Fault Analysis and Detection in Microgrids with High PV Penetration

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

El Khatib, Mohamed; Hernandez Alvidrez, Javier; Ellis, Abraham

In this report we focus on analyzing current-controlled PV inverters behaviour under faults in order to develop fault detection schemes for microgrids with high PV penetration. Inverter model suitable for steady state fault studies is presented and the impact of PV inverters on two protection elements is analyzed. The studied protection elements are superimposed quantities based directional element and negative sequence directional element. Additionally, several non-overcurrent fault detection schemes are discussed in this report for microgrids with high PV penetration. A detailed time-domain simulation study is presented to assess the performance of the presented fault detection schemes under different microgridmore » modes of operation.« less

A study of the mechanisms by which the cercariae of Microphallus primas (Jag, 1909) Stunkard, 1957 penetrate the shore crab, Carcinus maenas (L).

PubMed

Saville, D H; Irwin, S W B

2005-10-01

This study established the mechanisms by which Microphallus primas cercariae penetrate the crab Carcinus maenas in which they form metacercarial cysts. Light and electron microscopy were used to investigate cercarial features and to follow the fate of cercariae released in close proximity to crabs. It was shown that cercariae were carried in respiratory currents into crabs' branchial chambers where each enveloped itself in a transparent penetration cyst on the gill lamellae. When cercariae were present the number of respiratory current reversals performed by crabs increased. Using an 'artificial branchial chamber' it was possible to observe how cercariae attached to crab gills during breaks in current flow that preceded each current reversal. Inside the penetration cysts the now tail-less larvae used their stylets to pierce holes through which they levered themselves into underlying haemolymph channels in the gills. Histochemical tests demonstrated that the penetration cysts were products of glands in the cercariae and that penetration of the crabs was achieved by mechanical means. The importance of crab respiratory current reversals to the success of cercarial penetration is discussed as it represents the exploitation by a parasite of a host behavioural response to an unrelated stimulus.

Response of the Equatorial Ionosphere to the Geomagnetic DP 2 Current System

NASA Technical Reports Server (NTRS)

Yizengaw, E.; Moldwin, M. B.; Zesta, E.; Magoun, M.; Pradipta, R.; Biouele, C. M.; Rabiu, A. B.; Obrou, O. K.; Bamba, Z.; Paula, E. R. De

2016-01-01

The response of equatorial ionosphere to the magnetospheric origin DP 2 current system fluctuations is examined using ground-based multiinstrument observations. The interaction between the solar wind and fluctuations of the interplanetary magnetic field (IMF) Bz, penetrates nearly instantaneously to the dayside equatorial region at all longitudes and modulates the electrodynamics that governs the equatorial density distributions. In this paper, using magnetometers at high and equatorial latitudes, we demonstrate that the quasiperiodic DP 2 current system penetrates to the equator and causes the dayside equatorial electrojet (EEJ) and the independently measured ionospheric drift velocity to fluctuate coherently with the high-latitude DP 2 current as well as with the IMF Bz component. At the same time, radar observations show that the ionospheric density layers move up and down, causing the density to fluctuate up and down coherently with the EEJ and IMF Bz.

Penetration and pharmacokinetics of non-steroidal anti-inflammatory drugs in rat prostate tissue.

PubMed

Yellepeddi, Venkata K; Radhakrishnan, Jayashree; Radhakrishnan, Rajan

2018-02-01

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) involves inflammation of the prostate and affects the quality of life of men of all ages. It is well reported in clinical studies that the treatment for CP/CPPS using nonsteroidal anti-inflammatory drugs (NSAIDs) produced favorable outcomes. However, currently, there are no guidelines on choice of the NSAIDs for the treatment of CP/CPPS. Therefore, in the current research study, we evaluated the prostate tissue penetration of four NSAIDs in rats to provide guidance on choice of NSAIDs for the treatment of CP/CPPS. Male Sprague-Dawley rats were administered orally with four NSAIDs viz. celecoxib, diclofenac, ibuprofen, and naproxen at 500 mg/kg dose. The animals were then sacrificed at various time points, and their prostate tissues were harvested. The NSAIDs were then extracted from the prostate tissues using liquid extraction technique, and their concentration in prostate tissue was quantified using high-performance liquid chromatography (HPLC). The prostate tissue penetration and related pharmacokinetic parameters were evaluated by non-compartmental analysis. The HPLC method for quantifying NSAIDs in prostate tissue resulted in single, sharp peaks without any interference and all validation parameters were within limits. Celecoxib showed the highest area under the curve (AUC) [146.50 ± 2.75 μg/mL*h] of all NSAID's. A two-factor analysis of variance (ANOVA) with replication indicated an overall statistically significant difference in the pharmacokinetic parameters for celecoxib, diclofenac, ibuprofen, and naproxen. This study for the first time reported the relative prostate tissue penetration of four NSAIDs. The pharmacokinetic data indicated that celecoxib has the highest penetration and retention in rat prostate tissues. Therefore, celecoxib may be considered as a better choice for the treatment CP/CPPS involving NSAIDs. © 2017 Wiley Periodicals, Inc.

Exploring infrared sensoring for real time welding defects monitoring in GTAW.

PubMed

Alfaro, Sadek C A; Franco, Fernand Díaz

2010-01-01

This paper presents an evaluation of an infrared sensor for monitoring the welding pool temperature in a Gas Tungsten Arc Welding (GTAW) process. The purpose of the study is to develop a real time system control. It is known that the arc welding pool temperature is related to the weld penetration depth; therefore, by monitoring the temperature, the arc pool temperature and penetration depth are also monitored. Various experiments were performed; in some of them the current was varied and the temperature changes were registered, in others, defects were induced throughout the path of the weld bead for a fixed current. These simulated defects resulted in abrupt changes in the average temperature values, thus providing an indication of the presence of a defect. The data has been registered with an acquisition card. To identify defects in the samples under infrared emissions, the timing series were analyzed through graphics and statistic methods. The selection of this technique demonstrates the potential for infrared emission as a welding monitoring parameter sensor.

Exploring Infrared Sensoring for Real Time Welding Defects Monitoring in GTAW

PubMed Central

Alfaro, Sadek C. A.; Franco, Fernand Díaz

2010-01-01

This paper presents an evaluation of an infrared sensor for monitoring the welding pool temperature in a Gas Tungsten Arc Welding (GTAW) process. The purpose of the study is to develop a real time system control. It is known that the arc welding pool temperature is related to the weld penetration depth; therefore, by monitoring the temperature, the arc pool temperature and penetration depth are also monitored. Various experiments were performed; in some of them the current was varied and the temperature changes were registered, in others, defects were induced throughout the path of the weld bead for a fixed current. These simulated defects resulted in abrupt changes in the average temperature values, thus providing an indication of the presence of a defect. The data has been registered with an acquisition card. To identify defects in the samples under infrared emissions, the timing series were analyzed through graphics and statistic methods. The selection of this technique demonstrates the potential for infrared emission as a welding monitoring parameter sensor. PMID:22219697

Solving time-dependent two-dimensional eddy current problems

NASA Technical Reports Server (NTRS)

Lee, Min Eig; Hariharan, S. I.; Ida, Nathan

1990-01-01

Transient eddy current calculations are presented for an EM wave-scattering and field-penetrating case in which a two-dimensional transverse magnetic field is incident on a good (i.e., not perfect) and infinitely long conductor. The problem thus posed is of initial boundary-value interface type, where the boundary of the conductor constitutes the interface. A potential function is used for time-domain modeling of the situation, and finite difference-time domain techniques are used to march the potential function explicitly in time. Attention is given to the case of LF radiation conditions.

Method for determining transport critical current densities and flux penetration depth in bulk superconductors

NASA Technical Reports Server (NTRS)

Israelsson, Ulf E. (Inventor); Strayer, Donald M. (Inventor)

1992-01-01

A contact-less method for determining transport critical current density and flux penetration depth in bulk superconductor material. A compressor having a hollow interior and a plunger for selectively reducing the free space area for distribution of the magnetic flux therein are formed of superconductor material. Analytical relationships, based upon the critical state model, Maxwell's equations and geometrical relationships define transport critical current density and flux penetration depth in terms of the initial trapped magnetic flux density and the ratio between initial and final magnetic flux densities whereby data may be reliably determined by means of the simple test apparatus for evaluating the current density and flux penetration depth.

Axial magnetic field injection in magnetized liner inertial fusion

NASA Astrophysics Data System (ADS)

Gourdain, P.-A.; Adams, M. B.; Davies, J. R.; Seyler, C. E.

2017-10-01

MagLIF is a fusion concept using a Z-pinch implosion to reach thermonuclear fusion. In current experiments, the implosion is driven by the Z-machine using 19 MA of electrical current with a rise time of 100 ns. MagLIF requires an initial axial magnetic field of 30 T to reduce heat losses to the liner wall during compression and to confine alpha particles during fusion burn. This field is generated well before the current ramp starts and needs to penetrate the transmission lines of the pulsed-power generator, as well as the liner itself. Consequently, the axial field rise time must exceed hundreds of microseconds. Any coil capable of being submitted to such a field for that length of time is inevitably bulky. The space required to fit the coil near the liner, increases the inductance of the load. In turn, the total current delivered to the load decreases since the voltage is limited by driver design. Yet, the large amount of current provided by the Z-machine can be used to produce the required 30 T field by tilting the return current posts surrounding the liner, eliminating the need for a separate coil. However, the problem now is the field penetration time, across the liner wall. This paper discusses why skin effect arguments do not hold in the presence of resistivity gradients. Numerical simulations show that fields larger than 30 T can diffuse across the liner wall in less than 60 ns, demonstrating that external coils can be replaced by return current posts with optimal helicity.

Utilization management in radiology, part 1: rationale, history, and current status.

PubMed

Duszak, Richard; Berlin, Jonathan W

2012-10-01

Previous growth in the utilization of medical imaging has led to numerous efforts to reduce associated spending. Although these have historically been directed toward unit cost reductions, recent interest has emerged by various stakeholders in curbing inappropriate utilization. Radiology benefits managers have widespread market penetration and have been promoted largely by the payer community as effective mechanisms to curb increases in imaging volume. The provider community has tended to favor real-time order entry decision support systems. These have demonstrated comparable effectiveness to radiology benefits managers in early projects but currently have only limited market penetration. In this first of a two-part series, the rationale for the development of utilization management programs will be discussed and their history and current status reviewed. Copyright © 2012 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Cell dialysis by sharp electrodes can cause nonphysiological changes in neuron properties

PubMed Central

Hooper, Scott L.; Guschlbauer, Christoph; Schmidt, Joachim; Büschges, Ansgar

2015-01-01

We recorded from lobster and leech neurons with two sharp electrodes filled with solutions often used with these preparations (lobster: 0.6 M K2SO4 or 2.5 M KAc; leech: 4 M KAc), with solutions approximately matching neuron cytoplasm ion concentrations, and with 6.5 M KAc (lobster, leech) and 0.6 M KAc (lobster). We measured membrane potential, input resistance, and transient and sustained depolarization-activated outward current amplitudes in leech and these neuron properties and hyperpolarization-activated current time constant in lobster, every 10 min for 60 min after electrode penetration. Neuron properties varied with electrode fill. For fills with molarities ≥2.5 M, neuron properties also varied strongly with time after electrode penetration. Depending on the property being examined, these variations could be large. In leech, cell size also increased with noncytoplasmic fills. The changes in neuron properties could be due to the ions being injected from the electrodes during current injection. We tested this possibility in lobster with the 2.5 M KAc electrode fill by making measurements only 10 and 60 min after penetration. Neuron properties still changed, although the changes were less extreme. Making measurements every 2 min showed that the time-dependent variations in neuron properties occurred in concert with each other. Neuron property changes with high molarity electrode-fill solutions were great enough to decrease neuron firing strongly. An experiment with 14C-glucose electrode fill confirmed earlier work showing substantial leak from sharp electrodes. Sharp electrode work should thus be performed with cytoplasm-matched electrode fills. PMID:26063785

Cell dialysis by sharp electrodes can cause nonphysiological changes in neuron properties.

PubMed

Hooper, Scott L; Thuma, Jeffrey B; Guschlbauer, Christoph; Schmidt, Joachim; Büschges, Ansgar

2015-08-01

We recorded from lobster and leech neurons with two sharp electrodes filled with solutions often used with these preparations (lobster: 0.6 M K2SO4 or 2.5 M KAc; leech: 4 M KAc), with solutions approximately matching neuron cytoplasm ion concentrations, and with 6.5 M KAc (lobster, leech) and 0.6 M KAc (lobster). We measured membrane potential, input resistance, and transient and sustained depolarization-activated outward current amplitudes in leech and these neuron properties and hyperpolarization-activated current time constant in lobster, every 10 min for 60 min after electrode penetration. Neuron properties varied with electrode fill. For fills with molarities ≥2.5 M, neuron properties also varied strongly with time after electrode penetration. Depending on the property being examined, these variations could be large. In leech, cell size also increased with noncytoplasmic fills. The changes in neuron properties could be due to the ions being injected from the electrodes during current injection. We tested this possibility in lobster with the 2.5 M KAc electrode fill by making measurements only 10 and 60 min after penetration. Neuron properties still changed, although the changes were less extreme. Making measurements every 2 min showed that the time-dependent variations in neuron properties occurred in concert with each other. Neuron property changes with high molarity electrode-fill solutions were great enough to decrease neuron firing strongly. An experiment with (14)C-glucose electrode fill confirmed earlier work showing substantial leak from sharp electrodes. Sharp electrode work should thus be performed with cytoplasm-matched electrode fills. Copyright © 2015 the American Physiological Society.

Sexual Assault Characteristics and Perceptions of Event-Related Distress.

PubMed

Blayney, Jessica A; Read, Jennifer P

2018-04-01

Sexual assault (SA) is a potent psychological stressor, linked to harmful mental health outcomes in both the short- and long-term. Specific assault characteristics can add to the toxicity of SA events. Although research has assessed characteristics of the assault itself (e.g., force, penetration), few studies have examined the larger socioenvironmental context in which SA takes place. This was the purpose of the present study. Young adults ( N = 220; 80% female; 54% current students) reported on their most recent SA during college. Cross-sectional associations were tested via structural equation modeling to determine the contributions of socioenvironmental context and assault characteristics in predicting event-related distress. Socioenvironmental context from the most recent assault included assault setting, intoxication at the time of the assault, perpetrator relationship, and prior consensual sexual experiences with the perpetrator. We also examined assault characteristics, including physical force and penetration. Participants reported how upsetting the most recent assault was (a) at the time it occurred and (b) currently. Results revealed differential patterns for socioenvironmental context and assault characteristics based on the timing of distress (past or present). Notably, many of the socioenvironmental factors showed associations with distress above and beyond the powerful effects of physical force and penetration. These findings have important implications for our understanding of the unique factors that contribute to and maintain psychological distress in sexually victimized young adults.

Evaluation of consolidation characteristics of cohesive soils from piezocone penetration tests : technical summary.

DOT National Transportation Integrated Search

2004-07-01

The main objective of this study was to evaluate the current interpretation methods for their capability to reasonably predict the consolidation parameters needed to estimate the magnitude and time rate of consolidation settlement in fine-grained soi...

In-vivo dynamic characterization of microneedle skin penetration using optical coherence tomography

NASA Astrophysics Data System (ADS)

Enfield, Joey; O'Connell, Marie-Louise; Lawlor, Kate; Jonathan, Enock; O'Mahony, Conor; Leahy, Martin

2010-07-01

The use of microneedles as a method of circumventing the barrier properties of the stratum corneum is receiving much attention. Although skin disruption technologies and subsequent transdermal diffusion rates are being extensively studied, no accurate data on depth and closure kinetics of microneedle-induced skin pores are available, primarily due to the cumbersome techniques currently required for skin analysis. We report on the first use of optical coherence tomography technology to image microneedle penetration in real time and in vivo. We show that optical coherence tomography (OCT) can be used to painlessly measure stratum corneum and epidermis thickness, as well as microneedle penetration depth after microneedle insertion. Since OCT is a real-time, in-vivo, nondestructive technique, we also analyze skin healing characteristics and present quantitative data on micropore closure rate. Two locations (the volar forearm and dorsal aspect of the fingertip) have been assessed as suitable candidates for microneedle administration. The results illustrate the applicability of OCT analysis as a tool for microneedle-related skin characterization.

Measurements of the toroidal torque balance of error field penetration locked modes

DOE PAGES

Shiraki, Daisuke; Paz-Soldan, Carlos; Hanson, Jeremy M.; ...

2015-01-05

Here, detailed measurements from the DIII-D tokamak of the toroidal dynamics of error field penetration locked modes under the influence of slowly evolving external fields, enable study of the toroidal torques on the mode, including interaction with the intrinsic error field. The error field in these low density Ohmic discharges is well known based on the mode penetration threshold, allowing resonant and non-resonant torque effects to be distinguished. These m/n = 2/1 locked modes are found to be well described by a toroidal torque balance between the resonant interaction with n = 1 error fields, and a viscous torque inmore » the electron diamagnetic drift direction which is observed to scale as the square of the perturbed field due to the island. Fitting to this empirical torque balance allows a time-resolved measurement of the intrinsic error field of the device, providing evidence for a time-dependent error field in DIII-D due to ramping of the Ohmic coil current.« less

Effects of egg shell quality and washing on Salmonella Infantis penetration.

PubMed

Samiullah; Chousalkar, K K; Roberts, J R; Sexton, M; May, D; Kiermeier, A

2013-07-15

The vast majority of eggs in Australia are washed prior to packing to remove dirt and fecal material and to reduce the microbial contamination of the egg shell. The egg contents can be an ideal growth medium for microorganisms which can result in human illness if eggs are stored improperly and eaten raw or undercooked, and it is estimated that egg-related salmonellosis is costing Australia $44 million per year. Egg shell characteristics such as shell thickness, amount of cuticle present, and thickness of individual egg shell layers can affect the ease with which bacteria can penetrate the egg shell and washing could partially or completely remove the cuticle layer. The current study was conducted to investigate the effects of egg washing on cuticle cover and effects of egg shell quality and cuticle cover on Salmonella Infantis penetration of the egg shell. A higher incidence of unfavorable ultrastructural variables of the mammillary layer such as late fusion, type B bodies, type A bodies, poor cap quality, alignment, depression, erosion and cubics were recorded in Salmonella penetrated areas of egg shells. The influence of egg washing on the ability of Salmonella Infantis on the egg shell surface to enter the egg internal contents was also investigated using culture-based agar egg penetration and real-time qPCR based experiments. The results from the current study indicate that washing affected cuticle cover. There were no significant differences in Salmonella Infantis penetration of washed or unwashed eggs. Egg shell translucency may have effects on Salmonella Infantis penetration of the egg shell. The qPCR assay was more sensitive for detection of Salmonella Infantis from egg shell wash and internal contents than traditional microbiological methods. The agar egg and whole egg inoculation experiments indicated that Salmonella Infantis penetrated the egg shells. Egg washing not only can be highly effective at removing Salmonella Infantis from the egg shell surface, but also allows subsequent trans-shell and trans-membrane penetration into the egg. Consequently, it is important to prevent recontamination of the egg after washing. Copyright © 2013 Elsevier B.V. All rights reserved.

78 FR 27005 - Airworthiness Directives; Revo, Incorporated Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-09

.... That AD currently requires a one-time, dye-penetrant inspection of the horizontal stabilizer attachment... from Revo, Incorporated that, while the drawing numbers are different, the attachment fittings on the... FAA, Small Airplane Directorate, 901 Locust St., Kansas City, Missouri 64106. For information on the...

Prophylactic antibiotics for penetrating abdominal trauma.

PubMed

Brand, Martin; Grieve, Andrew

2013-11-18

Penetrating abdominal trauma occurs when the peritoneal cavity is breached. Routine laparotomy for penetrating abdominal injuries began in the 1800s, with antibiotics first being used in World War II to combat septic complications associated with these injuries. This practice was marked with a reduction in sepsis-related mortality and morbidity. Whether prophylactic antibiotics are required in the prevention of infective complications following penetrating abdominal trauma is controversial, however, as no randomised placebo controlled trials have been published to date. There has also been debate about the timing of antibiotic prophylaxis. In 1972 Fullen noted a 7% to 11% post-surgical infection rate with pre-operative antibiotics, a 33% to 57% infection rate with intra-operative antibiotic administration and 30% to 70% infection rate with only post-operative antibiotic administration. Current guidelines state there is sufficient class I evidence to support the use of a single pre-operative broad spectrum antibiotic dose, with aerobic and anaerobic cover, and continuation (up to 24 hours) only in the event of a hollow viscus perforation found at exploratory laparotomy. To assess the benefits and harms of prophylactic antibiotics administered for penetrating abdominal injuries for the reduction of the incidence of septic complications, such as septicaemia, intra-abdominal abscesses and wound infections. Searches were not restricted by date, language or publication status. We searched the following electronic databases: the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library 2013, issue 12 of 12), MEDLINE (OvidSP), Embase (OvidSP), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED), ISI Web of Science: Conference Proceedings Citation Index- Science (CPCI-S) and PubMed. Searches were last conducted in January 2013. All randomised controlled trials of antibiotic prophylaxis in patients with penetrating abdominal trauma versus no antibiotics or placebo. Two authors screened the literature search results independently. We identified no trials meeting the inclusion criteria. There is currently no information from randomised controlled trials to support or refute the use of antibiotics for patients with penetrating abdominal trauma.

Intensified treatment with high dose Rifampicin and Levofloxacin compared to standard treatment for adult patients with Tuberculous Meningitis (TBM-IT): protocol for a randomized controlled trial

PubMed Central

2011-01-01

Background Tuberculous meningitis is the most severe form of tuberculosis. Mortality for untreated tuberculous meningitis is 100%. Despite the introduction of antibiotic treatment for tuberculosis the mortality rate for tuberculous meningitis remains high; approximately 25% for HIV-negative and 67% for HIV positive patients with most deaths occurring within one month of starting therapy. The high mortality rate in tuberculous meningitis reflects the severity of the condition but also the poor antibacterial activity of current treatment regimes and relatively poor penetration of these drugs into the central nervous system. Improving the antitubercular activity in the central nervous system of current therapy may help improve outcomes. Increasing the dose of rifampicin, a key drug with known poor cerebrospinal fluid penetration may lead to higher drug levels at the site of infection and may improve survival. Of the second generation fluoroquinolones, levofloxacin may have the optimal pharmacological features including cerebrospinal fluid penetration, with a ratio of Area Under the Curve (AUC) in cerebrospinal fluid to AUC in plasma of >75% and strong bactericidal activity against Mycobacterium tuberculosis. We propose a randomized controlled trial to assess the efficacy of an intensified anti-tubercular treatment regimen in tuberculous meningitis patients, comparing current standard tuberculous meningitis treatment regimens with standard treatment intensified with high-dose rifampicin and additional levofloxacin. Methods/Design A randomized, double blind, placebo-controlled trial with two parallel arms, comparing standard Vietnamese national guideline treatment for tuberculous meningitis with standard treatment plus an increased dose of rifampicin (to 15 mg/kg/day total) and additional levofloxacin. The study will include 750 patients (375 per treatment group) including a minimum of 350 HIV-positive patients. The calculation assumes an overall mortality of 40% vs. 30% in the two arms, respectively (corresponding to a target hazard ratio of 0.7), a power of 80% and a two-sided significance level of 5%. Randomization ratio is 1:1. The primary endpoint is overall survival, i.e. time from randomization to death during a follow-up period of 9 months. Secondary endpoints are: neurological disability at 9 months, time to new neurological event or death, time to new or recurrent AIDS-defining illness or death (in HIV-positive patients only), severe adverse events, and rate of treatment interruption for adverse events. Discussion Currently very few options are available for the treatment of TBM and the mortality rate remains unacceptably high with severe disabilities seen in many of the survivors. This trial is based on the hypothesis that current anti-mycobacterial treatment schedules for TBM are not potent enough and that outcomes will be improved by increasing the CSF penetrating power of this regimen by optimising dosage and using additional drugs with better CSF penetration. Trial registration International Standard Randomised Controlled Trial Number ISRCTN61649292 PMID:21288325

Intensified treatment with high dose rifampicin and levofloxacin compared to standard treatment for adult patients with tuberculous meningitis (TBM-IT): protocol for a randomized controlled trial.

PubMed

Heemskerk, Dorothee; Day, Jeremy; Chau, Tran Thi Hong; Dung, Nguyen Huy; Yen, Nguyen Thi Bich; Bang, Nguyen Duc; Merson, Laura; Olliaro, Piero; Pouplin, Thomas; Caws, Maxine; Wolbers, Marcel; Farrar, Jeremy

2011-02-02

Tuberculous meningitis is the most severe form of tuberculosis. Mortality for untreated tuberculous meningitis is 100%. Despite the introduction of antibiotic treatment for tuberculosis the mortality rate for tuberculous meningitis remains high; approximately 25% for HIV-negative and 67% for HIV positive patients with most deaths occurring within one month of starting therapy. The high mortality rate in tuberculous meningitis reflects the severity of the condition but also the poor antibacterial activity of current treatment regimes and relatively poor penetration of these drugs into the central nervous system. Improving the antitubercular activity in the central nervous system of current therapy may help improve outcomes. Increasing the dose of rifampicin, a key drug with known poor cerebrospinal fluid penetration may lead to higher drug levels at the site of infection and may improve survival. Of the second generation fluoroquinolones, levofloxacin may have the optimal pharmacological features including cerebrospinal fluid penetration, with a ratio of Area Under the Curve (AUC) in cerebrospinal fluid to AUC in plasma of >75% and strong bactericidal activity against Mycobacterium tuberculosis. We propose a randomized controlled trial to assess the efficacy of an intensified anti-tubercular treatment regimen in tuberculous meningitis patients, comparing current standard tuberculous meningitis treatment regimens with standard treatment intensified with high-dose rifampicin and additional levofloxacin. A randomized, double blind, placebo-controlled trial with two parallel arms, comparing standard Vietnamese national guideline treatment for tuberculous meningitis with standard treatment plus an increased dose of rifampicin (to 15 mg/kg/day total) and additional levofloxacin. The study will include 750 patients (375 per treatment group) including a minimum of 350 HIV-positive patients. The calculation assumes an overall mortality of 40% vs. 30% in the two arms, respectively (corresponding to a target hazard ratio of 0.7), a power of 80% and a two-sided significance level of 5%. Randomization ratio is 1:1. The primary endpoint is overall survival, i.e. time from randomization to death during a follow-up period of 9 months. Secondary endpoints are: neurological disability at 9 months, time to new neurological event or death, time to new or recurrent AIDS-defining illness or death (in HIV-positive patients only), severe adverse events, and rate of treatment interruption for adverse events. Currently very few options are available for the treatment of TBM and the mortality rate remains unacceptably high with severe disabilities seen in many of the survivors. This trial is based on the hypothesis that current anti-mycobacterial treatment schedules for TBM are not potent enough and that outcomes will be improved by increasing the CSF penetrating power of this regimen by optimising dosage and using additional drugs with better CSF penetration. International Standard Randomised Controlled Trial Number ISRCTN61649292.

Energy and Mass Transport of Magnetospheric Plasmas during the November 2003 Magnetic Storm

NASA Technical Reports Server (NTRS)

Fok, Mei-Chging; Moore, Thomas

2008-01-01

Intensive energy and mass transport from the solar wind across the magnetosphere boundary is a trigger of magnetic storms. The storm on 20-21 November 2003 was elicited by a high-speed solar wind and strong southward component of interplanetary magnetic field. This storm attained a minimum Dst of -422 nT. During the storm, some of the solar wind particles enter the magnetosphere and eventually become part of the ring current. At the same time, the fierce solar wind powers strong outflow of H+ and O+ from the ionosphere, as well as from the plasmasphere. We examine the contribution of plasmas from the solar wind, ionosphere and plasmasphere to the storm-time ring current. Our simulation shows, for this particular storm, ionospheric O+ and solar wind ions are the major sources of the ring current particles. The polar wind and plasmaspheric H+ have only minor impacts. In the storm main phase, the strong penetration of solar wind electric field pushes ions from the geosynchronous orbit to L shells of 2 and below. Ring current is greatly intensified during the earthward transport and produces a large magnetic depression in the surface field. When the convection subsides, the deep penetrating ions experience strong charge exchange loss, causing rapid decay of the ring current and fast initial storm recovery. Our simulation reproduces very well the storm development indicated by the Dst index.

Penetrative convection

NASA Technical Reports Server (NTRS)

Moore, D. R.

1981-01-01

The current state of understanding of the most directly observable solar convection, the granulation and supergranulation is summarized. The body of work in which the complete time dependent Navier-Stokes equations and entropy transport equation are solved for a fully compressible atmosphere is considered. Relevant anelastic and incompressible calculations in two dimensions are also discussed.

Course of serum amyloid A (SAA) plasma concentrations in horses undergoing surgery for injuries penetrating synovial structures, an observational clinical study.

PubMed

Haltmayer, Eva; Schwendenwein, Ilse; Licka, Theresia F

2017-05-22

Injuries penetrating synovial structures are common in equine practice and often result in septic synovitis. Significantly increased plasma levels of serum amyloid A (SAA) have been found in various infectious conditions in horses including wounds and septic arthritis. Plasma SAA levels were found to decrease rapidly once the infectious stimulus was eliminated. The purpose of the current study was to investigate the usefulness of serial measurements of plasma SAA as a monitoring tool for the response to treatment of horses presented with injuries penetrating synovial structures. In the current study plasma SAA concentrations were measured every 48 hours (h) during the course of treatment. A total of 19 horses with a wound penetrating a synovial structure were included in the current study. Horses in Group 1 (n = 12) (injuries older than 24 h) only needed one surgical intervention. Patients in this group had significantly lower median plasma SAA levels (P = 0.001) between 48 h (median 776 mg/L) and 96 h (median 202 mg/L) after surgery. A significant decrease (P = 0.004) in plasma SAA levels was also observed between 96 h after surgery (median 270 mg/L) and 6 days (d) after surgery (median 3 mg/L). Four horses (Group 2) required more than one surgical intervention. In contrast to Group 1 patients in Group 2 had either very high initial plasma concentrations (3378 mg/L), an increase or persistently high concentrations of plasma SAA after the first surgery (median 2525 mg/L). A small group of patients (n = 3) (Group 3) were admitted less than 24 h after sustaining a wound. In this group low SAA values at admission (median 23 mg/L) and peak concentrations at 48 h after surgery (median 1016 mg/L) were observed followed by a decrease in plasma SAA concentration over time. A decrease in plasma SAA concentrations between two consecutive time points could be associated with positive response to treatment in the current study. Therefore, serial measurements of plasma SAA could potentially be used as an additional inexpensive, quick and easy tool for monitoring the treatment response in otherwise healthy horses presented with injuries penetrating synovial structures. However further studies will be necessary to ascertain its clinical utility.

Penetrator role in Mars sample strategy

NASA Technical Reports Server (NTRS)

Boynton, William; Dwornik, Steve; Eckstrom, William; Roalstad, David A.

1988-01-01

The application of the penetrator to a Mars Return Sample Mission (MRSM) has direct advantages to meet science objectives and mission safety. Based on engineering data and work currently conducted at Ball Aerospace Systems Division, the concept of penetrators as scientific instruments is entirely practical. The primary utilization of a penetrator for MRSM would be to optimize the selection of the sample site location and to help in selection of the actual sample to be returned to Earth. It is recognized that the amount of sample to be returned is very limited, therefore the selection of the sample site is critical to the success of the mission. The following mission scenario is proposed. The site selection of a sample to be acquired will be performed by science working groups. A decision will be reached and a set of target priorities established based on data to give geochemical, geophysical and geological information. The first task of a penetrator will be to collect data at up to 4 to 6 possible landing sites. The penetrator can include geophysical, geochemical, geological and engineering instruments to confirm that scientific data requirements at that site will be met. This in situ near real-time data, collected prior to final targeting of the lander, will insure that the sample site is both scientifically valuable and also that it is reachable within limits of the capability of the lander.

A flowing partially penetrating well in a finite-thickness aquifer: a mixed-type initial boundary value problem

NASA Astrophysics Data System (ADS)

Chang, Chien-Chieh; Chen, Chia-Shyun

2003-02-01

An analytical approach using integral transform techniques is developed to deal with a well hydraulics model involving a mixed boundary of a flowing partially penetrating well, where constant drawdown is stipulated along the well screen and no-flux condition along the remaining unscreened part. The aquifer is confined of finite thickness. First, the mixed boundary is changed into a homogeneous Neumann boundary by discretizing the well screen into a finite number of segments, each of which at constant drawdown is subject to unknown a priori well bore flux. Then, the Laplace and the finite Fourier transforms are used to solve this modified model. Finally, the prescribed constant drawdown condition is reinstated to uniquely determine the well bore flux function, and to restore the relation between the solution and the original model. The transient and the steady-state solutions for infinite aquifer thickness can be derived from the semi-analytical solution, complementing the currently available dual integral solution. If the distance from the edge of the well screen to the bottom/top of the aquifer is 100 times greater than the well screen length, aquifer thickness can be assumed infinite for times of practical significance, and groundwater flow can reach a steady-state condition, where the well will continuously supply water under a constant discharge. However, if aquifer thickness is smaller, the well discharge decreases with time. The partial penetration effect is most pronounced in the vicinity of the flowing well, decreases with increasing horizontal distance, and vanishes at distances larger than 1-2 times the aquifer thickness divided by the square root of aquifer anisotropy. The horizontal hydraulic conductivity and the specific storage coefficient can be determined from vertically averaged drawdown as measured by fully penetrating observation wells. The vertical hydraulic conductivity can be determined from the well discharge under two particular partial penetration conditions.

Improving Forest Wildfire Suppression Using Penetrating Reconnaissance And Real Time Data Transfer

NASA Astrophysics Data System (ADS)

Greer, Jerry D.

1990-02-01

The suppression of a wildfire is analogous to a combat action. Fires, like battles, spread fast and suppression forces must be highly mobile. The enemy, (in this case) the wildfire, is lethal in that it kills or destroys forces, equipment, and natural resources left in its path. The suppression action must be carried on day and night until the "enemy" is contained. Both air operations and ground forces are used. Just as in a combat situation, wildfire suppression forces need penetrating reconnaissance with real time data transfer. This paper presents a review of the current system of intelligence gathering on a wildfire where aerial observers, infrared detectors, and ground intelligence officers gather data and either radio or carry the data to the command center. It then attempts to show how some current military reconnaissance systems might be applied to wildfire control processes. The payoffs would include improved safety for both air and ground forces and faster containment of the wildfire which would reduce forest resources lost and decrease the total monetary cost of the containment action.

Study of Proton cutoffs during geomagnetically disturbed times

NASA Astrophysics Data System (ADS)

Kanekal, S. G.; Looper, M. D.; Baker, D. N.; Blake, J. B.

2005-12-01

It is currently believed that solar energetic particles (SEP) may be accelerated at solar flares and/or at interplanetary shocks driven by coronal mass ejections (CMEs). CMEs also cause intense geomagnetic storms during which the geomagnetic field can be highly distorted.SEP fluxes penetrate the terrestrial magnetosphere and reach specific regions depending upon the geomagnetic field configuration. The cutoff latitude is a well defined latitude below which a charged particle of a given rigidity (momentum per unit charge) arriving from a given direction cannot penetrate. SEP cutoff location can therefore be potentially useful in determining the geomagnetic field configuration. This paper reports on the measurements of solar energetic proton cutoffs made by two satellites, SAMPEX and Polar during geomagnetically disturbed times. We study select SEP events and compare our measurements with cutoffs calculated by a charged particle tracing code which utilizes several currently used models of the geomagnetic field. The measured SEP proton cutoffs cover a wide range of rigidities and are obtained at high-altitudes by the HIST detector onboard Polar and at low-altitudes by the PET detctor onboard SAMPEX.

Imaging the delivery of brain-penetrating PLGA nanoparticles in the brain using magnetic resonance.

PubMed

Strohbehn, Garth; Coman, Daniel; Han, Liang; Ragheb, Ragy R T; Fahmy, Tarek M; Huttner, Anita J; Hyder, Fahmeed; Piepmeier, Joseph M; Saltzman, W Mark; Zhou, Jiangbing

2015-02-01

Current therapy for glioblastoma multiforme (GBM) is largely ineffective, with nearly universal tumor recurrence. The failure of current therapy is primarily due to the lack of approaches for the efficient delivery of therapeutics to diffuse tumors in the brain. In our prior study, we developed brain-penetrating nanoparticles that are capable of penetrating brain tissue and distribute over clinically relevant volumes when administered via convection-enhanced delivery (CED). We demonstrated that these particles are capable of efficient delivery of chemotherapeutics to diffuse tumors in the brain, indicating that they may serve as a groundbreaking approach for the treatment of GBM. In the original study, nanoparticles in the brain were imaged using positron emission tomography (PET). However, clinical translation of this delivery platform can be enabled by engineering a non-invasive detection modality using magnetic resonance imaging (MRI). For this purpose, we developed chemistry to incorporate superparamagnetic iron oxide (SPIO) into the brain-penetrating nanoparticles. We demonstrated that SPIO-loaded nanoparticles, which retain the same morphology as nanoparticles without SPIO, have an excellent transverse (T(2)) relaxivity. After CED, the distribution of nanoparticles in the brain (i.e., in the vicinity of injection site) can be detected using MRI and the long-lasting signal attenuation of SPIO-loaded brain-penetrating nanoparticles lasted over a one-month timecourse. Development of these nanoparticles is significant as, in future clinical applications, co-administration of SPIO-loaded nanoparticles will allow for intraoperative monitoring of particle distribution in the brain to ensure drug-loaded nanoparticles reach tumors as well as for monitoring the therapeutic benefit with time and to evaluate tumor relapse patterns.

Analysis and measurements of low frequency lightning component penetration through aerospace vehicle metal and graphite skins

NASA Technical Reports Server (NTRS)

Robb, J. D.; Chen, T.

1980-01-01

An analysis of the shielding properties of mixed metal and graphite composite structures has illustrated some important aspects of electromagnetic field penetration into the interior. These include: (1) that graphite access doors on metallic structures will attenuate lightning magnetic fields very little; conversely, metal doors on a graphite structure will also attenuate fields from lightning strike currents very little, i.e., homogeneity of the shield is a critical factor in shielding and (2) that continuous conductors between two points inside a graphite skin such as an air data probe metallic tubing connection to an air data computer can allow large current penetrations into a vehicle interior. The true weight savings resulting from the use of composite materials can only be evaluated after the resulting electromagnetic problems such as current penetrations have been solved, and this generally requires weight addition in the form of cable shields, conductor bonding or external metallization.

Current oscillations in semi-insulating GaAs associated with field-enhanced capture of electrons by the major deep donor EL2

NASA Technical Reports Server (NTRS)

Kaminska, M.; Parsey, J. M.; Lagowski, J.; Gatos, H. C.

1982-01-01

Current oscillations thermally activated by the release of electrons from deep levels in undoped semiinsulating GaAs were observed for the first time. They were attributed to electric field-enhanced capture of electrons by the dominant deep donor EL2 (antisite AsGa defect). This enhanced capture is due to the configurational energy barrier of EL2, which is readily penetrated by hot electrons.

Hydrogel-forming Microneedle Arrays Exhibit Antimicrobial Properties: Potential for Enhanced Patient Safety

PubMed Central

Donnelly, Ryan F.; Singh, Thakur Raghu Raj; Alkilani, Ahlam Zaid; McCrudden, Maelíosa T.C.; O’Mahony, Conor; Armstrong, Keith; McLoone, Nabla; Kole, Prashant; Woolfson, A. David

2014-01-01

We describe, for the first time, the microbial characterisation of hydrogel-forming polymeric microneedle arrays and the potential for passage of microorganisms into skin following microneedle penetration. Uniquely, we also present insights into the storage stability of these hydroscopic formulations, from physical and microbiological viewpoints, and examine clinical performance and safety in human volunteers. Experiments employing excised porcine skin and radiolabelled microorganisms showed that microorganisms can penetrate skin beyond the stratum corneum following microneedle puncture. Indeed, the numbers of microorganisms crossing the stratum corneum following microneedle puncture was greater than 105 cfu in each case. However, no microorganisms crossed the epidermal skin. When using a 21G hypodermic needle, more than 104 microorganisms penetrated into the viable tissue and 106 cfu of C. albicans and S. epidermidis completely crossed the epidermal skin in 24 h. The hydrogel-forming materials contained no microorganisms following de-moulding and exhibited no microbial growth during storage, while also maintaining their mechanical strength, apart from when stored at relative humidities of 86%. No microbial penetration through the swelling microneedles was detectable, while human volunteer studies confirmed that skin or systemic infection is highly unlikely when polymeric microneedles are used for transdermal drug delivery. Since no pharmacopoeial standards currently exist for microneedle-based products, the exact requirements for a proprietary product based on hydrogel-forming microneedles are at present unclear. However, we are currently working towards a comprehensive specification set for this microneedle system that may inform future developments in this regard. PMID:23644043

Effect of tail plasma sheet conditions on the penetration of the convection electric field in the inner magnetosphere: RCM simulations with self-consistent magnetic field

NASA Astrophysics Data System (ADS)

Gkioulidou, M.; Wang, C.; Lyons, L. R.; Wolf, R.

2009-12-01

Transport of plasma sheet particles into the inner magnetosphere is strongly affected by the penetration of the convection electric field, which is the result of the large-scale magnetosphere ionosphere electromagnetic coupling. This transport, on the other hand, results in plasma heating and magnetic field stretching, which become very significant in the inner plasma sheet (inside 20 RE). We have previously run simulations with the Rice Convection Model (RCM), using the Tsyganenko 96 magnetic field model, to investigate how the earthward penetration of electric field depends on plasma sheet conditions. Outer proton and electron sources at r ~20 RE, are based on 11 years of Geotail data, and realistically represent the mixture of cold and hot plasma sheet population as a function of MLT and interplanetary conditions. We found that shielding of the inner magnetosphere electric field is more efficient for a colder and denser plasma sheet, which is found following northward IMF, than for the hotter and more tenuous plasma sheet found following southward IMF. Our simulation results so far indicate further earthward penetration of plasma sheet particles in response to enhanced convection if the preceding IMF is southward, which leads to weaker electric field shielding. Recently we have integrated the RCM with a magnetic field solver to obtain magnetic fields that are in force balance with given plasma pressures in the equatorial plane. We expect the self-consistent magnetic field to have a pronounced dawn dusk asymmetry due to the asymmetric inner magnetospheric pressure. This should affect the radial distance and MLT of plasma sheet penetration into the inner magnetosphere. We are currently using this force-balanced and self-consistent model with our realistic boundary conditions to evaluate the dependence of the shielding timescale on pre-existing plasma sheet number density and temperature and to more quantitatively determine the correlation between the plasma sheet conditions and spatial distribution of the penetrating particles. Our results are potentially crucial to understanding the contribution of plasma sheet penetration to the development of the storm-time ring current.

A clinical comparison of penetrating and blunt traumatic brain injuries.

PubMed

Santiago, Luis A; Oh, Bryan C; Dash, Pramod K; Holcomb, John B; Wade, Charles E

2012-01-01

Traumatic brain injury (TBI) is a leading cause of injury death and long-term disability in the USA. It commonly results from blunt (closed) or penetrating trauma. The majority of civilian TBI is caused by falls or motor vehicle collisions, whereas military TBI mainly results from explosions. Although penetrating injuries are less common than closed injuries in the civilian population, they are far more lethal. Unfortunately, the pathophysiologic differences between penetrating and closed TBI remain poorly understood due to the lack of studies on the subject. Many studies on the prognostic factors of mortality and functional outcome after TBI exclude penetrating brain injuries from their series because they are believed to have a different pathophysiology. 125 Articles regarding brain injury were reviewed and summarized for this report. Despite the absence of a clear delineation between penetrating and blunt TBI, the current guidelines for penetrating TBI suggest defaulting to management strategies used for closed TBI with limited supportive evidence. Thus, injuries that appear to have different pathophysiologies and outcomes are managed equally and perhaps not optimally. In view of the incomplete understanding of the impact of mechanism of injury on TBI outcomes, as demonstrated in the current review, new research studies are required to improve evidence-based TBI guidelines tailored especially for penetrating injuries.

Real-Time Penetrating Particle Analyzer (PAN)

NASA Astrophysics Data System (ADS)

Wu, X.; Ambrosi, G.; Bertucci, B.

2018-02-01

The PAN can measure penetrating particles with great precision to study energetic particles, solar activities, and the origin and propagation of cosmic rays. The real-time monitoring of penetrating particles is crucial for deep space human travel.

Characterization of scintillator crystals for usage as prompt gamma monitors in particle therapy

NASA Astrophysics Data System (ADS)

Roemer, K.; Pausch, G.; Bemmerer, D.; Berthel, M.; Dreyer, A.; Golnik, C.; Hueso-González, F.; Kormoll, T.; Petzoldt, J.; Rohling, H.; Thirolf, P.; Wagner, A.; Wagner, L.; Weinberger, D.; Fiedler, F.

2015-10-01

Particle therapy in oncology is advantageous compared to classical radiotherapy due to its well-defined penetration depth. In the so-called Bragg peak, the highest dose is deposited; the tissue behind the cancerous area is not exposed. Different factors influence the range of the particle and thus the target area, e.g. organ motion, mispositioning of the patient or anatomical changes. In order to avoid over-exposure of healthy tissue and under-dosage of cancerous regions, the penetration depth of the particle has to be monitored, preferably already during the ongoing therapy session. The verification of the ion range can be performed using prompt gamma emissions, which are produced by interactions between projectile and tissue, and originate from the same location and time of the nuclear reaction. The prompt gamma emission profile and the clinically relevant penetration depth are correlated. Various imaging concepts based on the detection of prompt gamma rays are currently discussed: collimated systems with counting detectors, Compton cameras with (at least) two detector planes, or the prompt gamma timing method, utilizing the particle time-of-flight within the body. For each concept, the detection system must meet special requirements regarding energy, time, and spatial resolution. Nonetheless, the prerequisites remain the same: the gamma energy region (2 to 10 MeV), high counting rates and the stability in strong background radiation fields. The aim of this work is the comparison of different scintillation crystals regarding energy and time resolution for optimized prompt gamma detection.

Nondestructive Testing Information Analysis Center, 1979.

DTIC Science & Technology

1980-09-01

transmission and reflectometry Ultrasonic imaging Spectrum analysis Acoustic emission * LIQUID PENETRANT TESTING Dye penetrants Fluorescent penetrants...OPTICAL TESTING Visual testing Optical reflectometry and transmission Holography * THERMAL TESTING Infrared radiometry The rmography 13 The present...on our surveillance effectiveness, we also scan Current Contents, NASA /SCAN, and the monthly Engineering Index and Science Abstracts. New books

The effect of welding parameters on penetration in GTA welds

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

Shirali, A.A.; Mills, K.C.

1993-07-01

The effect of various welding parameters on the penetration of GTA welds has been investigated. Increases in welding speed were found to reduce penetration; however, increases in welding current were observed to increase the penetration in high sulfur (HS) casts and decrease penetration in low sulfur (LS) steels. Plots of penetration as a function of increasing linear energy (the heat supplied per unit length of weld) revealed a similar trend with increased penetration in HS casts, but the penetration in LS casts was unaffected by increases in linear energy. These results support the Burgardt-Heiple proposition that changes in welding parametersmore » on penetration can be explained in terms of their effect, sequentially, on the temperature gradient and the Marangoni forces operating in the weld pool. Increases in arc length were found to decrease weld penetration regardless of the sulfur concentration of the steel, and the effects of electrode geometry and welding position on weld penetration were also investigated.« less

Prospects for Off-axis Current Drive via High Field Side Lower Hybrid Current Drive in DIII-D

NASA Astrophysics Data System (ADS)

Wukitch, S. J.; Shiraiwa, S.; Wallace, G. M.; Bonoli, P. T.; Holcomb, C.; Park, J. M.; Pinsker, R. I.

2017-10-01

An outstanding challenge for an economical, steady state tokamak is efficient off-axis current drive scalable to reactors. Previous studies have focused on high field side (HFS) launch of lower hybrid waves for current drive (LHCD) in double null configurations in reactor grade plasmas. The goal of this work is to find a HFS LHCD scenario for DIII-D that balances coupling, power penetration and damping. The higher magnetic field on the HFS improves wave accessibility, which allows for lower n||waves to be launched. These waves penetrate farther into the plasma core before damping at higher Te yielding a higher current drive efficiency. Utilizing advanced ray tracing and Fokker Planck simulation tools (GENRAY+CQL3D), wave penetration, absorption and drive current profiles in high performance DIII-D H-Mode plasmas were investigated. We found LH scenarios with single pass absorption, excellent wave penetration to r/a 0.6-0.8, FWHM r/a=0.2 and driven current up to 0.37 MA/MW coupled. These simulations indicate that HFS LHCD has potential to achieve efficient off-axis current drive in DIII-D and the latest results will be presented. Work supported by U.S. Dept. of Energy, Office of Science, Office of Fusion Energy Sciences, using User Facility DIII-D, under Award No. DE-FC02-04ER54698 and Contract No. DE-FC02-01ER54648 under Scientific Discovery through Advanced Computing Initiative.

Acoustic-Emission Weld-Penetration Monitor

NASA Technical Reports Server (NTRS)

Maram, J.; Collins, J.

1986-01-01

Weld penetration monitored by detection of high-frequency acoustic emissions produced by advancing weld pool as it melts and solidifies in workpiece. Acoustic emission from TIG butt weld measured with 300-kHz resonant transducer. Rise in emission level coincides with cessation of weld penetration due to sudden reduction in welding current. Such monitoring applied to control of automated and robotic welders.

Influence of anatomical site and topical formulation on skin penetration of sunscreens

PubMed Central

Benson, Heather AE; Sarveiya, Vikram; Risk, Stacey; Roberts, Michael S

2005-01-01

Sunscreen products are widely used to protect the skin from sun-related damage. Previous studies have shown that some sunscreen chemicals are absorbed across the skin to the systemic circulation. The current study shows that absorption into the skin of sunscreen chemicals applied to the face is up to four times greater than that of the same product applied to the back. This has implications for the way sunscreen products are formulated and may allow the use of less potent products on the face compared with the rest of the body. The effect of formulation vehicles on the release and skin penetration of the common sunscreen agent benzophenone-3 (common name oxybenzone) was also assessed. Penetration of benzophenone-3 across excised human epidermis and high-density polyethylene (HDPE) membrane was measured using in vitro Franz-type diffusion cells. Penetration and epidermal retention was measured following application of infinite and finite (epidermis only) doses of benzophenone-3 in five vehicles: liquid paraffin, coconut oil, 50:50 ethanol:coconut oil, aqueous cream BP, and oily cream BP. Highest benzophenone-3 skin retention was observed for the ethanol:coconut oil combination. Maximal and minimal benzophenone-3 fluxes were observed from liquid paraffin and coconut oil, respectively. The alcohol-based vehicle exhibited low benzophenone-3 release from the vehicle but high skin penetration and retention. PMID:18360561

31P Solid-state NMR based monitoring of permeation of cell penetrating peptides into skin

PubMed Central

Desai, Pinaki R.; Cormier, Ashley R.; Shah, Punit P.; Patlolla, Ram R.; Paravastu, Anant K.; Singh, Mandip

2013-01-01

The main objective of the current study was to investigate penetration of cell penetrating peptides (CPPs: TAT, R8, R11 and YKA) through skin intercellular lipids using 31P magic angle spinning (MAS) solid-state NMR. In vitro skin permeation studies were performed on rat skin, sections (0–60, 61–120 and 121–180 µm) were collected and analyzed for 31P NMR signal. The concentration dependent shift of 0, 25, 50, 100 and 200 mg/ml of TAT on skin layers, diffusion of TAT, R8, R11 and YKA in the skin and time dependent permeation of R11 was measured on various skin sections using 31P solid-state NMR. Further, CPPs and CPP-tagged fluorescent dye encapsulate liposomes (FLip) in skin layers were tagged using confocal microscopy. The change in 31P NMR chemical shift was found to depend monotonically on the amount of CPP applied on skin, with saturation behavior above 100 mg/ml CPP concentration. R11 and TAT caused more shift in solid-state NMR peaks compared to other peptides. Furthermore, NMR spectra showed R11 penetration up to 180 µm within 30 min. The results of the solid-state NMR study were in agreement with confocal microscopy studies. Thus, 31P solid-state NMR can be used to track CPP penetration into different skin layers. PMID:23702274

Bacterial and dye penetration through interim restorations used during endodontic treatment of molar teeth.

PubMed

Chailertvanitkul, Pattama; Abbott, Paul V; Riley, Thomas V; Sooksuntisakoonchai, Namchai

2009-07-01

The purpose of this study was to investigate the association between dye and bacterial penetration through interim restorations used during endodontic treatment. Sixty-four extracted human teeth were used, with 2 teeth each as positive and negative controls. Endodontic access with a mesio-occluso-distal cavity was prepared. Palatal cusps of maxillary molars and buccal cusps of mandibular molars were removed. Cotton was placed over the canals and covered with Cavit. Thirty teeth were restored with Ketac Silver (KS) and 30 with KS reinforced with a stainless steel band (KSSB). Samples were submersed in India ink mixed with brain heart infusion broth containing Streptococcus gordonii. After 3 months of simulated chewing, structural integrity and dye and bacterial penetration were assessed. Positive controls had both dye and bacterial penetration. Negative controls had no dye or bacterial penetration. All KS restorations debonded, whereas 18 KSSB restorations (60%) debonded. KS restorations were 1.67 times more likely to debond than KSSB restorations (Fisher exact test). KS was 1.3 times more likely to have dye penetration than KSSB (Fisher exact test) and 3 times more likely to have bacterial penetration, although not statistically significant (chi(2) test). Overall, 88.3% of specimens had dye penetration, and 20% had bacterial penetration. This 68.3% difference indicated no association between dye and bacterial penetration (exact McNemar test). Stainless steel bands helped maintain structural integrity of KS restorations under masticatory function. Bands helped prevent dye penetration but not bacterial penetration. There was no association between dye and bacterial penetration.

A new penetration test method: protection efficiency of glove and clothing materials against diphenylmethane diisocyanate (MDI).

PubMed

Henriks-Eckerman, Maj-Len; Mäkelä, Erja

2015-03-01

Reported cases of allergic contact dermatitis caused by methylenediphenyl diisocyanate (MDI) have increased and thereby increased the need for adequate skin protection. Current standardized permeation and penetration test methods give information about efficacy of protective materials against individual components of the polyurethane systems. They do not give information of what kind of clothing materials workers should wear against splashes when handling mixed MDI-polyurethane formulations, which contain MDI, its oligomers, and polyols. The aim of this study was to develop and validate a sensitive penetration test method that can be used to select clothing that is protective enough against uncured splashes of MDI-polyurethane, still easy to use, and also, to find affordable glove materials that provide adequate protection during a short contact. The penetration of MDI through eight representative glove or clothing materials was studied with the developed test procedure. One MDI hardener and two polymeric MDI (PMDI)-polyol formulations representing different curing times were used as test substances. The materials tested included work clothing (woven) fabric, arm shields (nonwoven fabric), old T-shirt, winter gloves, and gloves of nitrile rubber, leather, vinyl (PVC), and natural rubber. A drop (50 µl) of test substance was added to the outer surface of the glove/clothing material, which had Tape Fixomull attached to the inner surface as a collection medium. After penetration times of 5 or 20min, the collecting material was removed and immediately immersed into acetonitrile containing 1-(2-methoxyphenyl)-piperazine for derivatization. The formed urea derivatives of 2,4'-MDI and 4,4'-MDI were analysed using liquid chromatography with mass spectrometric and UV detection. The precision of the test method was good for the material with high penetration (work clothing fabric) of MDI, as the relative standard deviation (RSD) was 14 and 20%. For the arm shield with a low penetration (the nonwoven fabric), the precision was lower with RSDs of 35 and 50%. For two clothing materials, the penetration was high (134-577 µg cm(-2)). Low penetration (<0.5 µg cm(-2)) was shown by the arm shield and the natural rubber glove. Three glove materials showed no detectable MDI penetration (<0.002 µg cm(-2)). Two affordable glove materials (natural rubber and nitrile rubber) and one clothing material (dust proof arm shield) that can provide adequate protection during short contact with solvent free PMDI formulations were found. The new test procedure should be standardized in order to get a new international penetration standard. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Current drive at plasma densities required for thermonuclear reactors.

PubMed

Cesario, R; Amicucci, L; Cardinali, A; Castaldo, C; Marinucci, M; Panaccione, L; Santini, F; Tudisco, O; Apicella, M L; Calabrò, G; Cianfarani, C; Frigione, D; Galli, A; Mazzitelli, G; Mazzotta, C; Pericoli, V; Schettini, G; Tuccillo, A A

2010-08-10

Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors.

Cost Assessment for Shielding of C3 Type. Facilities

DTIC Science & Technology

1980-03-01

imperfections and on penetrations . Long-conductor penetrants are assumed to enter the building through a one-quarter-inch thick entry plate and a shielded...Effects 21 3.2.3 Currents from Penetrants 21 3.2.4 Numerical Examples 23 3.3 Design Approach 23 3.3.1 Design Assuming Linear Behavior of Shield 23...General 36 4.1.1 Envelope Shield 36 4.1.2 Penetrations 41 4.2 Condition I, New Construction, External Shield 46 4.3 Condition II, New

Comparative analysis of the effects of CO2 fractional laser and sonophoresis on human skin penetration with 5-aminolevulinic acid.

PubMed

Choi, J H; Shin, E J; Jeong, K H; Shin, M K

2017-11-01

Successful delivery of a photosensitizer into the skin is an important factor for effective photodynamic therapy (PDT). The effective method to increase drug penetration within short incubation time overcoming skin barrier have been investigated. This study was performed to analyze and compare the effectiveness of ablative fractional laser (FXL) pretreatment and/or sonophoresis for enhancing the penetration of 5-aminolevulinic acid (ALA) into human skin in vivo. Twenty-four identical 1 × 1 cm 2 treatment areas were mapped on the backs of ten healthy male subjects. Each area received FXL pretreatment and/or sonophoresis with different energy settings and ALA incubation times. After treatments, porphyrin fluorescence reflecting the ALA penetration were measured. Application of ablative CO 2 FXL pretreatment resulted to higher fluorescence intensities than the non-treatment group. Incubation times were positively correlated with the increments of ALA penetration. However, increasing pulse energy or combining with sonophoresis did not show additional positive effects on ALA penetration. Ablative CO 2 FXL pretreatment effectively facilitated ALA penetration in human skin in vivo. Ablative CO 2 FXL alone without sonophoresis setting pulse energy of 10 and 20 mJ with more than 60 min of ALA incubation time could be an ideal setting for ALA penetration.

Studies on the Parametric Effects of Plasma Arc Welding of 2205 Duplex Stainless Steel

NASA Astrophysics Data System (ADS)

Selva Bharathi, R.; Siva Shanmugam, N.; Murali Kannan, R.; Arungalai Vendan, S.

2018-03-01

This research study attempts to create an optimized parametric window by employing Taguchi algorithm for Plasma Arc Welding (PAW) of 2 mm thick 2205 duplex stainless steel. The parameters considered for experimentation and optimization are the welding current, welding speed and pilot arc length respectively. The experimentation involves the parameters variation and subsequently recording the depth of penetration and bead width. Welding current of 60-70 A, welding speed of 250-300 mm/min and pilot arc length of 1-2 mm are the range between which the parameters are varied. Design of experiments is used for the experimental trials. Back propagation neural network, Genetic algorithm and Taguchi techniques are used for predicting the bead width, depth of penetration and validated with experimentally achieved results which were in good agreement. Additionally, micro-structural characterizations are carried out to examine the weld quality. The extrapolation of these optimized parametric values yield enhanced weld strength with cost and time reduction.

Enabling kinetic micro-penetrator technology for Solar System research

NASA Astrophysics Data System (ADS)

Gowen, R. A.

2008-09-01

Whilst the concept of high speed impacting penetrator probes is not new, recent highly successful ground test results have considerably improved the perception that these can be a viable and useful addition to the current toolbox of planetary probes. Previous developments only led to a single deployment (Deep Space-2 to Mars on the ill fated NASA Mars Polar Lander mission in 1999) where neither the soft lander nor penetrator was ever heard from, which is not a logical basis for dismissing penetrator technology. Other space penetrator programmes have included the Russian Mars'96 ~80m/s penetrators for which the whole mission was lost before the spacecraft left Earth orbit, and the Japanese Lunar-A program which was cancelled after a lengthy development program which however saw multiple successful ground trials. The Japanese penetrators were designed for ~300m/s impact. The current UK penetrator developments are actively working towards full space qualification for a Lunar penetrators (MoonLITE mission), which would also provide a significant technical demonstration towards the development of smaller, shorter lived penetrators for exploring other solar system objects. We are advocating delivered micro-penetrators in the mass range ~4-10Kg, (preceded by ~13Kg Lunar penetrator MoonLITE development program), impacting at around 100-500m/s and carrying a scientific payload of around 2Kg. Additional mass is required to deliver the probes from `orbit' to surface which is dependent upon the particular planetary body in question. The mass per descent module therefore involves and additional element which, for a descent through an atmosphere could be quite modest, while for a flyby deployment, can be substantial. For Europa we estimate a descent module mass of ~13 Kg, while for Enceladus the value is ~40Kg for Enceladus since a deceleration of ~3.8 kms-1 is needed from a Titan orbit. The delivery system could consist of a rocket deceleration motor and attitude control system, to e.g. simple fins for bodies with atmospheres Whilst a 2Kg payload may be considered to be very low mass we propose that it is sufficient to carry out a comprehensive range of scientific investigations of the highest priority, and can include a chemistry package (e.g. mass spectrometer with drill, doped optical fibres), micro-seismometers and accelerometers, together with a package of environment sensors capable of measuring temperature, heat flow, dielectric constant, radiation levels, magnetic fields, and a descent camera. Other very low mass options also include a subsurface mineralogy/astrobiology camera; simple redox and pH instruments; and a beeping transmitter to allow radio interferometery from Earth to detect surface motions whether seismic or tidally induced. At present most of these payload instruments either have good space heritage but no impact qualification; are very simple; or have been fully space qualified with the previous space hardware developments. The UK penetrator consortium is currently actively pursuing a program to provide full space qualification for most of the above instruments, of which sensor elements of the mass spectrometer, prototype drill component, micro-seismometers, magnetometer, radiation sensors have currently survived the recent (May 2008) impact test at 310ms-1with a worst case 8- 10 degrees attack angle (offset between velocity vector and normal incidence angle) where forces in excess of 10Kgee were experienced. Such a payload is capable of significant sub-surface chemical inventory identification including refactory, organic materials; seismic investigations of the interior of active bodies; sub-surface mechanical information including layering from accelerometers and mineralogy/astrobiology camera, and ground truth from orbiting experiments such as dielectric constant which is particularly relevant to orbiting ground penetrating radar measurements. A descent camera can provide both impact site geophysical context as well as public media images. These penetrators are ideal for vangard investigations of planetary bodies, or exploration of multiple sites where low mass is of particular benefit. They can provide a substantial scientific standalone capability; ground truth to orbiting instrument; provide concurrent missions with key data at other geographical locations; and provide broad scientific information to guide follow-on missions to more highly focused science investigations with more capable soft landed scientific instruments. Solar system bodies which are applicable to penetrator investigations are numerous and include the Moon, and the current ESA Cosmic Vision proposed missions to Europa, Titan and Enceladus. Other bodies would also include Near Earth Objects (NEOs) for which accelerometers in particular could be EPSC Abstracts, Vol. 3, EPSC2008-A-00526, 2008 European Planetary Science Congress, Author(s) 2008 instrumental in determining whether such objects are solid rock or loose rubble piles as currently thought. Though Mars already has a fairly mature and heavy investigative program both current and planned, the ability to implant a planet wide seismic network would be advantageous as well as extending astrobiologic investigations to new sites. The MoonLITE mission is a proposed UK led lunar mission which is planned to complete a phase-A study in the spring of 2009 with a possible launch in 2013. MoonLITE would comprise of 4 13 kg penetrators distributed widely upon the Moon including shaded polar craters and the far side. An orbiter would relay signals between penetrator and Earth. Key additional steps to enable exploration of other solar system bodies includes impact into harder (icy) and rough surfaces; increased radiation environments; and communications where a trailing aerial to mitigate signal attenuation through more heavily attenuating materials may be more prevalent. Also, significant is the desire to reduce the probe mass, which is envisaged to arise from a reduced lifetime of hours to weeks compared with ~1 year on the Moon, and by adopting new materials and technologies. Delivery of the probes is also likely to differ for each world, whether airless or with atmosphere, and the technology to deliver smaller probes, and with widely varying delta-V requirements requiring shorter and longer flight times. Surprisingly, operation in very cold environments is shared with the Moon's permanently shadowed craters.

The parametric modified limited penetrable visibility graph for constructing complex networks from time series

NASA Astrophysics Data System (ADS)

Li, Xiuming; Sun, Mei; Gao, Cuixia; Han, Dun; Wang, Minggang

2018-02-01

This paper presents the parametric modified limited penetrable visibility graph (PMLPVG) algorithm for constructing complex networks from time series. We modify the penetrable visibility criterion of limited penetrable visibility graph (LPVG) in order to improve the rationality of the original penetrable visibility and preserve the dynamic characteristics of the time series. The addition of view angle provides a new approach to characterize the dynamic structure of the time series that is invisible in the previous algorithm. The reliability of the PMLPVG algorithm is verified by applying it to three types of artificial data as well as the actual data of natural gas prices in different regions. The empirical results indicate that PMLPVG algorithm can distinguish the different time series from each other. Meanwhile, the analysis results of natural gas prices data using PMLPVG are consistent with the detrended fluctuation analysis (DFA). The results imply that the PMLPVG algorithm may be a reasonable and significant tool for identifying various time series in different fields.

Caval penetration by retrievable inferior vena cava filters: a retrospective comparison of Option and Günther Tulip filters.

PubMed

Olorunsola, Olufoladare G; Kohi, Maureen P; Fidelman, Nicholas; Westphalen, Antonio C; Kolli, Pallav K; Taylor, Andrew G; Gordon, Roy L; LaBerge, Jeanne M; Kerlan, Robert K

2013-04-01

To compare the frequency of vena caval penetration by the struts of the Option and Günther Tulip cone filters on postplacement computed tomography (CT) imaging. All patients who had an Option or Günther Tulip inferior vena cava (IVC) filter placed between January 2010 and May 2012 were identified retrospectively from medical records. Of the 208 IVC filters placed, the positions of 58 devices (21 Option filters, 37 Günther Tulip filters [GTFs]) were documented on follow-up CT examinations obtained for reasons unrelated to filter placement. In cases when multiple CT studies were obtained after placement, each study was reviewed, for a total of 80 examinations. Images were assessed for evidence of caval wall penetration by filter components, noting the number of penetrating struts and any effect on pericaval tissues. Penetration of at least one strut was observed in 17% of all filters imaged by CT between 1 and 447 days following placement. Although there was no significant difference in the overall prevalence of penetration when comparing the Option filter and GTF (Option, 10%; GTF, 22%), only GTFs showed time-dependent penetration, with penetration becoming more likely after prolonged indwelling times. No patient had damage to pericaval tissues or documented symptoms attributed to penetration. Although the Günther Tulip and Option filters exhibit caval penetration at CT imaging, only the GTF exhibits progressive penetration over time. Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.

Characterization and Consolidation of Tungsten Nanopowders Produced by Salt-Assisted Combustion Synthesis

DTIC Science & Technology

2010-09-01

all other elements were measured by direct current plasma emission spectroscopy. Powder nos. 1, 2, and 3 were initially sent out for measurement of...shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number...penetrators. DU is currently used due to its high density, as well as its tendency to form adiabatic shear bands as the penetrator enters a target

Edge Ohmic Heating Experiment on HT-6M Tokamak

NASA Astrophysics Data System (ADS)

Gao, Xiang; Fan, Shuping; Li, Jian'gang; Meng, Yuedong; Luo, Jiarong; Yin, Fuxian; Zeng, Lei; Ding, Liancheng; Lin, Bili; Zhang, Wei; Han, Yuqing; Tong, Xingde; Luo, Lanchang; Gong, Xianzu; Jiang, Jiaguang; Wu, Mingjun; Yin, Fei

1994-03-01

An improved ohmic confinement has been achieved on HT-6M tokamak after application of edge ohmic heating pulse which makes plasma current rapidly ramp up (0.4 ms) in a ramp rate of 12 Ma/s. The improved ohmic confinement phase is characterized by (a) energy and particle confinement time increase, (b) non-symmetric increased density ne, (c) reduced Hα radiation, (d) increased Te and steeper Te, ne profile at the edge. The results from soft x-ray sawteeth inversion radius and βp + li/2 implied the anomalous current penetration.

Announcment: Conference on Obscured AGN Across Cosmic Time

NASA Astrophysics Data System (ADS)

2006-12-01

Current deep surveys, notably in X-rays and the mid-IR, are making it possible to carry out a census of essentially all the luminous AGN in the Universe. By pene-trating the obscuration that, in Type 2 sources, hides the nuclear regions in the UV to the near-IR spectrum, these new surveys are finding the radio quiet coun-terparts of the powerful radio galaxies.

Particle loading time and humidity effects on the efficiency of an N95 filtering facepiece respirator model under constant and inhalation cyclic flows.

PubMed

Mahdavi, Alireza; Haghighat, Fariborz; Bahloul, Ali; Brochot, Clothilde; Ostiguy, Claude

2015-06-01

It is necessary to investigate the efficiencies of filtering facepiece respirators (FFRs) exposed to ultrafine particles (UFPs) for long periods of time, since the particle loading time may potentially affect the efficiency of FFRs. This article aims to investigate the filtration efficiency for a model of electrostatic N95 FFRs with constant and 'inhalation-only' cyclic flows, in terms of particle loading time effect, using different humidity conditions. Filters were exposed to generated polydisperse NaCl particles. Experiments were performed mimicking an 'inhalation-only' scenario with a cyclic flow of 85 l min(-1) as the minute volume [or 170 l min(-1) as mean inhalation flow (MIF)] and for two constant flows of 85 and 170 l min(-1), under three relative humidity (RH) levels of 10, 50, and 80%. Each test was performed for loading time periods of 6h and the particle penetration (10-205.4nm in electrical mobility diameter) was measured once every 2h. For a 10% RH, the penetration of smaller size particles (<80nm), including the most penetrating particle size (MPPS), decreased over time for both constant and cyclic flows. For 50 and 80% RH levels, the changes in penetration were typically observed in an opposite direction with less magnitude. The penetrations at MPPS increased with respect to loading time under constant flow conditions (85 and 170 l min(-1)): it did not substantially increase under cyclic flows. The comparison of the cyclic flow (85 l min(-1) as minute volume) and constant flow equal to the cyclic flow minute volume indicated that, for all conditions the penetration was significantly less for the constant flow than that of cyclic flow. The comparison between the cyclic (170 l min(-1) as MIF) and constant flow equal to cyclic flow MIF indicated that, for the initial stage of loading, the penetrations were almost equal, but they were different for the final stages of the loading time. For a 10% RH, the penetration of a wide range of sizes was observed to be higher with the cyclic flow (170 as MIF) than with the equivalent constant flow (170 l min(-1)). For 50 and 80% RH levels, the penetrations were usually greater with a constant flow (170 l min(-1)) than with a cyclic flow (170 l min(-1) as MIF). It is concluded that, for the tested electrostatic N95 filters, the change in penetration as a function of the loading time does not necessarily take place with the same rate under constant (MIF) and cyclic flow. Moreover, for all tested flow rates, the penetration is not only affected by the loading time but also by the RH level. Lower RH levels (10%) have decreasing penetration rates in terms of loading time, while higher RH levels (50 and 80%) have increasing penetration rates. Also, the loading of the filter is normally accompanied with a shift of MPPS towards larger sizes. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

High-Resolution Methods for Diagnosing Cartilage Damage In Vivo

PubMed Central

Novakofski, Kira D.; Pownder, Sarah L.; Koff, Matthew F.; Williams, Rebecca M.; Potter, Hollis G.; Fortier, Lisa A.

2016-01-01

Advances in current clinical modalities, including magnetic resonance imaging and computed tomography, allow for earlier diagnoses of cartilage damage that could mitigate progression to osteoarthritis. However, current imaging modalities do not detect submicrometer damage. Developments in in vivo or arthroscopic techniques, including optical coherence tomography, ultrasonography, bioelectricity including streaming potential measurement, noninvasive electroarthrography, and multiphoton microscopy can detect damage at an earlier time point, but they are limited by a lack of penetration and the ability to assess an entire joint. This article reviews current advancements in clinical and developing modalities that can aid in the early diagnosis of cartilage injury and facilitate studies of interventional therapeutics. PMID:26958316

Ground penetrating radar (GPR) analysis : Phase I.

DOT National Transportation Integrated Search

2009-11-01

"The objective of this work is to evaluate the feasibility of expanding the MDT's Ground Penetrating : Radar (GPR) program to a broader range of pavement evaluation activities. Currently, MDT uses GPR in : conjunction with its Falling Weight Deflecto...

Study of Proton cutoffs during geomagnetically disturbed times

NASA Astrophysics Data System (ADS)

Kanekal, S. G.; Looper, M. D.; Baker, D. N.; Blake, J. B.

Solar energetic particles SEP are currently classified into impulsive and gradual events The former are understood be accelerated at solar flares and the latter at interplanetary shocks driven by coronal mass ejections CMEs It is well known that CMEs also cause intense geomagnetic storms during which the geomagnetic field can be highly distorted During these times SEP fluxes penetrate the terrestrial magnetosphere and reach regions which may not be normally accessible to them The SEP access is of course controlled by the geomagnetic field configuration The cutoff latitude is a well defined latitude below which a charged particle of a given rigidity momentum per unit charge arriving from a given direction cannot penetrate SEPs constitute a radiation hazard to spacecraft and humans and measurement and prediction of the cutoff location are an important aspect of space weather This paper reports on the measurements of solar energetic proton cutoffs made by two satellites SAMPEX and Polar during geomagnetically disturbed times We study select SEP events occuring during the period 1996 to 2005 when both SAMPEX and Polar provide high quality data We will compare our measurements with cutoffs calculated by a charged particle tracing code which utilizes several currently used models of the geomagnetic field The measured SEP proton cutoffs cover a range of rigidities and are obtained at high-altitudes by the HIST detector onboard Polar and at low-altitudes by the PET and HILT detctors onboard SAMPEX

X-ray Imaging of Transplanar Liquid Transport Mechanisms in Single Layer Textiles.

PubMed

Zhang, Gannian; Parwani, Rachna; Stone, Corinne A; Barber, Asa H; Botto, Lorenzo

2017-10-31

Understanding the penetration of liquids within textile fibers is critical for the development of next-generation smart textiles. Despite substantial research on liquid penetration in the plane of the textile, little is known about how the liquid penetrates in the thickness direction. Here we report a time-resolved high-resolution X-ray measurement of the motion of the liquid-air interface within a single layer textile, as the liquid is transported across the textile thickness following the deposition of a droplet. The measurement of the time-dependent position of the liquid meniscus is made possible by the use of ultrahigh viscosity liquids (dynamic viscosity from 10 5 to 2.5 × 10 6  times larger than water). This approach enables imaging due to the slow penetration kinetics. Imaging results suggest a three-stage penetration process with each stage being associated with one of the three types of capillary channels existing in the textile geometry, providing insights into the effect of the textile structure on the path of the three-dimensional liquid meniscus. One dimensional kinetics studies show that our data for the transplanar penetration depth Δx L vs time do not conform to a power law, and that the measured rate of penetration for long times is smaller than that predicted by Lucas-Washburn kinetics, challenging commonly held assumptions regarding the validity of power laws when applied to relatively thin textiles.

Electron paramagnetic resonance field-modulation eddy-current analysis of silver-plated graphite resonators

NASA Astrophysics Data System (ADS)

Mett, Richard R.; Anderson, James R.; Sidabras, Jason W.; Hyde, James S.

2005-09-01

Magnetic field modulation is often introduced into a cylindrical TE011 electron paramagnetic resonance (EPR) cavity through silver plating over a nonconductive substrate. The plating thickness must be many times the skin depth of the rf and smaller than the skin depth of the modulation. We derive a parameter that quantifies the modulation field penetration and find that it also depends on resonator dimensions. Design criteria based on this parameter are presented graphically. This parameter is then used to predict the behavior of eddy currents in substrates of moderate conductivity, such as graphite. The conductivity of the graphite permits improved plating uniformity and permits use of electric discharge machining (EDM) techniques to make the resonator. EDM offers precision tolerances of 0.005 mm and is suitable for small, complicated shapes that are difficult to machine by other methods. Analytic predictions of the modulation penetration are compared with the results of finite-element simulations. Simulated magnetic field modulation uniformity and penetration are shown for several elemental coils and structures including the plated graphite TE011 cavity. Fabrication and experimental testing of the structure are discussed. Spatial inhomogeneity of the modulation phase is also investigated by computer simulation. We find that the modulation phase is uniform to within 1% over the TE011 cavity. Structures of lower symmetry have increased phase nonuniformity.

Measured responses of internal enclosures and cables due to burnthrough penetration of weapon cases by lightning

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

Schnetzer, G.H.; Fisher, R.J.; Dinallo, M.A.

1994-08-01

The electrical effects of lightning penetration of the outer case of a weapon on internal structures, such as a firing set housing, and on samples of a flat, flexline detonator cable have been investigated experimentally. Maximum open-circuit voltages measured on either simulated structures (126 V) or the cable (46 V) located directly behind the point of penetration were well below any level that is foreseen to create a threat to nuclear safety. On the other hand, it was found that once full burnthrough of the barrier occurred, significant fractions of the incident continuing currents coupled to both the simulated internalmore » structure (up to 300 A) or to the cable sample (69 A) when each was electrically connected internally to case ground. No occurrence was observed of the injection of large amplitude currents from return strokes occurring after barrier penetration. Under circumstances in which small volumes of trapped gases exist behind penetration sites, rapid heating of the gas by return strokes occurring after burnthrough has been shown to produced large mechanical impulses to the adjacent surfaces.« less

Electrodeless plasma acceleration system using rotating magnetic field method

NASA Astrophysics Data System (ADS)

Furukawa, T.; Takizawa, K.; Kuwahara, D.; Shinohara, S.

2017-11-01

We have proposed Rotating Magnetic Field (RMF) acceleration method as one of electrodeless plasma accelerations. In our experimental scheme, plasma generated by an rf (radio frequency) antenna, is accelerated by RMF antennas, which consist of two-pair, opposed, facing coils, and these antennas are outside of a discharge tube. Therefore, there is no wear of electrodes, degrading the propulsion performance. Here, we will introduce our RMF acceleration system developed, including the experimental device, e.g., external antennas, a tapered quartz tube, a vacuum chamber, external magnets, and a pumping system. In addition, we can change RMF operation parameters (RMF applied current IRMF and RMF current phase difference ϕ, focusing on RMF current frequency fRMF) by adjusting matching conditions of RMF, and investigate the dependencies on plasma parameters (electron density ne and ion velocity vi); e.g., higher increases of ne and vi (˜360 % and 55 %, respectively) than previous experimental results were obtained by decreasing fRMF from 5 MHz to 0.7 MHz, whose RMF penetration condition was better according to Milroy's expression. Moreover, time-varying component of RMF has been measured directly to survey the penetration condition experimentally.

Prediction of Weld Penetration in FCAW of HSLA steel using Artificial Neural Networks

NASA Astrophysics Data System (ADS)

Asl, Y. Dadgar; Mostafa, N. B.; Panahizadeh R., V.; Seyedkashi, S. M. H.

2011-01-01

Flux-cored arc welding (FCAW) is a semiautomatic or automatic arc welding process that requires a continuously-fed consumable tubular electrode containing a flux. The main FCAW process parameters affecting the depth of penetration are welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed. Shallow depth of penetration may contribute to failure of a welded structure since penetration determines the stress-carrying capacity of a welded joint. To avoid such occurrences; the welding process parameters influencing the weld penetration must be properly selected to obtain an acceptable weld penetration and hence a high quality joint. Artificial neural networks (ANN), also called neural networks (NN), are computational models used to express complex non-linear relationships between input and output data. In this paper, artificial neural network (ANN) method is used to predict the effects of welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed on weld penetration depth in gas shielded FCAW of a grade of high strength low alloy steel. 32 experimental runs were carried out using the bead-on-plate welding technique. Weld penetrations were measured and on the basis of these 32 sets of experimental data, a feed-forward back-propagation neural network was created. 28 sets of the experiments were used as the training data and the remaining 4 sets were used for the testing phase of the network. The ANN has one hidden layer with eight neurons and is trained after 840 iterations. The comparison between the experimental results and ANN results showed that the trained network could predict the effects of the FCAW process parameters on weld penetration adequately.

Characterization of Direct Current-Electrical Penetration Graph Waveforms and Correlation With the Probing Behavior of Matsumuratettix hiroglyphicus (Hemiptera: Cicadellidae), the Insect Vector of Sugarcane White Leaf Phytoplasma.

PubMed

Roddee, J; Kobori, Y; Yorozuya, H; Hanboonsong, Y

2017-06-01

The leafhopper Matsumuratettix hiroglyphicus (Matsumura) (Hemiptera: Cicadellidae) is an important vector of phytoplasma causing white leaf disease in sugarcane. Thus, the aim of our study was to understand and describe the stylet-probing activities of this vector while feeding on sugarcane plants, by using direct current (DC) electrical penetration graph (EPG) monitoring. The EPG signals were classified into six distinct waveforms, according to amplitude, frequency, voltage level, and electrical origin of the observed traces during stylet penetration into the host plant tissues (probing). These six EPG waveforms of probing behavior comprise no stylet penetration (NP); stylet pathway through epidermis, mesophyll, and parenchymal cells (waveform A); contact at the bundle sheath layer (waveform B); salivation into phloem sieve elements (waveform C); phloem sap ingestion (waveform D); and short ingestion time of xylem sap (waveform E). The above waveform patterns were correlated with histological data of salivary sheath termini in plant tissue generated from insect stylet tips. The key findings of this study were that M. hiroglyphicus ingests the phloem sap at a relatively higher rate and for longer duration from any other cell type, suggesting that M. hiroglyphicus is mainly a phloem-feeder. Quantitative comparison of probing behavior revealed that females typically probe more frequently and longer in the phloem than males. Thus, females may acquire and inoculate greater amounts of phytoplasma than males, enhancing the efficiency of phytoplasma transmission and potentially exacerbating disease spreading. Overall, our study provides basic information on the probing behavior and transmission mechanism of M. hiroglyphicus. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SWEAT: Snow Water Equivalent with AlTimetry

NASA Astrophysics Data System (ADS)

Agten, Dries; Benninga, Harm-Jan; Diaz Schümmer, Carlos; Donnerer, Julia; Fischer, Georg; Henriksen, Marie; Hippert Ferrer, Alexandre; Jamali, Maryam; Marinaci, Stefano; Mould, Toby JD; Phelan, Liam; Rosker, Stephanie; Schrenker, Caroline; Schulze, Kerstin; Emanuel Telo Bordalo Monteiro, Jorge

2017-04-01

To study how the water cycle changes over time, satellite and airborne remote sensing missions are typically employed. Over the last 40 years of satellite missions, the measurement of true water inventories stored in sea and land ice within the cryosphere have been significantly hindered by uncertainties introduced by snow cover. Being able to determine the thickness of this snow cover would act to reduce such error, improving current estimations of hydrological and climate models, Earth's energy balance (albedo) calculations and flood predictions. Therefore, the target of the SWEAT (Snow Water Equivalent with AlTimetry) mission is to directly measure the surface Snow Water Equivalent (SWE) on sea and land ice within the polar regions above 60°and below -60° latitude. There are no other satellite missions currently capable of directly measuring SWE. In order to achieve this, the proposed mission will implement a novel combination of Ka- and Ku-band radioaltimeters (active microwave sensors), capable of penetrating into the snow microstructure. The Ka-band altimeter (λ ≈ 0.8 cm) provides a low maximum snow pack penetration depth of up to 20 cm for dry snow at 37 GHz, since the volume scattering of snow dominates over the scattering caused by the underlying ice surface. In contrast, the Ku-band altimeter (λ ≈ 2 cm) provides a high maximum snowpack penetration depth of up to 15 m in high latitudes regions with dry snow, as volume scattering is decreased by a factor of 55. The combined difference in Ka- and Ku-band signal penetration results will provide more accurate and direct determination of SWE. Therefore, the SWEAT mission aims to improve estimations of global SWE interpreted from passive microwave products, and improve the reliability of numerical snow and climate models.

Topological properties of the limited penetrable horizontal visibility graph family

NASA Astrophysics Data System (ADS)

Wang, Minggang; Vilela, André L. M.; Du, Ruijin; Zhao, Longfeng; Dong, Gaogao; Tian, Lixin; Stanley, H. Eugene

2018-05-01

The limited penetrable horizontal visibility graph algorithm was recently introduced to map time series in complex networks. In this work, we extend this algorithm to create a directed-limited penetrable horizontal visibility graph and an image-limited penetrable horizontal visibility graph. We define two algorithms and provide theoretical results on the topological properties of these graphs associated with different types of real-value series. We perform several numerical simulations to check the accuracy of our theoretical results. Finally, we present an application of the directed-limited penetrable horizontal visibility graph to measure real-value time series irreversibility and an application of the image-limited penetrable horizontal visibility graph that discriminates noise from chaos. We also propose a method to measure the systematic risk using the image-limited penetrable horizontal visibility graph, and the empirical results show the effectiveness of our proposed algorithms.

Effects of HMO market penetration on physicians' work effort and satisfaction.

PubMed

Hadley, J; Mitchell, J M

1997-01-01

We investigate whether geographic variations in health maintenance organization (HMO) market penetration are associated with three aspects of physicians' practices: number of hours worked per year, number of patients seen per week, and satisfaction with the current practice. Based on multivariate regression analysis of data for 4,373 patient care physicians (under age forty-five) from a national random sample surveyed in 1991, we estimate that a doubling of the average level of HMO penetration is associated with statistically significant differences of 4 percent fewer annual hours, 13.7 percent fewer patients seen per week, and a 20 percent greater likelihood of not being very satisfied with one's current practice.

Tissue Penetration of Antifungal Agents

PubMed Central

Felton, Timothy; Troke, Peter F.

2014-01-01

SUMMARY Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection. PMID:24396137

Penetration depth of MgB2 measured using Josephson junctions and SQUIDs

NASA Astrophysics Data System (ADS)

Cunnane, Daniel; Zhuang, Chenggang; Chen, Ke; Xi, X. X.; Yong, Jie; Lemberger, T. R.

2013-02-01

The penetration depth of MgB2 was measured using two methods of different mechanisms. The first method used MgB2 Josephson junctions and the magnetic field dependence of the junction critical current. The second method deduced the penetration depth from the inductance of a MgB2 microstrip used to modulate the voltage of a MgB2 DC SQUID. The two methods showed a consistent value of the low-temperature penetration depth for MgB2 to be about 40 nm. Both the small penetration depth value and its temperature dependence are in agreement with a microscopic theory for MgB2 in the clean limit.

Van Allen Probes Measurements of Energetic Particle Deep Penetration Into the Low L Region (L < 4) During the Storm on 8 April 2016

NASA Astrophysics Data System (ADS)

Zhao, H.; Baker, D. N.; Califf, S.; Li, X.; Jaynes, A. N.; Leonard, T.; Kanekal, S. G.; Blake, J. B.; Fennell, J. F.; Claudepierre, S. G.; Turner, D. L.; Reeves, G. D.; Spence, H. E.

2017-12-01

Using measurements from the Van Allen Probes, a penetration event of tens to hundreds of keV electrons and tens of keV protons into the low L shells (L < 4) is studied. Timing and magnetic local time (MLT) differences of energetic particle deep penetration are unveiled and underlying physical processes are examined. During this event, both proton and electron penetrations are MLT asymmetric. The observed MLT difference of proton penetration is consistent with convection of plasma sheet protons, suggesting enhanced convection during geomagnetic active times to be the cause of energetic proton deep penetration during this event. The observed MLT difference of tens to hundreds of keV electron penetration is completely different from tens of keV protons and cannot be well explained by inward radial diffusion, convection of plasma sheet electrons, or transport of trapped electrons by enhanced convection electric field represented by the Volland-Stern model or a uniform dawn-dusk electric field model based on the electric field measurements. It suggests that the underlying physical mechanism responsible for energetic electron deep penetration, which is very important for fully understanding energetic electron dynamics in the low L shells, should be MLT localized.

[Penetrating injuries in the face and neck region. Diagnosis and treatment].

PubMed

Maier, H; Tisch, M; Lorenz, K J; Danz, B; Schramm, A

2011-08-01

Penetrating head and neck injuries often present with vascular lesions and airway compromise and may be life-threatening. Thus controlling bleeding and airway stabilisation take priority in emergency treatment. High-velocity projectiles, fragmentations from improvised explosive devices (IEDs) and shrapnel can cause severe tissue injury, representing a challenge for the head and neck surgeon. Since several organ structures, such as the eyes, midface, pharynx, larynx, trachea, esophagus, nerves, vessels and vertebral spine can be injured at the same time, patients should be referred to a specialized trauma center for interdisciplinary treatment following emergency treatment. High-speed ballistic injuries were once confined to the battle field and have been uncommon in Europe since World War II. For this reason, experience among civilian head and neck surgeons is at present limited. With the increased incidence of terrorism and the use of IEDs as the preferred weapon in terrorism it has become important for civilian head and neck surgeons to understand the role of ballistic injuries in mass casualty events. The present paper discusses current viewpoints in the diagnosis and treatment of penetrating head and neck injuries.

Antimicrobial Penetration and Efficacy in an In Vitro Oral Biofilm Model ▿ †

PubMed Central

Corbin, Audrey; Pitts, Betsey; Parker, Albert; Stewart, Philip S.

2011-01-01

The penetration and overall efficacy of six mouthrinse actives was evaluated by using an in vitro flow cell oral biofilm model. The technique involved preloading biofilm cells with a green fluorescent dye that leaked out as the cells were permeabilized by a treatment. The loss of green color, and of biomass, was observed by time-lapse microscopy during 60 min of treatment under continuous flow conditions. The six actives analyzed were ethanol, sodium lauryl sulfate, triclosan, chlorhexidine digluconate (CHX), cetylpyridinium chloride, and nisin. Each of these agents effected loss of green fluorescence throughout biofilm cell clusters, with faster action at the edge of a cell cluster and slower action in the cluster center. The time to reach half of the initial fluorescent intensity at the center of a cell cluster, which can be viewed as a combined penetration and biological action time, ranged from 0.6 to 19 min for the various agents. These times are much longer than the predicted penetration time based on diffusion alone, suggesting that anti-biofilm action was controlled more by the biological action time than by the penetration time of the active. None of the agents tested caused any removal of the biofilm. The extent of fluorescence loss after 1 h of exposure to an active ranged from 87 to 99.5%, with CHX being the most effective. The extent of fluorescence loss in vitro, but not penetration and action time, correlated well with the relative efficacy data from published clinical trials. PMID:21537022

Measurement of in-situ strength using projectile penetration: Tests of a new launching system

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

Hearst, J.R.; Newmark, R.L.; Charest, J.A.

1987-10-01

The Lawrence Livermore National Laboratory has a continuing need to measure rock strength in situ, both for simple prediction of cavity size, and as input to computational models. In a previous report we compared two methods for measuring formation strength in situ: projectile penetration and a cone penetrometer. We determined that the projectile method was more promising for application to our large-diameter (2-4-m) hole environment. A major practical problem has been the development of a launcher and an apparatus for measuring depth of penetration that would be suitable for use in large-diameter holes. We are developing a gas-gun launcher systemmore » that will be capable of measuring both depth of penetration and deceleration of a reusable projectile. The current version of the launcher is trailer-mounted for testing at our Nevada Test Site (NTS) in tunnels and outcrops, but its design is such that it can be readily adapted for emplacement hole use. We test the current launcher on 60-cm cubes of gypsum cement, mixed to provie a range of densities (1.64 to 2.0 g/cc) and strengths (3 to 17 MPa). We compared depth of penetration of a 84-g projectile from a ''Betsy'' seismic gun - traveling on the order of 500 m/s - with the depth of penetration of a 13-kg projectile from the gas gun - traveling on the order of 30 m/s. For projectiles with the same nose size and shape, impacting targets of approximately constant strength, penetration depth was proportional to projectile kinetic energy. The ratio of kinetic energy to penetration depth was approximately proportional to target strength. Tests in tuffs with a wide range of strengths at NTS gave a similar linear relationship between the ratio of kinetic energy to penetration and target strength, and also a linear relationship between deceleration and strength. It appears that penetration can indeed be used as a semiquantitative measure of strength.« less

Evaluating the safety impact of adaptive cruise control in traffic oscillations on freeways.

PubMed

Li, Ye; Li, Zhibin; Wang, Hao; Wang, Wei; Xing, Lu

2017-07-01

Adaptive cruise control (ACC) has been considered one of the critical components of automated driving. ACC adjusts vehicle speeds automatically by measuring the status of the ego-vehicle and leading vehicle. Current commercial ACCs are designed to be comfortable and convenient driving systems. Little attention is paid to the safety impacts of ACC, especially in traffic oscillations when crash risks are the highest. The primary objective of this study was to evaluate the impacts of ACC parameter settings on rear-end collisions on freeways. First, the occurrence of a rear-end collision in a stop-and-go wave was analyzed. A car-following model in an integrated ACC was developed for a simulation analysis. The time-to-collision based factors were calculated as surrogate safety measures of the collision risk. We also evaluated different market penetration rates considering that the application of ACC will be a gradual process. The results showed that the safety impacts of ACC were largely affected by the parameters. Smaller time delays and larger time gaps improved safety performance, but inappropriate parameter settings increased the collision risks and caused traffic disturbances. A higher reduction of the collision risk was achieved as the ACC vehicle penetration rate increased, especially in the initial stage with penetration rates of less than 30%. This study also showed that in the initial stage, the combination of ACC and a variable speed limit achieved better safety improvements on congested freeways than each single technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

Penetration length-dependent hot electrons in the field emission from ZnO nanowires

NASA Astrophysics Data System (ADS)

Chen, Yicong; Song, Xiaomeng; Li, Zhibing; She, Juncong; Deng, Shaozhi; Xu, Ningsheng; Chen, Jun

2018-01-01

In the framework of field emission, whether or not hot electrons can form in the semiconductor emitters under a surface penetration field is of great concern, which will provide not only a comprehensive physical picture of field emission from semiconductor but also guidance on how to improve device performance. However, apart from some theoretical work, its experimental evidence has not been reported yet. In this article, the field penetration length-dependent hot electrons were observed in the field emission of ZnO nanowires through the in-situ study of its electrical and field emission characteristic before and after NH3 plasma treatment in an ultrahigh vacuum system. After the treatment, most of the nanowires have an increased carrier density but reduced field emission current. The raised carrier density was caused by the increased content of oxygen vacancies, while the degraded field emission current was attributed to the lower kinetic energy of hot electrons caused by the shorter penetration length. All of these results suggest that the field emission properties of ZnO nanowires can be optimized by modifying their carrier density to balance both the kinetic energy of field induced hot electrons and the limitation of saturated current under a given field.

Prediction of electric vehicle penetration.

DOT National Transportation Integrated Search

2017-05-01

The object of this report is to present the current market status of plug-in-electric : vehicles (PEVs) and to predict their future penetration within the world and U.S. : markets. The sales values for 2016 show a strong year of PEV sales both in the...

Magnetic Penetration Effects in Small Superconducting Devices

NASA Technical Reports Server (NTRS)

Stevenson, T. R.; Adams, J. S.; Balvin, M. A.; Bandler, S. R.; Denis, K. L.; Hsieh, W.-T.; Kelly, D. P.; Nagler, P. C.; Porst, J.-P.; Sadleir, J. E.;

Rates of cuticular penetration of chelated Fe(III): role of humidity, concentration, adjuvants, temperature, and type of chelate.

PubMed

Schönherr, Jörg; Fernández, Victoria; Schreiber, Lukas

2005-06-01

Time courses of cuticular penetration of FeCl3 and Fe(III) complexes of citric acid, EDTA, EDDHA (Sequestrene 138Fe), imidodisuccinic acid (IDHA), and ligninsulfonic acid (Natrel) were studied using astomatous cuticular membranes (CMs) isolated from Populus x canescens leaves. At 100% relative humidity, the Fe(III) chelates disappeared exponentially with time from the surface of the CMs; that is, penetration was a first-order process that can be described using rate constants or half-times of penetration (t(1/2)). Half-times ranged from 20 to 30 h. At 90% humidity, penetration rates were insignificant with the exception of Natrel, for which t(1/2) amounted to 58 h. Rate constants were independent of temperature (15, 25, and 35 degrees C). Permeability decreased with increasing Fe chelate concentration (IDHA and EDTA). At 100% humidity, half-times measured with FeIDHA were 11 h (2 mmol L(-1)), 17 h (10 mmol L(-1)) and 36 h (20 mmol L(-1)), respectively. In the presence of FeEDTA, penetration of CaCl2 was slowed greatly. Half-times for penetration of CaCl2, which were 1.9 h in the absence of FeEDTA, rose to 3.12 h in the presence of an equimolar concentration of EDTA and 13.3 h when the FeEDTA concentration was doubled. Hence, Fe chelates reduced permeability of CMs to CaCl2 and to the Fe chelates themselves. It is suggested that Fe chelates reduced the size of aqueous pores. This view is supported by the fact that rate constants for calcium salts were about 5 times higher than for Fe chelates with the same molecular weights. Adding Tween 20 (5 g L(-1)) as a humectant did not increase permeability to FeIDHA at 90% humidity and below, while addition of glycine betaine did. Penetration of FeCl3 applied at 5 g L(-1) (pH 1.5) was not a first order process as rate constants decreased rapidly with time. Only 2% of the dose penetrated during the first 2 h and less than that in the subsequent 8 h. Recovery was only 70%. This was attributed to the formation of insoluble Fe hydroxide precipitates on CMs. These results explain why in the past foliar application of Fe compounds had limited success. Inorganic Fe salts are instable and phytotoxic because of low pH, while Fe chelates penetrate slowly and 100% humidity is required for significant penetration rates. Concentrations as low as reasonably possible should be used. These physical facts are expected to apply to stomatous leaf surfaces as well, but absolute rates probably depend on leaf age and plant species. High humidity in stagnant air layers may favor penetration rates across stomatous leaf surfaces when humidity in bulk air is below 100%.

Update of correlations between cone penetration and boring log data : technical summary report.

DOT National Transportation Integrated Search

2009-12-01

The main objective of this project is to update the correlations that are currently used to interpret : Cone Penetration Test (CPT) data for engineering design purposes and to assess the reliability of : using CPT data to predict soil shear strength....

Studying the effectiveness of penetration enhancers to deliver retinol through the stratum cornum by in vivo confocal Raman spectroscopy.

PubMed

Mélot, Mickaël; Pudney, Paul D A; Williamson, Ann-Marie; Caspers, Peter J; Van Der Pol, Andre; Puppels, Gerwin J

2009-08-19

The purpose of this study is to monitor in vivo the effect of chemical penetration enhancers on the delivery of trans-retinol into human skin. Chemical penetration enhancers reversibly alter barrier properties of the SC by disruption of the membrane structures or maximising drug solubility with the skin. So far, most of permeation or penetration experiments are performed in vitro. Raman spectroscopy is uniquely placed to be able to measure biological processes in vivo and this paper shows for the first time that the effect of penetration enhancer on the delivery of trans-retinol can successfully be measured in vivo using this technique. Here, the volar forearm of volunteers was treated with four formulations. One formulation is a highly effective model delivery system identified from ex vivo experiments: trans-retinol in Propylene Glycol (PG)/ethanol, with PG being a well-known and efficient penetration enhancer. The other three formulations are based on 0.3% trans-retinol in Caprylic/Capric Acid Triglyceride (MYRITOL 318), an oil commonly used in skin creams but in two of them a specific penetration enhancer is added. One contains a lipid extractor, Triton X 100, whereas another formulation contains a lipid fluidiser, Oleic Acid. Solutions were applied once and measurements were performed up to 6 h after treatment. Remarkable differences in the delivery of trans-retinol between formulation with or without penetration enhancer can clearly be seen. Moreover, the type of penetration enhancer is also shown to influence the delivery. While using the Oleic Acid, which is a lipid fluidiser, a better delivery of trans-retinol in the skin can be detected. For the first time, the effect of penetration enhancer on the delivery of trans-retinol has been monitored, non invasively in vivo, with time.

Convective penetration in stars

NASA Astrophysics Data System (ADS)

Pratt, Jane; Baraffe, Isabelle; Goffrey, Tom; Constantino, Tom; Popov, M. V.; Walder, Rolf; Folini, Doris; TOFU Collaboration

To interpret the high-quality data produced from recent space-missions it is necessary to study convection under realistic stellar conditions. We describe the multi-dimensional, time implicit, fully compressible, hydrodynamic, implicit large eddy simulation code MUSIC, currently being developed at the University of Exeter. We use MUSIC to study convection during an early stage in the evolution of our sun where the convection zone covers approximately half of the solar radius. This model of the young sun possesses a realistic stratification in density, temperature, and luminosity. We approach convection in a stellar context using extreme value theory and derive a new model for convective penetration, targeted for one-dimensional stellar evolution calculations. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework (FP7/2007-2013)/ERC Grant agreement no. 320478.

PHARYNGEAL SWALLOWING MECHANICS SECONDARY TO HEMISPHERIC STROKE

PubMed Central

May, Nelson H; Pisegna, Jessica M; Marchina, Sarah; Langmore, Susan E; Kumar, Sandeep; Pearson, William G

2016-01-01

Goals Computational Analysis of Swallowing Mechanics is a method that utilizes multivariate shape change analysis to uncover covariant elements of pharyngeal swallowing mechanics associated with impairment using videofluoroscopic swallowing studies. The goals of this preliminary study were to (1) characterize swallowing mechanics underlying stroke related dysphagia, (2) decipher the impact of left and right hemispheric stroke on pharyngeal swallowing mechanics, and (3) determine pharyngeal swallowing mechanics associated with penetration-aspiration status. Materials and Methods Videofluoroscopic swallowing studies of 18 dysphagic patients with hemispheric infarcts and age and gender matched controls were selected from well-controlled data sets. Patient data including laterality, and penetration-aspiration status was collected. Coordinates mapping muscle group action during swallowing were collected from videos. Multivariate morphometric analyses of coordinates associated with stroke, affected hemisphere, and penetration-aspiration status were performed. Findings Pharyngeal swallowing mechanics differed significantly in the following comparisons: stroke vs. controls (D=2.19, p<.0001); right hemispheric stroke vs. controls (D=3.64, p<.0001); left hemispheric stroke vs. controls (D=2.06, p<.0001); right hemispheric stroke vs. left hemispheric stroke (D=2.89, p<.0001); and penetration-aspiration vs. within normal limits (D=2.25, p<.0001). Differences in pharyngeal swallowing mechanics associated with each comparison were visualized using eigenvectors. Conclusion While current literature focuses on timing changes in stroke-related dysphagia, this data suggests that mechanical changes are also functionally important. Pharyngeal swallowing mechanics differed by affected hemisphere and penetration-aspiration status. Computational Analysis of Swallowing Mechanics can be used to identify patient specific swallowing impairment associated with stroke injury that could help guide rehabilitation strategies to improve swallowing outcomes. PMID:27913200

L-band InSAR Penetration Depth Experiment, North Slope Alaska

NASA Astrophysics Data System (ADS)

Muskett, Reginald

2017-04-01

Since the first spacecraft-based synthetic aperture radar (SAR) mission NASA's SEASAT in 1978 radars have been flown in Low Earth Orbit (LEO) by other national space agencies including the Canadian Space Agency, European Space Agency, India Space Research Organization and the Japanese Aerospace Exploration Agency. Improvements in electronics, miniaturization and production have allowed for the deployment of SAR systems on aircraft for usage in agriculture, hazards assessment, land-use management and planning, meteorology, oceanography and surveillance. LEO SAR systems still provide a range of needful and timely information on large and small-scale weather conditions like those found across the Arctic where ground-base weather radars currently provide limited coverage. For investigators of solid-earth deformation attention must be given to the atmosphere on Interferometric SAR (InSAR) by aircraft and spacecraft multi-pass operations. Because radar has the capability to penetrate earth materials at frequencies from the P- to X-band attention must be given to the frequency dependent penetration depth and volume scattering. This is the focus of our new research project: to test the penetration depth of L-band SAR/InSAR by aircraft and spacecraft systems at a test site in Arctic Alaska using multi-frequency analysis and progressive burial of radar mesh-reflectors at measured depths below tundra while monitoring environmental conditions. Knowledge of the L-band penetration depth on lowland Arctic tundra is necessary to constrain analysis of carbon mass balance and hazardous conditions arising form permafrost degradation and thaw, surface heave and subsidence and thermokarst formation at local and regional scales.

Semi-Automated Trajectory Analysis of Deep Ballistic Penetrating Brain Injury

PubMed Central

Folio, Les; Solomon, Jeffrey; Biassou, Nadia; Fischer, Tatjana; Dworzak, Jenny; Raymont, Vanessa; Sinaii, Ninet; Wassermann, Eric M.; Grafman, Jordan

2016-01-01

Background Penetrating head injuries (PHIs) are common in combat operations and most have visible wound paths on computed tomography (CT). Objective We assess agreement between an automated trajectory analysis-based assessment of brain injury and manual tracings of encephalomalacia on CT. Methods We analyzed 80 head CTs with ballistic PHI from the Institutional Review Board approved Vietnam head injury registry. Anatomic reports were generated from spatial coordinates of projectile entrance and terminal fragment location. These were compared to manual tracings of the regions of encephalomalacia. Dice’s similarity coefficients, kappa, sensitivities, and specificities were calculated to assess agreement. Times required for case analysis were also compared. Results Results show high specificity of anatomic regions identified on CT with semiautomated anatomical estimates and manual tracings of tissue damage. Radiologist’s and medical students’ anatomic region reports were similar (Kappa 0.8, t-test p < 0.001). Region of probable injury modeling of involved brain structures was sensitive (0.7) and specific (0.9) compared with manually traced structures. Semiautomated analysis was 9-fold faster than manual tracings. Conclusion Our region of probable injury spatial model approximates anatomical regions of encephalomalacia from ballistic PHI with time-saving over manual methods. Results show potential for automated anatomical reporting as an adjunct to current practice of radiologist/neurosurgical review of brain injury by penetrating projectiles. PMID:23707123

Potential impacts of electric vehicles on air quality in Taiwan.

PubMed

Li, Nan; Chen, Jen-Ping; Tsai, I-Chun; He, Qingyang; Chi, Szu-Yu; Lin, Yi-Chiu; Fu, Tzung-May

2016-10-01

The prospective impacts of electric vehicle (EV) penetration on the air quality in Taiwan were evaluated using an air quality model with the assumption of an ambitious replacement of current light-duty vehicles under different power generation scenarios. With full EV penetration (i.e., the replacement of all light-duty vehicles), CO, VOCs, NOx and PM2.5 emissions in Taiwan from a fleet of 20.6 million vehicles would be reduced by 1500, 165, 33.9 and 7.2Ggyr(-1), respectively, while electric sector NOx and SO2 emissions would be increased by up to 20.3 and 12.9Ggyr(-1), respectively, if the electricity to power EVs were provided by thermal power plants. The net impacts of these emission changes would be to reduce the annual mean surface concentrations of CO, VOCs, NOx and PM2.5 by about 260, 11.3, 3.3ppb and 2.1μgm(-3), respectively, but to increase SO2 by 0.1ppb. Larger reductions tend to occur at time and place of higher ambient concentrations and during high pollution events. Greater benefits would clearly be attained if clean energy sources were fully encouraged. EV penetration would also reduce the mean peak-time surface O3 concentrations by up to 7ppb across Taiwan with the exception of the center of metropolitan Taipei where the concentration increased by <2ppb. Furthermore, full EV penetration would reduce annual days of O3 pollution episodes by ~40% and PM2.5 pollution episodes by 6-10%. Our findings offer important insights into the air quality impacts of EV and can provide useful information for potential mitigation actions. Copyright © 2016 Elsevier B.V. All rights reserved.

DIFFERENCES IN MENTAL HEALTH AND SEXUAL OUTCOMES BASED ON TYPE OF NONCONSENUAL SEXUAL PENETRATION

PubMed Central

Pinsky, Hanna T.; Shepard, Molly E.; Bird, Elizabeth R.; Gilmore, Amanda K.; Norris, Jeanette; Davis, Kelly Cue; George, William H.

2016-01-01

Little is known based on the stratification and localization of penetration type of rape: oral, vaginal, and/or anal. The current study examined associations between type of rape and mental and sexual health symptoms in 865 community women. All penetration types were positively associated with negative mental and sexual health symptoms. Oral and/or anal rape accounted for additional variance in anxiety, depression, some trauma-related symptoms, and dysfunctional sexual behavior than the association with vaginal rape alone. Findings suggest that penetration type can be an important facet of a rape experience and may be useful to assess in research and clinical settings. PMID:27486127

Development of a Plastic Embedding Method for Large-Volume and Fluorescent-Protein-Expressing Tissues

PubMed Central

Yang, Zhongqin; Hu, Bihe; Zhang, Yuhui; Luo, Qingming; Gong, Hui

2013-01-01

Fluorescent proteins serve as important biomarkers for visualizing both subcellular organelles in living cells and structural and functional details in large-volume tissues or organs. However, current techniques for plastic embedding are limited in their ability to preserve fluorescence while remaining suitable for micro-optical sectioning tomography of large-volume samples. In this study, we quantitatively evaluated the fluorescence preservation and penetration time of several commonly used resins in a Thy1-eYFP-H transgenic whole mouse brain, including glycol methacrylate (GMA), LR White, hydroxypropyl methacrylate (HPMA) and Unicryl. We found that HMPA embedding doubled the eYFP fluorescence intensity but required long durations of incubation for whole brain penetration. GMA, Unicryl and LR White each penetrated the brain rapidly but also led to variable quenching of eYFP fluorescence. Among the fast-penetrating resins, GMA preserved fluorescence better than LR White and Unicryl. We found that we could optimize the GMA formulation by reducing the polymerization temperature, removing 4-methoxyphenol and adjusting the pH of the resin solution to be alkaline. By optimizing the GMA formulation, we increased percentage of eYFP fluorescence preservation in GMA-embedded brains nearly two-fold. These results suggest that modified GMA is suitable for embedding large-volume tissues such as whole mouse brain and provide a novel approach for visualizing brain-wide networks. PMID:23577174

Neuroimaging in adult penetrating brain injury: a guide for radiographers

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

Temple, Nikki; Donald, Cortny; Skora, Amanda

Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Basedmore » on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.« less

Anomalous - viscosity current drive

DOEpatents

Stix, Thomas H.; Ono, Masayuki

1988-01-01

An apparatus and method for maintaining a steady-state current in a toroidal magnetically confined plasma. An electric current is generated in an edge region at or near the outermost good magnetic surface of the toroidal plasma. The edge current is generated in a direction parallel to the flow of current in the main plasma and such that its current density is greater than the average density of the main plasma current. The current flow in the edge region is maintained in a direction parallel to the main current for a period of one or two of its characteristic decay times. Current from the edge region will penetrate radially into the plasma and augment the main plasma current through the mechanism of anomalous viscosity. In another aspect of the invention, current flow driven between a cathode and an anode is used to establish a start-up plasma current. The plasma-current channel is magnetically detached from the electrodes, leaving a plasma magnetically insulated from contact with any material obstructions including the cathode and anode.

Wind-driven changes of surface current, temperature, and chlorophyll observed by satellites north of New Guinea

NASA Astrophysics Data System (ADS)

Radenac, Marie-Hélène; Léger, Fabien; Messié, Monique; Dutrieux, Pierre; Menkes, Christophe; Eldin, Gérard

2016-04-01

Satellite observations of wind, sea level and derived currents, sea surface temperature (SST), and chlorophyll are used to expand our understanding of the physical and biological variability of the ocean surface north of New Guinea. Based on scarce cruise and mooring data, previous studies differentiated a trade wind situation (austral winter) when the New Guinea Coastal Current (NGCC) flows northwestward and a northwest monsoon situation (austral summer) when a coastal upwelling develops and the NGCC reverses. This circulation pattern is confirmed by satellite observations, except in Vitiaz Strait where the surface northwestward flow persists. We find that intraseasonal and seasonal time scale variations explain most of the variance north of New Guinea. SST and chlorophyll variabilities are mainly driven by two processes: penetration of Solomon Sea waters and coastal upwelling. In the trade wind situation, the NGCC transports cold Solomon Sea waters through Vitiaz Strait in a narrow vein hugging the coast. Coastal upwelling is generated in westerly wind situations (westerly wind event, northwest monsoon). Highly productive coastal waters are advected toward the equator and, during some westerly wind events, toward the eastern part of the warm pool. During El Niño, coastal upwelling events and northward penetration of Solomon Sea waters combine to influence SST and chlorophyll anomalies.

Quasi-static time-series simulation using OpenDSS in IEEE distribution feeder model with high PV penetration and its impact on solar forecasting

NASA Astrophysics Data System (ADS)

Mohammed, Touseef Ahmed Faisal

Since 2000, renewable electricity installations in the United States (excluding hydropower) have more than tripled. Renewable electricity has grown at a compounded annual average of nearly 14% per year from 2000-2010. Wind, Concentrated Solar Power (CSP) and solar Photo Voltaic (PV) are the fastest growing renewable energy sectors. In 2010 in the U.S., solar PV grew over 71% and CSP grew by 18% from the previous year. Globally renewable electricity installations have more than quadrupled from 2000-2010. Solar PV generation grew by a factor of more than 28 between 2000 and 2010. The amount of CSP and solar PV installations are increasing on the distribution grid. These PV installations transmit electrical current from the load centers to the generating stations. But the transmission and distribution grid have been designed for uni-directional flow of electrical energy from generating stations to load centers. This causes imbalances in voltage and switchgear of the electrical circuitry. With the continuous rise in PV installations, analysis of voltage profile and penetration levels remain an active area of research. Standard distributed photovoltaic (PV) generators represented in simulation studies do not reflect the exact location and variability properties such as distance between interconnection points to substations, voltage regulators, solar irradiance and other environmental factors. Quasi-Static simulations assist in peak load planning hour and day ahead as it gives a time sequence analysis to help in generation allocation. Simulation models can be daily, hourly or yearly depending on duty cycle and dynamics of the system. High penetration of PV into the power grid changes the voltage profile and power flow dynamically in the distribution circuits due to the inherent variability of PV. There are a number of modeling and simulations tools available for the study of such high penetration PV scenarios. This thesis will specifically utilize OpenDSS, a open source Distribution System Simulator developed by Electric Power Research Institute, to simulate grid voltage profile with a large scale PV system under quasi-static time series considering variations of PV output in seconds, minutes, and the average daily load variations. A 13 bus IEEE distribution feeder model is utilized with distributed residential and commercial scale PV at different buses for simulation studies. Time series simulations are discussed for various modes of operation considering dynamic PV penetration at different time periods in a day. In addition, this thesis demonstrates simulations taking into account the presence of moving cloud for solar forecasting studies.

Dependence of electron peak current on hollow cathode dimensions and seed electron energy in a pseudospark discharge

NASA Astrophysics Data System (ADS)

Cetiner, S. O.; Stoltz, P.; Messmer, P.; Cambier, J.-L.

2008-01-01

The prebreakdown and breakdown phases of a pseudospark discharge are investigated using the two-dimensional kinetic plasma simulation code OOPIC™ PRO. Trends in the peak electron current at the anode are presented as function of the hollow cathode dimensions and mean seed injection velocities at the cavity back wall. The plasma generation process by ionizing collisions is examined, showing the effect on supplying the electrons that determine the density of the beam. The mean seed velocities used here are varied between the velocity corresponding to the energy of peak ionization cross section, 15 times this value and no mean velocity (i.e., electrons injected with a temperature of 2.5eV). The reliance of the discharge characteristics on the penetrating electric field is shown to decrease as the mean seed injection velocity increases because of its ability to generate a surplus plasma independent of the virtual anode. As a result, the peak current increases with the hollow cathode dimensions for the largest average injection velocity, while for the smallest value it increases with the area of penetration of the electric field in the hollow cathode interior. Additionally, for a given geometry an increase in the peak current with the surplus plasma generated is observed. For the largest seed injection velocity used a dependence of the magnitude of the peak current on the ratio of the hole thickness and hollow cathode depth to the hole height is demonstrated. This means similar trends of the peak current are generated when the geometry is resized. Although the present study uses argon only, the variation in the discharge dependencies with the seed injection energy relative to the ionization threshold is expected to apply independently of the gas type. Secondary electrons due to electron and ion impact are shown to be important only for the largest impact areas and discharge development times of the study.

Scoria Cone and Tuff Ring Stratigraphy Interpreted from Ground Penetrating Radar, Rattlesnake Crater, Arizona

NASA Astrophysics Data System (ADS)

Kruse, S. E.; McNiff, C. M.; Marshall, A. M.; Courtland, L. M.; Connor, C.; Charbonnier, S. J.; Abdollahzadeh, M.; Connor, L.; Farrell, A. K.; Harburger, A.; Kiflu, H. G.; Malservisi, R.; Njoroge, M.; Nushart, N.; Richardson, J. A.; Rookey, K.

2013-12-01

Numerous recent studies have demonstrated that detailed investigation of scoria cone and maar morphology can reveal rich details the eruptive and erosion histories of these volcanoes. A suite of geophysical surveys were conducted to images Rattlesnake Crater in the San Francisco Volcanic Field, AZ, US. We report here the results of ~3.4 km of ground penetrating radar (GPR) surveys that target the processes of deposition and erosion on the pair of cinder cones that overprint the southeast edge of Rattlesnake crater and on the tuff ring that forms the crater rim. Data were collected with 500, 250, 100, and 50 MHz antennas. The profiles were run in a radial direction down the northeast flanks of the cones (~1 km diameter, ~120 meters height) , and on the inner and outer margins of the oblong maar rim (~20-80 meters height). A maximum depth of penetration of GPR signal of ~15m was achieved high on the flanks of scoria cones. A minimum depth of essentially zero penetration occurred in the central crater. We speculate that maximum penetration occurs near the peaks of the cones and crater rim because ongoing erosion limits new soil formation. Soil formation would tend to increase surface conductivity and hence decrease GPR penetration. Soil is probably better developed within the crater, precluding significant radar penetration there. On the northeast side of the gently flattened rim of the easternmost scoria cone, the GPR profile shows internal layering that dips ~20 degrees northeast relative to the current ground surface. This clearly indicates that the current gently dipping surface is not a stratigraphic horizon, but reflects instead an erosive surface into cone strata that formed close to the angle of repose. Along much of the cone flanks GPR profiles show strata dipping ~4-5 degrees more steeply than the current surface, suggesting erosion has occurred over most of the height of the cone. An abrupt change in strata attitude is observed at the gradual slope diminishment at the base of the scoria cone, where the dip of GPR reflectors changes from radially out from the cone to horizontal or radially inward toward the cone. These changes suggest that grain avalanche packages thin at the base of the slope or that cone strata terminate against the pre-existing surface. We do not identify continuous tephra fall deposits extending from the base of the cone, which would be indicative of violent strombolian activity. On one profile strong diffractors at the base of the cone suggest the presence of now-buried ballistics that rolled to the bottom of the slope. A major question to be addressed with the GPR data is whether the scoria cone erosion by downslope granular flow can be modeled using the diffusion-advection equation with constant diffusivity and advection terms, and in contrast, how much of the profile is explained by downslope movement at the time of the eruption. GPR reflecting horizons on the maar rim are smoother in appearance than those on the scoria cone, perhaps indicating finer-grained material and the absence of diffracting blocks. On the west rim layers suggest indicated a paleo-rim with a flat top ~50 meters wide, surrounded on both sides by strata dipping more steeply than the current surface. Radar stratgraphy outside the northeastern maar rim is much more complex.

Multipoint Observations of Energetic Particle Injections and Substorm Activity During a Conjunction Between Magnetospheric Multiscale (MMS) and Van Allen Probes

NASA Astrophysics Data System (ADS)

Turner, D. L.; Fennell, J. F.; Blake, J. B.; Claudepierre, S. G.; Clemmons, J. H.; Jaynes, A. N.; Leonard, T.; Baker, D. N.; Cohen, I. J.; Gkioulidou, M.; Ukhorskiy, A. Y.; Mauk, B. H.; Gabrielse, C.; Angelopoulos, V.; Strangeway, R. J.; Kletzing, C. A.; Le Contel, O.; Spence, H. E.; Torbert, R. B.; Burch, J. L.; Reeves, G. D.

2017-11-01

This study examines multipoint observations during a conjunction between Magnetospheric Multiscale (MMS) and Van Allen Probes on 7 April 2016 in which a series of energetic particle injections occurred. With complementary data from Time History of Events and Macroscale Interactions during Substorms, Geotail, and Los Alamos National Laboratory spacecraft in geosynchronous orbit (16 spacecraft in total), we develop new insights on the nature of energetic particle injections associated with substorm activity. Despite this case involving only weak substorm activity (maximum AE <300 nT) during quiet geomagnetic conditions in steady, below-average solar wind, a complex series of at least six different electron injections was observed throughout the system. Intriguingly, only one corresponding ion injection was clearly observed. All ion and electron injections were observed at <600 keV only. MMS reveals detailed substructure within the largest electron injection. A relationship between injected electrons with energy <60 keV and enhanced whistler mode chorus wave activity is also established from Van Allen Probes and MMS. Drift mapping using a simplified magnetic field model provides estimates of the dispersionless injection boundary locations as a function of universal time, magnetic local time, and L shell. The analysis reveals that at least five electron injections, which were localized in magnetic local time, preceded a larger injection of both electrons and ions across nearly the entire nightside of the magnetosphere near geosynchronous orbit. The larger ion and electron injection did not penetrate to L < 6.6, but several of the smaller electron injections penetrated to L < 6.6. Due to the discrepancy between the number, penetration depth, and complexity of electron versus ion injections, this event presents challenges to the current conceptual models of energetic particle injections.

Multipoint Observations of Energetic Particle Injections and Substorm Activity During a Conjunction Between Magnetospheric Multiscale (MMS) and Van Allen Probes

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

Turner, Drew L.; Fennell, J. F.; Blake, J. B.

Here, this study examines multipoint observations during a conjunction between Magnetospheric Multiscale (MMS) and Van Allen Probes on 7 April 2016 in which a series of energetic particle injections occurred. With complementary data from Time History of Events and Macroscale Interactions during Substorms, Geotail, and Los Alamos National Laboratory spacecraft in geosynchronous orbit (16 spacecraft in total), we develop new insights on the nature of energetic particle injections associated with substorm activity. Despite this case involving only weak substorm activity (maximum AE <300 nT) during quiet geomagnetic conditions in steady, below-average solar wind, a complex series of at least sixmore » different electron injections was observed throughout the system. Intriguingly, only one corresponding ion injection was clearly observed. All ion and electron injections were observed at <600 keV only. MMS reveals detailed substructure within the largest electron injection. A relationship between injected electrons with energy <60 keV and enhanced whistler mode chorus wave activity is also established from Van Allen Probes and MMS. Drift mapping using a simplified magnetic field model provides estimates of the dispersionless injection boundary locations as a function of universal time, magnetic local time, and L shell. The analysis reveals that at least five electron injections, which were localized in magnetic local time, preceded a larger injection of both electrons and ions across nearly the entire nightside of the magnetosphere near geosynchronous orbit. The larger ion and electron injection did not penetrate to L < 6.6, but several of the smaller electron injections penetrated to L < 6.6. Due to the discrepancy between the number, penetration depth, and complexity of electron versus ion injections, this event presents challenges to the current conceptual models of energetic particle injections.« less

Multipoint Observations of Energetic Particle Injections and Substorm Activity During a Conjunction Between Magnetospheric Multiscale (MMS) and Van Allen Probes

DOE PAGES

Turner, Drew L.; Fennell, J. F.; Blake, J. B.; ...

2017-09-25

Here, this study examines multipoint observations during a conjunction between Magnetospheric Multiscale (MMS) and Van Allen Probes on 7 April 2016 in which a series of energetic particle injections occurred. With complementary data from Time History of Events and Macroscale Interactions during Substorms, Geotail, and Los Alamos National Laboratory spacecraft in geosynchronous orbit (16 spacecraft in total), we develop new insights on the nature of energetic particle injections associated with substorm activity. Despite this case involving only weak substorm activity (maximum AE <300 nT) during quiet geomagnetic conditions in steady, below-average solar wind, a complex series of at least sixmore » different electron injections was observed throughout the system. Intriguingly, only one corresponding ion injection was clearly observed. All ion and electron injections were observed at <600 keV only. MMS reveals detailed substructure within the largest electron injection. A relationship between injected electrons with energy <60 keV and enhanced whistler mode chorus wave activity is also established from Van Allen Probes and MMS. Drift mapping using a simplified magnetic field model provides estimates of the dispersionless injection boundary locations as a function of universal time, magnetic local time, and L shell. The analysis reveals that at least five electron injections, which were localized in magnetic local time, preceded a larger injection of both electrons and ions across nearly the entire nightside of the magnetosphere near geosynchronous orbit. The larger ion and electron injection did not penetrate to L < 6.6, but several of the smaller electron injections penetrated to L < 6.6. Due to the discrepancy between the number, penetration depth, and complexity of electron versus ion injections, this event presents challenges to the current conceptual models of energetic particle injections.« less

Penetration of the Interplanetary Magnetic Field B(sub y) into Earth's Plasma Sheet

NASA Technical Reports Server (NTRS)

Hau, L.-N.; Erickson, G. M.

1995-01-01

There has been considerable recent interest in the relationship between the cross-tail magnetic field component B(sub y) and tail dynamics. The purpose of this paper is to give an overall description of the penetration of the interplanetary magnetic field (IMF) B(sub y) into the near-Earth plasma sheet. We show that plasma sheet B(sub y) may be generated by the differential shear motion of field lines and enhanced by flux tube compression. The latter mechanism leads to a B(sub y) analogue of the pressure-balance inconsistency as flux tubes move from the far tail toward the Earth. The growth of B(sub y), however, may be limited by the dawn-dusk asymmetry in the shear velocity as a result of plasma sheet tilting. B(sub y) penetration into the plasma sheet implies field-aligned currents flowing between hemispheres. These currents together with the IMF B(sub y) related mantle field-aligned currents effectively shield the lobe from the IMF B(sub y).

Redox flow batteries with serpentine flow fields: Distributions of electrolyte flow reactant penetration into the porous carbon electrodes and effects on performance

NASA Astrophysics Data System (ADS)

Ke, Xinyou; Prahl, Joseph M.; Alexander, J. Iwan D.; Savinell, Robert F.

2018-04-01

Redox flow batteries with flow field designs have been demonstrated to boost their capacities to deliver high current density and power density in medium and large-scale energy storage applications. Nevertheless, the fundamental mechanisms involved with improved current density in flow batteries with serpentine flow field designs have been not fully understood. Here we report a three-dimensional model of a serpentine flow field over a porous carbon electrode to examine the distributions of pressure driven electrolyte flow penetrations into the porous carbon electrodes. We also estimate the maximum current densities associated with stoichiometric availability of electrolyte reactant flow penetrations through the porous carbon electrodes. The results predict reasonably well observed experimental data without using any adjustable parameters. This fundamental work on electrolyte flow distributions of limiting reactant availability will contribute to a better understanding of limits on electrochemical performance in flow batteries with serpentine flow field designs and should be helpful to optimizing flow batteries.

Energy Dependence: The $1.4 Trillion Addiction Threatening National Security

DTIC Science & Technology

2010-02-01

particularly when driving range is not a crucial consideration. 34 This comparison is a metric referred to as the gallon of gasoline equivalent ( GGE ...Currently, retail hydrogen costs between $2.10 and $9.10 GGE . As HFCVs penetrate the market, projected retail cost estimates for hydrogen fuel...range from $1.75 to $4.25 per GGE .35 The HFCV provides size, power, and range capability comparable to the ICE. It also “achieves two times the

Modeling Jupiter's current disc - Pioneer 10 outbound

NASA Astrophysics Data System (ADS)

Jones, D. E.; Melville, J. G.; Blake, M. L.

1980-07-01

A model of the magnetic field of the Jovian current disk is presented. The model uses Euler functions and the Biot-Savart law applied to a series of concentric, but not necessarily coplanar current rings. It was found that the best fit to the Pioneer 10 outbound perturbation magnetic field data is obtained if the current disk is twisted, and also bent to tend toward parallelism with the Jovigraphic equator. The inner and outer radii of the disk appear to be about 7 and 150 Jovian radii, respectively; because of the observed current disk penetrations, the bent disk also requires a deformation in the form of a bump or wrinkle whose axis tends to exhibit spiraling. Modeling of the azimuthal field shows that it is due to a thin radial current sheet, but it may actually be due in large part to penetration of a tail current sheet as suggested by Voyager observations.

Effect of Egg Washing and Correlation between Eggshell Characteristics and Egg Penetration by Various Salmonella Typhimurium Strains

PubMed Central

Gole, Vaibhav C.; Chousalkar, Kapil K.; Roberts, Juliet R.; Sexton, Margaret; May, Damian; Tan, Jessica; Kiermeier, Andreas

2014-01-01

Salmonella is an important foodborne pathogen, causing an estimated 11,992 cases of infection in Australia per year. Egg or egg product related salmonellosis is a major concern for the egg industry. Worldwide, S. Typhimurium is one of the most common serovars identified in Salmonella food poisoning cases. The current study investigated the ability of five S. Typhimurium strains to penetrate washed and unwashed eggs using whole egg and agar egg penetration methods. All S. Typhimurium strains were able to penetrate eggshells and survive in egg albumen (at 20°C) according to whole egg penetration results. Polymerase Chain Reaction results demonstrated that S. Typhimurium strain 2 (103 and 105 CFU/mL), and strain 5 (103 and 105 CFU/mL) egg penetration was significantly higher (p<0.05) in washed eggs when compared to unwashed eggs. Statistical analysis of the agar penetration experiment indicated that S. Typhimurium was able to penetrate washed eggs at a significantly higher rate when compared to unwashed eggs (p<0.05). When compared to unwashed eggs, washed eggs also had significantly damaged cuticles. Statistical analysis also indicated that eggshell penetration by S. Typhimurium was related to various eggshell ultrastructural features such as cap quality, alignment, erosion, confluence, Type B bodies and cuticle cover. PMID:24621821

Ground penetrating radar for underground sensing in agriculture: a review

NASA Astrophysics Data System (ADS)

Liu, Xiuwei; Dong, Xuejun; Leskovar, Daniel I.

2016-10-01

Belowground properties strongly affect agricultural productivity. Traditional methods for quantifying belowground properties are destructive, labor-intensive and pointbased. Ground penetrating radar can provide non-invasive, areal, and repeatable underground measurements. This article reviews the application of ground penetrating radar for soil and root measurements and discusses potential approaches to overcome challenges facing ground penetrating radar-based sensing in agriculture, especially for soil physical characteristics and crop root measurements. Though advanced data-analysis has been developed for ground penetrating radar-based sensing of soil moisture and soil clay content in civil engineering and geosciences, it has not been used widely in agricultural research. Also, past studies using ground penetrating radar in root research have been focused mainly on coarse root measurement. Currently, it is difficult to measure individual crop roots directly using ground penetrating radar, but it is possible to sense root cohorts within a soil volume grid as a functional constituent modifying bulk soil dielectric permittivity. Alternatively, ground penetrating radarbased sensing of soil water content, soil nutrition and texture can be utilized to inversely estimate root development by coupling soil water flow modeling with the seasonality of plant root growth patterns. Further benefits of ground penetrating radar applications in agriculture rely on the knowledge, discovery, and integration among differing disciplines adapted to research in agricultural management.

Vaginismus: review of current concepts and treatment using botox injections, bupivacaine injections, and progressive dilation with the patient under anesthesia.

PubMed

Pacik, Peter T

2011-12-01

Vaginismus is a poorly understood condition affecting approximately 1-7% of females worldwide. This article aims to bring attention to this disorder and to review the use of Botox injections to treat these patients. Vaginismus, also known as vaginal penetration disorder, is an aversion to any form of vaginal penetration as a result of painful attempts and a fear of anticipated pain. It is involuntary and uncontrolled and functions much the same as any reflex to avoid injury. It is the most common reason for unconsummated marriages. The etiology is thought to be unknown. Numerous papers note a history of religious or strict sexual upbringing or aversion to penetration because of perceived pain and bleeding with first-time intercourse. Sexual molestation may be more prevalent in this group of patients. The Lamont classification is very helpful in stratifying these patients for treatment. Lamont grade 5 vaginismus is introduced. Vaginal Botox injections for the treatment of vaginismus has received increasing attention since the technique was first described in a 1997 case report. Plastic surgeons worldwide with their experience using Botox are well positioned to learn more about this relatively unknown entity and render treatment.

Active penetration of Trypanosoma cruzi into host cells: historical considerations and current concepts

PubMed Central

de Souza, Wanderley; de Carvalho, Tecia M. Ulisses

2013-01-01

In the present short review, we analyze past experiments that addressed the interactions of intracellular pathogenic protozoa (Trypanosoma cruzi, Toxoplasma gondii, and Plasmodium) with host cells and the initial use of the term active penetration to indicate that a protozoan “crossed the host cell membrane, penetrating into the cytoplasm.” However, the subsequent use of transmission electron microscopy showed that, for all of the protozoans and cell types examined, endocytosis, classically defined as involving the formation of a membrane-bound vacuole, took place during the interaction process. As a consequence, the recently penetrated parasites are always within a vacuole, designated the parasitophorous vacuole (PV). PMID:23355838

Deployable Wireless Camera Penetrators

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

2008-01-01

A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an aerobot or a spacecraft onto a comet or asteroid. A system of 20 of these penetrators could be designed and built in a 1- to 2-kg mass envelope. Possible future modifications of the camera penetrators, such as the addition of a chemical spray device, would allow the study of simple chemical reactions of reagents sprayed at the landing site and looking at the color changes. Zoom lenses also could be added for future use.

Effect of Discontinuities and Penetrations on the Shielding Efficacy of High Temperature Superconducting Magnetic Shields

NASA Astrophysics Data System (ADS)

Hatwar, R.; Kvitkovic, J.; Herman, C.; Pamidi, S.

2015-12-01

High Temperature Superconducting (HTS) materials have been demonstrated to be suitable for applications in shielding of both DC and AC magnetic fields. Magnetic shielding is required for protecting sensitive instrumentation from external magnetic fields and for preventing the stray magnetic fields produced by high power density equipment from affecting neighbouring devices. HTS shields have high current densities at relatively high operating temperatures (40-77 K) and can be easily fabricated using commercial HTS conductor. High current densities in HTS materials allow design and fabrication of magnetic shields that are lighter and can be incorporated into the body and skin of high power density devices. HTS shields are particularly attractive for HTS devices because a single cryogenic system can be used for cooling the device and the associated shield. Typical power devices need penetrations for power and signal cabling and the penetrations create discontinuities in HTS shields. Hence it is important to assess the effect of the necessary discontinuities on the efficacy of the shields and the design modifications necessary to accommodate the penetrations.

Weld pool oscillation during GTA welding of mild steel

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

Xiao, Y.H.; Ouden, G. den

1993-08-01

In this paper the results are reported of a study dealing with the oscillation behavior of weld pools in the case of GTA bead-on-plate welding of mild steel, Fe 360. During welding, the weld pool was brought into oscillation by applying short current pulses, and the oscillation frequency and amplitude were measured by monitoring the arc voltage. It was found that the oscillation of the partially penetrated weld pool is dominated by one of two different oscillation modes (Mode 1 and Mode 2) depending on the welding conditions, whereas the oscillation of the fully penetrated weld pool is characterized bymore » a third oscillation mode (Mode 3). It is possible to maintain partially penetrated weld pool oscillation in Mode 1 by choosing appropriate welding conditions. Under these conditions, an abrupt decrease in oscillation frequency occurs when the weld pool transfers from partial penetration to full penetration. Thus, weld penetration can be in-process controlled by monitoring the oscillation frequency during welding.« less

Setup for investigating gold nanoparticle penetration through reconstructed skin and comparison to published human skin data

NASA Astrophysics Data System (ADS)

Labouta, Hagar I.; Thude, Sibylle; Schneider, Marc

2013-06-01

Owing to the limited source of human skin (HS) and the ethical restrictions of using animals in experiments, in vitro skin equivalents are a possible alternative for conducting particle penetration experiments. The conditions for conducting penetration experiments with model particles, 15-nm gold nanoparticles (AuNP), through nonsealed skin equivalents are described for the first time. These conditions include experimental setup, sterility conditions, effective applied dose determination, skin sectioning, and skin integrity check. Penetration at different exposure times (two and 24 h) and after tissue fixation (fixed versus unfixed skin) are examined to establish a benchmark in comparison to HS in an attempt to get similar results to HS experiments presented earlier. Multiphoton microscopy is used to detect gold luminescence in skin sections. λex=800 nm is used for excitation of AuNP and skin samples, allowing us to determine a relative index for particle penetration. Despite the observed overpredictability of penetration into skin equivalents, they could serve as a first fast screen for testing the behavior of nanoparticles and extrapolate their penetration behavior into HS. Further investigations are required to test a wide range of particles of different physicochemical properties to validate the skin equivalent-human skin particle penetration relationship.

Pharyngeal Swallowing Mechanics Secondary to Hemispheric Stroke.

PubMed

May, Nelson H; Pisegna, Jessica M; Marchina, Sarah; Langmore, Susan E; Kumar, Sandeep; Pearson, William G

2017-05-01

Computational analysis of swallowing mechanics (CASM) is a method that utilizes multivariate shape change analysis to uncover covariant elements of pharyngeal swallowing mechanics associated with impairment using videofluoroscopic swallowing studies. The goals of this preliminary study were to (1) characterize swallowing mechanics underlying stroke-related dysphagia, (2) decipher the impact of left and right hemispheric strokes on pharyngeal swallowing mechanics, and (3) determine pharyngeal swallowing mechanics associated with penetration-aspiration status. Videofluoroscopic swallowing studies of 18 dysphagic patients with hemispheric infarcts and age- and gender-matched controls were selected from well-controlled data sets. Patient data including laterality and penetration-aspiration status were collected. Coordinates mapping muscle group action during swallowing were collected from videos. Multivariate morphometric analyses of coordinates associated with stroke, affected hemisphere, and penetration-aspiration status were performed. Pharyngeal swallowing mechanics differed significantly in the following comparisons: stroke versus controls (D = 2.19, P < .0001), right hemispheric stroke versus controls (D = 3.64, P < .0001), left hemispheric stroke versus controls (D = 2.06, P < .0001), right hemispheric stroke versus left hemispheric stroke (D = 2.89, P < .0001), and penetration-aspiration versus within normal limits (D = 2.25, P < .0001). Differences in pharyngeal swallowing mechanics associated with each comparison were visualized using eigenvectors. Whereas current literature focuses on timing changes in stroke-related dysphagia, these data suggest that mechanical changes are also functionally important. Pharyngeal swallowing mechanics differed by the affected hemisphere and the penetration-aspiration status. CASM can be used to identify patient-specific swallowing impairment associated with stroke injury that could help guide rehabilitation strategies to improve swallowing outcomes. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

L-band InSAR Penetration Depth Experiment, North Slope Alaska

NASA Astrophysics Data System (ADS)

Muskett, R. R.

2017-12-01

Since the first spacecraft-based synthetic aperture radar (SAR) mission NASA's SEASAT in 1978 radars have been flown in Low Earth Orbit (LEO) by other national space agencies including the Canadian Space Agency, European Space Agency, India Space Research Organization and the Japanese Aerospace Exploration Agency. Improvements in electronics, miniaturization and production have allowed for the deployment of SAR systems on aircraft for usage in agriculture, hazards assessment, land-use management and planning, meteorology, oceanography and surveillance. LEO SAR systems still provide a range of needful and timely information on large and small-scale weather conditions like those found across the Arctic where ground-base weather radars currently provide limited coverage. For investigators of solid-earth deformation attention must be given to the atmosphere on Interferometric SAR (InSAR) by aircraft and spacecraft multi-pass operations. Because radar has the capability to penetrate earth materials at frequencies from the P- to X-band attention must be given to the frequency dependent penetration depth and volume scattering. This is the focus of our new research project: to test the penetration depth of L-band SAR/InSAR by aircraft and spacecraft systems at a test site in Arctic Alaska using multi-frequency analysis and progressive burial of radar mesh-reflectors at measured depths below tundra while monitoring environmental conditions. Knowledge of the L-band penetration depth on lowland Arctic tundra is necessary to constrain analysis of carbon mass balance and hazardous conditions arising form permafrost degradation and thaw, surface heave and subsidence and thermokarst formation at local and regional scales. Ref.: Geoscience and Environment Protection, vol. 5, no. 3, p. 14-30, 2017. DOI: 10.4236/gep.2017.53002.

Analysis of the processes occurring in a submicrosecond discharge with a linear current density of up to 3 MA/cm through a thick-wall stainless-steel electrode

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

Branitsky, A. V.; Grabovski, E. V.; Dzhangobegov, V. V.

The state of conductors carrying a megampere current from the generator to the load is studied experimentally. It is found that the plasma produced from cylindrical stainless-steel tubes during the passage of a submicrosecond current pulse with a linear density of 3 MA/cm expands with a velocity of 5.5 km/s. Numerical results on the diffusion of the magnetic field induced by a current with a linear density of 1–3MA/cm into metal electrodes agree with the experimental data on the penetration time of the magnetic field. For a linear current density of 3.1 MA/cm, the experimentally determined electric field strength onmore » the inner surface of the tube is 4 kV/cm. The calculated electric field strength on the inner surface of the tube turns out to be two times higher, which can be explained by plasma production on the outer and inner surfaces of the electrode.« less

High-quality weather data for grid integration studies

NASA Astrophysics Data System (ADS)

Draxl, C.

2016-12-01

As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. In this talk we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather prediction to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets will be presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The Solar Integration National Dataset (SIND) is available as time synchronized with the WIND Toolkit, and will allow for combined wind-solar grid integration studies. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. Grid integration studies are also carried out in various countries, which aim at increasing their wind and solar penetration through combined wind and solar integration data sets. We will present a multi-year effort to directly support India's 24x7 energy access goal through a suite of activities aimed at enabling large-scale deployment of clean energy and energy efficiency. Another current effort is the North-American-Renewable-Integration-Study, with the aim of providing a seamless data set across borders for a whole continent, to simulate and analyze the impacts of potential future large wind and solar power penetrations on bulk power system operations.

Thoracic and respirable particle definitions for human health risk assessment.

PubMed

Brown, James S; Gordon, Terry; Price, Owen; Asgharian, Bahman

2013-04-10

Particle size-selective sampling refers to the collection of particles of varying sizes that potentially reach and adversely affect specific regions of the respiratory tract. Thoracic and respirable fractions are defined as the fraction of inhaled particles capable of passing beyond the larynx and ciliated airways, respectively, during inhalation. In an attempt to afford greater protection to exposed individuals, current size-selective sampling criteria overestimate the population means of particle penetration into regions of the lower respiratory tract. The purpose of our analyses was to provide estimates of the thoracic and respirable fractions for adults and children during typical activities with both nasal and oral inhalation, that may be used in the design of experimental studies and interpretation of health effects evidence. We estimated the fraction of inhaled particles (0.5-20 μm aerodynamic diameter) penetrating beyond the larynx (based on experimental data) and ciliated airways (based on a mathematical model) for an adult male, adult female, and a 10 yr old child during typical daily activities and breathing patterns. Our estimates show less penetration of coarse particulate matter into the thoracic and gas exchange regions of the respiratory tract than current size-selective criteria. Of the parameters we evaluated, particle penetration into the lower respiratory tract was most dependent on route of breathing. For typical activity levels and breathing habits, we estimated a 50% cut-size for the thoracic fraction at an aerodynamic diameter of around 3 μm in adults and 5 μm in children, whereas current ambient and occupational criteria suggest a 50% cut-size of 10 μm. By design, current size-selective sample criteria overestimate the mass of particles generally expected to penetrate into the lower respiratory tract to provide protection for individuals who may breathe orally. We provide estimates of thoracic and respirable fractions for a variety of breathing habits and activities that may benefit the design of experimental studies and interpretation of particle size-specific health effects.

Thoracic and respirable particle definitions for human health risk assessment

PubMed Central

2013-01-01

Background Particle size-selective sampling refers to the collection of particles of varying sizes that potentially reach and adversely affect specific regions of the respiratory tract. Thoracic and respirable fractions are defined as the fraction of inhaled particles capable of passing beyond the larynx and ciliated airways, respectively, during inhalation. In an attempt to afford greater protection to exposed individuals, current size-selective sampling criteria overestimate the population means of particle penetration into regions of the lower respiratory tract. The purpose of our analyses was to provide estimates of the thoracic and respirable fractions for adults and children during typical activities with both nasal and oral inhalation, that may be used in the design of experimental studies and interpretation of health effects evidence. Methods We estimated the fraction of inhaled particles (0.5-20 μm aerodynamic diameter) penetrating beyond the larynx (based on experimental data) and ciliated airways (based on a mathematical model) for an adult male, adult female, and a 10 yr old child during typical daily activities and breathing patterns. Results Our estimates show less penetration of coarse particulate matter into the thoracic and gas exchange regions of the respiratory tract than current size-selective criteria. Of the parameters we evaluated, particle penetration into the lower respiratory tract was most dependent on route of breathing. For typical activity levels and breathing habits, we estimated a 50% cut-size for the thoracic fraction at an aerodynamic diameter of around 3 μm in adults and 5 μm in children, whereas current ambient and occupational criteria suggest a 50% cut-size of 10 μm. Conclusions By design, current size-selective sample criteria overestimate the mass of particles generally expected to penetrate into the lower respiratory tract to provide protection for individuals who may breathe orally. We provide estimates of thoracic and respirable fractions for a variety of breathing habits and activities that may benefit the design of experimental studies and interpretation of particle size-specific health effects. PMID:23575443

If I had a magic wand....Wish list of a dermatologist (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kelly, Kristen M.

2016-02-01

Challenges in dermatology that can be addressed by photonics research will be explored. Non-invasive, real-time diagnosis of skin lesions would eliminate biopsy risks, minimize patient anxiety by providing more rapid answers and allow diagnosis and treatment in a single visit. Multiple approaches have been tried, but significant limitations of current technologies make them impractical for routine clinic implementation. Photonics can also be used for treatment assessment to determine if intervention is adequate or if further treatment is needed. Ideal feedback should be non-invasive, rapid and accurate. Monitoring for potential adverse effects can greatly improve treatment safety, allowing clinicians to push the limits of therapy while preventing serious complications. Light based therapies can also be improved by increasing photon penetration and selectivity for targeted cells or skin structures. Current light based treatments are in many cases limited by photon penetration. In addition, we often seek to damage a specific chromophore but are not able to distinguish between targeted disease and non-targeted normal structures such as the cells of a melanoma and normal melanocytes and port wine stain versus normal vasculature. Scientist and clinician collaboration can address these and other issues and greatly improve patient care.

The DSM diagnostic criteria for dyspareunia.

PubMed

Binik, Yitzchak M

2010-04-01

The DSM-IV-TR attempted to create a unitary category of dyspareunia based on the criterion of genital pain that interfered with sexual intercourse. This classificatory emphasis of interference with intercourse is reviewed and evaluated from both theoretical and empirical points of view. Neither of these points of view was found to support the notion of dyspareunia as a unitary disorder or its inclusion in the DSM-V as a sexual dysfunction. It seems highly likely that there are different syndromes of dyspareunia and that what is currently termed "superficial dyspareunia" cannot be differentiated reliably from vaginismus. It is proposed that the diagnoses of vaginismus and dyspareunia be collapsed into a single diagnostic entity called genito-pelvic pain/penetration disorder. This diagnostic category is defined according to five dimensions: percentage success of vaginal penetration; pain with vaginal penetration; fear of vaginal penetration or of genito-pelvic pain during vaginal penetration; pelvic floor muscle dysfunction; medical co-morbidity.

IDA Gamma-Ray Laser Annual Summary Report (1985). Investigation of the Feasibility of Developing a Laser Using Nuclear Transitions. Revised.

DTIC Science & Technology

1986-06-01

beams of coherent radiation whose short wavelengths would permit greater penetration of matter than is possible with current laser sources. With that...nuclear linewidth. It is claimed that the time required for any narrowing is at least as long as the inverse of the linewidth achieved, no matter what...with the re- quired narrow line can be prepared is a different matter . The point is that the previous uncertainty principle does not forbid the

Radial flow to a partially penetrating well with storage in an anisotropic confined aquifer

NASA Astrophysics Data System (ADS)

Mishra, Phoolendra Kumar; Vesselinov, Velimir V.; Neuman, Shlomo P.

2012-07-01

SummaryDrawdowns generated by extracting water from large diameter (e.g. water supply) well are affected by wellbore storage. We present an analytical solution in Laplace transformed space for drawdown in a uniform anisotropic aquifer caused by withdrawing water at a constant rate from partially penetrating well with storage. The solution is back transformed into the time domain numerically. When the pumping well is fully penetrating our solution reduces to that of Papadopulos and Cooper (1967); Hantush (1964) when the pumping well has no wellbore storage; Theis (1935) when both conditions are fulfilled and Yang (2006) when the pumping well is partially penetrating, has finite radius but lacks storage. Newly developed solution is then used to explore graphically the effects of partial penetration, wellbore storage and anisotropy on time evolutions of drawdown in the pumping well and in observation wells. We concluded after validating the developed analytical solution using synthetic pumping test.

Space station integrated wall design and penetration damage control. Task 4: Impact detection/location system

NASA Technical Reports Server (NTRS)

Nelson, J. M.; Lempriere, B. M.

1987-01-01

A program to develop a methodology is documented for detecting and locating meteoroid and debris impacts and penetrations of a wall configuration currently specified for use on space station. Testing consisted of penetrating and non-penetrating hypervelocity impacts on single and dual plate test configurations, including a prototype 1.22 m x 2.44 m x 3.56 mm (4 ft x 8 ft x 0.140 in) aluminum waffle grid backwall with multilayer insulation and a 0.063-in shield. Acoustic data were gathered with transducers and associated data acquisition systems and stored for later analysis with a multichannel digitizer. Preliminary analysis of test data included sensor evaluation, impact repeatability, first waveform arrival, and Fourier spectral analysis.

Assessing the Ability of Ground-Penetrating Radar to Detect Fungal Decay in Douglas-Fir Beams

Treesearch

Christopher Adam Senalik; James Wacker; Xiping Wang; F. Jalinoos

2016-01-01

This paper describes the testing plan and current progress for assessing the efficacy of using ground-penetrating radar (GPR) to detect fungal decay within Douglas-fir beams. Initially, the beams were assessed using a variety of physical, mechanical, and nondestructive evaluation (NDE) test methods including micro-resistance drilling, Janka hardness, ultrasonic...

Effect of Liquid Penetrant Sensitivity on Probability of Detection

NASA Technical Reports Server (NTRS)

Parker, Bradford H.

2011-01-01

The objective of the task is to investigate the effect of liquid penetrant sensitivity level on probability of detection (POD) of cracks in various metals. NASA-STD-5009 currently requires the use of only sensitivity level 4 liquid penetrants for NASA Standard Level inspections. This requirement is based on the fact that the data used to establish the reliably detectable flaw sizes penetrant inspection was from studies performed in the 1970s using penetrant deemed to be equivalent only to modern day sensitivity level 4 penetrants. However, many NDE contractors supporting NASA Centers routinely use sensitivity level 3 penetrants. Because of the new NASA-STD-5009 requirement, these contractors will have to either shift to sensitivity level 4 penetrants or perform formal POD demonstration tests to qualify their existing process. We propose a study to compare the POD generated for two penetrant manufactures, Sherwin and Magnaflux, and for the two most common penetrant inspection methods, water washable and post emulsifiable, hydrophilic. NDE vendors local to GSFC will be employed. A total of six inspectors will inspect a set of crack panels with a broad range of fatigue crack sizes. Each inspector will perform eight inspections of the panel set using the combination of methods and sensitivity levels described above. At least one inspector will also perform multiple inspections using a fixed technique to investigate repeatability. The hit/miss data sets will be evaluated using both the NASA generated DOEPOD software and the MIL-STD-1823 software.

Three-Step Buildup of the 17 March 2015 Storm Ring Current: Implication for the Cause of the Unexpected Storm Intensification

NASA Astrophysics Data System (ADS)

Keika, Kunihiro; Seki, Kanako; Nosé, Masahito; Miyoshi, Yoshizumi; Lanzerotti, Louis J.; Mitchell, Donald G.; Gkioulidou, Matina; Manweiler, Jerry W.

2018-01-01

We examine the spatiotemporal variations of the energy density and the energy spectral evolution of energetic ions in the inner magnetosphere during the main phase of the 17 March 2015 storm, using data from the RBSPICE and EMFISIS instruments onboard Van Allen Probes. The storm developed in response to two southward IMF intervals separated by about 3 h. In contrast to two steps seen in the Dst/SYM-H index, the ring current ion population evolved in three steps: the first subphase was apparently caused by the earlier southward IMF, and the subsequent subphases occurred during the later southward IMF period. Ion energy ranges that contribute to the ring current differed between the three subphases. We suggest that the spectral evolution resulted from the penetration of different plasma sheet populations. The ring current buildup during the first subphase was caused by the penetration of a relatively low-energy population that had existed in the plasma sheet during a prolonged prestorm northward IMF interval. The deeper penetration of the lower-energy population was responsible for the second subphase. The third subphase, where the storm was unexpectedly intensified to a Dst/SYM-H level of <-200 nT, was caused by the penetration of a hot, dense plasma sheet population. We attribute the hot, dense population to the entry of hot, dense solar wind into the plasma sheet and/or ion heating/acceleration in the near-Earth plasma sheet associated with magnetotail activity such as reconnection and dipolarization.

Effect of Target Thickness on Cratering and Penetration of Projectiles Impacting at Velocities to 13,000 Feet Per Second

NASA Technical Reports Server (NTRS)

Kinard, William H.; Lambert, C. H., Jr.; Schryer, David R.; Casey, Francis W., Jr.

1958-01-01

In order to determine the effects of target thickness on the penetration and cratering of a target resulting from impacts by high-velocity projectiles, a series of experimental tests have been run. The projectile-target material combinations investigated were aluminum projectiles impacting aluminum targets and steel projectiles impacting aluminum and copper targets. The velocity spectrum ranged from 4,000 ft/sec to 13,000 ft/sec. It has been found that the penetration is a function of target thickness provided that the penetration is greater than 20 percent of the target thickness. Targets of a thickness such that the penetration amounts to less than 20 percent of the thickness may be regarded as quasi-infinite. An empirical formula has been established relating the penetration to the target thickness and to the penetration of a projectile of the same mass, configuration, and velocity into a quasi- infinite target. In particular, it has been found that a projectile can completely penetrate a target whose thickness is approximately one and one-half times as great as the penetration of a similar projectile into a quasi-infinite target. The diameter of a crater has also been found to be a function of the target thickness provided that the target thickness is not greater than the projectile length in the case of cylindrical projectiles and not greater than two to three times the projectile diameter in the case of spherical projectiles.

The Current Status of the Japanese Penetrator Mission: LUNAR-A

NASA Astrophysics Data System (ADS)

Tanaka, S.; Shiraishi, H.; Fujimura, A.; Hayakawa, H.

The scientific objective of the LUNAR-A, Japanese Penetrator Mission, is to explore the lunar interior by seismic and heat-flow experiments. Two penetrators containing two seismometers (horizontal and vertical components) and heat-flow probes will be deployed from a spacecraft onto the lunar surface, one on the nearside and the other on the farside of the moon. The final impact velocity of the penetrator will be about 300m/sec; it will encounter a shock of about 8000 G at impact on the lunar surface. According to numerous experimental impact tests using model penetrators and a lunar regolith analog target, each penetrator is predicted to penetrate to a depth of 1 to 3 m. The data obtained by the penetrators will be transmitted to the earth station via the LUNAR-A mother spacecraft orbiting at an altitude of about 200 km. The penetrator is a missile-shaped instrument carrier, which is about 14cm in diameter, 75cm in length, and about 14kg in weight without attitude control system. It contains a two-component seismometer and heat flow probes together with other supporting instruments such as a tilt meter and an accelerometer. The seismic observations are expected to provide key data on the size of the lunar core, as well as data on deep lunar mantle structure. The heat flow measurements at two penetrator deployment sites will also provide important data on the thermal structure and bulk concentrations of heat-generating elements in the Moon. These data will provide much stronger geophysical constraints on the origin and evolution of the Moon than has been obtained so far. The LUNAR-A spacecraft was supposed to be launched in the summer of 2004, but it was postponed due to the necessity of a replacement of the valves used in the RCS propulsion system of the spacecraft, following a recall issued by the manufacturer who found a malfunction of similar valves. Then, the technological review boards by ISAS and JAXA recommended that both the more robustness of the communication link, between the penetrator and the orbiting spacecraft, and the improvement of data processing unit onboard penetrator should be made. And also, in compliance with the recommendation by the external review board, we have made a decision to suspend a development of LUNAR-A spacecraft and to concentrate on the completion of the penetrator technology. To solve the above technological issues, it was estimated to take a couple of years. In this paper, we present the current status of development and some results of the impact tests for component level models and for the full-size integrated model, which both are modified and re-designed.

Reduction of asymmetric wall force in ITER disruptions with fast current quench

NASA Astrophysics Data System (ADS)

Strauss, H.

2018-02-01

One of the problems caused by disruptions in tokamaks is the asymmetric electromechanical force produced in conducting structures surrounding the plasma. The asymmetric wall force in ITER asymmetric vertical displacement event (AVDE) disruptions is calculated in nonlinear 3D MHD simulations. It is found that the wall force can vary by almost an order of magnitude, depending on the ratio of the current quench time to the resistive wall magnetic penetration time. In ITER, this ratio is relatively low, resulting in a low asymmetric wall force. In JET, this ratio is relatively high, resulting in a high asymmetric wall force. Previous extrapolations based on JET measurements have greatly overestimated the ITER wall force. It is shown that there are two limiting regimes of AVDEs, and it is explained why the asymmetric wall force is different in the two limits.

Laser Hole Boring into Overdense Plasma and Relativistic Electron Currents for Fast Ignition of ICF Targets

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

Pukhov, A.; Meyer-ter-Vehn, J.

Laser hole boring and relativistic electron transport into plasma of 10 times critical density is studied by means of 2D particle-in-cell simulation. At intensities of I{sub 0}{lambda}{sup 2}=10{sup 20} W(cm){sup {minus}2} {mu}m{sup 2}, a channel 12{lambda} deep and 3{lambda} in diameter has formed after 200 laser cycles. The laser driven electron current carries up to 40{percent} of the incident laser power. When penetrating the overdense region, it breaks up into several filaments at early times, but is channeled into a single magnetized jet later on. These features are essential for fast ignition of targets for inertial confinement fusion (ICF). {copyright}more » {ital 1997} {ital The American Physical Society}« less

Photoacoustic Analysis of the Penetration Kinetics of Cordia verbenacea DC in Human Skin

NASA Astrophysics Data System (ADS)

Carvalho, S. S.; Barja, P. R.

2012-11-01

Phonophoresis consists of the utilization of ultrasound radiation associated to pharmacological agents in order to enhance transdermal penetration of applied drugs. It is a widely employed resource in physiotherapy practice, normally associated with anti-inflammatory drugs, such as Acheflan. This drug was developed in Brazil from the essential oil of Cordia verbenacea DC, a native plant of the Brazilian southern coast. In previous studies, the photoacoustic (PA) technique proved effective in the study of the penetration kinetics of topically applied products and in the evaluation of drug delivery after phonophoresis application. The present work aimed to evaluate the penetration kinetics of Acheflan in human skin, employing in vivo PA measurements after massage application or phonophoresis application. Ten volunteers (aged between 18 and 30 years) took part in the study. Time evolution of the PA signal was fitted to a Boltzmann curve, S-shaped. After statistical analysis, PA measurements have shown drug penetration for both application forms, but drug delivery was more evident after phonophoresis application, with a characteristic penetration time of less than 15 min for the stratum corneum.

Experimental investigation of internal short circuits in lithium-ion batteries

NASA Astrophysics Data System (ADS)

Poramapojana, Poowanart

With outstanding performance of Lithium-ion batteries, they have been widely used in many applications. For hybrid electric vehicles and electric vehicles, customer concerns of battery safety have been raised as a number of car accidents were reported. To evaluate safety performance of these batteries, a nail penetration test is used to simulate and induce internal short circuits instantaneously. Efforts to explain failure mechanisms of the penetration using electrochemical-thermal coupled models have been proposed. However, there is no experimental validation because researchers lack of a diagnostic tool to acquire important cell characteristics at a shorting location, such as shorting current and temperature. In this present work, diagnostic nails have been developed to acquire nail center temperatures and shorting current flow through the nails during nail penetration tests. Two types of cylindrical wall structures are used to construct the nails: a double-layered stainless steel wall and a composite cylindrical wall. An inner hollow cylinder functions as a sensor holder where two wires and one thermocouple are installed. To study experimental reproducibility and repeatability of experimental results, two nail penetration tests are conducted using two diagnostic nails with the double-layered wall. Experimental data shows that the shorting resistance at the initial stage is a critical parameter to obtain repeatable results. The average shorting current for both tests is approximately 40 C-rate. The fluctuation of the shorting current is due to random sparks and fire caused loose contacts between the nail and the cell components. Moreover, comparative experimental results between the two wall structures reveal that the wall structure does not affect the cell characteristics and Ohmic heat generation of the nail. The wall structure effects to current measurements inside the nail. With the composite wall, the actual current redistribution into the inner wall is found to be a sinusoidal waveform.

Nanoparticle filtration performance of NIOSH-certified particulate air-purifying filtering facepiece respirators: evaluation by light scattering photometric and particle number-based test methods.

PubMed

Rengasamy, Samy; Eimer, Benjamin C

2012-01-01

National Institute for Occupational Safety and Health (NIOSH) certification test methods employ charge neutralized NaCl or dioctyl phthalate (DOP) aerosols to measure filter penetration levels of air-purifying particulate respirators photometrically using a TSI 8130 automated filter tester at 85 L/min. A previous study in our laboratory found that widely different filter penetration levels were measured for nanoparticles depending on whether a particle number (count)-based detector or a photometric detector was used. The purpose of this study was to better understand the influence of key test parameters, including filter media type, challenge aerosol size range, and detector system. Initial penetration levels for 17 models of NIOSH-approved N-, R-, and P-series filtering facepiece respirators were measured using the TSI 8130 photometric method and compared with the particle number-based penetration (obtained using two ultrafine condensation particle counters) for the same challenge aerosols generated by the TSI 8130. In general, the penetration obtained by the photometric method was less than the penetration obtained with the number-based method. Filter penetration was also measured for ambient room aerosols. Penetration measured by the TSI 8130 photometric method was lower than the number-based ambient aerosol penetration values. Number-based monodisperse NaCl aerosol penetration measurements showed that the most penetrating particle size was in the 50 nm range for all respirator models tested, with the exception of one model at ~200 nm size. Respirator models containing electrostatic filter media also showed lower penetration values with the TSI 8130 photometric method than the number-based penetration obtained for the most penetrating monodisperse particles. Results suggest that to provide a more challenging respirator filter test method than what is currently used for respirators containing electrostatic media, the test method should utilize a sufficient number of particles <100 nm and a count (particle number)-based detector.

Estimation of the optimal timing of fertilization for embryo development of in vitro-matured bovine oocytes based on the times of nuclear maturation and sperm penetration.

PubMed

Koyama, Keisuke; Kang, Sung-Sik; Huang, Weiping; Yanagawa, Yojiro; Takahashi, Yoshiyuki; Nagano, Masashi

2014-05-01

The objective of this research was to estimate the optimal timing for fertilization to achieve proper embryonic development of in vitro-matured bovine oocytes. First, cumulus-oocyte complexes were subjected to in vitro maturation (IVM) for 14-22 hr. The timing when 50% of oocytes reached metaphase II stage was estimated to be 17.5 hr after IVM start. Next, using oocytes subjected to IVM for 12-30 hr, sperm penetration was examined after 4-18 hr of in vitro fertilization (IVF). A significant negative correlation between IVM duration and the timing when 50% of oocytes were penetrated by sperm after IVF start was observed (P<0.01). Finally, oocytes subjected to 12-30 hr of IVM were inseminated and cultured for 6 days to examine embryonic development. In the group with 22 hr of IVM, the percentages of cleaved embryos and blastocysts were the highest values in all groups. According to the regression equation describing the time from nuclear maturation to sperm penetration (x) and the percentage of blastocysts (y) (y=7.23x - 0.297x(2), P<0.01), the blastocyst rate peaked when sperm penetration occurred at 12.2 hr after achieving nuclear maturation. In conclusion, under the present IVM/IVF conditions, it was estimated that oocytes acquired their highest developmental competence at about 30 hr after IVM start, and thus, the optimal IVM duration was calculated to be about 21 hr.

Campbell penetration depth in Fe-based superconductors

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

Prommapan, Plegchart

A 'true' critical current density, j c, as opposite to commonly measured relaxed persistent (Bean) current, j B, was extracted from the Campbell penetration depth, Λ c(T,H) measured in single crystals of LiFeAs, and optimally electron-doped Ba(Fe 0.954Ni 0.046) 2As 2 (FeNi122). In LiFeAs, the effective pinning potential is nonparabolic, which follows from the magnetic field - dependent Labusch parameter α. At the equilibrium (upon field - cooling), α(H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamicmore » explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of jc(2 K) ≅ 1.22 x 10 6 A/cm 2 provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and pnictides. In addition to LiFeAs, we also report the magnetic penetration depth in BaFe 2As 2 based superconductors including irradiation of FeNi122. In unirradiated FeNi122, the maximum critical current value is, j c(2K) ≅ 3.3 x 10 6 A/cm 2. The magnetic-dependent feature was observed near the transition temperature in FeTe 0.53Se 0.47 and irradiated FeNi122. Because of this feature, further studies are required in order to properly calibrate the Campbell penetration depth. Finally, we detected the crossing between the magnetic penetration depth and London penetration depth in optimally hold-doped Ba 0.6K 0.4Fe 2As 2 (BaK122) and isovalent doped BaFe 2(As 0.7P 0.3) 2 (BaP122). These phenomena probably coincide with anomalous Meissner effect reported in pnicitde superconductors [Prozorov et al. (2010b)] however more studies are needed in order to clarify this.« less

Campbell penetration depth in iron-based superconductors

NASA Astrophysics Data System (ADS)

Prommapan, Plengchart

2011-12-01

A "true" critical current density, jc, as opposite to commonly measured relaxed persistent (Bean) current, jB, was extracted from the Campbell penetration depth, lambda C(T, H) measured in single crystals of LiFeAs, and optimally electron-doped Ba (Fe0.954Ni 0.046)2As2 (FeNi122). In LiFeAs, the effective pinning potential is non-parabolic, which follows from the magnetic field - dependent Labusch parameter alpha. At the equilibrium (upon field - cooling), alpha( H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamic explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of j c (2 K) ≃ 1:22 x106 A/cm² provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and pnictides. In addition to LiFeAs, we also report the magnetic penetration depth in BaFe2As2 based superconductors including irradiation of FeNi122. In unirradiated FeNi122, the maximum critical current value is, jc(2 K) ≃ 3.3 x 106 A/cm². The magnetic-dependent feature was observed near the transition temperature in FeTe0.53Se0.47 and irradiated FeNi122. Because of this feature, further studies are required in order to properly calibrate the Campbell penetration depth. Finally, we detected the crossing between the magnetic penetration depth and London penetration depth in optimally hold-doped Ba0.6K 0.4Fe2As2 (BaK122) and isovalent doped BaFe2(As0.7P0.3)2 (BaP122). These phenomena probably coincide with anomalous Meissner effect reported in pnictide superconductors [Prozorov et al. (2010b)] however more studies are needed in order to clarify this.

Ballistic V50 Evaluation of TIMET Ti108

DTIC Science & Technology

2018-02-01

complete penetration (CP) or partial penetration (PP). Since a CP was determined on the initial shots of both projectiles, the impact velocities...Ti-108 Material Target Data Shot Time: Results X-Ray Times Residual Velocity: Phantom Velocity: Launch Package: Total (grams) Case Size: Expected...H16168-5 Ti-108 Material Target Data Shot Time: Results X-Ray Times Residual Velocity: Phantom Velocity: Launch Package: Total (grams) Case Size

Prehospital interventions for penetrating trauma victims: a prospective comparison between Advanced Life Support and Basic Life Support.

PubMed

Seamon, Mark J; Doane, Stephen M; Gaughan, John P; Kulp, Heather; D'Andrea, Anthony P; Pathak, Abhijit S; Santora, Thomas A; Goldberg, Amy J; Wydro, Gerald C

2013-05-01

Advanced Life Support (ALS) providers may perform more invasive prehospital procedures, while Basic Life Support (BLS) providers offer stabilisation care and often "scoop and run". We hypothesised that prehospital interventions by urban ALS providers prolong prehospital time and decrease survival in penetrating trauma victims. We prospectively analysed 236 consecutive ambulance-transported, penetrating trauma patients an our urban Level-1 trauma centre (6/2008-12/2009). Inclusion criteria included ICU admission, length of stay >/=2 days, or in-hospital death. Demographics, clinical characteristics, and outcomes were compared between ALS and BLS patients. Single and multiple variable logistic regression analysis determined predictors of hospital survival. Of 236 patients, 71% were transported by ALS and 29% by BLS. When ALS and BLS patients were compared, no differences in age, penetrating mechanism, scene GCS score, Injury Severity Score, or need for emergency surgery were detected (p>0.05). Patients transported by ALS units more often underwent prehospital interventions (97% vs. 17%; p<0.01), including endotracheal intubation, needle thoracostomy, cervical collar, IV placement, and crystalloid resuscitation. While ALS ambulance on-scene time was significantly longer than that of BLS (p<0.01), total prehospital time was not (p=0.98) despite these prehospital interventions (1.8 ± 1.0 per ALS patient vs. 0.2 ± 0.5 per BLS patient; p<0.01). Overall, 69.5% ALS patients and 88.4% of BLS patients (p<0.01) survived to hospital discharge. Prehospital resuscitative interventions by ALS units performed on penetrating trauma patients may lengthen on-scene time but do not significantly increase total prehospital time. Regardless, these interventions did not appear to benefit our rapidly transported, urban penetrating trauma patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

High-Obliquity Impact of a Compact Penetrator on a Thin Plate: Penetrator Splitting and Adiabatic Shear

DTIC Science & Technology

1998-01-01

nonideal penetrator on a thin plate at high obliquities. These computations simulated two series of experiments at velocities of 1.5 km/ s and 4.1 km/ s ...3 2. Combined Effects of Obliquity, 0, and Rotation, 4, on Debris Cloud Evolution at 4.1 km/ s and 26 p s ; Impact Velocity Vector Lies in x-z Plane...7 3. Time History of the Penetrator Mass Fraction Exiting the Bottom of the Target at 4.1 km / s

Penetration of boron from topically applied borate solutions

Treesearch

Stan T. Lebow; Patricia K. Lebow; Steven A. Halverson

2010-01-01

Borate penetration relies on diffusion when borate and glycol-borate preservatives are applied to the surface of wood. This study evaluated the extent of borate penetration in framing lumber as a function of preservative formulation, wood moisture content, and diffusion time after treatment. In Phase I of the study, end-matched specimens were conditioned to target...

The role of penetrating gas streams in setting the dynamical state of galaxy clusters

NASA Astrophysics Data System (ADS)

Zinger, E.; Dekel, A.; Birnboim, Y.; Kravtsov, A.; Nagai, D.

2016-09-01

We utilize cosmological simulations of 16 galaxy clusters at redshifts z = 0 and z = 0.6 to study the effect of inflowing streams on the properties of the X-ray emitting intracluster medium. We find that the mass accretion occurs predominantly along streams that originate from the cosmic web and consist of heated gas. Clusters that are unrelaxed in terms of their X-ray morphology are characterized by higher mass inflow rates and deeper penetration of the streams, typically into the inner third of the virial radius. The penetrating streams generate elevated random motions, bulk flows and cold fronts. The degree of penetration of the streams may change over time such that clusters can switch from being unrelaxed to relaxed over a time-scale of several giga years.

SCN5A (NaV1.5) Variant Functional Perturbation and Clinical Presentation: Variants of a Certain Significance.

PubMed

Kroncke, Brett M; Glazer, Andrew M; Smith, Derek K; Blume, Jeffrey D; Roden, Dan M

2018-05-01

Accurately predicting the impact of rare nonsynonymous variants on disease risk is an important goal in precision medicine. Variants in the cardiac sodium channel SCN5A (protein Na V 1.5; voltage-dependent cardiac Na+ channel) are associated with multiple arrhythmia disorders, including Brugada syndrome and long QT syndrome. Rare SCN5A variants also occur in ≈1% of unaffected individuals. We hypothesized that in vitro electrophysiological functional parameters explain a statistically significant portion of the variability in disease penetrance. From a comprehensive literature review, we quantified the number of carriers presenting with and without disease for 1712 reported SCN5A variants. For 356 variants, data were also available for 5 Na V 1.5 electrophysiological parameters: peak current, late/persistent current, steady-state V1/2 of activation and inactivation, and recovery from inactivation. We found that peak and late current significantly associate with Brugada syndrome ( P <0.001; ρ=-0.44; Spearman rank test) and long QT syndrome disease penetrance ( P <0.001; ρ=0.37). Steady-state V1/2 activation and recovery from inactivation associate significantly with Brugada syndrome and long QT syndrome penetrance, respectively. Continuous estimates of disease penetrance align with the current American College of Medical Genetics classification paradigm. Na V 1.5 in vitro electrophysiological parameters are correlated with Brugada syndrome and long QT syndrome disease risk. Our data emphasize the value of in vitro electrophysiological characterization and incorporating counts of affected and unaffected carriers to aid variant classification. This quantitative analysis of the electrophysiological literature should aid the interpretation of Na V 1.5 variant electrophysiological abnormalities and help improve Na V 1.5 variant classification. © 2018 American Heart Association, Inc.

Quantification of nanowire penetration into living cells

NASA Astrophysics Data System (ADS)

Xu, Alexander M.; Aalipour, Amin; Leal-Ortiz, Sergio; Mekhdjian, Armen H.; Xie, Xi; Dunn, Alexander R.; Garner, Craig C.; Melosh, Nicholas A.

2014-04-01

High-aspect ratio nanostructures such as nanowires and nanotubes are a powerful new tool for accessing the cell interior for delivery and sensing. Controlling and optimizing cellular access is a critical challenge for this new technology, yet even the most basic aspect of this process, whether these structures directly penetrate the cell membrane, is still unknown. Here we report the first quantification of hollow nanowires—nanostraws—that directly penetrate the membrane by observing dynamic ion delivery from each 100-nm diameter nanostraw. We discover that penetration is a rare event: 7.1±2.7% of the nanostraws penetrate the cell to provide cytosolic access for an extended period for an average of 10.7±5.8 penetrations per cell. Using time-resolved delivery, the kinetics of the first penetration event are shown to be adhesion dependent and coincident with recruitment of focal adhesion-associated proteins. These measurements provide a quantitative basis for understanding nanowire-cell interactions, and a means for rapidly assessing membrane penetration.

An evaluation of bacterial contamination of barriers used in periapical tissue regeneration: Part 2--Bacterial penetration.

PubMed

Sharma, Priya; Mickel, André K; Chogle, Sami; Sharma, Prem Nath; Han, Yiping W; Jones, Jefferson J

2008-03-01

To compare the relative penetration of Prevotella melaninogenica and Enterococcus faecalis through 3 guided tissue regeneration membranes: Atrisorb, Lambone, and OsseoQuest. It was hypothesized that OsseoQuest would show increased bacterial penetration when compared to Lambone and Atrisorb. Centrifuge tubes containing trypticase soy broth were sealed with circular sections of membranes and placed in test tubes containing culture media. The bacterial penetration was assessed by passage of bacteria from the outer tube culture media to the inner centrifuge tube media through the membrane. After incubation for 4 and 48 hours, the media from the outer and inner tubes were compared for bacterial count. P melaninogenica exhibited 91% penetration for Lambone in 2 days, while OsseoQuest displayed 87% penetration with E faecalis in the same time. Atrisorb displayed a minimal penetration with both bacteria (2%). Atrisorb displayed the least bacterial penetration, which may be attributed to membrane structure, chemical configuration, hydrophobicity, and porosity of tested membranes.

Statistical Mechanical Theory of Penetrant Diffusion in Polymer Melts and Glasses

NASA Astrophysics Data System (ADS)

Zhang, Rui; Schweizer, Kenneth

We generalize our force-level, self-consistent nonlinear Langevin equation theory of activated diffusion of a dilute spherical penetrant in hard sphere fluids to predict the long-time diffusivity of molecular penetrants in supercooled polymer liquids and non-aging glasses. Chemical complexity is treated using an a priori mapping to a temperature-dependent hard sphere mixture model where polymers are disconnected into effective spheres based on the Kuhn length as the relevant coarse graining scale. A key parameter for mobility is the penetrant to polymer segment diameter ratio, R. Our calculations agree well with experimental measurements for a wide range of temperatures, penetrant sizes (from gas molecules with R ~0.3 to aromatic molecules with R ~1) and diverse amorphous polymers, over 10 decades variation of penetrant diffusivity. Structural parameter transferability is good. We have also formulated a theory at finite penetrant loading for the coupled penetrant-polymer dynamics in chemically (nearly) matched mixtures (e.g., toluene-polystyrene) which captures well the increase of penetrant diffusivity and decrease of polymer matrix vitrification temperature with increasing loading.

Toroidal current asymmetry and boundary conditions in disruptions

NASA Astrophysics Data System (ADS)

Strauss, Henry

2014-10-01

It was discovered on JET that disruptions were accompanied by toroidal asymmetry of the plasma current. The toroidal current asymmetry ΔIϕ is proportional to the vertical current moment ΔMIZ , with positive sign for an upward vertical displacement event (VDE) and negative sign for a downward VDE. It was claimed that this could only be explained by Hiro current. It is shown that instead it is essentially a kinematic effect produced by the VDE displacement of a 3D magnetic perturbation. This is verified by M3D simulations. The simulation results do not require penetration of plasma into the boundary, as in the Hiro current model. It is shown that the normal velocity perpendicular to the magnetic field vanishes at the wall, in the small Larmor radius limit of electromagnetic sheath boundary conditions. Plasma is absorbed into the wall only via the parallel velocity, which is small, penetrates only an infinitesimal distance into the wall, and does not affect forces exerted by the plasma on the wall. Supported by USDOE and ITER.

Design and Evaluation of Candidate Pressure Distribution and Air Data System Tile Penetration for the Aeroassist Flight Experiment

NASA Technical Reports Server (NTRS)

Vontheumer, Alfred E.

1990-01-01

This program objectives were to produce a pressure measurements system that penetrates the thermal protection system of a spacecraft and is able to obtain accurate pressure data. The design was tested vibro-acoustically, aerothermally, and structurally and found to be adequate. This design is a possible replacement of the current pressure system on the orbiter.

Current management of penetrating torso trauma: nontherapeutic is not good enough anymore.

PubMed

Ball, Chad G

2014-04-01

A highly organized approach to the evaluation and treatment of penetrating torso injuries based on regional anatomy provides rapid diagnostic and therapeutic consistency. It also minimizes delays in diagnosis, missed injuries and nontherapeutic laparotomies. This review discusses an optimal sequence of structured rapid assessments that allow the clinician to rapidly proceed to gold standard therapies with a minimal risk of associated morbidity.

Psychometric properties of the Blood-borne Virus Transmission Risk Assessment Questionnaire (BBV-TRAQ).

PubMed

Fry, Craig L; Lintzeris, Nick

2003-02-01

To develop a standard measure of blood-borne virus transmission risk behaviour, and examine the underlying psychometric properties. The Blood-borne Virus Transmission Risk Assessment Questionnaire (BBV-TRAQ) was developed over three consecutive phases of the original BBV-TRAQ study in adherence to classical scale development procedures, culminating in the recruitment of a development sample of current injecting drug users via convenience and snowball sampling. Needle and syringe programmes (NSPs), medical clinics, alcohol/drug agencies, peer-based and outreach organizations across inner and outer metropolitan Melbourne. Two hundred and nine current injecting drug users. The mean age was 27 years, 68% were male, 65% unemployed, 36% with prison history and 25% in methadone maintenance. BBV-TRAQ items cover specific injecting, sexual and skin penetration risk practices. BBV-TRAQ characteristics were assessed via measures of internal and test-retest reliability; collateral validation; and principal components analyses. The BBV-TRAQ has satisfactory psychometric properties. Internal (a=0.87), test-retest (r=0.84) and inter-observer reliability results were high, suggesting that the instrument provides a reliable measure of BBV risk behaviour and is reliable over time and across interviewers. A principal components analysis with varimax rotation produced a parsimonious factor solution despite modest communality, and indicated that three factors (injecting, sex and skin penetration/hygiene risks) are required to describe BBV risk behaviour. The BBV-TRAQ is reliable and represents the first risk assessment tool to incorporate sufficient coverage of injecting, sex and other skin penetration risk practices to be considered truly content valid. The questionnaire is indicated for use in addictions research, clinical, peer education and BBV risk behaviour surveillance settings.

Modeling the Environmental Impacts of Potential Oil Pipeline Leaks in the PÁRAMO Region upon the Water Supply for Quito, Ecuador

NASA Astrophysics Data System (ADS)

Gherasim, J.; Sanjinez Guzman, V.; Emerman, S. H.; Tebbs, K. C.

2017-12-01

The Trans-Ecuadorian Pipeline carries crude oil from oilfields in eastern Ecuador to refineries on the Pacific coast, crossing the Páramo region, an alpine tundra ecosystem within the province of Pichincha, which also serves as the water supply for the capital city of Quito. The objective of this study has been to create a model for predicting the likelihood that the effects of a crude oil spill in the Páramo region would impact the water supply of Quito by comparing the residence times of organic compounds in soil with the time required for microbial degradation. A custom MATLAB script included linear partitioning of multiple organic compounds among the water, air, soil and NAPL phases. The three organic compounds considered were anthracene, benzene, and naphthalene. The relevant soil parameters for the Páramo region were obtained from the ISRIC-WISE Harmonized Global Soil Profile Dataset. The soil organic matter content is a critical parameter that was estimated from a very small number of measurements. Residence time half-lives were calculated for depths of penetration of the initial spill ranging from 0.1-5 m. For a depth of penetration of 1 m, residence time half-lives for benzene, naphthalene and anthracene were 1.5, 23.1 and 247.8 years, respectively. Comparing with typical biodegradation half-lives of 10-730 days for benzene, 1-258 days for naphthalene, and 199-252 days for anthracene, it can be seen that penetration to groundwater and transport to the reservoir that supplies water to Quito is unlikely for naphthalene and anthracene, but is a distinct possibility for benzene. Current modeling involves including the effect of volatilization within the soil and improving the estimates of biodegradation rates within an alpine tundra ecosystem. Further results will be reported at the meeting.

Damage to metallic samples produced by measured lightning currents

NASA Technical Reports Server (NTRS)

Fisher, Richard J.; Schnetzer, George H.

1991-01-01

A total of 10 sample disks of 2024-T3 aluminum and 4130 ferrous steel were exposed to rocket-triggered lightning currents at the Kennedy Space Center test site. The experimental configuration was arranged so that the samples were not exposed to the preliminary streamer, wire-burn, or following currents that are associated with an upward-initiated rocket-triggered flash but which are atypical of naturally initiated lightning. Return-stroke currents and continuing currents actually attaching to the sample were measured, augmented by close-up video recordings of approximately 3 feet of the channel above the sample and by 16-mm movies with 5-ms resolution. From these data it was possible to correlate individual damage spots with streamer, return-stroke, and continuing currents that produced them. Substantial penetration of 80-mil aluminum was produced by a continuing current of submedian amplitude and duration, and full penetration of a 35-mil steel sample occurred under an eightieth percentile continuing current. The primary purpose of the data acquired in these experiments is for use in improving and quantifying the fidelity of laboratory simulations of lightning burnthrough.

Use of ground-penetrating radar techniques in archaeological investigations

NASA Technical Reports Server (NTRS)

Doolittle, James A.; Miller, W. Frank

1991-01-01

Ground-penetrating radar (GPR) techniques are increasingly being used to aid reconnaissance and pre-excavation surveys at many archaeological sites. As a 'remote sensing' tool, GPR provides a high resolution graphic profile of the subsurface. Radar profiles are used to detect, identify, and locate buried artifacts. Ground-penetrating radar provides a rapid, cost effective, and nondestructive method for identification and location analyses. The GPR can be used to facilitate excavation strategies, provide greater areal coverage per unit time and cost, minimize the number of unsuccessful exploratory excavations, and reduce unnecessary or unproductive expenditures of time and effort.

Preliminary study of gaseous nitrogen-liquid oxygen mixing and self cleaning

NASA Technical Reports Server (NTRS)

Zuckerwar, A. J.

1985-01-01

The penetration of gaseous nitrogen into liquid oxygen at a pressure of 150 psi was determined by monitoring the composition of the evaporating liquid in a nitrogen analyzer. For pressurization times of about 1 hr the penetration depth varies between 0.0024 and 0.018 in. at an evaporation rate of about 1 gal/day. These are small compared to the penetration depth of 22.2 in. measured in the 7-inch high temperature tunnel at a pressure of 1500 psi, pressurization time of 5 min, and evaporation rate of 121 gal/day.

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

Canavan, G.H.

The optimal allocation of space-based interceptors (SBIs) between fixed, heavy missiles and mobile singlets can be derived from approximate expressions for the boost-phase penetration of each. Singlets can cluster before launch and have shorter burn times, which reduce their availability to SBIs by an order of magnitude. Singlet penetration decreased slowly with the number of SBIs allocated to them; heavy missile penetration falls rapidly. The allocation to the heavy missiles falls linearly with their number. The penetration of heavy and singlet missiles is proportional to their numbers and inversely proportional to their availability. 8 refs., 2 figs.

Pharmacokinetic Study of Piracetam in Focal Cerebral Ischemic Rats.

PubMed

Paliwal, Pankaj; Dash, Debabrata; Krishnamurthy, Sairam

2018-04-01

Cerebral ischemia affects hepatic enzymes and brain permeability extensively. Piracetam was investigated up to phase III of clinical trials and there is lack of data on brain penetration in cerebral ischemic condition. Thus, knowledge of the pharmacokinetics and brain penetration of piracetam during ischemic condition would aid to improve pharmacotherapeutics in ischemic stroke. Focal cerebral ischemia was induced by middle cerebral artery occlusion for 2 h in male Wistar rats followed by reperfusion. After 24 h of middle cerebral artery occlusion or 22 h of reperfusion, piracetam was administered for pharmacokinetic, brain penetration, and pharmacological experiments. In pharmacokinetic study, blood samples were collected at different time points after 200-mg/kg (oral) and 75-mg/kg (intravenous) administration of piracetam through right external jugular vein cannulation. In brain penetration study, the cerebrospinal fluid, systemic blood, portal blood, and brain samples were collected at pre-designated time points after 200-mg/kg oral administration of piracetam. In a separate experiment, the pharmacological effect of the single oral dose of piracetam in middle cerebral artery occlusion was assessed at a dose of 200 mg/kg. All the pharmacokinetic parameters of piracetam including area under curve (AUC 0-24 ), maximum plasma concentration (C max ), time to reach the maximum plasma concentration (t max ), elimination half-life (t 1/2 ), volume of distribution (V z ), total body clearance, mean residence time, and bioavailability were found to be similar in ischemic stroke condition except for brain penetration. Piracetam exposure (AUC 0-2 ) in brain and CSF were found to be 2.4- and 3.1-fold higher, respectively, in ischemic stroke compared to control rats. Piracetam significantly reduced infarct volume by 35.77% caused by middle cerebral artery occlusion. There was no change in the pharmacokinetic parameters of piracetam in the ischemic stroke model except for brain penetration. This indicates that variables influencing brain penetration may not be limiting factors for use of piracetam in ischemic stroke.

Detection of lack of fusion using opaque additives

NASA Technical Reports Server (NTRS)

Cook, J. L.

1973-01-01

Reliable nondestructive inspection for incomplete weldment penetration and rapid oxidation of aluminum surfaces when exposed to the atmosphere are currently two major problems in welded aluminum spacecraft structure. Incomplete-penetration defects are extremely difficult to detect and can lead to catastrophic failure of the structure. The moisture absorbed by aluminum oxide on the surface can cause weldment porosity if the surface is not cleaned before welding. The approach employed in this program to solve both problems was to employ copper as a coating to prevent oxidation of the aluminum. Also, copper was used as an opaque additive in the weldment to enhance X-ray detection in the event of incomplete penetration.

Impact and Penetration Simulations for Composite Wing-like Structures

NASA Technical Reports Server (NTRS)

Knight, Norman F.

1998-01-01

The goal of this research project was to develop methodologies for the analysis of wing-like structures subjected to impact loadings. Low-speed impact causing either no damage or only minimal damage and high-speed impact causing severe laminate damage and possible penetration of the structure were to be considered during this research effort. To address this goal, an assessment of current analytical tools for impact analysis was performed. Assessment of the analytical tools for impact and penetration simulations with regard to accuracy, modeling, and damage modeling was considered as well as robustness, efficient, and usage in a wing design environment. Following a qualitative assessment, selected quantitative evaluations will be performed using the leading simulation tools. Based on this assessment, future research thrusts for impact and penetration simulation of composite wing-like structures were identified.

Modeling of Imploded Annular Plasmas.

DTIC Science & Technology

1981-05-01

field penetration into the imploding, time- varying plasma influences the thickness of the current-carrying region and the ratio of classical (core... body of the same size (a T e / r r0 ) is plotted for comparison. Using this e(nJ, Te) as a source term the net radiative loss from any plasma density...plasma with n, 1.0- 1019 cm-31 * Prad from an equivalent black body 10 19 1018 / P P Fe 1o17 L $ .01 .02 .03 .04 .06 .08 .10 .2 .3 .4 .6 .8 1.0 2 3

A perspective on high-frequency ultrasound for medical applications

NASA Astrophysics Data System (ADS)

Mamou, Jonathan; Aristizába, Orlando; Silverman, Ronald H.; Ketterling, Jeffrey A.

2010-01-01

High-frequency ultrasound (HFU, >15 MHz) is a rapidly developing field. HFU is currently used and investigated for ophthalmologic, dermatologic, intravascular, and small-animal imaging. HFU offers a non-invasive means to investigate tissue at the microscopic level with resolutions often better than 100 μm. However, fine resolution is only obtained over the limited depth-of-field (˜1 mm) of single-element spherically-focused transducers typically used for HFU applications. Another limitation is penetration depth because most biological tissues have large attenuation at high frequencies. In this study, two 5-element annular arrays with center frequencies of 17 and 34 MHz were fabricated and methods were developed to obtain images with increased penetration depth and depth-of-field. These methods were used in ophthalmologic and small-animal imaging studies. Improved blood sensitivity was obtained when a phantom mimicking a vitreous hemorrhage was imaged. Central-nervous systems of 12.5-day-old mouse embryos were imaged in utero and in three dimensions for the first time.

Penetration electric fields: A Volland Stern approach

NASA Astrophysics Data System (ADS)

Burke, William J.

2007-07-01

This paper reformulates the Volland Stern model, separating contributions from corotation and convection to predict electric field penetration of the inner magnetosphere using data from the Advanced Composition Explorer (ACE) satellite. In the absence of shielding, the model electric field is EVS=ΦPC/2LYRE, where ΦPC is the polar cap potential and 2LYRE is the width of the magnetosphere along the dawn dusk meridian. ΦPC is estimated from the interplanetary electric field (IEF) and the dynamic pressure of the solar wind (PSW); values of LY were approximated using PSW and simple force-balance considerations. ACE measurements on 16 17 April 2002 were then used to calculate EVS for comparison with the eastward electric field component (EJφ) detected by the incoherent scatter radar at Jicamarca, Peru. While the interplanetary magnetic field (IMF) was southward, the model predicted observed ratios of EVS/IEF. During intervals of northward IMF, EJφ turned westward suggesting that a northward IMF BZ system of field-aligned currents affected the electrodynamics of the dayside ionosphere on rapid time scales.

Possible effects of volcanic eruptions on stratospheric minor constituent chemistry

NASA Technical Reports Server (NTRS)

Stolarski, R. S.; Butler, D. M.

1979-01-01

Although stratosphere penetrating volcanic eruptions have been infrequent during the last half century, periods have existed in the last several hundred years when such eruptions were significantly more frequent. Several mechanisms exist for these injections to affect stratospheric minor constituent chemistry, both on the long-term average and for short-term perturbations. These mechanisms are reviewed and, because of the sensitivity of current models of stratospheric ozone to chlorine perturbations, quantitative estimates are made of chlorine injection rates. It is found that, if chlorine makes up as much as 0.5 to 1% of the gases released and if the total gases released are about the same magnitude as the fine ash, then a major stratosphere penetrating eruption could deplete the ozone column by several percent. The estimate for the Agung eruption of 1963 is just under 1% an amount not excluded by the ozone record but complicated by the peak in atmospheric nuclear explosions at about the same time.

Imaging and Quantifying Solute Transport Across Periosteum: Implications for Muscle-Bone Crosstalk

PubMed Central

Lai, Xiaohan; Price, Christopher; Lu, Xin (Lucas); Wang, Liyun

2014-01-01

Muscle and bone are known to act as a functional unit and communicate biochemically during tissue development and maintenance. Muscle-derived factors (myokines) have been found to affect bone functions in vitro. However, the transport times of myokines to penetrate into bone, a critical step required for local muscle-bone crosstalk, have not been quantified in situ or in vivo. In this study, we investigated the permeability of the periosteum, a major barrier to muscle-bone crosstalk by tracking and modeling fluorescent tracers that mimic myokines under confocal microscopy. Periosteal surface boundaries and tracer penetration within the boundaries were imaged in intact murine tibiae using reflected light and time-series xz confocal imaging, respectively. Four fluorescent tracers including sodium fluorescein (376Da) and dextrans (3kDa, 10kDa and 40kDa) were chosen because they represented a wide range of molecular weights (MW) of myokines. We found that i) murine periosteum was permeable to the three smaller tracers while the 40kDa could not penetrate beyond 40% of the outer periosteum within 8 hours, suggesting that periosteum is semi-permeable with a cut-off MW of approximately 40kDa, and ii) the characteristic penetration time through the periosteum (~60μm thick) increased with tracer MW and fit well with a relationship (((tc[sec]=−(4.43×104)−0.57×(MW[Da]−4×104)−8.65×108MW[Da]−4×104)), from which, the characteristic penetration times of various myokines were extrapolated. To achieve effective muscle-bone crosstalk, likely signaling candidates should have shorter penetration time than their bioactive time, which we assumed to be 5 times of the molecule’s half-life time in the body. Myokines such as PGE2, IGF-1, IL-15 and FGF-2 were predicted to satisfy this requirement. In summary, a novel imaging approach was developed and used to investigate the transport of myokine mimicking-tracers through the periosteum, enabling further quantitative studies of muscle-bone communication in physiologically normal and pathological conditions. PMID:24928492

Closed loop control of penetration depth during CO₂ laser lap welding processes.

PubMed

Sibillano, Teresa; Rizzi, Domenico; Mezzapesa, Francesco P; Lugarà, Pietro Mario; Konuk, Ali Riza; Aarts, Ronald; Veld, Bert Huis In 't; Ancona, Antonio

2012-01-01

In this paper we describe a novel spectroscopic closed loop control system capable of stabilizing the penetration depth during laser welding processes by controlling the laser power. Our novel approach is to analyze the optical emission from the laser generated plasma plume above the keyhole, to calculate its electron temperature as a process-monitoring signal. Laser power has been controlled by using a quantitative relationship between the penetration depth and the plasma electron temperature. The sensor is able to correlate in real time the difference between the measured electron temperature and its reference value for the requested penetration depth. Accordingly the closed loop system adjusts the power, thus maintaining the penetration depth.

Closed Loop Control of Penetration Depth during CO2 Laser Lap Welding Processes

PubMed Central

Sibillano, Teresa; Rizzi, Domenico; Mezzapesa, Francesco P.; Lugarà, Pietro Mario; Konuk, Ali Riza; Aarts, Ronald; Veld, Bert Huis in 't; Ancona, Antonio

2012-01-01

In this paper we describe a novel spectroscopic closed loop control system capable of stabilizing the penetration depth during laser welding processes by controlling the laser power. Our novel approach is to analyze the optical emission from the laser generated plasma plume above the keyhole, to calculate its electron temperature as a process-monitoring signal. Laser power has been controlled by using a quantitative relationship between the penetration depth and the plasma electron temperature. The sensor is able to correlate in real time the difference between the measured electron temperature and its reference value for the requested penetration depth. Accordingly the closed loop system adjusts the power, thus maintaining the penetration depth. PMID:23112646

ASC-AD penetration modeling FY05 status report.

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

Kistler, Bruce L.; Ostien, Jakob T.; Chiesa, Michael L.

2006-04-01

Sandia currently lacks a high fidelity method for predicting loads on and subsequent structural response of earth penetrating weapons. This project seeks to test, debug, improve and validate methodologies for modeling earth penetration. Results of this project will allow us to optimize and certify designs for the B61-11, Robust Nuclear Earth Penetrator (RNEP), PEN-X and future nuclear and conventional penetrator systems. Since this is an ASC Advanced Deployment project the primary goal of the work is to test, debug, verify and validate new Sierra (and Nevada) tools. Also, since this project is part of the V&V program within ASC, uncertaintymore » quantification (UQ), optimization using DAKOTA [1] and sensitivity analysis are an integral part of the work. This project evaluates, verifies and validates new constitutive models, penetration methodologies and Sierra/Nevada codes. In FY05 the project focused mostly on PRESTO [2] using the Spherical Cavity Expansion (SCE) [3,4] and PRESTO Lagrangian analysis with a preformed hole (Pen-X) methodologies. Modeling penetration tests using PRESTO with a pilot hole was also attempted to evaluate constitutive models. Future years work would include the Alegra/SHISM [5] and AlegrdEP (Earth Penetration) methodologies when they are ready for validation testing. Constitutive models such as Soil-and-Foam, the Sandia Geomodel [6], and the K&C Concrete model [7] were also tested and evaluated. This report is submitted to satisfy annual documentation requirements for the ASC Advanced Deployment program. This report summarizes FY05 work performed in the Penetration Mechanical Response (ASC-APPS) and Penetration Mechanics (ASC-V&V) projects. A single report is written to document the two projects because of the significant amount of technical overlap.« less

Penetration of Nonstationary Ionospheric Electric Fields into Lower Atmospheric Layers in the Global Electric Circuit Model

NASA Astrophysics Data System (ADS)

Morozov, V. N.

2018-01-01

The problem of the penetration of nonstationary ionospheric electric fields into the lower atmospheric layers is considered based on the model of the global electric circuit in the Earth's atmosphere. For the equation of the electric field potential, a solution that takes into account exponential variation in the electrical conductivity with height has been obtained. Analysis of the solution made it possible to reveal three cases of the dependence of the solution on height. The first case (the case of high frequencies) corresponds to the Coulomb approximation, when the electrical conductivity of the atmosphere can be neglected. In the case of low frequencies (when the frequency of changes in the ionosphere potential is less than the quantity reciprocal to the time of electric relaxation of the atmosphere), a quasi-stationary regime, in which the variation in the electric potential of the atmosphere is determined by the electric conduction currents, occurs. In the third case, due to the increase in the electrical conductivity of the atmosphere, two spherical regions appear: with the Coulomb approximation in the lower region and conduction currents in the upper one. For these three cases, formulas for estimating the electric field strength near the Earth's surface have been obtained.

Vulnerability of manned spacecraft to crew loss from orbital debris penetration

NASA Technical Reports Server (NTRS)

Williamsen, J. E.

1994-01-01

Orbital debris growth threatens the survival of spacecraft systems from impact-induced failures. Whereas the probability of debris impact and spacecraft penetration may currently be calculated, another parameter of great interest to safety engineers is the probability that debris penetration will cause actual spacecraft or crew loss. Quantifying the likelihood of crew loss following a penetration allows spacecraft designers to identify those design features and crew operational protocols that offer the highest improvement in crew safety for available resources. Within this study, a manned spacecraft crew survivability (MSCSurv) computer model is developed that quantifies the conditional probability of losing one or more crew members, P(sub loss/pen), following the remote likelihood of an orbital debris penetration into an eight module space station. Contributions to P(sub loss/pen) are quantified from three significant penetration-induced hazards: pressure wall rupture (explosive decompression), fragment-induced injury, and 'slow' depressurization. Sensitivity analyses are performed using alternate assumptions for hazard-generating functions, crew vulnerability thresholds, and selected spacecraft design and crew operations parameters. These results are then used to recommend modifications to the spacecraft design and expected crew operations that quantitatively increase crew safety from orbital debris impacts.

An animal study of a newly developed skin-penetrating pad and covering material for catheters to prevent exit-site infection in continuous ambulatory peritoneal dialysis.

PubMed

Aoyama, Masato; Mizuno, Toshihide; Tatsumi, Eisuke; Taenaka, Yoshiyuki; Nemoto, Yasushi; Okamoto, Yoshihiro; Takemoto, Yoshiaki; Naganuma, Toshihide; Nakatani, Tatsuya

2009-12-01

Because currently available peritoneal dialysis catheters are not sufficiently biocompatible with the skin and subcutaneous tissue at the site of penetration, exit-site infection due to pericatheter pocket formation caused by epidermal downgrowth over a long period of time has increasingly become a problem. We developed a new, biocompatible, segmented polyurethane porous material and devised a novel skin-penetrating pad, the form and material of which we optimized for application in peritoneal dialysis catheters. For the extent of tissue ingrowth into this porous material to be examined, test materials with different pore diameters were inserted into hollow silicone tubes and implanted in the subcutaneous tissue of a goat. Four weeks later, the tubes were extracted, and, after the extent of granulation tissue ingrowth was measured, histopathological evaluation was made. Our novel skin-penetrating pad has three disklike layers of the segmented polyurethane material with different pore sizes, into the center of which a polyurethane catheter is inserted. These pads were implanted in the skin of a goat and clinically observed over a 2-year period, after which they were extracted and histopathologically analyzed. In accordance with actual clinical procedures, a commercial CAPD catheter equipped with our skin-penetrating pad was left indwelling in a goat for 4 months, and the performance of the pad was evaluated after repeated periodic infusion and drainage of the dialysate in and out of the abdominal cavity. There was no inflammation of the ingrown tissue in the pores of the segmented polyurethane material as well as the surrounding tissue, which indicated favorable tissue biocompatibility. The extent of tissue ingrowth was greater as the pore size of the material was larger, and the tissue tended to be mature, mainly consisting of collagenous fibers. The skin-penetrating pad using the porous material, of which tissue ingrowth was thus optimized, tightly adhered to the goat skin throughout the 2-year experimental period without any special wound care such as cleansing or disinfection. The performance of the skin-penetrating pad was similarly favorable when attached to a commercial continuous ambulatory peritoneal dialysis catheter. The newly developed segmented polyurethane porous material had excellent tissue biocompatibility and tissue ingrowth. The skin-penetrating pad devised by using this porous material did not cause epidermal downgrowth, suggesting that it may be effective for the prevention of exit-site infection.

Extreme value statistics for two-dimensional convective penetration in a pre-main sequence star

NASA Astrophysics Data System (ADS)

Pratt, J.; Baraffe, I.; Goffrey, T.; Constantino, T.; Viallet, M.; Popov, M. V.; Walder, R.; Folini, D.

2017-08-01

Context. In the interior of stars, a convectively unstable zone typically borders a zone that is stable to convection. Convective motions can penetrate the boundary between these zones, creating a layer characterized by intermittent convective mixing, and gradual erosion of the density and temperature stratification. Aims: We examine a penetration layer formed between a central radiative zone and a large convection zone in the deep interior of a young low-mass star. Using the Multidimensional Stellar Implicit Code (MUSIC) to simulate two-dimensional compressible stellar convection in a spherical geometry over long times, we produce statistics that characterize the extent and impact of convective penetration in this layer. Methods: We apply extreme value theory to the maximal extent of convective penetration at any time. We compare statistical results from simulations which treat non-local convection, throughout a large portion of the stellar radius, with simulations designed to treat local convection in a small region surrounding the penetration layer. For each of these situations, we compare simulations of different resolution, which have different velocity magnitudes. We also compare statistical results between simulations that radiate energy at a constant rate to those that allow energy to radiate from the stellar surface according to the local surface temperature. Results: Based on the frequency and depth of penetrating convective structures, we observe two distinct layers that form between the convection zone and the stable radiative zone. We show that the probability density function of the maximal depth of convective penetration at any time corresponds closely in space with the radial position where internal waves are excited. We find that the maximal penetration depth can be modeled by a Weibull distribution with a small shape parameter. Using these results, and building on established scalings for diffusion enhanced by large-scale convective motions, we propose a new form for the diffusion coefficient that may be used for one-dimensional stellar evolution calculations in the large Péclet number regime. These results should contribute to the 321D link.

USDC based rapid penetrator of packed soil

NASA Technical Reports Server (NTRS)

Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Badescu, Mircea

2006-01-01

Environment protection requires more testing and analysis tools. To detect buried chemical containers or other objects embedded in soil and avoid possible damages of them, a penetrator of packed soil operated using low pushing force was developed. The design was based on a novel driving mechanism of the ultrasonic/sonic driller/corer (USDC) device developed in the NDEAA lab at JPL [Bar-Cohen et al 2001, Bao et al 2003]. In the penetrator, a small free-flying mass is energized by a piezoelectric transducer and impacts a rod probe on its shoulder at frequencies of hundreds times per second. The impacts help the probe to penetrate the packed soil rapidly. A great reduction of the needed pushing force for penetration was achieved. The details of the design of the prototype penetrator and the results of performance tests are presented.

Imaging tropical peatlands in Indonesia using ground-penetrating radar (GPR) and electrical resistivity imaging (ERI): implications for carbon stock estimates and peat soil characterization

Treesearch

X. Comas; N. Terry; M. Warren; R. Kolka; A. Kristiyono; N. Sudiana; D. Nurjaman; T. Darusman

2015-01-01

Current estimates of carbon (C) storage in peatland systems worldwide indicate that tropical peatlands comprise about 15% of the global peat carbon pool. Such estimates are uncertain due to data gaps regarding organic peat soil thickness, volume and C content. We combined a set of indirect geophysical methods (ground-penetrating radar, GPR, and electrical resistivity...

Current management of penetrating torso trauma: nontherapeutic is not good enough anymore

PubMed Central

Ball, Chad G.

2014-01-01

A highly organized approach to the evaluation and treatment of penetrating torso injuries based on regional anatomy provides rapid diagnostic and therapeutic consistency. It also minimizes delays in diagnosis, missed injuries and nontherapeutic laparotomies. This review discusses an optimal sequence of structured rapid assessments that allow the clinician to rapidly proceed to gold standard therapies with a minimal risk of associated morbidity. PMID:24666458

Backstabbing swordfish: a rare cause of traumatic hemiparesis.

PubMed

Sriram, Prabu Rau; Tsin Jien, Timothy Cheng; Sellamuthu, Pulivendhan

2017-08-01

Swordfish attacks on humans are uncommon, with only a few case reports available in the current literature. The authors report the first known case of a penetrating spinal injury from a swordfish, in which the patient presented with a small stab wound and hemiparesis. The presentation of a fisherman with hemiparesis and a harmless-looking stab wound must alert clinicians to the possibility of penetrating swordfish injuries to the spine.

The Use of Inhibitors of Mechanosensitive Ion Channels as Local Inhibitors of Peripheral Pain

DTIC Science & Technology

2015-01-01

in the medical care of soldiers and veterans, whether in acute or chronic injury. Current analgesics, while effective, suffer from a potential for... potential  of ‐60 mV. Panel B is a dose‐response  curve of mechanical sensitivity with increasing depths of penetration producing more current.  Panel C is...emphasizes that the channels couple mechanical stress to membrane  potential  in time dependent ways. Panel D is an IV  curve derived from the cell‐attached

Electrical Detection of Cellular Penetration during Microinjection with Carbon Nanopipettes

PubMed Central

Anderson, Sean E.; Bau, Haim H.

2014-01-01

The carbon nanopipette (CNP) is comprised of a pulled-glass pipette terminating with a nanoscale (tens to hundreds of nm) diameter carbon pipe. The entire inner glass surface of the CNP is coated with a carbon film, providing an electrically conductive path from the carbon tip to the distal, macroscopic end of the pipette. The CNP can double as a nanoelectrode, enabling electrical measurements through its carbon lining, and as a nanoinjector, facilitating reagent injection through its hollow bore. With the aid of a lock-in amplifier, we measured, in real time and with millisecond resolution, variations in impedance as the CNP penetrated into the cytoplasm and nucleus of adherent human osteosarcoma (U20S) cells. The capacitance change associated with nucleus penetration was, on average, 1.5 times greater than the one associated with cell membrane penetration. The experimental data was compared and favorably agreed with theoretical predictions based on a simple electrical network model. As a proof of concept, the cytoplasm and nucleus were transfected with fluorescent tRNA, enabling real-time monitoring of tRNA trafficking across the nuclear membrane. The CNP provides a robust and reliable means to detect cell and nucleus penetration, and trigger injection, thereby enabling the automation of cell injection. PMID:24859799

Electrical detection of cellular penetration during microinjection with carbon nanopipettes.

PubMed

Anderson, Sean E; Bau, Haim H

2014-06-20

The carbon nanopipette (CNP) is comprised of a pulled-glass pipette terminating with a nanoscale (tens to hundreds of nm) diameter carbon pipe. The entire inner glass surface of the CNP is coated with a carbon film, providing an electrically conductive path from the carbon tip to the distal, macroscopic end of the pipette. The CNP can double as a nanoelectrode, enabling electrical measurements through its carbon lining, and as a nanoinjector, facilitating reagent injection through its hollow bore. With the aid of a lock-in amplifier, we measured, in real time and with millisecond resolution, variations in impedance and interfacial capacitance as the CNP penetrated into the cytoplasm and nucleus of adherent human osteosarcoma (U20S) cells during microinjection. The capacitance change associated with nucleus penetration was, on average, 1.5 times greater than the one associated with cell membrane penetration. The experimental data was compared and favorably agreed with theoretical predictions based on a simple electrical network model. As a proof of concept, the cytoplasm and nucleus were transfected with fluorescent tRNA, enabling real-time monitoring of tRNA trafficking across the nuclear membrane. The CNP provides a robust and reliable means to detect cell and nucleus penetration, and trigger injection, thereby enabling the automation of cell injection.

Electrical detection of cellular penetration during microinjection with carbon nanopipettes

NASA Astrophysics Data System (ADS)

Anderson, Sean E.; Bau, Haim H.

2014-06-01

The carbon nanopipette (CNP) is comprised of a pulled-glass pipette terminating with a nanoscale (tens to hundreds of nm) diameter carbon pipe. The entire inner glass surface of the CNP is coated with a carbon film, providing an electrically conductive path from the carbon tip to the distal, macroscopic end of the pipette. The CNP can double as a nanoelectrode, enabling electrical measurements through its carbon lining, and as a nanoinjector, facilitating reagent injection through its hollow bore. With the aid of a lock-in amplifier, we measured, in real time and with millisecond resolution, variations in impedance and interfacial capacitance as the CNP penetrated into the cytoplasm and nucleus of adherent human osteosarcoma (U20S) cells during microinjection. The capacitance change associated with nucleus penetration was, on average, 1.5 times greater than the one associated with cell membrane penetration. The experimental data was compared and favorably agreed with theoretical predictions based on a simple electrical network model. As a proof of concept, the cytoplasm and nucleus were transfected with fluorescent tRNA, enabling real-time monitoring of tRNA trafficking across the nuclear membrane. The CNP provides a robust and reliable means to detect cell and nucleus penetration, and trigger injection, thereby enabling the automation of cell injection.

Superconducting levitating bearing

NASA Technical Reports Server (NTRS)

Moon, Francis C. (Inventor)

1996-01-01

A superconducting bearing assembly includes a coil field source that may be superconducting and a superconducting structure. The coil field source assembly and superconducting structure are positioned so as to enable relative rotary movement therebetween. The structure and coil field source are brought to a supercooled temperature before a power supply induces a current in the coil field source. A Meissner-like effect is thereby obtained and little or no penetration of the field lines is seen in the superconducting structure. Also, the field that can be obtained from the superconducting coil is 2-8 times higher than that of permanent magnets. Since the magnetic pressure is proportioned to the square of the field, magnetic pressures from 4 to 64 times higher are achieved.

Using Conventional Hydropower to Help Alleviate Variable Resource Grid Integration Challenges in the Western U.S

NASA Astrophysics Data System (ADS)

Veselka, T. D.; Poch, L.

2011-12-01

Integrating high penetration levels of wind and solar energy resources into the power grid is a formidable challenge in virtually all interconnected systems due to the fact that supply and demand must remain in balance at all times. Since large scale electricity storage is currently not economically viable, generation must exactly match electricity demand plus energy losses in the system as time unfolds. Therefore, as generation from variable resources such as wind and solar fluctuate, production from generating resources that are easier to control and dispatch need to compensate for these fluctuations while at the same time respond to both instantaneous change in load and follow daily load profiles. The grid in the Western U.S. is not exempt to grid integration challenges associated with variable resources. However, one advantage that the power system in the Western U.S. has over many other regional power systems is that its footprint contains an abundance of hydropower resources. Hydropower plants, especially those that have reservoir water storage, can physically change electricity production levels very quickly both via a dispatcher and through automatic generation control. Since hydropower response time is typically much faster than other dispatchable resources such as steam or gas turbines, it is well suited to alleviate variable resource grid integration issues. However, despite an abundance of hydropower resources and the current low penetration of variable resources in the Western U.S., problems have already surfaced. This spring in the Pacific Northwest, wetter than normal hydropower conditions in combination with transmission constraints resulted in controversial wind resource shedding. This action was taken since water spilling would have increased dissolved oxygen levels downstream of dams thereby significantly degrading fish habitats. The extent to which hydropower resources will be able to contribute toward a stable and reliable Western grid is currently being studied. Typically these studies consider the inherent flexibility of hydropower technologies, but tend to fall short on details regarding grid operations, institutional arrangements, and hydropower environmental regulations. This presentation will focus on an analysis that Argonne National Laboratory is conducting in collaboration with the Western Area Power Administration (Western). The analysis evaluates the extent to which Western's hydropower resources may help with grid integration challenges via a proposed Energy Imbalance Market. This market encompasses most of the Western Electricity Coordinating Council footprint. It changes grid operations such that the real-time dispatch would be, in part, based on a 5-minute electricity market. The analysis includes many factors such as site-specific environmental considerations at each of its hydropower facilities, long-term firm purchase agreements, and hydropower operating objectives and goals. Results of the analysis indicate that site-specific details significantly affect the ability of hydropower plant to respond to grid needs in a future which will have a high penetration of variable resources.

Mixed-Penetrant Sorption in Ultrathin Films of Polymer of Intrinsic Microporosity PIM-1.

PubMed

Ogieglo, Wojciech; Furchner, Andreas; Ghanem, Bader; Ma, Xiaohua; Pinnau, Ingo; Wessling, Matthias

2017-11-02

Mixed-penetrant sorption into ultrathin films of a superglassy polymer of intrinsic microporosity (PIM-1) was studied for the first time by using interference-enhanced in situ spectroscopic ellipsometry. PIM-1 swelling and the concurrent changes in its refractive index were determined in ultrathin (12-14 nm) films exposed to pure and mixed penetrants. The penetrants included water, n-hexane, and ethanol and were chosen on the basis of their significantly different penetrant-penetrant and penetrant-polymer affinities. This allowed studying microporous polymer responses at diverse ternary compositions and revealed effects such as competition for the sorption sites (for water/n-hexane or ethanol/n-hexane) or enhancement in sorption of typically weakly sorbing water in the presence of more highly sorbing ethanol. The results reveal details of the mutual sorption effects which often complicate comprehension of glassy polymers' behavior in applications such as high-performance membranes, adsorbents, or catalysts. Mixed-penetrant effects are typically very challenging to study directly, and their understanding is necessary owing to a broadly recognized inadequacy of simple extrapolations from measurements in a pure component environment.

Imaging and quantifying solute transport across periosteum: implications for muscle-bone crosstalk.

PubMed

Lai, Xiaohan; Price, Christopher; Lu, Xin Lucas; Wang, Liyun

2014-09-01

Muscle and bone are known to act as a functional unit and communicate biochemically during tissue development and maintenance. Muscle-derived factors (myokines) have been found to affect bone functions in vitro. However, the transport times of myokines to penetrate into bone, a critical step required for local muscle-bone crosstalk, have not been quantified in situ or in vivo. In this study, we investigated the permeability of the periosteum, a major barrier to muscle-bone crosstalk by tracking and modeling fluorescent tracers that mimic myokines under confocal microscopy. Periosteal surface boundaries and tracer penetration within the boundaries were imaged in intact murine tibiae using reflected light and time-series xz confocal imaging, respectively. Four fluorescent tracers including sodium fluorescein (376Da) and dextrans (3kDa, 10kDa and 40kDa) were chosen because they represented a wide range of molecular weights (MW) of myokines. We found that i) murine periosteum was permeable to the three smaller tracers while the 40kDa could not penetrate beyond 40% of the outer periosteum within 8h, suggesting that periosteum is semi-permeable with a cut-off MW of approximately 40kDa, and ii) the characteristic penetration time through the periosteum (~60μm thick) increased with tracer MW and fit well with a relationship tcs=-4.43×10(4)-0.57×MWDa-4×10(4)-8.65×10(8)MWDa-4×10(4), from which, the characteristic penetration times of various myokines were extrapolated. To achieve effective muscle-bone crosstalk, likely signaling candidates should have shorter penetration time than their bioactive time, which we assumed to be 5 times of the molecule's half-lifetime in the body. Myokines such as PGE2, IGF-1, IL-15 and FGF-2 were predicted to satisfy this requirement. In summary, a novel imaging approach was developed and used to investigate the transport of myokine mimicking-tracers through the periosteum, enabling further quantitative studies of muscle-bone communication in physiologically normal and pathological conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

Study on Microstructure and Mechanical Properties of 304 Stainless Steel Joints by Tig-Mig Hybrid Welding

NASA Astrophysics Data System (ADS)

Ogundimu, Emmanuel O.; Akinlabi, Esther T.; Erinosho, Mutiu F.

Stainless steel is a family of Fe-based alloys having excellent resistance to corrosion and as such has been used imperatively for kitchen utensils, transportation, building constructions and much more. This paper presents the work conducted on the material characterizations of a tungsten inert gas (TIG)-metal inert gas (MIG) hybrid welded joint of type 304 austenitic stainless steel. The welding processes were conducted in three phases. The phases of welding employed are MIG welding using a current of 170A, TIG welding using a current of 190A, and a hybrid TIG-MIG welding with currents of 190/170A, respectively. The MIG, TIG, and hybrid TIG-MIG weldments were characterized with incomplete penetration, full penetration and excess penetration of weld. Intergranular austenite was created toward transition and heat affected zones. The thickness of the delta ferrite (δ-Fe) formed in the microstructures of the TIG weld is more than the thickness emerged in the microstructures of MIG and hybrid TIG-MIG welds. A TIG-MIG hybrid weld of specimen welded at the currents of 190/170A has the highest ultimate tensile strength value and percentage elongation of 397.72MPa and 35.7%. The TIG-MIG hybrid welding can be recommended for high-tech industrial applications such as nuclear, aircraft, food processing, and automobile industry.

Physics based Prediction of Unexploded Ordnance Penetration in Granular Materials

DTIC Science & Technology

2017-05-01

0.08 0.10 0.12 0.14 0.16 0.18 D is pl ac em en t ( m m ) Time (s) Simulation Centrifuge test 91 cylindrical DSE assembly, and the shape of the stress...0.18 D is pl ac em en t ( m m ) Time (s) Simulation Centrifuge test 96 a) b) c) d) Figure 5.21 Projectile penetration simulation vertical...penetration (Fig. 5.25c and Fig. 5.26c). -4000 -3500 -3000 -2500 -2000 -1500 -1000 -500 0 0.00 0.02 0.04 0.06 0.08 0.10 D is pl ac em en t ( m m

Ballistics ordnance gelatine - How different concentrations, temperatures and curing times affect calibration results.

PubMed

Maiden, Nicholas R; Fisk, Wesley; Wachsberger, Christian; Byard, Roger W

2015-08-01

A study was undertaken to determine whether different concentrations of ordnance gelatine, water types, temperatures and curing times would have an effect on projectile penetration of a gelatine tissue surrogate. Both Federal Bureau of Investigation (FBI) and North Atlantic Treaty Organization (NATO) specified gelatines were compared against the FBI calibration standard. 10% w/w and 20% w/w concentrations of gelatine with Bloom numbers of 250 and 285 were prepared and cured at variable temperatures (3-20°C) for 21 hours-3 weeks. Each block was shot on four occasions on the same range using steel calibre 4.5 mm BBs fired from a Daisy(®) air rifle at the required standard velocity of 180 ± 4.5 m/s, to ascertain the mean penetration depth. The results showed no significant difference in mean penetration depth using the three different water types (p > 0.05). Temperature changes and curing times did affect penetration depth. At 10°C, mean penetration depth with 20% gelatine 285 Bloom for the two water types tested was 49.7 ± 1.5 mm after 21 h curing time, whereas the same formulation at 20°C using two different water types was 79.1 ± 2.1 mm after 100 h curing time (p < 0.001). Neither of the NATO 20% concentrations of gelatine at 10°C or a 20% concentration of 285 Bloom gelatine at 10°C met the same calibration standard as the FBI recommended 10% formulation at 4°C. A 20% concentration of 285 Bloom at 20°C met the same calibration/penetration criteria as a 10% concentration of 250 Bloom at 4 °C after 100 h of curing, therefore matching the FBI calibration standard for a soft tissue simulant for wound ballistics research. These results demonstrate significant variability in simulant properties. Failure to standardise ballistic simulants may invalidate experimental results. Copyright © 2015. Published by Elsevier Ltd.

Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries.

PubMed

Zhang, Hairong; Salo, Daniel; Kim, David M; Komarov, Sergey; Tai, Yuan-Chuan; Berezin, Mikhail Y

2016-12-01

Measurement of photon penetration in biological tissues is a central theme in optical imaging. A great number of endogenous tissue factors such as absorption, scattering, and anisotropy affect the path of photons in tissue, making it difficult to predict the penetration depth at different wavelengths. Traditional studies evaluating photon penetration at different wavelengths are focused on tissue spectroscopy that does not take into account the heterogeneity within the sample. This is especially critical in shortwave infrared where the individual vibration-based absorption properties of the tissue molecules are affected by nearby tissue components. We have explored the depth penetration in biological tissues from 900 to 1650 nm using Monte–Carlo simulation and a hyperspectral imaging system with Michelson spatial contrast as a metric of light penetration. Chromatic aberration-free hyperspectral images in transmission and reflection geometries were collected with a spectral resolution of 5.27 nm and a total acquisition time of 3 min. Relatively short recording time minimized artifacts from sample drying. Results from both transmission and reflection geometries consistently revealed that the highest spatial contrast in the wavelength range for deep tissue lies within 1300 to 1375 nm; however, in heavily pigmented tissue such as the liver, the range 1550 to 1600 nm is also prominent.

Penetration boundary of solar cosmic rays into the earth's magnetosphere during magnetically quiet times

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

Biryukov, A.S.; Ivanova, T.A.; Kovrygina, L.M.

1984-05-01

Data is used from the satellites Interkosmos-17 and Kosmos-900 to determine penetration boundaries at high latitudes in the earth's magnetosphere. Considered are the results of observations of the penetration boundary of solar cosmic ray (SCR) protons and electrons during an SCR increase on November 22-25, 1977. The position of the SCR penetration boundary during a single increase at practically all values of MLT in quiet conditions is examined. Magnetospheric structure is determined in the region of closed drift shells where the magnetic field is asymmetric. The authors can estimate how the solar wind pressure affects the magnetosphere by using datamore » on the penetration boundaries of solar protons obtained during quiet geomagnetic conditions.« less

Comparative Assessment of Tactics to Improve Primary Frequency Response Without Curtailing Solar Output in High Photovoltaic Interconnection Grids

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

Tan, Jin; Zhang, Yingchen; You, Shutang

Power grid primary frequency response will be significantly impaired by Photovoltaic (PV) penetration increase because of the decrease in inertia and governor response. PV inertia and governor emulation requires reserving PV output and leads to solar energy waste. This paper exploits current grid resources and explores energy storage for primary frequency response under high PV penetration at the interconnection level. Based on the actual models of the U.S. Eastern Interconnection grid and the Texas grid, effects of multiple factors associated with primary frequency response, including the governor ratio, governor deadband, droop rate, fast load response. are assessed under high PVmore » penetration scenarios. In addition, performance of batteries and supercapacitors using different control strategies is studied in the two interconnections. The paper quantifies the potential of various resources to improve interconnection-level primary frequency response under high PV penetration without curtailing solar output.« less

Leveraging paraprofessionals and family strengths to improve coverage and penetration of nutrition and early child development services.

PubMed

Tomlinson, Mark; Rahman, Atif; Sanders, David; Maselko, Joanna; Rotheram-Borus, Mary Jane

2014-01-01

Children need to be protected in intergenerational networks, with parents who have positive mood, resources to feed their children, and skills to promote early childhood development (ECD). Globally, more than 200 million children are raised annually without these resources. This article reviews the potential contributions of increasing coverage and penetration of services for these children, challenges to achieving penetration of services in high-risk families, opportunities created by bundling multiple services within one provider, potential leveraging of paraprofessionals to deliver care, and mobilizing communities to support children in households at high risk for negative outcomes. We end with a number of suggestions for how to ensure the equitable scale-up of integrated ECD and nutrition services that take into account current global priorities, as well as coverage and penetration of services. © 2013 New York Academy of Sciences.

Shape-Dependent Skin Penetration of Silver Nanoparticles: Does It Really Matter?

PubMed Central

Tak, Yu Kyung; Pal, Sukdeb; Naoghare, Pravin K.; Rangasamy, Sabarinathan; Song, Joon Myong

2015-01-01

Advancements in nano-structured materials have facilitated several applications of nanoparticles (NPs). Skin penetration of NPs is a crucial factor for designing suitable topical antibacterial agents with low systemic toxicity. Available reports focus on size-dependent skin penetration of NPs, mainly through follicular pathways. Herein, for the first time, we demonstrate a proof-of-concept study that entails variations in skin permeability and diffusion coefficients, penetration rates and depth-of-penetration of differently shaped silver NPs (AgNPs) via intercellular pathways using both in vitro and in vivo models. The antimicrobial activity of AgNPs is known. Different shapes of AgNPs may exhibit diverse antimicrobial activities and skin penetration capabilities depending upon their active metallic facets. Consideration of the shape dependency of AgNPs in antimicrobial formulations could help developing an ideal topical agent with the highest efficacy and low systemic toxicity. PMID:26584777

Ground-penetrating radar--A tool for mapping reservoirs and lakes

USGS Publications Warehouse

Truman, C.C.; Asmussen, L.E.; Allison, H.D.

1991-01-01

Ground-penetrating radar was evaluated as a tool for mapping reservoir and lake bottoms and providing stage-storage information. An impulse radar was used on a 1.4-ha (3.5-acre) reservoir with 31 transects located 6.1 m (20 feet) apart. Depth of water and lateral extent of the lake bottom were accurately measured by ground-penetrating radar. A linear (positive) relationship existed between measured water depth and ground-penetrating radar-determined water depth (R2=0.989). Ground-penetrating radar data were used to create a contour map of the lake bottom. Relationships between water (contour) elevation and water surface area and volume were established. Ground-penetrating radar proved to be a useful tool for mapping lakes, detecting lake bottom variations, locating old stream channels, and determining water depths. The technology provides accurate, continuous profile data in a relatively short time compared to traditional surveying and depth-sounding techniques.

Advanced Metering Infrastructure based on Smart Meters

NASA Astrophysics Data System (ADS)

Suzuki, Hiroshi

By specifically designating penetrations rates of advanced meters and communication technologies, devices and systems, this paper introduces that the penetration of advanced metering is important for the future development of electric power system infrastructure. It examines the state of the technology and the economical benefits of advanced metering. One result of the survey is that advanced metering currently has a penetration of about six percent of total installed electric meters in the United States. Applications to the infrastructure differ by type of organization. Being integrated with emerging communication technologies, smart meters enable several kinds of features such as, not only automatic meter reading but also distribution management control, outage management, remote switching, etc.

Developing High PV Penetration Cases for Frequency Response Study of U.S. Western Interconnection: Preprint

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

Tan, Jin; Zhang, Yingchen; Veda, Santosh

Recent large penetrations of solar photovoltaic (PV) generation and the inertial characteristics of inverter-based generation technologies have caught the attention of those in the electric power industry in the United States. This paper presents a systematic approach to developing test cases of high penetrations of PV for the Western Interconnection. First, to examine the accuracy of the base case model, the Western Electricity Coordinating Council (WECC) model is validated by using measurement data from synchronized phasor measurement units. Based on the 2022 Light Spring case, we developed four high PV penetration cases for the WECC system that are of interestmore » to the industry: 5% PV+15 % wind, 25% PV+15% wind, 45% PV+15% wind, 65% PV+15% wind). Additionally, a method to project PV is proposed that is based on collected, realistic PV distribution information, including the current and future PV power plant locations and penetrations in the WECC system. Both the utility-scale PV plant and residential rooftop PV are included in this study.« less

Developing High PV Penetration Cases for Frequency Response Study of U.S. Western Interconnection

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

Tan, Jin; Zhang, Yingchen; Veda, Santosh

Recent large penetrations of solar photovoltaic (PV) generation and the inertial characteristics of inverter-based generation technologies have caught the attention of those in the electric power industry in the United States. This paper presents a systematic approach to developing test cases of high penetrations of PV for the Western Interconnection. First, to examine the accuracy of the base case model, the Western Electricity Coordinating Council (WECC) model is validated by using measurement data from synchronized phasor measurement units. Based on the 2022 Light Spring case, we developed four high PV penetration cases for the WECC system that are of interestmore » to the industry: 5% PV+15 % wind, 25% PV+15% wind, 45% PV+15% wind, 65% PV+15% wind). Additionally, a method to project PV is proposed that is based on collected, realistic PV distribution information, including the current and future PV power plant locations and penetrations in the WECC system. Both the utility-scale PV plant and residential rooftop PV are included in this study.« less

Developing High PV Penetration Cases for Frequency Response Study of U.S. Western Interconnection: Preprint

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

Tan, Jin; Zhang, Yingchen; Veda, Santosh

2017-04-11

Recent large penetrations of solar photovoltaic (PV) generation and the inertial characteristics of inverter-based generation technologies have caught the attention of those in the electric power industry in the United States. This paper presents a systematic approach to developing test cases of high penetrations of PV for the Western Interconnection. First, to examine the accuracy of the base case model, the Western Electricity Coordinating Council (WECC) model is validated by using measurement data from synchronized phasor measurement units. Based on the 2022 Light Spring case, we developed four high PV penetration cases for the WECC system that are of interestmore » to the industry: 5% PV+15 % wind, 25% PV+15% wind, 45% PV+15% wind, 65% PV+15% wind). Additionally, a method to project PV is proposed that is based on collected, realistic PV distribution information, including the current and future PV power plant locations and penetrations in the WECC system. Both the utility-scale PV plant and residential rooftop PV are included in this study.« less

Preliminary results of sequential monitoring of simulated clandestine graves in Colombia, South America, using ground penetrating radar and botany.

PubMed

Molina, Carlos Martin; Pringle, Jamie K; Saumett, Miguel; Hernández, Orlando

2015-03-01

In most Latin American countries there are significant numbers of missing people and forced disappearances, 68,000 alone currently in Colombia. Successful detection of shallow buried human remains by forensic search teams is difficult in varying terrain and climates. This research has created three simulated clandestine burial styles at two different depths commonly encountered in Latin America to gain knowledge of optimum forensic geophysics detection techniques. Repeated monitoring of the graves post-burial was undertaken by ground penetrating radar. Radar survey 2D profile results show reasonable detection of ½ clothed pig cadavers up to 19 weeks of burial, with decreasing confidence after this time. Simulated burials using skeletonized human remains were not able to be imaged after 19 weeks of burial, with beheaded and burnt human remains not being able to be detected throughout the survey period. Horizontal radar time slices showed good early results up to 19 weeks of burial as more area was covered and bi-directional surveys were collected, but these decreased in amplitude over time. Deeper burials were all harder to image than shallower ones. Analysis of excavated soil found soil moisture content almost double compared to those reported from temperate climate studies. Vegetation variations over the simulated graves were also noted which would provide promising indicators for grave detection. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Investigation of the mechanism for penetration of low density lipoprotein into the arterial wall

NASA Astrophysics Data System (ADS)

Glukhova, O. E.; Zyktin, A. A.; Slepchenkov, M. M.

2018-02-01

Currently, the pathology of the cardiovascular system is an extremely urgent problem of fundamental and clinical medicine. These diseases are caused, mainly, by atherosclerotic changes in the wall of blood vessels. The predominant role in the development of atherosclerosis is attributed to the penetration of various kinds of lipoproteins into the arterial intima. In this paper, we in silico investigated the dynamics of the penetration of low density lipoprotein (LDL) through the intercellular gap using molecular modeling methods. The simulation was carried out in the GROMACS software package using a coarse-grained MARTINI model. During investigation we carried out the LDL self-assembly for the first time. The coarse-grained model of LDL was collected from the following molecules: POPC (phosphatidylcholine) - 630 molecules, LPC (lysophosphatidylcholine) - 80 molecules CHOL (cholesterol) - 600 molecules CHYO (cholesteryl oleate) - 1600 molecules TOG (glycerol trioleate) 180 Molecules. The coarse-grained model of the intercellular endothelial gap was based on a model of lipid bilayer consisting of DPPC phospholipids and cholesterol in a percentage ratio of 70% and 30%, respectively. Based on the obtained results, we can predict the mechanism of LDL diffusion. Lipoproteins can be deformed so as to pass through narrow gaps. Our investigations open the way for the research of the behavior dynamics of LDL moving with the blood flow rate when interacting with the intercellular gaps of the endothelial layer of the vessel inner wall.

Effect of Pulse Parameters on Weld Quality in Pulsed Gas Metal Arc Welding: A Review

NASA Astrophysics Data System (ADS)

Pal, Kamal; Pal, Surjya K.

2011-08-01

The weld quality comprises bead geometry and its microstructure, which influence the mechanical properties of the weld. The coarse-grained weld microstructure, higher heat-affected zone, and lower penetration together with higher reinforcement reduce the weld service life in continuous mode gas metal arc welding (GMAW). Pulsed GMAW (P-GMAW) is an alternative method providing a better way for overcoming these afore mentioned problems. It uses a higher peak current to allow one molten droplet per pulse, and a lower background current to maintain the arc stability. Current pulsing refines the grains in weld fusion zone with increasing depth of penetration due to arc oscillations. Optimum weld joint characteristics can be achieved by controlling the pulse parameters. The process is versatile and easily automated. This brief review illustrates the effect of pulse parameters on weld quality.

Heat penetration attributes of milkfish (Chanos chanos) thermal processed in flexible pouches: a comparative study between steam application and water immersion.

PubMed

Adepoju, Mary A; Omitoyin, Bamidele O; Mohan, Chitradurga O; Zynudheen, Aliyam A

2017-05-01

The difference in the heating penetration characteristics of product processed in retort by steam-air application and water immersion was studied. Fresh milkfish ( Chanos chanos ) packed in dry pack and in oil medium, both in flexible pouches, was thermal processed to minimum F 0 value of 7.77 at 121.1°C. Heat penetration values were recorded for each minute of processing with the aid Ellab (TM 9608, Denmark) temperature recorder. Retort come up time to achieve 121.1°C was observed to be less in steam-air which invariably led to a lower Ball's process time (B) and the total process time (T) observed in steam-air as compared to water immersion. Obtained data were plotted on a semi-logarithmic paper with temperature deficit on x -axis against time on the y -axis.

Soil crusts on Mars

NASA Technical Reports Server (NTRS)

Moore, H. J.

1991-01-01

Three distinct soillike materials sampled by the Viking landers (VL) on Mars are (in order of increasing strength): (1) drift; (2) crusty to cloddy; and (3) blocky. Relative strengths of these materials are manifested by footpad penetrations during landing (VL 1), depths of deep holes, motor currents during sampling, sampler backhoe penetrations, comminutor motor currents, impact pits, trench tailings, and successful acquisitions of the coarse fraction (only blocky material). Cementation by S Cl compounds probably contributes to the relative strengths. This is shown where the weight pct. of SO3 + Cl of each material is plotted against their relative strengths. A similar result is obtained using SO3 alone, but not with Cl which is deficient in VL 2 samples.

Effect of egg washing and correlation between cuticle and egg penetration by various Salmonella strains.

PubMed

Gole, Vaibhav C; Roberts, Juliet R; Sexton, Margaret; May, Damian; Kiermeier, Andreas; Chousalkar, Kapil K

2014-07-16

In Australia, Europe and the United States, eggs and egg products are frequently associated with Salmonella food poisoning outbreaks. Many of the egg-associated Salmonella outbreaks have been due to the products such as mayonnaise, ice-cream and cold desserts which are eaten without cooking following the addition of raw egg. The ability of four Salmonella isolates (one each of S. Singapore, S. Adelaide, S. Worthington and S. Livingstone) to penetrate washed and unwashed eggs using whole egg and agar egg penetration methods was investigated in the current study. The results of the agar penetration experiment indicated that all the isolates used in the present study have the capacity to penetrate the eggshell. Eggshell penetration by the S. Worthington isolate was higher but not significant (p=0.06) in washed eggs compared to unwashed eggs. However, for all other isolates (S. Singapore, S. Adelaide and S. Livingstone), there was no significant difference in penetration of washed and unwashed eggs. Statistical analysis indicated that cuticle score was a significant linear predictor of Salmonella eggshell penetration. Whole egg penetration results showed that all of the Salmonella isolates used in the present study were capable of surviving on the eggshell surface after 21days of incubation (at 20°C) following a high dose of inoculation (10(5)CFU/mL). The combined data of all isolates demonstrated that, the survival rate of Salmonella on eggshells (inoculated with 10(5)CFU/mL) was significantly higher (p=0.002) at 20°C as compared to 37°C. S. Singapore, S. Worthington, and S. Livingstone were not detected in egg internal contents whereas S. Adelaide was detected in one egg's internal contents. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

New Media in Student Recruiting: Bright Promise, Current Realities.

ERIC Educational Resources Information Center

Stoner, Michael

1996-01-01

Explores current options for using the World Wide Web and interactive media for undergraduate recruiting. Discusses some technological issues concerning market penetration of technologies, and explores the issue of return on investment. Currently available data do not support spending a lot of money on Web pages, although CD-ROM or floppy disks…

Current-induced depairing in the Bi2Te3/FeTe interfacial superconductor

NASA Astrophysics Data System (ADS)

Kunchur, M. N.; Dean, C. L.; Moghadam, N. Shayesteh; Knight, J. M.; He, Q. L.; Liu, H.; Wang, J.; Lortz, R.; Sou, I. K.; Gurevich, A.

2015-09-01

We investigated current induced depairing in the Bi2Te3 /FeTe topological insulator-chalcogenide interface superconductor. The measured depairing current density provides information on the magnetic penetration depth and superfluid density, which in turn shed light on the nature of the normal state that underlies the interfacial superconductivity.

Statistical variability study of random dopant fluctuation on gate-all-around inversion-mode silicon nanowire field-effect transistors

NASA Astrophysics Data System (ADS)

Yoon, Jun-Sik; Rim, Taiuk; Kim, Jungsik; Kim, Kihyun; Baek, Chang-Ki; Jeong, Yoon-Ha

2015-03-01

Random dopant fluctuation effects of gate-all-around inversion-mode silicon nanowire field-effect transistors (FETs) with different diameters and extension lengths are investigated. The nanowire FETs with smaller diameter and longer extension length reduce average values and variations of subthreshold swing and drain-induced barrier lowering, thus improving short channel immunity. Relative variations of the drain currents increase as the diameter decreases because of decreased current drivability from narrower channel cross-sections. Absolute variations of the drain currents decrease critically as the extension length increases due to decreasing the number of arsenic dopants penetrating into the channel region. To understand variability origins of the drain currents, variations of source/drain series resistance and low-field mobility are investigated. All these two parameters affect the variations of the drain currents concurrently. The nanowire FETs having extension lengths sufficient to prevent dopant penetration into the channel regions and maintaining relatively large cross-sections are suggested to achieve suitable short channel immunity and small variations of the drain currents.

Impacts of Variable Renewable Energy on Bulk Power System Assets, Pricing, and Costs

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

Wiser, Ryan H.; Mills, Andrew; Seel, Joachim

We synthesize available literature, data, and analysis on the degree to which growth in variable renewable energy (VRE) has impacted to date or might in the future impact bulk power system assets, pricing, and costs. We do not analyze impacts on specific power plants, instead focusing on national and regional system-level trends. The issues addressed are highly context dependent—affected by the underlying generation mix of the system, the amount of wind and solar penetration, and the design and structure of the bulk power system in each region. Moreover, analyzing the impacts of VRE on the bulk power system is amore » complex area of research and there is much more to be done to increase understanding of how VRE impacts the dynamics of current and future electricity markets. While more analysis is warranted, including additional location-specific assessments, several high-level findings emerge from this synthesis: -VRE Is Already Impacting the Bulk Power Market -VRE Impacts on Average Wholesale Prices Have Been Modest -VRE Impacts on Power Plant Retirements Have So Far Been Limited -VRE Impacts on the Bulk Power Market will Grow with Penetration -The ’System Value’ of VRE will Decline with Penetration -Power System Flexibility Can Reduce the Rate of VRE Value Decline All generation types are unique in some respect—bringing benefits and challenges to the power system—and wholesale markets, industry investments, and operational procedures have evolved over time to manage the characteristics of a changing generation fleet. With increased VRE penetrations, power system planners, operators, regulators, and policymakers will continue to be challenged to develop methods to smoothly and cost-effectively manage the reliable integration of these new and growing sources of electricity supply.« less

Insights Into Hypertrophic Cardiomyopathy Evaluation Through Follow-up of a Founder Pathogenic Variant.

PubMed

Lorca, Rebeca; Gómez, Juan; Martín, María; Cabanillas, Rubén; Calvo, Juan; León, Víctor; Pascual, Isaac; Morís, César; Coto, Eliecer; R Reguero, José Julián

2018-04-06

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease. The current challenge relies on the accurate classification of the pathogenicity of the variants. Transthoracic echocardiography (TTE) is recommended at initial evaluation and cardiac magnetic resonance (CMR) imaging should also be considered. We aimed to reappraise the penetrance and clinical expression of the MYBPC3 p.G263* variant. Three hundred and eighty-four HCM probands and a control cohort of 450 individuals were studied for the main sarcomere genes by next-generation sequencing. All MYBPC3 p.G263* carriers were identified and family screening was performed. Clinical information was recorded retrospectively before 2015 and prospectively thereafter. Extra effort was invested in performing CMR in all carriers, despite TTE results. Thirteen HCM probands and none of the controls were carriers of the MYBPC3 p.G263* pathogenic variant (according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology). A total of 39 carriers were identified with family screening. Most patients with HCM were asymptomatic at the time of diagnosis and showed late-onset disease. Despite having a relatively benign course in the young, late HCM-related complications could occur. Penetrance was around 70% when evaluated by TTE and was 87.2% with TTE plus CMR. Penetrance was age-dependent, reaching 100% in carriers older than 55 years. MYBPC3 p.G263* shares with most truncating pathogenic variants in this gene a late onset, relatively benign clinical course in the young, and high penetrance. Cardiac magnetic resonance could be a useful tool to evaluate carriers despite TTE results. Copyright © 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Parametric effect on the mixing of the combination of a hydrogen porthole with an air porthole in transverse gaseous injection flow fields

NASA Astrophysics Data System (ADS)

Li, Lang-quan; Huang, Wei; Yan, Li; Li, Shi-bin

2017-10-01

The dual transverse injection system with a front hydrogen porthole and a rear air porthole arranged in tandem is proposed, and this is a realistic approach for mixing enhancement and penetration improvement of transverse injection in a scramjet combustor. The influence of this dual transverse injection system on mixing characteristics has been evaluated numerically based on grid independency analysis and code validation. The numerical approach employed in the current study has been validated against the available experimental data in the open literature, and the predicted wall static pressure distributions show reasonable agreement with the experimental data for the cases with different jet-to-crossflow pressure ratios. The obtained results predicted by the three-dimensional Reynolds-average Navier - Stokes (RANS) equations coupled with the two equation k-ω shear stress transport (SST) turbulence model show that the air pothole has an great impact on penetration depth and mixing efficiency, and the effect of air jet on flow field varies with different values of the aspect ratio. The air porthole with larger aspect ratio can increase the fuel penetration depth. However, when the aspect ratio is relatively small, the fuel penetration depth decreases, and even smaller than that of the single injection system. At the same time, the air pothole has a highly remarkable improvement on mixing efficiency, especially in the near field. The smaller the aspect ratio of the air porthole is, the higher the mixing efficiency in the near field is. This is due to its larger circulation in the near field. The dual injection system owns more losses of stagnation pressure than the single injection system.

MECHANISMS OF MICROBIAL MOVEMENT IN SUBSURFACE MATERIALS

EPA Science Inventory

The biological factors important in the penetration of Escherichia coli through anaerobic, nutrient-saturated, Ottawa sand-packed cores were studied under static conditions. In cores saturated with galactose-peptone medium, motile strains of E. coli penetrated four times faster t...

Structure-activity relationship of chemical penetration enhancers in transdermal drug delivery.

PubMed

Kanikkannan, N; Kandimalla, K; Lamba, S S; Singh, M

2000-06-01

Transdermal drug delivery (TDD) is the administration of therapeutic agents through intact skin for systemic effect. TDD offers several advantages over the conventional dosage forms such as tablets, capsules and injections. Currently there are about eight drugs marketed as transdermal patches. Examples of such products include nitroglycerin (angina pectoris), clonidine (hypertension), scopolamine (motion sickness), nicotine (smoking cessation), fentanil (pain) and estradiol (estrogen deficiency). Since skin is an excellent barrier for drug transport, only potent drugs with appropriate physicochemical properties (low molecular weight, adequate solubility in aqueous and non-aqueous solvents, etc) are suitable candidates for transdermal delivery. Penetration enhancement technology is a challenging development that would increase significantly the number of drugs available for transdermal administration. The permeation of drugs through skin can be enhanced by physical methods such as iontophoresis (application of low level electric current) and phonophoresis (use of ultra sound energy) and by chemical penetration enhancers (CPE). In this review, we have discussed about the CPE which have been investigated for TDD. CPE are compounds that enhance the permeation of drugs across the skin. The CPE increase skin permeability by reversibly altering the physicochemical nature of the stratum corneum, the outer most layer of skin, to reduce its diffusional resistance. These compounds increase skin permeability also by increasing the partition coefficient of the drug into the skin and by increasing the thermodynamic activity of the drug in the vehicle. This review compiles the various CPE used for the enhancement of TDD, the mechanism of action of different chemical enhancers and the structure-activity relationship of selected and extensively studied enhancers such as fatty acids, fatty alcohols and terpenes. Based on the chemical structure of penetration enhancers (such as chain length, polarity, level of unsaturation and presence of some special groups such as ketones), the interaction between the stratum corneum and penetration enhancers may vary which will result in significant differences in penetration enhancement. Our review also discusses the various factors to be considered in the selection of an appropriate penetration enhancer for the development of transdermal delivery systems.

Feedbacks between soil penetration resistance, root architecture and water uptake limit water accessibility and crop growth - A vicious circle.

PubMed

Colombi, Tino; Torres, Lorena Chagas; Walter, Achim; Keller, Thomas

2018-06-01

Water is the most limiting resource for global crop production. The projected increase of dry spells due to climate change will further increase the problem of water limited crop yields. Besides low water abundance and availability, water limitations also occur due to restricted water accessibility. Soil penetration resistance, which is largely influenced by soil moisture, is the major soil property regulating root elongation and water accessibility. Until now the interactions between soil penetration resistance, root system properties, water uptake and crop productivity are rarely investigated. In the current study we quantified how interactive effects between soil penetration resistance, root architecture and water uptake affect water accessibility and crop productivity in the field. Maize was grown on compacted and uncompacted soil that was either tilled or remained untilled after compaction, which resulted in four treatments with different topsoil penetration resistance. Higher topsoil penetration resistance caused root systems to be shallower. This resulted in increased water uptake from the topsoil and hence topsoil drying, which further increased the penetration resistance in the uppermost soil layer. As a consequence of this feedback, root growth into deeper soil layers, where water would have been available, was reduced and plant growth decreased. Our results demonstrate that soil penetration resistance, root architecture and water uptake are closely interrelated and thereby determine the potential of plants to access soil water pools. Hence, these interactions and their feedbacks on water accessibility and crop productivity have to be accounted for when developing strategies to alleviate water limitations in cropping systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Validation of the CNS Penetration-Effectiveness Rank for Quantifying Antiretroviral Penetration Into the Central Nervous System

PubMed Central

Letendre, Scott; Marquie-Beck, Jennifer; Capparelli, Edmund; Best, Brookie; Clifford, David; Collier, Ann C.; Gelman, Benjamin B.; McArthur, Justin C.; McCutchan, J. Allen; Morgello, Susan; Simpson, David; Grant, Igor; Ellis, Ronald J.

2009-01-01

Objective To evaluate whether penetration of a combination regimen into the central nervous system (CNS), as estimated by the CNS Penetration-Effectiveness (CPE) rank, is associated with lower cerebrospinal fluid (CSF) viral load. Design Data were analyzed from 467 participants who were human immunodeficiency virus (HIV) seropositive and who reported antiretroviral (ARV) drug use. Individual ARV drugs were assigned a penetration rank of 0 (low), 0.5 (intermediate), or 1 (high) based on their chemical properties, concentrations in CSF, and/or effectiveness in the CNS in clinical studies. The CPE rank was calculated by summing the individual penetration ranks for each ARV in the regimen. Results The median CPE rank was 1.5 (interquartile range, 1–2). Lower CPE ranks correlated with higher CSF viral loads. Ranks less than 2 were associated with an 88% increase in the odds of detectable CSF viral load. In multivariate regression, lower CPE ranks were associated with detectable CSF viral loads even after adjusting for total number of ARV drugs, ARV drug adherence, plasma viral load, duration and type of the current regimen, and CD4 count. Conclusions Poorer penetration of ARV drugs into the CNS appears to allow continued HIV replication in the CNS as indicated by higher CSF HIV viral loads. Because inhibition of HIV replication in the CNS is probably critical in treating patients who have HIV-associated neurocognitive disorders, ARV treatment strategies that account for CNS penetration should be considered in consensus treatment guidelines and validated in clinical studies. PMID:18195140

A Genetic Algorithm Based Support Vector Machine Model for Blood-Brain Barrier Penetration Prediction

PubMed Central

Zhang, Daqing; Xiao, Jianfeng; Zhou, Nannan; Luo, Xiaomin; Jiang, Hualiang; Chen, Kaixian

2015-01-01

Blood-brain barrier (BBB) is a highly complex physical barrier determining what substances are allowed to enter the brain. Support vector machine (SVM) is a kernel-based machine learning method that is widely used in QSAR study. For a successful SVM model, the kernel parameters for SVM and feature subset selection are the most important factors affecting prediction accuracy. In most studies, they are treated as two independent problems, but it has been proven that they could affect each other. We designed and implemented genetic algorithm (GA) to optimize kernel parameters and feature subset selection for SVM regression and applied it to the BBB penetration prediction. The results show that our GA/SVM model is more accurate than other currently available log BB models. Therefore, to optimize both SVM parameters and feature subset simultaneously with genetic algorithm is a better approach than other methods that treat the two problems separately. Analysis of our log BB model suggests that carboxylic acid group, polar surface area (PSA)/hydrogen-bonding ability, lipophilicity, and molecular charge play important role in BBB penetration. Among those properties relevant to BBB penetration, lipophilicity could enhance the BBB penetration while all the others are negatively correlated with BBB penetration. PMID:26504797

Enhanced chlorhexidine skin penetration with eucalyptus oil

PubMed Central

2010-01-01

Background Chlorhexidine digluconate (CHG) is a widely used skin antiseptic, however it poorly penetrates the skin, limiting its efficacy against microorganisms residing beneath the surface layers of skin. The aim of the current study was to improve the delivery of chlorhexidine digluconate (CHG) when used as a skin antiseptic. Method Chlorhexidine was applied to the surface of donor skin and its penetration and retention under different conditions was evaluated. Skin penetration studies were performed on full-thickness donor human skin using a Franz diffusion cell system. Skin was exposed to 2% (w/v) CHG in various concentrations of eucalyptus oil (EO) and 70% (v/v) isopropyl alcohol (IPA). The concentration of CHG (μg/mg of skin) was determined to a skin depth of 1500 μm by high performance liquid chromatography (HPLC). Results The 2% (w/v) CHG penetration into the lower layers of skin was significantly enhanced in the presence of EO. Ten percent (v/v) EO in combination with 2% (w/v) CHG in 70% (v/v) IPA significantly increased the amount of CHG which penetrated into the skin within 2 min. Conclusion The delivery of CHG into the epidermis and dermis can be enhanced by combination with EO, which in turn may improve biocide contact with additional microorganisms present in the skin, thereby enhancing antisepsis. PMID:20860796

Skin penetration surrogate for the evaluation of less lethal kinetic energy munitions.

PubMed

Bir, Cynthia A; Resslar, Marianne; Stewart, Shelby

2012-07-10

Although the benefits of the use of less lethal kinetic energy munitions are numerous, there is a need to evaluate the munitions prior to deployment to ensure their intended effect. The objective of the current research was to validate a surrogate that could be used to predict the risk of penetration of these devices. Existing data from biomechanical testing with post-mortem human specimens (PMHS) served as the foundation for this research. Development of the surrogate involved simulating the various layers of the skin and underlying soft tissues using a combination of materials. A standardized 12-gauge impactor was used to assess each combination. The energy density that resulted in a 50% risk of penetration for the anterior thorax region (23.99 J/cm(2)) from the previous research was matched using a specific combination of layers. Twelve various combinations of materials were tested with the 50% risk of penetration determined. The final validated surrogate consisted of a Laceration Assessment Layer (LAL) of natural chamois and .6 cm of closed-cell foam over a Penetration Assessment Layer (PAL) of 20% ordnance gelatin. This surrogate predicted a 50% risk of penetration at 23.88 J/cm(2). Injury risk curves for the PMHS and surrogate development work are presented. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Correlated matrix-fluctuation-mediated activated transport of dilute penetrants in glass-forming liquids and suspensions

NASA Astrophysics Data System (ADS)

Zhang, Rui; Schweizer, Kenneth S.

2017-05-01

We formulate a microscopic, force-level statistical mechanical theory for the activated diffusion of dilute penetrants in dense liquids, colloidal suspensions, and glasses. The approach explicitly and self-consistently accounts for coupling between penetrant hopping and matrix dynamic displacements that actively facilitate the hopping event. The key new ideas involve two mechanistically (at a stochastic trajectory level) coupled dynamic free energy functions for the matrix and spherical penetrant particles. A single dynamic coupling parameter quantifies how much the matrix displaces relative to the penetrant when the latter reaches its transition state which is determined via the enforcement of a temporal causality or coincidence condition. The theory is implemented for dilute penetrants smaller than the matrix particles, with or without penetrant-matrix attractive forces. Model calculations reveal a rich dependence of the penetrant diffusion constant and degree of dynamic coupling on size ratio, volume fraction, and attraction strength. In the absence of attractions, a near exponential decrease of penetrant diffusivity with size ratio over an intermediate range is predicted, in contrast to the much steeper, non-exponential variation if one assumes local matrix dynamical fluctuations are not correlated with penetrant motion. For sticky penetrants, the relative and absolute influence of caging versus physical bond formation is studied. The conditions for a dynamic crossover from the case where a time scale separation between penetrant and matrix activated hopping exists to a "slaved" or "constraint release" fully coupled regime are determined. The particle mixture model is mapped to treat experimental thermal systems and applied to make predictions for the diffusivity of water, toluene, methanol, and oxygen in polyvinylacetate liquids and glasses. The theory agrees well with experiment with values of the penetrant-matrix size ratio close to their chemically intuitive values.

Correlated matrix-fluctuation-mediated activated transport of dilute penetrants in glass-forming liquids and suspensions

PubMed Central

Schweizer, Kenneth S.

2017-01-01

We formulate a microscopic, force-level statistical mechanical theory for the activated diffusion of dilute penetrants in dense liquids, colloidal suspensions, and glasses. The approach explicitly and self-consistently accounts for coupling between penetrant hopping and matrix dynamic displacements that actively facilitate the hopping event. The key new ideas involve two mechanistically (at a stochastic trajectory level) coupled dynamic free energy functions for the matrix and spherical penetrant particles. A single dynamic coupling parameter quantifies how much the matrix displaces relative to the penetrant when the latter reaches its transition state which is determined via the enforcement of a temporal causality or coincidence condition. The theory is implemented for dilute penetrants smaller than the matrix particles, with or without penetrant-matrix attractive forces. Model calculations reveal a rich dependence of the penetrant diffusion constant and degree of dynamic coupling on size ratio, volume fraction, and attraction strength. In the absence of attractions, a near exponential decrease of penetrant diffusivity with size ratio over an intermediate range is predicted, in contrast to the much steeper, non-exponential variation if one assumes local matrix dynamical fluctuations are not correlated with penetrant motion. For sticky penetrants, the relative and absolute influence of caging versus physical bond formation is studied. The conditions for a dynamic crossover from the case where a time scale separation between penetrant and matrix activated hopping exists to a “slaved” or “constraint release” fully coupled regime are determined. The particle mixture model is mapped to treat experimental thermal systems and applied to make predictions for the diffusivity of water, toluene, methanol, and oxygen in polyvinylacetate liquids and glasses. The theory agrees well with experiment with values of the penetrant-matrix size ratio close to their chemically intuitive values. PMID:28527449

Are high penetrations of commercial cogeneration good for society?

NASA Astrophysics Data System (ADS)

Keen, Jeremy F.; Apt, Jay

2016-12-01

Low natural gas prices, market reports and evidence from New York State suggest that the number of commercial combined heat and power (CHP) installations in the United States will increase by 2%-9% annually over the next decade. We investigate how increasing commercial CHP penetrations may affect net emissions, the distribution network, and total system energy costs. We constructed an integrated planning and operations model that maximizes owner profit through sizing and operation of CHP on a realistic distribution feeder in New York. We find that a greater penetration of CHP reduces both total system energy costs and network congestion. Commercial buildings often have low and inconsistent heat loads, which can cause low fuel utilization efficiencies, low CHP rates-of-return and diminishing avoided emissions as CHP penetration increases. In the northeast, without policy intervention, a 5% penetration of small commercially owned CHP would increase CO2 emissions by 2% relative to the bulk power grid. Low emission CHP installations can be encouraged with incentives that promote CHP operation only during times of high heat loads. Time-varying rates, such as time-of-day and seasonal rates, are one option and were shown to reduce customer emissions without reducing profits. In contrast, natural gas rate discounts, a common incentive for industrial CHP in some states, can encourage CHP operation during low heat loads and thus increase emissions.

Effect of flask vibration time on casting integrity, Surface Penetration and Coating Inclusion in lost foam casting of Al-Si Alloy

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

Karimian, Majid; Idris, M. H.; Ourdjini, A.

2011-01-17

The paper presents the result of an experimental investigation conducted on medium aluminum silicon alloy casting- LM6, using no-vacuum assisted lost foam casting process. The study is directed for establishing the relationship between the flask vibrations times developed for molded sample on the casting integrity, surface penetration and coating inclusion defects of the casting. Four different flask vibration times namely 180, 120, 90 and 60 sec. were investigated. The casting integrity was investigated in terms of fulfilling in all portions and edges. The surface penetration was measured using optical microscope whilst image analyzer was used to quantify the percentage ofmore » coating inclusion in the casting. The results show that vibration time has significant influence on the fulfilling as well as the internal integrity of the lost foam casting. It was found that the lower vibration time produced comparatively sound casing.« less

Sensitivity and comparison evaluation of Saturn 5 liquid penetrants

NASA Technical Reports Server (NTRS)

Jones, G. H.

1973-01-01

Results of a sensitivity and comparison evaluation performed on six liquid penetrants that were used on the Saturn 5 vehicle and other space hardware to detect surface discontinuities are described. The relationship between penetrant materials and crack definition capabilities, the optimum penetrant materials evaluation method, and the optimum measurement methods for crack dimensions were investigated. A unique method of precise developer thickness control was envolved, utilizing clear radiographic film and a densitometer. The method of evaluation included five aluminum alloy, 2219-T87, specimens that were heated and then quenched in cold water to produce cracks. The six penetrants were then applied, one at a time, and the crack indications were counted and recorded for each penetrant for comparison purposes. Measurements were made by determining the visual crack indications per linear inch and then sectioning the specimens for a metallographic count of the cracks present. This method provided a numerical approach for assigning a sensitivity index number to the penetrants. Of the six penetrants evaluated, two were not satisfactory (one was not sufficiently sensitive and the other was to sensitive, giving false indications). The other four were satisfactory with approximately the same sensitivity in the range of 78 to 80.5 percent of total cracks detected.

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

Jeong, Sang Hoon; Kim, Jae Hwan; Yi, Sang Min

Quantum dots (QDs) are rapidly emerging as an important class of nanoparticles (NPs) with potential applications in medicine. However, little is known about penetration of QDs through human skin. This study investigated skin penetration of QDs in both in vivo and in vitro human skin. Using the tape stripping method, this study demonstrates for the first time that QDs can actually penetrate through the stratum corneum (SC) of human skin. Transmission electron microscope (TEM) and energy diverse X-ray (EDX) analysis showed accumulation of QDs in the SC of a human skin equivalent model (HSEM) after dermal exposure to QDs. Thesemore » findings suggest possible transdermal absorption of QDs after dermal exposure over a relatively long period of time.« less

The use of electromagnetic body forces to enhance the quality of laser welds

NASA Astrophysics Data System (ADS)

Ambrosy, Guenter; Berger, P.; Huegel, H.; Lindenau, D.

2003-11-01

The use of electromagnetic body forces in laser beam welding of aluminum alloys is a new method to shape the geometry and to enhance the quality of the weld seams. In this new approach, electromagnetic volume forces are utilized by applying magnetic fields and electric currents of various origins. Acting in the liquid metal, they directly affect the flow field and can lead to favourable conditions for the melt dynamics and energy coupling. Numerous welds with full and partial penetration using both CO2 and Nd:YAG lasers demonstrate that this method directly influences the seam geometry and top-bead topography as well as the penetration depth and the evolution of pores and cracks. In the case of full penetration, it is also possible to lift or to lower the weld pool. The method, therefore, can be used to shape the geometry and to enhance the quality of the weld seam. Depending on the orientation of an external magnetic field, significant impacts are achieved in CO2 welding, even without an external current: the shape of the cross-sectional area can be increased of up to 50% and also the seam width is changed. Whereas for such conditions with Nd:YAG lasers no significant effect could be observed, it turned out that, when an external electric current is applied, similar effects are present with both wavelengths. In further investigations, the effect of electromagnetic body forces resulting from the interaction of an external current and its self-induced magnetic field was studied. Hereby, the current was fed into the workpiece via a tungsten electrode or a filler wire. The resulting phenomena are the same independent from wavelength and means of current feed.

The effect of the corneal epithelium on the intraocular penetration of fluoroquinolone ophthalmic solution.

PubMed

Fukuda, Masamichi; Inoue, Amane; Sasaki, Kazuyuki; Takahashi, Nobuo

2004-01-01

Pharmacokinetic studies of antibacterial agents for infectious eye diseases have usually been performed on normal rabbit eyes. In this study, the intraocular penetration of fluoroquinolone ophthalmic solutions was determined in normal rabbit eyes and in rabbit eyes that had the corneal epithelium intentionally removed. We determined the intraocular penetration of ofloxacin (OFLX), levofloxacin (LVFX), and norfloxacin (NFLX), fluoroquinolone ophthalmic solutions that are already on the market and undergoing clinical studies, by injecting 50 microl of each solution into the cul-de-sacs of rabbit eyes three times at 15-min intervals. The drug concentration at 10, 30, 60, 120, and 240 min after final instillation was determined by high-performance liquid chromatography. The maximum concentration in the aqueous humor of normal rabbit eyes was 2.09 +/- 1.56 microg/ml (60 min, OFLX), 2.57 +/- 1.00 microg/ml (30 min, LVFX), and 0.42 +/- 0.12 microg/ml (120 min, NFLX). The drug concentration in the aqueous humor of eyes with intentionally removed corneal epithelium was 12.50 +/- 5.62 microg/ml (30 min, OFLX), 9.02 +/- 2.45 microg/ml (60 min, LVFX), and 8.54 +/- 5.17 microg/ml (30 min, NFLX). The drug penetration of the eye drops into eyes with removed corneal epithelium was around 6 times (OFLX), 3.5 times (LVFX), and 20 times (NFLX) higher than the penetration into the eye with normal cornea. Among the pharmacokinetic parameters of the three ophthalmic solutions according to the one-compartment model, the maximum concentration in the aqueous and the area under the concentration-time curve in the aqueous tended to be higher in the eyes with intentionally removed corneal epithelia than in those with normal corneas.

Detection of Only Viable Bacterial Spores Using a Live/Dead Indicator in Mixed Populations

NASA Technical Reports Server (NTRS)

Behar, Alberto E.; Stam, Christina N.; Smiley, Ronald

2013-01-01

This method uses a photoaffinity label that recognizes DNA and can be used to distinguish populations of bacterial cells from bacterial spores without the use of heat shocking during conventional culture, and live from dead bacterial spores using molecular-based methods. Biological validation of commercial sterility using traditional and alternative technologies remains challenging. Recovery of viable spores is cumbersome, as the process requires substantial incubation time, and the extended time to results limits the ability to quickly evaluate the efficacy of existing technologies. Nucleic acid amplification approaches such as PCR (polymerase chain reaction) have shown promise for improving time to detection for a wide range of applications. Recent real-time PCR methods are particularly promising, as these methods can be made at least semi-quantitative by correspondence to a standard curve. Nonetheless, PCR-based methods are rarely used for process validation, largely because the DNA from dead bacterial cells is highly stable and hence, DNA-based amplification methods fail to discriminate between live and inactivated microorganisms. Currently, no published method has been shown to effectively distinguish between live and dead bacterial spores. This technology uses a DNA binding photoaffinity label that can be used to distinguish between live and dead bacterial spores with detection limits ranging from 109 to 102 spores/mL. An environmental sample suspected of containing a mixture of live and dead vegetative cells and bacterial endospores is treated with a photoaffinity label. This step will eliminate any vegetative cells (live or dead) and dead endospores present in the sample. To further determine the bacterial spore viability, DNA is extracted from the spores and total population is quantified by real-time PCR. The current NASA standard assay takes 72 hours for results. Part of this procedure requires a heat shock step at 80 degC for 15 minutes before the sample can be plated. Using a photoaffinity label would remove this step from the current assay as the label readily penetrates both live and dead bacterial cells. Secondly, the photoaffinity label can only penetrate dead bacterial spores, leaving behind the viable spore population. This would allow for rapid bacterial spore detection in a matter of hours compared to the several days that it takes for the NASA standard assay.

SMAW Ceramic Weld Backing Evaluation

DTIC Science & Technology

1982-03-01

marked similarity to the open root technique in that the " keyhole " technique, commnly used to maxmize penetration with SMAW open root welding , was also...melt into the sides of the bevel and penetrate into the root opening to form a keyhole . Once the keyhole was established, normal welding current was...hot start to melt through the taper, welding proceeded to the keyhole . Once in the keyhole , the electrode was positioned in front of the puddle but not

NASA Astrophysics Data System (ADS)

Tube to tube-sheet joints in heat exchangers are currently welded by the orbital TIG process characterized by very high quality of the weld beads and good repeatability. However, due to high number of welds, a reduction in the welding cycle time would have an interesting impact on manufacturing costs and delays and laser welding technology is aimed to improve this factor. The main disadvantage is the positioning accuracy required by the laser welding process since beam deviations from real joint cause lack of penetration. It is expected that the Orbital laser welding head developed under the European project ORBITAL will avoid this drawback.

Perennially ice-covered Lake Hoare, Antarctica: physical environment, biology and sedimentation

NASA Technical Reports Server (NTRS)

Wharton, R. A. Jr; Simmons, G. M. Jr; McKay, C. P.; Wharton RA, J. r. (Principal Investigator)

1989-01-01

Lake Hoare (77 degrees 38' S, 162 degrees 53' E) is a perennially ice-covered lake at the eastern end of Taylor Valley in southern Victoria Land, Antarctica. The environment of this lake is controlled by the relatively thick ice cover (3-5 m) which eliminates wind generated currents, restricts gas exchange and sediment deposition, and reduces light penetration. The ice cover is in turn largely controlled by the extreme seasonality of Antarctica and local climate. Lake Hoare and other dry valley lakes may be sensitive indicators of short term (< 100 yr) climatic and/or anthropogenic changes in the dry valleys since the onset of intensive exploration over 30 years ago. The time constants for turnover of the water column and lake ice are 50 and 10 years, respectively. The turnover time for atmospheric gases in the lake is 30-60 years. Therefore, the lake environment responds to changes on a 10-100 year timescale. Because the ice cover has a controlling influence on the lake (e.g. light penetration, gas content of water, and sediment deposition), it is probable that small changes in ice ablation, sediment loading on the ice cover, or glacial meltwater (or groundwater) inflow will affect ice cover dynamics and will have a major impact on the lake environment and biota.

Penetration depth of photons in biological tissues from hyperspectral imaging in shortwave infrared in transmission and reflection geometries

PubMed Central

Zhang, Hairong; Salo, Daniel; Kim, David M.; Komarov, Sergey; Tai, Yuan-Chuan; Berezin, Mikhail Y.

2016-01-01

Abstract. Measurement of photon penetration in biological tissues is a central theme in optical imaging. A great number of endogenous tissue factors such as absorption, scattering, and anisotropy affect the path of photons in tissue, making it difficult to predict the penetration depth at different wavelengths. Traditional studies evaluating photon penetration at different wavelengths are focused on tissue spectroscopy that does not take into account the heterogeneity within the sample. This is especially critical in shortwave infrared where the individual vibration-based absorption properties of the tissue molecules are affected by nearby tissue components. We have explored the depth penetration in biological tissues from 900 to 1650 nm using Monte–Carlo simulation and a hyperspectral imaging system with Michelson spatial contrast as a metric of light penetration. Chromatic aberration-free hyperspectral images in transmission and reflection geometries were collected with a spectral resolution of 5.27 nm and a total acquisition time of 3 min. Relatively short recording time minimized artifacts from sample drying. Results from both transmission and reflection geometries consistently revealed that the highest spatial contrast in the wavelength range for deep tissue lies within 1300 to 1375 nm; however, in heavily pigmented tissue such as the liver, the range 1550 to 1600 nm is also prominent. PMID:27930773

Nonlinear Dynamics of Vortices in Different Types of Grain Boundaries

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

Sheikhzada, Ahmad

As a major component of linear particle accelerators, superconducting radio-frequency (SRF) resonator cavities are required to operate with lowest energy dissipation and highest accelerating gradient. SRF cavities are made of polycrystalline materials in which grain boundaries can limit maximum RF currents and produce additional power dissipation sources due to local penetration of Josephson vortices. The essential physics of vortex penetration and mechanisms of dissipation of vortices driven by strong RF currents along networks of grain boundaries and their contribution to the residual surface resistance have not been well understood. To evaluate how GBs can limit the performance of SRF materials,more » particularly Nb and Nb3Sn, we performed extensive numerical simulations of nonlinear dynamics of Josephson vortices in grain boundaries under strong dc and RF fields. The RF power due to penetration of vortices both in weakly-coupled and strongly-coupled grain boundaries was calculated as functions of the RF field and frequency. The result of this calculation manifested a quadratic dependence of power to field amplitude at strong RF currents, an illustration of resistive behavior of grain boundaries. Our calculations also showed that the surface resistance is a complicated function of field controlled by penetration and annihilation of vortices and antivortices in strong RF fields which ultimately saturates to normal resistivity of grain boundary. We found that Cherenkov radiation of rapidly moving vortices in grain boundaries can produce a new instability causing generation of expanding vortex-antivortex pair which ultimately drives the entire GB in a resistive state. This effect is more pronounced in polycrystalline thin film and multilayer coating structures in which it can cause significant increase in power dissipation and results in hysteresis effects in I-V characteristics, particularly at low temperatures.« less

Effect of Heat Input on Geometry of Austenitic Stainless Steel Weld Bead on Low Carbon Steel

NASA Astrophysics Data System (ADS)

Saha, Manas Kumar; Hazra, Ritesh; Mondal, Ajit; Das, Santanu

2018-05-01

Among different weld cladding processes, gas metal arc welding (GMAW) cladding becomes a cost effective, user friendly, versatile method for protecting the surface of relatively lower grade structural steels from corrosion and/or erosion wear by depositing high grade stainless steels onto them. The quality of cladding largely depends upon the bead geometry of the weldment deposited. Weld bead geometry parameters, like bead width, reinforcement height, depth of penetration, and ratios like reinforcement form factor (RFF) and penetration shape factor (PSF) determine the quality of the weld bead geometry. Various process parameters of gas metal arc welding like heat input, current, voltage, arc travel speed, mode of metal transfer, etc. influence formation of bead geometry. In the current experimental investigation, austenite stainless steel (316) weld beads are formed on low alloy structural steel (E350) by GMAW using 100% CO2 as the shielding gas. Different combinations of current, voltage and arc travel speed are chosen so that heat input increases from 0.35 to 0.75 kJ/mm. Nine number of weld beads are deposited and replicated twice. The observations show that weld bead width increases linearly with increase in heat input, whereas reinforcement height and depth of penetration do not increase with increase in heat input. Regression analysis is done to establish the relationship between heat input and different geometrical parameters of weld bead. The regression models developed agrees well with the experimental data. Within the domain of the present experiment, it is observed that at higher heat input, the weld bead gets wider having little change in penetration and reinforcement; therefore, higher heat input may be recommended for austenitic stainless steel cladding on low alloy steel.

Poker flat radar observations of the magnetosphere-ionosphere coupling electrodynamics of the earthward penetrating plasma sheet following convection enhancements

NASA Astrophysics Data System (ADS)

Lyons, L. R.; Zou, S.; Heinselman, C. J.; Nicolls, M. J.; Anderson, P. C.

2009-05-01

The plasma sheet moves earthward (equatorward in the ionosphere) after enhancements in convection, and the electrodynamics of this response is strongly influenced by Region 2 magnetosphere-ionosphere coupling. We have used Poker Flat Advanced Modular Incoherent Scatter Radar (PFISR) observations associated with two relatively abrupt southward turnings of the IMF to provide an initial evaluation of aspects of this response. The observations show that strong westward sub-auroral polarization streams (SAPS) flow regions moved equatorward as the plasma sheet electron precipitation (the diffuse aurora) penetrated equatorward following the IMF southward turnings. Consistent with our identification of these flows as SAPS, concurrent DMSP particle precipitation measurements show the equatorial boundary of ion precipitation equatorward of the electron precipitation boundary and that westward flows lie within the low-conductivity region between the two boundaries where the plasma sheet ion pressure gradient is expected to drive downward R2 currents. Evidence for these downward currents is seen in the DMSP magnetometer observations. Preliminary examination indicates that the SAPS response seen in the examples presented here may be common. However, detailed analysis will be required for many more events to reliably determine if this is the case. If so, it would imply that SAPS are frequently an important aspect of the inner magnetospheric electric field distribution, and that they are critical for understanding the response of the magnetosphere-ionosphere system to enhancements in convection, including understanding the earthward penetration of the plasma sheet. This earthward penetration is critical to geomagnetic disturbance phenomena such as the substorm growth phase and the formation of the stormtime ring current. Additionally, for one example, a prompt electric field response to the IMF southward turnings is seen within the inner plasma sheet.

Accumulation and dissipation of positive charges induced on a PMMA build-up cap of an ionisation chamber by (60)Co gamma-ray irradiation.

PubMed

Morishita, Y; Takata, N

2013-07-01

The signal current from an ionisation chamber with a PMMA build-up cap decreases with irradiation time due to electric fields produced by positive charges induced on the cap. In the present study, it was confirmed that the signal current decreases faster for irradiation using narrower (60)Co gamma-ray beams. This is because the number of secondary electrons that are emitted from surrounding materials and penetrate the build-up cap is smaller in a narrower gamma-ray beam, so that fewer positive charges are neutralised. The ionisation chamber was first subjected to continuous gamma-ray irradiation for 24 h, following which it was irradiated with shorter periodic gamma-ray bursts while measuring the current signal. This allowed the coefficients of positive charge accumulation and dissipation to be determined. It was found that the dissipation coefficient has a large constant value during gamma-ray irradiation and decreases asymptotically to a small value after irradiation is stopped. From the coefficients, the minimum signal current was calculated, which is the value when accumulation and dissipation balance each other under continuous irradiation. The time required for the signal current to recover following irradiation was also calculated.

Low-cost wireless voltage & current grid monitoring

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

Hines, Jacqueline

This report describes the development and demonstration of a novel low-cost wireless power distribution line monitoring system. This system measures voltage, current, and relative phase on power lines of up to 35 kV-class. The line units operate without any batteries, and without harvesting energy from the power line. Thus, data on grid condition is provided even in outage conditions, when line current is zero. This enhances worker safety by detecting the presence of voltage and current that may appear from stray sources on nominally isolated lines. Availability of low-cost power line monitoring systems will enable widespread monitoring of the distributionmore » grid. Real-time data on local grid operating conditions will enable grid operators to optimize grid operation, implement grid automation, and understand the impact of solar and other distributed sources on grid stability. The latter will enable utilities to implement eneygy storage and control systems to enable greater penetration of solar into the grid.« less

Evaluation of Standard Loose Plastic Packaging for the Management of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebriondiae)

PubMed Central

Hassan, Muhammad Waqar; Gulraize; Ali, Usman; Ur Rehman, Fazal; Najeeb, Hafsa; Sohail, Maryam; Irsa, Bakhtawar; Muzaffar, Zubaria; Chaudhry, Muhammad Shafiq

2016-01-01

Three standard foodstuff plastic packaging namely polyethylene (PE), polypropylene (PP), and polyvinylchloride (PVC) were evaluated for management of lesser grain borer Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Resistance parameters in packaging were recorded as punctures, holes, penetrations, sealing defects, and invasions with two thicknesses and tested for two lengths of time. Damages like punctures, holes and penetrations by both insects were more in PE packaging however R. dominica made more penetrations in PP than in PE. For both insects sealing defects and invasions were predominant in PVC than in others. Thickness did not affect significantly damage types but significantly more holes and penetrations by R. dominica were in less thickness. Punctures and holes by R. dominica were more after less time period but other damages in packaging were more after more time period. However for T. castaneum all sorts of damages were seen more after more time period. Overall categorization between two insects showed R. dominica made more penetrations and T. castaneum made more invasions compared with their counterparts. Pictures were taken under camera fitted microscope to magnify punctures and holes in different packaging and thicknesses. Insect mortality due to phosphine was more in PP and PE packaging and least in PVC packaging and thickness effect was marginal. T. castaneum mortality was significantly more after 48 h than after 24 h. Damages extent in packaging and fumigation results showed PP to be the best of three packaging materials to manage these insects. PMID:27638958

Numerical simulation of Forchheimer flow to a partially penetrating well with a mixed-type boundary condition

NASA Astrophysics Data System (ADS)

Mathias, Simon A.; Wen, Zhang

2015-05-01

This article presents a numerical study to investigate the combined role of partial well penetration (PWP) and non-Darcy effects concerning the performance of groundwater production wells. A finite difference model is developed in MATLAB to solve the two-dimensional mixed-type boundary value problem associated with flow to a partially penetrating well within a cylindrical confined aquifer. Non-Darcy effects are incorporated using the Forchheimer equation. The model is verified by comparison to results from existing semi-analytical solutions concerning the same problem but assuming Darcy's law. A sensitivity analysis is presented to explore the problem of concern. For constant pressure production, Non-Darcy effects lead to a reduction in production rate, as compared to an equivalent problem solved using Darcy's law. For fully penetrating wells, this reduction in production rate becomes less significant with time. However, for partially penetrating wells, the reduction in production rate persists for much larger times. For constant production rate scenarios, the combined effect of PWP and non-Darcy flow takes the form of a constant additional drawdown term. An approximate solution for this loss term is obtained by performing linear regression on the modeling results.

Time-resolved X-ray diffraction microprobe studies of the conversion of cellulose I to ethylenediamine-cellulose I

PubMed Central

Nishiyama, Yoshiharu; Wada, Masahisa; Hanson, B. Leif

2012-01-01

Structural changes during the treatment of films of highly crystalline microfibers of Cladophora cellulose with ethylenediamine (EDA) have been studied by time-resolved X-ray microprobe diffraction methods. As EDA penetrates the sample and converts cellulose I to EDA-cellulose I, the measured profile widths of reflections reveal changes in the shapes and average dimensions of cellulose I and EDA-cellulose I crystals. The (200) direction of cellulose I is most resistant to EDA penetration, with EDA penetrating most effectively at the hydrophilic edges of the hydrogen bonded sheets of cellulose chains. Most of the cellulose chains in the initial crystals of cellulose I are incorporated into crystals of EDA-cellulose I. The size of the emerging EDA-cellulose I crystals is limited to about half of their size in cellulose I, most likely due to strains introduced by the penetration of EDA molecules. There is no evidence of any gradual structural transition from cellulose I to EDA-cellulose I involving a continuously changing intermediate phase. Rather, the results point to a rapid transition to EDA-cellulose I in regions of the microfibrils that have been penetrated by EDA. PMID:22693365

Strategy of topical vaccination with nanoparticles

NASA Astrophysics Data System (ADS)

Jung, Sascha; Patzelt, Alexa; Otberg, Nina; Thiede, Gisela; Sterry, Wolfram; Lademann, Juergen

2009-03-01

Liposomes in the nanosize range have been recognized as a versatile drug delivery system of both hydrophilic and lipophilic molecules. In order to develop a liposome-based topical vaccination strategy, five different types of liposomes were tested as a putative vaccine delivery system on pig ear skin. The investigated liposomes mainly varied in size, lipid composition, and surface charge. Using hydrophilic and hydrophobic fluorescent dyes as model drugs, penetration behavior was studied by means of confocal laser scanning microscopy of intact skin and histological sections, respectively. Follicular penetration of the liposomes was measured in comparison to a standard, nonliposomal formulation at different time points. Dependent on time but independent of their different characters, the liposomes showed a significantly higher penetration depth into the hair follicles compared to the standard formulation. The standard formulation reached a relative penetration depth of 30% of the full hair follicle length after seven days, whereas amphoteric and cationic liposomes had reached ~70%. Penetration depth of negatively charged liposomes did not exceed 50% of the total follicle length. The fluorescence dyes were mainly detected in the hair follicle; only a small amount of dye was found in the upper parts of the epidermis.

Strategy of topical vaccination with nanoparticles.

PubMed

Jung, Sascha; Patzelt, Alexa; Otberg, Nina; Thiede, Gisela; Sterry, Wolfram; Lademann, Juergen

2009-01-01

Liposomes in the nanosize range have been recognized as a versatile drug delivery system of both hydrophilic and lipophilic molecules. In order to develop a liposome-based topical vaccination strategy, five different types of liposomes were tested as a putative vaccine delivery system on pig ear skin. The investigated liposomes mainly varied in size, lipid composition, and surface charge. Using hydrophilic and hydrophobic fluorescent dyes as model drugs, penetration behavior was studied by means of confocal laser scanning microscopy of intact skin and histological sections, respectively. Follicular penetration of the liposomes was measured in comparison to a standard, nonliposomal formulation at different time points. Dependent on time but independent of their different characters, the liposomes showed a significantly higher penetration depth into the hair follicles compared to the standard formulation. The standard formulation reached a relative penetration depth of 30% of the full hair follicle length after seven days, whereas amphoteric and cationic liposomes had reached approximately 70%. Penetration depth of negatively charged liposomes did not exceed 50% of the total follicle length. The fluorescence dyes were mainly detected in the hair follicle; only a small amount of dye was found in the upper parts of the epidermis.

Design and fabrication of realistic adhesively bonded joints

NASA Technical Reports Server (NTRS)

Shyprykevich, P.

1983-01-01

Eighteen bonded joint test specimens representing three different designs of a composite wing chordwise bonded splice were designed and fabricated using current aircraft industry practices. Three types of joints (full wing laminate penetration, two side stepped; midthickness penetration, one side stepped; and partial penetration, scarfed) were analyzed using state of the art elastic joint analysis modified for plastic behavior of the adhesive. The static tensile fail load at room temperature was predicted to be: (1) 1026 kN/m (5860 1b/in) for the two side stepped joint; (2) 925 kN/m (5287 1b/in) for the one side stepped joint; and (3) 1330 kN/m (7600 1b/in) for the scarfed joint. All joints were designed to fail in the adhesive.

Nanoparticle-Enabled Transdermal Drug Delivery Systems for Enhanced Dose Control and Tissue Targeting.

PubMed

Palmer, Brian C; DeLouise, Lisa A

2016-12-15

Transdermal drug delivery systems have been around for decades, and current technologies (e.g., patches, ointments, and creams) enhance the skin permeation of low molecular weight, lipophilic drugs that are efficacious at low doses. The objective of current transdermal drug delivery research is to discover ways to enhance skin penetration of larger, hydrophilic drugs and macromolecules for disease treatment and vaccination. Nanocarriers made of lipids, metals, or polymers have been successfully used to increase penetration of drugs or vaccines, control drug release, and target drugs to specific areas of skin in vivo. While more research is needed to identify the safety of nanocarriers, this technology has the potential to expand the use of transdermal routes of administration to a wide array of therapeutics. Here, we review the current state of nanoparticle skin delivery systems with special emphasis on targeting skin diseases.

Nanoparticle enabled transdermal drug delivery systems for enhanced dose control and tissue targeting

PubMed Central

Palmer, Brian C.; DeLouise, Lisa A.

2017-01-01

Transdermal drug delivery systems have been around for decades, and current technologies (e.g. patches, ointments, and creams) enhance the skin permeation of low molecular weight, lipophilic drugs that are efficacious at low doses. The objective of current transdermal drug delivery research is to discover ways to enhance skin penetration of larger, hydrophilic drugs and macromolecules for disease treatment and vaccination. Nanocarriers made of lipids, metals, or polymers have been successfully used to increase penetration of drugs or vaccines, control drug release, and target drugs to specific areas of skin in vivo. While more research is needed to identify the safety of nanocarriers, this technology has the potential to expand the use of transdermal routes of administration to a wide array of therapeutics. Here, we review the current state of nanoparticle skin delivery systems with special emphasis on targeting skin diseases. PMID:27983701

Hydrogel iontophoresis for gentamicin administration to the rabbit eye

NASA Astrophysics Data System (ADS)

Eljarrat-Binstock, Esther; Raiskup, Frederik; Frucht-Pery, Joseph; Domb, Abraham J.

2005-04-01

Iontophoresis (IONT) is a non-invasive technique in which a low electric current is used to enhance the penetration of charged molecules into tissue. This technique has been used in various fields of medicine, mostly in transdermal drug delivery. This study was aimed to evaluate the efficacy and the distribution profile of gentamicin using corneal IONT on infected and healthy rabbit eyes. Corneal iontophoresis of gentamicin sulfate was studied using drug-loaded disposable hydrogel probes mounted on a portable iontophoretic device, applying a low current for 60 seconds. This study confirmed that a triple iontophoretic treatment of gentamicin for only 60 seconds (0.5mA) significantly reduces the count of pseudomonas in the infected cornea to a non-infectious level. Peak gentamicin concentrations at the healthy corneas (363.1 +/- 127.3 μg/g) and at the aqueous humor (29.4 +/- 17.4 μg/ml) were reached immediately and two hours after a single iontophoretic treatment, respectively. The concentration versus time profile of gentamicin following iontophoresis revealed a gentamicin half life of 2.07 h in the anterior chamber, and a clearance of 1.73 μl/min from the anterior chamber to the posterior segments of the eye. This study indicates that a short iontophoretic treatment using gentamicin-loaded hydrogels has a potential clinical value in treating corneal infections, by increasing drug penetration to the eye and maintaining therapeutic levels for more than eight hours.

The presence of in-house attending trauma surgeons does not improve management or outcome of critically injured patients.

PubMed

Helling, Thomas S; Nelson, Paul W; Shook, John W; Lainhart, Kathy; Kintigh, Denise

2003-07-01

The presence of a surgeon at the initial assessment and care of the trauma patient has been the focal point of trauma center designation. However, for Level I verification, the American College of Surgeons Committee on Trauma currently does not require the presence of an attending trauma surgeon in the hospital (IH), provided senior surgical residents are immediately available. Likewise, the state of Missouri does not mandate an IH presence of the attending trauma surgeon but requires senior (postgraduate year 4 or 5) level surgical residents to immediately respond, with a 20-minute response time mandated for the attending surgeon if IH or out of the hospital (OH). Nevertheless, some claim that IH coverage by attending surgeons provides better care for seriously injured patients. This retrospective study assessed patient care parameters over the past 10 years on critically injured patients to detect any difference in outcome whether the surgeon was IH or OH at the time of the trauma team activation (cardiopulmonary instability, Glasgow Coma Scale [GCS] score < 9, penetrating truncal injury). Patients were subcategorized into blunt/penetrating, shock (systolic blood pressure < 90 mm Hg) on arrival, GCS score < 9, Injury Severity Score (ISS) > 15, or ISS > 25. Response was examined from 8 am to 6 pm weekdays (IH) or 6 pm to 8 am weekdays and all weekends (OH). Patient care parameters examined were mortality, complications, time in the emergency department, time to the operating room, time to computed tomographic scanning, intensive care unit length of stay (LOS), and hospital LOS. For all patients (n = 766), there was no significant difference in any parameters except intensive care unit LOS (IH, 4.90 +/- 7.96 days; OH, 3.58 +/- 7.69 days; p < 0.05). For blunt trauma (n = 369), emergency department time was shorter (99.71 +/- 88.26 minutes vs. 126.51 +/- 96.68 minutes, p < 0.01) and hospital LOS was shorter (8.04 +/- 1.02 days vs. 11.08 +/- 1.15 days, p < 0.05) for OH response. For penetrating trauma (n = 377), shock (n = 187), GCS score < 9 (n = 248), ISS > 15 (n = 363), and ISS > 25 (n = 230), there were no statistically significant differences in any patient care parameter between IH and OH response. For those in most need of urgent operation-penetrating injuries and shock-there were no differences in time to operating room or mortality for OH or IH response. As long as initial assessment and care is provided by senior level IH surgical residents and as long as the attending surgeon responds in a defined period of time (if OH) to guide critical decision-making, the IH presence of an attending surgeon has not been shown in this retrospective study to improve care of the critically injured patient.

On the Loop Current Penetration into the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Weisberg, Robert H.; Liu, Yonggang

2017-12-01

The Gulf of Mexico Loop Current generally intrudes some distance into the Gulf of Mexico before shedding an anticyclonic eddy and retreating back to its more direct entry to exit pathway. The control of this aperiodic process remains only partially known. Here we describe the evolution of the Loop Current throughout the era of satellite altimetry, and offer a mechanistic hypothesis on Loop Current intrusion. As a complement to the known effects of Loop Current forcing on the west Florida shelf circulation, we argue that the west Florida shelf, in turn, impacts the Loop Current evolution. A Self-Organizing Map analysis shows that anomalous northward penetrations of the Loop Current into the Gulf of Mexico occur when the eastern side of Loop Current is positioned west from the southwest corner of the west Florida shelf, whereas the more direct inflow to outflow route occurs when the eastern side of the Loop Current comes in contact with the southwest corner of the west Florida shelf. In essence, we argue that the west Florida shelf anchors the Loop Current in its direct path configuration and that farther northward penetration into the Gulf of Mexico occurs when such anchoring is released. To test of this hypothesis heuristically, we estimate that the dissipation and buoyancy work due to known Loop Current forcing of the west Florida shelf circulation (when in contact with the southwest corner) may exceed the pressure work required for the Loop Current to advance against the ambient Gulf of Mexico fluid.