45 CFR 158.210 - Minimum medical loss ratio.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 1 2012-10-01 2012-10-01 false Minimum medical loss ratio. 158.210 Section 158.210 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS... § 158.210 Minimum medical loss ratio. Subject to the provisions of § 158.211 of this subpart: (a) Large...

45 CFR 158.210 - Minimum medical loss ratio.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 1 2011-10-01 2011-10-01 false Minimum medical loss ratio. 158.210 Section 158.210 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS... § 158.210 Minimum medical loss ratio. Subject to the provisions of § 158.211 of this subpart: (a) Large...

Theoretical study of ZnS/CdS bi-layer for thin-film CdTe solar cell

NASA Astrophysics Data System (ADS)

Mohamed, H. A.; Mohamed, A. S.; Ali, H. M.

2018-05-01

The performance of CdTe solar cells is strongly limited by the thickness of CdS window layer. A higher short-circuit current density might be achieved by decreasing the thickness of CdS layer as a result of reducing the absorption losses that take place in this layer. However, it is difficult to obtain uniform and pin-hole free CdS layers thinner than 50 nm. This problem can be solved through increasing the band gap of the window layer by adding a wide band gap semiconductor such as ZnS. In this work, bi-layer ZnS/CdS film was studied as an improved window layer of ITO/ZnS/CdS/CdTe solar cell. The total thickness of ZnS/CdS layer was taken about 60 nm. The effect of optical losses due to reflection at different interfaces in the cell and absorption in ITO, ZnS, CdS as well as the recombination loss have been studied. Finally, the effects of the recombination losses in the space-charge region and the reflectivity from the back contact were taken into accounts. The results revealed that the optical losses of 23% were achieved at 60 nm thickness of CdS and theses losses minimized to 18% when ZnS layer of 30 nm thickness was added to CdS layer. The minimum optical and recombination losses of about 26% were obtained at 1 ns of electron life-time and ∼0.4 μm width of the space-charge region. The maximum efficiency of 18.5% was achieved for ITO/CdS/CdTe cell and the efficiency increased up to 20% for ITO/ZnS/CdS/CdTe cell.

Ocean Color and Evidence of Chlorophyll Signature in the TOMS Minimum Reflectivity Data

NASA Technical Reports Server (NTRS)

Ahmad, Z.; Herman, J. R.; Bhartia, P. K.

2003-01-01

Analysis of the TOMS minimum reflectivity data for 380 nm channel (R380) show regions of high reflectivity values (approx. 7 to 8%) over Sargasso Sea in the Northern Atlantic, anti-cyclonic region in the Southern Atlantic, and a large part of the ocean in the Southern Pacific, and low values (5 approx. 6 %) over the rest of the open ocean. Through radiative transfer simulations we show that these features are highly correlated with the distribution of chlorophyll in the ocean. Theoretical minimum reflectivity values derived with the help of CZCS chlorophyll concentration data as input into a vector ocean-atmosphere radiative transfer code developed by Ahmad and Fraser show very good agreement with TOMS minimum reflectivity data for the winter season of year 1980. For the summer season of year 1980, good qualitative agreement is observed in the equatorial and northern hemisphere but not as good in the southern hemisphere. Also, for cloud-free conditions, we find a very strong correlation between R340 minus R380 values and the chlorophyll concentration in the ocean. Results on the possible effects of absorbing and non-absorbing aerosols on the TOMS minimum reflectivity will also be presented. The results also imply that ocean color will affect the aerosol retrieval over oceans unless corrected.

Cobalt ferrite sphere-coated buckhorn-like barium titanate: Fabrication, characterization, its dielectric resonance, and microwave attenuation properties

NASA Astrophysics Data System (ADS)

Ji, Renlong; Cao, Chuanbao

2014-10-01

Barium titanate (BTO) with different morphology is prepared through hydrothermal method using titania spheres as precursor, then calcined at different temperatures and ultimately coated with cobalt ferrite (BTO/CFO). The dielectric dispersion of the composite containing BTO (75 wt. % ratio in paraffin wax) shows evidence of resonance behaviour in the microwave spectrum, rather than the usually observed relaxation mode. The imaginary part of permittivity (ɛ″) displays a strong peak in the 10-13 GHz frequency region, especially for buckhorn-like BTO (hydrothermally synthesized at 110 °C and calcined at 1100 °C). The dielectric response anomaly of BTO in special morphology is due to the emission of plane acoustic waves caused by electrostrictive and converse piezoelectric effects. An accepted model is adopted to simulate the resonance frequency. The minimum reflection loss of cauliflower-like BTO (hydrothermally synthesized at 110 °C, then calcined at 600 °C for 2 h, 75 wt. % ratio) in paraffin wax reaches -30.831 dB at 10.56 GHz with a matching thickness of 2 mm, lower than all the reported values. When the sintering temperature is changed to 1100 °C (buckhorn-like BTO), the minimum reflection loss value is -24.37 dB at 12.56 GHz under the thickness of 3 mm. After combination with CFO, the value reaches -42.677 dB when the thickness is 5.6 mm. The ginger-like BTO (hydrothermally synthesized at 200 °C and calcined at different temperatures) is inferior in microwave reflection reduction. The electromagnetic interference shielding effectiveness of buckhorn-like BTO composite is calculated to be -12.7 dB (94.6% shielding) at resonance frequency (2 mm, 11.52 GHz). This work clearly shows the potential to tune the dielectric property of ferroelectrics through control of morphology, facilitating new comprehension of the ferroelectrics in microwave regime.

Nonimaging reflectors for efficient uniform illumination.

PubMed

Gordon, J M; Kashin, P; Rabl, A

1992-10-01

Nonimaging reflectors that are an extension of the design principle that was developed for compound parabolic concentrator type devices are proposed for illumination applications. The optical designs presented offer maximal lighting efficiency while they retain sharp angular control of the radiation and highly uniform flux densities on distant target planes. Our results are presented for symmetrical configurations in two dimensions (troughlike reflectors) for flat and for tubular sources. For fields of view of practical interest (half-angle in the 30-60 degrees range), these devices can achieve minimum-tomaximum intensity ratios of 0.7, while they remain compact and incur low reflective losses.

A mechanism study of sound wave-trapping barriers.

PubMed

Yang, Cheng; Pan, Jie; Cheng, Li

2013-09-01

The performance of a sound barrier is usually degraded if a large reflecting surface is placed on the source side. A wave-trapping barrier (WTB), with its inner surface covered by wedge-shaped structures, has been proposed to confine waves within the area between the barrier and the reflecting surface, and thus improve the performance. In this paper, the deterioration in performance of a conventional sound barrier due to the reflecting surface is first explained in terms of the resonance effect of the trapped modes. At each resonance frequency, a strong and mode-controlled sound field is generated by the noise source both within and in the vicinity outside the region bounded by the sound barrier and the reflecting surface. It is found that the peak sound pressures in the barrier's shadow zone, which correspond to the minimum values in the barrier's insertion loss, are largely determined by the resonance frequencies and by the shapes and losses of the trapped modes. These peak pressures usually result in high sound intensity component impinging normal to the barrier surface near the top. The WTB can alter the sound wave diffraction at the top of the barrier if the wavelengths of the sound wave are comparable or smaller than the dimensions of the wedge. In this case, the modified barrier profile is capable of re-organizing the pressure distribution within the bounded domain and altering the acoustic properties near the top of the sound barrier.

Detection of hail signatures from single-polarization C-band radar reflectivity

NASA Astrophysics Data System (ADS)

Kunz, Michael; Kugel, Petra I. S.

2015-02-01

Five different criteria that estimate hail signatures from single-polarization radar data are statistically evaluated over a 15-year period by categorical verification against loss data provided by a building insurance company. The criteria consider different levels or thresholds of radar reflectivity, some of them complemented by estimates of the 0 °C level or cloud top temperature. Applied to reflectivity data from a single C-band radar in southwest Germany, it is found that all criteria are able to reproduce most of the past damage-causing hail events. However, the criteria substantially overestimate hail occurrence by up to 80%, mainly due to the verification process using damage data. Best results in terms of highest Heidke Skill Score HSS or Critical Success Index CSI are obtained for the Hail Detection Algorithm (HDA) and the Probability of Severe Hail (POSH). Radar-derived hail probability shows a high spatial variability with a maximum on the lee side of the Black Forest mountains and a minimum in the broad Rhine valley.

Enhancing the microwave absorption properties of amorphous CoO nanosheet-coated Co (hexagonal and cubic phases) through interfacial polarizations.

PubMed

Deng, Jiushuai; Li, Shimei; Zhou, Yuanyuan; Liang, Luyang; Zhao, Biao; Zhang, Xi; Zhang, Rui

2018-01-01

Core-shell flower-like composites were successfully prepared by a simple polyol method. These composites were formed by coating dual-phased (face-centered cubic [fcc] and hexagonal close-packed [hcp]) Co with amorphous CoO nanosheets. The microwave absorption properties of the flower-like Co@CoO paraffin composites with various Co@CoO amounts were then investigated. Results showed that the paraffin-based composite containing 70wt% flower-like Co@CoO displayed excellent microwave absorption properties (R E =24.74dB·GHz/mm). The minimum reflection loss of -30.4dB was obtained at 16.1GHz with a small thickness of 1.5mm, and 1.5mm bandwidth reached 4.6GHz (13.4-18GHz) below -10dB (90% microwave absorption). The excellent microwave absorption properties of flower-like Co@CoO are attributed to the synergetic effect between magnetic loss and dielectric loss, and the magnetic loss makes a main contribution to absorption. The core-shell flower-like structures with dual Co phases also contributed to microwave absorption. The amorphous CoO nanosheets were able to generate multiple reflections and exhibit scattering. In addition, the novel absorption mechanism that enhanced interfacial polarization was proposed. This enhancement resulted from the presence of interfaces between the hcp and fcc phases and between the core-shell Co@CoO composites. Copyright © 2017 Elsevier Inc. All rights reserved.

Parametric study of minimum converter loss in an energy-storage dc-to-dc converter

NASA Technical Reports Server (NTRS)

Wong, R. C.; Owen, H. A., Jr.; Wilson, T. G.

1982-01-01

Through a combination of analytical and numerical minimization procedures, a converter design that results in the minimum total converter loss (including core loss, winding loss, capacitor and energy-storage-reactor loss, and various losses in the semiconductor switches) is obtained. Because the initial phase involves analytical minimization, the computation time required by the subsequent phase of numerical minimization is considerably reduced in this combination approach. The effects of various loss parameters on the optimum values of the design variables are also examined.

Low noise 874 GHz receivers for the International Submillimetre Airborne Radiometer (ISMAR)

NASA Astrophysics Data System (ADS)

Hammar, A.; Sobis, P.; Drakinskiy, V.; Emrich, A.; Wadefalk, N.; Schleeh, J.; Stake, J.

2018-05-01

We report on the development of two 874 GHz receiver channels with orthogonal polarizations for the International Submillimetre Airborne Radiometer. A spline horn antenna and dielectric lens, a Schottky diode mixer circuit, and an intermediate frequency (IF) low noise amplifier circuit were integrated in the same metallic split block housing. This resulted in a receiver mean double sideband (DSB) noise temperature of 3300 K (minimum 2770 K, maximum 3400 K), achieved at an operation temperature of 40 °C and across a 10 GHz wide IF band. A minimum DSB noise temperature of 2260 K at 20 °C was measured without the lens. Three different dielectric lens materials were tested and compared with respect to the radiation pattern and noise temperature. All three lenses were compliant in terms of radiation pattern, but one of the materials led to a reduction in noise temperature of approximately 200 K compared to the others. The loss in this lens was estimated to be 0.42 dB. The local oscillator chains have a power consumption of 24 W and consist of custom-designed Schottky diode quadruplers (5% power efficiency in operation, 8%-9% peak), commercial heterostructure barrier varactor (HBV) triplers, and power amplifiers that are pumped by using a common dielectric resonator oscillator at 36.43 GHz. Measurements of the radiation pattern showed a symmetric main beam lobe with full width half maximum <5° and side lobe levels below -20 dB. Return loss of a prototype of the spline horn and lens was measured using a network analyzer and frequency extenders to 750-1100 GHz. Time-domain analysis of the reflection coefficients shows that the reflections are below -25 dB and are dominated by the external waveguide interface.

Minimum Altitude-Loss Soaring in a Specified Vertical Wind Distribution

NASA Technical Reports Server (NTRS)

Pierson, B. L.; Chen, I.

1979-01-01

Minimum altitude-loss flight of a sailplane through a given vertical wind distribution is discussed. The problem is posed as an optimal control problem, and several numerical solutions are obtained for a sinusoidal wind distribution.

Superb electromagnetic wave-absorbing composites based on large-scale graphene and carbon nanotube films.

PubMed

Li, Jinsong; Lu, Weibang; Suhr, Jonghwan; Chen, Hang; Xiao, John Q; Chou, Tsu-Wei

2017-05-24

Graphene has sparked extensive research interest for its excellent physical properties and its unique potential for application in absorption of electromagnetic waves. However, the processing of stable large-scale graphene and magnetic particles on a micrometer-thick conductive support is a formidable challenge for achieving high reflection loss and impedance matching between the absorber and free space. Herein, a novel and simple approach for the processing of a CNT film-Fe 3 O 4 -large scale graphene composite is studied. The Fe 3 O 4 particles with size in the range of 20-200 nm are uniformly aligned along the axial direction of the CNTs. The composite exhibits exceptionally high wave absorption capacity even at a very low thickness. Minimum reflection loss of -44.7 dB and absorbing bandwidth of 4.7 GHz at -10 dB are achieved in composites with one-layer graphene in six-layer CNT film-Fe 3 O 4 prepared from 0.04 M FeCl 3 . Microstructural and theoretical studies of the wave-absorbing mechanism reveal a unique Debye dipolar relaxation with an Eddy current effect in the absorbing bandwidth.

Thermal conversion of an Fe₃O₄@metal-organic framework: a new method for an efficient Fe-Co/nanoporous carbon microwave absorbing material.

PubMed

Zhang, Xingmiao; Ji, Guangbin; Liu, Wei; Quan, Bin; Liang, Xiaohui; Shang, Chaomei; Cheng, Yan; Du, Youwei

2015-08-14

A novel FeCo nanoparticle embedded nanoporous carbon composite (Fe-Co/NPC) was synthesized via in situ carbonization of dehydro-ascorbic acid (DHAA) coated Fe3O4 nanoparticles encapsulated in a metal-organic framework (zeolitic imidazolate framework-67, ZIF-67). The molar ratio of Fe/Co significantly depends on the encapsulated content of Fe3O4 in ZIF-67. The composites filled with 50 wt% of the Fe-Co/NPC-2.0 samples in paraffin show a maximum reflection loss (RL) of -21.7 dB at a thickness of 1.2 mm; in addition, a broad absorption bandwidth for RL < -10 dB which covers from 12.2 to 18 GHz can be obtained, and its minimum reflection loss and bandwidth (RL values exceeding -10 dB) are far greater than those of commercial carbonyl iron powder under a very low thickness (1-1.5 mm). This study not only provides a good reference for future preparation of carbon-based lightweight microwave absorbing materials but also broadens the application of such kinds of metal-organic frameworks.

Investigation of the electronic, magnetic and optical properties of newest carbon allotrope

NASA Astrophysics Data System (ADS)

Kazemi, Samira; Moradian, Rostam

2018-05-01

We investigate triple properties of monolayer pentagon graphene that include electronic, magnetic and optical properties based on density functional theory (DFT). Our results show that in the electronic and magnetic properties this structure with a direct energy gap of about 2.2 eV along Γ - Γ direction and total magnetic moment of 0.0013 μB per unit cell is almost a non-magnetic semiconductor. Also, its optical properties show that if this allotrope used in solar cell technology, its efficiency in the low energy will be better, because, in the range of energy, its loss energy function and reflectivity will be minimum.

New approaches to removing cloud shadows and evaluating the 380 nm surface reflectance for improved aerosol optical thickness retrievals from the GOSAT/TANSO-Cloud and Aerosol Imager

NASA Astrophysics Data System (ADS)

Fukuda, Satoru; Nakajima, Teruyuki; Takenaka, Hideaki; Higurashi, Akiko; Kikuchi, Nobuyuki; Nakajima, Takashi Y.; Ishida, Haruma

2013-12-01

satellite aerosol retrieval algorithm was developed to utilize a near-ultraviolet band of the Greenhouse gases Observing SATellite/Thermal And Near infrared Sensor for carbon Observation (GOSAT/TANSO)-Cloud and Aerosol Imager (CAI). At near-ultraviolet wavelengths, the surface reflectance over land is smaller than that at visible wavelengths. Therefore, it is thought possible to reduce retrieval error by using the near-ultraviolet spectral region. In the present study, we first developed a cloud shadow detection algorithm that uses first and second minimum reflectances of 380 nm and 680 nm based on the difference in Rayleigh scattering contribution for these two bands. Then, we developed a new surface reflectance correction algorithm, the modified Kaufman method, which uses minimum reflectance data at 680 nm and the NDVI to estimate the surface reflectance at 380 nm. This algorithm was found to be particularly effective at reducing the aerosol effect remaining in the 380 nm minimum reflectance; this effect has previously proven difficult to remove owing to the infrequent sampling rate associated with the three-day recursion period of GOSAT and the narrow CAI swath of 1000 km. Finally, we applied these two algorithms to retrieve aerosol optical thicknesses over a land area. Our results exhibited better agreement with sun-sky radiometer observations than results obtained using a simple surface reflectance correction technique using minimum radiances.

Three-phase heterostructures f-NiFe2O4/PANI/PI EMI shielding fabric with high Microwave Absorption Performance

NASA Astrophysics Data System (ADS)

Wang, Yu; Wang, Wei; Yu, Dan

2017-12-01

In this work, a three-phase heterostructures f-NiFe2O4/PANI/PI EMI shielding fabric with a layer by layer structure was designed and prepared to obtain excellent microwave attenuation performance. Firstly, PANI/PI fabric was prepared via in-situ deposition method. Then, the NiFe2O4 nanoparticles functionalized by oleic acid were uniformly dispersed in epoxy resin and coated on the top and bottom of PANI/PI fabric with 0.041 mm total thickness. The investigation of chemical structure and surface morphologies indicated the composite structure of f-NiFe2O4/PANI/PI fabric. Various parameters like magnetic property, reflection loss and attenuation constant were used to evaluate its microwave attenuation performance. The results demonstrated that the 30f-NiFe2O4/PANI/PI fabric had a highest attenuation effectiveness with the minimum reflection loss value of -42.5 dB (>90% attenuation) at 12.5 GHz and the effective absorption bandwidth was 3.4 GHz. The study of attenuation mechanism indicated that the dielectric loss from PANI, the magnetic loss caused by f-NiFe2O4 and the layer by layer structure effectively improved microwave attenuation performance of composite fabric. Furthermore, the favorable flexibility and dimensional stability of this resultant fabric would allow the composite fabric for a long time service under pressure or foldable conditions. In sum, the study clearly indicated that three-phase heterostructures f-NiFe2O4/PANI/PI fabric was a good candidate as electromagnetic shielding materials in many fields.

49 CFR 393.11 - Lamps and reflective devices.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., reflective devices and associated equipment by the type of commercial motor vehicle. The diagrams in this... Table 1. All commercial motor vehicles manufactured on or after December 25, 1968, must, at a minimum... of the vehicle. Commercial motor vehicles manufactured before December 25, 1968, must, at a minimum...

A Study of the World’s Naval Surface-to-Air Missile Defense Systems.

DTIC Science & Technology

1984-12-01

in various installations to foreign radars, such as the Contraves SeaHunter, SanGiogio NA9. A light- weight , three-round launcher (based on the short... Losses . . . . . . . . . . . . . . 22 7- B. MINIMUM SIGNAL DETECTION . . . . . . . . . . . 22 1. Noise Figure F ......... ..... 25 2. Minimum Signal-to...idealized radar equation becomes Pr 4>, 2 (2. 11) a, 4 2. S Losses There are many sources of power loss in the echo, and these losses reduce the energy of

Theoretical studies on leaky-SAW properties influenced by layers on anisotropic piezoelectric crystals.

PubMed

Wallner, P; Ruile, W; Weigel, R

2000-01-01

Theoretical studies on the behavior of leaky-SAW (LSAW) properties in layered structures were performed. For these calculations rotYX LiTaO (3) and rotYX LiNbO(3) LSAW crystal cuts were used, assuming different layer materials. For LSAWs both the velocity and the inherent loss due to bulk wave emission into the substrate are strongly influenced by distinct layer parameters. As a result, these layer properties like elastic constants or thickness have shown a strong influence on the crystal cut angle of minimum LSAW loss. Moreover, for soft and stiff layer materials, a different shift of the LSAW loss minimum can occur. Therefore, using double-layer structures, the shift of the LSAW loss minimum can be influenced by appropriate chosen layers and ratios.

Wideband acoustic immittance for assessing middle ear functioning for preterm neonates in the neonatal intensive care unit.

PubMed

Gouws, Nandel; Swanepoel, De Wet; De Jager, Leigh Biagio

2017-06-28

The primary aim of newborn hearing screening is to detect permanent hearing loss. Because otoacoustic emissions (OAEs) and automated auditory brainstem response (AABR) are sensitive to hearing loss, they are often used as screening tools. On the other hand, false-positive results are most often because of transient outer- and middle ear conditions. Wideband acoustic immittance (WAI), which includes physical measures known as reflectance and absorbance, has shown potential for accurate assessment of middle ear function in young infants. The main objective of this study was to determine the feasibility of WAI as a diagnostic tool for assessing middle ear functioning in preterm neonates in the neonatal intensive care unit (NICU) designed for premature and ill neonates. A further objective was to indicate the difference between the reflectance values of tones and click stimuli. Fifty-six at-risk neonates (30 male and 26 female), with a mean age at testing of 35.6 weeks (range: 32-37 weeks) and a standard deviation of 1.6 from three private hospitals, who passed both the distortion product otoacoustic emission (DPOAE) and AABR tests, were evaluated prior to discharge from the NICU. Neonates who presented with abnormal DPOAE and AABR results were excluded from the study. WAI was measured by using chirp and tone stimuli. In addition to reflectance, the reflectance area index (RAI) values were calculated. Both tone and chirp stimuli indicated high-power reflectance values below a frequency of 1.5 kHz. Median reflectance reached a minimum of 0.67 at 1 kHz - 2 kHz but increased to 0.7 below 1 kHz and 0.72 above 2 kHz for the tone stimuli. For chirp stimuli, the median reflectance reached a minimum of 0.51 at 1 kHz - 2 kHz but increased to 0.68 below 1 kHz and decreased to 0.5 above 2 kHz. A comparison between the present study and previous studies on WAI indicated a substantial variability across all frequency ranges. These WAI measurements conducted on at-risk preterm NICU neonates (mean age at testing: 35.6 weeks, range: 32-37 weeks) identified WAI patterns not previously reported in the literature. High reflective values were obtained across all frequency ranges. The age of the neonates when tested might have influenced the results. The neonates included in the present study were very young preterm neonates compared to the ages of neonates in previous studies. WAI measured in at-risk preterm neonates in the NICU was variable with environmental and internal noise influences. Transient conditions affecting the sound-conduction pathway might have influenced the results. Additional research is required to investigate WAI testing in ears with and without middle ear dysfunction. The findings of the current study imply that in preterm neonates it was not possible to determine the feasibility of WAI as a diagnostic tool to differentiate between ears with and without middle ear pathology.

Reduction of temperature rise in high-speed photography

NASA Technical Reports Server (NTRS)

Slater, Howard A.

1987-01-01

Information is provided on filtration with glass and infrared absorbing and reflecting filters. Glass and infrared filtration is a simple and effective method to reduce the radiation heat transfer associated with continuous high intensity tungsten lamps. The results of a filtration experiment are explained. The figures provide starting points for quantifying the effectiveness of various filters and associated light intensities. The combination of a spectrally selective reflector (hot or cold mirror) based on multilayer thin film principles and heat absorbing or infrared opaque glass results in the maximum reduction in temperature rise with a minimum of incident light loss. Use is recommended of a voltage regulator to further control temperature rise and incident light values.

Reduction of temperature rise in high-speed photography

NASA Technical Reports Server (NTRS)

Slater, Howard A.

1988-01-01

Information is provided on filtration with glass and infrared absorbing and reflecting filters. Glass and infrared filtration is a simple and effective method to reduce the radiation heat transfer associated with continuous high intensity tungsten lamps. The results of a filtration experiment are explained. The figures provide starting points for quantifying the effectiveness of various filters and associated light intensities. The combination of a spectrally selective reflector (hot or cold mirror) based on multilayer thin film principles and heat absorbing or infrared opaque glass results in the maximum reduction in temperature rise with a minimum of incident light loss. Use is recommended of a voltage regulator to further control temperature rise and incident light values.

Optimization of reading conditions for flat panel displays.

PubMed

Thomas, J A; Chakrabarti, K; Kaczmarek, R V; Maslennikov, A; Mitchell, C A; Romanyukha, A

2006-06-01

Task Group 18 (TG 18) of the American Association of Physicists in Medicine has developed guidelines for Assessment of Display Performance for Medical Imaging Systems. In this document, a method for determination of the maximum room lighting for displays is suggested. It is based on luminance measurements of a black target displayed on each display device at different room illuminance levels. Linear extrapolation of the above luminance measurements vs. room illuminance allows one to determine diffuse and specular reflection coefficients. TG 18 guidelines have established recommended maximum room lighting. It is based on the characterization of the display by its minimum and maximum luminance and the description of room by diffuse and specular coefficients. We carried out these luminance measurements for three selected displays to determine their optimum viewing conditions: one cathode ray tube and two flat panels. We found some problems with the application of the TG 18 guidelines to optimize viewing conditions for IBM T221 flat panels. Introduction of the requirement for minimum room illuminance allows a more accurate determination of the optimal viewing conditions (maximum and minimum room illuminance) for IBM flat panels. It also addresses the possible loss of contrast in medical images on flat panel displays because of the effect of nonlinearity in the dependence of luminance on room illuminance at low room lighting.

26 CFR 1.383-2 - Limitations on certain capital losses and excess credits in computing alternative minimum tax...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 4 2010-04-01 2010-04-01 false Limitations on certain capital losses and excess credits in computing alternative minimum tax. [Reserved] 1.383-2 Section 1.383-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Insolvency...

Cost of and soil loss on "minimum-standard" forest truck roads constructed in the central Appalachians

Treesearch

J. N. Kochenderfer; G. W. Wendel; H. Clay Smith

1984-01-01

A "minimum-standard" forest truck road that provides efficient and environmentally acceptable access for several forest activities is described. Cost data are presented for eight of these roads constructed in the central Appalachians. The average cost per mile excluding gravel was $8,119. The range was $5,048 to $14,424. Soil loss was measured from several...

Minimum Surface-Effect Microgripper Design for Force-Reflective Telemanipulation of a Microscopic Environment

NASA Technical Reports Server (NTRS)

Goldfarb, Michael; Celanovic, Nikola

1996-01-01

This paper describes the fundamental physical motivations for minimum surface effect design, and presents a microgripper that incorporates a piezoelectric ceramic actuator and a flexure-based structure and transmission. The microgripper serves effectively as a one degree-of-freedom prototype of minimum surface effect micromanipulator design. Data is presented that characterizes the microgripper performance under both pure position and pure force control, followed by a discussion of the attributes and limitations of flexure-based design. The microgripper is interfaced with a force-reflective macrogripper, and the pair controlled with a hybrid position/force scheme. Data is presented that illustrates the effective operation of the telerobotic pair.

Electromagnetic and Microwave Absorption Properties of the Flake-Shaped Pr-Ho-Fe Alloys in the C-Band

NASA Astrophysics Data System (ADS)

Luo, Jialiang; Pan, Shunkang; Qiao, Ziqiang; Cheng, Lichun; Wang, Zhenzhong; Lin, Peihao; Chang, Junqing

2018-01-01

The polycrystalline samples Pr x Ho2- x Fe17 ( x = 0.0, 0.1, 0.2, 0.3, 0.4) were prepared by arc melting and high-energy ball milling method. The influences of Pr substitution on phase structure, morphology, saturation magnetization and electromagnetic parameters were investigated by x-ray diffraction, scanning electron microscopy, vibrating-sample magnetometry and vector network analyzer, respectively. The results show that the particle size increased and the saturation magnetization decreased with increasing Pr content. The minimum absorption peak frequency shifted towards a lower-frequency region with increasing Pr concentration. The minimum RL of Pr0.3Ho1.7Fe17 powder was -41.03 dB at 6.88 GHz with a coating thickness of 2.0 mm. With different thickness of 1.8-2.8 mm, the minimum reflection loss (RL) of Pr0.3Ho1.7Fe17 powder was less than -20 dB in the whole C-band (4-8 GHz). The microwave-absorbing properties of the composite with different weight ratios of Pr0.3Ho1.7Fe17/Co were researched. The microwave-absorbing peaks of the composites shifted to a lower frequency with increasing Co content. The minimum RL of Pr0.3Ho1.7Fe17/Co(10%) was -42.51 dB at 4.72 GHz with a coating thickness of 2.6 mm. This suggests that the Pr-Ho-Fe will be a promising microwave absorption material in higher-gigahertz frequency, especially in the C-band.

Elevated temperature ductility of types 304 and 316 stainless steel. [640/sup 0/ to 750/sup 0/C

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

Sikka, V. K.

1978-01-01

Austenitic stainless steel types 304 and 316 are known for their high ductility and toughness. However, the present study shows that certain combinations of strain rate and test temperature can result in a significant loss in elevated-temperature ductility. Such a phenomenon is referred to as ductility minimum. The strain rate, below which ductility loss is initiated, decreases with decrease in test temperature. Besides strain rate and temperature, the ductility minimum was also affected by nitrogen content and thermal aging conditions. Thermal aging at 649/sup 0/C was observed to eliminate the ductility minimum at 649/sup 0/C in both types 304 andmore » 316 stainless steel. Such an aging treatment resulted in a higher ductility than the unaged value. Aging at 593/sup 0/C still resulted in some loss in ductility. Current results suggest that ductility-minimum conditions for stainless steel should be considered in design, thermal aging data analysis, and while studying the effects of chemical composition.« less

Minimum surface-effect microgripper design for force-reflective telemanipulation of a microscopic environment

NASA Technical Reports Server (NTRS)

Goldfarb, Michael; Celanovic, Nikola

1996-01-01

This paper describes the fundamental physical motivations for a minimum surface effect design, and presents a microgripper that incorporates a piezoelectric ceramic actuator and a flexure-based structure and transmission. The microgripper serves effectively as a one degree-of-freedom prototype of a minimum surface effect micromanipulator design. Data is presented that characterizes the microgripper performance under both pure position and pure force control, followed by a discussion of the attributes and limitations of flexure-based design. The microgripper is interfaced with a force reflective macrogripper, and the pair is controlled with a hybrid position/force scheme. Data is presented that illustrates the effective operation of the telerobotic pair.

Microporous Co@C Nanoparticles Prepared by Dealloying CoAl@C Precursors: Achieving Strong Wideband Microwave Absorption via Controlling Carbon Shell Thickness.

PubMed

Li, Da; Liao, Haoyan; Kikuchi, Hiroaki; Liu, Tong

2017-12-27

Excellent magnetic features make Co-based materials promising candidates as high-performance microwave absorbers. However, it is still a significant challenge for Co-based absorbers to possess high-intensity and broadband absorption simultaneously, owing to the lack of dielectric loss and impedance matching. Herein, microporous Co@C nanoparticles (NPs) with carbon shell thicknesses ranging from 1.8-4.9 nm have been successfully synthesized by dealloying CoAl@C precursors. All of the samples exhibit high microwave absorption performance. The microporous Co@C sample possessing a carbon shell of 1.8 nm exhibits the highest absorption intensity among these samples with a minimum reflection loss (RL) of -141.1 dB, whose absorption bandwidth for RL ≤ -10 dB is 7.3 GHz. As the thickness of the carbon shell increases, the absorption bandwidth of the NPs becomes wider. For the sample with the carbon shell thickness of 4.9 nm, the absorption bandwidth for RL ≤ -10 dB reaches a record high of 13.2 GHz. The outstanding microwave attenuation properties are attributed to the dielectric loss of the carbon shell, the magnetic loss of the Co core, and the cooperation of the core-shell structure and microporous morphology. The strong wideband microwave absorption of the carbon-coated microporous Co NPs highlights their potential applications in microwave absorbing systems.

Preparation of nitrogen and sulfur co-doped ordered mesoporous carbon for enhanced microwave absorption performance

NASA Astrophysics Data System (ADS)

Yuan, Xiaoyan; Xue, Xingkun; Ma, Hailong; Guo, Shouwu; Cheng, Laifei

2017-09-01

Ordered mesoporous carbon nanomaterials (OMCs) co-doped with homogeneous nitrogen and sulfur heteroatoms were prepared by nanocasting with the pyrrole oligomer catalyzed by sulfuric acid as a precursor and ordered mesoporous silica SBA-15 as a hard-template. By multi-technique approach utilization, it was demonstrated that the N and S co-doped OMCs possessed high ordered mesoporous structures, large surface areas and homogeneous distribution of heteroatoms. As a microwave absorber, the as-prepared materials exhibited a minimum reflection loss (RL) of -32.5 dB at the thickness of 2.5 mm and an absorption bandwidth of 3.2 GHz (RL < -10 dB) in X-band (8.2-12.4 GHz). The good microwave absorption performance was mainly originated from the high electrical conductivity induced by the high surface activity and special structures. And microwave energy can be effectively attenuated through multiple reflections and absorptions in complex conductive network. The design strategy in this work would contribute to the production of a lightweight absorber, presenting a strong absorbency and a wide bandwidth in microwave frequency.

Effects of ordered mesoporous structure and La-doping on the microwave absorbing properties of CoFe2O4

NASA Astrophysics Data System (ADS)

Shang, Tao; Lu, Qingshan; Chao, Luomeng; Qin, Yanli; Yun, Yuehou; Yun, Guohong

2018-03-01

Low-density ordered mesoporous CoFe2O4 (Osbnd CFO) and CoLa0.12Fe1.88O4 (Osbnd CLFO) are prepared by nanocasting method using mesoporous silica SBA-15 as a hard-template. The crystal structure, surface chemical state, magnetic properties and electromagnetic parameters are characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurement, X-ray photoelectron spectroscopy, physical property measurement system and vector network analyzer. The results show that all the samples formed a single phase with cubic spinel structure. Meanwhile Osbnd CFO and Osbnd CLFO possess a highly ordered mesostructure. Comparing with particle CoFe2O4 (P-CFO), Osbnd CFO with high specific surface area exhibits lower magnetic saturation (Ms), higher imaginary part of complex permittivity (ε‧‧) and imaginary part of the complex permeability (μ‧‧). The minimum reflection loss (RL) of Osbnd CFO reaches -27.36 dB with a matching thickness of 3.0 mm. The enhancement of the microwave absorbing performances of Osbnd CFO can be mainly attributed to the good impedance matching, high electromagnetic wave attenuation and multiple reflections of electromagnetic wave originated from the ordered mesoporous structure. The Ms of Osbnd CLFO decreases after La3+ doping, while the specific surface area, coercivity value, ε‧‧ and μ‧‧ of Osbnd CLFO increase. The minimum RL of Osbnd CLFO reaches -46.47 dB with a thickness of 3.0 mm, and the effective absorption frequency bandwidth reaches 4.9 GHz.

Fabrication and Electromagnetic Properties of Conjugated NH2-CuPc@Fe3O4

NASA Astrophysics Data System (ADS)

Yan, Liang; Pu, Zejun; Xu, Mingzhen; Wei, Renbo; Liu, Xiaobo

2017-10-01

Conjugated amino-phthalocyanine copper containing carboxyl groups/magnetite (NH2-CuPc@Fe3O4) has been fabricated from FeCl3·6H2O and NH2-CuPc via a simple solvothermal method and its electromagnetic properties investigated. Scanning electron microscopy and transmission electron microscopy revealed that the NH2-CuPc@Fe3O4 was a waxberry-like nanomaterial with NH2-CuPc molecules effectively embedded in the interior of Fe3O4 particles in the form of beads. Introduction of NH2-CuPc effectively improved the complementarity between the dielectric and magnetic losses of the system, resulting in excellent electromagnetic performance. The minimum reflection loss of the as-prepared composite reached -33.4 dB at 7.0 GHz for coating layer thickness of 4.0 mm and bandwidth below -10.0 dB (90% absorption) of up to 3.8 GHz. These results indicate that introduction of NH2-CuPc results in a composite with potential for use as an electromagnetic microwave absorption material.

LIQHYSMES - spectral power distributions of imbalances and implications for the SMES

NASA Astrophysics Data System (ADS)

Sander, M.; Gehring, R.; Neumann, H.

2014-05-01

LIQHYSMES, the recently proposed hybrid energy storage concept for variable renewable energies, combines the storage of LIQuid HYdrogen (LH2) with Superconducting Magnetic Energy Storage (SMES). LH2 as the bulk energy carrier is used for the large scale stationary longer-term energy storage, and the SMES cooled by the LH2 bath, provides highest power over shorter periods and at superior efficiencies. Both together contribute to the balancing of electric load or supply fluctuations from seconds to several hours, days or even weeks. Here different spectral power distributions of such imbalances between electricity supply and load reflecting different sources of fluctuations in the range between 1 sec and 15 minutes are considered. Some related implications for MgB2-based 100 MW-SMES operated at maximum fields of 2 T and 4 T, are considered for these buffering scenarios. Requirements as regards the storage capacity and correspondingly the minimum size of the LH2 storage tank are derived. The related loss contributions with a particular focus on the ramping losses are analysed.

Superior microwave absorption properties of ultralight reduced graphene oxide/black phosphorus aerogel.

PubMed

Hao, Chunxue; Wang, Bochong; Wen, Fusheng; Mu, Congpu; Xiang, Jianyong; Li, Lei; Liu, Zhongyuan

2018-06-08

Through a facile self-assembled process, an ultralight reduced graphene oxide/black phosphorus (rGO/BP) composite aerogel was successfully fabricated. The BP nanosheets were homogeneously distributed throughout the rGO 3D framework, and the interfaces between rGO and BP possessed four kinds of interconnections, such as wrapping, wearing, bridging and weak linking. As an ultralight composite, the rGO/BP aerogel could easily stand on the stamen of a flower. Compared with pure rGO aerogel, the rGO/BP composite aerogel exhibited enhanced microwave absorption ability. The minimum reflection loss value of -46.9 dB with a thickness of 2.53 mm was obtained, and a wide absorption band of 6.1 GHz (RL < -10 dB) was achieved. The superior microwave absorption property was demonstrated to stem from the interfacial polarization loss mechanism in which the multiform interface interactions between the rGO skeleton and BP nanosheets played critical roles. The rGO/BP aerogel has great potential to be used as an ultralight microwave absorber.

Superior microwave absorption properties of ultralight reduced graphene oxide/black phosphorus aerogel

NASA Astrophysics Data System (ADS)

Hao, Chunxue; Wang, Bochong; Wen, Fusheng; Mu, Congpu; Xiang, Jianyong; Li, Lei; Liu, Zhongyuan

2018-06-01

Through a facile self-assembled process, an ultralight reduced graphene oxide/black phosphorus (rGO/BP) composite aerogel was successfully fabricated. The BP nanosheets were homogeneously distributed throughout the rGO 3D framework, and the interfaces between rGO and BP possessed four kinds of interconnections, such as wrapping, wearing, bridging and weak linking. As an ultralight composite, the rGO/BP aerogel could easily stand on the stamen of a flower. Compared with pure rGO aerogel, the rGO/BP composite aerogel exhibited enhanced microwave absorption ability. The minimum reflection loss value of ‑46.9 dB with a thickness of 2.53 mm was obtained, and a wide absorption band of 6.1 GHz (RL < ‑10 dB) was achieved. The superior microwave absorption property was demonstrated to stem from the interfacial polarization loss mechanism in which the multiform interface interactions between the rGO skeleton and BP nanosheets played critical roles. The rGO/BP aerogel has great potential to be used as an ultralight microwave absorber.

Synthesis and microwave absorbing characteristics of functionally graded carbonyl iron/polyurethane composites

NASA Astrophysics Data System (ADS)

Yang, R. B.; Liang, W. F.; Wu, C. H.; Chen, C. C.

2016-05-01

Radar absorbing materials (RAMs) also known as microwave absorbers, which can absorb and dissipate incident electromagnetic wave, are widely used in the fields of radar-cross section reduction, electromagnetic interference (EMI) reduction and human health protection. In this study, the synthesis of functionally graded material (FGM) (CI/Polyurethane composites), which is fabricated with semi-sequentially varied composition along the thickness, is implemented with a genetic algorithm (GA) to optimize the microwave absorption efficiency and bandwidth of FGM. For impedance matching and broad-band design, the original 8-layered FGM was obtained by the GA method to calculate the thickness of each layer for a sequential stacking of FGM from 20, 30, 40, 50, 60, 65, 70 and 75 wt% of CI fillers. The reflection loss of the original 8-layered FGM below -10 dB can be obtained in the frequency range of 5.12˜18 GHz with a total thickness of 9.66 mm. Further optimization reduces the number of the layers and the stacking sequence of the optimized 4-layered FGM is 20, 30, 65, 75 wt% with thickness of 0.8, 1.6, 0.6 and 1.0 mm, respectively. The synthesis and measurement of the optimized 4-layered FGM with a thickness of 4 mm reveal a minimum reflection loss of -25.2 dB at 6.64 GHz and its bandwidth below - 10 dB is larger than 12.8 GHz.

The Maximums and Minimums of a Polnomial or Maximizing Profits and Minimizing Aircraft Losses.

ERIC Educational Resources Information Center

Groves, Brenton R.

1984-01-01

Plotting a polynomial over the range of real numbers when its derivative contains complex roots is discussed. The polynomials are graphed by calculating the minimums, maximums, and zeros of the function. (MNS)

Subjective well-being and minimum wages: Evidence from U.S. states.

PubMed

Kuroki, Masanori

2018-02-01

This paper investigates whether increases in minimum wages are associated with higher life satisfaction by using monthly-level state minimum wages and individual-level data from the 2005-2010 Behavioral Risk Factor Surveillance System. The magnitude I find suggests that a 10% increase in the minimum wage is associated with a 0.03-point increase in life satisfaction for workers without a high school diploma, on a 4-point scale. Contrary to popular belief that higher minimum wages hurt business owners, I find little evidence that higher minimum wages lead to the loss of well-being among self-employed people. Copyright © 2017 John Wiley & Sons, Ltd.

A cellular glass substrate solar concentrator

NASA Technical Reports Server (NTRS)

Bedard, R.; Bell, D.

1980-01-01

The design of a second generation point focusing solar concentration is discussed. The design is based on reflective gores fabricated of thin glass mirror bonded continuously to a contoured substrate of cellular glass. The concentrator aperture and structural stiffness was optimized for minimum concentrator cost given the performance requirement of delivering 56 kWth to a 22 cm diameter receiver aperture with a direct normal insolation of 845 watts sq m and an operating wind of 50 kmph. The reflective panel, support structure, drives, foundation and instrumentation and control subsystem designs, optimized for minimum cost, are summarized. The use of cellular glass as a reflective panel substrate material is shown to offer significant weight and cost advantages compared to existing technology materials.

Effects of the morphology of CIPs on microwave absorption behaviors

NASA Astrophysics Data System (ADS)

Woo, Soobin; Yoo, Chan-Sei; Kim, Hwijun; Lee, Mijung; Quevedo-Lopez, Manuel; Choi, Hyunjoo

2017-11-01

Electromagnetic (EM) wave absorption properties are affected by the thickness and surface area of absorbing materials. In this study, a facile ball-milling process was introduced to effectively reduce the diameter and increase the aspect ratio of carbonyl iron powder (CIP), which is one of the most commercially available EM-absorbing materials. The size, aspect ratio, and consequent surface area of CIP were manipulated by controlling the milling parameters to investigate their effects on EM absorption properties. The results indicated that ball-milled CIPs exhibited better EM wave absorption ability when compared with that of pristine CIPs. However, significant differences in minimum reflection loss values were not observed between CIPs with different morphologies and similar specific surface areas. Hence, both fine and flaky CIPs were considered as beneficial for EM wave absorption.[Figure not available: see fulltext.

Crop production and economic loss due to wind erosion in hot arid ecosystem of India

NASA Astrophysics Data System (ADS)

Santra, Priyabrata; Moharana, P. C.; Kumar, Mahesh; Soni, M. L.; Pandey, C. B.; Chaudhari, S. K.; Sikka, A. K.

2017-10-01

Wind erosion is a severe land degradation process in hot arid western India and affects the agricultural production system. It affects crop yield directly by damaging the crops through abrasion, burial, dust deposition etc. and indirectly by reducing soil fertility. In this study, an attempt was made to quantify the indirect impact of wind erosion process on crop production loss and associated economic loss in hot arid ecosystem of India. It has been observed that soil loss due to wind erosion varies from minimum 1.3 t ha-1 to maximum 83.3 t ha-1 as per the severity. Yield loss due to wind erosion was found maximum for groundnut (Arachis hypogea) (5-331 kg ha-1 yr-1), whereas minimum for moth bean (Vigna aconitifolia) (1-93 kg ha-1 yr-1). For pearl millet (Pennisetum glaucum), which covers a major portion of arable lands in western Rajasthan, the yield loss was found 3-195 kg ha-1 yr-1. Economic loss was found higher for groundnut and clusterbean (Cyamopsis tetragonoloba) than rest crops, which are about

Trends in annual minimum exposed snow and ice cover in High Mountain Asia from MODIS

NASA Astrophysics Data System (ADS)

Rittger, Karl; Brodzik, Mary J.; Painter, Thomas H.; Racoviteanu, Adina; Armstrong, Richard; Dozier, Jeff

2016-04-01

Though a relatively short record on climatological scales, data from the Moderate Resolution Imaging Spectroradiometer (MODIS) from 2000-2014 can be used to evaluate changes in the cryosphere and provide a robust baseline for future observations from space. We use the MODIS Snow Covered Area and Grain size (MODSCAG) algorithm, based on spectral mixture analysis, to estimate daily fractional snow and ice cover and the MODICE Persistent Ice (MODICE) algorithm to estimate the annual minimum snow and ice fraction (fSCA) for each year from 2000 to 2014 in High Mountain Asia. We have found that MODSCAG performs better than other algorithms, such as the Normalized Difference Index (NDSI), at detecting snow. We use MODICE because it minimizes false positives (compared to maximum extents), for example, when bright soils or clouds are incorrectly classified as snow, a common problem with optical satellite snow mapping. We analyze changes in area using the annual MODICE maps of minimum snow and ice cover for over 15,000 individual glaciers as defined by the Randolph Glacier Inventory (RGI) Version 5, focusing on the Amu Darya, Syr Darya, Upper Indus, Ganges, and Brahmaputra River basins. For each glacier with an area of at least 1 km2 as defined by RGI, we sum the total minimum snow and ice covered area for each year from 2000 to 2014 and estimate the trends in area loss or gain. We find the largest loss in annual minimum snow and ice extent for 2000-2014 in the Brahmaputra and Ganges with 57% and 40%, respectively, of analyzed glaciers with significant losses (p-value<0.05). In the Upper Indus River basin, we see both gains and losses in minimum snow and ice extent, but more glaciers with losses than gains. Our analysis shows that a smaller proportion of glaciers in the Amu Darya and Syr Darya are experiencing significant changes in minimum snow and ice extent (3.5% and 12.2%), possibly because more of the glaciers in this region are smaller than 1 km2 than in the Indus, Ganges, and Brahmaputra making analysis from MODIS (pixel area ~0.25 km2) difficult. Overall, we see 23% of the glaciers in the 5 river basins with significant trends (in either direction). We relate these changes in area to topography and climate to understand the driving processes related to these changes. In addition to annual minimum snow and ice cover, the MODICE algorithm also provides the date of minimum fSCA for each pixel. To determine whether the surface was snow or ice we use the date of minimum fSCA from MODICE to index daily maps of snow on ice (SOI), or exposed glacier ice (EGI) and systematically derive an equilibrium line altitude (ELA) for each year from 2000-2014. We test this new algorithm in the Upper Indus basin and produce annual estimates of ELA. For the Upper Indus basin we are deriving annual ELAs that range from 5350 m to 5450 m which is slightly higher than published values of 5200 m for this region.

Development of optical coatings for 157-nm lithography. II. Reflectance, absorption, and scatter measurement

NASA Astrophysics Data System (ADS)

Otani, Minoru; Biro, Ryuji; Ouchi, Chidane; Hasegawa, Masanobu; Suzuki, Yasuyuki; Sone, Kazuho; Niisaka, Shunsuke; Saito, Tadahiko; Saito, Jun; Tanaka, Akira

2002-06-01

The total loss that can be suffered by an antireflection (AR) coating consists of reflectance loss, absorption loss, and scatter loss. To separate these losses we developed a calorimetric absorption measurement apparatus and an ellipsoidal Coblentz hemisphere based scatterometer for 157-nm optics. Reflectance, absorption, and scatter of AR coatings were measured with these apparatuses. The AR coating samples were supplied by Japanese vendors. Each AR coating as supplied was coated with the vendor's coating design by that vendor's coating process. Our measurement apparatuses, methods, and results for these AR coatings are presented here.

Current pulse amplifier transmits detector signals with minimum distortion and attenuation

NASA Technical Reports Server (NTRS)

Bush, N. E.

1967-01-01

Amplifier translates the square pulses generated by a boron-trifluoride neutron sensitive detector located adjacent to a nuclear reactor to slower, long exponential decay pulses. These pulses are transmitted over long coaxial cables with minimum distortion and loss of frequency.

Modulation of electromagnetic and absorption properties in 18-26.5 GHz frequency range of strontium hexaferrites with doping of cobalt-zirconium

NASA Astrophysics Data System (ADS)

Pubby, Kunal; Narang, Sukhleen Bindra; Kaur, Prabhjyot; Chawla, S. K.

2017-05-01

Hexaferrite nano-particles of stoichiometric composition {{Sr}}{({{CoZr}})_x}{{F}}{{{e}}_{12 - 2x}}{{{O}}_{19}}, with x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0 were prepared using sol-gel auto-combustion route owing to its advantages such as low sintering temperature requirement, homogeneity and uniformity of grains. Tartaric acid as a fuel was utilized to complete the chemical reaction. The goal of this study is to analyse the effect of co-substitution of cobalt and zirconium on the electromagnetic and absorption properties of pure {{SrF}}{{{e}}_{12}}{{{O}}_{19}} hexaferrite. The properties were measured on the rectangular pellets of thickness 2.5 mm for K-frequency band using Vector Network Analyzer. The doping of Co-Zr has resulted in increase in real as well as imaginary parts of permittivity. The values of real permittivity lie in the range 3.6-7.0 for all the composition. The real part of permeability remains in range 0.7-1.6 in the studied frequency band for all the samples and shows slightly increasing trend with frequency. The maximum values of dielectric loss tangent peak (3.04) and magnetic loss tangent peak (2.34), among all the prepared compositions, have been observed for composition x = 0.2. Compositions with x = 0.6 and x = 0.0 also have high dielectric and magnetic loss peaks. Dielectric loss peaks are attributed to dielectric resonance and magnetic loss peaks are attributed to natural resonance. Experimentally determined reflection loss results show that all six compositions of prepared series have high values of absorption to propose them as single-layer absorbers in 18-26.5 GHz frequency range. The composition with x = 0.2 has maximum absorption capacity with reflection loss peak of -37.2 dB at 24.3 GHz frequency. The undoped composition also has high absorption peak (-25.46 dB), but -10 dB absorption bandwidth is minimum (2.2 GHz) out of the present series. Maximum absorption bandwidth is obtained for x = 1.0 (4.1 GHz). Other doped compositions also have high absorption bandwidth in range 3.4-3.9 GHz. The results of absorption were related to the dielectric phase angle to conclude that high electro-magnetic losses are dominant factor in deciding absorption properties of ferrites in comparison to impedance matching.

Creosote bush (Larrea tridentata) resin increases water demands and reduces energy availability in desert woodrats (Neotoma lepida).

PubMed

Mangione, Antonio M; Dearing, M Denise; Karasov, William H

2004-07-01

Although many plant secondary compounds are known to have serious consequences for herbivores, the costs of processing them are generally unknown. Two potential costs of ingestion and detoxification of secondary compounds are elevation of the minimum drinking water requirement and excretion of energetically expensive metabolites (i.e., glucuronides) in the urine. To address these impacts, we studied the costs of ingestion of resin from creosote bush (Larrea tridentata) on desert woodrats (Neotoma lepida). The following hypotheses were tested: ingestion of creosote resin by woodrats (1) increases minimum water requirement and (2) reduces energy available by increasing fecal and urinary energy losses. We tested the first hypothesis, by measuring the minimum water requirement of woodrats fed a control diet with and without creosote resin. Drinking water was given in decreasing amounts until woodrats could no longer maintain constant body mass. In two separate experiments, the minimum drinking water requirement of woodrats fed resin was higher than that of controls by 18-30% (about 1-1.7 ml/d). We tested several potential mechanisms of increased water loss associated with the increase in water requirement. The rate of fecal water loss was higher in woodrats consuming resin. Neither urinary water nor evaporative water loss was affected by ingestion of resin. Hypothesis 2 was tested by measuring energy fluxes of woodrats consuming control vs. resin-treated diets. Woodrats on a resin diet had higher urinary energy losses and, thus, metabolized a lower proportion of the dietary energy than did woodrats on control diet. Fecal energy excretion was not affected by resin. The excretion of glucuronic acid represented almost half of the energy lost as a consequence of resin ingestion. The increased water requirement and energy losses of woodrats consuming a diet with resin could have notable ecological consequences.

Implications of Liebig’s law of the minimum for tree-ring reconstructions of climate

NASA Astrophysics Data System (ADS)

Stine, A. R.; Huybers, P.

2017-11-01

A basic principle of ecology, known as Liebig’s Law of the Minimum, is that plant growth reflects the strongest limiting environmental factor. This principle implies that a limiting environmental factor can be inferred from historical growth and, in dendrochronology, such reconstruction is generally achieved by averaging collections of standardized tree-ring records. Averaging is optimal if growth reflects a single limiting factor and noise but not if growth also reflects locally variable stresses that intermittently limit growth. In this study a collection of Arctic tree ring records is shown to follow scaling relationships that are inconsistent with the signal-plus-noise model of tree growth but consistent with Liebig’s Law acting at the local level. Also consistent with law-of-the-minimum behavior is that reconstructions based on the least-stressed trees in a given year better-follow variations in temperature than typical approaches where all tree-ring records are averaged. Improvements in reconstruction skill occur across all frequencies, with the greatest increase at the lowest frequencies. More comprehensive statistical-ecological models of tree growth may offer further improvement in reconstruction skill.

When are surface plasmon polaritons excited in the Kretschmann-Raether configuration?

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

Foley, IV, Jonathan J.; Harutyunyan, Hayk; Rosenmann, Daniel

It is widely believed that the reflection minimum in a Kretschmann-Raether experiment results from direct coupling into surface plasmon polariton modes. Our experimental results provide a surprising discrepancy between the leakage radiation patterns of surface plasmon polaritons (SPPs) launched on a layered gold/germanium film compared to the K-R minimum, clearly challenging this belief. We provide definitive evidence that the reflectance dip in K-R experiments does not correlate with excitation of an SPP mode, but rather corresponds to a particular type of perfectly absorbing (PA) mode. Results from rigorous electrodynamics simulations show that the PA mode can only exist under externalmore » driving, whereas the SPP can exist in regions free from direct interaction with the driving field. These simulations show that it is possible to indirectly excite propagating SPPs guided by the reflectance minimum in a K-R experiment, but demonstrate the efficiency can be lower by more than a factor of 3. We find that optimal coupling into the SPP can be guided by the square magnitude of the Fresnel transmission amplitude.« less

When are Surface Plasmon Polaritons Excited in the Kretschmann-Raether Configuration?

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

Foley IV, Jonathan J.; Harutyunyan, Hayk; Rosenmann, Daniel

It is widely believed that the reflection minimum in a Kretschmann-Raether experiment results from direct coupling into surface plasmon polariton modes. Our experimental results provide a surprising discrepancy between the leakage radiation patterns of surface plasmon polaritons (SPPs) launched on a layered gold/germanium film compared to the K-R minimum, clearly challenging this belief. We provide definitive evidence that the reflectance dip in K-R experiments does not correlate with excitation of an SPP mode, but rather corresponds to a particular type of perfectly absorbing (PA) mode. Results from rigorous electrodynamics simulations show that the PA mode can only exist under externalmore » driving, whereas the SPP can exist in regions free from direct interaction with the driving field. These simulations show that it is possible to indirectly excite propagating SPPs guided by the reflectance minimum in a K-R experiment, but demonstrate the efficiency can be lower by more than a factor of 3. We find that optimal coupling into the SPP can be guided by the square magnitude of the Fresnel transmission amplitude.« less

When are surface plasmon polaritons excited in the Kretschmann-Raether configuration?

DOE PAGES

Foley, IV, Jonathan J.; Harutyunyan, Hayk; Rosenmann, Daniel; ...

2015-04-23

It is widely believed that the reflection minimum in a Kretschmann-Raether experiment results from direct coupling into surface plasmon polariton modes. Our experimental results provide a surprising discrepancy between the leakage radiation patterns of surface plasmon polaritons (SPPs) launched on a layered gold/germanium film compared to the K-R minimum, clearly challenging this belief. We provide definitive evidence that the reflectance dip in K-R experiments does not correlate with excitation of an SPP mode, but rather corresponds to a particular type of perfectly absorbing (PA) mode. Results from rigorous electrodynamics simulations show that the PA mode can only exist under externalmore » driving, whereas the SPP can exist in regions free from direct interaction with the driving field. These simulations show that it is possible to indirectly excite propagating SPPs guided by the reflectance minimum in a K-R experiment, but demonstrate the efficiency can be lower by more than a factor of 3. We find that optimal coupling into the SPP can be guided by the square magnitude of the Fresnel transmission amplitude.« less

A generalized vortex theory of the screw propeller and its application

NASA Technical Reports Server (NTRS)

Reissner, Hans

1940-01-01

The vortex theory as presented by the author in earlier papers has been extended to permit the solution of the following problems: (1) the investigation of the relation between thrusts and torque distribution and energy loss as given by the induction of helical vortex sheets and by the parasite drag; (2) the checking of the theorem of Betz of the rigidly behaving helical vortex sheet of minimum induced energy loss; (3) the extension of the theory of the screw propeller of minimum energy loss for the inclusion of parasite-drag distribution along the blades. A simple system of diagrams has been developed to systematize the design of airplane propellers for a wide range of parasite-drag distribution along the blades.

Procedures for ambient-pressure and tympanometric tests of aural acoustic reflectance and admittance in human infants and adults

PubMed Central

Keefe, Douglas H.; Hunter, Lisa L.; Feeney, M. Patrick; Fitzpatrick, Denis F.

2015-01-01

Procedures are described to measure acoustic reflectance and admittance in human adult and infant ears at frequencies from 0.2 to 8 kHz. Transfer functions were measured at ambient pressure in the ear canal, and as down- or up-swept tympanograms. Acoustically estimated ear-canal area was used to calculate ear reflectance, which was parameterized by absorbance and group delay over all frequencies (and pressures), with substantial data reduction for tympanograms. Admittance measured at the probe tip in adults was transformed into an equivalent admittance at the eardrum using a transmission-line model for an ear canal with specified area and ear-canal length. Ear-canal length was estimated from group delay around the frequency above 2 kHz of minimum absorbance. Illustrative measurements in ears with normal function are described for an adult, and two infants at 1 month of age with normal hearing and a conductive hearing loss. The sensitivity of this equivalent eardrum admittance was calculated for varying estimates of area and length. Infant-ear patterns of absorbance peaks aligned in frequency with dips in group delay were explained by a model of resonant canal-wall mobility. Procedures will be applied in a large study of wideband clinical diagnosis and monitoring of middle-ear and cochlear function. PMID:26723319

Intercooler cooling-air weight flow and pressure drop for minimum drag loss

NASA Technical Reports Server (NTRS)

Reuter, J George; Valerino, Michael F

1944-01-01

An analysis has been made of the drag losses in airplane flight of cross-flow plate and tubular intercoolers to determine the cooling-air weight flow and pressure drop that give a minimum drag loss for any given cooling effectiveness and, thus, a maximum power-plant net gain due to charge-air cooling. The drag losses considered in this analysis are those due to (1) the extra drag imposed on the airplane by the weight of the intercooler, its duct, and its supports and (2) the drag sustained by the cooling air in flowing through the intercooler and its duct. The investigation covers a range of conditions of altitude, airspeed, lift-drag ratio, supercharger-pressure ratio, and supercharger adiabatic efficiency. The optimum values of cooling air pressure drop and weight flow ratio are tabulated. Curves are presented to illustrate the results of the analysis.

Automatic genetic optimization approach to two-dimensional blade profile design for steam turbines

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

Trigg, M.A.; Tubby, G.R.; Sheard, A.G.

1999-01-01

In this paper a systematic approach to the optimization of two-dimensional blade profiles is presented. A genetic optimizer has been developed that modifies the blade profile and calculates its profile loss. This process is automatic, producing profile designs significantly faster and with significantly lower loss than has previously been possible. The optimizer developed uses a genetic algorithm to optimize a two-dimensional profile, defined using 17 parameters, for minimum loss with a given flow condition. The optimizer works with a population of two-dimensional profiles with varied parameters. A CFD mesh is generated for each profile, and the result is analyzed usingmore » a two-dimensional blade-to-blade solver, written for steady viscous compressible flow, to determine profile loss. The loss is used as the measure of a profile`s fitness. The optimizer uses this information to select the members of the next population, applying crossovers, mutations, and elitism in the process. Using this method, the optimizer tends toward the best values for the parameters defining the profile with minimum loss.« less

Seasonal patterns in body temperature of free-living rock hyrax (Procavia capensis).

PubMed

Brown, Kelly J; Downs, Colleen T

2006-01-01

Rock hyrax (Procavia capensis) are faced with large daily fluctuations in ambient temperature during summer and winter. In this study, peritoneal body temperature of free-living rock hyrax was investigated. During winter, when low ambient temperatures and food supply prevail, rock hyrax maintained a lower core body temperature relative to summer. In winter body temperatures during the day were more variable than at night. This daytime variability is likely a result of body temperatures being raised from basking in the sun. Body temperatures recorded during winter never fell to low levels recorded in previous laboratory studies. During summer ambient temperatures exceeded the thermoneutral zone of the rock hyrax throughout most of the day, while crevice temperatures remained within the thermoneutral zone of rock hyrax. However, in summer variation in core body temperature was small. Minimum and maximum body temperatures did not coincide with minimum and maximum ambient temperatures. Constant body temperatures were also recorded when ambient temperatures reached lethal limits. During summer it is likely that rock hyrax select cooler refugia to escape lethal temperatures and to prevent excessive water loss. Body temperature of rock hyrax recorded in this study reflects the adaptability of this animal to the wide range of ambient temperatures experienced in its natural environment.

Improved microwave shielding behavior of carbon nanotube-coated PET fabric using plasma technology

NASA Astrophysics Data System (ADS)

Haji, Aminoddin; Semnani Rahbar, Ruhollah; Mousavi Shoushtari, Ahmad

2014-08-01

Four different procedures were conducted to load amine functionalized multiwall carbon nanotube (NH2-MWCNT) onto poly (ethylene terephthalate) (PET) fabric surface to obtain a microwave shielding sample. Plasma treated fabric which was subsequently coated with NH2-MWCNT in the presence of acrylic acid was chosen as the best sample. Surface changes in the PET fabrics were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Wide-angle X-ray diffraction was used to study the crystalline structure of the PET fabric. The microwave shielding performance of the PET fabrics in term of reflection loss was determined using a network analyzer at X-band (8.2-12.4 GHz). The XPS results revealed that the carbon atomic percentage decreased while the oxygen atomic percentage increased when the fabric was plasma treated and coated with NH2-MWCNT. The SEM images showed that the NH2-MWCNTs were homogenously dispersed and individually separated in the surface of fabric. Moreover, the structural studies showed that the crystalline region of the fabrics was not affected by NH2-MWCNT and plasma treatment. The best microwave absorbing properties were obtained from the plasma treated fabric which was then coated with 10% NH2-MWCNT in the presence of acrylic acid. It showed a minimum reflection loss of ∼-18.2 dB about 11 GHz. Proper attachments of NH2-MWCNT on the PET fabric surface was explained in the suggested mechanism in which hydrogen bonding and amide linkage are responsible for the achievement of microwave shielding properties with high durability.

Regulating the tobacco retail environment: beyond reducing sales to minors.

PubMed

Chapman, S; Freeman, B

2009-12-01

The World Health Organization Framework Convention on Tobacco Control (FCTC) has little to say about the regulation of tobacco retailing, with most research and policy debate having been restricted to confining sales to adults and removing advertising displays, including packs. Tobacco retailing is largely unregulated, reflecting the historical regulatory trivialisation of tobacco products, now demonstrably anachronistic with the advent of near global support for the FCTC. This situation contrasts markedly with the regulation of pharmaceuticals, and many other goods and services subject to a wide variety of restrictions. This review proposes that the international tobacco control community should open up debate on retail regulation to examine the suitability of principles long accepted in pharmaceutical regulation. These include: restrictions on the number and location of tobacco retail outlets, the banning of tobacco retail displays, floor (minimum) price controls, restricting the amount of tobacco smokers could purchase over a given time and loss of retail licensure following breaches of any of the conditions of license. It proposes that retail licenses should be heavily restricted and tradable, becoming valuable commercial assets, where the threat of loss or revocation would act as an incentive for strict adherence to the measures proposed.

Constructing Two-, Zero-, and One-Dimensional Integrated Nanostructures: an Effective Strategy for High Microwave Absorption Performance.

PubMed

Sun, Yuan; Xu, Jianle; Qiao, Wen; Xu, Xiaobing; Zhang, Weili; Zhang, Kaiyu; Zhang, Xing; Chen, Xing; Zhong, Wei; Du, Youwei

2016-11-23

A novel "201" nanostructure composite consisting of two-dimensional MoS 2 nanosheets, zero-dimensional Ni nanoparticles and one-dimensional carbon nanotubes (CNTs) was prepared successfully by a two-step method: Ni nanopaticles were deposited onto the surface of few-layer MoS 2 nanosheets by a wet chemical method, followed by chemical vapor deposition growth of CNTs through the catalysis of Ni nanoparticles. The as-prepared 201-MoS 2 -Ni-CNTs composites exhibit remarkably enhanced microwave absorption performance compared to Ni-MoS 2 or Ni-CNTs. The minimum reflection loss (RL) value of 201-MoS 2 -Ni-CNTs/wax composites with filler loading ratio of 30 wt % reached -50.08 dB at the thickness of 2.4 mm. The maximum effective microwave absorption bandwidth (RL< -10 dB) of 6.04 GHz was obtained at the thickness of 2.1 mm. The excellent absorption ability originates from appropriate impedance matching ratio, strong dielectric loss and large surface area, which are attributed to the "201" nanostructure. In addition, this method could be extended to other low-dimensional materials, proving to be an efficient and promising strategy for high microwave absorption performance.

A method for calculating minimum biodiversity offset multipliers accounting for time discounting, additionality and permanence

PubMed Central

Laitila, Jussi; Moilanen, Atte; Pouzols, Federico M

2014-01-01

Biodiversity offsetting, which means compensation for ecological and environmental damage caused by development activity, has recently been gaining strong political support around the world. One common criticism levelled at offsets is that they exchange certain and almost immediate losses for uncertain future gains. In the case of restoration offsets, gains may be realized after a time delay of decades, and with considerable uncertainty. Here we focus on offset multipliers, which are ratios between damaged and compensated amounts (areas) of biodiversity. Multipliers have the attraction of being an easily understandable way of deciding the amount of offsetting needed. On the other hand, exact values of multipliers are very difficult to compute in practice if at all possible. We introduce a mathematical method for deriving minimum levels for offset multipliers under the assumption that offsetting gains must compensate for the losses (no net loss offsetting). We calculate absolute minimum multipliers that arise from time discounting and delayed emergence of offsetting gains for a one-dimensional measure of biodiversity. Despite the highly simplified model, we show that even the absolute minimum multipliers may easily be quite large, in the order of dozens, and theoretically arbitrarily large, contradicting the relatively low multipliers found in literature and in practice. While our results inform policy makers about realistic minimal offsetting requirements, they also challenge many current policies and show the importance of rigorous models for computing (minimum) offset multipliers. The strength of the presented method is that it requires minimal underlying information. We include a supplementary spreadsheet tool for calculating multipliers to facilitate application. PMID:25821578

Minimum Standards for Tribal Child Care Centers.

ERIC Educational Resources Information Center

Administration on Children, Youth, and Families (DHHS), Washington, DC. Child Care Bureau.

These minimum standards for tribal child care centers are being issued as guidance. An interim period of at least 1 year will allow tribal agencies to identify implementation issues, ensure that the standards reflect tribal needs, and guarantee that the standards provide adequate protection for children. The standards will be issued as regulations…

77 FR 1723 - Proposed Concession Contract for Shenandoah National Park-Alternative Formula for Calculating...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-11

... we include in concession contracts a franchise fee payable to the Government that is based upon... establish the required minimum franchise fee for the new contract, that fee will reflect speculative... concessioner offers to meet or exceed the minimum franchise fee that we would establish under the standard LSI...

Effect of reflection losses on stationary dielectric-filled nonimaging concentrators

NASA Astrophysics Data System (ADS)

Madala, Srikanth; Boehm, Robert F.

2016-10-01

The effect of Fresnel reflection and total internal reflection (TIR) losses on the performance parameters in refractive solar concentrators has often been downplayed because most refractive solar concentrators are traditionally the imaging type, yielding a line or point image on the absorber surface when solely interacted with paraxial etendue ensured by solar tracking. Whereas, with refractive-type nonimaging solar concentrators that achieve two-dimensional (rectangular strip) focus or three-dimensional (circular or elliptical) focus through interaction with both paraxial and nonparaxial etendue within the acceptance angle, the Fresnel reflection and TIR losses are significant as they will affect the performance parameters and, thereby, energy collection. A raytracing analysis has been carried out to illustrate the effects of Fresnel reflection and TIR losses on four different types of stationary dielectric-filled nonimaging concentrators, namely V-trough, compound parabolic concentrator, compound elliptical concentrator, and compound hyperbolic concentrator. The refractive index (RI) of a dielectric fill material determines the acceptance angle of a solid nonimaging collector. Larger refractive indices yield larger acceptance angles and, thereby, larger energy collection. However, they also increase the Fresnel reflection losses. This paper also assesses the relative benefit of increasing RI from an energy collection standpoint.

Maximum reflectance and transmittance of films coated with gapped graphene in the context of the Dirac model

NASA Astrophysics Data System (ADS)

Klimchitskaya, G. L.; Mostepanenko, V. M.

2018-06-01

The analytic expressions for the maximum and minimum reflectances of optical films coated with gapped graphene are derived in the application region of the Dirac model taking into account multiple reflections. The respective film thicknesses are also found. In so doing the film material is described by the frequency-dependent index of refraction and graphene by the polarization tensor defined along the real frequency axis. The developed formalism is illustrated by an example of the graphene-coated film made of amorphous silica. Numerical computations of the maximum and minimum reflectances and respective film thicknesses are performed at room temperature in two frequency regions belonging to the near-infrared and far-infrared domains. It is shown that in the far-infrared domain the graphene coating has a profound effect on the values of maximum reflectance and respective film thickness leading to a relative increase in their values by up to 65% and 50%, respectively. The maximum transmittance of a graphene-coated film of appropriately chosen thickness is shown to exceed 90%. Possible applications of the obtained results are discussed.

In-Scene-Based Atmospheric Correction of Uncalibrated VISible-SWIR (VIS-SWIR) Hyper- and Multispectral Imagery

DTIC Science & Technology

2008-01-01

resolution , it is very likely that near-zero reflectance values exist in each spectral channel, corresponding to the minimum data values in the scene...radiometrically uncalibrated data. Quite good agreement was previously demonstrated for the retrieved pixel spectral reflectances between QUAC and the physics...precluding the use of physics-based codes to retrieve surface reflectance. The ability to retrieve absolute spectral reflectances from such sensors

Easily Dispersible NiFe2O4/RGO Composite for Microwave Absorption Properties in the X-Band

NASA Astrophysics Data System (ADS)

Bateer, Buhe; Zhang, Jianjao; Zhang, Hongchen; Zhang, Xiaochen; Wang, Chunyan; Qi, Haiqun

2018-01-01

Composites with good dispersion and excellent microwave absorption properties have important applications. Therefore, an easily dispersible NiFe2O4/reduced graphene oxide (RGO) composite has been prepared conveniently through a simple hydrothermal method. Highly crystalline, small size (about 7 nm) monodispersed NiFe2O4 nanoparticles (NPs) are evenly distributed on the surface of RGO. The microwave absorbability revealed that the NiFe2O4/RGO composite exhibits excellent microwave absorption properties in the X-band (8-12 GHz), and the minimum reflection loss of the NiFe2O4/RGO composite is -27.7 dB at 9.2 GHz. The NiFe2O4/RGO composite has good dispersibility in nonpolar solvent, which facilitates the preparation of stable commercial microwave absorbing coatings. It can be a promising candidate for lightweight microwave absorption materials in many application fields.

CaCu3Ti4O12 particles and MWCNT-filled microwave absorber with improved microwave absorption by FSS incorporation

NASA Astrophysics Data System (ADS)

Qing, Yuchang; Yang, Zhaoning; Wen, Qinlong; Luo, Fa

2016-07-01

Multi-walled carbon nanotube (MWCNTs)- and CaCu3Ti4O12 (CCTO) particle-filled epoxy microwave absorbing coatings were prepared, and their electromagnetic properties and reflection loss (RL) were investigated in the frequency range 8.2-12.4 GHz. The microstructures of these coatings exhibit a uniform dispersion of MWCNTs and CCTO particles in the matrix. The value and frequency dependency of complex permittivity of such coatings enhanced with increasing MWCNT content. Frequency-selective surface was used to improve their microwave absorption (both the operating bandwidth and minimum RL) without increasing the absorber thickness. Such absorber showed high microwave absorbing performance, and the bandwidth of the RL below -8 dB (more than 84.1 % absorption) can be obtained in the whole X-band with a thickness of 1.5 mm.

Templated synthesis of highly ordered mesoporous cobalt ferrite and its microwave absorption properties

NASA Astrophysics Data System (ADS)

Li, Guo-Min; Wang, Lian-Cheng; Xu, Yao

2014-08-01

Based on the nanocasting strategy, highly ordered mesoporous CoFe2O4 is synthesized via the ‘two-solvent’ impregnation method using a mesoporous SBA-15 template. An ordered two-dimensional (P6mm) structure is preserved for the CoFe2O4/SBA-15 composite after the nanocasting. After the SBA-15 template is dissolved by NaOH solution, a mesoporous structure composed of aligned nanoparticles can be obtained, and the P6mm structure of the parent SBA-15 is preserved. With a high specific surface area (above 90 m2/g) and ferromagnetic behavior, the obtained material shows potential in light weight microwave absorption application. The minimum reflection loss (RL) can reach -18 dB at about 16 GHz with a thickness of 2 mm and the corresponding absorption bandwidth is 4.5 GHz.

A simple, one-step hydrothermal approach to durable and robust superparamagnetic, superhydrophobic and electromagnetic wave-absorbing wood

NASA Astrophysics Data System (ADS)

Wang, Hanwei; Yao, Qiufang; Wang, Chao; Fan, Bitao; Sun, Qingfeng; Jin, Chunde; Xiong, Ye; Chen, Yipeng

2016-10-01

In this work, lamellar MnFe2O4 was successfully planted on a wood surface through the association of hydrogen bonds via the one-pot hydrothermal method. Simultaneously, the fluoroalkylsilane (FAS-17) on the surface of the MnFe2O4 layer formed long-chain or network macromolecules through a poly-condensation process and provided a lower surface energy on the wood surface. The MnFe2O4/wood composite (FMW) presented superior superparamagnetism, superhydrophobicity and electromagnetic wave absorption performance. The results indicated a saturation magnetization of the FMW with excellent superparamagnetism of 28.24 emu·g-1. The minimum value of reflection loss of the FMW reached -8.29 dB at 16.39 GHz with a thickness of 3 mm. Even after mechanical impact and exposure to corrosive liquids, the FMW still maintained a superior superhydrophobicity performance.

Electromagnetic and Microwave Absorption Properties of Carbonyl Tetrapod-Shaped Zno Nanostructures Composite Coatings

NASA Astrophysics Data System (ADS)

Yu, Haibo; Qin, Hui; Huang, Yunhua

2012-08-01

CIP/T-ZnO/EP composite coatings with carbonyl iron powders (CIP) and tetrapodshaped ZnO (T-ZnO) nanostructures as absorbers, and epoxy resin (EP) as matrix were prepared. The complex permittivity, permeability and microwave absorption properties of the coatings were investigated in the frequency range of 2-18 GHz. The effects of the weight ratio (CIP/T-ZnO/EP), the thickness and the solidification temperature on microwave absorption properties were discussed. When the weight ratio (CIP/TZnO/ EP), the thickness and the solidification temperature is 28:2:22, 1.8 mm, and 10°C, respectively, the optimal wave absorption with the minimum reflection loss (RL) value of -22.38 dB at 15.67 GHz and the bandwidth (RL<-10 dB) of 5.74 GHz was obtained, indicating that the composite coatings may have a promising application in Ku-band (12-18 GHz).

Arthroscopic fixation of acute acromioclavicular joint disruption with TightRope™: Outcome and complications after minimum 2 (2-5) years follow-up.

PubMed

Zhang, Li-Feng; Yin, Bo; Hou, Su; Han, Bing; Huang, De-Fa

2017-01-01

To evaluate the midterm results of arthroscopic reconstruction of acute acromioclavicular (AC) joint disruption using TightRope™ system. We retrospectively assess the results of 24 patients of acute AC joint dislocation who were operated using TightRope system. Constant and University of California, Los Angeles (UCLA) scores and coracoclavicular distance were calculated pre- and postoperatively. Data was entered into MS excel and analyzed using the SPSS version 17. The mean follow-up was 39.45 months. Constant and UCLA scores were significantly increased postoperatively. Six patients had partial loss of reduction within 3-6 months and two patients had a failure of construct. Constant score was significantly lower in these patients. TightRope reconstruction of the AC joint is a reproducible and safe alternative to many other techniques of AC joint reconstruction. Early subluxation remains a concern and may reflect the need for technique modification.

Bandwidth enhancement in microwave absorption of binary nanocomposite ferrites hollow microfibers.

PubMed

Song, Fuzhan; Shen, Xiangqian; Yang, Xinchun; Meng, Xianfeng; Xiang, Jun; Liu, Ruijiang; Dong, Mingdong

2013-04-01

The binary Ba0.5Sr0.5Fe12O19 (BSFO)/Ni0.5Zn0.5Fe2O4 (NZFO) nanocomposite ferrites hollow microfibers with high aspect ratios have been prepared by the gel precursor transformation process. These microfibers possess a high specific surface area about 45.2 m2 g(-1), and a ratio of the hollow diameter to the fiber diameter estimated about 5/7. The binary nanocomposite ferrites are formed after the precursor calcined at 750 degrees C for 3 h. Their minimum reflection loss (RL) is -38.1 dB at 10.4 GHz. The microwave absorption bandwidth with RL value exceeding -20 dB covers the whole X-band (8.2-12.4 GHz) and Ku-band (12.4-18 GHz). This enhancement in microwave absorption can be attributed to the exchange-coupling interaction, interfacial polarization and small size effect in nanocomposite hollow microfibers.

The MUCHFUSS photometric campaign

NASA Astrophysics Data System (ADS)

Schaffenroth, V.; Geier, S.; Heber, U.; Gerber, R.; Schneider, D.; Ziegerer, E.; Cordes, O.

2018-06-01

Hot subdwarfs (sdO/Bs) are the helium-burning cores of red giants, which have lost almost all of their hydrogen envelope. This mass loss is often triggered by common envelope interactions with close stellar or even substellar companions. Cool companions like late-type stars or brown dwarfs are detectable via characteristic light-curve variations like reflection effects and often also eclipses. To search for such objects, we obtained multi-band light curves of 26 close sdO/B binary candidates from the MUCHFUSS project with the BUSCA instrument. We discovered a new eclipsing reflection effect system (P = 0.168938 d) with a low-mass M dwarf companion (0.116 M⊙). Three more reflection effect binaries found in the course of the campaign have already been published; two of them are eclipsing systems, and in one system only showing the reflection effect but no eclipses, the sdB primary is found to be pulsating. Amongst the targets without reflection effect a new long-period sdB pulsator was discovered and irregular light variations were found in two sdO stars. The found light variations allowed us to constrain the fraction of reflection effect binaries and the substellar companion fraction around sdB stars. The minimum fraction of reflection effect systems amongst the close sdB binaries might be greater than 15% and the fraction of close substellar companions in sdB binaries may be as high as 8.0%. This would result in a close substellar companion fraction to sdB stars of about 3%. This fraction is much higher than the fraction of brown dwarfs around possible progenitor systems, which are solar-type stars with substellar companions around 1 AU, as well as close binary white dwarfs with brown dwarf companions. This might suggest that common envelope interactions with substellar objects are preferentially followed by a hot subdwarf phase.

Design of MSR primary circuit with minimum pressure losses

NASA Astrophysics Data System (ADS)

Noga, Tomáš; Žitek, Pavel; Valenta, Václav

This article describes a design of a MSR primary circuit with minimum pressure losses. It includes a brief description of this type of a reactor and its integral layout, properties, purpose, etc. The objective of this paper is to define problems of pressure losses calculation and to design a proper device for a primary circuit of MSR reactor, including its basic dimensions. Thanks to this, it can become an initial project for a construction of a real piece of work. This is the main contribution of the carried out study. Of course, this article is not a detailed solution, but it points out facts and problems, which future designers may have to face. The further step of our work will be a reconstruction of the current experiment for a two-stage flowing.

Comprehensive Understanding for Vegetated Scene Radiance Relationships

NASA Technical Reports Server (NTRS)

Kimes, D. S.; Deering, D. W.

1984-01-01

The improvement of our fundamental understanding of the dynamics of directional scattering properties of vegetation canopies through analysis of field data and model simulation data is discussed. Directional reflectance distributions spanning the entire existance hemisphere were measured in two field studies; one using a Mark III 3-band radiometer and one using rapid scanning bidirectional field instrument called PARABOLA. Surfaces measured included corn, soybeans, bare soils, grass lawn, orchard grass, alfalfa, cotton row crops, plowed field, annual grassland, stipa grass, hard wheat, salt plain shrubland, and irrigated wheat. Some structural and optical measurements were taken. Field data show unique reflectance distributions ranging from bare soil to complete vegetation canopies. Physical mechanisms causing these trends are proposed based on scattering properties of soil and vegetation. Soil exhibited a strong backscattering peak toward the Sun. Complete vegetation exhibited a bowl distribution with the minimum reflectance near nadir. Incomplete vegetation canopies show shifting of the minimum reflectance off of nadir in the forward scattering direction because both the scattering properties or the vegetation and soil are observed.

Far-UV, visible, and near-IR reflectance spectra of frosts of H2O, CO2, NH3 and SO2

NASA Technical Reports Server (NTRS)

Hapke, B.; Wells, E.; Wagner, J.; Partlow, W.

1981-01-01

Measurements in the 0.1-2.5 micron range are presented for the reflectance spectra of the frosts of several volatiles pertinent to the study of comet nuclei. The frost spectra have distinctive features permitting their identification by spectroscopic reflectance remote sensing, notably in the far UV. It is found that: (1) H2O has a minimum at 0.16 microns and a maximum at 0.13 microns; (2) CO2 has minima near 0.21, 0.18 and 0.125 microns, with maxima at 0.19, 0.135 and 0.120 microns; (3) NH3 is bright at wavelengths longer than 0.21 microns, where reflectance drops to a value of only a few per cent at shorter wavelengths; (4) SO2 has a sharp drop at 0.32 microns, with a minimum at 0.18 microns and a maximum at 0.13 microns. The features in the frost spectra largely correspond to absorption line bands in the gas phase.

Inhomogeneous models of the Venus clouds containing sulfur

NASA Technical Reports Server (NTRS)

Smith, S. M.; Pollack, J. B.; Giver, L. P.; Cuzzi, J. N.; Podolak, M.

1979-01-01

Based on the suggestion that elemental sulfur is responsible for the yellow color of Venus, calculations are compared at 3.4 microns of the reflectivity phase function of two sulfur containing inhomogeneous cloud models with that of a homogeneous model. Assuming reflectivity observations with 25% or less total error, comparison of the model calculations leads to a minimum detectable mass of sulfur equal to 7% of the mass of sulfuric acid for the inhomogeneous drop model. For the inhomogeneous cloud model the comparison leads to a minimum detectable mass of sulfur between 17% and 38% of the mass of the acid drops, depending upon the actual size of the large particles. It is concluded that moderately accurate 3.4 microns reflectivity observations are capable of detecting quite small amounts of elemental sulfur at the top of the Venus clouds.

Droplet squeezing through a narrow constriction: Minimum impulse and critical velocity

NASA Astrophysics Data System (ADS)

Zhang, Zhifeng; Drapaca, Corina; Chen, Xiaolin; Xu, Jie

2017-07-01

Models of a droplet passing through narrow constrictions have wide applications in science and engineering. In this paper, we report our findings on the minimum impulse (momentum change) of pushing a droplet through a narrow circular constriction. The existence of this minimum impulse is mathematically derived and numerically verified. The minimum impulse happens at a critical velocity when the time-averaged Young-Laplace pressure balances the total minor pressure loss in the constriction. Finally, numerical simulations are conducted to verify these concepts. These results could be relevant to problems of energy optimization and studies of chemical and biomedical systems.

Recent Immigrants as Labor Market Arbitrageurs: Evidence from the Minimum Wage.

PubMed

Cadena, Brian C

2014-03-01

This paper investigates the local labor supply effects of changes to the minimum wage by examining the response of low-skilled immigrants' location decisions. Canonical models emphasize the importance of labor mobility when evaluating the employment effects of the minimum wage; yet few studies address this outcome directly. Low-skilled immigrant populations shift toward labor markets with stagnant minimum wages, and this result is robust to a number of alternative interpretations. This mobility provides behavior-based evidence in favor of a non-trivial negative employment effect of the minimum wage. Further, it reduces the estimated demand elasticity using teens; employment losses among native teens are substantially larger in states that have historically attracted few immigrant residents.

Analysis of Ni-HYDRIDE Thin Film after Surface Plasmon Generation by Laser Technique

NASA Astrophysics Data System (ADS)

Violante, V.; Castagna, E.; Sibilia, C.; Paoloni, S.; Sarto, F.

2005-12-01

A nickel hydride thin film was studied by the attenuated total reflection method. The differences in behavior between a "black" film, and a pure nickel film "blank," are shown. The black nickel hydride film has been obtained by a short electrolysis with 1 M Li2SO4 electrolyte in light water, A shift in the minimum of the observed reflected light occurs, together with a change in the minimum shape (i.e. its half-height width increases). These two phenomenon are due to the change in the electronic band structure of the metal induced by electrons added to the lattice by hydrogen. The change of the electronic structure, revealed by the laser coupling conditions, leads us to consider that a hydride phase was created. Both the blank (not hydrogenated) and black (hydrogenated) specimens were taken under He-Ne laser beam at the reflectance minimum angle for about three hours. A SIMS analysis was also implemented to reveal differences in the isotopic composition of Cu, as marker element between the blank and black films, in order to study the coupled effect of electrolysis and plasmon-polariton excitation on LENR processes in condensed matter.

The Minimum Data Set Depression Quality Indicator: Does It Reflect Differences in Care Processes?

ERIC Educational Resources Information Center

Simmons, S.F.; Cadogan, M.P.; Cabrera, G.R.; Al-Samarrai, N.R.; Jorge, J.S.; Levy-Storms, L.; Osterweil, D.; Schnelle, J.F.

2004-01-01

Purpose. The objective of this work was to determine if nursing homes that score differently on prevalence of depression, according to the Minimum Data Set (MDS) quality indicator, also provide different processes of care related to depression. Design and Methods. A cross-sectional study with 396 long-term residents in 14 skilled nursing…

75 FR 54179 - National Park Service Concession Contracts; Implementation of Alternative Valuation Formula for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-03

... reflects in part the requirement of the 1998 Act that NPS include in concession contracts a franchise fee... consequence, if the NPS were to establish the required minimum franchise fee for the new contract under the... a prospective concessioner offers to meet or exceed the minimum franchise fee established by NPS...

Homeostasis in leaf water potentials on leeward and windward sides of desert shrub crowns: water loss control vs. high hydraulic efficiency.

PubMed

Iogna, Patricia A; Bucci, Sandra J; Scholz, Fabián G; Goldstein, Guillermo

2013-11-01

Phenotypic plasticity in morphophysiological leaf traits in response to wind was studied in two dominant shrub species of the Patagonian steppe, used as model systems for understanding effects of high wind speed on leaf water relations and hydraulic properties of small woody plants. Morpho-anatomical traits, hydraulic conductance and conductivity and water relations in leaves of wind-exposed and protected crown sides were examined during the summer with nearly continuous high winds. Although exposed sides of the crowns were subjected to higher wind speeds and air saturation deficits than the protected sides, leaves throughout the crown had similar minimum leaf water potential (ΨL). The two species were able to maintain homeostasis in minimum ΨL using different physiological mechanisms. Berberis microphylla avoided a decrease in the minimum ΨL in the exposed side of the crown by reducing water loss by stomatal control, loss of cell turgor and low epidermal conductance. Colliguaja integerrima increased leaf water transport efficiency to maintain transpiration rates without increasing the driving force for water loss in the wind-exposed crown side. Leaf physiological changes within the crown help to prevent the decrease of minimum ΨL and thus contribute to the maintenance of homeostasis, assuring the hydraulic integrity of the plant under unfavorable conditions. The responses of leaf traits that contribute to mechanical resistance (leaf mass per area and thickness) differed from those of large physiological traits by exhibiting low phenotypic plasticity. The results of this study help us to understand the unique properties of shrubs which have different hydraulic architecture compared to trees.

Refractive Index Dispersion in Ternary Germanate Glasses

NASA Astrophysics Data System (ADS)

Sakaguchi, Shigeki; Todoroki, Shinichi; Rigout, Nathalie

1995-10-01

The refractive index dispersion in germanate oxyfluoride glasses of GeO2-P2O5-MF2 (M=Ca, Zn), which are developed for optical fiber application, is investigated in the 0.4-4 µ m wavelength range by the minimum deviation method. The prepared glasses have a GeO2 content varying from 80 to 30 mol%. The dispersion curves for these glasses tend to shift to shorter wavelengths as the GeO2 content is decreased. Material dispersions are also derived from the refractive index measurements and the zero-material dispersion wavelengths (λ0) are found in the vicinity of 1.5 µ m. On the basis of the empirical relationship between λ0 and the minimum loss wavelength (λ0), the λ min values are located at around 1.8 µ m. A minimum loss of as low as 0.08 dB/km is expected for the present germanate glasses.

Differential Frequency Hopping (DFH) Modulation for Underwater Acoustic Communications and Networking

DTIC Science & Technology

2009-10-09

trains the coefficients c of a finite impulse response (FIR) filter by gradient descent. The coefficients at iteration k + 1 are computed with the update... absorption . Figure 9 shows the reflection loss as a function of grazing angle for this bottom model. Note that below 30◦ this bottom model predicts...less than 1 dB loss per ray bounce. 11 Figure 9: Jackson bottom reflection loss for sand at 15 kHz Absorption Loss The absorption loss in the medium was

Linking rights and standards: the process of developing "rights-based" minimum standards on food security, nutrition and food aid.

PubMed

Young, Helen; Taylor, Anna; Way, Sally-Anne; Leaning, Jennifer

2004-06-01

This article examines the recent revision of the Sphere Minimum Standards in disaster response relating to food security, nutrition and food aid. It describes how the revision attempted to incorporate the principles of the Humanitarian Charter, as well as relevant human rights principles and values into the Sphere Minimum Standards. The initial aim of the revision was to ensure that the Sphere Minimum Standards better reflected the principles embodied in the Humanitarian Charter. This was later broadened to ensure that key legal standards and principles from human rights and humanitarian law were considered and also incorporated, in part to fill the "protection gap" within the existing standards. In relation to the food security, nutrition and food aid standards, it was agreed by participants in the process that the human right to adequate food and freedom from hunger should be incorporated. In relation to more general principles underlying the Humanitarian Charter, itself drawn largely from human rights and humanitarian law, it was agreed that there was a need to strengthen "protection" elements within the standards and a need to incorporate the basic principles of the right to life with dignity, non-discrimination, impartiality and participation, as well as to explore the relevance of the concept of the progressive realisation of the right to food. The questions raised in linking rights to operational standards required thought, on the one hand, about whether the technical standards reflected a deep understanding of the values expressed within the legal instruments, and whether the existing standards were adequate in relation to those legal rights. On the other hand, it also required reflection on how operational standards like Sphere could give concrete content to human rights, such as the right to food and the right to be free from hunger. However, there remain challenges in examining what a rights-based approach will mean in terms of the role of humanitarian agencies as duty-bearers of rights, given that the primary responsibility rests with state governments. It will also require reflection on the modes and mechanisms of accountability that are brought to bear in ensuring the implementation of the Minimum Standards.

Large-Area Subwavelength Aperture Arrays Fabricated Using Nanoimprint Lithography

DOE PAGES

Skinner, J. L.; Hunter, L. L.; Talin, A. A.; ...

2008-07-29

In this paper, we report on the fabrication and characterization of large-area 2-D square arrays of subwavelength holes in Ag and Al films. Fabrication is based on thermal nanoimprint lithography and metal evaporation, without the need for etching, and is compatible with low-cost, large-scale production. Reflectance spectra for these arrays display an intensity minimum whose amplitude, center wavelength, and line width depend on the geometry of the array and the reflectivity of the metal film. By placing various fluids in contact with the subwavelength aperture arrays, we observe that the center wavelength of the reflectance minimum varies linearly with themore » refractive index of the fluid with a sensitivity of over 500 nm per refractive index unit. Lastly, the surface plasmon theory is used to predict sensitivities to refractive index change with accuracies better than 0.5%.« less

Deepening Minimums in Phase Space Density as an Evidence of the Localied Loss of Electrons by EMIC waves

NASA Astrophysics Data System (ADS)

Shprits, Y.; Aseev, N.; Drozdov, A.; Kellerman, A. C.; Usanova, M.

2017-12-01

Recent observations and modeling provided significant improvements in our understanding of the energization mechanisms for the electrons in the radiation belts. However, loss processes remain poorly understood. In this study we present analysis of the evolution of electron radial profiles of fluxes, pitch angle and energy distributions. Our modeling and observational results show that different loss mechanisms are operational at different energies. Global simulations at all energies, radial distances, and pitch angels are compared to Van Allen Probes observations of electron fluxes. VERB 3D model including various waves is capable of reproducing the dynamics of pitch angle distributions and energy spectra, demonstrating which loss mechanisms dominate at different energies. Analysis of the profiles of phase space density provides additional confirmation for our conclusions and presents a novel technique that identifies the region of intense local loss due to EMIC wave scattering. This technique allows us to identify the minimum energy affected by the EMIC loss and the location of the location of the EMIC-induced loss. Further comparison with theoretical estimates confirms that 1-2 MeV electrons cannot be effectively scattered by EMIC waves and most pronounced effect of EMIC waves is seen above 4MeV.

Recent Immigrants as Labor Market Arbitrageurs: Evidence from the Minimum Wage*

PubMed Central

Cadena, Brian C.

2014-01-01

This paper investigates the local labor supply effects of changes to the minimum wage by examining the response of low-skilled immigrants’ location decisions. Canonical models emphasize the importance of labor mobility when evaluating the employment effects of the minimum wage; yet few studies address this outcome directly. Low-skilled immigrant populations shift toward labor markets with stagnant minimum wages, and this result is robust to a number of alternative interpretations. This mobility provides behavior-based evidence in favor of a non-trivial negative employment effect of the minimum wage. Further, it reduces the estimated demand elasticity using teens; employment losses among native teens are substantially larger in states that have historically attracted few immigrant residents. PMID:24999288

Near zero reflection by nanostructured anti-reflection coating design for Si substrates

NASA Astrophysics Data System (ADS)

Al-Fandi, Mohamed; Makableh, Yahia F.; Khasawneh, Mohammad; Rabady, Rabi

2018-05-01

The nanostructure design of near zero reflection coating for Si substrates by using ZnO Nanoneedles (ZnONN) is performed and optimized for the visible spectral range. The design investigates the ZnONN tip to body ratio effect on the anti-reflection coating properties. Different tip to body ratios are used on Si substrates. Around zero reflection is achieved by the Nanoneedles structure design presented in this work, leading to minimal reflection losses from the Si surface. The current design evolves a solution to optical losses and surface contamination effects associated with Si solar cells.

The Minimum Data Set Prevalence of Restraint Quality Indicator: Does It Reflect Differences in Care?

ERIC Educational Resources Information Center

Schnelle, John F.; Bates-Jensen, Barbara M.; Levy-Storms, Lene; Grbic, Valena; Yoshii, June; Cadogan, Mary; Simmons, Sandra F.

2004-01-01

Purpose: This study investigated whether the use of restraining devices and related measures of care quality are different in nursing homes that score in the upper and lower quartiles on the Minimum Data Set (MDS) "prevalence of restraint" quality indicator, which assesses daily use of restraining devices when residents are out of bed. Design and…

Effect of aperiodicity on the broadband reflection of silicon nanorod structures for photovoltaics.

PubMed

Lin, Chenxi; Huang, Ningfeng; Povinelli, Michelle L

2012-01-02

We carry out a systematic numerical study of the effects of aperiodicity on silicon nanorod anti-reflection structures. We use the scattering matrix method to calculate the average reflection loss over the solar spectrum for periodic and aperiodic arrangements of nanorods. We find that aperiodicity can either improve or deteriorate the anti-reflection performance, depending on the nanorod diameter. We use a guided random-walk algorithm to design optimal aperiodic structures that exhibit lower reflection loss than both optimal periodic and random aperiodic structures.

Ultra-low loss fully-etched grating couplers for perfectly vertical coupling compatible with DUV lithography tools

NASA Astrophysics Data System (ADS)

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.

An experimental study of the reflection from spherical and flat ended cylindrical targets suitable for fetal Doppler performance assessment.

PubMed

Preston, R C; Bond, A D

1997-01-01

The performance of small-diameter targets suitable for use as oscillating targets for testing the sensitivity of Doppler fetal heartbeat detectors has been systematically studied. Experimental results are presented in the 1.6-3.0 MHz frequency range for the plane-wave reflection loss for a total of 16 targets: spherical balls made of stainless steel; hemispherical-ended rods made of PTFE; and flat-ended rods made of stainless steel, PTFE, polycarbonate, and tungsten carbide. Results show that the fine-structure variation of reflection loss with frequency is greatest in the case of spherical ball targets and least for flat-ended targets. It has been shown that, providing care is taken during manufacture, the reflection loss from a flat-ended target can be predicted using a simple theory based on a plane disc reflector. Tungsten carbide targets consisting of a long rod with a diameter of 1.6 mm tapered down to a cylindrical flat end with a diameter of 0.4, 0.5, and 0.6 mm have been shown to provide reflection losses of between 60 and 40 dB, and to have a smooth variation of reflection loss with frequency. They can also be manufactured in a form that allows no significant interference from the supporting structure and, therefore, are ideal targets to meet the requirements of International Electrotechnical Commission 1266:1995.

Improving the Electromagnetic Wave Absorption Properties of the Layered MoS2 by Cladding with Ni Nanoparticles

NASA Astrophysics Data System (ADS)

Zhang, Zilong; Wang, Zilin; Heng, Liuyang; Wang, Shuai; Chen, Xiqiao; Fu, Xiquan; Zou, Yanhong; Tang, Zhixiang

2018-05-01

MoS2 is a promising material with microwave absorption performance due to its high dielectric properties and low density. However, pure MoS2 is non-magnetic and has a bad impedance matching characteristic. In this study we prepared the Ni/MoS2 nanocomposites by cladding the MoS2 micrometer slices with magnetic Ni nanoparticles. Our results show that the microwave absorption properties of Ni/MoS2 nanocomposites have been improved obviously compared with the pure MoS2. Because of the introduction of Ni particles, the permeability of the nanocomposites has been turned from one to a complex, indicating a newly added magnetic loss. Meanwhile, the big gap between the permittivity and permeability of the Ni/MoS2 nanocomposites has been properly narrowed, which suggests an improved impedance matching. Moreover, the dielectric Cole-Cole semicircle shows that there are more Debye relaxation processes for the Ni/MoS2 nanocomposites, which further enhances the dielectric loss. Due to its improved electromagnetic properties, the minimum reflection loss (RL) value of the Ni/MoS2 nanocomposites with 60 wt % loading reaches -55 dB and the absorption bandwidth (<-10 dB) is up to 4.0 GHz (10.8-14.8 GHz) with a matching thickness of 1.5 mm. The results provide an excellent candidate for microwave absorbing materials with a broad effective absorption bandwidth at thin thicknesses.

Large amplitude MHD waves upstream of the Jovian bow shock

NASA Technical Reports Server (NTRS)

Goldstein, M. L.; Smith, C. W.; Matthaeus, W. H.

1983-01-01

Observations of large amplitude magnetohydrodynamics (MHD) waves upstream of Jupiter's bow shock are analyzed. The waves are found to be right circularly polarized in the solar wind frame which suggests that they are propagating in the fast magnetosonic mode. A complete spectral and minimum variance eigenvalue analysis of the data was performed. The power spectrum of the magnetic fluctuations contains several peaks. The fluctuations at 2.3 mHz have a direction of minimum variance along the direction of the average magnetic field. The direction of minimum variance of these fluctuations lies at approximately 40 deg. to the magnetic field and is parallel to the radial direction. We argue that these fluctuations are waves excited by protons reflected off the Jovian bow shock. The inferred speed of the reflected protons is about two times the solar wind speed in the plasma rest frame. A linear instability analysis is presented which suggests an explanation for many of the observed features of the observations.

Sediment Acoustics: Wideband Model, Reflection Loss and Ambient Noise Inversion

DTIC Science & Technology

2010-01-01

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Sediment acoustics : Wideband model , reflection loss and...Physically sound models of acoustic interaction with the ocean floor including penetration, reflection and scattering in support of MCM and ASW needs...OBJECTIVES (1) Consolidation of the BIC08 model of sediment acoustics , its verification in a variety of sediment types, parameter reduction and

25 CFR 542.19 - What are the minimum internal control standards for accounting?

Code of Federal Regulations, 2013 CFR

2013-04-01

...; (3) Individual and statistical game records to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop by each table game, and to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop for each type of table game, by...

25 CFR 542.19 - What are the minimum internal control standards for accounting?

Code of Federal Regulations, 2014 CFR

2014-04-01

...; (3) Individual and statistical game records to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop by each table game, and to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop for each type of table game, by...

25 CFR 542.19 - What are the minimum internal control standards for accounting?

Code of Federal Regulations, 2010 CFR

2010-04-01

...; (3) Individual and statistical game records to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop by each table game, and to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop for each type of table game, by...

25 CFR 542.19 - What are the minimum internal control standards for accounting?

Code of Federal Regulations, 2011 CFR

2011-04-01

...; (3) Individual and statistical game records to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop by each table game, and to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop for each type of table game, by...

25 CFR 542.19 - What are the minimum internal control standards for accounting?

Code of Federal Regulations, 2012 CFR

2012-04-01

...; (3) Individual and statistical game records to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop by each table game, and to reflect statistical drop, statistical win, and the percentage of statistical win to statistical drop for each type of table game, by...

Smart absorbing property of composites with MWCNTs and carbonyl iron as the filler

NASA Astrophysics Data System (ADS)

Xu, Yonggang; Yuan, Liming; Cai, Jun; Zhang, Deyuan

2013-10-01

A smart absorbing composite was prepared by mixing silicone rubber, multi-walled carbon nanotubes (MWCNTs) and flaky carbonyl iron particles (CIPs) in a two-roll mixer. The complex permittivity and permeability of composites with variable compression strain was measured by the transmission method and dc electric conductivity was measured by the standard four-point contact method, then the reflection loss (RL) could be calculated to evaluate the microwave absorbing ability. The results showed that the applied compression strain made the complex permittivity decrease but not obviously due to the broken original conductive network. The enforcement of the strain on the complex permeability was attributed to the orientation of flaky CIPs. With the compressing strain applied on the composites with thickness 1 mm or 1.5 mm, the RL value decreased (minimum -13.2 dB and -25.1 dB) and the absorbing band (RL<-10 dB) was widened (5.2-10.6 GHz and 4.0-8.4 GHz). While as the composite thickness decreased caused by the compression strain, the RL value still decreased (minimum -12.4 dB and -18.6 dB) and the absorbing band was also broadened (6.5-10.7 GHz and 4.4-10.0 GHz). Thus the smart absorbing property was effective on preparing absorbers with wide absorption band and high absorption ratio.

Loss, Survival, and Redemption: African American Male Youths' Reflections on Life without Fathers, Manhood, and Coming of Age

ERIC Educational Resources Information Center

Hunter, Andrea G.; Friend, Christian A.; Murphy, S. Yvette; Rollins, Alethea; Williams-Wheeler, Meeshay; Laughinghouse, Janzelean

2006-01-01

Using an interpretivist approach, this article explores young African American men's (n = 20) reflections on coming of age and the meanings of father loss. Based on focus groups, the authors found that it was through autobiographical narratives of loss, survival, and redemption that young men positioned themselves ideologically and constructed the…

Study on the characteristics of magneto-sensitive electromagnetic wave-absorbing properties of magnetorheological elastomers

NASA Astrophysics Data System (ADS)

Yu, Miao; Yang, Pingan; Fu, Jie; Liu, Shuzhi; Qi, Song

2016-08-01

Magnetorheological (MR) materials are a class of materials whose mechanical and electrical properties can be reversible controlled by the magnetic field. In this study, we pioneered research on the effect of a uniform magnetic field with different strengths and directions on the microwave-absorbing properties of magnetorheological elastomers (MREs), in which the ferromagnetic particles are flower-like carbonyl iron powders (CIPs) prepared by an in situ reduction method. The electromagnetic (EM) absorbing properties of the composites have been analyzed by vector network analysis with the coaxial reflection/transmission technique. Under the magnetic field, the columnar or chainlike structures were formed, which allows EM waves to penetrate. Meanwhile, stronger Debye dipolar relaxation and attenuation constant have been obtained when changing the direction of the applied magnetic field. Compared with untreated MREs, not only have the minimum reflection loss (RL) and the effective absorption bandwidth (below -20 dB) greatly increased, the frequencies of the absorbing peaks shift about 15%. This suggests that MREs are a magnetic-field-sensitive electromagnetic wave-absorbing material and have great potential in applications such as in anti-radar camouflage, due to the fact that radar can continuously conduct detection at many electromagnetic frequencies, while the MR materials can adjust the microwave-absorption peak according to the radar frequency.

Comparative Wide Temperature Core Loss Characteristics of Two Candidate Ferrites for the NASA/TRW 1500 W PEBB Converter

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

1999-01-01

High frequency core loss and magnetization properties of commercial type MN8CX and PC40, high resistivity, MnZn based, power ferrites are presented over the temperature range of -l50 C to 150 C, at selected values of peak flux density (B (sub p)). Most of the data is at 100 kHz, with some data extended to 200 and 300 kHz for the MN8CX. Plots of the specific Core loss against temperature exhibit the minimal characteristic of such ferrites. These plots show that the MN8CX is optimized for minimum loss at about 25 C, whereas the PC40 is optimized at about 80 C. At the points of minimum loss and for the same B (sub p), the MN8CX has roughly half the losses of the PC40 at the lower flux densities. This loss ratio continues down to cryogenic temperatures. However, above about 80 C the losses are practically equal. The lowest 100 kHz loss recorded, 50 mW/cm3 for the MNGCX at a B (sub p) of 0.1T, equals that of a very low loss, Co based, transverse magnetically annealed, amorphous ribbon material. Except possibly at lower B (sub p) or much higher frequencies, these ferrites are not competitive for low losses over a wide temperature range with certain specialty amorphous materials. Permeability is computed from a linear model, plots against temperature are presented and again compared to the specialty amorphous materials.

Preferred and Minimum Acceptable Listening Levels for Musicians while Using Floor and In-Ear Monitors

ERIC Educational Resources Information Center

Federman, Jeremy; Ricketts, Todd

2008-01-01

Purpose: This study examined the impact that changing on-stage music and crowd noise levels during musical performance had on preferred listening levels (PLLs) and minimum acceptable listening levels (MALLs) across both floor and in-ear monitors. Method: Participants for this study were 23- to 48-year-old musicians, with and without hearing loss,…

Fe-, Co-, and Ni-Loaded Porous Activated Carbon Balls as Lightweight Microwave Absorbents.

PubMed

Li, Guomin; Wang, Liancheng; Li, Wanxi; Xu, Yao

2015-11-16

Porous activated carbon ball (PACB) composites impregnated with iron, cobalt, nickel and/or their oxides were synthesized through a wet chemistry method involving PACBs as the carrier to load Fe(3+), Co(2+), and Ni(2+) ions and a subsequent carbothermal reduction at different annealing temperatures. The results show that the pyrolysis products of nitrates and/or the products from the carbothermal reduction are embedded in the pores of the PACBs, with different distributions, resulting in different crystalline phases. The as-prepared PACB composites possessed high specific surface areas of 791.2-901.5 m(2)  g(-1) and low densities of 1.1-1.3 g cm(-3). Minimum reflection loss (RL) values of -50.1, -20.6, and -20.4 dB were achieved for Fe-PACB (annealed at 500 °C), Co-PACB (annealed at 800 °C), and Ni-PACB (annealed at 800 °C) composites, respectively. Moreover, the influence of the amount of the magnetic components in the PACB composites on the microwave-absorbing performances was investigated, further confirming that the dielectric loss was the primary contributor to microwave absorption. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental evaluation of shockless supercritical airfoils in cascade

NASA Technical Reports Server (NTRS)

Boldman, D. R.; Buggele, A. E.; Shaw, L. M.

1983-01-01

Surface Mach number distributions, total pressure loss coefficients, and schlieren images of the flow are presented over a range of inlet Mach numbers and air angles. Several different trailing edge geometries were tested. At design conditions a leading edge separation bubble was observed resulting in higher losses than anticipated. The minimum losses were obtained at a negative incidence condition in which the flow was accelerating over most of the supercritical region. Relatively minor differences in losses were measured with the different trailing edge geometries studied.

Continuous variable quantum cryptography: beating the 3 dB loss limit.

PubMed

Silberhorn, Ch; Ralph, T C; Lütkenhaus, N; Leuchs, G

2002-10-14

We demonstrate that secure quantum key distribution systems based on continuous variable implementations can operate beyond the apparent 3 dB loss limit that is implied by the beam splitting attack. The loss limit was established for standard minimum uncertainty states such as coherent states. We show that, by an appropriate postselection mechanism, we can enter a region where Eve's knowledge on Alice's key falls behind the information shared between Alice and Bob, even in the presence of substantial losses.

Low loss fusion splicing polarization-maintaining photonic crystal fiber and conventional polarization-maintaining fiber

NASA Astrophysics Data System (ADS)

Zuoming, Sun; Ningfang, Song; Jing, Jin; Jingming, Song; Pan, Ma

2012-12-01

An efficient and simple method of fusion splicing of a Polarization-Maintaining Photonic Crystal Fiber (PM-PCF) and a conventional Polarization-Maintaining Fiber (PMF) with a low loss of 0.65 dB in experiment is reported. The minimum bending diameter of the joint can reach 2 cm. Theoretical calculation of the splicing loss based on mode field diameters (MFDs) mismatch of the two kinds of fibers is given. All parameters affected the splicing loss were studied.

Auger electron and characteristic energy loss spectra for electro-deposited americium-241

NASA Astrophysics Data System (ADS)

Varma, Matesh N.; Baum, John W.

1983-07-01

Auger electron energy spectra for electro-deposited americium-241 on platinum substrate were obtained using a cylindrical mirror analyzer. Characteristic energy loss spectra for this sample were also obtained at primary electron beam energies of 990 and 390 eV. From these measurements PI, PII, and PIII energy levels for americium-241 are determined. Auger electron energies are compared with theoretically calculated values. Minimum detectability under the present condition of sample preparation and equipment was estimated at approximately 1.2×10-8 g/cm2 or 3.9×10-8 Ci/cm2. Minimum detectability for plutonium-239 under similar conditions was estimated at about 7.2×10-10 Ci/cm2.

Yield loss assessment due to Alternaria blight and its management in linseed.

PubMed

Singh, R B; Singh, H K; Parmar, Arpita

2014-04-01

Field experiments were conducted during 2010-11 and 2011-12 to assess the yield losses due to Alternaria blight disease caused by Alternaria lini and A. linicola in recently released cultivars and their management with the integration of Trichoderma viride, fungicides and plant extract. Disease severity on leaves varied from 41.07% (Parvati) to 65.01% (Chambal) while bud damage per cent ranged between 23.56% (Shekhar) to 46.12% (T-397), respectively in different cultivars. Maximum yield loss of 58.44% was recorded in cultivar Neelum followed by Parvati (55.56%), Meera (55.56%) and Chambal (51.72%), respectively while minimum loss was recorded in Kiran (19.99%) and Jeevan (22.22%). Minimum mean disease severity (19.47%) with maximum disease control (69.74%) was recorded with the treatment: seed treatment (ST) with vitavax power (2 g kg(-1) seed) + 2 foliar sprays (FS) of Saaf (a mixture of carbendazim+mancozeb) 0.2% followed by ST with Trichoderma viride (4g kg(-1) seed) + 2 FS of Saaf (0.2%). Minimum bud damage (13.75%) with maximum control (60.94%) was recorded with treatment of ST with vitavax power+2 FS of propiconazole (0.2%). Maximum mean seed yield (1440 kg ha(-1)) with maximum net return (Rs. 15352/ha) and benefit cost ratio (1:11.04) was obtained with treatment ST with vitavax power + 2 FS of Neem leaf extract followed by treatment ST with vitavax power+2 FS of Saaf (1378 kg ha(-1)).

An eddy-stimulated hotspot for fixed nitrogen-loss from the Peru oxygen minimum zone

NASA Astrophysics Data System (ADS)

Altabet, M. A.; Ryabenko, E.; Stramma, L.; Wallace, D. W. R.; Frank, M.; Grasse, P.; Lavik, G.

2012-07-01

Fixed nitrogen (N) loss to biogenic N2 in intense oceanic O2 minimum zones (OMZ) accounts for a large fraction of the global N sink and is an essential control on the ocean's N budget. However, major uncertainties exist regarding microbial pathways as well as net impact on the magnitude of N-loss and the ocean's overall N budget. Here we report the discovery of a N-loss hotspot in the Peru OMZ associated with a coastally trapped mesoscale eddy that is marked by an extreme N deficit matched by biogenic N2 production, high NO2- levels, and the highest isotope enrichments observed so far in OMZ's for the residual NO3-. High sea surface chlorophyll (SSC) in seaward flowing streamers provides evidence for offshore eddy transport of highly productive, inshore water. Resulting pulses in the downward flux of particles likely stimulated heterotrophic dissimilatory NO3- reduction and subsequent production of biogenic N2. The associated temporal/spatial heterogeneity of N-loss, mediated by a local succession of microbial processes, may explain inconsistencies observed among prior studies. Similar transient enhancements of N-loss likely occur within all other major OMZ's exerting a major influence on global ocean N and N isotope budgets.

Mesoscale Activity and Nitrogen-loss in the Oxygen Minimum Zone of the Eastern Tropical Pacific During ENSO Conditions

NASA Astrophysics Data System (ADS)

Montes, I.; Dewitte, B.; Gutknecht, E.; Paulmier, A.; Dadou, I.; Oschlies, A.; Garçon, V. C.

2015-12-01

The Eastern Tropical South Pacific encompasses one of the most extended Oxygen Minimum zones, which is mainly maintained by a combination of sluggish circulation and high biological productivity in the surface layer leading to elevate organic matter decomposition consuming dissolved oxygen. Low-oxygen areas are important not only for macroorganisms that cannot survive in oxygen-poor conditions, but also because of special biogeochemical processes occurring at low oxygen concentrations. In particular, a large fraction of oceanic nitrogen-loss occurs in these areas via anaerobic microbial processes. These include denitrification and axammox that both lead to a net loss of fixed nitrogen once oxygen concentrations have fallen below some threshold of a few umol/l. Recently it has been found that eddies may act as nitrogen-loss hotspots, possibly by shielding enclosed water parcels from lateral mixing with better ventilated oxygen-richer waters outside the eddies. Here we used a regional coupled biogeochemical model to investigate the relationship between eddies and the nitrogen-loss. We also investigate the mechanisms responsible for the generation of eddies and for possible modulations of eddy activity on interannual timescales, in particular during cold and warm phases of the El Nino Southern Oscillation.

A Formal Approach to the Selection by Minimum Error and Pattern Method for Sensor Data Loss Reduction in Unstable Wireless Sensor Network Communications

PubMed Central

Kim, Changhwa; Shin, DongHyun

2017-01-01

There are wireless networks in which typically communications are unsafe. Most terrestrial wireless sensor networks belong to this category of networks. Another example of an unsafe communication network is an underwater acoustic sensor network (UWASN). In UWASNs in particular, communication failures occur frequently and the failure durations can range from seconds up to a few hours, days, or even weeks. These communication failures can cause data losses significant enough to seriously damage human life or property, depending on their application areas. In this paper, we propose a framework to reduce sensor data loss during communication failures and we present a formal approach to the Selection by Minimum Error and Pattern (SMEP) method that plays the most important role for the reduction in sensor data loss under the proposed framework. The SMEP method is compared with other methods to validate its effectiveness through experiments using real-field sensor data sets. Moreover, based on our experimental results and performance comparisons, the SMEP method has been validated to be better than others in terms of the average sensor data value error rate caused by sensor data loss. PMID:28498312

A Formal Approach to the Selection by Minimum Error and Pattern Method for Sensor Data Loss Reduction in Unstable Wireless Sensor Network Communications.

PubMed

Kim, Changhwa; Shin, DongHyun

2017-05-12

There are wireless networks in which typically communications are unsafe. Most terrestrial wireless sensor networks belong to this category of networks. Another example of an unsafe communication network is an underwater acoustic sensor network (UWASN). In UWASNs in particular, communication failures occur frequently and the failure durations can range from seconds up to a few hours, days, or even weeks. These communication failures can cause data losses significant enough to seriously damage human life or property, depending on their application areas. In this paper, we propose a framework to reduce sensor data loss during communication failures and we present a formal approach to the Selection by Minimum Error and Pattern (SMEP) method that plays the most important role for the reduction in sensor data loss under the proposed framework. The SMEP method is compared with other methods to validate its effectiveness through experiments using real-field sensor data sets. Moreover, based on our experimental results and performance comparisons, the SMEP method has been validated to be better than others in terms of the average sensor data value error rate caused by sensor data loss.

Impact of high power and angle of incidence on prism corrections for visual field loss.

PubMed

Jung, Jae-Hyun; Peli, Eli

2014-01-17

Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice.

Impact of high power and angle of incidence on prism corrections for visual field loss

PubMed Central

Jung, Jae-Hyun; Peli, Eli

2014-01-01

Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice. PMID:24497649

Manifestation, Drivers, and Emergence of Open Ocean Deoxygenation.

PubMed

Levin, Lisa A

2018-01-03

Oxygen loss in the ocean, termed deoxygenation, is a major consequence of climate change and is exacerbated by other aspects of global change. An average global loss of 2% or more has been recorded in the open ocean over the past 50-100 years, but with greater oxygen declines in intermediate waters (100-600 m) of the North Pacific, the East Pacific, tropical waters, and the Southern Ocean. Although ocean warming contributions to oxygen declines through a reduction in oxygen solubility and stratification effects on ventilation are reasonably well understood, it has been a major challenge to identify drivers and modifying factors that explain different regional patterns, especially in the tropical oceans. Changes in respiration, circulation (including upwelling), nutrient inputs, and possibly methane release contribute to oxygen loss, often indirectly through stimulation of biological production and biological consumption. Microbes mediate many feedbacks in oxygen minimum zones that can either exacerbate or ameliorate deoxygenation via interacting nitrogen, sulfur, and carbon cycles. The paleo-record reflects drivers of and feedbacks to deoxygenation that have played out through the Phanerozoic on centennial, millennial, and hundred-million-year timescales. Natural oxygen variability has made it difficult to detect the emergence of a climate-forced signal of oxygen loss, but new modeling efforts now project emergence to occur in many areas in 15-25 years. Continued global deoxygenation is projected for the next 100 or more years under most emissions scenarios, but with regional heterogeneity. Notably, even small changes in oxygenation can have significant biological effects. New efforts to systematically observe oxygen changes throughout the open ocean are needed to help address gaps in understanding of ocean deoxygenation patterns and drivers.

Manifestation, Drivers, and Emergence of Open Ocean Deoxygenation

NASA Astrophysics Data System (ADS)

Levin, Lisa A.

2018-01-01

Oxygen loss in the ocean, termed deoxygenation, is a major consequence of climate change and is exacerbated by other aspects of global change. An average global loss of 2% or more has been recorded in the open ocean over the past 50-100 years, but with greater oxygen declines in intermediate waters (100-600 m) of the North Pacific, the East Pacific, tropical waters, and the Southern Ocean. Although ocean warming contributions to oxygen declines through a reduction in oxygen solubility and stratification effects on ventilation are reasonably well understood, it has been a major challenge to identify drivers and modifying factors that explain different regional patterns, especially in the tropical oceans. Changes in respiration, circulation (including upwelling), nutrient inputs, and possibly methane release contribute to oxygen loss, often indirectly through stimulation of biological production and biological consumption. Microbes mediate many feedbacks in oxygen minimum zones that can either exacerbate or ameliorate deoxygenation via interacting nitrogen, sulfur, and carbon cycles. The paleo-record reflects drivers of and feedbacks to deoxygenation that have played out through the Phanerozoic on centennial, millennial, and hundred-million-year timescales. Natural oxygen variability has made it difficult to detect the emergence of a climate-forced signal of oxygen loss, but new modeling efforts now project emergence to occur in many areas in 15-25 years. Continued global deoxygenation is projected for the next 100 or more years under most emissions scenarios, but with regional heterogeneity. Notably, even small changes in oxygenation can have significant biological effects. New efforts to systematically observe oxygen changes throughout the open ocean are needed to help address gaps in understanding of ocean deoxygenation patterns and drivers.

Electroluminescence analysis for spatial characterization of parasitic optical losses in silicon heterojunction solar cells

NASA Astrophysics Data System (ADS)

Ahmed, Nuha; Zhang, Lei; Sriramagiri, Gowri; Das, Ujjwal; Hegedus, Steven

2018-04-01

Electroluminescence (EL) coupled with reflection measurements are used to spatially quantify optical losses in silicon heterojunction solar cells due to plasmonic absorption in the metal back contacts. The effect of indium tin oxide back reflector in decreasing this plasmonic absorption is found to increase the reflection from the back nickel (Ni)-aluminum (Al) and Al metals by ˜12% and ˜41%, respectively, in both bifacial and front junction silicon solar cells. Losses due to back reflection are calculated by comparison between the EL emission signals in high and low back reflection samples and are shown to be in agreement with standard reflection measurements. We conclude that the optical properties of the back contact can significantly influence the EL intensity which complicates the interpretation of EL as being primarily due to recombination especially when comparing two different devices with spatially varying back surface structures.

Low-loss pigtail reflector for fiber lasers.

PubMed

Masuda, Taizo; Iyoda, Mitsuhiro; Yasumatsu, Yuta; Endo, Masamori

2017-05-01

We demonstrate a low-loss pigtail reflector for a fiber laser comprising off-the-shelf components. A pigtail configuration has the advantage of easy alteration of the reflection properties, which is highly desired for basic studies and metrological applications. Our proposed reflector consists of a dielectric-coated bulk mirror and an Ferrule connector (FC)-type fiber receptacle, which are fixed with a machined holder such that the FC-type connector at the fiber end can be attached onto the mirror surface with an appropriate amount of pressure, which is essential for minimal reflection loss. The measured reflection loss is 0.07 dB, which is one order of magnitude less than that of the typical connection loss, 0.52 dB, of an FC-FC interconnection; it is comparable to the typical splice loss of a single-mode fiber (0.05 dB). The benefit of the proposed method is its versatility that enables its application to various types of fiber lasers.

Mathematical Modeling of Extinction of Inhomogeneous Populations

PubMed Central

Karev, G.P.; Kareva, I.

2016-01-01

Mathematical models of population extinction have a variety of applications in such areas as ecology, paleontology and conservation biology. Here we propose and investigate two types of sub-exponential models of population extinction. Unlike the more traditional exponential models, the life duration of sub-exponential models is finite. In the first model, the population is assumed to be composed clones that are independent from each other. In the second model, we assume that the size of the population as a whole decreases according to the sub-exponential equation. We then investigate the “unobserved heterogeneity”, i.e. the underlying inhomogeneous population model, and calculate the distribution of frequencies of clones for both models. We show that the dynamics of frequencies in the first model is governed by the principle of minimum of Tsallis information loss. In the second model, the notion of “internal population time” is proposed; with respect to the internal time, the dynamics of frequencies is governed by the principle of minimum of Shannon information loss. The results of this analysis show that the principle of minimum of information loss is the underlying law for the evolution of a broad class of models of population extinction. Finally, we propose a possible application of this modeling framework to mechanisms underlying time perception. PMID:27090117

29 CFR 500.105 - DOT standards adopted by the Secretary.

Code of Federal Regulations, 2014 CFR

2014-07-01

... person possesses the following minimum qualifications: (A) No loss of foot, leg, hand or arm, (B) No mental, nervous, organic, or functional disease, likely to interfere with safe driving. (C) No loss of... loading—(A) Distribution and securing of load. No motor vehicle shall be driven nor shall any motor...

Wireless electricity (Power) transmission using solar based power satellite technology

NASA Astrophysics Data System (ADS)

Maqsood, M.; Nauman Nasir, M.

2013-06-01

In the near future due to extensive use of energy, limited supply of resources and the pollution in environment from present resources e.g. (wood, coal, fossil fuel) etc, alternative sources of energy and new ways to generate energy which are efficient, cost effective and produce minimum losses are of great concern. Wireless electricity (Power) transmission (WET) has become a focal point as research point of view and nowadays lies at top 10 future hot burning technologies that are under research these days. In this paper, we present the concept of transmitting power wirelessly to reduce transmission and distribution losses. The wired distribution losses are 70 - 75% efficient. We cannot imagine the world without electric power which is efficient, cost effective and produce minimum losses is of great concern. This paper tells us the benefits of using WET technology specially by using Solar based Power satellites (SBPS) and also focuses that how we make electric system cost effective, optimized and well organized. Moreover, attempts are made to highlight future issues so as to index some emerging solutions.

14 CFR Appendix A to Part 135 - Additional Airworthiness Standards for 10 or More Passenger Airplanes

Code of Federal Regulations, 2010 CFR

2010-01-01

...-takeoff ground run. The ground run calibration must be obtained between 0.8 of the minimum value of V 1... ground run calibration is determined assuming an engine failure at the minimum value of V 1. (c) The... disconnection of the engine compressor from the turbine or from loss of the turbine blades are considered to be...

14 CFR Appendix A to Part 135 - Additional Airworthiness Standards for 10 or More Passenger Airplanes

Code of Federal Regulations, 2012 CFR

2012-01-01

...-takeoff ground run. The ground run calibration must be obtained between 0.8 of the minimum value of V 1... ground run calibration is determined assuming an engine failure at the minimum value of V 1. (c) The... disconnection of the engine compressor from the turbine or from loss of the turbine blades are considered to be...

14 CFR Appendix A to Part 135 - Additional Airworthiness Standards for 10 or More Passenger Airplanes

Code of Federal Regulations, 2013 CFR

2013-01-01

...-takeoff ground run. The ground run calibration must be obtained between 0.8 of the minimum value of V 1... ground run calibration is determined assuming an engine failure at the minimum value of V 1. (c) The... disconnection of the engine compressor from the turbine or from loss of the turbine blades are considered to be...

14 CFR Appendix A to Part 135 - Additional Airworthiness Standards for 10 or More Passenger Airplanes

Code of Federal Regulations, 2014 CFR

2014-01-01

...-takeoff ground run. The ground run calibration must be obtained between 0.8 of the minimum value of V 1... ground run calibration is determined assuming an engine failure at the minimum value of V 1. (c) The... disconnection of the engine compressor from the turbine or from loss of the turbine blades are considered to be...

14 CFR Appendix A to Part 135 - Additional Airworthiness Standards for 10 or More Passenger Airplanes

Code of Federal Regulations, 2011 CFR

2011-01-01

...-takeoff ground run. The ground run calibration must be obtained between 0.8 of the minimum value of V 1... ground run calibration is determined assuming an engine failure at the minimum value of V 1. (c) The... disconnection of the engine compressor from the turbine or from loss of the turbine blades are considered to be...

Optical performance of segmented aperture windows for solar tower receivers

NASA Astrophysics Data System (ADS)

Buck, Reiner

2017-06-01

Segmented quartz windows are a concept to build larger windows for receivers that require a closed aperture. Reflection losses are a significant loss factor for such solar receivers. Without any additional measures, the reflection loss can reach about 12%. One important measure to improve transmission is the application of anti-reflective coatings, which is beneficial in any case. Another option is modifying the window geometry, especially the edge surfaces of the glass segments. A certain fraction of the reflection losses are caused by a light-guide effect in the glass body, for rays entering through the front surface. Changing the cut surfaces in a way reducing the light-guide effect can significantly improve transmission of a segmented window. Several possible configurations are evaluated and discussed. The results of ray-tracing simulations verify the improvement. The final selection of the window configuration depends on the optical properties and on mechanical strength, manufacturing and cost considerations. This has to be evaluated for any specific receiver design.

Proton in SRF Niobium

NASA Astrophysics Data System (ADS)

Wallace, John Paul

2011-03-01

Hydrogen is a difficult impurity to physically deal with in superconducting radio frequency (SRF) niobium, therefore, its properties in the metals should be well understood to allow the metal's superconducting properties to be optimized for minimum loss in the construction of resonant accelerator cavities. It is known that hydrogen is a paramagnetic impurity in niobium from NMR studies. This paramagnetism and its effect on superconducting properties are important to understand. To that end analytical induction measurements aimed at isolating the magnetic properties of hydrogen in SRF niobium are introduced along with optical reflection spectroscopy which is also sensitive to the presence of hydrogen. From the variety, magnitude and rapid kinetics found in the optical and magnetic properties of niobium contaminated with hydrogen forced a search for an atomic model. This yielded quantum mechanical description that correctly generates the activation energy for diffusion of the proton and its isotopes not only in niobium but the remaining metals for which data is available. This interpretation provides a frame work for understanding the individual and collective behavior of protons in metals.

Synthesis, characterization and microwave characteristics of ATP/BaFe12O19/PANI ternary composites

NASA Astrophysics Data System (ADS)

Bai, Dezhong; Feng, Huixia; Chen, Nali; Tan, Lin; Qiu, Jianhui

2018-07-01

In this paper, we introduced attapulgite (ATP) into the system of ferrite composites for the first time. By sol-gel self-propagating combustion method, attapulgite/barium ferrite (ATP/BaFe12O19) was prepared, and then ternary composites of attapulgite/barium ferrite/polyaniline (ATP/BaFe12O19/PANI) were obtained by in-situ oxidative polymerization of aniline on ATP/BaFe12O19 mixture. The phase composition, morphology and electromagnetic properties of the as-prepared composites were characterized by X-ray diffraction (XRD), Transmission election microscope (TEM), Fourier transform infrared (FTIR), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). We found that the ATP/BaFe12O19/PANI composites at a thickness of 2 mm have the minimum reflection loss of -11.89 dB at 11.28 GHz, besides the effective absorption bandwidth (less than -5 dB) reached 6.39 GHz (from 8.42 GHz to 14.81 GHz).

Microwave absorbing property of silicone rubber composites with added carbonyl iron particles and graphite platelet

NASA Astrophysics Data System (ADS)

Xu, Yonggang; Zhang, Deyuan; Cai, Jun; Yuan, Liming; Zhang, Wenqiang

2013-02-01

Silicone rubber composites filled with carbonyl iron particles (CIPs) and graphite platelet (GP) were prepared using non-coating or coating processes. The complex permittivity and permeability of the composites were measured using a vector network analyzer in the frequency range of 1-18 GHz and dc electric conductivity was measured by the standard four-point contact method. The results showed that CIPs/GP composites fabricated in the coating process had the highest permittivity and permeability due to the particle orientation and interactions between the two absorbents. The coating process resulted in a decreased effective eccentricity of the absorbents, and the dc conductivity increased according to Neelakanta's equations. The reflection loss (RL) value showed that the composites had an excellent absorbing property in the L-band, minimum -11.85 dB at 1.5 mm and -15.02 dB at 2 mm. Thus, GP could be an effective additive in preparing thin absorbing composites in the L-band.

Design of lightweight broadband microwave absorbers in the X-band based on (polyaniline/MnNiZn ferrite) nanocomposites

NASA Astrophysics Data System (ADS)

Ali, Nassim Nasser; Al-Qassar Bani Al-Marjeh, Rama; Atassi, Yomen; Salloum, Akil; Malki, Adnan; Jafarian, Mojtaba

2018-05-01

We present the design of novel, lightweight, broadband microwave absorbers based on polyaniline/Mn0.1Ni0.45Zn0.45Fe2O4 (PANI/MnNiZn ferrite) nanocomposites. The ferrite is synthesized by sol-gel technique. Then, the polymer is deposited by in-situ chemical oxidative polymerization. The structural and morphological characterizations of the composites are investigated by SEM, XRD, FT-IR and UV-vis spectroscopy. The functional characterization is performed by measuring the dc-conductivity and microwave absorption characteristics in the X-band. The absorbers exhibit broad bandwidths under -10 dB ranging from 2.60 to 3.74 GHz and low surface density ranging from 2.5 to 3.1 kg/m2. The absorber of 3.74 GHz bandwidth has a minimum reflection loss of -31.32 dB at 11.13 GHz with a matching thickness of 3 mm and a low loading in paraffin of only 25% w/w.

Soiling of building envelope surfaces and its effect on solar reflectance. Part I: Analysis of roofing product databases

DOE PAGES

Sleiman, Mohamad; Ban-Weiss, George; Gilbert, Haley E.; ...

2011-12-01

The use of highly reflective “cool” roofing materials can decrease demand for air conditioning, mitigate the urban heat island effect, and potentially slow global warming. However, initially high roof solar reflectance can be degraded by natural soiling and weathering processes. We evaluated solar reflectance losses after three years of natural exposure reported in two separate databases: the Rated Products Directory of the US Cool Roof Rating Council (CRRC) and information reported by manufacturers to the US Environmental Protection Agency (EPA)’s ENERGY STAR® rating program. Many product ratings were culled because they were duplicative (within a database) or not measured. Amore » second, site-resolved version of the CRRC dataset was created by transcribing from paper records the site-specific measurements of aged solar reflectance in Florida, Arizona and Ohio. Products with high initial solar reflectance tended to lose reflectance, while those with very low initial solar reflectance tended to become more reflective as they aged. Within the site-resolved CRRC database, absolute solar reflectance losses for samples of medium-to-high initial solar reflectance were 2 - 3 times greater in Florida (hot and humid) than in Arizona (hot and dry); losses in Ohio (temperate but polluted) were intermediate. Disaggregating results by product type, factory-applied coating, field-applied coating, metal, modified bitumen, shingle, singleply membrane and tile, revealed that absolute solar reflectance losses were largest for fieldapplied coating, modified bitumen and single-ply membrane products, and smallest for factoryapplied coating and metal products.The 2008 Title 24 provisional aged solar reflectance formula overpredicts the measured aged solar reflectance of 0% to 30% of each product type in the culled public CRRC database. The rate of overprediction was greatest for field-applied coating and single-ply membrane products and least for factory-applied coating, shingle, and metal products. New product-specific formulas can be used to estimate provisional aged solar reflectance from initial solar reflectance pending measurement of aged solar reflectance. The appropriate value of soiling resistance varies by product type and is selected to attain some desired overprediction rate for the formula. The correlations for shingle products presented in this paper should not be used to predict aged solar reflectance or estimate provisional aged solar reflectance because the data set is too small and too limited in range of initial solar reflectance.« less

Rejection or selection: influence of framing in investment decisions.

PubMed

Cheng, Pi-Yueh; Chiou, Wen-Bin

2010-02-01

According to prospect theory, reflection effects result in preferences for risk-averse choices in gain situations and risk-seeking choices in loss situations. However, relevant literature in regard to decision making has suggested that positive information receives more weight in a selection task, whereas negative information receives more weight in a rejection task. The present study examined whether the nature of a decision task (selection vs rejection) would moderate the reflection effects. Undergraduates (47 men, 49 women; M age = 20.5 yr., SD = 1.1), selected according to specific screening criteria, participated in an experimental study. Typical reflection effects were observed in both selection and rejection task conditions. More importantly, negative information (i.e., the information about probable loss in risky choice of gain situations and the information about certain loss in cautious choice of loss situations) provided in the context of a rejection task received more weight and resulted in more frequent endorsements of the cautious choice in gain situations and of the risky choice in loss situations. Hence, the findings suggest that a decision context characterized by rejection may expand the reflection effects and thereby provide important information about situations in which investment decisions occur in a context characterized by rejection.

Nd:YAG-laser-based time-domain reflectometry measurements of the intrinsic reflection signature from PMMA fiber splices

NASA Astrophysics Data System (ADS)

Lawson, Christopher M.; Michael, Robert R., Jr.; Dressel, Earl M.; Harmony, David W.

1991-12-01

Optical time domain reflectometry (OTDR) measurements have been performed on polished polymethylmethacrylate (PMMA) plastic fiber splices. After the dominant splice reflection sources due to surface roughness, inexact index matching, and fiber core misalignment were eliminated, an intrinsic OTDR signature 3 - 8 dB above the Rayleigh backscatter floor remained with all tested fibers. This minimum splice reflectivity exhibits characteristics that are consistent with sub-surface polymer damage and can be used for detection of PMMA fiber splices.

Performance of transonic fan stage with weight flow per unit annulus area of 178 kilograms per second per square meter (6.5(lb/sec)/(sq ft))

NASA Technical Reports Server (NTRS)

Moore, R. D.; Urasek, D. C.; Kovich, G.

1973-01-01

The overall and blade-element performances are presented over the stable flow operating range from 50 to 100 percent of design speed. Stage peak efficiency of 0.834 was obtained at a weight flow of 26.4 kg/sec (58.3 lb/sec) and a pressure ratio of 1.581. The stall margin for the stage was 7.5 percent based on weight flow and pressure ratio at stall and peak efficiency conditions. The rotor minimum losses were approximately equal to design except in the blade vibration damper region. Stator minimum losses were less than design except in the tip and damper regions.

Polarimetric imaging of retinal disease by polarization sensitive SLO

NASA Astrophysics Data System (ADS)

Miura, Masahiro; Elsner, Ann E.; Iwasaki, Takuya; Goto, Hiroshi

2015-03-01

Polarimetry imaging is used to evaluate different features of the macular disease. Polarimetry images were recorded using a commercially- available polarization-sensitive scanning laser opthalmoscope at 780 nm (PS-SLO, GDx-N). From data sets of PS-SLO, we computed average reflectance image, depolarized light images, and ratio-depolarized light images. The average reflectance image is the grand mean of all input polarization states. The depolarized light image is the minimum of crossed channel. The ratio-depolarized light image is a ratio between the average reflectance image and depolarized light image, and was used to compensate for variation of brightness. Each polarimetry image is compared with the autofluorescence image at 800 nm (NIR-AF) and autofluorescence image at 500 nm (SW-AF). We evaluated four eyes with geographic atrophy in age related macular degeneration, one eye with retinal pigment epithelium hyperplasia, and two eyes with chronic central serous chorioretinopathy. Polarization analysis could selectively emphasize different features of the retina. Findings in ratio depolarized light image had similarities and differences with NIR-AF images. Area of hyper-AF in NIR-AF images showed high intensity areas in the ratio depolarized light image, representing melanin accumulation. Areas of hypo-AF in NIR-AF images showed low intensity areas in the ratio depolarized light images, representing melanin loss. Drusen were high-intensity areas in the ratio depolarized light image, but NIR-AF images was insensitive to the presence of drusen. Unlike NIR-AF images, SW-AF images showed completely different features from the ratio depolarized images. Polarization sensitive imaging is an effective tool as a non-invasive assessment of macular disease.

12 CFR 208.23 - Agricultural loan loss amortization.

Code of Federal Regulations, 2010 CFR

2010-01-01

... principal shareholders, a participating bank may amortize in its Reports of Condition and Income: (i) Any loss on a qualified agricultural loan that the bank would be required to reflect in its financial... required to reflect in its financial statements for any period between and including 1983 and 1991...

Design Information for Emergency Operations Centers.

DTIC Science & Technology

1983-06-01

STC 40-45 4. Visual privacy. Sound Reflectances: 5. Electrical survey. Ceiling: NRC 50 6. Adequate lighting. Floor: NRC 25 7. Adequate thermal comfort . 4...ceiling to 7. Adequate thermal comfort . reduce noise. 8. Image appropriate for authority 4. 60-in.-high minimum wall panels. given. 5. 110-V outlets as...tions. 5. Electrical supply. 2. 9-ft minimum for open plan office 6. Adequate lighting, schemes. 7. Adequate thermal comfort . 3. Enclosing walls: STC 40

26 CFR 1.585-2 - Addition to reserve.

Code of Federal Regulations, 2010 CFR

2010-04-01

... reserve for losses on loans as defined in paragraph (e)(2) of this section is the amount allowable under... shall make a minimum addition to the reserve for losses on loans as defined in paragraph (e)(2) of this... the case of any taxable year preceded by less than 5 authorization years (as defined in paragraph (e...

Loss Aversion Reflects Information Accumulation, Not Bias: A Drift-Diffusion Model Study.

PubMed

Clay, Summer N; Clithero, John A; Harris, Alison M; Reed, Catherine L

2017-01-01

Defined as increased sensitivity to losses, loss aversion is often conceptualized as a cognitive bias. However, findings that loss aversion has an attentional or emotional regulation component suggest that it may instead reflect differences in information processing. To distinguish these alternatives, we applied the drift-diffusion model (DDM) to choice and response time (RT) data in a card gambling task with unknown risk distributions. Loss aversion was measured separately for each participant. Dividing the participants into terciles based on loss aversion estimates, we found that the most loss-averse group showed a significantly lower drift rate than the other two groups, indicating overall slower uptake of information. In contrast, neither the starting bias nor the threshold separation (barrier) varied by group, suggesting that decision thresholds are not affected by loss aversion. These results shed new light on the cognitive mechanisms underlying loss aversion, consistent with an account based on information accumulation.

Loss Aversion Reflects Information Accumulation, Not Bias: A Drift-Diffusion Model Study

PubMed Central

Clay, Summer N.; Clithero, John A.; Harris, Alison M.; Reed, Catherine L.

2017-01-01

Defined as increased sensitivity to losses, loss aversion is often conceptualized as a cognitive bias. However, findings that loss aversion has an attentional or emotional regulation component suggest that it may instead reflect differences in information processing. To distinguish these alternatives, we applied the drift-diffusion model (DDM) to choice and response time (RT) data in a card gambling task with unknown risk distributions. Loss aversion was measured separately for each participant. Dividing the participants into terciles based on loss aversion estimates, we found that the most loss-averse group showed a significantly lower drift rate than the other two groups, indicating overall slower uptake of information. In contrast, neither the starting bias nor the threshold separation (barrier) varied by group, suggesting that decision thresholds are not affected by loss aversion. These results shed new light on the cognitive mechanisms underlying loss aversion, consistent with an account based on information accumulation. PMID:29066987

78 FR 52460 - Single Family Housing Direct Loan Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-23

... an informal arrangement, which is free from Agency oversight or minimum competency standards. This... to confirm that their individual competency level reflects the organization's years of experience...

Clinical Trials: D-Methionine to Reduce Noise-Induced Hearing Loss. Phase 3

DTIC Science & Technology

2014-03-01

placebo-controlled Phase 3 clinical trial of oral D-met to reduce noise-induced hearing loss (NIHL) and tinnitus . The goal of the study is to...primary objective of this study is to determine the efficacy of D-Met in preventing NIHL or reducing tinnitus secondary to a minimum of 500 rounds...an oral, orange flavored suspension of D-methionine can prevent noise-induced hearing loss (NIHL) and tinnitus in our troops. Hypotheses

An eddy-stimulated hotspot for fixed nitrogen-loss from the Peru oxygen minimum zone

NASA Astrophysics Data System (ADS)

Altabet, M. A.; Ryabenko, E.; Stramma, L.; Wallace, D. W. R.; Frank, M.; Grasse, P.; Lavik, G.

2012-12-01

Fixed nitrogen (N) loss to biogenic N2 in intense oceanic O2 minimum zones (OMZ) accounts for a large fraction of the global N sink and is an essential control on the ocean's N-budget. However, major uncertainties exist regarding microbial pathways as well as net impact on the magnitude of N-loss and the ocean's overall N-budget. Here we report the discovery of a N-loss hotspot in the Peru OMZ associated with a coastally trapped mesoscale eddy that is marked by an extreme N-deficit matched by biogenic N2 production, high NO2- levels, and the highest isotope enrichments observed so far in OMZ's for the residual NO3-. High sea surface chlorophyll in seaward flowing streamers provides evidence for offshore eddy transport of highly productive, inshore water. Resulting pulses in the downward flux of particles likely stimulated heterotrophic dissimilatory NO3- reduction and subsequent production of biogenic N2 within the OMZ. A shallower biogenic N2 maximum within the oxycline is likely a feature advected by the eddy streamer from the shelf. Eddy-associated temporal-spatial heterogeneity of N-loss, mediated by a local succession of microbial processes, may explain inconsistencies observed among prior studies. Similar transient enhancements of N-loss likely occur within all other major OMZ's exerting a major influence on global ocean N and N isotope budgets.

Three-Dimensional Photography for Quantitative Assessment of Penile Volume-Loss Deformities in Peyronie's Disease.

PubMed

Margolin, Ezra J; Mlynarczyk, Carrie M; Mulhall, John P; Stember, Doron S; Stahl, Peter J

2017-06-01

Non-curvature penile deformities are prevalent and bothersome manifestations of Peyronie's disease (PD), but the quantitative metrics that are currently used to describe these deformities are inadequate and non-standardized, presenting a barrier to clinical research and patient care. To introduce erect penile volume (EPV) and percentage of erect penile volume loss (percent EPVL) as novel metrics that provide detailed quantitative information about non-curvature penile deformities and to study the feasibility and reliability of three-dimensional (3D) photography for measurement of quantitative penile parameters. We constructed seven penis models simulating deformities found in PD. The 3D photographs of each model were captured in triplicate by four observers using a 3D camera. Computer software was used to generate automated measurements of EPV, percent EPVL, penile length, minimum circumference, maximum circumference, and angle of curvature. The automated measurements were statistically compared with measurements obtained using water-displacement experiments, a tape measure, and a goniometer. Accuracy of 3D photography for average measurements of all parameters compared with manual measurements; inter-test, intra-observer, and inter-observer reliabilities of EPV and percent EPVL measurements as assessed by the intraclass correlation coefficient. The 3D images were captured in a median of 52 seconds (interquartile range = 45-61). On average, 3D photography was accurate to within 0.3% for measurement of penile length. It overestimated maximum and minimum circumferences by averages of 4.2% and 1.6%, respectively; overestimated EPV by an average of 7.1%; and underestimated percent EPVL by an average of 1.9%. All inter-test, inter-observer, and intra-observer intraclass correlation coefficients for EPV and percent EPVL measurements were greater than 0.75, reflective of excellent methodologic reliability. By providing highly descriptive and reliable measurements of penile parameters, 3D photography can empower researchers to better study volume-loss deformities in PD and enable clinicians to offer improved clinical assessment, communication, and documentation. This is the first study to apply 3D photography to the assessment of PD and to accurately measure the novel parameters of EPV and percent EPVL. This proof-of-concept study is limited by the lack of data in human subjects, which could present additional challenges in obtaining reliable measurements. EPV and percent EPVL are novel metrics that can be quickly, accurately, and reliably measured using computational analysis of 3D photographs and can be useful in describing non-curvature volume-loss deformities resulting from PD. Margolin EJ, Mlynarczyk CM, Muhall JP, et al. Three-Dimensional Photography for Quantitative Assessment of Penile Volume-Loss Deformities in Peyronie's Disease. J Sex Med 2017;14:829-833. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Research: The Effect of Wetland Mitigation Banking on the Achievement of No-Net-Loss.

PubMed

BROWN; LANT

1999-04-01

/ This study determines whether the 68 wetland mitigation banks in existence in the United States through 1 January 1996 are achieving no-net-loss of wetland acreage nationally and regionally. Although 74% of the individual banks achieve no-net-loss by acreage, overall, wetland mitigation banks are projected to result in a net loss of 21,328 acres of wetlands nationally, 52% of the acreage in banks, as already credited wetland acreages are converted to otheruses. While most wetland mitigation banks are using appropriate compensation methods and ratios, several of the largest banks use preservation or enhancement, instead of restoration or creation. Most of these preservation/enhancement banks use minimum mitigation ratios of 1:1, which is much lower than ratios given in current guidelines. Assuming that mitigation occurs in these banks as preservation at the minimum allowable ratio, ten of these banks, concentrated in the western Gulf Coast region, will account for over 99% of projected net wetland acreage loss associated with banks. We conclude that wetland mitigation banking is a conceptually sound environmental policy and planning tool, but only if applied according to recently issued guidelines that ensure no-net-loss of wetland functions and values. Wetland mitigation banking inevitably leads to geographic relocation of wetlands, and therefore changes, either positively or negatively, the functions they perform and ecosystem services they provide. KEY WORDS: Mitigation banking; Wetlands; Army Corps of Engineers; No-net-loss

Real-time individualization of the unified model of performance.

PubMed

Liu, Jianbo; Ramakrishnan, Sridhar; Laxminarayan, Srinivas; Balkin, Thomas J; Reifman, Jaques

2017-12-01

Existing mathematical models for predicting neurobehavioural performance are not suited for mobile computing platforms because they cannot adapt model parameters automatically in real time to reflect individual differences in the effects of sleep loss. We used an extended Kalman filter to develop a computationally efficient algorithm that continually adapts the parameters of the recently developed Unified Model of Performance (UMP) to an individual. The algorithm accomplishes this in real time as new performance data for the individual become available. We assessed the algorithm's performance by simulating real-time model individualization for 18 subjects subjected to 64 h of total sleep deprivation (TSD) and 7 days of chronic sleep restriction (CSR) with 3 h of time in bed per night, using psychomotor vigilance task (PVT) data collected every 2 h during wakefulness. This UMP individualization process produced parameter estimates that progressively approached the solution produced by a post-hoc fitting of model parameters using all data. The minimum number of PVT measurements needed to individualize the model parameters depended upon the type of sleep-loss challenge, with ~30 required for TSD and ~70 for CSR. However, model individualization depended upon the overall duration of data collection, yielding increasingly accurate model parameters with greater number of days. Interestingly, reducing the PVT sampling frequency by a factor of two did not notably hamper model individualization. The proposed algorithm facilitates real-time learning of an individual's trait-like responses to sleep loss and enables the development of individualized performance prediction models for use in a mobile computing platform. © 2017 European Sleep Research Society.

Miniature fiber optic loop subcomponent for compact sensors and dense routing

NASA Astrophysics Data System (ADS)

Gillham, Frederick J.; Stowe, David W.; Ouellette, Thomas R.; Pryshlak, Adrian P.

1999-05-01

Fiber optic data links and embedded sensors, such as Fabry- Perot and Mach-Zehnders, are important elements in smart structure architectures. Unfortunately, one problem with optical fiber is the inherent limit through which fibers and cables can be looped. A revolutionary, patented technology has been developed which overcomes this problem. Based on processing the fiber into low loss miniature bends, it permits routing the fiber to difficult areas, and minimizing the size of sensors and components. The minimum bend diameter for singlemode fiber is typically over two inches in diameter, to avoid light attenuation and limit stresses which could prematurely break the fiber. With the new miniature bend technology, bend diameters as small as 1 mm are readily achieved. One embodiment is a sub-component with standard singlemode fiber formed into a 180 degree bend and packaged in a glass tube only 1.5 mm OD X 8 mm long, Figure 1. Measured insertion loss is less than 0.2 dB from 1260 nm to 1680 nm. A final processing step which anneals the fiber into the eventual curvature, reduces the internal stress, thereby resulting in long life expectancy with robust immunity to external loading. This paper addresses the optical and physical performance of the sub-component. Particular attention is paid to attenuation spectra, polarization dependent loss, reflectance, thermal cycle, damp heat, and shock tests. Applications are presented which employs the bend technology. Concatenating right angle bends into a 'wire harness' demonstrates the ability to route fiber through a smart engine or satellite structure. Miniature optical coils are proposed for sensors and expansion joints.

Comparison of radiographic joint space width and magnetic resonance imaging for prediction of knee replacement: A longitudinal case-control study from the Osteoarthritis Initiative.

PubMed

Eckstein, Felix; Boudreau, Robert; Wang, Zhijie; Hannon, Michael J; Duryea, Jeff; Wirth, Wolfgang; Cotofana, Sebastian; Guermazi, Ali; Roemer, Frank; Nevitt, Michael; John, Markus R; Ladel, Christoph; Sharma, Leena; Hunter, David J; Kwoh, C Kent

2016-06-01

To evaluate whether change in fixed-location measures of radiographic joint space width (JSW) and cartilage thickness by MRI predict knee replacement. Knees replaced between 36 and 60 months' follow-up in the Osteoarthritis Initiative were each matched with one control by age, sex and radiographic status. Radiographic JSW was determined from fixed flexion radiographs and subregional femorotibial cartilage thickness from 3 T MRI. Changes between the annual visit before replacement (T0) and 2 years before T0 (T-2) were compared using conditional logistic regression. One hundred and nineteen knees from 102 participants (55.5 % women; age 64.2 ± 8.7 [mean ± SD] years) were studied. Fixed-location JSW change at 22.5 % from medial to lateral differed more between replaced and control knees (case-control [cc] OR = 1.57; 95 % CI: 1.23-2.01) than minimum medial JSW change (ccOR = 1.38; 95 % CI: 1.11-1.71). Medial femorotibial cartilage loss displayed discrimination similar to minimum JSW, and central tibial cartilage loss similar to fixed-location JSW. Location-independent thinning and thickening scores were elevated prior to knee replacement. Discrimination of structural progression between knee pre-placement cases versus controls was stronger for fixed-location than minimum radiographic JSW. MRI displayed similar discrimination to radiography and suggested greater simultaneous cartilage thickening and loss prior to knee replacement. • Fixed-location JSW predicts surgical knee replacement more strongly than minimum JSW. • MRI predicts knee replacement with similar accuracy to radiographic JSW. • MRI reveals greater cartilage thinning and thickening prior to knee replacement.

Structural and functional polymer-matrix composites for electromagnetic applications

NASA Astrophysics Data System (ADS)

Wu, Junhua

This dissertation addresses the science and technology of functional and structural polymer-matrix composite materials for electromagnetic applications, which include electromagnetic interference (EMI) shielding and low observability (Stealth). The structural composites are continuous carbon fiber epoxy-matrix composites, which are widely used for airframes. The functional composites are composites with discontinuous fillers and in both bulk and coating forms. Through composite structure variation, attractive electromagnetic properties have been achieved. With no degradation of the tensile strength or modulus, the shielding effectiveness of the structural composites has been improved by enhancing multiple reflections through light activation of the carbon fiber. The multiple reflections loss of the electromagnetic wave increases from 1.1 to 10.2 dB at 1.0 GHz due to the activation. Such a large effect of multiple reflections has not been previously reported in any material. The observability of these composites has been lowered by decreasing the electrical conductivity (and hence decreasing the reflection loss) through carbon fiber coating. The incorporation of mumetal, a magnetic alloy particulate filler (28-40 mum size), in a latex paint has been found to be effective for enhancing the shielding only if the electrical resistivity of the resulting composite coating is below 10 O.cm, as rendered by a conductive particulate filler, such as nickel flake (14-20 mum size). This effectiveness (39 dB at 1.0 GHz) is attributed to the absorption of the electromagnetic wave by the mumetal and the nickel flake, with the high conductivity rendered by the presence of the nickel flake resulting in a relatively high reflection loss of 15.5 dB. Without the nickel flake, the mumetal gives only 3 dB of shielding and 1.5 dB of reflection loss at 1.0 GHz. Nickel powder (0.3-0.5 mum size) has been found to be an effective filler for improving the shielding of polyethersulfone (PES) bulk composites. At 13 vol.%, it gives 90 dB of shielding at 1.0 GHz, compared to 46 dB for nickel powder (20-40 mum) and the prior value of 87 dB reported by Shui and Chung for nickel filament (0.4 mum diameter). The minimum filler content for high shielding is 7-13 vol.% for both nickel powders, compared to 3-7 vol.% for nickel filament. Due to the skin effect, a small filler unit size helps the shielding, which is dominated by reflection. Carbon filament (0.1 mum, >100 mum long, >1000 in aspect ratio) is effective for enhancing the shielding effectiveness of a coating made from a water-based colloid that contains graphite particle (0.7-0.8 mum, 22 wt.%) and a starch-type binder. The filament addition increases the shielding from 11 to 20 dB at 1.0 GHz. This increase in shielding is associated with increase in reflectivity and decrease in electrical resistivity. Graphite flake (5 mum) at the same volume proportion is even more effective; its addition increases the shielding from 11 to 28 dB. The combined use of the graphite flake and a low proportion of stainless steel fiber (11 mum diameter, 2 mm long, 180 in aspect ratio) is yet more effective; it increases the shielding from 11 to 34 dB. Alumina particle (5 mum size, 15 vol.%) is effective for increasing the impedance of a coating made from the graphite colloid by 290%, though the shielding effectiveness is reduced from 18 to 11 dB at 1.0 GHz. The high impedance is attractive for MRIcompatible pacemaker leads. The interface between filler and matrix also affects the shielding. Silane treatment of the surface of graphite flake (5 mum) used in the graphite colloid decreases the viscosity (e.g., from 1750 to 1460 CP), but it also decreases the shielding effectiveness (e.g., from 20 to 16 dB at 1 GHz). Ozone treatment gives a similar effect. The decrease of the shielding effectiveness is attributed to the increase in resistivity due to the surface treatment. Measured and calculated values of the reflection loss are comparable, with the measured value lower than the corresponding calculated value, when the resistivity is sufficiently low (e.g., resistivity below 10 O.cm in case of PES-matrix composites) and a strongly magnetic filler such as mumetal is absent. The agreement is better when the skin depth approaches the specimen thickness. The agreement is worse for the latex paint-based composites than the PES-matrix composites, probably due to superior electrical connectivity in the latter.

Optical losses of solar mirrors due to atmospheric contamination at Liberal, Kansas and Oologah, Oklahoma

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

Dake, L.S.; Lind, M.A.

An assessment is presented of the effect of outdoor exposure on mirrors located at two sites selected for potential solar cogeneration/repowering facilities: Liberal, Kansas and Oologah, Oklahoma. Mirror coupons were placed on tracking heliostat simulators located in the proposed heliostat fields and were removed periodically. The spectral hemispherical and diffuse reflectances of these coupons were measured. Representative samples were analyzed for the chemical composition of the dust particulates using SEM/EDX. Other samples were washed with a high pressure spray and recharacterized to determine the effects of the residual dust. Average specular reflectance losses over the entire test period (up tomore » 504 days) were 6 to 12%, with a range of 1 to 30%. Specular reflectance losses varied widely from day to day depending on local weather conditions. The losses due to scattering were 2 to 5 times greater than the losses due to absorptance. The average degradation rate over the first thirty days was an order of magnitude larger than the average degradation rate over the entire sampling period. Specular reflectance loss rates averaged 0.5% per day and greater between periods of natural cleaning. The chemical composition of the dust on the mirrors was characteristic of the indigenous soil, with some samples also showing the presence of sulfur and chlorine, possibly from cooling tower drift.« less

Low loss jammed-array wideband sawtooth filter based on a finite reflection virtually imaged array

NASA Astrophysics Data System (ADS)

Tan, Zhongwei; Cao, Dandan; Ding, Zhichao

2018-03-01

An edge filter is a potential technology in the fiber Bragg grating interrogation that has the advantages of fast response speed and suitability for dynamic measurement. To build a low loss, wideband jammed-array wideband sawtooth (JAWS) filter, a finite reflection virtually imaged array (FRVIA) is proposed and demonstrated. FRVIA is different from the virtually imaged phased array in that it has a low reflective front end. This change will lead to many differences in the device's performance in output optical intensity distribution, spectral resolution, output aperture, and tolerance of the manufacture errors. A low loss, wideband JAWS filter based on an FRVIA can provide an edge filter for each channel, respectively.

Significant reduction of saturation magnetization and microwave-reflection loss in barium-natural ferrite via Nd3+ substitution

NASA Astrophysics Data System (ADS)

Widanarto, W.; Ardenti, E.; Ghoshal, S. K.; Kurniawan, C.; Effendi, M.; Cahyanto, W. T.

2018-06-01

To minimize the signal degradation, many electronic devices require efficient microwave absorbers with very low reflection-losses within the X-band. We prepared a series of trivalent neodymium-ion (Nd3+) substituted barium-natural ferrite using a modified solid-state reaction method. The effect of the Nd3+-ion content on the structure, surface morphology, magnetic properties, and microwave reflection loss was studied. The composites were characterized using X-ray diffraction, a vibrating sample magnetometer, scanning electron microscopy, and a vector network analyzer. The XRD patterns of the sample without Nd3+ reveal the presence of BaFe12O19 (hexagonal) and BaFe2O4 (rhombohedral) phases. Furthermore, a new hexagonal crystal phase of Ba6Nd2Fe4O15 appeared after substituting Nd3+. The average size of the prepared barium-natural ferrite particles was estimated to be between 0.4 and 0.8 μm. Both saturation magnetization and microwave reflection losses of these barium-ferrites were significantly reduced by increasing the Nd3+ content.

Assessment of Refueling Hose Visibility: Post-Cleaning Evaluation

DTIC Science & Technology

2013-10-01

Cott, H.P., and Kinkade, R.G. (Eds.), Human Engineering Guide to Equipment Design. Washington, DC: GPO. F-35 Gen 5 HMDS spec for minimum...spectral band sensors: visible, near IR, and short-wave IR. These images will be captured for each of the samples set up for both the geometries...Contrast Ratio Near IR Black Reflectance White Reflectance Contrast Ratio Short Wave IR Black

A simple method to measure critical angles for high-sensitivity differential refractometry.

PubMed

Zilio, S C

2012-01-16

A total internal reflection-based differencial refractometer, capable of measuring the real and imaginary parts of the complex refractive index in real time, is presented. The device takes advantage of the phase difference acquired by s- and p-polarized light to generate an easily detectable minimum at the reflected profile. The method allows to sensitively measuring transparent and turbid liquid samples.

Cyber warfare and electronic warfare integration in the operational environment of the future: cyber electronic warfare

NASA Astrophysics Data System (ADS)

Askin, Osman; Irmak, Riza; Avsever, Mustafa

2015-05-01

For the states with advanced technology, effective use of electronic warfare and cyber warfare will be the main determining factor of winning a war in the future's operational environment. The developed states will be able to finalize the struggles they have entered with a minimum of human casualties and minimum cost thanks to high-tech. Considering the increasing number of world economic problems, the development of human rights and humanitarian law it is easy to understand the importance of minimum cost and minimum loss of human. In this paper, cyber warfare and electronic warfare concepts are examined in conjunction with the historical development and the relationship between them is explained. Finally, assessments were carried out about the use of cyber electronic warfare in the coming years.

Minimum Abutment Height to Eliminate Bone Loss: Influence of Implant Neck Design and Platform Switching.

PubMed

Spinato, Sergio; Galindo-Moreno, Pablo; Bernardello, Fabio; Zaffe, Davide

This retrospective study quantitatively analyzed the minimum prosthetic abutment height to eliminate bone loss after 4.7-mm-diameter implant placement in maxillary bone and how grafting techniques can affect the marginal bone loss in implants placed in maxillary areas. Two different implant types with a similar neck design were singularly placed in two groups of patients: the test group, with platform-switched implants, and the control group, with conventional (non-platform-switched) implants. Patients requiring bone augmentation underwent unilateral sinus augmentation using a transcrestal technique with mineralized xenograft. Radiographs were taken immediately after implant placement, after delivery of the prosthetic restoration, and after 12 months of loading. The average mesial and distal marginal bone loss of the control group (25 patients) was significantly more than twice that of the test group (26 patients), while their average abutment height was similar. Linear regression analysis highlighted a statistically significant inverse relationship between marginal bone loss and abutment height in both groups; however, the intercept of the regression line, both mesially and distally, was 50% lower for the test group than for the control group. The marginal bone loss was annulled with an abutment height of 2.5 mm for the test group and 3.0 mm for the control group. No statistically significant differences were found regarding marginal bone loss of implants placed in native maxillary bone compared with those placed in the grafted areas. The results suggest that the shorter the abutment height, the greater the marginal bone loss in cement-retained prostheses. Abutment height showed a greater influence in platform-switched than in non-platform-switched implants on the limitation of marginal bone loss.

Enhanced Acoustic Black Hole effect in beams with a modified thickness profile and extended platform

NASA Astrophysics Data System (ADS)

Tang, Liling; Cheng, Li

2017-03-01

The phenomenon of Acoustics Black Hole (ABH) benefits from the bending wave propagating properties inside a thin-walled structure with power-law thickness variation to achieve zero reflection when the structural thickness approaches zero in the ideal scenario. However, manufacturing an ideally tailored power-law profile of a structure with embedded ABH feature can hardly be achieved in practice. Past research showed that the inevitable truncation at the wedge tip of the structure can significantly weaken the expected ABH effect by creating wave reflections. On the premise of the minimum achievable truncation thickness by the current manufacturing technology, exploring ways to ensure and achieve better ABH effect becomes important. In this paper, we investigate this issue by using a previously developed wavelet-decomposed semi-analytical model on an Euler-Bernoulli beam with a modified power-law profile and an extended platform of constant thickness. Through comparisons with the conventional ABH profile in terms of system loss factor and energy distribution, numerical results show that the modified thickness profile brings about a systematic increase in the ABH effect at mid-to-high frequencies, especially when the truncation thickness is small and the profile parameter m is large. The use of an extended platform further increases the ABH effect to broader the frequency band whilst providing rooms for catering particular low frequency applications.

Grief in the initial adjustment process to the continuing care retirement community.

PubMed

Ayalon, Liat; Green, Varda

2012-12-01

This paper examined the transition to continuing care retirement communities (CCRCs) within the framework of anticipatory and disenfranchised grief. Qualitative interviews with 29 residents and 19 adult children were conducted. Three major thematic categories emerged from the data. The first theme reflected ambivalence, dialectics or uncertainty about the CCRC as manifested by the various names assigned to it by respondents. The second theme reflected the acknowledgement of present and anticipatory losses and grief in response to the move. The final theme reflected respondents' disenfranchisement of their grief and loss and their view of the transition in a positive light. In their early adjustment period, residents and adult children are ambivalent about the transition, but often refrain from acknowledging their losses openly because of the image of the CCRC as a status symbol. Open acknowledgement of losses associated with the transition might be beneficial. Copyright © 2012 Elsevier Inc. All rights reserved.

Optical and adhesive properties of dust deposits on solar mirrors and their effects on specular reflectivity and electrodynamic cleaning for mitigating energy-yield loss

NASA Astrophysics Data System (ADS)

Mazumder, Malay; Yellowhair, Julius; Stark, Jeremy; Heiling, Calvin; Hudelson, John; Hao, Fang; Gibson, Hannah; Horenstein, Mark

2014-10-01

Large-scale solar plants are mostly installed in semi-arid and desert areas. In those areas, dust layer buildup on solar collectors becomes a major cause for energy yield loss. Development of transparent electrodynamic screens (EDS) and their applications for self-cleaning operation of solar mirrors are presented with a primary focus on the removal dust particles smaller than 30 µm in diameter while maintaining specular reflection efficiency < 90%. An EDS consists of thin rectangular array of parallel transparent conducting electrodes deposited on a transparent dielectric surface. The electrodes are insulated from each other and are embedded within a thin transparent dielectric film. The electrodes are activated using three-phase high-voltage pulses at low current (< 1 mA/m2 ). The three-phase electric field charges the deposited particles, lifts them form the substrate by electrostatic forces and propels the dust layer off of the collector's surface by a traveling wave. The cleaning process takes less than 2 minutes; needs energy less than 1 Wh/m2 without requiring any water or manual labor. The reflection efficiency can be restored > 95% of the original clean-mirror efficiency. We briefly present (1) loss of specular reflection efficiency as a function of particle size distribution of deposited dust, and (2) the effects of the electrode design and materials used for minimizing initial loss of specular reflectivity in producing EDS-integrated solar mirrors. Optimization of EDS by using a figure of merit defined by the ratio of dust removal efficiency to the initial loss of specular reflection efficiency is discussed.

One-step fabrication of N-doped CNTs encapsulating M nanoparticles (M = Fe, Co, Ni) for efficient microwave absorption

NASA Astrophysics Data System (ADS)

Ning, Mingqiang; Li, Jingbo; Kuang, Boya; Wang, Chengzhi; Su, Dezhi; Zhao, Yongjie; Jin, Haibo; Cao, Maosheng

2018-07-01

By using a modified non-toxic pyrolysis method, M@NCNTs comprising in-situ formed M nanoparticles encapsulated in nitrogen-doped carbon nanotubes (NCNTs) have been synthesized. Compared to traditional preparation process of M@CNTs (eg: acid-aid treatment to CNTs then decorating M particles onto), this method holds the advantage of free of complicated treatment processes. The M@NCNTs exhibit tightly connected interfaces of M/NCNTs and contain abundant N dopants, which could contribute interfacial polarization and defect-dipole polarization to improving the microwave absorption performance. An intense dielectric relaxation is observed in Fe@NCNTs samples, which further enhances the dielectric loss. As expected, the as-synthesized M@NCNTs composites demonstrate promising candidates in microwave absorption (MWA) application. The minimum reflection loss (RL) of Fe@NCNTs (with 10 wt% loading) is up to -30.43 dB at 3.2 mm, and the effective absorption bandwidth (RL < -10 dB) is as wide as 5.7 GHz which benefits from the neighboring dual absorption peaks induced by the intense dielectric relaxation. Co@NCNTs and Ni@NCNTs also have satisfactory effective absorption bandwidth ∼4.08 and ∼4.72 GHz, respectively. The modified pyrolysis method is low-cost and non-toxic, which could become an industrial technique to synthesize carbonaceous composites for microwave absorption.

Light polarization measurements - A method to determine the specular and diffuse light-scattering properties of both leaves and plant canopies

NASA Technical Reports Server (NTRS)

Vanderbilt, V. C.; Grant, L.

1984-01-01

The contributions of diffuse and specular reflection to the total canopy reflection of sunlight are determined experimentally for wheat at two stages of development using spectroradiometer measurements obtained at 13 wavelengths in the 480-720-nm range with a polarizing film in maximum and minimum signal-amplitude positions. The data and computation techniques are presented in tables, diagrams, and graphs, and the need to take specular reflection into account in constructing models of light/canopy interaction is stressed.

Effect of aluminum substitution on the reflectance spectra of hematite

NASA Technical Reports Server (NTRS)

Morris, R. V.; Lauer, H. V., Jr.; Mendell, W. W.

1982-01-01

Hematite and aluminous hematite were synthesized and the diffuse reflectance spectra were recorded for the region between 0.35 and 1.20 microns. Results show that the near-IR based minimum for the aluminous hematite is shifted longward by about 0.02 microns and is much more shallow. Also, the aluminous specimen is considerably more reflective shortward of approximately 0.55 microns where the ferritic specimen is strongly absorbing. This is noteworthy since the visible slope and the red shoulder are often used in the construction of false color and band ratio images.

The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

NASA Astrophysics Data System (ADS)

Luthra, Deepali; Kumar, Sacheen

2018-05-01

Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

Ethics in nursing education: learning to reflect on care practices.

PubMed

Vanlaere, Linus; Gastmans, Chris

2007-11-01

Providing good care requires nurses to reflect critically on their nursing practices. Ethics education must provide nurses with tools to accomplish such critical reflection. It must also create a pedagogical context in which a caring attitude can be taught and cultivated. To achieve this twofold goal, we argue that the principles of a right-action approach, within which nurses conform to a number of minimum principles, must be integrated into a virtue ethics approach that cultivates a caring attitude. Ethics education that incorporates both the ;critical companionship' method and the use of codes of ethics contributes positively to cultivating critical reflection by nurses.

Spectral changes in conifers subjected to air pollution and water stress: Experimental studies

NASA Technical Reports Server (NTRS)

Westman, Walter E.; Price, Curtis V.

1988-01-01

The roles of leaf anatomy, moisture and pigment content, and number of leaf layers on spectral reflectance in healthy, pollution-stressed, and water-stressed conifer needles were examined experimentally. Jeffrey pine (Pinus jeffreyi) and giant sequoia (Sequoiadendron gigantea) were exposed to ozone and acid mist treatments in fumigation chambers; red pine (Pinus resinosa) needles were artificially dried. Infrared reflectance from stacked needles rose with free water loss. In an air-drying experiment, cell volume reductions induced by loss of turgor caused near-infrared reflectance (TM band 4) to drop after most free water was lost. Under acid mist fumigation, stunting of tissue development similarly reduced band 4 reflectance. Both artificial drying and pollutant fumigation caused a blue shift of the red edge of spectral reflectance curves in conifers, attributable to chlorophyll denaturation. Thematic mapper band ratio 4/3 fell and 5/4 rose with increasing pollution stress on artificial drying. Loss of water by air-drying, freeze-drying, or oven-drying enhanced spectral features, due in part to greater scattering and reduced water absorption. Grinding of the leaf tissue further enhanced the spectral features by increasing reflecting surfaces and path length. In a leaf-stacking experiment, an asymptote in visible and infrared reflectance was reached at 7-8 needle layers of red pine.

Low-Frequency Shallow Water Acoustics (20 to 500 Hz),

DTIC Science & Technology

1986-05-01

developed by Hastrup 49 and the results are shown in Figure V-1. See also Table 11-4. 20- 16.m ./ \\ 12. Fig. V-I. SILT Computed reflection loss...33-39. APL-UW 8606 91 UNIVERSITY OF WASHINGTON • APPLIED PHYSICS LABORATORY 49. O.F. Hastrup , "Some bottom-reflection loss anomalies near grazing and

Minimum resolvable power contrast model

NASA Astrophysics Data System (ADS)

Qian, Shuai; Wang, Xia; Zhou, Jingjing

2018-01-01

Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

Simvastatin in the treatment of asthma: lack of steroid-sparing effect.

PubMed

Cowan, Douglas C; Cowan, Jan O; Palmay, Rochelle; Williamson, Avis; Taylor, D Robin

2010-10-01

Statins have anti-inflammatory actions which in theory are potentially beneficial in asthma. Small trials have failed to show a significant benefit, but a systematic study to evaluate the steroid-sparing effect of statin treatment has not been carried out. A randomised, placebo-controlled, crossover trial was conducted of simvastatin 40 mg at night with simultaneous stepwise reduction of fluticasone propionate dose until loss of control occurred, followed by an increase until regain of control ('minimum' dose required) in 51 patients with asthma and sputum eosinophils (steroid-free) ≥ 2%. 43 patients completed the study. There was no significant difference in 'minimum' inhaled corticosteroid (ICS) dose requirement between simvastatin and placebo: (median (IQR) 50 μg daily (0-250) vs 100 μg daily (0-250), p=0.931). 'Minimum' dose distribution was similar (p=0.269). The fluticasone dose at which loss of control occurred did not differ significantly between simvastatin and placebo (p=0.404). In patients with loss of control in both treatment arms, fluticasone dose at loss of control was similar with simvastatin and placebo (median (IQR) 50 μg daily (0-100) for both, p=0.620). In those patients who reached 0 μg/day (n=18), Astma Control Questionnaire (ACQ) was lower (p=0.037), forced expiratory volume in 1 s (FEV(1)) higher (p<0.01) and sputum eosinophils lower with simvastatin compared with placebo (9.5% compared with 25.4%, p=0.033). Simvastatin does not have clinically important steroid-sparing effects in patients with eosinophilic asthma. In the absence of steroid, simvastatin is associated with minor improvements in symptoms and lung function, and a reduction in sputum eosinophils. Clinical trial number ACTRN12606000531516.

The X-Ray Lightcurve of Eta Carinae: Refinement of the Orbit and Evidence for Phase Dependent Mass Loss

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Ishibashi, K.; Swank, J. H.; Petre, R.; White, Nicholas E. (Technical Monitor)

2000-01-01

We solve the RXTE X-ray lightcurve of the extremely luminous and massive star eta Carinae with a colliding wind emission model to refine the ground-based orbital elements. The sharp decline to X-ray minimum at the end of 1997 fixes the date of the last periastron passage at 1997.95 +/- 0.05, not 1998.13 as derived from ground-based radial velocities. This helps resolve a discrepancy between the ground-based radial velocities and spatially-resolved velocity measures obtained by STIS. The X-ray data are consistent with a mass function f(M) approx. = 1.5, lower than the value f(M) approx. = 7.5 previously reported, so that the masses of eta Carinae and the companion are M(sub eta) greater than or = 80 solar mass and M(sub c) approx. 30 solar mass respectively. In addition the X-ray data suggest that the mass loss rate from eta Carinae is generally less than 3 x 10(exp -4) solar mass/yr, about a factor of 5 lower than that derived from some observations in other wavebands. We could not match the duration of the X-ray minimum with any standard colliding wind model in which the wind is spherically symmetric and the mass loss rate is constant. However we show that we can match the variations around X-ray minimum if we include an increase of a factor of approx. 20 in the mass loss rate from eta Carinae for approximately 80 days following periastron. If real, this excess in M would be the first evidence of enhanced mass flow off the primary when the two stars are close (presumably driven by tidal interactions). Our interpretation of the X-ray data suggest that the ASCA and RXTE X-ray spectra near the X-ray minimum are significantly contaminated by unresolved hard emission (E greater than or = 2 keV) from sonic other nearby source, probably associated with scattering of tile colliding wind emission by circumstellar dust. Based on the X-ray fluxes the distance to n Carinae is 2300 pc with formal uncertainties of only approx. 10%.

Effect of shrink wrap packaging for maintaining quality of cucumber during storage.

PubMed

Dhall, Rajinder Kumar; Sharma, Sanjeev R; Mahajan, B V C

2012-08-01

Immature green cucumber cv. 'Padmini' fruits were individually shrink wrapped with Cryovac D955 (60 guage) film and stored at 12 ± 1 °C, 90-95% RH as well as ambient conditions (29-33 °C, 65-70% RH). At 12 ± 1 °C and 90-95% RH, individual shrink wrapped cucumber recorded minimum Physiological loss in weight (0.66%) as compared with unwrapped fruits (11.11%) at the end of refrigerated storage (15 days). The softening (loss of firmness) was maximum (1304.6-876.6 g force) in unwrapped cucumbers whereas in shrink wrapping, minimum loss in firmness (1304.6-1065.3 g force) was observed after 12 days storage at 12 ± 1 °C and 90-95% RH but greater loss of weight and firmness makes the control cucumbers unmarketable after 9 days of storage. There were no rotting at all both in shrink wrapped and unwrapped cucumbers upto 15 days of storage at 12 ± 1 °C and 90-95% RH. After 15 days storage of shrink wrapped cucumbers at 12 ± 1 °C and 90-95% RH, there was loss of green colour and development of yellowness and decay. The sensory attributes score was highest in shrink wrapped cucumbers as compared to unwrapped cucumbers at end of both storage conditions. Thus it can be concluded that individual shrink wrapped cucumber can be stored well upto 15 days at 12 ± 1 °C and 90-95% RH and for 5 days at ambient conditions (29-33 °C, 65-70% RH) with maximum retention of green colour, no spoilage, minimum weight and firmness loss and very good sensory quality attributes whereas, unwrapped fruits can be stored well upto 9 days at 12 ± 1 °C and 90-95% RH and for 2 days at ambient conditions with maximum retention of physico-chemical quality attributes.

Determination of acoustic properties of thin polymer films utilizing the frequency dependence of the reflection coefficient of ultrasound.

PubMed

Tohmyoh, Hironori; Sakamoto, Yuhei

2015-11-01

This paper reports on a technique to measure the acoustic properties of a thin polymer film utilizing the frequency dependence of the reflection coefficient of ultrasound reflected back from a system comprising a reflection plate, the film, and a material that covers the film. The frequency components of the echo reflected from the back of the plate, where the film is attached, take their minimum values at the resonant frequency, and from these frequency characteristics, the acoustic impedance, sound velocity, and the density of the film can be determined. We applied this technique to characterize an ion exchange membrane, which has high water absorbability, and successfully determined the acoustic properties of the membrane without getting it wet.

Routing and spectrum assignment based on ant colony optimization of minimum consecutiveness loss in elastic optical networks

NASA Astrophysics Data System (ADS)

Wang, Fu; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Tian, Qinghua; Zhang, Qi; Rao, Lan; Tian, Feng; Luo, Biao; Liu, Yingjun; Tang, Bao

2016-10-01

Elastic Optical Networks are considered to be a promising technology for future high-speed network. In this paper, we propose a RSA algorithm based on the ant colony optimization of minimum consecutiveness loss (ACO-MCL). Based on the effect of the spectrum consecutiveness loss on the pheromone in the ant colony optimization, the path and spectrum of the minimal impact on the network are selected for the service request. When an ant arrives at the destination node from the source node along a path, we assume that this path is selected for the request. We calculate the consecutiveness loss of candidate-neighbor link pairs along this path after the routing and spectrum assignment. Then, the networks update the pheromone according to the value of the consecutiveness loss. We save the path with the smallest value. After multiple iterations of the ant colony optimization, the final selection of the path is assigned for the request. The algorithms are simulated in different networks. The results show that ACO-MCL algorithm performs better in blocking probability and spectrum efficiency than other algorithms. Moreover, the ACO-MCL algorithm can effectively decrease spectrum fragmentation and enhance available spectrum consecutiveness. Compared with other algorithms, the ACO-MCL algorithm can reduce the blocking rate by at least 5.9% in heavy load.

Bottom-Interating Ocean Acoustics. Proceedings of a Conference held at SACLANTCEN on 9-13 June 1980.

DTIC Science & Technology

1980-07-15

scattering by John H. Hanrahan (M) 11 Some bottom-reflection loss anomalies near grazing and their effect on propagation in shallow water by Ole F. Hastrup (Q...SACLANTCEN CP-27 11 SOME BOTTOM-REFLECTION LOSS ANOMALIES NEAR GRAZING AND THEIR EFFECT ON PROPAGATION IN SHALLOW WATER by Ole F. Hastrup SACLANT ASW

Reducing heat loss from the energy absorber of a solar collector

DOEpatents

Chao, Bei Tse; Rabl, Ari

1976-01-01

A device is provided for reducing convective heat loss in a cylindrical radiant energy collector. It includes a curved reflective wall in the shape of the arc of a circle positioned on the opposite side of the exit aperture from the reflective side walls of the collector. Radiant energy exiting the exit aperture is directed by the curved wall onto an energy absorber such that the portion of the absorber upon which the energy is directed faces downward to reduce convective heat loss from the absorber.

Computer simulations of optimum boost and buck-boost converters

NASA Technical Reports Server (NTRS)

Rahman, S.

1982-01-01

The development of mathematicl models suitable for minimum weight boost and buck-boost converter designs are presented. The facility of an augumented Lagrangian (ALAG) multiplier-based nonlinear programming technique is demonstrated for minimum weight design optimizations of boost and buck-boost power converters. ALAG-based computer simulation results for those two minimum weight designs are discussed. Certain important features of ALAG are presented in the framework of a comprehensive design example for boost and buck-boost power converter design optimization. The study provides refreshing design insight of power converters and presents such information as weight annd loss profiles of various semiconductor components and magnetics as a function of the switching frequency.

An evaluation of benthic macroinvertebrate biomass methodology : Part 1. Laboratory analytical methods.

PubMed

Mason, W T; Lewis, P A; Weber, C I

1983-03-01

Evaluation of analytical methods employed for wet weight (live or preserved samples) of benthic macroinvertebrates reveals that centrifugation at 140 x gravity for one minute yields constant biomass estimates. Less relative centrifugal force increases chance of incomplete removal of body moisture and results in weighing error, while greater force may rupture fragile macroinvertebrates, such as mayflies. Duration of specimen exposure in ethanol, formalin, and formol (formaling-ethanol combinations) causes significant body weight loss with within 48 hr formalin and formol cause less body weight loss than ethanol. However, as all preservatives tested cause body weight loss, preservation time of samples collected for comparative purposes should be treated uniformly. Dry weight estimates of macroinvertebrates are not significantly affected by kind of preservative or duration of exposure. Constant dry weights are attained by oven drying at 103 °C at a minimum of four hours or vacuum oven drying (15 inches of mercury pressure) at 103 °C for a minimum of one hour. Although requiring more time in preparation than oven drying and inalterably changing specimen body shape, freeze drying (10 microns pressure, -55 °C, 24 hr) provides constant dry weights and is advantageous for long term sample storage by minimizing curatorial attention. Constant ash-free dry weights of macroinvertebrate samples are attained by igniting samples at 500-550 °C for a minimum of one hour with slow cooling to room temperature in desiccators before weighing.

Packaging of microwave integrated circuits operating beyond 100 GHz

NASA Technical Reports Server (NTRS)

Samoska, L.; Daniel, E.; Sokolov, V.; Sommerfeldt, S.; Bublitz, J.; Olson, K.; Gilbert, B.; Chow, D.

2002-01-01

Several methods of packaging high speed (75-330 GHz) InP HEMT MMIC devices are discussed. Coplanar wirebonding is presented with measured insertion loss of less than 0.5dB and return loss better than -17 dB from DC to 110 GHz. A motherboard/daughterboard packaging scheme is presented which supports minimum loss chains of MMICs using this coplanar wirebonding method. Split waveguide block packaging approaches are presented in G-band (140-220 GHz) with two types of MMIC-waveguide transitions: E-plane probe andantipodal finline.

Wing flapping with minimum energy. [minimize the drag for a bending moment at the wing root

NASA Technical Reports Server (NTRS)

Jones, R. T.

1980-01-01

For slow flapping motions it is found that the minimum energy loss occurs when the vortex wake moves as a rigid surface that rotates about the wing root - a condition analogous to that determined for a slow-turning propeller. The optimum circulation distribution determined by this condition differs from the elliptic distribution, showing a greater concentration of lift toward the tips. It appears that very high propulsive efficiencies are obtained by flapping.

NONLINEAR AND FIBER OPTICS: Transmission of submillimeter laser beams along hollow-core dielectric waveguides

NASA Astrophysics Data System (ADS)

Epishin, V. A.; Maslov, Vyacheslav A.; Ryabykh, V. N.; Svich, V. A.; Topkov, A. N.

1990-04-01

Theoretical and experimental investigations are reported of the propagation of axisymmetric linearly polarized laser radiation beams along hollow-core dielectric waveguides. The conditions for transmission with minimum distortion of the complex amplitude and minimum excitation losses are established for beams in the form of Gaussian-Laguerre modes. A scaling relationship is obtained for the attenuation constant of the EH11 mode in glass waveguides acting as transmission lines and for laser cells handling submillimeter wavelengths.

FIBER AND INTEGRATED OPTICS: Polarization characteristics of anisotropic single-mode fiber waveguides

NASA Astrophysics Data System (ADS)

Arutyunyan, Z. É.; Grudinin, A. B.; Gur'yanov, A. N.; Gusovskiĭ, D. D.; Dianov, Evgenii M.; Ignat'ev, S. V.; Smirnov, O. B.; Khrushchev, I. Yu

1990-01-01

An experimental investigation was made of the polarization characteristics of anisotropic fiber waveguides with an elliptic stress-inducing cladding, operating in a wide spectral range. The maximum birefringence amounted to 3.4 × 10 - 4, the minimum mode coupling parameter was 2.5 × 10 - 5 m - 1 (λ = 1.1 μm), and the minimum losses were 0.7 dB/km (λ = 1.5 μm). A qualitative comparison was made with the theoretical data.

The SMM Model as a Boundary Value Problem Using the Discrete Diffusion Equation

NASA Technical Reports Server (NTRS)

Campbell, Joel

2007-01-01

A generalized single step stepwise mutation model (SMM) is developed that takes into account an arbitrary initial state to a certain partial difference equation. This is solved in both the approximate continuum limit and the more exact discrete form. A time evolution model is developed for Y DNA or mtDNA that takes into account the reflective boundary modeling minimum microsatellite length and the original difference equation. A comparison is made between the more widely known continuum Gaussian model and a discrete model, which is based on modified Bessel functions of the first kind. A correction is made to the SMM model for the probability that two individuals are related that takes into account a reflecting boundary modeling minimum microsatellite length. This method is generalized to take into account the general n-step model and exact solutions are found. A new model is proposed for the step distribution.

The SMM model as a boundary value problem using the discrete diffusion equation.

PubMed

Campbell, Joel

2007-12-01

A generalized single-step stepwise mutation model (SMM) is developed that takes into account an arbitrary initial state to a certain partial difference equation. This is solved in both the approximate continuum limit and the more exact discrete form. A time evolution model is developed for Y DNA or mtDNA that takes into account the reflective boundary modeling minimum microsatellite length and the original difference equation. A comparison is made between the more widely known continuum Gaussian model and a discrete model, which is based on modified Bessel functions of the first kind. A correction is made to the SMM model for the probability that two individuals are related that takes into account a reflecting boundary modeling minimum microsatellite length. This method is generalized to take into account the general n-step model and exact solutions are found. A new model is proposed for the step distribution.

Low-loss optical waveguides in β-BBO crystal fabricated by femtosecond-laser writing

NASA Astrophysics Data System (ADS)

Li, Ziqi; Cheng, Chen; Romero, Carolina; Lu, Qingming; Vázquez de Aldana, Javier Rodríguez; Chen, Feng

2017-11-01

We report on the fabrication and characterization of β-BBO depressed cladding waveguides fabricated by femtosecond-laser writing with no significant changes in the waveguide lattice microstructure. The waveguiding properties and the propagation losses of the cladding structures are investigated, showing good transmission properties at wavelengths of 400 and 800 nm along TM polarization. The minimum propagation losses are measured to be as low as 0.19 dB/cm at wavelength of 800 nm. The well-preserved waveguide lattice microstructure and good guiding performances with low propagation losses suggest the potential applications of the cladding waveguides in β-BBO crystal as novel integrated photonic devices.

A theoretical and practical clarification on the calculation of reflection loss for microwave absorbing materials

NASA Astrophysics Data System (ADS)

Liu, Ying; Zhao, Kun; Drew, Michael G. B.; Liu, Yue

2018-01-01

Reflection loss is usually calculated and reported as a function of the thickness of microwave absorption material. However, misleading results are often obtained since the principles imbedded in the popular methods contradict the fundamental facts that electromagnetic waves cannot be reflected in a uniform material except when there is an interface and that there are important differences between the concepts of characteristic impedance and input impedance. In this paper, these inconsistencies have been analyzed theoretically and corrections provided. The problems with the calculations indicate a gap between the background knowledge of material scientists and microwave engineers and for that reason a concise review of transmission line theory is provided along with the mathematical background needed for a deeper understanding of the theory of reflection loss. The expressions of gradient, divergence, Laplacian, and curl operators in a general orthogonal coordinate system have been presented including the concept of reciprocal vectors. Gauss's and Stokes's theorems have been related to Green's theorem in a novel way.

Development of an 83.2 MHz, 3.2 kW solid-state RF amplifier using Wilkinson power divider and combiner for a 10 MeV cyclotron

NASA Astrophysics Data System (ADS)

Song, Ho Seung; Ghergherehchi, Mitra; Oh, Seyoung; Chai, Jong Seo

2017-03-01

We design a stripline-type Wilkinson power divider and combiner for a 3.2 kW solid-state radio frequency (RF) amplifier module and optimize this setup. A Teflon-based printed circuit board is used in the power combiner to transmit high RF power efficiently in the limited space. The reflection coefficient (S11) and insertion loss (S21) related to impedance matching are characterized to determine the optimization process. The resulting two-way divider reflection coefficient and insertion loss were -48.00 dB and -3.22 dB, respectively. The two-way power combiner reflection coefficient and insertion loss were -20 dB and -3.3 dB, respectively. Moreover, the 3.2 kW solid-state RF power test results demonstrate that the proposed power divider and combiner exhibit a maximum efficiency value of 71.3% (combiner loss 5%) at 48 V supply voltage.

Electron Cyclotron Radiation, Related Power Loss, and Passive Current Drive in Tokamaks: A Review

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

Fidone, Ignazio; Giruzzi, Gerardo; Granata, Giovanni

2001-01-15

A critical review on emission of weakly damped, high-harmonics electron cyclotron radiation, the related synchrotron power loss, and passive current drive in tokamaks with a fish-scale first wall is presented. First, the properties of overlapping harmonics are discussed using general analytical formulas and numerical applications. Next, the radiation power loss and efficiency of passive current drive in tokamak reactors are derived for the asymmetric fish-scale first wall. The radiation power loss is determined by the direction-averaged reflection coefficient {sigma}{sub 0} and the passive current drive by the differential reflectivity {delta}{sigma}/(1 - {sigma}{sub 0}). Finally, the problem of experimental investigations ofmore » the high harmonics radiation spectra, of {sigma}{sub 0} and {delta}{sigma}/(1 - {sigma}{sub 0}) in existing and next-step tokamaks, is discussed. Accurate measurements of the radiation spectra and the fish-scale reflectivity can be performed at arbitrary electron temperature using a partial fish-scale structure located near the tokamak equatorial plane.« less

The Economic Impact of Blindness in Europe.

PubMed

Chakravarthy, Usha; Biundo, Eliana; Saka, Rasit Omer; Fasser, Christina; Bourne, Rupert; Little, Julie-Anne

2017-08-01

To estimate the annual loss of productivity from blindness and moderate to severe visual impairment (MSVI) in the population aged >50 years in the European Union (EU). We estimated the cost of lost productivity using three simple models reported in the literature based on (1) minimum wage (MW), (2) gross national income (GNI), and (3) purchasing power parity-adjusted gross domestic product (GDP-PPP) losses. In the first two models, assumptions included that all individuals worked until 65 years of age, and that half of all visual impairment cases in the >50-year age group would be in those aged between 50 and 65 years. Loss of productivity was estimated to be 100% for blind individuals and 30% for those with MSVI. None of these models included direct medical costs related to visual impairment. The estimated number of blind people in the EU population aged >50 years is ~1.28 million, with a further 9.99 million living with MSVI. Based on the three models, the estimated cost of blindness is €7.81 billion, €6.29 billion and €17.29 billion and that of MSVI €18.02 billion, €24.80 billion and €39.23 billion, with their combined costs €25.83 billion, €31.09 billion and €56.52 billion, respectively. The estimates from the MW and adjusted GDP-PPP models were generally comparable, whereas the GNI model estimates were higher, probably reflecting the lack of adjustment for unemployment. The cost of blindness and MSVI in the EU is substantial. Wider use of available cost-effective treatment and prevention strategies may reduce the burden significantly.

Reflection/suppression coatings for 900 - 1200 A radiation

NASA Technical Reports Server (NTRS)

Edelstein, Jerry

1989-01-01

The design and performance of multiple-layer, selective-reflection, selective-suppression coatings for the 900 - 1200 A band are described. These coatings are designed to optimize both high reflectivity at a desirable wavelength and low reflectivity at an undesirable wavelength. The minimum structure for a selective coating consists of a thin metal or metal oxide layer (50 - 150 A thickness) over an aluminum substrate protected with a semi-transparent dielectric (100 - 1000 A thickness). Predicted coating performance is strongly effected by varying the layer combination and thickness. A graphical method of optimizing the coating layer structure is developed. Aluminum, silicon, their oxides, and gold have been investigated as coating layer materials. A very simple coating with a 1026 to 1216 A reflectivity ratio greater than 100 was fabricated. Such reflection/suppression coatings may be of great utility to spaceborne EUV spectrographs.

Preparation and microwave-infrared absorption of reduced graphene oxide/Cu-Ni ferrite/Al2O3 composites

NASA Astrophysics Data System (ADS)

De-yue, Ma; Xiao-xia, Li; Yu-xiang, Guo; Yu-run, Zeng

2018-01-01

Reduced graphene oxide (RGO)/Cu-Ni ferrite/Al2O3 composite was prepared by solvothermal method, and its properties were characterized by SEM, x-ray diffraction, energy-dispersive x-ray spectroscopy and FTIR. The electromagnetic parameters in 2-18 GHz and mid-infrared (IR) spectral transmittance of the composite were measured, respectively. The results show that Cu0.7Ni0.3Fe2O4 nanoparticles with an average size of tens nanometers adsorb on surface of RGO, and meanwhile, Al2O3 nanoparticles adhere to the surface of Cu0.7Ni0.3Fe2O4 nanoparticles and RGO. The composite has both dielectric and magnetic loss mechanism. Its reflection loss is lower than -19 dB in 2-18 GHz, and the maximum of -23.2 dB occurs at 15.6 GHz. With the increasing of Al2O3 amount, its reflection loss becomes lower and the maximum moves towards low frequency slightly. Compared with RGO/Cu-Ni ferrite composites, its magnetic loss and reflection loss slightly reduce with the increasing of Al2O3 amount, and the maximum of reflection loss shifts from a low frequency to a high one. However, its broadband IR absorption is significantly enhanced owing to nano-Al2O3. Therefore, RGO/Cu-Ni ferrite/Al2O3 composites can be used as excellent broadband microwave and IR absorbing materials, and maybe have broad application prospect in electromagnetic shielding, IR absorbing and coating materials.

APPARATUS FOR MINIMIZING ENERGY LOSSES FROM MAGNETICALLY CONFINED VOLUMES OF HOT PLASMA

DOEpatents

Post, R.F.

1961-10-01

An apparatus is described for controlling electron temperature in plasma confined in a Pyrotron magnetic containment field. Basically the device comprises means for directing low temperature electrons to the plasma in controlled quantities to maintain a predetermined optimum equilibrium electron temperature whereat minimum losses of plasma ions due to ambipolar effects and energy damping of the ions due to dynamical friction with the electrons occur. (AEC)

SACR ADVance 3-D Cartesian Cloud Cover (SACR-ADV-3D3C) product

DOE Data Explorer

Meng Wang, Tami Toto, Eugene Clothiaux, Katia Lamer, Mariko Oue

2017-03-08

SACR-ADV-3D3C remaps the outputs of SACRCORR for cross-wind range-height indicator (CW-RHI) scans to a Cartesian grid and reports reflectivity CFAD and best estimate domain averaged cloud fraction. The final output is a single NetCDF file containing all aforementioned corrected radar moments remapped on a 3-D Cartesian grid, the SACR reflectivity CFAD, a profile of best estimate cloud fraction, a profile of maximum observable x-domain size (xmax), a profile time to horizontal distance estimate and a profile of minimum observable reflectivity (dBZmin).

Performance enhancement of linear stirling cryocoolers

NASA Astrophysics Data System (ADS)

Korf, Herbert; Ruehlich, Ingo; Wiedmann, Th.

2000-12-01

Performance and reliability parameters of the AIM Stirling coolers have been presented in several previous publications. This paper focuses on recent developments at AIM for the COP improvement of cryocoolers in IR-detectors and systems applications. Improved COP of cryocoolers is a key for optimized form factors, weight and reliability. In addition, some systems are critical for minimum input power and consequently minimum electromagnetic interference or magnetic stray fields, heat sinking or minimum stress under high g-level, etc. Although performance parameters and loss mechanism are well understood and can be calculated precisely, several losses still had been excessive and needed to be minimized. The AIM program is based on the SADA I cryocooler, which now is optimized to carry 4.3 W net heat load at 77K. As this program will lead into applications on a space platform, in a next step AIM is introducing flexure bearings and in a final step, an advanced pulse tube cold head will be implemented. The performance of the SADA II cooler is also improved by using the same tools and methods than used for the performance increase of the SADA I cooler by a factor of two. The main features are summarized together with measured or calculated performance data.

Selection of the best chemical pretreatment for lignocellulosic substrate Prosopis juliflora.

PubMed

Naseeruddin, Shaik; Srilekha Yadav, K; Sateesh, L; Manikyam, Ananth; Desai, Suseelendra; Venkateswar Rao, L

2013-05-01

Pretreatment is a pre-requisite step in bioethanol production from lignocellulosic biomass required to remove lignin and increase the porosity of the substrate for saccharification. In the present study, chemical pretreatment of Prosopis juliflora was performed using alkali (NaOH, KOH, and NH3), reducing agents (Na2S2O4, Na2SO3) and NaClO2 in different concentration ranges at room temperature (30±2 °C) to remove maximum lignin with minimum sugar loss. Further, biphasic acid hydrolysis of the various pretreated substrates was performed at mild temperatures. Considering the amount of holocellulose hydrolyzed and inhibitors released during hydrolysis, best chemical pretreatment was selected. Among all the chemicals investigated, pretreatment with sodium dithionite at concentration of 2% (w/v) removed maximum lignin (80.46±1.35%) with a minimum sugar loss (2.56±0.021%). Subsequent biphasic acid hydrolysis of the sodium dithionite pretreated substrate hydrolyzed 40.09±1.22% of holocellulose and released minimum amount of phenolics (1.04±0.022 g/L) and furans (0.41±0.012 g/L) in the hydrolysate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Linking internal and external bacterial community control gives mechanistic framework for pelagic virus-to-bacteria ratios.

PubMed

Våge, Selina; Pree, Bernadette; Thingstad, T Frede

2016-11-01

For more than 25 years, virus-to-bacteria ratios (VBR) have been measured and interpreted as indicators of the importance of viruses in aquatic ecosystems, yet a generally accepted theory for understanding mechanisms controlling VBR is still lacking. Assuming that the denominator (total bacterial abundance) is primarily predator controlled, while viral lysis compensates for host growth rates exceeding this grazing loss, the numerator (viral abundance) reflects activity differences between prokaryotic hosts. VBR is then a ratio between mechanisms generating structure within the bacterial community and interactions between different plankton functional types controlling bacterial community size. We here show how these arguments can be formalized by combining a recently published model for co-evolutionary host-virus interactions, with a previously published "minimum" model for the microbial food web. The result is a framework where viral lysis links bacterial diversity to microbial food web structure and function, creating relationships between different levels of organization that are strongly modified by organism-level properties such as cost of resistance. © 2016 The Authors. Environmental Microbiology Reports published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Influence of MnO2 decorated Fe nano cauliflowers on microwave absorption and impedance matching of polyvinylbutyral (PVB) matrix

NASA Astrophysics Data System (ADS)

Bora, Pritom J.; Porwal, Mayuri; Vinoy, K. J.; Ramamurthy, Praveen C.; Madras, Giridhar

2016-09-01

In this work, a promising, polyvinyl butryl (PVB)-MnO2 decorated Fe composite was synthesised and microwave absorption properties were studied for the most important frequency ranges i.e., X-band (8.2-12.4 GHz) and Ku-band (12.4-18 GHz). The microwave absorption of Fe nano cauliflower structure can be enhanced by MnO2 nanofiber coating. 10 wt% Fe-MnO2 nano cauliflower loaded PVB composite films (2 mm thick) shows an appreciable increase in microwave absorption properties. In X-band, the reflection loss (RL) of this composite decreases almost linearly to -7.5 dB, whereas in the Ku-band the minimum RL was found to be -15.7 dB at 14.7 GHz. Here it was observed that impedance matching is the primarily important factor responsible for enhanced microwave absorption. Further, enhancement of EM attenuation constant (α), dielectrics, scattering attenuation also bolsters the obtained results. This polymer composite can be considered as a novel microwave absorbing coating material.

Phylogenetic relationships of the Fox (Forkhead) gene family in the Bilateria

NASA Technical Reports Server (NTRS)

Mazet, Francoise; Yu, Jr Kai; Liberles, David A.; Holland, Linda Z.; Shimeld, Sebastian M.

2003-01-01

The Forkhead or Fox gene family encodes putative transcription factors. There are at least four Fox genes in yeast, 16 in Drosophila melanogaster (Dm) and 42 in humans. Recently, vertebrate Fox genes have been classified into 17 groups named FoxA to FoxQ. Here, we extend this analysis to invertebrates, using available sequences from D. melanogaster, Anopheles gambiae (Ag), Caenorhabditis elegans (Ce), the sea squirt Ciona intestinalis (Ci) and amphioxus Branchiostoma floridae (Bf), from which we also cloned several Fox genes. Phylogenetic analyses lend support to the previous overall subclassification of vertebrate genes, but suggest that four subclasses (FoxJ, L, N and Q) could be further subdivided to reflect their relationships to invertebrate genes. We were unable to identify orthologs of Fox subclasses E, H, I, J, M and Q1 in D. melanogaster, A. gambiae or C. elegans, suggesting either considerable loss in ecdysozoans or the evolution of these subclasses in the deuterostome lineage. Our analyses suggest that the common ancestor of protostomes and deuterostomes had a minimum complement of 14 Fox genes.

Weight Loss and Comorbidity Resolution 3 Years After Bariatric Surgery-an Indian Perspective.

PubMed

Nasta, Amrit Manik; Goel, Ramen; Dharia, Shefali; Goel, Madhu; Hamrapurkar, Shireen

2018-04-03

Bariatric surgery has seen a sharp rise in India in the last decade. India is one of the 10 most obese nations of the world, ranking second in number of type 2 diabetics. To evaluate clinical outcomes of bariatric surgery after 3 years of follow-up in terms of weight loss, co-morbidity resolution, complaints of gastroesophageal reflux disease and weight regain. All patients who underwent bariatric surgery from January to December 2013 with a minimum follow-up of 3 years were included in the study. Their demographic, preoperative, and postoperative data were prospectively maintained on Microsoft Office Excel and analyzed statistically. One hundred seventy-eight patients (157 lap. sleeve gastrectomy and 21 patients lap. RYGB) completed 3 years of follow-up. In the LSG group, patients had a pre-operative BMI 44.8 ± 8.33 kg/sq. m (mean ± S.D.) and excess body weight 52.3 ± 23.0 kg. In the RYGB group, pre-operative BMI was 42.7 ± 8.82 kg/sq. m and excess body weight 45 ± 18.7 kg. In the LSG group, % excess weight loss (EWL) at 1 year was 87.6 ± 24.4% and 3 years was 71.8 ± 26.7%. In the RYGB group, % EWL at 1 year was 97.2 ± 27.3% and at 3 years was 85.8 ± 25.3%. Diabetes resolution was seen in 32 (80%) in LSG group and 11 (91.7%) in RYGB group (Figs. 1, 2, 3, and 4). Our study reflects that there is no statistically significant difference between outcomes of sleeve gastrectomy and Roux-en-Y gastric bypass surgery in terms of weight loss and diabetes resolution at 3 years.

Evaluating of the spatial heterogeneity of soil loss tolerance and its effects on erosion risk in the carbonate areas of southern China

NASA Astrophysics Data System (ADS)

Li, Yue; Bai, Xiao Yong; Jie Wang, Shi; Qin, Luo Yi; Chao Tian, Yi; Jie Luo, Guang

2017-05-01

Soil loss tolerance (T value) is one of the criteria in determining the necessity of erosion control measures and ecological restoration strategy. However, the validity of this criterion in subtropical karst regions is strongly disputed. In this study, T value is calculated based on soil formation rate by using a digital distribution map of carbonate rock assemblage types. Results indicated a spatial heterogeneity and diversity in soil loss tolerance. Instead of only one criterion, a minimum of three criteria should be considered when investigating the carbonate areas of southern China because the one region, one T value concept may not be applicable to this region. T value is proportionate to the amount of argillaceous material, which determines the surface soil thickness of the formations in homogenous carbonate rock areas. Homogenous carbonate rock, carbonate rock intercalated with clastic rock areas and carbonate/clastic rock alternation areas have T values of 20, 50 and 100 t/(km2 a), and they are extremely, severely and moderately sensitive to soil erosion. Karst rocky desertification (KRD) is defined as extreme soil erosion and reflects the risks of erosion. Thus, the relationship between T value and erosion risk is determined using KRD as a parameter. The existence of KRD land is unrelated to the T value, although this parameter indicates erosion sensitivity. Erosion risk is strongly dependent on the relationship between real soil loss (RL) and T value rather than on either erosion intensity or the T value itself. If RL > > T, then the erosion risk is high despite of a low RL. Conversely, if T > > RL, then the soil is safe although RL is high. Overall, these findings may clarify the heterogeneity of T value and its effect on erosion risk in a karst environment.

Divergence and Convergence of Risky Decision Making Across Prospective Gains and Losses: Preferences and Strategies

PubMed Central

Kurnianingsih, Yoanna A.; Mullette-Gillman, O'Dhaniel A.

2015-01-01

People choose differently when facing potential gains than when facing potential losses. Clear gross differences in decision making between gains and losses have been empirically demonstrated in numerous studies (e.g., framing effect, risk preference, loss aversion). However, theories maintain that there are strong underlying connections (e.g., reflection effect). We investigated the relationship between gains and losses decision making, examining risk preferences, and choice strategies (the reliance on option information) using a monetary gamble task with interleaved trials. For risk preferences, participants were on average risk averse in the gains domain and risk neutral/seeking in the losses domain. We specifically tested for a theoretically hypothesized correlation between individual risk preferences across the gains and losses domains (the reflection effect), but found no significant relationship in the predicted direction. Interestingly, despite the lack of reflected risk preferences, cross-domain risk preferences were still informative of individual choice behavior. For choice strategies, in both domains participants relied more heavily on the maximizing strategy than the satisficing strategy, with increased reliance on the maximizing strategy in the losses domain. Additionally, while there is no mathematical reliance between the risk preference and strategy metrics, within both domains there were significant relationships between risk preferences and strategies—the more participants relied upon the maximizing strategy the more risk neutral they were (equating value and utility maximization). These results demonstrate the complexity of gains and losses decision making, indicating the apparent contradiction that their underlying cognitive/neural processes are both dissociable and overlapping. PMID:26733779

Divergence and Convergence of Risky Decision Making Across Prospective Gains and Losses: Preferences and Strategies.

PubMed

Kurnianingsih, Yoanna A; Mullette-Gillman, O'Dhaniel A

2015-01-01

People choose differently when facing potential gains than when facing potential losses. Clear gross differences in decision making between gains and losses have been empirically demonstrated in numerous studies (e.g., framing effect, risk preference, loss aversion). However, theories maintain that there are strong underlying connections (e.g., reflection effect). We investigated the relationship between gains and losses decision making, examining risk preferences, and choice strategies (the reliance on option information) using a monetary gamble task with interleaved trials. For risk preferences, participants were on average risk averse in the gains domain and risk neutral/seeking in the losses domain. We specifically tested for a theoretically hypothesized correlation between individual risk preferences across the gains and losses domains (the reflection effect), but found no significant relationship in the predicted direction. Interestingly, despite the lack of reflected risk preferences, cross-domain risk preferences were still informative of individual choice behavior. For choice strategies, in both domains participants relied more heavily on the maximizing strategy than the satisficing strategy, with increased reliance on the maximizing strategy in the losses domain. Additionally, while there is no mathematical reliance between the risk preference and strategy metrics, within both domains there were significant relationships between risk preferences and strategies-the more participants relied upon the maximizing strategy the more risk neutral they were (equating value and utility maximization). These results demonstrate the complexity of gains and losses decision making, indicating the apparent contradiction that their underlying cognitive/neural processes are both dissociable and overlapping.

Suppression of Growth by Multiplicative White Noise in a Parametric Resonant System

NASA Astrophysics Data System (ADS)

Ishihara, Masamichi

2015-02-01

The growth of the amplitude in a Mathieu-like equation with multiplicative white noise is studied. To obtain an approximate analytical expression for the exponent at the extremum on parametric resonance regions, a time-interval width is introduced. To determine the exponents numerically, the stochastic differential equations are solved by a symplectic numerical method. The Mathieu-like equation contains a parameter α determined by the intensity of noise and the strength of the coupling between the variable and noise; without loss of generality, only non-negative α can be considered. The exponent is shown to decrease with α, reach a minimum and increase after that. The minimum exponent is obtained analytically and numerically. As a function of α, the minimum at α≠0, occurs on the parametric resonance regions of α=0. This minimum indicates suppression of growth by multiplicative white noise.

Incorporating patient-preference evidence into regulatory decision making.

PubMed

Ho, Martin P; Gonzalez, Juan Marcos; Lerner, Herbert P; Neuland, Carolyn Y; Whang, Joyce M; McMurry-Heath, Michelle; Hauber, A Brett; Irony, Telba

2015-10-01

Patients have a unique role in deciding what treatments should be available for them and regulatory agencies should take their preferences into account when making treatment approval decisions. This is the first study designed to obtain quantitative patient-preference evidence to inform regulatory approval decisions by the Food and Drug Administration Center for Devices and Radiological Health. Five-hundred and forty United States adults with body mass index (BMI) ≥ 30 kg/m(2) evaluated tradeoffs among effectiveness, safety, and other attributes of weight-loss devices in a scientific survey. Discrete-choice experiments were used to quantify the importance of safety, effectiveness, and other attributes of weight-loss devices to obese respondents. A tool based on these measures is being used to inform benefit-risk assessments for premarket approval of medical devices. Respondent choices yielded preference scores indicating their relative value for attributes of weight-loss devices in this study. We developed a tool to estimate the minimum weight loss acceptable by a patient to receive a device with a given risk profile and the maximum mortality risk tolerable in exchange for a given weight loss. For example, to accept a device with 0.01 % mortality risk, a risk tolerant patient will require about 10 % total body weight loss lasting 5 years. Patient preference evidence was used make regulatory decision making more patient-centered. In addition, we captured the heterogeneity of patient preferences allowing market approval of effective devices for risk tolerant patients. CDRH is using the study tool to define minimum clinical effectiveness to evaluate new weight-loss devices. The methods presented can be applied to a wide variety of medical products. This study supports the ongoing development of a guidance document on incorporating patient preferences into medical-device premarket approval decisions.

Periodontal soft tissue non-root coverage procedures: a consensus report from the AAP Regeneration Workshop.

PubMed

Scheyer, E Todd; Sanz, Mariano; Dibart, Serge; Greenwell, Henry; John, Vanchit; Kim, David M; Langer, Laureen; Neiva, Rodrigo; Rasperini, Giulio

2015-02-01

Soft tissue grafting for the purposes of increasing the width of keratinized tissue (KT) is an important aspect of periodontal treatment. A systematic review was analyzed, focusing on non-root coverage tissue grafts. The references were updated to reflect the current literature. To formulate the consensus report, group members submitted any new literature related to the topic that met criteria fitting the systematic review, and this information was reviewed for inclusion in this report. A consensus report was developed to summarize the findings from the systematic review and to guide clinicians in their treatment decision-making process. Forty-six articles met the criteria for inclusion in the final analysis, and two articles were added that were used to formulate this consensus report. A list of eight clinically relevant questions was posed, and consensus statements were developed. The evidence suggests that a minimum amount of KT is not needed to prevent attachment loss (AL) when optimal plaque control is present. However, if plaque control is suboptimal, a minimum of 2 mm of KT is needed. The standard procedure to predictably gain KT is the autogenous gingival graft. There is limited evidence for alternative treatment options. However, additional research may offer promising results in certain clinical scenarios. Before patient treatment, the clinician should evaluate etiology, including the role of inflammation and various types of trauma that contribute to AL. The best outcome procedure (autograft) and alternative options should be reviewed with the patient during appropriate informed consent. Proper assessment of the outcome should be included during supportive periodontal care.

High-resolution bottom-loss estimation using the ambient-noise vertical coherence function.

PubMed

Muzi, Lanfranco; Siderius, Martin; Quijano, Jorge E; Dosso, Stan E

2015-01-01

The seabed reflection loss (shortly "bottom loss") is an important quantity for predicting transmission loss in the ocean. A recent passive technique for estimating the bottom loss as a function of frequency and grazing angle exploits marine ambient noise (originating at the surface from breaking waves, wind, and rain) as an acoustic source. Conventional beamforming of the noise field at a vertical line array of hydrophones is a fundamental step in this technique, and the beamformer resolution in grazing angle affects the quality of the estimated bottom loss. Implementation of this technique with short arrays can be hindered by their inherently poor angular resolution. This paper presents a derivation of the bottom reflection coefficient from the ambient-noise spatial coherence function, and a technique based on this derivation for obtaining higher angular resolution bottom-loss estimates. The technique, which exploits the (approximate) spatial stationarity of the ambient-noise spatial coherence function, is demonstrated on both simulated and experimental data.

Discriminating quantum-optical beam-splitter channels with number-diagonal signal states: Applications to quantum reading and target detection

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

Nair, Ranjith

2011-09-15

We consider the problem of distinguishing, with minimum probability of error, two optical beam-splitter channels with unequal complex-valued reflectivities using general quantum probe states entangled over M signal and M' idler mode pairs of which the signal modes are bounced off the beam splitter while the idler modes are retained losslessly. We obtain a lower bound on the output state fidelity valid for any pure input state. We define number-diagonal signal (NDS) states to be input states whose density operator in the signal modes is diagonal in the multimode number basis. For such input states, we derive series formulas formore » the optimal error probability, the output state fidelity, and the Chernoff-type upper bounds on the error probability. For the special cases of quantum reading of a classical digital memory and target detection (for which the reflectivities are real valued), we show that for a given input signal photon probability distribution, the fidelity is minimized by the NDS states with that distribution and that for a given average total signal energy N{sub s}, the fidelity is minimized by any multimode Fock state with N{sub s} total signal photons. For reading of an ideal memory, it is shown that Fock state inputs minimize the Chernoff bound. For target detection under high-loss conditions, a no-go result showing the lack of appreciable quantum advantage over coherent state transmitters is derived. A comparison of the error probability performance for quantum reading of number state and two-mode squeezed vacuum state (or EPR state) transmitters relative to coherent state transmitters is presented for various values of the reflectances. While the nonclassical states in general perform better than the coherent state, the quantitative performance gains differ depending on the values of the reflectances. The experimental outlook for realizing nonclassical gains from number state transmitters with current technology at moderate to high values of the reflectances is argued to be good.« less

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

Moitra, Parikshit; Slovick, Brian A.; li, Wei

All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances canmore » be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.« less

Development of post-harvest protocol of okra for export marketing.

PubMed

Dhall, R K; Sharma, S R; Mahajan, B V C

2014-08-01

The study was carried out on the harvesting and handling methods of okra with the objective to maintain the best quality of pods from harvesting to end consumer especially for export marketing. For that purpose okra cv. 'Punjab-8' pods were harvested with minimum handling (least injuries to the pubescence on the ridges of pod) and normal handling (no safety taken to prevent injuries on pods). Pods were precooled at 15 ± 1ºC, 90-95% RH; jumble packed in the CFB boxes of 2.0 Kg capacity and than stored at 8 ± 1ºC, 90-95% RH. The quality parameters of okra namely texture, chlorophyll content, physiological loss in weight, rotting percentage and general appearance were studied. The pods harvested with minimum handling and field packaging can retain their green colour, crisp texture (maximum force to puncture pod = 500.2 g) with minimum rotting (3.0%) and physiological loss in weight (15.8%) and good appearance upto 13 days of cold storage whereas normal handled pods can be stored upto 5 days at 8 ± 1ºC, 90-95% RH and thereafter lost their general appearance on the 7th day of storage and were discarded. Therefore, in order to maintain high quality of okra from harvesting to the final destination (consumer), the okra pods should be harvested with minimum handling followed by field packaging in CFB boxes.

An economic analysis of selected strategies for dissolved-oxygen management; Chattahoochee River, Georgia

USGS Publications Warehouse

Schefter, John E.; Hirsch, Robert M.

1980-01-01

A method for evaluating the cost-effectiveness of alternative strategies for dissolved-oxygen (DO) management is demonstrated, using the Chattahoochee River, GA., as an example. The conceptual framework for the analysis is suggested by the economic theory of production. The minimum flow of the river and the percentage of the total waste inflow receiving nitrification are considered to be two variable inputs to be used in the production of given minimum concentration of DO in the river. Each of the inputs has a cost: the loss of dependable peak hydroelectric generating capacity at Buford Dam associated with flow augmentation and the cost associated with nitrification of wastes. The least-cost combination of minimum flow and waste treatment necessary to achieve a prescribed minimum DO concentration is identified. Results of the study indicate that, in some instances, the waste-assimilation capacity of the Chattahoochee River can be substituted for increased waste treatment; the associated savings in waste-treatment costs more than offset the benefits foregone because of the loss of peak generating capacity at Buford Dam. The sensitivity of the results to the estimates of the cost of replacing peak generating capacity is examined. It is also demonstrated that a flexible approach to the management of DO in the Chattahoochee River may be much more cost effective than a more rigid, institutional approach wherein constraints are placed on the flow of the river and(or) on waste-treatment practices. (USGS)

12 CFR 713.5 - What is the required minimum dollar amount of coverage?

Code of Federal Regulations, 2010 CFR

2010-01-01

... coverage required, but a federal credit union's board of directors should purchase additional or enhanced... its own internal risk assessment, its fraud trends and loss experience, and factors such as its cash...

Balancing Score Adjusted Targeted Minimum Loss-based Estimation

PubMed Central

Lendle, Samuel David; Fireman, Bruce; van der Laan, Mark J.

2015-01-01

Adjusting for a balancing score is sufficient for bias reduction when estimating causal effects including the average treatment effect and effect among the treated. Estimators that adjust for the propensity score in a nonparametric way, such as matching on an estimate of the propensity score, can be consistent when the estimated propensity score is not consistent for the true propensity score but converges to some other balancing score. We call this property the balancing score property, and discuss a class of estimators that have this property. We introduce a targeted minimum loss-based estimator (TMLE) for a treatment-specific mean with the balancing score property that is additionally locally efficient and doubly robust. We investigate the new estimator’s performance relative to other estimators, including another TMLE, a propensity score matching estimator, an inverse probability of treatment weighted estimator, and a regression-based estimator in simulation studies. PMID:26561539

Estimation of the transmissivity of thin leaky-confined aquifers from single-well pumping tests

NASA Astrophysics Data System (ADS)

Worthington, Paul F.

1981-01-01

Data from the quasi-equilibrium phases of a step-drawdown test are used to evaluate the coefficient of non-linear head losses subject to the assumption of a constant effective well radius. After applying a well-loss correction to the observed drawdowns of the first step, an approximation method is used to estimate a pseudo-transmissivity of the aquifer from a single value of time-variant drawdown. The pseudo-transmissivities computed for each of a sequence of values of time pass through a minimum when there is least manifestation of casing-storage and leakage effects, phenomena to which pumping-test data of this kind are particularly susceptible. This minimum pseudo-transmissivity, adjusted for partial penetration effects where appropriate, constitutes the best possible estimate of aquifer transmissivity. The ease of application of the overall procedure is illustrated by a practical example.

Microstructure, magnetic and microwave absorptive behavior of doped W-type hexaferrite nanoparticles prepared by co-precipitation method

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

Gordani, Gholam Reza, E-mail: gordani@gmail.com; Mohseni, Marzieh; Ghasemi, Ali

2016-04-15

Highlights: • High frequency properties of substituted W-type Sr-hexaferrite. • Saturation magnetization of samples is decreased with increasing of dopants content. • The ferrite sample covers about 6 GHz of bandwidth in K{sub u} band. • The optimum substituted samples can be used as a potential magnetic loss material. • Sample contain x = 0.4 of dopants have shown greater than 90% of reflection loss. - Abstract: Substituted W-type hexaferrite nanoparticles of SrZn{sub 2−x}Co{sub x/2}Ni{sub x/2}Fe{sub 16}O{sub 27} were synthesized by a chemical co-precipitation method. The X-ray diffraction results confirmed that W-type ferrite was identified as the main phase inmore » whole samples in the range of x = 0–0.4. According to magnetic hysteresis loops, with increasing of substituted cations, saturation of magnetization increased and coercivity decreased due to crystalline site occupation of Zn with Ni and Co cations. The microwave reflection loss analysis results in the K{sub u} band (12–18 GHz) show that the highest value of reflection loss of samples was −29.11 dB at frequency of 14.57 GHz with an absorption bandwidth of more than 6 GHz by choosing reflection loss value of −10 dB as a reference. The results indicate that, the sample with appropriate amount of substituted cations hold great promise for microwave device applications.« less

Enhanced microwave absorption property of epoxy nanocomposites based on PANI@Fe3O4@CNFs nanoparticles with three-phase heterostructure

NASA Astrophysics Data System (ADS)

Yang, Lingfeng; Cai, Haopeng; Zhang, Bin; Huo, Siqi; Chen, Xi

2018-02-01

Novel electromagnetic functionalized carbon nanofibers (CNFs) have been synthesized by coating with Fe3O4 magnetite nanoparticles and conducting polymers polyaniline (PANI) on CNFs through a layer by layer assembly. The Fe3O4@CNFs were first prepared by coating nano-Fe3O4 particles on CNFs via co-precipitation method; Then the PANI was coated on Fe3O4@CNFs using an in situ polymerization process to obtain PANI@Fe3O4@CNFs nanoparticles. The prepared PANI@Fe3O4@CNFs nanoparticles were dispersed in the epoxy matrix to fabricate microwave absorbing nanocomposites. Compared with the Fe3O4@CNFs/epoxy nanocomposites, the PANI@Fe3O4@CNFs/epoxy nanocomposites exhibit better microwave absorbing properties. The composite containing 15 wt% of PANI@Fe3O4@CNFs with the thickness of 2 mm showed a minimum reflection loss (RL) value of -23.7 dB with an effective absorption bandwidth which is about 3.7 GHz (11.9-15.6 GHz) in the frequency range of 1-18 GHz, indicating that it is an attractive candidate for efficient microwave absorber. A potential absorption mechanism was proposed for enhancement of the impedance-matching condition and electromagnetic wave-attenuation characteristic of materials. Specifically, the impedance-matching condition was improved by the combination of conductive polymers and magnetic nanoparticles with CNFs. The electromagnetic wave attenuation characteristic was enhanced by multiple reflections, due to the increased propagation paths.

Amenity or necessity? street standards as parking policy.

DOT National Transportation Integrated Search

2012-06-01

This paper explores the rationales underlying the use of minimum street width requirements to mandate street parking. A survey of 97 cities reveals that this mandate is not a technical necessity based on safety concerns or an amenity reflecting marke...

Investigation of energy deposited by femtosecond electron transfer in collisions using hydrated ion nanocalorimetry.

PubMed

Holm, Anne I S; Donald, William A; Hvelplund, Preben; Larsen, Mikkel K; Nielsen, Steen Brøndsted; Williams, Evan R

2008-10-30

Ion nanocalorimetry is used to investigate the internal energy deposited into M (2+)(H 2O) n , M = Mg ( n = 3-11) and Ca ( n = 3-33), upon 100 keV collisions with a Cs or Ne atom target gas. Dissociation occurs by loss of water molecules from the precursor (charge retention) or by capture of an electron to form a reduced precursor (charge reduction) that can dissociate either by loss of a H atom accompanied by water molecule loss or by exclusively loss of water molecules. Formation of bare CaOH (+) and Ca (+) by these two respective dissociation pathways occurs for clusters with n up to 33 and 17, respectively. From the threshold dissociation energies for the loss of water molecules from the reduced clusters, obtained from binding energies calculated using a discrete implementation of the Thomson liquid drop model and from quantum chemistry, estimates of the internal energy deposition can be obtained. These values can be used to establish a lower limit to the maximum and average energy deposition. Not taking into account effects of a kinetic shift, over 16 eV can be deposited into Ca (2+)(H 2O) 33, the minimum energy necessary to form bare CaOH (+) from the reduced precursor. The electron capture efficiency is at least a factor of 40 greater for collisions of Ca (2+)(H 2O) 9 with Cs than with Ne, reflecting the lower ionization energy of Cs (3.9 eV) compared to Ne (21.6 eV). The branching ratio of the two electron capture dissociation pathways differs significantly for these two target gases, but the distributions of water molecules lost from the reduced precursors are similar. These results suggest that the ionization energy of the target gas has a large effect on the electron capture efficiency, but relatively little effect on the internal energy deposited into the ion. However, the different branching ratios suggest that different electronic excited states may be accessed in the reduced precursor upon collisions with these two different target gases.

Variable selection for confounder control, flexible modeling and Collaborative Targeted Minimum Loss-based Estimation in causal inference

PubMed Central

Schnitzer, Mireille E.; Lok, Judith J.; Gruber, Susan

2015-01-01

This paper investigates the appropriateness of the integration of flexible propensity score modeling (nonparametric or machine learning approaches) in semiparametric models for the estimation of a causal quantity, such as the mean outcome under treatment. We begin with an overview of some of the issues involved in knowledge-based and statistical variable selection in causal inference and the potential pitfalls of automated selection based on the fit of the propensity score. Using a simple example, we directly show the consequences of adjusting for pure causes of the exposure when using inverse probability of treatment weighting (IPTW). Such variables are likely to be selected when using a naive approach to model selection for the propensity score. We describe how the method of Collaborative Targeted minimum loss-based estimation (C-TMLE; van der Laan and Gruber, 2010) capitalizes on the collaborative double robustness property of semiparametric efficient estimators to select covariates for the propensity score based on the error in the conditional outcome model. Finally, we compare several approaches to automated variable selection in low-and high-dimensional settings through a simulation study. From this simulation study, we conclude that using IPTW with flexible prediction for the propensity score can result in inferior estimation, while Targeted minimum loss-based estimation and C-TMLE may benefit from flexible prediction and remain robust to the presence of variables that are highly correlated with treatment. However, in our study, standard influence function-based methods for the variance underestimated the standard errors, resulting in poor coverage under certain data-generating scenarios. PMID:26226129

Variable Selection for Confounder Control, Flexible Modeling and Collaborative Targeted Minimum Loss-Based Estimation in Causal Inference.

PubMed

Schnitzer, Mireille E; Lok, Judith J; Gruber, Susan

2016-05-01

This paper investigates the appropriateness of the integration of flexible propensity score modeling (nonparametric or machine learning approaches) in semiparametric models for the estimation of a causal quantity, such as the mean outcome under treatment. We begin with an overview of some of the issues involved in knowledge-based and statistical variable selection in causal inference and the potential pitfalls of automated selection based on the fit of the propensity score. Using a simple example, we directly show the consequences of adjusting for pure causes of the exposure when using inverse probability of treatment weighting (IPTW). Such variables are likely to be selected when using a naive approach to model selection for the propensity score. We describe how the method of Collaborative Targeted minimum loss-based estimation (C-TMLE; van der Laan and Gruber, 2010 [27]) capitalizes on the collaborative double robustness property of semiparametric efficient estimators to select covariates for the propensity score based on the error in the conditional outcome model. Finally, we compare several approaches to automated variable selection in low- and high-dimensional settings through a simulation study. From this simulation study, we conclude that using IPTW with flexible prediction for the propensity score can result in inferior estimation, while Targeted minimum loss-based estimation and C-TMLE may benefit from flexible prediction and remain robust to the presence of variables that are highly correlated with treatment. However, in our study, standard influence function-based methods for the variance underestimated the standard errors, resulting in poor coverage under certain data-generating scenarios.

Measured Propagation Characteristics of Finite Ground Coplanar Waveguide on Silicon with a Thick Polyimide Interface Layer

NASA Technical Reports Server (NTRS)

Ponchak, George E.; Papapolymerou, John; Tentzeris, Emmanouil M.; Williams, W. O. (Technical Monitor)

2002-01-01

Measured propagation characteristics of Finite Ground Coplanar (FGC) waveguide on silicon substrates with resistivities spanning 3 orders of magnitude (0.1 to 15.5 Ohm cm) and a 20 micron thick polyimide interface layer is presented as a function of the FGC geometry. Results show that there is an optimum FGC geometry for minimum loss, and silicon with a resistivity of 0.1 Ohm cm has greater loss than substrates with higher and lower resistivity. Lastly, substrates with a resistivity of 10 Ohm cm or greater have acceptable loss.

Reduction of skylight reflection effects in the above-water measurement of diffuse marine reflectance.

PubMed

Fougnie, B; Frouin, R; Lecomte, P; Deschamps, P Y

1999-06-20

Reflected skylight in above-water measurements of diffuse marine reflectance can be reduced substantially by viewing the surface through an analyzer transmitting the vertically polarized component of incident radiance. For maximum reduction of effects, radiometric measurements should be made at a viewing zenith angle of approximately 45 degrees (near the Brewster angle) and a relative azimuth angle between solar and viewing directions greater than 90 degrees (backscattering), preferably 135 degrees. In this case the residual reflected skylight in the polarized signal exhibits minimum sensitivity to the sea state and can be corrected to within a few 10(-4) in reflectance units. For most oceanic waters the resulting relative error on the diffuse marine reflectance in the blue and green is less than 1%. Since the water body polarizes incident skylight, the measured polarized reflectance differs from the total reflectance. The difference, however, is small for the considered geometry. Measurements made at the Scripps Institution of Oceanography pier in La Jolla, Calif., with a specifically designed scanning polarization radiometer, confirm the theoretical findings and demonstrate the usefulness of polarization radiometry for measuring diffuse marine reflectance.

Monlithic nonplanar ring oscillator and method

NASA Technical Reports Server (NTRS)

Nilsson, Alan C. (Inventor); Byer, Robert L. (Inventor)

1991-01-01

A monolithic nonplanar ring oscillator having an optically isotropic solid-state laser body for propagating laser radiation about a nonplanar ring path internal to the laser body is disclosed. The monolithic laser body is configured to produce a 2N reflection nonplanar ring light path, where N is an integer greater than or equal to 2, comprising 2N-1 total internal reflections and one reflection at a coupler in a single round trip. Undirectional traveling wave oscillation of the laser is induced by the geometry of the nonplanar ring path together with the effect of an applied magnetic field and partial polarizer characteristics of the oblique reflection from the coupler. The 6-reflection nonplanar ring oscillator makes possible otpimal unidirectional oscillation (low loss for the oscillating direction of propagation and, simultaneously high loss for the nonoscillating direction of propagation) in monolithic NPROs using materials with index of refraction smaller than the square root of 3, for example, laser glass.

Student Difficulties in Analyzing Thin-Film Interference

NASA Astrophysics Data System (ADS)

Newburgh, Ronald; Goodale, Douglass

2009-04-01

A question we posed in a recent final examination has uncovered a fundamental difficulty for students in understanding destructive interference. The problem stated that glass of index n3 was coated with a thin film of a substance with index n2. The question then asked the student to calculate (a) the minimum coating thickness for maximum transmission into the glass and (b) the minimum thickness for minimum transmission into the glass, in both cases for a given wavelength. Questions from students during and after the examination showed that many had a problem in relating the interference to the transmission. We finally concluded that the source of confusion lay with an almost universally used figure in teaching interference in thin films, as well as the omission of the role of the electric field in reflection.

Glaucoma diagnostic ability of ganglion cell-inner plexiform layer thickness differs according to the location of visual field loss.

PubMed

Shin, Hye-Young; Park, Hae-Young Lopilly; Jung, Kyoung-In; Choi, Jin-A; Park, Chan Kee

2014-01-01

To determine whether the ganglion cell-inner plexiform layer (GCIPL) or circumpapillary retinal nerve fiber layer (cpRNFL) is better at distinguishing eyes with early glaucoma from normal eyes on the basis of the the initial location of the visual field (VF) damage. Retrospective, observational study. Eighty-four patients with early glaucoma and 43 normal subjects were enrolled. The patients with glaucoma were subdivided into 2 groups according to the location of VF damage: (1) an isolated parafoveal scotoma (PFS, N = 42) within 12 points of a central 10 degrees in 1 hemifield or (2) an isolated peripheral nasal step (PNS, N = 42) within the nasal periphery outside 10 degrees of fixation in 1 hemifield. All patients underwent macular and optic disc scanning using Cirrus high-definition optical coherence tomography (Carl Zeiss Meditec, Dublin, CA). The GCIPL and cpRNFL thicknesses were compared between groups. Areas under the receiver operating characteristic curves (AUCs) were calculated. Comparison of diagnostic ability using AUCs. The average and minimum GCIPL of the PFS group were significantly thinner than those of the PNS group, whereas there was no significant difference in the average retinal nerve fiber layer (RNFL) thickness between the 2 groups. The AUCs of the average (0.962) and minimum GCIPL (0.973) thicknesses did not differ from that of the average RNFL thickness (0.972) for discriminating glaucomatous changes between normal and all glaucoma eyes (P =0.566 and 0.974, respectively). In the PFS group, the AUCs of the average (0.988) and minimum GCIPL (0.999) thicknesses were greater than that of the average RNFL thickness (0.961, P =0.307 and 0.125, respectively). However, the AUCs of the average (0.936) and minimum GCIPL (0.947) thicknesses were lower than that of the average RNFL thickness (0.984) in the PNS group (P =0.032 and 0.069, respectively). The GCIPL parameters were more valuable than the cpRNFL parameters for detecting glaucoma in eyes with parafoveal VF loss, and the cpRNFL parameters were better than the GCIPL parameters for detecting glaucoma in eyes with peripheral VF loss. Clinicians should know that the diagnostic capability of macular GCIPL parameters depends largely on the location of the VF loss. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI

PubMed Central

Kang, Sinkyu; Hong, Suk Young

2016-01-01

A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km2. The lake area decreased by -9.3% at an annual rate of -53.7 km2 yr-1 during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability. PMID:27007233

A Tree-Ring Temperature Reconstruction from the Wrangell Mountains, Alaska (1593-1992): Evidence for Pronounced Regional Cooling During the Maunder Minimum

NASA Astrophysics Data System (ADS)

DArrigo, R.; Davi, N.; Jacoby, G.; Wiles, G.

2002-05-01

The Maunder Minimum interval (from the mid-1600s-early 1700s) is believed to have been one of the coldest periods of the past thousand years in the Northern Hemisphere. A maximum latewood density temperature reconstruction for the Wrangell Mountains, southern Alaska (1593-1992) provides information on regional temperature change during the Maunder Minimum and other periods of severe cold over the past four centuries. The Wrangell density record, which reflects warm season (July-September) temperatures, shows an overall cooling over the Maunder Minimum period with annual values reaching as low as -1.8oC below the long-term mean. Ring widths, which can integrate annual as well as summer conditions, also show pronounced cooling at the Wrangell site during this time, as do Arctic and hemispheric-scale temperature reconstructions based on tree rings and other proxy data. Maximum ages of glacial advance based on kill dates from overrun logs (which reflect cooler temperatures) coincide temporally with the cooling seen in the density and ring width records. In contrast, a recent modeling study indicates that during this period there was cold season (November-April) warming over much of Alaska, but cooling over other northern continental regions, as a result of decreased solar irradiance initiating low Arctic Oscillation index conditions. The influence of other forcings on Alaskan climate, the absence of ocean dynamical feedbacks in the model, and the different seasonality represented by the model and the trees may be some of the possible explanations for the different model and proxy results.

Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI.

PubMed

Kang, Sinkyu; Hong, Suk Young

2016-01-01

A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km(2). The lake area decreased by -9.3% at an annual rate of -53.7 km(2) yr(-1) during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability.

Steps towards understanding deep atmospheric heating in flares

NASA Technical Reports Server (NTRS)

Mauas, Pablo J. D.; Machado, Marcos E.

1986-01-01

Different aspects of the heating of the deep solar atmosphere during flares, including temperature minimum enhancements and white light emission, are discussed. The proper treatment of H(-) radiative losses is discussed, and compared with previous studies, as well as a quantitative analysis of the ionizing effect of nonthermal particles and ultraviolet radiation. It is concluded that temperature minimum heating may be a natural consequence of the global radiation transport in flares. The implications of these results are discussed within the context of homogeneous and inhomogeneous models of the solar atmosphere.

Development and Use of Fluorescent Probes for Detection, Enumeration and Identification of Naturally-Occurring Marine Viruses.

DTIC Science & Technology

1992-05-31

Samples were preserved (27) stemmed from a loss in titer that occurred when viruses in 1% glutaraldehyde before application to carbon-coated were added to...counting a minimum of 100 VLPs from 5 random fields at a magnification of 10,000 x. For most applications counting a minimum of 20 fields containing at...biological applications , Vol. 4, Hayat, M.A., editor, Van Nostrom Reinhold, N.Y., 1974, pp 79-104. 15. Proctor, L.M., and Fuhrman, J.A., Viral mortality

Development of Army High-Energy Fuel for Diesel/Turbine-Powered Surface Equipment. Phase II

DTIC Science & Technology

1981-12-01

preparation. The same extracting procedure used with methylene chloride was then used with pen- tans. A 3.0-percent loss in weight was noted, and a residue...minimum time to reach the target, and minimum weight . Since small missiles, such as the cruise, are volume-limited, it is imperative that the fuel contains...tetrahydrodicyclopentadiene (C1 0 R1 6 ) Molecular Weight 136.2 C:H Ratio 0.62 r Specific Gravity @ 15.60C (60*F) 0.94 Heating Value, Btu/gal. 142,000

Estimates of Crustal Transmission Losses Using MLM Array Processing.

DTIC Science & Technology

1982-07-01

boundary with a half space below, and with some form of reflection characteristic and/or loss mechanism. If acoustic energy , upon encountering the bottom...sea-sediment interface would probably be sufficient. However, sound energy does penetrate beneath the sea -2- floor and is both reflected and refracted...back to the water. In an active acoustical experiment, especially at longer ranges, a significant amount of tne received energy may come from waves

Large-Scale All-Dielectric Metamaterial Perfect Reflectors

DOE PAGES

Moitra, Parikshit; Slovick, Brian A.; li, Wei; ...

2015-05-08

All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances canmore » be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.« less

Electro-optic polymeric reflection modulator based on plasmonic metamaterial

NASA Astrophysics Data System (ADS)

Abbas, A.; Swillam, M.

2018-02-01

A novel low power design for polymeric Electro-Optic reflection modulator is proposed based on the Extraordinary Reflection of light from multilayer structure consisting of a plasmonic metasurface with a periodic structure of sub wavelength circular apertures in a gold film above a thin layer of EO polymer and above another thin gold layer. The interference of the different reflected beams from different layer construct the modulated beam, The applied input driving voltage change the polymer refractive index which in turn determine whether the interference is constructive or destructive, so both phase and intensity modulation could be achieved. The resonant wavelength is tuned to the standard telecommunication wavelength 1.55μm, at this wavelength the reflection is minimum, while the absorption is maximum due to plasmonic resonance (PR) and the coupling between the incident light and the plasmonic metasurface.

Student Involvement Can Be Stressful: Implications and Interventions.

ERIC Educational Resources Information Center

Floerchinger, Debra S.

1988-01-01

Involvement on campus varies from involvement in student organization leadership positions to paid paraprofessional positions that also reflect strong leadership expectations. A minimum amount of student development knowledge is essential for advisers for a successful functioning and ethical interaction with students. (MLW)

Status of holographic interferometry at University of Michigan

NASA Technical Reports Server (NTRS)

Vest, Charles

1987-01-01

Reflection holograms were taken of a jet of air injected traverse to a subsonic stream. The technique of reflection holograms allowed maximum viewing angle and minimum distance to the jet. Holographic interferometry is being used to measure the temperature distribution in a growing crystal. Computations of the temperatures are being made. A phase shift interferometer was used to study flows with very weak changes in refractive index, of the order of 1 shift. Tomographic techniques are being developed for strong refractive cases.

Experimental Investigation and Computer Modeling of Optical Switching in Distributed Bragg Reflector and Vertical Cavity Surface Emitting Laser Structures.

DTIC Science & Technology

1995-12-01

of a Molecular Beam Epitaxy (MBE) system prior to growing a Vertical Cavity Surface Emitting Laser ( VCSEL ). VCSEL bistability is discussed later in...addition, optical bistability 1 in the reflectivity of a DBR, as well as in the lasing power, wavelength, and beam divergence of a lasing VCSEL are...Spectral Reflectivity of AlGaAs/AlAs VCSEL Top DBR Mirror Cavity Bottom DBR Mirror Substrate Output Beam Resonance Pump Minimum Stop Band Figure 2. VCSEL

14 CFR Section 8 - General

Code of Federal Regulations, 2011 CFR

2011-01-01

... UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS Profit and Loss Classification Section 8 General (a) The profit and loss accounts are designed to reflect, through natural groupings, the... the dual subdivision of profit and loss elements in terms of both natural objectives and functional...

'The Loss of My Elderly Patient:' Interactive reflective writing to support medical students' rites of passage.

PubMed

Wald, Hedy S; Reis, Shmuel P; Monroe, Alicia D; Borkan, Jeffrey M

2010-01-01

The fostering of reflective capacity within medical education helps develop critical thinking and clinical reasoning skills and enhances professionalism. Use of reflective narratives to augment reflective practice instruction is well documented. At Warren Alpert Medical School of Brown University (Alpert Med), a narrative medicine curriculum innovation of students' reflective writing (field notes) with individualized feedback from an interdisciplinary faculty team (in pre-clinical years) has been implemented in a Doctoring course to cultivate reflective capacity, empathy, and humanism. Interactive reflective writing (student writer/faculty feedback provider dyad), we propose, can additionally support students with rites of passage at critical educational junctures. At Alpert Med, we have devised a tool to guide faculty in crafting quality feedback, i.e. the Brown Educational Guide to Analysis of Narrative (BEGAN) which includes identifying students' salient quotes, utilizing reflection-inviting questions and close reading, highlighting derived lessons/key concepts, extracting clinical patterns, and providing concrete recommendations as relevant. We provide an example of a student's narrative describing an emotionally powerful and meaningful event - the loss of his first patient - and faculty responses using BEGAN. The provision of quality feedback to students' reflective writing - supported by BEGAN - can facilitate the transformation of student to professional through reflection within medical education.

Setting a national minimum standard for health benefits: how do state benefit mandates compare with benefits in large-group plans?

PubMed

Frey, Allison; Mika, Stephanie; Nuzum, Rachel; Schoen, Cathy

2009-06-01

Many proposed health insurance reforms would establish a federal minimum benefit standard--a baseline set of benefits to ensure that people have adequate coverage and financial protection when they purchase insurance. Currently, benefit mandates are set at the state level; these vary greatly across states and generally target specific areas rather than set an overall standard for what qualifies as health insurance. This issue brief considers what a broad federal minimum standard might look like by comparing existing state benefit mandates with the services and providers covered under the Federal Employees Health Benefits Program (FEHBP) Blue Cross and Blue Shield standard benefit package, an example of minimum creditable coverage that reflects current standard practice among employer-sponsored health plans. With few exceptions, benefits in the FEHBP standard option either meet or exceed those that state mandates require-indicating that a broad-based national benefit standard would include most existing state benefit mandates.

CORRELATION OF CLINICAL AND STRUCTURAL PROGRESSION WITH VISUAL ACUITY LOSS IN MACULAR TELANGIECTASIA TYPE 2: MacTel Project Report No. 6-The MacTel Research Group.

PubMed

Peto, Tunde; Heeren, Tjebo F C; Clemons, Traci E; Sallo, Ferenc B; Leung, Irene; Chew, Emily Y; Bird, Alan C

2018-01-01

To evaluate progression of macular telangiectasia Type 2 lesions and their correlation with visual acuity. An international multicenter prospective study with annual examinations including best-corrected visual acuity (BCVA), fundus photography, fluorescein angiography, and optical coherence tomography images graded centrally. Mixed models were used to estimate progression rates, and a generalized linear model to compute the relative risk of BCVA loss, loss of ellipsoid zone (EZ) reflectivity, development of pigment plaques, or neovascularization. One thousand and fourteen eyes of 507 participants were followed for 4.2 ± 1.6 years. Best-corrected visual acuity decreased 1.07 ± 0.05 letters (mean ± SE) per year. Of all eyes, 15% lost ≥15 letters after 5 years. Of the eyes without EZ loss, 76% developed a noncentral loss. Of the eyes with noncentral loss, 45% progressed to central EZ loss. The rate of BCVA loss in eyes with noncentral EZ loss at baseline was similar to eyes without EZ loss. The rate of BCVA loss was significantly higher in eyes with central EZ loss at baseline (-1.40 ± 0.14 letters, P < 0.001). Ellipsoid zone loss is frequently found in macular telangiectasia Type 2 and is an important structural component reflecting visual function. Its presence in the fovea significantly correlates with worse visual prognosis.

Imaging for Appendicitis: Should Radiation-induced Cancer Risks Affect Modality Selection?

PubMed Central

Kiatpongsan, Sorapop; Meng, Lesley; Eisenberg, Jonathan D.; Herring, Maurice; Avery, Laura L.; Kong, Chung Yin

2014-01-01

Purpose To compare life expectancy (LE) losses attributable to three imaging strategies for appendicitis in adults—computed tomography (CT), ultrasonography (US) followed by CT for negative or indeterminate US results, and magnetic resonance (MR) imaging—by using a decision-analytic model. Materials and Methods In this model, for each imaging strategy, LE losses for 20-, 40-, and 65-year-old men and women were computed as a function of five key variables: baseline cohort LE, test performance, surgical mortality, risk of death from delayed diagnosis (missed appendicitis), and LE loss attributable to radiation-induced cancer death. Appendicitis prevalence, test performance, mortality rates from surgery and missed appendicitis, and radiation doses from CT were elicited from the published literature and institutional data. LE loss attributable to radiation exposure was projected by using a separate organ-specific model that accounted for anatomic coverage during a typical abdominopelvic CT examination. One- and two-way sensitivity analyses were performed to evaluate effects of model input variability on results. Results Outcomes across imaging strategies differed minimally—for example, for 20-year-old men, corresponding LE losses were 5.8 days (MR imaging), 6.8 days (combined US and CT), and 8.2 days (CT). This order was sensitive to differences in test performance but was insensitive to variation in radiation-induced cancer deaths. For example, in the same cohort, MR imaging sensitivity had to be 91% at minimum (if specificity were 100%), and MR imaging specificity had to be 62% at minimum (if sensitivity were 100%) to incur the least LE loss. Conversely, LE loss attributable to radiation exposure would need to decrease by 74-fold for combined US and CT, instead of MR imaging, to incur the least LE loss. Conclusion The specific imaging strategy used to diagnose appendicitis minimally affects outcomes. Paradigm shifts to MR imaging owing to concerns over radiation should be considered only if MR imaging test performance is very high. © RSNA, 2014 PMID:24988435

Wear resistance of machine tools' bionic linear rolling guides by laser cladding

NASA Astrophysics Data System (ADS)

Wang, Yiqiang; Liu, Botao; Guo, Zhengcai

2017-06-01

In order to improve the rolling wear resistance (RWR) of linear rolling guides (LRG) as well as prolong the life of machine tools, various shape samples with different units spaces ranged from 1 to 5 mm are designed through the observation of animals in the desert and manufactured by laser cladding. Wear resistance tests reproducing closely the real operational condition are conducted by using a homemade linear reciprocating wear test machine, and wear resistance is evaluated by means of weight loss measurement. Results indicate that the samples with bionic units have better RWR than the untreated one, of which the reticulate treated sample with unit space 3 mm present the best RWR. More specifically, among the punctuate treated samples, the mass loss increases with the increase of unit space; among the striate treated samples, the mass loss changes slightly with the increase of unit space, attaining a minimum at the unit space of 4 mm; among the reticulate treated samples, with the increase of unit space, the mass loss initially decreases, but turns to increase after reaching a minimum at the unit space of 3 mm. Additionally, the samples with striate shape perform better wear resistance than the other shape groups on the whole. From the ratio value of laser treated area to contacted area perspective, that the samples with ratio value between 0.15 and 0.3 possess better wear resistance is concluded.

Quantification of root caries using optical coherence tomography and microradiography: a correlational study.

PubMed

Amaechi, Bennett T; Podoleanu, Adrian Gh; Komarov, Gleb; Higham, Susan M; Jackson, David A

2004-01-01

The use of transverse microradiography (TMR) to quantify the amount of mineral lost during demineralization of tooth tissue has long been established. In the present study, the use of an en-face Optical Coherence Tomography (OCT) technology to detect and quantitatively monitor the mineral changes in root caries was investigated and correlated with TMR. We used an OCT system, developed initially for retina imaging, and which can collect A-scans, B-scans (longitudinal images) and C-scans (en-face images) to quantitatively assess the development of root caries. The power to the sample was 250 microW, wavelength lambda = 850 nm and the optical source linewidth was 16 microm. Both the transversal and longitudinal images showed the caries lesion as volumes of reduced reflectivity. Quantitative analysis using the A-scan (reflectivity versus depth curve) showed that the tissue reflectivity decreased with increasing demineralization time. A linear correlation (r = 0.957) was observed between the mineral loss measured by TMR and the percentage reflectivity loss in demineralized tissue measured by OCT. We concluded that OCT could be used to detect incipient root caries, and that the reflectivity loss in root tissue during demineralization, measured by OCT, could be related to the amount of mineral lost during the demineralization.

Electromagnetic properties of absorber fabric coated with BaFe12O19/MWCNTs/PANi nanocomposite in X and Ku bands frequency

NASA Astrophysics Data System (ADS)

Afzali, Arezoo; Mottaghitalab, Vahid; Seyyed Afghahi, Seyyed Salman; Jafarian, Mojtaba; Atassi, Yomen

2017-11-01

Current investigation focuses on the electromagnetic properties of nonwoven fabric coated with BaFe12O19 (BHF) /MWCNTs/PANi nanocomposite in X and Ku bands. The BHF/MWCNTs and BHF/MWCNTs/PANi nanocomposites are prepared using the sol gel and in-situ polymerization methods respectively. The absorbent fabric was prepared based on applying a 40 wt% of BHF/MWCNTs/PANi nanocomposite in silicon resin on nonwoven fabric via roller coating technique The X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and vector network analysis (VNA) are used to peruse microstructural, magnetic and electromagnetic features of the composite and absorber fabric respectively. The microscopic images of the fabric coated with magnetic nanocomposite shows a homogenous layer of nanoparticles on the fabric surface. The maximum reflection loss of binary nano-composite BHF/MWCNTs was measured about -28.50 dB at 11.72 GHz with 1.7 GHz bandwidth (RL < -10 dB) in X band. Moreover in Ku band, the maximum reflection loss is -29.66 dB at 15.78 GHz with 3.2 GHz bandwidths. Also the ternary nanocomposite BHF/MWCNTs/PANi exhibits a broad band absorber over a wide range of X band with a maximum reflection loss of -36.2 dB at 10.2 GHz with 1.5 GHz bandwidth and in the Ku band has arrived a maximum reflection loss of -37.65 dB at 12.84 GHz with 2.43 GHz bandwidth. This result reflects the synergistic effect of the different components with different loss mechanisms. As it is observed due to the presence of PANi in the structure of nanocomposite, the amount of absorption has increased extraordinarily. The absorber fabric exhibits a maximum reflection loss of -24.2 dB at 11.6 GHz with 4 GHz bandwidth in X band. However, in Ku band, the absorber fabric has had the maximum absorption in 16.88 GHz that is about -24.34 dB with 6 GHz bandwidth. Therefore, results indicate that the fabric samples coated represents appreciable maximum absorption value of more than 99% in X and Ku bands which can be attributed to presence of carbon and polyaniline structure in composite material.

Provider communication behaviors that predict motivation to change in black adolescents with obesity.

PubMed

Carcone, April Idalski; Naar-King, Sylvie; Brogan, Kathryn E; Albrecht, Terrance; Barton, Ellen; Foster, Tanina; Martin, Tim; Marshall, Sharon

2013-10-01

The goal of this research was to identify communication behaviors used by weight loss counselors that mostly strongly predicted black adolescents' motivational statements. Three types of motivational statements were of interest: change talk (CT; statements describing their own desires, abilities, reasons, and need for adhering to weight loss recommendations), commitment language (CML; statements about their intentions or plans for adhering), and counterchange talk (CCT; amotivational statements against change and commitment). Thirty-seven black adolescents with obesity received a single motivational interviewing session targeting weight-related behaviors. The video-recorded transcribed sessions were coded using the Minority Youth Sequential Coding for Observing Process Exchanges generating a sequential chain of communication. Data were then subjected to sequential analysis to determine causal relationships between counselor and adolescent communication. Asking open-ended questions to elicit adolescent CT and emphasizing adolescents' autonomy most often led to CT. Open-ended questions to elicit CML, reflecting adolescent CML, and emphasizing autonomy most often led to CML. In contrast, open-ended questions to elicit CCT, reflecting CCT, reflecting ambivalence, and neutral open-ended questions about the target behavior led to CCT. This study provides clinicians with insight into the most effective way to communicate with black adolescents with obesity about weight loss. Specifically, reflective statements and open questions focusing on their own desires, abilities, reasons, need, and commitment to weight loss recommendations are more likely to increase motivational statements, whereas other types of reflections and questions may be counterproductive. Finally, because adolescents have a strong need for autonomous decision making, emphasizing their autonomy may be particularly effective in evoking motivational statements.

A new method of optimal capacitor switching based on minimum spanning tree theory in distribution systems

NASA Astrophysics Data System (ADS)

Li, H. W.; Pan, Z. Y.; Ren, Y. B.; Wang, J.; Gan, Y. L.; Zheng, Z. Z.; Wang, W.

2018-03-01

According to the radial operation characteristics in distribution systems, this paper proposes a new method based on minimum spanning trees method for optimal capacitor switching. Firstly, taking the minimal active power loss as objective function and not considering the capacity constraints of capacitors and source, this paper uses Prim algorithm among minimum spanning trees algorithms to get the power supply ranges of capacitors and source. Then with the capacity constraints of capacitors considered, capacitors are ranked by the method of breadth-first search. In term of the order from high to low of capacitor ranking, capacitor compensation capacity based on their power supply range is calculated. Finally, IEEE 69 bus system is adopted to test the accuracy and practicality of the proposed algorithm.

Enhancement of slope efficiency and output power in GaN-based vertical-cavity surface-emitting lasers with a SiO2-buried lateral index guide

NASA Astrophysics Data System (ADS)

Kuramoto, Masaru; Kobayashi, Seiichiro; Akagi, Takanobu; Tazawa, Komei; Tanaka, Kazufumi; Saito, Tatsuma; Takeuchi, Tetsuya

2018-03-01

We have achieved a high output power of 6 mW from a 441 nm GaN-based vertical-cavity surface-emitting laser (VCSEL) under continuous wave (CW) operation, by reducing both the internal loss and the reflectivity of the front cavity mirror. A preliminary analysis of the internal loss revealed an enormously high transverse radiation loss in a conventional GaN-based VCSEL without lateral optical confinement (LOC). Introducing an LOC structure enhanced the slope efficiency by a factor of 4.7, with a further improvement to a factor of 6.7 upon reducing the front mirror reflectivity. The result was a slope efficiency of 0.87 W/A and an external differential quantum efficiency of 32% under pulsed operation. A flip-chip-bonded VCSEL also exhibited a high slope efficiency of 0.64 W/A and an external differential quantum efficiency of 23% for the front-side output under CW operation. The reflectivity of the cavity mirror was adjusted by varying the number of AlInN/GaN distributed Bragg reflector pairs from 46 to 42, corresponding to reflectivity values from 99.8% to 99.5%. These results demonstrate that a combination of internal loss reduction and cavity mirror control is a very effective way of obtaining a high output GaN-based VCSEL.

Mercury's hollows: Constraints on formation and composition from analysis of geological setting and spectral reflectance

NASA Astrophysics Data System (ADS)

Blewett, David T.; Vaughan, William M.; Xiao, Zhiyong; Chabot, Nancy L.; Denevi, Brett W.; Ernst, Carolyn M.; Helbert, JöRn; D'Amore, Mario; Maturilli, Alessandro; Head, James W.; Solomon, Sean C.

2013-05-01

unique to Mercury, hollows are shallow, flat-floored irregular depressions notable for their relatively high reflectance and characteristic color. Here we document the range of geological settings in which hollows occur. Most are associated with impact structures (simple bowl-shaped craters to multiring basins, and ranging from Kuiperian to Calorian in age). Hollows are found in the low-reflectance material global color unit and in low-reflectance blue plains, but they appear to be absent from high-reflectance red plains. Hollows may occur preferentially on equator- or hot-pole-facing slopes, implying that their formation is linked to solar heating. Evidence suggests that hollows form because of loss of volatile material. We describe hypotheses for the origin of the volatiles and for how such loss proceeds. Intense space weathering and solar heating are likely contributors to the loss of volatiles; contact heating by melts could promote the formation of hollows in some locations. Lunar Ina-type depressions differ from hollows on Mercury in a number of characteristics, so it is unclear if they represent a good analog. We also use MESSENGER multispectral images to characterize a variety of surfaces on Mercury, including hollows, within a framework defined by laboratory spectra for analog minerals and lunar samples. Data from MESSENGER's X-Ray Spectrometer indicate that the planet's surface contains up to 4% sulfur. We conclude that nanophase or microphase sulfide minerals could contribute to the low reflectance of the low-reflectance material relative to average surface material. Hollows may owe their relatively high reflectance to destruction of the darkening agent (sulfides), the presence of alteration minerals, and/or physical differences in particle size, texture, or scattering behavior.

Folded Fabry-Perot quasi-optical ring resonator diplexer Theory and experiment

NASA Technical Reports Server (NTRS)

Pickett, H. M.; Chiou, A. E. T.

1983-01-01

Performance of folded Fabry-Perot quasi-optical ring resonator diplexers with different geometries of reflecting surfaces is investigated both theoretically and experimentally. Design of optimum surface geometry for minimum diffraction, together with the figure of merit indicating improvement in performance, are given.

Change in mean temperature as a predictor of extreme temperature change in the Asia-Pacific region

NASA Astrophysics Data System (ADS)

Griffiths, G. M.; Chambers, L. E.; Haylock, M. R.; Manton, M. J.; Nicholls, N.; Baek, H.-J.; Choi, Y.; della-Marta, P. M.; Gosai, A.; Iga, N.; Lata, R.; Laurent, V.; Maitrepierre, L.; Nakamigawa, H.; Ouprasitwong, N.; Solofa, D.; Tahani, L.; Thuy, D. T.; Tibig, L.; Trewin, B.; Vediapan, K.; Zhai, P.

2005-08-01

Trends (1961-2003) in daily maximum and minimum temperatures, extremes and variance were found to be spatially coherent across the Asia-Pacific region. The majority of stations exhibited significant trends: increases in mean maximum and mean minimum temperature, decreases in cold nights and cool days, and increases in warm nights. No station showed a significant increase in cold days or cold nights, but a few sites showed significant decreases in hot days and warm nights. Significant decreases were observed in both maximum and minimum temperature standard deviation in China, Korea and some stations in Japan (probably reflecting urbanization effects), but also for some Thailand and coastal Australian sites. The South Pacific convergence zone (SPCZ) region between Fiji and the Solomon Islands showed a significant increase in maximum temperature variability.Correlations between mean temperature and the frequency of extreme temperatures were strongest in the tropical Pacific Ocean from French Polynesia to Papua New Guinea, Malaysia, the Philippines, Thailand and southern Japan. Correlations were weaker at continental or higher latitude locations, which may partly reflect urbanization.For non-urban stations, the dominant distribution change for both maximum and minimum temperature involved a change in the mean, impacting on one or both extremes, with no change in standard deviation. This occurred from French Polynesia to Papua New Guinea (except for maximum temperature changes near the SPCZ), in Malaysia, the Philippines, and several outlying Japanese islands. For urbanized stations the dominant change was a change in the mean and variance, impacting on one or both extremes. This result was particularly evident for minimum temperature.The results presented here, for non-urban tropical and maritime locations in the Asia-Pacific region, support the hypothesis that changes in mean temperature may be used to predict changes in extreme temperatures. At urbanized or higher latitude locations, changes in variance should be incorporated.

Mobility based multicast routing in wireless mesh networks

NASA Astrophysics Data System (ADS)

Jain, Sanjeev; Tripathi, Vijay S.; Tiwari, Sudarshan

2013-01-01

There exist two fundamental approaches to multicast routing namely minimum cost trees and shortest path trees. The (MCT's) minimum cost tree is one which connects receiver and sources by providing a minimum number of transmissions (MNTs) the MNTs approach is generally used for energy constraint sensor and mobile ad hoc networks. In this paper we have considered node mobility and try to find out simulation based comparison of the (SPT's) shortest path tree, (MST's) minimum steiner trees and minimum number of transmission trees in wireless mesh networks by using the performance metrics like as an end to end delay, average jitter, throughput and packet delivery ratio, average unicast packet delivery ratio, etc. We have also evaluated multicast performance in the small and large wireless mesh networks. In case of multicast performance in the small networks we have found that when the traffic load is moderate or high the SPTs outperform the MSTs and MNTs in all cases. The SPTs have lowest end to end delay and average jitter in almost all cases. In case of multicast performance in the large network we have seen that the MSTs provide minimum total edge cost and minimum number of transmissions. We have also found that the one drawback of SPTs, when the group size is large and rate of multicast sending is high SPTs causes more packet losses to other flows as MCTs.

Area of vegetation loss: a new index of campsite impact

Treesearch

David N. Cole

1989-01-01

Expressions of the amount of vegetation lost on campsites should reflect both the proportion of vegetation lost and the area1 extent of vegetation loss. A new index-area of vegetation loss-incorporates these two elements by multiplying campsite area by absolute vegetation loss. Guidelines on how to take the measurements needed to calculate this index are provided...

Age, circadian rhythms, and sleep loss in flight crews

NASA Technical Reports Server (NTRS)

Gander, Philippa H.; Nguyen, DE; Rosekind, Mark R.; Connell, Linda J.

1993-01-01

Age-related changes in trip-induced sleep loss, personality, and the preduty temperature rhythm were analyzed in crews from various flight operations. Eveningness decreased with age. The minimum of the baseline temperature rhythm occurred earlier with age. The amplitude of the baseline temperature rhythm declined with age. Average daily percentage sleep loss during trips increased with age. Among crewmembers flying longhaul flight operations, subjects aged 50-60 averaged 3.5 times more sleep loss per day than subjects aged 20-30. These studies support previous findings that evening types and subjects with later peaking temperature rhythms adapt better to shift work and time zone changes. Age and circadian type may be important considerations for duty schedules and fatigue countermeasures.

At a Loss: Scared and Excited

ERIC Educational Resources Information Center

Silin, Jonathan

2013-01-01

Drawing on the author's struggle to come to terms with multiple personal losses, his observations of young children in early childhood classrooms, and work with novice teachers, this essay points to the generative possibilities embedded in moments of disorienting loss. Constrained by traditional templates of mourning that did not reflect the lived…

26 CFR 1.704-3 - Contributed property.

Code of Federal Regulations, 2011 CFR

2011-04-01

... partners with respect to precontribution gain or loss. Under section 704(c), a partnership must allocate income, gain, loss, and deduction with respect to property contributed by a partner to the partnership so...) to reflect built-in gain (or loss), or a method under which the partnership creates tax allocations...

26 CFR 1.704-3 - Contributed property.

Code of Federal Regulations, 2013 CFR

2013-04-01

... partners with respect to precontribution gain or loss. Under section 704(c), a partnership must allocate income, gain, loss, and deduction with respect to property contributed by a partner to the partnership so...) to reflect built-in gain (or loss), or a method under which the partnership creates tax allocations...

26 CFR 1.704-3 - Contributed property.

Code of Federal Regulations, 2012 CFR

2012-04-01

... partners with respect to precontribution gain or loss. Under section 704(c), a partnership must allocate income, gain, loss, and deduction with respect to property contributed by a partner to the partnership so...) to reflect built-in gain (or loss), or a method under which the partnership creates tax allocations...

26 CFR 1.704-3 - Contributed property.

Code of Federal Regulations, 2014 CFR

2014-04-01

... partners with respect to precontribution gain or loss. Under section 704(c), a partnership must allocate income, gain, loss, and deduction with respect to property contributed by a partner to the partnership so...) to reflect built-in gain (or loss), or a method under which the partnership creates tax allocations...

On the Minimum Induced Drag of Wings

NASA Technical Reports Server (NTRS)

Bowers, Albion H.

2010-01-01

Of all the types of drag, induced drag is associated with the creation and generation of lift over wings. Induced drag is directly driven by the span load that the aircraft is flying at. The tools by which to calculate and predict induced drag we use were created by Ludwig Prandtl in 1903. Within a decade after Prandtl created a tool for calculating induced drag, Prandtl and his students had optimized the problem to solve the minimum induced drag for a wing of a given span, formalized and written about in 1920. This solution is quoted in textbooks extensively today. Prandtl did not stop with this first solution, and came to a dramatically different solution in 1932. Subsequent development of this 1932 solution solves several aeronautics design difficulties simultaneously, including maximum performance, minimum structure, minimum drag loss due to control input, and solution to adverse yaw without a vertical tail. This presentation lists that solution by Prandtl, and the refinements by Horten, Jones, Kline, Viswanathan, and Whitcomb

On the Minimum Induced Drag of Wings -or- Thinking Outside the Box

NASA Technical Reports Server (NTRS)

Bowers, Albion H.

2011-01-01

Of all the types of drag, induced drag is associated with the creation and generation of lift over wings. Induced drag is directly driven by the span load that the aircraft is flying at. The tools by which to calculate and predict induced drag we use were created by Ludwig Prandtl in 1903. Within a decade after Prandtl created a tool for calculating induced drag, Prandtl and his students had optimized the problem to solve the minimum induced drag for a wing of a given span, formalized and written about in 1920. This solution is quoted in textbooks extensively today. Prandtl did not stop with this first solution, and came to a dramatically different solution in 1932. Subsequent development of this 1932 solution solves several aeronautics design difficulties simultaneously, including maximum performance, minimum structure, minimum drag loss due to control input, and solution to adverse yaw without a vertical tail. This presentation lists that solution by Prandtl, and the refinements by Horten, Jones, Kline, Viswanathan, and Whitcomb.

On the Minimum Induced Drag of Wings

NASA Technical Reports Server (NTRS)

Bowers, Albion H.

2011-01-01

Of all the types of drag, induced drag is associated with the creation and generation of lift over wings. Induced drag is directly driven by the span load that the aircraft is flying at. The tools by which to calculate and predict induced drag we use were created by Ludwig Prandtl in 1903. Within a decade after Prandtl created a tool for calculating induced drag, Prandtl and his students had optimized the problem to solve the minimum induced drag for a wing of a given span, formalized and written about in 1920. This solution is quoted in textbooks extensively today. Prandtl did not stop with this first solution, and came to a dramatically different solution in 1932. Subsequent development of this 1932 solution solves several aeronautics design difficulties simultaneously, including maximum performance, minimum structure, minimum drag loss due to control input, and solution to adverse yaw without a vertical tail. This presentation lists that solution by Prandtl, and the refinements by Horten, Jones, Kline, Viswanathan, and Whitcomb.

Analysis of Global Urban Temperature Trends and Urbanization Impacts

NASA Astrophysics Data System (ADS)

Lee, K. I.; Ryu, J.; Jeon, S. W.

2018-04-01

Due to urbanization, urban areas are shrinking green spaces and increasing concrete, asphalt pavement. So urban climates are different from non-urban areas. In addition, long-term macroscopic studies of urban climate change are becoming more important as global urbanization affects global warming. To do this, it is necessary to analyze the effect of urbanization on the temporal change in urban temperature with the same temperature data and standards for urban areas around the world. In this study, time series analysis was performed with the maximum, minimum, mean and standard values of surface temperature during the from 1980 to 2010 and analyzed the effect of urbanization through linear regression analysis with variables (population, night light, NDVI, urban area). As a result, the minimum value of the surface temperature of the urban area reflects an increase by a rate of 0.28K decade-1 over the past 31 years, the maximum value reflects an increase by a rate of 0.372K decade-1, the mean value reflects an increase by a rate of 0.208 decade-1, and the standard deviation reflects a decrease by rate of 0.023K decade-1. And the change of surface temperature in urban areas is affected by urbanization related to land cover such as decrease of greenery and increase of pavement area, but socioeconomic variables are less influential than NDVI in this study. This study are expected to provide an approach to future research and policy-planning for urban temperature change and urbanization impacts.

33 CFR 203.31 - Authority.

Code of Federal Regulations, 2010 CFR

2010-07-01

... debris blockages of critical water supply intakes, sewer outfalls, etc.; clearance of the minimum amounts... intended to prevent imminent loss of life or significant public property, or to protect against significant... following: technical advice and assistance; lending of flood fight supplies, e.g., sandbags, lumber...

Use of complex frequency plane to design broadband and sub-wavelength absorbers.

PubMed

Romero-García, V; Theocharis, G; Richoux, O; Pagneux, V

2016-06-01

The reflection of sound of frequency below 1 kHz, by a rigid-backed structure that contains sub-wavelength resonators is studied in this work. In particular, only single mode reflected waves are considered, an approximation which is accurate in this low frequency regime. A method of analysis of absorption that uses the structure of the reflection coefficient in the complex frequency plane is proposed. In the absence of losses, the reflection coefficient supports pairs of poles and zeros that are complex conjugate and which have imaginary parts linked to the energy leakage by radiation. When losses are introduced and balanced to the leakage, the critical coupling condition is satisfied and total absorption is obtained. Examples of a slot resonator and of multiple Helmholtz resonators are analyzed to obtain both narrow and broadband total absorption.

A MEMS disk resonator-based band pass filter electrical equivalent circuit simulation

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

Sundaram, G. M.; Angira, Mahesh; Gupta, Navneet

In this paper, coupled beam bandpass Disk filter is designed for 1 MHz bandwidth. Filter electrical equivalent circuit simulation is performed using circuit simulators. Important filter parameters such as insertion loss, shape factor and Q factor aresetimated using coventorware simulation. Disk resonator based radial contour mode filter provides 1.5 MHz bandwidth and unloaded quality factor of resonator and filter as 233480, 21797 respectively. From the simulation result it’s found that insertion loss minimum is 151.49 dB, insertion loss maximum is 213.94 dB, and 40 dB shape factor is 4.17.

2-µm wavelength-range low-loss inhibited-coupling hollow-core PCF

NASA Astrophysics Data System (ADS)

Maurel, M.; Chafer, M.; Delahaye, F.; Amrani, F.; Debord, B.; Gerome, F.; Benabid, F.

2018-02-01

We report on the design and fabrication of inhibited-coupling guiding hollow-core photonic crystal fiber with a transmission band optimized for low loss guidance around 2 μm. Two fibers design based on a Kagome-lattice cladding have been studied to demonstrate a minimum loss figure of 25 dB/km at 2 μm associated to an ultra-broad transmission band spanning from the visible to our detection limit of 3.4 μm. Such fibers could be an excellent tool to deliver and compress ultra-short pulse laser systems, especially for the emerging 2-3 μm spectral region.

Multi-layer coating of SiO2 nanoparticles to enhance light absorption by Si solar cells

NASA Astrophysics Data System (ADS)

Nam, Yoon-Ho; Um, Han-Don; Park, Kwang-Tae; Shin, Sun-Mi; Baek, Jong-Wook; Park, Min-Joon; Jung, Jin-Young; Zhou, Keya; Jee, Sang-Won; Guo, Zhongyi; Lee, Jung-Ho

2012-06-01

We found that multi-layer coating of a Si substrate with SiO2 dielectric nanoparticles (NPs) was an effective method to suppress light reflection by silicon solar cells. To suppress light reflection, two conditions are required for the coating: 1) The difference of refractive indexes between air and Si should be alleviated, and 2) the quarter-wavelength antireflection condition should be satisfied while avoiding intrinsic absorption loss. Light reflection was reduced due to destructive interference at certain wavelengths that depended on the layer thickness. For the same thickness dielectric layer, smaller NPs enhanced antireflectance more than larger NPs due to a decrease in scattering loss by the smaller NPs.

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Polarisation splitting of laser beams by large angles with minimal reflection losses

NASA Astrophysics Data System (ADS)

Davydov, B. L.

2006-05-01

New crystal anisotropic prisms for splitting orthogonally polarised components of laser radiation by large angles with minimal reflection losses caused by the Brewster refraction and total internal reflection of polarised waves from the crystal—air interface are considered and the method for their calculation is described. It is shown that, by assembling glue-free combinations of two or three prisms, thermally stable beamsplitters can be fabricated, which are free from the beam astigmatism and the wave dispersion of the output angles of the beams. The parameters and properties of new beamsplitters are presented in a convenient form in figures and tables.

Axial propulsion with flapping and rotating wings, a comparison of potential efficiency.

PubMed

Kroninger, Christopher M

2018-04-18

Interest in biological locomotion and what advantages the principles governing it might offer in the design of manmade vehicles prompts one to consider the power requirements of flapping relative to rotary propulsion. The amount of work performed on the fluid surrounding a thrusting surface (wing or blade) is reflected in the kinetic energy of the wake. Consideration of the energy in the wake is sufficient to define absolute minimum limitations on the power requirement to generate a particular thrust. This work applies wake solutions to compare the minimum inviscid propulsive power requirement of wings flapping and in rotation at wing loading conditions reflective of hover through a state of lightly-loaded cruise. It is demonstrated that hovering flapping flight is less efficient than rotary wing propulsion except for the most extreme flap amplitude strokes ([Formula: see text]   >  160°) if operating at large wake wavelength. In cruise, a larger range of flap amplitude kinematics ([Formula: see text]  >  140°) can be aerodynamically more energy efficient for wake wavelengths reflective of biological propulsion. These results imply, based on the observed wing kinematics of continuous steady flight, that flapping propulsion in animals is unlikely to be more efficient than rotary propulsion.

48 CFR 552.238-81 - Modification (Federal Supply Schedule).

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Electronic File Updates. The Contractor shall update electronic file submissions to reflect all modifications... electronic file updates. The Contractor may transmit price reductions, item deletions, and corrections... workdays from the last day of the calendar quarter. (2) At a minimum, the Contractor shall distribute each...

76 FR 48159 - Integrated System Power Rates

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

... rates, as are those of Southwestern's transmission facilities, which consist of 1,380 miles of high... system investments within the required number of years. As indicated in the Integrated System Rate Design... decrease slightly to reflect the incorporation of the White River Minimum Flows legislation as applied to...

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).

Code of Federal Regulations, 2010 CFR

2010-07-01

... control technology currently available (BPT). (a) Erosion and sediment controls. Design, install and... minimum, such controls must be designed, installed and maintained to: (1) Control stormwater volume and... appropriate controls. (d) Pollution prevention measures. Design, install, implement, and maintain effective...

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).

Code of Federal Regulations, 2011 CFR

2011-07-01

... control technology currently available (BPT). (a) Erosion and sediment controls. Design, install and... minimum, such controls must be designed, installed and maintained to: (1) Control stormwater volume and... appropriate controls. (d) Pollution prevention measures. Design, install, implement, and maintain effective...

Committed sea-level rise for the next century from Greenland ice sheet dynamics during the past decade

PubMed Central

Price, Stephen F.; Payne, Antony J.; Howat, Ian M.; Smith, Benjamin E.

2011-01-01

We use a three-dimensional, higher-order ice flow model and a realistic initial condition to simulate dynamic perturbations to the Greenland ice sheet during the last decade and to assess their contribution to sea level by 2100. Starting from our initial condition, we apply a time series of observationally constrained dynamic perturbations at the marine termini of Greenland’s three largest outlet glaciers, Jakobshavn Isbræ, Helheim Glacier, and Kangerdlugssuaq Glacier. The initial and long-term diffusive thinning within each glacier catchment is then integrated spatially and temporally to calculate a minimum sea-level contribution of approximately 1 ± 0.4 mm from these three glaciers by 2100. Based on scaling arguments, we extend our modeling to all of Greenland and estimate a minimum dynamic sea-level contribution of approximately 6 ± 2 mm by 2100. This estimate of committed sea-level rise is a minimum because it ignores mass loss due to future changes in ice sheet dynamics or surface mass balance. Importantly, > 75% of this value is from the long-term, diffusive response of the ice sheet, suggesting that the majority of sea-level rise from Greenland dynamics during the past decade is yet to come. Assuming similar and recurring forcing in future decades and a self-similar ice dynamical response, we estimate an upper bound of 45 mm of sea-level rise from Greenland dynamics by 2100. These estimates are constrained by recent observations of dynamic mass loss in Greenland and by realistic model behavior that accounts for both the long-term cumulative mass loss and its decay following episodic boundary forcing. PMID:21576500

Committed sea-level rise for the next century from Greenland ice sheet dynamics during the past decade.

PubMed

Price, Stephen F; Payne, Antony J; Howat, Ian M; Smith, Benjamin E

2011-05-31

We use a three-dimensional, higher-order ice flow model and a realistic initial condition to simulate dynamic perturbations to the Greenland ice sheet during the last decade and to assess their contribution to sea level by 2100. Starting from our initial condition, we apply a time series of observationally constrained dynamic perturbations at the marine termini of Greenland's three largest outlet glaciers, Jakobshavn Isbræ, Helheim Glacier, and Kangerdlugssuaq Glacier. The initial and long-term diffusive thinning within each glacier catchment is then integrated spatially and temporally to calculate a minimum sea-level contribution of approximately 1 ± 0.4 mm from these three glaciers by 2100. Based on scaling arguments, we extend our modeling to all of Greenland and estimate a minimum dynamic sea-level contribution of approximately 6 ± 2 mm by 2100. This estimate of committed sea-level rise is a minimum because it ignores mass loss due to future changes in ice sheet dynamics or surface mass balance. Importantly, > 75% of this value is from the long-term, diffusive response of the ice sheet, suggesting that the majority of sea-level rise from Greenland dynamics during the past decade is yet to come. Assuming similar and recurring forcing in future decades and a self-similar ice dynamical response, we estimate an upper bound of 45 mm of sea-level rise from Greenland dynamics by 2100. These estimates are constrained by recent observations of dynamic mass loss in Greenland and by realistic model behavior that accounts for both the long-term cumulative mass loss and its decay following episodic boundary forcing.

Comparison of Ear-Canal Reflectance and Umbo Velocity in Patients with Conductive Hearing Loss

NASA Astrophysics Data System (ADS)

Merchant, Gabrielle R.; Nakajima, Hideko H.; Pisano, Dominic V.; Röösli, Christof; Hamade, Mohamad A.; Mafoud, Lorice; Halpin, Christopher F.; Merchant, Saumil N.; Rosowski, John J.

2011-11-01

Patients who present at hearing clinics with a conductive hearing loss (CHL) in the presence of an intact, healthy tympanic membrane create a unique challenge for otologists. While patient counseling, treatment options, and outcome vary with differing middle-ear pathologies, a non-invasive diagnostic that can differentiate between these pathologies does not currently exist. We evaluated the clinical utility and diagnostic accuracy of two non-invasive measures of middle-ear mechanics: ear-canal reflectance (ECR) and umbo velocity (VU).

Reflective limiters based on self-induced violation of C T symmetry

NASA Astrophysics Data System (ADS)

Makri, Eleana; Thomas, Roney; Kottos, Tsampikos

2018-04-01

Non-Hermitian bipartite photonic lattices with charge-conjugation (C T ) symmetry can support resonant defect modes which are resilient to bipartite losses and structural imperfections. When, however, a (self-)induced violation of the C T symmetry occurs via tiny permittivity variations, the resonant mode is exposed to the bipartite losses and it is destroyed. Consequently, the transmission peak is suppressed while the reflectance becomes (almost) unity. We propose the use of such photonic systems as power switches, limiters, and sensors.

On effective and optical resolutions of diffraction data sets.

PubMed

Urzhumtseva, Ludmila; Klaholz, Bruno; Urzhumtsev, Alexandre

2013-10-01

In macromolecular X-ray crystallography, diffraction data sets are traditionally characterized by the highest resolution dhigh of the reflections that they contain. This measure is sensitive to individual reflections and does not refer to the eventual data incompleteness and anisotropy; it therefore does not describe the data well. A physically relevant and robust measure that provides a universal way to define the `actual' effective resolution deff of a data set is introduced. This measure is based on the accurate calculation of the minimum distance between two immobile point scatterers resolved as separate peaks in the Fourier map calculated with a given set of reflections. This measure is applicable to any data set, whether complete or incomplete. It also allows characterizion of the anisotropy of diffraction data sets in which deff strongly depends on the direction. Describing mathematical objects, the effective resolution deff characterizes the `geometry' of the set of measured reflections and is irrelevant to the diffraction intensities. At the same time, the diffraction intensities reflect the composition of the structure from physical entities: the atoms. The minimum distance for the atoms typical of a given structure is a measure that is different from and complementary to deff; it is also a characteristic that is complementary to conventional measures of the data-set quality. Following the previously introduced terms, this value is called the optical resolution, dopt. The optical resolution as defined here describes the separation of the atomic images in the `ideal' crystallographic Fourier map that would be calculated if the exact phases were known. The effective and optical resolution, as formally introduced in this work, are of general interest, giving a common `ruler' for all kinds of crystallographic diffraction data sets.

Finding Positive Meaning after Loss: The Mediating Role of Reflection for Bereaved Individuals

ERIC Educational Resources Information Center

Boyraz, Guler; Horne, Sharon G.; Sayger, Thomas V.

2010-01-01

This study examined the mediating effect of reflection on the relationship between search for meaning, positive affect, negative affect, and positive meaning-finding among 380 bereaved individuals. Using structural equation modeling, reflection was found to mediate the relationship between search for meaning, affect (positive and negative), and…

The Formation Environment of Jupiter's Moons

NASA Technical Reports Server (NTRS)

Turner, Neal; Lee, Man Hoi; Sano, Takayoshi

2012-01-01

Do circumjovian disk models have conductivities consistent with the assumed accretion stresses? Broadly, YES, for both minimum-mass and gas-starved models: magnetic stresses are weak in the MM models, as needed to keep the material in place. Stresses are stronger in the gas-starved models, as assumed in deriving the flow to the planet. However, future minimum-mass modeling may need to consider the loss of dust-depleted gas from the surface layers to the planet. The gas-starved models should have stress varying in radius. Dust evolution is a key process for further study, since the recombination occurs on the grains.

Temperature and evaporative water loss of leaf-sitting frogs: the role of reflection spectra

PubMed Central

Blount, Chris; Dickinson, Mark

2016-01-01

ABSTRACT The near infrared reflection peak in some frogs has been speculated to be either for enhancing crypticity, or to help them with thermoregulation. The theoretical background for the thermoregulatory processes has been established before, but little consideration has been given to the contribution from the frogs' reflection spectra differences. In this investigation, the reflection spectra from a range of different species of frogs were taken and combined with precise surface area measurements of frogs and an approximation to the mass transfer coefficient of agar frog models. These were then used to simulate the temperature and water evaporation in anurans with and without the near infrared reflective peak. We have shown that the presence of the near infrared reflection peak can contribute significantly to the temperature and evaporative water loss of a frog. The significance of the steady-state temperature differences between frogs with and without the near infrared reflection peak is discussed in a realistic and an extreme scenario. Temperature differences of up to 3.2°C were found, and the rehydration period was increased by up to 16.7%, although this does not reduce the number of rehydration events between dawn and dusk. PMID:27793832

Competition Between Radial Loss and EMIC Wave Scattering of MeV Electrons During Strong CME-shock Driven Storms

NASA Astrophysics Data System (ADS)

Hudson, M. K.; Jaynes, A. N.; Li, Z.; Malaspina, D.; Millan, R. M.; Patel, M.; Qin, M.; Shen, X.; Wiltberger, M. J.

2017-12-01

The two strongest storms of Solar Cycle 24, 17 March and 22 June 2015, provide a contrast between magnetospheric response to CME-shocks at equinox and solstice. The 17 March CME-shock initiated storm produced a stronger ring current response with Dst = - 223 nT, while the 22 June CME-shock initiated storm reached a minimum Dst = - 204 nT. The Van Allen Probes ECT instrument measured a dropout in flux for both events which can be characterized by magnetopause loss at higher L values prior to strong recovery1. However, rapid loss is seen at L 3 for the June storm at high energies with maximum drop in the 5.2 MeV channel of the REPT instrument coincident with the observation of EMIC waves in the H+ band by the EMFISIS wave instrument. The rapid time scale of loss can be determined from the 65 minute delay in passage of the Probe A relative to the Probe B spacecraft. The distinct behavior of lower energy electrons at higher L values has been modeled with MHD-test particle simulations, while the rapid loss of higher energy electrons is examined in terms of the minimum resonant energy criterion for EMIC wave scattering, and compared with the timescale for loss due to EMIC wave scattering which has been modeled for other storm events.2 1Baker, D. N., et al. (2016), Highly relativistic radiation belt electron acceleration, transport, and loss: Large solar storm events of March and June 2015, J. Geophys. Res. Space Physics, 121, 6647-6660, doi:10.1002/2016JA022502. 2Li, Z., et al. (2014), Investigation of EMIC wave scattering as the cause for the BARREL 17 January 2013 relativistic electron precipitation event: A quantitative comparison of simulation with observations, Geophys. Res. Lett., 41, 8722-8729, doi:10.1002/2014GL062273.

Comparative efficacy of storage bags, storability and damage potential of bruchid beetle.

PubMed

Harish, G; Nataraja, M V; Ajay, B C; Holajjer, Prasanna; Savaliya, S D; Gedia, M V

2014-12-01

Groundnut during storage is attacked by number of stored grain pests and management of these insect pests particularly bruchid beetle, Caryedon serratus (Oliver) is of prime importance as they directly damage the pod and kernels. In this regard different storage bags that could be used and duration up to which we can store groundnut has been studied. Super grain bag recorded minimum number of eggs laid and less damage and minimum weight loss in pods and kernels in comparison to other storage bags. Analysis of variance for multiple regression models were found to be significant in all bags for variables viz, number of eggs laid, damage in pods and kernels, weight loss in pods and kernels throughout the season. Multiple comparison results showed that there was a high probability of eggs laid and pod damage in lino bag, fertilizer bag and gunny bag, whereas super grain bag was found to be more effective in managing the C. serratus owing to very low air circulation.

Sampled-Data Consensus of Linear Multi-agent Systems With Packet Losses.

PubMed

Zhang, Wenbing; Tang, Yang; Huang, Tingwen; Kurths, Jurgen

In this paper, the consensus problem is studied for a class of multi-agent systems with sampled data and packet losses, where random and deterministic packet losses are considered, respectively. For random packet losses, a Bernoulli-distributed white sequence is used to describe packet dropouts among agents in a stochastic way. For deterministic packet losses, a switched system with stable and unstable subsystems is employed to model packet dropouts in a deterministic way. The purpose of this paper is to derive consensus criteria, such that linear multi-agent systems with sampled-data and packet losses can reach consensus. By means of the Lyapunov function approach and the decomposition method, the design problem of a distributed controller is solved in terms of convex optimization. The interplay among the allowable bound of the sampling interval, the probability of random packet losses, and the rate of deterministic packet losses are explicitly derived to characterize consensus conditions. The obtained criteria are closely related to the maximum eigenvalue of the Laplacian matrix versus the second minimum eigenvalue of the Laplacian matrix, which reveals the intrinsic effect of communication topologies on consensus performance. Finally, simulations are given to show the effectiveness of the proposed results.In this paper, the consensus problem is studied for a class of multi-agent systems with sampled data and packet losses, where random and deterministic packet losses are considered, respectively. For random packet losses, a Bernoulli-distributed white sequence is used to describe packet dropouts among agents in a stochastic way. For deterministic packet losses, a switched system with stable and unstable subsystems is employed to model packet dropouts in a deterministic way. The purpose of this paper is to derive consensus criteria, such that linear multi-agent systems with sampled-data and packet losses can reach consensus. By means of the Lyapunov function approach and the decomposition method, the design problem of a distributed controller is solved in terms of convex optimization. The interplay among the allowable bound of the sampling interval, the probability of random packet losses, and the rate of deterministic packet losses are explicitly derived to characterize consensus conditions. The obtained criteria are closely related to the maximum eigenvalue of the Laplacian matrix versus the second minimum eigenvalue of the Laplacian matrix, which reveals the intrinsic effect of communication topologies on consensus performance. Finally, simulations are given to show the effectiveness of the proposed results.

Fine manipulation of sound via lossy metamaterials with independent and arbitrary reflection amplitude and phase.

PubMed

Zhu, Yifan; Hu, Jie; Fan, Xudong; Yang, Jing; Liang, Bin; Zhu, Xuefeng; Cheng, Jianchun

2018-04-24

The fine manipulation of sound fields is critical in acoustics yet is restricted by the coupled amplitude and phase modulations in existing wave-steering metamaterials. Commonly, unavoidable losses make it difficult to control coupling, thereby limiting device performance. Here we show the possibility of tailoring the loss in metamaterials to realize fine control of sound in three-dimensional (3D) space. Quantitative studies on the parameter dependence of reflection amplitude and phase identify quasi-decoupled points in the structural parameter space, allowing arbitrary amplitude-phase combinations for reflected sound. We further demonstrate the significance of our approach for sound manipulation by producing self-bending beams, multifocal focusing, and a single-plane two-dimensional hologram, as well as a multi-plane 3D hologram with quality better than the previous phase-controlled approach. Our work provides a route for harnessing sound via engineering the loss, enabling promising device applications in acoustics and related fields.

A Comparative Study of the Bidirectional Reflectance Distribution Function of Several Surfaces as a Mid-wave Infrared Diffuse Reflectance Standard

DTIC Science & Technology

2009-03-01

it for the symbology used in this document before reading this chapter. 2.1 BRDF Development In this section, the BRDF will first be briefly be...geometric occlusion term, which was de- picted in Figure 6. This term in the Cook-Torrance model describes the shadowing and masking effects, and is...where the min() function selects the least of the arguments. The first term in the minimum function is where no occlusion of any kind is occurring

Nuclear Strategy and World Order: The United States Imperative.

ERIC Educational Resources Information Center

Beres, Louis Rene

The current U.S. nuclear strategy goes beyond the legitimate objective of survivable strategic forces to active preparation for nuclear war. The Reagan administration strategy rejects minimum deterrence and prepares for a nuclear war that might be protracted and controlled. The strategy reflects the understanding that a combination of counterforce…

Money and Motivation

ERIC Educational Resources Information Center

Bishop, John H.

2004-01-01

Nations other than the U.S. elicit better performance from their students through the use of high-stakes graduation exams. Along these same lines, Michigan now links college scholarships to high school test results. Michigan has rejected the use of minimum-competency exams, largely because it wanted the state's high-school test to reflect more…

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Design, install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. At a minimum, such controls must be designed, installed and maintained to: (1) Control... prohibited unless managed by appropriate controls. (d) Pollution prevention measures. Design, install...

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Design, install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. At a minimum, such controls must be designed, installed and maintained to: (1) Control... design, installation and maintenance of erosion and sediment controls must address factors such as the...

40 CFR 450.21 - Effluent limitations reflecting the best practicable technology currently available (BPT).

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Design, install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. At a minimum, such controls must be designed, installed and maintained to: (1) Control... design, installation and maintenance of erosion and sediment controls must address factors such as the...

The X-ray Variability of Eta Car, 1996-2010

NASA Technical Reports Server (NTRS)

Corcoran, Michael F.; Hamaguchi, K.; Gull, T.; Owocki, S.; Pittard, J.

2010-01-01

X-ray photometry in the 2-10 keY band of the the supermassive binary star Eta Car has been measured with the Rossi X-ray Timing Explorer from 1996-2010. The ingress to X-ray minimum is consistent with a period of 2024 days. The 2009 X-ray minimum began on January 162009 and showed an unexpectedly abrupt recovery starting after 12 Feb 2009. The X-ray colors become harder about half-way through all three minima and continue until flux recovery. The behavior of the fluxes and X-ray colors for the most recent X-ray minimum, along with Chandra high resolution grating spectra at key phases suggests a significant change in the inner wind of Eta Car, a possible indicator that the star is entering a new unstable phase of mass loss.

Influence of limited heliostat motion onto the efficiency of a solar field

NASA Astrophysics Data System (ADS)

Burisch, Michael; Mutuberria, Amaia; Olasolo, David; Villasante, Cristobal

2016-05-01

The efficiency of a central receiver solar thermal power plant depends on the ability of the heliostats to reflect the sunlight onto the receiver. Reflecting the sunlight over the course of a year requires the drive system to move the heliostat over a wide range of azimuth and elevation angles, which results to be a challenge in the development of new low cost drive system designs. Reducing this range simplifies the design and would, therefore, enable further cost savings. At the same time, reducing the range would also cause efficiency losses of the solar field, as the heliostats would not be able to reflect the sunlight under all conditions. Analyzing the range of motions required for each heliostat and the flux contribution of each position allows assessing these losses. With the aim of minimizing the losses an optimal range of heliostat motions can be chosen. It is shown that in combination with properly placing each heliostat in the solar field, the efficiency losses due to the limited motion range can be kept low as most of the receiver incident flux results from a small range of heliostat orientations. If such a heliostat design allow for sufficiently high costs saving per heliostat the potential losses can be compensated by adding more heliostats to the field, while still reducing the overall expenses.

Facile synthesis of Fe3O4/C composites for broadband microwave absorption properties

NASA Astrophysics Data System (ADS)

Liu, Xiang; Ma, Yating; Zhang, Qinfu; Zheng, Zhiming; Wang, Lai-Sen; Peng, Dong-Liang

2018-07-01

Rod-like and flower-like Fe3O4/C composites were successfully synthesized via a facile approach in aqueous phase. The morphologies, structures and static magnetic properties of as-prepared rod-like and flower-like Fe3O4/C composites were characterized thoroughly. The relative complex permittivity and permeability of Fe3O4/C/paraffin composites were recorded by a vector network analyzer (VNA) in the range of 1-18 GHz. The resonant-antiresonant electromagnetic behavior was observed simultaneously in both rod-like and flower-like Fe3O4/C composites. Moreover, the resonant-antiresonant behavior was explained using displacement current lag at the "core/shell" interface. The flower-like Fe3O4/C/paraffin composites show superior microwave absorption performance with minimum reflection loss (RL) of up to -18.73 dB at 15.37 GHz. Comparatively, the rod-like Fe3O4/C/paraffin composites have uncommon continuous trinal absorption peaks at a thickness of 2.5 mm that effectively broadens the absorption bandwidth which is from 8.0 to 13.4 GHz. Furthermore, the microwave absorption mechanism has been discussed to provide a novel design for microwave absorption materials.

Effects of Natural Rubber on Microwave Absorption Characteristics of Some Li-Ni-Zn Ferrite-Thermoplastic Natural Rubber Composites

NASA Astrophysics Data System (ADS)

Abdul Hamid, Siti Atkah; Abdullah, Mustaffa Hj.; Ahmad, Sahrim Hj.; Mansor, Abdul Aziz; Yusoff, Ahmad Nazlim

2002-09-01

A microwave (Li0.5Fe0.5)0.4Ni0.3Zn0.3Fe2O4 (LNZ) ferrite was prepared by a conventional sintering method in air. Thermoplastic natural rubber (TPNR) was prepared from polypropylene (PP) and natural rubber (NR) in the ratios of 80:20, 70:30, 60:40, 50:50 and 40:60 with liquid natural rubber as a compatibilizer by a melt blending technique. LNZ ferrite-TPNR composites with 20 wt% ferrite filler were prepared using a Brabender plasticorder internal mixer. The microwave electromagnetic properties of the composites were studied in the frequency range of 0.3-13.5 GHz using a microwave vector network analyzer (MVNA). The real and imaginary components of the relative complex dielectric permittivity (\\varepsilonr*=\\varepsilonr\\prime-j\\varepsilonr\\prime\\prime) and magnetic permeability (μr*=μr\\prime-jμr\\prime\\prime) were calculated from the measured complex scattering parameters (S11* and S12*) using the Nicolson-Ross model. The dielectric and magnetic properties were found to depend on the NR and PP content in the composites. The minimum reflection loss (RL) under the matching conditions increases with increasing NR content.

The non-uniformity of fossil preservation.

PubMed

Holland, Steven M

2016-07-19

The fossil record provides the primary source of data for calibrating the origin of clades. Although minimum ages of clades are given by the oldest preserved fossil, these underestimate the true age, which must be bracketed by probabilistic methods based on multiple fossil occurrences. Although most of these methods assume uniform preservation rates, this assumption is unsupported over geological timescales. On geologically long timescales (more than 10 Myr), the origin and cessation of sedimentary basins, and long-term variations in tectonic subsidence, eustatic sea level and sedimentation rate control the availability of depositional facies that preserve the environments in which species lived. The loss of doomed sediments, those with a low probability of preservation, imparts a secular trend to fossil preservation. As a result, the fossil record is spatially and temporally non-uniform. Models of fossil preservation should reflect this non-uniformity by using empirical estimates of fossil preservation that are spatially and temporally partitioned, or by using indirect proxies of fossil preservation. Geologically, realistic models of preservation will provide substantially more reliable estimates of the origination of clades.This article is part of the themed issue 'Dating species divergences using rocks and clocks'. © 2016 The Author(s).

Reducing Heat Gains and Cooling Loads Through Roof Structure Configurations of A House in Medan

NASA Astrophysics Data System (ADS)

Handayani Lubis, Irma; Donny Koerniawan, Mochamad

2018-05-01

Heat gains and heat losses through building surfaces are the main factors that determine the building’s cooling and heating loads. Roof as a building surface that has the most exposed area to the sun, contribute most of heat gains in the building. Therefore, the amount of solar heat gains on the roofs need to be minimized by roof structure configurations. This research aims to discover the optimization of roof structure configurations (coating material, structure material, inclination, overhang, and insulation) as one of passive design strategies that reduce heat gains and cooling loads of a house in Medan. The result showed that case four, white-painted metal roof combined with 45° roof pitched, 1.5m overhang, and addition of insulation, indicates the minimum heat gains production and the less cooling loads during clear sky day but not in the overcast sky condition. In conclusion, heat gains and cooling loads of a house in Medan could be diminished during clear sky day by the addition of roof coating with high reflectance low solar absorbtance, the slope roof, the extension of wider veranda, and the addition of insulation in the roof structure.

Highly anisotropic black phosphorous-graphene hybrid architecture for ultrassensitive plasmonic biosensing: Theoretical insight

NASA Astrophysics Data System (ADS)

Yuan, Yufeng; Yu, Xiantong; Ouyang, Qingling; Shao, Yonghong; Song, Jun; Qu, Junle; Yong, Ken-Tye

2018-04-01

This study proposed a novel highly anisotropic surface plasmon resonance (SPR) biosensor employing emerging 2D black phosphorus (BP) and graphene atomic layers. Light absorption and energy loss were well balanced by optimizing gold film thickness and number of BP layers to generate the strongest SPR excitation. The proposed SPR biosensor was designed by the phase-modulation approach and is more sensitive to biomolecule bindings, providing 3 orders of magnitude higher sensitivity than the red-shift in SPR angle. Our results show the optimized configuration was 48 nm Au film coated with 4-layer BP crystal to produce the sharpest phase variation (up to 89.8975°), and lowest minimum reflectivity (1.9119  ×  10-7). Detection sensitivity up to 7.4914  ×  104 degree/refractive index unit is almost 4.5 times enhanced compared to monolayer graphene-based SPR sensors with 48 nm Au film. The anisotropic BP layers act as a polarizer, so the proposed SPR biosensor would exhibit optically tunable detection sensitivity, making it a promising candidate for exploring highly anisotropic platforms in biosensing.

The non-uniformity of fossil preservation

PubMed Central

2016-01-01

The fossil record provides the primary source of data for calibrating the origin of clades. Although minimum ages of clades are given by the oldest preserved fossil, these underestimate the true age, which must be bracketed by probabilistic methods based on multiple fossil occurrences. Although most of these methods assume uniform preservation rates, this assumption is unsupported over geological timescales. On geologically long timescales (more than 10 Myr), the origin and cessation of sedimentary basins, and long-term variations in tectonic subsidence, eustatic sea level and sedimentation rate control the availability of depositional facies that preserve the environments in which species lived. The loss of doomed sediments, those with a low probability of preservation, imparts a secular trend to fossil preservation. As a result, the fossil record is spatially and temporally non-uniform. Models of fossil preservation should reflect this non-uniformity by using empirical estimates of fossil preservation that are spatially and temporally partitioned, or by using indirect proxies of fossil preservation. Geologically, realistic models of preservation will provide substantially more reliable estimates of the origination of clades. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325828

A geochemical model of the Platanares geothermal system, Honduras

USGS Publications Warehouse

Janik, C.J.; Truesdell, A.H.; Goff, F.; Shevenell, L.; Stallard, M.L.; Trujillo, P.E.; Counce, D.

1991-01-01

Results of exploration drilling combined with results of geologic, geophysical, and hydrogeochemical investigations have been used to construct a geochemical model of the Platanares geothermal system, Honduras. Three coreholes were drilled, two of which produced fluids from fractured Miocene andesite and altered Cretaceous to Eocene conglomerate at 450 to 680 m depth. Large volume artesian flows of 160-165??C, predominantly bicarbonate water are chemically similar to, but slightly less saline than widespread boiling hot-spring waters. The chemistry of the produced fluid is dominated by equilibrium reactions in sedimentary rocks at greater depths and higher temperatures than those measured in the wells. Chemical, isotope, and gas geothermometers indicate a deep fluid temperature of 200-245??C and reflect a relatively short residence time in the fractures feeding the wells. Chloride-enthalpy relations as well as isotopic and chemical compositions of well discharges, thermal springs, and local cold waters support a conceptual model of ascending high-temperature (minimum 225??C) parent fluid that has cooled conductively to form the 160-165??C shallow (to 680 m) fluid encountered by the wells. The hot-spring waters are formed by boiling and steam loss from more or less conductively cooled parent fluid. The more dilute boiling spring waters (Cl = ???32 mg/kg) have cooled from > 225??C to about 160??C by conduction and from 160??C to 98??C by boiling. The most concentrated boiling spring waters (Cl = 37 mg/kg) have cooled from > 225??C to about 200??C by conduction and from 200??C to 98??C by boiling. Intermediate concentrations reflect mixed cooling paths. ?? 1991.

Spectral Dimensionality and Scale of Urban Radiance

NASA Technical Reports Server (NTRS)

Small, Christopher

2001-01-01

Characterization of urban radiance and reflectance is important for understanding the effects of solar energy flux on the urban environment as well as for satellite mapping of urban settlement patterns. Spectral mixture analyses of Landsat and Ikonos imagery suggest that the urban radiance field can very often be described with combinations of three or four spectral endmembers. Dimensionality estimates of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) radiance measurements of urban areas reveal the existence of 30 to 60 spectral dimensions. The extent to which broadband imagery collected by operational satellites can represent the higher dimensional mixing space is a function of both the spatial and spectral resolution of the sensor. AVIRIS imagery offers the spatial and spectral resolution necessary to investigate the scale dependence of the spectral dimensionality. Dimensionality estimates derived from Minimum Noise Fraction (MNF) eigenvalue distributions show a distinct scale dependence for AVIRIS radiance measurements of Milpitas, California. Apparent dimensionality diminishes from almost 40 to less than 10 spectral dimensions between scales of 8000 m and 300 m. The 10 to 30 m scale of most features in urban mosaics results in substantial spectral mixing at the 20 m scale of high altitude AVIRIS pixels. Much of the variance at pixel scales is therefore likely to result from actual differences in surface reflectance at pixel scales. Spatial smoothing and spectral subsampling of AVIRIS spectra both result in substantial loss of information and reduction of apparent dimensionality, but the primary spectral endmembers in all cases are analogous to those found in global analyses of Landsat and Ikonos imagery of other urban areas.

Prime focus architectures for large space telescopes: reduce surfaces to save cost

NASA Astrophysics Data System (ADS)

Breckinridge, J. B.; Lillie, C. F.

2016-07-01

Conceptual architectures are now being developed to identify future directions for post JWST large space telescope systems to operate in the UV Optical and near IR regions of the spectrum. Here we show that the cost of optical surfaces within large aperture telescope/instrument systems can exceed $100M/reflection when expressed in terms of the aperture increase needed to over come internal absorption loss. We recommend a program in innovative optical design to minimize the number of surfaces by considering multiple functions for mirrors. An example is given using the Rowland circle imaging spectrometer systems for UV space science. With few exceptions, current space telescope architectures are based on systems optimized for ground-based astronomy. Both HST and JWST are classical "Cassegrain" telescopes derived from the ground-based tradition to co-locate the massive primary mirror and the instruments at the same end of the metrology structure. This requirement derives from the dual need to minimize observatory dome size and cost in the presence of the Earth's 1-g gravitational field. Space telescopes, however function in the zero gravity of space and the 1- g constraint is relieved to the advantage of astronomers. Here we suggest that a prime focus large aperture telescope system in space may have potentially have higher transmittance, better pointing, improved thermal and structural control, less internal polarization and broader wavelength coverage than Cassegrain telescopes. An example is given showing how UV astronomy telescopes use single optical elements for multiple functions and therefore have a minimum number of reflections.

Split-spectrum intensity-based optical fiber sensors for measurement of microdisplacement, strain, and pressure

NASA Astrophysics Data System (ADS)

Wang, Anbo; Miller, Mark S.; Plante, Angela J.; Gunther, Michael F.; Murphy, Kent A.; Claus, Richard O.

1996-05-01

A self-referencing technique compensating for fiber losses and source fluctuations in reflective air-gap intensity-based optical fiber sensors is described. A dielectric multilayer short-wave-pass filter is fabricated onto or attached to the output end face of the lead-in-lead-out multimode fiber. The incoming broadband light from a white light or a light-emitting diode is partially reflected at the filter. The transmitted light through the filter projects onto a mirror. The light returning from the reflecting mirror is recoupled into the lead-in-lead-out fiber. These two reflections from the filter and the reflecting mirror are spectrally separated at the detector end. The power ratio of these two reflections is insensitive to source fluctuations and fiber-bending loss. However, because the second optical signal depends on the air-gap separation between the end face of the lead-in-lead-out fiber and the reflecting mirror, the ratio provides the information on the air-gap length. A resolution of 0.13 mu m has been obtained over a microdisplacement measurement range of 0-254 mu m. The sensor is shown to be insensitive to both fiber-bending losses and variations in source power. Based on this approach, a fiber-strain sensor was fabricated with a multilayer interference filter directly fabricated on the end face of the fiber. A resolution of 13.4 microstrain was obtained over a measurement range of 0-20,000 microstrain with a gauge length of 10 mm. The split-spectrum method is also incorporated into a diaphragm displacement-based pressure sensor with a demonstrated resolution of 450 Pa over a measurement range of 0-0.8 MPa.

Effects of the LBV Primary's Mass-loss Rate on the 3D Hydrodynamics of eta Carinae's Colliding Winds

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Cocoran, M.; Okazaki, A.; Owocki, S.; Russell, C.; Hamaguchi, K.; Clementel, N; Groh, J.; Hillier, D. J.

2013-01-01

At the heart of eta Carinae's spectacular "Homunculus" nebula lies an extremely luminous (L(sub Total) greater than approximately 5 × 10(exp 6) solar luminosity) colliding wind binary with a highly eccentric (e approximately 0.9), 5.54-year orbit (Figure 1). The primary of the system, a Luminous Blue Variable (LBV), is our closest (D approximately 2.3 kpc) and best example of a pre-hypernova or pre-gamma ray burst environment. The remarkably consistent and periodic RXTE X-ray light curve surprisingly showed a major change during the system's last periastron in 2009, with the X-ray minimum being approximately 50% shorter than the minima of the previous two cycles1. Between 1998 and 2011, the strengths of various broad stellar wind emission lines (e.g. Halpha, Fe II) in line-of-sight (l.o.s.) also decreased by factors of 1.5 - 3 relative to the continuum2. The current interpretation for these changes is that they are due to a gradual factor of 2 - 4 drop in the primary's mass-loss rate over the last approximately 15 years1, 2. However, while a secular change is seen for a direct view of the central source, little to no change is seen in profiles at high stellar latitudes or reflected off of the dense, circumbinary material known as the "Weigelt blobs"2, 3. Moreover, model spectra generated with CMFGEN predict that a factor of 2 - 4 drop in the primary's mass-loss rate should lead to huge changes in the observed spectrum, which thus far have not been seen. Here we present results from large- (plus or minus 1620 AU) and small- (plus or minus 162 AU) domain, full 3D smoothed particle hydrodynamics (SPH) simulations of eta Car's massive binary colliding winds for three different primary-star mass-loss rates (2.4, 4.8, and 8.5 × 10(exp -4) solar mass/yr). The goal is to investigate how the mass-loss rate affects the 3D geometry and dynamics of eta Car's optically-thick wind and spatially-extended wind-wind collision (WWC) regions, both of which are known sources of observed X-ray, optical, UV, and near-IR emission and absorption. We use two domain sizes in order to better understand how the primary's mass-loss rate influences the various observables that form at different length scales. The 3D simulations provide information important for helping constrain ? Car's recent mass-loss history and future state.

Real or perceived impediments to minimum pricing of alcohol in Australia: public opinion, the industry and the law.

PubMed

Chalmers, Jenny; Carragher, Natacha; Davoren, Sondra; O'Brien, Paula

2013-11-01

A burgeoning body of empirical evidence demonstrates that increases in the price of alcohol can reduce per capita alcohol consumption and harmful drinking. Taxes on alcohol can be raised to increase prices, but this strategy can be undermined if the industry absorbs the tax increase and cross-subsidises the price of one alcoholic beverage with other products. Such loss-leading strategies are not possible with minimum pricing. We argue that a minimum (or floor) price for alcohol should be used as a complement to alcohol taxation. Several jurisdictions have already introduced minimum pricing (e.g., Canada, Ukraine) and others are currently investigating pathways to introduce a floor price (e.g., Scotland). Tasked by the Australian government to examine the public interest case for a minimum price, Australia's peak preventative health agency recommended against setting one at the present time. The agency was concerned that there was insufficient Australian specific modelling evidence to make robust estimates of the net benefits. Nonetheless, its initial judgement was that it would be difficult for a minimum price to produce benefits for Australia at the national level. Whilst modelling evidence is certainly warranted to support the introduction of the policy, the development and uptake of policy is influenced by more than just empirical evidence. This article considers three potential impediments to minimum pricing: public opinion and misunderstandings or misgivings about the operation of a minimum price; the strength of alcohol industry objections and measures to undercut the minimum price through discounts and promotions; and legal obstacles including competition and trade law. The analysis of these factors is situated in an Australian context, but has salience internationally. Copyright © 2013 Elsevier B.V. All rights reserved.

Tunable antireflection from conformal Al-doped ZnO films on nanofaceted Si templates

PubMed Central

2014-01-01

Photon harvesting by reducing reflection loss is the basis of photovoltaic devices. Here, we show the efficacy of Al-doped ZnO (AZO) overlayer on ion beam-synthesized nanofaceted silicon for suppressing reflection loss. In particular, we demonstrate thickness-dependent tunable antireflection (AR) from conformally grown AZO layer, showing a systematic shift in the reflection minima from ultraviolet to visible to near-infrared ranges with increasing thickness. Tunable AR property is understood in light of depth-dependent refractive index of nanofaceted silicon and AZO overlayer. This improved AR property significantly increases the fill factor of such textured heterostructures, which reaches its maximum for 60-nm AZO compared to the ones based on planar silicon. This thickness matches with the one that shows the maximum reduction in surface reflectance. PACS 81.07.-b; 42.79.Wc; 81.16.Rf; 81.15.Cd PMID:24808799

Very small IF resonator filters using reflection of shear horizontal wave at free edges of substrate.

PubMed

Kadota, Michio; Ago, Junya; Horiuchi, Hideya; Ikeura, Mamoru

2002-09-01

A shear horizontal (SH) wave has the characteristic of complete reflection at the free edges of a substrate with a large dielectric constant. A conventional surface acoustic wave (SAW) resonator filter requires reflectors consisting of numerous grating fingers on both sides of interdigital transducers (IDTs). On the contrary, it is considered that small-sized and low loss resonator filters without reflectors consisting of grating fingers can be realized by exploiting this characteristic of the SH wave or the Bleustein-Gulyaev-Shimizu (BGS) wave. There are two types of resonator filters: transversely coupled and longitudinally coupled. No transversely coupled filters (neither conventional nor edge-reflection) using the SH wave on a single-crystal substrate have been realized until now, because two transverse modes (symmetrical and asymmetrical modes) are not easily coupled. However, the authors have realized small low loss transversely coupled resonator filters in the range of 25 to 52 MHz using edge reflections of the BGS wave on piezoelectric ceramic (PZT: Pb(Zr,Ti)O3) substrates for the first time by developing methods by which the two transverse modes could be coupled. On the other hand, longitudinally coupled resonator filters using edge reflection of the SH or BGS wave always have large spurious responses because of the even modes in the out-of-band range, because the frequencies of even modes do not coincide with the nulls of the frequency spectra of the IDTs. Consequently, longitudinally coupled resonator filters using the edge reflection of the SH wave have not been realized. By developing a method of reducing the spurious responses without increasing of the insertion loss, the authors have realized small low loss longitudinally coupled resonator filters in the range of 40 to 190 MHz using edge reflection of BGS or SH waves on PZT or 36 degrees-rotated-Y X-propagation LiTaO3 substrates for the first time. Despite being intermediate frequency (IF) filters, their package (3 x 3 x 1.03 mm3) sizes are as small as those of radio frequency (RF) SAW filters.

Agricultural losses related to frost events: use of the 850 hPa level temperature as an explanatory variable of the damage cost

NASA Astrophysics Data System (ADS)

Papagiannaki, K.; Lagouvardos, K.; Kotroni, V.; Papagiannakis, G.

2014-01-01

The objective of this study is to analyze frost damaging events in agriculture, by examining the relationship between the daily minimum temperature at the lower atmosphere (at the pressure level of 850 hPa) and crop production losses. Furthermore, the study suggests a methodological approach for estimating agriculture risk due to frost events, with the aim to estimate the short-term probability and magnitude of frost-related financial losses for different levels of 850 hPa temperature. Compared with near surface temperature forecasts, temperature forecast at the level of 850 hPa is less influenced by varying weather conditions, as well as by local topographical features, thus it constitutes a more consistent indicator of the forthcoming weather conditions. The analysis of the daily monetary compensations for insured crop losses caused by weather events in Greece, during the period 1999-2011, shows that frost is the major meteorological phenomenon with adverse effects on crop productivity in the largest part of the country. Two regions of different geographical latitude are further examined, to account for the differences in the temperature ranges developed within their ecological environment. Using a series of linear and logistic regressions, we found that minimum temperature (at 850 hPa level), grouped in three categories according to its magnitude, and seasonality are significant variables when trying to explain crop damage costs, as well as to predict and quantify the likelihood and magnitude of frost damaging events.

Agricultural losses related to frost events: use of the 850 hPa level temperature as an explanatory variable of the damage cost

NASA Astrophysics Data System (ADS)

Papagiannaki, K.; Lagouvardos, K.; Kotroni, V.; Papagiannakis, G.

2014-09-01

The objective of this study is the analysis of damaging frost events in agriculture, by examining the relationship between the daily minimum temperature in the lower atmosphere (at an isobaric level of 850 hPa) and crop production losses. Furthermore, the study suggests a methodological approach for estimating agriculture risk due to frost events, with the aim of estimating the short-term probability and magnitude of frost-related financial losses for different levels of 850 hPa temperature. Compared with near-surface temperature forecasts, temperature forecasts at the level of 850 hPa are less influenced by varying weather conditions or by local topographical features; thus, they constitute a more consistent indicator of the forthcoming weather conditions. The analysis of the daily monetary compensations for insured crop losses caused by weather events in Greece shows that, during the period 1999-2011, frost caused more damage to crop production than any other meteorological phenomenon. Two regions of different geographical latitudes are examined further, to account for the differences in the temperature ranges developed within their ecological environment. Using a series of linear and logistic regressions, we found that minimum temperature (at an 850 hPa level), grouped into three categories according to its magnitude, and seasonality, are significant variables when trying to explain crop damage costs, as well as to predict and quantify the likelihood and magnitude of damaging frost events.

Antimicrobial activity of gallic acid against thermophilic Campylobacter is strain specific and associated with a loss of calcium ions.

PubMed

Sarjit, Amreeta; Wang, Yi; Dykes, Gary A

2015-04-01

Gallic acid has been suggested as a potential antimicrobial for the control of Campylobacter but its effectiveness is poorly studied. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of gallic acid against Campylobacter jejuni (n = 8) and Campylobacter coli (n = 4) strains was determined. Gallic acid inhibited the growth of five C. jejuni strains and three C. coli strains (MIC: 15.63-250 μg mL(-1)). Gallic acid was only bactericidal to two C. coli strains (MBC: 125 and 62.5 μg mL(-1)). The mechanism of the bactericidal effect against these two strains (and selected non-susceptible controls) was investigated by determining decimal reduction times and by monitoring the loss of cellular content and calcium ions, and changes in cell morphology. Gallic acid did not result in a loss of cellular content or morphological changes in the susceptible strains as compared to the controls. Gallic acid resulted in a loss of calcium ions (0.58-1.53 μg mL(-1) and 0.54-1.17 μg mL(-1), respectively, over a 180 min period) from the susceptible strains but not the controls. Gallic acid is unlikely to be an effective antimicrobial against Campylobacter in a practical sense unless further interventions to ensure an effective bactericidal mode of action against all strains are developed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Minimum pickup velocity ( U pu) of nanoparticles in gas-solid pneumatic conveying

NASA Astrophysics Data System (ADS)

Anantharaman, Aditya; van Ommen, J. Ruud; Chew, Jia Wei

2015-12-01

This paper is the first systematic study of the pneumatic conveying of nanoparticles. The minimum pickup velocity, U pu, of six nanoparticle species of different materials [i.e., silicon dioxide (SiO2), aluminum oxide (Al2O3), and titanium dioxide (TiO2)] and surfaces (i.e., apolar and polar) was determined by the weight loss method. Results show that (1) due to relative lack of hydrogen bonding, apolar nanoparticles had higher mass loss values at the same velocities, mass loss curves with accentuated S-shaped profiles, and lower U pu values, (2) among the three species, SiO2, which has the lowest Hamaker coefficient, exhibited the greatest discrepancy between apolar and polar surfaces with respect to both mass loss curves and U pu values, (3) U mf,polar/ U mf,apolar was between 1 and 3.5 times that of U pu,polar/ U pu,apolar due to greater extents of hydrogen bonding associated with U mf, (4) U pu values were at least an order-of-magnitude lower than that expected from the well-acknowledged U pu correlation (Kalman et al., Powder Technol 160:103-113, 2005) due to agglomeration, (5) although nanoparticles should be categorized as Zone III (Kalman et al. 2005) (or Geldart group C, Powder Technol 7:285-292, 1973), the nanoparticles, and primary and complex agglomerates agreed more with the Zone I (or Geldart group B) correlation.

Mars analog minerals' spectral reflectance characteristics under Martian surface conditions

NASA Astrophysics Data System (ADS)

Poitras, J. T.; Cloutis, E. A.; Salvatore, M. R.; Mertzman, S. A.; Applin, D. M.; Mann, P.

2018-05-01

We investigated the spectral reflectance properties of minerals under a simulated Martian environment. Twenty-eight different hydrated or hydroxylated phases of carbonates, sulfates, and silica minerals were selected based on past detection on Mars through spectral remote sensing data. Samples were ground and dry sieved to <45 μm grain size and characterized by XRD before and after 133 days inside a simulated Martian surface environment (pressure 5 Torr and CO2 fed). Reflectance spectra from 0.35 to 4 μm were taken periodically through a sapphire (0.35-2.5 μm) and zinc selenide (2.5-4 μm) window over a 133-day period. Mineral stability on the Martian surface was assessed through changes in spectral characteristics. Results indicate that the hydrated carbonates studied would be stable on the surface of Mars, only losing adsorbed H2O while maintaining their diagnostic spectral features. Sulfates were less stable, often with shifts in the band position of the SO, Fe, and OH absorption features. Silicas displayed spectral shifts related to SiOH and hydration state of the mineral surface, while diagnostic bands for quartz were stable. Previous detection of carbonate minerals based on 2.3-2.5 μm and 3.4-3.9 μm features appears to be consistent with our results. Sulfate mineral detection is more questionable since there can be shifts in band position related to SO4. The loss of the 0.43 μm Fe3+ band in many of the sulfates indicate that there are fewer potential candidates for Fe3+ sulfates to permanently exist on the Martian surface based on this band. The gypsum sample changed phase to basanite during desiccation as demonstrated by both reflectance and XRD. Silica on Mars has been detected using band depth ratio at 1.91 and 1.96 μm and band minimum position of the 1.4 μm feature, and the properties are also used to determine their age. This technique continues to be useful for positive silica identifications, however, silica age appears to be less consistent with our laboratory data. These results will be useful in spectral libraries for characterizing Martian remote sensed data.

Beam loss detection system in the arcs of the LHC

NASA Astrophysics Data System (ADS)

Arauzo, A.; Bovet, C.

2000-11-01

Over the whole circumference of the LHC, Beam Loss Monitors (BLM) will be needed for a continuous surveillance of fast and slow beam losses. In this paper, the location of the BLMs set outside the magnet cryostats in the arcs is proposed. In order to know the number of protons lost on the beam screen, the sensitivity of each BLM has been computed using the program GEANT 3.21, which generates the shower inside the cryostat. The material and the magnetic fields have been described thoroughly in 3-D and the simulation results show the best locations for 6 BLMs needed around each quadrupole. The number of minimum ionizing particles received for each lost proton serves to define local thresholds to dump the beam when the losses are menacing to quench a magnet.

Piloted Simulation Evaluation of a Model-Predictive Automatic Recovery System to Prevent Vehicle Loss of Control on Approach

NASA Technical Reports Server (NTRS)

Litt, Jonathan; Liu, Yuan; Sowers, T. Shane; Owen, A. Karl; Guo, Ten-Huei

2014-01-01

This paper describes a model-predictive automatic recovery system for aircraft on the verge of a loss-of-control situation. The system determines when it must intervene to prevent an imminent accident, resulting from a poor approach. It estimates the altitude loss that would result from a go-around maneuver at the current flight condition. If the loss is projected to violate a minimum altitude threshold, the maneuver is automatically triggered. The system deactivates to allow landing once several criteria are met. Piloted flight simulator evaluation showed the system to provide effective envelope protection during extremely unsafe landing attempts. The results demonstrate how flight and propulsion control can be integrated to recover control of the vehicle automatically and prevent a potential catastrophe.

Performance-limiting factors for x-ray free electron laser oscillator as a highly coherent, high spectral purity x-ray source

NASA Astrophysics Data System (ADS)

Park, Gunn Tae

X-ray Free Electron Laser (XFEL) is a light source for coherent X-ray using the radiation from relativistic electrons and interaction between the two. In particular, XFEL oscillator(XFELO) uses optical cavity to repeatedly bring back the radiation to electron beam for the interaction. Its optimal performance, maximum single pass gain and minimum round trip loss, critically depends on cavity optics. In ideal case, the optimal performance would be achieved by the periodic radiation mode maximally overlapping with electron beam while the radiation mode is impinging on curved mirror that gives the radiation the focusing, below critical angle and angular divergence being kept small enough at each crystal for Bragg scattering, which is used for near-normal reflection. In reality, there exist various performance degrading factors in the cavity such as heat load on the crystal surface, misalignments of crystals and mirrors and mirror surface errors. In this thesis, we study via both analytic computation and numerical simulation the optimal design and performance of XFELO cavity in the presence of these factors. In optimal design, we implement asymmetric crystals into cavity to enhance the performance. In general, it has undesirable effect of pulse dilation. We present the configuration that avoids pulse length dilation. Then the effects of misalignments, focal length errors and mirror surface errors are to be evaluated and their tolerances are estimated. In particular, the simulation demonstrates that the effect of mirror surface errors on gain and round trip loss is well-within desired performance of XFELO.

Negative space charge effects in photon-enhanced thermionic emission solar converters

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

Segev, G.; Weisman, D.; Rosenwaks, Y.

2015-07-06

In thermionic energy converters, electrons in the gap between electrodes form a negative space charge and inhibit the emission of additional electrons, causing a significant reduction in conversion efficiency. However, in Photon Enhanced Thermionic Emission (PETE) solar energy converters, electrons that are reflected by the electric field in the gap return to the cathode with energy above the conduction band minimum. These electrons first occupy the conduction band from which they can be reemitted. This form of electron recycling makes PETE converters less susceptible to negative space charge loss. While the negative space charge effect was studied extensively in thermionicmore » converters, modeling its effect in PETE converters does not account for important issues such as this form of electron recycling, nor the cathode thermal energy balance. Here, we investigate the space charge effect in PETE solar converters accounting for electron recycling, with full coupling of the cathode and gap models, and addressing conservation of both electric and thermal energy. The analysis shows that the negative space charge loss is lower than previously reported, allowing somewhat larger gaps compared to previous predictions. For a converter with a specific gap, there is an optimal solar flux concentration. The optimal solar flux concentration, the cathode temperature, and the efficiency all increase with smaller gaps. For example, for a gap of 3 μm the maximum efficiency is 38% and the optimal flux concentration is 628, while for a gap of 5 μm the maximum efficiency is 31% and optimal flux concentration is 163.« less

Optical system for UV-laser technological equipment

NASA Astrophysics Data System (ADS)

Fedosov, Yuri V.; Romanova, Galina E.; Afanasev, Maxim Ya.

2017-09-01

Recently there has been an intensive development of intelligent industrial equipment that is highly automated and can be rapidly adjusted for certain details. This equipment can be robotics systems, automatic wrappers and markers, CNC machines and 3D printers. The work equipment considered is the system for selective curing of photopolymers using a UV-laser and UV-radiation in such equipment that leads to additional technical difficulties. In many cases for transporting the radiation from the laser to the point processed, a multi-mirror system is used: however, such systems are usually difficult to adjust. Additionally, such multi-mirror systems are usually used as a part of the equipment for laser cutting of metals using high-power IR-lasers. For the UV-lasers, using many mirrors leads to crucial radiation losses because of many reflections. Therefore, during the development of the optical system for technological equipment using UV-laser we need to solve two main problems: to transfer the radiation for the working point with minimum losses and to include the system for controlling/handling the radiation spot position. We introduce a system for working with UV-lasers with 450mW of power and a wavelength of 0.45 μm based on a fiber system. In our modelling and design, we achieve spot sizes of about 300 μm, and the designed optical and mechanical systems (prototypes) were manufactured and assembled. In this paper, we present the layout of the technological unit, the results of the theoretical modelling of some parts of the system and some experimental results.

Battle Keeps Solar Energy in Receiver

NASA Technical Reports Server (NTRS)

Mcdougal, A. R.; Hale, R. R.

1982-01-01

Mirror structure in solar concentrator reduces heat loss by reflection and reradiation. Baffle reflects entering rays back and forth in solar-concentrator receiver until they reach heat exchanger. Similarly, infrared energy reradiated by heat exchanger is prevented from leaving receiver. Surfaces of baffle and inside wall of receiver are polished and highly reflective at solar and infrared wavelengths.

76 FR 11668 - Minimum Capital

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-03

... Finance Agency The Housing and Economic Recovery Act of 2008 (HERA), Public Law 110-289, 122 Stat. 2654...) ensure profitability in their new books of business without deterring market participation or hindering market recovery; and (c) minimize losses on the mortgages already on their books. D. The Proposed Rule On...

Properties of dynamic magnetic loss of ferrite

NASA Astrophysics Data System (ADS)

Saotome, Hideo; Azuma, Keisuke; Kizuka, Hiroki; Tanaka, Takuma

2018-05-01

The B-H loop of ferrite becomes narrower with a decrease in the excitation frequency. However, even at frequencies lower than 1 kHz, the B-H loop exhibits a certain minimum width, which is referred to as the (DC) hysteresis loop, and its area corresponds to the hysteresis loss. The dynamic magnetic loss is obtained by subtracting the hysteresis loss from the B-H loop area measured at a frequency above 1-10 kHz. The temperature characteristics of the hysteresis and dynamic magnetic losses are determined to be experimentally different, which suggests that the mechanism for the generation of dynamic magnetic loss is not exactly the same as that for the hysteresis loss. The dynamic magnetic loss is expressed using the dynamic magnetic loss parameter, which is a function of B and its time derivative, dB/dt. The dynamic magnetic loss parameter is measured under excitation with a rectangular waveform voltage. A ferrite core of TDK PC47 was used and the maximum magnetic flux density Bm, was set to 350 mT. The measured dynamic magnetic loss parameter was experimentally verified to be one of the intrinsic characteristics of ferrite and was also validated for cases of excitation with sinusoidal waveform voltages.

Phase-demodulation error of a fiber-optic Fabry-Perot sensor with complex reflection coefficients.

PubMed

Kilpatrick, J M; MacPherson, W N; Barton, J S; Jones, J D

2000-03-20

The influence of reflector losses attracts little discussion in standard treatments of the Fabry-Perot interferometer yet may be an important factor contributing to errors in phase-stepped demodulation of fiber optic Fabry-Perot (FFP) sensors. We describe a general transfer function for FFP sensors with complex reflection coefficients and estimate systematic phase errors that arise when the asymmetry of the reflected fringe system is neglected, as is common in the literature. The measured asymmetric response of higher-finesse metal-dielectric FFP constructions corroborates a model that predicts systematic phase errors of 0.06 rad in three-step demodulation of a low-finesse FFP sensor (R = 0.05) with internal reflector losses of 25%.

Biomechanical comparison of two intraoperative mobilization techniques for maxillary distraction osteogenesis: Down-fracture versus non-down-fracture.

PubMed

Yang, Lili; Suzuki, Eduardo Yugo; Suzuki, Boonsiva

2014-01-01

The purpose of this study was to compare the distraction forces and the biomechanical effects between two different intraoperative surgical procedures (down-fracture [DF] and non-DF [NDF]) for maxillary distraction osteogenesis. Eight patients were assigned into two groups according to the surgical procedure: DF, n = 6 versus NDF, n = 2. Lateral cephalograms taken preoperatively (T1), immediately after removal of the distraction device (T2), and after at least a 6 months follow-up period (T3) were analyzed. Assessment of distraction forces was performed during the distraction period. The Mann-Whitney U-test was used to compare the difference in the amount of advancement, the maximum distraction force and the amount of relapse. Although a significantly greater amount of maxillary movement was observed in the DF group (median 9.5 mm; minimum-maximum 7.9-14.1 mm) than in the NDF group (median 5.9 mm; minimum-maximum 4.4-7.6 mm), significantly lower maximum distraction forces were observed in the DF (median 16.4 N; minimum-maximum 15.1-24.6 N) than in the NDF (median 32.9 N; minimum-maximum 27.6-38.2 N) group. A significantly greater amount of dental anchorage loss was observed in the NDF group. Moreover, the amount of relapse observed in the NDF group was approximately 3.5 times greater than in the DF group. In this study, it seemed that, the use of the NDF procedure resulted in lower levels of maxillary mobility at the time of the maxillary distraction, consequently requiring greater amounts of force to advance the maxillary bone. Moreover, it also resulted in a reduced amount of maxillary movement, a greater amount of dental anchorage loss and poor treatment stability.

Low-loss and energy efficient modulation in silicon photonic waveguides by adiabatic elimination scheme

NASA Astrophysics Data System (ADS)

Mrejen, Michael; Suchowski, Haim; Bachelard, Nicolas; Wang, Yuan; Zhang, Xiang

2017-07-01

High-speed Silicon Photonics calls for solutions providing a small footprint, high density, and minimum crosstalk, as exemplified by the recent development of integrated optical modulators. Yet, the performances of such modulators are hindered by intrinsic material losses, which results in low energy efficiency. Using the concept of Adiabatic Elimination, here, we introduce a scheme allowing for the low-loss modulation in densely packed waveguides. Our system is composed of two waveguides, whose coupling is mediated by an intermediate third waveguide. The signal is carried by the two outer modes, while the active control of their coupling is achieved via the intermediate dark mode. The modulation is performed by the manipulation of the central-waveguide mode index, leaving the signal-carrying waveguides unaffected by the loss. We discuss how Adiabatic Elimination provides a solution for mitigating signal losses and designing relatively compact, broadband, and energy-efficient integrated optical modulators.

Magnetic confinement, Alfven wave reflection, and the origins of X-ray and mass-loss 'dividing lines' for late-type giants and supergiants

NASA Technical Reports Server (NTRS)

Rosner, R.; An, C.-H.; Musielak, Z. E.; Moore, R. L.; Suess, S. T.

1991-01-01

A simple qualitative model for the origin of the coronal and mass-loss dividing lines separating late-type giants and supergiants with and without hot, X-ray-emitting corona, and with and without significant mass loss is discussed. The basic physical effects considered are the necessity of magnetic confinement for hot coronal material on the surface of such stars and the large reflection efficiency for Alfven waves in cool exponential atmospheres. The model assumes that the magnetic field geometry of these stars changes across the observed 'dividing lines' from being mostly closed on the high effective temperature side to being mostly open on the low effective temperature side.

26 CFR 1.246-5 - Reduction of holding periods in certain situations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... in which a taxpayer has diminished its risk of loss by holding one or more other positions with... property primarily reflect the performance of— (A) A single firm or enterprise; (B) The same industry or... property. (2) Diminished risk of loss. A taxpayer has diminished its risk of loss on its stock by holding...

Children with Mild Bilateral and Unilateral Hearing Loss: Parents' Reflections on Experiences and Outcomes

ERIC Educational Resources Information Center

Fitzpatrick, Elizabeth; Grandpierre, Viviane; Durieux-Smith, Andrée; Gaboury, Isabelle; Coyle, Doug; Na, Eunjung; Sallam, Nusaiba

2016-01-01

Children with mild bilateral and unilateral hearing loss are now commonly identified early through newborn hearing screening initiatives. There remains considerable uncertainty about how to support parents and about which services to provide for children with mild bilateral and unilateral hearing loss. The goal of this study was to learn about…

26 CFR 301.6231(f)-1 - Disallowance of losses and credits in certain cases.

Code of Federal Regulations, 2011 CFR

2011-04-01

... United States. (b) Computational adjustment permitted if return is not filed after mailing of notice... computational adjustment to that partner to reflect the disallowance of any loss (including a capital loss) or... computational adjustment referred to in paragraph (b) of this section may be mailed on a day on which— (1) The...

26 CFR 301.6231(f)-1 - Disallowance of losses and credits in certain cases.

Code of Federal Regulations, 2014 CFR

2014-04-01

... United States. (b) Computational adjustment permitted if return is not filed after mailing of notice... computational adjustment to that partner to reflect the disallowance of any loss (including a capital loss) or... computational adjustment referred to in paragraph (b) of this section may be mailed on a day on which— (1) The...

26 CFR 301.6231(f)-1 - Disallowance of losses and credits in certain cases.

Code of Federal Regulations, 2010 CFR

2010-04-01

... United States. (b) Computational adjustment permitted if return is not filed after mailing of notice... computational adjustment to that partner to reflect the disallowance of any loss (including a capital loss) or... computational adjustment referred to in paragraph (b) of this section may be mailed on a day on which— (1) The...

26 CFR 301.6231(f)-1 - Disallowance of losses and credits in certain cases.

Code of Federal Regulations, 2013 CFR

2013-04-01

... United States. (b) Computational adjustment permitted if return is not filed after mailing of notice... computational adjustment to that partner to reflect the disallowance of any loss (including a capital loss) or... computational adjustment referred to in paragraph (b) of this section may be mailed on a day on which— (1) The...

26 CFR 301.6231(f)-1 - Disallowance of losses and credits in certain cases.

Code of Federal Regulations, 2012 CFR

2012-04-01

... United States. (b) Computational adjustment permitted if return is not filed after mailing of notice... computational adjustment to that partner to reflect the disallowance of any loss (including a capital loss) or... computational adjustment referred to in paragraph (b) of this section may be mailed on a day on which— (1) The...

Assessing the adequacy of essential nutrient intake in obese dogs undergoing energy restriction for weight loss: a cohort study.

PubMed

German, Alexander J; Holden, Shelley L; Serisier, Samuel; Queau, Yann; Biourge, Vincent

2015-10-07

Canine obesity is usually treated with dietary energy restriction, but data are limited regarding nutritional adequacy. The aim of the current study was to compare intake of essential nutrients with National Research Council recommendations in obese dogs during weight management with a purpose-formulated diet. Twenty-seven dogs were included in this non-randomised retrospective observational cohort study. All were determined to be systemically well, and without significant abnormalities based upon physical examination and clinicopathological assessments. The dogs underwent a controlled weight loss protocol of at least 182 days' duration using a high protein high fibre weight loss diet. Median, maximum, and minimum daily intakes of all essential nutrients were compared against NRC 2006 recommended allowances (RA) for adult dogs. Median weight loss was 28 % (16-40 %), mean daily energy intake was 61 kcal/kg(0.75) (44-74 kcal/kg(0.75)), and no clinical signs of nutrient deficiency were observed in any dog. Based upon the average nutrient content of the diet, daily intake of the majority of essential nutrients was greater than their NRC 2006 recommended allowance (RA per kg body weight(0.75)), except for selenium, choline, methionine/cysteine, tryptophan, magnesium, and potassium. However, apart from choline (2/27 dogs) and methionine/cysteine (2/27 dogs), all essential nutrients remained above NRC minimum requirements (MR) throughout the trial. When fed the diet used in the current study, daily intakes of most essential nutrients meet both their NRC 2006 RA and MR in obese dogs during weight loss. In light of absence of clinical signs of nutrient deficiency, it is unclear what significance intakes less that NRC cut-offs for some nutrients have (especially selenium and choline), and further studies are recommended.

Adsorption losses from urine-based cannabinoid calibrators during routine use.

PubMed

Blanc, J A; Manneh, V A; Ernst, R; Berger, D E; de Keczer, S A; Chase, C; Centofanti, J M; DeLizza, A J

1993-08-01

The major metabolite of cannabis found in urine, 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (delta 9-THC), is the compound most often used to calibrate cannabinoid immunoassays. The hydrophobic delta 9-THC molecule is known to adsorb to solid surfaces. This loss of analyte from calibrator solutions can lead to inaccuracy in the analytical system. Because the calibrators remain stable when not used, analyte loss is most probably caused by handling techniques. In an effort to develop an effective means of overcoming adsorption losses, we quantified cannabinoid loss from calibrators during the testing process. In studying handling of these solutions, we found noticeable, significant losses attributable to both the kind of pipette used for transfer and the contact surface-to-volume ratio of calibrator solution in the analyzer cup. Losses were quantified by immunoassay and by radioactive tracer. We suggest handling techniques that can minimize adsorption of delta 9-THC to surfaces. Using the appropriate pipette and maintaining a minimum surface-to-volume ratio in the analyzer cup effectively reduces analyte loss.

On the energy efficiency of cyclic mechanisms

NASA Astrophysics Data System (ADS)

Briskin, E. S.; Kalinin, Ya. V.; Maloletov, A. V.; Chernyshev, V. V.

2014-01-01

We consider cyclic mechanisms with one degree of freedom driven by engines of various types such as alternating and direct current motors, internal combustion engines, etc. We pose the problem of modifying the mechanism structure by joining additional links or by varying the parameters or operation mode of the original mechanism so as to minimize the thermal losses in the driving motor. The solution is based on the minimization of the functional determining the irreversible power losses. We show that, for the engines considered, all cyclic mechanisms with one degree of freedom should satisfy a fundamental condition ensuring the minimum of losses. We consider two examples, one of which corresponds to actually existing mechanisms.

24 CFR 3280.507 - Comfort heat gain.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss...

42 CFR 423.2430 - Activities that improve health care quality.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 3 2014-10-01 2014-10-01 false Activities that improve health care quality. 423... Requirements for a Minimum Medical Loss Ratio § 423.2430 Activities that improve health care quality. (a... discharge planning, and post-discharge reinforcement by an appropriate health care professional. (iii) To...

42 CFR 423.2430 - Activities that improve health care quality.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 3 2013-10-01 2013-10-01 false Activities that improve health care quality. 423... Requirements for a Minimum Medical Loss Ratio § 423.2430 Activities that improve health care quality. (a... discharge planning, and post-discharge reinforcement by an appropriate health care professional. (iii) To...

42 CFR 422.2430 - Activities that improve health care quality.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 3 2013-10-01 2013-10-01 false Activities that improve health care quality. 422... Minimum Medical Loss Ratio § 422.2430 Activities that improve health care quality. (a) Activity... discharge planning, and post-discharge reinforcement by an appropriate health care professional. (iii) To...

42 CFR 422.2430 - Activities that improve health care quality.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 3 2014-10-01 2014-10-01 false Activities that improve health care quality. 422... Minimum Medical Loss Ratio § 422.2430 Activities that improve health care quality. (a) Activity... discharge planning, and post-discharge reinforcement by an appropriate health care professional. (iii) To...

14 CFR 135.93 - Autopilot: Minimum altitudes for use.

Code of Federal Regulations, 2011 CFR

2011-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight... than 500 feet or less than twice the maximum altitude loss specified in the approved Aircraft Flight...

14 CFR 135.93 - Autopilot: Minimum altitudes for use.

Code of Federal Regulations, 2012 CFR

2012-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight... than 500 feet or less than twice the maximum altitude loss specified in the approved Aircraft Flight...

14 CFR 135.93 - Autopilot: Minimum altitudes for use.

Code of Federal Regulations, 2014 CFR

2014-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight... than 500 feet or less than twice the maximum altitude loss specified in the approved Aircraft Flight...

14 CFR 135.93 - Autopilot: Minimum altitudes for use.

Code of Federal Regulations, 2013 CFR

2013-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight... than 500 feet or less than twice the maximum altitude loss specified in the approved Aircraft Flight...

14 CFR 135.93 - Autopilot: Minimum altitudes for use.

Code of Federal Regulations, 2010 CFR

2010-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight... than 500 feet or less than twice the maximum altitude loss specified in the approved Aircraft Flight...

24 CFR 3280.507 - Comfort heat gain.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss...

24 CFR 3280.507 - Comfort heat gain.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss...

24 CFR 3280.507 - Comfort heat gain.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Comfort heat gain. 3280.507 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.507 Comfort heat... part. (a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss...

Influence of light, temperature and salinity on dissolved organic carbon exudation rates in Zostera marina L.

EPA Science Inventory

Seagrass carbon budgets provide valuable insight on the minimum requirements needed to maintain this valuable resource. Carbon budgets are a balance between C fixation, storage and loss rates, most of which are well characterized. However, relatively few measurements of dissolv...

Ponderosa pine seed-tree removal reduces stocking only slightly

Treesearch

Philip M. McDonald

1969-01-01

After ponderosa pine seed trees were removed on the Challenge Experimental Forest, California, seedling stocking fell by 3.8 percent or about 212 seedlings per acre. This loss is slightly less than that incurred from natural mortality, and one that did not reduce regeneration levels below the minimum standard.

Fusarium graminearum in Stored Wheat: Use of CO2 Production to Quantify Dry Matter Losses and Relate This to Relative Risks of Zearalenone Contamination under Interacting Environmental Conditions

PubMed Central

Kiaitsi, Elsa; Magan, Naresh

2018-01-01

Zearalenone (ZEN) contamination from Fusarium graminearum colonization is particularly important in food and feed wheat, especially during post-harvest storage with legislative limits for both food and feed grain. Indicators of the relative risk from exceeding these limits would be useful. We examined the effect of different water activities (aw; 0.95–0.90) and temperature (10–25 °C) in naturally contaminated and irradiated wheat grain, both inoculated with F. graminearum and stored for 15 days on (a) respiration rate; (b) dry matter losses (DML); (c) ZEN production and (d) relationship between DML and ZEN contamination relative to the EU legislative limits. Gas Chromatography was used to measure the temporal respiration rates and the total accumulated CO2 production. There was an increase in temporal CO2 production rates in wetter and warmer conditions in all treatments, with the highest respiration in the 25 °C × 0.95 aw treatments + F. graminearum inoculation. This was reflected in the total accumulated CO2 in the treatments. The maximum DMLs were in the 0.95 aw/20–25 °C treatments and at 10 °C/0.95 aw. The DMLs were modelled to produce contour maps of the environmental conditions resulting in maximum/minimum losses. Contamination with ZEN/ZEN-related compounds were quantified. Maximum production was at 25 °C/0.95–0.93 aw and 20 °C/0.95 aw. ZEN contamination levels plotted against DMLs for all the treatments showed that at ca. <1.0% DML, there was a low risk of ZEN contamination exceeding EU legislative limits, while at >1.0% DML, the risk was high. This type of data is important in building a database for the development of a post-harvest decision support system for relative risks of different mycotoxins. PMID:29462982

Fusarium graminearum in Stored Wheat: Use of CO₂ Production to Quantify Dry Matter Losses and Relate This to Relative Risks of Zearalenone Contamination under Interacting Environmental Conditions.

PubMed

Garcia-Cela, Esther; Kiaitsi, Elsa; Sulyok, Michael; Medina, Angel; Magan, Naresh

2018-02-17

Zearalenone (ZEN) contamination from Fusarium graminearum colonization is particularly important in food and feed wheat, especially during post-harvest storage with legislative limits for both food and feed grain. Indicators of the relative risk from exceeding these limits would be useful. We examined the effect of different water activities (a w ; 0.95-0.90) and temperature (10-25 °C) in naturally contaminated and irradiated wheat grain, both inoculated with F. graminearum and stored for 15 days on (a) respiration rate; (b) dry matter losses (DML); (c) ZEN production and (d) relationship between DML and ZEN contamination relative to the EU legislative limits. Gas Chromatography was used to measure the temporal respiration rates and the total accumulated CO₂ production. There was an increase in temporal CO₂ production rates in wetter and warmer conditions in all treatments, with the highest respiration in the 25 °C × 0.95 a w treatments + F. graminearum inoculation. This was reflected in the total accumulated CO₂ in the treatments. The maximum DMLs were in the 0.95 a w /20-25 °C treatments and at 10 °C/0.95 a w . The DMLs were modelled to produce contour maps of the environmental conditions resulting in maximum/minimum losses. Contamination with ZEN/ZEN-related compounds were quantified. Maximum production was at 25 °C/0.95-0.93 a w and 20 °C/0.95 a w . ZEN contamination levels plotted against DMLs for all the treatments showed that at ca <1.0% DML, there was a low risk of ZEN contamination exceeding EU legislative limits, while at >1.0% DML, the risk was high. This type of data is important in building a database for the development of a post-harvest decision support system for relative risks of different mycotoxins.

Geometrically distributed one-dimensional photonic crystals for light-reflection in all angles.

PubMed

Alagappan, G; Wu, P

2009-07-06

We demonstrate that a series of one-dimensional photonic crystals made of any dielectric materials, with the periods are distributed in a geometrical progression of a common ratio, r < rc (theta,P), where rc is a structural parameter that depends on the angle of incidence, theta, and polarization, P, is capable of blocking light of any spectral range. If an omni-directional reflection is desired for all polarizations and for all incident angles smaller than thetao, then r < rc (theta(o),p), where p is the polarization with the electric field parallel to the plane of incidence. We present simple and formula like expressions for rc, width of the bandgap, and minimum number of photonic crystals to achieve a perfect light reflection.

The raising of minimum alcohol prices in Saskatchewan, Canada: impacts on consumption and implications for public health.

PubMed

Stockwell, Tim; Zhao, Jinhui; Giesbrecht, Norman; Macdonald, Scott; Thomas, Gerald; Wettlaufer, Ashley

2012-12-01

We report impacts on alcohol consumption following new and increased minimum alcohol prices in Saskatchewan, Canada. We conducted autoregressive integrated moving average time series analyses of alcohol sales and price data from the Saskatchewan government alcohol monopoly for 26 periods before and 26 periods after the intervention. A 10% increase in minimum prices significantly reduced consumption of beer by 10.06%, spirits by 5.87%, wine by 4.58%, and all beverages combined by 8.43%. Consumption of coolers decreased significantly by 13.2%, cocktails by 21.3%, and liqueurs by 5.3%. There were larger effects for purely off-premise sales (e.g., liquor stores) than for primarily on-premise sales (e.g., bars, restaurants). Consumption of higher strength beer and wine declined the most. A 10% increase in minimum price was associated with a 22.0% decrease in consumption of higher strength beer (> 6.5% alcohol/volume) versus 8.17% for lower strength beers. The neighboring province of Alberta showed no change in per capita alcohol consumption before and after the intervention. Minimum pricing is a promising strategy for reducing the public health burden associated with hazardous alcohol consumption. Pricing to reflect percentage alcohol content of drinks can shift consumption toward lower alcohol content beverage types.

Sunspot Activity Near Cycle Minimum and What it Might Suggest for Cycle 24, the Next Sunspot Cycle

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.

2009-01-01

In late 2008, 12-month moving averages of sunspot number, number of spotless days, number of groups, area of sunspots, and area per group were reflective of sunspot cycle minimum conditions for cycle 24, these values being of or near record value. The first spotless day occurred in January 2004 and the first new-cycle, high-latitude spot was reported in January 2008, although old-cycle, low-latitude spots have continued to be seen through April 2009, yielding an overlap of old and new cycle spots of at least 16 mo. New-cycle spots first became dominant over old-cycle spots in September 2008. The minimum value of the weighted mean latitude of sunspots occurred in May 2007, measuring 6.6 deg, and the minimum value of the highest-latitude spot followed in June 2007, measuring 11.7 deg. A cycle length of at least 150 mo is inferred for cycle 23, making it the longest cycle of the modern era. Based on both the maximum-minimum and amplitude-period relationships, cycle 24 is expected to be only of average to below-average size, peaking probably in late 2012 to early 2013, unless it proves to be a statistical outlier.

A 30-GHz monolithic receiver

NASA Technical Reports Server (NTRS)

Liu, Louis C. T.; Liu, Carol S.; Kessler, Joel R.; Wang, Shing-Kuo; Chang, Ching-Der

1986-01-01

Several monolithic integrated circuits have been developed to make a 30-GHz receiver. The receiver components include a low-noise amplifier (LNA), an IF amplifier, a mixer, and a phase shifter. The LNA has a 7-dB noise figure with over 17 dB of associated gain. The IF amplifier has a 13-dB gain with a 30-dB control range. The mixer has a conversion loss of 10.5 dB. The phase shifter has a 180-deg phase shift control and a minimum insertion loss of 1.6 dB.

Analysis of loss of time value during road maintenance project

NASA Astrophysics Data System (ADS)

Sudarsana, Dewa Ketut; Sanjaya, Putu Ari

2017-06-01

Lane closure is frequently performed in the execution of the road maintenance project. It has a negative impact on road users such as the loss of vehicle operating costs and the loss of time value. Nevertheless, analysis on loss of time value in Indonesia has not been carried out. The parameter of time value for the road users was the minimum wage city/region approach. Vehicle speed of pre-construction was obtained by observation, while the speed during the road maintenance project was predicted by the speed of the pre-construction by multiplying it with the speed adjustment factor. In the case of execution of the National road maintenance project in the two-lane two-way urban and interurban road types in the fiscal year of 2015 in Bali province, the loss of time value was at the average of IDR 12,789,000/day/link road. The relationship of traffic volume and loss of time value of the road users was obtained by a logarithm model.

Antarctic ozone loss in 1989-2010: evidence for ozone recovery?

NASA Astrophysics Data System (ADS)

Kuttippurath, J.; Lefèvre, F.; Pommereau, J.-P.; Roscoe, H. K.; Goutail, F.; Pazmiño, A.; Shanklin, J. D.

2012-04-01

We present a detailed estimation of chemical ozone loss in the Antarctic polar vortex from 1989 to 2010. The analyses include ozone loss estimates for 12 Antarctic ground-based (GB) stations. All GB observations show minimum ozone in the late September-early October period. Among the stations, the lowest minimum ozone values are observed at South Pole and the highest at Dumont d'Urville. The ozone loss starts by mid-June at the vortex edge and then progresses towards the vortex core with time. The loss intensifies in August-September, peaks by the end of September-early October, and recovers thereafter. The average ozone loss in the Antarctic is revealed to be about 33-50% in 1989-1992 in agreement with the increase in halogens during this period, and then stayed at around 48% due to saturation of the loss. The ozone loss in the warmer winters (e.g. 2002, and 2004) is lower (37-46%) and in the colder winters (e.g. 2003, and 2006) is higher (52-55%). Because of small inter-annual variability, the correlation between ozone loss and the volume of polar stratospheric clouds yields ~0.51. The GB ozone and ozone loss values are in good agreement with those found from the space-based observations of the Total Ozone Mapping Spectrometer/Ozone Monitoring Instrument (TOMS/OMI), the Global Ozone Monitoring Experiment (GOME), the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and the Aura Microwave Limb Sounder (MLS), where the differences are within ±5% and are mostly within the error bars of the measurements. The piece-wise linear trends computed from the September-November vortex average GB and TOMS/OMI ozone show about -4 to -5.6 DU (Dobson Unit) yr-1 in 1989-1996 and about +1 DU yr-1 in 1997-2010. The trend during the former period is significant at 95% confidence intervals, but the trend in 1997-2010 is significant only at 85% confidence intervals. Our analyses suggest a period of about 9-10 yr to get the first detectable ozone recovery signal at the 95% confidence intervals with the current ozone trends in the Antarctic. Thus, this study reveals that the recovery of the Antarctic ozone is well on course.

A Shack Interferometer Setup for Optical Testing in Undergraduate Courses

ERIC Educational Resources Information Center

Vannoni, Maurizio; Righini, Alberto; Salas, Matias; Sordini, Andrea; Vanzi, Leonardo

2012-01-01

The Shack interferometer is a simple and effective device to test optical surfaces in reflection and optical systems in transmission. An essential setup on a reduced scale with a minimum number of components is presented, suited to gain familiarity and practice with optical testing in a laboratory course for undergraduate students. The basic…

Five Steps for Improving Evaluation Reports by Using Different Data Analysis Methods.

ERIC Educational Resources Information Center

Thompson, Bruce

Although methodological integrity is not the sole determinant of the value of a program evaluation, decision-makers do have a right, at a minimum, to be able to expect competent work from evaluators. This paper explores five areas where evaluators might improve methodological practices. First, evaluation reports should reflect the limited…

12 CFR 226.6 - Account-opening disclosures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... compute the finance charge, the range of balances to which it is applicable,11 and the corresponding... required to adjust the range of balances disclosure to reflect the balance below which only a minimum... balance on which the finance charge may be computed. (iv) An explanation of how the amount of any finance...

76 FR 37655 - Combined Mailings of Standard Mail and Periodicals Flats

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

... Periodicals flats to be made using a minimum of six (6) pieces, as is currently permitted for Periodicals... Regulations to reflect that the Standard Mail service standards apply to all Periodicals flats pieces entered... for Standard Mail of 200 pieces or 50 pounds. Periodicals publications must be authorized or have a...

MASSIVE LEAKAGE IRRADIATOR

DOEpatents

Wigner, E.P.; Szilard, L.; Christy, R.F.; Friedman, F.L.

1961-05-30

An irradiator designed to utilize the neutrons that leak out of a reactor around its periphery is described. It avoids wasting neutron energy and reduces interference with the core flux to a minimum. This is done by surrounding all or most of the core with removable segments of the material to be irradiated within a matrix of reflecting material.

36 CFR 222.54 - Grazing fees in the East-competitive bidding.

Code of Federal Regulations, 2010 CFR

2010-07-01

... permit to be issued, as well as document existing improvements and their condition. The prospectus shall...; (ii) The minimum bid price the agency will accept; (iii) Any required range improvements; and (iv) The... improvements. This hay price index shall be based on 3-year average hay prices and annually reflect the percent...

36 CFR 222.54 - Grazing fees in the East-competitive bidding.

Code of Federal Regulations, 2011 CFR

2011-07-01

... permit to be issued, as well as document existing improvements and their condition. The prospectus shall...; (ii) The minimum bid price the agency will accept; (iii) Any required range improvements; and (iv) The... improvements. This hay price index shall be based on 3-year average hay prices and annually reflect the percent...

International WIL Placements: Their Influence on Student Professional Development, Personal Growth and Cultural Competence

ERIC Educational Resources Information Center

Gribble, Nigel; Dender, Alma; Lawrence, Emma; Manning, Kirrily; Falkmer, Torbjorn

2014-01-01

In the increasingly global world, skills in cultural competence now form part of the minimum standards of practice required for allied health professionals. During an international work-integrated learning (WIL) placement, allied health students' cultural competence is expected to be enhanced. The present study scrutinized reflective journals of…

Solving portfolio selection problems with minimum transaction lots based on conditional-value-at-risk

NASA Astrophysics Data System (ADS)

Setiawan, E. P.; Rosadi, D.

2017-01-01

Portfolio selection problems conventionally means ‘minimizing the risk, given the certain level of returns’ from some financial assets. This problem is frequently solved with quadratic or linear programming methods, depending on the risk measure that used in the objective function. However, the solutions obtained by these method are in real numbers, which may give some problem in real application because each asset usually has its minimum transaction lots. In the classical approach considering minimum transaction lots were developed based on linear Mean Absolute Deviation (MAD), variance (like Markowitz’s model), and semi-variance as risk measure. In this paper we investigated the portfolio selection methods with minimum transaction lots with conditional value at risk (CVaR) as risk measure. The mean-CVaR methodology only involves the part of the tail of the distribution that contributed to high losses. This approach looks better when we work with non-symmetric return probability distribution. Solution of this method can be found with Genetic Algorithm (GA) methods. We provide real examples using stocks from Indonesia stocks market.

Spatial and Temporal Means and Variability of Arctic Sea Ice Climate Indicators from Satellite Data

NASA Astrophysics Data System (ADS)

Peng, G.; Meier, W.; Bliss, A. C.; Steele, M.; Dickinson, S.

2017-12-01

Arctic sea ice has been undergoing rapid and accelerated loss since satellite-based measurements became available in late 1970s, especially the summer ice coverage. For the Arctic as a whole, the long-term trend for the annual sea ice extent (SIE) minimum is about -13.5±2.93 % per decade change relative to the 1979-2015 climate average, while the trends of the annual SIE minimum for the local regions can range from 0 to up to -42 % per decade. This presentation aims to examine and baseline spatial and temporal means and variability of Arctic sea ice climate indicators, such as the annual SIE minimum and maximum, snow/ice melt onset, etc., from a consistent, inter-calibrated, long-term time series of remote sensing sea ice data for understanding regional vulnerability and monitoring ice state for climate adaptation and risk mitigation.

Interfaces in Si/Ge atomic layer superlattices on (001)Si: Effect of growth temperature and wafer misorientation

NASA Astrophysics Data System (ADS)

Baribeau, J.-M.; Lockwood, D. J.; Syme, R. W. G.

1996-08-01

We have used x-ray diffraction, specular reflectivity, and diffuse scattering, complemented by Raman spectroscopy, to study the interfaces in a series of (0.5 nm Ge/2 nm Si)50 atomic layer superlattices on (001)Si grown by molecular beam epitaxy in the temperature range 150-650 °C. X-ray specular reflectivity revealed that the structures have a well-defined periodicity with interface widths of about 0.2-0.3 nm in the 300-590 °C temperature range. Offset reflectivity scans showed that the diffuse scattering peaks at values of perpendicular wave vector transfer corresponding to the superlattice satellite peaks, indicating that the interfaces are vertically correlated. Transverse rocking scans of satellite peaks showed a diffuse component corresponding to an interface corrugation of typical length scale of ˜0.5 μm. The wavelength of the undulations is a minimum along the miscut direction and is typically 30-40 times larger than the surface average terrace width assuming monolayer steps, independently of the magnitude of the wafer misorientation. The amplitude of the undulation evolves with growth temperature and is minimum for growth at ˜460 °C and peaks at ˜520 °C. Raman scattering showed the chemical abruptness of the interfaces at low growth temperatures and indicated a change in the growth mode near 450 °C.

Hydrothermal synthesis of carbonyl iron-carbon nanocomposite: Characterization and electromagnetic performance

NASA Astrophysics Data System (ADS)

Pourabdollahi, Hakimeh; Zarei, Ali Reza

In this research, the electromagnetic absorption properties of the carbonyl iron-carbon (CI/C) nanocomposite prepared via hydrothermal reaction using glucose as carbon precursor was studied in the range of 8.2-12.4 GHz. In hydrothermal reaction, glucose solution containing CI particles, placed in autoclave for 4 h under 453 K. Using surface coating technology is a method that prevents Cl oxidation and improves CI electromagnetic absorption. The structure, morphology and magnetic performances of the prepared nanocomposites were characterized by X-ray diffraction (XRD), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The electromagnetic properties including complex permittivity (εr), the permeability (μr), dielectric loss, magnetic loss, reflection loss, and attenuation constant were investigated using a vector network analyzer. For The CI/C nanocomposite, the bandwidth of -10 dB and -20 dB were obtained in the frequency range of 9.8-12.4 and 11.0-11.8 GHz, respectively. As well as, the reflection loss was -46.69 dB at the matching frequency of 11.5 GHz, when the matching thickness was 1.3 mm. While for CI particles the reflection loss for 4.4 mm thickness was -16.86 dB at the matching frequency of 12.3 GHz. The results indicate that the existence layer of carbon on carbonyl iron enhance the electromagnetic absorbing properties. Therefore, this nanocomposite can be suitable for in the radar absorbing coatings.

Absorption and Modification of Lower Hybrid Waves in the Scrape Off Layer

NASA Astrophysics Data System (ADS)

Parker, R.; Wallace, G.; Shiraiwa, S.; Baek, S.-G.; Faust, I.

2015-11-01

Loss of current drive efficiency of lower hybrid waves at high density in Alcator C-Mod current drive experiments has been attributed, at least in part, to interactions in the SOL. While ray-tracing calculations indicate that collisional absorption and modification of n|| during reflections in the SOL can be significant, their validity can be called into question owing to steep SOL gradients. In order to further quantify these losses, full-wave calculations using a plane-stratified SOL model have been carried out. The results show that the loss resulting from reflections in the SOL can be substantial, with collisional losses accounting for a loss of up to 50% per bounce of the incident wave power. The loss is sensitive to the SOL parameters with the strongest collisional absorption occurring in the case of steep temperature and weak density gradients. Modification of n|| can also be significant when the density gradient and normal to the flux surfaces are not aligned. These effects are less severe for the fast wave since its penetration into the SOL is significantly less than that of the slow wave. Work supported by USDoE awards DE-FC02-99ER54512 and DE-AC02-09CH11466.

Standardization of Solar Mirror Reflectance Measurements - Round Robin Test: Preprint

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

Meyen, S.; Lupfert, E.; Fernandez-Garcia, A.

2010-10-01

Within the SolarPaces Task III standardization activities, DLR, CIEMAT, and NREL have concentrated on optimizing the procedure to measure the reflectance of solar mirrors. From this work, the laboratories have developed a clear definition of the method and requirements needed of commercial instruments for reliable reflectance results. A round robin test was performed between the three laboratories with samples that represent all of the commercial solar mirrors currently available for concentrating solar power (CSP) applications. The results show surprisingly large differences in hemispherical reflectance (sh) of 0.007 and specular reflectance (ss) of 0.004 between the laboratories. These differences indicate themore » importance of minimum instrument requirements and standardized procedures. Based on these results, the optimal procedure will be formulated and validated with a new round robin test in which a better accuracy is expected. Improved instruments and reference standards are needed to reach the necessary accuracy for cost and efficiency calculations.« less

Neurodegenerative Models in Drosophila: Polyglutamine Disorders, Parkinson Disease, and Amyotrophic Lateral Sclerosis

PubMed Central

Ambegaokar, Surendra S.; Roy, Bidisha; Jackson, George R.

2010-01-01

Neurodegenerative diseases encompass a large group of neurological disorders. Clinical symptoms can include memory loss, cognitive impairment, loss of movement or loss of control of movement, and loss of sensation. Symptoms are typically adult onset (although severe cases can occur in adolescents) and are reflective of neuronal and glial cell loss in the central nervous system. Neurodegenerative diseases also are considered progressive, with increased severity of symptoms over time, also reflective of increased neuronal cell death. However, various neurodegenerative diseases differentially affect certain brain regions or neuronal or glial cell types. As an example, Alzheimer disease (AD) primarily affects the temporal lobe, whereas neuronal loss in Parkinson disease (PD) is largely (although not exclusively) confined to the nigrostriatal system. Neuronal loss is almost invariably accompanied by abnormal insoluble aggregates, either intra- or extracellular. Thus, neurodegenerative diseases are categorized by (a) the composite of clinical symptoms, (b) the brain regions or types of brain cells primarily affected, and (c) the types of protein aggregates found in the brain. Here we review the methods by which Drosophila melanogaster has been used to model aspects of polyglutamine diseases, Parkinson disease, and amyotrophic lateral sclerosis and key insights into that have been gained from these models; Alzheimer disease and the tauopathies are covered elsewhere in this special issue. PMID:20561920

Surface-plasmon polariton scattering from a finite array of nanogrooves/ridges: Efficient mirrors

NASA Astrophysics Data System (ADS)

Sánchez-Gil, José A.; Maradudin, Alexei A.

2005-06-01

The scattering of surface-plasmon polaritons (SPP) by finite arrays of one-dimensional nanodefects on metal surfaces is theoretically investigated on the basis of the reduced Rayleigh equation. Numerical calculations are carried out that rigorously account for all the scattering channels: SPP reflection and transmission, and radiative leakage. We analyze the range of parameters (defect size and number) for which high SPP reflection efficiency (low radiative losses) is achieved within a SPP band gap (negligible SPP transmission), neglecting ohmic losses (justified for array lengths significantly shorter than the SPP inelastic length): Smaller defects play better as SPP mirrors (e.g., efficiency >90% at λ ˜650nm for Gaussian ridges/grooves with sub-30nm height and half-width) than larger defects, since the latter yield significant radiative losses.

Measurement of the properties of lossy materials inside a finite conducting cylinder

NASA Technical Reports Server (NTRS)

Dominek, A.; Park, A.; Caldecott, R.

1988-01-01

Broadband, swept frequency measurement techniques were investigated for the evaluation of the electrical performance of thin, high temperature material coatings. Reflections and transmission measurements using an HP8510B Network Analyzer were developed for an existing high temperature test rig at NASA Lewis Research Center. Reflection measurements will be the initial approach used due to fixture simplicity even though surface wave transmission measurements would be more sensitive. The minimum goal is to monitor the electrical change of the material's performance as a function of temperature. If possible, the materials constitutive parameters, epsilon and muon will be found.

Data acquisition of neutron crystallography on tetragonal and triclinic forms of hen-egg-white (HEW) lysozyme with an elastically bent Si monochromator

NASA Astrophysics Data System (ADS)

Tanaka, I.; Minezaki, Y.; Harada, K.; Niimura, N.

An elastically bent silicon (EBSi) as a monochromator has been optimized for neutron diffractometers of biocrystallography. It was found that several stacked thin Si plates were easier to be bent much for the near focusing point and they increased neutron reflectivity by aligning the plates. Currently, an EBSi(1 1 1) monochromator system was equipped at a diffractometer (BIX-I). It took 50 days to collect about 12 000 reflections of hen-egg-white lysozyme. The minimum d-spacing was 2.1 Å.

Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations

NASA Technical Reports Server (NTRS)

Woronowicz, Michael

2011-01-01

We have learned it is conceivable that the Neutral Mass Spectrometer on board the Lunarr Atmosphere Dust Environment Explorer (LADEE) could measure gases from surface-reflected Attitude Control System (ACS) thruster plume. At minimum altitude, the measurement would be maximized, and gravitational influence minimized ("short" time-of-flight (TOF) situation) Could use to verify aspects of thruster plume modeling Model the transient disturbance to NMS measurements due to ACS gases reflected from lunar surface Observe evolution of various model characteristics as measured by NMS Species magnitudes, TOF measurements, angular distribution, species separation effects

Bifacial solar cell measurements under standard test conditions and the impact on cell-to-module loss analysis

NASA Astrophysics Data System (ADS)

Singh, Jai Prakash; Chai, Jing; Hsian Saw, Min; Khoo, Yong Sheng

2017-08-01

Bifacial cells are conventionally measured using gold-plated chuck, which is conductive and reflective. This measurement setup does not portray the actual operating conditions of the bifacial cells in a module. The reflective chuck causes an overestimation of the current due to the cell transmittance for the infrared light. The conductive chuck creates a shorter current flow path in the rear side of the cell and causes an over inflation of the fill factor measurement. In this study, we characterize and quantitatively analyze the difference between the bifacial cell measurements on different mounting chucks and calculate the cell-to-module (CTM) loss. To characterize the optical behavior of the bifacial cell and module, we perform external quantum efficiency, reflectance and transmittance measurements. The electrical behavior of the bifacial cell is studied using in-house developed software Griddler. Using Griddler, we calculate the difference in the fill factor of the bifacial cell due to the measurement using a conductive and non-conductive chuck, and estimate the corresponding CTM resistive losses.

Dynamic Determination of Some Optical and Electrical Properties of Galena Natural Mineral: Potassium Ethyl Xanthate Solution Interface

NASA Astrophysics Data System (ADS)

Todoran, D.; Todoran, R.; Anitas, E. M.; Szakacs, Zs.

2017-12-01

This paper presents results concerning optical and electrical properties of galena natural mineral and of the interface layer formed between it and the potassium ethyl xanthate solution. The applied experimental method was differential optical reflectance spectroscopy over the UV-Vis/NIR spectral domain. Computations were made using the Kramers-Kronig formalism. Spectral dependencies of the electron loss functions, determined from the reflectance data obtained from the polished mineral surface, display van Hove singularities, leading to the determination of its valence band gap and electron plasma energy. Time dependent measurement of the spectral dispersion of the relative reflectance of the film formed at the interface, using the same computational formalism, leads to the dynamical determination of the spectral variation of its optical and electrical properties. We computed behaviors of the dielectric constant (dielectric permittivity), the dielectric loss function, refractive index and extinction coefficient, effective valence number and of the electron loss functions. The measurements tend to stabilize when the dynamic adsorption-desorption equilibrium is reached at the interface level.

Nano-cones for broadband light coupling to high index substrates

NASA Astrophysics Data System (ADS)

Buencuerpo, J.; Torné, L.; Álvaro, R.; Llorens, J. M.; Dotor, M. L.; Ripalda, J. M.

2016-12-01

The moth-eye structure has been proposed several times as an antireflective coating to replace the standard optical thin films. Here, we experimentally demonstrate the feasibility of a dielectric moth-eye structure as an antireflective coating for high-index substrates, like GaAs. The fabricated photonic crystal has Si3N4 cones in a square lattice, sitting on top of a TiO2 index matching layer. This structure attains 1.4% of reflectance power losses in the operation spectral range of GaAs solar cells (440-870 nm), a 12.5% relative reduction of reflection power losses in comparison with a standard bilayer. The work presented here considers a fabrication process based on laser interference lithography and dry etching, which are compatible with solar cell devices. The experimental results are consistent with scattering matrix simulations of the fabricated structures. In a broader spectral range (400-1800 nm), the simulation estimates that the nanostructure also significantly outperforms the standard bilayer coating (3.1% vs. 4.5% reflection losses), a result of interest for multijunction tandem solar cells.

Adjustable Optical-Fiber Attenuator

NASA Technical Reports Server (NTRS)

Buzzetti, Mike F.

1994-01-01

Adjustable fiber-optic attenuator utilizes bending loss to reduce strength of light transmitted along it. Attenuator functions without introducing measurable back-reflection or insertion loss. Relatively insensitive to vibration and changes in temperature. Potential applications include cable television, telephone networks, other signal-distribution networks, and laboratory instrumentation.

TASK 2.5.5 NATURAL EXPOSURE TESTING IN CALIFORNIA

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

Miller, William A; Cheng, Mengdawn; New, Joshua Ryan

2010-03-01

Airborne particulate matter that settles on a roof can either reflect or absorb incoming solar radiation, dependent on the chemical content and size of the particles. These light scattering and absorption processes occur within a few microns of the surface, and can affect the solar reflectance of the roof. Wilkes et al. (2000) tested 24 different roof coatings on a low-slope test stand and observed about a 25% decrease in the solar reflectance of white-coated and aluminum-coated surfaces as the time of exposure increased; however, the decrease leveled off after 2 years. SPRI Inc. and its affiliates studied the effectmore » of climatic exposure on the surface properties of white thermoplastic single-ply membranes and determined that membranes lose from 30 to 50% of their reflectance over 3 years (Miller et al. 2002). The CMRC and its affiliates AISI, NamZAC, MBMA, MCA and NCCA exposed unpainted and painted metal roofing on both steep- and low-slope test roofs and found that after 3 years, the painted polyvinylidene fluoride (PVDF) metal roofs lost less than 5% of their original reflectance (Miller et al. 2004). The results of the three different weathering studies are very interesting in terms of their solar reflectance after 3 years of exposure. The white thermoplastic membrane and white ceramic coating with white topcoat had original reflectance measures that were about 20 percentage points higher than the painted metal; however, after 3-years of field exposure the solar reflectance of the painted metal exceeds that of the thermoplastic membrane and equals that of the coating. The long-term loss of reflectance appears driven by the ability of the particulate matter to cling to the roof and resist being washed off by wind and or rain. Miller et al. (2002) discovered that aerosol deposition introduced biomass of complex microbial consortia onto the test roofs and the combination of contaminants and biomass accelerated the loss of solar reflectance for the thermoplastic membranes and the roof coatings. Airborne contaminants and biomass were also detected on the painted metal roofs; however, the loss of solar reflectance was less than 5% for the painted metal roofs. The chemistry of the PVDF paint resin system uses similar organic film bonding to that responsible for Teflon , making it extremely chemical resistant and dirt shedding. Miller and Rudolph (2003) found the PVDF painted metals maintained solar reflectance even after 30 years of climatic exposure. Therefore the reduction of roof reflectance is closely related to the composition of the roof and to the chemical profile of the contaminants soiling the roof. Contaminants collected from samples of roof products exposed at seven California weathering sites were analyzed for elements and carbons to characterize the chemical profile of the particles soiling each roof sample and to identify those elements that degrade or enhance solar reflectance. The losses in solar reflectance varied from site to site and also varied at a give site based on the color of the coupon. The least drop in reflectance was observed in the alpine climate of McArthur while the largest drop occurred in sites near urban development. Light color samples were soiled after just one year of exposure. The darker color coupons did not show the same seasonal variations in solar reflectance as observed for the lighter colors. However, after an additional year of exposure the samples at all sites regained most of their solar reflectance due to rain and/or wind washing. The loss of reflectance appears cyclical with the onset of seasons having more rainfall. Solar reflectance of the cool pigmented coupons always exceeded that of the conventional pigmented coupons. Climatic soiling did not cause the cool pigmented roof coupons to lose any more solar reflectance than their conventional pigmented counterparts. The effect of roof slope appears to have more of an effect on lighter color roofs whose solar reflectance exceeds at least 0.5 and visually shows the accumulation of airborne contaminants. The thermal emittance remained invariant with time and location and was therefore not affected by climatic soiling. A thin-film deposition model was developed based on first principles, which simulates light interaction with a soiled substrate. This model was used in combination with the measured data to determine the solar absorptance and reflectance of particulate matter at each of the sites calculated using least squares fitting routines. Principal Component Analysis was used to determine the most important combinations of chemicals correlated with changes in solar absorption. Linear regression helped extract an approximate correlation using chromium, iron and elemental carbon concentrations. It appears that chromium ranks first, iron ranks second, and elemental carbon ranks third in importance to soil absorptance in the data« less

X-Ray Laser

DTIC Science & Technology

1991-01-31

Reflection in Relativistic Electron Beam Channel Radiation Systems, IEEE Trans. on Plasma Science 16(5), 548 (1988). 3. M. Strauss, P. Amendt, N...Reduced Radiation Losses in a Channeled-Beam X-Ray Laser by Bragg Reflection Coupling, Phys. Rev. A 39(11), 5791 (1989). 6. M. Strauss and N. Rostoker... Radiation Guiding in Channeling Beam X-Ray Laser by Bragg Reflection Coupling, Phys. Rev. A 40(12), 7097 (1989). 91-00870111 llllltl

Preparation and electromagnetic wave absorption of RGO/Cu nanocomposite

NASA Astrophysics Data System (ADS)

Zhang, Hui; Tian, Xingyou; Zhang, Xian; Li, Shikuo; Shen, Yuhua; Xie, Anjian

2017-09-01

We use a facile pyrolysis method to prepare reduced graphene oxide and copper nanocomposite (RGO/Cu) based on it. The product shows an outstanding wave absorption properties. The maximum reflection loss is up to-50.7 dB at 3.8 GHz. The reflection loss of-10 dB (90% power absorption) corresponds to a bandwidth of 11.2 GHz (3.4-14.6 GHz range) for the layer thickness of 2-5 mm. Therefore, it is suggested that the RGO/Cu nanocomposite is also a new kind of lightweight and high-performance EM wave absorbing material.

7 CFR 457.112 - Hybrid sorghum seed crop insurance provisions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... seed test. Insurable interest. Your share of the financial loss that occurs in the event seed... by the price election you select and subtracting any minimum guaranteed payment, not to exceed the... value to dollars by multiplying it by the price election you selected. Approved yield. In lieu of the...

14 CFR 125.329 - Minimum altitudes for use of autopilot.

Code of Federal Regulations, 2014 CFR

2014-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations... than 500 feet or less than twice the maximum altitude loss specified in the approved Airplane Flight...

14 CFR 125.329 - Minimum altitudes for use of autopilot.

Code of Federal Regulations, 2012 CFR

2012-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations... than 500 feet or less than twice the maximum altitude loss specified in the approved Airplane Flight...

14 CFR 125.329 - Minimum altitudes for use of autopilot.

Code of Federal Regulations, 2013 CFR

2013-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations... than 500 feet or less than twice the maximum altitude loss specified in the approved Airplane Flight...

14 CFR 125.329 - Minimum altitudes for use of autopilot.

Code of Federal Regulations, 2011 CFR

2011-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations... than 500 feet or less than twice the maximum altitude loss specified in the approved Airplane Flight...

14 CFR 125.329 - Minimum altitudes for use of autopilot.

Code of Federal Regulations, 2010 CFR

2010-01-01

... specifications to allow the use, to touchdown, of an approved flight control guidance system with automatic... CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations... than 500 feet or less than twice the maximum altitude loss specified in the approved Airplane Flight...

30 CFR 717.18 - Dams constructed of or impounding waste material.

Code of Federal Regulations, 2012 CFR

2012-07-01

... at least 3 feet to avoid overtopping by wind and wave action. (iii) Dams shall have minimum safety... pressures, internal erosion, sloughing, removal of material by solution, or erosion of material by loss into... regulatory authority before construction begins. (8) All dams shall be removed and the disturbed areas...

30 CFR 717.18 - Dams constructed of or impounding waste material.

Code of Federal Regulations, 2014 CFR

2014-07-01

... at least 3 feet to avoid overtopping by wind and wave action. (iii) Dams shall have minimum safety... pressures, internal erosion, sloughing, removal of material by solution, or erosion of material by loss into... regulatory authority before construction begins. (8) All dams shall be removed and the disturbed areas...

30 CFR 717.18 - Dams constructed of or impounding waste material.

Code of Federal Regulations, 2013 CFR

2013-07-01

... at least 3 feet to avoid overtopping by wind and wave action. (iii) Dams shall have minimum safety... pressures, internal erosion, sloughing, removal of material by solution, or erosion of material by loss into... regulatory authority before construction begins. (8) All dams shall be removed and the disturbed areas...

The Steiner Multigraph Problem: Wildlife corridor design for multiple species

Treesearch

Katherine J. Lai; Carla P. Gomes; Michael K. Schwartz; Kevin S. McKelvey; David E. Calkin; Claire A. Montgomery

2011-01-01

The conservation of wildlife corridors between existing habitat preserves is important for combating the effects of habitat loss and fragmentation facing species of concern. We introduce the Steiner Multigraph Problem to model the problem of minimum-cost wildlife corridor design for multiple species with different landscape requirements. This problem can also model...

75 FR 1670 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-12

... NYSE Amex Equities Rule 18 (``Compensation in Relation to Exchange System Failure'') to eliminate the..., the Commission's Public Reference Room, the Commission's Web site at http://www.sec.gov , and the... (``Compensation in Relation to Exchange System Failure'') to eliminate the $500 minimum net loss requirement for a...

14 CFR 205.5 - Minimum coverage.

Code of Federal Regulations, 2011 CFR

2011-01-01

... commuter air carriers but excluding U.S. air taxi operators and Canadian charter air taxi operators, shall...,000 times 75 percent of the number of passenger seats installed in the aircraft. (c) U.S. air taxi... each occurrence for loss of or damage to property. (2) U.S. air taxi operators carrying passengers in...

14 CFR 205.5 - Minimum coverage.

Code of Federal Regulations, 2010 CFR

2010-01-01

... commuter air carriers but excluding U.S. air taxi operators and Canadian charter air taxi operators, shall...,000 times 75 percent of the number of passenger seats installed in the aircraft. (c) U.S. air taxi... each occurrence for loss of or damage to property. (2) U.S. air taxi operators carrying passengers in...

Tinnitus pitch and minimum masking levels in different etiologies.

PubMed

Zagólski, Olaf; Stręk, Paweł

2014-07-01

We sought to determine whether the results of audiological tests and tinnitus characteristics, particularly tinnitus pitch and minimum masking level (MML), depend on tinnitus etiology, and what other etiology-specific tinnitus characteristics there are. The patients answered questions concerning tinnitus laterality, duration, character, aggravation, alleviation, previous treatment, and circumstances of onset. The results of tympanometry, pure-tone audiometry, distortion-product otoacoustic emissions, tinnitus likeness spectrum, MML, and uncomfortable loudness level were evaluated. Patients with several tinnitus etiological factors were excluded. The remaining participants were divided into groups according to medical history: acute acoustic trauma: 67 ears; chronic acoustic trauma: 82; prolonged use of oral estrogen and progesterone contraceptives: 46; Ménière's disease: 25; congenital hearing loss: 19; sensorineural sudden deafness: 40; dull head trauma: 19; viral labyrinthitis: 53; stroke: 6; presbycusis: 152. Data of 509 ears were analysed. Tinnitus pitch was highest in patients with acute acoustic trauma and lowest in patients receiving estrogen and progesterone. MML was lowest after acute acoustic trauma and in congenital hearing loss, and highest after a stroke and in the case of presbytinnitus. Tinnitus pitch and MML are etiology dependent.

Expansion of oxygen minimum zones may reduce available habitat for tropical pelagic fishes

NASA Astrophysics Data System (ADS)

Stramma, Lothar; Prince, Eric D.; Schmidtko, Sunke; Luo, Jiangang; Hoolihan, John P.; Visbeck, Martin; Wallace, Douglas W. R.; Brandt, Peter; Körtzinger, Arne

2012-01-01

Climate model predictions and observations reveal regional declines in oceanic dissolved oxygen, which are probably influenced by global warming. Studies indicate ongoing dissolved oxygen depletion and vertical expansion of the oxygen minimum zone (OMZ) in the tropical northeast Atlantic Ocean. OMZ shoaling may restrict the usable habitat of billfishes and tunas to a narrow surface layer. We report a decrease in the upper ocean layer exceeding 3.5mll-1 dissolved oxygen at a rate of <=1myr-1 in the tropical northeast Atlantic (0-25°N, 12-30°W), amounting to an annual habitat loss of ~5.95×1013m3, or 15% for the period 1960-2010. Habitat compression and associated potential habitat loss was validated using electronic tagging data from 47 blue marlin. This phenomenon increases vulnerability to surface fishing gear for billfishes and tunas, and may be associated with a 10-50% worldwide decline of pelagic predator diversity. Further expansion of the Atlantic OMZ along with overfishing may threaten the sustainability of these valuable pelagic fisheries and marine ecosystems.

On the water transport of animals with special reference to Denmark.

PubMed

Katić, Ivan; Bajt, Vesna Vucevac

2009-01-01

Transport of animals by water is a very old way of transport because it is relatively cheap and safe, with a minimum loss of animals. Waterways have been used for the transport of living animals and various goods from ancient times, for example in Ancient Egypt and the Roman Empire. Later, Vikings were so successful in their conquests because they always had trained horses aboard. It is believed that the colonization of America was possible because Spaniards were also bringing many horses with them. Danish possessions in the Caribbean owe much of their economic success in the period between 1820 and 1920 to permanent supply of cheap mules and other equides from South America. Mules were used for agricultural purposes and for work in sugar-cane mills. In the 20th century, a significant number of animals was transported to German and British colonies in South Africa. During the First and the Second World War, animals were also transported by water; measures were taken to meet the fundamental physiological requirements, and a veterinarian accompanied animals on long voyages. These precautions resulted in minimum transport losses.

Hands-on work fine-tunes X-band PIN-diode duplexer

NASA Astrophysics Data System (ADS)

Schneider, P.

1985-06-01

Computer-aided design (CAD) programs for fabricating PIN-diode duplexers are useful in avoiding time-consuming cut-and-try techniques. Nevertheless, to attain minimum insertion loss, only experimentation yields the optimum microstrip circuitry. A PIN-diode duplexer, consisting of two SPST PIN-diode switches and a pair of 3-dB Lange microstrip couplers, designed for an X-band transmit/receive module exemplifies what is possible when computer-derived designs and experimentation are used together. Differences between the measured and computer-generated figures for insertion loss can be attributed to several factors not included in the CAD program - for example, radiation and connector losses. Mechanical tolerances of the microstrip PC board and variations in the SMA connector-to-microstrip transition contribute to the discrepancy.

Piloted Simulation of a Model-Predictive Automated Recovery System

NASA Technical Reports Server (NTRS)

Liu, James (Yuan); Litt, Jonathan; Sowers, T. Shane; Owens, A. Karl; Guo, Ten-Huei

2014-01-01

This presentation describes a model-predictive automatic recovery system for aircraft on the verge of a loss-of-control situation. The system determines when it must intervene to prevent an imminent accident, resulting from a poor approach. It estimates the altitude loss that would result from a go-around maneuver at the current flight condition. If the loss is projected to violate a minimum altitude threshold, the maneuver is automatically triggered. The system deactivates to allow landing once several criteria are met. Piloted flight simulator evaluation showed the system to provide effective envelope protection during extremely unsafe landing attempts. The results demonstrate how flight and propulsion control can be integrated to recover control of the vehicle automatically and prevent a potential catastrophe.

44 CFR 206.131 - Individual and Family Grant Program for major disasters declared on or before October 14, 2002.

Code of Federal Regulations, 2013 CFR

2013-10-01

... reflect changes in the Consumer Price Index for all Urban Consumers. IFG assistance for damages or losses...-eligible losses totaling $201 or more; those individuals with damages or losses of $200 or less to real or... Code. It may also mean the minor children of a couple not living together where the children live in...

44 CFR 206.131 - Individual and Family Grant Program for major disasters declared on or before October 14, 2002.

Code of Federal Regulations, 2012 CFR

2012-10-01

... reflect changes in the Consumer Price Index for all Urban Consumers. IFG assistance for damages or losses...-eligible losses totaling $201 or more; those individuals with damages or losses of $200 or less to real or... Code. It may also mean the minor children of a couple not living together where the children live in...

26 CFR 1.6011-4 - Requirement of statement disclosing participation in certain transactions by taxpayers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... disclosure protects the confidentiality of that advisor's tax strategies. A transaction is treated as... paragraph (b)(3), in determining the minimum fee, all fees for a tax strategy or for services for advice... taxpayer's tax return reflects tax consequences or a tax strategy described in the published guidance that...

7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

Code of Federal Regulations, 2010 CFR

2010-01-01

... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

Code of Federal Regulations, 2012 CFR

2012-01-01

... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

Code of Federal Regulations, 2011 CFR

2011-01-01

... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

Code of Federal Regulations, 2014 CFR

2014-01-01

... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

7 CFR 56.76 - Minimum facility and operating requirements for shell egg grading and packing plants.

Code of Federal Regulations, 2013 CFR

2013-01-01

... or rodents. (3) Buildings shall be of sound construction so as to prevent, insofar as practicable... cleaned at the end of each operating day. (5) The floors, walls, ceilings, partitions, and other parts of... reflection of light that interfere with, or prohibit the accurate quality determination of eggs in the...

Program For Optimization Of Nuclear Rocket Engines

NASA Technical Reports Server (NTRS)

Plebuch, R. K.; Mcdougall, J. K.; Ridolphi, F.; Walton, James T.

1994-01-01

NOP is versatile digital-computer program devoloped for parametric analysis of beryllium-reflected, graphite-moderated nuclear rocket engines. Facilitates analysis of performance of engine with respect to such considerations as specific impulse, engine power, type of engine cycle, and engine-design constraints arising from complications of fuel loading and internal gradients of temperature. Predicts minimum weight for specified performance.

Effect of volatile fatty acids in anaerobic conditions on viability of helminth ova (Ascaris suum) in sanitization of municipal sludge.

PubMed

Rojas-Oropeza, Marcelo; Hernández-Uresti, Alejandro S; Ortega-Charleston, Luis S; Cabirol, Nathalie

2017-09-01

The present work aimed at evaluating the effect of four different mixtures of diverse volatile fatty acids (VFAs) on the viability of helminth ova (Ascaris suum), under mesophilic (35°C) anaerobic conditions and at different incubation times, in order to reproduce the process of two-phase anaerobic digestion. The mixtures of VFAs contained acetic, propionic, butyric, valeric, and isovaleric acids, used at concentrations normally found in acidogenic anaerobic digesters. The four treatments all showed a reduction in Ascaris suum ova viability, among which Treatment III (4.2 g-acetic acid L -1  +  2.2 g-propionic acid L -1  + 0.6 g-valeric acid L -1  + 0.6 g-isovaleric acid L -1 ) resulted the most efficient. We found that the full effect of VFAs on the viability loss of Ascaris suum ova in mesophilic conditions requires a minimum incubation time of 3 days. The highest efficiency in the loss of viability was observed with Treatment III and 4-day incubation. Interestingly, the proportion of acetic acid was three times as much in this treatment than in the other ones and resulted in an effect in a minimum time of 3 days. The mesophilic condition, however, was not sufficient to induce a complete loss of viability.

Effective light coupling in reflective fiber optic distance sensors using a double-clad fiber

NASA Astrophysics Data System (ADS)

Werzinger, Stefan; Härteis, Lisa; Köhler, Aaron; Engelbrecht, Rainer; Schmauss, Bernhard

2017-04-01

Many fiber optic distance sensors use a reflective configuration, where a light beam is launched from an optical fiber, reflected from a target and coupled back into the fiber. While singlemode fibers (SMF) provide low-loss, high-performance components and a well-defined output beam, the coupling of the reflected light into the SMF is very sensitive to mechanical misalignments and scattering at the reflecting target. In this paper we use a double-clad fiber (DCF) and a DCF coupler to obtain an enhanced multimodal coupling of reflected light into the fiber. Increased power levels and robustness are achieved compared to a pure SMF configuration.

Recent X-ray Variability of eta Carinae: the Quick Road to Recovery

NASA Technical Reports Server (NTRS)

Corcoran, M. Francis; Hamaguchi, K.; Pittard, J. M.; Russell, C. M. P.; Owocki, S. P.; Parkin, E. R.; Okazaki, A.

2010-01-01

We report continued monitoring of the superluminous binary system eta Car by the Proportional Counter Array on the Rossi X-ray Timing Observatory (RXTE) through the 2009 X-ray minimum. The RXTE campaign shows that the minimum began on 2009 January 16, consistent with the phasings of the two previous minima, and overall, the temporal behavior of the X-ray emission was similar to that observed by RXTE in the previous two cycles. However, important differences did occur. The 2-10 keV X-ray flux and X-ray hardness decreased in the 2.5-year interval leading up to the 2009 minimum compared to the previous cycle. Most intriguingly, the 2009 X-ray minimum was about one month shorter than either of the previous two minima. During the egress from the 2009 minimum the X-ray hardness increased markedly as it had during egress from the previous two minima, although the maximum X-ray hardness achieved was less than the maximum observed after the two previous recoveries. We suggest that the cycle-to-cycle variations, especially the unexpectedly early recovery from the 2009 X-ray minimum, might have been the result of a decline in eta Car's wind momentum flux produced by a drop in eta Car's mass loss rate or wind terminal velocity (or some combination), though if so the change in wind momentum flux required to match the X-ray variation is surprisingly large.

Mo/Si multilayers with enhanced TiO II- and RuO II-capping layers

NASA Astrophysics Data System (ADS)

Yulin, Sergiy; Benoit, Nicolas; Feigl, Torsten; Kaiser, Norbert; Fang, Ming; Chandhok, Manish

2008-03-01

The lifetime of Mo/Si multilayer-coated projection optics is one of the outstanding issues on the road of commercialization of extreme-ultraviolet lithography (EUVL). The application of Mo/Si multilayer optics in EUVL requires both sufficient radiation stability and also the highest possible normal-incidence reflectivity. A serious problem of conventional high-reflective Mo/Si multilayers capped by silicon is the considerable degradation of reflective properties due to carbonization and oxidation of the silicon surface layer under exposure by EUV radiation. In this study, we focus on titanium dioxide (TiO II) and ruthenium dioxide (RuO II) as promising capping layer materials for EUVL multilayer coatings. The multilayer designs as well as the deposition parameters of the Mo/Si systems with different capping layers were optimized in terms of maximum peak reflectivity at the wavelength of 13.5 nm and longterm stability under high-intensive irradiation. Optimized TiO II-capped Mo/Si multilayer mirrors with an initial reflectivity of 67.0% presented a reflectivity drop of 0.6% after an irradiation dose of 760 J/mm2. The reflectivity drop was explained by the partial oxidation of the silicon sub-layer. No reflectivity loss after similar irradiation dose was found for RuO II-capped Mo/Si multilayer mirrors having initial peak reflectivity of 66%. In this paper we present data on improved reflectivity of interface-engineered TiO II- and RuO II-capped Mo/Si multilayer mirrors due to the minimization of both interdiffusion processes inside the multilayer stack and absorption loss in the oxide layer. Reflectivities of 68.5% at the wavelength of 13.4 nm were achieved for both TiO II- and RuO II-capped Mo/Si multilayer mirrors.

Transforaminal Anterior Release for the Treatment of Fixed Sagittal Imbalance and Segmental Kyphosis, Minimum 2-Year Follow-Up Study.

PubMed

Sweet, Fred A; Sweet, Andrea

2015-09-01

Retrospective review of prospectively accrued patient cohort. To report minimum 2 years' follow-up after a single-surgeon series of 47 consecutive patients in whom fixed sagittal imbalance or segmental kyphosis was treated with a novel unilateral transforaminal annular release. Fixed sagittal imbalance has been treated most recently with pedicle subtraction osteotomy with great success but is associated with significant blood loss and neurologic risk. Forty-seven consecutive patients with fixed sagittal imbalance (n = 29) or segmental kyphosis (n = 18) were treated by a single surgeon with a single-level transforaminal anterior release (TFAR) to effect an opening wedge correction. Sagittal and coronal correction was performed with in situ rod contouring. An interbody cage was captured in the disc space with rod compression. Radiographic and clinical outcome analysis was performed with a minimum 2-year follow-up (range 2-7.8 years). The average increase in lordosis was 36° (range 24°-56°) in the fixed sagittal deformity group. Coronal corrections averaged 34° (range 18°-48°). The average improvement in plumb line was 13.6 cm. There were four pseudarthroses, one at the TFAR. Average blood loss was 578 mL (range 200-1,200). One patient had a transient grade 4/5 anterior tibialis weakness. There were no vascular injuries or permanent neurologic deficits. There were significant improvements in the Oswestry Disability Index (p < .001) and Scoliosis Research Society Questionnaire scores (p = .003). Eighty-four percent of patients reported improvement in pain, self-image, and satisfaction with the procedure. TFAR is a useful procedure for correcting segmental kyphosis and fixed sagittal imbalance with relatively low blood loss and was found to be neurologically safe in this single-surgeon series. Therapeutic study, Level IV (case series, no control group). Copyright © 2015 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Charring temperatures are driven by the fuel types burned in a peatland wildfire

PubMed Central

Hudspith, Victoria A.; Belcher, Claire M.; Yearsley, Jonathan M.

2014-01-01

Peatlands represent a globally important carbon store; however, the human exploitation of this ecosystem is increasing both the frequency and severity of fires on drained peatlands. Yet, the interactions between the hydrological conditions (ecotopes), the fuel types being burned, the burn severity, and the charring temperatures (pyrolysis intensity) remain poorly understood. Here we present a post-burn assessment of a fire on a lowland raised bog in Co. Offaly, Ireland (All Saints Bog). Three burn severities were identified in the field (light, moderate, and deeply burned), and surface charcoals were taken from 17 sites across all burn severities. Charcoals were classified into two fuel type categories (either ground or aboveground fuel) and the reflectance of each charcoal particle was measured under oil using reflectance microscopy. Charcoal reflectance shows a positive relationship with charring temperature and as such can be used as a temperature proxy to reconstruct minimum charring temperatures after a fire event. Resulting median reflectance values for ground fuels are 1.09 ± 0.32%Romedian, corresponding to estimated minimum charring temperatures of 447°C ± 49°C. In contrast, the median charring temperatures of aboveground fuels were found to be considerably higher, 646°C ± 73°C (3.58 ± 0.77%Romedian). A mixed-effects modeling approach was used to demonstrate that the interaction effects of burn severity, as well as ecotope classes, on the charcoal reflectance is small compared to the main effect of fuel type. Our findings reveal that the different fuel types on raised bogs are capable of charring at different temperatures within the same fire, and that the pyrolysis intensity of the fire on All Saints Bog was primarily driven by the fuel types burning, with only a weak association to the burn severity or ecotope classes. PMID:25566288

Traveling-Wave Tube Amplifier Model to Predict High-Order Modulation Intersymbol Interference

NASA Technical Reports Server (NTRS)

Kory, Carol L.; Andro, Monty; Williams, W. D. (Technical Monitor)

2001-01-01

Demands for increased data rates in satellite communications necessitate higher order modulation schemes, larger system bandwidth, and minimum distortion of the modulated signal as it is passed through the traveling wave tube amplifier (TWTA). One type of distortion that the TWTA contributes to is intersymbol interference (ISI), and this becomes particularly disruptive with wide-band, complex modulation schemes. It is suspected that in addition to the dispersion of the TWT, frequency dependent reflections due to mismatches within the TWT are a significant contributor to ISI. To experimentally investigate the effect of these mismatches within the physical TWT on ISI would be prohibitively expensive, as it would require manufacturing numerous amplifiers in addition to the acquisition of the required digital hardware. In an attempt to develop a more accurate model to correlate IS1 with the TWTA and the operational signal, a fully three-dimensional (3D), time-dependent, TWT interaction model has been developed using the electromagnetic particle-in-cell (PIC) code MAFIA (solution of Maxwell's equations by the Finite-Integration-Algorithm). The model includes a user defined slow-wave circuit with a spatially tapered region of loss to implement a sever, and spatially varied geometry (such as helical pitch) to implement a phase velocity taper. The model also includes user defined input/output coupling and an electron beam contained by solenoidal, electrostatic, or periodic permanent magnet (PPM) focusing allowing standard or novel TWTs to be investigated. This model comprehensively takes into account the effects of frequency dependent nonlinear distortions (MAM and AMPM); gain ripple due to frequency dependent reflections at the input/output coupling, severs, and mismatches from dynamic pitch variations; drive induced oscillations; harmonic generation; intermodulation products; and backward waves.

Energy loss from internal reflection off metal layers on glass

NASA Astrophysics Data System (ADS)

McDowell, M. W.; Bezuidenhout, D. F.; Klee, H. W.; Theron, E.

1983-12-01

The reflection characteristics of metal layers are considered for the situation where the electromagnetic radiation is incident from the glass side. Theoretical and measured reflectance values are presented which indicate that for some metals the reflection has a strong dependence on the refractive index of the incident medium. Some examples are given of recent cases where the above results were an important consideration in the choice of the metallic reflecting material. These results indicate that aluminium should not be automatically considered the best choice for the visible region nor gold for the infra-red.

High-reflective colorful films fabricated by all-solid multi-layer cholesteric structures

NASA Astrophysics Data System (ADS)

Li, Y.; Luo, D.

2018-02-01

We demonstrate all-solid-state film with high-reflectivity based on cholesteric template. The adhesive (NOA81) is both filler and an adhesive, which can be avoids interfacial losses. The reflected right- and left-circularly polarized light has been developed by roll-to-roll method, and the reflectance of the films is more than 78%. Here, the all-solid film was used in distribute feedback laser with dye-doped. In addition, this films also used in include flexible reflective display, color pixels in digital photographs, printing and colored cladding of variety of objects.

The role of serotonin in nonnormative risky choice: the effects of tryptophan supplements on the "reflection effect" in healthy adult volunteers.

PubMed

Murphy, Susannah E; Longhitano, Carlo; Ayres, Rachael E; Cowen, Philip J; Harmer, Catherine J; Rogers, Robert D

2009-09-01

Risky decision-making involves weighing good and bad outcomes against their probabilities in order to determine the relative values of candidate actions. Although human decision-making sometimes conforms to rational models of how this weighting is achieved, irrational (or nonnormative) patterns of risky choice, including shifts between risk-averse and risk-seeking choices involving equivalent-value gambles (the "reflection effect"), are frequently observed. In the present experiment, we investigated the role of serotonin in decision-making under conditions of uncertainty. Fifteen healthy adult volunteers received a treatment of 3 g per day of the serotonin precursor, tryptophan, in the form of dietary supplements over a 14-day period, whereas 15 age- and IQ-matched control volunteers received a matched placebo substance. At test, all participants completed a risky decision-making task involving a series of choices between two simultaneously presented gambles, differing in the magnitude of their possible gains, the magnitude of their possible losses, and the probabilities with which these outcomes were delivered. Tryptophan supplements were associated with alterations in the weighting of gains and small losses perhaps reflecting reduced loss-aversion, and a marked and significant diminution of the reflection effect. We conclude that serotonin activity plays a significant role in nonnormative risky decision-making under conditions of uncertainty.

Multimodal coherent anti-Stokes Raman scattering microscopy reveals microglia-associated myelin and axonal dysfunction in multiple sclerosis-like lesions in mice

PubMed Central

Imitola, Jaime; Côté, Daniel; Rasmussen, Stine; Xie, X. Sunney; Liu, Yingru; Chitnis, Tanuja; Sidman, Richard L.; Lin, Charles. P.; Khoury, Samia J.

2011-01-01

Myelin loss and axonal degeneration predominate in many neurological disorders; however, methods to visualize them simultaneously in live tissue are unavailable. We describe a new imaging strategy combining video rate reflectance and fluorescence confocal imaging with coherent anti-Stokes Raman scattering (CARS) microscopy tuned to CH2 vibration of myelin lipids, applied in live tissue of animals with chronic experimental autoimmune encephalomyelitis (EAE). Our method allows monitoring over time of demyelination and neurodegeneration in brain slices with high spatial resolution and signal-to-noise ratio. Local areas of severe loss of lipid signal indicative of demyelination and loss of the reflectance signal from axons were seen in the corpus callosum and spinal cord of EAE animals. Even in myelinated areas of EAE mice, the intensity of myelin lipid signals is significantly reduced. Using heterozygous knock-in mice in which green fluorescent protein replaces the CX3CR1 coding sequence that labels central nervous system microglia, we find areas of activated microglia colocalized with areas of altered reflectance and CARS signals reflecting axonal injury and demyelination. Our data demonstrate the use of multimodal CARS microscopy for characterization of demyelinating and neurodegenerative pathology in a mouse model of multiple sclerosis, and further confirm the critical role of microglia in chronic inflammatory neurodegeneration. PMID:21361672

Plasmonically Enhanced Reflectance of Heat Radiation from Low-Bandgap Semiconductor Microinclusions.

PubMed

Tang, Janika; Thakore, Vaibhav; Ala-Nissila, Tapio

2017-07-18

Increased reflectance from the inclusion of highly scattering particles at low volume fractions in an insulating dielectric offers a promising way to reduce radiative thermal losses at high temperatures. Here, we investigate plasmonic resonance driven enhanced scattering from microinclusions of low-bandgap semiconductors (InP, Si, Ge, PbS, InAs and Te) in an insulating composite to tailor its infrared reflectance for minimizing thermal losses from radiative transfer. To this end, we compute the spectral properties of the microcomposites using Monte Carlo modeling and compare them with results from Fresnel equations. The role of particle size-dependent Mie scattering and absorption efficiencies, and, scattering anisotropy are studied to identify the optimal microinclusion size and material parameters for maximizing the reflectance of the thermal radiation. For composites with Si and Ge microinclusions we obtain reflectance efficiencies of 57-65% for the incident blackbody radiation from sources at temperatures in the range 400-1600 °C. Furthermore, we observe a broadbanding of the reflectance spectra from the plasmonic resonances due to charge carriers generated from defect states within the semiconductor bandgap. Our results thus open up the possibility of developing efficient high-temperature thermal insulators through use of the low-bandgap semiconductor microinclusions in insulating dielectrics.

Optical study of solar tower power plants

NASA Astrophysics Data System (ADS)

Eddhibi, F.; Ben Amara, M.; Balghouthi, M.; Guizani, A.

2015-04-01

The central receiver technology for electricity generation consists of concentrating solar radiation coming from the solar tracker field into a central receiver surface located on the top of the tower. The heliostat field is constituted of a big number of reflective mirrors; each heliostat tracks the sun individually and reflects the sunlight to a focal point. Therefore, the heliostat should be positioned with high precision in order to minimize optical losses. In the current work, a mathematical model for the analysis of the optical efficiency of solar tower field power plant is proposed. The impact of the different factors which influence the optical efficiency is analyzed. These parameters are mainly, the shading and blocking losses, the cosine effect, the atmospheric attenuation and the spillage losses. A new method for the calculation of blocking and shadowing efficiency is introduced and validated by open literature.

Deformed ellipsoidal diffraction grating blank

NASA Technical Reports Server (NTRS)

Decew, Alan E., Jr.

1994-01-01

The Deformed Ellipsoidal Grating Blank (DEGB) is the primary component in an ultraviolet spectrometer. Since one of the major concerns for these instruments is throughput, significant efforts are made to reduce the number of components and subsequently reflections. Each reflection results in losses through absorption and scattering. It is these two sources of photon loss that dictated the requirements for the DEGB. The first goal is to shape the DEGB in such a way that the energy at the entrance slit is focused as well as possible on the exit slit. The second goal is to produce a surface smooth enough to minimize the photon loss due to scattering. The program was accomplished in three phases. The first phase was the fabrication planning. The second phase was the actual fabrication and initial testing. The last phase was the final testing of the completed DEGB.

On the Need to Live Educational Foundations

ERIC Educational Resources Information Center

Schubert, William H.

2013-01-01

William H. Schubert, retired faculty member at the University of Illinois, Chicago, reflects on his teaching career and the loss of "educational foundations." Schubert states that "Foundations of Education" are being pushed toward the precipice of extinction. He describes a loss of "back-to-basics" education with a…

49 CFR 582.5 - Information form.

Code of Federal Regulations, 2010 CFR

2010-10-01

... with Federal law as an aid to consumers considering the purchase of a new vehicle. The booklet compares... reflects the collision loss experience of passenger cars, utility vehicles, light trucks, and vans sold in...' collision loss experience in relative terms, with 100 representing the average for all passenger vehicles...

Lightweight NiFe2O4 with controllable 3D network structure and enhanced microwave absorbing properties

NASA Astrophysics Data System (ADS)

Wang, Fen; Wang, Xing; Zhu, Jianfeng; Yang, Haibo; Kong, Xingang; Liu, Xiao

2016-11-01

3D network structure NiFe2O4 was successfully synthesized by a templated salt precipitation method using PMMA colloid crystal as templates. The morphology, phase composition and microwave absorbing properties of as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vector network analyzer (VNA), and so on. The results revealed that the 3D network structure was configurated with smooth spherical walls composed of NiFe2O4 nanocrystals and their pore diameters being in the range of 80-250 nm. The microwave absorption properties of the 3D network structure NiFe2O4 were crucially determined by the special structure. The synergy of intrinsic magnetic loss of magnetic NiFe2O4 and the interfacial polarization enhanced by 3D network structure and the interaction of multiple mechanisms endowed the sample with the feature of strong absorption, broad bandwidth and lightweight. There is more than one valley in the reflection loss curves and the maximum reflection loss is 27.5 dB with a bandwidth of 4 GHz. Moreover, the 3D network structure NiFe2O4 show a greater reflection loss with the same thickness comparing to the ordinary NiFe2O4 nanoparticles, which could achieve the feature of lightweight of the microwave absorbing materials.

Lightweight NiFe2O4 with controllable 3D network structure and enhanced microwave absorbing properties

PubMed Central

Wang, Fen; Wang, Xing; Zhu, Jianfeng; Yang, Haibo; Kong, Xingang; Liu, Xiao

2016-01-01

3D network structure NiFe2O4 was successfully synthesized by a templated salt precipitation method using PMMA colloid crystal as templates. The morphology, phase composition and microwave absorbing properties of as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vector network analyzer (VNA), and so on. The results revealed that the 3D network structure was configurated with smooth spherical walls composed of NiFe2O4 nanocrystals and their pore diameters being in the range of 80–250 nm. The microwave absorption properties of the 3D network structure NiFe2O4 were crucially determined by the special structure. The synergy of intrinsic magnetic loss of magnetic NiFe2O4 and the interfacial polarization enhanced by 3D network structure and the interaction of multiple mechanisms endowed the sample with the feature of strong absorption, broad bandwidth and lightweight. There is more than one valley in the reflection loss curves and the maximum reflection loss is 27.5 dB with a bandwidth of 4 GHz. Moreover, the 3D network structure NiFe2O4 show a greater reflection loss with the same thickness comparing to the ordinary NiFe2O4 nanoparticles, which could achieve the feature of lightweight of the microwave absorbing materials. PMID:27897209

The Raising of Minimum Alcohol Prices in Saskatchewan, Canada: Impacts on Consumption and Implications for Public Health

PubMed Central

Zhao, Jinhui; Giesbrecht, Norman; Macdonald, Scott; Thomas, Gerald; Wettlaufer, Ashley

2012-01-01

Objectives. We report impacts on alcohol consumption following new and increased minimum alcohol prices in Saskatchewan, Canada. Methods. We conducted autoregressive integrated moving average time series analyses of alcohol sales and price data from the Saskatchewan government alcohol monopoly for 26 periods before and 26 periods after the intervention. Results. A 10% increase in minimum prices significantly reduced consumption of beer by 10.06%, spirits by 5.87%, wine by 4.58%, and all beverages combined by 8.43%. Consumption of coolers decreased significantly by 13.2%, cocktails by 21.3%, and liqueurs by 5.3%. There were larger effects for purely off-premise sales (e.g., liquor stores) than for primarily on-premise sales (e.g., bars, restaurants). Consumption of higher strength beer and wine declined the most. A 10% increase in minimum price was associated with a 22.0% decrease in consumption of higher strength beer (> 6.5% alcohol/volume) versus 8.17% for lower strength beers. The neighboring province of Alberta showed no change in per capita alcohol consumption before and after the intervention. Conclusions. Minimum pricing is a promising strategy for reducing the public health burden associated with hazardous alcohol consumption. Pricing to reflect percentage alcohol content of drinks can shift consumption toward lower alcohol content beverage types. PMID:23078488

Operational G-induced loss of consciousness: something old; something new.

PubMed

Burton, R R; Whinnery, J E

1985-08-01

Loss of consciousness (LOC) during exposure to +Gz occurs in aircrew flying high-performance aircraft. This phenomenon is responsible for several USAF aircraft losses with accompanying loss of life. It has been recognized as a potential flying problem since 1938. Acceleration-induced LOC results in 15-to 20-s periods of aircrew total incapacitation, amnesia, and clonic spasms. It can occur at relatively low G levels and without symptoms of loss of light (blackout). Operational anti-G equipment and methods are not completely effective in preventing LOC. Considering the present status of G protection, a deficiency in the anti-G straining maneuver is considered to be the primary cause of G-induced LOC. This deficiency usually can be corrected with proper centrifuge training. Our present understanding of G protection suggests that the elimination of LOC as a serious problem for USAF high-performance aircraft operations must include the supination of aircrew to a minimum seat back angle of 60 degrees to 65 degrees.

Prospect Theory for Online Financial Trading

PubMed Central

Martino, Mauro; Altshuler, Yaniv

2014-01-01

Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the “reflection effect”. People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called “loss aversion”. Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior. PMID:25330203

Prospect theory for online financial trading.

PubMed

Liu, Yang-Yu; Nacher, Jose C; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv

2014-01-01

Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the "reflection effect". People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called "loss aversion". Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior.

The Multidimensional Loss Scale: validating a cross-cultural instrument for measuring loss.

PubMed

Vromans, Lyn; Schweitzer, Robert D; Brough, Mark

2012-04-01

The Multidimensional Loss Scale (MLS) represents the first instrument designed specifically to index Experience of Loss Events and Loss Distress across multiple domains (cultural, social, material, and intrapersonal) relevant to refugee settlement. Recently settled Burmese adult refugees (N = 70) completed a questionnaire battery, including MLS items. Analyses explored MLS internal consistency, convergent and divergent validity, and factor structure. Cronbach alphas indicated satisfactory internal consistency for Experience of Loss Events (0.85) and Loss Distress (0.92), reflecting a unitary construct of multidimensional loss. Loss Distress did not correlate with depression or anxiety symptoms and correlated moderately with interpersonal grief and trauma symptoms, supporting divergent and convergent validity. Factor analysis provided preliminary support for a five-factor model: Loss of Symbolic Self, Loss of Interdependence, Loss of Home, Interpersonal Loss, and Loss of Intrapersonal Integrity. Received well by participants, the new scale shows promise for application in future research and practice.

One-dimensional carbon nanotube@barium titanate@polyaniline multiheterostructures for microwave absorbing application

NASA Astrophysics Data System (ADS)

Ni, Qing-Qing; Zhu, Yao-Feng; Yu, Lu-Jun; Fu, Ya-Qin

2015-04-01

Multiple-phase nanocomposites filled with carbon nanotubes (CNTs) have been developed for their significant potential in microwave attenuation. The introduction of other phases onto the CNTs to achieve CNT-based heterostructures has been proposed to obtain absorbing materials with enhanced microwave absorption properties and broadband frequency due to their different loss mechanisms. The existence of polyaniline (PANI) as a coating with controllable electrical conductivity can lead to well-matched impedance. In this work, a one-dimensional CNT@BaTiO3@PANI heterostructure composite was fabricated. The fabrication processes involved coating of an acid-modified CNT with BaTiO3 (CNT@BaTiO3) through a sol-gel technique followed by combustion and the formation of CNT@BaTiO3@PANI nanohybrids by in situ polymerization of an aniline monomer in the presence of CNT@BaTiO3, using ammonium persulfate as an oxidant and HCl as a dopant. The as-synthesized CNT@BaTiO3@PANI composites with heterostructures were confirmed by various morphological and structural characterization techniques, as well as conductivity and microwave absorption properties. The measured electromagnetic parameters showed that the CNT@BaTiO3@PANI composites exhibited excellent microwave absorption properties. The minimum reflection loss of the CNT@BaTiO3@PANI composites with 20 wt % loadings in paraffin wax reached -28.9 dB (approximately 99.87% absorption) at 10.7 GHz with a thickness of 3 mm, and a frequency bandwidth less than -20 dB was achieved from 10 to 15 GHz. This work demonstrated that the CNT@BaTiO3@PANI heterostructure composite can be potentially useful in electromagnetic stealth materials, sensors, and electronic devices.

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

Seidfaraji, Hamide, E-mail: hsfaraji@unm.edu; Fuks, Mikhail I.; Christodoulou, Christos

Most dangerous explosive materials, both toxic and radioactive, contain nitrogen salts with resonant absorption lines in the frequency range 0.3-10 THz. Therefore, there has been growing interest in remotely detecting such materials by observing the spectrum of reflected signals when the suspicious material is interrogated by THz radiation. Practical portable THz sources available today generate only 20–40 mW output power. This power level is too low to interrogate suspicious material from a safe distance, especially if the material is concealed. Hence, there is a need for sources that can provide greater power in the THz spectrum. Generating and extracting highmore » output power from THz sources is complicated and inefficient. The efficiency of vacuum electronic microwave sources is very low when scaled to the THz range and THz sources based on scaling down semiconductor laser sources have low efficiency as well, resulting in the well known “THz gap.” The reason for such low efficiencies for both source types is material losses in the THz band. In this article an efficient power combiner is described that is based on scaling to higher frequencies a microwave combiner that increases the output power in the THz range of interest in simulation studies. The proposed power combiner not only combines the THz power output from several sources, but can also form a Gaussian wavebeam output. A minimum conversion efficiency of 89% with cophased inputs in a lossy copper power combiner and maximum efficiency of 100% in a Perfect Electric Conductor (PEC)-made power combiner were achieved in simulations. Also, it is shown that the TE{sub 01} output mode is a reasonable option for THz applications due to the fact that conductive loss decreases for this mode as frequency increases.« less

One-dimensional carbon nanotube@barium titanate@polyaniline multiheterostructures for microwave absorbing application.

PubMed

Ni, Qing-Qing; Zhu, Yao-Feng; Yu, Lu-Jun; Fu, Ya-Qin

2015-01-01

Multiple-phase nanocomposites filled with carbon nanotubes (CNTs) have been developed for their significant potential in microwave attenuation. The introduction of other phases onto the CNTs to achieve CNT-based heterostructures has been proposed to obtain absorbing materials with enhanced microwave absorption properties and broadband frequency due to their different loss mechanisms. The existence of polyaniline (PANI) as a coating with controllable electrical conductivity can lead to well-matched impedance. In this work, a one-dimensional CNT@BaTiO3@PANI heterostructure composite was fabricated. The fabrication processes involved coating of an acid-modified CNT with BaTiO3 (CNT@BaTiO3) through a sol-gel technique followed by combustion and the formation of CNT@BaTiO3@PANI nanohybrids by in situ polymerization of an aniline monomer in the presence of CNT@BaTiO3, using ammonium persulfate as an oxidant and HCl as a dopant. The as-synthesized CNT@BaTiO3@PANI composites with heterostructures were confirmed by various morphological and structural characterization techniques, as well as conductivity and microwave absorption properties. The measured electromagnetic parameters showed that the CNT@BaTiO3@PANI composites exhibited excellent microwave absorption properties. The minimum reflection loss of the CNT@BaTiO3@PANI composites with 20 wt % loadings in paraffin wax reached -28.9 dB (approximately 99.87% absorption) at 10.7 GHz with a thickness of 3 mm, and a frequency bandwidth less than -20 dB was achieved from 10 to 15 GHz. This work demonstrated that the CNT@BaTiO3@PANI heterostructure composite can be potentially useful in electromagnetic stealth materials, sensors, and electronic devices.

Active-optical reflectance sensing evaluated for red and red-edge waveband sensitivity

USDA-ARS?s Scientific Manuscript database

Uncertainty exists with corn (Zea mays L.) N management due to year-to-year variation in crop N need, soil N supply, and N loss from leaching, volatilization, and denitrification. Active-optical reflectance sensing (AORS) has proven effective in some fields for generating N fertilizer recommendation...

Optimization of 248nm bottom anti-reflective coatings with thin film and high etch rate on real device

NASA Astrophysics Data System (ADS)

Kim, MyoungSoo; Kim, HakJoon; Shim, KewChan; Jeon, JeHa; Gil, MyungGoon; Song, YongWook; Enomoto, Tomoyuki; Sakaguchi, Takahiro; Nakajima, Yasuyuki

2005-05-01

A frequent problem encountered by photoresists during the manufacturing of semiconductor device is that activating radiation is reflected back into the photoresist by the substrate. So, it is necessary that the light reflection is reduced from the substrate. One approach to reduce the light reflection is the use of bottom anti-reflective coating (BARC) applied to the substrate beneath the photoresist layer. The BARC technology has been utilized for a few years to minimize the reflectivity. As the chip size is reduced to sub 100nm, the photoresist thickness has to decrease with the aspect ratio being less than 3.0. Therefore, new Organic BARC is strongly required which has the minimum reflectivity with thinner BARC thickness and higher etch selectivity toward resists. Hynix Semiconductor Inc., Nissan Chemical Industries, Ltd., and Brewer Science, Inc. have developed the advanced Organic BARC for achieving the above purpose. As a result, the suitable high performance 248nm Organic BARCs, NCA series, were achieved. Using CF4 gas as etchant, the plasma etch rate of NCA series is about 1.4 times higher than that of conventional 248nm resists. NCA series can be minimizing the substrate reflectivity at below 45nm BARC thickness. NCA series show the excellent litho performance and coating property on real device.

14 CFR Section 24 - Profit and Loss Elements

Code of Federal Regulations, 2014 CFR

2014-01-01

... Maintenance Burden” shall reflect a memorandum allocation by each air carrier of the total expenses included... operation personnel in readiness for assignment to an in-flight status. (2) “Maintenance” shall include all... line 5 of this schedule. (f) “Operating Profit (Loss)” shall be computed by subtracting the total...

14 CFR Section 24 - Profit and Loss Elements

Code of Federal Regulations, 2013 CFR

2013-01-01

... Maintenance Burden” shall reflect a memorandum allocation by each air carrier of the total expenses included... operation personnel in readiness for assignment to an in-flight status. (2) “Maintenance” shall include all... line 5 of this schedule. (f) “Operating Profit (Loss)” shall be computed by subtracting the total...

14 CFR Section 24 - Profit and Loss Elements

Code of Federal Regulations, 2011 CFR

2011-01-01

... Maintenance Burden” shall reflect a memorandum allocation by each air carrier of the total expenses included... operation personnel in readiness for assignment to an in-flight status. (2) “Maintenance” shall include all... line 5 of this schedule. (f) “Operating Profit (Loss)” shall be computed by subtracting the total...

Rainfall erosivity: An overview of methodologies and applications

USDA-ARS?s Scientific Manuscript database

The rainfall erosivity factor (R-factor) is one of six erosion factors in the Universal Soil Loss Equation (USLE), together which reflect the combined effects that cause soil loss by rill and interrill erosion on hillslopes by precipitation. It is defined as the summation of event EI30 (the product ...

Pedagogical Reflections on Loss

ERIC Educational Resources Information Center

Stearns, Clio

2013-01-01

This article examines the idea of loss in relation to elementary education. The goal is to show the importance of teachers attending to their students' individual experience and, in particular, to the ways schools can make children feel lost or found. The article relies primarily on classroom narratives, focusing heavily on stories about one…

[Comprehension of hazard pictograms of chemical products among cleaning workers].

PubMed

Martí Fernández, Francesc; van der Haar, Rudolf; López López, Juan Carlos; Portell, Mariona; Torner Solé, Anna

2015-01-01

To assess the comprehension among cleaning workers of the hazard pictograms as defined by the Globally Harmonized System (GHS) of the United Nations, concerning the classification, labeling and packaging of substances and mixtures. A sample of 118 workers was surveyed on their perception of the GHS hazard pictograms. Comprehensibility was measured by the percentage of correct answers and the degree to which they reflected International Organization for Standardization and American National Standards Institute standards for minimum level of comprehension. The influence of different variables to predict comprehension capacity was assessed using a logistic regression model. Three groups of pictograms could be distinguished which were statistically differentiated by their comprehensibility. Pictograms reflecting "acute toxicity" and "flammable", were described correctly by 94% and 95% of the surveyed population, respectively. For pictograms reflecting "systemic toxicity", "corrosive", "warning", "environment" and "explosive" the frequency of correct answers ranged from 48% to 64%, whereas those for pictograms "oxidizing" and "compressed gas" were interpreted correctly by only 7% of respondents. Prognostic factors for poor comprehension included: not being familiar with the pictograms, not having received training on safe use of chemical products, being an immigrant and being 54 years of age or older. Only two pictograms exceeded minimum standards for comprehension. Training, a tool proven to be effective to improve the correct interpretation of danger symbols, should be encouraged, especially in those groups with greater comprehension difficulties. Copyright belongs to the Societat Catalana de Salut Laboral.

Full-wave feasibility study of anti-radar diagnostic of magnetic field based on O-X mode conversion and oblique reflectometry imaging

DOE PAGES

Meneghini, Orso; Volpe, Francesco A.

2016-08-19

An innovative millimeter wave diagnostic is proposed to measure the local magnetic field and edge current as a function of the minor radius in the tokamak pedestal region. The idea is to identify the direction of minimum reflectivity at the O-mode cutoff layer. Correspondingly, the transmissivity due to O-X mode conversion is maximum. That direction, and the angular map of reflectivity around it, contain information on the magnetic field vector B at the cutoff layer. By probing the plasma with different wave frequencies it provides the radial profile of B. Full-wave finite-element simulations are presented here in 2D slab geometry.more » Modeling confirms the existence of a minimum in reflectivity that depends on the magnetic field at the cutoff, as expected from mode conversion physics, giving confidence in the feasibility of the diagnostic. We proposed an reflectometric approach in order to yield superior signal-to-noise ratio and to access wider ranges of density and magnetic field, compared with related radiometric techniques that require the plasma to emit Electron Bernstein Waves. Due to computational limitations, frequencies of 10-20 GHz were considered in this initial study. Furthermore, frequencies above the edge electron-cyclotron frequency (f >28 GHz here) would be preferable for the experiment, because the upper hybrid resonance and right cutoff would lie in the plasma, and would help separate the O-mode of interest from spurious X-waves.« less

Full-wave feasibility study of anti-radar diagnostic of magnetic field based on O-X mode conversion and oblique reflectometry imaging

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

Meneghini, Orso; Volpe, Francesco A., E-mail: fvolpe@columbia.edu

An innovative millimeter wave diagnostic is proposed to measure the local magnetic field and edge current as a function of the minor radius in the tokamak pedestal region. The idea is to identify the direction of minimum reflectivity at the O-mode cutoff layer. Correspondingly, the transmissivity due to O-X mode conversion is maximum. That direction, and the angular map of reflectivity around it, contains information on the magnetic field vector B at the cutoff layer. Probing the plasma with different wave frequencies provides the radial profile of B. Full-wave finite-element simulations are presented here in 2D slab geometry. Modeling confirmsmore » the existence of a minimum in reflectivity that depends on the magnetic field at the cutoff, as expected from mode conversion physics, giving confidence in the feasibility of the diagnostic. The proposed reflectometric approach is expected to yield superior signal-to-noise ratio and to access wider ranges of density and magnetic field, compared with related radiometric techniques that require the plasma to emit electron Bernstein waves. Due to computational limitations, frequencies of 10-20 GHz were considered in this initial study. Frequencies above the edge electron-cyclotron frequency (f > 28 GHz here) would be preferable for the experiment, because the upper hybrid resonance and right cutoff would lie in the plasma, and would help separate the O-mode of interest from spurious X-waves.« less

Discrete Mathematics in Deaf Education: A Survey of Teachers' Knowledge and Use

ERIC Educational Resources Information Center

Pagliaro, C.; Kritzer, K. L.

2005-01-01

The study documents what deaf education teachers know about discrete mathematics topics and determines if these topics are present in the mathematics curriculum. Survey data were collected from 290 mathematics teachers at center and public school programs serving a minimum of 120 students with hearing loss, grades K-8 or K-12, in the United…

Minimum cost strategies for sequestering carbon in forests.

Treesearch

Darius M. Adams; Ralph J. Alig; Bruce A. McCarl; John M. Callaway; Steven M. Winnett

1999-01-01

This paper examines the costs of meeting explicit targets for increments of carbon sequestered in forests when both forest management decisions and the area of forests can be varied. Costs are estimated as welfare losses in markets for forest and agricultural products. Results show greatest change in management actions when targets require large near-term flux...

CFD simulation of pesticide spray from air-assisted sprayers in an apple orchard: tree deposition and off-target losses

USDA-ARS?s Scientific Manuscript database

The ultimate goal of a pesticide spraying system is to provide adequate coverage on intended canopies with a minimum amount of spray materials and off-target waste. Better spray coverage requires an understanding of the fate and transport of spray droplets carried by turbulent airflows in orchards. ...

77 FR 19069 - Airworthiness Directives; Goodrich Evacuation Systems Approved Under Technical Standard Order...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... seal and allowed the pressure in certain slides/ rafts to fall below the minimum raft mode pressure for the unit. We are issuing this AD to prevent loss of pressure in the escape slides/rafts after an emergency evacuation, which could result in inadequate buoyancy to support the raft's passenger capacity...

26 CFR 1.57-1 - Items of tax preference defined.

Code of Federal Regulations, 2010 CFR

2010-04-01

... was used, such as, for example, by application of section 167(k), or salvage value was not taken into... depletion as a result ot the minimum tax. (i) Capital gains—(1) Taxpayers other than corporations. Section... gain for the taxable year exceeds the taxpayer's net short-term capital loss for the taxable year. For...

26 CFR 1.57-1 - Items of tax preference defined.

Code of Federal Regulations, 2011 CFR

2011-04-01

... was used, such as, for example, by application of section 167(k), or salvage value was not taken into... depletion as a result ot the minimum tax. (i) Capital gains—(1) Taxpayers other than corporations. Section... gain for the taxable year exceeds the taxpayer's net short-term capital loss for the taxable year. For...

26 CFR 1.57-1 - Items of tax preference defined.

Code of Federal Regulations, 2014 CFR

2014-04-01

... was used, such as, for example, by application of section 167(k), or salvage value was not taken into... depletion as a result ot the minimum tax. (i) Capital gains—(1) Taxpayers other than corporations. Section... gain for the taxable year exceeds the taxpayer's net short-term capital loss for the taxable year. For...

26 CFR 1.57-1 - Items of tax preference defined.

Code of Federal Regulations, 2012 CFR

2012-04-01

... was used, such as, for example, by application of section 167(k), or salvage value was not taken into... depletion as a result ot the minimum tax. (i) Capital gains—(1) Taxpayers other than corporations. Section... gain for the taxable year exceeds the taxpayer's net short-term capital loss for the taxable year. For...

26 CFR 1.57-1 - Items of tax preference defined.

Code of Federal Regulations, 2013 CFR

2013-04-01

... was used, such as, for example, by application of section 167(k), or salvage value was not taken into... depletion as a result ot the minimum tax. (i) Capital gains—(1) Taxpayers other than corporations. Section... gain for the taxable year exceeds the taxpayer's net short-term capital loss for the taxable year. For...

Microwave absorption property of the diatomite coated by Fe-CoNiP films

NASA Astrophysics Data System (ADS)

Yan, Zhenqiang; Cai, Jun; Xu, Yonggang; Zhang, Deyuan

2015-08-01

A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2-18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL -11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density.

Exercise at 65 and beyond.

PubMed

Batt, Mark E; Tanji, Jeffrey; Börjesson, Mats

2013-07-01

Aging is characterized by increasing muscle loss, physical inactivity and frailty. Physical inactivity is known to be associated with increased incidence of obesity and many life-threatening chronic conditions. We know that exercise, through many factors including antiinflammatory effects and enhanced fitness, can help prevent and treat many chronic diseases as well as help maintain independent living. We set out to demonstrate the utility of regular exercise in this potentially vulnerable age group in both the treatment and prevention of chronic diseases. The benefits, risks and recommendations for physical activity are discussed with an emphasis on practical advice for safe exercise in the context of established international guidelines. These guidelines typically state that 150 min per week of moderate aerobic intensity exercise should be achieved with some additional whole-body strength training and balance work. Individual risk assessment should be undertaken in a way to enable safe exercise participation to achieve maximum benefit with minimum risk. The risk assessment, subsequent advice and prescription for exercise should be personalized to reflect individual fitness and functional levels as well as patient safety. Newer and potentially exciting benefits of exercise are discussed in the areas of neuroscience and inflammation where data are suggesting positive effects of exercise in maintaining memory and cognition as well as having beneficial antiinflammatory effects.

Ultrafast carrier dynamics in a GaN/Al 0.18Ga0.82N superlattice

NASA Astrophysics Data System (ADS)

Mahler, Felix; Tomm, Jens W.; Reimann, Klaus; Woerner, Michael; Elsaesser, Thomas; Flytzanis, Christos; Hoffmann, Veit; Weyers, Markus

2018-04-01

Relaxation processes of photoexcited carriers in a GaN /Al0.18Ga0.82N superlattice are studied in femtosecond spectrally resolved reflectivity measurements at ambient temperature. The transient reflectivity reveals electron trapping into defect states close to the conduction-band minimum with a 150-200 fs time constant, followed by few-picosecond carrier cooling. A second slower trapping process into a different manifold of defect states is observed on a time scale of approximately 10 ps. Our results establish the prominent role of structural defects and disorder for ultrafast carrier dynamics in nitride semiconductor structures.

A robotic reflective Schmidt telescope for Dome C

NASA Astrophysics Data System (ADS)

Strassmeier, K. G.; Andersen, M. I.; Steinbach, M.

2004-10-01

This paper lays out a wide-field robotic Schmidt telescope (RST) for the Antarctic site Dome C. The telescope is based on 80/120cm reflective Schmidt optics, built originally for a space project, and a mosaic of four 7.5k×7.5k 8-μm thinned CCDs from the PEPSI/LBT wafer run. The telescope's total field of view (FOV) would be 5o circular (minimum 3o× 3o square) with a plate scale of 0.7 arcsec per pixel. Limiting magnitude is expected to be V=21.5mag in 60 sec for a field of 9 square degrees.

Excitation of whistler waves by reflected auroral electrons

NASA Technical Reports Server (NTRS)

Wu, C. S.; Dillenburg, D.; Ziebell, L. F.; Freund, H. P.

1983-01-01

Excitation of electron waves and whistlers by reflected auroral electrons which possess a loss-cone distribution is investigated. Based on a given magnetic field and density model, the instability problem is studied over a broad region along the auroral field lines. This region covers altitudes ranging from one quarter of an earth radius to five earth radii. It is found that the growth rate is significant only in the region of low altitude, say below the source region of the auroral kilometric radiation. In the high altitude region the instability is insignificant either because of low refractive indices or because of small loss cone angles.

Light Reflector

NASA Astrophysics Data System (ADS)

1988-01-01

Ultra Sales, Inc.'s fluorescent lighting fixture gets a boost in reflectivity through installation of Lightdriver, a thin tough thermoplastic film plated with aluminum, capable of reflecting 95 percent of visible light striking it. Lightdriver increases brightness without adding bulbs, and allows energy savings by removing some bulbs because the mirrorlike surface cuts light loss generally occasioned by conventional low reflectivity white painted surface above the bulbs in many fluorescent fixtures. Forty-five percent reduction in lighting electricity is attainable.

Moving beyond the Minimum: Socially Just Pedagogies and Asperger's Syndrome in UK Higher Education

ERIC Educational Resources Information Center

Madriaga, Manuel; Goodley, Dan

2010-01-01

A year-long longitudinal study was conducted to gain insight into the lives of eight students who had a label of Asperger's syndrome during their transitions into higher education in the UK. Reflecting on life history data, the findings suggest that universities might actually be maintaining and (re)producing barriers that perpetuate the exclusion…

Aerodynamic Design of Axial-flow Compressors. Volume 2

NASA Technical Reports Server (NTRS)

1956-01-01

Available experimental two-dimensional-cascade data for conventional compressor blade sections are correlated. The two-dimensional cascade and some of the principal aerodynamic factors involved in its operation are first briefly described. Then the data are analyzed by examining the variation of cascade performance at a reference incidence angle in the region of minimum loss. Variations of reference incidence angle, total-pressure loss, and deviation angle with cascade geometry, inlet Mach number, and Reynolds number are investigated. From the analysis and the correlations of the available data, rules and relations are evolved for the prediction of the magnitude of the reference total-pressure loss and the reference deviation and incidence angles for conventional blade profiles. These relations are developed in simplified forms readily applicable to compressor design procedures.

Low-loss and single-mode tapered hollow-core waveguides optically coupled with interband and quantum cascade lasers

NASA Astrophysics Data System (ADS)

Giglio, Marilena; Patimisco, Pietro; Sampaolo, Angelo; Kriesel, Jason M.; Tittel, Frank K.; Spagnolo, Vincenzo

2018-01-01

We report single-mode midinfrared laser beam delivery through a 50-cm-long tapered hollow-core waveguide (HCW) having bore diameter linearly increasing from 200 to 260 μm. We performed theoretical calculations to identify the best HCW-laser coupling conditions in terms of optical losses and single-mode fiber output. To validate our modeling, we coupled the HCW with an interband cascade laser and four quantum cascade lasers with their emission wavelengths spanning 3.5 to 7.8 μm, using focusing lenses with different focal lengths. With the best coupling conditions, we achieved single-mode output in the investigated 3.5 to 7.8 μm spectral range, with minimum transmission losses of 1.27 dB at 6.2 μm.

On variable hydrostatic transmission for road vehicles, powered by supply of fluid at constant pressure

NASA Technical Reports Server (NTRS)

Magi, M.; Freivald, A.; Andersson, I.; Ericsson, U.

1981-01-01

Various hydrostatic power transmission systems for automotive applications with power supply at constant pressure and unrestricted flow and with a Volvo Flygmotor variable displacement motor as the principal unit were investigated. Two most promising concepts were analyzed in detail and their main components optimized for minimum power loss at the EPA Urban Driving Cycle. The best fuel consumption is less than 10 lit. per 100 kM for a 1542 kG vehicle with a hydrostatic motor and a two speed gear box in series (braking power not recovered). Realistic system pressure affects the fuel consumption just slightly, but the package volume/weight drastically. Back pressure increases losses significantly. Special attention was paid to description of the behavior and modeling of the losses of variable displacement hydrostatic machines.

Contribution of urban expansion and a changing climate to decline of a butterfly fauna.

PubMed

Casner, Kayce L; Forister, Matthew L; O'Brien, Joshua M; Thorne, James; Waetjen, David; Shapiro, Arthur M

2014-06-01

Butterfly populations are naturally patchy and undergo extinctions and recolonizations. Analyses based on more than 2 decades of data on California's Central Valley butterfly fauna show a net loss in species richness through time. We analyzed 22 years of phenological and faunistic data for butterflies to investigate patterns of species richness over time. We then used 18-22 years of data on changes in regional land use and 37 years of seasonal climate data to develop an explanatory model. The model related the effects of changes in land-use patterns, from working landscapes (farm and ranchland) to urban and suburban landscapes, and of a changing climate on butterfly species richness. Additionally, we investigated local trends in land use and climate. A decline in the area of farmland and ranchland, an increase in minimum temperatures during the summer and maximum temperatures in the fall negatively affected net species richness, whereas increased minimum temperatures in the spring and greater precipitation in the previous summer positively affected species richness. According to the model, there was a threshold between 30% and 40% working-landscape area below which further loss of working-landscape area had a proportionally greater effect on butterfly richness. Some of the isolated effects of a warming climate acted in opposition to affect butterfly richness. Three of the 4 climate variables that most affected richness showed systematic trends (spring and summer mean minimum and fall mean maximum temperatures). Higher spring minimum temperatures were associated with greater species richness, whereas higher summer temperatures in the previous year and lower rainfall were linked to lower richness. Patterns of land use contributed to declines in species richness (although the pattern was not linear), but the net effect of a changing climate on butterfly richness was more difficult to discern. © 2014 Society for Conservation Biology.

Biomechanical comparison of two intraoperative mobilization techniques for maxillary distraction osteogenesis: Down-fracture versus non-down-fracture

PubMed Central

Yang, Lili; Suzuki, Eduardo Yugo; Suzuki, Boonsiva

2014-01-01

Purposes: The purpose of this study was to compare the distraction forces and the biomechanical effects between two different intraoperative surgical procedures (down-fracture [DF] and non-DF [NDF]) for maxillary distraction osteogenesis. Materials and Methods: Eight patients were assigned into two groups according to the surgical procedure: DF, n = 6 versus NDF, n = 2. Lateral cephalograms taken preoperatively (T1), immediately after removal of the distraction device (T2), and after at least a 6 months follow-up period (T3) were analyzed. Assessment of distraction forces was performed during the distraction period. The Mann–Whitney U-test was used to compare the difference in the amount of advancement, the maximum distraction force and the amount of relapse. Results: Although a significantly greater amount of maxillary movement was observed in the DF group (median 9.5 mm; minimum-maximum 7.9-14.1 mm) than in the NDF group (median 5.9 mm; minimum-maximum 4.4-7.6 mm), significantly lower maximum distraction forces were observed in the DF (median 16.4 N; minimum-maximum 15.1-24.6 N) than in the NDF (median 32.9 N; minimum-maximum 27.6-38.2 N) group. A significantly greater amount of dental anchorage loss was observed in the NDF group. Moreover, the amount of relapse observed in the NDF group was approximately 3.5 times greater than in the DF group. Conclusions: In this study, it seemed that, the use of the NDF procedure resulted in lower levels of maxillary mobility at the time of the maxillary distraction, consequently requiring greater amounts of force to advance the maxillary bone. Moreover, it also resulted in a reduced amount of maxillary movement, a greater amount of dental anchorage loss and poor treatment stability. PMID:25593865

Ammonium and nitrite oxidation at nanomolar oxygen concentrations in oxygen minimum zone waters

PubMed Central

Bristow, Laura A.; Dalsgaard, Tage; Tiano, Laura; Mills, Daniel B.; Bertagnolli, Anthony D.; Wright, Jody J.; Hallam, Steven J.; Ulloa, Osvaldo; Canfield, Donald E.; Revsbech, Niels Peter; Thamdrup, Bo

2016-01-01

A major percentage of fixed nitrogen (N) loss in the oceans occurs within nitrite-rich oxygen minimum zones (OMZs) via denitrification and anammox. It remains unclear to what extent ammonium and nitrite oxidation co-occur, either supplying or competing for substrates involved in nitrogen loss in the OMZ core. Assessment of the oxygen (O2) sensitivity of these processes down to the O2 concentrations present in the OMZ core (<10 nmol⋅L−1) is therefore essential for understanding and modeling nitrogen loss in OMZs. We determined rates of ammonium and nitrite oxidation in the seasonal OMZ off Concepcion, Chile at manipulated O2 levels between 5 nmol⋅L−1 and 20 μmol⋅L−1. Rates of both processes were detectable in the low nanomolar range (5–33 nmol⋅L−1 O2), but demonstrated a strong dependence on O2 concentrations with apparent half-saturation constants (Kms) of 333 ± 130 nmol⋅L−1 O2 for ammonium oxidation and 778 ± 168 nmol⋅L−1 O2 for nitrite oxidation assuming one-component Michaelis–Menten kinetics. Nitrite oxidation rates, however, were better described with a two-component Michaelis–Menten model, indicating a high-affinity component with a Km of just a few nanomolar. As the communities of ammonium and nitrite oxidizers were similar to other OMZs, these kinetics should apply across OMZ systems. The high O2 affinities imply that ammonium and nitrite oxidation can occur within the OMZ core whenever O2 is supplied, for example, by episodic intrusions. These processes therefore compete with anammox and denitrification for ammonium and nitrite, thereby exerting an important control over nitrogen loss. PMID:27601665

Effect of Variable Spatial Scales on USLE-GIS Computations

NASA Astrophysics Data System (ADS)

Patil, R. J.; Sharma, S. K.

2017-12-01

Use of appropriate spatial scale is very important in Universal Soil Loss Equation (USLE) based spatially distributed soil erosion modelling. This study aimed at assessment of annual rates of soil erosion at different spatial scales/grid sizes and analysing how changes in spatial scales affect USLE-GIS computations using simulation and statistical variabilities. Efforts have been made in this study to recommend an optimum spatial scale for further USLE-GIS computations for management and planning in the study area. The present research study was conducted in Shakkar River watershed, situated in Narsinghpur and Chhindwara districts of Madhya Pradesh, India. Remote Sensing and GIS techniques were integrated with Universal Soil Loss Equation (USLE) to predict spatial distribution of soil erosion in the study area at four different spatial scales viz; 30 m, 50 m, 100 m, and 200 m. Rainfall data, soil map, digital elevation model (DEM) and an executable C++ program, and satellite image of the area were used for preparation of the thematic maps for various USLE factors. Annual rates of soil erosion were estimated for 15 years (1992 to 2006) at four different grid sizes. The statistical analysis of four estimated datasets showed that sediment loss dataset at 30 m spatial scale has a minimum standard deviation (2.16), variance (4.68), percent deviation from observed values (2.68 - 18.91 %), and highest coefficient of determination (R2 = 0.874) among all the four datasets. Thus, it is recommended to adopt this spatial scale for USLE-GIS computations in the study area due to its minimum statistical variability and better agreement with the observed sediment loss data. This study also indicates large scope for use of finer spatial scales in spatially distributed soil erosion modelling.

Optimization of HTST process parameters for production of ready-to-eat potato-soy snack.

PubMed

Nath, A; Chattopadhyay, P K; Majumdar, G C

2012-08-01

Ready-to-eat (RTE) potato-soy snacks were developed using high temperature short time (HTST) air puffing process and the process was found to be very useful for production of highly porous and light texture snack. The process parameters considered viz. puffing temperature (185-255 °C) and puffing time (20-60 s) with constant initial moisture content of 36.74% and air velocity of 3.99 m.s(-1) for potato-soy blend with varying soy flour content from 5% to 25% were investigated using response surface methodology following central composite rotatable design (CCRD). The optimum product in terms of minimum moisture content (11.03% db), maximum expansion ratio (3.71), minimum hardness (2,749.4 g), minimum ascorbic acid loss (9.24% db) and maximum overall acceptability (7.35) were obtained with 10.0% soy flour blend in potato flour at the process conditions of puffing temperature (231.0 °C) and puffing time (25.0 s).

Microwave absorbing properties and enhanced infrared reflectance of Fe/Cu composites prepared by chemical plating

NASA Astrophysics Data System (ADS)

Li, Xiaoguang; Ji, Guangbin; Lv, Hualiang; Wang, Min; Du, Youwei

2014-04-01

Fe/Cu composite samples with Cu particles depositing on carbonyl iron sheets were prepared by chemical plating. Cu additions were uniformly distributed on the grain boundaries of the flaky carbonyl iron while keeping the internal structure of iron. Meanwhile, we found that the chemical plating time made a key point on both the microwave absorbing properties and infrared emissivity. With the growth of chemical plating time, the value of reflection loss gives a linear decrease and the infrared emissivity is reduced with a tendency of index reduction. When the plating time is less than 30 min, the reflection loss of the samples maintains above -20 GHz, moreover, prolonging the plating time more than 30 min, the infrared emissivity of the samples is reduced to 0.50 or less. It can be concluded that both the microwave absorbing and infrared properties are excellent at the optimal plating time of 30 min.

Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties

DOEpatents

Pipino, Andrew Charles Rule

1999-11-16

An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties

DOEpatents

Pipino, Andrew C. R.; Hudgens, Jeffrey W.

1999-08-24

An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

Summer 2007 and 2008 Arctic Sea Ice Loss in Context: OUTLOOK 2008

NASA Astrophysics Data System (ADS)

Overland, J. E.; Eicken, H.; Wiggins, H. V.

2008-12-01

The Arctic is changing faster than the publication cycle for new information. In response, the SEARCH and DAMOCLES Programs initiated an OUTLOOK 2008 to provide broad-based communication and assessment within the arctic science community on the causes of rapid summer sea ice loss, synthesizing information from Arctic observing networks and model simulations. The question for summer 2008 was whether the previous loss of multi-year sea ice and delay in sea ice formation in autumn 2007 would still allow sufficient winter growth of sea ice thickness to last through the summer 2008, potentially allowing for recovery from the 2007 minimum. The answer is no; summer 2008 was a second sequential year of extremely low minimum sea ice extent. To organize OUTLOOK 2008, respondents were asked in May, June and July to provide a rationale and semi-quantitative assessment of arctic sea ice extent anticipated for September 2008. OUTLOOK 2008 supplemented information maintained by ice centers, universities and other data providers. Using a range of methods, all of the approximately 20 groups responded that summer sea ice would not return to climatological mean conditions, with a median response near the 2007 extent. The range of responses depended on the relative weight given to "initial conditions," e.g., age and thickness of sea ice at the end of spring, versus whether summer winds in 2008 would be as supportive for ice loss as in 2007. Initial conditions turned out to be a primary factor for summer 2008, with implications for continued sea ice loss in future years. OUTLOOK 2008 highlighted aspects of the observation and modeling efforts that require further attention such as interpretation of summer microwave signatures, in situ buoy measurements, and data assimilation in models. We appreciate the contributions from respondents and reviewers who made OUTLOOK 2008 a success.

Evaluation of damping loss factor of flat laminates by sound transmission

NASA Astrophysics Data System (ADS)

Parrinello, A.; Ghiringhelli, G. L.

2018-06-01

A novel approach to investigate and evaluate the damping loss factor of a planar multilayered structure is presented. A statistical analysis reveals the connection between the damping properties of the structure and the transmission of sound through the thickness of its laterally infinite counterpart. The obtained expression for the panel loss factor involves all the derivatives of the transmission and reflection coefficients of the layered structure with respect each layer damping. The properties of the fluid for which the sound transmission is evaluated are chosen to fulfil the hypotheses on the basis of the statistical formulation. A transfer matrix approach is used to compute the required transmission and reflection coefficients, making it possible to deal with structures having arbitrary stratifications of different layers and also granting high efficiency in a wide frequency range. Comparison with alternative formulations and measurements demonstrates the effectiveness of the proposed methodology.