The trapped-particle instability in the Boeing 1kW FEL oscillator

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

Ramos, L.; Blau, J.; Colson, W.B.

1995-12-31

The new design for the Boeing High Average Power Free Electron Laser will operate at 1KW average power (0.63 {mu}m) with a peak current of 132A. Simulations are used to investigate the trapped-particle instability and diffraction effects. Incorporating large desynchronism may prove to be a useful method of controlling the trapped-particle instability.

Multilevel analysis of school anti-smoking education and current cigarette use among South African students

PubMed Central

Talley, Brandon; Masyn, Katherine; Chandora, Rachna; Vivolo-Kantor, Alana

2017-01-01

Introduction South Africa (SA) implemented the Global Youth Tobacco Survey (GYTS) four times between 1999 and 2011. Data from the four surveys indicated that downward trends in cigarette use among students may have stalled. Understanding the effect of school anti-smoking education on current smoking among students within schools and variability across schools may provide important insights into policies aimed at preventing or reducing tobacco use among students. The objective was to assess the student- and school-level effects of students' exposure to school anti-smoking education on current cigarette use among the study population using the most recent wave of GYTS data in SA (2011). Methods An analytic sample of students 13-15 years of age was selected (n=3,068) from the SA GYTS 2011. A taxonomy of two-level logistic regression models was fit to assess the relationship of various tobacco use, control, and exposure predictor variables on current cigarette smoking among the study population. Results At the student-level in the full model, secondhand smoke (SHS) exposure, peer smoking, and ownership of a promotional item were significantly associated with higher risk of current smoking. At the school-level in the full model, average exposure to peer smoking was associated with significant increases in the prevalence of current cigarette use, while average family anti-smoking education was significantly associated with decreases in the outcome variable. School anti-smoking education was not a statistically significant predictor at the student- or school-levels. Conclusion in this study, exposure to school anti-smoking education had no association with current cigarette smoking among the study population. Consistent with previous studies, having peers that smoked was highly associated with a student being a current smoker. Interestingly, at the school-level in the multilevel analysis, schools with higher rates of average family anti-smoking education had lower prevalence of current smoking. This finding has potential implications for tobacco control in SA, particularly if the school-level, family-centered protective effect can be operationalized as a prevention tool in the country's tobacco control program. PMID:28451015

An Improved Distributed Secondary Control Method for DC Microgrids With Enhanced Dynamic Current Sharing Performance

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

Wang, Panbao; Lu, Xiaonan; Yang, Xu

This paper proposes an improved distributed secondary control scheme for dc microgrids (MGs), aiming at overcoming the drawbacks of conventional droop control method. The proposed secondary control scheme can remove the dc voltage deviation and improve the current sharing accuracy by using voltage-shifting and slope-adjusting approaches simultaneously. Meanwhile, the average value of droop coefficients is calculated, and then it is controlled by an additional controller included in the distributed secondary control layer to ensure that each droop coefficient converges at a reasonable value. Hence, by adjusting the droop coefficient, each participating converter has equal output impedance, and the accurate proportionalmore » load current sharing can be achieved with different line resistances. Furthermore, the current sharing performance in steady and transient states can be enhanced by using the proposed method. The effectiveness of the proposed method is verified by detailed experimental tests based on a 3 × 1 kW prototype with three interface converters.« less

[Comparison of HbA1c, fructosamine and the main metabolic parameters in a non-insulin-dependent diabetic population].

PubMed

Magnati, G; Arsenio, L; Baroni, M C; Bodria, P; Bossi, S; Delsignore, R; Ippolito, L; Mineo, F; Strata, A

1990-01-01

Our objective was the checking of clinical data obtainable from the assay of some parameters in NID diabetic individuals. To this end, we studied 133 patients--57 males and 76 females, average age 74.36 +/- 1.01 years, 72.6% of which were above 65 years of age. The control population was subdivided as follows: 50 subjects, 26 F and 24 M; average age 71.25 +/- 1.32 years, with normal glucidic tolerance as assessed by OGTT. Current glycemia, average glycemia, fructosamine, glycosylated hemoglobin, triglycerides, LDL-cholesterol and apolipoprotein B were obviously much higher than normal in the individuals admitted to the study. A statistically significant correlation was found between average glycemia, glycosylated hemoglobin, LDL-cholesterol and blood triglycerides (p less than 0.05). No correlation was found between current glycemia, fructosamine and glycosylated hemoglobin. Similarly, serum fructosamine was unrelated to the parameters studied. In our study, fructosamine, glycosylated hemoglobin and current glycemia offered unrelatable data. Hence, in our opinion it is necessary to assay these three parameters contemporaneously for a reliable assessment of metabolic compensation.

Effect of positive pulse charge waveforms on the energy efficiency of lead-acid traction cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1981-01-01

The effects of four different charge methods on the energy conversion efficiency of 300 ampere hour lead acid traction cells were investigated. Three of the methods were positive pulse charge waveforms; the fourth, a constant current method, was used as a baseline of comparison. The positive pulse charge waveforms were: 120 Hz full wave rectified sinusoidal; 120 Hz silicon controlled rectified; and 1 kHz square wave. The constant current charger was set at the time average pulse current of each pulse waveform, which was 150 amps. The energy efficiency does not include charger losses. The lead acid traction cells were charged to 70 percent of rated ampere hour capacity in each case. The results of charging the cells using the three different pulse charge waveforms indicate there was no significant difference in energy conversion efficiency when compared to constant current charging at the time average pulse current value.

Description and evaluation of the Acoustic Profiling of Ocean Currents (APOC) system used on R. V. Oceanus cruise 96 on 11-22 May 1981

NASA Technical Reports Server (NTRS)

Joyce, T. M.; Rintoul, S. R., Jr.; Barbour, R. L.

1982-01-01

The underway current profiling system which consists of a microprocessor controlled data logger that collects and formats data from a four beam Ametek-Straza 300 kHz acoustic Doppler current profiler, heading from the ship's gyrocompass, and navigation information from a Loran-C receiver and a satellite navigation unit is discussed. Data are recorded on magnetic tape and real time is calculated. Time averaging is required to remove effects of ship motion. An intercomparison is made with a moored vector measuring current meter (VMCM). The mean difference in hourly averaged APOC and VMCM currents over the four hour intercomparison is a few mm s minus including: two Gulf Stream crossings, a warm core ring survey, and shallow water in a frontal zone to the east of Nantucket Shoals.

Stochastic optimal control as non-equilibrium statistical mechanics: calculus of variations over density and current

NASA Astrophysics Data System (ADS)

Chernyak, Vladimir Y.; Chertkov, Michael; Bierkens, Joris; Kappen, Hilbert J.

2014-01-01

In stochastic optimal control (SOC) one minimizes the average cost-to-go, that consists of the cost-of-control (amount of efforts), cost-of-space (where one wants the system to be) and the target cost (where one wants the system to arrive), for a system participating in forced and controlled Langevin dynamics. We extend the SOC problem by introducing an additional cost-of-dynamics, characterized by a vector potential. We propose derivation of the generalized gauge-invariant Hamilton-Jacobi-Bellman equation as a variation over density and current, suggest hydrodynamic interpretation and discuss examples, e.g., ergodic control of a particle-within-a-circle, illustrating non-equilibrium space-time complexity.

Modeling, simulation and control of pulsed DE-GMA welding process for joining of aluminum to steel

NASA Astrophysics Data System (ADS)

Zhang, Gang; Shi, Yu; Li, Jie; Huang, Jiankang; Fan, Ding

2014-09-01

Joining of aluminum to steel has attracted significant attention from the welding research community, automotive and rail transportation industries. Many current welding methods have been developed and applied, however, they can not precisely control the heat input to work-piece, they are high costs, low efficiency and consist lots of complex welding devices, and the generated intermetallic compound layer in weld bead interface is thicker. A novel pulsed double electrode gas metal arc welding(Pulsed DE-GMAW) method is developed. To achieve a stable welding process for joining of aluminum to steel, a mathematical model of coupled arc is established, and a new control scheme that uses the average feedback arc voltage of main loop to adjust the wire feed speed to control coupled arc length is proposed and developed. Then, the impulse control simulation of coupled arc length, wire feed speed and wire extension is conducted to demonstrate the mathematical model and predict the stability of welding process by changing the distance of contact tip to work-piece(CTWD). To prove the proposed PSO based PID control scheme's feasibility, the rapid prototyping experimental system is setup and the bead-on-plate control experiments are conducted to join aluminum to steel. The impulse control simulation shows that the established model can accurately represent the variation of coupled arc length, wire feed speed and the average main arc voltage when the welding process is disturbed, and the developed controller has a faster response and adjustment, only runs about 0.1 s. The captured electric signals show the main arc voltage gradually closes to the supposed arc voltage by adjusting the wire feed speed in 0.8 s. The obtained typical current waveform demonstrates that the main current can be reduced by controlling the bypass current under maintaining a relative large total current. The control experiment proves the accuracy of proposed model and feasibility of new control scheme further. The beautiful and smooth weld beads are also obtained by this method. Pulsed DE-GMAW can thus be considered as an alternative method for low cost, high efficiency joining of aluminum to steel.

Combined EEG-fNIRS decoding of motor attempt and imagery for brain switch control: an offline study in patients with tetraplegia.

PubMed

Blokland, Yvonne; Spyrou, Loukianos; Thijssen, Dick; Eijsvogels, Thijs; Colier, Willy; Floor-Westerdijk, Marianne; Vlek, Rutger; Bruhn, Jorgen; Farquhar, Jason

2014-03-01

Combining electrophysiological and hemodynamic features is a novel approach for improving current performance of brain switches based on sensorimotor rhythms (SMR). This study was conducted with a dual purpose: to test the feasibility of using a combined electroencephalogram/functional near-infrared spectroscopy (EEG-fNIRS) SMR-based brain switch in patients with tetraplegia, and to examine the performance difference between motor imagery and motor attempt for this user group. A general improvement was found when using both EEG and fNIRS features for classification as compared to using the single-modality EEG classifier, with average classification rates of 79% for attempted movement and 70% for imagined movement. For the control group, rates of 87% and 79% were obtained, respectively, where the "attempted movement" condition was replaced with "actual movement." A combined EEG-fNIRS system might be especially beneficial for users who lack sufficient control of current EEG-based brain switches. The average classification performance in the patient group for attempted movement was significantly higher than for imagined movement using the EEG-only as well as the combined classifier, arguing for the case of a paradigm shift in current brain switch research.

A Sensorless Predictive Current Controlled Boost Converter by Using an EKF with Load Variation Effect Elimination Function

PubMed Central

Tong, Qiaoling; Chen, Chen; Zhang, Qiao; Zou, Xuecheng

2015-01-01

To realize accurate current control for a boost converter, a precise measurement of the inductor current is required to achieve high resolution current regulating. Current sensors are widely used to measure the inductor current. However, the current sensors and their processing circuits significantly contribute extra hardware cost, delay and noise to the system. They can also harm the system reliability. Therefore, current sensorless control techniques can bring cost effective and reliable solutions for various boost converter applications. According to the derived accurate model, which contains a number of parasitics, the boost converter is a nonlinear system. An Extended Kalman Filter (EKF) is proposed for inductor current estimation and output voltage filtering. With this approach, the system can have the same advantages as sensored current control mode. To implement EKF, the load value is necessary. However, the load may vary from time to time. This can lead to errors of current estimation and filtered output voltage. To solve this issue, a load variation elimination effect elimination (LVEE) module is added. In addition, a predictive average current controller is used to regulate the current. Compared with conventional voltage controlled system, the transient response is greatly improved since it only takes two switching cycles for the current to reach its reference. Finally, experimental results are presented to verify the stable operation and output tracking capability for large-signal transients of the proposed algorithm. PMID:25928061

Transient analysis of a solid oxide fuel cell stack with crossflow configuration

NASA Astrophysics Data System (ADS)

Yuan, P.; Liu, S. F.

2018-05-01

This study investigates the transient response of the cell temperature and current density of a solid oxide fuel cell having 6 stacks with crossflow configuration. A commercial software repeatedly solves the governing equations of each stack, and get the convergent results of the whole SOFC stack. The preliminary results indicate that the average current density of each stack is similar to others, so the power output between different stacks are uniform. Moreover, the average cell temperature among stacks is different, and the central stacks have higher temperature due to its harder heat dissipation. For the operating control, the cell temperature difference among stacks is worth to concern because the temperature difference will be over 10 °C in the analysis case. The increasing of the inlet flow rate of the fuel and air will short the transient state, increase the average current density, and drop the cell temperature difference among the stacks. Therefore, the inlet flow rate is an important factor for transient performance of a SOFC stack.

Apparatus and method for controlling plating uniformity

DOEpatents

Hachman Jr., John T.; Kelly, James J.; West, Alan C.

2004-10-12

The use of an insulating shield for improving the current distribution in an electrochemical plating bath is disclosed. Numerical analysis is used to evaluate the influence of shield shape and position on plating uniformity. Simulation results are compared to experimental data for nickel deposition from a nickel--sulfamate bath. The shield is shown to improve the average current density at a plating surface.

Risk Analysis of Loblolly Pine Controlled Mass Pollination Program

Treesearch

T.D. Byram; F.E. Bridgwater

1999-01-01

The economic success of controlled mass pollination (CMP) depends both upon the value of the genetic gain obtained and the cost per seed. Crossing the best six loblolly pine (Pinus taeda) parents currently available in each deployment region of the Western Gulf Forest Tree Improvement Program will produce seed with an average additional gain in mean...

Nasal potential difference: Best or average result for CFTR function as diagnostic criteria for cystic fibrosis?

PubMed

Keenan, Katherine; Avolio, Julie; Rueckes-Nilges, Claudia; Tullis, Elizabeth; Gonska, Tanja; Naehrlich, Lutz

2015-05-01

The current practice of averaging the nasal potential difference (NPD) results of right and left nostril measurements reduce inter-individual variability but may underestimate individual CFTR function. Best NPD response to Cl(-)-free and isoproterenol perfusion (=largest ΔPD(0Cl/Iso)) from the right and left nostril was compared to the average result in 13 cystic fibrosis (CF), 78 query-CF patients and 22 healthy controls from 2 cohorts. Despite moderate to good correlation (p<0.001) between right and left measured ΔPD(0Cl/Iso), we observed large differences in some individuals. A comparison of average versus best ΔPD(0Cl/Iso) showed only moderate agreement (Giessen κ=0.538; Toronto κ=0.607). Averaging ΔPD(0Cl/Iso) showed a lower composite chloride response compared to best ΔPD(0Cl/Iso) and altered diagnostic NPD interpretation in 30 of 113 (27%) subjects. The current practice of averaging the NPD results of right and left nostril measurements leads to an underestimation of the individual CFTR function and should be reconsidered. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Measuring static seated pressure distributions and risk for skin pressure ulceration in ice sledge hockey players.

PubMed

Darrah, Shaun D; Dicianno, Brad E; Berthold, Justin; McCoy, Andrew; Haas, Matthew; Cooper, Rory A

2016-01-01

To determine whether sledge hockey players with physical disability have higher average seated pressures compared to non-disabled controls. Fifteen age-matched controls without physical disability and 15 experimental participants with physical disability were studied using a pressure mapping device to determine risk for skin pressure ulceration and the impact of cushioning and knee angle positioning on seated pressure distributions. Regardless of participant group, cushioning, or knee angle, average seated pressures exceeded clinically acceptable seated pressures. Controls had significantly higher average seated pressures than the disability group when knees were flexed, both with the cushion (p = 0.013) and without (p = 0.015). Knee extension showed significantly lower average pressures in controls, both with the cushion (p < 0.001) and without (p < 0.001). Placement of the cushion resulted in significantly lower average pressure in controls when knees were extended (p = 0.024) but not when flexed (p = 0.248). Placement of the cushion resulted in no difference in pressure (p = 0.443) in the disability group. Pressures recorded indicate high risk for skin ulceration. Cushioning was effective only in the control group with knees extended. That knee extension significantly lowered average seated pressures is important, as many sledge hockey players utilize positioning with larger knee flexion angles. Implications for Rehabilitation Ice sledge hockey is a fast growing adaptive sport. Adaptive sports have been associated with several positive improvements in overall health and quality of life, though may be putting players at risk for skin ulceration. Measured static seated pressure in sledges greatly exceeds current clinically accepted clinical guidelines. With modern improvements in wheelchair pressure relief/cushioning there are potential methods for improvement of elevated seated pressure in ice hockey sledges.

Effect of positive pulse charge waveforms on cycle life of nickel-zinc cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1980-01-01

Five amp-hour nickel-zinc cells were life cycled to evaluate four different charge methods. Three of the four waveforms investigated were 120 Hz full wave rectified sinusoidal (FWRS), 120 Hz silicon controlled rectified (SCR), and 1 kHz square wave (SW). The fourth, a constant current method, was used as a baseline of comparison. Three sealed Ni-Zn cells connected in series were cycled. Each series string was charged at an average c/20 rate, and discharged at a c/2.5 rate to a 75% rated depth. Results indicate that the relatively inexpensive 120 Hz FWRS charger appears feasible for charging 5 amp-hour nickel-zinc cells with no significant loss in average cycle life when compared to constant current charging. The 1-kHz SW charger could also be used with no significant loss in average cycle life, and suggests the possibility of utilizing the existing electric vehicle chopper controller circuitry for an on-board charger. There was an apparent difference using the 120 Hz SCR charger compared to the others, however, this difference could be due to an inadvertent severe overcharge, which occurred prior to cell failure. The remaining two positive pulse charging waveforms, FWRS and 1 kHz, did not improve the cycle life of 5 amp-hour nickel-zinc cells over that of constant current charging.

Analysis of Different Cost Functions in the Geosect Airspace Partitioning Tool

NASA Technical Reports Server (NTRS)

Wong, Gregory L.

2010-01-01

A new cost function representing air traffic controller workload is implemented in the Geosect airspace partitioning tool. Geosect currently uses a combination of aircraft count and dwell time to select optimal airspace partitions that balance controller workload. This is referred to as the aircraft count/dwell time hybrid cost function. The new cost function is based on Simplified Dynamic Density, a measure of different aspects of air traffic controller workload. Three sectorizations are compared. These are the current sectorization, Geosect's sectorization based on the aircraft count/dwell time hybrid cost function, and Geosect s sectorization based on the Simplified Dynamic Density cost function. Each sectorization is evaluated for maximum and average workload along with workload balance using the Simplified Dynamic Density as the workload measure. In addition, the Airspace Concept Evaluation System, a nationwide air traffic simulator, is used to determine the capacity and delay incurred by each sectorization. The sectorization resulting from the Simplified Dynamic Density cost function had a lower maximum workload measure than the other sectorizations, and the sectorization based on the combination of aircraft count and dwell time did a better job of balancing workload and balancing capacity. However, the current sectorization had the lowest average workload, highest sector capacity, and the least system delay.

Cost analysis of impacts of climate change on regional air quality.

PubMed

Liao, Kuo-Jen; Tagaris, Efthimios; Russell, Armistead G; Amar, Praveen; He, Shan; Manomaiphiboon, Kasemsan; Woo, Jung-Hun

2010-02-01

Climate change has been predicted to adversely impact regional air quality with resulting health effects. Here a regional air quality model and a technology analysis tool are used to assess the additional emission reductions required and associated costs to offset impacts of climate change on air quality. Analysis is done for six regions and five major cities in the continental United States. Future climate is taken from a global climate model simulation for 2049-2051 using the Intergovernmental Panel on Climate Change (IPCC) A1B emission scenario, and emission inventories are the same as current ones to assess impacts of climate change alone on air quality and control expenses. On the basis of the IPCC A1B emission scenario and current control technologies, least-cost sets of emission reductions for simultaneously offsetting impacts of climate change on regionally averaged 4th highest daily maximum 8-hr average ozone and yearly averaged PM2.5 (particulate matter [PM] with an aerodynamic diameter less than 2.5 microm) for the six regions examined are predicted to range from $36 million (1999$) yr(-1) in the Southeast to $5.5 billion yr(-1) in the Northeast. However, control costs to offset climate-related pollutant increases in urban areas can be greater than the regional costs because of the locally exacerbated ozone levels. An annual cost of $4.1 billion is required for offsetting climate-induced air quality impairment in 2049-2051 in the five cities alone. Overall, an annual cost of $9.3 billion is estimated for offsetting climate change impacts on air quality for the six regions and five cities examined. Much of the additional expense is to reduce increased levels of ozone. Additional control costs for offsetting the impacts everywhere in the United States could be larger than the estimates in this study. This study shows that additional emission controls and associated costs for offsetting climate impacts could significantly increase currently estimated control requirements and should be considered in developing control strategies for achieving air quality targets in the future.

Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan

PubMed Central

Hsiao, Hsin-I; Jan, Man-Ser; Chi, Hui-Ju

2016-01-01

This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA) models (including autoregression, seasonality, and a lag-time effect) were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity) on the incidence of V. parahaemolyticus in Taiwan between 2000 and 2011. The results indicated that average temperature (+), ocean temperature (+), ocean salinity of 6 months ago (+), maximum daily rainfall (current (−) and one month ago (−)), and average relative humidity (current and 9 months ago (−)) had significant impacts on the incidence of V. parahaemolyticus. Our findings offer a novel view of the quantitative relationship between climate change and food poisoning by V. parahaemolyticus in Taiwan. An early warning system based on climate change information for the disease control management is required in future. PMID:26848675

Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan.

PubMed

Hsiao, Hsin-I; Jan, Man-Ser; Chi, Hui-Ju

2016-02-03

This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA) models (including autoregression, seasonality, and a lag-time effect) were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity) on the incidence of V. parahaemolyticus in Taiwan between 2000 and 2011. The results indicated that average temperature (+), ocean temperature (+), ocean salinity of 6 months ago (+), maximum daily rainfall (current (-) and one month ago (-)), and average relative humidity (current and 9 months ago (-)) had significant impacts on the incidence of V. parahaemolyticus. Our findings offer a novel view of the quantitative relationship between climate change and food poisoning by V. parahaemolyticus in Taiwan. An early warning system based on climate change information for the disease control management is required in future.

The B-dot Earth Average Magnetic Field

NASA Technical Reports Server (NTRS)

Capo-Lugo, Pedro A.; Rakoczy, John; Sanders, Devon

2013-01-01

The average Earth's magnetic field is solved with complex mathematical models based on mean square integral. Depending on the selection of the Earth magnetic model, the average Earth's magnetic field can have different solutions. This paper presents a simple technique that takes advantage of the damping effects of the b-dot controller and is not dependent of the Earth magnetic model; but it is dependent on the magnetic torquers of the satellite which is not taken into consideration in the known mathematical models. Also the solution of this new technique can be implemented so easily that the flight software can be updated during flight, and the control system can have current gains for the magnetic torquers. Finally, this technique is verified and validated using flight data from a satellite that it has been in orbit for three years.

The architecture design of a 2mW 18-bit high speed weight voltage type DAC based on dual weight resistance chain

NASA Astrophysics Data System (ADS)

Qixing, Chen; Qiyu, Luo

2013-03-01

At present, the architecture of a digital-to-analog converter (DAC) in essence is based on the weight current, and the average value of its D/A signal current increases in geometric series according to its digital signal bits increase, which is 2n-1 times of its least weight current. But for a dual weight resistance chain type DAC, by using the weight voltage manner to D/A conversion, the D/A signal current is fixed to chain current Icha; it is only 1/2n-1 order of magnitude of the average signal current value of the weight current type DAC. Its principle is: n pairs dual weight resistances form a resistance chain, which ensures the constancy of the chain current; if digital signals control the total weight resistance from the output point to the zero potential point, that could directly control the total weight voltage of the output point, so that the digital signals directly turn into a sum of the weight voltage signals; thus the following goals are realized: (1) the total current is less than 200 μA (2) the total power consumption is less than 2 mW; (3) an 18-bit conversion can be realized by adopting a multi-grade structure; (4) the chip area is one order of magnitude smaller than the subsection current-steering type DAC; (5) the error depends only on the error of the unit resistance, so it is smaller than the error of the subsection current-steering type DAC; (6) the conversion time is only one action time of switch on or off, so its speed is not lower than the present DAC.

Simultaneously measured signals in scanning probe microscopy with a needle sensor: frequency shift and tunneling current.

PubMed

Morawski, Ireneusz; Voigtländer, Bert

2010-03-01

We present combined noncontact scanning force microscopy and tunneling current images of a platinum(111) surface obtained by means of a 1 MHz quartz needle sensor. The low-frequency circuit of the tunneling current was combined with a high-frequency signal of the quartz resonator enabling full electrical operation of the sensor. The frequency shift and the tunneling current were detected simultaneously, while the feedback control loop of the topography signal was fed using one of them. In both cases, the free signal that was not connected to the feedback loop reveals proportional-integral controller errorlike behavior, which is governed by the time derivative of the topography signal. A procedure is proposed for determining the mechanical oscillation amplitude by utilizing the tunneling current also including the average tip-sample work function.

Motion control of the rabbit ankle joint with a flat interface nerve electrode.

PubMed

Park, Hyun-Joo; Durand, Dominique M

2015-12-01

A flat interface nerve electrode (FINE) has been shown to improve fascicular and subfascicular selectivity. A recently developed novel control algorithm for FINE was applied to motion control of the rabbit ankle. A 14-contact FINE was placed on the rabbit sciatic nerve (n = 8), and ankle joint motion was controlled for sinusoidal trajectories and filtered random trajectories. To this end, a real-time controller was implemented with a multiple-channel current stimulus isolator. The performance test results showed good tracking performance of rabbit ankle joint motion for filtered random trajectories and sinusoidal trajectories (0.5 Hz and 1.0 Hz) with <10% average root-mean-square (RMS) tracking error, whereas the average range of ankle joint motion was between -20.0 ± 9.3° and 18.1 ± 8.8°. The proposed control algorithm enables the use of a multiple-contact nerve electrode for motion trajectory tracking control of musculoskeletal systems. © 2015 Wiley Periodicals, Inc.

Controlling hollow relativistic electron beam orbits with an inductive current divider

DOE PAGES

Swanekamp, S. B.; Richardson, A. S.; Angus, J. R.; ...

2015-02-06

A passive method for controlling the trajectory of an intense, hollow electron beam is proposed using a vacuum structure that inductively splits the beam's return current. A central post carries a portion of the return current (I 1), while the outer conductor carries the remainder (I 2). An envelope equation appropriate for a hollow electron beam is derived and applied to the current divider. The force on the beam trajectory is shown to be proportional to (I 2-I 1), while the average force on the envelope (the beam width) is proportional to the beam current I b = (I 2more » + I 1). The values of I 1 and I 2 depend on the inductances in the return-current path geometries. Proper choice of the return-current geometries determines these inductances and offers control over the beam trajectory. As a result, solutions using realistic beam parameters show that, for appropriate choices of the return-current-path geometry, the inductive current divider can produce a beam that is both pinched and straightened so that it approaches a target at near-normal incidence with a beam diameter that is on the order of a few mm.« less

Hierarchical Fuzzy Control Applied to Parallel Connected UPS Inverters Using Average Current Sharing Scheme

NASA Astrophysics Data System (ADS)

Singh, Santosh Kumar; Ghatak Choudhuri, Sumit

2018-05-01

Parallel connection of UPS inverters to enhance power rating is a widely accepted practice. Inter-modular circulating currents appear when multiple inverter modules are connected in parallel to supply variable critical load. Interfacing of modules henceforth requires an intensive design, using proper control strategy. The potentiality of human intuitive Fuzzy Logic (FL) control with imprecise system model is well known and thus can be utilised in parallel-connected UPS systems. Conventional FL controller is computational intensive, especially with higher number of input variables. This paper proposes application of Hierarchical-Fuzzy Logic control for parallel connected Multi-modular inverters system for reduced computational burden on the processor for a given switching frequency. Simulated results in MATLAB environment and experimental verification using Texas TMS320F2812 DSP are included to demonstrate feasibility of the proposed control scheme.

Preserved, deteriorated, and premorbidly impaired patterns of intellectual ability in schizophrenia.

PubMed

Ammari, Narmeen; Heinrichs, R Walter; Pinnock, Farena; Miles, Ashley A; Muharib, Eva; McDermid Vaz, Stephanie

2014-05-01

The main purpose of this investigation was to identify patterns of intellectual performance in schizophrenia patients suggesting preserved, deteriorated, and premorbidly impaired ability, and to determine clinical, cognitive, and functional correlates of these patterns. We assessed 101 patients with schizophrenia or schizoaffective disorder and 80 non-psychiatric control participants. The "preserved" performance pattern was defined by average-range estimated premorbid and current IQ with no evidence of decline (premorbid-current IQ difference <10 points). The "deteriorated" pattern was defined by a difference between estimated premorbid and current IQ estimates of 10 points or more. The premorbidly "impaired" pattern was defined by below average estimated premorbid and current IQ and no evidence of decline greater than 10 points. Preserved and deteriorated patterns in healthy controls were also identified and studied in comparison to patient findings. The groups were compared on demographic, neurocognitive, clinical and functionality variables. Patients with the preserved pattern outperformed those meeting criteria for deteriorated and compromised intellectual ability on a composite measure of neurocognitive ability as well as in terms of functional competence. Patients demonstrating the deteriorated and compromised patterns were equivalent across all measures. However, "preserved" patients failed to show any advantage in terms of community functioning and demonstrated cognitive impairments relative to control participants. Our results suggest that proposed patterns of intellectual decline and stability exist in both the schizophrenia and general populations, but may not hold true across other cognitive abilities and do not translate into differential functional outcome.

Characterization of quantum interference control of injected currents in LT-GaAs for carrier-envelope phase measurements.

PubMed

Roos, Peter; Quraishi, Qudsia; Cundiff, Steven; Bhat, Ravi; Sipe, J

2003-08-25

We use two mutually coherent, harmonically related pulse trains to experimentally characterize quantum interference control (QIC) of injected currents in low-temperature-grown gallium arsenide. We observe real-time QIC interference fringes, optimize the QIC signal fidelity, uncover critical signal dependences regarding beam spatial position on the sample, measure signal dependences on the fundamental and second harmonic average optical powers, and demonstrate signal characteristics that depend on the focused beam spot sizes. Following directly from our motivation for this study, we propose an initial experiment to measure and ultimately control the carrier-envelope phase evolution of a single octave-spanning pulse train using the QIC phenomenon.

Allethrin-Based Mosquito Control Device Causing Knockdown, Morbidity, and Mortality in Four Species of Field-Caught Mosquitoes (Diptera: Culicidae).

PubMed

Bibbs, Christopher S; Fulcher, Ali; Xue, Rui-De

2015-07-01

A mosquito control device marketed for spatial repellency, the ThermaCELL Mosquito Repellent Appliance, was evaluated in semifield trials against multiple field-caught species of mosquito. Using paper and mesh cages, mosquito test groups of at least 30 mosquitoes were suspended in a 2,337 cubic foot outdoor space while two ThermaCELL repellent devices were active. After 30 min of treatment, cages were moved to the laboratory to observe knockdown, morbidity, and mortality for 24 h. Species tested included Aedes atlanticus Dyar and Knab (98% average mortality), Psorophora ferox Humboldt (97% average mortality), Psorophora columbiae Dyar and Knab (96% average mortality), and Aedes taeniorhynchus Wiedemann (84% average mortality). The repellent devices showed effectiveness with high knockdown and mortality across all species tested. Mosquito control devices like the ThermaCELL Mosquito Repellent Appliance may have further practical applications to help combat viral exposures by limiting host mosquitoes. Such devices may provide a functional alternative to DEET dependence in the current state of mosquito management. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The effect of education type on common misconceptions of traumatic brain injury.

PubMed

De Iorio, Monica L; Nolan, Susan A; Teague, Susan

2017-11-01

In the current study, we investigated the effects of existing education materials-either a Traumatic Brain Injury (TBI) factsheet or personal stories of people with TBI-on undergraduate students' misconceptions and attributions about the causes of TBI-related behavior. Undergraduate students (N = 164) were recruited through the university participant pool. The participants were randomly assigned to receive either a factsheet about TBI, personal stories of people with TBI, or a control reading. Groups were compared on the number of TBI misconceptions endorsed, scores on an attribution measure, and their willingness to interact with people who have TBIs. Both the TBI factsheet group and the personal stories group endorsed fewer misconceptions, on average, than the control group (p = .02). Additionally, those who read either the personal stories or the factsheet had significantly lower attribution scores, on average, than the control group (p = .001; p = .03). That is, those who read either of the educational materials were more likely to endorse a TBI explanation over an adolescent explanation, compared to those who read a control reading. The groups did not significantly differ on their willingness for social interaction. Results suggest that, on average, factsheets and personal stories are effective for increasing knowledge about moderate-to-severe TBI as compared to a control group. Personal stories and factsheets may also be useful, on average, for addressing tendencies to discount TBIs as explanations for behavioral change, as compared to a control group. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Controlled manipulation and actuation of micro-objects with magnetotactic bacteria

NASA Astrophysics Data System (ADS)

Martel, Sylvain; Tremblay, Charles C.; Ngakeng, Serge; Langlois, Guillaume

2006-12-01

Bacterial actuation and manipulation are demonstrated where Magnetospirillum gryphiswaldense magnetotactic bacteria (MTB) are used to push 3μm beads at an average velocity of 7.5μms-1 along preplanned paths by modifying the torque on a chain of magnetosomes in the bacterium with a directional magnetic field of at least 0.5G generated from a small programmed electrical current. But measured average thrusts of 0.5 and 4pN of the flagellar motor of a single Magnetospirillum gryphiswaldense and MC-1 MTB suggest that average velocities greater than 16 and 128μms-1, respectively could be achieved.

Ultrafast Spectroscopy of Chromophores

DTIC Science & Technology

2012-01-31

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES... 1

The relationship between heavy metal and rap music and adolescent turmoil: real or artifact?

PubMed

Took, K J; Weiss, D S

1994-01-01

Adolescents and their parents were surveyed to investigate the association between heavy metal and rap music and adolescent psychosocial turmoil. Subjects were asked about current and past psychosocial functioning, as well as their music preferences. Adolescents who preferred heavy metal and rap music were compared with those who preferred other types of music. Results indicated that adolescents who preferred heavy metal and rap had a higher incidence of below-average school grades, school behavior problems, sexual activity, drug and alcohol use, and arrests. However, when gender was controlled, only below-average current and elementary school grades and a history of counseling in elementary school for school problems remained significant. Implications of these findings are discussed.

Dynamical investigation and parameter stability region analysis of a flywheel energy storage system in charging mode

NASA Astrophysics Data System (ADS)

Zhang, Wei-Ya; Li, Yong-Li; Chang, Xiao-Yong; Wang, Nan

2013-09-01

In this paper, the dynamic behavior analysis of the electromechanical coupling characteristics of a flywheel energy storage system (FESS) with a permanent magnet (PM) brushless direct-current (DC) motor (BLDCM) is studied. The Hopf bifurcation theory and nonlinear methods are used to investigate the generation process and mechanism of the coupled dynamic behavior for the average current controlled FESS in the charging mode. First, the universal nonlinear dynamic model of the FESS based on the BLDCM is derived. Then, for a 0.01 kWh/1.6 kW FESS platform in the Key Laboratory of the Smart Grid at Tianjin University, the phase trajectory of the FESS from a stable state towards chaos is presented using numerical and stroboscopic methods, and all dynamic behaviors of the system in this process are captured. The characteristics of the low-frequency oscillation and the mechanism of the Hopf bifurcation are investigated based on the Routh stability criterion and nonlinear dynamic theory. It is shown that the Hopf bifurcation is directly due to the loss of control over the inductor current, which is caused by the system control parameters exceeding certain ranges. This coupling nonlinear process of the FESS affects the stability of the motor running and the efficiency of energy transfer. In this paper, we investigate into the effects of control parameter change on the stability and the stability regions of these parameters based on the averaged-model approach. Furthermore, the effect of the quantization error in the digital control system is considered to modify the stability regions of the control parameters. Finally, these theoretical results are verified through platform experiments.

Octanol reduces end-plate channel lifetime

PubMed Central

Gage, Peter W.; McBurney, Robert N.; Van Helden, Dirk

1978-01-01

1. Post-synaptic effects of n-octanol at concentrations of 0·1-1 mM were examined in toad sartorius muscles by use of extracellular and voltage-clamp techniques. 2. Octanol depressed the amplitude and duration of miniature end-plate currents and hence depressed neuromuscular transmission. 3. The decay of miniature end-plate currents remained exponential in octanol solutions even when the time constant of decay (τD) was decreased by 80-90%. 4. The lifetime of end-plate channels, obtained by analysis of acetylcholine noise, was also decreased by octanol. The average lifetime measured from noise spectra agreed reasonably well with the time constant of decay of miniature end-plate currents, both in control solution and in octanol solutions. 5. Octanol caused a reduction in the conductance of end-plate channels. Single channel conductance was on average about 25 pS in control solution and 20 pS in octanol. 6. In most cells the normal voltage sensitivity of the decay of miniature end-plate currents was retained in octanol solutions. The lifetime of end-plate channels measured from acetylcholine noise also remained voltage-sensitive in octanol solutions. In some experiments in which channel lifetime was exceptionally reduced the voltage sensitivity was less than normal. 7. In octanol solutions, τD was still very sensitive to temperature changes in most cells although in some the temperature sensitivity of τD was clearly reduced. Changes in τD with temperature could generally be fitted by the Arrhenius equation suggesting that a single step reaction controlled the decay of currents both in control and in octanol solutions. In some cells in which τD became less than 0·3 ms, the relationship between τD and temperature became inconsistent with the Arrhenius equation. 8. As the decay of end-plate currents in octanol solutions remains exponential, and the voltage and temperature sensitivity can be unchanged even when τD is significantly reduced, it seems likely that octanol decreases τD by increasing the rate of the reaction which normally controls the lifetime of end-plate channels. PMID:203674

Transition Control with Dielectric Barrier Discharge Plasmas

DTIC Science & Technology

2013-01-01

release; distribution is unlimited. of transition is observed . For higher applied body forces, the transition delay effect is enhanced, but care has...REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 3 January 2013 2. REPORT TYPE

In Silico Testing of an Artificial-Intelligence-Based Artificial Pancreas Designed for Use in the Intensive Care Unit Setting

PubMed Central

DeJournett, Leon; DeJournett, Jeremy

2016-01-01

Background: Effective glucose control in the intensive care unit (ICU) setting has the potential to decrease morbidity and mortality rates which should in turn lead to decreased health care expenditures. Current ICU-based glucose controllers are mathematically derived, and tend to be based on proportional integral derivative (PID) or model predictive control (MPC). Artificial intelligence (AI)–based closed loop glucose controllers may have the ability to achieve control that improves on the results achieved by either PID or MPC controllers. Method: We conducted an in silico analysis of an AI-based glucose controller designed for use in the ICU setting. This controller was tested using a mathematical model of the ICU patient’s glucose-insulin system. A total of 126 000 unique 5-day simulations were carried out, resulting in 107 million glucose values for analysis. Results: For the 7 control ranges tested, with a sensor error of ±10%, the following average results were achieved: (1) time in control range, 94.2%, (2) time in range 70-140 mg/dl, 97.8%, (3) time in hyperglycemic range (>140 mg/dl), 2.1%, and (4) time in hypoglycemic range (<70 mg/dl), 0.09%. In addition, the average coefficient of variation (CV) was 11.1%. Conclusions: This in silico study of an AI-based closed loop glucose controller shows that it may be able to improve on the results achieved by currently existing ICU-based PID/MPC controllers. If these results are confirmed in clinical testing, this AI-based controller could be used to create an artificial pancreas system for use in the ICU setting. PMID:27301982

In Silico Testing of an Artificial-Intelligence-Based Artificial Pancreas Designed for Use in the Intensive Care Unit Setting.

PubMed

DeJournett, Leon; DeJournett, Jeremy

2016-11-01

Effective glucose control in the intensive care unit (ICU) setting has the potential to decrease morbidity and mortality rates which should in turn lead to decreased health care expenditures. Current ICU-based glucose controllers are mathematically derived, and tend to be based on proportional integral derivative (PID) or model predictive control (MPC). Artificial intelligence (AI)-based closed loop glucose controllers may have the ability to achieve control that improves on the results achieved by either PID or MPC controllers. We conducted an in silico analysis of an AI-based glucose controller designed for use in the ICU setting. This controller was tested using a mathematical model of the ICU patient's glucose-insulin system. A total of 126 000 unique 5-day simulations were carried out, resulting in 107 million glucose values for analysis. For the 7 control ranges tested, with a sensor error of ±10%, the following average results were achieved: (1) time in control range, 94.2%, (2) time in range 70-140 mg/dl, 97.8%, (3) time in hyperglycemic range (>140 mg/dl), 2.1%, and (4) time in hypoglycemic range (<70 mg/dl), 0.09%. In addition, the average coefficient of variation (CV) was 11.1%. This in silico study of an AI-based closed loop glucose controller shows that it may be able to improve on the results achieved by currently existing ICU-based PID/MPC controllers. If these results are confirmed in clinical testing, this AI-based controller could be used to create an artificial pancreas system for use in the ICU setting. © 2016 Diabetes Technology Society.

Kinect technology for hand tracking control of surgical robots: technical and surgical skill comparison to current robotic masters.

PubMed

Kim, Yonjae; Leonard, Simon; Shademan, Azad; Krieger, Axel; Kim, Peter C W

2014-06-01

Current surgical robots are controlled by a mechanical master located away from the patient, tracking surgeon's hands by wire and pulleys or mechanical linkage. Contactless hand tracking for surgical robot control is an attractive alternative, because it can be executed with minimal footprint at the patient's bedside without impairing sterility, while eliminating current disassociation between surgeon and patient. We compared technical and technologic feasibility of contactless hand tracking to the current clinical standard master controllers. A hand-tracking system (Kinect™-based 3Gear), a wire-based mechanical master (Mantis Duo), and a clinical mechanical linkage master (da Vinci) were evaluated for technical parameters with strong clinical relevance: system latency, static noise, robot slave tremor, and controller range. Five experienced surgeons performed a skill comparison study, evaluating the three different master controllers for efficiency and accuracy in peg transfer and pointing tasks. da Vinci had the lowest latency of 89 ms, followed by Mantis with 374 ms and 3Gear with 576 ms. Mantis and da Vinci produced zero static error. 3Gear produced average static error of 0.49 mm. The tremor of the robot used by the 3Gear and Mantis system had a radius of 1.7 mm compared with 0.5 mm for da Vinci. The three master controllers all had similar range. The surgeons took 1.98 times longer to complete the peg transfer task with the 3Gear system compared with Mantis, and 2.72 times longer with Mantis compared with da Vinci (p value 2.1e-9). For the pointer task, surgeons were most accurate with da Vinci with average error of 0.72 mm compared with Mantis's 1.61 mm and 3Gear's 2.41 mm (p value 0.00078). Contactless hand-tracking technology as a surgical master can execute simple surgical tasks. Whereas traditional master controllers outperformed, given that contactless hand-tracking is a first-generation technology, clinical potential is promising and could become a reality with some technical improvements.

Continuously Available Battlefield Surveillance

DTIC Science & Technology

2007-04-01

the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data...display a currently valid OMB control number. 1 . REPORT DATE APR 2007 2. REPORT TYPE 3. DATES COVERED 00-00-2007 to 00-00-2007 4. TITLE AND... 1 The Thesis of this Report

Fiber Optic Biosensors for Contaminant Monitoring

DTIC Science & Technology

2005-12-01

collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources...currently valid OMB control number 1 . REPORT DATE DEC 2005 2. REPORT TYPE 3. DATES COVERED 00-00-2005 to 00-00-2005 4. TITLE AND SUBTITLE... 1 Executive Summary

Bi-axial Vibration Energy Harvesting

DTIC Science & Technology

2012-07-01

included early dedicated portable signal averaging equipment, Nomad, CT4 and F18 fatigue test control systems and some field trials. Currently he is...and repairs to acoustically- fatigued structures. ____________________ ________________________________________________ UNCLASSIFIED...Physicists at the Tokyo Institute of Technology investigated various piezoceramic materials [20], developing lead zirconate titanate ( PZT ) in around 1952

Controlling hollow relativistic electron beam orbits with an inductive current divider

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

Swanekamp, S. B.; Richardson, A. S.; Angus, J. R.

2015-02-15

A passive method for controlling the trajectory of an intense, hollow electron beam is proposed using a vacuum structure that inductively splits the beam's return current. A central post carries a portion of the return current (I{sub 1}), while the outer conductor carries the remainder (I{sub 2}). An envelope equation appropriate for a hollow electron beam is derived and applied to the current divider. The force on the beam trajectory is shown to be proportional to (I{sub 2}-I{sub 1}), while the average force on the envelope (the beam width) is proportional to the beam current I{sub b} = (I{sub 2} + I{sub 1}). Themore » values of I{sub 1} and I{sub 2} depend on the inductances in the return-current path geometries. Proper choice of the return-current geometries determines these inductances and offers control over the beam trajectory. Solutions using realistic beam parameters show that, for appropriate choices of the return-current-path geometry, the inductive current divider can produce a beam that is both pinched and straightened so that it approaches a target at near-normal incidence with a beam diameter that is on the order of a few mm.« less

Analysis and Design of Bridgeless Switched Mode Power Supply for Computers

NASA Astrophysics Data System (ADS)

Singh, S.; Bhuvaneswari, G.; Singh, B.

2014-09-01

Switched mode power supplies (SMPSs) used in computers need multiple isolated and stiffly regulated output dc voltages with different current ratings. These isolated multiple output dc voltages are obtained by using a multi-winding high frequency transformer (HFT). A half-bridge dc-dc converter is used here for obtaining different isolated and well regulated dc voltages. In the front end, non-isolated Single Ended Primary Inductance Converters (SEPICs) are added to improve the power quality in terms of low input current harmonics and high power factor (PF). Two non-isolated SEPICs are connected in a way to completely eliminate the need of single-phase diode-bridge rectifier at the front end. Output dc voltages at both the non-isolated and isolated stages are controlled and regulated separately for power quality improvement. A voltage mode control approach is used in the non-isolated SEPIC stage for simple and effective control whereas average current control is used in the second isolated stage.

Bioaugmentation for Remediation of Chlorinated Solvents: Technology Development, Status, and Research Needs

DTIC Science & Technology

2005-10-01

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE...staff at GeoSyntec, though other vendors and experts have contributed as well. The objectives of this White Paper are to: 1 ) summarize the current

Shock Boundary Layer Interaction Flow Control with Micro Vortex Generators

DTIC Science & Technology

2011-05-01

Pitot rake ( p̄02p01 ) u = time-averaged streamwise velocity ufs = time-averaged freestream streamwise velocity u∗ = √ τw ρw = wall-shear velocity w...upstream of the normal shock-wave 2 = station 2, at the Pitot rake location I. Introduction With the exception of the scramjet, all current air-breathing...to this.7 1 shock holder near-normal shock μVGs 123 143 14 hole Pitot rake 6o x vg variable φ cylinder mounted on the centre-line 380 M ∞ =1.4

A numerical study of the acoustic radiation due to eddy current-cryostat interactions.

PubMed

Wang, Yaohui; Liu, Feng; Zhou, Xiaorong; Li, Yu; Crozier, Stuart

2017-06-01

To investigate the acoustic radiation due to eddy current-cryostat interactions and perform a qualitative analysis on noise reduction methods. In order to evaluate the sound pressure level (SPL) of the eddy current induced warm bore wall vibration, a Finite Element (FE) model was created to simulate the noises from both the warm bore wall vibration and the gradient coil assembly. For the SPL reduction of the warm bore wall vibration, we first improved the active shielding of the gradient coil, thus reducing the eddy current on the warm bore wall. A damping treatment was then applied to the warm bore wall to control the acoustic radiation. Initial simulations show that the SPL of the warm bore wall is higher than that of the gradient assembly with typical design shielding ratios at many frequencies. Subsequent simulation results of eddy current control and damping treatment application show that the average SPL reduction of the warm bore wall can be as high as 9.6 dB, and even higher in some frequency bands. Combining eddy current control and suggested damping scheme, the noise level in a MRI system can be effectively reduced. © 2017 American Association of Physicists in Medicine.

Average current is better than peak current as therapeutic dosage for biphasic waveforms in a ventricular fibrillation pig model of cardiac arrest.

PubMed

Chen, Bihua; Yu, Tao; Ristagno, Giuseppe; Quan, Weilun; Li, Yongqin

2014-10-01

Defibrillation current has been shown to be a clinically more relevant dosing unit than energy. However, the effects of average and peak current in determining shock outcome are still undetermined. The aim of this study was to investigate the relationship between average current, peak current and defibrillation success when different biphasic waveforms were employed. Ventricular fibrillation (VF) was electrically induced in 22 domestic male pigs. Animals were then randomized to receive defibrillation using one of two different biphasic waveforms. A grouped up-and-down defibrillation threshold-testing protocol was used to maintain the average success rate of 50% in the neighborhood. In 14 animals (Study A), defibrillations were accomplished with either biphasic truncated exponential (BTE) or rectilinear biphasic waveforms. In eight animals (Study B), shocks were delivered using two BTE waveforms that had identical peak current but different waveform durations. Both average and peak currents were associated with defibrillation success when BTE and rectilinear waveforms were investigated. However, when pathway impedance was less than 90Ω for the BTE waveform, bivariate correlation coefficient was 0.36 (p=0.001) for the average current, but only 0.21 (p=0.06) for the peak current in Study A. In Study B, a high defibrillation success (67.9% vs. 38.8%, p<0.001) was observed when the waveform delivered more average current (14.9±2.1A vs. 13.5±1.7A, p<0.001) while keeping the peak current unchanged. In this porcine model of VF, average current was better than peak current to be an adequate parameter to describe the therapeutic dosage when biphasic defibrillation waveforms were used. The institutional protocol number: P0805. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Estimating the confidence bounds for projected ozone design values under different emissions control options

EPA Science Inventory

In current regulatory applications, regional air quality model is applied for a base year and a future year with reduced emissions using the same meteorological conditions. The base year design value is multiplied by the ratio of the average of the top 10 ozone concentrations fo...

78 FR 47479 - 30-Day Notice of Proposed Information Collection: Nonimmigrant Treaty Trader/Investor Application

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-05

...: Nonimmigrant Treaty Trader/Investor Application ACTION: Notice of request for public comment and submission to.../Investor Application OMB Control Number: OMB-1405-0101 Type of Request: Extension of a Currently Approved... Investor Estimated Number of Respondents: 41,752 Estimated Number of Responses: 41,752 Average Time per...

Exuberant and Inhibited Children: Person-Centered Profiles and Links to Social Adjustment

ERIC Educational Resources Information Center

Dollar, Jessica M.; Stifter, Cynthia A.; Buss, Kristin A.

2017-01-01

The current study aimed to substantiate and extend our understanding regarding the existence and developmental pathways of 3 distinct temperament profiles--exuberant, inhibited, and average approach--in a sample of 3.5-year-old children (n = 121). The interactions between temperamental styles and specific types of effortful control, inhibitory…

Classroom Utilization. AIR 1986 Annual Forum Paper.

ERIC Educational Resources Information Center

Gracie, Larry W.

The use of an index to match classes and classroom space was assessed. The index initiates the use of several variables controlling utilization: number of hours that rooms are scheduled per week, average percentage of occupancy per room, and amount of area per station per room. Interviews with deans covered current classroom assignment…

Real-time control system for adaptive resonator

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

Flath, L; An, J; Brase, J

2000-07-24

Sustained operation of high average power solid-state lasers currently requires an adaptive resonator to produce the optimal beam quality. We describe the architecture of a real-time adaptive control system for correcting intra-cavity aberrations in a heat capacity laser. Image data collected from a wavefront sensor are processed and used to control phase with a high-spatial-resolution deformable mirror. Our controller takes advantage of recent developments in low-cost, high-performance processor technology. A desktop-based computational engine and object-oriented software architecture replaces the high-cost rack-mount embedded computers of previous systems.

A Dihydropyridine-sensitive Voltage-dependent Calcium Channel in the Sarcolemmal Membrane of Crustacean Muscle

PubMed Central

Erxleben, Christian; Rathmayer, Werner

1997-01-01

Single-channel currents through calcium channels in muscle of a marine crustacean, the isopod Idotea baltica, were investigated in cell-attached patches. Inward barium currents were strongly voltage-dependent, and the channels were closed at the cell's resting membrane potential. The open probability (Po) increased e-fold for an 8.2 mV (±2.4, n = 13) depolarization. Channel openings were mainly brief (<0.3 ms) and evenly distributed throughout 100-ms pulses. Averaged, quasimacroscopic currents showed fast activation and deactivation and did not inactivate during 100-ms test pulses. Similarly, channel activity persisted at steadily depolarized holding potentials. With 200 mM Ba2+ as charge carrier, the average slope conductance from the unitary currents between +30 and +80 mV, was 20 pS (±2.6, n = 12). The proportion of long openings, which were very infrequent under control conditions, was greatly increased by preincubation of the muscle fibers with the calcium channel agonist, the dihydropyridine Bay K8644 (10–100 μM). Properties of these currents resemble those through the L-type calcium channels of mammalian nerve, smooth muscle, and cardiac muscle cells. PMID:9089439

An inverse problem of determining the implied volatility in option pricing

NASA Astrophysics Data System (ADS)

Deng, Zui-Cha; Yu, Jian-Ning; Yang, Liu

2008-04-01

In the Black-Scholes world there is the important quantity of volatility which cannot be observed directly but has a major impact on the option value. In practice, traders usually work with what is known as implied volatility which is implied by option prices observed in the market. In this paper, we use an optimal control framework to discuss an inverse problem of determining the implied volatility when the average option premium, namely the average value of option premium corresponding with a fixed strike price and all possible maturities from the current time to a chosen future time, is known. The issue is converted into a terminal control problem by Green function method. The existence and uniqueness of the minimum of the control functional are addressed by the optimal control method, and the necessary condition which must be satisfied by the minimum is also given. The results obtained in the paper may be useful for those who engage in risk management or volatility trading.

Carbon Stripper Foils Used in the Los Alamos PSR

NASA Astrophysics Data System (ADS)

Borden, M.; Plum, M. A.; Sugai, I.

1997-05-01

Carbon stripper foils produced by the modified controlled ACDC arc discharge method (mCADAD) at the Institute for Nuclear Study by Dr. Isao Sugai have been tested and used for high current 800-MeV beam production in the Proton Storage Ring (PSR) since 1993. Two approximately 110 μg/cm2 foils are sandwiched together to produce an equivalent 220 μg/cm^2 foil. The combined foil is supported by 4-5 μm diameter carbon fibers attached to an aluminum frame. These foils have survived as long as five months during PSR normal beam production of near 70 μA on target average current. Typical life-times of other foils vary from seven to fourteen days with lower on-target average current. Beam loss data also indicate that Sugai's foils have slower shrinkage rates than other foils. Equipment has been assembled and used to produce foils by the mCADAD method at Los Alamos. These foils will be tested during 1997 operation.

Thermocathode radio-frequency gun for the Budker Institute of Nuclear Physics free-electron laser

NASA Astrophysics Data System (ADS)

Volkov, V.; Getmanov, Ya.; Kenjebulatov, E.; Kolobanov, E.; Krutikhin, S.; Kurkin, G.; Ovchar, V.; Petrov, V. M.; Sedlyarov, I.

2016-12-01

A radio-frequency (RF) gun for a race-track microtron-recuperator injector driving the free-electron laser (FEL) (Budker Institute of Nuclear Physics) is being tested at a special stand. Electron bunches of the RF gun have an energy of up to 300 keV and a repetition rate of up to 90 MHz. The average electro-beam current can reach 100 mA in the continuous operation regime. The advantages of the new injector are as follows: long lifetime of the cathode for high average beam current; simple scheme of longitudinal beam bunching, which does not require an additional bunching resonator in the injector; absence of dark-current contamination of the injector beam; and comfortable RF gun operation due to the absence of a high potential of 300 kV at the cathode control circuits. In this study we describe the RF gun design, present the main characteristics of the injector with the RF gun, and give the results of testing.

Flyback CCM inverter for AC module applications: iterative learning control and convergence analysis

NASA Astrophysics Data System (ADS)

Lee, Sung-Ho; Kim, Minsung

2017-12-01

This paper presents an iterative learning controller (ILC) for an interleaved flyback inverter operating in continuous conduction mode (CCM). The flyback CCM inverter features small output ripple current, high efficiency, and low cost, and hence it is well suited for photovoltaic power applications. However, it exhibits the non-minimum phase behaviour, because its transfer function from control duty to output current has the right-half-plane (RHP) zero. Moreover, the flyback CCM inverter suffers from the time-varying grid voltage disturbance. Thus, conventional control scheme results in inaccurate output tracking. To overcome these problems, the ILC is first developed and applied to the flyback inverter operating in CCM. The ILC makes use of both predictive and current learning terms which help the system output to converge to the reference trajectory. We take into account the nonlinear averaged model and use it to construct the proposed controller. It is proven that the system output globally converges to the reference trajectory in the absence of state disturbances, output noises, or initial state errors. Numerical simulations are performed to validate the proposed control scheme, and experiments using 400-W AC module prototype are carried out to demonstrate its practical feasibility.

Processes controlling the remobilization of surficial sediment and formation of sedimentary furrows in north-central Long Island Sound

USGS Publications Warehouse

Poppe, L.J.; Knebel, H.J.; Lewis, R.S.; DiGiacomo-Cohen, M. L.

2002-01-01

Sidescan sonar, bathymetric, subbottom, and bottom-photographic surveys and sediment sampling have improved our understanding of the processes that control the complex distribution of bottom sediments and benthic habitats in Long Island Sound. Although the deeper (>20 m) waters of the central Sound are long-term depositional areas characterized by relatively weak bottom-current regimes, our data reveal the localized presence of sedimentary furrows. These erosional bedforms occur in fine-grained cohesive sediments (silts and clayey silts), trend east-northeast, are irregularly spaced, and have indistinct troughs with gently sloping walls. The average width and relief of the furrows is 9.2 m and 0.4 m, respectively. The furrows average about 206 m long, but range in length from 30 m to over 1,300 m. Longitudinal ripples, bioturbation, and nutclam shell debris are common within the furrows. Although many of the furrows appear to end by gradually narrowing, some furrows show a "tuning fork" joining pattern. Most of these junctions open toward the east, indicating net westward sediment transport. However, a few junctions open toward the west suggesting that oscillating tidal currents are the dominant mechanism controlling furrow formation. Sedimentary furrows and longitudinal ripples typically form in environments which have recurring, directionally stable, and occasionally strong currents. The elongate geometry and regional bathymetry of Long Island Sound combine to constrain the dominant tidal and storm currents to east-west flow directions and permit the development of these bedforms. Through resuspension due to biological activity and the subsequent development of erosional bedforms, fine-grained cohesive sediment can be remobilized and made available for transport farther westward into the estuary.

Processes controlling the remobilization of surficial sediment and formation of sedimentary furrows in North-Central Long Island Sound

USGS Publications Warehouse

Poppe, L.J.; Knebel, H.J.; Lewis, R.S.; DiGiacomo-Cohen, M. L.

2002-01-01

Sidescan sonar, bathymetric, subbottom, and bottom-photographic surveys and sediment sampling have improved our understanding of the processes that control the complex distribution of bottom sediments and benthic habitats in Long Island Sound. Although the deeper (>20 m) waters of the central Sound are long-term depositional areas characterized by relatively weak bottom-current regimes, our data reveal the localized presence of sedimentary furrows. These erosional bedforms occur in fine-grained cohesive sediments (silts and clayey silts), trend east-northeast, are irregularly spaced, and have indistinct troughs with gently sloping walls. The average width and relief of the furrows is 9.2 m and 0.4 m, respectively. The furrows average about 206 m long, but range in length from 30 m to over 1,300 m. Longitudinal ripples, bioturbation, and nutclam shell debris are common within the furrows. Although many of the furrows appear to end by gradually narrowing, some furrows show a "tuning fork" joining pattern. Most of these junctions open toward the east, indicating net westward sediment transport. However, a few junctions open toward the west suggesting that oscillating tidal currents are the dominant mechanism controlling furrow formation. Sedimentary furrows and longitudinal ripples typically form in environments which have recurring, directionally stable, and occasionally strong currents. The elongate geometry and regional bathymetry of Long Island Sound combine to constrain the dominant tidal and storm currents to east-west flow directions and permit the development of these bedforms. Through resuspension due to biological activity and the subsequent development of erosional bedforms, fine-grained cohesive sediment can be remobilized and made available for transport farther westward into the estuary.

Occupational exposure to electric fields and induced currents associated with 400 kV substation tasks from different service platforms.

PubMed

Korpinen, Leena H; Elovaara, Jarmo A; Kuisti, Harri A

2011-01-01

The aim of the study was to investigate the occupational exposure to electric fields, average current densities, and average total contact currents at 400 kV substation tasks from different service platforms (main transformer inspection, maintenance of operating device of disconnector, maintenance of operating device of circuit breaker). The average values are calculated over measured periods (about 2.5 min). In many work tasks, the maximum electric field strengths exceeded the action values proposed in the EU Directive 2004/40/EC, but the average electric fields (0.2-24.5 kV/m) were at least 40% lower than the maximum values. The average current densities were 0.1-2.3 mA/m² and the average total contact currents 2.0-143.2 µA, that is, clearly less than the limit values of the EU Directive. The average values of the currents in head and contact currents were 16-68% lower than the maximum values when we compared the average value from all cases in the same substation. In the future it is important to pay attention to the fact that the action and limit values of the EU Directive differ significantly. It is also important to take into account that generally, the workers' exposure to the electric fields, current densities, and total contact currents are obviously lower if we use the average values from a certain measured time period (e.g., 2.5 min) than in the case where exposure is defined with only the help of the maximum values. © 2010 Wiley-Liss, Inc.

Maximum time-dependent space-charge limited diode currents

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

Griswold, M. E.; Fisch, N. J.

Recent papers claim that a one dimensional (1D) diode with a time-varying voltage drop can transmit current densities that exceed the Child-Langmuir (CL) limit on average, apparently contradicting a previous conjecture that there is a hard limit on the average current density across any 1D diode, as t → ∞, that is equal to the CL limit. However, these claims rest on a different definition of the CL limit, namely, a comparison between the time-averaged diode current and the adiabatic average of the expression for the stationary CL limit. If the current were considered as a function of the maximummore » applied voltage, rather than the average applied voltage, then the original conjecture would not have been refuted.« less

National stereotypes of older people's competence are related to older adults' participation in paid and volunteer work.

PubMed

Bowen, Catherine E; Skirbekk, Vegard

2013-11-01

Why are older people perceived as more competent in some countries relative to others? In the current study, we investigate the extent to which national variation in perceptions of older people's competence is systematically related to national variation in the extent to which older people participate in paid and volunteer work. We used multilevel regression to analyze data from the European Social Survey and test the relationship between perceptions of older people's competence and older people's participation in paid and volunteer work across 28 countries. We controlled for a number of potentially confounding variables, including life expectancy as well as the gender ratio and average education of the older population in each country. We controlled for the average objective cognitive abilities of the older population in a subsample of 11 countries. Older people were perceived as more competent in countries in which more older people participated in paid or volunteer work, independent of life expectancy and the average education, gender makeup, and average cognitive abilities of the older population. The results suggest that older people's participation in paid and volunteer work is related to perceptions of older people's competence independent of older people's actual competence.

The Relationship between Principal Leadership and Teacher Collaboration in Turkish Primary Schools: A Multilevel Analysis

ERIC Educational Resources Information Center

Gumus, Sedat; Bulut, Okan; Bellibas, Mehmet Sukru

2013-01-01

The purpose of the current study is to reveal the relationship between the specific leadership behaviors of principals and teacher collaboration in Turkish primary schools, controlling for several school characteristics, such as school size and average class size, and the demographic characteristics of teachers, such as level of education and…

Sexuality in Adolescent Boys with Autism Spectrum Disorder: Self-Reported Behaviours and Attitudes

ERIC Educational Resources Information Center

Dewinter, Jeroen; Vermeiren, Robert; Vanwesenbeeck, Ine; Lobbestael, Jill; Van Nieuwenhuizen, Chijs

2015-01-01

Differences in sexual functioning of adolescents with and without autism spectrum disorder (ASD) are understudied. In the current study, self-reported sexual behaviours, interests and attitudes of 50 adolescent boys, aged 15-18, with at least average intelligence and diagnosed with ASD, were compared with a matched general population control group…

Module failure isolation circuit for paralleled inverters. [preventing system failure during power conditioning for spacecraft applications

NASA Technical Reports Server (NTRS)

Nagano, S. (Inventor)

1979-01-01

A module failure isolation circuit is described which senses and averages the collector current of each paralled inverter power transistor and compares the collector current of each power transistor the average collector current of all power transistors to determine when the sensed collector current of a power transistor in any one inverter falls below a predetermined ratio of the average collector current. The module associated with any transistor that fails to maintain a current level above the predetermined radio of the average collector current is then shut off. A separate circuit detects when there is no load, or a light load, to inhibit operation of the isolation circuit during no load or light load conditions.

Manual control of unstable systems

NASA Technical Reports Server (NTRS)

Allen, R. W.; Hogue, J. R.; Parseghian, Z.

1986-01-01

Under certain operational regimes and failure modes, air and ground vehicles can present the human operator with a dynamically unstable or divergent control task. Research conducted over the last two decades has explored the ability of the human operator to control unstable systems under a variety of circumstances. Past research is reviewed and human operator control capabilities are summarized. A current example of automobile directional control under rear brake lockup conditions is also reviewed. A control system model analysis of the driver's steering control task is summarized, based on a generic driver/vehicle model presented at last year's Annual Manual. Results from closed course braking tests are presented that confirm the difficulty the average driver has in controlling the unstable directional dynamics arising from rear wheel lockup.

Controlled growth of well-aligned GaS nanohornlike structures and their field emission properties.

PubMed

Sinha, Godhuli; Panda, Subhendu K; Datta, Anuja; Chavan, Padmakar G; Shinde, Deodatta R; More, Mahendra A; Joag, D S; Patra, Amitava

2011-06-01

Here, we report the synthesis of vertically aligned gallium sulfide (GaS) nanohorn arrays using simple vapor-liquid-solid (VLS) method. The morphologies of GaS nano and microstructures are tuned by controlling the temperature and position of the substrate with respect to the source material. A plausible mechanism for the controlled growth has been proposed. It is important to note that the turn-on field value of GaS nanohorns array is found to be the low turn-on field 4.2 V/μm having current density of 0.1 μA/cm(2). The striking feature of the field emission behavior of the GaS nanohorn arrays is that the average emission current remains nearly constant over long time without any degradation. © 2011 American Chemical Society

Nonlinear Recurrent Neural Network Predictive Control for Energy Distribution of a Fuel Cell Powered Robot

PubMed Central

Chen, Qihong; Long, Rong; Quan, Shuhai

2014-01-01

This paper presents a neural network predictive control strategy to optimize power distribution for a fuel cell/ultracapacitor hybrid power system of a robot. We model the nonlinear power system by employing time variant auto-regressive moving average with exogenous (ARMAX), and using recurrent neural network to represent the complicated coefficients of the ARMAX model. Because the dynamic of the system is viewed as operating- state- dependent time varying local linear behavior in this frame, a linear constrained model predictive control algorithm is developed to optimize the power splitting between the fuel cell and ultracapacitor. The proposed algorithm significantly simplifies implementation of the controller and can handle multiple constraints, such as limiting substantial fluctuation of fuel cell current. Experiment and simulation results demonstrate that the control strategy can optimally split power between the fuel cell and ultracapacitor, limit the change rate of the fuel cell current, and so as to extend the lifetime of the fuel cell. PMID:24707206

An omnipotent Li-ion battery charger with multimode control and polarity reversible techniques

NASA Astrophysics Data System (ADS)

Chen, Jiann-Jong; Ku, Yi-Tsen; Yang, Hong-Yi; Hwang, Yuh-Shyan; Yu, Cheng-Chieh

2016-07-01

The omnipotent Li-ion battery charger with multimode control and polarity reversible techniques is presented in this article. The proposed chip is fabricated with TSMC 0.35μm 2P4M complementary metal-oxide- semiconductor processes, and the chip area including pads is 1.5 × 1.5 mm2. The structure of the omnipotent charger combines three charging modes and polarity reversible techniques, which adapt to any Li-ion batteries. The three reversible Li-ion battery charging modes, including trickle-current charging, large-current charging and constant-voltage charging, can charge in matching polarities or opposite polarities. The proposed circuit has a maximum charging current of 300 mA and the input voltage of the proposed circuit is set to 4.5 V. The maximum efficiency of the proposed charger is about 91% and its average efficiency is 74.8%. The omnipotent charger can precisely provide the charging current to the battery.

A brain-controlled lower-limb exoskeleton for human gait training.

PubMed

Liu, Dong; Chen, Weihai; Pei, Zhongcai; Wang, Jianhua

2017-10-01

Brain-computer interfaces have been a novel approach to translate human intentions into movement commands in robotic systems. This paper describes an electroencephalogram-based brain-controlled lower-limb exoskeleton for gait training, as a proof of concept towards rehabilitation with human-in-the-loop. Instead of using conventional single electroencephalography correlates, e.g., evoked P300 or spontaneous motor imagery, we propose a novel framework integrated two asynchronous signal modalities, i.e., sensorimotor rhythms (SMRs) and movement-related cortical potentials (MRCPs). We executed experiments in a biologically inspired and customized lower-limb exoskeleton where subjects (N = 6) actively controlled the robot using their brain signals. Each subject performed three consecutive sessions composed of offline training, online visual feedback testing, and online robot-control recordings. Post hoc evaluations were conducted including mental workload assessment, feature analysis, and statistics test. An average robot-control accuracy of 80.16% ± 5.44% was obtained with the SMR-based method, while estimation using the MRCP-based method yielded an average performance of 68.62% ± 8.55%. The experimental results showed the feasibility of the proposed framework with all subjects successfully controlled the exoskeleton. The current paradigm could be further extended to paraplegic patients in clinical trials.

A brain-controlled lower-limb exoskeleton for human gait training

NASA Astrophysics Data System (ADS)

Liu, Dong; Chen, Weihai; Pei, Zhongcai; Wang, Jianhua

2017-10-01

Brain-computer interfaces have been a novel approach to translate human intentions into movement commands in robotic systems. This paper describes an electroencephalogram-based brain-controlled lower-limb exoskeleton for gait training, as a proof of concept towards rehabilitation with human-in-the-loop. Instead of using conventional single electroencephalography correlates, e.g., evoked P300 or spontaneous motor imagery, we propose a novel framework integrated two asynchronous signal modalities, i.e., sensorimotor rhythms (SMRs) and movement-related cortical potentials (MRCPs). We executed experiments in a biologically inspired and customized lower-limb exoskeleton where subjects (N = 6) actively controlled the robot using their brain signals. Each subject performed three consecutive sessions composed of offline training, online visual feedback testing, and online robot-control recordings. Post hoc evaluations were conducted including mental workload assessment, feature analysis, and statistics test. An average robot-control accuracy of 80.16% ± 5.44% was obtained with the SMR-based method, while estimation using the MRCP-based method yielded an average performance of 68.62% ± 8.55%. The experimental results showed the feasibility of the proposed framework with all subjects successfully controlled the exoskeleton. The current paradigm could be further extended to paraplegic patients in clinical trials.

Evaluation of the Terminal Sequencing and Spacing System for Performance Based Navigation Arrivals

NASA Technical Reports Server (NTRS)

Thipphavong, Jane; Jung, Jaewoo; Swenson, Harry N.; Martin, Lynne; Lin, Melody; Nguyen, Jimmy

2013-01-01

NASA has developed the Terminal Sequencing and Spacing (TSS) system, a suite of advanced arrival management technologies combining timebased scheduling and controller precision spacing tools. TSS is a ground-based controller automation tool that facilitates sequencing and merging arrivals that have both current standard ATC routes and terminal Performance-Based Navigation (PBN) routes, especially during highly congested demand periods. In collaboration with the FAA and MITRE's Center for Advanced Aviation System Development (CAASD), TSS system performance was evaluated in human-in-the-loop (HITL) simulations with currently active controllers as participants. Traffic scenarios had mixed Area Navigation (RNAV) and Required Navigation Performance (RNP) equipage, where the more advanced RNP-equipped aircraft had preferential treatment with a shorter approach option. Simulation results indicate the TSS system achieved benefits by enabling PBN, while maintaining high throughput rates-10% above baseline demand levels. Flight path predictability improved, where path deviation was reduced by 2 NM on average and variance in the downwind leg length was 75% less. Arrivals flew more fuel-efficient descents for longer, spending an average of 39 seconds less in step-down level altitude segments. Self-reported controller workload was reduced, with statistically significant differences at the p less than 0.01 level. The RNP-equipped arrivals were also able to more frequently capitalize on the benefits of being "Best-Equipped, Best- Served" (BEBS), where less vectoring was needed and nearly all RNP approaches were conducted without interruption.

China Naval Modernization: Implications for U.S. Navy Capabilities -- Background and Issues for Congress

DTIC Science & Technology

2008-04-04

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 04 APR 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to... 1 Issue for Congress

China Naval Modernization: Implications for U.S. Navy Capabilities -- Background and Issues for Congress

DTIC Science & Technology

2008-09-12

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 12 SEP 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008... 1 Issue for Congress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Scope, Sources, and

China Naval Modernization: Implications for U.S. Navy Capabilities - Background and Issues for Congress

DTIC Science & Technology

2008-08-11

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 11 AUG 2008 2. REPORT TYPE N/A 3. DATES COVERED - 4... 1 Issue for Congress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Scope, Sources

China Naval Modernization: Implications for U.S. Navy Capabilities - Background and Issues for Congress

DTIC Science & Technology

2008-02-04

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 04 FEB 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008...events warrant. Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

77 FR 68692 - 1,4-Dimethylnaphthalene; Amendment to an Exemption From the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-16

... across the treatment and control groups and average fetal weights were unaffected. No structural... expanding the current exemption to include all sprouting root and tuber vegetables (EPA Crop Group 01) and all bulb vegetables (EPA Crop Group 03). On behalf of D-I-1-4, Inc., a division of 1,4Group, Inc...

Economic benefits of reducing fire-related sediment in southwestern fire-prone ecosystems

Treesearch

John Loomis; Pete Wohlgemuth; Armando González-Cabán; Don English

2003-01-01

A multiple regression analysis of fire interval and resulting sediment yield (controlling for relief ratio, rainfall, etc.) indicates that reducing the fire interval from the current average 22 years to a prescribed fire interval of 5 years would reduce sediment yield by 2 million cubic meters in the 86.2 square kilometer southern California watershed adjacent to and...

Cold Regions - Environmental Testing of Individual Soldier Equipment

DTIC Science & Technology

2011-10-17

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 17-10-2011 2. REPORT...TOP. 15. SUBJECT TERMS Soldier equipment HFE MANPRINT cold region environment CRTC 16. SECURITY

DSM-5 Autism Spectrum Disorder Symptomology in Fictional Picture Books

ERIC Educational Resources Information Center

Kelley, Jane E.; Cardon, Teresa A.; Algeo-Nichols, Dana

2015-01-01

In the last decade, schools have seen an increasing number of children with autism spectrum disorder (ASD) and the current estimated average of children in the United States who are diagnosed with an ASD is one out of 68 (Centers for Disease Control and Prevention, 2014). One way for educators and elementary students to learn about ASD is through…

Practical experimental certification of computational quantum gates using a twirling procedure.

PubMed

Moussa, Osama; da Silva, Marcus P; Ryan, Colm A; Laflamme, Raymond

2012-08-17

Because of the technical difficulty of building large quantum computers, it is important to be able to estimate how faithful a given implementation is to an ideal quantum computer. The common approach of completely characterizing the computation process via quantum process tomography requires an exponential amount of resources, and thus is not practical even for relatively small devices. We solve this problem by demonstrating that twirling experiments previously used to characterize the average fidelity of quantum memories efficiently can be easily adapted to estimate the average fidelity of the experimental implementation of important quantum computation processes, such as unitaries in the Clifford group, in a practical and efficient manner with applicability in current quantum devices. Using this procedure, we demonstrate state-of-the-art coherent control of an ensemble of magnetic moments of nuclear spins in a single crystal solid by implementing the encoding operation for a 3-qubit code with only a 1% degradation in average fidelity discounting preparation and measurement errors. We also highlight one of the advances that was instrumental in achieving such high fidelity control.

Bioelectrochemical methane (CH4) production in anaerobic digestion at different supplemental voltages.

PubMed

Choi, Kwang-Soon; Kondaveeti, Sanath; Min, Booki

2017-12-01

Microbial electrolysis cells (MECs) at various cell voltages (0.5, 0.7 1.0 and 1.5V) were operated in anaerobic fermentation. During the start-up period, the cathode potential decreased from -0.63 to -1.01V, and CH 4 generation increased from 168 to 199ml. At an applied voltage of 1.0V, the highest methane yields of 408.3ml CH 4 /g COD glucose was obtained, which was 30.3% higher than in the control tests (313.4ml CH 4 /g COD glucose). The average current of 5.1mA was generated at 1.0V at which the maximum methane yield was obtained. The other average currents were 1.42, 3.02, 0.53mA at 0.5, 0.7, and 1.5V, respectively. Cyclic voltammetry and EIS analysis revealed that enhanced reduction currents were present at all cell voltages with biocatalyzed cathode electrodes (no reduction without biofilm), and the highest value was obtained with 1V external voltage. Copyright © 2017 Elsevier Ltd. All rights reserved.

What do farmers' weed control decisions imply about glyphosate resistance? Evidence from surveys of US corn fields.

PubMed

Wechsler, Seth J; McFadden, Jonathan R; Smith, David J

2018-05-01

The first case of glyphosate-resistant weeds in the United States was documented in 1998, 2 years after the commercialization of genetically engineered herbicide-resistant (HR) corn and soybeans. Currently, over 15 glyphosate-resistant weed species affect US crop production areas. These weeds have the potential to reduce yields, increase costs, and lower farm profitability. The objective of our study is to develop a behavioral model of farmers' weed management decisions and use it to analyze weed resistance to glyphosate in US corn farms. On average, we find that weed control increased US corn yields by 3700 kg ha -1 (worth approximately $US 255 ha -1 ) in 2005 and 3500 kg ha -1 (worth approximately $US 575 ha -1 ) in 2010. If glyphosate resistant weeds were absent, glyphosate killed approximately 99% of weeds, on average, when applied at the label rate in HR production systems. Average control was dramatically lower in states where glyphosate resistance was widespread. We find that glyphosate resistance had a significant impact on weed control costs and corn yields of US farmers in 2005 and 2010. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Current data on extremities chronic osteomyelitis in southwest China: epidemiology, microbiology and therapeutic consequences.

PubMed

Wang, Xiaohua; Yu, Shengpeng; Sun, Dong; Fu, Jingshu; Wang, Shulin; Huang, Ke; Xie, Zhao

2017-11-24

The current study was designed to explore the epidemiology of extremities chronic osteomyelitis, its prognosis and the complications of the treatment methods being used in southwest China. The data from osteomyelitis patients treated at the Department of Orthopaedics, Southwest Hospital, China between May 2011 and September 2016 were collected and analysed. The study comprised 503 admitted patients, of which 416 males and 87 were females, with an average age of 40.15 ± 5.64 years. Approximately 356 cases were followed for more than 18 months; the average bone union time was 6.24 ± 0.76 months in 94.1% (335) patients, and infections were almost controlled in 93.8% patients. The rate of infection control with the induced membrane technique was higher than with the I-stage free bone graft. Iliac infection was the main complication of the induced membrane technique, and impaired joint activity was the main complication of I-stage free bone grafts. In southwest China, the incidence of haematogenous osteomyelitis, caused mainly by Staphylococcus aureus, remains very high. The speed of bone defect repair and the rate of infection control with the induced membrane technique were superior to those of I-stage free bone grafts. Internal fixation should be given priority because it offers reduced complications with no increase in the recurrence of infection.

Simulation of an Electromechanical Spin Motor System of a Control Moment Gyroscope

NASA Technical Reports Server (NTRS)

Inampudi, Ravi; Gordeuk, John

2016-01-01

A two-phase brushless DC motor (BDCM) with pulse-width modulated (PWM) voltage drive is simulated to control the flywheel speed of a control moment gyroscope (CMG). An overview of a double-gimballed control moment gyroscope (DGCMG) assembly is presented along with the CMG torque effects on the spacecraft. The operating principles of a two-phase brushless DC motor are presented and the system's electro-mechanical equations of motion are developed for the root-mean-square (RMS) currents and wheel speed. It is shown that the system is an extremely "stiff" set of first-order equations for which an implicit Euler integrator is required for a stable solution. An adaptive proportional voltage controller is presented which adjusts the PWM voltages depending on several control modes for speed, current, and torque. The simulation results illustrate the interaction between the electrical system and the load dynamics and how these influence the overall performance of the system. As will be shown, the CMG spin motor model can directly provide electrical power use and thermal power output to spacecraft subsystems for effective (average) calculations of CMG power consumption.

Control algorithms for dynamic attenuators.

PubMed

Hsieh, Scott S; Pelc, Norbert J

2014-06-01

The authors describe algorithms to control dynamic attenuators in CT and compare their performance using simulated scans. Dynamic attenuators are prepatient beam shaping filters that modulate the distribution of x-ray fluence incident on the patient on a view-by-view basis. These attenuators can reduce dose while improving key image quality metrics such as peak or mean variance. In each view, the attenuator presents several degrees of freedom which may be individually adjusted. The total number of degrees of freedom across all views is very large, making many optimization techniques impractical. The authors develop a theory for optimally controlling these attenuators. Special attention is paid to a theoretically perfect attenuator which controls the fluence for each ray individually, but the authors also investigate and compare three other, practical attenuator designs which have been previously proposed: the piecewise-linear attenuator, the translating attenuator, and the double wedge attenuator. The authors pose and solve the optimization problems of minimizing the mean and peak variance subject to a fixed dose limit. For a perfect attenuator and mean variance minimization, this problem can be solved in simple, closed form. For other attenuator designs, the problem can be decomposed into separate problems for each view to greatly reduce the computational complexity. Peak variance minimization can be approximately solved using iterated, weighted mean variance (WMV) minimization. Also, the authors develop heuristics for the perfect and piecewise-linear attenuators which do not require a priori knowledge of the patient anatomy. The authors compare these control algorithms on different types of dynamic attenuators using simulated raw data from forward projected DICOM files of a thorax and an abdomen. The translating and double wedge attenuators reduce dose by an average of 30% relative to current techniques (bowtie filter with tube current modulation) without increasing peak variance. The 15-element piecewise-linear dynamic attenuator reduces dose by an average of 42%, and the perfect attenuator reduces dose by an average of 50%. Improvements in peak variance are several times larger than improvements in mean variance. Heuristic control eliminates the need for a prescan. For the piecewise-linear attenuator, the cost of heuristic control is an increase in dose of 9%. The proposed iterated WMV minimization produces results that are within a few percent of the true solution. Dynamic attenuators show potential for significant dose reduction. A wide class of dynamic attenuators can be accurately controlled using the described methods.

Performance of Mashona doelings supplemented with different levels of velvet bean (Mucuna pruriens L. DC. var. utilis) seed meal.

PubMed

Madzimure, James; Mutema, Nyasha; Chimonyo, Michael; Bakare, Archibold Garikai; Mapiye, Cletos

2014-06-01

The objective of the current study was to evaluate the effects of feeding increasing levels of velvet bean seed meal (VBM; 0, 12, 24, and 36 %) on the performance of Mashona doelings. Dry matter intake was lower (P < 0.05) for the control diet compared to VBM diets, but linearly declined (P < 0.05) with increasing levels of VBM. Average daily weight gain was significantly different between experimental groups. Doelings' final live weights and average daily gains were slightly higher in control group than other three supplemented groups where they linearly declined (P < 0.05) with increasing levels of VBM. The cost per kilogram of feed, however, decreased with high inclusion level of VBM. Result suggested that high inclusion level of VBM negatively influenced the growth of young goats probably due to the presence of some anti-nutritional factors which needs further investigation.

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

Osterwald, C. R.; Anderberg, A.; Rummel, S.

We present an analysis of the results of a solar weathering program that found a linear relationship between maximum power degradation and the total UV exposure dose for four different types of commercial crystalline Si modules. The average degradation rate for the four modules types was 0.71% per year. The analysis showed that losses of short-circuit current were responsible for the maximum power degradation. Judging by the appearance of the undegraded control modules, it is very doubtful that the short-circuit current losses were caused by encapsulation browning or obscuration. When we compared the quantum efficiency of a single cell inmore » a degraded module to one from an unexposed control module, it appears that most of the degradation has occurred in the 800 - 1100 nm wave-length region, and not the short wavelength region.« less

Prevention of Blast-Related Injuries

DTIC Science & Technology

2013-07-01

collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources...of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE...Introduction 4 Statement of Work 4 Task I Report 4 1 . Adjustment of the experimental design and methodology 4 2. Preparations for Blast

China Naval Modernization: Implications for U.S. Navy Capabilities - Background and Issues for Congress

DTIC Science & Technology

2008-10-08

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 08 OCT 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to... 1 Issue for Congress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Scope, Sources, and

China Naval Modernization: Implications for U.S. Navy Capabilities -- Background and Issues for Congress

DTIC Science & Technology

2008-07-10

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 10 JUL 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00... 1 Issue for Congress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Scope, Sources, and

China Naval Modernization: Implications for U.S. Navy Capabilities - Background and Issues for Congress

DTIC Science & Technology

2008-11-19

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 19 NOV 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to... 1 Issue for Congress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Scope, Sources, and

Nitrogen Rings and Cages Stabilized by Metallic Atoms

DTIC Science & Technology

2009-12-18

1 UNIVERSIDAD DE GUANAJUATO DEPARTAMENTO DE QUIMICA DIVISION DE CIENCIAS NATURALES Y EXACTAS Dr. Gabriel Merino NORIA ALTA s/n...this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data...collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT

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

Rau, E. I.; Orlikovskiy, N. A.; Ivanova, E. S.

A new highly efficient design for semiconductor detectors of intermediate-energy electrons (1-50 keV) for application in scanning electron microscopes is proposed. Calculations of the response function of advanced detectors and control experiments show that the efficiency of the developed devices increases on average twofold, which is a significant positive factor in the operation of modern electron microscopes in the mode of low currents and at low primary electron energies.

Test Operations Procedure (TOP) 2-2-650 Engine Cold-Starting and Warm-Up Tests

DTIC Science & Technology

2008-02-12

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 12-02-2008 2. REPORT...Page Paragraph 1 . SCOPE................................................................................ 2 2. FACILITIES AND INSTRUMENTATION

Investigation of Chemical Reactivity, Mass Recovery and Biological Activity During Thermal Treatment of DNAPL Source Zones

DTIC Science & Technology

2009-10-01

Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response...penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE OCT 2009 2...xvi E. 1 . Research Approach .........................................................................................................xvi E.2

Computational Biomathematics: Toward Optimal Control of Complex Biological Systems

DTIC Science & Technology

2016-09-26

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing...comments regarding this burden estimate or any other aspect of this collection of information, including suggesstions for reducing this burden, to...equations seems daunting. However, we are currently working on parameter estimation methods that show some promise. In this approach, we generate data from

Enhanced Vaccine Control of Epidemics in Adaptive Networks

DTIC Science & Technology

2010-04-29

than random vaccination 32. When vaccine is very limited, outbreaks can be minimized by fragmenting the network via a graph partitioning strategy...Although an outbreak could transiently decrease network connectivity in a real social network, long term reductions in average connectivity are...37, cholera and typhoid fever 35, as well as pertussis 38. Although not all of the above diseases currently possess a vaccine, research is ongo

29 CFR 548.306 - Average earnings for year or quarter year preceding the current quarter.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PAY Interpretations Authorized Basic Rates § 548.306 Average earnings for year or quarter year... regular rates of pay during the current quarter year, and (ii) such average hourly remuneration during the... 29 Labor 3 2011-07-01 2011-07-01 false Average earnings for year or quarter year preceding the...

Direct measurement of the rates of synthesis of plasma proteins in control subjects and patients with gastrointestinal protein loss

PubMed Central

Wochner, R. Dean; Weissman, Sherman M.; Waldmann, Thomas A.; Houston, Delores; Berlin, Nathaniel I.

1968-01-01

The guanido carbon of hepatic arginine is the common precursor of urea and of the arginine of plasma proteins synthesized in the liver. It is possible to measure the momentary synthetic rates of plasma proteins by “pulse labeling” this arginine pool with bicarbonate-14C. In the current study, this method has been adapted in order to use urinary urea data and was applied to control subjects and patients with gastrointestinal protein loss. The assumptions required for this determination are discussed. There was close agreement between albumin synthetic rates measured by this method and albumin catabolic rates derived from simultaneous albumin-131I studies, supporting the validity of the method and suggesting that there is relatively little fluctuation in the rate of albumin synthesis from time to time. The albumin synthetic rates in six control subjects averaged 5.8 mg/kg per hr, while those of five patients with gastrointestinal protein loss averaged 7.2 mg/kg per hr. Thus in these patients, there was relatively little acceleration of albumin synthesis in response to continued loss of plasma proteins into the gastrointestinal tract. Fibrinogen synthetic rates averaged 1.9 mg/kg per hr in five control subjects and 3.2 mg/kg per hr in five patients with gastrointestinal protein loss. Transferrin synthetic rates exhibited considerable individual variation in both groups and averaged 0.24 mg/kg per hr in four control subjects and 0.31 mg/kg per hr in five patients with gastrointestinal protein loss. The method employed in this study offers several advantages in studying plasma protein metabolism. It provides a direct measurement of protein synthesis, applicable to several proteins simultaneously, does not require a long-term steady state in the metabolism of the proteins, and is capable of measuring short-term fluctuations in synthetic rates. Therefore, this approach is applicable to the investigation of the physiological factors controlling the rates of synthesis for plasma proteins. PMID:5239039

Comparison of control structures for a bidirectional high-frequency dc-dc converter

NASA Astrophysics Data System (ADS)

Himmelstoss, Felix A.; Kolar, Johann W.; Zach, Franz C.

1989-08-01

A system for dc-dc power conversion based on a buck-boost converter topology is presented. It makes power flow in both directions possible. The possibility of bidirectional power flow is useful for certain applications, such as uninterruptable power supplies. Starting from a structural diagram the transfer function of the system is derived. The controller for the converter is then designed. It is made up of a simple voltage controller, a voltage controller with an inner loop current controller (cascade control) and with two kinds of state space control. The transfer functions of the different system parts are derived and dimensioning guidelines for the controller sections are presented. The closed loop behavior of the bidirectional converter for the different control structures is analyzed based on simulation using duty cycle averaging. Bodediagrams and step responses are shown.

Fault-scale controls on rift geometry: the Bilila-Mtakataka Fault, Malawi

NASA Astrophysics Data System (ADS)

Hodge, M.; Fagereng, A.; Biggs, J.; Mdala, H. S.

2017-12-01

Border faults that develop during initial stages of rifting determine the geometry of rifts and passive margins. At outcrop and regional scales, it has been suggested that border fault orientation may be controlled by reactivation of pre-existing weaknesses. Here, we perform a multi-scale investigation on the influence of anisotropic fabrics along a major developing border fault in the southern East African Rift, Malawi. The 130 km long Bilila-Mtakataka fault has been proposed to have slipped in a single MW 8 earthquake with 10 m of normal displacement. The fault is marked by an 11±7 m high scarp with an average trend that is oblique to the current plate motion. Variations in scarp height are greatest at lithological boundaries and where the scarp switches between following and cross-cutting high-grade metamorphic foliation. Based on the scarp's geometry and morphology, we define 6 geometrically distinct segments. We suggest that the segments link to at least one deeper structure that strikes parallel to the average scarp trend, an orientation consistent with the kinematics of an early phase of rift initiation. The slip required on a deep fault(s) to match the height of the current scarp suggests multiple earthquakes along the fault. We test this hypothesis by studying the scarp morphology using high-resolution satellite data. Our results suggest that during the earthquake(s) that formed the current scarp, the propagation of the fault toward the surface locally followed moderately-dipping foliation well oriented for reactivation. In conclusion, although well oriented pre-existing weaknesses locally influence shallow fault geometry, large-scale border fault geometry appears primarily controlled by the stress field at the time of fault initiation.

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

Bohner, Bíborka; Endrődi, Balázs; Tóth, Ágota, E-mail: atoth@chem.u-szeged.hu

The precipitation reaction of calcium oxalate is studied experimentally in the presence of spatial gradients by controlled flow of calcium into oxalate solution. The density difference between the reactants leads to strong convection in the form of a gravity current that drives the spatiotemporal pattern formation. The phase diagram of the system is constructed, the evolving precipitate patterns are analyzed and quantitatively characterized by their diameters and the average height of the gravity flow. The compact structures of calcium oxalate monohydrate produced at low flow rates are replaced by the thermodynamically unstable calcium oxalate dihydrate favored in the presence ofmore » a strong gravity current.« less

On residents' satisfaction with community health services after health care system reform in Shanghai, China, 2011.

PubMed

Li, Zhijian; Hou, Jiale; Lu, Lin; Tang, Shenglan; Ma, Jin

2012-01-01

Health care system reform is a major issue in many countries and therefore how to evaluate the effects of changes is incredibly important. This study measured residents' satisfaction with community health care service in Shanghai, China, and aimed to evaluate the effect of recent health care system reform. Face-to-face interviews were performed with a stratified random sample of 2212 residents of the Shanghai residents using structured questionnaires. In addition, 972 valid responses were retrieved from internet contact. Controlling for sex, age, income and education, the study used logistic regression modeling to analyze factors associated with satisfaction and to explain the factors that affect the residents' satisfaction. Comparing current attitudes with those held at the initial implementation of the reform in this investigation, four dimensions of health care were analyzed: 1) the health insurance system; 2) essential drugs; 3) basic clinical services; and 4) public health services. Satisfaction across all dimensions improved since the reform was initiated, but differences of satisfaction level were found among most dimensions and groups. Residents currently expressed greater satisfaction with clinical service (average score=3.79, with 5 being most satisfied) and the public health/preventive services (average score=3.62); but less satisfied with the provision of essential drugs (average score=3.20) and health insurance schemes (average score=3.23). The disadvantaged groups (the elderly, the retired, those with only an elementary education, those with lower incomes) had overall poorer satisfaction levels on these four aspects of health care (P<0.01). 25.39% of the respondents thought that their financial burden had increased and 38.49% thought that drugs had become more expensive. The respondents showed more satisfaction with the clinical services (average score=3.79) and public health services/interventions (average score=3.79); and less satisfaction with the health insurance system (average score=3.23) and the essential drug system (average score=3.20). Disadvantaged groups showed lower satisfaction levels overall relative to non-disadvantaged groups.

Ionic currents in the guinea-pig taenia coli.

PubMed Central

Inomata, H; Kao, C Y

1976-01-01

Short segments of portions of taenia coli of the guinea-pig averaging 54 mum X 219 mum X ca. 200 mum have been studied by a double sucrose-gap voltage-clamp technique. 2. The average total capacitance was 0-4 muF, corresponding to approximately 10(4) cells, if a specific membrane capacitance of 3 muF/cm2 were assumed. 3. A significant resistance, averaging 11-4omega, was in series with the membrane, and seriously limited the accuracy of the voltage control possible. 4. On depolarization, an early transient inward current was followed by a late maintained outwary current. 5. The late current was carried mainly by K+, because its direction could be reversed if the preparation were first depolarized in isotonic K2SO4 and held back to the original resting potential. 6. After appropriate corrections for residual capacitative and leakage currents, a reversal potential for the late current (Eb) was determined to be 15-20 mV more negative than the natural resting potential. It was not affected by the amplitude or the duration of the activating voltage step, but could be changed by prolonged applications of holding current. 7. At rest, the ratio of PNa:PK was 0-16:1; for Eb it was 0-05:1. 8. The reversal potential for the transient early inward current (Ea) averaged 22 mV in Krebs-bicarbonate solution, but was shifted to about 35 mV when the late current was first suppressed with tetraethylammonium ion. The shift suggested that there was some overlap of the early and late currents. 9. Reduction of [Na+]o to 50% of normal, or replacement of all Na+ with dimethyldiethanol ammonium ion and choline ion, failed to cause any significant shifts in the reversal potential of the early current or reduce the magnitude of the early current. 10. Reduction of [Ca2+]o to 0-25 or 0-1 of the normal caused shifts of the Ea toward the negative and reductions in the early current. These changes can occur without changes in the maximum chord conductance of the early current, such as might happen in ordinary Krebs-bicarbonate solution, or in preparations which had been depolarized by prior treatment with isotonic K2SO4 and then held back to the original membrane voltage. 11. Increase of [Ca2+]o to 5 times normal increased the early inward current, and the maximum chord conductances of the early and late currents, but did not shift the Ea. 12. In preparations pretreated with TEA, increasing [Ca2+]o to 5 times normal shifted Ea toward 45 mV. 13. The various observations are interpreted to mean that the early current in the taenia coli is carried principally by influx of Ca2+, and not by Na+. PMID:1255524

Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe.

PubMed

Prevosto, L; Kelly, H; Mancinelli, B

2013-12-01

This work describes the application of Langmuir probe diagnostics to the measurement of the electron temperature in a time-fluctuating-highly ionized, non-equilibrium cutting arc. The electron retarding part of the time-averaged current-voltage characteristic of the probe was analysed, assuming that the standard exponential expression describing the electron current to the probe in collision-free plasmas can be applied under the investigated conditions. A procedure is described which allows the determination of the errors introduced in time-averaged probe data due to small-amplitude plasma fluctuations. It was found that the experimental points can be gathered into two well defined groups allowing defining two quite different averaged electron temperature values. In the low-current region the averaged characteristic was not significantly disturbed by the fluctuations and can reliably be used to obtain the actual value of the averaged electron temperature. In particular, an averaged electron temperature of 0.98 ± 0.07 eV (= 11400 ± 800 K) was found for the central core of the arc (30 A) at 3.5 mm downstream from the nozzle exit. This average included not only a time-average over the time fluctuations but also a spatial-average along the probe collecting length. The fitting of the high-current region of the characteristic using such electron temperature value together with the corrections given by the fluctuation analysis showed a relevant departure of local thermal equilibrium in the arc core.

Glycemic penalty index for adequately assessing and comparing different blood glucose control algorithms

PubMed Central

Van Herpe, Tom; De Brabanter, Jos; Beullens, Martine; De Moor, Bart; Van den Berghe, Greet

2008-01-01

Introduction Blood glucose (BG) control performed by intensive care unit (ICU) nurses is becoming standard practice for critically ill patients. New (semi-automated) 'BG control' algorithms (or 'insulin titration' algorithms) are under development, but these require stringent validation before they can replace the currently used algorithms. Existing methods for objectively comparing different insulin titration algorithms show weaknesses. In the current study, a new approach for appropriately assessing the adequacy of different algorithms is proposed. Methods Two ICU patient populations (with different baseline characteristics) were studied, both treated with a similar 'nurse-driven' insulin titration algorithm targeting BG levels of 80 to 110 mg/dl. A new method for objectively evaluating BG deviations from normoglycemia was founded on a smooth penalty function. Next, the performance of this new evaluation tool was compared with the current standard assessment methods, on an individual as well as a population basis. Finally, the impact of four selected parameters (the average BG sampling frequency, the duration of algorithm application, the severity of disease, and the type of illness) on the performance of an insulin titration algorithm was determined by multiple regression analysis. Results The glycemic penalty index (GPI) was proposed as a tool for assessing the overall glycemic control behavior in ICU patients. The GPI of a patient is the average of all penalties that are individually assigned to each measured BG value based on the optimized smooth penalty function. The computation of this index returns a number between 0 (no penalty) and 100 (the highest penalty). For some patients, the assessment of the BG control behavior using the traditional standard evaluation methods was different from the evaluation with GPI. Two parameters were found to have a significant impact on GPI: the BG sampling frequency and the duration of algorithm application. A higher BG sampling frequency and a longer algorithm application duration resulted in an apparently better performance, as indicated by a lower GPI. Conclusion The GPI is an alternative method for evaluating the performance of BG control algorithms. The blood glucose sampling frequency and the duration of algorithm application should be similar when comparing algorithms. PMID:18302732

Low-sensitivity, low-bounce, high-linearity current-controlled oscillator suitable for single-supply mixed-mode instrumentation system.

PubMed

Hwang, Yuh-Shyan; Kung, Che-Min; Lin, Ho-Cheng; Chen, Jiann-Jong

2009-02-01

A low-sensitivity, low-bounce, high-linearity current-controlled oscillator (CCO) suitable for a single-supply mixed-mode instrumentation system is designed and proposed in this paper. The designed CCO can be operated at low voltage (2 V). The power bounce and ground bounce generated by this CCO is less than 7 mVpp when the power-line parasitic inductance is increased to 100 nH to demonstrate the effect of power bounce and ground bounce. The power supply noise caused by the proposed CCO is less than 0.35% in reference to the 2 V supply voltage. The average conversion ratio KCCO is equal to 123.5 GHz/A. The linearity of conversion ratio is high and its tolerance is within +/-1.2%. The sensitivity of the proposed CCO is nearly independent of the power supply voltage, which is less than a conventional current-starved oscillator. The performance of the proposed CCO has been compared with the current-starved oscillator. It is shown that the proposed CCO is suitable for single-supply mixed-mode instrumentation systems.

Cost of malaria control in China: Henan's consolidation programme from community and government perspectives.

PubMed Central

Jackson, Sukhan; Sleigh, Adrian C.; Liu, Xi-Li

2002-01-01

OBJECTIVE: To assist with strategic planning for the eradication of malaria in Henan Province, China, which reached the consolidation phase of malaria control in 1992, when only 318 malaria cases were reported. METHODS: We conducted a prospective two-year study of the costs for Henan's malaria control programme. We used a cost model that could also be applied to other malaria programmes in mainland China, and analysed the cost of the three components of Henan's malaria programme: suspected malaria case management, vector surveillance, and population blood surveys. Primary cost data were collected from the government, and data on suspected malaria patients were collected in two malaria counties (population 2 093 100). We enlisted the help of 260 village doctors in six townships or former communes (population 247 762), and studied all 12 325 reported cases of suspected malaria in their catchment areas in 1994 and 1995. FINDINGS: The average annual government investment in malaria control was estimated to be US$ 111 516 (case-management 59%; active blood surveys 25%; vector surveillance 12%; and contingencies and special projects 4%). The average cost (direct and indirect) for patients seeking treatment for suspected malaria was US$ 3.48, equivalent to 10 days' income for rural residents. Each suspected malaria case cost the government an average of US$ 0.78. CONCLUSION: Further cuts in government funding will increase future costs when epidemic malaria returns; investment in malaria control should therefore continue at least at current levels of US$ 0.03 per person at risk. PMID:12219157

A standardized model for predicting flap failure using indocyanine green dye

NASA Astrophysics Data System (ADS)

Zimmermann, Terence M.; Moore, Lindsay S.; Warram, Jason M.; Greene, Benjamin J.; Nakhmani, Arie; Korb, Melissa L.; Rosenthal, Eben L.

2016-03-01

Techniques that provide a non-invasive method for evaluation of intraoperative skin flap perfusion are currently available but underutilized. We hypothesize that intraoperative vascular imaging can be used to reliably assess skin flap perfusion and elucidate areas of future necrosis by means of a standardized critical perfusion threshold. Five animal groups (negative controls, n=4; positive controls, n=5; chemotherapy group, n=5; radiation group, n=5; chemoradiation group, n=5) underwent pre-flap treatments two weeks prior to undergoing random pattern dorsal fasciocutaneous flaps with a length to width ratio of 2:1 (3 x 1.5 cm). Flap perfusion was assessed via laser-assisted indocyanine green dye angiography and compared to standard clinical assessment for predictive accuracy of flap necrosis. For estimating flap-failure, clinical prediction achieved a sensitivity of 79.3% and a specificity of 90.5%. When average flap perfusion was more than three standard deviations below the average flap perfusion for the negative control group at the time of the flap procedure (144.3+/-17.05 absolute perfusion units), laser-assisted indocyanine green dye angiography achieved a sensitivity of 81.1% and a specificity of 97.3%. When absolute perfusion units were seven standard deviations below the average flap perfusion for the negative control group, specificity of necrosis prediction was 100%. Quantitative absolute perfusion units can improve specificity for intraoperative prediction of viable tissue. Using this strategy, a positive predictive threshold of flap failure can be standardized for clinical use.

DOD HPC Insights. Spring 2012

DTIC Science & Technology

2012-04-01

spr2012-Final.indd 1 5/9/2012 10:54:32 AM DOD Spring 2012 INSIGHTS A publication of the Department of Defense High Performance Computing...0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing...collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 2012 2. REPORT TYPE 3. DATES COVERED 4. TITLE

Bridging the Gap (BRIEFING CHARTS)

DTIC Science & Technology

2007-03-05

1 Defense Advanced Research Projects Agency “Bridging the Gap” Dr. Robert F. Leheny Deputy Director Report Documentation Page Form ApprovedOMB No...0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing...collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 05 MAR 2007 2. REPORT TYPE N/A 3. DATES COVERED

Unmanned Systems Roadmap 2007-2032

DTIC Science & Technology

2007-01-01

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE...unmanned systems technology to ensure an effective return on the Department’s investment. 1 . Reconnaissance and Surveillance. Some form of reconnaissance

Minimization of Thruster Plume Effects on Spacecraft Surfaces

DTIC Science & Technology

2007-05-01

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 26-03-2007 2. REPORT TYPE...Approved for public release; distribution is unlimited 1 The surfaces from user-defined CAD models of the spacecraft are loaded into COLISEUM

Synthesis of Chromophores for Nonlinear Optics Applications

DTIC Science & Technology

2010-03-12

Investigacion de Quimica Aplicada Blvd. Enrique reyna, No. 140 Saltillo, Coahuila, Mexico 25253 AFOSR FA9550-09- 1 -0017 12 March 2010...estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the...does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 12-03-2010

The Interoperability Score

DTIC Science & Technology

2007-03-01

Additionally, research shows that many over the past decade have proposed interoperability measures, notable of which have been: 1 ) the DoD...Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the...to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE MAR 2007 2. REPORT TYPE 3

Launch and Recovery System Literature Review

DTIC Science & Technology

2010-12-01

information is estimated to average 1 hour per response, including the time for reviewing instruction, searching existing data sources, gathering and...maintaining the data needed, and completing and reviewing he collection of information. Send comments regarding this burden estimate or any other aspect...if it does not display a currently valid OMB control number. PLEASE DO NOT RETURNYOU FORM TO THE AVOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 31-12

Radiative Transfer in Submerged Macrophyte Canopies

DTIC Science & Technology

2001-09-30

estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources , gathering and maintaining the data...needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection...person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control

Fluorescent Lamp Replacement Study

DTIC Science & Technology

2017-07-01

DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour per...information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. 1. REPORT DATE (DD-MM...Unclassified 19b. TELEPHONE NUMBER (Include area code) Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 TABLE OF CONTENTS

Artificial Intelligence: A Revolution Waiting to Happen

DTIC Science & Technology

2017-06-09

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 9-06-2017 2. REPORT TYPE...important RMAs, limited by innovative concepts and organizational desire to change. General AI, on the other hand, looms in theoretical form as a

Restructuring Civil Affairs for Persistent Engagement

DTIC Science & Technology

2010-04-29

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour...and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 29-04-2010 2. REPORT TYPE SAMS

The Contribution of Music to the Fluent Writing Skills: Mayaz Technique

ERIC Educational Resources Information Center

Batur, Zekerya

2016-01-01

This is an experimental study. In this study, experimental and control groups have been formed based on the scores obtained from Turkish language exams. The study group consists of 80 pupils currently studying in the 5th and 6th grades of the secondary school who have an average GPA of 70 to 80 (of the 5th grade pupils, 20 of them are in the…

Junction-to-Case Thermal Resistance of a Silicon Carbide Bipolar Junction Transistor Measured

NASA Technical Reports Server (NTRS)

Niedra, Janis M.

2006-01-01

Junction temperature of a prototype SiC-based bipolar junction transistor (BJT) was estimated by using the base-emitter voltage (V(sub BE)) characteristic for thermometry. The V(sub BE) was measured as a function of the base current (I(sub B)) at selected temperatures (T), all at a fixed collector current (I(sub C)) and under very low duty cycle pulse conditions. Under such conditions, the average temperature of the chip was taken to be the same as that of the temperature-controlled case. At increased duty cycle such as to substantially heat the chip, but same I(sub C) pulse height, the chip temperature was identified by matching the V(sub BE) to the thermometry curves. From the measured average power, the chip-to-case thermal resistance could be estimated, giving a reasonable value. A tentative explanation for an observed bunching with increasing temperature of the calibration curves may relate to an increasing dopant atom ionization. A first-cut analysis, however, does not support this.

Estimating patient dose from CT exams that use automatic exposure control: Development and validation of methods to accurately estimate tube current values.

PubMed

McMillan, Kyle; Bostani, Maryam; Cagnon, Christopher H; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia H; McNitt-Gray, Michael F

2017-08-01

The vast majority of body CT exams are performed with automatic exposure control (AEC), which adapts the mean tube current to the patient size and modulates the tube current either angularly, longitudinally or both. However, most radiation dose estimation tools are based on fixed tube current scans. Accurate estimates of patient dose from AEC scans require knowledge of the tube current values, which is usually unavailable. The purpose of this work was to develop and validate methods to accurately estimate the tube current values prescribed by one manufacturer's AEC system to enable accurate estimates of patient dose. Methods were developed that took into account available patient attenuation information, user selected image quality reference parameters and x-ray system limits to estimate tube current values for patient scans. Methods consistent with AAPM Report 220 were developed that used patient attenuation data that were: (a) supplied by the manufacturer in the CT localizer radiograph and (b) based on a simulated CT localizer radiograph derived from image data. For comparison, actual tube current values were extracted from the projection data of each patient. Validation of each approach was based on data collected from 40 pediatric and adult patients who received clinically indicated chest (n = 20) and abdomen/pelvis (n = 20) scans on a 64 slice multidetector row CT (Sensation 64, Siemens Healthcare, Forchheim, Germany). For each patient dataset, the following were collected with Institutional Review Board (IRB) approval: (a) projection data containing actual tube current values at each projection view, (b) CT localizer radiograph (topogram) and (c) reconstructed image data. Tube current values were estimated based on the actual topogram (actual-topo) as well as the simulated topogram based on image data (sim-topo). Each of these was compared to the actual tube current values from the patient scan. In addition, to assess the accuracy of each method in estimating patient organ doses, Monte Carlo simulations were performed by creating voxelized models of each patient, identifying key organs and incorporating tube current values into the simulations to estimate dose to the lungs and breasts (females only) for chest scans and the liver, kidney, and spleen for abdomen/pelvis scans. Organ doses from simulations using the actual tube current values were compared to those using each of the estimated tube current values (actual-topo and sim-topo). When compared to the actual tube current values, the average error for tube current values estimated from the actual topogram (actual-topo) and simulated topogram (sim-topo) was 3.9% and 5.8% respectively. For Monte Carlo simulations of chest CT exams using the actual tube current values and estimated tube current values (based on the actual-topo and sim-topo methods), the average differences for lung and breast doses ranged from 3.4% to 6.6%. For abdomen/pelvis exams, the average differences for liver, kidney, and spleen doses ranged from 4.2% to 5.3%. Strong agreement between organ doses estimated using actual and estimated tube current values provides validation of both methods for estimating tube current values based on data provided in the topogram or simulated from image data. © 2017 American Association of Physicists in Medicine.

Room-temperature observation and current control of skyrmions in Pt/Co/Os/Pt thin films

NASA Astrophysics Data System (ADS)

Tolley, R.; Montoya, S. A.; Fullerton, E. E.

2018-04-01

We report the observation of room-temperature magnetic skyrmions in Pt/Co/Os/Pt thin-film heterostructures and their response to electric currents. The magnetic properties are extremely sensitive to inserting thin Os layers between the Co-Pt interface, resulting in reduced saturation magnetization, magnetic anisotropy, and Curie temperature. The observed skyrmions exist in a narrow temperature, applied-field and layer-thickness range near the spin-reorientation transition from perpendicular to in-plane magnetic anisotropy. The skyrmions have an average diameter of 2.3 μ m and transport measurements demonstrate these features can be displaced by means of spin-orbit torques with current densities as low as J =2 ×108A / m2 and display a skyrmion Hall effect.

Quantization and fractional quantization of currents in periodically driven stochastic systems. I. Average currents

NASA Astrophysics Data System (ADS)

Chernyak, Vladimir Y.; Klein, John R.; Sinitsyn, Nikolai A.

2012-04-01

This article studies Markovian stochastic motion of a particle on a graph with finite number of nodes and periodically time-dependent transition rates that satisfy the detailed balance condition at any time. We show that under general conditions, the currents in the system on average become quantized or fractionally quantized for adiabatic driving at sufficiently low temperature. We develop the quantitative theory of this quantization and interpret it in terms of topological invariants. By implementing the celebrated Kirchhoff theorem we derive a general and explicit formula for the average generated current that plays a role of an efficient tool for treating the current quantization effects.

Legacies of precipitation fluctuations on primary production: theory and data synthesis.

PubMed

Sala, Osvaldo E; Gherardi, Laureano A; Reichmann, Lara; Jobbágy, Esteban; Peters, Debra

2012-11-19

Variability of above-ground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space (based on multiyear averages for different locations) than through time (based on year-to-year change at single locations). Here, we propose a theory of controls of ANPP based on four hypotheses about legacies of wet and dry years that explains space versus time differences in ANPP-precipitation relationships. We tested the hypotheses using 16 long-term series of ANPP. We found that legacies revealed by the association of current- versus previous-year conditions through the temporal series occur across all ecosystem types from deserts to mesic grasslands. Therefore, previous-year precipitation and ANPP control a significant fraction of current-year production. We developed unified models for the controls of ANPP through space and time. The relative importance of current-versus previous-year precipitation changes along a gradient of mean annual precipitation with the importance of current-year PPT decreasing, whereas the importance of previous-year PPT remains constant as mean annual precipitation increases. Finally, our results suggest that ANPP will respond to climate-change-driven alterations in water availability and, more importantly, that the magnitude of the response will increase with time.

Nonlinear Dynamics and Bifurcation Analysis of a Boost Converter for Battery Charging in Photovoltaic Applications

NASA Astrophysics Data System (ADS)

Al-Hindawi, Mohammed M.; Abusorrah, Abdullah; Al-Turki, Yusuf; Giaouris, Damian; Mandal, Kuntal; Banerjee, Soumitro

Photovoltaic (PV) systems with a battery back-up form an integral part of distributed generation systems and therefore have recently attracted a lot of interest. In this paper, we consider a system of charging a battery from a PV panel through a current mode controlled boost dc-dc converter. We analyze its complete nonlinear/nonsmooth dynamics, using a piecewise model of the converter and realistic nonlinear v-i characteristics of the PV panel. Through this study, it is revealed that system design without taking into account the nonsmooth dynamics of the converter combined with the nonlinear v-i characteristics of the PV panel can lead to unpredictable responses of the overall system with high current ripple and other undesirable phenomena. This analysis can lead to better designed converters that can operate under a wide variation of the solar irradiation and the battery's state of charge. We show that the v-i characteristics of the PV panel combined with the battery's output voltage variation can increase or decrease the converter's robustness, both under peak current mode control and average current mode control. We justify the observation in terms of the change in the discrete-time map caused by the nonlinear v-i characteristics of the PV panel. The theoretical results are validated experimentally.

Towards the control of the modal energy transfer in transverse mode instabilities

NASA Astrophysics Data System (ADS)

Stihler, Christoph; Jauregui, Cesar; Tünnermann, Andreas; Limpert, Jens

2018-02-01

Thermally-induced refractive index gratings (RIG) in high-power fiber laser systems lead to transverse mode instabilities (TMI) above a certain average power threshold. The effect of TMI is currently the main limitation for the further average power scaling of fiber lasers and amplifiers with nearly diffraction-limited beam quality. In this work we experimentally investigate, for the first time, the growth of the RIG strength by introducing a phase-shift between the RIG and the modal interference pattern in a fiber amplifier. The experiments reveal that the RIG is strong enough to couple energy between different transverse modes even at powers significantly below the TMI threshold, provided that the introduced phase-shift is high enough. This indicates that, as the strength of the RIG further increases with increasing average output power, the RIG becomes more and more sensitive to even small noise-induced phase-shifts, which ultimately trigger TMI. Furthermore, it is shown that a beam cleaning also occurs when a positive phase-shift is introduced, even above the TMI threshold. This finding will pave the way for the development of a new class of mitigation strategies for TMI, which key feature is the control of the introduced phase-shift.

Design of a 3 kW wind turbine generator with thin airfoil blades

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

Ameku, Kazumasa; Nagai, Baku M.; Roy, Jitendro Nath

2008-09-15

Three blades of a 3 kW prototype wind turbine generator were designed with thin airfoil and a tip speed ratio of 3. The wind turbine has been controlled via two control methods: the variable pitch angle and by regulation of the field current of the generator and examined under real wind conditions. The characteristics of the thin airfoil, called ''Seven arcs thin airfoil'' named so because the airfoil is composed of seven circular arcs, are analyzed with the airfoil design and analysis program XFOIL. The thin airfoil blade is designed and calculated by blade element and momentum theory. The performancemore » characteristics of the machine such as rotational speed, generator output as well as stability for wind speed changes are described. In the case of average wind speeds of 10 m/s and a maximum of 19 m/s, the automatically controlled wind turbine ran safely through rough wind conditions and showed an average generator output of 1105 W and a power coefficient 0.14. (author)« less

Learned helplessness and learned prevalence: exploring the causal relations among perceived controllability, reward prevalence, and exploration.

PubMed

Teodorescu, Kinneret; Erev, Ido

2014-10-01

Exposure to uncontrollable outcomes has been found to trigger learned helplessness, a state in which the agent, because of lack of exploration, fails to take advantage of regained control. Although the implications of this phenomenon have been widely studied, its underlying cause remains undetermined. One can learn not to explore because the environment is uncontrollable, because the average reinforcement for exploring is low, or because rewards for exploring are rare. In the current research, we tested a simple experimental paradigm that contrasts the predictions of these three contributors and offers a unified psychological mechanism that underlies the observed phenomena. Our results demonstrate that learned helplessness is not correlated with either the perceived controllability of one's environment or the average reward, which suggests that reward prevalence is a better predictor of exploratory behavior than the other two factors. A simple computational model in which exploration decisions were based on small samples of past experiences captured the empirical phenomena while also providing a cognitive basis for feelings of uncontrollability. © The Author(s) 2014.

Implicit and Explicit Attitudes Predict Smoking Cessation: Moderating Effects of Experienced Failure to Control Smoking and Plans to Quit

PubMed Central

Chassin, Laurie; Presson, Clark C.; Sherman, Steven J.; Seo, Dong-Chul; Macy, Jon

2010-01-01

The current study tested implicit and explicit attitudes as prospective predictors of smoking cessation in a Midwestern community sample of smokers. Results showed that the effects of attitudes significantly varied with levels of experienced failure to control smoking and plans to quit. Explicit attitudes significantly predicted later cessation among those with low (but not high or average) levels of experienced failure to control smoking. Conversely, however, implicit attitudes significantly predicted later cessation among those with high levels of experienced failure to control smoking, but only if they had a plan to quit. Because smoking cessation involves both controlled and automatic processes, interventions may need to consider attitude change interventions that focus on both implicit and explicit attitudes. PMID:21198227

Modeling and control parameters for GMAW, short-circuiting transfer

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

Cook, G.E.; DeLapp, D.R.; Barnett, R.J.

1996-12-31

Digital signal processing was used to analyze the electrical arc signals of the gas metal arc welding process with short-circuiting transfer. Among the features extracted were arc voltage and current (both average and peak values), short-circuiting frequency, arc period, shorting period, and the ratio of the arcing to shorting period. Additionally , a Joule heating model was derived which accurately predicted the melt-back distance during each short. The short-circuiting frequency, the ratio of the arc period to short periods, and the melt-back distance were found to be good indicators for monitoring and control of stable arc conditions.

Proceedings of the Annual Frequency Control Symposium (31st) Held at Atlantic City, New Jersey on 1-3 June 1977.

DTIC Science & Technology

1977-01-01

Frequency Control , pp. 1-4, eyT75. considered representative of the crystal. 5 J. Kusters and J. Leach, "Further Experimental Data Long term aging has also...earlier. The solid f_ curves represent experimental results averaged over a group of units, and also over a number of runs on each 0 0 24.5 90 -11.5...was determined by picking four from each experimental As a result, our current pr3ctice is to design for group that were the closest in turnover

Counterintuitive effects of substrate roughness on PDCs

NASA Astrophysics Data System (ADS)

Andrews, B. J.; Manga, M.

2012-12-01

We model dilute pyroclastic density currents (PDCs) using scaled, warm, particle-laden density currents in a 6 m long, 0.6 m wide, 1.8 m tall air-filled tank. In this set of experiments, we run currents over substrates with characteristic roughness scales, hr, ranging over ~3 orders of magnitude from smooth, through 250 μm sandpaper, 0.1-, 1-, 2-, 5-, and 10 cm hemispheres. As substrate roughness increases, runout distance increases until a critical roughness height, hrc, is reached; further increases in roughness height decrease runout. The critical roughness height appears to be 0.25-0.5 htb, the thickness of the turbulent lower layer of the density currents. The dependence of runout on hr is most likely the result of increases in substrate roughness decreasing the average current velocity and converting that energy into increased turbulence intensity. Small values of hr thus result in increased runout as sedimentation is inhibited by the increased turbulence intensity. At larger values of hr current behavior is controlled by much larger decreases in average current velocity, even though sedimentation decreases. Scaling our experiments up to the size of real volcanic eruptions suggests that landscapes must have characteristic roughness hr>10 m to reduce the runout of natural PDCs, smaller roughness scales can increase runout. Comparison of relevant bulk (Reynolds number, densimetric and thermal Richardson numbers, excess buoyant thermal energy density) and turbulent (Stokes and settling numbers) between our experiments and natural dilute PDCs indicates that we are accurately modeling at least the large scale behaviors and dynamics of dilute PDCs.

Quantifying the economic burden of malaria in Nigeria using the willingness to pay approach

PubMed Central

Jimoh, Ayodele; Sofola, Oluyemi; Petu, Amos; Okorosobo, Tuoyo

2007-01-01

Background Malaria illness imposes great burden on the society as it has adverse effects on the physical, mental and social well being of the people as well as on the economic development of the nation. Methods The study uses the Willingness To Pay (WTP) approach to evaluate the burden of malaria in Nigeria. Results The results indicate that households would be prepared to pay an average of about Naira 1,112 (USD 9.3) per month for the treatment of malaria. This is about Naira 427 (USD 3.6) in excess of the average expenditure they currently make on malaria treatment per month. Similarly, households are willing to pay on the average a sum of Naira 7,324 (USD 61) per month for the control of malaria. Again, this is an excess of about Naira 2,715 (USD 22.6) over the cost they currently bear (protection, treatment and indirect costs), and it represents households' average valuation of their intangible costs of malaria illness. This amount represents about Naira 611.7 (USD 5.1) per head per month and Naira 7,340 (USD 61.2) per year. For a country with a population of about 120 million this translates to about Naira 880,801 million per annum representing about 12.0 per cent of Gross Domestic Product. Hence, the malaria burden in Nigeria is enormous and has a devastating impact on economic growth. Conclusion In the long term, it is important to recognize that health and poverty are closely linked. Reducing the burden of malaria in Nigeria will help to contribute to the economic well-being of communities; and poverty-reduction will be an essential input into improving health. National malaria control programme in Nigeria and their partners need to recognize these links, and identify mechanisms for ensuring that the poorest have access to essential health interventions. PMID:17517146

Costs of current antihypertensive therapy in Switzerland: an economic evaluation of 3,489 patients in primary care.

PubMed

Schäfer, Hans Hendrik; Scheunert, Uta

2013-10-25

Due to greater life expectancy, costs of medication have increased within the last decade. This investigation assesses health care expenditures needed to manage the current state of blood pressure (BP) control in Switzerland. a) average day therapy costs (DTC) of substances, b) actual DTC of currently prescribed antihypertensive therapy, c) monetary differences of treatment regimens within different BP-groups and different high risk patients, d) estimated compliance-related financial loss/annum and adjusted costs/annum. Single-pill-combinations appear to be useful to increase patient's compliance, to reduce side effects and to bring more patients to their blood pressure goal. Costs were identified based on data from the Swiss department of health. We calculated DTC for each patient using prices of the largest available tablet box. The average antihypertensive therapy in Switzerland currently costs CHF 1.198 ± 0.732 per day. On average beta blockers were the cheapest substances, followed by angiotensin converting enzyme inhibitors (ARBs), calcium channel blockers and diuretics. The widest price ranges were observed within the class of ARBs. Most expensive were patients with impaired renal function. Throughout all stages, single-pill-combinations appeared to be significantly cheaper than dual-free-combinations. Stage-II-hypertension yielded the highest costs for dual free combination drug use. The actual costs for all patients observed in this analysis added up to CHF 1,525,962. Based on a compliance model, only treatment amounting to CHF 921,353 is expected to be actually taken. A disproportionately high healthcare cost is expected due to compliance reasons. The prescription of mono-therapies appears to be a major cost factor, thus, the use of single-pill-combination therapy can be considered as a suitable approach to saving costs throughout all BP- stages.

Houston, We Have a Problem Solving Model for Training

NASA Technical Reports Server (NTRS)

Schmidt, Lacey; Slack, Kelley; Keeton, Kathryn; Barshi, Immanuel; Martin, Lynne; Mauro, Robert; O'Keefe, William; Baldwin, Evelyn; Huning, Therese

2011-01-01

In late 2006, the Mission Operations Directorate (MOD) at NASA began looking at ways to make training more efficient for the flight controllers who support the International Space Station. The average certification times for flight controllers spanned from 18 months to three years and the MOD, responsible for technical training, was eager to develop creative solutions that would reduce the time to 12 months. Additionally, previously trained flight controllers sometimes participated in more than 50 very costly, eight-hour integrated simulations before becoming certified. New trainees needed to gain proficiency with far fewer lessons and training simulations than their predecessors. This poster presentation reviews the approach and the process that is currently in development to accomplish this goal.

Role of RIS/APC for manufacturing RFG/LSD. [Refinery Information Systems/Advanced Process Control, ReFormulated Gasoline/Low Sulfur Diesels

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

Latour, P.R.

Revolutionary changes in quality specifications (number, complexity, uncertainty, economic sensitivity) for reformulated gasolines (RFG) and low-sulfur diesels (LSD) are being addressed by powerful, new, computer-integrated manufacturing technology for Refinery Information Systems and Advanced Process Control (RIS/APC). This paper shows how the five active RIS/APC functions: performance measurement, optimization, scheduling, control and integration are used to manufacture new, clean fuels competitively. With current industry spending for this field averaging 2 to 3 cents/bbl crude, many refineries can capture 50 to 100 cents/bbl if the technology is properly employed and sustained throughout refining operations, organizations, and businesses.

[Metabolic control in children and adolescents with type 1 diabetes].

PubMed

Díaz-Cárdenas, Claudia; Wong, Carolina; Vargas Catalán, Nelson A

2016-01-01

Type 1 diabetes mellitus (T1D) is an important disease in children and adolescent being a major risk factor for early morbidity and mortality. To know the degree of metabolic control and prevalence of cardiovascular risk factors in T1D patients. Retrospective study including patients under 19 years of age with T1D controlled at a Chilean hospital in 2011. 94 patients were evaluated (average age at diagnosis: 7.3 years; current age: 11,9 years; evolution time: 4.5 years). Seventy-nine percent (79.8%) of patients presented glycated hemoglobin (HbA1c) over the recommended level with an average of 8.9%. The group between 13 and 19 years of age exhibited the worst metabolic control (86% with HbA1c abnormal levels). Overweight or obesity occurred in 26.6% of patients, 20.3% had LDL >100mg/dl and 4.2% had hypertension. Only about twenty percent of patients had adequate metabolic control as measured by HbA1c, although cardiovascular risk profile was acceptable. Therapeutic and educational efforts must be reinforced mainly in adolescents, emphasizing the importance of adequate nutritional management as a primary method to treat this entity. Copyright © 2015 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Flow-driven pattern formation in the calcium-oxalate system.

PubMed

Bohner, Bíborka; Endrődi, Balázs; Horváth, Dezső; Tóth, Ágota

2016-04-28

The precipitation reaction of calcium oxalate is studied experimentally in the presence of spatial gradients by controlled flow of calcium into oxalate solution. The density difference between the reactants leads to strong convection in the form of a gravity current that drives the spatiotemporal pattern formation. The phase diagram of the system is constructed, the evolving precipitate patterns are analyzed and quantitatively characterized by their diameters and the average height of the gravity flow. The compact structures of calcium oxalate monohydrate produced at low flow rates are replaced by the thermodynamically unstable calcium oxalate dihydrate favored in the presence of a strong gravity current.

A complete dc characterization of a constant-frequency, clamped-mode, series-resonant converter

NASA Technical Reports Server (NTRS)

Tsai, Fu-Sheng; Lee, Fred C.

1988-01-01

The dc behavior of a clamped-mode series-resonant converter is characterized systematically. Given a circuit operating condition, the converter's mode of operation is determined and various circuit parameters are calculated, such as average inductor current (load current), rms inductor current, peak capacitor voltage, rms switch currents, average diode currents, switch turn-on currents, and switch turn-off currents. Regions of operation are defined, and various circuit characteristics are derived to facilitate the converter design.

Control algorithms for dynamic attenuators

PubMed Central

Hsieh, Scott S.; Pelc, Norbert J.

2014-01-01

Purpose: The authors describe algorithms to control dynamic attenuators in CT and compare their performance using simulated scans. Dynamic attenuators are prepatient beam shaping filters that modulate the distribution of x-ray fluence incident on the patient on a view-by-view basis. These attenuators can reduce dose while improving key image quality metrics such as peak or mean variance. In each view, the attenuator presents several degrees of freedom which may be individually adjusted. The total number of degrees of freedom across all views is very large, making many optimization techniques impractical. The authors develop a theory for optimally controlling these attenuators. Special attention is paid to a theoretically perfect attenuator which controls the fluence for each ray individually, but the authors also investigate and compare three other, practical attenuator designs which have been previously proposed: the piecewise-linear attenuator, the translating attenuator, and the double wedge attenuator. Methods: The authors pose and solve the optimization problems of minimizing the mean and peak variance subject to a fixed dose limit. For a perfect attenuator and mean variance minimization, this problem can be solved in simple, closed form. For other attenuator designs, the problem can be decomposed into separate problems for each view to greatly reduce the computational complexity. Peak variance minimization can be approximately solved using iterated, weighted mean variance (WMV) minimization. Also, the authors develop heuristics for the perfect and piecewise-linear attenuators which do not require a priori knowledge of the patient anatomy. The authors compare these control algorithms on different types of dynamic attenuators using simulated raw data from forward projected DICOM files of a thorax and an abdomen. Results: The translating and double wedge attenuators reduce dose by an average of 30% relative to current techniques (bowtie filter with tube current modulation) without increasing peak variance. The 15-element piecewise-linear dynamic attenuator reduces dose by an average of 42%, and the perfect attenuator reduces dose by an average of 50%. Improvements in peak variance are several times larger than improvements in mean variance. Heuristic control eliminates the need for a prescan. For the piecewise-linear attenuator, the cost of heuristic control is an increase in dose of 9%. The proposed iterated WMV minimization produces results that are within a few percent of the true solution. Conclusions: Dynamic attenuators show potential for significant dose reduction. A wide class of dynamic attenuators can be accurately controlled using the described methods. PMID:24877818

Depth-averaged instantaneous currents in a tidally dominated shelf sea from glider observations

NASA Astrophysics Data System (ADS)

Merckelbach, Lucas

2016-12-01

Ocean gliders have become ubiquitous observation platforms in the ocean in recent years. They are also increasingly used in coastal environments. The coastal observatory system COSYNA has pioneered the use of gliders in the North Sea, a shallow tidally energetic shelf sea. For operational reasons, the gliders operated in the North Sea are programmed to resurface every 3-5 h. The glider's dead-reckoning algorithm yields depth-averaged currents, averaged in time over each subsurface interval. Under operational conditions these averaged currents are a poor approximation of the instantaneous tidal current. In this work an algorithm is developed that estimates the instantaneous current (tidal and residual) from glider observations only. The algorithm uses a first-order Butterworth low pass filter to estimate the residual current component, and a Kalman filter based on the linear shallow water equations for the tidal component. A comparison of data from a glider experiment with current data from an acoustic Doppler current profilers deployed nearby shows that the standard deviations for the east and north current components are better than 7 cm s-1 in near-real-time mode and improve to better than 6 cm s-1 in delayed mode, where the filters can be run forward and backward. In the near-real-time mode the algorithm provides estimates of the currents that the glider is expected to encounter during its next few dives. Combined with a behavioural and dynamic model of the glider, this yields predicted trajectories, the information of which is incorporated in warning messages issued to ships by the (German) authorities. In delayed mode the algorithm produces useful estimates of the depth-averaged currents, which can be used in (process-based) analyses in case no other source of measured current information is available.

Alternating-pulse iontophoresis for targeted cutaneous anesthesia

NASA Technical Reports Server (NTRS)

Meyer, Peter F.; Oddsson, Lars I E.

2003-01-01

In studies of sensory contributions to motor control, it may be advantageous to temporarily reduce the sensitivity of specific sensory systems. This article details a method for non-invasively inducing cutaneous anesthesia, leaving proprioceptive and motor functions intact. This method, called alternating-pulse iontophoresis, differs from conventional direct-current (DC) iontophoretic drug delivery in that adjacent drug delivery electrodes are stimulated out-of-phase. The total current delivered at any instant is then less than that produced during a comparable DC application, while the uniformity of drug delivery is expected to improve. Effective delivery of local anesthetics to the cutaneous foot soles by alternating-pulse iontophoresis was demonstrated using cutaneous pressure sensory threshold levels (STL's) assessed with Semmes-Weinstein monofilaments (arbitrary units of perceived force, or a.u.). Thirteen of 16 healthy subjects achieved a level of anesthesia greater than or equal to that normally associated with clinical peripheral sensory neuropathy. Average STL's measured prior to the anesthesia procedure were 4.00 a.u. ( approximately 10 mN). Immediately following the procedure, STL's were elevated to an average of 5.40 a.u. ( approximately 246 mN) and averaged 4.97 a.u. ( approximately 92 mN) after 50 min of standing. A number of research and clinical applications for this technique are suggested.

Evaluation of phosphine genotoxicity at occupational levels of exposure in New South Wales, Australia.

PubMed Central

Barbosa, A; Bonin, A M

1994-01-01

Phosphine has been claimed to cause chromosomal damage at exposures close to the current time weighted average exposure standard of 0.3 ppm (0.4 mg/m3). The current study involved 31 phosphine fumigators and 21 controls during the high fumigation season. All were volunteers and were evaluated for genotoxicity variables, including micronuclei in peripheral blood lymphocytes and urine mutagenicity. In parallel, all fumigators and 17 controls were evaluated for full haematology, multiple biochemical analysis, whole blood organochlorines, and whole blood and serum cholinesterase activity. The results for micronuclei showed no significant differences between fumigators and controls, but detected a strong association between age and increased frequency of micronuclei. Measurement of urine mutagenicity did not show any significant difference between fumigators and controls, but did show increased excretion of mutagens in smokers. All haematological and biochemical variables were within normal ranges, except for some non-specific changes in biochemistry. At monitored occupational exposures of < 2.4 ppm/h our results show no association between phosphine exposure and genotoxic or toxicological effects in fumigators. PMID:8000496

Mammographic compression after breast conserving therapy: Controlling pressure instead of force

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

Groot, J. E. de, E-mail: jerry.degroot@sigmascreening.com; Branderhorst, W.; Grimbergen, C. A.

Purpose: X-ray mammography is the primary tool for early detection of breast cancer and for follow-up after breast conserving therapy (BCT). BCT-treated breasts are smaller, less elastic, and more sensitive to pain. Instead of the current force-controlled approach of applying the same force to each breast, pressure-controlled protocols aim to improve standardization in terms of physiology by taking breast contact area and inelasticity into account. The purpose of this study is to estimate the potential for pressure protocols to reduce discomfort and pain, particularly the number of severe pain complaints for BCT-treated breasts. Methods: A prospective observational study including 58more » women having one BCT-treated breast and one untreated nonsymptomatic breast, following our hospital's 18 decanewton (daN) compression protocol was performed. Breast thickness, applied force, contact area, mean pressure, breast volume, and inelasticity (mean E-modulus) were statistically compared between the within-women breast pairs, and data were used as predictors for severe pain, i.e., scores 7 and higher on an 11-point Numerical Rating Scale. Curve-fitting models were used to estimate how pressure-controlled protocols affect breast thickness, compression force, and pain experience. Results: BCT-treated breasts had on average 27% smaller contact areas, 30% lower elasticity, and 30% higher pain scores than untreated breasts (allp < 0.001). Contact area was the strongest predictor for severe pain (p < 0.01). Since BCT-treatment is associated with an average 0.36 dm{sup 2} decrease in contact area, as well as increased pain sensitivity, BCT-breasts had on average 5.3 times higher odds for severe pain than untreated breasts. Model estimations for a pressure-controlled protocol with a 10 kPa target pressure, which is below normal arterial pressure, suggest an average 26% (range 10%–36%) reduction in pain score, and an average 77% (range 46%–95%) reduction of the odds for severe pain. The estimated increase in thickness is +6.4% for BCT breasts. Conclusions: After BCT, women have hardly any choice in avoiding an annual follow-up mammogram. Model estimations show that a 10 kPa pressure-controlled protocol has the potential to reduce pain and severe pain particularly for these women. The results highly motivate conducting further research in larger subject groups.« less

Development and Validation of EPH Material Model for Engineered Roadway Soil

DTIC Science & Technology

2014-08-01

MODEL FOR ENGINEERED ROADWAY SOIL Ching Hsieh, PhD Altair Engineering Troy, MI Jianping Sheng, Ph.D. Jai Ramalingam System Engineering...0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing...of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 11 AUG 2014 2. REPORT TYPE Journal Article 3. DATES

ME 5620 Fracture Mechanics in Engineering Design. Case Study Project

DTIC Science & Technology

2011-04-03

14 UNCLASSIFIED References 1 . A First Course in the Finite Element Method, 4th edition, by D.L. Logan, Thomson Engineering, 2006. 2. Altair ...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources...currently valid OMB control number. 1 . REPORT DATE 03 APR 2011 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Case Study

The 2 SOPS Ephemeris Enhancement Endeavor (EEE)

DTIC Science & Technology

1997-12-01

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Validation Test Report for WAVEWATCH III

DTIC Science & Technology

2012-11-30

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Assessment of Multiple Scattering Errors of Laser Diffraction Instruments

DTIC Science & Technology

2003-03-17

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Technology and RDT&E - An ARMY Perspective

DTIC Science & Technology

2011-07-01

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Development of a Tetrathioether (S4) Bifunctional Chelate System for Rh-105

DTIC Science & Technology

2013-07-01

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Development of a Tetrathioether (S4) Bifunctional Chelate System for Rh-105

DTIC Science & Technology

2013-06-01

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The Bush Doctrine: Power Concepts, Preemption and the Global War on Terror

DTIC Science & Technology

2004-03-19

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Supply Chain Management/Strategic Acquisition: The Case for Professional Pay in the Army Acquisition Corps

DTIC Science & Technology

2012-04-01

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Development of Environmentally Friendly Insensitive Pyrotechnic Munitions with Enhanced Battlefield Performance

DTIC Science & Technology

2011-11-30

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Experiments and Simulations of Exploding Aluminum Wires: Validation of ALEGRA-MHD

DTIC Science & Technology

2010-09-01

ii REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) September 2010 2. REPORT TYPE Final...List of Tables vi Acknowledgements vii 1 . Introduction 1 2. Experimental Setup 2 3. Computational Setup 5 3.1 Description of ALEGRA

Chemomechanics with Molecular Force Probes

DTIC Science & Technology

2010-03-30

at scales >50 nm) [ 1 –5]. Such coupling affects the rate at which the chemical reaction occurs and therefore must be accounted for in any kinetic...reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching...it does not display a currently valid OMB control number. 1 . REPORT DATE 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4

Water Column Variability in Coastal Regions

DTIC Science & Technology

1999-09-30

0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing...collection of information if it does not display a currently valid OMB control number 1 . REPORT DATE 30 SEP 1999 2. REPORT TYPE 3. DATES COVERED...images were used to detect and characterize the front between waters of the Bay and those of the Sound. Figure 1 illustrates the type of SST

Modeling micro-droplet formation in near-field electrohydrodynamic jet printing

NASA Astrophysics Data System (ADS)

Popell, George Colin

Near-field electrohydrodynamic jet (E-jet) printing has recently gained significant interest within the manufacturing research community because of its ability to produce micro/sub-micron-scale droplets using a wide variety of inks and substrates. However, the process currently operates in open-loop and as a result suffers from unpredictable printing quality. The use of physics-based, control-oriented process models is expected to enable closed-loop control of this printing technique. The objective of this research is to perform a fundamental study of the substrate-side droplet shape-evolution in near-field E-jet printing and to develop a physics-based model of the same that links input parameters such as voltage magnitude and ink properties to the height and diameter of the printed droplet. In order to achieve this objective, a synchronized high-speed imaging and substrate-side current-detection system was used implemented to enable a correlation between the droplet shape parameters and the measured current signal. The experimental data reveals characteristic process signatures and droplet spreading regimes. The results of these studies are then used as the basis for a model that predicts the droplet diameter and height using the measured current signal as the input. A unique scaling factor based on the measured current signal is used in this model instead of relying on empirical scaling laws found in literature. For each of the three inks tested in this study, the average absolute error in the model predictions is under 4.6% for diameter predictions and under 10.6% for height predictions of the steady-state droplet. While printing under non-conducive ambient conditions of low humidity and high temperatures, the use of the environmental correction factor in the model is seen to result in average absolute errors of 10.35% and 12.5% for diameter and height predictions.

Mental disorders in current and former heavy ecstasy (MDMA) users.

PubMed

Thomasius, R; Petersen, K U; Zapletalova, P; Wartberg, L; Zeichner, D; Schmoldt, A

2005-09-01

Ecstasy use has often been found to be associated with psychopathology, yet this research has so far been based largely on subjective symptom ratings. To investigate whether ecstasy users suffered from long-term psychopathological consequences. We compared the prevalence of Diagnostic and Statistical Manual version IV (DSM-IV) mental disorders in 30 current and 29 former ecstasy users, 29 polydrug and 30 drug-naive controls. Groups were approximately matched by age, gender and level of education. The current ecstasy users reported a life-time dose of an average of 821 and the former ecstasy users of 768 ecstasy tablets. Ecstasy users did not significantly differ from controls in the prevalence of mental disorders, except those related to substance use. Substance-induced affective, anxiety and cognitive disorders occurred more frequently among ecstasy users than polydrug controls. The life-time prevalence of ecstasy dependence amounted to 73% in the ecstasy user groups. More than half of the former ecstasy users and nearly half of the current ecstasy users met the criteria of substance-induced cognitive disorders at the time of testing. Logistic regression analyses showed the estimated life-time doses of ecstasy to be predictive of cognitive disorders, both current and life-time. The motivation for ecstasy use is not likely to be self-medication of pre-existing depressive or anxiety disorders as these did not occur more frequently in the ecstasy users than in control groups or in the general population. Cognitive disorders still present after over 5 months of ecstasy abstinence may well be functional consequences of serotonergic neurotoxicity of 3,4-methylenedioxymethamphetamine (MDMA).

Familial risk for lifestyle-related chronic diseases: can family health history be used as a motivational tool to promote health behaviour in young adults?

PubMed

Prichard, I; Lee, A; Hutchinson, A D; Wilson, C

2015-08-01

Risk for colorectal cancer, breast cancer, heart disease and diabetes has both a familial and a lifestyle component. This quasi-experimental study aimed to determine whether a Family Health History (FHH) assessment and the subsequent provision of risk information would increase young adults' (17-29 years) intentions to modify health behaviours associated with the risk of these chronic diseases (i.e. alcohol consumption, fruit and vegetable intake and physical activity) and to talk to their family about their risk. After baseline measures of current and intended health-related behaviours, participants (n = 116) were randomly allocated to either a FHH assessment or control information. Based on the FHH provided, participants in the FHH condition were then classified as 'above-average risk' or 'average risk'. One week later, participants were provided with tailored health information and completed follow-up measures of intended health-related behaviours and perceived vulnerability. Participants classified as 'above-average risk' had increased perceptions of vulnerability to a chronic disease. Despite this, no group differences were found in intentions to change physical activity or fruit and vegetable consumption. Participants with above-average risk reported greater intentions to decrease the frequency of their alcohol consumption than average risk/control participants. In addition, completing a FHH assessment promoted intended communication with family members about chronic disease risk. FHH assessments may have the greatest value within the family context. SO WHAT? Future research could examine the impact of providing FHH information to different family members as a health promotion strategy.

Effects of current on droplet generation and arc plasma in gas metal arc welding

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

Hu, J.; Tsai, H. L.

2006-09-01

In gas metal arc welding (GMAW), a technology using pulsed currents has been employed to achieve the one-droplet-per-pulse (ODPP) metal transfer mode with the advantages of low average currents, a stable and controllable droplet generation, and reduced spatter. In this paper, a comprehensive model was developed to study the effects of different current profiles on the droplet formation, plasma generation, metal transfer, and weld pool dynamics in GMAW. Five types of welding currents were studied, including two constant currents and three wave form currents. In each type, the transient temperature and velocity distributions of the arc plasma and the moltenmore » metal, and the shapes of the droplet and the weld pool were calculated. The results showed that a higher current generates smaller droplets, higher droplet frequency, and higher electromagnetic force that becomes the dominant factor detaching the droplet from the electrode tip. The model has demonstrated that a stable ODPP metal transfer mode can be achieved by choosing a current with proper wave form for given welding conditions.« less

Socioeconomic Disparities in Fatalistic Beliefs About Cancer Prevention and the Internet

PubMed Central

Lee, Chul-joo; Niederdeppe, Jeff; Freres, Derek

2014-01-01

Given the importance of public information environment in cancer control, it is theoretically and practically important to explore how people's media use to acquire health information influences their beliefs about cancer prevention. In the current research, we focus on the role of the Internet in shaping fatalistic beliefs about cancer prevention (cancer fatalism). To be more specific, we examine the effect of Internet use for health information on changes in cancer fatalism using a 2-wave nationally representative survey. We then investigate whether the effect of Internet use on cancer fatalism is moderated by education and health knowledge. Health-related Internet use reduced cancer fatalism only among those with average and lower than the average levels of education and health knowledge. PMID:25530627

Fluoride in drinking water and risk of hip fracture in the UK: a case-control study.

PubMed

Hillier, S; Cooper, C; Kellingray, S; Russell, G; Hughes, H; Coggon, D

2000-01-22

Although the benefits of water fluoridation for dental health are widely accepted, concerns remain about possible adverse effects, particularly effects on bone. Several investigators have suggested increased rates of hip fracture in places with high concentrations of fluoride in drinking water, but this finding has not been consistent, possibly because of unrecognised confounding effects. We did a case-control study of men and women aged 50 years and older from the English county of Cleveland, and compared patients with hip fracture with community controls. Current addresses were ascertained for all participants; for those who agreed to an interview and who passed a mental test, more detailed information was obtained about lifetime residential history and exposure to other known and suspected risk factors for hip fracture. Exposures to fluoride in water were estimated from the residential histories and from information provided by water suppliers. Analysis was by logistic regression. 914 cases and 1196 controls were identified, of whom 514 and 527, respectively, were interviewed. Among those interviewed, hip fracture was strongly associated with low body-mass index (p for trend <0.001) and physical inactivity (p for trend <0.001). Estimated average lifetime exposure to fluoride in drinking water ranged from 0.15 to 1.79 ppm. Current residence in Hartlepool was a good indicator for high lifetime exposure to fluoride. After adjustment for potential confounders, the odds ratio associated with an average lifetime exposure to fluoride > or =0.9 ppm was 1.0 [95% CI 0.7-1.5]. There is a low risk of hip fracture for people ingesting fluoride in drinking water at concentrations of about 1 ppm. This low risk should not be a reason for withholding fluoridation of water supplies.

Appropriateness of selecting different averaging times for modelling chronic and acute exposure to environmental odours

NASA Astrophysics Data System (ADS)

Drew, G. H.; Smith, R.; Gerard, V.; Burge, C.; Lowe, M.; Kinnersley, R.; Sneath, R.; Longhurst, P. J.

Odour emissions are episodic, characterised by periods of high emission rates, interspersed with periods of low emissions. It is frequently the short term, high concentration peaks that result in annoyance in the surrounding population. Dispersion modelling is accepted as a useful tool for odour impact assessment, and two approaches can be adopted. The first approach of modelling the hourly average concentration can underestimate total odour concentration peaks, resulting in annoyance and complaints. The second modelling approach involves the use of short averaging times. This study assesses the appropriateness of using different averaging times to model the dispersion of odour from a landfill site. We also examine perception of odour in the community in conjunction with the modelled odour dispersal, by using community monitors to record incidents of odour. The results show that with the shorter averaging times, the modelled pattern of dispersal reflects the pattern of observed odour incidents recorded in the community monitoring database, with the modelled odour dispersing further in a north easterly direction. Therefore, the current regulatory method of dispersion modelling, using hourly averaging times, is less successful at capturing peak concentrations, and does not capture the pattern of odour emission as indicated by the community monitoring database. The use of short averaging times is therefore of greater value in predicting the likely nuisance impact of an odour source and in framing appropriate regulatory controls.

Configuring Airspace Sectors with Approximate Dynamic Programming

NASA Technical Reports Server (NTRS)

Bloem, Michael; Gupta, Pramod

2010-01-01

In response to changing traffic and staffing conditions, supervisors dynamically configure airspace sectors by assigning them to control positions. A finite horizon airspace sector configuration problem models this supervisor decision. The problem is to select an airspace configuration at each time step while considering a workload cost, a reconfiguration cost, and a constraint on the number of control positions at each time step. Three algorithms for this problem are proposed and evaluated: a myopic heuristic, an exact dynamic programming algorithm, and a rollouts approximate dynamic programming algorithm. On problem instances from current operations with only dozens of possible configurations, an exact dynamic programming solution gives the optimal cost value. The rollouts algorithm achieves costs within 2% of optimal for these instances, on average. For larger problem instances that are representative of future operations and have thousands of possible configurations, excessive computation time prohibits the use of exact dynamic programming. On such problem instances, the rollouts algorithm reduces the cost achieved by the heuristic by more than 15% on average with an acceptable computation time.

[Evaluation of effect of prevention and control system for imported falciparum malaria in Hanjiang District].

PubMed

She, Guo-lin; Ma, Yu-Cai; Wang, Fu-biao

2013-08-01

To analyze the current situation of the comprehensive prevention and control system for imported falciparum malaria in Hanjiang District and evaluate its effect. According to the Management Scheme on Control of Imported Falciparum Malaria in Yangzhou City, the comprehensive prevention and control system for imported falciparum malaria was implemented, and the relevant malaria data were collected and analyzed statistically. The data included plasmodium blood test ratio of fever patients among exported labors and those returned, the ratio of laboratory-confirmed cases among all reported cases of falciparum malaria, the ratio of falciparum malaria patients who received the standard treatment within 24 hours after onset, etc from 2010 to 2012. After the implementation of the comprehensive prevention and control system, the confirmation ratio of falciparum malaria cases within 24 hours following first visit has reached 60.47%, the average time from first visit to confirmation has shortened to 1.8 d, and the average time from onset to confirmation has shortened to 3.7 d. The health education coverage ratio was 100%, the health knowledge awareness ratio was 95.56%, the ratio of patients seeking treatment on own initiative was 100%, the laboratory-confirmed ratio was 100%, and the ratio of standard treatment after malaria diagnosis was 100%. The comprehensive prevention and control system carried out by Hanjiang District has made remarkable achievements.

Conflict control of children with different intellectual levels: an ERP study.

PubMed

Liu, Tongran; Xiao, Tong; Shi, Jiannong; Zhao, Daheng; Liu, Jizhong

2011-02-25

Conflict control is an important cognitive ability in human behavioral regulation. The Eriksen flanker task was employed to explore the neural correlation between conflict control and intelligence with the aid of event-related potential (ERP) techniques. Two groups of early adolescents with different intellectual levels participated in the current study (an intellectually gifted group of 20 children vs. an intellectually average group of 21 children, with mean scores of 43 vs. 35.7 in Cattell's Culture Fair Test, respectively). Behavioral results indicate that the gifted children had better conflict control performances, with increased accuracy and faster response speeds than the intellectually average children. Electrophysiological results further show that the gifted children had more efficient N2 activations during conflict monitoring processing, faster P3 responses over frontal regions, and stronger P3 activations over central-parietal regions during attentional control processing. The difference waveform analysis showed that the gifted children had the weakest N2d activations when elicited by multiple conflicts. N2d amplitudes can be used to distinguish a stimulus conflict from a response conflict, and P3d amplitudes can be used to separate multiple conflicts from a single conflict. The results support the neural efficiency hypothesis of intelligence and shed light on the close relationship between conflict control ability and human intelligence. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Applying Space Technology to Enhance Control of an Artificial Arm for Children and Adults With Amputations

NASA Technical Reports Server (NTRS)

Atkins, Diane J.

1998-01-01

The first single function myoelectric prosthetic hand was introduced in the 1960's. This hand was controlled by the electric fields generated by muscle contractions in the residual limb of the amputee user. Electrodes and amplifiers, embedded in the prosthetic socket, measured these electric fields across the skin, which increase in amplitude as the individual contracts their muscle. When the myoelectric signal reached a certain threshold amplitude, the control unit activated a motor which opened or closed a hand-like prosthetic terminal device with a pincher grip. Late in the 1990's, little has changed. Most current myoelectric prostheses still operate in this same, single-function way. To better understand the limitations of the current single-function myoelectric hand and the needs of those who use them, The Institute for Rehabilitation and Research (TIRR), sponsored by the National Institutes of Health (NUH), surveyed approximately 2,500 individuals with upper limb loss [1]. When asked to identify specific features of their current myoelectric prostheses that needed improvement, the survey respondents overwhelmingly identified the lack of wrist and finger movement, as well as poor control capability. However, simply building a mechanism with individual finger and wrist motion is not enough. In the 1960's and 1970's, engineers built a number of more dexterous prosthetic hands. Unfortunately, these were rejected during clinical trials due to a difficult and distracting control interface. The goal of this project, "Applying Space Technology to Enhance Control of an Artificial Arm for Children and Adults with Amputations," was to lay the foundation for a multi-function, intuitive myoelectric control system which requires no conscious thought to move the hand. We built an extensive myoelectric signal database for six motions from ten amputee volunteers, We also tested a control system based on new artificial intelligence techniques on the data from two of these subjects. This data is available to anyone doing myoelectric control research. Its availability is an important contribution to the prosthetics research community, as many researchers do not have access to amputee subjects. Since we collected myoelectric data from subjects' sound arms as well as their residual arms, this database will also prove useful to virtual reality and robotics researchers who want to explore myoelectric-based interfaces between any user and a machine. Currently, one small company (Intelligenta, Inc.) and one university (University of New Brunswick, Canada) are using this myoelectric database under other funding to develop multifunction control systems for prostheses. A prosthetics manufacturer (Liberty Technology, Inc.) is making plans to incorporate the results of their work into an artificial hand capable of several different movements to provide functionality only dreamed of by current myoelectric users. Methods Six adults and four children, all with unilateral, below-elbow amputations served as subjects. Five of the adults (3 male, 2 female, average age 34 years) had amputations due to traumatic injury, while one adult (female, age 32 years) and the four children (3 male, 1 female, average age 13 years) had congenital (i.e. from birth) limb deficiencies.

Implicit and explicit attitudes predict smoking cessation: moderating effects of experienced failure to control smoking and plans to quit.

PubMed

Chassin, Laurie; Presson, Clark C; Sherman, Steven J; Seo, Dong-Chul; Macy, Jonathan T

2010-12-01

The current study tested implicit and explicit attitudes as prospective predictors of smoking cessation in a Midwestern community sample of smokers. Results showed that the effects of attitudes significantly varied with levels of experienced failure to control smoking and plans to quit. Explicit attitudes significantly predicted later cessation among those with low (but not high or average) levels of experienced failure to control smoking. Conversely, however, implicit attitudes significantly predicted later cessation among those with high levels of experienced failure to control smoking, but only if they had a plan to quit. Because smoking cessation involves both controlled and automatic processes, interventions may need to consider attitude change interventions that focus on both implicit and explicit attitudes. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Electromagnetic processes during phase commutation in field regulated reluctance machine

NASA Astrophysics Data System (ADS)

Shishkov, A. N.; Sychev, D. A.; Zemlyansky, A. A.; Krupnova, M. N.; Funk, T. A.; Ishmet'eva, V. D.

2018-03-01

The processes of currents switching in stator windings have been explained by the existence of the electromagnetic torque ripples in the electric drive with the field-regulated reluctance machine. The maximum value of ripples in the open loop control system for the six-phase machine can reach 20 percent from the developed electromagnetic torque. This method allows one to make calculation of ripple spike towards average torque developed by the electromotor for the different number of phases. Application of a trapezoidal form of current at six phases became the solution. In case of a less number of phases than six, a ripple spike considerably increases, which is inadmissible. On the other hand, increasing the number of phases tends to the increase of the semiconductor inverter external dimensions based on the inconspicuous decreasing of a ripple spike. The creation and usage of high-speed control loops of current (HCLC) have been recommended for a reduction of the electromagnetic torque’s ripple level, as well as the appliance of positive current feedback in switching phase currents. This decision allowed one to receive a mean value of the torque more than 10%, compared to system without change, to reduce greatly ripple spike of the electromagnetic torque. The possibility of the electric drive effective operation with FRRM in emergency operation has been shown.

Methodology Development of Computationally-Efficient Full Vehicle Simulations for the Entire Blast Event

DTIC Science & Technology

2015-08-06

Philip Kosarek1, Julien Santini1, Ravi Thyagarajan2 1 Altair Product Design, Inc., Troy, MI 2US Army TARDEC, Warren, MI This is a reprint...is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and...if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 06

Optimal Vehicle Design Using the Integrated System and Cost Modeling Tool Suite

DTIC Science & Technology

2010-08-01

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 05-08-2010 2. REPORT TYPE...the heavy-lift vehicle Ares V, the Orion capsule, and the Altair lunar lander for manned missions to the moon, was recently cancelled by the Obama

New Meta and Nanomaterials for Photorefractive Enhancement and Photorefractive Two-Beam Coupling

DTIC Science & Technology

2010-03-12

Centro de Investigacion de Quimica Aplicada Blvd. Enrique reyna, No. 140 Saltillo, Coahuila, Mexico 25253 AFOSR FA9550-09- 1 -0023 12 March 2010...information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and...if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 12

AGOR 28

DTIC Science & Technology

2014-05-09

ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for...with a collection of information if it does not display a currently valid OMB control number . 1. REPORT DATE 09 MAY 2014 2. REPORT TYPE 3. DATES...COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE AGOR 28 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

Military Child Care: DOD Is Taking Actions to Address Awareness and Availability Barriers

DTIC Science & Technology

2012-02-01

0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing...of information if it does not display a currently valid OMB control number. 1 . REPORT DATE FEB 2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012...Deployments related to the wars in Iraq and Afghanistan increased the demand for child care. The extent of military families’ out-of-pocket child

Air Force Civil Engineer, Volume 15, Number 4, 2007, 2007 Almanac

DTIC Science & Technology

2007-01-01

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE...PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Air Force Civil Engineer (AFCESA/PCT),139 Barnes Drive, Suite 1 ,Tyndall AFB,FL,32403-5319 8

Magnetocaloric Effect and Thermoelectric Cooling - A Synergistic Cooling Technology

DTIC Science & Technology

2018-01-16

REPORT DOCUMENTATION PAGE Form Approved 0 MB No. 0704-01 88 The public reporting burden for this collection of information is estimated to average...currently valid 0MB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 12. REPORT TYPE 3. DATES COVERED...code) 858-736-5069 Standard Form 298 (Rev. 8198) Prescribed by ANSI Std. Z39.18 GENERAL ENGINEERING AND RESEARCH Final Technical Report

Understanding and Recreating Visual Appearance Under Natural Illumination

DTIC Science & Technology

2011-01-01

0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing...collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE JAN 2011 2. REPORT TYPE 3. DATES COVERED 00-00...partially supported by a Microsoft Research Graduate Fel- lowship, an Okawa Foundation Grant, ONR grants N00014-08- 1 -0330 and DURIP N00014- 06- 1 -0762, as

Seabasing Innovation Cell Transfer of Goods at Sea’

DTIC Science & Technology

2004-03-01

estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining...does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 1 -Mar...2004 2. REPORT TYPE Final 3. DATES COVERED (From - To) 1 -Apr-2003 – 1 -Jul-2003 5a. CONTRACT NUMBER N0002401 WX 20594 5b. GRANT NUMBER 4. TITLE

An Analysis of the Navy’s Fiscal Year 2010 Shipbuilding Plan

DTIC Science & Technology

2010-05-01

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per...a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 01 MAY...combat ship (LCS- 1 ), photo by Mass Communication Specialist 2nd Class Daniel Barker; an Ohio class ballistic missile submarine (SSBN-735), photo by

An Analysis of the Navy’s Fiscal Year 2012 Shipbuilding Plan

DTIC Science & Technology

2011-06-01

Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response...penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE JUN 2011 2...Raymond Hall of CBO’s Budget Analysis Division produced the cost estimates under the general supervision of Sarah Jennings . Bernard Kempinski

Analysis and Design of Phase Change Thermal Control for Light Emitting Diode (LED) Spacesuit Helmet Lights

NASA Technical Reports Server (NTRS)

Bue, Grant C.; Nguyen, Hiep X.; Keller, John R.

2010-01-01

LED Helmet Extravehicular Activity Helmet Interchangeable Portable (LEHIP) lights for the Extravehicular Mobility Unit (EMU) have been built and tested and are currently being used on the International Space Station. A design is presented of the passive thermal control system consisting of a chamber filled with aluminum foam and wax. A thermal math model of LEHIP was built and correlated by test to show that the thermal design maintains electronic components within hot and cold limits for a 7 hour spacewalk in the most extreme EVA average environments, and do not pose a hazard to the crew or to components of the EMU.

Polarization mode control of long-wavelength VCSELs by intracavity patterning

DOE PAGES

Long, Christopher Michael; Mickovic, Zlatko; Dwir, Benjamin; ...

2016-04-26

Polarization mode control is enhanced in wafer-fused vertical-cavity surface-emitting lasers emitting at 1310 nm wavelength by etching two symmetrically arranged arcs above the gain structure within the laser cavity. The intracavity patterning introduces birefringence and dichroism, which discriminates between the two polarization states of the fundamental transverse modes. We find that the cavity modifications define the polarization angle at threshold with respect to the crystal axes, and increase the gain anisotropy and birefringence on average, leading to an increase in the polarization switching current. As a result, experimental measurements are explained using the spin-flip model of VCSEL polarization dynamics.

Managing Exposure to Benzene and Total Petroleum Hydrocarbons at Two Oil Refineries 1977-2014.

PubMed

Tuomi, Tapani; Veijalainen, Henna; Santonen, Tiina

2018-01-24

Air concentrations of and inhalation exposure to total petroleum hydrocarbons (TPH) and benzene was monitored separately at two oil refineries from 1977 to 2014. Prevention policies and control measures that may explain changes were surveyed. The aim was to evaluate how the application of of Occupational Health and Safety Assessment Series OHSAS 18001.04 principles as well as Environmental protection Agency EPA and European Oil Company Organisation for Environment, Health and Safety CONCAWE practices have influenced air concentrations. Benzene air concentrations declined in 11 of 17 units, six of which were associated with declining exposures. Benzene air concentrations declined across all units on average by 46%. This amounts to an average yearly decline of 1.7%. TPH air concentrations declined in 10 of 17 units, seven of which were associated with declining exposures. The average decline in TPH air concentrations was 49%, corresponding to 1.3% per year. As a result, average working day exposure in 10 of 17 units have declined significantly and today, benzene and TPH exposure in most units are well below 10% of the current Occupational Exposure Limit (OEL 8h :s). A decline in air concentrations have coincided with consistent implementation of control measures. Such measures include on-line monitoring of leaks; benzene recovery; floating container roofs; improved valves and seals; hermetic pumps; recovery of loading gases and instalment of torches in terminals; cutback in coke combustion; a new production line spanning directly from the dock to aromatics production; and recovery of loading gases in the doc. Other tools in exposure management include personal leak monitors, on-line measurements, monitoring campaigns, risk assessment, and availability and user training of protective equipment. However, improvements are still needed. Hydrocarbon or benzene air concentrations have not declined in 8 of 17 units, in some of which concentrations exceed 10% of the relevant OEL 8h value. In addition, for benzene even 10% of the current OEL, 0.1 ppm, might still possess a risk. With this in mind, methods to estimate exposure at the refineries need to be improved to enable measuring benzene concentrations <0.1 ppm. Shut downs of the refinery have been associated with peaks in exposure concentrations. Consequently, effort should be placed on safe working methods pertaining to shutdowns. Also, the connection and detachment of hoses continues to be problematic from the point of view of controlling exposure.

Impact of random and systematic recall errors and selection bias in case--control studies on mobile phone use and brain tumors in adolescents (CEFALO study).

PubMed

Aydin, Denis; Feychting, Maria; Schüz, Joachim; Andersen, Tina Veje; Poulsen, Aslak Harbo; Prochazka, Michaela; Klaeboe, Lars; Kuehni, Claudia E; Tynes, Tore; Röösli, Martin

2011-07-01

Whether the use of mobile phones is a risk factor for brain tumors in adolescents is currently being studied. Case--control studies investigating this possible relationship are prone to recall error and selection bias. We assessed the potential impact of random and systematic recall error and selection bias on odds ratios (ORs) by performing simulations based on real data from an ongoing case--control study of mobile phones and brain tumor risk in children and adolescents (CEFALO study). Simulations were conducted for two mobile phone exposure categories: regular and heavy use. Our choice of levels of recall error was guided by a validation study that compared objective network operator data with the self-reported amount of mobile phone use in CEFALO. In our validation study, cases overestimated their number of calls by 9% on average and controls by 34%. Cases also overestimated their duration of calls by 52% on average and controls by 163%. The participation rates in CEFALO were 83% for cases and 71% for controls. In a variety of scenarios, the combined impact of recall error and selection bias on the estimated ORs was complex. These simulations are useful for the interpretation of previous case-control studies on brain tumor and mobile phone use in adults as well as for the interpretation of future studies on adolescents. Copyright © 2011 Wiley-Liss, Inc.

Lower Sodium Intake and Risk of Headaches: Results From the Trial of Nonpharmacologic Interventions in the Elderly.

PubMed

Chen, Liwei; Zhang, Zhenzhen; Chen, Wen; Whelton, Paul K; Appel, Lawrence J

2016-07-01

To determine the effect of sodium (Na) reduction on occurrence of headaches. In the Trial of Nonpharmacologic Interventions in the Elderly, 975 men and woman (aged 60-80 years) with hypertension were randomized to a Na-reduction intervention or control group and were followed for up to 36 months. The study was conducted between 1992 and 1995 at 4 clinical centers (Johns Hopkins University, Wake Forest University School of Medicine, Robert Wood Johnson Medical School, and the University of Tennessee). Mean difference in Na excretion between the Na-reduction intervention and control group was significant at each follow-up visit (P < .001) with an average difference of 38.8 millimoles per 24 hours. The occurrence of headaches was significantly lower in the Na-reduction intervention group (10.5%) compared with control (14.3%) with a hazard ratio of 0.59 (95% confidence interval = 0.40, 0.88; P = .009). The risk of headaches was significantly associated with average level of Na excretion during follow-up, independent of most recent blood pressure. The relationship appeared to be nonlinear with a spline relationship and a knot at 150 millimoles per 24 hours. Reduced sodium intake, currently recommended for blood pressure control, may also reduce the occurrence of headaches in older persons with hypertension.

Auditory attention in autism spectrum disorder: An exploration of volumetric magnetic resonance imaging findings.

PubMed

Lalani, Sanam J; Duffield, Tyler C; Trontel, Haley G; Bigler, Erin D; Abildskov, Tracy J; Froehlich, Alyson; Prigge, Molly B D; Travers, Brittany G; Anderson, Jeffrey S; Zielinski, Brandon A; Alexander, Andrew; Lange, Nicholas; Lainhart, Janet E

2018-06-01

Studies have shown that individuals with autism spectrum disorder (ASD) tend to perform significantly below typically developing individuals on standardized measures of attention, even when controlling for IQ. The current study sought to examine within ASD whether anatomical correlates of attention performance differed between those with average to above-average IQ (AIQ group) and those with low-average to borderline ability (LIQ group) as well as in comparison to typically developing controls (TDC). Using automated volumetric analyses, we examined regional volume of classic attention areas including the superior frontal gyrus, anterior cingulate cortex, and precuneus in ASD AIQ (n = 38) and LIQ (n = 18) individuals along with 30 TDC. Auditory attention performance was assessed using subtests of the Test of Memory and Learning (TOMAL) compared among the groups and then correlated with regional brain volumes. Analyses revealed group differences in attention. The three groups did not differ significantly on any auditory attention-related brain volumes; however, trends toward significant size-attention function interactions were observed. Negative correlations were found between the volume of the precuneus and auditory attention performance for the AIQ ASD group, indicating larger volume related to poorer performance. Implications for general attention functioning and dysfunctional neural connectivity in ASD are discussed.

Estimation of Filling and Afterload Conditions by Pump Intrinsic Parameters in a Pulsatile Total Artificial Heart.

PubMed

Cuenca-Navalon, Elena; Laumen, Marco; Finocchiaro, Thomas; Steinseifer, Ulrich

2016-07-01

A physiological control algorithm is being developed to ensure an optimal physiological interaction between the ReinHeart total artificial heart (TAH) and the circulatory system. A key factor for that is the long-term, accurate determination of the hemodynamic state of the cardiovascular system. This study presents a method to determine estimation models for predicting hemodynamic parameters (pump chamber filling and afterload) from both left and right cardiovascular circulations. The estimation models are based on linear regression models that correlate filling and afterload values with pump intrinsic parameters derived from measured values of motor current and piston position. Predictions for filling lie in average within 5% from actual values, predictions for systemic afterload (AoPmean , AoPsys ) and mean pulmonary afterload (PAPmean ) lie in average within 9% from actual values. Predictions for systolic pulmonary afterload (PAPsys ) present an average deviation of 14%. The estimation models show satisfactory prediction and confidence intervals and are thus suitable to estimate hemodynamic parameters. This method and derived estimation models are a valuable alternative to implanted sensors and are an essential step for the development of a physiological control algorithm for a fully implantable TAH. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Prevalence survey of nosocomial infections in the Inner Mongolia Autonomous Region of China [2012-2014

PubMed Central

Liu, Wei-Ping; Hai, Yun-Ting; Zheng, Zhi-Nan; Cao, Qing-Ling

2015-01-01

Background To investigate the prevalence of nosocomial infections, the distribution of nosocomial infection sites, the use of antibiotic and the situation of detected nosocomial infection pathogens in the Inner Mongolia Autonomous Region of China from 2012 to 2014, to grasp the current conditions of regional nosocomial infections in timely, for the development of infection prevention and control measures to provide a basis for effective hospital. Methods A survey of the prevalence of nosocomial infections was conducted in target hospitals using the combination of a bedside survey and medical record review. Results In total, 101,907 inpatients were surveyed from 2012 to 2014. There were 1,997 cases of nosocomial infections, accounting for an average prevalence of 1.96%. The infection site was mainly the lower respiratory tract. Higher prevalence of nosocomial infections occurred in the comprehensive intensive care unit (ICU), Neurosurgery Department, and Hematology Department. The average rate of antibiotic use was 33.72%, and the average submission rate for bacterial cultures for patients who received therapeutic treatment with antibiotics was 28.26%. The most common pathogens associated with nosocomial infections were Gram-negative (G−) bacteria, and frequently detected bacterial pathogens included Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus. Conclusions The survey of the prevalence of nosocomial infections helped to identify problems in the control process of nosocomial infections and to develop targeted measures for the prevention and control of these infections accordingly. PMID:26543614

Climate forcing by anthropogenic aerosols

NASA Technical Reports Server (NTRS)

Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A., Jr.; Hansen, J. E.; Hofmann, D. J.

1992-01-01

Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol, in particular, has imposed a major perturbation to this forcing. Both the direct scattering of short-wavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

Climate forcing by anthropogenic aerosols.

PubMed

Charlson, R J; Schwartz, S E; Hales, J M; Cess, R D; Coakley, J A; Hansen, J E; Hofmann, D J

1992-01-24

Although long considered to be of marginal importance to global climate change, tropospheric aerosol contributes substantially to radiative forcing, and anthropogenic sulfate aerosol in particular has imposed a major perturbation to this forcing. Both the direct scattering of shortwavelength solar radiation and the modification of the shortwave reflective properties of clouds by sulfate aerosol particles increase planetary albedo, thereby exerting a cooling influence on the planet. Current climate forcing due to anthropogenic sulfate is estimated to be -1 to -2 watts per square meter, globally averaged. This perturbation is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign. Thus, the aerosol forcing has likely offset global greenhouse warming to a substantial degree. However, differences in geographical and seasonal distributions of these forcings preclude any simple compensation. Aerosol effects must be taken into account in evaluating anthropogenic influences on past, current, and projected future climate and in formulating policy regarding controls on emission of greenhouse gases and sulfur dioxide. Resolution of such policy issues requires integrated research on the magnitude and geographical distribution of aerosol climate forcing and on the controlling chemical and physical processes.

The use of bioimpedance analysis to evaluate lymphedema.

PubMed

Warren, Anne G; Janz, Brian A; Slavin, Sumner A; Borud, Loren J

2007-05-01

Lymphedema, a chronic disfiguring condition resulting from lymphatic dysfunction or disruption, can be difficult to accurately diagnose and manage. Of particular challenge is identifying the presence of clinically significant limb swelling through simple and noninvasive methods. Many historical and currently used techniques for documenting differences in limb volume, including volume displacement and circumferential measurements, have proven difficult and unreliable. Bioimpedance spectroscopy analysis, a technology that uses resistance to electrical current in comparing the composition of fluid compartments within the body, has been considered as a cost-effective and reproducible alternative for evaluating patients with suspected lymphedema. All patients were recruited through the Beth Israel Deaconess Medical Center Lymphedema Clinic. A total of 15 patients (mean age: 55.2 years) with upper-extremity or lower-extremity lymphedema as documented by lymphoscintigraphy underwent bioimpedance spectroscopy analysis using an Impedimed SFB7 device. Seven healthy medical students and surgical residents (mean age: 26.9 years) were selected to serve as normal controls. All study participants underwent analysis of both limbs, which allowed participants to act as their own controls. The multifrequency bioimpedance device documented impedance values for each limb, with lower values correlating with higher levels of accumulated protein-rich edematous fluid. The average ratio of impedance to current flow of the affected limb to the unaffected limb in lymphedema patients was 0.9 (range: 0.67 to 1.01). In the control group, the average impedance ratio of the participant's dominant limb to their nondominant limb was 0.99 (range: 0.95 to 1.02) (P = 0.01). Bioimpedance spectroscopy can be used as a reliable and accurate tool for documenting the presence of lymphedema in patients with either upper- or lower-extremity swelling. Measurement with the device is quick and simple and results are reproducible among patients. Given significant limitations with other methods of evaluating lymphedema, the use of bioimpedance analysis may aid in the diagnosis of lymphedema and allow for tracking patients over time as they proceed with treatment of their disease.

The behavior of dissolved inorganic selenium in the Changjiang Estuary

NASA Astrophysics Data System (ADS)

Chang, Yan; Zhang, Jing; Qu, Jianguo; Zhang, Guosen; Zhang, Anyu; Zhang, Ruifeng

2016-02-01

To investigate the behavior of inorganic selenium species in the Changjiang Estuary, samples were taken during summer (July 2011) and winter (March 2012). Dissolved inorganic selenium (DISe) concentrations averaged 1.79 nmol/L in summer and 1.24 nmol/L in winter; the average selenite [Se(IV)] to selenate [Se(VI)] ratio [Se(IV)/Se(VI)] was 0.42 in summer and 0.61 in winter. The data show that Se(IV) and Se(VI) concentrations in the estuary behaved strictly conservatively during winter but non-conservatively during summer due to adsorption by suspended particulate matter (SPM) and assimilation by phytoplankton. In addition, the Se concentration distributions in the Changjiang Estuary were controlled by three water masses, each with a specific Se(IV)/Se(VI) ratio "signature": the Changjiang Water input, the Taiwan Warm Current, and the Yellow Sea Coastal Current. The Se(IV) concentrations were related to the nitrate, silicate, and phosphate concentrations in the estuary. The DISe and Se(IV) concentrations were comparable to those found in other coastal regions and estuaries, which were considered to be natural levels.

Rift Valley Fever Prediction and Risk Mapping: 2014-2015 Season

NASA Technical Reports Server (NTRS)

Anyamba, Assaf

2015-01-01

Extremes in either direction (+-) of precipitation temperature have significant implications for disease vectors and pathogen emergence and spread Magnitude of ENSO influence on precipitation temperature cannot be currently predicted rely on average history and patterns. Timing of event and emergence disease can be exploited (GAP) in to undertake vector control and preparedness measures. Currently - no risk for ecologically-coupled RVFV activity however we need to be vigilant during the coming fall season due the ongoing buildup of energy in the central Pacific Ocean. Potential for the dual-use of the RVF Monitor system for other VBDs Need to invest in early ground surveillance and the use of rapid field diagnostic capabilities for vector identification and virus isolation.

Health effects of indoor odorants.

PubMed Central

Cone, J E; Shusterman, D

1991-01-01

People assess the quality of the air indoors primarily on the basis of its odors and on their perception of associated health risk. The major current contributors to indoor odorants are human occupant odors (body odor), environmental tobacco smoke, volatile building materials, bio-odorants (particularly mold and animal-derived materials), air fresheners, deodorants, and perfumes. These are most often present as complex mixtures, making measurement of the total odorant problem difficult. There is no current method of measuring human body odor, other than by human panel studies of expert judges of air quality. Human body odors have been quantitated in terms of the "olf" which is the amount of air pollution produced by the average person. Another quantitative unit of odorants is the "decipol," which is the perceived level of pollution produced by the average human ventilated by 10 L/sec of unpolluted air or its equivalent level of dissatisfaction from nonhuman air pollutants. The standard regulatory approach, focusing on individual constituents or chemicals, is not likely to be successful in adequately controlling odorants in indoor air. Besides the current approach of setting minimum ventilation standards to prevent health effects due to indoor air pollution, a standard based on the olf or decipol unit might be more efficacious as well as simpler to measure. PMID:1821378

The descriptive epidemiology of DSM-IV Adult ADHD in the World Health Organization World Mental Health Surveys.

PubMed

Fayyad, John; Sampson, Nancy A; Hwang, Irving; Adamowski, Tomasz; Aguilar-Gaxiola, Sergio; Al-Hamzawi, Ali; Andrade, Laura H S G; Borges, Guilherme; de Girolamo, Giovanni; Florescu, Silvia; Gureje, Oye; Haro, Josep Maria; Hu, Chiyi; Karam, Elie G; Lee, Sing; Navarro-Mateu, Fernando; O'Neill, Siobhan; Pennell, Beth-Ellen; Piazza, Marina; Posada-Villa, José; Ten Have, Margreet; Torres, Yolanda; Xavier, Miguel; Zaslavsky, Alan M; Kessler, Ronald C

2017-03-01

We previously reported on the cross-national epidemiology of ADHD from the first 10 countries in the WHO World Mental Health (WMH) Surveys. The current report expands those previous findings to the 20 nationally or regionally representative WMH surveys that have now collected data on adult ADHD. The Composite International Diagnostic Interview (CIDI) was administered to 26,744 respondents in these surveys in high-, upper-middle-, and low-/lower-middle-income countries (68.5% mean response rate). Current DSM-IV/CIDI adult ADHD prevalence averaged 2.8% across surveys and was higher in high (3.6%)- and upper-middle (3.0%)- than low-/lower-middle (1.4%)-income countries. Conditional prevalence of current ADHD averaged 57.0% among childhood cases and 41.1% among childhood subthreshold cases. Adult ADHD was significantly related to being male, previously married, and low education. Adult ADHD was highly comorbid with DSM-IV/CIDI anxiety, mood, behavior, and substance disorders and significantly associated with role impairments (days out of role, impaired cognition, and social interactions) when controlling for comorbidities. Treatment seeking was low in all countries and targeted largely to comorbid conditions rather than to ADHD. These results show that adult ADHD is prevalent, seriously impairing, and highly comorbid but vastly under-recognized and undertreated across countries and cultures.

Single-ping ADCP measurements in the Strait of Gibraltar

NASA Astrophysics Data System (ADS)

Sammartino, Simone; García Lafuente, Jesús; Naranjo, Cristina; Sánchez Garrido, José Carlos; Sánchez Leal, Ricardo

2016-04-01

In most Acoustic Doppler Current Profiler (ADCP) user manuals, it is widely recommended to apply ensemble averaging of the single-pings measurements, in order to obtain reliable observations of the current speed. The random error related to the single-ping measurement is typically too high to be used directly, while the averaging operation reduces the ensemble error of a factor of approximately √N, with N the number of averaged pings. A 75 kHz ADCP moored in the western exit of the Strait of Gibraltar, included in the long-term monitoring of the Mediterranean outflow, has recently served as test setup for a different approach to current measurements. The ensemble averaging has been disabled, while maintaining the internal coordinate conversion made by the instrument, and a series of single-ping measurements has been collected every 36 seconds during a period of approximately 5 months. The huge amount of data has been fluently handled by the instrument, and no abnormal battery consumption has been recorded. On the other hand a long and unique series of very high frequency current measurements has been collected. Results of this novel approach have been exploited in a dual way: from a statistical point of view, the availability of single-ping measurements allows a real estimate of the (a posteriori) ensemble average error of both current and ancillary variables. While the theoretical random error for horizontal velocity is estimated a priori as ˜2 cm s-1 for a 50 pings ensemble, the value obtained by the a posteriori averaging is ˜15 cm s-1, with an asymptotical behavior starting from an averaging size of 10 pings per ensemble. This result suggests the presence of external sources of random error (e.g.: turbulence), of higher magnitude than the internal sources (ADCP intrinsic precision), which cannot be reduced by the ensemble averaging. On the other hand, although the instrumental configuration is clearly not suitable for a precise estimation of turbulent parameters, some hints of the turbulent structure of the flow can be obtained by the empirical computation of zonal Reynolds stress (along the predominant direction of the current) and rate of production and dissipation of turbulent kinetic energy. All the parameters show a clear correlation with tidal fluctuations of the current, with maximum values coinciding with flood tides, during the maxima of the outflow Mediterranean current.

The difference between energy consumption and energy cost: Modelling energy tariff structures for water resource recovery facilities.

PubMed

Aymerich, I; Rieger, L; Sobhani, R; Rosso, D; Corominas, Ll

2015-09-15

The objective of this paper is to demonstrate the importance of incorporating more realistic energy cost models (based on current energy tariff structures) into existing water resource recovery facilities (WRRFs) process models when evaluating technologies and cost-saving control strategies. In this paper, we first introduce a systematic framework to model energy usage at WRRFs and a generalized structure to describe energy tariffs including the most common billing terms. Secondly, this paper introduces a detailed energy cost model based on a Spanish energy tariff structure coupled with a WRRF process model to evaluate several control strategies and provide insights into the selection of the contracted power structure. The results for a 1-year evaluation on a 115,000 population-equivalent WRRF showed monthly cost differences ranging from 7 to 30% when comparing the detailed energy cost model to an average energy price. The evaluation of different aeration control strategies also showed that using average energy prices and neglecting energy tariff structures may lead to biased conclusions when selecting operating strategies or comparing technologies or equipment. The proposed framework demonstrated that for cost minimization, control strategies should be paired with a specific optimal contracted power. Hence, the design of operational and control strategies must take into account the local energy tariff. Copyright © 2015 Elsevier Ltd. All rights reserved.

Current status of radiological protection at nuclear power stations in Japan.

PubMed

Suzuki, Akira; Hori, Shunsuke

2011-07-01

The radiation dose to workers at nuclear power stations (NPSs) in Japan was drastically reduced between the late-1970s and the early-1990s by continuous dose-reduction programmes. The total collective dose of radiation workers in FY 2008 was 84.04 person Sv, while the average collective dose was 1.5 person Sv per reactor. The average annual individual dose was 1.1 mSv and the maximum annual individual dose was 19.5 mSv. These values are sufficiently lower than the regulatory dose limits. Radioactive effluent released from NPSs is already so trivial that additional protective measures will not be necessary. Experience in radiation protection at NPSs has been accumulated over 40 y and will be very useful in establishing a rational radiation control system in the future.

Design and performance evaluation of a master controller for endovascular catheterization.

PubMed

Guo, Jin; Guo, Shuxiang; Tamiya, Takashi; Hirata, Hideyuki; Ishihara, Hidenori

2016-01-01

It is difficult to manipulate a flexible catheter to target a position within a patient's complicated and delicate vessels. However, few researchers focused on the controller designs with much consideration of the natural catheter manipulation skills obtained from manual catheterization. Also, the existing catheter motion measurement methods probably lead to the difficulties in designing the force feedback device. Additionally, the commercially available systems are too expensive which makes them cost prohibitive to most hospitals. This paper presents a simple and cost-effective master controller for endovascular catheterization that can allow the interventionalists to apply the conventional pull, push and twist of the catheter used in current practice. A catheter-sensing unit (used to measure the motion of the catheter) and a force feedback unit (used to provide a sense of resistance force) are both presented. A camera was used to allow a contactless measurement avoiding additional friction, and the force feedback in the axial direction was provided by the magnetic force generated between the permanent magnets and the powered coil. Performance evaluation of the controller was evaluated by first conducting comparison experiments to quantify the accuracy of the catheter-sensing unit, and then conducting several experiments to evaluate the force feedback unit. From the experimental results, the minimum and the maximum errors of translational displacement were 0.003 mm (0.01 %) and 0.425 mm (1.06 %), respectively. The average error was 0.113 mm (0.28 %). In terms of rotational angles, the minimum and the maximum errors were 0.39°(0.33 %) and 7.2°(6 %), respectively. The average error was 3.61°(3.01 %). The force resolution was approximately 25 mN and a maximum current of 3A generated an approximately 1.5 N force. Based on analysis of requirements and state-of-the-art computer-assisted and robot-assisted training systems for endovascular catheterization, a new master controller with force feedback interface was proposed to maintain the natural endovascular catheterization skills of the interventionalists.

RMP ELM Suppression in DIII-D Plasmas with ITER Similar Shapes and Collisionalities

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

Evans, T.E.; Fenstermacher, M. E.; Moyer, R.A.

2008-01-01

Large Type-I edge localized modes (ELMs) are completely eliminated with small n = 3 resonant magnetic perturbations (RMP) in low average triangularity, = 0.26, plasmas and in ITER similar shaped (ISS) plasmas, = 0.53, with ITER relevant collisionalities ve 0.2. Significant differences in the RMP requirements and in the properties of the ELM suppressed plasmas are found when comparing the two triangularities. In ISS plasmas, the current required to suppress ELMs is approximately 25% higher than in low average triangularity plasmas. It is also found that the width of the resonant q95 window required for ELM suppression is smaller inmore » ISS plasmas than in low average triangularity plasmas. An analysis of the positions and widths of resonant magnetic islands across the pedestal region, in the absence of resonant field screening or a self-consistent plasma response, indicates that differences in the shape of the q profile may explain the need for higher RMP coil currents during ELM suppression in ISS plasmas. Changes in the pedestal profiles are compared for each plasma shape as well as with changes in the injected neutral beam power and the RMP amplitude. Implications of these results are discussed in terms of requirements for optimal ELM control coil designs and for establishing the physics basis needed in order to scale this approach to future burning plasma devices such as ITER.« less

Advanced control of neutral beam injected power in DIII-D

DOE PAGES

Pawley, Carl J.; Crowley, Brendan J.; Pace, David C.; ...

2017-03-23

In the DIII-D tokamak, one of the most powerful techniques to control the density, temperature and plasma rotation is by eight independently modulated neutral beam sources with a total power of 20 MW. The rapid modulation requires a high degree of reproducibility and precise control of the ion source plasma and beam acceleration voltage. Recent changes have been made to the controls to provide a new capability to smoothly vary the beam current and beam voltage during a discharge, while maintaining the modulation capability. The ion source plasma inside the arc chamber is controlled through feedback from the Langmuir probesmore » measuring plasma density near the extraction end. To provide the new capability, the plasma control system (PCS) has been enabled to change the Langmuir probe set point and the beam voltage set point in real time. When the PCS varies the Langmuir set point, the plasma density is directly controlled in the arc chamber, thus changing the beam current (perveance) and power going into the tokamak. Alternately, the PCS can sweep the beam voltage set point by 20 kV or more and adjust the Langmuir probe setting to match, keeping the perveance constant and beam divergence at a minimum. This changes the beam power and average neutral particle energy, which changes deposition in the tokamak plasma. The ion separating magnetic field must accurately match the beam voltage to protect the beam line. To do this, the magnet current control accurately tracks the beam voltage set point. In conclusion, these new capabilities allow continuous in-shot variation of neutral beam ion energy to complement« less

Field-aligned current and auroral Hall current characteristics derived from the Swarm constellation

NASA Astrophysics Data System (ADS)

Huang, Tao; Wang, Hui; Hermann, Luehr

2017-04-01

On the basis of field-aligned currents (FACs) and Hall currents derived from high-resolution magnetic field data of the Swarm constellation the average characteristics of these two current systems in the auroral regions are comprehensively investigated by statistical methods. This is the first study considering both current types simultaneously and for both hemispheres. The FAC distribution, derived from the Swarm dual-spacecraft approach, reveals the well-known features of Region 1 (R1) and Region 2 (R2) FACs. At high latitudes, Region 0 (R0) FACs appear on the dayside. Their direction depends on the orientation of the interplanetary magnetic field (IMF) By component. Of particular interest is the distribution of auroral Hall currents. The most prominent auroral electrojets are found to be closely controlled by the solar wind input. But there is no dependence on the IMF By orientation. The eastward electrojet is about twice as strong in summer as in winter. Conversely, the westward electrojet shows less dependence on season. Part of the electrojet current is closed over the polar cap. Here the seasonal variation of conductivity mainly controls the current density. There is a clear channeling of return currents over the polar cap. Depending on IMF By orientation most of the current is flowing either on the dawn or dusk side. The direction of Hall currents in the noon sector depends directly on the orientation of the IMF By. This is true for both signs of the IMF Bz component. But largest differences between summer and winter seasons are found for northward IMF Bz. Around the midnight sector the westward substorm electrojet is dominating. As expected, it is highly dependent on magnetic activity, but shows only little response to the IMF By polarity.

Wavefront sensorless adaptive optics ophthalmoscopy in the human eye

PubMed Central

Hofer, Heidi; Sredar, Nripun; Queener, Hope; Li, Chaohong; Porter, Jason

2011-01-01

Wavefront sensor noise and fidelity place a fundamental limit on achievable image quality in current adaptive optics ophthalmoscopes. Additionally, the wavefront sensor ‘beacon’ can interfere with visual experiments. We demonstrate real-time (25 Hz), wavefront sensorless adaptive optics imaging in the living human eye with image quality rivaling that of wavefront sensor based control in the same system. A stochastic parallel gradient descent algorithm directly optimized the mean intensity in retinal image frames acquired with a confocal adaptive optics scanning laser ophthalmoscope (AOSLO). When imaging through natural, undilated pupils, both control methods resulted in comparable mean image intensities. However, when imaging through dilated pupils, image intensity was generally higher following wavefront sensor-based control. Despite the typically reduced intensity, image contrast was higher, on average, with sensorless control. Wavefront sensorless control is a viable option for imaging the living human eye and future refinements of this technique may result in even greater optical gains. PMID:21934779

Disparities in emergency department visits in American children with asthma: 2006-2010.

PubMed

Zhang, Qi; Lamichhane, Rajan; Diggs, Leigh Ann

2017-09-01

This article was to examine the trends in emergency department (ED) visits for asthma among American children in 2006-2010 across sociodemographic factors, parental smoking status, and children's body weight status. We analyzed 5,535 children aged 2-17 years with current asthma in the Asthma Call-Back Survey in 2006-2010. Multivariate log binomial regression was used to examine the disparities of ED visits by demographics, socioeconomic status, parental smoking status, children's body weight status, and the level of asthma control. We controlled for average state-level air pollutants. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were reported. Minority children with current asthma had higher risks of ED visits compared with white children in 2009 and 2010, e.g., the PR (95% CI) for black children in 2009 was 3.64 (1.79, 7.41). Children who had current asthma and more highly educated parents experienced a higher risk of ED visits in 2007 (PRs [95% CI] = 2.15 [1.02, 4.53] and 2.97 [1.29, 6.83] for children with some college or college-graduated parents), but not significant in other years. Children with uncontrolled asthma were significantly more likely to visit the ED in 2008 (PRs [95% CI] = 2.79 [1.44, 5.41] and 6.96 [3.55, 13.64] for not-well-controlled and very poorly controlled children with asthma). Minority children with current asthma or children with uncontrolled asthma were more likely to visit EDs for asthma treatment. However, the disparities in ED visits across sociodemographics, health status, or asthma control vary in scale and significance across time. More research is needed to explain these differences.

How do Air Traffic Controllers Use Automation and Tools Differently During High Demand Situations?

NASA Technical Reports Server (NTRS)

Kraut, Joshua M.; Mercer, Joey; Morey, Susan; Homola, Jeffrey; Gomez, Ashley; Prevot, Thomas

2013-01-01

In a human-in-the-loop simulation, two air traffic controllers managed identical airspace while burdened with higher than average workload, and while using advanced tools and automation designed to assist with scheduling aircraft on multiple arrival flows to a single meter fix. This paper compares the strategies employed by each controller, and investigates how the controllers' strategies change while managing their airspace under more normal workload conditions and a higher workload condition. Each controller engaged in different methods of maneuvering aircraft to arrive on schedule, and adapted their strategies to cope with the increased workload in different ways. Based on the conclusions three suggestions are made: that quickly providing air traffic controllers with recommendations and information to assist with maneuvering and scheduling aircraft when burdened with increased workload will improve the air traffic controller's effectiveness, that the tools should adapt to the strategy currently employed by a controller, and that training should emphasize which traffic management strategies are most effective given specific airspace demands.

Force and Moment Plots from Pacejka 2002 Magic Formula Tire Model Coefficients

DTIC Science & Technology

2010-09-01

Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including...failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 10 SEP 2010 2. REPORT...forces and moments applied to the tires. Many vehicle simulation programs such as MSC.Software ADAMS, Altair HyperWorks MotionSolve, etc. use the Magic

Study of Large-Scale Wave Structure and Development of Equatorial Plasma Bubbles Using the C/NOFS Satellite

DTIC Science & Technology

2012-10-31

19241-FR-12-438 October 2012 3 Figure 1 . Two maps showing isodensity contours of the F layer, which were obtained with ALTAIR during the PSSR...REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 31-10-2012 2. REPORT TYPE

Alternative Fuels for use in DoD/Army Tactical Ground Systems

DTIC Science & Technology

2011-02-03

Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response...for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 03 FEB 2011 2...and approval of new fuels • What has been done so far – some examples – TRL 1 -4: Fuel properties – TRL 5-6: Component / engine evaluations – TRL 7-8

Pretreatment of Human Epidermal Keratinocytes In Vitro With Ethacrynic Acid Reduces Sulfur Mustard Cytotoxicity

DTIC Science & Technology

2004-01-01

estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the...display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES...Ethacrynic Acid Reduces 5b. GRANT NUMBER Sulfur Mustard Toxicity 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Gross, CL, Nipwoda, MT, Nealley

Rand Corporation National Security Research Division. Annual Report 2010-2011

DTIC Science & Technology

2011-01-01

Approval of Sole-Source DoD Contracts to Native American Organizations A n nuA l R e p o R t 2 0 1 0 – 2 0 11 29 Alternative Fuels for the...average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed...shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1

Accelerated Testing and Preventive Maintenance in Acquisition, Maintenance and Operation of Vehicle Systems using Time-Dependent Reliability/Durability Principles

DTIC Science & Technology

2011-05-24

1 ARC 5/24/2011 UNCLASSIFIED: Distribution Statement A. Approved for public release Amandeep Singh1, Igor Baseski1,2 1U.S. Army, RDECOM TARDEC...of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering...currently valid OMB control number. 1 . REPORT DATE 24 MAY 2011 2. REPORT TYPE Briefing Charts 3. DATES COVERED 24-05-2011 to 24-05-2011 4. TITLE

Vehicle-Snow Interaction: Modeling, Testing and Validation

DTIC Science & Technology

2009-10-12

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 12 OCT 2009 2. REPORT TYPE N/A 3. DATES COVERED - 4...surface – Snow temperature ~-6 C – Stored in a freezer ~-25 C • Microtribometer – – Temperature ~-10C – Pin sizes ( 1 /8”, 1 /4”, 3/8”, 1 /2”) – Force or

Special Inspector General for Afghanistan Reconstruction Quarterly Report to the United States Congress

DTIC Science & Technology

2014-10-30

reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions ... information if it does not display a currently valid OMB control number. 1. REPORT DATE 30 OCT 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00...salaries until the end of the year. In response to a request from SIGAR for information , State Department officials said they had not yet received a formal

BioReD: Biomarkers and Tools for Reductive Dechlorination Site Assessment, Monitoring and Management

DTIC Science & Technology

2013-11-01

1,2,3-Trichloropropane 1 -CP 1 - Chloropropane 2-CP 2- Chloropropane 2,2-DCP 2,2-Dichloropropane 2-Br- 1 -CP 1 -Bromo- 1 - chloropropane 6-FAM 6...information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and...if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 07

Effects of 4-ter-Octylphenol on Xenopus tropicalis in a Long Term Exposure

DTIC Science & Technology

2011-03-17

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 17...STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT We exposed Xenopus tropicalis to 1 , 3.3, 11 and 36 ug/L

Drag Reduction Control for Flow over a Hump with Surface-Mounted Thermoacoustic Actuator

DTIC Science & Technology

2015-01-06

integrating qwall over the actuator stripe and taking the average over one oscillation period. This gives Q̇ = 2σq̂/π. Now we can define the drag...itself to produce acoustic waves, the input AC current sinusoidally heats this membrane due to Joule heating and creates surface pressure...such that its heat ca- pacity per unit area (HCPUA) is at least two orders of magnitude smaller than that of the metal . Since the output acoustic power

Rapid Aluminum Nanoparticle Production by Milling in NH3 and CH3NH2 Atmospheres: An Experimental and Theoretical Study

DTIC Science & Technology

2015-07-01

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 1 July 2015 2. REPORT TYPE...ABSTRACT Unclassified c. THIS PAGE Unclassified SAR 105 19b. TELEPHONE NO (include area code) N/A Standard Form 298 (Rev. 8-98

Evaluation of MOF-74, MOF-177, and ZIF-8 for the Removal of Toxic Industrial Chemicals

DTIC Science & Technology

2008-11-01

34 (Chae et al, 2004) MOF-199 (Cu-BTC, HKUST - 1 ). "Benzene-1,3,5-tricarboxylic acid (5.0 g, 24 mmol, Aldrich) and copper (II) nitrate hemipentahydrate...estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining...does not display a currently valid OMB control number PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) XX-11-2008

International Symposium on 21st Century Challenges in Computational Engineering and Science

DTIC Science & Technology

2010-02-26

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 ...it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. 1 . REPORT DATE (DD-MM-YYYY) 26...CHALLENGES IN COMPUTATIONAL ENGINEERING AND SCIENCE 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-09- 1 -0648 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

Improving the Capacity of Language Recognition Systems to Handle Rare Languages Using Radio Broadcast Data

DTIC Science & Technology

2011-01-01

Training databases for LRE2007 and LRE2009 systems CF CallFriend CH CallHome F Fisher English Part 1 .and 2. F Fisher Levantine Arabic F HKUST Mandarin...information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering...information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM

An Analysis of the Navy’s Fiscal Year 2014 Shipbuilding Plan

DTIC Science & Technology

2013-10-23

fuel and a few other supplies to ships at sea) at a rate of 1 per year through the 2020s; that program would conclude in 2033. The plan also...reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 23 OCT 2013 2. REPORT TYPE 3. DATES COVERED 00-00-2013 to 00-00

An Analysis of the Navy’s Fiscal Year 2013 Shipbuilding Plan

DTIC Science & Technology

2012-07-01

Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response...penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE JUL 2012 2...4456 ContentsSummary iii Changes in Inventory Goals Under the 2013 Plan 1 Box 1 . The Roles of Major Types of Ships in the Navy’s Battle Force Fleet 2

Situation awareness system for Canada

NASA Astrophysics Data System (ADS)

Hill, Andrew

1999-07-01

Situation awareness encompasses a knowledge of orders, plans and current knowledge of friendly force actions. Knowing where you are and being able to transmit that information in near real-time to other friendly forces provides the ability to exercise precise command and control over those forces. With respect to current command and control using voice methods, between 40 percent and 60 percent of Combat Net Radio traffic relates to location reporting of some sort. Commanders at Battle Group and below spend, on average, 40 percent of their total time performing position and navigation related functions. The need to rapidly transfer own force location information throughout a force and to process the received information quickly, accurately and reliably provides the rationale for the requirement for an automated situation awareness system. This paper describes the Situation Awareness System (SAS) being developed by Computing Devices Canada for the Canadian Department of National Defence as a component of the Position Determination and Navigation for Land Forces program. The SAS is being integrated with the Iris Tactical Command, Control, Communications System, which is also being developed by Computing Devices. The SAS software provides a core operating environment onto which command and control functionality can be easily added to produce general and specialist battlefield management systems.

Decentral Smart Grid Control

NASA Astrophysics Data System (ADS)

Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

2015-01-01

Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals.

ECCD-induced tearing mode stabilization via active control in coupled NIMROD/GENRAY HPC simulations

NASA Astrophysics Data System (ADS)

Jenkins, Thomas; Kruger, S. E.; Held, E. D.; Harvey, R. W.

2012-10-01

Actively controlled electron cyclotron current drive (ECCD) applied within magnetic islands formed by neoclassical tearing modes (NTMs) has been shown to control or suppress these modes. In conjunction with ongoing experimental efforts, the development and verification of integrated numerical models of this mode stabilization process is of paramount importance in determining optimal NTM stabilization strategies for ITER. In the advanced model developed by the SWIM Project, the equations/closures of extended (not reduced) MHD contain new terms arising from 3D (not toroidal or bounce-averaged) RF-induced quasilinear diffusion. The quasilinear operator formulation models the equilibration of driven current within the island using the same extended MHD dynamics which govern the physics of island formation, yielding a more accurate and self-consistent picture of 3D island response to RF drive. Results of computations which model ECRF deposition using ray tracing, assemble the 3D quasilinear operator from ray/profile data, and calculate the resultant forces within the extended MHD code will be presented. We also discuss the efficacy of various numerical active feedback control systems, which gather data from synthetic diagnostics to dynamically trigger and spatially align RF fields.

How the novel integration of electrolysis in tidal flow constructed wetlands intensifies nutrient removal and odor control.

PubMed

Ju, Xinxin; Wu, Shubiao; Huang, Xu; Zhang, Yansheng; Dong, Renjie

2014-10-01

Intensified nutrient removal and odor control in a novel electrolysis-integrated tidal flow constructed wetland were evaluated. The average removal efficiencies of COD and NH4(+)-N were above 85% and 80% in the two experimental wetlands at influent COD concentration of 300 mg/L and ammonium nitrogen concentration of 60 mg/L regardless of electrolysis integration. Effluent nitrate concentration decreased from 2.5mg/L to 0.5mg/L with the reduction in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2). This result reveals the important role of current intensity in nitrogen transformation. Owing to the ferrous and ferric iron coagulant formed through the electro-dissolution of the iron anode, electrolysis integration not only exerted a positive effect on phosphorus removal but also effectively inhibited sulfide accumulation for odor control. Although electrolysis operation enhanced nutrient removal and promoted the emission of CH4, no significant difference was observed in the microbial communities and abundance of the two experimental wetlands. Copyright © 2014 Elsevier Ltd. All rights reserved.

A modeling study of the time-averaged electric currents in the vicinity of isolated thunderstorms

NASA Technical Reports Server (NTRS)

Driscoll, Kevin T.; Blakeslee, Richard J.; Baginski, Michael E.

1992-01-01

A thorough examination of the results of a time-dependent computer model of a dipole thunderstorm revealed that there are numerous similarities between the time-averaged electrical properties and the steady-state properties of an active thunderstorm. Thus, the electrical behavior of the atmosphere in the vicinity of a thunderstorm can be determined with a formulation similar to what was first described by Holzer and Saxon (1952). From the Maxwell continuity equation of electric current, a simple analytical equation was derived that expresses a thunderstorm's average current contribution to the global electric circuit in terms of the generator current within the thundercloud, the intracloud lightning current, the cloud-to-ground lightning current, the altitudes of the charge centers, and the conductivity profile of the atmosphere. This equation was found to be nearly as accurate as the more computationally expensive numerical model, even when it is applied to a thunderstorm with a reduced conductivity thundercloud, a time-varying generator current, a varying flash rate, and a changing lightning mix.

Origins of the Kuroshio and Mindanao Currents

DTIC Science & Technology

2016-03-30

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1...Objectively napped time- averaged sea surface hieght (right) and surface geostrophic current (left). The mapped fields are estimated by objectively mapping

Characteristics of single Ca(2+) channel kinetics in feline hypertrophied ventricular myocytes.

PubMed

Yang, Xiangjun; Hui, Jie; Jiang, Tingbo; Song, Jianping; Liu, Zhihua; Jiang, Wenping

2002-04-01

To explore the mechanism underlying the prolongation of action potential and delayed inactivation of the L-type Ca(2+) (I(Ca, L)) current in a feline model of left ventricular system hypertension and concomitant hypertrophy. Single Ca(2+) channel properties in myocytes isolated from normal and pressure overloaded cat left ventricles were studied, using patch-clamp techniques. Left ventricular pressure overload was induced by partial ligation of the ascending aorta for 4 - 6 weeks. The amplitude of single Ca(2+) channel current evoked by depolarizing pulses from -40 mV to 0 mV was 1.02 +/- 0.03 pA in normal cells and 1.05 +/- 0.03 pA in hypertrophied cells, and there was no difference in single channel current-voltage relationships between the groups since slope conductance was 26.2 +/- 1.0 pS in normal and hypertrophied cells, respectively. Peak amplitudes of the ensemble-averaged single Ca(2+) channel currents were not different between the two groups of cells. However, the amplitude of this averaged current at the end of the clamp pulse was significantly larger in hypertrophied cells than in normal cells. Open-time histograms revealed that open-time distribution was fitted by a single exponential function in channels of normal cells and by a two exponential function in channels of hypertrophied cells. The number of long-lasting openings was increased in channels of hypertrophied cells, and therefore the calculated mean open time of the channel was significantly longer compared to normal controls. Kinetic changes in the Ca(2+) channel may underlie both hypertrophy-associated delayed inactivation of the Ca(2+) current and, in part, the pressure overload-induced action potential lengthening in this cat model of ventricular left systolic hypertension and hypertrophy.

Impact of Narrative Expressive Writing on Heart Rate, Heart Rate Variability, and Blood Pressure After Marital Separation.

PubMed

Bourassa, Kyle J; Allen, John J B; Mehl, Matthias R; Sbarra, David A

Divorce is a common stressor that is associated with increased risk for poor long-term physical and mental health. Using an experimental design, the current study examined the impact of expressive writing (EW) on average heart rate (HR), HR variability (HRV), and blood pressure (BP) 7.5 months later. Participants from a community sample of recently separated adults (N = 109) were assigned to one of three conditions: traditional EW, narrative EW, or a control writing condition, and were assessed three times for an average of 7.5 months. Each study visit included 27 minutes of physiological assessment; the primary outcomes at each assessment were mean-level HR, HRV, BP scores averaged across six different tasks. Participants in the traditional EW condition did not significantly differ from control participants in their later HR, HRV, or BP. However, relative to control participants, those in the narrative EW condition had significantly lower HR (B = -3.41, 95% confidence interval = -5.76 to -1.06, p = .004) and higher HRV 7.5 months later (B = 0.41, 95% confidence interval = 0.16 to 0.74, p = .001). When comparing narrative EW participants to those in the traditional EW and control writing as a single group, these effects remained and were moderately sized, Cohen d values of -0.61 and 0.60, respectively, and durable across all task conditions when analyzed in independent models. The writing condition groups did not differ in their later BP. Narrative EW decreased HR and increased HRV after marital separation but did not affect BP. We discuss the possible disconnect between psychology and physiology in response to EW, as well as possible future clinical applications after marital separation.

Effect of surface nano/micro-structuring on the early formation of microbial anodes with Geobacter sulfurreducens: Experimental and theoretical approaches.

PubMed

Champigneux, Pierre; Renault-Sentenac, Cyril; Bourrier, David; Rossi, Carole; Delia, Marie-Line; Bergel, Alain

2018-06-01

Smooth and nano-rough flat gold electrodes were manufactured with controlled Ra of 0.8 and 4.5nm, respectively. Further nano-rough surfaces (Ra 4.5nm) were patterned with arrays of micro-pillars 500μm high. All these electrodes were implemented in pure cultures of Geobacter sulfurreducens, under a constant potential of 0.1V/SCE and with a single addition of acetate 10mM to check the early formation of microbial anodes. The flat smooth electrodes produced an average current density of 0.9A·m -2 . The flat nano-rough electrodes reached 2.5A·m -2 on average, but with a large experimental deviation of ±2.0A·m -2 . This large deviation was due to the erratic colonization of the surface but, when settled on the surface, the cells displayed current density that was directly correlated to the biofilm coverage ratio. The micro-pillars considerably improved the experimental reproducibility by offering the cells a quieter environment, facilitating biofilm development. Current densities of up to 8.5A·m -2 (per projected surface area) were thus reached, in spite of rate limitation due to the mass transport of the buffering species, as demonstrated by numerical modelling. Nano-roughness combined with micro-structuring increased current density by a factor close to 10 with respect to the smooth flat surface. Copyright © 2018 Elsevier B.V. All rights reserved.

Scaling of average weighted shortest path and average receiving time on weighted expanded Koch networks

NASA Astrophysics Data System (ADS)

Wu, Zikai; Hou, Baoyu; Zhang, Hongjuan; Jin, Feng

2014-04-01

Deterministic network models have been attractive media for discussing dynamical processes' dependence on network structural features. On the other hand, the heterogeneity of weights affect dynamical processes taking place on networks. In this paper, we present a family of weighted expanded Koch networks based on Koch networks. They originate from a r-polygon, and each node of current generation produces m r-polygons including the node and whose weighted edges are scaled by factor w in subsequent evolutionary step. We derive closed-form expressions for average weighted shortest path length (AWSP). In large network, AWSP stays bounded with network order growing (0 < w < 1). Then, we focus on a special random walks and trapping issue on the networks. In more detail, we calculate exactly the average receiving time (ART). ART exhibits a sub-linear dependence on network order (0 < w < 1), which implies that nontrivial weighted expanded Koch networks are more efficient than un-weighted expanded Koch networks in receiving information. Besides, efficiency of receiving information at hub nodes is also dependent on parameters m and r. These findings may pave the way for controlling information transportation on general weighted networks.

Average spectral power changes at the hippocampal electroencephalogram in schizophrenia model induced by ketamine.

PubMed

Sampaio, Luis Rafael L; Borges, Lucas T N; Silva, Joyse M F; de Andrade, Francisca Roselin O; Barbosa, Talita M; Oliveira, Tatiana Q; Macedo, Danielle; Lima, Ricardo F; Dantas, Leonardo P; Patrocinio, Manoel Cláudio A; do Vale, Otoni C; Vasconcelos, Silvânia M M

2018-02-01

The use of ketamine (Ket) as a pharmacological model of schizophrenia is an important tool for understanding the main mechanisms of glutamatergic regulated neural oscillations. Thus, the aim of the current study was to evaluate Ket-induced changes in the average spectral power using the hippocampal quantitative electroencephalography (QEEG). To this end, male Wistar rats were submitted to a stereotactic surgery for the implantation of an electrode in the right hippocampus. After three days, the animals were divided into four groups that were treated for 10 consecutive days with Ket (10, 50, or 100 mg/kg). Brainwaves were captured on the 1st or 10th day, respectively, to acute or repeated treatments. The administration of Ket (10, 50, or 100 mg/kg), compared with controls, induced changes in the hippocampal average spectral power of delta, theta, alpha, gamma low or high waves, after acute or repeated treatments. Therefore, based on the alterations in the average spectral power of hippocampal waves induced by Ket, our findings might provide a basis for the use of hippocampal QEEG in animal models of schizophrenia. © 2017 Société Française de Pharmacologie et de Thérapeutique.

Active control of ECCD-induced tearing mode stabilization in coupled NIMROD/GENRAY HPC simulations

NASA Astrophysics Data System (ADS)

Jenkins, Thomas; Kruger, Scott; Held, Eric

2013-10-01

Actively controlled ECCD applied in or near magnetic islands formed by NTMs has been successfully shown to control/suppress these modes, despite uncertainties in island O-point locations (where induced current is most stabilizing) relative to the RF deposition region. Integrated numerical models of the mode stabilization process can resolve these uncertainties and augment experimental efforts to determine optimal ITER NTM stabilization strategies. The advanced SWIM model incorporates RF effects in the equations/closures of extended MHD as 3D (not toroidal or bounce-averaged) quasilinear diffusion coefficients. Equilibration of driven current within the island geometry is modeled using the same extended MHD dynamics governing the physics of island formation, yielding a more accurate/self-consistent picture of island response to RF drive. Additionally, a numerical active feedback control system gathers data from synthetic diagnostics to dynamically trigger & spatially align the RF fields. Computations which model the RF deposition using ray tracing, assemble the 3D QL operator from ray & profile data, calculate the resultant xMHD forces, and dynamically realign the RF to more efficiently stabilize modes are presented; the efficacy of various control strategies is also discussed. Supported by the SciDAC Center for Extended MHD Modeling (CEMM); see also https://cswim.org.

Stimulus driver for epilepsy seizure suppression with adaptive loading impedance

NASA Astrophysics Data System (ADS)

Ker, Ming-Dou; Lin, Chun-Yu; Chen, Wei-Ling

2011-10-01

A stimulus driver circuit for a micro-stimulator used in an implantable device is presented in this paper. For epileptic seizure control, the target of the driver was to output 30 µA stimulus currents when the electrode impedance varied between 20 and 200 kΩ. The driver, which consisted of the output stage, control block and adaptor, was integrated in a single chip. The averaged power consumption of the stimulus driver was 0.24-0.56 mW at 800 Hz stimulation rate. Fabricated in a 0.35 µm 3.3 V/24 V CMOS process and applied to a closed-loop epileptic seizure monitoring and controlling system, the proposed design has been successfully verified in the experimental results of Long-Evans rats with epileptic seizures.

Quantification of photocatalytic oxygenation of human blood.

PubMed

Subrahmanyam, Aryasomayajula; Thangaraj, Paul R; Kanuru, Chandrasekhar; Jayakumar, Albert; Gopal, Jayashree

2014-04-01

Photocatalytic oxygenation of human blood is an emerging concept based on the principle of photocatalytic splitting of water into oxygen and hydrogen. This communication reports: (i) a design of a photocatalytic cell (PC) that separates the blood from UV (incident) radiation source, (ii) a pH, temperature and flow controlled circuit designed for quantifying the oxygenation of human blood by photocatalysis and (iii) measuring the current efficacy of ITO/TiO2 nano thin films in oxygenating human blood in a dynamic circuit in real time. The average increase in oxygen saturation was around 5% above baseline compared to control (p<0.0005). We believe this is one of the first attempts to quantify photocatalytic oxygenation of human blood under controlled conditions. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Real-Time Flight Envelope Monitoring System

NASA Technical Reports Server (NTRS)

Kerho, Michael; Bragg, Michael B.; Ansell, Phillip J.

2012-01-01

The objective of this effort was to show that real-time aircraft control-surface hinge-moment information could be used to provide a robust and reliable prediction of vehicle performance and control authority degradation. For a given airfoil section with a control surface -- be it a wing with an aileron, rudder, or elevator -- the control-surface hinge moment is sensitive to the aerodynamic characteristics of the section. As a result, changes in the aerodynamics of the section due to angle-of-attack or environmental effects such as icing, heavy rain, surface contaminants, bird strikes, or battle damage will affect the control surface hinge moment. These changes include both the magnitude of the hinge moment and its sign in a time-averaged sense, and the variation of the hinge moment with time. The current program attempts to take the real-time hinge moment information from the aircraft control surfaces and develop a system to predict aircraft envelope boundaries across a range of conditions, alerting the flight crew to reductions in aircraft controllability and flight boundaries.

The effect of an organizational level participatory intervention in secondary vocational education on work-related health outcomes: results of a controlled trial.

PubMed

Schelvis, Roosmarijn M C; Wiezer, Noortje M; van der Beek, Allard J; Twisk, Jos W R; Bohlmeijer, Ernst T; Oude Hengel, Karen M

2017-01-31

Work-related stress is highly prevalent in the educational sector. The aim of the current study was to evaluate the effectiveness of an organizational level, participatory intervention on need for recovery and vitality in educational workers. It was hypothesized that the intervention would decrease need for recovery and increase vitality. A quasi-experiment was conducted at two secondary Vocational Education and Training schools (N = 356) with 12- and 24-months follow-up measurements. The intervention consisted of 1) a needs assessment phase, wherein staff and teachers developed actions for happy and healthy working under supervision of a facilitator, and 2) an implementation phase, wherein these actions were implemented by the management teams. Mixed model analysis was applied in order to assess the differences between the intervention and control group on average over time. All analyses were corrected for baseline values and several covariates. No effects of the intervention were found on need for recovery, vitality and most of the secondary outcomes. Two small, statistically significant effects were in unfavorable direction: the intervention group scored on average over time significantly lower on absorption (i.e. a subscale of work engagement) and organizational efficacy than the control group. Since no beneficial effects of this intervention were found on the primary and most of the secondary outcomes, further implementation of the intervention in its current form is not eligible. We recommend that future organizational level interventions for occupational health 1) incorporate an elaborate implementation strategy, 2) are more specific in relating actions to stressors in the context, and 3) are integrated with secondary preventive, individual focused stress management interventions. Netherlands Trial Register NTR3284 (date registered: February 14 2012).

Tools for assessing kinship, population structure, phylogeography, and interspecific hybridization in Asian carps invasive to the Mississippi River, USA: isolation and characterization of novel tetranucleotide microsatellite DNA loci in silver carp Hypophthalmichthys molitrix

USGS Publications Warehouse

King, T.L.; Eackles, M.S.; Chapman, D.C.

2011-01-01

We document the isolation and characterization of novel tetranucleotide microsatellite DNA markers for the invasive silver carp Hypophthalmichthys molitrix and provide the results of cross-species amplification for three additional invasive carp species: bighead (H. nobilis), grass (Ctenopharyngodon idella) and black (Mylopharyngodon piceus). In the target species these markers yielded levels of allelic diversity (average 4.4 alleles/locus) and heterozygosity (average 54.7%) sufficient to: (1) provide unique multilocus genotypes; (2) delineate kinship relationships; (3) differentiate populations/species; (4) estimate effective population sizes; and (5) provide unique demographic perspectives for control or eradication. Currently these markers are being utilized to determine the degree of introgressive hybridization between H. molitrix and H. nobilis, to quantify gene flow between different sub-basins established in the central United States, and to assess the demographic status of sub-basin groups. This information will be critically important in the management/control of these invasive species.

Evidence for developmental thermal acclimation in the damselfish, Pomacentrus moluccensis

NASA Astrophysics Data System (ADS)

Grenchik, M. K.; Donelson, J. M.; Munday, P. L.

2013-03-01

Tropical species are predicted to have limited capacity for acclimation to global warming. This study investigated the potential for developmental thermal acclimation by the tropical damselfish Pomacentrus moluccensis to ocean temperatures predicted to occur over the next 50-100 years. Newly settled juveniles were reared for 4 months in four temperature treatments, consisting of the current-day summer average (28.5 °C) and up to 3 °C above the average (29.5, 30.5 and 31.5 °C). Resting metabolic rate (RMR) of fish reared at 29.5 and 31.5 °C was significantly higher than the control group reared at 28.5 °C. In contrast, RMR of fish reared at 30.5 °C was not significantly different from the control group, indicating these fish had acclimated to their rearing temperature. Furthermore, fish that developed in 30.5 and 31.5 °C exhibited an enhanced ability to deal with acute temperature increases. These findings illustrate that developmental acclimation may help coral reef fish cope with warming ocean temperatures.

Capacitance-level/density monitor for fluidized-bed combustor

DOEpatents

Fasching, George E.; Utt, Carroll E.

1982-01-01

A multiple segment three-terminal type capacitance probe with segment selection, capacitance detection and compensation circuitry and read-out control for level/density measurements in a fluidized-bed vessel is provided. The probe is driven at a high excitation frequency of up to 50 kHz to sense quadrature (capacitive) current related to probe/vessel capacitance while being relatively insensitive to the resistance current component. Compensation circuitry is provided for generating a negative current of equal magnitude to cancel out only the resistive component current. Clock-operated control circuitry separately selects the probe segments in a predetermined order for detecting and storing this capacitance measurement. The selected segment acts as a guarded electrode and is connected to the read-out circuitry while all unselected segments are connected to the probe body, which together form the probe guard electrode. The selected probe segment capacitance component signal is directed to a corresponding segment channel sample and hold circuit dedicated to that segment to store the signal derived from that segment. This provides parallel outputs for display, computer input, etc., for the detected capacitance values. The rate of segment sampling may be varied to either monitor the dynamic density profile of the bed (high sampling rate) or monitor average bed characteristics (slower sampling rate).

Assessment of arsenic exposures and controls in gallium arsenide production.

PubMed

Sheehy, J W; Jones, J H

1993-02-01

The electronics industry is expanding the use of gallium arsenide in the production of optoelectronic devices and integrated circuits. Workers in the electronics industry using gallium arsenide are exposed to hazardous substances such as arsenic, arsine, and various acids. Arsenic requires stringent controls to minimize exposures (the current OSHA PEL for arsenic is 10 micrograms/m3 and the NIOSH REL is 2 micrograms/m3 ceiling). Inorganic arsenic is strongly implicated in respiratory tract and skin cancer. For these reasons, NIOSH researchers conducted a study of control systems for facilities using gallium arsenide. Seven walk-through surveys were performed to identify locations for detailed study which appeared to have effective controls; three facilities were chosen for in-depth evaluation. The controls were evaluated by industrial hygiene sampling. Including personal breathing zone and area air sampling for arsenic and arsine; wipe samples for arsenic also were collected. Work practices and the use of personal protective equipment were documented. This paper reports on the controls and the arsenic exposure results from the evaluation of the following gallium arsenide processes: Liquid Encapsulated Czochralski (LEC) and Horizontal Bridgeman (HB) crystal growing, LEC cleaning operations, ingot grinding/wafer sawing, and epitaxy. Results at one plant showed that in all processes except epitaxy, average arsenic exposures were at or above the OSHA action level of 5 micrograms/m3. While cleaning the LEC crystal pullers, the average potential arsenic exposure of the cleaning operators was 100 times the OSHA PEL. At the other two plants, personal exposures for arsenic were well controlled in LEC, LEC cleaning, grinding/sawing, and epitaxy operations.

Child-Langmuir flow with periodically varying anode voltage

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

Rokhlenko, A.

Using the Lagrangian technique, we study settled Child-Langmuir flows in a one dimensional planar diodes whose anode voltages periodically vary around given positive values. Our goal is to find analytically if the average currents in these systems can exceed the famous Child-Langmuir limit found for the stationary current a long time ago. The main result of our study is that in a periodic quasi-stationary regime the average current can be larger than the Child-Langmuir maximum even by 50% compared with its adiabatic average value. The cathode current in this case has the form of rectangular pulses which are formed bymore » a very special triangular voltage modulation. This regime, i.e., periodicity, shape of pulses, and their amplitude, needs to be carefully chosen for the best performance.« less

Infection prevention staffing and resources in U.S. acute care hospitals: Results from the APIC MegaSurvey.

PubMed

Pogorzelska-Maziarz, Monika; Gilmartin, Heather; Reese, Sara

2018-06-01

Given the changing nature of infection prevention and control (IPC), appropriate infection preventionist (IP) staffing needs to be established. In this study, we aimed to describe current IP staffing levels and IPC department resources in U.S. acute care hospitals. These data came from the 2015 MegaSurvey conducted by the Association of Professionals in Infection Prevention and Epidemiology. Descriptive statistics and bivariate analyses were conducted to examine differences in respondent, facility, and department characteristics by facility size (average inpatient census ≤100 vs >100). Data from 1623 respondents were included. Most (72%) had single-site responsibilities and dedicated 76%-100% of their job to IPC (68%). The overall median IP staffing was 1.25 IPs per 100 inpatient census (interquartile range = 1.81). Almost half (46%) represented facilities with daily inpatient census ≤100; the average number of IPs in these facilities was 1.1 (standard deviation = 0.7). The reported number of IPs increased steadily with higher patient census. Significant differences were observed in IP staffing, responsibilities, and support to the IPC department between smaller and larger hospitals. This study represents the current snapshot of IP staffing and IPC resources in acute care hospitals. Findings indicate important differences between large and small facilities in staffing and IPC resources. The field of infection prevention would benefit from a comprehensive assessment of IPC department staffing and resource needs. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. All rights reserved.

Time delay between the SYMH and the solar wind energy input during intense storms determined by response function analysis

NASA Astrophysics Data System (ADS)

Cao, X.; Du, A.

2014-12-01

We statistically studied the response time of the SYMH to the solar wind energy input ɛ by using the RFA approach. The average response time was 64 minutes. There was no clear trend among these events concerning to the minimum SYMH and storm type. It seems that the response time of magnetosphere to the solar wind energy input is independent on the storm intensity and the solar wind condition. The response function shows one peak even when the solar wind energy input and the SYMH have multi-peak. The response time exhibits as the intrinsic property of the magnetosphere that stands for the typical formation time of the ring current. This may be controlled by magnetospheric temperature, average number density, the oxygen abundance et al.

Novel pulsed switched power supply for a fast field cycling NMR spectrometer.

PubMed

Sousa, D M; Fernandes, P A L; Marques, G D; Ribeiro, A C; Sebastião, P J

2004-01-01

In this paper, we outline the operating principles of a pulsed switched power supply for a fast field-cycling nuclear magnetic resonance spectrometer. The power supply uses a variant of a four-quadrant chopper with a duty cycle that defines the average output current. With this topology only two semiconductors are necessary to drive hundreds of amperes with an output power of several kilowatts. The output current ripple has a well-defined shape that can be reduced to acceptable values by a careful design of the semiconductors' controlling circuits and drivers. A power supply prototype was tested with a home build air-core magnet operating with fields between 0 and 0.21 T. The system is computer controlled using pulse generator and data acquisition PC cards, and specific user-friendly home-developed software. A comparative proton relaxometry study in two well-known liquid crystal compounds 5CB and MBBA was performed to check the reproducibility of the T1 measurements.

Effects of an intervention aimed at reducing the intake of sugar-sweetened beverages in primary school children: a controlled trial.

PubMed

van de Gaar, Vivian M; Jansen, Wilma; van Grieken, Amy; Borsboom, Gerard J J M; Kremers, Stef; Raat, Hein

2014-07-25

Since sugar-sweetened beverages (SSB) may contribute to the development of overweight in children, effective interventions to reduce their consumption are needed. Here we evaluated the effect of a combined school- and community-based intervention aimed at reducing children's SSB consumption by promoting the intake of water. Favourable intervention effects on children's SSB consumption were hypothesized. In 2011-2012, a controlled trial was conducted among four primary schools, comprising 1288 children aged 6-12 years who lived in multi-ethnic, socially deprived neighbourhoods in Rotterdam, the Netherlands. Intervention schools adopted the 'water campaign', an intervention developed using social marketing. Control schools continued with their regular health promotion programme. Primary outcome was children's SSB consumption, measured using parent and child questionnaires and through observations at school, both at baseline and after one year of intervention. Significant positive intervention effects were found for average SSB consumption (B -0.19 litres, 95% CI -0.28;-0.10; parent report), average SSB servings (B -0.54 servings, 95% CI -0.82;-0.26; parent report) and bringing SSB to school (OR 0.51, 95% CI 0.36;0.72; observation report). This study supports the effectiveness of the water campaign intervention in reducing children's SSB consumption. Further studies are needed to replicate our findings. Current Controlled Trials: NTR3400.

Effects and Safety of Gyejibongnyeong-Hwan on Dysmenorrhea Caused by Blood Stagnation: A Randomized Controlled Trial

PubMed Central

Park, Jeong-Su; Park, Sunju; Cheon, Chun-Hoo; Jo, Seong-Cheon; Cho, Han Baek; Lim, Eun-Mee; Lim, Hyung Ho; Shin, Yong-Cheol; Ko, Seong-Gyu

2013-01-01

Objective. This study was a multicenter, randomized, double-blind, and controlled trial with two parallel arms: the GJBNH group and the placebo group. This trial recruited 100 women aging 18 to 35 years with primary dysmenorrhea caused by blood stagnation. The investigational drugs, GJBNH or placebo, were administered for two menstrual periods (8 weeks) to the participants three times per day. The participants were followed up for two menstrual cycles after the administration. Results. The results were analyzed by the intention-to-treat (ITT) dataset and the per-protocol (PP) dataset. In the ITT dataset, the change of the average menstrual pain VAS score in the GJBNH group was statistically significantly lower than that in the control group. Significant difference was not observed in the SF-MPQ score change between the GJBNH group and the placebo group. No significant difference was observed in the PP analyses. In the follow-up phase, the VAS scores of the average menstrual pain and the maximum menstrual pain continually decreased in the placebo group, but they increased in the GJBNH group. Conclusion. GJBNH treatment for eight weeks improved the pain of the dysmenorrhea caused by blood stagnation, but it should be successively administered for more than two menstrual cycles. Trial Registration. This trial is registered with Current Controlled Trials no. ISRCTN30426947. PMID:24191165

Lower Sodium Intake and Risk of Headaches: Results From the Trial of Nonpharmacologic Interventions in the Elderly

PubMed Central

Chen, Liwei; Zhang, Zhenzhen; Chen, Wen; Whelton, Paul K.; Appel, Lawrence J.

2016-01-01

Objectives To determine the effect of sodium (Na) reduction on occurrence of headaches. Methods In the Trial of Nonpharmacologic Interventions in the Elderly, 975 men and woman (aged 60–80 years) with hypertension were randomized to a Na-reduction intervention or control group and were followed for up to 36 months. The study was conducted between 1992 and 1995 at 4 clinical centers (Johns Hopkins University, Wake Forest University School of Medicine, Robert Wood Johnson Medical School, and the University of Tennessee). Results Mean difference in Na excretion between the Na-reduction intervention and control group was significant at each follow-up visit (P < .001) with an average difference of 38.8 millimoles per 24 hours. The occurrence of headaches was significantly lower in the Na-reduction intervention group (10.5%) compared with control (14.3%) with a hazard ratio of 0.59 (95% confidence interval = 0.40, 0.88; P = .009). The risk of headaches was significantly associated with average level of Na excretion during follow-up, independent of most recent blood pressure. The relationship appeared to be nonlinear with a spline relationship and a knot at 150 millimoles per 24 hours. Conclusions Reduced sodium intake, currently recommended for blood pressure control, may also reduce the occurrence of headaches in older persons with hypertension. PMID:27077348

Alternate charging and discharging of capacitor to enhance the electron production of bioelectrochemical systems.

PubMed

Liang, Peng; Wu, Wenlong; Wei, Jincheng; Yuan, Lulu; Xia, Xue; Huang, Xia

2011-08-01

A bioelectrochemical system (BES) can be operated in both "microbial fuel cell" (MFC) and "microbial electrolysis cell" (MEC) modes, in which power is delivered and invested respectively. To enhance the electric current production, a BES was operated in MFC mode first and a capacitor was used to collect power from the system. Then the charged capacitor discharged electrons to the system itself, switching into MEC mode. This alternate charging and discharging (ACD) mode helped the system produce 22-32% higher average current compared to an intermittent charging (IC) mode, in which the capacitor was first charged from an MFC and then discharged to a resistor, at 21.6 Ω external resistance, 3.3 F capacitance and 300 mV charging voltage. The effects of external resistance, capacitance and charging voltage on average current were studied. The average current reduced as the external resistance and charging voltage increased and was slightly affected by the capacitance. Acquisition of higher average current in the ACD mode was attributed to the shorter discharging time compared to the charging time, as well as a higher anode potential caused by discharging the capacitor. Results from circuit analysis and quantitatively calculation were consistent with the experimental observations.

Local noise in a diffusive conductor

PubMed Central

Tikhonov, E. S.; Shovkun, D. V.; Ercolani, D.; Rossella, F.; Rocci, M.; Sorba, L.; Roddaro, S.; Khrapai, V. S.

2016-01-01

The control and measurement of local non-equilibrium configurations is of utmost importance in applications on energy harvesting, thermoelectrics and heat management in nano-electronics. This challenging task can be achieved with the help of various local probes, prominent examples including superconducting or quantum dot based tunnel junctions, classical and quantum resistors, and Raman thermography. Beyond time-averaged properties, valuable information can also be gained from spontaneous fluctuations of current (noise). From these perspective, however, a fundamental constraint is set by current conservation, which makes noise a characteristic of the whole conductor, rather than some part of it. Here we demonstrate how to remove this obstacle and pick up a local noise temperature of a current biased diffusive conductor with the help of a miniature noise probe. This approach is virtually noninvasive for the electronic energy distributions and extends primary local measurements towards strongly non-equilibrium regimes. PMID:27466216

Local noise in a diffusive conductor

NASA Astrophysics Data System (ADS)

Tikhonov, E. S.; Shovkun, D. V.; Ercolani, D.; Rossella, F.; Rocci, M.; Sorba, L.; Roddaro, S.; Khrapai, V. S.

2016-07-01

The control and measurement of local non-equilibrium configurations is of utmost importance in applications on energy harvesting, thermoelectrics and heat management in nano-electronics. This challenging task can be achieved with the help of various local probes, prominent examples including superconducting or quantum dot based tunnel junctions, classical and quantum resistors, and Raman thermography. Beyond time-averaged properties, valuable information can also be gained from spontaneous fluctuations of current (noise). From these perspective, however, a fundamental constraint is set by current conservation, which makes noise a characteristic of the whole conductor, rather than some part of it. Here we demonstrate how to remove this obstacle and pick up a local noise temperature of a current biased diffusive conductor with the help of a miniature noise probe. This approach is virtually noninvasive for the electronic energy distributions and extends primary local measurements towards strongly non-equilibrium regimes.

How Can Paresthesia After Zygomaticomaxillary Complex Fracture Be Determined After Long-Term Follow-Up? A New and Quantitative Evaluation Method Using Current Perception Threshold Testing.

PubMed

Okochi, Masayuki; Ueda, Kazuki; Mochizuki, Yasushi; Okochi, Hiromi

2015-08-01

The aims of the present study were to analyze the effectiveness of current perception threshold (CPT) testing to determine patients' minor paresthesia of the infraorbital region after open reduction and internal fixation (ORIF) for unilateral zygomaticomaxillary bone fracture (UZF) and to clarify which nerve fiber was related to the paresthesia. We conducted a retrospective cohort study of patients who had undergone ORIF after UZF. We also performed neurosensory testing for healthy volunteers who served as the control group. The predictor variables were the period of measurement of Semmes-Weinstein monofilament (S-W) testing and CPT testing (preoperatively and 1 and 5 years postoperatively), measurement side, and disease status (UZF or control). The outcome variables were paresthesia status of the infraorbital nerve region and the results of S-W and CPT testing in both UZF and control groups. The differences in the S-W and CPT values between the affected and unaffected sides in the UZF group and between the UZF and control groups were analyzed by t test (P < .05 was considered significant). The present study included 10 patients (6 males and 4 females), with an average age of 25.0 ± 12.7 years, and 21 controls (10 males and 11 females), with an average age of 24.3 ± 1.7 years. In the control group, the CPT and S-W test results did not show any significant differences between the left and right sides. All 10 patients had paresthesia at 1 and 5 years postoperatively. At 5 years postoperatively, the S-W values in all patients showed normalization. From the results of CPT testing, only the A-β fiber function showed significant improvement at 5 years postoperatively. The CPT test was an effective sensory test for determining minor paresthesia that could not be detected using S-W testing. Paresthesia of the infraorbital nerve region was caused by the damaged A-δ and C fibers. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

[Research on competency building standards of institutions of schistosomiasis prevention and control in Hubei Province I Investigation of institution management].

PubMed

Liu, Han-cheng; Zhong, Chen-hui; Liao, Si-qi; He, Hui

2014-08-01

To investigate the current situation of management of institutions of schistosomiasis prevention and control in Hubei Province, so as to explore the probable competency building standards for these institutions at the county and township levels. By using a combination of quantitative and qualitative methods, the institutions of schistosomiasis prevention and control at county and township levels were investigated for the institutional setup, staffing and fulfillment functions since the reform of 2004. Among 63 schistosomiasis endemic counties (cities, districts) of Hubei Province, there were 26 independent schistosomiasis control institutions (41.27%), there were 24 institutions which were incorporated into CDC (38.10%), and there were no institutions in 13 counties (20.63%). Among 518 endemic towns, there were 299 institutions (57.72%). The total staffing size were 1 932, but there were 1 586 (82.09%) people actually working in the post, and therefore there were 346 (17.91%) empty positions. The average rates of carrying out the six functions were 91.48%-71.19%, but only 19.23% of the institutions participated in the comprehensive schistosomiasis control management project and its effect assessment. According to the management model for schistosomiasis control institutions under the current institutional mechanisms, we need a rigorous industry standard to constrain, guide and standardize the management and capacity-building of the institutions in different historical periods.

Summary of Resources for the International Space Station Environmental Control and Life Support System

NASA Technical Reports Server (NTRS)

Williams, David E.

2003-01-01

The assembly complete Environmental Control and Life Support (ECLS) s ystem for the International Space Station (ISS) will consist of compo nents and subsystems in both the U.S. and International partner eleme nts which together will perform the functions of Temperature and Hum idity Control (THC), Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Water Recovery and Management (WRM), Fire Detect ion and Suppression (FDS), and Vacuum System (VS) for the station. D ue to limited resources available on ISS, detailed attention is given to minimizing and tracking all resources associated with all systems , beginning with estimates during the hardware development phase thr ough measured actuals when flight hardware is built and delivered. A summary of resources consumed by the current on-orbit U.S. ECLS syste m hardware is presented, including launch weight, average continuous and peak power loads, on-orbit volume and resupply logistics. ..

EV drivetrain inverter with V/HZ optimization

DOEpatents

Gritter, David J.; O'Neil, Walter K.

1986-01-01

An inverter (34) which provides power to an A.C. machine (28) is controlled by a circuit (36) employing PWM control strategy whereby A.C. power is supplied to the machine at a preselectable frequency and preselectable voltage. This is accomplished by the technique of waveform notching in which the shapes of the notches are varied to determine the average energy content of the overall waveform. Through this arrangement, the operational efficiency of the A.C. machine is optimized. The control circuit includes a micro-computer which calculates optimized machine control data signals from various parametric inputs and during steady state load conditions, seeks a best V/HZ ratio to minimize battery current drawn (system losses) from a D.C. power source (32). In the preferred embodiment, the present invention is incorporated within an electric vehicle (10) employing a 144 VDC battery pack and a three-phase induction motor (18).

The descriptive epidemiology of DSM-IV Adult ADHD in the World Health Organization World Mental Health Surveys

PubMed Central

Fayyad, John; Sampson, Nancy A.; Hwang, Irving; Adamowski, Tomasz; Aguilar-Gaxiola, Sergio; Al-Hamzawi, Ali; Andrade, Laura H. S. G.; Borges, Guilherme; de Girolamo, Giovanni; Florescu, Silvia; Gureje, Oye; Haro, Josep Maria; Hu, Chiyi; Karam, Elie G.; Lee, Sing; Navarro-Mateu, Fernando; O’Neill, Siobhan; Pennell, Beth-Ellen; Piazza, Marina; Posada-Villa, José; Have, Margreet ten; Torres, Yolanda; Xavier, Miguel; Zaslavsky, Alan M.; Kessler, Ronald C.

2017-01-01

We previously reported on the cross-national epidemiology of ADHD from the first 10 countries in the WHO World Mental Health (WMH) Surveys. The current report expands those previous findings to the 20 nationally or regionally representative WMH surveys that have now collected data on adult ADHD. The Composite International Diagnostic Interview (CIDI) was administered to 26,744 respondents in these surveys in high-, upper-middle-, and low-/lower-middle-income countries (68.5% mean response rate). Current DSM-IV/CIDI adult ADHD prevalence averaged 2.8% across surveys and was higher in high (3.6%)- and upper-middle (3.0%)- than low-/lower-middle (1.4%)-income countries. Conditional prevalence of current ADHD averaged 57.0% among childhood cases and 41.1% among childhood subthreshold cases. Adult ADHD was significantly related to being male, previously married, and low education. Adult ADHD was highly comorbid with DSM-IV/CIDI anxiety, mood, behavior, and substance disorders and significantly associated with role impairments (days out of role, impaired cognition, and social interactions) when controlling for comorbidities. Treatment seeking was low in all countries and targeted largely to comorbid conditions rather than to ADHD. These results show that adult ADHD is prevalent, seriously impairing, and highly comorbid but vastly under-recognized and undertreated across countries and cultures. PMID:27866355

Characteristics of the most intense lightning storm ever recorded at the CN Tower

NASA Astrophysics Data System (ADS)

Hussein, A. M.; Kazazi, S.; Anwar, M.; Yusouf, M.; Liatos, P.

2017-02-01

Lightning strikes to the CN Tower have been optically observed since 1978. In 1990, five independent systems started to operate to simultaneously record parameters of lightning strikes to the tower, including the time derivative of the current, the associated electric and magnetic fields, and the channel optical characteristics. On August 24, 2011, during an unusually severe lightning storm, video records showed that the CN Tower was struck with 52 lightning flashes within 84 min and 6.9 s. Thus, this storm produced, on average, a flash to the tower every 99 s. However, the CN Tower lightning current derivative measurement system only recorded 32 flashes, which were perfectly time-matched with 32 of the 52 video-recorded flashes. It is found that the current derivative measurement system recorded every video-recorded flash that contained at least one return stroke. Based on the analysis of video records, it is noted that each of the storm's 52 flashes contains an initial-stage current, proving that all flashes were upward initiated. This unique CN Tower storm - the most intense ever recorded at the tower - is here thoroughly analyzed, based on video and current records. The inter-flash time within the storm is found to vary between 10.6 s and 274 s, with an overall average of 98 s. It is also found that the inter-flash time between successive non-return-stroke flashes is on average 64% longer than that for successive flashes containing return strokes. Statistical analysis of video and current data clearly reveals that the time duration of flashes containing initial-stage currents and return strokes is on average 27% longer than that of flashes that only have initial-stage currents. Furthermore, it is important to note that the time duration of the initial-stage current in flashes containing no return strokes is on average 76% longer than that in flashes containing return strokes. Therefore, it is possible to conclude that if the time duration of the initial-stage current in a flash is long enough, resulting in large charge transfer, then there is less probability of having return strokes following it. The 32 current-recorded flashes contain a total of 156 return strokes, with an average multiplicity of 4.875. It is worth mentioning that during one decade, 1992-2001, the CN Tower current derivative measurement system only recorded 478 return strokes, demonstrating that the number of return strokes recorded at the tower within about 84 min is close to one third of those recorded at the tower during one decade. This finding clearly shows the great value and rarity of the presented extensive lightning current derivative data. Only one of the 32 current-recorded flashes is proved to be positive with a single return stroke. Based on current records, out of a total of 124 inter-stroke time intervals, 94% are found to be within 200 ms, with an overall inter-stroke time average of 68.1 ms. The maximum inter-stroke time recorded during this storm is 726.3 ms, the longest ever recorded at the CN Tower.

Dynamic balance in elite karateka.

PubMed

Zago, Matteo; Mapelli, Andrea; Shirai, Yuri Francesca; Ciprandi, Daniela; Lovecchio, Nicola; Galvani, Christel; Sforza, Chiarella

2015-12-01

In karate, balance control represents a key performance determinant. With the hypothesis that high-level athletes display advanced balance abilities, the purpose of the current study was to quantitatively investigate the motor strategies adopted by elite and non-elite karateka to maintain balance control in competition. The execution of traditional karate techniques (kihon) in two groups of elite Masters (n = 6, 31 ± 19 years) and non-elite Practitioners (n = 4, 25 ± 9 years) was compared assessing body center of mass (CoM) kinematics and other relevant parameters like step width and angular joint behavior. In the considered kihon sequence, normalized average CoM height was 8% lower (p < 0.05), while CoM displacement in the horizontal direction was significantly higher in Masters than in Practitioners (2.5 vs. 1.9 m, p < 0.05), as well as CoM average velocity and rms acceleration (p < 0.05). Step width was higher in Masters in more than half of the sequence steps (p < 0.05). Results suggest that elite karateka showed a refined dynamic balance control, obtained through the increase of the base of support and different maneuvers of lower limbs. The proposed method could be used to objectively detect talented karateka, to measure proficiency level and to assess training effectiveness. Copyright © 2015 Elsevier Ltd. All rights reserved.

Safety, efficacy, and patient acceptability of lidocaine hydrochloride ophthalmic gel as a topical ocular anesthetic for use in ophthalmic procedures

PubMed Central

Page, Michael A; Fraunfelder, Frederick W

2009-01-01

Purpose: To review the current literature on safety, efficacy, and measures of surgeon and patient satisfaction with lidocaine hydrochloride gel as a tool for ocular anesthesia. Methods: Pubmed search using keywords “lidocaine gel,” “ophthalmic,” and “surgery” and compiling cross-references. Twenty-six total references were reviewed, including 15 prospective randomized controlled trials (RCTs, total N = 933, average N = 62), 6 nonrandomized prospective studies (total N = 234, average N = 39), 2 animal studies, 1 microbiologic study, and 2 letters to the editor. Results: The RCTs and nonrandomized prospective studies evaluated a number of measures including timing of onset of anesthesia, duration of anesthesia, intraoperative and postoperative pain, need for additional anesthetic applications, intracameral lidocaine levels, and adverse effects. Control groups received topical drops, subconjunctival anesthetic, retrobulbar anesthetic, or sham gel. Lidocaine gel was shown to be at least as effective for pain control as alternative therapies in all studies, with longer duration of action than topical drops. Patient and surgeon satisfaction were high, and adverse effects were rare and comparable to those for anesthetic drop formulations. Surgical settings included cataract, pterygium, trabeculectomy, strabismus, intravitreal injection, vitrectomy, and penetrating keratoplasty. Conclusions: Lidocaine gel is a safe, effective, and potentially underutilized tool for ophthalmic surgery. PMID:19898665

Biomass of Spirulina maxima enriched by biosorption process as a new feed supplement for swine.

PubMed

Saeid, A; Chojnacka, K; Korczyński, M; Korniewicz, D; Dobrzański, Z

2013-04-01

This paper deals with the new mineral feed additives with Cu produced in a biosorption process from a semi-technical scale. The natural biomass of edible microalga Spirulina sp. was enriched with Cu(II) and then used as a mineral supplement in feeding experiments on swine to assess its nutrition properties. A total of 24 piglets divided into two groups (control and experimental) were used to determine the bioavailability of a new generation of mineral feed additives based on Spirulina maxima . The control group was feed using traditional inorganic supplements of microelements, while the experimental group was fed with the feed containing the biomass of S. maxima enriched with Cu by biosorption. The apparent absorption was 30 % ( P  < 0.05) higher in the experimental group. No effect on the production results (average daily feed intake, average daily gain, feed conversion ratio) was detected. It was found that copper concentration in feces in the experimental group was 60 % ( P  < 0.05) lower than in the control group. The new preparation-a dietary supplement with microelements produced by biosorption based on biomass of microalgae S. maxima -is a promising alternative to currently used inorganic salts as the source of nutritionally important microelements.

Digital ac monitor

DOEpatents

Hart, George W.; Kern, Jr., Edward C.

1987-06-09

An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer.

Digital ac monitor

DOEpatents

Hart, G.W.; Kern, E.C. Jr.

1987-06-09

An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer. 24 figs.

EMC Global Climate And Weather Modeling Branch Personnel

Science.gov Websites

Comparison Statistics which includes: NCEP Raw and Bias-Corrected Ensemble Domain Averaged Bias NCEP Raw and Bias-Corrected Ensemble Domain Averaged Bias Reduction (Percents) CMC Raw and Bias-Corrected Control Forecast Domain Averaged Bias CMC Raw and Bias-Corrected Control Forecast Domain Averaged Bias Reduction

Near-bottom energy cascade from subinertial flows to ocean mixing in the northeastern South China Sea

NASA Astrophysics Data System (ADS)

Zhang, Y.; Liu, Z.; Zhao, Y.; Wang, W.; Li, J.; Xu, J.

2013-12-01

The motions with different scales in the bottom boundary layer are potentially important in controlling the water mass transportation. Many physical processes are involved in transferring energy from mesoscale to small-scale motions. Recent studies suggest that subinertial flows should be taken into account in the parameterization of deep-ocean mixing besides topography and tidal forcing. Here, we present the current velocity data obtained from 2 moored downward-looking ADCPs (Acoustic Doppler Current Profiler) and 1 RCM (Recording Current Meter) moored near the bottom boundary layer at a water depth of about 2000 m in the northeastern South China Sea from 2012 to 2013. Specifically, they include an ADCP 1200 kHz deployed at 30 m, an ADCP 300 kHz deployed at 110 m, and a RCM deployed at 40 m above the seafloor. Subinertial flows were calculated from the moored current velocity data by low-pass filtering with a cutoff frequency of 0.3 cycles per day (the local inertial period is about 35 hours). The horizontal subinertial flows were quite strong with average values of 2-5 cm/s. The strong downward vertical velocity with average values of 1-2 cm/s was observed during times of weak subinertial flows. The vertical propagation during both the times of weak and strong subinertial flows can also be shown by vector spectra of horizontal near-inertial current velocity. Turbulent kinetic energy production rate estimated indirectly with the variances of ADCP velocities will be compared with the subinertial kinetic energy to detect the processes of energy cascade from mesoscale motions to small-scale oscillations. The results presented in this study can provide an observational evidence for such energy cascade near the bottom boundary layer in the deep South China Sea.

A phantom-based JAFROC observer study of two CT reconstruction methods: the search for optimisation of lesion detection and effective dose

NASA Astrophysics Data System (ADS)

Thompson, John D.; Chakraborty, Dev P.; Szczepura, Katy; Vamvakas, Ioannis; Tootell, Andrew; Manning, David J.; Hogg, Peter

2015-03-01

Purpose: To investigate the dose saving potential of iterative reconstruction (IR) in a computed tomography (CT) examination of the thorax. Materials and Methods: An anthropomorphic chest phantom containing various configurations of simulated lesions (5, 8, 10 and 12mm; +100, -630 and -800 Hounsfield Units, HU) was imaged on a modern CT system over a tube current range (20, 40, 60 and 80mA). Images were reconstructed with (IR) and filtered back projection (FBP). An ATOM 701D (CIRS, Norfolk, VA) dosimetry phantom was used to measure organ dose. Effective dose was calculated. Eleven observers (15.11+/-8.75 years of experience) completed a free response study, localizing lesions in 544 single CT image slices. A modified jackknife alternative free-response receiver operating characteristic (JAFROC) analysis was completed to look for a significant effect of two factors: reconstruction method and tube current. Alpha was set at 0.05 to control the Type I error in this study. Results: For modified JAFROC analysis of reconstruction method there was no statistically significant difference in lesion detection performance between FBP and IR when figures-of-merit were averaged over tube current (F(1,10)=0.08, p = 0.789). For tube current analysis, significant differences were revealed between multiple pairs of tube current settings (F(3,10) = 16.96, p<0.001) when averaged over image reconstruction method. Conclusion: The free-response study suggests that lesion detection can be optimized at 40mA in this phantom model, a measured effective dose of 0.97mSv. In high-contrast regions the diagnostic value of IR, compared to FBP, is less clear.

Time-averaged current analysis of a thunderstorm using ground-based measurements

NASA Astrophysics Data System (ADS)

Driscoll, Kevin T.; Blakeslee, Richard J.; Koshak, William J.

1994-05-01

The amount of upward current provided to the ionosphere by a thunderstorm that appeared over the Kennedy Space Center (KSC) on July 11, 1978, is reexamined using an analytic equation that describes a bipolar thunderstorm's current contribution to the global circuit in terms of its generator current, lightning currents, the altitudes of its charge centers, and the conductivity profile of the atmosphere. Ground-based measurements, which were obtained from a network of electric field mills positioned at various distances from the thunderstorm, were used to characterize the electrical activity inside the thundercloud. The location of the lightning discharges, the type of lightning, and the amount of charge neutralized during this thunderstorm were computed through a least squares inversion of the measured changes in the electric fields following each lightning discharge. These measurements provided the information necessary to implement the analytic equation, and consequently, a time-averaged estimate of this thunderstorm's current contribution to the global circuit was calculated. From these results the amount of conduction current supplied to the ionosphere by this small thunderstorm was computed to be less than 25% of the time-averaged generator current that flowed between the two vertically displaced charge centers.

Genome size variation in the genus Avena.

PubMed

Yan, Honghai; Martin, Sara L; Bekele, Wubishet A; Latta, Robert G; Diederichsen, Axel; Peng, Yuanying; Tinker, Nicholas A

2016-03-01

Genome size is an indicator of evolutionary distance and a metric for genome characterization. Here, we report accurate estimates of genome size in 99 accessions from 26 species of Avena. We demonstrate that the average genome size of C genome diploid species (2C = 10.26 pg) is 15% larger than that of A genome species (2C = 8.95 pg), and that this difference likely accounts for a progression of size among tetraploid species, where AB < AC < CC (average 2C = 16.76, 18.60, and 21.78 pg, respectively). All accessions from three hexaploid species with the ACD genome configuration had similar genome sizes (average 2C = 25.74 pg). Genome size was mostly consistent within species and in general agreement with current information about evolutionary distance among species. Results also suggest that most of the polyploid species in Avena have experienced genome downsizing in relation to their diploid progenitors. Genome size measurements could provide additional quality control for species identification in germplasm collections, especially in cases where diploid and polyploid species have similar morphology.

META II: Formal Co-Verification of Correctness of Large-Scale Cyber-Physical Systems During Design (Mod 0006). Volume 2

DTIC Science & Technology

2012-03-01

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YY) 2. REPORT TYPE 3. DATES COVERED (From...13. SUPPLEMENTARY NOTES Report contains color. PA Case Number: 88ABW-2012-1688; Clearance Date: 23 Mar 2012. See also Volume 1 , AFRL-RZ-WP-TR

Compressed Video Segmentation

DTIC Science & Technology

1996-09-01

Fk+gl1mGnCop![ qVa +HeU95.!:r%I>0&CFS+I,:Y45&C47%,:d&C$+&6%=( 1 (3`F-FS+/`+9597@s%8.1F:Q.18.1FS+I9V>AFG+He.: 45,(395`/=.R>t...Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per...penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE SEP 1996

Outreach and Prevention Staff Focus Guide. Building Bridges: Supporting the Psychological Health and Traumatic Brain Injury Needs of Military and Veteran Families

DTIC Science & Technology

2010-01-01

Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response...failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 2010 2. REPORT TYPE...DCoE) 6 DCoE Component Centers 8 Military OneSource 11 Military HOMEFRONT 13 Department of Defense Sexual Assault Prevention and Response Office

Advancing Stability and Reconciliation in Guinea-Bissau: Lessons from Africa’s First Narco-State

DTIC Science & Technology

2013-06-01

for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE JUN 2013 2. REPORT...simultaneously led to a near doubling in the price of rice, the country’s staple grain, two-thirds of which must be imported. Forced to spend more of...half, the military’s troop-to-population ratio remains double the West African average. According to a 2008 study (see Table 1), more than half the

Iranian Strategy in Iraq: Politics and ’Other Means’

DTIC Science & Technology

2008-10-13

and “Other Means”                      Joseph Felter  Brian Fishman      October 13, 2008 1 Report Documentation Page Form ApprovedOMB No. 0704-0188...Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions...information if it does not display a currently valid OMB control number. 1 . REPORT DATE 13 OCT 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008

Effect of positive pulse charge waveforms on cycle life of nickel-zinc cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1979-01-01

Five amp-hour nickel-zinc cells were life cycled to evaluate four different charge methods. Three of the four waveforms investigated were 120 Hz full wave rectified sinusoidal (FWRS), 120 Hz silicon controlled rectified (SCR), and 1 kHz square wave (SW). The fourth, a constant current method, was used as a baseline of comparison. Three sealed Ni-Zn cells connected in series were cycled. Each series string was charged at an average c/20 rate, and discharged at a c/2.5 rate to a 75% rated depth.

Development of a high average current polarized electron source with long cathode operational lifetime

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

C. K. Sinclair; P. A. Adderley; B. M. Dunham

Substantially more than half of the electromagnetic nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility of the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) require highly polarized electron beams, often at high average current. Spin-polarized electrons are produced by photoemission from various GaAs-based semiconductor photocathodes, using circularly polarized laser light with photon energy slightly larger than the semiconductor band gap. The photocathodes are prepared by activation of the clean semiconductor surface to negative electron affinity using cesium and oxidation. Historically, in many laboratories worldwide, these photocathodes have had short operational lifetimes at high average current, and havemore » often deteriorated fairly quickly in ultrahigh vacuum even without electron beam delivery. At Jefferson Lab, we have developed a polarized electron source in which the photocathodes degrade exceptionally slowly without electron emission, and in which ion back bombardment is the predominant mechanism limiting the operational lifetime of the cathodes during electron emission. We have reproducibly obtained cathode 1/e dark lifetimes over two years, and 1/e charge density and charge lifetimes during electron beam delivery of over 2?105???C/cm2 and 200 C, respectively. This source is able to support uninterrupted high average current polarized beam delivery to three experimental halls simultaneously for many months at a time. Many of the techniques we report here are directly applicable to the development of GaAs photoemission electron guns to deliver high average current, high brightness unpolarized beams.« less

Study of design and control of remote manipulators. Modeling manipulator arms with distributed flexibility for design and control

NASA Technical Reports Server (NTRS)

Book, W. J.

1974-01-01

The interactions of control system and distributed flexible structural dynamics is explored for mechanical arms. A modeling process using 4 x 4 transfer matrices is described which permits the closed loop response of many current arm configurations to be evaluated. Root locus, frequency response, modal shapes, and time impulse response have all been obtained from the digital computer implementation of this model, which is oriented to arm design and allows for easy variation of the arm configuration through data cards. The model corresponds with experimentally observed natural frequencies with an average error of less than 5% in the first three flexible modes in the seven cases considered. The model was used to explore the limits imposed by structural flexibility on a nondimensionalized two link arm with one and two joints for planar motion.

Active cooling of pulse compression diffraction gratings for high energy, high average power ultrafast lasers

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

Alessi, David A.; Rosso, Paul A.; Nguyen, Hoang T.

Laser energy absorption and subsequent heat removal from diffraction gratings in chirped pulse compressors poses a significant challenge in high repetition rate, high peak power laser development. In order to understand the average power limitations, we have modeled the time-resolved thermo-mechanical properties of current and advanced diffraction gratings. We have also developed and demonstrated a technique of actively cooling Petawatt scale, gold compressor gratings to operate at 600W of average power - a 15x increase over the highest average power petawatt laser currently in operation. As a result, combining this technique with low absorption multilayer dielectric gratings developed in ourmore » group would enable pulse compressors for petawatt peak power lasers operating at average powers well above 40kW.« less

Active cooling of pulse compression diffraction gratings for high energy, high average power ultrafast lasers

DOE PAGES

Alessi, David A.; Rosso, Paul A.; Nguyen, Hoang T.; ...

2016-12-26

Laser energy absorption and subsequent heat removal from diffraction gratings in chirped pulse compressors poses a significant challenge in high repetition rate, high peak power laser development. In order to understand the average power limitations, we have modeled the time-resolved thermo-mechanical properties of current and advanced diffraction gratings. We have also developed and demonstrated a technique of actively cooling Petawatt scale, gold compressor gratings to operate at 600W of average power - a 15x increase over the highest average power petawatt laser currently in operation. As a result, combining this technique with low absorption multilayer dielectric gratings developed in ourmore » group would enable pulse compressors for petawatt peak power lasers operating at average powers well above 40kW.« less

Characterization of advanced electric propulsion systems

NASA Technical Reports Server (NTRS)

Ray, P. K.

1982-01-01

Characteristics of several advanced electric propulsion systems are evaluated and compared. The propulsion systems studied are mass driver, rail gun, MPD thruster, hydrogen free radical thruster and mercury electron bombardment ion engine. These are characterized by specific impulse, overall efficiency, input power, average thrust, power to average thrust ratio and average thrust to dry weight ratio. Several important physical characteristics such as dry system mass, accelerator length, bore size and current pulse requirement are also evaluated in appropriate cases. Only the ion engine can operate at a specific impulse beyond 2000 sec. Rail gun, MPD thruster and free radical thruster are currently characterized by low efficiencies. Mass drivers have the best performance characteristics in terms of overall efficiency, power to average thrust ratio and average thrust to dry weight ratio. But, they can only operate at low specific impulses due to large power requirements and are extremely long due to limitations of driving current. Mercury ion engines have the next best performance characteristics while operating at higher specific impulses. It is concluded that, overall, ion engines have somewhat better characteristics as compared to the other electric propulsion systems.

Design and experiment of vehicular charger AC/DC system based on predictive control algorithm

NASA Astrophysics Data System (ADS)

He, Guangbi; Quan, Shuhai; Lu, Yuzhang

2018-06-01

For the car charging stage rectifier uncontrollable system, this paper proposes a predictive control algorithm of DC/DC converter based on the prediction model, established by the state space average method and its prediction model, obtained by the optimal mathematical description of mathematical calculation, to analysis prediction algorithm by Simulink simulation. The design of the structure of the car charging, at the request of the rated output power and output voltage adjustable control circuit, the first stage is the three-phase uncontrolled rectifier DC voltage Ud through the filter capacitor, after by using double-phase interleaved buck-boost circuit with wide range output voltage required value, analyzing its working principle and the the parameters for the design and selection of components. The analysis of current ripple shows that the double staggered parallel connection has the advantages of reducing the output current ripple and reducing the loss. The simulation experiment of the whole charging circuit is carried out by software, and the result is in line with the design requirements of the system. Finally combining the soft with hardware circuit to achieve charging of the system according to the requirements, experimental platform proved the feasibility and effectiveness of the proposed predictive control algorithm based on the car charging of the system, which is consistent with the simulation results.

Acute effect of ozone exposure on daily mortality in seven cities of Jiangsu Province, China: No clear evidence for threshold.

PubMed

Chen, Kai; Zhou, Lian; Chen, Xiaodong; Bi, Jun; Kinney, Patrick L

2017-05-01

Few multicity studies have addressed the health effects of ozone in China due to the scarcity of ozone monitoring data. A critical scientific and policy-relevant question is whether a threshold exists in the ozone-mortality relationship. Using a generalized additive model and a univariate random-effects meta-analysis, this research evaluated the relationship between short-term ozone exposure and daily total mortality in seven cities of Jiangsu Province, China during 2013-2014. Spline, subset, and threshold models were applied to further evaluate whether a safe threshold level exists. This study found strong evidence that short-term ozone exposure is significantly associated with premature total mortality. A 10μg/m 3 increase in the average of the current and previous days' maximum 8-h average ozone concentration was associated with a 0.55% (95% posterior interval: 0.34%, 0.76%) increase of total mortality. This finding is robust when considering the confounding effect of PM 2.5 , PM 10 , NO 2 , and SO 2 . No consistent evidence was found for a threshold in the ozone-mortality concentration-response relationship down to concentrations well below the current Chinese Ambient Air Quality Standard (CAAQS) level 2 standard (160μg/m 3 ). Our findings suggest that ozone concentrations below the current CAAQS level 2 standard could still induce increased mortality risks in Jiangsu Province, China. Continuous air pollution control measures could yield important health benefits in Jiangsu Province, China, even in cities that meet the current CAAQS level 2 standard. Copyright © 2017 Elsevier Inc. All rights reserved.

Acute effect of ozone exposure on daily mortality in seven cities of Jiangsu Province, China: No clear evidence for threshold

PubMed Central

Chen, Kai; Zhou, Lian; Chen, Xiaodong; Bi, Jun; Kinney, Patrick L.

2017-01-01

Background Few multicity studies have addressed the health effects of ozone in China due to the scarcity of ozone monitoring data. A critical scientific and policy-relevant question is whether a threshold exists in the ozone-mortality relationship. Methods Using a generalized additive model and a univariate random-effects meta-analysis, this research evaluated the relationship between short-term ozone exposure and daily total mortality in seven cities of Jiangsu Province, China during 2013–2014. Spline, subset, and threshold models were applied to further evaluate whether a safe threshold level exists. Results This study found strong evidence that short-term ozone exposure is significantly associated with premature total mortality. A 10 μg/m3 increase in the average of the current and previous days’ maximum 8-h average ozone concentration was associated with a 0.55% (95% posterior interval: 0.34%, 0.76%) increase of total mortality. This finding is robust when considering the confounding effect of PM2.5, PM10, NO2, and SO2. No consistent evidence was found for a threshold in the ozone-mortality concentration-response relationship down to concentrations well below the current Chinese Ambient Air Quality Standard (CAAQS) level 2 standard (160 μg/m3). Conclusions Our findings suggest that ozone concentrations below the current CAAQS level 2 standard could still induce increased mortality risks in Jiangsu Province, China. Continuous air pollution control measures could yield important health benefits in Jiangsu Province, China, even in cities that meet the current CAAQS level 2 standard. PMID:28231551

Parsing trait and state effects of depression severity on neurocognition: Evidence from a 26-year longitudinal study.

PubMed

Sarapas, Casey; Shankman, Stewart A; Harrow, Martin; Goldberg, Joseph F

2012-11-01

Cognitive dysfunction in mood disorders falls along a continuum, such that more severe current depression is associated with greater cognitive impairment. It is not clear whether this association reflects transient state effects of current symptoms on cognitive performance, or persistent, trait-like differences in cognition that are related to overall disorder severity. We addressed this question in 42 unipolar and 47 bipolar participants drawn from a 26-year longitudinal study of psychopathology, using measures of attention/psychomotor processing speed, cognitive flexibility, verbal fluency, and verbal memory. We assessed (a) the extent to which current symptom severity and past average disorder severity predicted unique variance in cognitive performance; (b) whether cognitive performance covaried with within-individual changes in symptom severity; and (c) the stability of neurocognitive measures over six years. We also tested for differences among unipolar and bipolar groups and published norms. Past average depression severity predicted performance on attention/psychomotor processing speed in both groups, and in cognitive flexibility among unipolar participants, even after controlling for current symptom severity, which did not independently predict cognition. Within-participant state changes in depressive symptoms did not predict change in any cognitive domain. All domains were stable over the course of six years. Both groups showed generalized impairment relative to published norms, and bipolar participants performed more poorly than unipolar participants on attention/psychomotor processing speed. The results suggest a stable relationship between mood disorder severity and cognitive deficits. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Control of Thermo-Acoustics Instabilities: The Multi-Scale Extended Kalman Approach

NASA Technical Reports Server (NTRS)

Le, Dzu K.; DeLaat, John C.; Chang, Clarence T.

2003-01-01

"Multi-Scale Extended Kalman" (MSEK) is a novel model-based control approach recently found to be effective for suppressing combustion instabilities in gas turbines. A control law formulated in this approach for fuel modulation demonstrated steady suppression of a high-frequency combustion instability (less than 500Hz) in a liquid-fuel combustion test rig under engine-realistic conditions. To make-up for severe transport-delays on control effect, the MSEK controller combines a wavelet -like Multi-Scale analysis and an Extended Kalman Observer to predict the thermo-acoustic states of combustion pressure perturbations. The commanded fuel modulation is composed of a damper action based on the predicted states, and a tones suppression action based on the Multi-Scale estimation of thermal excitations and other transient disturbances. The controller performs automatic adjustments of the gain and phase of these actions to minimize the Time-Scale Averaged Variances of the pressures inside the combustion zone and upstream of the injector. The successful demonstration of Active Combustion Control with this MSEK controller completed an important NASA milestone for the current research in advanced combustion technologies.

Numerical investigation of split flows by gravity currents into two-layered stratified water bodies

NASA Astrophysics Data System (ADS)

Cortés, A.; Wells, M. G.; Fringer, O. B.; Arthur, R. S.; Rueda, F. J.

2015-07-01

The behavior of a two-dimensional (2-D) gravity current impinging upon a density step in a two-layered stratified basin is analyzed using a high-resolution Reynolds-Averaged Navier-Stokes model. The gravity current splits at the density step, and the portion of the buoyancy flux becoming an interflow is largely controlled by the vertical distribution of velocity and density within the gravity current and the magnitude of the density step between the two ambient layers. This is in agreement with recent laboratory observations. The strongest changes in the ambient density profiles occur as a result of the impingement of supercritical currents with strong density contrasts, for which a large portion of the gravity current detaches from the bottom and becomes an interflow. We characterize the current partition process in the simulated experiments using the densimetric Froude number of the current (Fr) across the density step (upstream and downstream). When underflows are formed, more supercritical currents are observed downstream of the density step compared to upstream (Fru < Frd), and thus, stronger mixing of the current with the ambient water downstream. However, when split flows and interflows are formed, smaller Fr values are identified after the current crosses the density step (Fru > Frd), which indicates lower mixing between the current and ambient water after the impingement due to the significant stripping of interfacial material at the density step.

VOC from Vehicular Evaporation Emissions: Status and Control Strategy.

PubMed

Liu, Huan; Man, Hanyang; Tschantz, Michael; Wu, Ye; He, Kebin; Hao, Jiming

2015-12-15

Vehicular evaporative emissions is an important source of volatile organic carbon (VOC), however, accurate estimation of emission amounts and scientific evaluation of control strategy for these emissions have been neglected outside of the United States. This study provides four kinds of basic emission factors: diurnal, hot soak, permeation, and refueling. Evaporative emissions from the Euro 4 vehicles (1.6 kg/year/car) are about four times those of U.S. vehicles (0.4 kg/year/car). Closing this emissions gap would have a larger impact than the progression from Euro 3 to Euro 6 tailpipe HC emission controls. Even in the first 24 h of parking, China's current reliance upon the European 24 h diurnal standard results in 508 g/vehicle/year emissions, higher than 32 g/vehicle/year from Tier 2 vehicles. The U.S. driving cycle matches Beijing real-world conditions much better on both typical trip length and average speed than current European driving cycles. At least two requirements should be added to the Chinese emissions standards: an onboard refueling vapor recovery to force the canister to be sized sufficiently large, and a 48-h evaporation test requirement to ensure that adequate purging occurs over a shorter drive sequence.

Controls on the global distribution of contourite drifts: Insights from an eddy-resolving ocean model

NASA Astrophysics Data System (ADS)

Thran, Amanda C.; Dutkiewicz, Adriana; Spence, Paul; Müller, R. Dietmar

2018-05-01

Contourite drifts are anomalously high sediment accumulations that form due to reworking by bottom currents. Due to the lack of a comprehensive contourite database, the link between vigorous bottom water activity and drift occurrence has yet to be demonstrated on a global scale. Using an eddy-resolving ocean model and a new georeferenced database of 267 contourites, we show that the global distribution of modern contourite drifts strongly depends on the configuration of the world's most powerful bottom currents, many of which are associated with global meridional overturning circulation. Bathymetric obstacles frequently modify flow direction and intensity, imposing additional finer-scale control on drift occurrence. Mean bottom current speed over contourite-covered areas is only slightly higher (2.2 cm/s) than the rest of the global ocean (1.1 cm/s), falling below proposed thresholds deemed necessary to re-suspend and redistribute sediments (10-15 cm/s). However, currents fluctuate more frequently and intensely over areas with drifts, highlighting the role of intermittent, high-energy bottom current events in sediment erosion, transport, and subsequent drift accumulation. We identify eddies as a major driver of these bottom current fluctuations, and we find that simulated bottom eddy kinetic energy is over three times higher in contourite-covered areas in comparison to the rest of the ocean. Our work supports previous hypotheses which suggest that contourite deposition predominantly occurs due to repeated acute events as opposed to continuous reworking under average-intensity background flow conditions. This suggests that the contourite record should be interpreted in terms of a bottom current's susceptibility to experiencing periodic, high-speed current events. Our results also highlight the potential role of upper ocean dynamics in contourite sedimentation through its direct influence on deep eddy circulation.

Impaired reading comprehension and mathematical abilities in male adolescents with average or above general intellectual abilities are associated with comorbid and future psychopathology.

PubMed

Weiser, Mark; Reichenberg, Abraham; Rabinowitz, Jonathan; Nahon, Daniella; Kravitz, Efrat; Lubin, Gad; Knobler, Haim Y; Davidson, Michael; Noy, Shlomo

2007-11-01

Research indicates that persons with learning disorders often suffer from psychopathology. We assessed current and future psychopathology in male adolescents with discrete impairments in reading comprehension (IRC) or arithmetic abilities (IAA) but with average or above-average general intellectual abilities. Subjects were a population-based cohort of 174,994 male adolescents screened by the Israeli Draft Board with average or above-average intellectual abilities but with low scores (8.6th and 10th lowest percentile respectively) on reading or arithmetic tests. They were compared with adolescents who scored in the 10th percentile and above on these tests (comparison group). Relative to the comparison group, male adolescents with IRC, IAA, or IRC and IAA (0.69%), had poorer scores on most behavioral assessments and higher prevalence of current psychopathology: 4.2% (comparison group), 8.0% (IRC), 7.0% (IAA), and 9.8% (IRC and IAA). Adolescents with IRC were also at increased risk for later hospitalization for schizophrenia (hazard ratios = 1.8, 95% confidence interval: 1.3-2.6). Male adolescents with average and above-average general intellectual abilities but with IRC or IAA are more likely to have current and future psychopathology. Impairments in intellectual functioning and abnormal behaviors leading to mental illnesses may share common neurobiological substrates. The results support screening male adolescents with learning disorders for psychopathology.

Marine Cloud Brightening: regional applications to the weakening of hurricanes and reduction in coral bleaching

NASA Astrophysics Data System (ADS)

Gadian, A.; Hauser, R.; Kleypas, J. A.; Latham, J.; Parkes, B.; Salter, S.

2013-12-01

This study examines the potential to cool ocean surface waters in regions of hurricane genesis and early development. This would be achieved by seeding, with copious quantities of seawater cloud condensation nuclei (CCN), low-level maritime stratocumulus clouds covering these regions or those at the source of incoming currents. Higher cloud droplet density would increase these clouds' reflectivity to incoming sunlight, and possibly their longevity. This approach is a more localized application of the Marine Cloud Brightening (MCB) geoengineering technique promoting global cooling. By utilizing a climate ocean/atmosphere coupled model, HadGEM1, and by judicious seeding of maritime stratocumulus clouds, we demonstrate that we may be able to significantly reduce sea surface temperatures (SSTs) in hurricane development regions. Thus artificial seeding may reduce hurricane intensity; but how well the magnitude of this effect is yet to be determined. Increases in coral bleaching events over the last few decades have been largely caused by rising SSTs, and continued warming is expected to cause even greater increases through this century. Using thr same Global Climate Model to examine the potential of MCB to cool oceanic surface waters in three coral reef provinces. Our simulations indicate that under doubled CO2 conditions, the substantial increases in coral bleaching conditions from current values in three reef regions (Caribbean, French Polynesia, and the Great Barrier Reef) were eliminated when MCB was applied, which reduced the SSTs at these sites roughly to their original values. In this study we also illustrate how even regional application of MCB can affect the planetary meridional heat flux and the reduction in poleward heat transfer. (a) Change in annual average sea surface temperature, Celsius, between the 2xCO2 and CONTROL simulations. (b) Change in annual average sea surface temperature, Celsius, between the CONTROL and 2xCO2+MCB simulations. The dashed black boxes in both panels represent the three coral reef regions. In the Southern north Atlantic, the warmer SSTs in (a) is reduced to the current "control" temperatures, weakening hurricane formation.

Opportunities for Improved Chagas Disease Vector Control Based on Knowledge, Attitudes and Practices of Communities in the Yucatan Peninsula, Mexico

PubMed Central

Rosecrans, Kathryn; Cruz-Martin, Gabriela; King, Ashley; Dumonteil, Eric

2014-01-01

Background Chagas disease is a vector-borne parasitic disease of major public health importance. Current prevention efforts are based on triatomine vector control to reduce transmission to humans. Success of vector control interventions depends on their acceptability and value to affected communities. We aimed to identify opportunities for and barriers to improved vector control strategies in the Yucatan peninsula, Mexico. Methodology/principal findings We employed a sequence of qualitative and quantitative research methods to investigate knowledge, attitudes and practices surrounding Chagas disease, triatomines and vector control in three rural communities. Our combined data show that community members are well aware of triatomines and are knowledgeable about their habits. However, most have a limited understanding of the transmission dynamics and clinical manifestations of Chagas disease. While triatomine control is not a priority for community members, they frequently use domestic insecticide products including insecticide spray, mosquito coils and plug-in repellents. Families spend about $32 US per year on these products. Alternative methods such as yard cleaning and window screens are perceived as desirable and potentially more effective. Screens are nonetheless described as unaffordable, in spite of a cost comparable to the average annual spending on insecticide products. Conclusion/Significance Further education campaigns and possibly financing schemes may lead families to redirect their current vector control spending from insecticide products to window screens. Also, synergism with mosquito control efforts should be further explored to motivate community involvement and ensure sustainability of Chagas disease vector control. PMID:24676038

Investigating the effect of sputtering conditions on the physical properties of aluminum thin film and the resulting alumina template

NASA Astrophysics Data System (ADS)

Taheriniya, Shabnam; Parhizgar, Sara Sadat; Sari, Amir Hossein

2018-06-01

To study the alumina template pore size distribution as a function of Al thin film grain size distribution, porous alumina templates were prepared by anodizing sputtered aluminum thin films. To control the grain size the aluminum samples were sputtered with the rate of 0.5, 1 and 2 Å/s and the substrate temperature was either 25, 75 or 125 °C. All samples were anodized for 120 s in 1 M sulfuric acid solution kept at 1 °C while a 15 V potential was being applied. The standard deviation value for samples deposited at room temperature but with different rates is roughly 2 nm in both thin film and porous template form but it rises to approximately 4 nm with substrate temperature. Samples with the average grain size of 13, 14, 18.5 and 21 nm respectively produce alumina templates with an average pore size of 8.5, 10, 15 and 16 nm in that order which shows the average grain size limits the average pore diameter in the resulting template. Lateral correlation length and grain boundary effect are other factors that affect the pore formation process and pore size distribution by limiting the initial current density.

Variation of froude number with discharge for large-gradient steams

USGS Publications Warehouse

Wahl, Kenneth L.; ,

1993-01-01

Under chemical-control conditions, the Froude number (f) for a cross-section can be approximated as a function of the ratio R2/ 3/d 1/2 , where R is the hydraulic radius and d is the average depth. For cross sections where the ratio increases with increasing depth, F can also increase with depth Current-meter measurement data for 433 streamflow gaging stations in Colorado were reviewed, and 62 stations were identified at which F increases with depth of flow. Data for four streamflow gaging stations are presented. In some cases, F approaches 1 as the discharge approaches the magnitude of the median annual peak discharge. The data also indicate that few actual current meter measurement have been made at the large discharges where velocities can be supercritical.

Applying mathematical modeling to create job rotation schedules for minimizing occupational noise exposure.

PubMed

Tharmmaphornphilas, Wipawee; Green, Benjamin; Carnahan, Brian J; Norman, Bryan A

2003-01-01

This research developed worker schedules by using administrative controls and a computer programming model to reduce the likelihood of worker hearing loss. By rotating the workers through different jobs during the day it was possible to reduce their exposure to hazardous noise levels. Computer simulations were made based on data collected in a real setting. Worker schedules currently used at the site are compared with proposed worker schedules from the computer simulations. For the worker assignment plans found by the computer model, the authors calculate a significant decrease in time-weighted average (TWA) sound level exposure. The maximum daily dose that any worker is exposed to is reduced by 58.8%, and the maximum TWA value for the workers is reduced by 3.8 dB from the current schedule.

Using chromatogram averaging to improve quantitation of minor impurities.

PubMed

Zawatzky, Kerstin; Lin, Mingxiang; Schafer, Wes; Mao, Bing; Trapp, Oliver; Welch, Christopher J

2016-09-23

Averaging of chromatograms can lead to enhancement of signal to noise ratio (S/N) in proportion to the square root of the number of measurements. Although the general principle has been known for decades, chromatogram averaging is almost never used in current pharmaceutical research. In this study we explore the utility of this approach, showing it to be a simple and easily accessible method for boosting sensitivity for quantification of minor components and trace impurities, where current techniques deliver insufficient S/N. Copyright © 2016 Elsevier B.V. All rights reserved.

Linear association between household income and metabolic control in children with insulin-dependent diabetes mellitus despite free access to health care.

PubMed

Deladoëy, Johnny; Henderson, Mélanie; Geoffroy, Louis

2013-05-01

In health care systems with a user fee, the impact of socioeconomic factors on pediatric insulin-dependent diabetes mellitus (IDDM) control could be due to the cost of accessing care. There is a linear association between household income and the average glycosylated hemoglobin (HbA1c) of children and adolescents with IDDM despite free access to health care. We used a linear regression model to examine the association between normalized average HbA1c of 1766 diabetic children (diagnosed at our institution from 1980 to 2011 before 17 years of age) and the median household income of their neighborhoods (obtained from Statistics Canada, 2006 Census data). We found a negative linear association (P < .001; r = -0.2) between the level of income and metabolic control assessed by HbA1c after controlling for sex, age at diagnosis, duration of diabetes, ethnicity, geographical factors, frequency of visits, current age (as a proxy for change in practice over time), and change of measurement methods of HbA1c across time. For every increase of $15,000 in annual income, HbA1c decreased by 0.1%. We report a linear association of household income with metabolic control of IDDM in childhood. Given that Canada has a system of free universal access to health care, confounding by access to care is unlikely. Considering the impact of poorly controlled IDDM in childhood on the development of long-term complications, our findings suggest that the higher complication rate found in adults of low socioeconomic status might originate from the poor control that they experienced in childhood. Support for the care of IDDM children from low-income neighborhoods should be increased.

Stratospheric aerosol geoengineering

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

Robock, Alan

2015-03-30

The Geoengineering Model Intercomparison Project, conducting climate model experiments with standard stratospheric aerosol injection scenarios, has found that insolation reduction could keep the global average temperature constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform; the tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without geoengineering. If geoengineering were halted all at once, there would be rapid temperature and precipitation increases at 5–10 times the rates frommore » gradual global warming. The prospect of geoengineering working may reduce the current drive toward reducing greenhouse gas emissions, and there are concerns about commercial or military control. Because geoengineering cannot safely address climate change, global efforts to reduce greenhouse gas emissions and to adapt are crucial to address anthropogenic global warming.« less

2 MeV linear accelerator for industrial applications

NASA Astrophysics Data System (ADS)

Smith, Richard R.; Farrell, Sherman R.

1997-02-01

RPC Industries has developed a high average power scanned electron beam linac system for medium energy industrial processing, such as in-line sterilization. The parameters are: electron energy 2 MeV; average beam current 5.0 mA; and scanned width 0.5 meters. The control system features data logging and a Man-Machine Interface system. The accelerator is vertically mounted, the system height above the floor is 3.4 m, and the footprint is 0.9×1.2 meter2. The typical processing cell inside dimensions are 3.0 m by 3.5 m by 4.2 m high with concrete side walls 0.5 m thick above ground level. The equal exit depth dose is 0.73 gm cm-2. Additional topics that will be reported are: throughput, measurements of dose vs depth, dose uniformity across the web, and beam power by calorimeter and magnetic deflection of the beam.

Scanning the pressure-induced distortion of fingerprints.

PubMed

Mil'shtein, S; Doshi, U

2004-01-01

Fingerprint recognition technology is an important part of criminal investigations it is the basis of some security systems and an important tool of government operations such as the Immigration and Naturalization Services, registration procedures in the Armed Forces, and so forth. After the tragic events of September 11, 2001, the importance of reliable fingerprint recognition technology became even more obvious. In the current study, pressure-induced changes of distances between ridges of a fingerprint were measured. Using calibrated silicon pressure sensors we scanned the distribution of pressure across a finger pixel by pixel, and also generated maps of an average pressure distribution during fingerprinting. Emulating the fingerprinting procedure employed with widely used optical scanners, we found that on average the distance between ridges decreases by about 20% when a finger is positioned on a scanner. Controlled loading of a finger demonstrated that it is impossible to reproduce the same distribution of pressure across a given finger during repeated fingerprinting procedures.

Denudation rates derived from spatially-averaged cosmogenic nuclide analysis in Nelson catchments, South Island, New Zealand

NASA Astrophysics Data System (ADS)

Burdis, A.; Norton, K. P.; Ditchburn, B.; Zondervan, A.

2013-12-01

New Zealand's tectonically and climatically dynamic environment generates erosion rates that outstrip global averages by up to ten times in some locations. In order to assess recent changes in erosion rate, and also to predict future erosion dynamics, it is important to quantify long-term, background erosion. Current research on erosion in New Zealand predominantly covers short-term (100 yrs) erosion dynamics and Myr dynamics from thermochronological proxy data. Without medium-term denudation data for New Zealand, it is uncertain which variables (climate, anthropogenic disturbance of the landscape, tectonic uplift, lithological, or geomorphic characteristics) exert the dominant control on denudation in New Zealand. Spatially-averaged cosmogenic nuclide analysis can effectively offer this information by providing averaged rates of denudation on millennial timescales without the biases and limitations of short-term erosion methods. Basin-averaged denudation rates were obtained in the Nelson region, New Zealand, from analysis of concentrations of meteoric 10Be in clay and in-situ produced 10Be in quartz. The measured denudation rates integrate over ~8000 yrs (meteoric) and ~3000 yrs (in-situ). Not only do the 10Be records produce erosion rates that are remarkably consistent with each other, but they are also independent of topographic metrics. Denudation rates range from ~116 - 306 t km-2 yr-1, with the exception of one basin which is eroding at 789 t km-2 yr-1(derived from meteoric 10Be) and 644 t km-2 yr-1(derived from in-situ 10Be). The homogeneity of rates and absence of a significant correlation with geomorphic or lithological characteristics suggest another factor is exerting the dominant control on landscape denudation in the Nelson region. Storm variability is a likely driver of erosion in this setting. The background rates are higher than current short term rates (~50 - 200 t km-2 yr-1) due to the significant erosion caused by high magnitude, low frequency events. This is highlighted by sediment yields reaching ~2535 t km-2 yr-1 following storm events in the Nelson region (Basher et al., 2011). At least on the northern South Island of New Zealand, extreme climatic events appear to be the main driver of elevated denudation rates. Basher, L., Hicks, D., Clapp, B., & Hewitt, T. (2011). Sediment Yield Response to Large Storm Events and Forest Harvesting, Motueka River, New Zealand. New Zealand Journal ofMarine and Freshwater Research, Vol. 45, No. 3 , 333-356.

The effect of age-at-testing on verbal memory among children following severe traumatic brain injury.

PubMed

Silberg, Tamar; Ahonniska-Assa, Jaana; Levav, Miriam; Eliyahu, Roni; Peleg-Pilowsky, Tamar; Brezner, Amichai; Vakil, Eli

2016-01-01

Memory deficits are a common sequelae following childhood traumatic brain injury (TBI), which often have serious implications on age-related academic skills. The current study examined verbal memory performance using the Rey Auditory Verbal Learning Test (RAVLT) in a pediatric TBI sample. Verbal memory abilities as well as the effect of age at-testing on performance were examined. A sample of 67 children following severe TBI (age average = 12.3 ± 2.74) and 67 matched controls were evaluated using the RAVLT. Age effect at assessment was examined using two age groups: above and below 12 years of age during evaluation. Differences between groups were examined via the 9 RAVLT learning trials and the 7 composite scores conducted out of them. Children following TBI recalled significantly less words than controls on all RAVLT trials and had significantly lower scores on all composite scores. However, all of these scores fell within the low average range. Further analysis revealed significantly lower than average performance among the older children (above 12 years), while scores of the younger children following TBI fell within average limits. To conclude, verbal memory deficits among children following severe TBI demonstrate an age-at-testing effect with more prominent problems occurring above 12 years at the time of evaluation. Yet, age-appropriate performance among children below 12 years of age may not accurately describe memory abilities at younger ages following TBI. It is therefore recommended that clinicians address child's age at testing and avoid using a single test as an indicator of verbal memory functioning post TBI.

A joint model of persistent human papillomavirus infection and cervical cancer risk: Implications for cervical cancer screening

PubMed Central

Katki, Hormuzd A.; Cheung, Li C.; Fetterman, Barbara; Castle, Philip E.; Sundaram, Rajeshwari

2014-01-01

Summary New cervical cancer screening guidelines in the US and many European countries recommend that women get tested for human papillomavirus (HPV). To inform decisions about screening intervals, we calculate the increase in precancer/cancer risk per year of continued HPV infection. However, both time to onset of precancer/cancer and time to HPV clearance are interval-censored, and onset of precancer/cancer strongly informatively censors HPV clearance. We analyze this bivariate informatively interval-censored data by developing a novel joint model for time to clearance of HPV and time to precancer/cancer using shared random-effects, where the estimated mean duration of each woman’s HPV infection is a covariate in the submodel for time to precancer/cancer. The model was fit to data on 9,553 HPV-positive/Pap-negative women undergoing cervical cancer screening at Kaiser Permanente Northern California, data that were pivotal to the development of US screening guidelines. We compare the implications for screening intervals of this joint model to those from population-average marginal models of precancer/cancer risk. In particular, after 2 years the marginal population-average precancer/cancer risk was 5%, suggesting a 2-year interval to control population-average risk at 5%. In contrast, the joint model reveals that almost all women exceeding 5% individual risk in 2 years also exceeded 5% in 1 year, suggesting that a 1-year interval is better to control individual risk at 5%. The example suggests that sophisticated risk models capable of predicting individual risk may have different implications than population-average risk models that are currently used for informing medical guideline development. PMID:26556961

A joint model of persistent human papillomavirus infection and cervical cancer risk: Implications for cervical cancer screening.

PubMed

Katki, Hormuzd A; Cheung, Li C; Fetterman, Barbara; Castle, Philip E; Sundaram, Rajeshwari

2015-10-01

New cervical cancer screening guidelines in the US and many European countries recommend that women get tested for human papillomavirus (HPV). To inform decisions about screening intervals, we calculate the increase in precancer/cancer risk per year of continued HPV infection. However, both time to onset of precancer/cancer and time to HPV clearance are interval-censored, and onset of precancer/cancer strongly informatively censors HPV clearance. We analyze this bivariate informatively interval-censored data by developing a novel joint model for time to clearance of HPV and time to precancer/cancer using shared random-effects, where the estimated mean duration of each woman's HPV infection is a covariate in the submodel for time to precancer/cancer. The model was fit to data on 9,553 HPV-positive/Pap-negative women undergoing cervical cancer screening at Kaiser Permanente Northern California, data that were pivotal to the development of US screening guidelines. We compare the implications for screening intervals of this joint model to those from population-average marginal models of precancer/cancer risk. In particular, after 2 years the marginal population-average precancer/cancer risk was 5%, suggesting a 2-year interval to control population-average risk at 5%. In contrast, the joint model reveals that almost all women exceeding 5% individual risk in 2 years also exceeded 5% in 1 year, suggesting that a 1-year interval is better to control individual risk at 5%. The example suggests that sophisticated risk models capable of predicting individual risk may have different implications than population-average risk models that are currently used for informing medical guideline development.

Climate and ET: Does Plant Water Requirements Increase during Droughts?

NASA Astrophysics Data System (ADS)

Fipps, G.

2015-12-01

Municipalities, engineering consultants and State agencies use reference evapotranspiration (ETo) data (directly and indirectly) for long-term water planning, for designing hydraulic structures, and for establishing regulatory guidance and conservation programs intended to reduce water waste. The use ETo data for agricultural and landscape irrigation scheduling is becoming more common in Texas as ETo-based controllers and automation technologies become more affordable. Until recently, most ETo data has been available as monthly values averaged over many years. Today, automated weather stations and irrigation controllers equipped with specialized instrumentation allow for real-time ETo measurements. With the expected rise in global warming and increased frequency of extreme climate variability in the coming decades, conservation and efficient use of water resources is essential and must make use of the most accurate and representative data available. 2011 marked the driest year on record in the State of Texas. Compounding the lack of rainfall was record heat during the Summer of 2011. An analysis of real time ETo (reference evapotranspiration) data in Texas found that ET was 30 to 50% higher than historic averages during the 2011 Summer. The implications are quite serious, as most current water planning and drought contingency plans do not take into consideration increases in ET during such periods, and irrigation planning and capacity sizing are based on historic averages of consumptive use. This paper examines the relationship between ET and climate during this extreme climatic event. While the solar radiation was near normal levels, temperature and wind was much higher and dew points much lower than norms. The variability and statistical difference between average monthly ETo data and daily, monthly and seasonal ETo measurements (from 2006 to 2014) for selected weather stations of the Texas ET Network. This study will also examine the suitability of using average ETo rates for use in regional water planning and in irrigation scheduling.

Scented guide ropes as a method to enhance brown treesnake (Boiga irregularis) trap capture success on Guam

USGS Publications Warehouse

Mason, L.C.; Savidge, J.A.; Rodda, G.H.; Yackel Adams, A.A.

2011-01-01

Current methods for controlling the invasive Brown Treesnake (Boiga irregularis) on Guam include a modified minnow trap with a live mouse lure. We investigated the effects on capture success of augmenting these traps with scented guide ropes leading to trap entrances. Initial screening of scent preferences was based on time spent in scented and unscented arms of a Y-maze. Preferences of large and small snakes were scored for six different prey scents (live and carrion gecko, skink, and mouse). Large snakes spent more time in the maze arm scented with live gecko and carrion gecko, whereas small snakes spent more time in the arm scented with carrion mouse and carrion gecko. After the laboratory study, a pilot trapping session was conducted in the field using three treatments (live mouse-scented ropes, carrion gecko-scented ropes, and carrion mouse-scented ropes) and two controls (traps with unscented guide ropes and those with no ropes attached). Contrary to laboratory results, live mouse-scented ropes were most effective. We conducted a second trapping session using live mouse-scented ropes as well as the two controls used in the pilot study. For snakes of below-average to average condition, the number of captures for traps with live mouse-scented ropes was higher than for traps with no ropes. However, for snakes of above-average condition, there were no differences in capture rates between trap treatments. Overall, treatment effects were weaker than latent individual heterogeneity and the influence of snake body size, with large snakes trapped more readily. ?? 2011 Society for the Study of Amphibians and Reptiles.

Design and development of a low cost, high current density power supply for streamer free atmospheric pressure DBD plasma generation in air.

PubMed

Jain, Vishal; Visani, Anand; Srinivasan, R; Agarwal, Vivek

2018-03-01

This paper presents a new power supply architecture for generating a uniform dielectric barrier discharge (DBD) plasma in air medium at atmospheric pressure. It is quite a challenge to generate atmospheric pressure uniform glow discharge plasma, especially in air. This is because air plasma needs very high voltage for initiation of discharge. If the high voltage is used along with high current density, it leads to the formation of streamers, which is undesirable for most applications like textile treatment, etc. Researchers have tried to generate high-density plasma using a RF source, nanosecond pulsed DC source, and medium frequency AC source. However, these solutions suffer from low current discharge and low efficiency due to the addition of an external resistor to control the discharge current. Moreover, they are relatively costly and bulky. This paper presents a new power supply configuration which is very compact and generates high average density (∼0.28 W/cm 2 ) uniform glow DBD plasma in air at atmospheric pressure. The efficiency is also higher as no external resistor is required to control the discharge current. An inherent feature of this topology is that it can drive higher current oscillations (∼50 A peak and 2-3 MHz frequency) into the plasma that damp out due to the plasma dissipation only. A newly proposed model has been used with experimental validation in this paper. Simulations and experimental validation of the proposed topology are included. Also, the application of the generated plasma for polymer film treatment is demonstrated.

Design and development of a low cost, high current density power supply for streamer free atmospheric pressure DBD plasma generation in air

NASA Astrophysics Data System (ADS)

Jain, Vishal; Visani, Anand; Srinivasan, R.; Agarwal, Vivek

2018-03-01

This paper presents a new power supply architecture for generating a uniform dielectric barrier discharge (DBD) plasma in air medium at atmospheric pressure. It is quite a challenge to generate atmospheric pressure uniform glow discharge plasma, especially in air. This is because air plasma needs very high voltage for initiation of discharge. If the high voltage is used along with high current density, it leads to the formation of streamers, which is undesirable for most applications like textile treatment, etc. Researchers have tried to generate high-density plasma using a RF source, nanosecond pulsed DC source, and medium frequency AC source. However, these solutions suffer from low current discharge and low efficiency due to the addition of an external resistor to control the discharge current. Moreover, they are relatively costly and bulky. This paper presents a new power supply configuration which is very compact and generates high average density (˜0.28 W/cm2) uniform glow DBD plasma in air at atmospheric pressure. The efficiency is also higher as no external resistor is required to control the discharge current. An inherent feature of this topology is that it can drive higher current oscillations (˜50 A peak and 2-3 MHz frequency) into the plasma that damp out due to the plasma dissipation only. A newly proposed model has been used with experimental validation in this paper. Simulations and experimental validation of the proposed topology are included. Also, the application of the generated plasma for polymer film treatment is demonstrated.

Parkinson's disease management strategies.

PubMed

Rajput, Alex; Rajput, Ali H

2006-01-01

Parkinson's disease (PD) treatment strategies should consider each patient individually. Drug therapy is the mainstay of treatment. An average 62-year-old male first diagnosed with PD will likely live for 20 years and treatment should be geared for long-term control of symptoms and quality of life. Of the currently available drugs, none are neurotoxic to the human substantia nigra and none are neuroprotective. As PD is a progressive disorder, all drugs have adverse effects and reduced efficacy with time. PD patients need regular follow-ups to make necessary medication adjustments. There is no perfect treatment. The authors have discussed their treatment methods and the reasoning behind it. Depending on the patient's age, the predominant symptoms and quality of life, treatment is individualized. In an average patient the least potent drugs, such as anticholinergics or amantadine, are administered first adding a dopamine agonist later on. Levodopa (LD) remains the most useful drug for PD and is reserved for later stages of disease. The objective is to keep the patient at Hoehn and Yahr Stage 2.0 or lower level of disability (bilateral findings with preserved postural reflexes) during off-stage and to avoid adverse effects. There is no long-term difference between standard preparations and control release formulations of LD/carbidopa or LD/benserazide. In older subjects, the first choice is LD. In patients who cannot be managed medically, surgical treatment is an option in selected patients (nondemented, <70 years old, previous good LD response). The surgical treatment of choice is currently subthalamic nucleus deep-brain stimulation. Physiotherapy, occupational therapy and speech therapy are valuable in advanced PD cases.

The Design and Development of the SMEX-Lite Power System

NASA Technical Reports Server (NTRS)

Rakow, Glenn P.; Schnurr, Richard G., Jr.; Solly, Michael A.

1998-01-01

This paper describes the design and development of a 250W orbit average electrical power system electronic Power Node and software for use in Low Earth Orbit missions. The mass of the Power Node is 3.6 Kg (8 lb.). The dimensions of the Power Node are 30cm x 26cm x 7.9cm (11 in. x 10.25 in x 3.1 in.) The design was realized using software, Field Programmable Gate Array (FPGA) digital logic and surface mount technology. The design is generic enough to reduce the non-recurring engineering for different mission configurations. The Power Node charges one to five, low cost, 22-cell 4 AH D-cell battery packs independently. The battery charging algorithms are executed in the power software to reduce the mass and size of the power electronic. The Power Node implements a peak-power tracking algorithm using an innovative hardware/software approach. The power software task is hosted on the spacecraft processor. The power software task generates a MIL-STD-1553 command packet to update the Power Node control settings. The settings for the battery voltage and current limits, as well as minimum solar array voltage used to implement peak power tracking are contained in this packet. Several advanced topologies are used in the Power Node. These include synchronous rectification in the bus regulators, average current control in the battery chargers and quasi-resonant converters for the Field Effect Transistor (FET) transistor drive electronics. Lastly, the main bus regulator uses a feed-forward topology with the PWM implemented in an FPGA.

How to Invest in Getting Cost-effective Technologies into Practice? A Framework for Value of Implementation Analysis Applied to Novel Oral Anticoagulants.

PubMed

Faria, Rita; Walker, Simon; Whyte, Sophie; Dixon, Simon; Palmer, Stephen; Sculpher, Mark

2017-02-01

Cost-effective interventions are often implemented slowly and suboptimally in clinical practice. In such situations, a range of implementation activities may be considered to increase uptake. A framework is proposed to use cost-effectiveness analysis to inform decisions on how best to invest in implementation activities. This framework addresses 2 key issues: 1) how to account for changes in utilization in the future in the absence of implementation activities; and 2) how to prioritize implementation efforts between subgroups. A case study demonstrates the framework's application: novel oral anticoagulants (NOACs) for the prevention of stroke in the National Health Service in England and Wales. The results suggest that there is value in additional implementation activities to improve uptake of NOACs, particularly in targeting patients with average or poor warfarin control. At a cost-effectiveness threshold of £20,000 per quality-adjusted life-year (QALY) gained, additional investment in an educational activity that increases the utilization of NOACs by 5% in all patients currently taking warfarin generates an additional 254 QALYs, compared with 973 QALYs in the subgroup with average to poor warfarin control. However, greater value could be achieved with higher uptake of anticoagulation more generally: switching 5% of patients who are potentially eligible for anticoagulation but are currently receiving no treatment or are using aspirin would generate an additional 4990 QALYs. This work can help health services make decisions on investment at different points of the care pathway or across disease areas in a manner consistent with the value assessment of new interventions.

Update of Ireland's national average indoor radon concentration - Application of a new survey protocol.

PubMed

Dowdall, A; Murphy, P; Pollard, D; Fenton, D

2017-04-01

In 2002, a National Radon Survey (NRS) in Ireland established that the geographically weighted national average indoor radon concentration was 89 Bq m -3 . Since then a number of developments have taken place which are likely to have impacted on the national average radon level. Key among these was the introduction of amending Building Regulations in 1998 requiring radon preventive measures in new buildings in High Radon Areas (HRAs). In 2014, the Irish Government adopted the National Radon Control Strategy (NRCS) for Ireland. A knowledge gap identified in the NRCS was to update the national average for Ireland given the developments since 2002. The updated national average would also be used as a baseline metric to assess the effectiveness of the NRCS over time. A new national survey protocol was required that would measure radon in a sample of homes representative of radon risk and geographical location. The design of the survey protocol took into account that it is not feasible to repeat the 11,319 measurements carried out for the 2002 NRS due to time and resource constraints. However, the existence of that comprehensive survey allowed for a new protocol to be developed, involving measurements carried out in unbiased randomly selected volunteer homes. This paper sets out the development and application of that survey protocol. The results of the 2015 survey showed that the current national average indoor radon concentration for homes in Ireland is 77 Bq m -3 , a decrease from the 89 Bq m -3 reported in the 2002 NRS. Analysis of the results by build date demonstrate that the introduction of the amending Building Regulations in 1998 have led to a reduction in the average indoor radon level in Ireland. Copyright © 2016 Elsevier Ltd. All rights reserved.

Power electronics for low power arcjets

NASA Technical Reports Server (NTRS)

Hamley, John A.; Hill, Gerald M.

1991-01-01

In anticipation of the needs of future light-weight, low-power spacecraft, arcjet power electronics in the 100 to 400 W operating range were developed. Limited spacecraft power and thermal control capacity of these small spacecraft emphasized the need for high efficiency. Power topologies similar to those in the higher 2 kW and 5 to 30 kW power range were implemented, including a four transistor bridge switching circuit, current mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter. Electromagnetic compatibility requirements were not considered in this work, and control power for the converter was derived from AC mains. Addition of input filters and control power converters would result in an efficiency of on the order of 90 percent for a flight unit. Due to the developmental nature of arcjet systems at this power level, the exact nature of the thruster/power processor interface was not quantified. Output regulation and current ripple requirements of 1 and 20 percent respectively, as well as starting techniques, were derived from the characteristics of the 2 kW system but an open circuit voltage in excess of 175 V was specified. Arcjet integration tests were performed, resulting in successful starts and stable arcjet operation at power levels as low as 240 W with simulated hydrazine propellants.

Endothelial dysfunction and history of recurrent depression in postmenopausal women with Type 2 diabetes: a case-control study.

PubMed

Wagner, Julie; Tennen, Howard; Mansoor, George; Abbott, Gina

2009-01-01

This study of postmenopausal women with Type 2 diabetes mellitus (T2DM) investigated (1) history of depression as a predictor of endothelium-dependent flow-mediated dilation (FMD); (2) the relative associations of single and recurrent depressive disorders with FMD; and (3) cortisol as a potential mechanism. Participants were nonsmoking, naturally postmenopausal women with T2DM with no known vascular disease. All were free of current mood disorder. On average, the 44 participants were 63 years of age, White, diabetic for 6 years, and were in adequate glycemic control. Thirty-eight percent were never depressed, 19% had experienced one disorder, and 43% had experienced recurrent disorders. History of depression was assessed with Structured Clinical Interview for Diagnostic and Statistical Manual-IV. Current depressive symptoms were measured with Center for Epidemiological Studies Depression (CESD) scale. FMD was assessed by standard procedures and calculated as percent change in brachial artery diameter from baseline. Women with history of recurrent depression showed vasoconstriction (mean=-1%), which was significantly different from women with history of single depression (mean=+6) and never depressed women (mean=+5) (P<.05), both of whom showed similar levels of vasodilation. In logistic regression controlling for hypertension, duration of diabetes, and glycemic control, history of recurrent depressive disorders predicted greater likelihood of vasoconstriction (P<.05, odds ratio=4.23) but history of single depressive disorder did not. Controlling for current depressive symptoms did not account for effects of past recurrent depressive disorders. Cortisol was not related to FMD. In postmenopausal women with T2DM, recurrent depressive disorders, even in full remission, are associated with endothelial dysfunction. Potential mechanisms of the relationship between depression and endothelial dysfunction other than cortisol warrant investigation.

The current status of syphilis prevention and control in Jiangsu province, China: A cross-sectional study

PubMed Central

Chen, Yuan-Fang; Ding, Jian-Ping; Yan, Hong-Jing; Lu, Jing; Ding, Ping; Chen, Guo-Hong; Li, Jian-Jun; Huan, Xi-Ping; Yang, Hai-Tao; Tang, Wei-Ming; Fu, Geng-Feng

2017-01-01

Objective To analyze the midterm evaluation data from the National Syphilis Prevention and Control Plan (2010–2020) and evaluate the current status of syphilis prevention and control in Jiangsu province, China. Methods We collected data via (1) field surveys conducted in 2015 and (2) data recorded in existing syphilis surveillance systems. We conducted descriptive statistical analysis to evaluate the current landscape of syphilis control initiatives and their potential effect in syphilis control. Results The incidence of all cases of syphilis decreased from 2010 (32.3 per 100,000) to 2015 (30.1 per 100,000), with an annual growth of -1.17% (x2trend = -7.52, P<0.001) in Jiangsu province. The incidence of primary and secondary syphilis and congenital syphilis both decreased significantly from 2010 to 2015. The average awareness rate of syphilis knowledge among professional personnel was 95.4% (3781/3963). Rural residents had the lowest awareness rate (83.5%, 1875/2245) and commercial sex workers had the highest awareness rate (92.1%, 7804/8474) in 2015. Only 47.8% (33908/70894) of patients received provider-initiated syphilis counseling and testing (PISTC) services in sexually transmitted disease (STD) clinics, but 94.5% (87927/93020) of all syphilis patients received free testing for syphilis. Overall, 97.2% (9378/9648) of syphilis reported cases of syphilis at medical institutions were confirmed to be accurate, and 92.2% (5850/6345) of patients diagnosed with syphilis at medical institutions received treatment with penicillin. Conclusion The syphilis incidence rate in Jiangsu has decreased in recent years, but remains at a high level. It is essential to promote PISTC services to improve knowledge of syphilis and rates of testing and treatment in Jiangsu province. PMID:28837587

The current status of syphilis prevention and control in Jiangsu province, China: A cross-sectional study.

PubMed

Chen, Yuan-Fang; Ding, Jian-Ping; Yan, Hong-Jing; Lu, Jing; Ding, Ping; Chen, Guo-Hong; Li, Jian-Jun; Huan, Xi-Ping; Yang, Hai-Tao; Tang, Wei-Ming; Fu, Geng-Feng

2017-01-01

To analyze the midterm evaluation data from the National Syphilis Prevention and Control Plan (2010-2020) and evaluate the current status of syphilis prevention and control in Jiangsu province, China. We collected data via (1) field surveys conducted in 2015 and (2) data recorded in existing syphilis surveillance systems. We conducted descriptive statistical analysis to evaluate the current landscape of syphilis control initiatives and their potential effect in syphilis control. The incidence of all cases of syphilis decreased from 2010 (32.3 per 100,000) to 2015 (30.1 per 100,000), with an annual growth of -1.17% (x2trend = -7.52, P<0.001) in Jiangsu province. The incidence of primary and secondary syphilis and congenital syphilis both decreased significantly from 2010 to 2015. The average awareness rate of syphilis knowledge among professional personnel was 95.4% (3781/3963). Rural residents had the lowest awareness rate (83.5%, 1875/2245) and commercial sex workers had the highest awareness rate (92.1%, 7804/8474) in 2015. Only 47.8% (33908/70894) of patients received provider-initiated syphilis counseling and testing (PISTC) services in sexually transmitted disease (STD) clinics, but 94.5% (87927/93020) of all syphilis patients received free testing for syphilis. Overall, 97.2% (9378/9648) of syphilis reported cases of syphilis at medical institutions were confirmed to be accurate, and 92.2% (5850/6345) of patients diagnosed with syphilis at medical institutions received treatment with penicillin. The syphilis incidence rate in Jiangsu has decreased in recent years, but remains at a high level. It is essential to promote PISTC services to improve knowledge of syphilis and rates of testing and treatment in Jiangsu province.

Use of acoustic backscatter and vertical velocity to estimate concentration and dynamics of suspended solids in Upper Klamath Lake, south-central Oregon: Implications for Aphanizomenon flos-aquae

USGS Publications Warehouse

Wood, Tamara M.; Gartner, Jeffrey W.

2010-01-01

Vertical velocity and acoustic backscatter measurements by acoustic Doppler current profilers were used to determine seasonal, subseasonal (days to weeks), and diel variation in suspended solids in a freshwater lake where massive cyanobacterial blooms occur annually. During the growing season, the suspended material in the lake is dominated by the buoyancy-regulating cyanobacteria, Aphanizomenon flos-aquae. Measured variables (water velocity, relative backscatter [RB], wind speed, and air and water temperatures) were averaged over the deployment season at each sample time of day to determine average diel cycles. Phase shifts between diel cycles in RB and diel cycles in wind speed, vertical water temperature differences (delta T(degree)), and horizontal current speeds were found by determining the lead or lag that maximized the linear correlation between the respective diel cycles. Diel cycles in RB were more in phase with delta T(degree) cycles, and, to a lesser extent, wind cycles, than to water current cycles but were out of phase with the cycle that would be expected if the vertical movement of buoyant cyanobacteria colonies was controlled primarily by light. Clear evidence of a diel cycle in vertical velocity was found only at the two deepest sites in the lake. Cycles of vertical velocity, where present, were out of phase with expected vertical motion of cyanobacterial colonies based on the theoretical cycle for light-driven vertical movement. This suggests that water column stability and turbulence were more important factors in controlling vertical distribution of colonies than light. Variations at subseasonal time scales were determined by filtering data to pass periods between 1.2 and 15 days. At subseasonal time scales, correlations between RB and currents or air temperature were consistent with increased concentration of cyanobacterial colonies near the surface when water column stability increased (higher air temperatures or weaker currents) and dispersal of colonies throughout the water column when the water column mixed more easily. RB was used to estimate suspended solids concentrations (SSC). Correlations of depth-integrated SSC with currents or air temperatures suggest that depth-integrated water column mass decreased under conditions of greater water column stability and weaker currents. Results suggest that the use of measured vertical velocity and acoustic backscatter as a surrogate for suspended material has the potential to contribute significant additional insight into dynamics of Aphanizomenon flos-aquae colonies in Upper Klamath Lake, south-central Oregon.

Resource Assessment of Tidal Current Energy in Hangzhou Bay Based on Long Term Measurement

NASA Astrophysics Data System (ADS)

Zhang, Feng; Dai, Chun-Ni; Xu, Xue-Feng; Wang, Chuan-Kun; Ye, Qin

2017-05-01

Compared with other marine renewable energy, tidal current energy benefits a lot in high energy density and good predictability. Based on the measured tidal current data in Hangzhou Bay from Nov 2012 to Oct 2012, this paper analysed temporal and spatial changes of tidal current energy in the site. It is the first time measured data of such long time been taken in tidal current energy analysis. Occurrence frequency and duration of the current of different speed are given out in the paper. According to the analysis results, monthly average power density changed a lot in different month, and installation orientation of tidal current turbine significantly affected energy acquisition. Finally, the annual average power density of tidal current energy with coefficient Cp in the site was calculated, and final output of a tidal current plant was also estimated.

Extending the Constant Power Speed Range of the Brushless DC Motor through Dual Mode Inverter Control -- Part I: Theory and Simulation

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

Lawler, J.S.

2001-10-29

An inverter topology and control scheme has been developed that can drive low-inductance, surface-mounted permanent magnet motors over the wide constant power speed range required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC) [1]. The DMIC can drive either the Permanent Magnet Synchronous Machine (PMSM) with sinusoidal back emf, or the brushless dc machine (BDCM) with trapezoidal emf in the motoring and regenerative braking modes. In this paper we concentrate on the BDCM under high-speed motoring conditions. Simulation results show that if all motor and inverter loss mechanisms are neglected, the constant power speedmore » range of the DMIC is infinite. The simulation results are supported by closed form expressions for peak and rms motor current and average power derived from analytical solution to the differential equations governing the DMIC/BDCM drive for the lossless case. The analytical solution shows that the range of motor inductance that can be accommodated by the DMIC is more than an order of magnitude such that the DMIC is compatible with both low- and high-inductance BDCMs. Finally, method is given for integrating the classical hysteresis band current control, used for motor control below base speed, with the phase advance of DMIC that is applied above base speed. The power versus speed performance of the DMIC is then simulated across the entire speed range.« less

Deceleration of Fusion–Fission Cycles Improves Mitochondrial Quality Control during Aging

PubMed Central

Meyer-Hermann, Michael; Osiewacz, Heinz D.

2012-01-01

Mitochondrial dynamics and mitophagy play a key role in ensuring mitochondrial quality control. Impairment thereof was proposed to be causative to neurodegenerative diseases, diabetes, and cancer. Accumulation of mitochondrial dysfunction was further linked to aging. Here we applied a probabilistic modeling approach integrating our current knowledge on mitochondrial biology allowing us to simulate mitochondrial function and quality control during aging in silico. We demonstrate that cycles of fusion and fission and mitophagy indeed are essential for ensuring a high average quality of mitochondria, even under conditions in which random molecular damage is present. Prompted by earlier observations that mitochondrial fission itself can cause a partial drop in mitochondrial membrane potential, we tested the consequences of mitochondrial dynamics being harmful on its own. Next to directly impairing mitochondrial function, pre-existing molecular damage may be propagated and enhanced across the mitochondrial population by content mixing. In this situation, such an infection-like phenomenon impairs mitochondrial quality control progressively. However, when imposing an age-dependent deceleration of cycles of fusion and fission, we observe a delay in the loss of average quality of mitochondria. This provides a rational why fusion and fission rates are reduced during aging and why loss of a mitochondrial fission factor can extend life span in fungi. We propose the ‘mitochondrial infectious damage adaptation’ (MIDA) model according to which a deceleration of fusion–fission cycles reflects a systemic adaptation increasing life span. PMID:22761564

[Navigated control: a new concept in computer assisted ENT-surgery].

PubMed

Strauss, G; Koulechov, K; Richter, R; Dietz, A; Meixensberger, J; Trantakis, C; Lüth, T

2005-08-01

This work conceived and evaluates a mechatronical system for ORL-surgery by example of a Shaver for Functional Endoscopic Sinus Surgery controlled by navigation. The Shaver is automatically on/off-regulated depending on the current position in relation to the planned working space. This working space is defined on the basis of the individual CT data. Within this area the Shaver reacts to the signal of the surgeon (foot pedal). If the Shaver leaves the working space, an interruption of the drive regulation to the Shaver takes place. The evaluation of the planning software based on 32 patient CT-data sets. The registration accuracy in a anatomical model was examined on 451 measurements of endonasal attached titanium screws. The conversions of the working space were evaluated at 5 different technical models. The average time for segmenting the working space was found at 4.23 minutes per case. An average registration accuracy of the Shaver of 1.08 mm resulted. The pre-defined cavity was to be cleared away without restrictions. The preoperative determined work-space was converted by 3.1 mm over all levels. The study proves the feasibility of a mechatronical assistant system by the example of the navigate-controlled Shaver in paranasal sinus surgery. Contrary to conventional CAS solutions redundancy and cognitive discharge of the surgeon are considered in this conception. We see numerous applications according to the explained principle for power-control of instruments in ORL-surgery in the future such as drilling, high frequency surgery or laser.

The influence of executive capacity on selective attention and subsequent processing

PubMed Central

Daffner, Kirk R.; Tarbi, Elise C.; Haring, Anna E.; Zhuravleva, Tatyana Y.; Sun, Xue; Rentz, Dorene M.; Holcomb, Phillip J.

2012-01-01

Recent investigations that suggest selective attention (SA) is dependent on top-down control mechanisms lead to the expectation that individuals with high executive capacity (EC) would exhibit more robust neural indices of SA. This prediction was tested by using event-related potentials (ERPs) to examine differences in markers of information processing across 25 subjects divided into two groups based on high vs. average EC, as defined by neuropsychological test scores. Subjects performed an experimental task requiring SA to a specified color. In contrast to expectation, individuals with high and average EC did not differ in the size of ERP indices of SA: the anterior Selection Positivity (SP) and posterior Selection Negativity (SN). However, there were substantial differences between groups in markers of subsequent processing, including the anterior N2 (a measure of attentional control) and the P3a (an index of the orienting of attention). EC predicted speed of processing at both early and late attentional stages. Individuals with lower EC exhibited prolonged SN, P3a, and P3b latencies. However, the delays in carrying out SA operations did not account for subsequent delays in decision making, or explain excessive orienting and reduced attentional control mechanisms in response to stimuli that should have been ignored. SN latency, P3 latency, and the size of the anterior N2 made independent contributions to the variance of EC. In summary, our findings suggest that current views regarding the relationship between top-down control mechanisms and SA may need refinement. PMID:22701415

Effects of an intervention aimed at reducing the intake of sugar-sweetened beverages in primary school children: a controlled trial

PubMed Central

2014-01-01

Background Since sugar-sweetened beverages (SSB) may contribute to the development of overweight in children, effective interventions to reduce their consumption are needed. Here we evaluated the effect of a combined school- and community-based intervention aimed at reducing children’s SSB consumption by promoting the intake of water. Favourable intervention effects on children’s SSB consumption were hypothesized. Methods In 2011-2012, a controlled trial was conducted among four primary schools, comprising 1288 children aged 6-12 years who lived in multi-ethnic, socially deprived neighbourhoods in Rotterdam, the Netherlands. Intervention schools adopted the ‘water campaign’, an intervention developed using social marketing. Control schools continued with their regular health promotion programme. Primary outcome was children’s SSB consumption, measured using parent and child questionnaires and through observations at school, both at baseline and after one year of intervention. Results Significant positive intervention effects were found for average SSB consumption (B -0.19 litres, 95% CI -0.28;-0.10; parent report), average SSB servings (B -0.54 servings, 95% CI -0.82;-0.26; parent report) and bringing SSB to school (OR 0.51, 95% CI 0.36;0.72; observation report). Conclusions This study supports the effectiveness of the water campaign intervention in reducing children’s SSB consumption. Further studies are needed to replicate our findings. Trial registration Current Controlled Trials: NTR3400 PMID:25060113

The effects of price and perceived quality on the behavioural economics of alcohol, amphetamine, cannabis, cocaine, and ecstasy purchases.

PubMed

Goudie, Andrew J; Sumnall, Harry R; Field, Matt; Clayton, Hannah; Cole, Jon C

2007-07-10

Behavioural economic models of substance use describe the relationship between changes in unit price and consumption. However, these models rarely take account of the perceived quality (i.e. potency) of controlled drugs. Therefore we investigated the effects of both price and quality on the decision to purchase controlled drugs by polysubstance misusers. Forty current polysubstance misusers (29 males, 11 females; mean age 23.8) were recruited into the study. Participants were asked to hypothetically purchase drugs from a price list of alcohol, amphetamine, cannabis, cocaine and ecstasy at different levels of quality and price (i.e. better quality drugs cost more money). The disposable income available for those purchases was systematically varied in order to determine the impact of income on the decision to purchase drugs. Demand for both normal and strong alcohol was income inelastic. Demand for both poor and average quality cannabis and ecstasy was income inelastic, but demand for good quality cannabis and ecstasy was income elastic. The demand for poor quality cocaine was income inelastic, with the demand for both average and good quality cocaine being income elastic. Participants reported too few purchases of amphetamine, which precluded behavioural economic analysis. These results suggest that, like other goods, controlled drugs are purchased based upon the consumer's interpretations of their relative value. Therefore, it is probable that the purchase and subsequent use of controlled drugs by polysubstance misusers will be heavily influenced by the economic environment.

Adolescent smoking and volume of exposure to various forms of media.

PubMed

Primack, Brian A; Land, Stephanie R; Fine, Michael J

2008-04-01

To assess the association between adolescent smoking and volume of exposure to various forms of media after controlling for multiple relevant covariates. A survey of all adolescents at a large suburban high school assessed: (1) current smoking and susceptibility to future smoking; (2) volume of exposure to various media; and (3) covariates related to smoking. Multivariate logistic regression models assessed relationships between each of the independent variables (media exposures) and the two smoking outcomes after controlling for covariates. Of the 1138 respondents, 19% (n=216) reported current smoking. Forty percent (n=342) of the non-smokers (n=922) were susceptible to future smoking. Students reported exposure to an average of 8.6 (standard deviation 5.1)h of media daily, including 2.6h of music. Those with high exposure to films and music were more likely to be smokers (P(trend)=0.036 and P(trend)<0.001, respectively), and those with high exposure to books were less likely to be smokers (P(trend)<0.001). After controlling for all relevant covariates, those with high exposure to music had greater odds of being smokers than those with low exposure [odds ratio (OR) 1.90, 95% confidence intervals (CI) 1.10-3.30], and those with high exposure to books had lower odds of being current smokers (OR 0.55, 95% CI 0.33-0.94). Exposure to films and music are associated with smoking, but only the relationship between music exposure and smoking persists after rigorous covariate control. Exposure to books is associated with lower odds of smoking.

Soil nitrogen cycling and nitrous oxide flux in a Rocky Mountain Douglas-fir forest - Effects of fertilization, irrigation and carbon addition

NASA Technical Reports Server (NTRS)

Matson, Pamela A.; Gower, Stith T.; Volkmann, Carol; Billow, Christine; Grier, Charles C.

1992-01-01

Nitrous oxide fluxes and soil nitrogen transformations were measured in experimentally-treated high elevation Douglas-fir forests in northwestern New Mexico. On an annual basis, forests that were fertilized with 200 kg N/ha emitted an average of 0.66 kg/ha of N2O-N, with highest fluxes occurring in July and August when soils were both warm and wet. Control, irrigated, and woodchip treated plots were not different from each other, and annual average fluxes ranged from 0.03 to 0.23 kg/ha. Fertilized soil mineralized 277 kg/ha per year in contrast to 18 kg/ha per year in control plots. Relative recovery of (N-15)H4-N applied to soil in laboratory incubations was principally in the form of NO3-N in the fertilized soils, while recovery was mostly in microbial biomass-N in the other treatments. Fertilization apparently added nitrogen that exceeded the heterotrophic microbial demand, resulting in higher rates of nitrate production and higher nitrous oxide fluxes. Global inputs of nitrogen into forests are not currently contributing significantly to the increasing concentrations of nitrous oxide in the atmosphere.

Understanding the relationship between student attitudes and student learning

NASA Astrophysics Data System (ADS)

Cahill, Michael J.; McDaniel, Mark A.; Frey, Regina F.; Hynes, K. Mairin; Repice, Michelle; Zhao, Jiuqing; Trousil, Rebecca

2018-02-01

Student attitudes, defined as the extent to which one holds expertlike beliefs about and approaches to physics, are a major research topic in physics education research. An implicit but rarely tested assumption underlying much of this research is that student attitudes play a significant part in student learning and performance. The current study directly tested this attitude-learning link by measuring the association between incoming attitudes (Colorado Learning Attitudes about Science Survey) and student learning during the semester after statistically controlling for the effects of prior knowledge [early-semester Force Concept Inventory (FCI) or Brief Electricity and Magnetism Assessment (BEMA)]. This study spanned four different courses and included two complementary measures of student knowledge: late-semester concept inventory scores (FCI or BEMA) and exam averages. In three of the four courses, after controlling for prior knowledge, attitudes significantly predicted both late-semester concept inventory scores and exam averages, but in all cases these attitudes explained only a small amount of variance in concept-inventory and exam scores. Results indicate that after accounting for students' incoming knowledge, attitudes may uniquely but modestly relate to how much students learn and how well they perform in the course.

Tracking of electrochemical impedance of batteries

NASA Astrophysics Data System (ADS)

Piret, H.; Granjon, P.; Guillet, N.; Cattin, V.

2016-04-01

This paper presents an evolutionary battery impedance estimation method, which can be easily embedded in vehicles or nomad devices. The proposed method not only allows an accurate frequency impedance estimation, but also a tracking of its temporal evolution contrary to classical electrochemical impedance spectroscopy methods. Taking into account constraints of cost and complexity, we propose to use the existing electronics of current control to perform a frequency evolutionary estimation of the electrochemical impedance. The developed method uses a simple wideband input signal, and relies on a recursive local average of Fourier transforms. The averaging is controlled by a single parameter, managing a trade-off between tracking and estimation performance. This normalized parameter allows to correctly adapt the behavior of the proposed estimator to the variations of the impedance. The advantage of the proposed method is twofold: the method is easy to embed into a simple electronic circuit, and the battery impedance estimator is evolutionary. The ability of the method to monitor the impedance over time is demonstrated on a simulator, and on a real Lithium ion battery, on which a repeatability study is carried out. The experiments reveal good tracking results, and estimation performance as accurate as the usual laboratory approaches.

Capture, Learning, and Classification of Upper Extremity Movement Primitives in Healthy Controls and Stroke Patients

PubMed Central

Guerra, Jorge; Uddin, Jasim; Nilsen, Dawn; Mclnerney, James; Fadoo, Ammarah; Omofuma, Isirame B.; Hughes, Shatif; Agrawal, Sunil; Allen, Peter; Schambra, Heidi M.

2017-01-01

There currently exist no practical tools to identify functional movements in the upper extremities (UEs). This absence has limited the precise therapeutic dosing of patients recovering from stroke. In this proof-of-principle study, we aimed to develop an accurate approach for classifying UE functional movement primitives, which comprise functional movements. Data were generated from inertial measurement units (IMUs) placed on upper body segments of older healthy individuals and chronic stroke patients. Subjects performed activities commonly trained during rehabilitation after stroke. Data processing involved the use of a sliding window to obtain statistical descriptors, and resulting features were processed by a Hidden Markov Model (HMM). The likelihoods of the states, resulting from the HMM, were segmented by a second sliding window and their averages were calculated. The final predictions were mapped to human functional movement primitives using a Logistic Regression algorithm. Algorithm performance was assessed with a leave-one-out analysis, which determined its sensitivity, specificity, and positive and negative predictive values for all classified primitives. In healthy control and stroke participants, our approach identified functional movement primitives embedded in training activities with, on average, 80% precision. This approach may support functional movement dosing in stroke rehabilitation. PMID:28813877

Defining level A IVIVC dissolution specifications based on individual in vitro dissolution profiles of a controlled release formulation.

PubMed

González-García, I; García-Arieta, A; Merino-Sanjuan, M; Mangas-Sanjuan, V; Bermejo, M

2018-07-01

Regulatory guidelines recommend that, when a level A IVIVC is established, dissolution specification should be established using averaged data and the maximum difference between AUC and C max between the reference and test formulations cannot be greater than 20%. However, averaging data assumes a loss of information and may reflect a bias in the results. The objective of the current work is to present a new approach to establish dissolution specifications using a new methodology (individual approach) instead of average data (classical approach). Different scenarios were established based on the relationship between in vitro-in vivo dissolution rate coefficient using a level A IVIVC of a controlled release formulation. Then, in order to compare this new approach with the classical one, six additional batches were simulated. For each batch, 1000 simulations of a dissolution assay were run. C max ratios between the reference formulation and each batch were calculated showing that the individual approach was more sensitive and able to detect differences between the reference and the batch formulation compared to the classical approach. Additionally, the new methodology displays wider dissolution specification limits than the classical approach, ensuring that any tablet from the new batch would generate in vivo profiles which its AUC or C max ratio will be out of the 0.8-1.25 range, taking into account the in vitro and in vivo variability of the new batches developed. Copyright © 2018 Elsevier B.V. All rights reserved.

On a distinctive feature of problems of calculating time-average characteristics of nuclear reactor optimal control sets

NASA Astrophysics Data System (ADS)

Trifonenkov, A. V.; Trifonenkov, V. P.

2017-01-01

This article deals with a feature of problems of calculating time-average characteristics of nuclear reactor optimal control sets. The operation of a nuclear reactor during threatened period is considered. The optimal control search problem is analysed. The xenon poisoning causes limitations on the variety of statements of the problem of calculating time-average characteristics of a set of optimal reactor power off controls. The level of xenon poisoning is limited. There is a problem of choosing an appropriate segment of the time axis to ensure that optimal control problem is consistent. Two procedures of estimation of the duration of this segment are considered. Two estimations as functions of the xenon limitation were plot. Boundaries of the interval of averaging are defined more precisely.

Time-evolution of photon heat current through series coupled two mesoscopic Josephson junction devices

NASA Astrophysics Data System (ADS)

Lu, Wen-Ting; Zhao, Hong-Kang; Wang, Jian

2018-03-01

Photon heat current tunneling through a series coupled two mesoscopic Josephson junction (MJJ) system biased by dc voltages has been investigated by employing the nonequilibrium Green’s function approach. The time-oscillating photon heat current is contributed by the superposition of different current branches associated with the frequencies of MJJs ω j (j = 1, 2). Nonlinear behaviors are exhibited to be induced by the self-inductance, Coulomb interaction, and interference effect relating to the coherent transport of Cooper pairs in the MJJs. Time-oscillating pumping photon heat current is generated in the absence of temperature difference, while it becomes zero after time-average. The combination of ω j and Coulomb interactions in the MJJs determines the concrete heat current configuration. As the external and intrinsic frequencies ω j and ω 0 of MJJs match some specific combinations, resonant photon heat current exhibits sinusoidal behaviors with large amplitudes. Symmetric and asymmetric evolutions versus time t with respect to ω 1 t and ω 2 t are controlled by the applied dc voltages of V 1 and V 2. The dc photon heat current formula is a special case of the general time-dependent heat current formula when the bias voltages are settled to zero. The Aharonov-Bohm effect has been investigated, and versatile oscillation structures of photon heat current can be achieved by tuning the magnetic fluxes threading through separating MJJs.

The new nordic diet--consumer expenditures and economic incentives estimated from a controlled intervention.

PubMed

Jensen, Jørgen Dejgård; Poulsen, Sanne Kellebjerg

2013-12-02

Several studies suggest that a healthy diet with high emphasis on nutritious, low-energy components such as fruits, vegetables, and seafood tends to be more costly for consumers. Derived from the ideas from the New Nordic Cuisine--and inspired by the Mediterranean diet, the New Nordic Diet (NND) has been developed as a palatable, healthy and sustainable diet based on products from the Nordic region. The objective of the study is to investigate economic consequences for the consumers of the NND, compared with an Average Danish Diet (ADD). Combine quantity data from a randomized controlled ad libitum dietary 6 month intervention for central obese adults (18-65 years) and market retail price data of the products consumed in the intervention. Adjust consumed quantities to market price incentives using econometrically estimated price elasticities. Average daily food expenditure of the ADD as represented in the unadjusted intervention (ADD-i) amounted to 36.02 DKK for the participants. The daily food expenditure in the unadjusted New Nordic Diet (NND-i) costs 44.80 DKK per day per head, and is hence about 25% more expensive than the Average Danish Diet (or about 17% when adjusting for energy content of the diet). Adjusting for price incentives in a real market setting, the estimated cost of the Average Danish Diet is reduced by 2.50 DKK (ADD-m), compared to the unadjusted ADD-i diet, whereas the adjusted cost of the New Nordic Diet (NND-m) is reduced by about 3.50 DKK, compared to the unadjusted NND-i. The distribution of food cost is however much more heterogeneous among consumers within the NND than within the ADD. On average, the New Nordic Diet is 24-25 per cent more expensive than an Average Danish Diet at the current market prices in Denmark (and 16-17 per cent, when adjusting for energy content). The relatively large heterogeneity in food costs in the NND suggests that it is possible to compose an NND where the cost exceeds that of ADD by less than the 24-25 per cent.

Effects of microclimatic variables on the symptoms and signs onset of Moniliophthora roreri, causal agent of Moniliophthora pod rot in cacao

PubMed Central

Tixier, Philippe; Germon, Amandine; Rakotobe, Veromanitra; Phillips-Mora, Wilbert; Maximova, Siela; Avelino, Jacques

2017-01-01

Moniliophthora Pod Rot (MPR) caused by the fungus Moniliophthora roreri (Cif.) Evans et al., is one of the main limiting factors of cocoa production in Latin America. Currently insufficient information on the biology and epidemiology of the pathogen limits the development of efficient management options to control MPR. This research aims to elucidate MPR development through the following daily microclimatic variables: minimum and maximum temperatures, wetness frequency, average temperature and relative humidity in the highly susceptible cacao clone Pound-7 (incidence = 86% 2008–2013 average). A total of 55 cohorts totaling 2,268 pods of 3–10 cm length, one to two months of age, were tagged weekly. Pods were assessed throughout their lifetime, every one or two weeks, and classified in 3 different categories: healthy, diseased with no sporulation, diseased with sporulating lesions. As a first step, we used Generalized Linear Mixed Models (GLMM) to determine with no a priori the period (when and for how long) each climatic variable was better related with the appearance of symptoms and sporulation. Then the significance of the candidate variables was tested in a complete GLMM. Daily average wetness frequency from day 14 to day 1, before tagging, and daily average maximum temperature from day 4 to day 21, after tagging, were the most explanatory variables of the symptoms appearance. The former was positively linked with the symptoms appearance when the latter exhibited a maximum at 30°C. The most important variables influencing sporulation were daily average minimum temperature from day 35 to day 58 and daily average maximum temperature from day 37 to day 48, both after tagging. Minimum temperature was negatively linked with the sporulation while maximum temperature was positively linked. Results indicated that the fungal microclimatic requirements vary from the early to the late cycle stages, possibly due to the pathogen’s long latent period. This information is valuable for development of new conceptual models for MPR and improvement of control methods. PMID:28972981

Effects of microclimatic variables on the symptoms and signs onset of Moniliophthora roreri, causal agent of Moniliophthora pod rot in cacao.

PubMed

Leandro-Muñoz, Mariela E; Tixier, Philippe; Germon, Amandine; Rakotobe, Veromanitra; Phillips-Mora, Wilbert; Maximova, Siela; Avelino, Jacques

2017-01-01

Moniliophthora Pod Rot (MPR) caused by the fungus Moniliophthora roreri (Cif.) Evans et al., is one of the main limiting factors of cocoa production in Latin America. Currently insufficient information on the biology and epidemiology of the pathogen limits the development of efficient management options to control MPR. This research aims to elucidate MPR development through the following daily microclimatic variables: minimum and maximum temperatures, wetness frequency, average temperature and relative humidity in the highly susceptible cacao clone Pound-7 (incidence = 86% 2008-2013 average). A total of 55 cohorts totaling 2,268 pods of 3-10 cm length, one to two months of age, were tagged weekly. Pods were assessed throughout their lifetime, every one or two weeks, and classified in 3 different categories: healthy, diseased with no sporulation, diseased with sporulating lesions. As a first step, we used Generalized Linear Mixed Models (GLMM) to determine with no a priori the period (when and for how long) each climatic variable was better related with the appearance of symptoms and sporulation. Then the significance of the candidate variables was tested in a complete GLMM. Daily average wetness frequency from day 14 to day 1, before tagging, and daily average maximum temperature from day 4 to day 21, after tagging, were the most explanatory variables of the symptoms appearance. The former was positively linked with the symptoms appearance when the latter exhibited a maximum at 30°C. The most important variables influencing sporulation were daily average minimum temperature from day 35 to day 58 and daily average maximum temperature from day 37 to day 48, both after tagging. Minimum temperature was negatively linked with the sporulation while maximum temperature was positively linked. Results indicated that the fungal microclimatic requirements vary from the early to the late cycle stages, possibly due to the pathogen's long latent period. This information is valuable for development of new conceptual models for MPR and improvement of control methods.

The Impact of Sea Ice Concentration Accuracies on Climate Model Simulations with the GISS GCM

NASA Technical Reports Server (NTRS)

Parkinson, Claire L.; Rind, David; Healy, Richard J.; Martinson, Douglas G.; Zukor, Dorothy J. (Technical Monitor)

2000-01-01

The Goddard Institute for Space Studies global climate model (GISS GCM) is used to examine the sensitivity of the simulated climate to sea ice concentration specifications in the type of simulation done in the Atmospheric Modeling Intercomparison Project (AMIP), with specified oceanic boundary conditions. Results show that sea ice concentration uncertainties of +/- 7% can affect simulated regional temperatures by more than 6 C, and biases in sea ice concentrations of +7% and -7% alter simulated annually averaged global surface air temperatures by -0.10 C and +0.17 C, respectively, over those in the control simulation. The resulting 0.27 C difference in simulated annual global surface air temperatures is reduced by a third, to 0.18 C, when considering instead biases of +4% and -4%. More broadly, least-squares fits through the temperature results of 17 simulations with ice concentration input changes ranging from increases of 50% versus the control simulation to decreases of 50% yield a yearly average global impact of 0.0107 C warming for every 1% ice concentration decrease, i.e., 1.07 C warming for the full +50% to -50% range. Regionally and on a monthly average basis, the differences can be far greater, especially in the polar regions, where wintertime contrasts between the +50% and -50% cases can exceed 30 C. However, few statistically significant effects are found outside the polar latitudes, and temperature effects over the non-polar oceans tend to be under 1 C, due in part to the specification of an unvarying annual cycle of sea surface temperatures. The +/- 7% and 14% results provide bounds on the impact (on GISS GCM simulations making use of satellite data) of satellite-derived ice concentration inaccuracies, +/- 7% being the current estimated average accuracy of satellite retrievals and +/- 4% being the anticipated improved average accuracy for upcoming satellite instruments. Results show that the impact on simulated temperatures of imposed ice concentration changes is least in summer, encouragingly the same season in which the satellite accuracies are thought to be worst. Hence the impact of satellite inaccuracies is probably less than the use of an annually averaged satellite inaccuracy would suggest.

The new nordic diet – consumer expenditures and economic incentives estimated from a controlled intervention

PubMed Central

2013-01-01

Background Several studies suggest that a healthy diet with high emphasis on nutritious, low-energy components such as fruits, vegetables, and seafood tends to be more costly for consumers. Derived from the ideas from the New Nordic Cuisine – and inspired by the Mediterranean diet, the New Nordic Diet (NND) has been developed as a palatable, healthy and sustainable diet based on products from the Nordic region. The objective of the study is to investigate economic consequences for the consumers of the NND, compared with an Average Danish Diet (ADD). Methods Combine quantity data from a randomized controlled ad libitum dietary 6 month intervention for central obese adults (18–65 years) and market retail price data of the products consumed in the intervention. Adjust consumed quantities to market price incentives using econometrically estimated price elasticities. Results Average daily food expenditure of the ADD as represented in the unadjusted intervention (ADD-i) amounted to 36.02 DKK for the participants. The daily food expenditure in the unadjusted New Nordic Diet (NND-i) costs 44.80 DKK per day per head, and is hence about 25% more expensive than the Average Danish Diet (or about 17% when adjusting for energy content of the diet). Adjusting for price incentives in a real market setting, the estimated cost of the Average Danish Diet is reduced by 2.50 DKK (ADD-m), compared to the unadjusted ADD-i diet, whereas the adjusted cost of the New Nordic Diet (NND-m) is reduced by about 3.50 DKK, compared to the unadjusted NND-i. The distribution of food cost is however much more heterogeneous among consumers within the NND than within the ADD. Conclusion On average, the New Nordic Diet is 24–25 per cent more expensive than an Average Danish Diet at the current market prices in Denmark (and 16–17 per cent, when adjusting for energy content). The relatively large heterogeneity in food costs in the NND suggests that it is possible to compose an NND where the cost exceeds that of ADD by less than the 24–25 per cent. PMID:24294977

Nicotine at clinically relevant concentrations affects atrial inward rectifier potassium current sensitive to acetylcholine.

PubMed

Bébarová, Markéta; Matejovič, Peter; Švecová, Olga; Kula, Roman; Šimurdová, Milena; Šimurda, Jiří

2017-05-01

Nicotine abuse is associated with variety of diseases including arrhythmias, most often atrial fibrillation (AF). Altered inward rectifier potassium currents including acetylcholine-sensitive current I K(Ach) are known to be related to AF pathogenesis. Since relevant data are missing, we aimed to investigate I K(Ach) changes at clinically relevant concentrations of nicotine. Experiments were performed by the whole cell patch clamp technique at 23 ± 1 °C on isolated rat atrial myocytes. Nicotine was applied at following concentrations: 4, 40 and 400 nM; ethanol at 20 mM (∼0.09%). Nicotine at 40 and 400 nM significantly activated constitutively active component of I K(Ach) with the maximum effect at 40 nM (an increase by ∼100%); similar effect was observed at -110 and -50 mV. Changes at 4 nM nicotine were negligible on average. Coapplication of 40 nM nicotine and 20 mM ethanol (which is also known to activate this current) did not show cumulative effect. In the case of acetylcholine-induced component of I K(Ach) , a dual effect of nicotine and its correlation with the current magnitude in control were apparent: the current was increased by nicotine in the cells showing small current in control and vice versa. The effect of 40 and 400 nM nicotine on acetylcholine-induced component of I K(Ach) was significantly different at -110 and -50 mV. We conclude that nicotine at clinically relevant concentrations significantly increased constitutively active component of I K(Ach) and showed a dual effect on its acetylcholine-induced component, similarly as ethanol. Synchronous application of nicotine and ethanol did not cause additive effect.

Effect of ethanol at clinically relevant concentrations on atrial inward rectifier potassium current sensitive to acetylcholine.

PubMed

Bébarová, Markéta; Matejovič, Peter; Pásek, Michal; Hořáková, Zuzana; Hošek, Jan; Šimurdová, Milena; Šimurda, Jiří

2016-10-01

Alcohol intoxication tends to induce arrhythmias, most often the atrial fibrillation. To elucidate arrhythmogenic mechanisms related to alcohol consumption, the effect of ethanol on main components of the ionic membrane current is investigated step by step. Considering limited knowledge, we aimed to examine the effect of clinically relevant concentrations of ethanol (0.8-80 mM) on acetylcholine-sensitive inward rectifier potassium current I K(Ach). Experiments were performed by the whole-cell patch clamp technique at 23 ± 1 °C on isolated rat and guinea-pig atrial myocytes, and on expressed human Kir3.1/3.4 channels. Ethanol induced changes of I K(Ach) in the whole range of concentrations applied; the effect was not voltage dependent. The constitutively active component of I K(Ach) was significantly increased by ethanol with the maximum effect (an increase by ∼100 %) between 8 and 20 mM. The changes were comparable in rat and guinea-pig atrial myocytes and also in expressed human Kir3.1/3.4 channels (i.e., structural correlate of I K(Ach)). In the case of the acetylcholine-induced component of I K(Ach), a dual ethanol effect was apparent with a striking heterogeneity of changes in individual cells. The effect correlated with the current magnitude in control: the current was increased by eth-anol in the cells showing small current in control and vice versa. The average effect peaked at 20 mM ethanol (an increase of the current by ∼20 %). Observed changes of action potential duration agreed well with the voltage clamp data. Ethanol significantly affected both components of I K(Ach) even in concentrations corresponding to light alcohol consumption.

Study on characteristics of the aperture-averaging factor of atmospheric scintillation in terrestrial optical wireless communication

NASA Astrophysics Data System (ADS)

Shen, Hong; Liu, Wen-xing; Zhou, Xue-yun; Zhou, Li-ling; Yu, Long-Kun

2018-02-01

In order to thoroughly understand the characteristics of the aperture-averaging effect of atmospheric scintillation in terrestrial optical wireless communication and provide references for engineering design and performance evaluation of the optics system employed in the atmosphere, we have theoretically deduced the generally analytic expression of the aperture-averaging factor of atmospheric scintillation, and numerically investigated characteristics of the apertureaveraging factor under different propagation conditions. The limitations of the current commonly used approximate calculation formula of aperture-averaging factor have been discussed, and the results showed that the current calculation formula is not applicable for the small receiving aperture under non-uniform turbulence link. Numerical calculation has showed that aperture-averaging factor of atmospheric scintillation presented an exponential decline model for the small receiving aperture under non-uniform turbulent link, and the general expression of the model was given. This model has certain guiding significance for evaluating the aperture-averaging effect in the terrestrial optical wireless communication.

Nanowire Tunnel Field Effect Transistors: Prospects and Pitfalls

NASA Astrophysics Data System (ADS)

Sylvia, Somaia Sarwat

The tunnel field effect transistor (TFET) has the potential to operate at lower voltages and lower power than the field effect transistor (FET). The TFET can circumvent the fundamental thermal limit of the inverse subthreshold slope (S) by exploiting interband tunneling of non-equilibrium "cold" carriers. The conduction mechanism in the TFET is governed by band-to-band tunneling which limits the drive current. TFETs built with III-V materials like InAs and InSb can produce enough tunneling current because of their small direct bandgap. Our simulation results show that although they require highly degenerate source doping to support the high electric fields in the tunnel region, the devices achieve minimum inverse subthreshold slopes of 30 mV/dec. In subthreshold, these devices experience both regimes of voltage-controlled tunneling and cold-carrier injection. Numerical results based on a discretized 8-band k.p model are compared to analytical WKB theory. For both regular FETs and TFETs, direct channel tunneling dominates the leakage current when the physical gate length is reduced to 5 nm. Therefore, a survey of materials is performed to determine their ability to suppress the direct tunnel current through a 5 nm barrier. The tunneling effective mass gives the best indication of the relative size of the tunnel currents. Si gives the lowest overall tunnel current for both the conduction and valence band and, therefore, it is the optimum choice for suppressing tunnel current at the 5 nm scale. Our numerical simulation shows that the finite number, random placement, and discrete nature of the dopants in the source of an InAs nanowire (NW) TFET affect both the mean value and the variance of the drive current and the inverse subthreshold slope. The discrete doping model gives an average drive current and an inverse subthreshold slope that are less than those predicted from the homogeneous doping model. The doping density required to achieve a target drive current is higher in the discrete doping model compared to the homogeneous doping model. The relative variation in the ON current decreases as the average doping density and/or NW diameter increases. For the largest 8 nm NW studied, the coefficient of variation in the ON current is ˜15% at a doping density of 1.5 x 1020 cm--3. Results from full self-consistent non-equilibrium Green's function calculations and semi-classical calculations are compared.

Assessment of Lead Exposure Risk in Locksmiths

PubMed Central

Kondrashov, Vladislav; McQuirter, Joseph L.; Miller, Melba; Rothenberg, Stephen J.

2005-01-01

Exposure to lead has been well recognized in a number of work environments, but little is known about lead exposure associated with machining brass keys containing lead. The brass that is widely used for key manufacturing usually contains 1.5% – 2.5 % of lead. Six (6) licensed locksmiths and 6 case-matched controls successfully completed the pilot study to assess the prevalence of increased body lead burden of professional locksmiths. We measured both Blood Lead (atomic absorption spectrometry), bone-lead (KXRF) and had each subject complete a health and lead exposure risk questionnaire. One locksmith had not cut keys during the past two years, therefore this subject and case-matched control was excluded from the blood lead analysis only. The average blood-lead concentration (±SEM) for the 5 paired subjects was 3.1 (± 0.4) μg/dL and 2.2 (± 0.3) μg /dL for controls. Bone measurements, including all 6 paired subjects, showed tibia lead concentration (±SEM) for locksmiths and controls was 27.8 (± 2.3) μg /g and 13.7 (± 3.3) μg /g, respectively; average calcaneus lead concentration for locksmiths and controls was 31.9 (± 3.7) μg /g and 22.6 (± 4.1) μg /g, respectively: The t-test shows a significantly higher tibia lead (p<0.05) and blood lead (p<0.05) for locksmiths than for their matched controls, but no significant difference for calcaneus lead (p>0.10). Given that the mean tibia bone lead concentration was 13.1μg/g higher in locksmiths than in their matched controls, this average difference in the two groups would translate to an OR of increased hypertension in locksmiths of between 1.1 and 2.3, based on the published literature. Even with the very small number of subjects participating in this pilot study, we were able to demonstrate that locksmiths had significantly higher current exposure to lead (blood lead concentration) and significantly higher past exposure to lead (tibia lead concentration) than their age, sex and ethnically matched controls. Additional research is needed to fully identify the prevalence and associated risk factors for occupational exposure of lead in this previously understudied profession. PMID:16705814

Measurement of scrape-off-layer current dynamics during MHD activity and disruptions in HBT-EP

NASA Astrophysics Data System (ADS)

Levesque, J. P.; Brooks, J. W.; Abler, M. C.; Bialek, J.; Byrne, P. J.; Hansen, C. J.; Hughes, P. E.; Mauel, M. E.; Navratil, G. A.; Rhodes, D. J.

2017-08-01

We report scrape-off layer (SOL) current measurements during magnetohydrodynamic (MHD) mode activity, resonant magnetic perturbations (RMPs), and disruptions in the High Beta Tokamak—Extended Pulse (HBT-EP) device. Currents are measured via segmented plasma current Rogowski coils, jumpers running toroidally between otherwise-isolated vessel sections, and a grounded electrode in the scrape-off layer. These currents strongly depend on the plasma’s major radius, and amplitude and phase of non-axisymmetric field components. SOL currents connecting through the vessel are seen to reach  ∼0.2{--}0.5 % of the plasma current during typical kink activity and RMPs. Plasma current asymmetries and scrape-off-layer currents generated during disruptions, which are commonly called halo currents, reach  ∼4 % of I p. Asymmetric toroidal currents between vessel sections rotate at tens of kHz through most of the current quench, then symmetrize once I p reaches  ∼30 % of its pre-disruptive value. Toroidal jumper currents oscillate between co- and counter-I p, with co-I p being dominant on average during disruptions. A relative increase in local plasma current measured by a segmented I p Rogowski coil correlates with counter-I p current in the nearest toroidal jumper. Measurements are interpreted in the context of two models that produce contrary predictions for the toroidal vessel current polarity during disruptions. Plasma current asymmetry measurements are consistent with both models, and SOL currents scale with plasma displacement toward the vessel wall. The design of an upcoming SOL current diagnostic and control upgrade is also briefly presented.

A transgenic study on affecting potato tuber yield by expressing the rice sucrose transporter genes OsSUT5Z and OsSUT2M.

PubMed

Sun, Aijun; Dai, Yan; Zhang, Xinsheng; Li, Chunmin; Meng, Kun; Xu, Honglin; Wei, Xiaoli; Xiao, Guifang; Ouwerkerk, Pieter B F; Wang, Mei; Zhu, Zhen

2011-07-01

In many plants, sucrose transporters are essential for both sucrose exports from sources and imports into sinks, indicating a function in assimilate partitioning. To investigate whether sucrose transporters can improve the yield of starch plant, potato plants (Solanum tuberosum L. cv. Désirée) were transformed with cDNAs of the rice sucrose transporter genes OsSUT5Z and OsSUT2M under the control of a tuber-specific, class-I patatin promoter. Compared to the controls, the average fructose content of OsSUT5Z transgenic tubers significantly increased. However, the content of the sugars and starch in the OsSUT2M transgenic potato tubers showed no obvious difference. Correspondingly, the average tuber yield, average number of tubers per plant and average weight of single tuber showed no significant difference in OsSUT2M transgenic tubers with controls. In the OsSUT5Z transgenic lines, the average tuber yield per plant was 1.9-fold higher than the controls, and the average number of tubers per plant increased by more than 10 tubers on average, whereas the average weight of a single tuber did not increase significantly. These results suggested that the average number of tubers per plant showed more contribution than the average weight of a single tuber to the tuber yield per plant. © 2011 Institute of Botany, Chinese Academy of Sciences.

40 CFR 1051.740 - Are there special averaging provisions for snowmobiles?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Averaging... redesignated engines. Calculate credits using this average emission level relative to the specific pollutant in... equation in § 1051.103), then your credits are the difference between the Phase 3 reduction requirement of...

40 CFR 1051.740 - Are there special averaging provisions for snowmobiles?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Averaging... redesignated engines. Calculate credits using this average emission level relative to the specific pollutant in... equation in § 1051.103), then your credits are the difference between the Phase 3 reduction requirement of...

Biological Control Products for Aflatoxin Prevention in Italy: Commercial Field Evaluation of Atoxigenic Aspergillus flavus Active Ingredients.

PubMed

Mauro, Antonio; Garcia-Cela, Esther; Pietri, Amedeo; Cotty, Peter J; Battilani, Paola

2018-01-05

Since 2003, non-compliant aflatoxin concentrations have been detected in maize produced in Italy. The most successful worldwide experiments in aflatoxin prevention resulted from distribution of atoxigenic strains of Aspergillus flavus to displace aflatoxin-producers during crop development. The displacement results in lower aflatoxin concentrations in harvested grain. The current study evaluated in field performances of two atoxigenic strains of A . flavus endemic to Italy in artificially inoculated maize ears and in naturally contaminated maize. Co-inoculation of atoxigenic strains with aflatoxin producers resulted in highly significant reductions in aflatoxin concentrations (>90%) in both years only with atoxigenic strain A2085. The average percent reduction in aflatoxin B₁ concentration in naturally contaminated maize fields was 92.3%, without significant differences in fumonisins between treated and control maize. The vegetative compatibility group of A2085 was the most frequently recovered A. flavus in both treated and control plots (average 61.9% and 53.5% of the A. flavus , respectively). A2085 was therefore selected as an active ingredient for biocontrol products and deposited under provisions of the Budapest Treaty in the Belgian Co-Ordinated Collections of Micro-Organisms (BCCM/MUCL) collection (accession MUCL54911). Further work on development of A2085 as a tool for preventing aflatoxin contamination in maize produced in Italy is ongoing with the commercial product named AF-X1™.

[Chromium supplementation in patients with type 2 diabetes and high risk of type 2 diabetes: a meta-analysis of randomized controlled trials].

PubMed

San Mauro-Martin, Ismael; Ruiz-León, Ana María; Camina-Martín, María Alicia; Garicano-Vilar, Elena; Collado-Yurrita, Luis; Mateo-Silleras, Beatriz de; Redondo Del Río, María De Paz

2016-02-16

Chromium is an essential trace mineral for carbohydrate and lipid metabolism, which is currently prescribed to control diabetes mellitus. Results of previous systematic reviews and meta-analyses of chromium supplementation and metabolic profiles in diabetes have been inconsistent. The objective of this meta-analysis was to assess the effects on metabolic profiles and safety of chromium supplementation in type 2 diabetes mellitus and cholesterol. Literature searches in PubMed, Scopus and Web of Science were made by use of related terms-keywords and randomized clinical trials during the period of 2000-2014. Thirteen trials fulfilled the inclusion criteria and were included in this systematic review. Total doses of Cr supplementation and brewer's yeast ranged from 42 to 1,000 μg/day, and duration of supplementation ranged from 30 to 120 days. The analysis indicated that there was a significant effect of chromium supplementation in diabetics on fasting plasma glucose with a weighted average effect size of -29.26 mg/dL, p = 0.01, CI 95% = -52.4 to -6.09; and on total cholesterol with a weighted average effect size of -6.7 mg/dL, p = 0.01, CI 95% = -11.88 to -1.53. The available evidence suggests favourable effects of chromium supplementation on glycaemic control in patients with diabetes.

Clinical Quality Performance in U.S. Health Centers

PubMed Central

Shi, Leiyu; Lebrun, Lydie A; Zhu, Jinsheng; Hayashi, Arthur S; Sharma, Ravi; Daly, Charles A; Sripipatana, Alek; Ngo-Metzger, Quyen

2012-01-01

Objective To describe current clinical quality among the nation's community health centers and to examine health center characteristics associated with performance excellence. Data Sources National data from the 2009 Uniform Data System. Data Collection/Extraction Methods Health centers reviewed patient records and reported aggregate data to the Uniform Data System. Study Design Six measures were examined: first-trimester prenatal care, childhood immunization completion, Pap tests, low birth weight, controlled hypertension, and controlled diabetes. The top 25 percent performing centers were compared with lower performing (bottom 75 percent) centers on these measures. Logistic regressions were utilized to assess the impact of patient, provider, and institutional characteristics on health center performance. Principal Findings Clinical care and outcomes among health centers were generally comparable to national averages. For instance, 67 percent of pregnant patients received timely prenatal care (national = 68 percent), 69 percent of children achieved immunization completion (national = 67 percent), and 63 percent of hypertensive patients had blood pressure under control (national = 48 percent). Depending on the measure, centers with more uninsured patients were less likely to do well, while centers with more physicians and enabling service providers were more likely to do well. Conclusions Health centers provide quality care at rates comparable to national averages. Performance may be improved by increasing insurance coverage among patients and increasing the ratios of physicians and enabling service providers to patients. PMID:22594465

Controllable Fabrication of Non-Close-Packed Colloidal Nanoparticle Arrays by Ion Beam Etching

NASA Astrophysics Data System (ADS)

Yang, Jie; Zhang, Mingling; Lan, Xu; Weng, Xiaokang; Shu, Qijiang; Wang, Rongfei; Qiu, Feng; Wang, Chong; Yang, Yu

2018-06-01

Polystyrene (PS) nanoparticle films with non-close-packed arrays were prepared by using ion beam etching technology. The effects of etching time, beam current, and voltage on the size reduction of PS particles were well investigated. A slow etching rate, about 9.2 nm/min, is obtained for the nanospheres with the diameter of 100 nm. The rate does not maintain constant with increasing the etching time. This may result from the thermal energy accumulated gradually in a long-time bombardment of ion beam. The etching rate increases nonlinearly with the increase of beam current, while it increases firstly then reach its saturation with the increase of beam voltage. The diameter of PS nanoparticles can be controlled in the range from 34 to 88 nm. Based on the non-close-packed arrays of PS nanoparticles, the ordered silicon (Si) nanopillars with their average diameter of 54 nm are fabricated by employing metal-assisted chemical etching technique. Our results pave an effective way to fabricate the ordered nanostructures with the size less than 100 nm.

Effects of a parallel resistor on electrical characteristics of a piezoelectric transformer in open-circuit transient state.

PubMed

Chang, Kuo-Tsai

2007-01-01

This paper investigates electrical transient characteristics of a Rosen-type piezoelectric transformer (PT), including maximum voltages, time constants, energy losses and average powers, and their improvements immediately after turning OFF. A parallel resistor connected to both input terminals of the PT is needed to improve the transient characteristics. An equivalent circuit for the PT is first given. Then, an open-circuit voltage, involving a direct current (DC) component and an alternating current (AC) component, and its related energy losses are derived from the equivalent circuit with initial conditions. Moreover, an AC power control system, including a DC-to-AC resonant inverter, a control switch and electronic instruments, is constructed to determine the electrical characteristics of the OFF transient state. Furthermore, the effects of the parallel resistor on the transient characteristics at different parallel resistances are measured. The advantages of adding the parallel resistor also are discussed. From the measured results, the DC time constant is greatly decreased from 9 to 0.04 ms by a 10 k(omega) parallel resistance under open output.

Achieving the broader frequency electromagnetic absorber by development of magnetic core-shell composite with tunable shell/core sizes

NASA Astrophysics Data System (ADS)

Cheng, Ye; Guo, Yuhang; Zhang, Zhenya; Dong, Songtao; Liu, Suwei; Wang, Hongying

2018-03-01

Magnetic absorber has been regarded as the advanced electromagnetic energy transfer material to solve the increasingly high frequency electromagnetic interference issue. Even so, the pure magnetic material, in particular magnetic metal nanoparticle, suffering from the poor chemical stability and strong eddy current effect, thus limits it further application. To overcome this shortage, surrounded the magnetic metal nanoparticle (MPs) with insulated oxide shell has been considered to be an efficient route to suppress such an eddy current effect. Meanwhile, the combined insulated shell with good impedance matching feature, shows a positive role on the electromagnetic energy transfer intensity. In this regard, the binary Fe@α-Fe2O3 composite with the average size of ∼ 20 nm was prepared by a facile self-oxidation reaction. Interestingly, both the core diameter and shell thickness is controllable by controlling the oxide degree. The electromagnetic energy transfer performance revealed the maximum absorption frequency bandwidth of the optimal Fe@α-Fe2O3 composite is up to 5.3 G(8.2-13.5 GHz)under a small coating thickness of 1.5 mm.

40 CFR 63.652 - Emissions averaging provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... emissions average. This must include any Group 1 emission points to which the reference control technology... controls for a Group 1 emission point, the pollution prevention measure alone does not have to reduce... in control after November 15, 1990; (2) Group 1 emission points that are controlled by a reference...

40 CFR 63.652 - Emissions averaging provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... emissions average. This must include any Group 1 emission points to which the reference control technology... controls for a Group 1 emission point, the pollution prevention measure alone does not have to reduce... in control after November 15, 1990; (2) Group 1 emission points that are controlled by a reference...

Average current per vacuum-arc cathode spot and spot velocity in a magnetic field on a CuCr50/50 nanocomposite

NASA Astrophysics Data System (ADS)

Zabello, K. K.; Poluyanova, I. N.; Yakovlev, V. V.; Shkol'nik, S. M.

2017-11-01

It has been shown that such cathode spot characteristics as the average current per spot and its dependence on tangential magnetic-field induction B t and the spot velocity and its dependence on B t for two CuCr50/50 specimens with very different structures (nanocomposite and "solid-state sintered" composite) almost coincide if the surface of contacts has been totally remelted before measurements with the use of moderate arc currents in the process of conditioning.

Seasonal and Interannual Variation of Currents and Water Properties off the Mid-East Coast of Korea

NASA Astrophysics Data System (ADS)

Park, J. H.; Chang, K. I.; Nam, S.

2016-02-01

Since 1999, physical parameters such as current, temperature, and salinity off the mid-east coast of Korea have been continuously observed from the long-term buoy station called `East-Sea Real-time Ocean monitoring Buoy (ESROB)'. Applying harmonic analysis to 6-year-long (2007-2012) depth-averaged current data from the ESROB, a mean seasonal cycle of alongshore currents, characterized by poleward current in average and equatorward current in summer, is extracted which accounts for 5.8% of the variance of 40 hours low-pass filtered currents. In spite of the small variance explained, a robust seasonality of summertime equatorward reversal typifies the low-passed alongshore currents along with low-density water. To reveal the dynamics underlying the seasonal variation, each term of linearized, depth-averaged momentum equations is estimated using the data from ESROB, adjacent tide gauge stations, and serial hydrographic stations. The result indicates that the reversal of alongshore pressure gradient is a major driver of the equatorward reversals in summer. The reanalysis wind product (MERRA) and satellite altimeter-derived sea surface height (AVISO) data show correlated features between positive (negative) wind stress curl and sea surface depression (uplift). Quantitative estimates reveal that the wind-stress curl accounts for 42% of alongshore sea level variation. Summertime low-density water originating from the northern coastal region is a footprint of the buoyancy-driven equatorward current. An interannual variation (anomalies from the mean seasonal cycle) of alongshore currents and its possible driving mechanisms will be discussed.

Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

NASA Astrophysics Data System (ADS)

Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

2018-07-01

In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 {μ Φ }_0/Hz^{1/2}.

Voltage oriented control of self-excited induction generator for wind energy system with MPPT

NASA Astrophysics Data System (ADS)

Amieur, Toufik; Taibi, Djamel; Amieur, Oualid

2018-05-01

This paper presents the study and simulation of the self-excited induction generator in the wind power production in isolated sites. With this intention, a model of the wind turbine was established. Extremum-seeking control algorithm method by using Maximum Power Point Tracking (MPPT) is proposed control solution aims at driving the average position of the operating point near to optimality. The reference of turbine rotor speed is adjusted such that the turbine operates around maximum power for the current wind speed value. After a brief review of the concepts of converting wind energy into electrical energy. The proposed modeling tools were developed to study the performance of standalone induction generators connected to capacitor bank. The purpose of this technique is to maintain a constant voltage at the output of the rectifier whatever the loads and speeds. The system studied in this work is developed and tested in MATLAB/Simulink environment. Simulation results validate the performance and effectiveness of the proposed control methods.

Effects of electromagnetic radiation on the hemorheology of rats

NASA Astrophysics Data System (ADS)

Huang, Zhiwei; Tian, Tian; Xiao, Bo; Li, Wen

2017-01-01

The current work examines the effects of electromagnetic radiation on the hemorheology to provide an experimental basis for radiation protection. Electromagnetic radiation was generated by a Helmholtz coil constructed from copper wire. There were six rats altogether: three rats in the experimental group, and three rats in the control group. The rats in the experimental group were continuously exposed to radiation for 10 hours every day, and rats in the control group remained in a normal environment. After 30 days, the characteristics of hemorheology of the two groups were compared. The average plasma viscosity, whole blood high shear velocity, and whole blood low shear viscosity were lower in rats in the experimental group than in rats in the control group, while the whole blood shear viscosity was higher in the experimental group than in the control group. Results suggest that long term exposure to electromagnetic radiation does have certain impacts on the cardiovascular system, deeming it necessary to take preventative measures.

Research on Intelligent Control System of DC SQUID Magnetometer Parameters for Multi-channel System

NASA Astrophysics Data System (ADS)

Chen, Hua; Yang, Kang; Lu, Li; Kong, Xiangyan; Wang, Hai; Wu, Jun; Wang, Yongliang

2018-03-01

In a multi-channel SQUID measurement system, adjusting device parameters to optimal condition for all channels is time-consuming. In this paper, an intelligent control system is presented to determine the optimal working point of devices which is automatic and more efficient comparing to the manual one. An optimal working point searching algorithm is introduced as the core component of the control system. In this algorithm, the bias voltage V_bias is step scanned to obtain the maximal value of the peak-to-peak current value I_pp of the SQUID magnetometer modulation curve. We choose this point as the optimal one. Using the above control system, more than 30 weakly damped SQUID magnetometers with area of 5 × 5 mm^2 or 10 × 10 mm^2 are adjusted and a 36-channel magnetocardiography system perfectly worked in a magnetically shielded room. The average white flux noise is 15 μΦ_0/Hz^{1/2}.

[Epidemic situation and prevention and control strategy of clonorchiasis in Guangdong Province, China].

PubMed

Zhuo-Hui, Deng; Yue-Yi, Fang

2016-05-24

Clonorchiasis is one of the food-borne parasitic diseases. Adult parasites live in the human liver and gallbladder tube system, causing serious complications, such as gallstones, cholecystitis and cholangitis, and even bile duct cancer. The disease is very popular in our country, and the population infection rate is high. It is an important public health problem. Guangdong Province is the earliest province being found of clonorchiasis and with serious epidemic. In the second national human parasitic diseases distribution survey, the results showed that the average infection rate of Clonorchis sinensis in the epidemic areas in Guangdong was 16.42%. It is estimated that the population of C. sinensis infection is over 6 million. The prevention and control of clonorchiasis in China is still in the initial stage currently and we face many challenges such as unclear epidemic characteristics and transmission mode, and lack of long-term prevention and control mechanism. This article introduces the epidemic situation of clonorchiasis and prevention and control strategies and measures in Guangdong.

Why is there net surface heating over the Antarctic Circumpolar Current?

NASA Astrophysics Data System (ADS)

Czaja, Arnaud; Marshall, John

2015-05-01

Using a combination of atmospheric reanalysis data, climate model outputs and a simple model, key mechanisms controlling net surface heating over the Southern Ocean are identified. All data sources used suggest that, in a streamline-averaged view, net surface heating over the Antarctic Circumpolar Current (ACC) is a result of net accumulation of solar radiation rather than a result of heat gain through turbulent fluxes (the latter systematically cool the upper ocean). It is proposed that the fraction of this net radiative heat gain realized as net ACC heating is set by two factors. First, the sea surface temperature at the southern edge of the ACC. Second, the relative strength of the negative heatflux feedbacks associated with evaporation at the sea surface and advection of heat by the residual flow in the oceanic mixed layer. A large advective feedback and a weak evaporative feedback maximize net ACC heating. It is shown that the present Southern Ocean and its circumpolar current are in this heating regime.

Automatic detection of health changes using statistical process control techniques on measured transfer times of elderly.

PubMed

Baldewijns, Greet; Luca, Stijn; Nagels, William; Vanrumste, Bart; Croonenborghs, Tom

2015-01-01

It has been shown that gait speed and transfer times are good measures of functional ability in elderly. However, data currently acquired by systems that measure either gait speed or transfer times in the homes of elderly people require manual reviewing by healthcare workers. This reviewing process is time-consuming. To alleviate this burden, this paper proposes the use of statistical process control methods to automatically detect both positive and negative changes in transfer times. Three SPC techniques: tabular CUSUM, standardized CUSUM and EWMA, known for their ability to detect small shifts in the data, are evaluated on simulated transfer times. This analysis shows that EWMA is the best-suited method with a detection accuracy of 82% and an average detection time of 9.64 days.

Systolic [Ca2+]i regulates diastolic levels in rat ventricular myocytes

PubMed Central

Sankaranarayanan, Rajiv; Kistamás, Kornél; Greensmith, David J.; Venetucci, Luigi A.

2017-01-01

Key points For the heart to function as a pump, intracellular calcium concentration ([Ca2+]i) must increase during systole to activate contraction and then fall, during diastole, to allow the myofilaments to relax and the heart to refill with blood.The present study investigates the control of diastolic [Ca2+]i in rat ventricular myocytes.We show that diastolic [Ca2+]i is increased by manoeuvres that decrease sarcoplasmic reticulum function. This is accompanied by a decrease of systolic [Ca2+]i such that the time‐averaged [Ca2+]i remains constant.We report that diastolic [Ca2+]i is controlled by the balance between Ca2+ entry and Ca2+ efflux during systole.The results of the present study identify a novel mechanism by which changes of the amplitude of the systolic Ca transient control diastolic [Ca2+]i. Abstract The intracellular Ca concentration ([Ca2+]i) must be sufficently low in diastole so that the ventricle is relaxed and can refill with blood. Interference with this will impair relaxation. The factors responsible for regulation of diastolic [Ca2+]i, in particular the relative roles of the sarcoplasmic reticulum (SR) and surface membrane, are unclear. We investigated the effects on diastolic [Ca2+]i that result from the changes of Ca cycling known to occur in heart failure. Experiments were performed using Fluo‐3 in voltage clamped rat ventricular myocytes. Increasing stimulation frequency increased diastolic [Ca2+]i. This increase of [Ca2+]i was larger when SR function was impaired either by making the ryanodine receptor leaky (with caffeine or ryanodine) or by decreasing sarco/endoplasmic reticulum Ca‐ATPase activity with thapsigargin. The increase of diastolic [Ca2+]i produced by interfering with the SR was accompanied by a decrease of the amplitude of the systolic Ca transient, such that there was no change of time‐averaged [Ca2+]i. Time‐averaged [Ca2+]i was increased by β‐adrenergic stimulation with isoprenaline and increased in a saturating manner with increased stimulation frequency; average [Ca2+]i was a linear function of Ca entry per unit time. Diastolic and time‐averaged [Ca2+]i were decreased by decreasing the L‐type Ca current (with 50 μm cadmium chloride). We conclude that diastolic [Ca2+]i is controlled by the balance between Ca entry and efflux during systole. Furthermore, manoeuvres that decrease the amplitude of the Ca transient (without decreasing Ca influx) will therefore increase diastolic [Ca2+]i. This identifies a novel mechanism by which changes of the amplitude of the systolic Ca transient control diastolic [Ca2+]i. PMID:28617952

Modulation of thyroid hormone receptors by non-thyroidal stimuli

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

ErkenBrack, D.E.; Clemons, G.K.

1988-01-01

The ability of non-thyroidal stimuli to affect the binding affinity and capacity of solubilized nuclear receptors for thyroid hormones was studied in a normal homeostatic system (erythropoiesis) and a pathobiologic one (lung-ozone interaction). No significant effects on affinity were found, as Kd control values for receptors derived from rat bone marrow averaged 57 (+/- 28) pM while experimental (hypoxic) values averaged 89 (+/- 55) pM. Kd control values in rat lung were found to average 142 (+/- 22) pM while average values derived from experimental protocols with ozone and methimazole were 267 (+/- 44) pM and 161 (+/- 35) pMmore » respectively. Finally, Kd control values for receptors derived from cultured MEL cells averaged 19 (+/- 2.6) pM while experimental values during exposure to DMSO or IGF1 were 23 (+/- 3.6) pM and 26 (+/- 11) pM respectively. In contrast, binding capacity (expressed as fmoles of hormone bound per unit protein of solubilized receptor) was markedly perturbed in several tissues by various agents: ozone effects on lung were shown by an average control value of 3.3 (+/- 0.4) as opposed to an experimental average of 28 (+/- 1.9); and hypoxia effects on erythroid tissue were displayed by an average control value of 0.7 (+/- 0.07) as opposed to the experimental figure of 1.8 (+/- 0.03). In cultured MEL cells, binding capacity was seen to be increased from control values of 388 (+/- 15) sites/cell to 1243 (+/- 142) sites/cell after DMSO exposure and 2002 (+/- 10) sites/cell after IGF1 exposure. Parallel experiments done with receptors derived from rat liver yielded values similar to those reported by other investigators and were unaffected by the experimental agents.« less

Analysis of Ideal Towers for Tall Wind Applications

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

Dykes, Katherine L; Damiani, Rick R; Roberts, Joseph O

Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hubmore » heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.« less

Analysis of Ideal Towers for Tall Wind Applications: Preprint

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

Dykes, Katherine L; Damiani, Rick R; Roberts, Joseph O

Innovation in wind turbine tower design is of significant interest for future development of wind power plants. First, wind turbine towers account for a large portion of overall capital expenditures for wind power projects. Second, for low wind-resource regions of the world, the use of low-cost tall-tower technology has the potential to open new markets for development. This study investigates the relative potential of various tower configurations in terms of mass and cost. For different market applications and hub heights, idealized tall towers are designed and compared. The results show that innovation in wind turbine controls makes reaching higher hubmore » heights with current technology economically viable. At the same time, new technologies hold promise for reducing tower costs as these technologies mature and hub heights reach twice the current average.« less

Stationary multifaceted asymmetric radiation from the edge and improved confinement mode in a superconducting tokamak.

PubMed

Gao, X; Xie, J K; Wan, Y X; Ushigusa, K; Wan, B N; Zhang, S Y; Li, J; Kuang, G L

2002-01-01

Stationary multifaceted asymmetric radiation from the edge (MARFE) is studied by gas-puffing feedback control according to an empirical MARFE critical density ( approximately 1.8 x 10(13) cm(-3)) in the HT-7 Ohmic discharges (where the plasma current I(p) is about 170 kA, loop voltage V(loop)=2-3 V, toroidal field B(T)=1.9 T, and Z(eff)=3-4). It is observed that an improved confinement mode characterized by D(alpha) line emissions drops and the line-averaged density increase is triggered in the stationary MARFE discharges. The mode is not a symmetric "detachment" state, because the quasi-steady-state poloidally asymmetric radiation (e.g., C III line emissions) still exists. This phenomenon has not been predicted by the current MARFE theory.

A Microgenetic Analysis of Strategic Variability in Gifted and Average-Ability Children

ERIC Educational Resources Information Center

Steiner, Hillary Hettinger

2006-01-01

Many researchers have described cognitive differences between gifted and average-performing children. Regarding strategy use, the gifted advantage is often associated with differences such as greater knowledge of strategies, quicker problem solving, and the ability to use strategies more appropriately. The current study used microgenetic methods…

Macroscopic neural mass model constructed from a current-based network model of spiking neurons.

PubMed

Umehara, Hiroaki; Okada, Masato; Teramae, Jun-Nosuke; Naruse, Yasushi

2017-02-01

Neural mass models (NMMs) are efficient frameworks for describing macroscopic cortical dynamics including electroencephalogram and magnetoencephalogram signals. Originally, these models were formulated on an empirical basis of synaptic dynamics with relatively long time constants. By clarifying the relations between NMMs and the dynamics of microscopic structures such as neurons and synapses, we can better understand cortical and neural mechanisms from a multi-scale perspective. In a previous study, the NMMs were analytically derived by averaging the equations of synaptic dynamics over the neurons in the population and further averaging the equations of the membrane-potential dynamics. However, the averaging of synaptic current assumes that the neuron membrane potentials are nearly time invariant and that they remain at sub-threshold levels to retain the conductance-based model. This approximation limits the NMM to the non-firing state. In the present study, we newly propose a derivation of a NMM by alternatively approximating the synaptic current which is assumed to be independent of the membrane potential, thus adopting a current-based model. Our proposed model releases the constraint of the nearly constant membrane potential. We confirm that the obtained model is reducible to the previous model in the non-firing situation and that it reproduces the temporal mean values and relative power spectrum densities of the average membrane potentials for the spiking neurons. It is further ensured that the existing NMM properly models the averaged dynamics over individual neurons even if they are spiking in the populations.

Establishment of a rice-duck integrated farming system and its effects on soil fertility and rice disease control

NASA Astrophysics Data System (ADS)

Teng, Qing; Hu, Xue-Feng; Cheng, Chang; Luo, Zhi-Qing; Luo, Fan

2015-04-01

Rice-duck integrated farming is an ecological farming system newly established in some areas of southern China . It was reported that the ducks walking around the paddy fields is beneficial to control weed hazards and reduce rice pests and diseases. To study and evaluate the effects of the rice-duck integrated farming on soil fertility and rice disease control, a field experiment of rice cultivation was carried out in the suburb of Shanghai in 2014. It includes a treatment of raising ducks in the fields and a control without ducks. The treatment was implemented by building a duck coop nearby the experimental fields and driving 15 ducks into a plot at daytime since the early stage of rice growth. Each plot is 667 m2 in area. The treatment and control were replicated for three times. No any herbicides, pesticides, fungicides and chemical fertilizers were applied during the experiment to prevent any disturbance to duck growing and rice weed hazards and disease incidences from agrochemicals. The results are as follows: (1) The incidences of rice leaf rollers (Cnaphalocrocis medinalis) and stem borers treated with ducks, 0.45%and 1.18% on average, respectively, are lower than those of the control, 0.74% and 1.44% on average, respectively. At the late stage of rice growth, the incidence of rice sheath blight treated with ducks, 13.15% on average, is significantly lower than that of the control, 16.9% on average; and the incidence of rice planthoppers treated with ducks, 11.3 per hill on average, is also significantly lower than that of the control, 47.4 per hill on average. (2) The number of weeds in the plots treated with ducks, 8.3 per m2 on average, is significantly lower than that of the control, 87.5 m2 on average. (3) Raising ducks in the fields could also enhance soil enzyme activity and nutrient status. At the late stage of rice growth, the activities of urease, phosphatase, sucrase and catalase in the soils treated with ducks are 1.39 times, 1.40 times, 1.29 times and 1.13 times those of the control, respectively; and the content of available P and alkali-hydrolyzable N in the soils treated with ducks, 23.35 mg kg-1 and 107.33 mg kg-1, on average, respectively, are significantly higher than those of the control, 15.70 mg kg-1 and 84.00 mg kg-1 on average, respectively. (4) The grain yield of the plots treated with ducks, 6456.25 kg hm-2 on average, is significantly higher than that of the control, 3403.81 kg hm-2. In short, raising ducks in the paddy fields not only shows a potential of controlling weed hazards and reducing rice pests and diseases, but also effectively improves soil fertility and rice grain yield. Such rice-duck integrated farming will highly contribute to establishing an organic or low-input farming system in southern China in the future.

Hydrogeology and groundwater availability in Clarke County, Virginia

USGS Publications Warehouse

Nelms, David L.; Moberg, Roger M.

2010-01-01

The prolonged drought between 1999 and 2002 drew attention in Clarke County, Virginia, to the quantity and sustainability of its groundwater resources. The groundwater flow systems of the county are complex and are controlled by the extremely folded and faulted geology that underlies the county. A study was conducted between October 2002 and October 2008 by the U.S. Geological Survey, in cooperation with Clarke County, Virginia, to describe the hydrogeology and groundwater availability in the county and to establish a long-term water monitoring network. The study area encompasses approximately 177 square miles and includes the carbonate and siliciclastic rocks of the Great Valley section of the Valley and Ridge Physiographic Province and the metamorphic rocks of the Blue Ridge Physiographic Province (Blue Ridge). High-yielding wells generally tend to cluster along faults, within lineament zones, and in areas of tight folding throughout the county. Water-bearing zones are generally within 250 feet (ft) of land surface; however, median depths are slightly deeper for the hydrogeologic units of the Blue Ridge than for those of the Great Valley section of the county. Total water-level fluctuations between October 2002 and October 2008 ranged from 2.86 to 87.84 ft across the study area, with an average of 24.15 ft. Generally, water-level fluctuations were greatest near hydrologic divides, in isolated elevated areas, and in the Opequon Creek Basin. Seasonally, water-level highs occur in the early spring at the end of the major groundwater recharge period and lows occur in late autumn when evapotranspiration rates begin to decrease. An overall downward trend in water levels between 2003 and 2008, which closely follows a downward trend in annual precipitation over the same period, was observed in a majority of wells in the Great Valley and in some of the wells in the Blue Ridge. Water-level fluctuations in the Blue Ridge tend to follow current meteorological conditions, and seasonal highs and lows tend to shift in response to the current conditions. Springs generally are present along faults and fold axes, and discharges for the study period ranged from dry to 10 cubic feet per second. A similar downward trend in discharges correlates with the trend in water levels and is indicative of an aquifer system that, over time, drains to a base level controlled by springs and streams. Point discharge from springs can occur as the start of flows of streams and creeks, along banks, and as discrete discharge through streambeds in the Great Valley. For the most part, streams, creeks, and rivers in the Great Valley function as aqueducts. Springs in the Blue Ridge have relatively low discharge rates, have small drainage areas, and are susceptible to current meteorological conditions. Estimates of effective groundwater recharge from 2001 to 2007 ranged from 6.4 to 23.0 inches per year (in/yr) in the Dry Marsh Run and Spout Run Basins with averages of 11.6 and 11.9 in/yr, respectively. Base flow accounted for between 80 and 97 percent of mean streamflow and averaged about 90 percent in these basins. The high base-flow index values (percent of streamflow from base flow) in the Dry Marsh Run and Spout Run Basins indicate that groundwater is the dominant source of streamflow during both wet and drought conditions. Between 46 and 82 percent of the precipitation that fell on the Dry Marsh Run and Spout Run Basins from 2001 to 2007 was removed by evapotranspiration, and an average of approximately 30 percent of the precipitation reached the water table as effective recharge. The high permeability of the rocks and low relief in these basins are not conducive for runoff; therefore, on average, only about 3 to 4 percent of the precipitation becomes runoff. Groundwater flow systems in the county are extremely vulnerable to current climatic conditions. Successive years of below-average effective recharge cause declines in water levels, spring discha

Hexavalent chromium exposures during full-aircraft corrosion control.

PubMed

Carlton, Gary N

2003-01-01

Aluminum alloys used in the construction of modern aircraft are subject to corrosion. The principal means of controlling this corrosion in the U.S. Air Force are organic coatings. The organic coating system consists of a chromate conversion coat, epoxy resin primer, and polyurethane enamel topcoat. Hexavalent chromium (CrVI) is present in the conversion coat in the form of chromic acid and in the primer in the form of strontium chromate. CrVI inhalation exposures can occur when workers spray conversion coat onto bare metal and apply primer to the treated metal surface. In addition, mechanical abrasion of aircraft surfaces can generate particulates that contain chromates from previously applied primers and conversion coats. This study measured CrVI exposures during these corrosion control procedures. Mean time-weighted average (TWA) exposure to chromic acid during conversion coat treatment was 0.48 microg/m(3), below the current American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV(R)) TWA of 50 microg/m(3) for water-soluble CrVI compounds. Mean TWA exposures to strontium chromate were 5.33 microg/m(3) during mechanical abrasion and 83.8 microg/m(3) during primer application. These levels are in excess of the current ACGIH TLV-TWA of 0.5 microg/m(3) for strontium chromate. In the absence of a change from chromated to nonchromated conversion coats and primers, additional control measures are needed to reduce these exposures.

Force production and time-averaged flow structure around thin, non-slender delta wings

NASA Astrophysics Data System (ADS)

Tu, Han; Green, Melissa

2017-11-01

Experimental force measurement and time-averaged three dimensional flow visualization of low Reynolds number baseline cases have been carried out on a steady flat plate delta wing. Current data will serve as steady reference for future unsteady flow and actuation cases. The comprehensive study will compare force production in highly unsteady environments, which is necessary to consider in unmanned combat aerial vehicle (UCAV) control strategies. Force measurements are carried out at angles of attack 10, 15, 20, 25 and 30 degrees. The coefficient of drag increases with angle of attack, while the coefficient of lift reaches a maximum value at 20 degrees. Time-averaged flow visualization conducted at angles of attack of 20, 25 and 30 degrees shows vortices with larger magnitude that persist farther into wake are generated at higher angles of attack. These results compare analogously with similar steady baseline experiment results of high Reynolds number conducted by collaborators. This work was supported by the Office of Naval Research under ONR Award No. N00014-16-1-2732. We also acknowledge the collaborative support of Dr. David Rival and Mr. Matthew Marzanek at Queen's University.

Cation distribution and vacancies in nickel cobaltite.

PubMed

Loche, Danilo; Marras, Claudia; Carta, Daniela; Casula, Maria Francesca; Mountjoy, Gavin; Corrias, Anna

2017-06-28

Samples of nickel cobaltite, a mixed oxide occurring in the spinel structure which is currently extensively investigated because of its prospective application as ferromagnetic, electrocatalytic, and cost-effective energy storage material were prepared in the form of nanocrystals stabilized in a highly porous silica aerogel and as unsupported nanoparticles. Nickel cobaltite nanocrystals with average size 4 nm are successfully grown for the first time into the silica aerogel provided that a controlled oxidation of the metal precursor phases is carried out, consisting in a reduction under H 2 flow followed by mild oxidation in air. The investigation of the average oxidation state of the cations and of their distribution between the sites within the spinel structure, which is commonly described assuming the Ni cations are only located in the octahedral sites, has been carried out by X-ray absorption spectroscopy providing evidence for the first time that the unsupported nickel cobaltite sample has a Ni : Co molar ratio higher than the nominal ratio of 1 : 2 and a larger than expected average overall oxidation state of the cobalt and nickel cations. This is achieved retaining the spinel structure, which accommodates vacancies to counterbalance the variation in oxidation state.

Statistical average estimates of high latitude field-aligned currents from the STARE and SABRE coherent VHF radar systems

NASA Astrophysics Data System (ADS)

Kosch, M. J.; Nielsen, E.

Two bistatic VHF radar systems, STARE and SABRE, have been employed to estimate ionospheric electric fields in the geomagnetic latitude range 61.1 - 69.3° (geographic latitude range 63.8 - 72.6°) over northern Scandinavia. 173 days of good backscatter from all four radars have been analysed during the period 1982 to 1986, from which the average ionospheric divergence electric field versus latitude and time is calculated. The average magnetic field-aligned currents are computed using an AE-dependent empirical model of the ionospheric conductance. Statistical Birkeland current estimates are presented for high and low values of the Kp and AE indices as well as positive and negative orientations of the IMF B z component. The results compare very favourably to other ground-based and satellite measurements.

Lead Toxicity Risks in Gunshot Victims

PubMed Central

de Araújo, Gabriel Costa Serrão; Mourão, Natália Teixeira; Pinheiro, Igor Natário; Xavier, Analúcia Rampazzo; Gameiro, Vinicius Schott

2015-01-01

Background Gunshot wounds require surgeons to decide whether to remove or leave bullet fragments in the body. Surgeons also decide how to follow up with patients who have lead fragments retained in their body. Current literature recommends to remove only intra-articular fragments without the need for a follow-up for patients with the metal retained. Therefore, this study investigates chronic lead toxicity for gunshot wounds. Methods The study was performed in the metropolitan area of Rio de Janeiro/Brazil, between 2013 and 2015. It was a case-control study that included 45 victims of gunshot lesions with metallic fragments retained for more than 6 months. The 45 controls were matched for gender, age, and race. We compared the lead blood levels and frequency of symptoms. Results The control group had average blood lead levels of 2.17 μg/dL (95% Confidence Interval [CI]; 1.71–2.63) and median 2.1 μg/dL. The case group had average values of 9.01 μg/dL (CI; 6.07–11.96) and median values of 6.5 μg/dL with p-values < = 0.001. The case group reported the following more frequently: irritancy, bad mood, headache, memory losses, daylight drowsiness, myalgia, weakness, abdominal pain, joint pain, trembling, tingling limbs. There was statistical significance for the differences of symptoms frequencies and for odds ratio between groups. Conclusions Although the mean lead levels found were lower than the current laboratory references, low levels have been associated with both rising morbidity and mortality. The WHO stated: “There is no known level of lead exposure that is considered safe”. In conclusion, this work showed that bullets retained in the body are not innocuous. There are impacts in the blood lead levels and symptoms related to it, even with few fragments, extra-articular located or existing with low blood lead levels. PMID:26509498

The Association between Specific Substances of Abuse and Subcortical Intracerebral Hemorrhage Versus Ischemic Lacunar Infarction.

PubMed

Kaplan, Emma H; Gottesman, Rebecca F; Llinas, Rafael H; Marsh, Elisabeth B

2014-01-01

Hypertension damages small vessels, resulting in both lacunar infarction and subcortical intracerebral hemorrhage (ICH). Substance abuse has also been linked to small vessel pathology. This study explores whether the use of specific substances (e.g., cocaine, tobacco) is associated with subcortical ICH over ischemia in hypertensive individuals. Patients with hypertension, admitted with lacunar infarcts (measuring <2.0 cm) or subcortical ICH, were included in analysis. Brain MRIs and head CTs were retrospectively reviewed along with medical records. Demographic information and history of substance use (illicit/controlled: cocaine, heroin, marijuana, benzodiazepines, and methadone; alcohol; and tobacco) was obtained. "Current use" and "history of use" were determined from patient history or a positive toxicology screen. "Heavy use" was defined as: smoking- ≥0.5 packs per day or 10 pack-years; alcohol- average of >1 drink per day (women), >2 drinks per day (men). Logistic regression was performed with ICH as the dependent variable comparing those presenting with ICH to those presenting with ischemia. Of the 580 patients included in analysis, 217 (37%) presented with ICH. The average age was similar between the two groups (64.7 versus 66.3 years). Illicit/controlled drug use was associated with a significantly increased risk of ICH over stroke in unadjusted models (25 versus 15%, p = 0.02), with the largest effect seen in users ≥65 years old (not statistically significant). Smoking was associated with ischemia over ICH in a dose-dependent manner: any history of smoking OR 1.84, CI 1.19-2.84; current use OR 2.23, CI 1.37-3.62; heavy use OR 2.48, CI 1.50-4.13. Alcohol use was not preferentially associated with either outcome (p = 0.29). In hypertensive patients, tobacco use is associated with an increased risk of subcortical ischemia compared to ICH, while use of illicit/controlled substances appears to be predictive of hemorrhage.

Overview of recent experimental results from the Aditya tokamak

NASA Astrophysics Data System (ADS)

Tanna, R. L.; Ghosh, J.; Chattopadhyay, P. K.; Raj, Harshita; Patel, Sharvil; Dhyani, P.; Gupta, C. N.; Jadeja, K. A.; Patel, K. M.; Bhatt, S. B.; Panchal, V. K.; Patel, N. C.; Chavda, Chhaya; Praveenlal, E. V.; Shah, K. S.; Makawana, M. N.; Jha, S. K.; Gopalkrishana, M. V.; Tahiliani, K.; Sangwan, Deepak; Raju, D.; Nagora, Umesh; Pathak, S. K.; Atrey, P. K.; Purohit, S.; Raval, J.; Joisa, Y. S.; Rao, C. V. S.; Chowdhuri, M. B.; Banerjee, S.; Ramaiya, N.; Manchanda, R.; Thomas, J.; Kumar, Ajai; Ajay, Kumar; Sharma, P. K.; Kulkarni, S. V.; Sathyanarayana, K.; Shukla, B. K.; Das, Amita; Jha, R.; Saxena, Y. C.; Sen, A.; Kaw, P. K.; Bora, D.; the ADITYA Team

2017-10-01

Several experiments, related to controlled thermonuclear fusion research and highly relevant for large size tokamaks, including ITER, have been carried out in ADITYA, an ohmically heated circular limiter tokamak. Repeatable plasma discharges of a maximum plasma current of ~160 kA and discharge duration beyond ~250 ms with a plasma current flattop duration of ~140 ms have been obtained for the first time in ADITYA. The reproducibility of the discharge reproducibility has been improved considerably with lithium wall conditioning, and improved plasma discharges are obtained by precisely controlling the position of the plasma. In these discharges, chord-averaged electron density ~3.0-4.0  ×  1019 m-3 using multiple hydrogen gas puffs, with a temperature of the order of ~500-700 eV, have been achieved. Novel experiments related to disruption control are carried out and disruptions, induced by hydrogen gas puffing, are successfully mitigated using the biased electrode and ion cyclotron resonance pulse techniques. Runaway electrons are successfully mitigated by applying a short local vertical field (LVF) pulse. A thorough disruption database has been generated by identifying the different categories of disruption. Detailed analysis of several hundred disrupted discharges showed that the current quench time is inversely proportional to the q edge. Apart from this, for volt-sec recovery during the plasma formation phase, low loop voltage start-up and current ramp-up experiments have been carried out using electron cyclotron resonance heating (ECRH). Successful recovery of volt-sec leads to the achievement of longer plasma discharge durations. In addition, the neon gas puff assisted radiative improved confinement mode has also been achieved in ADITYA. All of the above mentioned experiments will be discussed in this paper.

Health and safety—the downward trend in lead levels

NASA Astrophysics Data System (ADS)

Mayer, M. G.; Wilson, D. N.

Lead has been known and used by man for thousands of years and its toxic properties have been known for almost as long. In consequence, a wide body of legislation has built up and is designed to protect individuals in both the occupational and the general environments. At the occupational level, two types of controls are widely employed, namely, lead-in-air and lead-in-blood. Limits placed on the amount of lead-in-air are designed to ensure that individuals are not exposed to unsafe levels of lead via inhalation. Currently, the most common standard is 0.15 mg m -3 but there is a clear downward trend and levels as low as 0.05 mg m -3 are mandatory in some countries. Controls on the amount of lead-in-blood give a more direct indication of the exposure experienced by individuals. The most common level presently employed is 70 μg m -3 but, as knowledge of the health effects of lead improves, lower levels are being introduced and 50 μg m -3 is now fairly common. While women are no more sensitive to lead than men, some countries do employ lower blood-lead limits for women in the workplace in order to protect any developing foetus. This paper examines the levels currently in force in various countries and describes developments which are now taking place in the legislation that is being enacted in several parts of the world. As far as the general public is concerned, only a relatively small number of countries employ controls. Where controls do exist, however, they are set at much lower levels than for the occupational environment in order to protect the most sensitive members of the population. Several countries employ limits on lead in ambient air. Traditionally, these have been set at either 1.5 or 2.0 μg m -3, but several countries are currently considering sharp downward revisions to levels of the order of 0.5 μg m -3. A few countries offer guidance on acceptable blood levels for the general population, most commonly for children. Again downward revisions are taking place but where data are available, there is a very encouraging downward trend also in average blood-lead levels found amongst members of the population. These must be due to a combination of factors which have reduced exposures to lead. The net result is that, at least in the more industrialized countries, average blood-lead levels have fallen to extremely low levels and very few individuals can be found with blood lead levels above currently accepted levels of concern.

The challenge of non-invasive cognitive physiology of the human brain: how to negotiate the irrelevant background noise without spoiling the recorded data through electronic averaging.

PubMed

Tomberg, C; Desmedt, J E

1999-07-29

Brain mechanisms involved in selective attention in humans can be studied by measures of regional blood flow and metabolism (by positron emission tomography) which help identify the various locations with enhanced activities over a period of time of seconds. The physiological measures provided by scalp-recorded brain electrical potentials have a better resolution (milliseconds) and can reveal the actual sequences of distinct neural events and their precise timing. We studied selective attention to sensory inputs from fingers because the brain somatic representations are deployed over the brain convexity under the scalp thereby making it possible to assess distinct stages of cortical processing and representation through their characteristic scalp topographies. In the electrical response to a finger input attended by the subject, the well-known P300 manifests a widespread inhibitory mechanism which is released after a target stimulus has been identified. P300 is preceded by distinct cognitive electrogeneses such as P40, P100 and N140 which can be differentiated from the control (obligatory) profile by superimposition or electronic subtraction. The first cortical response N20 is stable across conditions, suggesting that the first afferent thalamocortical volley is not affected by selective attention. At the next stage of modality-specific cortex in which the sensory features are processed and represented, responses were enhanced (cognitive P40) only a very few milliseconds after arrival of the afferent volley at the cortex, thus documenting a remarkable precocity of attention gain control in the somatic modality. The physiology of selective attention also provides useful cues in relation to non-target inputs which the subject must differentiate in order to perform the task. When having to tell fingers apart, the brain strategy for non-target fingers is not to inhibit or filter them out, but rather to submit their input to several processing operations that are actually enhanced when the discrimination from targets becomes more difficult. While resolving a number of such issues, averaged data cannot disclose the flexibility of brain mechanisms nor the detailed features of cognitive electrogeneses because response variations along time have been ironed out by the bulk treatment. We attempted to address the remarkable versatility of humans in dealing with their sensory environment under ecological conditions by studying single non-averaged responses. We identified distinct cognitive P40, P100, N140 and P300 electrogeneses in spite of the noise by numerically assessing their characteristic scalp topography signatures. Single-trial data suggest reconsiderations of current psychophysiological issues. The study of non-averaged responses can clarify issues raised by averaging studies as illustrated by our recent study of cognitive brain potentials for finger stimuli which remain outside the subject's awareness. This has to do with the physiological basis of the 'cognitive unconscious', that is, current mental processes lying on the fringe or outside of phenomenal awareness and voluntary control, but which can influence ongoing behaviour. Averaged data suggest that, in selective auditory attention, the subject may not notice mild concomitant finger inputs. The study of non-averaged responses documents the optional and independent occurrence of the cognitive P40, P100 and N140 (but not P300) electrogeneses while the finger inputs remain outside phenomenal awareness. These results suggest that the subject unconsciously assigns limited cognitive resources to distinct somatic cortical areas thereby submitting finger inputs to an intermittent curtailed surveillance which can remain on the fringe or outside consciousness. The study of cognitive electrogeneses in single non-averaged responses is making possible a neurophysiology of cognition in real time.

Global characteristics of auroral Hall currents derived from the Swarm constellation: dependences on season and IMF orientation

NASA Astrophysics Data System (ADS)

Huang, Tao; Lühr, Hermann; Wang, Hui

2017-11-01

On the basis of field-aligned currents (FACs) and Hall currents derived from high-resolution magnetic field data of the Swarm constellation, the average characteristics of these two current systems in the auroral regions are comprehensively investigated by statistical methods. This is the first study considering both current types determined simultaneously by the same spacecraft in both hemispheres. The FAC distribution, derived from the novel Swarm dual-spacecraft approach, reveals the well-known features of Region 1 (R1) and Region 2 (R2) FACs. At high latitudes, Region 0 (R0) FACs appear on the dayside. Their flow direction, up or down, depends on the orientation of the interplanetary magnetic field (IMF) By component. Of particular interest is the distribution of auroral Hall currents. The prominent auroral electrojets are found to be closely controlled by the solar wind input, but we find no dependence of their intensity on the IMF By orientation. The eastward electrojet is about 1.5 times stronger in local summer than in winter. Conversely, the westward electrojet shows less dependence on season. As to higher latitudes, part of the electrojet current is closed over the polar cap. Here the seasonal variation of conductivity mainly controls the current density. During local summer of the Northern Hemisphere, there is a clear channeling of return currents over the polar cap. For positive (negative) IMF By a dominant eastward (westward) Hall current circuit is formed from the afternoon (morning) electrojet towards the dawn side (dusk side) polar cap return current. The direction of polar cap Hall currents in the noon sector depends directly on the orientation of the IMF By. This is true for both signs of the IMF Bz component. Comparable Hall current distributions can be observed in the Southern Hemisphere but for opposite IMF By signs. Around the midnight sector the westward substorm electrojet is dominating. As expected, it is highly dependent on magnetic activity, but it shows only little response to season and IMF By polarity. An important finding is that all the IMF By dependences of FACs and Hall currents practically disappear in the dark winter hemisphere.

Improvements in Health Behaviors, Eating Self-Efficacy, and Goal-Setting Skills Following Participation in Wellness Coaching.

PubMed

Clark, Matthew M; Bradley, Karleah L; Jenkins, Sarah M; Mettler, Emily A; Larson, Brent G; Preston, Heather R; Liesinger, Juliette T; Werneburg, Brooke L; Hagen, Philip T; Harris, Ann M; Riley, Beth A; Olsen, Kerry D; Vickers Douglas, Kristin S

2016-07-01

Purpose . This project examined potential changes in health behaviors following wellness coaching. Design . In a single cohort study design, wellness coaching participants were recruited in 2011, data were collected through July 2012, and were analyzed through December 2013. Items in the study questionnaire used requested information about 11 health behaviors, self-efficacy for eating, and goal-setting skills. Setting . Worksite wellness center. Participants . One-hundred employee wellness center members with an average age of 42 years; 90% were female and most were overweight or obese. Intervention . Twelve weeks of in-person, one-on-one wellness coaching. Method . Participants completed study questionnaires when they started wellness coaching (baseline), after 12 weeks of wellness coaching, and at a 3-month follow-up. Results . From baseline to week 12, these 100 wellness coaching participants improved their self-reported health behaviors (11 domains, 0- to 10-point scale) from an average of 6.4 to 7.7 (p < .001), eating self-efficacy from an average of 112 to 142 (on a 0- to 180-point scale; p < .001), and goal-setting skills from an average of 49 to 55 (on a 16- to 80-point scale; p < .001). Conclusion . These results suggest that participants improved their current health behaviors and learned skills for continued healthy living. Future studies that use randomized controlled trials are needed to establish causality for wellness coaching.

Determination of the Peltier Coefficient of Germanium in a Vertical Bridgeman-Stockbarger Furnace

NASA Technical Reports Server (NTRS)

Weigel, Michaela E. K.; Matthiesen, David H.

1997-01-01

The Peltier effect is the fundamental mechanism that makes interface demarcation through current pulsing possible. If a method for calculating the necessary current density for effective demarcation is to be developed, it will be necessary to know the value of the Peltier coefficient. This study determined experimentally the value of the Peltier coefficient for gallium-doped germanium by comparing the change in average growth rates between current-on and current-off periods. Current-on and current-off layer thickness measurements were made using differential interference contrast microscopy and atomic force microscopy. It was found that the Joule and Thomson effects could not be neglected. Peltier coefficients calculated from the experimental data with an analysis that accounts for Joule, Thomson, and Peltier effects yielded an average value for the Peltier coefficient of 0.076 +/- 0.015 V.

Reprint of Mechanisms of maintaining high suspended sediment concentration over tide-dominated offshore shoals in the southern Yellow Sea

NASA Astrophysics Data System (ADS)

Xiong, Jilian; Wang, Xiao Hua; Wang, Ya Ping; Chen, Jingdong; Shi, Benwei; Gao, Jianhua; Yang, Yang; Yu, Qian; Li, Mingliang; Yang, Lei; Gong, Xulong

2018-06-01

An understanding of the dynamics and behaviors of suspended sediments is vital in analysis of morphological, environmental, and ecological processes occurring in coastal marine environments. To study the mechanisms of maintaining high suspended sediment concentrations (SSCs) on a tide-dominated offshore shoal, we measured water depths, current velocities, SSCs, wave parameters and bottom sediment compositions in the southern Yellow Sea. These data were then used to calculate bottom shear stresses generated by currents (τc), waves (τw), and wave-current interactions (τcw). SSCs time series exhibited strong quarter-diurnal peaks during spring tides, in contrast to the semidiurnal signal during neap tides. A Fourier analysis showed that suspended sediment variations within tidal cycles was mainly controlled by resuspension in most stations. There existed relatively stable background SSCs (maintaining high SSCs among tidal cycles) values at all four stations during both windy (wind speed > 9.0 m/s) and normal weather conditions (wind speed < 3.0 m/s). The background SSCs had strong relationship with spring/neap-averaged τcw, indicating background SSCs were mainly controlled by mean bottom shear stress, with a minimum value of 0.21 N/m2. On account of the strong tidal currents, background SSCs of spring tides were greater than that of neap tides. In addition, on the base of wavelet, statistics analyses and turbulence dissipation parameter, background SSCs during slack tide in the study area may be maintained by intermittent turbulence events induced by a combined tidal current and wave action.

Mechanisms of maintaining high suspended sediment concentration over tide-dominated offshore shoals in the southern Yellow Sea

NASA Astrophysics Data System (ADS)

Xiong, Jilian; Wang, Xiao Hua; Wang, Ya Ping; Chen, Jingdong; Shi, Benwei; Gao, Jianhua; Yang, Yang; Yu, Qian; Li, Mingliang; Yang, Lei; Gong, Xulong

2017-05-01

An understanding of the dynamics and behaviors of suspended sediments is vital in analysis of morphological, environmental, and ecological processes occurring in coastal marine environments. To study the mechanisms of maintaining high suspended sediment concentrations (SSCs) on a tide-dominated offshore shoal, we measured water depths, current velocities, SSCs, wave parameters and bottom sediment compositions in the southern Yellow Sea. These data were then used to calculate bottom shear stresses generated by currents (τc), waves (τw), and wave-current interactions (τcw). SSCs time series exhibited strong quarter-diurnal peaks during spring tides, in contrast to the semidiurnal signal during neap tides. A Fourier analysis showed that suspended sediment variations within tidal cycles was mainly controlled by resuspension in most stations. There existed relatively stable background SSCs (maintaining high SSCs among tidal cycles) values at all four stations during both windy (wind speed > 9.0 m/s) and normal weather conditions (wind speed < 3.0 m/s). The background SSCs had strong relationship with spring/neap-averaged τcw, indicating background SSCs were mainly controlled by mean bottom shear stress, with a minimum value of 0.21 N/m2. On account of the strong tidal currents, background SSCs of spring tides were greater than that of neap tides. In addition, on the base of wavelet, statistics analyses and turbulence dissipation parameter, background SSCs during slack tide in the study area may be maintained by intermittent turbulence events induced by a combined tidal current and wave action.

[Analysis of the characteristic of pharyngeal paraesthesia patients by high resolution manometry].

PubMed

Gu, Yun; Qian, Wei

2015-09-01

To discuss the pressure changing characteristics of upper esophageal sphincter (UES), lower esophageal sphincter (LES) and the esophagus kinetic characteristics of pharyngeal paraesthesia patients. To take high resolution manometry in 44 cases of pharyngeal paraesthesia patients and 23 normal subjects separately. According to the RSI score,the 44 patients were divided into group A (the group without reflux, RSI < 13, n = 25) and group B (the group with reflux, RSI ≥ 13, n = 19). The UES average resting pressure and average residual pressure of patients group were higher than the control group (P < 0.05); The UES average resting pressure and average residual pressure of group B were higher than group A (P < 0.05); The LES average resting pressure and average residual pressure of group B were lower than group A and the control group (P < 0.05); The comparison of LES average resting pressure and average residual pressure between group A and the control group was not statistically significant (P > 0.05). The esophagus DCI of group B was lower than that of group A and control group (P < 0.05). The esophagus DCI comparison between group A and control group was not statistically significant (P > 0.05). The pharyngeal paresthesia symptoms of'patients was associated with the increasing of UES pressure. The pharyngeal paresthesia symptoms of group with reflux was related to low pressure of LES and high pressure of UES. The last part of esophagus of group with reflux had obstacles in powers, which weaken the peristalsis and declined the ability to clear the bolus and gastric reflux material.

The Effects of Exercising in Different Natural Environments on Psycho-Physiological Outcomes in Post-Menopausal Women: A Simulation Study.

PubMed

White, Mathew P; Pahl, Sabine; Ashbullby, Katherine J; Burton, Francesca; Depledge, Michael H

2015-09-23

The current study examined potential psycho-physiological benefits from exercising in simulated natural environments among a sample of post-menopausal women using a laboratory based protocol. Participants cycled on a stationary exercise bike for 15 min while facing either a blank wall (Control) or while watching one of three videos: Urban (Grey), Countryside (Green), Coast (Blue). Blood pressure, heart rate and affective responses were measured pre-post. Heart rate, affect, perceived exertion and time perception were also measured at 5, 10 and 15 min during exercise. Experience evaluation was measured at the end. Replicating most earlier findings, affective, but not physiological, outcomes were more positive for exercise in the simulated Green and, for the first time, Blue environment, compared to Control. Moreover, only the simulated Blue environment was associated with shorter perceived exercise duration than Control and participants were most willing to repeat exercise in the Blue setting. The current research extended earlier work by exploring the effects of "blue exercise" and by using a demographic with relatively low average levels of physical activity. That this sample of postmenopausal women were most willing to repeat a bout of exercise in a simulated Blue environment may be important for physical activity promotion in this cohort.

The Effects of Exercising in Different Natural Environments on Psycho-Physiological Outcomes in Post-Menopausal Women: A Simulation Study

PubMed Central

White, Mathew P.; Pahl, Sabine; Ashbullby, Katherine J.; Burton, Francesca; Depledge, Michael H.

2015-01-01

The current study examined potential psycho-physiological benefits from exercising in simulated natural environments among a sample of post-menopausal women using a laboratory based protocol. Participants cycled on a stationary exercise bike for 15 min while facing either a blank wall (Control) or while watching one of three videos: Urban (Grey), Countryside (Green), Coast (Blue). Blood pressure, heart rate and affective responses were measured pre-post. Heart rate, affect, perceived exertion and time perception were also measured at 5, 10 and 15 min during exercise. Experience evaluation was measured at the end. Replicating most earlier findings, affective, but not physiological, outcomes were more positive for exercise in the simulated Green and, for the first time, Blue environment, compared to Control. Moreover, only the simulated Blue environment was associated with shorter perceived exercise duration than Control and participants were most willing to repeat exercise in the Blue setting. The current research extended earlier work by exploring the effects of “blue exercise” and by using a demographic with relatively low average levels of physical activity. That this sample of postmenopausal women were most willing to repeat a bout of exercise in a simulated Blue environment may be important for physical activity promotion in this cohort. PMID:26404351

An area and power-efficient analog li-ion battery charger circuit.

PubMed

Do Valle, Bruno; Wentz, Christian T; Sarpeshkar, Rahul

2011-04-01

The demand for greater battery life in low-power consumer electronics and implantable medical devices presents a need for improved energy efficiency in the management of small rechargeable cells. This paper describes an ultra-compact analog lithium-ion (Li-ion) battery charger with high energy efficiency. The charger presented here utilizes the tanh basis function of a subthreshold operational transconductance amplifier to smoothly transition between constant-current and constant-voltage charging regimes without the need for additional area- and power-consuming control circuitry. Current-domain circuitry for end-of-charge detection negates the need for precision-sense resistors in either the charging path or control loop. We show theoretically and experimentally that the low-frequency pole-zero nature of most battery impedances leads to inherent stability of the analog control loop. The circuit was fabricated in an AMI 0.5-μm complementary metal-oxide semiconductor process, and achieves 89.7% average power efficiency and an end voltage accuracy of 99.9% relative to the desired target 4.2 V, while consuming 0.16 mm(2) of chip area. To date and to the best of our knowledge, this design represents the most area-efficient and most energy-efficient battery charger circuit reported in the literature.

Two-dimensional velocity, optical risetime, and peak current estimates for natural positive lightning return strokes

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Rust, W. D.

1993-01-01

Velocities, optical risetimes, and transmission line model peak currents for seven natural positive return strokes are reported. The average 2D positive return stroke velocity for channel segments of less than 500 m in length starting near the base of the channel is 0.8 +/- 0.3 x 10 exp 8 m/s, which is slower than the present corresponding average velocity for natural negative first return strokes of 1.7 +/- 0.7 x 10 exp 8/s. It is inferred that positive stroke peak currents in the literature, which assume the same velocity as negative strokes, are low by a factor of 2. The average 2D positive return stroke velocity for channel segments of greater than 500 m starting near the base of the channel is 0.9 +/- 0.4 x 10 exp 8 m/s. The corresponding average velocity for the present natural negative first strokes is 1.2 +/- 0.6 x 10 exp 8 m/s. No significant velocity change with height is found for positive return strokes.

Performance test of nutrient control equipment for hydroponic plants

NASA Astrophysics Data System (ADS)

Rahman, Nurhaidar; Kuala, S. I.; Tribowo, R. I.; Anggara, C. E. W.; Susanti, N. D.

2017-11-01

Automatic control equipment has been made for the nutrient content in irrigation water for hydroponic plants. Automatic control equipment with CCT53200E conductivity controller to nutrient content in irrigation water for hydroponic plants, can be used to control the amount of TDS of nutrient solution in the range of TDS numbers that can be set according to the range of TDS requirements for the growth of hydroponically cultivated crops. This equipment can minimize the work time of hydroponic crop cultivators. The equipment measurement range is set between 1260 ppm up to 1610 ppm for spinach plants. Caisim plants were included in this experiment along with spinach plants with a spinach plants TDS range. The average of TDS device is 1450 ppm, while manual (conventional) is 1610 ppm. Nutrient solution in TDS controller has pH 5,5 and temperature 29,2 °C, while manual is pH 5,6 and temperature 31,3 °C. Manually treatment to hydroponic plant crop, yields in an average of 39.6 grams/plant, greater than the yield of spinach plants with TDS control equipment, which is in an average of 24.6 grams / plant. The yield of caisim plants by manual treatment is in an average of 32.3 grams/crop, less than caisim crop yields with TDS control equipment, which is in an average of 49.4 grams/plant.

TRANSP-based Trajectory Optimization of the Current Profile Evolution to Facilitate Robust Non-inductive Ramp-up in NSTX-U

NASA Astrophysics Data System (ADS)

Wehner, William; Schuster, Eugenio; Poli, Francesca

2016-10-01

Initial progress towards the design of non-inductive current ramp-up scenarios in the National Spherical Torus Experiment Upgrade (NSTX-U) has been made through the use of TRANSP predictive simulations. The strategy involves, first, ramping the plasma current with high harmonic fast waves (HHFW) to about 400 kA, and then further ramping to 900 kA with neutral beam injection (NBI). However, the early ramping of neutral beams and application of HHFW leads to an undesirably peaked current profile making the plasma unstable to ballooning modes. We present an optimization-based control approach to improve on the non-inductive ramp-up strategy. We combine the TRANSP code with an optimization algorithm based on sequential quadratic programming to search for time evolutions of the NBI powers, the HHFW powers, and the line averaged density that define an open-loop actuator strategy that maximizes the non-inductive current while satisfying constraints associated with the current profile evolution for MHD stable plasmas. This technique has the potential of playing a critical role in achieving robustly stable non-inductive ramp-up, which will ultimately be necessary to demonstrate applicability of the spherical torus concept to larger devices without sufficient room for a central coil. Supported by the US DOE under the SCGSR Program.

A comparison of alternative methods for measuring cigarette prices.

PubMed

Chaloupka, Frank J; Tauras, John A; Strasser, Julia H; Willis, Gordon; Gibson, James T; Hartman, Anne M

2015-05-01

Government agencies, public health organisations and tobacco control researchers rely on accurate estimates of cigarette prices for a variety of purposes. Since the 1950s, the Tax Burden on Tobacco (TBOT) has served as the most widely used source of this price data despite its limitations. This paper compares the prices and collection methods of the TBOT retail-based data and the 2003 and 2006/2007 waves of the population-based Tobacco Use Supplement to the Current Population Survey (TUS-CPS). From the TUS-CPS, we constructed multiple state-level measures of cigarette prices, including weighted average prices per pack (based on average prices for single-pack purchases and average prices for carton purchases) and compared these with the weighted average price data reported in the TBOT. We also constructed several measures of tax avoidance from the TUS-CPS self-reported data. For the 2003 wave, the average TUS-CPS price was 71 cents per pack less than the average TBOT price; for the 2006/2007 wave, the difference was 47 cents. TUS-CPS and TBOT prices were also significantly different at the state level. However, these differences varied widely by state due to tax avoidance opportunities, such as cross-border purchasing. The TUS-CPS can be used to construct valid measures of cigarette prices. Unlike the TBOT, the TUS-CPS captures the effect of price-reducing marketing strategies, as well as tax avoidance practices and non-traditional types of purchasing. Thus, self-reported data like TUS-CPS appear to have advantages over TBOT in estimating the 'real' price that smokers face. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Vehicle emissions and consumer information in car advertisements.

PubMed

Wilson, Nick; Maher, Anthony; Thomson, George; Keall, Michael

2008-04-29

The advertising of vehicles has been studied from a safety perspective but not in terms of vehicle air pollutants. We aimed to examine the content and trends of greenhouse gas emissions and air pollution-related information, in light passenger vehicle advertisements. Content analysis of the two most popular current affairs magazines in New Zealand for the five year period 2001-2005 was undertaken (n = 514 advertisements). This was supplemented with vehicle data from official websites. The advertisements studied provided some information on fuel type (52%), and engine size (39%); but hardly any provided information on fuel efficiency (3%), or emissions (4%). Over the five-year period the reported engine size increased significantly, while fuel efficiency did not improve. For the vehicles advertised, for which relevant official website data could be obtained, the average "greenhouse rating" for carbon dioxide (CO2) emissions was 5.1, with a range from 0.5 to 8.5 (on a scale with 10 being the best and 0.5 being the most polluting). The average CO2 emissions were 50% higher than the average for cars made by European manufacturers. The average "air pollution" rating for the advertised vehicles was 5.4 (on the same 1-10 scale). The yearly averages for the "greenhouse" or "air pollution" ratings did not change significantly over the five-year period. One advertised hybrid vehicle had a fuel consumption that was under half the average (4.4 versus 9.9 L/100 km), as well as the best "greenhouse" and "air pollution" ratings. To enhance informed consumer choice and to control greenhouse gas and air pollution emissions, governments should introduce regulations on the content of vehicle advertisements and marketing (as started by the European Union). Similar regulations are already in place for the marketing of many other consumer products.

40 CFR Table 1 to Subpart Sssss of... - Emission Limits

Code of Federal Regulations, 2012 CFR

2012-07-01

... that are controlled with a thermal or catalytic oxidizer a. The 3-hour block average THC concentration... the outlet of the control device; or b. The 3-hour block average THC mass emissions rate must be... than a thermal or catalytic oxidizer a. The 3-hour block average THC concentration must not exceed 20...

40 CFR Table 1 to Subpart Sssss of... - Emission Limits

Code of Federal Regulations, 2013 CFR

2013-07-01

... that are controlled with a thermal or catalytic oxidizer a. The 3-hour block average THC concentration... the outlet of the control device; or b. The 3-hour block average THC mass emissions rate must be... than a thermal or catalytic oxidizer a. The 3-hour block average THC concentration must not exceed 20...

40 CFR Table 1 to Subpart Sssss of... - Emission Limits

Code of Federal Regulations, 2014 CFR

2014-07-01

... that are controlled with a thermal or catalytic oxidizer a. The 3-hour block average THC concentration... the outlet of the control device; or b. The 3-hour block average THC mass emissions rate must be... than a thermal or catalytic oxidizer a. The 3-hour block average THC concentration must not exceed 20...

40 CFR Table 1 to Subpart Sssss of... - Emission Limits

Code of Federal Regulations, 2011 CFR

2011-07-01

... that are controlled with a thermal or catalytic oxidizer a. The 3-hour block average THC concentration... the outlet of the control device; or b. The 3-hour block average THC mass emissions rate must be... than a thermal or catalytic oxidizer a. The 3-hour block average THC concentration must not exceed 20...

40 CFR Table 1 to Subpart Sssss of... - Emission Limits

Code of Federal Regulations, 2010 CFR

2010-07-01

... that are controlled with a thermal or catalytic oxidizer a. The 3-hour block average THC concentration... the outlet of the control device; or b. The 3-hour block average THC mass emissions rate must be... than a thermal or catalytic oxidizer a. The 3-hour block average THC concentration must not exceed 20...

Influence Assessment of Multiple Large-sized Reservoirs on Flooding in the Huai River Watershed, China

NASA Astrophysics Data System (ADS)

Wan, X. Y.

2017-12-01

The extensive constructions of reservoirs change the hydrologic characteristics of the associated watersheds, which obviously increases the complexity of watershed flood control decisions. By evaluating the impacts of the multi-reservoir system on the flood hydrograph, it becomes possible to improve the effectiveness of the flood control decisions. In this paper we compare the non-reservoir flood hydrograph with the actual observed flood hydrograph using the Lutaizi upstream of Huai river in East China as a representative case, where 20 large-scale/large-sized reservoirs have been built. Based on the total impact of the multi-reservoir system, a novel strategy, namely reservoir successively added (RSA) method, is presented to evaluate the contribution of each reservoir to the total impact. According each reservoir contribution, the "highly effective" reservoirs for watershed flood control are identified via hierarchical clustering. Moreover, we estimate further the degree of impact of the reservoir current operation rules on the flood hydrograph on the base of the impact of dams themselves. As a result, we find that the RSA method provides a useful method for analysis of multi-reservoir systems by partitioning the contribution of each reservoir to the total impacts on the flooding at the downstream section. For all the historical large floods examined, the multi-reservoir system in the Huai river watershed has a significant impact on flooding at the downstream Lutaizi section, on average reducing the flood volume and peak discharge by 13.92 × 108 m3 and 18.7% respectively. It is more informative to evaluate the maximum impact of each reservoir (on flooding at the downstream section) than to examine the average impact. Each reservoir has a different impact on the flood hydrograph at the Lutaizi section. In particular, the Meishan, Xianghongdian, Suyahu, Nanwan, Nianyushan and Foziling reservoirs exert a strong influence on the flood hydrograph, and are therefore important for flood control on the Huai river. Under the current operation rules, the volume and peak discharge of flooding at the Lutaizi section are reduced by 13.69 × 108m3 and 1429 m3/s respectively, accounting for 98% and 80.5% of the real reduction respectively.

Alternative Fuels Data Center: Low Rolling Resistance Tires

Science.gov Websites

meet their Corporate Average Fuel Economy (CAFE) standards. However, no requirements are currently Rolling Resistance Part 1: Understanding Corporate Average Fuel Economy Definitions 1015 Driving Cycle A

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

Muller, L; Soldner, A; Kirk, M

Purpose: The beam range uncertainty presents a special challenge for proton therapy. Novel technologies currently under development offer strategies to reduce the range uncertainty [1,2]. This work quantifies the potential advantages that could be realized by such a reduction for dosimetrically challenging chordomas at the base of skull. Therapeutic improvement was assessed by evaluating tumor control probabilities (TCP) and normal tissue complication probabilities (NTCP). Methods: Treatment plans were made for a modulated-scanned proton delivery technique using the Eclipse treatment planning system. The prescription dose was 7920 cGy to the CTV. Three different range uncertainty scenarios were considered: 5 mm (3.5%more » of the beam range + 1 mm, representing current clinical practice, “Curr”), 2 mm (1.3%), and 1 mm (0.7%). For each of 4 patients, 3 different PTVs were defined via uniform expansion of the CTV by the value of the range uncertainty. Tumor control probability (TCP) and normal tissue complication probabilities (NTCPs) for organs-at-risk (OARs) were calculated using the Lyman-Kutcher-Burman[3] formalism and published model parameters [ref Terahara[4], quantec S10, Burman Red Journal v21 pp 123]. Our plan optimization strategy was to achieve PTV close to prescription while maintaining OAR NTCP values at or better than the Curr plan. Results: The average TCP values for the 5, 2, and 1 mm range uncertainty scenarios are 51%, 55% and 65%. The improvement in TCP for patients was between 4 and 30%, depending primarily on the proximity of the GTV to OAR. The average NTCPs for the brainstem and cord were about 4% and 1%, respectively, for all target margins. Conclusion: For base of skull chordomas, reduced target margins can substantially increase the TCP without increasing the NTCP. This work demonstrates the potential significance of a reduction in the range uncertainty for proton beams.« less

Anodal transcranial direct current stimulation to the cerebellum improves handwriting and cyclic drawing kinematics in focal hand dystonia.

PubMed

Bradnam, Lynley V; Graetz, Lynton J; McDonnell, Michelle N; Ridding, Michael C

2015-01-01

There is increasing evidence that the cerebellum has a role in the pathophysiology of primary focal hand dystonia and might provide an intervention target for non-invasive brain stimulation to improve function of the affected hand. The primary objective of this study was to determine if cerebellar transcranial direct current stimulation (tDCS) improves handwriting and cyclic drawing kinematics in people with hand dystonia, by reducing cerebellar-brain inhibition (CBI) evoked by transcranial magnetic stimulation (TMS). Eight people with dystonia (5 writer's dystonia, 3 musician's dystonia) and eight age-matched controls completed the study and underwent cerebellar anodal, cathodal and sham tDCS in separate sessions. Dystonia severity was assessed using the Writer's Cramp Rating Scale (WRCS) and the Arm Dystonia Disability Scale (ADDS). The kinematic measures that differentiated the groups were; mean stroke frequency during handwriting and fast cyclic drawing and average pen pressure during light cyclic drawing. TMS measures of cortical excitability were no different between people with FHD and controls. There was a moderate, negative relationship between TMS-evoked CBI at baseline and the WRCS in dystonia. Anodal cerebellar tDCS reduced handwriting mean stroke frequency and average pen pressure, and increased speed and reduced pen pressure during fast cyclic drawing. Kinematic measures were not associated with a decrease in CBI within an individual. In conclusion, cerebellar anodal tDCS appeared to improve kinematics of handwriting and circle drawing tasks; but the underlying neurophysiological mechanism remains uncertain. A study in a larger homogeneous population is needed to further investigate the possible therapeutic benefit of cerebellar tDCS in dystonia.

Anodal transcranial direct current stimulation to the cerebellum improves handwriting and cyclic drawing kinematics in focal hand dystonia

PubMed Central

Bradnam, Lynley V.; Graetz, Lynton J.; McDonnell, Michelle N.; Ridding, Michael C.

2015-01-01

There is increasing evidence that the cerebellum has a role in the pathophysiology of primary focal hand dystonia and might provide an intervention target for non-invasive brain stimulation to improve function of the affected hand. The primary objective of this study was to determine if cerebellar transcranial direct current stimulation (tDCS) improves handwriting and cyclic drawing kinematics in people with hand dystonia, by reducing cerebellar-brain inhibition (CBI) evoked by transcranial magnetic stimulation (TMS). Eight people with dystonia (5 writer’s dystonia, 3 musician’s dystonia) and eight age-matched controls completed the study and underwent cerebellar anodal, cathodal and sham tDCS in separate sessions. Dystonia severity was assessed using the Writer’s Cramp Rating Scale (WRCS) and the Arm Dystonia Disability Scale (ADDS). The kinematic measures that differentiated the groups were; mean stroke frequency during handwriting and fast cyclic drawing and average pen pressure during light cyclic drawing. TMS measures of cortical excitability were no different between people with FHD and controls. There was a moderate, negative relationship between TMS-evoked CBI at baseline and the WRCS in dystonia. Anodal cerebellar tDCS reduced handwriting mean stroke frequency and average pen pressure, and increased speed and reduced pen pressure during fast cyclic drawing. Kinematic measures were not associated with a decrease in CBI within an individual. In conclusion, cerebellar anodal tDCS appeared to improve kinematics of handwriting and circle drawing tasks; but the underlying neurophysiological mechanism remains uncertain. A study in a larger homogeneous population is needed to further investigate the possible therapeutic benefit of cerebellar tDCS in dystonia. PMID:26042019

Silicon tunnel FET with average subthreshold slope of 55 mV/dec at low drain currents

NASA Astrophysics Data System (ADS)

Narimani, K.; Glass, S.; Bernardy, P.; von den Driesch, N.; Zhao, Q. T.; Mantl, S.

2018-05-01

In this paper we present a silicon tunnel FET based on line-tunneling to achieve better subthreshold performance. The fabricated device shows an on-current of Ion = 2.55 × 10-7 A/μm at Vds = Von = Vgs - Voff = -0.5 V for an Ioff = 1 nA/μm and an average SS of 55 mV/dec over two orders of magnitude of Id. Furthermore, the analog figures of merit have been calculated and show that the transconductance efficiency gm/Id beats the MOSFET performance at low currents.

Enforcement of underage sales laws as a predictor of daily smoking among adolescents: a national study.

PubMed

DiFranza, Joseph R; Savageau, Judith A; Fletcher, Kenneth E

2009-04-17

With a goal to reduce youth smoking rates, the U.S. federal government mandated that states enforce laws prohibiting underage tobacco sales. Our objective was to determine if state compliance with tobacco sales laws is associated with a decreased risk of current daily smoking among adolescents. Data on tobacco use were obtained from a nationally representative sample of 16,244 adolescents from the 2003 Monitoring the Future survey. The association between merchant compliance with the law from 1997-2003 and current daily smoking was examined using logistic regression while controlling for cigarette prices, state restaurant smoking policies, anti-tobacco media, and demographic variables. Higher average state merchant compliance from 1997-2003 predicted lower levels of current daily smoking among adolescents when controlled for all other factors. The odds ratio for daily smoking was reduced by 2% for each 1% increase in merchant compliance. After controlling for price changes, media campaigns and smoking restrictions, a 20.8% reduction in the odds of smoking among 10th graders in 2003 was attributed to the observed improvement in merchant compliance between 1997 and 2003. A 47% reduction in the odds of daily smoking could be attributed to price increases over this period. Federally mandated enforcement efforts by states to prevent the sale of tobacco to minors appear to have made an important contribution to the observed decline in smoking among youth in the U.S. Given similar results from long-term enforcement efforts in Australia, other countries should be encouraged to adopt the World Health Organization Framework on Tobacco Control strategies to reduce the sale of tobacco to minors.

Safety approaches for high power modular laser operation

NASA Astrophysics Data System (ADS)

Handren, R. T.

1993-03-01

Approximately 20 years ago, a program was initiated at the Lawrence Livermore National Laboratory (LLNL) to study the feasibility of using lasers to separate isotopes of uranium and other materials. Of particular interest was the development of a uranium enrichment method for the production of commercial nuclear power reactor fuel to replace current more expensive methods. The Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) Program progressed to the point where a plant-scale facility to demonstrate commercial feasibility was built and is being tested. The U-AVLIS Program uses copper vapor lasers which pump frequency selective dye lasers to photoionize uranium vapor produced by an electron beam. The selectively ionized isotopes are electrostatically collected. The copper lasers are arranged in oscillator/amplifier chains. The current configuration consists of 12 chains, each with a nominal output of 800 W for a system output in excess of 9 kW. The system requirements are for continuous operation (24 h a day, 7 days a week) and high availability. To meet these requirements, the lasers are designed in a modular form allowing for rapid change-out of the lasers requiring maintenance. Since beginning operation in early 1985, the copper lasers have accumulated over 2 million unit hours at a greater than 90% availability. The dye laser system provides approximately 2.5 kW average power in the visible wavelength range. This large-scale laser system has many safety considerations, including high-power laser beams, high voltage, and large quantities (approximately 3000 gal) of ethanol dye solutions. The Laboratory's safety policy requires that safety controls be designed into any process, equipment, or apparatus in the form of engineering controls. Administrative controls further reduce the risk to an acceptable level. Selected examples of engineering and administrative controls currently being used in the U-AVLIS Program are described.

The adequacy of current import and export controls on sealed radioactive sources.

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

Longley, Susan W.; Cochran, John Russell; Price, Laura L.

2003-10-01

Millions of sealed radioactive sources (SRSs) are being used for a wide variety of beneficial purposes throughout the world. Security experts are now concerned that these beneficial SRSs could be used in a radiological dispersion device to terrorize and disrupt society. The greatest safety and security threat is from those highly radioactive Category 1 and 2 SRSs. Without adequate controls, it may be relatively easy to legally purchase a Category 1 or 2 SRS on the international market under false pretenses. Additionally, during transfer, SRSs are particularly susceptible to theft since the sources are in a shielded and mobile configuration,more » transportation routes are predictable, and shipments may not be adequately guarded. To determine if government controls on SRS are adequate, this study was commissioned to review the current SRS import and export controls of six countries. Canada, the Russian Federation, and South Africa were selected as the exporting countries, and Egypt, the Philippines, and the United States were selected as importing countries. A detailed review of the controls in each country is presented. The authors found that Canada and Russia are major exporters, and are exporting highly radioactive SRSs without first determining if the recipient is authorized by the receiving country to own and use the SRSs. Available evidence was used to estimate that on average there are tens to possibly hundreds of intercountry transfers of highly radioactive SRSs each day. Based on these and other findings, this reports recommends stronger controls on the export and import of highly radioactive SRSs.« less

Development and validation of a weather-based warning system to advise fungicide applications to control dollar spot on turfgrass.

PubMed

Smith, D L; Kerns, J P; Walker, N R; Payne, A F; Horvath, B; Inguagiato, J C; Kaminski, J E; Tomaso-Peterson, M; Koch, P L

2018-01-01

Dollar spot is one of the most common diseases of golf course turfgrass and numerous fungicide applications are often required to provide adequate control. Weather-based disease warning systems have been developed to more accurately time fungicide applications; however, they tend to be ineffective and are not currently in widespread use. The primary objective of this research was to develop a new weather-based disease warning system to more accurately advise fungicide applications to control dollar spot activity across a broad geographic and climactic range. The new dollar spot warning system was developed from data collected at field sites in Madison, WI and Stillwater, OK in 2008 and warning system validation sites were established in Madison, WI, Stillwater, OK, Knoxville, TN, State College, PA, Starkville, MS, and Storrs, CT between 2011 and 2016. A meta-analysis of all site-years was conducted and the most effective warning system for dollar spot development consisted of a five-day moving average of relative humidity and average daily temperature. Using this model the highest effective probability that provided dollar spot control similar to that of a calendar-based program across the numerous sites and years was 20%. Additional analysis found that the 20% spray threshold provided comparable control to the calendar-based program while reducing fungicide usage by up to 30%, though further refinement may be needed as practitioners implement this warning system in a range of environments not tested here. The weather-based dollar spot warning system presented here will likely become an important tool for implementing precision disease management strategies for future turfgrass managers, especially as financial and regulatory pressures increase the need to reduce pesticide usage on golf course turfgrass.

Development and validation of a weather-based warning system to advise fungicide applications to control dollar spot on turfgrass

PubMed Central

Smith, D. L.; Kerns, J. P.; Walker, N. R.; Payne, A. F.; Horvath, B.; Inguagiato, J. C.; Kaminski, J. E.; Tomaso-Peterson, M.

2018-01-01

Dollar spot is one of the most common diseases of golf course turfgrass and numerous fungicide applications are often required to provide adequate control. Weather-based disease warning systems have been developed to more accurately time fungicide applications; however, they tend to be ineffective and are not currently in widespread use. The primary objective of this research was to develop a new weather-based disease warning system to more accurately advise fungicide applications to control dollar spot activity across a broad geographic and climactic range. The new dollar spot warning system was developed from data collected at field sites in Madison, WI and Stillwater, OK in 2008 and warning system validation sites were established in Madison, WI, Stillwater, OK, Knoxville, TN, State College, PA, Starkville, MS, and Storrs, CT between 2011 and 2016. A meta-analysis of all site-years was conducted and the most effective warning system for dollar spot development consisted of a five-day moving average of relative humidity and average daily temperature. Using this model the highest effective probability that provided dollar spot control similar to that of a calendar-based program across the numerous sites and years was 20%. Additional analysis found that the 20% spray threshold provided comparable control to the calendar-based program while reducing fungicide usage by up to 30%, though further refinement may be needed as practitioners implement this warning system in a range of environments not tested here. The weather-based dollar spot warning system presented here will likely become an important tool for implementing precision disease management strategies for future turfgrass managers, especially as financial and regulatory pressures increase the need to reduce pesticide usage on golf course turfgrass. PMID:29522560

Missed opportunities to improve the health of postpartum women: high rates of untreated hypertension in rural Tanzania

PubMed Central

Larson, Elysia; Rabkin, Miriam; Mbaruku, Godfrey M.; Mbatia, Redempta; Kruk, Margaret E.

2017-01-01

Objectives To assess the prevalence of high blood pressure amongst postpartum women in rural Tanzania, and to explore factors associated with hypertension prevalence, awareness of their own hypertension, treatment, and control. Methods We conducted a cross-sectional study of 1,849 women in Tanzania’s Pwani Region who delivered a child in the prior year. We measured blood pressure, administered a structured questionnaire, and assessed factors associated with hypertension (HTN) prevalence, women’s awareness of their own HTN, treatment, and control of HTN using bivariable and multivariable logistic regressions. Findings 26.7% of women had high blood pressure and/or were taking antihypertensive medication. Women were on average 27.5 years old (range 15–54). Nearly all women (99.5%) reported contact with the health system during their pregnancy and delivery, with 97.0% reporting at least one antenatal care visit, 81.4% reporting facility delivery, and an overall average of 5.2 visits for their own care in the past year. Only 23.5% of those with HTN were aware of their diagnosis, 17.4% were taking medication, and only 10.5% had controlled blood pressure. In multivariable analysis, facility delivery, health insurance, and increased distance from a hospital were associated with increased likelihood of HTN awareness; facility delivery and hospital distance were associated with current hypertensive treatment; younger age and increased hospital distance were associated with control of HTN. Conclusion The prevalence of high blood pressure in this postpartum population was high, and despite frequent recent contacts with the health system, awareness, treatment and control of HTN were low. These findings highlight an important missed opportunity to improve women’s health during antenatal and postnatal care. PMID:28120288

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands.

PubMed

Turetsky, Merritt R; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B; Crill, Patrick; Hornibrook, Ed R C; Minkkinen, Kari; Moore, Tim R; Myers-Smith, Isla H; Nykänen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J Michael; White, Jeffrey R; Wickland, Kimberly P; Wilmking, Martin

2014-07-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release. © 2014 John Wiley & Sons Ltd.

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands

USGS Publications Warehouse

Turetsky, Merritt R.; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B.; Crill, Patrick; Hornibrook, Ed R.C.; Minkkinen, Kari; Moore, Tim R.; Myers-Smith, Isla H.; Nykanen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J. Michael; White, Jeffrey R.; Wickland, Kimberly P.; Wilmking, Martin

2014-01-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release.

Average of delta: a new quality control tool for clinical laboratories.

PubMed

Jones, Graham R D

2016-01-01

Average of normals is a tool used to control assay performance using the average of a series of results from patients' samples. Delta checking is a process of identifying errors in individual patient results by reviewing the difference from previous results of the same patient. This paper introduces a novel alternate approach, average of delta, which combines these concepts to use the average of a number of sequential delta values to identify changes in assay performance. Models for average of delta and average of normals were developed in a spreadsheet application. The model assessed the expected scatter of average of delta and average of normals functions and the effect of assay bias for different values of analytical imprecision and within- and between-subject biological variation and the number of samples included in the calculations. The final assessment was the number of patients' samples required to identify an added bias with 90% certainty. The model demonstrated that with larger numbers of delta values, the average of delta function was tighter (lower coefficient of variation). The optimal number of samples for bias detection with average of delta was likely to be between 5 and 20 for most settings and that average of delta outperformed average of normals when the within-subject biological variation was small relative to the between-subject variation. Average of delta provides a possible additional assay quality control tool which theoretical modelling predicts may be more valuable than average of normals for analytes where the group biological variation is wide compared with within-subject variation and where there is a high rate of repeat testing in the laboratory patient population. © The Author(s) 2015.

Monitoring of international normalized ratios: comparison of community nurses with family physicians.

PubMed

Levine, Max A; Shao, Wei; Klein, Douglas

2012-08-01

To determine whether community-based, nurse-led monitoring of the international normalized ratio (INR) in patients requiring long-term warfarin therapy was comparable to traditional physician monitoring. A retrospective cohort analysis of patients taking long-term warfarin therapy. The study used data gathered from 3 family medicine clinics in a primary care network in Edmonton, Alta. Medical records of patients currently taking warfarin were examined. Implementation of nurse-led monitoring in a primary care network in place of standard family physician INR monitoring. The degree of INR control before and after the implementation of nurse-run INR monitoring was assessed. The average proportion of time spent outside of therapeutic INR ranges, as well as the average number of days between successive INR readings, was calculated and compared. The degree of control placed patients into either a good-control group (out of range ≤ 25% of the time) or a moderate-control group (out of range > 25% of the time) and these groups were compared. Before nurse monitoring, INR values were out of range 20.4% of the time; after nurse monitoring they were out of range 19.2% of the time (P = .115); the time between sequential INR readings also did not differ before and after implementation of nurse monitoring (23.9 vs 21.6 days, P = .789). Nurse-led monitoring of INR is as effective as traditional physician monitoring. Advantages of nurse-led monitoring might include freeing family physicians to see more patients or to spend less time at work. It might also represent potential cost savings.

Activity of ergoferon against lethal influenza A (H3N2) virus infection in mice.

PubMed

Skarnovich, Maria A; Emelyanova, Alexandra G; Petrova, Nataliia V; Borshcheva, Alena A; Gorbunov, Evgeniy A; Mazurkov, Oleg Yu; Skarnovich, Maksim O; Tarasov, Sergey A; Shishkina, Larisa N; Epstein, Oleg I

2017-01-01

The influenza A virus accounts for serious annual viral upper respiratory tract infections. It is constantly able to modify its antigenic structure, thus evading host defence mechanisms. Moreover, currently available anti-influenza agents have a rather limited application, emphasizing the further need for new effective treatments. One of them is ergoferon, a drug containing combined polyclonal antibodies - anti-interferon gamma, anti-CD4 receptor and anti-histamine - in released-active form. The purpose of the study was to assess ergoferon antiviral efficacy in mice challenged with the A/Aichi/2/68 (H3N2) influenza virus. The virus was inoculated intranasally at a 90% lethal dose. Ergoferon was administered at 0.4 ml/day per os in a preventive and therapeutic regimen - daily for 5 days prior to and for 16 days after the challenge. The reference product, Tamiflu (oseltamivir), was used as a positive control treatment - at 20 mg/kg/day for 5 days after the challenge. Mice in the negative control group received distilled water which had been utilized for test sample preparation; untreated control animals received no treatment. Antiviral efficacy was assessed by an increase in survival rate, average life expectancy and virus titre reduction in the challenged mouse lungs. Survival rate and average life expectancy values were increased significantly in groups treated with ergoferon and Tamiflu, as compared with controls. Lung virus titres were reduced in these groups as observed on days 2 and 4 post-inoculation. Ergoferon demonstrated antiviral activity by reducing the severity and duration of the major signs of induced influenza infection.

A study of the growth and decay of cigarette smoke NOx in ambient air under controlled conditions

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

Rickert, W.S.; Robinson, J.C.; Collishaw, N.E.

The amount of NO{sub 2} and NO produced by the machine smoking of cigarettes was determined for 15 commercial Canadian brands. Average yield of NO was 1.44 {mu}moles or about 13% of the average reported for American cigarettes. Levels of NO{sub 2} were all less than 12% of NO and were probably due to the oxidation of NO. In order to assess the contribution of tobacco smoke to levels of NO in ambient air, 5 brands of cigarettes were smoked in a 27 cubic meter controlled environment room. Ventilation conditions were either 2.5 or 5.0 air changes per hour (ACH)more » and each experiment was replicated 3 times for a total of 30 experiments. Ventilation rates of 0.3 and 1.5 ACH were also selected in a second series of experiments in which only one brand of cigarette was smoked. Least squares estimates for the effective ventilation rates were obtained in the usual manner after linearizing the decay portion of the NO time curve. In each of the experiments, the regression explained at least 95% of the variation in the levels of NO with time. Loss of NO due to factors other than ventilation appeared to be constant within experimental error and averaged 2.22 ACH. Equilibrium values for NO were grossly underestimated when results from currently accepted procedures for smoke analysis were used in modeling the growth and decay of NO. Goodness-of-fit was improved when equilibrium values were estimated based on observed levels in ambient air.« less

Boundary Layer Control of a Circular Cylinder Using a Synthetic Jet

DTIC Science & Technology

2005-06-01

Average Velocity at . 375 Hz .............................................................................65 Figure 54 Average Velocity at 0.45 Hz...Figure 53 Average Velocity at . 375 Hz Columns=0; Rows=0 Figure 54 Average Velocity at 0.45 Hz Columns=0; Rows=0 Figure 55 Average Velocity

Effects of microstructural defects on the performance of base-metal multilayer ceramic capacitors

NASA Astrophysics Data System (ADS)

Samantaray, Malay M.

Multilayer ceramic capacitors (MLCCs), owing to their processing conditions, can exhibit microstructure defects such as electrode porosity and roughness. The effect of such extrinsic defects on the electrical performance of these devices needs to be understood in order to achieve successful miniaturization into the submicron dielectric layer thickness regime. Specifically, the presence of non-planar and discontinuous electrodes can lead to local field enhancements while the relative morphologies of two adjacent electrodes determine variations in the local dielectric thickness. To study the effects of electrode morphologies, an analytical approach is taken to calculate the electric field enhancement and leakage current with respect to an ideal parallel-plate capacitor. Idealized electrode defects are used to simulate the electric field distribution. It is shown that the electrode roughness causes both the electric field and the leakage current to increase with respect to that of the ideal flat parallel-plate capacitor. Moreover, finite element methods are used to predict electric field enhancements by as high as 100% within capacitor structures containing rough interfaces and porosity. To understand the influence of microstructural defects on field distributions and leakage current, the real three-dimensional microstructure of local regions in MLCCs are reconstructed using a serial-sectioning technique in the focused ion beam. These microstructures are then converted into a finite element model in order to simulate the perturbations in electric field due to the presence of electrode defects. The electric field is three times the average value, and this leads to increase in current density of these devices. It is also shown that increasing sintering rates of MLCCs leads to improved electrode morphology with smoother more continuous electrodes, which in turn leads to a decrease in electric field enhancement and calculated leakage current density. To simulate scaling effects, the dielectric layer thickness is reduced from 2.0mum to 0.5mum in the three-dimensional microstructure keeping the same electrode morphology. It is seen that the effect of microstructure defects is more pronounced as one approaches thinner layers, leading to higher local electric field concentrations and a concomitant drop in insulation resistance. It is also seen that the electric field values are as high as 3.8 times the average field in termination regions due the disintegrated structure of the electrodes. In order to assess the effect of microstructure on MLCC performance, two sets of multilayer capacitors subjected to two vastly different sintering rates of 150ºC/hr and 3000ºC/hr are compared for their electrical properties. Capacitors with higher electrode continuity exhibit proportionally higher capacitance, provided the grain size distributions are similar. From the leakage current measurements, it is found that the Schottky barrier at the electrode-dielectric interface controls the conduction mechanism. This barrier height is calculated to be 1.06 eV for slow-fired MLCCs and was 1.15 for fast-fired MLCCs. This shows that high concentration of electrode defects cause field perturbations and subsequent drop in the net Schottky barrier height. These results are further supported by frequency-dependent impedance measurements. With temperature dependence behavior of current-voltage trends we note that below temperatures of 135°C, the conduction is controlled by interfacial effects, whereas at higher temperatures it is consistent with bulk-controlled space charge limited current for the samples that are highly reoxidized. The final part of this work studies the various aspects of the initial stages of degradation of MLCCs. MLCCs subjected to unipolar and bipolar degradation are studied for changes in microstructure and electrical properties. With bipolar degradation studies new insights into degradation are gained. First, the ionic accumulation with oxygen vacancies at cathodes is only partially reversible. This has implications on the controlling interface with electronic conduction. Also, it is shown that oxygen vacancy accumulation near the cathodes leads to a drop in insulation resistance. The capacitance also increases with progressive steps of degradation due to the effective thinning of dielectric layer. The reduction in interfacial resistance is also confirmed by impedance analysis. Finally, it is observed that on degradation, the dominant leakage current mechanism changes from being controlled by cathodic injection of electrons to being controlled by their anodic extraction. (Abstract shortened by UMI.)

40 CFR 63.1252 - Standards: General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... November 15, 1990 may not be included in an emissions averaging group, except where the level of control is... other than this subpart may not be credited in an emission averaging group, unless the level of control... routine maintenance for centralized combustion control devices. The owner or operator may operate non...

A lithotrophic microbial fuel cell operated with pseudomonads-dominated iron-oxidizing bacteria enriched at the anode

PubMed Central

Nguyen, Thuy Thu; Luong, Tha Thanh Thi; Tran, Phuong Hoang Nguyen; Bui, Ha Thi Viet; Nguyen, Huy Quang; Dinh, Hang Thuy; Kim, Byung Hong; Pham, Hai The

2015-01-01

In this study, we attempted to enrich neutrophilic iron bacteria in a microbial fuel cell (MFC)-type reactor in order to develop a lithotrophic MFC system that can utilize ferrous iron as an inorganic electron donor and operate at neutral pHs. Electrical currents were steadily generated at an average level of 0.6 mA (or 0.024 mA cm–2 of membrane area) in reactors initially inoculated with microbial sources and operated with 20 mM Fe2+ as the sole electron donor and 10 ohm external resistance; whereas in an uninoculated reactor (the control), the average current level only reached 0.2 mA (or 0.008 mA cm–2 of membrane area). In an inoculated MFC, the generation of electrical currents was correlated with increases in cell density of bacteria in the anode suspension and coupled with the oxidation of ferrous iron. Cultivation-based and denaturing gradient gel electrophoresis analyses both show the dominance of some Pseudomonas species in the anode communities of the MFCs. Fluorescent in-situ hybridization results revealed significant increases of neutrophilic iron-oxidizing bacteria in the anode community of an inoculated MFC. The results, altogether, prove the successful development of a lithotrophic MFC system with iron bacteria enriched at its anode and suggest a chemolithotrophic anode reaction involving some Pseudomonas species as key players in such a system. The system potentially offers unique applications, such as accelerated bioremediation or on-site biodetection of iron and/or manganese in water samples. PMID:25712332

The Influence of Reading on Vocabulary Growth: A Case for a Matthew Effect.

PubMed

Duff, Dawna; Tomblin, J Bruce; Catts, Hugh

2015-06-01

Individual differences in vocabulary development may affect academic or social opportunities. It has been proposed that individual differences in word reading could affect the rate of vocabulary growth, mediated by the amount of reading experience, a process referred to as a Matthew effect (Stanovich, 1986). In the current study, assessments of written word-reading skills in the 4th grade and oral vocabulary knowledge collected in kindergarten and in the 4th, 8th, and 10th grades from a large epidemiologically based sample (n = 485) allowed a test of the relationship of early word-reading skills and the subsequent rate of vocabulary growth. Consistent with the hypothesis, multilevel modeling revealed the rate of vocabulary growth after the 4th grade to be significantly related to 4th-grade word reading after controlling for kindergarten vocabulary level, that is, above average readers experienced a higher rate of vocabulary growth than did average readers. Vocabulary growth rate differences accumulated over time such that the effect on vocabulary size was large.

Cost analysis of a patient navigation system to increase screening colonoscopy adherence among urban minorities.

PubMed

Jandorf, Lina; Stossel, Lauren M; Cooperman, Julia L; Graff Zivin, Joshua; Ladabaum, Uri; Hall, Diana; Thélémaque, Linda D; Redd, William; Itzkowitz, Steven H

2013-02-01

Patient navigation (PN) is being used increasingly to help patients complete screening colonoscopy (SC) to prevent colorectal cancer. At their large, urban academic medical center with an open-access endoscopy system, the authors previously demonstrated that PN programs produced a colonoscopy completion rate of 78.5% in a cohort of 503 patients (predominantly African Americans and Latinos with public health insurance). Very little is known about the direct costs of implementing PN programs. The objective of the current study was to perform a detailed cost analysis of PN programs at the authors' institution from an institutional perspective. In 2 randomized controlled trials, average-risk patients who were referred for SC by primary care providers were recruited for PN between May 2008 and May 2010. Patients were randomized to 1 of 4 PN groups. The cost of PN and net income to the institution were determined in a cost analysis. Among 395 patients who completed colonoscopy, 53.4% underwent SC alone, 30.1% underwent colonoscopy with biopsy, and 16.5% underwent snare polypectomy. Accounting for the average contribution margins of each procedure type, the total revenue was $95,266.00. The total cost of PN was $14,027.30. Net income was $81,238.70. In a model sample of 1000 patients, net incomes for the institutional completion rate (approximately 80%), the historic PN program (approximately 65%), and the national average (approximately 50%) were compared. The current PN program generated additional net incomes of $35,035.50 and $44,956.00, respectively. PN among minority patients with mostly public health insurance generated additional income to the institution, mainly because of increased colonoscopy completion rates. Copyright © 2012 American Cancer Society.

Food contamination by PCBs and waste disposal crisis: Evidence from goat milk in Campania (Italy).

PubMed

Ferrante, M C; Fusco, G; Monnolo, A; Saggiomo, F; Guccione, J; Mercogliano, R; Clausi, M T

2017-11-01

The study aims at investigating whether, and if so, to what extent the strong presence of urban and industrial waste in a territory may cause PCB contamination in goat milk produced therein. We compared PCB concentrations in goat milk from three different locations in the Campania region (Italy). One of the three locations, together with its surrounding area, has long suffered from illegal waste disposal and burning mainly by the so-called Ecomafia. The other locations, not involved in these illegal activities, allowed us to create a control group of goats with characteristics very similar to those of main interest. In milk from the waste contaminated area we identified high PCB concentrations (six indicator PCBs amounted to 170 ng g -1 on lipid weight, on average), whereas there was an almost total absence of such pollutants in milk from the control group. Concentrations of the six indicator PCBs were above the current European maximum residue limit fixed by the EU. At the same time, we found a lower average value of lipid content and a negative relationship between lipid content and PCB concentrations. Evidence indicates the potential health risk for consumers living in areas involved in illegal dumping of waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effectiveness of an Internet Community for Severely Obese Women.

PubMed

Chomutare, Taridzo; Årsand, Eirik; Hartvigsen, Gunnar

2016-01-01

While Internet communities have become thriving sources of support, little is yet known about their effectiveness. We retrospectively sampled morbidly obese (Body Mass Index, BMI > 40) women who were active for at least a year in an Internet community. We compared self-reported weight changes between women who had high online participation levels (n = 71) versus those with low participation levels as control (n = 69). Women who actively participated online lost on average 7.52%, while those who were passive lost 5.39% of their original body weight. For active women, there was positive, albeit weak, correlation (r = 0.22, p < 0.05) between online participation levels and weight loss, while no significant correlation was noted for the control. Current results indicate modest evidence supporting active participation in Internet groups as an effective weight loss strategy for the target group.

Estimation of average daily traffic on local roads in Kentucky.

DOT National Transportation Integrated Search

2016-07-01

Kentucky Transportation Cabinet (KYTC) officials use annual average daily traffic (AADT) to estimate intersection : performance across the state maintained highway system. KYTC currently collects AADTs for state maintained : roads but frequently lack...

Refractory Materials for Flame Deflector Protection System Corrosion Control: Flame Deflector Protection System Life Cycle Cost Analysis Report

NASA Technical Reports Server (NTRS)

Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Coffman, Brekke E.; Kolody, Mark R.; Curran, Jerome P.; Trejo, David; Reinschmidt, Ken; Kim, Hyung-Jin

2009-01-01

A 20-year life cycle cost analysis was performed to compare the operational life cycle cost, processing/turnaround timelines, and operations manpower inspection/repair/refurbishment requirements for corrosion protection of the Kennedy Space Center launch pad flame deflector associated with the existing cast-in-place materials and a newer advanced refractory ceramic material. The analysis compared the estimated costs of(1) continuing to use of the current refractory material without any changes; (2) completely reconstructing the flame trench using the current refractory material; and (3) completely reconstructing the flame trench with a new high-performance refractory material. Cost estimates were based on an analysis of the amount of damage that occurs after each launch and an estimate of the average repair cost. Alternative 3 was found to save $32M compared to alternative 1 and $17M compared to alternative 2 over a 20-year life cycle.

Smoking and depressive symptoms in a college population.

PubMed

Lee Ridner, S; Staten, Ruth R; Danner, Fred W

2005-08-01

A number of studies have documented the relationship between smoking and depression in adolescent and adult populations. The purpose of this study was to examine the level of depressive symptoms among college-age smokers and to determine whether or not increases in cigarette use were associated with increases in the number of depressive symptoms. A non-experimental cross-sectional design was used. Of the random sample (N = 895), 28% were current smokers, and more than 26% of the total sample reported high levels of depressive symptoms. Current smokers were more likely to report an increased level of depressive symptoms than nonsmokers were. Correlates of depressive symptoms included grade point average, marijuana use, and increased work hours. When controlling for these variables, the number of days smoked was predictive of depressive symptoms. School nurses have an important role in preventing smoking and treating smokers, as well as in preparing adolescents for the transition to college where many begin smoking.

Surface plasma source with saddle antenna radio frequency plasma generator.

PubMed

Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

2012-02-01

A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

Cathodal transcranial direct current stimulation in children with dystonia: a pilot open-label trial.

PubMed

Young, Scott J; Bertucco, Matteo; Sheehan-Stross, Rebecca; Sanger, Terence D

2013-10-01

Studies suggest that dystonia is associated with increased motor cortex excitability. Cathodal transcranial direct current stimulation can temporarily reduce motor cortex excitability. To test whether stimulation of the motor cortex can reduce dystonic symptoms in children, we measured tracking performance and muscle overflow using an electromyogram tracking task before and after stimulation. Of 10 participants, 3 showed a significant reduction in overflow, and a fourth showed a significant reduction in tracking error. Overflow decreased more when the hand contralateral to the cathode performed the task than when the hand ipsilateral to the cathode performed the task. Averaged over all participants, the results did not reach statistical significance. These results suggest that cathodal stimulation may allow a subset of children to control muscles or reduce involuntary overflow activity. Further testing is needed to confirm these results in a blinded trial and identify the subset of children who are likely to respond.

Effect of surface roughness of trench sidewalls on electrical properties in 4H-SiC trench MOSFETs

NASA Astrophysics Data System (ADS)

Kutsuki, Katsuhiro; Murakami, Yuki; Watanabe, Yukihiko; Onishi, Toru; Yamamoto, Kensaku; Fujiwara, Hirokazu; Ito, Takahiro

2018-04-01

The effects of the surface roughness of trench sidewalls on electrical properties have been investigated in 4H-SiC trench MOSFETs. The surface roughness of trench sidewalls was well controlled and evaluated by atomic force microscopy. The effective channel mobility at each measurement temperature was analyzed on the basis of the mobility model including optical phonon scattering. The results revealed that surface roughness scattering had a small contribution to channel mobility, and at the arithmetic average roughness in the range of 0.4-1.4 nm, there was no correlation between the experimental surface roughness and the surface roughness scattering mobility. On the other hand, the characteristics of the gate leakage current and constant current stress time-dependent dielectric breakdown tests demonstrated that surface morphology had great impact on the long-term reliability of gate oxides.

Deashing macroalgae biomass by pulsed electric field treatment.

PubMed

Robin, Arthur; Sack, Martin; Israel, Alvaro; Frey, Wolfgang; Müller, Georg; Golberg, Alexander

2018-05-01

Among all biomass constituents, the ashes are major hurdles for biomass processing. Ashes currently have low market value and can make a non-negligible fraction of the biomass dry weight significantly impacting its further processing by degrading equipment, lowering process yield, inhibiting reactions and decreasing products qualities. However, most of the current treatments for deashing biomass are of poor efficiency or industrial relevance. This work is the first report on the use of Pulsed Electric Field (PEF) to enhance deashing of biomass from a high ash content green marine macroalga, Ulva sp., using hydraulic pressing. By inducing cell permeabilization of the fresh biomass, PEF was able to enhance the ash extraction from 18.4% (non-treated control) to 37.4% of the total ash content in average, significantly enhancing the extraction of five of the major ash elements (K, Mg, Na, P and S) compared to pressing alone. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electron cyclotron resonance plasma production by using pulse mode microwaves and dependences of ion beam current and plasma parameters on the pulse condition

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

Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yousuke

2012-02-15

We measure the ion beam current and the plasma parameters by using the pulse mode microwave operation in the first stage of a tandem type ECRIS. The time averaged extracted ion beam current in the pulse mode operation is larger than that of the cw mode operation with the same averaged microwave power. The electron density n{sub e} in the pulse mode is higher and the electron temperature T{sub e} is lower than those of the cw mode operation. These plasma parameters are considered to cause in the increase of the ion beam current and are suitable to produce molecularmore » or cluster ions.« less

Improving the asthma disparity gap with legal advocacy? A qualitative study of patient-identified challenges to improve social and environmental factors that contribute to poorly controlled asthma.

PubMed

Harris, Drew A; Mainardi, Anne; Iyamu, Osatohamwen; Rosenthal, Marjorie S; Bruce, R Douglas; Pisani, Margaret A; Redlich, Carrie A

2017-09-05

To identify challenges that disadvantaged adults with asthma face in mitigating social and environmental factors associated with poor symptom control. Using a community-engaged approach, we partnered with a community health center in New Haven, CT to conduct in-person interviews and a written survey of asthmatic adults with poor symptom control. Using the constant comparative method, we analyzed participant interviews to establish emerging themes and identify common barriers to improved outcomes. Through a written survey utilizing clinically validated questions, we assessed information on access to medical care, asthma control, and selected social and environmental risk factors. Twenty-one patients (mean age 47, 62% female, 71% Black, 95% insured by Medicaid) participated. The average Asthma Control Test (ACT) score was 11.6. Seventy-six percent of participants were currently employed and of those, 75% reported work-related symptoms. Among participants currently in housing, 59% reported exposure to domiciliary mice and 47% to mold. We identified three themes that summarize the challenges the study participants face: 1) Lack of knowledge about home and workplace asthma triggers; 2) Lack of awareness of legal rights or resources available to mitigate adverse conditions in the home or work environment; and 3) Fear of retaliation from landlords or employers, including threats of eviction, sexual assault, and job loss. Patients with poorly controlled asthma in a disadvantaged urban northeast community identified common barriers in both the domestic and work environments that impeded attainment of symptom control. These challenges may be best addressed through legal advocacy for those most at risk.

Active management of labor

PubMed Central

Rogers, Rebecca G; Gardner, Michael O; Tool, Kevin J; Ainsley, Jeanne; Gilson, George

2000-01-01

Objective To compare the costs of a protocol of active management of labor with those of traditional labor management. Design Cost analysis of a randomized controlled trial. Methods From August 1992 to April 1996, we randomly allocated 405 women whose infants were delivered at the University of New Mexico Health Sciences Center, Albuquerque, to an active management of labor protocol that had substantially reduced the duration of labor or a control protocol. We calculated the average cost for each delivery, using both actual costs and charges. Results The average cost for women assigned to the active management protocol was $2,480.79 compared with an average cost of $2,528.61 for women in the control group (P = 0.55). For women whose infant was delivered by cesarean section, the average cost was $4,771.54 for active management of labor and $4,468.89 for the control protocol (P = 0.16). Spontaneous vaginal deliveries cost an average of $27.00 more for actively managed patients compared with the cost for the control protocol. Conclusions The reduced duration of labor by active management did not translate into significant cost savings. Overall, an average cost saving of only $47.91, or 2%, was achieved for labors that were actively managed. This reduction in cost was due to a decrease in the rate of cesarean sections in women whose labor was actively managed and not to a decreased duration of labor. PMID:10778374

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

Lentine, Anthony L.; Cox, Jonathan Albert

Methods and systems for stabilizing a resonant modulator include receiving pre-modulation and post-modulation portions of a carrier signal, determining the average power from these portions, comparing an average input power to the average output power, and operating a heater coupled to the modulator based on the comparison. One system includes a pair of input structures, one or more processing elements, a comparator, and a control element. The input structures are configured to extract pre-modulation and post-modulation portions of a carrier signal. The processing elements are configured to determine average powers from the extracted portions. The comparator is configured to comparemore » the average input power and the average output power. The control element operates a heater coupled to the modulator based on the comparison.« less

Structure formation control of foam concrete

NASA Astrophysics Data System (ADS)

Steshenko, Aleksei; Kudyakov, Aleksander; Konusheva, Viktoriya; Syrkin, Oleg

2017-01-01

The process of predetermined foam concrete structure formation is considered to be a crucial issue from the point of process control and it is currently understudied thus defining the need for additional research. One of the effective ways of structure formation control in naturally hardening foam concrete is reinforcement with dispersed fibers or introduction of plasticizers. The paper aims at studying the patterns of influence of microreinforcing and plasticizing additives on the structure and performance properties of foam concrete. Preparation of foam concrete mix has been conducted using one-step technology. The structure of modified foam concrete has been studied by means of electron microscopy. The cellular structure of foam concrete samples with the additives is homogeneous; the pores are uniformly distributed over the total volume. It has been revealed that introduction of the Neolas 5.2 plasticizer and microreinforcing fibers in the foam concrete mixture in the amount of 0.4 - 0.1 % by weight of cement leads to reduction of the average pore diameter in the range of 45.3 to 30.2 microns and the standard deviation of the pore average diameter from 23.6 to 9.2 in comparison with the sample without additive. Introduction of modifying additives has stimulated formation of a large number of closed pores. Thus porosity of conditionally closed pores has increased from 16.06 % to 34.48 %, which has lead to increase of frost resistance brand of foam concrete from F15 to F50 and to reduction of its water absorption by weight by 20 %.

Assessment of Primary Production of Horticultural Safety Management Systems of Mushroom Farms in South Africa.

PubMed

Dzingirayi, Garikayi; Korsten, Lise

2016-07-01

Growing global consumer concern over food safety in the fresh produce industry requires producers to implement necessary quality assurance systems. Varying effectiveness has been noted in how countries and food companies interpret and implement food safety standards. A diagnostic instrument (DI) for global fresh produce industries was developed to measure the compliancy of companies with implemented food safety standards. The DI is made up of indicators and descriptive grids for context factors and control and assurance activities to measure food safety output. The instrument can be used in primary production to assess food safety performance. This study applied the DI to measure food safety standard compliancy of mushroom farming in South Africa. Ten farms representing almost half of the industry farms and more than 80% of production were independently assessed for their horticultural safety management system (HSMS) compliance via in-depth interviews with each farm's quality assurance personnel. The data were processed using Microsoft Office Excel 2010 and are represented in frequency tables. The diagnosis revealed that the mushroom farming industry had an average food safety output. The farms were implementing an average-toadvanced HSMS and operating in a medium-risk context. Insufficient performance areas in HSMSs included inadequate hazard analysis and analysis of control points, low specificity of pesticide assessment, and inadequate control of suppliers and incoming materials. Recommendations to the industry and current shortcomings are suggested for realization of an improved industry-wide food safety assurance system.

Pringle's Maneuver With a Releasable Insulok Band.

PubMed

Chang, Yu-Chung

2015-10-01

Currently, there are many conventional instruments being applied to perform hepatic inflow control, the Pringle's maneuver, distal to the hepatic hilum during hepatic resections. We wondered if a commonly used Insulok band can be added. Insulok band is a plastic tying device molded in one piece with an excellent cam-lock mechanism. We have applied releasable Insulok band to the Pringle's maneuver in 10 partial hepatectomy cases, which are not suitable for application of Chang's needle. After opening the lesser omentum, the band was passed through the Winslow foramen to the lesser sac, and the portal triad was occluded by locking the band. During the intermittent reperfusion period, this Insulok band allowed easy and fast control of hepatic inflow with its simple releasable locking device. Single inflow block was used on 6 cases while repeated block on 4 cases for partial hepatectomy. The average ischemic time was 15.2 ± 8.2 minutes with an interval of 5 minutes. There was neither procedure-related morbidity nor mortality. No patient had developed postoperative hepatic failure or prolonged liver dysfunction. The efficacy of bleeding control was excellent and the average blood loss during Pringle's maneuver was 6 ± 12.6 mL. Furthermore, locking and unlocking of the Insulok band each took only 5 seconds. Releasable Insulok band is a simpler, faster, cheaper, and safe alternative to the conventional methods for blocking hepatic inflow in Pringle's maneuver, especially in those cases not suitable for using the Chang's needle. © The Author(s) 2014.

Longitudinal study of hippocampal volumes in heavy cannabis users.

PubMed

Koenders, L; Lorenzetti, V; de Haan, L; Suo, C; Vingerhoets, Wam; van den Brink, W; Wiers, R W; Meijer, C J; Machielsen, Mwj; Goudriaan, A E; Veltman, D J; Yücel, M; Cousijn, J

2017-08-01

Cannabis exposure, particularly heavy cannabis use, has been associated with neuroanatomical alterations in regions rich with cannabinoid receptors such as the hippocampus in some but not in other (mainly cross-sectional) studies. However, it remains unclear whether continued heavy cannabis use alters hippocampal volume, and whether an earlier age of onset and/or a higher dosage exacerbate these changes. Twenty heavy cannabis users (mean age 21 years, range 18-24 years) and 23 matched non-cannabis using healthy controls were submitted to a comprehensive psychological assessment and magnetic resonance imaging scan at baseline and at follow-up (average of 39 months post-baseline; standard deviation=2.4). Cannabis users started smoking around 16 years and smoked on average five days per week. A novel aspect of the current study is that hippocampal volume estimates were obtained from manual tracing the hippocampus on T1-weighted anatomical magnetic resonance imaging scans, using a previously validated protocol. Compared to controls, cannabis users did not show hippocampal volume alterations at either baseline or follow-up. Hippocampal volumes increased over time in both cannabis users and controls, following similar trajectories of increase. Cannabis dose and age of onset of cannabis use did not affect hippocampal volumes. Continued heavy cannabis use did not affect hippocampal neuroanatomical changes in early adulthood. This contrasts with prior evidence on alterations in this region in samples of older adult cannabis users. In young adults using cannabis at this level, cannabis use may not be heavy enough to affect hippocampal neuroanatomy.

Velocity control in Parkinson's disease: a quantitative analysis of isochrony in scribbling movements.

PubMed

Viviani, Paolo; Burkhard, Pierre R; Chiuvé, Sabina Catalano; Corradi-Dell'Acqua, Corrado; Vindras, Philippe

2009-04-01

An experiment was conducted to contrast the motor performance of three groups (N = 20) of participants: (1) patients with confirmed Parkinson Disease (PD) diagnose; (2) age-matched controls; (3) young adults. The task consisted of scribbling freely for 10 s within circular frames of different sizes. Comparison among groups focused on the relation between the figural elements of the trace (overall size and trace length) and the velocity of the drawing movements. Results were analysed within the framework of previous work on normal individuals showing that instantaneous velocity of drawing movements depends jointly on trace curvature (Two-thirds Power Law) and trace extent (Isochrony principle). The motor behaviour of PD patients exhibited all classical symptoms of the disease (reduced average velocity, reduced fluency, micrographia). At a coarse level of analysis both isochrony and the dependence of velocity on curvature, which are supposed to reflect cortical mechanisms, were spared in PD patients. Instead, significant differences with respects to the control groups emerged from an in-depth analysis of the velocity control suggesting that patients did not scale average velocity as effectively as controls. We factored out velocity control by distinguishing the influence of the broad context in which movement is planned--i.e. the size of the limiting frames--from the influence of the local context--i.e. the linear extent of the unit of motor action being executed. The balance between the two factors was found to be distinctively different in PD patients and controls. This difference is discussed in the light of current theorizing on the role of cortical and sub-cortical mechanisms in the aetiology of PD. We argue that the results are congruent with the notion that cortical mechanisms are responsible for generating a parametric template of the desired movement and the BG specify the actual spatio-temporal parameters through a multiplicative gain factor acting on both size and velocity.

Differential lexical and semantic spreading activation in Alzheimer's disease.

PubMed

Foster, Paul S; Drago, Valeria; Yung, Raegan C; Pearson, Jaclyn; Stringer, Kristi; Giovannetti, Tania; Libon, David; Heilman, Kenneth M

2013-08-01

Alzheimer's disease (AD) is known to be associated with disruption in semantic networks. Previous studies examining changes in spreading activation in AD have used a lexical decision task paradigm. We have used a paradigm based on average word frequencies obtained from the words generated on the Controlled Oral Word Association Test (COWAT) and the Animal Naming (AN) test. The COWAT and AN tests were administered to a group of 25 patients with AD and 20 control participants. We predicted that the patients with AD would have higher average word frequencies on the COWAT and AN tests than the control participants. The results indicated that the AD group generated words with a higher average word frequency on the AN test but a lower average word frequency on the COWAT. The reasons for the discrepancy in average word frequencies on the AN test and COWAT are discussed.

Network Performance Modeling, Design and Dimensioning Methodologies

DTIC Science & Technology

2000-01-01

Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the...failing to comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 2000 2. REPORT TYPE 3...eveEeEeveEeveEeEeveEe,eveEeveEeúèOÍ ÏReéÏ 8i RSQR R�eEeEeve,eEeveEeveEeEeveEeveEe,eveEeEeveEeveEeEeveEe,eveEeveEeúèOæ Í 6H¼2 .),576& ;D8¢;= 1 1u$B+.$0#2

Fleet Maintenance Simulation With Insufficient Data

DTIC Science & Technology

2010-03-17

Maintenance in CBM UL ddd ≤≤ UL XXX µµµ ≤≤ UL XXX σσσ ≤≤ s. t. ( ) ( )MtMcR tRtF −≤ 1 ,, Xd ( ) tLML CrtC ≤,,,, XX σµd Time S y s t e m R e l i a b i...ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for...comply with a collection of information if it does not display a currently valid OMB control number. 1 . REPORT DATE 17 MAR 2010 2. REPORT TYPE Briefing

A Climate Trend Analysis of Burkina Faso

USGS Publications Warehouse

Funk, Christopher C.; Rowland, Jim; Eilerts, Gary; Adoum, Alkhalil; White, Libby

2012-01-01

This brief report, drawing from a multi-year effort by the U.S. Agency for International Development (USAID) Famine Early Warning Systems Network (FEWS NET), examines recent trends in rainfall and air temperatures. These analyses are based on quality controlled station observations. Conclusions: * Summer rains have remained steady over the past 20 years, but remain 15 percent below the 1920-69 average. * Temperatures have increased by 0.6° Celsius since 1975, amplifying the effect of droughts. * The amount of farmland per person is low, and declining. * Burkina Faso has offset rapid population growth with improved yields. * Continued yield growth would maintain current levels of per capita food production.

A climate trend analysis of Mali

USGS Publications Warehouse

Funk, Christopher C.; Rowland, Jim; Adoum, Alkhalil; Eilerts, Gary; White, Libby

2012-01-01

This brief report, drawing from a multi-year effort by the U.S. Agency for International Development (USAID) Famine Early Warning Systems Network (FEWS NET), identifies modest declines in rainfall, accompanied by increases in air temperatures. These analyses are based on quality-controlled station observations. Conclusions: * Summer rains have remained relatively steady for the past 20 years, but are 12 percent below the 1920-1969 average. * Temperatures have increased by 0.8° Celsius since 1975, amplifying the effect of droughts. * Cereal yields are low but have been improving. * Current population and agricultural trends indicate that increased yields have offset population expansion, keeping per capita cereal production steady.

The K{sub a}-band 10-kW continuous wave gyrotron with wide-band fast frequency sweep

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

Glyavin, M.; Luchinin, A.; Morozkin, M.

2012-07-15

The dual-frequency gyrotron with fast 2% frequency sweep at about 28 GHz is designed to power an electron cyclotron resonance ion source (ECRIS). Operation with an output power of up to 10 kW in CW mode and efficiency of 20% was demonstrated at both frequencies. Frequency manipulation has a characteristic time of about 1 ms and is based on magnetic field variation with an additional low-power coil. Fast frequency sweep will supposedly increase the ion current and the average ion charge of ECRIS. The possibility of 100% power modulation is demonstrated using the same control method.

A Battery Charger and State of Charge Indicator

NASA Technical Reports Server (NTRS)

Latos, T. S.

1984-01-01

A battery charger which has a full wave rectifier in series with a transformer isolated 20 kHz dc-dc converter with high frequency switches, which are programmed to actively shape the input dc line current to be a mirror image of the ac line voltage is discussed. The power circuit operates at 2 kW peak and 1 kW average power. The BC/SCI has two major subsystems: (1) the battery charger power electronics with its controls; and (2) a microcomputer subsystem which is used to acquire battery terminal data and exercise the state of charge software programs. The state of charge definition employed is the energy remaining in the battery when extracted at a 10 kW rate divided by the energy capacity of a fully charged new battery. The battery charger circuit is an isolated boost converter operating at an internal frequency of 20 kHz. The switches selected for the battery charger are the single most important item in determining its efficiency. The combination of voltage and current requirements dictate the use of high power NPN Darlington switching transistors. The power circuit topology is a three switch design which utilizes a power FET on the center tap of the isolation transformer and the power Darlingtons on each of the two ends. An analog control system is employed to accomplish active input current waveshaping as well as the necessary regulation.

A digitally controlled AGC loop circuitry for GNSS receiver chip with a binary weighted accurate dB-linear PGA

NASA Astrophysics Data System (ADS)

Gang, Jin; Yiqi, Zhuang; Yue, Yin; Miao, Cui

2015-03-01

A novel digitally controlled automatic gain control (AGC) loop circuitry for the global navigation satellite system (GNSS) receiver chip is presented. The entire AGC loop contains a programmable gain amplifier (PGA), an AGC circuit and an analog-to-digital converter (ADC), which is implemented in a 0.18 μm complementary metal-oxide-semiconductor (CMOS) process and measured. A binary-weighted approach is proposed in the PGA to achieve wide dB-linear gain control with small gain error. With binary-weighted cascaded amplifiers for coarse gain control, and parallel binary-weighted trans-conductance amplifier array for fine gain control, the PGA can provide a 64 dB dynamic range from -4 to 60 dB in 1.14 dB gain steps with a less than 0.15 dB gain error. Based on the Gaussian noise statistic characteristic of the GNSS signal, a digital AGC circuit is also proposed with low area and fast settling. The feed-backward AGC loop occupies an area of 0.27 mm2 and settles within less than 165 μs while consuming an average current of 1.92 mA at 1.8 V.

Current conserving theory at the operator level

NASA Astrophysics Data System (ADS)

Yuan, Jiangtao; Wang, Yin; Wang, Jian

The basic assumption of quantum transport in mesoscopic systems is that the total charge inside the scattering region is zero. This means that the potential deep inside reservoirs is effectively screened and therefore the electric field at interface of scattering region is zero. Thus the current conservation condition can be satisfied automatically which is an important condition in mesoscopic transport. So far the current conserving ac theory is well developed by considering the displacement current which is due to Coulomb interaction if we just focus on the average current. However, the frequency dependent shot noise does not satisfy the conservation condition since we do not consider the current conservation at the operator level. In this work, we formulate a generalized current conserving theory at the operator level using non-equilibrium Green's function theory which could be applied to both average current and frequency dependent shot noise. A displacement operator is derived for the first time so that the frequency dependent correlation of displacement currents could be investigated. Moreover, the equilibrium shot noise is investigated and a generalized fluctuation-dissipation relationship is presented.

Autonomous vehicles' disengagements: Trends, triggers, and regulatory limitations.

PubMed

Favarò, Francesca; Eurich, Sky; Nader, Nazanin

2018-01-01

Autonomous Vehicle (AV) technology is quickly becoming a reality on US roads. Testing on public roads is currently undergoing, with many AV makers located and testing in Silicon Valley, California. The California Department of Motor Vehicles (CA DMV) currently mandates that any vehicle tested on California public roads be retrofitted to account for a back-up human driver, and that data related to disengagements of the AV technology be publicly available. Disengagements data is analyzed in this work, given the safety-critical role of AV disengagements, which require the control of the vehicle to be handed back to the human driver in a safe and timely manner. This study provides a comprehensive overview of the fragmented data obtained from AV manufacturers testing on California public roads from 2014 to 2017. Trends of disengagement reporting, associated frequencies, average mileage driven before failure, and an analysis of triggers and contributory factors are here presented. The analysis of the disengagements data also highlights several shortcomings of the current regulations. The results presented thus constitute an important starting point for improvements on the current drafts of the testing and deployment regulations for autonomous vehicles on public roads. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of internal electrode cooling on irreversible electroporation using a perfused organ model.

PubMed

O'Brien, Timothy J; Bonakdar, Mohammad; Bhonsle, Suyashree; Neal, Robert E; Aardema, Charles H; Robertson, John L; Goldberg, S Nahum; Davalos, Rafael V

2018-05-28

This study evaluates the effects of active electrode cooling, via internal fluid circulation, on the irreversible electroporation (IRE) lesion, deployed electric current and temperature changes using a perfused porcine liver model. A bipolar electrode delivered IRE electric pulses with or without activation of internal cooling to nine porcine mechanically perfused livers. Pulse schemes included a constant voltage, and a preconditioned delivery combined with an arc-mitigation algorithm. After treatment, organs were dissected, and treatment zones were stained using triphenyl-tetrazolium chloride (TTC) to demonstrate viability. Thirty-nine treatments were performed with an internally cooled applicator and 21 with a non-cooled applicator. For the constant voltage scenario, the average final electrical current measured was 26.37 and 29.20 A for the cooled and uncooled electrodes respectively ([Formula: see text]). The average final temperature measured was 33.01 and 42.43 °C for the cooled and uncooled electrodes respectively ([Formula: see text]). The average measured ablations (fixed lesion) were 3.88-by-2.08 cm and 3.86-by-2.12 cm for the cooled and uncooled electrode respectively ([Formula: see text], [Formula: see text]). Similarly, the preconditioned/arc-mitigation scenario yielded an average final electrical current measurement of a 41.07 and 47.20 A for the cooled and uncooled electrodes respectively ([Formula: see text]). The average final temperature measured was 34.93 and 44.90 °C for the cooled and uncooled electrodes respectively ([Formula: see text]). The average measured ablations (fixed lesion) were 3.67-by-2.27 cm and 3.58-by-2.09 cm for the cooled and uncooled applicators ([Formula: see text]). The internally-cooled bipolar applicator offers advantages that could improve clinical outcomes. Thermally mitigating internal perfusion technology reduced tissue temperatures and electric current while maintaining similar lesion sizes.

Quantitative Measures of Chaotic Charged Particle Dynamics in the Magnetotail

NASA Astrophysics Data System (ADS)

Holland, D. L.; Martin, R. F., Jr.; Burris, C.

2017-12-01

It has long been noted that the motion of charged particles in magnetotail-like magnetic fields is chaotic, however, efforts to quantify the degree of chaos have had conflicting conclusions. In this paper we re-examine the question by focusing on quantitative measures of chaos. We first examine the percentage of orbits that enter the chaotic region of phase space and the average trapping time of those particles. We then examine the average exponential divergence rate (AEDR) of the chaotic particles between their first and last crossing of the mid-plane. We show that at resonant energies where the underlying phase space has a high degree of symmetry, only a small number of particle enter the chaotic region, but they are trapped for long periods of time and the time asymptotic value of the AEDR is very close to the average value of the AEDR. At the off-resonant energies where the phase space is highly asymmetric, the majority of the particle enter the chaotic region for fairly short periods of time and the time asymptotic value of the AEDR is much smaller than the average value. The root cause is that in the resonant case, the longest-lived orbits tend interact with the current many times and sample the entire chaotic region, whereas in the non-resonant case the longest-lived orbits only interact with the current sheet a small number of times but have very long mirrorings where the motion is nearly regular. Additionally we use an ad-hoc model where we model the current sheet as a Lorentz scattering system with each interaction with the current sheet being considered as a "collision". We find that the average kick per collision is greatest at off-resonant energies. Finally, we propose a chaos parameter as the product of the AEDR times the average chaotic particle trapping time times the percentage of orbits that are chaotic. We find that this takes on peak values at the resonant energies.

Effect of poor control of film processors on mammographic image quality.

PubMed

Kimme-Smith, C; Sun, H; Bassett, L W; Gold, R H

1992-11-01

With the increasingly stringent standards of image quality in mammography, film processor quality control is especially important. Current methods are not sufficient for ensuring good processing. The authors used a sensitometer and densitometer system to evaluate the performance of 22 processors at 16 mammographic facilities. Standard sensitometric values of two films were established, and processor performance was assessed for variations from these standards. Developer chemistry of each processor was analyzed and correlated with its sensitometric values. Ten processors were retested, and nine were found to be out of calibration. The developer components of hydroquinone, sulfites, bromide, and alkalinity varied the most, and low concentrations of hydroquinone were associated with lower average gradients at two facilities. Use of the sensitometer and densitometer system helps identify out-of-calibration processors, but further study is needed to correlate sensitometric values with developer component values. The authors believe that present quality control would be improved if sensitometric or other tests could be used to identify developer components that are out of calibration.

Coordinated single-phase control scheme for voltage unbalance reduction in low voltage network.

PubMed

Pullaguram, Deepak; Mishra, Sukumar; Senroy, Nilanjan

2017-08-13

Low voltage (LV) distribution systems are typically unbalanced in nature due to unbalanced loading and unsymmetrical line configuration. This situation is further aggravated by single-phase power injections. A coordinated control scheme is proposed for single-phase sources, to reduce voltage unbalance. A consensus-based coordination is achieved using a multi-agent system, where each agent estimates the averaged global voltage and current magnitudes of individual phases in the LV network. These estimated values are used to modify the reference power of individual single-phase sources, to ensure system-wide balanced voltages and proper power sharing among sources connected to the same phase. Further, the high X / R ratio of the filter, used in the inverter of the single-phase source, enables control of reactive power, to minimize voltage unbalance locally. The proposed scheme is validated by simulating a LV distribution network with multiple single-phase sources subjected to various perturbations.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'. © 2017 The Author(s).

Miniaturized pulsed CO2 laser with sealed electron source

NASA Astrophysics Data System (ADS)

Bychkov, Y. I.; Orlovskiy, V. M.; Osipov, V. V.; Poteryayev, A. G.

1984-04-01

A new miniature electron beam-controlled CO2 laser (the MIG-3) contains an electron accelerator, gas cell and DC supply in one large unit (0.22 x 0,16 x 0.7 m) and the accelerator power supply and laser control panel in a second smaller unit. The overall weight of the instrument in 30 kg. The electron beam is controlled by four vacuum diodes in parallel; a 180 KV pulse is fed to the vacuum diode inputs from a "NORA" series-produced X-ray source (the MIRA-3D) also is used). The total electron beam current from all diodes was 600 A following the foil with a half-height width of 10 ns. The lasing medium is CO2:N2 - 1:1 at 4.5 atm. The maximum stimulated emission pulse energy was 1 J with an efficiency of 8% when the pressure was 4 atm. With a pulse repetition rate of 4 Hz, the average power consumption of the unit was 100 W.

The contribution from psychological, social, and organizational work factors to risk of disability retirement: a systematic review with meta-analyses.

PubMed

Knardahl, Stein; Johannessen, Håkon A; Sterud, Tom; Härmä, Mikko; Rugulies, Reiner; Seitsamo, Jorma; Borg, Vilhelm

2017-02-08

Previous studies indicate that psychological, social, and organizational factors at work contribute to health, motivation, absence from work, and functional ability. The objective of the study was to assess the current state of knowledge of the contribution of psychological, social, and organizational factors to disability retirement by a systematic review and meta-analyses. Data sources: A systematic literature search for studies of retirement due to disability in Medline, Embase, and PsychINFO was performed. Reference lists of relevant articles were hand-searched for additional studies. Internal validity was assessed independently by two referees with a detailed checklist for sources of bias. Conclusions were drawn based on studies with acceptable quality. We calculated combined effect estimates by means of averaged associations (Risk ratios) across samples, weighting observed associations by the study's sample size. Thirty-nine studies of accepted quality were found, 37 of which from the Nordic countries. There was moderate evidence for the role of low control (supported by weighted average RR = 1.40; 95% CI = 1.21-1.61) and moderate evidence for the combination of high demands and low control (although weighted average was RR = 1.45; 95% CI = 0.96-2.19) as predictors of disability retirement. There were no major systematic differences in findings between the highest rated and the lowest rated studies that passed the criterion for adequate quality. There was limited evidence for downsizing, organizational change, lack of employee development and supplementary training, repetitive work tasks, effort-reward imbalance to increase risk of disability pension. Very limited evidence was found for job demands, evening or night work, and low social support from ones superior. Psychological and organizational factors at work contribute to disability retirement with the most robust evidence for the role of work control. We recommend the measurement of specific exposure factors in future studies.

Numerical modelling assessment of climate-change impacts and mitigation measures on the Querença-Silves coastal aquifer (Algarve, Portugal)

NASA Astrophysics Data System (ADS)

Hugman, Rui; Stigter, Tibor; Costa, Luis; Monteiro, José Paulo

2017-11-01

Predicted changes in climate will lead to seawater intrusion in the Querença-Silves (QS) coastal aquifer (south Portugal) during the coming century if the current water-resource-management strategy is maintained. As for much of the Mediterranean, average rainfall is predicted to decrease along with increasing seasonal and inter-annual variability and there is a need to understand how these changes will affect the sustainable use of groundwater resources. A density-coupled flow and transport model of the QS was used to simulate an ensemble of climate, water-use and adaptation scenarios from 2010 to 2099 taking into account intra- and inter-annual variability in recharge and groundwater use. By considering several climate models, bias correction and recharge calculation methods, a degree of uncertainty was included. Changes in rainfall regimes will have an immediate effect on groundwater discharge; however, the effect on saltwater intrusion is attenuated by the freshwater-saltwater interfaces' comparatively slow rate of movement. Comparing the effects of adaptation measures demonstrates that the extent of intrusion in the QS is controlled by the long-term water budget, as the effectiveness of both demand and supply oriented measures is proportional to the change in water budget, and that to maintain the current position, average groundwater discharge should be in the order of 50 × 106 m3 yr-1.

How reliable are ligand-centric methods for Target Fishing?

NASA Astrophysics Data System (ADS)

Peon, Antonio; Dang, Cuong; Ballester, Pedro

2016-04-01

Computational methods for Target Fishing (TF), also known as Target Prediction or Polypharmacology Prediction, can be used to discover new targets for small-molecule drugs. This may result in repositioning the drug in a new indication or improving our current understanding of its efficacy and side effects. While there is a substantial body of research on TF methods, there is still a need to improve their validation, which is often limited to a small part of the available targets and not easily interpretable by the user. Here we discuss how target-centric TF methods are inherently limited by the number of targets that can possibly predict (this number is by construction much larger in ligand-centric techniques). We also propose a new benchmark to validate TF methods, which is particularly suited to analyse how predictive performance varies with the query molecule. On average over approved drugs, we estimate that only five predicted targets will have to be tested to find two true targets with submicromolar potency (a strong variability in performance is however observed). In addition, we find that an approved drug has currently an average of eight known targets, which reinforces the notion that polypharmacology is a common and strong event. Furthermore, with the assistance of a control group of randomly-selected molecules, we show that the targets of approved drugs are generally harder to predict.

Definition of temperature thresholds: the example of the French heat wave warning system.

PubMed

Pascal, Mathilde; Wagner, Vérène; Le Tertre, Alain; Laaidi, Karine; Honoré, Cyrille; Bénichou, Françoise; Beaudeau, Pascal

2013-01-01

Heat-related deaths should be somewhat preventable. In France, some prevention measures are activated when minimum and maximum temperatures averaged over three days reach city-specific thresholds. The current thresholds were computed based on a descriptive analysis of past heat waves and on local expert judgement. We tested whether a different method would confirm these thresholds. The study was set in the six cities of Paris, Lyon, Marseille, Nantes, Strasbourg and Limoges between 1973 and 2003. For each city, we estimated the excess in mortality associated with different temperature thresholds, using a generalised additive model, controlling for long-time trends, seasons and days of the week. These models were used to compute the mortality predicted by different percentiles of temperatures. The thresholds were chosen as the percentiles associated with a significant excess mortality. In all cities, there was a good correlation between current thresholds and the thresholds derived from the models, with 0°C to 3°C differences for averaged maximum temperatures. Both set of thresholds were able to anticipate the main periods of excess mortality during the summers of 1973 to 2003. A simple method relying on descriptive analysis and expert judgement is sufficient to define protective temperature thresholds and to prevent heat wave mortality. As temperatures are increasing along with the climate change and adaptation is ongoing, more research is required to understand if and when thresholds should be modified.

Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector

NASA Technical Reports Server (NTRS)

Huntington, Andrew

2013-01-01

The purpose of this program was to develop single-photon-sensitive short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode photon-counting APDs are desired for lidar because they have a shorter pixel dead time than Geiger APDs, and can detect sequential pulse returns from multiple objects that are closely spaced in range. Linear-mode APDs can also measure photon number, which Geiger APDs cannot, adding an extra dimension to lidar scene data for multi-photon returns. High-gain APDs with low multiplication noise are required for efficient linear-mode detection of single photons because of APD gain statistics -- a low-excess-noise APD will generate detectible current pulses from single photon input at a much higher rate of occurrence than will a noisy APD operated at the same average gain. MWIR and LWIR electron-avalanche HgCdTe APDs have been shown to operate in linear mode at high average avalanche gain (M > 1000) without excess multiplication noise (F = 1), and are therefore very good candidates for linear-mode photon counting. However, detectors fashioned from these narrow-bandgap alloys require aggressive cooling to control thermal dark current. Wider-bandgap SWIR HgCdTe APDs were investigated in this program as a strategy to reduce detector cooling requirements.

Effect of Electrical Current Stimulation on Pseudomonas Aeruginosa Growth

NASA Astrophysics Data System (ADS)

Alneami, Auns Q.; Khalil, Eman G.; Mohsien, Rana A.; Albeldawi, Ali F.

2018-05-01

The present study evaluates the effect of electrical current with different frequencies stimulation to kill pathogenic Pseudomonas aeruginosa (PA) bacteria in vitro using human safe level of electricity controlled by function generator. A wide range of frequencies has been used from 0.5 Hz-1.2 MHz to stimulate the bacteria at a voltage of 20 p-p volt for different periods of time (5 to 30) minutes. The culture of bacteria used Nickel, Nichrome, or Titanium electrode using agarose in phosphate buffer saline (PBS) and mixed with bacterial stock activated by trypticase soy broth (TSB). The results of frequencies between 0.5-1 KHz show the inhibition zone diameter of 20 mm in average at 30 minutes of stimulation. At frequencies between 3-60 KHz the inhibition zone diameter was only 10mm for 30 minutes of stimulation. While the average of inhibition zone diameter increased to more than 30mm for 30 minutes of stimulation at frequencies between 80-120 KHz. From this study we conclude that at specific frequency (resonance frequency) (frequencies between 0.5-1 KHz) there was relatively large inhibition zone because the inductive reactance effect is equal to the value of capacitive reactance effect (XC = XL). At frequencies over than 60 KHz, maximum inhibition zone noticed because the capacitance impedance becomes negligible (only the small resistivity of the bacterial internal organs).

Effects of Agricultural Land-Use Changes and Rainfall on Ground-Water Recharge in Central and West Maui, Hawai`i, 1926-2004

USGS Publications Warehouse

Engott, John A.; Vana, Thomas T.

2007-01-01

Concern surrounding declines in ground-water levels and an increase in the chloride concentration of water pumped from wells in the Iao aquifer system on the Island of Maui has prompted an investigation into the long-term sustainability of current (2006) and future ground-water withdrawals. As part of this investigation, a water budget for central and west Maui was calculated from which (1) ground-water recharge was estimated for the period 1926-2004 and (2) the effects of agricultural land-use changes and drought were analyzed. Estimated mean ground-water recharge decreased 44 percent from 1979 to 2004 in central and west Maui. Reduction in agricultural irrigation, resulting from more efficient irrigation methods and a reduction in the acreage used for agriculture, is largely responsible for the declining recharge. Recently, periods of lower-than-average rainfall have further reduced recharge. During the period 1926-79, ground-water recharge averaged 693 Mgal/d, irrigation averaged 437 Mgal/d, and rainfall averaged 897 Mgal/d. During the period 2000-04, ground-water recharge averaged 391 Mgal/d, irrigation averaged 237 Mgal/d, and rainfall averaged 796 Mgal/d. Simulations of hypothetical future conditions indicate that a cessation of agriculture in central and west Maui would reduce mean ground-water recharge by 18 percent in comparison with current conditions, assuming that current climatic conditions are the same as the long-term-average conditions during the period 1926-2004. A period of drought identical to that of 1998-2002 would reduce mean recharge by 27 percent. Mean recharge would decrease by 46 percent if this drought were to occur after a cessation of agriculture in central and western Maui. Whereas droughts are transient phenomena, a reduction in agricultural irrigation is likely a permanent condition.

Results of a Pilates exercise program in patients with chronic non-specific low back pain: a randomized controlled trial.

PubMed

Valenza, M C; Rodríguez-Torres, J; Cabrera-Martos, I; Díaz-Pelegrina, A; Aguilar-Ferrándiz, M E; Castellote-Caballero, Y

2017-06-01

To investigate the effects of a Pilates exercise program on disability, pain, lumbar mobility, flexibility and balance in patients with chronic non-specific low back pain. Randomized controlled trial. University laboratory. A total of 54 patients with chronic non-specific low back pain. Patients were randomly allocated to an experimental group ( n=27) included in a Pilates exercise program or to a control group ( n=27) receiving information in a form of a leaflet. Disability (Roland-Morris Disability Questionnaire and Oswestry Disability Index), current, average and pain at it least and at its worst (Visual Analogue Scales), lumbar mobility (modified Shober test), flexibility (finger-to-floor test) and balance (single limb stance test) were measured at baseline and after the intervention. A between-group analysis showed significant differences in the intervention group compared to the control group for both disability scores, the Rolland-Morris questionnaire (mean change±standard deviation of 5.31±3.37 and 2.40±6.78 respectively and between-groups mean difference of 3.2 ± 4.12, p=0.003) and the Oswestry Disability Index ( p<0.001), current pain ( p=0.002) and pain at it least ( p=0.033), flexibility (0.032) and balance (0.043). An 8-week Pilates exercise program is effective in improving disability, pain, flexibility and balance in patients with chronic non-specific low back pain.

Chronic sleep reduction is associated with academic achievement and study concentration in higher education students.

PubMed

van der Heijden, Kristiaan B; Vermeulen, Marije C M; Donjacour, Claire E H M; Gordijn, Marijke C M; Hamburger, Hans L; Meijer, Anne M; van Rijn, Karin J; Vlak, Monique; Weysen, Tim

2018-04-01

Inadequate sleep impairs cognitive function and has been associated with worse academic achievement in higher education students; however, studies that control for relevant background factors and include knowledge on sleep hygiene are scarce. This study examined the association of chronic sleep reduction (i.e. symptoms of chronic sleep reduction such as shortness of sleep, sleepiness and irritation), subjective sleep quality and sleep hygiene knowledge with academic achievement (grades and study credits) and study concentration among 1378 higher education students (71% female, mean age 21.73 years, SD = 3.22) in the Netherlands. Demographic, health, lifestyle and study behaviour characteristics were included as covariates in hierarchical regression analyses. After controlling for significant covariates, only chronic sleep reduction remained a significant predictor of lower grades (last exam, average in current academic year). Better sleep quality and sleep hygiene knowledge were associated with better academic achievement, but significance was lost after controlling for covariates, except for a remaining positive association between sleep hygiene beliefs and grades in the current academic year. Moreover, better sleep quality and lower scores on chronic sleep reduction were associated with better study concentration after controlling for significant covariates. To conclude, chronic sleep reduction is associated with academic achievement and study concentration in higher education students. Inadequate sleep hygiene knowledge is moderately associated with worse academic achievement. Future research should investigate whether sleep hygiene interventions improve academic achievement in students of higher education. © 2017 European Sleep Research Society.

The effect of longitudinal conductance variations on the ionospheric prompt penetration electric fields

NASA Astrophysics Data System (ADS)

Sazykin, S.; Wolf, R.; Spiro, R.; Fejer, B.

Ionospheric prompt penetration electric fields of magnetospheric origin, together with the atmospheric disturbance dynamo, represent the most important parameters controlling the storm-time dynamics of the low and mid-latitude ionosphere. These prompt penetration fields result from the disruption of region-2 field-aligned shielding currents during geomagnetically disturbed conditions. Penetration electric fields con- trol, to a large extent, the generation and development of equatorial spread-F plasma instabilities as well as other dynamic space weather phenomena in the ionosphere equatorward of the auroral zone. While modeling studies typically agree with average patterns of prompt penetration fields, experimental results suggest that longitudinal variations of the ionospheric con- ductivities play a non-negligible role in controlling spread-F phenomena, an effect that has not previously been modeled. We present first results of modeling prompt pene- tration electric fields using a version of the Rice Convection Model (RCM) that allows for longitudinal variations in the ionospheric conductance tensor. The RCM is a first- principles numerical ionosphere-magnetosphere coupling model that solves for the electric fields, field-aligned currents, and particle distributions in the ionosphere and inner/middle magnetosphere. We compare these new theoretical results with electric field observations.

Efficiency Analysis of a High-Specific Impulse Hall Thruster

NASA Technical Reports Server (NTRS)

Jacobson, David (Technical Monitor); Hofer, Richard R.; Gallimore, Alec D.

2004-01-01

Performance and plasma measurements of the high-specific impulse NASA-173Mv2 Hall thruster were analyzed using a phenomenological performance model that accounts for a partially-ionized plasma containing multiply-charged ions. Between discharge voltages of 300 to 900 V, the results showed that although the net decrease of efficiency due to multiply-charged ions was only 1.5 to 3.0 percent, the effects of multiply-charged ions on the ion and electron currents could not be neglected. Between 300 to 900 V, the increase of the discharge current was attributed to the increasing fraction of multiply-charged ions, while the maximum deviation of the electron current from its average value was only +5/-14 percent. These findings revealed how efficient operation at high-specific impulse was enabled through the regulation of the electron current with the applied magnetic field. Between 300 to 900 V, the voltage utilization ranged from 89 to 97 percent, the mass utilization from 86 to 90 percent, and the current utilization from 77 to 81 percent. Therefore, the anode efficiency was largely determined by the current utilization. The electron Hall parameter was nearly constant with voltage, decreasing from an average of 210 at 300 V to an average of 160 between 400 to 900 V. These results confirmed our claim that efficient operation can be achieved only over a limited range of Hall parameters.

The effect of tobacco use on outcomes of laparoscopic and open inguinal hernia repairs: a review of the NSQIP dataset.

PubMed

Landin, MacKenzie; Kubasiak, John C; Schimpke, Scott; Poirier, Jennifer; Myers, Jonathan A; Millikan, Keith W; Luu, Minh B

2017-02-01

As the effort to reduce postoperative morbidity and mortality continues, the search for modifiable patient risk factors to reduce complications is ongoing. Tobacco use is associated with impaired wound healing, but its effect on inguinal hernia repair has not been studied in a large population. An ACS-NSQIP dataset was used to evaluate the effect of tobacco use on outcomes of inguinal hernia repairs. The ACS-NSQIP dataset was queried for patients who underwent open or laparoscopic inguinal hernia repairs, by primary procedure CPT codes, between years 2009-2012. Tobacco use was registered, as defined by the ACS-NSQIP, in two ways: current smoking (within the past 12 months), or history of smoking (having ever smoked). Univariate and multivariate analyses were used to investigate outcome variables for 30-day morbidity by type of smoking status, while adjusting for preoperative risk factors. During the study period, 90,162 patients underwent inguinal hernia repair. 76 % of the cases were open compared to 24 % laparoscopic. The population was overwhelmingly male, 91 %, compared to 9 % female. The average age of patients was 42.5 years. Of the available data (69 % of patients), 38.5 % had a history of smoking. 18 % had smoked within the 12 months prior to surgery (current smokers). Their average number of pack years was 27.2 (SD 24.0) compared to 4.5 pack years (SD 14.7) for those who had not smoked 12 months prior to surgery (historical smokers). Using Fisher's exact test, having ever smoked was found to be significantly associated with pneumonia (p = 0.0008) and return to the operating room (p = 0.010). This relationship held when preoperative variables were controlled for using logistic regression (pneumonia, p = 0.002; return to the operating room, p = 0.002). When preoperative variables were controlled for and logistic regression was performed for current smokers, there was also a significant association with pneumonia (p = 0.005) and return to the operating room (p = 0.01). Current smoking status is a modifiable risk of patients undergoing laparoscopic and open inguinal hernia repair. Failure to quit smoking prior to surgical repair is associated with complications like pneumonia and return to the operating room.

Sediment losses and gains across a gradient of livestock grazing and plant invasion in a cool, semi-arid grassland, Colorado Plateau, USA

USGS Publications Warehouse

Belnap, J.; Reynolds, R.L.; Reheis, M.C.; Phillips, S.L.; Urban, F.E.; Goldstein, H.L.

2009-01-01

Large sediment fluxes can have significant impacts on ecosystems. We measured incoming and outgoing sediment across a gradient of soil disturbance (livestock grazing, plowing) and annual plant invasion for 9 years. Our sites included two currently ungrazed sites: one never grazed by livestock and dominated by perennial grasses/well-developed biocrusts and one not grazed since 1974 and dominated by annual weeds with little biocrusts. We used two currently grazed sites: one dominated by annual weeds and the other dominated by perennial plants, both with little biocrusts. Precipitation was highly variable, with years of average, above-average, and extremely low precipitation. During years with average and above-average precipitation, the disturbed sites consistently produced 2.8 times more sediment than the currently undisturbed sites. The never grazed site always produced the least sediment of all the sites. During the drought years, we observed a 5600-fold increase in sediment production from the most disturbed site (dominated by annual grasses, plowed about 50 years previously and currently grazed by livestock) relative to the never grazed site dominated by perennial grasses and well-developed biocrusts, indicating a non-linear, synergistic response to increasing disturbance types and levels. Comparing sediment losses among the sites, biocrusts were most important in predicting site stability, followed by perennial plant cover. Incoming sediment was similar among the sites, and while inputs were up to 9-fold higher at the most heavily disturbed site during drought years compared to average years, the change during the drought conditions was small relative to the large change seen in the sediment outputs. ?? 2009 Elsevier B.V. All rights reserved.

Uncertainties in Estimates of Fleet Average Fuel Economy : A Statistical Evaluation

DOT National Transportation Integrated Search

1977-01-01

Research was performed to assess the current Federal procedure for estimating the average fuel economy of each automobile manufacturer's new car fleet. Test vehicle selection and fuel economy estimation methods were characterized statistically and so...

Gallstones and gallbladder cancer-volume and weight of gallstones are associated with gallbladder cancer: a case-control study.

PubMed

Roa, Iván; Ibacache, Gilda; Roa, Juan; Araya, Juan; de Aretxabala, Xabier; Muñoz, Sergio

2006-06-15

Gallstones are considered the most important risk factor for gallbladder cancer. To identify differences in the number, weight, volume, and density of gallstones associated with chronic cholecystitis (CC), gallbladder dysplasia (GD), and gallbladder cancer (GBC). A total of 125 cases were selected, of which 93 had gallstones associated with GBC and 31 had gallstones associated with GD. The controls were those with CC, matched by sex and age. The number, weight, volume, and density of these gallstones were examined in order to determine differences and relative cancer risk. Number: Multiple gallstones were present in over 76% of cases (GBC and GD) and controls (P = ns). The average number of multiple stones was 21 in GBC versus 14 in controls (P < 0.01). Weight: The average weight of the gallstones was 9.6 g in GBC versus 6.0 g in controls (P = 0.0004). The average weight in multiple stones over 10 g had strong association with GBC (P = 0.0006). Volume: The average volume was 11.7 and 6.48 ml in GBC and controls (P = 0.0002). Average volumes of 6, 8, and 10 ml had a relative cancer risk of 5, 7, and 11 times, respectively. Size: No differences were shown between GBC, GD, and controls. The volume of gallstones associated with other risk factors of GBC may be helpful in prioritizing cholecystectomies in symptomatic patients. Copyright 2006 Wiley-Liss, Inc.

SU-D-201-04: Evaluation of Elekta Agility MLC Performance Using Statistical Process Control

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

Meyers, SM; Balderson, MJ; Letourneau, D

2016-06-15

Purpose: to evaluate the performance and stability of the Elekta Agility MLC model using an automated quality control (QC) test in combination with statistical process control tools. Methods: Leaf positions were collected daily for 11 Elekta units over 5–19 months using the automated QC test, which analyzes 23 MV images to determine the location of MLC leaves relative to the radiation isocenter. The leaf positions are measured at 5 nominal positions, and images are acquired at collimator 0° and 180° to capture all MLC leaves in the field-of-view. Leaf positioning accuracy was assessed using individual and moving range control charts.more » Control limits were recomputed following MLC recalibration (occurred 1–2 times for 4 units). Specification levels of ±0.5, ±1 and ±1.5mm were tested. The mean and range of duration between out-of-control and out-of-specification events were determined. Results: Leaf position varied little over time, as confirmed by very tight individual control limits (mean ±0.19mm, range 0.09–0.44). Mean leaf position error was −0.03mm (range −0.89–0.83). Due to sporadic out-of-control events, the mean in-control duration was 3.3 days (range 1–23). Data stayed within ±1mm specification for 205 days on average (range 3–372) and within ±1.5mm for the entire date range. Measurements stayed within ±0.5mm for 1 day on average (range 0–17); however, our MLC leaves were not calibrated to this level of accuracy. Conclusion: The Elekta Agility MLC model was found to perform with high stability, as evidenced by the tight control limits. The in-specification durations support the current recommendation of monthly MLC QC tests with a ±1mm tolerance. Future work is on-going to determine if Agility performance can be optimized further using high-frequency QC test results to drive recalibration frequency. Factors that can affect leaf positioning accuracy, including beam spot motion, leaf gain calibration, drifting leaves, and image artifacts, are under investigation.« less

Calculation of induced current densities for humans by magnetic fields from electronic article surveillance devices

NASA Astrophysics Data System (ADS)

Gandhi, Om P.; Kang, Gang

2001-11-01

This paper illustrates the use of the impedance method to calculate the electric fields and current densities induced in millimetre resolution anatomic models of the human body, namely an adult and 10- and 5-year-old children, for exposure to nonuniform magnetic fields typical of two assumed but representative electronic article surveillance (EAS) devices at 1 and 30 kHz, respectively. The devices assumed for the calculations are a solenoid type magnetic deactivator used at store checkouts and a pass-by panel-type EAS system consisting of two overlapping rectangular current-carrying coils used at entry and exit from a store. The impedance method code is modified to obtain induced current densities averaged over a cross section of 1 cm2 perpendicular to the direction of induced currents. This is done to compare the peak current densities with the limits or the basic restrictions given in the ICNIRP safety guidelines. Because of the stronger magnetic fields at lower heights for both the assumed devices, the peak 1 cm2 area-averaged current densities for the CNS tissues such as the brain and the spinal cord are increasingly larger for smaller models and are the highest for the model of the 5-year-old child. For both the EAS devices, the maximum 1 cm2 area-averaged current densities for the brain of the model of the adult are lower than the ICNIRP safety guideline, but may approach or exceed the ICNIRP basic restrictions for models of 10- and 5-year-old children if sufficiently strong magnetic fields are used.

Calculation of induced current densities for humans by magnetic fields from electronic article surveillance devices.

PubMed

Gandhi, O P; Kang, G

2001-11-01

This paper illustrates the use of the impedance method to calculate the electric fields and current densities induced in millimetre resolution anatomic models of the human body, namely an adult and 10- and 5-year-old children, for exposure to nonuniform magnetic fields typical of two assumed but representative electronic article surveillance (EAS) devices at 1 and 30 kHz, respectively. The devices assumed for the calculations are a solenoid type magnetic deactivator used at store checkouts and a pass-by panel-type EAS system consisting of two overlapping rectangular current-carrying coils used at entry and exit from a store. The impedance method code is modified to obtain induced current densities averaged over a cross section of 1 cm2 perpendicular to the direction of induced currents. This is done to compare the peak current densities with the limits or the basic restrictions given in the ICNIRP safety guidelines. Because of the stronger magnetic fields at lower heights for both the assumed devices, the peak 1 cm2 area-averaged current densities for the CNS tissues such as the brain and the spinal cord are increasingly larger for smaller models and are the highest for the model of the 5-year-old child. For both the EAS devices, the maximum 1 cm2 area-averaged current densities for the brain of the model of the adult are lower than the ICNIRP safety guideline, but may approach or exceed the ICNIRP basic restrictions for models of 10- and 5-year-old children if sufficiently strong magnetic fields are used.

Population facts that can spur women's well being.

PubMed

Harrison, P

1994-01-01

Although women's rights proposals included in the International Conference on Population and Development deserve support on their own merit, governments are more likely to increase funding for human development if the environmental and economic advantages of investing in women are spelled out. A significant negative association between income growth and population growth emerged in the 1980s. During this decade, 41 countries where population was growing more slowly demonstrated an average income growth of 1.23% per year, while average income fell by an average of 1.25% per year in 41 countries where there was more rapid population growth. In the 1965-80 period, there was no such correlation. Moreover, population control is among the most effective measures for protecting the environment. If--through female education, women's rights, maternal-child health, and family planning--the United Nations' low population projection existed in the year 2050 as opposed to the medium projection (2.2 billion higher), 4.4 million square kilometers of land would be saved and there would be 9.3 billion tones less in carbon dioxide emissions per year. This would be equivalent to halting all current deforestation and a 26% improvement in global energy improvement. Achievement of the low projection would further result in 342 million fewer cases of malnutrition than the medium projection.