networks to transcutaneous implant communications and Internet-of-Things devices. A mix of introductory and cutting-edge design techniques and architectures which facilitate each of these applications are discussed in detail. Specifically, this book covers:.

  6. Ultra-low background measurements of decayed aerosol filters.

    Science.gov (United States)

    Aalseth, Craig; Andreotti, Erica; Arnold, Dirk; Cabeza, Joan-Albert Sanchez; Degering, Detlev; Giuliani, Andrea; de Orduña, Raquel Gonzales; Gurriaran, Rodolfo; Hult, Mikael; Keillor, Martin; Laubenstein, Matthias; le Petit, Gilbert; Margineanu, Romul Mircea; Matthews, Murray; Miley, Harry; Osvath, Iolanda; Pellicciari, Monica; Plastino, Wolfango; Simgen, Hardy; Weber, Marc; Werzi, Robert

    Aerosol samples collected on filter media were analyzed using HPGe detectors employing varying background-reduction techniques in order to experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS). In this way, realistic estimates of the impact of low-background methodology on the sensitivity obtained in systems such as the IMS were assessed. The current detectability requirement of stations in the IMS is 30 μBq/m(3) of air for (140)Ba, which would imply ~10(6) fissions per daily sample. Importantly, this is for a fresh aerosol filter. One week of decay reduces the intrinsic background from radon daughters in the sample allowing much higher sensitivity measurement of relevant isotopes, including (131)I. An experiment was conducted in which decayed filter samples were measured at a variety of underground locations using Ultra-Low Background (ULB) gamma spectroscopy technology. The impacts of the decay and ULB are discussed.

  7. Development of Ultra-Low-Noise TES Bolometer Arrays

    Science.gov (United States)

    Suzuki, T.; Khosropanah, P.; Ridder, M. L.; Hijmering, R. A.; Gao, J. R.; Akamatsu, H.; Gottardi, L.; van der Kuur, J.; Jackson, B. D.

    2016-07-01

    SRON is developing ultra-low-noise transition edge sensors (TESs) based on a superconducting Ti/Au bilayer on a suspended SiN island with SiN legs for SAFARI aboard SPICA. We have two major concerns about realizing TESs with an ultra-low NEP of 2× 10^{-19} hbox {W}/√{{ {Hz}}}: achieving lower thermal conductance and no excess noise with respect to the phonon noise. To realize TESs with phonon-noise-limited NEPs, we need to make thinner ({TESs were fabricated in combination with different SiN island sizes and the presence or absence of an optical absorber. Those TESs have a thin (0.20 \\upmu hbox {m}), narrow (0.5-0.7 \\upmu hbox {m}), and long (340-460 \\upmu hbox {m}) SiN legs and show Tc of {˜ }93 hbox {mK} and Rn of {˜ }158 hbox {m}{Ω }. These TESs were characterized under AC bias using our frequency-division multiplexing readout (1-3 MHz) system. TESs without the absorber show NEPs as low as 1.1 × 10^{-19} hbox {W}/√{{ {Hz}}} with a reasonable response speed ({TESs with the absorber, we confirmed a higher hbox {NEP}_{el} ({˜ }5 × 10^{-19} hbox {W}/√{{ {Hz}}}) than that of TESs without the absorber likely due to stray light. The lowest NEP can make the new version of SAFARI with a grating spectrometer feasible.

  8. Ultra-low energy storage ring at FLAIR

    Energy Technology Data Exchange (ETDEWEB)

    Welsch, Carsten P., E-mail: c.p.welsch@liverpool.ac.uk [Cockcroft Institute and the University of Liverpool (United Kingdom); Papash, A. I.; Gorda, O. [Max Planck Institute for Nuclear Physics (Germany); Harasimowicz, J. [Cockcroft Institute and University of Liverpool (United Kingdom); Karamyshev, O.; Karamysheva, G. [Max Planck Institute for Nuclear Physics (Germany); Newton, D. [Cockcroft Institute and University of Liverpool (United Kingdom); Panniello, M. [Max Planck Institute for Nuclear Physics (Germany); Putignano, M.; Siggel-King, M. R. F. [Cockcroft Institute and University of Liverpool (United Kingdom); Smirnov, A. [Max Planck Institute for Nuclear Physics (Germany)

    2012-12-15

    The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV and possibly less. The USR has been completely redesigned over the past three years. The ring structure is based on a 'split achromat' lattice that allows in-ring experiments with internal gas jet target. Beam parameters might be adjusted in a wide range: from very short pulses in the nanosecond regime to a Coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Detailed investigations of the USR, including studies into the ring's long term beam dynamics, life time, equilibrium momentum spread and equilibrium lateral spread during collisions with an internal target were carried out. New tools and beam handling techniques for diagnostics of ultra-low energy ions at beam intensities less than 10{sup 6} were developed by the QUASAR Group. In this paper, progress on the USR project will be presented with an emphasis on the expected beam parameters available to the experiments at FLAIR.

  9. A magnetically shielded room with ultra low residual field and gradient

    CERN Document Server

    Altarev, I.; Beck, D.; Burghoff, M.; Chesnevskaya, S.; Chupp, T.; Degenkolb, S.; Fan, I.; Fierlinger, P.; Frei, A.; Gutsmiedl, E.; Knappe-Grüneberg, S.; Kuchler, F.; Lauer, T.; Link, P.; Lins, T.; Marino, M.; McAndrew, J.; Niessen, B.; Paul, S.; Petzoldt, G.; Schläpfer, U.; Schnabel, A.; Sharma, S.; Singh, J.; Stoepler, R.; Stuiber, S.; Sturm, M.; Taubenheim, B.; Trahms, L.; Voigt, J.; Zechlau, T.

    2014-01-01

    A versatile and portable magnetically shielded room with a field of (700 \\pm 200) pT within a central volume of 1m x 1m x 1m and a field gradient less than 300 pT/m is described. This performance represents more than a hundred-fold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus.

  10. Rotatable Small Permanent Magnet Array for Ultra-Low Field Nuclear Magnetic Resonance Instrumentation: A Concept Study.

    Directory of Open Access Journals (Sweden)

    Michael W Vogel

    Full Text Available We studied the feasibility of generating the variable magnetic fields required for ultra-low field nuclear magnetic resonance relaxometry with dynamically adjustable permanent magnets. Our motivation was to substitute traditional electromagnets by distributed permanent magnets, increasing system portability.The finite element method (COMSOL® was employed for the numerical study of a small permanent magnet array to calculate achievable magnetic field strength, homogeneity, switching time and magnetic forces. A manually operated prototype was simulated and constructed to validate the numerical approach and to verify the generated magnetic field.A concentric small permanent magnet array can be used to generate strong sample pre-polarisation and variable measurement fields for ultra-low field relaxometry via simple prescribed magnet rotations. Using the array, it is possible to achieve a pre-polarisation field strength above 100 mT and variable measurement fields ranging from 20-50 μT with 200 ppm absolute field homogeneity within a field-of-view of 5 x 5 x 5 cubic centimetres.A dynamic small permanent magnet array can generate multiple highly homogeneous magnetic fields required in ultra-low field nuclear magnetic resonance (NMR and magnetic resonance imaging (MRI instruments. This design can significantly reduce the volume and energy requirements of traditional systems based on electromagnets, improving portability considerably.

  11. Scenarios for the ATF2 Ultra-Low Betas Proposal

    Energy Technology Data Exchange (ETDEWEB)

    Marin, Eduardo; /CERN; Tomas, Rogelio; /CERN; Bambade, Philip; /Orsay, LAL; Kuroda, Shigeru; /KEK, Tsukuba; Okugi, Toshiyuki; /KEK, Tsukuba; Tauchi, Toshiaki; /KEK, Tsukuba; Terunuma, Nobuhiro; /KEK, Tsukuba; Urakawa, Junji; /KEK, Tsukuba; Parker, Brett; /Brookhaven; Seryi, Andrei; /SLAC; White, Glen; /SLAC; Woodley, Mark; /SLAC

    2012-06-29

    The current ATF2 Ultra-Low beta proposal was designed to achieve 20nm vertical IP beam size without considering the multipolar components of the FD magnets. In this paper we describe different scenarios that avoid the detrimental effect of these multipolar errors to the beam size at the interaction point (IP). The simplest approach consists in modifying the optics, but other solutions are studied as the introduction of super-conducting wigglers to reduce the emittance or the replacement of the normal-conducting focusing quadrupole in the Final Doublet (NC-QF1FF) with a super-conducting quadrupole one (SC-QF1FF). These are fully addressed in the paper.

  12. Development of an ultra low field-ripple electromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Naritoshi, E-mail: nari.kawamura@kek.jp [Muon Science Laboratory, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Irie, Yoshiro [Muon Science Laboratory, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Accelerator Laboratory, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Fujimori, Hiroshi; Miyake, Yasuhiro [Muon Science Laboratory, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan)

    2014-03-21

    We developed an ultra low field-ripple magnet by adopting a mineral insulation cable (MIC) which is used under high radiation field, and of which conductor is surrounded by MgO insulation layer and copper sheath. Magnetic field due to an alternating current in conductor is canceled by the induced current in the sheath. We made a solenoid magnet by MIC, and observed this cancelation effect in alternating currents from 50 Hz to 2.4 kHz. This effect has a tendency which is inversely proportion to the AC frequency, and the field ripple is suppressed by 10{sup −2} in 50 Hz and 3×10{sup −4} in 2.4 kHz. Namely, a power supply with the current ripple of 10{sup −4} is expected to generate a magnetic field with the ripple of 10{sup −6} or lower.

  13. Hydroxide-Assisted Bonding of Ultra-Low-Expansion Glass

    Science.gov (United States)

    Abramovici, Alexander; White, Victor

    2008-01-01

    A process for hydroxide-assisted bonding has been developed as a means of joining optical components made of ultra-low-expansion (ULE) glass, while maintaining sufficiently precise alignment between. The process is intended mainly for use in applications in which (1) bonding of glass optical components by use of epoxy does not enable attainment of the required accuracy and dimensional stability and (2) conventional optical contacting (which affords the required accuracy and stability) does not afford adequate bond strength. The basic concept of hydroxide-assisted bonding is not new. The development of the present process was prompted by two considerations: (1) The expertise in hydroxide-assisted bonding has resided in very few places and the experts have not been willing to reveal the details of their processes and (2) data on the reliability and strength attainable by hydroxide-assisted bonding have been scarce.

  14. Precision analysis of the photomultiplier response to ultra low signals

    CERN Document Server

    Degtiarenko, Pavel

    2016-01-01

    A new mathematical model for the description of the photon detector response functions measured in conditions of low light is presented, together with examples of the observed photomultiplier signal amplitude distributions, successfully described using the parameterized model equation. As opposed to the previously known approximations, the new model describes the underlying discrete statistical behavior of the photoelectron cascade multiplication processes in photon detectors. Important features of the model include the ability to represent the true single-photoelectron spectra from different photomultipliers with a variety of parameterized shapes, reflecting the variability in the design and in the individual parameters of the detectors. The new software tool is available for evaluation of the detectors' performance, response, and efficiency parameters that may be used in various applications including the ultra low background experiments such as the searches for Dark Matter and rare decays, underground neut...

  15. Ultra-low-head hydroelectric technology: A review

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Daqing; Deng, Zhiqun (Daniel)

    2017-10-01

    In recent years, distributed renewable energy-generation technologies, such as wind and solar, have developed rapidly. Nevertheless, the utilization of ultra-low-head (ULH) water energy (i.e., situations where the hydraulic head is less than 3 m or the water flow is more than 0.5 m/s with zero head) has received little attention. We believe that, through technological innovations and cost reductions, ULH hydropower has the potential to become an attractive, renewable, and sustainable resource. This paper investigates potential sites for ULH energy resources, the selection of relevant turbines and generators, simplification of civil works, and project costs. This review introduces the current achievements on ULH hydroelectric technology to stimulate discussions and participation of stakeholders to develop related technologies for further expanding its utilization as an important form of renewable energy.

  16. An ultra-low noise, high-voltage piezo driver

    CERN Document Server

    Pisenti, N C; Reschovsky, B J; Barker, D S; Campbell, G K

    2016-01-01

    We present an ultra-low noise, high-voltage driver suited for use with piezoelectric actuators and other low-current applications. The architecture uses a flyback switching regulator to generate up to 250V in our current design, with an output of 1 kV or more possible with small modifications. A high slew-rate op-amp suppresses the residual switching noise, yielding a total RMS noise of $\\approx 100\\mu$V (1 Hz--100 kHz). A low-voltage ($\\pm 10$V), high bandwidth signal can be summed with unity gain directly onto the output, making the driver well-suited for closed-loop feedback applications. Digital control enables both repeatable setpoints and sophisticated control logic, and the circuit consumes less than 150mA at $\\pm 15$V.

  17. Deformation Behavior of Ultra-low Carbon Steel in Ferrite Region during Warm Processing

    Institute of Scientific and Technical Information of China (English)

    XU Guang; CHEN Zhenye; LIU Li; YU Shengfu

    2008-01-01

    The hot deformation experiments of ultra-low carbon steel in ferrite range were carried out ina hot simulator in order to research hot deformation behaviors of ultra-low carbon steel in ferrite range at low temperature.The results show that the influences of deformation parameters on flow stress are different to those in austenitic deformation.The deformation characteristic parameters were calculated for ultra-low carbon steel in ferrite region.The flow stress equation for ultra-low carbon steel in ferritic deformation at low temperature was obtained.

  18. Ultra-low power integrated circuit design circuits, systems, and applications

    CERN Document Server

    Li, Dongmei; Wang, Zhihua

    2014-01-01

    This book describes the design of CMOS circuits for ultra-low power consumption including analog, radio frequency (RF), and digital signal processing circuits (DSP). The book addresses issues from circuit and system design to production design, and applies the ultra-low power circuits described to systems for digital hearing aids and capsule endoscope devices. Provides a valuable introduction to ultra-low power circuit design, aimed at practicing design engineers; Describes all key building blocks of ultra-low power circuits, from a systems perspective; Applies circuits and systems described to real product examples such as hearing aids and capsule endoscopes.

  19. Advanced Durable Flexible Ultra Low Outgassing Thermal Control Coatings for NASA Science Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I program proposes to synthesize novel nanoengineered ultra low out gassing elastomers and formulate high temperature capable flexible thermal control...

  20. Preliminary study on ultra low tube voltage (70kV)sequential scan with low-volume contrast media protocol for dual-source CT coronary angiography%70 kV超低管电压低对比剂用量冠状动脉CTA研究

    Institute of Scientific and Technical Information of China (English)

    曹剑; 王少华; 张龙江; 卢光明; 金征宇; 易妍; 王怡宁; 林路; 王明; 孔令燕; 薛华丹; 宋兰; 王志伟

    2014-01-01

    Objective:To investigate the application of ultra low tube voltage (70kV)for coronary artery CT angiog-raphy (CCTA)with low-volume contrast media and low inj ection rate on dual-source CT (DSCT)equipment with integrat-ed circuit (IC)detector.Methods:Fifty patients with body mass index (BMI)not more than 25kg/m2 were scanned with a prospectively ECG-triggering sequential CCTA protocol on DSCT.All patients were randomly divided into two groups:the injection rate and volume of contrast in Group A was 4.0ml/s and 32mL (350mg I/mL);those in Group B were 4.0mL/s and 50mL (350mg I/mL),respectively.Tube voltage of both groups was 70kV.The raw data were reconstructed with sino-gram affirmed iterative reconstruction (SAFIRE)technique.The differences of age,BMI,heart rate,background noise,sig-nal-to-noise ratio (SNR)and radiation dose between the two Groups were compared.Besides,the CT value and CNR of the aortic root and each segment of coronary arteries were compared.And Image quality (1~4,excellent to non-assessable)be-tween the two Groups was compared segment-based.Results:There were no significant differences in age,BMI,heart rate, background noise,SNR or radiation dose between the two Groups (all P>0.05),and the mean ED was about 0.90mSv.The CT value of the distal segment of each coronary arteries in Group B was higher than Group A,while there were no signifi-cant differences in the proximal and median segments between the two groups.However,the CNR of each segment of coro-nary arteries in Group B were higher than Group A (all P<0.01).Mean segment-based image quality scores showed no sig-nificant difference between the two Groups reconstructed with SAFIRE (Group A,1.16±0.18,Group B,1.18±0.18;P=0.75).The percentage of assessable segments in each Group were more than 98%.Conclusion:For patients with normal BMI,the use of tube voltage as 70kV with SAFIRE technique in DSCT equipped IC detector is feasible.And both the con-trast injection rate and volume can be much lower

  1. An Ultra-Low Power Turning Angle Based Biomedical Signal Compression Engine with Adaptive Threshold Tuning.

    Science.gov (United States)

    Zhou, Jun; Wang, Chao

    2017-08-06

    Intelligent sensing is drastically changing our everyday life including healthcare by biomedical signal monitoring, collection, and analytics. However, long-term healthcare monitoring generates tremendous data volume and demands significant wireless transmission power, which imposes a big challenge for wearable healthcare sensors usually powered by batteries. Efficient compression engine design to reduce wireless transmission data rate with ultra-low power consumption is essential for wearable miniaturized healthcare sensor systems. This paper presents an ultra-low power biomedical signal compression engine for healthcare data sensing and analytics in the era of big data and sensor intelligence. It extracts the feature points of the biomedical signal by window-based turning angle detection. The proposed approach has low complexity and thus low power consumption while achieving a large compression ratio (CR) and good quality of reconstructed signal. Near-threshold design technique is adopted to further reduce the power consumption on the circuit level. Besides, the angle threshold for compression can be adaptively tuned according to the error between the original signal and reconstructed signal to address the variation of signal characteristics from person to person or from channel to channel to meet the required signal quality with optimal CR. For demonstration, the proposed biomedical compression engine has been used and evaluated for ECG compression. It achieves an average (CR) of 71.08% and percentage root-mean-square difference (PRD) of 5.87% while consuming only 39 nW. Compared to several state-of-the-art ECG compression engines, the proposed design has significantly lower power consumption while achieving similar CRD and PRD, making it suitable for long-term wearable miniaturized sensor systems to sense and collect healthcare data for remote data analytics.

  2. Experiments on Quantum Hall Topological Phases in Ultra Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Du, Rui-Rui [Rice Univ., Houston, TX (United States). Dept. of Physics and Astronomy

    2015-02-14

    This project is to cool electrons in semiconductors to extremely low temperatures and to study new states of matter formed by low-dimensional electrons (or holes). At such low temperatures (and with an intense magnetic field), electronic behavior differs completely from ordinary ones observed at room temperatures or regular low temperature. Studies of electrons at such low temperatures would open the door for fundamental discoveries in condensed matter physics. Present studies have been focus on topological phases in the fractional quantum Hall effect in GaAs/AlGaAs semiconductor heterostructures, and the newly discovered (by this group) quantum spin Hall effect in InAs/GaSb materials. This project consists of the following components: 1) Development of efficient sample cooling techniques and electron thermometry: Our goal is to reach 1 mK electron temperature and reasonable determination of electron temperature; 2) Experiments at ultra-low temperatures: Our goal is to understand the energy scale of competing quantum phases, by measuring the temperature-dependence of transport features. Focus will be placed on such issues as the energy gap of the 5/2 state, and those of 12/5 (and possible 13/5); resistive signature of instability near 1/2 at ultra-low temperatures; 3) Measurement of the 5/2 gaps in the limit of small or large Zeeman energies: Our goal is to gain physics insight of 5/2 state at limiting experimental parameters, especially those properties concerning the spin polarization; 4) Experiments on tuning the electron-electron interaction in a screened quantum Hall system: Our goal is to gain understanding of the formation of paired fractional quantum Hall state as the interaction pseudo-potential is being modified by a nearby screening electron layer; 5) Experiments on the quantized helical edge states under a strong magnetic field and ultralow temperatures: our goal is to investigate both the bulk and edge states in a quantum spin Hall insulator under time

  3. Improving the ultra-low-power performance of IEEE 802.15.6 by adaptive synchronisation

    NARCIS (Netherlands)

    Timmons, N.F.; Scanlon, W.G.

    2011-01-01

    In ultra-low data rate wireless sensor networks (WSNs) waking up just to listen to a beacon every superframe can be a major waste of energy. This study introduces MedMAC, a medium access protocol for ultra-low data rate WSNs that achieves significant energy efficiency through a novel synchronisation

  4. Thermomechanical Property Characterization of Ultra Low-k Materials

    Science.gov (United States)

    Zhao, Jie-Hua; Gupta, Vikas; Mortensen, Clay D.; Lu, Kuan-Hsun; Edwards, Darvin R.; Johnson, David C.; Ho, Paul S.

    2009-06-01

    To meet electrical performance requirements, the industry is implementing ultra-low dielectric constant (ULK) materials in the back end of line interconnect structure. ULK dielectrics are inherently weak compared to traditional dielectrics and pose significant challenges to electronic packaging processes and reliability. Accurate mechanical properties are a pre-requisite for upfront risk assessments associated with low-k integration using numerical simulations. In this paper, techniques used to characterize ULK dielectric elastic modulus and in-plane/out-of-plane coefficient of thermal expansion will be presented and the data for a candidate ULK dielectric will be summarized. Nanoindentation of ULK films on substrate was used to determine the plane strain modulus. In the direction normal to the film, the temperature gradient of the thermal expansion strain along the film thickness was measured by x-ray reflectivity. In the plane of the film, the temperature gradient of the biaxial thermal stress was obtained by the substrate curvature measurements. A method to deduce Poisson's ratio of the thin ULK film is proposed using the data from the afore-mentioned characterization techniques.

  5. SQUID-based instrumentation for ultra-low-field MRI

    CERN Document Server

    Zotev, V S; Matlashov, A N; Urbaitis, A V; Kraus, R H

    2007-01-01

    Magnetic resonance imaging at ultra-low fields (ULF MRI) is a promising new imaging method that uses SQUID sensors to measure the spatially encoded precession of pre-polarized nuclear spin populations at a microtesla-range measurement field. In this work, design and performance of a seven-channel SQUID system for simultaneous 3D ULF MRI and MEG are described. The system consists of seven axial second-order SQUID gradiometers, characterized by magnetic field resolutions of 1.2 - 2.8 fT/rtHz. It also includes five sets of coils for 3D Fourier imaging with pre-polarization. Design components used for rapid switching of the pre-polarizing field and for protecting the SQUIDs from the pre-polarizing pulses are discussed. The system's performance is demonstrated by multi-channel 3D images of a preserved sheep brain acquired at 46 microtesla measurement field with 2.5 mm x 2.5 mm x 5 mm imaging resolution. The ULF MRI images exhibit greater contrast than images of the same brain obtained using conventional high-field...

  6. Ultra Low Surface Brightness Imaging with the Dragonfly Telephoto Array

    CERN Document Server

    Abraham, Roberto G

    2014-01-01

    We describe the Dragonfly Telephoto Array, a robotic imaging system optimized for the detection of extended ultra low surface brightness structures. The array consists of eight Canon 400mm f/2.8 telephoto lenses coupled to eight science-grade commercial CCD cameras. The lenses are mounted on a common framework and are co-aligned to image simultaneously the same position on the sky. The system provides an imaging capability equivalent to a 0.4m aperture f/1.0 refractor with a 2.6 deg X 1.9 deg field of view. The system has no obstructions in the light path, optimized baffling, and internal optical surfaces coated with a new generation of anti-reflection coatings based on sub-wavelength nanostructures. As a result, the array's point spread function has a factor of ~10 less scattered light at large radii than well-baffled reflecting telescopes. The Dragonfly Telephoto Array is capable of imaging extended structures to surface brightness levels below 30 mag/arcsec^2 in 10h integrations (without binning or foregro...

  7. Voltage-Mode Multifunction Biquadratic Filters Using New Ultra-Low-Power Differential Difference Current Conveyors

    Directory of Open Access Journals (Sweden)

    M. Kumngern

    2013-06-01

    Full Text Available This paper presents two low-power voltage-mode multifunction biquadratic filters using differential difference current conveyors. Each proposed circuit employs three differential difference current conveyors, two grounded capacitors and two grounded resistors. The low-voltage ultra-low-power differential difference current conveyor is used to provide low-power consumption of the proposed filters. By appropriately connecting the input and output terminals, the proposed filters can provide low-pass, band-pass, high-pass, band-stop and all-pass voltage responses at high-input terminals, which is a desirable feature for voltage-mode operations. The natural frequency and the quality factor can be orthogonally set by adjusting the circuit components. For realizing all the filter responses, no inverting-type input signal requirements as well as no component-matching conditional requirements are imposed. The incremental parameter sensitivities are also low. The characteristics of the proposed circuits are simulated by using PSPICE simulators to confirm the presented theory.

  8. Ultra-low noise optical phase-locked loop

    Science.gov (United States)

    Ayotte, Simon; Babin, André; Costin, François

    2014-03-01

    The relative phase between two fiber lasers is controlled via a high performance optical phase-locked loop (OPLL). Two parameters are of particular importance for the design: the intrinsic phase noise of the laser (i.e. its linewidth) and a high-gain, low-noise electronic locking loop. In this work, one of the lowest phase noise fiber lasers commercially available was selected (i.e. NP Photonics Rock fiber laser module), with sub-kHz linewidth at 1550.12 nm. However, the fast tuning mechanism of such lasers is through stretching its cavity length with a piezoelectric transducer which has a few 10s kHz bandwidth. To further increase the locking loop bandwidth to several MHz, a second tuning mechanism is used by adding a Lithium Niobate phase modulator in the laser signal path. The OPLL is thus divided into two locking loops, a slow loop acting on the laser piezoelectric transducer and a fast loop acting on the phase modulator. The beat signal between the two phase-locked lasers yields a highly pure sine wave with an integrated phase error of 0.0012 rad. This is orders of magnitude lower than similar existing systems such as the Laser Synthesizer used for distribution of photonic local oscillator (LO) for the Atacama Large Millimeter Array radio telescope in Chile. Other applications for ultra-low noise OPLL include coherent power combining, Brillouin sensing, light detection and ranging (LIDAR), fiber optic gyroscopes, phased array antenna and beam steering, generation of LOs for next generation coherent communication systems, coherent analog optical links, terahertz generation and coherent spectroscopy.

  9. Ultra-low noise miniaturized neural amplifier with hardware averaging

    Science.gov (United States)

    Dweiri, Yazan M.; Eggers, Thomas; McCallum, Grant; Durand, Dominique M.

    2015-08-01

    Objective. Peripheral nerves carry neural signals that could be used to control hybrid bionic systems. Cuff electrodes provide a robust and stable interface but the recorded signal amplitude is small (amplifier should add as little noise as possible. Since mainstream neural amplifiers have a baseline noise of 2 μVrms or higher, novel designs are required. Approach. Here we apply the concept of hardware averaging to nerve recordings obtained with cuff electrodes. An optimization procedure is developed to minimize noise and power simultaneously. The novel design was based on existing neural amplifiers (Intan Technologies, LLC) and is validated with signals obtained from the FINE in chronic dog experiments. Main results. We showed that hardware averaging leads to a reduction in the total recording noise by a factor of 1/√N or less depending on the source resistance. Chronic recording of physiological activity with FINE using the presented design showed significant improvement on the recorded baseline noise with at least two parallel operation transconductance amplifiers leading to a 46.1% reduction at N = 8. The functionality of these recordings was quantified by the SNR improvement and shown to be significant for N = 3 or more. The present design was shown to be capable of generating amplifier. Significance. These results demonstrate the efficacy of hardware averaging on noise improvement for neural recording with cuff electrodes, and can accommodate the presence of high source impedances that are associated with the miniaturized contacts and the high channel count in electrode arrays. This technique can be adopted for other applications where miniaturized and implantable multichannel acquisition systems with ultra-low noise and low power are required.

  10. Ultra Low Sulfur Home Heating Oil Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Batey, John E. [Energy Research Center, Inc., Easton, CT (United States); McDonald, Roger [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-30

    This Ultra Low Sulfur (ULS) Home Heating Oil Demonstration Project was funded by the New York State Energy Research and Development Authority (NYSERDA) and has successfully quantified the environmental and economic benefits of switching to ULS (15 PPM sulfur) heating oil. It advances a prior field study of Low Sulfur (500 ppm sulfur) heating oil funded by NYSERDA and laboratory research conducted by Brookhaven National Laboratory (BNL) and Canadian researchers. The sulfur oxide and particulate matter (PM) emissions are greatly reduced as are boiler cleaning costs through extending cleaning intervals. Both the sulfur oxide and PM emission rates are directly related to the fuel oil sulfur content. The sulfur oxide and PM emission rates approach near-zero levels by switching heating equipment to ULS fuel oil, and these emissions become comparable to heating equipment fired by natural gas. This demonstration project included an in-depth review and analysis of service records for both the ULS and control groups to determine any difference in the service needs for the two groups. The detailed service records for both groups were collected and analyzed and the results were entered into two spreadsheets that enabled a quantitative side-by-side comparison of equipment service for the entire duration of the ULS test project. The service frequency for the ULS and control group were very similar and did indicate increased service frequency for the ULS group. In fact, the service frequency with the ULS group was slightly less (7.5 percent) than the control group. The only exception was that three burner fuel pump required replacement for the ULS group and none were required for the control group.

  11. An ultra-low-power image compressor for capsule endoscope

    Directory of Open Access Journals (Sweden)

    Weng Ping-Kuo

    2006-02-01

    Full Text Available Abstract Background Gastrointestinal (GI endoscopy has been popularly applied for the diagnosis of diseases of the alimentary canal including Crohn's Disease, Celiac disease and other malabsorption disorders, benign and malignant tumors of the small intestine, vascular disorders and medication related small bowel injury. The wireless capsule endoscope has been successfully utilized to diagnose diseases of the small intestine and alleviate the discomfort and pain of patients. However, the resolution of demosaicked image is still low, and some interesting spots may be unintentionally omitted. Especially, the images will be severely distorted when physicians zoom images in for detailed diagnosis. Increasing resolution may cause significant power consumption in RF transmitter; hence, image compression is necessary for saving the power dissipation of RF transmitter. To overcome this drawback, we have been developing a new capsule endoscope, called GICam. Methods We developed an ultra-low-power image compression processor for capsule endoscope or swallowable imaging capsules. In applications of capsule endoscopy, it is imperative to consider battery life/performance trade-offs. Applying state-of-the-art video compression techniques may significantly reduce the image bit rate by their high compression ratio, but they all require intensive computation and consume much battery power. There are many fast compression algorithms for reducing computation load; however, they may result in distortion of the original image, which is not good for use in the medical care. Thus, this paper will first simplify traditional video compression algorithms and propose a scalable compression architecture. Conclusion As the result, the developed video compressor only costs 31 K gates at 2 frames per second, consumes 14.92 mW, and reduces the video size by 75% at least.

  12. Ultra-low-voltage design of energy-efficient digital circuits

    CERN Document Server

    Reynders, Nele

    2015-01-01

    This book focuses on increasing the energy-efficiency of electronic devices so that portable applications can have a longer stand-alone time on the same battery. The authors explain the energy-efficiency benefits that ultra-low-voltage circuits provide and provide answers to tackle the challenges which ultra-low-voltage operation poses. An innovative design methodology is presented, verified, and validated by four prototypes in advanced CMOS technologies. These prototypes are shown to achieve high energy-efficiency through their successful functionality at ultra-low supply voltages.

  13. Uncertainty in peat volume and soil carbon estimated using ground-penetrating radar and probing

    Science.gov (United States)

    Andrew D. Parsekian; Lee Slater; Dimitrios Ntarlagiannis; James Nolan; Stephen D. Sebestyen; Randall K. Kolka; Paul J. Hanson

    2012-01-01

    Estimating soil C stock in a peatland is highly dependent on accurate measurement of the peat volume. In this study, we evaluated the uncertainty in calculations of peat volume using high-resolution data to resolve the three-dimensional structure of a peat basin based on both direct (push probes) and indirect geophysical (ground-penetrating radar) measurements. We...

  14. Inhalability for aerosols at ultra-low windspeeds

    Energy Technology Data Exchange (ETDEWEB)

    Sleeth, Darrah K; Vincent, James H, E-mail: jhv@umich.ed [Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, 48109 (United States)

    2009-02-01

    Most previous experimental studies of aerosol inhalability were conducted in wind tunnels for windspeeds greater than 0.5 ms-{sup 1}. While that body of work was used to establish a convention for the inhalable fraction, results from studies in calm air chambers (for essentially zero windspeed) are being discussed as the basis of a modified criterion. However, information is lacking for windspeeds in the intermediate range, which - it so happens - pertain to most actual workplaces. With this in mind, we have developed a new experimental system to assess inhalability - and, ultimately, personal sampler performance - for aerosols with particle aerodynamic diameter within the range from about 9 to 90 mum for ultra-low windspeed environments from about 0.1 to 0.5 ms{sup 1}. This new system contains an aerosol test facility, fully described elsewhere, that combines the physical attributes and performance characteristics of moving air wind tunnels and calm air chambers, both of which have featured individually in previous research. It also contains a specially-designed breathing, heated, life-sized mannequin that allows for accurate recovery of test particulate material that has been inhaled. Procedures have been developed that employ test aerosols of well-defined particle size distribution generated mechanically from narrowly-graded powders of fused alumina. Using this new system, we have conducted an extensive set of new experiments to measure the inhalability of a human subject (as represented by the mannequin), aimed at filling the current knowledge gap for conditions that are more realistic than those embodied in most previous research. These data reveal that inhalability throughout the range of interest is significantly different based on windspeed, indicating a rise in aspiration efficiency as windspeed decreases. Breathing flowrate and mode of breathing (i.e. nose versus mouth breathing) did not show significant differences for the inhalability of aerosols. On

  15. Inhalability for aerosols at ultra-low windspeeds

    Science.gov (United States)

    Sleeth, Darrah K.; Vincent, James H.

    2009-02-01

    Most previous experimental studies of aerosol inhalability were conducted in wind tunnels for windspeeds greater than 0.5 ms-1. While that body of work was used to establish a convention for the inhalable fraction, results from studies in calm air chambers (for essentially zero windspeed) are being discussed as the basis of a modified criterion. However, information is lacking for windspeeds in the intermediate range, which - it so happens - pertain to most actual workplaces. With this in mind, we have developed a new experimental system to assess inhalability - and, ultimately, personal sampler performance - for aerosols with particle aerodynamic diameter within the range from about 9 to 90 μm for ultra-low windspeed environments from about 0.1 to 0.5 ms1. This new system contains an aerosol test facility, fully described elsewhere, that combines the physical attributes and performance characteristics of moving air wind tunnels and calm air chambers, both of which have featured individually in previous research. It also contains a specially-designed breathing, heated, life-sized mannequin that allows for accurate recovery of test particulate material that has been inhaled. Procedures have been developed that employ test aerosols of well-defined particle size distribution generated mechanically from narrowly-graded powders of fused alumina. Using this new system, we have conducted an extensive set of new experiments to measure the inhalability of a human subject (as represented by the mannequin), aimed at filling the current knowledge gap for conditions that are more realistic than those embodied in most previous research. These data reveal that inhalability throughout the range of interest is significantly different based on windspeed, indicating a rise in aspiration efficiency as windspeed decreases. Breathing flowrate and mode of breathing (i.e. nose versus mouth breathing) did not show significant differences for the inhalability of aerosols. On the whole

  16. Ground Operations Aerospace Language (GOAL). Volume 3: Data bank

    Science.gov (United States)

    1973-01-01

    The GOAL (Ground Operations Aerospace Language) test programming language was developed for use in ground checkout operations in a space vehicle launch environment. To insure compatibility with a maximum number of applications, a systematic and error-free method of referencing command/response (analog and digital) hardware measurements is a principle feature of the language. Central to the concept of requiring the test language to be independent of launch complex equipment and terminology is that of addressing measurements via symbolic names that have meaning directly in the hardware units being tested. To form the link from test program through test system interfaces to the units being tested the concept of a data bank has been introduced. The data bank is actually a large cross-reference table that provides pertinent hardware data such as interface unit addresses, data bus routings, or any other system values required to locate and access measurements.

  17. Ground Operations Aerospace Language (GOAL). Volume 2: Compiler

    Science.gov (United States)

    1973-01-01

    The principal elements and functions of the Ground Operations Aerospace Language (GOAL) compiler are presented. The technique used to transcribe the syntax diagrams into machine processable format for use by the parsing routines is described. An explanation of the parsing technique used to process GOAL source statements is included. The compiler diagnostics and the output reports generated during a GOAL compilation are explained. A description of the GOAL program package is provided.

  18. Ultra-Low Power Extreme Environment Capable Avionics System-on-a-Chip Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop ultra-low-power, wide-temperature (-150° C to +250 ° C), digital System-on-a-Chip (SOC) ASIC technology in a high resolution, inherently rad-hard IBM...

  19. An Ultra-low Frequency Modal Testing Suspension System for High Precision Air Pressure Control

    National Research Council Canada - National Science Library

    Qiaoling Yuan; Jianhui Sun; Xiaohang Shan; Biqing Ye

    2014-01-01

      In this paper, as a resolution for air pressure control challenges in ultra-low frequency modal testing suspension systems, an incremental PID control algorithm with a dead band is applied to achieve...

  20. Hydrogeology of the 200 Areas low-level burial grounds: An interim report: Volume 2, Appendixes

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Bjornstad, B.N.; Bergeron, M.P.; Wallace, D.W.; Newcomer, D.R.; Schramke, J.A.; Chamness, M.A.; Cline, C.S.; Airhart, S.P.; Wilbur, J.S.

    1989-01-01

    This report presents information derived form the installation of 35 ground-water monitoring wells around six low-level radioactive/hazardous waste burial grounds located in the 200 Areas of the Hanford Site in southeastern Washington State. This information was collected between May 20, 1987 and August 1, 1988. The contents of this report have been divided into two volumes. Volume 1 contains the main text. This Volume contains the appendixes, including data and supporting information that verify content and results found in the main text.

  1. A magnetically shielded room with ultra low residual field and gradient.

    Science.gov (United States)

    Altarev, I; Babcock, E; Beck, D; Burghoff, M; Chesnevskaya, S; Chupp, T; Degenkolb, S; Fan, I; Fierlinger, P; Frei, A; Gutsmiedl, E; Knappe-Grüneberg, S; Kuchler, F; Lauer, T; Link, P; Lins, T; Marino, M; McAndrew, J; Niessen, B; Paul, S; Petzoldt, G; Schläpfer, U; Schnabel, A; Sharma, S; Singh, J; Stoepler, R; Stuiber, S; Sturm, M; Taubenheim, B; Trahms, L; Voigt, J; Zechlau, T

    2014-07-01

    A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.

  2. Experimental Study of the Feasibility of Air Flooding in an Ultra-Low Permeability Reservoir

    Directory of Open Access Journals (Sweden)

    Guohui Qu

    2016-09-01

    Full Text Available The development effect of water flooding in an ultra-low permeability reservoir is poor due to its poor physical properties and high shale content, so an experimental study of air flooding which helps to complement energy production was carried out. Based on the Accelerating Rate Calorimeter experimental results, the crude oil of N block in L oilfield can undergo low-temperature oxidation reactions, which are the basic condition for air flooding. Three groups of experimental natural cylinder cores designed for oil displacement, water flooding and air flooding were used respectively, and the relationship between differential pressure, oil recovery, injection capacity with injection volume was investigated. It is observed that the recovery efficiency increased 2.58%, the injection-production pressure difference dropped 60% and the injection capability increased 60% in the experiment of shifting air flooding after water flooding to 75% moisture content, compared with water flooding alone. It has been shown in the results that the recovery efficiency improved sharply more than water flooding, the effect of depressurization and augmented injection was obvious, and the air displacement was thus validated. We suggest that other science and technology workers should perform further tests and verify this result through numerical simulation.

  3. Controlling the phase locking of stochastic magnetic bits for ultra-low power computation

    Science.gov (United States)

    Mizrahi, Alice; Locatelli, Nicolas; Lebrun, Romain; Cros, Vincent; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Querlioz, Damien; Grollier, Julie

    2016-07-01

    When fabricating magnetic memories, one of the main challenges is to maintain the bit stability while downscaling. Indeed, for magnetic volumes of a few thousand nm3, the energy barrier between magnetic configurations becomes comparable to the thermal energy at room temperature. Then, switches of the magnetization spontaneously occur. These volatile, superparamagnetic nanomagnets are generally considered useless. But what if we could use them as low power computational building blocks? Remarkably, they can oscillate without the need of any external dc drive, and despite their stochastic nature, they can beat in unison with an external periodic signal. Here we show that the phase locking of superparamagnetic tunnel junctions can be induced and suppressed by electrical noise injection. We develop a comprehensive model giving the conditions for synchronization, and predict that it can be achieved with a total energy cost lower than 10‑13 J. Our results open the path to ultra-low power computation based on the controlled synchronization of oscillators.

  4. Performance and cost of automotive fuel cell systems with ultra-low platinum loadings

    Science.gov (United States)

    Ahluwalia, R. K.; Wang, X.; Kwon, J.; Rousseau, A.; Kalinoski, J.; James, B.; Marcinkoski, J.

    2011-05-01

    An automotive polymer-electrolyte fuel cell (PEFC) system with ultra-low platinum loading (0.15 mg-Pt cm-2) has been analyzed to determine the relationship between its design-point efficiency and the system efficiency at part loads, efficiency over drive cycles, stack and system costs, and heat rejection. The membrane electrode assemblies in the reference PEFC stack use nanostructured, thin-film ternary catalysts supported on organic whiskers and a modified perfluorosulfonic acid membrane. The analyses show that the stack Pt content can be reduced by 50% and the projected high-volume manufacturing cost by >45% for the stack and by 25% for the system, if the design-point system efficiency is lowered from 50% to 40%. The resulting penalties in performance are a indicate that thermal management in the lower efficiency systems is very challenging and that the radiator becomes bulky if the stack temperature cannot be allowed to increase to 90-95 °C under driving conditions where heat rejection is difficult.

  5. Hydrogeology of the 200 Areas low-level burial grounds: An interim report: Volume 1, Text

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Bjornstad, B.N.; Bergeron, M.P.; Wallace, D.W.; Newcomer, D.R.; Schramke, J.A.; Chamness, M.A.; Cline, C.S.; Airhart, S.P.; Wilbur, J.S.

    1989-01-01

    This report presents information derived from the installation of 35 ground-water monitoring wells around six low-level radioactive/hazardous waste burial grounds located in the 200 Areas of the Hanford Site in southeastern Washington State. This information was collected between May 20, 1987 and August 1, 1988. The contents of this report have been divided into two volumes. This volume contains the main text. Volume 2 contains the appendixes, including data and supporting information that verify content and results found in the main text. This report documents information collected by the Pacific Northwest Laboratory at the request of Westinghouse Hanford Company. Presented in this report are the preliminary interpretations of the hydrogeologic environment of six low-level burial grounds, which comprise four waste management areas (WMAs) located in the 200 Areas of the Hanford Site. This information and its accompanying interpretations were derived from sampling and testing activities associated with the construction of 35 ground-water monitoring wells as well as a multitude of previously existing boreholes. The new monitoring wells were installed as part of a ground-water monitoring program initiated in 1986. This ground-water monitoring program is based on requirements for interim status facilities in compliance with the Resource Conservation and Recovery Act (1976).

  6. The Audi ultra low emission system: requirements for development and system integration; Das Audi Ultra Low Emission System: Anforderungen an Entwicklung und Systemintegration

    Energy Technology Data Exchange (ETDEWEB)

    Middelhauve, Georg; Meister, Alexander; Halbei, Julia [Audi AG, Ingolstadt (Germany)

    2008-07-01

    Based on a combination of engine modifications and the introduction of a new technology into the exhaust aftertreatment the Audi ultra low emission system achieves a very efficient minimization of the exhaust emissions and a reduction of the fuel consumption. The new technology sets a new standard in the successful history of TDI engines. The present article focuses on the NOx reduction in the exhaust aftertreatment and the related AdBlue registered -tank system of the Audi A4 3,0 I V6-TDI with ultra low emission system. In the centre of the attention is the integration of a complex system containing hydraulic, electr(on)ic and mechatronic components into the package and system control of an existing vehicle. (orig.)

  7. Multi-Threshold NULL Convention Logic (MTNCL: An Ultra-Low Power Asynchronous Circuit Design Methodology

    Directory of Open Access Journals (Sweden)

    Liang Zhou

    2015-05-01

    Full Text Available This paper develops an ultra-low power asynchronous circuit design methodology, called Multi-Threshold NULL Convention Logic (MTNCL, also known as Sleep Convention Logic (SCL, which combines Multi-Threshold CMOS (MTCMOS with NULL Convention Logic (NCL, to yield significant power reduction without any of the drawbacks of applying MTCMOS to synchronous circuits. In contrast to other power reduction techniques that usually result in large area overhead, MTNCL circuits are actually smaller than their original NCL versions. MTNCL utilizes high-Vt transistors to gate power and ground of a low-Vt logic block to provide for both fast switching and very low leakage power when idle. To demonstrate the advantages of MTNCL, a number of 32-bit IEEE single-precision floating-point co-processors were designed for comparison using the 1.2 V IBM 8RF-LM 130 nm CMOS process: original NCL, MTNCL with just combinational logic (C/L slept, Bit-Wise MTNCL (BWMTNCL, MTNCL with C/L and completion logic slept, MTNCL with C/L, completion logic, and registers slept, MTNCL with Safe Sleep architecture, and synchronous MTCMOS. These designs are compared in terms of throughput, area, dynamic energy, and idle power, showing the tradeoffs between the various MTNCL architectures, and that the best MTNCL design is much better than the original NCL design in all aspects, and much better than the synchronous MTCMOS design in terms of area, energy per operation, and idle power, although the synchronous design can operate faster.

  8. Fluctuation-induced dynamics of multiphase liquid jets with ultra-low interfacial tension

    CERN Document Server

    Sauret, Alban; Shum, Ho Cheung

    2013-01-01

    Control of fluid dynamics at the micrometer scale is essential to emulsion science and materials design, which is ubiquitous in everyday life and is frequently encountered in industrial applications. Most studies on multiphase flow focus on oil-water systems with substantial interfacial tension. Advances in microfluidics have enabled the study of multiphase flow with more complex dynamics. Here, we show that the evolution of the interface in a jet surrounded by a co-flowing continuous phase with an ultra-low interfacial tension presents new opportunities to the control of flow morphologies. The introduction of a harmonic perturbation to the dispersed phase leads to the formation of interfaces with unique shapes. The periodic structures can be tuned by controlling the fluid flow rates and the input perturbation; this demonstrates the importance of the inertial effects in flow control at ultra-low interfacial tension. Our work provides new insights into microfluidic flows at ultra-low interfacial tension and th...

  9. Ultra Low-Dose Radiation: Stress Responses and Impacts Using Rice as a Grass Model

    Directory of Open Access Journals (Sweden)

    Junko Shibato

    2009-03-01

    Full Text Available We report molecular changes in leaves of rice plants (Oryza sativa L. - reference crop plant and grass model exposed to ultra low-dose ionizing radiation, first using contaminated soil from the exclusion zone around Chernobyl reactor site. Results revealed induction of stress-related marker genes (Northern blot and secondary metabolites (LC-MS/MS in irradiated leaf segments over appropriate control. Second, employing the same in vitro model system, we replicated results of the first experiment using in-house fabricated sources of ultra low-dose gamma (g rays and selected marker genes by RT-PCR. Results suggest the usefulness of the rice model in studying ultra low-dose radiation response/s.

  10. Ultra-low dose CT attenuation correction for PET/CT

    Science.gov (United States)

    Xia, Ting; Alessio, Adam M.; De Man, Bruno; Manjeshwar, Ravindra; Asma, Evren; Kinahan, Paul E.

    2012-01-01

    A challenge for positron emission tomography/computed tomography (PET/CT) quantitation is patient respiratory motion, which can cause an underestimation of lesion activity uptake and an overestimation of lesion volume. Several respiratory motion correction methods benefit from longer duration CT scans that are phase matched with PET scans. However, even with the currently available, lowest dose CT techniques, extended duration cine CT scans impart a substantially high radiation dose. This study evaluates methods designed to reduce CT radiation dose in PET/CT scanning. We investigated selected combinations of dose reduced acquisition and noise suppression methods that take advantage of the reduced requirement of CT for PET attenuation correction (AC). These include reducing CT tube current, optimizing CT tube voltage, adding filtration, CT sinogram smoothing and clipping. We explored the impact of these methods on PET quantitation via simulations on different digital phantoms. CT tube current can be reduced much lower for AC than that in low dose CT protocols. Spectra that are higher energy and narrower are generally more dose efficient with respect to PET image quality. Sinogram smoothing could be used to compensate for the increased noise and artifacts at radiation dose reduced CT images, which allows for a further reduction of CT dose with no penalty for PET image quantitation. When CT is not used for diagnostic and anatomical localization purposes, we showed that ultra-low dose CT for PET/CT is feasible. The significant dose reduction strategies proposed here could enable respiratory motion compensation methods that require extended duration CT scans and reduce radiation exposure in general for all PET/CT imaging.

  11. Ultra-low-temperature cooling of two-dimensional electron gas

    Science.gov (United States)

    Xia, J. S.; Adams, E. D.; Shvarts, V.; Pan, W.; Stormer, H. L.; Tsui, D. C.

    2000-05-01

    A new design has been used for cooling GaAs/Al xGa 1- xAs sample to ultra-low-temperatures. The sample, with electrical contacts directly soldered to the sintered silver powder heat exchangers, was immersed in liquid 3He, which was cooled by a PrNI 5 nuclear refrigerator. The data analysis shows that the two-dimensional electron gas (2DEG) was cooled to 4.0 mK at the refrigerator base temperature Tb of 2.0 mK. The design with heat exchanger cooling is applicable to any ultra-low-temperature transport measurements of 2DEG system.

  12. Enhancing the tumor discrimination using antibody-activated magnetic nanoparticles in ultra-low magnetic fields

    Science.gov (United States)

    Yang, H. C.; Huang, K. W.; Liao, S. H.; Horng, H. E.; Chieh, J. J.; Chen, H. H.; Chen, M. J.; Chen, K. L.; Wang, L. M.

    2013-01-01

    In this paper, we report an enhanced liver tumor discrimination for rats using antibody-activated magnetic nanoparticles (MNs) and ultra-low-field magnetic resonance imaging ex vivo. It was found that the intensity ratio between the magnetic resonance image of tumor and normal liver tissues is 2-3 absence of antibody-activated MNs in rats. The intensity ratio rises to ˜100 when antibody-activated MNs are expressed in liver tumors through vein injection. Enhancing tumor discrimination using antibody-activated MNs is demonstrated using T1-weighted contrast imaging in ultra-low magnetic fields.

  13. Clamped seismic metamaterials: ultra-low frequency stop bands

    Science.gov (United States)

    Achaoui, Y.; Antonakakis, T.; Brûlé, S.; Craster, R. V.; Enoch, S.; Guenneau, S.

    2017-06-01

    The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1-10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0-30 Hz.

  14. Ultra-low threshold gallium nitride photonic crystal nanobeam laser

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Nan, E-mail: nanniu@fas.harvard.edu; Woolf, Alexander; Wang, Danqing; Hu, Evelyn L. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Zhu, Tongtong; Oliver, Rachel A. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Quan, Qimin [Rowland Institute at Harvard University, Cambridge, Massachusetts 02142 (United States)

    2015-06-08

    We report exceptionally low thresholds (9.1 μJ/cm{sup 2}) for room temperature lasing at ∼450 nm in optically pumped Gallium Nitride (GaN) nanobeam cavity structures. The nanobeam cavity geometry provides high theoretical Q (>100 000) with small modal volume, leading to a high spontaneous emission factor, β = 0.94. The active layer materials are Indium Gallium Nitride (InGaN) fragmented quantum wells (fQWs), a critical factor in achieving the low thresholds, which are an order-of-magnitude lower than obtainable with continuous QW active layers. We suggest that the extra confinement of photo-generated carriers for fQWs (compared to QWs) is responsible for the excellent performance.

  15. Ultra-low loss nano-taper coupler for Silicon-on-Insulator ridge waveguide

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Ou, Haiyan;

    2010-01-01

    A nano-taper coupler is optimized specially for the transverse-magnetic mode for interfacing light between a silicon-on-insulator ridge waveguide and a single-mode fiber. An ultra-low coupling loss of ~0.36dB is achieved for the nano-taper coupler....

  16. Specific gravity and API gravity of biodiesel and ultra-low sulfur diesel (ULSD) blends

    Science.gov (United States)

    Biodiesel is an alternative fuel made from vegetable oils and animal fats. In 2006, the U. S. Environmental Protection Agency mandated a maximum sulfur content of 15 ppm in on-road diesel fuels. Processing to produce the new ultra-low sulfur petrodiesel (ULSD) alters specific gravity (SG) and othe...

  17. A Comparative Study of Ultra-Low Voltage Digital Circuit Design

    Directory of Open Access Journals (Sweden)

    Aaron Arthurs

    2012-07-01

    Full Text Available Ultra-low voltage digital circuit design is an active research area, especially for portable applications such as wearable electronics, intelligent remote sensors, implantable medical devices, and energy-harvesting systems. Due to their application scenarios and circuit components, two major goals for these systems are minimizing energy consumption and improving compatibility with low-voltage power supplies and analog components. The most effective solution to achieve these goals is to reduce the supply voltage, which,however, raises the issue of operability. At ultra-low supply voltages, the integrity of digital signals degrades dramatically due to the indifference between active and leakage currents. In addition, the system timing becomes more unpredictable as the impact of process and supply voltage variations being more significant at lower voltages. This paper presents a comparative study among three techniques for designing digital circuits operating at ultra-low voltages, i.e., Schmitt-triggered gate structure, delayinsensitive asynchronous logic, and Fully-Depleted Silicon-on-Insulator technology. Results show that despite the tradeoffs, all eight combinations of these techniques are viable for designing ultra-low voltage circuits. For a given application, the optimum circuit design can be selected from these combinations based on the lowest voltage, the dynamic range, the power budget, the performance requirement, and the available semiconductor process node.

  18. An Ultra Low Cost Wireless Communications Laboratory for Education and Research

    Science.gov (United States)

    Linn, Y.

    2012-01-01

    This paper presents an ultra-low-cost wireless communications laboratory that is based on a commercial off-the-shelf field programmable gate array (FPGA) development board that is both inexpensive and available worldwide. The total cost of the laboratory is under USD $200, but it includes complete transmission, channel emulation, reception…

  19. Novel thin film polymer foaming technique for low and ultra low-k dielectrics

    NARCIS (Netherlands)

    Krause, B.; Koops, G.H.; Vegt, van der N.F.A.; Wessling, M.; Wubbenhorst, M.; Turnhout, van J.

    2001-01-01

    The results presented show a novel route for the preparation of thin ultra-low-k polymer films based on commercial and "non-exotic" (non-expensive) polyimide by a foaming technique. Dependent on the glass transition temperature of the polyimide mechanically and thermally stable (> 300 °C) films havi

  20. A New Ultra-low Frequency Passive Vertical Vibration Isolation System

    Institute of Scientific and Technical Information of China (English)

    赵鹏飞; 黄玉盈; 唐孟希

    2002-01-01

    A new ultra-low frequency passive vertical vibration isolation system is constructed by connecting the torsion spring isolator with a reverse pendulum. The theoretical analysis shows that the new system can achieve a much longer resonant period and have a smaller size than the current torsion spring isolators with the same geometric parameters.

  1. A New Ultra-low Frequency Passive Vertical Vibration Isolation System

    Science.gov (United States)

    Zhao, Peng-Fei; Huang, Yu-Ying; Tang, Meng-Xi

    2002-02-01

    A new ultra-low frequency passive vertical vibration isolation system is constructed by connecting the torsion spring isolator with a reverse pendulum. The theoretical analysis shows that the new system can achieve a much longer resonant period and have a smaller size than the current torsion spring isolators with the same geometric parameters.

  2. A Comparative Study of Ultra-Low Voltage Digital Circuit Design

    Directory of Open Access Journals (Sweden)

    Aaron Arthurs,

    2012-06-01

    Full Text Available Ultra-low voltage digital circuit design is an active research area, especially for portable applications such as wearable electronics, intelligent remote sensors, implantable medical devices, and energy-harvesting systems. Due to their application scenarios and circuit components, two major goals for these systems are minimizing energy consumption and improving compatibility with low-voltage power supplies and analog components. The most effective solution to achieve these goals is to reduce the supply voltage, which,however, raises the issue of operability. At ultra-low supply voltages, the integrity of digital signals degrades dramatically due to the indifference between active and leakage currents. In addition, the system timing becomes more unpredictable as the impact of process and supply voltage variations being more significant at lower voltages. This paper presents a comparative study among three techniques for designing digital circuits operating at ultra-low voltages, i.e., Schmitt-triggered gate structure, delay insensitive asynchronous logic, and Fully-Depleted Silicon-on-Insulator technology. Results show that despite the trade offs, all eight combinations of these techniques are viable for designing ultra-low voltage circuits. For a given application, the optimum circuit design can be selected from these combinations based on the lowest voltage, the dynamic range, the power budget, the performance requirement, and the available semiconductor process node.

  3. The influence of ultra-low moisture content on the seed viability of rice in store

    Institute of Scientific and Technical Information of China (English)

    ZHIJuzhen; BIXinhua

    1994-01-01

    This paper deals with the influence of ultra-low moisture content and the rate of desiceation on rice seed viability and physiological property by desiccating using four kinds of desiooants (phosphorus pentoxide, calcium oxide, calcium chloride and silica gel) with different dosage.

  4. Ultra-low dose comprehensive cardiac CT imaging in a patient with acute myocarditis.

    Science.gov (United States)

    Tröbs, Monique; Brand, Michael; Achenbach, Stephan; Marwan, Mohamed

    2014-01-01

    The ability of contrast-enhanced CT to detect "late enhancement" in a fashion similar to magnetic resonance imaging has been previously reported. We report a case of acute myocarditis with coronary CT angiography as well as "late enhancement" imaging with ultra-low effective radiation dose.

  5. INTRAUTERINE HYPOXIA OF FETUS - INFLUENCE OF ULTRA-LOW DOSES OF ANTIOXIDANT (EXPERIMENTAL RESEARCH

    Directory of Open Access Journals (Sweden)

    ZARINA KHAYBULLINA

    2011-08-01

    Full Text Available Oxygensensing mechanisms have been developed to maintain cell and tissue homeostasis, as well as to adapt to the chronic lowoxygen condition, but intensive production of reactive oxygen species (ROS can cause cell destruction. Previous studies revealed that the hypoxia induces oxidative stress and neurodegeneration, which is associated with memory, behavioral, and learningeducation impairment in children. In the view of the abovestated concept, the study of influence of ultra low doses of antioxidant on ROS generation and activity of enzymes of antioxidant protection in a brain and blood at intrauterine hypoxia of a fetus appears appealing. The effect of Fenozan in ultra low doses was evaluated in the rats underwent intrauterine hypoxia. Research was made on white rats, 66 pregnant females and 279 infant rats (021 days. It was established, that chronic prenatal hypoxia is accompanied by accumulation of malondialdehyde in brain tissue, blood and subcellular fractions of a liver, with the subsequent spontaneous normalization of its maintenance by 21st day in a brain and blood.Fenozan injection in ultra low doses leads to appreciable decrease in MDA level and increase of the ROSscavenging enzymes at first in a brain and peripheral blood, and then in microsomal and mitochondrial fractions of the liver, that is the precondition for normalization of pathological process in earlier terms. Significance of this data argues that ultra low doses of Fenozan can be less invasive and effective in the treatment of chronic intrauterine hypoxia and suggest the directions for further research.

  6. Nanosized MX Precipitates in Ultra-Low-Carbon Ferritic/Martensitic Heat-Resistant Steels

    Science.gov (United States)

    Yin, Feng-Shi; Jung, Woo-Sang

    2009-02-01

    Nanosized MX precipitates in ultra-low-carbon ferritic/martensitic heat-resistant 9Cr-W-Mo-VNbTiN steels were characterized by transmission electron microscope (TEM) using carbon film replicas. The steels were prepared by vacuum induction melting followed by hot forging and rolling into plates. The plates were normalized at 1100 °C for 1 hour, cooled in air, and tempered at 700 °C for 1 hour. The results show that bimodal nanosized MX precipitates distribute densely and homogeneously in the matrix within martensitic lath after normalizing-and-tempering heat treatment. The larger nanosized MX precipitates with the size of 30 to 50 nm are rich in Nb, while the smaller ones with the size of about 10 nm contain less Nb but more V. Small addition of Ti causes an increase in the number of the larger nanosized MX precipitates. The total number density of the nanosized MX precipitates in the ultra-low-carbon ferritic/martensitic steels is measured to be over 300/ μm2, much higher than that in conventional ferritic/martensitic steels. Short-term creep test results show that the ultra-low-carbon ferritic/martensitic steels with high dense nanosized MX precipitates have much higher creep rupture strength than conventional ASME-P92 steel. The strength degradation of the ultra-low-carbon ferritic/martensitic heat-resistant steels during creep is also discussed in this article.

  7. Ultra-low level radon assays in gases

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin Ran [University College London, Gower Street, London, WC1E 6BT (United Kingdom)

    2015-08-17

    The SuperNEMO experiment aims to search for the neutrinoless double beta decay (0νβ β) to T{sub 1{sub /{sub 2}}}(0ν) > 10{sup 26} years, this corresponds to an effective neutrino mass of 50-100 meV. The extremely rare event rate means the minimisation of background is of critical concern. The stringent strategy instigated to ensure detector radiopurity is outlined here for all construction materials. In particular the large R&D programme undertaken to reach the challengingly low level of radon, < 0.15 mBq/m{sup 3}, required inside the SuperNEMO gaseous tracker will be detailed. This includes an experiment designed to measure radon diffusion through various materials. A “Radon Concentration Line” (RnCL) was developed to be used in conjunction with a state-of-the-art radon detector in order to achieve world leading sensitivity to {sup 222}Rn content in large gas volumes at the level of a few µBq/m{sup 3}. A radon purification system was developed and installed which has demonstrated radon suppression by several orders of magnitude depending on the carrier gas. This apparatus has now been commissioned and measurements of cylindered gas have been made to confirm radon suppression by a factor 20 when using nitrogen as the carrier gas. The results from measurements of radon content in various gases, used inside SuperNEMO, using the RnCL will be presented.

  8. Ultra Low Frequency (ULF) European multi station magnetic field analysis before and during the 2009 earthquake at L'Aquila regarding regional geotechnical information

    OpenAIRE

    Prattes, G.; Schwingenschuh, K.; Eichelberger, H. U.; Magnes, W.; Boudjada, M.; M. Stachel; Vellante, M.; U. Villante; Wesztergom, V.; Nenovski, P.

    2011-01-01

    This work presents ground based Ultra Low Frequency (ULF) magnetic field measurements in the frequency range from 10–15 mHz from 1 January 2008 to 14 April 2009. In this time period a strong earthquake series hit the Italian Abruzzo region around L'Aquila with the main stroke of magnitude M = 6.3 on 6 April 2009. In the frame of the South European Geomagnetic Array (SEGMA), a European collaboration runs ULF fluxgate instruments providing continuously magnetic field data re...

  9. Diffuse Surface Scattering in the Plasmonic Resonances of Ultra-Low Electron Density Nanospheres

    CERN Document Server

    Monreal, R Carmina; Apell, S Peter

    2015-01-01

    Localized surface plasmon resonances (LSPRs) have recently been identified in extremely diluted electron systems obtained by doping semiconductor quantum dots. Here we investigate the role that different surface effects, namely electronic spill-out and diffuse surface scattering, play in the optical properties of these ultra-low electron density nanosystems. Diffuse scattering originates from imperfections or roughness at a microscopic scale on the surface. Using an electromagnetic theory that describes this mechanism in conjunction with a dielectric function including the quantum size effect, we find that the LSPRs show an oscillatory behavior both in position and width for large particles and a strong blueshift in energy and an increased width for smaller radii, consistent with recent experimental results for photodoped ZnO nanocrystals. We thus show that the commonly ignored process of diffuse surface scattering is a more important mechanism affecting the plasmonic properties of ultra-low electron density ...

  10. Feasibility study of SiGHT: a novel ultra low background photosensor for low temperature operation

    CERN Document Server

    Wang, Yi; Fiorillo, Giuliana; Galbiati, Cristiano; Guan, Meng-Yun; Korga, George; Pantic, Emilija; Razeto, Alessandro; Renshaw, Andrew; Rossi, Biagio; Suvorov, Yury; Wang, Hanguo; Yang, Chang-Gen

    2016-01-01

    Rare event search experiments, such as those searching for dark matter and observations of neutrinoless double beta decay, require ultra low levels of radioactive background for unmistakable identification. In order to reduce the radioactive backgrounds of detectors used in these types of event searches, low background photosensors are required, as the physical size of these detectors become increasing larger, and hence the number of such photosensors used also increases rapidly. Considering that most dark matter and neutrinoless double beta decay experiments are turning towards using noble liquids as the target choice, liquid xenon and liquid argon for instance, photosensors that can work well at cryogenic temperatures are required, 165 K and 87 K for liquid xenon and liquid argon, respectively. The Silicon Geiger Hybrid Tube (SiGHT) is a novel photosensor designed specifically for use in ultra low background experiments operating at cryogenic temperatures. It is based on the proven photocathode plus silicon...

  11. A Novel Electrochemical Oxygen Sensor for Determination of Ultra-low Oxygen Contents in Molten Metal

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A novel electrochemical oxygen sensor has been developed by using La-Al2O3 as solid electrolyte and Cr+Cr2O3 as reference electrode. The sensor not only can be used as normal oxygen sensor but also as an ultra-low oxygen sensor. Especially, it is very sensitive to measure ultra-low oxygen in molten metal. For estimating the accuracy of La-Al2O3 oxygen sensor, two series of oxygen activities in molten iron at different oxygen contents and different temperature were measured by both La-Al2O3 oxygen sensor and ZrO2 oxygen sensor. The theoretical values of oxygen activities in molten iron (3.30%C, in mass fraction) at 1723K and 1745K were also evaluated for comparing the measuring results of two sensors. At last, the error of measurement for La-Al2O3 oxygen sensor was discussed too.

  12. CMOS circuits for electromagnetic vibration transducers interfaces for ultra-low voltage energy harvesting

    CERN Document Server

    Maurath, Dominic

    2015-01-01

    Chip-integrated power management solutions are a must for ultra-low power systems. This enables not only the optimization of innovative sensor applications. It is also essential for integration and miniaturization of energy harvesting supply strategies of portable and autonomous monitoring systems. The book particularly addresses interfaces for energy harvesting, which are the key element to connect micro transducers to energy storage elements. Main features of the book are: - A comprehensive technology and application review, basics on transducer mechanics, fundamental circuit and control design, prototyping and testing, up to sensor system supply and applications. - Novel interfacing concepts - including active rectifiers, MPPT methods for efficient tracking of DC as well as AC sources, and a fully-integrated charge pump for efficient maximum AC power tracking at sub-100µW ultra-low power levels. The chips achieve one of widest presented operational voltage range in standard CMOS technology: 0.44V to over...

  13. A flexible nanobrush pad for the chemical mechanical planarization of Cu/ultra-low-к materials

    Science.gov (United States)

    Han, Guiquan; Liu, Yuhong; Lu, Xinchun; Luo, Jianbin

    2012-10-01

    A new idea of polishing pad called flexible nanobrush pad (FNP) has been proposed for the low down pressure chemical mechanical planarization (CMP) process of Cu/ultra-low-к materials. The FNP was designed with a surface layer of flexible brush-like nanofibers which can `actively' carry nanoscale abrasives in slurry independent of the down pressure. Better planarization performances including high material removal rate, good planarization, good polishing uniformity, and low defectivity are expected in the CMP process under the low down pressure with such kind of pad. The FNP can be made by template-assisted replication or template-based synthesis methods, which will be driven by the development of the preparation technologies for ordered nanostructure arrays. The present work would potentially provide a new solution for the Cu/ultra-low-к CMP process.

  14. Ultra-low-frequency dust-electromagnetic modes in self-gravitating magnetized dusty plasmas

    Indian Academy of Sciences (India)

    A K Banerjee; M N Alam; A A Mamun

    2001-05-01

    Obliquely propagating ultra-low-frequency dust-electromagnetic waves in a self-gravitating, warm, magnetized, two fluid dusty plasma system have been investigated. Two special cases, namely, dust-Alfvén mode propagating parallel to the external magnetic field and dust-magnetosonic mode propagating perpendicular to the external magnetic field have also been considered. It has been shown that effects of self-gravitational field, dust fluid temperature, and obliqueness significantly modify the dispersion properties of these ultra-low-frequency dust-electromagnetic modes. It is also found that in parallel propagating dust-Alfvén mode these effects play no role, but in obliquely propagating dust-Alfvén mode or perpendicular propagating dust-magnetosonic mode the effect of self-gravitational field plays destabilizing role whereas the effect of dust/ion fluid temperature plays stabilizing role.

  15. An ultra low power ECG signal processor design for cardiovascular disease detection.

    Science.gov (United States)

    Jain, Sanjeev Kumar; Bhaumik, Basabi

    2015-08-01

    This paper presents an ultra low power ASIC design based on a new cardiovascular disease diagnostic algorithm. This new algorithm based on forward search is designed for real time ECG signal processing. The algorithm is evaluated for Physionet PTB database from the point of view of cardiovascular disease diagnosis. The failed detection rate of QRS complex peak detection of our algorithm ranges from 0.07% to 0.26% for multi lead ECG signal. The ASIC is designed using 130-nm CMOS low leakage process technology. The area of ASIC is 1.21 mm(2). This ASIC consumes only 96 nW at an operating frequency of 1 kHz with a supply voltage of 0.9 V. Due to ultra low power consumption, our proposed ASIC design is most suitable for energy efficient wearable ECG monitoring devices.

  16. A flexible nanobrush pad for the chemical mechanical planarization of Cu/ultra-low-к materials.

    Science.gov (United States)

    Han, Guiquan; Liu, Yuhong; Lu, Xinchun; Luo, Jianbin

    2012-10-30

    A new idea of polishing pad called flexible nanobrush pad (FNP) has been proposed for the low down pressure chemical mechanical planarization (CMP) process of Cu/ultra-low-к materials. The FNP was designed with a surface layer of flexible brush-like nanofibers which can 'actively' carry nanoscale abrasives in slurry independent of the down pressure. Better planarization performances including high material removal rate, good planarization, good polishing uniformity, and low defectivity are expected in the CMP process under the low down pressure with such kind of pad. The FNP can be made by template-assisted replication or template-based synthesis methods, which will be driven by the development of the preparation technologies for ordered nanostructure arrays. The present work would potentially provide a new solution for the Cu/ultra-low-к CMP process.

  17. Development of ultra-low impedance Through-wafer Micro-vias

    Energy Technology Data Exchange (ETDEWEB)

    Finkbeiner, F.M. E-mail: fmf@lheapop.gsfc.nasa.gov; Adams, C.; Apodaca, E.; Chervenak, J.A.; Fischer, J.; Doan, N.; Li, M.J.; Stahle, C.K.; Brekosky, R.P.; Bandler, S.R.; Figueroa-Feliciano, E.; Lindeman, M.A.; Kelley, R.L.; Saab, T.; Talley, D.J

    2004-03-11

    Concurrent with our microcalorimeter array fabrication for Constellation-X technology development, we are developing ultra-low impedance Through-Wafer Micro-Vias (TWMV) as electrical interconnects for superconducting circuits. The TWMV will enable the electrical contacts of each detector to be routed to contacts on the backside of the array. There, they can be bump-bonded to a wiring fan-out board which interfaces with the front-end Superconducting Quantum Interference Device readout. We are concentrating our developmental efforts on ultra-low impedance copper and superconducting aluminum TWMV in 300-400 micron thick silicon wafers. For both schemes, a periodic pulse-reverse electroplating process is used to fill or coat micron-scale through-wafer holes of aspect ratios up to 20. Here we discuss the design, fabrication process, and recent electro-mechanical test results of Al and Cu TWMV at room and cryogenic temperatures.

  18. Ultra-low phase noise all-optical microwave generation setup based on commercial devices

    CERN Document Server

    Didier, A; Grop, S; Dubois, B; Bigler, E; Rubiola, E; Lacroûte, C; Kersalé, Y

    2015-01-01

    In this paper, we present a very simple design based on commercial devices for the all-optical generation of ultra-low phase noise microwave signals. A commercial, fibered femtosecond laser is locked to a laser that is stabilized to a commercial ULE Fabry-Perot cavity. The 10 GHz microwave signal extracted from the femtosecond laser output exhibits a single sideband phase noise $\\mathcal{L}(f)=-104 \\ \\mathrm{dBc}/\\mathrm{Hz}$ at 1 Hz Fourier frequency, at the level of the best value obtained with such "microwave photonics" laboratory experiments \\cite{Fortier2011}. Close-to-the-carrier ultra-low phase noise microwave signals will now be available in laboratories outside the frequency metrology field, opening up new possibilities in various domains.

  19. Synthesis and characterization of flexible and high-temperature resistant polyimide aerogel with ultra-low dielectric constant

    Directory of Open Access Journals (Sweden)

    X. M. Zhang

    2016-10-01

    Full Text Available A polyimide (PI aerogel with excellent combined thermal and dielectric properties was successfully prepared by the polycondensation of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA, 5-amino-2-(4-aminophenylbenzoxazole (APBO and octa(amino-phenylsilsesquioxane (OAPS crosslinker, followed by a supercritical carbon dioxide (scCO2 drying treatment. The developed PI aerogel exhibited an ultra-low dielectric constant (k of 1.15 at a frequency of 2.75 GHz, a volume resistivity of 5.45·1014 Ω·cm, and a dielectric strength of 132 kV/cm. The flexible PI aerogel exhibited an openpore microstructure consisting of three-dimensional network with tangled nanofibers morphology with a porosity of 85.6% (volume ratio, an average pore diameter of 19.2 nm, and a Brunauer-Emmet-Teller (BET surface area of 428.6 m2/g. In addition, the PI aerogel showed excellent thermal stability with a glass transition temperature (Tg of 358.3 °C, a 5% weight loss temperature over 500 °C, and a residual weight ratio of 66.7% at 750 °C in nitrogen.

  20. Effectiveness of Biodiesel from Various Tropical Oil Crops on Lubricity Improvement of Ultra Low Sulfur Diesel (ULSD)

    Energy Technology Data Exchange (ETDEWEB)

    Chollacoop, Nuwong; Topaiboul, Subongkoj; Goodwin, Vituruch (Bioenergy Group, National Metal and Materials Technology Center (MTEC), Thailand Science Park, Pathumthani, 12120 (Thailand)). e-mail: nuwongc@mtec.or.th

    2008-10-15

    Ultra low sulfur diesel (ULSD) has been introduced worldwide with an aim to reduce emission. Since the desulfurization process for ULSD inadvertently reduces its lubricity, lubricity additive is needed. Biodiesel emerges as a potential candidate due to its excellent lubricity property and little sulfur content. In the present study, biodiesel from various energy crops available in Thailand was added at various amounts to ULSD to test the lubricity according to the CEC-F-06-A-96 standard (using High-Frequency Reciprocating Rig: HFRR [1]). It was found that when biodiesel from crude palm, jatropha, soybean, coconut, sunflower, rice, corn and sesame oils of less than 1% (by volume) is additized to ULSD, the lubricity is improved to meet the diesel standard. Further addition beyond 2% (by volume) does not improve lubricity remarkably, where the lubrication seems to saturate. Biodiesel improves lubricity property by film formation preventing mechanical contact between the rubbing surfaces, and the effectiveness varies among different feedstock oils. Biodiesel from crude palm oil, jatropha oil and coconut oil seemingly are superior lubricity additives in ULSD than that from soybean oil, sunflower oil, rice oil, corn oil and sesame oil. Keywords: biodiesel, bio-lubricants, palm oil, sunflower oil

  1. Study of ultra-low emittance design for Spear3 using longitudinal gradient dipole

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M. -H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Safranek, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-09-24

    Since its 2003 construction, the SPEAR3 synchrotron light source at SLAC has continuously improved its performance by raising beam current, top-off injection, and smaller emittance. This makes SPEAR3 one of the most productive light sources in the world. Now to further enhance the performance of SPEAR3, we are looking into the possibility of converting SPEAR3 to an ultra-low emittance storage ring within its site constraint.

  2. Component Development to Accelerate Commercial Implementation of Ultra-Low Emissions Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, Jon; Berry, Brian; Lundberg, Kare; Anson, Orris

    2003-03-31

    This final report describes a 2000-2003 program for the development of components and processes to enhance the commercialization of ultra-low emissions catalytic combustion in industrial gas turbines. The range of project tasks includes: development of more durable, lower-cost catalysts and catalytic combustor components; development and design of a catalytic pre-burner and a catalytic pilot burner for gas turbines, and on-site fuel conversion processing for utilization of liquid fuel.

  3. A flexible nanobrush pad for the chemical mechanical planarization of Cu/ultra-low-к materials

    OpenAIRE

    Han, Guiquan; Liu, Yuhong; Lu, Xinchun; Luo, Jianbin

    2012-01-01

    A new idea of polishing pad called flexible nanobrush pad (FNP) has been proposed for the low down pressure chemical mechanical planarization (CMP) process of Cu/ultra-low-к materials. The FNP was designed with a surface layer of flexible brush-like nanofibers which can ‘actively’ carry nanoscale abrasives in slurry independent of the down pressure. Better planarization performances including high material removal rate, good planarization, good polishing uniformity, and low defectivity are ex...

  4. Effect of Si-Al compounds on fire properties of ultra-low density fiberboard

    OpenAIRE

    Min Niu; Olle Hagman; Xiaodong Wang; Yongqun Xie; Olov Karlsson; LiLi Cai

    2014-01-01

    An ultra-low density fiberboard was made of plant fiber using a liquid frothing approach. The inflammability of the plant fiber limited its application as a candidate for building insulation materials and packaging buffering materials. Si-Al compounds were introduced into the foaming system because of the high temperature resistance of Si and Al compounds. The results from energy-dispersive spectroscopy suggested that the Si and Al relatively evenly covered the surface of the fibers, and thei...

  5. How Many Ultra-Low Delta-v Near Earth Objects Remain Undiscovered? Implications for missions.

    Science.gov (United States)

    Elvis, Martin; Ranjan, Sukrit; Galache, Jose Luis; Murphy, Max

    2015-08-01

    The past decade has witnessed considerable growth of interest in missions to Near-Earth Objects (NEOs). NEOs are considered prime targets for manned and robotic missions, for both scientific objectives as well as in-situ resource utilization including harvesting of water for propellant and life support and mining of high-value elements for sale on Earth. Appropriate targets are crucial to such missions. Hence, ultra-low delta-v mission targets are strongly favored. Some mission architectures rely on the discovery of more ultra-low delta-v NEOs. In fact the approved and executed NEO missions have all targeted asteroids with ultra-low LEO to asteroid rendezvous delta-v orbits using a modified Shoemaker-Helin (S-H) formalism that empirically removes biases found comparing S-H with the results from NHATS. The median delta-v of the known NEOs is 7.3 km/s, the median delta-v predicted by our NEO model is 9.8 km/s, suggesting that undiscovered objects are biased to higher delta-v. The survey of delta-v 300 m. However, there are tens of thousands of objects with delta-v <10.3 km/s to be discovered in the D = 50 - 300 m size class (H = 20.4 - 24.3). Our work suggests that there are 100 yet-undiscovered NEOs with delta-v < 5:8 km/s, and 1000 undiscovered NEOs with v < 6.3 km/s. We conclude that, even with complete NEO surveys, the selection of good (i.e. ultra-low delta-v) mission targets is limited given current propulsion technology. Visiting the full range of NEO sub-types will likely require improved propulsion systems.

  6. Sex hormone-binding globulin and antithrombin III activity in women with oral ultra-low-dose estradiol.

    Science.gov (United States)

    Matsui, Sumika; Yasui, Toshiyuki; Kasai, Kana; Keyama, Kaoru; Yoshida, Kanako; Kato, Takeshi; Uemura, Hirokazu; Kuwahara, Akira; Matsuzaki, Toshiya; Irahara, Minoru

    2017-03-20

    Oral oestrogen increases the risk of venous thromboembolism (VTE) and increases production of sex hormone-binding globulin (SHBG) in a dose-dependent manner. SHBG has been suggested to be involved in venous thromboembolism. We examined the effects of oral ultra-low-dose oestradiol on circulating levels of SHBG and coagulation parameters, and we compared the effects to those of transdermal oestradiol. Twenty women received oral oestradiol (500 μg) every day (oral ultra-low-dose group) and 20 women received a transdermal patch (50 μg) as a transdermal group. In addition, the women received dydrogesterone continuously (5 mg) except for women who underwent hysterectomy. Circulating SHBG, antithrombin III (ATIII) activity, d-dimer, thrombin-antithrombin complex and plasmin-α2 plasmin inhibitor complex were measured before and 3 months after the start of treatment. SHBG was significantly increased at 3 months in the oral ultra-low-dose group, but not in the transdermal group. However, percent changes in SHBG were not significantly different between the two groups. In both groups, ATIII was significantly decreased at 3 months. In conclusion, even ultra-low-dose oestradiol orally increases circulating SHBG level. However, the magnitude of change in SHBG caused by oral ultra-low-dose oestradiol is small and is comparable to that caused by transdermal oestradiol. Impact statement Oral oestrogen replacement therapy increases production of SHBG which may be related to increase in VTE risk. However, the effect of oral ultra-low-dose oestradiol on SHBG has not been clarified. Even ultra-low-dose oestradiol orally increases circulating SHBG levels, but the magnitude of change in SHBG caused by oral ultra-low-dose oestradiol is small and is comparable to that caused by transdermal oestradiol. VTE risk in women receiving oral ultra-low-dose oestradiol may be comparable to that in women receiving transdermal oestradiol.

  7. CASCADES: An Ultra-Low-Background Germanium Crystal Array at Pacific Northwest National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Keillor, Martin E.; Aalseth, Craig E.; Day, Anthony R.; Erikson, Luke E.; Fast, James E.; Glasgow, Brian D.; Hoppe, Eric W.; Hossbach, Todd W.; Hyronimus, Brian J.; Miley, Harry S.; Myers, Allan W.; Seifert, Allen; Stavenger, Timothy J.

    2011-07-14

    State-of-the-art treaty verification techniques, environmental surveillance, and physics experiments require increased sensitivity for detecting and quantifying radionuclides of interest. This can be accomplished with new detector designs that establish high detection efficiency and reduced instrument backgrounds. Current research is producing an intrinsic germanium (HPGe) array designed for high detection efficiency, ultra-low-background performance, and sensitive {gamma}-{gamma} coincidence detection. The system design is optimized to accommodate filter paper samples, e.g., samples collected by the Radionuclide Aerosol Sampler/Analyzer. The system will provide high sensitivity for weak collections on atmospheric filter samples (e.g., < 10{sup 5} fissions), as well as offering the potential to gather additional information from higher activity filters using gamma cascade coincidence detection. The first of two HPGe crystal arrays in ultra-low-background vacuum cryostats has been assembled, with the second in progress. Traditional methods for constructing ultra-low-background detectors were followed, including use of materials known to be low in radioactive contaminants, use of ultra-pure reagents, and clean room assembly. The cryostat is constructed mainly from copper electroformed into near-final geometry at Pacific Northwest National Laboratory. Details of the detector assembly and initial background and spectroscopic measurement results are presented; also a description of the custom analysis package used by this project is given.

  8. Fluctuation-induced dynamics of multiphase liquid jets with ultra-low interfacial tension.

    Science.gov (United States)

    Sauret, Alban; Spandagos, Constantinos; Shum, Ho Cheung

    2012-09-21

    Control of fluid dynamics at the micrometer scale is essential to emulsion science and materials design, which is ubiquitous in everyday life and is frequently encountered in industrial applications. Most studies on multiphase flow focus on oil-water systems with substantial interfacial tension. Advances in microfluidics have enabled the study of multiphase flow with more complex dynamics. Here, we show that the evolution of the interface in a jet surrounded by a co-flowing continuous phase with an ultra-low interfacial tension presents new opportunities to the control of flow morphologies. The introduction of a harmonic perturbation to the dispersed phase leads to the formation of interfaces with unique shapes. The periodic structures can be tuned by controlling the fluid flow rates and the input perturbation; this demonstrates the importance of the inertial effects in flow control at ultra-low interfacial tension. Our work provides new insights into microfluidic flows at ultra-low interfacial tension and their potential applications.

  9. Ultra-Low Delta-v Objects and the Human Exploration of Asteroids

    CERN Document Server

    Elvis, Martin; Hoffman, Jeffrey A; Binzel, Richard P

    2011-01-01

    Missions to near-Earth objects (NEOs) are key destinations in NASA's new "Flexible Path" approach. NEOs are also of interest for science, for the hazards they pose, and for their resources. We emphasize the importance of ultra-low delta-v from LEO to NEO rendezvous as a target selection criterion, as this choice can greatly increase the payload to the NEO. Few such ultra-low delta-v NEOs are currently known; only 65 of the 6699 known NEOs (March2010) have delta-v <4.5 km/s, 2/3 of typical LEO-NEO delta-v. Even these are small and hard to recover. Other criteria - short transit times, long launch windows, a robust abort capability, and a safe environment for proximity operations - will further limit the list of accessible objects. Potentially there are at least an order of magnitude more ultra-low delta v NEOs but, to find them all on a short enough timescale (before 2025) requires a dedicated survey in the optical or mid-IR, optimally from a Venus-like orbit because of the short synodic period for NEOs in ...

  10. Early Site Permit Demonstration Program: Guidelines for determining design basis ground motions. Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    1993-03-18

    This report develops and applies a methodology for estimating strong earthquake ground motion. The motivation was to develop a much needed tool for use in developing the seismic requirements for structural designs. An earthquake`s ground motion is a function of the earthquake`s magnitude, and the physical properties of the earth through which the seismic waves travel from the earthquake fault to the site of interest. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Eastern North America is a stable continental region, having sparse earthquake activity with rare occurrences of large earthquakes. While large earthquakes are of interest for assessing seismic hazard, little data exists from the region to empirically quantify their effects. The focus of the report is on the attributes of ground motion in Eastern North America that are of interest for the design of facilities such as nuclear power plants. This document, Volume II, contains Appendices 2, 3, 5, 6, and 7 covering the following topics: Eastern North American Empirical Ground Motion Data; Examination of Variance of Seismographic Network Data; Soil Amplification and Vertical-to-Horizontal Ratios from Analysis of Strong Motion Data From Active Tectonic Regions; Revision and Calibration of Ou and Herrmann Method; Generalized Ray Procedure for Modeling Ground Motion Attenuation; Crustal Models for Velocity Regionalization; Depth Distribution Models; Development of Generic Site Effects Model; Validation and Comparison of One-Dimensional Site Response Methodologies; Plots of Amplification Factors; Assessment of Coupling Between Vertical & Horizontal Motions in Nonlinear Site Response Analysis; and Modeling of Dynamic Soil Properties.

  11. Deposition from Ultra-low Volume Application of Public Health Insecticides in a Hot Desert Environment

    Science.gov (United States)

    2015-06-01

    apply resmethrin (ScourgeH; Bayer AG, Research Triangle Park, NC; 4.14% AI + 12.42% PBO), malathion (Fyfanon; Cheminova Inc., Wayne, NJ; 96.5% AI...Rowton ED, Blount K, Ploch J, Hopkins G, Raymond JW, O’Guinn ML, Lee JS, Weina PJ. 2006. Impact of phlebotomine sand flies on U.S. military operations at

  12. Environmental Fate Model for Ultra-Low-Volume Insecticide Applications Used for Adult Mosquito Management

    Science.gov (United States)

    2012-01-01

    drift hazard (Hewitt, 2008; Teske et al., 2000). Little is currently known about the deposition and drift of small droplets such as those used during...ULV applications for adult mosquito management ( Teske et al., 2000). Droplets smaller than 50 μm have very low settling velocities, and have similar...risk and regulatory assessments have used models like ISCST3, AgDrift® (Stewart Agricultural Research Services, Macon, MO, USA) ( Teske et al., 2002), and

  13. Isotope Brayton ground demonstration testing and flight qualification. Volume 1. Technical program

    Energy Technology Data Exchange (ETDEWEB)

    1974-12-09

    A program is proposed for the ground demonstration, development, and flight qualification of a radioisotope nuclear heated dynamic power system for use on space missions beginning in the 1980's. This type of electrical power system is based upon and combines two aerospace technologies currently under intense development; namely, the MHW isotope heat source and the closed Brayton cycle gas turbine. This power system represents the next generation of reliable, efficient economic electrical power equipment for space, and will be capable of providing 0.5 to 2.0 kW of electric power to a wide variety of spacecraft for earth orbital and interplanetary missions. The immediate design will be based upon the requirements for the Air Force SURVSATCOM mission. The proposal is presented in three volumes plus an Executive Summary. This volume describes the tasks in the technical program.

  14. Estimating Stand Volume and Above-Ground Biomass of Urban Forests Using LiDAR

    Directory of Open Access Journals (Sweden)

    Vincenzo Giannico

    2016-04-01

    Full Text Available Assessing forest stand conditions in urban and peri-urban areas is essential to support ecosystem service planning and management, as most of the ecosystem services provided are a consequence of forest stand characteristics. However, collecting data for assessing forest stand conditions is time consuming and labor intensive. A plausible approach for addressing this issue is to establish a relationship between in situ measurements of stand characteristics and data from airborne laser scanning (LiDAR. In this study we assessed forest stand volume and above-ground biomass (AGB in a broadleaved urban forest, using a combination of LiDAR-derived metrics, which takes the form of a forest allometric model. We tested various methods for extracting proxies of basal area (BA and mean stand height (H from the LiDAR point-cloud distribution and evaluated the performance of different models in estimating forest stand volume and AGB. The best predictors for both models were the scale parameters of the Weibull distribution of all returns (except the first (proxy of BA and the 95th percentile of the distribution of all first returns (proxy of H. The R2 were 0.81 (p < 0.01 for the stand volume model and 0.77 (p < 0.01 for the AGB model with a RMSE of 23.66 m3·ha−1 (23.3% and 19.59 Mg·ha−1 (23.9%, respectively. We found that a combination of two LiDAR-derived variables (i.e., proxy of BA and proxy of H, which take the form of a forest allometric model, can be used to estimate stand volume and above-ground biomass in broadleaved urban forest areas. Our results can be compared to other studies conducted using LiDAR in broadleaved forests with similar methods.

  15. Finite Volume Based Computer Program for Ground Source Heat Pump System

    Energy Technology Data Exchange (ETDEWEB)

    Menart, James A. [Wright State University

    2013-02-22

    This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled ?Finite Volume Based Computer Program for Ground Source Heat Pump Systems.? The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump

  16. Recovery Act: Finite Volume Based Computer Program for Ground Source Heat Pump Systems

    Energy Technology Data Exchange (ETDEWEB)

    James A Menart, Professor

    2013-02-22

    This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled Finite Volume Based Computer Program for Ground Source Heat Pump Systems. The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump. The

  17. Limits of Ultra-Low Dose CT Attenuation Correction for PET/CT.

    Science.gov (United States)

    Xia, Ting; Alessio, Adam M; Kinahan, Paul E

    2010-01-29

    We present an analysis of the effects of ultra-low dose X-ray computerized tomography (CT) based attenuation correction for positron emission tomography (PET). By ultra low dose we mean less than approximately 5 mAs or 0.5 mSv total effective whole body dose. The motivation is the increased interest in using respiratory motion information acquired during the CT scan for both phase-matched CT-based attenuation correction and for motion estimation. Since longer duration CT scans are desired, radiation dose to the patient can be a limiting factor. In this study we evaluate the impact of reducing photon flux rates in the CT data on the reconstructed PET image by using the CATSIM simulation tool for the CT component and the ASIM simulation tool for the PET component. The CT simulation includes effects of the x-ray tube spectra, beam conditioning, bowtie filter, detector noise, and bean hardening correction. The PET simulation includes the effect of attenuation and photon counting. Noise and bias in the PET image were evaluated from multiple realizations of test objects. We show that techniques can be used to significantly reduce the mAs needed for CT based attenuation correction if the CT is not used for diagnostic purposes. The limiting factor, however, is not the noise in the CT image but rather the bias introduced by CT sinogram elements with no detected flux. These results constrain the methods that can be used to lower CT dose in a manner suitable for attenuation correction of PET data. We conclude that ultra-low-dose CT for attenuation correction of PET data is feasible with current PET/CT scanners.

  18. Experimental investigation on regulated and unregulated emissions of a diesel engine fueled with ultra-low sulfur diesel fuel blended with biodiesel from waste cooking oil.

    Science.gov (United States)

    Di, Yage; Cheung, C S; Huang, Zuohua

    2009-01-01

    Experiments were conducted on a 4-cylinder direct-injection diesel engine using ultra-low sulfur diesel, bi oesel and their blends, to investigate the regulated and unregulated emissions of the engine under five engine loads at an engine speed of 1800 rev/min. Blended fuels containing 19.6%, 39.4%, 59.4% and 79.6% by volume of biodiesel, corresponding to 2%, 4%, 6% and 8% by mass of oxygen in the blended fuel, were used. Biodiesel used in this study was converted from waste cooking oil. The following results are obtained with an increase of biodiesel in the fuel. The brake specific fuel consumption and the brake thermal efficiency increase. The HC and CO emissions decrease while NO(x) and NO(2) emissions increase. The smoke opacity and particulate mass concentrations reduce significantly at high engine load. In addition, for submicron particles, the geometry mean diameter of the particles becomes smaller while the total number concentration increases. For the unregulated gaseous emissions, generally, the emissions of formaldehyde, 1,3-butadiene, toluene, xylene decrease, however, acetaldehyde and benzene emissions increase. The results indicate that the combination of ultra-low sulfur diesel and biodiesel from waste cooking oil gives similar results to those in the literature using higher sulfur diesel fuels and biodiesel from other sources.

  19. Ultra-low-field NMR relaxation and diffusion measurements using an optical magnetometer.

    Science.gov (United States)

    Ganssle, Paul J; Shin, Hyun D; Seltzer, Scott J; Bajaj, Vikram S; Ledbetter, Micah P; Budker, Dmitry; Knappe, Svenja; Kitching, John; Pines, Alexander

    2014-09-08

    Nuclear magnetic resonance (NMR) relaxometry and diffusometry are important tools for the characterization of heterogeneous materials and porous media, with applications including medical imaging, food characterization and oil-well logging. These methods can be extremely effective in applications where high-resolution NMR is either unnecessary, impractical, or both, as is the case in the emerging field of portable chemical characterization. Here, we present a proof-of-concept experiment demonstrating the use of high-sensitivity optical magnetometers as detectors for ultra-low-field NMR relaxation and diffusion measurements.

  20. Exploration of magnetic memory for ultra low-power systems-on-chip

    OpenAIRE

    Patrigeon, Guillaume; Senni, Sophiane; Benoit, Pascal; Torres, Lionel

    2017-01-01

    National audience; Memories are currently a real bottleneck to design high speed, low area and energy-efficient systems-on-chip (SoC). An important proportion of total power is spent on memory systems. Ultra low-power (ULP) SoC often use different memory technologies to keep the advantages of each one (area, energy consumption, latency and non-volatility), however there are still penalties and this add more complexity at every development levels. MRAM (Magnetic Random Access Memory) is seen a...

  1. Simulations of electron avalanches in an ultra-low-background proportional counter

    Science.gov (United States)

    Robinson, John W.; Aalseth, Craig; Dion, Michael P.; Overman, Cory; Seifert, Allen; VanDevender, Brent

    2016-02-01

    New classes have been added to the simulation package Garfield++ to import the potential and electric field solutions generated by ANSYS ® MaxwellTM v.16. Using these tools we report results on the simulation of electron avalanches and induced signal waveforms in comparison to experimental data of the ultra-low-background gas proportional counters being developed at Pacific Northwest National Laboratory. Furthermore, an improved mesh search algorithm based on Delaunay triangulation was implemented and provided at least a three order of magnitude time savings when compared to the built-in point-location search class of Garfield++.

  2. Simultaneous measurement of tritium and radiocarbon by ultra-low-background proportional counting.

    Science.gov (United States)

    Mace, Emily; Aalseth, Craig; Alexander, Tom; Back, Henning; Day, Anthony; Hoppe, Eric; Keillor, Martin; Moran, Jim; Overman, Cory; Panisko, Mark; Seifert, Allen

    2016-12-21

    Use of ultra-low-background capabilities at Pacific Northwest National Laboratory provide enhanced sensitivity for measurement of low-activity sources of tritium and radiocarbon using proportional counters. Tritium levels are nearly back to pre-nuclear test backgrounds (~2-8 TU in rainwater), which can complicate their dual measurement with radiocarbon due to overlap in the beta decay spectra. We present results of single-isotope proportional counter measurements used to analyze a dual-isotope methane sample synthesized from ~120mg of H2O and present sensitivity results.

  3. Ultra-Low Power Fiber-Coupled Gallium Arsenide Photonic Crystal Cavity Electro-Optical Modulator

    Science.gov (United States)

    2011-04-11

    200 nA corresponding to voltages of 0, 0.67, and 1 V (inset of Fig. 2(b)). As can be seen, the cavity resonance blueshifts monotonically even for...these ultra- low injection levels. In fact, 50% of the blueshift occurs in the first 20 nA of injection before saturating at approximately 200 nA (Fig...with a better MBE growth method as minimal leakage current was observed for similar devices in [13]. Nonetheless, the total blueshift of 110 pm is

  4. Ultra low bending loss equiangular spiral photonic crystal fibers in the terahertz regime

    Directory of Open Access Journals (Sweden)

    Arti Agrawal

    2012-06-01

    Full Text Available An Equiangular Spiral Photonic Crystal Fiber (ES-PCF design in Topas® for use in the Terahertz regime is presented. The design shows ultra low bending loss and very low confinement loss compared to conventional Hexagonal PCF (H-PCF. The ES-PCF has excellent modal confinement properties, together with several parameters to allow the optimization of the performance over a range of important characteristics. A full vector Finite Element simulation has been used to characterize the design which can be fabricated by a range of techniques including extrusion and drilling.

  5. Planar Hall ring sensor for ultra-low magnetic moment sensing

    Science.gov (United States)

    Hung, Tran Quang; Terki, Ferial; Kamara, Souleymanne; Kim, Kunwoo; Charar, Salam; Kim, CheolGi

    2015-04-01

    The field sensitivity of a planar Hall effect (PHE) micro-ring type biosensor has been investigated as a function of magnetizing angle of the sensor material, for the sensing of low magnetic moment superparamagnetic labels. The field sensitivity is maximal at a magnetizing angle of α = 20°. At this optimized magnetizing angle, the field sensitivity of a PHE sensor is about 3.6 times higher than that measured at the conventional configuration, α = 90°. This optimization enables the PHE-ring sensor to detect superparamagnetic biolabels with ultra-low magnetic moments down to 4 × 10-13 emu.

  6. Ultra-low-loss inverted taper coupler for silicon-on-insulator ridge waveguide

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Ou, Haiyan;

    2010-01-01

    An ultra-low-loss coupler for interfacing a silicon-on-insulator ridge waveguide and a single-mode fiber in both polarizations is presented. The inverted taper coupler, embedded in a polymer waveguide, is optimized for both the transverse-magnetic and transverse-electric modes through tapering...... the width of the silicon-on-insulator waveguide from 450 nm down to less than 15 nm applying a thermal oxidation process. Two inverted taper couplers are integrated with a 3-mm long silicon-on-insulator ridge waveguide in the fabricated sample. The measured coupling losses of the inverted taper coupler...

  7. Ultra-low-voltage-trigger thyristor for on-chip ESD protection without extra process cost

    Science.gov (United States)

    Yi, Shan; Jun, He; Wenyi, Huang

    2009-07-01

    A new thyristor is proposed and realized in the foundry's 0.18-μm CMOS process for electrostatic discharge (ESD) protection. Without extra mask layers or process steps, the new ultra-low-voltage-trigger thyristor (ULVT thyristor) has a trigger voltage as low as 6.7 V and an ESD robustness exceeding 50 mA/μm, which enables effective ESD protection. Compared with the traditional medium-voltage-trigger thyristor (MVT thyristor), the new structure not only has a lower trigger voltage, but can also provide better ESD protection under both positive and negative ESD zapping conditions.

  8. Ultra-low-voltage-trigger thyristor for on-chip ESD protection without extra process cost

    Energy Technology Data Exchange (ETDEWEB)

    Shan Yi [Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); He Jun; Huang Wenyi, E-mail: iamshanyi@163.co, E-mail: yi.shan@gracesemi.co [Grace Semiconductor Manufacturing Corporation, Shanghai 201203 (China)

    2009-07-15

    A new thyristor is proposed and realized in the foundry's 0.18-{mu}m CMOS process for electrostatic discharge (ESD) protection. Without extra mask layers or process steps, the new ultra-low-voltage-trigger thyristor (ULVT thyristor) has a trigger voltage as low as 6.7 V and an ESD robustness exceeding 50 mA/{mu}m, which enables effective ESD protection. Compared with the traditional medium-voltage-trigger thyristor (MVT thyristor), the new structure not only has a lower trigger voltage, but can also provide better ESD protection under both positive and negative ESD zapping conditions.

  9. Specifications of the octupole magnets required for the ATF2 ultra-low ß* lattice

    Energy Technology Data Exchange (ETDEWEB)

    Marin, E.; /SLAC; Modena, M.; /CERN; Tauchi, T.; Terunuma, N.; /KEK, Tsukuba; Tomas, R.; /CERN; White, G.R.; /SLAC

    2014-05-28

    The Accelerator Test Facility 2 (ATF2) aims to test the novel chromaticity correction for higher chromaticity lattices as the one of CLIC. To this end the ATF2 ultra-low ß* lattice is designed to vertically focus the beam at the focal point or usually referred to as interaction point (IP), down to 23 nm. However when the measured multipole components of the ATF2 magnets are considered in the simulations, the evaluated spot sizes at the IP are well above the design value. The designed spot size is effectively recovered by inserting a pair of octupole magnets. In this note we address the technical specifications required for these octupole magnets.

  10. Ultra-Low-Energy Germanium Detector for Neutrino-Nucleus Coherent Scattering and Dark Matter Searches

    CERN Document Server

    Wong, Henry T

    2008-01-01

    The status and plans of a research program on the development of ultra-low-energy germanium detectors with sub-keV sensitivities are reported. We survey the scientific goals which include the observation of neutrino-nucleus coherent scattering, the studies of neutrino magnetic moments, as well as the searches of WIMP dark matter. In particular, a threshold of 100-200 eV and a sub-keV background comparable to underground experiments were achieved with prototype detectors. New limits were set for WIMPs with mass between 3-6 GeV. The prospects of the realization of full-scale experiments are discussed.

  11. High excitation power photoluminescence studies of ultra-low density GaAs quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Sonnenberg, D.; Graf, A.; Paulava, V.; Heyn, Ch.; Hansen, W. [Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg (Germany)

    2013-12-04

    We fabricate GaAs epitaxial quantum dots (QDs) by filling of self-organized nanoholes in AlGaAs. The QDs are fabricated under optimized process conditions and have ultra-low density in the 10{sup 6} cm{sup −2} regime. At low excitation power the optical emission of single QDs exhibit sharp excitonic lines, which are attributed to the recombination of excitonic and biexcitonic states. High excitation power measurements reveal surprisingly broad emission lines from at least six QD shell states.

  12. Multi-sensor system for simultaneous ultra-low-field MRI and MEG

    CERN Document Server

    Zotev, V S; Matlachov, A N; Mosher, J C; Newman, S G; Sandin, H J; Urbaitis, A V; Volegov, P L

    2006-01-01

    Magnetoencephalography (MEG) and magnetic resonance imaging at ultra-low fields (ULF MRI) are two methods based on the ability of SQUID (superconducting quantum interference device) sensors to detect femtotesla magnetic fields. Combination of these methods will allow simultaneous functional (MEG) and structural (ULF MRI) imaging of the human brain. In this paper, we report the first implementation of a multi-sensor SQUID system designed for both MEG and ULF MRI. We present a multi-channel image of a human hand obtained at 46 microtesla field, as well as results of auditory MEG measurements with the new system.

  13. Ultrastructural Study on Ultra-Low Frequency Electromagnetic Fields and Transfer Factor Effects on Skin Ulcers

    Science.gov (United States)

    Cadena, M. S. Reyes; Chapul, L. Sánchez; Pérez, Javiér; García, M. N. Jiménez; López, M. A. Jiménez; Espíndola, M. E. Sánchez; Perez, R. Paniagua; Hernández, N. A.; Paniagua, G.; Uribe, F.; Nava, J. J. Godina; Segura, M. A. Rodríguez

    2008-08-01

    We determined the effect of 120Hz ultra low frequency electromagnetic field (ELF) on the healing process of skin in 20 Wistar rats distributed in four groups in which chronic dermal ulcers had been produced. The first two groups received a dose of the transfer factor and interferon-beta (IFN-β) every 24 h during 12 days. The third group (positive control) received only electromagnetic field (ELF) sessions, and in the fourth group (negative control), no treatment was applied. The electromagnetic field was applied through a Helmholtz coils; 30 Gauss of intensity. Results shown histological changes that improve the healing process in animals subjected to ELF together with the transfer factor.

  14. Heat pump air conditioning system for pure electric vehicle at ultra-low temperature

    Directory of Open Access Journals (Sweden)

    Li Hai-Jun

    2014-01-01

    Full Text Available When the ordinary heat pump air conditioning system of a pure electric vehicle runs at ultra-low temperature, the discharge temperature of compressor will be too high and the heating capacity of the system will decay seriously, it will lead to inactivity of the heating system. In order to solve this problem, a modification is put forward, and an experiment is also designed. The experimental results show that in the same conditions, this new heating system increases more than 20% of the heating capacity; when the outside environment temperature is negative 20 degrees, the discharge temperature of compressor is below 60 degrees.

  15. Ultra-low thermal conductivity in W/Al2O3 nanolaminates.

    Science.gov (United States)

    Costescu, R M; Cahill, D G; Fabreguette, F H; Sechrist, Z A; George, S M

    2004-02-13

    Atomic layer deposition and magnetron sputter deposition were used to synthesize thin-film multilayers of W/Al(2)O(3). With individual layers only a few nanometers thick, the high interface density produced a strong impediment to heat transfer, giving rise to a thermal conductivity of approximately 0.6 watts per meter per kelvin. This result suggests that high densities of interfaces between dissimilar materials may provide a route for the production of thermal barriers with ultra-low thermal conductivity.

  16. Planar Hall ring sensor for ultra-low magnetic moment sensing

    DEFF Research Database (Denmark)

    Hung, Tran Quang; Terki, Ferial; Kamara, Souleymanne

    2015-01-01

    The field sensitivity of a planar Hall effect (PHE) micro-ring type biosensor has been investigated as a function of magnetizing angle of the sensor material, for the sensing of low magnetic moment superparamagnetic labels. The field sensitivity is maximal at a magnetizing angle of α = 20......°. At this optimized magnetizing angle, the field sensitivity of a PHE sensor is about 3.6 times higher than that measured at the conventional configuration, α = 90°. This optimization enables the PHE-ring sensor to detect superparamagnetic biolabels with ultra-low magnetic moments down to 4 × 10-13 emu....

  17. Numerical simulation of exciton dynamics in cuprous oxide at ultra low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Som, Sunipa

    2015-06-29

    This thesis is a theoretical investigation of the relaxation behaviour of excitons in Cuprous Oxide at ultra low temperatures when the excitons are confined within a potential trap and also in a homogeneous system. Under the action of deformation potential phonon scattering only, Bose Einstein Condensation (BEC) occurs for all temperatures in the investigated range. In the case of Auger decay, we do not find at any temperature a BEC due to the heating of the exciton gas. In the case of elastic and phonon-scattering together BEC occurs in this case of 0.1 K.

  18. The Majorana experiment: an ultra-low background search for neutrinoless double-beta decay

    CERN Document Server

    Phillips, D G; Avignone, F T; Back, H O; Barabash, A S; Bergevin, M; Bertrand, F E; Boswell, M; Brudanin, V; Busch, M; Chan, Y -D; Christofferson, C D; Collar, J I; Combs, D C; Cooper, R J; Detwiler, J A; Doe, P J; Efremenko, Y; Egorov, V; Ejiri, H; Elliott, S R; Esterline, J; Fast, J E; Fields, N; Finnerty, P; Fraenkle, F M; Gehman, V M; Giovanetti, G K; Green, M P; Guiseppe, V E; Gusey, K; Hallin, A L; Hazama, R; Henning, R; Hime, A; Hoppe, E W; Horton, M; Howard, S; Howe, M A; Johnson, R A; Keeter, K J; Keller, C; Kidd, M F; Knecht, A; Kochetov, O; Konovalov, S I; Kouzes, R T; LaFerriere, B; LaRoque, B H; Leon, J; Leviner, L E; Loach, J C; MacMullin, S; Marino, M G; Martin, R D; Mei, D -M; Merriman, J; Miller, M L; Mizouni, L; Nomachi, M; Orrell, J L; Overman, N R; Poon, A W P; Perumpilly, G; Prior, G; Radford, D C; Rielage, K; Robertson, R G H; Ronquest, M C; Schubert, A G; Shima, T; Shirchenko, M; Snavely, K J; Steele, D; Strain, J; Thomas, K; Timkin, V; Tornow, W; Vanyushin, I; Varner, R L; Vetter, K; Vorren, K; Wilkerson, J F; Wolfe, B A; Yakushev, E; Young, A R; Yu, C -H; Yumatov, V; Zhang, C

    2011-01-01

    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.

  19. The MAJORANA experiment: an ultra-low background search for neutrinoless double-beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, D.; Aguayo Navarrete, Estanislao; Avignone, Frank T.; Back, Henning O.; Barabash, Alexander S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Esterline, James H.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor; Giovanetti, G. K.; Green, Matthew P.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, Reyco; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keller, C.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; LaRoque, B. H.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Wolfe, B. A.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.

    2012-12-01

    The observation of neutrinoless double-beta decay would resolve the Majorana nature of the neutrino and could provide information on the absolute scale of the neutrino mass. The initial phase of the Majorana Experiment, known as the Demonstrator, will house 40 kg of Ge in an ultra-low background shielded environment at the 4850' level of the Sanford Underground Laboratory in Lead, SD. The objective of the Demonstrator is to validate whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a narrow region of interest around the 76Ge neutrinoless double-beta decay peak.

  20. An Ultra-Low-Latency Geo-Routing Scheme for Team-Based Unmanned Vehicular Applications

    KAUST Repository

    Bader, Ahmed

    2016-02-26

    Results and lessons learned from the implementation of a novel ultra low-latency geo-routing scheme are presented in this paper. The geo-routing scheme is intended for team-based mobile systems whereby a cluster of unmanned autonomous vehicles are deployed to accomplish a critical mission under human supervision. The contention-free nature of the developed scheme lends itself to jointly achieve lower latency and higher throughput. Implementation challenges are presented and corresponding resolutions are discussed herewith. © 2015 IEEE.

  1. Detection of alpha particle contamination on ultra low activity-grade integrated circuits

    Directory of Open Access Journals (Sweden)

    Fernandes Ana C.

    2016-01-01

    Full Text Available We propose to apply the superheated droplet detector (SDD technology to the measurement of alpha-particle emissivity on integrated circuits of ultra-low activity grade (< 1α/khcm2 for high reliability applications. This work is based on the SDDs employed within our team to the direct search for dark matter. We describe the modifications in the dark matter SDDs with respect to fabrication, signal analysis and characterization, in order to obtain a device with the adequate detection sensitivity and background noise.

  2. Measurement of ultra-low ion energy of decelerated ion beam using a deflecting electric field

    Energy Technology Data Exchange (ETDEWEB)

    Thopan, P.; Suwannakachorn, D.; Tippawan, U. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2015-12-15

    In investigation on ultra-low-energy ion bombardment effect on DNA, an ion beam deceleration lens was developed for high-quality ultra-low-energy ion beam. Measurement of the ion energy after deceleration was necessary to confirm the ion beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ion beam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ion beam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ion beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ion beam line. Moving the measurement rod across the decelerated ion beam enabled to obtain beam profiles, from which the beam bending distance could be known and the ion beam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

  3. Residual Dipolar Couplings in Zero-to-Ultra-Low-Field Nuclear Magnetic Resonance

    CERN Document Server

    Blanchard, John W; King, Jonathan P; Ledbetter, Micah P; Levine, Emma H; Bajaj, Vikram S; Budker, Dmitry; Pines, Alexander

    2015-01-01

    Zero-to-ultra-low-field nuclear magnetic resonance (ZULF-NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the interaction averages to zero under isotropic molecular tumbling. Under partial orientational ordering, this information is retained in the form of so-called residual dipolar couplings. We report zero-to-ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile-2-$^{13}$C aligned in stretched polyvinyl acetate gels. This represents the first investigation of dipolar couplings as a perturbation on the indirect spin-spin $J$-coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole c...

  4. Calibration of an ultra-low-background proportional counter for measuring 37Ar

    Science.gov (United States)

    Seifert, A.; Aalseth, C. E.; Bonicalzi, R. M.; Bowyer, T. W.; Day, A. R.; Fuller, E. S.; Haas, D. A.; Hayes, J. C.; Hoppe, E. W.; Humble, P. H.; Keillor, M. E.; LaFerriere, B. D.; Mace, E. K.; McIntyre, J. I.; Merriman, J. H.; Miley, H. S.; Myers, A. W.; Orrell, J. L.; Overman, C. T.; Panisko, M. E.; Williams, R. M.

    2013-08-01

    An ultra-low-background proportional counter design has been developed at Pacific Northwest National Laboratory (PNNL) using clean materials, primarily electro-chemically-purified copper. This detector, along with an ultra-low-background counting system (ULBCS), was developed to complement a new shallow underground laboratory (30 meters water-equivalent) at PNNL. The ULBCS design includes passive neutron and gamma shielding, along with an active cosmic-veto system. This system provides a capability for making ultra-sensitive measurements to support applications like age-dating soil hydrocarbons with 14C/3H, age-dating of groundwater with 39Ar, and soil-gas assay for 37Ar to support On-Site Inspection (OSI). On-Site Inspection is a key component of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Measurements of radionuclides created by an underground nuclear explosion are valuable signatures of a Treaty violation. For OSI, the 35-day half-life of 37Ar, produced from neutron interactions with calcium in soil, provides both high specific activity and sufficient time for inspection before decay limits sensitivity. This work describes the calibration techniques and analysis methods developed to enable quantitative measurements of 37Ar samples over a broad range of proportional counter operating pressures. These efforts, along with parallel work in progress on gas chemistry separation, are expected to provide a significant new capability for 37Ar soil gas background studies.

  5. Design of nodes for embedded and ultra low-power wireless sensor networks

    Science.gov (United States)

    Xu, Jun; You, Bo; Cui, Juan; Ma, Jing; Li, Xin

    2008-10-01

    Sensor network integrates sensor technology, MEMS (Micro-Electro-Mechanical system) technology, embedded computing, wireless communication technology and distributed information management technology. It is of great value to use it where human is quite difficult to reach. Power consumption and size are the most important consideration when nodes are designed for distributed WSN (wireless sensor networks). Consequently, it is of great importance to decrease the size of a node, reduce its power consumption and extend its life in network. WSN nodes have been designed using JN5121-Z01-M01 module produced by jennic company and IEEE 802.15.4/ZigBee technology. Its new features include support for CPU sleep modes and a long-term ultra low power sleep mode for the entire node. In low power configuration the node resembles existing small low power nodes. An embedded temperature sensor node has been developed to verify and explore our architecture. The experiment results indicate that the WSN has the characteristic of high reliability, good stability and ultra low power consumption.

  6. Measurement of ultra-low ion energy of decelerated ion beam using a deflecting electric field

    Science.gov (United States)

    Thopan, P.; Suwannakachorn, D.; Tippawan, U.; Yu, L. D.

    2015-12-01

    In investigation on ultra-low-energy ion bombardment effect on DNA, an ion beam deceleration lens was developed for high-quality ultra-low-energy ion beam. Measurement of the ion energy after deceleration was necessary to confirm the ion beam really decelerated as theoretically predicted. In contrast to conventional methods, this work used a simple deflecting electrostatic field after the deceleration lens to bend the ion beam. The beam bending distance depended on the ion energy and was described and simulated. A system for the measurement of the ion beam energy was constructed. It consisted of a pair of parallel electrode plates to generate the deflecting electrical field, a copper rod measurement piece to detect ion beam current, a vernier caliper to mark the beam position, a stepping motor to translate the measurement rod, and a webcam-camera to read the beam bending distance. The entire system was installed after the ion-beam deceleration lens inside the large chamber of the bioengineering vertical ion beam line. Moving the measurement rod across the decelerated ion beam enabled to obtain beam profiles, from which the beam bending distance could be known and the ion beam energy could be calculated. The measurement results were in good agreement with theoretical and simulated results.

  7. An ultra low-voltage, low-power baseband-processor for UHF RFID tag

    Institute of Scientific and Technical Information of China (English)

    Yan HE; Jianyun HU; Hao MIN

    2008-01-01

    A novel ultra low-voltage, low-power baseband-processor for UHF radio frequency identification (RFID) tag is presented here. The baseband-processor is compa-tible with the EPCTM class-1 generation-2 (C1G2) UHF RFID protocol, and fits the requirements of ultra low-power of passive tags. Based on the analysis of the special power consumption of the tag, a new architecture is proposed. A novel scheme for generating pseudo-random numbers as well as a new method of partial-decoding is developed. Besides, other low-power techniques are also adopted for the special baseband-processor which imple-ments complex functions, such as encoding/coding, anti-collision and authorization scheme, and reading/writing operation to EEPROM. The chip was fabricated in 0.35 μm 1P3M standard CMOS process. Experimental results show that it achieves low power operation of 3.15 μW @ 1.5 V with the core area of 1.1 mm× 0.8 mm.

  8. Feasibility study of SiGHT: a novel ultra low background photosensor for low temperature operation

    Science.gov (United States)

    Wang, Y.; Fan, A.; Fiorillo, G.; Galbiati, C.; Guan, M. Y.; Korga, G.; Pantic, E.; Razeto, A.; Renshaw, A.; Rossi, B.; Suvorov, Y.; Wang, H.; Yang, C. G.

    2017-02-01

    Rare event search experiments, such as those searching for dark matter and observations of neutrinoless double beta decay, require ultra low levels of radioactive background for unmistakable identification. In order to reduce the radioactive background of detectors used in these types of event searches, low background photosensors are required, as the physical size of these detectors become increasing larger, and hence the number of such photosensors used also increases rapidly. Considering that most dark matter and neutrinoless double beta decay experiments are turning towards using noble liquids as the target choice, liquid xenon and liquid argon for instance, photosensors that can work well at cryogenic temperatures are required, 165 K and 87 K for liquid xenon and liquid argon, respectively. The Silicon Geiger Hybrid Tube (SiGHT) is a novel photosensor designed specifically for use in ultra low background experiments operating at cryogenic temperatures. It is based on the proven photocathode plus silicon photomultiplier (SiPM) hybrid technology and consists of very few other, but also ultra radio-pure, materials like fused silica and silicon for the SiPM. The introduction of the SiGHT concept, as well as a feasibility study for its production, is reported in this paper.

  9. Ultra-Low Noise Germanium Neutrino Detection system (ULGeN).

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Palmer, Belkis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Barton, Paul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-07-01

    Monitoring nuclear power plant operation by measuring the antineutrino flux has become an active research field for safeguards and non-proliferation. We describe various efforts to demonstrate the feasibility of reactor monitoring based on the detection of the Coherent Neutrino Nucleus Scattering (CNNS) process with High Purity Germanium (HPGe) technology. CNNS detection for reactor antineutrino energies requires lowering the electronic noise in low-capacitance kg-scale HPGe detectors below 100 eV as well as stringent reduction in other particle backgrounds. Existing state- of-the-art detectors are limited to an electronic noise of 95 eV-FWHM. In this work, we employed an ultra-low capacitance point-contact detector with a commercial integrated circuit preamplifier- on-a-chip in an ultra-low vibration mechanically cooled cryostat to achieve an electronic noise of 39 eV-FWHM at 43 K. We also present the results of a background measurement campaign at the Spallation Neutron Source to select the area with sufficient low background to allow a successful first-time measurement of the CNNS process.

  10. Ultra low nanowear in novel chromium/amorphous chromium carbide nanocomposite films

    Science.gov (United States)

    Yate, Luis; Martínez-de-Olcoz, Leyre; Esteve, Joan; Lousa, Arturo

    2017-10-01

    In this work, we report the first observation of novel nanocomposite thin films consisting of nanocrystalline chromium embedded in an amorphous chromium carbide matrix (nc-Cr/a-CrC) with relatively high hardness (∼22,3 GPa) and ultra low nanowear. The films were deposited onto silicon substrates using a magnetic filtered cathodic arc deposition system at various negative bias voltages, from 50 to 450 V. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) suggested the co-existence of chromium and chromium carbide phases, while high resolution transmission electron microscopy (HRTEM) confirmed the presence of the nc-Cr/a-CrC structure. The friction coefficient measured with the ball-on disk technique and the nanowear results showed a strong correlation between the macro and nano-tribological properties of the samples. These novel nanocomposite films show promising properties as solid lubricant and wear resistant coatings with relatively high hardness, low friction coefficient and ultra low nanowear.

  11. Ultra-low-dose continuous combined estradiol and norethisterone acetate: improved bleeding profile in postmenopausal women

    DEFF Research Database (Denmark)

    Sturdee, D.W.; Archer, D.F.; Rakov, V.;

    2008-01-01

    OBJECTIVE: To evaluate the effect of two ultra-low-dose hormone treatments containing estradiol (E2) 0.5 mg and norethisterone acetate (NETA) 0.1 or 0.25 mg on the endometrium and bleeding. METHODS: A prospective, randomized, placebo-controlled trial of 6 months. Local Ethics Committee approval...... at baseline and on completion. An endometrial biopsy was obtained when indicated clinically. RESULTS: In months 1-6, the amenorrhea rates with E2/NETA 0.1 were 89%, 89%, 86%, 85%, 89% and 89%, respectively and the no-bleeding rates were correspondingly high: 95%, 94%, 93%, 90%, 95% and 95%. The amenorrhea...... and spotting-only rates were similar with both ultra-low-dose combinations. The withdrawal rates due to bleeding were very low and the same in all three treatment arms (n = 1; 1%). There was a slight increase in the mean endometrial thickness in all three groups, which remained less than 5 mm. CONCLUSIONS...

  12. Note: Expanding the bandwidth of the ultra-low current amplifier using an artificial negative capacitor

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Kai, E-mail: kaixie@mail.xidian.edu.cn; Liu, Yan; Li, XiaoPing [School of Aerospace Science and Technology, Xidian University, Xi’an 710071 (China); Guo, Lixin [School of Physics and Optoelectronic Engineering, Xidian University, Xi’an 710071 (China); Zhang, Hanlu [School of Communication & Information Engineering, Xi’an University of Posts & Telecommunication, Xi’an 710121 (China)

    2016-04-15

    The bandwidth and low noise characteristics are often contradictory in ultra-low current amplifier, because an inevitable parasitic capacitance is paralleled with the high value feedback resistor. In order to expand the amplifier’s bandwidth, a novel approach was proposed by introducing an artificial negative capacitor to cancel the parasitic capacitance. The theory of the negative capacitance and the performance of the improved amplifier circuit with the negative capacitor are presented in this manuscript. The test was conducted by modifying an ultra-low current amplifier with a trans-impedance gain of 50 GΩ. The results show that the maximum bandwidth was expanded from 18.7 Hz to 3.3 kHz with more than 150 times of increase when the parasitic capacitance (∼0.17 pF) was cancelled. Meanwhile, the rise time decreased from 18.7 ms to 0.26 ms with no overshot. Any desired bandwidth or rise time within these ranges can be obtained by adjusting the ratio of cancellation of the parasitic and negative capacitance. This approach is especially suitable for the demand of rapid response to weak current, such as transient ion-beam detector, mass spectrometry analysis, and fast scanning microscope.

  13. A 10-GHz Bandwidth Electroabsorption Modulated Laser by Ultra-Low-Pressure Selective Area Growth

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qian; PAN Jiao-Qing; ZHOU Fan; WANG Bao-Jun; WANG Lu-Feng; WANG Wei

    2005-01-01

    @@ A novel integration technique has been developed using band-gap energy control of InGaAsP/InGaAsP multi quantum-well (MQW) structures during simultaneous ultra-low-pressure (22 mbar) selective-area-growth (SAG)process in metal-organic chemical vapour deposition. A fundamental study of the controllability of band gap energy by the SAG method is performed. A large band-gap photoluminescence wavelength shift of 83nm is obtained with a small mask width variation (0-30μm). The method is then applied to fabricate an MQW distributed-feedback laser monolithically integrated with an electroabsorption modulator. The experimental results exhibit superior device characteristics with low threshold of 19 mA, over 24 dB extinction ratio when coupled into a single mode fibre. More than 10 GHz modulation bandwidth is also achieved, which demonstrates that the ultra-low-pressure SAG technique is a promising approach for high-speed transmission photonic integrated circuits.

  14. A University Consortium on Low Temperature Combustion for High Efficiency, Ultra-Low Emission Engines

    Energy Technology Data Exchange (ETDEWEB)

    Assanis, Dennis N. [Univ. of Michigan, Ann Arbor, MI (United States); Atreya, Arvind [Univ. of Michigan, Ann Arbor, MI (United States); Chen, Jyh-Yuan [Univ. of California, Berkeley, CA (United States); Cheng, Wai K. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Dibble, Robert W. [Univ. of California, Berkeley, CA (United States); Edwards, Chris [Stanford Univ., CA (United States); Filipi, Zoran S. [Univ. of Michigan, Ann Arbor, MI (United States); Gerdes, Christian [Stanford Univ., CA (United States); Im, Hong [Univ. of Michigan, Ann Arbor, MI (United States); Lavoie, George A. [Univ. of Michigan, Ann Arbor, MI (United States); Wooldridge, Margaret S. [Univ. of Michigan, Ann Arbor, MI (United States)

    2009-12-31

    The objective of the University consortium was to investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines and develop methods to extend those boundaries to improve the fuel economy of these engines, while operating with ultra low emissions. This work involved studies of thermal effects, thermal transients and engine management, internal mixing and stratification, and direct injection strategies for affecting combustion stability. This work also examined spark-assisted Homogenous Charge Compression Ignition (HCCI) and exhaust after-treatment so as to extend the range and maximize the benefit of Homogenous Charge Compression Ignition (HCCI)/ Partially Premixed Compression Ignition (PPCI) operation. In summary the overall goals were; Investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines; Develop methods to extend LTC boundaries to improve the fuel economy of HCCI engines fueled on gasoline and alternative blends, while operating with ultra low emissions; and Investigate alternate fuels, ignition and after-treatment for LTC and Partially Premixed compression Ignition (PPCI) engines.

  15. A 10-GHz Bandwidth Electroabsorption Modulated Laser by Ultra-Low-Pressure Selective Area Growth

    Science.gov (United States)

    Zhao, Qian; Pan, Jiao-Qing; Zhou, Fan; Wang, Bao-Jun; Wang, Lu-Feng; Wang, Wei

    2005-08-01

    A novel integration technique has been developed using band-gap energy control of InGaAsP/InGaAsP multi-quantum-well (MQW) structures during simultaneous ultra-low-pressure (22 mbar) selective-area-growth (SAG) process in metal-organic chemical vapour deposition. A fundamental study of the controllability of band gap energy by the SAG method is performed. A large band-gap photoluminescence wavelength shift of 83 nm is obtained with a small mask width variation (0-30 μm). The method is then applied to fabricate an MQW distributed-feedback laser monolithically integrated with an electroabsorption modulator. The experimental results exhibit superior device characteristics with low threshold of 19 mA, over 24 dB extinction ratio when coupled into a single mode fibre. More than 10 GHz modulation bandwidth is also achieved, which demonstrates that the ultra-low-pressure SAG technique is a promising approach for high-speed transmission photonic integrated circuits.

  16. Continuous operation of an ultra-low-power microcontroller using glucose as the sole energy source.

    Science.gov (United States)

    Lee, Inyoung; Sode, Takashi; Loew, Noya; Tsugawa, Wakako; Lowe, Christopher Robin; Sode, Koji

    2017-07-15

    An ultimate goal for those engaged in research to develop implantable medical devices is to develop mechatronic implantable artificial organs such as artificial pancreas. Such devices would comprise at least a sensor module, an actuator module, and a controller module. For the development of optimal mechatronic implantable artificial organs, these modules should be self-powered and autonomously operated. In this study, we aimed to develop a microcontroller using the BioCapacitor principle. A direct electron transfer type glucose dehydrogenase was immobilized onto mesoporous carbon, and then deposited on the surface of a miniaturized Au electrode (7mm(2)) to prepare a miniaturized enzyme anode. The enzyme fuel cell was connected with a 100 μF capacitor and a power boost converter as a charge pump. The voltage of the enzyme fuel cell was increased in a stepwise manner by the charge pump from 330mV to 3.1V, and the generated electricity was charged into a 100μF capacitor. The charge pump circuit was connected to an ultra-low-power microcontroller. Thus prepared BioCapacitor based circuit was able to operate an ultra-low-power microcontroller continuously, by running a program for 17h that turned on an LED every 60s. Our success in operating a microcontroller using glucose as the sole energy source indicated the probability of realizing implantable self-powered autonomously operated artificial organs, such as artificial pancreas. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Beam instrumentation for the Ultra-low energy Storage Ring (USR)

    Energy Technology Data Exchange (ETDEWEB)

    Panniello, M.; Kuehnel, K. U.; Papash, A. [Max Planck Institute for Nuclear Physics (Germany); Harasimowicz, J.; Putignano, M.; Siggel-King, M. R. F.; Welsch, Carsten P., E-mail: c.p.welsch@liverpool.ac.uk [Cockcroft Institute (United Kingdom)

    2012-12-15

    The electrostatic Ultra-low energy Storage Ring (USR) at the future Facility for Low energy Antiproton and Ion Research (FLAIR) will make available antiprotons from 300 keV down to 20 keV beam energy. This multipurpose machine puts challenging demands on the beam instrumentation due to the varied bunch structure (ultra-short bunches of 1-2 ns up to a quasi-DC beam structure on the other), together with variable very low beam energies, ultra-low currents of down to 1 nA (or even less in the transfer lines which means less than 2 Multiplication-Sign 10{sup 7} particles). Thus, the development of new diagnostic devices is required as most of the standard techniques are not suitable. Within the QUASAR Group, the necessary beam instrumentation for the commissioning phase and standard operation of the USR, as well as advanced techniques such as a gas curtain-jet beam profile monitor, have been developed and prototypes of all devices have been built up. This paper presents the design of all beam diagnostics devices for the USR and summarizes the results from first measurements.

  18. Molybdenum disulfide for ultra-low detection of free radicals: electrochemical response and molecular modeling

    Science.gov (United States)

    Gupta, Ankur; Rawal, Takat B.; Neal, Craig J.; Das, Soumen; Rahman, Talat S.; Seal, Sudipta

    2017-06-01

    Two-dimensional (2D) molybdenum disulfide (MoS2) offers attractive properties due to its band gap modulation and has led to significant research-oriented applications (i.e. DNA and protein detection, cell imaging (fluorescent label) etc.). In biology, detection of free radicals (i.e. reactive oxygen species and reactive nitrogen (NO*) species are very important for early discovery and treatment of diseases. Herein, for the first time, we demonstrate the ultra-low (pico-molar) detection of pharmaceutically relevant free radicals using MoS2 for electrochemical sensing. We present pico- to nano- molar level sensitivity in smaller MoS2 with S-deficiency as revealed by x-ray photoelectron spectroscopy. Furthermore, the detection mechanism and size-dependent sensitivity have been investigated by density functional theory (DFT) showing the change in electronic density of states of Mo atoms at edges which lead to the preferred adsorption of H2O2 on Mo edges. The DFT analysis signifies the role of size and S-deficiency in the higher catalytic activity of smaller MoS2 particles and, thus, ultra-low detection.

  19. Search for 2\\beta\\ decays of 96Ru and 104Ru by ultra-low background HPGe gamma spectrometry at LNGS: final results

    CERN Document Server

    Belli, P; Cappella, F; Cerulli, R; Danevich, F A; d'Angelo, S; Incicchitti, A; Kovtun, G P; Kovtun, N G; Laubenstein, M; Poda, D V; Polischuk, O G; Shcherban, A P; Solopikhin, D A; Suhonen, J; Tretyak, V I

    2013-01-01

    An experiment to search for double beta decay processes in 96Ru and 104Ru, which are accompanied by gamma rays, has been realized in the underground Gran Sasso National Laboratories of the I.N.F.N. (Italy). Ruthenium samples with masses of about (0.5-0.7) kg were measured with the help of ultra-low background high purity Ge gamma ray spectrometry. After 2162 h of data taking the samples were deeply purified to reduce the internal contamination of 40K. The last part of the data has been accumulated over 5479 h. New improved half life limits on 2\\beta+/\\epsilon \\beta+/2\\epsilon\\ processes in 96Ru have been established on the level of 10^{20} yr, in particular for decays to the ground state of 96Mo: T1/2(2\

  20. Beneficial Effect of Ultra-Low-Dose Aspirin in Platelet Activity Alterations and Haemorrhage Observed in Experimental Portal Hypertension

    Directory of Open Access Journals (Sweden)

    F. X. Eizayaga

    2012-01-01

    Full Text Available Ultra-low-dose aspirin has shown a prothrombotic effect in the laser-induced thrombosis model. Several studies of our laboratory have shown a positive effect in rats with two different experimental models of portal hypertension: portal vein ligation, a model with an almost normal liver, and 30 days of bile duct ligation, a model with cirrhosis and presence of ascitis. In both models of portal hypertensive rats, bleeding time was prolonged and thrombi formation, in a laser-induced model of thrombi production, decreased. The hypotheses of the presented studies were that ultra-low-dose aspirin could decrease the bleeding complications in these models and that the mechanism for these effects could act thorough the COX pathway. In different studies, ultra-low dose of aspirin normalized the induced hemorrhage time, thrombi production, and platelet-endothelial cell interaction. The possible beneficial role of these doses of aspirin and mechanism of COX 2 inhibition are discussed.

  1. Robust and Energy-Efficient Ultra-Low-Voltage Circuit Design under Timing Constraints in 65/45 nm CMOS

    Directory of Open Access Journals (Sweden)

    David Bol

    2011-01-01

    Full Text Available Ultra-low-voltage operation improves energy efficiency of logic circuits by a factor of 10×, at the expense of speed, which is acceptable for applications with low-to-medium performance requirements such as RFID, biomedical devices and wireless sensors. However, in 65/45 nm CMOS, variability and short-channel effects significantly harm robustness and timing closure of ultra-low-voltage circuits by reducing noise margins and jeopardizing gate delays. The consequent guardband on the supply voltage to meet a reasonable manufacturing yield potentially ruins energy efficiency. Moreover, high leakage currents in these technologies degrade energy efficiency in case of long stand-by periods. In this paper, we review recently published techniques to design robust and energy-efficient ultra-low-voltage circuits in 65/45 nm CMOS under relaxed yet strict timing constraints.

  2. Cystic Fibrosis: Are Volumetric Ultra-Low-Dose Expiratory CT Scans Sufficient for Monitoring Related Lung Disease?

    DEFF Research Database (Denmark)

    Loeve, Martine; Lequin, Maarten H; Bruijne, Marleen de

    2009-01-01

    that differences in scores were independent of score magnitude. Conclusion: In this pilot study, CT scores from end-expiratory and end-inspiratory CT match closely, suggesting that ultra-low-dose end-expiratory CT alone may be sufficient for monitoring CF-related lung disease. This would help reduce radiation dose......Purpose: To assess whether chest computed tomography (CT) scores from ultra-low-dose end-expiratory scans alone could suffice for assessment of all cystic fibrosis (CF)-related structural lung abnormalities. Materials and Methods: In this institutional review board–approved study, 20 patients...... with CF aged 6–20 years (eight males, 12 females) underwent low-dose end-inspiratory CT and ultra-low-dose end-expiratory CT. Informed consent was obtained. Scans were randomized and scored by using the Brody-II CT scoring system to assess bronchiectasis, airway wall thickening, mucus plugging...

  3. Three Decades of Volume Change of a Small Greenlandic Glacier Using Ground Penetrating Radar, Structure from Motion, and Aerial Photogrammetry

    DEFF Research Database (Denmark)

    Marcer, M.; Stentoft, Peter Alexander; Bjerre, Elisa

    2017-01-01

    Glaciers in the Arctic are losing mass at an increasing rate. Here we use surface topography derived from Structure from Motion (SfM) and ice volume from ground penetrating radar (GPR) to describe the 2014 state of Aqqutikitsoq glacier (2.85 km) on Greenland's west coast. A photogrammetrically...... topography, the approach constitutes a viable alternative where the use of drones is not possible. Our investigations constitute the first glacier on Greenland's west coast where ice volume was determined and volume change calculated. The glacier's thinning rate is comparable to, for example, the Swiss Alps...

  4. Three Decades of Volume Change of a Small Greenlandic Glacier Using Ground Penetrating Radar, Structure from Motion, and Aerial Photogrammetry

    DEFF Research Database (Denmark)

    Marcer, M.; Stentoft, Peter Alexander; Bjerre, Elisa

    2017-01-01

    Glaciers in the Arctic are losing mass at an increasing rate. Here we use surface topography derived from Structure from Motion (SfM) and ice volume from ground penetrating radar (GPR) to describe the 2014 state of Aqqutikitsoq glacier (2.85 km) on Greenland's west coast. A photogrammetrically...... topography, the approach constitutes a viable alternative where the use of drones is not possible. Our investigations constitute the first glacier on Greenland's west coast where ice volume was determined and volume change calculated. The glacier's thinning rate is comparable to, for example, the Swiss Alps...... and underlines that arctic glaciers are subject to fast changes....

  5. Development and Commercial Application of Ultra-Low Pressure Naphtha Reforming Technology with Continuous Catalyst Regeneration

    Institute of Scientific and Technical Information of China (English)

    Ma Aizeng; Xu Youchun; Yang Dong; Zhang Xinkuan; Wang Jieguang

    2013-01-01

    The development history and major technological innovations of the ultra-low pressure naphtha reforming tech-nology with continuous catalyst regeneration in China were introduced. This technology had been adopted by the 1.0 Mt/a CCR unit at the Guangzhou Company. The appropriate catalyst was selected to meet the demand of the unit capacity, the feedstock, and the product slate. The design parameters, including the reaction pressure, the octane number of C5+ liquid product, the reaction temperature, the space velocity, the hydrogen/oil molar ratio, and the catalyst circulating rate, were chosen based on the study of process conditions and parameters. The commercial test results showed that the research oc-tane number of C5+ product reached 104 when the capacity of the CCR unit was 100% and 115% of the design value. The other technical targets attained or exceeded the expected value.

  6. Characterizing and Optimizing Photocathode Laser Distributions for Ultra-low Emittance Electron Beam Operations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, F. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bohler, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ding, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gilevich, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Loos, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ratner, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Vetter, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-12-07

    Photocathode RF gun has been widely used for generation of high-brightness electron beams for many different applications. We found that the drive laser distributions in such RF guns play important roles in minimizing the electron beam emittance. Characterizing the laser distributions with measurable parameters and optimizing beam emittance versus the laser distribution parameters in both spatial and temporal directions are highly desired for high-brightness electron beam operation. In this paper, we report systematic measurements and simulations of emittance dependence on the measurable parameters represented for spatial and temporal laser distributions at the photocathode RF gun systems of Linac Coherent Light Source. The tolerable parameter ranges for photocathode drive laser distributions in both directions are presented for ultra-low emittance beam operations.

  7. Ultra Low Voltage Class AB Switched Current Memory Cells Based on Floating Gate Transistors

    DEFF Research Database (Denmark)

    Mucha, Igor

    1999-01-01

    A proposal for a class AB switched current memory cell, suitable for ultra-low-voltage applications is presented. The proposal employs transistors with floating gates, allowing to build analog building blocks for ultralow supply voltage operation also in CMOS processes with high threshold voltages....... This paper presents the theoretical basis for the design of "floating-gate'' switched current memory cells by giving a detailed description and analysis of the most important impacts degrading the performance of the cells. To support the theoretical assumptions circuits based on "floating-gate'' switched...... current memory cells were designed using a CMOS process with threshold voltages V-T0n = \\V-T0p\\ = 0.9 V for the n- and p-channel devices. Both hand calculations and PSPICE simulations showed that the designed example switched current memory cell allowed a maximum signal range better than +/-18 mu...

  8. Theory and experiment research for ultra-low frequency maglev vibration sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Dezhi; Liu, Yixuan, E-mail: xuan61x@163.com; Guo, Zhanshe; Fan, Shangchun [School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100191 (China); Zhao, Xiaomeng [Laser Medicine Laboratory, Institute of Biomedical Engineering, Chinese Academy of medical Sciences and Peking Union Medical College, Tianjin 300192 (China)

    2015-10-15

    A new maglev sensor is proposed to measure ultra-low frequency (ULF) vibration, which uses hybrid-magnet levitation structure with electromagnets and permanent magnets as the supporting component, rather than the conventional spring structure of magnetoelectric vibration sensor. Since the lower measurement limit needs to be reduced, the equivalent bearing stiffness coefficient and the equivalent damping coefficient are adjusted by the sensitivity unit structure of the sensor and the closed-loop control system, which realizes both the closed-loop control and the solving algorithms. A simple sensor experimental platform is then assembled based on a digital hardware system, and experimental results demonstrate that the lower measurement limit of the sensor is increased to 0.2 Hz under these experimental conditions, indicating promising results of the maglev sensor for ULF vibration measurements.

  9. The influence of molybdenum on stress corrosion in Ultra Low Carbon Steels with copper addition

    Directory of Open Access Journals (Sweden)

    M. Mazur

    2010-07-01

    Full Text Available The influence of molybdenum content on the process of stress corrosion of ultra-low carbon structural steels with the addition of copper HSLA (High Strength Low Alloy was analyzed. The study was conducted for steels after heat treatment consisting of quenching andfollowing tempering at 600°C and it was obtained microstructure of the tempered martensite laths with copper precipitates and the phaseLaves Fe2Mo type. It was found strong influence of Laves phase precipitate on the grain boundaries of retained austenite on rate anddevelopment of stress corrosion processes. The lowest corrosion resistance was obtained for W3 steel characterized by high contents ofmolybdenum (2.94% Mo which should be connected with the intensity precipitate processes of Fe2Mo phase. For steels W1 and W2which contents molybdenum equals 1.02% and 1.88%, respectively were obtained similar courses of corrosive cracking.

  10. The development of SiGHT: an ultra low background photosensor

    Science.gov (United States)

    Wang, Y.; Fan, A.; Fiorillo, G.; Galbiati, C.; Guan, M. Y.; Korga, G.; Pantic, E.; Razeto, A.; Renshaw, A.; Rossi, B.; Suvorov, Y.; Wang, H.; Yang, C. G.

    2016-09-01

    The Silicon Geiger Hybrid Tube (SiGHT) is a novel photosensor designed for future generations of rare event search experiments using noble liquids. The main idea is to replace conventional multi-dynode photomultiplier tubes (PMTs) with a hybrid technology, consisting of a low temperature sensitive bialkali photocathode for conversion of photons into photoelectrons and a low dark count silicon photomultiplier (SiPM) for photoelectron signal amplification. SiGHT can achieve ultra low internal radioactivity, high quantum efficiency and stable performance at low temperatures, which are required features for rare event searches such as direct dark matter detection and neutrinoless double beta decay experiments. The first SiGHT prototype fabrication is in progress at UCLA. The current status of the development is presented.

  11. Ultra-low-frequency wave-driven diffusion of radiation belt relativistic electrons.

    Science.gov (United States)

    Su, Zhenpeng; Zhu, Hui; Xiao, Fuliang; Zong, Q-G; Zhou, X-Z; Zheng, Huinan; Wang, Yuming; Wang, Shui; Hao, Y-X; Gao, Zhonglei; He, Zhaoguo; Baker, D N; Spence, H E; Reeves, G D; Blake, J B; Wygant, J R

    2015-12-22

    Van Allen radiation belts are typically two zones of energetic particles encircling the Earth separated by the slot region. How the outer radiation belt electrons are accelerated to relativistic energies remains an unanswered question. Recent studies have presented compelling evidence for the local acceleration by very-low-frequency (VLF) chorus waves. However, there has been a competing theory to the local acceleration, radial diffusion by ultra-low-frequency (ULF) waves, whose importance has not yet been determined definitively. Here we report a unique radiation belt event with intense ULF waves but no detectable VLF chorus waves. Our results demonstrate that the ULF waves moved the inner edge of the outer radiation belt earthward 0.3 Earth radii and enhanced the relativistic electron fluxes by up to one order of magnitude near the slot region within about 10 h, providing strong evidence for the radial diffusion of radiation belt relativistic electrons.

  12. Ultra Low-Power Acoustic Detector Applicable in Ambient Assistance Living Systems

    Directory of Open Access Journals (Sweden)

    Iliev I.

    2009-12-01

    Full Text Available Ambient Assisted Living (AAL includes methods, concepts, systems, devices as well as services, which provide unobtrusive support for daily life based on the context and situation of the assisted person. The technologies applied for AAL are user-centric, i.e. oriented towards the needs and capabilities of the particular user. They are also integrated into the immediate personal environment of the user. As a consequence, the technology is adapting to the user rather than the other way around. The in-house monitoring of elderly or disabled people (hard of hearing, deaf, with limited movement ability, using intelligent sensors is a very desirable service that may potentially increase the user's autonomy and independence while minimizing the risks of living alone. The described ultra low-power acoustic detector allows upgrade of the presented warning systems. It features long-term autonomy and possibility to use it as an element of the wireless personal area network (WPAN.

  13. Development of Ultra-Low Power Metal Oxide Sensors and Arrays for Embedded Applications

    Science.gov (United States)

    Lutz, Brent; Wind, Rikard; Kostelecky, Clayton; Routkevitch, Dmitri; Deininger, Debra

    2011-09-01

    Metal oxide semiconductor sensors are widely used as individual sensors and in arrays, and a variety of designs for low power microhotplates have been demonstrated.1 Synkera Technologies has developed an embeddable chemical microsensor platform, based on a unique ceramic MEMS technology, for practical implementation in cell phones and other mobile electronic devices. Key features of this microsensor platform are (1) small size, (2) ultra-low power consumption, (3) high chemical sensitivity, (4) accurate response to a wide-range of threats, and (5) low cost. The sensor platform is enabled by a combination of advances in ceramic micromachining, and precision deposition of sensing films inside the high aspect ratio pores of anodic aluminum oxide (AAO).

  14. Using MOF-74 for Hg2+ removal from ultra-low concentration aqueous solution

    Science.gov (United States)

    Xiong, Yang Yang; Li, Jian Qiang; Gong, Le Le; Feng, Xue Feng; Meng, Li Na; Zhang, Le; Meng, Pan Pan; Luo, Ming Biao; Luo, Feng

    2017-02-01

    Mercury (Hg2+) ions have very high toxicity and widely spread as environmental pollutants. At present, many efforts have been taken to remove the hazardous materials of mercury(II) by adsorption, and it is highly desirable to develop a novel adsorbent with high adsorptive capacities. However it is still a big challenge to remove the ultra-low-concentration mercury ions from water. In this paper, MOF-74-Zn is explored for such function, showing high removal rate of Hg(II) from water without any pretreatment, especially for the ultra-trace Hg(II) ions in the ppb magnitude with the removal rate reaching to 54.48%, 69.71%, 72.26% when the initial concentration of Hg(II) is 20ppb, 40ppb, 50ppb, respectively.

  15. GRABGAM: A Gamma Analysis Code for Ultra-Low-Level HPGe SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.

    1999-07-28

    The GRABGAM code has been developed for analysis of ultra-low-level HPGe gamma spectra. The code employs three different size filters for the peak search, where the largest filter provides best sensitivity for identifying low-level peaks and the smallest filter has the best resolution for distinguishing peaks within a multiplet. GRABGAM basically generates an integral probability F-function for each singlet or multiplet peak analysis, bypassing the usual peak fitting analysis for a differential f-function probability model. Because F is defined by the peak data, statistical limitations for peak fitting are avoided; however, the F-function does provide generic values for peak centroid, full width at half maximum, and tail that are consistent with a Gaussian formalism. GRABGAM has successfully analyzed over 10,000 customer samples, and it interfaces with a variety of supplementary codes for deriving detector efficiencies, backgrounds, and quality checks.

  16. Ultra low energy results and their impact to dark matter and low energy neutrino physics

    CERN Document Server

    Bougamont, E; Derre, J; Giomataris, I; Gerbier, G; Gros, M; Magnier, P; Navick, X F; Salin, P; Savvidis, I; Tsiledakis, G; Vergados, J D

    2010-01-01

    We present ultra low energy results taken with the novel Spherical Proportional Counter. The energy threshold has been pushed down to about 25 eV and single electrons are clearly collected and detected. To reach such performance low energy calibration systems have been successfully developed: - A pulsed UV lamp extracting photoelectrons from the inner surface of the detector - Various radioactive sources allowing low energy peaks through fluorescence processes. The bench mark result is the observation of a well resolved peak at 270 eV due to carbon fluorescence which is unique performance for such large-massive detector. It opens a new window in dark matter and low energy neutrino search and may allow detection of neutrinos from a nuclear reactor or from supernova via neutrino-nucleus elastic scattering

  17. Prospects of cold dark matter searches with an ultra-low-energy germanium detector

    CERN Document Server

    Wong, H T

    2007-01-01

    The report describes the research program on the development of ultra-low-energy germanium detectors, with emphasis on WIMP dark matter searches. A threshold of 100 eV is achieved with a 20 g detector array, providing a unique probe to the low-mas WIMP. Present data at a surface laboratory is expected to give rise to comparable sensitivities with the existing limits at the $\\rm{5 - 10 GeV}$ WIMP-mass range. The projected parameter space to be probed with a full-scale, kilogram mass-range experiment is presented. Such a detector would also allow the studies of neutrino-nucleus coherent scattering and neutrino magnetic moments.

  18. Design of Ultra Low Power 8-Channel Analog Multiplexer Using Dynamic Threshold for Biosignals

    Directory of Open Access Journals (Sweden)

    D.Hari Priya

    2013-10-01

    Full Text Available The design of an ultra low voltage, low power high speed 8 channel Analog multiplexer in 180nm CMOS technology is presented. A modified transmission gate using a dynamic threshold voltage MOSFET (DTMOS is employed in the design. The design is optimized with respect to critical requirements like short switching time, low power dissipation, good linearity and high dynamic range with an operating voltage of 0.4V. The ON and OFF resistances achieved are 32 ohms and 10Mohms respectively with a switching speed of 10MHz. The power dissipation obtained is around 2.65uW for a dynamic range of 1uV to 0.4V.

  19. Ultra Low Level Tritium Analysis Method Using a Liquid Scintillation Counter

    Energy Technology Data Exchange (ETDEWEB)

    Noh, S. J.; Kim, H. J.; Kim, H.; Lim, H. J.; Lee, M. W.; Jeong, D. H.; Kim, J. K.; Kang, Y. R. [Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Nam, S. H. [Inje University, Gimhae, (Korea, Republic of)

    2015-05-15

    To evaluate {sup 3}H concentration in the atmosphere more accurately compared to the conventional methods, the author of this paper intended to suggest more improved analytical methods and derived the elements which might occur during analysis or required improvements. The method suggested in this study is able to reduce the uncertainty and errors which may be existent in evaluating the {sup 3}H concentration of environmental sample s and thus will serve as the best solution in the technical and economic point of view. Liquid Scintillation Counter is the most widely used to analyze ultra-low level {sup 3}H by using CPM / DPM Counting Mode using external radiation source and Spectrum Plot Mode using internal radiation source. In CPM / DPM Counting Mode, multiple samples can be measured by single calibration despite its rather higher background whereas Spectrum Plot Mode requires more time and cost to analyze multiple samples despite its reliability to reduce the contribution of other radionuclides.

  20. A Survey of Novel Processes to Produce Ultra Low Sulfur Gasoline

    Institute of Scientific and Technical Information of China (English)

    Xu Yun; Long Jun; Shao Xinjun

    2003-01-01

    The restriction on sulfur level in gasoline has been increasingly tightened. The U.S.Tier Ⅱ regulation requires a reduction from average 340ppm to 30ppm from 2004 to 2008. Recently significant progress has been made in effective high sulfur removal, such as post treatment of FCC gasoline by selective hydrotreating, S Zorb sulfur removal technology, OATS process etc. The sulfur content of FCC gasoline can be deceased to less than 10ppm. With regard to gasoline pool composition in China, it is very important to look for effective desulfurization processes that are simple, straightforward, with less hydrogen consumption. Post-treatment of FCC gasoline is a preferred option. From the point of view of comprehensive utilization, alkylation, polymerization, isomerisation etc. can be added to desulfurization process to meet the requirement of ultra low sulfur, premium.

  1. Multi-Channel SQUID System for MEG and Ultra-Low-Field MRI

    CERN Document Server

    Zotev, V S; Volegov, P L; Sandin, H J; Espy, M A; Mosher, J C; Urbaitis, A V; Newman, S G; Zotev, Vadim S.; Matlachov, Andrei N.; Volegov, Petr L.; Sandin, Henrik J.; Espy, Michelle A.; Mosher, John C.; Urbaitis, Algis V.; Newman, Shaun G.; Jr, Robert H. Kraus

    2007-01-01

    A seven-channel system capable of performing both magnetoencephalography (MEG) and ultra-low-field magnetic resonance imaging (ULF MRI) is described. The system consists of seven second-order SQUID gradiometers with 37 mm diameter and 60 mm baseline, having magnetic field resolution of 1.2-2.8 fT/rtHz. It also includes four sets of coils for 2-D Fourier imaging with pre-polarization. The system's MEG performance was demonstrated by measurements of auditory evoked response. The system was also used to obtain a multi-channel 2-D image of a whole human hand at the measurement field of 46 microtesla with 3 by 3 mm resolution.

  2. Ultra-low-power wireless transmitter for neural prostheses with modified pulse position modulation.

    Science.gov (United States)

    Goodarzy, Farhad; Skafidas, Stan E

    2014-01-01

    An ultra-low-power wireless transmitter for embedded bionic systems is proposed, which achieves 40 pJ/b energy efficiency and delivers 500 kb/s data using the medical implant communication service frequency band (402-405 MHz). It consumes a measured peak power of 200 µW from a 1.2 V supply while occupying an active area of 0.0016 mm(2) in a 130 nm technology. A modified pulse position modulation technique called saturated amplified signal is proposed and implemented, which can reduce the overall and per bit transferred power consumption of the transmitter while reducing the complexity of the transmitter architectures, and hence potentially shrinking the size of the implemented circuitry. The design is capable of being fully integrated on single-chip solutions for surgically implanted bionic systems, wearable devices and neural embedded systems.

  3. Development of a dedicated ethanol ultra-low emission vehicle (ULEV) -- Phase 2 report

    Energy Technology Data Exchange (ETDEWEB)

    Dodge, L.G.; Bourn, G.; Callahan, T.J.; Naegeli, D.W.; Shouse, K.R.; Smith, L.R.; Whitney, K.A. [Southwest Research Inst., San Antonio, TX (United States)

    1995-09-01

    The objective of this 3.5-year project is to develop a commercially competitive vehicle powered by ethanol (or an ethanol blend) that can meet California`s ultra-low emission vehicle (ULEV) standards and equivalent corporate average fuel economy (CAFE) energy efficiency for a light-duty passenger car application. The definition of commercially competitive is independent of fuel cost, but does include technical requirements for competitive power, performance, refueling times, vehicle range, driveability, fuel handling safety, and overall emissions performance. This report summarizes the second phase of this project, which lasted 12 months. This report documents two baseline vehicles, the engine modifications made to the original equipment manufacturer (OEM) engines, advanced aftertreatment testing, and various fuel tests to evaluate the flammability, lubricity, and material compatibility of the ethanol fuel blends.

  4. Effect of ultra-low dose whole-body-irradiation on patients with severe myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Arimori, Shigeru; Koriyama, Kenji (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)

    1982-12-01

    An ultra-low dose whole body irradiation therapy was given to 5 patients with intractable bulbar syndrome, in a dose of 10 rad/fraction, 2 times a week for 5 weeks, with a total of 100 rad; and effects of this therapy on their clinical symptoms and immunological ability were discussed. In 3 of them, bulbar syndrome was improved, and the other one, the first irradiation was effective. The peripheral leukocyte count and lymphocyte count became lowest immediately after completion of the irradiation, and returned to the normal level within 1 to 2 months. The function of T-cells, especially suppressive T-cells, was recovered; and decrease in B-cells, resulted in a decrease in the AChR antibody titer.

  5. An Ultra-Low-Power Oscillator with Temperature and Process Compensation for UHF RFID Transponder

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2013-06-01

    Full Text Available This paper presents a 1.28MHz ultra-low-power oscillator with temperature and process compensation. It is very suitable for clock generation circuits used in ultra-high-frequency (UHF radio-frequency identification (RFID transponders. Detailed analysis of the oscillator design, including process and temperature compensation techniques are discussed. The circuit is designed using TSMC 0.18μm standard CMOS process and simulated with Spectre. Simulation results show that, without post-fabrication calibration or off-chip components, less than ±3% frequency variation is obtained from –40 to 85°C in three different process corners. Monte Carlo simulations have also been performed, and demonstrate a 3σ deviation of about 6%. The power for the proposed circuitry is only 1.18µW at 27°C.

  6. Ultra-Low-Voltage Self-Body Biasing Scheme and Its Application to Basic Arithmetic Circuits

    Directory of Open Access Journals (Sweden)

    Ramiro Taco

    2015-01-01

    Full Text Available The gate level body biasing (GLBB is assessed in the context of ultra-low-voltage logic designs. To this purpose, a GLBB mirror full adder is implemented by using a commercial 45 nm bulk CMOS triple-well technology and compared to equivalent conventional zero body-biased CMOS and dynamic threshold voltage MOSFET (DTMOS circuits under different running conditions. Postlayout simulations demonstrate that, at the parity of leakage power consumption, the GLBB technique exhibits a significant concurrent reduction of the energy per operation and the delay in comparison to the conventional CMOS and DTMOS approaches. The silicon area required by the GLBB full adder is halved with respect to the equivalent DTMOS implementation, but it is higher in comparison to conventional CMOS design. Performed analysis also proves that the GLBB solution exhibits a high level of robustness against temperature fluctuations and process variations.

  7. Design of an ultra-low-power digital processor for passive UHF RFID tags

    Institute of Scientific and Technical Information of China (English)

    Shi Wanggen; Zhuang Yiqi; Li Xiaoming; Wang Xianghua; Jin Zhao; Wang Dan

    2009-01-01

    A new architecture of digital processors for passive UHF radio-frequency identification tags is proposed.This architecture is based on ISO/IEC 18000-6C and targeted at ultra-low power consumption.By applying methods like system-level power management,global clock gating and low voltage implementation,the total power of the design is reduced to a few microwatts.In addition,an innovative way for the design of a true RNG is presented,which contributes to both low power and secure data transaction.The digital processor is verified by an integrated FPGA platform and implemented by the Synopsys design kit for ASIC flows.The design fits different CMOS technologies and has been taped out using the 2P4M 0.35μm process of Chartered Semiconductor.

  8. TEMPERATURE ANISOTROPY IN THE PRESENCE OF ULTRA LOW FREQUENCY WAVES IN THE TERRESTRIAL FORESHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Selzer, L. A.; Hnat, B.; Osman, K. T.; Nakariakov, V. M. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom); Eastwood, J. P. [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College London, London (United Kingdom); Burgess, D., E-mail: L.A.Selzer@warwick.ac.uk [School of Physics and Astronomy, Queen Mary University of London (United Kingdom)

    2014-06-10

    We report the first study of the correlation between elevated solar wind core plasma temperatures and temperature anisotropy in the terrestrial foreshock. Plasma temperature is enhanced near the fire hose marginal stability threshold in the presence of ultra low frequency (ULF) large amplitude magnetic perturbations, which are intrinsically right-hand circularly polarized. Direct comparison of contemporaneous anisotropic temperatures in the upstream solar wind and the foreshock suggests that the net heating of plasma is mediated via increase of the parallel temperature in the foreshock region where the ULF waves are present. We consider the possibility that a mechanism based on Landau damping, where solar wind plasma temperature parallel to the background magnetic field is increased by interaction with oblique compressible fast magneto-acoustic ULF waves, influences temperature anisotropy.

  9. Direct imaging of neural currents using ultra-low field magnetic resonance techniques

    Science.gov (United States)

    Volegov, Petr L.; Matlashov, Andrei N.; Mosher, John C.; Espy, Michelle A.; Kraus, Jr., Robert H.

    2009-08-11

    Using resonant interactions to directly and tomographically image neural activity in the human brain using magnetic resonance imaging (MRI) techniques at ultra-low field (ULF), the present inventors have established an approach that is sensitive to magnetic field distributions local to the spin population in cortex at the Larmor frequency of the measurement field. Because the Larmor frequency can be readily manipulated (through varying B.sub.m), one can also envision using ULF-DNI to image the frequency distribution of the local fields in cortex. Such information, taken together with simultaneous acquisition of MEG and ULF-NMR signals, enables non-invasive exploration of the correlation between local fields induced by neural activity in cortex and more `distant` measures of brain activity such as MEG and EEG.

  10. Coupled flow and anisotropy in the UltraLow Velocity Zones

    Science.gov (United States)

    Hier-Majumder, Saswata; Drombosky, Tyler W.

    2016-09-01

    Seismic observations reveal a patchwork of thin and dense structures, named UltraLow Velocity Zones (ULVZs) atop the Earth's core mantle boundary. The high width to height ratio of the ULVZs, their spatial correlation with the edges of Large Low Shear Velocity Provinces (LLSVPs), and their preservation as distinct structures in the convecting mantle remain an enigmatic problem. In this article, we carry out a series of numerical simulations using Fast Multipole Boundary Elements Method (FMBEM) to address these questions and study the internal deformation within the ULVZs. Our results demonstrate that coupled flow between dense, low viscosity ULVZ patches and the LLSVP accumulates the ULVZ into stable piles along LLSVP corners, while coalescence and gravitational drainage leads to thin and wide ULVZs away from the corners. Deformation of the matrix is localized within the weaker ULVZ and the LLSVP edges, while the strain in the interior of the LLSVP remains uniform and low, explaining the observed localized anisotropy near LLSVP edges.

  11. Ultra-low noise TES bolometer arrays for SAFARI instrument on SPICA

    Science.gov (United States)

    Khosropanah, P.; Suzuki, T.; Ridder, M. L.; Hijmering, R. A.; Akamatsu, H.; Gottardi, L.; van der Kuur, J.; Gao, J. R.; Jackson, B. D.

    2016-07-01

    SRON is developing ultra-low noise Transition Edge Sensors (TESs) based on a superconducting Ti/Au bilayer on a suspended SiN island with SiN legs for the SAFARI instrument aboard the SPICA mission. We successfully fabricated TESs with very narrow (0.5-0.7 μm) and thin (0.25 μm) SiN legs on different sizes of SiN islands using deep reactiveion etching process. The pixel size is 840x840 μm2 and there are variety of designs with and without optical absorbers. For TESs without absorbers, we measured electrical NEPs as low as TESs with absorbers, we quantified the darkness of our setup and confirmed a photon noise level of 2x10-19 W/√Hz.

  12. Development of a dedicated ethanol ultra-low-emissions vehicle (ULEV): Phase 3 report

    Energy Technology Data Exchange (ETDEWEB)

    Dodge, L; Callahan, T; Leone, D; Naegeli, D; Shouse, K; Smith, L; Whitney, K [Southwest Research Inst., San Antonio, TX (United States)

    1998-04-01

    The objective of the 3.5 year project discussed in this report was to develop a commercially competitive vehicle powered by ethanol (or an ethanol blend) that can meet California`s Ultra Low Emissions Vehicle (ULEV) standards and equivalent Corporate Average Fuel Economy (CAFE) energy efficiency for a light duty passenger car application. This particular report summarizes the third phase of the project, which lasted 12 months. Emissions tests were conducted with advanced after-treatment devices on one of the two, almost identical, test vehicles, a 1993 Ford Taurus flexible fuel vehicle. The report also covers tests on the engine removed from the second Taurus vehicle. This engine was modified for an increased compression ratio, fitted with air assist injectors, and included an advanced engine control system with model-based control.

  13. Simultaneous measurement of tritium and radiocarbon by ultra-low-background proportional counting

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Emily; Aalseth, Craig; Alexander, Tom; Back, Henning; Day, Anthony; Hoppe, Eric; Keillor, Martin; Moran, Jim; Overman, Cory; Panisko, Mark; Seifert, Allen

    2017-08-01

    Use of ultra-low-background capabilities at Pacific Northwest National Laboratory provide enhanced sensitivity for measurement of low-activity sources of tritium and radiocarbon using proportional counters. Tritium levels are nearly back to pre-nuclear test backgrounds (~2-8 TU in rainwater), which can complicate their dual measurement with radiocarbon due to overlap in the isotope’s respective energy spectra. This activity makes direct dual-isotope measurements challenging without additional chemistry to concentrate the tritium in a sample. We present results of single-isotope proportional counter measurements used to analyze a dual-isotope methane sample synthesized from ~120 mg of H2O and present sensitivity results.

  14. Performance of plasma sputtered fuel cell electrodes with ultra-low Pt loadings

    Energy Technology Data Exchange (ETDEWEB)

    Cavarroc, M.; Ennadjaoui, A. [MID Dreux Innovation, CAdD, 4 Rue Albert Caquot-28500 Vernouillet (France); Mougenot, M.; Brault, P.; Escalier, R.; Tessier, Y. [Groupe de Recherches sur l' Energetique des Milieux Ionises, CNRS Universite d' Orleans, BP6744, 14 rue d' Issoudun, 45067 Orleans (France); Durand, J.; Roualdes, S. [Institut Europeen des Membranes, ENSCM, UM2, CNRS, Universite Montpellier 2, CC047, Place Eugene Bataillon, 34095 Montpellier cedex 5 (France); Sauvage, T. [Conditions Extremes et Materiaux, Haute Temperature et Irradiation, UPR3079 CNRS, Site Cyclotron, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France); Coutanceau, C. [Laboratoire de Catalyse en Chimie Organique, UMR6503 Universite de Poitiers, CNRS, 86022, Poitiers (France)

    2009-04-15

    Ultra-low Pt content PEMFC electrodes have been manufactured using magnetron co-sputtering of carbon and platinum on a commercial E-Tek {sup registered} uncatalyzed gas diffusion layer in plasma fuel cell deposition devices. Pt loadings of 0.16 and 0.01 mg cm{sup -2} have been realized. The Pt catalyst is dispersed as small clusters with size less than 2 nm over a depth of 500 nm. PEMFC test with symmetric electrodes loaded with 10 {mu}g cm{sup -2} led to maximum reproducible power densities as high as 0.4 and 0.17 W cm{sup -2} with Nafion {sup registered} 212 and Nafion {sup registered} 115 membranes, respectively. (author)

  15. Formation mechanism of spheroidal carbide in ultra-low carbon ductile cast iron

    Directory of Open Access Journals (Sweden)

    Bin-guo Fu

    2016-09-01

    Full Text Available The formation mechanism of the spheroidal carbide in the ultra-low carbon ductile cast iron fabricated by the metal mold casting technique was systematically investigated. The results demonstrated that the spheroidal carbide belonged to eutectic carbide and crystallized in the isolated eutectic liquid phase area. The formation process of the spheroidal carbide was related to the contact and the intersection between the primary dendrite and the secondary dendrite of austenite. The oxides of magnesium, rare earths and other elements can act as heterogeneous nucleation sites for the spheroidal carbide. It was also found that the amount of the spheroidal carbide would increase with an increase in carbon content. The cooling rate has an important influence on the spheroidal carbide under the same chemical composition condition.

  16. Ultra Low Density Shape Memory Polymer Foams With Tunable Physicochemical Properties for Treatment of intracranial Aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, Pooja [Texas A & M Univ., College Station, TX (United States)

    2013-12-01

    Shape memory polymers (SMPs) are a rapidly emerging class of smart materials that can be stored in a deformed temporary shape, and can actively return to their original shape upon application of an external stimulus such as heat, pH or light. This behavior is particularly advantageous for minimally invasive biomedical applications comprising embolic/regenerative scaffolds, as it enables a transcatheter delivery of the device to the target site. The focus of this work was to exploit this shape memory behavior of polyurethanes, and develop an efficient embolic SMP foam device for the treatment of intracranial aneurysms.In summary, this work reports a novel family of ultra low density polymer foams which can be delivered via a minimally invasive surgery to the aneurysm site, actuated in a controlled manner to efficiently embolize the aneurysm while promoting physiological fluid/blood flow through the reticulated/open porous structure, and eventually biodegrade leading to complete healing of the vasculature.

  17. Ultra low-energy switch based on a cavity soliton laser with pump modulation

    Science.gov (United States)

    Eslami, M.; Gandomani, S. Z.; Prati, F.; Tajalli, H.; Kheradmand, R.

    2017-01-01

    We study the effects of pump modulation in a cavity soliton laser consisting of a vertical cavity surface emitting laser with an intra-cavity saturable absorber. We show that a drifting soliton experiences enhanced mobility features by modulating the pump at the resonance frequency, and the effects are even larger below resonance. In particular, pump modulation reduces the rest time of the soliton in the initial stage of the motion and it increases its drift velocity in this regime. Moreover, pump modulation allows a decrease in the switching energy of the soliton to an amount equal to 36 photons. These results indicate that pump modulation is a promising way for the use of a cavity soliton laser as a fast optical buffer and an ultra low-energy optical switch.

  18. Theory and experiment research for ultra-low frequency maglev vibration sensor.

    Science.gov (United States)

    Zheng, Dezhi; Liu, Yixuan; Guo, Zhanshe; Zhao, Xiaomeng; Fan, Shangchun

    2015-10-01

    A new maglev sensor is proposed to measure ultra-low frequency (ULF) vibration, which uses hybrid-magnet levitation structure with electromagnets and permanent magnets as the supporting component, rather than the conventional spring structure of magnetoelectric vibration sensor. Since the lower measurement limit needs to be reduced, the equivalent bearing stiffness coefficient and the equivalent damping coefficient are adjusted by the sensitivity unit structure of the sensor and the closed-loop control system, which realizes both the closed-loop control and the solving algorithms. A simple sensor experimental platform is then assembled based on a digital hardware system, and experimental results demonstrate that the lower measurement limit of the sensor is increased to 0.2 Hz under these experimental conditions, indicating promising results of the maglev sensor for ULF vibration measurements.

  19. An ultra-low noise, high-voltage piezo-driver.

    Science.gov (United States)

    Pisenti, N C; Restelli, A; Reschovsky, B J; Barker, D S; Campbell, G K

    2016-12-01

    We present an ultra-low noise, high-voltage driver suited for use with piezoelectric actuators and other low-current applications. The architecture uses a flyback switching regulator to generate up to 250 V in our current design, with an output of 1 kV or more possible with small modifications. A high slew-rate op-amp suppresses the residual switching noise, yielding a total root-mean-square noise of ≈100 μV (1 Hz-100 kHz). A low-voltage (±10 V), high bandwidth signal can be summed with unity gain directly onto the output, making the driver well-suited for closed-loop feedback applications. Digital control enables both repeatable setpoints and sophisticated control logic, and the circuit consumes less than 150 mA at ±15 V.

  20. An ultra-low noise, high-voltage piezo-driver

    Science.gov (United States)

    Pisenti, N. C.; Restelli, A.; Reschovsky, B. J.; Barker, D. S.; Campbell, G. K.

    2016-12-01

    We present an ultra-low noise, high-voltage driver suited for use with piezoelectric actuators and other low-current applications. The architecture uses a flyback switching regulator to generate up to 250 V in our current design, with an output of 1 kV or more possible with small modifications. A high slew-rate op-amp suppresses the residual switching noise, yielding a total root-mean-square noise of ≈100 μV (1 Hz-100 kHz). A low-voltage (±10 V), high bandwidth signal can be summed with unity gain directly onto the output, making the driver well-suited for closed-loop feedback applications. Digital control enables both repeatable setpoints and sophisticated control logic, and the circuit consumes less than 150 mA at ±15 V.

  1. Zero and Ultra-Low-Field Nuclear Magnetic Resonance Spectroscopy Via Optical Magnetometry

    Science.gov (United States)

    Blanchard, John Woodland

    Nuclear magnetic resonance (NMR) is among the most powerful analytical tools available to the chemical and biological sciences for chemical detection, characterization, and structure elucidation. NMR experiments are usually performed in large magnetic fields in order to maximize sensitivity and increase chemical shift resolution. However, the high magnetic fields required for conventional NMR necessitate large, immobile, and expensive superconducting magnets, limiting the use of the technique. New hyperpolarization and non-inductive detection methods have recently allowed for NMR measurements in the inverse regime of extremely low magnetic fields. Whereas a substantial body of research has been conducted in the high-field regime, taking advantage of the efficient coherent control afforded by a spectroscopy dominated by coupling to the spectrometer, the zero- and ultra-low-field (ZULF) regime has remained mostly unexplored. In this dissertation, we investigate the applicability of ZULF-NMR as a novel spectroscopic technique complimentary to high-field NMR. In particular, we consider various aspects of the ZULF-NMR experiment and the dynamics of nuclear spins under various local spin coupling Hamiltonians. We first survey zero-field NMR experiments on systems dominated by the electron-mediated indirect spin-spin coupling (J-coupling). The resulting J-spectra permit precision measurement of chemically relevant information due to the exquisite sensitivity of J-couplings to subtle changes in molecular geometry and electronic structure. We also consider the effects of weak magnetic fields and residual dipolar couplings in anisotropic media, which encode information about nuclear magnetic moments and geometry, and further resolve topological ambiguities by lifting degeneracies. By extending the understanding of the interactions that contribute to ZULF-NMR spectra, this work represents a significant advancement towards a complete description of zero- and ultra-low

  2. Ultra-low-dose estriol and lactobacilli in the local treatment of postmenopausal vaginal atrophy.

    Science.gov (United States)

    Jaisamrarn, U; Triratanachat, S; Chaikittisilpa, S; Grob, P; Prasauskas, V; Taechakraichana, N

    2013-06-01

    The aim of this study was to demonstrate the efficacy of an ultra-low-dose vaginal estriol 0.03 mg in combination with viable Lactobacillus acidophilus KS400 (Gynoflor(®) vaginal tablets) in the short-term therapy and to investigate the long-term maintenance dose in the treatment of vaginal atrophy. This was a double-blind, randomized, placebo-controlled study (Controlled phase--initial therapy) followed by an open-label follow-up (Open phase--test medication initial and maintenance therapy). Included were postmenopausal women with vaginal atrophy symptoms and Vaginal Maturation Index (VMI) of ≤ 40%. The method of treatment was initial therapy with test medication (or placebo in first phase), one vaginal tablet daily for 12 days, followed by maintenance therapy, one tablet on two consecutive days weekly for 12 weeks. A total of 87 women completed the study. The Controlled phase results for a change in VMI demonstrated superiority of the 0.03 mg estriol-lactobacilli combination to placebo (p VMI was 35.2%, compared to 9.9% in the placebo group. In the Open phase after the initial therapy, the VMI was increased to 55.4% and, during maintenance therapy, it stayed at a comparable level (52.8-49.4%). The maturation of epithelium was followed by improvement of clinical symptoms and normalization of the vaginal ecosystem. The ultra-low-dose, vaginal 0.03 mg estriol-lactobacilli combination (Gynoflor(®)) was superior to placebo with respect to changes in VMI after the 12-day initial therapy, and the maintenance therapy of two tablets weekly was sufficient to prevent the relapse of vaginal atrophy.

  3. An ultra-low-power RF transceiver for WBANs in medical applications

    Science.gov (United States)

    Qi, Zhang; Xiaofei, Kuang; Nanjian, Wu

    2011-06-01

    A 2.4 GHz ultra-low-power RF transceiver with a 900 MHz auxiliary wake-up link for wireless body area networks (WBANs) in medical applications is presented. The RF transceiver with an asymmetric architecture is proposed to achieve high energy efficiency according to the asymmetric communication in WBANs. The transceiver consists of a main receiver (RX) with an ultra-low-power free-running ring oscillator and a high speed main transmitter (TX) with fast lock-in PLL. A passive wake-up receiver (WuRx) for wake-up function with a high power conversion efficiency (PCE) CMOS rectifier is designed to offer the sensor node the capability of work-on-demand with zero standby power. The chip is implemented in a 0.18 μm CMOS process. Its core area is 1.6 mm2. The main RX achieves a sensitivity of -55 dBm at a 100 kbps OOK data rate while consuming just 210 μA current from the 1 V power supply. The main TX achieves +3 dBm output power with a 4 Mbps/500 kbps/200 kbps data rate for OOK/4 FSK/2 FSK modulation and dissipates 3.25 mA/6.5 mA/6.5 mA current from a 1.8 V power supply. The minimum detectable RF input energy for the wake-up RX is -15 dBm and the PCE is more than 25%.

  4. An ultra-low-power RF transceiver for WBANs in medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qi; Wu Nanjian [State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Kuang Xiaofei, E-mail: nanjian@semi.ac.cn [College of Electronic Information, Hangzhou Dianzi University, Hangzhou 310018 (China)

    2011-06-15

    A 2.4 GHz ultra-low-power RF transceiver with a 900 MHz auxiliary wake-up link for wireless body area networks (WBANs) in medical applications is presented. The RF transceiver with an asymmetric architecture is proposed to achieve high energy efficiency according to the asymmetric communication in WBANs. The transceiver consists of a main receiver (RX) with an ultra-low-power free-running ring oscillator and a high speed main transmitter (TX) with fast lock-in PLL. A passive wake-up receiver (WuRx) for wake-up function with a high power conversion efficiency (PCE) CMOS rectifier is designed to offer the sensor node the capability of work-on-demand with zero standby power. The chip is implemented in a 0.18 {mu}m CMOS process. Its core area is 1.6 mm{sup 2}. The main RX achieves a sensitivity of -55 dBm at a 100 kbps OOK data rate while consuming just 210 {mu}A current from the 1 V power supply. The main TX achieves +3 dBm output power with a 4 Mbps/500 kbps/200 kbps data rate for OOK/4 FSK/2 FSK modulation and dissipates 3.25 mA/6.5 mA/6.5 mA current from a 1.8 V power supply. The minimum detectable RF input energy for the wake-up RX is -15 dBm and the PCE is more than 25%. (semiconductor integrated circuits)

  5. Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines

    Science.gov (United States)

    DeLaat, John C.

    2011-01-01

    Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

  6. Advanced Fuels Reactor using Aneutronic Rodless Ultra Low Aspect Ratio Tokamak Hydrogenic Plasmas

    Science.gov (United States)

    Ribeiro, Celso

    2015-11-01

    The use of advanced fuels for fusion reactor is conventionally envisaged for field reversed configuration (FRC) devices. It is proposed here a preliminary study about the use of these fuels but on an aneutronic Rodless Ultra Low Aspect Ratio (RULART) hydrogenic plasmas. The idea is to inject micro-size boron pellets vertically at the inboard side (HFS, where TF is very high and the tokamak electron temperature is relatively low because of profile), synchronised with a proton NBI pointed to this region. Therefore, p-B reactions should occur and alpha particles produced. These pellets will act as an edge-like disturbance only (cp. killer pellet, although the vertical HFS should make this less critical, since the unablated part should appear in the bottom of the device). The boron cloud will appear at midplance, possibly as a MARFE-look like. Scaling of the p-B reactions by varying the NBI energy should be compared with the predictions of nuclear physics. This could be an alternative to the FRC approach, without the difficulties of the optimization of the FRC low confinement time. Instead, a robust good tokamak confinement with high local HFS TF (enhanced due to the ultra low aspect ratio and low pitch angle) is used. The plasma central post makes the RULART concept attractive because of the proximity of NBI path and also because a fraction of born alphas will cross the plasma post and dragged into it in the direction of the central plasma post current, escaping vertically into a hole in the bias plate and reaching the direct electricity converter, such as in the FRC concept.

  7. Seismic design technology for breeder reactor structures. Volume 1. Special topics in earthquake ground motion

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, D.P.

    1983-04-01

    This report is divided into twelve chapters: seismic hazard analysis procedures, statistical and probabilistic considerations, vertical ground motion characteristics, vertical ground response spectrum shapes, effects of inclined rock strata on site response, correlation of ground response spectra with intensity, intensity attenuation relationships, peak ground acceleration in the very mean field, statistical analysis of response spectral amplitudes, contributions of body and surface waves, evaluation of ground motion characteristics, and design earthquake motions. (DLC)

  8. Ultra-low inductance design for a GaN HEMT based 3L-ANPC inverter

    OpenAIRE

    Gurpinar, Emre; Castellazzi, Alberto; Iannuzzo, Francesco; Yang, Yongheng; Blaabjerg, Frede

    2016-01-01

    In this paper, an ultra-low inductance power cell design for a 3L-ANPC based on 650 V GaN HEMT devices is presented. The 3L-ANPC topology with GaN HEMT devices and the selected modulation scheme suitable for wide-bandgap (WBG) devices are presented. The commutation loops, which are the main contributors to voltage overshoots and increase of switching losses, are discussed. The ultra-low inductance power cell design based on a four layer PCB with the aim to maximise the switching performance o...

  9. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 21. Ground water movement and nuclide transport

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    This volume, TM-36/21 Ground Water Movement and Nuclide Transport, is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-36'' which supplements a ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-44.'' The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling of spent fuel and uranium-only recycling. The studies presented in this volume consider the effect of the construction of the repository and the consequent heat generation on the ground water movement. Additionally, the source concentrations and leach rates of selected radionuclides were studied in relation to the estimated ground water inflow rates. Studies were also performed to evaluate the long term migration of radionuclides as affected by the ground water flow. In all these studies, three geologic environments are considered; granite, shale and basalt.

  10. Ultra low emission vehicle development: a study on the drivers for car firms and the implications for sustainable development policy

    NARCIS (Netherlands)

    Dijk, M.; Montalvo Corral, C.

    2009-01-01

    This paper studies the factors that lead automotive manufacturing firms to invest in Ultra Low Emission Vehicles (ULEVs). ULEVs are vehicles that emit extremely low levels of harmful gases compared to other vehicles. In contrast to studies that examine aggregated patterns on the market (such as

  11. Ultra low emission vehicle development: a study on the drivers for car firms and the implications for sustainable development policy

    NARCIS (Netherlands)

    Dijk, M.; Montalvo Corral, C.

    2009-01-01

    This paper studies the factors that lead automotive manufacturing firms to invest in Ultra Low Emission Vehicles (ULEVs). ULEVs are vehicles that emit extremely low levels of harmful gases compared to other vehicles. In contrast to studies that examine aggregated patterns on the market (such as sale

  12. A 3μW fully-differential RF envelope detector for ultra-low power receivers

    NARCIS (Netherlands)

    Liempd, B.W.M. van; Vidojkovic, M.; Lont, M.; Zhou, C.; Harpe, P.; Milosevic, D.; Dolmans, G.

    2012-01-01

    A fully differential envelope detector (ED) operating at 2.4GHz is designed in 90nm CMOS technology. The new design uses the common-gate topology to deal with large common-mode input signals through first-order current cancellation. Thereby, a fully differential ultra-low power super-regenerative fr

  13. Ultra-Low Inductance Design for a GaN HEMT Based 3L-ANPC Inverter

    DEFF Research Database (Denmark)

    Gurpinar, Emre; Castellazzi, Alberto; Iannuzzo, Francesco;

    2016-01-01

    In this paper, an ultra-low inductance power cell design for a 3L-ANPC based on 650 V GaN HEMT devices is presented. The 3L-ANPC topology with GaN HEMT devices and the selected modulation scheme suitable for wide-bandgap (WBG) devices are presented. The commutation loops, which are the main contr...

  14. Activation of JNK pathway in spinal astrocytes contributes to acute ultra-low-dose morphine thermal hyperalgesia.

    Science.gov (United States)

    Sanna, Maria Domenica; Ghelardini, Carla; Galeotti, Nicoletta

    2015-07-01

    Accumulating evidence suggests that opioid analgesics can lead to paradoxical sensitization to pain when delivered in different administration patterns. Although opioid tolerance-induced hyperalgesia is largely studied, little is known about the mechanisms underlying acute ultra-low-dose morphine hyperalgesia. Activation of spinal glial cells is reported to regulate pain hypersensitivity. To elucidate the mechanism involved in acute ultra-low-dose morphine hyperalgesia, we tested whether an opioid agonist promoted the activation of spinal astrocytes and microglia and investigated the cellular pathways involved. Ultra-low-dose morphine activated spinal astrocytes with no effect on microglia. The astrocyte activation was selectively prevented by the opioid antagonist naloxone, the μ-opioid receptor (MOR) silencing and the JNK inhibitor SP600125. Morphine elevated spinal JNK1, JNK2, and c-Jun phosphorylation. Conversely, phosphorylation of cAMP response element-binding protein (CREB) and signal transducer and activator of transcription-1 (STAT-1) was not elevated, and nuclear factor kappa B (NF-κB) levels remained unmodified. Administration of SP600125 and the N-methyl-D-aspartate (NMDA) antagonist MK801 prevented morphine hyperalgesia. Ultra-low-dose morphine increased protein kinase C (PKC) γ phosphorylation. Pretreatment with a PKC inhibitor prevented morphine hyperalgesia and JNK and c-Jun overphosphorylation, indicating PKC is a JNK upstream modulator and illustrating the presence of a pathway involving PKC, NMDA, and JNK activated by morphine. Immunofluorescence experiments indicated the neuronal localization of spinal MOR. However, JNK was not detected in MOR-expressing cells, showing the presence of a neuron-astrocyte signaling pathway. These results illustrate the selective activation of an astrocyte JNK pathway after the stimulation of neuronal MOR, which contributes to ultra-low-dose morphine hyperalgesia.

  15. DEVELOPMENT AND DEMONSTRATION OF AN ULTRA LOW NOx COMBUSTOR FOR GAS TURBINES

    Energy Technology Data Exchange (ETDEWEB)

    NEIL K. MCDOUGALD

    2005-04-30

    Alzeta Corporation has developed surface-stabilized fuel injectors for use with lean premixed combustors which provide extended turndown and ultra-low NOX emission performance. These injectors use a patented technique to form interacting radiant and blue-flame zones immediately above a selectively-perforated porous metal surface. This allows stable operation at low reaction temperatures. This technology is being commercialized under the product name nanoSTAR. Initial tests demonstrated low NOX emissions but, were limited by flashback failure of the injectors. The weld seams required to form cylindrical injectors from flat sheet material were identified as the cause of the failures. The approach for this project was to first develop new fabrication methods to produce injectors without weld seams, verify similar emissions performance to the original flat sheet material and then develop products for microturbines and small gas turbines along parallel development paths. A 37 month project was completed to develop and test a surface stabilized combustion system for gas turbine applications. New fabrication techniques developed removed a technological barrier to the success of the product by elimination of conductive weld seams from the injector surface. The injectors demonstrated ultra low emissions in rig tests conducted under gas turbine operating conditions. The ability for injectors to share a common combustion chamber allowing for deployment in annular combustion liner was also demonstrated. Some further development is required to resolve integration issues related to specific engine constraints, but the nanoSTAR technology has clearly demonstrated its low emissions potential. The overall project conclusions can be summarized: (1) A wet-laid casting method successfully eliminated weld seams from the injector surface without degrading performance. (2) Gas turbine cycle analysis identified several injector designs and control schemes to start and load engines using

  16. Ultra-Low-Noise Sub-mm/Far-IR Detectors for Space-Based Telescopes

    Science.gov (United States)

    Rostem, Karwan

    The sub-mm and Far-IR spectrum is rich with information from a wide range of astrophysical sources, including exoplanet atmospheres and galaxies at the peak star formation. In the 10-400 μm range, the spectral lines of important chemical species such H2O, HD, and [OI] can be used to map the formation and evolution of planetary systems. Dust emission in this spectral range is also an important tool for characterizing the morphology of debris disks and interstellar magnetic fields. At larger scales, accessing the formation and distribution of luminous Far-IR and sub-mm galaxies is essential to understanding star formation triggers, as well as the last stages of reionization at z 6. Detector technology is essential to realizing the full science potential of a next-generation Far-IR space telescope (Far-IR Surveyor). The technology gap in large-format, low-noise and ultra-low-noise Far-IR direct detectors is specifically highlighted by NASA's Cosmic Origins Program, and prioritized for development now to enable a flagship mission such as the Far-IR Surveyor that will address the key Cosmic Origins science questions of the next two decades. The detector requirements for a mid-resolution spectrometer are as follows: (1) Highly sensitive detectors with performance approaching 10^-19 - 10^-20 WHz 1/2 for background- limited operation in telescopes with cold optics. (2) Detector time constant in the sub- millisecond range. (3) Scalable architecture to a kilo pixel array with uniform detector characteristics. (4) Compatibility with space operation in the presence of particle radiation. We propose phononic crystals to meet the requirements of ultra-low-noise thermal detectors. By design, a phononic crystal exhibits phonon bandgaps where heat transport is forbidden. The size and location of the bandgaps depend on the elastic properties of the dielectric and the geometry of the phononic unit cell. A wide-bandwidth low-pass thermal filter with a cut-off frequency of 1.5 GHz and

  17. Thermal Transient Measurements of an Ultra-Low-Power MOX Sensor

    Directory of Open Access Journals (Sweden)

    F. Rastrello

    2010-01-01

    Full Text Available This paper describes a system for the simultaneous dynamic control and thermal characterization of the heating of an Ultra Low Power (ULP micromachined sensor. A Pulse Width Modulated (PWM powering system has been realized using a microcontroller to characterize the thermal behavior of a device. Objectives of the research were to analyze the relation between the time period and duty cycle of the PWM signal and the operating temperature of such ULP micromachined systems, to observe the thermal time constants of the device during the heating phase and to measure the total thermal conductance. Constant target heater resistance experiments highlighted that an approximately constant heater temperature at regime can only be obtained if the time period of the heating signal is smaller than 50 s. Constant power experiments show quantitatively a thermal time constant that decreases during heating in a range from 2.3 ms to 2 ms as a function of an increasing temperature rise Δ between the ambient and the operating temperature. Moreover, we calculated the total thermal conductance. Finally, repeatability of experimental results was assessed by guaranteeing the standard deviation of the controlled temperature which was within ±5.5∘C in worst case conditions.

  18. Progress on detection of liquid explosives using ultra-low field MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Volegov, Petr L [Los Alamos National Laboratory; Schuttz, Larry M [Los Alamos National Laboratory; Baguisa, Shermiyah [Los Alamos National Laboratory; Dunkerley, David [Los Alamos National Laboratory; Magnelind, Per [Los Alamos National Laboratory; Owens, Tuba [Los Alamos National Laboratory; Sandin, Henrik [Los Alamos National Laboratory; Urbaitis, Algis [Los Alamos National Laboratory

    2010-01-01

    Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) methods are widely used in medicine, chemistry and industry. Over the past several years there has been increasing interest in performing NMR and MRI in the ultra-low field (ULF) regime, with measurement field strengths of 10-100 microTesla and pre-polarization fields of 30-50 mTesla. The real-time signal-to-noise ratio for such measurements is about 100. Our group at LANL has built and demonstrated the performance of SQUID-based ULF NMR/MRI instrumentation for classification of materials and detection of liquid explosives via their relaxation properties measured at ULF, using T{sub 1}, and T{sub 2}, and T{sub 1} frequency dispersion. We are also beginning to investigate the performance of induction coils as sensors. Here we present recent progress on the applications of ULF MR to the detection of liquid explosives, in imaging and relaxometry.

  19. Development of a dedicated ethanol ultra-low emission vehicle (ULEV): Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dodge, L.; Bourn, G.; Callahan, T.; Grogan, J.; Leone, D.; Naegeli, D.; Shouse, K.; Thring, R.; Whitney, K. [Southwest Research Inst., San Antonio, TX (United States)

    1998-09-01

    The objective of this project was to develop a commercially competitive vehicle powered by ethanol (or an ethanol blend) that can meet California`s ultra-low emission vehicle (ULEV) standards and equivalent corporate average fuel economy (CAFE) energy efficiency for a light-duty passenger car application. The definition of commercially competitive is independent of fuel cost, but does include technical requirements for competitive power, performance, refueling times, vehicle range, driveability, fuel handling safety, and overall emissions performance. This report summarizes the fourth and final phase of this project, and also the overall project. The focus of this report is the technology used to develop a dedicated ethanol-fueled ULEV, and the emissions results documenting ULV performance. Some of the details for the control system and hardware changes are presented in two appendices that are SAE papers. The demonstrator vehicle has a number of advanced technological features, but it is currently configured with standard original equipment manufacturer (OEM) under-engine catalysts. Close-coupled catalysts would improve emissions results further, but no close-coupled catalysts were available for this testing. Recently, close-coupled catalysts were obtained, but installation and testing will be performed in the future. This report also briefly summarizes work in several other related areas that supported the demonstrator vehicle work.

  20. Effect of preparation parameters on ultra low molecular weight chitosan/hyaluronic acid nanoparticles.

    Science.gov (United States)

    Nazeri, Niloofar; Avadi, Mohammad Reza; Faramarzi, Mohammad Ali; Safarian, Shahrokh; Tavoosidana, Gholamreza; Khoshayand, Mohammad Reza; Amani, Amir

    2013-11-01

    Nanoparticles of ultra low molecular weight chitosan (ULMWCS)/hyaluronic acid (HA) were prepared by ion gelation. Three independent variables, namely, ratio of concentration of ULMWCS to HA (CS/HA), pH of solution and stirring time were studied to identify their effects on size, polydispersity and zeta potential of prepared nanoparticles using a Box-Behnken design. Results showed that pH and CS/HA have a direct effect on size, while increase of stirring time decreases the size of nanoparticles. Additionally, it was shown that all the independent parameters have direct effects on zeta potential. Also, the minimum polydispersity index was observed at lowest values of CS/HA. The model also predicted that the optimum values are 4.15, 4.14 and 180 (min) for the CS/HA, solution pH and stirring time, respectively. The obtained preparation had a size of 200 nm, polydispersity index of 0.37, and zeta potential of 13.0 mV.

  1. Ultra-low frequency vertical vibration isolator based on LaCoste spring linkage

    Science.gov (United States)

    Li, G.; Hu, H.; Wu, K.; Wang, G.; Wang, L. J.

    2014-10-01

    For the applications in precision measurement such as absolute gravimeter, we have designed and built an ultra-low frequency vertical vibration isolator based on LaCoste spring linkage. In the system, an arm with test mass is suspended by a mechanical extension spring, and one end of the arm is connected to the frame with flexible pivots. The displacement of the arm is detected by an optical reflection method. With the displacement signal, a feedback control force is exerted on the arm to keep it at the balance position. This method can also correct the systematic drift caused by temperature change. In order to study the vibration isolation performance of the system, we analyze the dynamic characteristics of the spring linkage in the general case, and present key methods to adjust the natural oscillating period of the system. With careful adjustment, the system can achieve a steady oscillation with a natural period up to 32 s. This isolator has been tested based on the T-1 absolute gravimeter. A statistical uncertainty of 2 μGal has been achieved within a typical 12 h measurement. The experimental results verify that the isolator has significant vibration isolation performance, and it is very suitable for applications in high precision absolute gravity measurement.

  2. Low-Voltage Ultra-Low-Power Current Conveyor Based on Quasi-Floating Gate Transistors

    Directory of Open Access Journals (Sweden)

    F. Khateb

    2012-06-01

    Full Text Available The field of low-voltage low-power CMOS technology has grown rapidly in recent years; it is an essential prerequisite particularly for portable electronic equipment and implantable medical devices due to its influence on battery lifetime. Recently, significant improvements in implementing circuits working in the low-voltage low-power area have been achieved, but circuit designers face severe challenges when trying to improve or even maintain the circuit performance with reduced supply voltage. In this paper, a low-voltage ultra-low-power current conveyor second generation CCII based on quasi-floating gate transistors is presented. The proposed circuit operates at a very low supply voltage of only ±0.4 V with rail-to-rail voltage swing capability and a total quiescent power consumption of mere 9.5 µW. Further, the proposed circuit is not only able to process the AC signal as it's usual at quasi-floating gate transistors but also the DC which extends the applicability of the proposed circuit. In conclusion, an application example of the current-mode quadrature oscillator is presented. PSpice simulation results using the 0.18 µm TSMC CMOS technology are included to confirm the attractive properties of the proposed circuit.

  3. Ultra-low velocity zone heterogeneities at the core-mantle boundary from diffracted PKKPab waves

    Science.gov (United States)

    Ma, Xiaolong; Sun, Xinlei

    2017-08-01

    Diffracted waves around Earth's core could provide important information of the lowermost mantle that other seismic waves may not. We examined PKKPab diffraction waves from 52 earthquakes occurring at the western Pacific region and recorded by USArray to probe the velocity structure along the core-mantle boundary (CMB). These diffracted waves emerge at distances up to 10° past the theoretical cutoff epicentral distance and show comparable amplitudes. We measured the ray parameters of PKKPab diffraction waves by Radon transform analysis that is suitable for large-aperture arrays. These ray parameters show a wide range of values from 4.250 to 4.840 s/deg, suggesting strong lateral heterogeneities in sampling regions at the base of the mantle. We further estimated the P-wave velocity variations by converting these ray parameters and found the CMB regions beneath the northwestern edge of African Anomaly (Ritsma et al. in Science 286:1925-1928, 1999) and southern Sumatra Islands exhibit velocity reductions up to 8.5% relative to PREM. We suggest that these low velocity regions are Ultra-low velocity zones, which may be related to partial melt or iron-enriched solids.[Figure not available: see fulltext.

  4. Development of an Ultra-Low Background Liquid Scintillation Counter for Trace Level Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Erchinger, Jennifer L.; Orrell, John L.; Aalseth, Craig E.; Bernacki, Bruce E.; Douglas, Matthew; Finn, Erin C.; Fuller, Erin S.; Keillor, Martin E.; Morley, Shannon M.; Mullen, Crystal A.; Panisko, Mark E.; Shaff, Sarah M.; Warren, Glen A.; Wright, Michael E.

    2015-09-01

    Low-level liquid scintillation counting (LSC) has been established as one of the radiation detection techniques useful in elucidating environmental processes and environmental monitoring around nuclear facilities. The Ultra-Low Background Liquid Scintillation Counter (ULB-LSC) under construction in the Shallow Underground Laboratory at Pacific Northwest National Laboratory aims to further reduce the MDAs and/or required sample processing. Through layers of passive shielding in conjunction with an active veto and 30 meters water equivalent overburden, the background reduction is expected to be 10 to 100 times below typical analytic low-background liquid scintillation systems. Simulations have shown an expected background of around 14 counts per day. A novel approach to the light collection will use a coated hollow light guide cut into the inner copper shielding. Demonstration LSC measurements will show low-energy detection, spectral deconvolution, and alpha/beta discrimination capabilities, from trials with standards of tritium, strontium-90, and actinium-227, respectively. An overview of the system design and expected demonstration measurements will emphasize the potential applications of the ULB-LSC in environmental monitoring for treaty verification, reach-back sample analysis, and facility inspections.

  5. Low scatter and ultra-low reflectivity measured in a fused silica window

    CERN Document Server

    Padilla, Cinthia; Muniz, Erik; Smith, Joshua R; Fritschel, Peter; Zhang, Liyuan

    2013-01-01

    We investigate the reflectivity and optical scattering characteristics at 1064\\,nm of an antireflection coated fused silica window of the type being used in the Advanced LIGO gravitational-wave detectors. Reflectivity is measured in the ultra-low range of 5-10\\,ppm (by vendor) and 14-30\\,ppm (by us). Using an angle-resolved scatterometer we measure the sample's Bidirectional Scattering Distribution Function (BSDF) and use this to estimate its transmitted and reflected scatter at roughly 20-40\\,ppm and 1\\,ppm, respectively, over the range of angles measured. We further inspect the sample's low backscatter using an imaging scatterometer, measuring an angle resolved BSDF below $10^{-6}$ sr$^{-1}$ for large angles (10$^\\circ$--80$^\\circ$ from incidence in the plane of the beam). We use the associated images to (partially) isolate scatter from different regions of the sample and find that scattering from the bulk fused silica is on par with backscatter from the antireflection coated optical surfaces. To confirm th...

  6. Research and Development of Natural Draft Ultra-Low Emissions Burners for Gas Appliances

    Energy Technology Data Exchange (ETDEWEB)

    Therkelsen, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sholes, Darren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-08-31

    Combustion systems used in residential and commercial cooking appliances must be robust and easy to use while meeting air quality standards. Current air quality standards for cooking appliances are far greater than other stationary combustion equipment. By developing an advanced low emission combustion system for cooking appliances, the air quality impacts from these devices can be reduced. This project adapted the Lawrence Berkeley National Laboratory (LBNL) Ring-Stabilizer Burner combustion technology for residential and commercial natural gas fired cooking appliances (such as ovens, ranges, and cooktops). LBNL originally developed the Ring-Stabilizer Burner for a NASA funded microgravity experiment. This natural draft combustion technology reduces NOx emissions significantly below current SCAQMD emissions standards without post combustion treatment. Additionally, the Ring-Stabilizer Burner technology does not require the assistance of a blower to achieve an ultra-low emission lean premix flame. The research team evaluated the Ring-Stabilizer Burner and fabricated the most promising designs based on their emissions and turndown.

  7. Ultra low and negative expansion glass–ceramic materials produced from pyrophyllite and blast furnace slag

    Indian Academy of Sciences (India)

    S Mandal; S Chakrabarti; S Ghatak; S K Das

    2005-08-01

    Ultra low and negative expansion glass–ceramic materials have been obtained from pyrophyllite and blast furnace slag. The batch composition was modified with the addition of lithium carbonate, hydrated alumina, boric acid and nucleating agent (titania). The batch was melted at 1400°C followed by casting in the form of bars and annealed at 510°C for 4 h. The annealed specimens were subjected to heat treatment at predetermined temperatures selected from DTA study of the parent glass. Thermal expansion measurement and X-ray diffraction analysis revealed that the specimen nucleated at 545°C for 4 h and crystallized at 720°C for 2 h which resulted in negative coefficient of thermal expansion [(–) 9 to (–) 2 × 10$^{-7}/{}^\\circ $C] over the temperature range (30–600°C) due to the formation of -eucryptite while other heating schedule showed the formation of spodumene and lithium aluminium silicates. The samples showed excellent flexural strength value and varied in the range 120–200 MPa depending upon the phases present.

  8. Performance comparison between rapid sequencing platforms for ultra-low coverage sequencing strategy.

    Directory of Open Access Journals (Sweden)

    Shengpei Chen

    Full Text Available Ultra-low coverage sequencing (ULCS is one of the most promising strategies for sequencing based clinical application. These clinical applications, especially prenatal diagnosis, have a strict requirement of turn-around-time; therefore, the application of ULCS is restricted by current high throughput sequencing platforms. Recently, the emergence of rapid sequencing platforms, such as MiSeq and Ion Proton, brings ULCS strategy into a new era. The comparison of their performance could shed lights on their potential application in large-scale clinic trials. In this study, we performed ULCS (<0.1X coverage on both MiSeq and Ion Proton platforms for 18 spontaneous abortion fetuses carrying aneuploidy and compared their performance on different levels. Overall basic data and GC bias showed no significant difference between these two platforms. We also found the sex and aneuploidy detection indicated 100% sensitivity and 100% specificity on both platforms. Our study generated essential data from these two rapid sequencing platforms, which provides useful reference for later research and potentially accelerates the clinical applications of ULCS.

  9. Ultra low fluence rate photodynamic therapy: simulation of light emitted by the Cerenkov effect

    Science.gov (United States)

    Gonzales, Jonathan; Wang, Fred; Zamora, Genesis; Trinidad, Anthony; Marcu, Laura; Cherry, Simon; Hirschberg, Henry

    2014-03-01

    PDT has been shown to be most effective at low fluence rates. Many radionuclides used for both diagnostic and therapeutic purposes produce measurable amounts of visible radiation when they decay via the Cerenkov effect which occurs when a charged particle travels faster in a dielectric medium than the speed of light in that medium. Cerenkov radiation from radiopharmaceuticals could serve as a source of extended duration, low level "internal" light, to mediate PDT, with the ultimate goals of overcoming some its current limitations. Using laser light, we are exploring the effects of fluence rates that could be generated by Cerenkov radiation on PDT efficacy. ALA or TPPS2a mediated PDT of rat gliomas monolayers or multicell spheroids ( F98, C6) was performed with 410 nm laser light exposure over an extended period of 24-96hrs. Photosensitizers were delivered either as a bolus or continuously with light exposure. At fluence rate of 20μW/cm2 effective PDT was obtained as measured by decrease in cell viability or inhibition of spheroid growth. PDT is effective at ultra low fluence rates if given over long time periods. No lower threshold has been ascertained. Since the half-life of 90Y, a radionuclide with a high Cherenkov yield is 64 hrs it is a good candidate to supply sufficient light activation for PDT. The combination of radionuclide and photodynamic therapies could improve the effectiveness of cancer treatment by exploiting synergies between these two modalities.

  10. Fabrication of mesoporous silica for ultra-low-k interlayer dielectrics

    Science.gov (United States)

    Fujii, Nobutoshi; Kohmura, Kazuo; Nakayama, Takahiro; Tanaka, Hirofumi; Hata, Nobuhiro; Seino, Yutaka; Kikkawa, Takamaro

    2005-11-01

    We have developed sol-gel self-assembly techniques to control the pore structure and diameter of ultra-low-k interlayer dielectric (ILD) films. Porous silica films have been fabricated using cationic and nonionic surfactants as templates, resulting in 2D-hexagonal and disordered pore structures, respectively. The disordered mesoporous silica film has a worm-hole like network of pore channels having a uniform diameter. Precursors of the mesoporous silica films were synthesized by use of tetraethyl-orthosilicate (TEOS), inorganic acid, water, ethanol and various surfactants. The surfactants used were cationic alkyltrimethyl-ammonium (ATMA) chloride surfactants for 2D-hexagonal pores and nonionic tri-block copolymer for disordered structures. Dimethyldiethoxysilane (DMDEOS) was added for forming the disordered mesoporous silica. The disordered cylindrical pore structure with a uniform pore size was fabricated by controlling the static electrical interaction between the surfactant and the silica oligomer with methyl group of DMDEOS. Tetramethylcycrotetrasiloxane (TMCTS) vapor treatment was developed, which improved the mechanical strength of mesoporous silica films. The TMCTS polymer covered the pore wall surface and cross-linked to passivate the mechanical defects in the silica wall. Significant enhancement of mechanical strength was demonstrated by TMCTS vapor treatment. The porous silica film modified with a catalyst and a plasma treatment achieved higher mechanical strength and lower dielectric constant than conventional porous silica films because the TMCTS vapor treatment was more effective for mechanical reinforcement and hydrophobicity.

  11. Experimental evaluation on well pattern adaptability of ultra-low permeability reservoir using sandstone flat model

    Institute of Scientific and Technical Information of China (English)

    肖前华; 魏国齐; 杨正明; 徐轩; 田文博; 张亚蒲

    2014-01-01

    As for ultra-low permeability reservoir, the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops. Combined with non-linear porous flow characteristics, the concept of dimensionless pressure sweep efficiency and deliverability index are put forward to evaluate the physical models’ well pattern adaptability. Through experiments, the models’ pressure distribution is measured and on which basis, the pressure gradient fields are drawn and the porous flow regions of these models are divided into dead oil region, non-linear porous flow region, and quasi-linear porous flow region with the help of twin-core non-linear porous flow curve. The results indicate that rectangular well pattern in fracture reservoirs has the best adaptability, while the worst is inverted nine-spot equilateral well pattern. With the increase of drawdown pressure, dead oil region decreases, pressure sweep efficiency and deliverability index increase; meantime, the deliverability index of rectangular well pattern has much more rational increase. Under the same drawdown pressure, the rectangular well pattern has the largest pressure sweep efficiency.

  12. Effect of Si-Al Compounds on Fire Properties of Ultra-low Density Fiberboard

    Directory of Open Access Journals (Sweden)

    Min Niu

    2014-03-01

    Full Text Available An ultra-low density fiberboard was made of plant fiber using a liquid frothing approach. The inflammability of the plant fiber limited its application as a candidate for building insulation materials and packaging buffering materials. Si-Al compounds were introduced into the foaming system because of the high temperature resistance of Si and Al compounds. The results from energy-dispersive spectroscopy suggested that the Si and Al relatively evenly covered the surface of the fibers, and their weight ratios in the material increased as a function of the amount of Si-Al compounds. The increasing weight ratios of Si and Al affected the fire properties of the material, reducing the released amount of heat, smoke, and off-gases such as CO and CO2, as well as decreasing the mass loss percentage, shown through the use of a Cone Calorimeter. It follows that Si-Al compounds have an evident collaborative effect on the halogen fire retardant. The system can effectively restrain the fire hazard intensity and the yields of solid and gas volatiles.

  13. An ultra-low noise optical head for liquid environment atomic force microscopy.

    Science.gov (United States)

    Schlesinger, I; Kuchuk, K; Sivan, U

    2015-08-01

    The design considerations and eventual performance of a new, ultra-low noise optical head for dynamic atomic force microscopy (AFM) are presented. The head, designed specifically for the study of hydration layers and ion organization next to solid surfaces and biomolecules, displays an integrated tip-sample distance noise below 3 pm. The sensitivity of the optical beam deflection sensor, operating at frequencies up to 8.6 MHz (3 dB roll-off), is typically below 10 fm/√Hz, enabling utilization of high frequency cantilevers of low thermal noise for fundamental and higher mode imaging. Exceptional signal stability and low optical noise are achieved by replacing the commonly used laser diode with a helium-neon laser. An integral photothermal excitation of the cantilever produces pure harmonic oscillations, minimizing the generation of higher cantilever modes and deleterious sound waves characterizing the commonly used excitation by a piezoelectric crystal. The optical head is designed to fit on top of the widespread Multimode(®) (Bruker) piezo-tube and accommodate its commercial liquid cell. The performance of the new AFM head is demonstrated by atomic resolution imaging of a muscovite mica surface in aqueous solution.

  14. Ultra-low background retrieval of photons stored in warm Rb vapor

    Science.gov (United States)

    Figueroa, Eden; Neuzner, Andreas; Latka, Tobias; Schupp, Josef; Noelleke, Christian; Reiserer, Andreas; Ritter, Stephan; Rempe, Gerhard

    2013-05-01

    The development of a simple and inexpensive platform for interconnecting light and matter at the quantum level has recently emerged as one of the key challenges of the rapidly evolving field of quantum engineering. Although elementary quantum memory capabilities have been already shown using ensembles of cold atoms or single-atoms in optical cavities, a scalable-friendly architecture might still require room temperature operation. Here we use an ensemble of Rb atoms in the gaseous state and store light pulses at the single-photon level to demonstrate that even in a common vapor cell it is possible to achieve quantum-level operation with ultra-low background noise. We have obtained a measured signal- to-background noise ratio of 3.5, which is the first time this figure of merit has been lifted beyond unity for experiments with room temperature operation. In addition, we also show the capabilities of the system to arbitrarily tailor the temporal properties of the retrieved single-photon-level pulses.

  15. Cryo ultra-low-angle microtomy for XPS-depth profiling of organic coatings.

    Science.gov (United States)

    Greunz, T; Strauß, B; Schausberger, S E; Heise, B; Jachs, B; Stifter, D

    2013-09-01

    In X-ray photoelectron spectroscopy (XPS) Ar(+) ion sputtering is usually used for depth profiling. However, for such samples as organic coatings, this is not feasible because of degradation. Also, measurement of a depth profile on a conventionally prepared cross-section is not possible if, for example, sample thickness is below the smallest available measurement spot size of the XPS system. In our approach we used a rotary microtome to cut samples under a shallow tilting angle of 0.5° to obtain an extended cross-section suitable for XPS investigations. We also used liquid nitrogen cooling to ensure an exposed area of higher quality: topography measurements with a novel optical 3D microscope and by atomic force microscopy revealed the linearity of the inclined sections. With our cryo ultra-low-angle microtomy (cryo-ULAM) preparation technique we were able to determine, by XPS, elemental and chemical gradients within a 25 μm thick polyester-based organic coating deposited on steel. The gradients were related to, for example, depletion of the crosslinking agent in the sub-surface region. Complementary reflection electron energy-loss spectroscopy measurements performed on the cryo-ULAM sections also support the findings obtained from the XPS depth profiles.

  16. Conductive shield for ultra-low-field magnetic resonance imaging: Theory and measurements of eddy currents

    Science.gov (United States)

    Zevenhoven, Koos C. J.; Busch, Sarah; Hatridge, Michael; Öisjöen, Fredrik; Ilmoniemi, Risto J.; Clarke, John

    2014-03-01

    Eddy currents induced by applied magnetic-field pulses have been a common issue in ultra-low-field magnetic resonance imaging. In particular, a relatively large prepolarizing field—applied before each signal acquisition sequence to increase the signal—induces currents in the walls of the surrounding conductive shielded room. The magnetic-field transient generated by the eddy currents may cause severe image distortions and signal loss, especially with the large prepolarizing coils designed for in vivo imaging. We derive a theory of eddy currents in thin conducting structures and enclosures to provide intuitive understanding and efficient computations. We present detailed measurements of the eddy-current patterns and their time evolution in a previous-generation shielded room. The analysis led to the design and construction of a new shielded room with symmetrically placed 1.6-mm-thick aluminum sheets that were weakly coupled electrically. The currents flowing around the entire room were heavily damped, resulting in a decay time constant of about 6 ms for both the measured and computed field transients. The measured eddy-current vector maps were in excellent agreement with predictions based on the theory, suggesting that both the experimental methods and the theory were successful and could be applied to a wide variety of thin conducting structures.

  17. Linear-phase delay filters for ultra-low-power signal processing in neural recording implants.

    Science.gov (United States)

    Gosselin, Benoit; Sawan, Mohamad; Kerherve, Eric

    2010-06-01

    We present the design and implementation of linear-phase delay filters for ultra-low-power signal processing in neural recording implants. We use these filters as low-distortion delay elements along with an automatic biopotential detector to perform integral waveform extraction and efficient power management. The presented delay elements are realized employing continuous-time OTA-C filters featuring 9th-order equiripple transfer functions with constant group delay. Such analog delay enables processing neural waveforms with reduced overhead compared to a digital delay since it does not requires sampling and digitization. It uses an allpass transfer function for achieving wider constant-delay bandwidth than all-pole does. Two filters realizations are compared for implementing the delay element: the Cascaded structure and the Inverse follow-the-leader feedback filter. Their respective strengths and drawbacks are assessed by modeling parasitics and non-idealities of OTAs, and by transistor-level simulations. A budget of 200 nA is used in both filters. Experimental measurements with the chosen filter topology are presented and discussed.

  18. Synthesis of Petroleum Sulfonate Surfactant with Ultra-Low Interfacial Tension in Rotating Packed Bed Reactor

    Institute of Scientific and Technical Information of China (English)

    Weng Zhan; Zhang Pengyuan; Chu Guangwen; Zou Haikui; Jimmy Yun; Chen Jianfeng

    2015-01-01

    Petroleum sulfonate is one of the most important surfactants used in surfactant lfooding for enhanced oil recov-ery, which is mainly obtained by treating high-boiling petroleum fractions in a stirred tank reactor (STR) or in a falling-iflm reactor (FFR). The synthesis of petroleum sulfonate with ultra-low interfacial tension from viscous petroleum fractions was carried out in a rotating packed bed (RPB) reactor using dilute liquid sulfur trioxide as the sulfonating agent in this study. The effects of various experimental conditions on components content and oil-water interfacial tension (IFT) were investigated. Under the optimum conditions, the active matter content could reach up to 50.3% and the IFT could be equal to 4.7×10−3 mN/m. Compared with the traditional reactor, the active matter content is by 14.12% higher in the RPB as compared to that obtained in the STR. The uneven change of the test oil droplets during the IFT measurement was also dis-cussed. The increase of heavy components content not only can eliminate the contraction phenomenon, but also can reduce the IFT to a minimum. This can be conducive to explaining the reason for producing IFT and the preparation of proper for-mulations for practical application.

  19. Ultra-low thermal conductivities in large-area Si-Ge nanomeshes for thermoelectric applications

    Science.gov (United States)

    Perez-Taborda, Jaime Andres; Muñoz Rojo, Miguel; Maiz, Jon; Neophytou, Neophytos; Martin-Gonzalez, Marisol

    2016-01-01

    In this work, we measure the thermal and thermoelectric properties of large-area Si0.8Ge0.2 nano-meshed films fabricated by DC sputtering of Si0.8Ge0.2 on highly ordered porous alumina matrices. The Si0.8Ge0.2 film replicated the porous alumina structure resulting in nano-meshed films. Very good control of the nanomesh geometrical features (pore diameter, pitch, neck) was achieved through the alumina template, with pore diameters ranging from 294 ± 5nm down to 31 ± 4 nm. The method we developed is able to provide large areas of nano-meshes in a simple and reproducible way, being easily scalable for industrial applications. Most importantly, the thermal conductivity of the films was reduced as the diameter of the porous became smaller to values that varied from κ = 1.54 ± 0.27 W K−1m−1, down to the ultra-low κ = 0.55 ± 0.10 W K−1m−1 value. The latter is well below the amorphous limit, while the Seebeck coefficient and electrical conductivity of the material were retained. These properties, together with our large area fabrication approach, can provide an important route towards achieving high conversion efficiency, large area, and high scalable thermoelectric materials. PMID:27650202

  20. An ultra-low-voltage rectifier for PE energy harvesting applications

    Science.gov (United States)

    Jingmin, Wang; Zheng, Yang; Zhangming, Zhu; Yintang, Yang

    2016-02-01

    An ultra low voltage rectifier with high power conversion efficiency (PCE) for PE energy harvesting applications is presented in this paper. This is achieved by utilizing the DTMOS which the body terminal is connected to the gate terminal in a diode connected transistor. This implementation facilitates the rectifier with dynamic control over the threshold voltage. Moreover, we use input powered to take the place of output powered to reduce the power loss and thereby increasing the power conversion efficiency. Based on standard SMIC 0.18 μm CMOS technology, the simulation results show that the voltage conversion efficiency and the power conversion efficiency can reach up to 90.5% and 95.5% respectively, when the input voltage equals to 0.2 V @ 100 Hz with load resistance 50 kω. Input voltages with frequencies in the range of 10 Hz-1 kHz can be rectified. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033) and the National High-Tech Program of China (No. 2013AA014103).

  1. Ultra-low-dose vaginal estrogen tablets for the treatment of postmenopausal vaginal atrophy.

    Science.gov (United States)

    Simon, J A; Maamari, R V

    2013-08-01

    Vaginal atrophy is a common chronic condition affecting up to 57% of postmenopausal women. The decrease in estrogen following cessation of menses can lead to bothersome symptoms that include vaginal dryness and irritation, pain and burning during urination (dysuria), urinary tract infections, and pain (dyspareunia) and bleeding during sexual activities. These symptoms can be safely and effectively managed with the use of local estrogen therapy, which reduces the risks associated with long-term systemic hormone therapy. The ultra-low-dose 10 μg estradiol vaginal tablet is the lowest approved dose available and has an annual estradiol exposure of only 1.14 mg. Its development addresses recommendations from regulatory agencies and women's health societies regarding the use of the lowest hormonal dose. The 10 μg vaginal tablet displays minimal estradiol absorption, causes no increased risk of endometrial hyperplasia or carcinoma, and provides significant symptom relief. The clinical evidence presented here may offer greater reassurance to health-care professionals and postmenopausal women that vaginal atrophy can be treated safely and effectively.

  2. Ultra-low thermal conductivities in large-area Si-Ge nanomeshes for thermoelectric applications.

    Science.gov (United States)

    Perez-Taborda, Jaime Andres; Muñoz Rojo, Miguel; Maiz, Jon; Neophytou, Neophytos; Martin-Gonzalez, Marisol

    2016-09-21

    In this work, we measure the thermal and thermoelectric properties of large-area Si0.8Ge0.2 nano-meshed films fabricated by DC sputtering of Si0.8Ge0.2 on highly ordered porous alumina matrices. The Si0.8Ge0.2 film replicated the porous alumina structure resulting in nano-meshed films. Very good control of the nanomesh geometrical features (pore diameter, pitch, neck) was achieved through the alumina template, with pore diameters ranging from 294 ± 5nm down to 31 ± 4 nm. The method we developed is able to provide large areas of nano-meshes in a simple and reproducible way, being easily scalable for industrial applications. Most importantly, the thermal conductivity of the films was reduced as the diameter of the porous became smaller to values that varied from κ = 1.54 ± 0.27 W K(-1)m(-1), down to the ultra-low κ = 0.55 ± 0.10 W K(-1)m(-1) value. The latter is well below the amorphous limit, while the Seebeck coefficient and electrical conductivity of the material were retained. These properties, together with our large area fabrication approach, can provide an important route towards achieving high conversion efficiency, large area, and high scalable thermoelectric materials.

  3. Magnetic thin-film insulator with ultra-low spin wave damping for coherent nanomagnonics.

    Science.gov (United States)

    Yu, Haiming; Kelly, O d'Allivy; Cros, V; Bernard, R; Bortolotti, P; Anane, A; Brandl, F; Huber, R; Stasinopoulos, I; Grundler, D

    2014-10-30

    Wave control in the solid state has opened new avenues in modern information technology. Surface-acoustic-wave-based devices are found as mass market products in 100 millions of cellular phones. Spin waves (magnons) would offer a boost in today's data handling and security implementations, i.e., image processing and speech recognition. However, nanomagnonic devices realized so far suffer from the relatively short damping length in the metallic ferromagnets amounting to a few 10 micrometers typically. Here we demonstrate that nm-thick YIG films overcome the damping chasm. Using a conventional coplanar waveguide we excite a large series of short-wavelength spin waves (SWs). From the data we estimate a macroscopic of damping length of about 600 micrometers. The intrinsic damping parameter suggests even a record value about 1 mm allowing for magnonics-based nanotechnology with ultra-low damping. In addition, SWs at large wave vector are found to exhibit the non-reciprocal properties relevant for new concepts in nanoscale SW-based logics. We expect our results to provide the basis for coherent data processing with SWs at GHz rates and in large arrays of cellular magnetic arrays, thereby boosting the envisioned image processing and speech recognition.

  4. Conductive shield for ultra-low-field magnetic resonance imaging: Theory and measurements of eddy currents.

    Science.gov (United States)

    Zevenhoven, Koos C J; Busch, Sarah; Hatridge, Michael; Oisjöen, Fredrik; Ilmoniemi, Risto J; Clarke, John

    2014-03-14

    Eddy currents induced by applied magnetic-field pulses have been a common issue in ultra-low-field magnetic resonance imaging. In particular, a relatively large prepolarizing field-applied before each signal acquisition sequence to increase the signal-induces currents in the walls of the surrounding conductive shielded room. The magnetic-field transient generated by the eddy currents may cause severe image distortions and signal loss, especially with the large prepolarizing coils designed for in vivo imaging. We derive a theory of eddy currents in thin conducting structures and enclosures to provide intuitive understanding and efficient computations. We present detailed measurements of the eddy-current patterns and their time evolution in a previous-generation shielded room. The analysis led to the design and construction of a new shielded room with symmetrically placed 1.6-mm-thick aluminum sheets that were weakly coupled electrically. The currents flowing around the entire room were heavily damped, resulting in a decay time constant of about 6 ms for both the measured and computed field transients. The measured eddy-current vector maps were in excellent agreement with predictions based on the theory, suggesting that both the experimental methods and the theory were successful and could be applied to a wide variety of thin conducting structures.

  5. An ultra-low power (ULP) bandage-type ECG sensor for efficient cardiac disease management.

    Science.gov (United States)

    Shin, Kunsoo; Park, G G; Kim, J P; Lee, T H; Ko, B H; Kim, Y H

    2013-01-01

    This paper proposed an ultra-low power bandage-type ECG sensor (the size: 76 × 34 × 3 (mm(3)) and the power consumption: 1 mW) which allows for a continuous and real-time monitoring of a user's ECG signals over 24h during daily activities. For its compact size and lower power consumption, we designed the analog front-end, the SRP (Samsung Reconfigurable Processor) based DSP of 30 uW/MHz, and the ULP wireless RF of 1 nJ/bit. Also, to tackle motion artifacts(MA), a MA monitoring technique based on the HCP (Half-cell Potential) is proposed which resulted in the high correlation between the MA and the HCP, the correlation coefficient of 0.75 ± 0.18. To assess its feasibility and validity as a wearable health monitor, we performed the comparison of two ECG signals recorded form it and a conventional Holter device. As a result, the performance of the former is a little lower as compared with the latter, although showing no statistical significant difference (the quality of the signal: 94.3% vs 99.4%; the accuracy of arrhythmia detection: 93.7% vs 98.7%). With those results, it has been confirmed that it can be used as a wearable health monitor due to its comfortability, its long operation lifetime and the good quality of the measured ECG signal.

  6. An Ultra-Low Frequency Two DOFs’ Vibration Isolator Using Positive and Negative Stiffness in Parallel

    Directory of Open Access Journals (Sweden)

    Min Wang

    2016-01-01

    Full Text Available With the improvement of performance in the ultra-precision manufacturing engineering, the requirements for vibration isolation have become increasingly stringent. In order to get wider effective bandwidth and higher performance of vibration isolation in multiple DOFs system, an ultra-low frequency two DOFs’ vibration isolator with positive and negative stiffness in parallel (PNSP is proposed. The two DOFs’ isolator which combines a positive stiffness (PS air spring with a negative stiffness (NS magnetic spring in parallel and combines a PS flat spring with an NS inverted pendulum in parallel is designed to reduce the natural frequency and broaden the effective bandwidth in horizontal and vertical direction. Based on this structure, stiffness models of different components in different directions are established. Compared with a PS isolator, it possesses the characteristic of high-static-low-dynamic stiffness. The simulation curves also provide strong evidence. Last, a real-time active control system and a spectrum testing and analysis system are used for the contrast experiment between the mentioned PNSP structure and PS only. The experimental results demonstrate that the isolator with PNSP can obviously reduce the natural frequency to 1 Hz and simultaneously maintain the stability of the system and consequently verify the validity and superiority of the mentioned structure.

  7. Ultra-low-power silicon photonics wavelength converter for phase-encoded telecommunication signals

    Science.gov (United States)

    Lacava, C.; Ettabib, M. A.; Cristiani, I.; Fedeli, J.-M.; Richardson, D. J.; Petropoulos, P.

    2016-03-01

    The development of compact, low power, silicon photonics CMOS compatible components for all-optical signal processing represents a key step towards the development of fully functional platforms for next generation all-optical communication networks. The wavelength conversion functionality at key nodes is highly desirable to achieve transparent interoperability and wavelength routing allowing efficient management of network resources operated with high speed, phase encoded signals. All optical wavelength conversion has already been demonstrated in Si-based devices, mainly utilizing the strong Kerr effect that silicon exhibits at telecommunication wavelengths. Unfortunately, Two Photon Absorption (TPA) and Free Carrier (FC) effects strongly limit their performance, even at moderate power levels, making them unsuitable for practical nonlinear applications. Amorphous silicon has recently emerged as a viable alternative to crystalline silicon (c-Si), showing both an enhanced Kerr as well as a reduced TPA coefficient at telecom wavelengths, with respect to its c-Si counterpart. Here we present an ultra-low power wavelength converter based on a passive, CMOS compatible, 1-mm long amorphous silicon waveguide operated at a maximum pump power level of only 70 mW. We demonstrate TPA-free Four Wave Mixing (FWM)-based wavelength conversion of Binary Phase Shift Keyed (BPSK) and Quadrature Phase Shift Keyed (QPSK) signals at 20 Gbit/s with <1 dB power penalty at BER = 10-5.

  8. Ultra-low-dose oral contraceptive pill: a new approach to a conventional requirement

    Directory of Open Access Journals (Sweden)

    Meenakshi Ahuja

    2017-01-01

    Full Text Available Combined oral contraceptives (COCs offer a convenient, safe, effective, and reversible method of contraception. However, their use is limited by side effects. Several strategies have been suggested to make COC use more acceptable among women. Reduction in the dose of estrogen is a commonly accepted approach to reduce the side effects of COC. Use of newer generation of progestins, such as gestodene, reduces the androgenic side effects generally associated with progestogens. Furthermore, reduction in hormone-free interval, as a 24/4 regimen, can reduce the risk of escape ovulation (hence preventing contraceptive failure and breakthrough bleeding. It also reduces hormonal fluctuations, thereby reducing the withdrawal symptoms. A COC with gestodene 60 µg and ethinylestradiol (EE 15 µg offers the lowest hormonal dose in 24/4 treatment regimen. This regimen has been shown to offer good contraceptive efficacy and cycle control. With the progress of treatment cycles, the incidence of breakthrough bleeding reduces. Gestodene/EE low dose 24/4 regimen was associated with lower incidence of estrogen-related adverse events, such as headache, breast tenderness, and nausea. Furthermore, COCs containing low dose of estrogen have not been associated with any adverse effect on haemostasis in healthy women. Ultra-low-dose COCs can be considered in women who are at risk of developing estrogen-related side effects.

  9. Friction moment analysis of space gyroscope bearing with ribbon cage under ultra-low oscillatory motion

    Directory of Open Access Journals (Sweden)

    Jiang Shaona

    2014-10-01

    Full Text Available This paper presents the model of calculating the total friction moment of space gyroscope ball bearings which usually work under ultra-low oscillatory motion and are very sensitive to the friction moment. The aim is to know the proportion of the friction moment caused by each frictional source in the bearing’s total friction moment, which is helpful to optimize the bearing design to deduce the friction moment. In the model, the cage dynamic equations considering six degree-of-freedom and the balls dynamic equations considering two degree-of-freedom were solved. The good trends with different loads between the measured friction moments and computational results prove that the model under constant rate was validated. The computational results show that when the speed was set at 5 r/min, the bearing’s maximum total friction moment when oscillation occurred was obviously larger than that occurred at a constant rate. At the onset of each oscillatory motion, the proportion of the friction moment caused by cage in the bearing’s total friction moment was very high, and it increased with the increasing speed. The analyses of different cage thicknesses and different clearances between cage pocket and ball show that smaller thickness and clearance were preferred.

  10. Development of a dedicated ethanol ultra-low emission vehicle (ULEV) system design

    Energy Technology Data Exchange (ETDEWEB)

    Bourn, G.; Callahan, T.; Dodge, L.; Mulik, J.; Naegeli, D.; Shouse, K.; Smith, L.; Whitney, K. [Southwest Research Inst., San Antonio, TX (United States)

    1995-02-01

    The objective of this 3.5 year project is to develop a commercially competitive vehicle powered by ethanol (or ethanol blend) that can meet California`s ultra-low emission vehicle (ULEV) standards and equivalent corporate average fuel economy (CAFE) energy efficiency for a light-duty passenger car application. The definition of commercially competitive is independent of fuel cost, but does include technical requirements for competitive power, performance, refueling times, vehicle range, driveability, fuel handling safety, and overall emissions performance. This report summarizes a system design study completed after six months of effort on this project. The design study resulted in recommendations for ethanol-fuel blends that shall be tested for engine low-temperature cold-start performance and other criteria. The study also describes three changes to the engine, and two other changes to the vehicle to improve low-temperature starting, efficiency, and emissions. The three engine changes are to increase the compression ratio, to replace the standard fuel injectors with fine spray injectors, and to replace the powertrain controller. The two other vehicle changes involve the fuel tank and the aftertreatment system. The fuel tank will likely need to be replaced to reduce evaporative emissions. In addition to changes in the main catalyst, supplemental aftertreatment systems will be analyzed to reduce emissions before the main catalyst reaches operating temperature.

  11. Measurement of Ultra Low Outgassing Rates for NLC UHV Vacuum Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Kishiyama, K; Shen, S; Behne, D; Corlett, J N; Atkinson, D; Kennedy, K; Miller, T; Eriksson, L; Ross, M

    2001-06-12

    Ultra low outgassing rates would be highly advantageous in accelerators and storage rings, such as the Next Linear Collider (NLC), where an outgassing rate of <10{sup -12} Torr liter/sec/cm{sup 2} could eliminate the need for costly distributed pumping. Measuring such low outgassing rates at room temperature has many difficulties. However, by inspection of Fick's law, it can be seen that thermal desorption is proportional to outgassing rate. It is commonly observed that the outgas rate doubles approximately every 15 C for temperatures under 100 C. By measuring outgassing rate versus temperature and time and extrapolating back to room temperature we can measure outgassing rates that would otherwise be difficult to make. To produce a reliable measurement also requires the total surface area under study to be approximately an order of magnitude greater than the area of the measurement chamber walls. To accomplish this, 27 plates of 5083 aluminum were placed in the measurement chamber. This technique will be the basis for future investigation of outgassing rates of other sample plates fabricated with different machining and cleaning techniques.

  12. The ultra low frequency electromagnetic radiation observed in the topside ionosphere above boundaries of tectonic plates

    Directory of Open Access Journals (Sweden)

    Michael A. Athanasiou

    2015-01-01

    Full Text Available In this paper we present results of a comparison between ultra low frequency (ULF electromagnetic (EM radiation, recorded by an electric field instrument onboard the satellite detection of electromagnetic emissions transmitted from earthquake regions in the topside ionosphere, and the seismicity of regions with high and low seismic activity. In particular, we evaluated the energy variations of the ULF Ezelectric field component during a period of four years (2006-2009, in order to examine the possible relation of ULF EM radiation with seismogenic regions located in Central America, Indonesia, the Eastern Mediterranean Basin and Greece. As a tool for evaluating the ULF Ez energy variations we used singular spectrum analysis techniques. The results of our analysis clearly show a significant increase of the ULF EM energy emitted from regions of highest seismic activity at the boundaries tectonic plates. Furthermore, we found that higher electromagnetic radiation was detected in a region above the northern- western Greek Arc (R1 than above the adjacent region including Athens and its urban area. We interpret these results of the present study as suggesting that: i the seismogenic regions at the boundary of tectonic plates radiate ULF EM emissions observed by satellites in the topside ionosphere; and ii that this EM radiation is not only related with the occurrence time of great (M≥5 earthquakes, but it is often present in intermediate times and it appears as a quasi-permanent phenomenon.

  13. An ultra-low-voltage electronic implementation of inertial neuron model with nonmonotonous Liao's activation function.

    Science.gov (United States)

    Kant, Nasir Ali; Dar, Mohamad Rafiq; Khanday, Farooq Ahmad

    2015-01-01

    The output of every neuron in neural network is specified by the employed activation function (AF) and therefore forms the heart of neural networks. As far as the design of artificial neural networks (ANNs) is concerned, hardware approach is preferred over software one because it promises the full utilization of the application potential of ANNs. Therefore, besides some arithmetic blocks, designing AF in hardware is the most important for designing ANN. While attempting to design the AF in hardware, the designs should be compatible with the modern Very Large Scale Integration (VLSI) design techniques. In this regard, the implemented designs should: only be in Metal Oxide Semiconductor (MOS) technology in order to be compatible with the digital designs, provide electronic tunability feature, and be able to operate at ultra-low voltage. Companding is one of the promising circuit design techniques for achieving these goals. In this paper, 0.5 V design of Liao's AF using sinh-domain technique is introduced. Furthermore, the function is tested by implementing inertial neuron model. The performance of the AF and inertial neuron model have been evaluated through simulation results, using the PSPICE software with the MOS transistor models provided by the 0.18-μm Taiwan Semiconductor Manufacturer Complementary Metal Oxide Semiconductor (TSM CMOS) process.

  14. Friction moment analysis of space gyroscope bearing with ribbon cage under ultra-low oscillatory motion

    Institute of Scientific and Technical Information of China (English)

    Jiang Shaona; Chen Xiaoyang; Gu Jiaming; Shen Xuejin

    2014-01-01

    This paper presents the model of calculating the total friction moment of space gyro-scope ball bearings which usually work under ultra-low oscillatory motion and are very sensitive to the friction moment. The aim is to know the proportion of the friction moment caused by each frictional source in the bearing’s total friction moment, which is helpful to optimize the bearing design to deduce the friction moment. In the model, the cage dynamic equations considering six degree-of-freedom and the balls dynamic equations considering two degree-of-freedom were solved. The good trends with different loads between the measured friction moments and computational results prove that the model under constant rate was validated. The computational results show that when the speed was set at 5 r/min, the bearing’s maximum total friction moment when oscillation occurred was obviously larger than that occurred at a constant rate. At the onset of each oscillatory motion, the proportion of the friction moment caused by cage in the bearing’s total friction moment was very high, and it increased with the increasing speed. The analyses of different cage thicknesses and different clearances between cage pocket and ball show that smaller thickness and clearance were preferred.

  15. Novel Fe-based amorphous magnetic powder cores with ultra-low core losses

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Amorphous magnetic alloy powders were prepared from bulk metallic glasses Fe74Cr2Mo2Sn2P10Si4B4C2 with supercooled liq-uid region of 32 K by water atomization.Amorphous magnetic powder core precursor was produced from a mixture of the amorphous alloy powder with addition of insulation and bonding materials by mold compacting at room temperature.After annealing the core precursor,the amorphous magnetic core exhibits superior magnetic properties as compared with molypermalloy powder core.The initial permeability up to 1 MHz was about 80,the flux density at 300 Oe was 1.06 T and the core loss at 100 kHz for Bm=0.1 T was only 329 kW/m3.The ultra-low core loss is attributed to the combination of relatively high resistivity and the amorphous structure of the Fe-based amorphous powder.Besides the outstanding magnetic properties,the Fe-based amorphous magnetic powder core had a much lower cost which renders the powder cores a potential candidate for a variety of industrial applications.

  16. Advanced manufacturing technologies of large martensitic stainless steel castings with ultra low carbon and high cleanliness

    Directory of Open Access Journals (Sweden)

    Lou Yanchun

    2010-11-01

    Full Text Available The key manufacturing technologies associated with composition, microstructure, mechanical properties, casting quality and key process control for large martensitic stainless steel castings are involved in this paper. The achievements fully satisfied the technical requirements of the large 700 MW stainless steel hydraulic turbine runner for the Three Gorges Hydropower Station, and become the major technical support for the design and manufacture of the largest 700 MW hydraulic turbine generator unit in the world developed through our own efforts. The characteristics of a new high yield to tensile strength (Rp0.2/Rm ratio and high obdurability martensitic stainless steel with ultra low carbon and high cleanliness are also described. Over the next ten years, the large martensitic stainless steel castings and advanced manufacturing technologies will see a huge demand in clean energy industry such as nuclear power, hydraulic power at home and abroad. Therefore, the new high yield o tensile strength (Rp0.2/Rm ratio and high obdurability martensitic stainless steel materials, the fast and flexible manufacturing technologies of large size castings, and new environment friendly sustainable process will face new challenges and opportunities.

  17. Possible operation of the European XFEL with ultra-low emittance beams

    CERN Document Server

    Brinkmann, R; Yurkov, M V

    2010-01-01

    Recent successful lasing of the Linac Coherent Light Source (LCLS) in the hard x-ray regime and the experimental demonstration of a possibility to produce low-charge bunches with ultra-small normalized emittance have lead to the discussions on optimistic scenarios of operation of the European XFEL. In this paper we consider new options that make use of low-emittance beams, a relatively high beam energy, tunable-gap undulators, and a multi-bunch capability of this facility. We study the possibility of operation of a spontaneous radiator (combining two of them, U1 and U2, in one beamline) in the SASE mode in the designed photon energy range 20-90 keV and show that it becomes possible with ultra-low emittance electron beams similar to those generated in LCLS. As an additional attractive option we consider the generation of powerful soft x-ray and VUV radiation by the same electron bunch for pump-probe experiments, making use of recently invented compact afterburner scheme. We also propose a betatron switcher as ...

  18. An ultra-low noise optical head for liquid environment atomic force microscopy

    Science.gov (United States)

    Schlesinger, I.; Kuchuk, K.; Sivan, U.

    2015-08-01

    The design considerations and eventual performance of a new, ultra-low noise optical head for dynamic atomic force microscopy (AFM) are presented. The head, designed specifically for the study of hydration layers and ion organization next to solid surfaces and biomolecules, displays an integrated tip-sample distance noise below 3 pm. The sensitivity of the optical beam deflection sensor, operating at frequencies up to 8.6 MHz (3 dB roll-off), is typically below 10 fm / √{ Hz } , enabling utilization of high frequency cantilevers of low thermal noise for fundamental and higher mode imaging. Exceptional signal stability and low optical noise are achieved by replacing the commonly used laser diode with a helium-neon laser. An integral photothermal excitation of the cantilever produces pure harmonic oscillations, minimizing the generation of higher cantilever modes and deleterious sound waves characterizing the commonly used excitation by a piezoelectric crystal. The optical head is designed to fit on top of the widespread Multimode® (Bruker) piezo-tube and accommodate its commercial liquid cell. The performance of the new AFM head is demonstrated by atomic resolution imaging of a muscovite mica surface in aqueous solution.

  19. Ultra-low percolation threshold in ferrite-metal cofired ceramics brings both high permeability and high permittivity.

    Science.gov (United States)

    Wang, Liang; Bai, Yang; Lu, Xuefei; Cao, Jiang-Li; Qiao, Li-Jie

    2015-01-05

    High permeability and high permittivity are hard to be achieved simultaneously, either in single-phased materials or in composite materials, such as ferrite-ferroelectric ceramic composites and ferrite-metal percolative composites. In this work, ultra-low percolation threshold is achieved in NiZnCu ferrite-Ag cofired ceramics, which endows the composite with both high permeability and high permittivity by minimizing the negative effect of nonmagnetic conductive fillers on magnetic properties. The percolation threshold is controlled by the temperature matching between ferrite densification and Ag melting. A thin and long percolative net forms between large ferrite grains under a proper cofiring process, which brings a low percolation threshold of 1.21vol%, more than one order of magnitude lower than the theoretical value of 16vol%. Near the ultra-low threshold, the composite exhibits a high permeability of 585 and a high permittivity of 78.

  20. Ultra-low-dose recombinant human bone morphogenetic protein-2 for 3-level anterior cervical diskectomy and fusion.

    Science.gov (United States)

    Pourtaheri, Sina; Hwang, Ki; Faloon, Michael; Issa, Kimona; Mease, Samuel J; Mangels, Daniel; Sinha, Kumar; Emami, Arash

    2015-04-01

    This study evaluated the safety of 3-level anterior cervical diskectomy and fusion (ACDF) with ultra-low-dose recombinant bone morphogenetic protein-2 (rhBMP-2). Thirty-seven consecutive patients with cervical spondylotic myelopathy who were treated with 3-level ACDF and rhBMP-2 were evaluated. Complications such as airway or cervical swelling or hematoma were not observed. The rate of dysphagia was no different at 1, 2, and 6 months postoperatively compared with reports in the literature without rhBMP-2. There were significant improvements in VAS neck/arm pain, Oswestry Neck Disability Index, and cervical lordosis. The use of ultra-low-dose rhBMP-2 for 3-level ACDF may be efficacious for surgically addressing 3-level spondylotic myelopathy.

  1. Ground-water monitoring compliance projects for Hanford Site Facilities: Progress report for the period April 1--June 30, 1988: Volume 1, Text

    Energy Technology Data Exchange (ETDEWEB)

    1988-09-01

    This is Volume 1 of a two-volume set of documents that describes the progress of 10 Hanford Site ground-water monitoring projects for the period April 1 to June 30, 1988. This volume discusses the projects; Volume 2 provides as-built diagrams, drilling logs, and geophysical logs for wells drilled during this period in the 100-N Area and near the 216-A-36B Crib.

  2. Population Evolution of Oxide Inclusions in Ti-stabilized Ultra-low Carbon Steels after Deoxidation

    Institute of Scientific and Technical Information of China (English)

    Wen YANG; Ying ZHANG; Li-feng ZHANG; Hao-jian DUAN; Li WANG

    2015-01-01

    Population density function (PDF),which can eliminate the arbitrariness caused by the choice of the num-ber and the size of bins compared to the well-used histograms,was introduced to analyze the amount of inclusions. The population evolution of oxide inclusions in forms of PDF in Ti-stabilized ultra-low carbon steels after deoxidation during industrial RH refining and continuous casting processes was analyzed using an automated SEM-EDS system. It was found that after deoxidation till the early stage of casting,the alumina inclusions exhibited a lognormal PDF distribution,and three factors including the existence of a large amount of alumina clusters,the generation of alumi-na from the reduction of Al-Ti-O inclusions and the reoxidation of molten steel were estimated as the reasons.The shape parameterσwas high after deoxidation and then decreased after Ti treatment,indicating that in a short period after deoxidation,the size of alumina inclusions was widely distributed.After Ti treatment,the distribution of inclu-sion size was more concentrated.The scale parameter m decreased with time during the whole refining process,indi-cating that the proportion of large inclusions decreased during refining.Contrarily,the Al-Ti-O inclusions presented a fractal PDF distribution except at the end of casting with fractal dimension D of 4.3,and the constant of propor-tionality C decreased with time during RH refining and increased during casting process.The reoxidation of steel by slag entrapped from ladle was considered as the reason for the lognormal PDF behavior of Al-Ti-O inclusions at the end of casting.

  3. High-Resolution Dual-Comb Spectroscopy with Ultra-Low Noise Frequency Combs

    Science.gov (United States)

    Hänsel, Wolfgang; Giunta, Michele; Beha, Katja; Perry, Adam J.; Holzwarth, R.

    2017-06-01

    Dual-comb spectroscopy is a powerful tool for fast broad-band spectroscopy due to the parallel interrogation of thousands of spectral lines. Here we report on the spectroscopic analysis of acetylene vapor in a pressurized gas cell using two ultra-low noise frequency combs with a repetition rate around 250 MHz. Optical referencing to a high-finesse cavity yields a sub-Hertz stability of all individual comb lines (including the virtual comb lines between 0 Hz and the carrier) and permits one to pick a small difference of repetition rate for the two frequency combs on the order of 300 Hz, thus representing an optical spectrum of 100 THz (˜3300 \\wn) within half the free spectral range (125 MHz). The transmission signal is derived straight from a photodetector and recorded with a high-resolution spectrum analyzer or digitized with a computer-controlled AD converter. The figure to the right shows a schematic of the experimental setup which is all fiber-coupled with polarization-maintaining fiber except for the spectroscopic cell. The graph on the lower right reveals a portion of the recorded radio-frequency spectrum which has been scaled to the optical domain. The location of the measured absorption coincides well with data taken from the HITRAN data base. Due to the intrinsic linewidth of all contributing comb lines, each sampling point in the transmission graph corresponds to the probing at an optical frequency with sub-Hertz resolution. This resolution is maintained in coherent wavelength conversion processes such as difference-frequency generation (DFG), sum-frequency generation (SFG) or non-linear broadening (self-phase modulation), and is therefore easily transferred to a wide spectral range from the mid infrared up to the visible spectrum.

  4. Characterization of ultra low frequency (ULF pulsations and the investigation of their possible source

    Directory of Open Access Journals (Sweden)

    S. H. Mthembu

    2009-08-01

    Full Text Available In this paper we present the results from the observation of ultra low frequency (ULF pulsations in the Doppler velocity data from SuperDARN HF radar located at Goose Bay (61.94° N, 23.02° E, geomagnetic. Fourier spectral techniques were used to determine the spectral content of the data and the results show Pc 5 ULF pulsations (with a frequency range of 1 to 4 mHz where the magnetic field lines were oscillating at discrete frequencies of about 1.3 and 1.9 mHz. These pulsations are classified as field lines resonance (FLR since the 1.9 mHz component exhibited an enhancement in amplitude with an associated phase change of approximately 180° across a resonance latitude of 71.3°. The spatial and temporal structure of the ULF pulsations was examined by investigating their instantaneous amplitude which was calculated as the amplitude of the analytic signal. The results presented a full field of view which exhibit pulsations activity simultaneously from all beams. This representation shows that the peak amplitude of the 1.9 mHz component was observed over the longitudinal range of 13°. The temporal structure of the pulsations was investigated from the evolution of the 1.9 mHz component and the results showed that the ULF pulsations had a duration of about 1 h. Wavelet analysis was used to investigate solar wind as a probable source of the observed ULF pulsations. The time delay compared well with the solar wind travel time estimates and the results suggest a possible link between the solar wind and the observed pulsations. The sudden change in dynamic pressure also proved to be a possible source of the observed ULF pulsations.

  5. Construction and Evaluation of an Ultra Low Latency Frameless Renderer for VR.

    Science.gov (United States)

    Friston, Sebastian; Steed, Anthony; Tilbury, Simon; Gaydadjiev, Georgi

    2016-04-01

    Latency - the delay between a user's action and the response to this action - is known to be detrimental to virtual reality. Latency is typically considered to be a discrete value characterising a delay, constant in time and space - but this characterisation is incomplete. Latency changes across the display during scan-out, and how it does so is dependent on the rendering approach used. In this study, we present an ultra-low latency real-time ray-casting renderer for virtual reality, implemented on an FPGA. Our renderer has a latency of ~1 ms from 'tracker to pixel'. Its frameless nature means that the region of the display with the lowest latency immediately follows the scan-beam. This is in contrast to frame-based systems such as those using typical GPUs, for which the latency increases as scan-out proceeds. Using a series of high and low speed videos of our system in use, we confirm its latency of ~1 ms. We examine how the renderer performs when driving a traditional sequential scan-out display on a readily available HMO, the Oculus Rift OK2. We contrast this with an equivalent apparatus built using a GPU. Using captured human head motion and a set of image quality measures, we assess the ability of these systems to faithfully recreate the stimuli of an ideal virtual reality system - one with a zero latency tracker, renderer and display running at 1 kHz. Finally, we examine the results of these quality measures, and how each rendering approach is affected by velocity of movement and display persistence. We find that our system, with a lower average latency, can more faithfully draw what the ideal virtual reality system would. Further, we find that with low display persistence, the sensitivity to velocity of both systems is lowered, but that it is much lower for ours.

  6. Characterization of a novel ultra low refractive index material for biosensor application.

    Science.gov (United States)

    Memisevic, Jasenka; Korampally, Venumadhav; Gangopadhyay, Shubhra; Grant, Sheila A

    2009-08-18

    Nanoporous materials can provide significant benefits to the field of biosensors. Their size and porous structure makes them an ideal tool for improving sensor performance. This study characterized a novel ultra low index of refraction nanoporous organosilicate (NPO) material for use as an optical platform for fluorescence-based optical biosensors. While serving as the low index cladding material, the novel coating based on organosilicate nanoparticles also provides an opportunity for a high surface area coating that can be utilized for immobilizing biological probes. Biological molecules were immobilized onto NPO, which was spin-coated on silicon and glass substrates. The biological molecule was composed of Protein A conjugated to AlexaFluor 546 fluorophore and then immobilized onto the NPO substrate via silanization. Sample analysis consisted of spectrofluorometry, FT-IR spectroscopy, scanning electron microscopy, contact angle measurement and ellipsometry. The results showed the presence of emission peaks at 574 nm, indicating that the immobilization of Protein A to the NPO material is possible. When compared to Si and glass substrates not coated with NPO, the results showed a 100X and 10X increase in packing density with the NPO coated films respectively. Ellipsometric analysis, FT-IR, contact angle, and SEM imaging of the surface immobilized NPO films suggested that while the surface modifications did induce some damage, it did not incur significant changes to its unique characteristics, i.e., pore structure, wettability and index of refraction. It was concluded that NPO films would be a viable sensor substrate to enhance sensitivity and improve sensor performance.

  7. Prevention of burn-on defect on surface of hydroturbine blade casting of ultra-low-carbon refining stainless steel

    Directory of Open Access Journals (Sweden)

    Li Ling

    2008-08-01

    Full Text Available The burn-on sand is common surface defect encountered in CO2-cured silicate-bonded sand casting of hydroturbine blade of ultra-low-carbon martensitic stainless steel, its feature, causes and prevention measures are presented in this paper. Experiments showed that the burn-on defect is caused by oxidization of chromium in the molten steel at high temperature and can be effectively eliminated by using chromium-corundum coating.

  8. Prevention of burn-on defect on surface of hydroturbine blade casting of ultra-low-carbon refining stainless steel

    Institute of Scientific and Technical Information of China (English)

    Li Ling; Xie Huasheng; Huang Danzhong; Li Hankun; Tan Rui; Zhou Jingyi

    2008-01-01

    The burn-on sand is common surface defect encountered in CO2-cured silicate-bonded sand casting of hydroturbine blade of ultra-low-carbon martensitic stainless steel, its feature, causes and prevention measures are presented in this paper. Experiments showed that the bum-on defect is caused by oxidization of chromium in the molten steel at high temperature and can be effectively eliminated by using chromium-corundum coating.

  9. Ultra-low phase noise 10 GHz oscillator to pump the parametric transducers of the Mario Schenberg gravitational wave detector

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Luiz A [Divisao de Materiais, Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP 12201-970 (Brazil); Costa, Cesar A [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Aguiar, Odylio D [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Frajuca, Carlos [Centro Federal de Educacao Tecnologica de Sao Paulo, Rua Pedro Vicente 625, SP 01109-010 (Brazil); Mosso, Marbey M [CETUC, Centro de Estudos em Telecomunicacoes, PUC-RJ, Rio de Janeiro, RJ (Brazil); Podcameni, Abelardo [CETUC, Centro de Estudos em Telecomunicacoes, PUC-RJ, Rio de Janeiro, RJ (Brazil); Silva, Henrique J P P da [CETUC, Centro de Estudos em Telecomunicacoes, PUC-RJ, Rio de Janeiro, RJ (Brazil); Magalhaes, Nadja S [Instituto Tecnologica de Aeronautica, Departamento de FIsica, Praca Marechal Eduardo Gomes, 50, Sao Jose dos Campos, SP 12228-900 (Brazil)

    2004-03-07

    We developed a 10 GHz feedback oscillator with ultra-low phase noise. The oscillator was constructed to operate as the pump for the parametric transducers of the Mario Schenberg gravitational wave detector. We calculated the performance of the detector with this pump oscillator and determined how much improvement in phase noise would be necessary in order to reach the standard quantum limit in sensitivity.

  10. Single-mode optical fiber design with wide-band ultra low bending-loss for FTTH application.

    Science.gov (United States)

    Watekar, Pramod R; Ju, Seongmin; Han, Won-Taek

    2008-01-21

    We propose a new design of a single-mode optical fiber (SMF) which exhibits ultra low bend sensitivity over a wide communication band (1.3 microm to 1.65 microm). A five-cladding fiber structure has been proposed to minimize the bending loss, estimated to be as low as 4.4x10(-10) dB/turn for the bend radius of 10 mm.

  11. Noise Reduction Effect of Multiple-Sampling-Based Signal-Readout Circuits for Ultra-Low Noise CMOS Image Sensors

    OpenAIRE

    Shoji Kawahito; Min-Woong Seo

    2016-01-01

    This paper discusses the noise reduction effect of multiple-sampling-based signal readout circuits for implementing ultra-low-noise image sensors. The correlated multiple sampling (CMS) technique has recently become an important technology for high-gain column readout circuits in low-noise CMOS image sensors (CISs). This paper reveals how the column CMS circuits, together with a pixel having a high-conversion-gain charge detector and low-noise transistor, realizes deep sub-electron read noise...

  12. Ground volume assessment using 'Structure from Motion' photogrammetry with a smartphone and a compact camera

    Science.gov (United States)

    Wróżyński, Rafał; Pyszny, Krzysztof; Sojka, Mariusz; Przybyła, Czesław; Murat-Błażejewska, Sadżide

    2017-06-01

    The article describes how the Structure-from-Motion (SfM) method can be used to calculate the volume of anthropogenic microtopography. In the proposed workflow, data is obtained using mass-market devices such as a compact camera (Canon G9) and a smartphone (iPhone5). The volume is computed using free open source software (VisualSFMv0.5.23, CMPMVSv0.6.0., MeshLab) on a PCclass computer. The input data is acquired from video frames. To verify the method laboratory tests on the embankment of a known volume has been carried out. Models of the test embankment were built using two independent measurements made with those two devices. No significant differences were found between the models in a comparative analysis. The volumes of the models differed from the actual volume just by 0.7‰ and 2‰. After a successful laboratory verification, field measurements were carried out in the same way. While building the model from the data acquired with a smartphone, it was observed that a series of frames, approximately 14% of all the frames, was rejected. The missing frames caused the point cloud to be less dense in the place where they had been rejected. This affected the model's volume differed from the volume acquired with a camera by 7%. In order to improve the homogeneity, the frame extraction frequency was increased in the place where frames have been previously missing. A uniform model was thereby obtained with point cloud density evenly distributed. There was a 1.5% difference between the embankment's volume and the volume calculated from the camera-recorded video. The presented method permits the number of input frames to be increased and the model's accuracy to be enhanced without making an additional measurement, which may not be possible in the case of temporary features.

  13. Early Site Permit Demonstration Program: Guidelines for determining design basis ground motions. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-03-18

    This report develops and applies a methodology for estimating strong earthquake ground motion. The motivation was to develop a much needed tool for use in developing the seismic requirements for structural designs. An earthquake`s ground motion is a function of the earthquake`s magnitude, and the physical properties of the earth through which the seismic waves travel from the earthquake fault to the site of interest. The emphasis of this study is on ground motion estimation in Eastern North America (east of the Rocky Mountains), with particular emphasis on the Eastern United States and southeastern Canada. Eastern North America is a stable continental region, having sparse earthquake activity with rare occurrences of large earthquakes. While large earthquakes are of interest for assessing seismic hazard, little data exists from the region to empirically quantify their effects. Therefore, empirically based approaches that are used for other regions, such as Western North America, are not appropriate for Eastern North America. Moreover, recent advances in science and technology have now made it possible to combine theoretical and empirical methods to develop new procedures and models for estimating ground motion. The focus of the report is on the attributes of ground motion in Eastern North America that are of interest for the design of facilities such as nuclear power plants. Specifically considered are magnitudes M from 5 to 8, distances from 0 to 500 km, and frequencies from 1 to 35 Hz.

  14. Ultra-low-density genotype panels for breed assignment of Angus and Hereford cattle.

    Science.gov (United States)

    Judge, M M; Kelleher, M M; Kearney, J F; Sleator, R D; Berry, D P

    2017-06-01

    Angus and Hereford beef is marketed internationally for apparent superior meat quality attributes; DNA-based breed authenticity could be a useful instrument to ensure consumer confidence on premium meat products. The objective of this study was to develop an ultra-low-density genotype panel to accurately quantify the Angus and Hereford breed proportion in biological samples. Medium-density genotypes (13 306 single nucleotide polymorphisms (SNPs)) were available on 54 703 commercial and 4042 purebred animals. The breed proportion of the commercial animals was generated from the medium-density genotypes and this estimate was regarded as the gold-standard breed composition. Ten genotype panels (100 to 1000 SNPs) were developed from the medium-density genotypes; five methods were used to identify the most informative SNPs and these included the Delta statistic, the fixation (F st) statistic and an index of both. Breed assignment analyses were undertaken for each breed, panel density and SNP selection method separately with a programme to infer population structure using the entire 13 306 SNP panel (representing the gold-standard measure). Breed assignment was undertaken for all commercial animals (n=54 703), animals deemed to contain some proportion of Angus based on pedigree (n=5740) and animals deemed to contain some proportion of Hereford based on pedigree (n=5187). The predicted breed proportion of all animals from the lower density panels was then compared with the gold-standard breed prediction. Panel density, SNP selection method and breed all had a significant effect on the correlation of predicted and actual breed proportion. Regardless of breed, the Index method of SNP selection numerically (but not significantly) outperformed all other selection methods in accuracy (i.e. correlation and root mean square of prediction) when panel density was ⩾300 SNPs. The correlation between actual and predicted breed proportion increased as panel density increased. Using

  15. Accuracy design of ultra-low residual reflection coatings for laser optics

    Science.gov (United States)

    Liu, Huasong; Yang, Xiao; Wang, Lishuan; Jiao, Hongfei; Ji, Yiqin; Zhang, Feng; Liu, Dandan; Jiang, Chenghui; Jiang, Yugang; Chen, Deying

    2017-06-01

    Refractive index inhomogeneity is one of the important characteristics of optical coating material, which is one of the key factors to produce loss to the ultra-low residual reflection coatings except using the refractive index inhomogeneity to obtain gradient-index coating. In the normal structure of antireflection coatings for center wavelength at 532 nm, the physical thicknesses of layer H and layer L are 22.18 nm and 118.86 nm, respectively. The residual reflectance caused by refractive index inhomogeneity (the degree of inhomogeneous is between -0.2 and 0.2) is about 200 ppm, and the minimum reflectivity wavelength is between 528.2 nm and 535.2 nm. A new numerical method adding the refractive index inhomogeneity to the spectra calculation was proposed to design the laser antireflection coatings, which can achieve the design of antireflection coatings with ppm residual reflection by adjusting physical thickness of the couple layers. When the degree of refractive index inhomogeneity of the layer H and layer L is -0.08 and 0.05 respectively, the residual reflectance increase from zero to 0.0769% at 532 nm. According to the above accuracy numerical method, if layer H physical thickness increases by 1.30 nm and layer L decrease by 4.50 nm, residual reflectance of thin film will achieve to 2.06 ppm. When the degree of refractive index inhomogeneity of the layer H and layer L is 0.08 and -0.05 respectively, the residual reflectance increase from zero to 0.0784% at 532 nm. The residual reflectance of designed thin film can be reduced to 0.8 ppm by decreasing the layer H of 1.55 nm while increasing the layer L of 4.94 nm. Project supported by the National Natural Science Foundation of China (Grant Nos. 61405145 and 61235011), the Natural Science Foundation of Tianjin, China (Grant No. 15JCZDJC31900), and the China Postdoctoral Science Foundation (Grant Nos. 2015T80115 and 2014M560104).

  16. Back End of Line Nanorelays for Ultra-low Power Monolithic Integrated NEMS-CMOS Circuits

    KAUST Repository

    Lechuga Aranda, Jesus Javier

    2016-05-01

    Since the introduction of Complementary-Metal-Oxide-Semiconductor (CMOS) technology, the chip industry has enjoyed many benefits of transistor feature size scaling, including higher speed and device density and improved energy efficiency. However, in the recent years, the IC designers have encountered a few roadblocks, namely reaching the physical limits of scaling and also increased device leakage which has resulted in a slow-down of supply voltage and power density scaling. Therefore, there has been an extensive hunt for alternative circuit architectures and switching devices that can alleviate or eliminate the current crisis in the semiconductor industry. The Nano-Electro-Mechanical (NEM) relay is a promising alternative switch that offers zero leakage and abrupt turn-on behaviour. Even though these devices are intrinsically slower than CMOS transistors, new circuit design techniques tailored for the electromechanical properties of such devices can be leveraged to design medium performance, ultra-low power integrated circuits. In this thesis, we deal with a new generation of such devices that is built in the back end of line (BEOL) CMOS process and is an ideal option for full integration with current CMOS transistor technology. Simulation and verification at the circuit and system level is a critical step in the design flow of microelectronic circuits, and this is especially important for new technologies that lack the standard design infrastructure and well-known verification platforms. Although most of the physical and electrical properties of NEM structures can be simulated using standard electronic automation software, there is no report of a reliable behavioural model for NEMS switches that enable large circuit simulations. In this work, we present an optimised model of a BEOL nano relay that encompasses all the electromechanical characteristics of the device and is robust and lightweight enough for VLSI applications that require simulation of thousands of

  17. Investigation on Nonmetallic Inclusions in Ultra-Low-Oxygen Special Steels

    Science.gov (United States)

    Li, Jin Zhu; Jiang, Min; He, Xiao-Fei; Sun, Wei; Wang, Xin-Hua

    2016-08-01

    Investigation was carried out on inclusions in ultra-low-oxygen special steel by taking systematic samplings not only from secondary refining but also from continuous casting. It was found that RH degassing had a much stronger ability than LF refining in removing inclusions. Total oxygen (TO) can be further reduced from 0.0013 to 0.0015 mass pct to about 0.00047 mass pct without too much difficulty by elongating RH degassing time to 33 minute. Inclusions larger than 5 μm were decreased from 1.49 to 0.08 N/mm2 with a removal ratio of about 94 pct. During secondary refining, inclusions experienced continuous evolution from Al2O3 to the MgO-Al2O3, CaO-MgO-Al2O3, and CaO-Al2O3 system due to complex reactions among slag, steel, and refractory materials. Because of more efficient removal of solid inclusions, especially those large ones during RH treatment, thorough modification of solid inclusions into liquid CaO-MgO-Al2O3 can be achieved. Reoxidation during casting resulted in an obvious rise in Al2O3 content in inclusions, which offset the efforts made during secondary refining. Liquid CaO-Al2O3 systems after RH were changed to solid CaO-Al2O3, MgO-Al2O3, or CaO-MgO-Al2O3 again. Large inclusions with sizes approaching several hundred micron were frequently observed in casting bloom by a vast area of scanning under an automatic scanning electron microscope despite very low TO of about 0.00059 mass pct. A total of 78 pct of them were cluster-shaped CaO-MgO-Al2O3 solid inclusions with sizes as large as 200-330 μm. Most clusters over 100 μm were constituted by smaller particles with similar chemical compositions to other small singular inclusions in steel, which indicated that they were formed due to the aggregations of small inclusions during casting. Moreover, the location of them indicated a close relationship to the solidification microstructure of steel, which has not been covered before. It was impressively found that larger inclusions were mainly in the column

  18. Estimation of Cosmic Induced Contamination in Ultra-low Background Detector Materials

    Energy Technology Data Exchange (ETDEWEB)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Berguson, Timothy J.; Greene, Austen T.

    2012-08-01

    Executive Summary This document presents the result of investigating a way to reliably determine cosmic induced backgrounds for ultra-low background materials. In particular, it focuses on those radioisotopes produced by the interactions with cosmic ray particles in the detector materials that act as a background for experiments looking for neutrinoless double beta decay. This investigation is motivated by the desire to determine background contributions from cosmic ray activation of the electroformed copper that is being used in the construction of the MAJORANA DEMONSTRATOR. The most important radioisotope produced in copper that contributes to the background budget is 60Co, which has the potential to deposit energy in the region of interest of this experiment. Cobalt-60 is produced via cosmic ray neutron collisions in the copper. This investigation aims to provide a method for determining whether or not the copper has been exposed to cosmic radiation beyond the threshold which the Majorana Project has established as the maximum exposure. This threshold is set by the Project as the expected contribution of this source of background to the overall background budget. One way to estimate cosmic ray neutron exposure of materials on the surface of the Earth is to relate it to the cosmic ray muon exposure. Muons are minimum-ionizing particles and the available technologies to detect muons are easier to implement than those to detect neutrons. We present the results of using a portable, ruggedized muon detector, the µ-Witness made by our research group, for determination of muon exposure of materials for the MAJORANA DEMONSTRATOR. From the muon flux measurement, this report presents a method to estimate equivalent sea-level exposure, and then infer the neutron exposure of the tracked material and thus the cosmogenic activation of the copper. This report combines measurements of the muon flux taken by the µ-Witness detector with Geant4 simulations in order to assure our

  19. Isotope Brayton ground demonstration testing and flight qualification program. Volume 1. Technical program

    Energy Technology Data Exchange (ETDEWEB)

    1974-12-09

    A proposal for the demonstration, development and production of the Isotope Brayton Flight System for space vehicles is presented with details on the technical requirements for designing and testing a ground demonstration system and on the program organization and personnel. (LCL)

  20. First results of a simultaneous measurement of tritium and 14C in an ultra-low-background proportional counter for environmental sources of methane

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Emily K.; Aalseth, Craig E.; Day, Anthony R.; Hoppe, Eric W.; Keillor, Martin E.; Moran, James J.; Panisko, Mark E.; Seifert, Allen; Tatishvili, Gocha; Williams, Richard M.

    2016-02-01

    Abstract Simultaneous measurement of tritium and 14C would provide an added tool for tracing organic compounds through environmental systems and is possible via beta energy spectroscopy of sample-derived methane in internal-source gas proportional counters. Since the mid-1960’s atmospheric tritium and 14C have fallen dramatically as the isotopic injections from above-ground nuclear testing have been diluted into the ocean and biosphere. In this work, the feasibility of simultaneous tritium and 14C measurements via proportional counters is revisited in light of significant changes in both the atmospheric and biosphere isotopics and the development of new ultra-low-background gas proportional counting capabilities for small samples (roughly 50 cc methane). A Geant4 Monte Carlo model of a Pacific Northwest National Laboratory (PNNL) proportional counter response to tritium and 14C is used to analyze small samples of two different methane sources to illustrate the range of applicability of contemporary simultaneous measurements and their limitations. Because the two methane sources examined were not sample size limited, we could compare the small-sample measurements performed at PNNL with analysis of larger samples performed at a commercial laboratory. The dual-isotope simultaneous measurement is well matched for methane samples that are atmospheric or have an elevated source of tritium (i.e. landfill gas). For samples with low/modern tritium isotopics (rainwater), commercial separation and counting is a better fit.

  1. Results of ultra-low level 71ge counting for application in the Gallex-solar neutrino experiment at the Gran Sasso Underground Physics Laboratory

    Science.gov (United States)

    Hampel, W.; Heusser, G.; Huebner, M.; Kiko, J.; Kirsten, T.; Schneider, K.; Schlotz, R.

    1985-01-01

    It has been experimentally verified that the Ultra-Low-Level Counting System for the Gallex solar neutrino experiment is capable of measuring the expected solar up silon-flux to plus or minus 12% during two years of operation.

  2. Engineering Drawing Practices - Volume I of II: Aerospace and Ground Support Equipment

    Science.gov (United States)

    Schwindt, Paul A.

    2015-01-01

    This manual establishes the essential requirements and reference documents for the preparation and revision of digital product definition data sets prepared for or by NASA at KSC. This volume is only applicable to KSC in-house programs/projects. These requirements do not apply to the preparation of illustrations, artwork, or figures in technical publications.

  3. Resource Conservation and Recovery Act ground-water monitoring projects for Hanford Facilities: Progress report for the period July 1 to September 30, 1989 - Volume 1 - Text

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.M.; Bates, D.J.; Lundgren, R.E.

    1989-12-01

    This is Volume 1 of a two-volume document that describes the progress of 14 Hanford Site ground-water monitoring projects for the period July 1 to September 30, 1989. This volume discusses the projects; Volume 2 provides as-built diagrams, completion/inspection reports, drilling logs, and geophysical logs for wells drilled, completed, or logged during this period. Volume 2 can be found on microfiche in the back pocket of Volume 1. The work described in this document is conducted by the Pacific Northwest Laboratory under the management of Westinghouse Hanford Company for the US Department of Energy. Concentrations of ground-water constituents are compared to federal drinking water standards throughout this document for reference purposes. All drinking water supplied from the sampled aquifer meets regulatory standards for drinking water quality.

  4. Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 3: Ecological risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hlohowskyj, I.; Hayse, J.; Kuperman, R.; Van Lonkhuyzen, R.

    2000-02-25

    The Environmental Management Division of the U.S. Army Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation (RI) and feasibility study (FS) of the J-Field area at APG, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. As part of that activity, Argonne National Laboratory (ANL) conducted an ecological risk assessment (ERA) of the J-Field site. This report presents the results of that assessment.

  5. Structure Character of M-A Constituent in CGHAZ of New Ultra-Low Carbon Bainitic Steel under Laser Welding Conditions

    Institute of Scientific and Technical Information of China (English)

    Lin ZHAO; Wuzhu CHEN; Xudong ZHANG; Jiguo SHAN

    2006-01-01

    800 MPa grade new ultra-low carbon bainitic (NULCB) steel is the recently developed new generation steel.The microstructure in the coarse-grained heat-affected zone (CGHAZ) of NULCB steel under laser welding conditions was investigated by thermal simulation. The influence of the cooling time from 800℃ to 500℃,t8/5 (0.3~30 s), on the microstructure of the CGHAZ was discussed. The experimental results indicate that the microstructure of the CGHAZ is only the granular bainite which consists of bainitic ferrite (BF) lath and M-A constituent while t8/5 is 0.3~30 s. The M-A constituent consists of twinned martensite and residual austenite, and the change of the volume fraction of the residual austenite in the M-A constituent is very small when t8/5 is between 0.3 and 30 s. The morphology of the M-A constituent obviously changes with the variation of t8/5. As t8/5 increases, the average width, gross and shape parameter of the M-A constituent increase, while the line density of the M-A constituent decreases.

  6. A Physical Model to Study the Effects of Nozzle Design on Dense Two-Phase Flows in a Slab Mold Casting Ultra-Low Carbon Steels

    Science.gov (United States)

    Salazar-Campoy, María M.; Morales, R. D.; Nájera-Bastida, A.; Cedillo-Hernández, Valentín; Delgado-Pureco, J. C.

    2017-01-01

    Momentum transfer of argon-steel flows in a slab mold were studied through an air-water physical model and particle image velocimetry measurements under the effects of nozzle design (nozzles with square ports S, square ports with bottom design U and circular ports C) and gas flow rate. The ratio of drag momentum of the gas phase over the liquid phase defines the conditions for coupled (existence of momentum transfer between the phases) and channeled flows (defined as those conditions where there is not further momentum transfer between both phases). When the ratio of superficial velocities of the gas phase over the liquid phase in the nozzle bore is less than 0.14, the flow pattern in the mold is dependent on the nozzle design and flow rate of gas (2 to 10 L/minute). Above this magnitude, the flow pattern becomes uncoupled and independent from the nozzle design and from the flow rate of gas. The ratios of drag velocities of the gas phase on the liquid phase and their superficial velocities in the nozzle bore are strongly dependent on the volume fraction of the gas phase. Nozzle U delivers the smallest sizes of bubbles and the smaller amount of bubble swarms per unit time impacting on the narrow face of the mold. It is, therefore, the most recommendable to cast ultra-low carbon steels. Practical implications derived from these results are written down in the text.

  7. Ground Organic Monolith Particles Having a Large Volume of Macropores as Chromatographic Separation Media

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Wook; Ali, Faiz; Kim, Yune Sung; Cheong, Won Jo [Inha Univ., Incheon (Korea, Republic of)

    2014-07-15

    A reaction mixture was developed for formation of soft organic monolith that was easily smashed, rinsed, refluxed, filtered, and dried to give monolith particles having high pore volume of macropores. This phase was almost without mesopores. The reaction mixture was composed of methacrylic acid, ethylene glycol dimethacrylate, polyethylene glycol (porogen), and an initiator in a mixed solvent of toluene and isooctane. The selection of porogen and its amount was carefully carried out to obtain the optimized separation efficiency of the resultant phase. The median macropore size was 1.6 μm, and the total pore volume was 3.0-3.4 mL/g. The median particle size (volume based) was 15 μm, and the range of particle size distribution was very broad. Nevertheless the column (1 Χ 300 mm) packed with this phase showed good separation efficiency (N∼10,000-16,000) comparable to that of a commercial column packed with 5 μm C18 silica particles.

  8. Shuttle Ground Operations Efficiencies/Technologies Study (SGOE/T). Volume 5: Technical Information Sheets (TIS)

    Science.gov (United States)

    Scholz, A. L.; Hart, M. T.; Lowry, D. J.

    1987-01-01

    The Technology Information Sheet was assembled in database format during Phase I. This document was designed to provide a repository for information pertaining to 144 Operations and Maintenance Instructions (OMI) controlled operations in the Orbiter Processing Facility (OPF), Vehicle Assembly Building (VAB), and PAD. It provides a way to accumulate information about required crew sizes, operations task time duration (serial and/or parallel), special Ground Support Equipment (GSE). required, and identification of a potential application of existing technology or the need for the development of a new technolgoy item.

  9. Ultra-low-loss CMOS-Compatible Waveguide Crossing Arrays Based on Multimode Bloch Waves and Imaginary Coupling

    OpenAIRE

    Liu, Yangyang; Shainline, Jeffrey M.; Zeng, Xiaoge; Popovic, Milos A.

    2013-01-01

    We experimentally demonstrate broadband waveguide crossing arrays showing ultra low loss down to $0.04\\,$dB/crossing ($0.9\\%$), matching theory, and crosstalk suppression over $35\\,$dB, in a CMOS-compatible geometry. The principle of operation is the tailored excitation of a low-loss spatial Bloch wave formed by matching the periodicity of the crossing array to the difference in propagation constants of the 1$^\\text{st}$- and 3$^\\text{rd}$-order TE-like modes of a multimode silicon waveguide....

  10. Characterisation of an ultra low-background point contact HPGe well-detector for an underground laboratory.

    Science.gov (United States)

    Hult, Mikael; Marissens, Gerd; Stroh, Heiko; Lutter, Guillaume; Tzika, Faidra; Marković, Nikola

    2017-08-03

    Since a few years there are well-type HPGe-detectors with a small, point-like, anode contacts available commercially. This paper describes the characterisation of the first ultra low-background, so-called, SAGe™ well detector with regards to resolution and background performance. Inside a passive lead/copper shield in the underground laboratory HADES a background count rate of 690 ± 6d(-1) (268 ± 3d(-1) per kg Ge) was recorded 19 months after taking it underground. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Mode-locked Yb-doped fiber laser emitting broadband pulses at ultra-low repetition rates

    CERN Document Server

    Bowen, Patrick; Provo, Richard; Harvey, John D; Broderick, Neil G R

    2016-01-01

    We report on an environmentally stable, Yb-doped, all-normal dispersion, mode-locked fibre laser that is capable of creating broadband pulses with ultra-low repetition rates. Specifically, through careful positioning of fibre sections in an all-PM-fibre cavity mode-locked with a nonlinear amplifying loop mirror, we achieve stable pulse trains with repetition rates as low as 506 kHz. The pulses have several nanojules of energy and are compressible down to ultrashort (< 500 fs) durations.

  12. Ultra-low friction and excellent elastic recovery of fullerene-like hydrogenated carbon film based on multilayer design

    Indian Academy of Sciences (India)

    YANSHUANG MENG; XIAOLONG JIA; FULIANG ZHU; JUNYAN ZHANG

    2017-09-01

    Multilayer fullerene-like hydrogenated carbon (FL-C:H) films were synthesized by using the chemical vapourdeposition technique with a different flow rate of methane. The typical fullerene-like structure of as-prepared films wasinvestigated by using transmission electron microscopy and Raman spectra. The prepared multilayered FL-C:H films showeda high elastic recovery ($\\sim$90%), ultra-low friction coefficient ($\\sim$0.019) and low wear rate ($\\sim 3.0 \\times 10^{−9}$ mm$^3$ Nm$^{−1}$) in humid air.

  13. Ultra-low power all-optical switch using a single quantum dot embedded in a photonic wire

    DEFF Research Database (Denmark)

    Nguyen, H.A.; Grange, T.; Malik, N.S.

    the resonant reflectivity of the laser coupled to the lower transition (see fig. 1c). By performing reflectivity experiment, we show that a coupling laser of 10 nW (50 photons per emitter lifetime) can modify the transmission of the probe laser, realizing an ultra-low power all-optical switch....... [1,2]. We exploit here its broad operation bandwidth (>100 nm around 950 nm) to efficiently address two different transitions of the QD with two cw laser beams (fig. 1b). The laser coupled to the upper transition leads to a Rabi splitting of the intermediate state (Autler-Townes effect), affecting...

  14. Temporal and Storage Effects on Ultra-Low Volume Droplets of Insecticides Collected on Teflon-Coated Slides

    Science.gov (United States)

    2013-01-01

    popularity, use of glass microscope slides is still the preferred field method (Carroll and Bourg 1979, Dennett et al. 2006). The Depart- ment of Defense (DoD...REFERENCES CITED Anderson CH, Schulte W. 1971. Tef lonH as a surface for deposition of aerosol droplets. Mosq News 31:499–504. Carroll MK, Bourg JA

  15. Assessing the impacts of truck based ultra-low volume applications of mosquito adulticides on honey bees (Apis mellifera)

    Science.gov (United States)

    Mosquito control reduces populations of mosquitoes to minimize the risk of mosquito-borne diseases. As part of an integrated approach to mosquito control, application of adulticides can be effective in rapidly reducing mosquito populations during times of high arbovirus transmission. However, impact...

  16. Tug fleet and ground operations schedules and controls. Volume 1: Executive summary

    Science.gov (United States)

    1975-01-01

    This study presents Tug Fleet and Ground Operations Schedules and Controls plan. This plan was developed and optimized out of a combination of individual Tug program phased subplans, special emphasis studies, contingency analyses and sensitivity analyses. The subplans cover the Tug program phases: (1) Tug operational, (2) Interim Upper Stage (IUS)/Tug fleet utilization, (3) and IUS/Tug payload integration, (4) Tug site activation, (5) IUS/Tug transition, (6) Tug acquisition. Resource requirements (facility, GSE, TSE, software, manpower, logistics) are provided in each subplan, as are appropriate Tug processing flows, active and total IUS and Tug fleet requirements, fleet management and Tug payload integration concepts, facility selection recommendations, site activation and IUS to Tug transition requirements. The impact of operational concepts on Tug acquisition is assessed and the impact of operating Tugs out of KSC and WTR is analyzed and presented showing WTR as a delta. Finally, cost estimates for fleet management and ground operations of the DDT&E and operational phases of the Tug program are given.

  17. Developing an Ice Volume Estimate of Jarvis Glacier, Alaska, using Ground-Penetrating Radar and High Resolution Satellite Imagery

    Science.gov (United States)

    Wu, N. L.; Campbell, S. W.; Douglas, T. A.; Osterberg, E. C.

    2013-12-01

    Jarvis Glacier is an important water source for Fort Greely and Delta Junction, Alaska. Yet with warming summer temperatures caused by climate change, the glacier is melting rapidly. Growing concern of a dwindling water supply has caused significant research efforts towards determining future water resources from spring melt and glacier runoff which feeds the community on a yearly basis. The main objective of this project was to determine the total volume of the Jarvis Glacier. In April 2012, a centerline profile of the Jarvis Glacier and 15 km of 100 MHz ground-penetrating radar (GPR) profiles were collected in cross sections to provide ice depth measurements. These depth measurements were combined with an interpreted glacier boundary (depth = 0 m) from recently collected high resolution WorldView satellite imagery to estimate total ice volume. Ice volume was calculated at 0.62 km3 over a surface area of 8.82 km2. However, it is likely that more glacier-ice exists within Jarvis Glacier watershed considering the value calculated with GPR profiles accounts for only the glacier ice within the valley and not for the valley side wall ice. The GLIMS glacier area database suggests that the valley accounts for approximately 50% of the total ice covered watershed. Hence, we are currently working to improve total ice volume estimates which incorporate the surrounding valley walls. Results from this project will be used in conjunction with climate change estimates and hydrological properties downstream of the glacier to estimate future water resources available to Fort Greely and Delta Junction.

  18. Dispensing of high concentration Ag nano-particles ink for ultra-low resistivity paper-based writing electronics.

    Science.gov (United States)

    Wang, Fuliang; Mao, Peng; He, Hu

    2016-02-17

    Paper-based writing electronics has received a lot of interest recently due to its potential applications in flexible electronics. To obtain ultra-low resistivity paper-based writing electronics, we developed a kind of ink with high concentration of Ag Nano-particles (up to 80 wt%), as well as a related dispensing writing system consisting an air compressor machine and a dispenser. Additionally, we also demonstrated the writability and practical application of our proposed ink and writing system. Based on the study on the effect of sintering time and pressure, we found the optimal sintering time and pressure to obtain high quality Ag NPs wires. The electrical conductivity of nano-silver paper-based electronics has been tested using the calculated resistivity. After hot-pressure sintering at 120 °C, 25 MPa pressure for 20 minutes, the resistivity of silver NPs conductive tracks was 3.92 × 10(-8) (Ωm), only 2.45 times of bulk silver. The mechanical flexibility of nano-silver paper-based electronics also has been tested. After 1000 bending cycles, the resistivity slightly increased from the initial 4.01 × 10(-8) to 5.08 × 10(-8) (Ωm). With this proposed ink preparation and writing system, a kind of paper-based writing electronics with ultra-low resistivity and good mechanical flexibility was achieved.

  19. Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

    Science.gov (United States)

    Di Pendina, G.; Zianbetov, E.; Beigne, E.

    2015-05-01

    Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remaining in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28 nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160 mV up to 920 mV. The leakage current can be reduced to 154 pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes.

  20. Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

    Energy Technology Data Exchange (ETDEWEB)

    Di Pendina, G., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr; Zianbetov, E., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr [Univ. Grenoble Alpes, INAC-SPINTEC, F-38000 Grenoble (France); CNRS, SPINTEC, F-38000 Grenoble (France); CEA, INAC-SPINTEC, F-38000 Grenoble (France); Beigne, E., E-mail: gregory.dipendina@cea.fr, E-mail: eldar.zianbetov@cea.fr, E-mail: edith.beigne@cea.fr [Univ. Grenoble Alpes, CEA, LETI, F-38000 Grenoble (France)

    2015-05-07

    Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remaining in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28 nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160 mV up to 920 mV. The leakage current can be reduced to 154 pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes.

  1. Ultra Low Energy Switching of Ferromagnet with Perpendicular Anisotropy on Topological Insulator by Voltage Controlled Magnetic Anisotropy

    Science.gov (United States)

    Ghosh, Bahniman; Pramanik, Tanmoy; Dey, Rik; Roy, Urmimala; Register, Leonard; Banerjee, Sanjay

    2015-03-01

    We propose and demonstrate, through simulation, an ultra low energy memory device on a topological insulator thin film. The device consists of a thin layer of Fe deposited on the surface of a topological insulator, Bi2Se3. The top surface of Fe is covered with MgO so that the ferromagnetic layer has perpendicular anisotropy. Current is passed on the surface of the topological insulator which switches the magnetization of the Fe ferromagnet through strong exchange interaction, between electrons contributing to the surface current on the Bi2Se3 and the d electrons in the ferromagnet, and spin transfer torque due to shunting of current through the ferromagnet. Voltage controlled magnetic anisotropy enables ultra low energy switching. Our micromagnetic simulations, predict switching time of the order of 2.4 ns and switching energy of the order of 0.16 fJ for a ferromagnetic bit with thermal stability of 90 kBT. The proposed structure combines the advantages of both large spin torque from topological insulators and those of perpendicular anisotropy materials. This work is supported by NRI SWAN and NSF NASCENT Center.

  2. Ultra-low-frequency vertical vibration isolator based on a two-stage beam structure for absolute gravimetry

    Science.gov (United States)

    Wang, G.; Wu, K.; Hu, H.; Li, G.; Wang, L. J.

    2016-10-01

    To reduce seismic and environmental vibration noise, ultra-low-frequency vertical vibration isolation systems play an important role in absolute gravimetry. For this purpose, an isolator based on a two-stage beam structure is proposed and demonstrated. The isolator has a simpler and more robust structure than the present ultra-low-frequency vertical active vibration isolators. In the system, two beams are connected to a frame using flexural pivots. The upper beam is suspended from the frame with a normal hex spring and the lower beam is suspended from the upper one using a zero-length spring. The pivot of the upper beam is not vertically above the pivot of the lower beam. With this special design, the attachment points of the zero-length spring to the beams can be moved to adjust the effective stiffness. A photoelectric detector is used to detect the angle between the two beams, and a voice coil actuator attached to the upper beam is controlled by a feedback circuit to keep the angle at a fixed value. The system can achieve a natural period of 100 s by carefully moving the attachment points of the zero-length spring to the beams and tuning the feedback parameters. The system has been used as an inertial reference in the T-1 absolute gravimeter. The experiment results demonstrate that the system has significant vibration isolation performance that holds promise in applications such as absolute gravimeters.

  3. An Analog Circuit Approximation of the Discrete Wavelet Transform for Ultra Low Power Signal Processing in Wearable Sensor Nodes

    Science.gov (United States)

    Casson, Alexander J.

    2015-01-01

    Ultra low power signal processing is an essential part of all sensor nodes, and particularly so in emerging wearable sensors for biomedical applications. Analog signal processing has an important role in these low power, low voltage, low frequency applications, and there is a key drive to decrease the power consumption of existing analog domain signal processing and to map more signal processing approaches into the analog domain. This paper presents an analog domain signal processing circuit which approximates the output of the Discrete Wavelet Transform (DWT) for use in ultra low power wearable sensors. Analog filters are used for the DWT filters and it is demonstrated how these generate analog domain DWT-like information that embeds information from Butterworth and Daubechies maximally flat mother wavelet responses. The Analog DWT is realised in hardware via gmC circuits, designed to operate from a 1.3 V coin cell battery, and provide DWT-like signal processing using under 115 nW of power when implemented in a 0.18 μm CMOS process. Practical examples demonstrate the effective use of the new Analog DWT on ECG (electrocardiogram) and EEG (electroencephalogram) signals recorded from humans. PMID:26694414

  4. An ultra-low power CMOS image sensor with on-chip energy harvesting and power management capability.

    Science.gov (United States)

    Cevik, Ismail; Huang, Xiwei; Yu, Hao; Yan, Mei; Ay, Suat U

    2015-03-06

    An ultra-low power CMOS image sensor with on-chip energy harvesting and power management capability is introduced in this paper. The photodiode pixel array can not only capture images but also harvest solar energy. As such, the CMOS image sensor chip is able to switch between imaging and harvesting modes towards self-power operation. Moreover, an on-chip maximum power point tracking (MPPT)-based power management system (PMS) is designed for the dual-mode image sensor to further improve the energy efficiency. A new isolated P-well energy harvesting and imaging (EHI) pixel with very high fill factor is introduced. Several ultra-low power design techniques such as reset and select boosting techniques have been utilized to maintain a wide pixel dynamic range. The chip was designed and fabricated in a 1.8 V, 1P6M 0.18 µm CMOS process. Total power consumption of the imager is 6.53 µW for a 96 × 96 pixel array with 1 V supply and 5 fps frame rate. Up to 30 μW of power could be generated by the new EHI pixels. The PMS is capable of providing 3× the power required during imaging mode with 50% efficiency allowing energy autonomous operation with a 72.5% duty cycle.

  5. An Analog Circuit Approximation of the Discrete Wavelet Transform for Ultra Low Power Signal Processing in Wearable Sensor Nodes.

    Science.gov (United States)

    Casson, Alexander J

    2015-12-17

    Ultra low power signal processing is an essential part of all sensor nodes, and particularly so in emerging wearable sensors for biomedical applications. Analog signal processing has an important role in these low power, low voltage, low frequency applications, and there is a key drive to decrease the power consumption of existing analog domain signal processing and to map more signal processing approaches into the analog domain. This paper presents an analog domain signal processing circuit which approximates the output of the Discrete Wavelet Transform (DWT) for use in ultra low power wearable sensors. Analog filters are used for the DWT filters and it is demonstrated how these generate analog domain DWT-like information that embeds information from Butterworth and Daubechies maximally flat mother wavelet responses. The Analog DWT is realised in hardware via g(m)C circuits, designed to operate from a 1.3 V coin cell battery, and provide DWT-like signal processing using under 115 nW of power when implemented in a 0.18 μm CMOS process. Practical examples demonstrate the effective use of the new Analog DWT on ECG (electrocardiogram) and EEG (electroencephalogram) signals recorded from humans.

  6. An Analog Circuit Approximation of the Discrete Wavelet Transform for Ultra Low Power Signal Processing in Wearable Sensor Nodes

    Directory of Open Access Journals (Sweden)

    Alexander J. Casson

    2015-12-01

    Full Text Available Ultra low power signal processing is an essential part of all sensor nodes, and particularly so in emerging wearable sensors for biomedical applications. Analog signal processing has an important role in these low power, low voltage, low frequency applications, and there is a key drive to decrease the power consumption of existing analog domain signal processing and to map more signal processing approaches into the analog domain. This paper presents an analog domain signal processing circuit which approximates the output of the Discrete Wavelet Transform (DWT for use in ultra low power wearable sensors. Analog filters are used for the DWT filters and it is demonstrated how these generate analog domain DWT-like information that embeds information from Butterworth and Daubechies maximally flat mother wavelet responses. The Analog DWT is realised in hardware via g m C circuits, designed to operate from a 1.3 V coin cell battery, and provide DWT-like signal processing using under 115 nW of power when implemented in a 0.18 μm CMOS process. Practical examples demonstrate the effective use of the new Analog DWT on ECG (electrocardiogram and EEG (electroencephalogram signals recorded from humans.

  7. Fabrication of hard-coated optical absorbers with microstructured surfaces using etched ion tracks: Toward broadband ultra-low reflectance

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, Kuniaki, E-mail: k.amemiya@aist.go.jp [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8563 (Japan); Koshikawa, Hiroshi; Yamaki, Tetsuya; Maekawa, Yasunari [Quantum Beam Science Center, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Shitomi, Hiroshi; Numata, Takayuki; Kinoshita, Kenichi; Tanabe, Minoru; Fukuda, Daiji [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8563 (Japan)

    2015-08-01

    Highlights: • A hard-coated optical absorber with microstructured surface was fabricated. • Etched ion tracks coated with diamond-like carbon were used. • The reflectance was below 2% for wavelengths in the 400–1400 nm range. • Fabricated optical absorber exhibited temporal durability and mechanical stability. • Further improvement of the design and process will yield reflectance of ∼0.1%. - Abstract: Broadband low reflectance materials have various applications in the field of optical energy management; however, materials with ultra-low reflectance (below 0.1%) have been considered as mechanically delicate. We have developed a novel hard-surface optical absorber with microstructured, diamond-like carbon coated ion tracks on CR-39 plastic substrate. The spectral reflectance of the first prototype was below 2% for wavelengths ranging from 400 nm to 1400 nm; moreover, the optical absorber had mechanically hard surface and exhibited temporal durability. Choosing the appropriate design of the surface structure and coating layer is likely to reduce the reflectance to the order of 0.1%. This technique yields easy-to-handle broadband ultra-low reflectance absorbers.

  8. Ultra low Pt-loading electrode prepared by displacement of electrodeposited Cu particles on a porous carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Liao, M.J. [The State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Wei, Z.D.; Li, L. [The State Key Laboratory of Power Transmission Equipment and System Security and New Technology, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); School of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Chen, S.G.; Ji, M.B.; Wang, Y.Q. [School of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2010-08-15

    Ultra low Pt-loading and high Pt utilization electrodes were prepared by displacement of electrodeposited Cu on a porous carbon electrode. Copper particles were electrodeposited on a porous carbon electrode (PCE) by four-step deposition (FSD) at first. The size and dispersion of deposited Cu particles were markedly improved with application of the FSD. The Cu deposits were then displaced by platinum as dipping a Cu/PCE in a platinum salt solution. Sequentially, Pt particles supported on the PCE were obtained. The Pt/PCE electrode prepared via the FSD of Cu overcomes the problem of the hydrogen evolution reaction accompanied with direct platinum electrochemical deposition, and has a high Pt dispersion. The single cell consisting of the electrodes Pt/PCE via the FSD of Cu outputs a power of 0.45 W cm{sup -2} with ultra low Pt loadings of 0.196 mg cm{sup -2} MEA (0.098 mg cm{sup -2} per each side of the MEA) at no backpressure of reactant gases. (author)

  9. SEMICONDUCTOR INTEGRATED CIRCUITS: Design and realization of an ultra-low-power low-phase-noise CMOS LC-VCO

    Science.gov (United States)

    Xiushan, Wu; Zhigong, Wang; Zhiqun, Li; Jun, Xia; Qing, Li

    2010-08-01

    A fully integrated cross-coupled LC tank voltage-controlled oscillator (LC-VCO) using transformer feedback is proposed to achieve a low phase noise and ultra-low-power design even at a supply below the threshold voltage. The ultra-low-power VCO is implemented in the mixed-signal and RF 1P6M 0.18-μm CMOS technology of SMIC. The measured phase noise is -125.3 dBc/Hz at an offset frequency of 1 MHz from a carrier of 2.433 GHz, while the VCO core circuit draws only 640 μW from a 0.4-V supply. The designed VCO can cover a frequency range from 2.28 to 2.48 GHz. The tuning range of the circuit is 200 MHz (8.7%) and the FOM is -195.7 dB, which is suitable for an IEEE 802.11b receiver.

  10. Ground-water monitoring compliance projects for Hanford Site facilities: Progress report for the period April 1 to June 30, 1988: Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    1988-09-01

    This is Volume 2 of a two-volume set of documents that describes the progress of 10 Hanford Site ground-water monitoring projects for the period April 1 to June 30, 1988. This volume discusses as-built diagrams, drilling logs, and geophysical logs for wells drilled during this period in the 100-N Area (Appendix A) and near the 216-A-36B Crib (Appendix B). Volume 1 discusses the 10 projects. This work was supported by the US Department of Energy under Contract AC06-76RL01830.

  11. Ultra-low dose CT attenuation correction for PET/CT: analysis of sparse view data acquisition and reconstruction algorithms

    Science.gov (United States)

    Rui, Xue; Cheng, Lishui; Long, Yong; Fu, Lin; Alessio, Adam M.; Asma, Evren; Kinahan, Paul E.; De Man, Bruno

    2015-09-01

    For PET/CT systems, PET image reconstruction requires corresponding CT images for anatomical localization and attenuation correction. In the case of PET respiratory gating, multiple gated CT scans can offer phase-matched attenuation and motion correction, at the expense of increased radiation dose. We aim to minimize the dose of the CT scan, while preserving adequate image quality for the purpose of PET attenuation correction by introducing sparse view CT data acquisition. We investigated sparse view CT acquisition protocols resulting in ultra-low dose CT scans designed for PET attenuation correction. We analyzed the tradeoffs between the number of views and the integrated tube current per view for a given dose using CT and PET simulations of a 3D NCAT phantom with lesions inserted into liver and lung. We simulated seven CT acquisition protocols with {984, 328, 123, 41, 24, 12, 8} views per rotation at a gantry speed of 0.35 s. One standard dose and four ultra-low dose levels, namely, 0.35 mAs, 0.175 mAs, 0.0875 mAs, and 0.043 75 mAs, were investigated. Both the analytical Feldkamp, Davis and Kress (FDK) algorithm and the Model Based Iterative Reconstruction (MBIR) algorithm were used for CT image reconstruction. We also evaluated the impact of sinogram interpolation to estimate the missing projection measurements due to sparse view data acquisition. For MBIR, we used a penalized weighted least squares (PWLS) cost function with an approximate total-variation (TV) regularizing penalty function. We compared a tube pulsing mode and a continuous exposure mode for sparse view data acquisition. Global PET ensemble root-mean-squares-error (RMSE) and local ensemble lesion activity error were used as quantitative evaluation metrics for PET image quality. With sparse view sampling, it is possible to greatly reduce the CT scan dose when it is primarily used for PET attenuation correction with little or no measureable effect on the PET image. For the four ultra-low dose

  12. Ultra-low dose CT attenuation correction for PET/CT: analysis of sparse view data acquisition and reconstruction algorithms.

    Science.gov (United States)

    Rui, Xue; Cheng, Lishui; Long, Yong; Fu, Lin; Alessio, Adam M; Asma, Evren; Kinahan, Paul E; De Man, Bruno

    2015-10-07

    For PET/CT systems, PET image reconstruction requires corresponding CT images for anatomical localization and attenuation correction. In the case of PET respiratory gating, multiple gated CT scans can offer phase-matched attenuation and motion correction, at the expense of increased radiation dose. We aim to minimize the dose of the CT scan, while preserving adequate image quality for the purpose of PET attenuation correction by introducing sparse view CT data acquisition.We investigated sparse view CT acquisition protocols resulting in ultra-low dose CT scans designed for PET attenuation correction. We analyzed the tradeoffs between the number of views and the integrated tube current per view for a given dose using CT and PET simulations of a 3D NCAT phantom with lesions inserted into liver and lung. We simulated seven CT acquisition protocols with {984, 328, 123, 41, 24, 12, 8} views per rotation at a gantry speed of 0.35 s. One standard dose and four ultra-low dose levels, namely, 0.35 mAs, 0.175 mAs, 0.0875 mAs, and 0.043 75 mAs, were investigated. Both the analytical Feldkamp, Davis and Kress (FDK) algorithm and the Model Based Iterative Reconstruction (MBIR) algorithm were used for CT image reconstruction. We also evaluated the impact of sinogram interpolation to estimate the missing projection measurements due to sparse view data acquisition. For MBIR, we used a penalized weighted least squares (PWLS) cost function with an approximate total-variation (TV) regularizing penalty function. We compared a tube pulsing mode and a continuous exposure mode for sparse view data acquisition. Global PET ensemble root-mean-squares-error (RMSE) and local ensemble lesion activity error were used as quantitative evaluation metrics for PET image quality.With sparse view sampling, it is possible to greatly reduce the CT scan dose when it is primarily used for PET attenuation correction with little or no measureable effect on the PET image. For the four ultra-low dose levels

  13. Phase I Rinal Report: Ultra-Low Background Alpha Activity Counter

    Energy Technology Data Exchange (ETDEWEB)

    Warburton, W.K.

    2005-07-22

    In certain important physics experiments that search for rare-events, such as neutrino or double beta decay detections, it is critical to minimize the number of background events that arise from alpha particle emitted by the natural radioactivity in the materials used to construct the experiment. Similarly, the natural radioactivity in materials used to connect and package silicon microcircuits must also be minimized in order to eliminate ''soft errors'' caused by alpha particles depositing charges within the microcircuits and thereby changing their logic states. For these, and related reasons in the areas of environmental cleanup and nuclear materials tracking, there is a need that is important from commercial, scientific, and national security perspectives to develop an ultra-low background alpha counter that would be capable of measuring materials' alpha particle emissivity at rates well below 0.00001 alpha/cm{sup 2}/hour. This rate, which corresponds to 24 alpha particles per square meter per day, is essentially impossible to achieve with existing commercial instruments because the natural radioactivity of the materials used to construct even the best of these counters produces background rates at the 0.005 alpha/cm{sup 2}/hr level. Our company (XIA) had previously developed an instrument that uses electronic background suppression to operate at the 0.0005 0.005 alpha/cm{sup 2}/hr level. This patented technology sets up an electric field between a large planar sample and a large planar anode, and fills the gap with pure Nitrogen. An alpha particle entering the chamber ionizes the Nitrogen, producing a ''track'' of electrons, which drift to the anode in the electric field. Tracks close to the anode take less than 10 microseconds (us) to be collected, giving a preamplifier signal with a 10 us risetime. Tracks from the sample have to drift across the full anode-sample gap and produce a 35 us risetime signal. By

  14. Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results

    Energy Technology Data Exchange (ETDEWEB)

    Yuen, C. R.; Martino, L. E.; Biang, R. P.; Chang, Y. S.; Dolak, D.; Van Lonkhuyzen, R. A.; Patton, T. L.; Prasad, S.; Quinn, J.; Rosenblatt, D. H.; Vercellone, J.; Wang, Y. Y.

    2000-03-14

    This report presents the results of the remedial investigation (RI) conducted at J-Field in the Edgewood Area of Aberdeen Proving Ground (APG), a U.S. Army installation located in Harford County, Maryland. Since 1917, activities in the Edgewood Area have included the development, manufacture, and testing of chemical agents and munitions and the subsequent destruction of these materials at J-Field by open burning and open detonation. These activities have raised concerns about environmental contamination at J-Field. This RI was conducted by the Environmental Conservation and Restoration Division, Directorate of Safety, Health and Environmental Division of APG, pursuant to requirements outlined under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). The RI was accomplished according to the procedures developed by the U.S. Environmental Protection Agency (EPA 1988). The RI provides a comprehensive evaluation of the site conditions, nature of contaminants present, extent of contamination, potential release mechanisms and migration pathways, affected populations, and risks to human health and the environment. This information will be used as the basis for the design and implementation of remedial actions to be performed during the remedial action phase, which will follow the feasibility study (FS) for J-Field.

  15. Variable thickness transient ground-water flow model. Volume 3. Program listings

    Energy Technology Data Exchange (ETDEWEB)

    Reisenauer, A.E.

    1979-12-01

    The Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program is developing and applying the methodology for assessing the far-field, long-term post-closure safety of deep geologic nuclear waste repositories. AEGIS is being performed by Pacific Northwest Laboratory (PNL) under contract with the Office of Nuclear Waste Isolation (OWNI) for the Department of Energy (DOE). One task within AEGIS is the development of methodology for analysis of the consequences (water pathway) from loss of repository containment as defined by various release scenarios. Analysis of the long-term, far-field consequences of release scenarios requires the application of numerical codes which simulate the hydrologic systems, model the transport of released radionuclides through the hydrologic systems to the biosphere, and, where applicable, assess the radiological dose to humans. Hydrologic and transport models are available at several levels of complexity or sophistication. Model selection and use are determined by the quantity and quality of input data. Model development under AEGIS and related programs provides three levels of hydrologic models, two levels of transport models, and one level of dose models (with several separate models). This is the third of 3 volumes of the description of the VTT (Variable Thickness Transient) Groundwater Hydrologic Model - second level (intermediate complexity) two-dimensional saturated groundwater flow.

  16. PARTICULATE CHARACTERIZATION AND ULTRA LOW-NOx BURNER FOR THE CONTROL OF NO{sub x} AND PM{sub 2.5} FOR COAL FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Ralph Bailey; Hamid Sarv; Jim Warchol; Debi Yurchison

    2001-09-30

    sufficient to evaluate the particle size distribution, but was of insufficient size to permit reliable chemical analysis. The size classified fly ash from the inlet of the ESP was used for detailed chemical analyses. Chemical analyses of the fly ash samples from the ESP outlet using a high volume sampler were performed for comparison to the size classified results at the inlet. For all test conditions the particulate removal efficiency of the ESP exceeded 99.3% and emissions were less than the NSPS limits of {approx}48 mg/dscm. With constant combustion conditions, the removal efficiency of the ESP increased as the ESP voltage and Specific Collection Area (SCA) increased. The associated decrease in particle emissions occurred in size fractions both larger and smaller than 2.5 microns. For constant ESP voltage and SCA, the removal efficiency for the ultra low-NO{sub x} combustion ash (99.4-99.6%) was only slightly less than for the low-NO{sub x} combustion ash (99.7%). The decrease in removal efficiency was accompanied by a decrease in ESP current. The emission of PM{sub 2.5} from the ESP did not change significantly as a result of the change in combustion conditions. Most of the increase in emissions was in the size fraction greater than 2.5 microns, indicating particle re-entrainment. These results may be specific to the coal tested in this program. In general, the concentration of inorganic elements and trace species in the fly ash at the ESP inlet was dependent on the particle size fraction. The smallest particles tended to have higher concentrations of inorganic elements/trace species than larger particles. The concentration of most elements by particle size range was independent of combustion condition and the concentration of soluble ions in the fly ash showed little change with combustion condition when evaluated on a carbon free basis.

  17. Ultra-low altitude and low spraying technology research with UAV in paddy

    Science.gov (United States)

    Aerial application has characteristics of low-volume, small droplet, and possibility of drift. To control rice planthopper, leaf roller and blast, the research aimed at screening agrichemicals and determining the feasibility of using high concentration of conventional dosage for aerial application....

  18. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Volume 2. Special test cases

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-08-01

    This document was written for the National Low-Level Waste Management Program to provide guidance for managers and site operators who need to select ground-water transport codes for assessing shallow-land burial site performance. The guidance given in this report also serves the needs of applications-oriented users who work under the direction of a manager or site operator. The guidelines are published in two volumes designed to support the needs of users having different technical backgrounds. An executive summary, published separately, gives managers and site operators an overview of the main guideline report. Volume 1, titled ''Guideline Approach,'' consists of Chapters 1 through 5 and a glossary. Chapters 2 through 5 provide the more detailed discussions about the code selection approach. This volume, Volume 2, consists of four appendices reporting on the technical evaluation test cases designed to help verify the accuracy of ground-water transport codes. 20 refs.

  19. Living with Ultra-Low Vision: An Inventory of Self-Reported Visually Guided Activities by Individuals with Profound Visual Impairment.

    Science.gov (United States)

    Adeyemo, Olukemi; Jeter, Pamela E; Rozanski, Collin; Arnold, Ellen; Dalvin, Lauren A; Swenor, Bonnielin; Dagnelie, Gislin

    2017-05-01

    To understand how individuals with profound visual impairment (ultra-low vision, ULV) use their remaining vision. Forty-six participants with ULV (visual acuity ≤ 200/500 in the better seeing eye) were divided into nine focus groups (4-6 individuals per group) and met either in person (n = 2) or over the phone (n = 7). Discussions were guided by the Massof Activity Inventory. Audio recordings were transcribed and analyzed for visual activities that were then classified along two visual categorizations - functional domains and visual aspects. The latter was based on a Grounded Theory classification of participants' descriptions. Seven hundred sixty activities were reported. By functional domain they were classified as reading/shape recognition (10%), mobility (17%), visual motor (24%), and visual information gathering (49%). By visual aspects, they were classified as contrast (43%), luminance (17%), environmental lighting (9%), familiarity (3%), motion perception (5%), distance (7%), size (9%), eccentricity (5%), depth perception (1%), and other/miscellaneous (1%). More than one visual aspect may be critical for an activity: participants reported that contrast plays a role in 68% of visual activities, followed by luminance (27%), environmental lighting (14%), and size (14%). Visual aspects, primarily contrast, were found to be critical factors enabling ULV individuals to perform visual activities. This inventory, part of the Prosthetic Low Vision Rehabilitation (PLoVR) curriculum development study, provides a unique perspective into the visual world of the nearly blind, and can be used in the development of a Visual Functioning Questionnaire (VFQ) and visual performance measures suited for ULV populations.

  20. DTMOS-Based 0.4V Ultra Low-Voltage Low-Power VDTA Design and Its Application to EEG Data Processing

    Directory of Open Access Journals (Sweden)

    A. Uygur

    2013-06-01

    Full Text Available In this paper, an ultra low-voltage, ultra low-power voltage differencing transconductance amplifier (VDTA is proposed. DTMOS (Dynamic Threshold Voltage MOS transistors are employed in the design to effectively use the ultra low supply voltage. The proposed VDTA is composed of two operational transconductance amplifiers operating in the subthreshold region. Using TSMC 0.18µm process technology parameters with symmetric ±0.2V sup¬ply voltage, the total power consumption of the VDTA block is found as just 5.96 nW when the transconductances have 3.3 kHz, 3 dB bandwidth. The proposed VDTA circuit is then used in a fourth-order double-tuned band-pass filter for processing real EEG data measurements. The filter achieves close to 64 dB dynamic range at 2% THD with a total power consumption of 12.7 nW.

  1. Towards an ultra-low-power electronically controllable array antenna for WSN

    CSIR Research Space (South Africa)

    Lysko, AA

    2012-09-01

    Full Text Available .g. [19], [17]. The design started with preparing a printed circuit board (PCB) layout for the RF switch. The layout is shown in Figure 1. The design was made to minimize the lengths of the paths between the antenna and the pole of the switch... port (PORT_1) and the two ports of the SPDT RF switch (short- and open-circuited, respectively). (b) Print-screen of the metallization layer for the RF switch with 6 pads connected to a via for monopole, Vcc, control, ground and not connected (NC...

  2. Effects of Iterative Reconstruction Algorithms on Computer-assisted Detection (CAD) Software for Lung Nodules in Ultra-low-dose CT for Lung Cancer Screening.

    Science.gov (United States)

    Nomura, Yukihiro; Higaki, Toru; Fujita, Masayo; Miki, Soichiro; Awaya, Yoshikazu; Nakanishi, Toshio; Yoshikawa, Takeharu; Hayashi, Naoto; Awai, Kazuo

    2017-02-01

    This study aimed to evaluate the effects of iterative reconstruction (IR) algorithms on computer-assisted detection (CAD) software for lung nodules in ultra-low-dose computed tomography (ULD-CT) for lung cancer screening. We selected 85 subjects who underwent both a low-dose CT (LD-CT) scan and an additional ULD-CT scan in our lung cancer screening program for high-risk populations. The LD-CT scans were reconstructed with filtered back projection (FBP; LD-FBP). The ULD-CT scans were reconstructed with FBP (ULD-FBP), adaptive iterative dose reduction 3D (AIDR 3D; ULD-AIDR 3D), and forward projected model-based IR solution (FIRST; ULD-FIRST). CAD software for lung nodules was applied to each image dataset, and the performance of the CAD software was compared among the different IR algorithms. The mean volume CT dose indexes were 3.02 mGy (LD-CT) and 0.30 mGy (ULD-CT). For overall nodules, the sensitivities of CAD software at 3.0 false positives per case were 78.7% (LD-FBP), 9.3% (ULD-FBP), 69.4% (ULD-AIDR 3D), and 77.8% (ULD-FIRST). Statistical analysis showed that the sensitivities of ULD-AIDR 3D and ULD-FIRST were significantly higher than that of ULD-FBP (P CAD software in ULD-CT was improved by using IR algorithms. In particular, the performance of CAD in ULD-FIRST was almost equivalent to that in LD-FBP. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  3. An investigation on the ultra-low energy As ion implantation process and the dopant behaviour during thermal processing

    CERN Document Server

    Whelan, S

    2001-01-01

    Characterisation of the ultra-low energy (ULE) As ion implantation profile (dopant and damage distributions) in Si has been achieved using medium energy ion scattering (MEIS) and secondary ion mass spectrometry (SIMS), in conjunction with a sputter profile deconvolution code (IMPETUS). The Si damage re-growth, dopant substitutionality, diffusion and retention processes that occur during thermal annealing have been investigated as a function of the implant damage and anneal gas ambient. It has been shown that for dopant distributions with a range less than 100A, significant error in the SIMS depth scale occurs when assuming a constant erosion rate throughout sputtering. The sputter depth profile deconvolution code IMPETUS has been used to quantify the errors associated with this assumption. Accurate simulation of the ULE As ion implant process in Si incorporating oxide accumulation effects (segregation) and self-sputtering has been obtained and validated with high resolution MEIS measurements. The code calcula...

  4. 100 nm AlSb/InAs HEMT for Ultra-Low-Power Consumption, Low-Noise Applications

    Directory of Open Access Journals (Sweden)

    Cyrille Gardès

    2014-01-01

    Full Text Available We report on high frequency (HF and noise performances of AlSb/InAs high electron mobility transistor (HEMT with 100 nm gate length at room temperature in low-power regime. Extrinsic cut-off frequencies fT/fmax of 100/125 GHz together with minimum noise figure NFmin=0.5 dB and associated gain Gass=12 dB at 12 GHz have been obtained at drain bias of only 80 mV, corresponding to 4 mW/mm DC power dissipation. This demonstrates the great ability of AlSb/InAs HEMT for high-frequency operation combined with low-noise performances in ultra-low-power regime.

  5. Treatment of early arthritis using arthrofoon (ultra-low doses of antibodies to tumor necrosis factor-α

    Directory of Open Access Journals (Sweden)

    Lyudmila V Sizova

    2011-01-01

    Full Text Available The main aim of treatment of early rheumatoid arthritis (RA should be to achieve clinical remission to prevent structural damage and physical disability. Arthrofoon modifies production/activity of endogenous inhibitors of tumor necrosis factor-α (TNF-α. The sublingual rout is the most acceptable to ambulatory treatment because it does not produce the adverse reactions associated with intravenous therapy. The treatment with arthrofoon in outpatient with early RA is analyzed here. This report is devoted to the 28-year-old Russian woman who received arthrofoon due to suspicion of early RA. The strategy of early prescription of ultra-low doses of TNF-α antibody within two years was confirmed by the clinical improvement and delay of radiological disease progression in patient with undifferentiated arthritis or probable RA initially.

  6. Object reconstruction from thermal and shot noises corrupted block-based compressive ultra-low-light-level imaging measurements

    Science.gov (United States)

    Niu, Sen; Ke, Jun

    2016-10-01

    In this paper, block-based compressive ultra low-light-level imaging (BCU-imaging) is studied. Objects are divided into blocks. Features, or linear combinations of block pixels, instead of pixels, are measured for each block to improve system measurement SNR and thus object reconstructions. Thermal noise and shot noise are discussed for object reconstruction. The former is modeled as Gaussian noise. The latter is modeled as Poisson noise. Linear Wiener operator and linearized iterative Bregman algorithm are used to reconstruct objects from measurements corrupted by thermal noise. SPIRAL algorithm is used to reconstruct object from measurements with shot noise. Linear Wiener operator is also studied for measurements with shot noise, because Poisson noise is similar to Gaussian noise at large signal level and feature values are large enough to make this assumption feasible. Root mean square error (RMSE) is used to quantify system reconstruction quality.

  7. New polyimide-polyoxometalate nanocomposite materials with nanoporous structure and ultra-low dielectric constant, formed in supercritical carbon dioxide

    Science.gov (United States)

    Keshtov, Mukhamed; Said-Galiev, Ernest; Kochurov, Vitaliy; Khokhlov, Alexei

    2012-07-01

    Vinyltrimethoxysilane interaction with K8(SiW11O39) obtained polyoxometalate (Bu4N)4[SiW11O39{(CH2 = CH-Si)2O}](SiW11-CH = CH2). Synthesized two new fluorinated aromatic polyimide in two stages with a dielectric constant (k) in the range 2.70-2.75. On the basis of poly(amic acids) and a mixture of thermal imidization polyoxometalate obtained polyimide/polyoxometalate composite film. It was found that with increasing polyoxometalate in a mixture of 0 to 20 wt% the dielectric constant decreases from 2,75 to 1,70. Nanoporous materials with ultra-low dielectric constant in the range 1.31-1.64 in combination with high thermal (T10% = 536-570°C in N2) and mechanical characteristics using supercritical carbon dioxide have been developed on the basis of the obtained polyimide/polyoxometalate composite films.

  8. Plasticity and ultra-low stress induced twin boundary migration in nanotwinned Cu by in situ nanoindentation studies

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.; Chen, Y. [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Jian, J. [Department of Electrical Engineering, Texas A and M University, College Station, Texas 77843 (United States); Wang, H. [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Department of Electrical Engineering, Texas A and M University, College Station, Texas 77843 (United States); Zhang, X., E-mail: zhangx@tamu.edu [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Department of Mechanical Engineering, Texas A and M University, College Station, Texas 77843 (United States)

    2014-06-09

    Nanotwinned metals have rare combinations of mechanical strength and ductility. Previous studies have shown that detwinning occurs in plastically deformed nanotwinned metals. Although molecular dynamics simulations have predicted that fine nanotwins can migrate at low stress, there is little in situ evidence to validate such predictions. Also it is unclear if detwinning occurs prior to or succeeding plastic yielding. Here, by using in situ nanoindentation in a transmission electron microscope, we show that a non-elastic detwinning process in nanotwinned Cu occurred at ultra-low indentation stress (0.1 GPa), well before the stress necessary for plastic yielding. Furthermore, the in situ nanoindentation technique allows us to differentiate dislocation-nucleation dominated microscopic yielding preceding macroscopic yielding manifested by dislocation-transmission through twin boundaries. This study thus provides further insights for understanding plasticity in nanotwinned metals at microscopic levels.

  9. Ultra-low-loss CMOS-Compatible Waveguide Crossing Arrays Based on Multimode Bloch Waves and Imaginary Coupling

    CERN Document Server

    Liu, Yangyang; Zeng, Xiaoge; Popovic, Milos A

    2013-01-01

    We experimentally demonstrate broadband waveguide crossing arrays showing ultra low loss down to $0.04\\,$dB/crossing ($0.9\\%$), matching theory, and crosstalk suppression over $35\\,$dB, in a CMOS-compatible geometry. The principle of operation is the tailored excitation of a low-loss spatial Bloch wave formed by matching the periodicity of the crossing array to the difference in propagation constants of the 1$^\\text{st}$- and 3$^\\text{rd}$-order TE-like modes of a multimode silicon waveguide. Radiative scattering at the crossing points acts like a periodic imaginary-permittivity perturbation that couples two supermodes, which results in imaginary (radiative) propagation-constant splitting and gives rise to a low-loss, unidirectional breathing Bloch wave. This type of crossing array provides a robust implementation of a key component enabling dense photonic integration.

  10. An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

    Directory of Open Access Journals (Sweden)

    Antonio Sánchez

    2012-05-01

    Full Text Available This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 µW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA to support CSMA-based medium access control (MAC layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.

  11. An ultra-low power and flexible acoustic modem design to develop energy-efficient underwater sensor networks.

    Science.gov (United States)

    Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

    2012-01-01

    This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.

  12. Ultra-Low-Voltage Low-Power Bulk-Driven Quasi-Floating-Gate Operational Transconductance Amplifier

    Directory of Open Access Journals (Sweden)

    Ziad Alsibai

    2014-01-01

    Full Text Available A new ultra-low-voltage (LV low-power (LP bulk-driven quasi-floating-gate (BD-QFG operational transconductance amplifier (OTA is presented in this paper. The proposed circuit is designed using 0.18 μm CMOS technology. A supply voltage of ±0.3 V and a quiescent bias current of 5 μA are used. The PSpice simulation result shows that the power consumption of the proposed BD-QFG OTA is 13.4 μW. Thus, the circuit is suitable for low-power applications. In order to confirm that the proposed BD-QFG OTA can be used in analog signal processing, a BD-QFG OTA-based diodeless precision rectifier is designed as an example application. This rectifier employs only two BD-QFG OTAs and consumes only 26.8 μW.

  13. Ultra low voltage and low power Static Random Access Memory design using average 6.5T technique

    Directory of Open Access Journals (Sweden)

    Nagalingam RAJESWARAN

    2015-12-01

    Full Text Available Power Stringent Static Random Access Memory (SRAM design is very much essential in embedded systems such as biomedical implants, automotive electronics and energy harvesting devices in which battery life, input power and execution delay are of main concern. With reduced supply voltage, SRAM cell design will go through severe stability issues. In this paper, we present a highly stable average nT SRAM cell for ultra-low power in 125nm technology. The distinct difference between the proposed technique and other conventional methods is about the data independent leakage in the read bit line which is achieved by newly introduced block mask transistors. An average 6.5T SRAM and average 8T SRAM are designed and compared with 6T SRAM, 8T SRAM, 9T SRAM, 10T SRAM and 14T SRAM cells. The result indicates that there is an appreciable decrease in power consumption and delay.

  14. 100 nm AlSb/InAs HEMT for Ultra-Low-Power Consumption, Low-Noise Applications

    Science.gov (United States)

    Bagumako, Sonia; Desplanque, Ludovic; Wichmann, Nicolas; Bollaert, Sylvain; Danneville, François; Wallart, Xavier

    2014-01-01

    We report on high frequency (HF) and noise performances of AlSb/InAs high electron mobility transistor (HEMT) with 100 nm gate length at room temperature in low-power regime. Extrinsic cut-off frequencies fT/fmax of 100/125 GHz together with minimum noise figure NFmin = 0.5 dB and associated gain Gass = 12 dB at 12 GHz have been obtained at drain bias of only 80 mV, corresponding to 4 mW/mm DC power dissipation. This demonstrates the great ability of AlSb/InAs HEMT for high-frequency operation combined with low-noise performances in ultra-low-power regime. PMID:24707193

  15. Determination of ultra-low level 129I in vegetation using pyrolysis for iodine separation and accelerator mass spectrometry measurements

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Wang, Yanyun

    2016-01-01

    Radioactive isotopes of iodine are the most common radiological toxins from nuclear accidents due to their high release and high enrichment in human thyroid. Among the radioactive isotopes, long-lived 129I can not only be used for the estimation of the radioactive risk of short-lived radioactive...... isotopes of iodine to humans and ecosystems, but also for the investigation of the biogeochemical cycle and environmental behavior of iodine. Accurate determination of 129I in various environmental and biological samples is the key issue for these purposes. Due to its beta decay, low specific activity...... and ultra-low concentration in normal environmental and biological samples, it is important to efficiently separate iodine from the sample matrix and sensitively measure 129I. However, the complicated chemical properties of iodine and high organic content in biological samples make efficient separation...

  16. Fabrication of universal serial bus flash disk type microfluidic chip electrophoresis and application for protein analysis under ultra low voltage.

    Science.gov (United States)

    Cong, Hailin; Xu, Xiaodan; Yu, Bing; Liu, Huwei; Yuan, Hua

    2016-03-01

    A simple and effective universal serial bus (USB) flash disk type microfluidic chip electrophoresis (MCE) was developed by using poly(dimethylsiloxane) based soft lithography and dry film based printed circuit board etching techniques in this paper. The MCE had a microchannel diameter of 375 μm and an effective length of 25 mm. Equipped with a conventional online electrochemical detector, the device enabled effectively separation of bovine serum albumin, lysozyme, and cytochrome c in 80 s under the ultra low voltage from a computer USB interface. Compared with traditional capillary electrophoresis, the USB flash disk type MCE is not only portable and inexpensive but also fast with high separation efficiency.

  17. Effect of Batch Annealing Temperature on Microstructure and Resistance to Fish Scaling of Ultra-Low Carbon Enamel Steel

    Directory of Open Access Journals (Sweden)

    Zaiwang Liu

    2017-02-01

    Full Text Available In the present work, an ultra-low carbon enamel steel was batch annealed at different temperatures, and the effect of the batch annealing temperature on the microstructure and resistance to fish scaling was investigated by optical microscopy, transmission electron microscopy, and a hydrogen permeation test. The results show that the main precipitates in experimental steel are fine TiC and coarse Ti4C2S2 particles. The average sizes of both TiC and Ti4C2S2 increase with increasing the batch annealing temperature. The resistance to fish scaling decreases with increasing the annealing temperature, which is caused by the growth of ferrite grain and the coarsening of the TiC and Ti4C2S2 particles

  18. Continuous Cooling Transformation Behavior and Kinetic Models of Transformations for an Ultra-Low Carbon Bainitic Steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-min; CAI Qing-wu; YU Wei; LIXiao-lin; WANG Li-dong

    2012-01-01

    The aim was to investigate transformation behavior and transformation kinetics of an ultra-low carbon bai- nitic steel during continuous cooling. Continuous cooling transformation (CCT) curves of tested steel were measured by thermal dilatometer and metallographic structures at room temperature were observed by optical microscope. Then transformation kinetic equation of austenite to ferrite as well as austenite to bainite was established by analyzing the relationship of lnln]-l/(1--f)] and lnt in the kinetic equation on the basis of processed experimental data. Finally, the measured and calculated kinetic behaviors of the steel during continuous cooling were compared and growth pat- terns of transformed ferrite and bainite were analyzed. Results showed that calculated result was in reasonable agree- ment with the experimental data. It could be concluded that the growth modes of transformed ferrite and bainite were mainly one dimension as the Avrami exponents were between 1 and 2.

  19. Sensitivity to oscillation with a sterile fourth generation neutrino from ultra-low threshold neutrino-nucleus coherent scattering

    CERN Document Server

    Dutta, Bhaskar; Mahapatra, Rupak; Mirabolfathi, Nader; Strigari, Louis E; Walker, Joel W

    2015-01-01

    We discuss prospects for probing short-range sterile neutrino oscillation using neutrino-nucleus coherent scattering with ultra-low energy ($\\sim 10$ eV - 100 eV) recoil threshold cryogenic Si and Ge detectors. The analysis is performed in the context of a specific and contemporary reactor-based experimental proposal, developed in cooperation with the Nuclear Science Center at Texas A&M University, and references available technology based upon economical and scalable detector arrays. The baseline of the experiment is substantially shorter than existing measurements, as near as 1 meter from the reactor core, and is moreover variable, extending continuously up to a range of about 20~meters. This proximity and variety combine to provide extraordinary sensitivity to a wide spectrum of oscillation scales, while facilitating the tidy cancellation of leading systematic uncertainties in the reactor source. For expected exposures, we demonstrate sensitivity to first/fourth neutrino oscillation with a mass gap $\\D...

  20. An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks

    Science.gov (United States)

    Sánchez, Antonio; Blanc, Sara; Yuste, Pedro; Perles, Angel; Serrano, Juan José

    2012-01-01

    This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 μW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network. PMID:22969324

  1. Fully Integrated Ultra-Low Voltage Step-up Converter with Voltage Doubling LC-Tank for Energy Harvesting Applications

    Science.gov (United States)

    Jayaweera, H. M. P. C.; Pathirana, W. P. M. R.; Muhtaroğlu, Ali

    2015-12-01

    This paper reports the design, fabrication, and validation of a novel integrated interface circuit for ultra-low voltage step up converter in 0.18 μm CMOS technology. The circuit does not use off-chip components. Fully integrated centre-tap differential inductors are introduced in the proposed LC oscillator design to achieve 38% area reduction compared to the use of four separate inductors. The efficiency of the system is hence enhanced through the elimination of clock buffer circuits traditionally utilized to drive the step-up converter. The experimental results prove that the system can self-start, and step 0.25 V up to 1.7 V to supply a 46 μW load with 15.5% efficiency. The minimum validated input voltage is 0.15 V, which is boosted up to 1.2 V under open circuit conditions.

  2. Concurrent laparoscopic right hemicolectomy and ultra-low anterior resection with colonic J-pouch anal anastomosis for synchronous carcinoma.

    Science.gov (United States)

    Jafari Giv, M; Ho, Y H

    2007-03-01

    An extensive large bowel resection with a single anastomosis is the accustomed management option for widely spaced synchronous colorectal neoplasms. We report a successful case of concurrent laparoscopic right hemicolectomy and ultra-low anterior resection with colonic J-pouch anal anastomosis in an 85-year-old man with synchronous cancers of the hepatic flexure and lowrectum. This surgical technique is advantageous for elderly patients as it provides the benefits of multiple segmental resection and laparoscopic surgery while potentially reducing mortality, time of procedure, postoperative pain, ileus, length of hospitalization and direct cost of care, and improving independence at discharge. The technique for efficient multiple extractions of specimens and effective reconstitution of pneumoperitoneum for a multistaged procedure is discussed.

  3. Long-term ultra-low-dose acyclovir against varicella-zoster virus reactivation after allogeneic hematopoietic stem cell transplantation.

    Science.gov (United States)

    Asano-Mori, Yuki; Kanda, Yoshinobu; Oshima, Kumi; Kako, Shinichi; Shinohara, Akihito; Nakasone, Hideki; Sato, Hiroyuki; Watanabe, Takuro; Hosoya, Noriko; Izutsu, Koji; Asai, Takashi; Hangaishi, Akira; Motokura, Toru; Chiba, Shigeru; Kurokawa, Mineo

    2008-06-01

    To evaluate the efficacy of long-term prophylaxis with ultra-low-dose acyclovir against varicella-zoster virus (VZV) reactivation, we analyzed the records of 242 Japanese adult patients who underwent allogeneic hematopoietic stem cell transplantation for the first time from 1995 to 2006 at our hospital. We started long-term oral acyclovir at 200 mg/day in July 2001. Acyclovir was continued until the end of immunosuppressive therapy and at least 1 year after transplantation. Sixty-six patients developed VZV reactivation at a median of 248 days after HSCT, with a cumulative incidence of 34.7%. Only one breakthrough reactivation occurred during long-term acyclovir, which responded well to therapeutic dose of valacyclovir. The use of long-term acyclovir was the only independent determinant that significantly decreased the overall incidence of VZV reactivation (20% vs. 50%, P < 0.0001). With this prophylaxis, visceral dissemination and serious complications other than post-herpetic neuralgia was completely eliminated, and thereby need for hospitalization was significantly reduced (21% vs. 71%, P = 0.0034). Fifteen of the 57 patients who discontinued acyclovir developed VZV reactivation, with a cumulative incidence of 32.1%. VZV reactivation following discontinuation tended to occur in patients who were receiving immunosuppressive therapy at the cessation of acyclovir. These findings suggested that long-term prophylaxis of ultra-low-dose acyclovir resulted in a successful prevention of severe VZV-related symptoms and death, with a significantly decreased overall incidence of VZV reactivation. Prolongation of prophylactic acyclovir on profound immunosuppression might be important for thorough suppression of VZV reactivation.

  4. CTA-enhanced perfusion CT: an original method to perform ultra-low-dose CTA-enhanced perfusion CT

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Elizabeth; Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, Charlottesville, VA (United States)

    2014-11-15

    Utilizing CT angiography enhances image quality in PCT, thereby permitting acquisition at ultra-low dose. Dynamic CT acquisitions were obtained at 80 kVp with decreasing tube current-time product [milliamperes x seconds (mAs)] in patients suspected of ischemic stroke, with concurrent CTA of the cervical and intracranial arteries. By utilizing fast Fourier transformation, high spatial frequencies of CTA were combined with low spatial frequencies of PCT to create a virtual PCT dataset. The real and virtual PCT datasets with decreasing mAs were compared by assessing contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and noise and PCT values and by visual inspection of PCT parametric maps. Virtual PCT attained CNR and SNR three- to sevenfold superior to real PCT and noise reduction by a factor of 4-6 (p < 0.05). At 20 mAs, virtual PCT achieved diagnostic parametric maps, while the quality of real PCT maps was inadequate. At 10 mAs, both real and virtual PCT maps were nondiagnostic. Virtual PCT (but not real PCT) maps regained diagnostic quality at 10 mAs by applying 40 % adaptive statistical iterative reconstruction (ASIR) and improved further with 80 % ASIR. Our new method of creating virtual PCT by combining ultra-low-dose PCT with CTA information yields diagnostic perfusion parametric maps from PCT acquired at 20 or 10 mAs with 80 % ASIR. Effective dose is approximately 0.20 mSv, equivalent to two chest radiographs. (orig.)

  5. Exploring the foundations of physics in solid state systems at ultra-low energy

    Energy Technology Data Exchange (ETDEWEB)

    Prati, Enrico, E-mail: enrico.prati@cnr.it [Laboratorio Materiali e Dispositivi per la Microelettronica, Consiglio Nazionale delle Ricerche - IMM, Via Olivetti 2, 1-20041 Agrate Brianza (Italy)

    2011-07-08

    The emergence of quantum field theory as a coarse grained effective model grounded on a more fundamental level is often conjectured. The hypothesis is based both on the lack of a unified theory capable to consistently include gravity and on the existence of several known classes of low energy effects in which effective properties emerge on a coarse grained level. Solid state physics presents major examples of emergence. Effective properties of electrons and light in solid state media mimic, through both collective and coarse grained properties, some fundamental characteristics attributed to particles and spacetime. Here, three low energy mechanisms of the solid state physics connected to those properties are considered, with a particular attention to the relevant energy scale: zero mass fermions in graphene, asymptotic freedom in semiconductor quantum dots, and effective curvature of space in negative refractive index metamaterials.

  6. StarTram: Ultra Low Cost Launch For Large Space Architectures

    Science.gov (United States)

    Powell, J.; Maise, G.; Paniagua, J.

    2004-02-01

    The StarTram Maglev system can launch hundreds of thousands of tons of cargo per year to orbit (~1000 times present capability) plus many thousands of passengers. The launch cost is only $30/kilogram of cargo, ~ 1/300 th of present cost. Magnetically levitated spacecraft accelerate to >=8 km/see in an evacuated ground tunnel using superconducting (SC) Maglev technology now operating in Japan for high speed trains. No propellant is used; energy from the electrical grid costs $0.50 per kg of launch weight. After reaching orbital speed, the levitated craft ascend in a curving evacuated launch tube that is magnetically levitated above Earth's surface by the repulsion force between SC cables attached to it and an opposing set of SC cables on the surface. The levitation force is 4 tons/meter of tube length at 20 km altitude, and exceeds the tube weight. High strength Kevlar tethers to the ground prevent vertical and lateral motion. Craft enter the atmosphere at 20 km through an open exit that prevents in-leakage of low density air by high speed gas ejectors and an MHD (Magnetic Hydro Dynamic) pump, and coast to apogee, where a small V burn (~500 m/s) establishes orbit. Deceleration as it enters the atmosphere at 20 km is modest, ~1 g. Peak heating is ~5 KW/cm2 for times of a few seconds before the craft reaches space. The technology for StarTram-C now exists, and no breakthroughs in materials are required. Two possible StarTram systems are compared, one for cargo only, and the second for both passengers and cargo.

  7. Enhanced electrical conductivity in polystyrene nanocomposites at ultra-low graphene content.

    Science.gov (United States)

    Qi, Xian-Yong; Yan, Dong; Jiang, Zhiguo; Cao, Ya-Kun; Yu, Zhong-Zhen; Yavari, Fazel; Koratkar, Nikhil

    2011-08-01

    We compared the electrical conductivity of multiwalled-carbon-nanotube/polystyrene and graphene/polystyrene composites. The conductivity of polystyrene increases from ∼6.7 × 10(-14) to ∼3.49 S/m, with an increase in graphene content from ∼0.11 to ∼1.1 vol %. This is ∼2-4 orders of magnitude higher than for multiwalled-carbon-nanotube/polystyrene composites. Furthermore, we show that the conductivity of the graphene/polystyrene system can be significantly enhanced by incorporation of polylactic acid. The volume-exclusion principle forces graphene into the polystyrene-rich regions (selective localization) and generates ∼4.5-fold decrease in its percolation threshold from ∼0.33 to ∼0.075 vol %.

  8. An excimer-based FAIMS detector for detection of ultra-low concentration of explosives

    Science.gov (United States)

    Chistyakov, Alexander A.; Kotkovskii, Gennadii E.; Sychev, Alexey V.; Perederiy, Anatoly N.; Budovich, V. L.; Budovich, D. V.

    2014-05-01

    A new method of explosives detection based on the field asymmetric ion mobility spectrometry (FAIMS) and ionization by an excimer emitter has been developed jointly with a portable detector. The excimer emitter differs from usual UVionizing lamps by mechanism of emitting, energy and spectral characteristics. The developed and applied Ar2-excimer emitter has the working volume of 1 cm3, consuming power 0.6 W, the energy of photons of about 10 eV (λ=126 nm), the FWHM radiation spectrum of 10 nm and emits more than 1016 photon per second that is two orders of magnitude higher than UV-lamp of the same working volume emits. This also exceeds by an order of magnitude the quantity of photons per second for 10-Hz solid state YAG:Nd3+ - laser of 1mJ pulse energy at λ=266 nm that is also used to ionize the analyte. The Ar2-excimer ionizes explosives by direct ionization mechanism and through ionization of organic impurities. The developed Ar2-excimer-based ion source does not require cooling due to low level discharge current of emitter and is able to work with no repair more than 10000 hrs. The developed excimer-based explosives detector can analyze both vapors and traces of explosives. The FAIMS spectra of the basic types of explosives like trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), dinitrotoluene (DNT), cyclotetramethylenetetranitramine (HMX), nitroglycerine (NG), pentaerythritol tetranitrate (PETN) under Ar2-excimer ionization are presented. The detection limit determined for TNT vapors equals 1x10-14 g/cm3, for TNT traces- 100 pg.

  9. Accelerated path integral methods for atomistic simulations at ultra-low temperatures.

    Science.gov (United States)

    Uhl, Felix; Marx, Dominik; Ceriotti, Michele

    2016-08-07

    Path integral methods provide a rigorous and systematically convergent framework to include the quantum mechanical nature of atomic nuclei in the evaluation of the equilibrium properties of molecules, liquids, or solids at finite temperature. Such nuclear quantum effects are often significant for light nuclei already at room temperature, but become crucial at cryogenic temperatures such as those provided by superfluid helium as a solvent. Unfortunately, the cost of converged path integral simulations increases significantly upon lowering the temperature so that the computational burden of simulating matter at the typical superfluid helium temperatures becomes prohibitive. Here we investigate how accelerated path integral techniques based on colored noise generalized Langevin equations, in particular the so-called path integral generalized Langevin equation thermostat (PIGLET) variant, perform in this extreme quantum regime using as an example the quasi-rigid methane molecule and its highly fluxional protonated cousin, CH5 (+). We show that the PIGLET technique gives a speedup of two orders of magnitude in the evaluation of structural observables and quantum kinetic energy at ultralow temperatures. Moreover, we computed the spatial spread of the quantum nuclei in CH4 to illustrate the limits of using such colored noise thermostats close to the many body quantum ground state.

  10. Reactive and inelastic processes in the gas-phase at ultra-low temperatures

    CERN Document Server

    Chastaing, D

    2000-01-01

    This thesis reports the gas-phase kinetic study of reactions between neutral species of astrophysical importance, over a wide range of temperatures, from 295 K down to 15 K. Such extremely low temperatures were provided by the CRESU technique (Cinetique de Reaction en Ecoulement Supersonique Uniforme or Reaction Kinetics in Uniform Supersonic Flow). The kinetics of the reactions of ethynyl radical (C sub 2 H) with oxygen (O sub 2) and unsaturated hydrocarbons (C sub 2 H sub 2 , C sub 2 H sub 4 , C sub 3 H sub 6) has been investigated for the first time down to such extremely low temperatures, using a laser photolysis - chemiluminescence technique. Rate coefficients of the reactions of ground state carbon atom with O sub 2 , NO, C sub 2 H sub 2 , C sub 2 H sub 4 and the two C sub 3 H sub 4 isomers (allene and methyl acetylene) have been measured, using a direct detection technique (laser induced fluorescence). These investigations are of particular interest for the improvement of theoretical models which seek ...

  11. Ultra-low-power carbon nanotube FET-based quaternary logic gates

    Science.gov (United States)

    Sharifi, Fazel; Moaiyeri, Mohammad Hossein; Navi, Keivan; Bagherzadeh, Nader

    2016-09-01

    This paper presents low-power carbon nanotube field-effect transistor (CNTFET)-based quaternary logic circuits. The proposed quaternary circuits are designed based on the CNTFET unique properties, such as the same carrier mobility for N- and P-type devices and also providing desirable threshold voltages by adopting proper diameters for the nanotubes. In addition, no paths exist between supply and ground rails in the steady states of the proposed designs, which eliminates the ON state static current and also the stacking technique is utilised in order to significantly reduce the leakage currents. The results of the simulations, conducted using Synopsys HSPICE with the standard 32 nm CNTFET technology, confirm the significantly lower power consumption, higher energy efficiency and lower sensitivity to process variation of the proposed designs compared to the state-of-the-art quaternary logic circuits. The proposed quaternary logic circuits have on average 92, 99 and 91% less total power, static power and PDP, respectively, compared with the most low-power and energy-efficient CNTFET-based quaternary logic circuits, recently presented in the literature.

  12. Accelerated path integral methods for atomistic simulations at ultra-low temperatures

    Science.gov (United States)

    Uhl, Felix; Marx, Dominik; Ceriotti, Michele

    2016-08-01

    Path integral methods provide a rigorous and systematically convergent framework to include the quantum mechanical nature of atomic nuclei in the evaluation of the equilibrium properties of molecules, liquids, or solids at finite temperature. Such nuclear quantum effects are often significant for light nuclei already at room temperature, but become crucial at cryogenic temperatures such as those provided by superfluid helium as a solvent. Unfortunately, the cost of converged path integral simulations increases significantly upon lowering the temperature so that the computational burden of simulating matter at the typical superfluid helium temperatures becomes prohibitive. Here we investigate how accelerated path integral techniques based on colored noise generalized Langevin equations, in particular the so-called path integral generalized Langevin equation thermostat (PIGLET) variant, perform in this extreme quantum regime using as an example the quasi-rigid methane molecule and its highly fluxional protonated cousin, CH5+. We show that the PIGLET technique gives a speedup of two orders of magnitude in the evaluation of structural observables and quantum kinetic energy at ultralow temperatures. Moreover, we computed the spatial spread of the quantum nuclei in CH4 to illustrate the limits of using such colored noise thermostats close to the many body quantum ground state.

  13. Accelerator Mass Spectrometry Analysis of Ultra-Low-Level 129I in Carrier-Free AgI-AgCl Sputter Targets

    DEFF Research Database (Denmark)

    Liu, Qi; Hou, Xiaolin; Zhou, Weijian;

    2015-01-01

    mass spectrometry (AMS) for accurate determination of ultra-low-level 129I in carrier-free AgI-AgCl sputter targets. Copper instead of aluminum was selected as the suitable sample holder material to avoid the reaction of AgI-AgCl powder with aluminum. Niobium powder was selected as thermally...

  14. Effect of Calcium Treatment on Non-Metallic Inclusions in Ultra-Low Oxygen Steel Refined by High Basicity High Al2O3 Sla

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; WANG Xin-hua; JIANG Min; WANG Wan-jun

    2011-01-01

    The influence of calcium treatment on non-metallic inclusions had been studied when control technology of refining top slag in ladle furnace was used in ultra-low oxygen steelmaking. A sufficient amount aluminium was added to experimental heats for final

  15. Design and Analysis of Double-Gate MOSFETs for Ultra-Low Power Radio Frequency Identification (RFID: Device and Circuit Co-Design

    Directory of Open Access Journals (Sweden)

    Tony T. Kim

    2011-07-01

    Full Text Available Recently, double-gate MOSFETs (DGMOSFETs have been shown to be more optimal for ultra-low power circuit design due to the improved subthreshold slope and the reduced leakage current compared to bulk CMOS. However, DGMOSFETs for subthreshold circuit design have not been much explored in comparison to those for strong inversion-based design. In this paper, various configurations of DGMOSFETs, such as tied/independent gates and symmetric/asymmetric gate oxide thickness are explored for ultra-low power and high efficient radio frequency identification (RFID design. Comparison of bulk CMOS with DGMOSFETs has been conducted in ultra-low power subthreshold digital logic design and rectifier design, emphasizing the scope of the nano-scale DGMOSFET technology for future ultra-low power systems. The DGMOSFET-based subthreshold logic improves energy efficiency by more than 40% compared to the bulk CMOS-based logic at 32 nm. Among the various DGMOSFET configurations for RFID rectifiers, symmetric tied-gate DGMOSFET has the best power conversion efficiency and the lowest power consumption.

  16. Ultra-low reflection porous silicon nanowires for solar cell applications

    KAUST Repository

    Najar, Adel

    2012-01-01

    High density vertically aligned Porous Silicon NanoWires (PSiNWs) were fabricated on silicon substrate using metal assisted chemical etching process. A linear dependency of nanowire length to the etching time was obtained and the change in the growth rate of PSiNWs by increasing etching durations was shown. A typical 2D bright-field TEM image used for volume reconstruction of the sample shows the pores size varying from 10 to 50 nm. Furthermore, reflectivity measurements show that the 35% reflectivity of the starting silicon wafer drops to 0.1% recorded for more than 10 μm long PSiNWs. Models based on cone shape of nanowires located in a circular and rectangular bases were used to calculate the reflectance employing the Transfert Matrix Formalism (TMF) of the PSiNWs layer. Using TMF, the Bruggeman model was used to calculate the refractive index of PSiNWs layer. The calculated reflectance using circular cone shape fits better the measured reflectance for PSiNWs. The remarkable decrease in optical reflectivity indicates that PSiNWs is a good antireflective layer and have a great potential to be utilized in radial or coaxial p-n heterojunction solar cells that could provide orthogonal photon absorption and enhanced carrier collection. ©2012 Optical Society of America.

  17. Coronary computed tomography angiography using ultra-low-dose contrast media: radiation dose and image quality.

    Science.gov (United States)

    Komatsu, Sei; Kamata, Teruaki; Imai, Atsuko; Ohara, Tomoki; Takewa, Mitsuhiko; Ohe, Ryoko; Miyaji, Kazuaki; Yoshida, Junichi; Kodama, Kazuhisa

    2013-08-01

    To analyze the invasiveness and image quality of coronary CT angiography (CCTA) with 80 kV. We enrolled 181 patients with low body weight and low calcium level. Of these, 154 patients were randomly assigned to 1 of 3 groups: 280 HU/80 kV (n = 51); 350 HU/80 kV (n = 51); or 350 HU/120 kV (n = 52). The amount of contrast media (CM) was decided with a CT number-controlling system. Twenty-seven patients were excluded because of an invalid time density curve by timing bolus. The predicted amount of CM, volume CT dose index, dose-length product, effective dose, image noise, and 5-point image quality were measured. The amounts of CM for the 80 kV/280 HU, 80 kV/350 HU, and 120 kV/350 HU groups were 10 ± 4 mL, 15 ± 7 mL, and 30 ± 6 mL, respectively. Although image noise was greater at 80 than 120 kV, there was no significant difference in image quality between 80 kV/350 HU and 120 kV/350 HU (p = 0.390). There was no significant difference in image quality between 80 kV/280 HU and 80 kV/350 HU (4.4 ± 0.7 vs. 4.7 ± 0.4, p = 0.056). The amount of CM and effective dose was lower for 80 kV CCTA than for 120 kV CCTA. CCTA at 80 kV/280 HU may decrease the amount of CM and radiation dose necessary while maintaining image quality.

  18. Effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low dose CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Sun [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Kim, Se Hyung, E-mail: shkim7071@gmail.com [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Im, Jong Pil; Kim, Sang Gyun [Department of Internal Medicine, Seoul National University Hospital (Korea, Republic of); Shin, Cheong-il; Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of)

    2015-04-15

    Highlights: •We assessed the effect of reconstruction algorithms on CAD in ultra-low dose CTC. •30 patients underwent ultra-low dose CTC using 120 and 100 kVp with 10 mAs. •CT was reconstructed with FBP, ASiR and Veo and then, we applied a CAD system. •Per-polyp sensitivity of CAD in ULD CT can be improved with the IR algorithms. •Despite of an increase in the number of FPs with IR, it was still acceptable. -- Abstract: Purpose: To assess the effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low-dose CT colonography (ULD CTC). Materials and methods: IRB approval and informed consents were obtained. Thirty prospectively enrolled patients underwent non-contrast CTC at 120 kVp/10 mAs in supine and 100 kVp/10 mAs in prone positions, followed by same-day colonoscopy. Images were reconstructed with filtered back projection (FBP), 80% adaptive statistical iterative reconstruction (ASIR80), and model-based iterative reconstruction (MBIR). A commercial CAD system was applied and per-polyp sensitivities and numbers of false-positives (FPs) were compared among algorithms. Results: Mean effective radiation dose of CTC was 1.02 mSv. Of 101 polyps detected and removed by colonoscopy, 61 polyps were detected on supine and on prone CTC datasets on consensus unblinded review, resulting in 122 visible polyps (32 polyps <6 mm, 52 6–9.9 mm, and 38 ≥ 10 mm). Per-polyp sensitivity of CAD for all polyps was highest with MBIR (56/122, 45.9%), followed by ASIR80 (54/122, 44.3%) and FBP (43/122, 35.2%), with significant differences between FBP and IR algorithms (P < 0.017). Per-polyp sensitivity for polyps ≥ 10 mm was also higher with MBIR (25/38, 65.8%) and ASIR80 (24/38, 63.2%) than with FBP (20/38, 58.8%), albeit without statistical significance (P > 0.017). Mean number of FPs was significantly different among algorithms (FBP, 1.4; ASIR, 2.1; MBIR, 2.4) (P = 0.011). Conclusion: Although the performance of stand-alone CAD

  19. RCRA (Resource Conservation and Recovery Act of 1976) ground-water monitoring projects for Hanford facilities: Progress report, October 1--December 31, 1988: Volume 1, Text

    Energy Technology Data Exchange (ETDEWEB)

    Fruland, R.M.; Bates, D.J.; Lundgren, R.E.

    1989-04-01

    This report describes the progress of 13 Hanford ground-water monitoring projects for the period October 1 to December 31, 1988. There are 16 individual hazardous waste facilities covered by the 13 ground-water monitoring projects. The Grout Treatment Facility is included in this series of quarterly reports for the first time. The 13 projects discussed in this report were designed according to applicable interim-status ground-water monitoring requirements specified in the Resource Conservation and Recovery Act of 1976 (RCRA). During this quarter, field activities primarily consisted of sampling and analyses, and water-level monitoring. The 200 Areas Low-Level Burial Grounds section includes sediment analyses in addition to ground-water monitoring results. Twelve new wells were installed during the previous quarter: two at the 216-A-29 Ditch, six at the 216-A-10 Crib, and four at the 216-B-3 Pond. Preliminary characterization data for these new wells include drillers' logs and other drilling and site characterization data, and are provided in Volume 2 or on microfiche in the back of Volume 1. 26 refs., 28 figs., 74 tabs.

  20. Using Ray Tracing to Evaluate the Performance of Several Methods for Determining the Ground Range and Refractive Index of Ionospheric Scattering Volumes

    Science.gov (United States)

    Greenwald, R. A.; Frissell, N. A.; de Larquier, S.

    2016-12-01

    In this paper, we evaluate the performance of three methods used by HF radars in the SuperDARN network for determining the ground ranges to ionospheric scattering volumes. Each method uses somewhat different approaches, but the same equivalent-path analysis. We also show that Snell's Law can be added to this analysis to determine the refractive index of each scattering volume and thereby correct Doppler velocity measurements for ionospheric refraction. Two of these methods make their predictions using the group range to the scattering volume and a virtual height model, while the third method uses the group range and the elevation angle each backscattered return. The effectiveness of each of these methods is evaluated using ray tracing analyses through the International Reference Ionosphere. Ray tracings analysis provides determinations of the initial elevation angle, group range, group range, and refractive index of each ionospheric volume that backscatters signals to the radar. The initial or final elevation angle and the group range are used as inputs to the geolocation methods and the ground range and refractive index serve as reference data against which the predictions of the geolocation methods can be evaluated. We find that the methods using virtual height models actually change the initial elevation angle determined from ray tracing to a different elevation angle that is consistent with the virtual height model. Due to this change, predictions of the ground range and refractive index of scattering volumes located with virtual-height models are rarely consistent with the predictions obtained from ray tracing. In contrast, the geolocation method that uses the group range and initial or final elevation angle yields predictions that are in good agreement with ray tracing. Modifications to the equivalent-path analysis are required to obtain consistent predictions of the ground range and refractive index of backscatter from the topside F-layer.

  1. Micro-Mixing Lean-Premix System for Ultra-Low Emission Hydrogen/Syngas Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Erlendur Steinthorsson; Brian Hollon; Adel Mansour

    2010-06-30

    The focus of this project was to develop the next generation of fuel injection technologies for environmentally friendly, hydrogen syngas combustion in gas turbine engines that satisfy DOE's objectives of reducing NOx emissions to 3 ppm. Building on Parker Hannifin's proven Macrolamination technology for liquid fuels, Parker developed a scalable high-performing multi-point injector that utilizes multiple, small mixing cups in place of a single conventional large-scale premixer. Due to the small size, fuel and air mix rapidly within the cups, providing a well-premixed fuel-air mixture at the cup exit in a short time. Detailed studies and experimentation with single-cup micro-mixing injectors were conducted to elucidate the effects of various injector design attributes and operating conditions on combustion efficiency, lean stability and emissions and strategies were developed to mitigate the impact of flashback. In the final phase of the program, a full-scale 1.3-MWth multi-cup injector was built and tested at pressures from 6.9bar (100psi) to 12.4bar (180psi) and flame temperatures up to 2000K (3150 F) using mixtures of hydrogen and natural gas as fuel with nitrogen and carbon dioxide as diluents. The injector operated without flash back on fuel mixtures ranging from 100% natural gas to 100% hydrogen and emissions were shown to be insensitive to combustor pressure. NOx emissions of 3-ppm were achieved at a flame temperature of 1750K (2690 F) when operating on a fuel mixture containing 50% hydrogen and 50% natural gas by volume with 40% nitrogen dilution and 1.5-ppm NOx was achieved at a flame temperature of 1680K (2564 F) using only 10% nitrogen dilution. NOx emissions of 3.5-ppm were demonstrated at a flame temperature of 1730K (2650 F) with only 10% carbon dioxide dilution. Finally, 3.6-ppm NOx emissions were demonstrated at a flame temperature over 1600K (2420 F) when operating on 100% hydrogen fuel with 30% carbon dioxide dilution. Superior

  2. Demonstration Stirling Engine based Micro-CHP with ultra-low emissions

    Energy Technology Data Exchange (ETDEWEB)

    Oeberg, Rolf; Olsson, Fredrik [Carl Bro Energikonsult AB (Sweden); Paalsson, Magnus [Lund Inst. of Technology (Sweden)

    2004-03-01

    This project has been initiated in order to develop a new type of natural gas fired low emission combustion system for a Stirling engine CHP-unit, and to demonstrate and evaluate the unit with the newly developed combustion system in a CHP application. The Stirling engine technology is well developed, but mostly used in special applications and CHP-applications are scarce. The very low exhaust emissions with the new combustion system would make the Stirling engine very suitable for installation in as a CHP-unit in domestic areas. The Stirling engine used in the project has been a V161 engine produced by Solo Kleinmotoren GmbH in Sindelfingen. The unit has a nominal output of 7,5 kW{sub el} and 20 kW{sub heat} (Hot water). The new combustion system was developed at Lund University and the very strict emission targets that were set up could be achieved, both in the laboratory tests and during the site-testing period. Typical performance and emission figures measured at the site installation are: Generator output (kW): 7,3; Hot water output (kW): 15; El. efficiency (%): 25,4; Total efficiency (%): 77,8; NO{sub x} (ppm): 14; CO (ppm): 112; HC (ppm): < 1; O{sub 2} (%): 8,0; Noise level 1 m from the unit (dBA): 83. The NO{sub x} emissions were reduced with almost 97 % as compared to a standard Stirling combustion system. The emission figures are considerably lower than what could be achieved in an internal combustion engine of similar size with an oxidation catalyst (report SGC 106), while the performance figures are similar for the two technologies. The site testing was carried out during a period of 1,5 year at a site owned by Goeteborg Energi. The site comprises a building structure with workshops, offices etc. covering a ground area of 2,500 m{sup 2}. A gas fired boiler with an output of 250 kW supplies hot water to a local grid for heating and tap water. The annual heat demand is typically 285 MWh and the hot water temperatures are normally 60-80 deg C. The site

  3. Ultra-low-cost 3D gaze estimation: an intuitive high information throughput compliment to direct brain-machine interfaces.

    Science.gov (United States)

    Abbott, W W; Faisal, A A

    2012-08-01

    Eye movements are highly correlated with motor intentions and are often retained by patients with serious motor deficiencies. Despite this, eye tracking is not widely used as control interface for movement in impaired patients due to poor signal interpretation and lack of control flexibility. We propose that tracking the gaze position in 3D rather than 2D provides a considerably richer signal for human machine interfaces by allowing direct interaction with the environment rather than via computer displays. We demonstrate here that by using mass-produced video-game hardware, it is possible to produce an ultra-low-cost binocular eye-tracker with comparable performance to commercial systems, yet 800 times cheaper. Our head-mounted system has 30 USD material costs and operates at over 120 Hz sampling rate with a 0.5-1 degree of visual angle resolution. We perform 2D and 3D gaze estimation, controlling a real-time volumetric cursor essential for driving complex user interfaces. Our approach yields an information throughput of 43 bits s(-1), more than ten times that of invasive and semi-invasive brain-machine interfaces (BMIs) that are vastly more expensive. Unlike many BMIs our system yields effective real-time closed loop control of devices (10 ms latency), after just ten minutes of training, which we demonstrate through a novel BMI benchmark--the control of the video arcade game 'Pong'.

  4. An ultra low-noise AC beam transformer and digital signal processing system for CERN's ELENA ring

    CERN Document Server

    Angoletta, M E; Caspers, F; Federmann, S; Molendijk, J; Pedersen, F; Sanchez-Quesada, J

    2013-01-01

    CERN’s Extra Low ENergy Antiproton (ELENA) ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator (AD). Essential longitudinal diagnostics required for commissioning and operation include the intensity measurement for bunched and debunched beams and the measurement of p/p for debunched beams to assess the electron cooling performance. The beam phase information is also needed by the Low-Level RF (LLRF) system. The baseline system for providing the required beam parameters and signals is based upon two ultra-low-noise AC beam transformers and associated digital signal processing. The AC beam transformers cover different frequency regions and are an adaptation to the ELENA layout of those used in the AD. Two AC beam transformers will also be installed in the extraction lines to provide beam intensity measurements. The digital signal processing will be carried out with the leadingedge hardware family used for ELENA’s L...

  5. Ultra-Low Level Detection of L-Histidine Using Solution-Processed ZnO Nanorod on Flexible Substrate.

    Science.gov (United States)

    Sasmal, Milan; Maiti, Tapas Kumar; Bhattacharyya, Tarun Kanti

    2015-09-01

    This work demonstrates a novel label free and sensitive approach for the detection of L-histidine. This is a simple and reliable method for ultra-low level detection of L-histidine. All solution processed synthesizing technique was utilized to develop such type of detection scheme. Silicon substrate was replaced by normal transparent sheet to make it more facile and cost-effective detection technique. Fabricated device for L-histidine detection works upon the variation of current through the ZnO nanorod with L-histidine concentration. Operation principle strongly depends upon the electron charge transfer between metal cation and L-histidine inside the chelating complex. Morphological, structural and optical characterization of solution processed synthesized ZnO nanorod (ZnO NR) was carried out prior to sensor device fabrication. Our sensor device exhibits the sensitivity around 0.86 nA/fM and lower limit of detection (LOD) ∼ 0.1 fM(S/N=3).

  6. Design of a birefringent Michelson interferometer-based interleaver with ultra-low dispersion and low cost.

    Science.gov (United States)

    Hu, Haocheng; Zheng, Baozhong; Liu, Qingming; Li, Yang; Wu, Li; Gu, Shijie

    2011-11-21

    We design and demonstrate a birefringent Michelson interferometer based interleaver with ultra-low dispersion and low cost. The interleaver consists of polarizing beam splitters (PBS's) and quarter-wave plates and half-wave plates. The PBS's based Michelson interferometers provide the optical path difference for interference between the two orthogonal polarization components and the half-wave plates provide the birefringent needed to minimize ripple of output. The designed interleaver with two-stage interferometer in a 50 GHz channel spacing application exhibits a 0.5 dB passband and a 25 dB stopband both 27 GHz; a channel isolation higher than 35 dB and chromatic dispersion less than ±5 ps/nm within 0.5 dB passband; 1.3 dB insertion loss and 0.3 dB PDL; 0.04 GHz/°C thermal stability. Since all of the optical components can be optically bonded together, the device is robust and easy to be aligned, which reduces labor cost.

  7. Ultra low-power transceiver with novel FSK modulation technique and efficient FSK-to-ASK demodulation.

    Science.gov (United States)

    Zgaren, Mohamed; Moradi, Arash; Sawan, Mohamad

    2015-01-01

    Energy-efficient and high-data rate are desired in biomedical devices transceivers. A high-performance transmitter (Tx) and an ultra-low-power receiver (Rx) dedicated to medical implants communications operating at Industrial, Scientific and Medical (ISM) frequency band are presented. Tx benefits from a new efficient Frequency-Shift Keying (FSK) modulation technique which provides up to 20 Mb/s of data-rate and consumes only 0.084 nJ/b validated through fabrication. The receiver consists of an FSK-to-ASK conversion based receiver with OOK fully passive wake-up device (WuRx). This WuRx is battery less with energy harvesting technique which plays an important role in making the RF transceiver energy-efficient. The Rx is achieved with a reduced hardware architecture which does not use an accurate local oscillator, high-Q external inductor and I/Q signal path. The Rx shows -78 dBm sensitivity for 8 Mbps data rate while consuming 639 μW. The proposed circuits are implemented in IBM 0.13 μm CMOS technology with 1.2 V supply voltage.

  8. A Design Report of the Baseline for PEP-X: an Ultra-Low Emittance Storage Ring

    Energy Technology Data Exchange (ETDEWEB)

    Bane, Karl; Bertsche, Kirk; Cai, Yunhai; Chao, Alex; Corbett, Willian; Fox, John; Hettel, Robert; Huang, Xiaobiao; Huang, Zhirong; Ng, Cho-Kuen; Nosochkov, Yuri; Novokhatski, Sasha; Radedeau, Thomas; Raubenheimer, Tor; Rivetta, Claudio; Safranek, James; Seeman, John; Stohr, Joachim; Stupakov, Gennady; Wang, Lanfa; Wang, Min-Huey; /SLAC

    2010-06-02

    Over the past year, we have worked out a baseline design for PEP-X, as an ultra-low emittance storage ring that could reside in the existing 2.2-km PEPII tunnel. The design features a hybrid lattice with double bend achromat (DBA) cells in two arcs and theoretical minimum emittance (TME) cells in the remaining four arcs. Damping wigglers are used to reduce the horizontal emittance to 86 pm-rad at zero current for a 4.5 GeV electron beam. At a design current of 1.5 A, the horizontal emittance increases, due to intrabeam scattering, to 164 pm-rad when the vertical emittance is maintained at a diffraction limited 8 pm-rad. The baseline design will produce photon beams achieving a brightness of 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV in a 3.5-m conventional planar undulator. Our study shows that an optimized lattice has adequate dynamic aperture, while accommodating a conventional off-axis injection system. In this report, we present the results of study, including the lattice properties, nonlinear dynamics, intra-beam scattering and Touschek lifetime, RF system, and collective instabilities. Finally, we discuss the possibility of partial lasing at soft X-ray wavelengths using a long undulator in a straight section.

  9. Sustainable self-healing at ultra-low temperatures in structural composites incorporating hollow vessels and heating elements

    Science.gov (United States)

    Wang, Yongjing; Pham, Duc Truong; Zhang, Zhichun; Li, Jinjun; Ji, Chunqian; Liu, Yanju; Leng, Jinsong

    2016-09-01

    Self-healing composites are able to restore their properties automatically. Impressive healing efficiencies can be achieved when conditions are favourable. On the other hand, healing might not be possible under adverse circumstances such as very low ambient temperature. Here, we report a structural composite able to maintain its temperature to provide a sustainable self-healing capability-similar to that in the natural world where some animals keep a constant body temperature to allow enzymes to stay active. The composite embeds three-dimensional hollow vessels with the purpose of delivering and releasing healing agents, and a porous conductive element to provide heat internally to defrost and promote healing reactions. A healing efficiency over 100% at around -60°C was obtained. The effects of the sheets on the interlaminar and tensile properties have been investigated experimentally. The proposed technique can be implemented in a majority of extrinsic self-healing composites to enable automatic recovery at ultra-low temperatures.

  10. Energy Efficiency of Ultra-Low-Power Bicycle Wireless Sensor Networks Based on a Combination of Power Reduction Techniques

    Directory of Open Access Journals (Sweden)

    Sadik Kamel Gharghan

    2016-01-01

    Full Text Available In most wireless sensor network (WSN applications, the sensor nodes (SNs are battery powered and the amount of energy consumed by the nodes in the network determines the network lifespan. For future Internet of Things (IoT applications, reducing energy consumption of SNs has become mandatory. In this paper, an ultra-low-power nRF24L01 wireless protocol is considered for a bicycle WSN. The power consumption of the mobile node on the cycle track was modified by combining adjustable data rate, sleep/wake, and transmission power control (TPC based on two algorithms. The first algorithm was a TPC-based distance estimation, which adopted a novel hybrid particle swarm optimization-artificial neural network (PSO-ANN using the received signal strength indicator (RSSI, while the second algorithm was a novel TPC-based accelerometer using inclination angle of the bicycle on the cycle track. Based on the second algorithm, the power consumption of the mobile and master nodes can be improved compared with the first algorithm and constant transmitted power level. In addition, an analytical model is derived to correlate the power consumption and data rate of the mobile node. The results indicate that the power savings based on the two algorithms outperformed the conventional operation (i.e., without power reduction algorithm by 78%.

  11. Detection of soft-tissue and skeletal infections with ultra low-field (0. 02 T) MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hovi, I.; Hekali, P.; Korhola, O.; Valtonen, M.; Valtonen, V.; Taavitsainen, M.; Kivisaari, A.; Hopfner-Hallikainen, D.; Raininko, R.; Porkka, L.; Sepponen, R.; Suramo, I. (Helsinki Univ. Central Hospital (Finland). Dept. of Diagnostic Radiology Helsinki Univ. Central Hospital (Finland). Dept. of Medicine 2 Helsinki Univ. Central Hospital (Finland). Dept. of Medicine 3)

    To evaluate the use of ultra low-field (0.02 T) magnetic resonance (MR) imaging in the diagnosis of musculoskeletal infection, MR examinations with T2 weighted sequences were performed in 61 patients thought to be suffering from one of four major diagnostic categories: Soft-tissue abscesses (n=22), osteomyelitis (n=21), septic arthritis (n=9) and spondylitis (n=9). Infection was confirmed for 37 of these 61 patients. The verified abscesses, arthritis, spondylitis and acute osteomyelitis could be detected by 0.02 T MR. The sensitivity was poor in cases of chronic osteomyelitis. There was one false positive finding in a patient with a possible soft tissue infection. The 0.02 T MR examination failed four times. Two patients were too heavy and another 2 patients had magnetic material in or near the scanning field. Compared with computed tomography and isotope scanning, 0.02 T MR proved a little more informative, but without any statistical significance. (orig.).

  12. Performance optimization of nanoscale junctionless transistors through varying device design parameters for ultra-low power logic applications

    Science.gov (United States)

    Roy, Debapriya; Biswas, Abhijit

    2016-09-01

    Ultra-low power logic applications at advanced CMOS technology nodes have been extensively investigated nowadays to increase packing density in Integrated Circuits at a lower cost. Junctionless (JL) transistors have emerged as promising alternatives to conventional MOSFETs because of their relatively easy fabrication steps and extreme scalability. We perform a detailed numerical study to evaluate the effects of channel doping concentration, dielectric constant of underlap spacers, source/drain resistance on logic performance of 20 nm gate length JL MOSFETs in terms of ON-current at a given OFF-current, subthreshold swing, gate capacitance and intrinsic delay for supply voltages ranging 0.4-0.75 V. In comparison with the reported experimental data for inversion-mode device, our optimized JL device exhibits enhancement of ION by 15.6%, reduction of drain-induced barrier lowering (DIBL) by 22.5% while preserving equally low SS of 61.5 mV/decade at channel length of 34 nm and supply voltage of 0.75 V.

  13. Optics Design and Performance of an Ultra-Low Emittance Damping Ring for the Compact Linear Collider

    CERN Document Server

    Korostelev, M S

    2006-01-01

    A high-energy (0.5-3.0 TeV centre of mass) electron-positron Compact Linear Collider (CLIC) is being studied at CERN as a new physics facility. The design study has been optimized for 3 TeV centre-of-mass energy. Intense bunches injected into the main linac must have unprecedentedly small emittances to achieve the design luminosity 1035cm-2s-1 required for the physics experiments. The positron and electron bunch trains will be provided by the CLIC injection complex. This thesis describes an optics design and performance of a positron damping ring developed for producing such ultra-low emittance beam. The linear optics of the CLIC damping ring is optimized by taking into account the combined action of radiation damping, quantum excitation and intrabeam scattering. The required beam emittance is obtained by using a TME (Theoretical Minimum Emittance) lattice with compact arcs and short period wiggler magnets located in dispersionfree regions. The damping ring beam energy is chosen as 2.42 GeV. The lattice featu...

  14. Ultra-low vibration pulse-tube cryocooler stabilized cryogenic sapphire oscillator with 10^-16 fractional frequency stability

    CERN Document Server

    Hartnett, John G

    2010-01-01

    A low maintenance long-term operational cryogenic sapphire oscillator has been implemented at 11.2 GHz using an ultra-low-vibration cryostat and pulse-tube cryocooler. It is currently the world's most stable microwave oscillator employing a cryocooler. Its performance is explained in terms of temperature and frequency stability. The phase noise and the Allan deviation of frequency fluctuations have been evaluated by comparing it to an ultra-stable liquid-helium cooled cryogenic sapphire oscillator in the same laboratory. Assuming both contribute equally, the Allan deviation evaluated for the cryocooled oscillator is sigma_y = 1 x 10^-15 tau^-1/2 for integration times 1 < tau < 10 s with a minimum sigma_y = 3.9 x 10^-16 at tau = 20 s. The long term frequency drift is less than 5 x 10^-14/day. From the measured power spectral density of phase fluctuations the single side band phase noise can be represented by L_phi(f) = 10^-14.0/f^4+10^-11.6/f^3+10^-10.0/f^2+10^-10.2/f+ 10^-11.0 for Fourier frequencies 10...

  15. Realization of a robust homodyne quadrature laser interferometer by performing wave plate yawing to realize ultra-low error sensitivity.

    Science.gov (United States)

    Cui, Junning; He, Zhangqiang; Tan, Jiubin; Sun, Tao

    2016-10-03

    The deviation of wave plates' optical axes from their intended angles, which may result from either instability or assembly error, is the main cause of quadrature phase error in homodyne quadrature laser interferometers (HQLIs). The quadrature phase error sensitivity to wave plate angle deviations, which is an effective measure of HQLI robustness, is further amplified by beam splitter imperfections. In this paper, a new HQLI design involving non-polarization beam splitting is presented, and a method of making this HQLI robust by yawing the wave plates in the measurement and reference arms is proposed. The theoretical analysis results indicate that ultra-low quadrature phase error sensitivities to wave plate angle deviations can be realized and that non-polarizing beam splitter imperfections can be adequately compensated for. The experimental results demonstrate that the proposed method can reduce the quadrature phase error sensitivity by more than 1 order of magnitude, from a theoretical value of 1.4°/1° to 0.05°/1°.

  16. Ultra-low-cost 3D gaze estimation: an intuitive high information throughput compliment to direct brain-machine interfaces

    Science.gov (United States)

    Abbott, W. W.; Faisal, A. A.

    2012-08-01

    Eye movements are highly correlated with motor intentions and are often retained by patients with serious motor deficiencies. Despite this, eye tracking is not widely used as control interface for movement in impaired patients due to poor signal interpretation and lack of control flexibility. We propose that tracking the gaze position in 3D rather than 2D provides a considerably richer signal for human machine interfaces by allowing direct interaction with the environment rather than via computer displays. We demonstrate here that by using mass-produced video-game hardware, it is possible to produce an ultra-low-cost binocular eye-tracker with comparable performance to commercial systems, yet 800 times cheaper. Our head-mounted system has 30 USD material costs and operates at over 120 Hz sampling rate with a 0.5-1 degree of visual angle resolution. We perform 2D and 3D gaze estimation, controlling a real-time volumetric cursor essential for driving complex user interfaces. Our approach yields an information throughput of 43 bits s-1, more than ten times that of invasive and semi-invasive brain-machine interfaces (BMIs) that are vastly more expensive. Unlike many BMIs our system yields effective real-time closed loop control of devices (10 ms latency), after just ten minutes of training, which we demonstrate through a novel BMI benchmark—the control of the video arcade game ‘Pong’.

  17. SQUID-based systems for co-registration of ultra-low field nuclear magnetic resonance images and magnetoencephalography

    Science.gov (United States)

    Matlashov, A. N.; Burmistrov, E.; Magnelind, P. E.; Schultz, L.; Urbaitis, A. V.; Volegov, P. L.; Yoder, J.; Espy, M. A.

    2012-11-01

    The ability to perform magnetic resonance imaging (MRI) in ultra-low magnetic fields (ULF) of ∼100 μT, using superconducting quantum interference device (SQUID) detection, has enabled a new class of magnetoencephalography (MEG) instrumentation capable of recording both anatomical (via the ULF MRI) and functional (biomagnetic) information about the brain. The combined ULF MRI/MEG instrument allows both structural and functional information to be co-registered to a single coordinate system and acquired in a single device. In this paper we discuss the considerations and challenges required to develop a combined ULF MRI/MEG device, including pulse sequence development, magnetic field generation, SQUID operation in an environment of pulsed pre-polarization, and optimization of pick-up coil geometries for MRI in different noise environments. We also discuss the design of a “hybrid” ULF MRI/MEG system under development in our laboratory that uses SQUID pick-up coils separately optimized for MEG and ULF MRI.

  18. SQUID-based systems for co-registration of ultra-low field nuclear magnetic resonance images and magnetoencephalography

    Energy Technology Data Exchange (ETDEWEB)

    Matlashov, A.N., E-mail: matlach@lanl.gov [Los Alamos National Laboratory, P.O. Box 1663, MS-D454, Los Alamos, NM 87545 (United States); Burmistrov, E.; Magnelind, P.E.; Schultz, L.; Urbaitis, A.V.; Volegov, P.L.; Yoder, J.; Espy, M.A. [Los Alamos National Laboratory, P.O. Box 1663, MS-D454, Los Alamos, NM 87545 (United States)

    2012-11-20

    The ability to perform magnetic resonance imaging (MRI) in ultra-low magnetic fields (ULF) of {approx}100 {mu}T, using superconducting quantum interference device (SQUID) detection, has enabled a new class of magnetoencephalography (MEG) instrumentation capable of recording both anatomical (via the ULF MRI) and functional (biomagnetic) information about the brain. The combined ULF MRI/MEG instrument allows both structural and functional information to be co-registered to a single coordinate system and acquired in a single device. In this paper we discuss the considerations and challenges required to develop a combined ULF MRI/MEG device, including pulse sequence development, magnetic field generation, SQUID operation in an environment of pulsed pre-polarization, and optimization of pick-up coil geometries for MRI in different noise environments. We also discuss the design of a 'hybrid' ULF MRI/MEG system under development in our laboratory that uses SQUID pick-up coils separately optimized for MEG and ULF MRI.

  19. Particulate emissions from a stationary engine fueled with ultra-low-sulfur diesel and waste-cooking-oil-derived biodiesel.

    Science.gov (United States)

    Betha, Raghu; Balasubramanian, Rajasekhar

    2011-10-01

    Stationary diesel engines, especially diesel generators, are increasingly being used in both developing countries and developed countries because of increased power demand. Emissions from such engines can have adverse effects on the environment and public health. In this study, particulate emissions from a domestic stationary diesel generator running on ultra-low-sulfur diesel (ULSD) and biodiesel derived from waste cooking oil were characterized for different load conditions. Results indicated a reduction in particulate matter (PM) mass and number emissions while switching diesel to biodiesel. With increase in engine load, it was observed that particle mass increased, although total particle counts decreased for all the fuels. The reduction in total number concentration at higher loads was, however, dependent on percentage of biodiesel in the diesel-biodiesel blend. For pure biodiesel (B100), the reduction in PM emissions for full load compared to idle mode was around 9%, whereas for ULSD the reduction was 26%. A large fraction of ultrafine particles (UFPs) was found in the emissions from biodiesel compared to ULSD. Nearly 90% of total particle concentration in biodiesel emissions comprised ultrafine particles. Particle peak diameter shifted from a smaller to a lower diameter with increase in biodiesel percentage in the fuel mixture.

  20. Exhaust emissions and fuel properties of partially hydrogenated soybean oil methyl esters blended with ultra low sulfur diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Bryan R. [United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N University St, Peoria, IL 61604 (United States); Williams, Aaron; McCormick, Robert L. [United States Department of Energy, National Renewable Energy Laboratory, ReFUEL Laboratory, 1617 Cole Blvd, Golden, CO 80401 (United States); Haas, Michael J. [United States Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E Mermaid Ln, Wyndmoor, PA 19038 (United States)

    2009-09-15

    Important fuel properties and emission characteristics of blends (20 vol.%) of soybean oil methyl esters (SME) and partially hydrogenated SME (PHSME) in ultra low sulfur diesel fuel (ULSD) were determined and compared with neat ULSD. The following changes were observed for B20 blends of SME and PHSME versus neat ULSD: improved lubricity, higher kinematic viscosity and cetane number, lower sulfur content, and inferior low-temperature properties and oxidative stability. With respect to exhaust emissions, B20 blends of PHSME and SME exhibited lower PM and CO emissions in comparison to those of neat ULSD. The PHSME blend also showed a significant reduction in THC emissions. Both SME and PHSME B20 blends yielded small increases in NO{sub x} emissions. The reduction in double bond content of PHSME did not result in a statistically significant difference in NO{sub x} emissions versus SME at the B20 blend level. The test engine consumed a greater amount of fuel operating on the SME and PHSME blends than on neat ULSD, but the increase was smaller for the PHSME blend. (author)

  1. Criticality features in ultra-low frequency magnetic fields prior to the 2013 M6.3 Kobe earthquake

    Directory of Open Access Journals (Sweden)

    Stelios M. Potirakis

    2016-07-01

    Full Text Available The nonlinear criticality of ultra-low frequency (ULF magnetic variations is investigated before a particular earthquake (EQ occurred in Kobe on April 12, 2013, by applying the “natural time” analysis on a few ULF parameters: Fh, Fz and Dh. The first two refer to radiation from the lithosphere, and the last parameter corresponds to depression of horizontal component as a signature of ionospheric perturbation. A recent paper of our team has indicated, using the same data as in this paper but by means of conventional statistical analysis, a clear effect of depression in the horizontal component as an ionospheric signature. But there seems to be no convincing signature of lithospheric ULF radiation according to the specific analysis, so this paper aims at extending our study on the electromagnetic data recorded prior to the specific EQ by trying to find any significant phenomenon in ULF effects (both lithospheric radiation and the depression of horizontal component using the critical, natural time analysis. The natural time analysis has yielded that criticality at Shigaraki (SGA, as the station closest to the EQ epicenter, is reached on March 27-29 for Fh and March 27 to April 1 for Fz (about two weeks before the EQ. But, the criticality for Dh was not observed at SGA probably due to high noise, on the other hand such criticality was observed at Kanoya (KNY because of its known property of a wider range of detection of ULF depression.

  2. Ultra-Low Voltage Sixth-Order Low Pass Filter for Sensing the T-Wave Signal in ECGs

    Directory of Open Access Journals (Sweden)

    Panagiotis Bertsias

    2014-11-01

    Full Text Available An ultra-low voltage sixth-order low pass filter topology, suitable for sensing the T-wave signal in an electrocardiogram (ECG, is presented in this paper. This is realized using a cascade connection of second-order building blocks constructed from a sinh-domain two-integrator loop. The performance of the filter has been evaluated using the Cadence Analog Design Environment and the design kit provided by the Austria Mikro Systeme (AMS 0.35-µm CMOS process. The power consumption of filters was 7.21 nW, while a total harmonic distortion (THD level of 4% was observed for an input signal of 220 pA. The RMS value of the input referred noise was 0.43 pA, and the simulated value of the dynamic range (DR was 51.1 dB. A comparison with already published counterparts shows that the proposed topology offers the benefits of 0.5-V supply voltage operation and significantly improved power efficiency.

  3. Creation of the first ultra-low gluten barley (Hordeum vulgare L.) for coeliac and gluten-intolerant populations.

    Science.gov (United States)

    Tanner, Gregory J; Blundell, Malcolm J; Colgrave, Michelle L; Howitt, Crispin A

    2016-04-01

    Coeliac disease is a well-defined condition that is estimated to affect approximately 1% of the population worldwide. Noncoeliac gluten sensitivity is a condition that is less well defined, but is estimated to affect up to 10% of the population, and is often self-diagnosed. At present, the only remedy for both conditions is a lifelong gluten-free diet. A gluten-free diet is often expensive, high in fat and low in fibre, which in themselves can lead to adverse health outcomes. Thus, there is an opportunity to use novel plant breeding strategies to develop alternative gluten-free grains. In this work, we describe the breeding and characterization of a novel ultra-low gluten (ULG) barley variety in which the hordein (gluten) content was reduced to below 5 ppm. This was achieved using traditional breeding strategies to combine three recessive alleles, which act independently of each other to lower the hordein content in the parental varieties. The grain of the initial variety was shrunken compared to wild-type barleys. We implemented a breeding strategy to improve the grain size to near wild-type levels and demonstrated that the grains can be malted and brewed successfully. The ULG barley has the potential to provide novel healthy foods and beverages for those who require a gluten-free diet.

  4. Patterning challenges in the fabrication of 12 nm half-pitch dual damascene copper ultra low-k interconnects

    Science.gov (United States)

    Chawla, J. S.; Singh, K. J.; Myers, A.; Michalak, D. J.; Schenker, R.; Jezewski, C.; Krist, B.; Gstrein, F.; Indukuri, T. K.; Yoo, H. J.

    2014-03-01

    Earlier [1, 2] work highlighted an integrated process for electrically functional 12 nm half-pitch copper interconnects in an ultralow-k interlayer dielectric (ILD). In this paper, we focus on understanding and reducing undesired effects such as pattern asymmetry/distortion, and line undulation/ collapse. Key defect modes and possible solution paths are discussed. Line undulation can occur when the ILD feature changes shape under the stress of the sacrificial hard mask(s) (HM) during patterning, resulting in "wavy" instead of straight features. The amount of undulation is directly related to mechanical properties such as elastic modulus, residual stresses of patterned HMs and the ILD, as well as the dimensions and aspect ratio of the features. Line collapse is observed post wet-clean processing when one or more of the following is true - Insufficient ILD mechanical strength, excessive pattern aspect ratio, or non-uniform drying. Pattern asymmetry, or unequal critical dimensions (CD) of trenches defined by the same backbone, is a typical problem encountered during spacer-based pitch division. In pitch quartering (P/4), three different trench widths result from small variations in backbone lithography, spacer CD and etch bias. Symmetric patterning can be achieved through rigorous control of patterning processes like backbone definition, spacer deposition and downstream etches. Plasma-based ash and energetic metal deposition were also observed to degrade patterning fidelity of ultra low-k film, and also need to be closely managed.

  5. Modifications produced by selective inhibitors of cyclooxygenase and ultra low dose aspirin on platelet activity in portal hypertension

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To study the mechanism involved in the potentially beneficial effect of ultra low dose aspirin (ULDA) in prehepatic portal hypertension, rats were pretreated with selective COX 1 or 2 inhibitors (SC-560 or NS-398 respectively), and subsequently injected with ULDA or placebo.METHODS: Portal hypertension was induced by portal vein ligation. Platelet activity was investigated with an in-vivo model of laser induced thrombus production in mesenteric circulation and induced hemorrhagic time (IHT). Platelet aggregation induced by ADP and dosing of prostanoid products 6-keto-PGF1α, TXB2, PGE2 and LTB4 were also performed.RESULTS: The portal hypertensive group receiving a placebo showed a decreased in vivo platelet activity with prolonged IHT, an effect that was normalized by ULDA. SC-560 induced a mild antithrombotic effect in the normal rats, and an unmodified effect of ULDA. NS-398 had a mild prothrombotic action in portal hypertensive rats, similar to ULDA, but inhibited a further effect when ULDA was added. An increased 6-keto-PGF1α was observed in portal hypertensive group that was normalised after ULDA administration. TXA2 level after ULDA, remained unchanged.CONCLUSION: These results suggest that the effect of ULDA on platelet activity in portal hypertensive rats,could act through a COX 2 pathway more than the COX 1,predominant for aspirin at higher doses.

  6. A 12b-control ultra-low-power low-noise SC-VGA for medical ultrasound probes

    Directory of Open Access Journals (Sweden)

    Peng Wang

    2013-10-01

    Full Text Available This Letter presents a 12b-control ultra-low-power low-noise two-stage single-ended to differential switched-capacitor variable gain amplifier (SC-VGA for 2–6-MHz second harmonic cardiac imaging ultrasound probes in 0.18 μm complementary metal oxide semiconductor. The proposed SC-VGA consists of inverters and capacitor (CAP arrays. By adopting inverters instead of operational trans-conductance amplifiers (OTAs in traditional SC-amplifiers, both the power and noise are significantly improved. Each stage has a 6b binary-weighted CAP array, and in total the 12b CAP arrays achieve the dB-in-linear gain range from − 21 to 21 dB. The CAP array is divided between the upper 3b and lower 3b by a CAP to decrease the capacitance spread. The total power consumption is 150 μA at 1 V supply voltage, and the input referred noise is 6.5 nV/√HZ at 4 MHz. The second harmonic distortion (HD2 has the mean value − 77 dB at the 460 mV peak-to-peak output swing for 50 samples of Monte Carlo mismatch simulation with a 30 MHz sampling frequency.

  7. Ultra-low vanadium ion diffusion amphoteric ion-exchange membranes for all-vanadium redox flow batteries

    Science.gov (United States)

    Liao, J. B.; Lu, M. Z.; Chu, Y. Q.; Wang, J. L.

    2015-05-01

    An amphoteric ion-exchange membrane (AIEM) from fluoro-methyl sulfonated poly(arylene ether ketone) bearing content-controlled benzimidazole moiety, was firstly fabricated for vanadium redox flow battery (VRB). The AIEM and its covalently cross-linked membrane (AIEM-c) behave the highly suppressed vanadium-ion crossover and their tested VO2+ permeability are about 638 and 1117 times lower than that of Nafion117, respectively. This is further typically verified by the lower VO2+ concentration inside AIEM that is less than half of that inside Nafion117 detected by energy dispersive X-ray spectrometry, in addition of the nearly 3 times longer battery self-discharge time. The ultra-low vanadium ion diffusion could be ascribed to the narrower ion transporting channel originated from the acid-base interactions and the rebelling effect between the positively-charged benzimidazole structure and VO2+ ions. It is found that, VRB assembled with AIEM exhibits the equal or higher Coulombic efficiency (99.0% vs. 96.4%), voltage efficiency (90.7% vs. 90.7%) and energy efficiency (89.8% vs. 87.4%) than that with Nafion117 and keeps continuous 220 charge-discharge cycles for over 25 days, confirming that the AIEM of this type is a potentially suitable separator for VRB application.

  8. Noise Reduction Effect of Multiple-Sampling-Based Signal-Readout Circuits for Ultra-Low Noise CMOS Image Sensors.

    Science.gov (United States)

    Kawahito, Shoji; Seo, Min-Woong

    2016-11-06

    This paper discusses the noise reduction effect of multiple-sampling-based signal readout circuits for implementing ultra-low-noise image sensors. The correlated multiple sampling (CMS) technique has recently become an important technology for high-gain column readout circuits in low-noise CMOS image sensors (CISs). This paper reveals how the column CMS circuits, together with a pixel having a high-conversion-gain charge detector and low-noise transistor, realizes deep sub-electron read noise levels based on the analysis of noise components in the signal readout chain from a pixel to the column analog-to-digital converter (ADC). The noise measurement results of experimental CISs are compared with the noise analysis and the effect of noise reduction to the sampling number is discussed at the deep sub-electron level. Images taken with three CMS gains of two, 16, and 128 show distinct advantage of image contrast for the gain of 128 (noise(median): 0.29 e(-)rms) when compared with the CMS gain of two (2.4 e(-)rms), or 16 (1.1 e(-)rms).

  9. Noise Reduction Effect of Multiple-Sampling-Based Signal-Readout Circuits for Ultra-Low Noise CMOS Image Sensors

    Directory of Open Access Journals (Sweden)

    Shoji Kawahito

    2016-11-01

    Full Text Available This paper discusses the noise reduction effect of multiple-sampling-based signal readout circuits for implementing ultra-low-noise image sensors. The correlated multiple sampling (CMS technique has recently become an important technology for high-gain column readout circuits in low-noise CMOS image sensors (CISs. This paper reveals how the column CMS circuits, together with a pixel having a high-conversion-gain charge detector and low-noise transistor, realizes deep sub-electron read noise levels based on the analysis of noise components in the signal readout chain from a pixel to the column analog-to-digital converter (ADC. The noise measurement results of experimental CISs are compared with the noise analysis and the effect of noise reduction to the sampling number is discussed at the deep sub-electron level. Images taken with three CMS gains of two, 16, and 128 show distinct advantage of image contrast for the gain of 128 (noise(median: 0.29 e−rms when compared with the CMS gain of two (2.4 e−rms, or 16 (1.1 e−rms.

  10. Yield behaviour associated with stacking faults in a high-temperature annealed ultra-low carbon high manganese steel

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Liming [School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 (China); Fan, Likun [Shanghai Research Institute of Materials, 99 Handan Road, Shanghai, 200437 (China); Li, Zhigang; Sun, Nairong [School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 (China); Wang, Huanrong; Wang, Wei [Baosteel Research Institute, 889 Fujin Road, Shanghai, 201900 (China); Shan, Aidang, E-mail: adshan@sjtu.edu.cn [School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 (China)

    2013-10-10

    This paper investigated the tensile behaviour of high-temperature annealed ultra-low carbon high manganese steel with 42 vol% delta-ferrite. The results show that the tensile stress-strain curve of plastic deformation exhibits three distinct stages of deformation: a yielding stage with a remarkably large elongation and a positive strain-hardening rate, a second stage in which the strain-hardening rate rapidly increases, and a third stage in which the strain-hardening rate slowly increase. The yield plateau is intrinsically associated with the increasing formation of strain-induced stacking faults. The stacking faults quickly form during yield deformation, and the yield elongation monotonically increases with the extent of the stacking faults. The localised strain concentration of delta-ferrite and the heterogeneous strain partitioning between harder delta-ferrite and softer austenite play important roles in the rapid formation of stacking faults during strain at the yield plateau, which is an important prerequisite for this yielding phenomenon. The results and analysis demonstrate that the rapid and then slow hardening deformation after the yield plateau result from strain-induced transformation and deformation twinning, respectively.

  11. Ultra Low Frequency (ULF European multi station magnetic field analysis before and during the 2009 earthquake at L'Aquila regarding regional geotechnical information

    Directory of Open Access Journals (Sweden)

    G. Prattes

    2011-07-01

    Full Text Available This work presents ground based Ultra Low Frequency (ULF magnetic field measurements in the frequency range from 10–15 mHz from 1 January 2008 to 14 April 2009. In this time period a strong earthquake series hit the Italian Abruzzo region around L'Aquila with the main stroke of magnitude M = 6.3 on 6 April 2009. In the frame of the South European Geomagnetic Array (SEGMA, a European collaboration runs ULF fluxgate instruments providing continuously magnetic field data recorded in mid- and south Europe. The main scientific objective is the investigation of signal variations due to seismic activity and the discrimination between other natural and human influences. The SEGMA station closest to the L'Aquila earthquake epicenter is L'Aquila observatory located in the epicenter region. For the scientific analysis we extract the nighttime period from 22:00–02:00 UT and determine the power spectral density (PSD of the horizontal (H and vertical (Z magnetic field components and the standardized polarization ratio (Z over (H. To discriminate local emissions from global geomagnetic effects, data from three SEGMA stations in distances up to 630 km from the epicenter region are analyzed and further compared to the independent global geomagnetic ∑ Kp index. Apart from indirect ionospheric effects, electromagnetic noise could be originated in the lithosphere due to tectonic mechanisms in the earthquake focus. To estimate the amplitude of assumed lithospheric electromagnetic noise emissions causing anomalies in the PSD of the (Z component, we consider magnetotelluric calculations of the electric crust conductivity in the L'Aquila region. Results found at L'Aquila observatory are interpreted with respect to the lithosphere electrical conductivity in the local observatory region, the ∑ Kp index, and further in a multi station analysis. Possible seismic related ULF

  12. Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Rezaee, Mohammad, E-mail: Mohammad.Rezaee@USherbrooke.ca; Hunting, Darel J.; Sanche, Léon [Groupe en Sciences des Radiations, Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4 (Canada)

    2014-07-15

    Purpose: The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods: Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by{sup 125}I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results: For a single decay of{sup 125}I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm{sup 3} volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions: Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should

  13. Final programmatic environmental impact statement for the Uranium Mill Tailings Remedial Action Ground Water Project. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-04-01

    The first step in the UMTRA Ground Water Project is the preparation of this programmatic environmental impact statement (PEIS). This document analyzes the potential impacts of four alternatives for conducting the Ground Water Project. One of these alternatives is the proposed action. These alternatives do not address site-specific ground water compliance strategies because the PEIS is a planning document only. It assesses the potential programmatic impacts of conducting the Ground Water Project, provides a method for determining the site-specific ground water compliance strategies, and provides data and information that can be used to prepare site-specific environmental impacts analyses more efficiently. This PEIS differs substantially from a site-specific environmental impact statement because multiple ground water compliance strategies, each with its own set of potential impacts, could be used to implement all the alternatives except the no action alternative. In a traditional environmental impact statement, an impacts analysis leads directly to the defined alternatives. The impacts analysis for implementing alternatives in this PEIS first involves evaluating a ground water compliance strategy or strategies, the use of which will result in site-specific impacts. This PEIS impacts analysis assesses only the potential impacts of the various ground water compliance strategies, then relates them to the alternatives to provide a comparison of impacts.

  14. Preservation at ultra-low temperature of in vitro cultured arbuscular mycorrhizal fungi via encapsulation-drying.

    Science.gov (United States)

    Lalaymia, Ismahen; Cranenbrouck, Sylvie; Draye, Xavier; Declerck, Stéphane

    2012-10-01

    temperature: a fast decrease (∼12°Cmin(-1)) from room temperature (+20°C) to -110°C followed by a slow decrease in temperature (∼1°Cmin(-1)) from -110°C to -130°C, and (5) the direct thawing in a water bath (+35°C). The % PIB was above 70 % for all the isolates and even above 95% for 11 out of the 12 isolates after several months of storage at ultra-low temperature. All the isolates kept their capacity to associate to an excised carrot root in vitro and to reproduce the fungal life cycle with the production of several hundreds to thousands of spores after 2m. This method opens the door for the long-term maintenance at ultra-low temperature of AMF isolates within international repositories.

  15. Resource Conservation and Recovery Act ground-water monitoring projects for Hanford facilities: Progress report for the period July 1 to September 30, 1988: Volume 1, Text

    Energy Technology Data Exchange (ETDEWEB)

    Fruland, R.M.; Bates, D.J.; Lundgren, R.E.

    1989-02-01

    This report describes the progress of 12 Hanford ground-water monitoring projects for the period July 1 to September 30, 1988. During this quarter, field activities at the 300 Area process trenches, the Nonradioactive Dangerous Waste Landfill, the 183-H Solar Evaporation Basins, the 1324-N/NA Surface Impoundment and Percolation Ponds, the 1301-N and 1325-N Liquid Waste Disposal Facilities, and the 216-A-36B Crib consisted of ground-water sampling and analyses, and water-level monitoring. The 200 Area Low-Level Burial Grounds section includes well development data, sediment analysis, and water-level measurements. Ground-water sampling was begun at this site, and results will be included in next quarter's report. Twelve new wells were installed during the quarter, two at the 216-A-29 Ditch, size at the 216-A-10 Crib, and four at the 216-B-3 Pond. Preliminary characterization data for these new wells are included in this report. Driller's logs and other drilling and site characterization data will be provided in the next quarterly report. At the 2101-M Pond, construction was completed on four wells, and initial ground-water samples were taken. The drilling logs, geophysical logging data, and as-built diagrams are included in this report in Volume 2. 19 refs., 24 figs., 39 tabs.

  16. Enzyme-triggered self-assembly of a small molecule: a supramolecular hydrogel with leaf-like structures and an ultra-low minimum gelation concentration

    Energy Technology Data Exchange (ETDEWEB)

    Wang Huaimin; Yang Zhimou [Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ren Chunhua; Wang Ling [College of Pharmacy, Nankai University, Tianjin 300071 (China); Song Zhijian; Chen Xuemei, E-mail: yangzm@nankai.edu.cn [School of Chemical and Materials Engineering, College of Chemical Engineering, Huangshi Institute of Technology, Huangshi 435003 (China)

    2010-06-04

    We report on the use of a phosphatase to assist the formation of leaf-like structures and a supramolecular hydrogel with an ultra-low minimum gelation concentration. The compound can gel water at a minimum gelation concentration of 0.01 wt%, which is the lowest gelation concentration reported up to now. The images obtained by transmission electron microscopy (TEM) reveal the existence of leaf-like structures serving as the matrix of the hydrogels. The stability of the hydrogels was studied and emission spectra were used to get information about the molecular packing in the leaf-like structures. Since lowering the concentration of the gelator decreases the toxicity of the resulting hydrogels, ultra-low concentration gels have potential uses as biocompatible biomaterials for, e.g., cell cultures, tissue engineering, and drug delivery.

  17. A regression-based differential expression detection algorithm for microarray studies with ultra-low sample size.

    Science.gov (United States)

    Vasiliu, Daniel; Clamons, Samuel; McDonough, Molly; Rabe, Brian; Saha, Margaret

    2015-01-01

    Global gene expression analysis using microarrays and, more recently, RNA-seq, has allowed investigators to understand biological processes at a system level. However, the identification of differentially expressed genes in experiments with small sample size, high dimensionality, and high variance remains challenging, limiting the usability of these tens of thousands of publicly available, and possibly many more unpublished, gene expression datasets. We propose a novel variable selection algorithm for ultra-low-n microarray studies using generalized linear model-based variable selection with a penalized binomial regression algorithm called penalized Euclidean distance (PED). Our method uses PED to build a classifier on the experimental data to rank genes by importance. In place of cross-validation, which is required by most similar methods but not reliable for experiments with small sample size, we use a simulation-based approach to additively build a list of differentially expressed genes from the rank-ordered list. Our simulation-based approach maintains a low false discovery rate while maximizing the number of differentially expressed genes identified, a feature critical for downstream pathway analysis. We apply our method to microarray data from an experiment perturbing the Notch signaling pathway in Xenopus laevis embryos. This dataset was chosen because it showed very little differential expression according to limma, a powerful and widely-used method for microarray analysis. Our method was able to detect a significant number of differentially expressed genes in this dataset and suggest future directions for investigation. Our method is easily adaptable for analysis of data from RNA-seq and other global expression experiments with low sample size and high dimensionality.

  18. Ultra-low thermal conductivity on Si/Au multilayer films with metal layer thickness below 8 nm

    Science.gov (United States)

    Hu, Yangsen; Hu, Zhiyu

    2017-10-01

    Nanoscale heat conduction with ultra-low thermal conductivity across metal-nonmetal Si/Au multilayer films has been investigated. Si/Au multilayer films with different Au thickness were prepared by magetron sputtering, of which the multilayer structures were confirmed by grazing incidence small angle X-ray scattering (GISAXS) and field emission scanning electron microscopy (FESEM). Moreover, the cross-plane thermal conductivities of the films deposition were investigated by a differential 3ω method at room temperature. It is possible that we can control thermal transport across multilayer films by constructing ultrathin Au layers. The reduced thermal conductivity (∼0.6 Wm-1K-1) of multilayer films with Au thickness of 1 nm is ∼50% of that with Au thickness above 8 nm and 42% of amorphous Si film (1.44 Wm-1K-1). The result is attributed to the low contribution of phonons to the overall thermal conductivity in ultrathin Au layer (below 8 nm), leading to a relatively high film thermal resistances compare to thicker Au layer due to strong electron-phonon coupling at metal-nonmetal interfaces. Meanwhile, experimental results show excellent agreement with two temperature model over 8 nm but not below 8 nm. It can be found that conventional thermal conducitvity models fail to explain the observed thermal conducitvity tendency as a function of intercalating metal layer thickness. Accordingly, a revised two temperature model (TTM) has been proposed, which shows well agreement with experimental results. The results provide us with more insight about the thermal transport mechanism of the heterogeneous multilayer system, and would give more instruction for next-generation thermoelectric material development.

  19. The use of ultra-low-energy dynamic SIMS in the study of the tarnishing of silver

    Energy Technology Data Exchange (ETDEWEB)

    Dowsett, M.G. [Advanced SIMS Projects, Department of Physics, Warwick University, Warwick, Coventry CV4 7AL (United Kingdom)]. E-mail: m.g.dowsett@warwick.ac.uk; Adriaens, A. [Department of Analytical Chemistry, Ghent University (Belgium); Soares, M. [Swiss National Museum, Zurich (Switzerland); Wouters, H. [Koninklijk Instituut voor het Kunstpatrimonium (Belgium); Palitsin, V.V.N. [Advanced SIMS Projects, Department of Physics, Warwick University, Warwick, Coventry CV4 7AL (United Kingdom); Gibbons, R. [Advanced SIMS Projects, Department of Physics, Warwick University, Warwick, Coventry CV4 7AL (United Kingdom); Morris, R.J.H. [Advanced SIMS Projects, Department of Physics, Warwick University, Warwick, Coventry CV4 7AL (United Kingdom)

    2005-09-15

    This paper describes a new application in cultural heritage and other areas for a highly surface specific analytical technique originally developed for semiconductor research. The technique, ultra-low-energy dynamic secondary ion mass spectrometry (uleSIMS), is microdestructive, but has a sensitivity typically better than 1 atom in 10{sup 6}. It can provide an analysis within the top nm, or the top few {mu}m of a surface, and gives chemical fingerprinting as well as atomic composition information. It is complimentary to other near-surface techniques such as SEM-EDX, XRD and electrochemical methods. Here, we describe the use of uleSIMS with SEM and SEM-EDX in a study of the tarnishing of museum silver. We report on the initial stages in the development of reference surfaces for control experiments, and on the data obtained from a lightly tarnished sterling silver test coupon exposed in a museum environment for 2 years. First results from a study of a XVII c. silver fragment, aimed at detecting differences in the tarnish or coating in different areas are also presented. Overall we show that the surface chemistry of all these surfaces is a complex mixture of that due to corrosion, contaminants deposited by solvents, polish media (in an overlayer which may only be a few nm thick), handling and the environment, as well as particulates - both from the environment and from polishes. However, surfaces with different histories show large variations in their uleSIMS spectra and depth profiles, and we attempt to lay the groundwork for the interpretation of these.

  20. Innovations in Rheometer Controlled-Rate Control Loop Design: Ultra Low Angular Speed Control and New Applications

    Science.gov (United States)

    Schulz, Ulrich; Sierro, Philippe; Nijman, Jint

    2008-07-01

    The design and implementation of an angular speed control loop for a universal rheometer is not a trivial task. The combination of a highly dynamic, very low inertia (drag cup) motor (motor inertia is 10-5 kg m2) with samples which can range in viscosity from 10-3 Pas to 108 Pas, which can be between purely viscous and higly viscoelastic, which can exhibit yield-stresses, etc. asks for a highly adaptive digital control loop. For the HAAKE MARS rotational rheometer a new adaptive control loop was developed which allows the control of angular speeds as low 5×10-9 rad/s and response times a short as 10 ms. The adaptation of the control loop to "difficult" samples is performed by analysing the response of the complete system to a short pre-test. In this paper we will show that the (very) short response times at (very) low angular speeds are not only achieved with ideal samples, but due to the adaptable control loop, also with "difficult" samples. We will show measurement results on "difficult" samples like cosmetic creams and emulsions, a laponite gel, etc. to proof that angular speeds down to 10-4 rad/s are reached within 10 ms to 20 ms and angular speeds down to 10-7 rad/s within 1 s to 2 s. The response times for reaching ultra low angular speeds down to 5×10-9 rad/s are in the order of 10 s to 30 s. With this new control loop it is, for the first time, possible to measure yield stresses by applying a very low constant shear-rate to the sample and measuring the torque response as a function of time.

  1. Dynamical cancellation of pulse-induced transients in a metallic shielded room for ultra-low-field magnetic resonance imaging

    Science.gov (United States)

    Zevenhoven, Koos C. J.; Dong, Hui; Ilmoniemi, Risto J.; Clarke, John

    2015-01-01

    Pulse-induced transients such as eddy currents can cause problems in measurement techniques where a signal is acquired after an applied preparatory pulse. In ultra-low-field magnetic resonance imaging, performed in magnetic fields typically of the order of 100 μT, the signal-to-noise ratio is enhanced in part by prepolarizing the proton spins with a pulse of much larger magnetic field and in part by detecting the signal with a Superconducting QUantum Interference Device (SQUID). The pulse turn-off, however, can induce large eddy currents in the shielded room, producing an inhomogeneous magnetic-field transient that both seriously distorts the spin dynamics and exceeds the range of the SQUID readout. It is essential to reduce this transient substantially before image acquisition. We introduce dynamical cancellation (DynaCan), a technique in which a precisely designed current waveform is applied to a separate coil during the later part and turn off of the polarizing pulse. This waveform, which bears no resemblance to the polarizing pulse, is designed to drive the eddy currents to zero at the precise moment that the polarizing field becomes zero. We present the theory used to optimize the waveform using a detailed computational model with corrections from measured magnetic-field transients. SQUID-based measurements with DynaCan demonstrate a cancellation of 99%. Dynamical cancellation has the great advantage that, for a given system, the cancellation accuracy can be optimized in software. This technique can be applied to both metal and high-permeability alloy shielded rooms, and even to transients other than eddy currents.

  2. Ultra-low loss fully-etched grating couplers for perfectly vertical coupling compatible with DUV lithography tools

    Science.gov (United States)

    Dabos, G.; Pleros, N.; Tsiokos, D.

    2016-03-01

    Hybrid integration of VCSELs onto silicon-on-insulator (SOI) substrates has emerged as an attractive approach for bridging the gap between cost-effective and energy-efficient directly modulated laser sources and silicon-based PICs by leveraging flip-chip (FC) bonding techniques and silicon grating couplers (GCs). In this context, silicon GCs, should comply with the process requirements imposed by the complimentary-metal-oxide-semiconductor manufacturing tools addressing in parallel the challenges originating from the perfectly vertical incidence. Firstly, fully etched GCs compatible with deep-ultraviolet lithography tools offering high coupling efficiencies are imperatively needed to maintain low fabrication cost. Secondly, GC's tolerance to VCSEL bonding misalignment errors is a prerequisite for practical deployment. Finally, a major challenge originating from the perfectly vertical coupling scheme is the minimization of the direct back-reflection to the VCSEL's outgoing facet which may destabilize its operation. Motivated from the above challenges, we used numerical simulation tools to design an ultra-low loss, bidirectional VCSEL-to-SOI optical coupling scheme for either TE or TM polarization, based on low-cost fully etched GCs with a Si-layer of 340 nm without employing bottom reflectors or optimizing the buried-oxide layer. Comprehensive 2D Finite-Difference-Time- Domain simulations have been performed. The reported GC layout remains fully compatible with the back-end-of-line (BEOL) stack associated with the 3D integration technology exploiting all the inter-metal-dielectric (IMD) layers of the CMOS fab. Simulation results predicted for the first time in fully etched structures a coupling efficiency of as low as -0.87 dB at 1548 nm and -1.47 dB at 1560 nm with a minimum direct back-reflection of -27.4 dB and -14.2 dB for TE and TM polarization, respectively.

  3. A regression-based differential expression detection algorithm for microarray studies with ultra-low sample size.

    Directory of Open Access Journals (Sweden)

    Daniel Vasiliu

    Full Text Available Global gene expression analysis using microarrays and, more recently, RNA-seq, has allowed investigators to understand biological processes at a system level. However, the identification of differentially expressed genes in experiments with small sample size, high dimensionality, and high variance remains challenging, limiting the usability of these tens of thousands of publicly available, and possibly many more unpublished, gene expression datasets. We propose a novel variable selection algorithm for ultra-low-n microarray studies using generalized linear model-based variable selection with a penalized binomial regression algorithm called penalized Euclidean distance (PED. Our method uses PED to build a classifier on the experimental data to rank genes by importance. In place of cross-validation, which is required by most similar methods but not reliable for experiments with small sample size, we use a simulation-based approach to additively build a list of differentially expressed genes from the rank-ordered list. Our simulation-based approach maintains a low false discovery rate while maximizing the number of differentially expressed genes identified, a feature critical for downstream pathway analysis. We apply our method to microarray data from an experiment perturbing the Notch signaling pathway in Xenopus laevis embryos. This dataset was chosen because it showed very little differential expression according to limma, a powerful and widely-used method for microarray analysis. Our method was able to detect a significant number of differentially expressed genes in this dataset and suggest future directions for investigation. Our method is easily adaptable for analysis of data from RNA-seq and other global expression experiments with low sample size and high dimensionality.

  4. An advanced phantom study assessing the feasibility of neuronal current imaging by ultra-low-field NMR

    Science.gov (United States)

    Körber, Rainer; Nieminen, Jaakko O.; Höfner, Nora; Jazbinšek, Vojko; Scheer, Hans-Jürgen; Kim, Kiwoong; Burghoff, Martin

    2013-12-01

    In ultra-low-field (ULF) NMR/MRI, a common scheme is to magnetize the sample by a polarizing field of up to hundreds of mT, after which the NMR signal, precessing in a field on the order of several μT, is detected with superconducting quantum interference devices (SQUIDs). In our ULF-NMR system, we polarize with up to 50 mT and deploy a single-stage DC-SQUID current sensor with an integrated input coil which is connected to a wire-wound Nb gradiometer. We developed this system (white noise 0.50 fT/√{Hz}) for assessing the feasibility of imaging neuronal currents by detecting their effect on the ULF-NMR signal. Magnetoencephalography investigations of evoked brain activity showed neuronal dipole moments below 50 nAm. With our instrumentation, we have studied two different approaches for neuronal current imaging. In the so-called DC effect, long-lived neuronal activity shifts the Larmor frequency of the surrounding protons. An alternative strategy is to exploit fast neuronal activity as a tipping pulse. This so-called AC effect requires the proton Larmor frequency to match the frequency of the neuronal activity, which ranges from near-DC to ∼kHz. We emulated neuronal activity by means of a single dipolar source in a physical phantom, consisting of a hollow sphere filled with an aqueous solution of CuSO4 and NaCl. In these phantom studies, with physiologically relevant dipole depths, we determined resolution limits for our set-up for the AC and the DC effect of ∼10 μAm and ∼50 nAm, respectively. Hence, the DC effect appears to be detectable in vivo by current ULF-NMR technology.

  5. Compact, ultra-low vibration, closed-cycle helium recycler for uninterrupted operation of MEG with SQUID magnetometers

    Science.gov (United States)

    Wang, Chao; Sun, Limin; Lichtenwalter, Ben; Zerkle, Brent; Okada, Yoshio

    2016-06-01

    A closed-cycle helium recycler was developed for continuous uninterrupted operation for magnetometer-based whole-head magnetoencephalography (MEG) systems. The recycler consists of a two stage 4 K pulse-tube cryocooler and is mounted on the roof of a magnetically shielded room (MSR). A flexible liquid helium (LHe) return line on the recycler is inserted into the fill port of the MEG system in the MSR through a slotted opening in the ceiling. The helium vapor is captured through a line that returns the gas to the top of the recycler assembly. A high-purity helium gas cylinder connected to the recycler assembly supplies the gas, which, after it is liquefied, increases the level of LHe in the MEG system during the start-up phase. No storage tank for evaporated helium gas nor a helium gas purifier is used. The recycler is capable of liquefying helium with a rate of ∼17 L/d after precooling the MEG system. It has provided a fully maintenance-free operation under computer control for 7 months without refill of helium. Although the recycler is used for single-orientation operation at this initial testing site, it is designed to operate at ±20° orientations, allowing the MEG system to be tilted for supine and reclining positions. Vibration of the recycler is dampened to an ultra-low level by using several vibration isolation methods, which enables uninterrupted operation during MEG measurements. Recyclers similar to this system may be quite useful even for MEG systems with 100% magnetometers.

  6. Experimental verification of a novel MEMS multi-modal vibration energy harvester for ultra-low power remote sensing nodes

    Science.gov (United States)

    Iannacci, J.; Sordo, G.; Serra, E.; Kucera, M.; Schmid, U.

    2015-05-01

    In this work, we discuss the verification and preliminary experimental characterization of a MEMS-based vibration Energy Harvester (EH) design. The device, named Four-Leaf Clover (FLC), is based on a circular-shaped mechanical resonator with four petal-like mass-spring cascaded systems. This solution introduces several mechanical Degrees of Freedom (DOFs), and therefore enables multiple resonant modes and deformation shapes in the vibrations frequency range of interest. The target is to realize a wideband multi-modal EH-MEMS device, that overcomes the typical narrowband working characteristics of standard cantilevered EHs, by ensuring flexible and adaptable power source to ultra-low power electronics for integrated remote sensing nodes (e.g. Wireless Sensor Networks - WSNs) in the Internet of Things (IoT) scenario, aiming to self-powered and energy autonomous smart systems. Finite Element Method simulations of the FLC EH-MEMS show the presence of several resonant modes for vibrations up to 4-5 kHz, and level of converted power up to a few μW at resonance and in closed-loop conditions (i.e. with resistive load). On the other hand, the first experimental tests of FLC fabricated samples, conducted with a Laser Doppler Vibrometer (LDV), proved the presence of several resonant modes, and allowed to validate the accuracy of the FEM modeling method. Such a good accordance holds validity for what concerns the coupled field behavior of the FLC EH-MEMS, as well. Both measurements and simulations performed at 190 Hz (i.e. out of resonance) showed the generation of power in the range of nW (Root Mean Square - RMS values). Further steps of this work will include the experimental characterization in a full range of vibrations, aiming to prove the whole functionality of the FLC EH-MEMS proposed design concept.

  7. Conservation Research and Development/ New Ultra-Low Carbon High Strength Steels with Improved Bake Hardenability for Enhanced Stretch Formability and Dent Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Anthony J. DeArdo; C. Isaac Garcia

    2003-12-15

    Conservation Research and Development/New Ultra-Low Carbon High Strength Steels with Improved Bake Hardenability for Enhanced Stretch Formability and Dent Resistance. The experimental work can be divided into four phases. In each phase, the materials were received or designed, processed and tested, to evaluate the BH increment or response, as a function of compositions and processing conditions. Microstructural characterization by various techniques was performed in order to gain insights into the mechanisms of flow stress increment by bake hardening.

  8. Development and Testing of an Ultra Low Power System-On-Chip (SOC) Platform for Marine Mammal Tags and Passive Acoustic Signal Processing

    Science.gov (United States)

    2014-09-30

    REPORT DATE 30 SEP 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Development and Testing of an Ultra Low...transfer, another bit being pulsed high to indicate the type of data being transferred (piezoelectric or hydrophone), and then the data is streamed from...impedance of the boost converter to extract maximum energy from the ambient source. A Single- inductor multiple output (SIMO) DC-DC converter regulates

  9. Ultra-Low Power High Temperature and Radiation Hard Complementary Metal-Oxide-Semiconductor (CMOS) Silicon-on-Insulator (SOI) Voltage Reference

    OpenAIRE

    El Hafed Boufouss; Francis, Laurent A.; Valeriya Kilchytska; Pierre Gérard; Pascal Simon; Denis Flandre

    2013-01-01

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40–200 °C and for differ...

  10. 超低温薄膜压力传感器的研究%Research of Ultra Low Temperature Thin Film Pressure Sensor

    Institute of Scientific and Technical Information of China (English)

    李小换; 邹其利; 张世名

    2009-01-01

    超低温薄膜压力传感器可用于液氢、液氮、液氧等低温环境的压力测量,目前国内外超低温压力传感器产品的工作温度最低为-200 ℃.文中主要介绍了对超低温薄膜压力传感器的研究,通过薄膜压力传感器设计和工艺技术研究,成功研制出超低温薄膜压力传感器,并在-253(液氢)~+60 ℃温度环境下进行压力传感器静态性能测试,结果表明传感器性能指标优异,实现了超低温薄膜压力传感器技术突破.%Ultra low temperature thin film pressure sensor can be used on low temperature environment pressure measure of liquid hydrogen,liquid nitrogen,liquid oxygen and so on.The product's lowest working temperature is -200 ℃ until now.This article mainly introduce research of ultra low temperature thin film pressure sensor.Through research of thin film pressure sensor designs and techniques research,ultra low temperature thin film pressure sensor was prepared successfully,and the sensor's static performance was tested in -253~+60 ℃ environment.The result indicated that the index of the sensor was well,the techniques of ultra low temperature thin film pressure sensor was archived.

  11. a-SiNx:H-based ultra-low power resistive random access memory with tunable Si dangling bond conduction paths.

    Science.gov (United States)

    Jiang, Xiaofan; Ma, Zhongyuan; Xu, Jun; Chen, Kunji; Xu, Ling; Li, Wei; Huang, Xinfan; Feng, Duan

    2015-10-28

    The realization of ultra-low power Si-based resistive switching memory technology will be a milestone in the development of next generation non-volatile memory. Here we show that a high performance and ultra-low power resistive random access memory (RRAM) based on an Al/a-SiNx:H/p(+)-Si structure can be achieved by tuning the Si dangling bond conduction paths. We reveal the intrinsic relationship between the Si dangling bonds and the N/Si ratio x for the a-SiNx:H films, which ensures that the programming current can be reduced to less than 1 μA by increasing the value of x. Theoretically calculated current-voltage (I-V) curves combined with the temperature dependence of the I-V characteristics confirm that, for the low-resistance state (LRS), the Si dangling bond conduction paths obey the trap-assisted tunneling model. In the high-resistance state (HRS), conduction is dominated by either hopping or Poole-Frenkel (P-F) processes. Our introduction of hydrogen in the a-SiNx:H layer provides a new way to control the Si dangling bond conduction paths, and thus opens up a research field for ultra-low power Si-based RRAM.

  12. Comparative analysis of gas and coal-fired power generation in ultra-low emission condition using life cycle assessment (LCA)

    Science.gov (United States)

    Yin, Libao; Liao, Yanfen; Liu, Guicai; Liu, Zhichao; Yu, Zhaosheng; Guo, Shaode; Ma, Xiaoqian

    2017-05-01

    Energy consumption and pollutant emission of natural gas combined cycle power-generation (NGCC), liquefied natural gas combined cycle power-generation (LNGCC), natural gas combined heat and power generation (CHP) and ultra-supercritical power generation with ultra-low gas emission (USC) were analyzed using life cycle assessment method, pointing out the development opportunity and superiority of gas power generation in the period of coal-fired unit ultra-low emission transformation. The results show that CO2 emission followed the order: USC>LNGCC>NGCC>CHP the resource depletion coefficient of coal-fired power generation was lower than that of gas power generation, and the coal-fired power generation should be the main part of power generation in China; based on sensitivity analysis, improving the generating efficiency or shortening the transportation distance could effectively improve energy saving and emission reduction, especially for the coal-fired units, and improving the generating efficiency had a great significance for achieving the ultra-low gas emission.

  13. a-SiNx:H-based ultra-low power resistive random access memory with tunable Si dangling bond conduction paths

    Science.gov (United States)

    Jiang, Xiaofan; Ma, Zhongyuan; Xu, Jun; Chen, Kunji; Xu, Ling; Li, Wei; Huang, Xinfan; Feng, Duan

    2015-10-01

    The realization of ultra-low power Si-based resistive switching memory technology will be a milestone in the development of next generation non-volatile memory. Here we show that a high performance and ultra-low power resistive random access memory (RRAM) based on an Al/a-SiNx:H/p+-Si structure can be achieved by tuning the Si dangling bond conduction paths. We reveal the intrinsic relationship between the Si dangling bonds and the N/Si ratio x for the a-SiNx:H films, which ensures that the programming current can be reduced to less than 1 μA by increasing the value of x. Theoretically calculated current-voltage (I-V ) curves combined with the temperature dependence of the I-V characteristics confirm that, for the low-resistance state (LRS), the Si dangling bond conduction paths obey the trap-assisted tunneling model. In the high-resistance state (HRS), conduction is dominated by either hopping or Poole-Frenkel (P-F) processes. Our introduction of hydrogen in the a-SiNx:H layer provides a new way to control the Si dangling bond conduction paths, and thus opens up a research field for ultra-low power Si-based RRAM.

  14. Study on Ground Diameter Single Entry Volume Table of Cunninghamia lanceolataPlantation%杉木人工林地径材积表编制方法研究

    Institute of Scientific and Technical Information of China (English)

    苏杰南; 黎良财

    2011-01-01

    Based on the determination of the DBH (D13), ground diameter (D0.1). Height (H) and volume (V) of Cunning-hamia lanceolcta (Lamb.) Hook, artifical forests, the single ground diameter volume table was prepared and compared using multiple model selection V-Da1 and double volume table. The test of the two equation showed that they reached the accuracy requirements in production, therefore could be applied in forest survey and management.%根据杉木[ Cunninghamia lanceolata (Lamb.) Hook.]人工林样木的胸径D1.3地径D0.1、树高H的测定值和立木材积的计算值V,分别采用材积V-地径D0.1多模型选优法和二元材积表导算法编制一元地径材积表,并进行比较.经检验,这两种方法编制的数表均能够满足生产上的精度要求,可以作为林业调查、经营管理的工具数表.

  15. The Triglav Glacier (South-Eastern Alps, Slovenia): Volume Estimation, Internal Characterization and 2000-2013 Temporal Evolution by Means of Ground Penetrating Radar Measurements

    Science.gov (United States)

    Del Gobbo, Costanza; Colucci, Renato R.; Forte, Emanuele; Triglav Čekada, Michaela; Zorn, Matija

    2016-08-01

    It is well known that small glaciers of mid latitudes and especially those located at low altitude respond suddenly to climate changes both on local and global scale. For this reason their monitoring as well as evaluation of their extension and volume is essential. We present a ground penetrating radar (GPR) dataset acquired on September 23 and 24, 2013 on the Triglav glacier to identify layers with different characteristics (snow, firn, ice, debris) within the glacier and to define the extension and volume of the actual ice. Computing integrated and interpolated 3D using the whole GPR dataset, we estimate that at the moment of data acquisition the ice area was 3800 m2 and the ice volume 7400 m3. Its average thickness was 1.95 m while its maximum thickness was slightly more than 5 m. Here we compare the results with a previous GPR survey acquired in 2000. A critical review of the historical data to find the general trend and to forecast a possible evolution is also presented. Between 2000 and 2013, we observed relevant changes in the internal distribution of the different units (snow, firn, ice) and the ice volume reduced from about 35,000 m3 to about 7400 m3. Such result can be achieved only using multiple GPR surveys, which allow not only to assess the volume occupied by a glacial body, but also to image its internal structure and the actual ice volume. In fact, by applying one of the widely used empirical volume-area relations to infer the geometrical parameters of the glacier, a relevant underestimation of ice-loss would be achieved.

  16. Final programmatic environmental impact statement for the uranium mill tailings remedial action ground water project. Volume I

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-10-01

    This programmatic environmental impact statement (PElS) was prepared for the Uranium Mill Tailings Remedial Action (UMTRA) Ground Water Project to comply with the National Environmental Policy Act (NEPA). This PElS provides an analysis of the potential impacts of the alternatives and ground water compliance strategies as well as potential cumulative impacts. On November 8, 1978, Congress enacted the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law, codified at 42 USC §7901 et seq. Congress found that uranium mill tailings " ... may pose a potential and significant radiation health hazard to the public, and that every reasonable effort should be made to provide for stabilization, disposal, and control in a safe, and environmentally sound manner of such tailings in order to prevent or minimize other environmental hazards from such tailings." Congress authorized the Secretary of Energy to designate inactive uranium processing sites for remedial action by the U.S. Department of Energy (DOE). Congress also directed the U.S. Environmental Protection Agency (EPA) to set the standards to be followed by the DOE for this process of stabilization, disposal, and control. On January 5, 1983, EPA published standards (40 CFR Part 192) for the disposal and cleanup of residual radioactive materials. On September 3, 1985, the U.S. Court of Appeals for the Tenth Circuit set aside and remanded to EPA the ground water provisions of the standards. The EPA proposed new standards to replace remanded sections and changed other sections of 40 CFR Part 192. These proposed standards were published in the Federal Register on September 24, 1987 (52 FR 36000). Section 108 of the UMTRCA requires that DOE comply with EPA's proposed standards in the absence of final standards. The Ground Water Project was planned under the proposed standards. On January 11, 1995, EPA published the final rule, with which the DOE must now comply. The PElS and the Ground Water Project are

  17. Space shuttle/food system study. Volume 2, Appendix G: Ground support system analysis. Appendix H: Galley functional details analysis

    Science.gov (United States)

    1974-01-01

    The capabilities for preflight feeding of flight personnel and the supply and control of the space shuttle flight food system were investigated to determine ground support requirements; and the functional details of an onboard food system galley are shown in photographic mockups. The elements which were identified as necessary to the efficient accomplishment of ground support functions include the following: (1) administration; (2) dietetics; (3) analytical laboratories; (4) flight food warehouse; (5) stowage module assembly area; (6) launch site module storage area; (7) alert crew restaurant and disperse crew galleys; (8) ground food warehouse; (9) manufacturing facilities; (10) transport; and (11) computer support. Each element is discussed according to the design criteria of minimum cost, maximum flexibility, reliability, and efficiency consistent with space shuttle requirements. The galley mockup overview illustrates the initial operation configuration, food stowage locations, meal assembly and serving trays, meal preparation configuration, serving, trash management, and the logistics of handling and cleanup equipment.

  18. An Ultra-Low Voltage Analog Front End for Strain Gauge Sensory System Application in 0.18µm CMOS

    Science.gov (United States)

    Edward, Alexander; Chan, Pak Kwong

    This paper presents analysis and design of a new ultra-low voltage analog front end (AFE) dedicated to strain sensor applications. The AFE, designed in 0.18µm CMOS process, features a chopper-stabilized instrumentation amplifier (IA), a balanced active MOSFET-C 2nd order low pass filter (LPF), a clock generator and a voltage booster which operate at supply voltage (Vdd) of 0.6V. The designed IA achieves 30dB of closed-loop gain, 101dB of common-mode rejection ratio (CMRR) at 50Hz, 80dB of power-supply rejection ratio (PSRR) at 50Hz, thermal noise floor of 53.4 nV/√Hz, current consumption of 14µA, and noise efficiency factor (NEF) of 9.7. The high CMRR and rail-to-rail output swing capability is attributed to a new low voltage realization of the active-bootstrapped technique using a pseudo-differential gain-boosting operational transconductance amplifier (OTA) and proposed current-driven bulk (CDB) biasing technique. An output capacitor-less low-dropout regulator (LDO), with a new fast start-up LPF technique, is used to regulate this 0.6V supply from a 0.8-1.0V energy harvesting power source. It achieves power supply rejection (PSR) of 42dB at frequency of 1MHz. A cascode compensated pseudo differential amplifier is used as the filter's building block for low power design. The filter's single-ended-to-balanced converter is implemented using a new low voltage amplifier with two-stage common-mode cancellation. The overall AFE was simulated to have 65.6dB of signal-to-noise ratio (SNR), total harmonic distortion (THD) of less than 0.9% for a 100Hz sinusoidal maximum input signal, bandwidth of 2kHz, and power consumption of 51.2µW. Spectre RF simulations were performed to validate the design using BSIM3V3 transistor models provided by GLOBALFOUNDRIES 0.18µm CMOS process.

  19. A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-06-13

    Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state

  20. Full Useful Life (120,000 miles) Exhaust Emission Performance of a NOx Adsorber and Diesel Particle Filter Equipped Passenger Car and Medium-duty Engine in Conjunction with Ultra Low Sulfur Fuel (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, M.; Tatur, M.; Tomazic, D.; Weber, P.; Webb, C.

    2005-08-25

    Discusses the full useful life exhaust emission performance of a NOx (nitrogen oxides) adsorber and diesel particle filter equipped light-duty and medium-duty engine using ultra low sulfur diesel fuel.

  1. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Volume 1. Guideline approach

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-05-01

    This document was written for the National Low-Level Waste Management Program to provide guidance for managers and site operators who need to select ground-water transport codes for assessing shallow-land burial site performance. The guidance given in this report also serves the needs of applications-oriented users who work under the direction of a manager or site operator. The guidelines are published in two volumes designed to support the needs of users having different technical backgrounds. An executive summary, published separately, gives managers and site operators an overview of the main guideline report. This volume includes specific recommendations for decision-making managers and site operators on how to use these guidelines. The more detailed discussions about the code selection approach are provided. 242 refs., 6 figs.

  2. Effect of High-Temperature Curing Methods on the Compressive Strength Development of Concrete Containing High Volumes of Ground Granulated Blast-Furnace Slag

    Directory of Open Access Journals (Sweden)

    Wonsuk Jung

    2017-01-01

    Full Text Available This paper investigates the effect of the high-temperature curing methods on the compressive strength of concrete containing high volumes of ground granulated blast-furnace slag (GGBS. GGBS was used to replace Portland cement at a replacement ratio of 60% by binder mass. The high-temperature curing parameters used in this study were the delay period, temperature rise, peak temperature (PT, peak period, and temperature down. Test results demonstrate that the compressive strength of the samples with PTs of 65°C and 75°C was about 88% higher than that of the samples with a PT of 55°C after 1 day. According to this investigation, there might be optimum high-temperature curing conditions for preparing a concrete containing high volumes of GGBS, and incorporating GGBS into precast concrete mixes can be a very effective tool in increasing the applicability of this by-product.

  3. Status of Ground-Water Levels and Storage Volume in the Equus Beds Aquifer Near Wichita, Kansas, July 2008

    Science.gov (United States)

    Hansen, Cristi V.

    2009-01-01

    The Equus Beds aquifer in southwestern Harvey County and northwestern Sedgwick County was developed to supply water to the city of Wichita and for irrigation in south-central Kansas. Water-level and storage-volume decreases that began with the development of the aquifer in the 1940s reached record to near-record lows in January 1993. Since 1993, the aquifer has been experiencing higher water levels and a partial recovery of storage volume previously lost during August 1940 to January 1993. Measured water-level changes for August 1940 to July 2008 ranged from a decline of 23.41 feet to a rise of 3.58 feet. The change in storage volume in the study area from August 1940 to July 2008 was a decrease of about 134,000 acre-feet. This represents a recovery of about 121,000 acre-feet, or about 47 percent of the storage volume previously lost between August 1940 and January 1993. The change in storage volume from August 1940 to July 2008 in the central part of the study area, where city pumpage occurs, was a decrease of about 71,200 acre-feet. This represents a recovery of about 82,800 acre-feet, or about 54 percent of the storage volume previously lost between August 1940 and January 1993 in the central part of the study area. The recovery in the central part of the study area probably was greater and more consistently maintained than in the study area as a whole because city pumpage has remained less than pre-1993 levels, whereas agricultural irrigation pumpage has been as much or more than pre-1993 levels in some years.

  4. Monitored Natural Attenuation of Inorganic Contaminants in Ground Water Volume 3 Assessment for Radionuclides IncludingTritium, Radon, Strontium, Technetium, Uranium, Iodine, Radium, Thorium, Cesium, and Plutonium-Americium

    Science.gov (United States)

    The current document represents the third volume of a set of three volumes that address the technical basis and requirements for assessing the potential applicability of MNA as part of a ground-water remedy for plumes with nonradionuclide and/or radionuclide inorganic contamina...

  5. Low energy stage study. Volume 3: Conceptual design, interface analysis, flight and ground operations. [launching space shuttle payloads

    Science.gov (United States)

    1978-01-01

    Low energy conceptual stage designs and adaptations to existing/planned shuttle upper stages were developed and their performance established. Selected propulsion modes and subsystems were used as a basis to develop airborne support equipment (ASE) design concepts. Orbiter installation and integration (both physical and electrical interfaces) were defined. Low energy stages were adapted to the orbiter and ASE interfaces. Selected low energy stages were then used to define and describe typical ground and flight operations.

  6. Ultra low-dose of gadobenate dimeglumine for late gadolinium enhancement (LGE) imaging in acute myocardial infarction: a feasibility study.

    Science.gov (United States)

    Galea, Nicola; Francone, Marco; Zaccagna, Fulvio; Ciolina, Federica; Cannata, David; Algeri, Emanuela; Agati, Luciano; Catalano, Carlo; Carbone, Iacopo

    2014-12-01

    To assess the feasibility of using an ultra-low dose (0.05 mmol/kg of body weight [BW]) of high relaxivity contrast agent for late gadolinium enhancement (LGE) imaging in patients with acute myocardial infarction (AMI). 17 consecutive patients (mean age, 60.1 ± 10.3 years) with ST-segment elevation AMI underwent two randomized cardiac magnetic resonance studies (exam intervals between 24 and 48h) on a 1.5T unit during the first week after the event using gadobenate dimeglumine (Gd-BOPTA) at the dose of 0.1 mmol/kg BW (standard dose or SD group) and 0.05 mmol/kg BW (half dose or HD group). Image quality was qualitatively assessed. Quantitative analysis of LGE were performed by measuring signal intensity (SI), signal-to-noise ratio (SNR) in the infarcted myocardium (IM), non-infarcted myocardium (N-IM) and left ventricular cavity (LVC) in images acquired at 1, 3, 5, 10, 15 and 20 min after administration of Gd-BOPTA using both contrast media protocol. Contrast-to-noise ratio (CNR) between IM and N-IM (CNR IM/N-IM) and between IM and LVC (CNR IM/LVC) were also quantified for each time point. Moreover the extent of infarcted myocardium was measured. 102 LGE images were evaluated for each dose group. Quality score was significantly higher for SD at 1, 15 and 20 min (0.002

  7. Study on ultra-low density bagasse binderless particleboard%轻质无胶蔗渣板的研究

    Institute of Scientific and Technical Information of China (English)

    廖瑞; 徐剑莹; 唐忠荣; 钟柱; 吴新凤; 尤悦

    2015-01-01

    By taking bagasse as the raw material, without using any synthetic resin, but adding a little environmental-friendly additives (organic acid or sugar), a kind of ultra-low density binderless bagasse particleboard was manufactured. The effects of board density, waterrepellent (wax) on physical and mechanical properties and thermal properties of binderless particleboard were studied. By adopting X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), the effects of mixing additives and water repellent on physical and mechanical properties and bonding mechanism of the bagasse boards were also investigated and analyzed. The results show that the thermal conductivity, TS value and MOR value increased with the increases of board density; The crystallinity of cellulose increased after added additives; By adding a small amount water repellent, though the cellulose crystallinity did not change significantly, the intensity of-OH absorption peak decreased, and the TS value decreased significantly; The thermal conductivity of binderless particleboard can meet the requirements of the National Standard LY/T 1718-2007. This study not only enlarged the raw materials sources of board production , but also solved the problem of formaldehyde emission of wood-based panels.%以蔗渣为原料,不采用合成树脂,而是加入少量环保型添加剂(有机酸或糖)压制轻质无胶蔗渣板。探讨了板的密度,以及防水剂的有无对轻质无胶蔗渣板的物理力学性能及热学性能的影响。采用 X 射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)初步分析了加入添加剂、防水剂对板的物理力学性能及胶合机理的影响,结果表明:随着密度增大,板的导热性能,MOR 值和 TS 值上升;加入添加剂后,板的纤维素结晶度增大;加入少量防水剂(石蜡)后,板的纤维素结晶度没有明显变化,—OH 吸收峰强度下降,TS 下降明显;在研究范

  8. Fabrication of very-low-density, high-stiffness carbon fiber/aluminum hybridized composite with ultra-low density and high stiffness (M-11)

    Science.gov (United States)

    Suzuki, Tomoo

    1993-01-01

    Fabrication of a composite material with ultra-low density and high stiffness in microgravity is the objective of the investigation. The composite structure to be obtained is a random three-dimensional array of high modulus, short carbon fibers bonded at contact points by an aluminum alloy coated on the fibers. The material is highly porous and thus has a very low density. The motivation toward the investigation, simulation experiments, choice of the component materials, and on-flight experiment during ballistic trajectory of a NASDA rocket, are described.

  9. Effects of intracerebroventricular administration of ultra low doses of histaminergic drugs on morphine state-dependent memory of passive avoidance in mice.

    Science.gov (United States)

    Khalilzadeh, Azita; Zarrindast, Mohammad-Reza; Djahanguiri, Bijan

    2006-01-06

    The effects of intracerebroventricular (i.c.v.) administration of ultra low doses (ULDs) of histamine, clobenpropit and pyrilamine are studied on morphine state-dependent (STD) memory in mice. Although pre-test administration of different doses of histamine and clobenpropit showed no effect on impairment of memory induced by pre-training morphine, when the above drugs were co-administered with morphine, they inhibited the restoration of memory by morphine. These effects were opposite to microgram doses of the same drugs.

  10. Controllable Ultra Low-k by Via-Typed Air Gap with the Better Design Margin for Logic Devices below 45 nm Node

    Institute of Scientific and Technical Information of China (English)

    CHOI Youn-Ok; KIM Sang-Yong

    2010-01-01

    @@ By changing the air gap to a via-typed air gap,the height of the air gap is reduced up to about 50% compared to the height of the trench-typed air gap.The controllable(1 ≤ k < 2.9)ultra low-k is also easily fabricated by adjusting the space of the via-typed air gap.The via-typed air gap makes the design margin better due to its lower height in the dense and narrow lines.

  11. Chronic ultra-low dose follicle-stimulating hormone regimen for patients with polycystic ovary syndrome: one click, one follicle, one pregnancy.

    Science.gov (United States)

    Orvieto, Raoul; Homburg, Roy

    2009-04-01

    In the present study we demonstrate that using a weekly incremental dose as small as 8.3 IU of FSH in a chronic ultra low-dose step-up protocol for anovulatory polycystic ovary syndrome (PCOS) produces very good clinical results with an excellent safety profile. Although using a significantly lower incremental (16.6% of the initial dose) and total (622 +/- 286 IU) gonadotropin dose, compared with the widely used and accepted low-dose gonadotropins regimen, a clinical pregnancy rate (PR) of almost 30% per started cycle has been achieved with just one twin gestation and no case of even mild ovarian hyperstimulation syndrome (OHSS).

  12. Tandem electroabsorption modulators integrated with DFB laser by ultra-low-pressure selective-area-growth MOCVD for 10 GHz optical short pulse generation

    Science.gov (United States)

    Zhao, Q.; Pan, J. Q.; Zhang, J.; Zhou, G. T.; Wu, J.; Wang, L. F.; Wang, W.

    2005-08-01

    A novel device of tandem MQW EAMs monolithically integrated with a DFB laser is fabricated by an ultra-low-pressure (22 mbar) selective area growth MOCVD technique. Experimental results exhibit superior device characteristics with low threshold of 19 mA, output light power of 4.5 mW, and over 20 dB extinction ratio when coupled to a single mode fibre. Moreover, over 10 GHz modulation bandwidth is developed with a driving voltage of 2 V. Using this sinusoidal voltage driven integrated device, 10 GHz repetition rate pulse with an actual width of 13.7 ps without any compression elements is obtained.

  13. Tandem electro-absorption modulators integrated with DFB laser by ultra-low-pressure selective-area-growth MOCVD for 10 GHz optical short-pulse generation

    Science.gov (United States)

    Zhao, Q.; Pan, J. Q.; Zhang, J.; Zhou, G. T.; Wu, J.; Wang, L. F.; Wang, W.

    2005-11-01

    A novel device of tandem multiple quantum wells (MQWs) electroabsorption modulators (EAMs) monolithically integrated with DFB laser is fabricated by ultra-low-pressure (22 mbar) selective area growth (SAG) MOCVD technique. Experimental results exhibit superior device characteristics with low threshold of 19 mA, output light power of 4.5 mW, and over 20 dB extinction ratio when coupled into a single mode fiber. Moreover, over 10 GHz modulation bandwidth is developed with a driving voltage of 2 V. Using this sinusoidal voltage driven integrated device, 10GHz repetition rate pulse with a width of 13.7 ps without any compression elements is obtained.

  14. Development of an Ultra-Low-Cost Solar Water Heater: Cooperative Research and Development Final Report, CRADA Number CRD-12-487

    Energy Technology Data Exchange (ETDEWEB)

    Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-17

    NREL and RhoTech will collaborate to bring long-lived, ultra-low-cost, high-performance solar water heaters (SWH) to market readiness. An existing RhoTech design uses seam-welded polymer thin films to make an unglazed thermosiphon, and this design will be modified to improve durability through ultraviolet and overheat protection, and to improve performance by adding a glazing to the collector. Two generations of the new glazed systems will be tested in the field, resulting in a robust market-ready SWH design that can be installed for under $1,000 without rebates.

  15. The synthesis of single layers of Ag nanocrystals by ultra-low-energy ion implantation for large-scale plasmonic structures

    Energy Technology Data Exchange (ETDEWEB)

    Carles, R; Farcau, C; Bonafos, C; Benassayag, G; Pecassou, B; Zwick, A, E-mail: robert.carles@cemes.f [Groupe Nanomat-CEMES-CNRS-Universite de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse Cedex 4 (France)

    2009-09-02

    Single layers of silver (Ag) nanoparticles embedded in silica (SiO{sub 2}) have been fabricated by ultra-low-energy ion implantation. The distance between the Ag particles and the free SiO{sub 2} surface is controlled with nanometer precision. Raman scattering and reflectivity measurements strongly correlate to transmission electron microscopy analyses, allowing the use of these non-invasive techniques to monitor structural and dynamical properties. These results open up new opportunities to manipulate electromagnetic near-field interactions on wafer-scale plasmonic devices.

  16. Nuclear Geoplosics Sourcebook. Volume IV. Part I. Empirical Analysis of Ground Motion from Above and Underground Explosions

    Science.gov (United States)

    1979-03-01

    November 10, 1975. IV-1.8 Feynman , R. P., R. B. Leighton, and M. Sands, The Feynman Lectures on Physics, Vol. II, Chapter 39, Addison Wesley, Massachusetts...Event, POR 6400, Sandia Laboratories, March 1971. IV-2.18 Preston, R. G., and V. E. Wheeler , Response of the Line-of-Sight Pipe to Ground Shock in the...Hupmobile Nuclear Effects Test, Lawrence Radiation Laboratory (Unpublished). IV-2.19 Randolph, P. L., R. G. Preston, and V. E. Wheeler , Preliminary

  17. Dispersed and piled woody residues volumes in coastal Douglas-fir cutblocks determined using high-resolution imagery from a UAV and from ground-based surveys.

    Science.gov (United States)

    Trofymow, J. A.; Gougeon, F.

    2015-12-01

    After forest harvest significant amounts of woody residues are left dispersed on site and some subsequently piled and burned. Quantification of residues is required for estimating C budgets, billable waste, harvest efficiency, bioenergy potential and smoke emissions. Trofymow (et al 2014 CJFR) compared remote sensing methods to ground-based waste and residue survey (WRS) methods for residue piles in 4 cutblocks in the Oyster River (OR) area in coastal BC. Compared to geospatial methods using 15cm orthophotos and LiDAR acquired in 2011 by helicopter, the WRS method underestimated pile wood by 30% to 50% while a USFS volume method overestimated pile wood by 50% if site specific packing ratios were not used. A geospatial method was developed in PCI Geomatica to analyze 2-bit images of logs >15cm diameters to determine dispersed wood residues in OR and compare to WRS methods. Across blocks, geospatial and WRS method wood volumes were correlated (R2=0.69), however volumes were 2.5 times larger for the geospatial vs WRS method. Methods for dispersed residues could not be properly compared as individual WRS plots were not georeferenced, only 12 plots were sampled in total, and low-resolution images poorly resolved logs. Thus, a new study in 2 cutblocks in the Northwest Bay (NWB) area acquired 2cm resolution RGB air-photography in 2014-15 using an Aeryon Sky Ranger UAV prior to and after burn pile construction. A total of 57 dispersed WRS plots and 24 WRS pile or accumulation plots were georeferenced and measured. Stero-pairs were used to generate point-clouds for pile bulk volumes. Images processed to 8-bit grey scale are being analyzed with a revised PCI method that better accounts for log overlaps. WRS methods depend on a good sample of plots and accurate determination of stratum (dispersed, roadside, piles, accumulations) areas. Analysis of NWB blocks shows WRS field methods for stratum area differ by 5-20% from that determined using orthophotos. Plot-level wood

  18. Determination of ice thickness, subice topography and ice volume at Glacier No. 1 in Tien Shan, China by ground penetrating radar

    Institute of Scientific and Technical Information of China (English)

    孙波; 张鹏; 焦克勤; 邓新生; 温家洪

    2003-01-01

    We describe a radio-echo sounding (RES) survey for the determination of ice thickness, subglacial topography and ice volume of Glacier No. 1, in Tien Shah,China, using ground-penetrating radar (GPR). Radar data were collected with 100-MHz antennas that were spaced at 4 m with a step size of 8 m. The images produced from radar survey clearly show the continuity of bedrock echoes and the undulation features of the bedrock surface. Radar results show that the maximum ice thickness of Glacier No. 1 is 133 m, the thickness of the east branch of Glacier No. 1 averages at 58.77 m while that of the west branch of Glacier No. 1 averages at 44.84 m. Calculation on ice volume indicates that the ice volume of the east branch of Glacier No. 1 is 51.87 × 106 m3 and that of the west branch of Glacier No. 1 is 20.21 × 106 m3. The amplitude of the undulation of the bedrock surface topography revealed by radar profiles is larger than that of the glacier surface topography, indicating that the surface relief does not directly depend on that of the bedrock undulation in Glacier No. 1, in Tien Shan.

  19. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland: Volume 2, Quality Assurance Project Plan

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, S.; Martino, L.; Patton, T.

    1995-03-01

    J-Field encompasses about 460 acres at the southern end of the Gunpowder Neck Peninsula in the Edgewood Area of APG (Figure 2.1). Since World War II, the Edgewood Area of APG has been used to develop, manufacture, test, and destroy chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). For the purposes of this project, J-Field has been divided into eight geographic areas or facilities that are designated as areas of concern (AOCs): the Toxic Burning Pits (TBP), the White Phosphorus Burning Pits (WPP), the Riot Control Burning Pit (RCP), the Robins Point Demolition Ground (RPDG), the Robins Point Tower Site (RPTS), the South Beach Demolition Ground (SBDG), the South Beach Trench (SBT), and the Prototype Building (PB). The scope of this project is to conduct a remedial investigation/feasibility study (RI/FS) and ecological risk assessment to evaluate the impacts of past disposal activities at the J-Field site. Sampling for the RI will be carried out in three stages (I, II, and III) as detailed in the FSP. A phased approach will be used for the J-Field ecological risk assessment (ERA).

  20. Accelerator mass spectrometry analysis of ultra-low-level (129)I in carrier-free AgI-AgCl sputter targets.

    Science.gov (United States)

    Liu, Qi; Hou, Xiaolin; Zhou, Weijian; Fu, Yunchong

    2015-05-01

    Separation of carrier-free iodine from low-level iodine samples and accurate measurement of ultra-low-level (129)I in microgram iodine target are essential but a bottleneck in geology and environment research using naturally produced (129)I. This article presents a detection technique of accelerator mass spectrometry (AMS) for accurate determination of ultra-low-level (129)I in carrier-free AgI-AgCl sputter targets. Copper instead of aluminum was selected as the suitable sample holder material to avoid the reaction of AgI-AgCl powder with aluminum. Niobium powder was selected as thermally and electrically conductive matrix to be mixed with AgI-AgCl powder, in order to obtain and maintain a stable and high iodine ion current intensity, as well as less memory effect and low background level of (129)I. The most optimal ratio of the Nb matrix to the AgI-AgCl powder was found to be 5:1 by mass. The typical current of (127)I(5+) using AgI-AgCl targets with iodine content from 5 to 80 μg was measured to be 5 to 100 nA. Four-year AMS measurements of the (129)I/(127)I ratios in standards of low iodine content and the machine blanks showed a good repeatability and stability.

  1. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, Gerlig; Schullian, Peter [Medical University of Innsbruck, Department of Radiology, Innsbruck (Austria); Al-Shawaf, Reema; Al-Sadhan, Ra' ed; Al-Ekrish, Asma' a A. [King Saud University, Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, Riyadh (Saudi Arabia); Hoermann, Romed [Medical University of Innsbruck, Division of Clinical and Functional Anatomy, Innsbruck (Austria)

    2017-05-15

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. (orig.)

  2. ULTRA LOW POWER SINGLE EDGE TRIGGERED DELAY FLIP FLOP BASED SHIFT REGISTERS USING 10-NANOMETER CARBON NANO TUBE FIELD EFFECT TRANSISTOR

    Directory of Open Access Journals (Sweden)

    Ravi Thiyagarajan

    2013-01-01

    Full Text Available Carbon Nano Tube Field Effect Transistor is currently considered as promising successor of Metal Oxide Semiconductor Field Effect Transistor. The scaling down of the Metal Oxide Semiconductor device faced serious limits like short channel effect, tunnelling through gate oxide layer, associated leakage currents and power dissipation when its dimension shrink down to 22 nanometer range. Further scaling of Metal Oxide Semiconductor Field Effect Transistor will result in performance degradation. In this study, an ultra low power Single Edge Triggered Delay Flip Flop and shift registers are designed using 10 nanometre Carbon Nano Tube Field Effect Transistor. The Carbon Nano Tube Field Effect Transistor is an efficient device to supplant the current Complementary Metal Oxide Semiconductor technology for its excellent electrical properties. The high electron and hole mobility of semiconductor nano tubes, their compatibility with high k gate dielectrics, enhanced electrostatics, reduced short channel effects and ability to readily form metal ohmic contacts make these miniaturized structures an ideal material for high performance, nanoscale transistors. To evaluate the performance of Ultra low power Single Edge Triggered Delay Flip Flop and shift registers using 10 nanometer Carbon Nano Tube Field Effect Transistor technology, the results are depicted by analyzing average power, delay, power delay product, rise time and fall time using HSPICE at 1GHz operating frequency.

  3. A highly order-structured membrane electrode assembly with vertically aligned carbon nanotubes for ultra-low Pt loading PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zhi Qun; Lim, San Hua; Poh, Chee Kok; Lin, Jianyi [Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, Singapore 627833 (Singapore); Tang, Zhe; Chua, Daniel [Department of Materials Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Xia, Zetao [Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 (Singapore); Luo, Zhiqiang; Shen, Zexiang [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore (Singapore); Shen, Pei Kang [State Key Laboratory of Optoelectronic Materials and Technologies, and Key Laboratory of Low-carbon Chemistry and Energy Conservation of Guangdong Province, School of Physics and Engineering, Sun Yat-sen University, Guangzhou, 510275 (China); Feng, Yuan Ping [Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

    2011-11-15

    A simple method was developed to prepare ultra-low Pt loading membrane electrode assembly (MEA) using vertically aligned carbon nanotubes (VACNTs) as highly ordered catalyst support for PEM fuel cells application. In the method, VACNTs were directly grown on the cheap household aluminum foil by plasma enhanced chemical vapor deposition (PECVD), using Fe/Co bimetallic catalyst. By depositing a Pt thin layer on VACNTs/Al and subsequent hot pressing, Pt/VACNTs can be 100% transferred from Al foil onto polymer electrolyte membrane for the fabrication of MEA. The whole transfer process does not need any chemical removal and destroy membrane. The PEM fuel cell with the MEA fabricated using this method showed an excellent performance with ultra-low Pt loading down to 35 {mu}g cm{sup -2} which was comparable to that of the commercial Pt catalyst on carbon powder with 400 {mu}g cm{sup -2}. To the best of our knowledge, for the first time, we identified that it is possible to substantially reduce the Pt loading one order by application of order-structured electrode based on VACNTs as Pt catalysts support, compared with the traditional random electrode at a comparable performance through experimental and mathematical methods. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan mountains, central Asia, by ground penetrating radar survey

    Indian Academy of Sciences (India)

    Puyu Wang; Zhongqin Li; Shuang Jin; Ping Zhou; Hongbing Yao; Wenbin Wang

    2014-04-01

    The results of radar survey for three times are presented, aiming to determine ice thickness, volume and subglacial topography of Urumqi Glacier No. 1, Tianshan Mountains, central Asia. Results show that the distribution of ice is more in the center and lesser at both ends of the glacier. The bedrock is quite regular with altitudes decreasing towards the ice front, showing the U-shaped subglacial valley. By comparison, typical ice thinning along the centerline of the East Branch of the glacier was 10–18 m for the period 1981–2006, reaching a maximum of ∼30 m at the terminus. The corresponding ice volume was 10296.2 × 104 m3, 8797.9 × 104 m3 and 8115.0 × 104 m3 in 1981, 2001 and 2006, respectively. It has decreased by 21.2% during the past 25 years, which is the direct result of glacier thinning. In the same period, the ice thickness, area and terminus decreased by 12.2%, 10.3%, and 3.6%, respectively. These changes are responses to the regional climatic warming, which show a dramatic increase of 0.6°C (10 a)−1 during the period 1981–2006.

  5. Influence of Carbonation on Fatigue of Concrete with High Volume of Ground Granulated Blast-furnace Slag

    Institute of Scientific and Technical Information of China (English)

    YOU Lushen; JIANG Linhua; CHU Hongqiang

    2015-01-01

    The effect of carbonation on fatigue performance of ground granulated blast-furnace slag concrete was investigated. Based on the static compression tests of carbonated GGBS-concrete, the correlation between carbonation depth and compressive strength was analyzed and an equation between carbonation depth and compressive strength was put forward. Meanwhile, fatigue S-N curves of various carbonation depths were fitted, and the influence of carbonation on fatigue life and strength was studied. Carbonation has a dual effect on the fatigue behavior of GGBS-concrete. A fatigue equation based on the depth of carbonation was established. Also, the probabilistic distribution of fatigue life of carbonated concrete at a given stress level was modeled by the two-parameter Weibull distribution.

  6. Ultra low-dose of gadobenate dimeglumine for late gadolinium enhancement (LGE) imaging in acute myocardial infarction: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Galea, Nicola, E-mail: nicola.galea@uniroma1.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Francone, Marco, E-mail: marco.francone@uniroma1.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Zaccagna, Fulvio, E-mail: f.zaccagna@gmail.com [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Ciolina, Federica, E-mail: federica.ciolina@gmail.com [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Cannata, David, E-mail: davidrum@yahoo.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Algeri, Emanuela, E-mail: emanuela_algeri@yahoo.com [Service de Radiologie et Imagerie Cardiovasculaire, Hôpital Cardiologique, Centre Hospitalier Régional et Universitaire de Lille, Avenue Oscar Lambret, 59037 Lille Cedex (France); Agati, Luciano, E-mail: luciano.agati@uniroma1.it [Department of Cardiovascular, Respiratory, Nephrologic, Anestesiologic and Geriatric Sciences, Sapienza University of Rome, Policlinico Umberto I, Via del Policlinico 165, 00161 Rome, Rome (Italy); and others

    2014-12-15

    Highlights: • We compared two gadolinium dose for late enhancement imaging in acute infarction. • We evaluated image quality both qualitatively and quantitatively. • Low dose regimen is feasible and provides better image quality at 5–10 min delay. • Standard dose warrants better image quality and should be routinely preferred. - Abstract: Purpose: To assess the feasibility of using an ultra-low dose (0.05 mmol/kg of body weight [BW]) of high relaxivity contrast agent for late gadolinium enhancement (LGE) imaging in patients with acute myocardial infarction (AMI). Materials and methods: 17 consecutive patients (mean age, 60.1 ± 10.3 years) with ST-segment elevation AMI underwent two randomized cardiac magnetic resonance studies (exam intervals between 24 and 48 h) on a 1.5 T unit during the first week after the event using gadobenate dimeglumine (Gd-BOPTA) at the dose of 0.1 mmol/kg BW (standard dose or SD group) and 0.05 mmol/kg BW (half dose or HD group). Image quality was qualitatively assessed. Quantitative analysis of LGE were performed by measuring signal intensity (SI), signal-to-noise ratio (SNR) in the infarcted myocardium (IM), non-infarcted myocardium (N-IM) and left ventricular cavity (LVC) in images acquired at 1, 3, 5, 10, 15 and 20 min after administration of Gd-BOPTA using both contrast media protocol. Contrast-to-noise ratio (CNR) between IM and N-IM (CNR IM/N-IM) and between IM and LVC (CNR IM/LVC) were also quantified for each time point. Moreover the extent of infarcted myocardium was measured. Results: 102 LGE images were evaluated for each dose group. Quality score was significantly higher for SD at 1, 15 and 20 min (0.002 < p < 0.046) and for HD at 5 min (p = 0.013). SNR has been higher in the SD group compared to the HD group even though not statistically significant at any time-point for both IM (SD vs. HD: 87.7 ± 73 vs. 65 ± 66; 0.15 < p < 0.38) and N-IM (SD vs. HD: 22 ± 61 vs. 9.9 ± 6.5; 0.09 < p < 0.43). LVC SNR was

  7. Deriving ice thickness, glacier volume and bedrock morphology of the Austre Lov\\'enbreen (Svalbard) using Ground-penetrating Radar

    CERN Document Server

    Saintenoy, Albane; Booth, Adam D; Tolle, F; Bernard, E; Laffly, Dominique; Marlin, C; Griselin, M

    2013-01-01

    The Austre Lov\\'enbreen is a 4.6 km2 glacier on the Archipelago of Svalbard (79 degrees N) that has been surveyed over the last 47 years in order of monitoring in particular the glacier evolution and associated hydrological phenomena in the context of nowadays global warming. A three-week field survey over April 2010 allowed for the acquisition of a dense mesh of Ground-penetrating Radar (GPR) data with an average of 14683 points per km2 (67542 points total) on the glacier surface. The profiles were acquired using a Mala equipment with 100 MHz antennas, towed slowly enough to record on average every 0.3 m, a trace long enough to sound down to 189 m of ice. One profile was repeated with 50 MHz antenna to improve electromagnetic wave propagation depth in scattering media observed in the cirques closest to the slopes. The GPR was coupled to a GPS system to position traces. Each profile has been manually edited using standard GPR data processing including migration, to pick the reflection arrival time from the ic...

  8. Final programmatic environmental impact statement for the uranium mill tailings remedial action ground water project. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-10-01

    Volume II of the programmatic environmental impact statement (PElS) is a comment and response document; it is the collection of the comments received on the draft PElS. The U.S. Department of Energy's (DOE) response to each comment is provided after each comment. If the comment resulted in a change to the PElS, the affected section number of the PElS is provided in the response. Comments 1 through 259 were received at public hearings. The name of the hearing at which the comment was received is listed after each comment. Comments were recorded on flip charts and by notetakers. DOE representatives were present to hear the comments and respond to them. The DOE's written response is provided after each comment. Comments 260 through 576 were received in writing at the hearings, and from various federal, tribal, and state agencies and from individuals during the public comment period. Copies of the written comments follow the comments and responses.

  9. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Field Sampling Plan

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

    1995-03-01

    The Environmental Management Division (EMD) of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland (Figure 1. 1). Since World War II activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). Considerable archival information about J-Field exists as a result of efforts by APG staff to characterize the hazards associated with the site. Contamination of J-Field was first detected during an environmental survey of the Edgewood Area conducted in 1977 and 1978 by the US Army Toxic and Hazardous Materials Agency (USATHAMA) (predecessor to the US Army Environmental Center [AEC]). As part of a subsequent USATHAMA -environmental survey, 11 wells were installed and sampled at J-Field. Contamination at J-Field was also detected during a munitions disposal survey conducted by Princeton Aqua Science in 1983. The Princeton Aqua Science investigation involved the installation and sampling of nine wells and the collection and analysis of surficial and deep composite soil samples. In 1986, a Resource Conservation and Recovery Act (RCRA) permit (MD3-21-002-1355) requiring a basewide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field was issued by the US Environmental Protection Agency (EPA). In 1987, the US Geological Survey (USGS) began a two-phased hydrogeologic assessment in data were collected to model, groundwater flow at J-Field. Soil gas investigations were conducted, several well clusters were installed, a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today.

  10. Silicon on ferroelectic insulator field effect transistor (SOF-FET) a new device for the next generation ultra low power circuits

    Science.gov (United States)

    Es-Sakhi, Azzedin D.

    Field effect transistors (FETs) are the foundation for all electronic circuits and processors. These devices have progressed massively to touch its final steps in sub-nanometer level. Left and right proposals are coming to rescue this progress. Emerging nano-electronic devices (resonant tunneling devices, single-atom transistors, spin devices, Heterojunction Transistors rapid flux quantum devices, carbon nanotubes, and nanowire devices) took a vast share of current scientific research. Non-Si electronic materials like III-V heterostructure, ferroelectric, carbon nanotubes (CNTs), and other nanowire based designs are in developing stage to become the core technology of non-classical CMOS structures. FinFET present the current feasible commercial nanotechnology. The scalability and low power dissipation of this device allowed for an extension of silicon based devices. High short channel effect (SCE) immunity presents its major advantage. Multi-gate structure comes to light to improve the gate electrostatic over the channel. The new structure shows a higher performance that made it the first candidate to substitute the conventional MOSFET. The device also shows a future scalability to continue Moor's Law. Furthermore, the device is compatible with silicon fabrication process. Moreover, the ultra-low-power (ULP) design required a subthreshold slope lower than the thermionic-emission limit of 60mV/ decade (KT/q). This value was unbreakable by the new structure (SOI-FinFET). On the other hand most of the previews proposals show the ability to go beyond this limit. However, those pre-mentioned schemes have publicized a very complicated physics, design difficulties, and process non-compatibility. The objective of this research is to discuss various emerging nano-devices proposed for ultra-low-power designs and their possibilities to replace the silicon devices as the core technology in the future integrated circuit. This thesis proposes a novel design that exploits the

  11. Ultra-low-dose dual-source CT coronary angiography with high pitch: diagnostic yield of a volumetric planning scan and effects on dose reduction and imaging strategy

    Science.gov (United States)

    Hamm, B; Huppertz, A; Lembcke, A

    2015-01-01

    Objective: To evaluate the role of an ultra-low-dose dual-source CT coronary angiography (CTCA) scan with high pitch for delimiting the range of the subsequent standard CTCA scan. Methods: 30 patients with an indication for CTCA were prospectively examined using a two-scan dual-source CTCA protocol (2.0 × 64.0 × 0.6 mm; pitch, 3.4; rotation time of 280 ms; 100 kV): Scan 1 was acquired with one-fifth of the tube current suggested by the automatic exposure control software [CareDose 4D™ (Siemens Healthcare, Erlangen, Germany) using 100 kV and 370 mAs as a reference] with the scan length from the tracheal bifurcation to the diaphragmatic border. Scan 2 was acquired with standard tube current extending with reduced scan length based on Scan 1. Nine central coronary artery segments were analysed qualitatively on both scans. Results: Scan 2 (105.1 ± 10.1 mm) was significantly shorter than Scan 1 (127.0 ± 8.7 mm). Image quality scores were significantly better for Scan 2. However, in 5 of 6 (83%) patients with stenotic coronary artery disease, a stenosis was already detected in Scan 1 and in 13 of 24 (54%) patients with non-stenotic coronary arteries, a stenosis was already excluded by Scan 1. Using Scan 2 as reference, the positive- and negative-predictive value of Scan 1 was 83% (5 of 6 patients) and 100% (13 of 13 patients), respectively. Conclusion: An ultra-low-dose CTCA planning scan enables a reliable scan length reduction of the following standard CTCA scan and allows for correct diagnosis in a substantial proportion of patients. Advances in knowledge: Further dose reductions are possible owing to a change in the individual patient's imaging strategy as a prior ultra-low-dose CTCA scan may already rule out the presence of a stenosis or may lead to a direct transferal to an invasive catheter procedure. PMID:25710210

  12. Exploring New Thermal Fog and Ultra-Low Volume Technologies to Improve Indoor Control of the Dengue Vector, Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    2014-07-01

    Dengue Vector, Aedes aegypti (Diptera: Culicidae) JAMES F. HARWOOD,1,2 MUHAMMAD FAROOQ,1 ALEC G. RICHARDSON,1 CARL W. DOUD,1 JOHN L. PUTNAM,3 DANIEL E...vector, Aedes aegypti (L.), inside human habitations must be performed quickly and efÞciently to reduce the risk of transmission during dengue...e.g.,WHO2009, Bhatt et al. 2013). Dengue is primarily transmitted by Aedes aegypti (L.) in urban endemic regions. Ae. aegypti , which is also a vector

  13. Droplet Sampling of an Oil-Based and Two Water-Based Antievaporant Ultra-Low Volume Insecticide Formulations Using Teflon- and Magnesium Oxide-Coated Slides

    Science.gov (United States)

    2013-01-01

    2317 2nd Avenue W, Palmetto, FL 34221. 3 US Department of Agriculture–Agricultual Re- search Service European Biological Control Laborato- ry, Tsimiski... Culex control in rural and urban environments for the Coachella Valley of California. J Am Mosq Control Assoc 23:190–207. Matthews GA. 1975. Chemicals and...Mark D. Latham , Roberto M. Pereira , and Philip G. Koehler Source: Journal of the American Mosquito Control Association, 29(2):173-176. 2013

  14. A large-scale field trial of ultra-low-volume fenitrothion applied by a portable mist blower for the control of Aedes aegypti*

    Science.gov (United States)

    Pant, C. P.; Mathis, H. L.; Nelson, M. J.; Phanthumachinda, Boonluan

    1974-01-01

    Long-term control of Aedes aegypti, the vector of dengue haemorrhagic fever in Thailand, was obtained by 2 thorough applications of fenitrothion mist applied at a target dosage rate of 0.1 ml per m3 of room space. Perfect control lasted for 6-7 months after treatment and densities were substantially reduced for up to a year after treatment. Recovery of the population was still slow up to almost 16 months after treatment. This degree of control was achieved by the immediate mortalities produced by 2 treatments spaced about 2 weeks apart, the larvicidal effect of the fenitrothion aerosol, and a limited residual effect that prevented oviposition for a period, so that the recovery potential was greatly diminished. It appears that aerosol and mist treatments designed as epidemic control measures can be adapted to long-term preventive control of A. aegypti. However, the equipment used and the method of application require further improvement. PMID:4549492

  15. A large-scale field trial of ultra-low-volume fenitrothion applied by a portable mist blower for the control of Aedes aegypti.

    Science.gov (United States)

    Pant, C P; Mathis, H L; Nelson, M J; Phanthumachinda, B

    1974-01-01

    Long-term control of Aedes aegypti, the vector of dengue haemorrhagic fever in Thailand, was obtained by 2 thorough applications of fenitrothion mist applied at a target dosage rate of 0.1 ml per m(3) of room space. Perfect control lasted for 6-7 months after treatment and densities were substantially reduced for up to a year after treatment. Recovery of the population was still slow up to almost 16 months after treatment. This degree of control was achieved by the immediate mortalities produced by 2 treatments spaced about 2 weeks apart, the larvicidal effect of the fenitrothion aerosol, and a limited residual effect that prevented oviposition for a period, so that the recovery potential was greatly diminished. It appears that aerosol and mist treatments designed as epidemic control measures can be adapted to long-term preventive control of A. aegypti. However, the equipment used and the method of application require further improvement.

  16. Ultra-low threshold avalanche gain from solar-blind photodetector based on graded-band-gap-cubic-MgZnO.

    Science.gov (United States)

    Xie, Xiuhua; Zhang, Zhenzhong; Li, Binghui; Wang, Shuangpeng; Shen, Dezhen

    2015-12-14

    A larger ratio of conduction-band offset to valence-band offset is the unique character for Mg(x)Zn(1-x)O alloys. For this reason, it is feasible to build a quasi-electric forces, caused by the spatial gradient of the conduction edge, exerting on the electrons. In this paper, a novel graded band gap cubic-MgZnO-based solar-blind photodetector is successfully fabricated from Graded-Band-Gap-Cubic-MgZnO/i-MgO/p-Si heterojunction, via changing stoichiometry spatial gradient. Due to quasi-electric fields in non-uniform MgZnO, the multiple carriers are generated under ultra-low threshold bias voltage. The photodetector showed high performance, namely, high responsivity, quantum efficiency, high sensitivity and selectivity towards the solar-blind spectrum, and fast response times.

  17. A wide range ultra-low power Phase-Locked Loop with automatic frequency setting in 130 nm CMOS technology for data serialisation

    Science.gov (United States)

    Firlej, M.; Fiutowski, T.; Idzik, M.; Moroń, J.; Świentek, K.

    2015-12-01

    The design and measurements results of a wide frequency range ultra-low power Phase-Locked Loop (PLL) for applications in readout systems of particle physics detectors are presented. The PLL was fabricated in a 130 nm CMOS technology. To allow the implementation of different data serialisation schemes multiple division factors (6, 8, 10, 16) were implemented in the PLL feedback loop. The main PLL block—VCO works in 16 frequency ranges/modes, switched either manually or automatically. A dedicated automatic frequency mode switching circuit was developed to allow simple frequency tuning. Although the PLL was designed and simulated for a frequency range of 30 MHz-3 GHz, due to the SLVS interface limits, the measurements were done only up to 1.3 GHz. The full PLL functionality was experimentally verified, confirming a very low and frequency scalable power consumption (0.7 mW at 1 GHz).

  18. On the use of mercury as a means of locating background sources in ultra low-background HPGe-detector systems

    Energy Technology Data Exchange (ETDEWEB)

    Hult, M. [European Commission-Joint Research Centre-Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, GB-2440 Geel (Belgium)], E-mail: mikael.hult@ec.europa.eu; Gasparro, J.; Lindahl, P.; Marissens, G.; Fessler, A. [European Commission-Joint Research Centre-Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, GB-2440 Geel (Belgium); Johnston, Peter N. [Applied Physics, Royal Melbourne Institute of Technology, GPO Box 2476V, Melbourne 3001 (Australia)

    2008-06-15

    In low-level gamma-ray spectrometry, it is common to measure large samples in order to obtain low detection limits for the massic activity (in mBq/kg). These samples have significant shielding effects. In order to study whether the background sources in three ultra low-background HPGe detectors were located in the detector or in the shield, Marinelli beakers filled with hyperpure mercury were measured. Although the measurements were hampered by the presence of cosmogenically produced {sup 194}Hg, information regarding the major background location of {sup 40}K, {sup 60}Co, {sup 137}Cs, {sup 210}Pb, {sup 226}Ra, {sup 228}Ra and {sup 228}Th could be obtained.

  19. Ultra-low switching energy and scaling in electric-field-controlled nanoscale magnetic tunnel junctions with high resistance-area product

    Energy Technology Data Exchange (ETDEWEB)

    Grezes, C.; Alzate, J. G.; Cai, X.; Wang, K. L. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Ebrahimi, F.; Khalili Amiri, P. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Inston, Inc., Los Angeles, California 90024 (United States); Katine, J. A. [HGST, Inc., San Jose, California 95135 (United States); Langer, J.; Ocker, B. [Singulus Technologies AG, Kahl am Main 63796 (Germany)

    2016-01-04

    We report electric-field-induced switching with write energies down to 6 fJ/bit for switching times of 0.5 ns, in nanoscale perpendicular magnetic tunnel junctions (MTJs) with high resistance-area product and diameters down to 50 nm. The ultra-low switching energy is made possible by a thick MgO barrier that ensures negligible spin-transfer torque contributions, along with a reduction of the Ohmic dissipation. We find that the switching voltage and time are insensitive to the junction diameter for high-resistance MTJs, a result accounted for by a macrospin model of purely voltage-induced switching. The measured performance enables integration with same-size CMOS transistors in compact memory and logic integrated circuits.

  20. The energy scaling in a side-pumped ultra-low-magnification unstable resonator by employing a compact master oscillator power amplifier

    Science.gov (United States)

    Cho, C. Y.; Huang, Y. P.; Su, K. W.

    2016-10-01

    The energy scaling for a diode-side-pumped passively Q-switched Nd:YAG laser in an ultra-low-magnification unstable convex-concave resonator is investigated. Theoretical analysis and experimental results indicate the fact that the energy scaling is restricted by the increasing of side-pumping sources inside the resonator because of the significant pump-to-mode size mismatching. It is verified that employing the master oscillation power amplifier can effectively enlarge the output pulse energy and improve the beam quality. Up to 60-mJ pulse energy with 17-MW peak power is obtained at a pump energy of 520 mJ. A 1573-nm eye-safe laser emission with pulse energy up to 25 mJ is further attended via the extracavity optical parametric oscillator.