Open-Ended Coaxial Dielectric Probe Effective Penetration Depth Determination.

PubMed

Meaney, Paul M; Gregory, Andrew P; Seppälä, Jan; Lahtinen, Tapani

2016-03-01

We have performed a series of experiments which demonstrate the effect of open-ended coaxial diameter on the depth of penetration. We used a two layer configuration of a liquid and movable cylindrical piece of either Teflon or acrylic. The technique accurately demonstrates the depth in a sample for which a given probe diameter provides a reasonable measure of the bulk dielectric properties for a heterogeneous volume. In addition we have developed a technique for determining the effective depth for a given probe diameter size. Using a set of simulations mimicking four 50 Ω coaxial cable diameters, we demonstrate that the penetration depth in both water and saline has a clear dependence on probe diameter but is remarkably uniform over frequency and with respect to the intervening liquid permittivity. Two different 50 Ω commercial probes were similarly tested and confirm these observations. This result has significant implications to a range of dielectric measurements, most notably in the area of tissue property studies.

Open-Ended Coaxial Dielectric Probe Effective Penetration Depth Determination

PubMed Central

Meaney, Paul M.; Gregory, Andrew P.; Seppälä, Jan; Lahtinen, Tapani

2016-01-01

We have performed a series of experiments which demonstrate the effect of open-ended coaxial diameter on the depth of penetration. We used a two layer configuration of a liquid and movable cylindrical piece of either Teflon or acrylic. The technique accurately demonstrates the depth in a sample for which a given probe diameter provides a reasonable measure of the bulk dielectric properties for a heterogeneous volume. In addition we have developed a technique for determining the effective depth for a given probe diameter size. Using a set of simulations mimicking four 50 Ω coaxial cable diameters, we demonstrate that the penetration depth in both water and saline has a clear dependence on probe diameter but is remarkably uniform over frequency and with respect to the intervening liquid permittivity. Two different 50 Ω commercial probes were similarly tested and confirm these observations. This result has significant implications to a range of dielectric measurements, most notably in the area of tissue property studies. PMID:27346890

Repair, Evaluation, Maintenance, and Rehabilitation Research Program: Evaluation of Civil Works Metal Structures

DTIC Science & Technology

1991-01-01

can be per- formed at any time, as a spot check, or periodically. Liauid Penetrant Inspection (PT) 19. Aplication . Liquid penetrant testing (PT) is a...increases the inspection \\MAGNE TIC PARTICLESiA - CRACK- Figure 6. Crack in bar magnet attracting magnetic particles 14 particle mobility and enables the...923-9800 or (312) 474-5860 Service: IA, IL, IN, MI, WI LOUISIANA O.S.I. Mobile Lab, Inc. X-Ray Inspection, Inc. P. 0. Box 395 P. 0. Box 51651 Harvey

Effect of heat treatment of wood on the morphology, surface roughness and penetration of simulated and human blood.

PubMed

Rekola, J; Lassila, L V J; Nganga, S; Ylä-Soininmäki, A; Fleming, G J P; Grenman, R; Aho, A J; Vallittu, P K

2014-01-01

Wood has been used as a model material for the development of novel fiber-reinforced composite bone substitute biomaterials. In previous studies heat treatment of wood was perceived to significantly increase the osteoconductivity of implanted wood material. The objective of this study was to examine some of the changing attributes of wood materials that may contribute to improved biological responses gained with heat treatment. Untreated and 140°C and 200°C heat-treated downy birch (Betula pubescens Ehrh.) were used as the wood materials. Surface roughness and the effect of pre-measurement grinding were measured with contact and non-contact profilometry. Liquid interaction was assessed with a dipping test using two manufactured liquids (simulated blood) as well as human blood. SEM was used to visualize possible heat treatment-induced changes in the hierarchical structure of wood. The surface roughness was observed to significantly decrease with heat treatment. Grinding methods had more influence on the surface contour and roughness than heat treatment. The penetration of the human blood in the 200°C heat-treated exceeded that in the untreated and 140°C heat-treated materials. SEM showed no significant change due to heat treatment in the dry-state morphology of the wood. The results of the liquid penetration test support previous findings in literature concerning the effects of heat treatment on the biological response to implanted wood. Heat-treatment has only a marginal effect on the surface contour of wood. The highly specialized liquid conveyance system of wood may serve as a biomimetic model for the further development of tailored fiber-composite materials.

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

Smegal, J.; Lstiburek, J.

There is an increasing market in liquid (or fluid) applied water management barriers for residential applications that could be used in place of tapes and other self-adhering membranes if applied correctly, especially around penetrations in the enclosure. This report discusses current best practices, recommends ways in which the best practices can be improved, and looks at some current laboratory testing and testing standards.

Predicting drug penetration across the blood-brain barrier: comparison of micellar liquid chromatography and immobilized artificial membrane liquid chromatography.

PubMed

De Vrieze, Mike; Lynen, Frédéric; Chen, Kai; Szucs, Roman; Sandra, Pat

2013-07-01

Several in vitro methods have been tested for their ability to predict drug penetration across the blood-brain barrier (BBB) into the central nervous system (CNS). In this article, the performance of a variety of micellar liquid chromatographic (MLC) methods and immobilized artificial membrane (IAM) liquid chromatographic approaches were compared for a set of 45 solutes. MLC measurements were performed on a C18 column with sodium dodecyl sulfate (SDS), polyoxyethylene (23) lauryl ether (Brij35), or sodium deoxycholate (SDC) as surfactant in the micellar mobile phase. IAM liquid chromatography measurements were performed with Dulbecco's phosphate-buffered saline (DPBS) and methanol as organic modifier in the mobile phase. The corresponding retention and computed descriptor data for each solute were used for construction of models to predict transport across the blood-brain barrier (log BB). All data were correlated with experimental log BB values and the relative performance of the models was studied. SDS-based models proved most suitable for prediction of log BB values, followed closely by a simplified IAM method, in which it could be observed that extrapolation of retention data to 0% modifier in the mobile phase was unnecessary.

Cooperative Activated Transport of Dilute Penetrants in Viscous Molecular and Polymer Liquids

NASA Astrophysics Data System (ADS)

Schweizer, Kenneth; Zhang, Rui

We generalize the force-level Elastically Collective Nonlinear Langevin Equation theory of activated relaxation in one-component supercooled liquids to treat the hopping transport of a dilute penetrant in a dense hard sphere fluid. The new idea is to explicitly account for the coupling between penetrant displacement and a local matrix cage re-arrangement which facilitates its hopping. A temporal casuality condition is employed to self-consistently determine a dimensionless degree of matrix distortion relative to the penetrant jump distance using the dynamic free energy concept. Penetrant diffusion becomes increasingly coupled to the correlated matrix displacements for larger penetrant to matrix particle size ratio (R) and/or attraction strength (physical bonds), but depends weakly on matrix packing fraction. In the absence of attractions, a nearly exponential dependence of penetrant diffusivity on R is predicted in the intermediate range of 0.2

Preclinical pilot study monitoring topical drug penetration and dermal bioavailability of a peptidase inhibitor from different galenic formulations into pig dermis, using cutaneous microdialysis.

PubMed

Quist, S R; Heimburg, A; Bank, U; Mahnkopf, D; Koch, G; Gollnick, H; Täger, M; Ansorge, S

2017-08-01

Cutaneous microdialysis (CM) is an ex vivo technique that allows study of tissue chemistry, including bioavailability of actual tissue concentration of unbound drug in the interstitial fluid of the body. To test the penetration and dermal bioavailability of galenic formulations of the small-molecule IP10.C8, a dual-protease inhibitor of the dipeptidyl peptidase and aminopeptidase families. Using CM, we tested the penetration and dermal bioavailability of IP10.C8 into the dermis and subcutis of pigs, and determined the tissue concentration of IP10.C8 enzymatically, using an enzyme activity assay (substrate Gly-Pro-pNA) and high performance liquid chromatography. Dermal bioavailability was enhanced by using microemulsion or the addition of the penetration enhancer oleic acid to a hydroxyethylcellulose (HEC) gel formulation. Dermal bioavailability was also enhanced when galenic formulations were prepared with higher pH (7.5 vs. 6.5) or higher drug concentration (5% vs. 1%) in HEC gel. It seems possible, using CM for topical skin penetration testing in anaesthetized domestic pigs, to test the bioavailability of newly designed drugs. However, the experimental time is limited due to the anaesthesia, and is dependent on drug recovery. Validation of this technique for routine use is challenging, and more experiments are needed to validate this preclinical set-up. © 2017 British Association of Dermatologists.

Water Management of Noninsulating and Insulating Sheathings

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

Smegal, J.; Lstiburek, J.

2012-04-01

There is an increasing market in liquid (or fluid) applied water management barriers for residential applications that could be used in place of tapes and other self-adhering membranes if applied correctly, especially around penetrations in the enclosure. This report discusses current best practices, recommends ways in which the best practices can be improved, and looks at some current laboratory testing and testing standards.

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.

Pore-scale modeling of Capillary Penetration of Wetting Liquid into 3D Fibrous Media: A Critical Examination of Equivalent Capillary Concept

NASA Astrophysics Data System (ADS)

Palakurthi, Nikhil Kumar; Ghia, Urmila; Comer, Ken

2013-11-01

Capillary penetration of liquid through fibrous porous media is important in many applications such as printing, drug delivery patches, sanitary wipes, and performance fabrics. Historically, capillary transport (with a distinct liquid propagating front) in porous media is modeled using capillary-bundle theory. However, it is not clear if the capillary model (Washburn equation) describes the fluid transport in porous media accurately, as it assumes uniformity of pore sizes in the porous medium. The present work investigates the limitations of the applicability of the capillary model by studying liquid penetration through virtual fibrous media with uniform and non-uniform pore-sizes. For the non-uniform-pore fibrous medium, the effective capillary radius of the fibrous medium was estimated from the pore-size distribution curve. Liquid penetration into the 3D virtual fibrous medium at micro-scale was simulated using OpenFOAM, and the numerical results were compared with the Washburn-equation capillary-model predictions. Preliminary results show that the Washburn equation over-predicts the height rise in the early stages (purely inertial and visco-inertial stages) of capillary transport.

Experimental investigation on consistency limits of cement and lime-stabilized marine sediments.

PubMed

Wang, DongXing; Zentar, Rachid; Abriak, Nor Edine; Xu, WeiYa

2012-06-01

This paper presents the effects of treatments with cement and lime on the consistency limits of marine sediments dredged from Dunkirk port. The Casagrande percussion test and the fall cone test were used to determine the liquid limits of raw sediments and treated marine sediments. For the evaluation of the plastic limits, the results of the fall cone test were compared with those obtained by the rolling test method. The relationship between the water contents and the penetration depths for the determination of the liquid limit and the plastic limit was explored. Liquid limits at 15.5 mm and plastic limits at 1.55 mm seem to be a more appropriate choice for the studied marine sediments compared with the limits determined by other used prediction methods. Finally, the effect of cement treatment and lime treatment on the Casagrande classification of the studied sediments was investigated according to the different prediction results.

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

Adding Endoscopist-Directed Flexible Endoscopic Evaluation of Swallowing to the Videofluoroscopic Swallowing Study Increased the Detection Rates of Penetration, Aspiration, and Pharyngeal Residue.

PubMed

Park, Won Young; Lee, Tae Hee; Ham, Nam Seok; Park, Ji Woong; Lee, Yang Gyun; Cho, Sang Jin; Lee, Joon Seong; Hong, Su Jin; Jeon, Seong Ran; Kim, Hyun Gun; Cho, Joo Young; Kim, Jin Oh; Cho, Jun Hyung; Lee, Ji Sung

2015-09-23

Currently, the videofluoroscopic swallowing study (VFSS) is the standard tool for evaluating dysphagia. We evaluated whether the addition of endoscopist-directed flexible endoscopic evaluation of swallowing (FEES) to VFSS could improve the detection rates of penetration, aspiration, and pharyngeal residue, compared the diagnostic efficacy between VFSS and endoscopist-directed FEES and assessed the adverse events of the FEES. In single tertiary referral center, a retrospective analysis of prospectively collected data was conducted. Fifty consecutive patients suspected of oropharyngeal dysphagia were enrolled in this study between January 2012 and July 2012. The agreement in the detection of penetration and aspiration between VFSS and FEES of viscous food (κ=0.34; 95% confidence interval [CI], 0.15 to 0.53) and liquid food (κ=0.22; 95% CI, 0.02 to 0.42) was "fair." The agreement in the detection of pharyngeal residue between the two tests was "substantial" with viscous food (κ=0.63; 95% CI, 0.41 to 0.94) and "fair" with liquid food (κ=0.37; 95% CI, 0.10 to 0.63). Adding FEES to VFSS significantly increased the detection rates of penetration, aspiration, and pharyngeal residue. No severe adverse events were noted during FEES, except for two cases of epistaxis, which stopped spontaneously without requiring any packing. This study demonstrated that the addition of endoscopist-directed FEES to VFSS increased the detection rates of penetration, aspiration, and pharyngeal residue.

Detecting Aspiration and Penetration Using FEES With and Without Food Dye.

PubMed

Marvin, Stevie; Gustafson, Sara; Thibeault, Susan

2016-08-01

The objective of this investigation was to determine if there were differences in identifying airway invasion (penetration or aspiration) during fiberoptic endoscopic evaluations of swallowing (FEES) for green-dyed versus non-dyed liquids. Forty adult inpatients in an acute care hospital underwent FEES, with both green-dyed liquids and naturally white liquids. Three speech-language pathologists rated aspiration and penetration for trials of nectar-thick milk and thin milk, both with and without green food dye. A subset of participants having excess pharyngeal/laryngeal secretions, as measured by the Secretions Severity Scale, were also analyzed for a difference in the detection of airway invasion and pharyngeal residue. No significant differences were found between dyes in airway invasion across all bolus types within participants. Significant differences were found in penetration ratings for large volumes of thin liquids (90 ml), between participants. When examining only discrepant airway invasion judgments for green-white swallow pairs, statistically significantly deeper airway invasion was measured for green-dyed boluses versus white for three of the five bolus types. Repeat rater reliability was better for dyed versus undyed liquids. Findings suggest that the use of green dye may allow for improved judgment of airway invasion.

Characterization of a Heated Liquid Jet in Crossflow

NASA Astrophysics Data System (ADS)

Wiest, Heather K.

The liquid jet in crossflow (LJICF) is a widely utilized fuel injection method for airbreathing propulsion devices such as low NO x gas turbine combustors, turbojet afterburners, scramjet/ramjet engines, and rotating detonation engines (RDE's). This flow field allows for efficient fuel-air mixing as aerodynamic forces from the crossflow augment atomization. Additionally, increases in the thermal demands of advanced aeroengines necessitates the use of fuel as a primary coolant. The resulting higher fuel temperatures can cause flash atomization of the liquid fuel as it is injected into a crossflow, potentially leading to a large reduction in the jet penetration. While many experimental works have characterized the overall atomization process of a room temperature liquid jet in an ambient temperature and pressure crossflow, the aggressive conditions associated with flash atomization especially in an air crossflow with elevated temperatures and pressures have been less studied in the community. A successful test campaign was conducted to study the effects of fuel temperature on a liquid jet injected transversely into a steady air crossflow at ambient as well as elevated temperature and pressure conditions. Modifications were made to an existing optically accessible rig, and a new fuel injector was designed for this study. Backlit imaging was utilized to record changes in the overall spray characteristics and jet trajectory as fuel temperature and crossflow conditioners were adjusted. Three primary analysis techniques were applied to the heated LJICF data: linear regression of detected edges to determine trajectory correlations, exploratory study of pixel intensity variations both temporally as well as spatially, and modal decomposition of the data. The overall objectives of this study was to assess the trajectory, breakup, and mixing of the LJICF undery varying jet and crossflow conditions, develop a trajectory correlation to predict changes in jet penetration due to fuel temperature increases, and characterize the changes in underlying physics in the LJICF flow field. Based on visual inspection, the increase in fuel temperature leads to a finer and denser fuel spray. With increasingly elevated liquid temperatures, the penetration of the jet typically decreases. At or near flashing conditions, the jet had a tendency to penetrate upstream before bending over in the crossflow as well as experiences a rapid expansion causing the jet column to increase in width. Two trajectory correlations were determined, one for each set of crossflow conditions, based on normalized axial distance, normalized liquid viscosity, and normalized jet diameter as liquid is vaporized. The pixel intensity analysis showed that the highest temperature jet in the ambient temperature and pressure crossflow exhibited periodic behavior that was also found using various modal techniques including proper orthogonal decomposition and dynamic mode decomposition. Dominant frequencies determined for most test cases were associated with the bulk or flapping motion of the jet. Most notably, the DMD analysis in this study was successful in identifying robust modes across different subgroupings of the data even though the modes identified were not the highest power modes in each DMD spectrum.

Analysis of carbonated thin liquids in pediatric neurogenic dysphagia

PubMed Central

Lundine, Jennifer P.; Bates, David G.; Yin, Han

2015-01-01

Background Aspiration of liquids is a serious complication of neurological impairments such as traumatic brain injury or stroke. Carbonated liquids have been examined as a possible alternative to thickened liquids to help reduce aspiration in cases of dysphagia in adults, but no published literature to the best of our knowledge has evaluated this technique in children. If carbonated liquids result in safer swallowing in children, they could provide a preferred alternative to thickened liquids. Objective This pilot study examined whether carbonated thin liquids (CARB) improved swallowing compared to noncarbonated thin liquids (NOCARB) for children with neurogenic dysphagia. Materials and methods Twenty-four children admitted to a level I trauma center for acute neurological injury/disease were evaluated via videofluoroscopic swallow studies. Four descriptive outcome measures were contrasted. Results CARB significantly decreased pooling (P=0.0006), laryngeal penetration/aspiration (P=0.0044) and Penetration-Aspiration Scale scores (P=0.0127) when compared to NOCARB. On average, CARB improved scores on the Penetration-Aspiration Scale by 3.7 points for participants who aspirated NOCARB. There was no significant difference in pharyngeal residue noted between CARB and NOCARB (P=0.0625). Conclusion These findings support the hypothesis that carbonated thin liquids may provide an alternative to thickened liquids for children with neurogenic dysphagia. Implications for future research and clinical practice are discussed. PMID:25758792

Contamination of liquid oxygen by pressurized gaseous nitrogen

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J.; King, Tracy K.; Ngo, Kim Chi

1989-01-01

The penetration of pressurized gaseous nitrogen (GN2) into liquid oxygen (LOX) was investigated experimentally in the 7-inch High Temperature Tunnel, the pilot tunnel for the 8-foot High Temperature Tunnel (8'HTT) at Langley Research Center. A preliminary test using a nuclear monitor revealed the extent of the liquid nitrogen (LN2) build-up at the LOX interface as a function of GN2 pressure. Then an adaptation of the differential flash vaporization technique was used to determine the binary diffusivity of the LOX-LN2 system at a temperature of 90.2 K. The measured value D equals 0.000086 sq cm/s + or - 25 percent together with two prior measurements at lower temperatures revealed an excellent fit to the Arrhenius equation, yielding a pre-exponential factor D sub 0 equals 0.0452 sq cm/s and an activation enthalpy H equals 1.08 kcal/mol. At a pressure of 1700 psi and holding time of 15 min, the penetration of LN2 into LOX (to a 1 percent contamination level) was found to be 0.9 cm, indicating but minimal impact upon 8'HTT operations.

NDE: An effective approach to improved reliability and safety. A technology survey. [nondestructive testing of aircraft structures

NASA Technical Reports Server (NTRS)

Carpenter, J. L., Jr.; Stuhrke, W. F.

1976-01-01

Technical abstracts are presented for about 100 significant documents relating to nondestructive testing of aircraft structures or related structural testing and the reliability of the more commonly used evaluation methods. Particular attention is directed toward acoustic emission; liquid penetrant; magnetic particle; ultrasonics; eddy current; and radiography. The introduction of the report includes an overview of the state-of-the-art represented in the documents that have been abstracted.

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.

Heat Loads Due to Small Penetrations in Multilayer Insulation Blankets

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Heckle, K. W.; Fesmire, J. E.

2017-01-01

The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to each the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fouriers Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at 76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

Heat Loads Due To Small Penetrations In Multilayer Insulation Blankets

NASA Astrophysics Data System (ADS)

Johnson, W. L.; Heckle, K. W.; E Fesmire, J.

2017-12-01

The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to ease the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fourier’s Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at ∼76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

Melting probes revisited - Ice penetration experiments under Mars surface pressure conditions

NASA Astrophysics Data System (ADS)

Kömle, Norbert I.; Tiefenbacher, Patrick; Weiss, Peter; Bendiukova, Anastasiia

2018-07-01

Melting probes as vehicles to explore terrestrial ice sheets have been designed and applied successfully since the early 1960's. Later on, in the 1990's, various proposals were made to apply such probes also as a means to explore ice sheets on other bodies of the solar system, e.g. Jupiter's icy satellite Europa or the ice caps of Mars. For this type of subsurface probes the name cryobot has become common. We review both early developments and more recent efforts to develop probes for application in planetary environments, i.e. under low pressures and low temperatures. The current state of art as well as the pros and cons of the different concepts hitherto considered are described. While many tests with various probes have been done in terrestrial environments, experiments under low surface pressure conditions are rare. Therefore, we report here on lab tests with a simple melting probe under the range of pressure and temperature conditions that would be encountered on the surface of Mars and compare them with corresponding tests under a much lower gas pressure, possibly representative for icy satellites. The contribution of evaporation during the melting and its variation with surface pressure is also considered. All surface pressure measurements that have been performed on Mars up to now indicate a surface pressure above the water triple point pressure (612 Pa). This means that water ice always transforms into the liquid phase when warmed up to 0°C, before it evaporates into the ambient atmosphere. The temporary existence of the liquid phase around the heated tip of the cryobot allows good thermal conductance between probe and surrounding ice, which is an important pre-requisite for efficient melt penetration. Our experiments indicate that under all possible Mars surface pressures the liquid phase is present when the probe is heated up. This finding confirms experimentally that a probe as it was proposed by Paige (1992) for in situ exploration of the Mars north polar layers would work in the expected way, although the penetration velocity must be expected be lower than under Earth pressure conditions. A test with the same probe, but under an almost two orders of magnitude lower gas pressure than on Mars, still indicates the temporary existence of the liquid phase in the contact region between the probe and the surrounding ice.

FRACTIONAL PENETRATION OF PAINT OVERSPRAY ARRESTORS

EPA Science Inventory

The report describes the development of fractional penetration curves for liquid droplet penetration of overspray arrestors for discrete droplet diameters from 0.3 to 10 micrometers. (NOTE: Fine particulates are particles with diameters of 10 micrometers or less.) These data poin...

Numerical investigation of the interaction of positive streamers with bubbles floating on a liquid surface

NASA Astrophysics Data System (ADS)

Babaeva, Natalia Yu.; Naidis, George V.; Kushner, Mark J.

2016-09-01

Streamer discharges in air intersecting with liquids are being investigated to produce reactivity in the liquid. In this talk, we discuss results from a 2-d computational investigation of streamers in air intersecting an isolated liquid, air filled bubble floating on a liquid surface. The 15 mm diameter bubble is conducting water (ɛ /ɛ0 = 80 , σ = 7 . 5 ×10-4Ω-1cm-1) or transformer oil (ɛ /ɛ0 = 2 . 2 , σ = 1 . 5 ×10-13Ω-1cm-1). A needle electrode is positioned d =0-10 mm from the bubble center. With a water bubble (d =0) the streamer slides along the external surface but does not penetrate the bubble due to electric field screening by the conducting shell. If the electrode is shifted (d =3-10 mm) the streamer deviates from the vertical and adheres to the bubble. If the electrode is inserted inside the bubble, the streamer path depends on how deep the electrode penetrates. For shallow penetration, the streamer propagates along the inner surface of the bubble. For deep penetration the streamer takes the shortest path down through the gas. Due to the low conductivity of the oil bubble shell the electric field penetrates into the interior of the bubble. The streamer can then be re-initiated inside the bubble. Charge accumulation on both sides of the bubble shell and perforation of the shell will be also discussed. NYB, GVN supported by Russian Sci. Found. (14-12-01295). MJK by US Natl. Sci. Found. and Dept. of Energy.

Theory of activated penetrant diffusion in viscous fluids and colloidal suspensions

NASA Astrophysics Data System (ADS)

Zhang, Rui; Schweizer, Kenneth S.

2015-10-01

We heuristically formulate a microscopic, force level, self-consistent nonlinear Langevin equation theory for activated barrier hopping and non-hydrodynamic diffusion of a hard sphere penetrant in very dense hard sphere fluid matrices. Penetrant dynamics is controlled by a rich competition between force relaxation due to penetrant self-motion and collective matrix structural (alpha) relaxation. In the absence of penetrant-matrix attraction, three activated dynamical regimes are predicted as a function of penetrant-matrix size ratio which are physically distinguished by penetrant jump distance and the nature of matrix motion required to facilitate its hopping. The penetrant diffusion constant decreases the fastest with size ratio for relatively small penetrants where the matrix effectively acts as a vibrating amorphous solid. Increasing penetrant-matrix attraction strength reduces penetrant diffusivity due to physical bonding. For size ratios approaching unity, a distinct dynamical regime emerges associated with strong slaving of penetrant hopping to matrix structural relaxation. A crossover regime at intermediate penetrant-matrix size ratio connects the two limiting behaviors for hard penetrants, but essentially disappears if there are strong attractions with the matrix. Activated penetrant diffusivity decreases strongly with matrix volume fraction in a manner that intensifies as the size ratio increases. We propose and implement a quasi-universal approach for activated diffusion of a rigid atomic/molecular penetrant in a supercooled liquid based on a mapping between the hard sphere system and thermal liquids. Calculations for specific systems agree reasonably well with experiments over a wide range of temperature, covering more than 10 orders of magnitude of variation of the penetrant diffusion constant.

Theory of activated penetrant diffusion in viscous fluids and colloidal suspensions

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

Zhang, Rui; Schweizer, Kenneth S., E-mail: kschweiz@illinois.edu

2015-10-14

We heuristically formulate a microscopic, force level, self-consistent nonlinear Langevin equation theory for activated barrier hopping and non-hydrodynamic diffusion of a hard sphere penetrant in very dense hard sphere fluid matrices. Penetrant dynamics is controlled by a rich competition between force relaxation due to penetrant self-motion and collective matrix structural (alpha) relaxation. In the absence of penetrant-matrix attraction, three activated dynamical regimes are predicted as a function of penetrant-matrix size ratio which are physically distinguished by penetrant jump distance and the nature of matrix motion required to facilitate its hopping. The penetrant diffusion constant decreases the fastest with size ratiomore » for relatively small penetrants where the matrix effectively acts as a vibrating amorphous solid. Increasing penetrant-matrix attraction strength reduces penetrant diffusivity due to physical bonding. For size ratios approaching unity, a distinct dynamical regime emerges associated with strong slaving of penetrant hopping to matrix structural relaxation. A crossover regime at intermediate penetrant-matrix size ratio connects the two limiting behaviors for hard penetrants, but essentially disappears if there are strong attractions with the matrix. Activated penetrant diffusivity decreases strongly with matrix volume fraction in a manner that intensifies as the size ratio increases. We propose and implement a quasi-universal approach for activated diffusion of a rigid atomic/molecular penetrant in a supercooled liquid based on a mapping between the hard sphere system and thermal liquids. Calculations for specific systems agree reasonably well with experiments over a wide range of temperature, covering more than 10 orders of magnitude of variation of the penetrant diffusion constant.« less

Physical and Mechanical Properties of W-Ni-Fe-Co Metal Foam Modified by Titanium Tungsten Carbide Alloying

NASA Astrophysics Data System (ADS)

Ishchenko, A. N.; Tabachenko, A. N.; Afanas'eva, S. A.; Belov, N. N.; Biryukov, Yu. A.; Burkin, V. V.; D'yachkovskii, A. S.; Rogaev, K. S.; Skosyrskii, A. B.; Yugov, N. T.

2018-02-01

The paper studies physical and mechanical properties of tungsten-nickel-iron-cobalt metal foam alloyed with titanium tungsten carbide. Test specimens are obtained by the liquid phase sintering of powder materials, including those containing tungsten nanopowders. High porosity metal foams are prepared through varying the porosity of powder specimens and the content of filling material. The penetration capability of cylinder projectiles made of new alloys is explored in this paper. It is shown that their penetration depth exceeds that of the prototype with relevant weight and size, made of tungsten-nickel-iron alloy, other factors being equal.

Solar space heating system at the Seeley G. Mudd Education Building, Pacific School of Religion, 1798 Scenic Avenue, Berkeley California 94708. Final report

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

Not Available

Large areas of south facing glass allow winter sunlight to penetrate the building, while overhangs provide summer shading. High ceilings allow deep penetration of this light for space heating and natural lighting. Massive construction stores solar radiation for evening warmth and provides a buffer from extreme temperature fluctuations. Natural ventilation will provide cooling. The system consists of 720 square feet of roof-mounted, liquid, flat plate solar collectors and three 350 gallon fiberglass storage tanks. The acceptance and performance tests are discussed. Also discusseed are: collector selection, construction contract, costs, and economics.

Self-Assembled Cubic Liquid Crystalline Nanoparticles for Transdermal Delivery of Paeonol

PubMed Central

Li, Jian-Chun; Zhu, Na; Zhu, Jin-Xiu; Zhang, Wen-Jing; Zhang, Hong-Min; Wang, Qing-Qing; Wu, Xiao-Xiang; Wang, Xiu; Zhang, Jin; Hao, Ji-Fu

2015-01-01

Background The aim of this study was to optimize the preparation method for self-assembled glyceryl monoolein-based cubosomes containing paeonol and to characterize the properties of this transdermal delivery system to improve the drug penetration ability in the skin. Material/Methods In this study, the cubic liquid crystalline nanoparticles loaded with paeonol were prepared by fragmentation of glyceryl monoolein (GMO)/poloxamer 407 bulk cubic gel by high-pressure homogenization. We evaluated the Zeta potential of these promising skin-targeting drug-delivery systems using the Malvern Zeta sizer examination, and various microscopies and differential scanning calorimetry were also used for property investigation. Stimulating studies were evaluated based on the skin irritation reaction score standard and the skin stimulus intensity evaluation standard for paeonol cubosomes when compared with commercial paeonol ointment. In vitro tests were performed on excised rat skins in an improved Franz diffusion apparatus. The amount of paeonol over time in the in vitro penetration and retention experiments both was determined quantitatively by HPLC. Results Stimulating studies were compared with the commercial ointment which indicated that the paeonol cubic liquid crystalline nanoparticles could reduce the irritation in the skin stimulating test. Thus, based on the attractive characteristics of the cubic crystal system of paeonol, we will further exploit the cosmetic features in the future studies. Conclusions The transdermal delivery system of paeonol with low-irritation based on the self-assembled cubic liquid crystalline nanoparticles prepared in this study might be a promising system of good tropical preparation for skin application. PMID:26517086

An application of digital image processing techniques to the characterization of liquid petroleum gas (LPG) spray

NASA Astrophysics Data System (ADS)

Qi, Y. L.; Xu, B. Y.; Cai, S. L.

2006-12-01

To control fuel injection, optimize combustion and reduce emissions for LPG (liquefied petroleum gas) engines, it is necessary and important to understand the characteristics of LPG sprays. The present work investigates the geometry of LPG sprays, including spray tip penetration, spray angle, projected spray area and spray volume, by using schlieren photography and digital image processing techniques. Two types of single nozzle injectors were studied, with the same nozzle diameter, but one with and one without a double-hole flow-split head. A code developed to analyse the results directly from the digitized images is shown to be more accurate and efficient than manual measurement and analysis. Test results show that a higher injection pressure produces a longer spray tip penetration, a larger projected spray area and spray volume, but a smaller spray cone angle. The injector with the double-hole split-head nozzle produces better atomization and shorter tip penetration at medium and late injection times, but longer tip penetration in the early stage.

Penetration and blown-air effect in sand

NASA Astrophysics Data System (ADS)

Clement, R.; Courrech du Pont, S.; Douady, S.

2012-04-01

Sand is known to show a variety of uncommon physical features that do not fit the behavior of liquid or solid state. A good example of the inherent difficulties encountered when trying to describe collective grains behavior is the penetration of an intruding object into a granular medium. Such problems involve large coordination numbers, and the medium response dramatically depends on the volume fraction. On the fringe of these studies, we consider here the penetration of a cylindrical shell (typically an upside down glass) into dry sand, and report what we called the "blown-air effect". The air initially trapped escapes when the shell is pushed into sand, flowing through the granular medium. This flow dilates the sand and considerably eases the penetration of the shell. This is very different from what happens in liquids: when pushing a top-closed shell into a liquid, the trapped air increases the buoyancy and opposes the penetration. We show that the air flow does not change the general dynamics of penetration, suggesting that fluidization only involves an effective smaller volume fraction. Despite its simplicity (only a glass and some sand are needed to observe the effect), this experiment nicely illustrates the sometimes counter-intuitive behavior of granular media. Penetration in sand is also a critical issue in industry, and this work may help improving burying methods. Ref: Penetration and blown air effect in granular media R. Clément, S. Courrech du Pont, M. Ould-Hamouda, D. Duveau, and S. Douady Phys. Rev. Lett. 2011 Science News: http://news.sciencemag.org/sciencenow/2011/02/convince-your-friends-youre-a-ge.html

Modular detector for deep underwater registration of muons and muon groups

NASA Technical Reports Server (NTRS)

Demianov, A. I.; Sarycheva, L. I.; Sinyov, N. B.; Varadanyan, I. N.; Yershov, A. A.

1985-01-01

Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences.

Atomization of liquids in a Pease-Anthony Venturi scrubber. Part I. Jet dynamics.

PubMed

Gonçalves, J A S; Costa, M A M; Henrique, P R; Coury, J R

2003-02-28

Jet dynamics, in particular jet penetration, is an important design parameter affecting the collection efficiency of Venturi scrubbers. A mathematical description of the trajectory, break-up and penetration of liquid jets initially transversal to a subsonic gas stream is presented. Experimental data obtained from a laboratory scale Venturi scrubber, operated with liquid injected into the throat through a single orifice, jet velocities between 6.07 and 15.9 m/s, and throat gas velocities between 58.3 and 74.9 m/s, is presented and used to validate the model.

Acoustic analysis of swallowing sounds: a new technique for assessing dysphagia.

PubMed

Santamato, Andrea; Panza, Francesco; Solfrizzi, Vincenzo; Russo, Anna; Frisardi, Vincenza; Megna, Marisa; Ranieri, Maurizio; Fiore, Pietro

2009-07-01

To perform acoustic analysis of swallowing sounds, using a microphone and a notebook computer system, in healthy subjects and patients with dysphagia affected by neurological diseases, testing the positive/negative predictive value of a pathological pattern of swallowing sounds for penetration/aspiration. Diagnostic test study, prospective, not blinded, with the penetration/aspiration evaluated by fibreoptic endoscopy of swallowing as criterion standard. Data from a previously recorded database of normal swallowing sounds for 60 healthy subjects according to gender, age, and bolus consistency was compared with those of 15 patients with dysphagia from a university hospital referral centre who were affected by various neurological diseases. Mean duration of the swallowing sounds and post-swallowing apnoea were recorded. Penetration/aspiration was verified by fibreoptic endoscopy of swallowing in all patients with dysphagia. The mean duration of swallowing sounds for a liquid bolus of 10 ml water was significantly different between patients with dysphagia and healthy patients. We also described patterns of swallowing sounds and tested the negative/positive predictive values of post-swallowing apnoea for penetration/aspiration verified by fibreoptic endoscopy of swallowing (sensitivity 0.67 (95% confidence interval 0.24-0.94); specificity 1.00 (95% confidence interval 0.56-1.00)). The proposed technique for recording and measuring swallowing sounds could be incorporated into the bedside evaluation, but it should not replace the use of more diagnostic and valuable measures.

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.

Determination of silver in personal care nanoproducts and effects on dermal exposure

NASA Astrophysics Data System (ADS)

Wasukan, Nootcharin; Srisung, Sujittra; Kulthong, Kornphimol; Boonrungsiman, Suwimon; Maniratanachote, Rawiwan

2015-11-01

Silver (Ag) is one of the widely used nanomaterials in cosmetics, personal care, and household products. This research aimed to investigate the Ag concentration contained in 20 commercial nanoproducts using a simple and reliable procedure. The exposure and adverse effects of a single topical application of Ag on the skin were also evaluated. Herein, we demonstrated that the technique of wet acid digestion, extraction and detection of Ag with graphite furnace absorption spectrometry were effective for any and all nanoproduct matrices. The Ag morphology was characterized by scanning and transmission electron microscopy equipped with energy-dispersive x-ray spectroscopy. Penetration of Ag was evaluated using a polyethersulfone (PES) membrane through a Franz cell and reconstructed human epidermis (RhE) tissue. A skin irritation test was performed on RhE, an acceptable in vitro model which was in compliance with OECD test guideline 439. The results showed that the initial Ag concentration in the tested nanoproducts ranged between 0.0058 and 94 µg/g. However, particulate Ag was only found in two products, both of a liquid formulation. Silver penetration through a PES membrane (0.12-53 % by weight) was weakly correlated with the initial Ag concentration in each sample, but more so to the product formulation. The liquid products demonstrated the highest percent of average Ag penetration, followed by the semi-solid and solid formulations, respectively. In contrast, neither any Ag diffusion from these products into the RhE tissue nor any irritation or toxicity was detected. This study suggests a screening method to evaluate the Ag level in products and their potential adverse effects on the skin that could be incorporated as a part of risk assessment for nanotechnology products.

Bonded and Sealed External Insulations for Liquid-Hydrogen-Fueled Rocket Tanks During Atmospheric Flight

NASA Technical Reports Server (NTRS)

Gray, V. H.; Gelder, T. F.; Cochran, R. P.; Goodykoontz, J. H.

1960-01-01

Several currently available nonmetallic insulation materials that may be bonded onto liquid-hydrogen tanks and sealed against air penetration into the insulation have been investigated for application to rockets and spacecraft. Experimental data were obtained on the thermal conductivities of various materials in the cryogenic temperature range, as well as on the structural integrity and ablation characteristics of these materials at high temperatures occasioned by aerodynamic heating during atmospheric escape. Of the materials tested, commercial corkboard has the best overall properties for the specific requirements imposed during atmospheric flight of a high-acceleration rocket vehicle.

Lightweight, Low-CTE Tubes Made From Biaxially Oriented LCPs

NASA Technical Reports Server (NTRS)

Rubin, Leslie; Federico, Frank; Formato, Richard; Larouco, John; Slager, William

2004-01-01

Tubes made from biaxially oriented liquid-crystal polymers (LCPs) have been developed for use as penetrations on cryogenic tanks. ( Penetrations in this context denotes feed lines, vent lines, and sensor tubes, all of which contribute to the undesired conduction of heat into the tanks.) In comparison with corresponding prior cryogenic-tank penetrations made from stainless steels and nickel alloys, the LCP penetrations offer advantages of less weight and less thermal conduction. An additional major advantage of LCP components is that one can tailor their coefficients of thermal expansion (CTEs). The estimated cost of continuous production of LCP tubes of typical sizes is about $1.27/ft ($4.17/m) [based on 1998 prices]. LCP tubes that are compatible with liquid oxygen and that feature tailored biaxial molecular orientation and quasi-isotropic properties (including quasi-isotropic CTE) have been fabricated by a combination of proprietary and patented techniques that involve the use of counterrotating dies (CRDs). Tailoring of the angle of molecular orientation is what makes it possible to tailor the CTE over a wide range to match the CTEs of adjacent penetrations of other tank components; this, in turn, makes it possible to minimize differential-thermal expansion stresses that arise during thermal cycling. The fabrication of biaxially oriented LCP tubes by use of CRDs is not new in itself. The novelty of the present development lies in tailoring the orientations and thus the CTEs and other mechanical properties of the LCPs for the intended cryogenic applications and in modifications of the CRDs for this purpose. The LCP tubes and the 304-stainless-steel tubes that the LCP tubes were intended to supplant were tested with respect to burst strength, permeability, thermal conductivity, and CTE.

Neutron measurements from beam-target reactions at the ELISE neutral beam test facility

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

Xufei, X., E-mail: xiexufei@pku.edu.cn; Fan, T.; Nocente, M.

2014-11-15

Measurements of 2.5 MeV neutron emission from beam-target reactions performed at the ELISE neutral beam test facility are presented in this paper. The measurements are used to study the penetration of a deuterium beam in a copper dump, based on the observation of the time evolution of the neutron counting rate from beam-target reactions with a liquid scintillation detector. A calculation based on a local mixing model of deuterium deposition in the target up to a concentration of 20% at saturation is used to evaluate the expected neutron yield for comparison with data. The results are of relevance to understandmore » neutron emission associated to beam penetration in a solid target, with applications to diagnostic systems for the SPIDER and MITICA Neutral Beam Injection prototypes.« less

Nano-particle dynamics during capillary suction.

PubMed

Kuijpers, C J; Huinink, H P; Tomozeiu, N; Erich, S J F; Adan, O C G

2018-07-01

Due to the increased use of nanoparticles in everyday applications, there is a need for theoretical descriptions of particle transport and attachment in porous media. It should be possible to develop a one dimensional model to describe nanoparticle retention during capillary transport of liquid mixtures in porous media. Water-glycerol-nanoparticle mixtures were prepared and the penetration process in porous Al 2 O 3 samples of varying pore size is measured using NMR imaging. The liquid and particle front can be measured by utilizing T 2 relaxation effects from the paramagnetic nanoparticles. A good agreement between experimental data and the predicted particle retention by the developed theory is found. Using the model, the binding constant for Fe 2 O 3 nanoparticles on sintered Al 2 O 3 samples and the maximum surface coverage are determined. Furthermore, we show that the penetrating liquid front follows a square root of time behavior as predicted by Darcy's law. However, scaling with the liquid parameters is no longer sufficient to map different liquid mixtures onto a single master curve. The Darcy model should be extended to address the two formed domains (with and without particles) and their interaction, to give an accurate prediction for the penetrating liquid front. Copyright © 2018 Elsevier Inc. All rights reserved.

Parallel particle impactor - novel size-selective particle sampler for accurate fractioning of inhalable particles

NASA Astrophysics Data System (ADS)

Trakumas, S.; Salter, E.

2009-02-01

Adverse health effects due to exposure to airborne particles are associated with particle deposition within the human respiratory tract. Particle size, shape, chemical composition, and the individual physiological characteristics of each person determine to what depth inhaled particles may penetrate and deposit within the respiratory tract. Various particle inertial classification devices are available to fractionate airborne particles according to their aerodynamic size to approximate particle penetration through the human respiratory tract. Cyclones are most often used to sample thoracic or respirable fractions of inhaled particles. Extensive studies of different cyclonic samplers have shown, however, that the sampling characteristics of cyclones do not follow the entire selected convention accurately. In the search for a more accurate way to assess worker exposure to different fractions of inhaled dust, a novel sampler comprising several inertial impactors arranged in parallel was designed and tested. The new design includes a number of separated impactors arranged in parallel. Prototypes of respirable and thoracic samplers each comprising four impactors arranged in parallel were manufactured and tested. Results indicated that the prototype samplers followed closely the penetration characteristics for which they were designed. The new samplers were found to perform similarly for liquid and solid test particles; penetration characteristics remained unchanged even after prolonged exposure to coal mine dust at high concentration. The new parallel impactor design can be applied to approximate any monotonically decreasing penetration curve at a selected flow rate. Personal-size samplers that operate at a few L/min as well as area samplers that operate at higher flow rates can be made based on the suggested design. Performance of such samplers can be predicted with high accuracy employing well-established impaction theory.

Corrosion behavior of steels in liquid lead bismuth with low oxygen concentrations

NASA Astrophysics Data System (ADS)

Kurata, Yuji; Futakawa, Masatoshi; Saito, Shigeru

2008-02-01

Corrosion tests in pots were conducted to elucidate corrosion behavior of various steels in liquid lead-bismuth for 3000 h under the condition of an oxygen concentration of 5 × 10 -8 wt% at 450 °C and an oxygen concentration of 3 × 10 -9 wt% at 550 °C, respectively. Significant corrosion was not observed at 450 °C for ferritic/martensitic steels, F82H, Mod.9Cr-1Mo steel, 410SS, 430SS except 2.25Cr-1Mo steel. Pb-Bi penetration into steels and dissolution of elements into Pb-Bi were severe at 550 °C even for ferritic/martensitic steels. Typical dissolution attack occurred for pure iron both at 550 °C without surface Fe 3O 4 and at 450 °C with a thin Fe 3O 4 film. Ferritization due to dissolution of Ni and Cr, and Pb-Bi penetration were recognized for austenitic stainless steels, 316SS and 14Cr-16Ni-2Mo steel at both temperatures of 450 °C and 550 °C. The phenomena were mitigated for 18Cr-20Ni-5Si steel. In some cases oxide films could not be a corrosion barrier in liquid lead-bismuth.

Aircraft Survivability. Spring 2011

DTIC Science & Technology

2011-01-01

test Figure 4 Mixed Lagrangian and SPH Simulation of the Bullet Impacting the Floor Section Figure 5 Predictions of Damage to Penetrator, CMC Layer...aircraft and regulating the flow of liquid to simulate both the intrinsic change in plume intensity and the apparent change in intensity of a simulated ...the development of a digital simulation to conduct end game studies of the Eagle missile warhead- fuze combination. This was one of the first

Review of Literature on Probability of Detection for Liquid Penetrant Nondestructive Testing

DTIC Science & Technology

2011-11-01

increased maintenance costs , or catastrophic failure of safety- critical structure. Knowledge of the reliability achieved by NDT methods, including...representative components to gather data for statistical analysis, which can be prohibitively expensive. To account for sampling variability inherent in any...Sioux City and Pensacola. (Those recommendations were discussed in Section 3.4.) Drury et al report on a factorial experiment aimed at identifying the

Application of 1D Array FBG Configuration for Impact Localization on Composite Wing under Simulated Noise

DTIC Science & Technology

2016-03-30

Grating Sensor Fundamentals FBG sensors consists of grating with periodic variation in the refractive index which reflects certain wavelengths of...is the grating’s effective refractive index and  is the grating period. Bragg wavelength is sensitive to any changes in strain or temperature...Conference on Composite Materials. 2007: Kyoto, Japan. 2. Cartz, L., Nondestructive Testing: Radiography, Ultrasonics, Liquid Penetrant, Magnetic Particle

Efficacy of liquid and foam decontamination technologies for chemical warfare agents on indoor surfaces.

PubMed

Love, Adam H; Bailey, Christopher G; Hanna, M Leslie; Hok, Saphon; Vu, Alex K; Reutter, Dennis J; Raber, Ellen

2011-11-30

Bench-scale testing was used to evaluate the efficacy of four decontamination formulations on typical indoor surfaces following exposure to the liquid chemical warfare agents sarin (GB), soman (GD), sulfur mustard (HD), and VX. Residual surface contamination on coupons was periodically measured for up to 24h after applying one of four selected decontamination technologies [0.5% bleach solution with trisodium phosphate, Allen Vanguard Surface Decontamination Foam (SDF™), U.S. military Decon Green™, and Modec Inc. and EnviroFoam Technologies Sandia Decontamination Foam (DF-200)]. All decontamination technologies tested, except for the bleach solution, performed well on nonporous and nonpermeable glass and stainless-steel surfaces. However, chemical agent residual contamination typically remained on porous and permeable surfaces, especially for the more persistent agents, HD and VX. Solvent-based Decon Green™ performed better than aqueous-based bleach or foams on polymeric surfaces, possibly because the solvent is able to penetrate the polymer matrix. Bleach and foams out-performed Decon Green for penetrating the highly polar concrete surface. Results suggest that the different characteristics needed for an ideal and universal decontamination technology may be incompatible in a single formulation and a strategy for decontaminating a complex facility will require a range of technologies. Copyright © 2011 Elsevier B.V. All rights reserved.

Prevalence of penetration and aspiration on videofluoroscopy in normal individuals without dysphagia.

PubMed

Allen, Jacqui E; White, Cheryl J; Leonard, Rebecca J; Belafsky, Peter C

2010-02-01

To determine the prevalence of penetration and aspiration on videofluoroscopic swallow studies (VFSS) in normal individuals without dysphagia. Case series with planned data collection. A tertiary urban university hospital. Normal adult volunteers without dysphagia, neurological disease, or previous surgery underwent VFSS. Studies were recorded and then reviewed for evidence of penetration or aspiration. The degree of penetration was assessed with the penetration-aspiration scale (PAS). The effect of age, bolus size, and consistency was evaluated. A total of 149 VFSS (596 swallows) were reviewed. The mean age of the cohort was 57 years (+/-19 years); 56 percent were female. Only one (0.6%) individual aspirated on VFSS. Seventeen (11.4%) individuals demonstrated penetration. The mean PAS for the entire cohort was 1.17 (+/-0.66). Prevalence of penetration by swallow was 2.85 percent (17/596). Prevalence of penetration was 9.3 percent in elderly individuals aged >65 years and 14.3 percent in adults aged <65 years (P = 0.49). Prevalence of penetration on a liquid bolus was 3.4 percent (15/447) and on paste was 1.3 percent (2/149) (P > 0.05). Prevalence of penetration for a bolus <30 cc was 2.34 percent (7/298) and for a bolus >30 cc was 5.4 percent (8/149) (P > 0.05). Aspiration on VFSS is not a normal finding. Penetration is present in 11.4 percent of normal adults and is more common with a liquid bolus. Copyright 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.

Analysis of the interphase of a polyamide bonded to chromic acid anodized Ti-6AL-4V

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

Guinta, R.K.; Kander, R.G.

2000-01-06

Structural adhesive joints, when tested as made, typically fail cohesively through the centerline of the adhesive. However, in any study of adhesive joint durability, failure near the adhesive/substrate interface becomes an important consideration. In the current study, an interfacially debonding adhesive test, the notched coating adhesion (NCA) test, was applied to LaRC(trademark) PETI-5 adhesive bonded to chronic acid anodized (CAA) Ti-6Al-4V. Post-failure analysis of the interphase region included X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), field emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM). Mechanical interlocking between an adhesive and a substrate occurs when the liquid adhesivemore » flows into interstices of the substrate, solidifies, and becomes locked in place. Mechanical interlocking is believed to significantly contribute to the adhesion of substrates that exhibit microroughness, such as metal surfaces treated with chromic acid anodization or sodium hydroxide anodization. Filbey and Wightman found that an epoxy penetrated the pores of CAA Ti-6Al-4V, one of the limited number of pore penetration studies that have been reported. In the current study, the penetration of PETI-5 into the pores of CAA Ti-6Al-4V is investigated through analysis of adhesive/substrate failure surfaces.« less

Demonstration of Hazardous Hypervelocity Test Capability

NASA Technical Reports Server (NTRS)

Rodriquez, Karen M.

1991-01-01

NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) participated in a joint test program with NASA JSC Hypervelocity Impact Research Laboratory (HIRL) to determine if JSC was capable of performing hypervelocity impact tests on hazardous targets. Seven pressurized vessels were evaluated under hypervelocity impact conditions. The vessels were tested with various combinations of liquids and gasses at various pressures. Results from the evaluation showed that vessels containing 100-percent pressurized gas sustained more severe damage and had a higher potential for damaging nearby equipment, than vessels containing 75-percent liquid, 25-percent inert pressurized gas. Two water-filled test vessels, one of which was placed behind an aluminum shield, failed by bulging and splitting open at the impact point; pressure was relieved without the vessel fragmenting or sustaining internal damage. An additional water-filled test vessel, placed a greater distance behind an aluminum shield, sustained damage that resembled a shotgun blast, but did not bulge or split open; again, pressure was relieved without the vessel fragmenting. Two test vessels containing volatile liquids (nitro methane and hydrazine) also failed by bulging and splitting open; neither liquid detonated under hypervelocity test conditions. A test vessel containing nitrogen gas failed by relieving pressure through a circular entry hole; multiple small penetrations opposite the point of entry provided high velocity target debris to surrounding objects. A high-pressure oxygen test vessel fragmented upon impact; the ensuing fire and high velocity fragments caused secondary damage to surrounding objects. The results from the evaluation of the pressurized vessels indicated that JSC is capable of performing hypervelocity impact tests on hazardous targets.

The impact of emollients on phototherapy: a review.

PubMed

Asztalos, Manuela L; Heller, Misha M; Lee, Eric S; Koo, John

2013-05-01

When treating psoriasis, various topical emollients exist that can affect the penetration of ultraviolet radiation in phototherapy. Compared with normal-appearing skin with a reflectance of 4% to 5%, psoriatic skin has higher reflectance as a result of its increased air-to-corneocyte interfaces. Studies have tested the effect of emollients on light penetration by assessing psoriatic plaque clearance, differences in minimal erythema dose, and physical properties of the emollient (eg, monochromatic protection factor and absorbance). Psoriatic plaque clearance was found to improve with serous (thin liquid)-based emollients (eg, Vaseline oil [Unilever, Blackfriars, London, UK], mineral oil, and glycerol), whereas clearance decreased with salicylic acid and viscous-based emollients (eg, petrolatum). Emollients with high ultraviolet absorbance properties increased minimal erythema dose, and those with low absorbance properties decreased minimal erythema dose. Interestingly, when a liquid emollient with a refractive index close to that of normal-appearing skin was applied, there was a net increase in light absorption, or a reduction in reflection that exceeded the emollient's innate ability to absorb light. Copyright © 2012 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Application of the modified transient plane source technique for early detection of liquid explosives

NASA Astrophysics Data System (ADS)

Bateman, Robert; Harris, Adam; Lee, Linda; Howle, Christopher R.; Ackermann, Sarah L. G.

2016-05-01

The paper will review the feasibility of adapting the Modified Transient Plane Source (MTPS) method as a screening tool for early-detection of explosives and hazardous materials. Materials can be distinguished from others based on their inherent thermal properties (e.g. thermal effusivity) in testing through different types of barrier materials. A complimentary advantage to this technique relative to other traditional detection technologies is that it can penetrate reflective barrier materials, such as aluminum, easily. A strong proof-of-principle is presented on application of the MTPS transient thermal property measuring in the early-screening of liquid explosives. The work demonstrates a significant sensitivity to distinguishing a wide range of fluids based on their thermal properties through a barrier material. The work covers various complicating factors to the longer-term adoption of such a method including the impact of carbonization and viscosity. While some technical challenges remain, the technique offers significant advantages in complimenting existing detection methods in being able to penetrate reflective metal containers (e.g. aluminum soft drinkscans) with ease.

Kinetic modeling of streamer penetration into de-ionized water

NASA Astrophysics Data System (ADS)

Levko, Dmitry; Sharma, Ashish; Raja, Laxminarayan L.

2018-03-01

Interest in plasma-liquid interaction phenomena has grown in recent years due to applications in plasma medicine, water purification, and plasma-hydrocarbon reforming. The plasma in contact with liquid is generated, for example, using the plasma jets or streamer discharges. The interaction between the streamer and water can cause both physical and chemical modifications of the liquid. In this paper, the interaction between an anode-directed streamer and the de-ionized water is studied using one-dimensional particle-in-cell Monte Carlo collisions model. In this model, plasma species in both gas and liquid phase are considered as the macro-particles. We find that the penetration of the streamer head into the liquid causes ionization of water molecules by electron impact, a process which is usually ignored in the fluid models. The main charge carriers in the liquid phase are negative water ions which agree with earlier experimental and computational modeling studies. Additionally, we observe an ion-rich sheath in the vicinity of the water surface on the gas side.

The detection of tightly closed flaws by nondestructive testing (NDT) methods. [fatigue crack formation in aluminum alloy test specimens

NASA Technical Reports Server (NTRS)

Rummel, W. D.; Rathke, R. A.; Todd, P. H., Jr.; Mullen, S. J.

1975-01-01

Liquid penetrant, ultrasonic, eddy current and X-radiographic techniques were optimized and applied to the evaluation of 2219-T87 aluminum alloy test specimens in integrally stiffened panel, and weld panel configurations. Fatigue cracks in integrally stiffened panels, lack-of-fusion in weld panels, and fatigue cracks in weld panels were the flaw types used for evaluation. A 2319 aluminum alloy weld filler rod was used for all welding to produce the test specimens. Forty seven integrally stiffened panels containing a total of 146 fatigue cracks, ninety three lack-of-penetration (LOP) specimens containing a total of 239 LOP flaws, and one-hundred seventeen welded specimens containing a total of 293 fatigue cracks were evaluated. Nondestructive test detection reliability enhancement was evaluated during separate inspection sequences in the specimens in the 'as-machined or as-welded', post etched and post proof loaded conditions. Results of the nondestructive test evaluations were compared to the actual flaw size obtained by measurement of the fracture specimens after completing all inspection sequences. Inspection data were then analyzed to provide a statistical basis for determining the flaw detection reliability.

Surfactant for dye-penetrant inspection is insensitive to liquid oxygen

NASA Technical Reports Server (NTRS)

1966-01-01

LOX insensitive solvent is blended into a mixture of commercially available surfactants to clean metal surfaces which are to be investigated by the dye-penetrant method. The surfactant mixture is applied before and after application of the dye.

External-Field-Induced Gradient Wetting for Controllable Liquid Transport: From Movement on the Surface to Penetration into the Surface.

PubMed

Li, Yan; He, Linlin; Zhang, Xiaofang; Zhang, Na; Tian, Dongliang

2017-12-01

External-field-responsive liquid transport has received extensive research interest owing to its important applications in microfluidic devices, biological medical, liquid printing, separation, and so forth. To realize different levels of liquid transport on surfaces, the balance of the dynamic competing processes of gradient wetting and dewetting should be controlled to achieve good directionality, confined range, and selectivity of liquid wetting. Here, the recent progress in external-field-induced gradient wetting is summarized for controllable liquid transport from movement on the surface to penetration into the surface, particularly for liquid motion on, patterned wetting into, and permeation through films on superwetting surfaces with external field cooperation (e.g., light, electric fields, magnetic fields, temperature, pH, gas, solvent, and their combinations). The selected topics of external-field-induced liquid transport on the different levels of surfaces include directional liquid motion on the surface based on the wettability gradient under an external field, partial entry of a liquid into the surface to achieve patterned surface wettability for printing, and liquid-selective permeation of the film for separation. The future prospects of external-field-responsive liquid transport are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling of surface tension effects in venturi scrubbing

NASA Astrophysics Data System (ADS)

Ott, Robert M.; Wu, Tatsu K. L.; Crowder, Jerry W.

A modified model of venturi scrubber performance has been developed that addresses two effects of liquid surface tension: its effect on droplet size and its effect on particle penetration into the droplet. The predictions of the model indicate that, in general, collection efficiency increases with a decrease in liquid surface tension, but the range over which this increase is significant depends on the particle size and on the scrubber operating parameters. The predictions further indicate that the increases in collection efficiency are almost totally due to the effect of liquid surface tension on the mean droplet size, and that the collection efficiency is not significantly affected by the ability of the particle to penetrate the droplet.

Transverse injection of a particle-laden liquid jet in supersonic flow: A three-phase flow

NASA Technical Reports Server (NTRS)

Schetz, J. A.; Ogg, J. C.

1980-01-01

The results of a two part study of the behavior of particle laden liquid jets injected into air are presented. Water was used as the liquid carrier and either 1-37 or 13-44 microns diam. spherical glass beads with a specific gravity of 2.8-3.0 as the particles. The observations were mainly photographic. The breakup of jets injected into still air was investigated as a function of particle loading, and the results were compared to the pure liquid jet case. The jets were found to be more stable with particles present. The length to breakup was increased, and the formation of satellite droplets was suppressed. The penetration and breakup of transverse jets in a Mach 3.0 air stream was studied. The general breakup mechanism of wave formation was found to be the same as for the all liquid case. Significant separation of the phases was observed, and the penetration of the liquid phase was reduced compared to all liquid cases at the same value of the jet to free stream momentum flux ratio.

A Controlled Agitation Process for Improving Quality of Canned Green Beans during Agitation Thermal Processing.

PubMed

Singh, Anika; Pratap Singh, Anubhav; Ramaswamy, Hosahalli S

2016-06-01

This work introduces the concept of a controlled agitation thermal process to reduce quality damage in liquid-particulate products during agitation thermal processing. Reciprocating agitation thermal processing (RA-TP) was used as the agitation thermal process. In order to reduce the impact of agitation, a new concept of "stopping agitations after sufficient development of cold-spot temperature" was proposed. Green beans were processed in No. 2 (307×409) cans filled with liquids of various consistency (0% to 2% CMC) at various frequencies (1 to 3 Hz) of RA-TP using a full-factorial design and heat penetration results were collected. Corresponding operator's process time to impart a 10-min process lethality (Fo ) and agitation time (AT) were calculated using heat penetration results. Accordingly, products were processed again by stopping agitations as per 3 agitation regimes, namely; full time agitation, equilibration time agitation, and partial time agitation. Processed products were photographed and tested for visual quality, color, texture, breakage of green beans, turbidity, and percentage of insoluble solids in can liquid. Results showed that stopping agitations after sufficient development of cold-spot temperatures is an effective way of reducing product damages caused by agitation (for example, breakage of beans and its leaching into liquid). Agitations till one-log temperature difference gave best color, texture and visual product quality for low-viscosity liquid-particulate mixture and extended agitations till equilibration time was best for high-viscosity products. Thus, it was shown that a controlled agitation thermal process is more effective in obtaining high product quality as compared to a regular agitation thermal process. © 2016 Institute of Food Technologists®

Characterisation of Ga-coated and Ga-brazed aluminium

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

Ferchaud, E.; Christien, F., E-mail: frederic.christien@univ-nantes.fr; Barnier, V.

This work is devoted to the brazing of aluminium using liquid gallium. Gallium was deposited on aluminium samples at {approx} 50 Degree-Sign C using a liquid gallium 'polishing' technique. Brazing was undertaken for 30 min at 500 Degree-Sign C in air. EDS (Energy Dispersive X-ray Spectroscopy) and AES (Auger Electron Spectroscopy) characterisation of Ga-coated samples has shown that the Ga surface layer thickness is of ten (or a few tens of) nanometres. Furthermore, aluminium oxide layer (Al{sub 2}O{sub 3}) was shown to be 'descaled' during Ga deposition, which ensures good conditions for further brazing. Cross-section examination of Ga-coated samples showsmore » that liquid gallium penetrates into the aluminium grain boundaries during deposition. The thickness of the grain boundary gallium film was measured using an original EDS technique and is found to be of a few tens of nanometres. The depth of gallium grain boundary penetration is about 300 {mu}m at the deposition temperature. The fracture stress of the brazed joints was measured from tensile tests and was determined to be 33 MPa. Cross-section examination of brazed joints shows that gallium has fully dissolved into the bulk and that the joint is really autogenous. - Highlights: Black-Right-Pointing-Pointer Aluminium can be brazed using liquid gallium deposited by a 'polishing' technique. Black-Right-Pointing-Pointer The aluminium oxide layer is 'descaled' during liquid Ga 'polishing' deposition. Black-Right-Pointing-Pointer EDS can be used for determination of surface and grain boundary Ga film thickness. Black-Right-Pointing-Pointer The surface and grain boundary Ga film thickness is of a few tens of nm. Black-Right-Pointing-Pointer Surface and grain boundary gallium dissolves in the bulk during brazing.« less

Phase-partitioning in mixed-phase clouds - An approach to characterize the entire vertical column

NASA Astrophysics Data System (ADS)

Kalesse, H.; Luke, E. P.; Seifert, P.

2017-12-01

The characterization of the entire vertical profile of phase-partitioning in mixed-phase clouds is a challenge which can be addressed by synergistic profiling measurements with ground-based polarization lidars and cloud radars. While lidars are sensitive to small particles and can thus detect supercooled liquid (SCL) layers, cloud radar returns are dominated by larger particles (like ice crystals). The maximum lidar observation height is determined by complete signal attenuation at a penetrated optical depth of about three. In contrast, cloud radars are able to penetrate multiple liquid layers and can thus be used to expand the identification of cloud phase to the entire vertical column beyond the lidar extinction height, if morphological features in the radar Doppler spectrum can be related to the existence of SCL. Relevant spectral signatures such as bimodalities and spectral skewness can be related to cloud phase by training a neural network appropriately in a supervised learning scheme, with lidar measurements functioning as supervisor. The neural network output (prediction of SCL location) derived using cloud radar Doppler spectra can be evaluated with several parameters such as liquid water path (LWP) detected by microwave radiometer (MWR) and (liquid) cloud base detected by ceilometer or Raman lidar. The technique has been previously tested on data from Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) instruments in Barrow, Alaska and is in this study utilized for observations from the Leipzig Aerosol and Cloud Remote Observations System (LACROS) during the Analysis of the Composition of Clouds with Extended Polarization Techniques (ACCEPT) field experiment in Cabauw, Netherlands in Fall 2014. Comparisons to supercooled-liquid layers as classified by CLOUDNET are provided.

The Penetration Behavior of an Annular Gas-Solid Jet Impinging on a Liquid Bath: Comparison with a Conventional Circular Jet

NASA Astrophysics Data System (ADS)

Park, Sung Sil; Dyussekenov, Nurzhan; Sohn, H. Y.

2010-02-01

The top-blow injection technique of a gas-solid mixture through a circular lance is used in the Mitsubishi Continuous Smelting Process. One of the inherent problems associated with this injection is the severe erosion of the hearth refractory below the lances. A new configuration of the lance to form an annular gas-solid jet rather than a circular jet was designed in the laboratory scale. With this new configuration, solid particles leave the lance at a much lower velocity than the gas, and the penetration behavior of the jet is significantly different than with the circular lance in which the solid particles leave the lance at the same high velocity as the gas. The results of cold model tests using an air-sand jet issuing from a circular lance and an annular lance into a water bath showed that the penetration of the annular jet is much less sensitive to the variations in particle feed rate as well as gas velocity than that of the circular jet. Correlation equations for the penetration depth for both circular and annular jets show agreement among the experimentally obtained values.

Test of prototype liquid-water-content meter for aircraft use

NASA Technical Reports Server (NTRS)

Gerber, Hermann E.

1993-01-01

This report describes the effort undertaken to meet the objectives of National Science Foundation Grant ATM-9207345 titled 'Test of Prototype Liquid-Water-Content Meter for Aircraft Use.' Three activities were proposed for testing the new aircraft instrument, PVM-100A: (1) Calibrate the PVM-100A in a facility where the liquid-water-content (LWC) channel, and the integrated surface area channel (PSA) could be compared to standard means for LWC and PSA measurements. Scaling constant for the channels were to be determined in this facility. The fog/wind tunnel at ECN, Petten, The Netherlands was judged the most suitable facility for this effort. (2) Expose the PVM-100A to high wind speeds similar to those expected on research aircraft, and test the anti-icing heaters on the PVM-100A under typical icing conditions expected in atmospheric clouds. The high-speed icing tunnel at NRC, Ottawa, Canada was to be utilized. (3) Operate the PVM-100A on an aircraft during cloud penetrations to determine its stability and practicality for such measurements. The C-131A aircraft of the University of Washington was the aircraft of opportunity for these-tests, which were to be conducted during the 4-week Atlantic Stratocumulus Transition Experiment (ASTEX) in June of 1992.

Pasteurization of grapefruit juice using a centrifugal ultraviolet light irradiator

USDA-ARS?s Scientific Manuscript database

The pharmaceutical industry uses UV irradiators to inactivate viruses in liquids without heat. The penetration depth of UV in some liquids, such as serum plasma, can be short. To overcome this, very thin films may be produced by centrifugal force, small diameter tubing, or other means. Many liquid f...

Unsteady jet in designing innovative drug delivery system

NASA Astrophysics Data System (ADS)

Wang, Cong; Mazur, Paul; Cosse, Julia; Rider, Stephanie; Gharib, Morteza

2014-11-01

Micro-needle injections, a promising pain-free drug delivery method, is constrained by its limited penetration depth. This deficiency can be overcome by implementing fast unsteady jet that can penetrate sub-dermally. The development of a faster liquid jet would increase the penetration depth and delivery volume of micro-needles. In this preliminary work, the nonlinear transient behavior of an elastic tube balloon in providing fast discharge is analyzed. A physical model that combines the Mooney Rivlin Material model and Young-Lapalce's Law was developed and used to investigate the fast discharging dynamic phenomenon. A proof of concept prototype was constructed to demonstrate the feasibility of a simple thumb-sized delivery system to generate liquid jet with desired speed in the range of 5-10 m/s. This work is supported by ZCUBE Corporation.

Apparatus and methods for determining gas saturation and porosity of a formation penetrated by a gas filled or liquid filled borehole

DOEpatents

Wilson, Robert D.

2001-03-27

Methods and apparatus are disclosed for determining gas saturation, liquid saturation, porosity and density of earth formations penetrated by a well borehole. Determinations are made from measures of fast neutron and inelastic scatter gamma radiation induced by a pulsed, fast neutron source. The system preferably uses two detectors axially spaced from the neutron source. One detector is preferably a scintillation detector responsive to gamma radiation, and a second detector is preferably an organic scintillator responsive to both neutron and gamma radiation. The system can be operated in cased boreholes which are filled with either gas or liquid. Techniques for correcting all measurements for borehole conditions are disclosed.

Fumigation of Jute Bags with Ethylene Oxide and Methyl Bromide to Eradicate Potato Ring Rot Bacteria1

PubMed Central

Richardson, L. T.; Monro, H. A. U.

1962-01-01

In a series of full-scale tests, the effectiveness of various fumigant treatments for the eradication of potato ring rot bacteria from bulk lots of contaminated jute bags was evaluated. Survival of these bacteria on infested sample fibers located at various positions within and around a tightly wired bale was determined quantitatively from the growth lag in a liquid medium as indicated by the rate of turbidity development. Ethylene oxide, though highly toxic to Corynebacterium sepedonicum in laboratory tests, failed to penetrate the jute sufficiently to be effective in the interior of a bale. Methyl bromide showed better penetration, but was not sufficiently toxic at practical dosage levels. A mixture of 5% ethylene oxide and 10% methyl bromide achieved complete eradication throughout a bale in an 18-hr exposure period. On the basis of these results, eradication of ring rot bacteria from contaminated jute bags by fumigation with a combination of these two gases would appear to be feasible under commercial conditions. PMID:13982125

Suppressed Release of Clarithromycin from Tablets by Crystalline Phase Transition of Metastable Polymorph Form I.

PubMed

Fujiki, Sadahiro; Watanabe, Narumi; Iwao, Yasunori; Noguchi, Shuji; Mizoguchi, Midori; Iwamura, Takeru; Itai, Shigeru

2015-08-01

The pharmaceutical properties of clarithromycin (CAM) tablets containing the metastable form I of crystalline CAM were investigated. Although the dissolution rate of form I was higher than that of stable form II, the release of CAM from form I tablet was delayed. Disintegration test and liquid penetration test showed that the disintegration of the tablet delayed because of the slow penetration of an external solution into form I tablet. Investigation by scanning electron microscopy revealed that the surface of form I tablet was covered with fine needle-shaped crystals following an exposure to the external solution. These crystals were identified as form IV crystals by powder X-ray diffraction. The phenomenon that CAM releases from tablet was inhibited by fine crystals spontaneously formed on the tablet surface could be applied to the design of sustained-release formulation systems with high CAM contents by minimizing the amount of functional excipients. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Glass transition temperatures of liquid prepolymers obtained by thermal penetrometry

NASA Technical Reports Server (NTRS)

Potts, J. E., Jr.; Ashcraft, A. C.

1973-01-01

Thermal penetrometry is experimental technique for detecting temperature at which frozen prepolymer becomes soft enough to be pierced by weighted penetrometer needle; temperature at which this occurs is called penetration temperature. Apparatus used to obtain penetration temperatures can be set up largely from standard parts.

Observations of a pressurized hydraulic hose under lateral liquid impacts

NASA Astrophysics Data System (ADS)

Stewart, C. D.; Gorman, D. G.

The effects of 'pin-hole' failure of one pressurized hydraulic hose on its neighbour are investigated. A pressurized test hose was inserted into a custom testing apparatus and subjected to a series of ten short duration liquid impacts simulating the pin-hole failure of an initial hose. Subsequent displacements of the hose were filmed and plotted with respect to time. Three distinct pattern groups emerged which were used to explain the resultant damage to the hose. It was observed that the middle pattern, corresponding to impacts 6 and 7, appears to be the point where the very damaging hydraulic penetration mechanism became dominant and the outer layer of the hose failed. On completion of the ten impact series it was observed that a small hole on the outer surface of the hose gave way to a relatively large damaged area in the strength bearing inner braid material.

Gas driven displacement in a Hele-Shaw cell with chemical reaction

NASA Astrophysics Data System (ADS)

White, Andrew; Ward, Thomas

2011-11-01

Injecting a less viscous fluid into a more viscous fluid produces instabilities in the form of fingering which grow radially from the less viscous injection point (Saffman & Taylor, Proc. R. Soc. Lon. A, 1958). For two non-reacting fluids in a radial Hele-Shaw cell the ability of the gas phase to penetrate the liquid phase is largely dependent on the gap height, liquid viscosity and gas pressure. In contrast combining two reactive fluids such as aqueous calcium hydroxide and carbon dioxide, which form a precipitate, presents a more complex but technically relevant system. As the two species react calcium carbonate precipitates and increases the aqueous phase visocosity. This change in viscosity may have a significant impact on how the gas phase penetrates the liquid phase. Experimental are performed in a radial Hele-Shaw cell with gap heights O(10-100) microns by loading a single drop of aqueous calcium hydroxide and injecting carbon dioxide into the drop. The calcium hydroxide concentration, carbon dioxide pressure and gap height are varied and images of the gas penetration are analyzed to determine residual film thickness and bursting times.

Development of three-dimension microelectrode array for bioelectric measurement using the liquidmetal-micromolding technique

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

Liu, Ran, E-mail: liuran@tsinghua.edu.cn; Yang, Xueyao; Chen, Weixing

2013-11-04

A method of manufacturing three-dimension microneedle electrode arrays is presented in this paper using the micromolding technology with liquid metal at room temperature, based on the physical property of the Bi-In-Sn liquid metal alloy, being its melting point especially low. Observed under scanning electron microscopy, the needle body of the electrode chip manufactured using this method has a good consistency. Skin penetration test in-vitro indicates that the microneedle electrode can pierce the stratum corneum and cross the high-impedance layer to acquire electrical signals. Electrical impedance and polarization voltage experimental results show that the electrode chips have great electric characteristics andmore » meet the practical application demands.« less

Preparation of pyrolytic carbon coating on graphite for inhibiting liquid fluoride salt and Xe135 penetration for molten salt breeder reactor

NASA Astrophysics Data System (ADS)

Song, Jinliang; Zhao, Yanling; He, Xiujie; Zhang, Baoliang; Xu, Li; He, Zhoutong; Zhang, DongSheng; Gao, Lina; Xia, Huihao; Zhou, Xingtai; Huai, Ping; Bai, Shuo

2015-01-01

A fixed-bed deposition method was used to prepare rough laminar pyrolytic carbon coating (RLPyC) on graphite for inhibiting liquid fluoride salt and Xe135 penetration during use in molten salt breeder reactor. The RLPyC coating possessed a graphitization degree of 44% and had good contact with graphite substrate. A high-pressure reactor was constructed to evaluate the molten salt infiltration in the isostatic graphite (IG-110, TOYO TANSO CO., LTD.) and RLPyC coated graphite under 1.01, 1.52, 3.04, 5.07 and 10.13 × 105 Pa for 12 h. Mercury injection and molten-salt infiltration experiments indicated the porosity and the salt-infiltration amount of 18.4% and 13.5 wt% under 1.52 × 105 Pa of IG-110, which was much less than 1.2% and 0.06 wt% under 10.13 × 105 Pa of the RLPyC, respectively. A vacuum device was constructed to evaluate the Xe135 penetration in the graphite. The helium diffusion coefficient of RLPyC coated graphite was 2.16 × 10-12 m2/s, much less than 1.21 × 10-6 m2/s of the graphite. Thermal cycle experiment indicated the coatings possessed excellent thermal stability. The coated graphite could effectively inhibit the liquid fluoride salt and Xe135 penetration.

Does the use of a novel self-adhesive flowable composite reduce nanoleakage?

PubMed

Naga, Abeer Abo El; Yousef, Mohammed; Ramadan, Rasha; Fayez Bahgat, Sherif; Alshawwa, Lana

2015-01-01

The aim of the study reported here was to evaluate the performance of a self-adhesive flowable composite and two self-etching adhesive systems, when subjected to cyclic loading, in preventing the nanoleakage of Class V restorations. Wedge-shape Class V cavities were prepared (4×2×2 mm [length × width × depth]) on the buccal surfaces of 90 sound human premolars. Cavities were divided randomly into three groups (n=30) according to the used adhesive (Xeno(®) V [self-etching adhesive system]) and BOND-1(®) SF (solvent-free self-etching adhesive system) in conjunction with Artiste(®) Nano Composite resin, and Fusio™ Liquid Dentin (self-adhesive flowable composite), consecutively. Each group was further divided into three subgroups (n=10): (A) control, (B) subjected to occlusal cyclic loading (90N for 5,000 cycles), and (C) subjected to occlusal cyclic loading (90N for 10,000 cycles). Teeth then were coated with nail polish up to 1 mm from the interface, immersed in 50% silver nitrate solution for 24 hours and tested for nanoleakage using the environmental scanning electron microscopy and energy dispersive analysis X-ray analysis. Data were statistically analyzed using two-way analysis of variance and Tukey's post hoc tests (P≤0.05). The Fusio Liquid Dentin group showed statistically significant lower percentages of silver penetration (0.55 μ) compared with the BOND-1 SF (3.45 μ) and Xeno V (3.82 μ) groups, which were not statistically different from each other, as they both showed higher silver penetration. Under the test conditions, the self-adhesive flowable composite provided better sealing ability. Aging of the two tested adhesive systems, as a function of cyclic loading, increased nanoleakage.

Does the use of a novel self-adhesive flowable composite reduce nanoleakage?

PubMed Central

Naga, Abeer Abo El; Yousef, Mohammed; Ramadan, Rasha; Fayez Bahgat, Sherif; Alshawwa, Lana

2015-01-01

Objective The aim of the study reported here was to evaluate the performance of a self-adhesive flowable composite and two self-etching adhesive systems, when subjected to cyclic loading, in preventing the nanoleakage of Class V restorations. Methods Wedge-shape Class V cavities were prepared (4×2×2 mm [length × width × depth]) on the buccal surfaces of 90 sound human premolars. Cavities were divided randomly into three groups (n=30) according to the used adhesive (Xeno® V [self-etching adhesive system]) and BOND-1® SF (solvent-free self-etching adhesive system) in conjunction with Artiste® Nano Composite resin, and Fusio™ Liquid Dentin (self-adhesive flowable composite), consecutively. Each group was further divided into three subgroups (n=10): (A) control, (B) subjected to occlusal cyclic loading (90N for 5,000 cycles), and (C) subjected to occlusal cyclic loading (90N for 10,000 cycles). Teeth then were coated with nail polish up to 1 mm from the interface, immersed in 50% silver nitrate solution for 24 hours and tested for nanoleakage using the environmental scanning electron microscopy and energy dispersive analysis X-ray analysis. Data were statistically analyzed using two-way analysis of variance and Tukey’s post hoc tests (P≤0.05). Results The Fusio Liquid Dentin group showed statistically significant lower percentages of silver penetration (0.55 μ) compared with the BOND-1 SF (3.45 μ) and Xeno V (3.82 μ) groups, which were not statistically different from each other, as they both showed higher silver penetration. Conclusion Under the test conditions, the self-adhesive flowable composite provided better sealing ability. Aging of the two tested adhesive systems, as a function of cyclic loading, increased nanoleakage. PMID:25848318

Lidocaine self-sacrificially improves the skin permeation of the acidic and poorly water-soluble drug etodolac via its transformation into an ionic liquid.

PubMed

Miwa, Yasushi; Hamamoto, Hidetoshi; Ishida, Tatsuhiro

2016-05-01

Poor transdermal penetration of active pharmaceutical ingredients (APIs) impairs both bioavailability and therapeutic benefits and is a major challenge in the development of transdermal drug delivery systems. Here, we transformed a poorly water-soluble drug, etodolac, into an ionic liquid in order to improve its hydrophobicity, hydrophilicity and skin permeability. The ionic liquid was prepared by mixing etodolac with lidocaine (1:1, mol/mol). Both the free drug and the transformed ionic liquid were characterized by differential scanning colorimetry (DSC), infrared spectroscopy (IR), and saturation concentration measurements. In addition, in vitro skin-permeation testing was carried out via an ionic liquid-containing patch (Etoreat patch). The lidocaine and etodolac in ionic liquid form led to a relatively lower melting point than either lidocaine or etodolac alone, and this improved the lipophilicity/hydrophilicity of etodolac. In vitro skin-permeation testing demonstrated that the Etoreat patch significantly increased the skin permeation of etodolac (9.3-fold) compared with an etodolac alone patch, although an Etoreat patch did not increase the skin permeation of lidocaine, which was consistent with the results when using a lidocaine alone patch. Lidocaine appeared to self-sacrificially improve the skin permeation of etodolac via its transformation into an ionic liquid. The data suggest that ionic liquids composed of approved drugs may substantially expand the formulation preparation method to meet the challenges of drugs which are characterized by poor rates of transdermal absorption. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Fluorescence And Alternative Methods In Urine Drug Testing

NASA Astrophysics Data System (ADS)

Jain, Naresh C.

1988-04-01

Drug abuse has become-one of the most compelling realities _ ot contemporary society. It has penetrated every segment ot our population: trom schools to sports and trom organized crime to board rooms . Drugs in tie w9rkplace allegedly cost government agencies and business millions ot dollars each year in increased absenteeism,. poor work performance, thefts,accidents andwastedtime. The President's Commission on Organized Crime and the federal government are in tavor ot urine drug testing. In fact many employers are now resorting to urine drug testing on current and prospective employees. This presep.tation discusses different laboratory methods used in urine drug.testing, including immunoassays, fluorescence polarization, thin layer chromatography, high pressure liquid chromatography, gas chromatography and gas-chromatography-mass spectrometry.

Direct observation of keyhole characteristics in deep penetration laser welding with a 10 kW fiber laser.

PubMed

Zhang, Mingjun; Chen, Genyu; Zhou, Yu; Li, Shichun

2013-08-26

Keyhole formation is a prerequisite for deep penetration laser welding. Understanding of the keyhole dynamics is essential to improve the stability of the keyhole. Direct observation of the keyhole during deep penetration laser welding of a modified "sandwich" specimen with a 10 kW fiber laser is presented. A distinct keyhole wall and liquid motion along the wall are observed directly for the first time. The moving liquid "shelf" on the front keyhole wall and the accompanying hydrodynamic and vapor phenomena are observed simultaneously. Micro-droplets torn off the keyhole wall and the resultant bursts of vapor are also visualized. The hydrodynamics on the keyhole wall has a dominant effect on the weld defects. The emission spectrum inside the keyhole is captured accurately using a spectrometer to calculate the characteristics of the keyhole plasma plume.

Evaluation of tantalum 316 stainless steel transition joints

NASA Technical Reports Server (NTRS)

Stoner, D. R.

1972-01-01

Tubular transition joints providing a metallurgically bonded connection between tantalum and 316 stainless steel pipe sections were comparatively evaluated for durability under thermal cycling conditions approximating the operation of a SNAP-8 mercury boiler. Both coextruded and vacuum brazed transition joints of 50mm (2 inch) diameter were tested by thermal cycling 100 times between 730 C and 120 C(1350 F and 250 F) in a high vacuum environment. The twelve evaluated transition joints survived the full test sequence without developing leaks, although liquid penetrant bond line indications eventually developed in all specimens. The brazed transition joints exhibited the best dimensional stability and bond line durability.

Partially melted zone in aluminum welds

NASA Astrophysics Data System (ADS)

Huang, Chen-Che

The partially melted zone (PMZ) is a region immediately outside the weld metal where grain boundary (GB) liquation can occur and cause intergranular cracking. Aluminum alloys are known to be susceptible to liquation and liquation cracking. The PMZ of alloy 2219 (essentially Al-6.3Cu) was studied. Liquation is initiated eutectically. Solidification of the GB liquid was directional---upward and toward the weld as a result of the temperature gradients across the PMZ. The liquated material solidifies with severe segregation into a low-strength, low-ductility structure consisting of a solute-depleted ductile phase and a solute-rich brittle eutectic. In tensile testing the maximum load and displacement before failure were both far below those of the base metal. The GB eutectic fractured while the adjacent Cu-depleted a deformed readily under tension. The solidification mode of the grain boundary liquid was mostly planar. However, cellular solidification was also observed near the bottom of partial-penetration welds, where temperature gradients were lowest. The liquation mechanisms in wrought multicomponent aluminum alloys during welding were also studied. Three mechanisms were identified. They cover most, if not all, wrought aluminum alloys. Liquation cracking in the PMZ was investigated in full-penetration aluminum welds. Liquation cracking occurs because the solidifying PMZ is pulled by a solidifying and thus contracting weld metal that is stronger than the PMZ. Liquation cracking can occur if there is significant liquation in the PMZ, if there is no solidification cracking in the adjacent weld metal, and if the PMZ becomes lower in solid fraction (and hence strength) during its terminal solidification than the solidifying weld metal. Liquation cracking in the PMZ was also investigated in partial-penetration aluminum welds. The papillary (nipple) type penetration common in welding with spray transfer of the filler wire actually oscillates along the weld and promotes cracking regardless of the filler metal used. The fast-solidifying weld metal immediately behind the penetration tip contracts and pulls the PMZ near the tip and, regardless of the weld-metal composition, cracking can occur if PMZ liquation is significant.

A statistical analysis of cervical auscultation signals from adults with unsafe airway protection.

PubMed

Dudik, Joshua M; Kurosu, Atsuko; Coyle, James L; Sejdić, Ervin

2016-01-22

Aspiration, where food or liquid is allowed to enter the larynx during a swallow, is recognized as the most clinically salient feature of oropharyngeal dysphagia. This event can lead to short-term harm via airway obstruction or more long-term effects such as pneumonia. In order to non-invasively identify this event using high resolution cervical auscultation there is a need to characterize cervical auscultation signals from subjects with dysphagia who aspirate. In this study, we collected swallowing sound and vibration data from 76 adults (50 men, 26 women, mean age 62) who underwent a routine videofluoroscopy swallowing examination. The analysis was limited to swallows of liquid with either thin (<5 cps) or viscous (≈300 cps) consistency and was divided into those with deep laryngeal penetration or aspiration (unsafe airway protection), and those with either shallow or no laryngeal penetration (safe airway protection), using a standardized scale. After calculating a selection of time, frequency, and time-frequency features for each swallow, the safe and unsafe categories were compared using Wilcoxon rank-sum statistical tests. Our analysis found that few of our chosen features varied in magnitude between safe and unsafe swallows with thin swallows demonstrating no statistical variation. We also supported our past findings with regard to the effects of sex and the presence or absence of stroke on cervical ausculation signals, but noticed certain discrepancies with regards to bolus viscosity. Overall, our results support the necessity of using multiple statistical features concurrently to identify laryngeal penetration of swallowed boluses in future work with high resolution cervical auscultation.

Correlation between laryngeal sensitivity and penetration/aspiration after stroke.

PubMed

Onofri, Suely Mayumi Motonaga; Cola, Paula Cristina; Berti, Larissa Cristina; da Silva, Roberta Gonçalves; Dantas, Roberto Oliveira

2014-04-01

Stroke is the most common neurological disease in adults that is associated with deglutition disorders. The presence of laryngeal sensitivity is very important in developing safe swallowing without risk of pulmonary complications. The aim of this study was to correlate laryngeal sensitivity with laryngeal penetration and tracheal aspiration after swallows of three food consistencies (puree, thickened liquid, and liquid) in poststroke individuals in the late phase. A cross-sectional clinical study was performed with 91 post-ischemic stroke individuals, with oropharyngeal dysphagia, who were in rehabilitation center treatment from 2009 to 2011. They had a mean age of 68.1 years and average time since injury was 22.6 months; 39 had injury to the right hemisphere and 52 had injury to the left hemisphere. All underwent fiberoptic endoscopic evaluation of swallowing and evaluation of laryngeal sensitivity by touching the tip of the endoscope to the arytenoids and aryepiglottic folds. The linear correlation coefficient of Spearman was applied to evaluate the correlation between laryngeal penetration and tracheal aspiration and the presence/absence of laryngeal sensitivity. There was a negative correlation between the observation of penetration and tracheal aspiration and laryngeal sensitivity, with all bolus consistencies (p < 0.001 for aspiration and p ≤ 0.01 for penetration). The absence of laryngeal sensitivity determines the more frequent findings of penetration and tracheal aspiration. This sensory stimulus in the mucosa of the pharynx and larynx is an essential element for safe swallowing and its deficiency associated with altered motor activity can cause laryngeal penetration and aspiration in poststroke individuals regardless of food consistency.

Mechanism and preparation of liquid alkali-free liquid setting accelerator for shotcrete

NASA Astrophysics Data System (ADS)

Qiu, Ying; Ding, Bei; Gan, Jiezhong; Guo, Zhaolai; Zheng, Chunyang; Jiang, Haidong

2017-03-01

A new alkali-free liquid accelerator for shotcrete was prepared through normal temperature drop process by using the nano activated alumina and the modified alcohol amine as the main raw materials. The effect of alkali-free liquid accelerator on the cement setting time and the mechanical properties of mortar, the effect of the penetration strength on the shotcrete rebound were investigated. And the accelerating mechanism of the as-prepared alkali-free liquid accelerator was also analyzed via XRD and SEM characterization methods. The experimental results indicated that the hydration of C3A was accelerated by the polyamine complexation of accelerator, resulting in forming a large number of acicular ettringite and reducing the amount of Ca(OH)2 crystal, which would not affect the later hydration of cement. When the content of alkali-free liquid accelerator was 6%, the initial setting time and final setting time were less than 3min and 8min respectively, and 1d and 28d compressive strength ratios reached 207.6% and 114.2% respectively; beside that, the shotcrete rebound was very low because of the high penetration strength within 30min.

Grain boundaries structures and wetting in doped silicon, nickel and copper

NASA Astrophysics Data System (ADS)

Meshinchi Asl, Kaveh

This thesis reports a series of fundamental investigations of grain boundary wetting, adsorption and structural (phases) transitions in doped Ni, Cu and Si with technological relevance to liquid metal embrittlement, liquid metal corrosion and device applications. First, intrinsically ductile metals are prone to catastrophic failure when exposed to certain liquid metals, but the atomic level mechanism for this effect is not fully understood. A nickel sample infused with bismuth atoms was characterized and a bilayer interfacial phase that is the underlying cause of embrittlement was observed. In a second related study, we showed that addition of minor impurities can significantly enhance the intergranular penetration of bismuth based liquids in polycrystalline nickel and copper, thereby increasing the liquid metal corrosion rates. Furthermore, we extended a concept that was initially proposed in the Rice-Wang model for grain boundary embrittlement to explain our observations of the impurity-enhanced intergranular penetration of liquid metals. Finally, a grain-boundary transition from a bilayer to an intrinsic is observed in the Si-Au system. This observation directly shows that a grain boundary can exhibit a first-order "phase" transition, which often implies abrupt changes in properties.

Arc brazing of austenitic stainless steel to similar and dissimilar metals

NASA Astrophysics Data System (ADS)

Moschini, Jamie Ian

There is a desire within both the stainless steel and automotive industries to introduce stainless steel into safety critical areas such as the crumple zone of modem cars as a replacement for low carbon mild steel. The two main reasons for this are stainless steel's corrosion resistance and its higher strength compared with mild steel. It has been anticipated that the easiest way to introduce stainless steel into the automotive industry would be to incorporate it into the existing design. The main obstacle to be overcome before this can take place is therefore how to join the stainless steel to the rest of the car body. In recent times arc brazil g has been suggested as a joining technique which will eliminate many of the problems associated with fusion welding of zinc coated mild steel to stainless steel.Similar and dissimilar parent material arc brazed joints were manufactured using three copper based filler materials and three shielding gases. The joints were tested in terms of tensile strength, impact toughness and fatigue properties. It was found that similar parent material stainless steel joints could be produced with a 0.2% proof stress in excess of the parent material and associated problems such as Liquid Metal Embrittlement were not experienced. Dissimilar parent material joints were manufactured with an ultimate tensile strength in excess of that of mild steel although during fatigue testing evidence of Liquid Metal Embrittlement was seen lowering the mean fatigue load.At the interface of the braze and stainless steel in the similar material butt joints manufactured using short circuit transfer, copper appeared to penetrate the grain boundaries of the stainless steel without embrittling the parent material. Further microscopic investigation of the interface showed that the penetration could be described by the model proposed by Mullins. However, when dissimilar metal butt joints were manufactured using spray arc transfer, penetration of copper into the stainless steel resulted in embrittlement as discussed by Glickman.

Heat exchanger-accumulator

DOEpatents

Ecker, Amir L.

1980-01-01

What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

Fluid Flow Phenomena during Welding

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

Zhang, Wei

2011-01-01

MOLTEN WELD POOLS are dynamic. Liquid in the weld pool in acted on by several strong forces, which can result in high-velocity fluid motion. Fluid flow velocities exceeding 1 m/s (3.3 ft/s) have been observed in gas tungsten arc (GTA) welds under ordinary welding conditions, and higher velocities have been measured in submerged arc welds. Fluid flow is important because it affects weld shape and is related to the formation of a variety of weld defects. Moving liquid transports heat and often dominates heat transport in the weld pool. Because heat transport by mass flow depends on the direction andmore » speed of fluid motion, weld pool shape can differ dramatically from that predicted by conductive heat flow. Temperature gradients are also altered by fluid flow, which can affect weld microstructure. A number of defects in GTA welds have been attributed to fluid flow or changes in fluid flow, including lack of penetration, top bead roughness, humped beads, finger penetration, and undercutting. Instabilities in the liquid film around the keyhole in electron beam and laser welds are responsible for the uneven penetration (spiking) characteristic of these types of welds.« less

Water-Borne Endovascular Embolics Inspired by the Undersea Adhesive of Marine Sandcastle Worms.

PubMed

Jones, Joshua P; Sima, Monika; O'Hara, Ryan G; Stewart, Russell J

2016-04-06

Transcatheter embolization is used to treat vascular malformations and defects, to control bleeding, and to selectively block blood supply to tissues. Liquid embolics are used for small vessel embolization that require distal penetration. Current liquid embolic agents have serious drawbacks, mostly centered around poor handling characteristics and toxicity. In this work, a water-borne in situ setting liquid embolic agent is described that is based on electrostatically condensed, oppositely charged polyelectrolytes-complex coacervates. At high ionic strengths, the embolic coacervates are injectable fluids that can be delivered through long narrow microcatheters. At physiological ionic strength, the embolic coacervates transition into a nonflowing solid morphology. Transcatheter embolization of rabbit renal arteries demonstrated capillary level penetration, homogeneous occlusion, and 100% devascularization of the kidney, without the embolic crossing into venous circulation. The benign water-borne composition and setting mechanism avoids many of the problems of current liquid embolics, and provides precise temporal and spatial control during endovascular embolization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impact damage resistance of carbon/epoxy composite tubes for the DC-XA liquid hydrogen feedline

NASA Technical Reports Server (NTRS)

Nettles, A. T.

1995-01-01

Low-velocity impacts were inflicted upon two elbow sections of carbon/epoxy feedline that are to be a part of the Delta Clipper-XA flight vehicle. A soap-based liquid leak detector solution was used to inspect the impact sites for leaks of pressurized gas that was pumped into the tube. Visual surface damage was noted and recorded for each impact site. After impact testing of each of the two sections of tubes was completed, the damage zones were disected from the tube and cross sectioned through the impact site. These specimens were polished after potting them in epoxy and were examined for microcracking using a fluorescent dye penetrant technique. The results showed that nonvisible damage could cause microcracking, thereby resulting in leaks through the tube wall.

Subretinal fluid levels of topical, oral, and combined administered ciprofloxacin in humans

PubMed Central

Cekic, O.; Batman, C.; Yasar, U.; Basci, N.; Zilelioglu, O.; Bozkurt, A.

2000-01-01

AIMS—To investigate the subretinal fluid (SRF) penetration of ciprofloxacin following topical, oral, and combined administration.
METHODS—34 patients undergoing conventional retinal reattachment surgery were randomly assigned to three groups. Twelve patients received topical ciprofloxacin, 11 patients received oral ciprofloxacin, and the other 11 patients received combined drug administration. SRF drug level was measured by using high performance liquid chromatography method.
RESULTS—The highest drug concentrations of all tested modes were attained following combined administration and lowest following topical administration (p <0.001). The SRF drug concentration following oral administration was also significantly higher than that of topical administration (p <0.001). Concentrations after oral and combined administration did not differ significantly (p = 0.217).
CONCLUSIONS—Topical ciprofloxacin can penetrate SRF. Ocular bioavailability of ciprofloxacin in SRF after oral and combined administration is equivalent.

 PMID:10966968

Detecting a liquid and solid H2O layer by geophysical methods

NASA Astrophysics Data System (ADS)

Yoshikawa, K.; Romanovsky, V.; Tsapin, A.; Brown, J.

2002-12-01

The objective is to detect the hydrological and cryological structure of the cold continuous permafrost subsurface using geophysical methods. We believe that a lot of water potentially exists as solid and liquid phases underground on Mars. It is likely that the liquid fluid would be high in saline concentration (brine). The ground freezing process involves many hydrological processes including enrichment of the brine layer. The brine layer is an important environment for ancient and/or current life to exist on terrestrial permafrost regions. The existence of a Martian brine layer would increase the possibility of the existence of life, as on Earth. In situ electric resistivity measurement will be the most efficient method to determine brine layer as well as massive H2O ice in the permafrost. However, the wiring configuration is unlikely to operate on the remote planetary surface. Satellite-born Radar and/or EM methods will be the most accessible methods for detecting the hydrological and cryological structure. We are testing several geophysical methods at the brine layer site in Barrow and massive pingo ice site in Fairbanks, Alaska. The radar system is affected by the dielectric properties of subsurface materials, which allows for evidence of liquid phase in the frozen ground. The dielectric constant varies greatly between liquid water and frozen ground. The depth of the terrestrial (and probably Martian) brine layer is frequently located deeper than the maximum detecting depth of the impulse type of the ground penetrating radar system. Once we develop a radar system with a deeper penetrating capability (Lower frequency), the dispersion of the ground ice will be the key function for interpretation of these signals. We will improve and use radar signals to understand the hydrological and cryological structure in the permafrost. The core samples and borehole temperature data validate these radar signals.

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.

Heat Loads Due to Small Penetrations in Multilayer Insulation Blankets

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Heckle, K. W.; Fesmire, J. E.

2017-01-01

Abstract: This paper covers cryogenic, tensile testing and research completed on a number of epoxies used in cryogenic applications. Epoxies are used in many different applications; however, this research focused on the use of epoxy used to bond MLI standoffs to cryogenic storage tanks and the loads imparted to the tank through the MLI. To conduct testing, samples were made from bare stainless steel, aluminum and primed aluminum. Testing involved slowly cooling test samples with liquid nitrogen then applying gradually increasing tensile loads to the epoxy. The testing evaluated the strength and durability of epoxies at cryogenic temperatures and serves as a base for future testing. The results of the tests showed that some epoxies withstood the harsh conditions while others failed. The two epoxies yielding the best results were Masterbond EP29LPSP and Scotch Weld 2216. For all metal surfaces tested, both epoxies had zero failures for up to 11.81 kg of mass.

Investigations of needle-free jet injections.

PubMed

Schramm-Baxter, J R; Mitragotri, S

2004-01-01

Jet injection is a needle-free drug delivery method in which a high-speed stream of fluid impacts the skin and delivers drugs. Although a number of jet injectors are commercially available, especially for insulin delivery, they have a low market share compared to needles possibly due to occasional pain associated with jet injection. Jets employed by the traditional jet injectors penetrate deep into the dermal and sub-dermal regions where the nerve endings are abundantly located. To eliminate the pain associated with jet injections, we propose to utilize microjets that penetrate only into the superficial region of the skin. However, the choice of appropriate jet parameters for this purpose is challenging owing to the multiplicity of factors that determine the penetration depth. Here, we describe the dependence of jet injections into human skin on the power of the jet. Dermal delivery of liquid jets was quantified using two measurements, penetration of a radiolabeled solute, mannitol, into skin and the shape of jet dispersion in the skin which was visualized using sulforhodamine B. The dependence of the amount of liquid delivered in the skin and the geometric measurements of jet dispersion on nozzle diameter and jet velocity was captured by a single parameter, jet power.

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

Importance of pH-regulated charge density on the electrophoresis of soft particles

NASA Astrophysics Data System (ADS)

Gopmandal, Partha P.; Ohshima, H.

2017-02-01

The present study deals with the electrophoresis of spherical soft particles consisting of an ion and liquid-penetrable but liquid-flow-impenetrable inner core surrounded by an ion and fluid-penetrable polyelectrolyte layer. The inner core is considered to be dielectric and bearing basic functional group coated with polyelectrolyte layer containing acidic functional group. An approximate expression for the electrophoretic mobility of such a particle is obtained under a low potential limit. The electrophoretic behaviour of the undertaken particle is investigated for a wide range of bulk pH values and electrolyte concentrations. Our study also indicates some remarkable features of the electrophoresis e.g., occurrence of zero mobility, mobility reversal etc.

Liquid crystal polymers: evidence of hairpin defects in nematic main chains, comparison with side chain polymers

NASA Astrophysics Data System (ADS)

Li, M. H.; Brûlet, A.; Keller, P.; Cotton, J. P.

1996-09-01

This article describes the conformation of two species of liquid crystalline polymers as revealed by small angle neutron scattering. The results obtained with side chain polymers are recalled. The procedure used to analyze the scattering data of main chains in the nematic phase is reported in this paper. It permits a demonstration of the existence of hairpins. Comparison of both polymer species shows that in the isotropic phase, the two polymers adopt a random coil conformation. In the nematic phase, the conformations are very different; the side chains behave as a melt of penetrable random coils whereas the main chains behave as a nematic phase of non penetrable cylinders.

Use of the quartz crystal microbalance to determine the monomeric friction coefficient of polyimides

NASA Technical Reports Server (NTRS)

Bechtold, Mary M.

1995-01-01

When a thin film of polymer is coated on to a quartz crystal microbalance (QCM), the QCM can be used to detect the rate of increase in weight of the polymer film as the volatile penetrant diffuses into the polymer. From this rate information the diffusion coefficient of the penetrant into the polymer can be computed. Calculations requiring this diffusion coefficient lead to values which approximate the monomeric friction coefficient of the polymer. This project has been concerned with the trial of crystal oscillating circuits suitable for driving polymer coated crystals in an atmosphere of penetrant. For these studies done at room temperature, natural rubber was used as an easily applied polymer that is readily penetrated by toluene vapors, qualities anticipated with polyimides when they are tested at T(g) in the presence of toluene. Three quartz crystal oscillator circuits were tested. The simplest circuit used +/- 5 volt dc and had a transistor to transistor logic (TTL) inverter chip that provides a 180 deg phase shift via a feed back loop. This oscillator circuit was stable but would not drive the crystal when the crystal was coated with polymer and subjected to toluene vapors. Removal of a variable resistor from this circuit increased stability but did not otherwise increase performance. Another driver circuit tested contained a two stage differential input, differential output, wide band video amplifier and also contain a feed back loop. The circuit voltage could not be varied and operated at +/- 5 volts dc; this circuit was also stable but failed to oscillate the polymer coated crystal in an atmosphere saturated with toluene vapors. The third oscillator circuit was of similar construction and relied on the same video amplifier but allowed operation with variable voltage. This circuit would drive the crystal when the crystal was submerged in liquid toluene and when the crystal was coated with polymer and immersed in toluene vapors. The frequency readings obtained when using this oscillating circuit are highly variable. This circuit requires further modification to stabilize frequency readings before its use in studies to determine the diffusion coefficient of penetrant molecules into a polymer film coated on a QCM.

Summary of nondestructive testing theory and practice

NASA Technical Reports Server (NTRS)

Meister, R. P.; Randall, M. D.; Mitchell, D. K.; Williams, L. P.; Pattee, H. E.

1972-01-01

The ability to fabricate design critical and man-rated aerospace structures using materials near the limits of their capabilities requires a comprehensive and dependable assurance program. The quality assurance program must rely heavily on nondestructive testing methods for thorough inspection to assess properties and quality of hardware items. A survey of nondestructive testing methods is presented to provide space program managers, supervisors and engineers who are unfamiliar with this technical area with appropriate insight into the commonly accepted nondestructive testing methods available, their interrelationships, used, advantages and limitations. Primary emphasis is placed on the most common methods: liquid penetrant, magnetic particle, radiography, ultrasonics and eddy current. A number of the newer test techniques including thermal, acoustic emission, holography, microwaves, eddy-sonic and exo-electron emission, which are beginning to be used in applications of interest to NASA, are also discussed briefly.

Effect of Temperature and Sheet Temper on Isothermal Solidification Kinetics in Clad Aluminum Brazing Sheet

NASA Astrophysics Data System (ADS)

Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

2016-09-01

Isothermal solidification (IS) is a phenomenon observed in clad aluminum brazing sheets, wherein the amount of liquid clad metal is reduced by penetration of the liquid clad into the core. The objective of the current investigation is to quantify the rate of IS through the use of a previously derived parameter, the Interface Rate Constant (IRC). The effect of peak temperature and initial sheet temper on IS kinetics were investigated. The results demonstrated that IS is due to the diffusion of silicon (Si) from the liquid clad layer into the solid core. Reduced amounts of liquid clad at long liquid duration times, a roughened sheet surface, and differences in resolidified clad layer morphology between sheet tempers were observed. Increased IS kinetics were predicted at higher temperatures by an IRC model as well as by experimentally determined IRC values; however, the magnitudes of these values are not in good agreement due to deficiencies in the model when applied to alloys. IS kinetics were found to be higher for sheets in the fully annealed condition when compared with work-hardened sheets, due to the influence of core grain boundaries providing high diffusivity pathways for Si diffusion, resulting in more rapid liquid clad penetration.

Improved lifetime high voltage switch electrode

NASA Astrophysics Data System (ADS)

Halverson, W.

1985-06-01

In this Phase 1 Small Business Innovation Research (SBIR) program, preliminary tests of ion implantation to increase the lifetime of spark switch electrodes have indicated that a 185 keV carbon ion implant into a tungsten-copper composite has reduced electrode erosion by a factor of two to four. Apparently, the thin layer of tungsten carbide (WC) has better thermal properties than pure tungsten; the WC may have penetrated into the unimplanted body of the electrode by liquid and/or solid phase diffusion during erosion testing. These encouraging results should provide the basis for a Phase 2 SBIR program to investigate further the physical and chemical effects of ion implantation on spark gap electrodes and to optimize the technique for applications.

Combination downflow-upflow vapor-liquid separator

DOEpatents

Kidwell, John H.; Prueter, William P.; Eaton, Andrew M.

1987-03-10

An improved vapor-liquid separator having a vertically disposed conduit for flow of a mixture. A first, second and third plurality of curved arms penetrate and extend within the conduit. A cylindrical member is radially spaced from the conduit forming an annulus therewith and having perforations and a retaining lip at its upper end.

Liquid-phase penetration under unsteady in-cylinder conditions: Soy- and Cuphea-derived biodiesel fuels vs. conventional diesel

USDA-ARS?s Scientific Manuscript database

Accelerated dilution of engine-lubrication oil is a significant potential issue when fueling with biodiesel. Biodiesel produced from some feedstocks is less volatile than conventional diesel, which makes wall-impingement of liquid fuel more likely, a problem that could be exacerbated by advanced in...

Anti-infiltration for fabrication of a suspended nanoparticle layer on porous close-packed colloidal arrays.

PubMed

Teh, Lay K; Yan, Qingfeng; Wong, Chee C

2009-04-01

We develop a new method to fabricate suspended sheets of nanocrystals (NCs) on porous surfaces. The method relies on the resistance of an aqueous suspension droplet to infiltrate a porous network; hence, the method is named anti-infiltration. The process works by combining fluid dynamics of a liquid droplet during impact/absorption onto a porous surface with the convective self-assembly of NCs. The immobilization of the liquid droplet edge due to the self-assembly of NCs at the meniscus is harnessed to halt the lateral spreading of the droplet and, consequently, the capillary penetration of the liquid immediately after droplet impact. Further capillary penetration of the liquid is drastically reduced because of the competition between capillary forces and convective losses as well as the rapid occlusion of the pores as soon as a continuous NC film has formed upon evaporation of the suspension. This method holds promise for a wide variety of optoelectronic, sensing, and separation membrane applications. As an example, we demonstrate that these suspended NC layers are suitable candidates as planar defects embedded within a colloidal photonic crystal.

Numerical parametric studies of spray combustion instability

NASA Technical Reports Server (NTRS)

Pindera, M. Z.

1993-01-01

A coupled numerical algorithm has been developed for studies of combustion instabilities in spray-driven liquid rocket engines. The model couples gas and liquid phase physics using the method of fractional steps. Also introduced is a novel, efficient methodology for accounting for spray formation through direct solution of liquid phase equations. Preliminary parametric studies show marked sensitivity of spray penetration and geometry to droplet diameter, considerations of liquid core, and acoustic interactions. Less sensitivity was shown to the combustion model type although more rigorous (multi-step) formulations may be needed for the differences to become apparent.

Penetration enhancing effects of selected natural oils utilized in topical dosage forms.

PubMed

Viljoen, Joe M; Cowley, Amé; du Preez, Jan; Gerber, Minja; du Plessis, Jeanetta

2015-01-01

Various natural products, including oils, have been utilized as penetration enhancers due to their "safety profiles". These oils contain fatty acids promoting skin permeability through lipid fluidization within the stratum corneum; and might therefore be able to effectively enhance transdermal drug delivery. We investigated possible penetration enhancing properties of selected oils, utilizing flurbiprofen as marker compound in emulgel formulations. The formulations were compared to a liquid paraffin emulgel and a hydrogel to establish any significant penetration enhancing effects. Gas chromatographic analysis of the natural oils was performed at ambient temperature to determine the fatty acid composition in each selected natural oils. Franz cell diffusion studies and tape stripping methods were employed to study delivery of the marker into, and through the skin. The following rank order for the emulgel flux-values was obtained: Hydrogel > olive oil > liquid paraffin > coconut oil > grape seed oil > Avocado oil ≥ Crocodile oil > Emu oil. Results suggested that oils containing predominantly mono-unsaturated oleic acid, on average increased the flux of the marker to a larger extent than oils containing an almost even mixture of both mono- and poly-unsaturated fatty acids. Oils comprising saturated fatty acids (SFAs) with alkyl chains between C12 and C14, increased the marker flux to a higher extent than oils containing C16-C18 SFAs. Effects observed for branched fatty acids, however, did not vary significantly from effects for unbranched fatty acids with the same carbon chain length. Natural oils possess penetration enhancing effects.

Hybrid electrolytes incorporated with dandelion-like silane-Al2O3 nanoparticles for high-safety high-voltage lithium ion batteries

NASA Astrophysics Data System (ADS)

Xu, Hewei; Shi, Junli; Hu, Guosheng; He, Ying; Xia, Yonggao; Yin, Shanshan; Liu, Zhaoping

2018-07-01

One of the crucial challenge for developing high safety and high voltage lithium ion batteries is to find a reliable electrolyte system. In this work, we report a kind of hybrid electrolytes, which are used for high-voltage lithium ion batteries and are expected to be able to effectively enhance the battery safety. The hybrid electrolytes are obtained by incorporating silane-Al2O3 (Al2O3-ST) into liquid electrolyte, which combines the merits of both solid electrolyte and liquid electrolyte. The Al2O3-ST nanoparticles help to increase lithium-ion transference number and to enhance battery safety, while liquid electrolyte contributes to high ionic conductivity. The cycling stability and rate capacity of LiNi0.5Mn1.5O4/Li batteries are improved by using the hybrid electrolytes. Nail-penetration tests indicate that LiNi0.6Mn0.2Co0.2O2/graphite battery with hybrid electrolyte owns obviously enhanced safety than that using traditional liquid electrolyte. This work provides new insight on electrolyte design for high-safety high-voltage lithium ion batteries.

Coarse-grained molecular dynamics simulation of activated penetrant transport in glassy polymers.

PubMed

Zhang, Kai; Meng, Dong; Müller-Plathe, Florian; Kumar, Sanat K

2018-01-17

Membrane separations of gas mixtures strive to maximize the permeability of a desired species while keeping out undesired ones. Permeability vs. selectivity data from many polymer membranes for a given gas pair with diameters d A and d B are typically collected in a "Robeson plot"', and are bound from above by a line with a slope λ = (d B /d A ) 2 - 1. A microscopic understanding of this relationship, especially λ, is still missing. We perform molecular dynamics simulations of penetrant diffusion using three different coarse-grained polymer models over a wide range of penetrant sizes, temperatures, and monomer densities. The empirically relevant λ = (d B /d A ) 2 - 1 is only found for polymers that are either supercooled liquids with caged segmental dynamics or glasses and when the penetrant size is approximately half the Kuhn length of the chains, for which the penetrant diffusion is an activated process.

Optimization of ethylene glycol concentrations, freezing rates and holding times in liquid nitrogen vapor for cryopreservation of rhesus macaque (Macaca mulatta) sperm.

PubMed

Yang, Shihua; Ping, Shuhuang; Si, Wei; He, Xiechao; Wang, Xinyi; Lu, Yongqing; Ji, Shaohui; Niu, Yuyu; Ji, Weizhi

2011-06-01

Ethylene glycol (EG) has been speculated to be the most appropriate penetrating cryoprotectant for cryopreservation of rhesus macaque sperm due to its higher permeability coefficient. The present study aimed to determine the optimal EG concentration, freezing rate and holding time in liquid nitrogen (LN(2)) vapor for rhesus sperm cryopreservation. Among six tested EG concentrations (0, 0.18, 0.35, 0.7, 1.4 and 2.1 M), 0.7 M EG showed the most effective cryoprotection (P<0.05). Sperm frozen with 0.7 M EG at -183°C/min showed higher post-thaw motility than sperm frozen at -10, -67 or -435°C/min (P<0.05). Sperm frozen in LN(2) vapor at -183°C/min with 0.7 M EG and a holding time of 10 min showed higher post-thaw motility compared with a holding time of 5 or 15 min (P<0.05). The function of sperm cryopreserved at the optimized EG concentration, freezing rate and holding time was further evaluated by in vitro fertilization. Of the 36 oocytes collected from gonadotropin-stimulated rhesus macaques, 61.1% were fertilized, and 61.1, 44.4 and 36.1% of the oocytes developed to 2 cells, morulae and blastocysts, respectively. Our findings provide an alternative penetrating cryoprotectant and optimal protocol for genetic preservation purposes in this important species.

Time-dependent limited penetrable visibility graph analysis of nonstationary time series

NASA Astrophysics Data System (ADS)

Gao, Zhong-Ke; Cai, Qing; Yang, Yu-Xuan; Dang, Wei-Dong

2017-06-01

Recent years have witnessed the development of visibility graph theory, which allows us to analyze a time series from the perspective of complex network. We in this paper develop a novel time-dependent limited penetrable visibility graph (TDLPVG). Two examples using nonstationary time series from RR intervals and gas-liquid flows are provided to demonstrate the effectiveness of our approach. The results of the first example suggest that our TDLPVG method allows characterizing the time-varying behaviors and classifying heart states of healthy, congestive heart failure and atrial fibrillation from RR interval time series. For the second example, we infer TDLPVGs from gas-liquid flow signals and interestingly find that the deviation of node degree of TDLPVGs enables to effectively uncover the time-varying dynamical flow behaviors of gas-liquid slug and bubble flow patterns. All these results render our TDLPVG method particularly powerful for characterizing the time-varying features underlying realistic complex systems from time series.

Nitrogen dioxide vapor penetration of chlorobutyl rubber SCAPE under operational conditions

NASA Technical Reports Server (NTRS)

Schehl, T. A.; Beall, T. W.

1980-01-01

Operational self contained atmospheric protective ensembles (SCAPE suits) and fabric from the suits were subjected to a series of tests designed to determine the amount of exposure a wearer of the suit would receive if a spill of the hypergolic oxidizer nitrogen tetroxide (N2O4) should occur nearby. The results of these tests show that a wearer of a "stock" SCAPE suit equipped with a standard liquid air pack, if exposed to a spill resulting in a 26 percent increase of oxidizer in the surrounding atmosphere, will experiment no detectable concentration of nitrogen dioxide (NO2) inside the suit for 15 minutes. Thereafter, the NO2 concentration within the suit will increase for 35 minutes at a rate of 0.07 ppm per minute and then at a gradually decreasing rate until an equilibrium concentration of 3.4 ppm is attained after 100 minutes. Momentary increases of as much as 1.6 ppm can be expected if the wearer were to rise quickly from a squatting position, but the additional NO2 would be dissipated within three minutes. The effect of liquid and vapor N2O4 and of liquid monomethylhydrazine on permeation rates and tensile strength of the SCAPE suit fabric was also investigated.

Stress fields in soft material induced by injection of highly-focused microjets

NASA Astrophysics Data System (ADS)

Miyazaki, Yuta; Endo, Nanami; Kawamoto, Sennosuke; Kiyama, Akihito; Tagawa, Yoshiyuki

2017-11-01

Needle-free drug injection systems using high-speed microjets are of great importance for medical innovations since they can solve problems of the conventional needle injection systems. However, the mechanical stress acting on the skin/muscle of patients during the penetration of liquid-drug microjets had not been clarified. In this study we investigate the stress caused by the penetration of microjets into soft materials, which is compared with the stress induced by the penetration of needles. In order to capture high-speed temporal evolution of the stress field inside the material, we utilized a high-speed polarized camera and gelatin that resembles human skin. Remarkably we find clear differences in the stress fields induced by microjets and needles. On one hand, high shear stress induced by the microjets is attenuated immediately after the injection, even though the liquid stays inside the soft material. On the other hand, high-shear stress induced by the needles stays and never decays unless the needles are entirely removed from the material. JSPS KAKENHI Grant Numbers 26709007 and 17H01246.

Fiscal year 1976 progress report on a feasibility study evaluating the use of surface penetrators for planetary exploration

NASA Technical Reports Server (NTRS)

Blanchard, M. B.; Oberbeck, V. R.; Bunch, T. E.; Reynolds, R. T.; Canning, T. N.; Jackson, R. W.

1976-01-01

The feasibility of employing penetrators for exploring Mars was examined. Eight areas of interest for key scientific experiments were identified. These include: seismic activity, imaging, geochemistry, water measurement, heatflow, meteorology, magnetometry, and biochemistry. In seven of the eight potential experiment categories this year's progress included: conceptual design, instrument fabrication, instrument performance evaluation, and shock loading of important components. Most of the components survived deceleration testing with negligible performance changes. Components intended to be placed inside the penetrator forebody were tested up to 3,500 g and components intended to be placed on the afterbody were tested up to 21,000 g. A field test program was conducted using tentative Mars penetrator mission constraints. Drop tests were performed at two selected terrestrial analog sites to determine the range of penetration depths for anticipated common Martian materials. Minimum penetration occurred in basalt at Amboy, California. Three full-scale penetrators penetrated 0.4 to 0.9 m into the basalt after passing through 0.3 to 0.5 m of alluvial overburden. Maximum penetration occurred in unconsolidated sediments at McCook, Nebraska. Two full-scale penetrators penetrated 2.5 to 8.5 m of sediment. Impact occurred in two kinds of sediment: loess and layered clay. Deceleration g loads of nominally 2,000 for the forebody and 20,000 for the afterbody did not present serious design problems for potential experiments. Penetrators have successfully impacted into terrestrial analogs of the probable extremes of potential Martian sites.

Examination of adhesive penetration in modified wood using fluorescence microscopy

Treesearch

Jermal G. Chandler; Rishawn L. Brandon; Charles R. Frihart

2005-01-01

Adhesive bonding takes place when an adhesive undergoes the conversion from liquid to solid. The liquid properties are needed for the adhesive to fully wet the bonding substance, and the solid properties are needed for the strength required for the union of the final product. The mobility of an adhesive depends heavily on its own physical and chemical properties and...

Penetration tests to study the mechanical tribological properties of chisel type knife

NASA Astrophysics Data System (ADS)

Vlăduţoiu, L.; Chişiu, G.; Andrei, T.; Predescu, A.; Muraru, C.; Vlăduţ, V.

2017-02-01

The goal of this study was to analyze the behaviour of chisel knife type penetration in a certain type of sand. A series of penetration tests were carried out with chisel knife type, the answer to penetration depending mainly on nature, shape, size of knife and operating parameters such as speed, depth and working conditions. Tests were conducted in work conditions with wet sand and dry sand and determined force of resistance to penetration of the chisel knife type to a certain depth.

Method For Characterizing Residual Stress In Metals

DOEpatents

Jacobson, Loren A.; Michel, David J.; Wyatt, Jeffrey R.

2002-12-03

A method is provided for measuring the residual stress in metals. The method includes the steps of drilling one or more holes in a metal workpiece to a preselected depth and mounting one or more acoustic sensors on the metal workpiece and connecting the sensors to an electronic detecting and recording device. A liquid metal capable of penetrating into the metal workpiece placed at the bottom of the hole or holes. A recording is made over a period of time (typically within about two hours) of the magnitude and number of noise events which occur as the liquid metal penetrates into the metal workpiece. The magnitude and number of noise events are then correlated to the internal stress in the region of the workpiece at the bottom of the hole.

Human Skin Permeation Studies with PPARγ Agonist to Improve Its Permeability and Efficacy in Inflammatory Processes.

PubMed

Silva-Abreu, Marcelle; Espinoza, Lupe Carolina; Rodríguez-Lagunas, María José; Fábrega, María-José; Espina, Marta; García, María Luisa; Calpena, Ana Cristina

2017-11-28

Rosacea is the most common inflammatory skin disease. It is characterized by erythema, inflammatory papules and pustules, visible blood vessels, and telangiectasia. The current treatment has limitations and unsatisfactory results. Pioglitazone (PGZ) is an agonist of peroxisome proliferator-activated receptors (PPARs), a nuclear receptor that regulates important cellular functions, including inflammatory responses. The purpose of this study was to evaluate the permeation of PGZ with a selection of penetration enhancers and to analyze its effectiveness for treating rosacea. The high-performance liquid chromatography (HPLC) method was validated for the quantitative determination of PGZ. Ex vivo permeation experiments were realized in Franz diffusion cells using human skin, in which PGZ with different penetration enhancers were assayed. The results showed that the limonene was the most effective penetration enhancer that promotes the permeation of PGZ through the skin. The cytotoxicity studies and the Draize test detected cell viability and the absence of skin irritation, respectively. The determination of the skin color using a skin colorimetric probe and the results of histopathological studies confirmed the ability of PGZ-limonene to reduce erythema and vasodilation. This study suggests new pharmacological indications of PGZ and its possible application in the treatment of skin diseases, namely rosacea.

Effects of Surface Electrical Stimulation Both at Rest and During Swallowing in Chronic Pharyngeal Dysphagia§

PubMed Central

Ludlow, Christy L.; Humbert, Ianessa; Saxon, Keith; Poletto, Christopher; Sonies, Barbara; Crujido, Lisa

2006-01-01

We tested two hypotheses using surface electrical stimulation in chronic pharyngeal dysphagia: that stimulation 1) lowered the hyoid bone and/or larynx when applied at rest, and 2) increased aspiration, penetration or pharyngeal pooling during swallowing. Bipolar surface electrodes were placed on the skin overlying the submandibular and laryngeal regions. Maximum tolerated levels of stimulation were applied while patients held their mouth closed at rest. Videofluoroscopic recordings were used to measure hyoid movements in the superior-inferior (s-i) and anterior-posterior (a-p) dimensions and the subglottic air column (s-i) position while stimulation was on and off. Patients swallowed 5 ml liquid when stimulation was off, at low sensory stimulation levels, and at maximum tolerated levels (motor). Speech pathologists blinded to condition, tallied the frequency of aspiration, penetration, pooling and esophageal entry from videofluorographic recordings of swallows. Only significant (p=0.0175) hyoid depression occurred during stimulation at rest. Aspiration and pooling were significantly reduced only with low sensory threshold levels of stimulation (p=0.025) and not during maximum levels of surface electrical stimulation. Those patients who had reduced aspiration and penetration during swallowing with stimulation had greater hyoid depression during stimulation at rest (p= 0.006). Stimulation may have acted to resist patients’ hyoid elevation during swallowing. PMID:16718620

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.

Growth and analysis of gallium arsenide-gallium antimonide single and two-phase nanoparticles

NASA Astrophysics Data System (ADS)

Schamp, Crispin T.

When evaluating the path of phase transformations in systems with nanoscopic dimensions one often relies on bulk phase diagrams for guidance because of the lack of phase diagrams that show the effect of particle size. The GaAs-GaSb pseudo-binary alloy is chosen for study to gain insight into the size dependence of solid-solubility in a two-phase system. To this end, a study is performed using independent laser ablation of high purity targets of GaAs and GaSb. The resultant samples are analyzed by transmission electron microscopy. Experimental results indicate that GaAs-GaSb nanoparticles have been formed with compositions that lie within the miscibility gap of bulk GaAs-GaSb. An unusual nanoparticle morpohology resembling the appearance of ice cream cones has been observed in single component experiments. These particles are composed of a spherical cap of Ga in contact with a crystalline cone of either GaAs or GaSb. The cones take the projected 2-D shape of a triangle or a faceted gem. The liquid Ga is found to consistently be of spherical shape and wets to the widest corners of the cone, suggesting an energy minimum exists at that wetting condition. To explore this observation a liquid sphere is modeled as being penetrated by a solid gem. The surface energies of the solid and liquid, and interfacial energy are summed as a function of penetration depth, with the sum showing a cusped minimum at the penetration depth corresponding to the waist of the gem. The angle of contact of the liquid wetting the cone is also calculated, and Young's contact angle is found to occur when the derivative of the total energy with respect to penetration depth is zero, which can be a maximum or a minimum depending on the geometrical details. The spill-over of the meniscus across the gem corners is found to be energetically favorable when the contact angle achieves the value of the equilibrium angle; otherwise the meniscus is pinned at the corners.

Miniature penetrator (MinPen) acceleration recorder development test

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

Franco, R.J.; Platzbecker, M.R.

1998-08-01

The Telemetry Technology Development Department at Sandia National Laboratories actively develops and tests acceleration recorders for penetrating weapons. This new acceleration recorder (MinPen) utilizes a microprocessor-based architecture for operational flexibility while maintaining electronics and packaging techniques developed over years of penetrator testing. MinPen has been demonstrated to function in shock environments up to 20,000 Gs. The MinPen instrumentation development has resulted in a rugged, versatile, miniature acceleration recorder and is a valuable tool for penetrator testing in a wide range of applications.

Evaluation of filter media for particle number, surface area and mass penetrations.

PubMed

Li, Lin; Zuo, Zhili; Japuntich, Daniel A; Pui, David Y H

2012-07-01

The National Institute for Occupational Safety and Health (NIOSH) developed a standard for respirator certification under 42 CFR Part 84, using a TSI 8130 automated filter tester with photometers. A recent study showed that photometric detection methods may not be sensitive for measuring engineered nanoparticles. Present NIOSH standards for penetration measurement are mass-based; however, the threshold limit value/permissible exposure limit for an engineered nanoparticle worker exposure is not yet clear. There is lack of standardized filter test development for engineered nanoparticles, and development of a simple nanoparticle filter test is indicated. To better understand the filter performance against engineered nanoparticles and correlations among different tests, initial penetration levels of one fiberglass and two electret filter media were measured using a series of polydisperse and monodisperse aerosol test methods at two different laboratories (University of Minnesota Particle Technology Laboratory and 3M Company). Monodisperse aerosol penetrations were measured by a TSI 8160 using NaCl particles from 20 to 300 nm. Particle penetration curves and overall penetrations were measured by scanning mobility particle sizer (SMPS), condensation particle counter (CPC), nanoparticle surface area monitor (NSAM), and TSI 8130 at two face velocities and three layer thicknesses. Results showed that reproducible, comparable filtration data were achieved between two laboratories, with proper control of test conditions and calibration procedures. For particle penetration curves, the experimental results of monodisperse testing agreed well with polydisperse SMPS measurements. The most penetrating particle sizes (MPPSs) of electret and fiberglass filter media were ~50 and 160 nm, respectively. For overall penetrations, the CPC and NSAM results of polydisperse aerosols were close to the penetration at the corresponding median particle sizes. For each filter type, power-law correlations between the penetrations measured by different instruments show that the NIOSH TSI 8130 test may be used to predict penetrations at the MPPS as well as the CPC and NSAM results with polydisperse aerosols. It is recommended to use dry air (<20% RH) as makeup air in the test system to prevent sodium chloride particle deliquescing and minimizing the challenge particle dielectric constant and to use an adequate neutralizer to fully neutralize the polydisperse challenge aerosol. For a simple nanoparticle penetration test, it is recommended to use a polydisperse aerosol challenge with a geometric mean of ~50 nm with the CPC or the NSAM as detectors.

Leak test adapter for containers

DOEpatents

Hallett, Brian H.; Hartley, Michael S.

1996-01-01

An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

Percutaneous penetration of benzene and benzene contained in solvents used in the rubber industry

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

Maibach, H.I.; Anjo, D.M.

1981-09-01

Penetration of benzene through the skin of the rhesus monkey was determined using /sup 14/C-benzene, and quantitating the labelled metabolites in urine. The modes of application and amounts of benzene that penetrated the skin (indicated in parentheses) are as follows: (1) a single, direct cutaneous application of liquid benzene (0.172 +/- 0.139%); (2) a single application of benzene-containing (0.36%) solvent (0.0805 +/- 0.0306%); (3) multiple washes with full-strength benzene (0.848 +/- 0.0806%); (4) multiple washes with the benzene-containing (0.35%) solvent (0.431 +/- 0.258%); (5) removal of the stratum corneum followed by application of full-strength benzene (0.09 +/- 0.627%); and (6)more » application of benzene to the palmar surface (0.651 +/- 0.482%). Until more complete human data becomes available, benzene penetration in the monkey may be used to estimate penetration in man, both for industrial hygiene purposes and general toxicological use.« less

Toward jet injection by continuous-wave laser cavitation

NASA Astrophysics Data System (ADS)

Berrospe-Rodriguez, Carla; Visser, Claas Willem; Schlautmann, Stefan; Rivas, David Fernandez; Ramos-Garcia, Ruben

2017-10-01

This is a study motivated by the need to develop a needle-free device for eliminating major global healthcare problems caused by needles. The generation of liquid jets by means of a continuous-wave laser, focused into a light absorbing solution, was studied with the aim of developing a portable and affordable jet injector. We designed and fabricated glass microfluidic devices, which consist of a chamber where thermocavitation is created and a tapered channel. The growth of a vapor bubble displaces and expels the liquid through the channel as a fast traveling jet. Different parameters were varied with the purpose of increasing the jet velocity. The velocity increases with smaller channel diameters and taper ratios, whereas larger chambers significantly reduce the jet speed. It was found that the initial position of the liquid-air meniscus interface and its dynamics contribute to increased jet velocities. A maximum velocity of 94±3 m/s for a channel diameter of D=120 μm, taper ratio n=0.25, and chamber length E=200 μm was achieved. Finally, agarose gel-based skin phantoms were used to demonstrate the potential of our devices to penetrate the skin. The maximum penetration depth achieved was ˜1 mm, which is sufficient to penetrate the stratum corneum and for most medical applications. A meta-analysis shows that larger injection volumes will be required as a next step to medical relevance for laser-induced jet injection techniques in general.

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.

Fire Resistance Testing of Bulkhead and Deck Penetrations. Phase 2

DTIC Science & Technology

1988-12-01

thick steel plate. All sample 12 construction was representative of Class A-0 construction. The UL staff secured insulation ( rockwool batts) to the...designated side of the steel plates and penetrants for testing as Class A-60 deck assemblies. The rockwool batts complied with the Class A-60...insulated with rockwool batts and tested for a Class A-60 rating. This group consisted of one steel penetration, eight copper penetrations, four PVC

High-temperature compatibility between liquid metal as PWR fuel gap filler and stainless steel and high-density concrete

NASA Astrophysics Data System (ADS)

Wongsawaeng, Doonyapong; Jumpee, Chayanit; Jitpukdee, Manit

2014-08-01

In conventional nuclear fuel rods for light-water reactors, a helium-filled as-fabricated gap between the fuel and the cladding inner surface accommodates fuel swelling and cladding creep down. Because helium exhibits a very low thermal conductivity, it results in a large temperature rise in the gap. Liquid metal (LM; 1/3 weight portion each of lead, tin, and bismuth) has been proposed to be a gap filler because of its high thermal conductivity (∼100 times that of He), low melting point (∼100 °C), and lack of chemical reactivity with UO2 and water. With the presence of LM, the temperature drop across the gap is virtually eliminated and the fuel is operated at a lower temperature at the same power output, resulting in safer fuel, delayed fission gas release and prevention of massive secondary hydriding. During normal reactor operation, should an LM-bonded fuel rod failure occurs resulting in a discharge of liquid metal into the bottom of the reactor pressure vessel, it should not corrode stainless steel. An experiment was conducted to confirm that at 315 °C, LM in contact with 304 stainless steel in the PWR water chemistry environment for up to 30 days resulted in no observable corrosion. Moreover, during a hypothetical core-melt accident assuming that the liquid metal with elevated temperature between 1000 and 1600 °C is spread on a high-density concrete basement of the power plant, a small-scale experiment was performed to demonstrate that the LM-concrete interaction at 1000 °C for as long as 12 h resulted in no penetration. At 1200 °C for 5 h, the LM penetrated a distance of ∼1.3 cm, but the penetration appeared to stop. At 1400 °C the penetration rate was ∼0.7 cm/h. At 1600 °C, the penetration rate was ∼17 cm/h. No corrosion based on chemical reactions with high-density concrete occurred, and, hence, the only physical interaction between high-temperature LM and high-density concrete was from tiny cracks generated from thermal stress. Moreover, for as high as 1600 °C, the non-reactive LM was experimentally confirmed not to show any chemical reaction with air or moisture in the air. This experimental work confirmed the excellent compatibility behaviors between the LM as a PWR fuel gap filler and stainless steel and high-density concrete in the high-temperature regime.

Hypervelocity penetration against mechanical properties of target materials

NASA Astrophysics Data System (ADS)

Kamarudin, Khairul Hasni; Abdullah, Mohamad Faizal; Zaidi, Ahmad Mujahid Ahmad; Nor, Norazman M.; Ismail, Ariffin; Yusof, Mohammed Alias; Hilmi, Ahmad Humaizi

2018-02-01

This paper study the mechanical properties behavior of metal plates against hypervelocity penetration caused by shaped charge. Five different materials were used as target specimen fabricated from welded stacks of material plates, namely Rolled Homogeneous Armor (RHA), Hardox-500, mild steel, aluminum and brass. Specimens had undergone an initial monolithic test consist of tensile tests and microstructure observations, followed by series of hydrodynamics penetration blast tests using shape charge mechanism. Results from blast test shows that the least penetrated specimen is RHA (58mm) followed by Hardox-500 (92 mm), mild steel (110 mm), Brass (155 mm) and aluminum 238 mm). Comparing these with the specimen yield strength from the tensile test results shows that Hardox-500 has higher yield strength (Sy) followed by RHA, mild steel, brass and aluminum, which are 1370 MPa, 1320 MPa, 280,221 respectively, which are not inversely proportional to the penetration. However, the ultimate tensile strength (Sut) where the RHA were the highest followed by Hardox-500, mild steel, brass and aluminum, were inversely proportional with the depth of penetration. The penetration results also show consistence relation with energy absorption.

Structure and reactions in some amphiphilic association systems

NASA Astrophysics Data System (ADS)

Guo, Rong

1999-06-01

The partial determinations of phase diagrams for some typical surfactants, such as SDS, CTAB and Triton X-100, give the basic aggregated states of the surfactant systems. In the micellar solutions, the diffusion coefficients of some surfactant association systems are determined by the cyclic voltammetry without any probe and used to describe the phase structure. (1) The first CMC, which represents the formation of spherical micelles, and the second CMC, which represents the transformation from spherical to rod-like micelles, are measured. The first and the second CMC are 8.0 x 10-3 mol. L -1 and 5.6 x 10-3 mol. L-1 for SDS, 8.9 x 10-4 mol. L-1 and 2.1 x 10-2 mol. L-1 for CTAB, and 3.2 x 10 -4 mol. L-1 and 1.3 x 10-3 mol. L-1 for Triton X-100, respectively. (2) The addition of polar additives, such as ethanol and benzyl alcohol (BA) in SDS micelles, or hexanol in Triton X-100 micelles, increases the diffusion coefficients and diffusion activation energy, decreases the micropolarity of the micelles with different shape, and causes the transformation from rod-like micelles to spherical ones or from spherical micelles to bicontinuous structure. (3) The isotropic region, which connects to the water comer in the phase diagram, is probably not an area of a single O/W structure, but an area with three different structures---the rod structure, spherical structure and the bicontinuous one. In the lyotropic liquid crystalline phase, the measurements of the small angle X-ray diffraction indicate that the structure parameters, such as interlayer spacing and water penetration, are related to the compositions of the surfactant association systems. The lamellar liquid crystal has a high water penetration but the hexagonal liquid crystal only has a water penetration about 0.05. Some surfactant association systems have been applied in the hydrotrope action of vitamin C (VC) and preparation of nanoparticles, respectively. Vitamin C (VC) can be used as hydrotrope agent in the cationic surfactant CTAB system with various co-surfactants: n-pentanol, n-octanol, n-valeric acid, and n-caproic acid, but not in SDS or Triton X-100 systems. Presence of VC stabilizes both W/O and O/W microemulsions but destabilizes the lamellar liquid crystalline phase. Hence, the "phase transition" from the lamellar liquid crystalline phase to the isotropic phase of O/W, W/O and bicontinuous structure phase occurs with the addition of VC. The hydrotropic action of VC has been used in sunscreens to increase the solubility of sunscreen E 557. The UV absorption spectra of E557 in various media surprisingly had a dependence on the colloid structure. A new method, the preparation of water-soluble nanoparticles, has been found by employing the effect of the penetration of solvent from water layer to amphiphilic layer in lamellar liquid crystals on the solubility of inorganic salts. Water-insoluble nanoparticles have been synthesized by the reaction of two water-soluble inorganic salts in the lamellar liquid crystal. The particle size is less than 10nm and can be controlled by the thickness of the solvent layer in the lamellar liquid crystal. The lamellar liquid crystalline phase of the Triton X-100/decanol/water system has been chosen as a medium because of its large lamellar liquid crystal region and its stability when inorganic salts are added.

Characteristics and limitations of GPS L1 observations from submerged antennas - Theoretical investigation in snow, ice, and freshwater and practical observations within a freshwater layer

NASA Astrophysics Data System (ADS)

Steiner, Ladina; Meindl, Michael; Geiger, Alain

2018-05-01

Observations from a submerged GNSS antenna underneath a snowpack need to be analyzed to investigate its potential for snowpack characterization. The magnitude of the main interaction processes involved in the GPS L1 signal propagation through different layers of snow, ice, or freshwater is examined theoretically in the present paper. For this purpose, the GPS signal penetration depth, attenuation, reflection, refraction as well as the excess path length are theoretically investigated. Liquid water exerts the largest influence on GPS signal propagation through a snowpack. An experiment is thus set up with a submerged geodetic GPS antenna to investigate the influence of liquid water on the GPS observations. The experimental results correspond well with theory and show that the GPS signal penetrates the liquid water up to three centimeters. The error in the height component due to the signal propagation delay in water can be corrected with a newly derived model. The water level above the submerged antenna could also be estimated.

Thermal performance of a liquid hydrogen tank multilayer insulation system at warm boundary temperatures of 630, 530, and 152 R

NASA Astrophysics Data System (ADS)

Stochl, Robert J.; Knoll, Richard H.

1991-06-01

The results are presented of a study conducted to obtain experimental heat transfer data on a liquid hydrogen tank insulated with 34 layers of MLI (multilayer insulation) for warm side boundary temperatures of 630, 530, and 150 R. The MLI system consisted of two blankets, each blanket made up of alternate layers of double silk net (16 layers) and double aluminized Mylar radiation shields (15 layers) contained between two cover sheets of Dacron scrim reinforced Mylar. The insulation system was designed for and installed on a 87.6 in diameter liquid hydrogen tank. Nominal layer density of the insulation blankets is 45 layers/in. The insulation system contained penetrations for structural support, plumbing, and electrical wiring that would be representative of a cryogenic spacecraft. The total steady state heat transfer rates into the test tank for shroud temperatures of 630, 530, 152 R were 164.4, 95.8, and 15.9 BTU/hr respectively. The noninsulation heat leaks into the tank (12 fiberglass support struts, tank plumbing, and instrumentation lines) represent between 13 to 17 pct. of the total heat input. The heat input values would translate to liquid H2 losses of 2.3, 1.3, and 0.2 pct/day, with the tank held at atmospheric pressure.

Thermal performance of a liquid hydrogen tank multilayer insulation system at warm boundary temperatures of 630, 530, and 152 R

NASA Astrophysics Data System (ADS)

Stochl, Robert J.; Knoll, Richard H.

1991-06-01

The results are presented of a study conducted to obtain experimental heat transfer data on a liquid hydrogen tank insulated with 34 layers of MLI (multilayer insulation) for warm side boundary temperatures of 630, 530, and 150 R. The MLI system consisted of two blankets, each blanket made up of alternate layers of double silk net (16 layers) and double aluminized Mylar radiation shields (15 layers) contained between two cover sheets of Dacron scrim reinforced Mylar. The insulation system was designed for and installed on an 87.6 in. diameter liquid hydrogen tank. Nominal layer density of the insulation blankets is 45 layers/in. The insulation system contained penetrations for structural support, plumbing, and electrical wiring that would be representative of a cryogenic spacecraft. The total steady state heat transfer rates into the test tank for shroud temperatures of 630, 530, 152 R were 164.4, 95.8, and 15.9 BTU/hr, respectively. The noninsulation heat leaks into the tank (12 fiberglass support struts, tank plumbing, and instrumentation lines) represent between 13 to 17 pct. of the total heat input. The heat input values would translate to liquid H2 losses of 2.3, 1.3, and 0.2 pct/day, with the tank held at atmospheric pressure.

Constraints on the Geophysical Detection of Brine within the Europa Ice Shell From a Synthesis of Dielectric Spectroscopy Measurements

NASA Astrophysics Data System (ADS)

Stillman, D. E.; Grimm, R. E.; MacGregor, J. A.; Sander-Olhoeft, M.; Brown, J.

2016-12-01

The numerous chaos regions, lenticulae and double layer ridges on Europa's surface suggest that pockets of liquid currently exist or did exist. Here we investigate the sensitivity of ice-penetrating radar (IPR) and magnetotelluric (MT) methods to the putative electrical properties of Europa's ice shell, based on a set of plausible ice-shell scenarios and a synthesis of laboratory dielectric spectroscopy measurements of hundreds of ice samples. We evaluate models of the electrical conductivity of the ice shell as a function of impurity content, temperature and liquid vein network tortuosity. Europa's ice shell is estimated to be 5-30 km thick. If its thickness exceeds 10 km, the shell likely convects within its bottom 70%, while the upper part is thermally conductive. These convective downwellings and upwellings are estimated to have core temperatures of 235 K and 253 K, respectively. Downwellings are so cold that they are below of eutectic temperature of most Europa-relevant salts, but not below that of Europa-relevant acids. Given the low temperature of downwelling ice, IPR is expected to penetrate through it. Warmer upwellings may possess significant amounts of unfrozen water if the shell is acid- or salt-rich. The injection of liquid or the melting of acid- or salt-rich ice will eventually lead to refreezing, as the shell conducts away this excess heat. As liquid freezes, impurities are rejected and concentrated in a liquid vein network surrounding relatively pure ice crystals. These vein networks remain liquid as long as the temperature is greater than that of the eutectic of the bulk impurities. Therefore, in upwellings, vein networks should be briny and hence more electrically conductive. The electrical conductivity of these vein networks depends on the initial impurity concentration of the liquid, impurity type, temperature and the tortuosity of any vein networks. The latter property decreases with increasing ice recrystallization. We conclude that IPR will likely be able to map the top of the unfrozen zone, assuming typical marine ice salt concentrations, but not penetrate through it. MT measurements could complement IPR effectively, because they could measure a conductivity depth profile within the unfrozen part of the ice shell, where the electrical conductivity exceeds 0.1 mS/m.

Sample Acquisition and Handling System from a Remote Platform

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, Stewart; Jones, Jack A.

2011-01-01

A system has been developed to acquire and handle samples from a suspended remote platform. The system includes a penetrator, a penetrator deployment mechanism, and a sample handler. A gravity-driven harpoon sampler was used for the system, but other solutions can be used to supply the penetration energy, such as pyrotechnic, pressurized gas, or springs. The deployment mechanism includes a line that is attached to the penetrator, a spool for reeling in the line, and a line engagement control mechanism. The penetrator has removable tips that can collect liquid, ice, or solid samples. The handling mechanism consists of a carousel that can store a series of identical or different tips, assist in penetrator reconfiguration for multiple sample acquisition, and deliver the sample to a series of instruments for analysis. The carousel sample handling system was combined with a brassboard reeling mechanism and a penetrator with removable tips. It can attach the removable tip to the penetrator, release and retrieve the penetrator, remove the tip, and present it to multiple instrument stations. The penetrator can be remotely deployed from an aerobot, penetrate and collect the sample, and be retrieved with the sample to the aerobot. The penetrator with removable tips includes sample interrogation windows and a sample retainment spring for unconsolidated samples. The line engagement motor can be used to control the penetrator release and reeling engagement, and to evenly distribute the line on the spool by rocking between left and right ends of the spool. When the arm with the guiding ring is aligned with the spool axis, the line is free to unwind from the spool without rotating the spool. When the arm is perpendicular to the spool axis, the line can move only if the spool rotates.

Universal penetration test apparatus with fluid penetration sensor

DOEpatents

Johnson, Phillip W.; Stampfer, Joseph F.; Bradley, Orvil D.

1999-01-01

A universal penetration test apparatus for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material.

Resin Viscosity Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

NASA Astrophysics Data System (ADS)

Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

2018-06-01

Viscosity of the liquid resin effects the chemical and mechanical properties of the pultruded composite. In resin injection pultrusion manufacturing the liquid resin is injected into a specially designed tapered injection chamber through the injection slots present on top and bottom of the chamber. The resin is injected at a pressure so as to completely wetout the fiber reinforcements inside the tapered injection chamber. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the center of chamber causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to efficaciously penetrate through the compacted fibers and achieve complete wetout. The impact of resin viscosity on resin flow, fiber compaction, wetout and on the final product is further discussed. Injection chamber design predominantly effects the resin flow inside the chamber and the minimum injection pressure required to completely wet the fibers. Therefore, a desirable injection chamber design is such that wetout occurs at lower injection pressures and at low internal pressures inside the injection chamber.

Occupational safety considerations with hydrazine

NASA Technical Reports Server (NTRS)

Clewell, Harvey J., III; Mcdougal, James N.; George, Marilyn E.; Andersen, Melvin E.

1992-01-01

Hydrazine is a reducing agent that is most commonly used as a propellant and as an oxygen scavenger in boilers. Hydrazine is extremely irritating and has been demonstrated to produce both acute and chronic toxicity. As a result, the established permissible inhalation exposure limits are very low, and respiration protection is required whenever vapors are present. Liquid hydrazine penetrates the skin and produces a chemical burn; therefore, some protective measures must also be taken to protect the skin from liquid contact. Often, however, a cumbersome, whole-body protective suit is worn to protect against skin contact with vapor as well. To what extent it is actually necessary to protect skin from vapor penetration had not previously been demonstrated. In an attempt to answer this question, we conducted a study with rats to compare the dermal penetration of hydrazine vapor with inhalation. Pharmacokinetic modeling was used to compare body burdens resulting from these different routes of exposure. The analysis concluded that the vapor concentration during a skin-only exposure would have to be at least 200 times higher than that during inhalation to achieve the same body burden. This type of estimation illustrates the use of predictive toxicology in occupational exposures.

Characterization and In Vitro Permeation Study of Cubic Liquid Crystal Containing Sinomenine Hydrochloride.

PubMed

Chu, Xiaoqin; Li, Qian; Gui, Shuangying; Li, Zhengguang; Cao, Jiaojiao; Jiang, Jianqin

2018-05-08

This study developed a new transdermal delivery system for the improved delivery of sinomenine hydrochloride (SH). The delivery system utilized the advantages of lyotropic liquid crystals (LLC) creating an adaptable system that offers a variety of options for the field of transdermal delivery. The formulation was prepared, characterized, and evaluated for its skin penetration in vitro. In the study, the appearance of samples was characterized by visual observation, and these LLC gels were colorless and transparent. Polarizing light microscopy (PLM) and small-angle X-ray diffraction (SAXS) were used to analyze the internal structures of gels, and the gels displayed a cubic double-diamond (P n 3 m ) internal structure with a dark field of vision. The Franze diffusion cell was used to evaluate its skin penetration. There were several factors which might influence the skin penetration of drugs, such as drug loading, water content, and the layer spacing of the LLC. In our case, drug concentration gradient played a more powerful role. The result of in vitro permeation studies demonstrated that the drug concentration was higher; the cumulative osmotic quantity of SH (Q) was greater. Therefore, the system was a promising formulation for successful percutaneous delivery of SH through the skin.

Resin Viscosity Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

NASA Astrophysics Data System (ADS)

Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

2017-08-01

Viscosity of the liquid resin effects the chemical and mechanical properties of the pultruded composite. In resin injection pultrusion manufacturing the liquid resin is injected into a specially designed tapered injection chamber through the injection slots present on top and bottom of the chamber. The resin is injected at a pressure so as to completely wetout the fiber reinforcements inside the tapered injection chamber. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the center of chamber causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to efficaciously penetrate through the compacted fibers and achieve complete wetout. The impact of resin viscosity on resin flow, fiber compaction, wetout and on the final product is further discussed. Injection chamber design predominantly effects the resin flow inside the chamber and the minimum injection pressure required to completely wet the fibers. Therefore, a desirable injection chamber design is such that wetout occurs at lower injection pressures and at low internal pressures inside the injection chamber.

Bacterial biofilm shows persistent resistance to liquid wetting and gas penetration

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

Epstein, Alexander K.; Pokroy, Boaz; Seminara, Agnese

2011-09-28

Most of the world's bacteria exist in robust, sessile communities known as biofilms, ubiquitously adherent to environmental surfaces from ocean floors to human teeth and notoriously resistant to antimicrobial agents. We report the surprising observation that Bacillus subtilis biofilm colonies and pellicles are extremely nonwetting, greatly surpassing the repellency of Teflon toward water and lower surface tension liquids. The biofilm surface remains nonwetting against up to 80% ethanol as well as other organic solvents and commercial biocides across a large and clinically important concentration range. We show that this property limits the penetration of antimicrobial liquids into the biofilm, severelymore » compromising their efficacy. To highlight the mechanisms of this phenomenon, we performed experiments with mutant biofilms lacking ECM components and with functionalized polymeric replicas of biofilm microstructure. We show that the nonwetting properties are a synergistic result of ECM composition, multiscale roughness, reentrant topography, and possibly yet other factors related to the dynamic nature of the biofilm surface. Finally, we report the impenetrability of the biofilm surface by gases, implying defense capability against vapor-phase antimicrobials as well. These remarkable properties of B. subtilis biofilm, which may have evolved as a protection mechanism against native environmental threats, provide a new direction in both antimicrobial research and bioinspired liquid-repellent surface paradigms.« less

Structural Effects of Gating Poly(3-hexylthiophene) through an Ionic Liquid

DOE PAGES

Guardado, Jesus O.; Salleo, Alberto

2017-07-17

Ionic liquids are increasingly employed as dielectrics to generate high charge densities and enable low-voltage operation with organic semiconductors. But, effects on structure and morphology of the active material are not fully known, particularly for permeable semiconductors such as conjugated polymers, in which ions from the ionic liquid can enter and electrochemically dope the semicrystalline film. In order to understand when ions enter, where they go, and how they affect the film, thin films of the archetypal semiconducting polymer, poly(3-hexylthiophene), are electrochemically doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, the archetypal ionic liquid. High-resolution, ex situ X-ray diffraction measurements and complete pole figuresmore » reveal changes with applied voltage, cycling, and frequency in lattice spacing, crystallite orientation, and crystallinity in the bulk and at the buried interface. Dopant ions penetrate the film and enter the crystallites at sufficiently high voltages and low frequencies. Upon infiltrating crystallites, ions permanently expand lamellar stacking and contract pi-stacking. Cycling amplifies these effects, but higher frequencies mitigate the expansion of bulk crystallites as ions are hindered from entering crystallites. Furthermore, this mechanistic understanding of the structural effects of ion penetration will help develop models of the frequency and voltage impedance response of electrochemically doped conjugated polymers and advance electronic applications.« less

Structural Effects of Gating Poly(3-hexylthiophene) through an Ionic Liquid

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

Guardado, Jesus O.; Salleo, Alberto

Ionic liquids are increasingly employed as dielectrics to generate high charge densities and enable low-voltage operation with organic semiconductors. But, effects on structure and morphology of the active material are not fully known, particularly for permeable semiconductors such as conjugated polymers, in which ions from the ionic liquid can enter and electrochemically dope the semicrystalline film. In order to understand when ions enter, where they go, and how they affect the film, thin films of the archetypal semiconducting polymer, poly(3-hexylthiophene), are electrochemically doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, the archetypal ionic liquid. High-resolution, ex situ X-ray diffraction measurements and complete pole figuresmore » reveal changes with applied voltage, cycling, and frequency in lattice spacing, crystallite orientation, and crystallinity in the bulk and at the buried interface. Dopant ions penetrate the film and enter the crystallites at sufficiently high voltages and low frequencies. Upon infiltrating crystallites, ions permanently expand lamellar stacking and contract pi-stacking. Cycling amplifies these effects, but higher frequencies mitigate the expansion of bulk crystallites as ions are hindered from entering crystallites. Furthermore, this mechanistic understanding of the structural effects of ion penetration will help develop models of the frequency and voltage impedance response of electrochemically doped conjugated polymers and advance electronic applications.« less

Thermal performance of a modularized replaceable multilayer insulation system for a cryogenic stage

NASA Technical Reports Server (NTRS)

Knoll, R. H.

1977-01-01

A rugged modularized MLI system for a 2.23-meter-diameter (87.6-in.-diam) liquid hydrogen tank was designed, fabricated, and tested under simulated near-earth and deep-space environments. The two blankets of the system were each composed of 17 double-aluminized Mylar radiation shields separated by silk net. The unit area weight of the installed system was 1.54 kg/sqm (0.32 lb/sq ft). The overall average heat transferred into the insulated tank was 22.7 and 0.98 watts (77.4 and 3.3 Btu/hr) during simulated near-earth and deep-space testing, respectively. The near-earth result was only 2.6 times that predicted for an undisturbed insulation system (i.e., no seams or penetrations). Tests indicate that this insulation concept could be useful for a cryogenic space tug or orbit transfer vehicle application.

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.

Environmental surveillance at Los Alamos during 1994

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

NONE

1996-07-01

This report describes environmental monitoring activities at Los Alamos National Laboratory for 1994. Data were collected to assess external penetrating radiation, airborne emissions, liquid effluents, radioactivity of environmental materials and food stuffs, and environmental compliance.

Penetration studies of an extremely lipophilic active model substance from an oil-in-water emulsion: influence of the lipophilicity of the formulation in human skin - part 2.

PubMed

Naumann, S; Lange, S; Polak, G; Kalhoelfer, V; Motlagh, L; Goebel, A; Wohlrab, J; Neubert, R H H

2014-01-01

The effect of the lipophilicity of a carrier on human skin penetration of an extremely lipophilic active model substance was evaluated by using Franz type diffusion cells. Oil-in-water model emulsions containing different amounts of the oily phase were prepared, and Myritol® PC (M-PC) was selected as lipophilic marker component of the oily phase. The penetrated amounts of the lipophilic model substance salicyloyl phytosphingosine (SP) were determined by high-performance liquid chromatography with ultraviolet detection, while M-PC was detected using gas chromatography coupled with mass spectrometry. It has been ascertained that the amount of the lipid phase within the emulsion influenced the penetration profile of the active ingredient SP. The emulsion containing the lowest proportion of the lipid phase provides the best conditions for SP penetration. Surprisingly, the penetration behavior of M-PC was influenced by the oily phase in the same way. Regarding the M-PC and the SP penetration profiles from each emulsion, a solvent drag mechanism can be assumed whereby M-PC acts as penetration enhancer. In conclusion, the penetration rate of the active ingredient SP and the marker component M-PC are in reverse proportion to the oil content of the formulations. The lipophilicity of SP and M-PC, their solubility and their thermodynamic activity within the vehicle could have an effect on their penetration behavior. Additionally, M-PC has the property to enhance the penetration rates of extremely lipophilic substances even at low concentrations.

Effect of Pore Size and Pore Connectivity on Unidirectional Capillary Penetration Kinetics in 3-D Porous Media using Direct Numerical Simulation

NASA Astrophysics Data System (ADS)

Fu, An; Palakurthi, Nikhil; Konangi, Santosh; Comer, Ken; Jog, Milind

2017-11-01

The physics of capillary flow is used widely in multiple fields. Lucas-Washburn equation is developed by using a single pore-sized capillary tube with continuous pore connection. Although this equation has been extended to describe the penetration kinetics into porous medium, multiple studies have indicated L-W does not accurately predict flow patterns in real porous media. In this study, the penetration kinetics including the effect of pore size and pore connectivity will be closely examined since they are expected to be the key factors effecting the penetration process. The Liquid wicking process is studied from a converging and diverging capillary tube to the complex virtual 3-D porous structures with Direct Numerical Simulation (DNS) using the Volume-Of-Fluid (VOF) method within the OpenFOAM CFD Solver. Additionally Porous Medium properties such as Permeability (k) , Tortuosity (τ) will be also analyzed.

Development of a test method for protective gloves against nanoparticles in conditions simulating occupational use

NASA Astrophysics Data System (ADS)

Dolez, Patricia; Vinches, Ludwig; Wilkinson, Kevin; Plamondon, Philippe; Vu-Khanh, Toan

2011-07-01

Nanoparticle manufacture and use are in full expansion. The associated risks of occupational exposure raise large concerns due to their potential toxicity. Even if they stand as a last resort in the traditional occupational Health & Safety (H&S) risk management strategy, personal protective equipment (PPE) against nanoparticles are an absolute need in the context of precautionary principle advocated by H&S organizations worldwide. However no standard test method is currently available for evaluating the efficiency of PPE against nanoparticles, in particular in the case of gloves. A project is thus underway to develop a test method for measuring nanoparticle penetration through protective gloves in conditions simulating glove-nanoparticle occupational interaction. The test setup includes an exposure and a sampling chamber separated by a circular glove sample. A system of cylinders is used to deform the sample while it is exposed to nanoparticles. The whole system is enclosed in a glove box to ensure the operator safety during assembly, dismounting and clean-up operations as well as during the tests. Appropriate nanoparticle detection techniques were also identified. Results are reported here for commercial 15nm TiO2 nanoparticles - powder and colloidal solutions in 1,2-propanediol, ethylene glycol and water - and four types of protective gloves: disposable nitrile and latex as well as unsupported neoprene and butyl rubber gloves. They show that mechanical deformations and contact with colloidal solution liquid carriers may affect glove materials. Preliminary results obtained with TiO2 powder indicate a possible penetration of nanoparticles through gloves following mechanical deformations.

Universal penetration test apparatus with fluid penetration sensor

DOEpatents

Johnson, P.W.; Stampfer, J.F.; Bradley, O.D.

1999-02-02

A universal penetration test apparatus is described for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material. 23 figs.

FLiNaK Compatability Studies with Inconel 600 and Silicon Carbide

DOE PAGES

Yoder, Jr, Graydon L.; Heatherly, Dennis Wayne; Wilson, Dane F.; ...

2016-07-26

A small liquid fluoride salt test apparatus has been constructed and testing conducted to examine the compatibility of SiC, Inconel 600, and a spiral wound gasket material in FLiNaK salt. These tests were conducted to test materials and sealing systems that would be used in a FLiNaK salt test loop. Three months of testing at 700oC was used to assure that these materials and seals would be acceptable operating under expected test loop conditions. The SiC specimens showed little or no change over the test period while the spiral wound gasket material showed no degradation, except for the possibility ofmore » salt seeping into the outermost spirals of the gasket. The Inconel 600 specimens showed regions of voiding which penetrated the specimen surface to about 250 m in depth. Analysis indicated that the salt had leached chrome from the Inconel surface as was expected for this material. Because the test loop will have a limited working lifetime, it was concluded that these materials would be satisfactory for loop construction.« less

Penetration and decontamination of americium-241 ex vivo using fresh and frozen pig skin.

PubMed

Tazrart, A; Bolzinger, M A; Moureau, A; Molina, T; Coudert, S; Angulo, J F; Briancon, S; Griffiths, N M

2017-04-01

Skin contamination is one of the most probable risks following major nuclear or radiological incidents. However, accidents involving skin contamination with radionuclides may occur in the nuclear industry, in research laboratories and in nuclear medicine departments. This work aims to measure the penetration of the radiological contaminant Americium ( 241 Am) in fresh and frozen skin and to evaluate the distribution of the contamination in the skin. Decontamination tests were performed using water, Fuller's earth and diethylene triamine pentaacetic acid (DTPA), which is the recommended treatment in case of skin contamination with actinides such as plutonium or americium. To assess these parameters, we used the Franz cell diffusion system with full-thickness skin obtained from pigs' ears, representative of human skin. Solutions of 241 Am were deposited on the skin samples. The radioactivity content in each compartment and skin layers was measured after 24 h by liquid scintillation counting and alpha spectrophotometry. The Am cutaneous penetration to the receiver compartment is almost negligible in fresh and frozen skin. Multiple washings with water and DTPA recovered about 90% of the initial activity. The rest remains fixed mainly in the stratum corneum. Traces of activity were detected within the epidermis and dermis which is fixed and not accessible to the decontamination. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Laboratory simulation of intact capture of cometary and asteroidal dust particles in ISAS

NASA Technical Reports Server (NTRS)

Fujiwara, A.; Nakamura, A.; Kadono, T.

1994-01-01

In order to develop a collector for intact capturing of cometary dust particles in the SOCCER mission and regolith dust particles released from asteroid surfaces by the impact of projectiles launched from a flying-by spacecraft, various kinds of materials as the collector candidates have been exposed to hypervelocity projectiles in our laboratory. Data based on the penetration characteristics of various materials (penetration depth, hole profile, effectiveness for intact capturing) are greatly increased. The materials tested for these simulation experiments include various kinds of low-density media and multisheet stacks; these are foamed plastics (polystyrene 0.01 g/cc), silica aerogels (0.04 g/cc), air (0.001 g/cc), liquid, and multisheet stack consisting of thin Al sheets (thickness 0.002 to 0.1 mm) or polyethylene sheets. Projectiles used are spheres or cylinders of nylon, polycarbonate, basalt, copper, iron, and volatile organics (e.g.,paradichlorobenzene) of size ranging from 30 micrometers to 1 cm launched by a two-stage light gas gun and a rail gun in ISAS at velocity up to about 7 km/s. Some results obtained by using nylon projectiles of velocity less than about 5 km/s are presented; the penetration depth vs. bulk density of the collector material for several kinds of materials and the velocity at which the projectiles begin to fragment vs. material density for foamed polystyrene.

Hydrophobization and antimicrobial activity of chitosan and paper-based packaging material.

PubMed

Bordenave, Nicolas; Grelier, Stephane; Coma, Veronique

2010-01-11

This study reports the elaboration of water-resistant, antimicrobial, chitosan and paper-based materials as environmentally friendly food packaging materials. Two types of papers were coated with chitosan-palmitic acid emulsions or with a blend of chitosan and O,O'-dipalmitoylchitosan (DPCT). Micromorphology studies showed that inclusion of hydrophobic compounds into the chitosan matrix was enhanced by grafting them onto chitosan and that this led to their penetration of the paper's core. Compared to chitosan-coated papers, the coating of chitosan-palmitic emulsion kept vapor-barrier properties unchanged (239 and 170 g.m(-2).d(-1) versus 241 and 161 g.m(-2).d(-1)), while the coating of chitosan-DPCT emulsion dramatically deteriorated them (441 and 442 g.m(-2).d(-1)). However, contact angle measurements (110-120 degrees after 1 min) and penetration dynamics analysis showed that both strategies improved liquid-water resistance of the materials. Kit-test showed that all hydrophobized chitosan-coated papers kept good grease barrier properties (degree of resistance 6-8/12). Finally, all chitosan-coated materials exhibited over 98% inhibition on Salmonella Typhimurium and Listeria monocytogenes .

A Highly Sensitive Assay Using Synthetic Blood Containing Test Microbes for Evaluation of the Penetration Resistance of Protective Clothing Material under Applied Pressure.

PubMed

Shimasaki, Noriko; Hara, Masayuki; Kikuno, Ritsuko; Shinohara, Katsuaki

2016-01-01

To prevent nosocomial infections caused by even either Ebola virus or methicillin-resistant Staphylococcus aureus (MRSA), healthcare workers must wear the appropriate protective clothing which can inhibit contact transmission of these pathogens. Therefore, it is necessary to evaluate the performance of protective clothing for penetration resistance against infectious agents. In Japan, some standard methods were established to evaluate the penetration resistance of protective clothing fabric materials under applied pressure. However, these methods only roughly classified the penetration resistance of fabrics, and the detection sensitivity of the methods and the penetration amount with respect to the relationship between blood and the pathogen have not been studied in detail. Moreover, no standard method using bacteria for evaluation is known. Here, to evaluate penetration resistance of protective clothing materials under applied pressure, the detection sensitivity and the leak amount were investigated by using synthetic blood containing bacteriophage phi-X174 or S. aureus. And the volume of leaked synthetic blood and the amount of test microbe penetration were simultaneously quantified. Our results showed that the penetration detection sensitivity achieved using a test microbial culture was higher than that achieved using synthetic blood at invisible leak level pressures. This finding suggested that there is a potential risk of pathogen penetration even when visual leak of contaminated blood through the protective clothing was not observed. Moreover, at visible leak level pressures, it was found that the amount of test microbe penetration varied at least ten-fold among protective clothing materials classified into the same class of penetration resistance. Analysis of the penetration amount revealed a significant correlation between the volume of penetrated synthetic blood and the amount of test microbe penetration, indicating that the leaked volume of synthetic blood could be considered as a latent indicator for infection risk, that the amount of exposure to contaminated blood corresponds to the risk of infection. Our study helped us ascertain, with high sensitivity, the differences among fabric materials with respect to their protective performance, which may facilitate effective selection of protective clothing depending on the risk assessment.

Cryobot: an ice penetrating robotic vehicle for Mars and Europa

NASA Technical Reports Server (NTRS)

Zimmerman, W. F.; Bonitz, R.; Feldman, J.

2001-01-01

This paper describes the science driven requirements for a robotic vehicle, which utilizes gravity, and both passive and active heating systems to drive ice to a liquid phase change state, in order to facilitate mobility.

Control of rabbit dura mater optical properties with osmotical liquids

NASA Astrophysics Data System (ADS)

Yao, Lei; Cheng, Haiying; Luo, Qingming; Zhang, Wei; Zeng, Shaoqun; Tuchin, Valery V.

2002-04-01

An experimental study of controlling the optical properties of in vitro and in vivo rabbit dura mater with administration of osmotical agents, 40% glucose solution and glycerol, using video camera and spectrometer was presented. The preliminary results of experimental study of influence of osmotical liquids (glucose solutions, glycerol) on transmittance (in vitro) and reflectance (in vivo) spectra of rabbit dura mater were reported. The significant decreasing of the reflectance and increasing of the transmittance of dura mater under action of osmotical solutions were demonstrated. Experiments showed that administration of osmolytes to dura mater allowed for effective and temporary control of its optical characteristics, which made dura mater more transparent, increased the ability of light penetrating the tissue, and consequently improved the optical imaging depth. It is a significant study, which can improve penetration of optical imaging of cerebral function and acquire more information of the deep brain tissue.

Evaluation of cone penetration testing (CPT) for use with transportation projects.

DOT National Transportation Integrated Search

2011-04-01

Cone Penetration Testing (CPT) has many advantages as a means for subsurface investigation. CPT consists of pushing a steel : cone into the ground and recording the penetration resistance using sensors. Pore pressure, shear wave velocity and other : ...

Airborne concentrations of benzene associated with the historical use of some formulations of liquid wrench.

PubMed

Williams, Pamela R D; Knutsen, Jeffrey S; Atkinson, Chris; Madl, Amy K; Paustenbach, Dennis J

2007-08-01

The current study characterizes potential inhalation exposures to benzene associated with the historical use of some formulations of Liquid Wrench under specific test conditions. This product is a multiuse penetrant and lubricant commonly used in a variety of consumer and industrial settings. The study entailed the remanufacturing of several product formulations to have similar physical and chemical properties to most nonaerosol Liquid Wrench formulations between 1960 and 1978. The airborne concentrations of benzene and other constituents during the simulated application of these products were measured under a range of conditions. Nearly 200 breathing zone and area bystander air samples were collected during 11 different product use scenarios. Depending on the tests performed, average airborne concentrations of benzene ranged from approximately 0.2-9.9 mg/m(3) (0.08-3.8 ppm) for the 15-min personal samples; 0.1-8 mg/m(3) (0.04-3 ppm) for the 1-hr personal samples; and 0.1-5.1 mg/m(3) (0.04-2 ppm) for the 1-hr area samples. The 1-hr personal samples encompassed two 15-min product applications and two 15-min periods of standing within 5 to 10 feet of the work area. The measured airborne concentrations of benzene varied significantly based on the benzene content of the formulation tested (1%, 3%, 14%, or 30% v/v benzene) and the indoor air exchange rate but did not vary much with the base formulation of the product or the two quantities of Liquid Wrench used. The airborne concentrations of five other volatile chemicals (ethylbenzene, toluene, total xylenes, cyclohexane, and hexane) were also measured, and the results were consistent with the volatility and concentrations of these chemicals in the product tested. A linear regression analysis of air concentration compared with the chemical mole fraction in the solution and air exchange rate provided a relatively good fit to the data. The results of this study should be useful for evaluating potential inhalation exposures to benzene and other volatile chemicals that occurred during the past use of some formulations of Liquid Wrench and perhaps for some similar products containing these chemicals.

Unsteady penetration of a target by a liquid jet

PubMed Central

Uth, Tobias; Deshpande, Vikram S.

2013-01-01

It is widely acknowledged that ceramic armor experiences an unsteady penetration response: an impacting projectile may erode on the surface of a ceramic target without substantial penetration for a significant amount of time and then suddenly start to penetrate the target. Although known for more than four decades, this phenomenon, commonly referred to as dwell, remains largely unexplained. Here, we use scaled analog experiments with a low-speed water jet and a soft, translucent target material to investigate dwell. The transient target response, in terms of depth of penetration and impact force, is captured using a high-speed camera in combination with a piezoelectric force sensor. We observe the phenomenon of dwell using a soft (noncracking) target material. The results show that the penetration rate increases when the flow of the impacting water jet is reversed due to the deformation of the jet–target interface––this reversal is also associated with an increase in the force exerted by the jet on the target. Creep penetration experiments with a constant indentation force did not show an increase in the penetration rate, confirming that flow reversal is the cause of the unsteady penetration rate. Our results suggest that dwell can occur in a ductile noncracking target due to flow reversal. This phenomenon of flow reversal is rather widespread and present in a wide range of impact situations, including water-jet cutting, needleless injection, and deposit removal via a fluid jet. PMID:24277818

Magma Energy Research, 79-1. Semiannual report, October 1, 1978-March 31, 1979

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

Traeger, R.K.; Colp, J.L.; Neel, R.R.

1979-07-01

A major effort in evaluating Kilauea Iki lava lake has been completed. The physical model based on FY 76 geophysical experiments is not correct in that a low viscosity, liquid lens of appreciable thickness does not exist. Mathematical models of the cooling of the lava lake and the state of solidification of the liquid lens were verified by thermal profile and permeability measurements. New jet-augmented drilling concepts successfully penetrated the viscous, multi-phase molten rock region in some locations where conventional drilling failed. Heat transfer studies in the lake suggest injection of fluids to enhance convection may be useful to extractmore » energy from magma chamber margins. Other activities resulted in the completion and successful testing of a 800 cc simulation facility for evaluating simulated magma properties at temperatures to 1500/sup 0/C and pressures to 4 kbar. In materials compatibility studies, thermodynamic stability diagrams were developed for 15 pure metals in basaltic magma systems and compatibility tests completed. Results are being used to define simple alloy systems which may be compatible with magmas and to identify other superalloy materials candidates.« less

The Rehbinder effect in iron during giga-cycle fatigue loading

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

Bannikov, M. V., E-mail: mbannikov@icmm.ru; Naimark, O. B.

The influence of the adsorptive strength reduction effect (the Rehbinder effect) on the fatigue life of pure iron under the giga-cycle loading regime was investigated. Specimens were loaded by an ultrasonic testing machine with a frequency of 20 kHz in air and in contact with eutectic alloy of gallium with tin and indium. A significant (by several orders of magnitude) worsening of the life-time of iron in contact with a molten metal as compared with tests in air was established. The liquid metal penetrates into the material to a depth of 200 μm to the center of a fatigue crack. Themore » mechanism of the fatigue crack initiation in the giga-cycle regime of loading in contact with a surfactant is differing: the crack is formed on the surface of the specimen rather than within it as is the case for air. Based on the electron and optical microscopy data for the fracture surface, it can be concluded that exactly the change in the crack initiation mechanism reduces the fatigue life of iron in contact with a liquid metal because the initiated crack propagates regardless of the surfactant.« less

The Rehbinder effect in iron during giga-cycle fatigue loading

NASA Astrophysics Data System (ADS)

Bannikov, M. V.; Naimark, O. B.

2015-10-01

The influence of the adsorptive strength reduction effect (the Rehbinder effect) on the fatigue life of pure iron under the giga-cycle loading regime was investigated. Specimens were loaded by an ultrasonic testing machine with a frequency of 20 kHz in air and in contact with eutectic alloy of gallium with tin and indium. A significant (by several orders of magnitude) worsening of the life-time of iron in contact with a molten metal as compared with tests in air was established. The liquid metal penetrates into the material to a depth of 200 μm to the center of a fatigue crack. The mechanism of the fatigue crack initiation in the giga-cycle regime of loading in contact with a surfactant is differing: the crack is formed on the surface of the specimen rather than within it as is the case for air. Based on the electron and optical microscopy data for the fracture surface, it can be concluded that exactly the change in the crack initiation mechanism reduces the fatigue life of iron in contact with a liquid metal because the initiated crack propagates regardless of the surfactant.

A computer-controlled apparatus for micrometric drop deposition at liquid surfaces

NASA Astrophysics Data System (ADS)

Peña-Polo, Franklin; Trujillo, Leonardo; Sigalotti, Leonardo Di G.

2010-05-01

A low-cost, automated apparatus has been used to perform micrometric deposition of small pendant drops onto a quiet liquid surface. The approach of the drop to the surface is obtained by means of discrete, micron-scale translations in order to achieve deposition at adiabatically zero velocity. This process is not only widely used in scientific investigations in fluid mechanics and thermal sciences but also in engineering and biomedical applications. The apparatus has been designed to produce accurate deposition onto the surface and minimize the vibrations induced in the drop by the movement of the capillary tip. Calibration tests of the apparatus have shown that a descent of the drop by discrete translational steps of ˜5.6 μm and duration of 150-200 ms is sufficient to minimize its penetration depth into the liquid when it touches the surface layer and reduce to a level of noise the vibrations transmitted to it by the translation of the dispenser. Different settings of the experimental setup can be easily implemented for use in a variety of other applications, including deposition onto solid surfaces, surface tension measurements of pendant drops, and wire bonding in microelectronics.

Modeling of light dynamic cone penetration test - Panda 3 ® in granular material by using 3D Discrete element method

NASA Astrophysics Data System (ADS)

Tran, Quoc Anh; Chevalier, Bastien; Benz, Miguel; Breul, Pierre; Gourvès, Roland

2017-06-01

The recent technological developments made on the light dynamic penetration test Panda 3 ® provide a dynamic load-penetration curve σp - sp for each impact. This curve is influenced by the mechanical and physical properties of the investigated granular media. In order to analyze and exploit the load-penetration curve, a numerical model of penetration test using 3D Discrete Element Method is proposed for reproducing tests in dynamic conditions in granular media. All parameters of impact used in this model have at first been calibrated by respecting mechanical and geometrical properties of the hammer and the rod. There is a good agreement between experimental results and the ones obtained from simulations in 2D or 3D. After creating a sample, we will simulate the Panda 3 ®. It is possible to measure directly the dynamic load-penetration curve occurring at the tip for each impact. Using the force and acceleration measured in the top part of the rod, it is possible to separate the incident and reflected waves and then calculate the tip's load-penetration curve. The load-penetration curve obtained is qualitatively similar with that obtained by experimental tests. In addition, the frequency analysis of the measured signals present also a good compliance with that measured in reality when the tip resistance is qualitatively similar.

Evaluation of the filtration performance of NIOSH-approved N95 filtering facepiece respirators by photometric and number-based test methods.

PubMed

Rengasamy, Samy; Miller, Adam; Eimer, Benjamin C

2011-01-01

N95 particulate filtering facepiece respirators are certified by measuring penetration levels photometrically with a presumed severe case test method using charge neutralized NaCl aerosols at 85 L/min. However, penetration values obtained by photometric methods have not been compared with count-based methods using contemporary respirators composed of electrostatic filter media and challenged with both generated and ambient aerosols. To better understand the effects of key test parameters (e.g., particle charge, detection method), initial penetration levels for five N95 model filtering facepiece respirators were measured using NaCl aerosols with the aerosol challenge and test equipment employed in the NIOSH respirator certification method (photometric) and compared with an ultrafine condensation particle counter method (count based) for the same NaCl aerosols as well as for ambient room air particles. Penetrations using the NIOSH test method were several-fold less than the penetrations obtained by the ultrafine condensation particle counter for NaCl aerosols as well as for room particles indicating that penetration measurement based on particle counting offers a more difficult challenge than the photometric method, which lacks sensitivity for particles < 100 nm. All five N95 models showed the most penetrating particle size around 50 nm for room air particles with or without charge neutralization, and at 200 nm for singly charged NaCl monodisperse particles. Room air with fewer charged particles and an overwhelming number of neutral particles contributed to the most penetrating particle size in the 50 nm range, indicating that the charge state for the majority of test particles determines the MPPS. Data suggest that the NIOSH respirator certification protocol employing the photometric method may not be a more challenging aerosol test method. Filter penetrations can vary among workplaces with different particle size distributions, which suggests the need for the development of new or revised "more challenging" aerosol test methods for NIOSH certification of respirators.

A novel drug delivery gel of terbinafine hydrochloride with high penetration for external use.

PubMed

Yang, Yan; Ou, Rujing; Guan, Shixia; Ye, Xiaoling; Hu, Bo; Zhang, Yi; Lu, Shufan; Zhou, Yubin; Yuan, Zhongwen; Zhang, Jun; Li, Qing-Guo

2015-12-01

Terbinafine hydrochloride is an antifungal drug for onychomycosis. Poor permeability of its external preparation leads to poor curative effect. Transfersomes, also known as flexible liposome, could improve transmission of drug for local external use. Terbinafine hydrochloride-loaded liposome is expected to become a breakthrough on the treatment of onychomycosis. This study is aimed to prepare high skin penetration terbinafine hydrochloride transfersomes with high encapsulation efficiency, appropriate drug loading and good stability. Taking entrapment efficiency as the main indicator, the formulations and the processes of preparation were investigated. Transfersomes with different surfactants were prepared in the optimization processes, and the formulations were optimized through the transdermal test in vitro. As a result, a gel contained transfersomes was obtained with a brief evaluation. Its pharmacokinetic properties of going through the skin were studied by using the micro dialysis technology and liquid chromatography-mass spectrometry to assay the penetration behavior of terbinafine. Mean particle size of the terbinafine hydrochloride transfersomes was 69.6 ± 1.23 nm, and the entrapment efficiency was 95.4% ± 0.51. The content of the gel was 4.45 ± 0.15 mg/g. The accumulated permeation of the transfersomes gel in 12 h was 88.52 ± 4.06 µg cm -2 and the intracutaneous drug detention was 94.38 ± 5.26 µg cm -2 . The results of pharmacokinetic studies showed the C max and area under the curve (AUC) were apparently higher than the commercial cream. The terbinafine hydrochloride transfersomes was highly absorbed by the skin. The absorption rate was significantly higher than that of the commercial cream either in the transdermal test in vitro or in the pharmacokinetic studies in vivo.

Toward jet injection by continuous-wave laser cavitation.

PubMed

Berrospe-Rodriguez, Carla; Visser, Claas Willem; Schlautmann, Stefan; Rivas, David Fernandez; Ramos-Garcia, Ruben

2017-10-01

This is a study motivated by the need to develop a needle-free device for eliminating major global healthcare problems caused by needles. The generation of liquid jets by means of a continuous-wave laser, focused into a light absorbing solution, was studied with the aim of developing a portable and affordable jet injector. We designed and fabricated glass microfluidic devices, which consist of a chamber where thermocavitation is created and a tapered channel. The growth of a vapor bubble displaces and expels the liquid through the channel as a fast traveling jet. Different parameters were varied with the purpose of increasing the jet velocity. The velocity increases with smaller channel diameters and taper ratios, whereas larger chambers significantly reduce the jet speed. It was found that the initial position of the liquid-air meniscus interface and its dynamics contribute to increased jet velocities. A maximum velocity of 94±3  m/s for a channel diameter of D=120  μm, taper ratio n=0.25, and chamber length E=200  μm was achieved. Finally, agarose gel-based skin phantoms were used to demonstrate the potential of our devices to penetrate the skin. The maximum penetration depth achieved was ∼1  mm, which is sufficient to penetrate the stratum corneum and for most medical applications. A meta-analysis shows that larger injection volumes will be required as a next step to medical relevance for laser-induced jet injection techniques in general. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

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

Surface penetrators for planetary exploration: Science rationale and development program

NASA Technical Reports Server (NTRS)

Murphy, J. P.; Reynolds, R. T.; Blanchard, M. B.; Clanton, U. S.

1981-01-01

Work on penetrators for planetary exploration is summarized. In particular, potential missions, including those to Mars, Mercury, the Galilean satellites, comets, and asteroids are described. A baseline penetrator design for the Mars mission is included, as well as potential instruments and their status in development. Penetration tests in soft soil and basalt to study material eroded from the penetrator; changes in the structure, composition, and physical properties of the impacted soil; seismic coupling; and penetrator deflection caused by impacting rocks, are described. Results of subsystem studies and tests are given for design of entry decelerators, high-g components, thermal control, data acquisition, and umbilical cable deployment.

Penetration of Ufenamate into Intact, Stripped, or Delipidized Skin Using Different Vehicles.

PubMed

Iino, Hayato; Fujii, Makiko; Fujino, Manami; Koizumi, Naoya; Watanabe, Yoshiteru

2015-01-01

The purpose of this study was to clarify the effect of skin condition on skin penetration of the very high lipophilic drug, ufenamate (UF). UF was applied to stripped or delipidized skin using liquid paraffin (LP) or purified water containing polysorbate 80 at a dose of 2 µL/cm(2). We found that UF penetration into intact and stripped skin using a water vehicle was respectively 5 and 10 times higher than that using LP. UF is freely soluble in oil and insoluble in water; thus, activity in water is higher than that in LP. Therefore, it is useful to use a water-based vehicle for both intact sites and those with defective stratum corneum (SC). Conversely, we found that delipidization of SC decreased the penetration of UF significantly with both LP and water, and the amount measured in the epidermis was 1 µg/cm(2) with both vehicles. This indicates that UF is not suitable for so-called "dry skin." This study revealed clinically relevant differences in the penetration of UF into intact, stripped, or delipidized skin conditions.

Atomization of liquid fuels. Part I

NASA Technical Reports Server (NTRS)

Kuehn,

1925-01-01

In the present treatise we will consider chiefly the problem of solid injection in comparison with air injection. On leaving the valve or nozzle through one or more small openings, the fuel is split up into innumerable fine drops, which penetrate the combustion chamber in divergent directions in the form of a conical jet. The efficiency of this jet is judged from the following three viewpoints: 1) with respect to the fineness of atomization; 2) with respect to the direction or distribution of sprayed particles; 3) with respect to the penetration of the particles.

Electrowetting-based adaptive vari-focal liquid lens array for 3D display

NASA Astrophysics Data System (ADS)

Won, Yong Hyub

2014-10-01

Electrowetting is a phenomenon that can control the surface tension of liquid when a voltage is applied. This paper introduces the fabrication method of liquid lens array by the electrowetting phenomenon. The fabricated 23 by 23 lens array has 1mm diameter size with 1.6 mm interval distance between adjacent lenses. The diopter of each lens was - 24~27 operated at 0V to 50V. The lens array chamber fabricated by Deep Reactive-Ion Etching (DRIE) is deposited with IZO and parylene C and tantalum oxide. To prevent water penetration and achieve high dielectric constant, parylene C and tantalum oxide (ɛ = 23 ~ 25) are used respectively. Hydrophobic surface which enables the range of contact angle from 60 to 160 degree is coated to maximize the effect of electrowetting causing wide band of dioptric power. Liquid is injected into each lens chamber by two different ways. First way was self water-oil dosing that uses cosolvent and diffusion effect, while the second way was micro-syringe by the hydrophobic surface properties. To complete the whole process of the lens array fabrication, underwater sealing was performed using UV adhesive that does not dissolve in water. The transient time for changing from concave to convex lens was measured <33ms (at frequency of 1kHz AC voltage.). The liquid lens array was tested unprecedentedly for integral imaging to achieve more advanced depth information of 3D image.

Comparative intraocular penetration of 4 fluoroquinolones after topical instillation.

PubMed

Chung, Jae Lim; Lim, Eun Hye; Song, Sang Wroul; Kim, Byung Yeop; Lee, Joon H; Mah, Francis S; Seo, Kyoung Yul

2013-07-01

To compare the intraocular penetration of 4 fluoroquinolone eye drops after topical instillation into rabbit eyes. The tested drugs were levofloxacin 1.5% (LVFX), gatifloxacin 0.3%, moxifloxacin 0.5% (MFLX), and besifloxacin 0.6% (BFLX). Forty-eight New Zealand white rabbits were randomly assigned into 2 groups. For group 1 (40 rabbits, 80 eyes), single instillation was performed, and tissue samples were acquired after 0.5, 1, 2, 4, and 6 hours. For group 2 (8 rabbits, 16 eyes), repeated instillation was performed (4 times, every 15 minutes), and tissues were acquired 1 hour after the fourth instillation. The drug concentrations in ocular tissues (cornea, aqueous, conjunctiva, and trisected vitreous) were analyzed with high-performance liquid chromatography. The AUC 0-6 h (area under the curve, in microgram.hour/gram) in group 1 and the mean concentration (in micrograms/gram) in group 2 for LVFX, gatifloxacin 0.3%, MFLX, and BFLX, respectively, were 22.97, 6.44, 13.54, and 3.29 and 22.60, 6.99, 13.69, and 1.91 in cornea; 5.66, 1.43, 3.38, and 0.42 and 5.52, 1.29, 2.47, and 0.19 in aqueous humor; 2.33, 0.91, 2.17, and 9.83 and 4.51, 0.78, 1.48, and 2.09 in bulbar conjunctiva; 0.243, 0.051, 0.134, and 0.018 and 0.182, 0.055, 0.122, and 0.015 in anterior vitreous; none of the drugs achieved enough concentration in equatorial and posterior vitreous. Repeated instillation resulted in approximately 2.1 times greater penetration than single instillation. LVFX and MFLX demonstrated good intraocular penetration particularly in cornea, aqueous humor, and anterior vitreous, and they may be considered the penetrative fluoroquinolones. BFLX showed high concentration in bulbar conjunctiva and may be considered the retentive fluoroquinolone.

Design and Development of a Composite Dome for Experimental Characterization of Material Permeability

NASA Technical Reports Server (NTRS)

Estrada, Hector; Smeltzer, Stanley S., III

1999-01-01

This paper presents the design and development of a carbon fiber reinforced plastic dome, including a description of the dome fabrication, method for sealing penetrations in the dome, and a summary of the planned test series. This dome will be used for the experimental permeability characterization and leakage validation of composite vessels pressurized using liquid hydrogen and liquid nitrogen at the Cryostat Test Facility at the NASA Marshall Space Flight Center (MSFC). The preliminary design of the dome was completed using membrane shell analysis. Due to the configuration of the test setup, the dome will experience some flexural stresses and stress concentrations in addition to membrane stresses. Also, a potential buckling condition exists for the dome due to external pressure during the leak testing of the cryostat facility lines. Thus, a finite element analysis was conducted to assess the overall strength and stability of the dome for each required test condition. Based on these results, additional plies of composite reinforcement material were applied to local regions on the dome to alleviate stress concentrations and limit deflections. The dome design includes a circular opening in the center for the installation of a polar boss, which introduces a geometric discontinuity that causes high stresses in the region near the hole. To attenuate these high stresses, a reinforcement system was designed using analytical and finite element analyses. The development of a low leakage polar boss system is also investigated.

Human skin absorption of Bis-2-(chloroethyl)sulphide (sulphur mustard) in vitro.

PubMed

Chilcott, R P; Jenner, J; Carrick, W; Hotchkiss, S A; Rice, P

2000-01-01

The purpose of this study was to measure the absorption and intra-epidermal fate of 35S-radiolabelled sulphur mustard (35SM) in human breast skin in vitro. Skin (full-thickness or heat-separated epidermis) was placed into static diffusion cells and was exposed to droplets of liquid 35SM or saturated 35SM vapour. Amounts of 35SM penetrating the skin were measured from which skin absorption rates were calculated. Unbound radiolabel was washed from the surface, extracted from the skin and analysed to determine the identity of the radiolabelled species in order to measure the extent of hydrolysis of sulphur mustard. Penetration rates of liquid 35SM measured in vitro (71-294 microg cm(-2) h(-1)) were in agreement with those measured previously in vivo using human volunteers (60-240 microg cm(-2) h(-1)). Rates of liquid 35SM skin absorption under occluded, infinite dose conditions were highest through heat-separated epidermal membranes (294+/-58 microg cm(-2) h(-1)) and lowest through full-thickness skin (71+/-14 microg cm(-2) h(-1)). Fluxes of saturated 35SM vapour (110+/-75 microg cm(-2) h(-1)) through heat-separated membranes were similar to those previously measured through human forearm skin in vivo (162 microg cm(-2) h(-1)). Although hydrolysis of 35SM did occur, both on the surface and within the skin, it accounted for only a small percentage of the total applied dose (<2.7+/-1.2%). The difference in total amount of liquid 35SM penetrated between occluded and unoccluded conditions in vitro (79+/-14%) was similar to that lost as vapour from unoccluded skin in vivo (80%). A substantial reservoir of 35SM (14-36% of the applied dose) was measured within heat-separated epidermal membranes for up to 24 h which may have significant implications for the management of personnel exposed to sulphur mustard.

A Comparative Study Between Modified Starch and Xanthan Gum Thickeners in Post-Stroke Oropharyngeal Dysphagia.

PubMed

Vilardell, N; Rofes, L; Arreola, V; Speyer, R; Clavé, P

2016-04-01

Thickeners are used in post-stroke oropharyngeal dysphagia (OD) as a compensatory therapeutic strategy against aspirations. To compare the therapeutic effects of modified starch (MS) and xanthan gum (XG) thickeners on swallow safety and efficacy in chronic post-stroke OD patients using clinical and videofluoroscopic (VFS) assessment. Patients were studied by clinical assessment (volume-viscosity swallow test, V-VST) and VFS using 3 volumes (5, 10, 20 mL) and 3 viscosities (liquid, nectar and spoon thick), comparing MS and XG. We studied 122 patients (46MS, 76XG). (A) V-VST showed that both thickeners similarly improved safety of swallow. Prevalence of safe swallowing significantly increased with enhanced viscosity (P < 0.001 vs liquid), MS: 47.83 % at liquid, 84.93 % at nectar and 92.96 % at spoon thick; XG: 55.31 % at liquid, 77.78 % at nectar and 97.84 % at spoon thick. Patients on MS reported higher prevalence of pharyngeal residue at spoon-thick viscosities. (B) VFS: increasing bolus viscosity with either thickener increased prevalence of safe swallows (P < 0.001 vs liquid), MS: 30.25 % liquid, 61.07 % nectar and 92.64 % spoon thick; XG: 29.12 % liquid, 71.30 % nectar and 89.91 % spoon thick. Penetration-aspiration scale score was significantly reduced with increased viscosity with both thickeners. MS increased oral and pharyngeal residues at nectar and spoon-thick viscosities but XG did not. Timing of airway protection mechanisms and bolus velocity were not affected by either thickener. Increasing bolus viscosity with MS and XG thickeners strongly and similarly improved safety of swallow in chronic post-stroke OD by a compensatory mechanism; in contrast only MS thickeners increased oropharyngeal residue.

Modulating interactions between ligand-coated nanoparticles and phase-separated lipid bilayers by varying the ligand density and the surface charge.

PubMed

Chen, Xiaojie; Tieleman, D Peter; Liang, Qing

2018-02-01

The interactions between nanoparticles and lipid bilayers are critical in applications of nanoparticles in nanomedicine, cell imaging, toxicology, and elsewhere. Here, we investigate the interactions between nanoparticles coated with neutral and/or charged ligands and phase-separated lipid bilayers using coarse-grained molecular dynamics simulation. Both penetration and adsorption processes as well as the final distribution of the nanoparticles can be readily modulated by varying the ligand density and the surface charge of the nanoparticles. Completely hydrophobic (neutral) nanoparticles with larger size initially preferentially penetrate into the liquid-disordered region of the lipid bilayer and finally transfer into the liquid-ordered region; partially hydrophilic nanoparticles with low or moderate surface charge tend to either distribute in the liquid-disordered region or be adsorbed on the surface of the lipid bilayer, while strongly hydrophilic nanoparticles with high surface charge always reside on the surface of the lipid bilayer. Interactions of the nanoparticles with the lipid bilayers are affected by the surface charge of nanoparticles, hydrophobic mismatch, bending of the ligands, and the packing state of the lipids. Insight in these factors can be used to improve the efficiency of designing nanoparticles for specific applications.

Liquid and Solid Metal Embrittlement.

DTIC Science & Technology

1981-09-05

example, embrittlement of AISI 4140 steel begins at T/T, - 0.75 for cadmium, and 0.85 for lead and tin environments (2). In a few cases, e.g. zinc...has recently proposed, however, that liquid zinc can penetrate to very near the tip of a sharp crack in 4140 steel, based upon both direct observation...long could be detected, was observed in delayed failure experi- ments on unnotched 4140 steel, in the quenched and tempered condi- tion, embrittled by

Ordering Transitions in Liquid Crystals Permit Imaging of Spatial and Temporal Patterns Formed by Proteins Penetrating into Lipid-Laden Interfaces

PubMed Central

Daschner De Tercero, Maren; Abbott, Nicholas L.

2013-01-01

Recent studies have reported that full monolayers of L-α-dilaurylphosphatidylcholine (L-DLPC) and D-α-dipalmitoylphosphatidylcholine (D-DPPC) formed at interfaces between thermotropic liquid crystals (LCs) and aqueous phases lead to homeotropic (perpendicular) orientations of nematic LCs and that specific binding of proteins to these interfaces (such as phospholipase A2 binding to D-DPPC) can trigger orientational ordering transitions in the liquid crystals. We report on the nonspecific interactions of proteins with aqueous-LC interfaces decorated with partial monolayer coverage of L-DLPC. Whereas nonspecific interactions of four proteins (cytochrome c, bovine serum albumin,immunoglobulins, and neutravidin) do not perturb the ordering of the LC when a full monolayer of L-DLPC is assembled at the aqueous-LC interface, we observe patterned orientational transitions in the LC that reflect penetration of proteins into the interface of the LC with partial monolayer coverage of L-DLPC. The spatial patterns formed by the proteins and lipids at the interface are surprisingly complex, and in some cases the protein domains are found to compartmentalize lipid within the interfaces. These results suggest that phospholipid-decorated interfaces between thermotropic liquid crystals and aqueous phases offer the basis of a simple and versatile tool to study the spatial organization and dynamics ofprotein networks formed at mobile, lipid-decorated interfaces. PMID:23671353

Liquid Crystalline Systems Based on Glyceryl Monooleate and Penetration Enhancers for Skin Delivery of Celecoxib: Characterization, In Vitro Drug Release, and In Vivo Studies.

PubMed

Dante, Mariane de Cássia Lima; Borgheti-Cardoso, Livia Neves; Fantini, Marcia Carvalho de Abreu; Praça, Fabíola Silva Garcia; Medina, Wanessa Silva Garcia; Pierre, Maria Bernadete Riemma; Lara, Marilisa Guimarães

2018-03-01

Celecoxib (CXB) is a widely used anti-inflammatory drug that also acts as a chemopreventive agent against several types of cancer, including skin cancer. As the long-term oral administration of CXB has been associated with severe side effects, the skin delivery of this drug represents a promising alternative for the treatment of skin inflammatory conditions and chemoprevention of skin cancer. We prepared and characterized liquid crystalline systems based on glyceryl monooleate and water containing penetration enhancers which were primarily designed to promote skin delivery of CXB. Analysis of their phase behavior revealed the formation of cubic and hexagonal phases depending on the systems' composition. The systems' structure and composition markedly affected the in vitro CXB release profile. Oleic acid reduced CXB release rate, but association oleic acid/propylene glycol increased the drug release rate. The developed systems significantly reduced inflammation in an aerosil-induced rat paw edema model. The systems' composition and liquid crystalline structure influenced their anti-inflammatory potency. Cubic phase systems containing oleic acid/propylene glycol association reduced edema in a sustained manner, indicating that they modulate CXB release and permeation. Our findings demonstrate that the developed liquid crystalline systems are potential carriers for the skin delivery of CXB. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Static penetration resistance of soils

NASA Technical Reports Server (NTRS)

Durgunoglu, H. T.; Mitchell, J. K.

1973-01-01

Model test results were used to define the failure mechanism associated with the static penetration resistance of cohesionless and low-cohesion soils. Knowledge of this mechanism has permitted the development of a new analytical method for calculating the ultimate penetration resistance which explicitly accounts for penetrometer base apex angle and roughness, soil friction angle, and the ratio of penetration depth to base width. Curves relating the bearing capacity factors to the soil friction angle are presented for failure in general shear. Strength parameters and penetrometer interaction properties of a fine sand were determined and used as the basis for prediction of the penetration resistance encountered by wedge, cone, and flat-ended penetrometers of different surface roughness using the proposed analytical method. Because of the close agreement between predicted values and values measured in laboratory tests, it appears possible to deduce in-situ soil strength parameters and their variation with depth from the results of static penetration tests.

Production of dissolvable microneedles using an atomised spray process: effect of microneedle composition on skin penetration.

PubMed

McGrath, Marie G; Vucen, Sonja; Vrdoljak, Anto; Kelly, Adam; O'Mahony, Conor; Crean, Abina M; Moore, Anne

2014-02-01

Dissolvable microneedles offer an attractive delivery system for transdermal drug and vaccine delivery. They are most commonly formed by filling a microneedle mold with liquid formulation using vacuum or centrifugation to overcome the constraints of surface tension and solution viscosity. Here, we demonstrate a novel microneedle fabrication method employing an atomised spray technique that minimises the effects of the liquid surface tension and viscosity when filling molds. This spray method was successfully used to fabricate dissolvable microneedles (DMN) from a wide range of sugars (trehalose, fructose and raffinose) and polymeric materials (polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylmethylcellulose and sodium alginate). Fabrication by spraying produced microneedles with amorphous content using single sugar compositions. These microneedles displayed sharp tips and had complete fidelity to the master silicon template. Using a method to quantify the consistency of DMN penetration into different skin layers, we demonstrate that the material of construction significantly influenced the extent of skin penetration. We demonstrate that this spraying method can be adapted to produce novel laminate-layered as well as horizontally-layered DMN arrays. To our knowledge, this is the first report documenting the use of an atomising spray, at ambient, mild processing conditions, to create dissolvable microneedle arrays that can possess novel, laminate layering. Copyright © 2013 Elsevier B.V. All rights reserved.

Piezocone Penetration Testing Device

DOT National Transportation Integrated Search

2017-01-03

Hydraulic characteristics of soils can be estimated from piezocone penetration test (called PCPT hereinafter) by performing dissipation test or on-the-fly using advanced analytical techniques. This research report presents a method for fast estimatio...

Fluconazole penetration in cerebral parenchyma in humans at steady state.

PubMed Central

Thaler, F; Bernard, B; Tod, M; Jedynak, C P; Petitjean, O; Derome, P; Loirat, P

1995-01-01

We studied fluconazole penetration in the brain in five patients who had a deep cerebral tumor whose removal required the excision of healthy brain tissue. Plasma and brain samples were simultaneously obtained after oral ingestion of 400 mg of fluconazole daily for 4 days (90% of steady state). Fluconazole penetration in healthy cerebral parenchyma was determined. Plasma and brain samples were assayed by high-pressure liquid chromatography. Concentrations in plasma and brain tissue were 13.5 +/- 5.5 micrograms/ml and 17.6 +/- 6.6 micrograms/g, respectively. The average ratio of concentrations in the brain and plasma (four patients) was 1.33 (range, 0.70 to 2.39). Despite the lack of data concerning the penetration of fluconazole in brain abscesses, these results should permit the use of a daily dose of 400 mg of fluconazole in prospective clinical studies that evaluate the effectiveness of this drug in the treatment of brain abscesses due to susceptible species of fungi. PMID:7625804

Liquid sprays and flow studies in the direct-injection diesel engine under motored conditions

NASA Technical Reports Server (NTRS)

Nguyen, Hung Lee; Carpenter, Mark H.; Ramos, Juan I.; Schock, Harold J.; Stegeman, James D.

1988-01-01

A two dimensional, implicit finite difference method of the control volume variety, a two equation model of turbulence, and a discrete droplet model were used to study the flow field, turbulence levels, fuel penetration, vaporization, and mixing in diesel engine environments. The model was also used to study the effects of engine speed, injection angle, spray cone angle, droplet distribution, and intake swirl angle on the flow field, spray penetration and vaporization, and turbulence in motored two-stroke diesel engines. It is shown that there are optimum conditions for injection, which depend on droplet distribution, swirl, spray cone angle, and injection angle. The optimum conditions result in good spray penetration and vaporization and in good fuel mixing. The calculation presented clearly indicates that internal combustion engine models can be used to assess, at least qualitatively, the effects of injection characteristics and engine operating conditions on the flow field and on the spray penetration and vaporization in diesel engines.

Antibacterial Effects of a Cell-Penetrating Peptide Isolated from Kefir.

PubMed

Miao, Jianyin; Guo, Haoxian; Chen, Feilong; Zhao, Lichao; He, Liping; Ou, Yangwen; Huang, Manman; Zhang, Yi; Guo, Baoyan; Cao, Yong; Huang, Qingrong

2016-04-27

Kefir is a traditional fermented milk beverage used throughout the world for centuries. A cell-penetrating peptide, F3, was isolated from kefir by Sephadex G-50 gel filtration, DEAE-52 ion exchange, and reverse-phase high-performance liquid chromatography. F3 was determined to be a low molecular weight peptide containing one leucine and one tyrosine with two phosphate radicals. This peptide displayed antimicrobial activity across a broad spectrum of organisms including several Gram-positive and Gram-negative bacteria as well as fungi, with minimal inhibitory concentration (MIC) values ranging from 125 to 500 μg/mL. Cellular penetration and accumulation of F3 were determined by confocal laser scanning microscopy. The peptide was able to penetrate the cellular membrane of Escherichia coli and Staphylococcus aureus. Changes in cell morphology were observed by scanning electron microscopy (SEM). The results indicate that peptide F3 may be a good candidate for use as an effective biological preservative in agriculture and the food industry.

A quantitative method for estimating dermal benzene absorption from benzene-containing hydrocarbon liquids.

PubMed

Petty, Stephen E; Nicas, Mark; Boiarski, Anthony A

2011-01-01

This study examines a method for estimating the dermal absorption of benzene contained in hydrocarbon liquids that contact the skin. This method applies to crude oil, gasoline, organic solvents, penetrants, and oils. The flux of benzene through occluded skin as a function of the percent vol/vol benzene in the liquid is derived by fitting a curve to experimental data; the function is supralinear at benzene concentrations < or = 5% vol/vol. When a liquid other than pure benzene is on nonoccluded skin, benzene may preferentially evaporate from the liquid, which thereby decreases the benzene flux. We present a time-averaging method here for estimating the reduced dermal flux during evaporation. Example calculations are presented for benzene at 2% vol/vol in gasoline, and for benzene at 0.1% vol/vol in a less volatile liquid. We also discuss other factors affecting dermal absorption.

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

Peterson, Per F.

A high-temperature containment-isolation system for transferring heat from a nuclear reactor containment to a high-pressure heat exchanger is presented. The system uses a high-temperature, low-volatility liquid coolant such as a molten salt or a liquid metal, where the coolant flow path provides liquid free surfaces a short distance from the containment penetrations for the reactor hot-leg and the cold-leg, where these liquid free surfaces have a cover gas maintained at a nearly constant pressure and thus prevent high-pressures from being transmitted into the reactor containment, and where the reactor vessel is suspended within a reactor cavity with a plurality ofmore » refractory insulator blocks disposed between an actively cooled inner cavity liner and the reactor vessel.« less

Evaluation of nicotinamide microemulsion on the skin penetration enhancement.

PubMed

Boonme, Prapaporn; Boonthongchuay, Chalida; Wongpoowarak, Wibul; Amnuaikit, Thanaporn

2016-01-01

This study purposed to evaluate a microemulsion containing nicotinamide for its characteristics, stability, and skin penetration and retention comparing with a solution of nicotinamide in 2:1 mixture of water and isopropyl alcohol (IPA). The microemulsion system was composed of 1:1 mixture of Span80 and Tween80 as a surfactant mixture, isopropyl palmitate (IPP) as an oil phase, and 2:1 mixture of water and IPA as an aqueous phase. Nicotinamide microemulsion was prepared by dissolving the active in the aqueous phase before simply mixing with the other components. It was determined for its characteristics and stability under various conditions. The skin penetration and retention studies of nicotinamide microemulsion and solution were performed by modified Franz diffusion cells, using newborn pig skin as the membrane. The results showed that nicotinamide microemulsion could be obtained as clear yellowish liquid, was water-in-oil (w/o) type, possessed Newtonian flow, and exhibited physicochemical stability when kept at 4 °C and room temperature (≈30 ± 2 °C) during 3 months. From the skin penetration data, the microemulsion could enhance the skin penetration of nicotinamide comparing with the solution. Additionally, nicotinamide microemulsion could provide much higher amount of skin retention than that of skin penetration, resulting in suitability for a cosmeceutical product.

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

49 CFR 178.58 - Specification 4DA welded steel cylinders for aircraft use.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., if water quenched or quenched with a liquid producing a cooling rate in excess of 80 percent of the cooling rate of water, must be inspected by the magnetic particle or dye penetrant method to detect the...

49 CFR 178.58 - Specification 4DA welded steel cylinders for aircraft use.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., if water quenched or quenched with a liquid producing a cooling rate in excess of 80 percent of the cooling rate of water, must be inspected by the magnetic particle or dye penetrant method to detect the...

49 CFR 178.58 - Specification 4DA welded steel cylinders for aircraft use.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., if water quenched or quenched with a liquid producing a cooling rate in excess of 80 percent of the cooling rate of water, must be inspected by the magnetic particle or dye penetrant method to detect the...

A miniaturized test method for the mechanical characterization of structural materials for fusion reactors

NASA Astrophysics Data System (ADS)

Gondi, P.; Donato, A.; Montanari, R.; Sili, A.

1996-10-01

This work deals with a non-destructive method for mechanical tests which is based on the indentation of materials at a constant rate by means of a cylinder with a small radius and penetrating flat surface. The load versus penetration depth curves obtained using this method have shown correspondences with those of tensile tests and have given indications about the mechanical properties on a reduced scale. In this work penetration tests have been carried out on various kinds of Cr martensitic steels (MANET-2, BATMAN and modified F82H) which are of interest for first wall and structural applications in future fusion reactors. The load versus penetration depth curves have been examined with reference to data obtained in tensile tests and to microhardness measurements. Penetration tests have been performed at various temperature (from -180 to 100°C). Conclusions, which can be drawn for the ductile to brittle transition, are discussed for MANET-2 steel. Preliminary results obtained on BATMAN and modified F82H steels are reported. The characteristics of the indenter imprints have been studied by scanning electron microscopy.

Transdermal Photopolymerization for Minimally Invasive Implantation

NASA Astrophysics Data System (ADS)

Elisseeff, J.; Anseth, K.; Sims, D.; McIntosh, W.; Randolph, M.; Langer, R.

1999-03-01

Photopolymerizations are widely used in medicine to create polymer networks for use in applications such as bone restorations and coatings for artificial implants. These photopolymerizations occur by directly exposing materials to light in "open" environments such as the oral cavity or during invasive procedures such as surgery. We hypothesized that light, which penetrates tissue including skin, could cause a photopolymerization indirectly. Liquid materials then could be injected s.c. and solidified by exposing the exterior surface of the skin to light. To test this hypothesis, the penetration of UVA and visible light through skin was studied. Modeling predicted the feasibility of transdermal polymerization with only 2 min of light exposure required to photopolymerize an implant underneath human skin. To establish the validity of these modeling studies, transdermal photopolymerization first was applied to tissue engineering by using "injectable" cartilage as a model system. Polymer/chondrocyte constructs were injected s.c. and transdermally photopolymerized. Implants harvested at 2, 4, and 7 weeks demonstrated collagen and proteoglycan production and histology with tissue structure comparable to native neocartilage. To further examine this phenomenon and test the applicability of transdermal photopolymerization for drug release devices, albumin, a model protein, was released for 1 week from photopolymerized hydrogels. With further study, transdermal photpolymerization potentially could be used to create a variety of new, minimally invasive surgical procedures in applications ranging from plastic and orthopedic surgery to tissue engineering and drug delivery.

A Capillary-Based Static Phase Separator for Highly Variable Wetting Conditions

NASA Technical Reports Server (NTRS)

Thomas, Evan A.; Graf, John C.; Weislogel, Mark M.

2010-01-01

The invention, a static phase separator (SPS), uses airflow and capillary wetting characteristics to passively separate a two-phase (liquid and air) flow. The device accommodates highly variable liquid wetting characteristics. The resultant design allows for a range of wetting properties from about 0 to over 90 advancing contact angle, with frequent complete separation of liquid from gas observed when using appropriately scaled test conditions. Additionally, the design accommodates a range of air-to-liquid flow-rate ratios from only liquid flow to over 200:1 air-to-liquid flow rate. The SPS uses a helix input section with an ice-cream-cone-shaped constant area cross section (see figure). The wedge portion of the cross section is on the outer edge of the helix, and collects the liquid via centripetal acceleration. The helix then passes into an increasing cross-sectional area vane region. The liquid in the helix wedge is directed into the top of capillary wedges in the liquid containment section. The transition from diffuser to containment section includes a 90 change in capillary pumping direction, while maintaining inertial direction. This serves to impinge the liquid into the two off-center symmetrical vanes by the airflow. Rather than the airflow serving to shear liquid away from the capillary vanes, the design allows for further penetration of the liquid into the vanes by the air shear. This is also assisted by locating the air exit ports downstream of the liquid drain port. Additionally, any droplets not contained in the capillary vanes are re-entrained downstream by a third opposing capillary vane, which directs liquid back toward the liquid drain port. Finally, the dual air exit ports serve to slow the airflow down, and to reduce the likelihood of shear. The ports are stove-piped into the cavity to form an unfriendly capillary surface for a wetting fluid to carryover. The liquid drain port is located at the start of the containment region, allowing for draining the bulk fluid in a continuous circuit. The functional operation of the SPS involves introducing liquid flow (from a human body, a syringe, or other source) to the two-phase inlet while an air fan pulls on the air exit lines. The fan is operated until the liquid is fully introduced. The system is drained by negative pressure on the liquid drain lines when the SPS containment system is full.

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

Formulation and evaluation of lidocaine base ethosomes for transdermal delivery.

PubMed

Zhu, Xiaoliang; Li, Fuli; Peng, Xuebiao; Zeng, Kang

2013-08-01

Although transdermal preparations of local anesthetics have been used to reduce pain caused by skin surgery, these preparations cannot effectively penetrate through the epidermis because of the barrier formed by the stratum corneum and the thick epidermis. Ethosomes can effectively transport drugs across the skin because of their thermodynamic stability, small size, high encapsulation efficiency, and percutaneous penetration. We evaluated lidocaine base ethosomes by measuring their loading efficiency, encapsulation efficiency, thermodynamic stability, and percutaneous penetration capability in vitro, and their effectiveness and cutaneous irritation in vivo. Lidocaine base ethosomes were prepared using the injection-sonication-filter method. Size, loading efficiency, encapsulation efficiency, and stability were evaluated using a Zetasizer and high performance liquid chromatography. Formulation was determined by measuring the maximum encapsulation efficiency in the orthogonal test. Percutaneous penetration efficiency in vitro was analyzed using a Franz-type diffusion cell experiment. In vivo effectiveness was analyzed using the pinprick test. Cutaneous irritancy tests were performed on white guinea pigs, followed by histopathologic analysis. The results were compared with lidocaine liposomes as well as lidocaine delivered in a hydroethanolic solution. Lidocaine base ethosomes composed of 5% (w/w) egg phosphatidyl choline, 35% (w/w) ethanol, 0.2% (w/w) cholesterol, 5% (w/w) lidocaine base, and ultrapure water had a mean maximum encapsulation of 51% ± 4%, a mean particle size of 31 ± 3 nm, and a mean loading efficiency of 95.0% ± 0.1%. The encapsulation efficiency of lidocaine base ethosomes remained stable for 60 days at 25°C ± 1°C (95% confidence interval [CI], -1.12% to 1.34%; P = 0.833). The transdermal flux of lidocaine base differed significantly for the 3 preparations (F = 120, P < 0.001), being significantly greater from ethosomes than from liposomes (95% corrected CI, 1129-1818 µg/(cm(2)·h); P < 0.001), and from hydroethanolic solution (95% corrected CI, 1468-2157 µg/(cm(2)·h); P < 0.001). Lidocaine base ethosomes had a shorter onset time and longer duration in vivo than did lidocaine base liposomes or lidocaine delivered in a hydroethanolic solution. Lidocaine base ethosomes showed no evidence of dermal irritation in guinea pigs. Ethosomes are potential carriers of local anesthetics across the skin and may have applicability for other percutaneous drugs that require rapid onset.

Rapid Cycle Casting of Steel

DTIC Science & Technology

1981-07-01

C’, and at temperature T, are Infiltrated by !L amougt of liquid of composition C’., such that ,C, 4 f+.C’L - X. V. 7 average carbon content of the...maximum liquid penetration was 100 mm at an infiltration pressure of 755 kPa. The average casting composition was 0.94 w/o carbon . The segregation at...content* at four casting locations. 2. Results The casting composition ( carbon content) as a function of casting location is given in Table D-IV. The

Superamphiphobic Silicon-Nanowire-Embedded Microsystem and In-Contact Flow Performance of Gas and Liquid Streams.

PubMed

Ko, Dong-Hyeon; Ren, Wurong; Kim, Jin-Oh; Wang, Jun; Wang, Hao; Sharma, Siddharth; Faustini, Marco; Kim, Dong-Pyo

2016-01-26

Gas and liquid streams are invariably separated either by a solid wall or by a membrane for heat or mass transfer between the gas and liquid streams. Without the separating wall, the gas phase is present as bubbles in liquid or, in a microsystem, as gas plugs between slugs of liquid. Continuous and direct contact between the two moving streams of gas and liquid is quite an efficient way of achieving heat or mass transfer between the two phases. Here, we report a silicon nanowire built-in microsystem in which a liquid stream flows in contact with an underlying gas stream. The upper liquid stream does not penetrate into the lower gas stream due to the superamphiphobic nature of the silicon nanowires built into the bottom wall, thereby preserving the integrity of continuous gas and liquid streams, although they are flowing in contact. Due to the superamphiphobic nature of silicon nanowires, the microsystem provides the best possible interfacial mass transfer known to date between flowing gas and liquid phases, which can achieve excellent chemical performance in two-phase organic syntheses.

The regimes of twin-fluid jet-in-crossflow at atmospheric and jet-engine operating conditions

NASA Astrophysics Data System (ADS)

Tan, Zu Puayen; Bibik, Oleksandr; Shcherbik, Dmitriy; Zinn, Ben T.; Patel, Nayan

2018-02-01

The "Twin-Fluid Jet-in-Crossflow (TF-JICF)" is a nascent variation of the classical JICF, in which a liquid jet is co-injected with an annular sleeve of gas into a gaseous crossflow. Jet-engine designers are interested in using TF-JICF for liquid-fuel injection and atomization in the next-generation combustors because it is expected to minimize combustor-damaging auto-ignition and fuel-coking tendencies. However, experimental data of TF-JICF are sparse. Furthermore, a widely accepted TF-JICF model that correlates the spray's penetration to the combined liquid-gas momentum-flux ratio (Jeff) is increasingly showing discrepancy with emerging results, suggesting a gap in the current understanding of TF-JICF. This paper describes an investigation that addressed the gap by experimentally characterizing the TF-JICF produced by a single injector across wide ranges of operating conditions (i.e., jet-A injectant, crossflow of air, crossflow Weber number = 175-1050, crossflow pressure Pcf = 1.8-9.5 atm, momentum-flux ratio J = 5-40, and air-nozzle dP = 0%-150% of Pcf). These covered the conditions previously used to develop the Jeff model, recently reported conditions that produced Jeff discrepancies, and high-pressure conditions found in jet-engines. Dye-based shadowgraph was used to acquire high-resolution (13.52 μm/pixel) images of the TF-JICF, which revealed wide-ranging characteristics such as the disrupted Rayleigh-Taylor jet instabilities, air-induced jet corrugations, spray-bifurcations, and prompt-atomization. Analyses of the data showed that contrary to the literature, the TF-JICF's penetration is not monotonically related to Jeff. A new conceptual framework for TF-JICF is proposed, where the flow configuration is composed of four regimes, each having different penetration trends, spray structures, and underlying mechanisms.

Analysis of thermal performance of penetrated multi-layer insulation

NASA Technical Reports Server (NTRS)

Foster, Winfred A., Jr.; Jenkins, Rhonald M.; Yoo, Chai H.; Barrett, William E.

1988-01-01

Results of research performed for the purpose of studying the sensitivity of multi-layer insulation blanket performance caused by penetrations through the blanket are presented. The work described in this paper presents the experimental data obtained from thermal vacuum tests of various penetration geometries similar to those present on the Hubble Space Telescope. The data obtained from these tests is presented in terms of electrical power required sensitivity factors referenced to a multi-layer blanket without a penetration. The results of these experiments indicate that a significant increase in electrical power is required to overcome the radiation heat losses in the vicinity of the penetrations.

40 CFR 1065.376 - Chiller NO2 penetration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... residual water vapor that passed through the chiller at the chiller's outlet temperature and pressure. (3... after major maintenance. (b) Measurement principles. A chiller removes water, which can otherwise interfere with a NOX measurement. However, liquid water remaining in an improperly designed chiller can...

40 CFR 1065.376 - Chiller NO2 penetration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... residual water vapor that passed through the chiller at the chiller's outlet temperature and pressure. (3... after major maintenance. (b) Measurement principles. A chiller removes water, which can otherwise interfere with a NOX measurement. However, liquid water remaining in an improperly designed chiller can...

40 CFR 1065.376 - Chiller NO2 penetration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... residual water vapor that passed through the chiller at the chiller's outlet temperature and pressure. (3... after major maintenance. (b) Measurement principles. A chiller removes water, which can otherwise interfere with a NOX measurement. However, liquid water remaining in an improperly designed chiller can...

Forces required for a knife to penetrate a variety of clothing types.

PubMed

Nolan, Gary; Hainsworth, Sarah V; Rutty, Guy N

2013-03-01

In stabbing incidents, it is usual for the victim to be clothed and therefore a knife penetrates both clothes and skin. Clothes (other than leather) have been thought to make little difference to the penetration force. However, there is little quantitative data in the literature. In this study, a range of clothes have been tested, either singly or in layers of, for example, T-shirt and shirt, to quantify the additional force required when clothes are present. A materials testing system has been used to test the penetration force required to stab through clothes into a foam-silicone rubber skin simulant. The results show that the force required can be significantly different, particularly when layers of clothing are penetrated. A cotton t-shirt adds c. 8 N to the penetration force, while a T-shirt and jacket can add an additional 21 N. The results allow a more quantitative assessment of forces required in stabbing. © 2012 American Academy of Forensic Sciences.

Development of a HPLC method for determination of four UV filters in sunscreen and its application to skin penetration studies.

PubMed

Souza, Carla; Maia Campos, Patrícia M B G

2017-12-01

This study describes the development, validation and application of a high-performance liquid chromatography (HPLC) method for the simultaneous determination of the in vitro skin penetration profile of four UV filters on porcine skin. Experiments were carried out on a gel-cream formulation containing the following UV filters: diethylamino hydroxybenzoyl hexyl benzoate (DHHB), bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT), methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) and ethylhexyl triazone (EHT). The HPLC method demonstrated suitable selectivity, linearity (10.0-50.0 μg/mL), precision, accuracy and recovery from porcine skin and sunscreen formulation. The in vitro skin penetration profile was evaluated using Franz vertical diffusion cells for 24 h after application on porcine ear skin. None of the UV filters penetrated the porcine skin. Most of them stayed on the skin surface (>90%) and only BEMT, EHT and DHHB reached the dermis plus epidermis layer. These results are in agreement with previous results in the literature. Therefore, the analytical method was useful to evaluate the in vitro skin penetration of the UV filters and may help the development of safer and effective sunscreen products. Copyright © 2017 John Wiley & Sons, Ltd.

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.

Adsorption of polypropylene from dilute solutions on a zeolite column packing.

PubMed

Macko, Tibor; Pasch, Harald; Denayer, Joeri F

2005-01-01

Faujasite type zeolite CBV-780 was tested as adsorbent for isotactic polypropylene by liquid chromatography. When cyclohexane, cyclohexanol, n-decanol, n-dodecanol, diphenylmethane, or methylcyclohexane was used as mobile phase, polypropylene was fully or partially retained within the column packing. This is the first series of sorbent-solvent systems to show a pronounced retention of isotactic polypropylene. According to the hydrodynamic volumes of polypropylene in solution, macromolecules of polypropylene should be fully excluded from the pore volume of the sorbent. Sizes of polypropylene macromolecules in linear conformations, however, correlate with the pore size of the column packing used. It is presumed that the polypropylene chains partially penetrate into the pores and are retained due to the high adsorption potential in the narrow pores.

Status of Superheated Spray and Post Combustor Particulate Modeling for NCC

NASA Technical Reports Server (NTRS)

Liu, Nan-Suey; Raju, Suri; Wey, Thomas

2007-01-01

At supersonic cruise conditions, high fuel temperatures, coupled with low pressures in the combustor, create potential for superheated fuel injection leading to shorter fuel jet break-up time and reduced spray penetration. Another issue particularly important to the supersonic cruise is the aircraft emissions contributing to the climate change in the atmosphere. Needless to say, aircraft emissions in general also contribute to the air pollution in the neighborhood of airports. The objectives of the present efforts are to establish baseline for prediction methods and experimental data for (a) liquid fuel atomization and vaporization at superheated conditions and (b) particle sampling systems and laboratory or engine testing environments, as well as to document current capabilities and identify gaps for future research.

Diffusion of biostimulators into plant tissues

NASA Astrophysics Data System (ADS)

Kolomazník, Karel; Pecha, Jiří; Friebrová, Veronika; Janáčová, Dagmar; Vašek, Vladimír

2012-09-01

Biostimulators are substances able to enhance the immune system of cultivated crops and support plant metabolism. Their utilization helps to reduce the amount of chemicals used in agriculture. To perform the desired effect, a biostimulator must be able to penetrate into the plant tissue. The time of penetration however, is limited, since the biostimulator must remain in a liquid state. This is of great importance—especially in field conditions, where the treated plants are exposed to different weather condition and other extrinsic factors. A mathematical model based on diffusion mechanisms has been elaborated to describe the biostimulator transport process from penetration of the leaves into the plant's inner tissues. By means of the effective diffusion coefficient of the prepared specific protein hydrolyzate, this model can be used to estimate the time necessary for the uptake of the minimal active amount of the biostimulator.

Technology diffusion and diagnostic testing for prostate cancer

PubMed Central

Schroeck, Florian R.; Kaufman, Samuel R.; Jacobs, Bruce L.; Skolarus, Ted A.; Miller, David C.; Weizer, Alon Z.; Montgomery, Jeffrey S.; Wei, John T.; Shahinian, Vahakn B.; Hollenbeck, Brent K.

2013-01-01

Purpose While the dissemination of robotic prostatectomy and intensity-modulated radiotherapy (IMRT) may fuel increased use of prostatectomy and radiotherapy, these new technologies may also have spillover effects related to diagnostic testing for prostate cancer. Therefore, we examined the association of regional technology penetration with receipt of prostate specific antigen (PSA) testing and prostate biopsy. Methods In this retrospective cohort study, we included 117,857 men age 66 and older from the 5% sample of Medicare beneficiaries living in the Surveillance Epidemiology and End Results (SEER) areas from 2003 – 2007. Regional technology penetration was measured as the number of providers performing robotic prostatectomy or IMRT per population in a healthcare market (i.e., hospital referral region). We assessed the association of technology penetration with rates of PSA testing and prostate biopsy with generalized estimating equations. Results High technology penetration was associated with increased rates of PSA testing (442 versus 425 per 1,000 person-years, p<0.01) and similar rates of prostate biopsy (10.1 versus 9.9 per 1,000 person-years, p=0.69). The impact of technology penetration on PSA testing and prostate biopsy was much smaller than the effect of age, race, and comorbidity (e.g., PSA testing rate per 1,000 person-years: 485 versus 373 for men with only one versus 3+ co-morbid conditions, p<0.01). Conclusions Increased technology penetration was associated with slightly higher rates of PSA testing and no change in prostate biopsy rates. Collectively, our findings temper concerns that adoption of new technology accelerates diagnostic testing for prostate cancer. PMID:23669564

Impact of direct and indirect application of rising furfural concentrations on viability, infectivity and reproduction of the root-knot nematode, Meloidogyne incognita in Pisum sativum.

PubMed

Abdelnabby, Hazem; Wang, Yunhe; Xiao, Xueqiong; Wang, Gaofeng; Yang, Fan; Xiao, Yannong

2016-07-01

The gradual withdraw of several broadly used nematicides from market has enhanced the need to develop sustainable and eco-friendly alternatives with nematicidal properties. Furfural is one of the promising alternatives to fill this need. Baseline information about the impact of furfural on egg hatch, penetration potential and ultrastructure of nematode is lacking. In this study, the reagent-grade (purity ≥ 99.0%) of furfural was applied against Meloidogyne incognita. In vitro tests showed gradual reduction in either the rate of egg hatch or second stage juvenile (J2) viability of M. incognita when immersed in concentrations ranging from 0 to 10.0 μl/ml furfural. The mean EC50 for J2 and egg hatch was 0.37 and 0.27 μl/ml furfural, respectively. Furfural, even at low concentrations, resulted in a considerable suppression in egg hatch. Hatch was <5% after 8 days at 0.63 μl/ml furfural. The same furfural concentrations after 12 h caused 57.25% loss of viability in J2. Moreover, the penetration rate of juveniles to pea roots was suppressed when furfural was even applied at low rates. In pot experiments, furfural was applied as liquid (direct) or vapor (indirect) treatments at rates of 0-1.5 ml/kg soil. Significant reduction in galling, egg production and population density of M. incognita observed when furfural was applied at rates >0.2 ml/kg soil. No adverse effect was detected on plants or free-living nematodes as a result of furfural application. Liquid furfural proved to have superior juvenile-suppressive effect whereas its vapor has such superiority against eggs. Scanning electron microscope (SEM) study showed irregular appearance of the body surface accompanied with some cuticle disfigurement of furfural-treated juveniles. These results indicated that furfural can adversely affect egg hatch, juvenile viability, penetration potential and ultrastructure of M. incognita. Furfural may therefore be of a considerable potential as an appropriate alternative for class I nematicides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries

PubMed Central

Hofmann, Andreas; Kaufmann, Christoph; Müller, Marcus; Hanemann, Thomas

2015-01-01

In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE) and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations. PMID:26343636

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

PubMed

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

2015-12-15

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

Penetrance estimates for BRCA1, BRCA2 (also applied to Lynch syndrome) based on presymptomatic testing: a new unbiased method to assess risk?

PubMed

Evans, D Gareth; Woodward, Emma; Harkness, Elaine F; Howell, Anthony; Plaskocinska, Inga; Maher, Eamonn R; Tischkowitz, Marc D; Lalloo, Fiona

2018-02-26

The identification of BRCA1 , BRCA2 or mismatch repair (MMR) pathogenic gene variants in familial breast/ovarian/colorectal cancer families facilitates predictive genetic testing of at-risk relatives. However, controversy still exists regarding overall lifetime risks of cancer in individuals testing positive. We assessed the penetrance of BRCA1 , BRCA2, MLH1 and MSH2 mutations in men and women using Bayesian calculations based on ratios of positive to negative presymptomatic testing by 10-year age cohorts. Mutation position was also assessed for BRCA1 / BRCA2. RESULTS: Using results from 2264 presymptomatic tests in first-degree relatives (FDRs) of mutation carriers in BRCA1 and BRCA2 and 646 FDRs of patients with MMR mutations, we assessed overall associated cancer penetrance to age of 68 years as 73% (95% CI 61% to 82%) for BRCA1 , 60% (95% CI 49% to 71%) for BRCA2 , 95% (95% CI 76% to 99%) for MLH1% and 61% (95% CI 49% to 76%) for MSH2 . There was no evidence for significant penetrance for males in BRCA1 or BRCA2 families and males had equivalent penetrance to females with Lynch syndrome. Mutation position and degree of family history influenced penetrance in BRCA2 but not BRCA1. CONCLUSION: We describe a new method for assessing penetrance in cancer-prone syndromes. Results are in keeping with published prospective series and present modern-day estimates for overall disease penetrance that bypasses retrospective series biases. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Testing of a Spray-Bar Zero Gravity Cryogenic Vent System for Upper Stages

NASA Technical Reports Server (NTRS)

Lak, Tibor; Flachbart, Robin; Nguyen, Han; Martin, James

1999-01-01

The capability to vent in zero gravity without resettling is a fundamental technology need that involves practically all uses of subcritical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule- Thomson (J-T) valve to extract then-nal energy from the propellant. In a cooperative effort, Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (N4HTB) was used to test a unique "spray bar" TVS system developed by Boeing. A schematic of this system is included in Figure 1. The system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it radially into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the spray bar heat exchanger element, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. Figure 2 is a plot of ullage pressure (P4) and liquid vapor pressure (PSAI) versus time. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses. The primary advantage of the spray bar configuration is that pressure reduction is achieved independent of liquid and vapor location, thereby enhancing the applicability of normal gravity test data to zero gravity conditions. The in-tank components are minimized with the proposed TVS design. Because the recirculation pump is external to the tank, no electrical power penetration of the tank is required for pump or valve operation. This is especially desirable for L02 tanks since the presence of an electrical ignition source in oxygen represents a critical failure mode. Also, since the critical components (pump, motor, valve, orifice) are external to the tank, system checkout and ground servicing/replacement are easier. For zero-g operation, component replacement external to the tank may be a significant benefit. In addition to satisfying the zero g TVS design objectives, the TVS concept tested offers additional benefits to the integrated subcritical cryogenic storage and launch system.

Effect of water content on the glass transition temperature of mixtures of sugars, polymers, and penetrating cryoprotectants in physiological buffer.

PubMed

Drake, Andrew C; Lee, Youngjoo; Burgess, Emma M; Karlsson, Jens O M; Eroglu, Ali; Higgins, Adam Z

2018-01-01

Long-term storage of viable mammalian cells is important for applications ranging from in vitro fertilization to cell therapy. Cryopreservation is currently the most common approach, but storage in liquid nitrogen is relatively costly and the requirement for low temperatures during shipping is inconvenient. Desiccation is an alternative strategy with the potential to enable viable cell preservation at more convenient storage temperatures without the need for liquid nitrogen. To achieve stability during storage in the dried state it is necessary to remove enough water that the remaining matrix forms a non-crystalline glassy solid. Thus, the glass transition temperature is a key parameter for design of cell desiccation procedures. In this study, we have investigated the effects of moisture content on the glass transition temperature (Tg) of mixtures of sugars (trehalose or raffinose), polymers (polyvinylpyrrolidone or Ficoll), penetrating cryoprotectants (ethylene glycol, propylene glycol, or dimethyl sulfoxide), and phosphate buffered saline (PBS) solutes. Aqueous solutions were dried to different moisture contents by equilibration with saturated salt solutions, or by baking at 95°C. The glass transition temperatures of the dehydrated samples were then measured by differential scanning calorimetry. As expected, Tg increased with decreasing moisture content. For example, in a desiccation medium containing 0.1 M trehalose in PBS, Tg ranged from about 360 K for a completely dry sample to about 220 K at a water mass fraction of 0.4. Addition of polymers to the solutions increased Tg, while addition of penetrating cryoprotectants decreased Tg. Our results provide insight into the relationship between relative humidity, moisture content and glass transition temperature for cell desiccation solutions containing sugars, polymers and penetrating cryoprotectants.

Effect of water content on the glass transition temperature of mixtures of sugars, polymers, and penetrating cryoprotectants in physiological buffer

PubMed Central

Burgess, Emma M.; Karlsson, Jens O. M.; Eroglu, Ali

2018-01-01

Long-term storage of viable mammalian cells is important for applications ranging from in vitro fertilization to cell therapy. Cryopreservation is currently the most common approach, but storage in liquid nitrogen is relatively costly and the requirement for low temperatures during shipping is inconvenient. Desiccation is an alternative strategy with the potential to enable viable cell preservation at more convenient storage temperatures without the need for liquid nitrogen. To achieve stability during storage in the dried state it is necessary to remove enough water that the remaining matrix forms a non-crystalline glassy solid. Thus, the glass transition temperature is a key parameter for design of cell desiccation procedures. In this study, we have investigated the effects of moisture content on the glass transition temperature (Tg) of mixtures of sugars (trehalose or raffinose), polymers (polyvinylpyrrolidone or Ficoll), penetrating cryoprotectants (ethylene glycol, propylene glycol, or dimethyl sulfoxide), and phosphate buffered saline (PBS) solutes. Aqueous solutions were dried to different moisture contents by equilibration with saturated salt solutions, or by baking at 95°C. The glass transition temperatures of the dehydrated samples were then measured by differential scanning calorimetry. As expected, Tg increased with decreasing moisture content. For example, in a desiccation medium containing 0.1 M trehalose in PBS, Tg ranged from about 360 K for a completely dry sample to about 220 K at a water mass fraction of 0.4. Addition of polymers to the solutions increased Tg, while addition of penetrating cryoprotectants decreased Tg. Our results provide insight into the relationship between relative humidity, moisture content and glass transition temperature for cell desiccation solutions containing sugars, polymers and penetrating cryoprotectants. PMID:29304068

Comparison of Trained Clinician Ratings with Expert Ratings of Aspiration on Videofluoroscopic Images from a Randomized Clinical Trial

PubMed Central

Hind, Jacqueline A.; Gensler, Gary; Brandt, Diane K.; Miller Gardner, Patricia J.; Blumenthal, Loreen; Gramigna, Gary D.; Kosek, Steven; Lundy, Donna; McGarvey-Toler, Susan; Rockafellow, Susan; Sullivan, Paula A.; Villa, Marybell; Gill, Gary D.; Lindblad, Anne S.; Logemann, Jeri A.; Robbins, JoAnne

2009-01-01

Accurate detection and classification of aspiration is a critical component of videofluoroscopic swallowing evaluation, the most commonly utilized instrumental method for dysphagia diagnosis and treatment. Currently published literature indicates that inter-judge reliability for the identification of aspiration ranges from poor to fairly good depending on the amount of training provided to clinicians. The majority of extant studies compared judgments among clinicians. No studies included judgments made during the use of a postural compensatory strategy. The purpose of this study was to examine the accuracy of judgments made by speech-language pathologists (SLPs) practicing in hospitals compared with unblinded expert judges when identifying aspiration and using the 8-point Penetration/Aspiration Scale. Clinicians received extensive training for the detection of aspiration and minimal training on use of the Penetration/Aspiration Scale. Videofluoroscopic data were collected from 669 patients as part of a large, randomized clinical trial and include judgments of 10,200 swallows made by 76 clinicians from 44 hospitals in 11 states. Judgments were made on swallows during use of dysphagia compensatory strategies: chin down posture with thin-liquids and thickened liquids (nectar-thick and honey-thick consistencies) in a head neutral posture. The subject population included patients with Parkinson’s disease and/or dementia. Kappa statistics indicate high accuracy for all interventions by SLPs for identification of aspiration (all К > .86) and variable accuracy (range 69%–76%) using the Penetration/Aspiration Scale when compared to expert judges. It is concluded that while the accuracy of identifying the presence of aspiration by SLPs is excellent, more extensive training and/or image enhancement is recommended for precise use of the Penetration/Aspiration Scale. PMID:18953607

Arias intensity assessment of liquefaction test sites on the east side of San Francisco Bay affected by the Loma Prieta, California, earthquake of 17 October 1989

USGS Publications Warehouse

Kayen, R.E.

1997-01-01

Abstract. Uncompacted artificial-fill deposits on the east side of San Francisco Bay suffered severe levels of soil liquefaction during the Loma Prieta earthquake of 17 October 1989. Damaged areas included maritime-port facilities, office buildings, and shoreline transportation arteries, ranging from 65 to 85 km from the north end of the Loma Prieta rupture zone. Typical of all these sites, which represent occurrences of liquefaction-induced damage farthest from the rupture zone, are low cone penetration test and Standard Penetration Test resistances in zones of cohesionless silty and sandy hydraulic fill, and underlying soft cohesive Holocene and Pleistocene sediment that strongly amplified ground motions. Postearthquake investigations at five study sites using standard penetration tests and cone penetration tests provide a basis for evaluation of the Arias intensity-based methodology for assessment of liquefaction susceptibility. ?? 1997 Kluwer Academic Publishers.

Lack of Penetration in Friction Stir Welds: Effects on Mechanical Properties and NDE Feasibility

NASA Technical Reports Server (NTRS)

Kinchen, David G.; Adams, Glynn P.

2000-01-01

This presentation reviews the issue of lack of penetration (LOP) in Friction Stir Welding and the feasibility of using non-destructive tests to detect . Friction Stir Welding takes place in the solid phase below the melting point of the materials to be joined. It thus gives the ability to join materials which are difficult to fusion weld, for example 2000 and 7000 aluminium alloys. This process though can result in a lack of penetration, due to an incomplete penetration of the DXZ. This is frequently referred to as a "kissing bond", which requires micro examination to detect. The presentation then discusses the surface crack tension tests. It then reviews the simulated service test and results. It then discusses the feasibility of using non-destructive examination to detect LOP, the forms of test which can be used, and the results the tests.

[The development and in vitro experiment study of a bio-type root canal filling sealer using calcium phosphate cement].

PubMed

Chen, Zuo-liang; Wei, Wei; Feng, Zhu-de; Liu, Xue-qing; Chen, Xiao-ling; Huang, Wen-xia

2007-10-01

The purpose of this study is to develop a novel root canal filling sealers based on calcium phosphate cement (CPC), and to evaluate its physical-chemical properties and in vitro antibacterial activity on the predominant bacteria infecting root canal. The fluidity and the setting time of the sealer were tested according to ISO 6876:2001(E) standards. The crystal size of the final product was determined. Its opacification with different composition were measured. The in vitro antibacterial property of the sealer was tested according to the Antimicrobial Susceptibility Testing of Anaerobes recommended by National Committee for Clinical Laboratory Standards (NCCLs). The involved bacteria included Actinomyces naeslundii(A. naeslundii), Peptostreptococcus anaerobius (P. anaerobius), Porphyromonas gingivalis (P. gingivalis), Porphyromonas endodpntalis (P. endodpntalis) and Fusobacterium nucleatum (F. nucleatum). Twenty single-rooted human extracted teeth were selected to evaluate the sealing ability using dye microleakage technology. Dye penetration was measured and the results were statistically analyzed using SPSS12.0 software package. The new root canal filling sealer was primarily composed of hydroxyapatite in 279 nm after setting. Its liquidity was suitable, the operating time was over 30 minutes, and the controlled setting time was (1.0+/-0.5) hours. The opacification was acceptable. MIC

Performance of multimirror quartzline lamps in a high-pressure, underwater environment

NASA Technical Reports Server (NTRS)

Slater, Howard A.

1988-01-01

Multimirror Quartzline Lamps are extremely versatile and effective for nonconventional imaging requirements such as high-speed photo and video instrumentation and high-magnification imaging. The lamps' versatility though, is not limited to conventional environments. Many research experiments and projects require a high pressure environment. Continuous photographic data acquisition in a high-pressure vessel requires wall penetrations and creates design problems as well as potential failure sites. Underwater photography adds the extra consideration of a liquid. This report expands upon the basic research presented in, Performance of Multimirror Quartzline Lamps in High-Pressure Environments, (NASA-TM-83793, Ernie Walker and Howard Slater, 1984). The report provides information to professional industrial, scientific, and technical photographers as well as research personnel on the survivability of lighting a multimirror quartzline lamp in a nonconventional high-pressure underwater environment. Test results of lighted ELH 300 W multimirror quartzline lamps under high-pressure conditions are documented and general information on the lamps' intensity (footcandle output), cone of light coverage, approximate color temperature is provided. Continuous lighting considerations in liquids are also discussed.

Pulsed arc plasma jet synchronized with drop-on-demand dispenser

NASA Astrophysics Data System (ADS)

Mavier, F.; Lemesre, L.; Rat, V.; Bienia, M.; Lejeune, M.; Coudert, J.-F.

2017-04-01

This work concerns with the liquid injection in arc plasma spraying for the development of finely structured ceramics coatings. Nanostructured coatings can be now achieved with nanopowders dispersed in a liquid (SPS: Suspension Plasma Spraying) or with a salt dissolved into a liquid (SPPS: Solution Precursor Plasma Spraying) injected into the plasma jet. Controlling electric arc instabilities confined in non-transferred arc plasma torch is therefore a key issue to get reproducible coating properties. Adjustment of parameters with a mono-cathode arc plasma allows a new resonance mode called “Mosquito”. A pulsed arc plasma producing a periodic regular voltage signal with modulation of enthalpy is obtained. The basic idea is to synchronize the injection system with the arc to introduce the liquid material in each plasma oscillation in the same conditions, in order to control the plasma treatment of the material in-fly. A custom-developed pulsed arc plasma torch is used with a drop-on-demand dispenser triggered by the arc voltage. A delay is added to adjust the droplets emission time and their penetration into the plasma gusts. Indeed, the treatment of droplets is also shown to be dependent on this injection delay. A TiO2 suspension and an aqueous solution of aluminium nitrate were optimized to get ejectable inks forming individual droplets. The feasibility of the process was demonstrated for SPS and SPPS techniques. Coatings from the suspension and the solution were achieved. First synchronized sprayings show a good penetration of the droplets into the plasma. Coatings show a fine structure of cauliflowers shapes. The synchronization of the ejection allows a control of morphology and a better deposition efficiency. Further investigations will find the optimal operating parameters to show the full potential of this original liquid injection technique.

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.

Contact Dermatitis from Penetration of Rubber Gloves by Acrylic Monomer

PubMed Central

Pegum, J. S.; Medhurst, F. A.

1971-01-01

An orthopaedic surgeon developed dermatitis from acrylic materials. The acrylic monomer was found to penetrate surgical rubber gloves readily. Cases of “rubber glove dermatitis” with negative patch tests may have a similar explanation. Laboratory tests suggest that monomer does not damage rubber sufficiently to allow bacteria to penetrate gloves, but it remains possible that this would happen under theatre conditions. PMID:5581492

Immobilized fluid membranes for gas separation

DOEpatents

Liu, Wei; Canfield, Nathan L; Zhang, Jian; Li, Xiaohong Shari; Zhang, Jiguang

2014-03-18

Provided herein are immobilized liquid membranes for gas separation, methods of preparing such membranes and uses thereof. In one example, the immobilized membrane includes a porous metallic host matrix and an immobilized liquid fluid (such as a silicone oil) that is immobilized within one or more pores included within the porous metallic host matrix. The immobilized liquid membrane is capable of selective permeation of one type of molecule (such as oxygen) over another type of molecule (such as water). In some examples, the selective membrane is incorporated into a device to supply oxygen from ambient air to the device for electrochemical reactions, and at the same time, to block water penetration and electrolyte loss from the device.

Technology diffusion and diagnostic testing for prostate cancer.

PubMed

Schroeck, Florian R; Kaufman, Samuel R; Jacobs, Bruce L; Skolarus, Ted A; Miller, David C; Weizer, Alon Z; Montgomery, Jeffrey S; Wei, John T; Shahinian, Vahakn B; Hollenbeck, Brent K

2013-11-01

While the dissemination of robotic prostatectomy and intensity modulated radiotherapy may fuel the increased use of prostatectomy and radiotherapy, these new technologies may also have spillover effects related to diagnostic testing for prostate cancer. Therefore, we examined the association of regional technology penetration with the receipt of prostate specific antigen testing and prostate biopsy. In this retrospective cohort study we included 117,857 men 66 years old or older from the 5% sample of Medicare beneficiaries living in Surveillance, Epidemiology and End Results (SEER) areas from 2003 to 2007. Regional technology penetration was measured as the number of providers performing robotic prostatectomy or intensity modulated radiotherapy per population in a health care market, ie hospital referral region. We assessed the association of technology penetration with the prostate specific antigen testing rate and prostate biopsy using generalized estimating equations. High technology penetration was associated with an increased rate of prostate specific antigen testing (442 vs 425/1,000 person-years, p<0.01) and a similar rate of prostate biopsy (10.1 vs 9.9/1,000 person-years, p=0.69). The impact of technology penetration on prostate specific antigen testing and prostate biopsy was much less than the effect of age, race and comorbidity, eg the prostate specific antigen testing rate per 1,000 person-years was 485 vs 373 for men with only 1 vs 3+ comorbid conditions (p<0.01). Increased technology penetration is associated with a slightly higher rate of prostate specific antigen testing and no change in the prostate biopsy rate. Collectively, our findings temper concerns that adopting new technology accelerates diagnostic testing for prostate cancer. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Solid versus Liquid Particle Sampling Efficiency of Three Personal Aerosol Samplers when Facing the Wind

PubMed Central

Koehler, Kirsten A.; Anthony, T. Renee; Van Dyke, Michael

2016-01-01

The objective of this study was to examine the facing-the-wind sampling efficiency of three personal aerosol samplers as a function of particle phase (solid versus liquid). Samplers examined were the IOM, Button, and a prototype personal high-flow inhalable sampler head (PHISH). The prototype PHISH was designed to interface with the 37-mm closed-face cassette and provide an inhalable sample at 10 l min−1 of flow. Increased flow rate increases the amount of mass collected during a typical work shift and helps to ensure that limits of detection are met, particularly for well-controlled but highly toxic species. Two PHISH prototypes were tested: one with a screened inlet and one with a single-pore open-face inlet. Personal aerosol samplers were tested on a bluff-body disc that was rotated along the facing-the-wind axis to reduce spatiotemporal variability associated with sampling supermicron aerosol in low-velocity wind tunnels. When compared to published data for facing-wind aspiration efficiency for a mouth-breathing mannequin, the IOM oversampled relative to mannequin facing-the-wind aspiration efficiency for all sizes and particle types (solid and liquid). The sampling efficiency of the Button sampler was closer to the mannequin facing-the-wind aspiration efficiency than the IOM for solid particles, but the screened inlet removed most liquid particles, resulting in a large underestimation compared to the mannequin facing-the-wind aspiration efficiency. The open-face PHISH results showed overestimation for solid particles and underestimation for liquid particles when compared to the mannequin facing-the-wind aspiration efficiency. Substantial (and statistically significant) differences in sampling efficiency were observed between liquid and solid particles, particularly for the Button and screened-PHISH, with a majority of aerosol mass depositing on the screened inlets of these samplers. Our results suggest that large droplets have low penetration efficiencies through screened inlets and that particle bounce, for solid particles, is an important determinant of aspiration and sampling efficiencies for samplers with screened inlets. PMID:21965462

7 CFR 3201.42 - Wood and concrete sealers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 15 2013-01-01 2013-01-01 false Wood and concrete sealers. 3201.42 Section 3201.42... Designated Items § 3201.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage...

7 CFR 3201.42 - Wood and concrete sealers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false Wood and concrete sealers. 3201.42 Section 3201.42... Designated Items § 3201.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage...

7 CFR 3201.42 - Wood and concrete sealers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 15 2012-01-01 2012-01-01 false Wood and concrete sealers. 3201.42 Section 3201.42... Designated Items § 3201.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage...

Purifying Nanomaterials

NASA Technical Reports Server (NTRS)

Hung, Ching-Cheh (Inventor); Hurst, Janet (Inventor)

2014-01-01

A method of purifying a nanomaterial and the resultant purified nanomaterial in which a salt, such as ferric chloride, at or near its liquid phase temperature, is used to penetrate and wet the internal surfaces of a nanomaterial to dissolve impurities that may be present, for example, from processes used in the manufacture of the nanomaterial.

The Effect and Mechanism of Transdermal Penetration Enhancement of Fu's Cupping Therapy: New Physical Penetration Technology for Transdermal Administration with Traditional Chinese Medicine (TCM) Characteristics.

PubMed

Xie, Wei-Jie; Zhang, Yong-Ping; Xu, Jian; Sun, Xiao-Bo; Yang, Fang-Fang

2017-03-27

In this paper, a new type of physical penetration technology for transdermal administration with traditional Chinese medicine (TCM) characteristics is presented. Fu's cupping therapy (FCT), was established and studied using in vitro and in vivo experiments and the penetration effect and mechanism of FCT physical penetration technology was preliminarily discussed. With 1-(4-chlorobenzoyl)-5-methoxy-2-methylindole-3-ylacetic acid (indomethacin, IM) as a model drug, the establishment of high, medium, and low references was completed for the chemical permeation system via in vitro transdermal tests. Furthermore, using chemical penetration enhancers (CPEs) and iontophoresis as references, the percutaneous penetration effect of FCT for IM patches was evaluated using seven species of in vitro diffusion kinetics models and in vitro drug distribution; the IM quantitative analysis method in vivo was established using ultra-performance liquid chromatography-tandem mass spectrometry technology (UPLC-MS/MS), and pharmacokinetic parameters: area under the zero and first moment curves from 0 to last time t (AUC 0-t , AUMC 0-t ), area under the zero and first moment curves from 0 to infinity (AUC 0-∞ , AUMC 0-∞ ), maximum plasma concentration (C max ) and mean residence time (MRT), were used as indicators to evaluate the percutaneous penetration effect of FCT in vivo. Additionally, we used the 3 K factorial design to study the joint synergistic penetration effect on FCT and chemical penetration enhancers. Through scanning electron microscopy (SEM) and transmission electron microscope (TEM) imaging, micro- and ultrastructural changes on the surface of the stratum corneum (SC) were observed to explore the FCT penetration mechanism. In vitro and in vivo skin permeation experiments revealed that both the total cumulative percutaneous amount and in vivo percutaneous absorption amount of IM using FCT were greater than the amount using CPEs and iontophoresis. Firstly, compared with the control group, the indomethacin skin percutaneous rate of the FCT low-intensity group (FCTL) was 35.52%, and the enhancement ratio (ER) at 9 h was 1.76X, roughly equivalent to the penetration enhancing effect of the CPEs and iontophoresis. Secondly, the indomethacin percutaneous ratio of the FCT middle-intensity group (FCTM) and FCT high-intensity group (FCTH) were 47.36% and 54.58%, respectively, while the ERs at 9 h were 3.58X and 8.39X, respectively. Thirdly, pharmacokinetic data showed that in vivo indomethacin percutaneous absorption of the FCT was much higher than that of the control, that of the FCTM was slightly higher than that of the CPE, and that of the FCTM group was significantly higher than all others. Meanwhile, variance analysis indicated that the combination of the FCT penetration enhancement method and the CPE method had beneficial effects in enhancing skin penetration: the significance level of the CPE method was 0.0004, which was lower than 0.001, meaning the difference was markedly significant; the significance level of the FCT was also below 0.0001 and its difference markedly significant. The significance level of factor interaction A × B was lower than 0.0001, indicating that the difference in synergism was markedly significant. Moreover, SEM and TEM images showed that the SC surfaces of Sprague-Dawley rats treated with FCT were damaged, and it was difficult to observe the complete surface structure, with SC pores growing larger and its special "brick structure" becoming looser. This indicated that the barrier function of the skin was broken, thus revealing a potentially major route of skin penetration. FCT, as a new form of transdermal penetration technology, has significant penetration effects with TCM characteristics and is of high clinical value. It is worth promoting its development.

Evaluation of bearing capacity of piles from cone penetration test data : technical summary.

DOT National Transportation Integrated Search

1999-11-01

Among the different in situ tests, cone penetration test (CPT) is considered the most frequently used method for characterization of geomedia. Due to the soft nature of soil deposits in Louisiana, the CPT is considered a perfect tool for characteriza...

Wetting kinetics of nanodroplets on lyophilic nanopillar-arrayed surfaces: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Zong, Diyuan; Yang, Zhen; Duan, Yuanyuan

2017-10-01

Wetting kinetics of water droplets on substrates with lyophilic nanopillars was investigated using molecular dynamics simulations. Early spreading of the droplet is hindered by the nanopillars because of the penetration of the liquid which induce an extra dissipation in the droplet. Droplet spreading is mainly controlled by liquid viscosity and surface tension and not dependent on solid wettability. Propagation of the fringe film is hindered by the enhanced solid wettability because of the energy barrier introduced by the interaction between water molecules and nanopillars which increase with solid wettability.

Characterisation of the membrane affinity of an isoniazide peptide conjugate by tensiometry, atomic force microscopy and sum-frequency vibrational spectroscopy, using a phospholipid Langmuir monolayer model.

PubMed

Hill, Katalin; Pénzes, Csanád Botond; Schnöller, Donát; Horváti, Kata; Bosze, Szilvia; Hudecz, Ferenc; Keszthelyi, Tamás; Kiss, Eva

2010-10-07

Tensiometry, sum-frequency vibrational spectroscopy, and atomic force microscopy were employed to assess the cell penetration ability of a peptide conjugate of the antituberculotic agent isoniazide. Isoniazide was conjugated to peptide (91)SEFAYGSFVRTVSLPV(106), a functional T-cell epitope of the immunodominant 16 kDa protein of Mycobacterium tuberculosis. As a simple but versatile model of the cell membrane a phospholipid Langmuir monolayer at the liquid/air interface was used. Changes induced in the structure of the phospholipid monolayer by injection of the peptide conjugate into the subphase were followed by tensiometry and sum-frequency vibrational spectroscopy. The drug penetrated lipid films were transferred to a solid support by the Langmuir-Blodgett technique, and their structures were characterized by atomic force microscopy. Peptide conjugation was found to strongly enhance the cell penetration ability of isoniazide.

Experimental and theoretical characterization of deep penetration welding threshold induced by 1-μm laser

NASA Astrophysics Data System (ADS)

Zou, J. L.; He, Y.; Wu, S. K.; Huang, T.; Xiao, R. S.

2015-12-01

The deep penetration-welding threshold (DPWT) is the critical value that describes the welding mode transition from the thermal conduction to the deep penetration. The objective of this research is to clarify the DPWT induced by the lasers with wavelength of 1 μm (1-μm laser), based on experimental observation and theoretical analysis. The experimental results indicated that the DPWT was the ratio between laser power and laser spot diameter (P/d) rather than laser power density (P/S). The evaporation threshold was smaller than the DPWT, while the jump threshold of the evaporated mass flux in the molten pool surface was consistent with the DPWT. Based on the force balance between the evaporation recoil pressure and the surface tension pressure at the gas-liquid interface of the molten pool as well as the temperature field, we developed a self-focusing model, which further confirmed the experimental results.

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.

Penetration and aspiration in healthy older adults as assessed during endoscopic evaluation of swallowing.

PubMed

Butler, Susan G; Stuart, Andrew; Markley, Lisa; Rees, Catherine

2009-03-01

A previous article from our group presented data on normal swallowing as assessed during simultaneous manometry and flexible endoscopic evaluation of swallowing (FEES). Because penetration and aspiration events were identified in healthy adults, the question arose, could the presence of the manometric catheter confound normal FEES findings? Thus, a follow-up study was designed to address the effects of catheter condition on healthy older adults as assessed during FEES. Twenty older adults (mean, 78.9 years of age) participated. The participants each contributed 28 swallows, affording a study total of 560 swallows for analyses. The older adults demonstrated penetration on 82 (15%) and aspiration on 18 (3%) of 545 swallows. The numbers of participants who had penetration and aspiration during the study protocol were 75% and 30%, respectively. The older adults demonstrated both penetration and aspiration events irrespective of the presence of a catheter; whether they were drinking milk, water, or barium; whether the bolus was 5 or 10 mL; and whether they took the bolus via syringe or self-administered the bolus with a cup. However, significantly more aspiration was found on thin liquids than on puree or solids. Endoscopic data on normal swallowing physiology were generated. These may serve as an accurate benchmark for clinicians and researchers in the interpretation of dysphagia.

A drop penetration method to measure powder blend wettability.

PubMed

Wang, Yifan; Liu, Zhanjie; Muzzio, Fernando; Drazer, German; Callegari, Gerardo

2018-03-01

Water wettability of pharmaceutical blends affects important quality attributes of final products. We investigate the wetting properties of a pharmaceutical blend lubricated with Magnesium Stearate (MgSt) as a function of the mechanical shear strain applied to the blend. We measure the penetration dynamics of sessile drops deposited on slightly compressed powder beds. We consider a blend composed of 9% Acetaminophen 90% Lactose and 1% MgSt by weight. Comparing the penetration time of water and a reference liquid Polydimethylsiloxane (silicon oil) we obtain an effective cosine of the contact angle with water, based on a recently developed drop penetration method. We repeat the experiments for blends exposed to increasing levels of shear strain and demonstrate a significant decrease in water wettability (decrease in the cosine of the contact angle). The results are consistent with the development of a hydrophobic film coating the powder particles as a result of the increased shear strain. Finally, we show that, as expected dissolution times increase with the level of shear strain. Therefore, the proposed drop penetration method could be used to directly assess the state of lubrication of a pharmaceutical blend and act as a quality control on powder blend attributes before the blend is tableted. Copyright © 2017 Elsevier B.V. All rights reserved.

In situ observations of snow particle size distributions over a cold frontal rainband within an extratropical cyclone

NASA Astrophysics Data System (ADS)

Yang, Jiefan; Lei, Hengchi

2016-02-01

Cloud microphysical properties of a mixed phase cloud generated by a typical extratropical cyclone in the Tongliao area, Inner Mongolia on 3 May 2014, are analyzed primarily using in situ flight observation data. This study is mainly focused on ice crystal concentration, supercooled cloud water content, and vertical distributions of fit parameters of snow particle size distributions (PSDs). The results showed several discrepancies of microphysical properties obtained during two penetrations. During penetration within precipitating cloud, the maximum ice particle concentration, liquid water content, and ice water content were increased by a factor of 2-3 compared with their counterpart obtained during penetration of a nonprecipitating cloud. The heavy rimed and irregular ice crystals obtained by 2D imagery probe as well as vertical distributions of fitting parameters within precipitating cloud show that the ice particles grow during falling via riming and aggregation process, whereas the lightly rimed and pristine ice particles as well as fitting parameters within non-precipitating cloud indicate the domination of sublimation process. During the two cloud penetrations, the PSDs were generally better represented by gamma distributions than the exponential form in terms of the determining coefficient ( R 2). The correlations between parameters of exponential /gamma form within two penetrations showed no obvious differences compared with previous studies.

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2011 CFR

2011-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2012 CFR

2012-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2013 CFR

2013-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2014 CFR

2014-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

Sharing of Tank Information

NASA Technical Reports Server (NTRS)

Tamminga, Joshua D.

2011-01-01

Test Rationale -- Attempt to Address 10% vs. 25+% effects of crater penetration on full scale titanium alloy tanks and comparison to plate tests Utilize Baseline Burst Pressure versus HVI impacted vessels as gauge of effects Examine craters (post test) to determine penetration characteristics on a fluid filled vessel versus plate tests. Examine crater effects leading to vessel failure (if any).

42 CFR Appendix - Tables to Subpart I of Part 84

Code of Federal Regulations, 2014 CFR

2014-10-01

... Test condition Test atmosphere Gas or vapor Concentration (parts per million) Flow rate (liters per... indicated penetration. 2 Relative humidity of test atmosphere will be 95 ±3pct; temperature of test atmosphere will be 25 ±2.5 °C. 3 Maximum allowable CO penetration will be 385 cm 3 during the minimum life...

42 CFR Appendix - Tables to Subpart I of Part 84

Code of Federal Regulations, 2013 CFR

2013-10-01

... Test condition Test atmosphere Gas or vapor Concentration (parts per million) Flow rate (liters per... indicated penetration. 2 Relative humidity of test atmosphere will be 95 ±3pct; temperature of test atmosphere will be 25 ±2.5 °C. 3 Maximum allowable CO penetration will be 385 cm 3 during the minimum life...

42 CFR Appendix - Tables to Subpart I of Part 84

Code of Federal Regulations, 2012 CFR

2012-10-01

... Test condition Test atmosphere Gas or vapor Concentration (parts per million) Flow rate (liters per... indicated penetration. 2 Relative humidity of test atmosphere will be 95 ±3pct; temperature of test atmosphere will be 25 ±2.5 °C. 3 Maximum allowable CO penetration will be 385 cm 3 during the minimum life...

Accuracy of the volume-viscosity swallow test for clinical screening of oropharyngeal dysphagia and aspiration.

PubMed

Clavé, Pere; Arreola, Viridiana; Romea, Maise; Medina, Lucía; Palomera, Elisabet; Serra-Prat, Mateu

2008-12-01

To determine the accuracy of the bedside volume-viscosity swallow test (V-VST) for clinical screening of impaired safety and efficacy of deglutition. We studied 85 patients with dysphagia and 12 healthy subjects. Series of 5-20 mL nectar (295.02 mPa.s), liquid (21.61 mPa.s) and pudding (3682.21 mPa.s) bolus were administered during the V-VST and videofluoroscopy. Cough, fall in oxygen saturation > or =3%, and voice changes were considered signs of impaired safety, and piecemeal deglutition and oropharyngeal residue, signs of impaired efficacy. Videofluoroscopy showed patients had prolonged swallow response (> or =1064 ms); 52.1% had safe swallow at nectar, 32.9%, at liquid (p<0.05), and 80.6% at pudding viscosity (p<0.05); 29.4% had aspirations, and 45.8% oropharyngeal residue. The V-VST showed 83.7% sensitivity and 64.7% specificity for bolus penetration into the larynx and 100% sensitivity and 28.8% specificity for aspiration. Sensitivity of V-VST was 69.2% for residue, 88.4% for piecemeal deglutition, and 84.6% for identifying patients whose deglutition improved by enhancing bolus viscosity. Specificity was 80.6%, 87.5%, and 73.7%, respectively. The V-VST is a sensitive clinical method to identify patients with dysphagia at risk for respiratory and nutritional complications, and patients whose deglutition could be improved by enhancing bolus viscosity. Patients with a positive test should undergo videofluoroscopy.

Antiviral Activity of Crude Hydroethanolic Extract from Schinus terebinthifolia against Herpes simplex Virus Type 1.

PubMed

Nocchi, Samara Requena; Companhoni, Mychelle Vianna Pereira; de Mello, João Carlos Palazzo; Dias Filho, Benedito Prado; Nakamura, Celso Vataru; Carollo, Carlos Alexandre; Silva, Denise Brentan; Ueda-Nakamura, Tânia

2017-04-01

Herpes simplex virus infections persist throughout the lifetime of the host and affect more than 80 % of the humans worldwide. The intensive use of available therapeutic drugs has led to undesirable effects, such as drug-resistant strains, prompting the search for new antiherpetic agents. Although diverse bioactivities have been identified in Schinus terebinthifolia , its antiviral activity has not attracted much attention. The present study evaluated the antiherpetic effects of a crude hydroethanolic extract from the stem bark of S. terebinthifolia against Herpes simplex virus type 1 in vitro and in vivo as well as its genotoxicity in bone marrow in mammals and established the chemical composition of the crude hydroethanolic extract based on liquid chromatography-diode array detector-mass spectrometry and MS/MS. The crude hydroethanolic extract inhibited all of the tested Herpes simplex virus type 1 strains in vitro and was effective in the attachment and penetration stages, and showed virucidal activity, which was confirmed by transmission electron microscopy. The micronucleus test showed that the crude hydroethanolic extract had no genotoxic effect at the concentrations tested. The crude hydroethanolic extract afforded protection against lesions that were caused by Herpes simplex virus type 1 in vivo . Liquid chromatography-diode array detector-mass spectrometry and MS/MS identified 25 substances, which are condensed tannins mainly produced by a B-type linkage and prodelphinidin and procyanidin units. Georg Thieme Verlag KG Stuttgart · New York.

A comparison of two nano-sized particle air filtration tests in the diameter range of 10 to 400 nanometers

NASA Astrophysics Data System (ADS)

Japuntich, Daniel A.; Franklin, Luke M.; Pui, David Y.; Kuehn, Thomas H.; Kim, Seong Chan; Viner, Andrew S.

2007-01-01

Two different air filter test methodologies are discussed and compared for challenges in the nano-sized particle range of 10-400 nm. Included in the discussion are test procedure development, factors affecting variability and comparisons between results from the tests. One test system which gives a discrete penetration for a given particle size is the TSI 8160 Automated Filter tester (updated and commercially available now as the TSI 3160) manufactured by the TSI, Inc., Shoreview, MN. Another filter test system was developed utilizing a Scanning Mobility Particle Sizer (SMPS) to sample the particle size distributions downstream and upstream of an air filter to obtain a continuous percent filter penetration versus particle size curve. Filtration test results are shown for fiberglass filter paper of intermediate filtration efficiency. Test variables affecting the results of the TSI 8160 for NaCl and dioctyl phthalate (DOP) particles are discussed, including condensation particle counter stability and the sizing of the selected particle challenges. Filter testing using a TSI 3936 SMPS sampling upstream and downstream of a filter is also shown with a discussion of test variables and the need for proper SMPS volume purging and filter penetration correction procedure. For both tests, the penetration versus particle size curves for the filter media studied follow the theoretical Brownian capture model of decreasing penetration with decreasing particle diameter down to 10 nm with no deviation. From these findings, the authors can say with reasonable confidence that there is no evidence of particle thermal rebound in the size range.

New solutions to the constant-head test performed at a partially penetrating well

NASA Astrophysics Data System (ADS)

Chang, Y. C.; Yeh, H. D.

2009-05-01

SummaryThe mathematical model describing the aquifer response to a constant-head test performed at a fully penetrating well can be easily solved by the conventional integral transform technique. In addition, the Dirichlet-type condition should be chosen as the boundary condition along the rim of wellbore for such a test well. However, the boundary condition for a test well with partial penetration must be considered as a mixed-type condition. Generally, the Dirichlet condition is prescribed along the well screen and the Neumann type no-flow condition is specified over the unscreened part of the test well. The model for such a mixed boundary problem in a confined aquifer system of infinite radial extent and finite vertical extent is solved by the dual series equations and perturbation method. This approach provides analytical results for the drawdown in the partially penetrating well and the well discharge along the screen. The semi-analytical solutions are particularly useful for the practical applications from the computational point of view.

Alaskan frozen soil impact tests of the B83-C/S and Strategic Earth Penetrator

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

Dockery, H.A.; Clarke, J.B.; Stull, S.P.

To assess the penetrability of the B83 strategic bomb and a Strategic Earth Penetrator design into frozen soil and ice, Lawrence Livermore National Laboratory and Sandia National Laboratories, assisted by the US Air Force and US Army, conducted a series of tests in 1987. In April, Strategic Earth Penetrator units were dropped into multi-year sea ice and frozen tundra near Prudhoe Bay, Alaska. Calculated impact velocity ranged from 200 to 308 ft/s into ice and from 200 to 444 ft/s into frozen tundra. Tests in May include drops of a B83 design with specially designed ogive nose shape, a B83more » with a cap over the production ''cookie cutter'' nose, and a Strategic Earth Penetrator. The May tests were conducted near Fairbanks, Alaska, at Eielson Air Force Base and at Donnelly Flats on the Fort Greely Military Reservation. The type of frozen soil encountered at Eielson was very homogeneous in composition; however. Two drops impacted areas with very thin frozen soil layers at depths of about 24 in. below the surface. Velocities of these drops prior to impact ranged from 256 to 308 ft/s, and peak axial deceleration ranged from 160 to 490 g. The units penetrated to depths of 7.5-12 ft. Three other events impacted in a target area where frozen soil averaging 35 in. thick extended essentially to the surface. We calculated velocities prior to impact at 200-256 ft/s; and penetration depths of 3.2-9.6 ft. The geologic material at Donnelly Flats was primarily a very hard, rocky glacial deposit with a variable degree of ice bonding. Here, the test units dropped from 10,000 ft above ground level and achieved an average calculated velocity of 802 ft/s. Depth of penetration ranged from 7.6 to 13.5 ft.« less

Design, Simulation and Fabrication of Triaxial MEMS High Shock Accelerometer.

PubMed

Zhang, Zhenhai; Shi, Zhiguo; Yang, Zhan; Xie, Zhihong; Zhang, Donghong; Cai, De; Li, Kejie; Shen, Yajing

2015-04-01

On the basis of analyzing the disadvantage of other structural accelerometer, three-axis high g MEMS piezoresistive accelerometer was put forward in order to apply to the high-shock test field. The accelerometer's structure and working principle were discussed in details. The simulation results show that three-axis high shock MEMS accelerometer can bear high shock. After bearing high shock impact in high-shock shooting test, three-axis high shock MEMS accelerometer can obtain the intact metrical information of the penetration process and still guarantee the accurate precision of measurement in high shock load range, so we can not only analyze the law of stress wave spreading and the penetration rule of the penetration process of the body of the missile, but also furnish the testing technology of the burst point controlling. The accelerometer has far-ranging application in recording the typical data that projectile penetrating hard target and furnish both technology guarantees for penetration rule and defend engineering.

The effect of simulated air conditions on N95 filtering facepiece respirators performance.

PubMed

Ramirez, Joel A; O'Shaughnessy, Patrick T

2016-07-01

The objective of this study was to determine the effect of several simulated air environmental conditions on the particle penetration and the breathing resistance of two N95 filtering facepiece respirator (FFR) models. The particle penetration and breathing resistance of the respirators were evaluated in a test system developed to mimic inhalation and exhalation breathing while relative humidity and temperature were modified. Breathing resistance was measured over 120 min using a calibrated pressure transducer under four different temperature and relative humidity conditions without aerosol loading. Particle penetration was evaluated before and after the breathing resistance test at room conditions using a sodium chloride aerosol measured with a scanning mobility particle sizer. Results demonstrated that increasing relative humidity and lowering external temperature caused significant increases in breathing resistance (p < 0.001). However, these same conditions did not influence the penetration or most penetrating particle size of the tested FFRs. The increase in breathing resistance varied by FFR model suggesting that some FFR media are less influenced by high relative humidity.

An electrochemical modeling of lithium-ion battery nail penetration

NASA Astrophysics Data System (ADS)

Chiu, Kuan-Cheng; Lin, Chi-Hao; Yeh, Sheng-Fa; Lin, Yu-Han; Chen, Kuo-Ching

2014-04-01

Nail penetration into a battery pack, resulting in a state of short-circuit and thus burning, is likely to occur in electric car collisions. To demonstrate the behavior of a specific battery when subject to such incidents, a standard nail penetration test is usually performed; however, conducting such an experiment is money consuming. The purpose of this study is to propose a numerical electrochemical model that can simulate the test accurately. This simulation makes two accurate predictions. First, we are able to model short-circuited lithium-ion batteries (LIBs) via electrochemical governing equations so that the mass and charge transfer effect could be considered. Second, the temperature variation of the cell during and after nail penetration is accurately predicted with the help of simulating the temperature distribution of thermal runaway cells by thermal abuse equations. According to this nail penetration model, both the onset of battery thermal runaway and the cell temperature profile of the test are obtained, both of which are well fitted with our experimental results.

Space station integrated wall design and penetration damage control

NASA Technical Reports Server (NTRS)

Coronado, A. R.; Gibbins, M. N.; Wright, M. A.; Stern, P. H.

1987-01-01

A methodology was developed to allow a designer to optimize the pressure wall, insulation, and meteoroid/debris shield system of a manned spacecraft for a given spacecraft configuration and threat environment. The threat environment consists of meteoroids and orbital debris, as specified for an arbitrary orbit and expected lifetime. An overall probability of no penetration is calculated, as well as contours of equal threat that take into account spacecraft geometry and orientation. Techniques, tools, and procedures for repairing an impacted and penetrated pressure wall were developed and tested. These techniques are applied from the spacecraft interior and account for the possibility of performing the repair in a vacuum. Hypervelocity impact testing was conducted to: (1) develop and refine appropriate penetration functions, and (2) determine the internal effects of a penetration on personnel and equipment.

Penetration analysis of projectile with inclined concrete target

NASA Astrophysics Data System (ADS)

Kim, S. B.; Kim, H. W.; Yoo, Y. H.

2015-09-01

This paper presents numerical analysis result of projectile penetration with concrete target. We applied dynamic material properties of 4340 steels, aluminium and explosive for projectile body. Dynamic material properties were measured with static tensile testing machine and Hopkinson pressure bar tests. Moreover, we used three concrete damage models included in LS-DYNA 3D, such as SOIL_CONCRETE, CSCM (cap model with smooth interaction) and CONCRETE_DAMAGE (K&C concrete) models. Strain rate effect for concrete material is important to predict the fracture deformation and shape of concrete, and penetration depth for projectiles. CONCRETE_DAMAGE model with strain rate effect also applied to penetration analysis. Analysis result with CSCM model shows good agreement with penetration experimental data. The projectile trace and fracture shapes of concrete target were compared with experimental data.

Eco-friendly ionic liquid based ultrasonic assisted selective extraction coupled with a simple liquid chromatography for the reliable determination of acrylamide in food samples.

PubMed

Albishri, Hassan M; El-Hady, Deia Abd

2014-01-01

Acrylamide in food has drawn worldwide attention since 2002 due to its neurotoxic and carcinogenic effects. These influences brought out the dual polar and non-polar characters of acrylamide as they enabled it to dissolve in aqueous blood medium or penetrate the non-polar plasma membrane. In the current work, a simple HPLC/UV system was used to reveal that the penetration of acrylamide in non-polar phase was stronger than its dissolution in polar phase. The presence of phosphate salts in the polar phase reduced the acrylamide interaction with the non-polar phase. Furthermore, an eco-friendly and costless coupling of the HPLC/UV with ionic liquid based ultrasonic assisted extraction (ILUAE) was developed to determine the acrylamide content in food samples. ILUAE was proposed for the efficient extraction of acrylamide from bread and potato chips samples. The extracts were obtained by soaking of potato chips and bread samples in 1.5 mol L(-1) 1-butyl-3-methylimmidazolium bromide (BMIMBr) for 30.0 and 60.0 min, respectively and subsequent chromatographic separation within 12.0 min using Luna C18 column and 100% water mobile phase with 0.5 mL min(-1) under 25 °C column temperature at 250 nm. The extraction and analysis of acrylamide could be achieved within 2h. The mean extraction efficiency of acrylamide showed adequate repeatability with relative standard deviation (RSD) of 4.5%. The limit of detection and limit of quantitation were 25.0 and 80.0 ng mL(-1), respectively. The accuracy of the proposed method was tested by recovery in seven food samples giving values ranged between 90.6% and 109.8%. Therefore, the methodology was successfully validated by official guidelines, indicating its reliability to be applied to analysis of real samples, proven to be useful for its intended purpose. Moreover, it served as a simple, eco-friendly and costless alternative method over hitherto reported ones. © 2013 Elsevier B.V. All rights reserved.

Investigation of heat transfer in liquid-metal flows under fusion-reactor conditions

NASA Astrophysics Data System (ADS)

Poddubnyi, I. I.; Pyatnitskaya, N. Yu.; Razuvanov, N. G.; Sviridov, V. G.; Sviridov, E. V.; Leshukov, A. Yu.; Aleskovskiy, K. V.; Obukhov, D. M.

2016-12-01

The effect discovered in studying a downward liquid-metal flow in vertical pipe and in a channel of rectangular cross section in, respectively, a transverse and a coplanar magnetic field is analyzed. In test blanket modules (TBM), which are prototypes of a blanket for a demonstration fusion reactor (DEMO) and which are intended for experimental investigations at the International Thermonuclear Experimental Reactor (ITER), liquid metals are assumed to fulfil simultaneously the functions of (i) a tritium breeder, (ii) a coolant, and (iii) neutron moderator and multiplier. This approach to testing experimentally design solutions is motivated by plans to employ, in the majority of the currently developed DEMO blanket projects, liquid metals pumped through pipes and/or rectangular channels in a transvers magnetic field. At the present time, experiments that would directly simulate liquid-metal flows under conditions of ITER TBM and/or DEMO blanket operation (irradiation with thermonuclear neutrons, a cyclic temperature regime, and a magnetic-field strength of about 4 to 10 T) are not implementable for want of equipment that could reproduce simultaneously the aforementioned effects exerted by thermonuclear plasmas. This is the reason why use is made of an iterative approach to experimentally estimating the performance of design solutions for liquid-metal channels via simulating one or simultaneously two of the aforementioned factors. Therefore, the investigations reported in the present article are of considerable topical interest. The respective experiments were performed on the basis of the mercury magneto hydrodynamic (MHD) loop that is included in the structure of the MPEI—JIHT MHD experimental facility. Temperature fields were measured under conditions of two- and one-sided heating, and data on averaged-temperature fields, distributions of the wall temperature, and statistical fluctuation features were obtained. A substantial effect of counter thermo gravitational convection (TGC) on averaged and fluctuating quantities were found. The development of TGC in the presence of a magnetic field leads to the appearance of low-frequency fluctuations whose anomalously high intensity exceeds severalfold the level of turbulence fluctuations. This effect manifest itself over a broad region of regime parameters. It was confirmed that low-energy fluctuations penetrate readily through the wall; therefore, it is necessary to study this effect further—in particular, from the point of view of the fatigue strength of the walls of liquid-metal channels.

Investigation of heat transfer in liquid-metal flows under fusion-reactor conditions

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

Poddubnyi, I. I., E-mail: poddubnyyii@nikiet.ru; Pyatnitskaya, N. Yu.; Razuvanov, N. G.

2016-12-15

The effect discovered in studying a downward liquid-metal flow in vertical pipe and in a channel of rectangular cross section in, respectively, a transverse and a coplanar magnetic field is analyzed. In test blanket modules (TBM), which are prototypes of a blanket for a demonstration fusion reactor (DEMO) and which are intended for experimental investigations at the International Thermonuclear Experimental Reactor (ITER), liquid metals are assumed to fulfil simultaneously the functions of (i) a tritium breeder, (ii) a coolant, and (iii) neutron moderator and multiplier. This approach to testing experimentally design solutions is motivated by plans to employ, in themore » majority of the currently developed DEMO blanket projects, liquid metals pumped through pipes and/or rectangular channels in a transvers magnetic field. At the present time, experiments that would directly simulate liquid-metal flows under conditions of ITER TBM and/or DEMO blanket operation (irradiation with thermonuclear neutrons, a cyclic temperature regime, and a magnetic-field strength of about 4 to 10 T) are not implementable for want of equipment that could reproduce simultaneously the aforementioned effects exerted by thermonuclear plasmas. This is the reason why use is made of an iterative approach to experimentally estimating the performance of design solutions for liquid-metal channels via simulating one or simultaneously two of the aforementioned factors. Therefore, the investigations reported in the present article are of considerable topical interest. The respective experiments were performed on the basis of the mercury magneto hydrodynamic (MHD) loop that is included in the structure of the MPEI—JIHT MHD experimental facility. Temperature fields were measured under conditions of two- and one-sided heating, and data on averaged-temperature fields, distributions of the wall temperature, and statistical fluctuation features were obtained. A substantial effect of counter thermo gravitational convection (TGC) on averaged and fluctuating quantities were found. The development of TGC in the presence of a magnetic field leads to the appearance of low-frequency fluctuations whose anomalously high intensity exceeds severalfold the level of turbulence fluctuations. This effect manifest itself over a broad region of regime parameters. It was confirmed that low-energy fluctuations penetrate readily through the wall; therefore, it is necessary to study this effect further—in particular, from the point of view of the fatigue strength of the walls of liquid-metal channels.« less

Evaluation of consolidation characteristics of cohesive soils from piezocone penetration tests.

DOT National Transportation Integrated Search

2004-01-01

The piezocone penetration test (PCPT) has gained wide popularity and acknowledgement as a preferred in-situ device for subsurface investigation and soil characterization. The PCPT measurements can be utilized for soil identification and the evaluatio...

A Theoretical Study of Flow Structure and Radiation for Multiphase Turbulent Diffusion Flames

DTIC Science & Technology

1990-03-01

density function. According to the axial void fraction profile in Fig. 24, the flame length (the total penetration length) extends to x/d=150. By referring...temperature because of subcooling effect. Decreasing liquid temperature will increase condensation which in turn reduces the flame length as defined by

7 CFR 2902.42 - Wood and concrete sealers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 15 2011-01-01 2011-01-01 false Wood and concrete sealers. 2902.42 Section 2902.42... Items § 2902.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage caused by...

7 CFR 2902.42 - Wood and concrete sealers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Wood and concrete sealers. 2902.42 Section 2902.42... Items § 2902.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage caused by...

Effect of Liquid Viscosity on Dispersion of Quasi-Lamb Waves in an Elastic-Layer-Viscous-Liquid-Layer System

NASA Astrophysics Data System (ADS)

Guz, A. N.; Bagno, A. M.

2017-07-01

The dispersion curves are constructed and propagation of quasi-Lamb waves are studied for wide range of frequencies based on the Navier -Stokes three-dimensional linearized equations for a viscous liquid and linear equations of the classical theory of elasticity for an elastic layer. For a thick liquid layer, the effect of the viscosity of the liquid and the thickness of elastic and liquid layers on the phase velocities and attenuation coefficients of quasi-Lamb modes is analyzed. It is shown that in the case of a thick liquid layer for all modes, there are elastic layers of certain thickness with minimal effect of liquid viscosity on the phase velocities and attenuation coefficients of modes. It is also discovered that for some modes, there are both certain thicknesses and certain ranges of thickness where the effect of liquid viscosity on the phase velocities and attenuation coefficients of these modes is considerable. We ascertain that liquid viscosity promotes decrease of the penetration depth of the lowest quasi-Lamb mode into the liquid. The developed approach and the obtained results make it possible to ascertain for wave processes the limits of applicability of the model of ideal compressible fluid. Numerical results in the form of graphs are adduced and analyzed.

Investigation of Underground Hydrocarbon Leakage using Ground Penetrating Radar

NASA Astrophysics Data System (ADS)

Srigutomo, Wahyu; Trimadona; Agustine, Eleonora

2016-08-01

Ground Penetrating Radar (GPR) survey was carried out in several petroleum plants to investigate hydrocarbon contamination beneath the surface. The hydrocarbon spills are generally recognized as Light Non-Aqueous Phase Liquids (LNAPL) if the plume of leakage is distributed in the capillary fringe above the water table and as Dense Non-Aqueous Phase Liquids (DNAPL) if it is below the water table. GPR antennas of 200 MHz and 400 MHz were deployed to obtain clear radargrams until 4 m deep. In general, the interpreted radargram sections indicate the presence of surface concrete layer, the compacted silty soill followed by sand layer and the original clayey soil as well as the water table. The presence of hydrocarbon plumes are identified as shadow zones (radar velocity and intensity contrasts) in the radargram that blur the layering pattern with different intensity of reflected signal. Based on our results, the characteristic of the shadow zones in the radargram is controlled by several factors: types of hydrocarbon (fresh or bio-degraded), water moisture in the soil, and clay content which contribute variation in electrical conductivity and dielectric constants of the soil.

Chemical-Specific Representation of Air-Soil Exchange and Soil Penetration in Regional Multimedia Models

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

McKone, T.E.; Bennett, D.H.

2002-08-01

In multimedia mass-balance models, the soil compartment is an important sink as well as a conduit for transfers to vegetation and shallow groundwater. Here a novel approach for constructing soil transport algorithms for multimedia fate models is developed and evaluated. The resulting algorithms account for diffusion in gas and liquid components; advection in gas, liquid, or solid phases; and multiple transformation processes. They also provide an explicit quantification of the characteristic soil penetration depth. We construct a compartment model using three and four soil layers to replicate with high reliability the flux and mass distribution obtained from the exact analyticalmore » solution describing the transient dispersion, advection, and transformation of chemicals in soil with fixed properties and boundary conditions. Unlike the analytical solution, which requires fixed boundary conditions, the soil compartment algorithms can be dynamically linked to other compartments (air, vegetation, ground water, surface water) in multimedia fate models. We demonstrate and evaluate the performance of the algorithms in a model with applications to benzene, benzo(a)pyrene, MTBE, TCDD, and tritium.« less

Orbital SAR and Ground-Penetrating Radar for Mars: Complementary Tools in the Search for Water

NASA Technical Reports Server (NTRS)

Campbell, B. A.; Grant, J. A.

2000-01-01

The physical structure and compositional variability of the upper martian crust is poorly understood. Optical and infrared measurements probe at most the top few cm of the surface layer and indicate the presence of layered volcanics and sediments, but it is likely that permafrost, hydrothermal deposits, and transient liquid water pockets occur at depths of meters to kilometers within the crust. An orbital synthetic aperture radar (SAR) can provide constraints on surface roughness, the depth of fine-grained aeolian or volcanic deposits, and the presence of strongly absorbing near-surface deposits such as carbonates. This information is crucial to the successful landing and operation of any rover designed to search for subsurface water. A rover-based ground-penetrating radar (GPR) can reveal layering in the upper crust, the presence of erosional or other subsurface horizons, depth to a permafrost layer, and direct detection of near-surface transient liquid water. We detail here the radar design parameters likely to provide the best information for Mars, based on experience with SAR and GPR in analogous terrestrial or planetary environments.

Novel nanometer-level uniform amorphous carbon coating for boron powders by direct pyrolysis of coronene without solvent.

PubMed

Ye, ShuJun; Song, MingHui; Kumakura, Hiroaki

2015-01-30

A 3 nm coronene coating and a 4 nm amorphous carbon coating with a uniform shell-core encapsulation structure for nanosized boron (B) powders are formed by a simple process in which coronene is directly mixed with boron particles without a solvent and heated at 520 °C for 1 h or at 630 °C for 3 h in a vacuum-sealed silica tube. Coronene has a melting point lower than its decomposition temperature, which enables liquid coronene to cover B particles by liquid diffusion and penetration without the need for a solvent. The diffusion and penetration of coronene can extend to the boundaries of particles and to inside the agglomerated nanoparticles to form a complete shell-core encapsulated structure. As the temperature is increased, thermal decomposition of coronene on the B particles results in the formation of a uniform amorphous carbon coating layer. This novel and simple nanometer-level uniform amorphous carbon coating method can possibly be applied to many other powders; thus, it has potential applications in many fields at low cost.

Dynamic cone penetration tests in granular media: Determination of the tip's dynamic load-penetration curve

NASA Astrophysics Data System (ADS)

Escobar, E.; Benz, M.; Gourvès, R.; Breul, P.

2013-06-01

In this article a two-dimensional discrete numerical model, realized in PFC2D, is presented. This model is used in the dynamic penetration tests in a granular medium. Its objective being the validation of the measurement technique offered by Panda 3® (Benz et al. 2011) which is designed to calculate the tip's load-penetration curve for each impact in the soil where different parameters are used. To do so, we have compared the results obtained by calculation during the impacts to those measured directly in the model of a penetrometer through the installation of the gauges at the cone.

Results of the mole penetration tests in different materials

NASA Astrophysics Data System (ADS)

Wawrzaszek, Roman; Seweryn, Karol; Grygorczuk, Jerzy; Banaszkiewicz, Marek; Rybus, Tomasz; Wisniewski, Lukasz; Neal, Clive R.; Huang, Shaopeng

2010-05-01

Mole devices are low velocity, medium to high energy, self-driven penetrators, designed as a carrier of different sensors for in situ investigations of subsurface layers of planetary bodies. The maximum insertion depth of such devices is limited by energy of single mole's stroke and soil resistance for the dynamic penetration. A mole penetrator ‘KRET' has been designed, developed, and successfully tested at Space Research Centre PAS in Poland. The principle of operation of the mole bases on the interaction between three masses: the cylindrical casing, the hammer, and the rest of the mass, acting as a support mass. This approach takes advantage of the MUPUS penetrator (a payload of Philae lander on Rosetta mission) insertion tests knowledge. Main parameters of the mole KRET are listed below: - outer diameter: 20.4mm, - length: 330mm, - total mass: 488g, - energy of the driving spring: 2.2J, - average power consumption: 0.28W, - average insertion progress/stroke: 8.5mm, The present works of Space Research Center PAS team are focused on three different activities. First one includes investigations of the mole penetration effectiveness in the lunar analogues (supported by ESA PECS project). Second activity, supported by Polish national fund, is connected with numerical calculation of the heat flow investigations and designing and developing the Heat Flow Probe Hardware Component (HPHC) for L-GIP NASA project. It's worth noting that L-GIP project refers to ILN activity. Last activity focuses on preparing the second version of the mole ready to work in low thermal and pressure conditions. Progress of a mole penetrator in granular medium depends on the mechanical properties of this medium. The mole penetrator ‘KRET' was tested in different materials: dry quartz sand (0.3 - 0.8 grain size), wet quartz sand, wheat flour and lunar regolith mechanical simulant - Chemically Enhanced OB-1 (CHENOBI). Wheat flour was selected due to its high cohesion rate and small grain size. Influence of the material compaction on the mole progress was also investigated. For these tests the small testbed has been used. It allowed us to test our mole penetrator up to the depth of 0.5 meters. Obtained results show that 'KRET' is able to penetrate even compacted lunar regolith simulant CHENOBI with minimum progress rate about 2mm per stroke. Moreover, we have confirmed that the mole works properly in both materials with low and high cohesion.

A Randomized Trial Comparing Two Tongue-Pressure Resistance Training Protocols for Post-Stroke Dysphagia.

PubMed

Steele, Catriona M; Bayley, Mark T; Peladeau-Pigeon, Melanie; Nagy, Ahmed; Namasivayam, Ashwini M; Stokely, Shauna L; Wolkin, Talia

2016-06-01

The objective of this study was to compare the outcomes of two tongue resistance training protocols. One protocol ("tongue-pressure profile training") emphasized the pressure-timing patterns that are typically seen in healthy swallows by focusing on gradual pressure release and saliva swallowing tasks. The second protocol ("tongue-pressure strength and accuracy training") emphasized strength and accuracy in tongue-palate pressure generation and did not include swallowing tasks. A prospective, randomized, parallel allocation trial was conducted. Of 26 participants who were screened for eligibility, 14 received up to 24 sessions of treatment. Outcome measures of posterior tongue strength, oral bolus control, penetration-aspiration and vallecular residue were made based on videofluoroscopy analysis by blinded raters. Complete data were available for 11 participants. Significant improvements were seen in tongue strength and post-swallow vallecular residue with thin liquids, regardless of treatment condition. Stage transition duration (a measure of the duration of the bolus presence in the pharynx prior to swallow initiation, which had been chosen to capture impairments in oral bolus control) showed no significant differences. Similarly, significant improvements were not seen in median scores on the penetration-aspiration scale. This trial suggests that tongue strength can be improved with resistance training for individuals with tongue weakness following stroke. We conclude that improved penetration-aspiration does not necessarily accompany improvements in tongue strength; however, tongue-pressure resistance training does appear to be effective for reducing thin liquid vallecular residue.

The skin reservoir of sulphur mustard.

PubMed

Hattersley, I J; Jenner, J; Dalton, C; Chilcott, R P; Graham, J S

2008-09-01

Studies of the percutaneous reservoir of sulphur mustard (HD) formed during absorption carried out during WWI and WWII are inconclusive. More recent studies have indicated that a significant amount of unreacted HD remains in human epidermal membranes during percutaneous penetration studies in vitro. The present study investigated the nature and persistence of the HD reservoir formed during in vitro penetration studies using dermatomed slices of human and pig skin (0.5mm thick). Amounts of (14)C-HD that (a) penetrated, (b) remained on the surface, (c) were extractable from and (d) remained in the skin after extraction were estimated by liquid scintillation counting (confirmed using GC-MS analysis). The results demonstrated that there is a reservoir of HD in human and pig skin for up to 24 h after contamination of the skin surface in vitro with liquid agent. At least some of this reservoir could be extracted with acetonitrile, and the amounts of extracted and unextracted HD exceed the amount required to produce injury in vivo by at least 20 fold. The study demonstrated the presence of a reservoir whether the skin was covered (occluded) or left open to the air (unoccluded). The study concluded that the extractable reservoir was significant in terms of the amount of HD required to induce a vesicant response in human skin. The extractable reservoir was at least 20 times the amount required per cm(2) estimated to cause a response in all of the human population, as defined by studies carried out in human volunteers during the 1940s.

Investigation of the interaction dynamics of a pair of laser-induced bubbles generated at the same time through double-exposure strobe method and numerical simulations

NASA Astrophysics Data System (ADS)

Han, Bing; Liu, Liu; Ni, Xiao-Wu

2017-08-01

In order to understand the interaction dynamics of a pair of laser-induced bubbles, a double-exposure strobe photography experimental setup is build up to study the temporal evolution of the bubble pairs and to measure the transient bubble-interface moving speed. The interaction mechanisms of the bubble pairs are discussed together with the numerical results obtained through OpenFOAM. It is shown that the direction and the velocity of the jetting could be controlled by the relative size and the relative initiation distance of the bubble pair, when the bubbles are generated at the same time, i.e., in-phase. The liquid jet is considered to be a penetrating jet. The jet is originated from the smaller bubble and clearly protruding outside of the bigger bubble. The parameter space of the relative size and the initiation distance of the bubble pair allowing the formation of the penetrating jet are very narrow. It is concluded that the liquid jet induced by the bubble interactions resulted from the collapse and the rebound of the smaller bubble nearby the bigger bubble. This is defined as the "catapult effect." Such a directional liquid transportation is a promising tool as a micro-injector or a micro-pump. The investigation results could be also supplementary to the understandings of the bubble dynamics.

Results of analyses performed on soil adjacent to penetrators emplaced into sediments at McCook, Nebraska, January 1976. [simulated penetration into wind-deposited sediments on Martian plains

NASA Technical Reports Server (NTRS)

Blanchard, M.; Bunch, T.; Davis, A.; Kyte, F.; Shade, H.; Erlichman, J.; Polkowski, G.

1977-01-01

During 1976 several penetrators (full and 0.58 scale) were dropped into a test site McCook, Nebraska. The McCook site was selected because it simulated penetration into wind-deposited sediments (silts and sands) on Martian plains. The physical and chemical modifications found in the sediment after the penetrators' impact are described. Laboratory analyses have shown mineralogical and elemental changes are produced in the sediment next to the penetrator. Optical microscopy studies of material next to the skin of the penetrator revealed a layer of glassy material about 75 microns thick. Elemental analysis of a 0-1-mm layer of sediment next to the penetrator revealed increased concentrations for Cr, Fe, Ni, Mo, and reduced concentrations for Mg, Al Si, P, K, and Ca. The Cr, Fe, Ni, and Mo were in fragments abraded from the penetrator. Mineralogical changes occurring in the sediment next to the penetrator included the introduction of micron-size grains of alpha iron and several hydrated iron oxide minerals. The newly formed silicate minerals include metastable phases of silica (cristobalite, lechatelierite, and opal). The glassy material was mostly opal which formed when the host minerals (mica, calcite, and clay) decomposed. In summary, contaminants introduced by the penetrator occur up to 2 mm away from the penetrator's skin. Although volatile elements do migrate and new minerals are formed during the destruction of host minerals in the sediment, no changes were observed beyond the 2-mm distance. The analyses indicate 0.58-scale penetrators do effectively simulate full-scale testing for soil modification effects.

Initial basalt target site selection evaluation for the Mars penetrator drop test

NASA Technical Reports Server (NTRS)

Bunch, T. E.; Quaide, W. L.; Polkowski, G.

1976-01-01

Potential basalt target sites for an air drop penetrator test were described and the criteria involved in site selection were discussed. A summary of the background field geology and recommendations for optimum sites are also presented.

Guidelines for cone penetration test : performance and design

DOT National Transportation Integrated Search

1978-07-01

This manual presents procedures and guidelines applicable to the use of the cone penetration test. Dr. Schmertmann prepared this manual in February 1977 and made minor additions in May 1978. It represents his interpretation of the state-of-the-art in...

Correlation of engineering parameters of the presumpscot formation to the seismic cone penetration test (SCPTU).

DOT National Transportation Integrated Search

2015-08-01

The seismic cone penetration test with pore pressure measurement (SCPTu) is a geotechnical investigation technique which : involves pushing a sensitized cone into the subsurface at a constant rate while continuously measuring tip resistance, sleeve :...

Mixing of an Airblast-atomized Fuel Spray Injected into a Crossflow of Air

NASA Technical Reports Server (NTRS)

Leong, May Y.; McDonell, Vincent G.; Samuelsen, G. Scott

2000-01-01

The injection of a spray of fuel droplets into a crossflow of air provides a means of rapidly mixing liquid fuel and air for combustion applications. Injecting the liquid as a spray reduces the mixing length needed to accommodate liquid breakup, while the transverse injection of the spray into the air stream takes advantage of the dynamic mixing induced by the jet-crossflow interaction. The structure of the spray, formed from a model plain-jet airblast atomizer, is investigated in order to determine and understand the factors leading to its dispersion. To attain this goal, the problem is divided into the following tasks which involve: (1) developing planar imaging techniques that visualize fuel and air distributions in the spray, (2) characterizing the airblast spray without a crossflow, and (3) characterizing the airblast spray upon injection into a crossflow. Geometric and operating conditions are varied in order to affect the atomization, penetration, and dispersion of the spray into the crossflow. The airblast spray is first characterized, using imaging techniques, as it issues into a quiescent environment. The spray breakup modes are classified in a liquid Reynolds number versus airblast Weber number regime chart. This work focuses on sprays formed by the "prompt" atomization mode, which induces a well-atomized and well-dispersed spray, and which also produces a two-lobed liquid distribution corresponding to the atomizing air passageways in the injector. The characterization of the spray jet injected into the crossflow reveals the different processes that control its dispersion. Correlations that describe the inner and outer boundaries of the spray jet are developed, using the definition of a two-phase momentum-flux ratio. Cross-sections of the liquid spray depict elliptically-shaped distributions, with the exception of the finely-atomized sprays which show kidney-shaped distributions reminiscent of those obtained in gaseous jet in crossflow systems. A droplet trajectory analysis overpredicts the liquid mass penetration, and indicates a need for a more rigorous model to account for the three-dimensional mixing field induced by the jet-crossflow interaction. Nonetheless, the general procedures and criteria that are outlined can be used to efficiently assess and compare the quality of sprays formed under different conditions.

Effects of a Red Marker Dye on Aedes and Culex Larvae: Are There Implications for Operational Mosquito Control?

PubMed

Unlu, Isik; Leisnham, Paul T; Williams, Gregory M; Klingler, Kim; Dow, Garrett W; Kirchoff, Nicole; Jin, Sophie; Delisi, Nicholas; Montenegro, Katherine; Faraji, Ary

2015-12-01

Marker dyes are often mixed with liquid insecticide formulations prior to field applications to accurately determine the characteristics and penetration of droplets into targeted habitats. We have been using FD&C Red 40 Granular DM food dye at the rate of 20 g/liter in liquid solutions of Bacillus thuringiensis israelensis (Bti) for area-wide larvicide applications against the Asian tiger mosquito, Aedes albopictus. The Bti and dye mix ratio has been recommended by pesticide manufacturers for testing under operational conditions, but no data exist on the effects of the dye itself on mosquito larvae. We tested the effects of the FD&C Red 40 food dye in laboratory bioassays against different strains of Ae. albopictus (New Jersey and Maryland) and Culex pipiens pipiens (Utah) at rates of 0.039 to 80.0 g/liter. We also conducted field application trials to measure dye concentrations up to 100 m downwind when mixed and applied according to manufacturer instructions. In laboratory bioassays, we found that mean survival in cups with dye were significantly different from the controls beginning at 10.0 g/liter for New Jersey Ae. albopictus and at 20.0 g/liter for Maryland Ae. albopictus and Utah Cx. p. pipiens. In field application trials, we recorded a maximum volume density of 1,152.8 nl/cm(2) and calculated the maximum concentration of dye at 9.09 × 10(-3) g/liter. Our results showed that although we detected greater effects of dye on Ae. albopictus in New Jersey experiments than Ae. albopictus in Maryland and Cx. p. pipiens from Utah, concentrations of the dye during operational applications were at least 1,100 times below concentrations that exhibited toxic effects for either species in the laboratory, suggesting that the dye will not interfere with accuracy of field bioassays. Our results conclusively demonstrate that the addition of the FD&C Red 40 marker dye does not alter the efficacy of the pesticide formulation by skewing results, but rather provides a valuable addition to accurately determine pesticide penetration and spectrum by discriminating between intended pesticide and other potential pollutants.

Drop Impact on Hairy Surfaces

NASA Astrophysics Data System (ADS)

Nasto, Alice; Hosoi, Anette

2017-11-01

Using a combination of experiments and theory, we investigate the effect of a millimeter-scale hairy texture on impact of liquid drops. By varying the speed of the drop at impact and the spacing of the hairs, we observe a variety of behaviors. For dense hairs and low impact velocity, the liquid drop sits on top of the hair, similar to a Cassie-Baxter state. For higher impact velocity, and intermediate to high density of hairs, the drops penetrate through the surface, but the hairs resist their spreading. For low hair density and high impact velocity, the drops impact and splash.

HMO penetration and quality of care: the case of breast cancer.

PubMed

Decker, S L; Hempstead, K

1999-01-01

In theory, health maintenance organizations (HMOs) receiving a fixed payment rate per enrolled member have an incentive to coordinate services and emphasize prevention and early detection of disease in order to minimize costs of care. This article tests whether higher HMO penetration rates across counties in the United States and across time improve the use of mammography services, the chance of early rather than late detection of breast cancer, and ultimately improve breast cancer survival. We use two data sets to test the effect of HMO penetration on use of breast cancer services and on breast cancer health outcomes for women aged 55 to 64 years. These data sources are matched with county-level data on HMO penetration and other market variables from the Bureau of Health Profession's Area Resource File. Results of logit regression show evidence that HMO penetration positively affects the probability of recent mammography receipt. However, we do not find a statistically significant relationship between HMO penetration and either stage of diagnosis or breast cancer survival.

Evaluation of bearing capacity of piles from cone penetration test data.

DOT National Transportation Integrated Search

1999-11-01

This study presents an evaluation of the performance of eight cone penetration test (CPT) methods in predicting the ultimate load carrying capacity of square precast prestressed concrete (PPC) piles driven into Louisiana soils. A search in the DOTD f...

A continuous intrusion miniature cone penetration test system for transportation applications : final report.

DOT National Transportation Integrated Search

1999-01-01

The electronic cone penetrometer is a popular in situ investigation tool for site characterization. This research report describes the application of this proven concept of the cone penetration test (CPT) to highway design and construction control by...

The Rheological Properties of Lipid Monolayers Modulate the Incorporation of l-Ascorbic Acid Alkyl Esters.

PubMed

Díaz, Yenisleidy de Las Mercedes Zulueta; Mottola, Milagro; Vico, Raquel V; Wilke, Natalia; Fanani, María Laura

2016-01-19

In this work, we tested the hypothesis that the incorporation of amphiphilic drugs into lipid membranes may be regulated by their rheological properties. For this purpose, two members of the l-ascorbic acid alkyl esters family (ASCn) were selected, ASC16 and ASC14, which have different rheological properties when organized at the air/water interface. They are lipophilic forms of vitamin C used in topical pharmacological preparations. The effect of the phase state of the host lipid membranes on ASCn incorporation was explored using Langmuir monolayers. Films of pure lipids with known phase states have been selected, showing liquid-expanded, liquid-condensed, and solid phases as well as pure cholesterol films in liquid-ordered state. We also tested ternary and quaternary mixed films that mimic the properties of cholesterol containing membranes and of the stratum corneum. The compressibility and shear properties of those monolayers were assessed in order to define its phase character. We found that the length of the acyl chain of the ASCn compounds induces differential changes in the rheological properties of the host membrane and subtly regulates the kinetics and extent of the penetration process. The capacity for ASCn uptake was found to depend on the phase state of the host film. The increase in surface pressure resultant after amphiphile incorporation appears to be a function of the capacity of the host membrane to incorporate such amphiphile as well as the rheological response of the film. Hence, monolayers that show a solid phase state responded with a larger surface pressure increase to the incorporation of a comparable amount of amphiphile than liquid-expanded ones. The cholesterol-containing films, including the mixture that mimics stratum corneum, allowed a very scarce ASCn uptake independently of the membrane diffusional properties. This suggests an important contribution of Cho on the maintenance of the barrier function of stratum corneum.

Liquid-induced colour change in a beetle: the concept of a photonic cell.

PubMed

Mouchet, Sébastien R; Van Hooijdonk, Eloise; Welch, Victoria L; Louette, Pierre; Colomer, Jean-François; Su, Bao-Lian; Deparis, Olivier

2016-01-13

The structural colour of male Hoplia coerulea beetles is notable for changing from blue to green upon contact with water. In fact, reversible changes in both colour and fluorescence are induced in this beetle by various liquids, although the mechanism has never been fully explained. Changes enacted by water are much faster than those by ethanol, in spite of ethanol's more rapid spread across the elytral surface. Moreover, the beetle's photonic structure is enclosed by a thin scale envelope preventing direct contact with the liquid. Here, we note the presence of sodium, potassium and calcium salts in the scale material that mediate the penetration of liquid through putative micropores. The result leads to the novel concept of a "photonic cell": namely, a biocompatible photonic structure that is encased by a permeable envelope which mediates liquid-induced colour changes in that photonic structure. Engineered photonic cells dispersed in culture media could revolutionize the monitoring of cell-metabolism.

Liquid-induced colour change in a beetle: the concept of a photonic cell

PubMed Central

Mouchet, Sébastien R.; Van Hooijdonk, Eloise; Welch, Victoria L.; Louette, Pierre; Colomer, Jean-François; Su, Bao-Lian; Deparis, Olivier

2016-01-01

The structural colour of male Hoplia coerulea beetles is notable for changing from blue to green upon contact with water. In fact, reversible changes in both colour and fluorescence are induced in this beetle by various liquids, although the mechanism has never been fully explained. Changes enacted by water are much faster than those by ethanol, in spite of ethanol’s more rapid spread across the elytral surface. Moreover, the beetle’s photonic structure is enclosed by a thin scale envelope preventing direct contact with the liquid. Here, we note the presence of sodium, potassium and calcium salts in the scale material that mediate the penetration of liquid through putative micropores. The result leads to the novel concept of a “photonic cell”: namely, a biocompatible photonic structure that is encased by a permeable envelope which mediates liquid-induced colour changes in that photonic structure. Engineered photonic cells dispersed in culture media could revolutionize the monitoring of cell-metabolism. PMID:26758681

Superphobicity/philicity Janus Fabrics with Switchable, Spontaneous, Directional Transport Ability to Water and Oil Fluids

PubMed Central

Zhou, Hua; Wang, Hongxia; Niu, Haitao; Lin, Tong

2013-01-01

Herein we demonstrate that switchable, spontaneous, directional-transport ability to both water and oil fluids can be created on fabric materials through wet-chemistry coating and successive UV irradiation treatment. When the fabric showed directional transport to a liquid, it prevented liquids of higher surface tension from penetration, but allowed liquids of lower surface tension to permeate, from either side. The directional transport ability can be switched from one fluid to another simply by heating the fabric at an elevated temperature and then re-irradiating the fabric with UV light for required period of time. By attaching liquid drops vertically upwards to a horizontally-laid fabric, we further demonstrated that this novel directional fluid transport was an automatic process driven by surface property alone, irrespective of gravity's effect. This novel fabric may be useful for development of “smart” textiles and functional membranes for various applications. PMID:24129357

Keyhole and weld shapes for plasma arc welding under normal and zero gravity

NASA Technical Reports Server (NTRS)

Keanini, R. G.; Rubinsky, B.

1990-01-01

A first order study of the interfacial (keyhole) shape between a penetrating argon plasma arc jet and a stationary liquid metal weld pool is presented. The interface is determined using the Young-Laplace equation by assuming that the plasma jet behaves as a one-dimensional ideal gas flow and by neglecting flow within the weld pool. The solution for the keyhole shape allows an approximate determination of the liquid-solid metal phase boundary location based on the assumption that the liquid melt is a stagnant thermal boundary layer. Parametric studies examine the effect of plasma mass flow rate, initial plasma enthalpy, liquid metal surface tension, and jet shear on weldment shape under both normal and zero gravity. Among the more important findings of this study is that keyhole and weld geometries are minimally affected by gravity, suggesting that data gathered under gravity can be used in planning in-space welding.

Electrical Textile Valves for Paper Microfluidics.

PubMed

Ainla, Alar; Hamedi, Mahiar M; Güder, Firat; Whitesides, George M

2017-10-01

This paper describes electrically-activated fluidic valves that operate based on electrowetting through textiles. The valves are fabricated from electrically conductive, insulated, hydrophobic textiles, but the concept can be extended to other porous materials. When the valve is closed, the liquid cannot pass through the hydrophobic textile. Upon application of a potential (in the range of 100-1000 V) between the textile and the liquid, the valve opens and the liquid penetrates the textile. These valves actuate in less than 1 s, require low energy (≈27 µJ per actuation), and work with a variety of aqueous solutions, including those with low surface tension and those containing bioanalytes. They are bistable in function, and are, in a sense, the electrofluidic analog of thyristors. They can be integrated into paper microfluidic devices to make circuits that are capable of controlling liquid, including autonomous fluidic timers and fluidic logic. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Superphobicity/philicity Janus Fabrics with Switchable, Spontaneous, Directional Transport Ability to Water and Oil Fluids

NASA Astrophysics Data System (ADS)

Zhou, Hua; Wang, Hongxia; Niu, Haitao; Lin, Tong

2013-10-01

Herein we demonstrate that switchable, spontaneous, directional-transport ability to both water and oil fluids can be created on fabric materials through wet-chemistry coating and successive UV irradiation treatment. When the fabric showed directional transport to a liquid, it prevented liquids of higher surface tension from penetration, but allowed liquids of lower surface tension to permeate, from either side. The directional transport ability can be switched from one fluid to another simply by heating the fabric at an elevated temperature and then re-irradiating the fabric with UV light for required period of time. By attaching liquid drops vertically upwards to a horizontally-laid fabric, we further demonstrated that this novel directional fluid transport was an automatic process driven by surface property alone, irrespective of gravity's effect. This novel fabric may be useful for development of ``smart'' textiles and functional membranes for various applications.

Force microscopy of layering and friction in an ionic liquid

NASA Astrophysics Data System (ADS)

Hoth, Judith; Hausen, Florian; Müser, Martin H.; Bennewitz, Roland

2014-07-01

The mechanical properties of the ionic liquid 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate ([Py1,4][FAP]) in confinement between a SiOx and a Au(1 1 1) surface are investigated by means of atomic force microscopy (AFM) under electrochemical control. Up to 12 layers of ion pairs can be detected through force measurements while approaching the tip of the AFM to the surface. The particular shape of the force versus distance curve is explained by a model for the interaction between tip, gold surface and ionic liquid, which assumes an exponentially decaying oscillatory force originating from bulk liquid density correlations. Jumps in the tip-sample distance upon approach correspond to jumps of the compliant force sensor between branches of the oscillatory force curve. Frictional force between the laterally moving tip and the surface is detected only after partial penetration of the last double layer between tip and surface.

NONDESTRUCTIVE QUALITY CONTROL: SOME SPECIAL METHODS OF IRRADIATION TESTING

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

Van der Klis, T.

1961-06-10

S>Various methods, using open radioactive sources are discussed. In one method, oil is used containing Pd/sup 109/ which is adsorbed by Mg compounds with which the object to be tested is covered after it has been enveloped in a photographic film. Another method consists of coking the material in the radioactive oil and then scanning it with a suitable detector. A third method, applied especially to porous materials, uses pressure to promote the penetration of the radioactive oil into the cracks and fissures. The filtered particle technique is also used for detection of cracks or cavities in porous materials, suchmore » as ceramics, cement, graphite pressed powdered metals, and sintered carbides. In this method, radioactive liquids are used along with fluid fluorescent substances. Finally, a method is mentioned in which radioactive powder is made to adhere to the surface of the investigated objects by means of an electrostatic charge. This method is used for quality control of china, glass, email, and electric insulation material. (OID)« less

Detection of tightly closed flaws by nondestructive testing (NDT) methods in steel and titanium

NASA Technical Reports Server (NTRS)

Rummel, W. D.; Rathke, R. A.; Todd, P. H., Jr.; Tedrow, T. L.; Mullen, S. J.

1976-01-01

X-radiographic, liquid penetrant, ultrasonic, eddy current and magnetic particle testing techniques were optimized and applied to the evaluation of 4340 steel (180 KSI-UTS) and 6Al-4V titanium (STA) alloy specimens. Sixty steel specimens containing a total of 176 fatigue cracks and 60 titanium specimens containing a total of 135 fatigue cracks were evaluated. The cracks ranged in length from .043 cm (0.017 inch) to 1.02 cm (.400 inch) and in depth from .005 cm (.002 inch) to .239 cm (.094 inch) for steel specimens. Lengths ranged from .048 cm (0.019 inch) to 1.03 cm (.407 inch) and depths from 0.010 cm (.004 inch) to .261 cm (0.103 inch) for titanium specimens. Specimen thicknesses were nominally .152 cm (0.060 inch) and 0.635 cm (0.250 inch) and surface finishes were nominally 125 rms. Specimens were evaluated in the "as machined" surface condition, after etch surface and after proof loading in a randomized inspection sequence.

Wet voice as a sign of penetration/aspiration in Parkinson's disease: does testing material matter?

PubMed

Sampaio, Marília; Argolo, Natalie; Melo, Ailton; Nóbrega, Ana Caline

2014-10-01

Wet voice is a perceptual vocal quality that is commonly used as an indicator of penetration and/or aspiration in clinical swallowing assessments and bedside screening tests. Our aim was to describe the clinimetric characteristics of this clinical sign using various fluid materials and one solid food in the Parkinson's disease (PD) population. Consecutive PD individuals were submitted for simultaneous fiberoptic endoscopic evaluation of swallowing (FEES) and voice recording. Speech therapists rated the presence or absence of wetness and other voice abnormalities. Two binary endpoints of FEES were selected for comparison with an index test: low penetration (LP) and low penetration and/or aspiration (LP/ASP). The accuracy of wet voice changed according to the testing material in PD patients. Overall, the specificity of this indicator was better than its sensitivity, and the wafer cookie and yogurt drink yielded the best indices. Our data show that wet voice is clearly indicative of LP or LP/ASP in PD patients in case of positive test. However, in the case of a negative result, the wet voice test should be repeated or combined with other clinical tests to include or exclude the risk of LP or LP/ASP.

Different Effects of Roughness (Granularity) and Hydrophobicity

NASA Astrophysics Data System (ADS)

Shirtcliffe, Neil; McHale, Glen; Hamlett, Christopher; Newton, Michael

2010-05-01

With thanks to Stefan Doerr and Jorge Mataix-Solera for their invitation Superhydrophobicity is an interesting effect that appears to be simple on the outset; increased surface area from roughness increases interfacial area and therefore energy loss or gain. More extreme roughness prevents total wetting, resulting in gas pockets present at the surface and a drastic change in the properties of the system. Increases in complexity of the system, by adding porosity (granularity), allowing the structures to move, varying the shape of the roughness or the composition of the liquid used often has unexpected effects. Here we will consider a few of these related to complex topography. Overhanging features are commonly used in test samples as they perform better in some tests than simple roughness. It has been shown to be a prerequisite for superoleophobic surfaces as it allows liquids to be suspended for contact angles considerably below 90°. It also allows trapping of gas in lower layers even if the first layer is flooded. This is important in soils as a fixed bed of granules behaves just like a surface with overhanging roughness. Using simple geometry it is possible to predict at what contact angle penetration will occur. Plants have some structured superhydrophobic surfaces and we have shown that some use them in conjunction with other structured surfaces to control water flows. This allows some plants to survive in difficult environments and shows us how subtly different structures interact completely differently with water. Long fibres can either cause water droplets to roll over a plant surface or halt it in its tracks. Implications of this in soils include predicting when particles will adhere more strongly to water drops and why organic fibrous material may play a greater role in the behaviour of water in soils than may be expected from the amount present. The garden snail uses a biosurfactant that is very effective at wetting surfaces and can crawl over most superhydrophobic surfaces. There are some, however, that defeat even the snail's complex slime. Looking at these surfaces in more detail reveals that some superhydrophobic surfaces are much more resistant to the effects of surfactants than others. As mentioned above, overhanging structures, such as those found in granular materials are particularly effective at suspending liquids. This does not, however, always translate to them being more effective against surfactants, unfortunately, however, surfactants are not always as effective as we would like them to be, although drops do not skate across superhydrophobic surfaces they often do not penetrate into them fully either.

Attenuation of iodine 125 radiation with vitreous substitutes in the treatment of uveal melanoma.

PubMed

Oliver, Scott C N; Leu, Min Y; DeMarco, John J; Chow, Philip E; Lee, Steve P; McCannel, Tara A

2010-07-01

To demonstrate attenuation of radiation from iodine 125 ((125)I) to intraocular structures using liquid vitreous substitutes. Four candidate vitreous substitutes were tested for attenuation using empirical measurement and theoretical calculation. In vitro and ex vivo cadaveric dosimetry measurements were obtained with lithium fluoride thermoluminescent dosimeters to demonstrate the attenuation effect of vitreous substitution during (125)I simulated plaque brachytherapy. Theoretical dosimetry calculations were based on Monte Carlo simulation. In a cylindrical phantom at a 17-mm depth, liquid vitreous substitutes as compared with saline showed significant reduction of radiation penetration (48% for 1000-centistoke [cSt] silicone oil [polydimethyl-n-siloxane], 47% for 5000-cSt silicone oil [polydimethyl-n-siloxane], 40% for heavy oil [perfluorohexyloctane/polydimethyl-n-siloxane], and 35% for perfluorocarbon liquid [perfluoro-n-octane]). Human cadaveric ex vivo measurements demonstrated a 1000-cSt silicone oil to saline dose ratio of 35%, 52%, 55%, and 48% at arc lengths of 7.6, 10.6, 22.3, and 28.6 mm from the plaque edge, respectively, along the surface of the globe. Monte Carlo simulation of a human globe projected attenuation as high as 57% using 1000-cSt silicone oil. Intraocular vitreous substitutes including silicone oil, heavy oil, and perfluorocarbon liquid attenuate the radiation dose from (125)I. Cadaveric ex vivo measurements and Monte Carlo simulation both demonstrate radiation attenuation using 1000-cSt silicone oil at distances corresponding to vital ocular structures. Clinical Relevance Attenuation of radiation with silicone oil endotamponade in the treatment of uveal melanoma may significantly reduce radiation-induced injury to vital ocular structures.

Quantitative analysis of liquid penetration kinetics and slaking of aggregates as related to solid-liquid interfacial properties

NASA Astrophysics Data System (ADS)

Goebel, Marc-O.; Woche, Susanne K.; Bachmann, Jörg

2012-06-01

SummaryAggregate stability is frequently shown to be enhanced by strong soil water repellency, however, there is limited systematic evidence on this effect for moderately (subcritically) water repellent soils. This study aimed to investigate the specific effects of interfacial properties on the liquid penetration kinetics in relation to the stability of subcritically water repellent aggregates (4-6.3 mm) from various arable and forest soils against breakdown by slaking. In contrast to many other studies, where aggregate stability was determined by wet sieving, we here assessed the stability by immersion of air-dry aggregates in water-ethanol solutions with surface tensions ranging from 30 to 70 mN m-1. This approach allowed a highly sensitive discrimination of different stability levels and the determination of breakdown kinetics also for less stable aggregates. Interfacial properties were characterized in terms of contact angle measured on crushed aggregates, θc, and calculated for intact aggregates, θi, based on infiltration measurements with water and ethanol. Aggregate stability turned out to be higher in forest soils compared to arable soils with topsoil aggregates generally found to be more stable than subsoil aggregates. For water repellent aggregates, characterized by contact angles >40° and low water infiltration rates (<0.2 mm3 s-0.5), the fraction of disrupted aggregates after 30 s of immersion was generally below 10%, whereas in case of the more wettable aggregates, characterized by contact angles <10° and higher infiltration rates (>0.25 mm3 s-0.5) more than 80% of the aggregates were disrupted. In accordance, we found a close relationship between aggregate stability and wettability with differences between θc and θi being generally small. In addition, aggregate stability turned out to be related to organic carbon content. However, correlation analysis revealed that both persistence of aggregate stability and kinetics of aggregate breakdown were more strongly affected by the contact angle, θc (r = 0.90 and r = -0.83, respectively) and θi (r = 0.89 and r = -0.76, respectively) than the organic carbon content (r = 0.62 and -0.52, respectively), suggesting that stability was primarily controlled by aggregate interfacial properties. Calculation of liquid penetrativity as a function of surface tension and contact angle clearly demonstrated the importance of both solid and liquid interfacial properties in determining the stability of subcritically water repellent aggregates against slaking.

Comprehensive evaluation of formulation factors for ocular penetration of fluoroquinolones in rabbits using cassette dosing technique.

PubMed

Sharma, Charu; Biswas, Nihar R; Ojha, Shreesh; Velpandian, Thirumurthy

2016-01-01

Corneal permeability of drugs is an important factor used to assess the efficacy of topical preparations. Transcorneal penetration of drugs from aqueous formulation is governed by various physiological, physiochemical, and formulation factors. In the present study, we investigated the effect of formulation factors like concentration, pH, and volume of instillation across the cornea using cassette dosing technique for ophthalmic fluoroquinolones (FQs). Sterile cocktail formulations were prepared using four congeneric ophthalmic FQs (ofloxacin, sparfloxacin, pefloxacin mesylate, and gatifloxacin) at concentrations of 0.025%, 0.5%, and 0.1%. Each formulation was adjusted to different pH ranges (4.5, 7.0, and 8.0) and assessed for transcorneal penetration in vivo in rabbit's cornea (n=4 eyes) at three different volumes (12.5, 25, and 50 μL). Aqueous humor was aspirated through paracentesis after applying local anesthesia at 0, 5, 15, 30, 60, 120, and 240 minutes postdosing. The biosamples collected from a total of 27 groups were analyzed using liquid chromatography-tandem mass spectroscopy to determine transcorneal permeability of all four FQs individually. Increase in concentration showed an increase in penetration up to 0.05%; thereafter, the effect of concentration was found to be dependent on volume of instillation as we observed a decrease in transcorneal penetration. The highest transcorneal penetration of all FQs was observed at pH 7.0 at concentration 0.05% followed by 0.025% at pH 4.5. Lastly, increasing the volume of instillation from 12.5 to 50 μL showed a significant fall in transcorneal penetration. The study concludes that formulation factors showed discernible effect on transcorneal permeation; therefore, due emphasis should be given on drug development and design of ophthalmic formulation.

Development of a constant surface pressure penetration langmuir balance based on axisymmetric drop shape analysis.

PubMed

Wege, H A; Holgado-Terriza, J A; Cabrerizo-Vílchez, M A

2002-05-15

A new constant pressure pendant-drop penetration surface balance has been developed combining a pendant-drop surface balance, a rapid-subphase-exchange technique, and a fuzzy logic control algorithm. Beside the determination of insoluble monolayer compression-expansion isotherms, it allows performance of noninvasive kinetic studies of the adsorption of surfactants added to the new subphase onto the free surface and of the adsorption/penetration/reaction of the former onto/into/with surface layers, respectively. The interfacial pressure pi is a fundamental parameter in these studies: by working at constant pi one controls the height of the energy barrier to adsorption/penetration and can select different regimes and steps of the adsorption/penetration process. In our device a solution drop is formed at the tip of a coaxial double capillary, connected to a double microinjector. Drop profiles are extracted from digital drop micrographs and fitted to the equation of capillarity, yielding pi, the drop volume V, and the interfacial area A. pi is varied changing V (and hence A) with the microinjector. Control is based on a case-adaptable modulated fuzzy-logic PID algorithm able to maintain constant pi (or A) under a wide range of experimental conditions. The drop subphase liquid can be exchanged quantitatively by the coaxial capillaries. The adsorption/penetration/reaction kinetics at constant pi are then studied monitoring A(t), i.e., determining the relative area change necessary at each instant to compensate the pressure variation due to the interaction of the surfactant in the subsurface with the surface layer. A fully Windows-integrated program manages the whole setup. Examples of experimental protein adsorption and monolayer penetration kinetics are presented.

Confocal Raman microscopy and multivariate statistical analysis for determination of different penetration abilities of caffeine and propylene glycol applied simultaneously in a mixture on porcine skin ex vivo.

PubMed

Mujica Ascencio, Saul; Choe, ChunSik; Meinke, Martina C; Müller, Rainer H; Maksimov, George V; Wigger-Alberti, Walter; Lademann, Juergen; Darvin, Maxim E

2016-07-01

Propylene glycol is one of the known substances added in cosmetic formulations as a penetration enhancer. Recently, nanocrystals have been employed also to increase the skin penetration of active components. Caffeine is a component with many applications and its penetration into the epidermis is controversially discussed in the literature. In the present study, the penetration ability of two components - caffeine nanocrystals and propylene glycol, applied topically on porcine ear skin in the form of a gel, was investigated ex vivo using two confocal Raman microscopes operated at different excitation wavelengths (785nm and 633nm). Several depth profiles were acquired in the fingerprint region and different spectral ranges, i.e., 526-600cm(-1) and 810-880cm(-1) were chosen for independent analysis of caffeine and propylene glycol penetration into the skin, respectively. Multivariate statistical methods such as principal component analysis (PCA) and linear discriminant analysis (LDA) combined with Student's t-test were employed to calculate the maximum penetration depths of each substance (caffeine and propylene glycol). The results show that propylene glycol penetrates significantly deeper than caffeine (20.7-22.0μm versus 12.3-13.0μm) without any penetration enhancement effect on caffeine. The results confirm that different substances, even if applied onto the skin as a mixture, can penetrate differently. The penetration depths of caffeine and propylene glycol obtained using two different confocal Raman microscopes are comparable showing that both types of microscopes are well suited for such investigations and that multivariate statistical PCA-LDA methods combined with Student's t-test are very useful for analyzing the penetration of different substances into the skin. Copyright © 2016 Elsevier B.V. All rights reserved.

Mars penetrator umbilical. [to study geophysical properties of Mars

NASA Technical Reports Server (NTRS)

Barns, C. E.

1979-01-01

The device proposed to gather subsurface data on the planet Mars is a ballistic probe which penetrates the soil after a free fall through the Martian atmosphere. Highlights of the design, development, and testing of several features of the Mars Surface Penetration Probe are outlined.

Technical Capability Upgrades to the NASA Langley Research Center 8 ft. by 15 ft. Thermal Vacuum Chamber

NASA Technical Reports Server (NTRS)

Thornblom, Mark N.; Beverly, Joshua; O'Connell, Joseph J.; Duncan, Dwight L.

2016-01-01

The 8 ft. by 15 ft. thermal vacuum chamber (TVAC), housed in Building 1250 at the NASA Langley Research Center (LaRC), and managed by the Systems Integration and Test Branch within the Engineering Directorate, has undergone several significant modifications to increase testing capability, safety, and quality of measurements of articles under environmental test. Significant modifications include: a new nitrogen distribution manifold for supplying the shroud and other cold surfaces to liquid nitrogen temperatures; a new power supply and distribution system for accurately controlling a quartz IR lamp suite; a suite of contamination monitoring sensors for outgassing measurements and species identification; a new test article support system; signal and power feed-throughs; elimination of unnecessary penetrations; and a new data acquisition and control commanding system including safety interlocks. This paper will provide a general overview of the LaRC 8 ft. by 15 ft. TVAC chamber, an overview of the new technical capabilities, and will illustrate each upgrade in detail, in terms of mechanical design and predicted performance. Additionally, an overview of the scope of tests currently being performed in the chamber will be documented, and sensor plots from tests will be provided to show chamber temperature and pressure performance with actual flight hardware under test.

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.

Epiphany sealer penetration into dentinal tubules: Confocal laser scanning microscopic study.

PubMed

Ravi, S V; Nageswar, Rao; Swapna, Honwad; Sreekant, Puthalath; Ranjith, Madhavan; Mahidhar, Surabhi

2014-03-01

The aim of the following study was to evaluate the percentage and average depth of epiphany sealer penetration into dentinal tubules among the coronal, middle and apical thirds of the root using the confocal laser scanning microscopy (CLSM). A total of 10 maxillary central incisors were prepared and obturated with Resilon-Epiphany system. Sealer was mixed with fluorescent rhodamine B isothiyocyanate dye for visibility under confocal microscope. Teeth were cross-sectioned into coronal, middle and apical sections-2 mm thick. Sections were observed under CLSM. Images were analyzed for percentage and average depth of sealer penetration into dentinal tubules using the lasso tool in Adobe Photoshop CS3 (Adobe systems incorporated, San jose, CA) and laser scanning microscopy (LSM 5) image analyzer. One-way analysis of variance with Student Neuman Keuls post hoc tests, Kruskal-Wallis test and Wilcoxon signed-rank post hoc tests. The results showed that a higher percentage of sealer penetration in coronal section-89.23%, followed by middle section-84.19% and the apical section-64.9%. Average depth of sealer penetration for coronal section was 526.02 μm, middle-385.26 μm and apical-193.49 μm. Study concluded that there was higher epiphany sealer penetration seen in coronal followed by middle and least at apical third of the roots.

Cyclic mechanical loading promotes bacterial penetration along composite restoration marginal gaps

PubMed Central

Khvostenko, D.; Salehi, S.; Naleway, S. E.; Hilton, T. J.; Ferracane, J. L.; Mitchell, J. C.; Kruzic, J. J.

2015-01-01

Objectives Secondary caries is the most common reason for composite restoration replacement and usually forms between dentin and the filling. The objective of this study was to investigate the combined effect of cyclic loading and bacterial exposure on bacterial penetration into gaps at the interface between dentin and resin composite restorative material using a novel bioreactor system and test specimen design. Methods Human molars were machined into 3 mm thick disks with 2 mm deep × 5 mm diameter cavity preparations into which composite restorations were placed. A ∼15-30 micrometer (small) or ∼300 micrometer wide (large) dentin-restoration gap was introduced along half of the interface between the dentin and restoration. Streptococcus mutans UA 159 biofilms were grown on each sample prior to testing in a bioreactor both with and without cyclic loading. Both groups of samples were tested for 2 weeks and post-test biofilm viability was confirmed with a live-dead assay. Samples were fixed, mounted and cross-sectioned to reveal the gaps and observe the depth of bacterial penetration. Results It was shown that for large gap samples the bacteria easily penetrated to the full depth of the gap independent of loading or non-loading conditions. The results for all cyclically loaded small gap samples show a consistently deep bacterial penetration down 100% of the gap while the average penetration depth was only 67% for the non-loaded samples with only two of six samples reaching 100%. Significance A new bioreactor was developed that allows combining cyclic mechanical loading and bacterial exposure of restored teeth for bacterial biofilm and demineralization studies. Cyclic loading was shown to aid bacterial penetration into narrow marginal gaps, which could ultimately promote secondary caries formation. PMID:25900624

A comparison of observed and analytically derived remote sensing penetration depths for turbid water

NASA Technical Reports Server (NTRS)

Morris, W. D.; Usry, J. W.; Witte, W. G.; Whitlock, C. H.; Guraus, E. A.

1981-01-01

The depth to which sunlight will penetrate in turbid waters was investigated. The tests were conducted in water with a single scattering albedo range, and over a range of solar elevation angles. Two different techniques were used to determine the depth of light penetration. It showed little change in the depth of sunlight penetration with changing solar elevation angle. A comparison of the penetration depths indicates that the best agreement between the two methods was achieved when the quasisingle scattering relationship was not corrected for solar angle. It is concluded that sunlight penetration is dependent on inherent water properties only.

Combustion synthesis of ceramic-metal composite materials - The TiC-Al2O3-Al system

NASA Technical Reports Server (NTRS)

Feng, H. J.; Moore, John J.; Wirth, D. G.

1992-01-01

Combustion synthesis was applied for producing ceramic-metal composites with reduced levels of porosity, by allowing an excess amount of liquid metal, generated by the exothermic reaction during synthesis, to infiltrate the pores. It is shown that this method, when applied to TiC-Al2O3 system, led to a decreased level of porosity in the resulting TiC-Al2O3-Al product, as compared with that of TiC-Al2O3 system. This in situ procedure is more efficient than the two-stage conventional processes (i.e., sintering followed by liquid metal infiltration), although there are limitations with respect to total penetration of the liquid metal and maintaining a stable propagation of the combustion reaction.

Exobiological Exploration of Europa (E3) Europa Lander

NASA Technical Reports Server (NTRS)

Stillwagen, F. H.; Manvi, Ramachandra; Seywald, Hans; Park, Sang-Young; Kolacinski, Rick

2002-01-01

The search for life outside Earth's protected atmosphere is a compelling testament to the quest by mankind to determine if "we" are alone in the universe. The phenomenal success of the NASA Galileo spacecraft has indicated that the moons of Jupiter, and most notably Europa, may indeed contain subsurface liquid under an icy surface. This speculation of a salty liquid subsurface fuels expert opinions that biological products may exist. The Revolutionary Aerospace Systems Concepts (RASC) effort at Langley Research Center, initiated by NASA Headquarters, pushes NASA and the Aerospace/Science community to target advanced evolutionary technology usage to provide a Europa Lander concept targeted for completion within the next 50 years. The study effort indicates the use of certain advanced technologies to achieve a subsurface penetrator and liquid explorer in the approximately 2040 timeframe.

Influence of granulometry in the Hurst exponent of air liquid interfaces formed during capillary rising in a granular media

NASA Astrophysics Data System (ADS)

Gontijo, Guilherme L.; Souza, Flávia B.; Braga, Rafael M. L.; Silva, Pedro H. E.; Correia, Maury D.; Atman, A. P. F.

2017-06-01

We report results concerning the fractal dimension of a air/fluid interface formed during the capillary rising of a fluid into a dense granular media. The system consists in a modified Hele-Shaw cell filled with grains at different granulometries and confined in a narrow gap between the glass plates. The system is then placed onto a water reservoir, and the liquid penetrates the medium due to capillary forces. We measure the Hurst exponent of the liquid/air interface with help of image processing, and follow the temporal evolution of the profiles. We observe that the Hurst exponent can be related with the granulometry, but the range of values are odd to the predicted values from models or theory.

Heating of a fully saturated darcian half-space: Pressure generation, fluid expulsion, and phase change

USGS Publications Warehouse

Delaney, P.

1984-01-01

Analytical solutions are developed for the pressurization, expansion, and flow of one- and two-phase liquids during heating of fully saturated and hydraulically open Darcian half-spaces subjected to a step rise in temperature at its surface. For silicate materials, advective transfer is commonly unimportant in the liquid region; this is not always the case in the vapor region. Volume change is commonly more important than heat of vaporization in determining the position of the liquid-vapor interface, assuring that the temperatures cannot be determined independently of pressures. Pressure increases reach a maximum near the leading edge of the thermal front and penetrate well into the isothermal region of the body. Mass flux is insensitive to the hydraulic properties of the half-space. ?? 1984.

Investigation of the impact of high liquid viscosity on jet atomization in crossflow via high-fidelity simulations

NASA Astrophysics Data System (ADS)

Li, Xiaoyi; Gao, Hui; Soteriou, Marios C.

2017-08-01

Atomization of extremely high viscosity liquid can be of interest for many applications in aerospace, automotive, pharmaceutical, and food industries. While detailed atomization measurements usually face grand challenges, high-fidelity numerical simulations offer the advantage to comprehensively explore the atomization details. In this work, a previously validated high-fidelity first-principle simulation code HiMIST is utilized to simulate high-viscosity liquid jet atomization in crossflow. The code is used to perform a parametric study of the atomization process in a wide range of Ohnesorge numbers (Oh = 0.004-2) and Weber numbers (We = 10-160). Direct comparisons between the present study and previously published low-viscosity jet in crossflow results are performed. The effects of viscous damping and slowing on jet penetration, liquid surface instabilities, ligament formation/breakup, and subsequent droplet formation are investigated. Complex variations in near-field and far-field jet penetrations with increasing Oh at different We are observed and linked with the underlying jet deformation and breakup physics. Transition in breakup regimes and increase in droplet size with increasing Oh are observed, mostly consistent with the literature reports. The detailed simulations elucidate a distinctive edge-ligament-breakup dominated process with long surviving ligaments for the higher Oh cases, as opposed to a two-stage edge-stripping/column-fracture process for the lower Oh counterparts. The trend of decreasing column deflection with increasing We is reversed as Oh increases. A predominantly unimodal droplet size distribution is predicted at higher Oh, in contrast to the bimodal distribution at lower Oh. It has been found that both Rayleigh-Taylor and Kelvin-Helmholtz linear stability theories cannot be easily applied to interpret the distinct edge breakup process and further study of the underlying physics is needed.

An efficient approach to imaging underground hydraulic networks

NASA Astrophysics Data System (ADS)

Kumar, Mohi

2012-07-01

To better locate natural resources, treat pollution, and monitor underground networks associated with geothermal plants, nuclear waste repositories, and carbon dioxide sequestration sites, scientists need to be able to accurately characterize and image fluid seepage pathways below ground. With these images, scientists can gain knowledge of soil moisture content, the porosity of geologic formations, concentrations and locations of dissolved pollutants, and the locations of oil fields or buried liquid contaminants. Creating images of the unknown hydraulic environments underfoot is a difficult task that has typically relied on broad extrapolations from characteristics and tests of rock units penetrated by sparsely positioned boreholes. Such methods, however, cannot identify small-scale features and are very expensive to reproduce over a broad area. Further, the techniques through which information is extrapolated rely on clunky and mathematically complex statistical approaches requiring large amounts of computational power.

Atomization of liquids in a Pease-Anthony Venturi scrubber. Part II. Droplet dispersion.

PubMed

Gonçalves, J A S; Costa, M A M; Aguiar, M L; Coury, J R

2004-12-10

Droplet distribution is of fundamental importance to the performance of a Venturi scrubber. Ensuring good liquid distribution can increase performance at minimal liquid usage. In this study, droplet dispersion in a rectangular Pease-Anthony Venturi scrubber, operating horizontally, was examined both theoretically and experimentally. The Venturi throat cross-section was 24 mm x 35 mm, and the throat length varied from 63 to 140 mm. Liquid was injected through a single orifice (1.0 mm diameter) on the throat wall. This arrangement allowed the study of the influence of jet penetration on droplet distribution. Gas velocity at the throat was 58.3 and 74.6 m/s, and the liquid flow rate was 286, 559 and 853 ml/min. A probe with a 2.7 mm internal diameter was used to isokinetically remove liquid from several positions inside the equipment. It was possible to study liquid distribution close to the injection point. A new model for droplet dispersion, which incorporates the new description of the jet atomization process developed by the present authors in the first article of this series, is proposed and evaluated. The model predicted well the experimental data.

Interfacial Dynamics of Condensing Vapor Bubbles in an Ultrasonic Acoustic Field

NASA Astrophysics Data System (ADS)

Boziuk, Thomas; Smith, Marc; Glezer, Ari

2016-11-01

Enhancement of vapor condensation in quiescent subcooled liquid using ultrasonic actuation is investigated experimentally. The vapor bubbles are formed by direct injection from a pressurized steam reservoir through nozzles of varying characteristic diameters, and are advected within an acoustic field of programmable intensity. While kHz-range acoustic actuation typically couples to capillary instability of the vapor-liquid interface, ultrasonic (MHz-range) actuation leads to the formation of a liquid spout that penetrates into the vapor bubble and significantly increases its surface area and therefore condensation rate. Focusing of the ultrasonic beam along the spout leads to ejection of small-scale droplets from that are propelled towards the vapor liquid interface and result in localized acceleration of the condensation. High-speed video of Schlieren images is used to investigate the effects of the ultrasonic actuation on the thermal boundary layer on the liquid side of the vapor-liquid interface and its effect on the condensation rate, and the liquid motion during condensation is investigated using high-magnification PIV measurements. High-speed image processing is used to assess the effect of the actuation on the dynamics and temporal variation in characteristic scale (and condensation rate) of the vapor bubbles.

Subsurface investigation with ground penetrating radar

USDA-ARS?s Scientific Manuscript database

Ground penetrating radar (GPR) data was collected on a small test plot at the OTF/OSU Turfgrass Research & Education Facility in Columbus, Ohio. This test plot was built to USGA standards for a golf course green, with a constructed sand layer just beneath the surface overlying a gravel layer, that i...

Effect of moisture content and dry unit weight on the resilient modulus of subgrade soils predicted by cone penetration test.

DOT National Transportation Integrated Search

2002-06-01

The objective of this study was to investigate the effect of moisture content and dry unit weight on the resilient characteristics of subgrade soil predicted by the cone penetration test. An experimental program was conducted in which cone penetratio...

Quality of Pinzgau bull spermatozoa following different periods of cryostorage.

PubMed

Chrenek, P; Spaleková, E; Olexikova, L; Makarevich, A; Kubovicova, E

2017-04-01

The aim of this work was to examine the influence of cryostorage duration of Pinzgau bull's insemination doses (IDs) on some sperm traits. The IDs were frozen by a slow freezing method and stored in liquid nitrogen for different periods: less than 8 years (group 1), 8-13 years (group 2) and 14-18 years (group 3). Motility (CASA), pathological sperm rate (Giemsa staining), apoptotic (Yo-Pro-1-positive) and necrotic (propidium iodide-positive) cell occurrence and fertilizing ability (penetration/fertilization test) of spermatozoa were evaluated post-thaw. The average post-thaw sperm motility in all examined groups was over 40%. No significant influence of storage length either on the sperm total motility or progressive movement was revealed. In each tested group the average rate of malformed spermatozoa did not exceed 20%. No effect of cryostorage length on the occurrence of apoptotic or necrotic sperm was noted. Similarly, penetrating/fertilizing ability of sperm did not differ among the groups, excepting differences in the rate of pronuclei (PN) formation. In group 1, 72.9% of eggs showed two visible PN following 20 h incubation with sperm, whilst in groups 2 and 3 only 67 and 54.5% of zygotes, respectively, had both PN at this time. These results revealed no influence of storage time on the bull spermatozoa in all parameters excepting the rate of PN formation. As high inter-male variability was observed in the susceptibility of bull sperm to cryostorage, individual differences should be taken into account when semen from individual bulls is to be stored for a long time.

The Solid Phase Curing Time Effect of Asbuton with Texapon Emulsifier at the Optimum Bitumen Content

NASA Astrophysics Data System (ADS)

Sarwono, D.; Surya D, R.; Setyawan, A.; Djumari

2017-07-01

Buton asphalt (asbuton) could not be utilized optimally in Indonesia. Asbuton utilization rate was still low because the processed product of asbuton still have impracticable form in the term of use and also requiring high processing costs. This research aimed to obtain asphalt products from asbuton practical for be used through the extraction process and not requiring expensive processing cost. This research was done with experimental method in laboratory. The composition of emulsify asbuton were 5/20 grain, premium, texapon, HCl, and aquades. Solid phase was the mixture asbuton 5/20 grain and premium with 3 minutes mixing time. Liquid phase consisted texapon, HCl and aquades. The aging process was done after solid phase mixing process in order to reaction and tie of solid phase mixed become more optimal for high solubility level of asphalt production. Aging variable time were 30, 60, 90, 120, and 150 minutes. Solid and liquid phase was mixed for emulsify asbuton production, then extracted for 25 minutes. Solubility level of asphalt, water level, and asphalt characteristic was tested at extraction result of emulsify asbuton with most optimum ashphal level. The result of analysis tested data asphalt solubility level at extract asbuton resulted 94.77% on 120 minutes aging variable time. Water level test resulted water content reduction on emulsify asbuton more long time on occurring of aging solid phase. Examination of asphalt characteristic at extraction result of emulsify asbuton with optimum asphalt solubility level, obtain specimen that have rigid and strong texture in order that examination result have not sufficient ductility and penetration value.

Ammunition for Law Enforcements. Part I. Methodology for Evaluating Relative Stopping Power and Results

DTIC Science & Technology

1979-10-01

expansion, relative stopping power according to one or another formula or test method, penetration, ricochet, and other fragments. In the past, the solution...the data gathered for each test round, in the following documents: a. "Ammunition For Law Enforcement: Part II, Data Obtained for Bullets Penetrating...high velocity testing , chamber pressures exceeded those permissible in standard handguns. For safety, then, Mann test barrels were used. At this point

The Potential of Sonic IR to Inspect Aircraft Components Traditionally Inspected with Fluorescent Penetrant and or Magnetic Particle Inspection

NASA Astrophysics Data System (ADS)

DiMambro, J.; Ashbaugh, D. M.; Han, X.; Favro, L. D.; Lu, J.; Zeng, Z.; Li, W.; Newaz, G. M.; Thomas, R. L.

2006-03-01

Sandia National Laboratories Airworthiness Assurance Nondestructive Inspection Validation Center (AANC) provides independent and quantitative evaluations of new and enhanced inspection, to developers, users, and regulators of aircraft. Wayne State University (WSU) has developed and patented an inspection technique using high-power ultrasonic excitation and infrared technology to detect defects in a variety of materials. AANC and WSU are working together as part of the FAA Sonic Infrared Technology Transfer Program. The ultimate goal of the program is to implement Sonic IR in the aviation field where appropriate. The capability of Sonic IR imaging to detect cracks in components commonly inspected with magnetic particle or liquid penetrant inspection in the field is of interest to industry.

Investigation of the interaction between liquid and micro/nanostructured surfaces during condensation with quartz crystal microbalance

NASA Astrophysics Data System (ADS)

Su, Junwei

Dropwise condensation (DWC) on hydrophobic surfaces is attracting attention for its great potential in many industrial applications, such as steam power plants, water desalination, and de-icing of aerodynamic surfaces, to list a few. The direct dynamic characterization of liquid/solid interaction can significantly accelerate the progress toward a full understanding of the thermal and mass transport mechanisms during DWC processes. The research focuses on the development of a novel acoustic-based technique for analyzing the liquid/solid interactions of different condensations on micro- and nanostructured surfaces including DWC. hi addition. the newly developed technology was demonstrated for quantitatively sensing different wetting states of liquid on rough surfaces. First, different micro/nanostructures were fabricated on the quartz crystal microbalance (QCM), which serves as acoustic sensor. Polymethyl methacrylate (PMMA) micropillars, with varying heights from 6.03 to 25.02 microm, were fabricated on a quartz crystal microbalance (QCM) substrate by thermal nanoimprinting lithography to form pillar-based QCM (QCM-P). For nanostructured QCM. a copper layer was deposited on the QCM surface and then nanostructures of copper oxide (CuO) films were formed via chemical oxidation in an alkaline solution. Then, these surfaces were treated to make them superhydrophilic or superhydrophobic using oxygen plasma treatment or with coating of 1H,1 H,2H,2H-perfluorooctyl-trichlorosilane (PFOTS). Based on the geometry of these micro/nanostructures, the relationship between the frequency responses of QCM and the wetting states of these surfaces was theoretically investigated. Different theoretical models were established to describing the frequency shift of the micro- and nanostructured QCM in different wetting states. For the microstructured surface, the cantilever based model and a two-degree-of-freedom dynamic model were applied to predict the frequency shift of the QCM-P in different wetting states, by taking advantage of the well-defined micropillar structures. For the nanostructured surface, the gravimetric term was applied for the penetrated liquid as it moves synchronously with the oscillating crystal surface. It was revealed that the penetrated wetting state (Wenzel state) causes one order of magnitude higher frequency shift of the QCM than the suspended state (Cassie state) does. For the suspended state, the equivalent liquid mass on the tips of the roughness dominates the frequency shift signal instead of the damping. A nonlinear relationship appears between the frequency shift and micropillar height for both Cassie and Wenzel wetting states, due to the vibration phase veering at the "critical height". This implied that a significant improvement of sensitivity of QCM-P over traditional QCM occurred in the suspended state, as well as in the penetrated state. Besides, the suspended state provides a much higher quality factor than penetrated state. Using the insights gained from the experimental results and modeling results, the frequency shift of the QCM was normalized to reveal the wetting state directly. Then. the QCM device together with the microscopic observation was used to probe the droplets' growth and their coalescence processes. The normalized frequency shifts of QCM devices are clearly linked to the different condensation states at a global level, which cannot be characterized by other techniques such as E-SEM and TEM. The characterization of the trapped liquid in micro/nanostructures, which is very challenging for microscopic observation, can be easily carried out by this acoustic technique. These results quantitatively demonstrated the different condensation states. In addition, the transition between the Cassie and the Wenzel states was successfully captured by this method. The newly developed QCM system provides a valuable tool for the dynamic characterization of different condensation processes.

Differential permeation of artemia cysts and cucumber seeds by alcohols

NASA Technical Reports Server (NTRS)

Smith, C. W.; Siegel, S. M.

1975-01-01

The rate of penetration of the simpler alcohols into brine shrimp cysts and cucumber seeds was studied. In solutions below 70% the rate of penetration is related to lipid solvent capacity of the alcohol. In concentrations above 70%, particularly in absolute alcohols, methanol penetrates brine shrimp rapidly and ethanol penetrates slowly. All the other alcohols tested did not penetrate the dormant structures. Ethionine and deuteroxy-methanol did not affect the rate of penetration of methanol. It is suggested that in dehydrated membranes the lipid moiety is protected by a continuous sheet of protein. Methanol, which is fairly similar to water, is probably able to penetrate the membrane by initiating a conformation change in the protein, exposing the lipid which subsequently dissolves in the methanol thus destroying the membrane.

Influence of wood-derived biochar on the compactibility and strength of silt loam soil

NASA Astrophysics Data System (ADS)

Ahmed, Ahmed; Gariepy, Yvan; Raghavan, Vijaya

2017-04-01

Biochar is proven to enhance soil fertility and increase crop productivity. Given that the influence of biochar on soil compaction remains unclear, selected physico-mechanical properties of soil amended with wood-derived biochar were assessed. For unamended silt loam, the bulk density, maximum bulk density, optimum moisture content, plastic limit, liquid limit, and plasticity index were 1.05 Mg m-3, 1.69 Mg m-3, 16.55, 17.1, 29.3, and 12.2%, respectively. The penetration resistance and shear strength of the unamended silt loam compacted in the standard compaction Proctor mold and at its optimum moisture content were 1800 kPa and 850 kPa, respectively. Results from amending the silt loam with 10% particle size ranges (0.5-212 μm) led to relative decreases of 18.1, 17.75, 66.66, and 97.4% in bulk density, maximum bulk density, penetration resistance, and shear strength, respectively; a 26.8% relative increase in optimum moisture content; along with absolute increases in plastic limit, liquid limit, and plasticity index of 5.3, 13.7, and 8.4%, respectively. While the biochar-amended silt loam soil was more susceptible to compaction, however, soil mechanical impedance enhanced.

Shock-induced bubble jetting into a viscous fluid with application to tissue injury in shock-wave lithotripsy.

PubMed

Freund, J B; Shukla, R K; Evan, A P

2009-11-01

Shock waves in liquids are known to cause spherical gas bubbles to rapidly collapse and form strong re-entrant jets in the direction of the propagating shock. The interaction of these jets with an adjacent viscous liquid is investigated using finite-volume simulation methods. This configuration serves as a model for tissue injury during shock-wave lithotripsy, a medical procedure to remove kidney stones. In this case, the viscous fluid provides a crude model for the tissue. It is found that for viscosities comparable to what might be expected in tissue, the jet that forms upon collapse of a small bubble fails to penetrate deeply into the viscous fluid "tissue." A simple model reproduces the penetration distance versus viscosity observed in the simulations and leads to a phenomenological model for the spreading of injury with multiple shocks. For a reasonable selection of a single efficiency parameter, this model is able to reproduce in vivo observations of an apparent 1000-shock threshold before wide-spread tissue injury occurs in targeted kidneys and the approximate extent of this injury after a typical clinical dose of 2000 shock waves.

Shock-induced bubble jetting into a viscous fluid with application to tissue injury in shock-wave lithotripsy

PubMed Central

Freund, J. B.; Shukla, R. K.; Evan, A. P.

2009-01-01

Shock waves in liquids are known to cause spherical gas bubbles to rapidly collapse and form strong re-entrant jets in the direction of the propagating shock. The interaction of these jets with an adjacent viscous liquid is investigated using finite-volume simulation methods. This configuration serves as a model for tissue injury during shock-wave lithotripsy, a medical procedure to remove kidney stones. In this case, the viscous fluid provides a crude model for the tissue. It is found that for viscosities comparable to what might be expected in tissue, the jet that forms upon collapse of a small bubble fails to penetrate deeply into the viscous fluid “tissue.” A simple model reproduces the penetration distance versus viscosity observed in the simulations and leads to a phenomenological model for the spreading of injury with multiple shocks. For a reasonable selection of a single efficiency parameter, this model is able to reproduce in vivo observations of an apparent 1000-shock threshold before wide-spread tissue injury occurs in targeted kidneys and the approximate extent of this injury after a typical clinical dose of 2000 shock waves. PMID:19894850

Integrated environmental monitoring and simulation system for use as a management decision support tool in urban areas.

PubMed

Fatta, D; Naoum, D; Loizidou, M

2002-04-01

Leachates are generated as a result of water or other liquid passing through waste at a landfill site. These contaminated liquids originate from a number of sources, including the water produced during the decomposition of the waste as well as rain-fall which penetrates the waste and dissolves the material with which it comes into contact. The penetration of the rain-water depends on the nature of the landfill (e.g. surface characteristics, type and quantity of vegetation, gradient of layers, etc). The uncontrolled infiltration of leachate into the vadose (unsaturated) zone and finally into the saturated zone (groundwater) is considered to be the most serious environmental impact of a landfill. In the present paper the water flow and the pollutant transport characteristics of the Ano Liosia Landfill site in Athens (Greece) were simulated by creating a model of groundwater flows and contaminant transport. A methodology for the model is presented. The model was then integrated into the Ecosim system which is a prototype funded by the EU, (Directorate General XIII: Telematics and Environment). This is an integrated environmental monitoring and modeling system, which supports the management of environmental planning in urban areas.

Numerical modeling of ultrasonic cavitation in ionic liquids

NASA Astrophysics Data System (ADS)

Calvisi, Michael L.; Elder, Ross M.

2017-11-01

Ionic liquids have favorable properties for sonochemistry applications in which the high temperatures and pressures achieved by cavitation bubbles are important drivers of chemical processes. Two different numerical models are presented to simulate ultrasonic cavitation in ionic liquids, each with different capabilities and physical assumptions. A model based on a compressible form of the Rayleigh-Plesset equation (RPE) simulates ultrasonic cavitation of a spherical bubble with a homogeneous interior, incorporating evaporation and condensation at the bubble surface, and temperature-varying thermodynamic properties in the interior. A second, more computationally intensive model of a spherical bubble uses the finite element method (FEM) and accounts for spatial variations in pressure and temperature throughout the flow domain. This model provides insight into heat transfer across the bubble surface and throughout the bubble interior and exterior. Parametric studies are presented for sonochemistry applications involving ionic liquids as a solvent, examining a range of realistic ionic liquid properties and initial conditions to determine their effect on temperature and pressure. Results from the two models are presented for parametric variations including viscosity, thermal conductivity, water content of the ionic liquid solvent, acoustic frequency, and initial bubble pressure. An additional study performed with the FEM model examines thermal penetration into the surrounding ionic liquid during bubble oscillation. The results suggest the prospect of tuning ionic liquid properties for specific applications.

Wellbore pressure transducer

DOEpatents

Shuck, Lowell Z.

1979-01-01

Subterranean earth formations containing energy values are subjected to hydraulic fracturing procedures to enhance the recovery of the energy values. These fractures are induced in the earth formation by pumping liquid into the wellbore penetrating the earth formation until the pressure of the liquid is sufficient to fracture the earth formation adjacent to the wellbore. The present invention is directed to a transducer which is positionable within the wellbore to generate a signal indicative of the fracture initiation useful for providing a timing signal to equipment for seismic mapping of the fracture as it occurs and for providing a measurement of the pressure at which the fracture is initiated.

Containment penetration elastomer seal leak rate tests

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

Bridges, T.L.

1987-07-01

Tests were performed on three elastomer seal designs commonly used for nuclear plant containment mechanical penetrations. The objective of this research project is to obtain an understanding of the integrity and leakage behavior of these seal designs under severe accident temperature and pressure conditions. The three designs tested and the seal materials used in the tests were: (1) double tongue-and-groove design with silicone rubber seals, (2) double-O-ring design with neoprene and ethylene-propylene (EPDM) seals, and (3) double gumdrop design with neoprene and EPDM seals. The effects of thermal aging and angular rotations of flange mating surfaces were determined. The testmore » results provide information required to characterize the leakage behavior of penetrations under severe accident conditions. 3 refs., 10 figs., 12 tabs.« less

Double-Plate Penetration Equations

NASA Technical Reports Server (NTRS)

Hayashida, K. B.; Robinson, J. H.

2000-01-01

This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

Continuous Monitoring of Pin Tip Wear and Penetration into Rock Surface Using a New Cerchar Abrasivity Testing Device

NASA Astrophysics Data System (ADS)

Hamzaban, Mohammad-Taghi; Memarian, Hossein; Rostami, Jamal

2014-03-01

Evaluation of rock abrasivity is important when utilizing mechanized excavation in various mining and civil projects in hard rock. This is due to the need for proper selection of the rock cutting tools, estimation of the tool wear, machine downtime for cutter change, and costs. The Cerchar Abrasion Index (CAI) test is one of the simplest and most widely used methods for evaluating rock abrasivity. In this study, a new device for the determination of frictional forces and depth of pin penetration into the rock surface during a Cerchar test is discussed. The measured parameters were used to develop an analytical model for calculation of the size of the wear flat (and hence a continuous measure of CAI as the pin moves over the sample) and pin tip penetration into the rock during the test. Based on this model, continuous curves of CAI changes and pin tip penetration into the rock were plotted. Results of the model were used for introduction of a new parameter describing rock-pin interaction and classification of rock abrasion.

A new analytical solution solved by triple series equations method for constant-head tests in confined aquifers

NASA Astrophysics Data System (ADS)

Chang, Ya-Chi; Yeh, Hund-Der

2010-06-01

The constant-head pumping tests are usually employed to determine the aquifer parameters and they can be performed in fully or partially penetrating wells. Generally, the Dirichlet condition is prescribed along the well screen and the Neumann type no-flow condition is specified over the unscreened part of the test well. The mathematical model describing the aquifer response to a constant-head test performed in a fully penetrating well can be easily solved by the conventional integral transform technique under the uniform Dirichlet-type condition along the rim of wellbore. However, the boundary condition for a test well with partial penetration should be considered as a mixed-type condition. This mixed boundary value problem in a confined aquifer system of infinite radial extent and finite vertical extent is solved by the Laplace and finite Fourier transforms in conjunction with the triple series equations method. This approach provides analytical results for the drawdown in a partially penetrating well for arbitrary location of the well screen in a finite thickness aquifer. The semi-analytical solutions are particularly useful for the practical applications from the computational point of view.

High velocity penetration into fibre-reinforced concrete materials - protection of buildings

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

Anderson, W.F.; Watson, A.J.; Armstrong, P.J.

1983-05-01

Fibre reinforced concrete suitable for spraying onto existing structures is being examined to assess its resistance to penetration by 7.62mm diameter armour piercing projectiles. A major test programme is being carried out to examine the influence of aggregate type and fibre type. For each aggregate/fibre combination a statistical method is being used to plan test series which will lead to optimization of the concrete in terms of water/cement ratio, fibre content and aggregate/cement ratio. The minimum thickness of optimized concretes to resist penetration by the projectile and minimise spall and scabbing, will be determined. The mechanics of the impact andmore » penetration event are being studied and a possible method of deflecting the projectile within the concrete is suggested.« less

Fluoride Penetration and Clearance Are Higher in Exopolysaccharide-Containing Bacterial Pellets.

PubMed

Spinola, Manuela S; Nóbrega, Diego Figueiredo; Del Bel Cury, Altair Antoninha; Ricomini Filho, Antonio Pedro; Cury, Jaime Aparecido; Tenuta, Livia Maria Andaló

2018-06-06

Extracellular polysaccharides (EPS) could increase the penetration of fluoride through dental biofilm, reducing its cariogenicity. We measured the concentration of fluoride in EPS-containing (EPS+) or not-containing (EPS-) Streptococcus mutans bacterial pellets resembling test biofilms, before and up to 60 min after a 0.05% NaF rinse in situ. Fluoride penetration and clearance were higher in EPS+ bacterial pellets. The data suggest that EPS enhances fluoride penetration, but also accelerates fluoride clearance from dental biofilms. © 2018 S. Karger AG, Basel.

Titanium-Oxygen Reactivity Study

NASA Technical Reports Server (NTRS)

Chafey, J. E.; Scheck, W. G.; Witzell, W. E.

1962-01-01

A program has been conducted at Astronautics to investigate the likelihood of occurrence of the catastrophic oxidation of titanium alloy sheet under conditions which simulate certain cases of accidental failure of the metal while it is in contact with liquid or gaseous oxygen. Three methods of fracturing the metal were used; they consisted of mechanical puncture, tensile fracture of welded joints, and perforation by very high velocity particles. The results of the tests which have been conducted provide further evidence of the reactivity of titanium with liquid and gaseous oxygen. The evidence indicates that the rapid fracturing of titanium sheet while it is in contact with oxygen initiates the catastrophic oxidation reaction. Initiation occurred when the speed of the fracture was some few feet per second, as in both the drop-weight puncture tests and the static tensile fracture tests of welded joints, as well as when the speed was several thousand feet per second, as in the simulated micrometeoroid penetration tests. The slow propagation of a crack, however, did not initiate the reaction. It may logically be concluded that the localized frictional heat of rapid fracture and/or spontaneous oxidation (exothermic) of minute particles emanating from the fracture cause initiation of the reaction. Under conditions of slow fracture, however, the small heat generated may be adequately dissipated and the reaction is not initiated. A portion of the study conducted consisted of investigating various means by which the reaction might be retarded or prevented. Providing a "barrier" at the titanium-oxygen interface consisting of either aluminum metal or a coating of a petroleum base corrosion inhibitor appeared to be only partially effective in retarding the reaction. The accidental puncturing or similar rupturing of thin-walled pressurized oxygen tanks on missiles and space vehicle will usually constitute loss of function, and may sometimes cause their catastrophic destruction by explosive decompression regardless of the type of material used for their construction. In the case of tanks constructed of titanium alloys the added risk is incurred of catastrophic burning of the tanks. In view of this it is recommended that thin-walled tanks constructed of titanium alloys should not be used to contain liquid or gaseous oxygen.

Development of transferrin targeted NCL-240 micelles and their evaluation using in-vitro 3D cancer cell culture (spheroid) models

NASA Astrophysics Data System (ADS)

Nagelli, Srikar Goud

The main objective of this project was to develop targeted micellar delivery systems of a novel cytotoxic drug (NCL-240; a second generation DM-PIT-1 analog) and to evaluate their efficacy using optimized 3D cell culture spheroid models. Spheroids were optimized for several cancer cell lines using a range of techniques such as non-adhesive liquid overlay method, hanging drop method, and co-culturing. Transferrin (Tf)-conjugated NCL-240 micelles were prepared with varying Tf amounts and their cytotoxicities were evaluated using the optimized spheroid models. The uptake and penetration of the formulations were also studied using confocal microscopy. The results indicated that the concentration of NCL-240 micelles required to achieve the same cytotoxicity was relatively higher in spheroids compared to the monolayers. Also, In NCI-ADR-RES, Tf-targeted NCL-240 micelles were shown to have a significant increase in cytotoxicity compared to untargeted NCL-240 micelles. Even the penetration and uptake studies indicated that targeting improves the uptake and penetration of formulations. However, in U87-MG spheroids, there was a significant difference in cell viability among micelles compared to free drug but no significant benefit due to targeting was observed. The same formulations penetrated lesser in U87-MG spheroids compared to NCI-ADR-RES spheroids. This study thereby emphasizes the importance of drug screening in spheroid models as the penetration dynamics are varying from cell line to cell line because of the 3D structure.

Fiber-optic endoscopic evaluation of swallowing to assess swallowing outcomes as a function of head position in a normal population

PubMed Central

2014-01-01

Background Head position practice has been shown to influence pill-swallowing ability, but the impact of head position on measures of swallowing outcomes has not yet been studied with fiber-optic endoscopic evaluation of swallowing (FEES). The primary purpose of this study was to determine whether head position impacts penetration-aspiration scale scores and/or post-swallow pharyngeal residue as assessed by FEES. Documenting the incidence of pharyngeal residue and laryngeal penetration and aspiration in a normal population was a secondary goal. Methods Adults without swallowing difficulties (N = 84) were taught a pill swallowing technique based on learning five head positions and were asked to practice with small, hard candies (e.g., TicTacs) for two weeks. Then they demonstrated swallowing in each of the head positions for two conditions, liquid and purée, while undergoing FEES. Results Out of 840 examined swallows, one event of aspiration and 5 events of penetration occurred. During practice >50% participants found positions they preferred over the center position for swallowing but head position was not associated with penetration-aspiration scores assessed by FEES. Significant associations and non-significant trends were found between pharyngeal residue and three variables: age, most preferred head position, and least preferred head position. Conclusion Head position during swallowing (head up) and age greater than 40 years may result in increased pharyngeal residue but not laryngeal penetration or aspiration. PMID:24755159

Space treatments of insecticide for control of dengue virus vector Aedes aegypti in southern Mexico. I. Baseline penetration trials in open field and houses.

PubMed

Arrendondo-Jimenez, Juan I; Rivero, Norma E

2006-06-01

We studied the efficacy of space ultra-low volume treatments of 3 insecticides for the control of the dengue virus vector Aedes aegypti in southern Mexico. Insecticides tested were permethrin (Aqua-Reslin Super), d-phenothrin (Anvil), and cyfluthrin (Solfac), applied at rates of 10.87, 7.68, and 2 g/ha, respectively, by using London Fog, HP910-PHXL, or Micro-Gen pumps mounted on vehicles. Studies included 1) open field penetration tests and 2) house penetration tests. Open field tests indicated that Anvil and Solfac were more effective than Aqua-Reslin Super. In house tests, Anvil yielded the highest mosquito mortalities (>/=88%) of the three insecticides in the front porch, living room, bedroom, and backyard. Therefore, Anvil proved to be better than other insecticides evaluated to control Ae. aegypti in Chiapas, Mexico.

Nonlinear Dynamics of a Spring-Supported Piston in a Vibrated Liquid-Filled Housing: II. Experiments

NASA Astrophysics Data System (ADS)

O'Hern, T. J.; Torczynski, J. R.; Clausen, J. R.

2016-11-01

The nonlinear dynamics of a piston supported by a spring in a vibrated liquid-filled housing is investigated experimentally. The housing containing the piston and the liquid is subjected to vibrations along its axis. A post fixed to the housing penetrates a hole through the piston and produces a flow resistance that depends on piston position. Flexible bellows attached to the housing ends enable the piston, liquid, and bellows to execute a collective motion that forces little liquid through the flow resistance. The low damping of this motion leads to a resonance, at which the flow-resistance nonlinearity produces a net force on the piston that can cause it to compress its spring. Experiments are performed to investigate the nonlinear dynamics of this system, and these results are compared to theoretical and numerical results. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

A Liquid Level Measurement Technique Outside a Sealed Metal Container Based on Ultrasonic Impedance and Echo Energy

PubMed Central

Zhang, Bin; Wei, Yue-Juan; Liu, Wen-Yi; Zhang, Yan-Jun; Yao, Zong; Zhao, Li-Hui; Xiong, Ji-Jun

2017-01-01

The proposed method for measuring the liquid level focuses on the ultrasonic impedance and echo energy inside a metal wall, to which the sensor is attached directly, not on ultrasonic waves that penetrate the gas–liquid medium of a container. Firstly, by analyzing the sound field distribution characteristics of the sensor in a metal wall, this paper proposes the concept of an "energy circle" and discusses how to calculate echo energy under three different states in detail. Meanwhile, an ultrasonic transmitting and receiving circuit is designed to convert the echo energy inside the energy circle into its equivalent electric power. Secondly, in order to find the two critical states of the energy circle in the process of liquid level detection, a program is designed to help with calculating two critical positions automatically. Finally, the proposed method is evaluated through a series of experiments, and the experimental results indicate that the proposed method is effective and accurate in calibration of the liquid level outside a sealed metal container. PMID:28106857

Directional, passive liquid transport: the Texas horned lizard as a model for a biomimetic ‘liquid diode’

PubMed Central

Comanns, Philipp; Buchberger, Gerda; Buchsbaum, Andreas; Baumgartner, Richard; Kogler, Alexander; Bauer, Siegfried; Baumgartner, Werner

2015-01-01

Moisture-harvesting lizards such as the Texas horned lizard (Iguanidae: Phrynosoma cornutum) live in arid regions. Special skin adaptations enable them to access water sources such as moist sand and dew: their skin is capable of collecting and transporting water directionally by means of a capillary system between the scales. This fluid transport is passive, i.e. requires no external energy, and directs water preferentially towards the lizard's snout. We show that this phenomenon is based on geometric principles, namely on a periodic pattern of interconnected half-open capillary channels that narrow and widen. Following a biomimetic approach, we used these principles to develop a technical prototype design. Building upon the Young–Laplace equation, we derived a theoretical model for the local behaviour of the liquid in such capillaries. We present a global model for the penetration velocity validated by experimental data. Artificial surfaces designed in accordance with this model prevent liquid flow in one direction while sustaining it in the other. Such passive directional liquid transport could lead to process improvements and reduction of resources in many technical applications. PMID:26202685

Liquid Water Restricts Habitability in Extreme Deserts

NASA Astrophysics Data System (ADS)

Cockell, Charles S.; Brown, Sarah; Landenmark, Hanna; Samuels, Toby; Siddall, Rebecca; Wadsworth, Jennifer

2017-04-01

Liquid water is a requirement for biochemistry, yet under some circumstances it is deleterious to life. Here, we show that liquid water reduces the upper temperature survival limit for two extremophilic photosynthetic microorganisms (Gloeocapsa and Chroococcidiopsis spp.) by greater than 40°C under hydrated conditions compared to desiccated conditions. Under hydrated conditions, thermal stress causes protein inactivation as shown by the fluorescein diacetate assay. The presence of water was also found to enhance the deleterious effects of freeze-thaw in Chroococcidiopsis sp. In the presence of water, short-wavelength UV radiation more effectively kills Gloeocapsa sp. colonies, which we hypothesize is caused by factors including the greater penetration of UV radiation into hydrated colonies compared to desiccated colonies. The data predict that deserts where maximum thermal stress or irradiation occurs in conjunction with the presence of liquid water may be less habitable to some organisms than more extreme arid deserts where organisms can dehydrate prior to being exposed to these extremes, thus minimizing thermal and radiation damage. Life in extreme deserts is poised between the deleterious effects of the presence and the lack of liquid water.

Skin penetration assessment of less lethal kinetic energy munitions.

PubMed

Bir, Cynthia A; Stewart, Shelby J; Wilhelm, Marianne

2005-11-01

The development of less-lethal technologies has provided law enforcement personnel with an alternative to lethal force. Although the less lethal projectile was produced to engender non-penetrating wounds, case studies show that there have been a number of reported penetrating injuries ranging from minor to significant in morbidity. The objective of this study was to determine the energy per unit area required to penetrate various regions of the body. Eight unembalmed postmortem human specimens were procured for this testing. Each specimen sustained a maximum of 25 impacts consisting of shots to the anterior and posterior thorax, abdomen, and legs. A 12-gauge, fin-stabilized, rubber rocket round was used as the impactor for all of the conducted tests. The energy density required for 50% risk of penetration varied from 23.99 J/cm2 for the location on the anterior rib (p = 0.000) to 52.74 J/cm2 for the location on the posterior rib (p = 0.001).

Correlation of microstructure with dynamic deformation behavior and penetration performance of tungsten heavy alloys fabricated by mechanical alloying

NASA Astrophysics Data System (ADS)

Kim, Dong-Kuk; Lee, Sunghak; Ryu, Ho Jin; Hyunghong, Soon; Noh, Joon-Woong

2000-10-01

In this study, tungsten heavy alloy specimens were fabricated by mechanical alloying (MA), and their dynamic torsional properties and penetration performance were investigated. Dynamic torsional tests were conducted on the specimens fabricated with different sintering temperatures after MA, and then the test data were compared with those of a conventionally processed specimen. Refinement of tungsten particles was obtained after MA, but contiguity was seriously increased, thereby leading to low ductility and impact energy. Specimens in which both particle size and contiguity were simultaneously reduced by MA and two-step sintering and those having higher matrix fraction by partial MA were successfully fabricated. The dynamic test results indicated that the formation of adiabatic shear bands was expected because of the plastic localization at the central area of the gage section. Upon highspeed impact testing of these specimens, self-sharpening was promoted by the adiabatic shear band formation, but their penetration performance did not improve since much of kinetic energy of the penetrators was consumed for the microcrack formation due to interfacial debonding and cleavage fracture of tungsten particles. In order to improve penetration performance as well as to achieve selfsharpening by applying MA, conditions of MA and sintering process should be established so that alloy densification, particle refinement, and contiguity reduction can be simultaneously achieved.

Effect of photodynamic therapy and non-thermal plasma on root canal filling: analysis of adhesion and sealer penetration.

PubMed

Menezes, Marilia; Prado, Maíra; Gomes, Brenda; Gusman, Heloisa; Simão, Renata

2017-01-01

The aim of this study was to evaluate the effect of photodynamic therapy (PDT) and non-thermal plasma (NTP) on adhesion and sealer penetration in root canals. Sixty single-rooted premolars were used. The teeth were prepared using a crown-down technique. NaOCl and EDTA were used for irrigation and smear layer removal, respectively. The root canals were divided into three groups: control, PDT, and NTP. After treatments, the roots were filled using gutta-percha and either AH Plus (AHP) or MTA Fillapex (MTAF) sealers. Samples were sectioned at 4, 8, and 12 mm from the apex (1-mm slices)and analyzed by the push-out bond strength test (adhesion) and confocal laser scanning microscopy (sealer penetration). Data were statistically evaluated using Kruskal-Wallis, Dunn's, and Spearman's tests. Regarding AHP, bond strength was similar in the NTP group and in the control group, but significantly lower in the PDT group. As to MTAF, both therapies showed lower values than the control group. In the confocal analysis of AHP, maximum and mean penetration, and penetrated area were statistically higher in the control group than in the PDT and NTP groups. Penetrated perimeter was similar among groups. Regarding MTAF, all parameters yielded better results in the NTP than in the control group. The PDT and control groups showed similar results except for penetrated area. PDT and plasma therapy affected the adhesion and sealer penetration of root canals filled with AH Plus and MTA Fillapex and there is no positive correlation between adhesion and sealer penetration.

Thermodynamics of interaction of ionic liquids with lipid monolayer.

PubMed

Bhattacharya, G; Mitra, S; Mandal, P; Dutta, S; Giri, R P; Ghosh, S K

2018-06-01

Understanding the interaction of ionic liquids with cellular membrane becomes utterly important to comprehend the activities of these liquids in living organisms. Lipid monolayer formed at the air-water interface is employed as a model system to follow this interaction by investigating important thermodynamic parameters. The penetration kinetics of the imidazolium-based ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate ([DMIM][BF4]) into the zwitterionic 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid layer is found to follow the Boltzmann-like equation that reveals the characteristic time constant which is observed to be the function of initial surface pressure. The enthalpy and entropy calculated from temperature-dependent pressure-area isotherms of the monolayer show that the added ionic liquids bring about a disordering effect in the lipid film. The change in Gibbs free energy indicates that an ionic liquid with longer chain has a far greater disordering effect compared to an ionic liquid with shorter chain. The differential scanning calorimetric measurement on a multilamellar vesicle system shows the main phase transition temperature to shift to a lower value, which, again, indicates the disordering effect of the ionic liquid on lipid membrane. All these studies fundamentally point out that, when ionic liquids interact with lipid molecules, the self-assembled structure of a cellular membrane gets perturbed, which may be the mechanism of these molecules having adverse effects on living organisms.

Hot cracking during welding and casting

NASA Astrophysics Data System (ADS)

Cao, Guoping

Aluminum welds are susceptible to liquation cracking in the partially melted zone (PMZ). Using the multicomponent Scheil model, curves of temperature vs. fraction solid (T-fS) during solidification were calculated for the PMZ and weld metals (WMs). These curves were used to predict the crack susceptibility by checking if the harmful condition of WM fS > PMZ fS exists during PMZ solidification and reduce the susceptibility by minimizing this condition. This approach was tested against full-penetration welds of alloys 7075 and 2024 and it can be used to guide the selection or development of filler metals. Liquation cracking in the PMZ in welds of Al-Si cast alloys was also investigated. The crack susceptibility was evaluated by circular-patch test, and full-penetration welds made with filler metals 1100, 4043, 4047 and 5356. Liquation cracking was significant with filler metals 1100 and 5356 but slight with filler metals 4043 and 4047. In all welds, liquation cracks were completely backfilled, instead of open as in full-penetration welds of wrought alloys 2219 and 6061. The T-fS curves showed that alloy A357 has a much higher fraction liquid for backfilling before PMZ solidification was essentially over. Hot tearing in Mg-xAl-yCa alloys was studied by constrained rod casting (CRC) in a steel mold. The hot tearing susceptibility decreased significantly with increasing Ca content (y) but did not change much with the Al content (x). An instrumented CRC with a steel mold was developed to detect the onset of hot tearing. The secondary phases, eutectic content, solidification path, and freezing range were examined. Hot tearing in Mg-Al-Sr alloys was also studied by CRC in a steel mold. With Mg-(4,6,8)Al-1.5Sr alloys, the hot tearing susceptibility decreased significantly with increasing Al content. With Mg-(4,6,8)Al-3Sr alloys, the trend was similar but not as significant. At the same Al content, the hot tearing susceptibility decreased significantly with increasing Sr content. Instrumented CRC with a steel mold was also used to test hot tearing of Mg-Al-Sr alloys. Cracking occurred at a higher temperature in alloys most susceptible to cracking than in alloys least susceptible.

The impact of hazardous waste leachate on performance of clay liners.

PubMed

Mosavat, Nasim; Nalbantoglu, Zalihe

2013-02-01

Penetration of hazardous liquids through waste containment barriers exerts contamination and considerable alterations in geotechnical properties of clay liners. In general, these changes are attributed to the variation of the dielectric constant and the chemistry of the pore fluids which cause changes in soil structure. In the present study, a series of laboratory tests were performed on natural and contaminated clay soil permeated with different hazardous liquids: ethylene glycol and toluene which are generally found in petroleum-contaminated sites, possessing intermediate and low dielectric constants. Toluene was used in its pure form and ethylene glycol was used at various percentages of 0, 20, 40 and 60% by the volume of distilled water. In addition, natural sea water was also utilized as an inorganic fluid for permeation and salinization of the clay soil. The overall test results indicated that plasticity, sedimentation time, unconfined compressive strength, swell and compressibility generally decreased with increasing organic fluid/water concentration, while a slight increase in the permeability values was observed. Pure toluene resulted in diminution of plasticity and considerable flocculation of the particles which caused the soil to become granular. Sea water also caused particle flocculation and reduction in plasticity, swell potential and unconfined compressive strength, although it was noted that compressibility properties remained unchanged compared to distilled water. Finally, the correlation between the electrical resistivity and plasticity index values suggested that the electrical resistivity measurements can be used as a detecting technique for subsurface soil and waste barrier contamination.

Seeding Experiment of Liquid Carbon Dioxide for Enhancing Winter-time Precipitation in Saga Prefecture,Northern Kyushu,Japan

NASA Astrophysics Data System (ADS)

Wakimizu, K.; Nishiyama, K.; Tomine, K.; Maki, T.; Suzuki, Y.; Morita, O.

2012-12-01

Many droughts (shortage of water) have broken out by extreme small amount rainfall in recent Japan. So far,in order to prevent these droughts,artificial rainfall methods with 'AgI' or 'dry ice' have been widely used in Japan. However,these methods have many problems,which a large amount of overcooling liquid in the cumulus cloud was not able to be converted into precipitation efficiently. So as to solve these problems,new artificial rainfall method using liquid carbon dioxide (LC) was proposed by Fukuta (1996). This new method consists of the generation of ice particles by homogeneous nucleation using LC and the subsequent more effective growth for ice particles without competition process. And, this method is called 'Low-Level Penetration Seeding of Homogeneous Ice Nucleant (LOLEPSHIN)' ; this induces a 'Roll-up Expansion of Twin Horizontal Ice-crystal Thermals (RETHIT)' and a subsequent 'Falling growth-Induced Lateral Air Spreading (FILAS)'. This LC method was applied to thin super-cooled cumulus clouds in Saga prefecture, Northern Kyushu, Japan on February 4,2006. The seeding airplane took off the Atugi Airport in Kanagawa Prefecture toward the Iki Island around 0830JST. Many cloud bands were cofirmed in the flight going to the experimental area and the cloud base temperature was approximately -9C (1200m). Scince some young developing thin cumuli were found over the Iki Island, LC seeding to these clouds was carried out two times from 0841JST until 0919JST penetrating the -9C (1200m) altitude. The first precipitation seeding ebded in failure. The second penetration seeding was done for 115 seconds around 0917JST. This penetration led to success of developing one artificial echo (Echo I) in the leeward side of the Iki Island. Eco I moved from NNW to SSW. The maximum area of Echo I were 48km2 (at 1033JST) and first comfirmed by the Kyushu University radar (KU radar) at 1006JST (46 min. after LC seeding) around Mt.Sefuri in Saga Prefecture. It can be inferred that ice perticles formed by LC seeding grew to the precipitable size and resultant snowfall was detected by radar in approximately 120 min. after seeding operation. In this study, based on these observed facts, optimum design for enhancing winter-time water resources by LC seeding method was suggested. Successive low-level horizontal penetrations of operational aircraft with seeding LC into many moving super-cooled cumuli towards the Japan Islands will lead to the spreading of cloud volume and subsequent coversion of large amount of iv active cloud volume into newly exploited artificial precipitation. As a result, these experiments succeeded, and the total amount of estimated radar precipitation of the be able to secure a large amount of water resource from these experiment results.

Thermal Conductivity Measurement of Liquids by Using a Suspended Microheater

NASA Astrophysics Data System (ADS)

Oh, Dong-Wook

2017-10-01

In this paper, the traditional 3ω method is modified in order to measure the thermal conductivity of a droplet of liquid. The 3ω sensor is microfabricated using bulk silicon etching on a silicon wafer to form a microheater on a suspended bridge structure. The Si substrate of over 400 μ m thickness beneath the microheater is etched away so that the sample liquid can fill the gap created between the heater and the bottom boundary of the sensor. The frequency of the sinusoidal heating pulses that are generated from the heater is controlled such that the thermal penetration depth is much smaller than the thickness of the liquid layer. The temperature oscillation of the sample fluid is measured at the thin-film heater to calculate the thermal conductivity of the surrounding fluid. The thermal conductivity and measured values of the de-ionized water and ethanol show a good agreement with the theoretical values at room temperature.

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...

Polymer-Reinforced, Non-Brittle, Lightweight Cryogenic Insulation

NASA Technical Reports Server (NTRS)

Hess, David M.

2013-01-01

The primary application for cryogenic insulating foams will be fuel tank applications for fueling systems. It is crucial for this insulation to be incorporated into systems that survive vacuum and terrestrial environments. It is hypothesized that by forming an open-cell silica-reinforced polymer structure, the foam structures will exhibit the necessary strength to maintain shape. This will, in turn, maintain the insulating capabilities of the foam insulation. Besides mechanical stability in the form of crush resistance, it is important for these insulating materials to exhibit water penetration resistance. Hydrocarbon-terminated foam surfaces were implemented to impart hydrophobic functionality that apparently limits moisture penetration through the foam. During the freezing process, water accumulates on the surfaces of the foams. However, when hydrocarbon-terminated surfaces are present, water apparently beads and forms crystals, leading to less apparent accumulation. The object of this work is to develop inexpensive structural cryogenic insulation foam that has increased impact resistance for launch and ground-based cryogenic systems. Two parallel approaches will be pursued: a silica-polymer co-foaming technique and a post foam coating technique. Insulation characteristics, flexibility, and water uptake can be fine-tuned through the manipulation of the polyurethane foam scaffold. Silicate coatings for polyurethane foams and aerogel-impregnated polyurethane foams have been developed and tested. A highly porous aerogel-like material may be fabricated using a co-foam and coated foam techniques, and can insulate at liquid temperatures using the composite foam

Cell-Penetrating CaCO3 Nanocrystals for Improved Transport of NVP-BEZ235 across Membrane Barrier in T-Cell Lymphoma

PubMed Central

Civallero, Monica; Citti, Cinzia; Cosenza, Maria; Baldassarre, Francesca; Cannazza, Giuseppe; Pozzi, Samantha; Sacchi, Stefano

2018-01-01

Owing to their nano-sized porous structure, CaCO3 nanocrystals (CaCO3NCs) hold the promise to be utilized as desired materials for encapsulating molecules which demonstrate wide promise in drug delivery. We evaluate the possibility to encapsulate and release NVP-BEZ235, a novel and potent dual PI3K/mTOR inhibitor that is currently in phase I/II clinical trials for advanced solid tumors, from the CaCO3NCs. Its chemical nature shows some intrinsic limitations which induce to administer high doses leading to toxicity; to overcome these problems, here we proposed a strategy to enhance its intracellular penetration and its biological activity. Pristine CaCO3 NCs biocompatibility, cell interactions and internalization in in vitro experiments on T-cell lymphoma line, were studied. Confocal microscopy was used to monitor NCs-cell interactions and cellular uptake. We have further investigated the interaction nature and release mechanism of drug loaded/released within/from the NCs using an alternative approach based on liquid chromatography coupled to mass spectrometry. Our approach provides a good loading efficiency, therefore this drug delivery system was validated for biological activity in T-cell lymphoma: the anti-proliferative test and western blot results are very interesting because the proposed nano-formulation has an efficiency higher than free drug at the same nominal concentration. PMID:29370086

Development and assessment of sterility of a closed-system pediatric peritoneal dialysis.

PubMed

Biazi, Ana Paula Pereira; Croti, Ulisses Alexandre; Braile, Domingo Marcolino; Oliveira, Marcos Aurélio Barboza de; Costa, Jane Gonçalves Soares; Cardoso, Lucas Monteiro

2009-01-01

To develop an easy-handling totally closed pediatric peritoneal dialysis system and assess the sterility assurance level. From February to December 2008 was designed and developed a closed-system pediatric peritoneal dialysis at the Bioengineering Division of Braile Biomédica Indústria, Comércio e Representações S/A. Twenty systems were manufactured and submitted to sterility assurance level testing, and were divided into Group A (10)--using the sterility test--and B (10)--ethylene oxide gas penetration. In Group A, the sterility test was negative for bacteria and fungi proliferation within 14 days in all systems. In Group B, the gas penetration test showed that there was gas penetration in all points assessed. It was possible to develop a new easy-handling closed-system pediatric peritoneal dialysis and ensure its sterility.

Routine Testing of Bitumen Binders

NASA Astrophysics Data System (ADS)

Holý, Michal; Remišová, Eva

2017-12-01

The quality of bituminous binders used in the construction and maintenance of road surfaces is currently assessed by empirical testing based on obtaining one value for specific boundary conditions, which were designed about 100 years ago. Basic empirical tests include the softening point and penetration, but the practice shows that these tests appear to be inadequate. The evaluation of changes of bitumen properties during the production and paving process of bituminous mixture is also important. The paper points out how the "traditional" tests as softening point and penetration and viscosity are sufficient to evaluate properties of bitumen binders.

Palatability and Preference of Gummi Formulations with Various Pharmaceutical Characteristics.

PubMed

Nakagaki, Fumiaki; Uchida, Shinya; Tanaka, Shimako; Namiki, Noriyuki

2018-01-01

This study aimed to elucidate the appropriate physical characteristics that are clinically acceptable for gummi formulations. We prepared 11 placebo gummi formulations containing different amounts of gelatin and water and evaluated their penetration and restitution using a penetrometer and rheometer, respectively. Clinical sensory tests in 16 healthy volunteers (age, 23.4±0.9 years, mean±standard deviation) were conducted on the placebo gummi formulations using the visual analog scale (VAS) score to evaluate elasticity, hardness, and overall palatability, with a 5-point rating scale of preference. The penetration increased with decreasing amounts of gelatin or increasing amounts of water in the gummi formulations. Similarly, the VAS score of elasticity and hardness from the clinical sensory tests increased with increasing amounts of gelatin but decreased with increasing amounts of water. The relationship between the penetration and VAS scores of elasticity and hardness revealed good linear correlations. This suggests that the penetration was well reflected by the hardness results of the clinical VAS scores. The overall palatability evaluated using the VAS score increased until the penetration was 10 mm and then plateaued at >10 mm penetration. The 5-point rating score for preference revealed that >50% of volunteers "prefer" the gummi formulations with penetration values of 9.8 to 13.5 mm. These results suggest that gummi formulations likely have an appropriate window of hardness. Furthermore, appropriate gummi formulations with clinically preferred physical characteristics could be prepared by adjusting the amount of gelatin and water and measuring their penetration.

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

Odraskova, M.; Szalay, Z.; Zahoranova, A.

Diffuse Coplanar Surface Barrier Discharge was successfully tested for creating a water-repellent surface from HMDSO and HMDS compounds on samples of spruce wood (Picea abies, Karst). The best results were achieved when the treated sample was in continuous motion during the course of film deposition. Best hydrophobic coating was achieved for 29% of total gas flow through the HMDSO and HMDS liquid. The surface free energy of modified surface was 30 mJ/m{sup 2} for HMDSO and 24 mJ/m{sup 2} for HMDS mixtures. The 50 {mu}l water droplet required (180{+-}30) min to penetrate into the modified spruce in HMDSO mixture andmore » (213{+-}30) min in HMDS mixture. This is more than 20 fold increase compared to the unmodified spruce. The chemical composition of deposited layer was analyzed by ATR-FTIR. The presence of Si-O-Si and Si(CH{sub 3}) functional groups was confirmed.« less

Laboratory Investigation of a Leaking Type 316 Socket Weld in a Boron Injection Tank Sampling Line

NASA Astrophysics Data System (ADS)

Xu, Hongqing; Fyfitch, Steve; Hosier, Ryan; Hyres, James

A leak was discovered in a Type 316 stainless steel socket weld in the sampling line for the boron injection tank. A section of the pipeline containing the leaking weld was removed for laboratory investigation that included visual and Stereovisual inspections, liquid penetrant (PT) testing, metallography, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and ferrite content determinations. The leak path was a through-wall transgranular crack in the socket weld. Cracking initiated along the weld-metal-to-base-metal interface at the tip of the crevice between the socket and pipe. The crevice was exposed to oxygenated boron solution at <180°F. Shallow intergranular attack (IGA) was found in the exposed base metal inside the crevice. Based on the investigation results, it was concluded that transgranular stress corrosion cracking (TGSCC) is the primary cracking mechanism.

Secondary Containment Design for the LLNL B801 Diala Oil Tank

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

Mertesdorf, E.

2016-12-14

Design is to add an extension to the secondary containment of tank T1-A3 at building 801. Piping from the inner tank penetrates the secondary containment tank below the liquid level of the primary tank. To meet Oil Pollution Prevention Regulation 40 CFR 120.7 the single wall piping needs to be provided with secondary containment. Steel Tank Institute (STI) conference publication states: §112.3(d)(1)(iii) –SPCC Plan requirements- Systems shall be designed in accordance with good engineering practice, including consideration of applicable industry standards and that procedures for required inspections and testing have been established. Section 112.7(a)(2) allows for deviations from specific rulemore » requirements, provided the Owner/operator responsible to select, document and implement alternate measure and a PE certifies the SPCC Plan in accordance with good engineering practices, including consideration of industry standards« less

Chemical, Biological, and Radiological (CBR) Contamination Survivability, Large Item Interiors

DTIC Science & Technology

2016-08-03

e.g., mud, grease, etc.). m. Pretest (baseline) and posttest (30 days after the first contamination and/or other defined long-term time interval...procedures used. f. Description of SUT-interior materials of construction, paint type, and surface condition (pretest and posttest ), including...difficult to decontaminate or allow liquid to penetrate. g. Pretest and posttest ME functional performance characteristics (when measured) used as

Hydrodynamics of the Fluid Filtrate on Drilling-In

NASA Astrophysics Data System (ADS)

Abbasov, É. M.; Agaeva, N. A.

2014-01-01

The volume of the liquid penetrating into the formation after drilling-in has been determined on the basis of theoretical investigations. The dynamics of change in the bottom-hole pressure has been determined in this process. It has been shown that because of the water hammer, the bottom-hole pressure can be doubled in the presence of large fractures and pores closer to the well-bottom zone.

Analysis of pumping tests of partially penetrating wells in an unconfined aquifer using inverse numerical optimization

NASA Astrophysics Data System (ADS)

Hvilshøj, S.; Jensen, K. H.; Barlebo, H. C.; Madsen, B.

1999-08-01

Inverse numerical modeling was applied to analyze pumping tests of partially penetrating wells carried out in three wells established in an unconfined aquifer in Vejen, Denmark, where extensive field investigations had previously been carried out, including tracer tests, mini-slug tests, and other hydraulic tests. Drawdown data from multiple piezometers located at various horizontal and vertical distances from the pumping well were included in the optimization. Horizontal and vertical hydraulic conductivities, specific storage, and specific yield were estimated, assuming that the aquifer was either a homogeneous system with vertical anisotropy or composed of two or three layers of different hydraulic properties. In two out of three cases, a more accurate interpretation was obtained for a multi-layer model defined on the basis of lithostratigraphic information obtained from geological descriptions of sediment samples, gammalogs, and flow-meter tests. Analysis of the pumping tests resulted in values for horizontal hydraulic conductivities that are in good accordance with those obtained from slug tests and mini-slug tests. Besides the horizontal hydraulic conductivity, it is possible to determine the vertical hydraulic conductivity, specific yield, and specific storage based on a pumping test of a partially penetrating well. The study demonstrates that pumping tests of partially penetrating wells can be analyzed using inverse numerical models. The model used in the study was a finite-element flow model combined with a non-linear regression model. Such a model can accommodate more geological information and complex boundary conditions, and the parameter-estimation procedure can be formalized to obtain optimum estimates of hydraulic parameters and their standard deviations.

Numerical Investigation on Sensitivity of Liquid Jet Breakup to Physical Fuel Properties with Experimental Comparison

NASA Astrophysics Data System (ADS)

Kim, Dokyun; Bravo, Luis; Matusik, Katarzyna; Duke, Daniel; Kastengren, Alan; Swantek, Andy; Powell, Christopher; Ham, Frank

2016-11-01

One of the major concerns in modern direct injection engines is the sensitivity of engine performance to fuel characteristics. Recent works have shown that even slight differences in fuel properties can cause significant changes in efficiency and emission of an engine. Since the combustion process is very sensitive to the fuel/air mixture formation resulting from disintegration of liquid jet, the precise assessment of fuel sensitivity on liquid jet atomization process is required first to study the impact of different fuels on the combustion. In the present study, the breaking process of a liquid jet from a diesel injector injecting into a quiescent gas chamber is investigated numerically and experimentally for different liquid fuels (n-dodecane, iso-octane, CAT A2 and C3). The unsplit geometric Volume-of-Fluid method is employed to capture the phase interface in Large-eddy simulations and results are compared against the radiography measurement from Argonne National Lab including jet penetration, liquid mass distribution and volume fraction. The breakup characteristics will be shown for different fuels as well as droplet PDF statistics to demonstrate the influences of the physical properties on the primary atomization of liquid jet. Supported by HPCMP FRONTIER award, US DOD, Office of the Army.

Improved OCT imaging of lung tissue using a prototype for total liquid ventilation

NASA Astrophysics Data System (ADS)

Schnabel, Christian; Meissner, Sven; Koch, Edmund

2011-06-01

Optical coherence tomography (OCT) is used for imaging subpleural alveoli in animal models to gain information about dynamic and morphological changes of lung tissue during mechanical ventilation. The quality of OCT images can be increased if the refraction index inside the alveoli is matched to the one of tissue via liquid-filling. Thereby, scattering loss can be decreased and higher penetration depth and tissue contrast can be achieved. Until now, images of liquid-filled lungs were acquired in isolated and fixated lungs only, so that an in vivo measurement situation is not present. To use the advantages of liquid-filling for in vivo imaging of small rodent lungs, it was necessary to develop a liquid ventilator. Perfluorodecalin, a perfluorocarbon, was selected as breathing fluid because of its refraction index being similar to the one of water and the high transport capacity for carbon dioxide and oxygen. The setup is characterized by two independent syringe pumps to insert and withdraw the fluid into and from the lung and a custom-made control program for volume- or pressure-controlled ventilation modes. The presented results demonstrate the liquid-filling verified by optical coherence tomography and intravital microscopy (IVM) and the advantages of liquid-filling to OCT imaging of subpleural alveoli.

Direct Numerical Simulation of Liquid Transport Through Fibrous Porous Media

NASA Astrophysics Data System (ADS)

Palakurthi, Nikhil Kumar

Fluid flow through fibrous media occurs in many industrial processes, including, but not limited, to fuel cell technology, drug delivery patches, sanitary products, textile reinforcement, filtration, heat exchangers, and performance fabrics. Understanding the physical processes involved in fluid flow through fibrous media is essential for their characterization as well as for the optimization and development of new products. Macroscopic porous-media equations require constitutive relations, which account for the physical processes occurring at the micro-scale, to predict liquid transport at the macro-scale. In this study, micro-scale simulations were conducted using conventional computational fluid dynamics (CFD) technique (finite-volume method) to determine the macroscopic constitutive relations. The first part of this thesis deals with the single-phase flow in fibrous media, following which multi-phase flow through fibrous media was studied. Darcy permeability is an important parameter that characterizes creeping flow through a fibrous porous medium. It has a complex dependence on the medium's properties such as fibers' in-plane and through-plane orientation, diameter, aspect ratio, curvature, and porosity. A suite of 3D virtual fibrous structures with a wide range of geometric properties were constructed, and the permeability values of the structures were calculated by solving the 3D incompressible Navier-Stokes equations. The through-plane permeability was found to be a function of only the fiber diameter, the fibers' through-plane orientation, and the porosity of the medium. The numerical results were used to extend a permeability-porosity relation, developed in literature for 3D isotropic fibrous media, to a wide range of fibers' through-plane orientations. In applications where rate of capillary penetration is important, characterization of porous media usually involves determination of either the effective pore radius from capillary penetration experiments or a representative pore radius (R50) from pore-size distribution data. The relationship between effective and representative pore radii was studied by performing direct simulations of capillary penetration of a wetting liquid using a finite-volume-based volume-of-fluid (VOF) method. The simulated unidirectional liquid penetration through fibrous media followed Lucas-Washburn kinetics (L ˜ t1/2), except during the initial stages, which are dominated by inertial forces. Even though fluid properties and contact angle were kept constant in the simulations, the effective pore radii were found to be quite different from the representative radii. It can be concluded that the differences between effective and representative pore radii did not arise from contact angle variations. The unsaturated flow through fibrous media at the macro-scale is typically described using Richard's equation which requires constitutive relations: capillary pressure and permeability as a function of liquid saturation. In the present study, the quasi-static capillary pressure-saturation (P c-S) relationship for the primary drainage in a 3D isotropic fibrous medium was determined by performing micro-scale simulations using a VOF method. The Pc-S relationship obtained from the VOF method was compared with the results from the full-morphology (FM) method. Good agreement was observed between the results from the VOF and FM methods, thus suggesting that the FM method, a computationally less intensive method as compared to VOF method, may be sufficient for estimating the Pc-S relationship for primary drainage.

Diesel Fuel Property Effects on In-Cylinder Liquid Penetration Length: Impact on Smoke Emissions and Equivalence Ratio Estimates at the Flame Lift-Off Length

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

Dumitrescu, Cosmin E.; Polonowski, Christopher J.; Fisher, Brian T.

Here in this study, elastic scattering was employed to investigate diesel fuel property effects on the liquid length (i.e., the maximum extent of in-cylinder liquid-phase fuel penetration) using select research fuels: an ultralow-sulfur #2 diesel emissions-certification fuel (CF) and four of the Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) diesel fuels (F1, F2, F6, and F8). The experiments were performed in a single-cylinder heavy-duty optical compression-ignition engine under time-varying, noncombusting conditions to minimize the influence of chemical heat release on the liquid-length measurement. The FACE diesel fuel and CF liquid lengths under combusting conditions were also predicted using Siebers’ scaling law and pressure data from previous work using the same fuels at similar in-cylinder conditions. The objective was to observe if the liquid length under noncombusting or combusting conditions provides additional insights into the relationships among the main fuel properties (i.e., cetane number (CN), the 90 vol % distillation recovery temperature (T90), and aromatic content) and smoke emissions. Results suggest that liquid-length values are best correlated to fuel distillation characteristics measured with ASTM D2887 (simulated distillation method). This work also studied the relationship between liquid length and lift-off length, H (i.e., distance from the fuel-injector orifice exit to the position where the standing premixed autoignition zone stabilizes during mixing-controlled combustion). Two possible cases were identified based on the relative magnitudes of liquid length under combusting conditions (Lc) and H. The low-CN fuels are representative of the first case, L c < H, in which the fuel is always fully vaporized at H. The high-CN fuels are mostly representative of the second case, L c ≥ H, in which there is still liquid fuel at H. Lc ≥ H would suggest higher smoke emissions, but there is not enough evidence in this work to support a compounding effect of a longer liquid length on top of the aromatic-content effect on smoke emissions for fuels with similar CN, supporting previous findings in the literature that lift-off length plays a more important role than liquid-length on diesel combustion. At the same time, the experimental results suggest a decrease in the fuel-jet spreading angle, i.e., a decrease in the entrainment rate into the jet at and downstream of H, under combusting conditions, that is not accounted for in the model used to predict the values ofmore » $$\\phi$$(H). Lastly, as a result, L c may be of interest for accurate predictions of $$\\phi$$(H), especially for combustion strategies designed to lower in-cylinder soot by operating near or below the nonsooting $$\\phi$$(H)-value (i.e., $$\\phi$$(H) ≈ 2).« less

Diesel Fuel Property Effects on In-Cylinder Liquid Penetration Length: Impact on Smoke Emissions and Equivalence Ratio Estimates at the Flame Lift-Off Length

DOE PAGES

Dumitrescu, Cosmin E.; Polonowski, Christopher J.; Fisher, Brian T.; ...

2015-10-05

Here in this study, elastic scattering was employed to investigate diesel fuel property effects on the liquid length (i.e., the maximum extent of in-cylinder liquid-phase fuel penetration) using select research fuels: an ultralow-sulfur #2 diesel emissions-certification fuel (CF) and four of the Coordinating Research Council (CRC) Fuels for Advanced Combustion Engines (FACE) diesel fuels (F1, F2, F6, and F8). The experiments were performed in a single-cylinder heavy-duty optical compression-ignition engine under time-varying, noncombusting conditions to minimize the influence of chemical heat release on the liquid-length measurement. The FACE diesel fuel and CF liquid lengths under combusting conditions were also predicted using Siebers’ scaling law and pressure data from previous work using the same fuels at similar in-cylinder conditions. The objective was to observe if the liquid length under noncombusting or combusting conditions provides additional insights into the relationships among the main fuel properties (i.e., cetane number (CN), the 90 vol % distillation recovery temperature (T90), and aromatic content) and smoke emissions. Results suggest that liquid-length values are best correlated to fuel distillation characteristics measured with ASTM D2887 (simulated distillation method). This work also studied the relationship between liquid length and lift-off length, H (i.e., distance from the fuel-injector orifice exit to the position where the standing premixed autoignition zone stabilizes during mixing-controlled combustion). Two possible cases were identified based on the relative magnitudes of liquid length under combusting conditions (Lc) and H. The low-CN fuels are representative of the first case, L c < H, in which the fuel is always fully vaporized at H. The high-CN fuels are mostly representative of the second case, L c ≥ H, in which there is still liquid fuel at H. Lc ≥ H would suggest higher smoke emissions, but there is not enough evidence in this work to support a compounding effect of a longer liquid length on top of the aromatic-content effect on smoke emissions for fuels with similar CN, supporting previous findings in the literature that lift-off length plays a more important role than liquid-length on diesel combustion. At the same time, the experimental results suggest a decrease in the fuel-jet spreading angle, i.e., a decrease in the entrainment rate into the jet at and downstream of H, under combusting conditions, that is not accounted for in the model used to predict the values ofmore » $$\\phi$$(H). Lastly, as a result, L c may be of interest for accurate predictions of $$\\phi$$(H), especially for combustion strategies designed to lower in-cylinder soot by operating near or below the nonsooting $$\\phi$$(H)-value (i.e., $$\\phi$$(H) ≈ 2).« less

Ground penetrating radar evaluation and implementation.

DOT National Transportation Integrated Search

2014-07-01

Six commercial ground penetrating radar (GPR) : systems were evaluated to determine the state-of-the-art of GPR technologies for railroad track : substructure inspection. : Phase 1 evaluated GPR ballast inspection : techniques by performing testing a...

Network Penetration Testing and Research

NASA Technical Reports Server (NTRS)

Murphy, Brandon F.

2013-01-01

This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised network, computers and devices can be penetrated through deployed exploits. This paper will illustrate the research done to test ability to penetrate a network without user interaction, in order to retrieve personal information from a targeted host.

Calcified lesion modeling for excimer laser ablation

NASA Astrophysics Data System (ADS)

Scott, Holly A.; Archuleta, Andrew; Splinter, Robert

2009-06-01

Objective: Develop a representative calcium target model to evaluate penetration of calcified plaque lesions during atherectomy procedures using 308 nm Excimer laser ablation. Materials and Methods: An in-vitro model representing human calcified plaque was analyzed using Plaster-of-Paris and cement based composite materials as well as a fibrinogen model. The materials were tested for mechanical consistency. The most likely candidate(s) resulting from initial mechanical and chemical screening was submitted for ablation testing. The penetration rate of specific multi-fiber catheter designs and a single fiber probe was obtained and compared to that in human cadaver calcified plaque. The effects of lasing parameters and catheter tip design on penetration speed in a representative calcified model were verified against the results in human cadaver specimens. Results: In Plaster of Paris, the best penetration was obtained using the single fiber tip configuration operating at 100 Fluence, 120 Hz. Calcified human lesions are twice as hard, twice as elastic as and much more complex than Plaster of Paris. Penetration of human calcified specimens was highly inconsistent and varied significantly from specimen to specimen and within individual specimens. Conclusions: Although Plaster of Paris demonstrated predictable increases in penetration with higher energy density and repetition rate, it can not be considered a totally representative laser ablation model for calcified lesions. This is in part due to the more heterogeneous nature and higher density composition of cadaver intravascular human calcified occlusions. Further testing will require a more representative model of human calcified lesions.

Assault frequency and preformation probability of the {alpha} emission process

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

Zhang, H. F.; Royer, G.; Li, J. Q.

2011-08-15

A study of the assault frequency and preformation factor of the {alpha}-decay description is performed from the experimental {alpha}-decay constant and the penetration probabilities calculated from the generalized liquid-drop model (GLDM) potential barriers. To determine the assault frequency a quantum-mechanical method using a harmonic oscillator is introduced and leads to values of around 10{sup 21} s{sup -1}, similar to the ones calculated within the classical method. The preformation probability is around 10{sup -1}-10{sup -2}. The results for even-even Po isotopes are discussed for illustration. While the assault frequency presents only a shallow minimum in the vicinity of the magic neutronmore » number 126, the preformation factor and mainly the penetrability probability diminish strongly around N=126.« less

Results of detailed analyses performed on boring cores extracted from the concrete floors of the Fukushima Daiichi nuclear power plant reactor buildings

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

Maeda, Koji; Sasaki, S.; Kumai, M.

Due to the massive earthquake and tsunami on March 11, 2011, and the following severe accident at the Fukushima Daiichi Nuclear Power Plant, concrete surfaces within the reactor buildings were exposed to radioactive liquid and vapor phase contaminants. In order to clarify the situation of this contamination in the reactor buildings of Units 1, 2 and 3, selected samples were transported to the Fuels Monitoring Facility in the Oarai Engineering Center of JAEA where they were subjected to analyses to determine the surface radionuclide concentrations and to characterize the radionuclide distributions in the samples. In particular, penetration of radiocesium inmore » the surface coatings layer and sub-surface concrete was evaluated. The analysis results indicate that the situation of contamination in the building of Unit 2 was different from others, and the protective surface coatings on the concrete floors provided significant protection against radionuclide penetration. The localized penetration of contamination in the concrete floors was found to be confined within a millimeter of the surface of the coating layer of some millimeters. (authors)« less

A Comparison of the Capability of Sensitivity Level 3 and Sensitivity Level 4 Fluorescent Penetrants to Detect Fatigue Cracks in Aluminum

NASA Technical Reports Server (NTRS)

Parker, Bradford, H.

2009-01-01

Historically both sensitivity level 3 and sensitivity level 4 fluorescent penetrants have been used to perform NASA Standard Level inspections of aerospace hardware. In April 2008, NASA-STD-5009 established a requirement that only sensitivity level 4 penetrants were acceptable for inspections of NASA hardware. Having NASA contractors change existing processes or perform demonstration tests to certify sensitivity level 3 penetrants posed a potentially huge cost to the Agency. This study was conducted to directly compare the probability of detection sensitivity level 3 and level 4 penetrants using both Method A and Method D inspection processes. The study results strongly support the conclusion that sensitivity level 3 penetrants are acceptable for NASA Standard Level inspections

Stability of Two Antifungal Agents, Fluconazole and Miconazole, Compounded in HUMCO RECURA Topical Cream to Determine Beyond-Use Date.

PubMed

Gautam, Pradeep; Light, Bob; Purvis, Troy

2017-01-01

A novel compounding vehicle (RECURA) has previously been proven to penetrate the nail bed when compounded with the antifungal agent miconazole or fluconazole, providing for an effective treatment for onychomycosis. In this study, miconazole and fluconazole were compounded separately in RECURA compounding cream, and they were tested at different time points (0, 7, 14, 28, 45, 60, 90, and 180 days) to determine the beyond-use date of those formulations. The beyond-use date testing of both formulations (10% miconazole in RECURA and 10% fluconazole in RECURA) proved them to be physically, chemically, and microbiologically stable under International Conference of Harmonisation controlled room temperature (25°C ± 2°C/60% RH ±5%) for at least 180 days from the date of compounding. Stability-indicating analytical method validation was completed for the simultaneous determination of miconazole and fluconazole in RECURA base using high-performance liquid chromatography coupled with photodiode array detector prior to the study. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Development of superconducting magnetic bearing using superconducting coil and bulk superconductor

NASA Astrophysics Data System (ADS)

Seino, H.; Nagashima, K.; Arai, Y.

2008-02-01

The authors conducted a study on superconducting magnetic bearing, which consists of superconducting rotor and stator to apply the flywheel energy-storage system for railways. In this study, high temperature bulk superconductor (HTS bulk) was combined with superconducting coils to increase the load capacity of the bearing. In the first step of the study, the thrust rolling bearing was selected for application by using liquid nitrogen cooled HTS bulk. 60mm-diameter HTS bulks and superconducting coil which generated a high gradient of magnetic field by cusp field were adopted as a rotor and a stator for superconducting magnetic bearing, respectively. The results of the static load test and the rotation test, creep of the electromagnetic forces caused by static flux penetration and AC loss due to eccentric rotation were decreased to the level without any problems in substantial use by using two HTS bulks. In the result of verification of static load capacity, levitation force (thrust load) of 8900N or more was supportable, and stable static load capacity was obtainable when weight of 460kg was levitated.

Effect of photodynamic therapy and non-thermal plasma on root canal filling: analysis of adhesion and sealer penetration

PubMed Central

MENEZES, Marilia; PRADO, Maíra; GOMES, Brenda; GUSMAN, Heloisa; SIMÃO, Renata

2017-01-01

Abstract Objective The aim of this study was to evaluate the effect of photodynamic therapy (PDT) and non-thermal plasma (NTP) on adhesion and sealer penetration in root canals. Material and Methods Sixty single-rooted premolars were used. The teeth were prepared using a crown-down technique. NaOCl and EDTA were used for irrigation and smear layer removal, respectively. The root canals were divided into three groups: control, PDT, and NTP. After treatments, the roots were filled using gutta-percha and either AH Plus (AHP) or MTA Fillapex (MTAF) sealers. Samples were sectioned at 4, 8, and 12 mm from the apex (1-mm slices)and analyzed by the push-out bond strength test (adhesion) and confocal laser scanning microscopy (sealer penetration). Data were statistically evaluated using Kruskal-Wallis, Dunn’s, and Spearman’s tests. Results Regarding AHP, bond strength was similar in the NTP group and in the control group, but significantly lower in the PDT group. As to MTAF, both therapies showed lower values than the control group. In the confocal analysis of AHP, maximum and mean penetration, and penetrated area were statistically higher in the control group than in the PDT and NTP groups. Penetrated perimeter was similar among groups. Regarding MTAF, all parameters yielded better results in the NTP than in the control group. The PDT and control groups showed similar results except for penetrated area. Conclusion PDT and plasma therapy affected the adhesion and sealer penetration of root canals filled with AH Plus and MTA Fillapex and there is no positive correlation between adhesion and sealer penetration. PMID:28877278

A scanning electron microscopic evaluation of in vitro dentinal tubules penetration by selected anaerobic bacteria.

PubMed

Siqueira, J F; De Uzeda, M; Fonseca, M E

1996-06-01

In vitro root canal dentinal tubule invasion by selected anaerobic bacteria commonly isolated from endodontic infections was evaluated. Dentinal cylinders obtained from bovine incisors were inoculated with bacteria, and microbial penetration into tubules was demonstrated by scanning electron microscopy. The results indicated that all bacterial strains tested were able to penetrate into dentinal tubules, but to different extents.

Geophysical-log and hydraulic-test analyses of groundwater-production wells at the Hannahville Indian Community, Menominee County, Michigan

USGS Publications Warehouse

Bayless, E. Randall; Anderson, J. Alton; Lampe, David C.; Williams, John H.

2013-01-01

The U.S. Geological Survey, in cooperation with the Hannahville Indian Community, evaluated the geohydrology of the bedrock formations and hydraulic properties of groundwater-production wells at the Hannahville Indian Community in Menominee County, Michigan. Geophysical logs were collected from five wells at two sites during September 2012. The logs were analyzed to characterize the lithostratigraphy, bedding and fractures, and hydraulic properties of the geologic formations and aquifers beneath the Hannahville Indian Community. The geophysical logs collected included natural gamma radiation, electromagnetic conductivity, wellbore image, caliper, ambient and stressed flowmeter, fluid resistivity, temperature, and wellbore deviation. The geophysical logs were analyzed with results from short-term hydraulic tests to estimate the transmissivity and water-level altitudes of flow zones penetrated by the wells. The geophysical log analysis indicated the wells penetrated four distinct lithostratigraphic units—shale and carbonate rock, upper carbonate rock, carbonate rock and glauconitic sandstone, and lower carbonate rock. Most of the fractures penetrated by the wellbores appeared to be related bedding partings. The lower carbonate rock unit contained solution features. Analysis of the geophysical logs and hydraulic tests indicated that each of the five wells penetrated from one to four flow zones. The Casino 5 well penetrated a flow zone that was associated with solution features and had an estimated total transmissivity of 4,280 feet squared per day (ft2/d), the highest estimate for all the wells. The Casino 3 well penetrated four flow zones and had an estimated total transmissivity of 3,570 ft2/d. The flow zones penetrated in the lower carbonate rock unit by the Casino 3 and 5 wells were hydraulically connected. The Golf Shack well penetrated two flow zones and had an estimated total transmissivity of 40 ft2/d, the lowest estimate for all the wells. The Community 1 and Community 2 wells penetrated three and four flow zones, respectively, and had estimated total transmissivity values of 185 and 280 ft2/d, respectively.

Acoustically-Enhanced Direct Contact Vapor Bubble Condensation

NASA Astrophysics Data System (ADS)

Boziuk, Thomas; Smith, Marc; Glezer, Ari

2017-11-01

Rate-limited, direct contact vapor condensation of vapor bubbles that are formed by direct steam injection through a nozzle in a quiescent subcooled liquid bath is accelerated using ultrasonic (MHz-range) actuation. A submerged, low power actuator produces an acoustic beam whose radiation pressure deforms the liquid-vapor interface, leading to the formation of a liquid spear that penetrates the vapor bubble to form a vapor torus with a significantly larger surface area and condensation rate. Ultrasonic focusing along the spear leads to the ejection of small, subcooled droplets through the vapor volume that impact the vapor-liquid interface and further enhance the condensation. High-speed Schlieren imaging of the formation and collapse of the vapor bubbles in the absence and presence of actuation shows that the impulse associated with the collapse of the toroidal volume leads to the formation of a turbulent vortex ring in the liquid phase. Liquid motions near the condensing vapor volume are investigated in the absence and presence of acoustic actuation using high-magnification PIV and show the evolution of a liquid jet through the center of the condensing toroidal volume and the formation and advection of vortex ring structures whose impulse appear to increase with temperature difference between the liquid and vapor phases. High-speed image processing is used to assess the effect of the actuation on the temporal and spatial variations in the characteristic scales and condensation rates of the vapor bubbles.

Ground Penetrating Radar : Pavement Layer Thickness Evaluation

DOT National Transportation Integrated Search

2003-12-01

The following report demonstrates the accuracy of using Ground Penetrating Radar (GPR) to determine both the surface layer thickness for asphalt, and concrete pavements. In addition tests were conducted to identify GPR's repeatability on dry pavement...

Ground penetrating radar, pavement layer thickness evaluation

DOT National Transportation Integrated Search

2002-12-01

The following report demonstrates the accuracy of using Ground Penetrating Radar (GPR) to determine both the surface layer thickness for asphalt, and concrete pavements. In addition tests were conducted to identify GPR's repeatability on dry pavement...

Ground Penetrating Radar : Pavement Layer Thickness Evaluation

DOT National Transportation Integrated Search

2002-12-01

The following report demonstrates the accuracy of using Ground Penetrating Radar (GPR) to determine both the surface layer thickness for asphalt, and concrete pavements. In addition tests were conducted to identify GPR's repeatability on dry pavement...

MEMS for medical technology applications

NASA Astrophysics Data System (ADS)

Frisk, Thomas; Roxhed, Niclas; Stemme, Göran

2007-01-01

This paper gives an in-depth description of two recent projects at the Royal Institute of Technology (KTH) which utilize MEMS and microsystem technology for realization of components intended for specific applications in medical technology and diagnostic instrumentation. By novel use of the DRIE fabrication technology we have developed side-opened out-of-plane silicon microneedles intended for use in transdermal drug delivery applications. The side opening reduces clogging probability during penetration into the skin and increases the up-take area of the liquid in the tissue. These microneedles offer about 200µm deep and pain-free skin penetration. We have been able to combine the microneedle chip with an electrically and heat controlled liquid actuator device where expandable microspheres are used to push doses of drug liquids into the skin. The entire unit is made of low cost materials in the form of a square one cm-sized patch. Finally, the design, fabrication and evaluation of an integrated miniaturized Quartz Crystal Microbalance (QCM) based "electronic nose" microsystem for detection of narcotics is described. The work integrates a novel environment-to-chip sample interface with the sensor element. The choice of multifunctional materials and the geometric features of a four-component microsystem allow a functional integration of a QCM crystal, electrical contacts, fluidic contacts and a sample interface in a single system with minimal assembly effort, a potential for low-cost manufacturing, and a few orders of magnitude reduced in system size (12*12*4 mm 3) and weight compared to commercially available instruments. The sensor chip was successfully used it for the detection of 200 ng of narcotics sample.

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

PCR-Based Method for Detecting Viral Penetration of Medical Exam Gloves

PubMed Central

Broyles, John M.; O'Connell, Kevin P.; Korniewicz, Denise M.

2002-01-01

The test approved by the U.S. Food and Drug Administration for assessment of the barrier quality of medical exam gloves includes visual inspection and a water leak test. Neither method tests directly the ability of gloves to prevent penetration by microorganisms. Methods that use microorganisms (viruses and bacteria) to test gloves have been developed but require classical culturing of the organism to detect it. We have developed a PCR assay for bacteriophage φX174 that allows the rapid detection of penetration of gloves by this virus. The method is suitable for use with both latex and synthetic gloves. The presence of glove powder on either latex or synthetic gloves had no effect on the ability of the PCR assay to detect bacteriophage DNA. The assay is rapid, sensitive, and inexpensive; requires only small sample volumes; and can be automated. PMID:12149320

The Penetration Behavior of an Annular Gas-Solid Jet Impinging on a Liquid Bath: The Effects of the Density and Size of Solid Particles

NASA Astrophysics Data System (ADS)

Chang, J. S.; Sohn, H. Y.

2012-08-01

Top-blow injection of a gas-solid jet through a circular lance is used in the Mitsubishi Continuous Smelting Process. One problem associated with this injection is the severe erosion of the hearth refractory below the lances. A new configuration of the lance to form an annular gas-solid jet rather than the circular jet was designed in this laboratory. With this new configuration, the solid particles fed through the center tube leave the lance at a much lower velocity than the gas, and the penetration behavior of the jet is significantly different from that with a circular lance where the solid particles leave the lance at the same high velocity as the gas. In previous cold-model investigations in this laboratory, the effects of the gas velocity, particle feed rate, lance height of the annular lance, and the cross-sectional area of the gas jet were studied and compared with the circular lance. This study examined the effect of the density and size of the solid particles on the penetration behavior of the annular gas-solid jet, which yielded some unexpected results. The variation in the penetration depth with the density of the solid particles at the same mass feed rate was opposite for the circular lance and the annular lance. In the case of the circular lance, the penetration depth became shallower as the density of the solid particles increased; on the contrary, for the annular lance, the penetration depth became deeper with the increasing density of particles. However, at the same volumetric feed rate of the particles, the density effect was small for the circular lance, but for the annular lance, the jets with higher density particles penetrated more deeply. The variation in the penetration depth with the particle diameter was also different for the circular and the annular lances. With the circular lance, the penetration depth became deeper as the particle size decreased for all the feed rates, but with the annular lance, the effect of the particle size was small. The overall results including the previous work indicated that the penetration behavior of an annular jet is much less sensitive to the variations in operating variables than that of a circular jet. Correlation equations for the penetration depth that show good agreements with the measured values have been developed.

Cone penetration tests and soil borings at the Mason Road site in Green Valley, Solano County, California

USGS Publications Warehouse

Bennett, Michael J.; Noce, Thomas E.; Lienkaemper, James J.

2011-01-01

In support of a study to investigate the history of the Green Valley Fault, 13 cone penetration test soundings and 3 auger borings were made at the Mason Road site in Green Valley, Solano County, California. Three borings were made at or near two of the cone penetration test soundings. The soils are mostly clayey with a few sandy layers or lenses. Fine-grained soils range from low plasticity sandy lean clay to very plastic fat clay. Lack of stratigraphic correlation in the subsurface prevented us from determining whether any channels had been offset at this site. Because the soils are generally very clayey and few sand layers or lenses are loose, the liquefaction potential at the site is very low.

Simple amides of oleanolic acid as effective penetration enhancers.

PubMed

Bednarczyk-Cwynar, Barbara; Partyka, Danuta; Zaprutko, Lucjusz

2015-01-01

Transdermal transport is now becoming one of the most convenient and safe pathways for drug delivery. In some cases it is necessary to use skin penetration enhancers in order to allow for the transdermal transport of drugs that are otherwise insufficiently skin-permeable. A series of oleanolic acid amides as potential transdermal penetration enhancers was formed by multistep synthesis and the synthesis of all newly prepared compounds is presented. The synthetized amides of oleanolic acid were tested for their in vitro penetration promoter activity. The above activity was evaluated by means of using the Fürst method. The relationships between the chemical structure of the studied compounds and penetration activity are presented.

Simple Amides of Oleanolic Acid as Effective Penetration Enhancers

PubMed Central

Bednarczyk-Cwynar, Barbara; Partyka, Danuta; Zaprutko, Lucjusz

2015-01-01

Transdermal transport is now becoming one of the most convenient and safe pathways for drug delivery. In some cases it is necessary to use skin penetration enhancers in order to allow for the transdermal transport of drugs that are otherwise insufficiently skin-permeable. A series of oleanolic acid amides as potential transdermal penetration enhancers was formed by multistep synthesis and the synthesis of all newly prepared compounds is presented. The synthetized amides of oleanolic acid were tested for their in vitro penetration promoter activity. The above activity was evaluated by means of using the Fürst method. The relationships between the chemical structure of the studied compounds and penetration activity are presented. PMID:26010090

Distribution Assessments of Coumarins from Angelicae Pubescentis Radix in Rat Cerebrospinal Fluid and Brain by Liquid Chromatography Tandem Mass Spectrometry Analysis.

PubMed

Yang, Yan-Fang; Zhang, Lei; Yang, Xiu-Wei

2018-01-20

Angelicae Pubescentis Radix (APR) is a widely-used traditional Chinese medicine. Pharmacological studies have begun to probe its biological activities on neurological disorders recently. To assess the brain penetration and distribution of APR, a validated ultra-performance liquid chromatography tandem mass spectrometry method was applied to the simultaneous determinations of the main coumarins from APR in the rat cerebrospinal fluid (CSF) and brain after oral administration of APR extract, including psoralen, xanthotoxin, bergapten, isoimperatorin, columbianetin, columbianetin acetate, columbianadin, oxypeucedanin hydrate, angelol B, osthole, meranzin hydrate and nodakenetin. Most of the tested coumarins entered the rat CSF and brain quickly, and double-peak phenomena in concentration-time curves were similar to those of their plasma pharmacokinetics. Columbianetin had the highest concentration in the CSF and brain, while psoralen and columbianetin acetate had the largest percent of CSF/plasma and brain/plasma, indicating that these three coumarins may be worthy of further research on the possible nervous effects. Correlations between the in vivo brain distributions and plasma pharmacokinetics of these coumarins were well verified. These results provided valuable information for the overall in vivo brain distribution characteristics of APR and also for its further studies on the active substances for the central nervous system.

A potential carrier based on liquid crystal nanoparticles for ophthalmic delivery of pilocarpine nitrate.

PubMed

Li, Jing; Wu, Lin; Wu, Weijun; Wang, Baoyan; Wang, Zhongyuan; Xin, Hongliang; Xu, Qunwei

2013-10-15

Poor corneal penetration and short preocular retention of a clinical hydrophilic drug, pilocarpine nitrate (PN), for the treatment of open-angle glaucoma and acute angle-closure glaucoma, limit its ocular application. The purpose of this study was to investigate the potential of liquid crystal nanoparticles (LCNPs) for ocular delivery of PN. LCNPs were developed by a top-down method using glyceryl monoolein (GMO) and water in the presence of stabilizer Poloxamer 407. They were characterized by transmission electron microscopy (TEM) and small angle X-ray diffraction (SAXS). The size of LCNP is 202.28±19.32 nm and the encapsulation efficiency reached 61.03%. The in vitro release profiles indicated that PN could keep sustained release from PN-loaded LCNPs for 8h. An ex vivo corneal permeation study revealed that the apparent permeability coefficient of PN-loaded LCNPs was 2.05-fold higher than that of commercial eye drops. In addition, the topical administration test showed that PN-loaded LCNPs had a prolonged effect on decreasing intraocular pressure (IOP) of rabbits compared with commercial drug and physiological saline. In conclusion, LCNPs had been demonstrated to be potential for controlled-release ocular drug delivery. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of a spectro-electrochemical cell for soft X-ray photon-in photon-out spectroscopy

NASA Astrophysics Data System (ADS)

Ishihara, Tomoko; Tokushima, Takashi; Horikawa, Yuka; Kato, Masaru; Yagi, Ichizo

2017-10-01

We developed a spectro-electrochemical cell for X-ray absorption and X-ray emission spectroscopy, which are element-specific methods to study local electronic structures in the soft X-ray region. In the usual electrochemical measurement setup, the electrode is placed in solution, and the surface/interface region of the electrode is not normally accessible by soft X-rays that have low penetration depth in liquids. To realize soft X-ray observation of electrochemical reactions, a 15-nm-thick Pt layer was deposited on a 150-nm-thick film window with an adhesive 3-nm-thick Ti layer for use as both the working electrode and the separator window between vacuum and a sample liquid under atmospheric pressure. The designed three-electrode electrochemical cell consists of a Pt film on a SiC window, a platinized Pt wire, and a commercial Ag|AgCl electrode as the working, counter, and reference electrodes, respectively. The functionality of the cell was tested by cyclic voltammetry and X-ray absorption and emission spectroscopy. As a demonstration, the electroplating of Pb on the Pt/SiC membrane window was measured by X-ray absorption and real-time monitoring of fluorescence intensity at the O 1s excitation.

Antibacterial activities of fluorescent nano assembled triphenylamine phosphonium ionic liquids.

PubMed

Brunel, Frédéric; Lautard, Christelle; Garzino, Frédéric; Giorgio, Suzanne; Raimundo, Jean M; Bolla, Jean M; Camplo, Michel

2016-08-01

Staphylococcus aureus, a Gram positive coccal bacterium is a major cause of nosocomial infection. We report the synthesis of new triphenylamine phosphonium ionic liquids which are able to self-assemble into multiwall nanoassemblies and to reveal a strong bactericidal activity (MIC=0.5mg/L) for Gram positive bacteria (including resistant strains) comparable to that of standard antibiotics. Time kill, metabolism and fluorescence confocal microscopy studies show a quasi-instantaneously penetration of the nanoassemblies inside the bacteria resulting of a rapid blocking (30min) of their proliferation. As confirmed by rezasurin reduction monitoring, these compounds strongly affect the bacterial metabolism and a Gram positive versus Gram negative selectivity is clearly observed. These fluorescent phosphonium ionic liquid might constitute a useful tool for both translocation studies and to tackle infectious diseases related to the field of implantology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microwave hydrology: A trilogy

NASA Technical Reports Server (NTRS)

Stacey, J. M.; Johnston, E. J.; Girard, M. A.; Regusters, H. A.

1985-01-01

Microwave hydrology, as the term in construed in this trilogy, deals with the investigation of important hydrological features on the Earth's surface as they are remotely, and passively, sensed by orbiting microwave receivers. Microwave wavelengths penetrate clouds, foliage, ground cover, and soil, in varying degrees, and reveal the occurrence of standing liquid water on and beneath the surface. The manifestation of liquid water appearing on or near the surface is reported by a microwave receiver as a signal with a low flux level, or, equivalently, a cold temperature. Actually, the surface of the liquid water reflects the low flux level from the cosmic background into the input terminals of the receiver. This trilogy describes and shows by microwave flux images: the hydrological features that sustain Lake Baykal as an extraordinary freshwater resource; manifestations of subsurface water in Iran; and the major water features of the Congo Basin, a rain forest.

Drop Impingement on Highly Wetting Micro/Nano Porous Surfaces

NASA Astrophysics Data System (ADS)

Buie, Cullen; Joung, Youngsoo

2011-11-01

Recently, we developed a novel fabrication method using a combination of electrophoretic deposition (EPD) and break down anodization (BDA) to achieve highly wetting nanoporous surfaces with microscale features. In this study we investigate droplet impingement behavior on these surfaces as a function of impact velocity, droplet size, and liquid properties. We observe impingement modes we denote as ``necking'' (droplet breaks before full penetration in the porous surface), ``spreading'' (continuous wicking into the porous surface), and ``jetting'' (jets of liquid emanate from the edges of the wicking liquid). To predict the droplet impingement modes, we've developed a non-dimensional parameter that is a function of droplet velocity, dynamic viscosity, effective pore radius and contact angle. The novel dimensionless parameter successfully predicts drop impingement modes across multiple fluids. Results of this study will inform the design of spray impingement cooling systems for electronics applications where the ``spreading'' mode is preferred.

Micro-column plasma emission liquid chromatograph

DOEpatents

Gay, Don D.

1984-01-01

In a direct current plasma emission spectrometer for use in combination with a micro-column liquid chromatograph, an improved plasma source unit. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

Micro-column plasma emission liquid chromatograph. [Patent application

DOEpatents

Gay, D.D.

1982-08-12

In a direct current plasma emission spectrometer for use in combination with a microcolumn liquid chromatograph, an improved plasma source unit is claimed. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

On the nonlinear dynamics of trolling-mode AFM: Analytical solution using multiple time scales method

NASA Astrophysics Data System (ADS)

Sajjadi, Mohammadreza; Pishkenari, Hossein Nejat; Vossoughi, Gholamreza

2018-06-01

Trolling mode atomic force microscopy (TR-AFM) has resolved many imaging problems by a considerable reduction of the liquid-resonator interaction forces in liquid environments. The present study develops a nonlinear model of the meniscus force exerted to the nanoneedle of TR-AFM and presents an analytical solution to the distributed-parameter model of TR-AFM resonator utilizing multiple time scales (MTS) method. Based on the developed analytical solution, the frequency-response curves of the resonator operation in air and liquid (for different penetration length of the nanoneedle) are obtained. The closed-form analytical solution and the frequency-response curves are validated by the comparison with both the finite element solution of the main partial differential equations and the experimental observations. The effect of excitation angle of the resonator on horizontal oscillation of the probe tip and the effect of different parameters on the frequency-response of the system are investigated.

Structural signal of a dynamic glass transition

NASA Astrophysics Data System (ADS)

Chattopadhyay, Sudeshna; Uysal, Ahmet; Stripe, Benjamin; Evmenenko, Guennadi; Dutta, Pulak; Ehrlich, Steven; Karapetrova, Evguenia A.

2010-03-01

Conventional wisdom states that there is no significant difference between the static structures of the glass and liquid states of a given material. Using x-ray reflectivity, we have studied pentaphenyl trimethyl trisiloxane, an isotropic liquid at room temperature with a dynamic glass transition at 224K. Surface density oscillations (surface layers) develop below 285K, similar to those seen in other metallic and dielectric liquids and in computer simulations [1]. Upon cooling further, there is a sharp increase in the penetration of the surface layers into the bulk material, i.e. an apparently discontinuous change in the static structure, exactly at the glass transition (224K) [2]. [4pt] [1]. e.g. O. M. Magnussen et al., PRL 74, 4444 (1995); H. Mo et al. PRL 96, 096107 (2006); E. Chac'on et al., PRL 87, 166101 (2001) [0pt] [2] S. Chattopadhyay et al, PRL 103, 175701 (2009)

Cyclic Polarization Behavior of ASTM A537-Cl.1 Steel in the Vapor Space Above Simulated Waste

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

Wiersma, B

2004-11-01

An assessment of the potential degradation mechanisms of Types I and II High-Level Waste (HLW) Tanks determined that pitting corrosion and stress corrosion cracking were the two most significant degradation mechanisms. Specifically, nitrate induced stress corrosion cracking was determined to be the principal degradation mechanism for the primary tank steel of non-stress relieved tanks. Controls on the solution chemistry have been in place to preclude the initiation and propagation of degradation in the tanks. However, recent experience has shown that steel not in contact with the bulk waste solution or slurry, but exposed to the ''vapor space'' above the bulkmore » waste, may be vulnerable to the initiation and propagation of degradation, including pitting and stress corrosion cracking. A program to resolve the issues associated with potential vapor space corrosion is in place. The objective of the program is to develop understanding of vapor space (VSC) and liquid/air interface (LAIC) corrosion to ensure a defensible technical basis to provide accurate corrosion evaluations with regard to vapor space and liquid/air interface corrosion (similar to current evaluations). There are several needs for a technically defensible basis with sufficient understanding to perform these evaluations. These include understanding of the (1) surface chemistry evolution, (2) corrosion response through coupon testing, and (3) mechanistic understanding through electrochemical studies. Experimentation performed in FY02 determined the potential for vapor space and liquid/air interface corrosion of ASTM A285-70 and ASTM A537-Cl.1 steels. The material surface characteristics, i.e. mill-scale, polished, were found to play a key role in the pitting response. The experimentation indicated that the potential for limited vapor space and liquid/air interface pitting exists at 1.5M nitrate solution when using chemistry controls designed to prevent stress corrosion cracking. Experimentation performed in FY03 quantified pitting rates as a function of material surface characteristics, including mill-scale and defects within the mill-scale. Testing was performed on ASTM A537-Cl.1 (normalized) steel, the material of construction of the Type III HLW tanks. The pitting rates were approximately 3 mpy for exposure above inhibited solutions, as calculated from the limited exposure times. This translates to a penetration time of 166 years for a 0.5-in tank wall provided that the pitting rate remains constant and the bulk solution chemistry is maintained within the L3 limit. The FY04 testing consisted of electrochemical testing to potentially lend insight into the surface chemistry and further understand the corrosion mechanism in the vapor space. Electrochemical testing lends insight into the corrosion processes through the determination of current potential relationships. The results of the electrochemical testing performed during FY04 are presented here.« less

Using portable particle sizing instrumentation to rapidly measure the penetration of fine and ultrafine particles in unoccupied residences.

PubMed

Zhao, H; Stephens, B

2017-01-01

Much of human exposure to particulate matter of outdoor origin occurs inside buildings, particularly in residences. The particle penetration factor through leaks in a building's exterior enclosure assembly is a key parameter that governs the infiltration of outdoor particles. However, experimental data for size-resolved particle penetration factors in real buildings, as well as penetration factors for fine particles less than 2.5 μm (PM 2.5 ) and ultrafine particles less than 100 nm (UFPs), remain limited, in part because of previous limitations in instrumentation and experimental methods. Here, we report on the development and application of a modified test method that utilizes portable particle sizing instrumentation to measure size-resolved infiltration factors and envelope penetration factors for 0.01-2.5 μm particles, which are then used to estimate penetration factors for integral measures of UFPs and PM 2.5 . Eleven replicate measurements were made in an unoccupied apartment unit in Chicago, IL to evaluate the accuracy and repeatability of the test procedure and solution methods. Mean estimates of size-resolved penetration factors ranged from 0.41 ± 0.14 to 0.73 ± 0.05 across the range of measured particle sizes, while mean estimates of penetration factors for integral measures of UFPs and PM 2.5 were 0.67 ± 0.05 and 0.73 ± 0.05, respectively. Average relative uncertainties for all particle sizes/classes were less than 20%. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Application of direct-reading and elemental carbon analysis methods to measure mass-based penetration of carbon nanotubes through elastomeric half-face and filtering facepiece respirators.

PubMed

Vo, Evanly; Zhuang, Ziqing; Birch, Eileen; Birch, Quinn

2016-01-01

The aim of this study was to apply a direct-reading aerosol instrument method and an elemental carbon (EC) analysis method to measure the mass-based penetration of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) through elastomeric half-mask respirators (EHRs) and filtering facepiece respirators (FFRs). For the direct-reading aerosol instrument method, two scanning mobility particle sizer/aerodynamic particle sizer systems were used to simultaneously determine the upstream (outside respirator) and downstream (inside respirator) test aerosols. For the EC analysis method, upstream and downstream CNTs were collected on filter cassettes and then analyzed using a thermal-optical technique. CNT mass penetrations were found in both methods to be within the associated efficiency requirements for each type and class of the respirator models that were tested. Generally, the penetrations of SWCNTs and MWCNTs had a similar trend with penetration being the highest for the N95 EHRs, followed by N95 FFRs, P100 EHRs, and P100 FFRs. This trend held true for both methods; however, the CNT penetration determined by the direct-reading aerosol instrument method (0.009-1.09% for SWCNTs and 0.005-0.21% for MWCNTs) was greater relative to the penetration values found through EC analysis method (0.007-0.69% for SWCNTs and 0.004-0.13% for MWCNTs). The results of this study illustrate considerations for how the methods can be used to evaluate penetration of morphologically complex materials through FFRs and EHRs.

The relationship between mechanical properties and ballistic penetration depth in a viscoelastic gel.

PubMed

Mrozek, Randy A; Leighliter, Brad; Gold, Christopher S; Beringer, Ian R; Yu, Jian H; VanLandingham, Mark R; Moy, Paul; Foster, Mark H; Lenhart, Joseph L

2015-04-01

The fundamental material response of a viscoelastic material when impacted by a ballistic projectile has important implication for the defense, law enforcement, and medical communities particularly for the evaluation of protective systems. In this paper, we systematically vary the modulus and toughness of a synthetic polymer gel to determine their respective influence on the velocity-dependent penetration of a spherical projectile. The polymer gels were characterized using tensile, compression, and rheological testing taking special care to address the unique challenges associated with obtaining high fidelity mechanical data on highly conformal materials. The depth of penetration data was accurately described using the elastic Froude number for viscoelastic gels ranging in Young's modulus from ~60 to 630 kPa. The minimum velocity of penetration was determined to scale with the gel toughness divided by the gel modulus, a qualitative estimate for the zone of deformation size scale upon impact. We anticipate that this work will provide insight into the critical material factors that control ballistic penetration behavior in soft materials and aid in the design and development of new ballistic testing media. Published by Elsevier Ltd.

Minimum velocity necessary for nonconventional projectiles to penetrate the eye: an experimental study using pig eyes.

PubMed

Marshall, John W; Dahlstrom, Dean B; Powley, Kramer D

2011-06-01

To satisfy the Criminal Code of Canada's definition of a firearm, a barreled weapon must be capable of causing serious bodily injury or death to a person. Canadian courts have accepted the forensically established criteria of "penetration or rupture of an eye" as serious bodily injury. The minimal velocity of nonconventional ammunition required to penetrate the eye including airsoft projectiles has yet to be established. To establish minimal threshold requirements for eye penetration, empirical tests were conducted using a variety of airsoft projectiles. Using the data obtained from these tests, and previous research using "air gun" projectiles, an "energy density" parameter was calculated for the minimum penetration threshold of an eye. Airsoft guns capable of achieving velocities in excess of 99 m/s (325 ft/s) using conventional 6-mm airsoft ammunition will satisfy the forensically established criteria of "serious bodily injury." The energy density parameter for typical 6-mm plastic airsoft projectiles is 4.3 to 4.8 J/cm². This calculation also encompasses 4.5-mm steel BBs.

Analytical Solution for Flow to a Partially Penetrating Well with Storage in a Confined Aquifer

NASA Astrophysics Data System (ADS)

Vesselinov, V. V.; Mishra, P. K.; Neuman, S. P.

2009-12-01

Analytical solutions for radial flow toward a pumping well are commonly applied to analyze pumping tests conducted in confined aquifers. However, the existing analytical solutions are not capable to simultaneously take into account aquifer anisotropy, partial penetration, and wellbore storage capacity of pumping well. Ignoring these effects may have important impact on the estimated aquifer properties. We present a new analytical solution for three-dimensional, axially symmetric flow to a pumping well in confined aquifer that accouts for aquifer anisotropy, partial penetration and wellbore storage capacity of pumping well. Our analytical reduces to that of Papadopulos et.al. [1967] when the pumping well is fully penetrating, Hantush [1964] when the pumping well has no wellbore storage, and Theis [1935] when both conditions are fulfilled. The solution is evaluated through numerical inversion of its Laplace transform. We use our new solution to analyze data from synthetic and real pumping tests.

Tracking Internal Temperature and Structural Dynamics during Nail Penetration of Lithium-Ion Cells

DOE PAGES

Finegan, Donal P.; Tjaden, Bernhard; M. M. Heenan, Thomas; ...

2017-10-31

Mechanical abuse of lithium-ion batteries is widely used during testing to induce thermal runaway, characterize associated risks, and expose cell and module vulnerabilities. But, the repeatability of puncture or 'nail penetration' tests is a key issue as there is often a high degree of variability in the resulting thermal runaway process. Here, the failure mechanisms of 18650 cells punctured at different locations and orientations are characterized with respect to their internal structural degradation, and both their internal and surface temperature, all of which are monitored in real time. The initiation and propagation of thermal runaway is visualized via high-speed synchrotronmore » X-ray radiography at 2000 frames per second, and the surface and internal temperatures are recorded via infrared imaging and a thermocouple embedded in the tip of the penetrating nail, respectively. The influence of the nail, as well as how and where it penetrates the cell, on the initiation and propagation of thermal runaway is described and the suitability of this test method for representing in-field failures is discussed.« less

Penetration of rod projectiles in semi-infinite targets : a validation test for Eulerian X-FEM in ALEGRA.

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

Park, Byoung Yoon; Leavy, Richard Brian; Niederhaus, John Henry J.

2013-03-01

The finite-element shock hydrodynamics code ALEGRA has recently been upgraded to include an X-FEM implementation in 2D for simulating impact, sliding, and release between materials in the Eulerian frame. For validation testing purposes, the problem of long-rod penetration in semi-infinite targets is considered in this report, at velocities of 500 to 3000 m/s. We describe testing simulations done using ALEGRA with and without the X-FEM capability, in order to verify its adequacy by showing X-FEM recovers the good results found with the standard ALEGRA formulation. The X-FEM results for depth of penetration differ from previously measured experimental data by lessmore » than 2%, and from the standard formulation results by less than 1%. They converge monotonically under mesh refinement at first order. Sensitivities to domain size and rear boundary condition are investigated and shown to be small. Aside from some simulation stability issues, X-FEM is found to produce good results for this classical impact and penetration problem.« less

NREL and SDG&E Collaboration to Support SDG&E Grid and Storage Efforts: Cooperative Research and Development Final Report, CRADA Number CRD-14-562

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

Baggu, Murali

2017-01-01

This project will enable effective utilization of high penetration of photovoltaics (PV) in islanded microgrids, increasing overall system efficiency, decreased fuel costs and resiliency of the overall system to help meet the SunShot goals of enhancing system integration methods to increase penetration of PV. National Renewable Energy Laboratory (NREL) will collaborate with San Diego Gas & Electric (SDG&E) to provide research and testing support to address their needs in energy storage sizing and placement, Integrated Test Facility (ITF) development, Real Time Digital Simulator (RTDS) Modeling and simulation support at ITF, Visualization and Virtual connection to Energy Systems Integration Facility (ESIF),more » and microgrid simulation and testing areas. Specifically in this project a real microgrid scenario with high penetration of PV (existing in SDG&E territory) is tested in the ESIF laboratory. Multiple control cases for firming PV using storage in a microgrid scenario will be investigated and tested in the laboratory setup.« less

Blood-brain barrier penetration of novel pyridinealdoxime methiodide (PAM)-type oximes examined by brain microdialysis with LC-MS/MS

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

Okuno, Sou; Sakurada, Koichi; Ohta, Hikoto

2008-02-15

To develop a new reactivator of inhibited acetylcholinesterase (AChE) that can easily penetrate the blood-brain barrier (BBB), BBB penetration of 6 known and novel pyridinealdoxime methiodide (PAM)-type oximes (alkylPAMs) with relatively high reactivation activities was examined by in vivo rat brain microdialysis with liquid chromatography-mass spectrometry (LC-MS/MS). The 50% lethal dose (LD{sub 50}) of alkylPAMs was intravenously determined for Wistar rats, then the limit of detection, quantification range and linearity of the calibration curve of the alkylPAMs in dialysate and blood were determined by LC-MS/MS. Following 10% LD{sub 50} intravenous administration of the alkylPAMs, 4-[(hydroxyimino) methyl]-1-(2-phenylethyl) pyridinium bromide (4-PAPE) andmore » 4-[(hydroxyimino) methyl]-1-octylpyridinium bromide (4-PAO) appeared in the dialysate. Striatal extracellular fluid/blood concentration ratios were 0.039 {+-} 0.018 and 0.301 {+-} 0.183 (mean {+-} SEM), respectively, 1 h after treatment. This is the first report of BBB penetration of 4-PAPE, and the concentration ratio was smaller than that of 2-PAM.The mean BBB penetration of 4-PAO was approximately 30%, indicating that intravenous administration of 4-PAO may be effective for the reactivation of blocked cholinesterase in the brain. However, the toxicity of 4-PAO (LD{sub 50}; 8.89 mg/kg) was greater than that of 2-PAM. Further investigation is required to determine the effects of these alkylPAMs in organophosphate poisoning.« less

Power MEMS Development

DTIC Science & Technology

2011-05-01

wafer pair through further processing. Initial cracking issues were identified due to liquid penetration between the wafers during wet processing...free-standing MCD films we needed to address crack formation in the diamond and the Si substrate, which we observed during our initial growths due to...NCD film grown using the heated stage, and finally the thick MCD film grown on the cooled stage. We also found that the control of cracking in the

Integration and Penetration Opportunities of Alternative Energy, Fuels, and Technologies within Military Systems, Logistics, and Operations

DTIC Science & Technology

2010-01-01

Emerging Biodiesel, Electricity, Ethanol, Hydrogen, Methanol, Natural Gas, Propane, Ultra-Low Sulfur Diesel Biobutanol, Biogas , Biomass-to- Liquids...Ethanol Corn grain (starch), sugar cane (sugar), (cellulosic) grass, wood, crop residues, newspapers Biogas Animal manure, sewage, and municipal...Electric 7 Radio Frequency 2 Biofuel 5 Electric 3 Nuclear 9 Waste 6 Biobutanol 3 Generators Wood Derived Fuels 5 Biogas 3 Petroleum

Exploration of bulk and interface behavior of gas molecules and 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid using equilibrium and nonequilibrium molecular dynamics simulation and quantum chemical calculation.

PubMed

Yang, Quan; Achenie, Luke E K

2018-04-18

Ionic liquids (ILs) show brilliant performance in separating gas impurities, but few researchers have performed an in-depth exploration of the bulk and interface behavior of penetrants and ILs thoroughly. In this research, we have performed a study on both molecular dynamics (MD) simulation and quantum chemical (QC) calculation to explore the transport of acetylene and ethylene in the bulk and interface regions of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]-[BF4]). The diffusivity, solubility and permeability of gas molecules in the bulk were researched with MD simulation first. The subdiffusion behavior of gas molecules is induced by coupling between the motion of gas molecules and the ions, and the relaxation processes of the ions after the disturbance caused by gas molecules. Then, QC calculation was performed to explore the optical geometry of ions, ion pairs and complexes of ions and penetrants, and interaction potential for pairs and complexes. Finally, nonequilibrium MD simulation was performed to explore the interface structure and properties of the IL-gas system and gas molecule behavior in the interface region. The research results may be used in the design of IL separation media.

Development of a new test system to determine penetration of multi-walled carbon nanotubes through filtering facepiece respirators

PubMed Central

Vo, Evanly; Zhuang, Ziqing

2015-01-01

Carbon nanotubes (CNTs) are currently used in numerous industrial and biomedical applications. Recent studies suggest that workers may be at risk of adverse health effects if they are exposed to CNTs. A National Institute for Occupational Safety and Health (NIOSH) survey of the carbonaceous nanomaterial industry found that 77% of the companies used respiratory protection. Elastomeric half-mask respirators and filtering facepiece respirators (FFRs) are commonly used. Although numerous respirator filtration studies have been done with surrogate engineered nanoparticles, such as sodium chloride, penetration data from engineered nanoparticles such as CNTs are lacking. The aims of this study were to develop a new CNT aerosol respirator testing system and to determine multi-walled CNT (MWCNT) penetration through FFRs. A custom-designed CNT aerosol respirator testing system (CNT-ARTS) was developed which was capable of producing a sufficient amount of airborne MWCNTs for testing of high efficiency FFRs. The size distribution of airborne MWCNTs was 20–10,000 nm, with 99% of the particles between 25 and 2840 nm. The count median diameter (CMD) was 209 nm with a geometric standard deviation (GSD) of 1.98. This particle size range is similar to those found in some work environments (particles ≤6000 nm). The penetration of MWCNTs through six tested FFR models at two constant flow rates of 30 and 85 LPM was determined. Penetration at 85 LPM (0.58–2.04% for N95, 0.15–0.32% for N99, and 0.007–0.009% for P100 FFRs) was greater compared with the values at 30 LPM (0.28–1.79% for N95, 0.10–0.24% for N99, and 0.005–0.006% for P100 FFRs). The most penetrating particle size through all six tested FFR models was found to be in the range of 25–130 nm and 35–200 nm for the 30-LPM and 85-LPM flow rates, respectively. PMID:26166842

Modeling of turbulence effects on the heat and mass transfer of evaporating sprays

NASA Astrophysics Data System (ADS)

Madhanabharatam, Balasubramanyam

A large diversity of two-phase gas-liquid flows of both scientific and practical interest involves the evaporation of near spherical liquid droplets in high temperature turbulent environments. Current numerical modeling approaches are predominantly focused towards the effects of continuous phase (gas phase) turbulence on the evaporation rates of liquid fuel sprays during the evaporation process, failing to account for the inherent turbulence present in the dispersed phase (liquid phase), due to the injection of sprays at high velocities. Existing models accounting for internal turbulence effects use Direct Numerical Simulations and Large Eddy Simulations that are computationally intensive. This research provides an alternative phenomenological approach of modeling droplet internal turbulence effects through the mass and heat transfer between the droplet surface and the external gas phase within a thin film inside the droplet. This finite conductivity (F-C) model was based on the two-temperature film theory, where the turbulence characteristics of the droplet are used to estimate the effective thermal diffusivity (alphaeff) within the droplet phase. The alphaeff is estimated from the physical properties of the flow within the droplet rather than from a 'curve-fit' as done conventionally. The results of the one-way coupled study indicated that the equilibrium drop temperature predictions were higher than calculations by the infinite conductivity (I-C) model. The liquid internal turbulence has a considerable effect on the diffusivity in the primary atomization regime. The thermal boundary layer was found to be substantially thick initially, decreasing quickly to a small value, exhibiting a reasonable physical trend. The two-way coupled studies (CFD) indicated that the F-C model, slowed down the evaporation process, produced larger droplets and longer tip penetration lengths during the initial stages of injection. For a jet in a supersonic cross-flow, results indicated that jet penetration increased rapidly in the vicinity of the injector exit and then gradually increased due to increase in the drag of the air stream. A modified drag coefficient was incorporated to improve model accuracy in predictions. Overall the results obtained from the numerical calculations during this study were reasonably comparable to measured data and showed more accurate comparisons to that of the I-C model.

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.

Testing Penetration of Epoxy Resin and Diamine Hardeners through Protective Glove and Clothing Materials.

PubMed

Henriks-Eckerman, Maj-Len; Mäkelä, Erja A; Suuronen, Katri

2015-10-01

Efficient, comfortable, yet affordable personal protective equipment (PPE) is needed to decrease the high incidence of allergic contact dermatitis arising from epoxy resin systems (ERSs) in industrial countries. The aim of this study was to find affordable, user-friendly glove and clothing materials that provide adequate skin protection against splashes and during the short contact with ERS that often occurs before full cure. We studied the penetration of epoxy resin and diamine hardeners through 12 glove or clothing materials using a newly developed test method. The tests were carried out with two ERS test mixtures that had a high content of epoxy resin and frequently used diamine hardeners of different molar masses. A drop (50 µl) of test mixture was placed on the outer surface of the glove/clothing material, which had a piece of Fixomull tape or Harmony protection sheet attached to the inner surface as the collection medium. The test times were 10 and 30 min. The collecting material was removed after the test was finished and immersed into acetone. The amounts of diglycidyl ether of bisphenol A (DGEBA), isophorone diamine (IPDA), and m-xylylenediamine (XDA) in the acetone solution were determined by gas chromatography with mass spectrometric detection. The limit for acceptable penetration of XDA, IPDA, and DGEBA through glove materials was set at 2 µg cm(-2). Penetration through the glove materials was 1.4 µg cm(-2) or less. The three tested chemical protective gloves showed no detectable penetration (<0.5 µg cm(-2)). Several affordable glove and clothing materials were found to provide adequate protection during short contact with ERS, in the form of, for example, disposable gloves or clothing materials suitable for aprons and as additional protective layers on the most exposed parts of clothing, such as the front of the legs and thighs and under the forearms. Every ERS combination in use should be tested separately to find the best skin protection material, and this can be done by using this simple test method. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

The effects of a xanthan gum-based thickener on the swallowing function of patients with dysphagia.

PubMed

Rofes, L; Arreola, V; Mukherjee, R; Swanson, J; Clavé, P

2014-05-01

Increasing bolus viscosity of thin liquids is a basic therapeutic strategy to protect patients with oropharyngeal dysphagia (OD) from aspiration. However, conventional starch thickeners increase post-deglutitive residue. To assess the therapeutic effect of a new xanthan gum-based thickener, Resource ThickenUp Clear (Nestlé Health Science, Vevey, Switzerland) on patients with oropharyngeal dysphagia. We studied the effect of Resource ThickenUp Clear using a clinical method and videofluoroscopy on 120 patients with oropharyngeal dysphagia (66 with stroke, 41 older and 13 with neurodegenerative diseases) and 14 healthy volunteers while swallowing thin-liquid, nectar-like and spoon-thick boluses. We assessed the prevalence of signs of impaired safety and efficacy of swallow and the physiology of the swallow response. Increasing bolus viscosity with Resource ThickenUp Clear: (i) improved safety of swallow demonstrated by a reduction in the prevalence of cough and voice changes in the clinical study and penetrations and aspirations during video fluoroscopy. Prevalence of aspirations was 12.7% with thin liquid, 7.7% with nectar-like (P < 0.01) and 3.4% with spoon-thick (P < 0.01) viscosities. Penetration-Aspiration Scale was reduced from 3.24 ± 0.18 at thin liquid to 2.20 ± 0.18 at nectar-like (P < 0.001) and to 1.53 ± 0.13 at spoon-thick (P < 0.001) viscosities; (ii) did not enhance pharyngeal residue; (iii) nectar-like viscosity did not affect bolus velocity nor timing of swallow response and (iv) spoon-thick viscosity reduced bolus velocity. Resource ThickenUp Clear improves the safety of swallow without increasing residue providing a viscosity-dependent therapeutic effect for patients with oropharyngeal dysphagia. At nectar viscosity, the effect is due to intrinsic texture properties, spoon-thick viscosity adding changes in swallow physiology. NCT01158313. © 2014 John Wiley & Sons Ltd.

Inspecting cracks in foam insulation

NASA Technical Reports Server (NTRS)

Cambell, L. W.; Jung, G. K.

1979-01-01

Dye solution indicates extent of cracking by penetrating crack and showing original crack depth clearly. Solution comprised of methylene blue in denatured ethyl alcohol penetrates cracks completely and evaporates quickly and is suitable technique for usage in environmental or structural tests.

Incorporation of liquid lipid in lipid nanoparticles for ocular drug delivery enhancement

NASA Astrophysics Data System (ADS)

Shen, Jie; Sun, Minjie; Ping, Qineng; Ying, Zhi; Liu, Wen

2010-01-01

The present work investigates the effect of liquid lipid incorporation on the physicochemical properties and ocular drug delivery enhancement of nanostructured lipid carriers (NLCs) and attempts to elucidate in vitro and in vivo the potential of NLCs for ocular drug delivery. The CyA-loaded or fluorescein-marked nanocarriers composed of Precifac ATO 5 and Miglyol 840 (as liquid lipid) were prepared by melting-emulsion technology, and the physicochemical properties of nanocarriers were determined. The uptake of nanocarriers by human corneal epithelia cell lines (SDHCEC) and rabbit cornea was examined. Ex vivo fluorescence imaging was used to investigate the ocular distribution of nanocarriers. The in vitro cytotoxicity and in vivo acute tolerance were evaluated. The higher drug loading capacity and improved in vitro sustained drug release behavior of lipid nanoparticles was found with the incorporation of liquid lipid in lipid nanoparticles. The uptake of nanocarriers by the SDHCEC was increased with the increase in liquid lipid loading. The ex vivo fluorescence imaging of the ocular tissues indicated that the liquid lipid incorporation could improve the ocular retention and penetration of ocular therapeutics. No alternation was macroscopically observed in vivo after ocular surface exposure to nanocarriers. These results indicated that NLC was a biocompatible and potential nanocarrier for ocular drug delivery enhancement.

Liquid Water Restricts Habitability in Extreme Deserts.

PubMed

Cockell, Charles S; Brown, Sarah; Landenmark, Hanna; Samuels, Toby; Siddall, Rebecca; Wadsworth, Jennifer

2017-04-01

Liquid water is a requirement for biochemistry, yet under some circumstances it is deleterious to life. Here, we show that liquid water reduces the upper temperature survival limit for two extremophilic photosynthetic microorganisms (Gloeocapsa and Chroococcidiopsis spp.) by greater than 40°C under hydrated conditions compared to desiccated conditions. Under hydrated conditions, thermal stress causes protein inactivation as shown by the fluorescein diacetate assay. The presence of water was also found to enhance the deleterious effects of freeze-thaw in Chroococcidiopsis sp. In the presence of water, short-wavelength UV radiation more effectively kills Gloeocapsa sp. colonies, which we hypothesize is caused by factors including the greater penetration of UV radiation into hydrated colonies compared to desiccated colonies. The data predict that deserts where maximum thermal stress or irradiation occurs in conjunction with the presence of liquid water may be less habitable to some organisms than more extreme arid deserts where organisms can dehydrate prior to being exposed to these extremes, thus minimizing thermal and radiation damage. Life in extreme deserts is poised between the deleterious effects of the presence and the lack of liquid water. Key Words: Deserts-Extremophiles-Stress-High temperatures-UV radiation-Desiccation. Astrobiology 17, 309-318.

Method for rigless zone abandonment using internally catalyzed resin system

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

Martin, R.C.

1980-02-19

A zone of a subterranean formation penetrated by a well bore is permanently plugged by injecting a liquid resin system containing at least one thermosetting resin and at least one curing agent or catalyst therefor into the formation and injecting into the wellbore following the resin system, a second liquid containing at least one chain stopping compound to react with one component in the resin system to prevent any of the resin system remaining in the well bore from crosslinking to a sufficient crosslink density to form a solid in the wellbore. Preferably, the second liquid also contains a fluidmore » loss additive to minimize loss of the second liquid from the wellbore to the formation. The method permits a zone to be plugged off and abandoned without the need to erect a drilling rig to drill out excess plugging material remaining in the wellbore. In a preferred embodiment, the resin system comprises the diglycidyl ether of bisphenol a and polymethylene phenylamine in ethylene glycol ethyl ether, and the preferred second liquid is monoethanolamine in ethylene glycol ethyl ether as a solvent with ethylcellulose and silic flour to control fluid loss.« less

Composition for preventing a resin system from setting up in a well bore

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

Martin, R. C.

1981-06-09

A zone of a subterranean formation penetrated by a well bore is permanently plugged by injecting a liquid resin system containing at least one thermosetting resin and at least one curing agent or catalyst therefor into the formation and injecting into the wellbore following the resin system, a second liquid containing at least one chain stopping compound to react with one component in the resin system to prevent any of the resin system remaining in the well bore from crosslinking to a sufficient crosslink density to form a solid in the wellbore. Preferably, the second liquid also contains a fluidmore » loss additive to minimize loss of the second liquid from the wellbore to the formation. The method permits a zone to be plugged off and abandoned without the need to erect a drilling rig to drill out excess plugging material remaining in the wellbore. In a preferred embodiment, the resin system comprises the diglycidyl ether of bisphenol a and polymethylene phenylamine in ethylene glycol ethyl ether, and the preferred second liquid is monoethanolamine in ethylene glycol ethyl ether as a solvent with ethylcellulose and silica flour to control fluid loss.« less

Afterlife of a Drop Impacting a Liquid Pool

NASA Astrophysics Data System (ADS)

Saha, Abhishek; Wei, Yanju; Tang, Xiaoyu; Law, Chung K.

2017-11-01

Drop impact on liquid pool is ubiquitous in industrial processes, such as inkjet printing and spray coating. While merging of drop with the impacted liquid surface is essential to facilitate the printing and coating processes, it is the afterlife of this merged drop and associated mixing which control the quality of the printed or coated surface. In this talk we will report an experimental study on the structural evolution of the merged droplet inside the liquid pool. First, we will analyze the depth of the crater created on the pool surface by the impacted drop for a range of impact inertia, and we will derive a scaling relation and the associated characteristic time-scale. Next, we will focus on the toroidal vortex formed by the moving drop inside the liquid pool and assess the characteristic time and length scales of the penetration process. The geometry of the vortex structure which qualitatively indicates the degree of mixedness will also be discussed. Finally, we will present the results from experiments with various viscosities to demonstrate the role of viscous dissipation on the geometry and structure formed by the drop. This work is supported by the Army Research Office and the Xerox Corporation.

Directional, passive liquid transport: the Texas horned lizard as a model for a biomimetic 'liquid diode'.

PubMed

Comanns, Philipp; Buchberger, Gerda; Buchsbaum, Andreas; Baumgartner, Richard; Kogler, Alexander; Bauer, Siegfried; Baumgartner, Werner

2015-08-06

Moisture-harvesting lizards such as the Texas horned lizard (Iguanidae: Phrynosoma cornutum) live in arid regions. Special skin adaptations enable them to access water sources such as moist sand and dew: their skin is capable of collecting and transporting water directionally by means of a capillary system between the scales. This fluid transport is passive, i.e. requires no external energy, and directs water preferentially towards the lizard's snout. We show that this phenomenon is based on geometric principles, namely on a periodic pattern of interconnected half-open capillary channels that narrow and widen. Following a biomimetic approach, we used these principles to develop a technical prototype design. Building upon the Young-Laplace equation, we derived a theoretical model for the local behaviour of the liquid in such capillaries. We present a global model for the penetration velocity validated by experimental data. Artificial surfaces designed in accordance with this model prevent liquid flow in one direction while sustaining it in the other. Such passive directional liquid transport could lead to process improvements and reduction of resources in many technical applications. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Penetration of topical, oral, and combined administered ofloxacin into the subretinal fluid

PubMed Central

Cekic, O.; Batman, C.; Yasar, U.; Totan, Y.; Basci, N.; Bozkurt, A.; Zilelioglu, O.; Kayaalp, S

1999-01-01

AIMS—To assess the subretinal fluid (SRF) levels of ofloxacin following topical, oral or combined administration.
METHODS—31 patients undergoing conventional retinal reattachment surgery were randomly assigned to three groups. Nine patients received topical ofloxacin, 11 patients received oral ofloxacin, and the other 11 patients received combined administration. Collected SRF samples were analysed for drug level by using high performance liquid chromatography.
RESULTS—SRF drug levels after oral and combined administration were significantly higher than that after topical administration (p=0.0002 and p=0.0002, respectively) while there was no significant difference between oral and combined administration (p=0.0844).
CONCLUSIONS—Ocular bioavailability of ofloxacin in SRF after oral and combined administration is equivalent. The addition of oral ofloxacin to topical therapy increased drug SRF penetration sixfold.

 PMID:10502583

Return on Investment (ROI) Framework Case Study: CTH.

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

Corro, Janna L.

CTH is a Eulerian code developed at Sandia National Laboratories capable of modeling the hydrodynamic response of explosives, liquids, gases, and solids. The code solves complex multi-dimensional problems characterized by large deformations and strong shocks that are composed of various material configurations. CTH includes models for material strength, fracture, porosity, and high explosive detonation and initiation. The code is an acronym for a complex series of names relating to its origin. A full explanation can be seen in Appendix A. The software breaks penetration simulations into millions of grid-like “cells”. As a modeled projectile impacts and penetrates a target, progressivelymore » smaller blocks of cells are placed around the projectile, which show in detail deformations and breakups. Additionally, the code is uniquely suited to modeling blunt impact and blast loading leading to human body injury.« less

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

Checco, A.; Hofmann, T.; DiMasi, E.

The details of air nanobubble trapping at the interface between water and a nanostructured hydrophobic silicon surface are investigated using X-ray scattering and contact angle measurements. Large-area silicon surfaces containing hexagonally packed, 20 nm wide hydrophobic cavities provide ideal model surfaces for studying the morphology of air nanobubbles trapped inside cavities and its dependence on the cavity depth. Transmission small-angle X-ray scattering measurements show stable trapping of air inside the cavities with a partial water penetration of 5-10 nm into the pores, independent of their large depth variation. This behavior is explained by consideration of capillary effects and the cavitymore » geometry. For parabolic cavities, the liquid can reach a thermodynamically stable configuration - a nearly planar nanobubble meniscus - by partially penetrating into the pores. This microscopic information correlates very well with the macroscopic surface wetting behavior.« less

A Variational Method to Retrieve the Extinction Profile in Liquid Clouds Using Multiple Field-of-View Lidar

NASA Technical Reports Server (NTRS)

Pounder, Nicola L.; Hogan, Robin J.; Varnai, Tamas; Battaglia, Alessandro; Cahalan, Robert F.

2011-01-01

While liquid clouds playa very important role in the global radiation budget, it's been very difficult to remotely determine their internal cloud structure. Ordinary lidar instruments (similar to radars but using visible light pulses) receive strong signals from such clouds, but the information is limited to a thin layer near the cloud boundary. Multiple field-of-view (FOV) lidars offer some new hope as they are able to isolate photons that were scattered many times by cloud droplets and penetrated deep into a cloud before returning to the instrument. Their data contains new information on cloud structure, although the lack of fast simulation methods made it challenging to interpret the observations. This paper describes a fast new technique that can simulate multiple-FOV lidar signals and can even estimate the way the signals would change in response to changes in cloud properties-an ability that allows quick refinements in our initial guesses of cloud structure. Results for a hypothetical airborne three-FOV lidar suggest that this approach can help determine cloud structure for a deeper layer in clouds, and can reliably determine the optical thickness of even fairly thick liquid clouds. The algorithm is also applied to stratocumulus observations by the 8-FOV airborne "THOR" lidar. These tests demonstrate that the new method can determine the depth to which a lidar provides useful information on vertical cloud structure. This work opens the way to exploit data from spaceborne lidar and radar more rigorously than has been possible up to now.

Spray Penetration with a Simple Fuel Injection Nozzle

NASA Technical Reports Server (NTRS)

Miller, Harold E; Beardsley, Edward G

1926-01-01

The purpose of the tests covered by this report was to obtain specific information on the rate of penetration of the spray from a simple injection nozzle, having a single orifice with a diameter of 0.015 inch when injecting into compressed gases. The results have shown that the effects of both chamber and fuel pressures on penetration are so marked that the study of sprays by means of high-speed photography or its equivalent is necessary if the effects are to be appreciated sufficiently to enable rational analysis. It was found for these tests that the negative acceleration of the spray tip is approximately proportional to the 1.5 power of the instantaneous velocity of the spray tip.

Single wall penetration equations

NASA Technical Reports Server (NTRS)

Hayashida, K. B.; Robinson, J. H.

1991-01-01

Five single plate penetration equations are compared for accuracy and effectiveness. These five equations are two well-known equations (Fish-Summers and Schmidt-Holsapple), two equations developed by the Apollo project (Rockwell and Johnson Space Center (JSC), and one recently revised from JSC (Cour-Palais). They were derived from test results, with velocities ranging up to 8 km/s. Microsoft Excel software was used to construct a spreadsheet to calculate the diameters and masses of projectiles for various velocities, varying the material properties of both projectile and target for the five single plate penetration equations. The results were plotted on diameter versus velocity graphs for ballistic and spallation limits using Cricket Graph software, for velocities ranging from 2 to 15 km/s defined for the orbital debris. First, these equations were compared to each other, then each equation was compared with various aluminum projectile densities. Finally, these equations were compared with test results performed at JSC for the Marshall Space Flight Center. These equations predict a wide variety of projectile diameters at a given velocity. Thus, it is very difficult to choose the 'right' prediction equation. The thickness of a single plate could have a large variation by choosing a different penetration equation. Even though all five equations are empirically developed with various materials, especially for aluminum alloys, one cannot be confident in the shield design with the predictions obtained by the penetration equations without verifying by tests.

Contribution to Estimating Bearing Capacity of Pile in Clayey Soils

NASA Astrophysics Data System (ADS)

Drusa, Marián; Gago, Filip; Vlček, Jozef

2016-12-01

The estimation of real geotechnical parameters is key factor for safe and economic design of geotechnical structures. One of these are pile foundations, which require proper design and evaluation due to accessing more deep foundation soil and because remediation work of not bearable piles or broken piles is a crucial operation. For this reason, geotechnical field testing like cone penetration test (CPT), standard penetration (SPT) or dynamic penetration test (DP) are realized in order to receive continuous information about soil strata. Comparing with rotary core drilling type of survey with sampling, these methods are more progressive. From engineering geologist point of view, it is more important to know geological characterization of locality but geotechnical engineers have more interest above the real geotechnical parameters of foundation soils. The role of engineering geologist cannot be underestimated because important geological processes in origin or during history can explain behaviour of a geological environment. In effort to streamline the survey, investigation by penetration tests is done as it is able to provide enough information for designers. This paper deals with actual trends in pile foundation design; because there are no new standards and usable standards are very old. Estimation of the bearing capacity of a single pile can be demonstrated on the example of determination of the cone factor Nk from CPT testing. Then results were compared with other common methods.

Numerical study of effect of the gas-coolant free surface on the droplet fragmentation behavior of coolants

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

Li, H.X.; Anh, B.V.; Dinh, T.N.

1999-07-01

This paper presents results of a numerical investigation on the behavior of melt drops falling in a gas (vapor) space and then penetrating into a liquid volume through the gas-liquid interface. The phenomenon studied here is, usually, observed when a liquid drop falls through air into a water pool and is, specially, of interest when a hypothetical severe reactor core meltdown accident is considered. The objective of this work is to study the effect of the gas-liquid interface on the dynamic evolution of the interaction area between the fragmenting melt drop and water. In the present study, the Navier-Stokes equationsmore » are solved for three phases (gas, liquid and melt-drop) using a higher-order, explicit, numerical method, called Cubic-Interpolated Pseudo-Particle (CIP) method, which is employed in combination with an advanced front-capturing scheme, named the Level Set Algorithm (LSA). By using this method, reasonable physical pictures of droplet deformation and fragmentation during movement in a stationary uniform water pool, and in a gas-liquid two-layer volume, is simulated. Effect of the gas-liquid interface on the drop deformation and fragmentation is analyzed by comparing the simulation results obtained for the two cases. Effects of the drop geometry, and of the flow conditions, on the behavior of the melt drop are also analyzed.« less

Numerical simulation of the gas-liquid interaction of a liquid jet in supersonic crossflow

NASA Astrophysics Data System (ADS)

Li, Peibo; Wang, Zhenguo; Sun, Mingbo; Wang, Hongbo

2017-05-01

The gas-liquid interaction process of a liquid jet in supersonic crossflow with a Mach number of 1.94 was investigated numerically using the Eulerian-Lagrangian method. The KH (Kelvin-Helmholtz) breakup model was used to calculate the droplet stripping process, and the secondary breakup process was simulated by the competition of RT (Rayleigh-Taylor) breakup model and TAB (Taylor Analogy Breakup) model. A correction of drag coefficient was proposed by considering the compressible effects and the deformation of droplets. The location and velocity models of child droplets after breakup were improved according to droplet deformation. It was found that the calculated spray features, including spray penetration, droplet size distribution and droplet velocity profile agree reasonably well with the experiment. Numerical results revealed that the streamlines of air flow could intersect with the trajectory of droplets and are deflected towards the near-wall region after they enter into spray zone around the central plane. The analysis of gas-liquid relative velocity and droplet deformation suggested that the breakup of droplets mainly occurs around the front region of the spray where gathered a large number of droplets with different sizes. The liquid trailing phenomenon of jet spray which has been discovered by the previous experiment was successfully captured, and a reasonable explanation was given based on the analysis of gas-liquid interaction process.

Reliability Study of Beam Lead Sealed Junction Devices

DTIC Science & Technology

1975-03-01

metallurgy was reportedly less prone to migration or corrosion, the junctions were sealed with silicon nitride which is impervious to sodium ion...normal solution). This solution was used both to test device hermeticity and to provide a sodium ion penetration test. The deionized water and...were looked for, but not found, were sodium ion penetration and platinum migration. Several of the devices that were sealed with saline solution were

Jet Formation and Penetration Study of Double-Layer Shaped Charge

NASA Astrophysics Data System (ADS)

Wang, Zhe; Jiang, Jian-Wei; Wang, Shu-You; Liu, Han

2018-04-01

A theoretical analysis on detonation wave propagation in a double-layer shaped charge (DLSC) is performed. Numerical simulations using the AUTODYN software are carried out to compare the distinctions between jet formations in DLSC and ordinary shaped charge (OSC), in particular, the OSC made using a higher detonation velocity explosive, which is treated as the outer layer charge in the DLSC. The results show that the improved detonation velocity ratio and radial charge percentage of outer-to-inner layer charge are conducive to the formation of a convergent detonation wave, which contributes to enhancement of jet tip velocity in DLSC. The thickness and mass percentages of liner flowing into jet in DLSC closely follow the exponential distribution along the radial direction, but the percentages in DLSC and the mass of effective jet, which have significant influence on the penetration depth, are lower than those in OSC with the outer layer charge. This implies that the total charge energy is the major factor controlling the effective jet formation, which is confirmed by the verification tests using flash X-ray system and following penetration tests. The numerical simulation and test results compare well, while penetration test results indicate that the performance of DLSC is not better than that of OSC with the outer layer charge, due to the differences in jet formation.

Microencapsulated Fluorescent Dye Penetrant.

DTIC Science & Technology

1979-07-01

Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

Medicaid Waivers and Public Sector Mental Health Service Penetration Rates for Youth.

PubMed

Graaf, Genevieve; Snowden, Lonnie

2018-01-22

To assist families of youth with serious emotional disturbance in financing youth's comprehensive care, some states have sought and received Medicaid waivers. Medicaid waivers waive or relax the Medicaid means test for eligibility to provide insurance coverage to nonpoor families for expensive, otherwise out-of-reach treatment for youth with Serious Emotional Disturbance (SED). Waivers promote treatment access for the most troubled youth, and the present study investigated whether any of several Medicaid waiver options-and those that completely omit the means test in particular-are associated with higher state-wide public sector treatment penetration rates. The investigators obtained data from the U.S. Census, SAMHSA's Uniform Reporting System, and the Centers for Medicare and Medicaid Services. Analysis employed random intercept and random slope linear regression models, controlling for a variety of state demographic and fiscal variables, to determine whether a relationship between Medicaid waiver policies and state-level public sector penetration rates could be observed. Findings indicate that, whether relaxing or completely waiving Medicaid's qualifying income limits, waivers increase public sector penetration rates, particularly for youth under age 17. However, completely waiving Medicaid income limits did not uniquely contribute to penetration rate increases. States offering Medicaid waivers that either relax or completely waive Medicaid's means test to qualify for health coverage present higher public sector treatment rates for youth with behavioral health care needs. There is no evidence that restricting the program to waiving the means test for accessing Medicaid would increase treatment access. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A 40-foot static cone penetrometer

USGS Publications Warehouse

Beard, R.M.; Lee, H.J.

1982-01-01

The Navy needs a lightweight device for testing seafloor soils to sub bottom depths of 12 meters in water depths to 60 meters. To meet this need a quasistatic cone penetration device that uses water jetting to reduce friction on the cone rod has been developed. This device is called the XSP-40. The 5-ton XSP-40 stands 15 meters tall and pushes a standard 5-ton cone into the seafloor. It is remotely controlled with an electronic unit on the deck of the support vessel. All cone outputs are recorded directly as a function of penetration depth with a strip chart recorder. A full suite of gauges is provided. on the electronic unit for monitoring the XSP-40's performance during a test .. About 40 penetration tests have been performed with very good success. The XSP-40 was field tested in Norton Sound, off the west coast of Alaska. The general objective, in addition to evaluation of the device, was to gather geotechnical information on sediments that may be involved in processes potentially hazardous to offshore development. Four example penetration records are presented from gas charged sediment zones and areas near the Yukon River delta. In general it was determined that soil classification from cone data agreed well with classifications from core samples. Relative densities of the silt-sand to sandy-silt soils were usually very high. The significance of these results are discussed with respect to storm wave, liquefaction. It is concluded that the XSP-40 is a durable and reliable piece of equipment capable of achieving penetration beyond that possible when not using the water jet system.

Comparisons of Calculations with PARTRAC and NOREC: Transport of Electrons in Liquid Water

PubMed Central

Dingfelder, M.; Ritchie, R. H.; Turner, J. E.; Friedland, W.; Paretzke, H. G.; Hamm, R. N.

2013-01-01

Monte Carlo computer models that simulate the detailed, event-by-event transport of electrons in liquid water are valuable for the interpretation and understanding of findings in radiation chemistry and radiation biology. Because of the paucity of experimental data, such efforts must rely on theoretical principles and considerable judgment in their development. Experimental verification of numerical input is possible to only a limited extent. Indirect support for model validity can be gained from a comparison of details between two independently developed computer codes as well as the observable results calculated with them. In this study, we compare the transport properties of electrons in liquid water using two such models, PARTRAC and NOREC. Both use interaction cross sections based on plane-wave Born approximations and a numerical parameterization of the complex dielectric response function for the liquid. The models are described and compared, and their similarities and differences are highlighted. Recent developments in the field are discussed and taken into account. The calculated stopping powers, W values, and slab penetration characteristics are in good agreement with one another and with other independent sources. PMID:18439039

Data book for 12.5-inch diameter SRB thermal model water flotation test - 14.7 psia, series P024

NASA Technical Reports Server (NTRS)

Allums, S. L.

1974-01-01

Tests were conducted to determine how thermal conditions affect space shuttle solid rocket booster (SRB) flotation. Acceleration, pressure, and temperature data were recorded from initial water impact to final flotation position using a 12.5-inch diameter thermal model of the SRB at ambient pressure. The model was 136.9 inches long and weighed 117.3 lbm. The tests indicated the following differences from ambient temperature tests: (1) significant negative static pressures can occur during penetration; (2) maximum penetration is increased; and (3) final flotation is in the spar buoy mode.

An Autonomous Cryobot Synthetic Aperture Radar for Subsurface Exploration of Europa

NASA Astrophysics Data System (ADS)

Pradhan, O.; Gasiewski, A. J.

2015-12-01

We present the design and field testing of a forward-looking end-fire synthetic aperture radar (SAR) for the 'Very deep Autonomous Laser-powered Kilowatt-class Yo-yoing Robotic Ice Explorer' (VALKYRIE) ice-penetrating cryobot. This design demonstrates critical technologies that will support an eventual landing and ice penetrating mission to Jupiter's icy moon, Europa. Results proving the feasibility of an end-fire SAR system for vehicle guidance and obstacle avoidance in a sub-surface ice environment will be presented. Data collected by the SAR will also be used for constructing sub-surface images of the glacier which can be used for: (i) mapping of englacial features such as crevasses, moulins, and embedded liquid water and (ii) ice-depth and glacier bed analysis to construct digital elevation models (DEM) that can help in the selection of crybot trajectories and future drill sites for extracting long-term climate records. The project consists of three parts, (i) design of an array of four conformal cavity-backed log-periodic folded slot dipole array (LPFSA) antennas that form agile radiating elements, (ii) design of a radar system that includes RF signal generation, 4x4 transmit-receive antenna switching and isolation and digital SAR data processing and (iii) field testing of the SAR in melt holes. The antennas have been designed, fabricated, and lab tested at the Center for Environmental Technology (CET) at CU-Boulder. The radar system was also designed and integrated at CET utilizing rugged RF components and FPGA based digital processing. Field testing was performed in conjunction with VALKYRIE tests by Stone Aerospace in June, 2015 on Matanuska Glacier, Alaska. The antennas are designed to operate inside ice while being immersed in a thin layer of surrounding low-conductivity melt water. Small holes in the corners of the cavities allow flooding of these cavities with the same melt-water thus allowing for quarter-wavelength cavity-backed reflection. Testing of the antenna array was first carried out by characterizing their operation inside a large ice block at the Stone Aerospace facility in Austin, TX. The complete radar system was then tested on the Matanuska glacier in Alaska, which is an effective Earth analog to Europan sub-surface exploration.

Near-infrared sensitive photorefractive device using polymer dispersed liquid crystal and BSO:Ru hybrid structure.

PubMed

Liu, Ren Chung; Marinova, Vera; Lin, Shiuan Huei; Chen, Ming-Syuan; Lin, Yi-Hsin; Hsu, Ken Yuh

2014-06-01

A near-infrared sensitive hybrid device, based on a Ru-doped BSO photorefractive substrate and polymer dispersed liquid crystal (PDLC) layer, is reported. It is found that the photoexcited charge carriers generated in the BSO:Ru substrate create an optically induced space charge field, sufficient to penetrate into the PDLC layer and to re-orient the LC molecules inside the droplets. Beam-coupling measurements at the Bragg regime are performed showing prospective amplification values and high spatial resolution. The proposed structure does not require indium tin oxide (ITO) contacts and alignment layers. Such a device allows all the processes to be controlled by light, thus opening further potential for real-time image processing at the near-infrared range.

Microwave-superheated Vics Vapo Rub: an ocular public health danger.

PubMed

Fung, Anne E; Oxford, Karen W

2004-02-01

To report a case of a microwave-oven superheated petroleum-based liquid causing severe chemical and thermal ocular burns treated successfully with amniotic membrane transplantation. Observational case report. Retrospective review of clinical case. A 77-year-old woman sustained a severe combined chemical and thermal burn from microwave-heated Vicks Vapo-Rub requiring amniotic membrane transplant, with subsequent development of phacomorphic glaucoma, requiring cataract extraction, and bullous keratopathy, requiring penetrating keratoplasty. As microwave oven use becomes more commonplace, the risk of superheating liquids becomes an increasingly significant ocular danger. Continued efforts to educate the public about safe microwave use is necessary. Additionally, amniotic membrane transplantation was found to be effective in managing a combined chemical and thermal ocular burn.

High Tc superconductors as thermal radiation shields

NASA Astrophysics Data System (ADS)

Zeller, A. F.

1990-06-01

The feasibility of using high-Tc superconductor films as IR-radiation shields for liquid-helium-temperature dewars is investigated. Calculations show that a Ba-Ca-Sr-Cu-O superconductor with Tc of 110 K, combined with a liquid-nitrogen temperature shield with an emissivity of 0.03 should produce an upper limit to the radiative heat transfer of 15 mW/sq m. The reduction of reflectivity depends on the field level and the extent of field penetration into the superconductor film, whose surface also would provide magnetic shielding for low magnetic fields. Such shields, providing both magnetic and thermal radiation shielding would be useful for spaceborne applications where exposure to the degrading effects of moist air would not be a problem.

Bioactive glass fillers reduce bacterial penetration into marginal gaps for composite restorations

PubMed Central

Khvostenko, D.; Hilton, T. J.; Ferracane, J. L.; Mitchell, J. C.; Kruzic, J. J.

2015-01-01

Objectives Bioactive glass (BAG) is known to possess antimicrobial and remineralizing properties; however, the use of BAG as a filler for resin based composite restorations to slow recurrent caries has not been studied. Accordingly, the objective of this study was to investigate the effect of 15 wt% BAG additions to a resin composite on bacterial biofilms penetrating into marginal gaps of simulated tooth fillings in vitro during cyclic mechanical loading. Methods Human molars were machined into approximately 3 mm thick disks of dentin and 1.5–2 mm deep composite restorations were placed. A narrow 15–20 micrometer wide dentin-composite gap was allowed to form along half of the margin by not applying dental adhesive to that region. Two different 72 wt% filled composites were used, one with 15 wt% BAG filler (15BAG) and the balance silanated strontium glass and one filled with OX-50 and silanated strontium glass without BAG (0BAG – control). Samples of both groups had Streptococcus mutans biofilms grown on the surface and were tested inside a bioreactor for two weeks while subjected to periods of cyclic mechanical loading. After post-test biofilm viability was confirmed, each specimen was fixed in glutaraldehyde, gram positive stained, mounted in resin and cross-sectioned to reveal the gap profile. Depth of biofilm penetration for 0BAG and 15BAG was quantified as the fraction of gap depth. The data were compared using a Student’s t-test. Results The average depth of bacterial penetration into the marginal gap for the 15BAG samples was significantly smaller (~61%) in comparison to 0BAG, where 100% penetration was observed for all samples with the biofilm penetrating underneath of the restoration in some cases. Significance BAG containing resin dental composites reduce biofilm penetration into marginal gaps of simulated tooth restorations. This suggests BAG containing composites may have the potential to slow the development and propagation of secondary tooth decay at restoration margins. PMID:26621028

The interaction between clothing and air weapon pellets.

PubMed

Wightman, G; Wark, K; Thomson, J

2015-01-01

Comparatively few studies have been carried out on air weapon injuries yet there are significant number of injuries and fatalities caused by these low power weapons because of their availability and the public perception that because they need no licence they are assumed to be safe. In this study ballistic gel was tested by Bloom and rupture tests to check on consistency of production. Two series of tests were carried out firing into unclothed gel blocks and blocks loosely covered by different items of clothing to simulate attire (tee shirt, jeans, fleece, and jacket). The damage to the clothing caused by different shaped pellets when fired at different ranges was examined. The apparent hole size was affected by the shape of pellet (round, pointed, flat and hollow point) and whether damage was predominantly caused by pushing yarn to one side or by laceration of the yarn through cutting or tearing. The study also compared penetration into clothed gel and unclothed gel under identical conditions, and loose clothing greatly reduced penetration. With loose clothing at 9.1 m range clothing reduced penetration to 50-70% of the penetration of unclothed gel but at 18.3m range only 7 out of 36 shots penetrated the gel. This cannot be accounted for by the energy loss at the longer range (3-7% reduction from 9.1 m to 18.3 m range in unclothed gels) and it is suggested that impulse may have a role to play. Shots that did not penetrate the gel were used to estimate the possible stopping time for the pellet (around 75 μs) and force (1700 N) or stress (100 MPa) required to bring the pellet to a halt. Even with these low energy projectiles, cloth fibres were entrained in the gel showing the potential for penetration of the body and subsequent infection. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Medicaid HMO penetration and its mix: did increased penetration affect physician participation in urban markets?

PubMed

Adams, E Kathleen; Herring, Bradley

2008-02-01

To use changes in Medicaid health maintenance organization (HMO) penetration across markets over time to test for effects on the extent of Medicaid participation among physicians and to test for differences in the effects of increased use of commercial versus Medicaid-dominant plans within the market. The nationally representative Community Tracking Study's Physician Survey for three periods (1996-1997, 1998-1999, and 2000-2001) on 29,866 physicians combined with Centers for Medicare and Medicaid Services (CMS) and InterStudy data. Market-level estimates of Medicaid HMO penetration are used to test for (1) any participation in Medicaid and (2) the degree to which physicians have an "open" (i.e., nonlimited) practice accepting new Medicaid patients. Models account for physician, firm, and local characteristics, Medicaid relative payment levels adjusted for geographic variation in practice costs, and market-level fixed effects. There is a positive effect of increases in commercial Medicaid HMO penetration on the odds of accepting new Medicaid patients among all physicians, and in particular, among office-based physicians. In contrast, there is no effect, positive or negative, from expanding the penetration of Medicaid-dominant HMO plans within the market. Increases in cost-adjusted Medicaid fees, relative to Medicare levels, were associated with increases in the odds of participation and of physicians having an "open" Medicaid practice. Provider characteristics that consistently lower participation among all physicians include being older, board certified, a U.S. graduate and a solo practitioner. The effects of Medicaid HMO penetration on physician participation vary by the type of plan. If states are able to attract and retain commercial plans, participation by office-based physicians is likely to increase in a way that opens existing practices to more new Medicaid patients. Other policy variables that affect participation include the presence of a federally qualified health center (FQHC) in the county and cost-adjusted Medicaid fees relative to Medicare.

Collectively Facilitated Behavior of the Neonate Caterpillars of Cactoblastis cactorum (Lepidoptera: Pyralidae)

PubMed Central

Fitzgerald, Terrence D.; Wolfin, Michael; Young, Ryan; Meyer, Katelyn; Fabozzi, Elizabeth

2016-01-01

The behavioral biology of the first instar larva of Cactoblastis cactorum was studied from the time of eclosion until the colony penetrated and initiated excavation of the host plant. Hatching from an egg stick was asynchronous, requiring 20 h for the entire cohort to eclose at 50%–70% RH and significantly longer at a lower range of RHs. On eclosion, neonates aggregated in an arena at the base of their egg stick and did not attempt to excavate the cladode until an average of 25 caterpillars had collected, approximately 15 h after the onset of egg hatch. Typically only a single entrance hole was formed, limiting the active process of excavating to one or a few individuals at-a-time until the host was fully penetrated and enlarged internally. Olfactometer tests showed that the neonates are strongly attracted to volatile chemicals released when caterpillars chewed into the cladode, accounting for the strong fidelity of the whole cohort to the initial site of penetration. In one instance, the caterpillars were observed to deal with an explosive release of mucilage by imbibing the liquid until the flooded zone was drained and the caterpillars could reenter the plant through the original entrance hole. Once inside the cladode, marked individuals adopted a regular cycle of defecating at the surface at a mean interval of approximately 10 min when followed for 35 successive cycles. Blanket spraying cladodes with a mandibular gland extract prior to hatching led to the independent dispersal of neonates and a failure to form an arena. When the cladode was impenetrable at the site of eclosion, the active cohort of unfed neonates set off together in search of a new site, marking and following a persistent trail that allowed late-to-eclose caterpillars to join their departed siblings. The adaptive significance of these observations is discussed in the context of the life history of the caterpillar. PMID:27809231

Correlation between swallowing-related quality of life and videofluoroscopy after head and neck cancer treatment.

PubMed

Andrade, Margareth Souza; Gonçalves, Aline Nogueira; Guedes, Renata Lígia Vieira; Barcelos, Camila Barbosa; Slobodticov, Luciana Dall'Agnol Siqueira; Lopes, Simone Aparecida Claudino; Francisco, Ana Lúcia Noronha; Angelis, Elisabete Carrara de

2017-03-09

The use of symptom-specific questionnaires on head and neck cancer (HNC), together with objective swallowing measures, can be sensitive to changes in quality of life (QoL) resulting from dysphagia, but this tool is not broadly used as a complement to clinical evaluations. To analyze the correlation between the M. D. Anderson Dysphagia Inventory (MDADI) questionnaire and videofluoroscopy (VF) in patients treated for head and neck cancer. This is a retrospective study with review of clinical data, VF and MDADI results. The study sample was composed of adult patients (>18 y.o.) treated for tumors at the oral cavity, oropharynx, hypopharynx, and larynx, regardless of treatment type. For the VF examination, swallowing of 5 and 20 ml of nectar-thick liquids were considered. The Mann-Whitney nonparametric test was applied to evaluate the correlations between the MDADI and VF. Thirty-nine patients, mostly men (87.18%), with mean age of 61 years participated in the study. Most patients (16) presented oral cavity tumors (41.03%). Twenty-two patients were in advanced clinical stage (IV). Surgery was the most prevalent treatment (41.03%). Approximately half of the participants (20) received oral feeding. The total mean (TM) on the MDADI was 63.36. Comparison between VF and MDADI data showed significant correlation between TM, emotional domain (ED), and physical domain (PD) with penetration during the swallowing of 5 ml. Penetration and aspiration with 20 ml determined worse QoL on the global (p=0.018 and p=0.0053), emotional (p=0.0012 and p=0.027) and physical (p=0.0002 and p=0.0051) domains, and TM (p=0.0023 and p=0.0299), respectively. The presence of stasis did not determine worse QoL. Patients treated for HNC who presented penetration/aspiration showed worse QoL on the emotional and physical domains of the MDADI.

Update of correlations between cone penetration and boring log data.

DOT National Transportation Integrated Search

2008-03-01

The cone penetration test (CPT) has been widely used in Louisiana in the last two decades as an in situ tool to characterize engineering : properties of soils. In addition, conventional drilling and sample retrieval using Shelby tube followed by labo...

Geohydrologic and drill-hole data for test well USW H-3, Yucca Mountain, Nye County, Nevada

USGS Publications Warehouse

Thordarson, William; Rush, F.E.; Spengler, R.W.; Waddell, S.J.

1984-01-01

Test well USW H-3 is one of a series of test wells drilled in and near the southwestern part of the Nevada Test Site for hydraulic testing, hydrologic monitoring, and geophysical logging. The work was performed in cooperation with the U.S. Department of Energy as part of the Nevada Nuclear Waste Storage investigations. The well penetrated volcanic tuffs of Tertiary age to a depth of 1,219 meters. This report presents data collected to determine the hydraulic characteristics of rocks penetrated. Data on drilling operations, lithology, borehole geophysics, hydrologic monitoring, pumping, swabbing, and injection tests for the well are contained in this report. (USGS)

A comparison of 2 methods of endoscopic laryngeal sensory testing: a preliminary study.

PubMed

Kaneoka, Asako; Krisciunas, Gintas P; Walsh, Kayo; Raade, Adele S; Langmore, Susan E

2015-03-01

This study examined the association between laryngeal sensory deficits and penetration or aspiration. Two methods of testing laryngeal sensation were carried out to determine which was more highly correlated with Penetration-Aspiration Scale (PAS) scores. Healthy participants and patients with dysphagia received an endoscopic swallowing evaluation including 2 sequential laryngeal sensory tests-air pulse followed by touch method. Normal/impaired responses were correlated with PAS scores. Fourteen participants completed the endoscopic swallowing evaluation and both sensory tests. The air pulse method identified sensory impairment with greater frequency than the touch method (P<.0001). However, the impairment identified by the air pulse method was not associated with abnormal PAS scores (P=.46). The sensory deficits identified by the touch method were associated with abnormal PAS scores (P=.05). Sensory impairment detected by the air pulse method does not appear to be associated with risk of penetration/aspiration. Significant laryngeal sensory loss revealed by the touch method is associated with compromised airway protection. © The Author(s) 2014.

Geohydrology of test well USW H-3, Yucca Mountain, Nye County, Nevada

USGS Publications Warehouse

Thordarson, William; Rush, F.E.; Waddell, S.J.

1985-01-01

Test well USW H-3 is one of several wells drilled in the southwestern part of the Nevada Test Site for hydraulic testing, hydrologic monitoring, and geophysical logging. The work was performed in cooperation with the U.S. Department of Energy. The rocks penetrated by the well to a total depth of 1,219 meters were volcanic tuffs of Tertiary age. The most transmissive zone in this well is in the upper part of the Tram Member of the Crater Flat Tuff that was penetrated at a depth from 809 to 841 meters; transmissivity is about 7 x 10 -1 meter squared per day. The remainder of the rocks penetrated between the depths of 841 to 1,219 meters have a transmissivity of about 4 x 10 -1 meter squared per day and are predominatly in the Tram Member of the Crater Flat Tuff and the Lithic Ridge Tuff in the depths from 841 to 1,219 meters. (USGS)

Ground penetrating radar imaging of cap rock, caliche and carbonate strata

USGS Publications Warehouse

Kruse, S.E.; Schneider, J.C.; Campagna, D.J.; Inman, J.A.; Hickey, T.D.

2000-01-01

Field experiments show ground penetrating radar (GPR) can be used to image shallow carbonate stratigraphy effectively in a variety of settings. In south Florida, the position and structure of cap rock cover on limestone can be an important control on surface water flow and vegetation, but larger scale outcrops (tens of meters) of cap rock are sparse. GPR mapping through south Florida prairie, cypress swamp and hardwood hammock resolves variations in thickness and structure of cap rock to ~3 m and holds the potential to test theories for cap rock-vegetation relationships. In other settings, carbonate strata are mapped to test models for the formation of local structural anomalies. A test of GPR imaging capabilities on an arid caliche (calcrete) horizon in southeastern Nevada shows depth penetration to ~2 m with resolution of the base of caliche. GPR profiling also succeeds in resolving more deeply buried (~5 m) limestone discontinuity surfaces that record subaerial exposure in south Florida. (C) 2000 Elsevier Science B.V. All rights reserved.Field experiments show ground penetrating radar (GPR) can be used to image shallow carbonate stratigraphy effectively in a variety of settings. In south Florida, the position and structure of cap rock cover on limestone can be an important control on surface water flow and vegetation, but larger scale outcrops (tens of meters) of cap rock are sparse. GPR mapping through south Florida prairie, cypress swamp and hardwood hammock resolves variations in thickness and structure of cap rock to approx. 3 m and holds the potential to test theories for cap rock-vegetation relationships. In other settings, carbonate strata are mapped to test models for the formation of local structural anomalies. A test of GPR imaging capabilities on an arid caliche (calcrete) horizon in southeastern Nevada shows depth penetration to approx. 2 m with resolution of the base of caliche. GPR profiling also succeeds in resolving more deeply buried (approx. 5 m) limestone discontinuity surfaces that record subaerial exposure in south Florida.

Wireline Deep Drill for the Exploration of Icy Bodies

NASA Technical Reports Server (NTRS)

Paulsen, G.; Zacny, K.; Mellerowicz, B.; Craft, J.; Bar-Cohen, Y.; Beegle, L.; Sherrit, S.; Badescu, M.; Corsetti, F.; Ibarra, Y.

2013-01-01

One of the most pressing current questions in space science is whether life has ever arisen anywhere else in the universe. Water is a critical prerequisite for all life-as-we-know-it, thus the possible exploration targets for extraterrestrial life are bodies that have or had copious liquid: Mars, Europa, and Enceladus. Due to the oxidizing nature of Mars' surface, as well as subsurface liquid water reservoirs present on Europa and Enceladus, the search for evidence of existing life must likely focus on subsurface locations, at depths sufficient to support liquid water or retain biologic signatures. To address these questions, an Auto-Gopher sampler has been developed that is a wireline type drill. This drill is suspended on a tether and its motors and mechanisms are built into a tube that ends with a coring bit. The tether provides the mechanical connection to a rover/lander on a surface as well as power and data communication. Upon penetrating to a target depth, the drill is retracted from the borehole, the core is deposited into a sample transfer system, and the drill is lowered back into the hole. Wireline operation sidesteps one of the major drawbacks of traditional continuous drill string systems by obviating the need for multiple drill sections, which add significantly to the mass and the complexity of the system (i.e. penetration rate was 40 cm per hour). Drilling to 2 meter depth and recovering of cores every 10 cm took a total time of 15 hours (a single step of drilling 10 cm and retrieving the core was 45 minutes). Total energy to reach the 2 m depth was 500 Whr. The Weight on Bit was limited to less than 70 Newton. The core recovery was 100%.

External tank space debris considerations

NASA Technical Reports Server (NTRS)

Elfer, N.; Baillif, F.; Robinson, J.

1992-01-01

Orbital debris issues associated with maintaining a Space Shuttle External Tank (ET) on orbit are presented. The first issue is to ensure that the ET does not become a danger to other spacecraft by generating space debris, and the second is to protect the pressurized ET from penetration by space debris or meteoroids. Tests on shield designs for penetration resistance showed that when utilized with an adequate bumper, thermal protection system foam on the ET is effective in preventing penetration.

Fire Resistance Testing of Bulkhead and Deck Penetrations.

DTIC Science & Technology

1985-10-01

consisted of a steel plate identical to that used in the Class A-0 assembly, but rockwool insulation was applied to the fire side of the steel plate and...penetration samples were then insulated with rockwool batts to form a Class A-60 assembly (Figure 2). Between nine and twenty-eight temperature readings...representative of Class A-O construction. The UL staff secured insulation ( rockwool batts) to the fire side of the steel plates and penetrating items to prepare

The Effects of Hygrothermal Aging on the Impact Penetration Resistance of Triaxially Braided Composites

NASA Technical Reports Server (NTRS)

Pereira, J. Michael; Revilock, Duane M.; Ruggeri, Charles R.; Roberts, Gary D.; Kohlman, Lee W.; Miller, Sandi G.

2016-01-01

An experimental study was conducted to measure the effects of long term hygrothermal aging on the impact penetration resistance of triaxially braided polymer composites. Flat panels of three different materials were subjected to repeated cycles of high and low temperature and high and low humidity for two years. Samples of the panels were periodically tested under impact loading during the two year time period. The purpose of the study was to identify and quantify any degradation in impact penetration resistance of these composites under cyclic temperature and humidity conditions experienced by materials in the fan section of commercial gas turbine engines for a representative aircraft flight cycle. The materials tested consisted of Toray ® T700S carbon fibers in a 2D triaxial braid with three different resins, Cycom® PR520, a toughened resin, Hercules® 3502, an untoughened resin and EPON 862, intermediate between the two. The fiber preforms consisted of a quasi-isotropic 0/+60/-60 braid with 24K tows in the axial direction and 12K tows in the bias directions. The composite panels were manufactured using a resin transfer molding process producing panels with a thickness of 0.125 inches. The materials were tested in their as-processed condition and again after one year and two years of aging (1.6 years in the case of E862). The aging process involved subjecting the test panels to two cycles per day of high and low temperature and high and low humidity. A temperature range of -60degF to 250degF and a humidity range of 0 to 85% rh was used to simulate extreme conditions for composite components in the fan section of a commercial gas turbine engine. Additional testing was conducted on the as-processed PR520 composite under cryogenic conditions. After aging there was some change in the failure pattern, but there was no reduction in impact penetration threshold for any of the three systems, and in the case of the 3502 system, a significant increase in penetration threshold. There was also an increase in the penetration resistance of the PR520 system impacted under cryogenic conditions.

Structural frequency functions for an impulsive, distributed forcing function

NASA Technical Reports Server (NTRS)

Bateman, Vesta I.

1987-01-01

The response of a penetrator structure to a spatially distributed mechanical impulse with a magnitude approaching field test force levels (1-2 Mlb) were measured. The frequency response function calculated from the response to this unique forcing function is compared to frequency response functions calculated from response to point forces of about 2000 pounds. The results show that the strain gages installed on the penetrator case respond similiarly to a point, axial force and to a spatially distributed, axial force. This result suggests that the distributed axial force generated in a penetration event may be reconstructed as a point axial force when the penetrator behaves in linear manner.

Conception of a course for professional training and education in the field of computer and mobile forensics, part III: network forensics and penetration testing

NASA Astrophysics Data System (ADS)

Kröger, Knut; Creutzburg, Reiner

2014-02-01

IT security and computer forensics are important components in the information technology. From year to year, incidents and crimes increase that target IT systems or were done with their help. More and more companies and authorities have security problems in their own IT infrastructure. To respond to these incidents professionally, it is important to have well trained staff. The fact that many agencies and companies work with very sensitive data make it necessary to further train the own employees in the field of network forensics and penetration testing. Motivated by these facts, this paper - a continuation of a paper of January 2012 [1], which showed the conception of a course for professional training and education in the field of computer and mobile forensics - addresses the practical implementation important relationships of network forensic and penetration testing.

Miniature, Single Channel, Memory-Based, High-G Acceleration Recorder (Millipen)

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

Rohwer, Tedd A.

1999-06-02

The Instrumentation and Telemetry Departments at Sandia National Laboratories have been instrumenting earth penetrators for over thirty years. Recorded acceleration data is used to quantify penetrator performance. Penetrator testing has become more difficult as desired impact velocities have increased. This results in the need for small-scale test vehicles and miniature instrumentation. A miniature recorder will allow penetrator diameters to significantly decrease, opening the window of testable parameters. Full-scale test vehicles will also benefit from miniature recorders by using a less intrusive system to instrument internal arming, fusing, and firing components. This single channel concept is the latest design in anmore » ongoing effort to miniaturize the size and reduce the power requirement of acceleration instrumentation. A micro-controller/memory based system provides the data acquisition, signal conditioning, power regulation, and data storage. This architecture allows the recorder, including both sensor and electronics, to occupy a volume of less than 1.5 cubic inches, draw less than 200mW of power, and record 15kHz data up to 40,000 gs. This paper will describe the development and operation of this miniature acceleration recorder.« less

Effect of adding powder on joint properties of laser penetration welding for dual phase steel and aluminum alloy

NASA Astrophysics Data System (ADS)

Zhou, D. W.; Liu, J. S.; Lu, Y. Z.; Xu, S. H.

2017-09-01

The experiments of laser penetration welding for dual phase steel and aluminum alloy were carried out, and the effect of adding Mn or Si powder on mechanical properties and microstructure of the weld was investigated. Some defects, such as spatter, inclusion, cracks and softening in heat affected zone (HAZ), can be avoided in welding joints, and the increased penetration depth is obtained by adding Mn or Si powder. The average tensile-shear strength of Si-added joint is 3.84% higher than that of Mn-added joint, and the strength of both joints exceeds that of no-added joint. In the case of adding Mn powder, small amount of liquid Al is mixed into steel molten pool, and the Al content increases in both sides of the weld, which leads to the increased weld width in aluminum molten pool. Thus, transverse area increases in jointing steel to aluminum, which is significant for the improved tensile-shear strength of joints. As far as adding Si powder is concerned, it is not the case, the enhancement of the joint properties benefits from improvement of metallurgical reaction.

Fiber Volume Fraction Influence on Fiber Compaction in Tapered Resin Injection Pultrusion Manufacturing

NASA Astrophysics Data System (ADS)

Masuram, N. B.; Roux, J. A.; Jeswani, A. L.

2016-06-01

Liquid resin is injected into the tapered injection chamber through the injection slots to completely wetout the fiber reinforcements in a resin injection pultrusion process. As the resin penetrates through the fibers, the resin also pushes the fibers away from the wall towards the centerline causing compaction of the fiber reinforcements. The fibers are squeezed together due to compaction, making resin penetration more difficult; thus higher resin injection pressures are required to effectively penetrate through the fibers and achieve complete wetout. Fiber volume fraction in the final pultruded composite is a key to decide the mechanical and/or chemical properties of the composite. If the fiber volume fraction is too high, more fibers are squeezed together creating a fiber lean region near the wall and fiber rich region away from the wall. Also, the design of the injection chamber significantly affects the minimum injection pressure required to completely wet the fibers. A tapered injection chamber is considered such that wetout occurs at lower injection pressures due to the taper angle of the injection chamber. In this study, the effect of fiber volume fraction on the fiber reinforcement compaction and complete fiber wetout for a tapered injection chamber is investigated.

Platelet activating factor induces transient blood-brain barrier opening to facilitate edaravone penetration into the brain.

PubMed

Fang, Weirong; Zhang, Rui; Sha, Lan; Lv, Peng; Shang, Erxin; Han, Dan; Wei, Jie; Geng, Xiaohan; Yang, Qichuan; Li, Yunman

2014-03-01

The blood-brain barrier (BBB) greatly limits the efficacy of many neuroprotective drugs' delivery to the brain, so improving drug penetration through the BBB has been an important focus of research. Here we report that platelet activating factor (PAF) transiently opened BBB and facilitated neuroprotectant edaravone penetration into the brain. Intravenous infusion with PAF induced a transient BBB opening in rats, reflected by increased Evans blue leakage and mild edema formation, which ceased within 6 h. Furthermore, rat regional cerebral blood flow (rCBF) declined acutely during PAF infusion, but recovered slowly. More importantly, this transient BBB opening significantly increased the penetration of edaravone into the brain, evidenced by increased edaravone concentrations in tissue interstitial fluid collected by microdialysis and analyzed by Ultra-performance liquid chromatograph combined with a hybrid quadrupole time-of-flight mass spectrometer (UPLC-MS/MS). Similarly, incubation of rat brain microvessel endothelial cells monolayer with 1 μM PAF for 1 h significantly increased monolayer permeability to (125)I-albumin, which recovered 1 h after PAF elimination. However, PAF incubation with rat brain microvessel endothelial cells for 1 h did not cause detectable cytotoxicity, and did not regulate intercellular adhesion molecule-1, matrix-metalloproteinase-9 and P-glycoprotein expression. In conclusion, PAF could induce transient and reversible BBB opening through abrupt rCBF decline, which significantly improved edaravone penetration into the brain. Platelet activating factor (PAF) transiently induces BBB dysfunction and increases BBB permeability, which may be due to vessel contraction and a temporary decline of regional cerebral blood flow (rCBF) triggered by PAF. More importantly, the PAF induced transient BBB opening facilitates neuroprotectant edaravone penetration into brain. The results of this study may provide a new approach to improve drug delivery into the brain. © 2013 International Society for Neurochemistry.

Impact of carpet construction on fluid penetration: The case of blood.

PubMed

Feng, Chengcheng; Michielsen, Stephen; Attinger, Daniel

2018-03-01

Bloodstains and bloodstain patterns are often observed at crime scenes and their analysis through bloodstain pattern analysis (BPA) can assist in reconstructing crime scenes. However, most published work related to BPA only deals with hard, non-porous surfaces and none of the studies have carefully characterized carpets. Soft and porous carpets are often encountered at crime scenes since they are common in American homes accounting for 51% of total U.S. flooring market; this has motivated the research described herein. To assess fluid penetration into tufted carpers, a new method for determining porosity and pore size distribution in tufted carpets has been developed for bloodstains on carpet. In this study, three kinds of nylon carpet were used: a low, a medium and a high face-weight carpet. Each carpet had an antistain treatment, which was removed from half of each carpet by steam-cleaning with a pH 12 NaOH solution. This resulted in six carpet samples. Yarn twist, carpet weight, pile height, water contact angles on carpets, water contact angles on individual fibers, and fiber cross-sectional shapes were characterized. Porosity and pore size distribution were analyzed using confocal laser scanning microscopy (CLSM). Porcine blood was used as a human blood substitute at three liquid volumes (30μL, 10μL, and 2μL). Analysis showed that porous carpet construction and antistain finishing both affected penetration. The depth of blood penetration decreased with the increase of carpet face-weight but increased with increased drop height. The removal of antistain treatment increased blood penetration into the carpets and changed the pore size distribution. Effects of antistain treatment, porosity and pore size distribution of tufted carpet, and blood wicking behaviors on carpets were found to strongly affect blood penetration into the carpets. Copyright © 2018 Elsevier B.V. All rights reserved.

The evaluation of fabrics in relation to their use as protective garments in nursing and surgery. I. Physical measurements and bench tests.

PubMed Central

Lidwell, O. M.; Mackintosh, C. A.

1978-01-01

Eleven fabrics selected to provide a representative range of yarns and weaves have been examined microscopically and subjected to a series of tests. The observations were directed towards assessing the potential ability of each fabric to resist penetration by particles, such as skin scales, which might carry micro-organisms. The number, size and shape of pores penetrating through the material were estimated and the penetration of test dusts assessed in several ways. While, generally, the relative merits of the fabrics are similar whatever test or measurement is considered there are a number of significant exceptions which reflect peculiarities of the test system or of a fabric. Comparison with the results of dispersal experiments with volunteers wearing garments made of the fabrics is made in a following paper. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Plate 3 Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:731024

Swallowing Kinematics and Factors Associated with Laryngeal Penetration and Aspiration in Stroke Survivors with Dysphagia.

PubMed

Seo, Han Gil; Oh, Byung-Mo; Han, Tai Ryoon

2016-04-01

The purpose of this study was to investigate swallowing kinematics and explore kinematic factors related with penetration-aspiration in patients with post-stroke dysphagia. Videofluoroscopic images of 68 patients with post-stroke dysphagia and 34 sex- and age-matched healthy controls swallowing a thin liquid were quantitatively analyzed using two-dimensional motion digitization. The measurements included the movement distances and velocities of the hyoid and larynx, and the maximal tilt angles and angular velocities of the epiglottis. All velocity variables were significantly decreased in the stroke patients compared to the controls. There was a significant difference in the maximal horizontal displacement of the larynx, but there were no significant differences in other displacements of the larynx, the maximal displacements of the hyoid bone, and the maximum tilt angle of the epiglottis between the two groups. The maximal tilt angle of the epiglottis was lower in the aspiration subgroup than in the no penetration/aspiration and penetration subgroups as well as the controls. The maximal tilt angle from the y axis showed a dichotomous pattern at 90° of the angle, and all 11 patients with an angle <90° showed either penetration or aspiration. In the ROC curve of the angle for prediction of aspiration, the area under the curve was 0.725 (95 % CI 0.557-0.892, P = 0.008). This study suggested that sluggish rather than decreased hyolaryngeal movements during swallowing are a remarkable feature of post-stroke dysphagia. The association of reduced epiglottic movement with the risk of aspiration in patients with post-stroke dysphagia was supported by the quantitative analysis.

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.

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....

Modified Standard Penetration Test–based Drilled Shaft Design Method for Weak Rocks (Phase 2 Study)

DOT National Transportation Integrated Search

2017-12-15

In this project, Illinois-specific design procedures were developed for drilled shafts founded in weak shale or rock. In particular, a modified standard penetration test was developed and verified to characterize the in situ condition of weak shales ...

A Gas-Actuated Projectile Launcher for High-Energy Impact Testing of Structures

NASA Technical Reports Server (NTRS)

Ambur, Damodar R.; Jaunky, Navin; Lawson, Robin E.; Knight, Norman F., Jr.; Lyle, Karen H.

1999-01-01

A gas-act,uated penetration device has been developed for high-energy impact testing of structures. The high-energy impact. t,estiiig is for experimental simulation of uncontained engine failures. The non-linear transient finite element, code LS-DYNA3D has been used in the numerical simula.tions of a titanium rectangular blade with a.n aluminum target, plate. Threshold velocities for different combinations of pitch and yaw angles of the impactor were obtained for the impactor-target, t8est configuration in the numerica.1 simulations. Complet,e penet,ration of the target plate was also simulat,ed numerically. Finally, limited comparison of analytical and experimental results is presented for complete penetration of the target by the impactor.

Effects of pore pressure and mud filtration on drilling rates in a permeable sandstone

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

Black, A.D.; DiBona, B.; Sandstrom, J.

1983-10-01

During laboratory drilling tests in a permeable sandstone, the effects of pore pressure and mud filtration on penetration rates were measured. Four water-base muds were used to drill four saturated sandstone samples. The drilling tests were conducted at constant borehole pressure with different back pressures maintained on the filtrate flowing from the bottom of the sandstone samples. Bit weight was also varied. Filtration rates were measured while drilling and with the bit off bottom and mud circulating. Penetration rates were found to be related to the difference between the filtration rates measured while drilling and circulating. There was no observedmore » correlation between standard API filtration measurements and penetration rate.« less

Effects of pore pressure and mud filtration on drilling rates in a permeable sandstone

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

Black, A.D.; Dearing, H.L.; DiBona, B.G.

1985-09-01

During laboratory drilling tests in a permeable sandstone, the effects of pore pressure and mud filtration on penetration rates were measured. Four water-based muds were used to drill four saturated sandstone samples. The drilling tests were conducted at constant borehole pressure while different backpressures were maintained on the filtrate flowing from the bottom of the sandstone samples. Bit weight was varied also. Filtration rates were measured while circulating mud during drilling and with the bit off bottom. Penetration rates were found to be related qualitatively to the difference between the filtration rates measured while drilling and circulating. There was nomore » observed correlation between standard API filtration measurements and penetration rate.« less