Integration of apple rootstock genotype with reduced Brassica seed meal application rates for replant disease control

USDA-ARS?s Scientific Manuscript database

Pre-plant soil application of Brassica seed meal (SM) formulations can provide fumigant level control of apple replant disease. However, due to high cost of the SM treatment relative to non-tarped soil fumigation, reduced application rates would likely accelerate commercial adoption of this technolo...

Community College Business Faculty Recruitment: Association between Personal Characteristics and Applicants' Rating of the Job.

ERIC Educational Resources Information Center

Winter, Paul A.; Munoz, Marco A.

2001-01-01

Describes a study that addressed the association between personal characteristics and job ratings of applicants for business faculty positions described in simulated recruitment advertisements. Finds that being single and working a high number of hours per week were associated with applicant attraction to business faculty positions at community…

Application to College: A Comparison of Asian American and White High School Students.

ERIC Educational Resources Information Center

Goyette, Kimberly

This paper explores an important component of the high college enrollment of Asian American students: application to college while in high school. Using data from the 1988-1992 waves of the National Educational Longitudinal Study (NELS), rates of application to college are compared for Asian Americans and Whites and various Asian American ethnic…

[Effects of nitrogen fertilizer application rate on nitrogen use efficiency and grain yield and quality of different rice varieties].

PubMed

Cong, Xi Han; Shi, Fu Zhi; Ruan, Xin Min; Luo, Yu Xiang; Ma, Ting Chen; Luo, Zhi Xiang

2017-04-18

To provide scientific basis for reasonable application of nitrogen and create varieties with high N use-efficiency, an experiment was carried out to study the effects of nitrogen fertilizer application rate on grain yield, N use rate and quality of different rice varieties. Four different genotypic rice varieties, Nipponbare, N70, N178 and OM052 were used as tested material and three levels of nitrogen application rate (0, 120, 270 kg·hm -2 ) were conducted. Urea as nitrogen source was applied as basal (70%) and panicle (30%) fertilizer. The results showed that nitrogen fertilizer could raise yield mainly because of the increased effective panicles and filled grains per panicle. When the N application rate was 120 and 270 kg·hm -2 , OM052 had the largest grain yield among four varieties, being 41.1% and 76.8% higher, respectively compared with control. Difference in grain yield among four varieties was due to the difference of nitrogen use efficiency. Under 120 and 270 kg·hm -2 nitrogen levels, Nipponbare had the lowest grain yield and N agronomic efficiency (NAE, 40.90 g·g -1 and 18.56 g·g -1 ), which was a variety with low N use-efficiency. On the contrary, OM052 had the highest grain yield and NAE (145.9 g·g -1 and 81.24 g·g -1 ), was a variety with high N use-efficiency. N fertilizer application increased the amylose content and protein content, lengthened gel consistency, reduced chalky kernel, chalkiness, and alkali digestion value. With the increase of N fertilizer application, hot paste viscosity, peak viscosity, consistence viscosity and breakdown viscosity were decreased gradually, and setback viscosity was increased. Correlation analysis showed that the yield and yield components had more significant correlations with appearance quality, cooking and eating quality under low N level. This study confirmed that OM052 was a double high variety with extremely high N agronomic efficiency and yield. Reasonable application of nitrogen fertilizer could significantly increase effective panicles and filled grains per panicle, improve rice quality, and ensure high yield and superior quality simultaneously.

Increase of As release and phytotoxicity to rice seedlings in As-contaminated paddy soils by Si fertilizer application.

PubMed

Lee, Chia-Hsing; Huang, Hsuan-Han; Syu, Chien-Hui; Lin, Tzu-Huei; Lee, Dar-Yuan

2014-07-15

Silicon (Si) was shown to be able to reduce arsenic (As) uptake by rice in hydroponic culture or in low As soils using high Si application rates. However, the effect of Si application on As uptake of rice grown in As-contaminated soils using Si fertilizer recommendation rate has not been investigated. In this study, the effect of Si application using Si fertilizer recommendation rate on As release and phytotoxicity in soils with different properties and contents of As was examined. The results show that the concentrations of As in soil solutions increased after Si applications due to competitive adsorption between As and Si on soil solids and the Si concentrations in soil solutions were also elevated to beneficial levels for rice growth. The rice seedlings accumulated more As and its growth was inhibited by Si application in As contaminated/spiked soils. The results indicate that there is an initial aggravation in As toxicity before the beneficial effects of Si fertilizing to rice were revealed when Si application based on fertilizer recommendation rate to As-contaminated paddy soils. Therefore, for As-contaminated paddy soils with high levels of As, the application of Si fertilizer could result in increasing As phytotoxicity and uptake by rice. Copyright © 2014 Elsevier B.V. All rights reserved.

Response of seed tocopherols in oilseed rape to nitrogen fertilizer sources and application rates* #

PubMed Central

Hussain, Nazim; Li, Hui; Jiang, Yu-xiao; Jabeen, Zahra; Shamsi, Imran Haider; Ali, Essa; Jiang, Li-xi

2014-01-01

Tocopherols (Tocs) are vital scavengers of reactive oxygen species (ROS) and important seed oil quality indicators. Nitrogen (N) is one of the most important fertilizers in promoting biomass and grain yield in crop production. However, the effect of different sources and application rates of N on seed Toc contents in oilseed rape is poorly understood. In this study, pot trials were conducted to evaluate the effect of two sources of N fertilizer (urea and ammonium nitrate). Each source was applied to five oilseed rape genotypes (Zheshuang 72, Jiu-Er-1358, Zheshuang 758, Shiralee, and Pakola) at three different application rates (0.41 g/pot (N1), 0.81 g/pot (N2), and 1.20 g/pot (N3)). Results indicated that urea increased α-, γ-, and total Toc (T-Toc) more than did ammonium nitrate. N3 was proven as the most efficient application rate, which yielded high contents of γ-Toc and T-Toc. Highly significant correlations were observed between Toc isomers, T-Toc, and α-/γ-Toc ratio. These results clearly demonstrate that N sources and application rates significantly affect seed Toc contents in oilseed rape. PMID:24510711

A multi-purpose readout electronics for CdTe and CZT detectors for x-ray imaging applications

NASA Astrophysics Data System (ADS)

Yue, X. B.; Deng, Z.; Xing, Y. X.; Liu, Y. N.

2017-09-01

A multi-purpose readout electronics based on the DPLMS digital filter has been developed for CdTe and CZT detectors for X-ray imaging applications. Different filter coefficients can be synthesized optimized either for high energy resolution at relatively low counting rate or for high rate photon-counting with reduced energy resolution. The effects of signal width constraints, sampling rate and length were numerical studied by Mento Carlo simulation with simple CRRC shaper input signals. The signal width constraint had minor effect and the ENC was only increased by 6.5% when the signal width was shortened down to 2 τc. The sampling rate and length depended on the characteristic time constants of both input and output signals. For simple CR-RC input signals, the minimum number of the filter coefficients was 12 with 10% increase in ENC when the output time constant was close to the input shaping time. A prototype readout electronics was developed for demonstration, using a previously designed analog front ASIC and a commercial ADC card. Two different DPLMS filters were successfully synthesized and applied for high resolution and high counting rate applications respectively. The readout electronics was also tested with a linear array CdTe detector. The energy resolutions of Am-241 59.5 keV peak were measured to be 6.41% in FWHM for the high resolution filter and to be 13.58% in FWHM for the high counting rate filter with 160 ns signal width constraint.

The fates of 15N-labeled fertilizer in a wheat-soil system as influenced by fertilization practice in a loamy soil

NASA Astrophysics Data System (ADS)

Chen, Zhaoming; Wang, Huoyan; Liu, Xiaowei; Lu, Dianjun; Zhou, Jianmin

2016-10-01

Appropriate fertilization practice is crucial to achieve maximum wheat grain yield with minimum nitrogen (N) loss. A field 15N micro-plot experiment was conducted to determine the effects of application methods [split application (SA) and band application (BA)] and N rates (60, 150 and 240 kg ha-1) on the wheat grain yield, urea-15N fate and N efficiency in Jiangyan County, China. At high N rates, wheat grain yield was significantly higher for SA than BA treatment, but there was no difference at the lower N rates. Plant N derived from fertilizer was higher in SA than in BA treatment. The high N fertilizer application increased total N uptake by wheat derived from fertilizer, but wheat plant N derived from soil was not affected by the N rate. Fertilizer-N recovery in SA treatment was higher than in BA treatment. Residual N recovery in the 0-80 cm soil layer was 31-51%, which decreased with increasing N rate. The highest N loss was found for BA treatment at the N application of 240 kg ha-1. The one-time BA of N fertilizer, especially for higher N rates, led to reduced wheat grain yield and N efficiency, and increased the N loss.

Error Rate Comparison during Polymerase Chain Reaction by DNA Polymerase

DOE PAGES

McInerney, Peter; Adams, Paul; Hadi, Masood Z.

2014-01-01

As larger-scale cloning projects become more prevalent, there is an increasing need for comparisons among high fidelity DNA polymerases used for PCR amplification. All polymerases marketed for PCR applications are tested for fidelity properties (i.e., error rate determination) by vendors, and numerous literature reports have addressed PCR enzyme fidelity. Nonetheless, it is often difficult to make direct comparisons among different enzymes due to numerous methodological and analytical differences from study to study. We have measured the error rates for 6 DNA polymerases commonly used in PCR applications, including 3 polymerases typically used for cloning applications requiring high fidelity. Error ratemore » measurement values reported here were obtained by direct sequencing of cloned PCR products. The strategy employed here allows interrogation of error rate across a very large DNA sequence space, since 94 unique DNA targets were used as templates for PCR cloning. The six enzymes included in the study, Taq polymerase, AccuPrime-Taq High Fidelity, KOD Hot Start, cloned Pfu polymerase, Phusion Hot Start, and Pwo polymerase, we find the lowest error rates with Pfu , Phusion, and Pwo polymerases. Error rates are comparable for these 3 enzymes and are >10x lower than the error rate observed with Taq polymerase. Mutation spectra are reported, with the 3 high fidelity enzymes displaying broadly similar types of mutations. For these enzymes, transition mutations predominate, with little bias observed for type of transition.« less

Integration of image capture and processing: beyond single-chip digital camera

NASA Astrophysics Data System (ADS)

Lim, SukHwan; El Gamal, Abbas

2001-05-01

An important trend in the design of digital cameras is the integration of capture and processing onto a single CMOS chip. Although integrating the components of a digital camera system onto a single chip significantly reduces system size and power, it does not fully exploit the potential advantages of integration. We argue that a key advantage of integration is the ability to exploit the high speed imaging capability of CMOS image senor to enable new applications such as multiple capture for enhancing dynamic range and to improve the performance of existing applications such as optical flow estimation. Conventional digital cameras operate at low frame rates and it would be too costly, if not infeasible, to operate their chips at high frame rates. Integration solves this problem. The idea is to capture images at much higher frame rates than he standard frame rate, process the high frame rate data on chip, and output the video sequence and the application specific data at standard frame rate. This idea is applied to optical flow estimation, where significant performance improvements are demonstrate over methods using standard frame rate sequences. We then investigate the constraints on memory size and processing power that can be integrated with a CMOS image sensor in a 0.18 micrometers process and below. We show that enough memory and processing power can be integrated to be able to not only perform the functions of a conventional camera system but also to perform applications such as real time optical flow estimation.

Mode-locked thin-disk lasers and their potential application for high-power terahertz generation

NASA Astrophysics Data System (ADS)

Saraceno, Clara J.

2018-04-01

The progress achieved in the last few decades in the performance of ultrafast laser systems with high average power has been tremendous, and continues to provide momentum to new exciting applications, both in scientific research and technology. Among the various technological advances that have shaped this progress, mode-locked thin-disk oscillators have attracted significant attention as a unique technology capable of providing ultrashort pulses with high energy (tens to hundreds of microjoules) and at very high repetition rates (in the megahertz regime) from a single table-top oscillator. This technology opens the door to compact high repetition rate ultrafast sources spanning the entire electromagnetic spectrum from the XUV to the terahertz regime, opening various new application fields. In this article, we focus on their unexplored potential as compact driving sources for high average power terahertz generation.

A forward error correction technique using a high-speed, high-rate single chip codec

NASA Astrophysics Data System (ADS)

Boyd, R. W.; Hartman, W. F.; Jones, Robert E.

The authors describe an error-correction coding approach that allows operation in either burst or continuous modes at data rates of multiple hundreds of megabits per second. Bandspreading is low since the code rate is 7/8 or greater, which is consistent with high-rate link operation. The encoder, along with a hard-decision decoder, fits on a single application-specific integrated circuit (ASIC) chip. Soft-decision decoding is possible utilizing applique hardware in conjunction with the hard-decision decoder. Expected coding gain is a function of the application and is approximately 2.5 dB for hard-decision decoding at 10-5 bit-error rate with phase-shift-keying modulation and additive Gaussian white noise interference. The principal use envisioned for this technique is to achieve a modest amount of coding gain on high-data-rate, bandwidth-constrained channels. Data rates of up to 300 Mb/s can be accommodated by the codec chip. The major objective is burst-mode communications, where code words are composed of 32 n data bits followed by 32 overhead bits.

In situ assessment of pesticide genotoxicity in an integrated pest management program: II. Maize waxy mutation assay.

PubMed

Rodrigues, G S; Pimentel, D; Weinstein, L H

1998-02-13

The mutagenicity induced by pesticides applied in an integrated pest management (IPM) program was evaluated in situ with the maize forward waxy mutation bioassay. Three pesticide application rates were prescribed as follows: (1) Low--no field pesticide spray; (2) Medium--IPM test rate: banded cyanazine plus metolachlor (2.7 kg a.i. and 2.3 l a.i./ha of herbicides, respectively); and (3) High--a preventative pesticide application program: broadcast cyanazine plus metolachlor (same application rates as above) plus chlorpyrifos (1 kg a.i./ha of insecticide). In general, there was no significant reduction in the genotoxic effects from the high to the medium treatment levels of the IPM program. This suggests that the reduction in pesticide application rates attained with the implementation of the proposed IPM program was not sufficient to abate the genotoxicity of the pesticides. The results indicate that replacing genotoxic compounds may be the only effective remediation measure if concern about environmental mutagenesis were to result in changes in agricultural management.

High-rate RTK and PPP multi-GNSS positioning for small-scale dynamic displacements monitoring

NASA Astrophysics Data System (ADS)

Paziewski, Jacek; Sieradzki, Rafał; Baryła, Radosław; Wielgosz, Pawel

2017-04-01

The monitoring of dynamic displacements and deformations of engineering structures such as buildings, towers and bridges is of great interest due to several practical and theoretical reasons. The most important is to provide information required for safe maintenance of the constructions. High temporal resolution and precision of GNSS observations predestine this technology to be applied to most demanding application in terms of accuracy, availability and reliability. GNSS technique supported by appropriate processing methodology may meet the specific demands and requirements of ground and structures monitoring. Thus, high-rate multi-GNSS signals may be used as reliable source of information on dynamic displacements of ground and engineering structures, also in real time applications. In this study we present initial results of application of precise relative GNSS positioning for detection of small scale (cm level) high temporal resolution dynamic displacements. Methodology and algorithms applied in self-developed software allowing for relative positioning using high-rate dual-frequency phase and pseudorange GPS+Galileo observations are also given. Additionally, an approach was also made to use the Precise Point Positioning technique to such application. In the experiment were used the observations obtained from high-rate (20 Hz) geodetic receivers. The dynamic displacements were simulated using specially constructed device moving GNSS antenna with dedicated amplitude and frequency. The obtained results indicate on possibility of detection of dynamic displacements of the GNSS antenna even at the level of few millimetres using both relative and Precise Point Positioning techniques after suitable signals processing.

Characterization of Metakaolin-Based Geopolymer (Briefing chart)

DTIC Science & Technology

2014-08-31

High Strain Rate Dynamic Characterization of Metakaolin and Fly Ash Bsed Geopolymers for Structural Applications The concrete community has...mechanical properties and microstructure of metakaolin geopolymer , obtain the static properties of metakaolin geopolymer for high strain rate Hopkinson...U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Metakaolin, fly ash, geopolymer , characterization, high strain rate

Sprayable microencapsulated sex pheromone formulations for mating disruption of four tortricid species: effects of application height, rate, frequency, and sticker adjuvant.

PubMed

Stelinski, L L; McGhee, P; Haas, M; Il'ichev, A L; Gut, L J

2007-08-01

Several application parameters of microencapsulated (MEC) sex pheromone formulations were manipulated to determine their impact on efficacy of disruption for codling moth, Cydia pomonella (L.); oriental fruit moth, Grapholita molesta (Busck); obliquebanded leafroller, Choristoneura rosaceana (Harris); and redbanded leafroller, Argyrotaenia velutinana (Walker). Depending on the experiment, the formulations evaluated were those formerly manufactured by 3M Canada (London, ON, Canada) or those that are currently available from Suterra LLC (Bend, OR). The efficacy of MEC formulations applied by air-blast sprayer evenly throughout the entire canopy of 2-3-m-tall apple (Malus spp.) trees was equivalent to treatments in which targeted applications of MECs were made to the lower or upper 1.5 m of the canopy (at equivalent overall rates) for oriental fruit moth and both leafroller species. The realized distribution of deposited microcapsules within the tree canopy corresponded well with the intended heights of application within the canopy. The additional coapplication of the pine resin sticker Nu-Film 17 increased efficacy but not longevity of MEC formulations for oriental fruit moth; this adjuvant had no added effects for codling moth or leafroller formulations. Increasing the rate of active ingredient (AI) per hectare by 20-30-fold (range 2.5-75.0 g/ha) did not improve the disruption efficacy of MECs for codling moth or either leafroller species when both low and high rates were applied at equivalent frequencies per season. A low-rate, high-frequency (nine applications per season) application protocol was compared with a standard protocol in which two to three applications were made per season, once before each moth generation for each species. The low-rate, high-frequency protocol resulted in equivalent or better disruption efficacy for each moth species, despite using two-fold less total AI per hectare per season with the former treatment. The low-rate, frequent-application protocol should make the use of MEC formulations of synthetic pheromone more economical and perhaps more effective.

Variable Thickness Liquid Crystal Films for High Repetition Rate Laser Applications

NASA Astrophysics Data System (ADS)

Poole, Patrick; Willis, Christopher; Cochran, Ginevra; Hanna, Randall; Andereck, C. David; Schumacher, Douglass

2015-05-01

The presentation of a clean target or target substrate at high repetition rates is of importance to a number of photoelectron spectroscopy and free electron laser applications, often in high vacuum environments. Additionally, high intensity laser facilities are approaching the 10 Hz shot rate at petawatt powers, but are currently unable to insert targets at these rates. We have developed liquid crystal films to address this need for high rep rate targets while preserving the planar geometry advantageous to many applications. The molecular ordering of liquid crystal is variable with temperature and can be manipulated to form a layered thin film. In this way temperature and volume control can be used to vary film thickness in vacuo and on-demand between 10 nm and over 10 μm. These techniques were previously applied to a single-shot ion acceleration experiment in, where target thickness critically determines the physics of the acceleration. Here we present an automatic film formation device that utilizes a linear sliding rail to form liquid crystal films within the aforementioned range at rates up to 0.1 Hz. The design ensures film formation location within 2 μm RMS, well within the Rayleigh range of even short f-number systems. Details of liquid crystal films and this target formation device will be shown as well as recent experimental data from the Scarlet laser facility at OSU. This work was supported by DARPA through a grant from AMRDEC.

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

McInerney, Peter; Adams, Paul; Hadi, Masood Z.

As larger-scale cloning projects become more prevalent, there is an increasing need for comparisons among high fidelity DNA polymerases used for PCR amplification. All polymerases marketed for PCR applications are tested for fidelity properties (i.e., error rate determination) by vendors, and numerous literature reports have addressed PCR enzyme fidelity. Nonetheless, it is often difficult to make direct comparisons among different enzymes due to numerous methodological and analytical differences from study to study. We have measured the error rates for 6 DNA polymerases commonly used in PCR applications, including 3 polymerases typically used for cloning applications requiring high fidelity. Error ratemore » measurement values reported here were obtained by direct sequencing of cloned PCR products. The strategy employed here allows interrogation of error rate across a very large DNA sequence space, since 94 unique DNA targets were used as templates for PCR cloning. The six enzymes included in the study, Taq polymerase, AccuPrime-Taq High Fidelity, KOD Hot Start, cloned Pfu polymerase, Phusion Hot Start, and Pwo polymerase, we find the lowest error rates with Pfu , Phusion, and Pwo polymerases. Error rates are comparable for these 3 enzymes and are >10x lower than the error rate observed with Taq polymerase. Mutation spectra are reported, with the 3 high fidelity enzymes displaying broadly similar types of mutations. For these enzymes, transition mutations predominate, with little bias observed for type of transition.« less

Holographic disk with high data transfer rate: its application to an audio response memory.

PubMed

Kubota, K; Ono, Y; Kondo, M; Sugama, S; Nishida, N; Sakaguchi, M

1980-03-15

This paper describes a memory realized with a high data transfer rate using the holographic parallel-processing function and its application to an audio response system that supplies many audio messages to many terminals simultaneously. Digitalized audio messages are recorded as tiny 1-D Fourier transform holograms on a holographic disk. A hologram recorder and a hologram reader were constructed to test and demonstrate the holographic audio response memory feasibility. Experimental results indicate the potentiality of an audio response system with a 2000-word vocabulary and 250-Mbit/sec bit transfer rate.

High frequency ultrasound: a new frontier for ultrasound.

PubMed

Shung, K; Cannata, Jonathan; Qifa Zhou, Member; Lee, Jungwoo

2009-01-01

High frequency ultrasonic imaging is considered by many to be the next frontier in ultrasonic imaging because higher frequencies yield much improved spatial resolution by sacrificing the depth of penetration. It has many clinical applications including visualizing blood vessel wall, anterior segments of the eye and skin. Another application is small animal imaging. Ultrasound is especially attractive in imaging the heart of a small animal like mouse which has a size in the mm range and a heart beat rate faster than 600 BPM. A majority of current commercial high frequency scanners often termed "ultrasonic backscatter microscope or UBM" acquire images by scanning single element transducers at frequencies between 50 to 80 MHz with a frame rate lower than 40 frames/s, making them less suitable for this application. High frequency linear arrays and linear array based ultrasonic imaging systems at frequencies higher than 30 MHz are being developed. The engineering of such arrays and development of high frequency imaging systems has been proven to be highly challenging. High frequency ultrasound may find other significant biomedical applications. The development of acoustic tweezers for manipulating microparticles is such an example.

Line-Focused Optical Excitation of Parallel Acoustic Focused Sample Streams for High Volumetric and Analytical Rate Flow Cytometry.

PubMed

Kalb, Daniel M; Fencl, Frank A; Woods, Travis A; Swanson, August; Maestas, Gian C; Juárez, Jaime J; Edwards, Bruce S; Shreve, Andrew P; Graves, Steven W

2017-09-19

Flow cytometry provides highly sensitive multiparameter analysis of cells and particles but has been largely limited to the use of a single focused sample stream. This limits the analytical rate to ∼50K particles/s and the volumetric rate to ∼250 μL/min. Despite the analytical prowess of flow cytometry, there are applications where these rates are insufficient, such as rare cell analysis in high cellular backgrounds (e.g., circulating tumor cells and fetal cells in maternal blood), detection of cells/particles in large dilute samples (e.g., water quality, urine analysis), or high-throughput screening applications. Here we report a highly parallel acoustic flow cytometer that uses an acoustic standing wave to focus particles into 16 parallel analysis points across a 2.3 mm wide optical flow cell. A line-focused laser and wide-field collection optics are used to excite and collect the fluorescence emission of these parallel streams onto a high-speed camera for analysis. With this instrument format and fluorescent microsphere standards, we obtain analysis rates of 100K/s and flow rates of 10 mL/min, while maintaining optical performance comparable to that of a commercial flow cytometer. The results with our initial prototype instrument demonstrate that the integration of key parallelizable components, including the line-focused laser, particle focusing using multinode acoustic standing waves, and a spatially arrayed detector, can increase analytical and volumetric throughputs by orders of magnitude in a compact, simple, and cost-effective platform. Such instruments will be of great value to applications in need of high-throughput yet sensitive flow cytometry analysis.

High dose rate brachytherapy with customized applicators for malignant facial skin lesions.

PubMed

Jumeau, R; Renard-Oldrini, S; Courrech, F; Buchheit, I; Oldrini, G; Vogin, G; Peiffert, D

2016-07-01

Brachytherapy is a well-known treatment in the management of skin tumors. For facial or scalp lesions, applicators have been developed to deliver non-invasive treatment. We present cases treated with customized applicators with high dose rate system. Patients with poor performance status treated for malignant skin lesions of the scalp or the facial skin between 2011 and 2014 were studied. Afterloading devices were chosen between Freiburg(®) Flap, silicone-mold or wax applicators. The clinical target volume (CTV) was created by adding margins to lesions (10mm to 20mm). The dose schedules were 25Gy in five fractions for postoperative lesions, 30Gy in six fractions for exclusive treatments and a single session of 8Gy could be considered for palliative treatments. In 30 months, 11 patients received a treatment for a total of 12 lesions. The median age was 80 years. The median follow-up was 17 months and the 2-year local control rate was 91%. The mean CTV surface was 41.1cm(2) with a mean thickness of 6.1mm. We conceived three wax applicators, used our silicone-mold eight times and the Freiburg(®) Flap one time. We observed only low-grade radiodermitis (grade I: 50%, grade II: 33%), and no high-grade skin toxicity. High dose rate brachytherapy with customized applicators for facial skin and scalp lesions is efficient and safe. It is a good modality to treat complex lesions in patients unfit for invasive treatment. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

The disposal of a lime water treatment residue on soil and spoil material from a coalmine: a glasshouse investigation.

PubMed

Titshall, L W; Hughes, J C; Morris, C D; Zacharias, P J K

2007-01-01

Eragrostis tef (Zucc.), Cenchrus ciliaris L., and Digitaria eriantha Steud. were grown in a soil (Psammentic Haplustalf) and spoil material from a coalmine both treated with a lime water treatment residue (WTR) at rates of 0, 50, 100, 200, and 400 g kg(-1). The yield of the grasses, from the sum of the three harvests, and concentrations of B, Ca, Cu, K, Fe, Mg, Mn, N, Na, P, and Zn in foliage from the second harvest were determined. The yield of grasses grown in the soil decreased exponentially as WTR application increased. The yields of C. ciliaris, D. eriantha, and E. tef (in the 400 g kg(-1) WTR treated soil) decreased by 74.4, 78.7, and 59.8%, respectively, when compared with the control treatments. In the spoil, the yield of E. tef and D. eriantha decreased by 13.6% and and D. eriantha by 23.9%, while an increase was observed for C. ciliaris (45.4%), at the highest WTR application rate. No relationship existed between yield of E. tef and WTR application rate when grown in the spoil, while a weak negative linear relationship (p < 0.05) was found for D. eriantha and a positive linear relationship existed for C. ciliaris. Magnesium concentrations of the grasses were positively correlated to WTR application rate. Grasses grown in the soil had higher Na concentrations, while those grown in the spoil typically had higher B, N, and Zn concentrations. The decreases in yield were attributed to nutrient deficiencies (notably Zn), induced by high WTR application rates that led to high substrate pH. Disposal of high rates of WTR on the mine materials was not recommended.

The consistency of Fletcher-Suit applicator geometry and of the rectal probe’s position in high dose rate brachytherapy treatment fraction of cervix carcinoma

PubMed Central

2009-01-01

Purpose The dose values computed with the treatment planning system and the in vivo dose measurements with semiconductor detectors in rectum during the high dose rate brachytherapy treatment fraction of the cervix carcinoma are occasionally significantly different. We’ve investigated the consistency of the Fletcher-Suit applicator geometry and the in vivo rectal probe’s position stability during the high dose rate brachytherapy treatment fraction. Material and methods The patient lied in a lithotomic position during a biplane reconstruction images, throughout the treatment planning and dose administration. We obtained post-treatment reconstruction images and prepared a post-treatment plan. The amount of 14 treatment fractions of 10 patients were considered in the study. Two methods were applied: evaluation of the difference of reconstructed pre-treatment and post-treatment applicator points and rectal probe’s detectors being relevant to the co-ordinate system fixed to the applicator, and estimation of applicators and rectal probe’s reallocation with respect to the pelvic bones with registration of pre- and post-treatment reconstruction images. Results We’ve experienced good consistency in the Fletcher-Suit applicator geometry in all treatment fractions. 70% of them presented small variation in the rectal probe’s position, while the rest showed significant shift in the applicator or rectal probe’s position with regard to the pelvic bones. PMID:27807458

Long-term effects of different type and rates of organic amendments on reclamation of copper mine tailing in Central Chile.

NASA Astrophysics Data System (ADS)

Arellano, Eduardo; Garreton, Bruna; Ginocchio, Rosanna

2016-04-01

A study was conducted to evaluate the long-term effects of a single application of organic amendments on a copper mine tailings. Seven years after seeding of a mix of herbaceous plant and planting of ten native trees, and the application of organic amendment, plant community and soil fertility was measured in replicated plots that received six different treatments of waste water treatment plant biosolids (100 ton/ha, and 200 ton/ha), olive oil waste (100 ton/ha, and 200 ton/ha) and pisco grapes waste (90 ton/ha, and 200 ton/ha). A control treatment that received no organic amendment was also measured after seven years. Field measurements demonstrated that application of biosolids and pisco grapes waste, at both rates significantly improved vegetation coverage in comparison to the control treatment (80 and 100% vs control, 25%). The high rates of pisco waste had the highest vegetation diversity and survival in comparison to the other treatments. The high rate of olive oil waste had a negative effect on vegetation development in comparison to the control treatment. The application of organic amendment improved soil fertility in the long-term. All the treatments had a significant higher nitrogen concentration in comparison to the control treatment. The high rates of biosolids and pisco grape waste had a significantly effect of soil carbon concentration. Soil macro-aggregate in the high rate of pisco grape waste were also higher than the control, showing a positive relation between soil recover and vegetation development. We can conclude assisted phytostabilization of mine tailings is likely a technically effective solution for the valorisation of organic residues.

White OLED devices and processes for lighting applications

NASA Astrophysics Data System (ADS)

Ide, Nobuhiro; Tsuji, Hiroya; Ito, Norihiro; Matsuhisa, Yuko; Houzumi, Shingo; Nishimori, Taisuke

2010-05-01

In these days, the basic performances of white OLEDs are dramatically improved and application of OLEDs to "Lighting" is expected to be true in the near future. We have developed various technologies for OLED lighting with the aid of the Japanese governmental project, "High-efficiency lighting based on the organic light-emitting mechanism." In this project, a white OLED with high efficiency (37 lm/W) and high quality emission characteristics (CRI of 95 with a small variation of chromaticity in different directions and chromaticity just on the black-body radiation curve) applicable to "Lighting" was realized by a two-unit structure with a fluorescent deep blue emissive unit and a phosphorescent green and red emissive unit. Half-decay lifetime of this white OLED at 1,000 cd/m2 was over 40,000 h. A heat radiative, thin encapsulation structure (less than 1 mm) realized a very stable emission at high luminance of over 3,000 cd/m2. A new deposition source with a hot-wall and a rate controllable valve was developed. Thickness uniformity within +/- 3% at high deposition rate of over 8 nm/s, high material utilization of over 70 %, and repeatable deposition rate controllability were confirmed.

Trade-off between blue and grey water footprint of crop production at different nitrogen application rates under various field management practices.

PubMed

Chukalla, Abebe D; Krol, Maarten S; Hoekstra, Arjen Y

2018-06-01

In irrigated crop production, nitrogen (N) is often applied at high rates in order to maximize crop yield. With such high rates, the blue water footprint (WF) per unit of crop is low, but the N-related grey WF per unit of crop yield is relatively high. This study explores the trade-off between blue and grey WF at different N-application rates (from 25 to 300 kg N ha -1  y -1 ) under various field management practices. We first analyse this trade-off under a reference management package (applying inorganic-N, conventional tillage, full irrigation). Next, we estimate the economically optimal N-application rate when putting a price to pollution. Finally, we consider the blue-grey WF trade-off for other management packages, a combination of inorganic-N or organic-N with conventional tillage or no-tillage, and full or deficit irrigation. We use the APEX model to simulate soil water and N balances and crop growth. As a case study, we consider irrigated maize on loam soil for the period 1998-2012 in a semi-arid environment in Spain. The results for the reference package show that increasing N application from 50 to 200 kg N ha -1 , with crop yield growing by a factor 3, involves a trade-off, whereby the blue WF per tonne declines by 60% but the N-related grey WF increases by 210%. Increasing N application from 25 to 50 kg N ha -1 , with yield increasing by a factor 2, is a no-regret move, because blue and grey WFs per tonne are reduced by 40% and 8%, respectively. Decreasing N application from 300 to 200 kg N ha -1 is a no-regret move as well. The minimum blue WF per tonne is found at N application of 200 kg N ha -1 , with a price of 8 $ kg -1 of N load to water pollution the economically optimal N-application rate is 150 kg N ha -1 . Copyright © 2018 Elsevier B.V. All rights reserved.

Flexible holey graphene paper electrodes with enhanced rate capability for energy storage applications.

PubMed

Zhao, Xin; Hayner, Cary M; Kung, Mayfair C; Kung, Harold H

2011-11-22

The unique combination of high surface area, high electrical conductivity and robust mechanical integrity has attracted great interest in the use of graphene sheets for future electronics applications. Their potential applications for high-power energy storage devices, however, are restricted by the accessible volume, which may be only a fraction of the physical volume, a consequence of the compact geometry of the stack and the ion mobility. Here we demonstrated that remarkably enhanced power delivery can be realized in graphene papers for the use in Li-ion batteries by controlled generation of in-plane porosity via a mechanical cavitation-chemical oxidation approach. These flexible, holey graphene papers, created via facile microscopic engineering, possess abundant ion binding sites, enhanced ion diffusion kinetics, and excellent high-rate lithium-ion storage capabilities, and are suitable for high-performance energy storage devices. © 2011 American Chemical Society

Passive control of temperature excursion and uniformity in high-energy Li-ion battery packs at high current and ambient temperature

NASA Astrophysics Data System (ADS)

Kizilel, R.; Lateef, A.; Sabbah, R.; Farid, M. M.; Selman, J. R.; Al-Hallaj, S.

A strategy for portable high-power applications with a controlled thermal environment has been developed and has demonstrated the advantage of using the novel phase change material (PCM) thermal management systems over conventional active cooling systems. A passive thermal management system using PCM for Li-ion batteries is tested for extreme conditions, such as ambient temperature of 45 °C and discharge rate of 2.08 C-rate (10 A). Contrary to Li-ion packs without thermal management system, high-energy packs with PCM are discharged safely at high currents and degrading rate of capacity of the Li-ion packs lowered by half. Moreover, the compactness of the packs not only decreases the volume occupied by the packs and its associated complex cooling system, but also decreases the total weight for large power application.

HiLASE Project: high intensity lasers for industrial and scientific applications

NASA Astrophysics Data System (ADS)

Rostohar, Danijela; Lucianetti, Antonio; Endo, Akira; Mocek, Tomas

2015-01-01

The Czech national R&D project HiLASE is a platform for development of advance high repetition rate, diode pump solid state lasers (DPSSL) systems with energies in the range from mJ to 10J and repetition rate from 10 Hz to 100 kHz. In this paper an overview and a status of the project will be given. Additionally some applications of these lasers in the hi-tech industry, which initiated their development, will be also presented.

Belt-MRF for large aperture mirrors.

PubMed

Ren, Kai; Luo, Xiao; Zheng, Ligong; Bai, Yang; Li, Longxiang; Hu, Haixiang; Zhang, Xuejun

2014-08-11

With high-determinacy and no subsurface damage, Magnetorheological Finishing (MRF) has become an important tool in fabricating high-precision optics. But for large mirrors, the application of MRF is restricted by its small removal function and low material removal rate. In order to improve the material removal rate, shorten the processing cycle, we proposed a new MRF concept, named Belt-MRF to expand the application of MRF to large mirrors and made a prototype with a large remove function, using a belt instead of a very large polishing wheel to expand the polishing length. A series of experimental results on Silicon carbide (SiC) and BK 7 specimens and fabrication simulation verified that the Belt-MRF has high material removal rates, stable removal function and high convergence efficiency which makes it a promising technology for processing large aperture optical elements.

A New Statistics-Based Online Baseline Restorer for a High Count-Rate Fully Digital System.

PubMed

Li, Hongdi; Wang, Chao; Baghaei, Hossain; Zhang, Yuxuan; Ramirez, Rocio; Liu, Shitao; An, Shaohui; Wong, Wai-Hoi

2010-04-01

The goal of this work is to develop a novel, accurate, real-time digital baseline restorer using online statistical processing for a high count-rate digital system such as positron emission tomography (PET). In high count-rate nuclear instrumentation applications, analog signals are DC-coupled for better performance. However, the detectors, pre-amplifiers and other front-end electronics would cause a signal baseline drift in a DC-coupling system, which will degrade the performance of energy resolution and positioning accuracy. Event pileups normally exist in a high-count rate system and the baseline drift will create errors in the event pileup-correction. Hence, a baseline restorer (BLR) is required in a high count-rate system to remove the DC drift ahead of the pileup correction. Many methods have been reported for BLR from classic analog methods to digital filter solutions. However a single channel BLR with analog method can only work under 500 kcps count-rate, and normally an analog front-end application-specific integrated circuits (ASIC) is required for the application involved hundreds BLR such as a PET camera. We have developed a simple statistics-based online baseline restorer (SOBLR) for a high count-rate fully digital system. In this method, we acquire additional samples, excluding the real gamma pulses, from the existing free-running ADC in the digital system, and perform online statistical processing to generate a baseline value. This baseline value will be subtracted from the digitized waveform to retrieve its original pulse with zero-baseline drift. This method can self-track the baseline without a micro-controller involved. The circuit consists of two digital counter/timers, one comparator, one register and one subtraction unit. Simulation shows a single channel works at 30 Mcps count-rate with pileup condition. 336 baseline restorer circuits have been implemented into 12 field-programmable-gate-arrays (FPGA) for our new fully digital PET system.

High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

NASA Technical Reports Server (NTRS)

Taveniku, Mikael

2013-01-01

A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges. The current generation data recor - ders used within the VLBI community are aging, special-purpose machines that are both slow (do not meet today's requirements) and are very expensive to maintain and operate. Furthermore, they are not easily upgraded to take advantage of commercial technology development, and are not scalable to multiple 10s of Gbit/s data rates required by new applications. The innovation provides a softwaredefined, high-speed data recorder that is scalable with technology advances in the commercial space. It maximally utilizes current technologies without being locked to a particular hardware platform. The innovation also provides a cost-effective way of streaming large amounts of data from sensors to disk, enabling many applications to store raw sensor data and perform post and signal processing offline. This recording system will be applicable to many applications needing realworld, high-speed data collection, including electronic warfare, softwaredefined radar, signal history storage of multispectral sensors, development of autonomous vehicles, and more.

Influence of liquid-volume and airflow rates on spray application quality and homogeneity in super-intensive olive tree canopies.

PubMed

Miranda-Fuentes, Antonio; Rodríguez-Lizana, Antonio; Gil, Emilio; Agüera-Vega, J; Gil-Ribes, Jesús A

2015-12-15

Olive is a key crop in Europe, especially in countries around the Mediterranean Basin. Optimising the parameters of a spray is essential for sustainable pesticide use, especially in high-input systems, such as the super-intensive hedgerow system. Parameters may be optimised by adjusting the applied volume and airflow rate of sprays, in addition to the liquid to air proportion and the relationship between air velocity and airflow rate. Two spray experiments using a commercial airblast sprayer were conducted in a super-intensive orchard to study how varying the liquid volume rate (testing volumes of 182, 619, and 1603 l ha(-1)) and volumetric airflow rate (with flow rates of 11.93, 8.90, and 6.15 m(3) s(-1)) influences the coverage parameters and the amount and distribution of deposits in different zones of the canopy.. Our results showed that an increase in the application volume raised the mean deposit and percentage coverage, but decreased the application efficiency, spray penetration, and deposit homogeneity. Furthermore, we found that the volumetric airflow rate had a lower influence on the studied parameters than the liquid volume; however, an increase in the airflow rate improved the application efficiency and homogeneity to a certain threshold, after which the spray quality decreased. This decrease was observed in the high-flow treatment. Our results demonstrate that intermediate liquid volume rates and volumetric airflow rates are required for the optimal spraying of pesticides on super-intensive olive crops, and would reduce current pollution levels. Copyright © 2015 Elsevier B.V. All rights reserved.

Design of Hydrogen Storage Alloys/Nanoporous Metals Hybrid Electrodes for Nickel-Metal Hydride Batteries.

PubMed

Li, M M; Yang, C C; Wang, C C; Wen, Z; Zhu, Y F; Zhao, M; Li, J C; Zheng, W T; Lian, J S; Jiang, Q

2016-06-07

Nickel metal hydride (Ni-MH) batteries have demonstrated key technology advantages for applications in new-energy vehicles, which play an important role in reducing greenhouse gas emissions and the world's dependence on fossil fuels. However, the poor high-rate dischargeability of the negative electrode materials-hydrogen storage alloys (HSAs) limits applications of Ni-MH batteries in high-power fields due to large polarization. Here we design a hybrid electrode by integrating HSAs with a current collector of three-dimensional bicontinuous nanoporous Ni. The electrode shows enhanced high-rate dischargeability with the capacity retention rate reaching 44.6% at a discharge current density of 3000 mA g(-1), which is 2.4 times that of bare HSAs (18.8%). Such a unique hybrid architecture not only enhances charge transfer between nanoporous Ni and HSAs, but also facilitates rapid diffusion of hydrogen atoms in HSAs. The developed HSAs/nanoporous metals hybrid structures exhibit great potential to be candidates as electrodes in high-performance Ni-MH batteries towards applications in new-energy vehicles.

Design of Hydrogen Storage Alloys/Nanoporous Metals Hybrid Electrodes for Nickel-Metal Hydride Batteries

PubMed Central

Li, M. M.; Yang, C. C.; Wang, C. C.; Wen, Z.; Zhu, Y. F.; Zhao, M.; Li, J. C.; Zheng, W. T.; Lian, J. S.; Jiang, Q.

2016-01-01

Nickel metal hydride (Ni-MH) batteries have demonstrated key technology advantages for applications in new-energy vehicles, which play an important role in reducing greenhouse gas emissions and the world’s dependence on fossil fuels. However, the poor high-rate dischargeability of the negative electrode materials—hydrogen storage alloys (HSAs) limits applications of Ni-MH batteries in high-power fields due to large polarization. Here we design a hybrid electrode by integrating HSAs with a current collector of three-dimensional bicontinuous nanoporous Ni. The electrode shows enhanced high-rate dischargeability with the capacity retention rate reaching 44.6% at a discharge current density of 3000 mA g−1, which is 2.4 times that of bare HSAs (18.8%). Such a unique hybrid architecture not only enhances charge transfer between nanoporous Ni and HSAs, but also facilitates rapid diffusion of hydrogen atoms in HSAs. The developed HSAs/nanoporous metals hybrid structures exhibit great potential to be candidates as electrodes in high-performance Ni-MH batteries towards applications in new-energy vehicles. PMID:27270184

Design of Hydrogen Storage Alloys/Nanoporous Metals Hybrid Electrodes for Nickel-Metal Hydride Batteries

NASA Astrophysics Data System (ADS)

Li, M. M.; Yang, C. C.; Wang, C. C.; Wen, Z.; Zhu, Y. F.; Zhao, M.; Li, J. C.; Zheng, W. T.; Lian, J. S.; Jiang, Q.

2016-06-01

Nickel metal hydride (Ni-MH) batteries have demonstrated key technology advantages for applications in new-energy vehicles, which play an important role in reducing greenhouse gas emissions and the world’s dependence on fossil fuels. However, the poor high-rate dischargeability of the negative electrode materials—hydrogen storage alloys (HSAs) limits applications of Ni-MH batteries in high-power fields due to large polarization. Here we design a hybrid electrode by integrating HSAs with a current collector of three-dimensional bicontinuous nanoporous Ni. The electrode shows enhanced high-rate dischargeability with the capacity retention rate reaching 44.6% at a discharge current density of 3000 mA g-1, which is 2.4 times that of bare HSAs (18.8%). Such a unique hybrid architecture not only enhances charge transfer between nanoporous Ni and HSAs, but also facilitates rapid diffusion of hydrogen atoms in HSAs. The developed HSAs/nanoporous metals hybrid structures exhibit great potential to be candidates as electrodes in high-performance Ni-MH batteries towards applications in new-energy vehicles.

Effect of Silicate Slag Application on Wheat Grown Under Two Nitrogen Rates

PubMed Central

White, Brandon; Tubana, Brenda S.; Babu, Tapasya; Mascagni, Henry; Agostinho, Flavia; Datnoff, Lawrence E.; Harrison, Steve

2017-01-01

Field studies were established on the alluvial floodplain soils in Louisiana, from 2013 to 2015, to evaluate the effect of silicate slag applications on productivity of wheat (Triticum aestivum), under sufficient and high nitrogen (N) application rates. Treatments were arranged in a randomized complete block design, with four replications consisting of twelve treatments: a factorial combination of two N (101 and 145 kg N ha−1) and five silicate slag rates (0, 1, 2, 4.5, and 9 Mg ha−1), and two control plots (with and without lime). Nitrogen had a greater impact on wheat productivity than silicate slag application. Wheat grain yield reached over 7000 kg ha−1 with applications of 145 kg N, and 9 Mg silicate slag per ha for soil having Si level <20 mg kg−1. Yield increases due to N or Si were attributed to the increase in number of spike m−2 and grain number spike−1. Silicate slag application effectively raised soil pH, and availability of several plant-essential nutrients, including plant-available N (nitrate, NO3−), demonstrating the benefits of slag application are beyond increasing plant-available Si. The benefits of silicate slag application were clearly observed in wheat supplied with high N, and on soil with low plant-available Si. PMID:29019922

User Centred Design and Nosocomials in Surgical ICUs: A Mobile Application for Peer Monitoring and Training in Hand Hygiene.

PubMed

Kariyawasam, Nadish; Wong, Ming Chao; Turner, Paul

2017-01-01

Nosocomial infections are a global public health risk. In low and middle-income countries the problem is acute with very high infection rates commonly contributing to poor patient outcomes including mortality. Organisational, cultural, and individual factors have been identified in these high rates, with poor hand hygiene compliance amongst clinicians a major risk factor. New approaches to achieving clinician behaviour change are required. User-centred approaches have proven effective to engage and support changes in clinician behaviours through the use of electronic tools. This paper reports on the experience of co-designing and implementing a mobile application with clinicians to enhance hand hygiene compliance. The peer monitoring and training supported by the application aims to directly contribute to evidence on reductions in infection rates in two surgical ICUs in Sri Lanka.

A study of 60 GHz intersatellite link applications

NASA Technical Reports Server (NTRS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

1983-01-01

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

A study of 60 Gigahertz intersatellite link applications

NASA Astrophysics Data System (ADS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

A study of 60 Gigahertz intersatellite link applications

NASA Technical Reports Server (NTRS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

1983-01-01

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

A study of 60 GHz intersatellite link applications

NASA Astrophysics Data System (ADS)

Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

High-Modulation-Speed LEDs Based on III-Nitride

NASA Astrophysics Data System (ADS)

Chen, Hong

III-nitride InGaN light-emitting diodes (LEDs) enable wide range of applications in solid-state lighting, full-color displays, and high-speed visible-light communication. Conventional InGaN quantum well LEDs grown on polar c-plane substrate suffer from quantum confined Stark effect due to the large internal polarization-related fields, leading to a reduced radiative recombination rate and device efficiency, which limits the performance of InGaN LEDs in high-speed communication applications. To circumvent these negative effects, non-trivial-cavity designs such as flip-chip LEDs, metallic grating coated LEDs are proposed. This oral defense will show the works on the high-modulation-speed LEDs from basic ideas to applications. Fundamental principles such as rate equations for LEDs/laser diodes (LDs), plasmonic effects, Purcell effects will be briefly introduced. For applications, the modal properties of flip-chip LEDs are solved by implementing finite difference method in order to study the modulation response. The emission properties of highly polarized InGaN LEDs coated by metallic gratings are also investigated by finite difference time domain method.

Engineering Fast Ion Conduction and Selective Cation Channels for a High-Rate and High-Voltage Hybrid Aqueous Battery.

PubMed

Liu, Chunyi; Wang, Xusheng; Deng, Wenjun; Li, Chang; Chen, Jitao; Xue, Mianqi; Li, Rui; Pan, Feng

2018-03-14

The rechargeable aqueous metal-ion battery (RAMB) has attracted considerable attention due to its safety, low costs, and environmental friendliness. Yet the poor-performance electrode materials lead to a low feasibility of practical application. A hybrid aqueous battery (HAB) built from electrode materials with selective cation channels could increase the electrode applicability and thus enlarge the application of RAMB. Herein, we construct a high-voltage K-Na HAB based on K 2 FeFe(CN) 6 cathode and carbon-coated NaTi 2 (PO 4 ) 3 (NTP/C) anode. Due to the unique cation selectivity of both materials and ultrafast ion conduction of NTP/C, the hybrid battery delivers a high capacity of 160 mAh g -1 at a 0.5 C rate. Considerable capacity retention of 94.3 % is also obtained after 1000 cycles at even 60 C rate. Meanwhile, high energy density of 69.6 Wh kg -1 based on the total mass of active electrode materials is obtained, which is comparable and even superior to that of the lead acid, Ni/Cd, and Ni/MH batteries. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High resolution, high frame rate video technology development plan and the near-term system conceptual design

NASA Technical Reports Server (NTRS)

Ziemke, Robert A.

1990-01-01

The objective of the High Resolution, High Frame Rate Video Technology (HHVT) development effort is to provide technology advancements to remove constraints on the amount of high speed, detailed optical data recorded and transmitted for microgravity science and application experiments. These advancements will enable the development of video systems capable of high resolution, high frame rate video data recording, processing, and transmission. Techniques such as multichannel image scan, video parameter tradeoff, and the use of dual recording media were identified as methods of making the most efficient use of the near-term technology.

Video-rate or high-precision: a flexible range imaging camera

NASA Astrophysics Data System (ADS)

Dorrington, Adrian A.; Cree, Michael J.; Carnegie, Dale A.; Payne, Andrew D.; Conroy, Richard M.; Godbaz, John P.; Jongenelen, Adrian P. P.

2008-02-01

A range imaging camera produces an output similar to a digital photograph, but every pixel in the image contains distance information as well as intensity. This is useful for measuring the shape, size and location of objects in a scene, hence is well suited to certain machine vision applications. Previously we demonstrated a heterodyne range imaging system operating in a relatively high resolution (512-by-512) pixels and high precision (0.4 mm best case) configuration, but with a slow measurement rate (one every 10 s). Although this high precision range imaging is useful for some applications, the low acquisition speed is limiting in many situations. The system's frame rate and length of acquisition is fully configurable in software, which means the measurement rate can be increased by compromising precision and image resolution. In this paper we demonstrate the flexibility of our range imaging system by showing examples of high precision ranging at slow acquisition speeds and video-rate ranging with reduced ranging precision and image resolution. We also show that the heterodyne approach and the use of more than four samples per beat cycle provides better linearity than the traditional homodyne quadrature detection approach. Finally, we comment on practical issues of frame rate and beat signal frequency selection.

Inhalational and dermal exposures during spray application of biocides.

PubMed

Berger-Preiss, Edith; Boehncke, Andrea; Könnecker, Gustav; Mangelsdorf, Inge; Holthenrich, Dagmar; Koch, Wolfgang

2005-01-01

Data on inhalational and potential dermal exposures during spray application of liquid biocidal products were generated. On the one hand, model experiments with different spraying devices using fluorescent tracers were carried out to investigate the influence of parameters relevant to the exposure (e.g. spraying equipment, nozzle size, direction of application). On the other hand, measurements were performed at selected workplaces (during disinfection operations in food and feed areas; pest control operations for private, public and veterinary hygiene; wood protection and antifouling applications) after application of biocidal products such as Empire 20, Responsar SC, Omexan-forte, Actellic, Perma-forte; Fendona SC, Pyrethrum mist; CBM 8, Aldekol Des 03, TAD CID, Basileum, Basilit. The measurements taken in the model rooms demonstrated dependence of the inhalation exposure on the type of spraying device used, in the following order: "spraying with low pressure" < "airless spraying" < "fogging" indicating that the particle diameter of the released spray droplets is the most important parameter. In addition inhalation exposure was lowest when the spraying direction was downward. Also for the potential dermal exposure, the spraying direction was of particular importance: overhead spraying caused the highest contamination of body surfaces. The data of inhalational and potential dermal exposures gained through workplace measurements showed considerable variation. During spraying procedures with low-pressure equipments, dose rates of active substances inhaled by the operators ranged from 7 to 230 microg active substance (a.s.)/h. An increase in inhaled dose rates (6-33 mg a.s./h) was observed after use of high application volumes/time unit during wood protection applications indoors. Spraying in the veterinary sector using medium-pressure sprayers led to inhaled dose rates between 2 and 24mga.s./h. The highest inhaled dose rates were measured during fogging (114 mg a.s./h) and after-high-pressure applications in the antifouling sector (110-300 mg a.s./h). The potential dermal exposure of spray operators was lowest (dose rates from 0.2 to 7 mg a.s./h) in the areas of food and feed disinfection and private and public hygiene during spraying with low-pressure devices. During fogging, wood protection and antifouling applications, high-potential dermal exposures of the operators were determined. Dermal dose rates varied between 100 and 34,000 mg a.s./h.

Laser communication experiments between Sota and Meo optical ground station

NASA Astrophysics Data System (ADS)

Artaud, G.,; Issler, J.-L.; Védrenne, N.; Robert, C.; Petit, C.; Samain, E.; Phung, D.-H.; Maurice, N.; Toyoshima, M.; Kolev, D.

2017-09-01

Optical transmissions between earth and space have been identified as key technologies for future high data rate transmissions between satellites and ground. CNES is investigating the use of optics both for High data rate direct to Earth transfer from observation satellites in LEO, and for future telecommunications applications using optics for the high capacity Gateway link.

Low-stress PECVD amorphous silicon carbide (α-SiC) layers for biomedical application

NASA Astrophysics Data System (ADS)

Wei, Jiashen; Chen, Bangtao; Poenar, Daniel P.; Lee, Yong Yeow; Iliescu, Ciprian

2008-12-01

A detailed characterization of PECVD to produce low stress amorphous silicon carbide (α-SiC) layers at high deposition rate has been done and the biomedical applications of α-SiC layers are reported in this paper. By investigating different working principles in high-frequency mode (13.56MHz) and in low frequency mode (380KHz), it is found that deposition in high-frequency mode can achieve low stress layers at high deposition rates due to the structural rearrangement from high HF power, rather than the ion bombardment effect from high LF power which results in high compressive stress for α-SiC layers. Furthermore, the effects of deposition temperature, pressure and reactant gas ratios are also investigated and then an optimal process is achieved to produce low stress α-SiC layers with high deposition rates. To characterize the PECVD α-SiC layers from optimized process, a series of wet etching experiments in KOH and HF solutions have been completed. The very low etching rates of PECVD α-SiC layers in these two solutions show the good chemical inertness and suitability for masking layers in micromachining. Moreover, cell culture tests by seeding fibroblast NIH3T3 cells on the monocrystalline SiC, low-stress PECVD α-SiC released membranes and non-released PECVD α-SiC films on silicon substrates have been done to check the feasibility of PECVD α-SiC layers as substrate materials for biomedical applications. The results indicate that PECVD α-SiC layers are good for cell culturing, especially after treated in NH4F.

VO2 nanoparticles on edge orientated graphene foam for high rate lithium ion batteries and supercapacitors

NASA Astrophysics Data System (ADS)

Ren, Guofeng; Zhang, Ruibo; Fan, Zhaoyang

2018-05-01

With the fully exposed graphene edges, high conductivity and large surface area, edge oriented graphene foam (EOGF), prepared by deposition of perpendicular graphene network encircling the struts of Ni foam, is a superior scaffold to support active materials for electrochemical applications. With VO2 as an example, EOGF loaded VO2 nanoparticle (VO2/EOGF) electrode has high rate performance as cathode in lithium ion batteries (LIBs). In addition to the Li+ intercalation into the lattice, contribution of non-diffusion-limited pseudocapacitance to the capacity is prominent at high rates. VO2/EOGF based supercapacitor also exhibits fast response, with a characteristic frequency of 15 Hz when the phase angle reaches -45°, or a relaxation time constant of 66.7 ms. These results suggest the promising potential of EOGF as a scaffold in supporting active nanomaterials for electrochemical energy storage and other applications.

Effects of Nitrogen Application Rate on the Yields, Nutritive Value and Silage Fermentation Quality of Whole-crop Wheat.

PubMed

Li, C J; Xu, Z H; Dong, Z X; Shi, S L; Zhang, J G

2016-08-01

Whole-crop wheat (Triticum aestivum L.) as forage has been extensively used in the world. In this study, the effects of N application rates on the yields, nutritive value and silage quality were investigated. The N application rates were 0, 75, 150, 225, and 300 kg/ha. The research results indicated that the dry matter yield of whole-crop wheat increased significantly with increasing N rate up to 150 kg/ha, and then leveled off. The crude protein content and in vitro dry matter digestibility of whole-crop wheat increased significantly with increasing N up to 225 kg/ha, while they no longer increased at N 300 kg/ha. On the contrary, the content of various fibers tended to decrease with the increase of N application. The content of lactic acid, acetic acid and propionic acid in silages increased with the increase of N rate (p<0.05). The ammonia-N content of silages with higher N application rates (≥225 kg/ha) was significantly higher than that with lower N application rates (≤150 kg/ha). Whole-crop wheat applied with high levels of N accumulated more nitrate-N. In conclusion, taking account of yields, nutritive value, silage quality and safety, the optimum N application to whole-crop wheat should be about 150 kg/ha at the present experiment conditions.

High rate and stable cycling of lithium metal anode

DOE PAGES

Qian, Jiangfeng; Henderson, Wesley A.; Xu, Wu; ...

2015-02-20

Lithium (Li) metal is an ideal anode material for rechargeable batteries. However, dendritic Li growth and limited Coulombic efficiency (CE) during repeated Li deposition/stripping processes have prevented the application of this anode in rechargeable Li metal batteries, especially for use at high current densities. Here, we report that the use of highly concentrated electrolytes composed of ether solvents and the lithium bis(fluorosulfonyl)imide (LiFSI) salt enables the high rate cycling of a Li metal anode at high CE (up to 99.1 %) without dendrite growth. With 4 M LiFSI in 1,2-dimethoxyethane (DME) as the electrolyte, a Li|Li cell can be cycledmore » at high rates (10 mA cm -2) for more than 6000 cycles with no increase in the cell impedance, and a Cu|Li cell can be cycled at 4 mA cm-2 for more than 1000 cycles with an average CE of 98.4%. These excellent high rate performances can be attributed to the increased solvent coordination and increased availability of Li+ concentration in the electrolyte. Lastly, further development of this electrolyte may lead to practical applications for Li metal anode in rechargeable batteries. The fundamental mechanisms behind the high rate ion exchange and stability of the electrolytes also shine light on the stability of other electrochemical systems.« less

Region Templates: Data Representation and Management for High-Throughput Image Analysis

PubMed Central

Pan, Tony; Kurc, Tahsin; Kong, Jun; Cooper, Lee; Klasky, Scott; Saltz, Joel

2015-01-01

We introduce a region template abstraction and framework for the efficient storage, management and processing of common data types in analysis of large datasets of high resolution images on clusters of hybrid computing nodes. The region template abstraction provides a generic container template for common data structures, such as points, arrays, regions, and object sets, within a spatial and temporal bounding box. It allows for different data management strategies and I/O implementations, while providing a homogeneous, unified interface to applications for data storage and retrieval. A region template application is represented as a hierarchical dataflow in which each computing stage may be represented as another dataflow of finer-grain tasks. The execution of the application is coordinated by a runtime system that implements optimizations for hybrid machines, including performance-aware scheduling for maximizing the utilization of computing devices and techniques to reduce the impact of data transfers between CPUs and GPUs. An experimental evaluation on a state-of-the-art hybrid cluster using a microscopy imaging application shows that the abstraction adds negligible overhead (about 3%) and achieves good scalability and high data transfer rates. Optimizations in a high speed disk based storage implementation of the abstraction to support asynchronous data transfers and computation result in an application performance gain of about 1.13×. Finally, a processing rate of 11,730 4K×4K tiles per minute was achieved for the microscopy imaging application on a cluster with 100 nodes (300 GPUs and 1,200 CPU cores). This computation rate enables studies with very large datasets. PMID:26139953

Funding community medicines by exception: a descriptive epidemiological study from New Zealand.

PubMed

Rasiah, Dilky; Edwards, Richard; Crampton, Peter

2012-02-24

To assess rates of approval and identify factors associated with successful applications for funding to the New Zealand Community Exceptional Circumstances (CEC) scheme. Descriptive quantitative analysis of data in CEC applications database. The main outcome was initial application approval rate. Analysis included calculation of unadjusted and adjusted associations between potential determinants (for example patient age, gender) and outcomes using logistic regression analysis. All CEC applications with a decision about approval or decline 1 October 2001 to 30 September 2008 were included. Application numbers were high, but had reduced since 2001. A small number of medicines (11) and indications comprised about a third of the applications to the scheme. While some common applications were clearly outside the remit of the scheme, many applications were for patients who fitted the scheme's eligibility criteria. The overall initial application approval rate was 16% and the renewal application approval rate was 88%. Approval rates varied widely by type of medicine, therapeutic group and indication. After adjusting for other potential determinants there were no statistically significant differences in initial approval rates by gender, ethnicity or socioeconomic status of the patient. There were however, significant differences in initial application approval by age of the patient, type of applicant doctor and by geographical location of the applicant doctor. There was no evidence that gender, ethnicity and socioeconomic status of patients were factors associated with successful applications. However, applications for younger patients, those made by specialists, and those made by applying clinicians from the Auckland District Health Board area were more likely to be successful. It is possible that this may to some degree be appropriate, but requires further research.

[Assessment of progesterone levels on the day of the hCG administration as a predictor of success of antagonist stimulation protocols for IVF].

PubMed

Kably-Ambe, Alberta; Roque-Sánchez, Armando Miguel; Soriano-Ortega, Karla Patricia; Carballo-Mondragón, Esperanza; Durán-Monterrosas, Leonor

2015-03-01

There are reports of deleterious effect when progesterone concentration is high during the follicular phase in cycles of in vitro fertilization. In our environment has not carried out a study to evaluate the pregnancy rate compared with progesterone concentration on the day of application of hCG. To evaluate the pregnancy rate and outcome of in vitro fertilization cycle according to serum progesterone concentration on the day of application of hCG. A retrospective, observational, cross-sectional study of 486 cycles of in vitro fertilization was done in the Centro Mexicano de Fertilidad of CEPAM (Hospital Angeles de las Lomas) from January 2009 to February 2014. We included all cases where it was used a stimulation protocol GnRH antagonist flexible scheme. When levels of progesterone are high, those of estradiol are also high and the number of retrieved oocytes and oocyte quality are lower. There was no difference in the percentage of fertilization, but at higher concentration of progesterone lower percentage of embryonic segmentation. Difference was recorded in the pregnancy rate only when progesterone concentration on the day of hCG application was > 4 ng/mL. Pregnancy rate decreases when the concentration of progesterone on the day of hCG application is ≥ 4 ng/mL.

Dynamic chemical characteristics of soil solution after pig manure application: a column study.

PubMed

Hao, Xiuzhen; Zhou, Dongmei; Sun, Lei; Li, Lianzhen; Zhang, Hailin

2008-06-01

When manures from intensive livestock operations are applied to agricultural or vegetable fields at a high rate, large amounts of salts and metals will be introduced into soils. Using a column leaching experiment, this study assessed the leaching potential of the downward movement of Cu and Zn as well as some salt ions after an intensive farm pig manure at rates of 0%, 5% and 10% (w/w) were applied to the top 20 cm of two different textured soils (G soil -sandy loam soil; H soil-silty clay loam soil), and investigated the growth of amaranth and Cu and Zn transfer from soil to amaranth (Amaranthus tricolor). Soil solutions were obtained at 20, 40 and 60 cm depth of the packed column and analyzed for pH, electrical conductivity (EC), dissolved organic matter (DOC) and Cu and Zn concentrations. The results indicated that application of pig manure containing Cu and Zn to sandy loam soil might cause higher leaching and uptake risk than silty clay loam soil, especially at high application rates. And manure amendment at 5% and 10% significantly decreased the biomass of amaranth, in which the salt impact rather than Cu and Zn toxicity from manures played more important role in amaranth growth. Thus the farmer should avoid application the high rate of pig manure containing metal and salt to soil at a time, especially in sandy soil.

Review of researches on smartphone applications for physical activity promotion in healthy adults

PubMed Central

Jee, Haemi

2017-01-01

Physical activity is known as a preventative method for preventing life-style-related diseases. Smartphone applications for health and fitness intervention have released with rapid increase of innovative technology. Reviews of recent publications on mobile application have been conducted to observe feasibility and applicability for physical activity intervention. Bibliographic searches of PubMed and ScienceDirect were conducted with key terms, ‘physical activity,’ ‘fitness,’ ‘smart-phone,’ and ‘health’ between the years 2014 and 2017 to obtain 5,087 publications. Out of 5,087 articles, five articles on sensor-based applications and five articles on user entry-based applications were obtained through the inclusion and exclusion processes. Accuracy of the physical activity assessments were reported to be high in comparison to the conventional assessment tools. The overall subject rating on the app motivational ratings were positive with high correlation between physical activity and treats and cues. The adherence rates to the apps significantly dropped prior to 3 months. Publications that elucidate feasibility and accuracy of smartphone applications that motivates physical activity seem limited with adequately conducted study designs. Large-scaled, control-compared, long-term randomized control trials should be conducted to elucidate the effects of the app interventions. PMID:28349027

Brittle materials at high-loading rates: an open area of research

NASA Astrophysics Data System (ADS)

Forquin, Pascal

2017-01-01

Brittle materials are extensively used in many civil and military applications involving high-strain-rate loadings such as: blasting or percussive drilling of rocks, ballistic impact against ceramic armour or transparent windshields, plastic explosives used to damage or destroy concrete structures, soft or hard impacts against concrete structures and so on. With all of these applications, brittle materials are subjected to intense loadings characterized by medium to extremely high strain rates (few tens to several tens of thousands per second) leading to extreme and/or specific damage modes such as multiple fragmentation, dynamic cracking, pore collapse, shearing, mode II fracturing and/or microplasticity mechanisms in the material. Additionally, brittle materials exhibit complex features such as a strong strain-rate sensitivity and confining pressure sensitivity that justify expending greater research efforts to understand these complex features. Currently, the most popular dynamic testing techniques used for this are based on the use of split Hopkinson pressure bar methodologies and/or plate-impact testing methods. However, these methods do have some critical limitations and drawbacks when used to investigate the behaviour of brittle materials at high loading rates. The present theme issue of Philosophical Transactions A provides an overview of the latest experimental methods and numerical tools that are currently being developed to investigate the behaviour of brittle materials at high loading rates. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

Brittle materials at high-loading rates: an open area of research.

PubMed

Forquin, Pascal

2017-01-28

Brittle materials are extensively used in many civil and military applications involving high-strain-rate loadings such as: blasting or percussive drilling of rocks, ballistic impact against ceramic armour or transparent windshields, plastic explosives used to damage or destroy concrete structures, soft or hard impacts against concrete structures and so on. With all of these applications, brittle materials are subjected to intense loadings characterized by medium to extremely high strain rates (few tens to several tens of thousands per second) leading to extreme and/or specific damage modes such as multiple fragmentation, dynamic cracking, pore collapse, shearing, mode II fracturing and/or microplasticity mechanisms in the material. Additionally, brittle materials exhibit complex features such as a strong strain-rate sensitivity and confining pressure sensitivity that justify expending greater research efforts to understand these complex features. Currently, the most popular dynamic testing techniques used for this are based on the use of split Hopkinson pressure bar methodologies and/or plate-impact testing methods. However, these methods do have some critical limitations and drawbacks when used to investigate the behaviour of brittle materials at high loading rates. The present theme issue of Philosophical Transactions A provides an overview of the latest experimental methods and numerical tools that are currently being developed to investigate the behaviour of brittle materials at high loading rates.This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'. © 2016 The Author(s).

High-efficient catalytic reduction of 4-nitrophenol based on reusable Ag nanoparticles/graphene-loading loofah sponge hybrid.

PubMed

Liu, Y Y; Zhao, Y H; Zhou, Y; Guo, X L; Chen, Z T; Zhang, W J; Zhang, Y; Chen, J; Wang, Z M; Sun, L T; Zhang, T

2018-08-03

Noble metal nanoparticles (NPs) such as Au and Ag have shown many applications in the field of catalysis, sensing etc. due to their excellent photoelectric properties. But agglomeration and a low recovery rate are big problems for their applications. In this research, a novel Ag NPs/graphene (reduced graphene oxide)-loading loofah sponge (Ag NPs/RGO-LS) was synthesized through a one-step reduction method. Where the RGO is used as a nano-support with the high specific surface area and the high conductivity to prevent the agglomeration of Ag NPs and provide a conductive layer. The natural, green, low-cost and high-yield LS is designed as a macro-support to reduce the loss of Ag NPs during recycling. The as-prepared Ag NPs/RGO-LS is stable, uniform, and exhibits high efficiency and reusability in the catalytic reduction of 4-nitrophenol (4-NP) with a high rate constant of 1.893 min -1 as well as an average conversion of 98% in 6 min during five cycles. The results have not only paved the way for the wide application of Ag NPs but also provide a new road for the application of other metal NPs.

Mobile Applications and 4G Wireless Networks: A Framework for Analysis

ERIC Educational Resources Information Center

Yang, Samuel C.

2012-01-01

Purpose: The use of mobile wireless data services continues to increase worldwide. New fourth-generation (4G) wireless networks can deliver data rates exceeding 2 Mbps. The purpose of this paper is to develop a framework of 4G mobile applications that utilize such high data rates and run on small form-factor devices. Design/methodology/approach:…

Effect of urea application rate and water content on nitrous oxide emission from a sandy loam soil - a laboratory study

USDA-ARS?s Scientific Manuscript database

Agriculture is a major contributor to global anthropogenic nitrous oxide (N2O, a potent greenhouse gas) emission. Data from a pomegranate orchard indicate that N2O emission is highly variable with nitrogen application rates and irrigation methods. The aim of this study was to investigate the effect ...

Anaerobic digestion of municipal solid waste: Utility of process residues as a soil amendment

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

Rivard, C.J.; Nagle, N.J.; Kay, B.D.

1995-12-31

Tuna processing wastes (sludges high in fat, oil, and grease [FOG]) and municipal solid waste (MSW) generated on Tutuila Island, American Samoa, represent an ongoing disposal challenge. The biological conversion of the organic fraction of these wastes to useful products, including methane and fertilizer-grade residue, through anaerobic high-solids digestion is currently in scale-up development. The suitability of the anaerobic digestion residues as a soil amendment was evaluated through extensive chemical analysis and greenhouse studies using corn as an indicator crop. Additionally, native Samoan soil was used to evaluate the specific application rates for the compost. Experiments established that anaerobic residuesmore » increase crop yields in direct proportion to increases in the application rate. Additionally, nutrient saturation was not demonstrated within the range of application rates evaluated for the Samoan soil. Beyond nutrient supplementation, organic residue amendment to Samoan soil imparts enhanced water and nutrient-binding capacities.« less

Long term fate of slurry derived nitrogen in soil: a case study with a macro-lysimeter experiment having received high loads of pig slurry (Solepur).

PubMed

Peu, P; Birgand, F; Martinez, J

2007-12-01

In intensive livestock production areas, land application remains the traditional management of manure and slurries for nutrient recycling. For sustainable agriculture there is fear, however, that this practice may have detrimental effects, particularly on the depletion of Soil Organic Matter associated with pig slurry applications. We investigated the long-term fate of nitrogen in a reconstituted soil having received high doses of pig slurry during 5 years (1991-1995). After 5 years of intensive application rates (nearly 1000 m(3)yr(-1)), the N and C content of the soil profile (0-20 cm) had increased by about 60% and 50%, respectively. These results confirm previous findings although it seems that the particularly high rates of application may explain, in part, the relatively important N incorporation in soil. Pig slurry applications ceased in 1995 and nitrogen content in soil and drainage water have been monitored. Apparent mineralization rates were calculated from the decrease in N content of the soil. This analysis indicated that more than 50% of the added N stored in the soil at the end of the applications would eventually be mineralized, leaving nearly 50% of the stored N to be immobilized in the soil. These results are the first published of their kinds, as most reports never examine the fate of applied pig slurry N after halting applications. In addition the few reports on long-term experiments suggest that Soil Organic Matter following pig slurry applications may be unstable. Our analysis tends to show the contrary. However, this conclusion must be tempered because data on nitrate leachate patterns suggest that soil management such as ploughing and sowing may actually trigger mineralization that could eventually deplete nitrogen stored following applications.

The European project Hippo high-power photonics for satellite laser communications and on-board optical processing

NASA Astrophysics Data System (ADS)

Kehayas, E.; Stampoulidis, L.; Henderson, P.; Robertson, Andrew; Van Dijk, F.; Achouche, M.; Le Kernec, A.; Sotom, M.; Schuberts, F.; Brabant, T.

2017-11-01

Photonics is progressively transforming from a highly- focused technology applicable to digital communication networks into a pervasive "enabling" technology with diverse non-telecom applications. However, the centre of mass on the R&D level is still mostly driven by, and invested in, by stakeholders active in the telecoms domain. This is due to the high level of investments necessary that in turn require a large and established market for reaching break-even and generation of revenues. Photonics technology and more specifically, fibre-optic technology is moving into non-telecom business areas with great success in terms of markets captured and penetration rates. One example that cannot be overlooked is the application of fibre-optics to industrial applications, where double-digit growth rates are recorded with fibre lasers and amplifiers constantly gaining momentum. In this example, several years of R&D efforts in creating high-power amplification solutions and fibre-laser sources by the telecom sector, were piggy-backed into industrial applications and laser cutting/welding equipment that is now a strong R&D sector on its own and commercially now displacing some conventional free space laser cutting/welding.

How effective are the ESC/EAS and 2013 ACC/AHA guidelines in treating dyslipidemia? Lessons from a lipid clinic.

PubMed

Barkas, Fotios; Milionis, Haralampos; Kostapanos, Michael S; Mikhailidis, Dimitri P; Elisaf, Moses; Liberopoulos, Evangelos

2015-02-01

There is a paucity of data regarding the attainment of lipid-lowering treatment goals according to the recent American College of Cardiology/American Heart Association (ACC/AHA) guidelines. The aim of the present study was to assess how applicable these 2013 recommendations are in the setting of an Outpatient University Hospital Lipid Clinic. This was a retrospective (from 1999 to 2013) observational study including 1000 consecutive adults treated for hyperlipidemia and followed up for ≥3 years. Comparisons for the applicability of current European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) and recent ACC/AHA guidelines were performed. Achievement rates of low density lipoprotein cholesterol (LDL-C) targets set by ESC/EAS were 21%, 44% and 62% among patients at very high, high and moderate cardiovascular risk, respectively, receiving statin monotherapy. Among individuals on high-intensity statins only 47% achieved the anticipated ≥50% LDL-C reduction, i.e. the ACC/AHA target. The corresponding rate was significantly greater among those on statin + ezetimibe (76%, p < 0.05). Likewise, higher rates of LDL-C target attainment according to ESC/EAS guidelines were observed in patients on statin + ezetimibe compared with statin monotherapy (37, 50 and 71% for the three risk groups, p < 0.05 for the very high risk group). The application of the ACC/AHA guidelines may be associated with undertreatment of high risk patients due to suboptimal LDL-C response to high-intensity statins in clinical practice. Adding ezetimibe substantially increases the rate of the ESC/EAS LDL-C target achievement together with the rate of LDL-C lowering response suggested by the ACC/AHA.

Acidifier application rate impacts on ammonia emissions from US roaster chicken houses

NASA Astrophysics Data System (ADS)

Shah, Sanjay B.; Grimes, Jesse L.; Oviedo-Rondón, Edgar O.; Westerman, Philip W.

2014-08-01

Due to its potential environmental and public health impacts, emissions of ammonia (NH3) as well as several other gases from US livestock farms may be regulated. Broiler houses are important sources of NH3 emissions. However, there are no emissions data from roaster (8-12 wk old broilers, ˜4 kg ea.) houses. Producers treat the litter in broiler houses with acidifiers, such as sodium bisulfate (SBS, NaHSO4) to reduce ammonia production and protect bird health. However, there is very little data on the effect of acidifiers, particularly at high application rates on ammonia emissions. The impact of different SBS application rates [High (0.95-1.46 kg m-2, whole house), Medium (0.73 kg m-2, whole house), Low (0.37-0.49 kg m-2, whole house), and Control (0.37-0.49 kg m-2, brood chamber)] on ammonia emissions was evaluated in commercial roaster houses over 22 months spanning eight flocks. Ammonia emission from each fan was measured with an acid scrubber that operated only when the fan operated. Emissions were calculated using >95% measured data with the rest being estimated using robust methods. Exhaust ammonia-N concentrations were inversely correlated with the SBS application rates. Emission rates on animal unit (AU, where 1 AU = 500 kg live-mass) basis (ER, g d-1 AU-1) were reduced by 27, 13, and 5%, respectively, in the High, Medium, and Low treatments vs. the Control treatment (mean: 100 g d-1 AU-1, range: 86-114 g d-1 AU-1). Emission rates for the Control treatment measured in this study on roasters were mostly higher than ERs in the literature. Differences in ERs are not only due to diet, environmental and management conditions, but also due to measurement methods.

Effectiveness of distinct mulch application rates and schemes under laboratory conditions

NASA Astrophysics Data System (ADS)

Prats, Sergio; Abrantes, Joao; Crema, Isabela; Keizer, Jacob; de Lima, Joao

2017-04-01

Post-fire forest residue mulching using eucalypt bark strands have been proven effective for reducing hillslope runoff and erosion in field plots of different sizes. Application rates of around 8-10 Mg ha-1 achieved about 80% of protective soil surface. Lower application rates, however, would reduce costs and, possibly, also allow faster application, which could be especially critical in late summer high-severity fires. Such lower rates could be achieved by applying less mulch per unit area, by applying mulch in specific zones (strips) and by removing the finest fractions, especially since these can be expected to contribute little to reduce erosion risk. The objective of this laboratory study was to identify the threshold, or the minimum application rate, at which a new mulch blend (without the fraction ≤4 cm) would effectively control runoff and erosion. Two levels of ground cover by forest residue mulch (50 and 70%) and three mulch strips (of 1/3, 2/3 and 3/3) at the bottom of the flume were tested against the untreated bare soil, by applying simulated rainfall and simulated inflow. The seven treatments were replicated three times using a 2.7 m x 0.3 m soil flume with a 40% slope, filled with a dry loamy sand soil. Each experiment included: (i) a "Dry" soil run comprising 20 min of simulated rainfall at a rate of 56 mm h-1; (ii) a "Wet" soil run with the same rainfall characteristics; (iii) a "Flow" run combining 20 min of rainfall with three inflows at increasing rates (52, 110, 232 mm h-1) on nearly saturated soil. The results showed that runoff, interrill and rill erosion were strongly reduced by covering 3/3 and 2/3 of the flume with mulch at 70% ground cover (overall mulch application rates of 2.6 and 1.3 Mg ha-1). The 1/3 mulch strip at 70% mulch cover (application rate of 1 Mg ha-1) also reduced significantly erosion but not runoff. The mulch strips at 50% were less effective, and only the application over the whole plot was able to reduce interrill and rill erosion. Apparently, runoff depended most on mulch cover, while soil losses depended most on strip width. Even so, the new mulch was poorly effective in reducing runoff but effective in reducing interrill erosion and even highly effective in reducing rill erosion.

[THE COMPARATIVE ANALYSIS OF RESULTS OF DETECTION OF CARCINOGENIC TYPES OF HUMAN PAPILLOMA VIRUS BY QUALITATIVE AND QUANTITATIVE TESTS].

PubMed

Kuzmenko, E T; Labigina, A V; Leshenko, O Ya; Rusanov, D N; Kuzmenko, V V; Fedko, L P; Pak, I P

2015-05-01

The analysis of results of screening (n = 3208; sexually active citizen aged from 18 to 59 years) was carried out to detect oncogene types of human papilloma virus in using qualitative (1150 females and 720 males) and quantitative (polymerase chain reaction in real-time (843 females and 115 males) techniques. The human papilloma virus of high oncogene type was detected in 65% and 68.4% of females and in 48.6% and 53% of males correspondingly. Among 12 types of human papilloma virus the most frequently diagnosed was human papilloma virus 16 independently of gender of examined and technique of analysis. In females, under application of qualitative tests rate of human papilloma virus 16 made up to 18.3% (n = 280) and under application of quantitative tests Rte of human papilloma virus made up to 14.9% (n = 126; p ≤ 0.05). Under examination of males using qualitative tests rate of human papilloma virus 16 made up to 8.3% (n = 60) and under application of qualitative tests made up to 12.2% (n = 14; p ≥ 0.05). Under application of qualitative tests rate of detection on the rest ofoncogene types of human papilloma virus varied in females from 3.4% to 8.4% and in males from 1.8% to 5.9%. Under application of qualitative tests to females rate of human papilloma virus with high viral load made up to 68.4%, with medium viral load - 2.85% (n = 24) and with low viral load -0.24% (n = 2). Under application of quantitative tests in males rate of detection of types of human papilloma virus made up to 53% and at that in all high viral load was established. In females, the most of oncogene types of human papilloma virus (except for 31, 39, 59) are detected significantly more often than in males.

The effects of applicant's health status and qualifications on simulated hiring decisions.

PubMed

Klesges, R C; Klem, M L; Hanson, C L; Eck, L H; Ernst, J; O'Laughlin, D; Garrott, A; Rife, R

1990-06-01

The effects of having diabetes or obesity on simulated job decisions was evaluated in a two (qualifications, high v. marginal) by three (diabetes, mildly obese, or normal) design. Subjects were 295 adults, averaging 5.02 years of full-time employment in white-collar settings, recruited in advanced level graduate or undergraduate business classes. Each subject examined a job description and a resume of the 'applicant' and viewed a 5-minute videotape. The applicant's face was never seen and an off-camera voice, constant across all conditions, was dubbed in for the applicant's responses to the interviewer's questions. Subjects were then asked to rate the applicant's qualification level and demeanor during the interview and to recommend whether or not to hire the individual. Subjects were also asked to make ratings about the applicant's work habits, work reliability and absenteeism, and interpersonal skills (e.g. emotional problems, likeability). Results indicated that level of quantification affected decisions to hire the applicant in the predicted direction. However, the obese applicant was rated as less qualified for the job, and both the diabetic and obese applicant were less likely to be hired, although they were rated similarly on personal appearance, attitude during the interview, and communication skills. Additionally, both the obese and the diabetic applicant were viewed as having poorer work habits. The diabetic was rated as much more likely to have medically-related job absences, whereas the obese applicant was rated as more likely to have other absences (e.g. abusing company privileges by feigning illness) and to have emotional and interpersonal problems.(ABSTRACT TRUNCATED AT 250 WORDS)

Exploring the Impact of Applicants' Gender and Religion on Principals' Screening Decisions for Assistant Principal Applicants

ERIC Educational Resources Information Center

Bon, Susan C.

2009-01-01

In this experimental study, a national random sample of high school principals (stratified by gender) were asked to evaluate hypothetical applicants whose resumes varied by religion (Jewish, Catholic, nondenominational) and gender (male, female) for employment as assistant principals. Results reveal that male principals rate all applicants higher…

Evaluation of a commercial Bacillus thuringiensis var. israelensis formulation for the control of chironomid midge larvae (Diptera: Chironomidae) in establishing rice crops in south-eastern Australia.

PubMed

Stevens, Mark M; Hughes, Peter A; Mo, Jianhua

2013-01-01

A commercial formulation of Bacillus thuringiensis var. israelensis (B.t.i.) was evaluated for its potential to control chironomid midge larvae in newly sown rice crops in south-eastern Australia. Two replicated small-plot field trials were conducted using product application rates of 0.5-6 kg/ha. In trial 1 application rates between 2 and 6 kg product/ha all significantly (P<0.05) reduced populations of target Chironominae/Orthocladiinae by between 71% and 93% over the 19 day post-treatment monitoring period. Trial 2 was conducted using lower application rates (0.5-2 kg product/ha) and only the 2 kg product/ha rate significantly (P<0.05) reduced numbers of the target group (81% reduction) despite lower application rates resulting in target group suppression of 38-62%. Identification of larvae to species level from selected samples indicated that populations of Chironomus tepperi, the principal pest species that attacks the roots of rice seedlings, were reduced at all application rates; elimination of C. tepperi was achieved in trial 1 at an application rate of 2 kg/ha. Consistent with other studies, non-target Tanypodinae were not adversely affected by B.t.i., and in some treatments populations of Tanypodinae exceeded control levels by up to 73%. In the first trial, which was conducted under relatively high pest pressure, plant establishment was significantly (P<0.05) increased (120-157%) by Vectobac® WDG application rates of 2-6 kg/ha. No significant increase in plant establishment relative to the controls was identified in the second trial, when pest pressure was substantially lower and minimal damage occurred in the control bays. Overall, our results demonstrate that B.t.i. may be an economically viable alternative to broad-spectrum synthetic pesticides for the control of phytophagous midge larvae in establishing rice crops where members of the Chironominae, the group most susceptible to B.t.i., are the principal species of concern. The high specificity of B.t.i. for nematoceran Diptera should lead to reduced impacts on non-target organisms. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of Application Propolis as Biocoating on the Physical and Chemical Properties of Tomatoes Stored at Room Temperature

NASA Astrophysics Data System (ADS)

E Putra, R.; Khairannisa, S.; Kinasih, I.

2017-03-01

Tomatoes is considered as one of important horticulture commodities which highly consume by Indonesia consumer. However, this horticulture product is perishable with high rate which reduce quantity and quality of marketable products. One of the method could be used to prevent this problem by application of edible biocoating. In this study, various concentration of ethanolic propolis extract was applied to tomatoes in order to find the effect of propolis coating in tomato preservation and best concentration for application. Tomatoes were grouped into 5 group, namely control group (no coating application), ethanol group (tomato wash with ethanol), and application group (coated with 5%, 10%, and 15% propolis). Variables observed during study were weight change, fruit firmness, total soluble solute, vitamin C, and lycopene. All tomatoes were kept in room temperature for 14 days and observation conducted every 2 days. Result showed that application of 10% propolis as biocoating reduced rate of weight loss and maintained fruit firmness while other variables relatively unaffected by propolis coating.

High strain rate behaviour of polypropylene microfoams

NASA Astrophysics Data System (ADS)

Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

2012-08-01

Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

The Pulsed Cylindrical Magnetron for Deposition

NASA Astrophysics Data System (ADS)

Korenev, Sergey

2012-10-01

The magnetron sputtering deposition of films and coatings broadly uses in microelectronics, material science, environmental applications and etc. The rate of target evaporation and time for deposition of films and coatings depends on magnetic field. These parameters link with efficiency of gas molecules ionization by electrons. The cylindrical magnetrons use for deposition of films and coatings on inside of pipes for different protective films and coatings in oil, chemical, environmental applications. The classical forming of magnetic field by permanent magnets or coils for big and long cylindrical magnetrons is complicated. The new concept of pulsed cylindrical magnetron for high rate deposition of films and coating for big and long pipes is presented in this paper. The proposed cylindrical magnetron has azimuthally pulsed high magnetic field, which allows forming the high ionized plasma and receiving high rate of evaporation material of target (central electrode). The structure of proposed pulsed cylindrical magnetron sputtering system is given. The main requirements to deposition system are presented. The preliminary data for forming of plasma and deposition of Ta films and coatings on the metal pipers are discussed. The comparison of classical and proposed cylindrical magnetrons is given. The analysis of potential applications is considered.

Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

NASA Technical Reports Server (NTRS)

1975-01-01

Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

Employment Barriers Among Welfare Recipients and Applicants With Chronically Ill Children

PubMed Central

Smith, Lauren A.; Romero, Diana; Wood, Pamela R.; Wampler, Nina S.; Chavkin, Wendy; Wise, Paul H.

2002-01-01

Objectives. This study evaluated the association of chronic child illness with parental employment among individuals who have had contact with the welfare system. Methods. Parents of children with chronic illnesses were interviewed. Results. Current and former welfare recipients and welfare applicants were more likely than those with no contact with the welfare system to report that their children’s illnesses adversely affected their employment. Logistic regression analyses showed that current and former receipt of welfare, pending welfare application, and high rates of child health care use were predictors of unemployment. Conclusions. Welfare recipients and applicants with chronically ill children face substantial barriers to employment, including high child health care use rates and missed work. The welfare reform reauthorization scheduled to occur later in 2002 should address the implications of chronic child illness for parental employment. PMID:12197972

Effects of pumping strategies on pesticide concentration of a drinking water well

NASA Astrophysics Data System (ADS)

Aisopou, A.; Bjerg, P. L.; Binning, P. J.; Albrechtsen, H.

2011-12-01

Groundwater is an important source of drinking water production in many countries including Denmark. This requires high quality groundwater that meets the standards of the European Water Framework Directive. Yet as a result of agricultural activitity, deposition and previous handling, pesticides are frequently found in groundwater and can raise a substantial problem for ground water abstraction. The concentration of this contamination may vary between different layers. The heterogeneity of the subsurface geology and the depth of the drinking water well's screen are important parameters that affect the resulting contamination of the abstracted groundwater. The pesticide concentration in wells may also be affected by the pumping strategy because pumping can alter the structure of the flow field, the flowpath of water going to the well and subsequently the age of water at the well. The purpose of this study was to examine numerically the effects of pumping on pesticide contamination of drinking water wells using a reactive transport model in a hypothetical aquifer system resembling a typical Danish well field. The application history of the pesticides is crucial. This can be taken into account by assessing the effects of pumping on water age distribution along the well. Three compounds with different application histories were considered: an old banned pesticide MCPP (Mecoprop) which is mobile and relatively persistent in deeper aquifers, and a highly applied, biodegradable and strongly sorbing pesticide glyphosate, and its degradation product AMPA. A steady state flow field was first computed. A well field was then introduced and different pumping regimes were applied for a period of 180 years; a low-rate pumping, a high-rate pumping and a varying pumping regime. A constant application rate at the surface was assumed for the application period of each pesticide. The pre-abstraction age distribution of the water in the system was first estimated using a steady-state flow and transport simulation. These water ages were then used as the initial conditions for the transient simulations. The results of the simulations showed that the range of water ages contributing to the well increased during pumping and was substantially affected by the pumping rate. High pesticide concentrations were persistent in the well 40 to 100 years after they were banned, due to the high residence times in the aquifer. Large changes in simulated pesticides concentrations at the well occurred during pumping. The pesticide concentration reaching the well was affected by the pumping regime and the pesticide application history and properties. A higher pumping rate induced a higher pesticide concentration peak at the well of shorter duration, while a lower pumping rate induced a lower concentration peak of longer duration. The long term scenarios revealed that at high pumping rates MCPP would disappear 40 years after its application end year, while glyphosate concentrations increase and reach a plateau, which is highly dependent on the pumping rate. The findings of the study help understand the results of groundwater monitoring programmes and can be used for the quantitative evaluation of management and pumping strategies for the long-term supply of safe potable groundwater.

Design and characteristics of MRF-based actuators for torque transmission under influence of high shear rates up to 34,000s-1

NASA Astrophysics Data System (ADS)

Güth, Dirk; Erbis, Vadim; Schamoni, Markus; Maas, Jürgen

2014-04-01

High rotational speeds for brakes and clutches based on magnetorheological fluids represent a remaining challenge for the industrial or automotive application. Beside particle centrifugation effects and rotational speed-depending no-load losses, the torque characteristic is an important property that needs to considered in the design process of actuators. Due to missing experimental data for these operating conditions, in this paper the shear rate and flux depending yield stress behavior of magnetorheological uids is experimentally investigated for high rotational speeds or respectively high shear rates. Therefore a brake actuator with variable shear gap heights up to 4 mm is designed, realized and used for the experimental investigation, which are performed for a maximum shear rate of ƴ= 34; 000 s-1 under large magnetic elds. The measurement results point out a strong dependency between shear rate, magnetic ux density and resulting yield stress. For low shear gap heights, a significant reduction in the yield stress up to 10 % can be determined. Additionally the development of Taylor vortices is determined, which will not only occur in viscous case without an applied magnetic field. The measurement results are important for a reliable actuator design which should be used in application with high rotational speeds.

Application of Low Melting Point Thermoplastics to Hybrid Rocket Fuel

NASA Astrophysics Data System (ADS)

Wada, Yutaka; Jikei, Mitsutoshi; Kato, Ryuichi; Kato, Nobuji; Hori, Keiichi

This paper introduces the application of low melting point thermoplastics (LT) to hybrid rocket fuel. LT made by Katazen Corporation has an excellent mechanical property comparing with other thermoplastics and prospect of high surface regression rate because it has a similar physical property with low melting point of paraffin fuel which has high regression rate probably due to the entrainment mass transfer mechanism that droplets continuously depart out of the surface melt layer. Several different types of LT developed by Katazen Corporation for this use have been evaluated in the measurements of regression rate, mechanical properties These results show the LTs have the higher regression rate and better mechanical properties comparing with conventional hybrid rocket fuels. Observation was also made using a small 2D combustor, and the entrainment mass transfer mechanism is confirmed with the LT fuels.

Analysis of Wear Behavior of Graphene OXIDE — Polyamide Gears for Engineering Applications

NASA Astrophysics Data System (ADS)

Rajamani, Geetha; Paulraj, Jawahar; Krishnan, Kanny

Recent advances in polymer nanocomposites open a wide range of applications in various industrial sectors. Due to their high potential properties, these materials are replacing the usage of metals for many heavier components in automobile industries. In this experimental work, the tribological performance of Graphene oxide (GO) — Polyamide is investigated against pristine polyamide by fabricating gears for the usage in engineering applications. A gear test rig was developed in-house for analysis to study the specific wear rate and temperature gradient at different conditions of load and speeds. The wear resistance of the polyamide gears with the addition of 0.03wt.% of graphene oxide is better than the pristine polyamide gears and the specific wear rate is reduced significantly. The reduced specific wear rate of these polymer nanocomposite gears is attributed to the superior properties of graphene oxide such as High specific surface area, good adhesion properties and enhanced glass transition temperatures. The GO nanocomposite gear seems to be a potential alternative against conventional gears for engineering applications. Finally, the wear mechanisms and the potential of GO-based polyamide nanocomposite gears were proposed tentatively in the development of transmission gears for engineering applications.

Generation of µW level plateau harmonics at high repetition rate.

PubMed

Hädrich, S; Krebs, M; Rothhardt, J; Carstens, H; Demmler, S; Limpert, J; Tünnermann, A

2011-09-26

The process of high harmonic generation allows for coherent transfer of infrared laser light to the extreme ultraviolet spectral range opening a variety of applications. The low conversion efficiency of this process calls for optimization or higher repetition rate intense ultrashort pulse lasers. Here we present state-of-the-art fiber laser systems for the generation of high harmonics up to 1 MHz repetition rate. We perform measurements of the average power with a calibrated spectrometer and achieved µW harmonics between 45 nm and 61 nm (H23-H17) at a repetition rate of 50 kHz. Additionally, we show the potential for few-cycle pulses at high average power and repetition rate that may enable water-window harmonics at unprecedented repetition rate. © 2011 Optical Society of America

Compact fiber optic gyroscopes for platform stabilization

NASA Astrophysics Data System (ADS)

Dickson, William C.; Yee, Ting K.; Coward, James F.; McClaren, Andrew; Pechner, David A.

2013-09-01

SA Photonics has developed a family of compact Fiber Optic Gyroscopes (FOGs) for platform stabilization applications. The use of short fiber coils enables the high update rates required for stabilization applications but presents challenges to maintain high performance. We are able to match the performance of much larger FOGs by utilizing several innovative technologies. These technologies include source noise reduction to minimize Angular Random Walk (ARW), advanced digital signal processing that minimizes bias drift at high update rates, and advanced passive thermal packaging that minimizes temperature induced bias drift while not significantly affecting size, weight, or power. In addition, SA Photonics has developed unique distributed FOG packaging technologies allowing the FOG electronics and photonics to be packaged remotely from the sensor head or independent axis heads to minimize size, weight, and power at the sensing location(s). The use of these technologies has resulted in high performance, including ARW less than 0.001 deg/rt-hr and bias drift less than 0.004 deg/hr at an update rate of 10 kHz, and total packaged volume less than 30 cu. in. for a 6 degree of freedom FOG-based IMU. Specific applications include optical beam stabilization for LIDAR and LADAR, beam stabilization for long-range free-space optical communication, Optical Inertial Reference Units for HEL stabilization, and Ka band antenna pedestal pointing and stabilization. The high performance of our FOGs also enables their use in traditional navigation and positioning applications. This paper will review the technologies enabling our high-performance compact FOGs, and will provide performance test results.

The HALNA project: Diode-pumped solid-state laser for inertial fusion energy

NASA Astrophysics Data System (ADS)

Kawashima, T.; Ikegawa, T.; Kawanaka, J.; Miyanaga, N.; Nakatsuka, M.; Izawa, Y.; Matsumoto, O.; Yasuhara, R.; Kurita, T.; Sekine, T.; Miyamoto, M.; Kan, H.; Furukawa, H.; Motokoshi, S.; Kanabe, T.

2006-06-01

High-enery, rep.-rated, diode-pumped solid-state laser (DPSSL) is one of leading candidates for inertial fusion energy driver (IFE) and related laser-driven high-field applications. The project for the development of IFE laser driver in Japan, HALNA (High Average-power Laser for Nuclear Fusion Application) at ILE, Osaka University, aims to demonstrate 100-J pulse energy at 10 Hz rep. rate with 5 times diffraction limited beam quality. In this article, the advanced solid-state laser technologies for one half scale of HALNA (50 J, 10 Hz) are presented including thermally managed slab amplifier of Nd:phosphate glass and zig-zag optical geometry, and uniform, large-area diode-pumping.

Brittle materials at high-loading rates: an open area of research

PubMed Central

2017-01-01

Brittle materials are extensively used in many civil and military applications involving high-strain-rate loadings such as: blasting or percussive drilling of rocks, ballistic impact against ceramic armour or transparent windshields, plastic explosives used to damage or destroy concrete structures, soft or hard impacts against concrete structures and so on. With all of these applications, brittle materials are subjected to intense loadings characterized by medium to extremely high strain rates (few tens to several tens of thousands per second) leading to extreme and/or specific damage modes such as multiple fragmentation, dynamic cracking, pore collapse, shearing, mode II fracturing and/or microplasticity mechanisms in the material. Additionally, brittle materials exhibit complex features such as a strong strain-rate sensitivity and confining pressure sensitivity that justify expending greater research efforts to understand these complex features. Currently, the most popular dynamic testing techniques used for this are based on the use of split Hopkinson pressure bar methodologies and/or plate-impact testing methods. However, these methods do have some critical limitations and drawbacks when used to investigate the behaviour of brittle materials at high loading rates. The present theme issue of Philosophical Transactions A provides an overview of the latest experimental methods and numerical tools that are currently being developed to investigate the behaviour of brittle materials at high loading rates. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’. PMID:27956517

A Review of Australian and New Zealand Investigations on Aeronautical Fatigue During the Period April 2003 to March 2005

DTIC Science & Technology

2005-05-01

through the Application of Loading (FINAL) (B. Dixon, S. Barter and L. Molent, DSTO...possible that of an aircraft in flight. This required a high degree of load fidelity and a high rate of test load application . This was accomplished by...Identification through the Application of Loading (FINAL) (B. Dixon, S. Barter and L. Molent, DSTO) The teardown and inspection of aircraft, which have

A practical large scale/high speed data distribution system using 8 mm libraries

NASA Technical Reports Server (NTRS)

Howard, Kevin

1993-01-01

Eight mm tape libraries are known primarily for their small size, large storage capacity, and low cost. However, many applications require an additional attribute which, heretofore, has been lacking -- high transfer rate. Transfer rate is particularly important in a large scale data distribution environment -- an environment in which 8 mm tape should play a very important role. Data distribution is a natural application for 8 mm for several reasons: most large laboratories have access to 8 mm tape drives, 8 mm tapes are upwardly compatible, 8 mm media are very inexpensive, 8 mm media are light weight (important for shipping purposes), and 8 mm media densely pack data (5 gigabytes now and 15 gigabytes on the horizon). If the transfer rate issue were resolved, 8 mm could offer a good solution to the data distribution problem. To that end Exabyte has analyzed four ways to increase its transfer rate: native drive transfer rate increases, data compression at the drive level, tape striping, and homogeneous drive utilization. Exabyte is actively pursuing native drive transfer rate increases and drive level data compression. However, for non-transmitted bulk data applications (which include data distribution) the other two methods (tape striping and homogeneous drive utilization) hold promise.

High-frequency imaging radar for robotic navigation and situational awareness

NASA Astrophysics Data System (ADS)

Thomas, David J.; Luo, Changan; Knox, Robert

2011-05-01

With increasingly available high frequency radar components, the practicality of imaging radar for mobile robotic applications is now practical. Navigation, ODOA, situational awareness and safety applications can be supported in small light weight packaging. Radar has the additional advantage of being able sense through aerosols, smoke and dust that can be difficult for many optical systems. The ability to directly measure the range rate of an object is also an advantage in radar applications. This paper will explore the applicability of high frequency imaging radar for mobile robotics and examine a W-band 360 degree imaging radar prototype. Indoor and outdoor performance data will be analyzed and evaluated for applicability to navigation and situational awareness.

Application of low-power, high-rate PCM telemetry in a helicopter instrumentation system

NASA Technical Reports Server (NTRS)

Thomas, Mitchel E.; Diamond, John K.

1987-01-01

The use of low-power, high-rate pulse code modulation (PCM) in a helicopter instrumentation system is examined. A Helicopter Instrumentation and Recording System (HIARS) was developed to obtain main rotor blade measurements and fuselage performance measurements. The HIARS consists of a low-power PCM telemeter, a digital PCM system, an optical rotor position sensor, and a PCM decommutation unit; the components and functions of these subsystems are described. Flight tests were conducted to evaluate the ability of the HIARS to measure aircraft parameters. The test data reveal that the PCM telemetry is applicable to helicopter instrumentation systems.

FBCOT: a fast block coding option for JPEG 2000

NASA Astrophysics Data System (ADS)

Taubman, David; Naman, Aous; Mathew, Reji

2017-09-01

Based on the EBCOT algorithm, JPEG 2000 finds application in many fields, including high performance scientific, geospatial and video coding applications. Beyond digital cinema, JPEG 2000 is also attractive for low-latency video communications. The main obstacle for some of these applications is the relatively high computational complexity of the block coder, especially at high bit-rates. This paper proposes a drop-in replacement for the JPEG 2000 block coding algorithm, achieving much higher encoding and decoding throughputs, with only modest loss in coding efficiency (typically < 0.5dB). The algorithm provides only limited quality/SNR scalability, but offers truly reversible transcoding to/from any standard JPEG 2000 block bit-stream. The proposed FAST block coder can be used with EBCOT's post-compression RD-optimization methodology, allowing a target compressed bit-rate to be achieved even at low latencies, leading to the name FBCOT (Fast Block Coding with Optimized Truncation).

Mechanical Behavior of Glidcop Al-15 at High Temperature and Strain Rate

NASA Astrophysics Data System (ADS)

Scapin, M.; Peroni, L.; Fichera, C.

2014-05-01

Strain rate and temperature are variables of fundamental importance for the definition of the mechanical behavior of materials. In some elastic-plastic models, the effects, coming from these two quantities, are considered to act independently. This approach should, in some cases, allow to greatly simplify the experimental phase correlated to the parameter identification of the material model. Nevertheless, in several applications, the material is subjected to dynamic load at very high temperature, as, for example, in case of machining operation or high energy deposition on metals. In these cases, to consider the effect of strain rate and temperature decoupled could not be acceptable. In this perspective, in this work, a methodology for testing materials varying both strain rate and temperature was described and applied for the mechanical characterization of Glidcop Al-15, a copper-based composite reinforced with alumina dispersion, often used in nuclear applications. The tests at high strain rate were performed using the Hopkinson Bar setup for the direct tensile tests. The heating of the specimen was performed using an induction coil system and the temperature was controlled on the basis of signals from thermocouples directly welded on the specimen surface. Varying the strain rate, Glidcop Al-15 shows a moderate strain-rate sensitivity at room temperature, while it considerably increases at high temperature: material thermal softening and strain-rate hardening are strongly coupled. The experimental data were fitted using a modified formulation of the Zerilli-Armstrong model able to reproduce this kind of behavior with a good level of accuracy.

Evaluating variable rate fungicide applications for control of Sclerotinia

USDA-ARS?s Scientific Manuscript database

Oklahoma peanut growers continue to try to increase yields and reduce input costs. Perhaps the largest input in a peanut crop is fungicide applications. This is especially true for areas in the state that have high disease pressure from Sclerotinia. On average, a single fungicide application cost...

Minimax Rate-optimal Estimation of High-dimensional Covariance Matrices with Incomplete Data*

PubMed Central

Cai, T. Tony; Zhang, Anru

2016-01-01

Missing data occur frequently in a wide range of applications. In this paper, we consider estimation of high-dimensional covariance matrices in the presence of missing observations under a general missing completely at random model in the sense that the missingness is not dependent on the values of the data. Based on incomplete data, estimators for bandable and sparse covariance matrices are proposed and their theoretical and numerical properties are investigated. Minimax rates of convergence are established under the spectral norm loss and the proposed estimators are shown to be rate-optimal under mild regularity conditions. Simulation studies demonstrate that the estimators perform well numerically. The methods are also illustrated through an application to data from four ovarian cancer studies. The key technical tools developed in this paper are of independent interest and potentially useful for a range of related problems in high-dimensional statistical inference with missing data. PMID:27777471

Minimax Rate-optimal Estimation of High-dimensional Covariance Matrices with Incomplete Data.

PubMed

Cai, T Tony; Zhang, Anru

2016-09-01

Missing data occur frequently in a wide range of applications. In this paper, we consider estimation of high-dimensional covariance matrices in the presence of missing observations under a general missing completely at random model in the sense that the missingness is not dependent on the values of the data. Based on incomplete data, estimators for bandable and sparse covariance matrices are proposed and their theoretical and numerical properties are investigated. Minimax rates of convergence are established under the spectral norm loss and the proposed estimators are shown to be rate-optimal under mild regularity conditions. Simulation studies demonstrate that the estimators perform well numerically. The methods are also illustrated through an application to data from four ovarian cancer studies. The key technical tools developed in this paper are of independent interest and potentially useful for a range of related problems in high-dimensional statistical inference with missing data.

Challenges of Future High-End Computing

NASA Technical Reports Server (NTRS)

Bailey, David; Kutler, Paul (Technical Monitor)

1998-01-01

The next major milestone in high performance computing is a sustained rate of one Pflop/s (also written one petaflops, or 10(circumflex)15 floating-point operations per second). In addition to prodigiously high computational performance, such systems must of necessity feature very large main memories, as well as comparably high I/O bandwidth and huge mass storage facilities. The current consensus of scientists who have studied these issues is that "affordable" petaflops systems may be feasible by the year 2010, assuming that certain key technologies continue to progress at current rates. One important question is whether applications can be structured to perform efficiently on such systems, which are expected to incorporate many thousands of processors and deeply hierarchical memory systems. To answer these questions, advanced performance modeling techniques, including simulation of future architectures and applications, may be required. It may also be necessary to formulate "latency tolerant algorithms" and other completely new algorithmic approaches for certain applications. This talk will give an overview of these challenges.

Dynamic High-temperature Testing of an Iridium Alloy in Compression at High-strain Rates: Dynamic High-temperature Testing

DOE PAGES

Song, B.; Nelson, K.; Lipinski, R.; ...

2014-08-21

Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-strain -rate performance are needed for understanding high-speed impacts in severe environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain -rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. In our study, we analyzed the difficulties encountered in high-temperature Kolsky bar testing of thin iridium alloy specimens in compression. We made appropriate modifications using themore » current high-temperature Kolsky bar technique in order to obtain reliable compressive stress–strain response of an iridium alloy at high-strain rates (300–10 000 s -1) and temperatures (750 and 1030°C). The compressive stress–strain response of the iridium alloy showed significant sensitivity to both strain rate and temperature.« less

Network issues for large mass storage requirements

NASA Technical Reports Server (NTRS)

Perdue, James

1992-01-01

File Servers and Supercomputing environments need high performance networks to balance the I/O requirements seen in today's demanding computing scenarios. UltraNet is one solution which permits both high aggregate transfer rates and high task-to-task transfer rates as demonstrated in actual tests. UltraNet provides this capability as both a Server-to-Server and Server-to-Client access network giving the supercomputing center the following advantages highest performance Transport Level connections (to 40 MBytes/sec effective rates); matches the throughput of the emerging high performance disk technologies, such as RAID, parallel head transfer devices and software striping; supports standard network and file system applications using SOCKET's based application program interface such as FTP, rcp, rdump, etc.; supports access to the Network File System (NFS) and LARGE aggregate bandwidth for large NFS usage; provides access to a distributed, hierarchical data server capability using DISCOS UniTree product; supports file server solutions available from multiple vendors, including Cray, Convex, Alliant, FPS, IBM, and others.

Environmental and High-Strain Rate effects on composites for engine applications

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Smith, G. T.

1982-01-01

The Lewis Research Center is conducting a series of programs intended to investigate and develop the application of composite materials to structural components for turbojet engines. A significant part of that effort is directed to establishing resistance, defect growth, and strain rate characteristics of composite materials over the wide range of environmental and load conditions found in commercial turbojet engine operations. Both analytical and experimental efforts are involved.

Plant Growth-promoting Rhizobacteria Allow Reduced Application Rates of Chemical Fertilizers

USDA-ARS?s Scientific Manuscript database

Efforts to reduce fertilizer rates while increasing nutrient uptake to maintain high yields are very important due to the increasing cost of fertilizers and their potential negative environmental impacts. The objectives of this study were to determine (i) if reduced rates of inorganic fertilizer cou...

Evaluation of components, subsystems, and networks for high rate, high frequency space communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Ivancic, William D.; Zuzek, John E.

1991-01-01

The development of new space communications technologies by NASA has included both commercial applications and space science requirements. NASA's Systems Integration, Test and Evaluation (SITE) Space Communication System Simulator is a hardware based laboratory simulator for evaluating space communications technologies at the component, subsystem, system, and network level, geared toward high frequency, high data rate systems. The SITE facility is well-suited for evaluation of the new technologies required for the Space Exploration Initiative (SEI) and advanced commercial systems. Described here are the technology developments and evaluation requirements for current and planned commercial and space science programs. Also examined are the capabilities of SITE, the past, present and planned future configurations of the SITE facility, and applications of SITE to evaluation of SEI technology.

Atomized scan strategy for high definition for VR application

NASA Astrophysics Data System (ADS)

Huang, Shuping; Ran, Feng; Ji, Yuan; Chen, Wendong

2017-10-01

Silicon-based OLED (Organic Light Emitting Display) microdisplay technology begins to attract people's attention in the emerging VR and AR devices. The high display frame refresh rate is an important solution to alleviate the dizziness in VR applications. Traditional display circuit drivers use the analog method or the digital PWM method that follow the serial scan order from the first pixel to the last pixel by using the shift registers. This paper proposes a novel atomized scan strategy based on the digital fractal scan strategy using the pseudo-random scan order. It can be used to realize the high frame refresh rate with the moderate pixel clock frequency in the high definition OLED microdisplay. The linearity of the gray level is also improved compared with the Z fractal scan strategy.

High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

NASA Astrophysics Data System (ADS)

Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

2013-04-01

High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

Rate-compatible punctured convolutional codes (RCPC codes) and their applications

NASA Astrophysics Data System (ADS)

Hagenauer, Joachim

1988-04-01

The concept of punctured convolutional codes is extended by punctuating a low-rate 1/N code periodically with period P to obtain a family of codes with rate P/(P + l), where l can be varied between 1 and (N - 1)P. A rate-compatibility restriction on the puncturing tables ensures that all code bits of high rate codes are used by the lower-rate codes. This allows transmission of incremental redundancy in ARQ/FEC (automatic repeat request/forward error correction) schemes and continuous rate variation to change from low to high error protection within a data frame. Families of RCPC codes with rates between 8/9 and 1/4 are given for memories M from 3 to 6 (8 to 64 trellis states) together with the relevant distance spectra. These codes are almost as good as the best known general convolutional codes of the respective rates. It is shown that the same Viterbi decoder can be used for all RCPC codes of the same M. The application of RCPC codes to hybrid ARQ/FEC schemes is discussed for Gaussian and Rayleigh fading channels using channel-state information to optimize throughput.

A High Pressure Flowing Oil Switch For Gigawatt, Repetitive Applications

DTIC Science & Technology

2005-06-01

for testing the high pressure switch concept under repetitive pulse conditions is a 4.8 Ω, 70 ns water pulse forming line (PFL). The water PFL is...Cox Instruments. A pair of Hedland variable area flow sensors monitored relative flow rates in the two oil lines that fed the high pressure switch . High... pressure switch was tested under both single shot and repetitive conditions over a range of pressures, flow rates and temperatures. The primary

Demonstration of a Fiber Optic Regression Probe in a High-Temperature Flow

NASA Technical Reports Server (NTRS)

Korman, Valentin; Polzin, Kurt

2011-01-01

The capability to provide localized, real-time monitoring of material regression rates in various applications has the potential to provide a new stream of data for development testing of various components and systems, as well as serving as a monitoring tool in flight applications. These applications include, but are not limited to, the regression of a combusting solid fuel surface, the ablation of the throat in a chemical rocket or the heat shield of an aeroshell, and the monitoring of erosion in long-life plasma thrusters. The rate of regression in the first application is very fast, while the second and third are increasingly slower. A recent fundamental sensor development effort has led to a novel regression, erosion, and ablation sensor technology (REAST). The REAST sensor allows for measurement of real-time surface erosion rates at a discrete surface location. The sensor is optical, using two different, co-located fiber-optics to perform the regression measurement. The disparate optical transmission properties of the two fiber-optics makes it possible to measure the regression rate by monitoring the relative light attenuation through the fibers. As the fibers regress along with the parent material in which they are embedded, the relative light intensities through the two fibers changes, providing a measure of the regression rate. The optical nature of the system makes it relatively easy to use in a variety of harsh, high temperature environments, and it is also unaffected by the presence of electric and magnetic fields. In addition, the sensor could be used to perform optical spectroscopy on the light emitted by a process and collected by fibers, giving localized measurements of various properties. The capability to perform an in-situ measurement of material regression rates is useful in addressing a variety of physical issues in various applications. An in-situ measurement allows for real-time data regarding the erosion rates, providing a quick method for empirically anchoring any analysis geared towards lifetime qualification. Erosion rate data over an operating envelope could also be useful in the modeling detailed physical processes. The sensor has been embedded in many regressing media to demonstrate the capabilities in a number of regressing environments. In the present work, sensors were installed in the eroding/regressing throat region of a converging-diverging flow, with the working gas heated to high temperatures by means of a high-pressure arc discharge at steady-state discharge power levels up to 500 kW. The amount of regression observed in each material sample was quantified using a later profilometer, which was compared to the in-situ erosion measurements to demonstrate the efficacy of the measurement technique in very harsh, high-temperature environments.

Methane oxidation in an intensively cropped tropical rice field soil under long-term application of organic and mineral fertilizers.

PubMed

Nayak, D R; Babu, Y Jagadeesh; Datta, A; Adhya, T K

2007-01-01

Methane (CH4) oxidation is the only known biological sink process for mitigating atmospheric and terrestrial emissions of CH4, a major greenhouse gas. Methane oxidation in an alluvial soil planted to rice (Oryza sativa L.) under long-term application of organic (compost with a C/N ratio of 21.71), and mineral fertilizers was measured in a field-cum-laboratory incubation study. Oxidation rates were quantified in terms of decrease in the concentration of CH4 in the headspace of incubation vessels and expressed as half-life (t(1)2) values. Methane oxidation rates significantly differed among the treatments and growth stages of the rice crop. Methane oxidation rates were high at the maximum tillering and maturity stages, whereas they were low at grain-filling stage. Methane oxidation was low (t(1)2) = 15.76 d) when provided with low concentration of CH4. On the contrary, high concentration of CH4 resulted in faster oxidation (t(1)2) = 6.67 d), suggesting the predominance of "low affinity oxidation" in rice fields. Methane oxidation was stimulated following the application of mineral fertilizers or compost implicating nutrient limitation as one of the factors affecting the process. Combined application of compost and mineral fertilizer, however, inhibited CH4 oxidation probably due to N immobilization by the added compost. The positive effect of mineral fertilizer on CH4 oxidation rate was evident only at high CH4 concentration (t(1)2 = 4.80 d), while at low CH4 concentration their was considerable suppression (t(1) = 17.60 d). Further research may reveal that long-term application of fertilizers, organic or inorganic, may not inhibit CH4 oxidation.

A 400 KHz line rate 2048 pixel modular SWIR linear array for earth observation applications

NASA Astrophysics Data System (ADS)

Anchlia, Ankur; Vinella, Rosa M.; Wouters, Kristof; Gielen, Daphne; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; van der Zanden, Koen; Vermeiren, Jan; Merken, Patrick

2015-10-01

In this paper, we report about a family of linear imaging FPAs sensitive in the [0.9 - 1.7um] band, developed for high speed applications such as LIDAR, wavelength references and OCT analyzers and also for earth observation applications. Fast linear FPAs can also be used in a wide variety of terrestrial applications, including high speed sorting, electro- and photo-luminesce and medical applications. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. In principle, this concept can be extended to any multiple of 512 pixels, the limiting factor being the pixel yield of long InGaAs arrays and the CTE differences in the hybrid setup. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long-linear array to run at a high line rate of 400 KHz irrespective of the array length, which limits the line rate in a traditional linear array. The pixel has a pitch of 12.5um. The detector frontend is based on CTIA (Capacitor Trans-impedance Amplifier), having 5 selectable integration capacitors giving full well from 62x103e- (gain0) to 40x106e- (gain4). An auto-zero circuit limits the detector bias non-uniformity to 5-10mV across broad intensity levels, limiting the input referred dark signal noise to 20e-rms for Tint=3ms at room temperature. An on-chip CDS that follows the CTIA facilitates removal of Reset/KTC noise, CTIA offsets and most of the 1/f noise. The measured noise of the ROIC is 35e-rms in gain0. At a master clock rate of 60MHz and a minimum integration time of 1.4us, the FPAs reach the highest line rate of 400 KHz.

Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

PubMed Central

Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

2015-01-01

Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s−1 is generated at 22.3 eV, with 5 × 10−5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications. PMID:26067922

High resolution gamma-ray spectroscopy at high count rates with a prototype High Purity Germanium detector

NASA Astrophysics Data System (ADS)

Cooper, R. J.; Amman, M.; Vetter, K.

2018-04-01

High-resolution gamma-ray spectrometers are required for applications in nuclear safeguards, emergency response, and fundamental nuclear physics. To overcome one of the shortcomings of conventional High Purity Germanium (HPGe) detectors, we have developed a prototype device capable of achieving high event throughput and high energy resolution at very high count rates. This device, the design of which we have previously reported on, features a planar HPGe crystal with a reduced-capacitance strip electrode geometry. This design is intended to provide good energy resolution at the short shaping or digital filter times that are required for high rate operation and which are enabled by the fast charge collection afforded by the planar geometry crystal. In this work, we report on the initial performance of the system at count rates up to and including two million counts per second.

UWB Technology and Applications on Space Exploration

NASA Technical Reports Server (NTRS)

Ngo, Phong; Phan, Chau; Gross, Julia; Dusl, John; Ni, Jianjun; Rafford, Melinda

2006-01-01

Ultra-wideband (UWB), also known as impulse or carrier-free radio technology, is one promising new technology. In February 2002, the Federal Communications Commission (FCC) approved the deployment of this technology. It is increasingly recognized that UWB technology holds great potential to provide significant benefits in many terrestrial and space applications such as precise positioning/tracking and high data rate mobile wireless communications. This talk presents an introduction to UWB technology and some applications on space exploration. UWB is characterized by several uniquely attractive features, such as low impact on other RF systems due to its extremely low power spectral densities, immunity to interference from narrow band RF systems due to its ultra-wide bandwidth, multipath immunity to fading due to ample multipath diversity, capable of precise positioning due to fine time resolution, capable of high data rate multi-channel performance. The related FCC regulations, IEEE standardization efforts and industry activities also will be addressed in this talk. For space applications, some projects currently under development at NASA Johnson Space Center will be introduced. These include the UWB integrated communication and tracking system for Lunar/Mars rover and astronauts, UWB-RFID ISS inventory tracking, and UWB-TDOA close-in high resolution tracking for potential applications on robonaut.

Automated construction of an intraoperative high-dose-rate treatment plan library for the Varian brachytherapy treatment planning system.

PubMed

Deufel, Christopher L; Furutani, Keith M; Dahl, Robert A; Haddock, Michael G

2016-01-01

The ability to create treatment plans for intraoperative high-dose-rate (IOHDR) brachytherapy is limited by lack of imaging and time constraints. An automated method for creation of a library of high-dose-rate brachytherapy plans that can be used with standard planar applicators in the intraoperative setting is highly desirable. Nonnegative least squares algebraic methods were used to identify dwell time values for flat, rectangular planar applicators. The planar applicators ranged in length and width from 2 cm to 25 cm. Plans were optimized to deliver an absorbed dose of 10 Gy to three different depths from the patient surface: 0 cm, 0.5 cm, and 1.0 cm. Software was written to calculate the optimized dwell times and insert dwell times and positions into a .XML plan template that can be imported into the Varian brachytherapy treatment planning system. The user may import the .XML template into the treatment planning system in the intraoperative setting to match the patient applicator size and prescribed treatment depth. A total of 1587 library plans were created for IOHDR brachytherapy. Median plan generation time was approximately 1 minute per plan. Plan dose was typically 100% ± 1% (mean, standard deviation) of the prescribed dose over the entire length and width of the applicator. Plan uniformity was best for prescription depths of 0 cm and 0.5 cm from the patient surface. An IOHDR plan library may be created using automated methods. Thousands of plan templates may be optimized and prepared in a few hours to accommodate different applicator sizes and treatment depths and reduce treatment planning time. The automated method also enforces dwell time symmetry for symmetrical applicator geometries, which simplifies quality assurance. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

High-speed optical 3D sensing and its applications

NASA Astrophysics Data System (ADS)

Watanabe, Yoshihiro

2016-12-01

This paper reviews high-speed optical 3D sensing technologies for obtaining the 3D shape of a target using a camera. The focusing speed is from 100 to 1000 fps, exceeding normal camera frame rates, which are typically 30 fps. In particular, contactless, active, and real-time systems are introduced. Also, three example applications of this type of sensing technology are introduced, including surface reconstruction from time-sequential depth images, high-speed 3D user interaction, and high-speed digital archiving.

Toxicity of pesticides associated with potato production, including soil fumigants, to snapping turtle eggs (Chelydra serpentina).

PubMed

de Solla, Shane Raymond; Palonen, Kimberley Elizabeth; Martin, Pamela Anne

2014-01-01

Turtles frequently oviposit in soils associated with agriculture and, thus, may be exposed to pesticides or fertilizers. The toxicity of a pesticide regime that is used for potato production in Ontario on the survivorship of snapping turtle (Chelydra serpentina) eggs was evaluated. The following treatments were applied to clean soil: 1) a mixture of the pesticides chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos, and 2) the soil fumigant metam sodium. Turtle eggs were incubated in soil in outdoor plots in which these mixtures were applied at typical and higher field application rates, where the eggs were subject to ambient temperature and weather conditions. The pesticide mixture consisting of chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos did not affect survivorship, deformities, or body size at applications up to 10 times the typical field application rates. Hatching success ranged between 87% and 100% for these treatments. Metam sodium was applied at 0.1¯ times, 0.3¯ times, 1 times, and 3 times field application rates. Eggs exposed to any application of metam sodium had 100% mortality. At typical field application rates, the chemical regime associated with potato production does not appear to have any detrimental impacts on turtle egg development, except for the use of the soil fumigant metam sodium, which is highly toxic to turtle eggs at the lowest recommended application rate. © 2013 SETAC.

Ponderosa pine seeding trials in west-side Sierra Nevada clearcuts: some early results

Treesearch

Robert L. Neal

1975-01-01

In direct-seeding trials on the Challenge Experimental Forest, Yuba County, California, 27 combinations of seeding rates, aspect, and site treatment were tested. The best results were obtained on northerly aspects on unburned mechanically disturbed seedbeds with a high proportion of exposed mineral soil when seed application rates were high. Sowing at least 1 pound of...

New approaches in clinical application of laser-driven ionizing radiation

NASA Astrophysics Data System (ADS)

Hideghéty, Katalin; Szabó, Rita Emilia; Polanek, Róbert; Szabó, Zoltán.; Brunner, Szilvia; Tőkés, Tünde

2017-05-01

The planned laser-driven ionizing beams (photon, very high energy electron, proton, carbon ion) at laser facilities have the unique property of ultra-high dose rate (>Gy/s-10), short pulses, and at ELI-ALPS high repetition rate, carry the potential to develop novel laser-driven methods towards compact hospital-based clinical application. The enhanced flexibility in particle and energy selection, the high spatial and time resolution and extreme dose rate could be highly beneficial in radiotherapy. These approaches may increase significantly the therapeutic index over the currently available advanced radiation oncology methods. We highlight two nuclear reactionbased binary modalities and the planned radiobiology research. Boron Neutron Capture Therapy is an advanced cell targeted modality requiring 10B enriched boron carrier and appropriate neutron beam. The development of laser-based thermal and epithermal neutron source with as high as 1010 fluence rate could enhance the research activity in this promising field. Boron-Proton Fusion reaction is as well as a binary approach, where 11B containing compounds are accumulated into the cells, and the tumour selectively irradiated with protons. Due to additional high linear energy transfer alpha particle release of the BPFR and the maximum point of the Bragg-peak is increased, which result in significant biological effect enhancement. Research at ELI-ALPS on detection of biological effect differences of modified or different quality radiation will be presented using recently developed zebrafish embryo and rodent models.

Sensor-based demand controlled ventilation

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

De Almeida, A.T.; Fisk, W.J.

In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation ratesmore » are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.« less

Lithium-thionyl chloride battery

NASA Astrophysics Data System (ADS)

Wong, D.; Bowden, W.; Hamilton, N.; Cubbison, D.; Dey, A. N.

1981-04-01

The main objective is to develop, fabricate, test, and deliver safe high rate lithium-thionyl chloride batteries for various U.S. Army applications such as manpack ratios and GLLD Laser Designators. We have devoted our efforts in the following major areas: (1) Optimization of the spirally wound D cell for high rate applications, (2) Development of a 3 inch diameter flat cylindrical cell for the GLLD laser designator application, and (3) Investigation of the reduction mechanism of SOCl2. The rate capability of the spirally wound D cell previously developed by us has been optimized for both the manpack radio (BA5590) battery and GLLD laser designator battery application in this program. A flat cylindrical cell has also been developed for the GLLD laser designator application. It is 3 inches in diameter and 0.9 inch in height with extremely low internal cell impedance that minimizes cell heating and polarization on the GLLD load. Typical cell capacity was found to be 18.0-19.0 Ahr with a few cells delivering up to about 21.0 Ahr on the GLLD test load. Study of the reduction mechanism of SOCl2 using electrochemical and spectroscopic techniques has also been carried out in this program which may be directly relevant to the intrinsic safety of the system.

Optical resolution photoacoustic microscopy using novel high-repetition-rate passively Q-switched microchip and fiber lasers.

PubMed

Shi, Wei; Kerr, Shaun; Utkin, Ilya; Ranasinghesagara, Janaka; Pan, Lei; Godwal, Yogesh; Zemp, Roger J; Fedosejevs, Robert

2010-01-01

Optical-resolution photoacoustic microscopy (OR-PAM) is a novel imaging technology for visualizing optically absorbing superficial structures in vivo with lateral spatial resolution determined by optical focusing rather than acoustic detection. Since scanning of the illumination spot is required, OR-PAM imaging speed is limited by both scanning speed and laser pulse repetition rate. Unfortunately, lasers with high repetition rates and suitable pulse durations and energies are not widely available and can be cost-prohibitive and bulky. We are developing compact, passively Q-switched fiber and microchip laser sources for this application. The properties of these lasers are discussed, and pulse repetition rates up to 100 kHz are demonstrated. OR-PAM imaging was conducted using a previously developed photoacoustic probe, which enabled flexible scanning of the focused output of the lasers. Phantom studies demonstrate the ability to image with lateral spatial resolution of 7±2 μm with the microchip laser system and 15±5 μm with the fiber laser system. We believe that the high pulse repetition rates and the potentially compact and fiber-coupled nature of these lasers will prove important for clinical imaging applications where real-time imaging performance is essential.

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

Song, Bo; Nelson, Kevin; Lipinski, Ronald J.

Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-temperature high-strain-rate performance are needed for understanding high-speed impacts in severe elevated-temperature environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain-rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. Current high-temperature Kolsky compression bar techniques are not capable of obtaining satisfactory high-temperature high-strain-rate stress-strain response of thin iridium specimens investigated in this study. We analyzedmore » the difficulties encountered in high-temperature Kolsky compression bar testing of thin iridium alloy specimens. Appropriate modifications were made to the current high-temperature Kolsky compression bar technique to obtain reliable compressive stress-strain response of an iridium alloy at high strain rates (300 – 10000 s -1) and temperatures (750°C and 1030°C). Uncertainties in such high-temperature high-strain-rate experiments on thin iridium specimens were also analyzed. The compressive stress-strain response of the iridium alloy showed significant sensitivity to strain rate and temperature.« less

Wide-band (2.5 - 10.5 µm), high-frame rate IRFPAs based on high-operability MCT on silicon

NASA Astrophysics Data System (ADS)

Crosbie, Michael J.; Giess, Jean; Gordon, Neil T.; Hall, David J.; Hails, Janet E.; Lees, David J.; Little, Christopher J.; Phillips, Tim S.

2010-04-01

We have previously presented results from our mercury cadmium telluride (MCT, Hg1-xCdxTe) growth on silicon substrate technology for different applications, including negative luminescence, long waveband and mid/long dual waveband infrared imaging. In this paper, we review recent developments in QinetiQ's combined molecular beam epitaxy (MBE) and metal-organic vapor phase epitaxy (MOVPE) MCT growth on silicon; including MCT defect density, uniformity and reproducibility. We also present a new small-format (128 x 128) focal plane array (FPA) for high frame-rate applications. A custom high-speed readout integrated circuit (ROIC) was developed with a large pitch and large charge storage aimed at producing a very high performance FPA (NETD ~10mK) operating at frame rates up to 2kHz for the full array. The array design allows random addressing and this allows the maximum frame rate to be increased as the window size is reduced. A broadband (2.5-10.5 μm) MCT heterostructure was designed and grown by the MBE/MOVPE technique onto silicon substrates. FPAs were fabricated using our standard techniques; wet-etched mesa diodes passivated with epitaxial CdTe and flip-chip bonded to the ROIC. The resulting focal plane arrays were characterized at the maximum frame rate and shown to have the high operabilities and low NETD values characteristic of our LWIR MCT on silicon technology.

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

Song, B.; Nelson, K.; Lipinski, R.

Iridium alloys have superior strength and ductility at elevated temperatures, making them useful as structural materials for certain high-temperature applications. However, experimental data on their high-strain -rate performance are needed for understanding high-speed impacts in severe environments. Kolsky bars (also called split Hopkinson bars) have been extensively employed for high-strain -rate characterization of materials at room temperature, but it has been challenging to adapt them for the measurement of dynamic properties at high temperatures. In our study, we analyzed the difficulties encountered in high-temperature Kolsky bar testing of thin iridium alloy specimens in compression. We made appropriate modifications using themore » current high-temperature Kolsky bar technique in order to obtain reliable compressive stress–strain response of an iridium alloy at high-strain rates (300–10 000 s -1) and temperatures (750 and 1030°C). The compressive stress–strain response of the iridium alloy showed significant sensitivity to both strain rate and temperature.« less

Soft computing prediction of economic growth based in science and technology factors

NASA Astrophysics Data System (ADS)

Marković, Dušan; Petković, Dalibor; Nikolić, Vlastimir; Milovančević, Miloš; Petković, Biljana

2017-01-01

The purpose of this research is to develop and apply the Extreme Learning Machine (ELM) to forecast the gross domestic product (GDP) growth rate. In this study the GDP growth was analyzed based on ten science and technology factors. These factors were: research and development (R&D) expenditure in GDP, scientific and technical journal articles, patent applications for nonresidents, patent applications for residents, trademark applications for nonresidents, trademark applications for residents, total trademark applications, researchers in R&D, technicians in R&D and high-technology exports. The ELM results were compared with genetic programming (GP), artificial neural network (ANN) and fuzzy logic results. Based upon simulation results, it is demonstrated that ELM has better forecasting capability for the GDP growth rate.

MuTRiG: a mixed signal Silicon Photomultiplier readout ASIC with high timing resolution and gigabit data link

NASA Astrophysics Data System (ADS)

Chen, H.; Briggl, K.; Eckert, P.; Harion, T.; Munwes, Y.; Shen, W.; Stankova, V.; Schultz-Coulon, H. C.

2017-01-01

MuTRiG is a mixed signal Silicon Photomultiplier readout ASIC designed in UMC 180 nm CMOS technology for precise timing and high event rate applications in high energy physics experiments and medical imaging. It is dedicated to the readout of the scintillating fiber detector and the scintillating tile detector of the Mu3e experiment. The MuTRiG chip extends the excellent timing performance of the STiCv3 chip with a fast digital readout for high rate applications. The high timing performance of the fully differential SiPM readout channels and 50 ps time binning TDCs are complemented by an upgraded digital readout logic and a 1.28 Gbps LVDS serial data link. The design of the chip and the characterization results of the analog front-end, TDC and the LVDS data link are presented.

Single-pass high harmonic generation at high repetition rate and photon flux

NASA Astrophysics Data System (ADS)

Hädrich, Steffen; Rothhardt, Jan; Krebs, Manuel; Demmler, Stefan; Klenke, Arno; Tünnermann, Andreas; Limpert, Jens

2016-09-01

Sources of short wavelength radiation with femtosecond to attosecond pulse durations, such as synchrotrons or free electron lasers, have already made possible numerous, and will facilitate more, seminal studies aimed at understanding atomic and molecular processes on fundamental length and time scales. Table-top sources of coherent extreme ultraviolet to soft x-ray radiation enabled by high harmonic generation (HHG) of ultrashort pulse lasers have also gained significant attention in the last few years due to their enormous potential for addressing a plethora of applications, therefore constituting a complementary source to large-scale facilities (synchrotrons and free electron lasers). Ti:sapphire based laser systems have been the workhorses for HHG for decades, but are limited in repetition rate and average power. On the other hand, it has been widely recognized that fostering applications in fields such as photoelectron spectroscopy and microscopy, coincidence detection, coherent diffractive imaging and frequency metrology requires a high repetition rate and high photon flux HHG sources. In this article we will review recent developments in realizing the demanding requirement of producing a high photon flux and repetition rate at the same time. Particular emphasis will be put on suitable ultrashort pulse and high average power lasers, which directly drive harmonic generation without the need for external enhancement cavities. To this end we describe two complementary schemes that have been successfully employed for high power fiber lasers, i.e. optical parametric chirped pulse amplifiers and nonlinear pulse compression. Moreover, the issue of phase-matching in tight focusing geometries will be discussed and connected to recent experiments. We will highlight the latest results in fiber laser driven high harmonic generation that currently produce the highest photon flux of all existing sources. In addition, we demonstrate the first promising applications and discuss the future direction and challenges of this new type of HHG source.

Radiological assessment of target materials for accelerator transmutation of waste (ATW) applications

NASA Astrophysics Data System (ADS)

Vickers, Linda Diane

This dissertation issues the first published document of the radiation absorbed dose rate (rad-h-1) to tissue from radioactive spallation products in Ta, W, Pb, Bi, and LBE target materials used in Accelerator Transmutation of Waste (ATW) applications. No previous works have provided an estimate of the absorbed dose rate (rad-h-1) from activated targets for ATW applications. The results of this dissertation are useful for planning the radiological safety assessment to personnel, and for the design, construction, maintenance, and disposition of target materials of high-energy particle accelerators for ATW applications (Charlton, 1996). In addition, this dissertation provides the characterization of target materials of high-energy particle accelerators for the parameters of: (1) spallation neutron yield (neutrons/proton), (2) spallation products yield (nuclides/proton), (3) energy-dependent spallation neutron fluence distribution, (4) spallation neutron flux, (5) identification of radioactive spallation products for consideration in safety of personnel to high radiation dose rates, and (6) identification of the optimum geometrical dimensions for the target applicable to the maximum radial spallation neutron leakage from the target. Pb and Bi target materials yielded the lowest absorbed dose rates (rad-h -1) for a 10-year irradiation/50-year decay scheme, and would be the preferred target materials for consideration of the radiological safety of personnel during ATW operations. A beneficial characteristic of these target materials is that they do not produce radioactive transuranic isotopes, which have very long half-lives and require special handling and disposition requirements. Furthermore, the targets are not considered High-Level Waste (HLW) such as reactor spent fuel for disposal purposes. It is a basic ATW system requirement that the spallation target after it has been expended should be disposable as Class C low-level radioactive waste. Therefore, the disposal of Pb and Bi targets would be optimally beneficial to the economy and environment. Future studies should relate the target performance to other system parameters, specifically solid and liquid blanket systems that contain the radioactive waste to be transmuted. The methodology of this dissertation may be applied to any target material of a high-energy particle accelerator.

Facile synthesis of nickel-cobalt double hydroxide nanosheets with high rate capability for application in supercapacitor

NASA Astrophysics Data System (ADS)

Wang, Minmin; Xue, Junying; Zhang, Fangming; Ma, Wenle; Cui, Hongtao

2015-02-01

In this work, nickel-cobalt double hydroxide nanosheets with high rate capability are prepared by a facile epoxide precipitation route. The synthetic procedure includes an oxidization step using ammonium persulfate as oxidant and a precipitation step using propylene oxide as precipitation agent. As shown in the results of electrochemical characterization, high specific capacitance of 2548 F g-1 for this material can be obtained at current density of 0.9 A g-1 in aqueous solution of 3 mol L-1 KOH. It is surprising to notice that the capacitance of material still remains 1587 F g-1 at high current density of 35.7 A g-1. These results demonstrate that the as-prepared nickel-cobalt double hydroxide nanosheets are promising electrode material for supercapacitor application as a primary power source.

Doping-enhanced radiative efficiency enables lasing in unpassivated GaAs nanowires

PubMed Central

Burgess, Tim; Saxena, Dhruv; Mokkapati, Sudha; Li, Zhe; Hall, Christopher R.; Davis, Jeffrey A.; Wang, Yuda; Smith, Leigh M.; Fu, Lan; Caroff, Philippe; Tan, Hark Hoe; Jagadish, Chennupati

2016-01-01

Nanolasers hold promise for applications including integrated photonics, on-chip optical interconnects and optical sensing. Key to the realization of current cavity designs is the use of nanomaterials combining high gain with high radiative efficiency. Until now, efforts to enhance the performance of semiconductor nanomaterials have focused on reducing the rate of non-radiative recombination through improvements to material quality and complex passivation schemes. Here we employ controlled impurity doping to increase the rate of radiative recombination. This unique approach enables us to improve the radiative efficiency of unpassivated GaAs nanowires by a factor of several hundred times while also increasing differential gain and reducing the transparency carrier density. In this way, we demonstrate lasing from a nanomaterial that combines high radiative efficiency with a picosecond carrier lifetime ready for high speed applications. PMID:27311597

Chemical matricectomy with sodium hydroxide: long-term follow-up results.

PubMed

Bostanci, Seher; Kocyigit, Pelin; Parlak, Nehir; Gungor, Hilayda Karakok

2014-11-01

Chemical matricectomy with sodium hydroxide is a method being used successfully in the treatment of ingrown toenail. In this study, it was aimed to evaluate long-term recurrence rates after chemical matricectomy using sodium hydroxide application of different durations. Two hundred two patients with ingrown nail edges were treated with either 1-minute (Group 1) or 2-minute (Group 2) applications of sodium hydroxide matricectomy. All patients were followed for at least 2 years. Chemical matricectomy with sodium hydroxide was applied to a total of 585 nail edges of 202 cases. The overall recurrence rates in Group 1 and Group 2 were 6.4% and 7.1%, respectively, during the average 7.5-year follow-up period. No statistically significant differences were detected in terms of recurrence between the 2 groups (p = .73). Chemical matricectomy with sodium hydroxide is an easy method in the treatment of ingrown nails, with low morbidity and high success rates. There was no difference between 1-minute and 2-minute applications in terms of recurrence during the long-term follow-up. Chemical matricectomy with 1-minute application of sodium hydroxide showed high success in terms of long-term follow-up results.

All-fibre photonic signal generator for attosecond timing and ultralow-noise microwave

PubMed Central

Jung, Kwangyun; Kim, Jungwon

2015-01-01

High-impact frequency comb applications that are critically dependent on precise pulse timing (i.e., repetition rate) have recently emerged and include the synchronization of X-ray free-electron lasers, photonic analogue-to-digital conversion and photonic radar systems. These applications have used attosecond-level timing jitter of free-running mode-locked lasers on a fast time scale within ~100 μs. Maintaining attosecond-level absolute jitter over a significantly longer time scale can dramatically improve many high-precision comb applications. To date, ultrahigh quality-factor (Q) optical resonators have been used to achieve the highest-level repetition-rate stabilization of mode-locked lasers. However, ultrahigh-Q optical-resonator-based methods are often fragile, alignment sensitive and complex, which limits their widespread use. Here we demonstrate a fibre-delay line-based repetition-rate stabilization method that enables the all-fibre photonic generation of optical pulse trains with 980-as (20-fs) absolute r.m.s. timing jitter accumulated over 0.01 s (1 s). This simple approach is based on standard off-the-shelf fibre components and can therefore be readily used in various comb applications that require ultra-stable microwave frequency and attosecond optical timing. PMID:26531777

Activated carbon derived from melaleuca barks for outstanding high-rate supercapacitors

NASA Astrophysics Data System (ADS)

Luo, Qiu-Ping; Huang, Liang; Gao, Xiang; Cheng, Yongliang; Yao, Bin; Hu, Zhimi; Wan, Jun; Xiao, Xu; Zhou, Jun

2015-07-01

Activated carbon (AC) was prepared via carbonizing melaleuca bark in an argon atmosphere at 600 °C followed with KOH activation for high-rate supercapacitors. This AC electrode has a high capacitance of 233 F g-1 at a scan rate of 2 mV s-1 and an excellent rate capability of ˜80% when increasing the sweep rate from 2 to 500 mV s-1. The symmetric supercapacitor assembled by the above electrode can deliver a high energy density of 4.2 Wh kg-1 with a power density of 1500 W kg-1 when operated in the voltage range of 0-1 V in 1 M H2SO4 aqueous electrolyte while maintaining great cycling stability (less than 5% capacitance loss after 10 000 cycles at sweep rate of 100 mV s-1). All the outstanding electrochemical performances make this AC electrode a promising candidate for potential energy storage application.

Demonstration of a high repetition rate capillary discharge waveguide

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

Gonsalves, A. J., E-mail: ajgonsalves@lbl.gov; Pieronek, C.; Daniels, J.

2016-01-21

A hydrogen-filled capillary discharge waveguide operating at kHz repetition rates is presented for parameters relevant to laser plasma acceleration (LPA). The discharge current pulse was optimized for erosion mitigation with laser guiding experiments and MHD simulation. Heat flow simulations and measurements showed modest temperature rise at the capillary wall due to the average heat load at kHz repetition rates with water-cooled capillaries, which is promising for applications of LPAs such as high average power radiation sources.

Advanced modulation technology development for earth station demodulator applications. Coded modulation system development

NASA Technical Reports Server (NTRS)

Miller, Susan P.; Kappes, J. Mark; Layer, David H.; Johnson, Peter N.

1990-01-01

A jointly optimized coded modulation system is described which was designed, built, and tested by COMSAT Laboratories for NASA LeRC which provides a bandwidth efficiency of 2 bits/s/Hz at an information rate of 160 Mbit/s. A high speed rate 8/9 encoder with a Viterbi decoder and an Octal PSK modem are used to achieve this. The BER performance is approximately 1 dB from the theoretically calculated value for this system at a BER of 5 E-7 under nominal conditions. The system operates in burst mode for downlink applications and tests have demonstrated very little degradation in performance with frequency and level offset. Unique word miss rate measurements were conducted which demonstrate reliable acquisition at low values of Eb/No. Codec self tests have verified the performance of this subsystem in a stand alone mode. The codec is capable of operation at a 200 Mbit/s information rate as demonstrated using a codec test set which introduces noise digitally. The measured performance is within 0.2 dB of the computer simulated predictions. A gate array implementation of the most time critical element of the high speed Viterbi decoder was completed. This gate array add-compare-select chip significantly reduces the power consumption and improves the manufacturability of the decoder. This chip has general application in the implementation of high speed Viterbi decoders.

Cascaded VLSI neural network architecture for on-line learning

NASA Technical Reports Server (NTRS)

Thakoor, Anilkumar P. (Inventor); Duong, Tuan A. (Inventor); Daud, Taher (Inventor)

1992-01-01

High-speed, analog, fully-parallel, and asynchronous building blocks are cascaded for larger sizes and enhanced resolution. A hardware compatible algorithm permits hardware-in-the-loop learning despite limited weight resolution. A computation intensive feature classification application was demonstrated with this flexible hardware and new algorithm at high speed. This result indicates that these building block chips can be embedded as an application specific coprocessor for solving real world problems at extremely high data rates.

Cascaded VLSI neural network architecture for on-line learning

NASA Technical Reports Server (NTRS)

Duong, Tuan A. (Inventor); Daud, Taher (Inventor); Thakoor, Anilkumar P. (Inventor)

1995-01-01

High-speed, analog, fully-parallel and asynchronous building blocks are cascaded for larger sizes and enhanced resolution. A hardware-compatible algorithm permits hardware-in-the-loop learning despite limited weight resolution. A comparison-intensive feature classification application has been demonstrated with this flexible hardware and new algorithm at high speed. This result indicates that these building block chips can be embedded as application-specific-coprocessors for solving real-world problems at extremely high data rates.

Flexible asymmetric supercapacitors with high energy and high power density in aqueous electrolytes

NASA Astrophysics Data System (ADS)

Cheng, Yingwen; Zhang, Hongbo; Lu, Songtao; Varanasi, Chakrapani V.; Liu, Jie

2013-01-01

Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s-1 to 500 mV s-1. Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg-1) under high power density (7.8 kW kg-1) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required.Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s-1 to 500 mV s-1. Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg-1) under high power density (7.8 kW kg-1) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr33136e

An Investigation of the High Rate Volumetric Properties of Snow.

DTIC Science & Technology

1981-11-01

experimental data. A number of applications are thenLi Investigated. These applications Include vehicle mobility In shallow anddeep snowpack, steady shockwaves...applications include vehicle mobility : in cb11 low and deep sjnowpack, ,,teady shockwaves, and noiistieady oe.av. -An na, 1, -lromacgnetic -;Lrus...VEHICLE MOBILITY ........................ 48 . III.A. Introductory Remarks .................................... 48 111.0. Tracked Vehicle Mobility in

[Effects of nitrogen application level on soil nitrate accumulation and ammonia volatilization in high-yielding wheat field].

PubMed

Wang, Dong; Yu, Zhenwen; Yu, Wenming; Shi, Yu; Zhou, Zhongxin

2006-09-01

The study showed that during the period from sowing to pre-wintering, the soil nitrate in high-yielding wheat field moved down to deeper layers, and accumulated in the layers below 140 cm. An application rate of 96-168 kg N x hm(-2) increased the nitrate content in 0-60 cm soil layer and the wheat grain yield and its protein content, and decreased the proportion of apparent N loss to applied N and the ammonia volatilization loss from basal nitrogen. Applying 240 kg N x hm(-2) promoted the downward movement of soil nitrate and its accumulation in deeper layers, increased the proportion of apparent N loss to applied N and the ammonia volatilization loss from basal nitrogen, had no significant effect on the protein content of wheat grain, but decreased the grain yield. The appropriate application rate of nitrogen on high-yielding wheat field was 132-204 kg N x hm(-2).

Constructing, connecting and soldering nanostructures by environmental electron beam deposition

NASA Astrophysics Data System (ADS)

Mølhave, Kristian; Nørgaard Madsen, Dorte; Dohn, Søren; Bøggild, Peter

2004-08-01

Highly conductive nanoscale deposits with solid gold cores can be made by electron beam deposition in an environmental scanning electron microscope (ESEM), suggesting the method to be used for constructing, connecting and soldering nanostructures. This paper presents a feasibility study for such applications. We identify several issues related to contamination and unwanted deposition, relevant for deposition in both vacuum (EBD) and environmental conditions (EEBD). We study relations between scan rate, deposition rate, angle and line width for three-dimensional structures. Furthermore, we measure the conductivity of deposits containing gold cores, and find these structures to be highly conductive, approaching the conductivity of solid gold and capable of carrying high current densities. Finally, we study the use of the technique for soldering nanostructures such as carbon nanotubes. Based on the presented results we are able to estimate limits for the applicability of the method for the various applications, but also demonstrate that it is a versatile and powerful tool for nanotechnology within these limits.

Comparison of greenhouse gas emissions from rice paddy fields under different nitrogen fertilization loads in Chongming Island, Eastern China.

PubMed

Zhang, Xianxian; Yin, Shan; Li, Yinsheng; Zhuang, Honglei; Li, Changsheng; Liu, Chunjiang

2014-02-15

Rice is one of the major crops of southern China and Southeast Asia. Rice paddies are one of the largest agricultural greenhouse gas (GHG) sources in this region because of the application of large quantities of nitrogen (N) fertilizers to the plants. In particular, the production of methane (CH4) is a concern. Investigating a reasonable amount of fertilizers to apply to plants is essential to maintaining high yields while reducing GHG emissions. In this study, three levels of fertilizer application [high (300 kg N/ha), moderate (210 kg N/ha), and low (150 kg N/ha)] were designed to examine the effects of variation in N fertilizer application rate on carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions from the paddy fields in Chongming Island, Shanghai, China. The high level (300 kg N/ha) represented the typical practice adopted by the local farmers in the area. Maximum amounts of CH4 and N2O fluxes were observed upon high-level fertilizer application in the plots. Cumulative N2O emissions of 23.09, 40.10, and 71.08 mg N2O/m(2) were observed over the growing season in 2011 under the low-, moderate-, and high-level applications plots, respectively. The field data also indicated that soil temperatures at 5 and 10 cm soil depths significantly affected soil respiration; the relationship between Rs and soil temperature in this study could be described by an exponential model. Our study showed that reducing the high rate of fertilizer application is a feasible way of attenuating the global-warming potential while maintaining the optimum yield for the studied paddy fields. Copyright © 2013 Elsevier B.V. All rights reserved.

Application of an Artificial Neural Network to the Prediction of OH Radical Reaction Rate Constants for Evaluating Global Warming Potential.

PubMed

Allison, Thomas C

2016-03-03

Rate constants for reactions of chemical compounds with hydroxyl radical are a key quantity used in evaluating the global warming potential of a substance. Experimental determination of these rate constants is essential, but it can also be difficult and time-consuming to produce. High-level quantum chemistry predictions of the rate constant can suffer from the same issues. Therefore, it is valuable to devise estimation schemes that can give reasonable results on a variety of chemical compounds. In this article, the construction and training of an artificial neural network (ANN) for the prediction of rate constants at 298 K for reactions of hydroxyl radical with a diverse set of molecules is described. Input to the ANN consists of counts of the chemical bonds and bends present in the target molecule. The ANN is trained using 792 (•)OH reaction rate constants taken from the NIST Chemical Kinetics Database. The mean unsigned percent error (MUPE) for the training set is 12%, and the MUPE of the testing set is 51%. It is shown that the present methodology yields rate constants of reasonable accuracy for a diverse set of inputs. The results are compared to high-quality literature values and to another estimation scheme. This ANN methodology is expected to be of use in a wide range of applications for which (•)OH reaction rate constants are required. The model uses only information that can be gathered from a 2D representation of the molecule, making the present approach particularly appealing, especially for screening applications.

[Research advances on regulating soil nitrogen loss by the type of nitrogen fertilizer and its application strategy.

PubMed

Zhou, Wei; Lyu, Teng Fei; Yang, Zhi Ping; Sun, Hong; Yang, Liang Jie; Chen, Yong; Ren, Wan Jun

2016-09-01

Unreasonable application of nitrogen fertilizer to cropland decreases nitrogen use efficiency of crop. A large amount of nitrogen loss to environment through runoff, leaching, ammonia volati-lization, nitrification-denitrification, etc., causes water and atmospheric pollution, poses serious environmental problems and threatens human health. The type of nitrogen fertilizer and its application rate, time, and method have significant effects on nitrogen loss. The primary reason for nitrogen loss is attributed to the supersaturated soil nitrogen concentration. Making full use of environmental nitrogen sources, reducing the application rate of chemical nitrogen fertilizers, applying deep placement fertilizing method, and applying organic fertilizers with chemical nitrogen fertilizers, are effective practices for reducing nitrogen loss and improving nitrogen use efficiency. It is suggested that deve-loping new high efficiency nitrogen fertilizers, enhancing nitrogen management, and strengthening the monitoring and use of environmental nitrogen sources are the powerful tools to decrease nitrogen application rate and increase efficiency of cropland.

Hierarchical Nitrogen-Doped Graphene/Carbon Nanotube Composite Cathode for Lithium-Oxygen Batteries.

PubMed

Shu, Chaozhu; Li, Bo; Zhang, Bingsen; Su, Dangsheng

2015-12-07

The lithium-oxygen (Li-O2 ) battery is a very appealing candidate for advanced high energy applications owing to its exceptionally high specific energy. However, its poor energy efficiency, rate capability, and cyclability remain key barriers to its practical application. In this work, using a rationally designed cathode based on a bimodal mesoporous nitrogen-doped graphene/carbon nanotube (NGC) composite, we have developed a Li-O2 battery demonstrating enhanced round-trip efficiency (ca. 85 %) and excellent cyclability over 400 cycles under a high current rate of 500 mA g(-1) . The excellent cyclability and rate capability are attributed to improved stability of the aggressive LiO2 intermediate on the nitrogen-doped carbon surface in addition to the favorable hierarchical architecture of NGC. These results demonstrate a valuable research direction to achieve highly stable and reversible Li-O2 batteries through tuning the surface chemistry of the cathode in addition to finding a stable electrolyte solvent. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heating-Rate-Triggered Carbon-Nanotube-based 3-Dimensional Conducting Networks for a Highly Sensitive Noncontact Sensing Device

NASA Astrophysics Data System (ADS)

Tai, Yanlong; Lubineau, Gilles

2016-01-01

Recently, flexible and transparent conductive films (TCFs) are drawing more attention for their central role in future applications of flexible electronics. Here, we report the controllable fabrication of TCFs for moisture-sensing applications based on heating-rate-triggered, 3-dimensional porous conducting networks through drop casting lithography of single-walled carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) ink. How ink formula and baking conditions influence the self-assembled microstructure of the TCFs is discussed. The sensor presents high-performance properties, including a reasonable sheet resistance (2.1 kohm/sq), a high visible-range transmittance (>69%, PET = 90%), and good stability when subjected to cyclic loading (>1000 cycles, better than indium tin oxide film) during processing, when formulation parameters are well optimized (weight ratio of SWCNT to PEDOT:PSS: 1:0.5, SWCNT concentration: 0.3 mg/ml, and heating rate: 36 °C/minute). Moreover, the benefits of these kinds of TCFs were verified through a fully transparent, highly sensitive, rapid response, noncontact moisture-sensing device (5 × 5 sensing pixels).

Performance of Wide Operating Temperature Range Electrolytes in Quallion Prototype Li-Ion Cells

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Tomcsi, M. R.; Nagata, M.; Visco, V.; Tsukamoto, H.

2010-01-01

For a number of applications, there is a continued interest in the development of rechargeable lithium-based batteries that can effectively operate over a wide temperature range (i.e., -40 to +70 deg C). These applications include powering future planetary rovers for NASA, enabling the next generation of automotive batteries for DOE, and supporting many DOD applications. Li-ion technology has been demonstrated to have good performance over a reasonably wide temperature range with many systems; however, there is still a desire to improve the low temperature rate capacity as well as the high temperature resilience. In the current study, we would like to present recent results obtained with prototype Li-Ion cells (manufactured by Quallion, LLC) which include various wide operating temperature range electrolytes developed by both JPL and Quallion. To demonstrate the viability of the technology, a number of performance tests were carried out, including: (a) discharge rate characterization over a wide temperature range (down to -60 deg C) using various rates (up to 20C rates), (b) discharge rate characterization at low temperatures with low temperature charging, (c) variable temperature cycling over a wide temperature range (-40 to +70 deg C), and (d) cycling at high temperature (50 deg C). As will be discussed, impressive rate capability was observed at low temperatures with many systems, as well as good resilience to high temperature cycling. To augment the performance testing on the prototype cells, a number of experimental three electrodes cells were fabricated (including Li reference electrodes) to allow the determination of the lithium kinetics of the respective electrodes and interfacial properties as a function of temperatures.

Does nitrogen fertilizer application rate to corn affect nitrous oxide emissions from the rotated soybean crop?

PubMed

Iqbal, Javed; Mitchell, David C; Barker, Daniel W; Miguez, Fernando; Sawyer, John E; Pantoja, Jose; Castellano, Michael J

2015-05-01

Little information exists on the potential for N fertilizer application to corn ( L.) to affect NO emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects NO emissions during subsequent crops in rotation, we measured NO emissions for 3 yr (2011-2013) in an Iowa, corn-soybean [ (L.) Merr.] rotation with three N fertilizer rates applied to corn (0 kg N ha, the recommended rate of 135 kg N ha, and a high rate of 225 kg N ha); soybean received no N fertilizer. We further investigated the potential for a winter cereal rye ( L.) cover crop to interact with N fertilizer rate to affect NO emissions from both crops. The cover crop did not consistently affect NO emissions. Across all years and irrespective of cover crop, N fertilizer application above the recommended rate resulted in a 16% increase in mean NO flux rate during the corn phase of the rotation. In 2 of the 3 yr, N fertilizer application to corn (0-225 kg N ha) did not affect mean NO flux rates from the subsequent unfertilized soybean crop. However, in 1 yr after a drought, mean NO flux rates from the soybean crops that received 135 and 225 kg N ha N application in the corn year were 35 and 70% higher than those from the soybean crop that received no N application in the corn year. Our results are consistent with previous studies demonstrating that cover crop effects on NO emissions are not easily generalizable. When N fertilizer affects NO emissions during a subsequent unfertilized crop, it will be important to determine if total fertilizer-induced NO emissions are altered or only spread across a greater period of time. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Image-Guided High-Dose Rate Brachytherapy in Cervix Carcinoma Using Balloon Catheter and Belt Immobilization System.

PubMed

Fan, Qiyong; Yeung, Anamaria R; Amdur, Robert; Helmig, Richard; Park, Justin; Li, Jonathan; Kahler, Darren; Liu, Chihray; Lu, Bo

2017-06-01

The efficacy of image-guided high-dose rate brachytherapy for cervical cancer is limited by the ineffective rectal sparing devices available commercially and the potential applicator movement. We developed a novel device using a balloon catheter and a belt immobilization system, serving for rectal dose reduction and applicator immobilization purposes, respectively. The balloon catheter is constructed by gluing a short inflatable tube to a long regular open-end catheter. Contrast agent (10) cm 3 is injected into the inflatable end, which is affixed to the tandem and ring applicator, to displace the posterior vaginal wall. The belt immobilization system consists of a specially designed bracket that can hold and fix itself to the applicator, a diaper-like Velcro fastener package used for connecting the patient's pelvis to the bracket, and a buckle that holds the fasteners to stabilize the whole system. The treatment data for 21 patients with cervical cancer using both balloon catheter and belt immobilization system were retrospectively analyzed. Computed tomography and magnetic resonance images, acquired about 30 minutes apart, were registered to evaluate the effectiveness of the immobilization system. In comparison with a virtual rectal blade, the balloon decreased the rectal point dose by 34% ± 4.2% (from 276 ± 57 to 182 ± 38 cGy), corresponding to an extra sparing distance of 7.9 ± 1.1 mm. The maximum sparing distance variation per patient is 1.4 ± 0.6 mm, indicating the high interfractional reproducibility for rectum sparing. With the immobilization system, the mean translational and rotational displacements of the applicator set are <3 mm and <1.5°, respectively, in all directions. The rectal balloon provides significant dose reduction to the rectum and it may potentially minimize patient discomfort. The immobilization system permits almost no movement of the applicator during treatment. This work has the potential to be promoted as a standardized solution for high-dose rate treatment of cervical cancer.

Arc-Ed Curriculum: Applicability for Severely Handicapped Pupils.

ERIC Educational Resources Information Center

Chaffin, Jerry D.

1982-01-01

The Arc Ed Curriculum uses video game formats to teach math and language arts content. Four motivational features (feedback, improvement, high response rates, and unlimited ceiling on performance along with adapted content could make the system applicable for use with severely handicapped learners. (CL)

The Bebig Valencia-type skin applicators: Dosimetric study and implementation of a dosimetric hybrid technique.

PubMed

Anagnostopoulos, Georgios; Andrássy, Michael; Baltas, Dimos

To determine the relative dose rate distribution in water for the Bebig 20 mm and 30 mm skin applicators and report results in a form suitable for potential clinical use. Results for both skin applicators are also provided in the form of a hybrid Task Group 43 (TG-43) dosimetry technique. Furthermore, the radiation leakage around both skin applicators from the radiation protection point of view and the impact of the geometrical source position uncertainties are studied and reported. Monte Carlo simulations were performed using the MCNP 6.1 general purpose code, which was benchmarked against published dosimetry data for the Bebig Ir2.A85-2 high-dose-rate iridium-192 source, as well as the dosimetry data for the two Elekta skin applicators. Both Bebig skin applicators were modeled, and the dose rate distributions in a water phantom were calculated. The dosimetric quantities derived according to a hybrid TG-43 dosimetry technique are provided with their corresponding uncertainty values. The air kerma rate in air was simulated in the vicinity of each skin applicator to assess the radiation leakage. Results from the Monte Carlo simulations of both skin applicators are presented in the form of figures and relative dose rate tables, and additionally with the aid of the quantities defined in the hybrid TG-43 dosimetry technique and their corresponding uncertainty values. Their output factors, flatness, and penumbra values were found comparable to the Elekta skin applicators. The radiation shielding was evaluated to be adequate. The effect of potential uncertainties in source positioning on dosimetry should be investigated as part of applicator commissioning. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Multiphase High-Frequency Isolated DC-DC Converter for Industrial Applications

NASA Astrophysics Data System (ADS)

Maurya, Rakesh; Srivastava, S. P.; Agarwal, Pramod

2014-01-01

Industrial applications such as welding, plasma cutting, and surface hardening require a large DC current at low voltage. In such applications, the rating of power supply varies from few kilowatts to hundreds of kilowatts. The power supply employs in such applications particularly in arc welding process is expected to operate from open-circuit (no-load) to short-circuit (when the electrode sticks to the workpiece for a short span of time) quickly. In this paper, high-frequency isolated multiphase DC-DC converter is proposed which is well suited for aforementioned applications. Based on mathematical analysis, a simulation study with 5 kW, 5 V/1,000 A proposed model is carried out using Simulink block set and Sim Power System tool box and its performances are evaluated under symmetrical control methods. To verify the simulation results, scaled prototype model of rating 1.5 V/100 A is developed and tested with aforementioned control method under different operating conditions. In comparison with conventional welding power supply employed in many industries, the performance of proposed converter is improved significantly in terms of size and weight, efficiency and dynamic response.

The application of compressed sensing to long-term acoustic emission-based structural health monitoring

NASA Astrophysics Data System (ADS)

Cattaneo, Alessandro; Park, Gyuhae; Farrar, Charles; Mascareñas, David

2012-04-01

The acoustic emission (AE) phenomena generated by a rapid release in the internal stress of a material represent a promising technique for structural health monitoring (SHM) applications. AE events typically result in a discrete number of short-time, transient signals. The challenge associated with capturing these events using classical techniques is that very high sampling rates must be used over extended periods of time. The result is that a very large amount of data is collected to capture a phenomenon that rarely occurs. Furthermore, the high energy consumption associated with the required high sampling rates makes the implementation of high-endurance, low-power, embedded AE sensor nodes difficult to achieve. The relatively rare occurrence of AE events over long time scales implies that these measurements are inherently sparse in the spike domain. The sparse nature of AE measurements makes them an attractive candidate for the application of compressed sampling techniques. Collecting compressed measurements of sparse AE signals will relax the requirements on the sampling rate and memory demands. The focus of this work is to investigate the suitability of compressed sensing techniques for AE-based SHM. The work explores estimating AE signal statistics in the compressed domain for low-power classification applications. In the event compressed classification finds an event of interest, ι1 norm minimization will be used to reconstruct the measurement for further analysis. The impact of structured noise on compressive measurements is specifically addressed. The suitability of a particular algorithm, called Justice Pursuit, to increase robustness to a small amount of arbitrary measurement corruption is investigated.

Investigation of the shear thinning behavior of epoxy resins for utilization in vibration assisted liquid composite molding processes

NASA Astrophysics Data System (ADS)

Meier, R.; Kirdar, C.; Rudolph, N.; Zaremba, S.; Drechsler, K.

2014-05-01

Efficient production and consumption of energy are of greatest importance for contemporary industries and their products. This has led to an increasing application of lightweight materials in general and of Carbon Fiber Reinforced Plastics (CFRP) in particular. However, broader application of CFRP is often limited by high costs and manual labor production processes. These constraints are addressed by Liquid Composite Molding (LCM) processes. In LCM a dry fibrous preform is placed into a cavity and infiltrated mostly by thermoset resins; epoxy resins are wide spread in CFRP applications. One crucial parameter for a fast mold filling is the viscosity of the resin, which is affected by the applied shear rates as well as temperature and curing time. The work presented focuses on the characterization of the shear thinning behavior of epoxy resins. Furthermore, the correlation with the conditions in vibration assisted LCM processes, where additional shear rates are created during manufacture, is discussed. Higher shear rates result from high frequencies and/or high amplitudes of the vibration motions which are created by a vibration engine mounted on the mold. In rheological investigations the shear thinning behavior of a representative epoxy resin is studied by means of rotational and oscillatory experiments. Moreover, possible effects of shear rates on the chemical curing reaction are studied. Here, the time for gelation is measured for different levels of shear rates in a pre-shearing phase. Based on the rheological studies, the beneficial effect of vibration assistance in LCM processes with respect to mold filling can further be predicted and utilized.

Pulse shape discrimination of Cs2LiYCl6:Ce3+ detectors at high count rate based on triangular and trapezoidal filters

NASA Astrophysics Data System (ADS)

Wen, Xianfei; Enqvist, Andreas

2017-09-01

Cs2LiYCl6:Ce3+ (CLYC) detectors have demonstrated the capability to simultaneously detect γ-rays and thermal and fast neutrons with medium energy resolution, reasonable detection efficiency, and substantially high pulse shape discrimination performance. A disadvantage of CLYC detectors is the long scintillation decay times, which causes pulse pile-up at moderate input count rate. Pulse processing algorithms were developed based on triangular and trapezoidal filters to discriminate between neutrons and γ-rays at high count rate. The algorithms were first tested using low-rate data. They exhibit a pulse-shape discrimination performance comparable to that of the charge comparison method, at low rate. Then, they were evaluated at high count rate. Neutrons and γ-rays were adequately identified with high throughput at rates of up to 375 kcps. The algorithm developed using the triangular filter exhibits discrimination capability marginally higher than that of the trapezoidal filter based algorithm irrespective of low or high rate. The algorithms exhibit low computational complexity and are executable on an FPGA in real-time. They are also suitable for application to other radiation detectors whose pulses are piled-up at high rate owing to long scintillation decay times.

High Pulse Repetition Rate, Eye Safe, Visible Wavelength Lidar Systems: Design, Results and Potential

NASA Technical Reports Server (NTRS)

Spinhirne, James; Berkoff, Timothy; Welton, Elsworth; Campbell, James; OCStarr, David (Technical Monitor)

2002-01-01

In 1993 the first of the eye safe visible wavelength lidar systems known now as Micro Pulse Lidar (MPL) became operational. Since that time there have been several dozen of these systems produced and applied for full time profiling of atmospheric cloud and aerosol structure. There is currently an observational network of MPL sites to support global climate research. In the course of application of these instruments there have been significant improvements in understanding, design and performance of the systems. There are addition potential and applications beyond current practice for the high repetition rate, eye safe designs. The MPL network and the current capability, design and future potential of MPL systems are described.

Application of millisecond pulsed laser for thermal fatigue property evaluation

NASA Astrophysics Data System (ADS)

Pan, Sining; Yu, Gang; Li, Shaoxia; He, Xiuli; Xia, Chunyang; Ning, Weijian; Zheng, Caiyun

2018-02-01

An approach based on millisecond pulsed laser is proposed for thermal fatigue property evaluation in this paper. Cyclic thermal stresses and strains within millisecond interval are induced by complex and transient temperature gradients with pulsed laser heating. The influence of laser parameters on surface temperature is studied. The combination of low pulse repetition rate and high pulse energy produces small temperature oscillation, while high pulse repetition rate and low pulse energy introduces large temperature shock. The possibility of application is confirmed by two thermal fatigue tests of compacted graphite iron with different laser controlled modes. The developed approach is able to fulfill the preset temperature cycles and simulate thermal fatigue failure of engine components.

Sci-Thur PM – Brachytherapy 06: 3D Printed Surface Applicators for High Dose Rate Brachytherapy

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

Clarke, Scott; Yewondwossen, Mammo; Robar, James

Purpose: The purpose of this work is to develop a new applicator for administering high dose rate (HDR) brachytherapy using 3D printing technology. Primary advantages of using a 3D printed applicator will be to offer a more streamlined approach for therapists and patients while achieving better conformity, reproducibility, and patient specific applicators. Methods: A phantom study was conducted to measure the effectiveness of a 3D printed surface applicator by analyzing tumours on three locations of the body: the foot, nose, and scalp. The applicator was designed using Eclipse and further modified using Blender to create the catheter tunnels before beingmore » printed on a Lulzbot Taz 5 3D printer. A radiation plan was made using Oncentra Brachytherapy for a control treatment option using Freiburg Flaps and one with the novel method of a 3D printed applicator. A comparative analysis was made using D90, D100, V100, V150, and V200 Results: The 3D printed applicator showed comparable dose coverage with significant improvements on highly irregular surfaces when analyzed against a plan made using Freiburg Flaps. Although both plans exhibited complete tumour coverage, the 3D applicator showed improvements in D90 and V150 and the 3D applicator had a dose homogeneity index (DHI) of 0.99 compared to a DHI of 0.97 for the control. Therapist prep time also dropped significantly due to the lack of need for a thermoplastic mesh. Conclusions: 3D printed applicators for treatment of superficial sites proved to offer more patient convenience, less prep time, better conformity and tighter margins.« less

Few-Layer MXenes Delaminated via High-Energy Mechanical Milling for Enhanced Sodium-Ion Batteries Performance.

PubMed

Wu, Yuting; Nie, Ping; Wang, Jiang; Dou, Hui; Zhang, Xiaogang

2017-11-15

The global availability of sodium makes the exploration of superior sodium-ion batteries attractive for energy storage application. MXenes, as one of the most promising anodes for sodium-ion batteries, have been reported to have many advantages, such as high electronic conductivity and a hydrophilic surface. However, the compact multilayer structure and deficient delamination significantly inhibits their application, requiring high energy and showing decreased storage capacity and poor rate capabilities. Few-layer MXene has been proved to benefit superior electrochemical properties with a better ionic conductivity and two-dimensional layer structure. Herein, we report scale delamination of few-layer MXene nanosheets as anodes for sodium-ion batteries, which are prepared via an organic solvent assist high-energy mechanical-milling method. This approach efficiently prevents the oxidation of MXene and produces few-layer nanosheets structure, facilitating fast electron transport and Na + diffusion. Electrochemical tests demonstrate that the few-layer MXenes show high specific capacity, excellent cycle stability, and good rate performance. Specifically, few-layer MXene nanosheets deliver a high reversible capacity of 267 mA h g -1 at a current density of 0.1 A g -1 . After cycling 1500 cycles at a high rate of 1 A g -1 , a reversible capacity of 76 mA h g -1 could be maintained.

Application of the time-temperature superposition principle to the mechanical characterization of elastomeric adhesives for crash simulation purposes

NASA Astrophysics Data System (ADS)

Rauh, A.; Hinterhölzl, R.; Drechsler, K.

2012-05-01

In the automotive industry, finite element simulation is widely used to ensure crashworthiness. Mechanical material data over wide strain rate and temperature ranges are required as a basis. This work proposes a method reducing the cost of mechanical material characterization by using the time-temperature superposition principle on elastomeric adhesives. The method is based on the time and temperature interdependence which is characteristic for mechanical properties of polymers. Based on the assumption that polymers behave similarly at high strain rates and at low temperatures, a temperature-dominated test program is suggested, which can be used to deduce strain rate dependent material behavior at different reference temperatures. The temperature shift factor is found by means of dynamic mechanical analysis according to the WLF-equation, named after Williams, Landel and Ferry. The principle is applied to the viscoelastic properties as well as to the failure properties of the polymer. The applicability is validated with high strain rate tests.

Elucidating the impact of micro-scale heterogeneous bacterial distribution on biodegradation

NASA Astrophysics Data System (ADS)

Schmidt, Susanne I.; Kreft, Jan-Ulrich; Mackay, Rae; Picioreanu, Cristian; Thullner, Martin

2018-06-01

Groundwater microorganisms hardly ever cover the solid matrix uniformly-instead they form micro-scale colonies. To which extent such colony formation limits the bioavailability and biodegradation of a substrate is poorly understood. We used a high-resolution numerical model of a single pore channel inhabited by bacterial colonies to simulate the transport and biodegradation of organic substrates. These high-resolution 2D simulation results were compared to 1D simulations that were based on effective rate laws for bioavailability-limited biodegradation. We (i) quantified the observed bioavailability limitations and (ii) evaluated the applicability of previously established effective rate concepts if microorganisms are heterogeneously distributed. Effective bioavailability reductions of up to more than one order of magnitude were observed, showing that the micro-scale aggregation of bacterial cells into colonies can severely restrict the bioavailability of a substrate and reduce in situ degradation rates. Effective rate laws proved applicable for upscaling when using the introduced effective colony sizes.

Land spreading of sewage sludge in forest plantations: effects on the growth of the duckweed Lemna minor and trace metal bioaccumulation in the snail Cantareus aspersus.

PubMed

Mohamed, Bourioug; Frédéric, Gimbert; Laurence, Alaoui-Sehmer; Pierre-Marie, Badot; Badr, Alaoui-Sossé; Lotfi, Aleya

2016-05-01

Wastewater plants generated annually millions of tons of sewage sludge (SS). Large amounts of this organic residue are spread on agricultural lands as a fertilizer, although it is viewed as a major potential source of contamination, presenting a danger to the terrestrial and aquatic environments. This study was undertaken to evaluate the impact of this practice on the duckweed Lemna minor and the snail Cantareus aspersus. Sludge was applied to soil either at six different loading rates equal to 0, 0.4, 3, 10, 30, and 60 tons dry matter (DM) ha(-1) for L. minor test or at three rates equal to 0, 30, and 60 tons DM ha(-1) for C. aspersus test. At the highest rate of SS application (60 tons DM ha(-1)), the eluates showed that an increase in pH (6.1) resulted in a decrease in Al levels. Thus, the high stimulation of L. minor growth observed after this high rate of SS application can be explained by (i) a reduction in Al toxicity after precipitation and (ii) macro- and micronutrient enrichment. At a rate of SS application of only 30 tons DM ha(-1), growth appeared to be slightly significant (p < 0.05), in spite of the significant increase in essential mineral elements. However, it is very difficult to discriminate between Al toxicity and pH effects. For the test with C. aspersus, the snail biomass was not affected by sludge application over the exposure period. Mortality was extremely low, with a rate of less than 4 % at the last sampling date. Yet, Cu, Pb, and Cd accumulated significantly in the soft body of snails exposed to SS application, suggesting that the amount of metals excreted is lower than that absorbed. In contrast, Zn levels remain constant, inferring that absorption and elimination of Zn are balanced at the beginning of the experiment.

Evaluation of components, subsystems, and networks for high rate, high frequency space communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Ivancic, William D.; Zuzek, John E.

1991-01-01

The development of new space communications technologies by NASA has included both commercial applications and space science requirements. At NASA's Lewis Research Center, methods and facilities have been developed for evaluating these new technologies in the laboratory. NASA's Systems Integration, Test and Evaluation (SITE) Space Communication System Simulator is a hardware-based laboratory simulator for evaluating space communications technologies at the component, subsystem, system, and network level, geared toward high frequency, high data rate systems. The SITE facility is well-suited for evaluation of the new technologies required for the Space Exploration Initiative (SEI) and advanced commercial systems. This paper describes the technology developments and evaluation requirements for current and planned commercial and space science programs. Also examined are the capabilities of SITE, the past, present, and planned future configurations of the SITE facility, and applications of SITE to evaluation of SEI technology.

Beta Testing a Novel Smartphone Application to Improve Medication Adherence.

PubMed

Sarzynski, Erin; Decker, Brian; Thul, Aaron; Weismantel, David; Melaragni, Ronald; Cholakis, Elizabeth; Tewari, Megha; Beckholt, Kristy; Zaroukian, Michael; Kennedy, Angie C; Given, Charles

2017-04-01

We developed and beta-tested a patient-centered medication management application, PresRx optical character recognition (OCR), a mobile health (m-health) tool that auto-populates drug name and dosing instructions directly from patients' medication labels by OCR. We employed a single-subject design study to evaluate PresRx OCR for three outcomes: (1) accuracy of auto-populated medication dosing instructions, (2) acceptability of the user interface, and (3) patients' adherence to chronic medications. Eight patients beta-tested PresRx OCR. Five patients used the software for ≥6 months, and four completed exit interviews (n = 4 completers). At baseline, patients used 3.4 chronic prescription medications and exhibited moderate-to-high adherence rates. Accuracy of auto-populated information by OCR was 95% for drug name, 98% for dose, and 96% for frequency. Study completers rated PresRx OCR 74 on the System Usability Scale, where scores ≥70 indicate an acceptable user interface (scale 0-100). Adherence rates measured by PresRx OCR were high during the first month of app use (93%), but waned midway through the 6-month testing period (78%). Compared with pharmacy fill rates, PresRx OCR underestimated adherence among completers by 3%, while it overestimated adherence among noncompleters by 8%. Results suggest smartphone applications supporting medication management are feasible and accurately assess adherence compared with objective measures. Future efforts to improve medication-taking behavior using m-health tools should target specific patient populations and leverage common application programming interfaces to promote generalizability. Our medication management application PresRx OCR is innovative, acceptable for patient use, and accurately tracks medication adherence.

Single Longitudinal Mode, High Repetition Rate, Q-switched Ho:YLF Laser for Remote Sensing

NASA Technical Reports Server (NTRS)

Bai, Yingxin; Yu, Jirong; Petzar, Paul; Petros, M.; Chen, Songsheng; Trieu, Bo; Lee, Nyung; Singh, U.

2009-01-01

Ho:YLF/LuLiF lasers have specific applications for remote sensing such as wind-speed measurement and carbon dioxide (CO2) concentration measurement in the atmosphere because the operating wavelength (around 2 m) is located in the eye-safe range and can be tuned to the characteristic lines of CO2 absorption and there is strong backward scattering signal from aerosol (Mie scattering). Experimentally, a diode pumped Ho:Tm:YLF laser has been successfully used as the transmitter of coherent differential absorption lidar for the measurement of with a repetition rate of 5 Hz and pulse energy of 75 mJ [1]. For highly precise CO2 measurements with coherent detection technique, a laser with high repetition rate is required to averaging out the speckle effect [2]. In addition, laser efficiency is critically important for the air/space borne lidar applications, because of the limited power supply. A diode pumped Ho:Tm:YLF laser is difficult to efficiently operate in high repetition rate due to the large heat loading and up-conversion. However, a Tm:fiber laser pumped Ho:YLF laser with low heat loading can be operated at high repetition rates efficiently [3]. No matter whether wind-speed or carbon dioxide (CO2) concentration measurement is the goal, a Ho:YLF/LuLiF laser as the transmitter should operate in a single longitudinal mode. Injection seeding is a valid technique for a Q-switched laser to obtain single longitudinal mode operation. In this paper, we will report the new results for a single longitudinal mode, high repetition rate, Q-switched Ho:YLF laser. In order to avoid spectral hole burning and make injection seeding easier, a four mirror ring cavity is designed for single longitudinal mode, high repetition rate Q-switched Ho:YLF laser. The ramp-fire technique is chosen for injection seeding.

High-speed optical links for UAV applications

NASA Astrophysics Data System (ADS)

Chen, C.; Grier, A.; Malfa, M.; Booen, E.; Harding, H.; Xia, C.; Hunwardsen, M.; Demers, J.; Kudinov, K.; Mak, G.; Smith, B.; Sahasrabudhe, A.; Patawaran, F.; Wang, T.; Wang, A.; Zhao, C.; Leang, D.; Gin, J.; Lewis, M.; Nguyen, D.; Quirk, K.

2017-02-01

High speed optical backbone links between a fleet of UAVs is an integral part of the Facebook connectivity architecture. To support the architecture, the optical terminals need to provide high throughput rates (in excess of tens of Gbps) while achieving low weight and power consumption. The initial effort is to develop and demonstrate an optical terminal capable of meeting the data rate requirements and demonstrate its functions for both air-air and air-ground engagements. This paper is a summary of the effort to date.

Large Area Field of View for Fast Temporal Resolution Astronomy

NASA Astrophysics Data System (ADS)

Covarrubias, Ricardo A.

2018-01-01

Scientific CMOS (sCMOS) technology is especially relevant for high temporal resolution astronomy combining high resolution, large field of view with very fast frame rates, without sacrificing ultra-low noise performance. Solar Astronomy, Near Earth Object detections, Space Debris Tracking, Transient Observations or Wavefront Sensing are among the many applications this technology can be utilized. Andor Technology is currently developing the next-generation, very large area sCMOS camera with an extremely low noise, rapid frame rates, high resolution and wide dynamic range.

High-precision cutting of polyimide film using femtosecond laser for the application in flexible electronics

NASA Astrophysics Data System (ADS)

Ganin, D. V.; Lapshin, K. E.; Obidin, A. Z.; Vartapetov, S. K.

2018-01-01

The experimental results of cutting a polyimide film on the optical glass substrate by means of femtosecond lasers are given. Two modes of laser cutting of this film without damages to a glass base are determined. The first is the photo graphitization using a high repetition rate femtosecond laser. The second is ablative, under the effect of femtosecond laser pulses with high energy and low repetition rate. Cutting of semiconductor chips formed on the polyimide film surface is successfully demonstrated.

High data rate coding for the space station telemetry links.

NASA Technical Reports Server (NTRS)

Lumb, D. R.; Viterbi, A. J.

1971-01-01

Coding systems for high data rates were examined from the standpoint of potential application in space-station telemetry links. Approaches considered included convolutional codes with sequential, Viterbi, and cascaded-Viterbi decoding. It was concluded that a high-speed (40 Mbps) sequential decoding system best satisfies the requirements for the assumed growth potential and specified constraints. Trade-off studies leading to this conclusion are viewed, and some sequential (Fano) algorithm improvements are discussed, together with real-time simulation results.

Laser Hot Wire Process: A Novel Process for Near-Net Shape Fabrication for High-Throughput Applications

NASA Astrophysics Data System (ADS)

Kottman, Michael; Zhang, Shenjia; McGuffin-Cawley, James; Denney, Paul; Narayanan, Badri K.

2015-03-01

The laser hot wire process has gained considerable interest for additive manufacturing applications, leveraging its high deposition rate, low dilution, thermal stability, and general metallurgical control including the ability to introduce and preserve desired meta-stable phases. Recent advancements in closed-loop process control and laser technology have increased productivity, process stability, and control of deposit metallurgy. The laser hot wire process has shown success in several applications: repairing and rejuvenating casting dies, depositing a variety of alloys including abrasion wear-resistant overlays with solid and tubular wires, and producing low-dilution (<5%) nickel alloy overlays for corrosion applications. The feasibility of fabricating titanium buildups is being assessed for aerospace applications.

High-voltage, high-current, solid-state closing switch

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

Focia, Ronald Jeffrey

2017-08-22

A high-voltage, high-current, solid-state closing switch uses a field-effect transistor (e.g., a MOSFET) to trigger a high-voltage stack of thyristors. The switch can have a high hold-off voltage, high current carrying capacity, and high time-rate-of-change of current, di/dt. The fast closing switch can be used in pulsed power applications.

Holographic optical disc

NASA Astrophysics Data System (ADS)

Zhou, Gan; An, Xin; Pu, Allen; Psaltis, Demetri; Mok, Fai H.

1999-11-01

The holographic disc is a high capacity, disk-based data storage device that can provide the performance for next generation mass data storage needs. With a projected capacity approaching 1 terabit on a single 12 cm platter, the holographic disc has the potential to become a highly efficient storage hardware for data warehousing applications. The high readout rate of holographic disc makes it especially suitable for generating multiple, high bandwidth data streams such as required for network server computers. Multimedia applications such as interactive video and HDTV can also potentially benefit from the high capacity and fast data access of holographic memory.

Materials, devices, techniques, and applications for Z-plane focal plane array technology II; Proceedings of the Meeting, San Diego, CA, July 12, 13, 1990

NASA Astrophysics Data System (ADS)

Carson, John C.

1990-11-01

Various papers on materials, devices, techniques, and applications for X-plane focal plane array technology are presented. Individual topics addressed include: application of Z-plane technology to the remote sensing of the earth from GEO, applications of smart neuromorphic focal planes, image-processing of Z-plane technology, neural network Z-plane implementation with very high interconnection rates, using a small IR surveillance satellite for tactical applications, establishing requirements for homing applications, Z-plane technology. Also discussed are: on-array spike suppression signal processing, algorithms for on-focal-plane gamma circumvention and time-delay integration, current HYMOSS Z-technology, packaging of electrons for on- and off-FPA signal processing, space/performance qualification of tape automated bonded devices, automation in tape automated bonding, high-speed/high-volume radiometric testing of Z-technology focal planes, 128-layer HYMOSS-module fabrication issues, automation of IRFPA production processes.

Decreasing Nitrogen Fertilizer Input Had Little Effect on Microbial Communities in Three Types of Soils

PubMed Central

Yu, Hailing; Gao, Qiang; Shao, Zeqiang; Ying, Anning; Sun, Yuyang; Liu, Jingwei; Mao, Wei; Zhang, Bin

2016-01-01

In this study, we examined the influence of different nitrogen (N) application rates (0, 168, 240, 270 and 312 kg N ha-1) on soil properties, maize (Zea mays L.) yields and microbial communities of three types of soils (clay, alluvial and sandy soils). Phospholipid fatty acid analysis was used to characterize soil microbial communities. Results indicated that N fertilization significantly decreased microbial biomass in both clay and sandy soils regardless of application rate. These decreases were more likely a result of soil pH decreases induced by N fertilization, especially in the sandy soils. This is supported by structural equation modeling and redundancy analysis results. Nitrogen fertilization also led to significant changes in soil microbial community composition. However, the change differences were gradually dismissed with increase in N application rate. We also observed that N fertilization increased maize yields to the same level regardless of application rate. This suggests that farmers could apply N fertilizers at a lower rate (i.e. 168 kg N ha-1), which could achieve high maize yield on one hand while maintain soil microbial functions on the other hand. PMID:26992097

Experimental investigation of anisotropy evolution of AZ31 magnesium alloy sheets under tensile loading

NASA Astrophysics Data System (ADS)

Tari, D. Ghaffari; Worswick, M. J.

2011-05-01

Increasing demand for lighter final products has created new opportunities for the application of new light weight materials. Due to high strength to density ratio and good magnetic resistance properties, magnesium alloys are good candidates to replace steel and aluminum for same application. However, limited numbers of active slip deformation mechanisms, result in a decreased formability at room temperature. Furthermore, wrought magnesium alloys have an initial crystallographic texture, remained from the prior rolling operations, which makes them highly anisotropic. In this paper, tensile tests are performed at room temperature and 200° C at different strain rates and orientations relative to the rolling direction, including rolling, 30°, 45°, 60° and transverse orientation. The strain rates adopted for these experiments varied from 0.001 to 1.0. The testing results show the effect of temperature on the strain rate sensitivity of AZ31 sheets. The extent of deformation is continuously recorded using two separate high temperature extensometers. The results of testing show an increase in the r-values with the plastic deformation. The strain rate sensitivity of AZ31 increased as the temperature was elevated. At higher strain rates the measured r-values are larger and the slope of its evolution with the plastic strain is steeper.

Emphasis on High Power Lithium Ion Technology for Pulse-Load Operations: Terrestrial Developments Potential Benefits to Space Application

NASA Astrophysics Data System (ADS)

Fusalba, Florence; Chami, Marianne; Rey, Marlene; Moreau, Gilles; Reynier, Yvan; Azais, Philippe

2014-08-01

Currently Li-ion batteries are preferred to supply space missions owing to their large energy density. However, these batteries are designed for standard missions without high-power pulsed payloads, therefore for low C-rates profiles, and do not answer the needs of high- power space applications. More enhanced power sources compatible with extended thermal environment are therefore needed for some space applications like next generation launchers or radar satellites. It is believed that synergy between terrestrial and space sectors could foster the avoidance of multiple financing for the development of similar technologies and systems, as well as dual-use of facilities, providing some real applications for synergy. CEA experienced terrestrial requirements for Hybrid Electric Vehicle applications, start & stop, e-buses and other larger vehicles. In this frame, materials especially designed for high power needs, new cells conception and recently hybrid supercapacitors developments at CEA are discussed as potential solutions for space high power feature.

A semi-direct procedure using a local relaxation factor and its application to an internal flow problem

NASA Technical Reports Server (NTRS)

Chang, S. C.

1984-01-01

Generally, fast direct solvers are not directly applicable to a nonseparable elliptic partial differential equation. This limitation, however, is circumvented by a semi-direct procedure, i.e., an iterative procedure using fast direct solvers. An efficient semi-direct procedure which is easy to implement and applicable to a variety of boundary conditions is presented. The current procedure also possesses other highly desirable properties, i.e.: (1) the convergence rate does not decrease with an increase of grid cell aspect ratio, and (2) the convergence rate is estimated using the coefficients of the partial differential equation being solved.

High-speed digital signal normalization for feature identification

NASA Technical Reports Server (NTRS)

Ortiz, J. A.; Meredith, B. D.

1983-01-01

A design approach for high speed normalization of digital signals was developed. A reciprocal look up table technique is employed, where a digital value is mapped to its reciprocal via a high speed memory. This reciprocal is then multiplied with an input signal to obtain the normalized result. Normalization improves considerably the accuracy of certain feature identification algorithms. By using the concept of pipelining the multispectral sensor data processing rate is limited only by the speed of the multiplier. The breadboard system was found to operate at an execution rate of five million normalizations per second. This design features high precision, a reduced hardware complexity, high flexibility, and expandability which are very important considerations for spaceborne applications. It also accomplishes a high speed normalization rate essential for real time data processing.

A-Si Photoreceptors At The Threshold Of Industrial Application

NASA Astrophysics Data System (ADS)

Senske, W.; Marschall, N.

1986-03-01

A-Si has become an attractive alternative for conventional electrophotographic photoreceptors. A-Si photoreceptors have been prepared by other laboratories by plasma deposition with blocking and protection layers. These photoreceptors are highly photosensitive and show low fatigue. Using sputtering we have shown that this technique is capable of produc-ing films with high charge acceptance. The increase of the deposition rate is presently un-der intensive investigation. High rates can be achieved by a higher degree of silane decomposition or by magnetron sputtering together with a higher power level. Deposition rates of more than 20 pm/h have been obtained by both techniques.

Measurement of Outgassing Rates of Steels.

PubMed

Park, Chongdo; Kim, Se-Hyun; Ki, Sanghoon; Ha, Taekyun; Cho, Boklae

2016-12-13

Steels are commonly used materials in the fabrication of vacuum systems because of their good mechanical, corrosion, and vacuum properties. A variety of steels meet the criterion of low outgassing required for high or ultrahigh vacuum applications. However, a given material can present different outgassing rates depending on its manufacturing process or the various pretreatment processes involved during the fabrication. Thus, the measurement of outgassing rates is highly desirable for a specific vacuum application. For this reason, the rate-of-pressure rise (RoR) method is often used to measure the outgassing of hydrogen after bakeout. In this article, a detailed description of the design and execution of the experimental protocol involved in the RoR method is provided. The RoR method uses a spinning rotor gauge to minimize errors that stem from outgassing or the pumping action of a vacuum gauge. The outgassing rates of two ordinary steels (stainless steel and mild steel) were measured. The measurements were made before and after the heat pretreatment of the steels. The heat pretreatment of steels was performed to reduce the outgassing. Extremely low rates of outgassing (on the order of 10 - 11 Pa m 3 sec - 1 m - 2 ) can be routinely measured using relatively small samples.

High precision applications of the global positioning system

NASA Technical Reports Server (NTRS)

Lichten, Stephen M.

1991-01-01

The Global Positioning System (GPS) is a constellation of U.S. defense navigation satellites which can be used for military and civilian positioning applications. A wide variety of GPS scientific applications were identified and precise positioning capabilities with GPS were already demonstrated with data available from the present partial satellite constellation. Expected applications include: measurements of Earth crustal motion, particularly in seismically active regions; measurements of the Earth's rotation rate and pole orientation; high-precision Earth orbiter tracking; surveying; measurements of media propagation delays for calibration of deep space radiometric data in support of NASA planetary missions; determination of precise ground station coordinates; and precise time transfer worldwide.

High-Flux Solar Furnace Facility | Concentrating Solar Power | NREL

Science.gov Websites

High-Flux Solar Furnace Facility High-Flux Solar Furnace Facility NREL's High-Flux Solar Furnace (HFSF) is a 10-kW optical furnace for testing high-temperature processes or applications requiring high range of technologies with a diverse set of experimental requirements. The high heating rates create the

Development and application of a local linearization algorithm for the integration of quaternion rate equations in real-time flight simulation problems

NASA Technical Reports Server (NTRS)

Barker, L. E., Jr.; Bowles, R. L.; Williams, L. H.

1973-01-01

High angular rates encountered in real-time flight simulation problems may require a more stable and accurate integration method than the classical methods normally used. A study was made to develop a general local linearization procedure of integrating dynamic system equations when using a digital computer in real-time. The procedure is specifically applied to the integration of the quaternion rate equations. For this application, results are compared to a classical second-order method. The local linearization approach is shown to have desirable stability characteristics and gives significant improvement in accuracy over the classical second-order integration methods.

Zinc-oxygen battery development program

NASA Technical Reports Server (NTRS)

Bourland, Deborah S.

1991-01-01

The purpose of this Zinc-Oxygen development program is to incorporate the improved air/oxygen cathode and zinc anode technology developed in recent years into relatively large cells (150-200 amp/hr, 25-100 hour rate) and smaller high rate cells (9-12 amp/hr, 3-12 hour rate). Existing commercial cells manufactured by Duracell and Rayovac are currently being utilized on the Space Shuttle Orbiter in a mini-oscilloscope, the crew radio, and other crew equipment. These applications provide a basis for other Orbiter systems that require portable, storable, electrical power as well as emergency power for the Space Station major payload systems power and for Space Station equipment applications.

A self-adaptive toll rate algorithm for high occupancy toll (HOT) lane operations.

DOT National Transportation Integrated Search

2009-12-01

Dramatically increasing travel demands and insufficient traffic facility supplies have resulted in severe : traffic congestion. High Occupancy Toll (HOT) lane operations have been proposed as one of the most : applicable and cost-effective countermea...

Poultry litter application to loblolly pine forests: growth and nutrient containment.

PubMed

Friend, Alexander L; Roberts, Scott D; Schoenholtz, Stephen H; Mobley, Juanita A; Gerard, Patrick D

2006-01-01

Forestland application of poultry manure offers an alternative to the conventional practice of pastureland application. Before such a practice is considered viable, however, it must be demonstrated that the forest ecosystem is capable of absorbing the nutrients contained in poultry manure, especially nitrogen (N) and phosphorus (P). From the forestry perspective, it must also be demonstrated that tree growth is not diminished. We investigated these questions using loblolly pine (Pinus taeda L.) stands growing in central Mississippi in an area of high poultry production. Stockpiled broiler litter was applied to newly thinned, 8-yr-old stands at 0, 4.6, and 18.6 dry Mg ha-1, supplying 0, 200, and 800 kg N ha-1 and 0, 92, and 370 kg P ha-1, respectively. Levels of nitrate in soil water, monitored at a 50-cm depth with porous cup tension lysimeters, exceeded 10 mg N L-1 during the first two years after application in the 18.6 Mg ha-1 rate but only on two occasions in the first year for the lower rate of application. Phosphate was largely absent from lysimeter water in all treatments. Other macronutrients (K, Ca, Mg, S) were elevated in lysimeter water in proportion to litter application rates. Soil extractable nitrate showed similar trends to lysimeter water, with substantial elevation during the first year following application for the 18.6 Mg ha-1 rate. Mehlich III-extractable phosphate peaked in excess of 100 microg P g-1 soil during the third year of the study for the 18.6 Mg ha-1 rate. The 4.6 Mg ha-1 rate did not affect extractable soil P. Tree growth was increased by the poultry litter. Total stem cross-sectional area, or basal area, was approximately 20% greater after 2 yr for both rates of litter application. Overall, the nutrients supplied by the 4.6 Mg ha-1 rate were contained by the pine forest and resulted in favorable increases in tree growth. The higher rate, by contrast, did pose some risk to water quality through the mobilization of nitrate. These results show that, under the conditions of this study, application of poultry litter at moderate rates of approximately 5 Mg ha-1 to young stands of loblolly pine offers an alternative disposal option with minimal impacts to water quality and potential increases in tree growth.

Ultrathin single-crystalline TiO2 nanosheets anchored on graphene to be hybrid network for high-rate and long cycle-life sodium battery electrode application

NASA Astrophysics Data System (ADS)

Shoaib, Anwer; Huang, Yongxin; Liu, Jia; Liu, Jiajia; Xu, Meng; Wang, Ziheng; Chen, Renjie; Zhang, Jiatao; Wu, Feng

2017-02-01

In view of the growing concern about energy management issues, sodium ion batteries (SIBs) as cheap and environmentally friendly devices have increasingly received wide research attentions. The high current rate and long cycle-life of SIBs are considered as two key parameters determining its potential for practical applications. In this work, the rigid single-crystalline anatase TiO2 nanosheets (NSs) with a thickness of ∼4 nm has been firstly prepared, based on which a stable nanostructured network consisting of ultrathin anatase TiO2 NSs homogeneously anchored on graphene through chemical bonding (TiO2 NSs-G) has fabricated by hydrothermal process and subsequent calcination treatment. The morphology, crystallization, chemical compositions and the intimate maximum contact between TiO2 NSs and graphene are confirmed by TEM, SEM, XRD, XPS and Raman characterizations. The results of electrochemical performance tests indicated that the TiO2 NSs-G hybrid network could be consider as a promising anode material for SIBs, in assessment of its remarkably high current rate and long cycle-life aside from the improved specific capacity, rate capability and cycle stability.

Pile-up correction algorithm based on successive integration for high count rate medical imaging and radiation spectroscopy

NASA Astrophysics Data System (ADS)

Mohammadian-Behbahani, Mohammad-Reza; Saramad, Shahyar

2018-07-01

In high count rate radiation spectroscopy and imaging, detector output pulses tend to pile up due to high interaction rate of the particles with the detector. Pile-up effects can lead to a severe distortion of the energy and timing information. Pile-up events are conventionally prevented or rejected by both analog and digital electronics. However, for decreasing the exposure times in medical imaging applications, it is important to maintain the pulses and extract their true information by pile-up correction methods. The single-event reconstruction method is a relatively new model-based approach for recovering the pulses one-by-one using a fitting procedure, for which a fast fitting algorithm is a prerequisite. This article proposes a fast non-iterative algorithm based on successive integration which fits the bi-exponential model to experimental data. After optimizing the method, the energy spectra, energy resolution and peak-to-peak count ratios are calculated for different counting rates using the proposed algorithm as well as the rejection method for comparison. The obtained results prove the effectiveness of the proposed method as a pile-up processing scheme designed for spectroscopic and medical radiation detection applications.

2D and 3D impellers of centrifugal compressors - advantages, shortcomings and fields of application

NASA Astrophysics Data System (ADS)

Galerkin, Y.; Reksrin, A.; Drozdov, A.

2017-08-01

The simplified equations are presented for calculation of inlet dimensions and velocity values for impellers with three-dimensional blades located in axial and radial part of an impeller (3D impeller) and with two-dimensional blades in radial part (2D). Considerations concerning loss coefficients of 3D and 2D impellers at different design flow rate coefficients are given. The tendency of reduction of potential advantages of 3D impellers at medium and small design flow rate coefficients is shown. The data on high-efficiency compressors and stages with 2D impellers coefficients designed by the authors are presented. The reached efficiency level of 88 - 90% makes further increase of efficiency by the application of 3D impellers doubtful. CFD-analysis of stage candidates with medium flow rate coefficient with 3D and 2D impellers revealed specific problems. In some cases the constructive advantage of a 2D impeller is smaller hub ratio. It makes possible the reaching of higher efficiency. From other side, there is a positive tendency of gas turbine drive RPM increase. 3D impellers have no alternative for stages with high flow rate coefficients matching high-speed drive.

Calculated hydroxyl A2 sigma --> X2 pi (0, 0) band emission rate factors applicable to atmospheric spectroscopy

NASA Technical Reports Server (NTRS)

Cageao, R. P.; Ha, Y. L.; Jiang, Y.; Morgan, M. F.; Yung, Y. L.; Sander, S. P.

1997-01-01

A calculation of the A2 sigma --> X2 pi (0, 0) band emission rate factors and line center absorption cross sections of OH applicable to its measurement using solar resonant fluorescence in the terrestrial atmosphere is presented in this paper. The most accurate available line parameters have been used. Special consideration has been given to the solar input flux because of its highly structured Fraunhofer spectrum. The calculation for the OH atmospheric emission rate factor in the solar resonant fluorescent case is described in detail with examples and intermediate results. Results of this calculation of OH emission rate factors for individual rotational lines are on average 30% lower than the values obtained in an earlier work.

Rational Phosphorus Application Facilitates the Sustainability of the Wheat/Maize/Soybean Relay Strip Intercropping System

PubMed Central

Wang, Ke; Liu, Jing; Lu, Junyu; Xu, Kaiwei

2015-01-01

Wheat (Triticum aestivum L.)/maize (Zea mays L.)/soybean (Glycine max L.) relay strip intercropping (W/M/S) system is commonly used by the smallholders in the Southwest of China. However, little known is how to manage phosphorus (P) to enhance P use efficiency of the W/M/S system and to mitigate P leaching that is a major source of pollution. Field experiments were carried out in 2011, 2012, and 2013 to test the impact of five P application rates on yield and P use efficiency of the W/M/S system. The study measured grain yield, shoot P uptake, apparent P recovery efficiency (PRE) and soil P content. A linear-plateau model was used to determine the critical P rate that maximizes gains in the indexes of system productivity. The results show that increase in P application rates aggrandized shoot P uptake and crops yields at threshold rates of 70 and 71.5 kg P ha-1 respectively. With P application rates increasing, the W/M/S system decreased the PRE from 35.9% to 12.3% averaged over the three years. A rational P application rate, 72 kg P ha-1, or an appropriate soil Olsen-P level, 19.1 mg kg-1, drives the W/M/S system to maximize total grain yield while minimizing P surplus, as a result of the PRE up to 28.0%. We conclude that rational P application is an important approach for relay intercropping to produce high yield while mitigating P pollution and the rational P application-based integrated P fertilizer management is vital for sustainable intensification of agriculture in the Southwest of China. PMID:26540207

Zero-voltage DC/DC converter with asymmetric pulse-width modulation for DC micro-grid system

NASA Astrophysics Data System (ADS)

Lin, Bor-Ren

2018-04-01

This paper presents a zero-voltage switching DC/DC converter for DC micro-grid system applications. The proposed circuit includes three half-bridge circuit cells connected in primary-series and secondary-parallel in order to lessen the voltage rating of power switches and current rating of rectifier diodes. Thus, low voltage stress of power MOSFETs can be adopted for high-voltage input applications with high switching frequency operation. In order to achieve low switching losses and high circuit efficiency, asymmetric pulse-width modulation is used to turn on power switches at zero voltage. Flying capacitors are used between each circuit cell to automatically balance input split voltages. Therefore, the voltage stress of each power switch is limited at Vin/3. Finally, a prototype is constructed and experiments are provided to demonstrate the circuit performance.

Single-Mode, High Repetition Rate, Compact Ho:YLF Laser for Space-Borne Lidar Applications

NASA Technical Reports Server (NTRS)

Bai, Yingxin; Yu, Jirong; Wong, Teh-Hwa; Chen, Songsheng; Petros, Mulugeta; Singh, Upendra N.

2014-01-01

A single transverse/longitudinal mode, compact Q-switched Ho:YLF laser has been designed and demonstrated for space-borne lidar applications. The pulse energy is between 34-40 mJ for 100-200 Hz operation. The corresponding peak power is >1 MW.

Field application of glyphosate induces molecular changes affecting vegetative growth processes in leafy spurge

USDA-ARS?s Scientific Manuscript database

Recommended rates of glyphosate for non-cultivated areas destroy the aboveground shoots of the perennial plant leafy spurge. However, such applications cause little or no damage to underground adventitious buds (UABs), and thus the plant readily regenerates vegetatively. High concentrations of glyph...

Concept for the fast modulation of light in amplitude and phase using analog tilt-mirror arrays

NASA Astrophysics Data System (ADS)

Roth, Matthias; Heber, Jörg; Janschek, Klaus

2017-02-01

The full complex, spatial modulation of light at high frame rates is essential for a variety of applications. In particular, emerging techniques applied to scattering media, such as Digital Optical Phase Conjugation and Wavefront Shaping, request challenging performance parameters. They refer to imaging tasks inside biological media, whose characteristics concerning the transmission and reflection of scattered light may change over time within milliseconds. Thus, these methods call for frame rates in the kilohertz range. Existing solutions typically over frame rate capabilities below 100 Hz, since they rely on liquid crystal spatial light modulators (SLMs). We propose a diffractive MEMS optical system for this application range. It relies on an analog, tilt-type micro mirror array (MMA) based on an established SLM technology, where the standard application is grayscale amplitude control. The new MMA system design allows the phase manipulation at high-speed as well. The article studies properties of the appropriate optical setup by simulating the propagation of the light. Relevant test patterns and sensitivity parameters of the system will be analyzed. Our results illustrate the main opportunities of the concept with particular focus on the tilt mirror technology. They indicate a promising path to realize the complex light modulation at frame rates above 1 kHz and resolutions well beyond 10,000 complex pixels.

High-rate composting of barley dregs with sewage sludge in a pilot scale bioreactor.

PubMed

Lu, Li-An; Kumar, Mathava; Tsai, Jen-Chieh; Lin, Jih-Gaw

2008-05-01

The feasibility of high-rate composting of barley dregs and sewage sludge was examined using a pilot scale bioreactor. A central composite design (CCD) was used to optimize the mix ratio of barley dregs/sewage sludge and moisture content. The performance of the bioreactor was monitored as a function of carbon decomposition rate (CDR) and total volatile solids (TVS) loss rate. The optimum range of mix ratio and moisture content was found to be 35-40% and 55-60%, respectively. High CO2 evolution rate (CER) and TVS loss rate were observed after 3 days of the composting and the compost was matured/stable after 7 days. Cardinal temperature model with inflection (CTMI) was used to analyze the compost stability with respect to CER as a parameter of composting efficiency. After examining the phytotoxicity, the compost can be promoted for land application.

High-Speed Videography Overview

NASA Astrophysics Data System (ADS)

Miller, C. E.

1989-02-01

The field of high-speed videography (HSV) has continued to mature in recent years, due to the introduction of a mixture of new technology and extensions of existing technology. Recent low frame-rate innovations have the potential to dramatically expand the areas of information gathering and motion analysis at all frame-rates. Progress at the 0 - rate is bringing the battle of film versus video to the field of still photography. The pressure to push intermediate frame rates higher continues, although the maximum achievable frame rate has remained stable for several years. Higher maximum recording rates appear technologically practical, but economic factors impose severe limitations to development. The application of diverse photographic techniques to video-based systems is under-exploited. The basics of HSV apply to other fields, such as machine vision and robotics. Present motion analysis systems continue to function mainly as an instant replay replacement for high-speed movie film cameras. The interrelationship among lighting, shuttering and spatial resolution is examined.

Characterization of a New Fully Recycled Carbon Fiber Reinforced Composite Subjected to High Strain Rate Tension

NASA Astrophysics Data System (ADS)

Meftah, H.; Tamboura, S.; Fitoussi, J.; BenDaly, H.; Tcharkhtchi, A.

2017-08-01

The aim of this study is the complete physicochemical characterization and strain rate effect multi-scale analysis of a new fully recycled carbon fiber reinforced composites for automotive crash application. Two composites made of 20% wt short recycled carbon fibers (CF) are obtained by injection molding. The morphology and the degree of dispersion of CF in the matrixes were examined using a new ultrasonic method and SEM. High strain tensile behavior up to 100 s-1 is investigated. In order to avoid perturbation due to inertial effect and wave propagation, the specimen geometry was optimized. The elastic properties appear to be insensitive to the strain rate. However, a high strain rate effect on the local visco-plasticity of the matrix and fiber/matrix interface visco-damageable behavior is emphasized. The predominant damage mechanisms evolve from generalized matrix local ductility at low strain rate regime to fiber/matrix interface debonding and fibers pull-out at high strain rate regime.

Sodium vanadium titanium phosphate electrode for symmetric sodium-ion batteries with high power and long lifespan

PubMed Central

Wang, Dongxue; Bie, Xiaofei; Fu, Qiang; Dixon, Ditty; Bramnik, Natalia; Hu, Yong-Sheng; Fauth, Francois; Wei, Yingjin; Ehrenberg, Helmut; Chen, Gang; Du, Fei

2017-01-01

Sodium-ion batteries operating at ambient temperature hold great promise for use in grid energy storage owing to their significant cost advantages. However, challenges remain in the development of suitable electrode materials to enable long lifespan and high rate capability. Here we report a sodium super-ionic conductor structured electrode, sodium vanadium titanium phosphate, which delivers a high specific capacity of 147 mA h g−1 at a rate of 0.1 C and excellent capacity retentions at high rates. A symmetric sodium-ion full cell demonstrates a superior rate capability with a specific capacity of about 49 mA h g−1 at 20 C rate and ultralong lifetime over 10,000 cycles. Furthermore, in situ synchrotron diffraction and X-ray absorption spectroscopy measurement are carried out to unravel the underlying sodium storage mechanism and charge compensation behaviour. Our results suggest the potential application of symmetric batteries for electrochemical energy storage given the superior rate capability and long cycle life. PMID:28660877

Sodium vanadium titanium phosphate electrode for symmetric sodium-ion batteries with high power and long lifespan.

PubMed

Wang, Dongxue; Bie, Xiaofei; Fu, Qiang; Dixon, Ditty; Bramnik, Natalia; Hu, Yong-Sheng; Fauth, Francois; Wei, Yingjin; Ehrenberg, Helmut; Chen, Gang; Du, Fei

2017-06-29

Sodium-ion batteries operating at ambient temperature hold great promise for use in grid energy storage owing to their significant cost advantages. However, challenges remain in the development of suitable electrode materials to enable long lifespan and high rate capability. Here we report a sodium super-ionic conductor structured electrode, sodium vanadium titanium phosphate, which delivers a high specific capacity of 147 mA h g -1 at a rate of 0.1 C and excellent capacity retentions at high rates. A symmetric sodium-ion full cell demonstrates a superior rate capability with a specific capacity of about 49 mA h g -1 at 20 C rate and ultralong lifetime over 10,000 cycles. Furthermore, in situ synchrotron diffraction and X-ray absorption spectroscopy measurement are carried out to unravel the underlying sodium storage mechanism and charge compensation behaviour. Our results suggest the potential application of symmetric batteries for electrochemical energy storage given the superior rate capability and long cycle life.

Characterization of a New Fully Recycled Carbon Fiber Reinforced Composite Subjected to High Strain Rate Tension

NASA Astrophysics Data System (ADS)

Meftah, H.; Tamboura, S.; Fitoussi, J.; BenDaly, H.; Tcharkhtchi, A.

2018-06-01

The aim of this study is the complete physicochemical characterization and strain rate effect multi-scale analysis of a new fully recycled carbon fiber reinforced composites for automotive crash application. Two composites made of 20% wt short recycled carbon fibers (CF) are obtained by injection molding. The morphology and the degree of dispersion of CF in the matrixes were examined using a new ultrasonic method and SEM. High strain tensile behavior up to 100 s-1 is investigated. In order to avoid perturbation due to inertial effect and wave propagation, the specimen geometry was optimized. The elastic properties appear to be insensitive to the strain rate. However, a high strain rate effect on the local visco-plasticity of the matrix and fiber/matrix interface visco-damageable behavior is emphasized. The predominant damage mechanisms evolve from generalized matrix local ductility at low strain rate regime to fiber/matrix interface debonding and fibers pull-out at high strain rate regime.

High energy density micro-fiber based nickel electrode for aerospace batteries

NASA Technical Reports Server (NTRS)

Francisco, Jennifer; Chiappetti, Dennis; Coates, Dwaine

1996-01-01

The nickel electrode is the specific energy limiting component in battery systems such as nickel-hydrogen, nickel-metal hydride and nickel-zinc. Lightweight, high energy density nickel electrodes have been developed which deliver in excess of 180 mAh/g at the one-hour discharge rate. These electrodes are based on a highly porous, nickel micro-fiber (less than 10 micron diameter) substrate, electrochemically impregnated with nickel-hydroxide active material. Electrodes are being tested both as a flooded half-cell and in full nickel-hydrogen and nickel-metal hydride cells. The electrode technology developed is applicable to commercial nickel-based batteries for applications such as electric vehicles, cellular telephones and laptop computers and for low-cost, high energy density military and aerospace applications.

Design and characterization of a new high-dose-rate brachytherapy Valencia applicator for larger skin lesions

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

Candela-Juan, C., E-mail: ccanjuan@gmail.com; Niatsetski, Y.; Laarse, R. van der

Purpose: The aims of this study were (i) to design a new high-dose-rate (HDR) brachytherapy applicator for treating surface lesions with planning target volumes larger than 3 cm in diameter and up to 5 cm in size, using the microSelectron-HDR or Flexitron afterloader (Elekta Brachytherapy) with a {sup 192}Ir source; (ii) to calculate by means of the Monte Carlo (MC) method the dose distribution for the new applicator when it is placed against a water phantom; and (iii) to validate experimentally the dose distributions in water. Methods: The PENELOPE2008 MC code was used to optimize dwell positions and dwell times.more » Next, the dose distribution in a water phantom and the leakage dose distribution around the applicator were calculated. Finally, MC data were validated experimentally for a {sup 192}Ir mHDR-v2 source by measuring (i) dose distributions with radiochromic EBT3 films (ISP); (ii) percentage depth–dose (PDD) curve with the parallel-plate ionization chamber Advanced Markus (PTW); and (iii) absolute dose rate with EBT3 films and the PinPoint T31016 (PTW) ionization chamber. Results: The new applicator is made of tungsten alloy (Densimet) and consists of a set of interchangeable collimators. Three catheters are used to allocate the source at prefixed dwell positions with preset weights to produce a homogenous dose distribution at the typical prescription depth of 3 mm in water. The same plan is used for all available collimators. PDD, absolute dose rate per unit of air kerma strength, and off-axis profiles in a cylindrical water phantom are reported. These data can be used for treatment planning. Leakage around the applicator was also scored. The dose distributions, PDD, and absolute dose rate calculated agree within experimental uncertainties with the doses measured: differences of MC data with chamber measurements are up to 0.8% and with radiochromic films are up to 3.5%. Conclusions: The new applicator and the dosimetric data provided here will be a valuable tool in clinical practice, making treatment of large skin lesions simpler, faster, and safer. Also the dose to surrounding healthy tissues is minimal.« less

Acceleration of atmospheric Cherenkov telescope signal processing to real-time speed with the Auto-Pipe design system

NASA Astrophysics Data System (ADS)

Tyson, Eric J.; Buckley, James; Franklin, Mark A.; Chamberlain, Roger D.

2008-10-01

The imaging atmospheric Cherenkov technique for high-energy gamma-ray astronomy is emerging as an important new technique for studying the high energy universe. Current experiments have data rates of ≈20TB/year and duty cycles of about 10%. In the future, more sensitive experiments may produce up to 1000 TB/year. The data analysis task for these experiments requires keeping up with this data rate in close to real-time. Such data analysis is a classic example of a streaming application with very high performance requirements. This class of application often benefits greatly from the use of non-traditional approaches for computation including using special purpose hardware (FPGAs and ASICs), or sophisticated parallel processing techniques. However, designing, debugging, and deploying to these architectures is difficult and thus they are not widely used by the astrophysics community. This paper presents the Auto-Pipe design toolset that has been developed to address many of the difficulties in taking advantage of complex streaming computer architectures for such applications. Auto-Pipe incorporates a high-level coordination language, functional and performance simulation tools, and the ability to deploy applications to sophisticated architectures. Using the Auto-Pipe toolset, we have implemented the front-end portion of an imaging Cherenkov data analysis application, suitable for real-time or offline analysis. The application operates on data from the VERITAS experiment, and shows how Auto-Pipe can greatly ease performance optimization and application deployment of a wide variety of platforms. We demonstrate a performance improvement over a traditional software approach of 32x using an FPGA solution and 3.6x using a multiprocessor based solution.

Billion frames per second spectrum measurement for high-repetition-rate optical pulses based on time stretching technique

NASA Astrophysics Data System (ADS)

Furukawa, Hideaki; Makino, Takeshi; Asghari, Mohammad H.; Trinh, Paul; Jalali, Bahram; Wang, Xiaomin; Kobayashi, Tetsuya; Man, Wai S.; Tsang, Kwong Shing; Wada, Naoya

2017-02-01

Single-shot and long record length spectrum measurements of high-repetition-rate optical pulses are essential for research on nonlinear dynamics as well as for applications in sensing and communication. To achieve a continuous measurements we employ the Time Stretch Dispersive Fourier Transform. We show single-shot measurements of millions of sequential pulses at high repetition rate of 1 Giga spectra per second. Results were obtained using -100 ps/nm dispersive Fourier transform module and a 50 Gsample/s real-time digitizer of 16 GHz bandwidth. Single-shot spectroscopy of 1 GHz optical pulse train was achieved with the wavelength resolution of approximately 150 pm. This instrument is ideal for observation of complex nonlinear dynamics such as switching, mode locking and soliton dynamics in high repetition rate lasers.

Effect of application rate on fumigant degradation in five agricultural soils

USDA-ARS?s Scientific Manuscript database

Fumigants continue to be used in soil disinfestation for many high value crops. There is a significant knowledge gap on how fumigant concentration in soil impacts fumigant dissipation and determination of the most efficient rate. The aim of this study was to determine the degradation characteristics...

Statistical methods for thermonuclear reaction rates and nucleosynthesis simulations

NASA Astrophysics Data System (ADS)

Iliadis, Christian; Longland, Richard; Coc, Alain; Timmes, F. X.; Champagne, Art E.

2015-03-01

Rigorous statistical methods for estimating thermonuclear reaction rates and nucleosynthesis are becoming increasingly established in nuclear astrophysics. The main challenge being faced is that experimental reaction rates are highly complex quantities derived from a multitude of different measured nuclear parameters (e.g., astrophysical S-factors, resonance energies and strengths, particle and γ-ray partial widths). We discuss the application of the Monte Carlo method to two distinct, but related, questions. First, given a set of measured nuclear parameters, how can one best estimate the resulting thermonuclear reaction rates and associated uncertainties? Second, given a set of appropriate reaction rates, how can one best estimate the abundances from nucleosynthesis (i.e., reaction network) calculations? The techniques described here provide probability density functions that can be used to derive statistically meaningful reaction rates and final abundances for any desired coverage probability. Examples are given for applications to s-process neutron sources, core-collapse supernovae, classical novae, and Big Bang nucleosynthesis.

SU-G-TeP2-10: Feasibility of Newly Designed Applicator for High Dose Rate Brachytherapy Treatment of Patients with Vaginal Vault Recurrence

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

Lee, V; Wong, M; Chan, M

Purpose: To compare the dose of an in-house 3D-printed gynecology applicator (TMHGA) for vaginal vault recurrence of corpus cancer patients after operation for high dose rate brachytherapy treatment with commercially available applicators. Methods: A newly designed applicator is made from 3D-printing methods using ABSM30i. The isodose of the applicator is compared with Elekta multi-channel (MC) applicator and titanium Rotterdam applicator with coupling central tube and vaginal cylinder (RC). Three plans are created using three applicators in a CT set of water phantom. The applicators are anchored using the applicator library and implant library in the Elekta Oncentra treatment planning systemmore » (ver.4.5). The rectum is mimicked by creating a 2cm diameter cylinder, with a distance 1mm posteriorly away from the high risk CTV (HR-CTV). Similarly, the bladder is replicated by a 6cm diameter cylinder with distance 1mm anteriorly from the HR-CTV. Three plans are all normalized 1.5cm superior, 0.5cm anterior and 0.5cm posterior of the applicator surface. By fixing D90 of HR-CTV to 6Gy, the D2cc of rectum and bladder of three plans are compared. Results: The D2cc of the bladder for using TMHGA is lower than MC and RC by 14.0% and 11.9% respectively. While the D2cc of the rectum for using TMHGA is lower than MC and RC by 18.9% and 12.4% respectively. The total treatment time of TMHGA plan is shorter than MC and RC by 11.2% and 12.9%. Conclusion: The applicator created via 3D printing delivers a lower dose to the bladder and the rectum while keeping the same coverage to HR-CTV as other commercially available applicators. Additionally, the new applicator resulted in a reduction of treatment time, which is always welcome.« less

A High Performance Image Data Compression Technique for Space Applications

NASA Technical Reports Server (NTRS)

Yeh, Pen-Shu; Venbrux, Jack

2003-01-01

A highly performing image data compression technique is currently being developed for space science applications under the requirement of high-speed and pushbroom scanning. The technique is also applicable to frame based imaging data. The algorithm combines a two-dimensional transform with a bitplane encoding; this results in an embedded bit string with exact desirable compression rate specified by the user. The compression scheme performs well on a suite of test images acquired from spacecraft instruments. It can also be applied to three-dimensional data cube resulting from hyper-spectral imaging instrument. Flight qualifiable hardware implementations are in development. The implementation is being designed to compress data in excess of 20 Msampledsec and support quantization from 2 to 16 bits. This paper presents the algorithm, its applications and status of development.

Naegele Forceps Delivery and Association between Morbidity and the Number of Forceps Traction Applications: A Retrospective Study.

PubMed

Matsumoto, Naoki; Takenaka, Toshifumi; Ikeda, Nobuyuki; Yazaki, Satoshi; Sato, Yuichi

2015-01-01

To present the method of Naegele forceps delivery clinically practiced by the lead author, its success rate, and morbidity and to evaluate the relationship between morbidity and the number of forceps traction applications. Naegele forceps delivery was performed when the fetal head reached station +2 cm, the forceps were applied in the maternal pelvic application, and traction was slowly and gently performed. In the past two years, Naegele forceps delivery was attempted by the lead author in 87 cases, which were retrospectively reviewed. The numbers of traction applications were one in 64.7% of cases, two in 24.7%, and three or more in 10.7%. The success rate was 100%. No severe morbidity was observed in mothers or neonates. Neonatal facial injury occurred most commonly in cases with fetal head malrotation, elevated numbers of traction applications, and maternal complications. Umbilical artery acidemia most commonly occurred in cases with nonreassuring fetal status. The significant crude odds ratio for three or more traction applications was 20 in cases with malrotation. Naegele forceps delivery has a high success rate, but multiple traction applications will sometimes be required, particularly in cases with malrotation. Malrotation and elevated numbers of traction applications may lead to neonatal head damage.

Sorting drops and cells with acoustics: acoustic microfluidic fluorescence-activated cell sorter.

PubMed

Schmid, Lothar; Weitz, David A; Franke, Thomas

2014-10-07

We describe a versatile microfluidic fluorescence-activated cell sorter that uses acoustic actuation to sort cells or drops at ultra-high rates. Our acoustic sorter combines the advantages of traditional fluorescence-activated cell (FACS) and droplet sorting (FADS) and is applicable for a multitude of objects. We sort aqueous droplets, at rates as high as several kHz, into two or even more outlet channels. We can also sort cells directly from the medium without prior encapsulation into drops; we demonstrate this by sorting fluorescently labeled mouse melanoma cells in a single phase fluid. Our acoustic microfluidic FACS is compatible with standard cell sorting cytometers, yet, at the same time, enables a rich variety of more sophisticated applications.

Relativistic all-order many-body calculation of energies, wavelengths, and M 1 and E 2 transition rates for the 3 dn configurations in tungsten ions

NASA Astrophysics Data System (ADS)

Safronova, M. S.; Safronova, U. I.; Porsev, S. G.; Kozlov, M. G.; Ralchenko, Yu.

2018-01-01

Energy levels, wavelengths, magnetic-dipole and electric-quadrupole transition rates between the low-lying states are evaluated for W51 + to W54 + ions with 3 dn (n =2 to 5) electronic configurations by using an approach combining configuration interaction with the linearized coupled-cluster single-double method. The QED corrections are directly incorporated into the calculations and their effect is studied in detail. Uncertainties of the calculations are discussed. This study of such highly charged ions with the present method opens the way for future applications allowing an accurate prediction of properties for a very wide range of highly charged ions aimed at providing precision benchmarks for various applications.

Emission quantification using the tracer gas dispersion method: The influence of instrument, tracer gas species and source simulation.

PubMed

Delre, Antonio; Mønster, Jacob; Samuelsson, Jerker; Fredenslund, Anders M; Scheutz, Charlotte

2018-09-01

The tracer gas dispersion method (TDM) is a remote sensing method used for quantifying fugitive emissions by relying on the controlled release of a tracer gas at the source, combined with concentration measurements of the tracer and target gas plumes. The TDM was tested at a wastewater treatment plant for plant-integrated methane emission quantification, using four analytical instruments simultaneously and four different tracer gases. Measurements performed using a combination of an analytical instrument and a tracer gas, with a high ratio between the tracer gas release rate and instrument precision (a high release-precision ratio), resulted in well-defined plumes with a high signal-to-noise ratio and a high methane-to-tracer gas correlation factor. Measured methane emission rates differed by up to 18% from the mean value when measurements were performed using seven different instrument and tracer gas combinations. Analytical instruments with a high detection frequency and good precision were established as the most suitable for successful TDM application. The application of an instrument with a poor precision could only to some extent be overcome by applying a higher tracer gas release rate. A sideward misplacement of the tracer gas release point of about 250m resulted in an emission rate comparable to those obtained using a tracer gas correctly simulating the methane emission. Conversely, an upwind misplacement of about 150m resulted in an emission rate overestimation of almost 50%, showing the importance of proper emission source simulation when applying the TDM. Copyright © 2018 Elsevier B.V. All rights reserved.

High reliability level on single-mode 980nm-1060 nm diode lasers for telecommunication and industrial applications

NASA Astrophysics Data System (ADS)

Van de Casteele, J.; Bettiati, M.; Laruelle, F.; Cargemel, V.; Pagnod-Rossiaux, P.; Garabedian, P.; Raymond, L.; Laffitte, D.; Fromy, S.; Chambonnet, D.; Hirtz, J. P.

2008-02-01

We demonstrate very high reliability level on 980-1060nm high-power single-mode lasers through multi-cell tests. First, we show how our chip design and technology enables high reliability levels. Then, we aged 758 devices during 9500 hours among 6 cells with high current (0.8A-1.2A) and high submount temperature (65°C-105°C) for the reliability demonstration. Sudden catastrophic failure is the main degradation mechanism observed. A statistical failure rate model gives an Arrhenius thermal activation energy of 0.51eV and a power law forward current acceleration factor of 5.9. For high-power submarine applications (360mW pump module output optical power), this model exhibits a failure rate as low as 9 FIT at 13°C, while ultra-high power terrestrial modules (600mW) lie below 220 FIT at 25°C. Wear-out phenomena is observed only for very high current level without any reliability impact under 1.1A. For the 1060nm chip, step-stress tests were performed and a set of devices were aged during more than 2000 hours in different stress conditions. First results are in accordance with 980nm product with more than 100khours estimated MTTF. These reliability and performance features of 980-1060nm laser diodes will make high-power single-mode emitters the best choice for a number of telecommunication and industrial applications in the next few years.

Evaluation of super-water reducers for highway applications

NASA Astrophysics Data System (ADS)

Whiting, D.

1981-03-01

Super-water reducers were characterized and evaluated as potential candidates for production of low water to cement ratio, high strength concretes for highway construction applications. Admixtures were composed of either naphthalene or melamine sulfonated formaldehyde condensates. A mini-slump procedure was used to assess dosage requirements and behavior of workability with time of cement pastes. Required dosage was found to be a function of tricalcium aluminate content, alkali content, and fineness of the cement. Concretes exhibited high rates of slump loss when super-water reducers were used. The most promising area of application of these products appears to be in production of dense, high cement content concrete using mobile concrete mixer/transporters.

Ethylene Trace-gas Techniques for High-speed Flows

NASA Technical Reports Server (NTRS)

Davis, David O.; Reichert, Bruce A.

1994-01-01

Three applications of the ethylene trace-gas technique to high-speed flows are described: flow-field tracking, air-to-air mixing, and bleed mass-flow measurement. The technique involves injecting a non-reacting gas (ethylene) into the flow field and measuring the concentration distribution in a downstream plane. From the distributions, information about flow development, mixing, and mass-flow rates can be dtermined. The trace-gas apparatus and special considerations for use in high-speed flow are discussed. A description of each application, including uncertainty estimates is followed by a demonstrative example.

Assessment and application of Reynolds stress closure models to high-speed compressible flows

NASA Technical Reports Server (NTRS)

Gatski, T. B.; Sarkar, S.; Speziale, C. G.; Balakrishnan, L.; Abid, R.; Anderson, E. C.

1990-01-01

The paper presents results from the development of higher order closure models for the phenomological modeling of high-speed compressible flows. The work presented includes the introduction of an improved pressure-strain correlationi model applicable in both the low- and high-speed regime as well as modifications to the isotropic dissipation rate to account for dilatational effects. Finally, the question of stiffness commonly associated with the solution of two-equation and Reynolds stress transport equations in wall-bounded flows is examined and ways of relaxing these restrictions are discussed.

Energy dispersive CdTe and CdZnTe detectors for spectral clinical CT and NDT applications

NASA Astrophysics Data System (ADS)

Barber, W. C.; Wessel, J. C.; Nygard, E.; Iwanczyk, J. S.

2015-06-01

We are developing room temperature compound semiconductor detectors for applications in energy-resolved high-flux single x-ray photon-counting spectral computed tomography (CT), including functional imaging with nanoparticle contrast agents for medical applications and non-destructive testing (NDT) for security applications. Energy-resolved photon-counting can provide reduced patient dose through optimal energy weighting for a particular imaging task in CT, functional contrast enhancement through spectroscopic imaging of metal nanoparticles in CT, and compositional analysis through multiple basis function material decomposition in CT and NDT. These applications produce high input count rates from an x-ray generator delivered to the detector. Therefore, in order to achieve energy-resolved single photon counting in these applications, a high output count rate (OCR) for an energy-dispersive detector must be achieved at the required spatial resolution and across the required dynamic range for the application. The required performance in terms of the OCR, spatial resolution, and dynamic range must be obtained with sufficient field of view (FOV) for the application thus requiring the tiling of pixel arrays and scanning techniques. Room temperature cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) compound semiconductors, operating as direct conversion x-ray sensors, can provide the required speed when connected to application specific integrated circuits (ASICs) operating at fast peaking times with multiple fixed thresholds per pixel provided the sensors are designed for rapid signal formation across the x-ray energy ranges of the application at the required energy and spatial resolutions, and at a sufficiently high detective quantum efficiency (DQE). We have developed high-flux energy-resolved photon-counting x-ray imaging array sensors using pixellated CdTe and CdZnTe semiconductors optimized for clinical CT and security NDT. We have also fabricated high-flux ASICs with a two dimensional (2D) array of inputs for readout from the sensors. The sensors are guard ring free and have a 2D array of pixels and can be tiled in 2D while preserving pixel pitch. The 2D ASICs have four energy bins with a linear energy response across sufficient dynamic range for clinical CT and some NDT applications. The ASICs can also be tiled in 2D and are designed to fit within the active area of the sensors. We have measured several important performance parameters including: the output count rate (OCR) in excess of 20 million counts per second per square mm with a minimum loss of counts due to pulse pile-up, an energy resolution of 7 keV full width at half-maximum (FWHM) across the entire dynamic range, and a noise floor about 20 keV. This is achieved by directly interconnecting the ASIC inputs to the pixels of the CdZnTe sensors incurring very little input capacitance to the ASICs. We present measurements of the performance of the CdTe and CdZnTe sensors including the OCR, FWHM energy resolution, noise floor, as well as the temporal stability and uniformity under the rapidly varying high flux expected in CT and NDT applications.

Energy dispersive CdTe and CdZnTe detectors for spectral clinical CT and NDT applications

PubMed Central

Barber, W. C.; Wessel, J. C.; Nygard, E.; Iwanczyk, J. S.

2014-01-01

We are developing room temperature compound semiconductor detectors for applications in energy-resolved high-flux single x-ray photon-counting spectral computed tomography (CT), including functional imaging with nanoparticle contrast agents for medical applications and non destructive testing (NDT) for security applications. Energy-resolved photon-counting can provide reduced patient dose through optimal energy weighting for a particular imaging task in CT, functional contrast enhancement through spectroscopic imaging of metal nanoparticles in CT, and compositional analysis through multiple basis function material decomposition in CT and NDT. These applications produce high input count rates from an x-ray generator delivered to the detector. Therefore, in order to achieve energy-resolved single photon counting in these applications, a high output count rate (OCR) for an energy-dispersive detector must be achieved at the required spatial resolution and across the required dynamic range for the application. The required performance in terms of the OCR, spatial resolution, and dynamic range must be obtained with sufficient field of view (FOV) for the application thus requiring the tiling of pixel arrays and scanning techniques. Room temperature cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) compound semiconductors, operating as direct conversion x-ray sensors, can provide the required speed when connected to application specific integrated circuits (ASICs) operating at fast peaking times with multiple fixed thresholds per pixel provided the sensors are designed for rapid signal formation across the x-ray energy ranges of the application at the required energy and spatial resolutions, and at a sufficiently high detective quantum efficiency (DQE). We have developed high-flux energy-resolved photon-counting x-ray imaging array sensors using pixellated CdTe and CdZnTe semiconductors optimized for clinical CT and security NDT. We have also fabricated high-flux ASICs with a two dimensional (2D) array of inputs for readout from the sensors. The sensors are guard ring free and have a 2D array of pixels and can be tiled in 2D while preserving pixel pitch. The 2D ASICs have four energy bins with a linear energy response across sufficient dynamic range for clinical CT and some NDT applications. The ASICs can also be tiled in 2D and are designed to fit within the active area of the sensors. We have measured several important performance parameters including; the output count rate (OCR) in excess of 20 million counts per second per square mm with a minimum loss of counts due to pulse pile-up, an energy resolution of 7 keV full width at half maximum (FWHM) across the entire dynamic range, and a noise floor about 20keV. This is achieved by directly interconnecting the ASIC inputs to the pixels of the CdZnTe sensors incurring very little input capacitance to the ASICs. We present measurements of the performance of the CdTe and CdZnTe sensors including the OCR, FWHM energy resolution, noise floor, as well as the temporal stability and uniformity under the rapidly varying high flux expected in CT and NDT applications. PMID:25937684

Energy dispersive CdTe and CdZnTe detectors for spectral clinical CT and NDT applications.

PubMed

Barber, W C; Wessel, J C; Nygard, E; Iwanczyk, J S

2015-06-01

We are developing room temperature compound semiconductor detectors for applications in energy-resolved high-flux single x-ray photon-counting spectral computed tomography (CT), including functional imaging with nanoparticle contrast agents for medical applications and non destructive testing (NDT) for security applications. Energy-resolved photon-counting can provide reduced patient dose through optimal energy weighting for a particular imaging task in CT, functional contrast enhancement through spectroscopic imaging of metal nanoparticles in CT, and compositional analysis through multiple basis function material decomposition in CT and NDT. These applications produce high input count rates from an x-ray generator delivered to the detector. Therefore, in order to achieve energy-resolved single photon counting in these applications, a high output count rate (OCR) for an energy-dispersive detector must be achieved at the required spatial resolution and across the required dynamic range for the application. The required performance in terms of the OCR, spatial resolution, and dynamic range must be obtained with sufficient field of view (FOV) for the application thus requiring the tiling of pixel arrays and scanning techniques. Room temperature cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) compound semiconductors, operating as direct conversion x-ray sensors, can provide the required speed when connected to application specific integrated circuits (ASICs) operating at fast peaking times with multiple fixed thresholds per pixel provided the sensors are designed for rapid signal formation across the x-ray energy ranges of the application at the required energy and spatial resolutions, and at a sufficiently high detective quantum efficiency (DQE). We have developed high-flux energy-resolved photon-counting x-ray imaging array sensors using pixellated CdTe and CdZnTe semiconductors optimized for clinical CT and security NDT. We have also fabricated high-flux ASICs with a two dimensional (2D) array of inputs for readout from the sensors. The sensors are guard ring free and have a 2D array of pixels and can be tiled in 2D while preserving pixel pitch. The 2D ASICs have four energy bins with a linear energy response across sufficient dynamic range for clinical CT and some NDT applications. The ASICs can also be tiled in 2D and are designed to fit within the active area of the sensors. We have measured several important performance parameters including; the output count rate (OCR) in excess of 20 million counts per second per square mm with a minimum loss of counts due to pulse pile-up, an energy resolution of 7 keV full width at half maximum (FWHM) across the entire dynamic range, and a noise floor about 20keV. This is achieved by directly interconnecting the ASIC inputs to the pixels of the CdZnTe sensors incurring very little input capacitance to the ASICs. We present measurements of the performance of the CdTe and CdZnTe sensors including the OCR, FWHM energy resolution, noise floor, as well as the temporal stability and uniformity under the rapidly varying high flux expected in CT and NDT applications.

In situ assessment of pesticide genotoxicity in an integrated pest management program I--Tradescantia micronucleus assay.

PubMed

Rodrigues, G S; Pimentel, D; Weinstein, L H

1998-02-13

The genotoxicity induced by pesticides applied in an integrated pest management (IPM) program was evaluated with the Tradescantia micronucleus assay (Trad-MCN). Three pesticide application rates were prescribed as follows: (a) Low, no field pesticide spray; (b) Medium, IPM test rate: banded cyanazine plus metolachlor (2.7 kg a.i. and 2.3 l a.i./ha of herbicides, respectively); and (c) High, a preventative pesticide application program: broadcast cyanazine plus metolachlor (same application rates as above) plus chlorpyrifos (1 kg a.i./ha of insecticide). The Trad-MCN was employed for the assessment of (a) the formulated compounds, singly and in combinations; (b) pesticide residues extracted from soils sampled before and after application, and (c) in situ exposures (14-h exposure to pesticide-sprayed field). All pesticides showed clastogenic potency at doses between 10 and 50 ppm. Aqueous extracts of the two pesticide-sprayed soils were clastogenic, but the unsprayed soil extracts were not. Plants exposed in situ to pesticide-sprayed soils (inside a chamber receiving vapors from the soil) also showed significant increases in micronuclei frequency in relation to controls exposed to unsprayed soil. In general, there was no significant reduction in the genotoxic effects from the High to the Medium treatment levels of the IPM program. This suggests that the reduction in pesticide application rates attained with the implementation of the proposed IPM program was not sufficient to abate the genotoxicity of the pesticides, as perceived with the sensitive assays employed. The results indicate that replacing genotoxic compounds may be the only effective remediation measure to eliminate the risks imposed by mutagenic compounds in the agricultural environment.

Heating-Rate-Triggered Carbon-Nanotube-based 3-Dimensional Conducting Networks for a Highly Sensitive Noncontact Sensing Device

PubMed Central

Tai, Yanlong; Lubineau, Gilles

2016-01-01

Recently, flexible and transparent conductive films (TCFs) are drawing more attention for their central role in future applications of flexible electronics. Here, we report the controllable fabrication of TCFs for moisture-sensing applications based on heating-rate-triggered, 3-dimensional porous conducting networks through drop casting lithography of single-walled carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) ink. How ink formula and baking conditions influence the self-assembled microstructure of the TCFs is discussed. The sensor presents high-performance properties, including a reasonable sheet resistance (2.1 kohm/sq), a high visible-range transmittance (>69%, PET = 90%), and good stability when subjected to cyclic loading (>1000 cycles, better than indium tin oxide film) during processing, when formulation parameters are well optimized (weight ratio of SWCNT to PEDOT:PSS: 1:0.5, SWCNT concentration: 0.3 mg/ml, and heating rate: 36 °C/minute). Moreover, the benefits of these kinds of TCFs were verified through a fully transparent, highly sensitive, rapid response, noncontact moisture-sensing device (5 × 5 sensing pixels). PMID:26818091

Identifying critical nitrogen application rate for maize yield and nitrate leaching in a Haplic Luvisol soil using the DNDC model.

PubMed

Zhang, Yitao; Wang, Hongyuan; Liu, Shen; Lei, Qiuliang; Liu, Jian; He, Jianqiang; Zhai, Limei; Ren, Tianzhi; Liu, Hongbin

2015-05-01

Identification of critical nitrogen (N) application rate can provide management supports for ensuring grain yield and reducing amount of nitrate leaching to ground water. A five-year (2008-2012) field lysimeter (1 m × 2 m × 1.2 m) experiment with three N treatments (0, 180 and 240 kg Nha(-1)) was conducted to quantify maize yields and amount of nitrate leaching from a Haplic Luvisol soil in the North China Plain. The experimental data were used to calibrate and validate the process-based model of Denitrification-Decomposition (DNDC). After this, the model was used to simulate maize yield production and amount of nitrate leaching under a series of N application rates and to identify critical N application rate based on acceptable yield and amount of nitrate leaching for this cropping system. The results of model calibration and validation indicated that the model could correctly simulate maize yield and amount of nitrate leaching, with satisfactory values of RMSE-observation standard deviation ratio, model efficiency and determination coefficient. The model simulations confirmed the measurements that N application increased maize yield compared with the control, but the high N rate (240 kg Nha(-1)) did not produce more yield than the low one (120 kg Nha(-1)), and that the amount of nitrate leaching increased with increasing N application rate. The simulation results suggested that the optimal N application rate was in a range between 150 and 240 kg ha(-1), which would keep the amount of nitrate leaching below 18.4 kg NO₃(-)-Nha(-1) and meanwhile maintain acceptable maize yield above 9410 kg ha(-1). Furthermore, 180 kg Nha(-1) produced the highest yields (9837 kg ha(-1)) and comparatively lower amount of nitrate leaching (10.0 kg NO₃(-)-Nha(-1)). This study will provide a valuable reference for determining optimal N application rate (or range) in other crop systems and regions in China. Copyright © 2015 Elsevier B.V. All rights reserved.

Imidacloprid-treated seed ingestion has lethal effect on adult partridges and reduces both breeding investment and offspring immunity.

PubMed

Lopez-Antia, Ana; Ortiz-Santaliestra, Manuel E; Mougeot, François; Mateo, Rafael

2015-01-01

The ingestion of imidacloprid treated seeds by farmland birds may result in exposure to toxic amounts of this insecticide. Here we report on the effects that the exposure to the recommended application rate and to 20% of that rate may produce on birds feeding on treated seeds. Experimental exposure to imidacloprid treated seeds was performed on red-legged partridges (Alectoris rufa) (n=15 pairs per treatment group: control, 20% or 100% of the recommended application rate) during two periods that corresponded to the autumn (duration of exposure: 25 days) and late winter (10 days) cereal sowing times in Spanish farmlands. We studied effects on the survival, body condition, oxidative stress biomarkers, plasma biochemistry, carotenoid-based coloration, T-cell mediated immune response and reproduction of exposed adult partridges, and on the survival and T-cell immune response of their chicks. The high dose (recommended application rate) killed all partridges, with mortality occurring faster in females than in males. The low dose (20% the recommended application rate) had no effect on mortality, but reduced levels of plasma biochemistry parameters (glucose, magnesium and lactate dehydrogenase), increased blood superoxide dismutase activity, produced changes in carotenoid-based integument coloration, reduced the clutch size, delayed the first egg lay date, increased egg yolk vitamins and carotenoids and depressed T-cell immune response of chicks. Moreover, the analysis of the livers of dead partridges revealed an accumulation of imidacloprid during exposure time. Despite the moratorium on the use of neonicotinoids in the European Union, birds may still be at high risk of poisoning by these pesticides through direct sources of exposure to coated seeds in autumn and winter. Copyright © 2014 Elsevier Inc. All rights reserved.

WDM package enabling high-bandwidth optical intrasystem interconnects for high-performance computer systems

NASA Astrophysics Data System (ADS)

Schrage, J.; Soenmez, Y.; Happel, T.; Gubler, U.; Lukowicz, P.; Mrozynski, G.

2006-02-01

From long haul, metro access and intersystem links the trend goes to applying optical interconnection technology at increasingly shorter distances. Intrasystem interconnects such as data busses between microprocessors and memory blocks are still based on copper interconnects today. This causes a bottleneck in computer systems since the achievable bandwidth of electrical interconnects is limited through the underlying physical properties. Approaches to solve this problem by embedding optical multimode polymer waveguides into the board (electro-optical circuit board technology, EOCB) have been reported earlier. The principle feasibility of optical interconnection technology in chip-to-chip applications has been validated in a number of projects. For reasons of cost considerations waveguides with large cross sections are used in order to relax alignment requirements and to allow automatic placement and assembly without any active alignment of components necessary. On the other hand the bandwidth of these highly multimodal waveguides is restricted due to mode dispersion. The advance of WDM technology towards intrasystem applications will provide sufficiently high bandwidth which is required for future high-performance computer systems: Assuming that, for example, 8 wavelength-channels with 12Gbps (SDR1) each are given, then optical on-board interconnects with data rates a magnitude higher than the data rates of electrical interconnects for distances typically found at today's computer boards and backplanes can be realized. The data rate will be twice as much, if DDR2 technology is considered towards the optical signals as well. In this paper we discuss an approach for a hybrid integrated optoelectronic WDM package which might enable the application of WDM technology to EOCB.

Multifeature-based high-resolution palmprint recognition.

PubMed

Dai, Jifeng; Zhou, Jie

2011-05-01

Palmprint is a promising biometric feature for use in access control and forensic applications. Previous research on palmprint recognition mainly concentrates on low-resolution (about 100 ppi) palmprints. But for high-security applications (e.g., forensic usage), high-resolution palmprints (500 ppi or higher) are required from which more useful information can be extracted. In this paper, we propose a novel recognition algorithm for high-resolution palmprint. The main contributions of the proposed algorithm include the following: 1) use of multiple features, namely, minutiae, density, orientation, and principal lines, for palmprint recognition to significantly improve the matching performance of the conventional algorithm. 2) Design of a quality-based and adaptive orientation field estimation algorithm which performs better than the existing algorithm in case of regions with a large number of creases. 3) Use of a novel fusion scheme for an identification application which performs better than conventional fusion methods, e.g., weighted sum rule, SVMs, or Neyman-Pearson rule. Besides, we analyze the discriminative power of different feature combinations and find that density is very useful for palmprint recognition. Experimental results on the database containing 14,576 full palmprints show that the proposed algorithm has achieved a good performance. In the case of verification, the recognition system's False Rejection Rate (FRR) is 16 percent, which is 17 percent lower than the best existing algorithm at a False Acceptance Rate (FAR) of 10(-5), while in the identification experiment, the rank-1 live-scan partial palmprint recognition rate is improved from 82.0 to 91.7 percent.

Chemical engineering design of CO oxidation catalysts

NASA Technical Reports Server (NTRS)

Herz, Richard K.

1987-01-01

How a chemical reaction engineer would approach the challenge of designing a CO oxidation catalyst for pulsed CO2 lasers is described. CO oxidation catalysts have a long history of application, of course, so it is instructive to first consider the special requirements of the laser application and then to compare them to the characteristics of existing processes which utilize CO oxidation catalysts. All CO2 laser applications require a CO oxidation catalyst with the following characteristics: (1) active at stoichiometric ratios of O2 and CO, (2) no inhibition by CO2 or other components of the laser environment, (3) releases no particulates during vibration or thermal cycling, and (4) long lifetime with a stable activity. In all applications, low consumption of power is desirable, a characteristic especially critical in aerospace applications and, thus, catalyst activity at low temperatures is highly desirable. High power lasers with high pulse repetition rates inherently require circulation of the gas mixture and this forced circulation is available for moving gas past the catalyst. Low repetition rate lasers, however, do not inherently require gas circulation, so a catalyst that did not require such circulation would be favorable from the standpoint of minimum power consumption. Lasers designed for atmospheric penetration of their infrared radiation utilize CO2 formed from rare isotopes of oxygen and this application has the additional constraint that normal abundance oxygen isotopes in the catalyst must not exchange with rare isotopes in the gas mixture.

[Effects of nitrogen application rate on potassium uptake and utilization of direct-seeded cotton after wheat harvest].

PubMed

Zhang, Guo Wei; Yang, Chang Qin; Liu, Rui Xian; Zhang, Lei; Ni, Wan Chao

2016-10-01

By using cotton cultivar CCRI-50 as material, field experiments were conducted in the summer seasons of 2013 and 2014 at the experimental station of Jiangsu Academy of Agricultural Sciences (Nanjing, China) to study the effects of different nitrogen application rates (0, 60, 120, 150, 180 and 240 kg N·hm -2 ) on the potassium uptake and utilization of the cotton plant that was direct-seeded after wheat harvest. Data suggested that the elevated nitrogen application rates increased the cotton potassium uptake of all growth stages, and the largest increment was observed at the peak flowering-boll opening stage. Nitrogen application also changed the uptake percentage of potassium uptake of each stage, i.e., the percentage of potassium uptake decreased in the stage from seedling to peak flowering, while increased in the stage from peak flowering to boll maturing. In addition, the elevated nitrogen applications reduced the decreasing rate of nitrogen concentration in upper fruiting branches, but promoted the decreasing rate in middle and low fruiting branches at later growth stages. As the nitrogen application rate increased, the marginal effect of potassium uptake (promoted amount of potassium uptake due to 1 kg increase of N application) increased first and then decreased, and the lint production efficiency of potassium descended steadily. In cotton plants that were direct-seeded after wheat harvest, potassium and biomass were mainly accumulated in the lower and middle fruiting branches. At the 150 and 180 kg N·hm -2 application levels, much more potassium was allocated to the reproductive organs and the characters and the eigenvalues of simulated curves of potassium concentration and total potassium accumulation were more optimized than those at the higher or the lower N application levels. At the high nitrogen application (more than 180 kg N·hm -2 ) level, the marginal effect of potassium uptake and lint production efficiency decreased, and at the lower nitrogen application (less than 150 kg N·hm -2 ) level, lint yield was lower due to the decrease of economic coefficient of biomass and potassium in the middle and low fruiting branches.

Smart Construction of Integrated CNTs/Li4Ti5O12 Core/Shell Arrays with Superior High-Rate Performance for Application in Lithium-Ion Batteries.

PubMed

Yao, Zhujun; Xia, Xinhui; Zhou, Cheng-Ao; Zhong, Yu; Wang, Yadong; Deng, Shengjue; Wang, Weiqi; Wang, Xiuli; Tu, Jiangping

2018-03-01

Exploring advanced high-rate anodes is of great importance for the development of next-generation high-power lithium-ion batteries (LIBs). Here, novel carbon nanotubes (CNTs)/Li 4 Ti 5 O 12 (LTO) core/shell arrays on carbon cloth (CC) as integrated high-quality anode are constructed via a facile combined chemical vapor deposition-atomic layer deposition (ALD) method. ALD-synthesized LTO is strongly anchored on the CNTs' skeleton forming core/shell structures with diameters of 70-80 nm the combined advantages including highly conductive network, large surface area, and strong adhesion are obtained in the CC-LTO@CNTs core/shell arrays. The electrochemical performance of the CC-CNTs/LTO electrode is completely studied as the anode of LIBs and it shows noticeable high-rate capability (a capacity of 169 mA h g -1 at 1 C and 112 mA h g -1 at 20 C), as well as a stable cycle life with a capacity retention of 86% after 5000 cycles at 10 C, which is much better than the CC-LTO counterpart. Meanwhile, excellent cycling stability is also demonstrated for the full cell with LiFePO 4 cathode and CC-CNTs/LTO anode (87% capacity retention after 1500 cycles at 10 C). These positive features suggest their promising application in high-power energy storage areas.

Touching the theoretical capacity: synthesizing cubic LiTi2(PO4)3/C nanocomposites for high-performance lithium-ion battery.

PubMed

Deng, Wenjun; Wang, Xusheng; Liu, Chunyi; Li, Chang; Xue, Mianqi; Li, Rui; Pan, Feng

2018-04-05

A cubic LiTi2(PO4)3/C composite is successfully prepared via a simple solvothermal method and further glucose-pyrolysis treatment. The as-fabricated LTP/C material delivers an ultra-high reversible capacity of 144 mA h g-1 at 0.2C rate, which is the highest ever reported, and shows considerable performance improvement compared with before. Combining this with the stable cycling performance and high rate capability, such material has a promising future in practical application.

A High Resolution Scale-of-four

DOE R&D Accomplishments Database

Fitch, V.

1949-08-25

A high resolution scale-of-four has been developed to be used in conjunction with the nuclear particle detection devices in applications where the counting rate is unusually high. Specifically, it is intended to precede the commercially available medium resolution scaling circuits and so decrease the resolving time of the counting system. The circuit will function reliably on continuously recurring pulses separated by less than 0.1 microseconds. It will resolve two pulses (occurring at a moderate repetition rate) which are spaced at 0.04 microseconds. A five-volt input signal is sufficient to actuate the device.

[Application of spontaneous acrosome reaction of sperm in prediction of outcome of in-vitro fertilization and embryo transfer].

PubMed

Xuan, X J; Xu, C; Zhao, Y R; Wu, K L; Chen, T; Zhang, H B; Li, X; Su, S Z; Ma, G; Tang, R; Sheng, Y; Ma, J L

2016-04-26

To investigate the clinical application of spontaneous acrosome reaction (AR) rate of sperm in predicting the outcome of in-vitro fertilization and embryo transfer (IVF-ET). The spontaneous AR rate of the sperm of patients who underwent IVF-ET treatment in our center during the period from November to December 2014 were studied. The cut-off value from 6% to 12% were set and analyzed its association between the IVF-ET outcomes (including fertility rates, normal fertilization rates and high-quality embryo rates). For those who underwent fresh embryo transplantation, the rates of chemical pregnancy and clinical pregnancy were calculated, and compared the spontaneous AR rates and quantity of acrosomal enzyme according to the pregnancy outcome. There were 202 patients in this study and the mean spontaneous AR rate was 5.99%±5.18%. For patients with the spontaneous AR rate ≥9% versus <9%, the fertility rate, normal fertilization rate and high-quality embryo rate were 81.33% vs 83.85%, 60.53% vs 60.99%, and 51.10% vs 59.67%, respectively, with statistically significant difference in the high-quality embryo rate (P=0.02). For patients who underwent fresh embryo transplantation, when comparison was made between those with spontaneous AR rate ≥8% and those <8%, the rate of chemical pregnancy and clinical pregnancy were 48.57% (17/35) vs 69.64% (78/112) and 37.14% (13/35) vs 63.39% (71/112), respectively, both with statistically significant difference (P=0.02 and P<0.01). The patients with clinical pregnancy had lower spontaneous AR rate than those without clinical pregnancy (5.41%±3.87% vs 7.40%±6.79%, P=0.04), while the quantity of acrosomal enzyme showed no significant difference [(131.79±68.50) vs (153.62±59.59) μU/10(6,) P=0.06]. Logistic regression analysis demonstrated association between spontaneous AR rates and clinical pregnancy (OR=0.93, 95%CI: 0.87-0.99, P=0.03). The spontaneous AR rate of sperm may have clinical significance in predicting the outcome of IVF-ET, as it is reversely correlated with IVF high-quality embryo rate and pregnancy rate. The quantity of acrosomal enzyme may not have significant predictive value for the outcome of IVF.

Ammonia volatilization following dairy slurry application to a permanent grassland on a volcanic soil

NASA Astrophysics Data System (ADS)

Martínez-Lagos, J.; Salazar, F.; Alfaro, M.; Misselbrook, T.

2013-12-01

Agriculture is the largest source of ammonia (NH3) emission to the atmosphere. Within the agricultural sector, the application of slurry to grasslands as fertilizer is one of the main emission sources. This is a common practice in southern Chile, where most dairy production systems are grazing-based. In Chile, there are few published data of gaseous emissions following slurry application to grassland. The aim of this study was to evaluate NH3 volatilization following dairy slurry application to a permanent grassland on an Andosol soil. Ammonia volatilization was measured in four field experiments (winters of 2009 and 2011 and early and late springs of 2011) using a micrometeorological mass balance method with passive flux samplers following dairy slurry application at a target rate of 100 kg total N ha-1. The accumulated N loss was equivalent to 7, 8, 16 and 21% of the total N applied and 22, 34, 88 and 74% of total ammoniacal nitrogen (TAN) applied for winters 2009 and 2011, and early and late spring 2011, respectively. Ammonia emission rates were high immediately after application and declined rapidly with time, with more than 50% of the total emissions within the first 24 h. Losses were highly influenced by environmental conditions, increasing with temperature and lack of rainfall. Taking into consideration the low N losses via leaching and nitrous oxide emissions reported for the study area, results indicate that NH3 volatilization is the main pathway of N loss in fertilized grasslands of southern Chile. However, dairy slurry application could be an important source of nutrients, if applied at a suitable time, rate and using an appropriate technique, and if soil and climate conditions are taken into consideration. This could improve N use efficiency and reduce N losses to the wider environment.

Slic Superpixels for Object Delineation from Uav Data

NASA Astrophysics Data System (ADS)

Crommelinck, S.; Bennett, R.; Gerke, M.; Koeva, M. N.; Yang, M. Y.; Vosselman, G.

2017-08-01

Unmanned aerial vehicles (UAV) are increasingly investigated with regard to their potential to create and update (cadastral) maps. UAVs provide a flexible and low-cost platform for high-resolution data, from which object outlines can be accurately delineated. This delineation could be automated with image analysis methods to improve existing mapping procedures that are cost, time and labor intensive and of little reproducibility. This study investigates a superpixel approach, namely simple linear iterative clustering (SLIC), in terms of its applicability to UAV data. The approach is investigated in terms of its applicability to high-resolution UAV orthoimages and in terms of its ability to delineate object outlines of roads and roofs. Results show that the approach is applicable to UAV orthoimages of 0.05 m GSD and extents of 100 million and 400 million pixels. Further, the approach delineates the objects with the high accuracy provided by the UAV orthoimages at completeness rates of up to 64 %. The approach is not suitable as a standalone approach for object delineation. However, it shows high potential for a combination with further methods that delineate objects at higher correctness rates in exchange of a lower localization quality. This study provides a basis for future work that will focus on the incorporation of multiple methods for an interactive, comprehensive and accurate object delineation from UAV data. This aims to support numerous application fields such as topographic and cadastral mapping.

Dose-rate effect of ultrashort electron beam radiation on DNA damage and repair in vitro.

PubMed

Babayan, Nelly; Hovhannisyan, Galina; Grigoryan, Bagrat; Grigoryan, Ruzanna; Sarkisyan, Natalia; Tsakanova, Gohar; Haroutiunian, Samvel; Aroutiounian, Rouben

2017-11-01

Laser-generated electron beams are distinguished from conventional accelerated particles by ultrashort beam pulses in the femtoseconds to picoseconds duration range, and their application may elucidate primary radiobiological effects. The aim of the present study was to determine the dose-rate effect of laser-generated ultrashort pulses of 4 MeV electron beam radiation on DNA damage and repair in human cells. The dose rate was increased via changing the pulse repetition frequency, without increasing the electron energy. The human chronic myeloid leukemia K-562 cell line was used to estimate the DNA damage and repair after irradiation, via the comet assay. A distribution analysis of the DNA damage was performed. The same mean level of initial DNA damages was observed at low (3.6 Gy/min) and high (36 Gy/min) dose-rate irradiation. In the case of low-dose-rate irradiation, the detected DNA damages were completely repairable, whereas the high-dose-rate irradiation demonstrated a lower level of reparability. The distribution analysis of initial DNA damages after high-dose-rate irradiation revealed a shift towards higher amounts of damage and a broadening in distribution. Thus, increasing the dose rate via changing the pulse frequency of ultrafast electrons leads to an increase in the complexity of DNA damages, with a consequent decrease in their reparability. Since the application of an ultrashort pulsed electron beam permits us to describe the primary radiobiological effects, it can be assumed that the observed dose-rate effect on DNA damage/repair is mainly caused by primary lesions appearing at the moment of irradiation. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

High-average-power 2 μm few-cycle optical parametric chirped pulse amplifier at 100 kHz repetition rate.

PubMed

Shamir, Yariv; Rothhardt, Jan; Hädrich, Steffen; Demmler, Stefan; Tschernajew, Maxim; Limpert, Jens; Tünnermann, Andreas

2015-12-01

Sources of long wavelengths few-cycle high repetition rate pulses are becoming increasingly important for a plethora of applications, e.g., in high-field physics. Here, we report on the realization of a tunable optical parametric chirped pulse amplifier at 100 kHz repetition rate. At a central wavelength of 2 μm, the system delivered 33 fs pulses and a 6 W average power corresponding to 60 μJ pulse energy with gigawatt-level peak powers. Idler absorption and its crystal heating is experimentally investigated for a BBO. Strategies for further power scaling to several tens of watts of average power are discussed.

A Spread-Spectrum SQUID Multiplexer

NASA Astrophysics Data System (ADS)

Irwin, K. D.; Chaudhuri, S.; Cho, H.-M.; Dawson, C.; Kuenstner, S.; Li, D.; Titus, C. J.; Young, B. A.

2018-06-01

The transition-edge sensor (TES) is a mature, high-resolution x-ray spectrometer technology that provides a much higher efficiency than dispersive spectrometers such as gratings and crystal spectrometers. As larger arrays are developed, time-division multiplexing schemes operating at MHz frequencies are being replaced by microwave SQUID multiplexers using frequency-division multiplexing at GHz frequencies. However, the multiplexing factor achievable with microwave SQUIDs is limited by the high slew rate on the leading edge of x-ray pulses. In this paper, we propose a new multiplexing scheme for high-slew-rate TES x-ray calorimeters: the spread-spectrum SQUID multiplexer, which has the potential to enable higher multiplexing factors, especially in applications with lower photon-arrival rates.

Learning Programming Technique through Visual Programming Application as Learning Media with Fuzzy Rating

ERIC Educational Resources Information Center

Buditjahjanto, I. G. P. Asto; Nurlaela, Luthfiyah; Ekohariadi; Riduwan, Mochamad

2017-01-01

Programming technique is one of the subjects at Vocational High School in Indonesia. This subject contains theory and application of programming utilizing Visual Programming. Students experience some difficulties to learn textual learning. Therefore, it is necessary to develop media as a tool to transfer learning materials. The objectives of this…

Evaluation of semiconductor devices for Electric and Hybrid Vehicle (EHV) ac-drive applications, volume 1

NASA Technical Reports Server (NTRS)

Lee, F. C.; Chen, D. Y.; Jovanovic, M.; Hopkins, D. C.

1985-01-01

The results of evaluation of power semiconductor devices for electric hybrid vehicle ac drive applications are summarized. Three types of power devices are evaluated in the effort: high power bipolar or Darlington transistors, power MOSFETs, and asymmetric silicon control rectifiers (ASCR). The Bipolar transistors, including discrete device and Darlington devices, range from 100 A to 400 A and from 400 V to 900 V. These devices are currently used as key switching elements inverters for ac motor drive applications. Power MOSFETs, on the other hand, are much smaller in current rating. For the 400 V device, the current rating is limited to 25 A. For the main drive of an electric vehicle, device paralleling is normally needed to achieve practical power level. For other electric vehicle (EV) related applications such as battery charger circuit, however, MOSFET is advantageous to other devices because of drive circuit simplicity and high frequency capability. Asymmetrical SCR is basically a SCR device and needs commutation circuit for turn off. However, the device poses several advantages, i.e., low conduction drop and low cost.

Enabling technology for future gigabit-symmetric FTTH: coherent OCDMA over WDM-PON

NASA Astrophysics Data System (ADS)

Kitayama, Ken-ichi; Wang, Xu; Wada, Naoya

2006-09-01

For the future broadband Fiber-To-The-Home (FTTH) services, it will be revealed to be a myth that the low bit-rate uplink may be deployed, while only the downlink has to be high bit-rate. Current FTTH system forces the customers a stressful access in the uplink due to its MAC based on TDMA under always-on service provisionings. Without an abundant bandwidth of uplink available, peer-to-peer applications such as exchanging gigabyte files of uncompressed 1.2 Gbps high-definition (HD) TV class or even 6Gbps super-high-definition (SHD)class digital movies as well as teleconferencing and bi-directional medical applications such as tele-diagnosis and -surgery won't become widewpread. With a narrowband uplink, even non peer-to-peer customers will be put in a disadvantageous position by being forced to share the limited bandwidth with a limited number of bandwidth-hungry users.

Development and Application of a High Throughput Protein Unfolding Kinetic Assay

PubMed Central

Wang, Qiang; Waterhouse, Nicklas; Feyijinmi, Olusegun; Dominguez, Matthew J.; Martinez, Lisa M.; Sharp, Zoey; Service, Rachel; Bothe, Jameson R.; Stollar, Elliott J.

2016-01-01

The kinetics of folding and unfolding underlie protein stability and quantification of these rates provides important insights into the folding process. Here, we present a simple high throughput protein unfolding kinetic assay using a plate reader that is applicable to the studies of the majority of 2-state folding proteins. We validate the assay by measuring kinetic unfolding data for the SH3 (Src Homology 3) domain from Actin Binding Protein 1 (AbpSH3) and its stabilized mutants. The results of our approach are in excellent agreement with published values. We further combine our kinetic assay with a plate reader equilibrium assay, to obtain indirect estimates of folding rates and use these approaches to characterize an AbpSH3-peptide hybrid. Our high throughput protein unfolding kinetic assays allow accurate screening of libraries of mutants by providing both kinetic and equilibrium measurements and provide a means for in-depth ϕ-value analyses. PMID:26745729

Effects of high-rate wastewater spray disposal on the water-table aquifer, Hilton Head Island, South Carolina

USGS Publications Warehouse

Speiran, G.K.

1985-01-01

A study by the U.S. Geological Survey from April 1982 through December 1983 evaluated the effects of high-rate disposal of treated wastewater on the water table aquifer, Hilton Head Island, South Carolina. Flooding of topographically low areas resulted from the application of 10.8 inches of wastewater in 10 days in January 1983. The water table remained 2-1/2 to 5-1/2 feet below land surface when wastewater was applied at rates of 5 inches per week in August and December 1983. (USGS)

Hydrocarbons from spirulina pyrolysis bio-oil using one-step hydrotreating and aqueous extraction of heteroatom compounds

USDA-ARS?s Scientific Manuscript database

Biomass feedstocks such as algae and cyanobacteria are highly sought after due to their high reproduction rates and growth densities, but their high concentrations of O and N heteroatoms are problematic for biofuels applications. The development of mild upgrading processes is necessary for producing...

Accelerated Degradation Behavior and Cytocompatibility of Pure Iron Treated with Sandblasting.

PubMed

Zhou, Juncen; Yang, Yuyun; Alonso Frank, Micael; Detsch, Rainer; Boccaccini, Aldo R; Virtanen, Sannakaisa

2016-10-12

Fe-based materials are of interest for use in biodegradable implants. However, their corrosion rate in the biological environment may be too slow for the targeted applications. In this work, sandblasting is applied as a successful surface treatment for increasing the degradation rate of pure iron in simulated body fluid. Two sandblasting surfaces with different roughness present various surface morphologies but similar degradation products. Electrochemistry tests revealed that sandblasted samples have a higher corrosion rate compared to that of bare iron, and even more noteworthy, the degradation rate of sandblasted samples remains significantly higher during long-term immersion tests. On the basis of our experimental results, the most plausible reasons behind the fast degradation rate are the special properties of sandblasted surfaces, including the change of surface composition (for the early stage), high roughness (occluded surface sites), and high density of dislocations. Furthermore, the cytocompatibility was studied on sandblasting surfaces using human osteoblast-like cells (MG-63) by indirect and direct contact methods. Results revealed that sandblasting treatment brings no adverse effect to the growth of MG-63 cells. This work demonstrates the significant potential of sandblasting for controlling the degradation behavior of iron-based materials for biomedical applications.

Early effects comparison of X-rays delivered at high-dose-rate pulses by a plasma focus device and at low dose rate on human tumour cells.

PubMed

Virelli, A; Zironi, I; Pasi, F; Ceccolini, E; Nano, R; Facoetti, A; Gavoçi, E; Fiore, M R; Rocchi, F; Mostacci, D; Cucchi, G; Castellani, G; Sumini, M; Orecchia, R

2015-09-01

A comparative study has been performed on the effects of high-dose-rate (DR) X-ray beams produced by a plasma focus device (PFMA-3), to exploit its potential medical applications (e.g. radiotherapy), and low-DR X-ray beams produced by a conventional source (XRT). Experiments have been performed at 0.5 and 2 Gy doses on a human glioblastoma cell line (T98G). Cell proliferation rate and potassium outward currents (IK) have been investigated by time lapse imaging and patch clamp recordings. The results showed that PFMA-3 irradiation has a greater capability to reduce the proliferation rate activity with respect to XRT, while it does not affect IK of T98G cells at any of the dose levels tested. XRT irradiation significantly reduces the mean IK amplitude of T98G cells only at 0.5 Gy. This work confirms that the DR, and therefore the source of radiation, is crucial for the planning and optimisation of radiotherapy applications. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Modeling of Sheath Ion-Molecule Reactions in Plasma Enhanced Chemical Vapor Deposition of Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Hash, David B.; Govindan, T. R.; Meyyappan, M.

2004-01-01

In many plasma simulations, ion-molecule reactions are modeled using ion energy independent reaction rate coefficients that are taken from low temperature selected-ion flow tube experiments. Only exothermic or nearly thermoneutral reactions are considered. This is appropriate for plasma applications such as high-density plasma sources in which sheaths are collisionless and ion temperatures 111 the bulk p!asma do not deviate significantly from the gas temperature. However, for applications at high pressure and large sheath voltages, this assumption does not hold as the sheaths are collisional and ions gain significant energy in the sheaths from Joule heating. Ion temperatures and thus reaction rates vary significantly across the discharge, and endothermic reactions become important in the sheaths. One such application is plasma enhanced chemical vapor deposition of carbon nanotubes in which dc discharges are struck at pressures between 1-20 Torr with applied voltages in the range of 500-700 V. The present work investigates The importance of the inclusion of ion energy dependent ion-molecule reaction rates and the role of collision induced dissociation in generating radicals from the feedstock used in carbon nanotube growth.

Advanced dendritic web growth development

NASA Technical Reports Server (NTRS)

Hopkins, R. H.

1985-01-01

A program to develop the technology of the silicon dendritic web ribbon growth process is examined. The effort is being concentrated on the area rate and quality requirements necessary to meet the JPL/DOE goals for terrestrial PV applications. Closed loop web growth system development and stress reduction for high area rate growth is considered.

75 FR 19495 - Overview Information; Race to the Top Fund; Notice Inviting Applications for New Awards for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-14

... graduation rates, and ensuring student preparation for success in college and careers; and implementing... assessments that prepare students for success in college and the workplace; (b) Building data systems that... rates at which students graduate from high school prepared for college and careers. Competitive...

Six Habits of the Highly Effective E-Rate Applicant

ERIC Educational Resources Information Center

Harrington, John

2011-01-01

Since its inception in 1997, the Schools and Libraries Program of the Federal Communications Commission's Universal Service Fund, more commonly known as E-Rate, has committed more than $30 billion to offset the cost of certain digital and telecommunication services and products that are essential for schools and libraries to receive…

Efficient high repetition rate electro-optic Q-switched laser with an optically active langasite crystal

PubMed Central

Ma, Shihui; Yu, Haohai; Zhang, Huaijin; Han, Xuekun; Lu, Qingming; Ma, Changqin; Boughton, Robert I.; Wang, Jiyang

2016-01-01

With an optically active langasite (LGS) crystal as the electro-optic Q-switch, we demonstrate an efficient Q-switched laser with a repetition rate of 200 kHz. Based on the theoretical analysis of the interaction between optical activity and electro-optic property, the optical activity of the crystal has no influence on the birefringence during Q-switching if the quarter wave plate used was rotated to align with the polarization direction. With a Nd:LuVO4 crystal possessing a large emission cross-section and a short fluorescence lifetime as the gain medium, a stable LGS Q-switched laser was designed with average output power of 4.39 W, corresponding to a slope efficiency of 29.4% and with a minimum pulse width of 5.1 ns. This work represents the highest repetition rate achieved so far in a LGS Q-switched laser and it can provide a practical Q-switched laser with a tunable high repetition rates for many applications, such as materials processing, laser ranging, medicine, military applications, biomacromolecule materials, remote sensing, etc. PMID:27461819

Kinetics of enzymatic high-solid hydrolysis of lignocellulosic biomass studied by calorimetry.

PubMed

Olsen, Søren N; Lumby, Erik; McFarland, Kc; Borch, Kim; Westh, Peter

2011-03-01

Enzymatic hydrolysis of high-solid biomass (>10% w/w dry mass) has become increasingly important as a key step in the production of second-generation bioethanol. To this end, development of quantitative real-time assays is desirable both for empirical optimization and for detailed kinetic analysis. In the current work, we have investigated the application of isothermal calorimetry to study the kinetics of enzymatic hydrolysis of two substrates (pretreated corn stover and Avicel) at high-solid contents (up to 29% w/w). It was found that the calorimetric heat flow provided a true measure of the hydrolysis rate with a detection limit of about 500 pmol glucose s(-1). Hence, calorimetry is shown to be a highly sensitive real-time method, applicable for high solids, and independent on the complexity of the substrate. Dose-response experiments with a typical cellulase cocktail enabled a multidimensional analysis of the interrelationships of enzyme load and the rate, time, and extent of the reaction. The results suggest that the hydrolysis rate of pretreated corn stover is limited initially by available attack points on the substrate surface (<10% conversion) but becomes proportional to enzyme dosage (excess of attack points) at later stages (>10% conversion). This kinetic profile is interpreted as an increase in polymer end concentration (substrate for CBH) as the hydrolysis progresses, probably due to EG activity in the enzyme cocktail. Finally, irreversible enzyme inactivation did not appear to be the source of reduced hydrolysis rate over time.

Respiration-rate estimation of a moving target using impulse-based ultra wideband radars.

PubMed

Sharafi, Azadeh; Baboli, Mehran; Eshghi, Mohammad; Ahmadian, Alireza

2012-03-01

Recently, Ultra-wide band signals have become attractive for their particular advantage of having high spatial resolution and good penetration ability which makes them suitable in medical applications. One of these applications is wireless detection of heart rate and respiration rate. Two hypothesis of static environment and fixed patient are considered in the method presented in previous literatures which are not valid for long term monitoring of ambulant patients. In this article, a new method to detect the respiration rate of a moving target is presented. The first algorithm is applied to the simulated and experimental data for detecting respiration rate of a fixed target. Then, the second algorithm is developed to detect respiration rate of a moving target. The proposed algorithm uses correlation for body movement cancellation, and then detects the respiration rate based on energy in frequency domain. The results of algorithm prove an accuracy of 98.4 and 97% in simulated and experimental data, respectively.

Parallel digital modem using multirate digital filter banks

NASA Technical Reports Server (NTRS)

Sadr, Ramin; Vaidyanathan, P. P.; Raphaeli, Dan; Hinedi, Sami

1994-01-01

A new class of architectures for an all-digital modem is presented in this report. This architecture, referred to as the parallel receiver (PRX), is based on employing multirate digital filter banks (DFB's) to demodulate, track, and detect the received symbol stream. The resulting architecture is derived, and specifications are outlined for designing the DFB for the PRX. The key feature of this approach is a lower processing rate then either the Nyquist rate or the symbol rate, without any degradation in the symbol error rate. Due to the freedom in choosing the processing rate, the designer is able to arbitrarily select and use digital components, independent of the speed of the integrated circuit technology. PRX architecture is particularly suited for high data rate applications, and due to the modular structure of the parallel signal path, expansion to even higher data rates is accommodated with each. Applications of the PRX would include gigabit satellite channels, multiple spacecraft, optical links, interactive cable-TV, telemedicine, code division multiple access (CDMA) communications, and others.

High frequency optical communications; Proceedings of the Meeting, Cambridge, MA, Sept. 23, 24, 1986

NASA Astrophysics Data System (ADS)

Ramer, O. Glenn; Sierak, Paul

Topics discussed in this volume include systems and applications, detectors, sources, and coherent communications. Papers are presented on RF fiber optic links for avionics applications, fiber optics and optoelectronics for radar and electronic warfare applications, symmetric coplanar electrodes for high-speed Ti:LiNbO3 devices, and surface wave electrooptic modulator. Attention is given to X-band RF fiber-optic links, fiber-optic links for microwave signal transmission, GaAs monolithic receiver and laser driver for GHz transmission rates, and monolithically integrable high-speed photodetectors. Additional papers are on irregular and chaotic behavior of semiconductor lasers under modulation, high-frequency laser package for microwave optical communications, receiver modeling for coherent light wave communications, and polarization sensors and controllers for coherent optical communication systems.

The evaluation of dentinal tubule occlusion by desensitizing agents: a real-time measurement of dentinal fluid flow rate and scanning electron microscopy.

PubMed

Kim, S Y; Kim, E J; Kim, D S; Lee, I B

2013-01-01

The aims of this study were to examine changes in dentinal fluid flow (DFF) during the application of a desensitizing agent and to compare the permeability reduction levels among different types of desensitizing agents. A cervical cavity was prepared for the exposure of cervical dentin on an extracted human premolar connected to a subnanoliter fluid flow measuring device under 20 cm of water pressure. The cavity was acid-etched with 32% phosphoric acid to make dentin highly permeable. The different types of desensitizing agents that were applied on the cavity were Seal&Protect as the light-curing adhesive type, SuperSeal and BisBlock as oxalate types, Gluma Desensitizer as the protein-precipitation type, and Bi-Fluoride 12 as the fluoride type. DFF was measured from the time before the application of the desensitizing agent throughout the application procedure to five minutes after the application. The characteristics of dentinal tubule occlusion of each desensitizing agent were examined by scanning electron microscopy. The DFF rate after each desensitizing agent application was significantly reduced when compared to the initial DFF rate before application for all of the desensitizing agents (p<0.05). Seal&Protect showed a greater reduction in the DFF rate when compared to Gluma Desensitizer and Bi-Fluoride 12 (p<0.05). SuperSeal and BisBlock exhibited a greater reduction in DFF rate when compared to Bi-Fluoride 12 (p<0.05). The dentin hypersensitivity treatment effects of the employed desensitizing agents in this study were confirmed through real-time measurements of DFF changes. The light-curing adhesive and oxalate types showed greater reduction in the DFF rate than did the protein-precipitation and fluoride types.

National Utility Rate Database: Preprint

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

Ong, S.; McKeel, R.

2012-08-01

When modeling solar energy technologies and other distributed energy systems, using high-quality expansive electricity rates is essential. The National Renewable Energy Laboratory (NREL) developed a utility rate platform for entering, storing, updating, and accessing a large collection of utility rates from around the United States. This utility rate platform lives on the Open Energy Information (OpenEI) website, OpenEI.org, allowing the data to be programmatically accessed from a web browser, using an application programming interface (API). The semantic-based utility rate platform currently has record of 1,885 utility rates and covers over 85% of the electricity consumption in the United States.

SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

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

Zhou, Y; Tan, J; Jiang, S

Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specifiedmore » treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.« less

Improved Performance of Ionic Liquid Supercapacitors by using Tetracyanoborate Anions.

PubMed

Martins, Vitor L; Rennie, Anthony J R; Sanchez-Ramirez, Nedher; Torresi, Roberto M; Hall, Peter J

2018-02-01

Supercapacitors are energy storage devices designed to operate at higher power densities than conventional batteries, but their energy density is still too low for many applications. Efforts are made to design new electrolytes with wider electrochemical windows than aqueous or conventional organic electrolytes in order to increase energy density. Ionic liquids (ILs) with wide electrochemical stability windows are excellent candidates to be employed as supercapacitor electrolytes. ILs containing tetracyanoborate anions [B(CN) 4 ] offer wider electrochemical stability than conventional electrolytes and maintain a high ionic conductivity (6.9 mS cm -1 ). Herein, we report the use of ILs containing the [B(CN) 4 ] anion for such an application. They presented a high maximum operating voltage of 3.7 V, and two-electrode devices demonstrate high specific capacitances even when operating at relatively high rates (ca. 20 F g -1 @ 15 A g -1 ). This supercapacitor stored more energy and operated at a higher power at all rates studied when compared with cells using a commonly studied ILs.

High rate and stable cycling of lithium metal anode

PubMed Central

Qian, Jiangfeng; Henderson, Wesley A.; Xu, Wu; Bhattacharya, Priyanka; Engelhard, Mark; Borodin, Oleg; Zhang, Ji-Guang

2015-01-01

Lithium metal is an ideal battery anode. However, dendrite growth and limited Coulombic efficiency during cycling have prevented its practical application in rechargeable batteries. Herein, we report that the use of highly concentrated electrolytes composed of ether solvents and the lithium bis(fluorosulfonyl)imide salt enables the high-rate cycling of a lithium metal anode at high Coulombic efficiency (up to 99.1%) without dendrite growth. With 4 M lithium bis(fluorosulfonyl)imide in 1,2-dimethoxyethane as the electrolyte, a lithium|lithium cell can be cycled at 10 mA cm−2 for more than 6,000 cycles, and a copper|lithium cell can be cycled at 4 mA cm−2 for more than 1,000 cycles with an average Coulombic efficiency of 98.4%. These excellent performances can be attributed to the increased solvent coordination and increased availability of lithium ion concentration in the electrolyte. Further development of this electrolyte may enable practical applications for lithium metal anode in rechargeable batteries. PMID:25698340

Fabrication of thickness controllable free-standing sandwich-structured hybrid carbon film for high-rate and high-power supercapacitor

PubMed Central

Wei, Helin; Wei, Sihang; Tian, Weifeng; Zhu, Daming; Liu, Yuhao; Yuan, Lili; Li, Xin

2014-01-01

Hybrid carbon films composed of graphene film and porous carbon film may give full play to the advantages of both carbon materials, and have great potential for application in energy storage and conversion devices. Unfortunately, there are very few reports on fabrication of hybrid carbon films. Here we demonstrate a simple approach to fabricate free-standing sandwich-structured hybrid carbon film composed of porous amorphous carbon film and multilayer graphene film by chemical vapor deposition in a controllable and scalable way. Hybrid carbon films reveal good electrical conductivity, excellent flexibility, and good compatibility with substrate. Supercapacitors assembled by hybrid carbon films exhibit ultrahigh rate capability, wide frequency range, good capacitance performance, and high-power density. Moreover, this approach may provide a general path for fabrication of hybrid carbon materials with different structures by using different metals with high carbon solubility, and greatly expands the application scope of carbon materials. PMID:25394410

Chapter 17 Sterile Plate-Based Vitrification of Adherent Human Pluripotent Stem Cells and Their Derivatives Using the TWIST Method.

PubMed

Neubauer, Julia C; Stracke, Frank; Zimmermann, Heiko

2017-01-01

Due to their high biological complexity, e.g., their close cell-to-cell contacts, cryopreservation of human pluripotent stem cells with standard slow-rate protocols often is inefficient and can hardly be standardized. Vitrification that means ultrafast freezing already showed very good viability and recovery rates for this sensitive cell system, but is only applicable for low cell numbers, bears a high risk of contamination, and can hardly be implemented under GxP regulations. In this chapter, a sterile plate-based vitrification method for adherent pluripotent stem cells and their derivatives is presented based on a procedure and device for human embryonic stem cells developed by Beier et al. (Cryobiology 66:8-16, 2013). This protocol overcomes the limitations of conventional vitrification procedures resulting in the highly efficient preservation of ready-to-use adherent pluripotent stem cells with the possibility of vitrifying cells in multi-well formats for direct application in high-throughput screenings.

Multinode acoustic focusing for parallel flow cytometry

PubMed Central

Piyasena, Menake E.; Suthanthiraraj, Pearlson P. Austin; Applegate, Robert W.; Goumas, Andrew M.; Woods, Travis A.; López, Gabriel P.; Graves, Steven W.

2012-01-01

Flow cytometry can simultaneously measure and analyze multiple properties of single cells or particles with high sensitivity and precision. Yet, conventional flow cytometers have fundamental limitations with regards to analyzing particles larger than about 70 microns, analyzing at flow rates greater than a few hundred microliters per minute, and providing analysis rates greater than 50,000 per second. To overcome these limits, we have developed multi-node acoustic focusing flow cells that can position particles (as small as a red blood cell and as large as 107 microns in diameter) into as many as 37 parallel flow streams. We demonstrate the potential of such flow cells for the development of high throughput, parallel flow cytometers by precision focusing of flow cytometry alignment microspheres, red blood cells, and the analysis of CD4+ cellular immunophenotyping assay. This approach will have significant impact towards the creation of high throughput flow cytometers for rare cell detection applications (e.g. circulating tumor cells), applications requiring large particle analysis, and high volume flow cytometry. PMID:22239072

Accelerated GaAs growth through MOVPE for low-cost PV applications

NASA Astrophysics Data System (ADS)

Ubukata, Akinori; Sodabanlu, Hassanet; Watanabe, Kentaroh; Koseki, Shuichi; Yano, Yoshiki; Tabuchi, Toshiya; Sugaya, Takeyoshi; Matsumoto, Koh; Nakano, Yoshiaki; Sugiyama, Masakazu

2018-05-01

The high growth rate of epitaxial GaAs was investigated using a novel horizontal metalorganic vapor phase epitaxy (MOVPE) reactor, from the point of view of realizing low-cost photovoltaic (PV) solar cells. The GaAs growth rate exhibited an approximately linear relationship with the amount of trimethylgalium (TMGa) supplied, up to a rate of 90 μm/h. The distribution of growth rate was observed for a two-inch wafer, along the flow direction, and the normalized profile of the distribution was found to be independent of the precursor input, from 20 to 70 μm/h. These tendencies indicated that significant parasitic prereaction did not occur in the gaseous phase, for this range of growth rate. GaAs p-n single-junction solar cells were successfully fabricated at growth rates of 20, 60, and 80 μm/h. The conversion efficiency of the cell grown at 80 μm/h was comparable to that of the 20 μm/h cell, indicating the good quality and properties of GaAs. The epitaxial growth exhibited good uniformity, as evidenced by the uniformity of the cell performance across the wafer, from the center to the edge. The result indicated the potential of high-throughput MOVPE for low-cost production, not only for PV devices but also for other semiconductor applications.

Effects of reduced rates of two insecticides on enzyme activity and mortality of an aphid and its lacewing predator.

PubMed

Booth, L H; Wratten, S D; Kehrli, P

2007-02-01

By applying insecticides at lower rates of active ingredients per unit area, survival rates of the pests' natural enemies can be enhanced, whereas pest mortality can remain high. The effects of reduced application rates of the insecticides lambda-cyhalothrin and dimethoate on the mortality of bird cherry-oat aphid, Rhopalosiphon padi (L.), and lacewing Micromus tasmaniae Walker were determined in the laboratory and field. Cholinesterase (ChE) and glutathione S-transferase (GST) activities in survivors provided a measure of sublethal effects and general fitness. In the laboratory, lacewings were less sensitive than aphids to both insecticides, and dimethoate was more toxic than lambda-cyhalothrin. However, these results could not be recreated in the field, in part due to very low recapture rates. In summary, lambda-cyhalothrin seemed to have no effect on aphids, but it was toxic to lacewings. Dimethoate was far less toxic in the field, but aphids were still more sensitive than were lacewings. Cholinesterase activity was reduced by dimethoate exposure in the laboratory in both species, but there were species-specific differences. Dimethoate and lambda-cyhalothrin had no effects on GST activity in either species. The high mortality rate for lacewings and aphids exposed to dimethoate in the field suggests that the application rate could be reduced to as low as 10% of that recommended by manufacturers, and this should still be highly efficacious against aphids, while protecting the predatory lacewing. Measurement of enzyme activity could provide a useful indicator of "fitness" of survivors.

Dosimetric evaluation of a novel high dose rate (HDR) intraluminal / interstitial brachytherapy applicator for gastrointestinal and bladder cancers

PubMed Central

Aghamiri, Seyyed Mahmoud Reza; Najarian, Siamak; Jaberi, Ramin

2010-01-01

High dose rate (HDR) brachytherapy is one of the accepted treatment modalities in gastro‐intestinal tract and bladder carcinomas. Considering the shortcoming of contact brachytherapy routinely used in gastrointestinal tract in treatment of big tumors or invasive method of bladder treatment, an intraluminal applicator with the capability of insertion into the tumor depth seems to be useful. This study presents some dosimetric evaluations to introduce this applicator to the clinical use. The radiation attenuation characteristics of the applicator were evaluated by means of two dosimetric methods including well‐type chamber and radiochromic film. The proposed 110 cm long applicator has a flexible structure made of stainless steel for easy passage through lumens and a needle tip to drill into big tumors. The 2 mm diameter of the applicator is thick enough for source transition, while easy passage through any narrow lumen such as endoscope or cystoscope working channel is ensured. Well‐chamber results showed an acceptably low attenuation of this steel springy applicator. Performing absolute dosimetry resulted in a correlation coefficient of R=0.9916(p‐value≈10−7) between standard interstitial applicator and the one proposed in this article. This study not only introduces a novel applicator with acceptable attenuation but also proves the response independency of the GAFCHROMIC EBT films to energy. By applying the dose response of the applicator in the treatment planning software, it can be used as a new intraluminal / interstitial applicator. PACS number: 87.53.Bn, 87.53.Jw, 29.40.Cs

Super high-rate fabrication of high-purity carbon nanotube aerogels from floating catalyst method for oil spill cleaning

NASA Astrophysics Data System (ADS)

Khoshnevis, Hamed; Mint, Sandar Myo; Yedinak, Emily; Tran, Thang Q.; Zadhoush, Ali; Youssefi, Mostafa; Pasquali, Matteo; Duong, Hai M.

2018-02-01

In this study, we apply an advanced floating catalyst method to fabricate carbon nanotube (CNT) aerogels at super high deposition rate for oil spill cleaning. The aerogels consist of 3D porous network of stacking double-walled CNT bundles with low catalyst impurity (9%) and high thermal stability (650 °C). With high porosity, surface areas, and water contact angles, the CNT aerogels exhibit a high oil adsorption of up to 107 g/g and good reusability of up to four adsorption-burning cycles. This work suggests that the lightweight, porous, and super hydrophobic CNT aerogels can be promising sorbent materials for environmental applications.

Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

NASA Astrophysics Data System (ADS)

Palmer, Antony L.; Lee, Chris; Ratcliffe, Ailsa J.; Bradley, David; Nisbet, Andrew

2013-10-01

A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit.

Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy.

PubMed

Palmer, Antony L; Lee, Chris; Ratcliffe, Ailsa J; Bradley, David; Nisbet, Andrew

2013-10-07

A novel phantom is presented for 'full system' dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit.

The Influence of Sexual Orientation on the Perceived Fit of Male Applicants for Both Male- and Female-Typed Jobs.

PubMed

Clarke, Heather M; Arnold, Kara A

2018-01-01

Research demonstrates the bias faced by individuals engaged in occupations that are perceived as inconsistent with their gender. The lack of fit model and role congruity theory explain how gender stereotypes give rise to the perception that an individual lacks the attributes necessary to be successful in a gender-incongruent job. Men employed in jobs traditionally held by women are perceived as wimpy and undeserving of respect. The majority of studies in this area have, however, failed to account for the sexual orientation of the individual being rated. Therefore, we carried out an experiment where 128 adults with experience in recruitment and selection, recruited through Qualtrics, rated heterosexual and gay male applicants applying for a gender-typed job. The heterosexual male was rated less effectual, less respect-worthy, and less hirable in the female-typed job condition than in the male-typed job condition. The gay male applicant, however, was rated similarly on all criteria across job gender-types, suggesting the gay male applicant was viewed as androgynous rather than high in femininity and low in masculinity as inferred by implicit inversion theory. The implications of these findings are discussed.

The Influence of Sexual Orientation on the Perceived Fit of Male Applicants for Both Male- and Female-Typed Jobs

PubMed Central

Clarke, Heather M.; Arnold, Kara A.

2018-01-01

Research demonstrates the bias faced by individuals engaged in occupations that are perceived as inconsistent with their gender. The lack of fit model and role congruity theory explain how gender stereotypes give rise to the perception that an individual lacks the attributes necessary to be successful in a gender-incongruent job. Men employed in jobs traditionally held by women are perceived as wimpy and undeserving of respect. The majority of studies in this area have, however, failed to account for the sexual orientation of the individual being rated. Therefore, we carried out an experiment where 128 adults with experience in recruitment and selection, recruited through Qualtrics, rated heterosexual and gay male applicants applying for a gender-typed job. The heterosexual male was rated less effectual, less respect-worthy, and less hirable in the female-typed job condition than in the male-typed job condition. The gay male applicant, however, was rated similarly on all criteria across job gender-types, suggesting the gay male applicant was viewed as androgynous rather than high in femininity and low in masculinity as inferred by implicit inversion theory. The implications of these findings are discussed. PMID:29774007

A state observer for using a slow camera as a sensor for fast control applications

NASA Astrophysics Data System (ADS)

Gahleitner, Reinhard; Schagerl, Martin

2013-03-01

This contribution concerns about a problem that often arises in vision based control, when a camera is used as a sensor for fast control applications, or more precisely, when the sample rate of the control loop is higher than the frame rate of the camera. In control applications for mechanical axes, e.g. in robotics or automated production, a camera and some image processing can be used as a sensor to detect positions or angles. The sample time in these applications is typically in the range of a few milliseconds or less and this demands the use of a camera with a high frame rate up to 1000 fps. The presented solution is a special state observer that can work with a slower and therefore cheaper camera to estimate the state variables at the higher sample rate of the control loop. To simplify the image processing for the determination of positions or angles and make it more robust, some LED markers are applied to the plant. Simulation and experimental results show that the concept can be used even if the plant is unstable like the inverted pendulum.

The experimental research on electrodischarge drilling of high aspect ratio holes in Inconel 718

NASA Astrophysics Data System (ADS)

Lipiec, Piotr; Machno, Magdalena; Skoczypiec, Sebastian

2018-05-01

In recent years the drilling operations become important area of electrodischarge machining (EDM) application. This especially concerns drilling of, small (D< 1mm), cylindrical and high-aspect ratio (L/D > 10) holes in difficult-to-cut materials (i.e. nickel or titanium alloys). Drilling of such a holes is significantly beyond mechanical drilling capabilities. Therefore electrodischarge machining is good and cost efficient alternative for such application. EDM gives possibility to drill accurate, burr free and high aspect ratio holes and is applicable to machine wide range of conductive materials, irrespective of their hardness and toughness. However it is worth to underline its main disadvantages such as: significant tool wear, low material removal rate and poor surface integrity. The last one is especially important in reliable applications in aircraft or medical industry.

Establishing a method of short-term rainfall forecasting based on GNSS-derived PWV and its application.

PubMed

Yao, Yibin; Shan, Lulu; Zhao, Qingzhi

2017-09-29

Global Navigation Satellite System (GNSS) can effectively retrieve precipitable water vapor (PWV) with high precision and high-temporal resolution. GNSS-derived PWV can be used to reflect water vapor variation in the process of strong convection weather. By studying the relationship between time-varying PWV and rainfall, it can be found that PWV contents increase sharply before raining. Therefore, a short-term rainfall forecasting method is proposed based on GNSS-derived PWV. Then the method is validated using hourly GNSS-PWV data from Zhejiang Continuously Operating Reference Station (CORS) network of the period 1 September 2014 to 31 August 2015 and its corresponding hourly rainfall information. The results show that the forecasted correct rate can reach about 80%, while the false alarm rate is about 66%. Compared with results of the previous studies, the correct rate is improved by about 7%, and the false alarm rate is comparable. The method is also applied to other three actual rainfall events of different regions, different durations, and different types. The results show that the method has good applicability and high accuracy, which can be used for rainfall forecasting, and in the future study, it can be assimilated with traditional weather forecasting techniques to improve the forecasted accuracy.

Correlating Questionnaire Data with Actual Usage Data in a Mobile Learning Study for High School Mathematics

ERIC Educational Resources Information Center

Kalloo, Vani; Mohan, Permanand

2012-01-01

A mobile learning research project was conducted in Trinidad and Tobago to determine if mobile learning can assist high school students in learning mathematics. Several innovative techniques were used in this research to address the problem of high failure rates of mathematics in high schools in the Caribbean. A mobile learning application was…

Reinstating lead for high-loaded efficient negative electrode for rechargeable sodium-ion battery

NASA Astrophysics Data System (ADS)

Darwiche, Ali; Dugas, Romain; Fraisse, Bernard; Monconduit, Laure

2016-02-01

Due to its weight and toxicity, Pb is usually not considered as possible anode for Li- and Na-ion (NIBs) batteries. Nevertheless the toxicity is related to specific applications and its recycling is more than 99% which is one of the highest recycling rates on the planet where no other power source is utilized in more applications with such sustainability. For this reason, we have investigated micrometric lead particles as electrode for NIBs in an ether-based electrolyte (1 M NaPF6 in diglyme). The cyclability, coulombic efficiency and rate capability of lead were unexpected. A high loaded lead electrode with 98%wt of Pb and only 1% of carbon additive showed i) a capacity retention of 464 mA h/g after 50 cycles with only 1.5% of capacity loss, which represents a high volumetric capacity of 5289 mA h/cm3 due to the high density of Pb and ii) a very interesting capacity retention even at high current rate (1950 mA/g). In situ XRD study confirmed a sodiation-desodiation process in four steps. Preliminary tests in Pb//Na3V2(PO4)2F3 full cells showed promising results demonstrating that Pb could be a practical candidate for future high energy density Na-ion batteries with an efficient sodiated or non sodiated positive electrode.

Design, fabrication, and evaluation of on-chip micro-supercapacitors

NASA Astrophysics Data System (ADS)

Beidaghi, Majid

Due to the increasing demand for high power and reliable miniaturized energy storage devices, the development of micro-supercapacitors or electrochemical micro-capacitors have attracted much attention in recent years. This dissertation investigates several strategies to develop on-chip micro-supercapacitors with high power and energy density. Micro-supercapacitors based on interdigitated carbon micro-electrode arrays are fabricated through carbon microelectromechanical systems (C-MEMS) technique which is based on carbonization of patterned photoresist. To improve the capacitive behavior, electrochemical activation is performed on carbon micro-electrode arrays. The developed micro-supercapacitors show specific capacitances as high as 75 mFcm-2 at a scan rate of 5 mVs -1 after electrochemical activation for 30 minutes. The capacitance loss is less than 13% after 1000 cyclic voltammetry (CV) cycles. These results indicate that electrochemically activated C-MEMS micro-electrode arrays are promising candidates for on-chip electrochemical micro-capacitor applications. The energy density of micro-supercapacitors was further improved by conformal coating of polypyrrole (PPy) on C-MEMS structures. In these types of micro-devices the three dimensional (3D) carbon microstructures serve as current collectors for high energy density PPy electrodes. The electrochemical characterizations of these micro-supercapacitors show that they can deliver a specific capacitance of about 162.07 mFcm-2 and a specific power of 1.62mWcm -2 at a 20 mVs-1 scan rate. Addressing the need for high power micro-supercapacitors, the application of graphene as electrode materials for micro-supercapacitor was also investigated. The present study suggests a novel method to fabricate graphene-based micro-supercapacitors with thin film or in-plane interdigital electrodes. The fabricated micro-supercapacitors show exceptional frequency response and power handling performance and could effectively charge and discharge at rates as high as 50 Vs-1. CV measurements show that the specific capacitance of the micro-supercapacitor based on reduced graphene oxide and carbon nanotube composites is 6.1 mFcm -2 at scan rate of 0.01Vs-1. At a very high scan rate of 50 Vs-1, a specific capacitance of 2.8 mFcm-2 (stack capacitance of 3.1 Fcm-3) is recorded. This unprecedented performance can potentially broaden the future applications of micro-supercapacitors.

Suitability of point kernel dose calculation techniques in brachytherapy treatment planning

PubMed Central

Lakshminarayanan, Thilagam; Subbaiah, K. V.; Thayalan, K.; Kannan, S. E.

2010-01-01

Brachytherapy treatment planning system (TPS) is necessary to estimate the dose to target volume and organ at risk (OAR). TPS is always recommended to account for the effect of tissue, applicator and shielding material heterogeneities exist in applicators. However, most brachytherapy TPS software packages estimate the absorbed dose at a point, taking care of only the contributions of individual sources and the source distribution, neglecting the dose perturbations arising from the applicator design and construction. There are some degrees of uncertainties in dose rate estimations under realistic clinical conditions. In this regard, an attempt is made to explore the suitability of point kernels for brachytherapy dose rate calculations and develop new interactive brachytherapy package, named as BrachyTPS, to suit the clinical conditions. BrachyTPS is an interactive point kernel code package developed to perform independent dose rate calculations by taking into account the effect of these heterogeneities, using two regions build up factors, proposed by Kalos. The primary aim of this study is to validate the developed point kernel code package integrated with treatment planning computational systems against the Monte Carlo (MC) results. In the present work, three brachytherapy applicators commonly used in the treatment of uterine cervical carcinoma, namely (i) Board of Radiation Isotope and Technology (BRIT) low dose rate (LDR) applicator and (ii) Fletcher Green type LDR applicator (iii) Fletcher Williamson high dose rate (HDR) applicator, are studied to test the accuracy of the software. Dose rates computed using the developed code are compared with the relevant results of the MC simulations. Further, attempts are also made to study the dose rate distribution around the commercially available shielded vaginal applicator set (Nucletron). The percentage deviations of BrachyTPS computed dose rate values from the MC results are observed to be within plus/minus 5.5% for BRIT LDR applicator, found to vary from 2.6 to 5.1% for Fletcher green type LDR applicator and are up to −4.7% for Fletcher-Williamson HDR applicator. The isodose distribution plots also show good agreements with the results of previous literatures. The isodose distributions around the shielded vaginal cylinder computed using BrachyTPS code show better agreement (less than two per cent deviation) with MC results in the unshielded region compared to shielded region, where the deviations are observed up to five per cent. The present study implies that the accurate and fast validation of complicated treatment planning calculations is possible with the point kernel code package. PMID:20589118

CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma: specific technical aspects and clinical results.

PubMed

Sommer, C M; Lemm, G; Hohenstein, E; Bellemann, N; Stampfl, U; Goezen, A S; Rassweiler, J; Kauczor, H U; Radeleff, B A; Pereira, P L

2013-06-01

This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. We included 22 consecutive patients (3 women; age 74.2 ± 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 ± 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 ± 13.6 min and 43.7 ± 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 ± 8.8 months, local recurrence-free survival was 14.4 ± 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 ± 16.6 ml/min/1.73 m(2) before RF ablation vs. 47.2 ± 11.9 ml/min/1.73 m(2) after RF ablation; not significant). CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

Computational Flow Analysis of Ultra High Pressure Firefighting Technology with Application to Long Range Nozzle Design

DTIC Science & Technology

2010-03-01

release; distribution unlimited. Ref AFRL/RXQ Public Affairs Case # 10-100. Document contains color images . Although aqueous fire fighting agent...in conjunction with the standard Eulerian multiphase flow model. The two- equation k- model was selected due to its wide industrial application in...energy (k) and its dissipation rate (). Because of their heuristic development, RANS models have applicable limitations and in general must be

Viterbi equalization for long-distance, high-speed underwater laser communication

NASA Astrophysics Data System (ADS)

Hu, Siqi; Mi, Le; Zhou, Tianhua; Chen, Weibiao

2017-07-01

In long-distance, high-speed underwater laser communication, because of the strong absorption and scattering processes, the laser pulse is stretched with the increase in communication distance and the decrease in water clarity. The maximum communication bandwidth is limited by laser-pulse stretching. Improving the communication rate increases the intersymbol interference (ISI). To reduce the effect of ISI, the Viterbi equalization (VE) algorithm is used to estimate the maximum-likelihood receiving sequence. The Monte Carlo method is used to simulate the stretching of the received laser pulse and the maximum communication rate at a wavelength of 532 nm in Jerlov IB and Jerlov II water channels with communication distances of 80, 100, and 130 m, respectively. The high-data rate communication performance for the VE and hard-decision algorithms is compared. The simulation results show that the VE algorithm can be used to reduce the ISI by selecting the minimum error path. The trade-off between the high-data rate communication performance and minor bit-error rate performance loss makes VE a promising option for applications in long-distance, high-speed underwater laser communication systems.

Academic Characteristics of Orthopaedic Surgery Residency Applicants from 2007 to 2014.

PubMed

DePasse, J Mason; Palumbo, Mark A; Eberson, Craig P; Daniels, Alan H

2016-05-04

Based on a relatively stable match rate, several authors have concluded that the competition for orthopaedic residency positions has not changed over the past 3 decades. However, the objective measures of applicant competitiveness have not been quantified in detail. National Resident Matching Program (NRMP) data from 2007 to 2014 for U.S. orthopaedic surgery applicants were compared with data for applicants to all specialties. Trends in the United Stated Medical Licensing Examination (USMLE) Step-1 and Step-2 scores, publications and research experiences, Alpha Omega Alpha (AOA) status, and the presence of an advanced degree are reported. From 2007 to 2014, the match rate for orthopaedic surgery applicants remained stable near 80% (p = 0.14). For orthopaedic applicants who matched, the mean USMLE Step-1 scores increased from 234 points in 2007 to 245 points in 2014 (p = 0.005), and the mean scores increased from 220 points in 2007 to 229 points in 2014 for all applicants (p = 0.019). The mean USMLE Step-2 scores of orthopaedic applicants who matched increased from 235 points in 2007 to 251 points in 2014 (p = 0.005), and the mean scores of all applicants increased from 225 points in 2007 to 242 points in 2014 (p = 0.002). The mean number of research publications, presentations, and abstracts reported by orthopaedic applicants who matched more than doubled from 3.0 in 2007 to 6.7 in 2014 (p = 0.02) and increased less dramatically for all applicants from 2.2 in 2007 to 4.2 in 2014 (p = 0.004). The percentage of orthopaedic applicants elected to AOA or with advanced degrees did not significantly change (p > 0.2). Although orthopaedic applicants with AOA status experienced a very high match rate (97.1% in 2014), those with advanced degrees experienced match rates similar to or slightly lower than the applicant pool (73.7% in 2014). The USMLE Step-1 and 2 scores of U.S. orthopaedic surgery residency applicants have increased significantly from 2007 to 2014. Additionally, the number of publications and presentations reported by orthopaedic applicants has more than doubled. These factors signal an increasing level of academic accomplishment in orthopaedic surgery applicants despite a consistent match rate. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

US Army Research Laboratory Materials Center of Excellence. Dynamic Behavior of Noncrystalline and Nanocrystalline Metallic Systems: July 2011-June 2012 Annual Report

DTIC Science & Technology

2015-03-01

Presentations 18 6. High-Rate Loading of Piezoelectric Ceramics 19 6.1 Objective 19 6.2 Quarterly Deliverables 19 6.3 Research Summary 19 6.4...the mechanical properties and to control the failure, with the emphasis on those properties and processes that are unique to BCC materials . The...application to molybdenum. 19 6. High-Rate Loading of Piezoelectric Ceramics Core Faculty: KT Ramesh ARL Collaborators: George Gazonas, Jim McCauley

High-rate Li-MnO2 cells for aerospace use

NASA Technical Reports Server (NTRS)

Becker-Kaiser, R.; Ruch, J.; Harms, H.-J.; Schmoede, P.; Welsh, J. R.; Vollmers, M.-J.; Pack, H.

1992-01-01

A series of comparative studies were undertaken on representative cells as objectively as possible in order to appreciate the respective advantages of the different systems. After reviewing the first test results our attention was soon focussed on the following four lithium systems: (1) Li-SOCl2; (2) Li-SO2; (3) Li-(CF(sub x))(sub n); and (4) Li-MnO2. This resulted in the decision in 1982 to adopt the Li-MnO2 system for high-rate applications.

Will algorithms modified with soil and weather information improve in-field reflectance-sensing corn nitrogen applications?

USDA-ARS?s Scientific Manuscript database

Nitrogen (N) needs to support corn (Zea mays L.) production can be highly variable within fields. Canopy reflectance sensing for assessing crop N health has been implemented on many farmers’ fields to side-dress or top-dress variable-rate N application, but at times farmers report the performance of...

1.55 µm InAs/GaAs Quantum Dots and High Repetition Rate Quantum Dot SESAM Mode-locked Laser

NASA Astrophysics Data System (ADS)

Zhang, Z. Y.; Oehler, A. E. H.; Resan, B.; Kurmulis, S.; Zhou, K. J.; Wang, Q.; Mangold, M.; Süedmeyer, T.; Keller, U.; Weingarten, K. J.; Hogg, R. A.

2012-06-01

High pulse repetition rate (>=10 GHz) diode-pumped solid-state lasers, modelocked using semiconductor saturable absorber mirrors (SESAMs) are emerging as an enabling technology for high data rate coherent communication systems owing to their low noise and pulse-to-pulse optical phase-coherence. Quantum dot (QD) based SESAMs offer potential advantages to such laser systems in terms of reduced saturation fluence, broader bandwidth, and wavelength flexibility. Here, we describe the development of an epitaxial process for the realization of high optical quality 1.55 µm In(Ga)As QDs on GaAs substrates, their incorporation into a SESAM, and the realization of the first 10 GHz repetition rate QD-SESAM modelocked laser at 1.55 µm, exhibiting ~2 ps pulse width from an Er-doped glass oscillator (ERGO). With a high areal dot density and strong light emission, this QD structure is a very promising candidate for many other applications, such as laser diodes, optical amplifiers, non-linear and photonic crystal based devices.

NASA Astrophysics Data System (ADS)

Scapin, M.; Peroni, L.; Fichera, C.; Cambriani, A.

2014-08-01

High chromium ferritic/martensitic steel T91 (9% Cr, 1% Mo), on account of its radiation resistance, is a candidate material for nuclear reactor applications. Its joining by an impact method to create a cold joint is tested in the realm of scoping tests toward the safe operation of nuclear fuels, encapsulated in representative T91 materials. Hitherto, T91 mechanical characterization at high strain rates is relatively unknown, particularly, in relation to impact joining and also to nuclear accidents. In this study, the mechanical characterization of T91 steel was performed in tension by varying the strain-rate (10-3 up to 104 s-1) and temperature (20-800°C) on dog-bone specimens, using standard testing machines or Hopkinson Bar apparati. As expected, the material is both temperature and strain-rate sensitive and different sets of parameters for the Johnson-Cook strength model were extracted via a numerical inverse procedure, in order to obtain the most suitable set to be used in this field of applications.

Electromagnetically-Actuated Reciprocating Pump for High-Flow-Rate Microfluidic Applications

PubMed Central

Ke, Ming-Tsun; Zhong, Jian-Hao; Lee, Chia-Yen

2012-01-01

This study presents an electromagnetically-actuated reciprocating pump for high-flow-rate microfluidic applications. The pump comprises four major components, namely a lower glass plate containing a copper microcoil, a middle PMMA plate incorporating a PDMS diaphragm with a surface-mounted magnet, upper PMMA channel plates, and a ball-type check valve located at the channel inlet. When an AC current is passed through the microcoil, an alternating electromagnetic force is established between the coil and the magnet. The resulting bi-directional deflection of the PDMS diaphragm causes the check-valve to open and close; thereby creating a pumping effect. The experimental results show that a coil input current of 0.4 A generates an electromagnetic force of 47 mN and a diaphragm deflection of 108 μm. Given an actuating voltage of 3 V and a driving frequency of 15 Hz, the flow rate is found to be 13.2 mL/min under zero head pressure conditions. PMID:23201986

Multiport backside-illuminated CCD imagers for high-frame-rate camera applications

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Sauer, Donald J.; Hseuh, Fu-Lung; Shallcross, Frank V.; Taylor, Gordon C.; Meray, Grazyna M.; Tower, John R.; Harrison, Lorna J.; Lawler, William B.

1994-05-01

Two multiport, second-generation CCD imager designs have been fabricated and successfully tested. They are a 16-port 512 X 512 array and a 32-port 1024 X 1024 array. Both designs are back illuminated, have on-chip CDS, lateral blooming control, and use a split vertical frame transfer architecture with full frame storage. The 512 X 512 device has been operated at rates over 800 frames per second. The 1024 X 1024 device has been operated at rates over 300 frames per second. The major changes incorporated in the second-generation design are, reduction in gate length in the output area to give improved high-clock-rate performance, modified on-chip CDS circuitry for reduced noise, and optimized implants to improve performance of blooming control at lower clock amplitude. This paper discusses the imager design improvements and presents measured performance results at high and moderate frame rates. The design and performance of three moderate frame rate cameras are discussed.

Ultra-high resolution coded wavefront sensor.

PubMed

Wang, Congli; Dun, Xiong; Fu, Qiang; Heidrich, Wolfgang

2017-06-12

Wavefront sensors and more general phase retrieval methods have recently attracted a lot of attention in a host of application domains, ranging from astronomy to scientific imaging and microscopy. In this paper, we introduce a new class of sensor, the Coded Wavefront Sensor, which provides high spatio-temporal resolution using a simple masked sensor under white light illumination. Specifically, we demonstrate megapixel spatial resolution and phase accuracy better than 0.1 wavelengths at reconstruction rates of 50 Hz or more, thus opening up many new applications from high-resolution adaptive optics to real-time phase retrieval in microscopy.

Miniaturized Stretchable and High-Rate Linear Supercapacitors

NASA Astrophysics Data System (ADS)

Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

2017-07-01

Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g-1 at the discharge current of 1 A g-1.

Miniaturized Stretchable and High-Rate Linear Supercapacitors.

PubMed

Zhu, Wenjun; Zhang, Yang; Zhou, Xiaoshuang; Xu, Jiang; Liu, Zunfeng; Yuan, Ningyi; Ding, Jianning

2017-12-01

Linear stretchable supercapacitors have attracted much attention because they are well suited to applications in the rapidly expanding field of wearable electronics. However, poor conductivity of the electrode material, which limits the transfer of electrons in the axial direction of the linear supercapacitors, leads to a serious loss of capacity at high rates. To solve this problem, we use gold nanoparticles to decorate aligned multiwall carbon nanotube to fabricate stretchable linear electrodes. Furthermore, we have developed fine stretchable linear supercapacitors, which exhibited an extremely high elasticity up to 400% strain with a high capacitance of about 8.7 F g -1 at the discharge current of 1 A g -1 .

Dosimetric impact of applicator displacement during high dose rate (HDR) Cobalt-60 brachytherapy for cervical cancer: A planning study

NASA Astrophysics Data System (ADS)

Yong, J. S.; Ung, N. M.; Jamalludin, Z.; Malik, R. A.; Wong, J. H. D.; Liew, Y. M.; Ng, K. H.

2016-02-01

We investigated the dosimetric impact of applicator displacement on dose specification during high dose rate (HDR) Cobalt-60 (Co-60) brachytherapy for cervical cancer through a planning study. Eighteen randomly selected HDR full insertion plans were restrospectively studied. The tandem and ovoids were virtually shifted translationally and rotationally in the x-, y- and z-axis directions on the treatment planning system. Doses to reference points and volumes of interest in the plans with shifted applicators were compared with the original plans. The impact of dose displacement on 2D (point-based) and 3D (volume-based) treatment planning techniques was also assessed. A ±2 mm translational y-axis applicator shift and ±4° rotational x-axis applicator shift resulted in dosimetric changes of more than 5% to organs at risk (OAR) reference points. Changes to the maximum doses to 2 cc of the organ (D2cc) in 3D planning were statistically significant and higher than the reference points in 2D planning for both the rectum and bladder (p<0.05). Rectal D2cc was observed to be the most sensitive to applicator displacement among all dose metrics. Applicator displacement that is greater than ±2 mm translational y-axis and ±4° rotational x-axis resulted in significant dose changes to the OAR. Thus, steps must be taken to minimize the possibility of applicator displacement during brachytherapy.

Predictions and Experimental Microstructural Characterization of High Strain Rate Failure Modes in Layered Aluminum Composites

NASA Astrophysics Data System (ADS)

Khanikar, Prasenjit

Different aluminum alloys can be combined, as composites, for tailored dynamic applications. Most investigations pertaining to metallic alloy layered composites, however, have been based on quasi-static approaches. The dynamic failure of layered metallic composites, therefore, needs to be characterized in terms of strength, toughness, and fracture response. A dislocation-density based crystalline plasticity formulation, finite-element techniques, rational crystallographic orientation relations and a new fracture methodology were used to predict the failure modes associated with the high strain rate behavior of aluminum layered composites. Two alloy layers, a high strength alloy, aluminum 2195, and an aluminum alloy 2139, with high toughness, were modeled with representative microstructures that included precipitates, dispersed particles, and different grain boundary (GB) distributions. The new fracture methodology, based on an overlap method and phantom nodes, is used with a fracture criteria specialized for fracture on different cleavage planes. One of the objectives of this investigation, therefore, was to determine the optimal arrangements of the 2139 and 2195 aluminum alloys for a metallic layered composite that would combine strength, toughness and fracture resistance for high strain-rate applications. Different layer arrangements were investigated for high strain-rate applications, and the optimal arrangement was with the high toughness 2139 layer on the bottom, which provided extensive shear strain localization, and the high strength 2195 layer on the top for high strength resistance. The layer thickness of the bottom high toughness layer also affected the bending behavior of the roll-boned interface and the potential delamination of the layers. Shear strain localization, dynamic cracking and delamination were the mutually competing failure mechanisms for the layered metallic composite, and control of these failure modes can be optimized for high strain-rate applications. The second major objective of this investigation was the use of recently developed dynamic fracture formulations to model and analyze the crack nucleation and propagation of aluminum layered composites subjected to high strain rate loading conditions and how microstructural effects, such as precipitates, dispersed particles, and GB orientations affect failure evolution. This dynamic fracture approach is used to investigate crack nucleation and crack growth as a function of the different microstructural characteristics of each alloy in layered composites with and without pre-existing cracks. The zigzag nature of the crack paths were mainly due to the microstructural features, such as precipitates and dispersed particles distributions and orientations ahead of the crack front, and it underscored the capabilities of the fracture methodology. The evolution of dislocation density and the formation of localized shear slip contributed to the blunting of the propagating crack. Extensive geometrical and thermal softening due to the localized plastic slip also affected crack path orientations and directions. These softening mechanisms resulted in the switching of cleavage planes, which affected crack path orientations. Interface delamination can also have an important role in the failure and toughening of the layered composites. Different scenarios of delamination were investigated, such as planar crack growth and crack penetration into the layers. The presence of brittle surface oxide platelets in the interface region also significantly influenced the interface delamination process. Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) characterization provided further physical insights and validation of the predictive capabilities. The inherent microstructural features of each alloy play a significant role in the dynamic fracture, shear strain localization, and interface delamination of the layered metallic composite. These microstructural features, such as precipitates, dispersed particles, and GB orientations and distributions can be optimized for desired behavior of metallic composites.

Utilizing Positive Behavior Supports in High School Settings to Improve School Completion Rates for Students with High Incidence Conditions

ERIC Educational Resources Information Center

Bohanon, Hank; Flannery, K. Brigid; Malloy, JoAnne; Fenning, Pamela

2009-01-01

The integration of primary, secondary, and tertiary interventions through positive behavior supports (PBS) can provide benefit for students, staff, and families (Bohanon et al., 2006; Turnbull et al., 2002). However, there is limited application of PBS to high schools settings (Sugai, Flannery, & Bohanon, 2004). However, preliminary data is…

Parents' "Hard" Knowledge of Admission Criteria and Acceptance in Philadelphia's High School Choice Process

ERIC Educational Resources Information Center

Haxton, Clarisse L.; Neild, Ruth Curran

2012-01-01

We examine parents' knowledge of discrete, verifiable facts--what we call "hard knowledge"--in a high school application process. Using parent survey data (n = 658) from the School District of Philadelphia, this study examines whether parents knew the admission criteria and acceptance rate at the high school they most wanted their child…

CALCINATION AND SINTERING MODELS FOR APPLICATION TO HIGH-TEMPERATURE, SHORT-TIME SULFATION OF CALCIUM-BASED SORBENTS

EPA Science Inventory

To simulate the staged availability of transient high surface area CaO observed in high-temperature flow-reactor data, the rate of calcination of CaCO3 or Ca(OH)2 is described by an empirical modification of the shrinking-core model. The physical model depicts particle decomposi...

Copper link evaluations/solutions for fiber channel, SSA, SONET, ATM, and other services through 4 Gb/sec: basic information, test results, and evaluation

NASA Astrophysics Data System (ADS)

Leib, Michael J.

1995-10-01

Technitrol, the original designer of MIL-STD-1553 transformers, the original military 1Mb/s LAN, has advanced the state of the art one further notch, introducing a series of transceivers that allow high speed (through 1 Gb/s) data transmission over copper wire instead of fiber optic cable. One such device can be employed to implement the Fiber Channel Interface as defined by hte X3T11 ANSI Fibre Channel Committee using either mini coax, Type 1 shielded twisted pair, twinax or video cable. The technology now exists to upgrade data transmission rates on current physical media to speeds formerly only available with fiber optic cabling. Copper transceiver technology provides a cost effective alternative for dealing with demanding high speed applications such as high speed serial data transfer, high speed disk and tape storage transfer, imaging telemetry, radar, and other avionics applications. Eye diagrams will be presented to show that excellent data transmission at rates of 1 gigabit/sec with low jitter is capable over mini coax at distances to approximately 50 meters, shielded twisted pair and twinax cable to distances of 105 meters, and video cable to distances of 175 meters. Distances are further at lower data rates. As a member of the X3T11 ANSI Fiber Channel Committee, Technitrol has developed a Physical Media (copper wire) Dependant (PMD) transceiver not only compliant with the Fibre Channel Specifications but exceeding the specifications by a factor greater than four. Conceivably, this opens high speed interconnections for today's high data rate requirements to copper cabling systems. Fibre Optic problems need not be dealt with to obtain data transfers for high speed information transfers.

Laser driven nuclear science and applications: The need of high efficiency, high power and high repetition rate Laser beams

NASA Astrophysics Data System (ADS)

Gales, S.

2015-10-01

Extreme Light Infrastructure (ELI) is a pan European research initiative selected on the European Strategy Forum on Research Infrastructures Roadmap that aims to close the gap between the existing laboratory-based laser driven research and international facility-grade research centre. The ELI-NP facility, one of the three ELI pillars under construction, placed in Romania and to be operational in 2018, has as core elements a couple of new generation 10 PW laser systems and a narrow bandwidth Compton backscattering gamma source with photon energies up to 19 MeV. ELI-NP will address nuclear photonics, nuclear astrophysics and quantum electrodynamics involving extreme photon fields. Prospective applications of high power laser in nuclear astrophysics, accelerator physics, in particular towards future Accelerator Driven System, as well as in nuclear photonics, for detection and characterization of nuclear material, and for nuclear medicine, will be discussed. Key issues in these research areas will be at reach with significant increase of the repetition rates and of the efficiency at the plug of the high power laser systems as proposed by the ICAN collaboration.

Mechanical characterization of alloys in extreme conditions of high strain rates and high temperature

NASA Astrophysics Data System (ADS)

Cadoni, Ezio

2018-03-01

The aim of this paper is the description of the mechanical characterization of alloys under extreme conditions of temperature and loading. In fact, in the frame of the Cost Action CA15102 “Solutions for Critical Raw Materials Under Extreme Conditions (CRM-EXTREME)” this aspect is crucial and many industrial applications have to consider the dynamic response of materials. Indeed, for a reduction and substitution of CRMs in alloys is necessary to design the materials and understand if the new materials behave better or if the substitution or reduction badly affect their performance. For this reason, a deep knowledge of the mechanical behaviour at high strain-rates of considered materials is required. In general, machinery manufacturing industry or transport industry as well as energy industry have important dynamic phenomena that are simultaneously affected by extended strain, high strain-rate, damage and pressure, as well as conspicuous temperature gradients. The experimental results in extreme conditions of high strain rate and high temperature of an austenitic stainless steel as well as a high-chromium tempered martensitic reduced activation steel Eurofer97 are presented.

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

Song, Bo; Nelson, Kevin; Jin, Helena

Iridium alloys have been utilized as structural materials for certain high-temperature applications, due to their superior strength and ductility at elevated temperatures. The mechanical properties, including failure response at high strain rates and elevated temperatures of the iridium alloys need to be characterized to better understand high-speed impacts at elevated temperatures. A DOP-26 iridium alloy has been dynamically characterized in compression at elevated temperatures with high-temperature Kolsky compression bar techniques. However, the dynamic high-temperature compression tests were not able to provide sufficient dynamic high-temperature failure information of the iridium alloy. In this study, we modified current room-temperature Kolsky tension barmore » techniques for obtaining dynamic tensile stress-strain curves of the DOP-26 iridium alloy at two different strain rates (~1000 and ~3000 s-1) and temperatures (~750°C and ~1030°C). The effects of strain rate and temperature on the tensile stress-strain response of the iridium alloy were determined. The DOP-26 iridium alloy exhibited high ductility in stress-strain response that strongly depended on both strain rate and temperature.« less

Highly efficient, versatile, self-Q-switched, high-repetition-rate microchip laser generating Ince-Gaussian modes for optical trapping

NASA Astrophysics Data System (ADS)

Dong, Jun; He, Yu; Zhou, Xiao; Bai, Shengchuang

2016-03-01

Lasers operating in the Ince-Gaussian (IG) mode have potential applications for optical manipulation of microparticles and formation of optical vortices, as well as for optical trapping and optical tweezers. Versatile, self-Q-switched, high-peak-power, high-repetition-rate Cr, Nd:YAG microchip lasers operating in the IG mode are implemented under tilted, tightly focused laser-diode pumping. An average output power of over 2 W is obtained at an absorbed pump power of 6.4 W. The highest optical-to-optical efficiency of 33.2% is achieved at an absorbed pump power of 3.9 W. Laser pulses with a pulse energy of 7.5 μJ, pulse width of 3.5 ns and peak power of over 2 kW are obtained. A repetition rate up to 335 kHz is reached at an absorbed pump power of 5.8 W. Highly efficient, versatile, IG-mode lasers with a high repetition rate and a high peak power ensure a better flexibility in particle manipulation and optical trapping.

Highly efficient, versatile, self-Q-switched, high-repetition-rate microchip laser generating Ince–Gaussian modes for optical trapping

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

Jun Dong; Yu He; Xiao Zhou

2016-03-31

Lasers operating in the Ince-Gaussian (IG) mode have potential applications for optical manipulation of microparticles and formation of optical vortices, as well as for optical trapping and optical tweezers. Versatile, self-Q-switched, high-peak-power, high-repetition-rate Cr, Nd:YAG microchip lasers operating in the IG mode are implemented under tilted, tightly focused laser-diode pumping. An average output power of over 2 W is obtained at an absorbed pump power of 6.4 W. The highest optical-to-optical efficiency of 33.2% is achieved at an absorbed pump power of 3.9 W. Laser pulses with a pulse energy of 7.5 μJ, pulse width of 3.5 ns and peakmore » power of over 2 kW are obtained. A repetition rate up to 335 kHz is reached at an absorbed pump power of 5.8 W. Highly efficient, versatile, IG-mode lasers with a high repetition rate and a high peak power ensure a better flexibility in particle manipulation and optical trapping. (control of laser radiation parameters)« less

Imputing data that are missing at high rates using a boosting algorithm

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

Cauthen, Katherine Regina; Lambert, Gregory; Ray, Jaideep

Traditional multiple imputation approaches may perform poorly for datasets with high rates of missingness unless many m imputations are used. This paper implements an alternative machine learning-based approach to imputing data that are missing at high rates. Here, we use boosting to create a strong learner from a weak learner fitted to a dataset missing many observations. This approach may be applied to a variety of types of learners (models). The approach is demonstrated by application to a spatiotemporal dataset for predicting dengue outbreaks in India from meteorological covariates. A Bayesian spatiotemporal CAR model is boosted to produce imputations, andmore » the overall RMSE from a k-fold cross-validation is used to assess imputation accuracy.« less

Application of balancing methods in modeling the penicillin fermentation.

PubMed

Heijnen, J J; Roels, J A; Stouthamer, A H

1979-12-01

This paper shows the application of elementary balancing methods in combination with simple kinetic equations in the formulation of an unstructured model for the fed-batch process for the production of penicillin. The rate of substrate uptake is modeled with a Monod-type relationship. The specific penicillin production rate is assumed to be a function of growth rate. Hydrolysis of penicillin to penicilloic acid is assumed to be first order in penicillin. In simulations with the present model it is shown that the model, although assuming a strict relationship between specific growth rate and penicillin productivity, allows for the commonly observed lag phase in the penicillin concentration curve and the apparent separation between growth and production phase (idiophase-trophophase concept). Furthermore it is shown that the feed rate profile during fermentation is of vital importance in the realization of a high production rate throughout the duration of the fermentation. It is emphasized that the method of modeling presented may also prove rewarding for an analysis of fermentation processes other than the penicillin fermentation.

Architecture and applications of a high resolution gated SPAD image sensor

PubMed Central

Burri, Samuel; Maruyama, Yuki; Michalet, Xavier; Regazzoni, Francesco; Bruschini, Claudio; Charbon, Edoardo

2014-01-01

We present the architecture and three applications of the largest resolution image sensor based on single-photon avalanche diodes (SPADs) published to date. The sensor, fabricated in a high-voltage CMOS process, has a resolution of 512 × 128 pixels and a pitch of 24 μm. The fill-factor of 5% can be increased to 30% with the use of microlenses. For precise control of the exposure and for time-resolved imaging, we use fast global gating signals to define exposure windows as small as 4 ns. The uniformity of the gate edges location is ∼140 ps (FWHM) over the whole array, while in-pixel digital counting enables frame rates as high as 156 kfps. Currently, our camera is used as a highly sensitive sensor with high temporal resolution, for applications ranging from fluorescence lifetime measurements to fluorescence correlation spectroscopy and generation of true random numbers. PMID:25090572

High temperature braided rope seals for static sealing applications

NASA Technical Reports Server (NTRS)

Adams, Michael L.; Olsen, Andrew; Darolia, Ram; Steinetz, Bruce M.; Bartolotta, Paul A.

1996-01-01

Achieving efficiency and performance goals of advanced aircraft and industrial systems are leading designers to implement high temperature materials such as ceramics and intermetallics. Generally these advanced materials are applied selectively in the highest temperature sections of the engine system including the combustor and high pressure turbine, amongst others. Thermal strains that result in attaching the low expansion-rate components to high expansion rate superalloy structures can cause significant life reduction in the components. Seals are being designed to both seal and to serve as compliant mounts allowing for relative thermal growths between high temperature but brittle primary structures and the surrounding support structures. Designers require high temperature, low-leakage, compliant seals to mitigate thermal stresses and control parasitic and cooling airflow between structures. NASA is developing high temperature braided rope seals in a variety of configurations to help solve these problems. This paper will describe the types of seals being developed, describe unique test techniques used to assess seal performance, and present leakage flow data under representative pressure, temperature and scrubbing conditions. Feasibility of the braided rope seals for both an industrial tube seal and a turbine vane seal application is also demonstrated.

Impact of Various Parameters on the Performance of Inter-aircraft Optical Wireless Communication Link

NASA Astrophysics Data System (ADS)

Singh, Mehtab

2017-12-01

Optical wireless communication (OWC) systems also known as Free space optics (FSO) are capable of providing high channel bandwidth, high data transmission rates, low power consumption, and high security. OWC links are being considered in different applications such as inter-satellite links, terrestrial links, and inter-aircraft communication links. This paper investigates the impact of different system parameters such as transmission power level, operating wavelength, transmitter pointing error angle, bit transmission rate, atmospheric attenuation, antenna aperture diameter, geometric losses, the responsivity of the photodetector, and link range on the performance of inter-aircraft optical wireless communication link.

The study of high-speed surface dynamics using a pulsed proton beam

NASA Astrophysics Data System (ADS)

Buttler, William T.; Oro, David M.; Preston, Dean; Mikaelian, Karnig O.; Cherne, Frank J.; Hixson, Robert S.; Mariam, Fesseha G.; Morris, Christopher L.; Stone, Joseph B.; Terrones, Guillermo; Tupa, Dale

2012-03-01

We present experimental results supporting physics based ejecta model development, where we assume ejecta form as a special limiting case of a Richtmyer-Meshkov (RM) instability with Atwood number A = -1. We present and use data to test established RM spike and bubble growth rate theory through application of modern laser Doppler velocimetry techniques applied in a novel manner to coincidentally measure bubble and spike velocities from shocked metals. We also explore the link of ejecta formation from a solid material to its plastic flow stress at high-strain rates (107/s) and high strains (700%).

A high repetition deterministic single ion source

NASA Astrophysics Data System (ADS)

Sahin, C.; Geppert, P.; Müllers, A.; Ott, H.

2017-12-01

We report on a deterministic single ion source with high repetition rate and high fidelity. The source employs a magneto-optical trap, where ultracold rubidium atoms are photoionized. The electrons herald the creation of a corresponding ion, whose timing information is used to manipulate its trajectory in flight. We demonstrate an ion rate of up to 4× {10}4 {{{s}}}-1 and achieve a fidelity for single ion operation of 98%. The technique can be used for all atomic species, which can be laser-cooled, and opens up new applications in ion microscopy, ion implantation and surface spectroscopy.

Selective Catalytic Combustion Sensors for Reactive Organic Analysis

NASA Technical Reports Server (NTRS)

Innes, W. B.

1971-01-01

Sensors involving a vanadia-alumina catalyst bed-thermocouple assembly satisfy requirements for simple, reproducible and rapid continuous analysis or reactive organics. Responses generally increase with temperature to 400 C and increase to a maximum with flow rate/catalyst volume. Selectivity decreases with temperature. Response time decreases with flow rate and increases with catalyst volume. At chosen optimum conditions calculated response which is additive and linear agrees better with photochemical reactivity than other methods for various automotive sources, and response to vehicle exhaust is insensitive to flow rate. Application to measurement of total reactive organics in vehicle exhaust as well as for gas chromatography detection illustrate utility. The approach appears generally applicable to high thermal effect reactions involving first order kinetics.

An 802.11 n wireless local area network transmission scheme for wireless telemedicine applications.

PubMed

Lin, C F; Hung, S I; Chiang, I H

2010-10-01

In this paper, an 802.11 n transmission scheme is proposed for wireless telemedicine applications. IEEE 802.11n standards, a power assignment strategy, space-time block coding (STBC), and an object composition Petri net (OCPN) model are adopted. With the proposed wireless system, G.729 audio bit streams, Joint Photographic Experts Group 2000 (JPEG 2000) clinical images, and Moving Picture Experts Group 4 (MPEG-4) video bit streams achieve a transmission bit error rate (BER) of 10-7, 10-4, and 103 simultaneously. The proposed system meets the requirements prescribed for wireless telemedicine applications. An essential feature of this proposed transmission scheme is that clinical information that requires a high quality of service (QoS) is transmitted at a high power transmission rate with significant error protection. For maximizing resource utilization and minimizing the total transmission power, STBC and adaptive modulation techniques are used in the proposed 802.11 n wireless telemedicine system. Further, low power, direct mapping (DM), low-error protection scheme, and high-level modulation are adopted for messages that can tolerate a high BER. With the proposed transmission scheme, the required reliability of communication can be achieved. Our simulation results have shown that the proposed 802.11 n transmission scheme can be used for developing effective wireless telemedicine systems.

High Broadband Spectral Resolving Transition-Edge Sensors for High Count-Rate Astrophysical Applications

NASA Technical Reports Server (NTRS)

Smith, Stephen

2011-01-01

We are developing arrays of transition-edge sensor (TES) X-ray detectors optimized for high count-rate solar astronomy applications where characterizing the high velocity motions of X-ray jets in solar flares is of particular interest. These devices are fabricated on thick Si substrates and consist of 35x35micron^2 TESs with 4.5micron thick, 60micron pitch, electroplated absorbers. We have tested devices fabricated with different geometric stem contact areas with the TES and surrounding substrate area, which allows us to investigate the loss of athermal phonons to the substrate. Results show a correlation between the stem contact area and a non-Gaussian broadening in the spectral line shape consistent with athermal phonon loss. When the contact area is minimized we have obtained remarkable board-band spectral resolving capabilities of 1.3 plus or minus 0.leV at an energy of 1.5 keV, 1.6 plus or minus 0.1 eV at 5.9 keV and 2.0 plus or minus 0.1 eV at 8 keV. This, coupled with a capability of accommodating 100's of counts per second per pixel makes these devices an exciting prospect of future x-ray astronomy applications.

Compact microwave ion source for industrial applications.

PubMed

Cho, Yong-Sub; Kim, Dae-Il; Kim, Han-Sung; Seol, Kyung-Tae; Kwon, Hyeok-Jung; Hong, In-Seok

2012-02-01

A 2.45 GHz microwave ion source for ion implanters has many good properties for industrial application, such as easy maintenance and long lifetime, and it should be compact for budget and space. But, it has a dc current supply for the solenoid and a rf generator for plasma generation. Usually, they are located on high voltage platform because they are electrically connected with beam extraction power supply. Using permanent magnet solenoid and multi-layer dc break, high voltage deck and high voltage isolation transformer can be eliminated, and the dose rate on targets can be controlled by pulse duty control with semiconductor high voltage switch. Because the beam optics does not change, beam transfer components, such as focusing elements and beam shutter, can be eliminated. It has shown the good performances in budget and space for industrial applications of ion beams.

High-Capacity and Long-Cycle Life Aqueous Rechargeable Lithium-Ion Battery with the FePO4 Anode.

PubMed

Wang, Yuesheng; Yang, Shi-Ze; You, Ya; Feng, Zimin; Zhu, Wen; Gariépy, Vincent; Xia, Jiexiang; Commarieu, Basile; Darwiche, Ali; Guerfi, Abdelbast; Zaghib, Karim

2018-02-28

Aqueous lithium-ion batteries are emerging as strong candidates for a great variety of energy storage applications because of their low cost, high-rate capability, and high safety. Exciting progress has been made in the search for anode materials with high capacity, low toxicity, and high conductivity; yet, most of the anode materials, because of their low equilibrium voltages, facilitate hydrogen evolution. Here, we show the application of olivine FePO 4 and amorphous FePO 4 ·2H 2 O as anode materials for aqueous lithium-ion batteries. Their capacities reached 163 and 82 mA h/g at a current rate of 0.2 C, respectively. The full cell with an amorphous FePO 4 ·2H 2 O anode maintained 92% capacity after 500 cycles at a current rate of 0.2 C. The acidic aqueous electrolyte in the full cells prevented cathodic oxygen evolution, while the higher equilibrium voltage of FePO 4 avoided hydrogen evolution as well, making them highly stable. A combination of in situ X-ray diffraction analyses and computational studies revealed that olivine FePO 4 still has the biphase reaction in the aqueous electrolyte and that the intercalation pathways in FePO 4 ·2H 2 O form a 2-D mesh. The low cost, high safety, and outstanding electrochemical performance make the full cells with olivine or amorphous hydrated FePO 4 anodes commercially viable configurations for aqueous lithium-ion batteries.

A long-life, high-rate lithium/sulfur cell: a multifaceted approach to enhancing cell performance.

PubMed

Song, Min-Kyu; Zhang, Yuegang; Cairns, Elton J

2013-01-01

Lithium/sulfur (Li/S) cells are receiving significant attention as an alternative power source for zero-emission vehicles and advanced electronic devices due to the very high theoretical specific capacity (1675 mA·h/g) of the sulfur cathode. However, the poor cycle life and rate capability have remained a grand challenge, preventing the practical application of this attractive technology. Here, we report that a Li/S cell employing a cetyltrimethyl ammonium bromide (CTAB)-modified sulfur-graphene oxide (S-GO) nanocomposite cathode can be discharged at rates as high as 6C (1C = 1.675 A/g of sulfur) and charged at rates as high as 3C while still maintaining high specific capacity (~ 800 mA·h/g of sulfur at 6C), with a long cycle life exceeding 1500 cycles and an extremely low decay rate (0.039% per cycle), perhaps the best performance demonstrated so far for a Li/S cell. The initial estimated cell-level specific energy of our cell was ~ 500 W·h/kg, which is much higher than that of current Li-ion cells (~ 200 W·h/kg). Even after 1500 cycles, we demonstrate a very high specific capacity (~ 740 mA·h/g of sulfur), which corresponds to ~ 414 mA·h/g of electrode: still higher than state-of-the-art Li-ion cells. Moreover, these Li/S cells with lithium metal electrodes can be cycled with an excellent Coulombic efficiency of 96.3% after 1500 cycles, which was enabled by our new formulation of the ionic liquid-based electrolyte. The performance we demonstrate herein suggests that Li/S cells may already be suitable for high-power applications such as power tools. Li/S cells may now provide a substantial opportunity for the development of zero-emission vehicles with a driving range similar to that of gasoline vehicles.

Aerial spray deposition on corn silks applied at high and low spray rates

USDA-ARS?s Scientific Manuscript database

Corn earworm is a major pest of sweet corn, especially when grown organically. Aerial application of insecticides is important for both conventionally- and organically-grown sweet corn production as sweet corn is frequently irrigated to assure return on investment given the high production costs. ...

Pig slurry application and irrigation effects on nitrate leaching in Mediterranean soil lysimeters.

PubMed

Daudén, A; Quílez, D; Vera, M V

2004-01-01

Land application of animal manures, such as pig slurry (PS), is a common practice in intensive-farming agriculture. However, this practice has a pitfall consisting of the loss of nutrients, in particular nitrate, toward water courses. The objective of this study was to evaluate nitrate leaching for three application rates of pig slurry (50, 100, and 200 Mg ha(-1)) and a control treatment of mineral fertilizer (275 kg N ha(-1)) applied to corn grown in 10 drainage lysimeters. The effects of two irrigation regimes (low vs. high irrigation efficiency) were also analyzed. In the first two irrigation events, drainage NO(3)-N concentrations as high as 145 and 69 mg L(-1) were measured in the high and moderate PS rate treatments, respectively, in the low irrigation efficiency treatments. This indicates the fast transformation of the PS ammonium into nitrate and the subsequent leaching of the transformed nitrate. Drainage NO(3)-N concentration and load increased linearly by 0.69 mg NO(3)-N L(-1) and 4.6 kg NO(3)-N ha(-1), respectively, for each 10 kg N ha(-1) applied over the minimum of 275 kg N ha(-1). An increase in irrigation efficiency did not induce a significant increase of leachate concentration and the amount of nitrate leached decreased about 65%. Application of low PS doses before sowing complemented with sidedressing N application and a good irrigation management are the key factors to reduce nitrate contamination of water courses.

The effects of straw or straw-derived gasification biochar applications on soil quality and crop productivity: A farm case study.

PubMed

Hansen, Veronika; Müller-Stöver, Dorette; Imparato, Valentina; Krogh, Paul Henning; Jensen, Lars Stoumann; Dolmer, Anders; Hauggaard-Nielsen, Henrik

2017-01-15

Thermal gasification of straw is a highly efficient technology that produces bioenergy and gasification biochar that can be used as a soil amendment, thereby returning non-renewable nutrients and stable carbon, and securing soil quality and crop productivity. A Danish on-farm field study investigated the impact of traditional straw incorporation vs. straw removal for thermal gasification bioenergy production and the application of straw gasification biochar (GB) on soil quality and crop production. Two rates of GB were applied over three successive years in which the field was cropped with winter wheat (Triticum aestivum L.), winter oilseed rape (Brassica napus L.) and winter wheat, respectively, to assess the potential effects on the soil carbon pool, soil microorganisms, earthworms, soil chemical properties and crop yields. The application of GB did not increase the soil organic carbon content significantly and had no effect on crop yields. The application of straw and GB had a positive effect on the populations of bacteria and protists, but no effect on earthworms. The high rate of GB increased soil exchangeable potassium content and soil pH indicating its potassium bioavailability and liming properties. These results suggest, that recycling GB into agricultural soils has the potential to be developed into a system combining bioenergy generation from agricultural residues and crop production, while maintaining soil quality. However, future studies should be undertaken to assess its long-term effects and to identify the optimum balance between straw removal and biochar application rate. Copyright © 2016. Published by Elsevier Ltd.

A Comparative Study on Ni-Based Coatings Prepared by HVAF, HVOF, and APS Methods for Corrosion Protection Applications

NASA Astrophysics Data System (ADS)

Sadeghimeresht, E.; Markocsan, N.; Nylén, P.

2016-12-01

Selection of the thermal spray process is the most important step toward a proper coating solution for a given application as important coating characteristics such as adhesion and microstructure are highly dependent on it. In the present work, a process-microstructure-properties-performance correlation study was performed in order to figure out the main characteristics and corrosion performance of the coatings produced by different thermal spray techniques such as high-velocity air fuel (HVAF), high-velocity oxy fuel (HVOF), and atmospheric plasma spraying (APS). Previously optimized HVOF and APS process parameters were used to deposit Ni, NiCr, and NiAl coatings and compare with HVAF-sprayed coatings with randomly selected process parameters. As the HVAF process presented the best coating characteristics and corrosion behavior, few process parameters such as feed rate and standoff distance (SoD) were investigated to systematically optimize the HVAF coatings in terms of low porosity and high corrosion resistance. The Ni and NiAl coatings with lower porosity and better corrosion behavior were obtained at an average SoD of 300 mm and feed rate of 150 g/min. The NiCr coating sprayed at a SoD of 250 mm and feed rate of 75 g/min showed the highest corrosion resistance among all investigated samples.

High-speed acoustic communication by multiplexing orbital angular momentum

PubMed Central

Shi, Chengzhi; Dubois, Marc; Wang, Yuan

2017-01-01

Long-range acoustic communication is crucial to underwater applications such as collection of scientific data from benthic stations, ocean geology, and remote control of off-shore industrial activities. However, the transmission rate of acoustic communication is always limited by the narrow-frequency bandwidth of the acoustic waves because of the large attenuation for high-frequency sound in water. Here, we demonstrate a high-throughput communication approach using the orbital angular momentum (OAM) of acoustic vortex beams with one order enhancement of the data transmission rate at a single frequency. The topological charges of OAM provide intrinsically orthogonal channels, offering a unique ability to multiplex data transmission within a single acoustic beam generated by a transducer array, drastically increasing the information channels and capacity of acoustic communication. A high spectral efficiency of 8.0 ± 0.4 (bit/s)/Hz in acoustic communication has been achieved using topological charges between −4 and +4 without applying other communication modulation techniques. Such OAM is a completely independent degree of freedom which can be readily integrated with other state-of-the-art communication modulation techniques like quadrature amplitude modulation (QAM) and phase-shift keying (PSK). Information multiplexing through OAM opens a dimension for acoustic communication, providing a data transmission rate that is critical for underwater applications. PMID:28652341

High-speed bioimaging with frequency-division-multiplexed fluorescence confocal microscopy

NASA Astrophysics Data System (ADS)

Mikami, Hideharu; Harmon, Jeffrey; Ozeki, Yasuyuki; Goda, Keisuke

2017-04-01

We present methods of fluorescence confocal microscopy that enable unprecedentedly high frame rate of > 10,000 fps. The methods are based on a frequency-division multiplexing technique, which was originally developed in the field of communication engineering. Specifically, we achieved a broad bandwidth ( 400 MHz) of detection signals using a dual- AOD method and overcame limitations in frame rate, due to a scanning device, by using a multi-line focusing method, resulting in a significant increase in frame rate. The methods have potential biomedical applications such as observation of sub-millisecond dynamics in biological tissues, in-vivo three-dimensional imaging, and fluorescence imaging flow cytometry.

Diagnostic for a high-repetition rate electron photo-gun and first measurements

NASA Astrophysics Data System (ADS)

Filippetto, D.; Doolittle, L.; Huang, G.; Norum, E.; Portmann, G.; Qian, H.; Sannibale, F.

2015-05-01

The APEX electron source at LBNL combines the high-repetition-rate with the high beam brightness typical of photoguns, delivering low emittance electron pulses at MHz frequency. Proving the high beam quality of the beam is an essential step for the success of the experiment, opening the doors of the high average power to brightness-hungry applications as X-Ray FELs, MHz ultrafast electron diffraction etc.. As first step, a complete characterization of the beam parameters is foreseen at the Gun beam energy of 750 keV. Diagnostics for low and high current measurements have been installed and tested, and measurements of cathode lifetime and thermal emittance in a RF environment with mA current performed. The recent installation of a double slit system, a deflecting cavity and a high precision spectrometer, allow the exploration of the full 6D phase space. Here we discuss the present layout of the machine and future upgrades, showing the latest results at low and high repetition rate, together with the tools and techniques used.

Ablation dynamics - from absorption to heat accumulation/ultra-fast laser matter interaction

NASA Astrophysics Data System (ADS)

Kramer, Thorsten; Remund, Stefan; Jäggi, Beat; Schmid, Marc; Neuenschwander, Beat

2018-05-01

Ultra-short laser radiation is used in manifold industrial applications today. Although state-of-the-art laser sources are providing an average power of 10-100 W with repetition rates of up to several megahertz, most applications do not benefit from it. On the one hand, the processing speed is limited to some hundred millimeters per second by the dynamics of mechanical axes or galvanometric scanners. On the other hand, high repetition rates require consideration of new physical effects such as heat accumulation and shielding that might reduce the process efficiency. For ablation processes, process efficiency can be expressed by the specific removal rate, ablated volume per time, and average power. The analysis of the specific removal rate for different laser parameters, like average power, repetition rate or pulse duration, and process parameters, like scanning speed or material, can be used to find the best operation point for microprocessing applications. Analytical models and molecular dynamics simulations based on the so-called two-temperature model reveal the causes for the appearance of limiting physical effects. The findings of models and simulations can be used to take advantage and optimize processing strategies.

Fine figure correction and other applications using novel MRF fluid designed for ultra-low roughness

NASA Astrophysics Data System (ADS)

Maloney, Chris; Oswald, Eric S.; Dumas, Paul

2015-10-01

An increasing number of technologies require ultra-low roughness (ULR) surfaces. Magnetorheological Finishing (MRF) is one of the options for meeting the roughness specifications for high-energy laser, EUV and X-ray applications. A novel MRF fluid, called C30, has been developed to finish surfaces to ULR. This novel MRF fluid is able to achieve <1.5Å RMS roughness on fused silica and other materials, but has a lower material removal rate with respect to other MRF fluids. As a result of these properties, C30 can also be used for applications in addition to finishing ULR surfaces. These applications include fine figure correction, figure correcting extremely soft materials and removing cosmetic defects. The effectiveness of these new applications is explored through experimental data. The low removal rate of C30 gives MRF the capability to fine figure correct low amplitude errors that are usually difficult to correct with higher removal rate fluids. The ability to figure correct extremely soft materials opens up MRF to a new realm of materials that are difficult to polish. C30 also offers the ability to remove cosmetic defects that often lead to failure during visual quality inspections. These new applications for C30 expand the niche in which MRF is typically used for.

Binder-free cobalt phosphate one-dimensional nanograsses as ultrahigh-performance cathode material for hybrid supercapacitor applications

NASA Astrophysics Data System (ADS)

Sankar, K. Vijaya; Lee, S. C.; Seo, Y.; Ray, C.; Liu, S.; Kundu, A.; Jun, S. C.

2018-01-01

One-dimensional (1D) nanostructure exhibits excellent electrochemical performance because of their unique physico-chemical properties like fast electron transfer, good rate capability, and cyclic stability. In the present study, Co3(PO4)2 1D nanograsses are grown on Ni foam using a simple and eco-friendly hydrothermal technique with different reaction times. The open space with uniform nanograsses displays a high areal capacitance, rate capability, energy density, and cyclic stability due to the nanostructure enhancing fast ion and material interactions. Ex-situ microscope images confirm the dependence of structural stability on the reaction time, and the nanograsses promoted ion interaction through material. Further, the reproducibility of the electrochemical performance confirms the binder-free Co3(PO4)2 1D nanograsses to be a suitable high-performance cathode material for application to hybrid supercapacitor. Finally, the assembled hybrid supercapacitor exhibits a high energy density (26.66 Wh kg-1 at 750 W kg-1) and longer lifetimes (80% retained capacitance after 6000 cycles). Our results suggests that the Co3(PO4)2 1D nanograss design have a great promise for application to hybrid supercapacitor.

[High-Flow Nasal Cannulae (HFNC) in Neonates: A Survey of Current Practice in Level 1 Perinatal Centres in the German State of North Rhine-Westphalia].

PubMed

Hepping, N; Garbe, W; Schneider, K

2015-12-01

High-flow nasal cannulae (HFNC) is a kind of non-invasive respiratory support. In recent years, its application has gained increasing popularity for treating neonates with respiratory failure. Within this study, neonatologists employed at high level perinatal centres within the region of North Rhine-Westphalia, Germany were interviewed. We evaluated their personal experience as well as the underlying indication for using HFNC. We undertook an online survey. 93% of the interviewed participants use HFNC systems in their NICU. The most prominent indications were CPAP-weaning, nasal trauma, and apnoea of prematurity. Both initial flow and maximum and minimum flow rates varied widely. The primary benefit of HFNC vs. conventional CPAP was the improved neonate tolerance, less nasal traumata and ease of application and care. A common disadvantage was the inability to conduct PEEP measurements. The application of the HFNC system is increasing for specific neonatal indications, thereby increasing the data for the evaluation of effectivity and safety. Nevertheless, detailed investigations of the appropriate flow rate settings are still lacking. © Georg Thieme Verlag KG Stuttgart · New York.

A Lemon Cell Battery for High-Power Applications

NASA Astrophysics Data System (ADS)

Muske, Kenneth R.; Nigh, Christopher W.; Weinstein, Randy D.

2007-04-01

This article discusses the development of a lemon cell battery for high-power applications. The target application is the power source of a dc electric motor for a model car constructed by first-year engineering students as part of their introductory course design project and competition. The battery is composed of a series of lemon juice cells made from UV vis cuvets that use a magnesium anode and copper cathode. Dilution of the lemon juice to reduce the rate of corrosion of the magnesium anode and the addition of table salt to reduce the internal resistance of the cell are examined. Although our specific interest is the use of this lemon cell battery to run an electric dc motor, high-power applications such as radios, portable cassette or CD players, and other battery-powered toys are equally appropriate for demonstration and laboratory purposes using this battery.

Combination of biochar amendment and mycoremediation for polycyclic aromatic hydrocarbons immobilization and biodegradation in creosote-contaminated soil.

PubMed

García-Delgado, Carlos; Alfaro-Barta, Irene; Eymar, Enrique

2015-03-21

Soils impregnated with creosote contain high concentrations of polycyclic aromatic hydrocarbons (PAH). To bioremediate these soils and avoid PAH spread, different bioremediation strategies were tested, based on natural attenuation, biochar application, wheat straw biostimulation, Pleurotus ostreatus mycoremediation, and the novel sequential application of biochar for 21 days and P. ostreatus 21 days more. Soil was sampled after 21 and 42 days after the remediation application. The efficiency and effectiveness of each remediation treatment were assessed according to PAH degradation and immobilization, fungal and bacterial development, soil eco-toxicity and legal considerations. Natural attenuation and biochar treatments did not achieve adequate PAH removal and soil eco-toxicity reduction. Biostimulation showed the highest bacterial development but low PAH degradation rate. Mycoremediation achieved the best PAH degradation rate and the lowest bioavailable fraction and soil eco-toxicity. This bioremediation strategy achieved PAH concentrations below Spanish legislation for contaminated soils (RD 9/2005). Sequential application of biochar and P. ostreatus was the second treatment most effective for PAH biodegradation and immobilization. However, the activity of P. ostreatus was increased by previous biochar application and PAH degradation efficiency was increased. Therefore, the combined strategy for PAH degradation have high potential to increase remediation efficiency. Copyright © 2014 Elsevier B.V. All rights reserved.

Results of treatment of choroidal malignant melanoma with high-dose-rate strontium-90 brachytherapy. A retrospective study of 46 patients treated between 1983 and 1995.

PubMed

Missotten, L; Dirven, W; Van der Schueren, A; Leys, A; De Meester, G; Van Limbergen, E

1998-03-01

We review the results of treatment of small to medium-sized choroidal malignant melanomas after high-dose-rate brachytherapy with a strontium-90 applicator. The applicator is positioned against the sclera using an afterloading technique. Brachytherapy is completed in a single session lasting 2-4 h with the patient under local anaesthesia. From September 1983 until March 1995, 46 eyes were treated in this way. Most tumours were 7-11 mm in diameter (range from 4.5-15 mm) with a mean height of approximately 3 mm (range from 1.5-7 mm). Follow-up ranged from 6 months to 12 years (mean 49 months). Thirty of the 46 eyes had at the final evaluation a nonevolutive scar (20 of these after a single application, the others with some additional treatment). In 13 eyes the tumours were in involution but their complete destruction was not yet certain, and 3 eyes were enucleated for local recurrence. Three patients developed systemic metastases. No radiogenic complications were noticed. Strontium-90 brachytherapy is a valuable and safe treatment technique for small to medium-sized choroidal malignant melanomas. In addition the use of a strontium-90 applicator is inexpensive thanks to this element's long half-life and the short application time.

Image-based multichannel vaginal cylinder brachytherapy for the definitive treatment of gynecologic malignancies in the vagina.

PubMed

Gebhardt, Brian J; Vargo, John A; Kim, Hayeon; Houser, Christopher J; Glaser, Scott M; Sukumvanich, Paniti; Olawaiye, Alexander B; Kelley, Joseph L; Edwards, Robert P; Comerci, John T; Courtney-Brooks, Madeleine; Beriwal, Sushil

2018-06-18

Brachytherapy is integral to vaginal cancer treatment and is typically delivered using an intracavitary single-channel vaginal cylinder (SCVC) or an interstitial brachytherapy (ISBT) applicator. Multi-channel vaginal cylinder (MCVC) applicators allow for improved organ-at-risk (OAR) sparing compared to SCVC while maintaining target coverage. We present clinical outcomes of patients treated with image-based high dose-rate (HDR) brachytherapy using a MCVC. Sixty patients with vaginal cancer (27% primary vaginal and 73% recurrence from other primaries) were treated with combination external beam radiotherapy (EBRT) and image-based HDR brachytherapy utilizing a MCVC if residual disease thickness was 7 mm or less after EBRT. All pts received 3D image-based BT to a total equivalent dose of 70-80 Gy. The median high-risk clinical target volume was 24.4 cm 3 (interquartile range [IQR], 14.1), with a median dose to 90% of 77.2 Gy (IQR, 2.8). After a median follow-up of 45 months (range, 11-78), the 4-year local-regional control, distant control, DFS, and OS rates were 92.6%, 76.1%, 64.0%, and 67.2%, respectively. The 4-year LRC rates were similar between the primary vaginal (92%) and recurrent (93%) groups (p = 0.290). Pts with lymph node positive disease had a lower rate of distant control at 4 years (22.7% vs. 89.0%, p < 0.001). There were no Grade 3 or higher acute complications. The 4-year rate of late Grade 3 or higher toxicity was 2.7%. Clinical outcomes of pts with primary and recurrent vaginal cancer treated definitively in a systematic manner with combination EBRT with image-guided HDR BT utilizing a MCVC applicator demonstrate high rates of local control and low rates of severe morbidity. The MCVC technique allows interstitial implantation to be avoided in select pts with ≤7 mm residual disease thickness following EBRT while maintaining excellent clinical outcomes with extended 4-year follow-up in this rare malignancy. Copyright © 2018. Published by Elsevier Inc.

34 CFR 427.22 - What additional factors does the Secretary consider?

Code of Federal Regulations, 2010 CFR

2010-07-01

... highly rated applications are equitably distributed among populations of individuals with limited English... limited English proficiency within a State; or (2) Geographical distribution of projects funded under this...

An Evaluation of Jet Impingement Heat Transfer Correlations for Piccolo Tube Application

NASA Technical Reports Server (NTRS)

Bond, Thomas (Technical Monitor); Wright, William B.

2004-01-01

Impinging jets have been used for a wide variety of applications where high rates of heat transfer are desired. This report will present a review of heat transfer correlations that have been published. The correlations were then added to the LEWICE software to evaluate the applicability of these correlations to a piccolo tube anti-icing system. The results of this analysis were then compared quantitatively to test results on a representative piccolo tube system.

Hydrodechlorination of TCE in a circulated electrolytic column at high flow rate.

PubMed

Fallahpour, Noushin; Yuan, Songhu; Rajic, Ljiljana; Alshawabkeh, Akram N

2016-02-01

Palladium-catalytic hydrodechlorination of trichloroethylene (TCE) by cathodic H2 produced from water electrolysis has been tested. For a field in-well application, the flow rate is generally high. In this study, the performance of Pd-catalytic hydrodechlorination of TCE using cathodic H2 is evaluated under high flow rate (1 L min(-1)) in a circulated column system, as expected to occur in practice. An iron anode supports reduction conditions and it is used to enhance TCE hydrodechlorination. However, the precipitation occurs and high flow rate was evaluated to minimize its adverse effects on the process (electrode coverage, clogging, etc.). Under the conditions of 1 L min(-1) flow, 500 mA current, and 5 mg L(-1) initial TCE concentration, removal efficacy using iron anodes (96%) is significantly higher than by mixed metal oxide (MMO) anodes (66%). Two types of cathodes (MMO and copper foam) in the presence of Pd/Al2O3 catalyst under various currents (250, 125, and 62 mA) were used to evaluate the effect of cathode materials on TCE removal efficacy. The similar removal efficiencies were achieved for both cathodes, but more precipitation generated with copper foam cathode (based on the experiments done by authors). In addition to the well-known parameters such as current density, electrode materials, and initial TCE concentration, the high velocities of groundwater flow can have important implications, practically in relation to the flush out of precipitates. For potential field application, a cost-effective and sustainable in situ electrochemical process using a solar panel as power supply is being evaluated. Published by Elsevier Ltd.

Hydrodechlorination of TCE in a circulated electrolytic column at high flow rate

PubMed Central

Fallahpour, Noushin; Yuan, Songhu; Rajic, Ljiljana; Alshawabkeh, Akram N.

2015-01-01

Palladium-catalytic hydrodechlorination of trichloroethylene (TCE) by cathodic H2 produced from water electrolysis has been tested. For a field in-well application, the flow rate is generally high. In this study, the performance of Pd-catalytic hydrodechlorination of TCE using cathodic H2 is evaluated under high flow rate (1 L min−1) in a circulated column system, as expected to occur in practice. An iron anode supports reduction conditions and it is used to enhance TCE hydrodechlorination. However, the precipitation occurs and high flow rate was evaluated to minimize its advers effects on the process (electrode coverage, clogging, etc.). Under the conditions of 1 L min−1 flow, 500 mA current, and 5 mg L−1 initial TCE concentration, removal efficacy using iron anodes (96%) is significantly higher than by mixed metal oxide (MMO) anodes (66%). Two types of cathodes (MMO and copper foam) in the presence of Pd/Al2O3 catalyst under various currents (250, 125, and 62 mA) were used to evaluate the effect of cathode materials on TCE removal efficacy. The similar removal efficiencies were achieved for both cathodes, but more precipitation generated with copper foam cathode (based on the experiments done by authors). In addition to the well-known parameters such as current density, electrode materials, and initial TCE concentration, the high velocities of groundwater flow can have important implications, practically in relation to the flush out of precipitates. For potential field application, a cost-effective and sustainable in situ electrochemical process using a solar panel as power supply is being evaluated. PMID:26344148

Exploring a suitable nitrogen fertilizer rate to reduce greenhouse gas emissions and ensure rice yields in paddy fields.

PubMed

Zhong, Yiming; Wang, Xiaopeng; Yang, Jingping; Zhao, Xing; Ye, Xinyi

2016-09-15

The application rate of nitrogen fertilizer was believed to dramatically influence greenhouse gas (GHG) emissions from paddy fields. Thus, providing a suitable nitrogen fertilization rate to ensure rice yields, reducing GHG emissions and exploring emission behavior are important issues for field management. In this paper, a two year experiment with six rates (0, 75, 150, 225, 300, 375kgN/ha) of nitrogen fertilizer application was designed to examine GHG emissions by measuring carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) flux and their cumulative global warming potential (GWP) from paddy fields in Hangzhou, Zhejiang in 2013 and 2014. The results indicated that the GWP and rice yields increased with an increasing application rate of nitrogen fertilizer. Emission peaks of CH4 mainly appeared at the vegetative phase, and emission peaks of CO2, and N2O mainly appeared at reproductive phase of rice growth. The CO2 flux was significantly correlated with soil temperature, while the CH4 flux was influenced by logging water remaining period and N2O flux was significantly associated with nitrogen application rates. This study showed that 225kgN/ha was a suitable nitrogen fertilizer rate to minimize GHG emissions with low yield-scaled emissions of 3.69 (in 2013) and 2.23 (in 2014) kg CO2-eq/kg rice yield as well as to ensure rice yields remained at a relatively high level of 8.89t/ha in paddy fields. Copyright © 2016 Elsevier B.V. All rights reserved.

A Portable Dynamic Laser Speckle System for Sensing Long-Term Changes Caused by Treatments in Painting Conservation.

PubMed

Pérez, Alberto J; González-Peña, Rolando J; Braga, Roberto; Perles, Ángel; Pérez-Marín, Eva; García-Diego, Fernando J

2018-01-11

Dynamic laser speckle (DLS) is used as a reliable sensor of activity for all types of materials. Traditional applications are based on high-rate captures (usually greater than 10 frames-per-second, fps). Even for drying processes in conservation treatments, where there is a high level of activity in the first moments after the application and slower activity after some minutes or hours, the process is based on the acquisition of images at a time rate that is the same in moments of high and low activity. In this work, we present an alternative approach to track the drying process of protective layers and other painting conservation processes that take a long time to reduce their levels of activity. We illuminate, using three different wavelength lasers, a temporary protector (cyclododecane) and a varnish, and monitor them using a low fps rate during long-term drying. The results are compared to the traditional method. This work also presents a monitoring method that uses portable equipment. The results present the feasibility of using the portable device and show the improved sensitivity of the dynamic laser speckle when sensing the long-term process for drying cyclododecane and varnish in conservation.

Limitations of the Conventional Phase Advance Method for Constant Power Operation of the Brushless DC Motor

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

Lawler, J.S.

2001-10-29

The brushless dc motor (BDCM) has high-power density and efficiency relative to other motor types. These properties make the BDCM well suited for applications in electric vehicles provided a method can be developed for driving the motor over the 4 to 6:1 constant power speed range (CPSR) required by such applications. The present state of the art for constant power operation of the BDCM is conventional phase advance (CPA) [1]. In this paper, we identify key limitations of CPA. It is shown that the CPA has effective control over the developed power but that the current magnitude is relatively insensitivemore » to power output and is inversely proportional to motor inductance. If the motor inductance is low, then the rms current at rated power and high speed may be several times larger than the current rating. The inductance required to maintain rms current within rating is derived analytically and is found to be large relative to that of BDCM designs using high-strength rare earth magnets. Th us, the CPA requires a BDCM with a large equivalent inductance.« less

High repetition rate laser-driven MeV ion acceleration at variable background pressures

NASA Astrophysics Data System (ADS)

Snyder, Joseph; Ngirmang, Gregory; Orban, Chris; Feister, Scott; Morrison, John; Frische, Kyle; Chowdhury, Enam; Roquemore, W. M.

2017-10-01

Ultra-intense laser-plasma interactions (LPI) can produce highly energetic photons, electrons, and ions with numerous potential real-world applications. Many of these applications will require repeatable, high repetition targets that are suitable for LPI experiments. Liquid targets can meet many of these needs, but they typically require higher chamber pressure than is used for many low repetition rate experiments. The effect of background pressure on the LPI has not been thoroughly studied. With this in mind, the Extreme Light group at the Air Force Research Lab has carried out MeV ion and electron acceleration experiments at kHz repetition rate with background pressures ranging from 30 mTorr to >1 Torr using a submicron ethylene glycol liquid sheet target. We present these results and provide two-dimensional particle-in-cell simulation results that offer insight on the thresholds for the efficient acceleration of electrons and ions. This research is supported by the Air Force Office of Scientific Research under LRIR Project 17RQCOR504 under the management of Dr. Riq Parra and Dr. Jean-Luc Cambier. Support was also provided by the DOD HPCMP Internship Program.

Low-Temperature and Rapid Growth of Large Single-Crystalline Graphene with Ethane.

PubMed

Sun, Xiao; Lin, Li; Sun, Luzhao; Zhang, Jincan; Rui, Dingran; Li, Jiayu; Wang, Mingzhan; Tan, Congwei; Kang, Ning; Wei, Di; Xu, H Q; Peng, Hailin; Liu, Zhongfan

2018-01-01

Future applications of graphene rely highly on the production of large-area high-quality graphene, especially large single-crystalline graphene, due to the reduction of defects caused by grain boundaries. However, current large single-crystalline graphene growing methodologies are suffering from low growth rate and as a result, industrial graphene production is always confronted by high energy consumption, which is primarily caused by high growth temperature and long growth time. Herein, a new growth condition achieved via ethane being the carbon feedstock to achieve low-temperature yet rapid growth of large single-crystalline graphene is reported. Ethane condition gives a growth rate about four times faster than methane, achieving about 420 µm min -1 for the growth of sub-centimeter graphene single crystals at temperature about 1000 °C. In addition, the temperature threshold to obtain graphene using ethane can be reduced to 750 °C, lower than the general growth temperature threshold (about 1000 °C) with methane on copper foil. Meanwhile ethane always keeps higher graphene growth rate than methane under the same growth temperature. This study demonstrates that ethane is indeed a potential carbon source for efficient growth of large single-crystalline graphene, thus paves the way for graphene in high-end electronical and optoelectronical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dissipation rate of thiacloprid and its control effect against Bemisia tabaci in greenhouse tomato after soil application.

PubMed

Dong, Sa; Qiao, Kang; Wang, Hongyan; Zhu, Yukun; Xia, Xiaoming; Wang, Kaiyun

2014-08-01

Thiacloprid is a chloronicotinyl insecticide that is quite effective against sucking insects. In this study, when thiacloprid was applied at two different rates (normal rate 15 kg ha(-1) , double rate 30 kg ha(-1) ), the systemic distribution and residue of thiacloprid as well as its control effect against whitefly (Bemisia tabaci) were investigated in greenhouse tomato after soil application. The results showed that thiacloprid was present in the tomato leaves until day 25, and then its amount was less than 0.005 mg kg(-1) and could not be detected. Thiacloprid residue in the tomato stems basically remained at a stable low level throughout the experimental period. Thiacloprid in soil had half-lives of 11.8 and 12.5 days for the normal treatment and the double treatment respectively. The control efficiency of whiteflies was about 90% from day 1 to day 10. This was followed by a slow decline, but efficiency was still higher than 50% until day 21. In addition, no significant differences were noted in the control effect of thiacloprid on whiteflies between the two different rates. Soil application of thiacloprid at the normal rate can effectively control whiteflies, with high efficiency and long persistence. © 2013 Society of Chemical Industry.

Meta-analysis on the Safety and Efficacy of the Reperfusion Use of a Single High Dose of Anti-T-Lymphocyte Globulin Fresenius in Kidney Transplantation.

PubMed

Du, X; Wang, W; Sun, Z-J; Su, L L; Zhang, X-D

2016-01-01

The aim of this study was to evaluate the effects of a single high dose of the anti-T-lymphocyte globulin Fresenius (ATG-F), given before kidney transplantation, on the prevention of acute rejection response and infections and on the survival rate of the renal graft and patient. Databases including PubMed, Embase, and the Cochrane Library were searched to identify randomized controlled trials relevant to studying the presurgical use of a single high dose of ATG-F. Five RCTs that included 346 patients were selected. The meta-analysis suggested that the application of ATG-F reduced the postsurgical acute rejection reaction incidence compared to that of the control group (relative risk = 0.50, 95% confidence interval = 0.35-0.71, P = .0001). However, the application of ATG-F exhibited no significant effect on the incidence of urinary tract infection, cytomegalovirus infection, and delayed graft function. Furthermore, the one-year patient survival rate and kidney graft survival rate were not affected. The meta-analysis suggested that the reperfusion use of a single high dose (9 mg/kg) of ATG-F could effectively reduce the incidence of postsurgical acute rejection response without affecting the occurrence of infections, the survival rates of kidney grafts and patients, or the incidence of delayed graft function. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Applicant Interview Experiences and Postinterview Communication of the 2016 Radiation Oncology Match Cycle

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

Berriochoa, Camille; Ward, Matthew C.; Weller, Michael A.

Purpose: To characterize applicant interview experiences at radiation oncology residency programs during the 2016 match cycle and to assess applicant opinions regarding postinterview communication (PIC) after recent attention to gamesmanship noted in prior match cycles. Methods and Materials: An anonymous, institutional review board–approved, 29-question survey was deployed following the rank order list deadline to all 2016 radiation oncology residency applicants applying to a single institution. Results: Complete surveys were returned by 118 of 210 applicants, for a 56% response rate. Regarding possible match violation questions, 84% of respondents were asked at least once about where else they were interviewing (occurredmore » at a median of 20% of program interviews); 51% were asked about marital status (6% of interviews); and 22% were asked about plans to have children (1% of interviews). Eighty-three percent of applicants wrote thank-you notes, with 55% reporting fear of being viewed unfavorably if such notes were not communicated. Sixty percent of applicants informed a program that they had ranked a program highly; 53% felt this PIC strategy would improve their standing on the rank order list, yet 46% reported feeling distressed by this obligation. A majority of applicants stated that they would feel relieved if programs explicitly discouraged PIC (89%) and that it would be preferable if programs prohibited applicants from notifying the program of their rank position (66%). Conclusions: Potential match violations occur at a high rate but are experienced at a minority of interviews. Postinterview communication occurs frequently, with applicants reporting resultant distress. Respondents stated that active discouragement of both thank-you notes/e-mails and applicants' notification to programs of their ranking would be preferred.« less

Impacts and Viability of Open Source Software on Earth Science Metadata Clearing House and Service Registry Applications

NASA Astrophysics Data System (ADS)

Pilone, D.; Cechini, M. F.; Mitchell, A.

2011-12-01

Earth Science applications typically deal with large amounts of data and high throughput rates, if not also high transaction rates. While Open Source is frequently used for smaller scientific applications, large scale, highly available systems frequently fall back to "enterprise" class solutions like Oracle RAC or commercial grade JEE Application Servers. NASA's Earth Observing System Data and Information System (EOSDIS) provides end-to-end capabilities for managing NASA's Earth science data from multiple sources - satellites, aircraft, field measurements, and various other programs. A core capability of EOSDIS, the Earth Observing System (EOS) Clearinghouse (ECHO), is a highly available search and order clearinghouse of over 100 million pieces of science data that has evolved from its early R&D days to a fully operational system. Over the course of this maturity ECHO has largely transitioned from commercial frameworks, databases, and operating systems to Open Source solutions...and in some cases, back. In this talk we discuss the progression of our technological solutions and our lessons learned in the areas of: ? High performance, large scale searching solutions ? GeoSpatial search capabilities and dealing with multiple coordinate systems ? Search and storage of variable format source (science) data ? Highly available deployment solutions ? Scalable (elastic) solutions to visual searching and image handling Throughout the evolution of the ECHO system we have had to evaluate solutions with respect to performance, cost, developer productivity, reliability, and maintainability in the context of supporting global science users. Open Source solutions have played a significant role in our architecture and development but several critical commercial components remain (or have been reinserted) to meet our operational demands.

Applications of high pressure differential scanning calorimetry to aviation fuel thermal stability research

NASA Technical Reports Server (NTRS)

Neveu, M. C.; Stocker, D. P.

1985-01-01

High pressure differential scanning calorimetry (DSC) was studied as an alternate method for performing high temperature fuel thermal stability research. The DSC was used to measure the heat of reaction versus temperature of a fuel sample heated at a programmed rate in an oxygen pressurized cell. Pure hydrocarbons and model fuels were studied using typical DSC operating conditions of 600 psig of oxygen and a temperature range from ambient to 500 C. The DSC oxidation onset temperature was determined and was used to rate the fuels on thermal stability. Kinetic rate constants were determined for the global initial oxidation reaction. Fuel deposit formation is measured, and the high temperature volatility of some tetralin deposits is studied by thermogravimetric analysis. Gas chromatography and mass spectrometry are used to study the chemical composition of some DSC stressed fuels.

Proposal for grid computing for nuclear applications

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

Idris, Faridah Mohamad; Ismail, Saaidi; Haris, Mohd Fauzi B.

2014-02-12

The use of computer clusters for computational sciences including computational physics is vital as it provides computing power to crunch big numbers at a faster rate. In compute intensive applications that requires high resolution such as Monte Carlo simulation, the use of computer clusters in a grid form that supplies computational power to any nodes within the grid that needs computing power, has now become a necessity. In this paper, we described how the clusters running on a specific application could use resources within the grid, to run the applications to speed up the computing process.

Application specific serial arithmetic arrays

NASA Technical Reports Server (NTRS)

Winters, K.; Mathews, D.; Thompson, T.

1990-01-01

High performance systolic arrays of serial-parallel multiplier elements may be rapidly constructed for specific applications by applying hardware description language techniques to a library of full-custom CMOS building blocks. Single clock pre-charged circuits have been implemented for these arrays at clock rates in excess of 100 Mhz using economical 2-micron (minimum feature size) CMOS processes, which may be quickly configured for a variety of applications. A number of application-specific arrays are presented, including a 2-D convolver for image processing, an integer polynomial solver, and a finite-field polynomial solver.

Variable rate application of nematicides on cotton fields: a promising site-specific management strategy.

PubMed

Ortiz, Brenda V; Perry, Calvin; Sullivan, Dana; Lu, Ping; Kemerait, Robert; Davis, Richard F; Smith, Amanda; Vellidis, George; Nichols, Robert

2012-03-01

Field tests were conducted to determine if differences in response to nematicide application (i.e., root-knot nematode (RKN) populations, cotton yield, and profitability) occurred among RKN management zones (MZ). The MZ were delineated using fuzzy clustering of five terrain (TR) and edaphic (ED) field features related to soil texture: apparent soil electrical conductivity shallow (ECa-shallow) and deep (ECa-deep), elevation (EL), slope (SL), and changes in bare soil reflectance. Zones with lowest mean values of ECa- shallow, ECa- deep, NDVI, and SL were designated as at greater risk for high RKN levels. Nematicide-treated plots (4 rows wide and 30 m long) were established in a randomized complete block design within each zone, but the number of replications in each zone varied from four to six depending on the size of the zone.The nematicides aldicarb (Temik 15 G) and 1,3-dichloropropene (1,3-D,Telone II) were applied at two rates (0.51 and 1.0 kg a.i./ha for aldicarb, and 33.1 and 66.2 kg a.i./ha for 1,3-D) to RKN MZ in commercial fields between 2007 and 2009. A consolidated analysis over the entire season showed that regardless of the zone, there were not differences between aldicarb rates and 1,3-D rates. The result across zones showed that 1,3-D provided better RKN control than did aldicarb in zones with low ECa values (high RKN risk zones exhibiting more coarse-textured sandy soils). In contrast, in low risk zones with relatively higher ECa values (heavier textured soil), the effects of 1,3-D and aldicarb were equal and application of any of the treatments provided sufficient control. In low RKN risk zones, a farmer would often have lost money if a high rate of 1,3-D was applied. This study showed that the effect of nematicide type and rate on RKN control and cotton yield varied across management zones (MZ) with the most expensive treatment likely to provide economic benefit only in zones with coarser soil texture. This study demonstrates the value of site specific application of nematicides based on management zones, although this approach might not be economically beneficial in fields with little variability in soil texture.

Single-arm trial of the second version of an acceptance & commitment therapy smartphone application for smoking cessation.

PubMed

Bricker, Jonathan B; Copeland, Wade; Mull, Kristin E; Zeng, Emily Y; Watson, Noreen L; Akioka, Katrina J; Heffner, Jaimee L

2017-01-01

The first randomized trial of a smartphone application (app) for adult smoking cessation (SmartQuit 1.0) revealed key features that predict cessation. These findings guided the revision of this Acceptance & Commitment Therapy (ACT)-based application (SmartQuit 2.0), which was primarily tested to examine participant receptivity, short-term cessation and reduction, and the relationship between program completion, smoking cessation and reduction. Secondarily, outcomes were descriptively compared with the SmartQuit1.0 trial. Adult participants (78% female, 25% with high school or less education, 30% unemployed) were recruited into the single-arm pilot trial (N=99) of SmartQuit 2.0 with a two-month follow-up (85% retention). Regarding receptivity, 84% of participants were satisfied with SmartQuit 2.0 (vs. 59% for SmartQuit1.0), 73% would recommend it to a friend (vs. 48% for SmartQuit1.0), 81% found the ACT exercises useful for quitting (vs. 44% for SmartQuit1.0). At the 2-month follow-up, the quit rates were 21% for 7-day point prevalence (vs. 23% for SmartQuit1.0), 11% for 30-day point prevalence (vs. 13% for SmartQuit1.0), and 75% of participants reduced their smoking frequency (vs. 57% for SmartQuit1.0). Among program completers (24% of total sample), the quit rates were 33% for 7-day point prevalence, 28% for 30-day point prevalence, and 88% of participants reduced their smoking frequency. The revised app had high user receptivity, modest quit rates, and high smoking reduction rates. Program completion may be key to boosting the app's effectiveness. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Texture studies of hot compressed near alpha titanium alloy (IMI 834) at 1000°C with different strain rates

NASA Astrophysics Data System (ADS)

Kodli, B. K.; Saxena, K. K.; Dey, S. R.; Pancholi, V.; Bhattacharjee, A.

2015-04-01

IMI 834 Titanium alloy is a near alpha (hcp) titanium alloy used for high temperature applications with the service temperature up to 600°C. Generally, this alloy is widely used in gas turbine engine applications such as low pressure compressor discs. For these applications, good fatigue and creep properties are required, which have been noticed better in a bimodal microstructure, containing 15-20% volume fraction of primary alpha grains (αp) and remaining bcc beta (β) grains transformed secondary alpha laths (αs). The bimodal microstructure is achieved during processing of IMI 834 in the high temperature α+β region. The major issue of bimodal IMI 834 during utilization is its poor dwell fatigue life time caused by textured macrozones. Textured macrozone is the spatial accumulation of similar oriented grains in the microstructure generated during hot processing in the high temperature α+β region. Textured macrozone can be mitigated by controlling the hot deformation with certain strain rate under stable plastic conditions having β grains undergoing dynamic recrystallization. Hence, a comprehensive study is required to understand the deformation behavior of α and β grains at different strain rates in that region. Hot compression tests up to 5°% strain of the samples are performed with five different strain rates i.e. 10-3 s-1, 10-2 s-1, 10-1 s-1, 1 s-1 and 10 s-1 at 1000°C using Gleeble 3800. The resultant bimodal microstructure and the texture studies of primary alpha grains (αp) and secondary alpha laths (αs) are carried out using scanning electron microscopy (SEM)-electron back scattered diffraction (EBSD) method.

Persistence of Bidrin® in Two Forest Soils

Treesearch

Richard A. Werner

1970-01-01

A field study conducted on two forest soils, mineral and organic, indicated that high residues of the systemic insecticide Bidrin® were present in the upper 6 inches of soil for only 15 days following application. The rate of downward movement of the insecticide was fastest in the mineral soil. The total residue level during a 90-day period following application was...

34 CFR 75.219 - Exceptions to the procedures under § 75.217.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 1 2014-07-01 2014-07-01 false Exceptions to the procedures under § 75.217. 75.219... under the procedures in § 75.217; (b)(1) The application was evaluated under the preceding competition of the program; (2) The application rated high enough to deserve selection under § 75.217; and (3...

CMOS Image Sensors for High Speed Applications.

PubMed

El-Desouki, Munir; Deen, M Jamal; Fang, Qiyin; Liu, Louis; Tse, Frances; Armstrong, David

2009-01-01

Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4∼5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps).

Multi-gigahertz repetition rate passively modelocked fiber lasers using carbon nanotubes.

PubMed

Martinez, Amos; Yamashita, Shinji

2011-03-28

There is an increasing demand for all-fiber passively mode-locked lasers with pulse repetition rates in the order of gigahertz for their potential applications in fields such as telecommunications and metrology. However, conventional mode-locked fiber lasers typically operate at fundamental repetition rates of only a few megahertz. In this paper, we report all-fiber laser operation with fundamental repetition rates of 4.24 GHz, 9.63 GHz and 19.45 GHz. This is, to date and to the best of our knowledge, the highest fundamental repetition rate reported for an all-fiber laser. The laser operation is based on the passive modelocking of a miniature all-fiber Fabry-Pérot laser (FFPL) by a carbon nanotube (CNT) saturable absorber. The key components for such device are a very high-gain Er:Yb phosphosilicate fiber and a fiber compatible saturable absorber with very small foot print and very low losses. The laser output of the three lasers was close to transform-limited with a pulsewidth of approximately 1 ps and low noise. As a demonstration of potential future applications for this laser, we also demonstrated supercontinuum generation with a longitudinal mode-spacing of 0.08 nm by launching the laser operating at 9.63 GHz into 30 m of a highly nonlinear dispersion shifted fiber.

Flexible asymmetric supercapacitors with high energy and high power density in aqueous electrolytes.

PubMed

Cheng, Yingwen; Zhang, Hongbo; Lu, Songtao; Varanasi, Chakrapani V; Liu, Jie

2013-02-07

Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO(2), activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s(-1) to 500 mV s(-1). Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg(-1)) under high power density (7.8 kW kg(-1)) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required.

The High-efficiency LED Driver for Visible Light Communication Applications.

PubMed

Gong, Cihun-Siyong Alex; Lee, Yu-Chen; Lai, Jyun-Liang; Yu, Chueh-Hao; Huang, Li Ren; Yang, Chia-Yen

2016-08-08

This paper presents a LED driver for VLC. The main purpose is to solve the low data rate problem used to be in switching type LED driver. The GaN power device is proposed to replace the traditional silicon power device of switching LED driver for the purpose of increasing switching frequency of converter, thereby increasing the bandwidth of data transmission. To achieve high efficiency, the diode-connected GaN power transistor is utilized to replace the traditional ultrafast recovery diode used to be in switching type LED driver. This work has been experimentally evaluated on 350-mA output current. The results demonstrate that it supports the data of PWM dimming level encoded in the PPM scheme for VLC application. The experimental results also show that system's efficiency of 80.8% can be achieved at 1-Mb/s data rate.

Biocorrosion properties of antibacterial Ti-10Cu sintered alloy in several simulated biological solutions.

PubMed

Liu, Cong; Zhang, Erlin

2015-03-01

Ti-10Cu sintered alloy has shown strong antibacterial properties against S. aureus and E. coli and good cell biocompatibility, which displays potential application in dental application. The corrosion behaviors of the alloy in five different simulated biological solutions have been investigated by electrochemical technology, surface observation, roughness measurement and immersion test. Five different simulated solutions were chosen to simulate oral condition, oral condition with F(-) ion, human body fluids with different pH values and blood system. It has been shown that Ti-10Cu alloy exhibits high corrosion rate in Saliva pH 3.5 solution and Saliva pH 6.8 + 0.2F solution but low corrosion rate in Hank's, Tyrode's and Saliva pH 6.8 solutions. The corrosion rate of Ti-10Cu alloy was in a order of Hank's, Tyrode's, Saliva pH 6.8, Saliva-pH 3.5 and Saliva pH 6.8 + 0.2F from slow to fast. All results indicated acid and F(-) containing conditions prompt the corrosion reaction of Ti-Cu alloy. It was suggested that the Cu ion release in the biological environments, especially in the acid and F(-) containing condition would lead to high antibacterial properties without any cell toxicity, displaying wide potential application of this alloy.

Modeled nitrous oxide emissions from corn fields in Iowa based on county level data

USDA-ARS?s Scientific Manuscript database

The US Corn Belt area has the capacity to generate high nitrous oxide (N2O) emissions due to medium to high annual precipitation, medium to heavy textured soils rich in organic matter, and high nitrogen (N) application rates. The purpose of this work was to estimate field N2O emissions from cornfiel...

Study of Creep of Alumina-Forming Austenitic Stainless Steel for High-Temperature Energy Applications

NASA Astrophysics Data System (ADS)

Afonina, Natalie Petrovna

To withstand the high temperature (>700°C) and pressure demands of steam turbines and boilers used for energy applications, metal alloys must be economically viable and have the necessary material properties, such as high-temperature creep strength, oxidation and corrosion resistance, to withstand such conditions. One promising class of alloys potentially capable of withstanding the rigors of aggressive environments, are alumina-forming austenitic stainless steels (AFAs) alloyed with aluminum to improve corrosion and oxidation resistance. The effect of aging on the microstructure, high temperature constant-stress creep behavior and mechanical properties of the AFA-type alloy Fe-20Cr-30Ni-2Nb-5Al (at.%) were investigated in this study. The alloy's microstructural evolution with increased aging time was observed prior to creep testing. As aging time increased, the alloy exhibited increasing quantities of fine Fe2Nb Laves phase dispersions, with a precipitate-free zone appearing in samples with higher aging times. The presence of the L1 2 phase gamma'-Ni3Al precipitate was detected in the alloy's matrix at 760°C. A constant-stress creep rig was designed, built and its operation validated. Constant-stress creep tests were performed at 760°C and 35MPa, and the effects of different aging conditions on creep rate were investigated. Specimens aged for 240 h exhibited the highest creep rate by a factor of 5, with the homogenized sample having the second highest rate. Samples aged for 2.4 h and 24 h exhibited similar low secondary creep rates. Creep tests conducted at 700oC exhibited a significantly lower creep rate compared to those at 760oC. Microstructural analysis was performed on crept samples to explore high temperature straining properties. The quantity and size of Fe2Nb Laves phase and NiAl particles increased in the matrix and on grain boundaries with longer aging time. High temperature tensile tests were performed and compared to room temperature results. The high temperature results were significantly lower when compared to room temperature values. Higher creep rates were correlated with lower yield strengths.

Nanoporous metal/oxide hybrid electrodes for electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Lang, Xingyou; Hirata, Akihiko; Fujita, Takeshi; Chen, Mingwei

2011-04-01

Electrochemical supercapacitors can deliver high levels of electrical power and offer long operating lifetimes, but their energy storage density is too low for many important applications. Pseudocapacitive transition-metal oxides such as MnO2 could be used to make electrodes in such supercapacitors, because they are predicted to have a high capacitance for storing electrical charge while also being inexpensive and not harmful to the environment. However, the poor conductivity of MnO2 (10-5-10-6 S cm-1) limits the charge/discharge rate for high-power applications. Here, we show that hybrid structures made of nanoporous gold and nanocrystalline MnO2 have enhanced conductivity, resulting in a specific capacitance of the constituent MnO2 (~1,145 F g-1) that is close to the theoretical value. The nanoporous gold allows electron transport through the MnO2, and facilitates fast ion diffusion between the MnO2 and the electrolytes while also acting as a double-layer capacitor. The high specific capacitances and charge/discharge rates offered by such hybrid structures make them promising candidates as electrodes in supercapacitors, combining high-energy storage densities with high levels of power delivery.

Nanoporous metal/oxide hybrid electrodes for electrochemical supercapacitors.

PubMed

Lang, Xingyou; Hirata, Akihiko; Fujita, Takeshi; Chen, Mingwei

2011-04-01

Electrochemical supercapacitors can deliver high levels of electrical power and offer long operating lifetimes, but their energy storage density is too low for many important applications. Pseudocapacitive transition-metal oxides such as MnO(2) could be used to make electrodes in such supercapacitors, because they are predicted to have a high capacitance for storing electrical charge while also being inexpensive and not harmful to the environment. However, the poor conductivity of MnO(2) (10(-5)-10(-6) S cm(-1)) limits the charge/discharge rate for high-power applications. Here, we show that hybrid structures made of nanoporous gold and nanocrystalline MnO(2) have enhanced conductivity, resulting in a specific capacitance of the constituent MnO(2) (~1,145 F g(-1)) that is close to the theoretical value. The nanoporous gold allows electron transport through the MnO(2), and facilitates fast ion diffusion between the MnO(2) and the electrolytes while also acting as a double-layer capacitor. The high specific capacitances and charge/discharge rates offered by such hybrid structures make them promising candidates as electrodes in supercapacitors, combining high-energy storage densities with high levels of power delivery.

Performance evaluation of a direct-conversion flat-panel detector system in imaging and quality assurance for a high-dose-rate 192Ir source

NASA Astrophysics Data System (ADS)

Miyahara, Yoshinori; Hara, Yuki; Nakashima, Hiroto; Nishimura, Tomonori; Itakura, Kanae; Inomata, Taisuke; Kitagaki, Hajime

2018-03-01

In high-dose-rate (HDR) brachytherapy, a direct-conversion flat-panel detector (d-FPD) clearly depicts a 192Ir source without image halation, even under the emission of high-energy gamma rays. However, it was unknown why iridium is visible when using a d-FPD. The purpose of this study was to clarify the reasons for visibility of the source core based on physical imaging characteristics, including the modulation transfer functions (MTF), noise power spectral (NPS), contrast transfer functions, and linearity of d-FPD to high-energy gamma rays. The acquired data included: x-rays, [X]; gamma rays, [γ] dual rays (X  +  γ), [D], and subtracted data for depicting the source ([D]  -  [γ]). In the quality assurance (QA) test for the positional accuracy of a source core, the coordinates of each dwelling point were compared between the planned and actual source core positions using a CT/MR-compatible ovoid applicator and a Fletcher-Williamson applicator. The profile curves of [X] and ([D]  -  [γ]) matched well on MTF and NPS. The contrast resolutions of [D] and [X] were equivalent. A strongly positive linear correlation was found between the output data of [γ] and source strength (r 2  >  0.99). With regard to the accuracy of the source core position, the largest coordinate difference (3D distance) was noted at the maximum curvature of the CT/MR-compatible ovoid and Fletcher-Williamson applicators, showing 1.74  ±  0.02 mm and 1.01  ±  0.01 mm, respectively. A d-FPD system provides high-quality images of a source, even when high-energy gamma rays are emitted to the detector, and positional accuracy tests with clinical applicators are useful in identifying source positions (source movements) within the applicator for QA.

Parametric studies on droplet generation reproducibility for applications with biological relevant fluids

PubMed Central

Eichler, Marko; Römer, Robert; Grodrian, Andreas; Lemke, Karen; Nagel, Krees; Klages, Claus‐Peter; Gastrock, Gunter

2017-01-01

Abstract Although the great potential of droplet based microfluidic technologies for routine applications in industry and academia has been successfully demonstrated over the past years, its inherent potential is not fully exploited till now. Especially regarding to the droplet generation reproducibility and stability, two pivotally important parameters for successful applications, there is still a need for improvement. This is even more considerable when droplets are created to investigate tissue fragments or cell cultures (e.g. suspended cells or 3D cell cultures) over days or even weeks. In this study we present microfluidic chips composed of a plasma coated polymer, which allow surfactants‐free, highly reproducible and stable droplet generation from fluids like cell culture media. We demonstrate how different microfluidic designs and different flow rates (and flow rate ratios) affect the reproducibility of the droplet generation process and display the applicability for a wide variety of bio(techno)logically relevant media. PMID:29399017

Synchronization of random bit generators based on coupled chaotic lasers and application to cryptography.

PubMed

Kanter, Ido; Butkovski, Maria; Peleg, Yitzhak; Zigzag, Meital; Aviad, Yaara; Reidler, Igor; Rosenbluh, Michael; Kinzel, Wolfgang

2010-08-16

Random bit generators (RBGs) constitute an important tool in cryptography, stochastic simulations and secure communications. The later in particular has some difficult requirements: high generation rate of unpredictable bit strings and secure key-exchange protocols over public channels. Deterministic algorithms generate pseudo-random number sequences at high rates, however, their unpredictability is limited by the very nature of their deterministic origin. Recently, physical RBGs based on chaotic semiconductor lasers were shown to exceed Gbit/s rates. Whether secure synchronization of two high rate physical RBGs is possible remains an open question. Here we propose a method, whereby two fast RBGs based on mutually coupled chaotic lasers, are synchronized. Using information theoretic analysis we demonstrate security against a powerful computational eavesdropper, capable of noiseless amplification, where all parameters are publicly known. The method is also extended to secure synchronization of a small network of three RBGs.

Triaxial X-Ray Diffraction Method and its Application to Monitor Residual Stress in Surface Layers after High-Feed Milling

NASA Astrophysics Data System (ADS)

Zaušková, Lucia; Czán, Andrej; Šajgalík, Michal; Pobijak, Jozef; Mikloš, Matej

2017-10-01

High-feed milling is a milling method characteristic with shallow depth of cut and high feed rate to maximize the amount of removed metal from a part, generating residual stresses in the surface and subsurface layers of the machined parts. The residual stress has a large influence on the functional properties of the components. The article is focused on the application of triaxial x-ray diffraction method to monitor residual stresses after high feed milling. Significance of triaxial measuring method is the capability of measuring in different angles so it is possible to acquire stress tensor containing normal and shear stress components.

A Review of In Situ Observations of Crystallization and Growth in High Temperature Oxide Melts

NASA Astrophysics Data System (ADS)

Wang, Zhanjun; Sohn, Il

2018-05-01

This review summarizes the significant results of high-temperature confocal laser scanning microscopy (CLSM) and single hot thermocouple technology (SHTT) and its application in observing the crystallization and growth in high-temperature oxide melts from iron- and steel-making slags to continuous casting mold fluxes. Using in situ observations of CLSM and SHTT images of high-temperature molten oxides with time, temperature, and composition, the crystallization behavior, including crystal morphology, crystallization temperature, initial nucleation and growth rate, could be obtained. The broad range of applications using in situ observations during crystallization have provided a wealth of opportunities in pyrometallurgy and is provided in this review.

Wearable Sweat Rate Sensors for Human Thermal Comfort Monitoring.

PubMed

Sim, Jai Kyoung; Yoon, Sunghyun; Cho, Young-Ho

2018-01-19

We propose watch-type sweat rate sensors capable of automatic natural ventilation by integrating miniaturized thermo-pneumatic actuators, and experimentally verify their performances and applicability. Previous sensors using natural ventilation require manual ventilation process or high-power bulky thermo-pneumatic actuators to lift sweat rate detection chambers above skin for continuous measurement. The proposed watch-type sweat rate sensors reduce operation power by minimizing expansion fluid volume to 0.4 ml through heat circuit modeling. The proposed sensors reduce operation power to 12.8% and weight to 47.6% compared to previous portable sensors, operating for 4 hours at 6 V batteries. Human experiment for thermal comfort monitoring is performed by using the proposed sensors having sensitivity of 0.039 (pF/s)/(g/m 2 h) and linearity of 97.9% in human sweat rate range. Average sweat rate difference for each thermal status measured in three subjects shows (32.06 ± 27.19) g/m 2 h in thermal statuses including 'comfortable', 'slightly warm', 'warm', and 'hot'. The proposed sensors thereby can discriminate and compare four stages of thermal status. Sweat rate measurement error of the proposed sensors is less than 10% under air velocity of 1.5 m/s corresponding to human walking speed. The proposed sensors are applicable for wearable and portable use, having potentials for daily thermal comfort monitoring applications.

Application of Statistical Methods of Rain Rate Estimation to Data From The TRMM Precipitation Radar

NASA Technical Reports Server (NTRS)

Meneghini, R.; Jones, J. A.; Iguchi, T.; Okamoto, K.; Liao, L.; Busalacchi, Antonio J. (Technical Monitor)

2000-01-01

The TRMM Precipitation Radar is well suited to statistical methods in that the measurements over any given region are sparsely sampled in time. Moreover, the instantaneous rain rate estimates are often of limited accuracy at high rain rates because of attenuation effects and at light rain rates because of receiver sensitivity. For the estimation of the time-averaged rain characteristics over an area both errors are relevant. By enlarging the space-time region over which the data are collected, the sampling error can be reduced. However. the bias and distortion of the estimated rain distribution generally will remain if estimates at the high and low rain rates are not corrected. In this paper we use the TRMM PR data to investigate the behavior of 2 statistical methods the purpose of which is to estimate the rain rate over large space-time domains. Examination of large-scale rain characteristics provides a useful starting point. The high correlation between the mean and standard deviation of rain rate implies that the conditional distribution of this quantity can be approximated by a one-parameter distribution. This property is used to explore the behavior of the area-time-integral (ATI) methods where fractional area above a threshold is related to the mean rain rate. In the usual application of the ATI method a correlation is established between these quantities. However, if a particular form of the rain rate distribution is assumed and if the ratio of the mean to standard deviation is known, then not only the mean but the full distribution can be extracted from a measurement of fractional area above a threshold. The second method is an extension of this idea where the distribution is estimated from data over a range of rain rates chosen in an intermediate range where the effects of attenuation and poor sensitivity can be neglected. The advantage of estimating the distribution itself rather than the mean value is that it yields the fraction of rain contributed by the light and heavy rain rates. This is useful in estimating the fraction of rainfall contributed by the rain rates that go undetected by the radar. The results at high rain rates provide a cross-check on the usual attenuation correction methods that are applied at the highest resolution of the instrument.

Regional distribution and losses of end-of-life steel throughout multiple product life cycles-Insights from the global multiregional MaTrace model.

PubMed

Pauliuk, Stefan; Kondo, Yasushi; Nakamura, Shinichiro; Nakajima, Kenichi

2017-01-01

Substantial amounts of post-consumer scrap are exported to other regions or lost during recovery and remelting, and both export and losses pose a constraint to desires for having regionally closed material cycles. To quantify the challenges and trade-offs associated with closed-loop metal recycling, we looked at the material cycles from the perspective of a single material unit and trace a unit of material through several product life cycles. Focusing on steel, we used current process parameters, loss rates, and trade patterns of the steel cycle to study how steel that was originally contained in high quality applications such as machinery or vehicles with stringent purity requirements gets subsequently distributed across different regions and product groups such as building and construction with less stringent purity requirements. We applied MaTrace Global, a supply-driven multiregional model of steel flows coupled to a dynamic stock model of steel use. We found that, depending on region and product group, up to 95% of the steel consumed today will leave the use phase of that region until 2100, and that up to 50% can get lost in obsolete stocks, landfills, or slag piles until 2100. The high losses resulting from business-as-usual scrap recovery and recycling can be reduced, both by diverting postconsumer scrap into long-lived applications such as buildings and by improving the recovery rates in the waste management and remelting industries. Because the lifetimes of high-quality (cold-rolled) steel applications are shorter and remelting occurs more often than for buildings and infrastructure, we found and quantified a tradeoff between low losses and high-quality applications in the steel cycle. Furthermore, we found that with current trade patterns, reduced overall losses will lead to higher fractions of secondary steel being exported to other regions. Current loss rates, product lifetimes, and trade patterns impede the closure of the steel cycle.

High-rate synthesis of phosphine-stabilized undecagold nanoclusters using a multilayered micromixer.

PubMed

Jin, Hyung Dae; Garrison, Anna; Tseng, T; Paul, Brian K; Chang, Chih-Hung

2010-11-05

Growth in the potential applications of nanomaterials has led to a focus on the development of new manufacturing approaches for these materials. In particular, an increased demand due to the unique properties of nanomaterials requires a substantial yield of high-performance materials and a simultaneous reduction in the environmental impact of these processes. In this paper, a high-rate production of phosphine-stabilized undecagold nanoclusters was achieved using a layer-up strategy which involves the use of microlamination architectures; the patterning and bonding of thin layers of material (laminae) to create a multilayered micromixer in the range of 25-250 µm thick was used to step up the production of phosphine-stabilized undecagold nanoclusters. The continuous production of highly monodispersed phosphine-stabilized undecagold nanoclusters at a rate of about 11.8 (mg s(-1)) was achieved using a microreactor with a size of 1.687 cm(3). This result is about 500 times over conventional batch syntheses based on the production rate per reactor volume.

High-rate synthesis of phosphine-stabilized undecagold nanoclusters using a multilayered micromixer

NASA Astrophysics Data System (ADS)

Jin, Hyung Dae; Garrison, Anna; Tseng, T.; Paul, Brian K.; Chang, Chih-Hung

2010-11-01

Growth in the potential applications of nanomaterials has led to a focus on the development of new manufacturing approaches for these materials. In particular, an increased demand due to the unique properties of nanomaterials requires a substantial yield of high-performance materials and a simultaneous reduction in the environmental impact of these processes. In this paper, a high-rate production of phosphine-stabilized undecagold nanoclusters was achieved using a layer-up strategy which involves the use of microlamination architectures; the patterning and bonding of thin layers of material (laminae) to create a multilayered micromixer in the range of 25-250 µm thick was used to step up the production of phosphine-stabilized undecagold nanoclusters. The continuous production of highly monodispersed phosphine-stabilized undecagold nanoclusters at a rate of about 11.8 (mg s - 1) was achieved using a microreactor with a size of 1.687 cm3. This result is about 500 times over conventional batch syntheses based on the production rate per reactor volume.

A single-walled carbon nanotubes/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)/copper hexacyanoferrate hybrid film for high-volumetric performance flexible supercapacitors

NASA Astrophysics Data System (ADS)

Li, Jianmin; Li, Haizeng; Li, Jiahui; Wu, Guiqing; Shao, Yuanlong; Li, Yaogang; Zhang, Qinghong; Wang, Hongzhi

2018-05-01

Volumetric energy density is generally considered to be detrimental to the actual application of supercapacitors, which has provoked a range of research work on increasing the packing density of electrodes. Herein, we fabricate a free-standing single-walled carbon nanotubes (SWCNTs)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/copper hexacyanoferrate (CuHCF) nanoparticles (NPs) composite supercapacitor electrode, with a high packing density of 2.67 g cm-3. The pseudocapacitive CuHCF NPs are decorated onto the SWCNTs/PEDOT:PSS networks and filled in interspace to increase both of packing density and specific capacitance. This hybrid electrode exhibits a series of outstanding performances, such as high electric conductivity, ultrahigh areal and volumetric capacitances (969.8 mF cm-2 and 775.2 F cm-3 at scan rate of 5 mV s-1), long cycle life and superior rate capability. The asymmetric supercapacitor built by using the SWCNTs/PEDOT:PSS/CuHCF film as positive electrode and Mo-doped WO3/SWCNTs film as negative electrode, can deliver a high energy density of 30.08 Wh L-1 with a power density of 4.25 kW L-1 based on the total volume of the device. The approach unveiled in this study could provide important insights to improving the volumetric performance of energy storage devices and help to reach the critical targets for high rate and high power density demand applications.

Misrepresentation of publications by radiology residency applicants: is it really a problem?

PubMed

Eisenberg, Ronald L; Cunningham, Meredith; Kung, Justin W; Slanetz, Priscilla J

2013-03-01

The aim of this study was to determine whether the previous relatively high rate of misrepresentation of publications is still a problem with current applicants for radiology residency. The publications submitted by a sample of 300 applicants for a radiology residency in 2011 were assessed using PubMed and an extensive Internet search to verify whether the articles were in print and had the applicants listed as authors and in the same positions of authorship. Whether the applicants graduated from US or international medical schools was recorded. Of the 138 applicants (46.0%) who cited 1 or more publications, there were 5 misrepresentations (3.6%). These included 1 article not found in the cited journal, 1 journal that could not be found, 1 article in which the applicant was not listed as an author, and 2 instances in which the applicants were not in the same positions of authorship (listed as lead authors but actually second authors). The misrepresentation rate was 1.9% among US graduates and 8.8% among graduates of international medical schools. The low rate of misrepresentation of publications, especially among graduates of US medical schools, does not seem to warrant spending the time to check the citations of journal articles of all applicants for radiology residency positions. Nevertheless, it is reasonable to request that applicants bring to their interviews a copy of each cited article and to assess their knowledge of all other listed research activities. Copyright © 2013 American College of Radiology. Published by Elsevier Inc. All rights reserved.

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

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

Wood, D.A.

1988-02-01

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

Parallel multigrid smoothing: polynomial versus Gauss-Seidel

NASA Astrophysics Data System (ADS)

Adams, Mark; Brezina, Marian; Hu, Jonathan; Tuminaro, Ray

2003-07-01

Gauss-Seidel is often the smoother of choice within multigrid applications. In the context of unstructured meshes, however, maintaining good parallel efficiency is difficult with multiplicative iterative methods such as Gauss-Seidel. This leads us to consider alternative smoothers. We discuss the computational advantages of polynomial smoothers within parallel multigrid algorithms for positive definite symmetric systems. Two particular polynomials are considered: Chebyshev and a multilevel specific polynomial. The advantages of polynomial smoothing over traditional smoothers such as Gauss-Seidel are illustrated on several applications: Poisson's equation, thin-body elasticity, and eddy current approximations to Maxwell's equations. While parallelizing the Gauss-Seidel method typically involves a compromise between a scalable convergence rate and maintaining high flop rates, polynomial smoothers achieve parallel scalable multigrid convergence rates without sacrificing flop rates. We show that, although parallel computers are the main motivation, polynomial smoothers are often surprisingly competitive with Gauss-Seidel smoothers on serial machines.

Neuron-Type-Specific Utility in a Brain-Machine Interface: a Pilot Study.

PubMed

Garcia-Garcia, Martha G; Bergquist, Austin J; Vargas-Perez, Hector; Nagai, Mary K; Zariffa, Jose; Marquez-Chin, Cesar; Popovic, Milos R

2017-11-01

Firing rates of single cortical neurons can be volitionally modulated through biofeedback (i.e. operant conditioning), and this information can be transformed to control external devices (i.e. brain-machine interfaces; BMIs). However, not all neurons respond to operant conditioning in BMI implementation. Establishing criteria that predict neuron utility will assist translation of BMI research to clinical applications. Single cortical neurons (n=7) were recorded extracellularly from primary motor cortex of a Long-Evans rat. Recordings were incorporated into a BMI involving up-regulation of firing rate to control the brightness of a light-emitting-diode and subsequent reward. Neurons were classified as 'fast-spiking', 'bursting' or 'regular-spiking' according to waveform-width and intrinsic firing patterns. Fast-spiking and bursting neurons were found to up-regulate firing rate by a factor of 2.43±1.16, demonstrating high utility, while regular-spiking neurons decreased firing rates on average by a factor of 0.73±0.23, demonstrating low utility. The ability to select neurons with high utility will be important to minimize training times and maximize information yield in future clinical BMI applications. The highly contrasting utility observed between fast-spiking and bursting neurons versus regular-spiking neurons allows for the hypothesis to be advanced that intrinsic electrophysiological properties may be useful criteria that predict neuron utility in BMI implementation.

Energy-signal quality trade-offs in a WiMAX mobile station with a booster amplifier

NASA Astrophysics Data System (ADS)

Suherman; Mubarakah, N.; Wiranata, O.; Kasim, S. T.

2018-02-01

Worldwide Interoperability for Microwave Access (WiMAX) is a broadband wireless access technology that is able to provide high bit rate mobile internet services. Battery endurance remains a problem in current mobile communication. On the other hand, signal quality determines the successful run of the mobile applications. Energy consumption optimization cannot sacrifice the signal level required by the application to run smoothly. On the contrary, the application should consider battery life time. This paper examines the tradeoffs between energy and signal quality in WiMAX subscriber station by adjusting signal level using a booster amplifier. Simulation evaluations show that an increment of 0.00000104% energy consumption on using amplifier adaptively produces 16.411% signal to noise ratio (SNR) increment and 10.7% bit error rate (BER) decrement. By keeping the amplifier turned on, energy consumption increases up to 0.00000136%, causing the SNR rises to 17.2638% and BER drops to 11.13%. The evaluated application is video streaming, other application may behave differently.

Applicability of self-activation of an NaI scintillator for measurement of photo-neutrons around a high-energy X-ray radiotherapy machine.

PubMed

Wakabayashi, Genichiro; Nohtomi, Akihiro; Yahiro, Eriko; Fujibuchi, Toshioh; Fukunaga, Junichi; Umezu, Yoshiyuki; Nakamura, Yasuhiko; Nakamura, Katsumasa; Hosono, Makoto; Itoh, Tetsuo

2015-01-01

The applicability of the activation of an NaI scintillator for neutron monitoring at a clinical linac was investigated experimentally. Thermal neutron fluence rates are derived by measurement of the I-128 activity generated in an NaI scintillator irradiated by neutrons; β-rays from I-128 are detected efficiently by the NaI scintillator. In order to verify the validity of this method for neutron measurement, we irradiated an NaI scintillator at a research reactor, and the neutron fluence rate was estimated. The method was then applied to neutron measurement at a 10-MV linac (Varian Clinac 21EX), and the neutron fluence rate was estimated at the isocenter and at 30 cm from the isocenter. When the scintillator was irradiated directly by high-energy X-rays, the production of I-126 was observed due to photo-nuclear reactions, in addition to the generation of I-128 and Na-24. From the results obtained by these measurements, it was found that the neutron measurement by activation of an NaI scintillator has a great advantage in estimates of a low neutron fluence rate by use of a quick measurement following a short-time irradiation. Also, the future application of this method to quasi real-time monitoring of neutrons during patient treatments at a radiotherapy facility is discussed, as well as the method of evaluation of the neutron dose.

[Rhizosphere effect of nutrients in different maize soils with different fertility levels].

PubMed

Wu, L; Zhang, S

2000-08-01

Maize plants and soil samples were collected from Jilin Province to study the nutrient dynamics in soil-maize plant rhizosphere and their relationship with plant uptake. The results showed that NH4(+)-N and NO3(-)-N were accumulated in rhizospheric soil, and mainly controlled by the application of chemical fertilizers. Soil available P was depleted in high fertility fields, especially in high seedling density, while accumulated in low fertility fields. Soil available K was accumulated in rhizospheric soil, and its accumulation rate was higher in high fertility than in low fertility fields. The nutrient absorption amount was N approximately K > P for maize plant shoots and roots, but was N > K > P for seeds. The contribution rate of chemical fertilizers to maize yield was only 1/5-1/3 in Jilin Province, and the rest was contributed by the application of organic manure, such as chicken feces or cow feces, and by the mineralization of soil organic matter.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses

NASA Astrophysics Data System (ADS)

Salehi, Fatholah; Goers, Andy; Hine, George; Feder, Linus; Kuk, Donghoon; Miao, Bo; Woodbury, Daniel; Kim, Ki-Yong; Milchberg, Howard

2017-01-01

We demonstrate laser driven acceleration of electrons to MeV-scale energies at 1 kHz repetition rate using <10 mJ pulses focused on near-critical density He and H2 gas jets. Using the H2 gas jet, electron acceleration to 0.5 MeV in 10 fC bunches was observed with laser pulse energy as low as 1.3 mJ. Increasing the pulse energy to 10 mJ, we measure 1pC charge bunches with >1 MeV energy for both He and H gas jets. Such a high repetition rate, high flux ultrafast source has immediate application to time resolved probing of matter for scientific, medical, or security applications, either using the electrons directly or using a high-Z foil converter to generate ultrafast γ-rays. This work is supported by the US Department of Energy, the National Science Foundation, and the Air Force Office of Scientific Research.

Design considerations of high-performance InGaAs/InP single-photon avalanche diodes for quantum key distribution.

PubMed

Ma, Jian; Bai, Bing; Wang, Liu-Jun; Tong, Cun-Zhu; Jin, Ge; Zhang, Jun; Pan, Jian-Wei

2016-09-20

InGaAs/InP single-photon avalanche diodes (SPADs) are widely used in practical applications requiring near-infrared photon counting such as quantum key distribution (QKD). Photon detection efficiency and dark count rate are the intrinsic parameters of InGaAs/InP SPADs, due to the fact that their performances cannot be improved using different quenching electronics given the same operation conditions. After modeling these parameters and developing a simulation platform for InGaAs/InP SPADs, we investigate the semiconductor structure design and optimization. The parameters of photon detection efficiency and dark count rate highly depend on the variables of absorption layer thickness, multiplication layer thickness, excess bias voltage, and temperature. By evaluating the decoy-state QKD performance, the variables for SPAD design and operation can be globally optimized. Such optimization from the perspective of specific applications can provide an effective approach to design high-performance InGaAs/InP SPADs.

Selection of Lecanicillium Strain with High Virulence against Developmental Stages of Bemisia tabaci

PubMed Central

Park, Heeyong

2010-01-01

Selection of fungal strains with high virulence against the developmental stages of Bemisia tabaci was performed using internal transcribed spacer regions. The growth rate of hyphae was measured and bioassay of each developmental stage of B. tabaci was conducted for seven days. All of the fungal strains tested were identified as Lecanicillium spp., with strain 4078 showing the fastest mycelium growth rate (colony diameter, 16.3 ± 0.9 mm) among the strains. Compared to strain 4075, which showed the slowest growth rate, the growth rate of strain 4078 was increased almost 2-fold after seven days. Strains 4078 and Btab01 were most virulent against the egg and larva stages, respectively. The virulence of fungal strains against the adult stage was high, except for strains 41185 and 3387. Based on the growth rate of mycelium and level of virulence, strains 4078 and Btab01 were selected as the best fungal strains for application to B. tabaci, regardless of developmental stage. PMID:23956657

RECTAL-SPECIFIC MICROBICIDE APPLICATOR: EVALUATION AND COMPARISON WITH A VAGINAL APPLICATOR USED RECTALLY

PubMed Central

Carballo-Diéguez, Alex; Giguere, Rebecca; Dolezal, Curtis; Bauermeister, José; Leu, Cheng-Shiun; Valladares, Juan; Rohan, Lisa C.; Anton, Peter A.; Cranston, Ross D.; Febo, Irma; Mayer, Kenneth; McGowan, Ian

2014-01-01

An applicator designed for rectal delivery of microbicides was tested for acceptability by 95 young men who have sex with men, who self-administered 4mL of placebo gel prior to receptive anal intercourse over 90 days. Subsequently, 24 of the participants self-administered rectally 4mL of tenofovir or placebo gel over 7 days using a vaginal applicator, and compared both applicators on a Likert scale of 1–10, with 10 the highest rating. Participants reported high likelihood to use either applicator in the future (mean scores 9.3 and 8.8 respectively, p= ns). Those who tested both liked the vaginal applicator significantly more than the rectal applicator (7.8 vs. 5.2, p=0.003). Improvements in portability, conspicuousness, aesthetics, tip comfort, product assembly and packaging were suggested for both. This rectal-specific applicator was not superior to a vaginal applicator. While likelihood of future use is reportedly high, factors that decrease acceptability may erode product use over time in clinical trials. Further attention is needed to develop user-friendly, quick-acting rectal microbicide delivery systems. PMID:24858481

High shear microfluidics and its application in rheological measurement

NASA Astrophysics Data System (ADS)

Kang, Kai; Lee, L. James; Koelling, Kurt W.

2005-02-01

High shear rheology was explored experimentally in microchannels (150×150 μm). Two aqueous polymer solutions, polyethylene oxide (viscoelastic fluid) and hydroxyethyl cellulose (viscous fluid) were tested. Bagley correction was applied to remove the end effect. Wall slip was investigated with Mooney’s analysis. Shear rates as high as 106 s-1 were obtained in the pressure-driven microchannel flow, allowing a smooth extension of the low shear rheological data obtained from the conventional rheometers. At high shear rates, polymer degradation was observed for PEO solutions at a critical microchannel wall shear stress of 4.1×103 Pa. Stresses at the ends of the microchannel also contributed to PEO degradation significantly.

Large motion high cycle high speed optical fibers for space based applications.

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

Stromberg, Peter G.; Tandon, Rajan; Gibson, Cory S.

2014-10-01

Future remote sensing applications will require higher resolution and therefore higher data rates (up to perhaps 100 gigabits per second) while achieving lower mass and cost. A current limitation to the design space is high speed high bandwidth data does not cross movable gimbals because of cabling issues. This requires the detectors to be off gimbal. The ability to get data across the gimbal would open up efficiencies in designs where the detectors and the electronics can be placed anywhere on the system. Fiber optic cables provide light weight high speed high bandwidth connections. Current options are limited to 20,000more » cycles as opposed to the 1,000,000 cycles needed for future space based applications. To extend this to the million+ regime, requires a thorough understanding of the failure mechanisms and the materials, proper selection of materials (e.g., glass and jacket material) allowable geometry changes to the cable, radiation hardness, etc.« less

High-Speed, high-power, switching transistor

NASA Technical Reports Server (NTRS)

Carnahan, D.; Ohu, C. K.; Hower, P. L.

1979-01-01

Silicon transistor rate for 200 angstroms at 400 to 600 volts combines switching speed of transistors with ruggedness, power capacity of thyristor. Transistor introduces unique combination of increased power-handling capability, unusally low saturation and switching losses, and submicrosecond switching speeds. Potential applications include high power switching regulators, linear amplifiers, chopper controls for high frequency electrical vehicle drives, VLF transmitters, RF induction heaters, kitchen cooking ranges, and electronic scalpels for medical surgery.

Polyaniline-based memristive microdevice with high switching rate and endurance

NASA Astrophysics Data System (ADS)

Lapkin, D. A.; Emelyanov, A. V.; Demin, V. A.; Erokhin, V. V.; Feigin, L. A.; Kashkarov, P. K.; Kovalchuk, M. V.

2018-01-01

Polyaniline (PANI) based memristive devices have emerged as promising candidates for hardware implementation of artificial synapses (the key components of neuromorphic systems) due to their high flexibility, low cost, solution processability, three-dimensional stacking capability, and biocompatibility. Here, we report on a way of the significant improvement of the switching rate and endurance of PANI-based memristive devices. The reduction of the PANI active channel dimension leads to the increase in the resistive switching rate by hundreds of times in comparison with the conventional one. The miniaturized memristive device was shown to be stable within at least 104 cyclic switching events between high- and low-conductive states with a retention time of at least 103 s. The obtained results make PANI-based memristive devices potentially widely applicable in neuromorphic systems.

Video on phone lines: technology and applications

NASA Astrophysics Data System (ADS)

Hsing, T. Russell

1996-03-01

Recent advances in communications signal processing and VLSI technology are fostering tremendous interest in transmitting high-speed digital data over ordinary telephone lines at bit rates substantially above the ISDN Basic Access rate (144 Kbit/s). Two new technologies, high-bit-rate digital subscriber lines and asymmetric digital subscriber lines promise transmission over most of the embedded loop plant at 1.544 Mbit/s and beyond. Stimulated by these research promises and rapid advances on video coding techniques and the standards activity, information networks around the globe are now exploring possible business opportunities of offering quality video services (such as distant learning, telemedicine, and telecommuting etc.) through this high-speed digital transport capability in the copper loop plant. Visual communications for residential customers have become more feasible than ever both technically and economically.

Tele-Assessment of the Berg Balance Scale: Effects of Transmission Characteristics.

PubMed

Venkataraman, Kavita; Morgan, Michelle; Amis, Kristopher A; Landerman, Lawrence R; Koh, Gerald C; Caves, Kevin; Hoenig, Helen

2017-04-01

To compare Berg Balance Scale (BBS) rating using videos with differing transmission characteristics with direct in-person rating. Repeated-measures study for the assessment of the BBS in 8 configurations: in person, high-definition video with slow motion review, standard-definition videos with varying bandwidths and frame rates (768 kilobytes per second [kbps] videos at 8, 15, and 30 frames per second [fps], 30 fps videos at 128, 384, and 768 kbps). Medical center. Patients with limitations (N=45) in ≥1 of 3 specific aspects of motor function: fine motor coordination, gross motor coordination, and gait and balance. Not applicable. Ability to rate the BBS in person and using videos with differing bandwidths and frame rates in frontal and lateral views. Compared with in-person rating (7%), 18% (P=.29) of high-definition videos and 37% (P=.03) of standard-definition videos could not be rated. Interrater reliability for the high-definition videos was .96 (95% confidence interval, .94-.97). Rating failure proportions increased from 20% in videos with the highest bandwidth to 60% (P<.001) in videos with the lowest bandwidth, with no significant differences in proportions across frame rate categories. Both frontal and lateral views were critical for successful rating using videos, with 60% to 70% (P<.001) of videos unable to be rated on a single view. Although there is some loss of information when using videos to rate the BBS compared to in-person ratings, it is feasible to reliably rate the BBS remotely in standard clinical spaces. However, optimal video rating requires frontal and lateral views for each assessment, high-definition video with high bandwidth, and the ability to carry out slow motion review. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Deposition of insecticides on corn silks applied at high and low spray rates for control of corn earworm

USDA-ARS?s Scientific Manuscript database

Corn earworm is a major pest of sweet corn, especially when grown organically. Aerial application of insecticides is important for both conventionally- and organically-grown sweet corn production as sweet corn is frequently irrigated to assure return on investment given the high production costs. ...

Waiving Away High School Graduation Rate Accountability? Policy Brief

ERIC Educational Resources Information Center

Alliance for Excellent Education, 2012

2012-01-01

In November 2011, eleven states submitted applications to the U.S. Department of Education (ED) for waivers from key provisions of the No Child Left Behind Act. Although the waiver process presents an opportunity to strengthen college and career readiness among the nation's high school students, this analysis by the Alliance for Excellent…

Thermoresponsive release of viable microfiltrated Circulating Tumor Cells (CTCs) for precision medicine applications

PubMed Central

Ao, Zheng; Parasido, Erika; Rawal, Siddarth; Williams, Anthony; Schlegel, Richard; Liu, Stephen; Albanese, Chris; Cote, Richard J.; Agarwal, Ashutosh; Datar, Ram H.

2015-01-01

Stimulus responsive release of Circulating Tumor Cells (CTCs), with high recovery rates from their capture platform, is highly desirable for off-chip analyses. Here, we present a temperature responsive polymer coating method to achieve both release as well as culture of viable CTCs captured from patient blood samples. PMID:26426331

Application of an in vivo hepatic triacylglycerol production method in the setting of a high fat diet in mice

USDA-ARS?s Scientific Manuscript database

High fat (HF) diets typically promote diet-induced obesity (DIO) and metabolic dysfunction (i.e., insulin resistance, hypertriglyceridemia, and hepatic steatosis). Changes in TAG metabolism contribute to the development of hepatic steatosis including changes in production rate from de novo lipogenes...

Learning from Math Circles: Providing Underserved Students of Color with Accessibility to Mathematics Education

ERIC Educational Resources Information Center

Winful, Audrey M.

2009-01-01

Consistently high minority failure rates in high school and college mathematics, the noticeable decrease in access to mathematics education for our underserved students of color, and this mathematics educator's genuine belief in the global necessity, desirability, and applicability of engaging our youth in learning mathematics through Math…

Rechargeable Lithium-Ion Based Batteries and Thermal Management for Airborne High Energy Electric Lasers (Preprint)

DTIC Science & Technology

2006-08-01

applications have been substantial. Rechargeable high rate lithium - ion batteries are now exceeding 6 kW/kg for short discharge times 15 seconds...rechargeable lithium - ion batteries as a function of onboard power, electric laser power level, laser duty cycle, and total mission time is presented. A number

High-Speed Videography Instrumentation And Procedures

NASA Astrophysics Data System (ADS)

Miller, C. E.

1982-02-01

High-speed videography has been an electronic analog of low-speed film cameras, but having the advantages of instant-replay and simplicity of operation. Recent advances have pushed frame-rates into the realm of the rotating prism camera. Some characteristics of videography systems are discussed in conjunction with applications in sports analysis, and with sports equipment testing.

Fertilizer N application rate impacts plant-soil feedback in a sanqi production system.

PubMed

Wei, Wei; Yang, Min; Liu, Yixiang; Huang, Huichuan; Ye, Chen; Zheng, Jianfen; Guo, Cunwu; Hao, Minwen; He, Xiahong; Zhu, Shusheng

2018-08-15

Replant failure caused by negative plant-soil feedback (NPFS) in agricultural ecosystems is a critical factor restricting the development of sustainable agriculture. Soil nutrient availability has the capacity to affect plant-soil feedback. Here, we used sanqi (Panax notoginseng), which is severely threatened by NPSF, as a model plant to decipher the overall effects of nitrogen (N) rates on NPSF and the underlying mechanism. We found that a high rate of N at 450kgNha -1 (450N) aggravated the NPSF through the accumulation of pathogens in the soil compared with the optimal 250N. The increased N rates resulted in a significant increase in the soil electrical conductivity and available nitrogen but a decrease in the soil pH and C/N ratio. GeoChip 5.0 data demonstrated that these changed soil properties caused the soil to undergo stress (acidification, salinization and carbon starvation), as indicated by the enriched soil microbial gene abundances related to stress response and nutrition cycling (N, C and S). Accordingly, increased N rates reduced the richness and diversity of soil fungi and bacteria and eventually caused a shift in soil microbes from a bacterial-dominant community to a fungal-dominant community. In particular, the high 450N treatment significantly suppressed the abundance of copiotrophic bacteria, including beneficial genera Bacillus and Pseudomonas, thus weakening the antagonistic activity of these bacteria against fungal pathogens. Moreover, 450N application significantly enriched the abundance of pathogen pathogenicity-related genes. Once sanqi plants were grown in this N-stressed soil, their host-specific fungal pathogen Fusarium oxysporum significantly accumulated, which aggravated the process of NPSF. This study suggested that over-application of nitrogen is not beneficial for disease management or the reduction of fungicide application in agricultural production. Copyright © 2018 Elsevier B.V. All rights reserved.

A Real-Time High Performance Data Compression Technique For Space Applications

NASA Technical Reports Server (NTRS)

Yeh, Pen-Shu; Venbrux, Jack; Bhatia, Prakash; Miller, Warner H.

2000-01-01

A high performance lossy data compression technique is currently being developed for space science applications under the requirement of high-speed push-broom scanning. The technique is also error-resilient in that error propagation is contained within a few scan lines. The algorithm is based on block-transform combined with bit-plane encoding; this combination results in an embedded bit string with exactly the desirable compression rate. The lossy coder is described. The compression scheme performs well on a suite of test images typical of images from spacecraft instruments. Hardware implementations are in development; a functional chip set is expected by the end of 2001.

Improved Performance of Ionic Liquid Supercapacitors by using Tetracyanoborate Anions

PubMed Central

Martins, Vitor L.; Rennie, Anthony J. R.; Sanchez‐Ramirez, Nedher; Torresi, Roberto M.; Hall, Peter J.

2018-01-01

Abstract Supercapacitors are energy storage devices designed to operate at higher power densities than conventional batteries, but their energy density is still too low for many applications. Efforts are made to design new electrolytes with wider electrochemical windows than aqueous or conventional organic electrolytes in order to increase energy density. Ionic liquids (ILs) with wide electrochemical stability windows are excellent candidates to be employed as supercapacitor electrolytes. ILs containing tetracyanoborate anions [B(CN)4] offer wider electrochemical stability than conventional electrolytes and maintain a high ionic conductivity (6.9 mS cm−1). Herein, we report the use of ILs containing the [B(CN)4] anion for such an application. They presented a high maximum operating voltage of 3.7 V, and two‐electrode devices demonstrate high specific capacitances even when operating at relatively high rates (ca. 20 F g−1 @ 15 A g−1). This supercapacitor stored more energy and operated at a higher power at all rates studied when compared with cells using a commonly studied ILs. PMID:29577008

Advantages offered by high average power picosecond lasers

NASA Astrophysics Data System (ADS)

Moorhouse, C.

2011-03-01

As electronic devices shrink in size to reduce material costs, device size and weight, thinner material thicknesses are also utilized. Feature sizes are also decreasing, which is pushing manufacturers towards single step laser direct write process as an attractive alternative to conventional, multiple step photolithography processes by eliminating process steps and the cost of chemicals. The fragile nature of these thin materials makes them difficult to machine either mechanically or with conventional nanosecond pulsewidth, Diode Pumped Solids State (DPSS) lasers. Picosecond laser pulses can cut materials with reduced damage regions and selectively remove thin films due to the reduced thermal effects of the shorter pulsewidth. Also, the high repetition rate allows high speed processing for industrial applications. Selective removal of thin films for OLED patterning, silicon solar cells and flat panel displays is discussed, as well as laser cutting of transparent materials with low melting point such as Polyethylene Terephthalate (PET). For many of these thin film applications, where low pulse energy and high repetition rate are required, throughput can be increased by the use of a novel technique to using multiple beams from a single laser source is outlined.

Insulator photocurrents: Application to dose rate hardening of CMOS/SOI integrated circuits

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

Dupont-Nivet, E.; Coiec, Y.M.; Flament, O.

1998-06-01

Irradiation of insulators with a pulse of high energy x-rays can induce photocurrents in the interconnections of integrated circuits. The authors present, here, a new method to measure and analyze this effect together with a simple model. They also demonstrate that these insulator photocurrents have to be taken into account to obtain high levels of dose-rate hardness with CMOS on SOI integrated circuits, especially flip-flops or memory blocks of ASICs. They show that it explains some of the upsets observed in a SRAM embedded in an ASIC.

A model of high-rate indentation of a cylindrical striking pin into a deformable body

NASA Astrophysics Data System (ADS)

Zalazinskaya, E. A.; Zalazinsky, A. G.

2017-12-01

Mathematical modeling of an impact and high-rate indentation to a significant depth of a flat-faced hard cylindrical striking pin into a massive deformable target body is carried out. With the application of the kinematic extreme theorem of the plasticity theory and the kinetic energy variation theorem, the phase trajectories of the striking pin are calculated, the initial velocity of the striking pin in the body, the limit values of the inlet duct length, and the depth of striking pin penetration into the target are determined.

NOVEL HERBICIDES

EPA Science Inventory

Low-dose, high-potency herbicides are defined as those herbicides with a maximum label application rate of 0.5 pounds of active ingredient per acre. Several classes of chemicals fall into this category, including the acetolactate synthase (ALSase) inhibitor herbicides, imidazoli...

Magnesium for Crashworthy Components

NASA Astrophysics Data System (ADS)

Abbott, T.; Easton, M.; Schmidt, R.

Most applications of magnesium in automobiles are for nonstructural components. However, the light weight properties of magnesium make it attractive in structural applications where energy absorption in a crash is critical. Because most deformation in a crash occurs as bending rather than simple tension or compression, the advantages of magnesium are greater than anticipated simply from tensile strength to weight ratios. The increased thickness possible with magnesium strongly influences bending behavior and theoretical calculations suggest almost an order of magnitude greater energy absorption with magnesium compared to the same weight of steel. The strain rate sensitivity of steel is of concern for energy absorption. Mild steels exhibit a distinct yield point which increases with strain rate. At strain rates typical of vehicle impact, this can result in strain localization and poor energy absorption. Magnesium alloys with relatively low aluminum contents exhibit strain rate sensitivity, however, this is manifest as an increase in work hardening and tensile / yield ratio. This behavior suggests that the performance of magnesium alloys in terms of energy absorption actually improves at high strain rates.

Fe-Catalyzed Synthesis of Porous Carbons Spheres with High Graphitization Degree for High-Performance Supercapacitors

NASA Astrophysics Data System (ADS)

Zhu, Jun; Shi, Hongwei; Zhuo, Xin; Hu, Yalin

2017-10-01

We have developed a facile and efficient Fe-catalyzed method for fabrication of porous carbons spheres with high graphitization degree (GNPCs) using glucose as carbon precursor at relatively low carbonization temperature. GNPCs not only have relatively large accessible ion surface area to accommodate greater capacity but also high graphitization degree to accelerate ion diffusion. As a typical application, we demonstrate that GNPCs exhibit excellent electrochemical performance for use in supercapacitors, with high specific capacity of 150.6 F g-1 at current density of 1 A g-1 and good rate capability and superior cycling stability over 10,000 cycles, confirming their potential application for energy storage. Moreover, it is believed that this method offers a new strategy for synthesis of porous carbons with high graphitization degree.

Development of a Web GIS Application for Visualizing and Analyzing Community Out of Hospital Cardiac Arrest Patterns

PubMed Central

Semple, Hugh; Qin, Han; Sasson, Comilla

2013-01-01

Improving survival rates at the neighborhood level is increasingly seen as a priority for reducing overall rates of out-of-hospital cardiac arrest (OHCA) in the United States. Since wide disparities exist in OHCA rates at the neighborhood level, it is important for public health officials and residents to be able to quickly locate neighborhoods where people are at elevated risk for cardiac arrest and to target these areas for educational outreach and other mitigation strategies. This paper describes an OHCA web mapping application that was developed to provide users with interactive maps and data for them to quickly visualize and analyze the geographic pattern of cardiac arrest rates, bystander CPR rates, and survival rates at the neighborhood level in different U.S. cities. The data comes from the CARES Registry and is provided over a period spanning several years so users can visualize trends in neighborhood out-of-hospital cardiac arrest patterns. Users can also visualize areas that are statistical hot and cold spots for cardiac arrest and compare OHCA and bystander CPR rates in the hot and cold spots. Although not designed as a public participation GIS (PPGIS), this application seeks to provide a forum around which data and maps about local patterns of OHCA can be shared, analyzed and discussed with a view of empowering local communities to take action to address the high rates of OHCA in their vicinity. PMID:23923097

ELI-Beamlines: development of next generation short-pulse laser systems

NASA Astrophysics Data System (ADS)

Rus, B.; Bakule, P.; Kramer, D.; Naylon, J.; Thoma, J.; Green, J. T.; Antipenkov, R.; Fibrich, M.; Novák, J.; Batysta, F.; Mazanec, T.; Drouin, M. A.; Kasl, K.; Baše, R.; Peceli, D.; Koubíková, L.; Trojek, P.; Boge, R.; Lagron, J. C.; Vyhlídka, Å.; Weiss, J.; Cupal, J.,; Hřebíček, J.; Hříbek, P.; Durák, M.; Polan, J.; Košelja, M.; Korn, G.; Horáček, M.; Horáček, J.; Himmel, B.; Havlíček, T.; Honsa, A.; Korouš, P.; Laub, M.; Haefner, C.; Bayramian, A.; Spinka, T.; Marshall, C.; Johnson, G.; Telford, S.; Horner, J.; Deri, B.; Metzger, T.; Schultze, M.; Mason, P.; Ertel, K.; Lintern, A.; Greenhalgh, J.; Edwards, C.; Hernandez-Gomez, C.; Collier, J.; Ditmire, T.,; Gaul, E.; Martinez, M.; Frederickson, C.; Hammond, D.; Malato, C.; White, W.; Houžvička, J.

2015-05-01

Overview of the laser systems being built for ELI-Beamlines is presented. The facility will make available high-brightness multi-TW ultrashort laser pulses at kHz repetition rate, PW 10 Hz repetition rate pulses, and kilojoule nanosecond pulses for generation of 10 PW peak power. The lasers will extensively employ the emerging technology of diode-pumped solid-state lasers (DPSSL) to pump OPCPA and Ti:sapphire broadband amplifiers. These systems will provide the user community with cutting-edge laser resources for programmatic research in generation and applications of high-intensity X-ray sources, in particle acceleration, and in dense-plasma and high-field physics.

[Trends of microalgal biotechnology: a view from bibliometrics].

PubMed

Yang, Xiaoqiu; Wu, Yinsong; Yan, Jinding; Song, Haigang; Fan, Jianhua; Li, Yuanguang

2015-10-01

Microalgae is a single-cell organism with the characteristics of high light energy utilization rate, fast growth rate, high-value bioactive components and high energy material content. Therefore, microalgae has broad application prospects in food, feed, bioenergy, carbon sequestration, wastewater treatment and other fields. In this article, the microalgae biotechnology development in recent years were fully consulted, through analysis from the literature and patent. The progress of microalgal biotechnology at home and abroad is compared and discussed. Furthermore, the project layout, important achievements and development bottlenecks of microalgae biotechnology in our country were also summarized. At last, future development directions of microalgae biotechnology were discussed.

A study of high density bit transition requirements versus the effects on BCH error correcting coding

NASA Technical Reports Server (NTRS)

Ingels, F.; Schoggen, W. O.

1981-01-01

Several methods for increasing bit transition densities in a data stream are summarized, discussed in detail, and compared against constraints imposed by the 2 MHz data link of the space shuttle high rate multiplexer unit. These methods include use of alternate pulse code modulation waveforms, data stream modification by insertion, alternate bit inversion, differential encoding, error encoding, and use of bit scramblers. The psuedo-random cover sequence generator was chosen for application to the 2 MHz data link of the space shuttle high rate multiplexer unit. This method is fully analyzed and a design implementation proposed.

Aircraft and satellite thermographic systems for wildfire mapping and assessment

NASA Technical Reports Server (NTRS)

Brass, J. A.; Arvesen, J. C.; Ambrosia, V. G.; Riggan, P. J.; Myers, J. S.

1987-01-01

Two complementary sensors, the DAEDALUS DEI-1260 Multispectral Scanner aboard the NASA U-2 aircraft and the Advanced Very High Resolution Radiometer aboard National Oceanographic and Atmospheric Administration orbiting satellites were tested for their applicability in monitoring and predicting parameters such as fire location, temperature and rate of spread, soil heating and cooling rates, and plume characteristics and dimensions. In addition, the satellite system was tested for its ability to extend the relationships found between fire characteristics and biospheric consequences to regional and global scales. An overall system design is presented, and special requirements are documented for the application of this system for fire research and management.

Bladder–Rectum Spacer Balloon in High-Dose-Rate Brachytherapy in Cervix Carcinoma

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

Rai, Bhavana; Patel, Firuza D., E-mail: firuzapatel@gmail.com; Chakraborty, Santam

2013-04-01

Purpose: To compare bladder and rectum doses with the use of a bladder–rectum spacer balloon (BRSB) versus standard gauze packing in the same patient receiving 2 high-dose-rate intracavitary brachytherapy fractions. Methods and Materials: This was a randomized study to compare the reduction in bladder and rectum doses with the use of a BRSB compared with standard gauze packing in patients with carcinoma of the cervix being treated with high-dose-rate intracavitary brachytherapy. The patients were randomized between 2 arms. In arm A, vaginal packing was done with standard gauze packing in the first application, and BRSB was used in the secondmore » application. Arm B was the reverse of arm A. The International Commission for Radiation Units and Measurement (ICRU) point doses and doses to 0.1-cm{sup 3}, 1-cm{sup 3}, 2-cm{sup 3}, 5-cm{sup 3}, and 10-cm{sup 3} volumes of bladder and rectum were compared. The patients were also subjectively assessed for the ease of application and the time taken for application. Statistical analysis was done using the paired t test. Results: A total of 43 patients were enrolled; however, 3 patients had to be excluded because the BRSB could not be inserted owing to unfavorable local anatomy. Thus 40 patients (80 plans) were evaluated. The application was difficult in 3 patients with BRSB, and in 2 patients with BRSB the application time was prolonged. There was no significant difference in bladder doses to 0.1 cm{sup 3}, 1 cm{sup 3}, 2 cm{sup 3}, 5 cm{sup 3}, and 10 cm{sup 3} and ICRU bladder point. Statistically significant dose reductions to 0.1-cm{sup 3}, 1-cm{sup 3}, and 2-cm{sup 3} volumes for rectum were observed with the BRSB. No significant differences in 5-cm{sup 3} and 10-cm{sup 3} volumes and ICRU rectum point were observed. Conclusion: A statistically significant dose reduction was observed for small high-dose volumes in rectum with the BRSB. The doses to bladder were comparable for BRSB and gauze packing. Transparent balloons of variable sizes are recommended for patients with a less spacious vaginal cavity.« less

Multiple Sensor Camera for Enhanced Video Capturing

NASA Astrophysics Data System (ADS)

Nagahara, Hajime; Kanki, Yoshinori; Iwai, Yoshio; Yachida, Masahiko

A resolution of camera has been drastically improved under a current request for high-quality digital images. For example, digital still camera has several mega pixels. Although a video camera has the higher frame-rate, the resolution of a video camera is lower than that of still camera. Thus, the high-resolution is incompatible with the high frame rate of ordinary cameras in market. It is difficult to solve this problem by a single sensor, since it comes from physical limitation of the pixel transfer rate. In this paper, we propose a multi-sensor camera for capturing a resolution and frame-rate enhanced video. Common multi-CCDs camera, such as 3CCD color camera, has same CCD for capturing different spectral information. Our approach is to use different spatio-temporal resolution sensors in a single camera cabinet for capturing higher resolution and frame-rate information separately. We build a prototype camera which can capture high-resolution (2588×1958 pixels, 3.75 fps) and high frame-rate (500×500, 90 fps) videos. We also proposed the calibration method for the camera. As one of the application of the camera, we demonstrate an enhanced video (2128×1952 pixels, 90 fps) generated from the captured videos for showing the utility of the camera.

3-dimensional interconnected framework of N-doped porous carbon based on sugarcane bagasse for application in supercapacitors and lithium ion batteries

NASA Astrophysics Data System (ADS)

Wang, Bin; Wang, Yunhui; Peng, Yueying; Wang, Xin; Wang, Jing; Zhao, Jinbao

2018-06-01

In this work, N-doped biomass derived porous carbon (NSBDC) has been prepared utilizing low-cost agricultural waste-sugarcane bagasse as the prototype, and needle-like PANI as the dopant. NSBDC possesses a special 3D interconnected framework structure, superior hierarchical pores and suitable heteroatom doping level, which benefits a large number of applications on ion storage and high-rate ion transfer. Typically, the NSBDC exhibits the high specific capacitance (298 F g-1 at 1 A g-1) and rate capability (58.7% capacitance retention at 20 A g-1), as well as the high cycle stability (5.5% loss over 5000 cycles) in three-electrode systems. A two-electrode asymmetric system has been fabricated employing NSBDC and the precursor of NSBDC (sugarcane bagasse derived carbon/PANI composite) as the negative and positive electrodes, respectively, and an energy density as high as 49.4 Wh kg-1 is verified in this asymmetric system. A NSBDC-based whole symmetric supercapacitors has also been assembled, and it can easily light a 1.5 V bulb due to its high energy density (27.7 Wh kg-1). In addition, for expanding the application areas of NSBDC, it is also applied to lithium ion battery, and a high reversible capacity of 1148 mAh g-1 at 0.1 A g-1 is confirmed. Even at 5 A g-1, NSBDC can still deliver a high reversible capacity of 357 mAh g-1 after 200 cycles, indicating its superior lithium storage capability.

Nonadiabatic rate constants for proton transfer and proton-coupled electron transfer reactions in solution: Effects of quadratic term in the vibronic coupling expansion

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

Soudackov, Alexander; Hammes-Schiffer, Sharon

2015-11-17

Rate constant expressions for vibronically nonadiabatic proton transfer and proton-coupled electron transfer reactions are presented and analyzed. The regimes covered include electronically adiabatic and nonadiabatic reactions, as well as high-frequency and low-frequency regimes for the proton donor-acceptor vibrational mode. These rate constants differ from previous rate constants derived with the cumulant expansion approach in that the logarithmic expansion of the vibronic coupling in terms of the proton donor-acceptor distance includes a quadratic as well as a linear term. The analysis illustrates that inclusion of this quadratic term does not significantly impact the rate constants derived using the cumulant expansion approachmore » in any of the regimes studied. The effects of the quadratic term may become significant when using the vibronic coupling expansion in conjunction with a thermal averaging procedure for calculating the rate constant, however, particularly at high temperatures and for proton transfer interfaces with extremely soft proton donor-acceptor modes that are associated with extraordinarily weak hydrogen bonds. Even with the thermal averaging procedure, the effects of the quadratic term for weak hydrogen-bonding systems are less significant for more physically realistic models that prevent the sampling of unphysical short proton donor-acceptor distances, and the expansion of the coupling can be avoided entirely by calculating the couplings explicitly for the range of proton donor-acceptor distances. This analysis identifies the regimes in which each rate constant expression is valid and thus will be important for future applications to proton transfer and proton-coupled electron transfer in chemical and biological processes. We are grateful for support from National Institutes of Health Grant GM056207 (applications to enzymes) and the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (applications to molecular electrocatalysts).« less

A data acquisition and control system for high-speed gamma-ray tomography

NASA Astrophysics Data System (ADS)

Hjertaker, B. T.; Maad, R.; Schuster, E.; Almås, O. A.; Johansen, G. A.

2008-09-01

A data acquisition and control system (DACS) for high-speed gamma-ray tomography based on the USB (Universal Serial Bus) and Ethernet communication protocols has been designed and implemented. The high-speed gamma-ray tomograph comprises five 500 mCi 241Am gamma-ray sources, each at a principal energy of 59.5 keV, which corresponds to five detector modules, each consisting of 17 CdZnTe detectors. The DACS design is based on Microchip's PIC18F4550 and PIC18F4620 microcontrollers, which facilitates an USB 2.0 interface protocol and an Ethernet (IEEE 802.3) interface protocol, respectively. By implementing the USB- and Ethernet-based DACS, a sufficiently high data acquisition rate is obtained and no dedicated hardware installation is required for the data acquisition computer, assuming that it is already equipped with a standard USB and/or Ethernet port. The API (Application Programming Interface) for the DACS is founded on the National Instrument's LabVIEW® graphical development tool, which provides a simple and robust foundation for further application software developments for the tomograph. The data acquisition interval, i.e. the integration time, of the high-speed gamma-ray tomograph is user selectable and is a function of the statistical measurement accuracy required for the specific application. The bandwidth of the DACS is 85 kBytes s-1 for the USB communication protocol and 28 kBytes s-1 for the Ethernet protocol. When using the iterative least square technique reconstruction algorithm with a 1 ms integration time, the USB-based DACS provides an online image update rate of 38 Hz, i.e. 38 frames per second, whereas 31 Hz for the Ethernet-based DACS. The off-line image update rate (storage to disk) for the USB-based DACS is 278 Hz using a 1 ms integration time. Initial characterization of the high-speed gamma-ray tomograph using the DACS on polypropylene phantoms is presented in the paper.

Factors controlling nitrate fluxes in groundwater in agricultural areas

USGS Publications Warehouse

Liao, Lixia; Green, Christopher T.; Bekins, Barbara A.; Böhlke, J.K.

2012-01-01

The impact of agricultural chemicals on groundwater quality depends on the interactions of biogeochemical and hydrologic factors. To identify key processes affecting distribution of agricultural nitrate in groundwater, a parsimonious transport model was applied at 14 sites across the U.S. Simulated vertical profiles of NO3-, N2 from denitrification, O2, Cl-, and environmental tracers of groundwater age were matched to observations by adjusting the parameters for recharge rate, unsaturated zone travel time, fractions of N and Cl- inputs leached to groundwater, O2 reduction rate, O2 threshold for denitrification, and denitrification rate. Model results revealed important interactions among biogeochemical and physical factors. Chloride fluxes decreased between the land surface and water table possibly because of Cl- exports in harvested crops (averaging 22% of land-surface Cl- inputs). Modeled zero-order rates of O2 reduction and denitrification were correlated. Denitrification rates at depth commonly exceeded overlying O2 reduction rates, likely because shallow geologic sources of reactive electron donors had been depleted. Projections indicated continued downward migration of NO3- fronts at sites with denitrification rates -1 yr-1. The steady state depth of NO3- depended to a similar degree on application rate, leaching fraction, recharge, and NO3- and O2 reaction rates. Steady state total mass in each aquifer depended primarily on the N application rate. In addition to managing application rates at land surface, efficient water use may reduce the depth and mass of N in groundwater because lower recharge was associated with lower N fraction leached. Management actions to reduce N leaching could be targeted over aquifers with high-recharge and low-denitrification rates.

The Use of the Interactive Whiteboard in Mathematics and Mathematics Lessons from the Perspective of Turkish Middle School Students

ERIC Educational Resources Information Center

Önal, Nezih; Demir, Cennet Göloglu

2017-01-01

It is a great paradox that despite the great importance attached to mathematics education in Turkey, high failure rates are observed among Turkish students in mathematics. For this reason, new applications are implemented in the field of mathematics education in Turkey. One of these applications is the use of technology in mathematics education.…

The dynamic Virtual Fields Method on rubbers at medium and high strain rates

NASA Astrophysics Data System (ADS)

Yoon, Sung-Ho; Siviour, Clive R.

2015-09-01

Elastomeric materials are widely used for energy absorption applications, often experiencing high strain rate deformations. The mechanical characterization of rubbers at high strain rates presents several experimental difficulties, especially associated with achieving adequate signal to noise ratio and static stress equilibrium, when using a conventional technique such as the split Hopkinson pressure bar. In the present study, these problems are avoided by using the dynamic Virtual Fields Method (VFM) in which acceleration fields, clearly generated by the non-equilibrium state, are utilized as a force measurement with in the frame work of the principle of virtual work equation. In this paper, two dynamic VFM based techniques are used to characterise an EPDM rubber. These are denoted as the linear and nonlinear VFM and are developed for (respectively) medium (drop-weight) and high (gas-gun) strain-rate experiments. The use of the two VFMs combined with high-speed imaging analysed by digital imaging correlation allows the identification of the parameters of a given rubber mechanical model; in this case the Ogden model is used.

Aromatic Polyimide/Graphene Composite Organic Cathodes for Fast and Sustainable Lithium-Ion Batteries

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

Lyu, Hailong; Li, Peipei; Liu, Jiurong

A composite organic cathode material based on aromatic polyimide (PI) and highly conductive graphene was prepared through a facile in situ polymerization method for application in lithium-ion batteries. The in situ polymerization generated intimate contact between PI and electronically conductive graphene, resulting in conductive composites with highly reversible redox reactions and good structure stability. The synergistic effect between PI and graphene enabled not only a high reversible capacity of 232.6 mAh g -1 at a charge–discharge rate of C/10 but also exceptionally high-rate cycling stability, that is, a high capacity of 108.9 mAh g -1 at a very high charge–dischargemore » rate of 50C with a capacity retention of 80 % after 1000 cycles. This improved electrochemical performance resulted from the combination of stable redox reversibility of PI and high electronic conductivity of the graphene additive. In conclusion, the graphene-based composite also exhibited much better performance than composites based on multi-walled carbon nanotubes and the conductive carbon black C45 in terms of specific capacity and long-term cycling stability under the same charge–discharge rates.« less

Aromatic Polyimide/Graphene Composite Organic Cathodes for Fast and Sustainable Lithium-Ion Batteries

DOE PAGES

Lyu, Hailong; Li, Peipei; Liu, Jiurong; ...

2018-01-24

A composite organic cathode material based on aromatic polyimide (PI) and highly conductive graphene was prepared through a facile in situ polymerization method for application in lithium-ion batteries. The in situ polymerization generated intimate contact between PI and electronically conductive graphene, resulting in conductive composites with highly reversible redox reactions and good structure stability. The synergistic effect between PI and graphene enabled not only a high reversible capacity of 232.6 mAh g -1 at a charge–discharge rate of C/10 but also exceptionally high-rate cycling stability, that is, a high capacity of 108.9 mAh g -1 at a very high charge–dischargemore » rate of 50C with a capacity retention of 80 % after 1000 cycles. This improved electrochemical performance resulted from the combination of stable redox reversibility of PI and high electronic conductivity of the graphene additive. In conclusion, the graphene-based composite also exhibited much better performance than composites based on multi-walled carbon nanotubes and the conductive carbon black C45 in terms of specific capacity and long-term cycling stability under the same charge–discharge rates.« less

FAST TRACK COMMUNICATION: Deposition of amino-rich thin films by RF magnetron sputtering of nylon

NASA Astrophysics Data System (ADS)

Kylián, O.; Hanuš, J.; Choukourov, A.; Kousal, J.; Slavínská, D.; Biederman, H.

2009-07-01

RF magnetron sputtering of a nylon target in different gas mixtures was studied in order to evaluate the capability of this process to deposit amino-rich coatings needed in a wide range of biomedical applications. It has been demonstrated that both the deposition rate of the coatings and the surface density of primary amino groups are strongly linked with working gas mixture composition. From this point of view, a sufficiently high deposition rate as well as the highest amine efficiency reaching a NH2/C value of 18% was observed in the N2/H2 discharge, which leads to the surface exhibiting a high rate of protein adsorption.

Frequency-locked pulse sequencer for high-frame-rate monochromatic tissue motion imaging.

PubMed

Azar, Reza Zahiri; Baghani, Ali; Salcudean, Septimiu E; Rohling, Robert

2011-04-01

To overcome the inherent low frame rate of conventional ultrasound, we have previously presented a system that can be implemented on conventional ultrasound scanners for high-frame-rate imaging of monochromatic tissue motion. The system employs a sector subdivision technique in the sequencer to increase the acquisition rate. To eliminate the delays introduced during data acquisition, a motion phase correction algorithm has also been introduced to create in-phase displacement images. Previous experimental results from tissue- mimicking phantoms showed that the system can achieve effective frame rates of up to a few kilohertz on conventional ultrasound systems. In this short communication, we present a new pulse sequencing strategy that facilitates high-frame-rate imaging of monochromatic motion such that the acquired echo signals are inherently in-phase. The sequencer uses the knowledge of the excitation frequency to synchronize the acquisition of the entire imaging plane to that of an external exciter. This sequencing approach eliminates any need for synchronization or phase correction and has applications in tissue elastography, which we demonstrate with tissue-mimicking phantoms. © 2011 IEEE

Primary lithium batteries, some consumer considerations

NASA Technical Reports Server (NTRS)

Bro, P.

1983-01-01

In order to determine whether larger size lithium batteries would be commercially marketable, the performance of several D size lithium batteries was compared with that of an equivalent alkaline manganese battery, and the relative costs of the different systems were compared. It is concluded that opportunities exist in the consumer market for the larger sizes of the low rate and moderate rate lithium batteries, and that the high rate lithium batteries need further improvements before they can be recommended for consumer applications.

Electric field-based technologies for valorization of bioresources.

PubMed

Rocha, Cristina M R; Genisheva, Zlatina; Ferreira-Santos, Pedro; Rodrigues, Rui; Vicente, António A; Teixeira, José A; Pereira, Ricardo N

2018-04-01

This review provides an overview of recent research on electrotechnologies applied to the valorization of bioresources. Following a comprehensive summary of the current status of the application of well-known electric-based processing technologies, such as pulsed electric fields (PEF) and high voltage electrical discharges (HVED), the application of moderate electric fields (MEF) as an extraction or valorization technology will be considered in detail. MEF, known by its improved energy efficiency and claimed electroporation effects (allowing enhanced extraction yields), may also originate high heating rates - ohmic heating (OH) effect - allowing thermal stabilization of waste stream for other added-value applications. MEF is a simple technology that mostly makes use of green solvents (mainly water) and that can be used on functionalization of compounds of biological origin broadening their application range. The substantial increase of MEF-based plants installed in industries worldwide suggests its straightforward application for waste recovery. Copyright © 2018 Elsevier Ltd. All rights reserved.

Toward a reaction rate model of condensed-phase RDX decomposition under high temperatures

NASA Astrophysics Data System (ADS)

Schweigert, Igor

2014-03-01

Shock ignition of energetic molecular solids is driven by microstructural heterogeneities, at which even moderate stresses can result in sufficiently high temperatures to initiate material decomposition and the release of the chemical energy. Mesoscale modeling of these ``hot spots'' requires a chemical reaction rate model that describes the energy release with a sub-microsecond resolution and under a wide range of temperatures. No such model is available even for well-studied energetic materials such as RDX. In this presentation, I will describe an ongoing effort to develop a reaction rate model of condensed-phase RDX decomposition under high temperatures using first-principles molecular dynamics, transition-state theory, and reaction network analysis. This work was supported by the Naval Research Laboratory, by the Office of Naval Research, and by the DOD High Performance Computing Modernization Program Software Application Institute for Multiscale Reactive Modeling of Insensitive Munitions.

Toward a reaction rate model of condensed-phase RDX decomposition under high temperatures

NASA Astrophysics Data System (ADS)

Schweigert, Igor

2015-06-01

Shock ignition of energetic molecular solids is driven by microstructural heterogeneities, at which even moderate stresses can result in sufficiently high temperatures to initiate material decomposition and chemical energy release. Mesoscale modeling of these ``hot spots'' requires a reaction rate model that describes the energy release with a sub-microsecond resolution and under a wide range of temperatures. No such model is available even for well-studied energetic materials such as RDX. In this presentation, I will describe an ongoing effort to develop a reaction rate model of condensed-phase RDX decomposition under high temperatures using first-principles molecular dynamics, transition-state theory, and reaction network analysis. This work was supported by the Naval Research Laboratory, by the Office of Naval Research, and by the DoD High Performance Computing Modernization Program Software Application Institute for Multiscale Reactive Modeling of Insensitive Munitions.

N2O and CO2 emissions following repeated application of organic and mineral N fertiliser from a vegetable crop rotation.

PubMed

De Rosa, Daniele; Rowlings, David W; Biala, Johannes; Scheer, Clemens; Basso, Bruno; Grace, Peter R

2018-05-11

Accounting for nitrogen (N) release from organic amendments (OA) can reduce the use of synthetic N-fertiliser, sustain crop production, and potentially reduce soil borne greenhouse gases (GHG) emissions. However, it is difficult to assess the GHG mitigation potential for OA as a substitute of N-fertiliser over the long term due to only part of the organic N added to soil is being released in the first year after application. High-resolution nitrous oxide (N 2 O) and carbon dioxide (CO 2 ) emissions monitored from a horticultural crop rotation over 2.5 years from conventional urea application rates were compared to treatments receiving an annual application of raw and composted chicken manure combined with conventional and reduced N-fertiliser rates. The repeated application of composted manure did not increase annual N 2 O emissions while the application of raw manure resulted in N 2 O emissions up to 35.2 times higher than the zero N fertiliser treatment and up to 4.7 times higher than conventional N-fertiliser rate due to an increase in C and N availability following the repeated application of raw OA. The main factor driving N 2 O emissions was the incorporation of organic material accompanied by high soil moisture while the application of synthetic N-fertiliser induced only short-term N 2 O emission pulse. The average annual N 2 O emission factor calculated accounting for the total N applied including OA was equal to 0.27 ± 0.17%, 3.7 times lower than the IPCC default value. Accounting for the estimated N release from OA only enabled a more realistic N 2 O emission factor to be defined for organically amended field that was equal to 0.48 ± 0.3%. This study demonstrated that accounting for the N released from repeated application of composted rather than raw manure can be a viable pathway to reduce N 2 O emissions and maintain soil fertility. Copyright © 2017. Published by Elsevier B.V.

UV superconducting nanowire single-photon detectors with high efficiency, low noise, and 4 K operating temperature

NASA Astrophysics Data System (ADS)

Wollman, E. E.; Verma, V. B.; Beyer, A. D.; Briggs, R. M.; Korzh, B.; Allmaras, J. P.; Marsili, F.; Lita, A. E.; Mirin, R. P.; Nam, S. W.; Shaw, M. D.

2017-10-01

For photon-counting applications at ultraviolet wavelengths, there are currently no detectors that combine high efficiency (> 50%), sub-nanosecond timing resolution, and sub-Hz dark count rates. Superconducting nanowire single-photon detectors (SNSPDs) have seen success over the past decade for photon-counting applications in the near-infrared, but little work has been done to optimize SNSPDs for wavelengths below 400 nm. Here, we describe the design, fabrication, and characterization of UV SNSPDs operating at wavelengths between 250 and 370 nm. The detectors have active areas up to 56 ${\\mu}$m in diameter, 70 - 80% efficiency, timing resolution down to 60 ps FWHM, blindness to visible and infrared photons, and dark count rates of ~ 0.25 counts/hr for a 56 ${\\mu}$m diameter pixel. By using the amorphous superconductor MoSi, these UV SNSPDs are also able to operate at temperatures up to 4.2 K. These performance metrics make UV SNSPDs ideal for applications in trapped-ion quantum information processing, lidar studies of the upper atmosphere, UV fluorescent-lifetime imaging microscopy, and photon-starved UV astronomy.

Superconducting energy recovery linacs

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

Ben-Zvi, Ilan

High-average-power and high-brightness electron beams from a combination of laser photocathode electron guns and a superconducting energy recovery linac (ERL) is an emerging accelerator science with applications in ERL light sources, high repetition rate free electron lasers , electron cooling, electron ion colliders and more. This paper reviews the accelerator physics issues of superconducting ERLs, discusses major subsystems and provides a few examples of superconducting ERLs.

Superconducting energy recovery linacs

DOE PAGES

Ben-Zvi, Ilan

2016-09-01

High-average-power and high-brightness electron beams from a combination of laser photocathode electron guns and a superconducting energy recovery linac (ERL) is an emerging accelerator science with applications in ERL light sources, high repetition rate free electron lasers , electron cooling, electron ion colliders and more. This paper reviews the accelerator physics issues of superconducting ERLs, discusses major subsystems and provides a few examples of superconducting ERLs.

Investigating the applicability of activity-based quantum mechanics in a few high school physics classrooms

NASA Astrophysics Data System (ADS)

Escalada, Lawrence Todd

Quantum physics is not traditionally introduced in high school physics courses because of the level of abstraction and mathematical formalism associated with the subject. As part of the Visual Quantum Mechanics project, activity-based instructional units have been developed that introduce quantum principles to students who have limited backgrounds in physics and mathematics. This study investigates the applicability of one unit, Solids & Light, that introduces quantum principles within the context of learning about light emitting diodes. An observation protocol, attitude surveys, and questionnaires were used to examine the implementation of materials and student-teacher interactions in various secondary physics classrooms. Aspects of Solids & Light including the use of hands-on activities, interactive computer programs, inexpensive materials, and the focus on conceptual understanding were very applicable in the various physics classrooms observed. Both teachers and students gave these instructional strategies favorable ratings in motivating students to make observations and to learn. These ratings were not significantly affected by gender or students, attitudes towards physics or computers. Solid's & Light was applicable in terms of content and teaching style for some teachers. However, a mismatch of teaching styles between some instructors and the unit posed some problems in determining applicability. Observations indicated that some instructors were not able to utilize the exploratory instructional strategy of Solid's & Light. Thus, Solids & Light must include additional support necessary to make the instructor comfortable with the subject matter and pedagogical style. With these revisions, Solids & Light, will have all the key components to make its implementation in a high school physics classroom a successful one.

Impact of exogenous organic carbon on the removal of chemicals of concern in the high rate nitrifying trickling filters.

PubMed

Mai, Lei; van den Akker, Ben; Du, Jun; Kookana, Rai S; Fallowfield, Howard

2016-06-01

The application of fixed bed high rate nitrifying trickling filters (NTFs) for the removal of track organic chemicals of concern (CoC) is less well known than their application to nutrient removal in water treatment. Particularly, the effect of exogenous organic carbon substrate (sucrose) loading on the performance of NTFs is not well understood. A laboratory-scale NTF system was operated in recirculation mode, with the objective of removing ammonia and CoC simultaneously. The efficiency of a high rate NTF for removal both of low concentration of ammonia (5 mg NH4-N L(-1)) and different concentrations of CoC in the presence of an exogenous organic carbon substrate (30 mg total organic carbon (TOC) L(-1)) was investigated. In the presence of exogenous organic carbon, the results demonstrated that the high rate NTF was able to successfully remove most of the CoCs investigated, with the removal ranging from 20.2% to 87.54%. High removal efficiencies were observed for acetaminophen (87.54%), bisphenol A (86.60%), trimethoprim (86.24%) and 17α-ethynylestradiol (80.60%). It was followed by the medium removal efficiency for N, N-diethyl-m-toluamide (61.31%) and atrazine (56.90%). In contrast, the removal of caffeine (28.43%) and benzotriazole (20.20%) was poorer in the presence of exogenous organic carbon. The removal efficiency for CoC was also compared with the results obtained in our previous study in the absence of exogenous organic carbon. The results showed that the addition of exogenous organic carbon was able to improve the removal of some of the CoC. Significant TOC percentage removals (45.68%-84.43%) and ammonia removal rate (mean value of 0.44 mg NH4-N L(-1) h(-1)) were also achieved in this study. The findings from this study provide valuable information for optimising the efficiency of high rate NTF for the removal of ammonia, CoC and TOC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pseudocapacitive organic catechol derivative-functionalized three-dimensional graphene aerogel hybrid electrodes for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Choi, Jaewon; Yang, MinHo; Kim, Sung-Kon

2017-11-01

Bio-inspired and environmentally friendly chemical functionalization is a successful way to a new class of hybrid electrode materials for applications in energy storage. Quinone (Q)-hydroquinone (QH2) couples, a prototypical example of organic redox systems, provide fast and reversible proton-coupled electron-transfer reactions which lead to increased capacity. To achieve high capacitance and rate performance, constructing three-dimensional (3D) continuous porous structure is highly desirable. Here we report the hybrid electrodes (GA-C) consisting of 3D graphene aerogel (GA) functionalized with organic redox-active material, catechol derivative, for application to high-performance supercapacitors. The catechol derivative is adsorbed on the surface of GA through non-covalent interactions and promotes fast and reversible Q/QH2 faradaic reactions, providing large specific capacitance of 188 F g-1 at a current of 1 A g-1 and a specific energy of ∼25 Wh kg-1 at a specific power of ∼18,000 W kg-1. 3D continuous porous structure of GA electrode facilitates ion and electron transports, resulting in high rate performance (∼140 F g-1 at a current of 10 A g-1).

Free smoking cessation mobile apps available in Australia: a quality review and content analysis.

PubMed

Thornton, Louise; Quinn, Catherine; Birrell, Louise; Guillaumier, Ashleigh; Shaw, Brad; Forbes, Erin; Deady, Mark; Kay-Lambkin, Frances

2017-12-01

This review aimed to identify free, high-quality, smoking cessation mobile applications (apps) that adhere to Australian smoking cessation treatment guidelines. A systematic search of smoking cessation apps was conducted using Google. The technical quality of relevant apps was rated using the Mobile Application Rating Scale. The content of apps identified as high quality was assessed for adherence to smoking cessation treatment guidelines. 112 relevant apps were identified. The majority were of poor technical quality and only six 'high-quality' apps were identified. These apps adhered to Australian treatment guidelines in part. The efficacy of two apps had been previously evaluated. In lieu of more substantial research in this area, it is suggested that the high-quality apps identified in this review may be more likely than other available apps to encourage smoking cessation. Implications for public health: Smoking cessation apps have the potential to address many barriers that prevent smoking cessation support being provided; however few high-quality smoking cessation apps are currently available in Australia, very few have been evaluated and the app market is extremely volatile. More research to evaluate smoking cessation apps, and sustained funding for evidence-based apps, is needed. © 2017 The Authors.

Implementation of a VLSI Level Zero Processing system utilizing the functional component approach

NASA Technical Reports Server (NTRS)

Shi, Jianfei; Horner, Ward P.; Grebowsky, Gerald J.; Chesney, James R.

1991-01-01

A high rate Level Zero Processing system is currently being prototyped at NASA/Goddard Space Flight Center (GSFC). Based on state-of-the-art VLSI technology and the functional component approach, the new system promises capabilities of handling multiple Virtual Channels and Applications with a combined data rate of up to 20 Megabits per second (Mbps) at low cost.

An advanced Ni-Cd battery cell design

NASA Technical Reports Server (NTRS)

Miller, L.

1986-01-01

The evolution of an advanced Ni-Cd space battery cell design continues to prove very promising. High oxygen/hydrogen gas recombination rates (currently up to a C/5 charge rate) and increased electrolyte activation level tolerance (currently up to 5.6 grams Ah of positive capacity) were demonstrated by test. A superior performance, extended life battery cell offering advantages should soon be available for mission applications

Application of Gamification in a College STEM Introductory Course: A Case Study

ERIC Educational Resources Information Center

Machajewski, Szymon Tomasz

2017-01-01

Between 2000 and 2016, the STEM industry reportedly added jobs at the rate of 28% while all jobs were growing at only 6%. However, 48% of bachelor's degree students and 69% of associate's degree students in STEM majors left their program of study between 2003 and 2009. The high attrition rate is often attributed to low student engagement, boredom,…

Ultrashort pulsed laser (USPL) application in dentistry: basic investigations of ablation rates and thresholds on oral hard tissue and restorative materials.

PubMed

Schelle, Florian; Polz, Sebastian; Haloui, Hatim; Braun, Andreas; Dehn, Claudia; Frentzen, Matthias; Meister, Jörg

2014-11-01

Modern ultrashort pulse lasers with scanning systems provide a huge set of parameters affecting the suitability for dental applications. The present study investigates thresholds and ablation rates of oral hard tissues and restorative materials with a view towards a clinical application system. The functional system consists of a 10 W Nd:YVO4 laser emitting pulses with a duration of 8 ps at 1,064 nm. Measurements were performed on dentin, enamel, ceramic, composite, and mammoth ivory at a repetition rate of 500 kHz. By employing a scanning system, square-shaped cavities with an edge length of 1 mm were created. Ablation threshold and rate measurements were assessed by variation of the applied fluence. Examinations were carried out employing a scanning electron microscope and optical profilometer. Irradiation time was recorded by the scanner software in order to calculate the overall ablated volume per time. First high power ablation rate measurements were performed employing a laser source with up to 50 W. Threshold values in the range of 0.45 J/cm(2) (composite) to 1.54 J/cm(2) (enamel) were observed. Differences between any two materials are statistically significant (p < 0.05). Preparation speeds up to 37.53 mm(3)/min (composite) were achieved with the 10 W laser source and differed statistically significant for any two materials (p < 0.05) with the exception of dentin and mammoth ivory (p > 0.05). By employing the 50 W laser source, increased rates up to ∼50 mm(3)/min for dentin were obtained. The results indicate that modern USPL systems provide sufficient ablation rates to be seen as a promising technology for dental applications.

Application of X-Ray Computer Tomography for Observing the Central Void Formations and the Fuel Pin Deformations of Irradiated FBR Fuel Assemblies

NASA Astrophysics Data System (ADS)

Katsuyama, Kozo; Nagamine, Tsuyoshi; Furuya, Hirotaka

2010-10-01

In order to observe the structural change in the interior of irradiated fuel assemblies, a non-destructive post-irradiation examination (PIE) technique using X-ray computer tomography (X-ray CT) was developed. This X-ray CT technique was applied to observe the central void formations and fuel pin deformations of fuel assemblies which had been irradiated at high linear heat rating. The central void sizes in all fuel pins were measured on five cross sections of the core fuel column as a parameter for evaluating fuel thermal performance. In addition, the fuel pin deformations were analyzed from X-ray CT images obtained along the axial direction of a fuel assembly at the same separation interval. A dependence of void size on the linear heat rating was seen in the fuel assembly irradiated at high linear heat rating. In addition, significant undulations of the fuel pin were observed along the axial direction, coinciding with the wrapping wire pitch in the core fuel column. Application of the developed technique should provide enhanced resolution of measurements and simplify fuel PIEs.

Affordable underwater wireless optical communication using LEDs

NASA Astrophysics Data System (ADS)

Pilipenko, Vladimir; Arnon, Shlomi

2013-09-01

In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

Processing Parameters Optimization for Material Deposition Efficiency in Laser Metal Deposited Titanium Alloy

NASA Astrophysics Data System (ADS)

Mahamood, Rasheedat M.; Akinlabi, Esther T.

2016-03-01

Ti6Al4V is an important Titanium alloy that is mostly used in many applications such as: aerospace, petrochemical and medicine. The excellent corrosion resistance property, the high strength to weight ratio and the retention of properties at high temperature makes them to be favoured in most applications. The high cost of Titanium and its alloys makes their use to be prohibitive in some applications. Ti6Al4V can be cladded on a less expensive material such as steel, thereby reducing cost and providing excellent properties. Laser Metal Deposition (LMD) process, an additive manufacturing process is capable of producing complex part directly from the 3-D CAD model of the part and it also has the capability of handling multiple materials. Processing parameters play an important role in LMD process and in order to achieve desired results at a minimum cost, then the processing parameters need to be properly controlled. This paper investigates the role of processing parameters: laser power, scanning speed, powder flow rate and gas flow rate, on the material utilization efficiency in laser metal deposited Ti6Al4V. A two-level full factorial design of experiment was used in this investigation, to be able to understand the processing parameters that are most significant as well as the interactions among these processing parameters. Four process parameters were used, each with upper and lower settings which results in a combination of sixteen experiments. The laser power settings used was 1.8 and 3 kW, the scanning speed was 0.05 and 0.1 m/s, the powder flow rate was 2 and 4 g/min and the gas flow rate was 2 and 4 l/min. The experiments were designed and analyzed using Design Expert 8 software. The software was used to generate the optimized process parameters which were found to be laser power of 3.2 kW, scanning speed of 0.06 m/s, powder flow rate of 2 g/min and gas flow rate of 3 l/min.

Measuring high pressure baroreceptor sensitivity in the rat.

PubMed

Shiry, L J; Hamlin, R L

2011-01-01

The high pressure baroreceptor reflex rapidly buffers changes in systemic arterial pressure in response to postural changes, altered gravitational conditions, diseases, and pharmacological agents. Drug-induced exaggeration of changes in heart rate and in systemic arterial pressure is a leading cause of adverse events and of patients terminating use of drugs, particularly in the aging population. This paper presents a facile method for monitoring the high pressure baroreceptor reflex in rats, and presents an alternative to quantifying the magnitude of this reflex using 2 dependent variables, heart rate and systemic arterial pressure, rather than merely change in heart rate. Twenty-four rats were allocated to 3 groups: group I anesthetized with 100mg/kg thiopental, group II anesthetized with 2% isoflurane given by inhalation, group III anesthetized with thiopental but pretreated for 2weeks with 2μg/kg aldosterone given SQ bid. After induction to anesthesia, hair was clipped from the ventral aspect of the neck, and petrolatum was applied to the skin to permit an air-tight seal with a glass funnel attached to a source of variable and controllable negative pressure. Systemic arterial pressure, ECG, heart rate, and a force of suction applied to the neck were all recorded continuously. After baseline recordings, a force of -20mmHg was applied for 20s over the carotid artery. In rats receiving thiopental, the average changes in heart rate and systemic arterial pressure following the application of -20mmHg neck suction were 30±11bpm and 45±14mmHg, respectively. The ratios of change in heart and change in systemic arterial pressure to application of negative force over the carotid sinus are 1.5±0.6bpm/mmHg and 0.7±04mmHg/mmHg, respectively. Mean values for heart rate and for mean systemic arterial pressure during baseline and after application of neck suction for 20s showed little to no decrease (i.e., blunting) in rats anesthetized with isoflurane or pretreated with aldosterone. Thus this methodology was able to detect, in rats, blunting of baroreceptor function for at least 2 perturbations of this important homeostatic control system. Copyright © 2011. Published by Elsevier Inc.

Emerging applications of spark plasma sintering in all solid-state lithium-ion batteries and beyond

NASA Astrophysics Data System (ADS)

Zhu, Hongzheng; Liu, Jian

2018-07-01

Solid-state batteries have received increasing attention due to their high safety aspect and high energy and power densities. However, the development of solid-state batteries is hindered by inferior solid-solid interfaces between the solid-state electrolyte and electrode, which cause high interfacial resistance, reduced Li-ion and electron transfer rate, and limited battery performance. Recently, spark plasma sintering (SPS) is emerging as a promising technique for fabricating solid-state electrolyte and electrode pellets with clean and intimate solid-solid interfaces. During the SPS process, the unique reaction mechanism through the combination of current, pressure and high heating rate allow the formation of desirable solid-solid interfaces between active material particles. Herein, this work focuses on the overview of the application of SPS for fabricating solid-state electrolyte and electrode in all solid-state Li-ion batteries, and beyond, such as solid-state Li-S and Na-ion batteries. The correlations among SPS parameters, interfacial resistance, and electrochemical properties of solid-state electrolytes and electrodes are discussed for different material systems. In the end, we point out future opportunities and challenges associated with SPS application in the hot area of solid-state batteries. It is expected that this timely review will stimulate more fundamental and applied research in the development of solid-state batteries by SPS.

Impacts of agricultural management and climate change on future soil organic carbon dynamics in North China Plain.

PubMed

Wang, Guocheng; Li, Tingting; Zhang, Wen; Yu, Yongqiang

2014-01-01

Dynamics of cropland soil organic carbon (SOC) in response to different management practices and environmental conditions across North China Plain (NCP) were studied using a modeling approach. We identified the key variables driving SOC changes at a high spatial resolution (10 km × 10 km) and long time scale (90 years). The model used future climatic data from the FGOALS model based on four future greenhouse gas (GHG) concentration scenarios. Agricultural practices included different rates of nitrogen (N) fertilization, manure application, and stubble retention. We found that SOC change was significantly influenced by the management practices of stubble retention (linearly positive), manure application (linearly positive) and nitrogen fertilization (nonlinearly positive) - and the edaphic variable of initial SOC content (linearly negative). Temperature had weakly positive effects, while precipitation had negligible impacts on SOC dynamics under current irrigation management. The effects of increased N fertilization on SOC changes were most significant between the rates of 0 and 300 kg ha-1 yr-1. With a moderate rate of manure application (i.e., 2000 kg ha-1 yr-1), stubble retention (i.e., 50%), and an optimal rate of nitrogen fertilization (i.e., 300 kg ha-1 yr-1), more than 60% of the study area showed an increase in SOC, and the average SOC density across NCP was relatively steady during the study period. If the rates of manure application and stubble retention doubled (i.e., manure application rate of 4000 kg ha-1 yr-1 and stubble retention rate of 100%), soils across more than 90% of the study area would act as a net C sink, and the average SOC density kept increasing from 40 Mg ha-1 during 2010s to the current worldwide average of ∼ 55 Mg ha-1 during 2060s. The results can help target agricultural management practices for effectively mitigating climate change through soil C sequestration.

Impacts of Agricultural Management and Climate Change on Future Soil Organic Carbon Dynamics in North China Plain

PubMed Central

Wang, Guocheng; Li, Tingting; Zhang, Wen; Yu, Yongqiang

2014-01-01

Dynamics of cropland soil organic carbon (SOC) in response to different management practices and environmental conditions across North China Plain (NCP) were studied using a modeling approach. We identified the key variables driving SOC changes at a high spatial resolution (10 km×10 km) and long time scale (90 years). The model used future climatic data from the FGOALS model based on four future greenhouse gas (GHG) concentration scenarios. Agricultural practices included different rates of nitrogen (N) fertilization, manure application, and stubble retention. We found that SOC change was significantly influenced by the management practices of stubble retention (linearly positive), manure application (linearly positive) and nitrogen fertilization (nonlinearly positive) – and the edaphic variable of initial SOC content (linearly negative). Temperature had weakly positive effects, while precipitation had negligible impacts on SOC dynamics under current irrigation management. The effects of increased N fertilization on SOC changes were most significant between the rates of 0 and 300 kg ha−1 yr−1. With a moderate rate of manure application (i.e., 2000 kg ha−1 yr−1), stubble retention (i.e., 50%), and an optimal rate of nitrogen fertilization (i.e., 300 kg ha−1 yr−1), more than 60% of the study area showed an increase in SOC, and the average SOC density across NCP was relatively steady during the study period. If the rates of manure application and stubble retention doubled (i.e., manure application rate of 4000 kg ha−1 yr−1 and stubble retention rate of 100%), soils across more than 90% of the study area would act as a net C sink, and the average SOC density kept increasing from 40 Mg ha−1 during 2010s to the current worldwide average of ∼55 Mg ha−1 during 2060s. The results can help target agricultural management practices for effectively mitigating climate change through soil C sequestration. PMID:24722689

The clinical applicability of a daily summary of patients' self-reported postoperative pain-A repeated measure analysis.

PubMed

Wikström, Lotta; Eriksson, Kerstin; Fridlund, Bengt; Nilsson, Mats; Årestedt, Kristofer; Broström, Anders

2017-12-01

(i) To determine whether a central tendency, median, based on patients' self-rated pain is a clinically applicable daily measure to show patients' postoperative pain on the first day after major surgery (ii) and to determine the number of self-ratings required for the calculation of this measure. Perioperative pain traits in medical records are difficult to overview. The clinical applicability of a daily documented summarising measure of patients' self-rated pain scores is little explored. A repeated measure design was carried out at three Swedish country hospitals. Associations between the measures were analysed with nonparametric statistical methods; systematic and individual group changes were analysed separately. Measure I: pain scores at rest and activity postoperative day 1; measure II: retrospective average pain from postoperative day 1. The sample consisted of 190 general surgery patients and 289 orthopaedic surgery patients with a mean age of 65; 56% were men. Forty-four percent had a pre-operative daily intake of analgesia, and 77% used postoperative opioids. A range of 4-9 pain scores seem to be eligible for the calculation of the daily measures of pain. Rank correlations for individual median scores, based on four ratings, vs. retrospective self-rated average pain, were moderate and strengthened with increased numbers of ratings. A systematic group change towards a higher level of reported retrospective pain was significant. The median values were clinically applicable daily measures. The risk of obtaining a higher value than was recalled by patients seemed to be low. Applicability increased with increased frequency of self-rated pain scores and with high-quality pain assessments. The documenting of daily median pain scores at rest and during activity could constitute the basis for obtaining patients' experiences by showing their pain severity trajectories. The measures could also be an important key to predicting postoperative health-related consequences. © 2017 John Wiley & Sons Ltd.

International epidemiology of child and adolescent psychopathology ii: integration and applications of dimensional findings from 44 societies.

PubMed

Rescorla, Leslie; Ivanova, Masha Y; Achenbach, Thomas M; Begovac, Ivan; Chahed, Myriam; Drugli, May Britt; Emerich, Deisy Ribas; Fung, Daniel S S; Haider, Mariam; Hansson, Kjell; Hewitt, Nohelia; Jaimes, Stefanny; Larsson, Bo; Maggiolini, Alfio; Marković, Jasminka; Mitrović, Dragan; Moreira, Paulo; Oliveira, João Tiago; Olsson, Martin; Ooi, Yoon Phaik; Petot, Djaouida; Pisa, Cecilia; Pomalima, Rolando; da Rocha, Marina Monzani; Rudan, Vlasta; Sekulić, Slobodan; Shahini, Mimoza; de Mattos Silvares, Edwiges Ferreira; Szirovicza, Lajos; Valverde, José; Vera, Luis Anderssen; Villa, Maria Clara; Viola, Laura; Woo, Bernardine S C; Zhang, Eugene Yuqing

2012-12-01

To build on Achenbach, Rescorla, and Ivanova (2012) by (a) reporting new international findings for parent, teacher, and self-ratings on the Child Behavior Checklist, Youth Self-Report, and Teacher's Report Form; (b) testing the fit of syndrome models to new data from 17 societies, including previously underrepresented regions; (c) testing effects of society, gender, and age in 44 societies by integrating new and previous data; (d) testing cross-society correlations between mean item ratings; (e) describing the construction of multisociety norms; (f) illustrating clinical applications. Confirmatory factor analyses (CFAs) of parent, teacher, and self-ratings, performed separately for each society; tests of societal, gender, and age effects on dimensional syndrome scales, DSM-oriented scales, Internalizing, Externalizing, and Total Problems scales; tests of agreement between low, medium, and high ratings of problem items across societies. CFAs supported the tested syndrome models in all societies according to the primary fit index (Root Mean Square Error of Approximation [RMSEA]), but less consistently according to other indices; effect sizes were small-to-medium for societal differences in scale scores, but very small for gender, age, and interactions with society; items received similarly low, medium, or high ratings in different societies; problem scores from 44 societies fit three sets of multisociety norms. Statistically derived syndrome models fit parent, teacher, and self-ratings when tested individually in all 44 societies according to RMSEAs (but less consistently according to other indices). Small to medium differences in scale scores among societies supported the use of low-, medium-, and high-scoring norms in clinical assessment of individual children. Copyright © 2012 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

License plate recognition (phase B).

DOT National Transportation Integrated Search

2010-06-01

License Plate Recognition (LPR) technology has been used for off-line automobile enforcement purposes. The technology has seen mixed success with correct reading rate as high as 60 to 80% depending on the specific application and environment. This li...

REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

EPA Science Inventory

Large refrigeration systems are found in several applications including supermarkets, cold storage warehouses, and industrial processes. The sizes of these systems are a contributing factor to their problems of high refrigerant leak rates because of the thousands of connections, ...

Lysine-based polycation:heparin coacervate for controlled protein delivery.

PubMed

Johnson, Noah Ray; Ambe, Trisha; Wang, Yadong

2014-01-01

Polycations have good potential as carriers of proteins and genetic material. However, poor control over the release rate and safety issues currently limit their use as delivery vehicles. Here we introduce a new lysine-based polycation, poly(ethylene lysinylaspartate diglyceride) (PELD), which exhibits high cytocompatibility. PELD self-assembles with the biological polyanion heparin into a coacervate that incorporates proteins with high loading efficiency. Coacervates of varying surface charge were obtained by simple alteration of the PELD:heparin ratio and resulted in diverse release profiles of the model protein bovine serum albumin. Therefore, coacervate charge represents a direct means of control over release rate and duration. The PELD coacervate also rapidly adsorbed onto a porous polymeric scaffold, demonstrating potential use in tissue engineering applications. This coacervate represents a safe and tunable protein delivery system for biomedical applications. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A road to practical dielectric elastomer actuators based robotics and mechatronics: discrete actuation

NASA Astrophysics Data System (ADS)

Plante, Jean-Sébastien; Devita, Lauren M.; Dubowsky, Steven

2007-04-01

Fundamental studies of Dielectric Elastomer Actuators (DEAs) using viscoelastic materials such as VHB 4905/4910 from 3M showed significant advantages at high stretch rates. The film's viscous forces increase actuator life and the short power-on times minimize energy losses through current leakage. This paper presents a design paradigm that exploits these fundamental properties of DEAs called discrete actuation. Discrete actuation uses DEAs at high stretch rates to change the states of robotic or mechatronic systems in discrete steps. Each state of the system is stable and can be maintained without actuator power. Discrete actuation can be used in robotic and mechatronic applications such as manipulation and locomotion. The resolution of such systems increases with the number of discrete states, 10 to 100 being sufficient for many applications. An MRI-guided needle positioning device for cancer treatments and a space exploration robot using hopping for locomotion are presented as examples of this concept.

The High-efficiency LED Driver for Visible Light Communication Applications

PubMed Central

Gong, Cihun-Siyong Alex; Lee, Yu-Chen; Lai, Jyun-Liang; Yu, Chueh-Hao; Huang, Li Ren; Yang, Chia-Yen

2016-01-01

This paper presents a LED driver for VLC. The main purpose is to solve the low data rate problem used to be in switching type LED driver. The GaN power device is proposed to replace the traditional silicon power device of switching LED driver for the purpose of increasing switching frequency of converter, thereby increasing the bandwidth of data transmission. To achieve high efficiency, the diode-connected GaN power transistor is utilized to replace the traditional ultrafast recovery diode used to be in switching type LED driver. This work has been experimentally evaluated on 350-mA output current. The results demonstrate that it supports the data of PWM dimming level encoded in the PPM scheme for VLC application. The experimental results also show that system’s efficiency of 80.8% can be achieved at 1-Mb/s data rate. PMID:27498921

Kilohertz binary phase modulator for pulsed laser sources using a digital micromirror device.

PubMed

Hoffmann, Maximilian; Papadopoulos, Ioannis N; Judkewitz, Benjamin

2018-01-01

The controlled modulation of an optical wavefront is required for aberration correction, digital phase conjugation, or patterned photostimulation. For most of these applications, it is desirable to control the wavefront modulation at the highest rates possible. The digital micromirror device (DMD) presents a cost-effective solution to achieve high-speed modulation and often exceeds the speed of the more conventional liquid crystal spatial light modulator but is inherently an amplitude modulator. Furthermore, spatial dispersion caused by DMD diffraction complicates its use with pulsed laser sources, such as those used in nonlinear microscopy. Here we introduce a DMD-based optical design that overcomes these limitations and achieves dispersion-free high-speed binary phase modulation. We show that this phase modulation can be used to switch through binary phase patterns at the rate of 20 kHz in two-photon excitation fluorescence applications.

Kilohertz binary phase modulator for pulsed laser sources using a digital micromirror device

NASA Astrophysics Data System (ADS)

Hoffmann, Maximilian; Papadopoulos, Ioannis N.; Judkewitz, Benjamin

2018-01-01

The controlled modulation of an optical wavefront is required for aberration correction, digital phase conjugation or patterned photostimulation. For most of these applications it is desirable to control the wavefront modulation at the highest rates possible. The digital micromirror device (DMD) presents a cost-effective solution to achieve high-speed modulation and often exceeds the speed of the more conventional liquid crystal spatial light modulator, but is inherently an amplitude modulator. Furthermore, spatial dispersion caused by DMD diffraction complicates its use with pulsed laser sources, such as those used in nonlinear microscopy. Here we introduce a DMD-based optical design that overcomes these limitations and achieves dispersion-free high-speed binary phase modulation. We show that this phase modulation can be used to switch through binary phase patterns at the rate of 20 kHz in two-photon excitation fluorescence applications.

Rapid and accurate reversed-phase high-performance liquid chromatographic determination of conjugated bile acids in human bile for routine clinical applications. Therapeutic control during gallstone dissolution therapy.

PubMed

Swobodnik, W; Klüppelberg, U; Wechsler, J G; Volz, M; Normandin, G; Ditschuneit, H

1985-05-03

This paper introduces a new method to detect the taurine and glycine conjugates of five different bile acids (cholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid and lithocholic acid) in human bile. Advantages of this method are sufficient separation of compounds within a short period of time and a high rate of reproducibility. Using a mobile phase gradient of acetonitrile and water, modified with tetrabutylammonium hydrogen sulphate (0.0075 mol/l), we were able to maximize the differentiation between ursodeoxycholic acid and lithocholic acid, which is of primary interest during conservative gallstone dissolution therapy. Use of this gradient reduced analysis time to less than 0.5 h. Recovery rates for this modified method ranged from 94% to 100%, and reproducibility was 98%, sufficient for routine clinical applications.

Silicon force sensor

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

Galambos, Paul C.; Crenshaw, Thomas B.; Nishida, Erik E.

The various technologies presented herein relate to a sensor for measurement of high forces and/or high load shock rate(s), whereby the sensor utilizes silicon as the sensing element. A plate of Si can have a thinned region formed therein on which can be formed a number of traces operating as a Wheatstone bridge. The brittle Si can be incorporated into a layered structure comprising ductile and/or compliant materials. The sensor can have a washer-like configuration which can be incorporated into a nut and bolt configuration, whereby tightening of the nut and bolt can facilitate application of a compressive preload uponmore » the sensor. Upon application of an impact load on the bolt, the compressive load on the sensor can be reduced (e.g., moves towards zero-load), however the magnitude of the preload can be such that the load on the sensor does not translate to tensile stress being applied to the sensor.« less

Application of Hydrodynamic Cavitation for Food and Bioprocessing

NASA Astrophysics Data System (ADS)

Gogate, Parag R.

Hydrodynamic cavitation can be simply generated by the alterations in the flow field in high speed/high pressure devices and also by passage of the liquid through a constriction such as orifice plate, venturi, or throttling valve. Hydrodynamic cavitation results in the formation of local hot spots, release of highly reactive free radicals, and enhanced mass transfer rates due to turbulence generated as a result of liquid circulation currents. These conditions can be suitably applied for intensification of different bioprocessing applications in an energy-efficient manner as compared to conventionally used ultrasound-based reactors. The current chapter aims at highlighting different aspects related to hydrodynamic cavitation, including the theoretical aspects for optimization of operating parameters, reactor designs, and overview of applications relevant to food and bioprocessing. Some case studies highlighting the comparison of hydrodynamic cavitation and acoustic cavitation reactors will also be discussed.

Low nitrous oxide production through nitrifier-denitrification in intermittent-feed high-rate nitritation reactors.

PubMed

Su, Qingxian; Ma, Chun; Domingo-Félez, Carlos; Kiil, Anne Sofie; Thamdrup, Bo; Jensen, Marlene Mark; Smets, Barth F

2017-10-15

Nitrous oxide (N 2 O) production from autotrophic nitrogen conversion processes, especially nitritation systems, can be significant, requires understanding and calls for mitigation. In this study, the rates and pathways of N 2 O production were quantified in two lab-scale sequencing batch reactors operated with intermittent feeding and demonstrating long-term and high-rate nitritation. The resulting reactor biomass was highly enriched in ammonia-oxidizing bacteria, and converted ∼93 ± 14% of the oxidized ammonium to nitrite. The low DO set-point combined with intermittent feeding was sufficient to maintain high nitritation efficiency and high nitritation rates at 20-26 °C over a period of ∼300 days. Even at the high nitritation efficiencies, net N 2 O production was low (∼2% of the oxidized ammonium). Net N 2 O production rates transiently increased with a rise in pH after each feeding, suggesting a potential effect of pH on N 2 O production. In situ application of 15 N labeled substrates revealed nitrifier denitrification as the dominant pathway of N 2 O production. Our study highlights operational conditions that minimize N 2 O emission from two-stage autotrophic nitrogen removal systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

[The present status of aspirin use for primary prevention among hypertensive outpatients in China].

PubMed

Liu, J; Zhao, D; Liu, J; Qi, Y; Sun, J Y; Wang, W

2016-04-01

To evaluate the current status of aspirin for primary prevention in hypertensive outpatients in China, and the gap between aspirin use and guidelines. This was a multi-center cross-sectional study and carried out in hypertensive patients from 46 hospitals of twenty two cities in China from June to December in 2009. At least 100 essential hypertensive outpatients were consecutively recruited from each participant hospitals according to the consistent inclusion criteria. The patients underwent physical examinations and biochemical analyses, and answered questionnaires. Based on the relevant guidelines, the risk assessment of cardiovascular disease (CVD) is a prerequisite for the proper use of aspirin in primary prevention. A total of 5 206 hypertensive outpatients were included. Among them, 1 324 (25.4%) were with a history of CVD. Among those with no history of CVD, 2 705 patients (69.7%) were at high risk of CVD, and the aspirin utilization rate for primary prevention was 29.2%, with 32.2% patients at high risk and 22.4% patients at low-medium risk of CVD, respectively. In the application of aspirin for CVD primary prevention, the inappropriate aspirin use rate in patients at low-medium risk was 23.3%. The proportion of subjects at high risk for CVD is high in hypertensive outpatients suggesting a wide range of application space for aspirin.There exists underutilization for high risk and overutilization for low-medium risk patients in current aspirin primary prevention application.

Trends and new developments in gaseous detectors

NASA Astrophysics Data System (ADS)

Hoch, M.

Almost one century ago the method of particle detection with gaseous detectors was invented. Since then they have been exploited successfully in many experiments using a wide variety of different applications. The development is still going on today. The underlying working principles are today well understood and with the help of modern simulation techniques, new configurations can be easily examined and optimized before a first experimental test. Traditional wire chamber ensembles demonstrate that they are still up to date and are well prepared to meet also the challenges of LHC. Applications will be discussed using TPCs in high multiplicity environments with standard Multi-Wire Proportional Chamber (MWPC) as readout as well as drift tubes in a muon spectrometer for a Large Hardron Collider (LHC) experiment. Triggered by the evolving printed circuit technology, a new generation of gaseous detectors with very high position resolution and rate capability has emerged. Two representatives (MICROMEGAS, GEM) have proved their reliability in various experiments and are promising candidates for future projects. Performance and results will be discussed for these detectors. Furthermore, achievements in RPC-based detectors will be discussed. The standard Trigger RPC is a reliable low-cost semi-industrial manufactured device with good time resolution. Thin gap RPCs (Multigap-, and High Rate Timing RPC) show very fast signal response at high efficiency and significantly increased rate capability and will be applied in TOF detectors.

Application of Glomus sp. and Pseudomonas diminuta Reduce the Use of Chemical Fertilizers in Production of Potato Grown on Different Soil Types

NASA Astrophysics Data System (ADS)

Nurbaity, A.; Sofyan, E. T.; Hamdani, J. S.

2016-08-01

The use of high chemical fertilizer rates in potato production has been applied on the farm in Indonesia. Application of biofertilizer consists of arbuscular mycorrhizal fungi has been tested to reduce the use of NPK rates in production of potato and to determine whether different soil types will have different response to this biofertilizer. A greenhouse experiment was conducted using mixtures of spores of Glomus sp. and inoculant of mycorrhizal helper bacteria Pseudomonas diminuta, applied at different rates of NPK fertilizer (0, 25, 50, 75 and 100% of recommended rates) and different soil types (Andisols and Inceptisols). Results of experiment showed that application of Glomus sp. and P. diminuta reduced the use of NPK up to 50%, where the growth (plant height and tuber number), N,P,K uptake and tuber yields of potato had similar effect to the highest recommendation rate of NPK fertilizer. Inceptisols in general had better response to the biofertiliser compared to Andisols. Findings from this experiment confirmed the evidences that biofertilizer could reduce the use of chemical fertilizer, and the widely distributed soil in Indonesia such as Inceptisols, is potential to be used as a medium for potato production.

Multi-application controls: Robust nonlinear multivariable aerospace controls applications

NASA Technical Reports Server (NTRS)

Enns, Dale F.; Bugajski, Daniel J.; Carter, John; Antoniewicz, Bob

1994-01-01

This viewgraph presentation describes the general methodology used to apply Honywell's Multi-Application Control (MACH) and the specific application to the F-18 High Angle-of-Attack Research Vehicle (HARV) including piloted simulation handling qualities evaluation. The general steps include insertion of modeling data for geometry and mass properties, aerodynamics, propulsion data and assumptions, requirements and specifications, e.g. definition of control variables, handling qualities, stability margins and statements for bandwidth, control power, priorities, position and rate limits. The specific steps include choice of independent variables for least squares fits to aerodynamic and propulsion data, modifications to the management of the controls with regard to integrator windup and actuation limiting and priorities, e.g. pitch priority over roll, and command limiting to prevent departures and/or undesirable inertial coupling or inability to recover to a stable trim condition. The HARV control problem is characterized by significant nonlinearities and multivariable interactions in the low speed, high angle-of-attack, high angular rate flight regime. Systematic approaches to the control of vehicle motions modeled with coupled nonlinear equations of motion have been developed. This paper will discuss the dynamic inversion approach which explicity accounts for nonlinearities in the control design. Multiple control effectors (including aerodynamic control surfaces and thrust vectoring control) and sensors are used to control the motions of the vehicles in several degrees-of-freedom. Several maneuvers will be used to illustrate performance of MACH in the high angle-of-attack flight regime. Analytical methods for assessing the robust performance of the multivariable control system in the presence of math modeling uncertainty, disturbances, and commands have reached a high level of maturity. The structured singular value (mu) frequency response methodology is presented as a method for analyzing robust performance and the mu-synthesis method will be presented as a method for synthesizing a robust control system. The paper concludes with the author's expectations regarding future applications of robust nonlinear multivariable controls.

Polymicrobial Gardnerella biofilm resists repeated intravaginal antiseptic treatment in a subset of women with bacterial vaginosis: a preliminary report.

PubMed

Swidsinski, Alexander; Loening-Baucke, Vera; Swidsinski, Sonja; Verstraelen, Hans

2015-03-01

Bacterial vaginosis is a recalcitrant polymicrobial biofilm infection that often resists standard antibiotic treatment. We therefore considered repeated treatment with octenidine, a local antiseptic that has previously been shown to be highly effective in several biofilm-associated infections. Twenty-four patients with recurrent BV were treated with a 7-day course of octenidine (octenidine dihydrochloride spray application with the commercial product Octenisept). In case of treatment failure or relapse within 6 months, patients were re-treated with a 28-day course of octenidine. In case of recurrence within 6 months after the second treatment course, patients were treated again with a 28-day course followed by weekly applications for 2 months. Treatment effect was evaluated by assessment of the presence of the biofilm on voided vaginal epithelial cells through fluorescence in situ hybridisation. The initial cure rate following a 7-day course of octenidine was as high as 87.5%. The 6-month relapse rate was, however, as high as 66.6%. Repeated treatment for 28 days led to an overall cure rate of 75.0%; however, it was also associated with emergence of complete resistance to octenidine in a subset of women. The overall cure rate after three treatment courses with 1-year follow-up was 62.5 %, with 37.5 % of the patients showing complete resistance to octenidine. Our preliminary results showed that octenidine dihydrochloride was initially highly effective, but the efficacy of repeated and prolonged treatment dropped quickly as challenge with the antiseptic rapidly led to bacterial resistance in a considerable subset of women.

Electronic cameras for low-light microscopy.

PubMed

Rasnik, Ivan; French, Todd; Jacobson, Ken; Berland, Keith

2013-01-01

This chapter introduces to electronic cameras, discusses the various parameters considered for evaluating their performance, and describes some of the key features of different camera formats. The chapter also presents the basic understanding of functioning of the electronic cameras and how these properties can be exploited to optimize image quality under low-light conditions. Although there are many types of cameras available for microscopy, the most reliable type is the charge-coupled device (CCD) camera, which remains preferred for high-performance systems. If time resolution and frame rate are of no concern, slow-scan CCDs certainly offer the best available performance, both in terms of the signal-to-noise ratio and their spatial resolution. Slow-scan cameras are thus the first choice for experiments using fixed specimens such as measurements using immune fluorescence and fluorescence in situ hybridization. However, if video rate imaging is required, one need not evaluate slow-scan CCD cameras. A very basic video CCD may suffice if samples are heavily labeled or are not perturbed by high intensity illumination. When video rate imaging is required for very dim specimens, the electron multiplying CCD camera is probably the most appropriate at this technological stage. Intensified CCDs provide a unique tool for applications in which high-speed gating is required. The variable integration time video cameras are very attractive options if one needs to acquire images at video rate acquisition, as well as with longer integration times for less bright samples. This flexibility can facilitate many diverse applications with highly varied light levels. Copyright © 2007 Elsevier Inc. All rights reserved.

The application of high-speed TV-holography to time-resolved vibration measurements

NASA Astrophysics Data System (ADS)

Buckberry, C.; Reeves, M.; Moore, A. J.; Hand, D. P.; Barton, J. S.; Jones, J. D. C.

1999-10-01

We describe an electronic speckle pattern interferometer (ESPI) system that has enabled non-harmonic vibrations to be measured with μs temporal resolution. The short exposure period and high framing rate of a high-speed camera at up to 40,500 frames per second allow low-power CW laser illumination and fibre-optic beam delivery to be used, rather than the high peak power pulsed lasers normally used in ESPI for transient measurement. The technique has been demonstrated in the laboratory and tested in preliminary industrial trials. The ability to measure vibration with high spatial and temporal resolution, which is not provided by techniques such as scanning laser vibrometry, has many applications in manufacturing design, and in an illustrative application described here revealed previously unmeasured “rocking” vibrations of a car door. It has been possible to make the measurement on the door as part of a complete vehicle standing on its own tyres, wheels and suspension, and where the excitation was generated by the running of the vehicle's own engine.

High-authority smart material integrated electric actuator

NASA Astrophysics Data System (ADS)

Weisensel, G. N.; Pierce, Thomas D.; Zunkel, Gary

1997-05-01

For many current applications, hydraulic power is still the preferred method of gaining mechanical advantage. However, in many of these applications, this power comes with the penalties of high weight, size, cost, and maintenance due to the system's distributed nature and redundancy requirements. A high authority smart material Integrated Electric Actuator (IEA) is a modular, self-contained linear motion device that is capable of producing dynamic output strokes similar to those of hydraulic actuators yet at significantly reduced weight and volume. It provides system simplification and miniaturization. This actuator concept has many innovative features, including a TERFENOL-D-based pump, TERFENOL-D- based active valves, control algorithms, a displacement amplification unit and integrated, unitized packaging. The IEA needs only electrical power and a control command signal as inputs to provide high authority, high response rate actuation. This approach is directly compatible with distributed control strategies. Aircraft control, automotive brakes and fuel injection, and fluid power delivery are just some examples of the IEA's pervasive applications in aerospace, defense and commercial systems.

Burning Graphene Layer-by-Layer

PubMed Central

Ermakov, Victor A.; Alaferdov, Andrei V.; Vaz, Alfredo R.; Perim, Eric; Autreto, Pedro A. S.; Paupitz, Ricardo; Galvao, Douglas S.; Moshkalev, Stanislav A.

2015-01-01

Graphene, in single layer or multi-layer forms, holds great promise for future electronics and high-temperature applications. Resistance to oxidation, an important property for high-temperature applications, has not yet been extensively investigated. Controlled thinning of multi-layer graphene (MLG), e.g., by plasma or laser processing is another challenge, since the existing methods produce non-uniform thinning or introduce undesirable defects in the basal plane. We report here that heating to extremely high temperatures (exceeding 2000 K) and controllable layer-by-layer burning (thinning) can be achieved by low-power laser processing of suspended high-quality MLG in air in “cold-wall” reactor configuration. In contrast, localized laser heating of supported samples results in non-uniform graphene burning at much higher rates. Fully atomistic molecular dynamics simulations were also performed to reveal details of oxidation mechanisms leading to uniform layer-by-layer graphene gasification. The extraordinary resistance of MLG to oxidation paves the way to novel high-temperature applications as continuum light source or scaffolding material. PMID:26100466

Network-linked long-time recording high-speed video camera system

NASA Astrophysics Data System (ADS)

Kimura, Seiji; Tsuji, Masataka

2001-04-01

This paper describes a network-oriented, long-recording-time high-speed digital video camera system that utilizes an HDD (Hard Disk Drive) as a recording medium. Semiconductor memories (DRAM, etc.) are the most common image data recording media with existing high-speed digital video cameras. They are extensively used because of their advantage of high-speed writing and reading of picture data. The drawback is that their recording time is limited to only several seconds because the data amount is very large. A recording time of several seconds is sufficient for many applications. However, a much longer recording time is required in some applications where an exact prediction of trigger timing is hard to make. In the Late years, the recording density of the HDD has been dramatically improved, which has attracted more attention to its value as a long-recording-time medium. We conceived an idea that we would be able to build a compact system that makes possible a long time recording if the HDD can be used as a memory unit for high-speed digital image recording. However, the data rate of such a system, capable of recording 640 X 480 pixel resolution pictures at 500 frames per second (fps) with 8-bit grayscale is 153.6 Mbyte/sec., and is way beyond the writing speed of the commonly used HDD. So, we developed a dedicated image compression system and verified its capability to lower the data rate from the digital camera to match the HDD writing rate.

Quantitative X-ray - UV Line and Continuum Spectroscopy with Application to AGN: State-Specific Hydrogenic Recombination Cooling Coefficients for a Wide Range of Conditions

NASA Technical Reports Server (NTRS)

LaMothe, J.; Ferland, Gary J.

2002-01-01

Recombination cooling, in which a free electron emits light while being captured to an ion, is an important cooling process in photoionized clouds that are optically thick or have low metallicity. State specific rather than total recombination cooling rates are needed since the hydrogen atom tends to become optically thick in high-density regimes such as Active Galactic Nuclei. This paper builds upon previous work to derive the cooling rate over the full temperature range where the process can be a significant contributor in a photoionized plasma. We exploit the fact that the recombination and cooling rates are given by intrinsically similar formulae to express the cooling rate in terms of the closely related radiative recombination rate. We give an especially simple but accurate approximation that works for any high hydrogenic level and can be conveniently employed in large-scale numerical simulations.

Highly crumpled solar reduced graphene oxide electrode for supercapacitor application

NASA Astrophysics Data System (ADS)

Mohanapriya, K.; Ahirrao, Dinesh J.; Jha, Neetu

2018-04-01

Highly crumpled solar reduced graphene oxide (CSRGO) was synthesized by simple and rapid method through freezing the solar reduced graphene oxide aqueous suspension using liquid nitrogen and used as electrode material for supercapacitor application. This electrode material was characterized by transmission electron microscope (TEM), X-Ray diffractometer (XRD) and Raman Spectroscopy techniques to understand the morphology and structure. The electrochemical performance was studied by cyclic voltammetry (CV), galvanostatic charge/discharge (CD) and electrochemical impedance spectroscopy (EIS) using 6M KOH electrolyte. The CSRGO exhibit high specifc capacitance of 210.1 F g-1 at the current density of 0.5 A g-1 and shows excellent rate capability. These features make the CSRGO material as promising electrode for high-performance supercapacitors.

Application of a Threshold Method to Airborne-Spaceborne Attenuating-Wavelength Radars for the Estimation of Space-Time Rain-Rate Statistics.

NASA Astrophysics Data System (ADS)

Meneghini, Robert

1998-09-01

A method is proposed for estimating the area-average rain-rate distribution from attenuating-wavelength spaceborne or airborne radar data. Because highly attenuated radar returns yield unreliable estimates of the rain rate, these are eliminated by means of a proxy variable, Q, derived from the apparent radar reflectivity factors and a power law relating the attenuation coefficient and the reflectivity factor. In determining the probability distribution function of areawide rain rates, the elimination of attenuated measurements at high rain rates and the loss of data at light rain rates, because of low signal-to-noise ratios, leads to truncation of the distribution at the low and high ends. To estimate it over all rain rates, a lognormal distribution is assumed, the parameters of which are obtained from a nonlinear least squares fit to the truncated distribution. Implementation of this type of threshold method depends on the method used in estimating the high-resolution rain-rate estimates (e.g., either the standard Z-R or the Hitschfeld-Bordan estimate) and on the type of rain-rate estimate (either point or path averaged). To test the method, measured drop size distributions are used to characterize the rain along the radar beam. Comparisons with the standard single-threshold method or with the sample mean, taken over the high-resolution estimates, show that the present method usually provides more accurate determinations of the area-averaged rain rate if the values of the threshold parameter, QT, are chosen in the range from 0.2 to 0.4.

Nanostructure of highly aromatic graphene nanosheets -- From optoelectronics to electrochemical energy storage applications

NASA Astrophysics Data System (ADS)

Biswas, Sanjib

The exceptional electrical properties along with intriguing physical and chemical aspects of graphene nanosheets can only be realized by nanostructuring these materials through the homogeneous and orderly distribution of these nanosheets without compromising the aromaticity of the native basal plane. Graphene nanosheets prepared by direct exfoliation as opposed to the graphene oxide route are necessary in order to preserve the native chemical properties of graphene basal planes. This research has been directed at optimally combining the diverse physical and chemical aspects of graphene nanosheets such as particle size, surface area and edge chemistry to fabricate nanostructured architectures for optoelectronics and high power electrochemical energy storage applications. In the first nanostructuring effort, a monolayer of these ultrathin, highly hydrophobic graphene nanosheets was prepared on a large area substrate via self-assembly at the liquid-liquid interface. Driven by the minimization of interfacial energy these planar graphene nanosheets produce a close packed monolayer structure at the liquid-liquid interface. The resulting monolayer film exhibits high electrical conductivity of more than 1000 S/cm and an optical transmission of more than 70-80% between wavelengths of 550 nm and 2000 nm making it an ideal candidate for optoelectronic applications. In the second part of this research, nanostructuring was used to create a configuration suitable for supercapacitor applications. A free standing, 100% binder free multilayer, flexible film consisting of monolayers of graphene nanosheets was prepared by utilizing the van der Waals forces of attraction between the basal plans of the graphene nanosheets coupled with capillary driven and drying-induced collapse. A major benefit in this approach is that the graphene nanosheet's attractive physical and chemical characteristics can be synthesized into an architecture consisting of large and small nanosheets to create an aligned network designed to maximize device performance. Monolayers of large sized graphene nanosheets function as highly electrically conducting current collectors within a mesoporous network of smaller graphene nanosheets for improved rate capability of the electrical double layer capacitor (EDLC) electrode. This nano-architecture produces an electrode with superior performance for high power EDLC applications: a high frequency capacitative response; a nearly rectangular cyclic voltammogram at a scanning rate of 1000 mv/sec; a rapid current response; small equivalent series resistance (ESR); and fast ionic diffusion. Integration of this nanostructured graphene nanosheet architecture with conductive polymers or metal oxide nanostructurcs was also investigated to produce similar multilayered structures for electrochemical energy storage applications. These inexpensive graphene nanosheets coupled with this facile and robust nanostructuring process make both this new material and method highly advantageous for many potential applications ranging from optoelectronics to high power electrochemical energy storage applications.

45 CFR 148.310 - Eligibility requirements for a grant.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Qualified High Risk Pools § 148.310 Eligibility requirements for a grant. A State must meet all of the following requirements to be eligible for a grant: (a) The State has a qualified high risk pool as defined... the premium for applicable standard risk rates for the State. (c) The pool offers a choice of two or...

Silvicultural technology and applications for forest plantation establishment west of the Cascade crest.

Treesearch

Timothy B. Harrington; Jeff Madsen

2005-01-01

Research and operational trials have identified methods of forest plantation establishment that promote high rates of survival and early growth of tree seedlings in the Pacific Northwest. Primary reasons for this success are the intensive control of competing vegetation provided by herbicide treatments and the planting of high quality seedlings. This paper discusses...

Ultrahigh speed en face OCT capsule for endoscopic imaging

PubMed Central

Liang, Kaicheng; Traverso, Giovanni; Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Wang, Zhao; Potsaid, Benjamin; Giacomelli, Michael; Jayaraman, Vijaysekhar; Barman, Ross; Cable, Alex; Mashimo, Hiroshi; Langer, Robert; Fujimoto, James G.

2015-01-01

Depth resolved and en face OCT visualization in vivo may have important clinical applications in endoscopy. We demonstrate a high speed, two-dimensional (2D) distal scanning capsule with a micromotor for fast rotary scanning and a pneumatic actuator for precision longitudinal scanning. Longitudinal position measurement and image registration were performed by optical tracking of the pneumatic scanner. The 2D scanning device enables high resolution imaging over a small field of view and is suitable for OCT as well as other scanning microscopies. Large field of view imaging for screening or surveillance applications can also be achieved by proximally pulling back or advancing the capsule while scanning the distal high-speed micromotor. Circumferential en face OCT was demonstrated in living swine at 250 Hz frame rate and 1 MHz A-scan rate using a MEMS tunable VCSEL light source at 1300 nm. Cross-sectional and en face OCT views of the upper and lower gastrointestinal tract were generated with precision distal pneumatic longitudinal actuation as well as proximal manual longitudinal actuation. These devices could enable clinical studies either as an adjunct to endoscopy, attached to an endoscope, or as a swallowed tethered capsule for non-endoscopic imaging without sedation. The combination of ultrahigh speed imaging and distal scanning capsule technology could enable both screening and surveillance applications. PMID:25909001

Ultrahigh speed en face OCT capsule for endoscopic imaging.

PubMed

Liang, Kaicheng; Traverso, Giovanni; Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Wang, Zhao; Potsaid, Benjamin; Giacomelli, Michael; Jayaraman, Vijaysekhar; Barman, Ross; Cable, Alex; Mashimo, Hiroshi; Langer, Robert; Fujimoto, James G

2015-04-01

Depth resolved and en face OCT visualization in vivo may have important clinical applications in endoscopy. We demonstrate a high speed, two-dimensional (2D) distal scanning capsule with a micromotor for fast rotary scanning and a pneumatic actuator for precision longitudinal scanning. Longitudinal position measurement and image registration were performed by optical tracking of the pneumatic scanner. The 2D scanning device enables high resolution imaging over a small field of view and is suitable for OCT as well as other scanning microscopies. Large field of view imaging for screening or surveillance applications can also be achieved by proximally pulling back or advancing the capsule while scanning the distal high-speed micromotor. Circumferential en face OCT was demonstrated in living swine at 250 Hz frame rate and 1 MHz A-scan rate using a MEMS tunable VCSEL light source at 1300 nm. Cross-sectional and en face OCT views of the upper and lower gastrointestinal tract were generated with precision distal pneumatic longitudinal actuation as well as proximal manual longitudinal actuation. These devices could enable clinical studies either as an adjunct to endoscopy, attached to an endoscope, or as a swallowed tethered capsule for non-endoscopic imaging without sedation. The combination of ultrahigh speed imaging and distal scanning capsule technology could enable both screening and surveillance applications.

Preschool children's taste acceptance of highly concentrated fluoride compounds: effects on nonverbal behavior.

PubMed

Kolb, Anne-Kathrin; Schmied, Kirsten; Fassheber, Peter; Heinrich-Weltzien, Roswitha

2013-01-01

The aim of this video-based study was to examine the taste acceptance of children between the ages of 2 and 5 years regarding highly concentrated fluoride preparations in kindergarten-based preventive programs. The fluoride preparation Duraphat was applied to 16 children, Elmex fluid to 15 children, and Fluoridin N5 to 14 children. The procedure was conducted according to a standardized protocol and videotaped Three raters evaluated the children's nonverbal behavior as a measure of taste acceptance on the Frankl Behavior Rating Scale. The interrater reliability (intraclass correlation coefficient; ICC) was .86. In an interview, children indicated the taste of the fluoride preparations on a three-point "smiley" rating scale. The interviewer used a hand puppet during the survey to establish confidence between the children and examiners. Children's nonverbal behavior was significantly more positive after Fluoridin N5 and Duraphat were applied compared to the application of Elmex fluid. The same trend was found during the smiley assessment. The response of children who displayed cooperative positive behavior before the application of fluoride preparations was significantly more positive than those who displayed uncooperative negative behavior. To achieve a high acceptance of the application of fluoride preparations among preschool children, flavorful preparations should be used.

PLASMA DEVICE

DOEpatents

Baker, W.R.; Brathenahl, A.; Furth, H.P.

1962-04-10

A device for producing a confined high temperature plasma is described. In the device the concave inner surface of an outer annular electrode is disposed concentrically about and facing the convex outer face of an inner annular electrode across which electrodes a high potential is applied to produce an electric field there between. Means is provided to create a magnetic field perpendicular to the electric field and a gas is supplied at reduced pressure in the area therebetween. Upon application of the high potential, the gas between the electrodes is ionized, heated, and under the influence of the electric and magnetic fields there is produced a rotating annular plasma disk. The ionized plasma has high dielectric constant properties. The device is useful as a fast discharge rate capacitor, in controlled thermonuclear research, and other high temperature gas applications. (AEC)

Effects of nitrogen application rate and a nitrification inhibitor dicyandiamide on ammonia oxidizers and N2O emissions in a grazed pasture soil.

PubMed

Dai, Yu; Di, Hong J; Cameron, Keith C; He, Ji-Zheng

2013-11-01

Ammonia oxidizers, including ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) are important drivers of a key step of the nitrogen cycle - nitrification, which affects the production of the potent greenhouse gas, nitrous oxide (N2O). A field experiment was conducted to determine the effect of nitrogen application rates and the nitrification inhibitor dicyandiamide (DCD) on the abundance of AOB and AOA and on N2O emissions in a grazed pasture soil. Nitrogen (N) was applied at four different rates, with urea applied at 50 and 100 kg N ha(-1) and animal urine at 300 and 600 kg N ha(-1). DCD was applied to some of the N treatments at 10 kg ha(-1). The results showed that the AOB amoA gene copy numbers were greater than those of AOA. The highest ratio of the AOB to AOA amoA gene copy numbers was 106.6 which occurred in the urine-N 600 treatment. The AOB amoA gene copy numbers increased with increasing nitrogen application rates. DCD had a significant impact in reducing the AOB amoA gene copy numbers especially in the high nitrogen application rates. N2O emissions increased with the N application rates. DCD had the most significant effect in reducing the daily and total N2O emissions in the highest nitrogen application rate. The greatest reduction of total N2O emissions by DCD was 69% in the urine-N 600 treatment. The reduction in the N2O emission factor by DCD ranged from 58% to 83%. The N2O flux and NO3(-)-N concentrations were significantly correlated to the growth of AOB, rather than AOA. This study confirms the importance of AOB in nitrification and the effect of DCD in inhibiting AOB growth and in decreasing N2O emissions in grazed pasture soils under field conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

Application of a Threshold Method to the TRMM Radar for the Estimation of Space-Time Rain Rate Statistics

NASA Technical Reports Server (NTRS)

Meneghini, Robert; Jones, Jeffrey A.

1997-01-01

One of the TRMM radar products of interest is the monthly-averaged rain rates over 5 x 5 degree cells. Clearly, the most directly way of calculating these and similar statistics is to compute them from the individual estimates made over the instantaneous field of view of the Instrument (4.3 km horizontal resolution). An alternative approach is the use of a threshold method. It has been established that over sufficiently large regions the fractional area above a rain rate threshold and the area-average rain rate are well correlated for particular choices of the threshold [e.g., Kedem et al., 19901]. A straightforward application of this method to the TRMM data would consist of the conversion of the individual reflectivity factors to rain rates followed by a calculation of the fraction of these that exceed a particular threshold. Previous results indicate that for thresholds near or at 5 mm/h, the correlation between this fractional area and the area-average rain rate is high. There are several drawbacks to this approach, however. At the TRMM radar frequency of 13.8 GHz the signal suffers attenuation so that the negative bias of the high resolution rain rate estimates will increase as the path attenuation increases. To establish a quantitative relationship between fractional area and area-average rain rate, an independent means of calculating the area-average rain rate is needed such as an array of rain gauges. This type of calibration procedure, however, is difficult for a spaceborne radar such as TRMM. To estimate a statistic other than the mean of the distribution requires, in general, a different choice of threshold and a different set of tuning parameters.

Tile Drainage Nitrate Losses and Corn Yield Response to Fall and Spring Nitrogen Management.

PubMed

Pittelkow, Cameron M; Clover, Matthew W; Hoeft, Robert G; Nafziger, Emerson D; Warren, Jeffery J; Gonzini, Lisa C; Greer, Kristin D

2017-09-01

Nitrogen (N) management strategies that maintain high crop productivity with reduced water quality impacts are needed for tile-drained landscapes of the US Midwest. The objectives of this study were to determine the effect of N application rate, timing, and fall nitrapyrin addition on tile drainage nitrate losses, corn ( L.) yield, N recovery efficiency, and postharvest soil nitrate content over 3 yr in a corn-soybean [ (L.) Merr.] rotation. In addition to an unfertilized control, the following eight N treatments were applied as anhydrous ammonia in a replicated, field-scale experiment with both corn and soybean phases present each year in Illinois: fall and spring applications of 78, 156, and 234 kg N ha, fall application of 156 kg N ha + nitrapyrin, and sidedress (V5-V6) application of 156 kg N ha. Across the 3-yr study period, increases in flow-weighted NO concentrations were found with increasing N rate for fall and spring N applications, whereas N load results were variable. At the same N rate, spring vs. fall N applications reduced flow-weighted NO concentrations only in the corn-soybean-corn rotation. Fall nitrapyrin and sidedress N treatments did not decrease flo8w-weighted NO concentrations in either rotation compared with fall and spring N applications, respectively, or increase corn yield, crop N uptake, or N recovery efficiency in any year. This study indicates that compared with fall N application, spring and sidedress N applications (for corn-soybean-corn) and sidedress N applications (for soybean-corn-soybean) reduced 3-yr mean flow-weighted NO concentrations while maintaining yields. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

High-rate tensile properties of Si-reduced TRIP sheet steels

NASA Astrophysics Data System (ADS)

Choi, Ildong; Park, Yeongdo; Son, Dongmin; Kim, Sung-Joon; Moon, Manbeen

2010-02-01

There have been efforts to develop Si-reduced TRIP steels to improve the wettability of Zn coatings, since the conventional CMnSi-TRIP steels suffer from poor galvanizability. In addition, for the development of potential applications of Si-reduced TRIP steels in vehicle crash management, a better understanding of high strain rate properties is required. In the present study, the effects of alloying elements, such as Cu, Al, Si, and P, on the high-rate tensile properties of Si-reduced TRIP sheet steels were investigated. Tensile tests were performed with a servo-hydraulic tensile testing machine at strain rates ranging from 10-2 to 6 × 102 s-1, and the ultimate tensile strength, elongation, strain rate sensitivity, and absorbed energy were evaluated. The retained austenite volume fractions and carbon content of the specimens were measured using neutron diffraction. The UTS was increased with Cu, Al, Si, and P alloying throughout the strain rate range, and the alloying effect on UTS was considerable with Cu and P. The effects of alloying on the microstructure were not significant. All the steels tested in this study exhibited positive strain rate sensitivity, and the m value at strain rates higher than 10 s-1 was at least two times higher than that at lower strain rates.

One-step fabrication of porous GaN crystal membrane and its application in energy storage

NASA Astrophysics Data System (ADS)

Zhang, Lei; Wang, Shouzhi; Shao, Yongliang; Wu, Yongzhong; Sun, Changlong; Huo, Qin; Zhang, Baoguo; Hu, Haixiao; Hao, Xiaopeng

2017-03-01

Single-crystal gallium nitride (GaN) membranes have great potential for a variety of applications. However, fabrication of single-crystalline GaN membranes remains a challenge owing to its chemical inertness and mechanical hardness. This study prepares large-area, free-standing, and single-crystalline porous GaN membranes using a one-step high-temperature annealing technique for the first time. A promising separation model is proposed through a comprehensive study that combines thermodynamic theories analysis and experiments. Porous GaN crystal membrane is processed into supercapacitors, which exhibit stable cycling life, high-rate capability, and ultrahigh power density, to complete proof-of-concept demonstration of new energy storage application. Our results contribute to the study of GaN crystal membranes into a new stage related to the elelctrochemical energy storage application.