Developing Empirical Lightning Cessation Forecast Guidance for the Cape Canaveral Air Force Station and Kennedy Space Center

NASA Technical Reports Server (NTRS)

Stano, Geoffrey T.; Fuelberg, Henry E.; Roeder, William P.

2010-01-01

This research addresses the 45th Weather Squadron's (45WS) need for improved guidance regarding lightning cessation at Cape Canaveral Air Force Station and Kennedy Space Center (KSC). KSC's Lightning Detection and Ranging (LDAR) network was the primary observational tool to investigate both cloud-to-ground and intracloud lightning. Five statistical and empirical schemes were created from LDAR, sounding, and radar parameters derived from 116 storms. Four of the five schemes were unsuitable for operational use since lightning advisories would be canceled prematurely, leading to safety risks to personnel. These include a correlation and regression tree analysis, three variants of multiple linear regression, event time trending, and the time delay between the greatest height of the maximum dBZ value to the last flash. These schemes failed to adequately forecast the maximum interval, the greatest time between any two flashes in the storm. The majority of storms had a maximum interval less than 10 min, which biased the schemes toward small values. Success was achieved with the percentile method (PM) by separating the maximum interval into percentiles for the 100 dependent storms.

AIR POLLUTION IN A CITY STREET

PubMed Central

Waller, R. E.; Commins, B. T.; Lawther, P. J.

1965-01-01

Measurements of the concentrations of smoke, lead, and five polycyclic hydrocarbons in the air have been made in the City of London in the middle of a busy street and at two control sites. Samples were taken only throughout the daytime hours on weekdays to enable us to assess the maximum contribution made by traffic to the pollution in the street. The results showed that during these periods the air in the middle of the street contained three times as much smoke, four times as much lead, and 1·7 times as much 3:4-benzpyrene as were present in the general atmosphere of the City of London as estimated from samples taken at the control sites. One of these sites was chosen because it was only 150 feet away from the street; analyses yielded no evidence that the traffic contributed to the pollution sampled there. Sulphur dioxide concentrations were determined in the early part of the study and the results showed that traffic appeared to add little to the background level. The concentrations of lead found were below those held to be safe by many authorities. Carbon monoxide concentrations, reported in greater detail elsewhere, sometimes reached the accepted industrial maximum allowable concentration of 100 p.p.m. PMID:14278800

40 CFR 461.35 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory...) Subpart C—Battery Wash—(Detergent)—PSNS. Pollutant or pollutant Property Maximum for any 1 Day Maximum for... Maximum for any 1 day Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English...

40 CFR 461.35 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory...) Subpart C—Battery Wash—(Detergent)—PSNS. Pollutant or pollutant Property Maximum for any 1 Day Maximum for... Maximum for any 1 day Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English...

40 CFR 461.35 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory...) Subpart C—Battery Wash—(Detergent)—PSNS. Pollutant or pollutant Property Maximum for any 1 Day Maximum for... Maximum for any 1 day Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English...

Structural contribution to the ferroelectric fatigue in lead zirconate titanate ceramics

NASA Astrophysics Data System (ADS)

Hinterstein, M.; Rouquette, J.; Haines, J.; Papet, Ph.; Glaum, J.; Knapp, M.; Eckert, J.; Hoffman, M.

2014-09-01

Many ferroelectric devices are based on doped lead zirconate titanate (PZT) ceramics with compositions near the morphotropic phase boundary (MPB), at which the relevant material's properties approach their maximum. Based on a synchrotron x-ray diffraction study of MPB PZT, bulk fatigue is unambiguously found to arise from a less effective field induced tetragonal-to-monoclinic transformation, at which the degradation of the polarization flipping is detected by a less intense and more diffuse anomaly in the atomic displacement parameter of lead. The time dependence of the ferroelectric response on a structural level down to 250 μs confirms this interpretation in the time scale of the piezolectric strain response.

Atmospherically deposited trace metals from bulk mineral concentrate port operations.

PubMed

Taylor, Mark Patrick

2015-05-15

Although metal exposures in the environment have declined over the last two decades, certain activities and locations still present a risk of harm to human health. This study examines environmental dust metal and metalloid hazards (arsenic, cadmium, lead and nickel) associated with bulk mineral transport, loading and unloading port operations in public locations and children's playgrounds in the inner city of Townsville, northern Queensland. The mean increase in lead on post-play hand wipes (965 μg/m(2)/day) across all sites was more than 10-times the mean pre-play loadings (95 μg/m(2)/day). Maximum loading values after a 10-minute play period were 3012 μg/m(2), more than seven times the goal of 400 μg/m(2) used by the Government of Western Australia (2011). Maximum daily nickel post-play hand loadings (404 μg/m(2)) were more than 26 times above the German Federal Immission Control Act 2002 annual benchmark of 15 μg/m(2)/day. Repeat sampling over the 5-day study period showed that hands and surfaces were re-contaminated daily from the deposition of metal-rich atmospheric dusts. Lead isotopic composition analysis of dust wipes ((208)Pb/(207)Pb and (206)Pb/(207)Pb) showed that surface dust lead was similar to Mount Isa type ores, which are exported through the Port of Townsville. While dust metal contaminant loadings are lower than other mining and smelting towns in Australia, they exceeded national and international benchmarks for environmental quality. The lessons from this study are clear - even where operations are considered acceptable by managing authorities, targeted assessment and monitoring can be used to evaluate whether current management practices are truly best practice. Reassessment can identify opportunities for improvement and maximum environmental and human health protection. Copyright © 2015 Elsevier B.V. All rights reserved.

Time-dependent quantum transport and power-law decay of the transient current in a nano-relay and nano-oscillator

NASA Astrophysics Data System (ADS)

Cuansing, Eduardo C.; Liang, Gengchiau

2011-10-01

Time-dependent nonequilibrium Green's functions are used to study electron transport properties in a device consisting of two linear chain leads and a time-dependent interlead coupling that is switched on non-adiabatically. We derive a numerically exact expression for the particle current and examine its characteristics as it evolves in time from the transient regime to the long-time steady-state regime. We find that just after switch-on, the current initially overshoots the expected long-time steady-state value, oscillates and decays as a power law, and eventually settles to a steady-state value consistent with the value calculated using the Landauer formula. The power-law parameters depend on the values of the applied bias voltage, the strength of the couplings, and the speed of the switch-on. In particular, the oscillating transient current decays away longer for lower bias voltages. Furthermore, the power-law decay nature of the current suggests an equivalent series resistor-inductor-capacitor circuit wherein all of the components have time-dependent properties. Such dynamical resistive, inductive, and capacitive influences are generic in nano-circuits where dynamical switches are incorporated. We also examine the characteristics of the dynamical current in a nano-oscillator modeled by introducing a sinusoidally modulated interlead coupling between the two leads. We find that the current does not strictly follow the sinusoidal form of the coupling. In particular, the maximum current does not occur during times when the leads are exactly aligned. Instead, the times when the maximum current occurs depend on the values of the bias potential, nearest-neighbor coupling, and the interlead coupling.

40 CFR 421.256 - Pretreatment standards for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for any 1 day Maximum for monthly average mg/troy ounce of gold refined electrolytically Lead 5.544 2... Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.364 0.169 Mercury 0.195 0.078... Maximum for monthly average mg/troy ounce of silver reduced in solution Lead 0.112 0.052 Mercury 0.060 0...

40 CFR 421.256 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.364 0.169 Mercury 0.195 0.078... Maximum for monthly average mg/troy ounce of silver reduced in solution Lead 0.112 0.052 Mercury 0.060 0... for any 1 day Maximum for monthly average mg/troy ounce of gold refined electrolytically Lead 5.544 2...

WRF model forecasts and their use for hydroclimate monitoring over southern South America

NASA Astrophysics Data System (ADS)

Muller, Omar; Lovino, Miguel; Berbery, E. Hugo

2017-04-01

Weather forecasting and monitoring systems based on regional models are becoming increasingly relevant for decision support in agriculture and water management. This work evaluates the predictive and monitoring capabilities of a system based on WRF model simulations at 15 km grid spacing over a domain that encompasses La Plata Basin (LPB) in southern South America, where agriculture and water resources are essential. The model's skill up to a lead-time of 7 days is evaluated with daily precipitation and 2m temperature in-situ observations. Results show high prediction performance with 7 days lead-time throughout the domain and particularly over LPB, where about 70% of rain and no-rain days are correctly predicted. The scores tend to be better over humid climates than over arid-to-semiarid climates. Compared to the arid-semiarid climate, the humid climate has a higher probability of detection and less false alarms. The ranges of the skill scores are similar to those found over the United States, suggesting that proper choice of parameterizations lead to no loss of performance of the model. Daily mean, minimum and maximum forecast temperatures are highly correlated with observations up to 7 day lead time. The best performance is for daily mean temperature, followed by minimum temperature and a slightly weaker performance for maximum temperature over arid regions. The usefulness of WRF products for hydroclimate monitoring was tested for an unprecedented drought in southern Brazil and for a slightly above normal precipitation season in northeastern Argentina. In both cases the model products reproduce the observed precipitation conditions with consistent impacts on soil moisture, evapotranspiration and runoff. This evaluation validates the model's usefulness to fore-cast weather up to one week and to monitor climate conditions in real time. The scores suggest that the forecast lead-time can be extended into week two, while bias correction methods can reduce part of the systematic errors.

Total lead concentration in new decorative enamel paints in Lebanon, Paraguay and Russia.

PubMed

Clark, C Scott; Speranskaya, Olga; Brosche, Sara; Gonzalez, Hebe; Solis, Daniela; Kodeih, Naji; Roda, Sandy; Lind, Caroline

2015-04-01

Lead concentrations in new enamel decorative paints were determined in three countries in different areas of the world where data were not previously available. The average total lead concentration of the enamel decorative paints purchased in Lebanon, Paraguay and Russia was 24,500ppm (ppm, dry weight), more than 270 times the current limit of 90ppm in Canada and in the United States. Sixty-three percent of these paints contained concentrations greater than 90ppm. Fifty-nine percent contained concentrations greater than 600ppm, the current limit in some countries. The maximum concentrations found were 236,000ppm in Lebanon, 169,000ppm in Paraguay and 52,900ppm in Russia. An average of 29% of the samples contained exceedingly high lead concentrations, >=10,000ppm. Five brands of paint were sampled in each of Lebanon and Paraguay and seven in Russia. Three colors from each brand were analyzed. For five of the six samples of the two brands in Lebanon with affiliations outside the country, the lead concentrations ranged from 1360ppm to 135,000ppm. In Lebanon the maximum concentration in the Egypt-affiliated brand (Sipes) was 135,000ppm and the maximum for the USA-affiliated brand (Dutch Boy) was 32,400ppm. Lead was not detected in any paints from the three of the four brands of paint purchased in Paraguay that had headquarters/affiliations in other countries (Brazil-Coralit), Germany (Suvinil) and USA (Novacor)). Two of the three paints from each of the other Paraguay brands contained high levels of lead with the maximum concentrations of 108,000 and 168,000ppm; one of these brands was manufactured under a license from ICI in the Netherlands. All of the paints purchased in Russia were from Russian brands and were manufactured in Russia. All three paints from one brand contained below detection levels of lead. The maximum levels of lead in the other six brands in Russia ranged from 3230 to 52,900ppm. The two brands with the highest lead concentration, TEKS and LAKRA, were produced by companies in the top three in market share.. Overall, lead concentrations were much higher in the colored paints such as red and yellow than in white paints. In each of the three countries a brand based in that country had a colored paint that either met a 90ppm limit or was close to meeting the limit-demonstrating that practical technology was available in each of these countries to produce low lead bright colored enamel decorative paints. Even though technology for producing paint without added lead existed in each of these countries, twenty-nine (29) percent of the paints analyzed contained exceedingly high concentrations (>=10,000ppm) of lead. Copyright © 2015 Elsevier Inc. All rights reserved.

Alignment of leading-edge and peak-picking time of arrival methods to obtain accurate source locations

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

Roussel-Dupre, R.; Symbalisty, E.; Fox, C.

2009-08-01

The location of a radiating source can be determined by time-tagging the arrival of the radiated signal at a network of spatially distributed sensors. The accuracy of this approach depends strongly on the particular time-tagging algorithm employed at each of the sensors. If different techniques are used across the network, then the time tags must be referenced to a common fiducial for maximum location accuracy. In this report we derive the time corrections needed to temporally align leading-edge, time-tagging techniques with peak-picking algorithms. We focus on broadband radio frequency (RF) sources, an ionospheric propagation channel, and narrowband receivers, but themore » final results can be generalized to apply to any source, propagation environment, and sensor. Our analytic results are checked against numerical simulations for a number of representative cases and agree with the specific leading-edge algorithm studied independently by Kim and Eng (1995) and Pongratz (2005 and 2007).« less

Prediction of summer maximum and minimum temperature over the central and western United States: the roles of soil moisture and sea surface temperature

USGS Publications Warehouse

Alfaro, Eric J.; Gershunov, Alexander; Cayan, Daniel R.

2006-01-01

A statistical model based on canonical correlation analysis (CCA) was used to explore climatic associations and predictability of June–August (JJA) maximum and minimum surface air temperatures (Tmax and Tmin) as well as the frequency of Tmax daily extremes (Tmax90) in the central and western United States (west of 90°W). Explanatory variables are monthly and seasonal Pacific Ocean SST (PSST) and the Climate Division Palmer Drought Severity Index (PDSI) during 1950–2001. Although there is a positive correlation between Tmax and Tmin, the two variables exhibit somewhat different patterns and dynamics. Both exhibit their lowest levels of variability in summer, but that of Tmax is greater than Tmin. The predictability of Tmax is mainly associated with local effects related to previous soil moisture conditions at short range (one month to one season), with PSST providing a secondary influence. Predictability of Tmin is more strongly influenced by large-scale (PSST) patterns, with PDSI acting as a short-range predictive influence. For both predictand variables (Tmax and Tmin), the PDSI influence falls off markedly at time leads beyond a few months, but a PSST influence remains for at least two seasons. The maximum predictive skill for JJA Tmin, Tmax, and Tmax90 is from May PSST and PDSI. Importantly, skills evaluated for various seasons and time leads undergo a seasonal cycle that has maximum levels in summer. At the seasonal time frame, summer Tmax prediction skills are greatest in the Midwest, northern and central California, Arizona, and Utah. Similar results were found for Tmax90. In contrast, Tmin skill is spread over most of the western region, except for clusters of low skill in the northern Midwest and southern Montana, Idaho, and northern Arizona.

Preliminary Cost Benefit Assessment of Systems for Detection of Hazardous Weather. Volume I,

DTIC Science & Technology

1981-07-01

not be sufficient for adequate stream flow forecasting , it has important potential for real - time flash flood warning. This was illustrated by the 1977...provide a finer spatial resolution of the gridded data. See Table 9. 42 The results of a demonstration of the real - time capabilities of a radar-man system ...detailed real time measurement capabilities and scope for quantitative forecasting is most likely to provide the degree of lead time required if maximum

40 CFR 421.75 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (g) Subpart G—Hard Lead Refining Slag Granulation. PSES Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/kkg (pounds per billion pounds) of hard lead produced Lead .000 .000 Zinc .000 .000 (h) Subpart G—Hard Lead Refining Wet Air Pollution Control. PSES Pollutant or...

40 CFR 421.75 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (g) Subpart G—Hard Lead Refining Slag Granulation. PSES Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/kkg (pounds per billion pounds) of hard lead produced Lead .000 .000 Zinc .000 .000 (h) Subpart G—Hard Lead Refining Wet Air Pollution Control. PSES Pollutant or...

Estimates of over-diagnosis of breast cancer due to population-based mammography screening in South Australia after adjustment for lead time effects.

PubMed

Beckmann, Kerri; Duffy, Stephen W; Lynch, John; Hiller, Janet; Farshid, Gelareh; Roder, David

2015-09-01

To estimate over-diagnosis due to population-based mammography screening using a lead time adjustment approach, with lead time measures based on symptomatic cancers only. Women aged 40-84 in 1989-2009 in South Australia eligible for mammography screening. Numbers of observed and expected breast cancer cases were compared, after adjustment for lead time. Lead time effects were modelled using age-specific estimates of lead time (derived from interval cancer rates and predicted background incidence, using maximum likelihood methods) and screening sensitivity, projected background breast cancer incidence rates (in the absence of screening), and proportions screened, by age and calendar year. Lead time estimates were 12, 26, 43 and 53 months, for women aged 40-49, 50-59, 60-69 and 70-79 respectively. Background incidence rates were estimated to have increased by 0.9% and 1.2% per year for invasive and all breast cancer. Over-diagnosis among women aged 40-84 was estimated at 7.9% (0.1-12.0%) for invasive cases and 12.0% (5.7-15.4%) when including ductal carcinoma in-situ (DCIS). We estimated 8% over-diagnosis for invasive breast cancer and 12% inclusive of DCIS cancers due to mammography screening among women aged 40-84. These estimates may overstate the extent of over-diagnosis if the increasing prevalence of breast cancer risk factors has led to higher background incidence than projected. © The Author(s) 2015.

Enhancing the nonlinear thermoelectric response of a correlated quantum dot in the Kondo regime by asymmetrical coupling to the leads

NASA Astrophysics Data System (ADS)

Pérez Daroca, Diego; Roura-Bas, Pablo; Aligia, Armando A.

2018-04-01

We study the low-temperature properties of the differential response of the current to a temperature gradient at finite voltage in a single-level quantum dot including electron-electron interaction, nonsymmetric couplings to the leads, and nonlinear effects. The calculated response is significantly enhanced in setups with large asymmetries between the tunnel couplings. In the investigated range of voltages and temperatures with corresponding energies up to several times the Kondo energy scale, the maximum response is enhanced nearly an order of magnitude with respect to symmetric coupling to the leads.

Coronal propagation of flare associated electrons and protons

NASA Technical Reports Server (NTRS)

Schellert, G.; Wibberenz, G.; Kunow, H.

1985-01-01

A statistical study of characteristic times and intensities of 36 solar particle events observed between 1977 and 1979 by the Kiel Cosmic Ray Experiment on board HELIOS-1 and -2 has been carried out. For approx. 0.5 MeV electrons we order the times of maximum and the absolute intensities with respect to angular distance from the parent flare. Discussion of coronal parameters in terms of Reid's model leads to typical time constants for coronal diffusion and escape.

Lack of utility of a decision support system to mitigate delays in admission from the operating room to the postanesthesia care unit.

PubMed

Ehrenfeld, Jesse M; Dexter, Franklin; Rothman, Brian S; Minton, Betty Sue; Johnson, Diane; Sandberg, Warren S; Epstein, Richard H

2013-12-01

When the phase I postanesthesia care unit (PACU) is at capacity, completed cases need to be held in the operating room (OR), causing a "PACU delay." Statistical methods based on historical data can optimize PACU staffing to achieve the least possible labor cost at a given service level. A decision support process to alert PACU charge nurses that the PACU is at or near maximum census might be effective in lessening the incidence of delays and reducing over-utilized OR time, but only if alerts are timely (i.e., neither too late nor too early to act upon) and the PACU slot can be cleared quickly. We evaluated the maximum potential benefit of such a system, using assumptions deliberately biased toward showing utility. We extracted 3 years of electronic PACU data from a tertiary care medical center. At this hospital, PACU admissions were limited by neither inadequate PACU staffing nor insufficient PACU beds. We developed a model decision support system that simulated alerts to the PACU charge nurse. PACU census levels were reconstructed from the data at a 1-minute level of resolution and used to evaluate if subsequent delays would have been prevented by such alerts. The model assumed there was always a patient ready for discharge and an available hospital bed. The time from each alert until the maximum census was exceeded ("alert lead time") was determined. Alerts were judged to have utility if the alert lead time fell between various intervals from 15 or 30 minutes to 60, 75, or 90 minutes after triggering. In addition, utility for reducing over-utilized OR time was assessed using the model by determining if 2 patients arrived from 5 to 15 minutes of each other when the PACU census was at 1 patient less than the maximum census. At most, 23% of alerts arrived 30 to 60 minutes prior to the admission that resulted in the PACU exceeding the specified maximum capacity. When the notification window was extended to 15 to 90 minutes, the maximum utility was <50%. At most, 45% of alerts potentially would have resulted in reassigning the last available PACU slot to 1 OR versus another within 15 minutes of the original assignment. Despite multiple biases that favored effectiveness, the maximum potential benefit of a decision support system to mitigate PACU delays on the day on the surgery was below the 70% minimum threshold for utility of automated decision support messages, previously established via meta-analysis. Neither reduction in PACU delays nor reassigning promised PACU slots based on reducing over-utilized OR time were realized sufficiently to warrant further development of the system. Based on these results, the only evidence-based method of reducing PACU delays is to adjust PACU staffing and staff scheduling using computational algorithms to match the historical workload (e.g., as developed in 2001).

40 CFR 461.34 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory § 461.34... 0.008 0.004 (4) Subpart C—Battery Wash—(Detergent)—PSES. Pollutant or pollutant Property Maximum for... property Maximum for any 1 day Maximum for monthly average Metric units—mg/kg of lead in trucked batteries...

40 CFR 461.34 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory § 461.34... 0.008 0.004 (4) Subpart C—Battery Wash—(Detergent)—PSES. Pollutant or pollutant Property Maximum for... property Maximum for any 1 day Maximum for monthly average Metric units—mg/kg of lead in trucked batteries...

Compositional investigation of ∼2 μm luminescence of Ho{sup 3+}-doped lead silicate glass

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

Liu, Xueqiang; Huang, Feifei; Gao, Song

2015-11-15

Graphical abstract: Ho{sup 3+}-doped lead silicate glass with lowest maximum phonon energy possesses highest ∼2 μm luminescence intensity. - Highlights: • With increment of lead oxide, maximum phonon energy in lead silicate glass decreased. • ∼2 μm luminescent intensity of Ho{sup 3+} increased with increment of lead oxide. • Lowest lead oxide content glass possesses highest quantum efficiency due to low maximum phonon energy. - Abstract: Lead silicate glass samples with varying lead oxide content were prepared in this study, and their luminescent properties were examined and analyzed. It was found that with increasing lead oxide content, the maximum phononmore » energies of the glass samples decreased, while their spontaneous transition probabilities first increased and then decreased. The influence of the spontaneous transition rate, A{sub 10}, and the multi-phonon relaxation rate, W{sub 10}, on the sample luminescent properties was analyzed using rate equations. As a result, it was found that with increasing lead oxide content, W{sub 10}/A{sub 10} decreased, while the quantum efficiency increased. Thus, the luminescent intensity at ∼2 μm increased in the glass samples with increased lead oxide content. The high luminescent intensity and long lifetime indicate that silicate glasses containing high levels of lead oxide could potentially be used in ∼2 μm lasers.« less

[Space-time water monitoring system at the Iriklinsk hydroelectric power station].

PubMed

Deriabin, D G; Poliakov, E G; Priakhina, A A; Karimov, I F

2002-01-01

The Microbiosensor B 17677 F test system was applied to make a space-time monitoring of the biotoxicity of water used for production and everyday purposes at the Iriklinsk hydroelectric power station (IHEPS) and to identify the leading causes determining the biotoxicity of tested samples. There were seasonal variations in the biotoxicity with the maximum in spring and with minimum in winter and spring and a relationship of the spring rise in the biotoxicity to water pH changes. There was also an association of the certain values of the biotoxicity of industrial water with the concentration of petroleum products that are major pollutants at the IHEPS. The datum points that characterize the maximum level of technogenic exposure were identified.

Low-Speed Wind-Tunnel Investigation of Blowing Boundary-Layer Control on Leading- and Trailing-Edge Flaps of a Large-Scale, Low-Aspect-Ratio, 45 Swept-wing Airplane Configuration

NASA Technical Reports Server (NTRS)

Maki, Ralph L.

1959-01-01

Blowing boundary-layer control was applied to the leading- and trailing-edge flaps of a 45 deg sweptback-wing complete model in a full-scale low-speed wind-tunnel study. The principal purpose of the study was to determine the effects of leading-edge flap deflection and boundary-layer control on maximum lift and longitudinal stability. Leading-edge flap deflection alone was sufficient to maintain static longitudinal stability without trailing-edge flaps. However, leading-edge flap blowing was required to maintain longitudinal stability by delaying leading-edge flow separation when trailing-edge flaps were deflected either with or without blowing. Partial-span leading-edge flaps deflected 60 deg with moderate blowing gave the major increase in maximum lift, although higher deflection and additional blowing gave some further increase. Inboard of 0.4 semispan leading-edge flap deflection could be reduced to 40 deg and/or blowing could be omitted with only small loss in maximum lift. Trailing-edge flap lift increments were increased by boundary-layer control for deflections greater than 45 deg. Maximum lift was not increased with deflected trailing-edge flaps with blowing.

75 FR 20111 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-16

... the ``three heating products'') must be designed to ``achieve the maximum improvement in energy... and CO 2 savings are performed with different computer models, leading to different time frames for... of EPCA sets forth a variety of provisions designed to improve energy efficiency. Part A\\1\\ of Title...

High titer oncolytic measles virus production process by integration of dielectric spectroscopy as online monitoring system.

PubMed

Grein, Tanja A; Loewe, Daniel; Dieken, Hauke; Salzig, Denise; Weidner, Tobias; Czermak, Peter

2018-05-01

Oncolytic viruses offer new hope to millions of patients with incurable cancer. One promising class of oncolytic viruses is Measles virus, but its broad administration to cancer patients is currently hampered by the inability to produce the large amounts of virus needed for treatment (10 10 -10 12 virus particles per dose). Measles virus is unstable, leading to very low virus titers during production. The time of infection and time of harvest are therefore critical parameters in a Measles virus production process, and their optimization requires an accurate online monitoring system. We integrated a probe based on dielectric spectroscopy (DS) into a stirred tank reactor to characterize the Measles virus production process in adherent growing Vero cells. We found that DS could be used to monitor cell adhesion on the microcarrier and that the optimal virus harvest time correlated with the global maximum permittivity signal. In 16 independent bioreactor runs, the maximum Measles virus titer was achieved approximately 40 hr after the permittivity maximum. Compared to an uncontrolled Measles virus production process, the integration of DS increased the maximum virus concentration by more than three orders of magnitude. This was sufficient to achieve an active Measles virus concentration of > 10 10 TCID 50 ml -1 . © 2017 Wiley Periodicals, Inc.

Better Decomposition Heuristics for the Maximum-Weight Connected Graph Problem Using Betweenness Centrality

NASA Astrophysics Data System (ADS)

Yamamoto, Takanori; Bannai, Hideo; Nagasaki, Masao; Miyano, Satoru

We present new decomposition heuristics for finding the optimal solution for the maximum-weight connected graph problem, which is known to be NP-hard. Previous optimal algorithms for solving the problem decompose the input graph into subgraphs using heuristics based on node degree. We propose new heuristics based on betweenness centrality measures, and show through computational experiments that our new heuristics tend to reduce the number of subgraphs in the decomposition, and therefore could lead to the reduction in computational time for finding the optimal solution. The method is further applied to analysis of biological pathway data.

Flux rates of atmospheric lead pollution within soils of a small catchment in northern Sweden and their implications for future stream water quality.

PubMed

Klaminder, Jonatan; Bindler, Richard; Laudon, Hjalmar; Bishop, Kevin; Emteryd, Ove; Renberg, Ingemar

2006-08-01

It is not well-known how the accumulated pool of atmospheric lead pollution in the boreal forest soil will affect the groundwater and surface water chemistry in the future as this lead migrates through the soil profile. This study uses stable lead isotopes (206Pb/207Pb and 208Pb/ 207Pb ratios) to trace the transport of atmospheric lead pollution within the soil of a small catchment and predict future lead level changes in a stream draining the catchment. Low 206Pb/207Pb and 208Pb/207Pb ratios for the lead in the soil water (1.16 +/- 0.02; 2.43 +/- 0.03) and streamwater (1.18 +/- 0.03; 2.42 +/- 0.03) in comparison to that of the mineral soil (>1.4; >2.5) suggest that atmospheric pollution contributes by about 90% (65-100%) to the lead pool found in these matrixes. Calculated transport rates of atmospheric lead along a soil transect indicate that the mean residence time of lead in organic and mineral soil layers is at a centennial to millennial time scale. A maximum release of the present pool of lead pollution in the soil to the stream is predicted to occur within 200-800 years. Even though the uncertainty of the prediction is large, it emphasizes the magnitude of the time lag between the accumulation of atmospheric lead pollution in soils and the subsequent response in streamwater quality.

Incorporation of Pr into LuAG ceramics

NASA Astrophysics Data System (ADS)

Marchewka, M. R.; Chapman, M. G.; Qian, H.; Jacobsohn, L. G.

2017-06-01

An investigation of the effects of Pr in (Lu1-xPrx)3Al5O12 (LuAG:Pr) ceramics was carried out by means of x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX), and attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR) measurements coupled with luminescence measurements. It was found that the Pr concentration that maximizes luminescence emission depends on the thermal processing conditions. While the calcined LuAG:Pr powder showed maximum luminescence emission for Pr concentrations between 0.18 and 0.33 at.%, maximum emission of ceramic bodies sintered at 1500 °C for 20 h was obtained with Pr concentrations between 0.018 and 0.18 at.%. Further, for short sintering times up to about 3 h, luminescence emission intensity is maximum for Pr concentrations around 0.33 at.%. Longer sintering times lead to the formation of PrAlO3 as a secondary phase, concomitant with a reduction of the intensity of luminescence emission.

Lead recovery from waste CRT funnel glass by high-temperature melting process.

PubMed

Hu, Biao; Hui, Wenlong

2018-02-05

In this research, a novel and effective process for waste CRT funnel glass treatment was developed. The key to this process is removal of lead from the CRT funnel glass by high-temperature melting process. Sodium carbonate powder was used as a fusion agent, sodium sulfide serves as a catalytic agent and carbon powder acts as reducing agent. Experimental results showed that lead recovery rate increased with an increase in the amount of added sodium carbonate, sodium sulfide, carbonate, temperature and holding time initially, and then reached a stable value. The maximum lead recovery rate was approximately 94%, when the optimum adding amount of sodium carbonate, sodium sulfide, carbonate, temperature and holding time were 25%, 8%, 3.6%, 1200°C and 120min, respectively. In the high-temperature melting process, lead silicate in the funnel glass was firstly reduced, and then removed. The glass slag can be made into sodium and potassium silicate by hydrolysis process. This study proposed a practical and economical process for recovery of lead and utilization of waste glass slag. Copyright © 2017 Elsevier B.V. All rights reserved.

Ideal evolution of magnetohydrodynamic turbulence when imposing Taylor-Green symmetries.

PubMed

Brachet, M E; Bustamante, M D; Krstulovic, G; Mininni, P D; Pouquet, A; Rosenberg, D

2013-01-01

We investigate the ideal and incompressible magnetohydrodynamic (MHD) equations in three space dimensions for the development of potentially singular structures. The methodology consists in implementing the fourfold symmetries of the Taylor-Green vortex generalized to MHD, leading to substantial computer time and memory savings at a given resolution; we also use a regridding method that allows for lower-resolution runs at early times, with no loss of spectral accuracy. One magnetic configuration is examined at an equivalent resolution of 6144(3) points and three different configurations on grids of 4096(3) points. At the highest resolution, two different current and vorticity sheet systems are found to collide, producing two successive accelerations in the development of small scales. At the latest time, a convergence of magnetic field lines to the location of maximum current is probably leading locally to a strong bending and directional variability of such lines. A novel analytical method, based on sharp analysis inequalities, is used to assess the validity of the finite-time singularity scenario. This method allows one to rule out spurious singularities by evaluating the rate at which the logarithmic decrement of the analyticity-strip method goes to zero. The result is that the finite-time singularity scenario cannot be ruled out, and the singularity time could be somewhere between t=2.33 and t=2.70. More robust conclusions will require higher resolution runs and grid-point interpolation measurements of maximum current and vorticity.

Seasonal prediction of Indian summer monsoon rainfall in NCEP CFSv2: forecast and predictability error

NASA Astrophysics Data System (ADS)

Pokhrel, Samir; Saha, Subodh Kumar; Dhakate, Ashish; Rahman, Hasibur; Chaudhari, Hemantkumar S.; Salunke, Kiran; Hazra, Anupam; Sujith, K.; Sikka, D. R.

2016-04-01

A detailed analysis of sensitivity to the initial condition for the simulation of the Indian summer monsoon using retrospective forecast by the latest version of the Climate Forecast System version-2 (CFSv2) is carried out. This study primarily focuses on the tropical region of Indian and Pacific Ocean basin, with special emphasis on the Indian land region. The simulated seasonal mean and the inter-annual standard deviations of rainfall, upper and lower level atmospheric circulations and Sea Surface Temperature (SST) tend to be more skillful as the lead forecast time decreases (5 month lead to 0 month lead time i.e. L5-L0). In general spatial correlation (bias) increases (decreases) as forecast lead time decreases. This is further substantiated by their averaged value over the selected study regions over the Indian and Pacific Ocean basins. The tendency of increase (decrease) of model bias with increasing (decreasing) forecast lead time also indicates the dynamical drift of the model. Large scale lower level circulation (850 hPa) shows enhancement of anomalous westerlies (easterlies) over the tropical region of the Indian Ocean (Western Pacific Ocean), which indicates the enhancement of model error with the decrease in lead time. At the upper level circulation (200 hPa) biases in both tropical easterly jet and subtropical westerlies jet tend to decrease as the lead time decreases. Despite enhancement of the prediction skill, mean SST bias seems to be insensitive to the initialization. All these biases are significant and together they make CFSv2 vulnerable to seasonal uncertainties in all the lead times. Overall the zeroth lead (L0) seems to have the best skill, however, in case of Indian summer monsoon rainfall (ISMR), the 3 month lead forecast time (L3) has the maximum ISMR prediction skill. This is valid using different independent datasets, wherein these maximum skill scores are 0.64, 0.42 and 0.57 with respect to the Global Precipitation Climatology Project, CPC Merged Analysis of Precipitation and the India Meteorological Department precipitation dataset respectively for L3. Despite significant El-Niño Southern Oscillation (ENSO) spring predictability barrier at L3, the ISMR skill score is highest at L3. Further, large scale zonal wind shear (Webster-Yang index) and SST over Niño3.4 region is best at L1 and L0. This implies that predictability aspect of ISMR is controlled by factors other than ENSO and Indian Ocean Dipole. Also, the model error (forecast error) outruns the error acquired by the inadequacies in the initial conditions (predictability error). Thus model deficiency is having more serious consequences as compared to the initial condition error for the seasonal forecast. All the model parameters show the increase in the predictability error as the lead decreases over the equatorial eastern Pacific basin and peaks at L2, then it further decreases. The dynamical consistency of both the forecast and the predictability error among all the variables indicates that these biases are purely systematic in nature and improvement of the physical processes in the CFSv2 may enhance the overall predictability.

The effect of the OSHA lead exposure in construction standard on blood lead levels among iron workers employed in bridge rehabilitation.

PubMed

Levin, S M; Goldberg, M; Doucette, J T

1997-03-01

Over 50,000 workers are at risk of occupational exposure to lead in the course of renovating the nation's deteriorating infrastructure. In mid-1993, to control exposure to lead in the construction setting OSHA promulgated a Lead in Construction Standard. In this study, we assessed the effect of the mandated changes in exposure conditions which followed the introduction of this new standard. We analyzed changes in baseline and maximum blood lead concentrations and in maximum increments in blood lead levels before and after introduction of the standard among iron workers employed in the renovation of a large, lead-painted, steel bridge in New York City. Results indicated that baseline and maximum blood lead levels fell significantly after the implementation of the provisions of the standard, as did maximum increments in blood lead concentrations. Seventy-six percent of the workers maintained blood lead concentrations below 20 micrograms/dl after the OSHA standard, as compared with 66% prior to its implementation. Increments of 20 micrograms/dl or more occurred considerably more frequently before introduction of the standard (13% before vs. 4% after; p = 0.01). Evidence of decreased exposure to lead was observed among iron workers who were present both before and after the introduction of the OSHA standard, as well as among iron workers newly hired after the OSHA provisions were put in place. These findings document the effectiveness of the OSHA construction lead standard in controlling exposure to lead in this complex and variable environment. The data indicate the utility of blood lead determinations in assessing the outcome of industrial hygiene interventions to reduce exposures to lead in the construction setting.

Removal of Lead Hydroxides Complexes from Solutions Formed in Silver/Gold: Cyanidation Process

NASA Astrophysics Data System (ADS)

Parga, José R.; Martinez, Raul Flores; Moreno, Hector; Gomes, Andrew Jewel; Cocke, David L.

2014-04-01

The presence of lead hydroxides in "pregnant cyanide solution" decreases the quality of the Dore obtained in the recovery processes of gold and silver, so it is convenient to remove them. The adsorbent capacity of the low cost cow bone powder was investigated for the removal of lead ions from a solution of lead hydroxide complexes at different initial metal ion concentrations (10 to 50 mg/L), and reaction time. Experiments were carried out in batches. The maximum sorption capacity of lead determined by the Langmuir model was found to be 126.58 mg/g, and the separation factor R L was between 0 and 1, indicating a significant affinity of bone for lead. Experimental data follow pseudo-second order kinetics suggesting chemisorption. It is concluded that cow bone powder can be successfully used for the removal of lead ions, and improves the quality of the silver-gold cyanides precipitate.

Multiple Maximum Exposure Rates in Computerized Adaptive Testing

ERIC Educational Resources Information Center

Ramon Barrada, Juan; Veldkamp, Bernard P.; Olea, Julio

2009-01-01

Computerized adaptive testing is subject to security problems, as the item bank content remains operative over long periods and administration time is flexible for examinees. Spreading the content of a part of the item bank could lead to an overestimation of the examinees' trait level. The most common way of reducing this risk is to impose a…

Effects of intensive forest management practices on insect infestation levels and loblolly pine growth

Treesearch

John T. Nowak; C. Wayne Berisford

2000-01-01

Intensive forest management practices have been shown to increase tree growth and shorten rotation time. However, they may also lead to an increased need for insect pest management because of higher infestation levels and lower action thresholds. To investigate the relationship between intensive management practices arid insect infestation, maximum growth potential...

A real-time laser feedback control method for the three-wave laser source used in the polarimeter-interferometer diagnostic on Joint-TEXT tokamak

NASA Astrophysics Data System (ADS)

Xiong, C. Y.; Chen, J.; Li, Q.; Liu, Y.; Gao, L.

2014-12-01

A three-wave laser polarimeter-interferometer, equipped with three independent far-infrared laser sources, has been developed on Joint-TEXT (J-TEXT) tokamak. The diagnostic system is capable of high-resolution temporal and phase measurement of the Faraday angle and line-integrated density. However, for long-term operation (>10 min), the free-running lasers can lead to large drifts of the intermediate frequencies (˜100-˜500 kHz/10 min) and decay of laser power (˜10%-˜20%/10 min), which act to degrade diagnostic performance. In addition, these effects lead to increased maintenance cost and limit measurement applicability to long pulse/steady state experiments. To solve this problem, a real-time feedback control method of the laser source is proposed. By accurately controlling the length of each laser cavity, both the intermediate frequencies and laser power can be simultaneously controlled: the intermediate frequencies are controlled according to the pre-set values, while the laser powers are maintained at an optimal level. Based on this approach, a real-time feedback control system has been developed and applied on J-TEXT polarimeter-interferometer. Long-term (theoretically no time limit) feedback of intermediate frequencies (maximum change less than ±12 kHz) and laser powers (maximum relative power change less than ±7%) has been successfully achieved.

A real-time laser feedback control method for the three-wave laser source used in the polarimeter-interferometer diagnostic on Joint-TEXT tokamak.

PubMed

Xiong, C Y; Chen, J; Li, Q; Liu, Y; Gao, L

2014-12-01

A three-wave laser polarimeter-interferometer, equipped with three independent far-infrared laser sources, has been developed on Joint-TEXT (J-TEXT) tokamak. The diagnostic system is capable of high-resolution temporal and phase measurement of the Faraday angle and line-integrated density. However, for long-term operation (>10 min), the free-running lasers can lead to large drifts of the intermediate frequencies (∼100-∼500 kHz/10 min) and decay of laser power (∼10%-∼20%/10 min), which act to degrade diagnostic performance. In addition, these effects lead to increased maintenance cost and limit measurement applicability to long pulse/steady state experiments. To solve this problem, a real-time feedback control method of the laser source is proposed. By accurately controlling the length of each laser cavity, both the intermediate frequencies and laser power can be simultaneously controlled: the intermediate frequencies are controlled according to the pre-set values, while the laser powers are maintained at an optimal level. Based on this approach, a real-time feedback control system has been developed and applied on J-TEXT polarimeter-interferometer. Long-term (theoretically no time limit) feedback of intermediate frequencies (maximum change less than ±12 kHz) and laser powers (maximum relative power change less than ±7%) has been successfully achieved.

Biosorption characteristic of Alcaligenes sp. BAPb.1 for removal of lead(II) from aqueous solution.

PubMed

Jin, Yu; Yu, Sumei; Teng, Chunying; Song, Tao; Dong, Liying; Liang, Jinsong; Bai, Xin; Xu, Xiuhong; Qu, Juanjuan

2017-06-01

In this study, strain BAPb.1 was isolated from lead mining area and used as an adsorbent to remove lead(II) ions from aqueous solution. The physicochemical characteristics, heavy metal resistance and antibiotic sensitivity of strain BAPb.1 were investigated. Biosorption capacity was evaluated by batch biosorption experiments, and isothermal characteristics were discussed. Atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectrometry (FTIR) were conducted to explore the mechanism for lead(II) adsorption. Based on morphological and physiological characteristics as well as the phylogenetic analysis of 16S rDNA sequences, strain BAPb.1 was identified as a member of the genus Alcaligenes. It exhibited high resistances to multiple heavy metals such as lead(II), copper(II), zinc(II), nickel(II) and chromium(VI), and to antibiotics such as kanamycin, ampicillin, streptomycin, chloramphenicol, and tetracycline. The optimum conditions for maximum biosorption rate of 85.2% and maximum capacity of 56.8 mg g -1 were found at pH of 5, adsorbent dosage of 1.5 g L -1 (dry weight), initial lead(II) concentration of 100 mg L -1 , and contact time of 30 min at 30 °C. Biosorption isotherms were well fitted with Langmuir isotherm model. Mechanism analysis reveals that the lead(II) ions may exchange with sodium and potassium ions, and the hydroxyl, carbonyl and phosphate groups on the cell surface can chelate the lead(II) ions, therefore, surface adsorption play significant role in the biosorption process.

40 CFR 421.113 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Maximum for monthly average mg/kg (pounds per million pounds) of concentrate digested Lead .174 .081 Zinc... monthly average mg/Kg (pounds per million pounds) of concentrate digested Lead 2.592 1.203 Zinc 9.442 3... Maximum for monthly average mg/kg (pounds per million pounds) of concentrate digested Lead .069 .032 Zinc...

40 CFR 421.113 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Maximum for monthly average mg/kg (pounds per million pounds) of concentrate digested Lead .174 .081 Zinc... monthly average mg/Kg (pounds per million pounds) of concentrate digested Lead 2.592 1.203 Zinc 9.442 3... Maximum for monthly average mg/kg (pounds per million pounds) of concentrate digested Lead .069 .032 Zinc...

Lead recovery and the feasibility of foam glass production from funnel glass of dismantled cathode ray tube through pyrovacuum process.

PubMed

Chen, Mengjun; Zhang, Fu-Shen; Zhu, Jianxin

2009-01-30

Cathode ray tube (CRT) is the first and foremost problem that must be solved in electronic waste disposal, and the key of which lies in the detoxification and reutilization of lead-contained funnel glass. In this study, a novel and effective process for funnel glass of dismantled CRT treatment was developed. The key point of the process was to recover metallic lead from the funnel glass and to prepare foam glass synchronously. Experimental results showed that lead recovery rate increased first with the increase of temperature, carbon adding amount, and holding time, then reached a plateau value, but pressure was on the contrary. The optimum temperature, pressure, carbon adding amount and holding time for lead recovery were 1000 degrees C, 1000 Pa, 5% and 4h, respectively, and the maximum lead recovery rate was 98.6%. In the pyrovacuum process, lead in the funnel glass was firstly detached and changed to PbO, then reduced and evaporated, and was recovered in the form of pure metal with a purity of 99.3%. The residue porous glass was environmentally acceptable for construction application.

Durability of implanted electrodes and leads in an upper-limb neuroprosthesis.

PubMed

Kilgore, Kevin L; Peckham, P Hunter; Keith, Michael W; Montague, Fred W; Hart, Ronald L; Gazdik, Martha M; Bryden, Anne M; Snyder, Scott A; Stage, Thomas G

2003-01-01

Implanted neuroprosthetic systems have been successfully used to provide upper-limb function for over 16 years. A critical aspect of these implanted systems is the safety, stability, and-reliability of the stimulating electrodes and leads. These components are (1) the stimulating electrode itself, (2) the electrode lead, and (3) the lead-to-device connector. A failure in any of these components causes the direct loss of the capability to activate a muscle consistently, usually resulting in a decrement in the function provided by the neuroprosthesis. Our results indicate that the electrode, lead, and connector system are extremely durable. We analyzed 238 electrodes that have been implanted as part of an upper-limb neuroprosthesis. Each electrode had been implanted at least 3 years, with a maximum implantation time of over 16 years. Only three electrode-lead failures and one electrode infection occurred, for a survival rate of almost 99 percent. Electrode threshold measurements indicate that the electrode response is stable over time, with no evidence of electrode migration or continual encapsulation in any of the electrodes studied. These results have an impact on the design of implantable neuroprosthetic systems. The electrode-lead component of these systems should no longer be considered a weak technological link.

Evaluation of zraP gene expression characteristics and construction of a lead (Pb) sensing and removal system in a recombinant Escherichia coli.

PubMed

Maruthamuthu, Murali Kannan; Ganesh, Irisappan; Ravikumar, Sambandam; Hong, Soon Ho

2015-03-01

A ZraP-based lead sensing and removal system was constructed in E. coli. It was regulated by the ZraS/ZraR two-component system. The expression profile of the zraP gene towards extracellular lead was studied via real-time PCR. A dual-function bacterial system was also designed to express GFP and OmpC-lead binding peptide under the control of zraP for the simultaneous sensing and adsorption of environmental lead without additional manipulation. The constructed bacterial system can emit fluorescence and it adsorbed a maximum of 487 µmol lead/g cell DCW. From a study of artificial wastewater, the constructed bacteria adsorbed lead highly selectively (427 µmol lead/g cell DCW) among other metal ions. The newly-constructed dual function bacterial system can be applied for the development of an efficient process for the removal of lead from polluted wastes.

Isolation, identification, Pb(II) biosorption isotherms and kinetics of a lead adsorbing penicillium sp. MRF-1 from South Korean mine soil.

PubMed

Velmurugan, Natarajan; Hwang, Grim; Sathishkumar, Muthuswamy; Choi, Tae Kie; Lee, Kui-Jae; Oh, Byung-Taek; Lee, Yang-Soo

2010-01-01

A heavy metal contaminated soil sample collected from a mine in Chonnam Province of South Korea was found to be a source of heavy metal adsorbing biosorbents. Chemical analyses showed high contents of lead (Pb) at 357 mg/kg and cyanide (CN) at 14.6 mg/kg in the soil. The experimental results showed that Penicillium sp. MRF-1 was the best lead resistant fungus among the four individual metal tolerant fungal species isolated from the soil. Molecular characterization of Penicillium sp. MRF-1 was determined using ITS regions sequences. Effects of pH, temperature and contact time on adsorption of Pb(II) by Penicillium sp. MRF-1 were studied. Favorable conditions for maximum biosportion were found at pH 4 with 3 hr contact time. Biosorption of Pb(II) gradually increased with increasing temperature. Efficient performance of the biosorbent was described using Langmuir and Freundlich isotherms. Adsorption kinetics was studied using pseudo first-order and pseudo second-order models. Biosorbent Penicillium sp. MRF-1 showed the maximum desorption in alkali conditions. Consistent adsorption/desorption potential of the biosorbent in repetitive cycles validated the efficacy of it in large scale. SEM studies given notes on surface modification of fungal biomass under metal stress and FT-IR results showed the presence of amino groups in the surface structure of the biosorbent. In conclusion, the new biosorbent Penicillium sp. MRF-1 may potentially be used as an inexpensive, easily cultivatable material for the removal of lead from aqueous solution.

Fruit stones from industrial waste for the removal of lead ions from polluted water.

PubMed

Rashed, M N

2006-08-01

Lead, one of the earliest metals recognized and used by humans, has a long history of beneficial use. However, it is now recognized as toxic and as posing a widespread threat to humans and wildlife. Treatment of lead from polluted water and wastewater has received a great deal of attention. Adsorption is one of the most common technologies for the treatment of lead-polluted water. This technique was evaluated here, with the goal of identifying innovative, low-cost adsorbent. This study presents experiments undertaken to determine the suitable conditions for the use of peach and apricot stones, produced from food industries as solid waste, as adsorbents for the removal of lead from aqueous solution. Chemical stability of adsorbents, effect of pH, adsorbents dose, adsorption time and equilibrium concentration were studied. The results reveal that adsorption of lead ions onto peach stone was stronger than onto apricot stone up to 3.36% at 3 h adsorption time. Suitable equilibrium time for the adsorption was 3-5 h (% Pb adsorption 93% for apricot and 97.64% for peach). The effective adsorption range for pH in the range was 7-8. Application of Langmuir and Freundlich isotherm models show high adsorption maximum and binding energies for using these adsorbents for the removal of lead ions from contaminated water and wastewater.

Optimal control of the orientation and alignment of an asymmetric-top molecule with terahertz and laser pulses

NASA Astrophysics Data System (ADS)

Coudert, L. H.

2018-03-01

Quantum optimal control theory is applied to determine numerically the terahertz and nonresonant laser pulses leading, respectively, to the highest degree of orientation and alignment of the asymmetric-top H2S molecule. The optimized terahertz pulses retrieved for temperatures of zero and 50 K lead after 50 ps to an orientation with ⟨ΦZx⟩ = 0.959 73 and ⟨⟨ΦZx⟩⟩ = 0.742 30, respectively. For the zero temperature, the orientation is close to its maximum theoretical value; for the higher temperature, it is below the maximum theoretical value. The mechanism by which the terahertz pulse populates high lying rotational levels is elucidated. The 5 ps long optimized laser pulse calculated for a zero temperature leads to an alignment with ⟨ΦZy 2 ⟩ =0.944 16 and consists of several kick pulses with a duration of ≈0.1 ps. It is found that the timing of these kick pulses is such that it leads to an increase of the rotational energy of the molecule. The optimized laser pulse retrieved for a temperature of 20 K is 6 ps long and yields a lower alignment with ⟨⟨ΦZy 2 ⟩ ⟩ =0.717 20 .

Removal of lead (II) ions from aqueous solutions onto activated carbon derived from waste biomass.

PubMed

Erdem, Murat; Ucar, Suat; Karagöz, Selhan; Tay, Turgay

2013-01-01

The removal of lead (II) ions from aqueous solutions was carried out using an activated carbon prepared from a waste biomass. The effects of various parameters such as pH, contact time, initial concentration of lead (II) ions, and temperature on the adsorption process were investigated. Energy Dispersive X-Ray Spectroscopy (EDS) analysis after adsorption reveals the accumulation of lead (II) ions onto activated carbon. The Langmuir and Freundlich isotherm models were applied to analyze equilibrium data. The maximum monolayer adsorption capacity of activated carbon was found to be 476.2 mg g⁻¹. The kinetic data were evaluated and the pseudo-second-order equation provided the best correlation. Thermodynamic parameters suggest that the adsorption process is endothermic and spontaneous.

Removal of Lead from Water Using Calcium Alginate Beads Doped with Hydrazine Sulphate-Activated Red Mud as Adsorbent

PubMed Central

2017-01-01

Calcium alginate beads doped with hydrazine sulphate-treated red mud are investigated as adsorbent for extracting lead ions from water using batch methods of extraction. Different extraction conditions are optimised for maximum lead extraction. Substantial amount of lead is removed, and the adsorption ability is found to be 138.6 mg/g. Surface characterization using FTIR, EDX, and FESEM confirms that lead is “onto” the surface of the adsorbent. Thermodynamic parameters, adsorption isotherms, and kinetics of adsorption are analysed. Adsorption is “physisorption” in nature and spontaneous. The adsorbent developed can be regenerated using 0.1 M HCl. Thus regenerated adsorbent can be used as the adsorbent for further removal of lead at least 10 times, and this enables the complete removal of lead from water by repetitive use of the regenerated adsorbent. The beads facilitate the easy filtration. The methodology developed is successfully applied for removing lead from industrial waste waters. PMID:29527385

The relationship between consistency of propulsive cycles and maximum angular velocity during wheelchair racing.

PubMed

Wang, Yong Tai; Vrongistinos, Konstantinos Dino; Xu, Dali

2008-08-01

The purposes of this study were to examine the consistency of wheelchair athletes' upper-limb kinematics in consecutive propulsive cycles and to investigate the relationship between the maximum angular velocities of the upper arm and forearm and the consistency of the upper-limb kinematical pattern. Eleven elite international wheelchair racers propelled their own chairs on a roller while performing maximum speeds during wheelchair propulsion. A Qualisys motion analysis system was used to film the wheelchair propulsive cycles. Six reflective markers placed on the right shoulder, elbow, wrist joints, metacarpal, wheel axis, and wheel were automatically digitized. The deviations in cycle time, upper-arm and forearm angles, and angular velocities among these propulsive cycles were analyzed. The results demonstrated that in the consecutive cycles of wheelchair propulsion the increased maximum angular velocity may lead to increased variability in the upper-limb angular kinematics. It is speculated that this increased variability may be important for the distribution of load on different upper-extremity muscles to avoid the fatigue during wheelchair racing.

Extraction of lead from waste CRT funnel glass by generating lead sulfide - An approach for electronic waste management.

PubMed

Hu, Biao; Hui, Wenlong

2017-09-01

Waste cathode ray tube (CRT) funnel glass is the key and difficult points in waste electrical and electronic equipment (WEEE) disposal. In this paper, a novel and effective process for the detoxification and reutilization of waste CRT funnel glass was developed by generating lead sulfide precipitate via a high-temperature melting process. The central function in this process was the generation of lead sulfide, which gathered at the bottom of the crucible and was then separated from the slag. Sodium carbonate was used as a flux and reaction agent, and sodium sulfide was used as a precipitating agent. The experimental results revealed that the lead sulfide recovery rate initially increased with an increase in the amount of added sodium carbonate, the amount of sodium sulfide, the temperature, and the holding time and then reached an equilibrium value. The maximum lead sulfide recovery rate was approximately 93%, at the optimum sodium carbonate level, sodium sulfide level, temperature, and holding time of 25%, 8%, 1200°C, and 2h, respectively. The glass slag can be made into sodium and potassium silicate by hydrolysis in an environmental and economical process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ensemble hydrological forecast efficiency evolution over various issue dates and lead-time: case study for the Cheboksary reservoir (Volga River)

NASA Astrophysics Data System (ADS)

Gelfan, Alexander; Moreido, Vsevolod

2017-04-01

Ensemble hydrological forecasting allows for describing uncertainty caused by variability of meteorological conditions in the river basin for the forecast lead-time. At the same time, in snowmelt-dependent river basins another significant source of uncertainty relates to variability of initial conditions of the basin (snow water equivalent, soil moisture content, etc.) prior to forecast issue. Accurate long-term hydrological forecast is most crucial for large water management systems, such as the Cheboksary reservoir (the catchment area is 374 000 sq.km) located in the Middle Volga river in Russia. Accurate forecasts of water inflow volume, maximum discharge and other flow characteristics are of great value for this basin, especially before the beginning of the spring freshet season that lasts here from April to June. The semi-distributed hydrological model ECOMAG was used to develop long-term ensemble forecast of daily water inflow into the Cheboksary reservoir. To describe variability of the meteorological conditions and construct ensemble of possible weather scenarios for the lead-time of the forecast, two approaches were applied. The first one utilizes 50 weather scenarios observed in the previous years (similar to the ensemble streamflow prediction (ESP) procedure), the second one uses 1000 synthetic scenarios simulated by a stochastic weather generator. We investigated the evolution of forecast uncertainty reduction, expressed as forecast efficiency, over various consequent forecast issue dates and lead time. We analyzed the Nash-Sutcliffe efficiency of inflow hindcasts for the period 1982 to 2016 starting from 1st of March with 15 days frequency for lead-time of 1 to 6 months. This resulted in the forecast efficiency matrix with issue dates versus lead-time that allows for predictability identification of the basin. The matrix was constructed separately for observed and synthetic weather ensembles.

Disintegration impact on sludge digestion process.

PubMed

Dauknys, Regimantas; Rimeika, Mindaugas; Jankeliūnaitė, Eglė; Mažeikienė, Aušra

2016-11-01

The anaerobic sludge digestion is a widely used method for sludge stabilization in wastewater treatment plant. This process can be improved by applying the sludge disintegration methods. As the sludge disintegration is not investigated enough, an analysis of how the application of thermal hydrolysis affects the sludge digestion process based on full-scale data was conducted. The results showed that the maximum volatile suspended solids (VSS) destruction reached the value of 65% independently on the application of thermal hydrolysis. The average VSS destruction increased by 14% when thermal hydrolysis was applied. In order to have the maximum VSS reduction and biogas production, it is recommended to keep the maximum defined VSS loading of 5.7 kg VSS/m(3)/d when the thermal hydrolysis is applied and to keep the VSS loading between 2.1-2.4 kg VSS/m(3)/d when the disintegration of sludge is not applied. The application of thermal hydrolysis leads to an approximately 2.5 times higher VSS loading maintenance comparing VSS loading without the disintegration; therefore, digesters with 1.8 times smaller volume is required.

40 CFR 421.254 - Standards of performance for new sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... average mg/troy ounce of gold refined electrolytically Lead 5.544 2.574 Mercury 2.970 1.188 Silver 5.742 2... property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0... reduced in solution Lead 0.112 0.052 Mercury 0.060 0.024 Silver 0.116 0.048 Zinc 0.408 0.168 Gold 0.040...

Global warming related transient albedo feedback in the Arctic and its relation to the seasonality of sea ice

NASA Astrophysics Data System (ADS)

Andry, Olivier; Bintanja, Richard; Hazeleger, Wilco

2015-04-01

The Arctic is warming two to three times faster than the global average. Arctic sea ice cover is very sensitive to this warming and has reached historic minima in late summer in recent years (i.e. 2007, 2012). Considering that the Arctic Ocean is mainly ice-covered and that the albedo of sea ice is very high compared to that of open water, the change in sea ice cover is very likely to have a strong impact on the local surface albedo feedback. Here we quantify the temporal changes in surface albedo feedback in response to global warming. Usually feedbacks are evaluated as being representative and constant for long time periods, but we show here that the strength of climate feedbacks in fact varies strongly with time. For instance, time series of the amplitude of the surface albedo feedback, derived from future climate simulations (CIMP5, RCP8.5 up to year 2300) using a kernel method, peaks around the year 2100. This maximum is likely caused by an increased seasonality in sea-ice cover that is inherently associated with sea ice retreat. We demonstrate that the Arctic average surface albedo has a strong seasonal signature with a maximum in spring and a minimum in late summer/autumn. In winter when incoming solar radiation is minimal the surface albedo doesn't have an important effect on the energy balance of the climate system. The annual mean surface albedo is thus determined by the seasonality of both downwelling shortwave radiation and sea ice cover. As sea ice cover reduces the seasonal signature is modified, the transient part from maximum sea ice cover to its minimum is shortened and sharpened. The sea ice cover is reduced when downwelling shortwave radiation is maximum and thus the annual surface albedo is drastically smaller. Consequently the change in annual surface albedo with time will become larger and so will the surface albedo feedback. We conclude that a stronger seasonality in sea ice leads to a stronger surface albedo feedback, which accelerates melting of sea ice. Hence, the change in seasonality and the associated change in feedback strength is an integral part of the positive surface albedo feedback leading to Arctic amplification and diminishing sea ice cover in the next century when global climate warms.

Sequestration of toxic Pb(II) ions by chemically treated rubber (Hevea brasiliensis) leaf powder.

PubMed

Kamal, Megat Hanafiah Megat Ahmad; Azira, Wan Mat Khalir Wan Khaima; Kasmawati, Mohamed; Haslizaidi, Zakaria; Saime, Wan Ngah Wan

2010-01-01

Rubber leaf powder (an agricultural waste) was treated with potassium permanganate followed by sodium carbonate and its performance in the removal of Pb(II) ions from aqueous solution was evaluated. The interactions between Pb(II) ions and functional groups on the adsorbent surface were confirmed by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX). The effects of several important parameters which can affect adsorption capacity such as pH, adsorbent dosage, initial lead concentration and contact time were studied. The optimum pH range for lead adsorption was 4-5. Even at very low adsorbent dosage of 0.02 g, almost 100% of Pb(II) ions (23 mg/L) could be removed. The adsorption capacity was also dependent on lead concentration and contact time, and relatively a short period of time (60-90 min) was required to reach equilibrium. The equilibrium data were analyzed with Langmuir, Freundlich and Dubinin-Radushkevich isotherms. Based on Langmuir model, the maximum adsorption capacity of lead was 95.3 mg/g. Three kinetic models including pseudo first-order, pseudo second-order and Boyd were used to analyze the lead adsorption process, and the results showed that the pseudo second-order fitted well with correlation coefficients greater than 0.99.

Maruhn-Greiner Maximum of Uranium Fission for Confirmation of Low Energy Nuclear Reactions LENR via a Compound Nucleus with Double Magic Numbers

NASA Astrophysics Data System (ADS)

Hora, H.; Miley, G. H.

2007-12-01

One of the most convincing facts about LENR due to deuterons of very high concentration in host metals as palladium is the measurement of the large scale minimum of the reaction probability depending on the nucleon number A of generated elements at A = 153 where a local maximum was measured. This is similar to the fission of uranium at A = 119 where the local maximum follows from the Maruhn-Greiner theory if the splitting nuclei are excited to about MeV energy. The LENR generated elements can be documented any time after the reaction by SIMS or K-shell X-ray excitation to show the very unique distribution with the local maximum. An explanation is based on the strong Debye screening of the Maxwellian deuterons within the degenerate rigid electron background especially within the swimming electron layer at the metal surface or at interfaces. The deuterons behave like neutrals at distances of about 2 picometers. They may form clusters due to soft attraction in the range above thermal energy. Clusters of 10 pm diameter may react over long time probabilities (megaseconds) with Pd nuclei leading to a double magic number compound nucleus which splits like in fission to the A = 153 element distribution.

Scheduling rules to achieve lead-time targets in outpatient appointment systems.

PubMed

Nguyen, Thu-Ba T; Sivakumar, Appa Iyer; Graves, Stephen C

2017-12-01

This paper considers how to schedule appointments for outpatients, for a clinic that is subject to appointment lead-time targets for both new and returning patients. We develop heuristic rules, which are the exact and relaxed appointment scheduling rules, to schedule each new patient appointment (only) in light of uncertainty about future arrivals. The scheduling rules entail two decisions. First, the rules need to determine whether or not a patient's request can be accepted; then, if the request is not rejected, the rules prescribe how to assign the patient to an available slot. The intent of the scheduling rules is to maximize the utilization of the planned resource (i.e., the physician staff), or equivalently to maximize the number of patients that are admitted, while maintaining the service targets on the median, the 95th percentile, and the maximum appointment lead-times. We test the proposed scheduling rules with numerical experiments using real data from the chosen clinic of Tan Tock Seng hospital in Singapore. The results show the efficiency and the efficacy of the scheduling rules, in terms of the service-target satisfaction and the resource utilization. From the sensitivity analysis, we find that the performance of the proposed scheduling rules is fairly robust to the specification of the established lead-time targets.

The Use of Ion Implantation for Materials Processing.

DTIC Science & Technology

1980-10-06

consists of a series of sections, each section being an annular insulator (glass) and a shaped metal electrode (polished aluminum ) cemented together. A...depending on the ion species, semiconductor material, attached materials (such as aluminum leads), implantation energy, and dose; but some devices are...concentration of subsurface carbon. Appearing directly beneath the oxide layer, the C concentration first reaches a maximum of about five times the bulk

40 CFR 464.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... copper, lead, zinc, and total phenols. For non-continuous dischargers, annual average mass limitations....0771 0.0421 Lead (T) 0.0791 0.039 Zinc (T) 0.114 0.0431 Maximum for any 1 day Maximum for monthly average Annual average 1 (mg/l) 2 (mg/l) 2 Copper (T) 0.77 0.42 0.017 Lead (T) 0.79 0.39 0.022 Zinc (T) 1...

40 CFR 464.13 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... copper, lead, zinc, and total phenols. For non-continuous dischargers, annual average mass limitations....0771 0.0421 Lead (T) 0.0791 0.039 Zinc (T) 0.114 0.0431 Maximum for any 1 day Maximum for monthly average Annual average 1 (mg/l) 2 (mg/l) 2 Copper (T) 0.77 0.42 0.017 Lead (T) 0.79 0.39 0.022 Zinc (T) 1...

Dynamic-MLC leaf control utilizing on-flight intensity calculations: a robust method for real-time IMRT delivery over moving rigid targets.

PubMed

McMahon, Ryan; Papiez, Lech; Rangaraj, Dharanipathy

2007-08-01

An algorithm is presented that allows for the control of multileaf collimation (MLC) leaves based entirely on real-time calculations of the intensity delivered over the target. The algorithm is capable of efficiently correcting generalized delivery errors without requiring the interruption of delivery (self-correcting trajectories), where a generalized delivery error represents anything that causes a discrepancy between the delivered and intended intensity profiles. The intensity actually delivered over the target is continually compared to its intended value. For each pair of leaves, these comparisons are used to guide the control of the following leaf and keep this discrepancy below a user-specified value. To demonstrate the basic principles of the algorithm, results of corrected delivery are shown for a leading leaf positional error during dynamic-MLC (DMLC) IMRT delivery over a rigid moving target. It is then shown that, with slight modifications, the algorithm can be used to track moving targets in real time. The primary results of this article indicate that the algorithm is capable of accurately delivering DMLC IMRT over a rigid moving target whose motion is (1) completely unknown prior to delivery and (2) not faster than the maximum MLC leaf velocity over extended periods of time. These capabilities are demonstrated for clinically derived intensity profiles and actual tumor motion data, including situations when the target moves in some instances faster than the maximum admissible MLC leaf velocity. The results show that using the algorithm while calculating the delivered intensity every 50 ms will provide a good level of accuracy when delivering IMRT over a rigid moving target translating along the direction of MLC leaf travel. When the maximum velocities of the MLC leaves and target were 4 and 4.2 cm/s, respectively, the resulting error in the two intensity profiles used was 0.1 +/- 3.1% and -0.5 +/- 2.8% relative to the maximum of the intensity profiles. For the same target motion, the error was shown to increase rapidly as (1) the maximum MLC leaf velocity was reduced below 75% of the maximum target velocity and (2) the system response time was increased.

Removal of Pb(II) and Cd(II) from water by adsorption on peels of banana.

PubMed

Anwar, Jamil; Shafique, Umer; Waheed-uz-Zaman; Salman, Muhammad; Dar, Amara; Anwar, Shafique

2010-03-01

The adsorption of lead(II) and cadmium(II) on peels of banana has been studied in batch mode using flame atomic absorption spectroscopy for metal estimation. Concerned parameters like adsorbent dose, pH, contact time and agitation speed were investigated. Langmuir, Freundlich and Temkin isotherms were employed to describe adsorption equilibrium. The maximum amounts of cadmium(II) and lead(II) adsorbed (qm), as evaluated by Langmuir isotherm, were 5.71 mg and 2.18 mg per gram of powder of banana peels, respectively. Study concluded that banana peels, a waste material, have good potential as an adsorbent to remove toxic metals like lead and cadmium from water. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Quasi- and pseudo-maximum likelihood estimators for discretely observed continuous-time Markov branching processes

PubMed Central

Chen, Rui; Hyrien, Ollivier

2011-01-01

This article deals with quasi- and pseudo-likelihood estimation in a class of continuous-time multi-type Markov branching processes observed at discrete points in time. “Conventional” and conditional estimation are discussed for both approaches. We compare their properties and identify situations where they lead to asymptotically equivalent estimators. Both approaches possess robustness properties, and coincide with maximum likelihood estimation in some cases. Quasi-likelihood functions involving only linear combinations of the data may be unable to estimate all model parameters. Remedial measures exist, including the resort either to non-linear functions of the data or to conditioning the moments on appropriate sigma-algebras. The method of pseudo-likelihood may also resolve this issue. We investigate the properties of these approaches in three examples: the pure birth process, the linear birth-and-death process, and a two-type process that generalizes the previous two examples. Simulations studies are conducted to evaluate performance in finite samples. PMID:21552356

An approach to optimal semi-active control of vibration energy harvesting based on MEMS

NASA Astrophysics Data System (ADS)

Rojas, Rafael A.; Carcaterra, Antonio

2018-07-01

In this paper the energy harvesting problem involving typical MEMS technology is reduced to an optimal control problem, where the objective function is the absorption of the maximum amount of energy in a given time interval from a vibrating environment. The interest here is to identify a physical upper bound for this energy storage. The mathematical tool is a new optimal control called Krotov's method, that has not yet been applied to engineering problems, except in quantum dynamics. This approach leads to identify new maximum bounds to the energy harvesting performance. Novel MEMS-based device control configurations for vibration energy harvesting are proposed with particular emphasis to piezoelectric, electromagnetic and capacitive circuits.

Performance advantages of maximum likelihood methods in PRBS-modulated time-of-flight electron energy loss spectroscopy

NASA Astrophysics Data System (ADS)

Yang, Zhongyu

This thesis describes the design, experimental performance, and theoretical simulation of a novel time-of-flight analyzer that was integrated into a high resolution electron energy loss spectrometer (TOF-HREELS). First we examined the use of an interleaved comb chopper for chopping a continuous electron beam. Both static and dynamic behaviors were simulated theoretically and measured experimentally, with very good agreement. The finite penetration of the field beyond the plane of the chopper leads to non-ideal chopper response, which is characterized in terms of an "energy corruption" effect and a lead or lag in the time at which the beam responds to the chopper potential. Second we considered the recovery of spectra from pseudo-random binary sequence (PRBS) modulated TOF-HREELS data. The effects of the Poisson noise distribution and the non-ideal behavior of the "interleaved comb" chopper were simulated. We showed, for the first time, that maximum likelihood methods can be combined with PRBS modulation to achieve resolution enhancement, while properly accounting for the Poisson noise distribution and artifacts introduced by the chopper. Our results indicate that meV resolution, similar to that of modern high resolution electron energy loss spectrometers, can be achieved with a dramatic performance advantage over conventional, serial detection analyzers. To demonstrate the capabilities of the TOF-HREELS instrument, we made measurements on a highly oriented thin film polytetrafluoroethylene (PTFE) sample. We demonstrated that the TOF-HREELS can achieve a throughput advantage of a factor of 85 compared to the conventional HREELS instrument. Comparisons were made between the experimental results and theoretical simulations. We discuss various factors which affect inversion of PRBS modulated Time of Flight (TOF) data with the Lucy algorithm. Using simulations, we conclude that the convolution assumption was good under the conditions of our experiment. The chopper rise time, Poisson noise, and artifacts of the chopper response are evaluated. Finally, we conclude that the maximum likelihood algorithms are able to gain a multiplex advantage in PRBS modulation, despite the Poisson noise in the detector.

Superconducting current injection transistor with very high critical-current-density edge-junctions

NASA Astrophysics Data System (ADS)

van Zeghbroeck, B. J.

1985-03-01

A Superconducting Current Injection Transistor (Super-CIT) was fabricated with very high critical current-density edge-junctions. The junctions have a niobium base electrode and a lead-alloy counter electrode. The length of the junctions is 30 microns and the critical-current density is 190KA/sq cm. The Super-CIT has a current gain of 2, a large signal transresistance of 100 mV/A, and the turn-on delay, inferred from the junction resonance, is 7ps. The power dissipation is 3.5 microwatts and the power-delay product is 24.5aJ. Gap reduction due to heating was observed, limiting the maximum power dissipation per unit length to 1.1 microwatt/micron. Compared to lead-alloy Super-CITs, the device is five times smaller, three times faster, and has a three times larger output voltage. The damping resistor and the contact junction could also be eliminated.

Temperature Observation Time and Type Influence Estimates of Heat-Related Mortality in Seven U.S. Cities.

PubMed

Davis, Robert E; Hondula, David M; Patel, Anjali P

2016-06-01

Extreme heat is a leading weather-related cause of mortality in the United States, but little guidance is available regarding how temperature variable selection impacts heat-mortality relationships. We examined how the strength of the relationship between daily heat-related mortality and temperature varies as a function of temperature observation time, lag, and calculation method. Long time series of daily mortality counts and hourly temperature for seven U.S. cities with different climates were examined using a generalized additive model. The temperature effect was modeled separately for each hour of the day (with up to 3-day lags) along with different methods of calculating daily maximum, minimum, and mean temperature. We estimated the temperature effect on mortality for each variable by comparing the 99th versus 85th temperature percentiles, as determined from the annual time series. In three northern cities (Boston, MA; Philadelphia, PA; and Seattle, WA) that appeared to have the greatest sensitivity to heat, hourly estimates were consistent with a diurnal pattern in the heat-mortality response, with strongest associations for afternoon or maximum temperature at lag 0 (day of death) or afternoon and evening of lag 1 (day before death). In warmer, southern cities, stronger associations were found with morning temperatures, but overall the relationships were weaker. The strongest temperature-mortality relationships were associated with maximum temperature, although mean temperature results were comparable. There were systematic and substantial differences in the association between temperature and mortality based on the time and type of temperature observation. Because the strongest hourly temperature-mortality relationships were not always found at times typically associated with daily maximum temperatures, temperature variables should be selected independently for each study location. In general, heat-mortality was more closely coupled to afternoon and maximum temperatures in most cities we examined, particularly those typically prone to heat-related mortality. Davis RE, Hondula DM, Patel AP. 2016. Temperature observation time and type influence estimates of heat-related mortality in seven U.S. cities. Environ Health Perspect 124:795-804; http://dx.doi.org/10.1289/ehp.1509946.

Temperature Observation Time and Type Influence Estimates of Heat-Related Mortality in Seven U.S. Cities

PubMed Central

Davis, Robert E.; Hondula, David M.; Patel, Anjali P.

2015-01-01

Background: Extreme heat is a leading weather-related cause of mortality in the United States, but little guidance is available regarding how temperature variable selection impacts heat–mortality relationships. Objectives: We examined how the strength of the relationship between daily heat-related mortality and temperature varies as a function of temperature observation time, lag, and calculation method. Methods: Long time series of daily mortality counts and hourly temperature for seven U.S. cities with different climates were examined using a generalized additive model. The temperature effect was modeled separately for each hour of the day (with up to 3-day lags) along with different methods of calculating daily maximum, minimum, and mean temperature. We estimated the temperature effect on mortality for each variable by comparing the 99th versus 85th temperature percentiles, as determined from the annual time series. Results: In three northern cities (Boston, MA; Philadelphia, PA; and Seattle, WA) that appeared to have the greatest sensitivity to heat, hourly estimates were consistent with a diurnal pattern in the heat-mortality response, with strongest associations for afternoon or maximum temperature at lag 0 (day of death) or afternoon and evening of lag 1 (day before death). In warmer, southern cities, stronger associations were found with morning temperatures, but overall the relationships were weaker. The strongest temperature–mortality relationships were associated with maximum temperature, although mean temperature results were comparable. Conclusions: There were systematic and substantial differences in the association between temperature and mortality based on the time and type of temperature observation. Because the strongest hourly temperature–mortality relationships were not always found at times typically associated with daily maximum temperatures, temperature variables should be selected independently for each study location. In general, heat-mortality was more closely coupled to afternoon and maximum temperatures in most cities we examined, particularly those typically prone to heat-related mortality. Citation: Davis RE, Hondula DM, Patel AP. 2016. Temperature observation time and type influence estimates of heat-related mortality in seven U.S. cities. Environ Health Perspect 124:795–804; http://dx.doi.org/10.1289/ehp.1509946 PMID:26636734

The leading-edge vortex of yacht sails

NASA Astrophysics Data System (ADS)

Arredondo-Galeana, Abel; Viola, Ignazio Maria

2017-11-01

We experimentally show, for the first time, that a stable Leading-Edge Vortex (LEV) can be formed on an asymmetric spinnaker, which is a high-lift sail used by yachts to sail downwind. We tested a 3D printed rigid sail in a water flume at a chord-based Reynolds number of ca. 104. We found that on the leeward side of the sail (the suction side), the flow separates at the leading edge reattaching further downstream and forming a stable LEV. The LEV grows in diameter from the root to the tip of the sail, where it merges with the tip vortex. We detected the LEV using the γ criterion, and we verified its stability over time. The lift contribution provided by the LEV was computed solving a complex potential model of each sail section. This analysis indicated that the LEV provides a substantial contribution to the total sail's lift. These findings suggest that the maximum lift of low-aspect-ratio wings with a sharp leading edge, such as spinnakers, can be enhanced by promoting a stable LEV. This work was funded by the Consejo Nacional de Ciencia y Tecnologia (CONACYT).

Biosorption of toxic lead (II) ions using tomato waste (Solanum lycopersicum) activated by NaOH

NASA Astrophysics Data System (ADS)

Permatasari, Diah; Heraldy, Eddy; Lestari, Witri Wahyu

2016-02-01

This research present to uptake lead (II) ion from aqueous solutions by activated tomato waste. Biosorbent were characterized by applying Fourier Transform Infrared Spectroscopy (FTIR) and Surface Area Analyzer (SAA). The biosorption investigated with parameters including the concentration of NaOH, effects of solution pH, biosorbent dosage, contact time,and initial metal concentration. Experimental data were analyzed in terms of two kinetic model such us the pseudo-first order and pseudo-second order. Langmuir and Freundlich isotherm models were applied todescribe the biosorption process. According to the experiment, the optimum concentration of NaOH was achieved at 0.1 M. The maximum % lead (II) removal was achieved at pH 4 with 94.5%. Optimum biosorbentdosage were found as 0.1 g/25 mL solution while optimum contact time were found at 75 minutes. The results showed that the biosorption processes of Lead (II) followed pseudo-second order kinetics. Langmuir adsorption isotherm was found fit the adsorption data with amaximum capacity of 24.079 mg/g with anadsorption energy of 28.046 kJ/mol.

Design, synthesis, and taste evaluation of a high-intensity umami-imparting oxazole-based compound.

PubMed

Amino, Yusuke; Tahara, Yu-Ki; Yamada, Kei; Nakazawa, Masakazu; Tagami, Uno; Tajima, Takaho; Kuroda, Motonaka

2017-09-01

Umami taste is imparted predominantly by monosodium glutamate (MSG) and 5'-ribonucleotides. Recently, several different classes of hydrophobic umami-imparting compounds, the structures of which are quite different from MSG, have been reported. To obtain a novel umami-imparting compound, N-cinnamoyl phenethylamine was chosen as the lead compound, and a rational structure-optimization study was conducted on the basis of the pharmacophore model of previously reported compounds. The extremely potent umami-imparting compound 2-[[[2-[(1E)-2-(1,3-benzodioxol-5-yl)ethenyl]-4-oxazolyle]methoxy]methyl]pyridine, which exhibits 27,000 times the umami taste of MSG, was found. Its terminal pyridine residue and linear structure are suggested to be responsible for its strong activity. The time taken to reach maximum taste intensity exhibited by it, as determined by the time-intensity method, is 22.0 s, whereas the maximum taste intensity of MSG occurs immediately. This distinct difference in the time-course taste profile may be due to the hydrophobicity and strong receptor affinity of the new compound.

Lean thinking transformation of the unsedated upper gastrointestinal endoscopy pathway improves efficiency and is associated with high levels of patient satisfaction.

PubMed

Hydes, Theresa; Hansi, Navjyot; Trebble, Timothy M

2012-01-01

Upper gastrointestinal (UGI) endoscopy is a routine healthcare procedure with a defined patient pathway. The objective of this study was to redesign this pathway for unsedated patients using lean thinking transformation to focus on patient-derived value-adding steps, remove waste and create a more efficient process. This was to form the basis of a pathway template that was transferrable to other endoscopy units. A literature search of patient expectations for UGI endoscopy identified patient-derived value. A value stream map was created of the current pathway. The minimum and maximum time per step, bottlenecks and staff-staff interactions were recorded. This information was used for service transformation using lean thinking. A patient pathway template was created and implemented into a secondary unit. Questionnaire studies were performed to assess patient satisfaction. In the primary unit the patient pathway reduced from 19 to 11 steps with a reduction in the maximum lead time from 375 to 80 min following lean thinking transformation. The minimum value/lead time ratio increased from 24% to 49%. The patient pathway was redesigned as a 'cellular' system with minimised patient and staff travelling distances, waiting times, paperwork and handoffs. Nursing staff requirements reduced by 25%. Patient-prioritised aspects of care were emphasised with increased patient-endoscopist interaction time. The template was successfully introduced into a second unit with an overall positive patient satisfaction rating of 95%. Lean thinking transformation of the unsedated UGI endoscopy pathway results in reduced waiting times, reduced staffing requirements and improved patient flow and can form the basis of a pathway template which may be successfully transferred into alternative endoscopy environments with high levels of patient satisfaction.

Estimators for longitudinal latent exposure models: examining measurement model assumptions.

PubMed

Sánchez, Brisa N; Kim, Sehee; Sammel, Mary D

2017-06-15

Latent variable (LV) models are increasingly being used in environmental epidemiology as a way to summarize multiple environmental exposures and thus minimize statistical concerns that arise in multiple regression. LV models may be especially useful when multivariate exposures are collected repeatedly over time. LV models can accommodate a variety of assumptions but, at the same time, present the user with many choices for model specification particularly in the case of exposure data collected repeatedly over time. For instance, the user could assume conditional independence of observed exposure biomarkers given the latent exposure and, in the case of longitudinal latent exposure variables, time invariance of the measurement model. Choosing which assumptions to relax is not always straightforward. We were motivated by a study of prenatal lead exposure and mental development, where assumptions of the measurement model for the time-changing longitudinal exposure have appreciable impact on (maximum-likelihood) inferences about the health effects of lead exposure. Although we were not particularly interested in characterizing the change of the LV itself, imposing a longitudinal LV structure on the repeated multivariate exposure measures could result in high efficiency gains for the exposure-disease association. We examine the biases of maximum likelihood estimators when assumptions about the measurement model for the longitudinal latent exposure variable are violated. We adapt existing instrumental variable estimators to the case of longitudinal exposures and propose them as an alternative to estimate the health effects of a time-changing latent predictor. We show that instrumental variable estimators remain unbiased for a wide range of data generating models and have advantages in terms of mean squared error. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Ambient lead measurements in Cairo, Egypt

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

Howes, J.E. Jr.; Labib, M.; Samaha, N.

1999-07-01

The Cairo Air Improvement Project (CAIP) has established a network of 36 stations to monitor airborne lead levels in the Greater Cairo Area. Data obtained during the first 4 months of the monitoring program indicates that lead levels in ambient air significantly exceed the Government of Egypt's (GOE) Law Number 4 (1994) limit of 1 {micro} g/m{sup 3} (annual mean) in areas downwind of secondary lead smelters and in heavily trafficked areas. The highest mean and single sampling event lead levels were observed in the heavily industrialized areas of Shoubra el-Kheima and Tebbin. At two sites in Shoubra el-Kheima, meanmore » and maximum lead levels were determined to be approximately 20 {micro} g/m{sup 3} and 79 {micro} g/m{sup 3}, respectively. At three sites located in areas of high motor vehicle traffic in the central part of the city, the mean lead level was about 4 {micro} g/m{sup 3} and the maximum levels ranged from approximately 10 x 20 {micro} g/m{sup 3}. Of the remainder of the sites, the mean lead concentrations were 2fd3 {micro} g/m{sup 3} at three sites, 1 P2 {mu} g/m{sup 3} at 16 sites, and below 1 {micro} g/m{sup 3} at eight sites. Lead levels in areas devoted primarily to residential use were generally less than 2 {micro} g/m{sup 3}. The maximum mean monthly PM{sub 10} lead value measured at fugitive emission monitoring sites near lead smelters was approximately 73 {micro} g/m{sup 3}. The maximum lead concentration measured during a single sampling event was 180 {micro} g/m{sup 3}. Generally lower lead levels were observed in December due to regulation action that resulted in some suspension of smelting operations and to approximately 180-degree wind direction shifts that typically occur during this period of the year. The GOE is working vigorously to eliminate the lead problem in Egypt through implementation of the Lead Exposure Action Plan (LEAP). A major component of LEAP is the Lead Smelter Action Plan (LSAP).« less

Blood lead and carboxyhemoglobin levels in chainsaw operators.

PubMed

van Netten, C; Brubaker, R L; Mackenzie, C J; Godolphin, W J

1987-06-01

Fallers in the British Columbia west coast lumber industry often work in climatic and local conditions where little ventilation in their immediate environment is possible. Under these conditions carbon monoxide (CO) and lead fumes from exhaust gases could build up and become a serious occupational hazard. This study monitored the environmental exposure of six fallers to carbon monoxide, nitrogen oxides, and lead under conditions where buildup of these agents would be expected. At the same time blood samples were taken to correlate these environmental concentrations to carboxyhemoglobin (COHb) and blood lead levels. Although there was a highly significant difference between the fallers and the controls regarding the exposure to CO and lead as well as their corresponding COHb and blood lead levels, the environmental and blood concentration of the agents in question did not exceed the maximum allowable concentrations. Temporary short fluctuations in carboxyhemoglobin levels were not monitored in this study and cannot be ruled out as a potential occupational hazard.

Removal of lead, cadmium, zinc, and copper from industrial wastewater by carbon developed from walnut, hazelnut, almond, pistachio shell, and apricot stone.

PubMed

Kazemipour, Maryam; Ansari, Mehdi; Tajrobehkar, Shabnam; Majdzadeh, Majdeh; Kermani, Hamed Reihani

2008-01-31

In this work, adsorption of copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) that exist in industrial wastewater onto the carbon produced from nutshells of walnut, hazelnut, pistachio, almond, and apricot stone has been investigated. All the agricultural shell or stone used were ground, sieved to a defined size range, and carbonized in an oven. Time and temperature of heating were optimized at 15 min and 800 degrees C, respectively, to reach maximum removal efficiency. Removal efficiency was optimized regarding to the initial pH, flow rate, and dose of adsorbent. The maximum removal occurred at pH 6-10, flow rate of 3 mL/min, and 0.1g of the adsorbent. Capacity of carbon sources for removing cations will be considerably decreased in the following times of passing through them. Results showed that the cations studied significantly can be removed by the carbon sources. Efficiency of carbon to remove the cations from real wastewater produced by copper industries was also studied. Finding showed that not only these cations can be removed considerably by the carbon sources noted above, but also removing efficiency are much more in the real samples. These results were in adoption to those obtained by standard mixture synthetic wastewater.

40 CFR 464.43 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting... copper, lead, zinc, and total phenols. For non-continuous dischargers, annual average mass limitations....0187 Lead (T) 0.0237 0.0116 Zinc (T) 0.0339 0.0129 Maximum for any 1 day Maximum for monthly average...

40 CFR 464.43 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting... copper, lead, zinc, and total phenols. For non-continuous dischargers, annual average mass limitations....0187 Lead (T) 0.0237 0.0116 Zinc (T) 0.0339 0.0129 Maximum for any 1 day Maximum for monthly average...

A technique for position sensing and improved momentum evaluation of microparticle impacts in space.

NASA Technical Reports Server (NTRS)

Mcdonnell, J. A. M.; Abellanas, C.

1972-01-01

The design of a three element piezoelectric microparticle impact sensing diaphragm is described which is sensitive to the detection of momentum propagated by the bending wave. The design achieves a sensitivity of .03 microdyn/sec and optimizes the detection of the direct-path pulse from impact relative to secondary reflections and interference from discontinuities. Measurement of the relative arrival times and the maximum amplitudes of the outputs from the three piezoelectric sensors leads to the determination of the impact position and the normally resolved impact momentum exchange. Coincidence of the signals and a partial redundancy of data leads to a very high noise discrimination.

Trading Time with Space - Development of subduction zone parameter database for a maximum magnitude correlation assessment

NASA Astrophysics Data System (ADS)

Schaefer, Andreas; Wenzel, Friedemann

2017-04-01

Subduction zones are generally the sources of the earthquakes with the highest magnitudes. Not only in Japan or Chile, but also in Pakistan, the Solomon Islands or for the Lesser Antilles, subduction zones pose a significant hazard for the people. To understand the behavior of subduction zones, especially to identify their capabilities to produce maximum magnitude earthquakes, various physical models have been developed leading to a large number of various datasets, e.g. from geodesy, geomagnetics, structural geology, etc. There have been various studies to utilize this data for the compilation of a subduction zone parameters database, but mostly concentrating on only the major zones. Here, we compile the largest dataset of subduction zone parameters both in parameter diversity but also in the number of considered subduction zones. In total, more than 70 individual sources have been assessed and the aforementioned parametric data have been combined with seismological data and many more sources have been compiled leading to more than 60 individual parameters. Not all parameters have been resolved for each zone, since the data completeness depends on the data availability and quality for each source. In addition, the 3D down-dip geometry of a majority of the subduction zones has been resolved using historical earthquake hypocenter data and centroid moment tensors where available and additionally compared and verified with results from previous studies. With such a database, a statistical study has been undertaken to identify not only correlations between those parameters to estimate a parametric driven way to identify potentials for maximum possible magnitudes, but also to identify similarities between the sources themselves. This identification of similarities leads to a classification system for subduction zones. Here, it could be expected if two sources share enough common characteristics, other characteristics of interest may be similar as well. This concept technically trades time with space, considering subduction zones where we have likely not observed the maximum possible event yet. However, by identifying sources of the same class, the not-yet observed temporal behavior can be replaced by spatial similarity among different subduction zones. This database aims to enhance the research and understanding of subduction zones and to quantify their potential in producing mega earthquakes considering potential strong motion impact on nearby cities and their tsunami potential.

Teaching the principles of statistical dynamics

PubMed Central

Ghosh, Kingshuk; Dill, Ken A.; Inamdar, Mandar M.; Seitaridou, Effrosyni; Phillips, Rob

2012-01-01

We describe a simple framework for teaching the principles that underlie the dynamical laws of transport: Fick’s law of diffusion, Fourier’s law of heat flow, the Newtonian viscosity law, and the mass-action laws of chemical kinetics. In analogy with the way that the maximization of entropy over microstates leads to the Boltzmann distribution and predictions about equilibria, maximizing a quantity that E. T. Jaynes called “caliber” over all the possible microtrajectories leads to these dynamical laws. The principle of maximum caliber also leads to dynamical distribution functions that characterize the relative probabilities of different microtrajectories. A great source of recent interest in statistical dynamics has resulted from a new generation of single-particle and single-molecule experiments that make it possible to observe dynamics one trajectory at a time. PMID:23585693

Teaching the principles of statistical dynamics.

PubMed

Ghosh, Kingshuk; Dill, Ken A; Inamdar, Mandar M; Seitaridou, Effrosyni; Phillips, Rob

2006-02-01

We describe a simple framework for teaching the principles that underlie the dynamical laws of transport: Fick's law of diffusion, Fourier's law of heat flow, the Newtonian viscosity law, and the mass-action laws of chemical kinetics. In analogy with the way that the maximization of entropy over microstates leads to the Boltzmann distribution and predictions about equilibria, maximizing a quantity that E. T. Jaynes called "caliber" over all the possible microtrajectories leads to these dynamical laws. The principle of maximum caliber also leads to dynamical distribution functions that characterize the relative probabilities of different microtrajectories. A great source of recent interest in statistical dynamics has resulted from a new generation of single-particle and single-molecule experiments that make it possible to observe dynamics one trajectory at a time.

Assessment of Heat Hazard during the Polymerization of Selected Light-Sensitive Dental Materials.

PubMed

Janeczek, Maciej; Herman, Katarzyna; Fita, Katarzyna; Dudek, Krzysztof; Kowalczyk-Zając, Małgorzata; Czajczyńska-Waszkiewicz, Agnieszka; Piesiak-Pańczyszyn, Dagmara; Kosior, Piotr; Dobrzyński, Maciej

2016-01-01

Introduction. Polymerization of light-cured dental materials used for restoration of hard tooth tissue may lead to an increase in temperature that may have negative consequence for pulp vitality. Aim. The aim of this study was to determine maximum temperatures reached during the polymerization of selected dental materials, as well as the time that is needed for samples of sizes similar to those used in clinical practice to reach these temperatures. Materials and Methods. The study involved four composite restorative materials, one lining material and a dentine bonding agent. The polymerization was conducted with the use of a diode light-curing unit. The measurements of the external surface temperature of the samples were carried out using the Thermovision®550 thermal camera. Results. The examined materials significantly differed in terms of the maximum temperatures values they reached, as well as the time required for reaching the temperatures. A statistically significant positive correlation of the maximum temperature and the sample weight was observed. Conclusions. In clinical practice, it is crucial to bear in mind the risk of thermal damage involved in the application of light-cured materials. It can be reduced by using thin increments of composite materials.

Langley Full-scale-tunnel Investigation of Maximum Lift and Stability Characteristics of an Airplane Having Approximately Triangular Plan Form (DM-1 Glider)

NASA Technical Reports Server (NTRS)

Lovell, J Calvin; Wilson, Herbert A JR

1947-01-01

An investigation of the DM-1 Glider, which had approximately triangular plan form, an aspect ratio of 1.8 and a 60 degree sweptback leading edge, has been conducted in the Langley full-scale tunnel. The investigation consisted of the determination of the separate effects of the following modifications made to the glider on its maximum lift and stability characteristics: (a) installation of sharp leading edges over the inboard semispan of the wing, (b) removal of the vertical fin, (c) sealing of the elevon control-balance slots, (d) installation of redesigned thin vertical surfaces, (e) installation of faired sharp leading edges, and (f) installation of canopy. The maximum lift coefficient of the DM-1 glider was increased from 0.61 to 1.01 by the installation of semispan sharp leading edges, and from 1.01 to 1.24 by the removal of the vertical fin and sealing of the elevon control-balance slots. The highest maximum lift coefficient (1.32) was obtained when the faired sharp leading edges and the thin vertical surfaces were attached to the glider. The original DM-1 glider was longitudinally stable. The semispan sharp leading edges shifted the neutral point forward approximately 3 percent of the root chord at moderate lift coefficients, and the glider configuration with these sharp leading edges attached was longitudinally unstable, for the assumed center-of-gravity location, at lift coefficients above 0.73. Sealing the elevon control-balance slots and installing the faired sharp leading edges, the thin vertical surfaces, and the canopy shifted the neutral point forward approximately 8 percent of the root chord.

Influence of pregnancy and smoking on brachial artery flow-mediated dilation values and time until maximum response.

PubMed

Nicolau, Luis G C; Martins, Wellington P; Gallarreta, Francisco M P; Lima, Jailson C; Filho, Francisco Mauad

2011-08-01

To evaluate the effect of pregnancy and smoking on endothelial function using brachial artery flow-mediated dilation (FMD) and to determine the time necessary until the occurrence of maximum brachial artery dilation after stimulus. This study was an observational study evaluating 133 women, who were grouped as follows: non-smoking pregnant women (N = 47), smoking pregnant women (N = 33), non-smoking women (N = 34), and smoking pregnant women (N = 19). The diameter of the brachial artery was measured at baseline and at 30, 60, 90 and 120 s after stimulus. The relative change of brachial artery was determined for each of these four moments. FMD measured at 60 s after stimulus was compared between the groups. The maximum FMD was observed at 60 s after cuff release in all groups. FMD was greater among non-smoking pregnant women compared to smoking pregnant women (11.50 ± 5.77 vs. 8.74 ± 4.83; p = 0.03) and also between non-smoking non-pregnant women compared to smoking non-pregnant women (10.52 ± 4.76 vs. 7.21 ± 5.57; p = 0.03). Maximum FMD was observed approximately 60 s after stimulus in all groups regardless of smoking and pregnancy status. The smoking habit seems to lead to endothelial dysfunction both in pregnant and non-pregnant women, as demonstrated by the lower FMD in smokers.

Wild brown trout affected by historical mining in the Cévennes National Park, France.

PubMed

Monna, F; Camizuli, E; Revelli, P; Biville, C; Thomas, C; Losno, R; Scheifler, R; Bruguier, O; Baron, S; Chateau, C; Ploquin, A; Alibert, P

2011-08-15

In the protected area of the Cévennes National Park (Southern France), 114 wild brown trout (Salmo trutta fario) were captured at six locations affected to different extents by historical mining and metallurgy dating from the Iron Age to Modern Times. Cadmium and lead in trout livers and muscles reflect high sediment contamination, although an age-related effect was also detected for hepatic metal concentrations. Lead isotope signatures confirm exposure to drainage from mining and metallurgical waste. Developmental instability, assessed by fluctuating asymmetry, is significantly correlated with cadmium and lead concentrations in trout tissues, suggesting that local contamination may have affected fish development. Nowadays, the area is among the least industrialized in France. However, our results show that 60% of the specimens at one site exceed EU maximum allowed cadmium or lead concentration in foodstuffs. The mining heritage should not be neglected when establishing strategies for long-term environmental management.

Apiaceae Family Plants as Low-Cost Adsorbents for the Removal of Lead Ion from Water Environment

NASA Astrophysics Data System (ADS)

Boontham, W.; Babel, S.

2017-06-01

Adsorbents prepared from the three selected plants from Apiaceae famaily commonly known as parsley, coriander and culantro were observed to remove lead from aqueous solutions. Batch experiments were conducted to study the effect of dosage, pH, contact time and agitation speed at 10 mg L-1 initial Pb(II) concentration. Results revealed that three selected plants showed high adsorption capacity for removal of lead from aqueous solutions. The maximum biosorption of Pb2+ was found to be more than 97% with 1.0 g/l dosage for all three adsorbents under optimum pH of 3-5. The adsorption equilibrium was established after about 1 hr. The equilibrium adsorption capacity of parsley and coriander were found to fit well with the Langmuir isotherm whereas the Freundlich isotherm was better fit for culantro. The studies showed that the adsorbents can be used for removing lead ions from contaminated waters.

Proton acceleration by a pair of successive ultraintense femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Ferri, J.; Senje, L.; Dalui, M.; Svensson, K.; Aurand, B.; Hansson, M.; Persson, A.; Lundh, O.; Wahlström, C.-G.; Gremillet, L.; Siminos, E.; DuBois, T. C.; Yi, L.; Martins, J. L.; Fülöp, T.

2018-04-01

We investigate the target normal sheath acceleration of protons in thin aluminum targets irradiated at a relativistic intensity by two time-separated ultrashort (35 fs) laser pulses. When the full-energy laser pulse is temporally split into two identical half-energy pulses, and using target thicknesses of 3 and 6 μm, we observe experimentally that the second half-pulse boosts the maximum energy and charge of the proton beam produced by the first half-pulse for time delays below ˜0.6-1 ps. Using two-dimensional particle-in-cell simulations, we examine the variation of the proton energy spectra with respect to the time-delay between the two pulses. We demonstrate that the expansion of the target front surface caused by the first pulse significantly enhances the hot-electron generation by the second pulse arriving after a few hundreds of fs time delay. This enhancement, however, does not suffice to further accelerate the fastest protons driven by the first pulse once three-dimensional quenching effects have set in. This implies a limit to the maximum time delay that leads to proton energy enhancement, which we theoretically determine.

An attempt to detect lameness in galloping horses by use of body-mounted inertial sensors.

PubMed

Lopes, Marco A F; Dearo, Antonio C O; Lee, Allen; Reed, Shannon K; Kramer, Joanne; Pai, P Frank; Yonezawa, Yoshiharu; Maki, Hiromitchi; Morgan, Terry L; Wilson, David A; Keegan, Kevin G

2016-10-01

OBJECTIVE To evaluate head, pelvic, and limb movement to detect lameness in galloping horses. ANIMALS 12 Thoroughbreds. PROCEDURES Movement data were collected with inertial sensors mounted on the head, pelvis, and limbs of horses trotting and galloping in a straight line before and after induction of forelimb and hind limb lameness by use of sole pressure. Successful induction of lameness was determined by measurement of asymmetric vertical head and pelvic movement during trotting. Differences in gallop strides before and after induction of lameness were evaluated with paired-sample statistical analysis and neural network training and testing. Variables included maximum, minimum, range, and time indices of vertical head and pelvic acceleration, head rotation in the sagittal plane, pelvic rotation in the frontal plane, limb contact intervals, stride durations, and limb lead preference. Difference between median standardized gallop strides for each limb lead before and after induction of lameness was calculated as the sum of squared differences at each time index and assessed with a 2-way ANOVA. RESULTS Head and pelvic acceleration and rotation, limb timing, stride duration measurements, and limb lead preference during galloping were not significantly different before and after induction of lameness in the forelimb or hind limb. Differences between limb leads before induction of lameness were similar to or greater than differences within limb leads before and after lameness induction. CONCLUSIONS AND CLINICAL RELEVANCE Galloping horses maintained asymmetry of head, pelvic, and limb motion between limb leads that was unrelated to lameness.

Long term effects of cilostazol in a dog with sick sinus syndrome.

PubMed

Kanno, Nobuyuki; Suzuki, Tomohiro

2017-06-16

Sick sinus syndrome (SSS) is a type of bradyarrhythmia that can lead to syncope. Cilostazol has been reported to be an effective treatment for human patients with SSS and other bradyarrhythmias. This report describes the successful long-term treatment with cilostazol in a dog with SSS. A nine-year old intact male Miniature Schnauzer presented with a history of syncopal episodes and unsteady gait. After cilostazol treatment, the total heart rate (HR), mean HR, and frequency of premature ventricular contractions (PVCs) increased, while the maximum HR and maximum pause time decreased. Additionally, the number of syncopal episodes decreased. The dog died suddenly, 1,418 days after the start of cilostazol treatment. Cilostazol may be a useful therapeutic agent in canines with SSS.

Customized Corneal Cross-Linking-A Mathematical Model.

PubMed

Caruso, Ciro; Epstein, Robert L; Ostacolo, Carmine; Pacente, Luigi; Troisi, Salvatore; Barbaro, Gaetano

2017-05-01

To improve the safety, reproducibility, and depth of effect of corneal cross-linking with the ultraviolet A (UV-A) exposure time and fluence customized according to the corneal thickness. Twelve human corneas were used for the experimental protocol. They were soaked using a transepithelial (EPI-ON) technique using riboflavin with the permeation enhancer vitamin E-tocopheryl polyethylene glycol succinate. The corneas were then placed on microscope slides and irradiated at 3 mW/cm for 30 minutes. The UV-A output parameters were measured to build a new equation describing the time-dependent loss of endothelial protection induced by riboflavin during cross-linking, as well as a pachymetry-dependent and exposure time-dependent prescription for input UV-A fluence. The proposed equation was used to establish graphs prescribing the maximum UV-A fluence input versus exposure time that always maintains corneal endothelium exposure below toxicity limits. Analysis modifying the Lambert-Beer law for riboflavin oxidation leads to graphs of the maximum safe level of UV-A radiation fluence versus the time applied and thickness of the treated cornea. These graphs prescribe UV-A fluence levels below 1.8 mW/cm for corneas of thickness 540 μm down to 1.2 mW/cm for corneas of thickness 350 μm. Irradiation times are typically below 15 minutes. The experimental and mathematical analyses establish the basis for graphs that prescribe maximum safe fluence and UV-A exposure time for corneas of different thicknesses. Because this clinically tested protocol specifies a corneal surface clear of shielding riboflavin on the corneal surface during UV-A irradiation, it allows for shorter UV-A irradiation time and lower fluence than in the Dresden protocol.

Temperature controlled formation of lead/acid batteries

NASA Astrophysics Data System (ADS)

Bungardt, M.

At present, standard formation programs have to accommodate the worst case. This is important, especially in respect of variations in climatic conditions. The standard must be set so that during the hottest weather periods the maximum electrolyte temperature is not exceeded. As this value is defined not only by the desired properties and the recipe of the active mass, but also by type and size of the separators and by the dimensions of the plates, general rules cannot be formulated. It is considered to be advantageous to introduce limiting data for the maximum temperature into a general formation program. The latter is defined so that under normal to good ambient conditions the shortest formation time is achieved. If required, the temperature control will reduce the currents employed in the different steps, according to need, and will extend the formation time accordingly. With computer-controlled formation, these parameters can be readily adjusted to suit each type of battery and can also be reset according to modifications in the preceding processing steps. Such a procedure ensures that: (i) the formation time is minimum under the given ambient conditions; (ii) in the event of malpractice ( e.g. actual program not fitting to size) the batteries will not be destroyed; (iii) the energy consumption is minimized (note, high electrolyte temperature leads to excess gassing). These features are incorporated in the BA/FOS-500 battery formation system developed by Digatron. The operational characteristics of this system are listed in Table 1.

Maximum likelihood estimation of protein kinetic parameters under weak assumptions from unfolding force spectroscopy experiments

NASA Astrophysics Data System (ADS)

Aioanei, Daniel; Samorì, Bruno; Brucale, Marco

2009-12-01

Single molecule force spectroscopy (SMFS) is extensively used to characterize the mechanical unfolding behavior of individual protein domains under applied force by pulling chimeric polyproteins consisting of identical tandem repeats. Constant velocity unfolding SMFS data can be employed to reconstruct the protein unfolding energy landscape and kinetics. The methods applied so far require the specification of a single stretching force increase function, either theoretically derived or experimentally inferred, which must then be assumed to accurately describe the entirety of the experimental data. The very existence of a suitable optimal force model, even in the context of a single experimental data set, is still questioned. Herein, we propose a maximum likelihood (ML) framework for the estimation of protein kinetic parameters which can accommodate all the established theoretical force increase models. Our framework does not presuppose the existence of a single force characteristic function. Rather, it can be used with a heterogeneous set of functions, each describing the protein behavior in the stretching time range leading to one rupture event. We propose a simple way of constructing such a set of functions via piecewise linear approximation of the SMFS force vs time data and we prove the suitability of the approach both with synthetic data and experimentally. Additionally, when the spontaneous unfolding rate is the only unknown parameter, we find a correction factor that eliminates the bias of the ML estimator while also reducing its variance. Finally, we investigate which of several time-constrained experiment designs leads to better estimators.

Reynolds number effect on airfoil wake structures under pitching and heaving motion

NASA Astrophysics Data System (ADS)

Kim, Kyung Chun; Karbasian, Hamidreza; ExpTENsys Team

2017-11-01

Detached Eddy Simulation (DES) and particle image velocimetry (PIV) measurements were performed to investigate the wake flow characteristics of an airfoil under pitching and heaving motion. A NACA0012 airfoil was selected for the numerical simulation and experiments were carried out in a wind tunnel and a water tunnel at Reynolds number of 15,000 and 90,000, respectively. The airfoil oscillated around an axis located 1/4 distance from the leading edge chord. Two different angles of attack, 20° and 30°, were selected with +/-10° maximum amplitude of oscillation. In order to extract the coherent flow structures from time-resolved PIV data, proper orthogonal decomposition (POD) analysis was performed on 1,000 instantaneous realisations for each condition using the method of snapshots. Vorticity contour and velocity profiles for both PIV and DES results are in good agreement for pitching and heaving motion. At high Reynolds number, 3D stream-wise vortices appeared after generating span-wise vortices. The higher maximum angle of attack allows the leading edge vortex to grow stronger and that the angle of attack appears to be more important in influencing the growth of the leading edge vortex structure than the reduced frequency. National Research Foundation of Korea (No. 2011-0030013).

An analysis of lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.915}-(Bi{sub 0.5}K{sub 0.5}){sub 0.05}Ba{sub 0.02}Sr{sub 0.015}TiO{sub 3} ceramic for efficient refrigeration and thermal energy harvesting

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

Vats, Gaurav; Vaish, Rahul, E-mail: rahul@iitmandi.ac.in; Bowen, Chris R.

This article demonstrates the colossal energy harvesting capability of a lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.915}-(Bi{sub 0.5}K{sub 0.5}){sub 0.05}Ba{sub 0.02}Sr{sub 0.015}TiO{sub 3} ceramic using the Olsen cycle. The maximum harvestable energy density estimated for this system is found to be 1523 J/L (1523 kJ/m{sup 3}) where the results are presented for extreme ambient conditions of 20–160 °C and electric fields of 0.1–4 MV/m. This estimated energy density is 1.7 times higher than the maximum reported to date for the lanthanum-doped lead zirconate titanate (thin film) system. Moreover, this study introduces a generalized and effective solid state refrigeration cycle in contrast to the ferroelectric Ericsonmore » refrigeration cycle. The cycle is based on a temperature induced polarization change on application of an unipolar electric field to ferroelectric ceramics.« less

Lead extraction from Cathode Ray Tube (CRT) funnel glass: Reaction mechanisms in thermal reduction with addition of carbon (C).

PubMed

Lu, Xingwen; Ning, Xun-An; Chen, Da; Chuang, Kui-Hao; Shih, Kaimin; Wang, Fei

2018-06-01

This study quantitatively determined the extraction of lead from CRT funnel glass and examined the mechanisms of thermally reducing lead in the products of sintering Pb-glass with carbon in the pre-heated furnace. The experimentally derived results indicate that a 90.3 wt% lead extraction efficiency can be achieved with 20 wt% of C addition at 950 °C for 3 min under air. The formation of viscous semi-liquid glass blocked the oxygen supply between the interaction of C and Pb-glass, and was highly effective for the extraction of metallic Pb. A maximum of 87.3% lead recover was obtained with a C to Na 2 CO 3 ratio of 1/3 at 1200 °C. The decrease of C/Na 2 CO 3 ratio enhanced the metallic lead recovery by increasing the glass viscosity for effective sedimentation of metallic lead in the bottom. However, with the further increase of temperature and treatment time, re-vitrification of lead back to silicate-glass matrix was detected in both Pb-glass/C and Pb-glass/C/Na 2 CO 3 systems. The findings indicated that with proper controls, using C as an inexpensive reagent can effectively reduce treatment time and energy, which is crucial to a waste-to-resource technology for economically recovering lead from the waste CRT glass. Copyright © 2018 Elsevier Ltd. All rights reserved.

40 CFR 471.101 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

....3 pH (1) (1) 1 Within the range of 7.5 to 10.0 at all times. (b) Sizing spent emulsion. Subpart J...) Sawing or grinding spent emulsion. Subpart J—BPT Pollutant or pollutant property Maximum for any 1 day... ground with emulsion Copper 0.035 0.018 Cyanide 0.005 0.002 Lead 0.008 0.004 Oil and grease 0.362 0.217...

Seasonal prediction and predictability of Eurasian spring snow water equivalent in NCEP Climate Forecast System version 2 reforecasts

NASA Astrophysics Data System (ADS)

He, Qiong; Zuo, Zhiyan; Zhang, Renhe; Zhang, Ruonan

2018-01-01

The spring snow water equivalent (SWE) over Eurasia plays an important role in East Asian and Indian monsoon rainfall. This study evaluates the seasonal prediction capability of NCEP Climate Forecast System version 2 (CFSv2) retrospective forecasts (1983-2010) for the Eurasian spring SWE. The results demonstrate that CFSv2 is able to represent the climatological distribution of the observed Eurasian spring SWE with a lead time of 1-3 months, with the maximum SWE occurring over western Siberia and Northeastern Europe. For a longer lead time, the SWE is exaggerated in CFSv2 because the start of snow ablation in CFSv2 lags behind that of the observation, and the simulated snowmelt rate is less than that in the observation. Generally, CFSv2 can simulate the interannual variations of the Eurasian spring SWE 1-5 months ahead of time but with an exaggerated magnitude. Additionally, the downtrend in CFSv2 is also overestimated. Because the initial conditions (ICs) are related to the corresponding simulation results significantly, the robust interannual variability and the downtrend in the ICs are most likely the causes for these biases. Moreover, CFSv2 exhibits a high potential predictability for the Eurasian spring SWE, especially the spring SWE over Siberia, with a lead time of 1-5 months. For forecasts with lead times longer than 5 months, the model predictability gradually decreases mainly due to the rapid decrease in the model signal.

Feedback coupling in dynamical systems

NASA Astrophysics Data System (ADS)

Trimper, Steffen; Zabrocki, Knud

2003-05-01

Different evolution models are considered with feedback-couplings. In particular, we study the Lotka-Volterra system under the influence of a cumulative term, the Ginzburg-Landau model with a convolution memory term and chemical rate equations with time delay. The memory leads to a modified dynamical behavior. In case of a positive coupling the generalized Lotka-Volterra system exhibits a maximum gain achieved after a finite time, but the population will die out in the long time limit. In the opposite case, the time evolution is terminated in a crash. Due to the nonlinear feedback coupling the two branches of a bistable model are controlled by the the strength and the sign of the memory. For a negative coupling the system is able to switch over between both branches of the stationary solution. The dynamics of the system is further controlled by the initial condition. The diffusion-limited reaction is likewise studied in case the reacting entities are not available simultaneously. Whereas for an external feedback the dynamics is altered, but the stationary solution remain unchanged, a self-organized internal feedback leads to a time persistent solution.

Metals sorption from aqueous solutions by Kluyveromyces marxianus: process optimization, equilibrium modeling and chemical characterization.

PubMed

Pal, Rama; Tewari, Saumyata; Rai, Jai P N

2009-10-01

The dead Kluyveromyces marxianus biomass, a fermentation industry waste, was used to explore its sorption potential for lead, mercury, arsenic, cobalt, and cadmium as a function of pH, biosorbent dosage, contact time, agitation speed, and initial metal concentration. The equilibrium data fitted the Langmuir model better for cobalt and cadmium, but Freundlich isotherm for all metals tested. At equilibrium, the maximum uptake capacity (Qmax) was highest for lead followed by mercury, arsenic, cobalt, and cadmium. The RL values ranged between 0-1, indicating favorable sorption of all test metals by the biosorbent. The maximum Kf value of Pb showed its efficient removal from the solution. However, multi-metal analysis depicted that sorption of all metals decreased except Pb. The potentiometric titration of biosorbent revealed the presence of functional groups viz. amines, carboxylic acids, phosphates, and sulfhydryl group involved in heavy metal sorption. The extent of contribution of functional groups and lipids to biosorption was in the order: carboxylic>lipids>amines>phosphates. Blocking of sulfhydryl group did not have any significant effect on metal sorption.

Endocrine and reproductive dysfunction in men associated with occupational inorganic lead intoxication

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

Cullen, M.R.; Kayne, R.D.; Robins, J.M.

In an attempt to define a postulated effect of lead on male endocrine function, seven men with symptomatic occupational lead intoxication (maximum whole blood lead levels 66-139 ..mu..g/dl) underwent in-patient endocrine evaluation at the time of diagnosis. Defects in thyroid function probably of central origin, were present in three patients. Six patients had subnormal glucocorticoid production measured by 24-hr urinary 17-hydroxy-corticosteroids and plasma cortisol responses to vasopressin- and/or insulin-induced hypoglycemia. Although serum testosterone concentration was normal in six patients, five had defects in spermatogenesis, including two with ologospermia and two with azoospermia. Repeat examinations after chelation therapy showed only partialmore » improvement. It is concluded that heavy occupational exposure to lead, sufficient to cause clinical poisoning, may be associated with diffuse disturbances of endocrine and reproductive functions in men which are not rapidly reversible with standard treatment. Since men without overt poisoning have not been studied, these results cannot yet be included as sequelae of low-dose exposures.« less

Hypoxia attenuates the respiratory response to injection of substance P into the nucleus of the solitary tract of the rat.

PubMed

Mazzone, S B; Hinrichsen, C F; Geraghty, D P

1998-10-30

Prolonged or repetitive bouts of hypoxia may desensitize the brain stem respiratory centres leading to reduced stimulation of ventilation. We investigated the possible involvement of changes in the sensitivity of the commissural nucleus of the solitary tract (cNTS) to the tachykinin peptide, substance P (SP). Urethane-anaesthetised rats were allowed to breath room air (normoxic) or subjected to four, 30 s bouts of hypoxia (10% O2/90% N2) prior to the injection of SP (750 pmol) into the cNTS. In normoxic rats (n = 5), SP produced a fall in frequency (f, 88+/-4% control) after 4 min and a maximum rise in tidal volume (VT) after 6 min (138+/-10% control) leading to an overall increase in minute ventilation (VE, maximum, 127+/-12% control after 2 min). In rats (n = 5) exposed to four bouts of hypoxia and allowed to recover for 10 min, injection of SP produced a similar fall in f but a delayed and significantly (P < 0.001) reduced VT (maximum after 10 min, 110+/-1% control) and hence, VE response (104+/-3% control). Sixty min after hypoxia, the f, VT and VE responses to SP were identical to those of normoxic rats. These data suggest that hypoxia desensitizes SP receptors in the cNTS and this may partly explain why the respiratory response to hypoxia declines over time.

Spatial correlation in precipitation trends in the Brazilian Amazon

NASA Astrophysics Data System (ADS)

Buarque, Diogo Costa; Clarke, Robin T.; Mendes, Carlos Andre Bulhoes

2010-06-01

A geostatistical analysis of variables derived from Amazon daily precipitation records (trends in annual precipitation totals, trends in annual maximum precipitation accumulated over 1-5 days, trend in length of dry spell, trend in number of wet days per year) gave results that are consistent with those previously reported. Averaged over the Brazilian Amazon region as a whole, trends in annual maximum precipitations were slightly negative, the trend in the length of dry spell was slightly positive, and the trend in the number of wet days in the year was slightly negative. For trends in annual maximum precipitation accumulated over 1-5 days, spatial correlation between trends was found to extend up to a distance equivalent to at least half a degree of latitude or longitude, with some evidence of anisotropic correlation. Time trends in annual precipitation were found to be spatially correlated up to at least ten degrees of separation, in both W-E and S-N directions. Anisotropic spatial correlation was strongly evident in time trends in length of dry spell with much stronger evidence of spatial correlation in the W-E direction, extending up to at least five degrees of separation, than in the S-N. Because the time trends analyzed are shown to be spatially correlated, it is argued that methods at present widely used to test the statistical significance of climate trends over time lead to erroneous conclusions if spatial correlation is ignored, because records from different sites are assumed to be statistically independent.

Graphene oxide as a photocatalytic material

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

Krishnamoorthy, Karthikeyan; Mohan, Rajneesh; Kim, S.-J.

2011-06-13

The photocatalytic characteristics of graphene oxide (GO) nanostructures synthesized by modified Hummer's method were investigated by measuring reduction rate of resazurin (RZ) into resorufin (RF) as a function of UV irradiation time. The progress of the photocatalytic reaction was monitored by change in color from blue (RZ) into pink (RF) followed by absorption spectra. It exhibited excellent photocatalytic activity, leading to the reduction of RZ in UV irradiation. The fitting of absorbance maximum versus time suggests that the reduction of RZ follow the pseudo first-order reaction kinetics. These results indicate that GO have great potential for use as a photocatalyst.

Examining a scaled dynamical system of telomere shortening

NASA Astrophysics Data System (ADS)

Cyrenne, Benoit M.; Gooding, Robert J.

2015-02-01

A model of telomere dynamics is proposed and examined. Our model, which extends a previously introduced model that incorporates stem cells as progenitors of new cells, imposes the Hayflick limit, the maximum number of cell divisions that are possible. This new model leads to cell populations for which the average telomere length is not necessarily a monotonically decreasing function of time, in contrast to previously published models. We provide a phase diagram indicating where such results would be expected via the introduction of scaled populations, rate constants and time. The application of this model to available leukocyte baboon data is discussed.

Effects of variability in probable maximum precipitation patterns on flood losses

NASA Astrophysics Data System (ADS)

Zischg, Andreas Paul; Felder, Guido; Weingartner, Rolf; Quinn, Niall; Coxon, Gemma; Neal, Jeffrey; Freer, Jim; Bates, Paul

2018-05-01

The assessment of the impacts of extreme floods is important for dealing with residual risk, particularly for critical infrastructure management and for insurance purposes. Thus, modelling of the probable maximum flood (PMF) from probable maximum precipitation (PMP) by coupling hydrological and hydraulic models has gained interest in recent years. Herein, we examine whether variability in precipitation patterns exceeds or is below selected uncertainty factors in flood loss estimation and if the flood losses within a river basin are related to the probable maximum discharge at the basin outlet. We developed a model experiment with an ensemble of probable maximum precipitation scenarios created by Monte Carlo simulations. For each rainfall pattern, we computed the flood losses with a model chain and benchmarked the effects of variability in rainfall distribution with other model uncertainties. The results show that flood losses vary considerably within the river basin and depend on the timing and superimposition of the flood peaks from the basin's sub-catchments. In addition to the flood hazard component, the other components of flood risk, exposure, and vulnerability contribute remarkably to the overall variability. This leads to the conclusion that the estimation of the probable maximum expectable flood losses in a river basin should not be based exclusively on the PMF. Consequently, the basin-specific sensitivities to different precipitation patterns and the spatial organization of the settlements within the river basin need to be considered in the analyses of probable maximum flood losses.

Lifespan development of the bilateral deficit in a simple reaction time task.

PubMed

Vieluf, Solveig; Aschersleben, Gisa; Panzer, Stefan

2017-04-01

Performing an action at a maximum speed or with a maximum strength simultaneously with two limbs leads to a lower performance than the sum of unimanual performances. This phenomenon is known as bilateral deficit. There is some evidence that the bilateral deficit changes over the lifespan, in a way that children and older adults show lower deficits than young adults. Inverse developmental changes of childrens' and older adults' brain structures connecting both hemispheres, i.e., the corpus callosum, might importantly contribute to this phenomenon. The seemingly similar developments have been observed with different experimental protocols in the different age groups, respectively. To test for similarities and differences in changes of the bilateral deficit at critical periods of the lifespan development of bimanual actions, children, young adults, and older adults performed a simple reaction time task uni- and bimanually. Reaction times and the resulting bilateral deficit, as well as reaction time variability were analyzed. As expected, reaction times were different for the young adults between the uni- and the bimanual task. Children and older adults performed both conditions with similar reaction times. However, a difference in the direction of the %bilateral deficit occurred between the two age groups. The findings demonstrated an absence of the bilateral deficit for children, but not for younger and older adults.

COSMIC RADIATION AND TUBERCULOSIS. IV. INFLUENCE OF COSMIC RADIATION ON TUBERCULOSIS AT HIGH ALTITUDE (3,130 M) AND AT SEA-LEVEL

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

Ong, S.G.

1964-01-01

At high altitude (3,130 m) tuberculous mice exposed to cosmic radiation under 10 cm of lead showed significantly greater mean survival time and a significantly greater number of survivors than tuberculous mice exposed to direct cosmic radiation. Tuberculous mice exposed to cosmic radiation at high altitude under 10 cm of lead showed a significantly greater mean survival time than tuberculous mice kept at sea level, exposed to direct cosmic radiation, and to cosmic radiation under 1, 2, and 10 cm of lead. The correlation analysis shows that a decreas in lung lesions is associated with an increase in survival time.more » The decrease in lung lesions is associated with an enlargement of the spleen. At high altitude the female showed a significantly greater number of survivors than the male. At sea level no significant difference was observed. On the average the female showed a significantly greater number of survivors. The beneficial effect of daylight with ultraviolet light on tuberculous mice was manifested in a lower maximum of mortality and in a significant decrease of lung and spleen lesions. (auth)« less

[Effect of anthropotechnogenic chemical factors on formation of somatotypes in children and adolescents of school age].

PubMed

Iudin, G V; Osipova, M I; Eremin, G A; Stroĭkova, S B

2003-01-01

This research was done to study the dynamics of a process of constitutional types formation in 163 schoolboys and 181 schoolgirls, who live and study in various regions of the city of Ivanovo which are characterized by a different degree of environmental pollution with heavy metal salts and lead in particular. To define the constitutional types, the method of V.G. Shtefko and A.D. Ostrovsky (1929) was used. It was demonstrated that environmental pollution with heavy metal salts, the absorbed dose of which 3 times exceeded the maximum permissible dose, lead to the delay of somatotype differentiation in children and adolescents, which was more pronounced in schoolboys than in schoolgirls.

Photon-induced positron annihilation lifetime spectroscopy using ultrashort laser-Compton-scattered gamma-ray pulses

NASA Astrophysics Data System (ADS)

Taira, Y.; Toyokawa, H.; Kuroda, R.; Yamamoto, N.; Adachi, M.; Tanaka, S.; Katoh, M.

2013-05-01

High-energy ultrashort gamma-ray pulses can be generated via laser Compton scattering with 90° collisions at the UVSOR-II electron storage ring. As an applied study of ultrashort gamma-ray pulses, a new photon-induced positron annihilation lifetime spectroscopy approach has been developed. Ultrashort gamma-ray pulses with a maximum energy of 6.6 MeV and pulse width of 2.2 ps created positrons throughout bulk lead via pair production. Annihilation gamma rays were detected by a BaF2 scintillator mounted on a photomultiplier tube. A positron lifetime spectrum was obtained by measuring the time difference between the RF frequency of the electron storage ring and the detection time of the annihilation gamma rays. We calculated the response of the BaF2 scintillator and the time jitter caused by the variation in the total path length of the ultrashort gamma-ray pulses, annihilation gamma rays, and scintillation light using a Monte Carlo simulation code. The positron lifetime for bulk lead was successfully measured.

Expiratory and phonation times as measures of disease severity in patients with Multiple Sclerosis. A case-control study.

PubMed

Nordio, Sara; Bernitsas, Evanthia; Meneghello, Francesca; Palmer, Katie; Stabile, Maria Rosaria; Dipietro, Laura; Di Stadio, Arianna

2018-04-21

Speech disorders are common in patients with Multiple Sclerosis (MS). They can be assessed with several methods, which are however expensive, complex, and not easily accessible to physicians during routine clinic visits. This study aimed at measuring maximum phonation times, maximum expiratory times, and articulation abilities scores in patients with MS compared to healthy subjects and at investigating if any of these parameters could be used as a measure of MS progression. 50 MS patients and 50 gender- and age-matched healthy controls were enrolled in the study. Maximum expiratory times and maximum phonation times were collected from both groups. Articulation abilities were evaluated using the articulation subtest from the Fussi assessment (dysarthria scores). MS patients were evaluated with the Expanded Disability Status Scale (EDSS). Correlations between EDSS scores and maximum expiratory times, maximum phonation times, and dysarthria scores were calculated. EDSS scores of MS patients ranged from 4.5 to 7.5. In MS patients, maximum expiratory times, maximum phonation times, and dysarthria scores were significantly altered compared to healthy controls. Moreover, the EDSS scores were correlated with the maximum expiratory times; the maximum expiratory times were correlated with the maximum phonation times, and the maximum phonation times were correlated with the dysarthria scores. As the expiratory times were significantly correlated with the EDSS scores, they could be used to measure the severity of MS and to monitor its progression. Copyright © 2018 Elsevier B.V. All rights reserved.

Time-of-travel and dispersion studies, Lehigh River, Francis E. Walter Lake to Easton, Pennsylvania

USGS Publications Warehouse

Kauffman, C.D.

1983-01-01

Results of time-of-travel and dispersion studies are presented for the 77.0 mile reach of the Lehigh River from Francis E. Walter Lake to Easton, Pennsylvania. Rhodamine WT dye was injected at several points for a variety of several common flow conditions and its downstream travel was monitored at a number of downstream points by means of a fluorometer. Time-of-travel data have been related to stream discharge, distance along the river channel and dispersion. If 2.205 pounds of a conservative water soluble contaminant were accidentally spilled into the Lehigh River at Penn Haven Junction at Black Creek 6.09 miles downstream from Rockport, Pennsylvania, when the discharge at Walnutport, Pennsylvania, was 600 cubic feet per second, the leading edge, peak, and trailing edge of the contaminant would arrive 31.6 miles downstream at the Northhampton, Pennsylvania, water intakes 45, 54, and 66 hours later, respectively. The maximum concentration expected at the intakes would be about 1.450 micrograms per liter. From data and relations presented, time-of-travel and maximum concentration estimates can be made for any two points within the reach. (USGS)

[Bidens maximowicziana's adsorption ability and remediation potential to lead in soils].

PubMed

Wang, Hong-qi; Li, Hua; Lu, Si-jin

2005-11-01

Bidens maximowicziana's adsorption ability and remediation potential to lead were studied. The results show: (1) The Bidens maximowicziana has a strong adsorption to lead, the concentration of lead in plants increased linearly with the increase of lead concentration in soil. Then maximum concentration was 1509.3 mg x kg(-1) in roots and 2164.7 mg x kg(-1) in shoots when lead concentration in soil was 2000 mg x L(-1); (2) The lead concentration distribution order in the Bidens maximorwicziana is: leaf>stem>root>seed, which indicate that Bidens maximowicziana has a strong ability to transfer lead; (3) Uptaking ability differes in different vegetal periods. Maximum lead uptaking rate occured in the period of blooming for 40-60 days, in which daily uptake capacity was 15.81 mg x (kg x d)(-1) in roots and 19.83 mg x (kg x d)(-1) in shoots respectively. It can be concluded that Bidens maximowicziana appeares to be a moderate Pb accumulator making it suitable for phytoremediation of Pb contaminated soil.

40 CFR 421.252 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and... monthly average mg/troy ounce of silver reduced in solution Lead 0.168 0.080 Mercury 0.100 0.040 Silver 0... property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold refined electrolytically...

40 CFR 471.102 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Copper 9.58 5.04 Cyanide 1.46 0.605 Lead 2.12 1.01 (b) Sizing spent emulsions. Subpart J—BAT Pollutant or... grinding spent emulsions. Subpart J—BAT Pollutant or pollutant property Maximum for any 1 day Maximum for... emulsions Copper 0.0035 0.018 Cyanide 0.005 0.002 Lead 0.008 0.004 (h) Sawing or grinding contact cooling...

40 CFR 471.102 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Copper 9.58 5.04 Cyanide 1.46 0.605 Lead 2.12 1.01 (b) Sizing spent emulsions. Subpart J—BAT Pollutant or... grinding spent emulsions. Subpart J—BAT Pollutant or pollutant property Maximum for any 1 day Maximum for... emulsions Copper 0.0035 0.018 Cyanide 0.005 0.002 Lead 0.008 0.004 (h) Sawing or grinding contact cooling...

40 CFR 471.102 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Copper 9.58 5.04 Cyanide 1.46 0.605 Lead 2.12 1.01 (b) Sizing spent emulsions. Subpart J—BAT Pollutant or... grinding spent emulsions. Subpart J—BAT Pollutant or pollutant property Maximum for any 1 day Maximum for... emulsions Copper 0.0035 0.018 Cyanide 0.005 0.002 Lead 0.008 0.004 (h) Sawing or grinding contact cooling...

A Smoking Gun for Methane Hydrate Release During the Paleocene-Eocene Thermal Maximum

NASA Astrophysics Data System (ADS)

Frieling, J.; Peterse, F.; Lunt, D. J.; Bohaty, S. M.; S Sinninghe Damsté, J.; Reichart, G. J.; Sluijs, A.

2016-12-01

The Paleocene-Eocene Thermal Maximum (PETM; 56 Ma) was a period of rapid 4-5ºC global warming and a global negative carbon isotope excursion (CIE) of 3-4.5‰, signaling the input of at least 1500 Gt of δ13C-depleted carbon into the ocean-atmosphere system. Methane from submarine hydrates has long been proposed as a carbon source, but direct and indirect evidence is lacking. We generated a new high-resolution TEX86 and δ13C record from Ocean Drilling Program Site 959 in the eastern tropical Atlantic and find that initial warming preceded the PETM CIE by 10 kyr. Moreover, time-shifted cross-correlations on these new and published temperature-δ13C data imply that substantial (2-3 °C) warming lead 13C-depleted carbon injection by an average of 2-3 kyr globally. Finally, a data compilation shows that global burial fluxes of biogenic Ba approximately doubled across all depths of the ocean studied, which on PETM time scales can only be explained by significant Ba addition to the oceans. Submarine hydrates are Ba-rich and require warming to dissociate. The simplest explanation for the temperature lead and Ba addition to the ocean is that methane hydrate dissociated as a response to initial warming and acted as a positive carbon cycle feedback during the PETM.

Potential benefits of triethylamine as n-electron donor in the estimation of forskolin by electronic absorption and emission spectroscopy

NASA Astrophysics Data System (ADS)

Raju, Gajula; Ram Reddy, A.

2016-02-01

Diterpenoid forskolin was isolated from Coleus forskolii. The electronic absorption and emission studies of forskolin were investigated in various solvents with an aim to improve its detection limits. The two chromophores present in the diterpenoid are not conjugated leading to the poor absorption and emission of UV light. The absorption and fluorescence spectra were solvent specific. In the presence of a monodentate ligand, triethylamine the detection of forskolin is improved by 3.63 times in ethanol with the fluorescence method and 3.36 times in DMSO by the absorption spectral method. The longer wavelength absorption maximum is blue shifted while the lower energy fluorescence maximum is red shifted in the presence of triethylamine. From the wavelength of fluorescence maxima of the exciplex formed between excited forskolin and triethylamine it is concluded that the order of reactivity of hydroxyl groups in the excited state forskolin is in the reverse order to that of the order of the reactivity of hydroxyl groups in its ground state.

Acidic processing of hemicellulosic saccharides from pine wood: product distribution and kinetic modeling.

PubMed

Rivas, Sandra; González-Muñoz, María Jesús; Santos, Valentín; Parajó, Juan Carlos

2014-06-01

Water soluble compounds were removed from Pinus pinaster wood by a mild aqueous extraction, and the treated wood was subjected to hydrothermal processing to convert most hemicelluloses into soluble saccharides (including low molecular weight polymers, oligomers and monosaccharides). The liquid phase containing hemicellulose-derived saccharides was acidified with sulfuric acid and heated up to 130-250°C to obtain furans and levulinic acid as major products. The concentration profiles of the major compounds participating in the reactions were interpreted by a kinetic model. A maximum conversion of pentoses into furfural near 80% was predicted at high temperature and short time, conditions leading to 24% conversion of hexoses into HMF. Production of levulinic acid was favored at low temperatures. Maximum molar conversion of hexoses into levulinic acid (66.7% at 130°C) needed a long reaction time (235 h). A value of 53.0% can be achieved at 170°C after 5 h. Copyright © 2014 Elsevier Ltd. All rights reserved.

Co-precipitation synthesis of nanostructured Cu3SbSe4 and its Sn-doped sample with high thermoelectric performance.

PubMed

Li, Di; Li, Rui; Qin, Xiao-Ying; Song, Chun-Jun; Xin, Hong-Xing; Wang, Ling; Zhang, Jian; Guo, Guang-lei; Zou, Tian-Hua; Liu, Yong-Fei; Zhu, Xiao-Guang

2014-01-28

Large-scale fabrication of nanostructured Cu3SbSe4 and its Sn-doped sample Cu3Sb0.98Sn0.02Se4 through a low-temperature co-precipitation route is reported. The effects of hot-pressing temperatures, time and Sn doping on the thermoelectric properties of Cu3SbSe4 are explored. The maximum figure of merit ZTmax obtained here reaches 0.62 for the un-doped Cu3SbSe4, which is three times as large as that of Cu3SbSe4 synthesized by the fusion method. Due to the ameliorated power factor by optimized carrier concentration and the reduced lattice thermal conductivity by enhanced phonon scattering at grain interfaces, Sn doping leads to an improvement of thermoelectric performance as compared to Cu3SbSe4. The maximum ZT for Cu3Sb0.98Sn0.02Se4 is 1.05 in this work, which is 50% larger than the largest value reported.

Optimization principles and the figure of merit for triboelectric generators.

PubMed

Peng, Jun; Kang, Stephen Dongmin; Snyder, G Jeffrey

2017-12-01

Energy harvesting with triboelectric nanogenerators is a burgeoning field, with a growing portfolio of creative application schemes attracting much interest. Although power generation capabilities and its optimization are one of the most important subjects, a satisfactory elemental model that illustrates the basic principles and sets the optimization guideline remains elusive. We use a simple model to clarify how the energy generation mechanism is electrostatic induction but with a time-varying character that makes the optimal matching for power generation more restrictive. By combining multiple parameters into dimensionless variables, we pinpoint the optimum condition with only two independent parameters, leading to predictions of the maximum limit of power density, which allows us to derive the triboelectric material and device figure of merit. We reveal the importance of optimizing device capacitance, not only load resistance, and minimizing the impact of parasitic capacitance. Optimized capacitances can lead to an overall increase in power density of more than 10 times.

Enhanced Removal of Lead by Chemically and Biologically Treated Carbonaceous Materials

PubMed Central

Mahmoud, Mohamed E.; Osman, Maher M.; Ahmed, Somia B.; Abdel-Fattah, Tarek M.

2012-01-01

Hybrid sorbents and biosorbents were synthesized via chemical and biological treatment of active carbon by simple and direct redox reaction followed by surface loading of baker's yeast. Surface functionality and morphology of chemically and biologically modified sorbents and biosorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Hybrid carbonaceous sorbents and biosorbents were characterized by excellent efficiency and superiority toward lead(II) sorption compared to blank active carbon providing a maximum sorption capacity of lead(II) ion as 500 μmol g−1. Sorption processes of lead(II) by these hybrid materials were investigated under the influence of several controlling parameters such as pH, contact time, mass of sorbent and biosorbent, lead(II) concentration, and foreign ions. Lead(II) sorption mechanisms were found to obey the Langmuir and BET isotherm models. The potential applications of chemically and biologically modified-active carbonaceous materials for removal and extraction of lead from real water matrices were also studied via a double-stage microcolumn technique. The results of this study were found to denote to superior recovery values of lead (95.0–99.0 ± 3.0–5.0%) by various carbonaceous-modified-bakers yeast biosorbents. PMID:22629157

Bracketing mid-pliocene sea surface temperature: maximum and minimum possible warming

USGS Publications Warehouse

Dowsett, Harry

2004-01-01

Estimates of sea surface temperature (SST) from ocean cores reveal a warm phase of the Pliocene between about 3.3 and 3.0 Mega-annums (Ma). Pollen records from land based cores and sections, although not as well dated, also show evidence for a warmer climate at about the same time. Increased greenhouse forcing and altered ocean heat transport is the leading candidates for the underlying cause of Pliocene global warmth. However, despite being a period of global warmth, there exists considerable variability within this interval. Two new SST reconstructions have been created to provide a climatological error bar for warm peak phases of the Pliocene. These data represent the maximum and minimum possible warming recorded within the 3.3 to 3.0 Ma interval.

Long term effects of cilostazol in a dog with sick sinus syndrome

PubMed Central

KANNO, Nobuyuki; SUZUKI, Tomohiro

2017-01-01

Sick sinus syndrome (SSS) is a type of bradyarrhythmia that can lead to syncope. Cilostazol has been reported to be an effective treatment for human patients with SSS and other bradyarrhythmias. This report describes the successful long-term treatment with cilostazol in a dog with SSS. A nine-year old intact male Miniature Schnauzer presented with a history of syncopal episodes and unsteady gait. After cilostazol treatment, the total heart rate (HR), mean HR, and frequency of premature ventricular contractions (PVCs) increased, while the maximum HR and maximum pause time decreased. Additionally, the number of syncopal episodes decreased. The dog died suddenly, 1,418 days after the start of cilostazol treatment. Cilostazol may be a useful therapeutic agent in canines with SSS. PMID:28458273

Simulating extreme low-discharge events for the Rhine using a stochastic model

NASA Astrophysics Data System (ADS)

Macian-Sorribes, Hector; Mens, Marjolein; Schasfoort, Femke; Diermanse, Ferdinand; Pulido-Velazquez, Manuel

2017-04-01

The specific features of hydrological droughts make them more difficult to be analysed than other water-related phenomena: longer time scales (months to several years) so less historical events are available, and the drought severity and associate damage depends on a combination of variables with no clear prevalence (e.g., total water deficit, maximum deficit and duration). As part of drought risk analysis, which aims to provide insight into the variability of hydrological conditions and associated socio-economic impacts, long synthetic time series should therefore be developed. In this contribution, we increase the length of the available inflow time series using stochastic autoregressive modelling. This enhancement could improve the characterization of the extreme range and can define extreme droughts with similar periods of return but different patterns that can lead to distinctly different damages. The methodology consists of: 1) fitting an autoregressive model (AR, ARMA…) to the available records; 2) generating extended time series (thousands of years); 3) performing a frequency analysis with different characteristic variables (total, deficit, maximum deficit and so on); and 4) selecting extreme drought events associated with different characteristic variables and return periods. The methodology was applied to the Rhine river discharge at location Lobith, where the Rhine enters The Netherlands. A monthly ARMA(1,1) autoregressive model with seasonally varying parameters was fitted and successfully validated to the historical records available since year 1901. The maximum monthly deficit with respect to a threshold value of 1800 m3/s and the average discharge for a given time span in m3/s were chosen as indicators to identify drought periods. A synthetic series of 10,000 years of discharges was generated using the validated ARMA model. Two time spans were considered in the analysis: the whole calendar year and the half-year period between April and September (the summer half year, where water demands are highest). Frequency analysis was performed for both indicators and time spans for the generated time series and the historical records. The comparison between observed and generated series showed that the ARMA model provides a good reproduction of the maximum deficits and total discharges, especially for the summer half-year period. The resulting synthetic series are therefore considered credible. These synthetic series, with its wealth of information, can then be used as inputs for the damage assessment models, together with information on precipitation deficits, in order to estimate the risk that lower inflows can have on the urban, the agricultural, the shipping sector and so on. This will help in associating economic losses and periods of return, as well as for estimating how droughts with similar periods of return but different patterns can lead to different damages. ACKNOWLEDGEMENT This study has been supported by the European Union's Horizon 2020 research and innovation programme under the IMPREX project (grant agreement no: 641.811), and by the Climate-KIC Pioneers into Practice Program supported by the European Union's EIT.

Evidence for sub-Chandrasekhar-mass progenitors of Type Ia supernovae at the faint end of the width-luminosity relation

NASA Astrophysics Data System (ADS)

Blondin, Stéphane; Dessart, Luc; Hillier, D. John; Khokhlov, Alexei M.

2017-09-01

The faster light-curve evolution of low-luminosity Type Ia supernovae (SNe Ia) suggests that they could result from the explosion of white dwarf (WD) progenitors below the Chandrasekhar mass (MCh). Here we present 1D non-local thermodynamic equilibrium time-dependent radiative transfer simulations of pure central detonations of carbon-oxygen WDs with a mass (Mtot) between 0.88 and 1.15 M⊙ and a 56Ni yield between 0.08 and 0.84 M⊙. Their lower ejecta density compared to MCh models results in a more rapid increase of the luminosity at early times and an enhanced γ-ray escape fraction past maximum light. Consequently, their bolometric light curves display shorter rise times and larger post-maximum decline rates. Moreover, the higher M(56Ni)/Mtot ratio at a given 56Ni mass enhances the temperature and ionization level in the spectrum-formation region for the less luminous models, giving rise to bluer colours at maximum light and a faster post-maximum evolution of the B - V colour. For sub-MCh models fainter than MB ≈ -18.5 mag at peak, the greater bolometric decline and faster colour evolution lead to a larger B-band post-maximum decline rate, ΔM15(B). In particular, all of our previously published MCh models (standard and pulsational delayed detonations) are confined to ΔM15(B) < 1.4 mag, while the sub-MCh models with Mtot ≲ 1 M⊙ extend beyond this limit to ΔM15(B) ≈ 1.65 mag for a peak MB ≈ -17 mag, in better agreement with the observed width-luminosity relation (WLR). Regardless of the precise ignition mechanism, these simulations suggest that fast-declining SNe Ia at the faint end of the WLR could result from the explosion of WDs whose mass is significantly below the Chandrasekhar limit.

Sorption of lead from aqueous solution by chemically modified carbon adsorbents.

PubMed

Nadeem, Muhammad; Mahmood, A; Shahid, S A; Shah, S S; Khalid, A M; McKay, G

2006-12-01

An indigenously prepared, steam activated and chemically modified carbon from husk and pods of Moringa oleifera (M. oleifera), an agricultural waste, was comparatively examined as an adsorbent for the removal of lead from aqueous solutions. Studies were conducted as a function of contact time, initial metal concentration, dose of adsorbent, agitation speed, particle size and pH. Maximum uptake capacities were found to be, 98.89, 96.58, 91.8, 88.63, 79.43% for cetyltrimethyl ammonium bromide (CTAB), phosphoric, sulfuric, hydrochloric acid treated and untreated carbon adsorbents, respectively. Bangham, pseudo-first- and second-order, intra-particle diffusion equations were implemented to express the sorption mechanism by utilized adsorbents. Adsorption rate of lead ions was found to be considerably faster for chemically modified adsorbents than unmodified. The results of adsorption were fitted to both the Langmuir and Freundlich models. Satisfactory agreement between the metal uptake capacities by the adsorbents at different time intervals was expressed by the correlation coefficient (R(2)). The Langmuir model represented the sorption process better than the Freundlich one, with R(2) values ranging from 0.994 to 0.998.

40 CFR 421.73 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... produced Lead .000 .000 Zinc .000 .000 (g) Subpart G—Hard Lead Refining Slag Granulation. BAT Effluent... per billion pounds) of hard lead produced Lead .000 .000 Zinc .000 .000 (h) Subpart G—Hard Lead... any 1 day Maximum for monthly average mg/kkg (pounds per billion pounds) of hard lead produced Lead...

40 CFR 421.73 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... produced Lead .000 .000 Zinc .000 .000 (g) Subpart G—Hard Lead Refining Slag Granulation. BAT Effluent... per billion pounds) of hard lead produced Lead .000 .000 Zinc .000 .000 (h) Subpart G—Hard Lead... any 1 day Maximum for monthly average mg/kkg (pounds per billion pounds) of hard lead produced Lead...

The Influence of Mesh Density on the Impact Response of a Shuttle Leading-Edge Panel Finite Element Simulation

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.; Lyle, Karen H.; Spellman, Regina L.

2004-01-01

A study was performed to examine the influence of varying mesh density on an LS-DYNA simulation of a rectangular-shaped foam projectile impacting the space shuttle leading edge Panel 6. The shuttle leading-edge panels are fabricated of reinforced carbon-carbon (RCC) material. During the study, nine cases were executed with all possible combinations of coarse, baseline, and fine meshes of the foam and panel. For each simulation, the same material properties and impact conditions were specified and only the mesh density was varied. In the baseline model, the shell elements representing the RCC panel are approximately 0.2-in. on edge, whereas the foam elements are about 0.5-in. on edge. The element nominal edge-length for the baseline panel was halved to create a fine panel (0.1-in. edge length) mesh and doubled to create a coarse panel (0.4-in. edge length) mesh. In addition, the element nominal edge-length of the baseline foam projectile was halved (0.25-in. edge length) to create a fine foam mesh and doubled (1.0- in. edge length) to create a coarse foam mesh. The initial impact velocity of the foam was 775 ft/s. The simulations were executed in LS-DYNA version 960 for 6 ms of simulation time. Contour plots of resultant panel displacement and effective stress in the foam were compared at five discrete time intervals. Also, time-history responses of internal and kinetic energy of the panel, kinetic and hourglass energy of the foam, and resultant contact force were plotted to determine the influence of mesh density. As a final comparison, the model with a fine panel and fine foam mesh was executed with slightly different material properties for the RCC. For this model, the average degraded properties of the RCC were replaced with the maximum degraded properties. Similar comparisons of panel and foam responses were made for the average and maximum degraded models.

40 CFR 421.252 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... silver smelted Lead 0.546 0.260 Mercury 0.325 0.130 Silver 0.533 0.221 Zinc 1.898 0.793 Gold 0.130 Oil... monthly average mg/troy ounce of silver reduced in solution Lead 0.168 0.080 Mercury 0.100 0.040 Silver 0... property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold refined electrolytically...

MEASUREMENT OF RADIATION DOSES TO THE EYE LENS DURING ORTHOPEDIC SURGERY USING AN C-ARM X-RAY SYSTEM.

PubMed

Suzuki, Akira; Matsubara, Kosuke; Sasa, Yuko

2018-04-01

The present study aimed to determine doses delivered to the eye lenses of surgeons while using the inverted-C-arm technique and the protective effect of leaded spectacles during orthopedic surgery. The kerma in air was measured at five positions on leaded glasses positioned near the eye lens and on the neck using small optically stimulated luminescence (OSL) dosemeters. The lens equivalent dose was also measured at the neck using an OSL dosemeter. The maximum equivalent dose to the eye lens and the maximum kerma were 0.8 mSv/month and 0.66 mGy/month, respectively. The leaded glasses reduced the exposure by ~60%. Even if the surgeons are exposed to the maximum dose of X-ray radiation for 5 years, the equivalent doses to the eye lens will not exceed the present limit recommended by the ICRP.

The impact of inter-annual variability of annual cycle on long-term persistence of surface air temperature in long historical records

NASA Astrophysics Data System (ADS)

Deng, Qimin; Nian, Da; Fu, Zuntao

2018-02-01

Previous studies in the literature show that the annual cycle of surface air temperature (SAT) is changing in both amplitude and phase, and the SAT departures from the annual cycle are long-term correlated. However, the classical definition of temperature anomalies is based on the assumption that the annual cycle is constant, which contradicts the fact of changing annual cycle. How to quantify the impact of the changing annual cycle on the long-term correlation of temperature anomaly variability still remains open. In this paper, a recently developed data adaptive analysis tool, the nonlinear mode decomposition (NMD), is used to extract and remove time-varying annual cycle to reach the new defined temperature anomalies in which time-dependent amplitude of annual cycle has been considered. By means of detrended fluctuation analysis, the impact induced by inter-annual variability from the time-dependent amplitude of annual cycle has been quantified on the estimation of long-term correlation of long historical temperature anomalies in Europe. The results show that the classical climatology annual cycle is supposed to lack inter-annual fluctuation which will lead to a maximum artificial deviation centering around 600 days. This maximum artificial deviation is crucial to defining the scaling range and estimating the long-term persistence exponent accurately. Selecting different scaling range could lead to an overestimation or underestimation of the long-term persistence exponent. By using NMD method to extract the inter-annual fluctuations of annual cycle, this artificial crossover can be weakened to extend a wider scaling range with fewer uncertainties.

Observations and simulations of the ionospheric lunar tide: Seasonal variability

NASA Astrophysics Data System (ADS)

Pedatella, N. M.

2014-07-01

The seasonal variability of the ionospheric lunar tide is investigated using a combination of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) observations and thermosphere-ionosphere-mesosphere electrodynamics general circulation model (TIME-GCM) simulations. The present study focuses on the seasonal variability of the lunar tide in the ionosphere and its potential connection to the occurrence of stratosphere sudden warmings (SSWs). COSMIC maximum F region electron density (NmF2) and total electron content observations reveal a primarily annual variation of the ionospheric lunar tide, with maximum amplitudes occurring at low latitudes during December-February. Simulations of the lunar tide climatology in TIME-GCM display a similar annual variability as the COSMIC observations. This leads to the conclusion that the annual variability of the lunar tide in the ionosphere is not solely due to the occurrence of SSWs. Rather, the annual variability of the lunar tide in the ionosphere is generated by the seasonal variability of the lunar tide at E region altitudes. However, compared to the observations, the ionospheric lunar tide annual variability is weaker in the climatological simulations which is attributed to the occurrence of SSWs during the majority of the years included in the observations. Introducing a SSW into the TIME-GCM simulation leads to an additional enhancement of the lunar tide during Northern Hemisphere winter, increasing the lunar tide annual variability and resulting in an annual variability that is more consistent with the observations. The occurrence of SSWs can therefore potentially bias lunar tide climatologies, and it is important to consider these effects in studies of the lunar tide in the atmosphere and ionosphere.

WRF simulation of a severe hailstorm over Baramati: a study into the space-time evolution

NASA Astrophysics Data System (ADS)

Murthy, B. S.; Latha, R.; Madhuparna, H.

2018-04-01

Space-time evolution of a severe hailstorm occurred over the western India as revealed by WRF-ARW simulations are presented. We simulated a specific event centered over Baramati (18.15°N, 74.58°E, 537 m AMSL) on March 9, 2014. A physical mechanism, proposed as a conceptual model, signifies the role of multiple convective cells organizing through outflows leading to a cold frontal type flow, in the presence of a low over the northern Arabian Sea, propagates from NW to SE triggering deep convection and precipitation. A `U' shaped cold pool encircled by a converging boundary forms to the north of Baramati due to precipitation behind the moisture convergence line with strong updrafts ( 15 ms-1) leading to convective clouds extending up to 8 km in a narrow region of 30 km. The outflows from the convective clouds merge with the opposing southerly or southwesterly winds from the Arabian Sea and southerly or southeasterly winds from the Bay of Bengal resulting in moisture convergence (maximum 80 × 10-3 g kg-1 s-1). The vertical profile of the area-averaged moisture convergence over the cold pool shows strong convergence above 850 hPa and divergence near the surface indicating elevated convection. Radar reflectivity (50-60 dBZ) and vertical component of vorticity maximum ( 0.01-0.14 s-1) are observed along the convergence zone. Stratiform clouds ahead of the squall line and parallel wind flow at 850 hPa and nearly perpendicular flow at higher levels relative to squall line as evidenced by relatively low and wide-spread reflectivity suggests that organizational mode of squall line may be categorized as `Mixed Mode' type where northern part can be a parallel stratiform while the southern part resembles with a leading stratiform. Simulated rainfall (grid scale 27 km) leads the observed rainfall by 1 h while its magnitude is 2 times of the observed rainfall (grid scale 100 km) derived from Kalpana-1. Thus, this study indicates that under synoptically favorable conditions, WRF-ARW could simulate thunderstorm evolution reasonably well although there is some space-time error which might, perhaps, be the reason for lower CAPE (observed by upper air sounding) on the simulation day.

Bistability, non-ergodicity, and inhibition in pairwise maximum-entropy models

PubMed Central

Grün, Sonja; Helias, Moritz

2017-01-01

Pairwise maximum-entropy models have been used in neuroscience to predict the activity of neuronal populations, given only the time-averaged correlations of the neuron activities. This paper provides evidence that the pairwise model, applied to experimental recordings, would produce a bimodal distribution for the population-averaged activity, and for some population sizes the second mode would peak at high activities, that experimentally would be equivalent to 90% of the neuron population active within time-windows of few milliseconds. Several problems are connected with this bimodality: 1. The presence of the high-activity mode is unrealistic in view of observed neuronal activity and on neurobiological grounds. 2. Boltzmann learning becomes non-ergodic, hence the pairwise maximum-entropy distribution cannot be found: in fact, Boltzmann learning would produce an incorrect distribution; similarly, common variants of mean-field approximations also produce an incorrect distribution. 3. The Glauber dynamics associated with the model is unrealistically bistable and cannot be used to generate realistic surrogate data. This bimodality problem is first demonstrated for an experimental dataset from 159 neurons in the motor cortex of macaque monkey. Evidence is then provided that this problem affects typical neural recordings of population sizes of a couple of hundreds or more neurons. The cause of the bimodality problem is identified as the inability of standard maximum-entropy distributions with a uniform reference measure to model neuronal inhibition. To eliminate this problem a modified maximum-entropy model is presented, which reflects a basic effect of inhibition in the form of a simple but non-uniform reference measure. This model does not lead to unrealistic bimodalities, can be found with Boltzmann learning, and has an associated Glauber dynamics which incorporates a minimal asymmetric inhibition. PMID:28968396

Dynamical resonance shift and unification of resonances in short-pulse laser-cluster interaction

NASA Astrophysics Data System (ADS)

Mahalik, S. S.; Kundu, M.

2018-06-01

Pronounced maximum absorption of laser light irradiating a rare-gas or metal cluster is widely expected during the linear resonance (LR) when Mie-plasma wavelength λM of electrons equals the laser wavelength λ . On the contrary, by performing molecular dynamics (MD) simulations of an argon cluster irradiated by short 5-fs (FWHM) laser pulses it is revealed that, for a given laser pulse energy and a cluster, at each peak intensity there exists a λ —shifted from the expected λM—that corresponds to a unified dynamical LR at which evolution of the cluster happens through very efficient unification of possible resonances in various stages, including (i) the LR in the initial time of plasma creation, (ii) the LR in the Coulomb expanding phase in the later time, and (iii) anharmonic resonance in the marginally overdense regime for a relatively longer pulse duration, leading to maximum laser absorption accompanied by maximum removal of electrons from cluster and also maximum allowed average charge states for the argon cluster. Increasing the laser intensity, the absorption maxima is found to shift to a higher wavelength in the band of λ ≈(1 -1.5 ) λM than permanently staying at the expected λM. A naive rigid sphere model also corroborates the wavelength shift of the absorption peak as found in MD and unequivocally proves that maximum laser absorption in a cluster happens at a shifted λ in the marginally overdense regime of λ ≈(1 -1.5 ) λM instead of λM of LR. The present study is important for guiding an optimal condition laser-cluster interaction experiment in the short-pulse regime.

Bistability, non-ergodicity, and inhibition in pairwise maximum-entropy models.

PubMed

Rostami, Vahid; Porta Mana, PierGianLuca; Grün, Sonja; Helias, Moritz

2017-10-01

Pairwise maximum-entropy models have been used in neuroscience to predict the activity of neuronal populations, given only the time-averaged correlations of the neuron activities. This paper provides evidence that the pairwise model, applied to experimental recordings, would produce a bimodal distribution for the population-averaged activity, and for some population sizes the second mode would peak at high activities, that experimentally would be equivalent to 90% of the neuron population active within time-windows of few milliseconds. Several problems are connected with this bimodality: 1. The presence of the high-activity mode is unrealistic in view of observed neuronal activity and on neurobiological grounds. 2. Boltzmann learning becomes non-ergodic, hence the pairwise maximum-entropy distribution cannot be found: in fact, Boltzmann learning would produce an incorrect distribution; similarly, common variants of mean-field approximations also produce an incorrect distribution. 3. The Glauber dynamics associated with the model is unrealistically bistable and cannot be used to generate realistic surrogate data. This bimodality problem is first demonstrated for an experimental dataset from 159 neurons in the motor cortex of macaque monkey. Evidence is then provided that this problem affects typical neural recordings of population sizes of a couple of hundreds or more neurons. The cause of the bimodality problem is identified as the inability of standard maximum-entropy distributions with a uniform reference measure to model neuronal inhibition. To eliminate this problem a modified maximum-entropy model is presented, which reflects a basic effect of inhibition in the form of a simple but non-uniform reference measure. This model does not lead to unrealistic bimodalities, can be found with Boltzmann learning, and has an associated Glauber dynamics which incorporates a minimal asymmetric inhibition.

Shock wave interaction with laser-generated single bubbles.

PubMed

Sankin, G N; Simmons, W N; Zhu, S L; Zhong, P

2005-07-15

The interaction of a lithotripter shock wave (LSW) with laser-generated single vapor bubbles in water is investigated using high-speed photography and pressure measurement via a fiber-optic probe hydrophone. The interaction leads to nonspherical collapse of the bubble with secondary shock wave emission and microjet formation along the LSW propagation direction. The maximum pressure amplification is produced during the collapse phase of the bubble oscillation when the compressive pulse duration of the LSW matches with the forced collapse time of the bubble.

Advancements in medicine from aerospace research

NASA Technical Reports Server (NTRS)

Wooten, F. T.

1971-01-01

NASA has taken the lead in implementing the concept of technology utilization, and the Technology Utilization Program is the first vital step in the goal of a technological society to insure maximum benefit from the costs of technology. Experience has shown that the active approach to technology transfer is unique and is well received in the medical profession when appropriate problems are tackled. The problem solving approach is a useful one at the precise time when medicine is recognizing the need for new technology.

The Planetary Nebulae Luminosity Function (PNLF): current perspectives

NASA Astrophysics Data System (ADS)

Méndez, Roberto H.

2017-10-01

This paper starts with a brief historical review about the PNLF and its use as a distance indicator. Then the PNLF distances are compared with Surface Brightness Fluctuations (SBF) distances and Tip of the Red Giant Branch (TRGB) distances. A Monte Carlo method to generate simulated PNLFs is described, leading to the last subject: recent progress in reproducing the expected maximum final mass in old stellar populations, a stellar astrophysics enigma that has been challenging us for quite some time.

Closed Form Equations for the Preliminary Design of a Heat-Pipe-Cooled Leading Edge

NASA Technical Reports Server (NTRS)

Glass, David E.

1998-01-01

A set of closed form equations for the preliminary evaluation and design of a heat-pipe-cooled leading edge is presented. The set of equations can provide a leading-edge designer with a quick evaluation of the feasibility of using heat-pipe cooling. The heat pipes can be embedded in a metallic or composite structure. The maximum heat flux, total integrated heat load, and thermal properties of the structure and heat-pipe container are required input. The heat-pipe operating temperature, maximum surface temperature, heat-pipe length, and heat pipe-spacing can be estimated. Results using the design equations compared well with those from a 3-D finite element analysis for both a large and small radius leading edge.

Ultrasonication effects on thermal and rheological properties of carbon nanotube suspensions

PubMed Central

2012-01-01

The preparation of nanofluids is very important to their thermophysical properties. Nanofluids with the same nanoparticles and base fluids can behave differently due to different nanofluid preparation methods. The agglomerate sizes in nanofluids can significantly impact the thermal conductivity and viscosity of nanofluids and lead to a different heat transfer performance. Ultrasonication is a common way to break up agglomerates and promote dispersion of nanoparticles into base fluids. However, research reports of sonication effects on nanofluid properties are limited in the open literature. In this work, sonication effects on thermal conductivity and viscosity of carbon nanotubes (0.5 wt%) in an ethylene glycol-based nanofluid are investigated. The corresponding effects on the agglomerate sizes and the carbon nanotube lengths are observed. It is found that with an increased sonication time/energy, the thermal conductivity of the nanofluids increases nonlinearly, with the maximum enhancement of 23% at sonication time of 1,355 min. However, the viscosity of nanofluids increases to the maximum at sonication time of 40 min, then decreases, finally approaching the viscosity of the pure base fluid at a sonication time of 1,355 min. It is also observed that the sonication process not only reduces the agglomerate sizes but also decreases the length of carbon nanotubes. Over the current experimental range, the reduction in agglomerate size is more significant than the reduction of the carbon nanotube length. Hence, the maximum thermal conductivity enhancement and minimum viscosity increase are obtained using a lengthy sonication, which may have implications on application. PMID:22333487

Interaction between shock wave and single inertial bubbles near an elastic boundary.

PubMed

Sankin, G N; Zhong, P

2006-10-01

The interaction of laser-generated single inertial bubbles (collapse time = 121 mus) near a silicon rubber membrane with a shock wave (55 MPa in peak pressure and 1.7 mus in compressive pulse duration) is investigated. The interaction leads to directional, forced asymmetric collapse of the bubble with microjet formation toward the surface. Maximum jet penetration into the membrane is produced during the bubble collapse phase with optimal shock wave arrival time and stand-off distance. Such interaction may provide a unique acoustic means for in vivo microinjection, applicable to targeted delivery of macromolecules and gene vectors to biological tissues.

Pros and cons of rotating ground motion records to fault-normal/parallel directions for response history analysis of buildings

USGS Publications Warehouse

Kalkan, Erol; Kwong, Neal S.

2014-01-01

According to the regulatory building codes in the United States (e.g., 2010 California Building Code), at least two horizontal ground motion components are required for three-dimensional (3D) response history analysis (RHA) of building structures. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHAs should be performed separately (when FN and then FP are aligned with the transverse direction of the structural axes). It is assumed that this approach will lead to two sets of responses that envelope the range of possible responses over all nonredundant rotation angles. This assumption is examined here, for the first time, using a 3D computer model of a six-story reinforced-concrete instrumented building subjected to an ensemble of bidirectional near-fault ground motions. Peak values of engineering demand parameters (EDPs) were computed for rotation angles ranging from 0 through 180° to quantify the difference between peak values of EDPs over all rotation angles and those due to FN/FP direction rotated motions. It is demonstrated that rotating ground motions to FN/FP directions (1) does not always lead to the maximum responses over all angles, (2) does not always envelope the range of possible responses, and (3) does not provide maximum responses for all EDPs simultaneously even if it provides a maximum response for a specific EDP.

Two-Dimensional Analysis of Conical Pulsed Inductive Plasma Thruster Performance

NASA Technical Reports Server (NTRS)

Hallock, A. K.; Polzin, K. A.; Emsellem, G. D.

2011-01-01

A model of the maximum achievable exhaust velocity of a conical theta pinch pulsed inductive thruster is presented. A semi-empirical formula relating coil inductance to both axial and radial current sheet location is developed and incorporated into a circuit model coupled to a momentum equation to evaluate the effect of coil geometry on the axial directed kinetic energy of the exhaust. Inductance measurements as a function of the axial and radial displacement of simulated current sheets from four coils of different geometries are t to a two-dimensional expression to allow the calculation of the Lorentz force at any relevant averaged current sheet location. This relation for two-dimensional inductance, along with an estimate of the maximum possible change in gas-dynamic pressure as the current sheet accelerates into downstream propellant, enables the expansion of a one-dimensional circuit model to two dimensions. The results of this two-dimensional model indicate that radial current sheet motion acts to rapidly decouple the current sheet from the driving coil, leading to losses in axial kinetic energy 10-50 times larger than estimations of the maximum available energy in the compressed propellant. The decreased available energy in the compressed propellant as compared to that of other inductive plasma propulsion concepts suggests that a recovery in the directed axial kinetic energy of the exhaust is unlikely, and that radial compression of the current sheet leads to a loss in exhaust velocity for the operating conditions considered here.

Enhanced electrocaloric analysis and energy-storage performance of lanthanum modified lead titanate ceramics for potential solid-state refrigeration applications.

PubMed

Zhang, Tian-Fu; Huang, Xian-Xiong; Tang, Xin-Gui; Jiang, Yan-Ping; Liu, Qiu-Xiang; Lu, Biao; Lu, Sheng-Guo

2018-01-10

The unique properties and great variety of relaxer ferroelectrics make them highly attractive in energy-storage and solid-state refrigeration technologies. In this work, lanthanum modified lead titanate ceramics are prepared and studied. The giant electrocaloric effect in lanthanum modified lead titanate ceramics is revealed for the first time. Large refrigeration efficiency (27.4) and high adiabatic temperature change (1.67 K) are achieved by indirect analysis. Direct measurements of electrocaloric effect show that reversible adiabatic temperature change is also about 1.67 K, which exceeds many electrocaloric effect values in current direct measured electrocaloric studies. Both theoretical calculated and direct measured electrocaloric effects are in good agreements in high temperatures. Temperature and electric field related energy storage properties are also analyzed, maximum energy-storage density and energy-storage efficiency are about 0.31 J/cm 3 and 91.2%, respectively.

40 CFR 421.253 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.364 0.169 Mercury 0.195 0.078 Silver 0.377 0.156 Zinc 1.326 0.546 Gold 0.130 (b) Silver... reduced in solution Lead 0.112 0.052 Mercury 0.060 0.024 Silver 0.116 0.048 Zinc 0.408 0.168 Gold 0.040 (c...

40 CFR 421.253 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.364 0.169 Mercury 0.195 0.078 Silver 0.377 0.156 Zinc 1.326 0.546 Gold 0.130 (b) Silver... reduced in solution Lead 0.112 0.052 Mercury 0.060 0.024 Silver 0.116 0.048 Zinc 0.408 0.168 Gold 0.040 (c...

40 CFR 421.253 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.364 0.169 Mercury 0.195 0.078 Silver 0.377 0.156 Zinc 1.326 0.546 Gold 0.130 (b) Silver... reduced in solution Lead 0.112 0.052 Mercury 0.060 0.024 Silver 0.116 0.048 Zinc 0.408 0.168 Gold 0.040 (c...

Investigating Typhoon Induced River-Surge Interactions in the Tamsui Estuary, Taiwan.

NASA Astrophysics Data System (ADS)

Maskell; J. H.; Grieser, J.; Rodney, J.; Howe, N. J.

2016-02-01

It is increasingly important to understand the combined influence of the main drivers of coastal risk due to sea level rise and the potential increase in extreme weather events. An Asian Basin stochastic typhoon set was used to force a storm surge model of Taiwan to investigate the interaction between storm surge and high river discharges (50, 100 and 200 year return period discharges) in the Tamsui River. Taiwan is a mountainous country leading to the combined risk of surge and high river discharge occurring simultaneously in estuary regions. The typhoon tracks were selected using a Hurricane Surge Index (Kantha, 2006) and cross the northern tip of Taiwan with maximum sustained winds (Vmax) between 51 m/s and 75 m/s (Cat 3-5). Peak surge elevations in the Tamsui River range from 5.7 m to 10.3 m. The surge interacts with the river flow to induce changes in the water elevation between -8 m and 4 m depending on the surge elevation and river discharge and increases the inundated area in the range 37 km to 204 km. Significant positive interactions occur in the Tamsui Estuary (Fig. 1a) but do not have implications for increased inundation and occur at the start of the flood phase and the end of the ebb phase as previously shown in idealized test cases (Maskell et al., 2013). Current vectors in the estuary show that at the time leading up to high water the river outflow starts to become dominant in the mid-channel reducing maximum water levels by up to 10% in the combined surge and river solution. However, surge inhibits downstream propagation of the flood wave in the upper river channels increasing water levels by up to 2 m. The maximum inundated area (1330 km2) is caused by the combination of defence overflow due to the maximum surge (10.27 m) and increased river levels (RP100) in the upper channels leading to significant inundation either side of the Keelung River (Fig. 1b). The Erchung floodway is effective in diverting some of the flow (up to 10,443 m3/s) reducing inundation elsewhere in the river network.

Comparison between overweight due to pregnancy and due to added weight to simulate body mass distribution in pregnancy.

PubMed

Aguiar, Liliana; Santos-Rocha, Rita; Vieira, Filomena; Branco, Marco; Andrade, Carlos; Veloso, António

2015-10-01

The assessment of biomechanical loading in the musculoskeletal system of the pregnant women is particularly interesting since they are subject to morphological, physiological and hormonal changes, which may lead to adaptations in gait. The purpose of this study was to analyze the effect of the increased mass in the trunk associated to pregnancy on the lower limb and pelvis, during walking, on temporal-distance parameters, joint range of motion and moments of force, by comparing a pregnant women group to a non-pregnant group, and to this group while carrying a 5 kg additional load located in the abdomen and breasts during walking, to understand which gait adaptations may be more related with the increased trunk mass, or if may be more associated with other factors such as the girth of the thigh. The subjects performed a previous 12 min training adaption to the added load. To calculate ankle, knee and hip joint angles and moments of force, a three-dimensional biomechanical model was developed. The inverse dynamics method was used to estimate net joint moments of force. The increased mass of the anterior trunk associated with second trimester of pregnancy may influence some gait variables such as the left step time, left and right stance times, double limb support time, maximum hip extension, maximum pelvic right obliquity, pelvic obliquity range of motion, maximum transversal left rotation and peak hip flexion moments of force. Copyright © 2015 Elsevier B.V. All rights reserved.

Nano-lead particle synthesis from waste cathode ray-tube funnel glass.

PubMed

Xing, Mingfei; Zhang, Fu-Shen

2011-10-30

Waste cathode ray-tube (CRT) funnel glass is classified as hazardous waste since it contains high amount of lead. In the present study, a novel process for lead nanopowder synthesis from this type of glass was developed by combining vacuum carbon-thermal reduction and inert-gas consolidation procedures. The key trait of the process was to evaporate lead out of the glass to obtain harmless glass powder and synchronously produce lead nanoparticles. In the synthesis process, lead oxide in the funnel glass was firstly reduced to elemental lead, and evaporated rapidly in vacuum circumstance, then quenched and formed nano-size particles on the surface of the cooling device. Experimental results showed that temperature, pressure and argon gas flow rate were the major parameters controlling lead evaporation ratio and the morphology of lead nanoparticles. The maximum lead evaporation ratio was 96.8% and particles of 4-34 nm were successfully obtained by controlling the temperature, holding time, process pressure, argon gas flow rate at 1000°C, 2-4h, 500-2000 Pa, 50-200 ml/min, respectively. Toxicity characteristic leaching procedure (TCLP) results showed that lead leaching from the residue glass met the USEPA threshold. Accordingly, this study developed a practical and environmental-friendly process for detoxification and reclamation of waste lead-containing glass. Copyright © 2011 Elsevier B.V. All rights reserved.

Biological and Abiotic Transformations of Ethylene Dibromide and 1,2-Dichloroethane in Ground Water at Leaded Gasoline Spill Sites

EPA Science Inventory

Tetra-ethyl lead was widely used in leaded automobile gasoline from 1923 until 1987. To prevent lead deposits from fouling the engine, 1,2-dibromoethane (EDB) and 1,2-dichloroethane (1,2-DCA) were added to the gasoline to act as lead scavengers. The Maximum Contaminant Levels...

On the impacts of computing daily temperatures as the average of the daily minimum and maximum temperatures

NASA Astrophysics Data System (ADS)

Villarini, Gabriele; Khouakhi, Abdou; Cunningham, Evan

2017-12-01

Daily temperature values are generally computed as the average of the daily minimum and maximum observations, which can lead to biases in the estimation of daily averaged values. This study examines the impacts of these biases on the calculation of climatology and trends in temperature extremes at 409 sites in North America with at least 25 years of complete hourly records. Our results show that the calculation of daily temperature based on the average of minimum and maximum daily readings leads to an overestimation of the daily values of 10+ % when focusing on extremes and values above (below) high (low) thresholds. Moreover, the effects of the data processing method on trend estimation are generally small, even though the use of the daily minimum and maximum readings reduces the power of trend detection ( 5-10% fewer trends detected in comparison with the reference data).

Nonlinear evolution of Benjamin-Feir wave group based on third order solution of Benjamin-Bona-Mahony equation

NASA Astrophysics Data System (ADS)

Zahnur; Halfiani, Vera; Salmawaty; Tulus; Ramli, Marwan

2018-01-01

This study concerns on the evolution of trichromatic wave group. It has been known that the trichromatic wave group undergoes an instability during its propagation, which results wave deformation and amplification on the waves amplitude. The previous results on the KdV wave group showed that the nonlinear effect will deform the wave and lead to large wave whose amplitude is higher than the initial input. In this study we consider the Benjamin-Bona-Mahony equation and the theory of third order side band approximation to investigate the peaking and splitting phenomena of the wave groups which is initially in trichromatic signal. The wave amplitude amplification and the maximum position will be observed through a quantity called Maximal Temporal Amplitude (MTA) which measures the maximum amplitude of the waves over time.

Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process.

PubMed

Mingfei, Xing; Yaping, Wang; Jun, Li; Hua, Xu

2016-03-15

In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass. Copyright © 2015 Elsevier B.V. All rights reserved.

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

Wei, Yongbin; Jia, Yanmin, E-mail: wuzheng@zjnu.cn, E-mail: ymjia@zjnu.edu.cn; Wu, Jiang

A mutual enhancement action between the ferro-/piezoelectric polarization and the photoluminescent performance of rare earth Pr{sup 3+} doped (K{sub 0.5}Na{sub 0.5})NbO{sub 3} (KNN) lead-free ceramics is reported. After Pr{sup 3+} doping, the KNN ceramics exhibit the maximum enhancement of ∼1.2 times in the ferroelectric remanent polarization strength and ∼1.25 times in the piezoelectric coefficient d{sub 33}, respectively. Furthermore, after undergoing a ferro-/piezoelectric polarization treatment, the maximum enhancement of ∼1.3 times in photoluminescence (PL) was observed in the poled 0.3% Pr{sup 3+} doped sample. After the trivalent Pr{sup 3+} unequivalently substituting the univalent (K{sub 0.5}Na{sub 0.5}){sup +}, A-sites ionic vacancies willmore » occur to maintain charge neutrality, which may reduce the inner stress and ease the domain wall motions, yielding to the enhancement in ferro-/piezoelectric performance. The polarization-induced enhancement in PL is attributed to the decrease of crystal symmetry abound the Pr{sup 3+} ions after polarization. The dual-enhancement of the ferro-/piezoelectric and photoluminescent performance makes the Pr{sup 3+} doped KNN ceramic hopeful for piezoelectric/luminescent multifunctional devices.« less

41 CFR 301-31.10 - How will my agency pay my subsistence expenses?

Code of Federal Regulations, 2011 CFR

2011-07-01

... maximum lodging amount applicable to the locality .75 times the maximum lodging amount applicable to the locality .5 times the maximum lodging amount applicable to the locality. Payment for lodging, meals, and other per diem expenses The maximum per diem rate applicable to the locality .75 times the maximum per...

Preliminary Investigation in the NACA Low-Turbulence Tunnel of Low-drag Airfoil Sections Suitable for Admitting Air at the Leading Edge

NASA Technical Reports Server (NTRS)

von Doenhoff, Albert E.; Horton, Elmer A.

1942-01-01

An investigation was carried out in the NACA low-turbulence tunnel to develop low-drag airfoil sections suitable for admitting air at the leading edge. A thickness distribution having the desired type of pressure distribution was found from tests of a flexible model. Other airfoil shapes were derived from this original shape by varying the thickness, the camper, the leading-edge radius, and the size of the leading-edge opening. Data are presented giving the characteristics of the airfoil shapes in the range of lift coefficients for high-speed and cruising flight. Shapes have been developed which show no substantial increases in drag over that of the same position along the chord. Many of these shapes appear to have higher critical compressibility speeds than plain airfoils of the same thickness. Low-drag airfoil sections have been developed with openings in the leading edge as large as 41.5 percent of the maximum thickness. The range of lift coefficients for low drag in several cases is nearly as large as that of the corresponding plain airfoil sections. Preliminary measurements of maximum lift characteristics indicate that nose-opening sections of the type herein considered may not produce any marked effects on the maximum lift coefficient.

Experimental Verification of the Streamline Curvature Numerical Analysis Method Applied to the Flow through an Axial Flow Fan.

DTIC Science & Technology

1980-05-28

Total Deviation Angles and Measured Inlet Axial Velocity . . . . 55 ix LIST OF FIGURES (Continued) Figure Page 19 Points Defining Blade Sections of...distance from leading edge to point of maximum camber along chord line ar tip vortex core radius AVR axial velocity ratio (Vx /V x c chord length CL tip...yaw ceoefficient d longitudinal distance from leading edge to tip vortex calculation point G distance from chord line to maximum camber point K cascade

The phenology of Arctic Ocean surface warming.

PubMed

Steele, Michael; Dickinson, Suzanne

2016-09-01

In this work, we explore the seasonal relationships (i.e., the phenology) between sea ice retreat, sea surface temperature (SST), and atmospheric heat fluxes in the Pacific Sector of the Arctic Ocean, using satellite and reanalysis data. We find that where ice retreats early in most years, maximum summertime SSTs are usually warmer, relative to areas with later retreat. For any particular year, we find that anomalously early ice retreat generally leads to anomalously warm SSTs. However, this relationship is weak in the Chukchi Sea, where ocean advection plays a large role. It is also weak where retreat in a particular year happens earlier than usual, but still relatively late in the season, primarily because atmospheric heat fluxes are weak at that time. This result helps to explain the very different ocean warming responses found in two recent years with extreme ice retreat, 2007 and 2012. We also find that the timing of ice retreat impacts the date of maximum SST, owing to a change in the ocean surface buoyancy and momentum forcing that occurs in early August that we term the Late Summer Transition (LST). After the LST, enhanced mixing of the upper ocean leads to cooling of the ocean surface even while atmospheric heat fluxes are still weakly downward. Our results indicate that in the near-term, earlier ice retreat is likely to cause enhanced ocean surface warming in much of the Arctic Ocean, although not where ice retreat still occurs late in the season.

Transient, polarity-dependent dielectric response in a twisted nematic liquid crystal under very low frequency excitation.

PubMed

Krishnamurthy, K S

2015-09-01

The electric Freedericksz transition is a second-order quadratic effect, which, in a planarly aligned nematic liquid crystal layer, manifests above a threshold field as a homogeneous symmetric distortion with maximum director-tilt in the midplane. We find that, upon excitation by a low frequency (<0.2Hz) square-wave field, the instability becomes spatially and temporally varying. This is demonstrated using calamitic liquid crystals, initially in the 90°-twisted planar configuration. The distortion occurs close to the negative electrode following each polarity switch and, for low-voltage amplitudes, decays completely in time. We use the elastically favorable geometry of Brochard-Leger walls to establish the location of maximum distortion. Thus, at successive polarity changes, the direction of extension of both annular and open walls switches between the alignment directions at the two substrates. For high voltages, this direction is largely along the midplane director, while remaining marginally oscillatory. These results are broadly understood by taking into account the time-varying and inhomogeneous field conditions that prevail soon after the polarity reverses. Polarity dependence of the instability is traced to the formation of intrinsic double layers that lead to an asymmetry in field distribution in the presence of an external bias. Momentary field elevation near the negative electrode following a voltage sign reversal leads to locally enhanced dielectric and gradient flexoelectric torques, which accounts for the surface-like phenomenon observed at low voltages. These spatiotemporal effects, also found earlier for other instabilities, are generic in nature.

Biosorption of copper and lead ions by waste beer yeast.

PubMed

Han, Runping; Li, Hongkui; Li, Yanhu; Zhang, Jinghua; Xiao, Huijun; Shi, Jie

2006-10-11

Locally available waste beer yeast, a byproduct of brewing industry, was found to be a low cost and promising adsorbent for adsorbing copper and lead ions from wastewater. In this work, biosorption of copper and lead ions on waste beer yeast was investigated in batch mode. The equilibrium adsorptive quantity was determined to be a function of the solution pH, contact time, beer yeast concentration, salt concentration and initial concentration of copper and lead ions. The experimental results were fitted well to the Langmuir and Freundlich model isotherms. According to the parameters of Langmuir isotherm, the maximum biosorption capacities of copper and lead ions onto beer yeast were 0.0228 and 0.0277 mmol g(-1) at 293 K, respectively. The negative values of the standard free energy change (DeltaG degrees ) indicate spontaneous nature of the process. Competitive biosorption of two metal ions was investigated in terms of sorption quantity. The amount of one metal ion adsorbed onto unit weight of biosorbent (q(e)) decreased with increasing the competing metal ion concentration. The binding capacity for lead is more than for copper. Ion exchange is probably one of the main mechanism during adsorptive process.

The most important physiological constants among the Volga region long-livers

NASA Astrophysics Data System (ADS)

Malinova, L. I.; Shuvalov, S. S.; Denisova, T. P.

2012-03-01

In our research we brought out the age difference in the group of long-livers and the continuous character of the biochemical basal metabolism indexes changing. The results allowed us to carry out the polynominal high-powered approximation to study the dynamics of laboratory indexes. We revealed the progressive reduction of the cholesterol, triglycerides, glucose and creatinine levels starting from 90 years of age, and this reduction showed the non-linear character with interchange of local minimums and maximums. During the speed characteristics analysis we revealed the cooccurrence of the speed maximums of all the examined biochemical indexes, except the speed of changing the concentration of cholesterol, which maximum took the lead over the other indexes by four years. The phase-plane portrait analysis of the regulatory systems on the plane "time - speed" showed the unfulfilled attempt of system stabilization by all the searched parameters nearby the special spot - "stable focus". The standard deviation values analysis of the researched parameters showed their progressive reduction in the long-livers. That fact can be considered as the regulatory systems physiological "backlash" reduction among the centenarians.

Efficient heuristics for maximum common substructure search.

PubMed

Englert, Péter; Kovács, Péter

2015-05-26

Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results.

Wind-tunnel and Flight Investigations of the Use of Leading-Edge Area Suction for the Purpose of Increasing the Maximum Lift Coefficient of a 35 Degree Swept-Wing Airplane

NASA Technical Reports Server (NTRS)

Holzhauser, Curt A; Bray, Richard S

1956-01-01

An investigation was undertaken to determine the increase in maximum lift coefficient that could be obtained by applying area suction near the leading edge of a wing. This investigation was performed first with a 35 degree swept-wing model in the wind tunnel, and then with an operational 35 degree swept-wing airplane which was modified in accord with the wind-tunnel results. The wind-tunnel and flight tests indicated that the maximum lift coefficient was increased more than 50 percent by the use of area suction. Good agreement was obtained in the comparison of the wind-tunnel results with those measured in flight.

Potential benefits of triethylamine as n-electron donor in the estimation of forskolin by electronic absorption and emission spectroscopy.

PubMed

Raju, Gajula; Ram Reddy, A

2016-02-05

Diterpenoid forskolin was isolated from Coleus forskolii. The electronic absorption and emission studies of forskolin were investigated in various solvents with an aim to improve its detection limits. The two chromophores present in the diterpenoid are not conjugated leading to the poor absorption and emission of UV light. The absorption and fluorescence spectra were solvent specific. In the presence of a monodentate ligand, triethylamine the detection of forskolin is improved by 3.63 times in ethanol with the fluorescence method and 3.36 times in DMSO by the absorption spectral method. The longer wavelength absorption maximum is blue shifted while the lower energy fluorescence maximum is red shifted in the presence of triethylamine. From the wavelength of fluorescence maxima of the exciplex formed between excited forskolin and triethylamine it is concluded that the order of reactivity of hydroxyl groups in the excited state forskolin is in the reverse order to that of the order of the reactivity of hydroxyl groups in its ground state. Copyright © 2015. Published by Elsevier B.V.

Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses

NASA Astrophysics Data System (ADS)

Mondal, S.; Wei, Q.; Ding, W. J.; Hafez, H. A.; Fareed, M. A.; Laramée, A.; Ropagnol, X.; Zhang, G.; Sun, S.; Sheng, Z. M.; Zhang, J.; Ozaki, T.

2017-01-01

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with a length of 5 μm, a maximum 13.8 times enhancement in the THz pulse energy (in ≤20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies (≤20 THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20-200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets with a length of 60 μm. Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results.

Rapid Adsorption of Copper(II) and Lead(II) by Rice Straw/Fe3O4 Nanocomposite: Optimization, Equilibrium Isotherms, and Adsorption Kinetics Study

PubMed Central

Khandanlou, Roshanak; Ahmad, Mansor B.; Fard Masoumi, Hamid Reza; Shameli, Kamyar; Basri, Mahiran; Kalantari, Katayoon

2015-01-01

Rice straw/magnetic nanocomposites (RS/Fe3O4-NCs) were prepared via co-precipitation method for removal of Pb(II) and Cu(II) from aqueous solutions. Response surface methodology (RSM) was utilized to find the optimum conditions for removal of ions. The effects of three independent variables including initial ion concentration, removal time, and adsorbent dosage were investigated on the maximum adsorption of Pb (II) and Cu (II). The optimum conditions for the adsorption of Pb(II) and Cu(II) were obtained (100 and 60 mg/L) of initial ion concentration, (41.96 and 59.35 s) of removal time and 0.13 g of adsorbent for both ions, respectively. The maximum removal efficiencies of Pb(II) and Cu(II) were obtained 96.25% and 75.54%, respectively. In the equilibrium isotherm study, the adsorption data fitted well with the Langmuir isotherm model. The adsorption kinetics was best depicted by the pseudo-second order model. Desorption experiments showed adsorbent can be reused successfully for three adsorption-desorption cycles. PMID:25815470

[Effect of UV Light Radiation on the Coagulation of Chlorella and Its Mechanism].

PubMed

Wang, Wen-dong; Zhang, Ke; Xu, Hong-bin; Liu, Guo-qi

2016-01-15

Considering algae were difficult to be effectively removed in conventional water treatment process, UV radiation was used to enhance the coagulation of algae in this study. The results showed that with the increase of radiation time, the removal rates of both algae and turbidity experienced a decrease after an increase, and reached their maximum values at 50 min. When the dosage of PAC was 5 mg x L(-1), the removal rates of algae and turbidity of the radiated sample were 20.1% and 18% higher than the blank sample, respectively. When pH ranged from 6 to 9, the coagulation efficiency varied little. At pH 8 and with a radiation time of 50 min, the removal rates of algae and turbidity reached 93.5% and 90.6%, respectively. Meanwhile, the Zeta potential reached the maximum, and the algae generated extracellular organic matter, which favored the subsequent coagulation. After radiated for 60 min, the algal cells was destroyed, leading to a release of intracellular organic matter into the solution. Accordingly, the Zeta potential decreased, which had a negative effect on the subsequent coagulation process.

On the morphology of outbursts of accreting millisecond X-ray pulsar Aquila X-1

NASA Astrophysics Data System (ADS)

Güngör, C.; Ekşi, K. Y.; Göğüş, E.

2017-10-01

We present the X-ray light curves of the last two outbursts - 2014 & 2016 - of the well known accreting millisecond X-ray pulsar (AMXP) Aquila X-1 using the monitor of all sky X-ray image (MAXI) observations in the 2-20 keV band. After calibrating the MAXI count rates to the all-sky monitor (ASM) level, we report that the 2016 outburst is the most energetic event of Aql X-1, ever observed from this source. We show that 2016 outburst is a member of the long-high class according to the classification presented by Güngör et al. with ˜ 68 cnt/s maximum flux and ˜ 60 days duration time and the previous outburst, 2014, belongs to the short-low class with ˜ 25 cnt/s maximum flux and ˜ 30 days duration time. In order to understand differences between outbursts, we investigate the possible dependence of the peak intensity to the quiescent duration leading to the outburst and find that the outbursts following longer quiescent episodes tend to reach higher peak energetic.

Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses.

PubMed

Mondal, S; Wei, Q; Ding, W J; Hafez, H A; Fareed, M A; Laramée, A; Ropagnol, X; Zhang, G; Sun, S; Sheng, Z M; Zhang, J; Ozaki, T

2017-01-10

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with a length of 5 μm, a maximum 13.8 times enhancement in the THz pulse energy (in ≤20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies (≤20 THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20-200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets with a length of 60 μm. Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results.

Aligned copper nanorod arrays for highly efficient generation of intense ultra-broadband THz pulses

PubMed Central

Mondal, S.; Wei, Q.; Ding, W. J.; Hafez, H. A.; Fareed, M. A.; Laramée, A.; Ropagnol, X.; Zhang, G.; Sun, S.; Sheng, Z. M.; Zhang, J.; Ozaki, T.

2017-01-01

We demonstrate an intense broadband terahertz (THz) source based on the interaction of relativistic-intensity femtosecond lasers with aligned copper nanorod array targets. For copper nanorod targets with a length of 5 μm, a maximum 13.8 times enhancement in the THz pulse energy (in ≤20 THz spectral range) is measured as compared to that with a thick plane copper target under the same laser conditions. A further increase in the nanorod length leads to a decrease in the THz pulse energy at medium frequencies (≤20 THz) and increase of the electromagnetic pulse energy in the high-frequency range (from 20–200 THz). For the latter, we measure a maximum energy enhancement of 28 times for the nanorod targets with a length of 60 μm. Particle-in-cell simulations reveal that THz pulses are mostly generated by coherent transition radiation of laser produced hot electrons, which are efficiently enhanced with the use of nanorod targets. Good agreement is found between the simulation and experimental results. PMID:28071764

Maximum Range of a Projectile Thrown from Constant-Speed Circular Motion

ERIC Educational Resources Information Center

Poljak, Nikola

2016-01-01

The problem of determining the angle ? at which a point mass launched from ground level with a given speed v[subscript 0] will reach a maximum distance is a standard exercise in mechanics. There are many possible ways of solving this problem, leading to the well-known answer of ? = p/4, producing a maximum range of D[subscript max] = v[superscript…

Maximum Likelihood Time-of-Arrival Estimation of Optical Pulses via Photon-Counting Photodetectors

NASA Technical Reports Server (NTRS)

Erkmen, Baris I.; Moision, Bruce E.

2010-01-01

Many optical imaging, ranging, and communications systems rely on the estimation of the arrival time of an optical pulse. Recently, such systems have been increasingly employing photon-counting photodetector technology, which changes the statistics of the observed photocurrent. This requires time-of-arrival estimators to be developed and their performances characterized. The statistics of the output of an ideal photodetector, which are well modeled as a Poisson point process, were considered. An analytical model was developed for the mean-square error of the maximum likelihood (ML) estimator, demonstrating two phenomena that cause deviations from the minimum achievable error at low signal power. An approximation was derived to the threshold at which the ML estimator essentially fails to provide better than a random guess of the pulse arrival time. Comparing the analytic model performance predictions to those obtained via simulations, it was verified that the model accurately predicts the ML performance over all regimes considered. There is little prior art that attempts to understand the fundamental limitations to time-of-arrival estimation from Poisson statistics. This work establishes both a simple mathematical description of the error behavior, and the associated physical processes that yield this behavior. Previous work on mean-square error characterization for ML estimators has predominantly focused on additive Gaussian noise. This work demonstrates that the discrete nature of the Poisson noise process leads to a distinctly different error behavior.

Phytotoxicity Study on Bidens sulphurea Sch. Bip. as a Preliminary Approach for Weed Control.

PubMed

da Silva, Bruna P; Nepomuceno, Mariluce P; Varela, Rosa M; Torres, Ascensión; Molinillo, José M G; Alves, Pedro L C A; Macías, Francisco A

2017-06-28

Farmers of the Franca region in Brazil observed that Bidens sulphurea was able to eliminate the Panicum maximum weed, which infected coffee plantations, without affecting the crop. In an effort to determine if the inhibitory effects observed were due to the presence of phytotoxic compounds from leaves and roots, a biodirected isolation and spectroscopic characterization has been carried out. The leaf dichloromethane and root acetone extracts were the most active, and the former appeared to be more phytotoxic to the target species, including four weeds. A total of 26 compounds were isolated from leaves and roots, and four of them are described here for the first time. The major compounds in the leaf extract are the sesquiterpene lactones costunolide, reynosin, and santamarine, and these showed marked inhibition. Amaranthus viridis and Panicum maximum were the most sensitive species of the weeds tested. These three phytotoxic lactones were also evaluated on A. viridis and P. maximum under hydroponic conditions. A. viridis was the most affected species with the three lactones, and santamarine was the most phytotoxic compound on both. This is the first time that the phytotoxicity of sesquiterpene lactones has been evaluated on hydroponic culture. The work described here is a preliminary approach for the use of B. sulphurea for weed control in agriculture, both as a cover crop and by use of its components as natural herbicide leads.

Improved thermoelectric power output from multilayered polyethylenimine doped carbon nanotube based organic composites

NASA Astrophysics Data System (ADS)

Hewitt, Corey A.; Montgomery, David S.; Barbalace, Ryan L.; Carlson, Rowland D.; Carroll, David L.

2014-05-01

By appropriately selecting the carbon nanotube type and n-type dopant for the conduction layers in a multilayered carbon nanotube composite, the total device thermoelectric power output can be increased significantly. The particular materials chosen in this study were raw single walled carbon nanotubes for the p-type layers and polyethylenimine doped single walled carbon nanotubes for the n-type layers. The combination of these two conduction layers leads to a single thermocouple Seebeck coefficient of 96 ± 4 μVK-1, which is 6.3 times higher than that previously reported. This improved Seebeck coefficient leads to a total power output of 14.7 nW per thermocouple at the maximum temperature difference of 50 K, which is 44 times the power output per thermocouple for the previously reported results. Ultimately, these thermoelectric power output improvements help to increase the potential use of these lightweight, flexible, and durable organic multilayered carbon nanotube based thermoelectric modules in low powered electronics applications, where waste heat is available.

Charge Transport between Coupling Colloidal Perovskite Quantum Dots Assisted by Functional Conjugated Ligands.

PubMed

Dai, Jinfei; Xi, Jun; Li, Lu; Zhao, JingFeng; Shi, Yifei; Zhang, Wenwen; Ran, Chenxin; Jiao, Bo; Hou, Xun; Duan, Xinhua; Wu, Zhaoxin

2018-05-14

Long alkyl-chain capping ligands are indispensable for preparing stable colloidal quantum dots. However, its insulating feature blocks efficient carrier transport among QDs, leading to inferior performance in light-emitting diodes (LEDs). The trade-off between conductivity and colloidal stability of QDs has now been overcome. Methylamine lead bromide (MAPbBr 3 ) QDs with a conjugated alkyl-amine, 3-phenyl-2-propen-1-amine (PPA), as ligands were prepared. Owing to electron cloud overlapping and the delocalization effect of conjugated molecules, the conductivity and carrier mobility of PPA-QDs films increased almost 22 times over that of OA-QD films without compromising colloidal stability and photoluminescence. PPA-QDs LEDs exhibit a maximum current efficiency of 9.08 cd A -1 , which is 8 times of that of OA-QDs LEDs (1.14 cd A -1 ). This work provides critical solution for the poor conductivity of QDs in applications of energy-related devices. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Retrospective evaluation of lead contamination in honey from 2005 to present in northeastern Italy and future perspectives in the light of updated legislation.

PubMed

Martinello, Marianna; Dainese, Nicoletta; Manzinello, Chiara; Borin, Alice; Gallina, Albino; Mutinelli, Franco

2016-09-01

Lead is a naturally occurring element but largely originating from human activities. Food is the major source of exposure to lead for humans and the publication of a scientific opinion from the European Food Safety Authority on the risks to human health related to the presence of lead in foodstuffs, led European Union to establish more restrictive limits for this contaminant in food from 1 January 2016. In particular, a maximum level of 0.10 mg kg(-1) was established for honey. The retrospective evaluation of 995 honey samples analysed since 2005, revealed a progressive reduction in the concentration of lead, with a mean value of 0.045 mg kg(-1) in 2015. Total 1.5% of honeys analysed in 2015 exceeded the maximum lead level and therefore will no longer be marketable. Interested beekeepers should clarify the causes of honey contamination and adopt corrective actions to keep their honey production within the legal levels of lead.

Lipstick and Lead: Questions and Answers

MedlinePlus

... cosmetics, such as eye shadows, blushes, compact powders, shampoos, and body lotions. Our guidance recommends a maximum ... less than 10 ppm lead. Based on our surveys we determined that manufacturers are capable of limiting ...

Estimation of temperature in micromaser-type systems

NASA Astrophysics Data System (ADS)

Farajollahi, B.; Jafarzadeh, M.; Rangani Jahromi, H.; Amniat-Talab, M.

2018-06-01

We address the estimation of the number of photons and temperature in a micromaser-type system with Fock state and thermal fields. We analyze the behavior of the quantum Fisher information (QFI) for both fields. In particular, we show that in the Fock state field model, the QFI for non-entangled initial state of the atoms increases monotonously with time, while for entangled initial state of the atoms, it shows oscillatory behavior, leading to non-Markovian dynamics. Moreover, it is observed that the QFI, entropy of entanglement and fidelity have collapse and revival behavior. Focusing on each period that the collapses and revivals occur, we see that the optimal points of the QFI and entanglement coincide. In addition, when one of the subsystems evolved state fidelity becomes maximum, the QFI also achieves its maximum. We also address the evolved fidelity versus the initial state as a good witness of non-Markovianity. Moreover, we interestingly find that the entropy of the composite system can be used as a witness of non-Markovian evolution of the subsystems. For the thermal field model, we similarly investigate the relation among the QFI associated with the temperature, von Neumann entropy, and fidelity. In particular, it is found that at the instants when the maximum values of the QFI are achieved, the entanglement between the two-qubit system and the environment is maximized while the entanglement between the probe and its environment is minimized. Moreover, we show that the thermometry may lead to optimal estimation of practical temperatures. Besides, extending our computation to the two-qubit system, we find that using a two-qubit probe generally leads to more effective estimation than the one-qubit scenario. Finally, we show that initial state entanglement plays a key role in the advent of non-Markovianity and determination of its strength in the composite system and its subsystems.

Meteorological transport of continental soot to Antarctica?

NASA Astrophysics Data System (ADS)

Murphey, B. B.; Hogan, A. W.

1992-01-01

An impactor/concentrator/microdensitometer (ICM) instrument system has been constructed and calibrated. This system is sufficiently sensitive to measure the black (carbon soot) component of Antarctic aerosol with a sampling time of four hours. The impactor concentrator was exposed to Antarctic air at Ross Island in September 1987. Microdensitometer analysis of the collected specimens indicates that the maximum black aerosol concentration was observed concurrently with the arrival of the warmest air accompanying a cyclonic storm. This is similar to the concurrence of continental radon and lead isotopes with warm advection, measured on the Antarctic coast by Polian et al. (1986). It is possible that continental soot can be transported to the Antarctic coast several times each year by this mechanism.

A review of passive thermal management of LED module

NASA Astrophysics Data System (ADS)

Huaiyu, Ye; Koh, Sau; van Zeijl, Henk; Gielen, A. W. J.; Guoqi, Zhang

2011-01-01

Recently, the high-brightness LEDs have begun to be designed for illumination application. The increased electrical currents used to drive LEDs lead to thermal issues. Thermal management for LED module is a key design parameter as high operation temperature directly affects their maximum light output, quality, reliability and life time. In this review, only passive thermal solutions used on LED module will be studied. Moreover, new thermal interface materials and passive thermal solutions applied on electronic equipments are discussed which have high potential to enhance the thermal performance of LED Module.

Paramagnetic iron-doped hydroxyapatite nanoparticles with improved metal sorption properties. A bioorganic substrates-mediated synthesis.

PubMed

Mercado, D Fabio; Magnacca, Giuliana; Malandrino, Mery; Rubert, Aldo; Montoneri, Enzo; Celi, Luisella; Bianco Prevot, Alessandra; Gonzalez, Mónica C

2014-03-26

This paper describes the synthesis of paramegnetic iron-containing hydroxyapatite nanoparticles and their increased Cu(2+) sorbent capacity when using Ca(2+) complexes of soluble bioorganic substrates from urban wastes as synthesis precursors. A thorough characterization of the particles by TEM, XRD, FTIR spectroscopy, specific surface area, TGA, XPS, and DLS indicates that loss of crystallinity, a higher specific area, an increased surface oxygen content, and formation of surface iron phases strongly enhance Cu(2+) adsorption capacity of hydroxyapatite-based materials. However, the major effect of the surface and morphologycal modifications is the size diminution of the aggregates formed in aqueous solutions leading to an increased effective surface available for Cu(2+) adsorption. Maximum sorption values of 550-850 mg Cu(2+) per gram of particles suspended in an aqueous solution at pH 7 were determined, almost 10 times the maximum values observed for hydroxyapatite nanoparticles suspensions under the same conditions.

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

Toxic metals in imported fruits and vegetables marketed in Kuwait

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

Husain, A.; Baroon, Z.; Al-Khalafawi, M.

1995-12-31

The concentration of lead, cadmium, and mercury in 134 samples of imported fruits and vegetables marketed in Kuwait were determined using an atomic absorption spectrophotometer with a graphite furnace and the cold vapor technique. Results obtained showed that the concentration of these metal ions in most cases did not exceed the maximum permissible concentration of metals in fresh fruits and vegetables as restricted by some countries. Only a few samples of fruits and vegetables contained levels of mercury, cadmium, and lead which exceeded these maximum permissible levels.

A MODEL FOR THERMAL PHASE VARIATIONS OF CIRCULAR AND ECCENTRIC EXOPLANETS

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

Cowan, Nicolas B.; Agol, Eric, E-mail: n-cowan@northwestern.edu

2011-01-10

We present a semi-analytic model atmosphere for close-in exoplanets that captures the essential physics of phase curves: orbital and viewing geometry, advection, and re-radiation. We calibrate the model with the well-characterized transiting planet, HD 189733b, then compute light curves for seven of the most eccentric transiting planets: Gl 436b, HAT-P-2b, HAT-P-11b, HD 17156b, HD 80606b, WASP-17b, and XO-3b. We present phase variations for a variety of different radiative times and wind speeds. In the limit of instant re-radiation, the light-curve morphology is entirely dictated by the planet's eccentricity and argument of pericenter: the light curve maximum leads or trails themore » eclipse depending on whether the planet is receding from or approaching the star at superior conjunction, respectively. For a planet with non-zero radiative timescales, the phase peak occurs early for super-rotating winds, and late for sub-rotating winds. We find that for a circular orbit, the timing of the phase variation maximum with respect to superior conjunction indicates the direction of the dominant winds, but cannot break the degeneracy between wind speed and radiative time. For circular planets the phase minimum occurs half an orbit away from the phase maximum-despite the fact that the coolest longitudes are always near the dawn terminator-and therefore does not convey any additional information. In general, increasing the advective frequency or the radiative time has the effect of reducing the peak-to-trough amplitude of phase variations, but there are interesting exceptions to these trends. Lastly, eccentric planets with orbital periods significantly longer than their radiative time exhibit 'ringing', whereby the hot spot generated at periastron rotates in and out of view. The existence of ringing makes it possible to directly measure the wind speed (the frequency of the ringing) and the radiative time constant (the damping of the ringing).« less

The Application of Extended Cox Proportional Hazard Method for Estimating Survival Time of Breast Cancer

NASA Astrophysics Data System (ADS)

Husain, Hartina; Astuti Thamrin, Sri; Tahir, Sulaiha; Mukhlisin, Ahmad; Mirna Apriani, M.

2018-03-01

Breast cancer is one type of cancer that is the leading cause of death worldwide. This study aims to model the factors that affect the survival time and rate of cure of breast cancer patients. The extended cox model, which is a modification of the proportional hazard cox model in which the proportional hazard assumptions are not met, is used in this study. The maximum likelihood estimation approach is used to estimate the parameters of the model. This method is then applied to medical record data of breast cancer patient in 2011-2016, which is taken from Hasanuddin University Education Hospital. The results obtained indicate that the factors that affect the survival time of breast cancer patients are malignancy and leukocyte levels.

Transitions between refrigeration regions in extremely short quantum cycles

NASA Astrophysics Data System (ADS)

Feldmann, Tova; Kosloff, Ronnie

2016-05-01

The relation between the geometry of refrigeration cycles and their performance is explored. The model studied is based on a coupled spin system. Small cycle times, termed sudden refrigerators, develop coherence and inner friction. We explore the interplay between coherence and energy of the working medium employing a family of sudden cycles with decreasing cycle times. At the point of maximum coherence the cycle changes geometry. This region of cycle times is characterized by a dissipative resonance where heat is dissipated both to the hot and cold baths. We rationalize the change of geometry of the cycle as a result of a half-integer quantization which maximizes coherence. From this point on, increasing or decreasing the cycle time, eventually leads to refrigeration cycles. The transition point between refrigerators and short circuit cycles is characterized by a transition from finite to singular dynamical temperature. Extremely short cycle times reach a universal limit where all cycles types are equivalent.

40 CFR 461.35 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory § 461.35...—pounds per 1,000,000 pounds of lead used Copper 0.026 0.012 Lead 0.005 0.002 (4) Subpart C—Battery Wash... Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English units—pounds per 1,000...

40 CFR 461.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory... lead used Copper 0.039 0.021 Lead 0.008 0.004 Iron 0.030 0.010 (4) Subpart C—Battery Wash (Detergent... Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English units—pounds per 1,000...

40 CFR 461.35 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...) EFFLUENT GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory § 461.35...—pounds per 1,000,000 pounds of lead used Copper 0.026 0.012 Lead 0.005 0.002 (4) Subpart C—Battery Wash... Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English units—pounds per 1,000...

40 CFR 461.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory... lead used Copper 0.039 0.021 Lead 0.008 0.004 Iron 0.030 0.010 (4) Subpart C—Battery Wash (Detergent... Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English units—pounds per 1,000...

40 CFR 461.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

...) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) BATTERY MANUFACTURING POINT SOURCE CATEGORY Lead Subcategory... lead used Copper 0.039 0.021 Lead 0.008 0.004 Iron 0.030 0.010 (4) Subpart C—Battery Wash (Detergent... Maximum for monthly average Metric units—mg/kg of lead in trucked batteries English units—pounds per 1,000...

Assessment of voice, speech and communication changes associated with cervical spinal cord injury.

PubMed

Johansson, Kerstin; Seiger, Åke; Forsén, Malin; Holmgren Nilsson, Jeanette; Hartelius, Lena; Schalling, Ellika

2018-02-24

Respiratory muscle impairment following cervical spinal cord injury (CSCI) may lead to reduced voice function, although the individual variation is large. Voice problems in this population may not always receive attention since individuals with CSCI face other, more acute and life-threatening issues that need/receive attention. Currently there is no consensus on the tasks suitable to identify the specific voice impairments and functional voice changes experienced by individuals with CSCI. To examine which voice/speech tasks identify the specific voice and communication changes associated with CSCI, habitual and maximum speech performance of a group with CSCI was compared with that of a healthy control group (CG), and the findings were related to respiratory function and to self-reported voice problems. Respiratory, aerodynamic, acoustic and self-reported voice data from 19 individuals (nine women and 10 men, aged 23-59 years, heights = 153-192 cm) with CSCI (levels C3-C7) were compared with data from a CG consisting of 19 carefully matched non-injured people (nine women and 10 men, aged 19-59 years, heights = 152-187 cm). Despite considerable variability of performance, highly significant differences between the group with CSCI and the CG were found in maximum phonation time, maximum duration of breath phrases, maximum sound pressure level and maximum voice area in voice-range profiles (all p = .000). Subglottal pressure was lower and phonatory stability was reduced in some of the individuals with CSCI, but differences between the groups were not statistically significant. Six of 19 had voice handicap index (VHI) scores above 20 (the cut-off for voice disorder). Individuals with a vital capacity below 50% of the expected for an equivalent reference individual performed significantly worse than participants with more normal vital capacity. Completeness and level of injury seemed to impact vocal function in some individuals. A combination of maximum performance speech tasks, respiratory tasks and self-reported information on voice problems help to identify individuals with reduced voice function following CSCI. Early identification of individuals with voice changes post-CSCI, and introducing appropriate rehabilitation strategies, may help to minimize development of maladaptive voice behaviours such as vocal strain, which can lead to further impairments and limitations to communication participation. © 2018 Royal College of Speech and Language Therapists.

Knee joint moments during high flexion movements: Timing of peak moments and the effect of safety footwear.

PubMed

Chong, Helen C; Tennant, Liana M; Kingston, David C; Acker, Stacey M

2017-03-01

(1) Characterize knee joint moments and peak knee flexion moment timing during kneeling transitions, with the intent of identifying high-risk postures. (2) Determine whether safety footwear worn by kneeling workers (construction workers, tile setters, masons, roofers) alters high flexion kneeling mechanics. Fifteen males performed high flexion kneeling transitions. Kinetics and kinematics were analyzed for differences in ascent and descent in the lead and trail legs. Mean±standard deviation peak external knee adduction and flexion moments during transitions ranged from 1.01±0.31 to 2.04±0.66% body weight times height (BW∗Ht) and from 3.33 to 12.6% BW∗Ht respectively. The lead leg experienced significantly higher adduction moments compared to the trail leg during descent, when work boots were worn (interaction, p=0.005). There was a main effect of leg (higher lead vs. trail) on the internal rotation moment in both descent (p=0.0119) and ascent (p=0.0129) phases. Peak external knee adduction moments during transitions did not exceed those exhibited during level walking, thus increased knee adduction moment magnitude is likely not a main factor in the development of knee OA in occupational kneelers. Additionally, work boots only significantly increased the adduction moment in the lead leg during descent. In cases where one knee is painful, diseased, or injured, the unaffected knee should be used as the lead leg during asymmetric bilateral kneeling. Peak flexion moments occurred at flexion angles above the maximum flexion angle exhibited during walking (approximately 60°), supporting the theory that the loading of atypical surfaces may aid disease development or progression. Copyright © 2016 Elsevier B.V. All rights reserved.

Conditioning of the 4 Curies Radium-226 Sealed Radiation Source in Thailand

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

Punnachaiya, M.; Sawangsri, T.; Wanabongse, P.

This paper describes the conditioning of the 4 curies Radium-226 (Ra-226) sealed radiation source using as a teletherapy unit for cancer treatment in Thailand. The conditioning was under the International Atomic Energy Agency (IAEA) supervision and budgetary supports, comprised of 6 operational steps: the surface dose rate and actual dimension of radium unit measurements, the appropriate lead shielding design with IAEA approval, confirmation of radioactive contamination before conditioning (smear test and radon gas leakage test), transfer of radium source unit into the designed shielding, confirmation of radioactive contamination and dose rate measurement after conditioning, and transportation of Ra-226 conditioning wastemore » package to OAP interim waste storage. The Ra-226 unit was taken out of OAP temporary waste storage for the surface dose rate and the actual dimension measurements behind the 12 inches thick heavy concrete shielding. The maximum measured surface dose rate was 70 R/hr. The special lead container was designed according to its surface dose rate along the source unit which the maximum permissible dose limit for surface dose rate of waste package after conditioning at 2 mSv/hr was applied. The IAEA approved container had total weight of 2.4 ton. After the confirmation of radioactive contamination, Ra-226 source unit was transferred and loaded in the designed lead shielding within 2 minutes. The results of smear test before and after conditioning including radon gas leakage test revealed that there was no radioactive contamination. After conditioning, the surface dose rate measured on the top, bottom were 15,10 mR/hr and varied from 6 - 50 mR/hr around lead container. The Ra-226 conditioning waste package was safely transported to store in OAP interim waste storage. Total working time including the time consumed for radon gas leakage test was 3.5 hours. The total radiation dose received by 16 operators, were ranged from 1 - 69.84 {mu}Sv and the operational team completed the conditioning safely within the effective dose limit for occupational exposure of 50 mSv/year (200 {mu}Sv/day). (authors)« less

Spectrum formation in superluminous supernovae (Type I)

NASA Astrophysics Data System (ADS)

Mazzali, P. A.; Sullivan, M.; Pian, E.; Greiner, J.; Kann, D. A.

2016-06-01

The near-maximum spectra of most superluminous supernovae (SLSNe) that are not dominated by interaction with a H-rich circum-stellar medium (SLSN-I) are characterized by a blue spectral peak and a series of absorption lines which have been identified as O II. SN 2011kl, associated with the ultra-long gamma-ray burst GRB111209A, also had a blue peak but a featureless optical/ultraviolet (UV) spectrum. Radiation transport methods are used to show that the spectra (not including SN 2007bi, which has a redder spectrum at peak, like ordinary SNe Ic) can be explained by a rather steep density distribution of the ejecta, whose composition appears to be typical of carbon-oxygen cores of massive stars which can have low metal content. If the photospheric velocity is ˜10 000-15 000 km s-1, several lines form in the UV. O II lines, however, arise from very highly excited lower levels, which require significant departures from local thermodynamic equilibrium to be populated. These SLSNe are not thought to be powered primarily by 56Ni decay. An appealing scenario is that they are energized by X-rays from the shock driven by a magnetar wind into the SN ejecta. The apparent lack of evolution of line velocity with time that characterizes SLSNe up to about maximum is another argument in favour of the magnetar scenario. The smooth UV continuum of SN 2011kl requires higher ejecta velocities (˜20 000 km s-1): line blanketing leads to an almost featureless spectrum. Helium is observed in some SLSNe after maximum. The high-ionization near-maximum implies that both He and H may be present but not observed at early times. The spectroscopic classification of SLSNe should probably reflect that of SNe Ib/c. Extensive time coverage is required for an accurate classification.

Variation of plantar pressure in Chinese diabetes mellitus.

PubMed

Yang, Chuan; Xiao, Huisheng; Wang, Chuan; Mai, LiFang; Liu, Dan; Qi, Yiqing; Ren, Meng; Yan, Li

2015-01-01

To investigate dynamic changes in plantar pressure in Chinese diabetes mellitus patients and to provide a basis for further preventing diabetic foot. This is a cross-sectional investigation including 649 Chinese diabetes mellitus patients (diabetes group) and 808 "normal" Chinese persons (nondiabetes group) with normal blood glucose levels. All the subjects provided a complete medical history and underwent a physical examination and a 75-g oral glucose tolerance test. All subjects walked barefoot with their usual gait, and their dynamic plantar forces were measured using the one-step method with a plantar pressure measurement instrument; 5 measurements were performed for each foot. No significant differences were found in age, height, body weight, or body mass index between the two groups. The fasting blood glucose levels, plantar contact time, maximum force, pressure-time integrals and force-time integrals in the diabetes group were significantly higher than those in the nondiabetes group (p < 0.05). However, the maximum pressure was significantly higher in the nondiabetes group than in the diabetes group (p < 0.05). No difference was found in the contact areas between the two groups (p > 0.05). The maximum plantar force distributions were essentially the same, with the highest force found for the medial heel, followed by the medial forefoot and the first toe. The peak plantar pressure was located at the medial forefoot for the nondiabetes group and at the hallucis for the diabetes group. In the diabetes group, the momentum in each plantar region was higher than that in the nondiabetes group; this difference was especially apparent in the heel, the lateral forefoot and the hallucis. The dynamic plantar pressures in diabetic patients differ from those in nondiabetic people with increased maximum force and pressure, a different distribution pattern and significantly increased momentum, which may lead to the formation of foot ulcers. © 2015 by the Wound Healing Society.

Glacial ocean circulation and stratification explained by reduced atmospheric temperature

NASA Astrophysics Data System (ADS)

Jansen, Malte F.

2017-01-01

Earth’s climate has undergone dramatic shifts between glacial and interglacial time periods, with high-latitude temperature changes on the order of 5-10 °C. These climatic shifts have been associated with major rearrangements in the deep ocean circulation and stratification, which have likely played an important role in the observed atmospheric carbon dioxide swings by affecting the partitioning of carbon between the atmosphere and the ocean. The mechanisms by which the deep ocean circulation changed, however, are still unclear and represent a major challenge to our understanding of glacial climates. This study shows that various inferred changes in the deep ocean circulation and stratification between glacial and interglacial climates can be interpreted as a direct consequence of atmospheric temperature differences. Colder atmospheric temperatures lead to increased sea ice cover and formation rate around Antarctica. The associated enhanced brine rejection leads to a strongly increased deep ocean stratification, consistent with high abyssal salinities inferred for the last glacial maximum. The increased stratification goes together with a weakening and shoaling of the interhemispheric overturning circulation, again consistent with proxy evidence for the last glacial. The shallower interhemispheric overturning circulation makes room for slowly moving water of Antarctic origin, which explains the observed middepth radiocarbon age maximum and may play an important role in ocean carbon storage.

Glacial ocean circulation and stratification explained by reduced atmospheric temperature

PubMed Central

Jansen, Malte F.

2017-01-01

Earth’s climate has undergone dramatic shifts between glacial and interglacial time periods, with high-latitude temperature changes on the order of 5–10 °C. These climatic shifts have been associated with major rearrangements in the deep ocean circulation and stratification, which have likely played an important role in the observed atmospheric carbon dioxide swings by affecting the partitioning of carbon between the atmosphere and the ocean. The mechanisms by which the deep ocean circulation changed, however, are still unclear and represent a major challenge to our understanding of glacial climates. This study shows that various inferred changes in the deep ocean circulation and stratification between glacial and interglacial climates can be interpreted as a direct consequence of atmospheric temperature differences. Colder atmospheric temperatures lead to increased sea ice cover and formation rate around Antarctica. The associated enhanced brine rejection leads to a strongly increased deep ocean stratification, consistent with high abyssal salinities inferred for the last glacial maximum. The increased stratification goes together with a weakening and shoaling of the interhemispheric overturning circulation, again consistent with proxy evidence for the last glacial. The shallower interhemispheric overturning circulation makes room for slowly moving water of Antarctic origin, which explains the observed middepth radiocarbon age maximum and may play an important role in ocean carbon storage. PMID:27994158

Glacial ocean circulation and stratification explained by reduced atmospheric temperature.

PubMed

Jansen, Malte F

2017-01-03

Earth's climate has undergone dramatic shifts between glacial and interglacial time periods, with high-latitude temperature changes on the order of 5-10 °C. These climatic shifts have been associated with major rearrangements in the deep ocean circulation and stratification, which have likely played an important role in the observed atmospheric carbon dioxide swings by affecting the partitioning of carbon between the atmosphere and the ocean. The mechanisms by which the deep ocean circulation changed, however, are still unclear and represent a major challenge to our understanding of glacial climates. This study shows that various inferred changes in the deep ocean circulation and stratification between glacial and interglacial climates can be interpreted as a direct consequence of atmospheric temperature differences. Colder atmospheric temperatures lead to increased sea ice cover and formation rate around Antarctica. The associated enhanced brine rejection leads to a strongly increased deep ocean stratification, consistent with high abyssal salinities inferred for the last glacial maximum. The increased stratification goes together with a weakening and shoaling of the interhemispheric overturning circulation, again consistent with proxy evidence for the last glacial. The shallower interhemispheric overturning circulation makes room for slowly moving water of Antarctic origin, which explains the observed middepth radiocarbon age maximum and may play an important role in ocean carbon storage.

Dynamic analysis of concentrated solar supercritical CO2-based power generation closed-loop cycle

DOE PAGES

Osorio, Julian D.; Hovsapian, Rob; Ordonez, Juan C.

2016-01-01

Here, the dynamic behavior of a concentrated solar power (CSP) supercritical CO 2 cycle is studied under different seasonal conditions. The system analyzed is composed of a central receiver, hot and cold thermal energy storage units, a heat exchanger, a recuperator, and multi-stage compression-expansion subsystems with intercoolers and reheaters between compressors and turbines respectively. Energy models for each component of the system are developed in order to optimize operating and design parameters such as mass flow rate, intermediate pressures and the effective area of the recuperator to lead to maximum efficiency. Our results show that the parametric optimization leads themore » system to a process efficiency of about 21 % and a maximum power output close to 1.5 MW. The thermal energy storage allows the system to operate for several hours after sunset. This operating time is approximately increased from 220 to 480 minutes after optimization. The hot and cold thermal energy storage also lessens the temperature fluctuations by providing smooth changes of temperatures at the turbines and compressors inlets. Our results indicate that concentrated solar systems using supercritical CO 2 could be a viable alternative to satisfying energy needs in desert areas with scarce water and fossil fuel resources.« less

Contaminated lead environments of man: reviewing the lead isotopic evidence in sediments, peat, and soils for the temporal and spatial patterns of atmospheric lead pollution in Sweden.

PubMed

Bindler, Richard

2011-08-01

Clair Patterson and colleagues demonstrated already four decades ago that the lead cycle was greatly altered on a global scale by humans. Moreover, this change occurred long before the implementation of monitoring programs designed to study lead and other trace metals. Patterson and colleagues also developed stable lead isotope analyses as a tool to differentiate between natural and pollution-derived lead. Since then, stable isotope analyses of sediment, peat, herbaria collections, soils, and forest plants have given us new insights into lead biogeochemical cycling in space and time. Three important conclusions from our studies of lead in the Swedish environment conducted over the past 15 years, which are well supported by extensive results from elsewhere in Europe and in North America, are: (1) lead deposition rates at sites removed from major point sources during the twentieth century were about 1,000 times higher than natural background deposition rates a few thousand years ago (~10 mg Pb m(-2) year(-1) vs. 0.01 mg Pb m(-2) year(-1)), and even today (~1 mg Pb m(-2) year(-1)) are still almost 100 times greater than natural rates. This increase from natural background to maximum fluxes is similar to estimated changes in body burdens of lead from ancient times to the twentieth century. (2) Stable lead isotopes ((206)Pb/(207)Pb ratios shown in this paper) are an effective tool to distinguish anthropogenic lead from the natural lead present in sediments, peat, and soils for both the majority of sites receiving diffuse inputs from long range and regional sources and for sites in close proximity to point sources. In sediments >3,500 years and in the parent soil material of the C-horizon, (206)Pb/(207)Pb ratios are higher, 1.3 to >2.0, whereas pollution sources and surface soils and peat have lower ratios that have been in the range 1.14-1.18. (3) Using stable lead isotopes, we have estimated that in southern Sweden the cumulative anthropogenic burden of atmospherically deposited lead is ~2-5 g Pb m(-2) and ~1 g Pb m(-2) in the "pristine" north. Half of this cumulative total was deposited before industrialization. (4) In the vicinity of the Rönnskär smelter in northern Sweden, a major point source during the twentieth century, there is an isotopic pattern that deviates from the general trends elsewhere, reflecting the particular history of ore usage at Rönnskär, which further demonstrates the chronological record of lead loading recorded in peat and in soil mor horizons.

Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers.

PubMed

Olmedo, P; Pla, A; Hernández, A F; Barbier, F; Ayouni, L; Gil, F

2013-09-01

Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead). Copyright © 2013 Elsevier Ltd. All rights reserved.

Biosorption of lead, copper and cadmium using the extracellular polysaccharides (EPS) of Bacillus sp., from solar salterns.

PubMed

Shameer, Syed

2016-12-01

Extracellular Polysaccharides (EPS) from both prokaryotes and eukaryotes have a great deal of research interest as they protect the producer from different stresses including antibiotics, ionic stress, desiccation and assist in bio-film formation, pathogenesis, adhesion, etc. In this study haloalkaliphilic Bacillus sp., known to cope with osmophilic stress, was selected and screened for EPS production. The EPS were isolated, partially purified and chemical characteristics were documented using liquid FT-IR followed by assessment of heavy metal biosorption (lead, copper and cadmium) using Atomic Absorption Spectroscopy (AAS). The EPS extracted from three isolates B. licheniformis NSPA5, B. cereus NSPA8 and B. subtilis NSPA13 showed maximum biosorption of Lead followed by Copper and Cadmium. Of the tested isolates, the EPS from isolate B. cereus NSPA8 showed maximum (90 %) biosorption of the lead.

Removal of lead from aqueous solutions using Cassia grandis seed gum-graft-poly(methylmethacrylate).

PubMed

Singh, Vandana; Tiwari, Stuti; Sharma, Ajit Kumar; Sanghi, Rashmi

2007-12-15

Using persulfate/ascorbic acid redox system, a series of Cassia grandis seed gum-graft-poly(methylmethacrylate) samples were synthesized. The copolymer samples were evaluated for lead(II) removal from the aqueous solutions where the sorption capacities were found proportional to the grafting extent. The conditions for the sorption were optimized using copolymer sample of highest percent grafting. The sorption was found pH and concentration dependent, pH 2.0 being the optimum value. Adsorption of lead by the grafted seed gum followed a pseudo-second-order kinetics with a rate constant of 4.64 x 10(-5) g/mg/min. The equilibrium data followed the Langmuir isotherm model with maximum sorption capacity of 126.58 mg/g. The influence of electrolytes NaCl, Na(2)SO(4) on lead uptake was also studied. Desorption with 2 N HCl could elute 76% of the lead ions from the lead-loaded copolymer. The regeneration experiments revealed that the copolymer could be successfully reused for at least four cycles though there was a successive loss in lead sorption capacity with every cycle. The adsorbent was also evaluated for Pb(II) removal from battery waste-water containing 2166 mg/L Pb(II). From 1000 times diluted waste water, 86.1% Pb(II) could be removed using 0.05 g/20 ml adsorbent dose, while 0.5 g/20 ml adsorbent dose was capable of removing 60.29% Pb from 10 times diluted waste water. Optimum Pb(II) binding under highly acidic conditions indicated that there was a significant contribution of nonelectrostatic interactions in the adsorption process. A possible mechanism for the adsorption has been discussed.

41 CFR 301-31.10 - How will my agency pay my subsistence expenses?

Code of Federal Regulations, 2010 CFR

2010-07-01

... applicable to the locality .75 times the maximum lodging amount applicable to the locality .5 times the maximum lodging amount applicable to the locality. Payment for lodging, meals, and other per diem expenses The maximum per diem rate applicable to the locality .75 times the maximum per diem rate applicable to...

26 CFR 1.410(a)-4 - Maximum age conditions and time of participation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 5 2012-04-01 2011-04-01 true Maximum age conditions and time of participation.... § 1.410(a)-4 Maximum age conditions and time of participation. (a) Maximum age conditions—(1) General...) if the plan excludes from participation (on the basis of age) an employee who has attained an age...

26 CFR 1.410(a)-4 - Maximum age conditions and time of participation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 5 2011-04-01 2011-04-01 false Maximum age conditions and time of participation.... § 1.410(a)-4 Maximum age conditions and time of participation. (a) Maximum age conditions—(1) General...) if the plan excludes from participation (on the basis of age) an employee who has attained an age...

26 CFR 1.410(a)-4 - Maximum age conditions and time of participation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Maximum age conditions and time of participation... Maximum age conditions and time of participation. (a) Maximum age conditions—(1) General rule. A plan is... excludes from participation (on the basis of age) an employee who has attained an age specified by the plan...

The influence of screening of the polyion electrostatic potential on the counterion dynamics in polyelectrolyte solutions

NASA Astrophysics Data System (ADS)

Schipper, F. J. M.; Hollander, J. G.; Leyte, J. C.

1998-10-01

The self-diffusion coefficient of tetra-methylammonium counterion in solutions of polymethacrylic acid in 0953-8984/10/41/004/img1 has been measured over a broad polyion concentration range at a constant degree of neutralization and at different ratios of added monovalent or bivalent salt to polyions. A maximum counterion self-diffusion coefficient was observed as a function of polyion concentration. The value of the self-diffusion coefficient at the maximum did not depend on the valency of the added salt. The maximum was found at lower polymer concentrations and with a higher value, when the ratio of added salt to polyions was increased, as predicted by the Poisson-Boltzmann-Smoluchowski equation in the cylindrical cell model for polyelectrolytes. At higher polyion concentrations a maximum counterion self-diffusion coefficient against the ratio of added salt and polyions was observed, which has not been reported before. Upon increasing this ratio the electrostatic potential of the polyelectrolyte gets screened, leading to an increase of the counterion self-diffusion coefficient. Concentration effects of the added salt on the other hand ultimately lead to a decrease of the counterion self-diffusion coefficient, which explains the occurrence of a maximum.

Dissolution corrosion of 316L austenitic stainless steels in contact with static liquid lead-bismuth eutectic (LBE) at 500 °C

NASA Astrophysics Data System (ADS)

Lambrinou, Konstantina; Charalampopoulou, Evangelia; Van der Donck, Tom; Delville, Rémi; Schryvers, Dominique

2017-07-01

This work addresses the dissolution corrosion behaviour of 316L austenitic stainless steels. For this purpose, solution-annealed and cold-deformed 316L steels were simultaneously exposed to oxygen-poor (<10-8 mass%) static liquid lead-bismuth eutectic (LBE) for 253-3282 h at 500 °C. Corrosion was consistently more severe for the cold-drawn steels than the solution-annealed steel, indicating the importance of the steel thermomechanical state. The thickness of the dissolution-affected zone was non-uniform, and sites of locally-enhanced dissolution were occasionally observed. The progress of LBE dissolution attack was promoted by the interplay of certain steel microstructural features (grain boundaries, deformation twin laths, precipitates) with the dissolution corrosion process. The identified dissolution mechanisms were selective leaching leading to steel ferritization, and non-selective leaching; the latter was mainly observed in the solution-annealed steel. The maximum corrosion rate decreased with exposure time and was found to be inversely proportional to the depth of dissolution attack.

Control of Lead Poisoning in Children. (Pre-Publication Draft).

ERIC Educational Resources Information Center

Public Health Service (DHEW), Washington, DC. Bureau of Community Environmental Management.

This document presents information about aspects of the lead pollution problem that relate to children, suggests a community action program for controlling lead hazards, estimates the staff and other costs involved in developing such a program, and tells how to synthesize the program components for maximum effectiveness. The seven parts of the…

Adsorption of lead onto smectite from aqueous solution.

PubMed

Mhamdi, M; Galai, H; Mnasri, N; Elaloui, E; Trabelsi-Ayadi, M

2013-03-01

The purpose of this research is to study the effect of a new method of adsorption using membrane filtration to determine the maximum amount of lead adsorbed by clay and investigate the behavior of the clay after adsorption of the said metal. Treatment of wastewater contaminated with heavy metals depends on the characteristics of the effluent, the amount of final discharge, the cost of treatment, and the compatibility of the treatment process. The process of adsorption of heavy metals by clays may be a simple, selective, and economically viable alternative to the conventional physical-chemical treatment. This is justified by the importance of the surface developed by this material, the presence of negative charges on the said surface, the possibility of ion exchange taking place, and its wide availability in nature. The removal of lead from wastewater was studied by using the adsorption technique and using clay as the adsorbent. A method was optimized for adsorption through a membrane approaching natural adsorption. This new method is simple, selective, and the lead adsorption time is about 3 days. The various properties of clay were determined. It was observed that the cation exchange capacity of the clay was 56 meq/100 g of hydrated clay for the raw sample and 82 meq/100 g for the purified sample. The total surface area determined by the methylene blue method was equal to 556 and 783 m(2)/g for the raw and purified samples, respectively. The adsorption kinetics depends on several parameters. The Pb(II) clay, obeys the Langmuir, Freundlich, and the Elovich adsorption isotherms with high regression coefficients. The use of this adsorbent notably decreases the cost of treatment. It was concluded that clay shows a strong adsorption capacity on Pb(II), the maximum interaction occurring with purified clay treated at high concentration of lead. It is proposed that this adsorption through a membrane be extended for the treatment of effluents containing other metals.

Radiation exposure of the radiologist's eye lens during CT-guided interventions.

PubMed

Heusch, Philipp; Kröpil, Patric; Buchbender, Christian; Aissa, Joel; Lanzman, Rotem S; Heusner, Till A; Ewen, Klaus; Antoch, Gerald; Fürst, Günther

2014-02-01

In the past decade the number of computed tomography (CT)-guided procedures performed by interventional radiologists have increased, leading to a significantly higher radiation exposure of the interventionalist's eye lens. Because of growing concern that there is a stochastic effect for the development of lens opacification, eye lens dose reduction for operators and patients should be of maximal interest. To determine the interventionalist's equivalent eye lens dose during CT-guided interventions and to relate the results to the maximum of the recommended equivalent dose limit. During 89 CT-guided interventions (e.g. biopsies, drainage procedures, etc.) measurements of eye lens' radiation doses were obtained from a dedicated dosimeter system for scattered radiation. The sensor of the personal dosimeter system was clipped onto the side of the lead glasses which was located nearest to the CT gantry. After the procedure, radiation dose (µSv), dose rate (µSv/min) and the total exposure time (s) were recorded. For all 89 interventions, the median total exposure lens dose was 3.3 µSv (range, 0.03-218.9 µSv) for a median exposure time of 26.2 s (range, 1.1-94.0 s). The median dose rate was 13.9 µSv/min (range, 1.1-335.5 µSv/min). Estimating 50-200 CT-guided interventions per year performed by one interventionalist, the median dose of the eye lens of the interventional radiologist does not exceed the maximum of the ICRP-recommended equivalent eye lens dose limit of 20 mSv per year.

Selfsimilar time dependent shock structures

NASA Astrophysics Data System (ADS)

Beck, R.; Drury, L. O.

1985-08-01

Diffusive shock acceleration as an astrophysical mechanism for accelerating charged particles has the advantage of being highly efficient. This means however that the theory is of necessity nonlinear; the reaction of the accelerated particles on the shock structure and the acceleration process must be self-consistently included in any attempt to develop a complete theory of diffusive shock acceleration. Considerable effort has been invested in attempting, at least partially, to do this and it has become clear that in general either the maximum particle energy must be restricted by introducing additional loss processes into the problem or the acceleration must be treated as a time dependent problem (Drury, 1984). It is concluded that stationary modified shock structures can only exist for strong shocks if additional loss processes limit the maximum energy a particle can attain. This is certainly possible and if it occurs the energy loss from the shock will lead to much greater shock compressions. It is however equally possible that no such processes exist and we must then ask what sort of nonstationary shock structure develops. The ame argument which excludes stationary structures also rules out periodic solutions and indeed any solution where the width of the shock remains bounded. It follows that the width of the shock must increase secularly with time and it is natural to examine the possibility of selfsimilar time dependent solutions.

Selfsimilar time dependent shock structures

NASA Technical Reports Server (NTRS)

Beck, R.; Drury, L. O.

1985-01-01

Diffusive shock acceleration as an astrophysical mechanism for accelerating charged particles has the advantage of being highly efficient. This means however that the theory is of necessity nonlinear; the reaction of the accelerated particles on the shock structure and the acceleration process must be self-consistently included in any attempt to develop a complete theory of diffusive shock acceleration. Considerable effort has been invested in attempting, at least partially, to do this and it has become clear that in general either the maximum particle energy must be restricted by introducing additional loss processes into the problem or the acceleration must be treated as a time dependent problem (Drury, 1984). It is concluded that stationary modified shock structures can only exist for strong shocks if additional loss processes limit the maximum energy a particle can attain. This is certainly possible and if it occurs the energy loss from the shock will lead to much greater shock compressions. It is however equally possible that no such processes exist and we must then ask what sort of nonstationary shock structure develops. The ame argument which excludes stationary structures also rules out periodic solutions and indeed any solution where the width of the shock remains bounded. It follows that the width of the shock must increase secularly with time and it is natural to examine the possibility of selfsimilar time dependent solutions.

Application of Box-Behnken design for modeling of lead adsorption onto unmodified and NaCl-modified zeolite NaA obtained from biosilica.

PubMed

Terzioğlu, Pinar; Yücel, Sevil; Öztürk, Mehmet

2017-01-01

The main objective of the present study was to optimize lead adsorption onto zeolite NaA. For this purpose, to synthesize zeolite NaA under hydrothermal conditions, local wheat husk was precleaned with chemical treatment using hydrochloric acid solution. The unmodified (ZU) and NaCl-modified (ZN) zeolites were characterized by Brunauer-Emmett-Teller, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffraction. The optimization of adsorption process was examined using Box-Behnken Experimental Design in response surface methodology by Design Expert Version 7.0.0 (Stat-Ease, USA). The effects of initial lead (II) concentration, temperature, and time were selected as independent variables. Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for both adsorbents. Optimum process conditions for lead (II) adsorption onto ZU and ZN were found to be 64.40°C and 64.80°C, respectively, and 90.80 min, and 350 mg L -1 initial lead(II) concentration for both adsorbents. Under these conditions, maximum adsorption capacities of ZU and ZN for lead (II) were 293.38 mg g -1 and 321.85 mg g -1 , respectively.

IRT Item Parameter Recovery with Marginal Maximum Likelihood Estimation Using Loglinear Smoothing Models

ERIC Educational Resources Information Center

Casabianca, Jodi M.; Lewis, Charles

2015-01-01

Loglinear smoothing (LLS) estimates the latent trait distribution while making fewer assumptions about its form and maintaining parsimony, thus leading to more precise item response theory (IRT) item parameter estimates than standard marginal maximum likelihood (MML). This article provides the expectation-maximization algorithm for MML estimation…

Parametric Imaging Of Digital Subtraction Angiography Studies For Renal Transplant Evaluation

NASA Astrophysics Data System (ADS)

Gallagher, Joe H.; Meaney, Thomas F.; Flechner, Stuart M.; Novick, Andrew C.; Buonocore, Edward

1981-11-01

A noninvasive method for diagnosing acute tubular necrosis and rejection would be an important tool for the management of renal transplant patients. From a sequence of digital subtraction angiographic images acquired after an intravenous injection of radiographic contrast material, the parametric images of the maximum contrast, the time when the maximum contrast is reached, and two times the time at which one half of the maximum contrast is reached are computed. The parametric images of the time when the maximum is reached clearly distinguish normal from abnormal renal function. However, it is the parametric image of two times the time when one half of the maximum is reached which provides some assistance in differentiating acute tubular necrosis from rejection.

Extratropical Cyclones Leading to Extreme Weather Events over Central and Eastern North America

NASA Astrophysics Data System (ADS)

Bentley, Alicia M.

Cool-season extreme weather events (EWEs) occurring over central and eastern North America are typically associated with strong extratropical cyclones (ECs) that are governed by varying combinations of baroclinic, diabatic, and barotropic processes. This dissertation investigates the climatology, evolution, and predictability of ECs leading to EWEs over central and eastern North America, and provides a foundation on which to compare ECs leading to EWEs to ordinary ECs forming over and traversing the same regions. A climatology of ECs leading to EWEs over central and eastern North America during October-March 1979-2016 reveals that these ECs typically form 1) in the lee of the Rocky Mountains, 2) over the south central U.S., and 3) along the east coast of North America at latitudes equatorward of the typical genesis locations of ordinary ECs. ECs leading to EWEs included in the climatology form most frequently in November and March, when the seasonal alignment of baroclinic and convectively driven forcings occurs. Consistent with previous studies of North American ECs, the location and frequency of ECs leading to EWEs are partially determined by the states of the Pacific-North American pattern and the North Atlantic Oscillation. Metrics representing baroclinic, diabatic, and barotropic processes are formulated in this dissertation and are used to determine the combinations of baroclinic, diabatic, and barotropic processes associated with the formation and maintenance of ordinary ECs and ECs leading to EWEs. These metrics reveal that ECs leading to EWEs are associated with contributions from baroclinic, diabatic, and barotropic processes that are 1) similar to those associated with ordinary ECs at the time of formation (t0) and 2) considerably larger than those associated with ordinary ECs at the time of maximum intensity (tmax). Baroclinic processes typically contribute more than diabatic and barotropic processes throughout the evolution of ECs leading to EWEs. Diabatic processes typically contribute more during the intensification of ECs leading to EWEs than during their maintenance after tmax, whereas barotropic processes typically contribute more during the maintenance of ECs leading to EWEs after tmax than during their intensification. The relative contributions from baroclinic, diabatic, and barotropic processes during the evolution of ECs leading to EWEs are also shown to differ based on their genesis location. The 1.0° NOAA Global Ensemble Forecast System (GEFS) reforecast dataset is used in this dissertation to evaluate the forecast skill associated with ordinary ECs and ECs leading to EWEs at 0-192-h lead times. Ordinary ECs are consistently too slow and left of track in the GEFS, and are often too weak at longer lead times. ECs leading to EWEs are consistently too weak, fast, and right of track in the GEFS at longer lead times, and consistently too strong, slow, and left of track at shorter lead times. The positions of ordinary ECs are forecast with less skill and more spread than the positions of ECs leading to EWEs in the GEFS, whereas the intensities of ordinary ECs and ECs leading to EWEs are forecast with similar skill and spread. Locations over central and eastern North America where the positions and intensities of ordinary ECs and ECs leading to EWEs are frequently forecast with relatively low and high skill and spread in the GEFS are also identified.

Study on processing parameters of glass cutting by nanosecond 532 nm fiber laser

NASA Astrophysics Data System (ADS)

Wang, Jin; Gao, Fan; Xiong, Baoxing; Zhang, Xiang; Yuan, Xiao

2018-03-01

The processing parameters of soda-lime glass cutting with several nanosecond 532 nm pulsed fiber laser are studied in order to obtain sufficiently large ablation rate and better processing quality. The influences of laser processing parameters on effective cutting speed and cutting quality of 1 2 mm thick soda-lime glass are studied. The experimental results show that larger laser pulse energy will lead to higher effective cutting speed and larger maximum edge collapse of the front side of the glass samples. Compared with that of 1.1 mm thick glass samples, the 2.0 mm thick glass samples is more difficult to cut. With the pulse energy of 51.2 μJ, the maximum edge collapse is more than 200 μm for the 2.0 mm thick glass samples. In order to achieve the high effective cutting speed and good cutting quality at the same time, the dual energy overlapping method is used to obtain the better cutting performance for the 2.0 mm thick glass samples, and the cutting speed of 194 mm/s and the maximum edge collapse of less than 132 μm are realized.

Maruhn-Greiner Maximum for Confirmation of Low Energy Nuclear Reactions (LENR) via a Compound Nucleus with Double Magic Numbers

NASA Astrophysics Data System (ADS)

Hora, Heinrich; Miley, George

2007-03-01

One of the most convincing facts about LENR due to deuterons (ds) or protons of very high concentration in host metals of palladium is the measurement of the large scale minimum in the reaction probability with product elements centered around the nucleon number A = 153. The local maximum was measured in this region is similar to fission of uranium at A = 119 where the local maximum follows the Maruhn-Greiner mechanism^1. We suggest this phenomenon can be explained by the strong screening of the Maxwellian ds on the degenerate rigid electron background within the swimming electrons at the metal surface or thin filem interfaces. The deuterons behave like neutrals at distances of above 2 picometers (pm) and form clusters due to soft attraction in the range of thermal energy; 10 pm diameter clusters can react over long time scales (10^6 s) with Pd leading to double magic number compound nuclei 306x126 decaying via fission to an A=153 element distribution. J. Maruhn et al, Phys. Rev. Letters 32, 548 (1974) H. Hora, G.H. Miley, CzechJ. Phys. 48, 1111 (1998)

Analysis of the aerodynamic interaction between two plunging plates in tandem at low Reynolds number for maximum propulsive efficiency

NASA Astrophysics Data System (ADS)

Ortega-Casanova, Joaquin; Fernandez-Feria, Ramon

2015-11-01

The thrust generated by two heaving plates in tandem is analysed for two particular sets of configurations of interest in forward flight: a plunging leading plate with the trailing plate at rest, and the two plates heaving with the same frequency and amplitude, but varying the phase difference. The thrust efficiency of the leading plate is augmented in relation to a single plate heaving with the same frequency and amplitude in most cases. In the first configuration, we characterize the range of nondimensional heaving frequencies and amplitudes of the leading plate for which the stationary trailing plate contributes positively to the global thrust. The maximum global thrust efficiency, reached for an advance ratio slightly less than unity and a reduced frequency close to 5, is about the same as the maximum efficiency for an isolated plate. But for low frequencies the tandem configuration with the trailing plate at rest is more thrust efficient than the isolated plate. In the second configuration, we find that the maximum thrust efficiency is reached for a phase lag of 180o (counterstroking), particularly for an advance ratio unity and a reduced frequency 4.4, and it is practically the same as in the other configuration and that for a single plate. Supported by the Ministerio de Economía y Competitividad of Spain Grant no. DPI2013-40479-P.

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

Kaplan, C.R.; Shaddix, C.R.; Smyth, K.C.

This paper presents time-dependent numerical simulations of both steady and time-varying CH{sub 4}/air diffusion flames to examine the differences in combustion conditions which lead to the observed enhancement in soot production in the flickering flames. The numerical model solves the two-dimensional, time-dependent, reactive-flow Navier-Stokes equations coupled with submodels for soot formation and radiation transport. Qualitative comparisons between the experimental and computed steady flame show good agreement for the soot burnout height and overall flame shape except near the burner lip. Quantitative comparisons between experimental and computed radial profiles of temperature and soot volume fraction for the steady flame show goodmore » to excellent agreement at mid-flame heights, but some discrepancies near the burner lip and at high flame heights. For the time-varying CH{sub 4}/air flame, the simulations successfully predict that the maximum soot concentration increases by over four times compared to the steady flame with the same mean fuel and air velocities. By numerically tracking fluid parcels in the flowfield, the temperature and stoichiometry history were followed along their convective pathlines. Results for the pathline which passes through the maximum sooting region show that flickering flames exhibit much longer residence times during which the local temperatures and stoichiometries are favorable for soot production. The simulations also suggest that soot inception occurs later in flickering flames, and at slightly higher temperatures and under somewhat leaner conditions compared to the steady flame. The integrated soot model of Syed et al., which was developed from a steady CH{sub 4}/air flame, successfully predicts soot production in the time-varying CH{sub 4}/air flames.« less

Real-time Interplanetary Shock Prediction System

NASA Astrophysics Data System (ADS)

Vandegriff, J. D.; Ho, G. C.; Plauger, J. M.

2002-05-01

We are creating a system to predict the arrival times and maximum intensities of energetic storm particle (ESP) events at the earth using particle fluxes measured by the EPAM instrument aboard NASA's ACE spacecraft. Real-time flux measurements, consisting of 5 minute averages made available 24 hours per day by the NOAA Space Environment Center, are fed into algorithms looking for characteristic changes in flux, velocity dispersion, and anisotropy. These quantities typically show changes up to 3 hours before shock passage, and thus we expect our system to deliver enhanced probabilities for shock arrival with approximately the same lead time. Forecasting information will be made publicly available through http://sd-www.jhuapl.edu/ACE/EPAM/, the Johns Hopkins University Applied Physics Lab web site for the ACE/EPAM instrument. Early results on the training of our algorithms and comparisons with past shock data will be presented.

Statistical fluctuations in cooperative cyclotron radiation

NASA Astrophysics Data System (ADS)

Anishchenko, S. V.; Baryshevsky, V. G.

2018-01-01

Shot noise is the cause of statistical fluctuations in cooperative cyclotron radiation generated by an ensemble of electrons oscillating in magnetic field. Autophasing time - the time required for the cooperative cyclotron radiation power to peak - is the critical parameter characterizing the dynamics of electron-oscillators interacting via the radiation field. It is shown that premodulation of charged particles leads to a considerable narrowing of the autophasing time distribution function for which the analytic expression is obtained. When the number of particles Ne exceeds a certain value that depends on the degree to which the particles have been premodulated, the relative root-mean-square deviation (RMSD) of the autophasing time δT changes from a logarithmic dependence on Ne (δT ∼ 1 / lnNe) to square-root (δT ∼ 1 /√{Ne }). A slight energy spread (∼4%) results in a twofold drop of the maximum attainable power of cooperative cyclotron radiation.

Extension of classical hydrological risk analysis to non-stationary conditions due to climate change - application to the Fulda catchment, Germany

NASA Astrophysics Data System (ADS)

Fink, G.; Koch, M.

2010-12-01

An important aspect in water resources and hydrological engineering is the assessment of hydrological risk, due to the occurrence of extreme events, e.g. droughts or floods. When dealing with the latter - as is the focus here - the classical methods of flood frequency analysis (FFA) are usually being used for the proper dimensioning of a hydraulic structure, for the purpose of bringing down the flood risk to an acceptable level. FFA is based on extreme value statistics theory. Despite the progress of methods in this scientific branch, the development, decision, and fitting of an appropriate distribution function stills remains a challenge, particularly, when certain underlying assumptions of the theory are not met in real applications. This is, for example, the case when the stationarity-condition for a random flood time series is not satisfied anymore, as could be the situation when long-term hydrological impacts of future climate change are to be considered. The objective here is to verify the applicability of classical (stationary) FFA to predicted flood time series in the Fulda catchment in central Germany, as they may occur in the wake of climate change during the 21st century. These discharge time series at the outlet of the Fulda basin have been simulated with a distributed hydrological model (SWAT) that is forced by predicted climate variables of a regional climate model for Germany (REMO). From the simulated future daily time series, annual maximum (extremes) values are computed and analyzed for the purpose of risk evaluation. Although the 21st century estimated extreme flood series of the Fulda river turn out to be only mildly non-stationary, alleviating the need for further action and concern at the first sight, the more detailed analysis of the risk, as quantified, for example, by the return period, shows non-negligent differences in the calculated risk levels. This could be verified by employing a new method, the so-called flood series maximum analysis (FSMA) method, which consists in the stochastic simulation of numerous trajectories of a stochastic process with a given GEV-distribution over a certain length of time (> larger than a desired return period). Then the maximum value for each trajectory is computed, all of which are then used to determine the empirical distribution of this maximum series. Through graphical inversion of this distribution function the size of the design flood for a given risk (quantile) and given life duration can be inferred. The results of numerous simulations show that for stationary flood series, the new FSMA method results, expectedly, in nearly identical risk values as the classical FFA approach. However, once the flood time series becomes slightly non-stationary - for reasons as discussed - and regardless of whether the trend is increasing or decreasing, large differences in the computed risk values for a given design flood occur. Or in other word, for the same risk, the new FSMA method would lead to different values in the design flood for a hydraulic structure than the classical FFA method. This, in turn, could lead to some cost savings in the realization of a hydraulic project.

[Clinical manifestations of lead levels in children exposed to automobile battery recycling processes in Soacha and Bogotá, D.C].

PubMed

Hurtado, Carlos Mauricio; Gutiérrez, Myriam; Echeverry, Jairo

2008-03-01

Lead is a harmless metal if not handled directly in the industrial process. Even thought lead has been eliminated from the gasoline in many countries, automobile battery recycling continues to be a potential source of exposure and intoxication for the workers and their families, particularly of low income. The current investigation was initiated after an index case of lead poisoning was reported from Soacha, Cundinamarca, in central Colombia. Clinical investigation established lead levels and lead poison frequency in children with para-occupational lead exposure in the process of recycling automobile batteries. This was designed as a descriptive study, with selection of subjects with high risk of possible lead exposure. Minors, mostly of school age were recruited based on referral by relatives, neighbors or acquaintances, all of whom were involved in para-occupational exposure. Thirty two children, less than 12 years old (majority school age), were included. General and specific examinations of the children were made, and blood samples were taken for lead and hematological determinations. All subjects showed high levels of lead (2-9 times the maximum acceptable value) and, according to established criteria, two-thirds were rated as severely poisoned. The children with high levels of lead had tendency toward more specific hematological compromise and showing black gingival bordering (Burton border). This study communicates to the sanitary authorities and government a clear sign of alarm in that measures must be taken to diminish the occupational or para-occupational lead exposure of children by way of the automobile battery recycling industry.

Effect of Synthesis Procedure on Thermoelectric Property of SiGe Alloy

NASA Astrophysics Data System (ADS)

Li, Jing; Han, Jun; Jiang, Tao; Luo, Lili; Xiang, Yongchun

2018-05-01

SiGe thermoelectric material has been synthesized by ball milling combined with hot pressing (HP) or spark plasma sintering (SPS). Effects of ball milling time, powder to ball weight ratio and sintering method on microstructure and thermoelectric properties of SiGe are studied. The results show that longer ball milling time leads to decreased density and worse electrical properties. In the sintering process, SPS results in much larger density and better electrical properties than HP. The Si0.795Ge0.2B0.005 sample prepared by 2 h ball milling combined with SPS obtains a maximum power factor of 3.0 mW m-1 K-2 at 860 K and ZT of 0.95 at 1000 K.

Modeling polar cap F-region patches using time varying convection

NASA Technical Reports Server (NTRS)

Sojka, J. J.; Bowline, M. D.; Schunk, R. W.; Decker, D. T.; Valladares, C. E.; Sheehan, R.; Anderson, D. N.; Heelis, R. A.

1993-01-01

Creation of polar cap F-region patches are simulated for the first time using two independent physical models of the high latitude ionosphere. The patch formation is achieved by temporally varying the magnetospheric electric field (ionospheric convection) input to the models. The imposed convection variations are comparable to changes in the convection that result from changes in the B(y) IMF component for southward IMF. Solar maximum-winter simulations show that simple changes in the convection pattern lead to significant changes in the polar cap plasma structuring. Specifically, in winter, as enhanced dayside plasma convects into the polar cap to form the classic tongue-of-ionization the convection changes produce density structures that are indistinguishable from the observed patches.

Lead sorption by waste biomass of hazelnut and almond shell.

PubMed

Pehlivan, Erol; Altun, Türkan; Cetin, Serpil; Iqbal Bhanger, M

2009-08-15

The potential to remove Pb(2+) ion from aqueous solutions using the shells of hazelnut (HNS) (Corylus avellana) and almond (AS) (Prunus dulcis) through biosorption was investigated in batch experiments. The main parameters influencing Pb(2+) ion sorption on HNS and AS were: initial metal ion concentration, amount of adsorbent, contact time and pH value of solution. The influences of initial Pb(2+) ion concentration (0.1-1.0mM), pH (2-9), contact time (10-240 min) and adsorbent amount (0.1-1.0 g) have been investigated. Equilibrium isotherms have been measured and modelled. Adsorption of Pb(2+) ions was in all cases pH-dependent showing a maximum at equilibrium pH values between 6.0 and 7.0, depending on the biomaterial, that corresponded to equilibrium pH values of 6.0 for HNS and 7.0 for AS. The equilibrium sorption capacities of HNS and AS were 28.18 and 8.08 mg/g for lead, respectively after equilibrium time of 2h. The adsorption data fit well with the Langmuir isotherm model and the experimental result inferred that adsorption, chelation and ion exchange are major adsorption mechanisms for binding Pb(2+) ion to the sorbents.

Development of Advanced High Lift Leading Edge Technology for Laminar Flow Wings

NASA Technical Reports Server (NTRS)

Bright, Michelle M.; Korntheuer, Andrea; Komadina, Steve; Lin, John C.

2013-01-01

This paper describes the Advanced High Lift Leading Edge (AHLLE) task performed by Northrop Grumman Systems Corporation, Aerospace Systems (NGAS) for the NASA Subsonic Fixed Wing project in an effort to develop enabling high-lift technology for laminar flow wings. Based on a known laminar cruise airfoil that incorporated an NGAS-developed integrated slot design, this effort involved using Computational Fluid Dynamics (CFD) analysis and quality function deployment (QFD) analysis on several leading edge concepts, and subsequently down-selected to two blown leading-edge concepts for testing. A 7-foot-span AHLLE airfoil model was designed and fabricated at NGAS and then tested at the NGAS 7 x 10 Low Speed Wind Tunnel in Hawthorne, CA. The model configurations tested included: baseline, deflected trailing edge, blown deflected trailing edge, blown leading edge, morphed leading edge, and blown/morphed leading edge. A successful demonstration of high lift leading edge technology was achieved, and the target goals for improved lift were exceeded by 30% with a maximum section lift coefficient (Cl) of 5.2. Maximum incremental section lift coefficients ( Cl) of 3.5 and 3.1 were achieved for a blown drooped (morphed) leading edge concept and a non-drooped leading edge blowing concept, respectively. The most effective AHLLE design yielded an estimated 94% lift improvement over the conventional high lift Krueger flap configurations while providing laminar flow capability on the cruise configuration.

An Earthquake Source Sensitivity Analysis for Tsunami Propagation in the Eastern Mediterranean

NASA Astrophysics Data System (ADS)

Necmioglu, Ocal; Meral Ozel, Nurcan

2013-04-01

An earthquake source parameter sensitivity analysis for tsunami propagation in the Eastern Mediterranean has been performed based on 8 August 1303 Crete and Dodecanese Islands earthquake resulting in destructive inundation in the Eastern Mediterranean. The analysis involves 23 cases describing different sets of strike, dip, rake and focal depth, while keeping the fault area and displacement, thus the magnitude, same. The main conclusions of the evaluation are drawn from the investigation of the wave height distributions at Tsunami Forecast Points (TFP). The earthquake vs. initial tsunami source parameters comparison indicated that the maximum initial wave height values correspond in general to the changes in rake angle. No clear depth dependency is observed within the depth range considered and no strike angle dependency is observed in terms of amplitude change. Directivity sensitivity analysis indicated that for the same strike and dip, 180° shift in rake may lead to 20% change in the calculated tsunami wave height. Moreover, an approximately 10 min difference in the arrival time of the initial wave has been observed. These differences are, however, greatly reduced in the far field. The dip sensitivity analysis, performed separately for thrust and normal faulting, has both indicated that an increase in the dip angle results in the decrease of the tsunami wave amplitude in the near field approximately 40%. While a positive phase shift is observed, the period and the shape of the initial wave stays nearly the same for all dip angles at respective TFPs. These affects are, however, not observed at the far field. The resolution of the bathymetry, on the other hand, is a limiting factor for further evaluation. Four different cases were considered for the depth sensitivity indicating that within the depth ranges considered (15-60 km), the increase of the depth has only a smoothing effect on the synthetic tsunami wave height measurements at the selected TFPs. The strike sensitivity analysis showed clear phase shift with respect to the variation of the strike angles, without leading to severe variation of the initial and maximum waves at locations considered. Travel time maps for two cases corresponding to difference in the strike value (60° vs 150°) presented a more complex wave propagation for the case with 60° strike angle due to the fact that the normal of the fault plane is orthogonal to the main bathymetric structure in the region, namely the Eastern section of the Hellenic Arc between Crete and Rhodes Islands. For a given set of strike, dip and focal depth parameters, the effect of the variation in the rake angle has been evaluated in the rake sensitivity analysis. A waveform envelope composed of symmetric synthetic recordings at one TFPs could be clearly observed as a result of rake angle variations in 0-180° range. This could also lead to the conclusion that for a given magnitude (fault size and displacement), the expected maximum and minimum tsunami wave amplitudes could be evaluated as a waveform envelope rather limited to a single point of time or amplitude. The Evaluation of the initial wave arrival times follows an expected pattern controlled by the distance, wheras maximum wave arrival time distribution presents no clear pattern. Nevertheless, the distribution is rather concentrated in time domain for some TFPs. Maximum positive and minimum negative wave amplitude distributions indicates a broader range for a subgroup of TFPs, wheras for the remaining TFPs the distributions are narrow. Any deviation from the expected trend of calculating narrower ranges of amplitude distributions could be interpreted as the result o the bathymetry and focusing effects. As similar studies conducted in the different parts of the globe indicated, the main characteristics of the tsunami propagation are unique for each basin. It should be noted, however, that the synthetic measurements obtained at the TFPs in the absence of high-resolution bathymetric data, should be considered only an overall guidance. The results indicate the importance of the accuracy of earthquake source parameters for reliable tsunami predictions and the need for high-resolution bathymetric data to be able to perform calculations with higher accuracy. On the other hand, this study did not address other parameters, such as heterogeneous slip distribution and rupture duration, which affect the tsunami initiation and propagation process.

Candle Soot-Driven Performance Enhancement in Pyroelectric Energy Conversion

NASA Astrophysics Data System (ADS)

Azad, Puneet; Singh, V. P.; Vaish, Rahul

2018-05-01

We observed substantial enhancement in pyroelectric output with the help of candle soot coating on the surface of lead zirconate titanate (PZT). Candle soot of varying thicknesses was coated by directly exposing pyroelectric material to the candle flame. The open-circuit pyroelectric voltage and closed-circuit pyroelectric current were recorded while applying infrared heating across the uncoated and candle soot-coated samples for different heating and cooling cycles. In comparison to the uncoated sample, the maximum open-circuit voltage improves seven times for the candle soot-coated sample and electric current increases by eight times across a resistance of 10Å. Moreover, the harvested energy is enhanced by 50 times for candle soot-coated sample. Results indicate that candle soot coating is an effective and economic method to improve infrared sensing performance of pyroelectric materials.

Calcination Conditions on the Properties of Porous TiO2 Film

NASA Astrophysics Data System (ADS)

Zhang, Wenjie; Pei, Xiaobei; Bai, Jiawei; He, Hongbo

2014-03-01

Porous TiO2 films were deposited on SiO2 precoated glass-slides by sol-gel method using PEG1000 as template. The strongest XRD diffraction peak at 2θ = 25.3° is attributed to [101] plane of anatase TiO2 in the film. The increases of calcination temperature and time lead to stronger diffraction peak intensity. High transmittance and blue shift of light absorption edge are the properties of the film prepared at high calcination temperature. The average pore size of the films increases with the increasing calcination temperature as the result of TiO2 crystalline particles growing up and aggregation, accompanied with higher specific surface area. Photocatalytic activity of porous TiO2 films increases with the increasing calcination temperature. The light absorption edge of the films slightly moves to longer wavelength region along with the increasing calcination time. The mesoporous film calcinated at 500 °C for 2 h has the highest transmittance, the maximum surface area, and the maximum total pore volume. Consequently, the optimum degradation activity is achieved on the porous TiO2 film calcinated at 500 °C for 2 h.

Uptake of uranium from seawater by amidoxime-based polymeric adsorbent marine testing

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

Tsouris, C.; Kim, J.; Oyola, Y.

2013-07-01

Amidoxime-based polymer adsorbents in the form of functionalized fibers were prepared at the Oak Ridge National Laboratory (ORNL) and screened in laboratory experiments, in terms of uranium uptake capacity, using spiked uranium solution and seawater samples. Batch laboratory experiments conducted with 5-gallon seawater tanks provided equilibrium information. Based on results from 5-gallon experiments, the best adsorbent was selected for field-testing of uranium adsorption from seawater. Flow-through column tests have been performed at different marine sites to investigate the uranium uptake rate and equilibrium capacity under diverse biogeochemistry. The maximum amount of uranium uptake from seawater tests at Sequim, WA, wasmore » 3.3 mg U/g adsorbent after eight weeks of contact of the adsorbent with seawater. This amount was three times higher than the maximum adsorption capacity achieved in this study by a leading adsorbent developed by the Japan Atomic Energy Agency (JAEA), which was 1.1 mg U/g adsorbent at equilibrium. The initial uranium uptake rate of the ORNL adsorbent was 2.6 times higher than that of the JAEA adsorbent under similar conditions. A mathematical model derived from the mass balance of uranium was employed to describe the data. (authors)« less

Real-Time Noise Reduction for Mossbauer Spectroscopy through Online Implementation of a Modified Kalman Filter

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

Abrecht, David G.; Schwantes, Jon M.; Kukkadapu, Ravi K.

2015-02-01

Spectrum-processing software that incorporates a gaussian smoothing kernel within the statistics of first-order Kalman filtration has been developed to provide cross-channel spectral noise reduction for increased real-time signal-to-noise ratios for Mossbauer spectroscopy. The filter was optimized for the breadth of the gaussian using the Mossbauer spectrum of natural iron foil, and comparisons between the peak broadening, signal-to-noise ratios, and shifts in the calculated hyperfine parameters are presented. The results of optimization give a maximum improvement in the signal-to-noise ratio of 51.1% over the unfiltered spectrum at a gaussian breadth of 27 channels, or 2.5% of the total spectrum width. Themore » full-width half-maximum of the spectrum peaks showed an increase of 19.6% at this optimum point, indicating a relatively weak increase in the peak broadening relative to the signal enhancement, leading to an overall increase in the observable signal. Calculations of the hyperfine parameters showed no statistically significant deviations were introduced from the application of the filter, confirming the utility of this filter for spectroscopy applications.« less

Multi-responses optimization of simultaneous biosorption of cationic dyes by live yeast Yarrowia lipolytica 70562 from binary solution: Application of first order derivative spectrophotometry.

PubMed

Dil, Ebrahim Alipanahpour; Ghaedi, Mehrorang; Ghezelbash, Gholam Reza; Asfaram, Arash

2017-05-01

Present study is based on application of live yeast Yarrowia lipolytica 70562 as new biosorbent was investigated for the simultaneous biosorption of Crystal Violet (CV) and Brilliant Green (BG) from wastewater. The effect of operating parameters such as initial dye concentrations (6-14mgL -1 ), solution pH (4.0-8.0) and contact time (4-20h) was investigated by response surface methodology (RSM) for modeling and optimization of biosorption process and accordingly the best operational conditions was set as: initial CV and BG concentration of 8.0, and 10mgL -1 , pH of 7.0 and contact time of 16h. Above specified conditions lead to achievement of maximum biosorption of 98.823% and 99.927% for CV and BG dyes, respectively. The experimental equilibrium data well explained according to Langmuir isotherm model with maximum biosorption capacity of 65.359 and 56.497mgg -1 for BG and CV, respectively. The second order and intraparticle diffusion models as cooperative mechanism has high efficiency and performance for interpretation of real data. Copyright © 2017. Published by Elsevier Inc.

Cabin air quality: indoor pollutants and climate during intercontinental flights with and without tobacco smoking.

PubMed

Lindgren, T; Norbäck, D

2002-12-01

The aim was to determine cabin air quality and in-flight exposure for cabin attendants of specific pollutants during intercontinental flights. Measurements of air humidity, temperature, carbon dioxide (CO2), respirable particles, ozone (O3), nitrogen dioxide (NO2) and formaldehyde were performed during 26 intercontinental flights with Boeing 767-300 with and without tobacco smoking onboard. The mean temperature in cabin was 22.2 degrees C (range 17.4-26.8 degrees C), and mean relative air humidity was 6% (range 1-27%). The CO2 concentration during cruises was below the recommended limit of 1000 ppm during 96% of measured time. Mean indoor concentration of NO2 and O3, were 14.1 and 19.2 micrograms/m3, with maximum values of 37 and 66 micrograms/m3, respectively. The concentration of formaldehyde was below the detection limit (< 5 micrograms/m3), in most samples (77%), and the maximum value was 15 micrograms/m3. The mean concentration of respirable particles in the rear part of the aircraft (AFT galley area) was much higher (49 micrograms/m3) during smoking as compared with non-smoking conditions (3 micrograms/m3) (P < 0.001), with maximum values of 253 and 7 micrograms/m3. In conclusion, air humidity is very low on intercontinental flights, and the large variation of temperature shows a need for better temperature control. Tobacco smoking onboard leads to a significant pollution of respirable particles, particularly in the rear part of the cabin. The result supports the view that despite the high air exchange rate and efficient air filtration, smoking in commercial aircraft leads to a significant pollution and should be prohibited.

Transient AC voltage related phenomena for HVDC schemes connected to weak AC systems

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

Pilotto, L.A.S.; Szechtman, M.; Hammad, A.E.

1992-07-01

In this paper a didactic explanation of voltage stability associated phenomena at HVDC terminals is presented. Conditions leading to ac voltage collapse problems are identified. A mechanism that excites control-induced voltage oscillations is shown. The voltage stability factor is used for obtaining the maximum power limits of ac/dc systems operating with different control strategies. Correlation to Pd {times} Id curves is given. Solutions for eliminating the risks of voltage collapse and for avoiding control-induced oscillations are discussed. The results are supported by detailed digital simulations of a weak ac/dc system using EMTP.

40 CFR 464.22 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

....399 TSS 1.52 0.598 pH (1) (1) 1 Within the range of 7.0 to 10.0 at all times. Maximum for any 1 day....39 0.0088 Zinc (T) 1.14 0.43 0.0108 Oil and grease 30 10 0.199 TSS 38 15 0.399 pH (3) (3) (3) 1 kg....506 Lead (T) 0.952 0.47 Zinc (T) 1.37 0.518 Oil and grease 36.2 12.1 TSS 45.8 18.1 pH (1) (1) 1 Within...

Long-term trends in daily temperature extremes in Iraq

NASA Astrophysics Data System (ADS)

Salman, Saleem A.; Shahid, Shamsuddin; Ismail, Tarmizi; Chung, Eun-Sung; Al-Abadi, Alaa M.

2017-12-01

The existence of long-term persistence (LTP) in hydro-climatic time series can lead to considerable change in significance of trends. Therefore, past findings of climatic trend studies that did not consider LTP became a disputable issue. A study has been conducted to assess the trends in temperature and temperature extremes in Iraq in recent years (1965-2015) using both ordinary Mann-Kendal (MK) test; and the modified Mann-Kendall (m-MK) test, which can differentiate the multi-decadal oscillatory variations from secular trends. Trends in annual and seasonal minimum and maximum temperatures, diurnal temperature range (DTR), and 14 temperature-related extremes were assessed. MK test detected the significant increases in minimum and maximum temperature at all stations, where m-MK test detected at 86% and 80% of all stations, respectively. The temperature in Iraq is increasing 2 to 7 times faster than global temperature rise. The minimum temperature is increasing more (0.48-1.17 °C/decade) than maximum temperature (0.25-1.01 °C/decade). Temperature rise is higher in northern Iraq and in summer. The hot extremes particularly warm nights are increasing all over Iraq at a rate of 2.92-10.69 days/decade, respectively. On the other hand, numbers of cold days are decreasing at some stations at a rate of - 2.65 to - 8.40 days/decade. The use of m-MK test along with MK test confirms the significant increase in temperature and some of the temperature extremes in Iraq. This study suggests that trends in many temperature extremes in the region estimated in previous studies using MK test may be due to natural variability of climate, which empathizes the need for validation of the trends by considering LTP in time series.

The large tsunami of 26 December 2004: Field observations and eyewitnesses accounts from Sri Lanka, Maldives Is. and Thailand

NASA Astrophysics Data System (ADS)

Papadopoulos, Gerassimos A.; Caputo, Riccardo; McAdoo, Brian; Pavlides, Spyros; Karastathis, Vassilios; Fokaefs, Anna; Orfanogiannaki, Katerina; Valkaniotis, Sotiris

2006-02-01

Post-event field surveys were conducted and measurements were taken in Sri Lanka and Maldives about two weeks after the catastrophic Indian Ocean tsunami of 26 December 2004. The measurements taken were cross-checked after interviewing with local people. In the southwest, south and east coastal zones of Sri Lanka maximum water levels ranging from h = 3 m to h = 11 m a.m.s.l. were estimated. The highest values observed were in the south of the island: Galle h ˜ 10 m, Hambantota h ˜ 11m. Maximum inundation of d ˜ 2 km was observed in Hambantota. The heavy destruction and thousands of victims caused in coastal communities, buildings and infrastructure, like railways and bridges, is attributed not only to physical parameters, like the strength of the tsunami hydrodynamic flow, coastal geomorphology and the wave erosional action in soil, but also to anthropogenic factors including the increased vulnerability of the non-RC buildings and the high population density. Local people usually described the tsunami as a series of three main waves. The leading wave phase was only a silent sea level rise of h ≤ 1.5 m and d ≤ 150 m, while the second wave was the strongest one. The first two waves occurred between 09:00 and 09:30 local time, depending on the locality. It is well documented that near Galle, southern part, the strong wave arrived at 09:25:30. In the west coast the third wave was a late arrival which possibly represents reflection phases. In Maldives, three waves were also reported to arrive between 09:00 and 09:30 local time. Maximum water level was only h ˜ 3 m in Laamu Atoll, which is interpreted by the wave amplitude damping by the coral reef to the east of the island complex as well as to that the tsunami did not arrived at high tide time. Damage was observed in several islands of Maldives but this was minimal as compared to the heavy destruction observed in Sri Lanka. About 25 Greek eyewitnesses, who happened to experience the tsunami attack in Padong and Blue Lagoon Port of Phuket island as well as in Maya Bay, Phi-Phi islands, Thailand, were interviewed on the basis of a standard questionnaire. The first sea motion was a retreat of at least 100 m. Then, two main waves arrived, the first being the strong one occurring at about 09:55-10:05 local time, with h ˜ 6m in Padong causing significant destruction and human victims. The collected information clearly indicates that the tsunami propagated as the leading crest wave to the west side, e.g. in Sri Lanka and Maldives, and as the leading trough wave to the east, e.g. in Thailand.

40 CFR 141.51 - Maximum contaminant level goals for inorganic contaminants.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...: Contaminant MCLG (mg/l) Antimony 0.006 Arsenic zero 1 Asbestos 7 Million fibers/liter (longer than 10 µm... Lead zero Mercury 0.002 Nitrate 10 (as Nitrogen). Nitrite 1 (as Nitrogen). Total Nitrate+Nitrite 10 (as...

40 CFR 141.51 - Maximum contaminant level goals for inorganic contaminants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...: Contaminant MCLG (mg/l) Antimony 0.006 Arsenic zero 1 Asbestos 7 Million fibers/liter (longer than 10 µm... Lead zero Mercury 0.002 Nitrate 10 (as Nitrogen). Nitrite 1 (as Nitrogen). Total Nitrate+Nitrite 10 (as...

40 CFR 141.51 - Maximum contaminant level goals for inorganic contaminants.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level...: Contaminant MCLG (mg/l) Antimony 0.006 Arsenic zero 1 Asbestos 7 Million fibers/liter (longer than 10 µm... Lead zero Mercury 0.002 Nitrate 10 (as Nitrogen). Nitrite 1 (as Nitrogen). Total Nitrate+Nitrite 10 (as...

On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

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

Dennis H. LeMieux

2004-10-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land -based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems; a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization.« less

The Effect of Uniform Background Flow on Vortex Ring Formation and Pinch-off

NASA Astrophysics Data System (ADS)

Krueger, Paul S.; Dabiri, John O.; Gharib, Morteza

2002-11-01

Experimental investigations of vortex ring formation are extended to include the effects of a uniform background flow, in a manner relevant to the locomotion of aquatic animals utilizing jet propulsion. Gharib et. al. [J. Fluid Mech. 360, 121 (1998)] generated vortex rings using a piston/cylinder apparatus with relatively large discharge times to demonstrate that the vortex ring at the leading edge of the jet attains its maximum circulation at a piston stroke-to-diameter ratio L/D of 4. This "formation number" is robust over a range of piston motions and cylinder boundary conditions, and can be explained in terms of the Kelvin-Benjamin variational principle. To determine the effect of background flow on formation number and pinch-off of the leading vortex ring, uniform co-flow is established in a large annulus surrounding the vortex generator. The ratio of co-flow velocity to piston velocity is varied between 0 and 1. In addition, the co-flow is initiated at times both before and after the start of vortex ring formation. We present results for stroke ratios L/D = 2 and L/D = 8, in order to discern effects of the co-flow on the leading vortex ring in isolation and in the presence of a trailing jet.

Lead distribution and its potential risk to the environment: lesson learned from environmental monitoring of abandon mine.

PubMed

Nobuntou, Wanida; Parkpian, Preeda; Oanh, Nguyen Thi Kim; Noomhorm, Athapol; Delaune, R D; Jugsujinda, Aroon

2010-11-01

There are many abandon and existing mines (tin, lead and zinc) in the mountainous areas of Thailand. Toxic elements including heavy metals such as lead (Pb), cadmium (Cd) and arsenic (As) have been released and transported from the mining sites to the adjacent landscape. In Thong Pha Phum District, Kanchanaburi Province, Thailand Pb contamination in the vicinity of the mine has occurred which could lead to potential health problems in downstream communities. To better understand current status of Pb contamination and accumulation in the surrounding environment and potential health impact, surface sediment, soil and plant samples were collected seasonally from representative monitoring sites along the aquatic track or flow regime. Potential health risk was determined using hazard quotient (HQ) as an index for local inhabitants who consume rice. Environmental monitoring illustrated that Pb concentrations in the surface sediment was as high as 869.4 mg kg(-1) dry weight and varied differently among stations sampled. Lead content in agricultural soil ranged between 137.8 to 613.5 mg kg(-1) dry weight and was inversely proportion to the distance from the point source. Moreover Pb was transported from the point source to down hill areas. At the highly polluted monitoring stations (S1, S2, and S3), concentrations of Pb exceeded the maximum allowable concentration for Pb in agricultural soil (300 mg kg(-1)) by 1.7-2 times. The Pb in soil was primarily associated with Fe/Mn oxides bound fraction (46-56%) followed by the organic bound fraction (25-30%). Lead uptake by plant varied and was species dependent. However root and tuber crops like cassava (19.92 mg Pb kg(-1) dry weight) and curcumin (3.25 mg Pb kg(-1) dry weight) could have removed Pb from the soil which suggest growing root crops in Pb contaminated soils should be avoided. However Cd, a co-contaminant at one of monitored stations (S4) yielded rice grain with Cd exceeding the maximum allowable concentration suggesting some potential health risk (HQ = 5.34) if people consume rice grown at this station. Overall result shows a low risk associated with Pb release into the environment.

P-Wave Indices and Risk of Ischemic Stroke: A Systematic Review and Meta-Analysis.

PubMed

He, Jinli; Tse, Gary; Korantzopoulos, Panagiotis; Letsas, Konstantinos P; Ali-Hasan-Al-Saegh, Sadeq; Kamel, Hooman; Li, Guangping; Lip, Gregory Y H; Liu, Tong

2017-08-01

Atrial cardiomyopathy is associated with an increased risk of ischemic stroke. P-wave terminal force in lead V 1 , P-wave duration, and maximum P-wave area are electrocardiographic parameters that have been used to assess left atrial abnormalities related to developing atrial fibrillation. The aim of this systematic review and meta-analysis was to examine their values for predicting ischemic stroke risk. PubMed and EMBASE databases were searched until December 2016 for studies that evaluated the association between P-wave indices and stroke risk. Both fixed- and random-effects models were used to calculate the overall effect estimates. Ten studies examining P-wave terminal force in lead V 1 , P-wave duration, and maximum P-wave area were included. P-wave terminal force in lead V 1 was found to be an independent predictor of stroke as both a continuous variable (odds ratio [OR] per 1 SD change, 1.18; 95% confidence interval [CI], 1.12-1.25; P <0.0001) and categorical variable (OR, 1.59; 95% CI, 1.10-2.28; P =0.01). P-wave duration was a significant predictor of incident ischemic stroke when analyzed as a categorical variable (OR, 1.86; 95% CI, 1.37-2.52; P <0.0001) but not when analyzed as a continuous variable (OR, 1.05; 95% CI, 0.98-1.13; P =0.15). Maximum P-wave area also predicted the risk of incident ischemic stroke (OR per 1 SD change, 1.10; 95% CI, 1.04-1.17). P-wave terminal force in lead V 1 , P-wave duration, and maximum P-wave area are useful electrocardiographic markers that can be used to stratify the risk of incident ischemic stroke. © 2017 American Heart Association, Inc.

Parameter optimisation for a better representation of drought by LSMs: inverse modelling vs. sequential data assimilation

NASA Astrophysics Data System (ADS)

Dewaele, Hélène; Munier, Simon; Albergel, Clément; Planque, Carole; Laanaia, Nabil; Carrer, Dominique; Calvet, Jean-Christophe

2017-09-01

Soil maximum available water content (MaxAWC) is a key parameter in land surface models (LSMs). However, being difficult to measure, this parameter is usually uncertain. This study assesses the feasibility of using a 15-year (1999-2013) time series of satellite-derived low-resolution observations of leaf area index (LAI) to estimate MaxAWC for rainfed croplands over France. LAI interannual variability is simulated using the CO2-responsive version of the Interactions between Soil, Biosphere and Atmosphere (ISBA) LSM for various values of MaxAWC. Optimal value is then selected by using (1) a simple inverse modelling technique, comparing simulated and observed LAI and (2) a more complex method consisting in integrating observed LAI in ISBA through a land data assimilation system (LDAS) and minimising LAI analysis increments. The evaluation of the MaxAWC estimates from both methods is done using simulated annual maximum above-ground biomass (Bag) and straw cereal grain yield (GY) values from the Agreste French agricultural statistics portal, for 45 administrative units presenting a high proportion of straw cereals. Significant correlations (p value < 0.01) between Bag and GY are found for up to 36 and 53 % of the administrative units for the inverse modelling and LDAS tuning methods, respectively. It is found that the LDAS tuning experiment gives more realistic values of MaxAWC and maximum Bag than the inverse modelling experiment. Using undisaggregated LAI observations leads to an underestimation of MaxAWC and maximum Bag in both experiments. Median annual maximum values of disaggregated LAI observations are found to correlate very well with MaxAWC.

Direct comparison of phase-sensitive vibrational sum frequency generation with maximum entropy method: case study of water.

PubMed

de Beer, Alex G F; Samson, Jean-Sebastièn; Hua, Wei; Huang, Zishuai; Chen, Xiangke; Allen, Heather C; Roke, Sylvie

2011-12-14

We present a direct comparison of phase sensitive sum-frequency generation experiments with phase reconstruction obtained by the maximum entropy method. We show that both methods lead to the same complex spectrum. Furthermore, we discuss the strengths and weaknesses of each of these methods, analyzing possible sources of experimental and analytical errors. A simulation program for maximum entropy phase reconstruction is available at: http://lbp.epfl.ch/. © 2011 American Institute of Physics

Design of single-winding energy-storage reactors for dc-to-dc converters using air-gapped magnetic-core structures

NASA Technical Reports Server (NTRS)

Ohri, A. K.; Wilson, T. G.; Owen, H. A., Jr.

1977-01-01

A procedure is presented for designing air-gapped energy-storage reactors for nine different dc-to-dc converters resulting from combinations of three single-winding power stages for voltage stepup, current stepup and voltage stepup/current stepup and three controllers with control laws that impose constant-frequency, constant transistor on-time and constant transistor off-time operation. The analysis, based on the energy-transfer requirement of the reactor, leads to a simple relationship for the required minimum volume of the air gap. Determination of this minimum air gap volume then permits the selection of either an air gap or a cross-sectional core area. Having picked one parameter, the minimum value of the other immediately leads to selection of the physical magnetic structure. Other analytically derived equations are used to obtain values for the required turns, the inductance, and the maximum rms winding current. The design procedure is applicable to a wide range of magnetic material characteristics and physical configurations for the air-gapped magnetic structure.

Improved thermoelectric power output from multilayered polyethylenimine doped carbon nanotube based organic composites

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

Hewitt, Corey A.; Montgomery, David S.; Barbalace, Ryan L.

2014-05-14

By appropriately selecting the carbon nanotube type and n-type dopant for the conduction layers in a multilayered carbon nanotube composite, the total device thermoelectric power output can be increased significantly. The particular materials chosen in this study were raw single walled carbon nanotubes for the p-type layers and polyethylenimine doped single walled carbon nanotubes for the n-type layers. The combination of these two conduction layers leads to a single thermocouple Seebeck coefficient of 96 ± 4 μVK{sup −1}, which is 6.3 times higher than that previously reported. This improved Seebeck coefficient leads to a total power output of 14.7 nW permore » thermocouple at the maximum temperature difference of 50 K, which is 44 times the power output per thermocouple for the previously reported results. Ultimately, these thermoelectric power output improvements help to increase the potential use of these lightweight, flexible, and durable organic multilayered carbon nanotube based thermoelectric modules in low powered electronics applications, where waste heat is available.« less

Accurate Drift Time Determination by Traveling Wave Ion Mobility Spectrometry: The Concept of the Diffusion Calibration.

PubMed

Kune, Christopher; Far, Johann; De Pauw, Edwin

2016-12-06

Ion mobility spectrometry (IMS) is a gas phase separation technique, which relies on differences in collision cross section (CCS) of ions. Ionic clouds of unresolved conformers overlap if the CCS difference is below the instrumental resolution expressed as CCS/ΔCCS. The experimental arrival time distribution (ATD) peak is then a superimposition of the various contributions weighted by their relative intensities. This paper introduces a strategy for accurate drift time determination using traveling wave ion mobility spectrometry (TWIMS) of poorly resolved or unresolved conformers. This method implements through a calibration procedure the link between the peak full width at half-maximum (fwhm) and the drift time of model compounds for wide range of settings for wave heights and velocities. We modified a Gaussian equation, which achieves the deconvolution of ATD peaks where the fwhm is fixed according to our calibration procedure. The new fitting Gaussian equation only depends on two parameters: The apex of the peak (A) and the mean drift time value (μ). The standard deviation parameter (correlated to fwhm) becomes a function of the drift time. This correlation function between μ and fwhm is obtained using the TWIMS calibration procedure which determines the maximum instrumental ion beam diffusion under limited and controlled space charge effect using ionic compounds which are detected as single conformers in the gas phase. This deconvolution process has been used to highlight the presence of poorly resolved conformers of crown ether complexes and peptides leading to more accurate CCS determinations in better agreement with quantum chemistry predictions.

Motion mitigation for lung cancer patients treated with active scanning proton therapy

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

Grassberger, Clemens, E-mail: Grassberger.Clemens@mgh.harvard.edu; Dowdell, Stephen; Sharp, Greg

2015-05-15

Purpose: Motion interplay can affect the tumor dose in scanned proton beam therapy. This study assesses the ability of rescanning and gating to mitigate interplay effects during lung treatments. Methods: The treatments of five lung cancer patients [48 Gy(RBE)/4fx] with varying tumor size (21.1–82.3 cm{sup 3}) and motion amplitude (2.9–30.6 mm) were simulated employing 4D Monte Carlo. The authors investigated two spot sizes (σ ∼ 12 and ∼3 mm), three rescanning techniques (layered, volumetric, breath-sampled volumetric) and respiratory gating with a 30% duty cycle. Results: For 4/5 patients, layered rescanning 6/2 times (for the small/large spot size) maintains equivalent uniformmore » dose within the target >98% for a single fraction. Breath sampling the timing of rescanning is ∼2 times more effective than the same number of continuous rescans. Volumetric rescanning is sensitive to synchronization effects, which was observed in 3/5 patients, though not for layered rescanning. For the large spot size, rescanning compared favorably with gating in terms of time requirements, i.e., 2x-rescanning is on average a factor ∼2.6 faster than gating for this scenario. For the small spot size however, 6x-rescanning takes on average 65% longer compared to gating. Rescanning has no effect on normal lung V{sub 20} and mean lung dose (MLD), though it reduces the maximum lung dose by on average 6.9 ± 2.4/16.7 ± 12.2 Gy(RBE) for the large and small spot sizes, respectively. Gating leads to a similar reduction in maximum dose and additionally reduces V{sub 20} and MLD. Breath-sampled rescanning is most successful in reducing the maximum dose to the normal lung. Conclusions: Both rescanning (2–6 times, depending on the beam size) as well as gating was able to mitigate interplay effects in the target for 4/5 patients studied. Layered rescanning is superior to volumetric rescanning, as the latter suffers from synchronization effects in 3/5 patients studied. Gating minimizes the irradiated volume of normal lung more efficiently, while breath-sampled rescanning is superior in reducing maximum doses to organs at risk.« less

Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

NASA Astrophysics Data System (ADS)

Hall, Alex; Taylor, Andy

2017-06-01

We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

Current Sheet Formation in a Conical Theta Pinch Faraday Accelerator with Radio-frequency Assisted Discharge

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Hallock, Ashley K.; Choueiri, Edgar Y.

2008-01-01

Data from an inductive conical theta pinch accelerator are presented to gain insight into the process of inductive current sheet formation in the presence of a preionized background gas produced by a steady-state RF-discharge. The presence of a preionized plasma has been previously shown to allow for current sheet formation at lower discharge voltages and energies than those found in other pulsed inductive accelerator concepts, leading to greater accelerator efficiencies at lower power levels. Time-resolved magnetic probe measurements are obtained for different background pressures and pulse energies to characterize the effects of these parameters on current sheet formation. Indices are defined that describe time-resolved current sheet characteristics, such as the total current owing in the current sheet, the time-integrated total current ('strength'), and current sheet velocity. It is found that for a given electric field strength, maximums in total current, strength, and velocity occur for one particular background pressure. At other pressures, these current sheet indices are considerably smaller. The trends observed in these indices are explained in terms of the principles behind Townsend breakdown that lead to a dependence on the ratio of the electric field to the background pressure. Time-integrated photographic data are also obtained at the same experimental conditions, and qualitatively they compare quite favorably with the time-resolved magnetic field data.

Development of an integrated hydrological modeling system for near-real-time multi-objective reservoir operation in large river basins

NASA Astrophysics Data System (ADS)

Wang, L.; Koike, T.

2010-12-01

The climate change-induced variability in hydrological cycles directly affects regional water resources management. For improved multiple multi-objective reservoir operation, an integrated modeling system has been developed by incorporating a global optimization system (SCE-UA) into a distributed biosphere hydrological model (WEB-DHM) coupled with the reservoir routing module. The reservoir storage change is estimated from the difference between the simulated inflows and outflows; while the reservoir water level can be defined from the updated reservoir storage by using the H-V curve. According to the reservoir water level, the new operation rule can be decided. For optimization: (1) WEB-DHM is calibrated for each dam’s inflows separately; (2) then the calibrated WEB-DHM is used to simulate inflows and outflows by assuming outflow proportional to inflow; and (3) the proportion coefficients are optimized with Shuffle Complex Evolution method (SCE-UA), to fulfill an objective function towards minimum flood risk at downstream and maximum reservoir water storage for future use. The GSMaP product offers hourly global precipitation maps in near real-time (about four hours after observation). Aiming at near real-time reservoir operation in large river basins, the integrated modeling system takes the inputs from both an operational global quantitative precipitation forecast (JMA-GPV; to achieve an optimal operation rule in the assumed lead time period) and the GSMaP product (to perform current operation with the obtained optimal rule, after correction by gauge rainfall). The newly-developed system was then applied to the Red River Basin, with an area of 160,000 km2, to test its performance for near real-time dam operation. In Vietnam, three reservoirs are located in the upstream of Hanoi city, with Hoa Binh the largest (69% of total volume). After calibration with the gauge rainfall, the inflows to three reservoirs are well simulated; the discharge and water level at Hanoi city are also well reproduced with the actual dam releases. With the corrected GSMaP rainfall (by using gauge rainfall), the inflows to reservoirs and the water level at Hanoi city can be also reasonably reproduced. The study aims at achieving an optimal operation rule in the lead time period (with the quantitative precipitation forecast) and then using it to perform current operation (with the corrected GSMaP rainfall). At Hanoi, there are relatively low flows in July, but high floods in August 2005. Results show that with the actual operation, dangerous water level in Hanoi was observed; while with the lead-time operation, the water level in Hanoi can be obviously cut down, and maximum water storage is also achieved for Hoa Binh reservoir at the end of flood season.

Colorado River sediment transport: 2. Systematic bed‐elevation and grain‐size effects of sand supply limitation

USGS Publications Warehouse

Topping, David J.; Rubin, David M.; Nelson, Jonathan M.; Kinzel, Paul J.; Corson, Ingrid C.

2000-01-01

The Colorado River in Marble and Grand Canyons displays evidence of annual supply limitation with respect to sand both prior to [Topping et al, this issue] and after the closure of Glen Canyon Dam in 1963. Systematic changes in bed elevation and systematic coupled changes in suspended‐sand concentration and grain size result from this supply limitation. During floods, sand supply limitation either causes or modifies a lag between the time of maximum discharge and the time of either maximum or minimum (depending on reach geometry) bed elevation. If, at a cross section where the bed aggrades with increasing flow, the maximum bed elevation is observed to lead the peak or the receding limb of a flood, then this observed response of the bed is due to sand supply limitation. Sand supply limitation also leads to the systematic evolution of sand grain size (both on the bed and in suspension) in the Colorado River. Sand input during a tributary flood travels down the Colorado River as an elongating sediment wave, with the finest sizes (because of their lower settling velocities) traveling the fastest. As the fine front of a sediment wave arrives at a given location, the bed fines and suspended‐sand concentrations increase in response to the enhanced upstream supply of finer sand. Then, as the front of the sediment wave passes that location, the bed is winnowed and suspended‐sand concentrations decrease in response to the depletion of the upstream supply of finer sand. The grain‐size effects of depletion of the upstream sand supply are most obvious during periods of higher dam releases (e.g., the 1996 flood experiment and the 1997 test flow). Because of substantial changes in the grain‐size distribution of the bed, stable relationships between the discharge of water and sand‐transport rates (i.e., stable sand rating curves) are precluded. Sand budgets in a supply‐limited river like the Colorado River can only be constructed through inclusion of the physical processes that couple changes in bed‐sediment grain size to changes in sand‐transport rates.

Impact of mixing state and hygroscopicity on CCN activity of biomass burning aerosol in Amazonia

NASA Astrophysics Data System (ADS)

Sánchez Gácita, Madeleine; Longo, Karla M.; Freire, Julliana L. M.; Freitas, Saulo R.; Martin, Scot T.

2017-02-01

Smoke aerosols prevail throughout Amazonia because of widespread biomass burning during the dry season, and external mixing, low variability in the particle size distribution and low particle hygroscopicity are typical. There can be profound effects on cloud properties. This study uses an adiabatic cloud model to simulate the activation of smoke particles as cloud condensation nuclei (CCN) for three hypothetical case studies, chosen as to resemble biomass burning aerosol observations in Amazonia. The relative importance of variability in hygroscopicity, mixing state, and activation kinetics for the activated fraction and maximum supersaturation is assessed. For a population with κp = 0.04, an overestimation of the cloud droplet number concentration Nd for the three selected case studies between 22.4 ± 1.4 and 54.3 ± 3.7 % was obtained when assuming a hygroscopicity parameter κp = 0.20. Assuming internal mixing of the aerosol population led to overestimations of up to 20 % of Nd when a group of particles with medium hygroscopicity was present in the externally mixed population cases. However, the overestimations were below 10 % for external mixtures between very low and low-hygroscopicity particles, as seems to be the case for Amazon smoke particles. Kinetic limitations were significant for medium- and high-hygroscopicity particles, and much lower for very low and low-hygroscopicity particles. When particles were assumed to be at equilibrium and to respond instantly to changes in the air parcel supersaturation, the overestimation of the droplet concentration was up to ˜ 100 % in internally mixed populations, and up to ˜ 250 % in externally mixed ones, being larger for the higher values of hygroscopicity. In addition, a perceptible delay between the times when maximum supersaturation and maximum aerosol activated fraction are reached was noticed and, for aerosol populations with effective hygroscopicity κpeff higher than a certain threshold value, the delay in particle activation was such that no particles were activated at the time of maximum supersaturation. Considering internally mixed populations, for an updraft velocity W = 0.5 m s-1 this threshold of no activation varied between κpeff = 0.35 and κpeff = 0.5 for the different case studies. However, for low hygroscopicity, kinetic limitations played a weaker role for CCN activation of particles, even when taking into account the large aerosol mass and number concentrations. For the very low range of hygroscopicities, the overestimation of the droplet concentration due to the equilibrium assumption was lowest and the delay between the times when maximum supersaturation and maximum activated fraction were reached was greatly reduced or no longer observed (depending on the case study). These findings on uncertainties and sensitivities provide guidance on appropriate simplifications that can be used for modeling of smoke aerosols within general circulation models. The use of medium values of hygroscopicity representative of smoke aerosols for other biomass burning regions on Earth can lead to significant errors compared to the use of low hygroscopicity for Amazonia (between 0.05 and 0.13, according to available observations). Also in this region, consideration of the biomass burning population as internally mixed will lead to small errors in the droplet concentration, while significantly increasing the computational burden. Regardless of the large smoke aerosol loads in the region during the dry season, kinetic limitations are expected to be low.

Lead concentration in meat from lead-killed moose and predicted human exposure using Monte Carlo simulation.

PubMed

Lindboe, M; Henrichsen, E N; Høgåsen, H R; Bernhoft, A

2012-01-01

Lead-based hunting ammunitions are still common in most countries. On impact such ammunition releases fragments which are widely distributed within the carcass. In Norway, wild game is an important meat source for segments of the population and 95% of hunters use lead-based bullets. In this paper, we have investigated the lead content of ground meat from moose (Alces alces) intended for human consumption in Norway, and have predicted human exposure through this source. Fifty-two samples from different batches of ground meat from moose killed with lead-based bullets were randomly collected. The lead content was measured by atomic absorption spectroscopy. The lead intake from exposure to moose meat over time, depending on the frequency of intake and portion size, was predicted using Monte Carlo simulation. In 81% of the batches, lead levels were above the limit of quantification of 0.03 mg kg(-1), ranging up to 110 mg kg(-1). The mean lead concentration was 5.6 mg kg(-1), i.e. 56 times the European Commission limit for lead in meat. For consumers eating a moderate meat serving (2 g kg(-1) bw), a single serving would give a lead intake of 11 µg kg(-1) bw on average, with maximum of 220 µg kg(-1) bw. Using Monte Carlo simulation, the median (and 97.5th percentile) predicted weekly intake of lead from moose meat was 12 µg kg(-1) bw (27 µg kg(-1) bw) for one serving per week and 25 µg kg(-1) bw (45 µg kg(-1) bw) for two servings per week. The results indicate that the intake of meat from big game shot with lead-based bullets imposes a significant contribution to the total human lead exposure. The provisional tolerable weekly intake set by the World Health Organization (WHO) of 25 µg kg(-1) bw is likely to be exceeded in people eating moose meat on a regular basis. The European Food Safety Authority (EFSA) has recently concluded that adverse effects may be present at even lower exposure doses. Hence, even occasional consumption of big game meat with lead levels as those found in the present study may imply an increased risk for adverse health effects. Children and women of child-bearing age are of special concern due to the neurodevelopmental effects of lead.

Poly(acrylic acid) modifying bentonite with in-situ polymerization for removing lead ions.

PubMed

He, Y F; Zhang, L; Yan, D Z; Liu, S L; Wang, H; Li, H R; Wang, R M

2012-01-01

In this paper, a new kind of poly(acrylic acid) modified clay adsorbent, the poly(acrylic acid)/bentonite composite (PAA/HB) was prepared by in-situ polymerization, and utilized to remove lead(II) ions from solutions. The maximum adsorption of adsorbent is at pH 5 for metal ions, whereas the adsorption starts at pH 2. The effects of contact time (5-60 min), initial concentration of metal ions (200-1,000 mg/L) and adsorbent dosage (0.04-0.12 g/100 mL) have been reported in this article. The experimental data were investigated by means of kinetic and equilibrium adsorption isotherms. The kinetic data were analyzed by the pseudo-first-order and pseudo-second-order equation. The experimental data fitted the pseudo-second-order kinetic model very well. Langmuir and Freundlich isotherms were tried for the system to better understand the adsorption isotherm process. The maximal adsorption capacity of the lead(II) ions on the PAA/HB, as calculated from the Langmuir model, was 769.2 mg/g. The results in this study indicated that PAA/HB was an attractive candidate for removing lead(II) (99%).

Environmental contamination in an Australian mining community and potential influences on early childhood health and behavioural outcomes.

PubMed

Dong, Chenyin; Taylor, Mark Patrick; Kristensen, Louise Jane; Zahran, Sammy

2015-12-01

Arsenic, cadmium and lead in aerosols, dusts and surface soils from Australia's oldest continuous lead mining town of Broken Hill were compared to standardised national childhood developmental (year 1) and education performance measures (years 3,5,7,9). Contaminants close to mining operations were elevated with maximum lead levels in soil: 8900 mg/kg; dust wipe: 86,061 μg/m(2); dust deposition: 2950 μg/m(2)/day; aerosols: 0.707 μg/m(3). The proportion of children from Broken Hill central, the area with the highest environmental contamination, presented with vulnerabilities in two or more developmental areas at 2.6 times the national average. Compared with other school catchments of Broken Hill, children in years 3 and 5 from the most contaminated school catchment returned consistently the lowest educational scores. By contrast, children living and attending schools associated with lower environmental contamination levels recorded higher school scores and lower developmental vulnerabilities. Similar results were identified in Australia's two other major lead mining and smelting cities of Port Pirie and Mount Isa. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of hydrodynamic simulations with two-shockwave drive target experiments

NASA Astrophysics Data System (ADS)

Karkhanis, Varad; Ramaprabhu, Praveen; Buttler, William

2015-11-01

We consider hydrodynamic continuum simulations to mimic ejecta generation in two-shockwave target experiments, where metallic surface is loaded by two successive shock waves. Time of second shock in simulations is determined to match experimental amplitudes at the arrival of the second shock. The negative Atwood number (A --> - 1) of ejecta simulations leads to two successive phase inversions of the interface corresponding to the passage of the shocks from heavy to light media in each instance. Metallic phase of ejecta (solid/liquid) depends on shock loading pressure in the experiment, and we find that hydrodynamic simulations quantify the liquid phase ejecta physics with a fair degree of accuracy, where RM instability is not suppressed by the strength effect. In particular, we find that our results of free surface velocity, maximum ejecta velocity, and maximum ejecta areal density are in excellent agreement with their experimental counterparts, as well as ejecta models. We also comment on the parametric space for hydrodynamic simulations in which they can be used to compare with the target experiments.

Maximum entropy production allows a simple representation of heterogeneity in semiarid ecosystems.

PubMed

Schymanski, Stanislaus J; Kleidon, Axel; Stieglitz, Marc; Narula, Jatin

2010-05-12

Feedbacks between water use, biomass and infiltration capacity in semiarid ecosystems have been shown to lead to the spontaneous formation of vegetation patterns in a simple model. The formation of patterns permits the maintenance of larger overall biomass at low rainfall rates compared with homogeneous vegetation. This results in a bias of models run at larger scales neglecting subgrid-scale variability. In the present study, we investigate the question whether subgrid-scale heterogeneity can be parameterized as the outcome of optimal partitioning between bare soil and vegetated area. We find that a two-box model reproduces the time-averaged biomass of the patterns emerging in a 100 x 100 grid model if the vegetated fraction is optimized for maximum entropy production (MEP). This suggests that the proposed optimality-based representation of subgrid-scale heterogeneity may be generally applicable to different systems and at different scales. The implications for our understanding of self-organized behaviour and its modelling are discussed.

Bayesian Approach to Spectral Function Reconstruction for Euclidean Quantum Field Theories

NASA Astrophysics Data System (ADS)

Burnier, Yannis; Rothkopf, Alexander

2013-11-01

We present a novel approach to the inference of spectral functions from Euclidean time correlator data that makes close contact with modern Bayesian concepts. Our method differs significantly from the maximum entropy method (MEM). A new set of axioms is postulated for the prior probability, leading to an improved expression, which is devoid of the asymptotically flat directions present in the Shanon-Jaynes entropy. Hyperparameters are integrated out explicitly, liberating us from the Gaussian approximations underlying the evidence approach of the maximum entropy method. We present a realistic test of our method in the context of the nonperturbative extraction of the heavy quark potential. Based on hard-thermal-loop correlator mock data, we establish firm requirements in the number of data points and their accuracy for a successful extraction of the potential from lattice QCD. Finally we reinvestigate quenched lattice QCD correlators from a previous study and provide an improved potential estimation at T=2.33TC.

Bayesian approach to spectral function reconstruction for Euclidean quantum field theories.

PubMed

Burnier, Yannis; Rothkopf, Alexander

2013-11-01

We present a novel approach to the inference of spectral functions from Euclidean time correlator data that makes close contact with modern Bayesian concepts. Our method differs significantly from the maximum entropy method (MEM). A new set of axioms is postulated for the prior probability, leading to an improved expression, which is devoid of the asymptotically flat directions present in the Shanon-Jaynes entropy. Hyperparameters are integrated out explicitly, liberating us from the Gaussian approximations underlying the evidence approach of the maximum entropy method. We present a realistic test of our method in the context of the nonperturbative extraction of the heavy quark potential. Based on hard-thermal-loop correlator mock data, we establish firm requirements in the number of data points and their accuracy for a successful extraction of the potential from lattice QCD. Finally we reinvestigate quenched lattice QCD correlators from a previous study and provide an improved potential estimation at T=2.33T(C).

Locomotive forces produced by single leukocytes in vivo and in vitro.

PubMed

Guilford, W H; Lantz, R C; Gore, R W

1995-05-01

We report here the first time-resolved measurements of the forces produced during the migration of single leukocytes in vivo and in vitro. Pulmonary macrophages from hamsters and mice, in vitro, and Nembutal (pentobarbital sodium)-anesthetized hamster neutrophils, in vivo, generated maximum locomotive forces ranging from 1.9 to 10.7 nN or tenths of microdynes. Force production was periodic and correlated with the length of the leading lamellipod but not with generalized cell ruffling. Although the extension of the leading lamella is critical to locomotive force generation, these direct measurements suggest that lamellar extension may not arise from the same contractile processes driving forward motion of the cell mass. Indeed, cell ruffling, lamellar extension, and locomotive force generation may be differentially controlled and have different origins. This technique may be extended to test numerous hypotheses of how these and other nonmuscle cells crawl.

Measurement of the temperature distribution inside the power cable using distributed temperature system

NASA Astrophysics Data System (ADS)

Jaros, Jakub; Liner, Andrej; Papes, Martin; Vasinek, Vladimir; Mach, Veleslav; Hruby, David; Kajnar, Tomas; Perecar, Frantisek

2015-01-01

Nowadays, the power cables are manufactured to fulfill the following condition - the highest allowable temperature of the cable during normal operation and the maximum allowable temperature at short circuit conditions cannot exceed the condition of the maximum allowable internal temperature. The distribution of the electric current through the conductor leads to the increase of the amplitude of electrons in the crystal lattice of the cables material. The consequence of this phenomenon is the increase of friction and the increase of collisions between particles inside the material, which causes the temperature increase of the carrying elements. The temperature increase is unwanted phenomena, because it is causing losses. In extreme cases, the long-term overload leads to the cable damaging or fire. This paper deals with the temperature distribution measurement inside the power cables using distributed temperature system. With cooperation with Kabex company, the tube containing optical fibers was installed into the center of power cables. These fibers, except telecommunications purposes, can be also used as sensors in measurements carrying out with distributed temperature system. These systems use the optical fiber as a sensor and allow the continual measurement of the temperature along the whole cable in real time with spatial resolution 1 m. DTS systems are successfully deployed in temperature measurement applications in industry areas yet. These areas include construction, drainage, hot water etc. Their advantages are low cost, resistance to electromagnetic radiation and the possibility of real time monitoring at the distance of 8 km. The location of the optical fiber in the center of the power cable allows the measurement of internal distribution of the temperature during overloading the cable. This measurement method can be also used for prediction of short-circuit and its exact location.

Factors in the intestinal absorption of oral cholecystopaques.

PubMed

Amberg, J R; Thompson, W M; Golberger, L; Williamson, S; Alexander, R; Bates, M

1980-01-01

Interest in the pharmacokinetics of cholecystopaques initially centered on transport from blood to bile. The data obtained in this effort have been valuable and have shown that the maximal iodine concentration achievable in the bile is quite similar for all of the currently available compounds. This concentration is, of course, dose dependent. the transport of contrast material from the bowel to the blood has been shown to be quite variable. Considerable progress was made in understanding this. The tremendous differences in absorption of iopanoic acid depending upon the pH of the administered solution was an initial revelation. The development of the concept that there is a water layer through which the cholecystopaque must pass before reaching the lipid membrane of the intestinal cell has added clarity to understanding the difference in absorption between water-soluble and water-insoluble cholecystopaques. A complete knowledge of what might enhance or inhibit absorption is not known. There is beginning to be an understanding of how intestinal dose relates to plasma levels. This should lead to an optimal dose-timing scheme for each cholecystopaque. The basic assumption is that the highest iodine concentration in the gallbladder leads to the most accurate cholecystography. If this is true, the gallbladder needs to be offered bile at the maximum concentrations during the period preceding filming. To accomplish this, the appropriate plasma level necessary for maximum excretion is needed. Experimental data suggest that our current clinical methods in regard to dose and dose timing need revision to optimize cholecystography. This revision needs to take place with a careful look at toxicity. Accepting the present premise that oral cholecystography can be improved, perhaps without a significant increase in morbidity, a fundamental question to be asked is: is it worth it?

Epitaxial growth of ordered and disordered granular sphere packings

NASA Astrophysics Data System (ADS)

Panaitescu, Andreea; Kudrolli, Arshad

2014-09-01

We demonstrate that epitaxy can be used to obtain a wide range of ordered to disordered granular packings by simply changing the deposition flux. We show that a defect-free face-centered-cubic (fcc) monocrystal can be obtained by depositing athermal granular spheres randomly into a container with a templated surface in a gravitational field without direct manipulation. This packing corresponds to the maximum sphere packing fraction and is obtained when the substrate is templated corresponding to the (100) plane of a fcc crystal and the container side is an integer multiple of the sphere diameter. We find that the maximum sphere packing is obtained when the deposited grains come to rest, one at a time, without damaging the substrate. A transition to a disordered packing is observed when the flux is increased. Using micro x-ray computed tomography, we find that defects nucleate at the boundaries of the container in which the packing is grown as grains cooperatively come to rest above their local potential minimum. This leads to a transition from ordered to disordered loose packings that grow in the form of an inverted cone, with the apex located at the defect nucleation site. We capture the observed decrease in order using a minimal model in which a defect leads to growth of further defects in the neighboring sites in the layer above with a probability that increases with the deposition flux.

Epitaxial growth of ordered and disordered granular sphere packings.

PubMed

Panaitescu, Andreea; Kudrolli, Arshad

2014-09-01

We demonstrate that epitaxy can be used to obtain a wide range of ordered to disordered granular packings by simply changing the deposition flux. We show that a defect-free face-centered-cubic (fcc) monocrystal can be obtained by depositing athermal granular spheres randomly into a container with a templated surface in a gravitational field without direct manipulation. This packing corresponds to the maximum sphere packing fraction and is obtained when the substrate is templated corresponding to the (100) plane of a fcc crystal and the container side is an integer multiple of the sphere diameter. We find that the maximum sphere packing is obtained when the deposited grains come to rest, one at a time, without damaging the substrate. A transition to a disordered packing is observed when the flux is increased. Using micro x-ray computed tomography, we find that defects nucleate at the boundaries of the container in which the packing is grown as grains cooperatively come to rest above their local potential minimum. This leads to a transition from ordered to disordered loose packings that grow in the form of an inverted cone, with the apex located at the defect nucleation site. We capture the observed decrease in order using a minimal model in which a defect leads to growth of further defects in the neighboring sites in the layer above with a probability that increases with the deposition flux.

Determination of carboxyhaemoglobin in humans following low-level exposures to carbon monoxide.

PubMed

Gosselin, Nathalie H; Brunet, Robert C; Carrier, Gaétan

2009-11-01

This study proposes to estimate carboxyhaemoglobin (COHb) levels in the blood of men and women of various ages exposed to common concentrations of carbon monoxide (CO) using a model with only one free parameter while integrating alveoli-blood and blood-tissue CO exchanges. The model retained is essentially that of Coburn et al. (1965) with two important additions: an alveoli compartment for the dynamics of CO exchanges between alveoli and blood, and a compartment for the significant amounts of CO bound to heme proteins in extravascular spaces. The model was validated by comparing its simulations with various published data sets for the COHb time profiles of volunteers exposed to known CO concentrations. Once the model was validated, it was used to simulate various situations of interest for their impact on public health. This approach yields reliable estimations of the time profiles of COHb levels resulting from different levels of CO exposure over various periods of time and under various conditions (resting, exercise, working, and smoking). The non-linear kinetics of CO, observed experimentally, were correctly reproduced by simulations with the model. Simulations were also carried out iteratively to determine the exposure times and CO concentrations in ambient air needed to reach the maximum levels of COHb recommended by Health Canada, the U.S. Environmental Protection Agency (EPA), and the World Health Organisation (WHO) for each age group of the general population. The lowest CO concentrations leading to maximum COHb levels of 1.5, 2, and 2.5% were determined.

Experimental design and modeling of ultrasound assisted simultaneous adsorption of cationic dyes onto ZnS: Mn-NPs-AC from binary mixture.

PubMed

Asfaram, Arash; Ghaedi, Mehrorang; Yousefi, Fakhri; Dastkhoon, Mehdi

2016-11-01

The manganese impregnated zinc sulfide nanoparticles deposited on activated carbon (ZnS: Mn-NPs-AC) which fully was synthesized and characterized successfully applied for simultaneous removal of malachite green and methylene blue in binary situation. The effects of variables such as pH (2.0-10.0), sonication time (1-5min), adsorbent mass (0.005-0.025g) and MB and MG concentration (4-20mgL(-1)) on their removal efficiency was studied dy central composite design (CCD) to correlate dyes removal percentage to above mention variables that guides amongst the maximum influence was seen by changing the sonication time and adsorbent mass. Sonication time, adsorbent mass and pH in despite of dyes concentrations has positive relation with removal percentage. Multiple regression analysis of the experimental results is associated with 3-D response surface and contour plots that guide setting condition at pH of 7.0, 3min sonication time, 0.025g Mn: ZnS-NPs-AC and 15mgL(-1) of MB and MG lead to achievement of removal efficiencies of 99.87% and 98.56% for MG and MB, respectively. The pseudo-second-order model as best choice efficiency describe the dyes adsorption behavior, while MG and MB maximum adsorption capacity according to Langmuir was 202.43 and 191.57mgg(-1). Copyright © 2016 Elsevier B.V. All rights reserved.

End-stage renal disease after occupational lead exposure: 20 years of follow-up.

PubMed

Evans, Marie; Discacciati, Andrea; Quershi, Abdul Rashid; Åkesson, Agneta; Elinder, Carl-Gustaf

2017-06-01

Whether low-level exposure to lead may give rise to chronic kidney disease or end-stage renal disease (ESRD) is debated. In this study, we aimed to specifically investigate if low-level occupational exposure to lead was associated with increased incidence of ESRD. The incidence of starting renal replacement therapy as a result of ESRD was examined in a cohort of10 303 lead-workers who had controlled blood lead concentrations due to a compulsory occupational health surveillance programme in Sweden during the time period 1977-1990. The ESRD incidence (obtained through register-linkage) among the lead-exposed workers was compared with the age, sex and calendar period-adjusted expected incidence based on data from the Swedish renal registry. Dose-response association was evaluated in external (general population) and internal (within the occupational cohort) comparisons by highest achieved blood lead level. There were 30 (0.29%) individuals in the cohort who developed ESRD during the median follow-up period of 26.3 years. The standardised incidence ratio (SIR) for ESRD incidence was 0.79 (95% CI 0.54 to 1.13). Among those who achieved the highest blood lead (>41.4 µg/dL), the SIR was 1.01 (0.44 to 1.99). There was no evidence of a dose-response relationship between the maximum achieved blood lead or the cumulative blood lead exposure and ESRD in external or internal comparisons. This study of workers with documented occupational lead exposures followed for 20 years shows no statistically significant association between lead exposure (following the current occupational recommendations for Sweden) and ESRD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Is Ammonification Rate in Marine Sediment Related to Plankton Composition and Abundance? A Time-series Study in Villefranche Bay (NW Mediterranean)

NASA Astrophysics Data System (ADS)

Fernex, François E.; Braconnot, Jean-Claude; Dallot, Serge; Boisson, Michel

1996-09-01

Observations were made near Cap Ferrat (Station B, about 80 m in water depth) France, in the water column and in the sediment, in order to evaluate to what extent variations in the ammonia and nitrate concentrations of the sediments are related to plankton population abundance and composition. Nitrate, nitrite, ammonia and chlorophyll awere measured several times during 1987 to 1989, at two depths (1 and 40 m). Copepods and salps in the upper 75 m of the water column were counted several times a week from 1987 to 1990. Ammonia and nitrate concentrations and ammonification rate were determined in the underlying sediments. During Spring 1987, phytoplankton biomass showed a maximum at the end of March; copepod populations increased regularly till the end of April, and salps increased from this time to the end of May. These populations were not so well developed during Spring 1988 and 1989. During the blooms, salp were mainly represented by Thalia democratica. The biomass of phytoplankton and zooplankton was low in summer. The sequence suggests that the copepod decline was related to reduced food levels after the phytoplankton decline. Salp population growth was not at the expense of phytoplankton and it can be assumed that the salp fed on other material. In 1987 and 1988, maximum organic nitrogen concentration in the bottom sediment and maximum ammonification rate directly followed the salp spring bloom. In 1987, the highest ammonification rate measured in the surficial sediment (0-2 cm) reached 0·05 μ M cm 3day -1(in June). In 1990, the rate exceeded 0·1 μM cm -3 day -1during an important salp bloom. Therefore, it seems that the sinking of salp fecal pellets plays an important part in the transfer of organic matter to the bottom, and microbial activity in the surficial sediment leads to mineralization of a great part of the organic nitrogen quickly after its deposition.

Isolation of a lead tolerant novel bacterial species, Achromobacter sp. TL-3: assessment of bioflocculant activity.

PubMed

Batta, Neha; Subudhi, Sanjukta; Lal, Banwari; Devi, Arundhuti

2013-11-01

Lead is one of the four heavy metals that has a profound damaging effects on human health. In the recent past there has been an increasing global concern for development of sustainable bioremediation technologies for detoxification of lead contaminant. Present investigation highlights for lead biosorption by a newly isolated novel bacterial species; Achromobacter sp. TL-3 strain, isolated from activated sludge samples contaminated with heavy metals (collected from oil refinery, Assam, North-East India). For isolation of lead tolerant bacteria, sludge samples were enriched into Luria Broth medium supplemented separately with a range of lead nitrate; 250, 500, 750, 1000, 1250 and 1500 ppm respectively. The bacterial consortium that could tolerate 1500 ppm of lead nitrate was selected further for purification of lead tolerant bacterial isolates. Purified lead tolerant bacterial isolates were then eventually inoculated into production medium supplemented with ethanol and glycerol as carbon and energy source to investigate for bioflocculant production. Bioflocculant production was estimated by monitoring the potential of lead tolerant bacterial isolate to flocculate Kaolin clay in presence of 1% CaCl2. Compared to other isolates, TL-3 isolate demonstrated for maximum bioflocculant activity of 95% and thus was identified based on 16S rRNA gene sequence analysis. TL3 isolate revealed maximum homology (98%) with Achromobacter sp. and thus designated as Achromobacter sp. TL-3. Bioflocculant activity of TL-3 isolate was correlated with the change in pH and growth. Achromobacter sp. TL-3 has significant potential for lead biosorption and can be effectively employed for detoxification of lead contaminated waste effluents/waste waters.

Studies on mathematical modeling of the leaching process in order to efficiently recover lead from the sulfate/oxide lead paste.

PubMed

Buzatu, Traian; Ghica, Gabriel Valeriu; Petrescu, Ionuţ Mircea; Iacob, Gheorghe; Buzatu, Mihai; Niculescu, Florentina

2017-02-01

Increasing global lead consumption has been mainly supported by the acid battery manufacturing industry. As the lead demand will continue to grow, to provide the necessary lead will require an efficient approach to recycling lead acid batteries. In this paper was performed a mathematical modeling of the process parameters for lead recovery from spent lead-acid batteries. The results of the mathematical modeling compare well with the experimental data. The experimental method applied consists in the solubilisation of the sulfate/oxide paste with sodium hydroxide solutions followed by electrolytic processing for lead recovery. The parameters taken into considerations were NaOH molarity (4M, 6M and 8M), solid/liquid ratio - S/L (1/10, 1/30 and 1/50) and temperature (40°C, 60°C and 80°C). The optimal conditions resulted by mathematical modeling of the electrolytic process of lead deposition from alkaline solutions have been established by using a second-order orthogonal program, in order to obtain a maximum efficiency of current without exceeding an imposed energy specific consumption. The optimum value for the leaching recovery efficiency, obtained through mathematical modeling, was 89.647%, with an error of δ y =3.623 which leads to a maximum recovery efficiency of 86.024%. The optimum values for each variable that ensure the lead extraction efficiency equal to 89.647% are the following: 3M - NaOH, 1/35 - S/L, 70°C - temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of dissolved oxygen on redox potential and milk acidification by lactic acid bacteria isolated from a DL-starter culture.

PubMed

Larsen, Nadja; Werner, Birgit Brøsted; Vogensen, Finn Kvist; Jespersen, Lene

2015-03-01

Milk acidification by DL-starter cultures [cultures containing Lactococcus lactis diacetylactis (D) and Leuconostoc (L) species] depends on the oxidation-reduction (redox) potential in milk; however, the mechanisms behind this effect are not completely clear. The objective of this study was to investigate the effect of dissolved oxygen on acidification kinetics and redox potential during milk fermentation by lactic acid bacteria (LAB). Fermentations were conducted by single strains isolated from mixed DL-starter culture, including Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Leuconostoc mesenteroides ssp. cremoris, by the DL-starter culture, and by the type strains. High and low levels of oxygen were produced by flushing milk with oxygen or nitrogen, respectively. The kinetics of milk acidification was characterized by the maximum rate and time of acidification (Vamax and Tamax), the maximum rate and time of reduction (Vrmax and Trmax), the minimum redox potential (Eh7 final), and time of reaching Eh7 final (Trfinal). Variations in kinetic parameters were observed at both the species and strain levels. Two of the Lc. lactis ssp. lactis strains were not able to lower redox potential to negative values. Kinetic parameters of the DL-starter culture were comparable with the best acidifying and reducing strains, indicating their additive effects. Acidification curves were mostly diauxic at all oxygen levels, displaying 2 maxima of acidification rate: before (aerobic maximum) and after (anaerobic maximum) oxygen depletion. The redox potential decreased concurrently with oxygen consumption and continued to decrease at slower rate until reaching the final values, indicating involvement of both oxygen and microbiological activity in the redox state of milk. Oxygen flushing had a negative effect on reduction and acidification capacity of tested LAB. Reduction was significantly delayed at high initial oxygen, exhibiting longer Trmax, Trfinal, or both. Concurrently, anaerobic acidification rate maximum Vamax was decreased and Tamax was extended. Fermentation kinetics in nitrogen-flushed milk was not statistically different from that in untreated milk except for Lc. lactis ssp. lactis CHCC D2, which showed faster reduction time after nitrogen flushing. This study clarifies the relationship between the redox state in milk and acidification kinetics of the predominant subspecies in DL-starter cultures. This knowledge is important for dairies to ensure optimized, fast, and controlled milk fermentations, leading to greater standardization of dairy products. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Functional Effects of Hyperthyroidism on Cardiac Papillary Muscle in Rats.

PubMed

Vieira, Fabricio Furtado; Olivoto, Robson Ruiz; Silva, Priscyla Oliveira da; Francisco, Julio Cesar; Fogaça, Rosalvo Tadeu Hochmuller

2016-12-01

Hyperthyroidism is currently recognized to affect the cardiovascular system, leading to a series of molecular and functional changes. However, little is known about the functional influence of hyperthyroidism in the regulation of cytoplasmic calcium and on the sodium/calcium exchanger (NCX) in the cardiac muscle. To evaluate the functional changes in papillary muscles isolated from animals with induced hyperthyroidism. We divided 36 Wistar rats into a group of controls and another of animals with hyperthyroidism induced by intraperitoneal T3 injection. We measured in the animals' papillary muscles the maximum contraction force, speed of contraction (+df/dt) and relaxation (-df/dt), contraction and relaxation time, contraction force at different concentrations of extracellular sodium, post-rest potentiation (PRP), and contraction force induced by caffeine. In hyperthyroid animals, we observed decreased PRP at all rest times (p < 0.05), increased +df/dt and -df/dt (p < 0.001), low positive inotropic response to decreased concentration of extracellular sodium (p < 0.001), reduction of the maximum force in caffeine-induced contraction (p < 0.003), and decreased total contraction time (p < 0.001). The maximal contraction force did not differ significantly between groups (p = 0.973). We hypothesize that the changes observed are likely due to a decrease in calcium content in the sarcoplasmic reticulum, caused by calcium leakage, decreased expression of NCX, and increased expression of a-MHC and SERCA2.

Optimum data analysis procedures for Titan 4 and Space Shuttle payload acoustic measurements during lift-off

NASA Technical Reports Server (NTRS)

Piersol, Allan G.

1991-01-01

Analytical expressions have been derived to describe the mean square error in the estimation of the maximum rms value computed from a step-wise (or running) time average of a nonstationary random signal. These analytical expressions have been applied to the problem of selecting the optimum averaging times that will minimize the total mean square errors in estimates of the maximum sound pressure levels measured inside the Titan IV payload fairing (PLF) and the Space Shuttle payload bay (PLB) during lift-off. Based on evaluations of typical Titan IV and Space Shuttle launch data, it has been determined that the optimum averaging times for computing the maximum levels are (1) T (sub o) = 1.14 sec for the maximum overall level, and T(sub oi) = 4.88 f (sub i) (exp -0.2) sec for the maximum 1/3 octave band levels inside the Titan IV PLF, and (2) T (sub o) = 1.65 sec for the maximum overall level, and T (sub oi) = 7.10 f (sub i) (exp -0.2) sec for the maximum 1/3 octave band levels inside the Space Shuttle PLB, where f (sub i) is the 1/3 octave band center frequency. However, the results for both vehicles indicate that the total rms error in the maximum level estimates will be within 25 percent the minimum error for all averaging times within plus or minus 50 percent of the optimum averaging time, so a precise selection of the exact optimum averaging time is not critical. Based on these results, linear averaging times (T) are recommended for computing the maximum sound pressure level during lift-off.

Bayesian view of single-qubit clocks, and an energy versus accuracy tradeoff

NASA Astrophysics Data System (ADS)

Gopalkrishnan, Manoj; Kandula, Varshith; Sriram, Praveen; Deshpande, Abhishek; Muralidharan, Bhaskaran

2017-09-01

We bring a Bayesian approach to the analysis of clocks. Using exponential distributions as priors for clocks, we analyze how well one can keep time with a single qubit freely precessing under a magnetic field. We find that, at least with a single qubit, quantum mechanics does not allow exact timekeeping, in contrast to classical mechanics, which does. We find the design of the single-qubit clock that leads to maximum accuracy. Further, we find an energy versus accuracy tradeoff—the energy cost is at least kBT times the improvement in accuracy as measured by the entropy reduction in going from the prior distribution to the posterior distribution. We propose a physical realization of the single-qubit clock using charge transport across a capacitively coupled quantum dot.

Structures and materials technology issues for reusable launch vehicles

NASA Technical Reports Server (NTRS)

Dixon, S. C.; Tenney, D. R.; Rummler, D. R.; Wieting, A. R.; Bader, R. M.

1985-01-01

Projected space missions for both civil and defense needs require significant improvements in structures and materials technology for reusable launch vehicles: reductions in structural weight compared to the Space Shuttle Orbiter of up to 25% or more, a possible factor of 5 or more increase in mission life, increases in maximum use temperature of the external surface, reusable containment of cryogenic hydrogen and oxygen, significant reductions in operational costs, and possibly less lead time between technology readiness and initial operational capability. In addition, there is increasing interest in hypersonic airbreathing propulsion for launch and transmospheric vehicles, and such systems require regeneratively cooled structure. The technology issues are addressed, giving brief assessments of the state-of-the-art and proposed activities to meet the technology requirements in a timely manner.

Novel target design for enhanced laser driven proton acceleration

NASA Astrophysics Data System (ADS)

Dalui, Malay; Kundu, M.; Tata, Sheroy; Lad, Amit D.; Jha, J.; Ray, Krishanu; Krishnamurthy, M.

2017-09-01

We demonstrate a simple method of preparing structured target for enhanced laser-driven proton acceleration under target-normal-sheath-acceleration scheme. A few layers of genetically modified, clinically grown micron sized E. Coli bacteria cell coated on a thin metal foil has resulted in an increase in the maximum proton energy by about 1.5 times and the total proton yield is enhanced by approximately 25 times compared to an unstructured reference foil at a laser intensity of 1019 W/cm2. Particle-in-cell simulations on the system shows that the structures on the target-foil facilitates anharmonic resonance, contributing to enhanced hot electron production which leads to stronger accelerating field. The effect is observed to grow as the number of structures is increased in the focal area of the laser pulse.

Time-dependent wellbore breakout growth caused by drilling-induced pore pressure transients: Implications for estimations of far field stress magnitude

NASA Astrophysics Data System (ADS)

Olcott, K. A.; Saffer, D. M.; Elsworth, D.

2013-12-01

One method used to constrain principal stress orientations and magnitudes in the crust combines estimates of rock strength with observations of wellbore failures, including drilling-induced tensile fractures (DITF) and compressional borehole breakouts (BO). This method has been applied at numerous Integrated Ocean Drilling Program (IODP) boreholes drilled into sediments in a wide range of settings, including the Gulf of Mexico, the N. Japan and Costa Rican subduction margins, and the Nankai Trough Accretionary Prism. At Nankai and N. Japan, BO widths defined by logging-while-drilling (LWD) resistivity images have been used to estimate magnitudes of far-field horizontal tectonic stresses. At several drillsites (C0010, C0002, and C0011), sections of the borehole were relogged with LWD after the hole was left open for times ranging from ~30 min to 3 days; times between acquisition were associated with pipe connections (~30 min), cleaning and circulating the hole (up to ~3 hr), and evacuation of the site for weather (~3 days). Relogged portions exhibit widening of BO, hypothesized to reflect time-dependent re-equilibration of instantaneous changes in pore fluid pressure (Pf) induced by opening the borehole. In this conceptual model, Pf decrease caused by initial excavation of the borehole and resulting changes in the state of stress at the borehole wall lead to an initial strengthening of the sediment. Re-equilibration of Pf results in time-dependent weakening of the sediment and subsequent BO growth. If correct, this hypothesis implies that stress magnitudes estimated by BO widths could be significantly underestimated. We test this idea using a finite-element model in COMSOL multiphysics that couples fluid flow and deformation in a poroelastic medium. We specify far-field horizontal principal stresses (SHmax and Shmin) in the model domain. At the start of simulations/at the time of borehole opening, we impose a decreased stress at the borehole wall. We consider a range of sediment permeability from 10-18 m2 to 10-14 m2. We find Pf initially increases at the borehole wall over a range of azimuths +/-~60° from Shmin, with a maximum increase of 10 MPa (4.4% of the maximum principal stress (σ1) at the borehole wall) and would lead to weakening of the rock. Pf decreases over a range of azimuths +/- ~30° from SHmax, with a maximum decrease of 10 MPa (8.8% of σ1), leading to initial strengthening of the rock. Evolution of Pf depends strongly on sediment permeability: Pf is 90% equilibrated at the borehole wall in ~43 minutes for a permeability of 10-18 m2, whereas for a permeability of 10-14 m2, Pf equilibrates nearly instantaneously. Since BO form parallel to Shmin, BO growth driven by drilling-induced Pf changes require that the initial BO be wider than ~120°, or outside the zone of initially increased Pf. This is not consistent with observations of BO growth, where initial BO are 0-25° and grow up to 125°. In contrast, our results imply that analyses based on BO measured immediately after drilling could overestimate far-field stresses because the BO are formed in sediments weakened by poroelastic pressure changes. Future work will focus on systematic investigation of the role of far field stresses and different sediment rheologies on the distribution of pore pressure change around the wellbore.

Influence of the sediment on lead speciation in the Tagus estuary.

PubMed

Mota, A M; Cruz, P; Vilhena, C; Gonçalves, M L S

2005-04-01

The aim of this work is to study the influence of the Tagus estuarine sediment on lead speciation in the overlying natural water. The water sample in the presence of the sediment was contaminated three times with Pb(II) in a laboratory experiment. In different periods of time, at 1-7 days after each contamination, small volumes of water were titrated with lead. The titration was followed by anodic stripping voltammetry in differential pulse mode. Before and after contamination systematic analysis of the voltammetric parameters (peak current, peak potential and peak width) were carried out to get a clear picture of Pb(II) complexation in the soluble fraction in contact with the sediment. Two main types of organic ligands, macromolecular ligands and small compounds, were detected before contamination. Both of them form labile complexes (degree of lability within the timescale of some milliseconds). The small compounds, with a diffusion coefficient similar to that of the free metal ion, present a homogeneous behaviour in terms of Pb complexation. On the other hand macromolecular ligands, with a diffusion coefficient of 1.2 x 10(-6) cm2s(-1), can be described by two different binding groups, which might be of phenolic and carboxylic type as presented by humic matter. The sediment eliminated lead contamination (10(-6) moldm(-3) was the maximum concentration added) from 12 dm3 of water (surface of 8 dm2) within 2 days. It was also found that the sediment released organic ligands responsible for both labile and inert Pb complexes "seen" by voltammetry. The release of organic ligands that decreases the bioavailability of Pb(II) was clearly detected 1 week after contamination. Therefore, the sediment acts as a buffer for lead through two mechanisms against lead contamination: removing lead ions from the solution and releasing organic ligands to the water column. In a short period of time the sediment responds as a self-cleaning system for Pb(II) contamination in the estuarine water, which may have a very important influence in environmental pollution.

A time-space domain stereo finite difference method for 3D scalar wave propagation

NASA Astrophysics Data System (ADS)

Chen, Yushu; Yang, Guangwen; Ma, Xiao; He, Conghui; Song, Guojie

2016-11-01

The time-space domain finite difference methods reduce numerical dispersion effectively by minimizing the error in the joint time-space domain. However, their interpolating coefficients are related with the Courant numbers, leading to significantly extra time costs for loading the coefficients consecutively according to velocity in heterogeneous models. In the present study, we develop a time-space domain stereo finite difference (TSSFD) method for 3D scalar wave equation. The method propagates both the displacements and their gradients simultaneously to keep more information of the wavefields, and minimizes the maximum phase velocity error directly using constant interpolation coefficients for different Courant numbers. We obtain the optimal constant coefficients by combining the truncated Taylor series approximation and the time-space domain optimization, and adjust the coefficients to improve the stability condition. Subsequent investigation shows that the TSSFD can suppress numerical dispersion effectively with high computational efficiency. The maximum phase velocity error of the TSSFD is just 3.09% even with only 2 sampling points per minimum wavelength when the Courant number is 0.4. Numerical experiments show that to generate wavefields with no visible numerical dispersion, the computational efficiency of the TSSFD is 576.9%, 193.5%, 699.0%, and 191.6% of those of the 4th-order and 8th-order Lax-Wendroff correction (LWC) method, the 4th-order staggered grid method (SG), and the 8th-order optimal finite difference method (OFD), respectively. Meanwhile, the TSSFD is compatible to the unsplit convolutional perfectly matched layer (CPML) boundary condition for absorbing artificial boundaries. The efficiency and capability to handle complex velocity models make it an attractive tool in imaging methods such as acoustic reverse time migration (RTM).

Lead poisoning from homemade wine: a case study.

PubMed Central

Mangas, S; Visvanathan, R; van Alphen, M

2001-01-01

A 66-year-old man suffered the symptoms of severe lead poisoning for 2 years before diagnosis. The man had a blood lead level (PbB) on admission to hospital of 98 microg/dL. A detailed investigation revealed that the poisoning occurred as a result of drinking a homemade red wine, for which analyses showed a lead concentration up to 14 mg/L--70 times the Australian maximum limit for lead in wine. The source of the lead was a highly corroded enamel bathtub in which grape crushings and juice were stored for a week prior to bottling. The corrosion of the enamel surface of the bathtub had resulted in pitted patches up to 1 mm in depth along the side of the bathtub. Powdering of the tub surface was evident below a level where wine had been in contact with the sides of the tub. The homemade wine had a pH of 3.8, which would have greatly contributed to the solubilization of metals from the glaze. We conducted a test in which commercial red wine of similar pH and containing < 0.2 mg/L lead was placed in this tub for 7 days. Subsequent testing revealed a lead level of 310 mg/L. This high lead concentration is consistent with the surface area of enamel on the bathtub being in contact with a small liquid volume as in the case of the leaching test using commercial red wine. This case study highlights the importance of the use of food-grade materials for the preparation and storage of homemade beverages or food. PMID:11335194

Lead poisoning from homemade wine: a case study.

PubMed

Mangas, S; Visvanathan, R; van Alphen, M

2001-04-01

A 66-year-old man suffered the symptoms of severe lead poisoning for 2 years before diagnosis. The man had a blood lead level (PbB) on admission to hospital of 98 microg/dL. A detailed investigation revealed that the poisoning occurred as a result of drinking a homemade red wine, for which analyses showed a lead concentration up to 14 mg/L--70 times the Australian maximum limit for lead in wine. The source of the lead was a highly corroded enamel bathtub in which grape crushings and juice were stored for a week prior to bottling. The corrosion of the enamel surface of the bathtub had resulted in pitted patches up to 1 mm in depth along the side of the bathtub. Powdering of the tub surface was evident below a level where wine had been in contact with the sides of the tub. The homemade wine had a pH of 3.8, which would have greatly contributed to the solubilization of metals from the glaze. We conducted a test in which commercial red wine of similar pH and containing < 0.2 mg/L lead was placed in this tub for 7 days. Subsequent testing revealed a lead level of 310 mg/L. This high lead concentration is consistent with the surface area of enamel on the bathtub being in contact with a small liquid volume as in the case of the leaching test using commercial red wine. This case study highlights the importance of the use of food-grade materials for the preparation and storage of homemade beverages or food.

Evaluating the atmospheric drivers leading to the December 2014 flood in Schleswig-Holstein, Germany

NASA Astrophysics Data System (ADS)

Schade, Nils H.

2017-06-01

Regional analyses of atmospheric conditions that may cause flooding of important transport infrastructure (railway tracks, highways/roads, rivers/channels) and subsequent adaptation measures are part of topic 1 of the network of experts initiated by the German Federal Ministry of Transport and Digital Infrastructure (BMVI). As an example case study, the December 2014 flood in Schleswig-Holstein, Germany, was investigated. Atmospheric conditions at the onset of the flood event are described and evaluated with respect to the general weather circulation, initial wetness, and event precipitation. Persistent, predominantly westerly general weather circulations (GWCs) directed several low-pressure systems over the North Sea to Schleswig-Holstein during December 2014, accompanied by prolonged rainfall and finally a strong precipitation event in southern Schleswig-Holstein, causing several inland gauges to exceed their, by then maximum, water levels. Results show that the antecedent precipitation index (API) is able to reflect the soil moisture conditions and, in combination with the maximum 3-day precipitation sum (R3d), to capture the two main drivers finally leading to the flood: (1) the initial wetness of north-western Schleswig-Holstein and (2) strong event precipitation in southern and eastern Schleswig-Holstein from 21 to 23 December; at the same time, both indices exceeded their respective 5-year return periods. Further, trend analyses show that both API and R3d have been increasing during recent years, while regional patterns match the north-eastward shift of cyclone pathways, leading to a higher risk of flooding in Schleswig-Holstein. Within the network of experts, investigations of these and further indices/drivers for earth system changes (e.g. wind surge and sea level rise) derived from observations, reanalyses, and regional climate model data are planned for all German coastal areas. Results can be expected to lead to improved adaptation measures to floods under climate change conditions wherever catchments have to be drained and infrastructures and ecosystems may be harmed.

Batch sorption dynamics and equilibrium for the removal of lead ions from aqueous phase using activated carbon developed from coffee residue activated with zinc chloride.

PubMed

Boudrahem, F; Aissani-Benissad, F; Aït-Amar, H

2009-07-01

Lignocellulosic materials are good precursors for the production of activated carbon. In this work, coffee residue has been used as raw material in the preparation of powder activated carbon by the method of chemical activation with zinc chloride for the sorption of Pb(II) from dilute aqueous solutions. The influence of impregnation ratio (ZnCl2/coffee residue) on the physical and chemical properties of the prepared carbons was studied in order to optimize this parameter. The optimum experimental condition for preparing predominantly microporous activated carbons with high pore surface area (890 m2/g) and micropore volume (0.772 cm3/g) is an impregnation ratio of 100%. The developed activated carbon shows substantial capability to sorb lead(II) ions from aqueous solutions and for relative impregnation ratios of 75 and 100%, the maximum uptake is practically the same. Thus, 75% represents the optimal impregnation ratio. Batch experiments were conducted to study the effects of the main parameters such as contact time, initial concentration of Pb(II), solution pH, ionic strength and temperature. The maximum uptake of lead(II) at 25 degrees C was about 63 mg/g of adsorbent at pH 5.8, initial Pb(II) concentration of 10 mg/L, agitation speed of 200 rpm and ionic strength of 0.005 M. The kinetic data were fitted to the models of pseudo-first order and pseudo-second order, and follow closely the pseudo-second order model. Equilibrium sorption isotherms of Pb(II) were analyzed by the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model gives a better fit than the others. Results from this study suggest that activated carbon produced from coffee residue is an effective adsorbent for the removal of lead from aqueous solutions and that ZnCl2 is a suitable activating agent for the preparation of high-porosity carbons.

49 CFR 398.6 - Hours of service of drivers; maximum driving time.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Hours of service of drivers; maximum driving time... REGULATIONS TRANSPORTATION OF MIGRANT WORKERS § 398.6 Hours of service of drivers; maximum driving time. No... or operate for more than 10 hours in the aggregate (excluding rest stops and stops for meals) in any...

49 CFR 398.6 - Hours of service of drivers; maximum driving time.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Hours of service of drivers; maximum driving time... REGULATIONS TRANSPORTATION OF MIGRANT WORKERS § 398.6 Hours of service of drivers; maximum driving time. No... or operate for more than 10 hours in the aggregate (excluding rest stops and stops for meals) in any...

Maximum thrust mode evaluation

NASA Technical Reports Server (NTRS)

Orme, John S.; Nobbs, Steven G.

1995-01-01

Measured reductions in acceleration times which resulted from the application of the F-15 performance seeking control (PSC) maximum thrust mode during the dual-engine test phase is presented as a function of power setting and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and maximum afterburning power settings. The time savings for the supersonic acceleration is less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Recall that even though the engine is at maximum afterburner, PSC does not trim the afterburner for the maximum thrust mode. Subsonically at military power, time to accelerate from Mach 0.6 to 0.95 was cut by between 6 and 8 percent with a single engine application of PSC, and over 14 percent when both engines were optimized. At maximum afterburner, the level of thrust increases were similar in magnitude to the military power results, but because of higher thrust levels at maximum afterburner and higher aircraft drag at supersonic Mach numbers the percentage thrust increase and time to accelerate was less than for the supersonic accelerations. Savings in time to accelerate supersonically at maximum afterburner ranged from 4 to 7 percent. In general, the maximum thrust mode has performed well, demonstrating significant thrust increases at military and maximum afterburner power. Increases of up to 15 percent at typical combat-type flight conditions were identified. Thrust increases of this magnitude could be useful in a combat situation.

Detection Times of Diazepam, Clonazepam, and Alprazolam in Oral Fluid Collected From Patients Admitted to Detoxification, After High and Repeated Drug Intake.

PubMed

Nordal, Kristin; Øiestad, Elisabeth L; Enger, Asle; Christophersen, Asbjorg S; Vindenes, Vigdis

2015-08-01

Clonazepam, diazepam, and alprazolam are benzodiazepines with sedative, anticonvulsant, and anxiolytic effects, but their prevalence in drug abuse and drug overdoses has long been recognized. When detection times for psychoactive drugs in oral fluid are reported, they are most often based on therapeutic doses administered in clinical studies. Repeated ingestions of high doses, as seen after drug abuse, are however likely to cause positive samples for extended time periods. Findings of drugs of abuse in oral fluid collected from imprisoned persons might lead to negative sanctions, and the knowledge of detection times of these drugs is thus important to ensure correct interpretation. The aim of this study was to investigate the time window of detection for diazepam, clonazepam, and alprazolam in oral fluid from drug addicts admitted to detoxification. Twenty-five patients with a history of heavy drug abuse admitted to a detoxification ward were included. Oral fluid was collected daily in the morning and the evening and urine samples every morning for 10 days, using the Intercept device. Whole blood samples were collected if the patient accepted. The cutoff levels in oral fluid were 1.3 ng/mL for diazepam, N-desmethyldiazepam, and 7-aminoclonazepam and 1 ng/mL for clonazepam and alprazolam. In urine, the cutoff levels for quantifications were 30 ng/mL for alprazolam, alpha-OH-alprazolam, and 7-aminoclonazepam, 135 ng/mL for N-desmethyldizepam, and 150 ng/mL for 3-OH-diazepam and for all the compounds, the cutoff for the screening analyses were 200 ng/mL. The maximum detection times for diazepam and N-desmethyldiazepam in oral fluid were 7 and 9 days, respectively. For clonazepam and 7-aminoclonazepam, the maximum detection times in oral fluid were 5 and 6 days, respectively. The maximum detection time for alprazolam in oral fluid was 2.5 days. New ingestions were not suspected in any of the cases, because the corresponding concentrations in urine were decreasing. Results from blood samples revealed that high doses of benzodiazepines had been ingested before admission, and explains the longer detection times in oral fluids than reported previously after intake of therapeutic doses of these drugs. This study has shown that oral fluid might be a viable alternative medium to urine when the abuse of benzodiazepines is suspected.

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

Wave Transformation over a Fringing Coral Reef and the Importance of Low-Frequency Waves and Offshore Water Levels to Runup and Island Overtopping

NASA Astrophysics Data System (ADS)

Cheriton, O. M.; Storlazzi, C. D.; Rosenberger, K. J.

2016-02-01

Low-lying, reef-fringed islands are susceptible to sea-level rise and often subjected to overwash and flooding during large wave events. To quantify wave dynamics and wave-driven water levels on fringing coral reefs, wave gauges and a current meter were deployed for 5 months across two shore-normal transects on Roi-Namur, an atoll island in the Republic of the Marshall Islands. These observations captured two large wave events that had maximum wave heights greater than 6 m and peak periods of 16 s over the fore reef. The larger event coincided with a peak spring tide, leading to energetic, highly-skewed infragravity (0.04-0.004 Hz) and very low frequency (0.004-0.001 Hz) waves at the shoreline, which reached heights of 1.0 and 0.7 m, respectively. Water surface elevations, combined with wave runup, exceeded 3.7 m at the innermost reef flat adjacent to the toe of the beach, resulting in flooding of inland areas. This overwash occurred during a 3-hr time window that coincided with high tide and maximum low-frequency reef flat wave heights. The relatively low-relief characteristics of this narrow reef flat may further drive shoreline amplification of low-frequency waves due to resonance modes. These results demonstrate how the coupling of high offshore water levels with low-frequency reef flat wave energetics can lead to large impacts along atoll and fringing reef-lined shorelines, such as island overwash. These observations lend support to the hypothesis that predicted higher sea levels will lead to more frequent occurrences of both extreme shoreline runup and island overwash, threatening the sustainability of these islands.

Observations of wave transformation over a fringing coral reef and the importance of low-frequency waves and offshore water levels to runup, overwash, and coastal flooding

NASA Astrophysics Data System (ADS)

Cheriton, Olivia M.; Storlazzi, Curt D.; Rosenberger, Kurt J.

2016-05-01

Many low-lying tropical islands are susceptible to sea level rise and often subjected to overwash and flooding during large wave events. To quantify wave dynamics and wave-driven water levels on fringing coral reefs, a 5 month deployment of wave gauges and a current meter was conducted across two shore-normal transects on Roi-Namur Island in the Republic of the Marshall Islands. These observations captured two large wave events that had waves with maximum heights greater than 6 m with peak periods of 16 s over the fore reef. The larger event coincided with a peak spring tide, leading to energetic, highly skewed infragravity (0.04-0.004 Hz) and very low frequency (0.004-0.001 Hz) waves at the shoreline, which reached heights of 1.0 and 0.7 m, respectively. Water surface elevations, combined with wave runup, reached 3.7 m above the reef bed at the innermost reef flat adjacent to the toe of the beach, resulting in flooding of inland areas. This overwash occurred during a 3 h time window that coincided with high tide and maximum low-frequency reef flat wave heights. The relatively low-relief characteristics of this narrow reef flat may further drive shoreline amplification of low-frequency waves due to resonance modes. These results (1) demonstrate how the coupling of high offshore water levels with low-frequency reef flat wave energetics can lead to large impacts along fringing reef-lined shorelines, such as island overwash, and (2) lend support to the hypothesis that predicted higher sea levels will lead to more frequent occurrences of these extreme events, negatively impacting coastal resources and infrastructure.

Observations of wave transformation over a fringing coral reef and the importance of low-frequency waves and offshore water levels to runup, overwash, and coastal flooding

USGS Publications Warehouse

Cheriton, Olivia; Storlazzi, Curt; Rosenberger, Kurt

2016-01-01

Many low-lying tropical islands are susceptible to sea level rise and often subjected to overwash and flooding during large wave events. To quantify wave dynamics and wave-driven water levels on fringing coral reefs, a 5 month deployment of wave gauges and a current meter was conducted across two shore-normal transects on Roi-Namur Island in the Republic of the Marshall Islands. These observations captured two large wave events that had waves with maximum heights greater than 6 m with peak periods of 16 s over the fore reef. The larger event coincided with a peak spring tide, leading to energetic, highly skewed infragravity (0.04–0.004 Hz) and very low frequency (0.004–0.001 Hz) waves at the shoreline, which reached heights of 1.0 and 0.7 m, respectively. Water surface elevations, combined with wave runup, reached 3.7 m above the reef bed at the innermost reef flat adjacent to the toe of the beach, resulting in flooding of inland areas. This overwash occurred during a 3 h time window that coincided with high tide and maximum low-frequency reef flat wave heights. The relatively low-relief characteristics of this narrow reef flat may further drive shoreline amplification of low-frequency waves due to resonance modes. These results (1) demonstrate how the coupling of high offshore water levels with low-frequency reef flat wave energetics can lead to large impacts along fringing reef-lined shorelines, such as island overwash, and (2) lend support to the hypothesis that predicted higher sea levels will lead to more frequent occurrences of these extreme events, negatively impacting coastal resources and infrastructure.

Wide range scaling laws for radiation driven shock speed, wall albedo and ablation parameters for high-Z materials

NASA Astrophysics Data System (ADS)

Mishra, Gaurav; Ghosh, Karabi; Ray, Aditi; Gupta, N. K.

2018-06-01

Radiation hydrodynamic (RHD) simulations for four different potential high-Z hohlraum materials, namely Tungsten (W), Gold (Au), Lead (Pb), and Uranium (U) are performed in order to investigate their performance with respect to x-ray absorption, re-emission and ablation properties, when irradiated by constant temperature drives. A universal functional form is derived for estimating time dependent wall albedo for high-Z materials. Among the high-Z materials studied, it is observed that for a fixed simulation time the albedo is maximum for Au below 250 eV, whereas it is maximum for U above 250 eV. New scaling laws for shock speed vs drive temperature, applicable over a wide temperature range of 100 eV to 500 eV, are proposed based on the physics of x-ray driven stationary ablation. The resulting scaling relation for a reference material Aluminium (Al), shows good agreement with that of Kauffman's power law for temperatures ranging from 100 eV to 275 eV. New scaling relations are also obtained for temperature dependent mass ablation rate and ablation pressure, through RHD simulation. Finally, our study reveals that for temperatures above 250 eV, U serves as a better hohlraum material since it offers maximum re-emission for x-rays along with comparable mass ablation rate. Nevertheless, traditional choice, Au works well for temperatures below 250 eV. Besides inertial confinement fusion (ICF), the new scaling relations may find its application in view-factor codes, which generally ignore atomic physics calculations of opacities and emissivities, details of laser-plasma interaction and hydrodynamic motions.

Short-term Recovery Following Resistance Exercise Leading or not to Failure.

PubMed

González-Badillo, J J; Rodríguez-Rosell, D; Sánchez-Medina, L; Ribas, J; López-López, C; Mora-Custodio, R; Yañez-García, J M; Pareja-Blanco, F

2016-04-01

This study analyzed the time course of recovery following 2 resistance exercise protocols differing in level of effort: maximum (to failure) vs. half-maximum number of repetitions per set. 9 males performed 3 sets of 4 vs. 8 repetitions with their 80% 1RM load, 3×4(8) vs. 3×8(8), in the bench press and squat. Several time-points from 24 h pre- to 48 h post-exercise were established to assess the mechanical (countermovement jump height, CMJ; velocity against the 1 m·s(-1) load, V1-load), biochemical (testosterone, cortisol, GH, prolactin, IGF-1, CK) and heart rate variability (HRV) and complexity (HRC) response to exercise. 3×8(8) resulted in greater neuromuscular fatigue (higher reductions in repetition velocity and velocity against V1-load) than 3×4(8). CMJ remained reduced up to 48 h post-exercise following 3×8(8), whereas it was recovered after 6 h for 3×4(8). Significantly greater prolactin and IGF-1 levels were found for 3×8(8) vs. 3×4(8). Significant reductions in HRV and HRC were observed for 3×8(8) vs. 3×4(8) in the immediate recovery. Performing a half-maximum number of repetitions per set resulted in: 1) a stimulus of faster mean repetition velocities; 2) lower impairment of neuromuscular performance and faster recovery; 3) reduced hormonal response and muscle damage; and 4) lower reduction in HRV and HRC following exercise. © Georg Thieme Verlag KG Stuttgart · New York.

Superfast maximum-likelihood reconstruction for quantum tomography

NASA Astrophysics Data System (ADS)

Shang, Jiangwei; Zhang, Zhengyun; Ng, Hui Khoon

2017-06-01

Conventional methods for computing maximum-likelihood estimators (MLE) often converge slowly in practical situations, leading to a search for simplifying methods that rely on additional assumptions for their validity. In this work, we provide a fast and reliable algorithm for maximum-likelihood reconstruction that avoids this slow convergence. Our method utilizes the state-of-the-art convex optimization scheme, an accelerated projected-gradient method, that allows one to accommodate the quantum nature of the problem in a different way than in the standard methods. We demonstrate the power of our approach by comparing its performance with other algorithms for n -qubit state tomography. In particular, an eight-qubit situation that purportedly took weeks of computation time in 2005 can now be completed in under a minute for a single set of data, with far higher accuracy than previously possible. This refutes the common claim that MLE reconstruction is slow and reduces the need for alternative methods that often come with difficult-to-verify assumptions. In fact, recent methods assuming Gaussian statistics or relying on compressed sensing ideas are demonstrably inapplicable for the situation under consideration here. Our algorithm can be applied to general optimization problems over the quantum state space; the philosophy of projected gradients can further be utilized for optimization contexts with general constraints.

40 CFR 471.101 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... emulsion. Subpart J—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average... process wastewater pollutants. (g) Sawing or grinding spent emulsion. Subpart J—BPT Pollutant or pollutant... powder metallurgy parts sawed or ground with emulsion Copper 0.035 0.018 Cyanide 0.005 0.002 Lead 0.008 0...

40 CFR 471.101 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... emulsion. Subpart J—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average... process wastewater pollutants. (g) Sawing or grinding spent emulsion. Subpart J—BPT Pollutant or pollutant... powder metallurgy parts sawed or ground with emulsion Copper 0.035 0.018 Cyanide 0.005 0.002 Lead 0.008 0...

40 CFR 471.101 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... emulsion. Subpart J—BPT Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average... process wastewater pollutants. (g) Sawing or grinding spent emulsion. Subpart J—BPT Pollutant or pollutant... powder metallurgy parts sawed or ground with emulsion Copper 0.035 0.018 Cyanide 0.005 0.002 Lead 0.008 0...

Risk of Sprint Fidelis defibrillator lead failure is highly dependent on age.

PubMed

Girerd, Nicolas; Nonin, Emilie; Pinot, Julien; Morel, Elodie; Flys, Carine; Scridon, Alina; Chevalier, Philippe

2011-01-01

In 2007, Medtronic Sprint Fidelis defibrillator leads were taken off the market due to a high rate of lead failure. Current data do not allow for risk stratification of patients with regard to lead failure. We sought to determine predictors of Sprint Fidelis lead failure. Between 2004 and 2007, 269 Sprint Fidelis leads were implanted in 258 patients in our centre. Variables associated with lead failure were assessed by the Kaplan-Meier method and a Cox survival model. During a median follow-up of 2.80 years (maximum 5.32), we observed 33 (12.3%) Sprint Fidelis lead failures (5-year survival, 65.6% ± 7.5%). In univariate analysis, age was the only predictor of lead failure (hazard ratio [HR] for 1-year increase 0.97; 95% confidence interval [CI] 0.95-0.99; p=0.009). Patients aged<62.5 years (median) had a significantly increased risk of lead failure compared with patients aged>62.5 years (HR 2.80; CI 1.30-6.02; p=0.009). Survival without Sprint Fidelis lead failure was 55.6% ± 10.4%) in patients aged<62.5 years (24/134 leads) vs 78.6% ± 8.8% in patients aged>62.5 years (9/135 leads). The annual incidence of lead failure in patients aged<62.5 years was 11.6% ± 4.9% during the fourth year after implantation and 22.9% ± 13.2% during the fifth year. Overall, we found a higher rate of Sprint Fidelis lead dysfunction than previously described. Lead failure was much more frequent in younger patients. Our results emphasize the need for close follow-up of younger patients with Sprint Fidelis leads and suggest that, in these patients, the implantation of a new implantable cardioverter defibrillator lead at the time of generator replacement might be reasonable. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Pediatric lead exposure from imported Indian spices and cultural powders.

PubMed

Lin, Cristiane Gurgel; Schaider, Laurel Anne; Brabander, Daniel Joseph; Woolf, Alan David

2010-04-01

Significant lead poisoning has been associated with imported nonpaint products. To describe cases of pediatric lead intoxication from imported Indian spices and cultural powders, determine lead concentrations in these products, and predict effects of ingestion on pediatric blood lead levels (BLLs). Cases and case-study information were obtained from patients followed by the Pediatric Environmental Health Center (Children's Hospital Boston). Imported spices (n = 86) and cultural powders (n = 71) were analyzed for lead by using x-ray fluorescence spectroscopy. The simple bioaccessibility extraction test was used to estimate oral bioavailability. The integrated exposure uptake biokinetic model for lead in children was used to predict population-wide geometric mean BLLs and the probability of elevated BLLs (>10 microg/dL). Four cases of pediatric lead poisoning from Indian spices or cultural powders are described. Twenty-two of 86 spices and foodstuff products contained >1 microg/g lead (for these 22 samples, mean: 2.6 microg/g [95% confidence interval: 1.9-3.3]; maximum: 7.6 microg/g). Forty-six of 71 cultural products contained >1 microg/g lead (for 43 of these samples, mean: 8.0 microg/g [95% confidence interval: 5.2-10.8]; maximum: 41.4 microg/g). Three sindoor products contained >47% lead. With a fixed ingestion of 5 microg/day and 50% bioavailability, predicted geometric mean BLLs for children aged 0 to 4 years increased from 3.2 to 4.1 microg/dL, and predicted prevalence of children with a BLL of >10 microg/dL increased more than threefold (0.8%-2.8%). Chronic exposure to spices and cultural powders may cause elevated BLLs. A majority of cultural products contained >1 microg/g lead, and some sindoor contained extremely high bioaccessible lead levels. Clinicians should routinely screen for exposure to these products.

The maximum intelligible range of the human voice

NASA Astrophysics Data System (ADS)

Boren, Braxton

This dissertation examines the acoustics of the spoken voice at high levels and the maximum number of people that could hear such a voice unamplified in the open air. In particular, it examines an early auditory experiment by Benjamin Franklin which sought to determine the maximum intelligible crowd for the Anglican preacher George Whitefield in the eighteenth century. Using Franklin's description of the experiment and a noise source on Front Street, the geometry and diffraction effects of such a noise source are examined to more precisely pinpoint Franklin's position when Whitefield's voice ceased to be intelligible. Based on historical maps, drawings, and prints, the geometry and material of Market Street is constructed as a computer model which is then used to construct an acoustic cone tracing model. Based on minimal values of the Speech Transmission Index (STI) at Franklin's position, Whitefield's on-axis Sound Pressure Level (SPL) at 1 m is determined, leading to estimates centering around 90 dBA. Recordings are carried out on trained actors and singers to determine their maximum time-averaged SPL at 1 m. This suggests that the greatest average SPL achievable by the human voice is 90-91 dBA, similar to the median estimates for Whitefield's voice. The sites of Whitefield's largest crowds are acoustically modeled based on historical evidence and maps. Based on Whitefield's SPL, the minimal STI value, and the crowd's background noise, this allows a prediction of the minimally intelligible area for each site. These yield maximum crowd estimates of 50,000 under ideal conditions, while crowds of 20,000 to 30,000 seem more reasonable when the crowd was reasonably quiet and Whitefield's voice was near 90 dBA.

Assessing the Skill of Chlorophyll Forecasts: Latest Development and Challenges Ahead Using the Case of the Equatorial Pacific

NASA Technical Reports Server (NTRS)

Rousseaux, Cecile S.; Gregg, Watson W.

2018-01-01

Using a global ocean biogeochemical model combined with a forecast of physical oceanic and atmospheric variables from the NASA Global Modeling and Assimilation Office, we assess the skill of a chlorophyll concentrations forecast in the Equatorial Pacific for the period 2012-2015 with a focus on the forecast of the onset of the 2015 El Nino event. Using a series of retrospective 9-month hindcasts, we assess the uncertainties of the forecasted chlorophyll by comparing the monthly total chlorophyll concentration from the forecast with the corresponding monthly ocean chlorophyll data from the Suomi-National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (S-NPP VIIRS) satellite. The forecast was able to reproduce the phasing of the variability in chlorophyll concentration in the Equatorial Pacific, including the beginning of the 2015-2016 El Nino. The anomaly correlation coefficient (ACC) was significant (p less than 0.05) for forecast at 1-month (R=0.33), 8-month (R=0.42) and 9-month (R=0.41) lead times. The root mean square error (RMSE) increased from 0.0399 microgram chl L(exp -1) for the 1-month lead forecast to a maximum of 0.0472 microgram chl L(exp -1) for the 9-month lead forecast indicating that the forecast of the amplitude of chlorophyll concentration variability was getting worse. Forecasts with a 3-month lead time were on average the closest to the S-NPP VIIRS data (23% or 0.033 microgram chl L(exp -1)) while the forecast with a 9-month lead time were the furthest (31% or 0.042 microgram chl L(exp -1)). These results indicate the potential for forecasting chlorophyll concentration in this region but also highlights various deficiencies and suggestions for improvements to the current biogeochemical forecasting system. This system provides an initial basis for future applications including the effects of El Nino events on fisheries and other ocean resources given improvements identified in the analysis of these results.

Forecasting Ocean Chlorophyll in the Equatorial Pacific.

PubMed

Rousseaux, Cecile S; Gregg, Watson W

2017-01-01

Using a global ocean biogeochemical model combined with a forecast of physical oceanic and atmospheric variables from the NASA Global Modeling and Assimilation Office, we assess the skill of a chlorophyll concentrations forecast in the Equatorial Pacific for the period 2012-2015 with a focus on the forecast of the onset of the 2015 El Niño event. Using a series of retrospective 9-month hindcasts, we assess the uncertainties of the forecasted chlorophyll by comparing the monthly total chlorophyll concentration from the forecast with the corresponding monthly ocean chlorophyll data from the Suomi-National Polar-orbiting Partnership Visible Infrared Imaging Radiometer Suite (S-NPP VIIRS) satellite. The forecast was able to reproduce the phasing of the variability in chlorophyll concentration in the Equatorial Pacific, including the beginning of the 2015-2016 El Niño. The anomaly correlation coefficient (ACC) was significant ( p < 0.05) for forecast at 1-month ( R = 0.33), 8-month ( R = 0.42) and 9-month ( R = 0.41) lead times. The root mean square error (RMSE) increased from 0.0399 μg chl L -1 for the 1-month lead forecast to a maximum of 0.0472 μg chl L -1 for the 9-month lead forecast indicating that the forecast of the amplitude of chlorophyll concentration variability was getting worse. Forecasts with a 3-month lead time were on average the closest to the S-NPP VIIRS data (23% or 0.033 μg chl L -1 ) while the forecast with a 9-month lead time were the furthest (31% or 0.042 μg chl L -1 ). These results indicate the potential for forecasting chlorophyll concentration in this region but also highlights various deficiencies and suggestions for improvements to the current biogeochemical forecasting system. This system provides an initial basis for future applications including the effects of El Niño events on fisheries and other ocean resources given improvements identified in the analysis of these results.

A rear-end collision risk assessment model based on drivers' collision avoidance process under influences of cell phone use and gender-A driving simulator based study.

PubMed

Li, Xiaomeng; Yan, Xuedong; Wu, Jiawei; Radwan, Essam; Zhang, Yuting

2016-12-01

Driver's collision avoidance performance has a direct link to the collision risk and crash severity. Previous studies demonstrated that the distracted driving, such as using a cell phone while driving, disrupted the driver's performance on road. This study aimed to investigate the manner and extent to which cell phone use and driver's gender affected driving performance and collision risk in a rear-end collision avoidance process. Forty-two licensed drivers completed the driving simulation experiment in three phone use conditions: no phone use, hands-free, and hand-held, in which the drivers drove in a car-following situation with potential rear-end collision risks caused by the leading vehicle's sudden deceleration. Based on the experiment data, a rear-end collision risk assessment model was developed to assess the influence of cell phone use and driver's gender. The cell phone use and driver's gender were found to be significant factors that affected the braking performances in the rear-end collision avoidance process, including the brake reaction time, the deceleration adjusting time and the maximum deceleration rate. The minimum headway distance between the leading vehicle and the simulator during the rear-end collision avoidance process was the final output variable, which could be used to measure the rear-end collision risk and judge whether a collision occurred. The results showed that although cell phone use drivers took some compensatory behaviors in the collision avoidance process to reduce the mental workload, the collision risk in cell phone use conditions was still higher than that without the phone use. More importantly, the results proved that the hands-free condition did not eliminate the safety problem associated with distracted driving because it impaired the driving performance in the same way as much as the use of hand-held phones. In addition, the gender effect indicated that although female drivers had longer reaction time than male drivers in critical situation, they were more quickly in braking with larger maximum deceleration rate, and they tended to keep a larger safety margin with the leading vehicle compared to male drivers. The findings shed some light on the further development of advanced collision avoidance technologies and the targeted intervention strategies about cell phone use while driving. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multifrequency zero-jitter delay-locked loop

NASA Astrophysics Data System (ADS)

Efendovich, Avner; Afek, Yachin; Sella, Coby; Bikowsky, Zeev

1994-01-01

The approach of an all-digital phase locked loop is used in this delay-locked loop circuit. This design is designated to a system with two processing units, a master CPU and a slave system chip, that share the same bus. It allows maximum utilization of the bus, as the minimal skew between the clocks of the two components significantly reduces idle periods, and also set-up and hold times. Changes in the operating frequency are possible, without falling out of synchronization. Due to the special lead-lag phase detector, the jitter of the clock is zero, when the loop is locked, under any working conditions.

Chaotic behaviour of high Mach number flows

NASA Technical Reports Server (NTRS)

Varvoglis, H.; Ghosh, S.

1985-01-01

The stability of the super-Alfvenic flow of a two-fluid plasma model with respect to the Mach number and the angle between the flow direction and the magnetic field is investigated. It is found that, in general, a large scale chaotic region develops around the initial equilibrium of the laminar flow when the Mach number exceeds a certain threshold value. After reaching a maximum the size of this region begins shrinking and goes to zero as the Mach number tends to infinity. As a result high Mach number flows in time independent astrophysical plasmas may lead to the formation of 'quasi-shocks' in the presence of little or no dissipation.

Spark-Timing Control Based on Correlation of Maximum-Economy Spark Timing, Flame-front Travel, and Cylinder-Pressure Rise

NASA Technical Reports Server (NTRS)

Cook, Harvey A; Heinicke, Orville H; Haynie, William H

1947-01-01

An investigation was conducted on a full-scale air-cooled cylinder in order to establish an effective means of maintaining maximum-economy spark timing with varying engine operating conditions. Variable fuel-air-ratio runs were conducted in which relations were determined between the spark travel, and cylinder-pressure rise. An instrument for controlling spark timing was developed that automatically maintained maximum-economy spark timing with varying engine operating conditions. The instrument also indicated the occurrence of preignition.

Onset of the convection in a supercritical fluid.

PubMed

Meyer, H

2006-01-01

A model is proposed that leads to the scaled relation tp/tau D=Ftp(Ra-Rac) for the development of convection in a pure fluid in a Rayleigh-Bénard cell after the start of the heat current at t=0. Here tp is the time of the first maximum of the temperature drop DeltaT(t) across the fluid layer, the signature of rapidly growing convection, tau D is the diffusion relaxation time, and Rac is the critical Rayleigh number. Such a relation was first obtained empirically from experimental data. Because of the unknown perturbations in the cell that lead to convection development beyond the point of the fluid instability, the model determines tp/tau D within a multiplicative factor Psi square root Rac(HBL), the only fit parameter product. Here Rac(HBL), of the order 10(3), is the critical Rayleigh number of the hot boundary layer and Psi is a fit parameter. There is then good agreement over more than four decades of Ra-Rac between the model and the experiments on supercritical 3He at various heat currents and temperatures. The value of the parameter Psi, which phenomenologically represents the effectiveness of the perturbations, is discussed in connection with predictions by El Khouri and Carlès of the fluid instability onset time.

Yeast and mammalian metabolism continuous monitoring by using pressure recording as an assessment technique for xenobiotic agent effects

NASA Astrophysics Data System (ADS)

Milani, Marziale; Ballerini, Monica; Ferraro, Lorenzo; Marelli, E.; Mazza, Francesca; Zabeo, Matteo

2002-06-01

Our work is devoted to the study of Saccharomyces cerevisiae and human lymphocytes cellular metabolism in order to develop a reference model to assess biological systems responses to chemical or physical agents exposure. CO2 variations inside test-tubes are measured by differential pressure sensors; pressure values are subsequently converted in voltage. The system allows to test up to 16 samples at the same time. Sampling manages up to 100 acquisitions per second. Values are recorded by a data acquisition card connected to a computer. This procedure leads to a standard curve (pressure variation versus time), typical of the cellular line, that describe cellular metabolism. The longest time lapse used is of 170 h. Different phases appear in this curve: an initial growth up to a maximum, followed by a decrement that leads to a typical depression (pressure value inside the test-tubes is lower than the initial one) after about 35 h from the beginning of yeast cells. The curve is reproducible within an experimental error of 4%. The analysis of many samples and the low cost of the devices allow a good statistical significance of the data. In particular as a test we will compare two sterilizing agents effects: UV radiation and amuchina.

Biotransference and biomagnification of selenium copper, cadmium, zinc, arsenic and lead in a temperate seagrass ecosystem from Lake Macquarie Estuary, NSW, Australia.

PubMed

Barwick, M; Maher, W

2003-10-01

In this study the biotransference of selenium copper, cadmium, zinc, arsenic and lead was measured in a contaminated seagrass ecosystem in Lake Macquarie, NSW, Australia, to determine if biomagnification of these trace metals is occurring and if they reach concentrations that pose a threat to the resident organisms or human consumers. Selenium was found to biomagnify, exceeding maximum permitted concentrations for human consumption within carnivorous fish tissue, the highest trophic level examined. Selenium concentrations measured within carnivorous fish were also above those shown to elicit sub-lethal effects in freshwater fish. As comparisons are made to selenium concentrations known to effect freshwater fish, inferences must be made with caution. There was no evidence of copper, cadmium, zinc or lead biomagnification within the food web examined. Copper, cadmium, zinc and lead concentrations were below concentrations shown to elicit adverse responses in biota. Copper concentrations within crustaceans M. bennettae and P. palagicus were found to exceed maximum permitted concentrations for human consumption. It is likely that copper concentrations within these species were accumulated due to the essential nature of this trace metal for many species of molluscs and crustaceans. Arsenic showed some evidence of biomagnification. Total arsenic concentrations are similar to those found in other uncontaminated marine ecosystems, thus arsenic concentrations are unlikely to cause adverse effects to aquatic organisms. Inorganic arsenic concentrations are below maximum permitted concentrations for human consumption.

Wind-influenced projectile motion

NASA Astrophysics Data System (ADS)

Bernardo, Reginald Christian; Perico Esguerra, Jose; Day Vallejos, Jazmine; Jerard Canda, Jeff

2015-03-01

We solved the wind-influenced projectile motion problem with the same initial and final heights and obtained exact analytical expressions for the shape of the trajectory, range, maximum height, time of flight, time of ascent, and time of descent with the help of the Lambert W function. It turns out that the range and maximum horizontal displacement are not always equal. When launched at a critical angle, the projectile will return to its starting position. It turns out that a launch angle of 90° maximizes the time of flight, time of ascent, time of descent, and maximum height and that the launch angle corresponding to maximum range can be obtained by solving a transcendental equation. Finally, we expressed in a parametric equation the locus of points corresponding to maximum heights for projectiles launched from the ground with the same initial speed in all directions. We used the results to estimate how much a moderate wind can modify a golf ball’s range and suggested other possible applications.

Optimization of batteries for plug-in hybrid electric vehicles

NASA Astrophysics Data System (ADS)

English, Jeffrey Robb

This thesis presents a method to quickly determine the optimal battery for an electric vehicle given a set of vehicle characteristics and desired performance metrics. The model is based on four independent design variables: cell count, cell capacity, state-of-charge window, and battery chemistry. Performance is measured in seven categories: cost, all-electric range, maximum speed, acceleration, battery lifetime, lifetime greenhouse gas emissions, and charging time. The performance of each battery is weighted according to a user-defined objective function to determine its overall fitness. The model is informed by a series of battery tests performed on scaled-down battery samples. Seven battery chemistries were tested for capacity at different discharge rates, maximum output power at different charge levels, and performance in a real-world automotive duty cycle. The results of these tests enable a prediction of the performance of the battery in an automobile. Testing was performed at both room temperature and low temperature to investigate the effects of battery temperature on operation. The testing highlighted differences in behavior between lithium, nickel, and lead based batteries. Battery performance decreased with temperature across all samples with the largest effect on nickel-based chemistries. Output power also decreased with lead acid batteries being the least affected by temperature. Lithium-ion batteries were found to be highly efficient (>95%) under a vehicular duty cycle; nickel and lead batteries have greater losses. Low temperatures hindered battery performance and resulted in accelerated failure in several samples. Lead acid, lead tin, and lithium nickel alloy batteries were unable to complete the low temperature testing regime without losing significant capacity and power capability. This is a concern for their applicability in electric vehicles intended for cold climates which have to maintain battery temperature during long periods of inactivity. Three sample optimizations were performed: a compact car, a, truck, and a sports car. The compact car benefits from increased battery capacity despite the associated higher cost. The truck returned the smallest possible battery of each chemistry, indicating that electrification is not advisable. The sports car optimization resulted in the largest possible battery, indicating large performance from increased electrification. These results mirror the current state of the electric vehicle market.

High-efficiency dynamic routing architecture for the readout of single photon avalanche diode arrays in time-correlated measurements

NASA Astrophysics Data System (ADS)

Cominelli, A.; Acconcia, G.; Peronio, P.; Rech, I.; Ghioni, M.

2017-05-01

In recent years, the Time-Correlated Single Photon Counting (TCSPC) technique has gained a prominent role in many fields, where the analysis of extremely fast and faint luminous signals is required. In the life science, for instance, the estimation of fluorescence time-constants with picosecond accuracy has been leading to a deeper insight into many biological processes. Although the many advantages provided by TCSPC-based techniques, their intrinsically repetitive nature leads to a relatively long acquisition time, especially when time-resolved images are obtained by means of a single detector, along with a scanning point system. In the last decade, TCSPC acquisition systems have been subjected to a fast trend towards the parallelization of many independent channels, in order to speed up the measure. On one hand, some high-performance multi-module systems have been already made commercially available, but high area and power consumption of each module have limited the number of channels to only some units. On the other hand, many compact systems based on Single Photon Avalanche Diodes (SPAD) have been proposed in literature, featuring thousands of independent acquisition chains on a single chip. The integration of both detectors and conversion electronic in the same pixel area, though, has imposed tight constraints on power dissipation and area occupation of the electronics, resulting in a tradeoff with performance, both in terms of differential nonlinearity and timing jitter. Furthermore, in the ideal case of simultaneous readout of a huge number of channels, the overall data rate can be as high as 100 Gbit/s, which is nowadays too high to be easily processed in real time by a PC. Typical adopted solutions involve an arbitrary dwell time, followed by a sequential readout of the converters, thus limiting the maximum operating frequency of each channel and impairing the measurement speed, which still lies well below the limit imposed by the saturation of the transfer rate towards the elaboration unit. We developed a novel readout architecture, starting from a completely different perspective: considering the maximum data rate we can manage with a PC, a limited set of conversion data is selected and transferred to the elaboration unit during each excitation period, in order to take full advantage of the bus bandwidth toward the PC. In particular, we introduce a smart routing logic, able to dynamically connect a large number of SPAD detectors to a limited set of high-performance external acquisition chains, paving the way for a more efficient use of resources and allowing us to effectively break the tradeoff between integration and performance, which affects the solutions proposed so far. The routing electronic features a pixelated architecture, while 3D-stacking techniques are exploited to connect each SPAD to its dedicated electronic, leading to a minimization of the overall number of interconnections crossing the integrated system, which is one of the main issues in high-density arrays.

Precision of computer-assisted core decompression drilling of the femoral head.

PubMed

Beckmann, J; Goetz, J; Baethis, H; Kalteis, T; Grifka, J; Perlick, L

2006-08-01

Osteonecrosis of the femoral head is a local destructive disease with progression into devastating stages. Left untreated it mostly leads to severe secondary osteoarthrosis and early endoprosthetic joint replacement. Core decompression by exact drilling into the ischemic areas can be performed in early stages according to Ficat or ARCO. Computer-aided surgery might enhance the precision of the drilling and lower the radiation exposure time of both staff and patients. The aim of this study was to evaluate the precision of the fluoroscopically based VectorVision navigation system in an in vitro model. Thirty sawbones were prepared with a defect filled up with a radiopaque gypsum sphere mimicking the osteonecrosis. Twenty sawbones were drilled by guidance of an intraoperative navigation system VectorVision (BrainLAB, Munich, Germany) and 10 sawbones by fluoroscopic control only. No gypsum sphere was missed. There was a statistically significant difference regarding the three-dimensional deviation (Euclidian norm) as well as maximum deviation in x-, y- or z-direction (maximum norm) to the desired mid-point of the lesion, with a mean of 0.51 and 0.4 mm in the navigated group and 1.1 and 0.88 mm in the control group, respectively. Furthermore, significant difference was found in the number of drilling corrections as well as the radiation time needed: no second drilling or correction of drilling direction was necessary in the navigated group compared to 1.4 in the control group. The radiation time needed was less than 1 s compared to 3.1 s, respectively. The fluoroscopy-based VectorVision navigation system shows a high feasibility of computer-guided drilling with a clear reduction of radiation exposure time and can therefore be integrated into clinical routine. The additional time needed is acceptable regarding the simultaneous reduction of radiation time.

Frequency Dependence of Helioseismic Measurements of the Center-to-Limb Effect and Flow-induced Travel-time Shifts

NASA Astrophysics Data System (ADS)

Chen, Ruizhu; Zhao, Junwei

2018-02-01

Time–distance helioseismology measures acoustic travel times to infer the structure and flow field of the solar interior; however, both the mean travel times and the travel-time shifts suffer systematic center-to-limb variations, which complicate the interpretation and inversions of the time–distance measurements. In particular, the center-to-limb variation in travel-time shifts (CtoL effect) has a significant impact on the inference of the Sun’s meridional circulation, and needs to be removed from the helioseismic measurements, although the observational properties and the physical cause of the CtoL effect have yet to be investigated. In this study, we measure the CtoL effect in the frequency domain using Doppler-velocity data from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, and study its properties as a function of disk-centric distance, travel distance, and frequency of acoustic waves. It is found that the CtoL effect has a significant frequency dependence—it reverses sign at a frequency around 5.4 mHz and reaches maximum at around 4.0 mHz before the sign reversal. The tendency of frequency dependence varies with disk-centric distance in a way that both the sign-reversal frequency and the maximum-value frequency decrease closer to the limb. The variation tendency does not change with travel distance, but the variation magnitude is approximately proportional to travel distance. For comparison, the flow-induced travel-time shifts show little frequency dependence. These observational properties provide more clues on the nature of the CtoL effect, and also possibly lead to new ways of effect-removal for a more robust determination of the deep meridional flow.

Preoperative fasting for elective surgery in a regional hospital in Oman.

PubMed

Abdullah Al Maqbali, Mohammed

2016-07-28

A fasting period before anesthesia is necessary to avoid the aspiration of stomach contents, which can be threatening to the patient's life. Guidelines from professional societies in the USA and UK recommend that healthy patients fast for 6 hours from solid food and 2 hours from liquids. Despite this, many institutions still practice nil-by-mouth after midnight. This can affect the patient's recovery after surgery, and increase the length of stay in hospital. The aim of this study was to assess the duration of fasting before elective surgery on the part of adult patients. A prospective study was conducted to identify the fasting time and complications among surgical patients undergoing elective surgery over a 4-month period. The patients were asked for preoperative fasting times, and the complication. The demographic data were taken from the patients' files. A total of 169 patients were included in the study, 88 male and 81 female. The minimum and maximum fasting hours with regard to food were 7 hours and 19 hours, respectively; all the patients fasted from food for longer than the recommended time. The minimum and maximum fasting hours for fluids were 4 hours and 19 hours, respectively; all the patients fasted from fluid for longer than the recommended time. Most of the patients fasted from food and fluids for more than the time recommended by the American Society of Anaesthesiologists, the Royal College of Nursing, the Association of Anaesthetists of Great Britain and Ireland and the Royal College of Anaesthetists. Excessive fasting could lead to discomfort and possible morbidity in surgical patients. The surgical team needs to collaborate to reduce the fasting time by revising the operative list.

On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

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

Dennis H. LeMieux

2005-04-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs havemore » been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION

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

Dennis H. LeMieux

2003-10-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

ON-LINE THERMAL BARRIER COATING MONITORING FOR REAL-TIME FAILURE PROTECTION AND LIFE MAXIMIZATION

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

Dennis H. LeMieux

2003-07-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization,'' to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability, availability, and maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCsmore » have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can, therefore, accelerate the degradation of substrate component materials and eventually lead to a premature failure of critical components and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

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

Dennis H. LeMieux

2005-10-01

Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Power Generation, Inc proposed a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs havemore » been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Power Generation, Inc. has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.« less

Nonstationarity of daily rainfall annual maxima in Puglia (Southern Italy)

NASA Astrophysics Data System (ADS)

Totaro, Vincenzo; Gioia, Andrea; Iacobellis, Vito

2017-04-01

Extreme flood events occurring in the last decades, due to climatic conditions in rapid evolution and/or changes in land cover, has lead the scientific community to develop and improve probabilistic techniques in order to take into account these effects, as also requested by the EU Floods Directive 2007/60. In the recent literature are becoming more popular studies that investigate the nonstationarity of the variables usually treated in hydrology through the analysis of their trend behavior. In this context it is also useful to assess the impact that the climate and /or land cover modifications have on the performances of the probabilistic stationary models used to predict hydrological variables such as rainfall and flood peaks. Among several proposed approaches, we use the redefined concept of return period and risk by considering the variability over time of the position parameter of the GEV distribution, with the subsequent discussion about the implications of analytical and technical characters. The analysis was carried out on the time series of annual maximum of daily precipitation available for a broad number of rainfall gauged stations in Puglia (Southern Italy). The investigation, conducted at the regional scale, leads to the identification of areas with different significativity of the statistical tests usually performed in order to assess nonstationarity. The evaluated change of return period leads to considerations useful to redesign methods for regional analysis of flood frequency.

Biosorption of lead ions from aqueous effluents by rapeseed biomass.

PubMed

Morosanu, Irina; Teodosiu, Carmen; Paduraru, Carmen; Ibanescu, Dumitrita; Tofan, Lavinia

2017-10-25

Lead, as well as other heavy metals, is regarded as priority pollutant due to its non-biodegradability, toxicity and persistence in the environment. In this study, rapeseed biomass was used in the biosorption of Pb(II) ions in batch and dynamic conditions, as well as with tests for industrial wastewater. The influence of initial concentration (5-250mg/L), pH and contact time (0.5-6h) was investigated. The kinetic data modeling resulted in good correlations with the pseudo-second order and intraparticle diffusion models. The maximum sorption capacities of Pb(II) were 18.35, 21.29 and 22.7mg/L at 4, 20 and 50°C, respectively. Thermodynamic parameters indicated the spontaneity and endothermic nature of lead biosorption on rapeseed biomass. The biosorption mechanism involves both physical and chemical interactions. The breakthrough curves at 50 and 100mg/L were determined and evaluated under dynamic conditions. The breakthrough time lowered with increasing the influent Pb(II) concentration. The experimental data obtained from fixed-bed column tests were well fitted by Thomas and Yoon-Nelson models. The calculated sorption capacities were in good agreement with the uptake capacity of Langmuir model. The applicability of rapeseed to be used as a sorbent for Pb(II) ions from real wastewater was tested, and Pb(II) removal efficiency of 94.47% was obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

[Estimation of maximum acceptable concentration of lead and cadmium in plants and their medicinal preparations].

PubMed

Zitkevicius, Virgilijus; Savickiene, Nijole; Abdrachmanovas, Olegas; Ryselis, Stanislovas; Masteiková, Rūta; Chalupova, Zuzana; Dagilyte, Audrone; Baranauskas, Algirdas

2003-01-01

Heavy metals (lead, cadmium) are possible dashes which quantity is defined by the limiting acceptable contents. Different drugs preparations: infusions, decoctions, tinctures, extracts, etc. are produced using medicinal plants. The objective of this research was to study the impurities of heavy metals (lead, cadmium) in medicinal plants and some drug preparations. We investigated liquid extracts of fruits Crataegus monogyna Jacq. and herbs of Echinacea purpurea Moench., tinctures--of herbs Leonurus cardiaca L. The raw materials were imported from Poland. Investigations were carried out in cooperation with the Laboratory of Antropogenic Factors of the Institute for Biomedical Research. Amounts of lead and cadmium were established after "dry" mineralisation using "Perkin-Elmer Zeeman/3030" model electrothermic atomic absorption spectrophotometer (ETG AAS/Zeeman). It was established that lead is absorbed most efficiently after estimation of absorption capacity of cellular fibers. About 10.73% of lead crosses tinctures and extracts, better cadmium--49.63%. Herbs of Leonurus cardiaca L. are the best in holding back lead and cadmium. About 14.5% of lead and cadmium crosses the tincture of herbs Leonurus cardiaca L. We estimated the factors of heavy metals (lead, cadmium) in the liquid extracts of Crataegus monogyna Jacq. and Echinacea purpurea Moench., tincture of Leonurus cardiaca L. after investigations of heavy metals (lead, cadmium) in drugs and preparations of it. The amounts of heavy metals (lead, cadmium) don't exceed the allowable norms in fruits of Crataegus monogyna Jacq., herbs of Leonurus cardiaca L. and Echinacea purpurea Moench. after estimation of lead and cadmium extraction factors, the maximum of acceptable daily intake and the quantity of drugs consumption in day.

Leaded eyeglasses substantially reduce radiation exposure of the surgeon's eyes during acquisition of typical fluoroscopic views of the hip and pelvis.

PubMed

Burns, Sean; Thornton, Raymond; Dauer, Lawrence T; Quinn, Brian; Miodownik, Daniel; Hak, David J

2013-07-17

Despite recommendations to do so, few orthopaedists wear leaded glasses when performing operative fluoroscopy. Radiation exposure to the ocular lens causes cataracts, and regulatory limits for maximum annual occupational exposure to the eye continue to be revised downward. Using anthropomorphic patient and surgeon phantoms, radiation dose at the surgeon phantom's lens was measured with and without leaded glasses during fluoroscopic acquisition of sixteen common pelvic and hip views. The magnitude of lens dose reduction from leaded glasses was calculated by dividing the unprotected dose by the dose measured behind leaded glasses. On average, the use of leaded glasses reduced radiation to the surgeon phantom's eye by tenfold, a 90% reduction in dose. However, there was widespread variation in the amount of radiation that reached the phantom surgeon's eye among the various radiographic projections we studied. Without leaded glasses, the dose measured at the surgeon's lens varied more than 250-fold among these sixteen different views. In addition to protecting the surgeon's eye from the deleterious effects of radiation, the use of leaded glasses could permit an orthopaedist to perform fluoroscopic views on up to ten times more patients before reaching the annual dose limit of 20 mSv of radiation to the eye recommended by the International Commission on Radiological Protection. Personal safety and adherence to limits of occupational radiation exposure should compel orthopaedists to wear leaded glasses for fluoroscopic procedures if other protective barriers are not in use. Leaded glasses are a powerful tool for reducing the orthopaedic surgeon's lens exposure to radiation during acquisition of common intraoperative fluoroscopic views.

Cross-correlation of point series using a new method

NASA Technical Reports Server (NTRS)

Strothers, Richard B.

1994-01-01

Traditional methods of cross-correlation of two time series do not apply to point time series. Here, a new method, devised specifically for point series, utilizes a correlation measure that is based in the rms difference (or, alternatively, the median absolute difference) between nearest neightbors in overlapped segments of the two series. Error estimates for the observed locations of the points, as well as a systematic shift of one series with respect to the other to accommodate a constant, but unknown, lead or lag, are easily incorporated into the analysis using Monte Carlo techniques. A methodological restriction adopted here is that one series be treated as a template series against which the other, called the target series, is cross-correlated. To estimate a significance level for the correlation measure, the adopted alternative (null) hypothesis is that the target series arises from a homogeneous Poisson process. The new method is applied to cross-correlating the times of the greatest geomagnetic storms with the times of maximum in the undecennial solar activity cycle.

Cosmetic formulations containing Lithospermum erythrorhizon root extract show moisturizing effects on human skin.

PubMed

Chang, Man-Jau; Huang, Huey-Chun; Chang, Hsien-Cheh; Chang, Tsong-Min

2008-07-01

Retention of water in the stratum corneum of skin epidermis plays an important role in regulation of skin function. Loss of water may decline skin appearance gradually and lead to irregular skin disorders. The root extract of Lithospermum erythrorhizon (LES) is known for its various pharmacological activities. However, the potential skin care effect of LES is not clear. The aim of this study was to evaluate the moisturizing efficacy and skin barrier repairing activity of LES. For this study, 30 healthy Asian females (age 20-30) with healthy skin had applied the test emulsions twice daily over a period of 28 days. The skin properties were measured by skin bioengineering techniques. Our preliminary results indicated that LES show moisturizing effect on skin hydration in a time- and dose-dependent pattern, and the maximum increase in skin humidity was 11.77 +/- 1.18% for emulsion LES5.00. Particularly, LES-containing emulsions significantly improve skin barrier function by decreasing the value of transepidermal water loss (TEWL) in a time- and dose-dependent pattern, and the maximum decrease in TEWL value was 7.68 +/- 0.79% for emulsion LES5.00. Taken together, our data demonstrate that LES is more effective in increasing skin humidity and decreasing the TEWL values, indicating the potential skin care effects of LES.

Comparison of polynomial and neural fuzzy models as applied to the ethanolamine pulping of vine shoots.

PubMed

Jiménez, L; Angulo, V; Caparrós, S; Ariza, J

2007-12-01

The influence of operational variables in the pulping of vine shoots by use of ethanolamine [viz. temperature (155-185 degrees C), cooking time (30-90min) and ethanolamine concentration (50-70% v/v)] on the properties of the resulting pulp (viz. yield, kappa index, viscosity and drainability) was studied. A central composite factorial design was used in conjunction with the software BMDP and ANFIS Edit Matlab 6.5 to develop polynomial and fuzzy neural models that reproduced the experimental results of the dependent variables with errors less than 10%. Both types of models are therefore effective with a view to simulating the ethanolamine pulping process. Based on the proposed equations, the best choice is to use values of the operational valuables resulting in near-optimal pulp properties while saving energy and immobilized capital on industrial facilities by using lower temperatures and shorter processing times. One combination leading to near-optimal properties with reduced costs is using a temperature of 180 degrees C and an ethanolamine concentration of 60% for 60min, to obtain pulp with a viscosity of 6.13% lower than the maximum value (932.8ml/g) and a drainability of 5.49% lower than the maximum value (71 (o)SR).

Characterization of coal gasification slag-based activated carbon and its potential application in lead removal.

PubMed

Xu, Yiting; Chai, Xiaoli

2018-02-01

Highly porous activated carbons were prepared from a coal gasification slag (CGS) precursor, by KOH activation to remove Pb 2+ from aqueous solution. The effects of pretreatment methods and activation parameters on the properties of the activated carbon were investigated, such as KOH/CGS mass ratio, activation temperature and activation time. The results showed that the maximum Brunauer-Emmett-Teller surface area and total pore volume with the value of 2481 m 2  g -1 and of 1.711 cc g -1 were obtained at a KOH/CGS ratio of 3.0 by physical mixing, an activation temperature of 750°C and an activation time of 80 min. SEM, FTIR and EA analyses indicated that pronounced pores existed on the exterior surface of the activated samples, and the contents of H and O decreased due to the loss of surface chemical groups during activation. Experimental data for the Pb 2+ adsorption were fitted well by Freundlich equation and a pseudo-second-order model with a maximum experimental adsorption capacity of 141 mg/g. All of the results indicated that CGS could be a promising material to prepare porous activated carbon for Pb 2+ removal from wastewater.

Training for Power and Speed: Effects of Increasing or Decreasing Jump Squat Velocity in Elite Young Soccer Players.

PubMed

Loturco, Irineu; Nakamura, Fabio Y; Kobal, Ronaldo; Gil, Saulo; Abad, César C Cal; Cuniyochi, Rogério; Pereira, Lucas A; Roschel, Hamilton

2015-10-01

The aim of this study was to test the effects of 2 different velocity-oriented power training regimens by either increasing or decreasing the jump squat velocity during jump training sessions applied 3 times a week for 6 weeks in soccer players. Twenty-four elite under-20 soccer players were randomly assigned to an increased bar velocity group (IVG) or a reduced bar velocity group (RVG). Athletes had their countermovement jump heights, mean propulsive velocities (MPVs) in jump squat, leg press maximum dynamic strength (1 repetition maximum [RM]), 20-m sprint times, and zig-zag change of direction (COD) abilities assessed before and after the intervention. Performance in all tests improved after training in both groups. However, greater gains in 1RM and MPV using 50-90% of body mass (BM) were noted for the RVG. The IVG demonstrated greater improvements in speed at 5, 10, and 20 m and MPV with no additional external load and with 40% BM. Both groups improved similarly in countermovement jumps and COD. To conclude, both velocity-oriented power training regimens were effective in eliciting neuromechanical adaptations, leading to better strength/power/speed performances, and the choice as to the most suitable method should be tailored according to players' needs/deficiencies.

Dendrometric measurements reveal stages leading to tree mortality in a semiarid pine forest

NASA Astrophysics Data System (ADS)

Tatarinov, Fyodor; Preisler, Yakir; Klein, Tamir; Rotenberg, Eyal; Yakir, Dan

2017-04-01

Increasing frequency and intensity of climatic extreme events, such as droughts may lead to increasing vulnerability of forests, especially in semi-arid regions. In the spring of 2016 mortality was observed among trees used for sap flow (SF) and dendrometry measurements in the semi-arid Fluxnet pine forest site of Yatir in Israel (280mm annual mean precipitation). This was accompanied by bark-beetle attack, and with visual drying of needles starting in April 2016. Comparative analysis of dendrometry and sap flux (SF) measurements in 31 trees of which 7 died and 24 survived permitted identification of the stages leading to tree mortality. Distinction between dying and surviving trees was identified in the dendrometric measurements from Nov. 2015, about five months before visual mortality signs: First, clear decline in diameter (DBH) was observed in all dying trees, whereas DBH of living trees remained constant until the first rain in January 2016 followed by growth. Second, the diurnal patterns in DBH showed a gradual shift of the diurnal DBH maximum from noon-time to early morning from the summer of 2015 to the spring of 2016 in surviving trees, whereas in dying trees it remained stable around noontime. Third, the diurnal swelling/shrinkage dynamics, assumed to reflect water use and storage dynamics, showed clear decline in magnitude, down to near zero, in the dying trees while regular daily cycle continued in the surviving trees. In September 2015 Shoot measurements showed midnight minimum of leaf water potential, lower than in living trees (-4.5 vs. -3.6 MPa respectively). Sap flow measurements were not sufficiently sensitive during the non-active season (fall and early winter) and indicated changes only after the first rain in January 2016. At this time, SF showed dramatic increase in SF with typical midday maximum in the surviving trees, whereas in dying trees SF remained low and irregular. The results show that indicators of mortality can be detected at least 5 months before visual signs are observed, and demonstrate the interacting effects of carbon economy (growth) and tree water management (radial water movement and storage) on the development of mortality in Aleppo pine trees.

Model 9975 Life Extension Test Package 3 - Interim Report - January 2017

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

Daugherty, W.

2017-01-31

Life extension package LE3 (9975-03203) has been instrumented and subjected to an elevated temperature environment for approximately 8 years. During this time, the cane fiberboard has been maintained at a maximum temperature of ~160 - 165 °F, which was established by a combination of internal (19 watts) and external heat sources. Several tests and parameters were used to characterize the package components. Results from these tests generally indicate agreement between this full-scale shipping package and small-scale laboratory tests on fiberboard samples, including the degradation models based on the laboratory tests. These areas of agreement include the rate of change ofmore » fiberboard weight, dimensions and density, and change in fiberboard thermal conductivity. Corrosion of the lead shield occurred at a high rate during the first several weeks of aging, but dropped significantly after most of the moisture in the fiberboard migrated away from the lead shield. Dimensional measurements of the lead shield indicate that no significant creep deformation has occurred. This is consistent with literature data that predict a very small creep deformation for the time at temperature experienced by this package. The SCV O-rings were verified to remain leak-tight after ~5 years aging at an average temperature of ~170 °F. This package provides an example of the extent to which moisture within a typical fiberboard assembly can redistribute in the presence of a temperature gradient such as might be created by a 19 watt internal heat load. The majority of water within the fiberboard migrated to the bottom layers of fiberboard, with approximately 2 kg of water (2 liters) eventually escaping from the package. Two conditions have developed that are not consistent with package certification requirements. The axial gap at the top of the package increased to a maximum value of 1.549 inches, exceeding the 1 inch criterion. In addition, staining and/or corrosion have formed in a few spots on the drum. However, the package remains capable of performing its function. Aging of this package continues.« less

40 CFR 421.93 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Metallurgical Acid Plants Subcategory § 421.93 Effluent limitations guidelines representing the degree of...—Metallurgical Acid Plant—BAT Effluent Limitations Pollutant or pollutant property Maximum for any 1 day Maximum... 1.584 Cadmium 0.511 0.204 Copper 3.269 1.558 Lead 0.715 0.332 Zinc 2.605 1.073 Fluoride 1 89.390 50...

40 CFR 421.93 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Metallurgical Acid Plants Subcategory § 421.93 Effluent limitations guidelines representing the degree of...—Metallurgical Acid Plant—BAT Effluent Limitations Pollutant or pollutant property Maximum for any 1 day Maximum... 1.584 Cadmium 0.511 0.204 Copper 3.269 1.558 Lead 0.715 0.332 Zinc 2.605 1.073 Fluoride 1 89.390 50...

40 CFR 421.306 - Pretreatment standards for new sources.

Code of Federal Regulations, 2013 CFR

2013-07-01

... average mg/kg (pounds per million pounds) of TiCl4 produced Chromium (total) 0.346 0.140 Lead 0.262 0.122... Maximum for monthly average mg/kg (pounds per million pounds) of TiCl4 produced Chromium (total) 0.385 0... for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of TiCl4 handled Chromium...

40 CFR 421.306 - Pretreatment standards for new sources.

Code of Federal Regulations, 2014 CFR

2014-07-01

... average mg/kg (pounds per million pounds) of TiCl4 produced Chromium (total) 0.346 0.140 Lead 0.262 0.122... Maximum for monthly average mg/kg (pounds per million pounds) of TiCl4 produced Chromium (total) 0.385 0... for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of TiCl4 handled Chromium...

40 CFR 421.306 - Pretreatment standards for new sources.

Code of Federal Regulations, 2012 CFR

2012-07-01

... average mg/kg (pounds per million pounds) of TiCl4 produced Chromium (total) 0.346 0.140 Lead 0.262 0.122... Maximum for monthly average mg/kg (pounds per million pounds) of TiCl4 produced Chromium (total) 0.385 0... for any 1 day Maximum for monthly average mg/kg (pounds per million pounds) of TiCl4 handled Chromium...

A comparison of climatological observing windows and their impact on detecting daily temperature extrema

NASA Astrophysics Data System (ADS)

Žaknić-Ćatović, Ana; Gough, William A.

2018-04-01

Climatological observing window (COW) is defined as a time frame over which continuous or extreme air temperature measurements are collected. A 24-h time interval, ending at 00UTC or shifted to end at 06UTC, has been associated with difficulties in characterizing daily temperature extrema. A fixed 24-h COW used to obtain the temperature minima leads to potential misidentification due to fragmentation of "nighttime" into two subsequent nighttime periods due to the time discretization interval. The correct identification of air temperature extrema is achievable using a COW that identifies daily minimum over a single nighttime period and maximum over a single daytime period, as determined by sunrise and sunset. Due to a common absence of hourly air temperature observations, the accuracy of the mean temperature estimation is dependent on the accuracy of determination of diurnal air temperature extrema. Qualitative and quantitative criteria were used to examine the impact of the COW on detecting daily air temperature extrema. The timing of the 24-h observing window occasionally affects the determination of daily extrema through a mischaracterization of the diurnal minima and by extension can lead to errors in determining daily mean temperature. Hourly air temperature data for the time period from year 1987 to 2014, obtained from Toronto Buttonville Municipal Airport weather station, were used in analysis of COW impacts on detection of daily temperature extrema and calculation of annual temperature averages based on such extrema.

40 CFR 464.33 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2010 CFR

2010-07-01

.../billion SCF of air scrubbed) effluent limitations for copper, lead, zinc, and total phenols. For non...) of metal poured Copper (T) 0.0129 0.0071 Lead (T) 0.0237 0.0116 Zinc (T) 0.0437 0.0165 Maximum for... Lead (T) 0.53 0.26 0.0067 Zinc (T) 0.98 0.37 0.0116 1 kg/1,000 kkg (pounds per million pounds) of metal...

40 CFR 464.33 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2011 CFR

2011-07-01

.../billion SCF of air scrubbed) effluent limitations for copper, lead, zinc, and total phenols. For non...) of metal poured Copper (T) 0.0129 0.0071 Lead (T) 0.0237 0.0116 Zinc (T) 0.0437 0.0165 Maximum for... Lead (T) 0.53 0.26 0.0067 Zinc (T) 0.98 0.37 0.0116 1 kg/1,000 kkg (pounds per million pounds) of metal...

Experimental study of pressure and heating rate on a swept cylindrical leading edge resulting from swept shock wave interference. M.S. Thesis

NASA Technical Reports Server (NTRS)

Glass, Christopher E.

1989-01-01

The effects of cylindrical leading edge sweep on surface pressure and heat transfer rate for swept shock wave interference were investigated. Experimental tests were conducted in the Calspan 48-inch Hypersonic Shock Tunnel at a nominal Mach number of 8, nominal unit Reynolds number of 1.5 x 10 to the 6th power per foot, leading edge and incident shock generator sweep angles of 0, 15, and 30 deg, and incident shock generator angle-of-attack fixed at 12.5 deg. Detailed surface pressure and heat transfer rate on the cylindircal leading edge of a swept shock wave interference model were measured at the region of the maximum surface pressure and heat transfer rate. Results show that pressure and heat transfer rate on the cylindrical leading edge of the shock wave interference model were reduced as the sweep was increased over the range of tested parameters. Peak surface pressure and heat transfer rate on the cylinder were about 10 and 30 times the undisturbed flow stagnation point value, respectively, for the 0 deg sweep test. A comparison of the 15 and 30 deg swept results with the 0 deg swept results showed that peak pressure was reduced about 13 percent and 44 percent, respectively, and peak heat transfer rate was reduced about 7 percent and 27 percent, respectively.

Integrating Low-Cost Mems Accelerometer Mini-Arrays (mama) in Earthquake Early Warning Systems

NASA Astrophysics Data System (ADS)

Nof, R. N.; Chung, A. I.; Rademacher, H.; Allen, R. M.

2016-12-01

Current operational Earthquake Early Warning Systems (EEWS) acquire data with networks of single seismic stations, and compute source parameters assuming earthquakes to be point sources. For large events, the point-source assumption leads to an underestimation of magnitude, and the use of single stations leads to large uncertainties in the locations of events outside the network. We propose the use of mini-arrays to improve EEWS. Mini-arrays have the potential to: (a) estimate reliable hypocentral locations by beam forming (FK-analysis) techniques; (b) characterize the rupture dimensions and account for finite-source effects, leading to more reliable estimates for large magnitudes. Previously, the high price of multiple seismometers has made creating arrays cost-prohibitive. However, we propose setting up mini-arrays of a new seismometer based on low-cost (<$150), high-performance MEMS accelerometer around conventional seismic stations. The expected benefits of such an approach include decreasing alert-times, improving real-time shaking predictions and mitigating false alarms. We use low-resolution 14-bit Quake Catcher Network (QCN) data collected during Rapid Aftershock Mobilization Program (RAMP) in Christchurch, NZ following the M7.1 Darfield earthquake in September 2010. As the QCN network was so dense, we were able to use small sub-array of up to ten sensors spread along a maximum area of 1.7x2.2 km2 to demonstrate our approach and to solve for the BAZ of two events (Mw4.7 and Mw5.1) with less than ±10° error. We will also present the new 24-bit device details, benchmarks, and real-time measurements.

[Leisure-time sport activities and cardiac outpatient therapy in coronary patients].

PubMed

Heitkamp, Hans-Christian; Schimpf, Thomas M; Hipp, Arno; Niess, Andreas

2005-03-01

Exercise intensity in coronary patients is controlled by heart rate measurements. Very few investigations have compared the maximum heart rate in cardiac outpatient groups, in leisure-time sport activities, and especially in swimming. Within different exercise conditions 21 coronary patients, nine in well-compensated cardiac condition joining a training group and twelve joining the exercise group with lower intensity, without signs of heart failure, engaged in an incremental bicycle ergometry. A six-lead ECG was derived at the same time with a 24-h ECG. The performance tolerance was measured by the pulse limit derived in 20 patients; one patient failed to show signs of subjective or objective ischemia. During a 24-h ECG monitoring, the patients took part in a 1-h standardized cardiac outpatient program, a standardized swimming program 4 x 25 m, and a typical self-selected leisure-time activity. The patients showed a peak work capacity of 2.2 W/kg and a symptom-free work capacity of 1.3 W/kg. The derived upper heart rate limit was passed during swimming by 19, during leisure-time activity by 16, and during cardiac outpatient program by two patients. The maximum of the mean overriding the limit occurred in leisure-time activity. Signs of ischemia occurred during ergometry in 15, during swimming training in ten patients, during leisure-time activity in eight, and during cardiac outpatient therapy in one. Arrhythmia < Lown IVa was documented on the ergometer in 15, during leisure-time sport activity in 15, during cardiac outpatient therapy in 17, and during swimming in eight patients. Arrhythmia Lown IVa occurred in one patient each during ergometry, leisure sports, and during the night. Coronary patients are in danger to exercise beyond the pulse limit during swimming and other leisure-time sports and not during cardiac outpatient therapy. The upper heart rate limit should be observed during swimming and other endurance leisure-time activities, and is of little importance during cardiac outpatient therapy.

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

Tian, Zehua, E-mail: zehuatian@126.com; Wang, Jieci; Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, Hunan 410081

We show how the use of entanglement can enhance the precision of the detection of the Unruh effect with an accelerated probe. We use a two-level atom interacting relativistically with a quantum field as the probe, and treat it as an open quantum system to derive the master equation governing its evolution. By means of quantum state discrimination, we detect the accelerated motion of the atom by examining its time evolving state. It turns out that the optimal strategy for the detection of the Unruh effect, to which the accelerated atom is sensitive, involves letting the atom-thermometer equilibrate with themore » thermal bath. However, introducing initial entanglement between the detector and an external degree of freedom leads to an enhancement of the sensitivity of the detector. Also, the maximum precision is attained within finite time, before equilibration takes place.« less

The Meteor Section of the Visnjan School of Astronomy 1993

NASA Astrophysics Data System (ADS)

Korlevic, K.

In the last five years, the Visnjan Observatory started a new international astronomical summer workshop. Every year, on this educational activity, students have been thought the IMO standards of visual observation. Meteor astronomy was chosen as the leading activity because of its ability to bring people together, and because of the continuous flux of information through the IMO and the journal WGN, in the time when other sources of information were cut off by the war situation. The time of this years's school (August 7-20) covered the exceptional 1993 Perseids maximum. The Visnjan School of Astronomy is also an educational and psychological experiment, and our goal is finding a better means of introducing gifted students to science through astronomy workshops. In that effort we are also trying to increase the number of future meteor observers.

Treatment of lead contaminated water by a PVDF membrane that is modified by zirconium, phosphate and PVA.

PubMed

Zhao, Dandan; Yu, Yang; Chen, J Paul

2016-09-15

Lead contamination is one of the most serious problems in drinking water facing humans. In this study, a novel zirconium phosphate modified polyvinyl alcohol (PVA)-PVDF membrane was developed for lead removal. The zirconium ions and PVA were firstly coated onto a PVDF membrane through crosslinking reactions with glutaraldehyde, which was then modified by phosphate. The adsorption kinetics study showed that most of ultimate uptake occurred in 5 h. The adsorption increased with an increase in pH; the optimal adsorption was achieved at pH 5.5. The experimental data were better described by Langmuir equation than Freundlich equation; the maximum adsorption capacity was 121.2 mg-Pb/g at pH 5.5, much higher than other reported adsorptive membranes. The membrane exhibited a higher selectivity for lead over zinc with a relative selectivity coefficient (Pb(2+)/Zn(2+)) of 9.92. The filtration study showed that the membrane with an area of 12.56 cm(2) could treat 13.9 L (equivalent to 73,000 bed volumes) of lead containing wastewater with an influent concentration of 224.5 μ g/L to meet the maximum contaminant level of 15 μ g/L. It was demonstrated that the membrane did well in the removal of lead in both simulated wastewater and lead-spiked reservoir water and had a good reusability in its applications. The XPS studies revealed that the lead uptake was mainly due to cation exchange between hydrogen ions and lead ions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Survival analysis of clinical mastitis data using a nested frailty Cox model fit as a mixed-effects Poisson model.

PubMed

Elghafghuf, Adel; Dufour, Simon; Reyher, Kristen; Dohoo, Ian; Stryhn, Henrik

2014-12-01

Mastitis is a complex disease affecting dairy cows and is considered to be the most costly disease of dairy herds. The hazard of mastitis is a function of many factors, both managerial and environmental, making its control a difficult issue to milk producers. Observational studies of clinical mastitis (CM) often generate datasets with a number of characteristics which influence the analysis of those data: the outcome of interest may be the time to occurrence of a case of mastitis, predictors may change over time (time-dependent predictors), the effects of factors may change over time (time-dependent effects), there are usually multiple hierarchical levels, and datasets may be very large. Analysis of such data often requires expansion of the data into the counting-process format - leading to larger datasets - thus complicating the analysis and requiring excessive computing time. In this study, a nested frailty Cox model with time-dependent predictors and effects was applied to Canadian Bovine Mastitis Research Network data in which 10,831 lactations of 8035 cows from 69 herds were followed through lactation until the first occurrence of CM. The model was fit to the data as a Poisson model with nested normally distributed random effects at the cow and herd levels. Risk factors associated with the hazard of CM during the lactation were identified, such as parity, calving season, herd somatic cell score, pasture access, fore-stripping, and proportion of treated cases of CM in a herd. The analysis showed that most of the predictors had a strong effect early in lactation and also demonstrated substantial variation in the baseline hazard among cows and between herds. A small simulation study for a setting similar to the real data was conducted to evaluate the Poisson maximum likelihood estimation approach with both Gaussian quadrature method and Laplace approximation. Further, the performance of the two methods was compared with the performance of a widely used estimation approach for frailty Cox models based on the penalized partial likelihood. The simulation study showed good performance for the Poisson maximum likelihood approach with Gaussian quadrature and biased variance component estimates for both the Poisson maximum likelihood with Laplace approximation and penalized partial likelihood approaches. Copyright © 2014. Published by Elsevier B.V.

Lead-free multilayer piezoelectric transformer.

PubMed

Guo, Mingsen; Jiang, X P; Lam, K H; Wang, S; Sun, C L; Chan, Helen L W; Zhao, X Z

2007-01-01

In this article, a multilayer piezoelectric transformer based on lead-free Mn-doped 0.94(Bi(12)Na(12))TiO(3)-0.06BaTiO(3) ceramics is presented. This piezoelectric transformer, with a multilayered construction in the thickness direction, is 8.3 mm long, 8.3 mm wide, and 2.3 mm thick. It operates in the second thickness extensional vibration mode. For a temperature rise of 20 degrees C, the transformer has an output power of >0.3 W. With a matching load resistance of 10 Omega, its maximum efficiency approaches 81.5%, and the maximum voltage gain is 0.14. It has potential to be used in low voltage power supply units such as low power adapter and other electronic circuits.

Structural and electrochemical analysis of chemically synthesized microcubic architectured lead selenide thin films

NASA Astrophysics Data System (ADS)

Bhat, T. S.; Shinde, A. V.; Devan, R. S.; Teli, A. M.; Ma, Y. R.; Kim, J. H.; Patil, P. S.

2018-01-01

The present work deals with the synthesis of lead selenide (PbSe) thin films by simple and cost-effective chemical bath deposition method with variation in deposition time. The structural, morphological, and electrochemical properties of as-deposited thin films were examined using characterization techniques such as X-ray diffraction spectroscopy (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy. XRD reveals formation of rock salt phase cubic structured PbSe. FE-SEM images show the formation of microcubic structured morphology. The existence of the PbSe is confirmed from the XPS analysis. On the other hand, CV curves show four reaction peaks corresponding to oxidation [PbSe and Pb(OH)2] and reduction (PbO2 and Pb(OH)2) at the surface of PbSe thin films. The PbSe:2 sample deposited for 80 min. shows maximum specific capacitance of 454 ± 5 F g- 1 obtained at 0.25 mA cm- 2 current density. The maximum energy density of 69 Wh kg- 1 was showed by PbSe:2 electrode with a power density of 1077 W kg- 1. Furthermore, electrochemical impedance studies of PbSe:2 thin film show 80 ± 3% cycling stability even after 500 CV cycles. Such results show the importance of microcubic structured PbSe thin film as an anode in supercapacitor devices.

Finite Element Study on Acoustic Energy Harvesting Using Lead-Free Piezoelectric Ceramics

NASA Astrophysics Data System (ADS)

Kumar, Anuruddh; Sharma, Anshul; Kumar, Rajeev; Vaish, Rahul

2018-02-01

In this article, a numerical investigation is performed for ambient acoustic energy harvesting at a low-frequency acoustic signal. A model of a quarter-wavelength resonator with a rectangular cross section is constructed, and piezoelectric-laminated bimorph plates are placed inside the system. Finite element modeling is implemented to numerically formulate the piezoelectric energy harvester. With the application of acoustic pressure at the open end of the resonator, amplified acoustic pressure inside the tube vibrates the piezolaminated bimorphs inside the tube, thus generating electric potential on the piezoelectric layers. To generate higher voltage and power in the acoustic harvester, multiple piezolaminated plates are positioned inside the resonator. The lead-free piezoelectric material K0.475Na0.475Li0.05 (Nb0.92Ta0.05Sb0.03)O3 (KNLNTS) is laminated on the host structure as a layer of piezoelectric material for the acoustic energy harvester. With the application of an acoustic sound pressure of 1 dB at the opening of the tube, a maximum output voltage of 16.3 V is measured at the first natural frequency, while the maximum power calculated is 0.033 mW. Maximum voltage is obtained when five piezoelectric bimorphs are place inside the resonator. At the second natural frequency, the maximum voltage measured is 8.40 V, obtained when eight piezoelectric bimorphs are placed inside the resonator, and the maximum power calculated is 0.020 mW.

Non-trivial behavior of the low temperature maximum of dielectric constant and location of the end critical point in Na0.5Bi0.5TiO3-0.06BaTiO3 lead free relaxor ferroelectrics crystals detected by acoustic emission

NASA Astrophysics Data System (ADS)

Dul'kin, Evgeniy; Tiagunova, Jenia; Mojaev, Evgeny; Roth, Michael

2018-01-01

[001] lead free relaxor ferroelectrics crystals of Na0.5Bi0.5TiO3-0.06BaTiO3 were studied by means of dielectric and acoustic emission methods in the temperature range of 25-240 °C and under a dc bias electric field up to 0.4 kV/cm. A temperature maximum of the dielectric constant was found near 170 °C, as well as the acoustic emission bursts pointed out to both the depolarization temperature near 120 °C and the temperature, corresponding to the maximum of dielectric constant, near 170 °C. While the depolarization temperature increased linearly, the temperature of the dielectric constant maximum was shown to exhibit a V-shape behavior under an electric field: it initially decreases, reaches a sharp minimum at some small threshold electric field of 0.15 kV/cm, and then starts to increase similar to the Curie temperature of the normal ferroelectrics, as the field enhances. Acoustic emission bursts, accompanying the depolarization temperature, weakened with the enhancing field, whereas the ones accompanying the temperature of the dielectric constant maximum exhibited two maxima: near 0.1 kV/cm and near 0.3 kV/cm. The meaning of these two acoustic emission maxima is discussed.

Comparison of different strategies for using fossil calibrations to generate the time prior in Bayesian molecular clock dating.

PubMed

Barba-Montoya, Jose; Dos Reis, Mario; Yang, Ziheng

2017-09-01

Fossil calibrations are the utmost source of information for resolving the distances between molecular sequences into estimates of absolute times and absolute rates in molecular clock dating analysis. The quality of calibrations is thus expected to have a major impact on divergence time estimates even if a huge amount of molecular data is available. In Bayesian molecular clock dating, fossil calibration information is incorporated in the analysis through the prior on divergence times (the time prior). Here, we evaluate three strategies for converting fossil calibrations (in the form of minimum- and maximum-age bounds) into the prior on times, which differ according to whether they borrow information from the maximum age of ancestral nodes and minimum age of descendent nodes to form constraints for any given node on the phylogeny. We study a simple example that is analytically tractable, and analyze two real datasets (one of 10 primate species and another of 48 seed plant species) using three Bayesian dating programs: MCMCTree, MrBayes and BEAST2. We examine how different calibration strategies, the birth-death process, and automatic truncation (to enforce the constraint that ancestral nodes are older than descendent nodes) interact to determine the time prior. In general, truncation has a great impact on calibrations so that the effective priors on the calibration node ages after the truncation can be very different from the user-specified calibration densities. The different strategies for generating the effective prior also had considerable impact, leading to very different marginal effective priors. Arbitrary parameters used to implement minimum-bound calibrations were found to have a strong impact upon the prior and posterior of the divergence times. Our results highlight the importance of inspecting the joint time prior used by the dating program before any Bayesian dating analysis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Analysis of the dynamics of renal vascular resistance and urine flow rate in the cat following electrical stimulation of the renal nerves.

PubMed

Celler, B G; Stella, A; Golin, R; Zanchetti, A

1996-08-01

In ten sino aortic denervated, vagotomized and aneasthetized cats, renal efferent nerves were stimulated for 30 s with trains of constant current pulses at frequencies in the range 5-30 Hz. The arterial pressure, heart rate, urine flow rate (electronic drop counter) and renal blood flow (electromagnetic technique) were recorded. Subsequent computer processing gave the true means of renal artery pressure (MRAP) and renal blood flow (MRBF) and hence the renal vascular resistance (MRVR), over each cardiac cycle. Recovery of MRVR after the end of stimulation exhibited two distinct time constants. The fast component had a time constant of 2.03 +/- 0.26 s and represented 60.2 +/- 1.71% of the recovery. The time constant of the slower component was 14.1 +/- 1.9 s and represented 36.0 +/- 1.6% of the recovery. The relationship between MRVR and stimulus frequency was sigmoidal with maximum sensitivity at stimulus frequencies of 12.6 +/- 0.76 Hz. Changes in urine flow rate, in contrast, followed a hyperbolic function with maximum response sensitivity occurring at very low stimulus frequencies. Changes in urine flow rate were 50% complete at stimulus frequencies of 5 Hz. Identification of two distinct components in the relaxation phase of renal vascular resistance leads to a reasonable hypothesis that 60% of total renal vascular resistance may lie proximal to the glomerulus, whereas 36% may be accounted for by the efferent arterioles.

The Significance of the Record Length in Flood Frequency Analysis

NASA Astrophysics Data System (ADS)

Senarath, S. U.

2013-12-01

Of all of the potential natural hazards, flood is the most costly in many regions of the world. For example, floods cause over a third of Europe's average annual catastrophe losses and affect about two thirds of the people impacted by natural catastrophes. Increased attention is being paid to determining flow estimates associated with pre-specified return periods so that flood-prone areas can be adequately protected against floods of particular magnitudes or return periods. Flood frequency analysis, which is conducted by using an appropriate probability density function that fits the observed annual maximum flow data, is frequently used for obtaining these flow estimates. Consequently, flood frequency analysis plays an integral role in determining the flood risk in flood prone watersheds. A long annual maximum flow record is vital for obtaining accurate estimates of discharges associated with high return period flows. However, in many areas of the world, flood frequency analysis is conducted with limited flow data or short annual maximum flow records. These inevitably lead to flow estimates that are subject to error. This is especially the case with high return period flow estimates. In this study, several statistical techniques are used to identify errors caused by short annual maximum flow records. The flow estimates used in the error analysis are obtained by fitting a log-Pearson III distribution to the flood time-series. These errors can then be used to better evaluate the return period flows in data limited streams. The study findings, therefore, have important implications for hydrologists, water resources engineers and floodplain managers.

Universal behavior in ideal slip

NASA Technical Reports Server (NTRS)

Bozzolo, Guillermo; Ferrante, John; Smith, John R.

1991-01-01

The slip energies and stresses are computed for defect-free crystals of Ni, Cu, Ag, and Al using the many-atom approach. A simple analytical expression for the slip energies is obtained, leading to a universal form for slip, with the energy scaled by the surface energy and displacement scaled by the lattice constant. Maximum stresses are found to be somewhat larger than but comparable with experimentally determined maximum whisker strengths.

Analysis of dispatching rules in a stochastic dynamic job shop manufacturing system with sequence-dependent setup times

NASA Astrophysics Data System (ADS)

Sharma, Pankaj; Jain, Ajai

2014-12-01

Stochastic dynamic job shop scheduling problem with consideration of sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of nine dispatching rules in such shop from makespan, mean flow time, maximum flow time, mean tardiness, maximum tardiness, number of tardy jobs, total setups and mean setup time performance measures viewpoint. A discrete event simulation model of a stochastic dynamic job shop manufacturing system is developed for investigation purpose. Nine dispatching rules identified from literature are incorporated in the simulation model. The simulation experiments are conducted under due date tightness factor of 3, shop utilization percentage of 90% and setup times less than processing times. Results indicate that shortest setup time (SIMSET) rule provides the best performance for mean flow time and number of tardy jobs measures. The job with similar setup and modified earliest due date (JMEDD) rule provides the best performance for makespan, maximum flow time, mean tardiness, maximum tardiness, total setups and mean setup time measures.

Environment in pediatric wards: light, sound, and temperature.

PubMed

Oliveira, Lia; Gomes, Cláudia; Bacelar Nicolau, Leonor; Ferreira, Luís; Ferreira, Rosário

2015-09-01

The mutual relationship between sleep and disease is well known, becoming more relevant whenever the disease leads to hospitalization. We intend to describe patterns of environmental factors of some pediatric wards, and to verify if these are in line with those recommended. As a secondary aim, we characterize sleep quality during hospitalization. Five pediatric wards of a tertiary-level hospital were included. Light, sound, and temperature were measured and assessed through descriptive statistics. The following recommended values were considered: maximum light 100 Lux, maximum sound 45 dB, and optimal temperature 20-24 °C. A questionnaire was prepared to assess children's sleep, and it was completed by a caregiver. Light values were within the desirable limits for 86% of evaluated time. In all wards, the intensity of sound was much higher than desirable, being above 45 dB during 85% of evaluated time. The temperature was above 24 °C during 78% of total time. Based on 34 answered questionnaires (out of 50 distributed), almost half of the respondents believe that sleep quality and restlessness are worse at the hospital. Most children slept for a longer time at home. Eighteen children awoke more times at the hospital, and those awakenings were mostly attributed to noise. The sound and temperature were higher than recommended. The different values between these wards may be due to different levels of care, but this shows that there are no standard rules on this matter. A worse quality and shorter duration of sleep at hospital were reported. Comprehensive studies are necessary to evaluate the impact of environmental factors on disease recovery. Copyright © 2015 Elsevier B.V. All rights reserved.

78 FR 54835 - Air Quality Implementation Plan; Alabama; Attainment Plan for the Troy Area 2008 Lead...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-06

... input options commensurate with the Regulatory Modeling Guidance. Perform current and post control.... Table 2--Post-Control Modeling Results \\4\\ Sanders lead facility Max 3-mth Background Total Year maximum...\\ (Facility MET data). The post-control analysis resulted in a predicted impact of 0.15 [mu]g/m\\3\\ (NWS MET...

Charge Efficiency Tests of Lead/Acid Batteries

NASA Technical Reports Server (NTRS)

Rowlette, J. J.

1984-01-01

Current, voltage, and gas evolution measured during charge/discharge cycles. Series of standarized tests for evaluating charging efficiency of lead/acid storage batteries described in report. Purpose of tests to provide information for design of battery charger that allows maximum recharge efficiency for electric-vehicle batteries consistent with other operating parameters, such as range, water loss, and cycle life.

Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes.

PubMed

Kawada, Shinichiro; Hayashi, Hiroyuki; Ishii, Hideki; Kimura, Masahiko; Ando, Akira; Omiya, Suetake; Kubodera, Noriyuki

2015-11-03

Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain ( S max / E max ) of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where S max denotes the maximum strain and E max denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed.

Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes

PubMed Central

Kawada, Shinichiro; Hayashi, Hiroyuki; Ishii, Hideki; Kimura, Masahiko; Ando, Akira; Omiya, Suetake; Kubodera, Noriyuki

2015-01-01

Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain (Smax/Emax) of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where Smax denotes the maximum strain and Emax denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed. PMID:28793646

[Induction of glutathione and activation of immune functions by low-dose, whole-body irradiation with gamma-rays].

PubMed

Kojima, Shuji

2006-10-01

We first examined the relation between the induction of glutathione and immune functions in mice after low-dose gamma-ray irradiation. Thereafter, inhibition of tumor growth by radiation was confirmed in Ehrlich solid tumor (EST)-bearing mice. The total glutathione level of the splenocytes transiently increased soon after irradiation and reached a maximum at around 4 h postirradiation. Thereafter, the level reverted to the 0 h value by 24 h postirradiation. A significantly high splenocyte proliferative response was also recognized 4 h postirradiation. Natural killer (NK) activity was also increased significantly in a similar manner. The time at which the response reached the maximum coincided well with that of maximum total glutathione levels of the splenocytes in the gamma-ray-irradiated mice. Reduced glutathione exogenously added to splenocytes obtained from normal mice enhanced the proliferative response and NK activity in a dose-dependent manner. The inhibitory effects of radiation on tumor growth was then examined in EST-bearing mice. Repeated low-dose irradiation (0.5 Gy, four times, before and within an early time after inoculation) significantly delayed the tumor growth. Finally, the effect of single low-dose (0.5 Gy), whole-body gamma-ray irradiation on immune balance was examined to elucidate the mechanism underlying the antitumor immunity. The percentage of B cells in blood lymphocytes was selectively decreased after radiation, concomitant with an increase in that of the helper T cell population. The IFN-gamma level in splenocyte culture prepared from EST-bearing mice was significantly increased 48 h after radiation, although the level of IL-4 was unchanged. IL-12 secretion from macrophages was also enhanced by radiation. These results suggest that low-dose gamma-rays induce Th1 polarization and enhance the activities of tumoricidal effector cells, leading to an inhibition of tumor growth.

Stress-strain state of reinforced bimodulus beam on an elastic foundation

NASA Astrophysics Data System (ADS)

Beskopylny, A. N.; Kadomtseva, E. E.; Strelnikov, G. P.; Berdnik, Y. A.

2017-10-01

The paper provides the calculation theory of an arbitrary supported and arbitrary loaded reinforced beam filled with bimodulus material. The formulas determining normal stresses, bending moments, shear forces, rotation angles and a deflection of a rectangular crosssection beam reinforced with any number of bars aligned parallel to the beam axis have been obtained. The numerical study has been carried out to investigate an influence of a modulus of subgrade reaction on values of maximum normal stresses, maximum bending moments and a maximum deflection of a hinged supported beam loaded with a point force or uniform distributed load. The estimation is based on the method of initial parameters for a beam on elastic foundation and the Bubnov-Galerkin method. Values of maximum deflections, maximum bending moments and maximum stresses obtained by these methods coincide. The numerical studies show that taking into consideration the bimodulus of material leads to the necessity to calculate the strength analysis of both tensile stresses and compressive stresses.

Pulse-Driven Capacitive Lead Ion Detection with Reduced Graphene Oxide Field-Effect Transistor Integrated with an Analyzing Device for Rapid Water Quality Monitoring.

PubMed

Maity, Arnab; Sui, Xiaoyu; Tarman, Chad R; Pu, Haihui; Chang, Jingbo; Zhou, Guihua; Ren, Ren; Mao, Shun; Chen, Junhong

2017-11-22

Rapid and real-time detection of heavy metals in water with a portable microsystem is a growing demand in the field of environmental monitoring, food safety, and future cyber-physical infrastructure. Here, we report a novel ultrasensitive pulse-driven capacitance-based lead ion sensor using self-assembled graphene oxide (GO) monolayer deposition strategy to recognize the heavy metal ions in water. The overall field-effect transistor (FET) structure consists of a thermally reduced graphene oxide (rGO) channel with a thin layer of Al 2 O 3 passivation as a top gate combined with sputtered gold nanoparticles that link with the glutathione (GSH) probe to attract Pb 2+ ions in water. Using a preprogrammed microcontroller, chemo-capacitance based detection of lead ions has been demonstrated with this FET sensor. With a rapid response (∼1-2 s) and negligible signal drift, a limit of detection (LOD) < 1 ppb and excellent selectivity (with a sensitivity to lead ions 1 order of magnitude higher than that of interfering ions) can be achieved for Pb 2+ measurements. The overall assay time (∼10 s) for background water stabilization followed by lead ion testing and calculation is much shorter than common FET resistance/current measurements (∼minutes) and other conventional methods, such as optical and inductively coupled plasma methods (∼hours). An approximate linear operational range (5-20 ppb) around 15 ppb (the maximum contaminant limit by US Environmental Protection Agency (EPA) for lead in drinking water) makes it especially suitable for drinking water quality monitoring. The validity of the pulse method is confirmed by quantifying Pb 2+ in various real water samples such as tap, lake, and river water with an accuracy ∼75%. This capacitance measurement strategy is promising and can be readily extended to various FET-based sensor devices for other targets.

Depolarization changes during acute myocardial ischemia by evaluation of QRS slopes: standard lead and vectorial approach.

PubMed

Romero, Daniel; Ringborn, Michael; Laguna, Pablo; Pahlm, Olle; Pueyo, Esther

2011-01-01

Diagnosis and risk stratification of patients with acute coronary syndromes can be improved by adding information from the depolarization phase (QRS complex) to the conventionally used ST-T segment changes. In this study, ischemia-induced changes in the main three slopes of the QRS complex, upward ( ℑ(US)) and downward ( ℑ(DS) ) slopes of the R wave as well as the upward ( ℑ(TS)) slope of the terminal S wave, were evaluated as to represent a robust measure of pathological changes within the depolarization phase. From ECG recordings both in a resting state (control recordings) and during percutaneous coronary intervention (PCI)-induced transmural ischemia, we developed a method for quantification of ℑ(US), ℑ(DS), and ℑ(TS) that incorporates dynamic ECG normalization so as to improve the sensitivity in the detection of ischemia-induced changes. The same method was also applied on leads obtained by projection of QRS loops onto their dominant directions. We show that ℑ(US), ℑ(DS), and ℑ(TS) present high stability in the resting state, thus providing a stable reference for ischemia characterization. Maximum relative factors of change ( ℜ(ℑ)) during PCI were found in leads derived from the QRS loop, reaching 10.5 and 13.7 times their normal variations in the control for ℑ(US) and ℑ(DS), respectively. For standard leads, the relative factors of change were 6.01 and 9.31. The ℑ(TS) index presented a similar behavior to that of ℑ(DS). The timing for the occurrence of significant changes in ℑ(US) and ℑ(DS) varied with lead, ranging from 30 s to 2 min after initiation of coronary occlusion. In the present ischemia model, relative ℑ(DS) changes were smaller than ST changes in most leads, however with only modest correlation between the two indices, suggesting they present different information about the ischemic process. We conclude that QRS slopes offer a robust tool for evaluating depolarization changes during myocardial ischemia.

The global distribution of magnitude 9 earthquakes

NASA Astrophysics Data System (ADS)

McCaffrey, R.

2011-12-01

The 2011 Tohoku M9 earthquake once again caught some in the earthquake community by surprise. The expectation of these massive quakes has been driven in the past by the over-reliance on our short, incomplete history of earthquakes and causal relationships derived from it. The logic applied is that if a great earthquake has not happened in the past, that we know of, one cannot happen in the future. Using the ~100-year global earthquake history, seismologists have promoted relationships between maximum earthquake sizes and other properties of subduction zones, leading to the notion that some subduction zones, like the Japan Trench, would never produce a magnitude ~9 event. The 2004 Andaman Mw = 9.2 earthquake, that occurred where there is slow subduction of old crust and a history of only moderate-sized earthquakes, seriously undermined such ideas. Given multi-century return times of the greatest earthquakes, ignorance of those return times and our very limited observation span, I suggest that we cannot yet make such determinations. Alternatively, using the length of a subduction zone that is available for slip as the predominant factor in determining maximum earthquake size, we cannot rule out that any subduction zone of a few hundred kilometers or more in length may be capable of producing a magnitude 9 or larger earthquake. Based on this method, the expected maximum size for the Japan Trench was 9.0 (McCaffrey, Geology, p. 263, 2008). The same approach portends a M > 9 for Java, with twice the population density as Honshu and much lower building standards. The Java Trench, and others where old crust subducts (Hikurangi, Marianas, Tonga, Kermadec), require increased awareness of the possibility for a great earthquake.

Thermal acclimation to cold alters myosin content and contractile properties of rainbow smelt, Osmerus mordax, red muscle.

PubMed

Coughlin, David J; Shiels, Lisa P; Nuthakki, Seshuvardhan; Shuman, Jacie L

2016-06-01

Rainbow smelt (Osmerus mordax), a eurythermal fish, live in environments from -1.8 to 20°C, with some populations facing substantial annual variation in environmental temperature. These different temperature regimes pose distinct challenges to locomotion by smelt. Steady swimming performance, red muscle function and muscle myosin content were examined to assess the prediction that cold acclimation by smelt will lead to improved steady swimming performance and that any performance shift will be associated with changes in red muscle function and in its myosin heavy chain composition. Cold acclimated (4°C) smelt had a faster maximum steady swimming speed and swam with a higher tailbeat frequency than warm acclimated (10°C) smelt when tested at the same temperature (10°C). Muscle mechanics experiments demonstrated faster contractile properties in the cold acclimated fish when tested at 10°C. The red muscle of cold acclimated smelt had a shorter twitch times, a shorter relaxation times and a higher maximum shortening velocity. In addition, red muscle from cold acclimated fish displayed reduced thermal sensitivity to cold, maintaining higher force levels at 4°C compared to red muscle from warm acclimated fish. Immunohistochemistry suggests shifts in muscle myosin composition and a decrease in muscle cross-sectional area with cold acclimation. Dot blot analysis confirmed a shift in myosin content. Rainbow smelt do show a significant thermal acclimation response to cold. An examination of published values of maximum muscle shortening velocity in fishes suggests that smelt are particularly well suited to high levels of activity in very cold water. Copyright © 2016 Elsevier Inc. All rights reserved.

Rational and timely haemostatic interventions following cardiac surgery - coagulation factor concentrates or blood bank products.

PubMed

Tang, Mariann; Fenger-Eriksen, Christian; Wierup, Per; Greisen, Jacob; Ingerslev, Jørgen; Hjortdal, Vibeke; Sørensen, Benny

2017-06-01

Cardiac surgery may cause a serious coagulopathy leading to increased risk of bleeding and transfusion demands. Blood bank products are commonly first line haemostatic intervention, but has been associated with hazardous side effect. Coagulation factor concentrates may be a more efficient, predictable, and potentially a safer treatment, although prospective clinical trials are needed to further explore these hypotheses. This study investigated the haemostatic potential of ex vivo supplementation of coagulation factor concentrates versus blood bank products on blood samples drawn from patients undergoing cardiac surgery. 30 adults were prospectively enrolled (mean age=63.9, females=27%). Ex vivo haemostatic interventions (monotherapy or combinations) were performed in whole blood taken immediately after surgery and two hours postoperatively. Fresh-frozen plasma, platelets, cryoprecipitate, fibrinogen concentrate, prothrombin complex concentrate (PCC), and recombinant FVIIa (rFVIIa) were investigated. The haemostatic effect was evaluated using whole blood thromboelastometry parameters, as well as by thrombin generation. Immediately after surgery the compromised maximum clot firmness was corrected by monotherapy with fibrinogen or platelets or combination therapy with fibrinogen. At two hours postoperatively the coagulation profile was further deranged as illustrated by a prolonged clotting time, a reduced maximum velocity and further diminished maximum clot firmness. The thrombin lagtime was progressively prolonged and both peak thrombin and endogenous thrombin potential were compromised. No monotherapy effectively corrected all haemostatic abnormalities. The most effective combinations were: fibrinogen+rFVIIa or fibrinogen+PCC. Blood bank products were not as effective in the correction of the coagulopathy. Coagulation factor concentrates appear to provide a more optimal haemostasis profile following cardiac surgery compared to blood bank products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of load distribution in tooth-implant supported fixed partial dentures by the use of resilient abutment.

PubMed

Glisić, Mirko; Stamenković, Dragoslav; Grbović, Aleksandar; Todorović, Aleksandar; Marković, Aleksa; Trifković, Branka

2016-01-01

Differences between the tooth and implant response to load can lead to many biological and technical implications in the conditions of occlusal forces. The objective of this study was to analyze load distribution in tooth/implant-supported fixed partial dentures with the use of resilient TSA (Titan Shock Absorber, BoneCare GmbH, Augsburg, Germany) abutment and conventional non-resilient abutment using finite element method. This study presents two basic 3D models. For one model a standard non-resilient abutment is used, and on the implant of the second model a resilient TSA abutment is applied. The virtual model contains drawn contours of tooth, mucous membranes, implant, cortical bones and spongiosa, abutment and suprastructure. The experiment used 500 N of vertical force, applied in three different cases of axial load. Calculations of von Mises equivalent stresses of the tooth root and periodontium, implants and peri-implant tissue were made. For the model to which a non-resilient abutment is applied, maximum stress values in all three cases are observed in the cortical part of the bone (maximum stress value of 49.7 MPa). Measurements of stress and deformation in the bone tissue in the model with application of the resilientTSA abutment demonstrated similar distribution; however, these values are many times lower than in the model with non-resilient TSA abutment (maximum stress value of 28.9 MPa). Application of the resilient TSA abutment results in more equal distribution of stress and deformations in the bone tissue under vertical forces. These values are many times lower than in the model with the non-resilient abutment.

Enhanced charge transport and photovoltaic performance of PBDTTT-C-T/PC70BM solar cells via UV-ozone treatment.

PubMed

Adhikary, Prajwal; Venkatesan, Swaminathan; Adhikari, Nirmal; Maharjan, Purna P; Adebanjo, Olusegun; Chen, Jihua; Qiao, Qiquan

2013-10-21

In this work, the electron transport layer of PBDTTT-C-T/PC70BM polymer solar cells were subjected to UV-ozone treatment, leading to improved cell performances from 6.46% to 8.34%. The solar cell efficiency reached a maximum of 8.34% after an optimal 5 minute UV-ozone treatment, and then decreased if treated for a longer time. To the best of our knowledge, the mechanism behind the effects of UV-ozone treatment on the improvement of charge transport and cell performance is not fully understood. We have developed a fundamental understanding of the UV-ozone treatment mechanism, which explains both the enhancements in charge transport and photovoltaic performance at an optimal treatment time, and also the phenomenon whereby further treatment time leads to a drop in cell efficiency. Transient photocurrent measurements indicated that the cell charge transport times were 1370 ns, 770 ns, 832 ns, 867 ns, and 1150 ns for the 0 min, 5 min, 10 min, 15 min, and 20 min UV-ozone treatment times, respectively. Therefore the 5 min UV-ozone treatment time led to the shortest transport time and the most efficient charge transport in the cells. The 5 min UV-ozone treated sample exhibited the highest peak intensity (E2) in the Raman spectra of the treated films, at about 437 cm(-1), indicating that it possessed the best wurtzite phase crystallinity of the ZnO films. Further increasing the UV-ozone treatment time from 5 to 20 min induced the formation of p-type defects (e.g. interstitial oxygen atoms), pushing the ZnO Fermi-level further away from the vacuum level, and decreasing the wurtzite crystallinity.

Effects of intra-aortic balloon pump timing on baroreflex activities in a closed-loop cardiovascular hybrid model.

PubMed

Fresiello, Libera; Khir, Ashraf William; Di Molfetta, Arianna; Kozarski, Maciej; Ferrari, Gianfranco

2013-03-01

Despite 50 years of research to assess the intra-aortic balloon pump (IABP) effects on patients' hemodynamics, some issues related to the effects of this therapy are still not fully understood. One of these issues is the effect of IABP, its inflation timing and duration on peripheral circulation autonomic controls. This work provides a systematic analysis of IABP effects on baroreflex using a cardiovascular hybrid model, which consists of computational and hydraulic submodels. The work also included a baroreflex computational model that was connected to a hydraulic model with a 40-cm(3) balloon. The IABP was operated at different inflation trigger timings (-0.14 to 0.31 s) and inflation durations (0.05-0.45 s), with time of the dicrotic notch being taken as t = 0. Baroreflex-dependent parameters-afferent and efferent pathway activity, heart rate, peripheral resistance, and venous tone-were evaluated at each of the inflation trigger times and durations considered. Balloon early inflation (0.09 s before the dicrotic notch) with inflation duration of 0.25 s generated a maximum net increment of afferent pathway activity of 10%, thus leading to a decrement of efferent sympathetic activity by 15.3% compared with baseline values. These times also resulted in a reduction in peripheral resistance and heart rate by 4 and 4.3% compared with baseline value. We conclude that optimum IABP triggering time results in positive effects on peripheral circulation autonomic controls. Conversely, if the balloon is not properly timed, peripheral resistance and heart rate may even increase, which could lead to detrimental outcomes. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Maximum Range of a Projectile Thrown from Constant-Speed Circular Motion

NASA Astrophysics Data System (ADS)

Poljak, Nikola

2016-11-01

The problem of determining the angle θ at which a point mass launched from ground level with a given speed v0 will reach a maximum distance is a standard exercise in mechanics. There are many possible ways of solving this problem, leading to the well-known answer of θ = π/4, producing a maximum range of D max = v0 2 / g , with g being the free-fall acceleration. Conceptually and calculationally more difficult problems have been suggested to improve student proficiency in projectile motion, with the most famous example being the Tarzan swing problem. The problem of determining the maximum distance of a point mass thrown from constant-speed circular motion is presented and analyzed in detail in this text. The calculational results confirm several conceptually derived conclusions regarding the initial throw position and provide some details on the angles and the way of throwing (underhand or overhand) that produce the maximum throw distance.

Progress Report on Long Hold Time Creep Fatigue of Alloy 617 at 850°C

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

Carroll, Laura Jill

Alloy 617 is the leading candidate material for an intermediate heat exchanger for the very high temperature reactor. To evaluate the behavior of this material in the expected service conditions, strain-controlled cyclic tests that include long hold times up to 240 minutes at maximum tensile strain were conducted at 850°C. In terms of the total number of cycles to failure, the fatigue resistance decreased when a hold time was added at peak tensile strain. Increases in the tensile hold duration degraded the creep-fatigue resistance, at least to the investigated strain controlled hold time of up to 60 minutes at themore » 0.3% strain range and 240 minutes at the 1.0% strain range. The creep-fatigue deformation mode is considered relative to the lack of saturation, or continually decreasing number of cycles to failure with increasing hold times. Additionally, preliminary values from the 850°C creep-fatigue data are calculated for the creep-fatigue damage diagram and have higher values of creep damage than those from tests at 950°C.« less

A Thermostructural Analysis of a Diboride Composite Leading Edge

NASA Technical Reports Server (NTRS)

Kowalski, Tom; Buesking, Kent; Kolodziej, Paul; Bull, Jeff

1996-01-01

In an effort to support the design of zirconium diboride composite leading edges for hypersonic vehicles, a finite element model (FEM) of a prototype leading edge was created and finite element analysis (FEA) was employed to assess its thermal and structural response to aerothermal boundary conditions. Unidirectional material properties for the structural components of the leading edge, a continuous fiber reinforced diboride composite, were computed with COSTAR. These properties agree well with those experimentally measured. To verify the analytical approach taken with COSMOS/M, an independent FEA of one of the leading edge assembly components was also done with COSTAR. Good agreement was obtained between the two codes. Both showed that a unidirectional lay-up had the best margin of safety for a simple loading case. Both located the maximum stress in the same region and ply. The magnitudes agreed within 4 percent. Trajectory based aerothermal heating was then applied to the leading edge assembly FEM created with COSMOS/M to determine steady state temperature response, displacement, stresses, and contact forces due to thermal expansion and thermal strains. Results show that the leading edge stagnation line temperature reached 4700 F. The maximum computed failure index for the laminated composite components peaks at 4.2, and is located at the bolt flange in layer 2 of the side bracket. The temperature gradient in the tip causes a compressive stress of 279 ksi along its width and substantial tensile stresses within its depth.

Design feasibility via ascent optimality for next-generation spacecraft

NASA Astrophysics Data System (ADS)

Miele, A.; Mancuso, S.

This paper deals with the optimization of the ascent trajectories for single-stage-sub-orbit (SSSO), single-stage-to-orbit (SSTO), and two-stage-to-orbit (TSTO) rocket-powered spacecraft. The maximum payload weight problem is studied for different values of the engine specific impulse and spacecraft structural factor. The main conclusions are that: feasibility of SSSO spacecraft is guaranteed for all the parameter combinations considered; feasibility of SSTO spacecraft depends strongly on the parameter combination chosen; not only feasibility of TSTO spacecraft is guaranteed for all the parameter combinations considered, but the TSTO payload is several times the SSTO payload. Improvements in engine specific impulse and spacecraft structural factor are desirable and crucial for SSTO feasibility; indeed, aerodynamic improvements do not yield significant improvements in payload. For SSSO, SSTO, and TSTO spacecraft, simple engineering approximations are developed connecting the maximum payload weight to the engine specific impulse and spacecraft structural factor. With reference to the specific impulse/structural factor domain, these engineering approximations lead to the construction of zero-payload lines separating the feasibility region (positive payload) from the unfeasibility region (negative payload).

One hundred fold increase in current carrying capacity in a carbon nanotube–copper composite

PubMed Central

Subramaniam, Chandramouli; Yamada, Takeo; Kobashi, Kazufumi; Sekiguchi, Atsuko; Futaba, Don N.; Yumura, Motoo; Hata, Kenji

2013-01-01

Increased portability, versatility and ubiquity of electronics devices are a result of their progressive miniaturization, requiring current flow through narrow channels. Present-day devices operate close to the maximum current-carrying-capacity (that is, ampacity) of conductors (such as copper and gold), leading to decreased lifetime and performance, creating demand for new conductors with higher ampacity. Ampacity represents the maximum current-carrying capacity of the object that depends both on the structure and material. Here we report a carbon nanotube–copper composite exhibiting similar conductivity (2.3–4.7 × 105 S cm−1) as copper (5.8 × 105 S cm−1), but with a 100-times higher ampacity (6 × 108 A cm−2). Vacuum experiments demonstrate that carbon nanotubes suppress the primary failure pathways in copper as observed by the increased copper diffusion activation energy (∼2.0 eV) in carbon nanotube–copper composite, explaining its higher ampacity. This is the only material with both high conductivity and high ampacity, making it uniquely suited for applications in microscale electronics and inverters. PMID:23877359

Analysis and design of a genetic circuit for dynamic metabolic engineering.

PubMed

Anesiadis, Nikolaos; Kobayashi, Hideki; Cluett, William R; Mahadevan, Radhakrishnan

2013-08-16

Recent advances in synthetic biology have equipped us with new tools for bioprocess optimization at the genetic level. Previously, we have presented an integrated in silico design for the dynamic control of gene expression based on a density-sensing unit and a genetic toggle switch. In the present paper, analysis of a serine-producing Escherichia coli mutant shows that an instantaneous ON-OFF switch leads to a maximum theoretical productivity improvement of 29.6% compared to the mutant. To further the design, global sensitivity analysis is applied here to a mathematical model of serine production in E. coli coupled with a genetic circuit. The model of the quorum sensing and the toggle switch involves 13 parameters of which 3 are identified as having a significant effect on serine concentration. Simulations conducted in this reduced parameter space further identified the optimal ranges for these 3 key parameters to achieve productivity values close to the maximum theoretical values. This analysis can now be used to guide the experimental implementation of a dynamic metabolic engineering strategy and reduce the time required to design the genetic circuit components.

Optimal Ge/SiGe nanofin geometries for hole mobility enhancement: Technology limit from atomic simulations

NASA Astrophysics Data System (ADS)

Vedula, Ravi Pramod; Mehrotra, Saumitra; Kubis, Tillmann; Povolotskyi, Michael; Klimeck, Gerhard; Strachan, Alejandro

2015-05-01

We use first principles simulations to engineer Ge nanofins for maximum hole mobility by controlling strain tri-axially through nano-patterning. Large-scale molecular dynamics predict fully relaxed, atomic structures for experimentally achievable nanofins, and orthogonal tight binding is used to obtain the corresponding electronic structure. Hole transport properties are then obtained via a linearized Boltzmann formalism. This approach explicitly accounts for free surfaces and associated strain relaxation as well as strain gradients which are critical for quantitative predictions in nanoscale structures. We show that the transverse strain relaxation resulting from the reduction in the aspect ratio of the fins leads to a significant enhancement in phonon limited hole mobility (7× over unstrained, bulk Ge, and 3.5× over biaxially strained Ge). Maximum enhancement is achieved by reducing the width to be approximately 1.5 times the height and further reduction in width does not result in additional gains. These results indicate significant room for improvement over current-generation Ge nanofins, provide geometrical guidelines to design optimized geometries and insight into the physics behind the significant mobility enhancement.

Principles and applications of laser-induced liquid-phase jet-chemical etching

NASA Astrophysics Data System (ADS)

Stephen, Andreas; Metev, Simeon; Vollertsen, Frank

2003-11-01

In this treatment method laser radiation, which is guided from a coaxially expanding liquid jet-stream, locally initiates a thermochemical etching reaction on a metal surface, which leads to selective material removal at high resolution and quality of the treated surface as well as low thermal influence on the workpiece. Electrochemical investigations were performed under focused laser irradiation using a cw-Nd:YAG laser with a maximum power of 15 W and a simultaneous impact of the liquid jet-stream consisting of phosphoric acid with a maximum flow rate of 20 m/s. The time resolved measurements of the electrical potential difference against an electrochemical reference electrode were correlated with the specific processing parameters and corresponding etch rates to identify processing conditions for temporally stable and enhanced chemical etching reactions. Applications of laser-induced liquid-phase jet-chemical etching in the field of sensor technology, micromechanics and micrmoulding technology are presented. This includes the microstructuring of thin film systems, cutting of foils of shape memory alloys or the generation of structures with defined shape in bulk material.

One hundred fold increase in current carrying capacity in a carbon nanotube-copper composite

NASA Astrophysics Data System (ADS)

Subramaniam, Chandramouli; Yamada, Takeo; Kobashi, Kazufumi; Sekiguchi, Atsuko; Futaba, Don N.; Yumura, Motoo; Hata, Kenji

2013-07-01

Increased portability, versatility and ubiquity of electronics devices are a result of their progressive miniaturization, requiring current flow through narrow channels. Present-day devices operate close to the maximum current-carrying-capacity (that is, ampacity) of conductors (such as copper and gold), leading to decreased lifetime and performance, creating demand for new conductors with higher ampacity. Ampacity represents the maximum current-carrying capacity of the object that depends both on the structure and material. Here we report a carbon nanotube-copper composite exhibiting similar conductivity (2.3-4.7 × 105Scm-1) as copper (5.8 × 105Scm-1), but with a 100-times higher ampacity (6 × 108Acm-2). Vacuum experiments demonstrate that carbon nanotubes suppress the primary failure pathways in copper as observed by the increased copper diffusion activation energy (~2.0eV) in carbon nanotube-copper composite, explaining its higher ampacity. This is the only material with both high conductivity and high ampacity, making it uniquely suited for applications in microscale electronics and inverters.

Automated Classification of Radiology Reports for Acute Lung Injury: Comparison of Keyword and Machine Learning Based Natural Language Processing Approaches.

PubMed

Solti, Imre; Cooke, Colin R; Xia, Fei; Wurfel, Mark M

2009-11-01

This paper compares the performance of keyword and machine learning-based chest x-ray report classification for Acute Lung Injury (ALI). ALI mortality is approximately 30 percent. High mortality is, in part, a consequence of delayed manual chest x-ray classification. An automated system could reduce the time to recognize ALI and lead to reductions in mortality. For our study, 96 and 857 chest x-ray reports in two corpora were labeled by domain experts for ALI. We developed a keyword and a Maximum Entropy-based classification system. Word unigram and character n-grams provided the features for the machine learning system. The Maximum Entropy algorithm with character 6-gram achieved the highest performance (Recall=0.91, Precision=0.90 and F-measure=0.91) on the 857-report corpus. This study has shown that for the classification of ALI chest x-ray reports, the machine learning approach is superior to the keyword based system and achieves comparable results to highest performing physician annotators.

Automated Classification of Radiology Reports for Acute Lung Injury: Comparison of Keyword and Machine Learning Based Natural Language Processing Approaches

PubMed Central

Solti, Imre; Cooke, Colin R.; Xia, Fei; Wurfel, Mark M.

2010-01-01

This paper compares the performance of keyword and machine learning-based chest x-ray report classification for Acute Lung Injury (ALI). ALI mortality is approximately 30 percent. High mortality is, in part, a consequence of delayed manual chest x-ray classification. An automated system could reduce the time to recognize ALI and lead to reductions in mortality. For our study, 96 and 857 chest x-ray reports in two corpora were labeled by domain experts for ALI. We developed a keyword and a Maximum Entropy-based classification system. Word unigram and character n-grams provided the features for the machine learning system. The Maximum Entropy algorithm with character 6-gram achieved the highest performance (Recall=0.91, Precision=0.90 and F-measure=0.91) on the 857-report corpus. This study has shown that for the classification of ALI chest x-ray reports, the machine learning approach is superior to the keyword based system and achieves comparable results to highest performing physician annotators. PMID:21152268

Enhanced energy harvesting in commercial ferroelectric materials

NASA Astrophysics Data System (ADS)

Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

2014-04-01

Ferroelectric materials are used in a number of applications ranging from simple sensors and actuators to ferroelectric random access memories (FRAMs), transducers, health monitoring system and microelectronics. The multiphysical coupling ability possessed by these materials has been established to be useful for energy harvesting applications. However, conventional energy harvesting techniques employing ferroelectric materials possess low energy density. This has prevented the successful commercialization of ferroelectric based energy harvesting systems. In this context, the present study aims at proposing a novel approach for enhanced energy harvesting using commercially available ferroelectric materials. This technique was simulated to be used for two commercially available piezoelectric materials namely PKI-552 and APCI-840, soft and hard lead-zirconate-titanate (PZT) pervoskite ceramics, respectively. It was observed that a maximum energy density of 348 kJm-3cycle-1 can be obtained for cycle parameters of (0-1 ton compressive stress and 1-25 kV.cm-1 electric field) using APCI-840. The reported energy density is several hundred times larger than the maximum energy density reported in the literature for vibration harvesting systems.

Room temperature synthesis and optical studies on Ag and Au mixed nanocomposite polyvinylpyrrolidone polymer films.

PubMed

Udayabhaskar, R; Mangalaraja, R V; Manikandan, D; Arjunan, V; Karthikeyan, B

2012-12-01

Optical properties of silver, gold and bimetallic (Au:Ag) nanocomposite polymer films which are prepared by chemical method have been reported. The experimental data was correlated with the theoretical calculations using Mie theory. We adopt small change in the theoretical calculations of bimetallic/mixed particle nanocomposite and the theory agrees well with the experimental data. Polyvinylpyrrolidone (PVP) was used as reducing and capping agent. Fourier transform infrared spectroscopy (FTIR) study reveals the presence of different functional groups, the possible mechanism that leads to the formation of nanoparticles by using PVP alone as reducing agent. Optical absorption spectra of Ag and Au nanocomposite polymers show a surface plasmon resonance (SPR) band around 430 and 532 nm, respectively. Thermal annealing effect on the prepared samples at 60 °C for different time durations result in shift of SPR band maximum and varies the full width at half maximum (FWHM). Absorption spectra of Au:Ag bimetallic films show bands at 412 and 547 nm confirms the presence of Ag and Au nanoparticles in the composite. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of Pb2+ ions on ilmenite flotation and adsorption of benzohydroxamic acid as a collector

NASA Astrophysics Data System (ADS)

Xu, Longhua; Tian, Jia; Wu, Houqin; Lu, Zhongyuan; Yang, Yaohui; Sun, Wei; Hu, Yuehua

2017-12-01

The effects of Pb2+ ions on ilmenite flotation and adsorption of benzohydroxamic acid (BHA) as a collector were investigated using microflotation tests, zeta potential measurements, adsorption analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The microflotation results indicate that the addition of Pb2+ significantly improves the recovery of ilmenite using BHA as a collector. A maximum recovery of 88.46% is obtained at pH 8.12 in the presence of Pb2+; a maximum recovery of 45% is obtained at the same pH using BHA alone. At pHs below 8.0, lead nitrate are mainly present in the solution as Pb2+ and PbOH+, while at pHs above 8.0, the predominant components are Pb(OH)2(s) and Pb(OH)3-. The adsorption of these lead species influences the zeta potential of ilmenite and the number of activated sites on the ilmenite surface. FTIR and XPS analyses reveal that lead species and BHA react with the metal sites on the ilmenite surface. The lead species in solution are either adsorbed onto the ilmenite surface, which increases the surface activity of ilmenite, or react with BHA in solution to form complexes of lead and BHA.

Feasibility of Administering High-Dose 131I-MIBG Therapy to Children with High-Risk Neuroblastoma without Lead-Lined Rooms

PubMed Central

Chu, Bae P.; Horan, Christopher; Basu, Ellen; Dauer, Lawrence; Williamson, Matthew; Carrasquillo, Jorge A.; Pandit-Taskar, Neeta; Modak, Shakeel

2015-01-01

Background Although 131I-metaiodobenzylguanidine therapy (131I-MIBG) is increasingly used for children with high-risk neuroblastoma, a paucity of lead-lined rooms limits its wider use. We implemented radiation safety procedures to comply with New York City Department of Health and Mental Hygiene regulations for therapeutic radioisotopes and administered 131I-MIBG using rolling lead shields. Procedure Patients received 0.67GBq (18mCi)/kg/dose 131I-MIBG on an IRB-approved protocol (NCT00107289). Radiation safety procedures included private room with installation of rolling lead shields to maintain area dose rates ≤0.02mSv/h outside the room, patient isolation until dose rate <0.07mSv/h at 1m and retention of a urinary catheter with collection of urine in lead boxes. Parents were permitted in the patient’s room behind lead shields, trained in radiation safety principles and given real-time radiation monitors. Results Records on 16 131I-MIBG infusions among 10 patients (age 2–11 years) were reviewed. Mean ± standard deviation 131I-MIBG administered was 17.67±11.14 (range: 6.11–40.59) GBq. Mean maximum dose rates outside treatment rooms were 0.013±0.008 mSv/hr. Median time-to-discharge was 3 days post-131I-MIBG. Exposure of medical staff and parents was below regulatory limits. Cumulative whole-body dose received by the physician, nurse and radiation safety officer during treatment was 0.098±0.058, 0.056±0.045, 0.055±0.050 mSv respectively. Cumulative exposure to parents was 0.978±0.579mSv. Estimated annual radiation exposure for inpatient nurses was 0.096±0.034mSv/nurse. Thyroid bioassay scans on all medical personnel were

Cadmium, lead, tin, total mercury, and methylmercury in canned tuna commercialised in São Paulo, Brazil.

PubMed

de Paiva, Esther Lima; Morgano, Marcelo Antonio; Milani, Raquel Fernanda

2017-09-01

The objective of this work was to determine levels of inorganic contaminants in 30 samples of five commercial brands of canned tuna, acquired on the local market in Campinas, São Paulo, Brazil, in the year of 2015. Total mercury and methylmercury (MeHg+) were determined by atomic absorption with thermal decomposition and amalgamation; and cadmium, lead, and tin were determined by inductively coupled plasma optical emission spectrometry. Results indicated that 20% of the tuna samples surpassed limits determined by the Brazilian and European Commission legislation for cadmium; for lead, the maximum value found was 59 µg kg -1 and tin was not detected in any samples. The maximum values found for total Hg and MeHg+ were 261 and 258 µg kg -1 , respectively. As from the results obtained, it was estimated that the consumption of four cans per week (540 g) of tuna canned in water could surpass the provisional tolerable monthly intake for MeHg + by 100%.

Assessment of contamination of soil due to heavy metals around coal fired thermal power plants at Singrauli region of India.

PubMed

Agrawal, Prashant; Mittal, Anugya; Prakash, Rajiv; Kumar, Manoj; Singh, T B; Tripathi, S K

2010-08-01

In the present study, an attempt was made to measure contamination of soil around four large coal-based Thermal Power Plants. The concentration of Cadmium, Lead, Arsenic and Nickel was estimated in all four directions from Thermal Power Plants. The soil in the study area was found to be contaminated to varying degrees from coal combustion byproducts. The soil drawn from various selected sites in each direction was largely contaminated by metals, predominantly higher within 2-4 km distance from Thermal Power Plant. Within 2-4 km, the mean maximum concentration of Cadmium, Lead, Arsenic and Nickel was 0.69, 13.69, 17.76, and 3.51 mg/kg, respectively. It was also observed that concentration was maximum in the prevalent wind direction. The concentration of Cadmium, Lead, Arsenic and Nickel was highest 0.69, 13.23, 17.29 and 3.56 mg/kg, respectively in west direction where wind was prevalent.

Burial, thermal, and petroleum generation history of the Upper Cretaceous Steele Member of the Cody Shale (Shannon Sandstone Bed Horizon), Powder River Basin, Wyoming (Chapter A). Bulletin

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

Nuccio, V.F.

The purposes of the study are to (1) present burial histories representative of the northwestern and southwestern parts of the Powder River Basin (south of lat 45 N.), (2) show the maximum level of thermal maturity for the Steele Member and its Shannon Sandstone Bed, and (3) show the source-rock potential and timing of petroleum generation for the Steele. It is hoped that data presented in the study will also lead to a better understanding of the burial and temperature history of the Shannon Sandstone Bed, an understanding crucial for diagenetic studies, fluid-flow modeling, and reservoir-rock characterization.

Assessment of eye lens doses for workers during interventional radiology procedures.

PubMed

Urboniene, A; Sadzeviciene, E; Ziliukas, J

2015-07-01

The assessment of eye lens doses for workers during interventional radiology (IR) procedures was performed using a new eye lens dosemeter. In parallel, the results of routine individual monitoring were analysed and compared with the results obtained from measurements with a new eye lens dosemeter. The eye lens doses were assessed using Hp(3) measured at the level of the eyes and were compared with Hp(10) measured with the whole-body dosemeter above the lead collar. The information about use of protective measures, the number of performed interventional procedures per month and their fluoroscopy time was also collected. The assessment of doses to the lens of the eye was done for 50 IR workers at 9 Lithuanian hospitals for the period of 2012-2013. If the use of lead glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A model for Entropy Production, Entropy Decrease and Action Minimization in Self-Organization

NASA Astrophysics Data System (ADS)

Georgiev, Georgi; Chatterjee, Atanu; Vu, Thanh; Iannacchione, Germano

In self-organization energy gradients across complex systems lead to change in the structure of systems, decreasing their internal entropy to ensure the most efficient energy transport and therefore maximum entropy production in the surroundings. This approach stems from fundamental variational principles in physics, such as the principle of least action. It is coupled to the total energy flowing through a system, which leads to increase the action efficiency. We compare energy transport through a fluid cell which has random motion of its molecules, and a cell which can form convection cells. We examine the signs of change of entropy, and the action needed for the motion inside those systems. The system in which convective motion occurs, reduces the time for energy transmission, compared to random motion. For more complex systems, those convection cells form a network of transport channels, for the purpose of obeying the equations of motion in this geometry. Those transport networks are an essential feature of complex systems in biology, ecology, economy and society.

Peracetic acid oxidation as an alternative pre-treatment for the anaerobic digestion of waste activated sludge.

PubMed

Appels, Lise; Van Assche, Ado; Willems, Kris; Degrève, Jan; Van Impe, Jan; Dewil, Raf

2011-03-01

Anaerobic digestion is generally considered to be an economic and environmentally friendly technology for treating waste activated sludge, but has some limitations, such as the time it takes for the sludge to be digested and also the ineffectiveness of degrading the solids. Various pre-treatment technologies have been suggested to overcome these limitations and to improve the biogas production rate by enhancing the hydrolysis of organic matter. This paper studies the use of peracetic acid for disintegrating sludge as a pre-treatment of anaerobic digestion. It has been proved that this treatment effectively leads to a solubilisation of organic material. A maximum increase in biogas production by 21% is achieved. High dosages of PAA lead to a decrease in biogas production. This is due to the inhibition of the anaerobic micro-organisms by the high VFA-concentrations. The evolution of the various VFAs during digestion is studied and the observed trends support this hypothesis. Copyright © 2010 Elsevier Ltd. All rights reserved.

The Age Specific Incidence Anomaly Suggests that Cancers Originate During Development

NASA Astrophysics Data System (ADS)

Brody, James P.

The accumulation of genetic alterations causes cancers. Since this accumulation takes time, the incidence of most cancers is thought to increase exponentially with age. However, careful measurements of the age-specific incidence show that the specific incidence for many forms of cancer rises with age to a maximum, and then decreases. This decrease in the age-specific incidence with age is an anomaly. Understanding this anomaly should lead to a better understanding of how tumors develop and grow. Here we derive the shape of the age-specific incidence, showing that it should follow the shape of a Weibull distribution. Measurements indicate that the age-specific incidence for colon cancer does indeed follow a Weibull distribution. This analysis leads to the interpretation that for colon cancer two subpopulations exist in the general population: a susceptible population and an immune population. Colon tumors will only occur in the susceptible population. This analysis is consistent with the developmental origins of disease hypothesis and generalizable to many other common forms of cancer.

Preparation of novel oxidized mesoporous carbon with excellent adsorption performance for removal of malachite green and lead ion

NASA Astrophysics Data System (ADS)

Zhang, Xialan; Lin, Qilang; Luo, Shiyuan; Ruan, Kezhao; Peng, Kaiping

2018-06-01

An oxidized mesoporous carbon (OMC) with fluffy structure was fabricated from the mixture of petroleum asphalt and aluminum isopropoxide, and its structures were characterized by FESEM, TEM, BET, TG, XPS and FT-IR. In addition, bath absorption experiments for malachite green (MG) and lead ion (Pb2+) were carried out to explore the effects of pH, initial concentration, contact time and temperature on its absorption process. Results show that the OMC prepared has a fluffy ultrathin-wall structure with narrow pore size distribution and rich oxygen-containing groups. It exhibits excellent absorption performance for the removal of MG as well as Pb2+, as indicated by that its maximum adsorption capacity is 963.1 mg g-1 for MG and 198.6 mg g-1 for Pb2+. The absorption experimental data are all fitted well with pseudo-second-order model and Frendlich isotherm, respectively. More importantly, the OMC still maintains relatively high adsorption capacity after five cycles.

A new failure mechanism in thin film by collaborative fracture and delamination: Interacting duos of cracks

NASA Astrophysics Data System (ADS)

Marthelot, Joël; Bico, José; Melo, Francisco; Roman, Benoît

2015-11-01

When a thin film moderately adherent to a substrate is subjected to residual stress, the cooperation between fracture and delamination leads to unusual fracture patterns, such as spirals, alleys of crescents and various types of strips, all characterized by a robust characteristic length scale. We focus on the propagation of a duo of cracks: two fractures in the film connected by a delamination front and progressively detaching a strip. We show experimentally that the system selects an equilibrium width on the order of 25 times the thickness of the coating and independent of both fracture and adhesion energies. We investigate numerically the selection of the width and the condition for propagation by considering Griffith's criterion and the principle of local symmetry. In addition, we propose a simplified model based on the criterion of maximum of energy release rate, which provides insights of the physical mechanisms leading to these regular patterns, and predicts the effect of material properties on the selected width of the detaching strip.

Modification of porous starch for the adsorption of heavy metal ions from aqueous solution.

PubMed

Ma, Xiaofei; Liu, Xueyuan; Anderson, Debbie P; Chang, Peter R

2015-08-15

Porous starch xanthate (PSX) and porous starch citrate (PSC) were prepared in anticipation of the attached xanthate and carboxylate groups respectively forming chelation and electrostatic interactions with heavy metal ions in the subsequent adsorption process. The lead(II) ion was selected as the model metal and its adsorption by PSX and PSC was characterized. The adsorption capacity was highly dependent on the carbon disulfide/starch and citric acid/starch mole ratios used during preparation. The adsorption behaviors of lead(II) ion on PSXs and PSCs fit both the pseudo-second-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity from the Langmuir isotherm equation reached 109.1 and 57.6 mg/g for PSX and PSC when preparation conditions were optimized, and the adsorption times were just 20 and 60 min, respectively. PSX and PSC may be used as effective adsorbents for removal of heavy metals from contaminated liquid. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

A stochastic maximum principle for backward control systems with random default time

NASA Astrophysics Data System (ADS)

Shen, Yang; Kuen Siu, Tak

2013-05-01

This paper establishes a necessary and sufficient stochastic maximum principle for backward systems, where the state processes are governed by jump-diffusion backward stochastic differential equations with random default time. An application of the sufficient stochastic maximum principle to an optimal investment and capital injection problem in the presence of default risk is discussed.

Enhanced recoverable energy storage density and high efficiency of SrTiO3-based lead-free ceramics

NASA Astrophysics Data System (ADS)

Yang, Haibo; Yan, Fei; Lin, Ying; Wang, Tong

2017-12-01

In this study, (1-x)SrTiO3-x(Bi0.48La0.02Na0.48Li0.02Ti0.98Zr0.02O3) [(1-x)ST-xBLNLTZ] lead-free ceramics with x = 0-0.4 were designed and fabricated using the tape casting process and the subsequent conventional solid-state sintering method. The (1-x)ST-xBLNLTZ ceramics are characterized by the excellent frequency stability of the dielectric constant, large maximum polarization (Pmax), low remnant polarization (Pr), and slim polarization-electric field (P-E) loops. For the composition of x = 0.4, Pmax is increased to 30.35 μC/cm2, 3.82 times higher than that of pure SrTiO3 (7.95 μC/cm2). The breakdown strength is larger than 200 kV/cm for all the samples. The sample with x = 0.1 exhibits a high recoverable energy storage density (Wrec) of 2.59 J/cm3 and a high energy storage efficiency (η) of 85% simultaneously. The results demonstrate that the (1-x)ST-xBLNLTZ ceramics are promising lead-free materials for high energy storage applications.

An Investigation of the Wing and the Wing-Fuselage Combination of a Full-Scale Model of the Republic XP-91 Airplane in the Ames 40-by 80-Foot Wing Tunnel

NASA Technical Reports Server (NTRS)

Hunton, Lynn W.; Dew, Joseph K.

1948-01-01

Wind-tunnel tests of a full-scale model of the Republic XP-91 airplane were conducted to determine the longitudinal and lateral characteristics of the wing alone and the wing-fuselage combination, the characteristics of the aileron, and the damping in roll af the wing alone. Various high-lift devices were investigated including trailing-edge split flaps and partial- and full-span leading-edge slats and Krueger-type nose flaps. Results of this investigation showed that a very significant gain in maximum lift could be achieved through use of the proper leading-edge device, The maximum lift coefficient of the model with split flaps and the original partial-span straight slats was only 1.2; whereas a value of approximately 1.8 was obtained by drooping the slat and extending it full span, Improvement in maximum lift of approximately the same amount resulted when a full-span nose flap was substituted for the original partial-span slat.

Wind-tunnel tests on model wing with Fowler flap and specially developed leading-edge slot

NASA Technical Reports Server (NTRS)

Weick, Fred E; Platt, Robert C

1933-01-01

An investigation was made in the NACA 7 by 10 foot wind tunnel to find the increase in maximum lift coefficient which could be obtained by providing a model wing with both a Fowler trailing-edge extension flap and a Handley Page type leading-edge slot. A conventional Handley page slot proportioned to operate on the plain wing without a flap gave but a slight increase with the flap; so a special form of slot was developed to work more effectively with the flap. With the best combined arrangement the maximum lift coefficient based on the original area was increased from 3.17, for the Fowler wing, to 3.62. The minimum drag coefficient with both devices retracted was increased in approximately the same proportion. Tests were also made with the special-type slot on the plain wing without the flap. The special slot, used either with or without the Fowler flap, gave definitely higher values of the maximum lift coefficient than the slots of conventional form, with an increase of the same order in the minimum drag coefficient.

Three-dimensional flow structures and evolution of the leading-edge vortices on a flapping wing.

PubMed

Lu, Yuan; Shen, Gong Xin

2008-04-01

Following the identification and confirmation of the substructures of the leading-edge vortex (LEV) system on flapping wings, it is apparent that the actual LEV structures could be more complex than had been estimated in previous investigations. In this experimental study, we reveal for the first time the detailed three-dimensional (3-D) flow structures and evolution of the LEVs on a flapping wing in the hovering condition at high Reynolds number (Re=1624). This was accomplished by utilizing an electromechanical model dragonfly wing flapping in a water tank (mid-stroke angle of attack=60 degrees) and applying phase-lock based multi-slice digital stereoscopic particle image velocimetry (DSPIV) to measure the target flow fields at three typical stroke phases: at 0.125 T (T=stroke period), when the wing was accelerating; at 0.25 T, when the wing had maximum speed; and at 0.375 T, when the wing was decelerating. The result shows that the LEV system is a collection of four vortical elements: one primary vortex and three minor vortices, instead of a single conical or tube-like vortex as reported or hypothesized in previous studies. These vortical elements are highly time-dependent in structure and show distinct ;stay properties' at different spanwise sections. The spanwise flows are also time-dependent, not only in the velocity magnitude but also in direction.

A Regularized Linear Dynamical System Framework for Multivariate Time Series Analysis.

PubMed

Liu, Zitao; Hauskrecht, Milos

2015-01-01

Linear Dynamical System (LDS) is an elegant mathematical framework for modeling and learning Multivariate Time Series (MTS). However, in general, it is difficult to set the dimension of an LDS's hidden state space. A small number of hidden states may not be able to model the complexities of a MTS, while a large number of hidden states can lead to overfitting. In this paper, we study learning methods that impose various regularization penalties on the transition matrix of the LDS model and propose a regularized LDS learning framework (rLDS) which aims to (1) automatically shut down LDSs' spurious and unnecessary dimensions, and consequently, address the problem of choosing the optimal number of hidden states; (2) prevent the overfitting problem given a small amount of MTS data; and (3) support accurate MTS forecasting. To learn the regularized LDS from data we incorporate a second order cone program and a generalized gradient descent method into the Maximum a Posteriori framework and use Expectation Maximization to obtain a low-rank transition matrix of the LDS model. We propose two priors for modeling the matrix which lead to two instances of our rLDS. We show that our rLDS is able to recover well the intrinsic dimensionality of the time series dynamics and it improves the predictive performance when compared to baselines on both synthetic and real-world MTS datasets.

Wind-tunnel Investigation of High-lift and Stall-control Devices on a 37 Degree Sweptback Wing of Aspect Ratio 6 at High Reynolds Numbers

NASA Technical Reports Server (NTRS)

Koven, William; Graham, Robert R

1948-01-01

Results are presented of an investigation in the Langley 19-foot pressure tunnel of the longitudinal characteristics of a semispan model wing having 37 degrees sweepback of the leading edge, an aspect ratio of 6, and NACA 641-212 airfoil section perpendicular to the 27-percent-chord line. Several types of stall-control devices including extensible round-nose leading-edge flaps, a leading-edge slat, and a drooped leading edge were investigated; partial- and full-span trailing-edge split and double slotted flaps were also tested. In addition, various combinations of the aforementioned leading- and trailing-edge flaps were investigated. The tests covered a range of Reynolds numbers between 2.00 x 10(6) and 9.35 x 10(6). The wing with or without trailing-edge splity of double slotted flap was longitudinally unstable near maximum lift due to tip stalling. The addition of an outboard half-span leading-edge flap or a leading-edge slat to the plain wing or wing with inboard half-span split flaps eliminated tip stalling and resulted in stable moment variations at the stall. The drooped leading edge, on the other hand, was only effective when used in conjunction with an upper-surface fence. The combination of an outboard leading-edge device and inboard half-span double slotted flap resulted in an undesirable loop in the pitching-moment curve near maximum lift in spite of an inboard stall. The loop is attributed to the section characteristics of the double slotted flap. Air-flow surveys behind the wing indicated that a suitably placed horizontal tail would eliminate the loop in the moment curve.

[Estimation of Maximum Entrance Skin Dose during Cerebral Angiography].

PubMed

Kawauchi, Satoru; Moritake, Takashi; Hayakawa, Mikito; Hamada, Yusuke; Sakuma, Hideyuki; Yoda, Shogo; Satoh, Masayuki; Sun, Lue; Koguchi, Yasuhiro; Akahane, Keiichi; Chida, Koichi; Matsumaru, Yuji

2015-09-01

Using radio-photoluminescence glass dosimeter, we measured the entrance skin dose (ESD) in 46 cases and analyzed the correlations between maximum ESD and angiographic parameters [total fluoroscopic time (TFT); number of digital subtraction angiography (DSA) frames, air kerma at the interventional reference point (AK), and dose-area product (DAP)] to estimate the maximum ESD in real time. Mean (± standard deviation) maximum ESD, dose of the right lens, and dose of the left lens were 431.2 ± 135.8 mGy, 33.6 ± 15.5 mGy, and 58.5 ± 35.0 mGy, respectively. Correlation coefficients (r) between maximum ESD and TFT, number of DSA frames, AK, and DAP were r=0.379 (P<0.01), r=0.702 (P<0.001), r=0.825 (P<0.001), and r=0.709 (P<0.001), respectively. AK was identified as the most useful parameter for real-time prediction of maximum ESD. This study should contribute to the development of new diagnostic reference levels in our country.

27. BUILDING NO. 271I, INTERIOR OF LEAD AZIDE MIXING ROOM. ...

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

27. BUILDING NO. 271-I, INTERIOR OF LEAD AZIDE MIXING ROOM. HERE, TWO POUNDS (MAXIMUM) OF LEAD AZIDE WAS MIXED IN SEVEN SMALL POTS EACH SEPARATED FROM THE OTHERS BY THE STEEL WALLS PICTURED HERE. THE POTS ARE ALL FIXED TO A COMMON SHAFT WHICH IS ROTATED BY A HAND CRANK OUTSIDE OF ROOM (SEE HAER NJ-36A-26). - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

Bipolar lead acid battery development

NASA Technical Reports Server (NTRS)

Eskra, Michael; Vidas, Robin; Miles, Ronald; Halpert, Gerald; Attia, Alan; Perrone, David

1991-01-01

A modular bipolar battery configuration is under development at Johnson Control, Inc. (JCI) and the Jet Propulsion Laboratory (JPL). The battery design, incorporating proven lead acid electrochemistry, yields a rechargeable, high-power source that is light weight and compact. This configuration offers advantages in power capability, weight, and volume over conventional monopolar batteries and other battery chemistries. The lead acid bipolar battery operates in a sealed, maintenance-free mode allowing for maximum application flexibility. It is ideal for high-voltage and high-power applications.

Real-Time PCR Quantification Using A Variable Reaction Efficiency Model

PubMed Central

Platts, Adrian E.; Johnson, Graham D.; Linnemann, Amelia K.; Krawetz, Stephen A.

2008-01-01

Quantitative real-time PCR remains a cornerstone technique in gene expression analysis and sequence characterization. Despite the importance of the approach to experimental biology the confident assignment of reaction efficiency to the early cycles of real-time PCR reactions remains problematic. Considerable noise may be generated where few cycles in the amplification are available to estimate peak efficiency. An alternate approach that uses data from beyond the log-linear amplification phase is explored with the aim of reducing noise and adding confidence to efficiency estimates. PCR reaction efficiency is regressed to estimate the per-cycle profile of an asymptotically departed peak efficiency, even when this is not closely approximated in the measurable cycles. The process can be repeated over replicates to develop a robust estimate of peak reaction efficiency. This leads to an estimate of the maximum reaction efficiency that may be considered primer-design specific. Using a series of biological scenarios we demonstrate that this approach can provide an accurate estimate of initial template concentration. PMID:18570886

A strong astrophysical constraint on the violation of special relativity by quantum gravity.

PubMed

Jacobson, T; Liberati, S; Mattingly, D

2003-08-28

Special relativity asserts that physical phenomena appear the same to all unaccelerated observers. This is called Lorentz symmetry and relates long wavelengths to short ones: if the symmetry is exact it implies that space-time must look the same at all length scales. Several approaches to quantum gravity, however, suggest that there may be a microscopic structure of space-time that leads to a violation of Lorentz symmetry. This might arise because of the discreteness or non-commutivity of space-time, or through the action of extra dimensions. Here we determine a very strong constraint on a type of Lorentz violation that produces a maximum electron speed less than the speed of light. We use the observation of 100-MeV synchrotron radiation from the Crab nebula to improve the previous limit by a factor of 40 million, ruling out this type of Lorentz violation, and thereby providing an important constraint on theories of quantum gravity.

[Applying dose banding to the production of antineoplastic drugs: a narrative review of the literature].

PubMed

Pérez Huertas, Pablo; Cueto Sola, Margarita; Escobar Cava, Paloma; Borrell García, Carmela; Albert Marí, Asunción; López Briz, Eduardo; Poveda Andrés, José Luis

2015-07-01

The dosage of antineoplastic drugs has historically been based on individualized prescription and preparation according to body surface area or patient´s weight. Lack of resources and increased assistance workload in the areas where chemotherapy is made, are leading to the development of new systems to optimize the processing without reducing safety. One of the strategies that has been proposed is the elaboration by dose banding. This new approach standardizes the antineoplastic agents doses by making ranges or bands accepting a percentage of maximum variation. It aims to reduce processing time with the consequent reduction in waiting time for patients; to reduce errors in the manufacturing process and to promote the rational drug use. In conclusion, dose banding is a suitable method for optimizing the development of anticancer drugs, obtaining reductions in oncologic patients waiting time but without actually causing a favorable impact on direct or indirect costs. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Time-resolved second-harmonic generation from gold nanoparticle arrays

NASA Astrophysics Data System (ADS)

Ferrara, D. W.; Tetz, K. A.; McMahon, M. D.; Haglund, R. F., Jr.

2007-09-01

We have studied the effects of planar inversion symmetry and particle-coupling of gold nanoparticle (NP) arrays by angle dependent second-harmonic generation (SHG). Time- and angle- resolved measurements were made using a mode-locked Ti:sapphire 800 nm laser onto gold NP arrays with plasmon resonance tuned to match the laser wavelength in order to produce maximum SHG signal. Finite-difference time domain simulations are used to model the near-field distributions for the various geometries and compared to experiment. The arrays were fabricated by focused ion-beam lithography and metal vapor deposition followed by standard lift-off protocols, producing NPs approximately 20nm high with various in-plane dimensions and interparticle gaps. Above a threshold fluence of ~ 7.3 × 10 -5 mJ/cm2 we find that the SHG scales with the third power of intensity, rather than the second, and atomic-force microscopy shows that the NPs have undergone a reshaping process leading to more nearly spherical shapes.

100-kHz shot-to-shot broadband data acquisition for high-repetition-rate pump-probe spectroscopy.

PubMed

Kanal, Florian; Keiber, Sabine; Eck, Reiner; Brixner, Tobias

2014-07-14

Shot-to-shot broadband detection is common in ultrafast pump-probe spectroscopy. Taking advantage of the intensity correlation of subsequent laser pulses improves the signal-to-noise ratio. Finite data readout times of CCD chips in the employed spectrometer and the maximum available speed of mechanical pump-beam choppers typically limit this approach to lasers with repetition rates of a few kHz. For high-repetition (≥ 100 kHz) systems, one typically averages over a larger number of laser shots leading to inferior signal-to-noise ratios or longer measurement times. Here we demonstrate broadband shot-to-shot detection in transient absorption spectroscopy with a 100-kHz femtosecond laser system. This is made possible using a home-built high-speed chopper with external laser synchronization and a fast CCD line camera. Shot-to-shot detection can reduce the data acquisition time by two orders of magnitude compared to few-kHz lasers while keeping the same signal-to-noise ratio.

Meiotic Studies in Some Species of Tribe Cichorieae (Asteraceae) from Western Himalayas

PubMed Central

Gupta, Raghbir Chand; Goyal, Henna; Singh, Vijay; Goel, Rajesh Kumar

2014-01-01

The present paper deals with meiotic studies in 15 species belonging to 6 genera of the tribe Cichorieae from various localities of Western Himalayas. The chromosome number has been reported for the first time in Hieracium crocatum (2n = 10) and Lactuca lessertiana (2n = 2x = 16). Further, intraspecific variability has been reported for the first time in H. umbellatum (2n = 2x = 10 and 2n = 6x = 54), Tragopogon dubius (2n = 2x = 14 and 2n = 4x = 28), and T. gracilis (2n = 2x = 14). The chromosome report of 2n = 2x = 10 in Youngia tenuifolia is made for the first time in India. Maximum numbers of the populations show laggards, chromosome stickiness, and cytomixis from early prophase to telophase-II, leading to the formation of aneuploid cells or meiocytes with double chromosome number. Such meiotic abnormalities produce unreduced pollen grains and the reduced pollen viability. PMID:25489603

As-Fabricated Reinforced Carbon/Carbon Characterized

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.; Calomino, Anthony M.; Webster, Neal

2004-01-01

Reinforced carbon/carbon (RCC) is a critical material for the space shuttle orbiter. It is used on the wing leading edge and the nose cap, where maximum temperatures are reached on reentry. The existing leading-edge system is a single-plate RCC composite construction with a wall thickness of approximately 1/4 in., making it a prime reliant protection scheme for vehicle operation.

Adjustable lead glass shielding device for use with an over-the-table x-ray tube.

PubMed

Eubig, C; Groves, B M; Davey, G

1978-12-01

Sources of scattered radiation exposure to personnel from a ceiling-mounted x-ray tube were examined at the side of cardiac catheterization patients. A fully adjustable mounting for a lead glass shield was designed to afford maximum radiation protection to the attending physician's head and neck area, while minimizing interference with the procedure.

48 CFR 217.7402 - Exceptions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... maximum extent practicable (also see paragraph (b) of this section): (1) UCAs for foreign military sales...) Congressionally mandated long-lead procurement contracts. (b) If the contracting officer determines that it is...

Stereo and Solar Cycle 24

NASA Technical Reports Server (NTRS)

Kaise,r Michael L.

2008-01-01

The twin STEREO spacecrafi, launched in October 2006, are in heliocentric orbits near 4 AU with one spacecraft (Ahead) leading Earth in its orbit around the Sun and the other (Behind) trailing Earth. As viewed from the Sun, the STEREO spacecraft are continually separating from one another at about 45 degrees per year with Earth biseding the angle. At present, th@spaser=raft are a bit more than 45 degrees apart, thus they are able to each 'vie@ ground the limb's of the Sun by about 23 degrees, corresponding to about 1.75 days of solar rotation. Both spameraft contain an identical set of instruments including an extreme ultraviolet imager, two white light coronagraphs, tws all-sky imagers, a wide selection of energetic particle detectors, a magnetometer and a radio burst tracker. A snapshot of the real time data is continually broadcast to NOW-managed ground stations and this small stream of data is immediately sent to the STEREO Science Center and converted into useful space weather data within 5 minutes of ground receipt. The resulting images, particle, magnetometer and radio astronomy plots are available at j g i t , : gAs timqe conting ues ijnto . g solar cycle 24, the separation angle becomes 90 degrees in early 2009 and 180 degrees in early 201 1 as the activity heads toward maximum. By the time of solar maximum, STEREO will provide for the first time a view of the entire Sun with the mronagraphs and e*reme ultraviolet instruments. This view wilt allow us to follow the evolution of active regions continuously and also detect new active regions long before they pose a space weather threat to Earth. The in situ instruments will be able to provide about 7 days advanced notice of co-rotating structures in the solar wind. During this same intewal near solar maximum, the wide-angle imagers on STEREB will both be ;able to view EarlCP-dirsted CMEs in their plane-oPsky. When combined with Eat-lhorbiting assets available at that time, it seems solar cycle 24 will mark a great increase in our ability to understand and predict space weather.

LPM effect and primary energy estimations

NASA Technical Reports Server (NTRS)

Bourdeau, M. F.; Capdevielle, J. N.

1985-01-01

The distortion of the electron cascade development under LPM effects is now admitted; it consists of an increase of depth of showers origin, of shower maximum T sum max, a decrease of the number of particles at maximum N sub max and results in a flattening and a widening of the cascade transition curve. Connected with the influence of multiple Coulomb scattering on basic electromagnetic processes (bremsstrahlung, pair production), this effect appears at high energy with a threshold dependent on the density of the medium (more than 10 TeV for lead, more than 10 sup 6 TeV in air). Consequently, the electromagnetic components of hadron induced showers in lead and EAS in air calculated for the same hadronic cascades in the different alternative, including or not the LPM effect are examined here.

The effect of low-speed drilling without irrigation on heat generation: an experimental study.

PubMed

Oh, Ji-Hyeon; Fang, Yiqin; Jeong, Seung-Mi; Choi, Byung-Ho

2016-02-01

In this study we evaluated heat generation during the low-speed drilling procedure without irrigation. Ten artificial bone blocks that were similar to human D1 bone were used in this study. The baseline temperature was 37.0℃. We drilled into 5 artificial bone blocks 60 times at the speed of 50 rpm without irrigation. As a control group, we drilled into an additional 5 artificial bone blocks 60 times at the speed of 1,500 rpm with irrigation. The temperature changes during diameter 2 mm drilling were measured using thermocouples. The mean maximum temperatures during drilling were 40.9℃ in the test group and 39.7℃ in the control group. Even though a statistically significant difference existed between the two groups, the low-speed drilling did not produce overheating. These findings suggest that low-speed drilling without irrigation may not lead to overheating during drilling.

Diurnal and seasonal trends in the incidence of Sudden Commencements (SC) and Sudden Impulses SI

NASA Technical Reports Server (NTRS)

Nesmyanovich, E. I.

1974-01-01

Based on world data for the period 1 January 1955 to 31 December 1968, reports of 894 SC cases and 2152 SI cases were collected. A study was made of the diurnal and seasonal trends in the incidence of their appearances. It is shown that the diurnal trend is pronounced for all events with a maximum at (06-8)h universal time. The diurnal trend for SC in the resultant period is more pronounced. The seasonal trend in incidence of appearances of SC and SI is absent. Thus, geomagnetic disturbances of both SC and SI are monitored by world time. These results lead to the conclusion that the presence or absence of SC and SI during geomagnetic storms is determined not only by the nature of the corpuscular flux, the presence of shock waves and tangential discontinuities, but also by purely terrestrial conditions.

Adaptive filtering and maximum entropy spectra with application to changes in atmospheric angular momentum

NASA Technical Reports Server (NTRS)

Penland, Cecile; Ghil, Michael; Weickmann, Klaus M.

1991-01-01

The spectral resolution and statistical significance of a harmonic analysis obtained by low-order MEM can be improved by subjecting the data to an adaptive filter. This adaptive filter consists of projecting the data onto the leading temporal empirical orthogonal functions obtained from singular spectrum analysis (SSA). The combined SSA-MEM method is applied both to a synthetic time series and a time series of AAM data. The procedure is very effective when the background noise is white and less so when the background noise is red. The latter case obtains in the AAM data. Nevertheless, reliable evidence for intraseasonal and interannual oscillations in AAM is detected. The interannual periods include a quasi-biennial one and an LF one, of 5 years, both related to the El Nino/Southern Oscillation. In the intraseasonal band, separate oscillations of about 48.5 and 51 days are ascertained.

Multi-stage phononic crystal structure for anchor-loss reduction of thin-film piezoelectric-on-silicon microelectromechanical-system resonator

NASA Astrophysics Data System (ADS)

Bao, Fei-Hong; Bao, Lei-Lei; Li, Xin-Yi; Ammar Khan, Muhammad; Wu, Hua-Ye; Qin, Feng; Zhang, Ting; Zhang, Yi; Bao, Jing-Fu; Zhang, Xiao-Sheng

2018-06-01

Thin-film piezoelectric-on-silicon acoustic wave resonators are promising for the development of system-on-chip integrated circuits with micro/nano-engineered timing reference. However, in order to realize their large potentials, a further enhancement of the quality factor (Q) is required. In this study, a novel approach, based on a multi-stage phononic crystal (PnC) structure, was proposed to achieve an ultra-high Q. A systematical study revealed that the multi-stage PnC structure formed a frequency-selective band-gap to effectively prohibit the dissipation of acoustic waves through tethers, which significantly reduced the anchor loss, leading to an insertion-loss reduction and enhancement of Q. The maximum unloaded Q u of the fabricated resonators reached the value of ∼10,000 at 109.85 MHz, indicating an enhancement by 19.4 times.

Creep-Fatigue Behavior of Alloy 617 at 850 and 950°C, Revision 2

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

Carroll, L.; Carroll, M.

Alloy 617 is the leading candidate material for an Intermediate Heat Exchanger (IHX) of the Very High Temperature Reactor (VHTR). To evaluate the behavior of this material in the expected service conditions, strain-controlled cyclic tests including hold times up to 9000 s at maximum tensile strain were conducted at 850 and 950 degrees C. At both temperatures, the fatigue resistance decreased when a hold time was added at peak tensile strain. The magnitude of this effect depended on the specific mechanisms and whether they resulted in a change in fracture mode from transgranular in pure fatigue to intergranular in creep-fatiguemore » for a particular temperature and strain range combination. Increases in the tensile hold duration beyond an initial value were not detrimental to the creep-fatigue resistance at 950 degrees C but did continue to degrade the lifetimes at 850 degrees C.« less

Instant power generation from an air-breathing paper and pencil based bacterial bio-fuel cell.

PubMed

Veerubhotla, Ramya; Bandopadhyay, Aditya; Das, Debabrata; Chakraborty, Suman

2015-06-21

We present a low-cost, disposable microbial fuel cell fabricated on a paper based platform, having a start-up time of 10 s. The platform deploys ordinary pencil strokes for graphite electrode deposition. The device uses a membrane-less design in a one-time injection (OTI) mode or a continuous capillary driven flow mode (CPF), where oxygen from the atmosphere is used up at the cathode for water formation, leading to the generation of bioelectricity. The performance of the fuel cell is evaluated using two bacterial strains, namely, Pseudomonas aeruginosa IIT BT SS1 and Shewanella putrefaciens. This flexible device is shown to retain bacteria for a period of at least one hour, resulting in the generation of almost 0.4 V using P. aeruginosa and a maximum current of 18 μA using S. putrefaciens without the use of any additional catalysts.

An exploratory study of lead recovery in lead-acid battery lifecycle in US market: an evidence-based approach.

PubMed

Genaidy, A M; Sequeira, R; Tolaymat, T; Kohler, J; Rinder, M

2008-12-15

This research examines lead recovery and recycling in lead-acid batteries (LAB) which account for 88% of US lead consumption. We explore strategies to maximize lead recovery and recycling in the LAB lifecycle. Currently, there is limited information on recycling rates for LAB in the published literature and is derived from a single source. Therefore, its recycling efforts in the US has been unclear so as to determine the maximum opportunities for metal recovery and recycling in the face of significant demands for LAB particularly in the auto industry. The research utilizes an evidence-based approach to: (1) determine recycling rates for lead recovery in the LAB product lifecycle for the US market; and (2) quantify and identify opportunities where lead recovery and recycling can be improved. A comprehensive electronic search of the published literature was conducted to gather information on different LAB recycling models and actual data used to calculate recycling rates based on product lifecycle for the US market to identify strategies for increasing lead recovery and recycling. The electronic search yielded five models for calculating LAB recycling rates. The description of evidence was documented for each model. Furthermore, an integrated model was developed to identify and quantify the maximum opportunities for lead recovery and recycling. Results showed that recycling rates declined during the period spanning from 1999 to 2006. Opportunities were identified for recovery and recycling of lead in the LAB product lifecycle. One can deduce the following from the analyses undertaken in this report: (1) lead recovery and recycling has been stable between 1999 and 2006; (2) lead consumption has increased at an annual rate of 2.25%, thus, the values derived in this study for opportunities dealing with lead recovery and recycling underestimate the amount of lead in scrap and waste generated; and (3) the opportunities for maximizing lead recovery and recycling are centered on spent batteries left with consumers, mishandled LAB sent to auto wreckers, slag resulting from recycling technology process inefficiencies, and lead lost in municipal waste.

Photon Interaction Parameters for Some Borate Glasses

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

Mann, Nisha; Kaur, Updesh; Singh, Tejbir

2010-11-06

Some photon interaction parameters of dosimetric interest such as mass attenuation coefficients, effective atomic number, electron density and KERMA relative to air have been computed in the wide energy range from 1 keV to 100 GeV for some borate glasses viz. barium-lead borate, bismuth-borate, calcium-strontium borate, lead borate and zinc-borate glass. It has been observed that lead borate glass and barium-lead borate glass have maximum values of mass attenuation coefficient, effective atomic number and KERMA relative to air. Hence, these borate glasses are suitable as gamma ray shielding material, packing of radioactive sources etc.

System factors to explain H1N1 state vaccination rates for adults in US emergency response to pandemic.

PubMed

Davila-Payan, Carlo; Swann, Julie; Wortley, Pascale M

2014-05-23

During the 2009-2010 H1N1 pandemic, vaccine in short supply was allocated to states pro rata by population, yet the vaccination rates of adults differed by state. States also differed in their campaign processes and decisions. Analyzing the campaign provides an opportunity to identify specific approaches that may result in higher vaccine uptake in a future event of this nature. To determine supply chain and system factors associated with higher state H1N1 vaccination coverage for adults in a system where vaccine was in short supply. Regression analysis of factors predicting state-specific H1N1 vaccination coverage in adults. Independent variables included state campaign information, demographics, preventive or health-seeking behavior, preparedness funding, providers, state characteristics, and H1N1-specific state data. The best model explained the variation in state-specific adult vaccination coverage with an adjusted R-squared of 0.76. We found that higher H1N1 coverage of adults is associated with program aspects including shorter lead-times (i.e., the number of days between when doses were allocated to a state and were shipped, including the time for states to order the doses) and less vaccine directed to specialist locations. Higher vaccination coverage is also positively associated with the maximum number of ship-to locations, past seasonal influenza vaccination coverage, the percentage of women with a Pap smear, the percentage of the population that is Hispanic, and negatively associated with a long duration of the epidemic peak. Long lead-times may be a function of system structure or of efficiency and may suggest monitoring or redesign of distribution processes. Sending vaccine to sites with broad access could be useful when covering a general population. Existing infrastructure may be reflected in the maximum number of ship-to locations, so strengthening routine influenza vaccination programs may help during emergency vaccinations also. Future research could continue to inform program decisions. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effects of 12-week supervised treadmill training on spatio-temporal gait parameters in patients with claudication.

PubMed

Konik, Anita; Kuklewicz, Stanisław; Rosłoniec, Ewelina; Zając, Marcin; Spannbauer, Anna; Nowobilski, Roman; Mika, Piotr

2016-01-01

The purpose of the study was to evaluate selected temporal and spatial gait parameters in patients with intermittent claudication after completion of 12-week supervised treadmill walking training. The study included 36 patients (26 males and 10 females) aged: mean 64 (SD 7.7) with intermittent claudication. All patients were tested on treadmill (Gait Trainer, Biodex). Before the programme and after its completion, the following gait biomechanical parameters were tested: step length (cm), step cycle (cycle/s), leg support time (%), coefficient of step variation (%) as well as pain-free walking time (PFWT) and maximal walking time (MWT) were measured. Training was conducted in accordance with the current TASC II guidelines. After 12 weeks of training, patients showed significant change in gait biomechanics consisting in decreased frequency of step cycle (p < 0.05) and extended step length (p < 0.05). PFWT increased by 96% (p < 0.05). MWT increased by 100% (p < 0.05). After completing the training, patients' gait was more regular, which was expressed via statistically significant decrease of coefficient of variation (p < 0.05) for both legs. No statistically significant relation between the post-training improvement of PFWT and MWT and step length increase and decreased frequency of step cycle was observed (p > 0.05). Twelve-week treadmill walking training programme may lead to significant improvement of temporal and spatial gait parameters in patients with intermittent claudication. Twelve-week treadmill walking training programme may lead to significant improvement of pain-free walking time and maximum walking time in patients with intermittent claudication.

Early, but not late visual distractors affect movement synchronization to a temporal-spatial visual cue.

PubMed

Booth, Ashley J; Elliott, Mark T

2015-01-01

The ease of synchronizing movements to a rhythmic cue is dependent on the modality of the cue presentation: timing accuracy is much higher when synchronizing with discrete auditory rhythms than an equivalent visual stimulus presented through flashes. However, timing accuracy is improved if the visual cue presents spatial as well as temporal information (e.g., a dot following an oscillatory trajectory). Similarly, when synchronizing with an auditory target metronome in the presence of a second visual distracting metronome, the distraction is stronger when the visual cue contains spatial-temporal information rather than temporal only. The present study investigates individuals' ability to synchronize movements to a temporal-spatial visual cue in the presence of same-modality temporal-spatial distractors. Moreover, we investigated how increasing the number of distractor stimuli impacted on maintaining synchrony with the target cue. Participants made oscillatory vertical arm movements in time with a vertically oscillating white target dot centered on a large projection screen. The target dot was surrounded by 2, 8, or 14 distractor dots, which had an identical trajectory to the target but at a phase lead or lag of 0, 100, or 200 ms. We found participants' timing performance was only affected in the phase-lead conditions and when there were large numbers of distractors present (8 and 14). This asymmetry suggests participants still rely on salient events in the stimulus trajectory to synchronize movements. Subsequently, distractions occurring in the window of attention surrounding those events have the maximum impact on timing performance.

The Alberta smoke plume observation study

NASA Astrophysics Data System (ADS)

Anderson, Kerry; Pankratz, Al; Mooney, Curtis; Fleetham, Kelly

2018-02-01

A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS). Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018) at http://cwfis.cfs.nrcan.gc.ca/datamart.

Implementation of bayesian model averaging on the weather data forecasting applications utilizing open weather map

NASA Astrophysics Data System (ADS)

Rahmat, R. F.; Nasution, F. R.; Seniman; Syahputra, M. F.; Sitompul, O. S.

2018-02-01

Weather is condition of air in a certain region at a relatively short period of time, measured with various parameters such as; temperature, air preasure, wind velocity, humidity and another phenomenons in the atmosphere. In fact, extreme weather due to global warming would lead to drought, flood, hurricane and other forms of weather occasion, which directly affects social andeconomic activities. Hence, a forecasting technique is to predict weather with distinctive output, particullary mapping process based on GIS with information about current weather status in certain cordinates of each region with capability to forecast for seven days afterward. Data used in this research are retrieved in real time from the server openweathermap and BMKG. In order to obtain a low error rate and high accuracy of forecasting, the authors use Bayesian Model Averaging (BMA) method. The result shows that the BMA method has good accuracy. Forecasting error value is calculated by mean square error shows (MSE). The error value emerges at minumum temperature rated at 0.28 and maximum temperature rated at 0.15. Meanwhile, the error value of minimum humidity rates at 0.38 and the error value of maximum humidity rates at 0.04. Afterall, the forecasting error rate of wind speed is at 0.076. The lower the forecasting error rate, the more optimized the accuracy is.

Characteristics of the turbulence in the flow at a tidal stream power site.

PubMed

Milne, I A; Sharma, R N; Flay, R G J; Bickerton, S

2013-02-28

This paper analyses a set of velocity time histories which were obtained at a fixed point in the bottom boundary layer of a tidal stream, 5 m from the seabed, and where the mean flow reached 2.5 m s(-1). Considering two complete tidal cycles near spring tide, the streamwise turbulence intensity during non-slack flow was found to be approximately 12-13%, varying slightly between flood and ebb tides. The ratio of the streamwise turbulence intensity to that of the transverse and vertical intensities is typically 1 : 0.75 : 0.56, respectively. Velocity autospectra computed near maximum flood tidal flow conditions exhibit an f(-2/3) inertial subrange and conform reasonably well to atmospheric turbulence spectral models. Local isotropy is observed between the streamwise and transverse spectra at reduced frequencies of f>0.5. The streamwise integral time scales and length scales of turbulence at maximum flow are approximately 6 s and 11-14 m, respectively, and exhibit a relatively large degree of scatter. They are also typically much greater in magnitude than the transverse and vertical components. The findings are intended to increase the levels of confidence within the tidal energy industry of the characteristics of the higher frequency components of the onset flow, and subsequently lead to more realistic performance and loading predictions.

Advanced direct coal liquefaction concepts. Quarterly report, January 1, 1993--March 31, 1993

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

Berger, D.J.; Parker, R.J.; Simpson, P.L.

1993-07-01

Five barrels of a Wilsonville process derived solvent (V-1074) from Black Thunder coal were obtained. This material boils within the preferred gas oil range, is more aromatic than previous solvents, and will therefore be used for the bench unit studies. Several repeat runs were performed in the autoclave to confirm the results of the matrix study. In addition, runs were carried out with different catalysts, with agglomerates and with the V-1074 solvent. The results of the autoclave runs were analyzed with respect to coal conversion, CO conversion, oil yield, hydrogen consumption and oxygen removal. It was concluded that the bestmore » operating conditions for the first stage operation was a temperature of at least 390{degrees}C, residence time of at least 30 minutes, cold CO pressure of at least 600 psig and potassium carbonate catalyst (2% wt on total feed). The data also indicated however, that the coal conversion goes through a maximum, and too high a severity leads to retrograde reaction and lower coal solubilization. The scope for increasing temperature and time is therefore limited. Petrographic examination of the THF insoluble resids from the autoclave program indicated a maximum coal conversion of about 90% for Black Thunder coal. The bench unit construction was also essentially completed and the bench unit program to be carded out in the next twelve months was defined.« less

The Record Los Angeles Heat Event of September 2010: 1. Synoptic-Scale-Meso-β-Scale Analyses of Interactive Planetary Wave Breaking, Terrain- and Coastal-Induced Circulations

NASA Astrophysics Data System (ADS)

Kaplan, Michael L.; Tilley, Jeffrey S.; Hatchett, Benjamin J.; Smith, Craig M.; Walston, Joshua M.; Shourd, Kacie N.; Lewis, John M.

2017-10-01

On 27 September 2010 the Los Angeles Civic Center reached its all-time record maximum temperature of 45°C before 1330 local daylight time with several other regional stations observing all-time record breaking heat early in that afternoon. This record event is associated with a general circulation pattern predisposed to hemispheric wave breaking. Three days before the event, wave breaking organizes complex terrain- and coastal-induced processes that lead to isentropic surface folding into the Los Angeles Basin. The first wave break occurs over the western two thirds of North America leading to trough elongation across the southwestern U.S. Collocated with this trough is an isentropic potential vorticity filament that is the locus of a thermally indirect circulation central to warming and associated thickness increases and ridging westward across the Great Basin. In response to this circulation, two subsynoptic wave breaks are triggered along the Pacific coast. The isentropic potential vorticity filament is coupled to the breaking waves and the interaction produces a subsynoptic low-pressure center and a deep vortex aloft over the southeastern California desert. This coupling leads to advection of an elevated mixed layer over Point Conception the night before the record-breaking heat that creates a coastally trapped low-pressure area southwest of Los Angeles. The two low-pressure centers create a low-level pressure gradient and east-southeasterly jet directed offshore over the Los Angeles Basin by sunrise on 27 September. This allows the advection of low-level warm air from the inland terrain toward the coastally trapped disturbance and descending circulation resulting in record heating.

Selective ionic liquid ferrofluid based dispersive-solid phase extraction for simultaneous preconcentration/separation of lead and cadmium in milk and biological samples.

PubMed

Fasih Ramandi, Negin; Shemirani, Farzaneh

2015-01-01

For the first time, a selective ionic liquid ferrofluid has been used in dispersive solid phase extraction (IL-FF-D-SPE) for simultaneous preconcentration and separation of lead and cadmium in milk and biological samples combined with flame atomic absorption spectrometry. To improve the selectivity of the ionic liquid ferrofluid, the surface of TiO2 nanoparticles with a magnetic core as sorbent was modified by loading 1-(2-pyridylazo)-2-naphtol. Due to the rapid injection of an appropriate amount of ionic liquid ferrofluid into the aqueous sample by a syringe, extraction can be achieved within a few seconds. In addition, based on the attraction of the ionic liquid ferrofluid to a magnet, no centrifugation step is needed for phase separation. The experimental parameters of IL-FF-D-SPE were optimized using a Box-Behnken design (BBD) after a Plackett-Burman screening design. Under the optimum conditions, the relative standard deviations of 2.2% and 2.4% were obtained for lead and cadmium, respectively (n=7). The limit of detections were 1.21 µg L(-1) for Pb(II) and 0.21 µg L(-1) for Cd(II). The preconcentration factors were 250 for lead and 200 for cadmium and the maximum adsorption capacities of the sorbent were 11.18 and 9.34 mg g(-1) for lead and cadmium, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

Diel cycles in dissolved barium, lead, iron, vanadium, and nitrite in a stream draining a former zinc smelter site near Hegeler, Illinois

USGS Publications Warehouse

Kay, R.T.; Groschen, G.E.; Cygan, G.; Dupre, David H.

2011-01-01

Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90. min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium, and barium may have been affected by competition with Fe+2 for sorption sites on hydrous ferric oxide minerals. ?? 2010.

Kaon and open charm production in central lead-lead collisions at the CERN SPS

NASA Astrophysics Data System (ADS)

van Leeuwen, Marco

2003-05-01

This thesis describes the experimental study of hadronic systems with a very high energy density and temperature. From theoretical caluclations it is expected that hadronic matter undergoes a phase transition to a deconfined state at an energy density of about 1 GeV/fm^3 or a temperature of 170 MeV. The goal of the experiments is to observe the phase transition and study the properties of the deconfined state, the Quark Gluon Plasma (QGP). Two different measurements are described and the results are discussed. The first measurement concerns the momentum distributions and total yields of kaons in lead-lead collisions at 40, 80 and 158 AGeV beam energy. Kaons are the most abundant carrier of the relatively heavy strange quarks and their production is expected to be sensitive to the energy density and the state of matter early in the collision. The second measurement is a search for the production of mesons which carry the even heavier charm quark, at the highest beam energy. The measurements have been performed with the NA49 detector at the SPS accelerator at CERN. The main detector elements are four Time Projection Chambers (TPCs), which record the trajectories of a large fraction of the final state particles to determine the charge and the momentum of each particle. In addition, the measurement of the ionisation energy loss dE/dx in the TPCs allows to identify pions, kaons and protons. Additional detectors provide a measurement of the time-of-flight in a limited acceptance. Combining the time-of-flight and dE/dx measurements greatly improves the separation of the different particle species. The kaon momentum distributions as presented in this thesis have been determined using the dE/dx measurement in the TPCs. The time-of-flight information is used for a detailed study of the peak shape of the dE/dx measurement. The resulting kaon spectra and total yields provide strong indications that interactions between produced particles or even thermalisation play an important role in nucleus-nucleus collisions. The measured kaon yields are compared to two different models which are based on purely hadronic processes, not taking into account the possible phase transition to the QGP. The hadron-transport model RQMD takes into account collisions between produced particles, and the Hadron Gas Model assumes thermalisation. Both models are in reasonable agreement with the data. A model which does assume the phase transition, the Statistical Model of the Early Stage (SMES), shows even better agreement with the data. It predicts a sharp maximum in the strangeness to pion ratio between 10 AGeV, the highest beam energy of earlier experiments, and 40 AGeV, the lowest beam energy used in this thesis. The present data are consistent with this prediction, but future measurements at 20 and 30 AGeV will decide whether the sharp maximum is indeed observed. If indeed an equilibrium QGP is formed at the highest SPS energies, as is expected within the SMES, this would also lead to a relatively large production of charm quarks and hence open charm mesons. Therefore, a large sample of three million lead-lead events at 158 AGeV was taken to search for open charm production. No signal has been observed in the analysis, implying that the charm yield is lower than the expected yield in an equilibrium QGP. It is concluded that if a QGP is formed in the collisions, it does not live long enough or has too low a temperature to allow the charm production to reach equilibrium.

[Travel time and distances to Norwegian out-of-hours casualty clinics].

PubMed

Raknes, Guttorm; Morken, Tone; Hunskår, Steinar

2014-11-01

Geographical factors have an impact on the utilisation of out-of-hours services. In this study we have investigated the travel distance to out-of-hours casualty clinics in Norwegian municipalities in 2011 and the number of municipalities covered by the proposed recommendations for secondary on-call arrangements due to long distances. We estimated the average maximum travel times and distances in Norwegian municipalities using a postcode-based method. Separate analyses were performed for municipalities with a single, permanently located casualty clinic. Altogether 417 out of 430 municipalities were included. We present the median value of the maximum travel times and distances for the included municipalities. The median maximum average travel distance for the municipalities was 19 km. The median maximum average travel time was 22 minutes. In 40 of the municipalities (10 %) the median maximum average travel time exceeded 60 minutes, and in 97 municipalities (23 %) the median maximum average travel time exceeded 40 minutes. The population of these groups comprised 2 % and 5 % of the country's total population respectively. For municipalities with permanent emergency facilities(N = 316), the median average flight time 16 minutes and median average distance 13 km.. In many municipalities, the inhabitants have a long average journey to out-of-hours emergency health services, but seen as a whole, the inhabitants of these municipalities account for a very small proportion of the Norwegian population. The results indicate that the proposed recommendations for secondary on-call duty based on long distances apply to only a small number of inhabitants. The recommendations should therefore be adjusted and reformulated to become more relevant.

40 CFR 421.252 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.546 0.260 Mercury 0.325 0.130 Silver 0.533 0.221 Zinc 1.898 0.793 Gold 0.130 Oil....164 0.068 Zinc 0.584 0.244 Gold 0.040 Oil and grease 8.000 4.800 Total suspended solids 16.400 7.800 p...

40 CFR 421.252 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.546 0.260 Mercury 0.325 0.130 Silver 0.533 0.221 Zinc 1.898 0.793 Gold 0.130 Oil....164 0.068 Zinc 0.584 0.244 Gold 0.040 Oil and grease 8.000 4.800 Total suspended solids 16.400 7.800 p...

40 CFR 421.252 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average mg/troy ounce of gold and silver smelted Lead 0.546 0.260 Mercury 0.325 0.130 Silver 0.533 0.221 Zinc 1.898 0.793 Gold 0.130 Oil....164 0.068 Zinc 0.584 0.244 Gold 0.040 Oil and grease 8.000 4.800 Total suspended solids 16.400 7.800 p...

Latency study of the High Performance Time to Digital Converter for the ATLAS Muon Spectrometer trigger upgrade

NASA Astrophysics Data System (ADS)

Meng, X. T.; Levin, D. S.; Chapman, J. W.; Li, D. C.; Yao, Z. E.; Zhou, B.

2017-02-01

The High Performance Time to Digital Converter (HPTDC), a multi-channel ASIC designed by the CERN Microelectronics group, has been proposed for the digitization of the thin-Resistive Plate Chambers (tRPC) in the ATLAS Muon Spectrometer Phase-1 upgrade project. These chambers, to be staged for higher luminosity LHC operation, will increase trigger acceptance and reduce or eliminate the fake muon trigger rates in the barrel-endcap transition region, corresponding to pseudo-rapidity range 1<|η|<1.3. Low level trigger candidates must be flagged within a maximum latency of 1075 ns, thus imposing stringent signal processing time performance requirements on the readout system in general, and on the digitization electronics in particular. This paper investigates the HPTDC signal latency performance based on a specially designed evaluation board coupled with an external FPGA evaluation board, when operated in triggerless mode, and under hit rate conditions expected in Phase-I. This hardware based study confirms previous simulations and demonstrates that the HPTDC in triggerless operation satisfies the digitization timing requirements in both leading edge and pair modes.

Contributed Review: Source-localization algorithms and applications using time of arrival and time difference of arrival measurements

DOE PAGES

Li, Xinya; Deng, Zhiqun Daniel; Rauchenstein, Lynn T.; ...

2016-04-01

Locating the position of fixed or mobile sources (i.e., transmitters) based on received measurements from sensors is an important research area that is attracting much research interest. In this paper, we present localization algorithms using time of arrivals (TOA) and time difference of arrivals (TDOA) to achieve high accuracy under line-of-sight conditions. The circular (TOA) and hyperbolic (TDOA) location systems both use nonlinear equations that relate the locations of the sensors and tracked objects. These nonlinear equations can develop accuracy challenges because of the existence of measurement errors and efficiency challenges that lead to high computational burdens. Least squares-based andmore » maximum likelihood-based algorithms have become the most popular categories of location estimators. We also summarize the advantages and disadvantages of various positioning algorithms. By improving measurement techniques and localization algorithms, localization applications can be extended into the signal-processing-related domains of radar, sonar, the Global Positioning System, wireless sensor networks, underwater animal tracking, mobile communications, and multimedia.« less

Contributed Review: Source-localization algorithms and applications using time of arrival and time difference of arrival measurements

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

Li, Xinya; Deng, Zhiqun Daniel; Rauchenstein, Lynn T.

Locating the position of fixed or mobile sources (i.e., transmitters) based on received measurements from sensors is an important research area that is attracting much research interest. In this paper, we present localization algorithms using time of arrivals (TOA) and time difference of arrivals (TDOA) to achieve high accuracy under line-of-sight conditions. The circular (TOA) and hyperbolic (TDOA) location systems both use nonlinear equations that relate the locations of the sensors and tracked objects. These nonlinear equations can develop accuracy challenges because of the existence of measurement errors and efficiency challenges that lead to high computational burdens. Least squares-based andmore » maximum likelihood-based algorithms have become the most popular categories of location estimators. We also summarize the advantages and disadvantages of various positioning algorithms. By improving measurement techniques and localization algorithms, localization applications can be extended into the signal-processing-related domains of radar, sonar, the Global Positioning System, wireless sensor networks, underwater animal tracking, mobile communications, and multimedia.« less

Maximum likelihood estimation of signal-to-noise ratio and combiner weight

NASA Technical Reports Server (NTRS)

Kalson, S.; Dolinar, S. J.

1986-01-01

An algorithm for estimating signal to noise ratio and combiner weight parameters for a discrete time series is presented. The algorithm is based upon the joint maximum likelihood estimate of the signal and noise power. The discrete-time series are the sufficient statistics obtained after matched filtering of a biphase modulated signal in additive white Gaussian noise, before maximum likelihood decoding is performed.

Simulation of blast-induced early-time intracranial wave physics leading to traumatic brain injury.

PubMed

Taylor, Paul A; Ford, Corey C

2009-06-01

The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm3 voxels) five material model of the human head was created by segmentation of color cryosections from the Visible Human Female data set. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior, and lateral directions. Three-dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric stress within the first 2 ms of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 ms time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early-time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI.

Thermochemical formation of polychlorinated dibenzo-p-dioxins and dibenzofurans on the fly ash matrix from metal smelting sources.

PubMed

Wu, Xiaolin; Zheng, Minghui; Zhao, Yuyang; Yang, Hongbo; Yang, Lili; Jin, Rong; Xu, Yang; Xiao, Ke; Liu, Wenbin; Liu, Guorui

2018-01-01

Metal smelting processes are important sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The present work aims to clarify the formation characteristics of PCDD/Fs by heterogeneous mechanisms on fly ash from typical multiple secondary aluminum (SAl), secondary lead (SPb) smelting, and iron ore sintering (SNT) sources in China. The formation characteristics of PCDD/Fs on fly ash were studied in the temperature range 250-450 °C for 10-150 min. Substantial thermochemical formation of PCDD/Fs on SAl and SNT ash was observed. The maximum increase of PCDD/F concentrations under 350 °C for 30 min was 604 times greater than the initial concentration in SAl ash. The concentration of PCDD/Fs was 77 times greater than that of SNT fly ash under 350 °C for 30 min. However, the maximum increase of PCDD/F concentrations was less than 8 times that in raw SPb ash under 350 °C. Contents of total organic carbon (TOC), Cu, Al, Zn and Cl, which are widely recognized as important elements for promoting PCDD/F formation, were obviously higher in SAl and SNT ash than in SPb ash. This may explain the greater observed formation times of PCDD/Fs on SAl and SNT ash than that on SPb ash. It was found that several congeners tended to form at higher temperatures than those for SAl ash. Activation energy calculation according to the Arrhenius equations could explain the dominant formation of those congeners at much higher temperatures on SAl ash. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modeling and simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury.

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

Ford, Corey C.; Taylor, Paul Allen

The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm{sup 3} voxels), 5 material model of the human head was created by segmentation of color cryosections from the Visible Human Female dataset. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior and lateral directions. Three dimensional plots ofmore » maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric (shear) stress within the first 2 milliseconds of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 msec time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI.« less

Effect of the RC time on photocurrent transients and determination of charge carrier mobilities

NASA Astrophysics Data System (ADS)

Kniepert, Juliane; Neher, Dieter

2017-11-01

We present a closed analytical model to describe time dependent photocurrents upon pulsed illumination in the presence of an external RC circuit. In combination with numerical drift diffusion simulations, it is shown that the RC time has a severe influence on the shape of the transients. In particular, the maximum of the photocurrent is delayed due to a delayed recharging of the electrodes. This delay increases with the increasing RC constant. As a consequence, charge carrier mobilities determined from simple extrapolation of the initial photocurrent decay will be in general too small and feature a false dependence on the electric field. Here, we present a recipe to correct charge carrier mobilities determined from measured photocurrent transients by taking into account the RC time of the experimental set-up. We also demonstrate how the model can be used to more reliably determine the charge carrier mobility from experimental data of a typical polymer/fullerene organic solar cell. It is shown that further aspects like a finite rising time of the pulse generator and the current contribution of the slower charger carriers influence the shape of the transients and may lead to an additional underestimation of the transit time.

RF dual-gate-trench LDMOS on InGaAs with improved performance

NASA Astrophysics Data System (ADS)

Payal, M.; Singh, Y.

2018-02-01

A new power dual-gate-trench LDMOSFET (DGTLDMOS) structure implemented on emerging InGaAs material is proposed. The proposed device consists of two gates out of which one gate is placed horizontally on the surface while other gate is located vertically in a trench. The dual-gate structure of DGTLDMOS creates two channels in p-base which carry current simultaneously from drain to source. This not only enhances the drain current (ID) but also reduces specific on-resistance (Ron,sp) and improves the peak transconductance (gm) resulting higher cut-off frequency (fT) and maximum oscillation frequency (fmax). Another trench filled with Al2O3 is placed in the drift region between gate and drain to enhance reduced-surface-field effect leading to higher breakdown voltage (Vbr) even at increased drift region doping. Based on 2D simulations, it is demonstrate that a DGTLDMOS designed for Vbr of 90 V achieves 2.2 times higher ID, 10 times reduction in Ron,sp, 1.8 times improvement in gm, 2.8 times increase in fT, and 1.8 times improvement in fmax with 3.3 times reduction in cell pitch as compared to the conventional LDMOS.

Real-time OHT Dispatching Mechanism for the Interbay Automated Material Handling System with Shortcuts and Bypasses

NASA Astrophysics Data System (ADS)

Pan, Cong; Zhang, Jie; Qin, Wei

2017-05-01

As a key to improve the performance of the interbay automated material handling system (AMHS) in 300 mm semiconductor wafer fabrication system, the real-time overhead hoist transport (OHT) dispatching problem has received much attention. This problem is first formulated as a special form of assignment problem and it is proved that more than one solution will be obtained by Hungarian algorithm simultaneously. Through proposing and strictly proving two propositions related to the characteristics of these solutions, a modified Hungarian algorithm is designed to distinguish these solutions. Finally, a new real-time OHT dispatching method is carefully designed by implementing the solution obtained by the modified Hungarian algorithm. The experimental results of discrete event simulations show that, compared with conventional Hungarian algorithm dispatching method, the proposed dispatching method that chooses the solution with the maximum variance respectively reduces on average 4 s of the average waiting time and average lead time of wafer lots, and its performance is rather stable in multiple different scenarios of the interbay AMHS with different quantities of shortcuts. This research provides an efficient real-time OHT dispatching mechanism for the interbay AMHS with shortcuts and bypasses.

Lightning climatology in the Congo Basin: detailed analysis

NASA Astrophysics Data System (ADS)

Soula, Serge; Kigotsi, Jean; Georgis, Jean-François; Barthe, Christelle

2016-04-01

The lightning climatology of the Congo Basin including several countries of Central Africa is analyzed in detail for the first time. It is based on World Wide Lightning Location Network (WWLLN) data for the period from 2005 to 2013. A comparison of these data with the Lightning Imaging Sensor (LIS) data for the same period shows the WWLLN detection efficiency (DE) in the region increases from about 1.70 % in the beginning of the period to 5.90 % in 2013, relative to LIS data, but not uniformly over the whole 2750 km × 2750 km area. Both the annual flash density and the number of stormy days show sharp maximum values localized in eastern of Democratic Republic of Congo (DRC) and west of Kivu Lake, regardless of the reference year and the period of the year. These maxima reach 12.86 fl km-2 and 189 days, respectively, in 2013, and correspond with a very active region located at the rear of the Virunga mountain range characterised with summits that can reach 3000 m. The presence of this range plays a role in the thunderstorm development along the year. The estimation of this local maximum of the lightning density by taking into account the DE, leads to a value consistent with that of the global climatology by Christian et al. (2003) and other authors. Thus, a mean maximum value of about 157 fl km-2 y-1 is found for the annual lightning density. The zonal distribution of the lightning flashes exhibits a maximum between 1°S and 2°S and about 56 % of the flashes located below the equator in the 10°S - 10°N interval. The diurnal evolution of the flash rate has a maximum between 1400 and 1700 UTC, according to the reference year, in agreement with previous works in other regions of the world.

Evaluation of lens dose from anterior electron beams: comparison of Pinnacle and Gafchromic EBT3 film.

PubMed

Sonier, Marcus; Wronski, Matt; Yeboah, Collins

2015-03-08

Lens dose is a concern during the treatment of facial lesions with anterior electron beams. Lead shielding is routinely employed to reduce lens dose and minimize late complications. The purpose of this work is twofold: 1) to measure dose pro-files under large-area lead shielding at the lens depth for clinical electron energies via film dosimetry; and 2) to assess the accuracy of the Pinnacle treatment planning system in calculating doses under lead shields. First, to simulate the clinical geometry, EBT3 film and 4 cm wide lead shields were incorporated into a Solid Water phantom. With the lead shield inside the phantom, the film was positioned at a depth of 0.7 cm below the lead, while a variable thickness of solid water, simulating bolus, was placed on top. This geometry was reproduced in Pinnacle to calculate dose profiles using the pencil beam electron algorithm. The measured and calculated dose profiles were normalized to the central-axis dose maximum in a homogeneous phantom with no lead shielding. The resulting measured profiles, functions of bolus thickness and incident electron energy, can be used to estimate the lens dose under various clinical scenarios. These profiles showed a minimum lead margin of 0.5 cm beyond the lens boundary is required to shield the lens to ≤ 10% of the dose maximum. Comparisons with Pinnacle showed a consistent overestimation of dose under the lead shield with discrepancies of ~ 25% occur-ring near the shield edge. This discrepancy was found to increase with electron energy and bolus thickness and decrease with distance from the lead edge. Thus, the Pinnacle electron algorithm is not recommended for estimating lens dose in this situation. The film measurements, however, allow for a reasonable estimate of lens dose from electron beams and for clinicians to assess the lead margin required to reduce the lens dose to an acceptable level.

Method for distance determination using range-gated imaging suitable for an arbitrary pulse shape

NASA Astrophysics Data System (ADS)

Kabashnikov, Vitaly; Kuntsevich, Boris

2017-10-01

A method for distance determination with the help of range-gated viewing systems suitable for the arbitrary shape of the illumination pulse is proposed. The method is based on finding the delay time at which maximum of the return pulse energy takes place. The maximum position depends on the pulse and gate durations and, generally speaking, on the pulse shape. If the pulse length is less than or equal to the gate duration, the delay time appropriate to the maximum does not depend on the pulse shape. At equal pulse and gate durations, there is a strict local maximum, which turns into a plateau when pulse is shorter than gate duration. A delay time appropriate to the strict local maximum or the far boundary of the plateau (where non-strict maximum is) is directly related to the distance to the object. These findings are confirmed by analytical relationships for trapezoid pulses and numerical results for the real pulse shape. To verify the proposed method we used a vertical wall located at different distances from 15 to 120m as an observed object. Delay time was changing discretely in increments of 5 ns. Maximum of the signal was determined by visual observation of the object on the monitor screen. The distance defined by the proposed method coincided with the direct measurement with accuracy 1- 2m, which is comparable with the delay time step multiplied by half of the light velocity. The results can be useful in the development of 3-D vision systems.

Impact of Land Surface Initialization Approach on Subseasonal Forecast Skill: a Regional Analysis in the Southern Hemisphere

NASA Technical Reports Server (NTRS)

Hirsch, Annette L.; Kala, Jatin; Pitman, Andy J.; Carouge, Claire; Evans, Jason P.; Haverd, Vanessa; Mocko, David

2014-01-01

The authors use a sophisticated coupled land-atmosphere modeling system for a Southern Hemisphere subdomain centered over southeastern Australia to evaluate differences in simulation skill from two different land surface initialization approaches. The first approach uses equilibrated land surface states obtained from offline simulations of the land surface model, and the second uses land surface states obtained from reanalyses. The authors find that land surface initialization using prior offline simulations contribute to relative gains in subseasonal forecast skill. In particular, relative gains in forecast skill for temperature of 10%-20% within the first 30 days of the forecast can be attributed to the land surface initialization method using offline states. For precipitation there is no distinct preference for the land surface initialization method, with limited gains in forecast skill irrespective of the lead time. The authors evaluated the asymmetry between maximum and minimum temperatures and found that maximum temperatures had the largest gains in relative forecast skill, exceeding 20% in some regions. These results were statistically significant at the 98% confidence level at up to 60 days into the forecast period. For minimum temperature, using reanalyses to initialize the land surface contributed to relative gains in forecast skill, reaching 40% in parts of the domain that were statistically significant at the 98% confidence level. The contrasting impact of the land surface initialization method between maximum and minimum temperature was associated with different soil moisture coupling mechanisms. Therefore, land surface initialization from prior offline simulations does improve predictability for temperature, particularly maximum temperature, but with less obvious improvements for precipitation and minimum temperature over southeastern Australia.

Effect of NR-ANX-C (a polyherbal formulation) on haloperidol induced catalepsy in albino mice.

PubMed

Nair, Vinod; Arjuman, Albina; Dorababu, P; Gopalakrishna, H N; Chakradhar Rao, U; Mohan, Lalit

2007-11-01

Use of typical antipsychotics like haloperidol in treatment of schizophrenia is associated with a high incidence of extrapyramidal side effects. In rodents, administration of haloperidol leads to the development of a behavioural state called catalepsy, in which the animal is not able to correct an externally imposed posture. In the present study we evaluated the anticataleptic efficacy of NR-ANX-C, a polyherbal formulation containing bioactives of Withania somnifera, Ocimum sanctum, Camellia sinensis, triphala and shilajit in haloperidol induced catalepsy in mice. Five groups (n = 6) of male albino mice were used in the study. Catalepsy was induced by ip administration of haloperidol (1mg/kg). The degree of catalepsy (cataleptic score) was measured as the time the animal maintained an imposed posture. We compared the anticataleptic efficacy of NR-ANX-C (10, 25 and 50 mg/kg) with scopolamine (1 mg/kg). The superoxide dismutase (SOD) level in brain tissue was also estimated to correlate the levels of oxidative stress and degree of catalepsy in the animal. Significant (P<0.01) reduction in the cataleptic scores was observed in all NR-ANX-C treated groups and maximum reduction was observed in the NR-ANX-C (25 mg/kg) treated group. Significant (P<0.05) reduction in SOD activity was observed in NR-ANX-C (25 and 50 mg/kg) treated groups and maximum reduction was observed in NR-ANX-C (25mg/kg) treated group. In our study, maximum reduction in cataleptic score was observed in NR-ANX-C (25 mg/kg) treated group. The maximum reduction in SOD activity was also observed in the same group. These findings suggest a possible involvement of the antioxidant potential of NRANX- C in alleviating haloperidol induced catalepsy.

Potential predictability and actual skill of Boreal Summer Tropical SST and Indian summer monsoon rainfall in CFSv2-T382: Role of initial SST and teleconnections

NASA Astrophysics Data System (ADS)

Pillai, Prasanth A.; Rao, Suryachandra A.; Das, Renu S.; Salunke, Kiran; Dhakate, Ashish

2017-10-01

The present study assess the potential predictability of boreal summer (June through September, JJAS) tropical sea surface temperature (SST) and Indian summer monsoon rainfall (ISMR) using high resolution climate forecast system (CFSv2-T382) hindcasts. Potential predictability is computed using relative entropy (RE), which is the combined effect of signal strength and model spread, while the correlation between ensemble mean and observations represents the actual skill. Both actual and potential skills increase as lead time decreases for Niño3 index and equatorial East Indian Ocean (EEIO) SST anomaly and both the skills are close to each other for May IC hindcasts at zero lead. At the same time the actual skill of ISMR and El Niño Modoki index (EMI) are close to potential skill for Feb IC hindcasts (3 month lead). It is interesting to note that, both actual and potential skills are nearly equal, when RE has maximum contribution to individual year's prediction skill and its relationship with absolute error is insignificant or out of phase. The major contribution to potential predictability is from ensemble mean and the role of ensemble spread is limited for Pacific SST and ISMR hindcasts. RE values are able to capture the predictability contribution from both initial SST and simultaneous boundary forcing better than ensemble mean, resulting in higher potential skill compared to actual skill for all ICs. For Feb IC hindcasts at 3 month lead time, initial month SST (Feb SST) has important predictive component for El Niño Modoki and ISMR leading to higher value of actual skill which is close to potential skill. This study points out that even though the simultaneous relationship between ensemble mean ISMR and global SST is similar for all ICs, the predictive component from initial SST anomalies are captured well by Feb IC (3 month lead) hindcasts only. This resulted in better skill of ISMR for Feb IC (3 month lead) hindcasts compared to May IC (0 month lead) hindcasts. Lack of proper contribution from initial SST and teleconnections induces large absolute error for ISMR in May IC hindcasts resulting in very low actual skill. Thus the use of potential predictability skill and actual skill collectively help to understand the fidelity of the model for further improvement by differentiating the role of initial SST and simultaneous boundary forcing to some extent.

42 CFR 457.560 - Cumulative cost-sharing maximum.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Cumulative cost-sharing maximum. 457.560 Section... State Plan Requirements: Enrollee Financial Responsibilities § 457.560 Cumulative cost-sharing maximum... writing and orally if appropriate of their individual cumulative cost-sharing maximum amount at the time...

[Migration of eight harmful elements from household products made with synthetic resin that infants may swallow by mistake].

PubMed

Isama, Kazuo; Kawakami, Tsuyoshi; Nishimura, Tetsuji

2011-01-01

Harmful elements are used as stabilizers and colorants in synthetic resin products. Accidental ingestion of harmful elements from such synthetic resins by infants is a dangerous health hazard. The Japanese Food Sanitation Law and the International Standard ISO 8124-3 "Safety of toys-Part 3: Migration of certain elements" control the levels of migrated harmful elements, such as lead or cadmium, from infants toys. However, the levels of migrated harmful elements from household products that are not infants toys are not controlled, since they are not covered by the law or standard. Therefore, we investigated the level of eight harmful elements (antimony, arsenic, barium, cadmium, chromium, lead, mercury and selenium) migrated from household products made of synthetic resin that infants may swallow by mistake. The extraction test of ISO 8124-3: 2010 was executed in 135 products (total 150 specimens), and the concentration of these elements was measured by inductively coupled plasma mass spectroscopy (ICP-MS). As a result, 1810 mg/kg and 1660 mg/kg of lead, exceeding the maximum acceptable level of the ISO standard, migrated from two products. In addition, lead and/or chromium at levels more than 1/10 of the maximum acceptable levels of the ISO standard migrated from four products. Household products that infants may swallow by mistake should ideally not release harmful elements such as lead and chromium.

Application of Sargassum biomass to remove heavy metal ions from synthetic multi-metal solutions and urban storm water runoff.

PubMed

Vijayaraghavan, K; Teo, Ting Ting; Balasubramanian, R; Joshi, Umid Man

2009-05-30

The ability of Sargassum sp. to biosorb four metal ions, namely lead, copper, zinc, and manganese from a synthetic multi-solute system and real storm water runoff has been investigated for the first time. Experiments on synthetic multi-solute systems revealed that Sargassum performed well in the biosorption of all four metal ions, with preference towards Pb, followed by Cu, Zn, and Mn. The solution pH strongly affected the metal biosorption, with pH 6 being identified as the optimal condition for achieving maximum biosorption. Experiments at different biosorbent dosages revealed that good biosorption capacity as well as high metal removal efficiency was observed at 3g/L. The biosorption kinetics was found to be fast with equilibrium being attained within 50 min. According to the Langmuir isotherm model, Sargassum exhibited maximum uptakes of 214, 67.5, 24.2 and 20.2mg/g for lead, copper, zinc, and manganese, respectively in single-solute systems. In multi-metal systems, strong competition between four metal ions in terms of occupancy binding sites was observed, and Sargassum showed preference in the order of Pb>Cu>Zn>Mn. The application of Sargassum to remove four heavy metal ions in real storm water runoff revealed that the biomass was capable of removing the heavy metal ions. However, the biosorption performance was slightly lower compared to that of synthetic metal solutions. Several factors were responsible for this difference, and the most important factor is the presence of other contaminants such as anions, organics, and other trace metals in the runoff.

Regional-scale carbon and greenhouse gas dynamics of organic matter amendments on grassland soils

NASA Astrophysics Data System (ADS)

Mayer, A.; Silver, W. L.

2017-12-01

While progress is being made toward emissions reductions, achieving the international warming target of no more than 2 °C by 2100 will require active removal of carbon dioxide from the atmosphere. This research explores the potential for grassland ecosystems to sequester soil carbon (C) and mitigate climate change over time. We parameterized a site-level biogeochemical model (DayCent) to predict the effect of compost applications on grassland net primary productivity, greenhouse gas emissions, and soil C storage and loss. We compare the results of the DayCent model from seven grassland regions across a broad climate gradient in CA. We also modeled the impact of climate change under a high emissions scenario (RCP 8.5) and reduced emissions scenario (RCP 4.5). Model results show that a single application of compost leads to a large net increase in soil C over several decades across all sites. Maximum soil C sequestration relative to control simulations occurred approximately 15 years after a ¼ inch compost was applied to the land, resulting in a maximum net C drawdown of approximately 6.6 Mg C/ha (Mendocino) by 2030 and a continued climate benefit from enhanced C storage through the end of the century. Compost application resulted in enhanced soil C in both climate scenarios, but the reduced emissions climate scenario resulted in greater net C storage than the high emissions scenario by 2100. This points to a virtuous cycle of simultaneous emissions reductions leading to enhanced climate change mitigation potential from land management strategies.

Comparison of the clinical presentations of Naegleria fowleri primary amoebic meningoencephalitis with pneumococcal meningitis: a case-control study.

PubMed

Zahid, Mohammad Faizan; Saad Shaukat, Muhammad Hamza; Ahmed, Bilal; Beg, Mohammad Asim; Kadir, Muhammad Masood; Mahmood, Syed Faisal

2016-08-01

Primary amoebic meningoencephalitis (PAM) is a rare but fatal infection caused by Naegleria fowleri. The infection is acquired by deep nasal irrigation with infected water. Patients present with signs and symptoms similar to pneumococcal meningitis, leading to delayed diagnosis and treatment and hence high mortality. We conducted a case-control study comparing culture proven cases of PAM with pneumococcal meningitis presenting to our center between April 2008 and September 2014. Only patients with blood and/or cerebrospinal fluid cultures positive for Streptococcus pneumoniae during the same time period were included for comparison. There were 19 cases of PAM and pneumococcal meningitis, each. When comparing PAM with pneumococcal meningitis, patients with PAM were more likely to be male (89.5 vs. 36.8 %), younger (mean age: 30 vs. 59 years), present with seizures (42.1 vs. 5.3 %). Both groups of patients presented with similar vital signs and there were no remarkable differences on physical examinations, Glasgow Coma Scale scores, laboratory and radiological investigations and cerebrospinal fluid parameters. PAM was also more likely to present if the city's average maximum temperature was higher in the previous week (mean: 34.6 vs. 30 °C). There was history of fresh water contact in only one patient. On multivariate analysis, PAM was more likely if patients presented when the city's average maximum temperature was high, being young males. PAM and pneumococcal meningitis remain virtually indistinguishable; however, these predictive features should be validated in a prospective study and may lead to a viable algorithm for early management of these patients.

Seasonal forecasting of high wind speeds over Western Europe

NASA Astrophysics Data System (ADS)

Palutikof, J. P.; Holt, T.

2003-04-01

As financial losses associated with extreme weather events escalate, there is interest from end users in the forestry and insurance industries, for example, in the development of seasonal forecasting models with a long lead time. This study uses exceedences of the 90th, 95th, and 99th percentiles of daily maximum wind speed over the period 1958 to present to derive predictands of winter wind extremes. The source data is the 6-hourly NCEP Reanalysis gridded surface wind field. Predictor variables include principal components of Atlantic sea surface temperature and several indices of climate variability, including the NAO and SOI. Lead times of up to a year are considered, in monthly increments. Three regression techniques are evaluated; multiple linear regression (MLR), principal component regression (PCR), and partial least squares regression (PLS). PCR and PLS proved considerably superior to MLR with much lower standard errors. PLS was chosen to formulate the predictive model since it offers more flexibility in experimental design and gave slightly better results than PCR. The results indicate that winter windiness can be predicted with considerable skill one year ahead for much of coastal Europe, but that this deteriorates rapidly in the hinterland. The experiment succeeded in highlighting PLS as a very useful method for developing more precise forecasting models, and in identifying areas of high predictability.