33 CFR 110.218 - Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. 110.218 Section 110.218 Navigation and Navigable Waters COAST... Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. (a) The anchorage grounds...

33 CFR 110.218 - Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. 110.218 Section 110.218 Navigation and Navigable Waters COAST... Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. (a) The anchorage grounds...

33 CFR 110.218 - Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. 110.218 Section 110.218 Navigation and Navigable Waters COAST... Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. (a) The anchorage grounds...

33 CFR 334.950 - Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean at San Clemente... REGULATIONS § 334.950 Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas. (a) The danger zones. (1) The waters of the Pacific Ocean within an area beginning at China Point Light...

33 CFR 334.921 - Pacific Ocean at San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean at San Clemente Island, Calif.; naval restricted area. 334.921 Section 334.921 Navigation and Navigable Waters CORPS OF....921 Pacific Ocean at San Clemente Island, Calif.; naval restricted area. (a) The area. All waters...

33 CFR 334.921 - Pacific Ocean at San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean at San Clemente Island, Calif.; naval restricted area. 334.921 Section 334.921 Navigation and Navigable Waters CORPS OF....921 Pacific Ocean at San Clemente Island, Calif.; naval restricted area. (a) The area. All waters...

33 CFR 334.950 - Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean at San Clemente... REGULATIONS § 334.950 Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas. (a) The danger zones. (1) The waters of the Pacific Ocean within an area beginning at China Point Light...

33 CFR 334.921 - Pacific Ocean at San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean at San Clemente Island, Calif.; naval restricted area. 334.921 Section 334.921 Navigation and Navigable Waters CORPS OF....921 Pacific Ocean at San Clemente Island, Calif.; naval restricted area. (a) The area. All waters...

33 CFR 334.950 - Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean at San Clemente... REGULATIONS § 334.950 Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas. (a) The danger zones. (1) The waters of the Pacific Ocean within an area beginning at China Point Light...

Humanities Education as a Pathway for Women in Regional and Rural Australia: Clemente Ballarat

ERIC Educational Resources Information Center

Gervasoni, Ann; Smith, Jeremy; Howard, Peter

2013-01-01

This paper provides insight into the experience of Clemente humanities education for six regional and rural Australian women living around Ballarat. Each took part in an audio-taped semi-structured interview which explored the impact that university study had on their lives. Their responses suggest that Clemente Ballarat was life-giving. The…

33 CFR 110.218 - Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. 110.218 Section 110.218 Navigation and Navigable Waters COAST... Pacific Ocean at San Clemente Island, Calif.; in vicinity of Wilson Cove. (a) The anchorage grounds...

33 CFR 334.920 - Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2010 CFR

2010-07-01

... of San Clemente Island, Calif.; naval restricted area. 334.920 Section 334.920 Navigation and... RESTRICTED AREA REGULATIONS § 334.920 Pacific Ocean off the east coast of San Clemente Island, Calif.; naval... vessels, other than Naval Ordnance Test Station craft, and those cleared for entry by the Naval Ordnance...

33 CFR 334.960 - Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean, San Clemente... REGULATIONS § 334.960 Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove. (a) The danger zone. The waters of the Pacific Ocean in an area about one-half mile off the west coast of San...

33 CFR 334.960 - Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean, San Clemente... REGULATIONS § 334.960 Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove. (a) The danger zone. The waters of the Pacific Ocean in an area about one-half mile off the west coast of San...

33 CFR 334.960 - Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean, San Clemente... REGULATIONS § 334.960 Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove. (a) The danger zone. The waters of the Pacific Ocean in an area about one-half mile off the west coast of San...

33 CFR 334.960 - Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pacific Ocean, San Clemente... REGULATIONS § 334.960 Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove. (a) The danger zone. The waters of the Pacific Ocean in an area about one-half mile off the west coast of San...

77 FR 29077 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To Downlist Three...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-16

...We, the U.S. Fish and Wildlife Service, announce our 12-month findings on a petition to reclassify San Clemente Island lotus, and San Clemente Island paintbrush under the Endangered Species Act are warranted and we propose to change the status of these two species from endangered to threatened. We also propose to correct the scientific and common names of San Clement Island lotus. We are also announcing our 12-month finding on a petition to reclassify San Clemente Island bush mallow is not warranted at this time, and therefore we are not proposing to change the status of this species. We are taking these actions as a result of a petition to reclassify these three species.

[Study on the influence of bioclogging on permeability of saturated porous media by experiments and models].

PubMed

Yang, Jing; Ye, Shu-jun; Wu, Ji-chun

2011-05-01

This paper studied on the influence of bioclogging on permeability of saturated porous media. Laboratory hydraulic tests were conducted in a two-dimensional C190 sand-filled cell (55 cm wide x 45 cm high x 1.28 cm thick) to investigate growth of the mixed microorganisms (KB-1) and influence of biofilm on permeability of saturated porous media under condition of rich nutrition. Biomass distributions in the water and on the sand in the cell were measured by protein analysis. The biofilm distribution on the sand was observed by confocal laser scanning microscopy. Permeability was measured by hydraulic tests. The biomass levels measured in water and on the sand increased with time, and were highest at the bottom of the cell. The biofilm on the sand at the bottom of the cell was thicker. The results of the hydraulic tests demonstrated that the permeability due to biofilm growth was estimated to be average 12% of the initial value. To investigate the spatial distribution of permeability in the two dimensional cell, three models (Taylor, Seki, and Clement) were used to calculate permeability of porous media with biofilm growth. The results of Taylor's model showed reduction in permeability of 2-5 orders magnitude. The Clement's model predicted 3%-98% of the initial value. Seki's model could not be applied in this study. Conclusively, biofilm growth could obviously decrease the permeability of two dimensional saturated porous media, however, the reduction was much less than that estimated in one dimensional condition. Additionally, under condition of two dimensional saturated porous media with rich nutrition, Seki's model could not be applied, Taylor's model predicted bigger reductions, and the results of Clement's model were closest to the result of hydraulic test.

The Hadean-Archaean Environment

PubMed Central

Sleep, Norman H.

2010-01-01

A sparse geological record combined with physics and molecular phylogeny constrains the environmental conditions on the early Earth. The Earth began hot after the moon-forming impact and cooled to the point where liquid water was present in ∼10 million years Subsequently, a few asteroid impacts may have briefly heated surface environments, leaving only thermophile survivors in kilometer-deep rocks. A warm 500 K, 100 bar CO2 greenhouse persisted until subducted oceanic crust sequestered CO2 into the mantle. It is not known whether the Earth's surface lingered in a ∼70°C thermophile environment well into the Archaean or cooled to clement or freezing conditions in the Hadean. Recently discovered ∼4.3 Ga rocks near Hudson Bay may have formed during the warm greenhouse. Alkalic rocks in India indicate carbonate subduction by 4.26 Ga. The presence of 3.8 Ga black shales in Greenland indicates that S-based photosynthesis had evolved in the oceans and likely Fe-based photosynthesis and efficient chemical weathering on land. Overall, mantle derived rocks, especially kimberlites and similar CO2-rich magmas, preserve evidence of subducted upper oceanic crust, ancient surface environments, and biosignatures of photosynthesis. PMID:20516134

Failure to obtain value enhancement by within-trial contrast in simultaneous and successive discriminations.

PubMed

Arantes, Joana; Grace, Randolph C

2008-02-01

The present research tested the generality of the "work ethic" effect described by Clement, Feltus, Kaiser, and Zentall (2000). In Experiment 1, we trained 10 pigeons on a pair of either simultaneous or successive discriminations. One discrimination followed a high-effort requirement (20 pecks to the center key) and the other followed a low-effort requirement (1 peck). Contrary to Clement et al.'s results, we found that preferences between the S+ and S- stimuli in transfer tests depended on the event that initiated the trial: Pigeons preferred the stimulus from the baseline discrimination whose initiating event was most dissimilar from that preceding the test trial. Preferences were similar but less extreme in the successive condition. In Experiment 2, we investigated whether test preferences depended on the amount of training. A total of 12 pigeons were trained on a pair of simultaneous discriminations, except that test sessions were scheduled after every three baseline sessions. Preferences increased across test sessions but were similar to those in Experiment 1. Together with Vasconcelos, Urcuioli, and Lionello-DeNolf (2007a), our study represents a second failure to replicate Clement et al.'s work ethic effect. The finding that preference depends on the event that initiates the test trial suggests that choice probes may not provide unambiguous assessments of stimulus value.

75 FR 42014 - Proposed Amendment of Class E Airspace; San Clemente, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

... Island Non- Directional Radio Beacon (NDB) at San Clemente Island NALF (Frederick Sherman Field) has made...: Eldon Taylor, Federal Aviation Administration, Operations Support Group, Western Service Center, 1601...

[Evaluation of fetal lung maturity using a modified lecithin-sphingomyelin determination and Clements' foam test].

PubMed

Neumann, G; Gartzke, J; Faber, G

1978-01-01

The modified thin layer chromatographic method for the determination of the phospholipids lecithin and sphingomyelin from amniotic fluid is useful in estimating fetal pulmonary maturity. The foam test of Clements is a simple rapid method for screening of suspicious cases of pregnancies at risk and of great value as bed side test even performing by the doctor. In comparing Clements-Test with thin layer chromatographic for L/S-Ratio determination we found a good correlation of 81,8% of all cases.

Longitudinal Evaluation of a Scale-Up Model for Teaching Mathematics with Trajectories and Technologies: Mechanisms of Persistence of Effects

ERIC Educational Resources Information Center

Clements, Douglas H.

2011-01-01

The author and her colleagues' TRIAD model (Sarama, Clements, Starkey, Klein, & Wakeley, 2008), including the "Building Blocks" curriculum, have significantly and substantially increased preschooler's mathematical competence, both in previous studies (Clements & Sarama, 2008, g = 1.07) and in their present, largest implementation…

Geoloogic slip on offshore San Clemente fault, Southern California, understated in GPS data

NASA Astrophysics Data System (ADS)

Legg, M. R.

2005-12-01

The San Clemente fault offshore southern California exhibits prominent geomorphic evidence of major late Quaternary right-slip. Like the San Andreas fault, where modern Pacific-North America transform motion is focused, the San Clemente fault stretches more than 700 km along the continental margin with a well-defined principal displacement zone (PDZ). Lateral offset is generally concentrated in a zone less than about 1 km wide, and linear seafloor fault scarps cutting across active submarine fans and basin-filling turbidites demonstrate Holocene activity. Dextral offset of middle Miocene circular crater structures suggest as much as 60 km of Neogene and younger displacement. Offset submarine fan depositional features suggest a rate of about 4-7 mm/yr of late Quaternary slip. Nearly 75 years of seismograph recording in southern California registered at least three moderate (M~6) earthquakes, activity which exceeds that of the Elsinore fault with a similar measured slip rate. Geodetic data based only on a few decades of GPS observations have been interpreted to show less than 1 mm/yr right-slip on the San Clemente fault, whereas larger rates, of about 5-10 mm/yr are described in the Inner Borderland between Catalina Island and the coast. Extrapolations of data from GPS stations on the Pacific Plate offshore Baja California also suggest larger rates west of San Clemente Island. Because there are few offshore locations (islands) for GPS observations, and San Clemente Island is likely within the broader zone of deformation of its namesake fault, these data miss the full slip rate. Seafloor observations from submersible discovered youthful fault scarps in turbidite muds that are inferred to represent large prehistoric earthquakes, (M~7). The potential for large offshore earthquakes, with tsunami generation that would affect the heavily populated adjacent coastal areas underscores the importance of resolving the slip rate and quantifying the hazard potential.

Accuracy of quadrat sampling in studying forest reproduction on cut-over areas

Treesearch

I. T. Haig

1929-01-01

The quadrat method, first introduced into ecological studies by Pound and Clements in i898, has been adopted by both foresters and ecologists as one of the most accurate means of studying the occurrence, distribution, and development of vegetation (Clements, '05; Weaver, '18). This method is unquestionably more precise than the descriptive method which it...

33 CFR 334.921 - Pacific Ocean at San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Island, Calif.; naval restricted area. 334.921 Section 334.921 Navigation and Navigable Waters CORPS OF....921 Pacific Ocean at San Clemente Island, Calif.; naval restricted area. (a) The area. All waters... be enforced by the Commander, Naval Base, San Diego, and such agencies as he/she shall designate. [50...

33 CFR 334.961 - Pacific Ocean, San Clemente Island, California, naval danger zone off the northwest shore.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Island, California, naval danger zone off the northwest shore. 334.961 Section 334.961 Navigation and... RESTRICTED AREA REGULATIONS § 334.961 Pacific Ocean, San Clemente Island, California, naval danger zone off... regulations in this section shall be enforced by the commander, Naval Base, San Diego, California, and such...

33 CFR 334.921 - Pacific Ocean at San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Island, Calif.; naval restricted area. 334.921 Section 334.921 Navigation and Navigable Waters CORPS OF....921 Pacific Ocean at San Clemente Island, Calif.; naval restricted area. (a) The area. All waters... be enforced by the Commander, Naval Base, San Diego, and such agencies as he/she shall designate. [50...

33 CFR 334.960 - Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Island, Calif.; naval danger zone off West Cove. 334.960 Section 334.960 Navigation and Navigable Waters... REGULATIONS § 334.960 Pacific Ocean, San Clemente Island, Calif.; naval danger zone off West Cove. (a) The... operations officer, Naval Ordnance Test Station, Pasadena Annex, Pasadena, California, will announce firing...

75 FR 28194 - Safety Zone; San Clemente 3 NM Safety Zone, San Clemente Island, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-20

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2009-0277] RIN 1625... inspection or copying at the Docket Management Facility (M-30), U.S. Department of Transportation, West... 1934, Executive Order 6897 transferred full ownership of SCI from the Department of Commerce to the...

Environmental Impact Statement for the New San Clemente Project, Monterey County, California - Regulatory Permit Application Number 16516S09. Appendices.

DTIC Science & Technology

1987-09-01

understanding of the water resources system. Operation CVSIM operates on a daily time-step and incorporates both surface and ground -water responses...subunits and calculates riparian evapotranspiration, pumpage, recharge, storage, and outflow. SEASID Operates Seaside coastal ground -water basin and...diversions. Reservoir effects included controlled releases to the river, spills, evaporation, and leakage. Ground -water flow in the upper watershed is

Contemporary Art Criticism and the Legacy of Clement Greenberg: Or, How Artwriting Earned Its Good Name

ERIC Educational Resources Information Center

Siedell, Daniel A.

2002-01-01

This essay sketches out the reasons for Clement Greenberg's influence and the relationship between his reception as a critic and the emergence of art criticism as a "discipline," a phenomenon that corresponds, as Amy Newman observes, with the early history of "Artforum". But it is much more than mere "correspondence." This essay also suggests,…

Keeping the Focus on Underserved Students, Privilege, and Power: A Reaction to Clements and Sarama

ERIC Educational Resources Information Center

Kitchen, Richard; Berk, Sarabeth

2017-01-01

In our response to Clements and Sarama (2017), we address the 5 issues that they identify as criticisms of our Research Commentary (Kitchen & Berk, 2016). As in our original commentary, we highlight concerns we have regarding the delivery of [computer-assisted instruction] CAI programs and potential misuses of CAI, particularly at Title I…

The Clemente Program and Calgary Alberta's Storefront 101: Intuitive Connection to the Traditions and Practices of Adult Education

ERIC Educational Resources Information Center

Groen, Janet

2005-01-01

Earl Shorris launched his presentation to 20 potential applicants for his newly developed humanities course directed toward the poor and disenfranchised in New York City. Since this inaugural course in New York, the Clemente Course has been launched in numerous centres across the United States, Canada, Australia, and Mexico. The course is named…

Mapping Vegetation Community Types in a Highly-Disturbed Landscape: Integrating Hiearchical Object-Based Image Analysis with Digital Surface Models

NASA Astrophysics Data System (ADS)

Snavely, Rachel A.

Focusing on the semi-arid and highly disturbed landscape of San Clemente Island, California, this research tests the effectiveness of incorporating a hierarchal object-based image analysis (OBIA) approach with high-spatial resolution imagery and light detection and range (LiDAR) derived canopy height surfaces for mapping vegetation communities. The study is part of a large-scale research effort conducted by researchers at San Diego State University's (SDSU) Center for Earth Systems Analysis Research (CESAR) and Soil Ecology and Restoration Group (SERG), to develop an updated vegetation community map which will support both conservation and management decisions on Naval Auxiliary Landing Field (NALF) San Clemente Island. Trimble's eCognition Developer software was used to develop and generate vegetation community maps for two study sites, with and without vegetation height data as input. Overall and class-specific accuracies were calculated and compared across the two classifications. The highest overall accuracy (approximately 80%) was observed with the classification integrating airborne visible and near infrared imagery having very high spatial resolution with a LiDAR derived canopy height model. Accuracies for individual vegetation classes differed between both classification methods, but were highest when incorporating the LiDAR digital surface data. The addition of a canopy height model, however, yielded little difference in classification accuracies for areas of very dense shrub cover. Overall, the results show the utility of the OBIA approach for mapping vegetation with high spatial resolution imagery, and emphasizes the advantage of both multi-scale analysis and digital surface data for accuracy characterizing highly disturbed landscapes. The integrated imagery and digital canopy height model approach presented both advantages and limitations, which have to be considered prior to its operational use in mapping vegetation communities.

33 CFR 334.920 - Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean off the east coast... RESTRICTED AREA REGULATIONS § 334.920 Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area. (a) The area. The waters of the Pacific Ocean within an area extending easterly from the...

33 CFR 334.920 - Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pacific Ocean off the east coast... RESTRICTED AREA REGULATIONS § 334.920 Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area. (a) The area. The waters of the Pacific Ocean within an area extending easterly from the...

33 CFR 334.920 - Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean off the east coast... RESTRICTED AREA REGULATIONS § 334.920 Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area. (a) The area. The waters of the Pacific Ocean within an area extending easterly from the...

33 CFR 334.920 - Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean off the east coast... RESTRICTED AREA REGULATIONS § 334.920 Pacific Ocean off the east coast of San Clemente Island, Calif.; naval restricted area. (a) The area. The waters of the Pacific Ocean within an area extending easterly from the...

STABILIZING CLOUD FEEDBACK DRAMATICALLY EXPANDS THE HABITABLE ZONE OF TIDALLY LOCKED PLANETS

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

Yang Jun; Abbot, Dorian S.; Cowan, Nicolas B., E-mail: abbot@uchicago.edu

2013-07-10

The habitable zone (HZ) is the circumstellar region where a planet can sustain surface liquid water. Searching for terrestrial planets in the HZ of nearby stars is the stated goal of ongoing and planned extrasolar planet surveys. Previous estimates of the inner edge of the HZ were based on one-dimensional radiative-convective models. The most serious limitation of these models is the inability to predict cloud behavior. Here we use global climate models with sophisticated cloud schemes to show that due to a stabilizing cloud feedback, tidally locked planets can be habitable at twice the stellar flux found by previous studies.more » This dramatically expands the HZ and roughly doubles the frequency of habitable planets orbiting red dwarf stars. At high stellar flux, strong convection produces thick water clouds near the substellar location that greatly increase the planetary albedo and reduce surface temperatures. Higher insolation produces stronger substellar convection and therefore higher albedo, making this phenomenon a stabilizing climate feedback. Substellar clouds also effectively block outgoing radiation from the surface, reducing or even completely reversing the thermal emission contrast between dayside and nightside. The presence of substellar water clouds and the resulting clement surface conditions will therefore be detectable with the James Webb Space Telescope.« less

The A-7E Software Requirements Document: Three Years of Change Data.

DTIC Science & Technology

1982-11-08

Washington DC: Naval Research Laboratory. 1982. Interface Specifications for the A-7E Shared Services Module NRL Memorandum Report. Forthcoming...function driver module (Clements 1981), specifications for the extended computer module (Britton et al. 1982), and specifications for the shared ... services module (Clements 1982). The projected completion date for the SCR project is September 1985. As of the end of 1981, approximately 10 man-years of

VizieR Online Data Catalog: Updated catalog of variable stars in globular clusters (Clement+ 2017)

NASA Astrophysics Data System (ADS)

Clement, C. M.

2017-02-01

This Catalogue is an update to Helen Sawyer Hogg's Third Catalogue on Variable Stars in Globular Clusters (1973, David Dunlap Observatory Publications, Volume 3, Number 6: 1973PDDO....3....6S; see Cat V/97; see also Clement+, 2001AJ....122.2587C). This catalogue is based on the individual cluster files downloaded on http://www.astro.utoronto.ca/~cclement/cat/listngc.html on the 01-Feb-2017. Later updates are indicated in clusters.dat; column "Update". (7 data files).

An Assessment of Fatigue Damage and Crack Growth Prediction Techniques (L’Evaluation de l’Endommagement en Fatigue et les Techniques de Prediction de la Propagation des Fissures)

DTIC Science & Technology

1994-03-01

reality the structure of even one individual aircraft consists of many bat- ches and the tens of thousand of cars of one type manufactured in even...generated neural network power spectral densities of surface pressures are used to augment existing data and then load an elastic finite clement...investigated for possible use in augmenting this information which is required for fatigue life calculations. Since empennage environments on fighter

Effects of Competition and Mode of Fire on Physiological Responses, Psychological Stress Reactions, and Shooting Performance

DTIC Science & Technology

1991-07-01

Alterations in serum cortisol and its binding characteristics in anorexia nervosa . J.urnal o•f Q n1raI £ndcrinaloag and M -bo.liam, Ui, 406-411. Clement...91 43. Comparison of Mean Pre-stress MAACL-R Depression Scores for SS Competition and SS Control Groups on Record-Fire Day With Those for Subjects in...independent non-stress contzol condition) .................. 92 5 44. Comparison of Mean Post-stress MAACL-R Depression Scores for SS Competition and SS

Evaluation of Radiation Exposure Hazard from Squaw Targets Used in Operations WIGWAM and HARDTACK-1

DTIC Science & Technology

2016-07-01

2011): Dove this on February 13, 2011. We thought it was a WWII US Sub but after diving it and looking at the video, I’m not sure what it is? No...DTRA Public Affairs, from Ned Madden of the OC Weekly, Costa Mesa, CA. April 21. Marco, P., 2015. “San Clemente Island’s Mystery Wreck ,” amateur...posts on Feb 18–21, 2011. http://www.rebreatherworld.com/showthread.php?37148-San-Clemente-Island-s- Mystery- Wreck . Accessed April 26, 2016 12

Chemical evolution and the preservation of organic compounds on Mars

NASA Technical Reports Server (NTRS)

Kanavarioti, Anastassia; Mancinelli, Rocco L.

1989-01-01

Several lines of evidence suggest that the environment on early Mars and early Earth were very similar. Since life is abundant on Earth, it seems likely that conditions on early Earth were conducive to chemical evolution and the origin of life. The similarity between early Mars and early Earth encourages the hypothesis that chemical evolution might have also occurred on Mars, but that decreasing temperatures and the loss of its atmosphere brought the evolution to a halt. The possibility of finding on Mars remnants of organic material dating back to this early clement period is addressed.

Author Correction: Tropical explosive volcanic eruptions can trigger El Niño by cooling tropical Africa.

PubMed

Khodri, Myriam; Izumo, Takeshi; Vialard, Jérôme; Janicot, Serge; Cassou, Christophe; Lengaigne, Matthieu; Mignot, Juliette; Gastineau, Guillaume; Guilyardi, Eric; Lebas, Nicolas; Robock, Alan; McPhaden, Michael J

2018-02-22

The original version of this Article omitted a reference to previous work in 'Mann, M.E., Cane, M.A., Zebiak, S.E., Clement, A., Volcanic and Solar Forcing of the Tropical Pacific Over the Past 1000 Years, J. Climate 18, 447-456 (2005)'. This has been added as reference 62 at the end of the fourth sentence of the fourth paragraph of the Introduction: 'Early studies using simple coupled ocean-atmosphere models 26 proposed that following volcano-induced surface cooling, upwelling in the eastern equatorial Pacific acting on a reduced vertical temperature contrast between the ocean surface and interior leads to anomalous warming in this region, thereby favouring El Niño development the following year 12, 27, 62 .' This has been corrected in the PDF and HTML versions of the Article.

Wind Power Plant Evaluation Naval Auxiliary Landing Field, San Clemente Island, California: Period of Performance 24 September 1999--15 December 2000

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

Olsen, T.L.; Gulman, P.J.; McKenna, E.

2000-12-11

The purpose of this report is to evaluate the wind power benefits and impacts to the San Clement Island wind power system, including energy savings, emissions reduction, system stability, and decreased naval dependence on fossil fuel at the island. The primary goal of the SCI wind power system has been to operate with the existing diesel power plant and provide equivalent or better power quality and system reliability than the existing diesel system. The wind system is intended to reduce, as far as possible, the use of diesel fuel and the inherent generation of nitrogen oxide emissions and other pollutants.

A steady state solution for ditch drainage problem with special reference to seepage face and unsaturated zone flow contribution: Derivation of a new drainage spacing eqaution

NASA Astrophysics Data System (ADS)

Yousfi, Ammar; Mechergui, Mohammed

2016-04-01

The seepage face is an important feature of the drainage process when recharge occurs to a permeable region with lateral outlets. Examples of the formation of a seepage face above the downstream water level include agricultural land drained by ditches. Flow problem to these drains has been investigated extensively by many researchers (e.g. Rubin, 1968; Hornberger et al. 1969; Verma and Brutsaert, 1970; Gureghian and Youngs, 1975; Vauclin et al., 1975; Skaggs and Tang, 1976; Youngs, 1990; Gureghian, 1981; Dere, 2000; Rushton and Youngs, 2010; Youngs, 2012; Castro-Orgaz et al., 2012) and may be tackled either using variably saturated flow models, or the complete 2-D solution of Laplace equation, or using the Dupuit-Forchheimer approximation; the most widely accepted methods to obtain analytical solutions for unconfined drainage problems. However, the investigation reported by Clement et al. (1996) suggest that accounting for the seepage face alone, as in the fully saturated flow model, does not improve the discharge estimate because of disregarding flow the unsaturated zone flow contribution. This assumption can induce errors in the location of the water table surface and results in an underestimation of the seepage face and the net discharge (e.g. Skaggs and Tang, 1976; Vauclin et al., 1979; Clement et al., 1996). The importance of the flow in the unsaturated zone has been highlighted by many authors on the basis of laboratory experiments and/or numerical experimentations (e.g. Rubin, 1968; Verma and Brutsaert, 1970; Todsen, 1973; Vauclin et al., 1979; Ahmad et al., 1993; Anguela, 2004; Luthin and Day, 1955; Shamsai and Narasimhan, 1991; Wise et al., 1994; Clement et al., 1996; Boufadel et al., 1999; Romano et al., 1999; Kao et al., 2001; Kao, 2002). These studies demonstrate the failure of fully saturated flow models and suggested that the error made when using these models not only depends on soil properties but also on the infiltration rate as reported by Kao et al. (2001). In this work, a novel solution based on theoretical approach will be adapted to incorporate both the seepage face and the unsaturated zone flow contribution for solving ditch drained aquifers problems. This problem will be tackled on the basis of the approximate 2D solution given by Castro-Orgaz et al. (2012). This given solution yields the generalized water table profile function with a suitable boundary condition to be determined and provides a modified DF theory which permits as an outcome the analytical determination of the seepage face. To assess the ability of the developed equation for water-table estimations, the obtained results were compared with numerical solutions to the 2-D problem under different conditions. It is shown that results are in fair agreement and thus the resulting model can be used for designing ditch drainage systems. With respect to drainage design, the spacings calculated with the newly derived equation are compared with those computed from the DF theory. It is shown that the effect of the unsaturated zone flow contribution is limited to sandy soils and The calculated maximum increase in drain spacing is about 30%. Keywords: subsurface ditch drainage; unsaturated zone; seepage face; water-table, ditch spacing equation

Direct thermal effects of the Hadean bombardment did not limit early subsurface habitability

NASA Astrophysics Data System (ADS)

Grimm, R. E.; Marchi, S.

2018-03-01

Intense bombardment is considered characteristic of the Hadean and early Archean eons, yet some detrital zircons indicate that near-surface water was present and thus at least intervals of clement conditions may have existed. We investigate the habitability of the top few kilometers of the subsurface by updating a prior approach to thermal evolution of the crust due to impact heating, using a revised bombardment history, a more accurate thermal model, and treatment of melt sheets from large projectiles (>100 km diameter). We find that subsurface habitable volume grows nearly continuously throughout the Hadean and early Archean (4.5-3.5 Ga) because impact heat is dissipated rapidly compared to the total duration and waning strength of the bombardment. Global sterilization was only achieved using an order of magnitude more projectiles in 1/10 the time. Melt sheets from large projectiles can completely resurface the Earth several times prior to ∼4.2 Ga but at most once since then. Even in the Hadean, melt sheets have little effect on habitability because cooling times are short compared to resurfacing intervals, allowing subsurface biospheres to be locally re-established by groundwater infiltration between major impacts. Therefore the subsurface is always habitable somewhere, and production of global steam or silicate-vapor atmospheres are the only remaining avenues to early surface sterilization by bombardment.

KSC-2014-2046

NASA Image and Video Library

2014-04-11

CAPE CANAVERAL, Fla. -- At the Marriott Courtyard Hotel in Cocoa Beach, Fla., Greg Clements, chief of Kennedy's Control and Data Systems Division and lead for the Engineering and Technology's Small Payload Integrated Testing Services, or SPLITS, line of business, speaks to participants in the 4th International Workshop on Lunar and Planetary Compact and Cryogenic Science and Technology Applications. Scientists, engineers and entrepreneurs interested in research on the moon and other planetary surfaces, recently participated in the Workshop. Taking place April 8-11, 2014, the event was designed to foster collaborative work among those interested in solving the challenges of building hardware, software and businesses interested in going back to the moon and exploring beyond. Photo credit: NASA/Daniel Casper

KSC-2014-2047

NASA Image and Video Library

2014-04-11

CAPE CANAVERAL, Fla. -- At the Marriott Courtyard Hotel in Cocoa Beach, Fla., Greg Clements, chief of Kennedy's Control and Data Systems Division and lead for the Engineering and Technology's Small Payload Integrated Testing Services, or SPLITS, line of business, speaks to participants in the 4th International Workshop on Lunar and Planetary Compact and Cryogenic Science and Technology Applications. Scientists, engineers and entrepreneurs interested in research on the moon and other planetary surfaces, recently participated in the Workshop. Taking place April 8-11, 2014, the event was designed to foster collaborative work among those interested in solving the challenges of building hardware, software and businesses interested in going back to the moon and exploring beyond. Photo credit: NASA/Daniel Casper

CURV 3: Characteristics and mission applications

NASA Astrophysics Data System (ADS)

Perkins, W. W.; Brady, L. K.

1984-03-01

The Cable-Controlled Underwater Recovery Vehicle (CURV) program was begun by NOSC for the specific purpose of developing economical systems to recover test ordnance at NOSC's Long Beach and San Clemente Island test ranges. CURV 3 is the latest in this series of tethered, unmanned, remotely controlled vehicles and its present capabilities far exceed the original CURV 1. Originally conceived for use as a search and recovery vehicle, CURV has evolved into a versatile and easily adaptable multipurpose work vehicle capable of performing search and recovery tasks as well as pursuing test, evaluation, exploration, and work projects. Basically, CURV is a composite of integrated subsystems including such items as propulsion, search and navigation, optics, hydraulics, and tools. Because it is unmanned and does not require life support or other complex support systems, CURV is able to perform most undersea tasks more economically and efficiently than maned systems. Also, since it is powered and controlled from the surface, CURV has a continuous, unlimited operating capability. Under emergency conditions, the vehicle can operate to 10,000-foot depths. CURV can be easily transported to any spot in the world. Upon arrival of the vehicle, control van, cable, and support gear can be mounted on a suitable ship of opportunity.

The physics, biology, and environmental ethics of making mars habitable.

PubMed

McKay, C P; Marinova, M M

2001-01-01

The considerable evidence that Mars once had a wetter, more clement, environment motivates the search for past or present life on that planet. This evidence also suggests the possibility of restoring habitable conditions on Mars. While the total amounts of the key molecules--carbon dioxide, water, and nitrogen--needed for creating a biosphere on Mars are unknown, estimates suggest that there may be enough in the subsurface. Super greenhouse gases, in particular, perfluorocarbons, are currently the most effective and practical way to warm Mars and thicken its atmosphere so that liquid water is stable on the surface. This process could take approximately 100 years. If enough carbon dioxide is frozen in the South Polar Cap and absorbed in the regolith, the resulting thick and warm carbon dioxide atmosphere could support many types of microorganisms, plants, and invertebrates. If a planet-wide martian biosphere converted carbon dioxide into oxygen with an average efficiency equal to that for Earth's biosphere, it would take > 100,000 years to create Earth-like oxygen levels. Ethical issues associated with bringing life to Mars center on the possibility of indigenous martian life and the relative value of a planet with or without a global biosphere.

The physics, biology, and environmental ethics of making mars habitable

NASA Technical Reports Server (NTRS)

McKay, C. P.; Marinova, M. M.

2001-01-01

The considerable evidence that Mars once had a wetter, more clement, environment motivates the search for past or present life on that planet. This evidence also suggests the possibility of restoring habitable conditions on Mars. While the total amounts of the key molecules--carbon dioxide, water, and nitrogen--needed for creating a biosphere on Mars are unknown, estimates suggest that there may be enough in the subsurface. Super greenhouse gases, in particular, perfluorocarbons, are currently the most effective and practical way to warm Mars and thicken its atmosphere so that liquid water is stable on the surface. This process could take approximately 100 years. If enough carbon dioxide is frozen in the South Polar Cap and absorbed in the regolith, the resulting thick and warm carbon dioxide atmosphere could support many types of microorganisms, plants, and invertebrates. If a planet-wide martian biosphere converted carbon dioxide into oxygen with an average efficiency equal to that for Earth's biosphere, it would take > 100,000 years to create Earth-like oxygen levels. Ethical issues associated with bringing life to Mars center on the possibility of indigenous martian life and the relative value of a planet with or without a global biosphere.

Loads of suspended sediment and nutrients from local nonpoint sources to the tidal Potomac River and Estuary, Maryland and Virginia, 1979-81 water years

USGS Publications Warehouse

Hickman, R. Edward

1987-01-01

Loads of suspended sediment, phosphorus, nitrogen, biochemical oxygen demand, and dissolved silica discharged to the tidal Potomac River and Estuary during the !979-81 water years from three local nonpoint sources have been calculated. The loads in rain falling directly upon the tidal water surface and from overflows of the combined sewer system of the District of Columbia were determined from available information. Loads of materials in the streamflow from local watersheds draining directly to the tidal Potomac River and Estuary downstream from Chain Bridge in Washington, D.C., were calculated from samples of streamflow leaving five monitored watersheds. Average annual yields of substances leaving three urban watersheds (Rock Creek and the Northwest and Northeast Branches of the Anacostia River) and the rural Saint Clements Creek watershed were calculated either by developing relationships between concentration and streamflow or by using the mean of measured concentrations. Yields calculated for the 1979-81 water years are up to 2.3 times period-of-record yields because of greater than average streamflow and stormflow during this 3-year period. Period-of-record yields of suspended sediment from the three urban watersheds and the Saint Clements Creek watershed do not agree with yields reported by other studies. The yields from the urban watersheds are 17 to 51 percent of yields calculated using sediment-concentration data collected during the 1960-62 water years. Previous studies suggest that this decrease is at least partly due to the imposition of effective sediment controls at construction sites and to the construction of two multipurpose reservoirs. The yield calculated for the rural Saint Clements Creek watershed is at least twice the yields calculated for other rural watersheds, a result that may be due to most of the samples of this stream being taken during the summer of the 1981 water year, a very dry period. Loads discharged from all local tributary watersheds to the tidal Potomac River and Estuary during the 1979-81 water years were calculated by applying to the unsampled watersheds the yields determined for the monitored watersheds. The resulting loads are 2.7 million megagrams of suspended sedi- ment, 3,100 megagrams of phosphorus, 14,000 megagrams of nitrogen, 74,000 megagrams of ultimate biochemical oxygen demand, and 68,000 megagrams of dissolved silica. The value for the load of sediment is probably an overestimate because the sediment yield calculated for the Saint Clements Creek watershed does not appear to be representative of rural watersheds. Summed, the loads discharged from all local nonpoint sources (local tributary watersheds, rainfall, and combined sewer overflows) to the tidal Potomac River and Estuary during the 1979-81 water years are 2.7 million megagrams of suspended sediment, 3,300 megagrams of phosphorus, 18,000 megagrams of nitrogen, 78,000 megagrams of ultimate biochemical oxygen demand, and 69,000 megagrams of dissolved silica. These loads accounted for 17 to 38 percent of the loads discharged by major sources during this period.

Mars in the late Noachian: Evolution of a habitable surface environment

NASA Astrophysics Data System (ADS)

Johnson, Sarah Stewart

2008-10-01

This dissertation addresses whether simple life forms might have existed on Mars during the late Noachian epoch, and whether those life forms, or their traces, can be detected today. It begins by analyzing the ancient Martian climate in light of new evidence that sulfur chemistry played a prominent role in the planet's early evolution. It finds that sulfur-induced greenhouse warming could have periodically heated the planet enough to support liquid water, thereby creating warm, wet, clement conditions. Moreover, it finds that those warming pulses, while short-lived over geologic time, may have persisted for hundreds of years. If sulfur helped create environmental conditions capable of hosting life, however, it also created conditions that were adverse to sustaining it. In particular, dissipation of sulfur volatiles cooled the climate, and sulfur rainout contributed to the acidity of Martian surface waters. The dissertation therefore proceeds to analyze the potential for persistence and detection of life in terrestrial environments with Mars-like characteristics. It first investigates the potential for detecting ancient life by searching for lipid biomarkers in sulfur-rich acid salt lakes, concluding that a variety of biomarkers may be more resistant to decay than previously believed. It then analyzes soil samples from permafrost, discovering the oldest independently authenticated viable organisms ever found, and positing low-level metabolic activity and DNA repair as a survival mechanism in ancient cells. Finally, the dissertation uses deep sequencing to examine prokaryotic diversity in a terrestrial Mars-like river characterized by low pH and high concentrations of iron and sulfur, with results considered in light of the implications for life detection approaches incorporating new, in situ "PCR in a chip" technology. The dissertation concludes by proposing future work, including the ultimate goal of developing a life detection instrument for Mars. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Astronomy and calendar reform at the curia of Pope Clement VI: a new source.

PubMed

Nothaft, C Philipp E

2017-01-01

The article introduces a previously unknown fourteenth-century treatise on computus and calendrical astronomy entitled Expositio kalendarii novi, whose author proposed elaborate solutions to the technical flaws inherent in the calendar used by the Roman Church. An analysis of verbal parallels to other contemporary works on the same topic makes it possible to establish that the Expositio was produced in the context of a calendar reform initiative led by Pope Clement VI in 1344/45 and that this anonymous text is probably identical to a 'great and laborious work' on the calendar that the monk Johannes de Termis prepared for the pope around this time. Its author strove to make an original contribution by extracting new astronomical parameters from both ancient and contemporary data, which made him arrive at an estimate of the length of the tropical year that was independent of the then-current Alfonsine Tables. With its suggestion to remove eleven days from the Julian calendar and to correct the calendar through modified leap-year rhythms and periodically adjusted sequences of lunar epacts, the proposal enshrined in the Expositio exhibits some remarkable similarities to the Gregorian reform of the calendar promulgated in 1582. Although its influence on the latter must remain a matter of speculation, the newly discovered text sheds a revealing light on the history of medieval calendar reform debates and on the mathematical sciences practiced at the Avignon court of Clement VI.

Serpentinite and the dawn of life

PubMed Central

Sleep, Norman H.; Bird, Dennis K.; Pope, Emily C.

2011-01-01

Submarine hydrothermal vents above serpentinite produce chemical potential gradients of aqueous and ionic hydrogen, thus providing a very attractive venue for the origin of life. This environment was most favourable before Earth's massive CO2 atmosphere was subducted into the mantle, which occurred tens to approximately 100 Myr after the moon-forming impact; thermophile to clement conditions persisted for several million years while atmospheric pCO2 dropped from approximately 25 bar to below 1 bar. The ocean was weakly acid (pH ∼ 6), and a large pH gradient existed for nascent life with pH 9–11 fluids venting from serpentinite on the seafloor. Total CO2 in water was significant so the vent environment was not carbon limited. Biologically important phosphate and Fe(II) were somewhat soluble during this period, which occurred well before the earliest record of preserved surface rocks approximately 3.8 billion years ago (Ga) when photosynthetic life teemed on the Earth and the oceanic pH was the modern value of approximately 8. Serpentinite existed by 3.9 Ga, but older rocks that might retain evidence of its presence have not been found. Earth's sequesters extensive evidence of Archaean and younger subducted biological material, but has yet to be exploited for the Hadean record. PMID:21930576

Life on Mars

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; Cuzzi, Jeffrey (Technical Monitor)

1996-01-01

Although the Viking results may indicate that Mars has no life today, the possibility exists that Mars may hold the best record of the events that led to the origin of life. There is direct geomorphological evidence that in the past Mars had large amounts of liquid water on its surface. Atmospheric models would suggest that this early period of hydrological activity was due to the presence of a thick atmosphere and the resulting warmer temperatures. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. If Mars did maintain a clement environment for longer than it took for life to originate on Earth, then the question of the origin of life on Mars follows naturally.

The diagnosis of the cause of the death of Venerina.

PubMed

Mazzotti, Giovanni; Falconi, Mirella; Teti, Gabriella; Zago, Michela; Lanari, Marcello; Manzoli, Francesco A

2010-02-01

Venerina (little Venus) is the name given to a wax model representing a pregnant young woman that was created in Florence (Italy) by Clemente Susini (1754-1814) in 1782. It is currently located in the historic Science Museum of the University of Bologna. The model was constructed so as to enable removal of the thoracic and abdominal walls and various organs, exposing the heart, diaphragm and an opened uterus with a well-developed fetus. The woman is small, about 145 cm (4' 9') tall and of delicate build; she looks like a teenage girl. We know that Clemente Susini worked directly with the cadaver and copied the anatomical preparation exactly. This artist often represented the true structure using a wax mould; the existence of two other versions of this specimen suggests that this model was made in this way. Therefore, Venerina's body may be a faithful representation of a young woman who died while pregnant. Observation of the body confirms that the organs are normal, except for the heart and great vessels. The walls of both ventricles are of equal thickness and the ventricles themselves of approximately equal size. The arch of the aorta and the enlarged pulmonary trunk are connected by a short duct about 3.5 mm in diameter. If this structure represents an open arterial duct, we can deduce that the two ventricles worked under the same conditions of blood pressure, hence their equal wall thickness. If the young woman died from this congenital disease, the cause of death has been diagnosed on a wax model of her body after more than two centuries.

Systems Modeling for Crew Core Body Temperature Prediction Postlanding

NASA Technical Reports Server (NTRS)

Cross, Cynthia; Ochoa, Dustin

2010-01-01

The Orion Crew Exploration Vehicle, NASA s latest crewed spacecraft project, presents many challenges to its designers including ensuring crew survivability during nominal and off nominal landing conditions. With a nominal water landing planned off the coast of San Clemente, California, off nominal water landings could range from the far North Atlantic Ocean to the middle of the equatorial Pacific Ocean. For all of these conditions, the vehicle must provide sufficient life support resources to ensure that the crew member s core body temperatures are maintained at a safe level prior to crew rescue. This paper will examine the natural environments, environments created inside the cabin and constraints associated with post landing operations that affect the temperature of the crew member. Models of the capsule and the crew members are examined and analysis results are compared to the requirement for safe human exposure. Further, recommendations for updated modeling techniques and operational limits are included.

Systematic Eclectic Models.

ERIC Educational Resources Information Center

Mahalik, James R.

1990-01-01

Presents and evaluates four systematic eclectic models of psychotherapy: Beutler's eclectic psychotherapy; Howard, Nance, and Myers' adaptive counseling and therapy; Lazarus' multimodal therapy; and Prochaska and DiClemente's transtheoretical approach. Examines support for these models and makes conceptual and empirical recommendations.…

4. VIEW SHOWING OUTLET GATE WHEEL AND STEM, LOOKING NORTH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW SHOWING OUTLET GATE WHEEL AND STEM, LOOKING NORTH - High Mountain Dams in Upalco Unit, Clements Lake Dam, Ashley National Forest, 6.5 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

Detail view of the west elevation entrance door, showing the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail view of the west elevation entrance door, showing the door knocker & house numbers (Duplicate view of HABS DC-832-3) - Clements-de Sibour House, 1539 Twenty-ninth Street, Northwest, Washington, District of Columbia, DC

Uderstanding Snowball Earth Deglaciation

NASA Astrophysics Data System (ADS)

Abbot, D. S.

2012-12-01

Earth, a normally clement planet comfortably in its star's habitable zone, suffered global or nearly global glaciation at least twice during the Neoproterozoic era (at about 635 and 710 million years ago). Viewed in the context of planetary evolution, these pan-global glaciations (Snowball Earth events) were extremely rapid, lasting only a few million years. The dramatic effect of the Snowball Earth events on the development of the planet can be seen through their link to rises in atmospheric oxygen and evolutionary innovations. These potential catastrophes on an otherwise clement planet can be used to gain insight into planetary habitability more generally. Since Earth is not currently a Snowball, a sound deglaciation mechanism is crucial for the viability of the Snowball Earth hypothesis. The traditional deglaciation mechanism is a massive build up of CO2 due to reduced weathering during Snowball Earth events until tropical surface temperatures reach the melting point. Once initiated, such a deglaciation might happen on a timescale of only dozens of thousands of years and would thrust Earth from the coldest climate in its history to the warmest. Therefore embedded in Snowball Earth events is an even more rapid and dramatic environmental change. Early global climate model simulations raised doubt about whether Snowball Earth deglaciation could be achieved at a CO2 concentration low enough to be consistent with geochemical data, which represented a potential challenge to the Snowball Earth hypothesis. Over the past few years dust and clouds have emerged as the essential missing additional processes that would allow Snowball Earth deglaciation at a low enough CO2 concentration. I will discuss the dust and cloud mechanisms and the modeling behind these ideas. This effort is critical for the broader implications of Snowball Earth events because understanding the specific deglaciation mechanism determines whether similar processes could happen on other planets.

36 CFR 1275.64 - Reproduction of tape recordings of Presidential conversations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... located in Washington, DC; Camp David, MD; Key Biscayne, FL; or San Clemente, CA; and (3) Were recorded... which have been identified as private or personal and which have been transferred to the Nixon estate in...

36 CFR 1275.64 - Reproduction of tape recordings of Presidential conversations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... located in Washington, DC; Camp David, MD; Key Biscayne, FL; or San Clemente, CA; and (3) Were recorded... which have been identified as private or personal and which have been transferred to the Nixon estate in...

33 CFR 165.1131 - Security Zone: Wilson Cove, San Clemente Island, California.

Code of Federal Regulations, 2014 CFR

2014-07-01

... zone is prohibited unless authorized by the Captain of the Port, San Diego, California. Section 165.33 also contains other general requirements. [COTP San Diego Reg. 87-04, 52 FR 18230, May 14, 1987...

33 CFR 165.1131 - Security Zone: Wilson Cove, San Clemente Island, California.

Code of Federal Regulations, 2013 CFR

2013-07-01

... zone is prohibited unless authorized by the Captain of the Port, San Diego, California. Section 165.33 also contains other general requirements. [COTP San Diego Reg. 87-04, 52 FR 18230, May 14, 1987...

33 CFR 165.1131 - Security Zone: Wilson Cove, San Clemente Island, California.

Code of Federal Regulations, 2011 CFR

2011-07-01

... zone is prohibited unless authorized by the Captain of the Port, San Diego, California. Section 165.33 also contains other general requirements. [COTP San Diego Reg. 87-04, 52 FR 18230, May 14, 1987...

33 CFR 165.1131 - Security Zone: Wilson Cove, San Clemente Island, California.

Code of Federal Regulations, 2012 CFR

2012-07-01

... zone is prohibited unless authorized by the Captain of the Port, San Diego, California. Section 165.33 also contains other general requirements. [COTP San Diego Reg. 87-04, 52 FR 18230, May 14, 1987...

33 CFR 165.1131 - Security Zone: Wilson Cove, San Clemente Island, California.

Code of Federal Regulations, 2010 CFR

2010-07-01

... zone is prohibited unless authorized by the Captain of the Port, San Diego, California. Section 165.33 also contains other general requirements. [COTP San Diego Reg. 87-04, 52 FR 18230, May 14, 1987...

Interpreting the paleozoogeography and sea level history of thermally anomalous marine terrace faunas: a case study from the the Last Interglacial Complex of San Clemente Island, California

USGS Publications Warehouse

Muhs, Daniel R.; Groves, Lindsey T.; Schumann, R. Randall

2014-01-01

Marine invertebrate faunas with mixtures of extralimital southern and extralimital northern faunal elements, called thermally anomalous faunas, have been recognized for more than a century in the Quaternary marine terrace record of the Pacific Coast of North America. Although many mechanisms have been proposed to explain this phenomenon, no single explanation seems to be applicable to all localities where thermally anomalous faunas have been observed. Here, we describe one such thermally anomalous fossil fauna that was studied on the second emergent marine terrace at Eel Point on San Clemente Island. The Eel Point terrace complex is a composite feature, consisting of a narrow upper bench (terrace 2a) and a broader lower bench (terrace 2b). Terrace 2b, previously dated from ~128 ka to ~114 ka, was thought to date solely to marine isotope stage (MIS) 5.5, representing the peak of the last interglacial period. Nevertheless, the fauna contains an extralimital northern species and several northward-ranging species, as well as an extralimital southern species and several southward-ranging species. Similar faunas with thermally anomalous elements have also been reported from San Nicolas Island, Point Loma (San Diego County), and Cayucos (San Luis Obispo County), California. U-series dating of corals at those localities shows that the thermally anomalous faunas may be the result of mixing of fossils from both the ~100-ka (cool-water) and the ~120-ka (warm-water) sea level high stands. Submergence, erosion, and fossil mixing of the ~120-ka terraces by the ~100-ka high-sea stand may have been possible due to glacial isostatic adjustment (GIA) effects on North America, which could have resulted in a higher-than-present local sea level stand at ~100 ka. The terrace elevation spacing on San Clemente Island is very similar to that on San Nicolas Island, and we hypothesize that a similar mixing took place on San Clemente Island. Existing fossil records from older terraces elsewhere in California also show thermally anomalous elements, indicating that the scenario presented here for the last interglacial complex may have applicability to much of the marine Quaternary record for the Pacific Coast.

36 CFR § 1275.64 - Reproduction of tape recordings of Presidential conversations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... located in Washington, DC; Camp David, MD; Key Biscayne, FL; or San Clemente, CA; and (3) Were recorded... which have been identified as private or personal and which have been transferred to the Nixon estate in...

ANALYSIS OF ESSENTIAL NUCLEAR REACTOR MATERIALS

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

Rodden, C.J.

1964-01-01

This book is intended as a laboratory reference tool. The separate book chapters have been written by workers in the various fields covered, with a couple written by the contributing editor, Clement J. Rodden. The chapters were abstracted separately for the database.

33 CFR 334.950 - Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas.

Code of Federal Regulations, 2010 CFR

2010-07-01

... danger zones. (1) The waters of the Pacific Ocean within an area beginning at China Point Light... beginning at China Point Light; extending in a direction of 181 degrees true, 2.0 nautical miles; thence 303...

33 CFR 334.950 - Pacific Ocean at San Clemente Island, California; Navy shore bombardment areas.

Code of Federal Regulations, 2011 CFR

2011-07-01

... danger zones. (1) The waters of the Pacific Ocean within an area beginning at China Point Light... beginning at China Point Light; extending in a direction of 181 degrees true, 2.0 nautical miles; thence 303...

Man of Fire.

ERIC Educational Resources Information Center

Phipps, Helene Juarez

1993-01-01

The themes of Jose Clemente Orozco's murals, several of which are found on U.S. college campuses, are as relevant today as they were during the Mexican Revolution. Orozco (1883-1949) painted the world as he saw it, portraying corruption, violence, and man's inhumanity to man. (LP)

Second Generation Product Line Engineering Takes Hold in the DoD

DTIC Science & Technology

2014-01-01

Feature- Oriented Domain Analysis ( FODA ) Feasibility Study” (CMU/SEI-90- TR-021, ADA235785). Pittsburgh, PA: Software Engineering Institute...software product line engineering and software architecture documentation and analysis . Clements is co-author of three practitioner-oriented books about

Geomorphic and Ecological Issues in Removal of Sediment-Filled Dams in the California Coast Ranges (Invited)

NASA Astrophysics Data System (ADS)

Kondolf, G. M.; Oreilly, C.

2010-12-01

Water-supply reservoirs in the actively eroding California Coast Ranges are vulnerable to sediment filling, thus creating obsolete impounding dams (Minear & Kondolf 2009). Once full of sediment, there is more impetus to remove dams for public safety and fish passage, but managing accumulated sediments becomes a dominant issue in dam removal planning. We analyzed the planning process and sediment management analyses for five dams, all of which have important ecological resources but whose dam removal options are constrained by potential impacts to downstream urban populations. Ringe Dam on Malibu Ck, Matilija Dam on the Ventura River, Searsville Dam on San Francisquito Ck, and Upper York Creek Dam on York Ck cut off important habitat for anadromous steelhead trout (Oncorhynchus mykiss). San Clemente Dam on the Carmel River has a working fish ladder, but only some of the migratory steelhead use it. By virtue of having filled with sediment, all five dams are at greater risk of seismic failure. San Clemente Dam is at greater risk because its foundation is on alluvium (not bedrock), and the poor-quality concrete in Matilija Dam is deteriorating from an akali-aggregate reaction. Simply removing the dams and allowing accumulated sediments to be transported downstream is not an option because all these rivers have extremely expensive houses along downstream banks and floodplains, so that allowing the downstream channel to aggrade with dam-dervied sediments could expose agencies to liability for future flood losses. Analyses of potential sediment transport have been based mostly on application of tractive force models, and have supported management responses ranging from in-situ stabilization (San Clemente and Matilija) to removal of stored sediment (York) to annual dredging to maintain capacity and prevent sediment passing over the dam (proposed for Searsville).

Fostering More Vibrant Schools

ERIC Educational Resources Information Center

Tschannen-Moran, Megan; Clement, Davis

2018-01-01

Drawing on their research in creating the Vibrant School Scale, Megan Tschannen-Moran and Davis Clement describe the three characteristics of vibrant schools: enlivened minds, emboldened voices, and playful learning. The authors also detail a four-step, strengths-based process called appreciative inquiry that can help school members have…

TRANSPORT AND DEPOSITION OF NANO-SIZE PARTICLES IN THE UPPER HUMAN RESPIRATORY AIRWAYS

EPA Science Inventory

TRANSPORT AND DEPOSITION OF NANO-SIZE PARTICLES IN THE UPPER HUMAN RESPIRATORY AIRWAYS. Zhe Zhang*, Huawei Shi, Clement Kleinstreuer, Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695-7910; Chong S. Kim, National Health and En...

Hot Ideas. A Mathematical Response to a Piece of Text

ERIC Educational Resources Information Center

Grey, Melinda

2005-01-01

Children's literature can enhance mathematics lessons by providing a meaningful context, demonstrating that mathematics develops from human experiences and contributes an aesthetic dimension to learning mathematics. Written as a series of real life inspired snapshots of mathematical thinking, "Counting on Frank" (Rod Clement, 1990)…

The Preschool Rating Instrument for Science and Mathematics (PRISM)

ERIC Educational Resources Information Center

Brenneman, Kimberly; Stevenson-Garcia, Judi; Jung, Kwanghee; Frede, Ellen

2011-01-01

Until recently, few valid and reliable assessments were available to measure young children's mathematics and science learning in a "comprehensive" way. Now, a number of mathematics assessments have been developed and subjected to testing (Klein, Starkey, & Wakeley, 2000; Ginsburg, 2008; Clements & Sarama, 2008), and progress has…

Application of Computer Tomography for Life Detection

NASA Technical Reports Server (NTRS)

Tsapin, A.; Nealson, K.

2001-01-01

Perhaps one of the most fundamentally difficult challenges facing those who would search for life is that of scale determination. Spatial scales of life on Earth range over more than 15 orders of magnitude in mass and volume, and more than 8 orders of magnitude in 2 dimensional space. If the distribution of life is sparse in comparison to the background on which it is found, then the choice of the right scale is critical to finding that life. But how does one identify the proper scale? To put this in other words, how does one recognize the "haystacks" in which the needles (biosignatures and evidence of life) might be most profitably searched for? The problem is further exacerbated when conditions get extreme because much of the life moves from the clement surface environment into the pores and more clement environments inside of rocks, minerals and soils. Once encased in their lithic homes, these microbes become nearly impossible to study by standard techniques because of the opacity of the rocks. It is this problem that we propose to address in the work proposed here. Computer Tomography (CT) has been a very valuable tool in medicine, where the best resolution available has typically been of the order of about 0.5 mm. However, to adapt the approach for life detection of microbial endoliths, the resolution needs to be moved to the micrometer and even submicrometer levels. Thus for the studies proposed here, we begin with a commercially available instrument that can yield resolution of approximately 10 micrometers. The rational for this is twofold: first, this is the "state of the art" in laboratory instruments; and second, that while the usual size of a microbial cell is about 1 micron, microorganisms tend to live in communities that usually exceed the 10 micrometer size range. The resolution also depends on the sample size itself, so having a small lab instrument into which small samples can be placed will be beneficial to the resolution. We have now used several different CT systems, beginning with the medical scanners (Arcadia CT group) for the detection of layered communities in sandstone rocks from Antarctica. Even this crude instrument was able to point to the areas of the rock that were dominated by microbial populations - this provides the critical first information that says, "Go back and look at these sites with other methods." We showed that without sample preparation or destruction it was possible to gain knowledge as to the presence of density differences suggestive of life.

African American Girls' Descriptions of Life in High-Risk Neighborhoods

ERIC Educational Resources Information Center

Kruger, Ann Cale; Zabek, Faith; Collins, Staeshe; Harper, Erin A.; Hamilton, Chela; McGee, Miriam Chitescu; Perkins, Catherine; Meyers, Joel

2016-01-01

In disadvantaged neighborhoods African American girls are at elevated risk for exposure to violence and sexualization (Miller, 2008; Salazar, Wingood, DiClemente, Lan, & Harrington, 2004). Preventive interventions can promote resilience by supporting capacities such as social decision making and self-understanding (Masten, 2001). We report on…

Abstract Numeric Relations and the Visual Structure of Algebra

ERIC Educational Resources Information Center

Landy, David; Brookes, David; Smout, Ryan

2014-01-01

Formal algebras are among the most powerful and general mechanisms for expressing quantitative relational statements; yet, even university engineering students, who are relatively proficient with algebraic manipulation, struggle with and often fail to correctly deploy basic aspects of algebraic notation (Clement, 1982). In the cognitive tradition,…

Transportation Research Fueled by Academia | News | NREL

Science.gov Websites

. Interested in furthering their research and education with the vast resources available at NREL, university researchers who are currently teaching include Senior Research Engineer Adam Duran, who has a senior capstone more transportation researchers-Yi Hou, Clement Rames, and Josh Sperling-are currently teaching an

No safety in numbers

Treesearch

Steven R. Beissinger; Curtis H. Flather; Gregory D. Hayward; Philip A. Stephens

2011-01-01

Clements et al. (Front Ecol Environ 2011; 9[9]: 521-525) proposed a single metric that describes a "species' ability to forestall extinction" (referred to by the acronym "SAFE") as a "scientifically defendable rule of thumb for when complete demographic data are unavailable" to rank the relative threat status of a species. SAFE is...

AEROSOL DEPOSITION EFFICIENCIES AND UPSTREAM RELEASE POSITIONS FOR DIFFERENT INHALATION MODES IN AN UPPER BRONCHIAL AIRWAY MODELS

EPA Science Inventory

Aerosol Deposition Efficiencies and Upstream Release Positions for Different Inhalation Modes in an Upper Bronchial Airway Model

Zhe Zhang, Clement Kleinstreuer, and Chong S. Kim

Center for Environmental Medicine and Lung Biology, University of North Carolina at Ch...

The Social Reality of Ethnic America.

ERIC Educational Resources Information Center

Gomez, Rudolph, Ed.; And Others

The contents of this compendium are organized in four parts, as follows: Part 1, "Blacks in Transition: An Overview of Afro-Americans," includes: "Introduction," Clement Cottingham, Jr.; "The New Negro," Nathan I. Huggins; "Political Change in the Negro Ghetto, 1900-1940's," Martin Kilson; "Minority Group Psychology: Implications for Social…

Pesticide Avoidance Behavior in Anopheles albimanus, a Malaria Vectorin Central and South America

DTIC Science & Technology

1995-07-11

Clements, A.N. 1992. The Bjoloey of MOSQuitoes. Volume 1. Development, nutrition , and reproduction. Chapman & Hall, 509 pp. EL-Khatib. Z.l...WHO 29(suppl): 121-126. Hoffman, C.C. 1934. Contribucion al conocimiento del paludismo en Ja peninsula de Yucatan . Boletia dellnstituto de

Chinese College Students' Physical Activity Correlates and Behavior: A Transtheoretical Model Perspective

ERIC Educational Resources Information Center

Xiong, Shanying; Li, Xianxiong; Tao, Kun; Zeng, Nan; Ayyub, Mohammad; Peng, Qingwen; Yan, Xiaoni; Wang, Junli; Wu, Yizhong; Lei, Mingzhi

2017-01-01

Guided by the Transtheoretical Model (Prochaska & DiClemente, 1982), this study investigated the differences of physical activity levels and correlates (i.e., self-efficacy, decisional balance, process of change) across different stages of change levels among Chinese college students. The relationships between students' physical activity…

Science Fiction: Today and Tomorrow.

ERIC Educational Resources Information Center

Bretnor, Reginald, Ed.

A critical symposium on science fiction, this book features essays (by Ben Bova, Frederik Pohl, George Zebrowski, Frank Herbert, Theodore Sturgeon, Alan E. Nourse, Thomas N. Scortia, Reginald Bretnor, James Gunn, Alexei and Cory Panshin, Poul Anderson, Hal Clement, Anne McCaffrey, Gordon R. Dickson, and Jack Williamson) dealing with such subjects…

Host genotype and hypersensitive reaction influence population levels of Xanthomonas campestris pv. vitians in lettuce

USDA-ARS?s Scientific Manuscript database

Population dynamics of Xanthomonas campestris pv. vitians spray inoculated on or infiltrated into lettuce leaves were monitored on cultivars that were well characterized for resistance or susceptibility to the pathogen. In general, population growth was greater for susceptible (Clemente, Salinas 88,...

75 FR 42431 - Onyx Specialty Papers, Inc; Notice Soliciting Applications

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

... Papers, Inc; Notice Soliciting Applications July 14, 2010. On April 29, 2009, Onyx Specialty Papers, Inc... is located in the basement of MeadWestvaco's paper mill. There are no transmission lines associated... information from the licensee, please contact Mr. John Clements, Counsel for Onyx Specialty Papers, Inc., Van...

Characterization of the Navy Fan Channel-to-Lobe Transition: Geomorphology, Gradient, and Structure Imaged through High-Resolution AUV Bathymetry

NASA Astrophysics Data System (ADS)

Carvajal, C.; Paull, C. K.; Caress, D. W.; Anderson, K.; Lundsten, E. M.; Gwiazda, R.; Fildani, A.; Dykstra, M.; McGann, M.; Maier, K. L.; Herguera, J. C.

2016-12-01

Channel to lobe transition zones (CLTZ) are elusive sectors of the seafloor. They record complex interactions between sediment-gravity flows, flow confinement, and gradient that can result in contrasting geomorphologies. If present, structural controls can add additional intricacies. We illustrate such complexities in the Navy Fan CLTZ offshore California/Mexico using AUV-collected high-resolution (1x1x0.25 m) bathymetry and chirp profiles. The AUV bathymetry images the fine scale details of the seafloor, otherwise unresolved in surface-ship-mounted multibeam bathymetry. Three morphological areas standout that in a direction transverse to sediment transport are: 1) An unconfined area with variable but overall steep gradients (0.5o-1.7o), and considerable erosion shown by numerous large scours that truncate underlying strata. These scours are elongate (<500x180 m), deep (<18 m), asymmetric (steeper proximally), and more prominent along steeper gradients; 2) An area of moderate confinement along a smoother, gentler gradient (0.2o-0.5o; 0.9o locally). This area is 8 km long with a channel (WxD: 233x11 m) that transitions basinwards to low confinement (WxD: 1000x4 m); and 3) An area with an escarpment (<25 m high, <19o) and ridge of the San Clemente Fault. We hypothesize that the erosional morphologies of the unconfined areas reflect swifter turbidity currents due to high gradients, which resulted from relief along the San Clemente Fault and probably from differential seafloor aggradation. In the moderate confinement area, the smoother and gentler seafloor may be related to more efficient sediment dispersal able to transfer/deposit sediment to heal structural relief (though not completely) while avoiding significant local aggradation, hence preventing major gradient build up. In the faulted area, the steep and prominent structure reroutes the sediments. The findings of this study have broad application to any seafloor areas with rapid changes of gradient.

Information Technology Challenges Facing the Strategic Leaders of Homeland Security in the 21st Century

DTIC Science & Technology

2004-05-03

A special thanks to all of these folks (Glenn Starnes, Lee Gutierrez, Bill Rapp, Joel Hillison, Carlos Gomez, Steve Fraunfelter, Janie Hopkins, Dave ...DiClemente, Joe Nunez, John Bonin , and Steve Nerheim). viii INFORMATION TECHNOLOGY CHALLENGES FACING THE STRATEGIC LEADERS OF HOMELAND SECURITY IN THE 21ST

The Transtheoretical Model's Stages and Processes of Change and Their Relation to Premature Termination.

ERIC Educational Resources Information Center

Smith, Kevin J., And Others

1995-01-01

Explores the issue of premature termination of therapy using the client readiness variables reflected in the stages and processes of change and proposed in Prochaska and DiClemente's transtheoretical model. This study used these variables to distinguish between premature and nonpremature terminators in a college counseling. Results indicated that…

Moving Towards Gray: Art Therapy and Ambivalence in Substance Abuse Treatment

ERIC Educational Resources Information Center

Horay, Brian J.

2006-01-01

Although some consider the 12-step method of Alcoholics Anonymous to be the treatment of choice for people struggling with substance abuse, differing approaches have been developed within the area of addictions. Motivational interviewing (Miller & Rollnick, 2002), enacted within a stages-of change model (DiClemente & Velasquez, 2002), seeks to…

The Determination of Heat Capacity Ratios in a Simple Open System

ERIC Educational Resources Information Center

Holden, Glen L.

2007-01-01

A virtually closed system is treated as open and compared to known results. The classic experiment of Clement and Desormes provides the conceptual framework for this open system approach in determining the molar heat capacity ratios, lambda. This alternate view, extends the theoretical treatment beyond the first law of thermodynamics for closed…

IFLA General Conference, 1986. Management and Technology Division. Section: Conservation. Papers.

ERIC Educational Resources Information Center

International Federation of Library Associations and Institutions, The Hague (Netherlands).

This document contains three papers on conservation which were presented at the 1986 International Federation of Library Associations (IFLA) conference. In "The IFLA Conservation Section and the Core Programme for Preservation (PAC)," David W. G. Clements of the United Kingdom outlines the background of the Core Programme on Preservation…

NEW SPECIES OF PARALOMIS (DECAPODA, ANOMURA, LITHODIDAE) FROM A SUNKEN WHALE CARCASS IN THE SAN CLEMENTE BASIN OF SOUTHERN CALIFORNIA. (U915626)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Adapting the Transtheoretical Model of Change to the Bereavement Process

ERIC Educational Resources Information Center

Calderwood, Kimberly A.

2011-01-01

Theorists currently believe that bereaved people undergo some transformation of self rather than returning to their original state. To advance our understanding of this process, this article presents an adaptation of Prochaska and DiClemente's transtheoretical model of change as it could be applied to the journey that bereaved individuals…

Math, Science, and Technology in the Early Grades

ERIC Educational Resources Information Center

Clements, Douglas H.; Sarama, Julie

2016-01-01

Do young children naturally develop the foundations of science, technology, engineering, and math (STEM)? And if so, should we build on these foundations by using STEM curricula in preschools? In this article, Douglas Clements and Julie Sarama argue that the answer to both these questions is yes. First, the authors show that young children possess…

Other physical factors

Treesearch

John R. Jones; Norbert V. DeByle

1985-01-01

Aspen has been recognized for many years as being very intolerant of shade (Baker 1918a, Clements 1910, Weigle and Frothingham 1911, Zon and Graves 1911). In dense stands, vigorous aspen trees are confined to the dominant and codominant crown classes. Regardless of size, when they are overtopped by larger trees, aspen trees deteriorate and eventually die. Many well-...

Matters of Accuracy and Conventionality: Prior Accuracy Guides Children's Evaluations of Others' Actions

ERIC Educational Resources Information Center

Scofield, Jason; Gilpin, Ansley Tullos; Pierucci, Jillian; Morgan, Reed

2013-01-01

Studies show that children trust previously reliable sources over previously unreliable ones (e.g., Koenig, Clement, & Harris, 2004). However, it is unclear from these studies whether children rely on accuracy or conventionality to determine the reliability and, ultimately, the trustworthiness of a particular source. In the current study, 3- and…

6. Photographic copy of construction drawing, dated May 23, 1935, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Photographic copy of construction drawing, dated May 23, 1935, Selfridge Field Office of the Construction Division of the Quartermaster General, in possession of Selfridge Base Museum, Mt. Clement, Michigan. PLANS, ELEVATIONS, DETAILS, DRAWING NO. 6638-428. - Selfridge Field, Building No. 116, Birch Avenue at Railroad Street, Mount Clemens, Macomb County, MI

Failure to Replicate the "Work Ethic" Effect in Pigeons

ERIC Educational Resources Information Center

Vasconcelos, Marco; Urcuioli, Peter J.; Lionello-DeNolf, Karen M.

2007-01-01

We report six unsuccessful attempts to replicate the "work ethic" phenomenon reported by Clement, Feltus, Kaiser, and Zentall (2000). In Experiments 1-5, pigeons learned two simultaneous discriminations in which the S+ and S- stimuli were obtained by pecking an initial stimulus once or multiple (20 or 40) times. Subsequent preference tests between…

What Pre-Service Teachers Need to Know to Be Effective at Values-Based Education

ERIC Educational Resources Information Center

Mergler, Amanda G.; Spooner-Lane, Rebecca

2012-01-01

Evidence is mounting that values education is providing positive outcomes for students, teachers and schools (Benninga, Berkowitz, Kuehn, & Smith, 2006; DEST, 2008; Hattie, 2003; Lovat, Clement, Dally, & Toomey, 2010). Despite this, Australian pre-service teacher education does not appear to be changing in ways necessary to support…

Postmodern Principles: In Search of a 21st Century Art Education

ERIC Educational Resources Information Center

Gude, Olivia

2004-01-01

The elements and principles of art are enshrined in most art education textbooks today (Crystal Productions, 2000; Hobbs & Salome, 1995; Ragans, 2000; Wachowiak and Clements, 2000). They are presented as the essence of artmaking. If not literally engraved in stone, the big seven (elements) + seven (principles) are reified in print, achieving…

Technology-Based Literature Plans for Elementary Students (Technology Links to Literacy).

ERIC Educational Resources Information Center

Wepner, Shelley B.

1991-01-01

Presents ideas for incorporating software into each guided reading phase for two realistic fiction books: Lois Lowry's "Anastasia on Her Own" and Barthe DeClements's "The Fourth Grade Wizards." Discusses how each skeletal plan uses three pieces of software to enliven students' oral and written thoughts about the books'…

Rewriting Requirements for Design

DTIC Science & Technology

2002-11-06

Lights 1.2.8. Window Lights 2. Behavior Hiding 2.1. Function Drivers 2.1.1. Malfunction Lights 2.1.2. Office Lights 2.2. Shared Services 2.2.1. Mode...4702, 1981. [6] P.C. Clements, Abstract Interface Specifications for the A-7E Shared Services Module, NRL Memorandum Report 4863, 1982. [7] D.L

The Effectiveness of Individual Wellness Counseling on the Wellness of Law Enforcement Officers

ERIC Educational Resources Information Center

Tanigoshi, Holly; Kontos, Anthony P.; Remley, Theodore P.

2008-01-01

The purpose of this exploratory study was to determine the effectiveness of wellness counseling on increasing wellness among law enforcement officers. The study also examined whether position in the Transtheoretical Model (J. O. Prochaska & C. C. DiClemente, 1982) and self-efficacy influenced the effectiveness of counseling on wellness. These…

Leonid Breznev and Richard Nixon examine plaques presented by Skylab crew

NASA Technical Reports Server (NTRS)

1973-01-01

Leonid I. Breznev, General Secretary of the Communist Party, Union of Soviet Socialist Republics, and President Richard M. Nixon, during ceremonies at the Western White House in San Clemente, California, examine plaques presented by Skylab astronauts Charles Conrad Jr., center; Joseph P. Kerwin, second from right; and Paul J. Weitz, left.

Gramsci, Doke and the Marginalisation of the Ndebele Language in Zimbabwe

ERIC Educational Resources Information Center

Ndhlovu, Finex

2006-01-01

Clement M. Doke's 1929-1930 research on Zimbabwean languages has played a key role in shaping the tribalised and politicised linguistic terrain that characterises modern Zimbabwe. Doke, professor of linguistics at the University of Witwaters-rand, was commissioned in 1929 by the government of Southern Rhodesia (present-day Zimbabwe) to research…

Case Studies in the Campus Ministry.

ERIC Educational Resources Information Center

Welsh, Clement W. (Ed.)

This collection of essays on the campus ministry attempts to stimulate interest in developing an efficacious, contemporary role for religion in campus life. An introduction by Clement W. Welch states the place and relationship of the church in the academic community. A section of descriptive essays follows. John J. Kirvan, C.S.P., describes the…

Refining Change Measure with the Rasch Model

ERIC Educational Resources Information Center

Zaporozhets, Olga; Fox, Christine M.; Beltyukova, Svetlana A.; Laux, John M.; Piazza, Nick J.; Salyers, Kathleen

2015-01-01

This study was to develop a linear measure of change using University of Rhode Island Change Assessment items that represented Prochaska and DiClemente's theory. The resulting Toledo Measure of Change is short, is easy to use, and provides reliable scores for identification of individuals' stage of change and progression within that stage.

Hydrogen Release Compound (HRC®) Barrier Application At The North Of Basin F Site, Rocky Mountain Arsenal; Innovative Technology Evaluation Report

EPA Science Inventory

This Innovative Technology Evaluation Report documents the results of a demonstration of the hydrogen release compound (HRC^®) barrier technology developed by Regenesis Bioremediation Products, Inc., of San Clemente, California. HRC^® is a proprietary, food-q...

78 FR 45405 - Endangered and Threatened Wildlife and Plants; Reclassification of Acmispon dendroideus

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-26

...We, the U.S. Fish and Wildlife Service (Service), are reclassifying Acmispon dendroideus var. traskiae (San Clemente Island lotus) and Castilleja grisea (San Clemente Island paintbrush) from endangered to threatened. The endangered designation no longer correctly reflects the status of these plants due to substantial improvement in their status. This action is based on a review of the best available scientific and commercial data, which indicate that the ongoing threats are not of sufficient imminence, intensity, or magnitude to indicate that A. d. var. traskiae and C. grisea are presently in danger of extinction across their ranges. While both taxa will continue to be impacted by military training activities and land use, erosion, nonnative plants, and fire, the significant increase in abundance (number of occurrences) of both taxa reduces the severity and magnitude of threats and the likelihood that any one event would affect all occurrences of either taxon. Additionally, the Department of the Navy (Navy) is implementing conservation actions through their Integrated Natural Resources Management Plan and has successfully reduced threats impacting both taxa and their habitat.

Three-Dimensional Effects on Multi-Element High Lift Computations

NASA Technical Reports Server (NTRS)

Rumsey, Christopher L.; Lee-Rausch, Elizabeth M.; Watson, Ralph D.

2002-01-01

In an effort to discover the causes for disagreement between previous 2-D computations and nominally 2-D experiment for flow over the 3-clement McDonnell Douglas 30P-30N airfoil configuration at high lift, a combined experimental/CFD investigation is described. The experiment explores several different side-wall boundary layer control venting patterns, document's venting mass flow rates, and looks at corner surface flow patterns. The experimental angle of attack at maximum lift is found to be sensitive to the side wall venting pattern: a particular pattern increases the angle of attack at maximum lift by at least 2 deg. A significant amount of spanwise pressure variation is present at angles of attack near maximum lift. A CFD study using 3-D structured-grid computations, which includes the modeling of side-wall venting, is employed to investigate 3-D effects of the flow. Side-wall suction strength is found to affect the angle at which maximum lift is predicted. Maximum lift in the CFD is shown to be limited by the growth of all off-body corner flow vortex and consequent increase in spanwise pressure variation and decrease in circulation. The 3-D computations with and without wall venting predict similar trends to experiment at low angles of attack, but either stall too earl or else overpredict lift levels near maximum lift by as much as 5%. Unstructured-grid computations demonstrate that mounting brackets lower die the levels near maximum lift conditions.

Preference for a Stimulus that Follows a Relatively Aversive Event: Contrast or Delay Reduction?

ERIC Educational Resources Information Center

Singer, Rebecca A.; Berry, Laura M.; Zentall, Thomas R.

2007-01-01

Several types of contrast effects have been identified including incentive contrast, anticipatory contrast, and behavioral contrast. Clement, Feltus, Kaiser, and Zentall (2000) proposed a type of contrast that appears to be different from these others and called it within-trial contrast. In this form of contrast the relative value of a reinforcer…

76 FR 54453 - Availability of the Proposed Report of the Chief of Engineers and the Final Joint Environmental...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-01

... effects associated with the proposed action and alternatives for providing shoreline protection to approximately 3,412 feet ([ft], 1,040 meters [m]) of the San Clemente shoreline from coastal storms. Maintaining.... The Los Angeles to San Diego (LOSSAN) railroad line, separating the active coastline from the coastal...

Multi-Decadal Variability in the Bering Sea: A Synthesis of Model Results and Observations from 1948 to the Present

DTIC Science & Technology

2013-12-01

stated that the development and use of high-resolution Arctic climate and systems models are important stepping stones for dedicated studies of...W., J. L. Clement Kinney, D. C. Marble , and J. Jakacki, 2008: Towards eddy resolving models of the Arctic Ocean: Ocean Modeling in an Eddying

Standardisation a Considerable Force behind Language Death: A Case of Shona

ERIC Educational Resources Information Center

Mhute, Isaac

2016-01-01

The paper assesses the contribution of standardisation towards language death taking Clement Doke's resolutions on the various Shona dialects as a case study. It is a qualitative analysis of views gathered from speakers of the language situated in various provinces of Zimbabwe, the country in which the language is spoken by around 75% of the…

25 Years Later: A History of the McClellan-Kerr Arkansas River Navigation System in Arkansas

DTIC Science & Technology

1995-01-01

and Clements, ’’Arkansas River ... Sediment Control," chap. 18, pp. 15-16; Ronald A. Antonino , "The Arkansas River Project," Civil Engineering (Dec...March 8, 1989. Secondary Sources Antonino , Ronald A. "The Arkansas River Project," Civil Engineering (Dec. 1969): 44- 49. Arnold, Morris S

The process of natural succession in urban areas

Treesearch

Wayne C. Zipperer

2011-01-01

Succession has been a fundamental concept in ecology. Its classical definition is the orderly change in vegetation at a site that is predictable and directional towards a climax state or end point (Clements 1916). A general assumption of succession is that early seres are governed by allogenic processes, environmental processes external to the site, and early seres...

Variable Pitch Propellers

NASA Technical Reports Server (NTRS)

1920-01-01

In this report are described four different types of propellers which appeared at widely separated dates, but which were exhibited together at the last Salon de l'Aeronautique. The four propellers are the Chaviere variable pitch propeller, the variable pitch propeller used on the Clement Bayard dirigible, the variable pitch propeller used on Italian dirigibles, and the Levasseur variable pitch propeller.

SKYLAB (SL)-2 POSTFLIGHT - COMMEMORATIVE PLAQUES PRESENTATION - CA

NASA Image and Video Library

1973-07-19

S73-30889 (June 1973) --- Leonid I. Breznev, General Secretary of the Communist Party, Union of Soviet Socialist Republics, and President Richard M. Nixon, during ceremonies at the Western White House in San Clemente, California, examine plaques presented by Skylab astronauts Charles Conrad Jr., center; Joseph P. Kerwin, second from right; and Paul J. Weitz, left. Photo credit: NASA

Submesoscale Structure of the California Current Near San Clemente Island

DTIC Science & Technology

1990-06-01

components at the 8 km line in figure 9 p• p - e 0 Fi u eOFS JSlIE DIS TAIIC I |MI .: ..- 1111 O, AIF | KA Figrellh. Vertical cross-section of standard...7. Huyer, Adriana and P. Michael Kosro, Mesoscale Surveys over the Shelf and Slope in the Upwelling Region Near Point Arena, California, J. Geophs

Fadeout in an Early Mathematics Intervention: Same Old Schools or Underlying Skills?

ERIC Educational Resources Information Center

Bailey, Drew H.; Nguyen, Tutrang; Jenkins, Jade Marcus; Domina, Thurston; Clements, Douglas H.; Sarama, Julie; Wolfe, Christopher B.; Spitler, Mary Elaine

2015-01-01

A consistent finding across early childhood interventions targeting mathematics and other achievement-related skills that is that initial treatment effects fade over time, with children not receiving the intervention catching up to children who did (Clements et al., 2013; Leak et al., 2010; Puma et al., 2010). One popular explanation for this is…

Mexican Muralism: Its Social-Educative Roles in Latin America and the United States.

ERIC Educational Resources Information Center

Goldman, Shifra M.

1982-01-01

Traces the history of Mexican muralism (1920s to 1970s) as an art of advocacy intended to change consciousness and promote political action; shows how it can still be used in an educative manner in schools. Emphasizes the effects of three great muralists (Diego Rivera, Jose Clemente Orozco, and David Alfaro Siqueiros). (LC)

ACHP | News | President Appoints Clement A. Price Vice Chairman of ACHP

Science.gov Websites

Project Honored For Federal Leadership, Commitment to Historic Hanford Facility Department of Energy’s B Reactor Preservation Project Honored For Federal Leadership, Commitment to Historic Hanford Facility Reactor Preservation Project at DOE’s Hanford Site in southeastern Washington state. “The B Reactor

Relationships between firing pattern, fuel consumption, and turbulence and energy exchange during prescribed fires

Treesearch

Kenneth L. ​Clark; Michael Gallagher; Warren E. Heilman; Nicholas Skowronski; Eric Mueller; Albert. Simeoni

2017-01-01

Fuel loading and consumption during prescribed fires are well-characterized for many pine-dominated forests, but relationships between firing practices, consumption of specific fuel components, and above-canopy turbulence and energy exchange have received less attention (Ottmar et al. 2016, Clements et al. 2016). However, quantitative information on how firing patterns...

The Mineralogy of Martian Dust: Design and Analysis Considerations for an X-Ray Diffraction/X-Ray Fluorescence (XRD/XRF) Instrument for Exobiological Studies

NASA Technical Reports Server (NTRS)

Blake, David; Vaniman, David; Bish, David; Morrison, David (Technical Monitor)

1994-01-01

A principal objective of Mars exploration is the search for evidence of past life which may have existed during an earlier clement period of Mars history. We would like to investigate the history of surface water activity (which is a requirement for all known forms of life) by identifying and documenting the distribution of minerals which require water for their formation or distribution. A knowledge of the mineralogy of the present Martian surface would help to identify areas which, due to the early activity of water, might have harbored ancient life. It would be desirable to establish the presence and characterize the distribution of hydrated minerals such as clays, and of minerals which are primarily of sedimentary origin such as carbonates, silica and evaporites. Mineralogy, which is more critical to exobiological exploration than is simple chemical analysis (absent the detection of organics), will remain unknown or will at best be imprecisely constrained unless a technique sensitive to mineral structure such as powder X-ray diffraction (XRD) is employed. Additional information is contained in the original extended abstract.

Airborne dust transport to the eastern Pacific Ocean off southern California: Evidence from San Clemente Island

USGS Publications Warehouse

Muhs, D.R.; Budahn, J.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.

2007-01-01

Islands are natural dust traps, and San Clemente Island, California, is a good example. Soils on marine terraces cut into Miocene andesite on this island are clay-rich Vertisols or Alfisols with vertic properties. These soils are overlain by silt-rich mantles, 5-20 cm thick, that contrast sharply with the underlying clay-rich subsoils. The silt mantles have a mineralogy that is distinct from the island bedrock. Silt mantles are rich in quartz, which is rare in the island andesite. The clay fraction of the silt mantles is dominated by mica, also absent from local andesite, and contrasts with the subsoils, dominated by smectite. Ternary plots of immobile trace elements (Sc-Th-La and Ta-Nd-Cr) show that the island andesite has a composition intermediate between average upper continental crust and average oceanic crust. In contrast, the silt and, to a lesser extent, clay fractions of the silt mantles have compositions closer to average upper continental crust. The silt mantles have particle size distributions similar to loess and Mojave Desert dust, but are coarser than long-range-transported Asian dust. We infer from these observations that the silt mantles are derived from airborne dust from the North American mainland, probably river valleys in the coastal mountains of southern California and/or the Mojave Desert. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. Examination of satellite imagery shows that easterly Santa Ana winds carry abundant dust to the eastern Pacific Ocean and the California Channel Islands. Airborne dust from mainland North America may be an important component of the offshore sediment budget in the easternmost Pacific Ocean, a finding of potential biogeochemical and climatic significance.

Moving from Batch to Field Using the RT3D Reactive Transport Modeling System

NASA Astrophysics Data System (ADS)

Clement, T. P.; Gautam, T. R.

2002-12-01

The public domain reactive transport code RT3D (Clement, 1997) is a general-purpose numerical code for solving coupled, multi-species reactive transport in saturated groundwater systems. The code uses MODFLOW to simulate flow and several modules of MT3DMS to simulate the advection and dispersion processes. RT3D employs the operator-split strategy which allows the code solve the coupled reactive transport problem in a modular fashion. The coupling between reaction and transport is defined through a separate module where the reaction equations are specified. The code supports a versatile user-defined reaction option that allows users to define their own reaction system through a Fortran-90 subroutine, known as the RT3D-reaction package. Further a utility code, known as BATCHRXN, allows the users to independently test and debug their reaction package. To analyze a new reaction system at a batch scale, users should first run BATCHRXN to test the ability of their reaction package to model the batch data. After testing, the reaction package can simply be ported to the RT3D environment to study the model response under 1-, 2-, or 3-dimensional transport conditions. This paper presents example problems that demonstrate the methods for moving from batch to field-scale simulations using BATCHRXN and RT3D codes. The first example describes a simple first-order reaction system for simulating the sequential degradation of Tetrachloroethene (PCE) and its daughter products. The second example uses a relatively complex reaction system for describing the multiple degradation pathways of Tetrachloroethane (PCA) and its daughter products. References 1) Clement, T.P, RT3D - A modular computer code for simulating reactive multi-species transport in 3-Dimensional groundwater aquifers, Battelle Pacific Northwest National Laboratory Research Report, PNNL-SA-28967, September, 1997. Available at: http://bioprocess.pnl.gov/rt3d.htm.

Second-order contrast based on the expectation of effort and reinforcement.

PubMed

Clement, Tricia S; Zentall, Thomas R

2002-01-01

Pigeons prefer signals for reinforcement that require greater effort (or time) to obtain over those that require less effort to obtain (T. S. Clement, J. Feltus, D. H. Kaiser, & T. R. Zentall, 2000). Preference was attributed to contrast (or to the relatively greater improvement in conditions) produced by the appearance of the signal when it was preceded by greater effort. In Experiment 1, the authors of the present study demonstrated that the expectation of greater effort was sufficient to produce such a preference (a second-order contrast effect). In Experiments 2 and 3, low versus high probability of reinforcement was substituted for high versus low effort, respectively, with similar results. In Experiment 3, the authors found that the stimulus preference could be attributed to positive contrast (when the discriminative stimuli represented an improvement in the probability of reinforcement) and perhaps also negative contrast (when the discriminative stimuli represented reduction in the probability of reinforcement).

Statistical Modeling of Radiometric Error Propagation in Support of Hyperspectral Imaging Inversion and Optimized Ground Sensor Network Design

DTIC Science & Technology

2008-09-04

mospheric correction. volume 3756, pages 348–353. SPIE, 1999. Daniel Birkenheuer and Seth Gutman. A Comparison of GOES Moisture-Derived Product and GPS...pages 417–428. SPIE, 2001. E. J. Ientilucci and S. D. Brown. Advances in wide-area hyperspectral image sim- ulation. In W. R. Watkins , D. Clement

Learning and Teaching Early Math: The Learning Trajectories Approach, 2nd Edition. Studies in Mathematical Thinking and Learning Series

ERIC Educational Resources Information Center

Clements, Douglas H.; Sarama, Julie

2014-01-01

In this important book for pre- and in-service teachers, early math experts Douglas Clements and Julie Sarama show how "learning trajectories" help diagnose a child's level of mathematical understanding and provide guidance for teaching. By focusing on the inherent delight and curiosity behind young children's mathematical reasoning,…

Within-Trial Contrast: When Is a Failure to Replicate Not a Type I Error?

ERIC Educational Resources Information Center

Zentall, Thomas R.; Singer, Rebecca A.

2007-01-01

Vasconcelos, Urcuioli, and Lionello-DeNolf (2007) report the results of five experiments that fail to replicate the results of our within-trial contrast study (Clement, Feltus, Kaiser, & Zentall, 2000) and suggest that our results may represent a Type I Error. We believe that this conclusion is not warranted because (a) there is considerable…

When Is a Failure to Replicate Not a Type II Error?

ERIC Educational Resources Information Center

Vasconcelos, Marco; Urcuioli, Peter J.; Lionello-DeNolf, Karen M.

2007-01-01

Zentall and Singer (2007) challenge our conclusion that the work-ethic effect reported by Clement, Feltus, Kaiser, and Zentall (2000) may have been a Type I error by arguing that (a) the effect has been extensively replicated and (b) the amount of overtraining our pigeons received may not have been sufficient to produce it. We believe that our…

Teambuilding: A Strategic Leader Imperative

DTIC Science & Technology

2006-03-10

at least initially) examples from the private sector. Yet looking to leaders like Jack Welch, former CEO for General Electric, and Warren Buffett , a...at Division Command Level – 2004. Ulmer, Shaler, Bullis, DiClemente, and Jacobs – 5 Nov 2004, 10. 44 “ Warren Buffet Biography,” available from http:// beginnersinvest.about.com/cs / warrenbuffett/a/aawarrenbio.htm; accessed 8 March 2006.

77 FR 58132 - Public Water System Supervision Program Revision for the State of Utah

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-19

... accordance with the provisions of Section 1413 of the Safe Drinking Water Act (SDWA), 42 U.S.C. 300g-2... 2 Disinfectants and Disinfection Byproducts Rule that correspond to the National Primary Drinking... Administrator, c/o Robert Clement, Drinking Water Unit (8P-W-DW), U.S. EPA, Region 8, 1595 Wynkoop Street...

Latin America Report.

DTIC Science & Technology

1985-08-09

They acknowledged the importance of tourism to promote the economic integra- tion and development of the two countries and stated their intention to...adopt measures aimed at increasing tourism through coordinated and joint efforts by national authorities. This work will be done by a commission to...6 [Article by Anthony Forbes] [Excerpts] FOREIGN and Tourism Minister Clement Maynard said today that the governments of the Bahamas and other

Applying the Transtheoretical Model of Change to the Sequencing of Ethics Instruction in Business Education

ERIC Educational Resources Information Center

Tyler, Catherine L.; Tyler, J. Michael

2006-01-01

Although there is widespread agreement on the importance of ethics instruction in business education, there is not agreement on the best approach or timing of instruction. This article uses J. O. Prochaska and DiClemente's transtheoretical model of change as the basis for a developmental model of student readiness for learning about ethics. By…

Relations of Transtheoretical Model Stage, Self-Efficacy, and Voluntary Physical Activity in African American Preadolescents

ERIC Educational Resources Information Center

Annesi, James J.; Faigenbaum, Avery D.; Westcott, Wayne L.

2010-01-01

The transtheoretical model (TTM; Prochaska, DiClemente, & Norcross, 1992) suggests that, at any point, an individual is in one of five stages-of-change related to adopting a behavior. People sequentially advance in stage but may also maintain or even regress, based on personal and environmental factors (Nigg, 2005). A classic study published in…

Preparing Prekindergartners with Math Readiness Skills: The Effect of Children's Talk, Focus, and Engagement on Math Achievement

ERIC Educational Resources Information Center

Cummings, Tracy; Hofer, Kerry G.; Farran, Dale C.; Lipsey, Mark W.; Bilbrey, Carol; Vorhaus, Elizabeth

2009-01-01

The "Building Blocks PreK Math Curriculum" (Clements & Sarama, 2007) was designed to facilitate children's engagement in math and talk about math. Much research investigates the effect of curriculum on classrooms or teacher practices. This study used a mediational model to look at a curriculum's effect on children's achievement gain, operating…

Nest-site characteristics and linear abundance of cliff-nesting American kestrels on San Clemente Island, California

USGS Publications Warehouse

Sullivan, Brian L.; Kershner, Eric L.; Finn, S.P.; Condon, Anne M.; Cooper, Douglass M.; Garcelon, David K.

2003-01-01

American Kestrels( Falco sparverius) are typically secondary-cavity nesters, and use of natural cliff cavities for nest sites is less-commonly reported. On San Clemente Island (SCI), California, however, American Kestrels nest primarily on cliffs in major canyons(93%), to a lesser extent on seacliffs(4%), as well as in man-made structures (3%). We located and mapped 99 American Kestrel territories on SCI, and recorded 11 nest-site characteristics at 40 cliff nests during 2001-02. Nest cliffs were typically fractured igneous rock with mean height of 16.1 m +_ 1.8 SE. Mean slope of nest cliffs was vertical (x=91 degrees). Nest cliffs and cavities were significantly oriented to the southeast, away from the prevailing wind direction(NW). In eight canyons, where we believe that we found all occupied American Kestrel territories, the mean linear abundance was 2.1 pairs/km, greater than most published estimates. Contrary to most previous studies, no American Kestrels nested in tree cavities despite their presence in SCI canyons. The absence of cavity-excavating breeding birds from the island likely restricts kestrels to nesting in naturally-formed cavities and man-made structures.

Offshore killer whale tracking using multiple hydrophone arrays.

PubMed

Gassmann, Martin; Henderson, E Elizabeth; Wiggins, Sean M; Roch, Marie A; Hildebrand, John A

2013-11-01

To study delphinid near surface movements and behavior, two L-shaped hydrophone arrays and one vertical hydrophone line array were deployed at shallow depths (<125 m) from the floating instrument platform R/P FLIP, moored northwest of San Clemente Island in the Southern California Bight. A three-dimensional propagation-model based passive acoustic tracking method was developed and used to track a group of five offshore killer whales (Orcinus orca) using their emitted clicks. In addition, killer whale pulsed calls and high-frequency modulated (HFM) signals were localized using other standard techniques. Based on these tracks sound source levels for the killer whales were estimated. The peak to peak source levels for echolocation clicks vary between 170-205 dB re 1 μPa @ 1 m, for HFM calls between 185-193 dB re 1 μPa @ 1 m, and for pulsed calls between 146-158 dB re 1 μPa @ 1 m.

Island Fox Veterinary And Pathology Services On San Clemente Island, California

DTIC Science & Technology

2017-02-01

conservation and management efforts by attempting to mitigate anthropogenic-related injuries or illnesses. We utilized our mobile veterinary hospital...the U.S. Navy. The Island Fox Veterinary and Pathology Services project was designed to assist the Navy in island fox conservation and management ...the California Animal Health and Food Safety Laboratory System (CAHFS), at the University of California, Davis, to be necropsied. Necropsy reports

Proceedings of the Ground Target Modeling and Validation Conference (13th) Held in Houghton, MI on 5-8 August 2002

DTIC Science & Technology

2002-08-01

excessively high aspect ratio, the forward region of the original model was removed. The final grid (rear half) had 383104 computational cells compared...45 Session III: Thermal Signature Modeling and Validation Session...Chair: Dr. Dieter Clement, FGAN-FOM " Modeling the Thermal Signature of Natural Backgrounds" Marius Gamborg, Norwegian Defence Research Establishm

The Path to a Quality Education for All Texas Students. Final Report of the Governor's Task Force on Public Education.

ERIC Educational Resources Information Center

Texas Governor's Office, Austin.

On November 9, 1989, Governor William P. Clements, Jr., established a Task Force on Public Education and charged it to develop a blueprint for restructuring public education in Texas. The state public education system is under taxpayer pressure to improve performance and under court order to correct funding inequities. This report describes the…

Increasing Access to Post-Secondary Education: A Mixed Methods Study of the Charleston Clemente Program

ERIC Educational Resources Information Center

Doyle, Mariane Asad

2014-01-01

There is an economic gap that favors adults who have higher levels of educational attainment (United States Department of Labor, 2010). With more than 9.3 million Americans over the age of 25 facing unemployment as of June 2012 and over 79% or 7.4 million of those unemployed Americans having attained less than a Bachelor's degree (U.S. Department…

World Epidemiology Review, Number 103.

DTIC Science & Technology

1978-08-30

meeting. One of the papers dealt with a special research done on gastro- intestinal parasites on Speaking about other issues discussed...Reported (EL DIA, 28 Jul 78) 32 DENMARK Government To Tighten Control Over Use of Animal Medicines (POLITIKEN, 21 Jul 78) 34 ETHIOPIA ... ETHIOPIA Briefs Locust Invasion 44 GHANA FRG To Finance Tsetse Fly Control Program (Clement Asante; GHANAIAN TIMES, 2 Aug 78) 45 HUNGARY Briefs

ACHP | News | President Appoints Clement A. Price Vice Chairman of ACHP

Science.gov Websites

; Price is the Board of Governors Distinguished Service Professor of History and the founder and Director B.A. and M.A. in History from the University of Bridgeport and his Ph.D. in History from Rutgers contributions to the knowledge and appreciation of Newark history. Price will receive the oath of office and

Los Angeles-Long Beach area of Southern California as seen from Apollo 9

NASA Image and Video Library

1969-03-09

AS09-22-3436 (March 1969) --- Los Angeles-Long Beach area of southern California, as photographed from the Apollo 9 spacecraft during its 92nd revolution of Earth. Santa Catalina Island is located off the coast. The California coastline is visible from San Clemente northward to Point Dume. Clouds cover most of the San Gabriel Mountains around Los Angeles.

Leadership Lessons at Division Command Level - 2004

DTIC Science & Technology

2004-11-05

9 Four domains of “emotional intelligence” are described by Goleman , Daniel et. al. in Primal Leadership: Realizing the Power of...Campbell, Ph.D. Senior Fellow, Center for Creative Leadership Diane F. DiClemente, Ph.D. Visiting Professor of Psychology , USAWC T. Owen Jacobs, Ph.D. Leo...35 The Armed Forces Officer , USGPO, 1960. Page 50. 36 See for example, “ Psychological Orientations and Leadership: Thinking Style That

Mexican Muralists: Rivera, Siqueiros, and Orozco. Curriculum Projects. Fulbright-Hays Summer Seminars Abroad Program, 2002 (Mexico).

ERIC Educational Resources Information Center

Walter, Kim

Murals created by Diego Rivera, Jose Clemente Orozco, and David Alfaro Siqueiros embody a time of change in Mexico. The murals they created were intended to educate an illiterate population. Today these murals embody national pride. The goal of this curriculum project is rooted in learning about the history, culture, and art of Mexico. The project…

Custodians of Quality: Mathematics Education in Australasia--Where from? Where at? Where to?

ERIC Educational Resources Information Center

Galbraith, Peter

2014-01-01

As a contribution to honour the foresight of Ken Clements and John Foyster in founding MERGA [Mathematics Education Research Group of Australasia] so many years ago this paper is not a research paper in the usual sense. Rather it sets out to sample the context of Mathematics Education in Australasia and beyond (then and now) and to highlight some…

Transsexualism and Flight Safety

DTIC Science & Technology

1987-05-08

Security Classification) Transsexualism and Flight Safety 12. PERSONAL AUTHOR(S) Clements, Thomas I. and Wicks, Roland E. 13a. TYPE OF REPORT 13b. TIME... transsexual pilot with questionable judgment affecting flight safety is reported. The definition, etiology, and presenting symptoms are discussed. Three...involve all the phases of therapy and can be significant. Though the transsexual tends to have more episodes of anxiety and depression than the norm

The Effect of Host Star Spectral Energy Distribution and Ice-Albedo Feedback on the Climate of Extrasolar Planets

PubMed Central

Meadows, Victoria S.; Bitz, Cecilia M.; Pierrehumbert, Raymond T.; Joshi, Manoj M.; Robinson, Tyler D.

2013-01-01

Abstract Planetary climate can be affected by the interaction of the host star spectral energy distribution with the wavelength-dependent reflectivity of ice and snow. In this study, we explored this effect with a one-dimensional (1-D), line-by-line, radiative transfer model to calculate broadband planetary albedos as input to a seasonally varying, 1-D energy balance climate model. A three-dimensional (3-D) general circulation model was also used to explore the atmosphere's response to changes in incoming stellar radiation, or instellation, and surface albedo. Using this hierarchy of models, we simulated planets covered by ocean, land, and water-ice of varying grain size, with incident radiation from stars of different spectral types. Terrestrial planets orbiting stars with higher near-UV radiation exhibited a stronger ice-albedo feedback. We found that ice extent was much greater on a planet orbiting an F-dwarf star than on a planet orbiting a G-dwarf star at an equivalent flux distance, and that ice-covered conditions occurred on an F-dwarf planet with only a 2% reduction in instellation relative to the present instellation on Earth, assuming fixed CO2 (present atmospheric level on Earth). A similar planet orbiting the Sun at an equivalent flux distance required an 8% reduction in instellation, while a planet orbiting an M-dwarf star required an additional 19% reduction in instellation to become ice-covered, equivalent to 73% of the modern solar constant. The reduction in instellation must be larger for planets orbiting cooler stars due in large part to the stronger absorption of longer-wavelength radiation by icy surfaces on these planets in addition to stronger absorption by water vapor and CO2 in their atmospheres, which provides increased downwelling longwave radiation. Lowering the IR and visible-band surface ice and snow albedos for an M-dwarf planet increased the planet's climate stability against changes in instellation and slowed the descent into global ice coverage. The surface ice-albedo feedback effect becomes less important at the outer edge of the habitable zone, where atmospheric CO2 could be expected to be high such that it maintains clement conditions for surface liquid water. We showed that ∼3–10 bar of CO2 will entirely mask the climatic effect of ice and snow, leaving the outer limits of the habitable zone unaffected by the spectral dependence of water ice and snow albedo. However, less CO2 is needed to maintain open water for a planet orbiting an M-dwarf star than would be the case for hotter main-sequence stars. Key Words: Extrasolar planets—M stars—Habitable zone—Snowball Earth. Astrobiology 13, 715–739. PMID:23855332

The effect of host star spectral energy distribution and ice-albedo feedback on the climate of extrasolar planets.

PubMed

Shields, Aomawa L; Meadows, Victoria S; Bitz, Cecilia M; Pierrehumbert, Raymond T; Joshi, Manoj M; Robinson, Tyler D

2013-08-01

Planetary climate can be affected by the interaction of the host star spectral energy distribution with the wavelength-dependent reflectivity of ice and snow. In this study, we explored this effect with a one-dimensional (1-D), line-by-line, radiative transfer model to calculate broadband planetary albedos as input to a seasonally varying, 1-D energy balance climate model. A three-dimensional (3-D) general circulation model was also used to explore the atmosphere's response to changes in incoming stellar radiation, or instellation, and surface albedo. Using this hierarchy of models, we simulated planets covered by ocean, land, and water-ice of varying grain size, with incident radiation from stars of different spectral types. Terrestrial planets orbiting stars with higher near-UV radiation exhibited a stronger ice-albedo feedback. We found that ice extent was much greater on a planet orbiting an F-dwarf star than on a planet orbiting a G-dwarf star at an equivalent flux distance, and that ice-covered conditions occurred on an F-dwarf planet with only a 2% reduction in instellation relative to the present instellation on Earth, assuming fixed CO(2) (present atmospheric level on Earth). A similar planet orbiting the Sun at an equivalent flux distance required an 8% reduction in instellation, while a planet orbiting an M-dwarf star required an additional 19% reduction in instellation to become ice-covered, equivalent to 73% of the modern solar constant. The reduction in instellation must be larger for planets orbiting cooler stars due in large part to the stronger absorption of longer-wavelength radiation by icy surfaces on these planets in addition to stronger absorption by water vapor and CO(2) in their atmospheres, which provides increased downwelling longwave radiation. Lowering the IR and visible-band surface ice and snow albedos for an M-dwarf planet increased the planet's climate stability against changes in instellation and slowed the descent into global ice coverage. The surface ice-albedo feedback effect becomes less important at the outer edge of the habitable zone, where atmospheric CO(2) could be expected to be high such that it maintains clement conditions for surface liquid water. We showed that ∼3-10 bar of CO(2) will entirely mask the climatic effect of ice and snow, leaving the outer limits of the habitable zone unaffected by the spectral dependence of water ice and snow albedo. However, less CO(2) is needed to maintain open water for a planet orbiting an M-dwarf star than would be the case for hotter main-sequence stars.

Two-way feedback between biology and deep Earth processes

NASA Astrophysics Data System (ADS)

Sleep, N. H.; Pope, E.; Bird, D.

2012-12-01

The presence of the metamorphic products of banded iron formation and black shale indicate that the Earth teemed with life by the time of the earliest preserved rocks, ca. 3.85 Ga. Iron and sulfur-based anoxygenic photosynthesis with full carbon cycles was present by this time. The pH of the ocean was ~8. The lack of older rock record cloaks pre-biotic evolution and the origin of life. Nascent and early life obtained energy from chemical disequilibria in rocks rather than sunlight. Appraising putative rock pre-biological environments is difficult in that life has modified the composition of the atmosphere, the hydrosphere, and sedimentary rocks. It has greatly affected the composition of crystalline crustal rocks and measurably modified the mantle. Conversely, hard crustal rocks and the mantle likely sequester a very ancient record of last resort. Theory provides additional insight. The Earth's surface and interior cooled following the moon-forming impact. The oceans passed through conditions favored by thermophile organisms before becoming clement. Ocean pH was ~6 and bars of CO2 existed in the atmosphere. Subduction removed the CO2 into the mantle before the time of rock record. Serpentinite likely existed in land, tidal, and marine environments as it does today. Seafloor spreading and arc volcanism likely drove hydrothermal circulation. The late heavy bombardment occurred after ca. 4.1 Ga; low heat flow environments and hence habitable subsurface refugia existed. It is conceivable that one or a few ocean-boiling impacts left thermophile survivors in their wake. Overall, the molecular biology of extant life likely conserves features that relate to its earliest abodes.

General Merrill A. McPeak: An Effective Change Agent?

DTIC Science & Technology

1997-04-01

McPeak, 115-121. 18 Interview with General McPeak, 21 March 1997. 24 Chapter 7 Managing Change Wallace and Szilagyi in Managing Behavior in...Andrew D. Szilagyi , Jr., Managing Behavior in Organizations, (Glenview, Illinois, Scott, Foesman and Company, 1982), 387. 2 Jaques and Clement, 274. 3...Airman. Nov ‘93. Wallace, Marc J. and Szilagyi , Andrew D. Managing Behavior in Organizations. Glenview, IL., Scott, Foesman and Company, 1982

San Clemente Island Baseline LiDAR Mapping Final Report

DTIC Science & Technology

2016-12-01

automatically detect individual shrubs , though this method was more successful in some places than others. Finally, the hyperspectral data cubes, with...for California coastal shrub land, likely because the LiDAR tends not to penetrate the dense shrub , resulting in nearly identical first and last...subclasses of these structures. Using the aerial photographs in conjunction with the ground truth data, we automated the identification of the shrub Rhus

Civil Wars in Britain, 1640-1646 Military Revolution on Campaign

DTIC Science & Technology

2001-01-01

revolution thesis. In the 1980s David Parrott argued that the tactical reforms described by Roberts were in practice nearly irrelevant to the battles...Social Order: Reading and Writing in Tudor and Stuart England (Cambridge: Cambridge University Press, 1980 ), passim. 8A royal license was obtained by...Finlayson, Clement Little and His Library: The Origins of Edinburgh University Library (Edinburgh: Edinburgh University, 1980 ). 10Jean R. Guild and

VISITOR - PRES. NIXON - PROTOCOL - JSC

NASA Image and Video Library

1974-03-20

Five (5) views of President Richard M. Nixon during his visit to the JSC. These views show the President as he addresses a crowd of employees and visitors outside of Building 1 Auditorium. Dr. Christopher C. Kraft, Fletcher, and Astronaut Gerald Carr, with Pete Clements, George Abbey, and Jack Waite in the background is also seen with the President. 1. Pres. Richard M. Nixon 2. Dr. Christopher C. Kraft JSC, HOUSTON, TX

Analysis of Satellite Communication as a Method to Meet Information Exchange Requirements for the Enhanced Company Concept

DTIC Science & Technology

2008-09-01

For the technical support and on the job training: Donovan Dinger, Swe-Dish Michael Clement, NPS CENETIX Lab Maj Cornell, MCTSSA Eric Gay , MCTSSA...OPERATION ENDURING FREEDOM (OEF). Of note, the Battalion’s current operations officer, Capt Jeremiah Salame, a company commander during the 2006...was for higher headquarters or even high level decision makers 10 Capt Salame (1/7 Battalion

Assessing Layered Materials in Gale Crater

NASA Technical Reports Server (NTRS)

Bridges, N. T.

2001-01-01

The recent analysis of high resolution Mars Orbiter Camera (MOC) images of layered outcrops in equatorial regions reinforces two important ideas, which will probably eventually become paradigms, about Mars: 1) It has had a long, complex geologic history marked by change, as manifested in the different layers observed, and 2) Standing bodies of water existed for substantial lengths of time, indicating clement conditions possibly conducive to life. Although observations of layering and evidence for lakes and oceans has been reported for years based on Mariner 9 and Viking data, the MOC data show that this layering is much more pervasive and complex than previously thought. These layered sites are ideal for studying the geologic, and possibly biologic, history of Mars. Here, a layered site within Gale Crater is advocated as a Mars Exploration Rover (MER) target. This is one of the few layered areas within closed depressions (e.g., other craters and Vallis Marineris) that meets the landing site constraints and is accessible to both MER A and B.

Caught in a Web of Abjection: High-Stakes Testing in Miriam Cohen's "First Grade Takes a Test" and Andrew Clements' "The Report Card"

ERIC Educational Resources Information Center

Anderson, Anne W.

2018-01-01

Standardized achievement testing of children began in the United States in the 1960s. Since then, the data produced from such tests has been extrapolated to measure schools, teachers, and principals. Today, testing and its corollaries consume much of the time and energy of teachers and students. Miriam Cohen's (2006/1980) "First Grade Takes a…

Probability-Based Inference in Cognitive Diagnosis

DTIC Science & Technology

1994-02-01

of variables in the student model. In Siegler’s study , this corresponds to determining how a child with a given set of strategies at her disposal...programs are commercially available to carry out the number-crunching aspect. We used Andersen, Jensen, Olesen, and Jensen’s (1989) HUGIN program and Noetic ... studying how they are typically acquired (e.g., in mechanics, Clement, 1982; in ratio and proportional reasoning, Karplus, Pulos, & Stage, 1983), and

Conformally flat black hole initial data with one cylindrical end

NASA Astrophysics Data System (ADS)

Gabach Clément, María E.

2010-06-01

We give a complete analytical proof of the existence and uniqueness of extreme-like black hole initial data for Einstein equations, which possess a cylindrical end, analogous to extreme Kerr, extreme Reissner-Nördstrom and extreme Bowen-York's initial data. This extends and refines a previous result (Dain and Clement 2009 Class. Quantum Grav. 26 035020) to a general case of conformally flat, maximal initial data with angular momentum, linear momentum and matter.

Coherent anti-phasing between solar forcing and tropical Pacific climate over the past millennium: derivation and implications

NASA Astrophysics Data System (ADS)

Emile-Geay, J.; Cobb, K.; Mann, M. E.; Wittenberg, A. T.

2011-12-01

Using a compilation of the most recent, high-resolution proxy data from the tropics, and a state-of-the-art climate reconstruction technique (RegEM iTTLS; Emile-Geay et al, submitted), we reconstruct sea-surface temperature (SST) in the central equatorial Pacific (NINO3.4 region) over the past millennium. Using frozen network experiments and pseudoproxy validation, the reconstruction is found skillful back to 1150 C.E., with inevitable amplitude reduction before 1500 C.E. due to the paucity of proxy predictors. Despite this caveat, wavelet coherency analysis reveals a marked anticorrelation between solar forcing (as estimated from cosmogenic isotope concentrations; Bard et al., 2007; Steinhilber et al., 2009) and the reconstructed NINO3.4 in the ~sim205-year spectral range (DeVries cycle). The phase angle between both signals is 156 ± 33o in this range, indicating that periods of high solar irradiance coincide with cool conditions in the NINO3.4 region, with time lag of 14 ± 19 years. We find this result robust to the reconstruction method, estimate of solar forcing, or analysis method used to estimate the phasing. We then discuss the implication of this result for the response of tropical Pacific climate to radiative forcing. While the anti-phasing seems to favor the ``ocean dynamical thermostat'' hypothesis of Clement et al [1996], this feedback appears subdued in most IPCC-class coupled general circulation models (CGCMs), where it is almost completely compensated by changes in the Pacific trade winds, linked to changes in the vertical structures of atmospheric moisture and temperature (Knutson & Manabe 1995; Held & Soden 2006; Vecchi et al. 2006). If the reconstruction is correct that past NINO3.4 SSTs have varied out of phase with solar irradiance on bicentennial scales, this would pose a new challenge both for CGCM simulations and for our understanding of the equatorial Pacific response to radiative forcing Clement, A. C., Seager, R., Cane, M. A., and Zebiak, S. E. (1996). An ocean dynamical thermostat. J. Clim., 9(9):2190-2196. Emile-Geay, J., K. Cobb, M. Mann, and A. T. Wittenberg, Estimating Tropical Pacific SST variability over the Past Millennium. Part 1: Methodology and Validation. J. Clim., submitted. available at: http://college.usc.edu/labs/jeg/publications/. Held, Isaac M., Brian J. Soden, 2006: Robust Responses of the Hydrological Cycle to Global Warming. J. Climate, 19, 5686-5699. doi: 10.1175/JCLI3990.1 Steinhilber, F., Beer, J., and Fröhlich, C. (2009). Total solar irradiance during the Holocene. Geophys. Res. Lett., 36:L19704. Vecchi, G. A., Soden, B. J., Wittenberg, A. T., Held, I. M., Leetmaa, A., and Harrison, M. J. (2006). Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing. Nature, 441:73-76.

Martian paleolakes and waterways: Exobiological implications

USGS Publications Warehouse

Scott, D.H.; Rice, J. W.; Dohm, J.M.

1991-01-01

The problems of how warm and wet Mars once was and when climate transitions may have occurred are not well understood. Mars may have had an early environment similar to Earth's that was conductive to the ermergence of life. In addition, increasing geologic evidence indicates that water, upon which terrestrial life depends, has been present on Mars throughout its history. This evidence suggests that life could have developed not only on early Mars but also over longer periods of time in longer lasting, more clement local environments. Indications of past or present life most likely would be found in areas where liquid water existed in sufficient quantities to provide for the needs of biological systems. We suggest that paleolakes may have provided such environments. Unlike the case on Earth, this record of the origin and evolution of life has probably not been erased by extensive deformation of the Martian surface. Our work has identified eleven prospective areas where large lacustrine basins may once have existed. These areas are important for future biological, geological, and climatological investigations. ?? 1991 Kluwer Academic Publishers.

Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

NASA Technical Reports Server (NTRS)

Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

2014-01-01

The exploration of Venus continues to be a top priority of planetary science. The Planetary Decadal Survey goals for inner-planet exploration seek to discern the origin and diversity of terrestrial planets, understand how the evolution of terrestrial planets relates to the evolution of life, and explore the processes that control climate on Earth-like planets [1]. These goals can only be realized through continued and extensive exploration of Venus, the most mysterious of the terrestrial planets, remarkably different from the Earth despite the gross similarities between these twin planets. It is unknown if this apparent divergence was intrinsic, programmed during accretion from distinct nebular reservoirs, or a consequence of either measured or catastrophic processes during planetary evolution. Even if the atmosphere of Venus is a more recent development, its relationship to the resurfacing of the planets enigmatic surface is not well understood. Resolving such uncertainties directly addresses the hypothesis of a more clement, possibly water-rich era in Venus past as well as whether Earth could become more Venus-like in the future.

Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

NASA Technical Reports Server (NTRS)

Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

2015-01-01

The exploration of Venus continues to be a top priority of planetary science. The Planetary Decadal Survey goals for inner-planet exploration seek to discern the origin and diversity of terrestrial planets, understand how the evolution of terrestrial planets relates to the evolution of life, and explore the processes that control climate on Earth-like planets. These goals can only be realized through continued and extensive exploration of Venus, the most mysterious of the terrestrial planets, remarkably different from the Earth despite the gross similarities between these "twin planets". It is unknown if this apparent divergence was intrinsic, programmed during accretion from distinct nebular reservoirs, or a consequence of either measured or catastrophic processes during planetary evolution. Even if the atmosphere of Venus is a more "recent" development, its relationship to the resurfacing of the planet's enigmatic surface is not well understood. Resolving such uncertainties directly addresses the hypothesis of a more clement, possibly water-rich era in Venus' past as well as whether Earth could become more Venus-like in the future.

Paleolakes and lacustrine basins on Mars

NASA Technical Reports Server (NTRS)

Scott, David H.; Rice, James W., Jr.; Dohm, James M.

1991-01-01

The problems of how warm and wet Mars once was and when climate transitions may have occurred are not well understood. Mars may have had an early environment similar to Earth's that was conducive to the emergence of life. In addition, increasing geologic evidence indicates that water, upon which terrestrial life depends, has been present on Mars throughout its history. This evidence does not detract from the possibility that life may have originated on early Mars, but rather suggests that life could have developed over longer periods of time in longer lasting, more clement local environments than previously envisioned. It is suggested herein that such environments may have been provided by paleolakes, located mostly in the northern lowlands and probably ice covered. Such lakes probably would have had diverse origins. Glacial lakes may have occupied ice eroded hollows or formed in valleys obstructed by moraines or ice barriers. Unlike Earth, the Martian record of the origin and evolution of possible life may have not been erased by extensive deformation of the surface. Thus the basins that may have contained the paleolakes are potential sites for future biological, geological, and climatological study.

Investigating the Origin and Evolution of Venus with in Situ Mass Spectrometry

NASA Technical Reports Server (NTRS)

Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

2016-01-01

The exploration of Venus continues to be a top priority of planetary science. The Planetary Decadal Survey goals for inner-planet exploration seek to discern the origin and diversity of terrestrial planets, understand how the evolution of terrestrial planets relates to the evolution of life, and explore the processes that control climate on Earth-like planets. These goals can only be realized through continued and extensive exploration of Venus, the most mysterious of the terrestrial planets, remarkably different from the Earth despite the gross similarities between these "twin planets". It is unknown if this apparent divergence was intrinsic, programmed during accretion from distinct nebular reservoirs, or a consequence of either measured or catastrophic processes during planetary evolution. Even if the atmosphere of Venus is a more "recent" development, its relationship to the resurfacing of the planet's enigmatic surface is not well understood. Resolving such uncertainties directly addresses the hypothesis of a more clement, possibly water-rich era in Venus' past as well as whether Earth could become more Venus-like in the future.

Environmental Impact Statement for the New San Clemente Project, Monterey County, California - Regulatory Permit Application Number 16516S09.

DTIC Science & Technology

1987-09-01

through 17. Each chapter is organized in three sections: 1) a description of the environmental setting; 2) an assessment of the environmental impacts...of operation of each alternative; and 3) an assessment of the environmental impacts of construction of each alternative. The environmental impacts of...involvement is discussed in Chapter 20. Contributions to the report are listed in Chapter 21. The District and their consultants have conducted numerous

Work Systems Package/Pontoon Implacement Vehicle Operational Testing at San Clemente Island, 1979. Demonstration of a Technology for Remotely Controlled Deep-Water Recovery of Objects up to 5 Tons from Depths to 20000 Feet.

DTIC Science & Technology

1980-06-06

classes of objects, a basic inventory of hardware can be established to provide a remote recovery capabilily. Although these tests were performed in...decided to continue the operatio , ihe following day. Friday, 10 Aug 0600 Task team arrives at YD197. 0830 Dive team to lift module for inspection. The

Synthesis and Structural Characterization of New High-Valent Inorganic Fluorine Compounds and their Oxidizing Properties. Volume 2

DTIC Science & Technology

1992-02-01

a definitely related Government procurement operation, the fact ti ’it the Govern- ment may have formulated, furnished, or in any way supplied the...rapid rcxprired in which krypton is bonded to an clement other than acquisition of the free induction decays with a high-field pulse fluorine...spectroscopy is the single most powerful technique used in the structural characterization of noble gas species. This technique is especially useful in

Seasonal Changes of Bioluminescence in Photosynthetic and Heterotrophic Dinoflagellates at San Clemente Island

DTIC Science & Technology

2012-02-01

were calculated using n-2 degrees of freedom. 2.2 Nutrient and chlorophyll data Nitrate and Chl a levels were obtained from archived CalCOFI data...a later increase in photosynthetic biomass in the fall. However, Chl a levels were actually low during the period when bioluminescence was high and...for 1994-1995 which may suggest that as Chl a levels increased, so did bioluminescence cell-1 (Figure 7c). These field measurements support previous

IFLA General Conference, 1989. Division of Collections and Services. Open Forum of the Division; Section on Acquisition and Exchange; Section on Interlending and Document Delivery; Section on Serial Publications; Section on Rare and Precious Books and Documents. Booklet 50.

ERIC Educational Resources Information Center

1989

There are 20 papers in this collection from the Division of Collections and Services: "IFLA Division of Collections and Services" (Hope E. A. Clement); "Divisional Open Forum Reports" ("Section of Acquisition and Exchange" by Ulrich Montag; "Section of Government Information and Official Publications" by Bernadine Abbott Hoduski; "Section on…

Enhancing the Immune Response to Recombinant Plague Antigens

DTIC Science & Technology

2007-05-01

protection against rotavirus infection of mice stimulated by intranasal immunization with chimeric VP4 or VP6 protein. J Virol 1999;73(9):7574–81. [13] Choi...AH, Basu M, McNeal MM, Flint J, VanCott JL, Clements JD, et al. Functional mapping of protective domains and epitopes in the rotavirus VP6 protein. J...McNeal MM, Rae MN, Bean JA, Ward RL. Antibody-dependent and -independent protection following intranasal immunization of mice with rotavirus particles. J

Immunologic Control by Oral Vaccines of Diarrheal Disease Due to Enterotoxigenic Escherichia coli and shigella

DTIC Science & Technology

1986-09-01

Clements UL, Lanata C, Sears, S, Honda T, Young CR, Finkelstein RA. Evaluation in humans of attenuated Vibrio cholerae El Tor Ogawa Strain Texas Star...DE, Bareett TJ, YouW (CR, Levine WM, Blake PA. Impact of epidemic cholera in a previously uninfected island population: evaluation of a new...Sack, D.A., Wells, J.G., Feeley, J.C., Sack, R.B., Creech, W.M., Kapikian, A.Z., Gangarosa, E.J. 1976. Traveler’s flarrhea in Mexico . A Prospective

Toward Development of an Oral, Plant-Based Vaccine Against Escherichia coli O157:H7

DTIC Science & Technology

2004-01-01

Mason, H. S., Haq, T. A., Clements, J. D., and Arntzen, C. J. (1998). Edible vaccine protects mice against Escherichia coli heat-labile enterotoxin (LT...based Vaccine Against Escherichia coli O157:H7.” beyond brief excerpts is with the permission of the copyright owner, and will save and hold...4. TITLE AND SUBTITLE Toward Development of an Oral, Plant-based Vaccine Against Escherichia coli O157:H7 5a. CONTRACT NUMBER 5b. GRANT

A Comprehensive Modeling Approach Towards Understanding and Prediction of the Alaskan Coastal System Response to Changes in an Ice-diminished Arctic

DTIC Science & Technology

2009-01-01

to generate the 3 member ensembles). In total we’ve run 120 months of simulations as part of the pan-Arctic WRF evaluation. Results from the...2009: Polar atmospheric modeling in an Arctic system model, IAMAS-IAPSO-IACS MOCA-09 Joint Assembly , Montreal, Canada. Higgins, M.E. and J.J...W., and J. Clement Kinney, 2009: Oceanic Heat Contribution to Arctic Sea Ice Melt, EGU , Vienna, Austria. Maslowski, W., 2009: State of Arctic

Annual Conference on Manual Control (20th) Held in California on June 12 - 14, 1984. Volume 1

DTIC Science & Technology

1984-06-14

and in conjunction with movements of other joints. Much of this data is for atheletic performance . Components of such data can be simulated using JAMM... PERFORMANCE Chairman: Mr. Henry Jex Jewell, W. & Clement, W.F. A method for measuring the effective throughput time delay in simulated displays involving...manual control. 173 Allen, R. W. & DiMarco, R. J. Effects of transport delays on manual control system performance . 185 Sanders, K. E., Anderson, D. C

Mission Emphasis and the Determination of Needs for New Weapon Systems

DTIC Science & Technology

2009-05-01

Loveland, CO: Prosci, 2006). 61. Richard R. Nelson and Sidney G. Winter, An Evolutionary Theory of Economic Change (Cambridge, MA: The Belknap Press...of Gen Hunter Harris, USAF, (Ret.), by Col John E. Van Duyn and Maj Richard B. Clement, 7 July 1971. Typed transcript p. 32, K239.0512-403 Iris No...C. Jones, USAF, (Ret.) by Dr. Lt Col Maurice Maryanow and Dr. Richard H. Kohn, 5 August, 15-17 October 1985; 20-21 January, 13-14 March 1986

Parameters, Journal of the U.S. Army War College. Volume 17, Number 1, Spring 1987

DTIC Science & Technology

1987-01-01

way that makes sense to a reader and then explaining them. Enter the clement of judgment, which immediately puts the reporter on a slippery slope ...reformers support something they call maneuver warfare. The concept of maneuver is itself a slippery one that the reformers describe using terms such as...nuclear euthanasia . So just as the military power must have a plausible enemy, so also it must have a plausible design for countering the public threat

Proceedings of the NASTRAN (Tradename) Users’ Colloquium (17th) Held in San Antonio, Texas on 24-28 April 1989

DTIC Science & Technology

1989-03-01

statistical energy analysis , the finite clement method, and the power flow method. Experimental solutions are the most common in the literature. The authors of...to the added weights and inertias of the transducers attached to an experimental structure. Statistical energy analysis (SEA) is a computational method...Analysis and Diagnosis," Journal of Sound and Vibration, Vol. 115, No. 3, pp. 405-422 (1987). 8. Lyon, R.L., Statistical Energy Analysis of Dynamical Systems

Using Advanced Analysis Approaches to Complete Long-Term Evaluations of Natural Attenuation Processes on the Remediation of Dissolved Chlorinated Solvent Contamination

DTIC Science & Technology

2008-10-01

and UTCHEM (Clement et al., 1998). While all four of these software packages use conservation of mass as the basic principle for tracking NAPL...simulate dissolution of a single NAPL component. UTCHEM can be used to simulate dissolution of a multiple NAPL components using either linear or first...parameters. No UTCHEM a/ 3D model, general purpose NAPL simulator. Yes Virulo a/ Probabilistic model for predicting leaching of viruses in unsaturated

Isotope composition and volume of Earth's early oceans.

PubMed

Pope, Emily C; Bird, Dennis K; Rosing, Minik T

2012-03-20

Oxygen and hydrogen isotope compositions of Earth's seawater are controlled by volatile fluxes among mantle, lithospheric (oceanic and continental crust), and atmospheric reservoirs. Throughout geologic time the oxygen mass budget was likely conserved within these Earth system reservoirs, but hydrogen's was not, as it can escape to space. Isotopic properties of serpentine from the approximately 3.8 Ga Isua Supracrustal Belt in West Greenland are used to characterize hydrogen and oxygen isotope compositions of ancient seawater. Archaean oceans were depleted in deuterium [expressed as δD relative to Vienna standard mean ocean water (VSMOW)] by at most 25 ± 5‰, but oxygen isotope ratios were comparable to modern oceans. Mass balance of the global hydrogen budget constrains the contribution of continental growth and planetary hydrogen loss to the secular evolution of hydrogen isotope ratios in Earth's oceans. Our calculations predict that the oceans of early Earth were up to 26% more voluminous, and atmospheric CH(4) and CO(2) concentrations determined from limits on hydrogen escape to space are consistent with clement conditions on Archaean Earth.

Isotope composition and volume of Earth’s early oceans

PubMed Central

Pope, Emily C.; Bird, Dennis K.; Rosing, Minik T.

2012-01-01

Oxygen and hydrogen isotope compositions of Earth’s seawater are controlled by volatile fluxes among mantle, lithospheric (oceanic and continental crust), and atmospheric reservoirs. Throughout geologic time the oxygen mass budget was likely conserved within these Earth system reservoirs, but hydrogen’s was not, as it can escape to space. Isotopic properties of serpentine from the approximately 3.8 Ga Isua Supracrustal Belt in West Greenland are used to characterize hydrogen and oxygen isotope compositions of ancient seawater. Archaean oceans were depleted in deuterium [expressed as δD relative to Vienna standard mean ocean water (VSMOW)] by at most 25 ± 5‰, but oxygen isotope ratios were comparable to modern oceans. Mass balance of the global hydrogen budget constrains the contribution of continental growth and planetary hydrogen loss to the secular evolution of hydrogen isotope ratios in Earth’s oceans. Our calculations predict that the oceans of early Earth were up to 26% more voluminous, and atmospheric CH4 and CO2 concentrations determined from limits on hydrogen escape to space are consistent with clement conditions on Archaean Earth. PMID:22392985

Full orbit computations of ripple-induced fusion {alpha}-particle losses from burning tokamak plasmas

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

McClements, K.G.

A full orbit code is used to compute collisionless losses of fusion {alpha} particles from three proposed burning plasma tokamaks: the International Tokamak Experimental Reactor (ITER); a spherical tokamak power plant (STPP) [T. C. Hender, A. Bond, J. Edwards, P. J. Karditsas, K. G. McClements, J. Mustoe, D. V. Sherwood, G. M. Voss, and H. R. Wilson, Fusion Eng. Des. 48, 255 (2000)]; and a spherical tokamak components test facility (CTF) [H. R. Wilson, G. M. Voss, R. J. Akers, L. Appel, A. Dnestrovskij, O. Keating, T. C. Hender, M. J. Hole, G. Huysmans, A. Kirk, P. J. Knight, M.more » Loughlin, K. G. McClements, M. R. O'Brien, and D. Yu. Sychugov, Proceedings of the 20th IAEA Fusion Energy Conference, Invited Paper FT/3-1Ra]. It has been suggested that {alpha} particle transport could be enhanced due to cyclotron resonance with the toroidal magnetic field ripple. However, calculations for inductive operation in ITER yield a loss rate that appears to be broadly consistent with the predictions of guiding center theory, falling monotonically as the number of toroidal field coils N is increased (and hence the ripple amplitude is decreased). For STPP and CTF the loss rate does not decrease monotonically with N, but collisionless losses are generally low in absolute terms. As in the case of ITER, there is no evidence that finite Larmor radius effects would seriously degrade fusion {alpha}-particle confinement.« less

Systemic AA amyloidosis in island foxes (Urocyon littoralis): Severity and risk factors

PubMed Central

Gaffney, Patricia M.; Witte, Carmel; Clifford, Deana L.; Imai, Denise M.; O’Brien, Timothy D.; Trejo, Margarita; Liberta, Falk; Annamalai, Karthikeyan; Fändrich, Marcus; Masliah, Eliezer; Munson, Linda; Sigurdson, Christina J.

2016-01-01

Systemic amyloid A (AA) amyloidosis is highly prevalent (34%) in endangered island foxes (Urocyon littoralis) and poses a risk to species recovery. Although elevated serum amyloid A from prolonged or recurrent inflammation predisposes to AA amyloidosis, additional risk factors are poorly understood. Here we define the severity of glomerular and medullary renal amyloid and identify risk factors for AA amyloidosis in 321 island foxes necropsied from 1987 through 2010. In affected kidneys, amyloid more commonly accumulated in the medullary interstitium than in the glomeruli [98% (78/80) versus 56% (45/80), respectively, p < 0.0001], and medullary deposition was more commonly severe [19% (20/105)] as compared to glomeruli [7% (7/105), p = 0.01]. Univariate odds ratios (ORs) of severe renal AA amyloidosis were greater for short- and long-term captive foxes compared to free-ranging (OR=3.2, 3.7, respectively, overall p = 0.05) and females compared to males (OR = 2.9, p = 0.05). Multivariable logistic regression revealed independent risk factors for amyloid development were increasing age class (OR = 3.8, p < 0.0001), San Clemente Island subspecies compared to San Nicolas Island subspecies (OR = 5.3, p = 0.0003), captivity (OR = 5.1, p = 0.0001), and nephritis (OR = 2.3, p = 0.01). The increased risk associated with the San Clemente subspecies or captivity suggests roles for genetic as well as exogenous risk factors in the development of AA amyloidosis. PMID:26419399

Estimates of Eastern Equatorial Pacific Sea Surface Temperatures During the Pliocene From Carbonate 'Clumped Isotope' Thermometry

NASA Astrophysics Data System (ADS)

Thiagarajan, N.; Tripati, A.; Eiler, J.

2007-12-01

The early Pliocene (5 to 3 Ma) was an interval in Earth history that was globally warmer than the present; thus, study of the details of Pliocene climate can provide insights into the dynamics of warm climates. There are two competing models of the temperature structure of the tropical Pacific upper-ocean during the early Pliocene: the dynamical 'ocean thermostat' model [1,2] and the 'El Padre' (or permanent 'El Nino') model [3], each of which predict zonal temperature gradients and mean conditions in the Eastern Equatorial Pacific (EEP), and which differ markedly from one another in these predictions. The dynamical 'ocean thermostat' model predicts an increased temperature contrast between the Western Equatorial Pacific (WEP) and EEP, enhanced thermocline tilt and intensified upwelling under warmer conditions. In contrast, the 'El Padre' model postulates a collapse of the zonal temperature gradient, reduced thermocline tilt and a reduction in upwelling and/or warmer temperatures of upwelled waters. Existing reconstructions of tropical temperatures produce WEP sea surface temperatures which agree with each other, but yield very different results in the EEP [4,5]. We have reconstructed EEP sea surface temperatures at Ocean Drilling Program (ODP) Site 847 using a few samples spanning key intervals of the last 6 million years using carbonate clumped isotope thermometer [6,7,8]. This technique is based on the temperature dependence of the abundances of 13C-18O bonds in carbonate minerals. Initial measurements of planktonic foraminifera and coccoliths from ODP Site 847 indicate cool EEP sea surface temperatures, supporting models of Pliocene climate that have enhanced zonal temperature gradients, relative to modern. Analyses of Globigerinoides sacculifer (with sac) from sediments indicate calcification temperatures of 20.3°C ± 0.1°C and seawater δ18O values of -0.8‰ ± 0.1‰ from ~6.1 to 5.1 million years ago. Measurements of a mixed coccolith assemblage from the fine fraction of 5.6 Ma sediments show calcification temperatures of 20.4°C ± 2.3°C and seawater δ18O values of -1.4‰ ± 0.6‰. G. sacculifer (with sac) and mixed coccoliths from 1.4 Ma sediments yield calcification temperatures of 22.3°C ± 2.5°C and seawater δ18O values of 1.7‰ ± 0.7‰, and 19.4°C ± 1.8°C and seawater δ18O values of 0.4‰ ± 0.5‰, respectively. Our preliminary findings are consistent with the 'dynamical ocean thermostat' model. [1] Clement, A., et al., 1996, An Ocean Dynamical Thermostat, J. of Clim., 9, 2190-2196. [2] Cane, M., et al., 1997, Twentieth-Century Sea Surface Temperature Trends, Science, 957-960. [3] Fedorov, A., et al., 2006, The Pliocene Paradox (Mechanisms for a permanent El Nino), Science, 312, 1437-1443. [4] Rickaby, R. and Halloran, P., 2005, Cool La Nina during the warmth of the Pliocene?, Science, 307, 1948-1953. [5] Wara, M., et al. ,2005, Permanent El Nino-like conditions during the Pliocene Warm Period, Science, 309, 758-761. [6] Ghosh, P., et al., 2006, 13C-18O bonds in carbonate minerals: A new kind of paleothermometer, GCA, 70, 1439-1456. [7] Eiler, J. and Tripati, A., 2007, 'Clumped isotope' thermometry in benthic foraminifera and ostracods: A novel tool for reconstructing deep-ocean temperatures. Fall AGU. [8] Tripati, A., et al. 2007, 'Carbonate `clumped isotope' thermometry in planktonic foraminifera and coccoliths. Fall AGU.

Miocene seismic stratigraphy and structural evolution of the North and South Padre Island and OCS areas, offshore south Texas

NASA Astrophysics Data System (ADS)

Al-Ghamdi, Ali Mohammed

A seismic stratigraphy and structural study was undertaken to explain the Miocene tectonic and sedimentary evolution of the North and South Padre Island and OCS areas (offshore south Texas). Three linear, elongated growth-fault systems, trending northeast-southwest, occurred in this area: Clemente-Tomas, Corsair, and Wanda. The Clemente-Tomas and the Corsair systems were controlled by late Oligocene-early Miocene overpressured shale uplifted by an influx of clastic sediments. Salt withdrawal helped expand the Corsair fault during the late Oligocene-early Miocene, whereas salt withdrawal formed the Wanda fault system. Nine salt structures (eight diapirs and one sheet), active throughout the Miocene, occurred beneath the present-day shelf edge and in the South Padre Island East Addition. Two types of overpressured shale (overpressured shale ridges and overpressured stratified shale) are present. Seven major depocenters: four controlled by fault expansion and sediment influx, and three by sediment influx and salt withdrawal. The depocenters caused by fault expansion propagate to the northeast, whereas those related to salt withdrawal remain in the same location. Sedimentation in the depocenters was active during the early to middle Miocene. Three sediment fairways, entering the study area from the southwest, west, and northwest, appear to connect the sediment depocenters controlled by salt withdrawal and fault expansion. All sediment fairways propagated first to depocenters associated with salt withdrawal and then to upper slope areas. Lower Miocene time-structure maps of the area show ragged structural relief caused by sedimentation and shale and salt uplifts. Using well-log, seismic reflection, and paleontologic data to support the seismic stratigraphy, five cross-sections were constructed. Large-scale sedimentation occurred at the regressive sea level during the Oligocene beneath the present-day shoreline, forcing the uplift of predeposited marine sediments (shale) through differential loading. The Corsair and Clemente-Tomas faults began forming on the eastern flank of the uplifted shale. More regression occurred at sea level in late Oligocene and early Miocene times, causing the depocenter to shift basinward of the Corsair. Range of hydrocarbon maturity lies between 120sp°C and 165sp°C at NP960 (25-27.5 m.y.) and between 130sp°C and 160sp°C at SP1076 (16-17.5 m.y.) isotherms. Total basement subsidence is about 4 km (SP1076) and 3.2 km (NP960), and the crustal stretching factor (ss) is 2.0 at SP1076 and 1.65 at NP960.

Atmospheric Constraints on the Surface UV Environment of Mars at 3.9 Ga Relevant to Prebiotic Chemistry

NASA Astrophysics Data System (ADS)

Ranjan, Sukrit; Wordsworth, Robin; Sasselov, Dimitar D.

2017-08-01

Recent findings suggest that Mars may have been a clement environment for the emergence of life and may even have compared favorably to Earth in this regard. These findings have revived interest in the hypothesis that prebiotically important molecules or even nascent life may have formed on Mars and been transferred to Earth. UV light plays a key role in prebiotic chemistry. Characterizing the early martian surface UV environment is key to understanding how Mars compares to Earth as a venue for prebiotic chemistry. Here, we present two-stream, multilayer calculations of the UV surface radiance on Mars at 3.9 Ga to constrain the surface UV environment as a function of atmospheric state. We explore a wide range of atmospheric pressures, temperatures, and compositions that correspond to the diversity of martian atmospheric states consistent with available constraints. We include the effects of clouds and dust. We calculate dose rates to quantify the effect of different atmospheric states on UV-sensitive prebiotic chemistry. We find that, for normative clear-sky CO2-H2O atmospheres, the UV environment on young Mars is comparable to young Earth. This similarity is robust to moderate cloud cover; thick clouds (τcloud ≥ 100) are required to significantly affect the martian UV environment, because cloud absorption is degenerate with atmospheric CO2. On the other hand, absorption from SO2, H2S, and dust is nondegenerate with CO2, meaning that, if these constituents build up to significant levels, surface UV fluence can be suppressed. These absorbers have spectrally variable absorption, meaning that their presence affects prebiotic pathways in different ways. In particular, high SO2 environments may admit UV fluence that favors pathways conducive to abiogenesis over pathways unfavorable to it. However, better measurements of the spectral quantum yields of these pathways are required to evaluate this hypothesis definitively.

The Relationship Between Partial Contaminant Source Zone Remediation and Groundwater Plume Attenuation

NASA Astrophysics Data System (ADS)

Falta, R. W.

2004-05-01

Analytical solutions are developed that relate changes in the contaminant mass in a source area to the behavior of biologically reactive dissolved contaminant groundwater plumes. Based on data from field experiments, laboratory experiments, numerical streamtube models, and numerical multiphase flow models, the chemical discharge from a source region is assumed to be a nonlinear power function of the fraction of contaminant mass removed from the source zone. This function can approximately represent source zone mass discharge behavior over a wide range of site conditions ranging from simple homogeneous systems, to complex heterogeneous systems. A mass balance on the source zone with advective transport and first order decay leads to a nonlinear differential equation that is solved analytically to provide a prediction of the time-dependent contaminant mass discharge leaving the source zone. The solution for source zone mass discharge is coupled semi-analytically with a modified version of the Domenico (1987) analytical solution for three-dimensional reactive advective and dispersive transport in groundwater. The semi-analytical model then employs the BIOCHLOR (Aziz et al., 2000; Sun et al., 1999) transformations to model sequential first order parent-daughter biological decay reactions of chlorinated ethenes and ethanes in the groundwater plume. The resulting semi-analytic model thus allows for transient simulation of complex source zone behavior that is fully coupled to a dissolved contaminant plume undergoing sequential biological reactions. Analyses of several realistic scenarios show that substantial changes in the ground water plume can result from the partial removal of contaminant mass from the source zone. These results, however, are sensitive to the nature of the source mass reduction-source discharge reduction curve, and to the rates of degradation of the primary contaminant and its daughter products in the ground water plume. Aziz, C.E., C.J. Newell, J.R. Gonzales, P. Haas, T.P. Clement, and Y. Sun, 2000, BIOCHLOR Natural Attenuation Decision Support System User's Manual Version 1.0, US EPA Report EPA/600/R-00/008 Domenico, P.A., 1987, An analytical model for multidimensional transport of a decaying contaminant species, J. Hydrol., 91: 49-58. Sun, Y., J.N. Petersen, T.P. Clement, and R.S. Skeen, 1999, A new analytical solution for multi-species transport equations with serial and parallel reactions, Water Resour. Res., 35(1): 185-190.

Mars Exobiology: The Principles Behind The Plan For Exploration

NASA Technical Reports Server (NTRS)

DesMarais, D. J.; DeVincenzi, Donald L.; Carr, M. H.; Clark, B. C.; Farmer, J. D.; Hayes, J. M.; Holland, H.; Kerridge, J. F.; Klein, H. P.; McDonald, G. D.

1995-01-01

The search for evidence of life on Mars is a highly interdisciplinary enterprise which extends beyond the traditional life sciences. Mars conceivably had a pervasive ancient biosphere which may have persisted even to the present, but only in subsurface environments. Understanding the history of Mars' global environment, including its inventory of volatile elements, is a crucial part of the search strategy. Those deposits (minerals, sediments, etc.) which could have and retained a record of earlier biological activity must be identified and examined. While the importance of. seeking another biosphere has not diminished during the years since the Viking mission, the strategy for Mars exploration certainly has been modified by later discoveries. The Viking mission itself demonstrated that the present day surface environment of Mars is hostile to life as we know it. Thus, to search effectively for life on Mars, be it extant or extinct, we now must greatly improve our understanding of Mars the planet. Such an understanding will help us broaden our search beyond the Viking lander sites, both back in time to earlier epochs and elsewhere to other sites and beneath the surface. Exobiology involves much more than simply a search for extant life beyond Earth. It addresses the prospect of long-extinct biospheres and also the chemistry, organic and otherwise, which either led to life or which occurred on rocky planets that remained lifeless. Even a Mars without a biosphere would reveal much about life. How better to understand the origin and impact of a biosphere than to compare Earth with another similar but lifeless planet? Still, several relatively recent discoveries offer encouragement that a Martian biosphere indeed might have existed. The ancient Martian surface was extensively sculptured by volcanism and the activity of liquid water. Such observations invoke impressions of an ancient martian atmosphere and environment that resembled ancient Earth more than present-day Mars. Since Viking, we have learned that our own biosphere began prior to 3.5 billion years ago, during an early period when our solar system apparently was sustaining clement conditions on at least two of its planets. Also, we have found that microorganisms can survive, even flourish, in environments more extreme in temperature and water availability than had been previously recognized. The common ancestor of life on Earth probably was adapted to elevated temperatures, raising the possibility that hydrothermal systems played a central role in sustaining our early biosphere. If a biosphere ever arose on Mars, at least some of its constituents probably dwelled in the subsurface. Even today, conditions on Mars and Earth become more similar with increasing depth beneath their surfaces. For example, under the martian permafrost, the geothermal gradient very likely maintains liquid water in environments which resemble aquifers on Earth. Indigenous bacteria have recently been recovered from deep aquifers on Earth. Liquid groundwater very likely persisted throughout Mars' history. Thus, martian biota, if they ever existed, indeed might have survived in subsurface environments.

In the Era of Limits: A Galveston District History Update, 1976-1986

DTIC Science & Technology

1990-08-01

Sierra Club vs. Marsh. 34Maass, Muddy Waters, p. 23; Thomas M. Clement, Jr., Glenn Lopez, and Pamela T. Mountain , "Engineering a Victory for Our...great land, I’m sure. It’s got ever-thin’ a man might want-free land, free cattle, beautiful rivers, and mountains too, I hear, in the west. But...meteorologist compared it to "a gorilla with a machine gun. It goes where it wants to.൨ As sus- tained winds increased to 7 4 miles per hour, the

A Comprehensive Modeling Approach Towards Understanding and Prediction of the Alaskan Coastal System Response to Changes in an Ice-diminished Arctic

DTIC Science & Technology

2009-09-30

and 28 day spin-up times used to generate the 3 member ensembles). In total we’ve run 120 months of simulations as part of the pan-Arctic WRF...Cassano, J.J. and M.W. Seefeldt, 2009: Polar atmospheric modeling in an Arctic system model, IAMAS-IAPSO-IACS MOCA-09 Joint Assembly , Montreal, Canada...NOAA, Seattle, WA. Maslowski, W., and J. Clement Kinney, 2009: Oceanic Heat Contribution to Arctic Sea Ice Melt, EGU , Vienna, Austria. Maslowski, W

The 91st Infantry in World War I -- Analysis of an AEF Division’s Efforts to Achieve Battlefield Success

DTIC Science & Technology

2013-06-13

collaboration with John J. Pershing, “Who Won the War” ( Typescript copy held in the Duane N. Diedrich Collection, Clements Library, University of...trusted to luck.”74 73The Training and Employment of Divisions, 1918, 71. 74Diary of Lieutenant Charles H. Paul, 364th Infantry, 91st Division ( typescript ...accessed 19 May 2013). Diary of Gaylen Snow, 362nd Infantry, 91st Division. Typescript held at Brigham Young University, UT. 79 Diary of Lieutenant

Archeological Investigations in Cochiti Reservoir, New Mexico. Volume 4. Adaptive Change in the Northern Rio Grande Valley.

DTIC Science & Technology

1979-01-01

remains for the entire to irrigate their gardens of melons, squashes, onions. chiles . Cochiti region, sunflowers, and tomatoes (Clark 1928:234). Thus...red period Glaze decorated wares also occur in northern and are Agua Fria Glaze-on-red, San Clemente Glaze-polychrome, western Mexico and were...modified from Mera 1933) Group TyoeName Etimated Date of Manufacture (A.D. pre-A Los Padillas G-P 71300 to 1325? A Arenal G-P ?1315 to 13507 Agua Fria G/R

Phthalocyaninatoruthenium(II), Hexakis(dimethylsulfoxide)Phthalocyaninatoruthenium(II), and Hexadis(dimethylsulfoxide-d6)phthalocyanin-atoruthenium(II), Three Highly Selective NMR Shift Reagents.

DTIC Science & Technology

1977-07-18

dimethylsu lfoxi de-d6) phthalocyanin — atoruthenium (II), Three Highly Selective NMR Shift Reagents ( ~‘ iby j \\ / Clement K. Choy and F•lalcolm E. Kenney...Running head : Phthalocyaninatorut henium( II) Shift Reagents I NTRODUCT ION Previously, work on FePc (Pc = phthalocyanine li gand , C32H16N8) show- ing...RuPc and dimethylsulfoxide -d 6 were re cted together and the product isolated, An nmr spectrum of the product showed only phthalocyanine resorar.ces

Integrated Development of Serum Molecular Markers for Early Diagnosis of Breast Cancer

DTIC Science & Technology

2006-09-01

Fas, FasL, Cyfra 21-1, TPA/TPS, IGFBP1, S100, angiostatin, SSC, ULBP1,2,3, βHCG, MICA , HE4, SMRP, mesothelin, SAA, and TTR. The procedure we used for... MICA , S-100, DR5, mesothelin, and myeloperoxidase (MPO), ULBP-1,2, S100, angiostatin. Our results have demonstrated that the expression of CA 125, EGF...4066. (8) Adam, B. L.; Qu , Y.; Davis, J. W.; Ward, M. D.; Clements, M. A.; Cazares, L. H.; Semmes, O. J.; Schellhammer, P. F.; Yasui, Y.; Feng, Z

Mars: History of Climate Change and Evolution of the Water Cycle (Runcorn-Florensky Medal Lecture)

NASA Astrophysics Data System (ADS)

Head, James W.

2010-05-01

Atmospheric general circulation models are becoming more and more sophisticated and can now be analyzed at various scales, and include variations in atmospheric water vapor content, orbital parameters and surface properties. A wide variety of geological evidence indicates that the climate on Mars has changed during its past history. We are now approaching the time when synergism is developing between studies of the observed geological record and predictions and results of climate models. Geological evidence for climate change ranges in physical scale from layering in the polar caps and sediments, to meters-thick ice-rich layers extending from high to mid-latitudes, to kilometers-thick polar and circumpolar deposits. Clear temporal changes in the mineralogy and alteration style of surface and subsurface materials signal long-term climate change. Evidence is found throughout the geologic record of Mars, ranging from interpreted Amazonian tropical mountain glaciers to much longer term trends implied by the temporal distribution of geological features such as valley networks and outflow channels. Furthermore, there is strong evidence for changes in the hydrological cycle of Mars that reflect long-term climate change. For the last ~80% of its history (the Hesperian and Amazonian) Mars appears to have been a very cold, hyper-arid polar desert, similar to the McMurdo Dry Valleys of Antarctica. During this time, the hydrologic system on Mars has been horizontally layered, with the near-surface hydrologic cycle involving water movement between the atmosphere, polar caps, the surface and regolith at various latitudes; variations in spin-axis orbital parameters caused significant surface redistribution of ice and dust, and abundant ice has been sequestered beneath glacial debris-cover in the mid-latitudes for several hundred million years. Existing groundwater is sequestered below a globally continuous cryosphere; liquid water occasionally emerged to the surface during magmatic events that cracked or melted the cryosphere, forming outlet channels. In contrast, many believe that Mars was "warm and wet" during the first 20% of its history (the Noachian); in this scenario, there was no global cryosphere, and the hydrological cycle was vertically integrated. Geological evidence for this includes extensive valley network systems, hundreds of closed-basin and open-basin lakes, depositional fans and deltas, and integrated systems that extend for thousands of kilometers across the surface. Major outstanding questions include the causes and the duration of these more clement conditions in the Noachian, whether they led to the formation and evolution of life, why they changed in the late Noachian-Hesperian, the duration of the change, how the climate stabilized to its current state, whether any early-evolving life could survive this transition, and if so, where such life might reside today. The questions raised by the long-term climate history of Mars provide a compelling framework for future robotic and human exploration.

The Readiness to Change for Bariatric Surgery Assessment Tool: Validity, Factor Structure, and Reliability.

PubMed

Carlson, Susan M S

2017-11-01

Currently, there is no guideline or standard of practice for performing the psychiatric/psychological evaluation that is a requirement for approval for bariatric surgery. The Readiness to Change for Bariatric Surgery Assessment Tool (RCB-SAT) establishes a means for psychiatric evaluators to objectively assess the patient's cognition, beliefs, and motivation around the bariatric diet and lifestyle changes. Development of a clinical decision-making tool for assessing readiness to change in bariatric patients will be useful regarding The Strategic Plan for NIH Obesity Research. The strategic plan outlines 6 overarching themes, with the last 3 centering around creation of such a clinical decision-making tool to assess a bariatric patient's readiness to change: evaluate promising strategies for obesity prevention and treatment in realworld settings and diverse populations, harness technology and tools to advance obesity research and improve health care delivery, and facilitate integration of research results into community programs and medical practice (National Institutes of Health, 2011). The pilot tool was administered to 153 potential bariatric patients, with 61 patients completing the survey a second time. Face and content validity of the items were established through an expert review process. Principle axis factoring by means of varimax rotation with Kaiser normalization identified 15 items loading on 3 factors associated with Prochaska and DiClemente's transtheoretical model of health behavior change: precontemplation, contemplation, and action (DiClemente & Prochaska, 1998). Test-retest reliability was also established for the tool. The proposed RCB-SAT demonstrates potential for assessing a patient's readiness to change regarding the bariatric diet and lifestyle.

Effects of roads on survival of San Clemente Island foxes

USGS Publications Warehouse

Snow, N.P.; Andelt, William F.; Stanley, T.R.; Resnik, J.R.; Munson, L.

2012-01-01

Roads generate a variety of influences on wildlife populations; however, little is known about the effects of roads on endemic wildlife on islands. Specifically, road-kills of island foxes (Urocyon littoralis) on San Clemente Island (SCI), Channel Islands, California, USA are a concern for resource managers. To determine the effects of roads on island foxes, we radiocollared foxes using a 3-tiered sampling design to represent the entire population in the study area, a sub-population near roads, and a sub-population away from roads on SCI. We examined annual survival rates using nest-survival models, causes of mortalities, and movements for each sample. We found the population had high annual survival (0.90), although survival declined with use of road habitat, particularly for intermediate-aged foxes. Foxes living near roads suffered lower annual survival (0.76), resulting from high frequencies of road-kills (7 of 11 mortalities). Foxes living away from roads had the highest annual survival (0.97). Road-kill was the most prominent cause of mortality detected on SCI, which we estimated as killing 3-8% of the population in the study area annually. Based on movements, we were unable to detect any responses by foxes that minimized their risks from roads. The probabilities of road-kills increased with use of the road habitat, volume of traffic, and decreasing road sinuosity. We recommend that managers should attempt to reduce road-kills by deterring or excluding foxes from entering roads, and attempting to modify behaviors of motorists to be vigilant for foxes. ?? 2011 The Wildlife Society.

Time reversal seismic imaging using laterally reflected surface waves in southern California

NASA Astrophysics Data System (ADS)

Tape, C.; Liu, Q.; Tromp, J.; Plesch, A.; Shaw, J. H.

2010-12-01

We use observed post-surface-wave seismic waveforms to image shallow (upper 10 km) lateral reflectors in southern California. Our imaging technique employs the 3D crustal model m16 of Tape et al. (2009), which is accurate for most local earthquakes over the period range 2-30 s. Model m16 captures the resonance of the major sedimentary basins in southern California, as well as some lateral surface wave reflections associated with these basins. We apply a 3D Gaussian smoothing function (12 km horizontal, 2 km vertical) to model m16. This smoothing has the effect of suppressing synthetic waveforms within the period range of interest (3-10 s) that are associated with reflections (single and multiple) from these basins. The smoothed 3D model serves as the background model within which we propagate an ``adjoint wavefield'' comprised of time-reversed windows of post-surface-wave coda waveforms that are initiated at the respective station locations. This adjoint wavefield constructively interferes with the regular wavefield in the locations of potential reflectors. The potential reflectors are revealed in an ``event kernel,'' which is the time-integrated volumetric field for each earthquake. By summing (or ``stacking'') the event kernels from 28 well-recorded earthquakes, we identify several reflectors using this imaging procedure. The most prominent lateral reflectors occur in proximity to: the southernmost San Joaquin basin, the Los Angeles basin, the San Pedro basin, the Ventura basin, the Manix basin, the San Clemente--Santa Cruz--Santa Barbara ridge, and isolated segments of the San Jacinto and San Andreas faults. The correspondence between observed coherent coda waveforms and the imaged reflectors provides a solid basis for interpreting the kernel features as material contrasts. The 3D spatial extent and amplitude of the kernel features provide constraints on the geometry and material contrast of the imaged reflectors.

When is a failure to replicate not a type II error?

PubMed

Vasconcelos, Marco; Urcuioli, Peter J; Lionello-DeNolf, Karen M

2007-05-01

Zentall and Singer (2007) challenge our conclusion that the work-ethic effect reported by Clement, Feltus, Kaiser, and Zentall (2000) may have been a Type I error by arguing that (a) the effect has been extensively replicated and (b) the amount of overtraining our pigeons received may not have been sufficient to produce it. We believe that our conclusion is warranted because (a) the original effect has not been replicated despite multiple attempts to do so and (b) the statement that more extended overtraining may be needed itself suggests that the original effect is not reliable.

[Ancient methods of animal disease prevention in Belgium].

PubMed

Mammerickx, M

1994-06-01

The author describes traditional methods of animal disease control in Belgium and the evolution of these methods up to the present time. Evidence is drawn mainly from Belgian law. The principles of hygienic prophylaxis, which have required little modification over the passage of time, were set out at the beginning of the 18th century by Lancisi and Bates, physicians to Pope Clement XI and King George I of Great Britain, respectively. These principles were immediately incorporated into Belgian law. However, it was not until the second half of the 19th century that they were applied correctly and with success.

Implementation of the VGM Graphics System on the PDP-11/50 under the RSX-11M Operating System and Construction of a Compatible Software Driver for the Ramtek RM-9400.

DTIC Science & Technology

1982-06-01

no other. is the field of computer grapnIcs expanded, such limitations became a real liability. The inability to use one program at more tnan one...terms of these environmental factors. For example, some programs may be portable from one device to another as long as the computing environment is not...PemPOMMIN OROANI&ATIO NAMI AND A00RESS IQ. PROGRAM CLEMENT. PROJECT. TASK AREA a WORK UNiT muN9ERS Naval Postgraduate School Monterey, California 93940

Quantifying the Bering Strait Oceanic Fluxes and their Impacts on Sea-Ice and Water Properties in the Chukchi and Beaufort Seas and Western Arctic Ocean for 2013-2014

DTIC Science & Technology

2016-07-27

has provided climatologies for past and on-going Arctic modeling studies [Woodgate et al., 2005b; Clement-Kinney et al., 2014; Nguyen et al., 2016... climatology of ~ 0.8 Sv. In contrast to previous results which suggested this was previously 1/3rd due to local wind forcing [Woodgate et al., 2012], we...the 1990s climatology of ~ 2500km3/yr. This is a ~ 40% increase in freshwater flux since 2001, and is mostly (90%) due to increased flow, although

A study of kindergarten children's spatial representation in a mapping project

NASA Astrophysics Data System (ADS)

Davis, Genevieve A.; Hyun, Eunsook

2005-02-01

This phenomenological study examined kindergarten children's development of spatial representation in a year long mapping project. Findings and discussion relative to how children conceptualised and represented physical space are presented in light of theoretical notions advanced by Piaget, van Hiele, and cognitive science researchers Battista and Clements. Analyses of the processes the children used and their finished products indicate that children can negotiate meaning for complex systems of geometric concepts when given opportunities to debate, negotiate, reflect, evaluate and seek meaning for representing space. The complexity and "holistic" nature of spatial representation of young children emerged in this study.

Simulation of chemical-vapor-deposited silicon carbide for a cold wall vertical reactor

NASA Astrophysics Data System (ADS)

Lee, Y. L.; Sanchez, J. M.

1997-07-01

The growth rate of silicon carbide obtained by low-pressure chemical vapor deposition from tetramethylsilane is numerically simulated for a cold wall vertical reactor. The transport equations for momentum, heat, and mass transfer are simultaneously solved by employing the finite volume method. A model for reaction rate is also proposed in order to predict the measured growth rates [A. Figueras, S. Garelik, J. Santiso, R. Rodroguez-Clemente, B. Armas, C. Combescure, R. Berjoan, J.M. Saurel and R. Caplain, Mater. Sci. Eng. B 11 (1992) 83]. Finally, the effects of thermal diffusion on the growth rate are investigated.

When Is a Failure to Replicate Not a Type II Error?

PubMed Central

Vasconcelos, Marco; Urcuioli, Peter J; Lionello-DeNolf, Karen M

2007-01-01

Zentall and Singer (2007) challenge our conclusion that the work-ethic effect reported by Clement, Feltus, Kaiser, and Zentall (2000) may have been a Type I error by arguing that (a) the effect has been extensively replicated and (b) the amount of overtraining our pigeons received may not have been sufficient to produce it. We believe that our conclusion is warranted because (a) the original effect has not been replicated despite multiple attempts to do so and (b) the statement that more extended overtraining may be needed itself suggests that the original effect is not reliable. PMID:17575905

Planetary science. A dripping wet early Mars emerging from new pictures.

PubMed

Kerr, R A

2000-12-08

The latest images from the Red Planet, a sampling of which is shown on page 1927, are suggesting that water ponded across its equatorial region eons ago, just when life might have been emerging. Although the authors offer more than one interpretation, the one they prefer has the sediments laid down beneath broad lakes and shallow seas at a relatively clement time in the planet's history. The geologic implications of the pictures plus supportive signs from earlier missions mean that these possible lake sediments will be prime candidates for NASA missions seeking signs of past life on Mars.

Small deformations of extreme five dimensional Myers-Perry black hole initial data

NASA Astrophysics Data System (ADS)

Alaee, Aghil; Kunduri, Hari K.

2015-02-01

We demonstrate the existence of a one-parameter family of initial data for the vacuum Einstein equations in five dimensions representing small deformations of the extreme Myers-Perry black hole. This initial data set has `' symmetry and preserves the angular momenta and horizon geometry of the extreme solution. Our proof is based upon an earlier result of Dain and Gabach-Clement concerning the existence of -invariant initial data sets which preserve the geometry of extreme Kerr (at least for short times). In addition, we construct a general class of transverse, traceless symmetric rank 2 tensors in these geometries.

Development of Modeling Methods and Tools for Predicting Coupled Reactive Transport Processes in Porous Media at Multiple Scales

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

Clement, T. Prabhakar; Barnett, Mark O.; Zheng, Chunmiao

DE-FG02-06ER64213: Development of Modeling Methods and Tools for Predicting Coupled Reactive Transport Processes in Porous Media at Multiple Scales Investigators: T. Prabhakar Clement (PD/PI) and Mark O. Barnett (Auburn), Chunmiao Zheng (Univ. of Alabama), and Norman L. Jones (BYU). The objective of this project was to develop scalable modeling approaches for predicting the reactive transport of metal contaminants. We studied two contaminants, a radioactive cation [U(VI)] and a metal(loid) oxyanion system [As(III/V)], and investigated their interactions with two types of subsurface materials, iron and manganese oxyhydroxides. We also developed modeling methods for describing the experimental results. Overall, the project supportedmore » 25 researchers at three universities. Produced 15 journal articles, 3 book chapters, 6 PhD dissertations and 6 MS theses. Three key journal articles are: 1) Jeppu et al., A scalable surface complexation modeling framework for predicting arsenate adsorption on goethite-coated sands, Environ. Eng. Sci., 27(2): 147-158, 2010. 2) Loganathan et al., Scaling of adsorption reactions: U(VI) experiments and modeling, Applied Geochemistry, 24 (11), 2051-2060, 2009. 3) Phillippi, et al., Theoretical solid/solution ratio effects on adsorption and transport: uranium (VI) and carbonate, Soil Sci. Soci. of America, 71:329-335, 2007« less

High resolution crustal image of South California Continental Borderland: Reverse time imaging including multiples

NASA Astrophysics Data System (ADS)

Bian, A.; Gantela, C.

2014-12-01

Strong multiples were observed in marine seismic data of Los Angeles Regional Seismic Experiment (LARSE).It is crucial to eliminate these multiples in conventional ray-based or one-way wave-equation based depth image methods. As long as multiples contain information of target zone along travelling path, it's possible to use them as signal, to improve the illumination coverage thus enhance the image quality of structural boundaries. Reverse time migration including multiples is a two-way wave-equation based prestack depth image method that uses both primaries and multiples to map structural boundaries. Several factors, including source wavelet, velocity model, back ground noise, data acquisition geometry and preprocessing workflow may influence the quality of image. The source wavelet is estimated from direct arrival of marine seismic data. Migration velocity model is derived from integrated model building workflow, and the sharp velocity interfaces near sea bottom needs to be preserved in order to generate multiples in the forward and backward propagation steps. The strong amplitude, low frequency marine back ground noise needs to be removed before the final imaging process. High resolution reverse time image sections of LARSE Lines 1 and Line 2 show five interfaces: depth of sea-bottom, base of sedimentary basins, top of Catalina Schist, a deep layer and a possible pluton boundary. Catalina Schist shows highs in the San Clemente ridge, Emery Knoll, Catalina Ridge, under Catalina Basin on both the lines, and a minor high under Avalon Knoll. The high of anticlinal fold in Line 1 is under the north edge of Emery Knoll and under the San Clemente fault zone. An area devoid of any reflection features are interpreted as sides of an igneous plume.

Learning mathematics in two dimensions: a review and look ahead at teaching and learning early childhood mathematics with children's literature.

PubMed

Flevares, Lucia M; Schiff, Jamie R

2014-01-01

In the past 25 years an identifiable interest in using children's literature in mathematics learning emerged (Clyne and Griffiths, 1991; Welchman-Tischler, 1992; Hong, 1996; Hellwig etal., 2000; Haury, 2001). We critically review the rationales given for the use of picture books in mathematics learning, with a special focus on geometry due to its underrepresentation in this body of literature and the need for greater focus on this topic. The benefits and effectiveness of using picture books for children's mathematics learning and interest have been documented (Hong, 1996; O'Neill etal., 2004; Young-Loveridge, 2004). For geometry, although much learning of shape ideas should be hands-on, two-dimensional figures are essential to develop children's understanding of plane geometry. Books may effectively engage pre-literate children with plane shapes (van den Heuvel-Panhuizen and van den Boogaard, 2008; Skoumpourdi and Mpakopoulou, 2011) and shapes as gestalt wholes or prototypes (van Hiele, 1986; Clements etal., 1999; Hannibal, 1999). We review several guidelines and evaluative criteria for book selection, including Cianciolo (2000), Schiro (1997), Hunsader (2004), and van den Heuvel-Panhuizen and Elia (2012). Geometry concepts have proven challenging for young students, but their difficulties may stem, in part, from inadequate teacher training and professional development (Clements and Sarama, 2000; Chard etal., 2008) which lead to misconceptions (Oberdorf and Taylor-Cox, 1999; Inan and Dogan-Temur, 2010). Using picture books in teacher training may be an inviting way for early childhood teachers to enhance their own knowledge. We will examine the literature for guidance on incorporating children's literature into teacher training. In closing we will outline a comprehensive, multi-pronged agenda for best instructional practices for selection and use of children's books in mathematics activities and for teacher training.

Atmospheric Constraints on the Surface UV Environment of Mars at 3.9 Ga Relevant to Prebiotic Chemistry.

PubMed

Ranjan, Sukrit; Wordsworth, Robin; Sasselov, Dimitar D

2017-08-01

Recent findings suggest that Mars may have been a clement environment for the emergence of life and may even have compared favorably to Earth in this regard. These findings have revived interest in the hypothesis that prebiotically important molecules or even nascent life may have formed on Mars and been transferred to Earth. UV light plays a key role in prebiotic chemistry. Characterizing the early martian surface UV environment is key to understanding how Mars compares to Earth as a venue for prebiotic chemistry. Here, we present two-stream, multilayer calculations of the UV surface radiance on Mars at 3.9 Ga to constrain the surface UV environment as a function of atmospheric state. We explore a wide range of atmospheric pressures, temperatures, and compositions that correspond to the diversity of martian atmospheric states consistent with available constraints. We include the effects of clouds and dust. We calculate dose rates to quantify the effect of different atmospheric states on UV-sensitive prebiotic chemistry. We find that, for normative clear-sky CO 2 -H 2 O atmospheres, the UV environment on young Mars is comparable to young Earth. This similarity is robust to moderate cloud cover; thick clouds (τ cloud  ≥ 100) are required to significantly affect the martian UV environment, because cloud absorption is degenerate with atmospheric CO 2 . On the other hand, absorption from SO 2 , H 2 S, and dust is nondegenerate with CO 2 , meaning that, if these constituents build up to significant levels, surface UV fluence can be suppressed. These absorbers have spectrally variable absorption, meaning that their presence affects prebiotic pathways in different ways. In particular, high SO 2 environments may admit UV fluence that favors pathways conducive to abiogenesis over pathways unfavorable to it. However, better measurements of the spectral quantum yields of these pathways are required to evaluate this hypothesis definitively. Key Words: Radiative transfer-Origin of life-Mars-UV radiation-Prebiotic chemistry. Astrobiology 17, 687-708.

Comparing conditions for macrorealism: Leggett-Garg inequalities versus no-signaling in time

NASA Astrophysics Data System (ADS)

Halliwell, J. J.

2017-07-01

We consider two different types of conditions which were proposed to test macrorealism in the context of a system described by a single dichotomic variable Q . This is the view that a macroscopic system evolving in time possesses definite properties which can be determined without disturbing the future or past state. The Leggett-Garg (LG) inequalities, the most commonly studied test, are only necessary conditions for macrorealism, but, building on earlier work J. J. Halliwell, Phys. Rev. A 93, 022123 (2016), 10.1103/PhysRevA.93.022123, it is shown that when the four three-time LG inequalities are augmented with a certain set of two-time inequalities also of the LG form, Fine's theorem applies and these augmented conditions are then both necessary and sufficient. A comparison is carried out with a very different set of necessary and sufficient conditions for macrorealism, namely the no-signaling in time (NSIT) conditions proposed by J. Kofler and C. Brukner, Phys. Rev. A 87, 052115 (2013), 10.1103/PhysRevA.87.052115 and L. Clemente and J. Kofler, Phys. Rev. A 91, 062103 (2015), 10.1103/PhysRevA.91.062103, which ensure that all probabilities for Q at one and two times are independent of whether earlier or intermediate measurements are made in a given run, and do not require (but imply) the LG inequalities. We argue that tests based on the LG inequalities have the form of very weak classicality conditions and can be satisfied in the face of moderate interference effects, but those based on NSIT conditions have the form of much stronger coherence witness conditions, satisfied only for zero interference. The two tests differ in their implementation of noninvasive measurability and so are testing different notions of macrorealism: the augmented LG tests are indirect, entailing a combination of the results of different experiments with only compatible quantities measured in each experimental run, in close analogy with Bell tests, and are primarily tests for macrorealism per se; in contrast, the NSIT tests entail sequential measurements of incompatible quantities and are primarily tests for noninvasiveness.

Ultrasonic detection of solid phase mass flow ratio of pneumatic conveying fly ash

NASA Astrophysics Data System (ADS)

Duan, Guang Bin; Pan, Hong Li; Wang, Yong; Liu, Zong Ming

2014-04-01

In this paper, ultrasonic attenuation detection and weight balance are adopted to evaluate the solid mass ratio in this paper. Fly ash is transported on the up extraction fluidization pneumatic conveying workbench. In the ultrasonic test. McClements model and Bouguer-Lambert-Beer law model were applied to formulate the ultrasonic attenuation properties of gas-solid flow, which can give the solid mass ratio. While in the method of weigh balance, the averaged mass addition per second can reveal the solids mass flow ratio. By contrast these two solid phase mass ratio detection methods, we can know, the relative error is less.

Discriminative stimuli that follow a delay have added value for pigeons.

PubMed

DiGian, Kelly A; Friedrich, Andrea M; Zentall, Thomas R

2004-10-01

Clement, Feltus, Kaiser, and Zentall (2000) reported that pigeons prefer discriminative stimuli that require greater effort (more pecks) to obtain over those that require less effort. In the present experiment, we examined two variables associated with this phenomenon. First, we asked whether delay of reinforcement, presumably a relatively aversive event similar to effort, would produce similar effects. Second, we asked whether the stimulus preference produced by a prior relatively aversive event depends on its anticipation. Anticipation of delay was accomplished by signaling its occurrence. Results indicated that delays can produce preferences similar to those produced by increased effort, but only if the delays are signaled.

Within-trial contrast: when is a failure to replicate not a type I error?

PubMed

Zentall, Thomas R; Singer, Rebecca A

2007-05-01

Vasconcelos, Urcuioli, and Lionello-DeNolf (2007) report the results of five experiments that fail to replicate the results of our within-trial contrast study (Clement, Feltus, Kaiser, & Zentall, 2000) and suggest that our results may represent a Type I Error. We believe that this conclusion is not warranted because (a) there is considerable evidence in support of the effect and (b) the amount of training that they gave to their pigeons prior to test may not have been sufficient to observe the effect reliably. We suggest that when sufficient training is provided, reliable contrast can be found.

KSC-03pd1102

NASA Image and Video Library

2003-04-10

KENNEDY SPACE CENTER, FLA. -- (From left) Dean Schaaf, Barksdale site manager and NASA KSC Shuttle Process Integration Ground Operations manager, and Elliot Clement, an United Space Alliance engineer at Kennedy Space Center, inspect bagged pieces of Columbia at the Barksdale Hangar site. KSC workers are participating in the Columbia Recovery efforts at the Lufkin (Texas) Command Center, four field sites in East Texas, and the Barksdale, La., hangar site. KSC is working with representatives from other NASA Centers and with those from a number of federal, state and local agencies in the recovery effort. KSC provides vehicle technical expertise in the field to identify, collect and return Shuttle hardware to KSC.

Earth observation taken by the Expedition 29 crew

NASA Image and Video Library

2011-11-16

ISS029-E-042846 (16 Nov. 2011) --- Parts of the U.S. and Mexico are seen in this image photographed by one of the Expedition 29 crew members from the International Space Station as it flew above the Pacific Ocean on Nov. 16, 2011. The Salton Sea is in the center of the frame, with the Gulf of Cortez, Mexico's Baja California and the Colorado River in the upper right quadrant. The Los Angeles Basin and Santa Catalina and San Clemente islands are at the bottom center edge of the image. Lake Mead and the Las Vegas area of Nevada even made it into the frame in the upper left quadrant.

Global warming and tropical Pacific sea surface temperature: Why models and observations do not agree

NASA Astrophysics Data System (ADS)

Coats, Sloan; Karnauskas, Kristopher

2017-04-01

The pattern of sea surface temperature (SST) in the tropical Pacific Ocean provides an important control on global climate, necessitating an understanding of how this pattern will change in response to anthropogenic radiative forcing. State-of-the-art climate models from the Coupled Model Intercomparison Project phase 5 (CMIP5) overwhelmingly project a decrease in the tropical Pacific zonal SST gradient over the coming century. This decrease is, in part, a response of the ocean to a weakening Walker circulation in the CMIP5 models, a consequence of the mass and energy balances of the hydrologic cycle identified by Held and Soden (2006). CMIP5 models, however, are not able to reproduce the observed increase in the zonal SST gradient between 1900-2013 C.E., which we argue to be robust using advanced statistical techniques and new observational datasets. While this increase is suggestive of the ocean dynamical thermostat mechanism of Clement et al. (1996), we provide evidence that a strengthening Equatorial Undercurrent (EUC) also contributes to eastern equatorial Pacific cooling. Importantly, the strengthening EUC is a response of the ocean to a weakening Walker circulation and thus can help to reconcile the range of opposing theories and observations of anthropogenic climate change in the tropical Pacific Ocean. Because of a newly identified bias in their simulation of equatorial coupled atmosphere-ocean dynamics, however, CMIP5 models do not capture the magnitude of the response of the EUC to anthropogenic radiative forcing. Consequently, they project a continuation of the opposite to what has been observed in the real world, with potentially serious consequences for projected climate impacts that are influenced by the tropical Pacific Ocean.

[Evaluation of the implementation of the FAPACAN programme to prevent cancer behavioral risk in primary care users in the North of Spain].

PubMed

López González, M Luisa; Fernández Carreira, Jose Manuel; López González, Santiago; del Olivo del Valle Gómez, M; García Casas, Juan Bautista; Cueto Espinar, Antonio

2003-01-01

The evaluation of the process is an essential condition to correctly measure the impact of educational interventions on behaviour, its psychosocial determinants and the state of change, in the context of health promotion. The aim was to evaluate the quality of the implementation of the FAPACAN Programme, designed to prevent behavioural risk of cancer in Primary Care, and to improve its psychosocial determinants in the A.S.E. Model and the state of change according to Prochaska and DiClemente Theory. The quality of implementation was measured by means of a visit to the health centre, by filling in a checklist 'in situ', and a phone survey with the patient. Centralisation and association measures were found (Pearson and Spearman's coefficient). A multiple regression model was obtained with the score made by the patient (range of 0 to 8) and the covariables: gender, age, level of education, locality and family history of cancer. The quality scores obtained oscillate between 72% and 81% of optimum quality. Significant differences were found owing to the administrator (better with fewer years of exercise) and the patient (better with higher level of study). In general, the quality of implementation was more than sufficient, in spite of the poor provision by the health system.

New Interpretation of Crustal Extension Evidences on Mars

NASA Astrophysics Data System (ADS)

Grin, E. A.

The record of early evolution of life on Earth has been obscured by extensive surface activity. On the opposite, large fractions of the martian surface date back to an early clement epoch favorable to the needs of biological systems [1]. The upper martian surface reflects a wide variety of modifying processes which destroy the geological context. However, due to endogenic causes acting after the end of the primordial bombardment, abundant extensional structures display vertical sequences of stratigraphic units from late Noachian to early Hesperian periods [2]. Deep structural incisions in the upper crust provide unaltered strata, open flanks, and slope deposits that favor the use of an autonomous lander-rover-penetrator The strategy for an exobiology search of such an optimum site should be guided by the recent attention devoted to extensional structures and their global significance [4]. Geological evidence supporting the martian crustal extension is suggested by abundant fractures associated with the dichotomy boundary northland-south upland, i.e., Aeolis Region, and peak igneous activity (Elysium bulge). As pointed out by [5], the system of fractures correlates with the endogenic origin of the dichotomy, as related to a major difference in the thicknessof the crust. Perpendicular to this boundary, fractures of deep graben testify to a general tectonic crust relaxation. The opening of the graben, joined with compressive wrinkles, is the signature of a dynamical pervasive stress regime that implies a large scale roll-over of the upper crust over the ductile interface of a more dense mantle. This general motion is not a transport of material, as there is no thickening on the boundary of the dichotomy. The horizontal movement is due to the gravitational mechanism and differential thermal convection cells in the upper crust over the slope of the anti-flexure rigid interface consequential to Elysium bulge. The fracturation occurs as the neutral zone of the crust rises to the brittle surface of the crust. Deep extensional structures are logical sites for locating and sampling fossilized organisms from various epochs. Grabens suggest ancient lakes and the development of biological systems supported by bottom hot springs.

Circulation and multiple-scale variability in the Southern California Bight

NASA Astrophysics Data System (ADS)

Dong, Changming; Idica, Eileen Y.; McWilliams, James C.

2009-09-01

The oceanic circulation in the Southern California Bight (SCB) is influenced by the large-scale California Current offshore, tropical remote forcing through the coastal wave guide alongshore, and local atmospheric forcing. The region is characterized by local complexity in the topography and coastline. All these factors engender variability in the circulation on interannual, seasonal, and intraseasonal time scales. This study applies the Regional Oceanic Modeling System (ROMS) to the SCB circulation and its multiple-scale variability. The model is configured in three levels of nested grids with the parent grid covering the whole US West Coast. The first child grid covers a large southern domain, and the third grid zooms in on the SCB region. The three horizontal grid resolutions are 20 km, 6.7 km, and 1 km, respectively. The external forcings are momentum, heat, and freshwater flux at the surface and adaptive nudging to gyre-scale SODA reanalysis fields at the boundaries. The momentum flux is from a three-hourly reanalysis mesoscale MM5 wind with a 6 km resolution for the finest grid in the SCB. The oceanic model starts in an equilibrium state from a multiple-year cyclical climatology run, and then it is integrated from years 1996 through 2003. In this paper, the 8-year simulation at the 1 km resolution is analyzed and assessed against extensive observational data: High-Frequency (HF) radar data, current meters, Acoustic Doppler Current Profilers (ADCP) data, hydrographic measurements, tide gauges, drifters, altimeters, and radiometers. The simulation shows that the domain-scale surface circulation in the SCB is characterized by the Southern California Cyclonic Gyre, comprised of the offshore equatorward California Current System and the onshore poleward Southern California Countercurrent. The simulation also exhibits three subdomain-scale, persistent ( i.e., standing), cyclonic eddies related to the local topography and wind forcing: the Santa Barbara Channel Eddy, the Central-SCB Eddy, and the Catalina-Clemente Eddy. Comparisons with observational data reveal that ROMS reproduces a realistic mean state of the SCB oceanic circulation, as well as its interannual (mainly as a local manifestation of an ENSO event), seasonal, and intraseasonal (eddy-scale) variations. We find high correlations of the wind curl with both the alongshore pressure gradient (APG) and the eddy kinetic energy level in their variations on time scales of seasons and longer. The geostrophic currents are much stronger than the wind-driven Ekman flows at the surface. The model exhibits intrinsic eddy variability with strong topographically related heterogeneity, westward-propagating Rossby waves, and poleward-propagating coastally-trapped waves (albeit with smaller amplitude than observed due to missing high-frequency variations in the southern boundary conditions).

Learning mathematics in two dimensions: a review and look ahead at teaching and learning early childhood mathematics with children’s literature

PubMed Central

Flevares, Lucia M.; Schiff, Jamie R.

2014-01-01

In the past 25 years an identifiable interest in using children’s literature in mathematics learning emerged (Clyne and Griffiths, 1991; Welchman-Tischler, 1992; Hong, 1996; Hellwig etal., 2000; Haury, 2001). We critically review the rationales given for the use of picture books in mathematics learning, with a special focus on geometry due to its underrepresentation in this body of literature and the need for greater focus on this topic. The benefits and effectiveness of using picture books for children’s mathematics learning and interest have been documented (Hong, 1996; O’Neill etal., 2004; Young-Loveridge, 2004). For geometry, although much learning of shape ideas should be hands-on, two-dimensional figures are essential to develop children’s understanding of plane geometry. Books may effectively engage pre-literate children with plane shapes (van den Heuvel-Panhuizen and van den Boogaard, 2008; Skoumpourdi and Mpakopoulou, 2011) and shapes as gestalt wholes or prototypes (van Hiele, 1986; Clements etal., 1999; Hannibal, 1999). We review several guidelines and evaluative criteria for book selection, including Cianciolo (2000), Schiro (1997), Hunsader (2004), and van den Heuvel-Panhuizen and Elia (2012). Geometry concepts have proven challenging for young students, but their difficulties may stem, in part, from inadequate teacher training and professional development (Clements and Sarama, 2000; Chard etal., 2008) which lead to misconceptions (Oberdorf and Taylor-Cox, 1999; Inan and Dogan-Temur, 2010). Using picture books in teacher training may be an inviting way for early childhood teachers to enhance their own knowledge. We will examine the literature for guidance on incorporating children’s literature into teacher training. In closing we will outline a comprehensive, multi-pronged agenda for best instructional practices for selection and use of children’s books in mathematics activities and for teacher training. PMID:24904475

Cognitive correlates of anxious and depressive symptomatology: an examination of the Helplessness/Hopelessness model.

PubMed

Waikar, S V; Craske, M G

1997-01-01

Expectancies about future life events were assessed in anxious and depressed patients to test predictions of the Helplessness/Hopelessness model of anxiety and depression (Alloy, Kelly, Mineka, & Clements, 1990). In addition to expectancies for future events, patients from affective and anxiety treatment clinics completed anxiety and depression symptom ratings and positive and negative affects scales. Findings revealed partial support for the model. Negative outcome and helplessness expectancies were related specifically to depression. Cognitions regarding future positive events were interrelated and associated with symptom measures more strongly than were cognitions regarding negative events. Additionally, positive affects was more strongly related to depression than to anxiety symptom ratings. Implications and limitations of these findings are discussed.

Uta stansburiana and Elgaria multicarinata on the California Channel Islands: Natural dispersal or artificial introduction?

USGS Publications Warehouse

Mahoney, Meredith J.; Parks, Duncan S.M.; Fellers, Gary M.

2003-01-01

Uta stansburiana and Elgaria multicarinata occur on several California Channel Islands, and recent introduction of some populations has been suggested because of similarity in life-history traits and body size to mainland populations. We sequenced representatives of each species from mainland southern California and some of the islands on which they occur. For each species, cytochrome bsequence divergence is low across the narrow geographic area sampled. Analyses of 14 haplotypes of U. stansburiana suggest long-established residency on Santa Catalina and San Clemente Islands but more recent arrival on San Nicolas and Santa Cruz Islands. Analyses of eight haplotypes of E. multicarinata suggest these lizards may have been recently transported to San Nicolas Island.

Fools rush in where angels fear to tread Playing God with Vancouver's Supervised Injection Facility in the political borderland.

PubMed

Small, Dan

2007-01-01

Healthcare does not exist in a social vacuum. Nowhere is this more obvious than in the case of people living with active addiction who are treated as social lepers: feared, despised and socially banished from the wider human family. People with addictions, and their families, fight for survival in the moral borderland between two competing understandings of their condition. According to one understanding, addiction is a concern for the criminal justice system while according to the other it is primarily a population health issue. In one orientation, addicts are troublesome offenders, while in the other they are wounded persons in need of medical attention. These competing values form a cultural web of belief that extends far beyond healthcare to the highest political office of Canadian society. This paper examines the politics of addiction over a 6-year period beginning at the municipal level in Vancouver and culminating with a confrontation between the Prime Minister of Canada and the tiny neighbourhood that provides a home for North America's only Supervised Injection Facility. Not wanting to let the medical facts get in the way of a political stand, Prime Minister Stephen Harper and his Health Minister, Tony Clement, played God this summer by playing politics with the lives of people in the shadows of Canadian society.

Microhardness evaluation of enamel adjacent to an improved GIC sealant after different enamel pre-treatment procedures.

PubMed

Haznedaroglu, E; Sozkes, S; Mentes, A R

2014-12-01

This in vitro study was carried out to evaluate the microhardness of enamel adjacent to a glass ionomer cement (GIC) with high fluoride content used as a sealant (Fuji Triage, GC Corp., Japan) after laser, bur or air abrasion treatment procedures. 200 freshly extracted non-carious human molars were divided into 10 experimental groups according to the enamel pre-treatment method: A air abrasion (Mach 4.1 Kreativ Inc., USA); AP, Air abrasion + conditioning with 20% polyacrylic acid (GC cavity conditioner); L, Er,Cr:YSGG laser application (Waterlase, Biolase Technology, Inc., San Clemente, USA); LP, Er,Cr:YSGG laser application and fissure conditioning; B, ameloplasty carried out with a diamond bur especially designed for preparing fissures (Komet #8833); BP, ameloplasty + fissure conditioning; P, application of 20% polyacrylic acid and all fissures sealed with GIC; C, no fissure treatment, the material was applied directly to the fissures (control); R, application of 37% orthophosphoric acid and fissures sealed with a resin-based sealant (Fissurit; Voco, Germany) (control); N, no treatment (control). Half of each group of teeth were left in artificial saliva for one month and the rest for three months. The teeth were then sectioned and microhardness was measured using a Vickers test apparatus. Kruskal-Wallis, Mann-Whitney U and Dunn's multiple comparison tests were carried out (5% significance). After one month results regarding hardness at the base and lateral walls of fissures were significantly higher in groups A, AP, L, LP, B, BP, P and C than in groups R and N (p<0.01), but no difference was seen between the treatment procedures. The results after three months produced similar findings with evenly increased values for all groups. The results of this study showed that the tested GIC with a higher fluoride content seemed to improve the enamel hardness of the fissure enamel and could be regarded as an alternative material in cases where resin sealant applications are questionable.

The Search for Life from Antarctica to Mars

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; Cuzzi, Jeffrey N. (Technical Monitor)

1995-01-01

Although the Viking results may indicate that Mars has no life today, the possibility exists that Mars may hold the best record of the events that led to the origin of life. There is direct geomorphological evidence that in the past Mars had large amounts of liquid water on its surface. Atmospheric models would suggest that this early period of hydrological activity was due to the presence of a thick atmosphere and the resulting warmer temperatures. From a biological perspective the existence of liquid water, by itself motivates the question of the origin of life on Mars. From studies of the Earth's earliest biosphere we know that by 3.5 Gyr. ago, life had originated on Earth and reached a fair degree of biological sophistication. Surface activity and erosion on Earth make it difficult to trace the history of life before the 3.5 Gyr timeframe. If Mars did maintain a clement environment for longer than it took for life to originate on Earth, then the question of the origin of life on Mars follows naturally. Human exploration of Mars will probably begin with a small base manned by a temporary crew, a necessary first start. But exploration of the entire planet win require a continued presence on the Martian surface and the development of a self sustaining community in which humans can live and work for very long periods of time. A permanent Mars research base can be compared to the permanent research bases which several nations maintain in Antarctica at the South Pole, the geomagnetic pole, and elsewhere. In the long run, a continued human presence on Mars will be t he most economical way to study that planet in detail. It is possible that at some time in the future we might recreate a habitable climate on Mars, returning it to the life-bearing state it may have enjoyed early in its history. Our studies of Mars are still in a preliminary state but everything we have learned suggests that it may be possible to restore Mars to a habitable climate.

Method for measuring recovery of catalytic elements from fuel cells

DOEpatents

Shore, Lawrence [Edison, NJ; Matlin, Ramail [Berkeley, NJ

2011-03-08

A method is provided for measuring the concentration of a catalytic clement in a fuel cell powder. The method includes depositing on a porous substrate at least one layer of a powder mixture comprising the fuel cell powder and an internal standard material, ablating a sample of the powder mixture using a laser, and vaporizing the sample using an inductively coupled plasma. A normalized concentration of catalytic element in the sample is determined by quantifying the intensity of a first signal correlated to the amount of catalytic element in the sample, quantifying the intensity of a second signal correlated to the amount of internal standard material in the sample, and using a ratio of the first signal intensity to the second signal intensity to cancel out the effects of sample size.

The fourth disease, 1900-2000.

PubMed

Weisse, M E

2001-01-27

Measles and scarlet fever were differentiated from one another in the 17th century. Rubella was accepted as the third distinct paediatric exanthem in 1881. Nil Filatow in 1885 and Clement Dukes in 1894 described two distinct forms of rubella, and in 1900 Dukes proposed that one of these forms of rubella was a separate entity which he called the fourth disease. For the past five decades, fourth disease has been considered a non-entity, perhaps a mild form of scarlet fever, but certainly not a distinct disease. In 1979 Keith Powell resurrected the idea of the fourth disease and argued that it was caused by exotoxin-producing Staphylococcus aureus. We present additional arguments for the existence of fourth disease, as well as information to link the disease to S. aureus.

[Maturation diagnosis in full term hypotrophic fetuses].

PubMed

Scharnke, H D; Gartzke, J; Fleischer, G; Isbruch, E

1977-01-01

Foam-Test by Clements is a valuable method for determining the foetus maturity of lungs. We introduce this test along with other parameters for the maturity-diagnosis since one year. In 15% result, the Foam-Test was not applicable because of blood, or meconic amniotic fluid, other wise wrong negative and in 0% wrong positive results. By unmatured child, there was doubtable results with Foam-Test. Since it is important to determine the early delivery of unmatured children, particularly the case of foetus maturity of lungs must be exact, we therefore decided to use the Lecithin/Sphingomyelinquotients in some cases. The results of Lecithin/Sphingomyelinquotient in unmatured children are almost with the approximated date under two. From this, one must deduce from these children, that the intrauterine unmatured lungs lately took place.

Strike-slip faulting in the Inner California Borderlands, offshore Southern California.

NASA Astrophysics Data System (ADS)

Bormann, J. M.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.; Sahakian, V. J.; Holmes, J. J.; Klotsko, S.; Kell, A. M.; Wesnousky, S. G.

2015-12-01

In the Inner California Borderlands (ICB), offshore of Southern California, modern dextral strike-slip faulting overprints a prominent system of basins and ridges formed during plate boundary reorganization 30-15 Ma. Geodetic data indicate faults in the ICB accommodate 6-8 mm/yr of Pacific-North American plate boundary deformation; however, the hazard posed by the ICB faults is poorly understood due to unknown fault geometry and loosely constrained slip rates. We present observations from high-resolution and reprocessed legacy 2D multichannel seismic (MCS) reflection datasets and multibeam bathymetry to constrain the modern fault architecture and tectonic evolution of the ICB. We use a sequence stratigraphy approach to identify discrete episodes of deformation in the MCS data and present the results of our mapping in a regional fault model that distinguishes active faults from relict structures. Significant differences exist between our model of modern ICB deformation and existing models. From east to west, the major active faults are the Newport-Inglewood/Rose Canyon, Palos Verdes, San Diego Trough, and San Clemente fault zones. Localized deformation on the continental slope along the San Mateo, San Onofre, and Carlsbad trends results from geometrical complexities in the dextral fault system. Undeformed early to mid-Pleistocene age sediments onlap and overlie deformation associated with the northern Coronado Bank fault (CBF) and the breakaway zone of the purported Oceanside Blind Thrust. Therefore, we interpret the northern CBF to be inactive, and slip rate estimates based on linkage with the Holocene active Palos Verdes fault are unwarranted. In the western ICB, the San Diego Trough fault (SDTF) and San Clemente fault have robust linear geomorphic expression, which suggests that these faults may accommodate a significant portion of modern ICB slip in a westward temporal migration of slip. The SDTF offsets young sediments between the US/Mexico border and the eastern margin of Avalon Knoll, where the fault is spatially coincident and potentially linked with the San Pedro Basin fault (SPBF). Kinematic linkage between the SDTF and the SPBF increases the potential rupture length for earthquakes on either fault and may allow events nucleating on the SDTF to propagate much closer to the LA Basin.

The evolution of anatomical illustration and wax modelling in Italy from the 16th to early 19th centuries

PubMed Central

Riva, Alessandro; Conti, Gabriele; Solinas, Paola; Loy, Francesco

2010-01-01

Although the contribution to anatomical illustration by Vesalius and his followers has received much attention, less credit has been given to Veslingius and particularly Fabricius. By 1600, Fabricius had amassed more than 300 paintings that together made the Tabulae Pictae, a great atlas of anatomy that was highly admired by his contemporaries. Many of his new observations were incorporated into subsequent books, including those by Casserius, Spighelius, Harvey and Veslingius. Also of importance were the Tabulae by Eustachius (1552), which, although only published in 1714, greatly influenced anatomical wax modelling. In 1742, Pope Benedict XIV established a Museum of Anatomy in Bologna, entrusting to Ercole Lelli the creation of several anatomical preparations in wax. Felice Fontana realised that the production of a large number of models by the casting method would make cadaveric specimens superfluous for anatomical teaching and in 1771 he asked the Grand Duke to fund a wax-modelling workshop in Florence as part of the Natural History Museum, later known as La Specola. Fontana engaged Giuseppe Ferrini as his first modeller and then the 19-year-old Clemente Susini who, by his death in 1814, had superintended the production of, or personally made, more than 2000 models. In 1780, the Austrian Emperor Joseph II visited La Specola and ordered a great number of models for his Josephinum museum; these were made by Fontana with the help of Clemente Susini and supervised by the anatomist Paolo Mascagni. It is, however, in Cagliari that some of Susini’s greatest waxes are to be found. These were made when he was free of Fontana’s influence and were based on dissections made by Francesco Antonio Boi (University of Cagliari). Their distinctive anatomical features include the emphasis given to nerves and the absence of lymphatics in the brain, a mistake made on earlier waxes. The refined technical perfection of the anatomical details demonstrates the closeness of the cooperation between Susini and Boi, whereas the expressiveness of the faces and the harmony of colours make the models of Cagliari masterpieces of figurative art. PMID:19900181

Arnaldo Da Villanova medieval physician (1235-1311). A first approach.

PubMed

Ricciardi, Biagio; Ricciardi, Elisabetta; Ricciardi, Carlo Alberto

2016-02-01

Arnaldo de Villanova, was a Catalan Physician, born in Villanova de Grau, a suburb of Valencia - Spain about 1235. He died off the coast of Genoa in 1311 during a sea voyage departing from Messina in Sicily, during a diplomatic mission by Pope Clement V in Avignon on orders by the King of Sicily. He was a so famous and clever scientist of the thirteenth century, to give his name to the Universitary Hospital of Montpellier - France. His interests ranged from theology, to politics, medicine, and anymore alchemy. He was an adviser and physician of Kings of Aragon, like Peter III the Great (1276-1285) and James II the Right (1285-1327), of Robert of Angi (1309-1343) of Naples, and of Popes, like Innocenzo V (1276), Bonifacio VIII (1294-1303), Benedetto XI (1303-1304), Clemente V (1305-1314), and of the King of Sicily Federico II of Aragon (1296-1337). For the Pope Bonifacio VIII, suffering from renal colic due to kidney stones, he prescribed Hydrotherapy with Fiuggi Thermal water, that was specially transported for him from its source to Rome and Anagni, in jars wrapped in coarse carpets or wool fabrics, to better maintain the source temperature. In addition in July of 1301, he also produced an astrological seal (Talisman) made of gold loaded of virtues, obtained exposing the seal to the power of the Sun, in those days in the Leo Constellation. This seal was worn by the Pope in an hernial belt of leather to support the kidney,probably to improve hisnephroptosis. Arnaldo produced this seal according to what was described in the book Picatrix - The goal of the wise of the Arabic astronomer and alchemist "Abū l-Qāsim Maslama b.- Ahmad al-Majriti, known with the pseudonym Ghayat al hakim died in Cordova about 1008. Ten years later, after his mysterious death at sea on a Sicilian royal ship, his body was not buried at sea, but was reported in Sicily and buried in the Federician Castle of Montalbano of Elicona at the end of Peloritans Mountains near Milazzo, about 90 km from Messina, where he loved to stay and to write.

Area 3a in the cat. I. A reevaluation of its location and architecture on the basis of Nissl, myelin, acetylcholinesterase, and cytochrome oxidase staining.

PubMed

Avendaño, C; Verdu, A

1992-07-15

Current knowledge on the anatomy of area 3a of the cat mainly derives from the cyto- and myeloarchitectonic study of Hassler and Muhs-Clement (J Hirnforsch 6:377, 1964). Previous investigations in the cat had failed to identify a cortical region comparable to monkey's area 3a. In the present study, Nissl, myelin, acetylcholinesterase, and cytochrome oxidase staining techniques were applied to coronal and sagittal serial sections of the cat brain. Area 3a appears as a slender band of cortex between areas 4 and 3b, and in Nissl-stained sections it is mainly characterized by an attenuated granular layer IV, overlying a thin layer V with pyramidal cells of various sizes, including a few large ones. These cytoarchitectonic features are sufficient to differentiate area 3a from neighboring areas, although the borders between them are not sharp in many cases. After the Nissl staining, the acetylcholinesterase staining proved to be the most helpful in defining the structure and borders of area 3a. Acetylcholinesterase staining was dense in layer I (in contrast with a lighter staining of outer layer I in area 4), and light in layers II and IIIa, changing to moderate in IIIc and IV (a pattern which is accentuated in area 3b). Myelin and cytochrome oxidase techniques also yielded differential staining patterns of area 3a and neighboring areas 4 and 3b, although the borders were not easily drawn with these techniques. Whereas our cyto- and myeloarchitectonic findings were comparable to those of Hassler and Muhs-Clement ('64) and applied well to area 3a in the convexity of the hemisphere, we found that most of the area 3a described by these authors in the medial face of the hemisphere had a number of distinguishing architectonic (as well as connectional and physiological) features which enabled us to define it as a separate area (7m). The techniques we used to delineate area 3a are compatible with most current procedures of histo- and immunohistochemical staining of the brain, and may also provide valuable supporting data for electrophysiological studies.

An Exobiological Strategy for Mars Exploration

NASA Technical Reports Server (NTRS)

1995-01-01

The idea of searching for evidence of life on Mars may strike some as far-fetched, even fanciful. But there is a compelling logic to such a quest, as well as an equally compelling excitement. Early environments were apparently sufficiently similar on Mars and Earth, and life arose so rapidly on Earth once conditions became clement, that emergence of life on both planets at that time is scarcely less plausible than emergence on only one. Furthermore, although a fossil on Mars might seem at first like a proverbial needle in a haystack, experience on Earth tell us that if we know where to look, finding evidence of ancient life is not particularly difficult, especially when one considers that such evidence can be relatively widely disseminated in the form of chemical or isotopic signatures. The key is to recognize that the search for ancient life on Mars will involve a logically designed sequence of missions, each of which will focus on defining ever more closely where and how biosignatures may be found. Although one can never rule out a chance discovery, this quest should not be approached as one that will yield to a single, expeditious mission. (In fact, the proposed strategy lends itself particularly well to the use of a series of relatively small, inexpensive spacecraft, rather than a single flagship-class mission). The search for life on Mars will take time and commitment, but the reward could be a discovery of inestimable importance, not just to science, but to humanity as a whole.

An exobiological strategy for Mars exploration

NASA Astrophysics Data System (ADS)

1995-04-01

The idea of searching for evidence of life on Mars may strike some as far-fetched, even fanciful. But there is a compelling logic to such a quest, as well as an equally compelling excitement. Early environments were apparently sufficiently similar on Mars and Earth, and life arose so rapidly on Earth once conditions became clement, that emergence of life on both planets at that time is scarcely less plausible than emergence on only one. Furthermore, although a fossil on Mars might seem at first like a proverbial needle in a haystack, experience on Earth tell us that if we know where to look, finding evidence of ancient life is not particularly difficult, especially when one considers that such evidence can be relatively widely disseminated in the form of chemical or isotopic signatures. The key is to recognize that the search for ancient life on Mars will involve a logically designed sequence of missions, each of which will focus on defining ever more closely where and how biosignatures may be found. Although one can never rule out a chance discovery, this quest should not be approached as one that will yield to a single, expeditious mission. (In fact, the proposed strategy lends itself particularly well to the use of a series of relatively small, inexpensive spacecraft, rather than a single flagship-class mission). The search for life on Mars will take time and commitment, but the reward could be a discovery of inestimable importance, not just to science, but to humanity as a whole.

Period Changes of Type II Cepheids in the Globular Cluster M5

NASA Astrophysics Data System (ADS)

Randall, Jill M.; Rabidoux, K.; Smith, H. A.; De Lee, N.; Pritzl, B.; Osborn, W.

2007-05-01

The observed period changes of a pulsating variable star can, in principle, provide a sensitive test of the movement of the variable through the instability strip of the HR diagram. We revisit the long term period behavior of variables V42 and V84 in M5, making use of new BVI light curves of these type II Cepheids. V42 has shown a small decrease in period since 1889. The period changes of V84 are more difficult to ascertain, with possible short term changes in the observed phase of maximum light. The observed period changes, in both cases based upon observations spanning more than a century, are consistent with the earlier determinations of Coutts Clement & Sawyer Hogg (1977, JRASC, 71, 281). (This research is supported by the College of Science of the Florida Institute of Technology.)

[Projective identification, mimesis and the analytical situation. Preliminary observations].

PubMed

Ruberto, A; Lucchi, N; Senesi, P; Gaston, A

1990-01-01

In an attempt to underline the need to refer to an imaginary setting, in which the analytical relationship is acted out, the Authors have considered the possible relations between the concept of projective identification, as defined by Klein and further developed by Bion, and the idea of "Mimesis", which is inevitably involved in every story, and which confronts the imaginary at the very moment in which it is produced. The "fusion" between subject and object, which may occur in a more or less partial manner, is defined as a phenomenal demonstration of the participation of the two poles of the relationship in a "super-individual" experience which embraces them both. The mythical image of the hunter. Anyone is, in our opinion, a paradigmatic clement in this from of "meeting" which takes place within an impersonal and illusionary dimension.

Antimicrobial Efficacy of a New Chlorhexidine-based Device Against Staphylococcus aureus Colonization of Venous Catheters

PubMed Central

Kowalewska, Paulina M.; Petrik, Shawn M.; Di Fiore, Attilio E.; Fox-Robichaud, Alison E.

2018-01-01

Vascular catheters are a major cause of nosocomial bloodstream infections. ChloraLock (ATTWILL Medical Solutions, Inc, West Jordan, UT, and ICU Medical, Inc, San Clemente, CA) is a novel antimicrobial device containing chlorhexidine digluconate (CHG) that is fitted onto a syringe and infuses CHG into the catheter lumen during locking. The objective of this study was to evaluate the antimicrobial efficacy of ChloraLock with in vitro tests and its ability to reduce Staphylococcus aureus contamination of catheters in the external jugular veins of Yorkshire swine. ChloraLock significantly reduced the bacterial load in the in vitro tests by up to 6 log10 colony-forming units (CFU) and by 3 to 4 log10 CFU/lumen in vivo in a swine model with 0.9% NaCl catheter locks. PMID:29489705

Antimicrobial Efficacy of a New Chlorhexidine-based Device Against Staphylococcus aureus Colonization of Venous Catheters.

PubMed

Kowalewska, Paulina M; Petrik, Shawn M; Di Fiore, Attilio E; Fox-Robichaud, Alison E

Vascular catheters are a major cause of nosocomial bloodstream infections. ChloraLock (ATTWILL Medical Solutions, Inc, West Jordan, UT, and ICU Medical, Inc, San Clemente, CA) is a novel antimicrobial device containing chlorhexidine digluconate (CHG) that is fitted onto a syringe and infuses CHG into the catheter lumen during locking. The objective of this study was to evaluate the antimicrobial efficacy of ChloraLock with in vitro tests and its ability to reduce Staphylococcus aureus contamination of catheters in the external jugular veins of Yorkshire swine. ChloraLock significantly reduced the bacterial load in the in vitro tests by up to 6 log10 colony-forming units (CFU) and by 3 to 4 log10 CFU/lumen in vivo in a swine model with 0.9% NaCl catheter locks.

Chaotic obliquity and the nature of the Martian climate

NASA Technical Reports Server (NTRS)

Jakosky, Bruce M.; Henderson, Bradley G.; Mellon, Michael T.

1995-01-01

Recent calculations of the Martian obliquity suggests that it varies chaotically on timescales longer than about 10(exp 7) years and varies between about 0 and 60 deg. We examine the seasonal water behavior at obliquities between 40 and 60 deg. Up to several tens of centimeters of water may sublime from the polar caps each year, and possibly move to the equator, where it is more stable. The CO2 frost and CO2-H2O clathrate hydrate are stable in thepolar deposits below a few tens of meters depth, so that the polar cap could contain a significant CO2 reservoir. If CO2 is present, it could be left over from the early history of Mars; also, it could be released into the atmosphere during periods of high obliquity, causing occasional periods of more-clement climate.

Remotely sensed forest phenology and its relation with Nephropathia

NASA Astrophysics Data System (ADS)

Barrios, J. M.

2010-05-01

J.M. Barrios1, W.W. Verstraeten1, P. Maes2, J. Clement2, J-M. Aerts1, S. Amirpour1, J. Wambacq2, K. Lagrou3, M. Van Ranst2, D. Berckmans1, P. Coppin1 1. Katholieke Universiteit Leuven, Biosystems Departement, M3-BIORES, Willem de Croylaan 34, B-3001 Leuven, Belgium 2. Katholieke Universiteit Leuven, Laboratory of Clinical Virology, Hantavirus Reference Center, Rega Institute, Minderbroedersstraat 10, B-3000 Leuven, Belgium 3. Katholieke Universiteit Leuven, Department of Experimental Laboratory Medicine, Herestraat 49, B-3000 Leuven, Belgium Nephropathia epidemica (NE), a mild form of haemorrhagic fever with renal syndrome, is a zoonotic disease caused by a Hanta virus called Puumala virus in Europe. Concern about this disease has increased in recent years due to the increase in the amount of reported cases. In 2005, 2007 and 2008 the number of infected cases surpassed 300 cases per 100000 inhabitants in Belgium, which was never observed before. NE incidence is closely related to environmental conditions. The main role in the virus transmission mechanism is played by the red bank vole (Myodes glareolus), a rodent species that is native in West European broad-leaved forests (BLF) and acts as the virus reservoir. Although the link between vegetation and NE in Belgium has been underlined repeatedly in recent research works, so far little has been done towards the exploration of remote sensing techniques for analyzing vegetation systems as an input in early warning systems. This study aims at determining whether observed NE occurrence pattern in Belgium can be connected to specific trends in BLF phenology parameters. Hence, phenology information was derived from time series of the MODIS Enhanced Vegetation Index (EVI) for the period 2000-2008 in 10 major BLF in southern Belgium. EVI values were calculated from the MOD09A1 dataset which provides an estimate of the surface spectral reflectance for bands 1-7 at 500 m resolution every 8 days. Based on our preliminary results, it is concluded that one of the most remarkable phenomena taking place in BLF is the gradual increase in length of the growing season in the 2000-2007 period. This is supported by international literature. Increasing growing seasons might contribute to an increase in the availability of resources to sustain large rodent populations and in the prolongation of optimal conditions for breeding. For most of the sampled sites, the years preceding peaks in NE cases (2005, 2008) were characterised by a late end of the growing season which coincides with warmer fall seasons. This research is part of a larger effort that aims at the incorporation of remotely sensed data in the prediction and monitoring of epidemiologic diseases.

Discriminative stimuli that follow the absence of reinforcement are preferred by pigeons over those that follow reinforcement.

PubMed

Friedrich, Andrea M; Clement, Tricia S; Zentall, Thomas R

2005-08-01

Clement, Feltus, Kaiser, and Zentall (2000) found that when pigeons have to work to obtain a discriminative stimulus that is followed by reinforcement, they prefer a discriminative stimulus that requires greater effort over one that requires less effort. The authors suggested that such a preference results from the greater change in hedonic value that occurs between the more aversive event and the onset of the stimulus that signals reinforcement, a contrast effect. It was hypothesized that any stimulus that follows a relatively more aversive event would be preferred over a stimulus that follows a relatively less aversive event. In the present experiment, the authors tested the counterintuitive prediction of that theory, that pigeons should prefer a discriminative stimulus that follows the absence of reinforcement over a discriminative stimulus that follows reinforcement. Results supported the theory.

Psychology as a theoretical foundation for health education in nursing: empowerment or social control?

PubMed

Piper, S M; Brown, P A

1998-11-01

This article explores the relationship between psychology and health education and illustrates how ostensibly 'neutral' models and theories of psychology can be used by conflicting health education philosophies and ideologies. We contend both that health education is an intrinsic element of nursing (which, for the purpose of this article, also includes health visiting and midwifery) and that psychology legitimately underpins practice. Our concern in this article is in the potential application of models and theories of health-related behaviour such as the health belief model (Rosenstock et al 1988), the theory of reasoned action (Fishbein & Ajzen 1985) and the stages of change model (Prochaska & DiClemente 1982) to the health education elements of nursing practice without an awareness and scrutiny of their particular ideological standpoint, and contrasting relationships to power, and thus an understanding of the potential ambiguity regarding their role and function.

Collaborating to embrace evidence-informed management practices within Canada's health system.

PubMed

Strelioff, Wayne; Lavoie-Tremblay, Mélanie; Barton, Melissa

2007-01-01

In late 2005, 11 major national health organizations decided to work together to build healthier workplaces for healthcare providers. To do so, they created a pan-Canadian collaborative of 45 experts and asked them to develop an action strategy to improve healthcare workplaces. One of the first steps taken by members of the collaborative was to adopt the following shared belief statements to guide their thinking: "We believe it is unacceptable to fund, govern, manage, work in or receive care in an unhealthy health workplace," and, "A fundamental way to better healthcare is through healthier healthcare workplaces." This commentary provides an overview of the Quality Worklife-Quality Healthcare Collaborative action strategy. This strategy embraces the thinking set out by the lead papers (by Shamian and El-Jardali and by Clements, Dault and Priest) and brings to life evidence-informed management practices.

Advances in endoscopic balloon therapy for weight loss and its limitations

PubMed Central

Vyas, Dinesh; Deshpande, Kaivalya; Pandya, Yagnik

2017-01-01

The field of medical and surgical weight loss is undergoing an explosion of new techniques and devices. A lot of these are geared towards endoscopic approaches rather than the conventional and more invasive laparoscopic or open approach. One such recent advance is the introduction of intrgastric balloons. In this article, we discuss the recently Food and Drug Administration approved following balloons for weight loss: the Orbera™ Intragastric Balloon System (Apollo Endosurgery Inc, Austin, TX, United States), the ReShape® Integrated Dual Balloon System (ReShape Medical, Inc., San Clemente, CA, United States), and the Obalon (Obalon® Therapeutics, Inc.). The individual features of each of these balloons, the method of introduction and removal, and the expected weight loss and possible complications are discussed. This review of the various balloons highlights the innovation in the field of weight loss. PMID:29209122

Saturn Apollo Program

NASA Image and Video Library

1974-06-04

On June 4, 1974, 5 years after the successful Apollo 11 lunar landing mission, commander Neil Armstrong (right) presented a plaque to U.S. President Richard Milhous Nixon (left) on behalf of all people who had taken part in the space program. In making the presentation, Armstrong said “Mr. President, you have proclaimed this week to be United States Space week in conjunction with the fifth anniversary of our first successful landing on the Moon. It is my privilege to represent my colleagues, the crewmen of projects Mercury, Gemini, Apollo, and Skylab, and the men and women of NASA, and the hundreds of thousands of Americans from across the land who contributed so mightily to the success of our efforts in space in presenting this plaque which bears the names of each individual who has had the privilege of representing this country” in a space flight. The presentation was made at the California white house in San Clemente.

Apollo 11 Commander Armstrong Presents President With Commemorative Plaque

NASA Technical Reports Server (NTRS)

1974-01-01

On June 4, 1974, 5 years after the successful Apollo 11 lunar landing mission, commander Neil Armstrong (right) presented a plaque to U.S. President Richard Milhous Nixon (left) on behalf of all people who had taken part in the space program. In making the presentation, Armstrong said 'Mr. President, you have proclaimed this week to be United States Space week in conjunction with the fifth anniversary of our first successful landing on the Moon. It is my privilege to represent my colleagues, the crewmen of projects Mercury, Gemini, Apollo, and Skylab, and the men and women of NASA, and the hundreds of thousands of Americans from across the land who contributed so mightily to the success of our efforts in space in presenting this plaque which bears the names of each individual who has had the privilege of representing this country' in a space flight. The presentation was made at the California white house in San Clemente.

Comments on Racetrack playa: Rocks moved by wind alone

NASA Astrophysics Data System (ADS)

Sanz-Montero, M. E.; Cabestrero, Ó.; Rodríguez-Aranda, J. P.

2016-03-01

The mechanisms by which rocks move across the beds of playa lakes leaving tracks continue to be debated (Sanz-Montero and Rodríguez-Aranda, 2013; Norris et al., 2014; Sanz-Montero et al., 2015a,b; Baumgardner and Shaffer, 2015; Jones and Hooke, 2015). In this regard, the article by Jones and Hooke (Aeolian Research 19, 2015) is particularly interesting since it provides a description of these mechanisms by R. Jones who, during a storm event in 1972, was probably the first person to witness movement of rocks. The dominant meteorological conditions described by Jones during the period when the tracks were formed are, significantly, rather similar to those previously described by Clements (1952) at Little Bonnie Claire Playa (Nevada, USA). The storm conditions referred to in the article also coincide with the observations, measurements and deductions made by Sanz-Montero and Rodríguez-Aranda (2013) and Sanz-Montero et al. (2015a,b) at Altillo Chica playa lake, Central Spain. Furthermore, we were able to carry out an on-site analysis of the sedimentary structures at Racetrack playa in June 2015, allowing us to verify the similarity of the features present at both sites. Together with the important role played by gusty winds in the formation of the tracks, all the above mentioned studies point to the presence of a thin veneer of water, just a few millimeters deep, in the area of the playa lake where the rock movements occur. However, Jones and Hooke (2015) disregard the force exerted by moving water and analyze the coefficient of friction assuming that the rocks are moved by wind alone. We offer an alternative explanation for the movement of rocks both at Racetrack and Altillo Chica playa lake which considers not only the wind but also the role played by moving water in conjunction with other parameters which modify the erosion thresholds (rocks acting as obstacles) and reduce friction (benthic microorganisms).

Effect of an herbal/botanical supplement on recovery from delayed onset muscle soreness: a randomized placebo-controlled trial

PubMed Central

2014-01-01

Background We examined the effects of a proprietary herbal/botanical supplement (StemSport, Stemtech, San Clemente, CA.) suggested to increase circulating stem cells, decrease inflammation, and attenuate exercise induced muscle damage on recovery from delayed onset muscle soreness (DOMS). Methods Sixteen subjects (male = 7, female = 9; age 23.8 ± 10 years; height 171.9 ± 10 cm, mass 72.2 ± 15 kg) were randomized in a crossover, double-blind, placebo controlled trial to receive a placebo or StemSport supplement (6150 mg/day) for 14 days. DOMS was induced on day 7 for both placebo and active conditions in the non-dominant elbow flexor group with repeated eccentric repetitions. Muscle swelling (biceps girth), elbow flexor isometric strength (hand held dynamometer), muscle pain/tenderness (visual analog scale), range of motion (active elbow flexion and extension), and inflammation (hsCRP, IL6, and TNF-α) were measured at baseline and at 24 h, 48 h, 72 h, and 168 h (1 week) post eccentric exercise. The crossover washout period was ≥14 days. Results No significant condition-by-time interactions between placebo and StemSport supplementation were observed with regard to measures of pain (p = 0.59), tenderness (p = 0.71), isometric strength (p = 0.32), elbow flexion (p = 0.45), muscle swelling (p = 0.90), or inflammation (p > 0.90). Decrements in elbow extension range of motion 48 h post-exercise were less after StemSport supplementation (Δ elbow extension 48 h post; StemSport, −2.0 deg; placebo, −10 deg; p = 0.003). Conclusions These data suggest that compared to placebo, StemSport supplementation does not improve outcome measures related to muscle recovery after acute upper-arm induced DOMS. PMID:24966805

An ocean dynamical thermostat—dominant in observations, absent in climate models

NASA Astrophysics Data System (ADS)

Coats, S.; Karnauskas, K. B.

2016-12-01

The pattern of sea surface temperature (SST) in the tropical Pacific Ocean is coupled to the Walker circulation, necessitating an understanding of how this pattern will change in response to anthropogenic radiative forcing. State-of-the-art climate models from the Coupled Model Intercomparison Project phase 5 (CMIP5) overwhelmingly project a decrease in the tropical Pacific zonal SST gradient over the coming century. This decrease in the zonal SST gradient is a response of the ocean to a weakening Walker circulation in the CMIP5 models, a consequence of the mass and energy balances of the hydrologic cycle identified by Held and Soden (2006). CMIP5 models, however, are not able to reproduce the observed increase in the zonal SST gradient between 1900-2013 C.E., which we argue to be robust using advanced statistical techniques and new observational datasets. While the observed increase in the zonal SST gradient is suggestive of the ocean dynamical thermostat mechanism of Clement et al. (1996), a strengthening Equatorial Undercurrent (EUC) also contributes to eastern equatorial Pacific cooling. Importantly, the strengthening EUC is a response of the ocean to a seasonal weakening of the Walker circulation and thus can reconcile disparate observations of changes to the atmosphere and ocean in the equatorial Pacific. CMIP5 models do not capture the magnitude of this response of the EUC to anthropogenic radiative forcing potentially because of biases in the sensitivity of the EUC to changes in zonal wind stress, like the weakening Walker circulation. Consequently, they project a continuation of the opposite to what has been observed in the real world, with potentially serious consequences for projected climate impacts that are influenced by the tropical Pacific.

Illumination discrimination in the absence of a fixed surface-reflectance layout

PubMed Central

Radonjić, Ana; Ding, Xiaomao; Krieger, Avery; Aston, Stacey; Hurlbert, Anya C.; Brainard, David H.

2018-01-01

Previous studies have shown that humans can discriminate spectral changes in illumination and that this sensitivity depends both on the chromatic direction of the illumination change and on the ensemble of surfaces in the scene. These studies, however, always used stimulus scenes with a fixed surface-reflectance layout. Here we compared illumination discrimination for scenes in which the surface reflectance layout remains fixed (fixed-surfaces condition) to those in which surface reflectances were shuffled randomly across scenes, but with the mean scene reflectance held approximately constant (shuffled-surfaces condition). Illumination discrimination thresholds in the fixed-surfaces condition were commensurate with previous reports. Thresholds in the shuffled-surfaces condition, however, were considerably elevated. Nonetheless, performance in the shuffled-surfaces condition exceeded that attainable through random guessing. Analysis of eye fixations revealed that in the fixed-surfaces condition, low illumination discrimination thresholds (across observers) were predicted by low overall fixation spread and high consistency of fixation location and fixated surface reflectances across trial intervals. Performance in the shuffled-surfaces condition was not systematically related to any of the eye-fixation characteristics we examined for that condition, but was correlated with performance in the fixed-surfaces condition. PMID:29904786

Isolation of iron bacteria from terrestrial and aquatic environments

NASA Astrophysics Data System (ADS)

Schmidt, Bertram; Szewzyk, Ulrich

2010-05-01

Bacteria, which are capable of iron oxidation or at least iron deposition are widely distributed in environments where zones of dissolved ferrous iron and oxygen gradients are overlapping [1]. They take part in the biological cycling of iron and influence other cycles of elements for example carbon [2]. Manganese can be used for similar metabolic purposes as iron, because it can be biologically oxidized by chemolithotrophs or can be reduced by respirating bacteria as well [3, 4]. Bacterial activity is responsible for the accumulation of ferric iron compounds in their surroundings. The formation of bog ore is a well known example for a soil horizon, with an extreme enrichment of biogenic ferric iron [5]. We focused on the isolation of neutrophilic iron bacteria and bacteria capable of manganese oxidation. We used samples from Tierra del Fuego (Argentina) the National Park "Unteres Odertal" (Germany) and Berlin ground water wells. Microscopic examination of the samples revealed a considerable diversity of iron encrusted structures of bacterial origin. Most of these morphologic types are already well known. The taxonomic classification of many of these organisms is based on morphologic features and is not reliable compared to recent methods of molecular biology. That is mainly due to the fact, that most of these bacteria are hardly culturable or do not show their characteristic morphologic features under culture conditions. We established a collection of more than 300 iron depositing strains. Phylogenetic analyses showed that we have many yet uncultured strains in pure culture. We obtained many isolates which form distinct branches within long known iron bacteria groups like the Sphaerotilus-Leptothrix cluster. But some of the strains belong to groups, which have not yet been associated with iron oxidation activity. The strains deposit high amounts of oxidized iron and manganese compounds under laboratory conditions. However it is unclear if these precipitations are due to biological oxidation or biological deposition of chemically oxidized iron. We examined the morphologic characteristics of selected isolates under near-natural conditions to assign them to morphologic structures which occur in native samples. Our aim for the future is to describe several strains. References: [1] Weber, K. A. ; Achenbach, L. A. ; Coates, J. D. : Microorganisms pumping iron: anaerobic microbial iron oxidation and reduction. In: Nature Reviews Microbiology 4 (2006) 752-764 [2] Van Capellen, P. ; Wang Y. : Cycling of iron and manganese in surface sediments: a general theory for the coupled transport and reaction of carbon, oxygen, nitrogen, sulfur, iron and manganese. In: American Journal of Science 296 (1996) 197-243 [3] Tebo, B. M. ; Bargar, J. R. ; Clement, B. G. ; Dick, G. J. ; Murray, K. J. ; Parker, D. Verity R. ; Webb, S. M. : Biogenic manganese oxides: properties and mechanisms of formation. In: Annual Reviews Earth Planet Science 32 (2004) 287-328 [4] Erlich, H. L. : Manganese oxide reduction as a form of anaerobic respiration. In: Geomicrobiology Journal 5 (1987) 423-431 [5] Ghiorse W. C. : Biology of iron- and manganese-depositing bacteria. In: Annual Reviews 38 (1984) 515-550

A warm or a cold early Earth? New insights from a 3-D climate-carbon model

NASA Astrophysics Data System (ADS)

Charnay, Benjamin; Le Hir, Guillaume; Fluteau, Frédéric; Forget, François; Catling, David C.

2017-09-01

Oxygen isotopes in marine cherts have been used to infer hot oceans during the Archean with temperatures between 60 °C (333 K) and 80 °C (353 K). Such climates are challenging for the early Earth warmed by the faint young Sun. The interpretation of the data has therefore been controversial. 1D climate modeling inferred that such hot climates would require very high levels of CO2 (2-6 bars). Previous carbon cycle modeling concluded that such stable hot climates were impossible and that the carbon cycle should lead to cold climates during the Hadean and the Archean. Here, we revisit the climate and carbon cycle of the early Earth at 3.8 Ga using a 3D climate-carbon model. We find that CO2 partial pressures of around 1 bar could have produced hot climates given a low land fraction and cloud feedback effects. However, such high CO2 partial pressures should not have been stable because of the weathering of terrestrial and oceanic basalts, producing an efficient stabilizing feedback. Moreover, the weathering of impact ejecta during the Late Heavy Bombardment (LHB) would have strongly reduced the CO2 partial pressure leading to cold climates and potentially snowball Earth events after large impacts. Our results therefore favor cold or temperate climates with global mean temperatures between around 8 °C (281 K) and 30 °C (303 K) and with 0.1-0.36 bar of CO2 for the late Hadean and early Archean. Finally, our model suggests that the carbon cycle was efficient for preserving clement conditions on the early Earth without necessarily requiring any other greenhouse gas or warming process.

Mega-Impacts on Mars: Implications for the Late Heavy Bombardment in the Inner Solar System, and the Early Evolution of the Earth and Mars

NASA Technical Reports Server (NTRS)

Frey, Herbert

2012-01-01

There are about 30 very large impact basins on Mars, > 1000 km in diameter, most of which are revealed by their topographic and/or crustal thickness signatures. Crater retention ages and model absolute ages suggest these all formed in a relatively short time (100-200 million years?), perhaps during a "Late Heavy Bombardment" (LHB) caused by the evolution of the orbits of the giant planets. This so-called "Nice Model" of planetary formation may explain the LHB on the Moon at about 3.9 billion years ago and would have produced a similar bombardment throughout the inner solar system. The formation of 30 very large impact basins would have had catastrophic environmental consequences for Mars, which were further complicated by the demise of the global magnetic field at about the same time. If there are no very large basins on Mars older than the 30 we see and the LHB really lasted everywhere only a short time, there may have been a relatively longer time (400 million years?) during which Mars and the Earth suffered no major impact trauma and during which conditions on both worlds may have been far more habitable than during the LHB. However, if the formation of the Mars crustal dichotomy was due to an even larger giant impact that predated the very large basins, all record of this earlier and possibly more clement time on Mars may have been erased. Ages of the smaller but still very large basins can be used to approximately date the giant impact (if it occurred). Even the very large basins appear to have reset the crater retention ages of the entire crust of Mars and may have by themselves erased any record of an earlier time.

Failure to replicate the 'work ethic" effect in pigeons.

PubMed

Vasconcelos, Marco; Urcuioli, Peter J; Lionello-DeNolf, Karen M

2007-05-01

We report six unsuccessful attempts to replicate the "work ethic" phenomenon reported by Clement, Feltus, Kaiser, and Zentall (2000). In Experiments 1-5, pigeons learned two simultaneous discriminations in which the S+ and S- stimuli were obtained by pecking an initial stimulus once or multiple (20 or 40) times. Subsequent preference tests between the S+ stimuli and between the S- stimuli mostly revealed indifference, on average, between the S+ from the multiple-peck (high-effort) trials and the S+ from the one-peck (low-effort) trials, and likewise between the two respective Sstimuli. Using a slightly different procedure that permitted assessment of the relative aversiveness of low versus high effort, Experiment 6 again revealed a pattern of indifference despite showing that pigeons took considerably longer to begin pecking on high- than on low-effort trials. Our findings call into question the reliability of the original findings and the sufficiency of the hypothesized within-trial contrast mechanism to produce them.

VizieR Online Data Catalog: RR Lyrae in 15 Galactic globular clusters (Dambis+, 2014)

NASA Astrophysics Data System (ADS)

Dambis, A. K.; Rastorguev, A. S.; Zabolotskikh, M. V.

2014-11-01

Last year, the WISE All-Sky Data Release (Cutri et al., 2012, Cat. II/328) was made public, mapping the entire sky in four mid-infrared bands W1, W2, W3 and W4 with the effective wavelengths of 3.368, 4.618, 12.082 and 22.194um, respectively. We cross-correlated the WISE single-exposure data base with the Catalogue of Galactic globular-cluster variables by Clement et al. (2001AJ....122.2587C), the Catalogue of Accurate Equatorial Coordinates for Variable Stars in Globular Clusters by Samus et al. (2009PASP..121.1378S, Cat. J/PASP/121/1378) and the catalogue of Sawyer Hogg (1973PDDO....3....6S, Cat. V/97) (for ω Cen, NGC 6723 and NGC 6934) to compute (via Fourier fits) the intensity-mean average W1- and W2-band magnitudes, and , for a total of 357 and 272 RR Lyrae type variables in 15 and 9 Galactic globular clusters, respectively. (1 data file).

Source identification of coarse particles in the Desert ...

EPA Pesticide Factsheets

The Desert Southwest Coarse Particulate Matter Study was undertaken to further our understanding of the spatial and temporal variability and sources of fine and coarse particulate matter (PM) in rural, arid, desert environments. Sampling was conducted between February 2009 and February 2010 in Pinal County, AZ near the town of Casa Grande where PM concentrations routinely exceed the U.S. National Ambient Air Quality Standards (NAAQS) for both PM10 and PM2.5. In this desert region, exceedances of the PM10 NAAQS are dominated by high coarse particle concentrations, a common occurrence in this region of the United States. This work expands on previously published measurements of PM mass and chemistry by examining the sources of fine and coarse particles and the relative contribution of each to ambient PM mass concentrations using the Positive Matrix Factorization receptor model (Clements et al., 2014). Highlights • Isolation of coarse particles from fine particle sources. • Unique chemical composition of coarse particles. • Role of primary biological particles on aerosol loadings.

Yeast-2-Hybrid data file showing progranulin interactions in human fetal brain and bone marrow libraries.

PubMed

Tegeder, Irmgard

2016-12-01

Progranulin deficiency in humans is associated with neurodegeneration. Its mechanisms are not yet fully understood. We performed a Yeast-2-Hybrid screen using human full-length progranulin as bait to assess the interactions of progranulin. Progranulin was screened against human fetal brain and human bone marrow libraries using the standard Matchmaker technology (Clontech). This article contains the full Y2H data table, including blast results and sequences, a sorted table according to selection criteria for likely positive, putatively positive, likely false and false preys, and tables showing the gene ontology terms associated with the likely and putative preys of the brain and bone marrow libraries. The interactions with autophagy proteins were confirmed and functionally analyzed in "Progranulin overexpression in sensory neurons attenuates neuropathic pain in mice: Role of autophagy" (C. Altmann, S. Hardt, C. Fischer, J. Heidler, H.Y. Lim, A. Haussler, B. Albuquerque, B. Zimmer, C. Moser, C. Behrends, F. Koentgen, I. Wittig, M.H. Schmidt, A.M. Clement, T. Deller, I. Tegeder, 2016) [1].

Adapting the transtheoretical model of change to the bereavement process.

PubMed

Calderwood, Kimberly A

2011-04-01

Theorists currently believe that bereaved people undergo some transformation of self rather than returning to their original state. To advance our understanding of this process, this article presents an adaptation of Prochaska and DiClemente's transtheoretical model of change as it could be applied to the journey that bereaved individuals experience. This theory is unique because it addresses attitudes, intentions, and behavioral processes at each stage; it allows for a focus on a broader range of emotions than just anger and depression; it allows for the recognition of two periods of regression during the bereavement process; and it adds a maintenance stage, which other theories lack. This theory can benefit bereaved individuals directly and through the increased awareness among counselors, family, friends, employers, and society at large. This theory may also be used as a tool for bereavement programs to consider whether they are meeting clients' needs throughout the transformation change bereavement process rather than only focusing on the initial stages characterized by intense emotion.

Eliciting change in at-risk elders (ECARE): evaluation of an elder abuse intervention program.

PubMed

Mariam, Lydia Morris; McClure, Regina; Robinson, J B; Yang, Janet A

2015-01-01

The current study evaluated the effectiveness of a community-based elder abuse intervention program that assists suspected victims of elder abuse and self-neglect through a partnership with local law enforcement. This program, Eliciting Change in At-Risk Elders, involves building alliances with the elder and family members, connecting the elder to supportive services that reduce risk of further abuse, and utilizing motivational interviewing-type skills to help elders overcome ambivalence regarding making difficult life changes. Risk factors of elder abuse decreased over the course of the intervention and nearly three-quarters of participants made progress on their treatment goal, advancing at least one of Prochaska and DiClemente's (1983) stages of change (precontemplation, contemplation, preparation, action, and maintenance). Forty-three percent of elders moved into the stages of action and maintenance regarding their goal. The usefulness of eliciting change via longer-term relationships with vulnerable elders in entrenched elder abuse situations is discussed.

Fish community reassembly after a coral mass mortality: higher trophic groups are subject to increased rates of extinction.

PubMed

Alonso, David; Pinyol-Gallemí, Aleix; Alcoverro, Teresa; Arthur, Rohan

2015-05-01

Since Gleason and Clements, our understanding of community dynamics has been influenced by theories emphasising either dispersal or niche assembly as central to community structuring. Determining the relative importance of these processes in structuring real-world communities remains a challenge. We tracked reef fish community reassembly after a catastrophic coral mortality in a relatively unfished archipelago. We revisited the stochastic model underlying MacArthur and Wilson's Island Biogeography Theory, with a simple extension to account for trophic identity. Colonisation and extinction rates calculated from decadal presence-absence data based on (1) species neutrality, (2) trophic identity and (3) site-specificity were used to model post-disturbance reassembly, and compared with empirical observations. Results indicate that species neutrality holds within trophic guilds, and trophic identity significantly increases overall model performance. Strikingly, extinction rates increased clearly with trophic position, indicating that fish communities may be inherently susceptible to trophic downgrading even without targeted fishing of top predators. © 2015 John Wiley & Sons Ltd/CNRS.

MECHANICS OF THE LUNG IN THE 20TH CENTURY

PubMed Central

Mitzner, Wayne

2015-01-01

Major advances in respiratory mechanics occurred primarily in the latter half of the 20th century, and this is when much of our current understanding was secured. The earliest and ancient investigations involving respiratory physiology and mechanics were often done in conjunction with other scientific activities and often lacked the ability to make quantitative measurements. This situation changed rapidly in the 20th century, and this relatively recent history of lung mechanics has been greatly influenced by critical technological advances and applications, which have made quantitative experimental testing of ideas possible. From the spirometer of Hutchinson, to the pneumotachograph of Fleisch, to the measurement of esophageal pressure, to the use of the Wilhelmy balance by Clements, to the unassuming strain gauges for measuring pressure and rapid paper and electronic chart recorders, these enabling devices have generated numerous quantitative experimental studies with greatly increased physiologic understanding and validation of mechanistic theories of lung function in health and disease. PMID:23733695

The search for life on Europa: limiting environmental factors, potential habitats, and Earth analogues.

PubMed

Marion, Giles M; Fritsen, Christian H; Eicken, Hajo; Payne, Meredith C

2003-01-01

The putative ocean of Europa has focused considerable attention on the potential habitats for life on Europa. By generally clement Earth standards, these Europan habitats are likely to be extreme environments. The objectives of this paper were to examine: (1) the limits for biological activity on Earth with respect to temperature, salinity, acidity, desiccation, radiation, pressure, and time; (2) potential habitats for life on Europa; and (3) Earth analogues and their limitations for Europa. Based on empirical evidence, the limits for biological activity on Earth are: (1) the temperature range is from 253 to 394 K; (2) the salinity range is a(H2O) = 0.6-1.0; (3) the desiccation range is from 60% to 100% relative humidity; (4) the acidity range is from pH 0 to 13; (5) microbes such as Deinococcus are roughly 4,000 times more resistant to ionizing radiation than humans; (6) the range for hydrostatic pressure is from 0 to 1,100 bars; and (7) the maximum time for organisms to survive in the dormant state may be as long as 250 million years. The potential habitats for life on Europa are the ice layer, the brine ocean, and the seafloor environment. The dual stresses of lethal radiation and low temperatures on or near the icy surface of Europa preclude the possibility of biological activity anywhere near the surface. Only at the base of the ice layer could one expect to find the suitable temperatures and liquid water that are necessary for life. An ice layer turnover time of 10 million years is probably rapid enough for preserving in the surface ice layers dormant life forms originating from the ocean. Model simulations demonstrate that hypothetical oceans could exist on Europa that are too cold for biological activity (T < 253 K). These simulations also demonstrate that salinities are high, which would restrict life to extreme halophiles. An acidic ocean (if present) could also potentially limit life. Pressure, per se, is unlikely to directly limit life on Europa. But indirectly, pressure plays an important role in controlling the chemical environments for life. Deep ocean basins such as the Mariana Trench are good analogues for the cold, high-pressure ocean of Europa. Many of the best terrestrial analogues for potential Europan habitats are in the Arctic and Antarctica. The six factors likely to be most important in defining the environments for life on Europa and the focus for future work are liquid water, energy, nutrients, low temperatures, salinity, and high pressures.

Breakdown Conditioning Chacteristics of Precision-Surface-Treatment-Electrode in Vacuum

NASA Astrophysics Data System (ADS)

Kato, Kastumi; Fukuoka, Yuji; Inagawa, Yukihiko; Saitoh, Hitoshi; Sakaki, Masayuki; Okubo, Hitoshi

Breakdown (BD) characteristics in vacuum are strongly dependent on the electrode surface condition, like the surface roughness etc. Therefore, in order to develop a high voltage vacuum circuit breaker, it is important to optimize the surface treatment process. This paper discusses about the effect of precision-surface-treatment of the electrode on breakdown conditioning characteristics under non-uniform electric field in vacuum. Experimental results reveal that the electrode surface treatment affects the conditioning process, especially the BD voltage and the BD field strength at the initial stage of the conditioning.

The slip resistance of common footwear materials measured with two slipmeters.

PubMed

Chang, W R; Matz, S

2001-12-01

The slip resistance of 16 commonly used footwear materials was measured with the Brungraber Mark II and the English XL on 3 floor surfaces under surface conditions of dry, wet, oily and oily wet. Three samples were used for each material combination and surface condition. The results of a one way ANOVA analysis indicated that the differences among different samples were statistically significant for a large number of material combinations and surface conditions. The results indicated that the ranking of materials based on their slip resistance values depends highly on the slipmeters, floor surfaces and surface conditions. For contaminated surfaces including wet, oily and oily wet surfaces, the slip resistance obtained with the English XL was usually higher than that measured with the Brungraber Mark II. The correlation coefficients between the slip resistance obtained with these two slipmeters calculated for different surface conditions indicated a strong correlation with statistical significance.

Effects of oxygen chemical potential on the anisotropy of the adsorption properties of Zr surfaces.

PubMed

Zhang, Hai-Hui; Xie, Yao-Ping; Yao, Mei-Yi; Xu, Jing-Xiang; Zhang, Jin-Long; Hu, Li-Juan

2018-05-30

The anisotropy of metal oxidation is a fundamental issue, and the oxidation of Zr surfaces also attracts much attention due to the application of Zr alloys as cladding materials for nuclear fuels in nuclear power plants. In this study, we systematically investigate the diagram of O adsorption on low Miller index Zr surfaces by using first-principles calculations based on density functional theory calculations. We find that O adsorption on the basal surface, Zr(0001), is more favourable than that on the prism surfaces, Zr(112[combining macron]0) and Zr(101[combining macron]0), under strong O-reducing conditions, while O adsorption on the prism surface is more favourable than that of the basal surface under weak O-reducing conditions and the O-rich conditions. Our findings reveal that the anisotropy of adsorption properties of O on the Zr surfaces is dependent on the O chemical potential in the environment. Furthermore, the ability of the prism for O adsorption is stronger than that of the basal surface under the O-rich condition, which is consistent with the experimental observation that the oxidation of the prism Zr surface is easier than that of the basal surface. Systematic surveys show the adsorption ability of the surface under strong O-reducing conditions is determined by the low coordination numbers of surface atoms and surface geometrical structures, while the adsorption ability of the surface under weak O-reducing conditions and O-rich conditions is only determined by the low coordination number of surface atoms. These results can provide an atomic scale understanding of the initial oxidation of Zr surfaces, which inevitably affects the growth of protective passivation layers that play critical roles in the corrosion resistance of Zr cladding materials.

Chemical nonequilibrium Navier-Stokes solutions for hypersonic flow over an ablating graphite nosetip

NASA Technical Reports Server (NTRS)

Chen, Y. K.; Henline, W. D.

1993-01-01

The general boundary conditions including mass and energy balances of chemically equilibrated or nonequilibrated gas adjacent to ablating surfaces have been derived. A computer procedure based on these conditions was developed and interfaced with the Navier-Stokes solver for predictions of the flow field, surface temperature, and surface ablation rates over re-entry space vehicles with ablating Thermal Protection Systems (TPS). The Navier-Stokes solver with general surface thermochemistry boundary conditions can predict more realistic solutions and provide useful information for the design of TPS. A test case with a proposed hypersonic test vehicle configuration and associated free stream conditions was developed. Solutions with various surface boundary conditions were obtained, and the effect of nonequilibrium gas as well as surface chemistry on surface heating and ablation rate were examined. The solutions of the GASP code with complete ablating surface conditions were compared with those of the ASC code. The direction of future work is also discussed.

Effective surface and boundary conditions for heterogeneous surfaces with mixed boundary conditions

NASA Astrophysics Data System (ADS)

Guo, Jianwei; Veran-Tissoires, Stéphanie; Quintard, Michel

2016-01-01

To deal with multi-scale problems involving transport from a heterogeneous and rough surface characterized by a mixed boundary condition, an effective surface theory is developed, which replaces the original surface by a homogeneous and smooth surface with specific boundary conditions. A typical example corresponds to a laminar flow over a soluble salt medium which contains insoluble material. To develop the concept of effective surface, a multi-domain decomposition approach is applied. In this framework, velocity and concentration at micro-scale are estimated with an asymptotic expansion of deviation terms with respect to macro-scale velocity and concentration fields. Closure problems for the deviations are obtained and used to define the effective surface position and the related boundary conditions. The evolution of some effective properties and the impact of surface geometry, Péclet, Schmidt and Damköhler numbers are investigated. Finally, comparisons are made between the numerical results obtained with the effective models and those from direct numerical simulations with the original rough surface, for two kinds of configurations.

Limits to Creation of Oxygen-Rich Atmospheres on Planets in the Outer Reaches of the Conventional Habitable Zone

NASA Technical Reports Server (NTRS)

Zahnle, Kevin

2017-01-01

Abundant free oxygen appears to be a requirement for macroflora and macrofauna. To the best of our knowledge, a general discussion of which habitable planets are conducive to oxygen has not taken place. Theories for the rise of oxygen fall into 4 categories: (i) It is governed by an intrinsic rate of biological innovation, independent of environmental factors. (ii) It is caused by mantle evolution, probably consequent to secular cooling. (iii) It is caused by hydrogen escape, which irreversibly oxidizes the Earth. (iv) It is Gaia's response to the brightening Sun, its rise prevented until reduced greenhouse gases were no longer needed to maintain a clement climate. All but the first of these make implicit astronomical predictions that can be quantified and made explicit. Here we address the third hypothesis. In this hypothesis hydrogen escape acts like an hourglass that continues until all relevant reduced mineral buffers have been oxidized (titrated, as it were) and the surface made safe for O2. The hypothesis predicts that abundant free O2 will be absent from habitable planets that have not experienced significant hydrogen escape. Where hydrogen escape is modest or insignificant, the atmosphere can be approximated as hydrostatic, which makes assessing radiative cooling by embedded molecules, atoms, and ions such as CO2 and H3+ straightforward. In particular, H2 is efficient at exciting non-LTE CO2 15 micron emission, which makes radiative cooling very effective when H2 is abundant. We can therefore map out the region of phase space in which habitable planets do not lose hydrogen, and therefore do not develop O2 atmospheres. A related matter is the power of radiative cooling by embedded molecules to enforce the diffusion limit to hydrogen escape. This matter in particular is relevant to addressing the empirical observation that rocky planets with thin or negligible atmospheres are rarely or never bigger than approx.1.6 Earth radii.

Premature Mobility of Boulders in Constructed Step-pool River Structures in the Carmel River, CA: The Role of Fish-centric Design Constraints, and Flow on Structural Stability

NASA Astrophysics Data System (ADS)

Smith, D. P.; Chow, K.; Luna, L.

2017-12-01

The 32 m tall San Clemente Dam (Carmel River, CA) was removed in 2015 to eliminate seismic risk and to improve fish passage for all life stages of steelhead (O. mykiss). Reservoir sediment was sequestered in place, rather than released, and a new 1000 m long channel/floodplain system was constructed to circumvent the stored sediment. The channel comprised a 250 m long, meandering low-gradient reach and a 750 m reach with alternating step-pool sections, plane beds, and resting pools. The floodprone surfaces were compacted, wrapped in geotechnical fabric and vegetated. This study analyzes the geomorphic evolution of the new channel system during its first two years of service based upon detailed field inspection, SfM photogrammetry, orthophoto analysis, and 2d hydraulic modeling. A significant proportion of the step-pool structures experienced premature mobility and several reaches of engineered stream banks were eroded in the first year. Individual, six-tonne boulders were mobilized despite experiencing less than the 3 yr flow. The channel and floodplain were fully repaired following the first year. Strong flows (two 10-yr floods and a 30-yr flood) during the second year catastrophically altered the constructed channel and floodplain. While the low-gradient reach remained intact, each of the original step-pool structures was either completely mobilized and destroyed, buried by gravel, or bypassed by the subsequent channel. Despite the overall structural failure of the constructed channel, the new channel does not block steelhead migration, and can be serendipitously considered an ecological success. Step-pool design was constrained by a fish-centric requirement that steps be 1 ft tall or less. Some constructed "resting pools" filled rather than transport sediment. Using fish-centric constraints in the design, rather than strictly fluvial geomorphic principles may have contributed to early failure of the step-pool structures and other parts of the system.

Limits to Creation of Oxygen-Rich Atmospheres on Planets in the Outer Reaches of the Conventional Habitable Zone

NASA Astrophysics Data System (ADS)

Zahnle, Kevin

2017-10-01

Abundant free oxygen appears to be a requirement for macroflora and macrofauna. To the best of our knowledge, a general discussion of which habitable planets are conducive to oxygen has not taken place. Theories for the rise of oxygen fall into 4 categories: (i) It is governed by an intrinsic rate of biological innovation, independent of environmental factors. (ii) It is caused by mantle evolution, probably consequent to secular cooling. (iii) It is caused by hydrogen escape, which irreversibly oxidizes the Earth. (iv) It is Gaia’s response to the brightening Sun, its rise prevented until reduced greenhouse gases were no longer needed to maintain a clement climate. All but the first of these make implicit astronomical predictions that can be quantified and made explicit.Here we address the third hypothesis. In this hypothesis hydrogen escape acts like an hourglass that continues until all relevant reduced mineral buffers have been oxidized (titrated, as it were) and the surface made safe for O2. The hypothesis predicts that abundant free O2 will be absent from habitable planets that have not experienced significant hydrogen escape. Where hydrogen escape is modest or insignificant, the atmosphere can be approximated as hydrostatic, which makes assessing radiative cooling by embedded molecules, atoms, and ions such as CO2 and H3+ straightforward. In particular, H2 is efficient at exciting non-LTE CO2 15 micron emission, which makes radiative cooling very effective when H2 is abundant. We can therefore map out the region of phase space in which habitable planets do not lose hydrogen, and therefore do not develop O2 atmospheres.A related matter is the power of radiative cooling by embedded molecules to enforce the diffusion limit to hydrogen escape. This matter in particular is relevant to addressing the empirical observation that rocky planets with thin or negligible atmospheres are rarely or never bigger than ~1.6 Earth radii.

Effect of two-step and one-step surface conditioning of glass ceramic on adhesion strength of orthodontic bracket and effect of thermo-cycling on adhesion strength.

PubMed

Asiry, Moshabab A; AlShahrani, Ibrahim; Alaqeel, Samer M; Durgesh, Bangalore H; Ramakrishnaiah, Ravikumar

2018-08-01

The adhesion strength of orthodontic brackets bonded to dental glass ceramics was evaluated after ceramic surface was treated with two-step and one-step surface conditioning systems, and subjecting to thermo-cycling. A total of forty specimens were fabricated from silica based glass ceramic (lithium disilicate) by duplicating the buccal surface of maxillary first premolar. The specimens were randomly assigned to two experimental groups (n = 20), group one specimens were treated with two-step surface conditioning system (IPS ceramic etching gel™ and Monobond plus™) and group two specimens were treated with one-step surface conditioning system (Monobond etch and prime™). The surface roughness of the specimens after treatment with two-step and one-step surface conditioning system was measured using non-contact surface profilometer. Ten randomly selected specimens from each group were subjected to thermo-cycling and the remaining ten served as baseline. The shear bond strength of the specimens was measured using universal material testing machine. The adhesive remnant index score was calculated, and the results of surface roughness and bond strength were tabulated and subjected to analysis of variance and post hoc tukey's test at a significance level of p < 0.05. The results of the study showed that the specimens treated with two-step conditioning system had higher surface roughness and bond strength than one-step conditioning system. The majority of the specimens treated with both two-step and one-step conditioned specimens showed adhesive failure after subjecting thermo-cycling. Traditional two-step conditioning provides better bond strength. The clinical importance of the study is that, the silane promoted adhesion significantly reduces on exposure to thermo-cycling. Copyright © 2018 Elsevier Ltd. All rights reserved.

Surface runoff and soil erosion by difference of surface cover characteristics using by an oscillating rainfall simulator

NASA Astrophysics Data System (ADS)

Kim, J. K.; Kim, M. S.; Yang, D. Y.

2017-12-01

Sediment transfer within hill slope can be changed by the hydrologic characteristics of surface material on hill slope. To better understand sediment transfer of the past and future related to climate changes, studies for the changes of soil erosion due to hydrological characteristics changes by surface materials on hill slope are needed. To do so, on-situ rainfall simulating test was conducted on three different surface conditions, i.e. well covered with litter layer condition (a), undisturbed bare condition (b), and disturbed bare condition (c) and these results from rainfall simulating test were compared with that estimated using the Limburg Soil Erosion Model (LISEM). The result from the rainfall simulating tests showed differences in the infiltration rate (a > b > c) and the highest soil erosion rate was occurred on c condition. The result from model also was similar to those from rainfall simulating tests, however, the difference from the value of soil erosion rate between two results was quite large on b and c conditions. These results implied that the difference of surface conditions could change the surface runoff and soil erosion and the result from the erosion model might significantly underestimate on bare surface conditions rather than that from rainfall simulating test.

Peak Wind Forecasts for the Launch-Critical Wind Towers on Kennedy Space Center/Cape Canaveral Air Force Station, Phase IV

NASA Technical Reports Server (NTRS)

Crawford, Winifred

2011-01-01

This final report describes the development of a peak wind forecast tool to assist forecasters in determining the probability of violating launch commit criteria (LCC) at Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The peak winds arc an important forecast clement for both the Space Shuttle and Expendable Launch Vehicle (ELV) programs. The LCC define specific peak wind thresholds for each launch operation that cannot be exceeded in order to ensure the safety of the vehicle. The 45th Weather Squadron (45 WS) has found that peak winds are a challenging parameter to forecast, particularly in the cool season months of October through April. Based on the importance of forecasting peak winds, the 45 WS tasked the Applied Meteorology Unit (AMU) to update the statistics in the current peak-wind forecast tool to assist in forecasting LCC violations. The tool includes onshore and offshore flow climatologies of the 5-minute mean and peak winds and probability distributions of the peak winds as a function of the 5-minute mean wind speeds.

Preliminary Image Map of the 2007 Ammo Fire Perimeter, San Clemente Quadrangle, Orange and San Diego Counties, California

USGS Publications Warehouse

Clark, Perry S.; Scratch, Wendy S.; Bias, Gaylord W.; Stander, Gregory B.; Sexton, Jenne L.; Krawczak, Bridgette J.

2008-01-01

In the fall of 2007, wildfires burned out of control in southern California. The extent of these fires encompassed large geographic areas that included a variety of landscapes from urban to wilderness. The U.S. Geological Survey National Geospatial Technical Operations Center (NGTOC) is currently (2008) developing a quadrangle-based 1:24,000-scale image map product. One of the concepts behind the image map product is to provide an updated map in electronic format to assist with emergency response. This image map is one of 55 preliminary image map quadrangles covering the areas burned by the southern California wildfires. Each map is a layered, geo-registered Portable Document Format (.pdf) file. For more information about the layered geo-registered .pdf, see the readme file (http://pubs.usgs.gov/of/2008/1029/downloads/CA_Agua_Dulce_of2008-1029_README.txt). To view the areas affected and the quadrangles mapped in this preliminary project, see the map index (http://pubs.usgs.gov/of/2008/1029/downloads/CA_of2008_1029-1083_index.pdf) provided with this report.

Permittivity of naphthenic acid-water mixture.

PubMed

Mishra, Sabyasachi; Meda, Venkatesh; Dalai, Ajay

2007-01-01

Naphthenic acid (NA) is predominantly a mono-carboxylic acid obtained as a by-product of petroleum refining with variable composition and ingredients. It is reported that water affected by processes in the petroleum industries generally contains 40-120 mg IL of naphthenic acid which is considered to be in the range of toxicity to human consumption [Clemente et. al, 2005; McMartin, 2003]. This contaminated water needs treatment before its use as drinking water by remote communities. Recent literature suggests that NAs could be separated from diesel fuel using microwave radiation [Lingzhao et. al, 2004]. Removal of naphthenic acid from vacuum cut #1 distillate oil of Daqing using microwaves has also been reported by Huang et. al [2006]. The microwave treatment can be applied to drinking water containing small concentrations of naphthenic acid. In this case permittivity information is useful in designing a microwave applicator and modeling studies. Permittivity measurements were done using a HP 8510 Vector Network Analyzer and coaxial probe reflection method to study the dielectric properties of naphthenic acid in water. The effects of process variables such as frequency, concentration and temperature on dielectric properties were determined.

From promise to practice: getting healthy work environments in health workplaces.

PubMed

Silas, Linda

2007-01-01

The papers by Shamian and El-Jardali, "Healthy Workplaces for Health Workers in Canada," and by Clements, Dault and Priest, "Effective Teamwork in Healthcare," examine what makes the health workplace healthier, one from the perspective of workers and the other from the perspective of patients. Patients demand effective teamwork. Workers demand a range of initiatives, from occupational health and safety to professional development opportunities. Whereas patients' and workers' perspectives on healthy workplaces appear quite discrete as discussed in these papers, they are two sides of the same coin. Both lead papers recognize that unhealthy work environments result in unhealthy workers and reduced health outcomes for patients. Both review research documenting effective change and some progress in acceptance of proposed solutions at the policy level. Most importantly, both call for a greater effort in making these changes a reality in Canadian health workplaces. The papers themselves offer up some strategies for getting from yes to real. This commentary focuses on these and other strategies for moving forward and getting real change in the workplace, changes that workers and patients will talk about.

Discharge lamp with reflective jacket

DOEpatents

MacLennan, Donald A.; Turner, Brian P.; Kipling, Kent

2001-01-01

A discharge lamp includes an envelope, a fill which emits light when excited disposed in the envelope, a source of excitation power coupled to the fill to excite the fill and cause the fill to emit light, and a reflector disposed around the envelope and defining an opening, the reflector being configured to reflect some of the light emitted by the fill back into the fill while allowing some light to exit through the opening. The reflector may be made from a material having a similar thermal index of expansion as compared to the envelope and which is closely spaced to the envelope. The envelope material may be quartz and the reflector material may be either silica or alumina. The reflector may be formed as a jacket having a rigid structure which does not adhere to the envelope. The lamp may further include an optical clement spaced from the envelope and configured to reflect an unwanted component of light which exited the envelope back into the envelope through the opening in the reflector. Light which can be beneficially recaptured includes selected wavelength regions, a selected polarization, and selected angular components.

Comparative habitability of the Earth, Venus and Mars in the young solar system.

NASA Astrophysics Data System (ADS)

Nisbet, E. G.

2008-09-01

Abstract To be habitable, a planet must be suitable at all scales [1]. The setting in relation to the star must be right, so that surface temperatures can sustain liquid water. The planetary inventory must be suitable, providing surface water, rocks, and accessible thermodynamic disequilibrium. There must be physical habitat, especially mud and hydrothermal systems around volcanoes. Planets are not static: they evolve. Habitability must evolve with the planet. On accretion, the processes of impact and formation of volatile inventory must be suitable. Tectonics and volcanism must supply redox contrasts and biochemical substrates capable not only of starting life but of sustaining it. Mud or soft sediment may be essential: it is unlikely that early life can sustain itself in open water or air. This requirement for mud has tectonic implications. Once life starts, it immediately alters its own environment, by consuming nutrient. Until photosynthesis evolves, inorganic sources must supply sustained redox contrast to the local environment. But life changes its setting, both by risky alterations to the atmospheric greenhouse (drawing down CO2, emitting CH4), and by partitioning reductants (e.g. as dead bodies) and oxidants (waste). Somehow the planet must avoid both freezing and boiling. Early in the history of the solar system, a passing galactic tourist might have rated Venus as the likeliest habitat for life, Mars next, and Earth last of the three. Venus was warm and hospitable, Mars clement, and Earth had been though an impact episode powerful enough to make a silicate atmosphere. By comparison with Earth there are many potential environmental settings on Mars in which life may once have occurred, or may even continue to exist. Perhaps Mars seeded earth? Yet today the reverse order of habitability is the case. Earth today is safeguarded by a reworked atmosphere that is 99% of biological construction, maintained in active disequilibrium with the surface. Mars, in contrast, is chilly oxidised permafrost where kinetics alone would make life difficult. Venus has achieved sustainable equilibrium, where equilibrium, being the opposite of life, equals death. Geologically, how and why did this happen? Earth was not necessarily the Goldilocks planet, neither too warm not too cold. But it did have a degree of locally-accessible disequilibrium, to sustain early life. Life itself, especially the enzyme rubisco, that mediates carbon transfer from air to organism, then actively managed to rework the surface of Earth. From the moment life began, it remade its house to maintain habitability. Life, if ever present on Mars, may have simply died from lack of resources. Any life on Venus would have died of dehydration or by being cooked. However, terraforming may now be worth attempting on both planets: as on Earth it may be self-sustaining, even after the terraforming species becomes extinct. [1] Nisbet, E.G. Zahnle, K., Gersimov, M., Helbert, J., Jaumann, R., Hofmann, B., Benzerara, K, Westall, F., Spc. Sci. Rev. (2007), 129, 79-121.

Report for borehole explosion data acquired in the 1999 Los Angeles Region Seismic Experiment (LARSE II), Southern California: Part I, description of the survey

USGS Publications Warehouse

Fuis, Gary S.; Murphy, Janice M.; Okaya, David A.; Clayton, Robert W.; Davis, Paul M.; Thygesen, Kristina; Baher, Shirley A.; Ryberg, Trond; Benthien, Mark L.; Simila, Gerry; Perron, J. Taylor; Yong, Alan K.; Reusser, Luke; Lutter, William J.; Kaip, Galen; Fort, Michael D.; Asudeh, Isa; Sell, Russell; Van Schaack, John R.; Criley, Edward E.; Kaderabek, Ronald; Kohler, Will M.; Magnuski, Nickolas H.

2001-01-01

The Los Angeles Region Seismic Experiment (LARSE) is a joint project of the U.S. Geological Survey (USGS) and the Southern California Earthquake Center (SCEC). The purpose of this project is to produce seismic images of the subsurface of the Los Angeles region down to the depths at which earthquakes occur, and deeper, in order to remedy a deficit in our knowledge of the deep structure of this region. This deficit in knowledge has persisted despite over a century of oil exploration and nearly 70 years of recording earthquakes in southern California. Understanding the deep crustal structure and tectonics of southern California is important to earthquake hazard assessment. Specific imaging targets of LARSE include (a) faults, especially blind thrust faults, which cannot be reliably detected any other way; and (b) the depths and configurations of sedimentary basins. Imaging of faults is important in both earthquake hazard assessment but also in modeling earthquake occurrence. Earthquake occurrence cannot be understood unless the earthquake-producing "machinery" (tectonics) is known (Fuis and others, 2001). Imaging the depths and configurations of sedimentary basins is important because earthquake shaking at the surface is enhanced by basin depth and by the presence of sharp basin edges (Wald and Graves, 1998, Working Group on California Earthquake Probabilities, 1995; Field and others, 2001). (Sedimentary basins are large former valleys now filled with sediment eroded from nearby mountains.) Sedimentary basins in the Los Angeles region that have been investigated by LARSE include the Los Angeles, San Gabriel Valley, San Fernando Valley, and Santa Clarita Valley basins. The seismic imaging surveys of LARSE include recording of earthquakes (both local and distant earthquakes) along several corridors (or transects) through the Los Angeles region and also recording of man-made sources along these same corridors. Man-made sources have included airguns offshore and borehole explosions and vibrating-truck sources onshore. The two chief LARSE transects pass near recent moderate earthquakes, including the 1971 M 6.7 San Fernando, 1987 M 5.9 Whittier Narrows, 1991 M 5.8 Sierra Madre, and 1994 M 6.7 Northridge earthquakes. The first transect extended from San Clemente Island northeastward to the Mojave Desert (Line 1, Fig. 1), passing near the epicenter of the Whittier Narrows and Sierra Madre earthquakes. The second transect extended from west of San Clemente Island northward to the western Mojave Desert (Line 2, Figs. 1, 2), passing through the epicenter of the Northridge earthquake and near the epicenter of the San Fernando earthquake. Data along Line 1 were acquired during the years 1993-1994, and data along Line 2, during the years 1994–2000. In this open-file report and that of Murphy and others (in preparation), we present the details of the October 1999 explosion survey along Line 2, which extended from Santa Monica Bay northward to the western Mojave Desert (Figs. 1, 2). This survey is referred to as LARSE II. In this survey, 93 borehole explosions were detonated along the main north-south line and along 5 auxiliary lines in the San Fernando Valley and Santa Monica areas. These explosions were recorded by ~1400 seismographs. A variety of seismic instrumentation was used in these imaging surveys and was obtained from collaborators from around the world, including the Geological Survey of Canada (Ottawa, Canada), IRIS/PASSCAL (Socorro, NM), Lamont-Doherty Earth Observatory (Palisades, NY), Stanford University (Stanford, CA), SCEC (Los Angeles, CA), USGS (Menlo Park, CA, and Woods Hole, MA), University of Texas at El Paso (El Paso, TX), GeoForschungsZentrum (Potsdam, Germany), University of Karlsruhe (Karlsruhe, Germany), and University of Copenhagen (Copenhagen, Denmark). The reader is referred to Table 1 for instrumentation used in LARSE II.

Effect of processing history on the surface interfacial properties of budesonide in carrier-based dry-powder inhalers.

PubMed

Shur, Jagdeep; Pitchayajittipong, Chonladda; Rogueda, Philippe; Price, Robert

2013-08-01

Influence of air-jet micronization, post-micronization conditioning and storage on the surface properties of budesonide in dry-powder inhaler formulations was investigated. Crystalline budesonide was air jet-micronized and conditioned using organic vapor. Particle engineering was also used to fabricate respirable particles of budesonide. Surface imaging by atomic force microscopy suggested that micronized material possessed process-induced surface disorder, which relaxed upon conditioning with organic vapor. Particle engineered material was devoid of such surface disorder. Surface interfacial properties of all batches were different and correlated to in vitro fine particle delivery. The surface properties and in vitro performance of the conditioned material changed upon storage of the budesonide at 44% relative humidity and 25°C, while the micronized and particle-engineered material remained stable. These data suggest that processing conditions of budesonide affected the surface properties of the material, which was demonstrated to have direct affect on dry-powder inhaler formulation performance.

Boundary Conditions for Scalar (Co)Variances over Heterogeneous Surfaces

NASA Astrophysics Data System (ADS)

Machulskaya, Ekaterina; Mironov, Dmitrii

2018-05-01

The problem of boundary conditions for the variances and covariances of scalar quantities (e.g., temperature and humidity) at the underlying surface is considered. If the surface is treated as horizontally homogeneous, Monin-Obukhov similarity suggests the Neumann boundary conditions that set the surface fluxes of scalar variances and covariances to zero. Over heterogeneous surfaces, these boundary conditions are not a viable choice since the spatial variability of various surface and soil characteristics, such as the ground fluxes of heat and moisture and the surface radiation balance, is not accounted for. Boundary conditions are developed that are consistent with the tile approach used to compute scalar (and momentum) fluxes over heterogeneous surfaces. To this end, the third-order transport terms (fluxes of variances) are examined analytically using a triple decomposition of fluctuating velocity and scalars into the grid-box mean, the fluctuation of tile-mean quantity about the grid-box mean, and the sub-tile fluctuation. The effect of the proposed boundary conditions on mixing in an archetypical stably-stratified boundary layer is illustrated with a single-column numerical experiment. The proposed boundary conditions should be applied in atmospheric models that utilize turbulence parametrization schemes with transport equations for scalar variances and covariances including the third-order turbulent transport (diffusion) terms.

Improving Weather Research and Forecasting Model Initial Conditions via Surface Pressure Analysis

DTIC Science & Technology

2015-09-01

Obsgrid) that creates input data for the Advanced Research version of the Weather Research and Forecasting model ( WRF -ARW) is modified to perform a...surface pressure objective analysis to allow surface analyses of other fields to be more fully utilized in the WRF -ARW initial conditions. Nested 27-, 9...of surface pressure unnecessarily limits the application of other surface analyses into the WRF initial conditions and contributes to the creation of

Acid base properties of cyanobacterial surfaces I: Influences of growth phase and nitrogen metabolism on cell surface reactivity

NASA Astrophysics Data System (ADS)

Lalonde, S. V.; Smith, D. S.; Owttrim, G. W.; Konhauser, K. O.

2008-03-01

Significant efforts have been made to elucidate the chemical properties of bacterial surfaces for the purposes of refining surface complexation models that can account for their metal sorptive behavior under diverse conditions. However, the influence of culturing conditions on surface chemical parameters that are modeled from the potentiometric titration of bacterial surfaces has received little regard. While culture age and metabolic pathway have been considered as factors potentially influencing cell surface reactivity, statistical treatments have been incomplete and variability has remained unconfirmed. In this study, we employ potentiometric titrations to evaluate variations in bacterial surface ligand distributions using live cells of the sheathless cyanobacterium Anabaena sp. strain PCC 7120, grown under a variety of batch culture conditions. We evaluate the ability for a single set of modeled parameters, describing acid-base surface properties averaged over all culture conditions tested, to accurately account for the ligand distributions modeled for each individual culture condition. In addition to considering growth phase, we assess the role of the various assimilatory nitrogen metabolisms available to this organism as potential determinants of surface reactivity. We observe statistically significant variability in site distribution between the majority of conditions assessed. By employing post hoc Tukey-Kramer analysis for all possible pair-wise condition comparisons, we conclude that the average parameters are inadequate for the accurate chemical description of this cyanobacterial surface. It was determined that for this Gram-negative bacterium in batch culture, ligand distributions were influenced to a greater extent by nitrogen assimilation pathway than by growth phase.

The dynamic failure behavior of tungsten heavy alloys subjected to transverse loads

NASA Astrophysics Data System (ADS)

Tarcza, Kenneth Robert

Tungsten heavy alloys (WHA), a category of particulate composites used in defense applications as kinetic energy penetrators, have been studied for many years. Even so, their dynamic failure behavior is not fully understood and cannot be predicted by numerical models presently in use. In this experimental investigation, a comprehensive understanding of the high-rate transverse-loading fracture behavior of WHA has been developed. Dynamic fracture events spanning a range of strain rates and loading conditions were created via mechanical testing and used to determine the influence of surface condition and microstructure on damage initiation, accumulation, and sample failure under different loading conditions. Using standard scanning electron microscopy metallographic and fractographic techniques, sample surface condition is shown to be extremely influential to the manner in which WHA fails, causing a fundamental change from externally to internally nucleated failures as surface condition is improved. Surface condition is characterized using electron microscopy and surface profilometry. Fracture surface analysis is conducted using electron microscopy, and linear elastic fracture mechanics is used to understand the influence of surface condition, specifically initial flaw size, on sample failure behavior. Loading conditions leading to failure are deduced from numerical modeling and experimental observation. The results highlight parameters and considerations critical to the understanding of dynamic WHA fracture and the development of dynamic WHA failure models.

Assessment of roadway surface conditions using onboard vehicle sensors : final report phase I.

DOT National Transportation Integrated Search

2015-03-01

Real-time assessment of road surface conditions can be used to provide valuable safety information to travelers when roads are slippery (e.g., contaminated roads, heavy rain, black ice, etc.). Identification of these hazardous surface conditions usin...

How Well Can Infrared Sounders Observe the Atmosphere and Surface Through Clouds?

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Strow, L. Larrabee; Yang, Ping

2010-01-01

Infrared sounders, such as the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared sounder (CrIS), have a cloud-impenetrable disadvantage in observing the atmosphere and surface under opaque cloudy conditions. However, recent studies indicate that hyperspectral, infrared sounders have the ability to detect cloud effective-optical and microphysical properties and to penetrate optically thin clouds in observing the atmosphere and surface to a certain degree. We have developed a retrieval scheme dealing with atmospheric conditions with cloud presence. This scheme can be used to analyze the retrieval accuracy of atmospheric and surface parameters under clear and cloudy conditions. In this paper, we present the surface emissivity results derived from IASI global measurements under both clear and cloudy conditions. The accuracy of surface emissivity derived under cloudy conditions is statistically estimated in comparison with those derived under clear sky conditions. The retrieval error caused by the clouds is shown as a function of cloud optical depth, which helps us to understand how well infrared sounders can observe the atmosphere and surface through clouds.

Validation of the Earthquake Archaeological Effects methodology by studying the San Clemente cemetery damages generated during the Lorca earthquake of 2011

NASA Astrophysics Data System (ADS)

Martín-González, Fidel; Martín-Velazquez, Silvia; Rodrigez-Pascua, Miguel Angel; Pérez-López, Raul; Silva, Pablo

2014-05-01

The intensity scales determined the damage caused by an earthquake. However, a new methodology takes into account not only the damage but the type of damage "Earthquake Archaeological Effects", EAE's, and its orientation (e.g. displaced masonry blocks, conjugated fractures, fallen and oriented columns, impact marks, dipping broken corners, etc.) (Rodriguez-Pascua et al., 2011; Giner-Robles et al., 2012). Its main contribution is that it focuses not only on the amount of damage but also in its orientation, giving information about the ground motion during the earthquake. Therefore, this orientations and instrumental data can be correlated with historical earthquakes. In 2011 an earthquake of magnitude Mw 5.2 took place in Lorca (SE Spain) (9 casualties and 460 million Euros in reparations). The study of the EAE's was carried out through the whole city (Giner-Robles et al., 2012). The present study aimed to a.- validate the EAE's methodology using it only in a small place, specifically the cemetery of San Clemente in Lorca, and b.- constraining the range of orientation for each EAE's. This cemetery has been selected because these damage orientation data can be correlated with instrumental information available, and also because this place has: a.- wide variety of architectural styles (neogothic, neobaroque, neoarabian), b.- its Cultural Interest (BIC), and c.- different building materials (brick, limestone, marble). The procedure involved two main phases: a.- inventory and identification of damage (EAE's) by pictures, and b.- analysis of the damage orientations. The orientation was calculated for each EAE's and plotted in maps. Results are NW-SE damage orientation. This orientation is consistent with that recorded in the accelerometer of Lorca (N160°E) and with that obtained from the analysis of EAE's for the whole town of Lorca (N130°E) (Giner-Robles et al., 2012). Due to the existence of an accelerometer, we know the orientation of the peak ground acceleration and we have been able to constrain the ranges of orientation for each EAE's. The orientation of the damage is not usually recorded after an earthquake; however, it can provide information on seismic source in historical earthquakes. References Giner-Robles, J. L., Perez-Lopez, R., Silva Barroso, P., Rodriguez-Pascua, M. A., Martin-Gonzalez, F. and Cabanas, L. 2012. Analisis estructural de danos orientados en el terremoto de Lorca del 11 de mayo de 2011. Aplicaciones en arqueosismologia. Boletín Geológico y Minero, 123 (4): 503-513 Rodriguez-Pascua, M.A., Perez-Lopez, R., Silva, P.G., Giner- Robles, J.L., Garduno-Monroy, V.H. and Reicherter, K. 2011. A Comprehensive Classification of Earthquake Archaeological Effects (EAE) for Archaeoseismology. Quaternary International, 242, 20-30.

Evaluation of new in vitro efficacy test for antimicrobial surface activity reflecting UK hospital conditions.

PubMed

Ojeil, M; Jermann, C; Holah, J; Denyer, S P; Maillard, J-Y

2013-12-01

Antimicrobial surfaces aim to reduce microbial bioburden and improve hygiene. The current antimicrobial surface efficacy test (ISO22196) is an initial screening test but its conditions, high temperature (37°C) and relative humidity (RH) (100%) bear little relationship to in-use conditions. To develop an antimicrobial surface efficacy test providing a realistic second-tier test, simulating in-use conditions. Surface relative humidity, temperature and soiling were measured over one year at a UK hospital, enabling realistic parameters to be set for our surface efficacy test. A nebulizer, connected to a cascade impactor, aerosolized and uniformly deposited a Staphylococcus aureus suspension over test copper alloys and control stainless steel surfaces. Bacteria were enumerated following nebulization, and after a range of contact times, under [20°C, 50% RH] and [20°C, 40% RH] parameters reflecting in-use conditions; [37°C, 100% RH] was employed to reflect conditions used in ISO22196. All copper alloys produced a >4 log10 reduction after 24h under all conditions tested. Copper alloys were more effective at [37°C, 100% RH] showing a >4 log10 reduction after 30 min than at in-use conditions [20°C, 50% RH and 20°C, 40% RH], for which 60 min was required to achieve the same level of kill, for most but not all alloys. The use of the nebulizer to deposit bacterial inocula on surfaces showed little variability in results. Our method was more discriminatory than the ISO22196 enabling distinction between the bactericidal surface activity, which allows for a more rigorous selection of antimicrobial surfaces for potential use in healthcare settings. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Carbon dioxide and methane measurements from the Los Angeles Megacity Carbon Project - Part 1: calibration, urban enhancements, and uncertainty estimates

NASA Astrophysics Data System (ADS)

Verhulst, Kristal R.; Karion, Anna; Kim, Jooil; Salameh, Peter K.; Keeling, Ralph F.; Newman, Sally; Miller, John; Sloop, Christopher; Pongetti, Thomas; Rao, Preeti; Wong, Clare; Hopkins, Francesca M.; Yadav, Vineet; Weiss, Ray F.; Duren, Riley M.; Miller, Charles E.

2017-07-01

We report continuous surface observations of carbon dioxide (CO2) and methane (CH4) from the Los Angeles (LA) Megacity Carbon Project during 2015. We devised a calibration strategy, methods for selection of background air masses, calculation of urban enhancements, and a detailed algorithm for estimating uncertainties in urban-scale CO2 and CH4 measurements. These methods are essential for understanding carbon fluxes from the LA megacity and other complex urban environments globally. We estimate background mole fractions entering LA using observations from four extra-urban sites including two marine sites located south of LA in La Jolla (LJO) and offshore on San Clemente Island (SCI), one continental site located in Victorville (VIC), in the high desert northeast of LA, and one continental/mid-troposphere site located on Mount Wilson (MWO) in the San Gabriel Mountains. We find that a local marine background can be established to within ˜ 1 ppm CO2 and ˜ 10 ppb CH4 using these local measurement sites. Overall, atmospheric carbon dioxide and methane levels are highly variable across Los Angeles. Urban and suburban sites show moderate to large CO2 and CH4 enhancements relative to a marine background estimate. The USC (University of Southern California) site near downtown LA exhibits median hourly enhancements of ˜ 20 ppm CO2 and ˜ 150 ppb CH4 during 2015 as well as ˜ 15 ppm CO2 and ˜ 80 ppb CH4 during mid-afternoon hours (12:00-16:00 LT, local time), which is the typical period of focus for flux inversions. The estimated measurement uncertainty is typically better than 0.1 ppm CO2 and 1 ppb CH4 based on the repeated standard gas measurements from the LA sites during the last 2 years, similar to Andrews et al. (2014). The largest component of the measurement uncertainty is due to the single-point calibration method; however, the uncertainty in the background mole fraction is much larger than the measurement uncertainty. The background uncertainty for the marine background estimate is ˜ 10 and ˜ 15 % of the median mid-afternoon enhancement near downtown LA for CO2 and CH4, respectively. Overall, analytical and background uncertainties are small relative to the local CO2 and CH4 enhancements; however, our results suggest that reducing the uncertainty to less than 5 % of the median mid-afternoon enhancement will require detailed assessment of the impact of meteorology on background conditions.

Finite difference time domain implementation of surface impedance boundary conditions

NASA Technical Reports Server (NTRS)

Beggs, John H.; Luebbers, Raymond J.; Yee, Kane S.; Kunz, Karl S.

1991-01-01

Surface impedance boundary conditions are employed to reduce the solution volume during the analysis of scattering from lossy dielectric objects. In the finite difference solution, they also can be utilized to avoid using small cells, made necessary by shorter wavelengths in conducting media throughout the solution volume. The standard approach is to approximate the surface impedance over a very small bandwidth by its value at the center frequency, and then use that result in the boundary condition. Here, two implementations of the surface impedance boundary condition are presented. One implementation is a constant surface impedance boundary condition and the other is a dispersive surface impedance boundary condition that is applicable over a very large frequency bandwidth and over a large range of conductivities. Frequency domain results are presented in one dimension for two conductivity values and are compared with exact results. Scattering width results from an infinite square cylinder are presented as a two dimensional demonstration. Extensions to three dimensions should be straightforward.

Finite difference time domain implementation of surface impedance boundary conditions

NASA Technical Reports Server (NTRS)

Beggs, John H.; Luebbers, Raymond J.; Yee, Kane S.; Kunz, Karl S.

1991-01-01

Surface impedance boundary conditions are employed to reduce the solution volume during the analysis of scattering from lossy dielectric objects. In a finite difference solution, they also can be utilized to avoid using small cells, made necessary by shorter wavelengths in conducting media throughout the solution volume. The standard approach is to approximate the surface impedance over a very small bandwidth by its value at the center frequency, and then use that result in the boundary condition. Two implementations of the surface impedance boundary condition are presented. One implementation is a constant surface impedance boundary condition and the other is a dispersive surface impedance boundary condition that is applicable over a very large frequency bandwidth and over a large range of conductivities. Frequency domain results are presented in one dimension for two conductivity values and are compared with exact results. Scattering width results from an infinite square cylinder are presented as a 2-D demonstration. Extensions to 3-D should be straightforward.

The Point of Departure of a Particle Sliding on a Curved Surface

ERIC Educational Resources Information Center

Aghamohammadi, Amir

2012-01-01

A particle is thrown tangentially on a surface. It is shown that for some surfaces and for special initial velocities the thrown particle immediately leaves the surface, and for special conditions it never leaves the surface. The conditions for leaving the surface are investigated. The problem is studied for a surface with the cross-section y =…

Assimilation and High Resolution Forecasts of Surface and Near Surface Conditions for the 2010 Vancouver Winter Olympic and Paralympic Games

NASA Astrophysics Data System (ADS)

Bernier, Natacha B.; Bélair, Stéphane; Bilodeau, Bernard; Tong, Linying

2014-01-01

A dynamical model was experimentally implemented to provide high resolution forecasts at points of interests in the 2010 Vancouver Olympics and Paralympics Region. In a first experiment, GEM-Surf, the near surface and land surface modeling system, is driven by operational atmospheric forecasts and used to refine the surface forecasts according to local surface conditions such as elevation and vegetation type. In this simple form, temperature and snow depth forecasts are improved mainly as a result of the better representation of real elevation. In a second experiment, screen level observations and operational atmospheric forecasts are blended to drive a continuous cycle of near surface and land surface hindcasts. Hindcasts of the previous day conditions are then regarded as today's optimized initial conditions. Hence, in this experiment, given observations are available, observation driven hindcasts continuously ensure that daily forecasts are issued from improved initial conditions. GEM-Surf forecasts obtained from improved short-range hindcasts produced using these better conditions result in improved snow depth forecasts. In a third experiment, assimilation of snow depth data is applied to further optimize GEM-Surf's initial conditions, in addition to the use of blended observations and forecasts for forcing. Results show that snow depth and summer temperature forecasts are further improved by the addition of snow depth data assimilation.

Computer program for calculating aerodynamic characteristics of upper-surface-blowing and over-wing-blowing configurations

NASA Technical Reports Server (NTRS)

Lan, C. E.; Fillman, G. L.; Fox, C. H., Jr.

1977-01-01

The program is based on the inviscid wing-jet interaction theory of Lan and Campbell, and the jet entrainment theory of Lan. In the interaction theory, the flow perturbations are computed both inside and outside the jet, separately, and then matched on the jet surface to satisfy the jet boundary conditions. The jet Mach number is allowed to be different from the free stream value (Mach number nonuniformity). These jet boundary conditions require that the static pressure be continuous across the jet surface which must always remain as a stream surface. These conditions, as well as the wing-surface tangency condition, are satisified only in the linearized sense. The detailed formulation of these boundary conditions is based on the quasi-vortex-lattice method of Lan.

Numerical simulation of diurnally varying thermal environment in a street canyon under haze-fog conditions

NASA Astrophysics Data System (ADS)

Tan, Zijing; Dong, Jingliang; Xiao, Yimin; Tu, Jiyuan

2015-10-01

The impact of haze-fog on surface temperature, flow pattern, pollutant dispersion and pedestrian thermal comfort are investigated using computational fluid dynamics (CFD) approach based on a three-dimensional street canyon model under different haze-fog conditions. In this study, light extinction coefficient (Kex) is adopted to represent haze-fog pollution level. Numerical simulations are performed for different Kex values at four representative time events (1000 LST, 1300 LST, 1600 LST and 2000 LST). The numerical results suggest that the surface temperature is strongly affected by the haze-fog condition. Surface heating induced by the solar radiation is enhanced by haze-fog, as higher surface temperature is observed under thicker haze-fog condition. Moreover, the temperature difference between sunlit and shadow surfaces is reduced, while that for the two shadow surfaces is slightly increased. Therefore, the surface temperature among street canyon facets becomes more evenly distributed under heavy haze-fog conditions. In addition, flow patterns are considerably altered by different haze-fog conditions, especially for the afternoon (1600 LST) case, in which thermal-driven flow has opposite direction as that of the wind-driven flow direction. Consequently, pollutants such as vehicular emissions will accumulate at pedestrian level, and pedestrian thermal comfort may lower under thicker haze-fog condition.

Using a hybrid model to predict solute transfer from initially saturated soil into surface runoff with controlled drainage water.

PubMed

Tong, Juxiu; Hu, Bill X; Yang, Jinzhong; Zhu, Yan

2016-06-01

The mixing layer theory is not suitable for predicting solute transfer from initially saturated soil to surface runoff water under controlled drainage conditions. By coupling the mixing layer theory model with the numerical model Hydrus-1D, a hybrid solute transfer model has been proposed to predict soil solute transfer from an initially saturated soil into surface water, under controlled drainage water conditions. The model can also consider the increasing ponding water conditions on soil surface before surface runoff. The data of solute concentration in surface runoff and drainage water from a sand experiment is used as the reference experiment. The parameters for the water flow and solute transfer model and mixing layer depth under controlled drainage water condition are identified. Based on these identified parameters, the model is applied to another initially saturated sand experiment with constant and time-increasing mixing layer depth after surface runoff, under the controlled drainage water condition with lower drainage height at the bottom. The simulation results agree well with the observed data. Study results suggest that the hybrid model can accurately simulate the solute transfer from initially saturated soil into surface runoff under controlled drainage water condition. And it has been found that the prediction with increasing mixing layer depth is better than that with the constant one in the experiment with lower drainage condition. Since lower drainage condition and deeper ponded water depth result in later runoff start time, more solute sources in the mixing layer are needed for the surface water, and larger change rate results in the increasing mixing layer depth.

Thermophysical Properties Measurement of High-Temperature Liquids Under Microgravity Conditions in Controlled Atmospheric Conditions

NASA Technical Reports Server (NTRS)

Watanabe, Masahito; Ozawa, Shumpei; Mizuno, Akotoshi; Hibiya, Taketoshi; Kawauchi, Hiroya; Murai, Kentaro; Takahashi, Suguru

2012-01-01

Microgravity conditions have advantages of measurement of surface tension and viscosity of metallic liquids by the oscillating drop method with an electromagnetic levitation (EML) device. Thus, we are preparing the experiments of thermophysical properties measurements using the Materials-Science Laboratories ElectroMagnetic-Levitator (MSL-EML) facilities in the international Space station (ISS). Recently, it has been identified that dependence of surface tension on oxygen partial pressure (Po2) must be considered for industrial application of surface tension values. Effect of Po2 on surface tension would apparently change viscosity from the damping oscillation model. Therefore, surface tension and viscosity must be measured simultaneously in the same atmospheric conditions. Moreover, effect of the electromagnetic force (EMF) on the surface oscillations must be clarified to obtain the ideal surface oscillation because the EMF works as the external force on the oscillating liquid droplets, so extensive EMF makes apparently the viscosity values large. In our group, using the parabolic flight levitation experimental facilities (PFLEX) the effect of Po2 and external EMF on surface oscillation of levitated liquid droplets was systematically investigated for the precise measurements of surface tension and viscosity of high temperature liquids for future ISS experiments. We performed the observation of surface oscillations of levitated liquid alloys using PFLEX on board flight experiments by Gulfstream II (G-II) airplane operated by DAS. These observations were performed under the controlled Po2 and also under the suitable EMF conditions. In these experiments, we obtained the density, the viscosity and the surface tension values of liquid Cu. From these results, we discuss about as same as reported data, and also obtained the difference of surface oscillations with the change of the EMF conditions.

Ebola Virus Stability on Surfaces and in Fluids in Simulated Outbreak Environments.

PubMed

Fischer, Robert; Judson, Seth; Miazgowicz, Kerri; Bushmaker, Trenton; Prescott, Joseph; Munster, Vincent J

2015-07-01

We evaluated the stability of Ebola virus on surfaces and in fluids under simulated environmental conditions for the climate of West Africa and for climate-controlled hospitals. This virus remains viable for a longer duration on surfaces in hospital conditions than in African conditions and in liquid than in dried blood.

INVESTIGATING SURFACE WATER QUALITY IMPACTS ON GROUNDWATER QUALITY UNDER VARYING FLOW CONDITIONS IN THE BARTON SPRINGS SEGMENT OF THE EDWARDS AQUIFER, CENTRAL TEXAS

EPA Science Inventory

The expected results from this research include: i) the quantification of the proportion of surface water comprising spring discharge under varying flow conditions; ii) the characterization of surface watersheds under varying antecedent moisture conditions, and evaluation of ...

Spatially-varied erosion modeling using WEPP for timber harvested and burned hillslopes

Treesearch

Peter R. Robichaud; T. M. Monroe

1997-01-01

Spatially-varied hydrologic surface conditions exist on steep hillslopes after timber harvest operation and site preparation burning treatments. Site preparation burning creates low- and high-severity burn surface conditions or disturbances. In this study, a hillslope was divided into multiple combinations of surface conditions to determine how their spatial...

Evaluation of two transport aircraft and several ground test vehicle friction measurements obtained for various runway surface types and conditions. A summary of test results from joint FAA/NASA Runway Friction Program

NASA Technical Reports Server (NTRS)

Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

1990-01-01

Tests with specially instrumented NASA Boeing 737 and 727 aircraft together with several different ground friction measuring devices were conducted for a variety of runway surface types and conditions. These tests are part of joint FAA/NASA Aircraft/Ground Vehicle Runway Friction Program aimed at obtaining a better understanding of aircraft ground handling performance under adverse weather conditions and defining relationships between aircraft and ground vehicle tire friction measurements. Aircraft braking performance on dry, wet, snow and ice-covered runway conditions is discussed as well as ground vehicle friction data obtained under similar runway conditions. For a given contaminated runway surface condition, the correlation between ground vehicles and aircraft friction data is identified. The influence of major test parameters on friction measurements such as speed, test tire characteristics, type and amount of surface contaminant, and ambient temperature are discussed. The effect of surface type on wet friction levels is also evaluated from comparative data collected on grooved and ungrooved concrete and asphalt surfaces.

Interaction of Strong Turbulence With Free Surfaces

NASA Astrophysics Data System (ADS)

Dalrymple, Robert A.

Spray from a nozzle, spilling breakers, and “rooster tails” from speeding boats are all examples of a turbulent flow with a free surface. In many cases like these, the free surface is difficult to discern as the volume of air in the fluid can exceed that of the water.In traditional studies, the free surface is simply defined as a continuous surface separating the fluid from air. The pressure at the surface is assumed to be atmospheric pressure and the fluid comprising the surface moves with the surface. While these conditions are sufficient for non-turbulent flows, such as nonbreaking water waves, and lead to the (albeit non-linear) dynamic and kinematic free surface boundary conditions that serve to provide sufficient conditions to determine the surface, they are not valid descriptions for a bubbly free surface in a highly turbulent regime, such as the roller in front of a spilling breaker or the propeller wash behind a ship.

Numerical study on influence of single control surface on aero elastic behavior of forward-swept wing

NASA Astrophysics Data System (ADS)

Wang, Ning; Su, Xinbing; Ma, Binlin; Zhang, Xiaofei

2017-10-01

In order to study the influence of elastic forward-swept wing (FSW) with single control surface, the computational fluid dynamics/computational structural dynamics (CFD/CSD) loose coupling static aero elastic numerical calculation method was adopted for numerical simulation. The effects of the elastic FSW with leading- or trailing-edge control surface on aero elastic characteristics were calculated and analysed under the condition of high subsonic speed. The result shows that, the deflection of every single control surface could change the aero elastic characteristics of elastic FSW greatly. Compared with the baseline model, when leading-edge control surface deflected up, under the condition of small angles of attack, the aerodynamic characteristics was poor, but the bending and torsional deformation decreased. Under the condition of moderate angles of attack, the aerodynamic characteristics was improved, but bending and torsional deformation increased; When leading-edge control surface deflected down, the aerodynamic characteristics was improved, the bending and torsional deformation decreased/increased under the condition of small/moderate angles of attack. Compared with the baseline model, when trailing-edge control surface deflected down, the aerodynamic characteristics was improved. The bending and torsional deformation increased under the condition of small angles of attack. The bending deformation increased under the condition of small angles of attack, but torsional deformation decreases under the condition of moderate angles of attack. So, for the elastic FSW, the deflection of trailing-edge control surface play a more important role on the improvement of aerodynamic and elastic deformation characteristics.

The effect of physiological conditions on the surface structure of proteins: Setting the scene for human digestion of emulsions

NASA Astrophysics Data System (ADS)

Maldonado-Valderrama, J.; Gunning, A. P.; Ridout, M. J.; Wilde, P. J.; Morris, V. J.

2009-10-01

Understanding and manipulating the interfacial mechanisms that control human digestion of food emulsions is a crucial step towards improved control of dietary intake. This article reports initial studies on the effects of the physiological conditions within the stomach on the properties of the film formed by the milk protein ( β -lactoglobulin) at the air-water interface. Atomic force microscopy (AFM), surface tension and surface rheology techniques were used to visualize and examine the effect of gastric conditions on the network structure. The effects of changes in temperature, pH and ionic strength on a pre-formed interfacial structure were characterized in order to simulate the actual digestion process. Changes in ionic strength had little effect on the surface properties. In isolation, acidification reduced both the dilatational and the surface shear modulus, mainly due to strong repulsive electrostatic interactions within the surface layer and raising the temperature to body temperature accelerated the rearrangements within the surface layer, resulting in a decrease of the dilatational response and an increase of surface pressure. Together pH and temperature display an unexpected synergism, independent of the ionic strength. Thus, exposure of a pre-formed interfacial β -lactoglobulin film to simulated gastric conditions reduced the surface dilatational modulus and surface shear moduli. This is attributed to a weakening of the surface network in which the surface rearrangements of the protein prior to exposure to gastric conditions might play a crucial role.

Air Force Academy Aeronautics Digest - Spring/Summer 1981.

DTIC Science & Technology

1981-12-01

real fluids with friction or viscosity we know that this boundary condition is specified by requiring the velocity to be zero at the surface). This is...interest to be zero . This is the velocity surface boundary condition (VBC). For the second boundary condition far away from the body it is reasonable to...remains unchanged). Finally, the analytic solution, in terms of the surface velocity distribution at a zero -lift condition, will be presented for selected

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

Meckel, Timothy; Trevino, Ramon

This project characterized the Miocene-age sub-seafloor stratigraphy in the near-offshore portion of the Gulf of Mexico adjacent to the Texas coast. The large number of industrial sources of carbon dioxide (CO₂) in coastal counties and the high density of onshore urbanization and environmentally sensitive areas make this offshore region extremely attractive for long-term storage of carbon dioxide emissions from industrial sources (CCS). The study leverages dense existing geologic data from decades of hydrocarbon exploration in and around the study area to characterize the regional geology for suitability and storage capacity. Primary products of the study include: regional static storage capacitymore » estimates, sequestration “leads” and prospects with associated dynamic capacity estimates, experimental studies of CO₂-brine-rock interaction, best practices for site characterization, a large-format ‘Atlas’ of sequestration for the study area, and characterization of potential fluid migration pathways for reducing storage risks utilizing novel high-resolution 3D (HR3D) seismic surveys. In addition, three subcontracted studies address source-to-sink matching optimization, offshore well bore management and environmental aspects. The various geologic data and interpretations are integrated and summarized in a series of cross-sections and maps, which represent a primary resource for any near-term commercial deployment of CCS in the area. The regional study characterized and mapped important geologic features (e.g., Clemente-Tomas fault zone, the regionally extensive Marginulina A and Amphistegina B confining systems, etc.) that provided an important context for regional static capacity estimates and specific sequestration prospects of the study. A static capacity estimate of the majority of the Study area (14,467 mi 2) was estimated at 86 metric Gigatonnes. While local capacity estimates are likely to be lower due to reservoir-scale characteristics, the offshore Miocene interval is a storage resource of National interest for providing CO₂ storage as an atmospheric emissions abatement strategy. The natural petroleum system was used as an analog to infer seal quality and predict possible migration pathways of fluids in an engineered system of anthropogenic CO₂ injection and storage. The regional structural features (e.g., Clemente-Tomas fault zone) that exert primary control on the trapping and distribution of Miocene hydrocarbons are expected to perform similarly for CCS. Industrial-scale CCS will require storage capacity utilizing well-documented Miocene hydrocarbon (dominantly depleted gas) fields and their larger structural closures, as well as barren (unproductive, brine-filled) closures. No assessment was made of potential for CO₂ utilization for enhanced oil and gas recovery. The use of 3D numerical fluid flow simulations have been used in the study to greatly assist in characterizing the potential storage capacity of a specific reservoir. Due to the complexity of geologic systems (stratigraphic heterogeneity) and inherent limitations on producing a 3D geologic model, these simulations are typically simplified scenarios that explore the influence of model property variability (sensitivity study). A specific site offshore San Luis Pass (southern Galveston Island) was undertaken successfully, indicating stacked storage potential. Downscaling regional capacity estimates to the local scale (and the inverse) has proven challenging, and remains an outstanding gap in capacity assessments. In order to characterize regional seal performance and identify potential brine and CO₂ leakage pathways, results from three high-resolution 3D (HR3D) seismic datasets acquired by the study using novel HR3D (P-Cable) acquisition system showed steady and significant improvements in data quality because of improved acquisition and processing technique. Finely detailed faults and stratigraphy in the shallowest 1000 milliseconds (~800 m) of data allowed for the identification and mapping of unconformable surfaces including what is probably a surface associated with the last Pleistocene glacial lowstand. The identification of a previously unrecognized (in commercial seismic data) gas chimney that was clearly defined in the 2013 HR3D survey, indicates that HR3D surveys may be useful as both a characterization tool for the overburden of a potential carbon sequestration site and as an additional monitoring tool for future engineered injection sites. Geochemical modeling indicated that injection of CO₂ would result in minor dissolution of calcite, K-feldspar and albite. In addition, modeling of typical brines in Miocene age rocks indicate that approximately 5% of injection capacity would result from CO₂ dissolution into the brine. After extensive searches, no rock samples of the Marginulina A and Amphistegina B seals (“caprocks”) were obtained, but analyses of available core samples of other Miocene age mudrocks (seals or caprocks) indicate that they have sealing ability sufficient for potential CO 2 storage in underlying sandstone units.« less

Additional boundary conditions and surface exciton dispersion relations

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

Rimbey, P.R.

1977-01-15

The surface-exciton dispersion curves in ZnO are derived from the surface impedances developed by Fuchs and Kliewer (FK) and Rimbey and Mahan (RM) including retardation. There exists a distinctive splitting between the two dispersions, the FK additional boundary conditions having longitudinal character, the RM additional boundary conditions being transverse. Surface-mode attenuation due to spatial dispersion is more pronouced in the RM formalism, although inclusion of a phenomenological damping parameter does not alter either dispersion curve. (AIP)

The Effect of Simulated Microgravity Environment of RWV Bioreactors on Surface Reactions and Adsorption of Serum Proteins on Bone-bioactive Microcarriers

NASA Technical Reports Server (NTRS)

Radin, Shula; Ducheyne, P.; Ayyaswamy, P. S.

2003-01-01

Biomimetically modified bioactive materials with bone-like surface properties are attractive candidates for use as microcarriers for 3-D bone-like tissue engineering under simulated microgravity conditions of NASA designed rotating wall vessel (RWV) bioreactors. The simulated microgravity environment is attainable under suitable parametric conditions of the RWV bioreactors. Ca-P containing bioactive glass (BG), whose stimulatory effect on bone cell function had been previously demonstrated, was used in the present study. BG surface modification via reactions in solution, resulting formation of bone-like minerals at the surface and adsorption of serum proteins is critical for obtaining the stimulatory effect. In this paper, we report on the major effects of simulated microgravity conditions of the RWV on the BG reactions surface reactions and protein adsorption in physiological solutions. Control tests at normal gravity were conducted at static and dynamic conditions. The study revealed that simulated microgravity remarkably enhanced reactions involved in the BG surface modification, including BG dissolution, formation of bone-like minerals at the surface and adsorption of serum proteins. Simultaneously, numerical models were developed to simulate the mass transport of chemical species to and from the BG surface under normal gravity and simulated microgravity conditions. The numerical results showed an excellent agreement with the experimental data at both testing conditions.

Ions, metabolites, and cells: Water as a reporter of surface conditions during bacterial growth.

PubMed

Jarisz, Tasha A; Lane, Sarah; Gozdzialski, Lea; Hore, Dennis K

2018-06-14

Surface-specific nonlinear vibrational spectroscopy, combined with bulk solution measurements and imaging, is used to study the surface conditions during the growth of E. coli. As a result of the silica high surface charge density, the water structure at the silica-aqueous interface is known to be especially sensitive to pH and ionic strength, and surface concentration profiles develop that can be appreciably different from the bulk solution conditions. We illustrate that, in the presence of growing cells, a unique surface micro-environment is established as a result of metabolites accumulating on the silica surface. Even in the subsequent absence of the cells, this surface layer works to reduce the interfacial ionic strength as revealed by the enhanced signal from surface water molecules. In the presence of growing cells, an additional boost in surface water signal is attributed to a local pH that is higher than that of the bulk solution.

Ions, metabolites, and cells: Water as a reporter of surface conditions during bacterial growth

NASA Astrophysics Data System (ADS)

Jarisz, Tasha A.; Lane, Sarah; Gozdzialski, Lea; Hore, Dennis K.

2018-06-01

Surface-specific nonlinear vibrational spectroscopy, combined with bulk solution measurements and imaging, is used to study the surface conditions during the growth of E. coli. As a result of the silica high surface charge density, the water structure at the silica-aqueous interface is known to be especially sensitive to pH and ionic strength, and surface concentration profiles develop that can be appreciably different from the bulk solution conditions. We illustrate that, in the presence of growing cells, a unique surface micro-environment is established as a result of metabolites accumulating on the silica surface. Even in the subsequent absence of the cells, this surface layer works to reduce the interfacial ionic strength as revealed by the enhanced signal from surface water molecules. In the presence of growing cells, an additional boost in surface water signal is attributed to a local pH that is higher than that of the bulk solution.

Generation of synthetic surface electromyography signals under fatigue conditions for varying force inputs using feedback control algorithm.

PubMed

Venugopal, G; Deepak, P; Ghosh, Diptasree M; Ramakrishnan, S

2017-11-01

Surface electromyography is a non-invasive technique used for recording the electrical activity of neuromuscular systems. These signals are random, complex and multi-component. There are several techniques to extract information about the force exerted by muscles during any activity. This work attempts to generate surface electromyography signals for various magnitudes of force under isometric non-fatigue and fatigue conditions using a feedback model. The model is based on existing current distribution, volume conductor relations, the feedback control algorithm for rate coding and generation of firing pattern. The result shows that synthetic surface electromyography signals are highly complex in both non-fatigue and fatigue conditions. Furthermore, surface electromyography signals have higher amplitude and lower frequency under fatigue condition. This model can be used to study the influence of various signal parameters under fatigue and non-fatigue conditions.

Surface origin and control of resonance Raman scattering and surface band gap in indium nitride

NASA Astrophysics Data System (ADS)

Alarcón-Lladó, Esther; Brazzini, Tommaso; Ager, Joel W.

2016-06-01

Resonance Raman scattering measurements were performed on indium nitride thin films under conditions where the surface electron concentration was controlled by an electrolyte gate. As the surface condition is tuned from electron depletion to accumulation, the spectral feature at the expected position of the (E 1, A 1) longitudinal optical (LO) near 590 cm-1 shifts to lower frequency. The shift is reversibly controlled with the applied gate potential, which clearly demonstrates the surface origin of this feature. The result is interpreted within the framework of a Martin double resonance, where the surface functions as a planar defect, allowing the scattering of long wavevector phonons. The allowed wavevector range, and hence the frequency, is modulated by the electron accumulation due to band gap narrowing. A surface band gap reduction of over 500 meV is estimated for the conditions of maximum electron accumulation. Under conditions of electron depletion, the full InN bandgap (E g  =  0.65 eV) is expected at the surface. The drastic change in the surface band gap is expected to influence the transport properties of devices which utilize the surface electron accumulation layer.

The influence of initial and surface boundary conditions on a model-generated January climatology

NASA Technical Reports Server (NTRS)

Wu, K. F.; Spar, J.

1981-01-01

The influence on a model-generated January climate of various surface boundary conditions, as well as initial conditions, was studied by using the GISS coarse-mesh climate model. Four experiments - two with water planets, one with flat continents, and one with mountains - were used to investigate the effects of initial conditions, and the thermal and dynamical effects of the surface on the model generated-climate. However, climatological mean zonal-symmetric sea surface temperature is used in all four runs over the model oceans. Moreover, zero ground wetness and uniform ground albedo except for snow are used in the last experiments.

Volatilization modeling of two herbicides from soil in a wind tunnel experiment under varying humidity conditions.

PubMed

Schneider, Martina; Goss, Kai-Uwe

2012-11-20

Volatilization of pesticides from the bare soil surface is drastically reduced when the soil is under dry conditions (i.e., water content lower than the permanent wilting point). This effect is caused by the hydrated mineral surfaces that become available as additional sorption sites under dry conditions. However, established volatilization models do not explicitly consider the hydrated mineral surfaces as an independent sorption compartment and cannot correctly cover the moisture effect on volatilization. Here we integrated the existing mechanistic understanding of sorption of organic compounds to mineral surfaces and its dependence on the hydration status into a simple volatilization model. The resulting model was tested with reported experimental data for two herbicides from a wind tunnel experiment under various well-defined humidity conditions. The required equilibrium sorption coefficients of triallate and trifluralin to the mineral surfaces, K(min/air), at 60% relative humidity were fitted to experimental data and extrapolated to other humidity conditions. The model captures the general trend of the volatilization in different humidity scenarios. The results reveal that it is essential to have high quality input data for K(min/air), the available specific surface area (SSA), the penetration depth of the applied pesticide solution, and the humidity conditions in the soil. The model approach presented here in combination with an improved description of the humidity conditions under dry conditions can be integrated into existing volatilization models that already work well for humid conditions but still lack the mechanistically based description of the volatilization process under dry conditions.

Multiproxy reconstruction of tropical Pacific Holocene temperature gradients and water column structure

NASA Astrophysics Data System (ADS)

Arbuszewski, J. A.; Oppo, D.; Huang, K.; Dubois, N.; Galy, V.; Mohtadi, M.; Herbert, T.; Rosenthal, Y.; Linsley, B. K.

2012-12-01

The El Niño-Southern Oscillation (ENSO) is the most prominent mode of tropical Pacific climate variability and has the potential to significantly impact the climate of the Indo-Pacific region and globally1. In the past, the mean state of the Pacific Ocean has, at times, resembled El Niño or La Niña conditions2. Although the dynamical relationships responsible for these changes have been studied through paleoproxy reconstructions and climate modeling, many questions remain. Recent paleoproxy based studies of tropical Pacific hydrology and surface temperature variability have hypothesized that observed climatological changes over the Holocene are directly linked to ENSO and/or mean state variability, complementing studies that dynamically relate centennial scale ENSO variability to mean state changes3-8. These studies have suggested that mid Holocene ENSO variability was low and the mean state was more "La Niña" like3-6. In the late Holocene, paleoproxy data has been interpreted as indicating an increase in ENSO variability with a more moderate mean ocean state3-6. However, alternative explanations could exist. Here, we test the hypothesis that observed climatological changes in the eastern tropical Pacific are related to mean state or ENSO variability during the Holocene. We focus our study on two sets of cores from the equatorial Pacific, with one located in the Indo-Pacific Warm Pool (BJ803-119 GGC, 117MC, sedimentation rates ~29 cm/kyr) and the other just off the Galapagos in the heart of the Eastern Cold Tongue (KNR195-5 43 GGC, 42MC, sedimentation rates ~20cm/kyr). The western site lies in the region predicted by models to show the greatest variations in temperature and water column structure in response to mean state changes, while the eastern site lies in the area most prone to changes due to ENSO variability7. Together, these sites allow us the best chance to robustly reconstruct ENSO and mean state related changes. We use a multiproxy approach and consider records from organic (sterol abundances) and inorganic proxies (Mg/Ca and δ18O of 3 planktonic foraminiferal species, % G. bulloides) to reconstruct zonal tropical Pacific (sub)surface temperature and stratification gradients over the Holocene. A benefit of using this approach is that it enables us to combine the strengths of each individual proxy to derive more robust records. We will compare our records with published paleoproxy and model studies in the Pacific and Indo-Pacific regions. Armed with this information, we aim to better understand mean state changes in the tropical Pacific over the Holocene. 1 Ropelewski, C. F. & Halpert, M. S. Monthly Weather Review 115, 1606-1626 (1987). 2 Collins, M. et al. Nature Geoscience 3, doi: 10.1038/NGEO1868 (2010). 3 Koutavas, A., Lynch-Steiglitz, J., Marchitto, T. & Sachs, J. Science 297, 226-230 (2002). 4 Moy, C. M., Seltzer, G. O., Rodbell, D. T. & Anderson, D. M. Nature 420, 162-165 (2002). 5 Conroy, J. L., Overpeck, J. T., Cole, J. E., Shanahan, T. M. & Steinitz-Kannan, M. Quaternary Science Reviews 27, 1166-1180 (2008). 6 Makou, M. C., Eglinton, T. I., Oppo, D. W. & Hughen, K. A. Geology 38, 43-46 (2010). 7 Karnauskas, K., Smerdon, J., Seager, R. & Gonzalez-Rouco, J. Journal of Climate, doi: 10.1178/JCLI-D-1111-00421.00421 (2012 (in press)). 8 Clement, A., Seager, R. & Cane, M. Paleoceanography 14, 441-456 (2000).

Surface oscillation of levitated liquid droplets under microgravity

NASA Astrophysics Data System (ADS)

Watanabe, Masahito; Hibiya, Taketoshi; Ozawa, Shumpei; Mizuno, Akitoshi

2012-07-01

Microgravity conditions have advantages of measurement of surface tension and viscosity of metallic liquids by the oscillating drop method with an electromagnetic levitation (EML) device. Thus, we are now planning the thermophysical properties, the surface tension, viscosity, density and etc., measurements of liquid alloys using the electromagnetic levitator named MSL-EML (Materials Science Laboratory Electromagnetic Levitator), which ahs been developed by the European Space Agency (ESA), installed in the International Space Station (ISS). The surface tension and the viscosity of liquid samples by the oscillating drop method are obtained from the surface oscillation frequency and damping time of surface oscillation respectively. However, analysis of oscillating drop method in EML must be improved even in the microgravity conditions, because on the EML conditions the electromagnetic force (EMF) cannot generate the surface oscillation with discretely oscillation mode. Since under microgravity the levitated droplet shape is completely spherical, the surface oscillation frequency with different oscillation modes degenerates into the single frequency. Therefore, surface tension will be not affected the EML condition under microgravity, but viscosity will be affected on the different oscillation mode of surface oscillations. Because dumping time of surface oscillation of liquid droplets depends on the oscillation modes, the case of surface oscillation including multi oscillation modes the viscosity values obtained from dumping time will be modified from the correct viscosity. Therefore, we investigate the dumping time of surface oscillation of levitated droplets with different oscillation modes and also with including multi oscillation modes using the electrostatic levitation (ESL) on ground and EML under microgravity conditions by the parabolic flight of airplane. The ESL can discretely generate the surface oscillation with different oscillation modes by the change of generation frequency of surface oscillation, so we can obtain dumping time of surface oscillation with discrete oscillation mode. We repot the results of the damping time of the surface oscillation of levitated liquid droplet by ESL and EML experiment with numerical simulation of the damped oscillation model.

City ventilation of Hong Kong at no-wind conditions

NASA Astrophysics Data System (ADS)

Yang, Lina; Li, Yuguo

We hypothesize that city ventilation due to both thermally-driven mountain slope flows and building surface flows is important in removing ambient airborne pollutants in the high-rise dense city Hong Kong at no-wind conditions. Both spatial and temporal urban surface temperature profiles are an important boundary condition for studying city ventilation by thermal buoyancy. Field measurements were carried out to investigate the diurnal thermal behavior of urban surfaces (mountain slopes, and building exterior walls and roofs) in Hong Kong by using the infrared thermography. The maximum urban surface temperature was measured in the early noon hours (14:00-15:00 h) and the minimum temperature was observed just before sunrise (5:00 h). The vertical surface temperature of the building exterior wall was found to increase with height at daytime and the opposite occurred at nighttime. The solar radiation and the physical properties of the various urban surfaces were found to be important factors affecting the surface thermal behaviors. The temperature difference between the measured maximum and minimum surface temperatures of the four selected exterior walls can be at the highest of 16.7 °C in the early afternoon hours (15:00 h). Based on the measured surface temperatures, the ventilation rate due to thermal buoyancy-induced wall surface flows of buildings and mountain slope winds were estimated through an integral analysis of the natural convection flow over a flat surface. At no-wind conditions, the total air change rate by the building wall flows (2-4 ACH) was found to be 2-4 times greater than that by the slope flows due to mountain surface (1 ACH) due to larger building exterior surface areas and temperature differences with surrounding air. The results provide useful insights into the ventilation of a high-rise dense city at no-wind conditions.

Analytic and experimental evaluation of flowing air test conditions for selected metallics in a shuttle TPS application

NASA Technical Reports Server (NTRS)

Schaefer, J. W.; Tong, H.; Clark, K. J.; Suchsland, K. E.; Neuner, G. J.

1975-01-01

A detailed experimental and analytical evaluation was performed to define the response of TD nickel chromium alloy (20 percent chromium) and coated columbium (R512E on CB-752 and VH-109 on WC129Y) to shuttle orbiter reentry heating. Flight conditions important to the response of these thermal protection system (TPS) materials were calculated, and test conditions appropriate to simulation of these flight conditions in flowing air ground test facilities were defined. The response characteristics of these metallics were then evaluated for the flight and representative ground test conditions by analytical techniques employing appropriate thermochemical and thermal response computer codes and by experimental techniques employing an arc heater flowing air test facility and flat face stagnation point and wedge test models. These results were analyzed to define the ground test requirements to obtain valid TPS response characteristics for application to flight. For both material types in the range of conditions appropriate to the shuttle application, the surface thermochemical response resulted in a small rate of change of mass and a negligible energy contribution. The thermal response in terms of surface temperature was controlled by the net heat flux to the surface; this net flux was influenced significantly by the surface catalycity and surface emissivity. The surface catalycity must be accounted for in defining simulation test conditions so that proper heat flux levels to, and therefore surface temperatures of, the test samples are achieved.

The end of an era. 1952.

PubMed

Ramsay, Alma Gaines

2012-01-01

This historical reprint from Public health nursing (Ramsay, ) summarizes the history of public health nursing services rendered by the Red Cross from its creation in 1912 until their termination in June 1951. The author was a public relations writer for the Red Cross. The paper is historically important for it provides chronology and perspective on the role of the Red Cross institutionalizing public health nursing and home nursing care in the United States during the first half of the 20(th) century. Of note are the three nursing services through which the Red Cross operated, each denoting a particular time and focus. Although Jane A. Delano is credited with the creation of the Red Cross nursing service, the initial organization was called Rural Nursing Service and was led by Fannie Clement. Within a short time, however, the Town and Country Nursing Service was created in recognition that not all of the public health nursing provided by the Red Cross was rendered in rural settings. The final transformation came when the service was again renamed, this time to highlight its more fundamental mission, as the Red Cross Public Health Nursing Service. The article is reprinted in its entirety. © 2012 Wiley Periodicals, Inc.

The importance of bony impingement in restricting flexion after total knee arthroplasty: computer simulation model with clinical correlation.

PubMed

Mizu-Uchi, Hideki; Colwell, Clifford W; Fukagawa, Shingo; Matsuda, Shuichi; Iwamoto, Yukihide; D'Lima, Darryl D

2012-10-01

We constructed patient-specific models from computed tomography data after total knee arthroplasty to predict knee flexion based on implant-bone impingement. The maximum flexion before impingement between the femur and the tibial insert was computed using a musculoskeletal modeling program (KneeSIM; LifeModeler, Inc, San Clemente, California) during a weight-bearing deep knee bend. Postoperative flexion was measured in a clinical cohort of 21 knees (low-flex group: 6 knees with <100° of flexion and high-flex group: 15 size-matched knees with >125° of flexion at 2 years). Average predicted flexion angles were within 2° of clinical measurements for the high-flex group. In the low-flex group, 4 cases had impingement involving the bone cut at the posterior condyle, and the average predicted knee flexion was 102° compared with 93° measured clinically. These results indicate that the level of the distal femoral resection should be carefully planned and that exposed bone proximal to the tips of the posterior condyles of the femoral component should be removed if there is risk of impingement. Copyright © 2012 Elsevier Inc. All rights reserved.

The Role of Clouds: An Introduction and Rapporteur Report

NASA Technical Reports Server (NTRS)

Taylor, Patrick C.

2012-01-01

This paper presents an overview of discussions during the Cloud s Role session at the Observing and Modelling Earth s Energy Flows Workshop. N. Loeb and B. Soden convened this session including 10 presentations by B. Stevens, B. Wielicki, G. Stephens, A. Clement, K. Sassen, D. Hartmann, T. Andrews, A. Del Genio, H. Barker, and M. Sugi addressing critical aspects of the role of clouds in modulating Earth energy flows. Presentation topics covered a diverse range of areas from cloud microphysics and dynamics, cloud radiative transfer, and the role of clouds in large-scale atmospheric circulations patterns in both observations and atmospheric models. The presentations and discussions, summarized below, are organized around several key questions raised during the session. (1) What is the best way to evaluate clouds in climate models? (2) How well do models need to represent clouds to be acceptable for making climate predictions? (3) What are the largest uncertainties in clouds? (4) How can these uncertainties be reduced? (5) What new observations are needed to address these problems? Answers to these critical questions are the topics of ongoing research and will guide the future direction of this area of research.

The Role of Clouds: An Introduction and Rapporteur Report

NASA Astrophysics Data System (ADS)

Taylor, Patrick C.

2012-07-01

This paper presents an overview of discussions during the Cloud's Role session at the Observing and Modelling Earth's Energy Flows Workshop. N. Loeb and B. Soden convened this session including 10 presentations by B. Stevens, B. Wielicki, G. Stephens, A. Clement, K. Sassen, D. Hartmann, T. Andrews, A. Del Genio, H. Barker, and M. Sugi addressing critical aspects of the role of clouds in modulating Earth energy flows. Presentation topics covered a diverse range of areas from cloud microphysics and dynamics, cloud radiative transfer, and the role of clouds in large-scale atmospheric circulations patterns in both observations and atmospheric models. The presentations and discussions, summarized below, are organized around several key questions raised during the session. (1) What is the best way to evaluate clouds in climate models? (2) How well do models need to represent clouds to be acceptable for making climate predictions? (3) What are the largest uncertainties in clouds? (4) How can these uncertainties be reduced? (5) What new observations are needed to address these problems? Answers to these critical questions are the topics of ongoing research and will guide the future direction of this area of research.

Space Flight and Manual Control: Implications for Sensorimotor Function on Future Missions

NASA Technical Reports Server (NTRS)

Reschke, Millard F.; Kornilova, Ludmila; Tomilovskaya, Elena; Parker, Donald E.; Leigh, R. John; Kozlovskaya, Inessa

2009-01-01

Control of vehicles, and other complex mechanical motion systems, is a high-level integrative function of the central nervous system (CNS) that requires good visual acuity, eye-hand coordination, spatial (and, in some cases, geographic) orientation perception, and cognitive function. Existing evidence from space flight research (Paloski et.al., 2008, Clement and Reschke 2008, Reschke et al., 2007) demonstrates that the function of each of these systems is altered by removing (and subsequently by reintroducing) a gravitational field that can be sensed by vestibular, proprioceptive, and haptic receptors and used by the CNS for spatial orientation, navigation, and coordination of movements. Furthermore, much of the operational performance data collected as a function of space flight has not been available for independent analysis, and those data that have been reviewed are equivocal owing to uncontrolled environmental and/or engineering factors. Thus, our current understanding, when it comes to manual control, is limited primarily to a review of those situations where manual control has been a factor. One of the simplest approaches to the manual control problem is to review shuttle landing data. See the Figure below for those landing for which we have Shuttle velocities over the runway threshold.

Single-Spot Yellow Laser Versus Conventional Green Laser on Panretinal Photocoagulation: Patient Pain Scores and Preferences.

PubMed

González-Saldivar, Gerardo; Rojas-Juárez, Sergio; Espinosa-Soto, Itzel; Sánchez-Ramos, Jorge; Jaurieta-Hinojosa, Noel; Ramírez-Estudillo, Abel

2017-11-01

Panretinal photocoagulation (PRP) is the mainstay therapy for proliferative diabetic retinopathy. Pain during and after its application is a complication that affects patients' therapeutic adherence. This study aimed to compare pain perception and patient preference for the 577-nm yellow laser (YL-577) (LIGHTL as 577; LIGHTMED, San Clemente, CA) and the conventional 532-nm green laser (GL-532) (Purepoint Laser; Alcon, Fort Worth, TX) with PRP. A total of 92 patient eyes with proliferative diabetic retinopathy treated with PRP were randomly assigned to receive both GL-532 and YL-577 (184 eyes) - one on each eye, with the order of application randomized, as well. Afterward, verbal rapid answer and visual analogue scale (VAS) scores for pain perception and patient preference were evaluated. VAS score was 7 ± 2 for the GL-532 group compared to 5 ± 3 in the YL-577 group (P = .001). Overall, 75% of the patients preferred YL-577 therapy if they were to receive a second PRP session. The use of YL-577 as an alternative approach for PRP reduces pain perception and is preferred by patients. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:902-905.]. Copyright 2017, SLACK Incorporated.

Identifying Rhodamine Dye Plume Sources in Near-Shore Oceanic Environments by Integration of Chemical and Visual Sensors

PubMed Central

Tian, Yu; Kang, Xiaodong; Li, Yunyi; Li, Wei; Zhang, Aiqun; Yu, Jiangchen; Li, Yiping

2013-01-01

This article presents a strategy for identifying the source location of a chemical plume in near-shore oceanic environments where the plume is developed under the influence of turbulence, tides and waves. This strategy includes two modules: source declaration (or identification) and source verification embedded in a subsumption architecture. Algorithms for source identification are derived from the moth-inspired plume tracing strategies based on a chemical sensor. The in-water test missions, conducted in November 2002 at San Clemente Island (California, USA) in June 2003 in Duck (North Carolina, USA) and in October 2010 at Dalian Bay (China), successfully identified the source locations after autonomous underwater vehicles tracked the rhodamine dye plumes with a significant meander over 100 meters. The objective of the verification module is to verify the declared plume source using a visual sensor. Because images taken in near shore oceanic environments are very vague and colors in the images are not well-defined, we adopt a fuzzy color extractor to segment the color components and recognize the chemical plume and its source by measuring color similarity. The source verification module is tested by images taken during the CPT missions. PMID:23507823

Wetlands inform how climate extremes influence surface water expansion and contraction

NASA Astrophysics Data System (ADS)

Vanderhoof, Melanie K.; Lane, Charles R.; McManus, Michael G.; Alexander, Laurie C.; Christensen, Jay R.

2018-03-01

Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985-2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage. From these findings, we can expect that shifts in precipitation and evaporative demand will have uneven effects on surface water quantity. Accurate predictions regarding the effect of climate change on surface water quantity will require consideration of hydrology-related landscape characteristics including wetland storage and arrangement.

Groundwater infiltration, surface water inflow and sewerage exfiltration considering hydrodynamic conditions in sewer systems.

PubMed

Karpf, Christian; Hoeft, Stefan; Scheffer, Claudia; Fuchs, Lothar; Krebs, Peter

2011-01-01

Sewer systems are closely interlinked with groundwater and surface water. Due to leaks and regular openings in the sewer system (e.g. combined sewer overflow structures with sometimes reverse pressure conditions), groundwater infiltration and surface water inflow as well as exfiltration of sewage take place and cannot be avoided. In the paper a new hydrodynamic sewer network modelling approach will be presented, which includes--besides precipitation--hydrographs of groundwater and surface water as essential boundary conditions. The concept of the modelling approach and the models to describe the infiltration, inflow and exfiltration fluxes are described. The model application to the sewerage system of the City of Dresden during a flood event with complex conditions shows that the processes of infiltration, exfiltration and surface water inflows can be described with a higher reliability and accuracy, showing that surface water inflow causes a pronounced system reaction. Further, according to the simulation results, a high sensitivity of exfiltration rates on the in-sewer water levels and a relatively low influence of the dynamic conditions on the infiltration rates were found.

Application of Pilates principles increases paraspinal muscle activation.

PubMed

Andrade, Letícia Souza; Mochizuki, Luís; Pires, Flávio Oliveira; da Silva, Renato André Sousa; Mota, Yomara Lima

2015-01-01

To analyze the effect of Pilates principles on the EMG activity of abdominal and paraspinal muscles on stable and unstable surfaces. Surface EMG data about the rectus abdominis (RA), iliocostalis (IL) and lumbar multifidus (MU) of 19 participants were collected while performing three repetitions of a crunch exercise in the following conditions: 1) with no Pilates technique and stable surface (nP + S); 2) with no Pilates technique and unstable surface (nP + U); 3) with Pilates technique and stable surface (P + S); 4) with Pilates and unstable surface (P + U). The EMG Fanalysis was conducted using a custom-made Matlab(®) 10. There was no condition effect in the RA iEMG with stable and unstable surfaces (F(1,290) = 0 p = 0.98) and with and without principles (F(1,290) = 1.2 p = 0.27). IL iEMG was higher for the stable surface condition (F(1,290) = 32.3 p < 0.001) with Pilates principles (F(1,290) = 21.9 p < 0.001). The MU iEMG was higher for the stable surface condition with and without Pilates principles (F(1,290) = 84.9 p < 0.001). Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of reusable surface insulation for space shuttle over a range of heat-transfer rate and surface temperature

NASA Technical Reports Server (NTRS)

Chapman, A. J.

1973-01-01

Reusable surface insulation materials, which were developed as heat shields for the space shuttle, were tested over a range of conditions including heat-transfer rates between 160 and 620 kW/sq m. The lowest of these heating rates was in a range predicted for the space shuttle during reentry, and the highest was more than twice the predicted entry heating on shuttle areas where reusable surface insulation would be used. Individual specimens were tested repeatedly at increasingly severe conditions to determine the maximum heating rate and temperature capability. A silica-base material experienced only minimal degradation during repeated tests which included conditions twice as severe as predicted shuttle entry and withstood cumulative exposures three times longer than the best mullite material. Mullite-base materials cracked and experienced incipient melting at conditions within the range predicted for shuttle entry. Neither silica nor mullite materials consistently survived the test series with unbroken waterproof surfaces. Surface temperatures for a silica and a mullite material followed a trend expected for noncatalytic surfaces, whereas surface temperatures for a second mullite material appeared to follow a trend expected for a catalytic surface.

Wear Behavior of Medium Carbon Steel with Biomimetic Surface Under Starved Lubricated Conditions

NASA Astrophysics Data System (ADS)

Zhang, Zhihui; Shao, Feixian; Liang, Yunhong; Lin, Pengyu; Tong, Xin; Ren, Luquan

2017-07-01

Friction and wear under starved lubrication condition are both key life-related factors for mechanical performance of many structural parts. In this paper, different surface morphologies on medium carbon steel were fabricated using laser, inspired by the surface coupling effect of biological system. The friction and sliding wear behaviors of biomimetic specimens (characterized by convex and concave units on the specimen surface) were studied under starved lubrication condition. The stress distribution on different sliding surfaces under sliding friction was studied using finite element method. The results showed that the tribological performance of studied surfaces under starved lubrication condition depended not only on the surface morphology but also on the structure of biomimetic units below surface (subsurface structure). The friction coefficient of biomimetic surface was effectively reduced by the concave unit depth, while the refined microstructure with higher hardness led to the much better wear resistance. In addition to lubricant reserving and wear debris trapping effect derived from the surface concave morphology, it was believed that the well-formed subsurface structure of biomimetic units could carry much heavy loads against tribopair, which enhanced the function of surface topography and resulted in complementary lubrication in the wear contact area. The uniform stress distribution on the entire biomimetic surface also played an important role in stabilizing the friction coefficient and reducing the wear cracks.

Distinguishing the road conditions of dry, aquaplane, and frozen by using a three-color infrared camera

NASA Astrophysics Data System (ADS)

Tabuchi, Toru; Yamagata, Shigeki; Tamura, Tetsuo

2003-04-01

There are increasing demands for information to avoid accident in automobile traffic increase. We will discuss that an infrared camera can identify three conditions (dry, aquaplane, frozen) of the road surface. Principles of this method are; 1.We have found 3-color infrared camera can distinguish those conditions using proper data processing 2.The emissivity of the materials on the road surface (conclete, water, ice) differs in three wavelength regions. 3.The sky's temperature is lower than the road's. The emissivity of the road depends on the road surface conditions. Therefore, 3-color infrared camera measure the energy reflected from the sky on the road surface and self radiation of road surface. The road condition can be distinguished by processing the energy pattern measured in three wavelength regions. We were able to collect the experimental results that the emissivity of conclete is differ from water. The infrared camera whose NETD (Noise Equivalent Temperature Difference) at each 3-wavelength is 1.0C or less can distinguish the road conditions by using emissivity difference.

Comparative evaluation of bonding strength of computer aided machined ceramic, pressable ceramic, and milled metal implant abutment copings and effect of surface conditioning on bonding strength: An in vitro study

PubMed Central

Rani, Sapna; Verma, Mahesh; Gill, Shubhra; Gupta, Rekha

2016-01-01

Background/Purpose: The aim of this study was to compare the shear bond strength of computer aided design/computer aided machined ceramic (CAD/CAM), pressable ceramic, and milled metal implant copings on abutment and the effect of surface conditioning on bonding strength. Materials and Methods: A total of 90 test samples were fabricated on three titanium abutments. Among 90 test samples, 30 copings were fabricated by CAD/CAM, 30 by pressable, and 30 by milling of titanium metal. These 30 test samples in each group were further subdivided equally for surface treatment. Fifteen out of 30 test samples in each group were surface conditioned with airborne particle abrasion. All the 90 test samples were luted on abutment with glass ionomer cement. Bonding strength was evaluated for all the samples using universal testing machine at a crosshead speed of 5 mm/min. The results obtained were compared and evaluated using one-way ANOVA with post-hoc and unpaired t-test at a significance level of 0.05. Results: The mean difference for CAD/CAM surface conditioned subgroup was 1.28 ± 0.12, for nonconditioned subgroup was 1.20 ± 0.11. The mean difference for pressable surface conditioned subgroup was 1.18 ± 0.04, and for nonconditioned subgroup was 0.75 ± 0.28. The mean difference for milled metal surface conditioned subgroup was 2.57 ± 0.58, and for nonconditioned subgroup was 1.49 ± 0.15. Conclusions: On comparison of bonding strength, milled metal copings had an edge over the other two materials, and surface conditioning increased the bond strength. PMID:27141163

Satellite remotely-sensed land surface parameters and their climatic effects for three metropolitan regions

USGS Publications Warehouse

Xian, George

2008-01-01

By using both high-resolution orthoimagery and medium-resolution Landsat satellite imagery with other geospatial information, several land surface parameters including impervious surfaces and land surface temperatures for three geographically distinct urban areas in the United States – Seattle, Washington, Tampa Bay, Florida, and Las Vegas, Nevada, are obtained. Percent impervious surface is used to quantitatively define the spatial extent and development density of urban land use. Land surface temperatures were retrieved by using a single band algorithm that processes both thermal infrared satellite data and total atmospheric water vapor content. Land surface temperatures were analyzed for different land use and land cover categories in the three regions. The heterogeneity of urban land surface and associated spatial extents were shown to influence surface thermal conditions because of the removal of vegetative cover, the introduction of non-transpiring surfaces, and the reduction in evaporation over urban impervious surfaces. Fifty years of in situ climate data were integrated to assess regional climatic conditions. The spatial structure of surface heating influenced by landscape characteristics has a profound influence on regional climate conditions, especially through urban heat island effects.

Electric Double-Layer Interaction between Dissimilar Charge-Conserved Conducting Plates.

PubMed

Chan, Derek Y C

2015-09-15

Small metallic particles used in forming nanostructured to impart novel optical, catalytic, or tribo-rheological can be modeled as conducting particles with equipotential surfaces that carry a net surface charge. The value of the surface potential will vary with the separation between interacting particles, and in the absence of charge-transfer or electrochemical reactions across the particle surface, the total charge of each particle must also remain constant. These two physical conditions require the electrostatic boundary condition for metallic nanoparticles to satisfy an equipotential whole-of-particle charge conservation constraint that has not been studied previously. This constraint gives rise to a global charge conserved constant potential boundary condition that results in multibody effects in the electric double-layer interaction that are either absent or are very small in the familiar constant potential or constant charge or surface electrochemical equilibrium condition.

Recognition and Classification of Road Condition on the Basis of Friction Force by Using a Mobile Robot

NASA Astrophysics Data System (ADS)

Watanabe, Tatsuhito; Katsura, Seiichiro

A person operating a mobile robot in a remote environment receives realistic visual feedback about the condition of the road on which the robot is moving. The categorization of the road condition is necessary to evaluate the conditions for safe and comfortable driving. For this purpose, the mobile robot should be capable of recognizing and classifying the condition of the road surfaces. This paper proposes a method for recognizing the type of road surfaces on the basis of the friction between the mobile robot and the road surfaces. This friction is estimated by a disturbance observer, and a support vector machine is used to classify the surfaces. The support vector machine identifies the type of the road surface using feature vector, which is determined using the arithmetic average and variance derived from the torque values. Further, these feature vectors are mapped onto a higher dimensional space by using a kernel function. The validity of the proposed method is confirmed by experimental results.

Ab Initio Surface Phase Diagrams for Coadsorption of Aromatics and Hydrogen on the Pt(111) Surface

DOE PAGES

Ferguson, Glen Allen; Vorotnikov, Vassili; Wunder, Nicholas; ...

2016-11-02

Supported metal catalysts are commonly used for the hydrogenation and deoxygenation of biomass-derived aromatic compounds in catalytic fast pyrolysis. To date, the substrate-adsorbate interactions under reaction conditions crucial to these processes remain poorly understood, yet understanding this is critical to constructing detailed mechanistic models of the reactions important to catalytic fast pyrolysis. Density functional theory (DFT) has been used in identifying mechanistic details, but many of these works assume surface models that are not representative of realistic conditions, for example, under which the surface is covered with some concentration of hydrogen and aromatic compounds. In this study, we investigate hydrogen-guaiacolmore » coadsorption on Pt(111) using van der Waals-corrected DFT and ab initio thermodynamics over a range of temperatures and pressures relevant to bio-oil upgrading. We find that relative coverage of hydrogen and guaiacol is strongly dependent on the temperature and pressure of the system. Under conditions relevant to ex situ catalytic fast pyrolysis (CFP; 620-730 K, 1-10 bar), guaiacol and hydrogen chemisorb to the surface with a submonolayer hydrogen (~0.44 ML H), while under conditions relevant to hydrotreating (470-580 K, 10-200 bar), the surface exhibits a full-monolayer hydrogen coverage with guaiacol physisorbed to the surface. These results correlate with experimentally observed selectivities, which show ring saturation to methoxycyclohexanol at hydrotreating conditions and deoxygenation to phenol at CFP-relevant conditions. Additionally, the vibrational energy of the adsorbates on the surface significantly contributes to surface energy at higher coverage. Ignoring this contribution results in not only quantitatively, but also qualitatively incorrect interpretation of coadsorption, shifting the phase boundaries by more than 200 K and ~10-20 bar and predicting no guaiacol adsorption under CFP and hydrotreating conditions. We discuss the implications of this work in the context of modeling hydrogenation and deoxygenation reactions on Pt(111), and we find that only the models representative of equilibrium surface coverage can capture the hydrogenation kinetics correctly. Lastly, as a major outcome of this work, we introduce a freely available web-based tool, dubbed the Surface Phase Explorer (SPE), which allows researchers to conveniently determine surface composition for any one- or two-component system at thermodynamic equilibrium over a wide range of temperatures and pressures on any crystalline surface using standard DFT output.« less

Methods of Determining Playa Surface Conditions Using Remote Sensing

DTIC Science & Technology

1987-10-08

NO. 11. TITLE (include Security Classification) METHODS OF DETERMINING PLAYA SURFACE CONDITIONS USING REMOTE SENSING 12. PERSONAL AUTHOR(S) J. PONDER...PLAYA SURFACE CONDITIONS USING REMOTE SENSING J. Ponder Henley U. S. Army Engineer Topographic Laboratories Fort Belvoir, Virginia 22060-5546 "ABSTRACT...geochemistry, hydrology and remote sensing but all of these are important to the understanding of these unique geomorphic features. There is a large body

Sulfur in the Early Martian Atmosphere Revisited: Experiments with a 3-D Global Climate Model

NASA Astrophysics Data System (ADS)

Kerber, L.; Forget, F.; Wordsworth, R.

2013-09-01

Data returned from the surface of Mars during the 1970s revealed intriguing geological evidence for a warmer and wetter early martian climate. Dendritic valley networks were discovered by Mariner 9 on ancient Noachian terrain [1], indicating that liquid water had flowed across the surface in the distant past. Since this time, geological investigations into early Martian history have attempted to ascertain the nature and level of activity of the early Martian hydrological cycle [e.g. 2-5] while atmospheric modeling efforts have focused on how the atmosphere could be warmed to temperatures great enough to sustain such activity [see 6-7 for reviews]. Geological and spectroscopic investigations have refined the history and chronology of Noachian Mars over time, and circulation of liquid water has been invoked to explain several spatially and temporally distinct morphological and chemical signatures found in the geological record. Detections of iron and magnesium-rich clays are widespread in the oldest Martian terrains, suggesting a period of pH-neutral aqueous alteration [e.g., 8]. Valley network incision also took place during the Noachian period [9]. Some chains of river valleys and craters lakes extend for thousands of kilometers, suggesting temperatures at least clement enough for sustained ice-covered flow [3,10]. The commencement of valley network incision is not well constrained, but the period of Mg/Fe clay formation appears to have ended before the termination of valley network formation, as the visible fluvial systems appear to have remobilized existing clays rather than forming them [5,8]. There is also evidence that the cessation of valley network formation was abrupt [11]. Towards the end of the Noachian, erosion rates appear to have been significantly higher than during subsequent periods, a process that has also been attributed to aqueous processes [12]. A period of sulfate formation followed, likely characterized by acidic, evaporitic playa environments [8]. A successful working model for the early Martian atmosphere and hydrosphere must be able not only to produce conditions suitable for liquid water at the surface, but also to explain how the nature of this aqueous activity changed over time and eventually diminished. There are two major end-member hypotheses: first, that early Mars was wet and warm, with a sustained greenhouse that made it possible for liquid water to be stable on the surface for extended periods [e.g., 2, 12-14], and second, that early Mars was generally cold, and that most of the aqueous alteration took place underground [3,5] or during transient warm periods tied to impact cratering [15], or volcanism [16]. In both of these scenarios it is generally agreed that in order to make valley networks and sulfate deposits, a hydrological cycle is needed which is able to recycle water from the lowlands back to the highlands (i.e., the one-time emptying of a regional aquifer would not be sufficient to create the observed features) [4,17]. This would require some precipitation to fall on the southern highlands, either flowing overland or filtering into groundwater aquifers. In both cases, volcanic gases (especially SO2) have been suggested as a possible way of creating either a sustained or transient greenhouse. Several researchers have tested the addition of SO2 to climate models in order to assess whether it would provide an adequate amount of greenhouse warming to allow liquid water to flow across the surface [18-21], with differing results. Postawko and Kuhn [18] found a warming effect of 14 K in a 0.1 bar atmosphere with an SO2 abundance of 1000 ppm. Johnson et al. [20] used a 3-D global circulation model and found a warming of 15-25 K for 245 ppm of SO2 in a dry 0.5 bar atmosphere. Tian et al. [21] used a 1-D model to explore a wide range of SO2 mixing values and CO2 partial pressures, finding a warming of around ~25 K for 100 ppm in a 0.5 bar atmosphere with a fully saturated troposphere (~40 K for a 1 bar atmosphere). These authors also included the effect of sulfate aerosol particles, which caused a dramatic cooling effect which more than canceled the warming caused by the SO2 gas [21]. Here we reconsider the efficacy of a sulfurinduced greenhouse in early Noachian history using the LMD (Laboratoire de Météorologie Dynamique) 3-D Generic Climate Model (LMD-GCM), exploring the effects of SO2, H2S, and sulfate and S8 aerosols on the surface temperature, and the expected photochemical lifetime of SO2 in the atmosphere.

Influencing factors on the visibility of surface distresses

NASA Astrophysics Data System (ADS)

Smęt, Wojciech; Skakuj, Marek

2018-05-01

A systematic and future-oriented maintenance management requires quality-assured data regarding the condition of the roadway. An important characteristic for assessing the condition of the road surface are cracks [1]. Experience has proven that the road surface temperature and residual humidity can influence the visibility of cracks. To investigate and quantify these influencing factors in more detail, the Federal Ministry of Transport and Digital Infrastructure has implemented a comprehensive research project [2], during which several measurement campaigns were carried out at different seasons and at different temperatures and humidity degrees of the road surface. The visibility of the cracks was assessed using the German approach ZTV ZEB-StB [3]. After evaluating the cracks, the data was synchronized and the network allocation of the geo-referenced raw data was realized. The relevant condition performance indicators were calculated subsequently. For each evaluation section of 100 meters length, the mean road surface temperature was calculated and, if available, the type and year of construction of the surface course was determined. The evaluated data was visualized to establish correlations between the data and the influencing factors. For the statistical analysis of the results, a total of six comparative scenarios were defined in which the influencing factors of road surface temperature and residual humidity were assessed. This paper documents the results of the research project. In order to obtain a uniform and comparable picture of the condition of the road surface over the years and thus to be able to observe the aging process of the road surface, the measurement campaigns are to be carried out under defined conditions. The research project included proposals for defining and further specifying the measurement conditions.

Phosphorus Release to Floodwater from Calcareous Surface Soils and Their Corresponding Subsurface Soils under Anaerobic Conditions.

PubMed

Jayarathne, P D K D; Kumaragamage, D; Indraratne, S; Flaten, D; Goltz, D

2016-07-01

Enhanced phosphorus (P) release from soils to overlying water under flooded, anaerobic conditions has been well documented for noncalcareous and surface soils, but little information is available for calcareous and subsurface soils. We compared the magnitude of P released from 12 calcareous surface soils and corresponding subsurface soils to overlying water under flooded, anaerobic conditions and examined the reasons for the differences. Surface (0-15 cm) and subsurface (15-30 cm) soils were packed into vessels and flooded for 8 wk. Soil redox potential and concentrations of dissolved reactive phosphorus (DRP) and total dissolved Ca, Mg, Fe, and Mn in floodwater and pore water were measured weekly. Soil test P was significantly smaller in subsurface soils than in corresponding surface soils; thus, the P release to floodwater from subsurface soils was significantly less than from corresponding surface soils. Under anaerobic conditions, floodwater DRP concentration significantly increased in >80% of calcareous surface soils and in about 40% of subsurface soils. The increase in floodwater DRP concentration was 2- to 17-fold in surface soils but only 4- to 7-fold in subsurface soils. With time of flooding, molar ratios of Ca/P and Mg/P in floodwater increased, whereas Fe/P and Mn/P decreased, suggesting that resorption and/or reprecipitation of P took place involving Fe and Mn. Results indicate that P release to floodwater under anaerobic conditions was enhanced in most calcareous soils. Surface and subsurface calcareous soils in general behaved similarly in releasing P under flooded, anaerobic conditions, with concentrations released mainly governed by initial soil P concentrations. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

An implicit-iterative solution of the heat conduction equation with a radiation boundary condition

NASA Technical Reports Server (NTRS)

Williams, S. D.; Curry, D. M.

1977-01-01

For the problem of predicting one-dimensional heat transfer between conducting and radiating mediums by an implicit finite difference method, four different formulations were used to approximate the surface radiation boundary condition while retaining an implicit formulation for the interior temperature nodes. These formulations are an explicit boundary condition, a linearized boundary condition, an iterative boundary condition, and a semi-iterative boundary method. The results of these methods in predicting surface temperature on the space shuttle orbiter thermal protection system model under a variety of heating rates were compared. The iterative technique caused the surface temperature to be bounded at each step. While the linearized and explicit methods were generally more efficient, the iterative and semi-iterative techniques provided a realistic surface temperature response without requiring step size control techniques.

Interferometric detection of nanoparticles

NASA Astrophysics Data System (ADS)

Hayrapetyan, Karen

Interferometric surfaces enhance light scattering from nanoparticles through constructive interference of partial scattered waves. By placing the nanoparticles on interferometric surfaces tuned to a special surface phase interferometric condition, the particles are detectable in the dilute limit through interferometric image contrast in a heterodyne light scattering configuration, or through diffraction in a homodyne scattering configuration. The interferometric enhancement has applications for imaging and diffractive biosensors. We present a modified model based on Double Interaction (DI) to explore bead-based detection mechanisms using imaging, scanning and diffraction. The application goal of this work is to explore the trade-offs between the sensitivity and throughput among various detection methods. Experimentally we use thermal oxide on silicon to establish and control surface interferometric conditions. Surface-captured gold beads are detected using Molecular Interferometric Imaging (MI2) and Spinning-Disc Interferometry (SDI). Double-resonant enhancement of light scattering leads to high-contrast detection of 100 nm radius gold nanoparticles on an interferometric surface. The double-resonance condition is achieved when resonance (or anti-resonance) from an asymmetric Fabry-Perot substrate coincides with the Mie resonance of the gold nanoparticle. The double-resonance condition is observed experimentally using molecular interferometric imaging (MI2). An invisibility condition is identified for which the gold nanoparticles are optically cloaked by the interferometric surface.

Foam Core Particleboards with Intumescent FRT Veneer: Cone Calorimeter Testing With Varying Adhesives, Surface Layer Thicknesses, and Processing Conditions

Treesearch

Mark A. Dietenberger; Johannes Welling; Ali Shalbafan

2014-01-01

Intumescent FRT Veneers adhered to the surface of foam core particleboard to provide adequate fire protection were evaluated by means of cone calorimeter tests (ASTM E1354). The foam core particleboards were prepared with variations in surface layer treatment, adhesives, surface layer thicknesses, and processing conditions. Ignitability, heat release rate profile, peak...

Evaluation of surface layer flux parameterizations using in-situ observations

NASA Astrophysics Data System (ADS)

Katz, Jeremy; Zhu, Ping

2017-09-01

Appropriate calculation of surface turbulent fluxes between the atmosphere and the underlying ocean/land surface is one of the major challenges in geosciences. In practice, the surface turbulent fluxes are estimated from the mean surface meteorological variables based on the bulk transfer model combined with the Monnin-Obukhov Similarity (MOS) theory. Few studies have been done to examine the extent to which such a flux parameterization can be applied to different weather and surface conditions. A novel validation method is developed in this study to evaluate the surface flux parameterization using in-situ observations collected at a station off the coast of Gulf of Mexico. The main findings are: (a) the theoretical prediction that uses MOS theory does not match well with those directly computed from the observations. (b) The largest spread in exchange coefficients is shown in strong stable conditions with calm winds. (c) Large turbulent eddies, which depend strongly on the mean flow pattern and surface conditions, tend to break the constant flux assumption in the surface layer.

The role of titanium nitride supports for single-atom platinum-based catalysts in fuel cell technology.

PubMed

Zhang, Ren-Qin; Lee, Tae-Hun; Yu, Byung-Deok; Stampfl, Catherine; Soon, Aloysius

2012-12-28

As a first step towards a microscopic understanding of single-Pt atom-dispersed catalysts on non-conventional TiN supports, we present density-functional theory (DFT) calculations to investigate the adsorption properties of Pt atoms on the pristine TiN(100) surface, as well as the dominant influence of surface defects on the thermodynamic stability of platinized TiN. Optimized atomic geometries, energetics, and analysis of the electronic structure of the Pt/TiN system are reported for various surface coverages of Pt. We find that atomic Pt does not bind preferably to the clean TiN surface, but under typical PEM fuel cell operating conditions, i.e. strongly oxidizing conditions, TiN surface vacancies play a crucial role in anchoring the Pt atom for its catalytic function. Whilst considering the energetic stability of the Pt/TiN structures under varying N conditions, embedding Pt at the surface N-vacancy site is found to be the most favorable under N-lean conditions. Thus, the system of embedding Pt at the surface N-vacancy sites on TiN(100) surfaces could be promising catalysts for PEM fuel cells.

Automated classification of articular cartilage surfaces based on surface texture.

PubMed

Stachowiak, G P; Stachowiak, G W; Podsiadlo, P

2006-11-01

In this study the automated classification system previously developed by the authors was used to classify articular cartilage surfaces with different degrees of wear. This automated system classifies surfaces based on their texture. Plug samples of sheep cartilage (pins) were run on stainless steel discs under various conditions using a pin-on-disc tribometer. Testing conditions were specifically designed to produce different severities of cartilage damage due to wear. Environmental scanning electron microscope (SEM) (ESEM) images of cartilage surfaces, that formed a database for pattern recognition analysis, were acquired. The ESEM images of cartilage were divided into five groups (classes), each class representing different wear conditions or wear severity. Each class was first examined and assessed visually. Next, the automated classification system (pattern recognition) was applied to all classes. The results of the automated surface texture classification were compared to those based on visual assessment of surface morphology. It was shown that the texture-based automated classification system was an efficient and accurate method of distinguishing between various cartilage surfaces generated under different wear conditions. It appears that the texture-based classification method has potential to become a useful tool in medical diagnostics.

Linking morphology with activity through the lifetime of pretreated PtNi nanostructured thin film catalysts

DOE PAGES

Cullen, David A.; Lopez-Haro, Miguel; Bayle-Guillemaud, Pascale; ...

2015-04-10

In this study, the nanoscale morphology of highly active Pt 3Ni 7 nanostructured thin film fuel cell catalysts is linked with catalyst surface area and activity following catalyst pretreatments, conditioning and potential cycling. The significant role of fuel cell conditioning on the structure and composition of these extended surface catalysts is demonstrated by high resolution imaging, elemental mapping and tomography. The dissolution of Ni during fuel cell conditioning leads to highly complex, porous structures which were visualized in 3D by electron tomography. Quantification of the rendered surfaces following catalyst pretreatment, conditioning, and cycling shows the important role pore structure playsmore » in surface area, activity, and durability.« less

Sensory interaction on static balance: a comparison concerning the history of falls of community-dwelling elderly.

PubMed

Ricci, Natalia Aquaroni; de Faria Figueiredo Gonçalves, Daniele; Coimbra, Arlete Maria Valente; Coimbra, Ibsen Bellini

2009-06-01

To determine whether elderly subjects with distinct histories of falls presented differences concerning the influence of sensory interaction on balance. Cross-sectional research. Ninety-six community-dwelling elderly subjects were divided into three groups, according to the history of falls within the past year (group 1, no falls; group 2, one fall; and group 3, recurrent falls). The Clinical Test of Sensory Interaction and Balance was used to evaluate the influence of sensory inputs on standing balance. The test required the subject to maintain stability during 30 s, under six conditions: (i) firm surface with eyes open; (ii) firm surface with eyes closed; (iii) firm surface with visual conflict; (iv) unstable surface with eyes open; (v) unstable surface with eyes closed; and (vi) unstable surface with visual conflict. The time expended on conditions and the number of abnormal cases were compared between groups. Each group was evaluated in relation to its performance in the progression of conditions. More abnormal cases occurred in group 3 compared to group 1 for conditions (iv) and (v); and compared to group 2 for condition (iv). Group 3 remained less time than group 1 under conditions (iv), (v) and (vi). Groups 1, 2 and 3 presented relevant decrements in trial duration from conditions (iv) to (v). For group 3, a significant decay was also noted from condition (i) to (ii). Sensorial interaction in the elderly varies according to their history of falls. Thus, it is possible to correctly guide the rehabilitation process and to prevent sensorial decays according to an individual's history of falls.

Optimization of functionalization conditions for protein analysis by AFM

NASA Astrophysics Data System (ADS)

Arroyo-Hernández, María; Daza, Rafael; Pérez-Rigueiro, Jose; Elices, Manuel; Nieto-Márquez, Jorge; Guinea, Gustavo V.

2014-10-01

Activated vapor silanization (AVS) is used to functionalize silicon surfaces through deposition of amine-containing thin films. AVS combines vapor silanization and chemical vapor deposition techniques and allows the properties of the functionalized layers (thickness, amine concentration and topography) to be controlled by tuning the deposition conditions. An accurate characterization is performed to correlate the deposition conditions and functional-film properties. In particular, it is shown that smooth surfaces with a sufficient surface density of amine groups may be obtained with this technique. These surfaces are suitable for the study of proteins with atomic force microscopy.

Light scatter on the surface of AcrySof intraocular lenses: part II. Analysis of lenses following hydrolytic stability testing.

PubMed

Yaguchi, Shigeo; Nishihara, Hitoshi; Kambhiranond, Waraporn; Stanley, Daniel; Apple, David

2008-01-01

To investigate the surface light scatter and optical quality of AcrySof lenses (Alcon Laboratories, Inc., Fort Worth, TX) following simulated aging of 20 years. AcrySof lenses were exposed to exaggerated thermal conditions to simulate up to 20 years of aging and were tested for surface light scatter and optical quality (modulation transfer function). There were no significant differences from baseline for either the surface light scatter or optical quality of the lenses over time. The current study demonstrated that surface light scatter on AcrySof lenses did not increase under conditions simulating 20 years of aging. Because the simulated aging environment contained no protein, this work indirectly supports the finding that surface light scatter is due to the deposition of a biomaterial on the lens surface rather than changes in the material. Optical performance integrity of the test lenses was maintained under severe environmental conditions.

Effect of Loading Rate and Surface Conditions on Flexural Strength of Borosilicate Glass

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

Nie, X; Chen, Wayne; Wereszczak, Andrew A

2009-01-01

This study evaluates the loading rate and surface condition dependence of the flexural strength of a borosilicate glass. The glass specimens are subjected to three different surface treatments before four-point bending tests to study the effect of surface flaws. Quasistatic (Material Test System 810) and dynamic (Kolsky bar) experiments are performed at loading rates ranging from 0.7 to 4 x 10{sup 6} MPa/s. The results show that the flexural strength of the borosilicate glass has a strong dependence on the loading rate. A chemically etched surface produces an enhanced flexural strength by about an order of magnitude. Scanning electron microscopymore » images on fracture surfaces indicate that the failure is governed by different types of flaws under different surface treatment conditions. Edge failure is also identified for samples possessing high flexural strength.« less

75 FR 47888 - IntelliDriveSM

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-09

... activities). Environment/fuel use. Pavement conditions (e.g., snow or ice cover, surface roughness, pothole.../destination pair, by time period, weighted by trip volume. System Throughput is intended to quantify the total.... Pavement conditions such as snow or ice cover, slippery conditions, surface roughness, or pothole detection...

The influence of surface properties on the plasma dynamics in radio-frequency driven oxygen plasmas: Measurements and simulations

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

Greb, Arthur; Niemi, Kari; O'Connell, Deborah

2013-12-09

Plasma parameters and dynamics in capacitively coupled oxygen plasmas are investigated for different surface conditions. Metastable species concentration, electronegativity, spatial distribution of particle densities as well as the ionization dynamics are significantly influenced by the surface loss probability of metastable singlet delta oxygen (SDO). Simulated surface conditions are compared to experiments in the plasma-surface interface region using phase resolved optical emission spectroscopy. It is demonstrated how in-situ measurements of excitation features can be used to determine SDO surface loss probabilities for different surface materials.

Evaluating Weather Research and Forecasting Model Sensitivity to Land and Soil Conditions Representative of Karst Landscapes

NASA Astrophysics Data System (ADS)

Johnson, Christopher M.; Fan, Xingang; Mahmood, Rezaul; Groves, Chris; Polk, Jason S.; Yan, Jun

2018-03-01

Due to their particular physiographic, geomorphic, soil cover, and complex surface-subsurface hydrologic conditions, karst regions produce distinct land-atmosphere interactions. It has been found that floods and droughts over karst regions can be more pronounced than those in non-karst regions following a given rainfall event. Five convective weather events are simulated using the Weather Research and Forecasting model to explore the potential impacts of land-surface conditions on weather simulations over karst regions. Since no existing weather or climate model has the ability to represent karst landscapes, simulation experiments in this exploratory study consist of a control (default land-cover/soil types) and three land-surface conditions, including barren ground, forest, and sandy soils over the karst areas, which mimic certain karst characteristics. Results from sensitivity experiments are compared with the control simulation, as well as with the National Centers for Environmental Prediction multi-sensor precipitation analysis Stage-IV data, and near-surface atmospheric observations. Mesoscale features of surface energy partition, surface water and energy exchange, the resulting surface-air temperature and humidity, and low-level instability and convective energy are analyzed to investigate the potential land-surface impact on weather over karst regions. We conclude that: (1) barren ground used over karst regions has a pronounced effect on the overall simulation of precipitation. Barren ground provides the overall lowest root-mean-square errors and bias scores in precipitation over the peak-rain periods. Contingency table-based equitable threat and frequency bias scores suggest that the barren and forest experiments are more successful in simulating light to moderate rainfall. Variables dependent on local surface conditions show stronger contrasts between karst and non-karst regions than variables dominated by large-scale synoptic systems; (2) significant sensitivity responses are found over the karst regions, including pronounced warming and cooling effects on the near-surface atmosphere from barren and forested land cover, respectively; (3) the barren ground in the karst regions provides conditions favourable for convective development under certain conditions. Therefore, it is suggested that karst and non-karst landscapes should be distinguished, and their physical processes should be considered for future model development.

Nucleate boiling performance on nano/microstructures with different wetting surfaces

PubMed Central

2012-01-01

A study of nucleate boiling phenomena on nano/microstructures is a very basic and useful study with a view to the potential application of modified surfaces as heating surfaces in a number of fields. We present a detailed study of boiling experiments on fabricated nano/microstructured surfaces used as heating surfaces under atmospheric conditions, employing identical nanostructures with two different wettabilities (silicon-oxidized and Teflon-coated). Consequently, enhancements of both boiling heat transfer (BHT) and critical heat flux (CHF) are demonstrated in the nano/microstructures, independent of their wettability. However, the increment of BHT and CHF on each of the different wetting surfaces depended on the wetting characteristics of heating surfaces. The effect of water penetration in the surface structures by capillary phenomena is suggested as a plausible mechanism for the enhanced CHF on the nano/microstructures regardless of the wettability of the surfaces in atmospheric condition. This is supported by comparing bubble shapes generated in actual boiling experiments and dynamic contact angles under atmospheric conditions on Teflon-coated nano/microstructured surfaces. PMID:22559173

The Influence of As-Built Surface Conditions on Mechanical Properties of Ti-6Al-4V Additively Manufactured by Selective Electron Beam Melting

NASA Astrophysics Data System (ADS)

Sun, Y. Y.; Gulizia, S.; Oh, C. H.; Fraser, D.; Leary, M.; Yang, Y. F.; Qian, M.

2016-03-01

Achieving a high surface finish is a major challenge for most current metal additive manufacturing processes. We report the first quantitative study of the influence of as-built surface conditions on the tensile properties of Ti-6Al-4V produced by selective electron beam melting (SEBM) in order to better understand the SEBM process. Tensile ductility was doubled along with noticeable improvements in tensile strengths after surface modification of the SEBM-fabricated Ti-6Al-4V by chemical etching. The fracture surfaces of tensile specimens with different surface conditions were characterised and correlated with the tensile properties obtained. The removal of a 650- μm-thick surface layer by chemical etching was shown to be necessary to eliminate the detrimental influence of surface defects on mechanical properties. The experimental results and analyses underline the necessity to modify the surfaces of SEBM-fabricated components for structural applications, particularly for those components which contain complex internal concave and convex surfaces and channels.

Vacancy Transport and Interactions on Metal Surfaces

DTIC Science & Technology

2014-03-06

prevent obtaining systematical pictures with atomic scale resolution. Thus the experiments on adatom and mono -vacancy surface diffusion on Ag(110) were...vacuum conditions with atomic scale resolution with Scanning Tunneling Microscope (STM) and Field Ion Microscope (FIM). For each investigated material...experimental conditions for creation of surface vacancies on Au(100) has been determined and observations of surface diffusion of mono vacancies has been

Wetlands inform how climate extremes influence surface water expansion and contraction

USGS Publications Warehouse

Vanderhoof, Melanie; Lane, Charles R.; McManus, Michael L.; Alexander, Laurie C.; Christensen, Jay R.

2018-01-01

Effective monitoring and prediction of flood and drought events requires an improved understanding of how and why surface water expansion and contraction in response to climate varies across space. This paper sought to (1) quantify how interannual patterns of surface water expansion and contraction vary spatially across the Prairie Pothole Region (PPR) and adjacent Northern Prairie (NP) in the United States, and (2) explore how landscape characteristics influence the relationship between climate inputs and surface water dynamics. Due to differences in glacial history, the PPR and NP show distinct patterns in regards to drainage development and wetland density, together providing a diversity of conditions to examine surface water dynamics. We used Landsat imagery to characterize variability in surface water extent across 11 Landsat path/rows representing the PPR and NP (images spanned 1985–2015). The PPR not only experienced a 2.6-fold greater surface water extent under median conditions relative to the NP, but also showed a 3.4-fold greater change in surface water extent between drought and deluge conditions. The relationship between surface water extent and accumulated water availability (precipitation minus potential evapotranspiration) was quantified per watershed and statistically related to variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). To investigate the influence stream connectivity has on the rate at which surface water leaves a given location, we modeled stream-connected and stream-disconnected surface water separately. Stream-connected surface water showed a greater expansion with wetter climatic conditions in landscapes with greater total wetland area, but lower total wetland density. Disconnected surface water showed a greater expansion with wetter climatic conditions in landscapes with higher wetland density, lower infiltration and less anthropogenic drainage. From these findings, we can expect that shifts in precipitation and evaporative demand will have uneven effects on surface water quantity. Accurate predictions regarding the effect of climate change on surface water quantity will require consideration of hydrology-related landscape characteristics including wetland storage and arrangement.

Effects of visual feedback with a mirror on balance ability in patients with stroke.

PubMed

In, Tae-Sung; Cha, Yu-Ri; Jung, Jin-Hwa; Jung, Kyoung-Sim

2016-01-01

[Purpose] This study aimed to examine the effects of a visual feedback obtained from a mirror on balance ability during quiet standing in patients with stroke. [Subjects] Fifteen patients with stroke (9 males, 6 females) enrolled in the study. [Methods] Experimental trials (duration, 20s) included three visual conditions (eyes closed, eyes open, and mirror feedback) and two support surface conditions (stable, and unstable). Center of pressure (COP) displacements in the mediolateral and anteroposterior directions were recorded using a force platform. [Results] No effect of condition was observed along all directions on the stable surface. An effect of condition was observed on the unstable surface, with a smaller mediolateral COP distance in the mirror feedback as compared to the other two conditions. Similar results were observed for the COP speed. [Conclusion] Visual feedback from a mirror is beneficial for improving balance ability during quiet standing on an unstable surface in patients with stroke.

Indium antimonide crystal growth experiment M562. [Skylab weightless conditions

NASA Technical Reports Server (NTRS)

Gatos, H. C.; Witt, A. F.

1974-01-01

It was established that ideal diffusion controlled steady state conditions, never accomplished on earth, were achieved during the growth of Te-doped InSb crystals in Skylab. Surface tension effects led to nonwetting conditions under which free surface solidification took place in confined geometry. It was further found that, under forced contact conditions, surface tension effects led to the formation of surface ridges (not previously observed on earth) which isolated the growth system from its container. In addition, it was possible, for the first time, to identify unambiguously: the origin of segregation discontinuities associated with facet growth, the mode of nucleation and propagation of rotational twin boundaries, and the specific effect of mechanical-shock perturbations on segregation. The results obtained prove the advantageous conditions provided by outer space. Thus, fundamental data on solidification thought to be unattainable because of gravity-induced interference on earth are now within reach.

Climate and the equilibrium state of land surface hydrology parameterizations

NASA Technical Reports Server (NTRS)

Entekhabi, Dara; Eagleson, Peter S.

1991-01-01

For given climatic rates of precipitation and potential evaporation, the land surface hydrology parameterizations of atmospheric general circulation models will maintain soil-water storage conditions that balance the moisture input and output. The surface relative soil saturation for such climatic conditions serves as a measure of the land surface parameterization state under a given forcing. The equilibrium value of this variable for alternate parameterizations of land surface hydrology are determined as a function of climate and the sensitivity of the surface to shifts and changes in climatic forcing are estimated.

Derivation and application of a class of generalized boundary conditions

NASA Technical Reports Server (NTRS)

Senior, Thomas B. A.; Volakis, John L.

1989-01-01

Boundary conditions involving higher order derivatives are presented for simulating surfaces whose reflection coefficients are known analytically, numerically, or experimentally. Procedures for determining the coefficients of the derivatives are discussed, along with the effect of displacing the surface where the boundary conditions are applied. Provided the coefficients satisfy a duality relation, equivalent forms of the boundary conditions involving tangential field components are deduced, and these provide the natural extension to nonplanar surfaces. As an illustration, the simulation of metal-backed uniform and three-layer dielectric coatings is given. It is shown that fourth order conditions are capable of providing an accurate simulation for uniform coating at least a quarter of a wavelength in thickness.

Analysis of dispersion and attenuation of surface waves in poroelastic media in the exploration-seismic frequency band

USGS Publications Warehouse

Zhang, Y.; Xu, Y.; Xia, J.

2011-01-01

We analyse dispersion and attenuation of surface waves at free surfaces of possible vacuum/poroelastic media: permeable-'open pore', impermeable-'closed pore' and partially permeable boundaries, which have not been previously reported in detail by researchers, under different surface-permeable, viscous-damping, elastic and fluid-flowing conditions. Our discussion is focused on their characteristics in the exploration-seismic frequency band (a few through 200 Hz) for near-surface applications. We find two surface-wave modes exist, R1 waves for all conditions, and R2 waves for closed-pore and partially permeable conditions. For R1 waves, velocities disperse most under partially permeable conditions and least under the open-pore condition. High-coupling damping coefficients move the main dispersion frequency range to high frequencies. There is an f1 frequency dependence as a constant-Q model for attenuation at high frequencies. R1 waves for the open pore are most sensitive to elastic modulus variation, but least sensitive to tortuosities variation. R1 waves for partially permeable surface radiate as non-physical waves (Im(k) < 0) at low frequencies. For R2 waves, velocities are slightly lower than the bulk slow P2 waves. At low frequencies, both velocity and attenuation are diffusive of f1/2 frequency dependence, as P2 waves. It is found that for partially permeable surfaces, the attenuation displays -f1 frequency dependence as frequency increasing. High surface permeability, low-coupling damping coefficients, low Poisson's ratios, and low tortuosities increase the slope of the -f1 dependence. When the attenuation coefficients reach 0, R2 waves for partially permeable surface begin to radiate as non-physical waves. ?? 2011 The Authors Geophysical Journal International ?? 2011 RAS.

Design of an Operando Positron Annihilation Gamma Spectrometer (OPAGS)

NASA Astrophysics Data System (ADS)

Satyal, Suman; Shastry, Kartik; Kalaskar, Sushant; Lim, Larry; Joglekar, Vibek; Weiss, Alexander

2009-10-01

Surface properties measured under UHV conditions cannot be extended to surfaces interacting with gases under realistic pressures due to surface reconstruction and other strong perturbations of the surface. Many surface probing techniques used till now have required UHV conditions to avoid data loss due to scattering of outgoing particles. Here we describe the design of an Operando Positron Annihilation Gamma Spectrometer (OPAGS) currently under construction at the University of Texas at Arlington. The new system will be capable of obtaining surface and defect specific chemical and charge state information from surfaces under realistic pressures. Differential pumping will be used to maintain the sample in a gas environment while the rest of the beam is under UHV. The Elemental content of the surface interacting with the gas environment will be determined from the Doppler broadened gamma spectra. This system will also include a time of flight (TOF) positron annihilation induced Auger spectrometer (TOF-PAES) for use in combined annihilation induced Auger and annihilation gamma measurements made under low pressure conditions.

Surface roughness analysis of fiber post conditioning processes.

PubMed

Mazzitelli, C; Ferrari, M; Toledano, M; Osorio, E; Monticelli, F; Osorio, R

2008-02-01

The chemo-mechanical surface treatment of fiber posts increases their bonding properties. The combined use of atomic force and confocal microscopy allows for the assessment and quantification of the changes on surface roughness that justify this behavior. Quartz fiber posts were conditioned with different chemicals, as well as by sandblasting, and by an industrial silicate/silane coating. We analyzed post surfaces by atomic force microscopy, recording average roughness (R(a)) measurements of fibers and resin matrix. A confocal image profiler allowed for the quantitative assessment of the average superficial roughness (R(a)). Hydrofluoric acid, potassium permanganate, sodium ethoxide, and sandblasting increased post surface roughness. Modifications of the epoxy resin matrix occurred after the surface pre-treatments. Hydrofluoric acid affected the superficial texture of quartz fibers. Surface-conditioning procedures that selectively react with the epoxy-resin matrix of the fiber post enhance roughness and improve the surface area available for adhesion by creating micro-retentive spaces without affecting the post's inner structure.

Correlation between the plasma characteristics and the surface chemistry of plasma-treated polymers through partial least-squares analysis.

PubMed

Mavadat, Maryam; Ghasemzadeh-Barvarz, Massoud; Turgeon, Stéphane; Duchesne, Carl; Laroche, Gaétan

2013-12-23

We investigated the effect of various plasma parameters (relative density of atomic N and H, plasma temperature, and vibrational temperature) and process conditions (pressure and H2/(N2 + H2) ratio) on the chemical composition of modified poly(tetrafluoroethylene) (PTFE). The plasma parameters were measured by means of near-infrared (NIR) and UV-visible emission spectroscopy with and without actinometry. The process conditions of the N2-H2 microwave discharges were set at various pressures ranging from 100 to 2000 mTorr and H2/(N2+H2) gas mixture ratios between 0 and 0.4. The surface chemical composition of the modified polymers was determined by X-ray photoelectron spectroscopy (XPS). A mathematical model was constructed using the partial least-squares regression algorithm to correlate the plasma information (process condition and plasma parameters as determined by emission spectroscopy) with the modified surface characteristics. To construct the model, a set of data input variables containing process conditions and plasma parameters were generated, as well as a response matrix containing the surface composition of the polymer. This model was used to predict the composition of PTFE surfaces subjected to N2-H2 plasma treatment. Contrary to what is generally accepted in the literature, the present data demonstrate that hydrogen is not directly involved in the defluorination of the surface but rather produces atomic nitrogen and/or NH radicals that are shown to be at the origin of fluorine atom removal from the polymer surface. The results show that process conditions alone do not suffice in predicting the surface chemical composition and that the plasma characteristics, which cannot be easily correlated with these conditions, should be considered. Process optimization and control would benefit from plasma diagnostics, particularly infrared emission spectroscopy.

Investigating the photostability of carboxylic acids exposed to Mars surface ultraviolet radiation conditions.

PubMed

Stalport, F; Coll, P; Szopa, C; Cottin, H; Raulin, F

2009-01-01

The detection and identification of organic molecules on Mars are of primary importance to establish the existence of a possible ancient prebiotic chemistry or even biological activity. The harsh environmental conditions at the surface of Mars could explain why the Viking probes-the only efforts, to date, to search for organics on Mars-detected no organic matter. To investigate the nature, abundance, and stability of organic molecules that could survive such environmental conditions, we developed a series of experiments that simulate martian surface environmental conditions. Here, we present results with regard to the impact of solar UV radiation on various carboxylic acids, such as mellitic acid, which are of astrobiological interest to the study of Mars. Our results show that at least one carboxylic acid, mellitic acid, could produce a resistant compound-benzenehexacarboxylic acid-trianhydride (C(12)O(9))-when exposed to martian surface radiation conditions. The formation of such products could contribute to the presence of organic matter in the martian regolith, which should be considered a primary target for in situ molecular analyses during future surface missions.

Influence of dynamic flow conditions on adsorbed plasma protein corona and surface-induced thrombus generation on antifouling brushes.

PubMed

Yu, Kai; Andruschak, Paula; Yeh, Han Hung; Grecov, Dana; Kizhakkedathu, Jayachandran N

2018-06-01

The information regarding the nature of protein corona (and its changes) and cell binding on biomaterial surface under dynamic conditions is critical to dissect the mechanism of surface-induced thrombosis. In this manuscript, we investigated the nature of protein corona and blood cell binding in heparinized recalcified human plasma, platelet rich plasma and whole blood on three highly hydrophilic antifouling polymer brushes, (poly(N, N-dimethylacrylamide) (PDMA), poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly[N-(2-hydroxypropyl) methacrylamide] (PHPMA) using an in vitro blood loop model at comparable arterial and venous flow, and static conditions. A fluid dynamics model was used initially to better understand the resulting flow patterns in a vertical channel containing the substrates to arrive at the placement of the substrates within the blood loop. The protein binding on the brush modified substrates was determined using ellipsometry, fluorescence microscopy and the nature of the protein corona was investigated using mass spectrometry based proteomics. The flow elevated fouling on brush coated surface from blood. The extent of plasma protein adsorption and platelet adhesion onto PDMA brush was lower than other surfaces in both static and flow conditions. The profiles of adsorbed protein corona showed strong dependence on the test conditions (static vs. flow), and the chemistry of the polymer brushes. Specially, the PDMA brush under flow conditions was more enriched with coagulation proteins, complement proteins, vitronectin and fibronectin but was less enriched with serum albumin. Apolipoprotein B-100 and complement proteins were the most abundant proteins seen on PMPC and PHPMA surfaces under both flow and static conditions, respectively. Unlike PDMA brush, the flow conditions did not affect the composition of protein corona on PMPC and PHPMA brushes. The nature of the protein corona formed in flow conditions influenced the platelet and red blood cell binding. The dependence of shear stress on platelet adhesion from platelet rich plasma and whole blood highlights the contribution of red blood cells in enhancing platelet adhesion on the surface under high shear condition. Copyright © 2018 Elsevier Ltd. All rights reserved.

Size-Selective Modes of Aeolian Transport on Earth and Mars

NASA Astrophysics Data System (ADS)

Swann, C.; Ewing, R. C.; Sherman, D. J.; McLean, C. J.

2016-12-01

Aeolian sand transport is a dominant driver of surface change and dust emission on Mars. Estimates of aeolian sand transport on Earth and Mars rely on terrestrial transport models that do not differentiate between transport modes (e.g., creep vs. saltation), which limits estimates of the critical threshold for transport and the total sand flux during a transport event. A gap remains in understanding how the different modes contribute to the total sand flux. Experiments conducted at the MARtian Surface WInd Tunnel separated modes of transport for uniform and mixed grain size surfaces at Earth and Martian atmospheric pressures. Crushed walnut shells with a density of 1.0 gm/cm3 were used. Experiments resolved grain size distributions for creeping and saltating grains over 3 uniform surfaces, U1, U2, and U3, with median grain sizes of 308 µm, 721 µm, and 1294 µm, and a mixed grain size surface, M1, with median grain sizes of 519 µm. A mesh trap located 5 cm above the test bed and a surface creep trap were deployed to capture particles moving as saltation and creep. Grains that entered the creep trap at angles ≥ 75° were categorized as moving in creep mode only. Only U1 and M1 surfaces captured enough surface creep at both Earth and Mars pressure for statistically significant grain size analysis. Our experiments show that size selective transport differs between Earth and Mars conditions. The median grain size of particles moving in creep for both uniform and mixed surfaces are larger under Earth conditions. (U1Earth = 385 µm vs. U1Mars = 355 µm; M1Earth = 762 vs. M1Mars = 697 µm ). However, particles moving in saltation were larger under Mars conditions (U1Earth = 282 µm; U1Mars = 309 µm; M1Earth = 347 µm; M1Mars = 454 µm ). Similar to terrestrial experiments, the median size of surface creep is larger than the median grain size of saltation. Median sizes of U1, U2, U3 at Mars conditions for creep was 355 µm, 774 µm and 1574 µm. Saltation at Mars conditions over the same surfaces was 309 µm, 695 µm and 1398 µm. For the mixed surfaces under Earth and Mars conditions, the size selection process resulted the formation of incipient ripples that migrated over a finer substrate. Determining the modes of transport under Martian conditions refines our understanding of the development of deflationary surfaces and bed forms.

Observations of the convective plume of a lake under cold-air advective conditions

NASA Technical Reports Server (NTRS)

Bill, R. G., Jr.; Sutherland, R. A.; Bartholic, J. F.; Chen, E.

1978-01-01

Moderating effects of Lake Apopka, Florida, on downwind surface temperatures were evaluated under cold-air advective conditions. Point temperature measurements north and south of the lake and data obtained from a thermal scanner flown at 1.6 km indicate that surface temperatures directly downwind may be higher than surrounding surface temperatures by as much as 5 C under conditions of moderate winds (about 4 m/s). No substantial temperature effects were observed with surface wind speed less than 1 m/s. Fluxes of sensible and latent heat from Lake Apopka were calculated from measurements of lake temperature, net radiation, relative humidity, and air temperature above the lake. Bulk transfer coefficients and the Bowen ratio were calculated and found to be in agreement with reported data for nonadvective conditions.

Surface modification of EPDM rubber by plasma treatment.

PubMed

Grythe, Kai Frode; Hansen, Finn Knut

2006-07-04

The effect of argon, oxygen, and nitrogen plasma treatment of solvent cast EPDM rubber films has been investigated by means of atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and surface energy measurements. Plasma treatment leads to changes in the surface energy from 25 to 70 mN/m. Treatment conditions influenced both the changes in surface energy and the stability, and it became more difficult to obtain good contact angle measurements after longer (> ca. 4 min) treatment times, probably because of an increasingly uneven surface structure. XPS analyses revealed that up to 20 at. % oxygen can be easily incorporated and that variations of approximately 5% can be controlled by the plasma conditions. Oxygen was mainly found in hydroxyl groups, but also as carbonyl and carboxyl. XPS analyses showed more stable surfaces than expected from contact angles, probably because XPS analysis is less surface sensitive than contact angle measurements. AFM measurements revealed different surface structures with the three gases. The surface roughness increased generally with treatment time, and dramatic changes could be observed at longer times. At short times, surface energy changes were much faster than the changes in surface structure, showing that plasma treatment conditions can be utilized to tailor both surface energies and surface structure of EPDM rubber.

Extent of fungal growth on fiberglass duct liners with and without biocides under challenging environmental conditions.

PubMed

Samimi, Behzad S; Ross, Kristen

2003-03-01

Eight brands of fiberglass duct liners, including three that contained biocides, were exposed to challenging environmental conditions that would promote fungal growth. Twenty-four rectangular sheet metal ducts in three groups of eight ducts per group were lined with the eight selected liners. Each group of ducts was exposed to one of the three test conditions within an environmental chamber for a period of 15 days. These conditions were a) 75 percent RH, b) 75 percent RH plus water spray, c) 75 percent RH plus dry nutrient, and d) 75 percent RH plus water plus nutrient. Viable spores of Aspergillus niger were aerosolized into each duct as seed. On the 16th day, air and surface samples for fungal spores were collected from inside ducts. The results of air sampling using N6 sampler and visual inspection indicated that two out of three biocide-containing liners, Permacote and Toughgard, inhibited fungal growth but only under condition A. The third biocide-containing liner, Aeroflex Plus, was effective even when it was wet (conditions A and B). All three biocide-containing liners failed to inhibit fungal growth under conditions C and D. Among the five other types of liners that did not contain biocides, ATCO Flex with a smooth Mylar coating was more preferable, exhibiting lower fungal activity during conditions A, B, and C. All liners failed under condition D when nutrient and water were added together. Surface sampling using adhesive tape failed to produce representative results, apparently due to rough/porous surface of duct liners. It was concluded that duct liners with biocide treatment could be less promoting to microbial growth under high humidity as long as their surfaces remain clean and water-free. A liner with an impermeable and smooth surface seems to be less subject to microbial growth under most conditions than biocide-containing liners having porous and/or rough surfaces.

Miscut dependent surface evolution in the process of N-polar GaN(000 1 bar) growth under N-rich condition

NASA Astrophysics Data System (ADS)

Krzyżewski, Filip; Załuska-Kotur, Magdalena A.; Turski, Henryk; Sawicka, Marta; Skierbiszewski, Czesław

2017-01-01

The evolution of surface morphology during the growth of N-polar (000 1 bar) GaN under N-rich conditions is studied by kinetic Monte Carlo (kMC) simulations for two substrates miscuts 2° and 4°. The results are compared with experimentally observed surface morphologies of (000 1 bar) GaN layers grown by plasma-assisted molecular beam epitaxy. The proposed kMC two-component model of GaN(000 1 bar) surface where both types of atoms, nitrogen and gallium, attach to the surface and diffuse independently shows that at relatively high rates of the step flow (miscut angle < 2 °) the low mobility of gallium adatoms causes surface instabilities and leads to experimentally observed roughening while for low rates of the step flow (miscut 4°), smooth surface can be obtained. In the presence of almost immobile nitrogen atoms under N-rich conditions crystal growth is realized by the process of two-dimensional island nucleation and coalescence. Larger crystal miscut, lower growth rate or higher temperature results in similar effect of the surface smoothening. We show that the surface also smoothens for the growth conditions with very high N-excess. In the presence of large number of nitrogen atoms the mobility of gallium atoms changes locally thus providing easier coalescence of separated island.

Mars surface radiation exposure for solar maximum conditions and 1989 solar proton events

NASA Technical Reports Server (NTRS)

Simonsen, Lisa C.; Nealy, John E.

1992-01-01

The Langley heavy-ion/nucleon transport code, HZETRN, and the high-energy nucleon transport code, BRYNTRN, are used to predict the propagation of galactic cosmic rays (GCR's) and solar flare protons through the carbon dioxide atmosphere of Mars. Particle fluences and the resulting doses are estimated on the surface of Mars for GCR's during solar maximum conditions and the Aug., Sep., and Oct. 1989 solar proton events. These results extend previously calculated surface estimates for GCR's at solar minimum conditions and the Feb. 1956, Nov. 1960, and Aug. 1972 solar proton events. Surface doses are estimated with both a low-density and a high-density carbon dioxide model of the atmosphere for altitudes of 0, 4, 8, and 12 km above the surface. A solar modulation function is incorporated to estimate the GCR dose variation between solar minimum and maximum conditions over the 11-year solar cycle. By using current Mars mission scenarios, doses to the skin, eye, and blood-forming organs are predicted for short- and long-duration stay times on the Martian surface throughout the solar cycle.

First-principles study of native defects in bulk Sm2CuO4 and its (001) surface structure

NASA Astrophysics Data System (ADS)

Zheng, Fubao; Zhang, Qinfang; Meng, Qiangqiang; Wang, Baolin; Song, Fengqi; Yunoki, Seiji; Wang, Guanghou

2018-04-01

Using the first-principles calculations based on the density functional theory, we have studied the bulk defect formation and surface structures of Sm2CuO4. To ensure the accuracy of calculations, the spin order of Cu atoms is rechecked and it is the well-known nearest-neighbor antiferromagnetic ground state, which can be attributed to the hole-mediated superexchange through the strong pdσ hybridization interaction between Cu dx2-y2 electron and the neighboring oxygen px (or py) electron. Under each present experimental condition, the Sm vacancy has a very high formation energy and is unlikely to be stable. The Cu vacancy is a shallow acceptor, which is preferred under O-rich conditions, whereas the O vacancy is a donor and energetically favorable under O-poor conditions. To construct its (001) surface structure, CuOO, CuO, and Cu terminated surfaces are found to be most favorable under different experimental conditions. The stable surface structures are always accompanied by significant surface atomic reconstructions and electron charge redistribution, which are intimately correlated to each other.

New boundary conditions for fluid interaction with hydrophobic surface

NASA Astrophysics Data System (ADS)

Pochylý, František; Fialová, Simona; Havlásek, Michal

2018-06-01

Solution of both laminar and turbulent flow with consideration of hydrophobic surface is based on the original Navier assumption that the shear stress on the hydrophobic surface is directly proportional to the slipping velocity. In the previous work a laminar flow analysis with different boundary conditions was performed. The shear stress value on the tube walls directly depends on the pressure gradient. In the solution of the turbulent flow by the k-ɛ model, the occurrence of the fluctuation components of velocity on the hydrophobic surface is considered. The fluctuation components of the velocity affect the size of the adhesive forces. We assume that the boundary condition for ɛ depending on the velocity gradients will not need to be changed. When the liquid slips over the surface, non-zero fluctuation velocity components occur in the turbulent flow. These determine the non-zero value of the turbulent kinetic energy K. In addition, the fluctuation velocity components also influence the value of the adhesive forces, so it is necessary to include these in the formulation of new boundary conditions for turbulent flow on the hydrophobic surface.

Observations of the microclimate of a lake under cold air advective conditions

NASA Technical Reports Server (NTRS)

Bill, R. G., Jr.; Sutherland, R. A.; Bartholic, J. F.

1977-01-01

The moderating effects of Lake Apopka, Florida, on downwind surface temperatures were evaluated under cold air advective conditions. Point temperature measurements north and south of the lake and data obtained from the NOAA satellite and a thermal scanner flown at 1.6 km, indicate that, under conditions of moderate winds (approximately 4m/sec), surface temperatures directly downwind may be higher than surrounding surface temperatures by as much as 5 C. With surface wind speed less than 1m/sec, no substantial temperature effects were observed. Results of this study are being used in land use planning, lake level control and in agriculture for selecting planting sites.

Condition of Mechanical Equilibrium at the Phase Interface with Arbitrary Geometry

NASA Astrophysics Data System (ADS)

Zubkov, V. V.; Zubkova, A. V.

2017-09-01

The authors produced an expression for the mechanical equilibrium condition at the phase interface within the force definition of surface tension. This equilibrium condition is the most general one from the mathematical standpoint and takes into account the three-dimensional aspect of surface tension. Furthermore, the formula produced allows describing equilibrium on the fractal surface of the interface. The authors used the fractional integral model of fractal distribution and took the fractional order integrals over Euclidean space instead of integrating over the fractal set.

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

Cobb, M. A.; Dockter, R. E.

The permeability of ground surfaces within the U.S. Department of Energy’s (DOE) Hanford Site strongly influences boundary conditions when simulating the movement of groundwater using the Subsurface Transport Over Multiple Phases model. To conduct site-wide modeling of cumulative impacts to groundwater from past, current, and future waste management activities, a site-wide assessment of the permeability of surface conditions is needed. The surface condition of the vast majority of the Hanford Site has been and continues to be native soils vegetated with dryland grasses and shrubs.

Atomic force microscopy of lead iodide crystal surfaces

NASA Astrophysics Data System (ADS)

George, M. A.; Azoulay, M.; Jayatirtha, H. N.; Biao, Y.; Burger, A.; Collins, W. E.; Silberman, E.

1994-03-01

Atomic force microscopy (AFM) was used to characterize the surface of lead iodide crystals. The high vapor pressure of lead iodide prohibits the use of traditional high resolution surface study techniques that require high vacuum conditions. AFM was used to image numerous insulating surface in various ambients, with very little sample preparation techniques needed. Freshly cleaved and modified surfaces, including, chemical and vacuum etched, and air aged surfaces, were examined. Both intrinsic and induced defects were imaged with high resolution. The results were compared to a similar AFM study of mercuric iodide surfaces and it was found that, at ambient conditions, lead iodide is significantly more stable than mercuric iodide.

The influence of land surface properties on Sahel climate. Part 1: Desertification

NASA Technical Reports Server (NTRS)

Xue, Yongkang; Shukla, Jagadish

1993-01-01

This is a general circulation model sensitivity study of the physical mechanisms of the effects of desertification on the Sahel drought. The model vegetation types were changed in the prescribed desertification area, which led to changes in the surface characteristics. The model was integrated for three months (June, July, August) with climatological surface conditions (control) and desertification conditions (anomaly) to examine the summer season response to the changed surface conditions. The control and anomaly experiments consisted of five pairs of integrations with different initial conditions and/or sea surface temperature boundary conditions. In the desertification experiment, the moisture flux convergence and rainfall were reduced in the test area and increased to the immediate south of this area. The simulated anomaly dipole pattern was similar to the observed African drought patterns in which the axis of the maximum rainfall shifts to the south. The circulation changes in the desertification experiment were consistent with those observed during sub-Saharan dry years. The tropical easterly jet was weaker and the African easterly jet was stronger than normal. Further, in agreement with the observations, the easterly wave disturbances were reduced in intensity but not in number. Descending motion dominated the desertification area. The surface energy budget and hydrological cycle were also changed substantially in the anomaly experiment.

Numerical Model of the Hoosic River Flood-Control Channel, Adams, MA

DTIC Science & Technology

2010-02-01

The model was then used to evaluate the flow conditions associated with the as-built channel configuration. The existing channel conditions were then...end as part of a channel restoration project. The model was to determine if restoration alterations would change water- surface elevations associated ...water-surface elevations associated with the initial design and construction. After as-built flow conditions were established, flow conditions

Subjective assessments of floor slipperiness before and after walk under two lighting conditions.

PubMed

Li, Kai Way; Zhao, Caijun; Peng, Lu; Liu, Ai-Qun

2018-06-01

A gait experiment was performed. The participants were tested under shoes, floors, surface and lighting conditions. They gave floor slipperiness ratings before and after a gait trial. The perceived sense of slip (PSOS) was collected. It was found that the perceived floor slipperiness (PFS) before walking was affected significantly by the lighting, floor and surface conditions. Relative low PFS values were recorded under wet and detergent-contaminated conditions in the normal daylight condition as compared with those in the dimmed condition. The PFS after the gait was significantly affected by the floor and surface conditions. The PSOS was highly correlated with the PFS after trial. The regression analyses results indicated that both the coefficient of friction (COF) of the floor and lighting were primary predictors of the PFS before a gait. The COF and walking speed were the primary predictors of the PFS after a gait.

Simulations of chemical vapor deposition diamond film growth using a kinetic Monte Carlo model and two-dimensional models of microwave plasma and hot filament chemical vapor deposition reactors

NASA Astrophysics Data System (ADS)

May, P. W.; Harvey, J. N.; Allan, N. L.; Richley, J. C.; Mankelevich, Yu. A.

2010-12-01

A one-dimensional kinetic Monte Carlo (KMC) model has been developed to simulate the chemical vapor deposition of a diamond (100) surface under conditions used to grow single-crystal diamond (SCD), microcrystalline diamond (MCD), nanocrystalline diamond (NCD), and ultrananocrystalline diamond (UNCD) films. The model considers adsorption, etching/desorption, lattice incorporation and surface migration but not defect formation or renucleation processes. Two methods have been devised for estimation of the gas phase concentrations of species at the growing diamond surface, and are used to determine adsorption rates for C1Hx hydrocarbons for the different conditions. The rate of migration of adsorbed carbon species is governed by the availability of neighboring radical sites, which, in turn, depend upon the rates of H abstraction and of surface-radical migration. The KMC model predicts growth rates and surface roughness for each of diamond types consistent with experiment. In the absence of defect formation and renucleation the average surface diffusion length, ℓ, is a key parameter controlling surface morphology. When ℓ <2, surface migration is limited by the lack of availability of surface radical sites, and the migrating surface species simply hop back and forth between two adjacent sites but do not travel far beyond their initial adsorption site. Thus, Eley-Rideal processes dominate the growth, leading to the rough surfaces seen in NCD and UNCD. The maximum or "intrinsic" surface roughness occurs for nominally zero-migration conditions (ℓ =0) with an rms value of approximately five carbon atoms. Conversely, when migration occurs over greater distances (ℓ >2), Langmuir-Hinshelwood processes dominate the growth producing the smoother surfaces of MCD and SCD. By extrapolation, we predict that atomically smooth surfaces over large areas should occur once migrating species can travel approximately five sites (ℓ ˜5). β-scission processes are found to be unimportant for MCD and SCD growth conditions, but can remove up to 5% of the adsorbing carbon for NCD and UNCD growth. C1Hx insertion reactions also contribute <1% to the growth for nearly all conditions, while C2Hx (x <2) insertion reactions are negligible due their very low concentrations at the surface. Finally, the predictions for growth rate and morphology for UNCD deposition in a microwave system were found to be anomalous compared to those for all the other growth conditions, suggesting that carbonaceous particulates created in these plasmas may significantly affect the gas chemistry.

Footwear and Foam Surface Alter Gait Initiation of Typical Subjects

PubMed Central

Vieira, Marcus Fraga; Sacco, Isabel de Camargo Neves; Nora, Fernanda Grazielle da Silva Azevedo; Rosenbaum, Dieter; Lobo da Costa, Paula Hentschel

2015-01-01

Gait initiation is the task commonly used to investigate the anticipatory postural adjustments necessary to begin a new gait cycle from the standing position. In this study, we analyzed whether and how foot-floor interface characteristics influence the gait initiation process. For this purpose, 25 undergraduate students were evaluated while performing a gait initiation task in three experimental conditions: barefoot on a hard surface (barefoot condition), barefoot on a soft surface (foam condition), and shod on a hard surface (shod condition). Two force plates were used to acquire ground reaction forces and moments for each foot separately. A statistical parametric mapping (SPM) analysis was performed in COP time series. We compared the anterior-posterior (AP) and medial-lateral (ML) resultant center of pressure (COP) paths and average velocities, the force peaks under the right and left foot, and the COP integral x force impulse for three different phases: the anticipatory postural adjustment (APA) phase (Phase 1), the swing-foot unloading phase (Phase 2), and the support-foot unloading phase (Phase 3). In Phase 1, significantly smaller ML COP paths and velocities were found for the shod condition compared to the barefoot and foam conditions. Significantly smaller ML COP paths were also found in Phase 2 for the shod condition compared to the barefoot and foam conditions. In Phase 3, increased AP COP velocities were found for the shod condition compared to the barefoot and foam conditions. SPM analysis revealed significant differences for vector COP time series in the shod condition compared to the barefoot and foam conditions. The foam condition limited the impulse-generating capacity of COP shift and produced smaller ML force peaks, resulting in limitations to body-weight transfer from the swing to the support foot. The results suggest that footwear and a soft surface affect COP and impose certain features of gait initiation, especially in the ML direction of Phase 1. PMID:26270323

Three-dimensional unsteady lifting surface theory in the subsonic range

NASA Technical Reports Server (NTRS)

Kuessner, H. G.

1985-01-01

The methods of the unsteady lifting surface theory are surveyed. Linearized Euler's equations are simplified by means of a Galileo-Lorentz transformation and a Laplace transformation so that the time and the compressibility of the fluid are limited to two constants. The solutions to this simplified problem are represented as integrals with a differential nucleus; these results in tolerance conditions, for which any exact solution must suffice. It is shown that none of the existing three-dimensional lifting surface theories in subsonic range satisfy these conditions. An oscillating elliptic lifting surface which satisfies the tolerance conditions is calculated through the use of Lame's functions. Numerical examples are calculated for the borderline cases of infinitely stretched elliptic lifting surfaces and of circular lifting surfaces. Out of the harmonic solutions any such temporal changes of the down current are calculated through the use of an inverse Laplace transformation.

Mechanism of supercooled droplet freezing on surfaces.

PubMed

Jung, Stefan; Tiwari, Manish K; Doan, N Vuong; Poulikakos, Dimos

2012-01-10

Understanding ice formation from supercooled water on surfaces is a problem of fundamental importance and general utility. Superhydrophobic surfaces promise to have remarkable 'icephobicity' and low ice adhesion. Here we show that their icephobicity can be rendered ineffective by simple changes in environmental conditions. Through experiments, nucleation theory and heat transfer physics, we establish that humidity and/or the flow of a surrounding gas can fundamentally switch the ice crystallization mechanism, drastically affecting surface icephobicity. Evaporative cooling of the supercooled liquid can engender ice crystallization by homogeneous nucleation at the droplet-free surface as opposed to the expected heterogeneous nucleation at the substrate. The related interplay between droplet roll-off and rapid crystallization is also studied. Overall, we bring a novel perspective to icing and icephobicity, unveiling the strong influence of environmental conditions in addition to the accepted effects of the surface conditions and hydrophobicity.

Dependence of LTX plasma performance on surface conditions as determined by in situ analysis of plasma facing components

NASA Astrophysics Data System (ADS)

Lucia, M.; Kaita, R.; Majeski, R.; Bedoya, F.; Allain, J. P.; Abrams, T.; Bell, R. E.; Boyle, D. P.; Jaworski, M. A.; Schmitt, J. C.

2015-08-01

The Materials Analysis and Particle Probe (MAPP) diagnostic has been implemented on the Lithium Tokamak Experiment (LTX) at PPPL, providing the first in situ X-ray photoelectron spectroscopy (XPS) surface characterization of tokamak plasma facing components (PFCs). MAPP samples were exposed to argon glow discharge conditioning (GDC), lithium evaporations, and hydrogen tokamak discharges inside LTX. Samples were analyzed with XPS, and alterations to surface conditions were correlated against observed LTX plasma performance changes. Argon GDC caused the accumulation of nm-scale metal oxide layers on the PFC surface, which appeared to bury surface carbon and oxygen contamination and thus improve plasma performance. Lithium evaporation led to the rapid formation of a lithium oxide (Li2O) surface; plasma performance was strongly improved for sufficiently thick evaporative coatings. Results indicate that a 5 h argon GDC or a 50 nm evaporative lithium coating will both significantly improve LTX plasma performance.

Evaluation of surface detail reproduction, dimensional stability and gypsum compatibility of monophase polyvinyl-siloxane and polyether elastomeric impression materials under dry and moist conditions

PubMed Central

Vadapalli, Sriharsha Babu; Atluri, Kaleswararao; Putcha, Madhu Sudhan; Kondreddi, Sirisha; Kumar, N. Suman; Tadi, Durga Prasad

2016-01-01

Objectives: This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility. Materials and Methods: Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests. Results: When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P < 0.001). Two conditions also showed significant difference, with moist conditions showing significantly more deviation compared to dry condition (P < 0.001). The results of gypsum compatibility when evaluated with modification of ADA specification no. 19 and by giving grades to the casts for both the groups and under two conditions showed no significant difference statistically. Conclusion: Regarding dimensional stability, both impregum and aquasil performed better in dry condition than in moist; impregum performed better than aquasil in both the conditions. When tested for surface detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry condition, both the materials performed almost equally. In moist condition, aquasil performed significantly better than impregum. Regarding gypsum compatibility according to ADA specification, in dry condition both the materials performed almost equally, and in moist condition aquasil performed better than impregum. When tested by macroscopic evaluation, impregum performed better than aquasil in both the conditions. PMID:27583217

Evaluation of surface detail reproduction, dimensional stability and gypsum compatibility of monophase polyvinyl-siloxane and polyether elastomeric impression materials under dry and moist conditions.

PubMed

Vadapalli, Sriharsha Babu; Atluri, Kaleswararao; Putcha, Madhu Sudhan; Kondreddi, Sirisha; Kumar, N Suman; Tadi, Durga Prasad

2016-01-01

This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility. Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests. When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P < 0.001). Two conditions also showed significant difference, with moist conditions showing significantly more deviation compared to dry condition (P < 0.001). The results of gypsum compatibility when evaluated with modification of ADA specification no. 19 and by giving grades to the casts for both the groups and under two conditions showed no significant difference statistically. Regarding dimensional stability, both impregum and aquasil performed better in dry condition than in moist; impregum performed better than aquasil in both the conditions. When tested for surface detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry condition, both the materials performed almost equally. In moist condition, aquasil performed significantly better than impregum. Regarding gypsum compatibility according to ADA specification, in dry condition both the materials performed almost equally, and in moist condition aquasil performed better than impregum. When tested by macroscopic evaluation, impregum performed better than aquasil in both the conditions.

Impact of soil moisture initialization on boreal summer subseasonal forecasts: mid-latitude surface air temperature and heat wave events

NASA Astrophysics Data System (ADS)

Seo, Eunkyo; Lee, Myong-In; Jeong, Jee-Hoon; Koster, Randal D.; Schubert, Siegfried D.; Kim, Hye-Mi; Kim, Daehyun; Kang, Hyun-Suk; Kim, Hyun-Kyung; MacLachlan, Craig; Scaife, Adam A.

2018-05-01

This study uses a global land-atmosphere coupled model, the land-atmosphere component of the Global Seasonal Forecast System version 5, to quantify the degree to which soil moisture initialization could potentially enhance boreal summer surface air temperature forecast skill. Two sets of hindcast experiments are performed by prescribing the observed sea surface temperature as the boundary condition for a 15-year period (1996-2010). In one set of the hindcast experiments (noINIT), the initial soil moisture conditions are randomly taken from a long-term simulation. In the other set (INIT), the initial soil moisture conditions are taken from an observation-driven offline Land Surface Model (LSM) simulation. The soil moisture conditions from the offline LSM simulation are calibrated using the forecast model statistics to minimize the inconsistency between the LSM and the land-atmosphere coupled model in their mean and variability. Results show a higher boreal summer surface air temperature prediction skill in INIT than in noINIT, demonstrating the potential benefit from an accurate soil moisture initialization. The forecast skill enhancement appears especially in the areas in which the evaporative fraction—the ratio of surface latent heat flux to net surface incoming radiation—is sensitive to soil moisture amount. These areas lie in the transitional regime between humid and arid climates. Examination of the extreme 2003 European and 2010 Russian heat wave events reveal that the regionally anomalous soil moisture conditions during the events played an important role in maintaining the stationary circulation anomalies, especially those near the surface.

40 CFR 53.61 - Test conditions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test conditions. 53.61 Section 53.61... Equivalent Methods for PM2.5 § 53.61 Test conditions. (a) Sampler surface preparation. Internal surfaces of the candidate sampler shall be cleaned and dried prior to performing any Class II sampler test in this...

40 CFR 53.61 - Test conditions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Test conditions. 53.61 Section 53.61... Equivalent Methods for PM2.5 § 53.61 Test conditions. (a) Sampler surface preparation. Internal surfaces of the candidate sampler shall be cleaned and dried prior to performing any Class II sampler test in this...

The use of the virtual source technique in computing scattering from periodic ocean surfaces.

PubMed

Abawi, Ahmad T

2011-08-01

In this paper the virtual source technique is used to compute scattering of a plane wave from a periodic ocean surface. The virtual source technique is a method of imposing boundary conditions using virtual sources, with initially unknown complex amplitudes. These amplitudes are then determined by applying the boundary conditions. The fields due to these virtual sources are given by the environment Green's function. In principle, satisfying boundary conditions on an infinite surface requires an infinite number of sources. In this paper, the periodic nature of the surface is employed to populate a single period of the surface with virtual sources and m surface periods are added to obtain scattering from the entire surface. The use of an accelerated sum formula makes it possible to obtain a convergent sum with relatively small number of terms (∼40). The accuracy of the technique is verified by comparing its results with those obtained using the integral equation technique.

Low visibility operations/surface movement guidance and control system (LVO/SMGCS) chart usability : an examination of flightcrew position awareness in homogeneous 300 ft/75 m RVR conditions

DOT National Transportation Integrated Search

2014-09-01

Two studies were conducted to identify best practices for the design of Low Visibility Operations/Surface Movement Guidance and Control System (LVO/SMGCS) paper charts and flightcrew use of them in extremely low visibility surface conditions. In the ...

Pyroconvection Risk in Australia: Climatological Changes in Atmospheric Stability and Surface Fire Weather Conditions

NASA Astrophysics Data System (ADS)

Dowdy, Andrew J.; Pepler, Acacia

2018-02-01

Extreme wildfires with strong convective processes in their plumes have recently led to disastrous impacts on various regions of the world. The Continuous Haines index (CH) is used in Australia to represent vertical atmospheric stability and humidity measures relating to pyroconvective processes. CH climatology is examined here using reanalysis data from 1979 to 2016, revealing large spatial and seasonal variations throughout Australia. Various measures of severity are investigated, including regionally specific thresholds. CH is combined with near-surface fire weather conditions, as a type of compound event, and is examined in relation to environmental conditions associated with pyroconvection. Significant long-term changes in CH are found for some regions and seasons, with these changes corresponding to changes in near-surface conditions in some cases. In particular, an increased risk of pyroconvection is identified for southeast Australia during spring and summer, due to decreased vertical atmospheric stability and humidity combined with more severe near-surface conditions.

A continuum analysis of chemical nonequilibrium under hypersonic low-density flight conditions

NASA Technical Reports Server (NTRS)

Gupta, R. N.

1986-01-01

Results of employing the continuum model of Navier-Stokes equations under the low-density flight conditions are presented. These results are obtained with chemical nonequilibrium and multicomponent surface slip boundary conditions. The conditions analyzed are those encountered by the nose region of the Space Shuttle Orbiter during reentry. A detailed comparison of the Navier-Stokes (NS) results is made with the viscous shock-layer (VSL) and direct simulation Monte Carlo (DSMC) predictions. With the inclusion of new surface-slip boundary conditions in NS calculations, the surface heat transfer and other flowfield quantities adjacent to the surface are predicted favorably with the DSMC calculations from 75 km to 115 km in altitude. This suggests a much wider practical range for the applicability of Navier-Stokes solutions than previously thought. This is appealing because the continuum (NS and VSL) methods are commonly used to solve the fluid flow problems and are less demanding in terms of computer resource requirements than the noncontinuum (DSMC) methods.

Adaptation of an Antarctic lichen to Martian niche conditions can occur within 34 days

NASA Astrophysics Data System (ADS)

de Vera, Jean-Pierre; Schulze-Makuch, Dirk; Khan, Afshin; Lorek, Andreas; Koncz, Alexander; Möhlmann, Diedrich; Spohn, Tilman

2014-08-01

Stresses occurring on the Martian surface were simulated in a Mars Simulation Chamber (MSC) and included high UV fluxes (Zarnecki and Catling, 2002), low temperatures, low water activity, high atmospheric CO2 concentrations, and an atmospheric pressure of about 800 Pa (Kasting, 1991; Head et al., 2003). The lichen Pleopsidium chlorophanum is an extremophile that lives in very cold, dry, high-altitude habitats, which are Earth's best approximation of the Martian surface. Samples with P. chlorophanum were exposed uninterruptedly to simulated conditions of the unprotected Martian surface (i.e. 6344 kJ m-2) and protected niche conditions (269 kJ m-2) for 34 days. Under unprotected Martian surface conditions the fungal symbiont decreases its metabolic activity and it was unclear if the algal symbiont of the lichen was still actively photosynthesizing. However, under "protected site" conditions, the entire lichen not only survived and remained photosynthetically active, it even adapted physiologically by increasing its photosynthetic activity over 34 days.

Study on conditional probability of surface rupture: effect of fault dip and width of seismogenic layer

NASA Astrophysics Data System (ADS)

Inoue, N.

2017-12-01

The conditional probability of surface ruptures is affected by various factors, such as shallow material properties, process of earthquakes, ground motions and so on. Toda (2013) pointed out difference of the conditional probability of strike and reverse fault by considering the fault dip and width of seismogenic layer. This study evaluated conditional probability of surface rupture based on following procedures. Fault geometry was determined from the randomly generated magnitude based on The Headquarters for Earthquake Research Promotion (2017) method. If the defined fault plane was not saturated in the assumed width of the seismogenic layer, the fault plane depth was randomly provided within the seismogenic layer. The logistic analysis was performed to two data sets: surface displacement calculated by dislocation methods (Wang et al., 2003) from the defined source fault, the depth of top of the defined source fault. The estimated conditional probability from surface displacement indicated higher probability of reverse faults than that of strike faults, and this result coincides to previous similar studies (i.e. Kagawa et al., 2004; Kataoka and Kusakabe, 2005). On the contrary, the probability estimated from the depth of the source fault indicated higher probability of thrust faults than that of strike and reverse faults, and this trend is similar to the conditional probability of PFDHA results (Youngs et al., 2003; Moss and Ross, 2011). The probability of combined simulated results of thrust and reverse also shows low probability. The worldwide compiled reverse fault data include low fault dip angle earthquake. On the other hand, in the case of Japanese reverse fault, there is possibility that the conditional probability of reverse faults with less low dip angle earthquake shows low probability and indicates similar probability of strike fault (i.e. Takao et al., 2013). In the future, numerical simulation by considering failure condition of surface by the source fault would be performed in order to examine the amount of the displacement and conditional probability quantitatively.

Effect of hydrodynamics and surface roughness on the electrochemical behaviour of carbon steel in CSG produced water

NASA Astrophysics Data System (ADS)

Eyu, Gaius Debi; Will, Geoffrey; Dekkers, Willem; MacLeod, Jennifer

2015-12-01

The influence of fluid flow, surface roughness and immersion time on the electrochemical behaviour of carbon steel in coal seam gas produced water under static and hydrodynamic conditions has been studied. The disc electrode surface morphology before and after the corrosion test was characterized using scanning electron microscopy (SEM). The corrosion product was examined using X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD).The results show that the anodic current density increased with increasing surface roughness and consequently a decrease in corrosion surface resistance. Under dynamic flow conditions, the corrosion rate increased with increasing rotating speed due to the high mass transfer coefficient and formation of non-protective akaganeite β-FeO(OH) and goethite α-FeO(OH) corrosion scale at the electrode surface. The corrosion rate was lowest at 0 rpm. The corrosion rate decreased in both static and dynamic conditions with increasing immersion time. The decrease in corrosion rate is attributed to the deposition of corrosion products on the electrode surface. SEM results revealed that the rougher surface exhibited a great tendency toward pitting corrosion.

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

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

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

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

Evaluation of Surface Fatigue Strength Based on Surface Temperature

NASA Astrophysics Data System (ADS)

Deng, Gang; Nakanishi, Tsutomu

Surface temperature is considered to be an integrated index that is dependent on not only the load and the dimensions at the contact point but also the sliding velocity, rolling velocity, surface roughness, and lubrication conditions. Therefore, the surface durability of rollers and gears can be evaluated more exactly and simply by the use of surface temperature rather than Hertzian stress. In this research, surface temperatures of rollers under different rolling and sliding conditions are measured using a thermocouple. The effects of load P, mean velocity Vm and sliding velocity Vs on surface temperature are clarified. An experimental formula, which expresses the linear relationship between surface temperature and the P0.86Vs1.31Vm-0.83 value, is used to determine surface temperature. By comparing calculated and measured temperature on the tooth surface of a gear, this formula is confirmed to be applicable for gear tooth surface temperature calculation.

Insight of DFT and ab initio atomistic thermodynamics on the surface stability and morphology of In2O3

NASA Astrophysics Data System (ADS)

Zhang, Minhua; Wang, Wenyi; Chen, Yifei

2018-03-01

In2O3 catalysts show remarkable activity and selectivity in methanol synthesis from CO2 hydrogenation. In order to get insight into the surface stability of this catalyst, density functional theory and ab initio atomistic thermodynamics method were used to investigate the surface free energies of various facets as a function of oxygen chemical potential, as well as the influences of temperature, pressure and gas compositions. The results show that the (111) facet presents lowest surface free energy under oxygen-rich condition, while the indium-terminated (100) facet is the most stable one under oxygen-lean condition. Moreover, we applied Wulff construction to determine the equilibrium shape of In2O3 with different oxygen chemical potentials. The equilibrium shape under oxygen-lean condition is cubic, which only expose (100) facet, while, the equilibrium shape under oxygen-rich condition is octahedron, which only expose (111) facet. Meanwhile, the results agree well with what is observed experimentally. It is further predicted that Wulff shape of In2O3 exists in a truncated octahedron morphology in which the (100) surface becomes predominant plane under CO2 hydrogenation reaction conditions.

Mars Pathfinder Spacecraft, Lander, and Rover Testing in Simulated Deep Space and Mars Surface Environments

NASA Technical Reports Server (NTRS)

Johnson, Kenneth R.

1997-01-01

The Mars Pathfinder (MPF) Spacecraft was built and tested at the Jet Propulsion Laboratory during 1995/96. MPF is scheduled to launch in December 1996 and to land on Mars on July 4, 1997. The testing program for MPF required subjecting the mission hardware to both deep space and Mars surface conditions. A series of tests were devised and conducted from 1/95 to 7/96 to study the thermal response of the MPF spacecraft to the environmental conditions in which it will be exposed during the cruise phase (on the way to Mars) and the lander phase (landed on Mars) of the mission. Also, several tests were conducted to study the thermal characteristics of the Mars rover, Sojourner, under Mars surface environmental conditions. For these tests, several special test fixtures and methods were devised to simulate the required environmental conditions. Creating simulated Mars surface conditions was a challenging undertaking since Mars' surface is subjected to diurnal cycling between -20 C and -85 C, with windspeeds to 20 m/sec, occurring in an 8 torr CO2 atmosphere. This paper describes the MPF test program which was conducted at JPL to verify the MPF thermal design.

Flow boundary conditions for chain-end adsorbing polymer blends.

PubMed

Zhou, Xin; Andrienko, Denis; Delle Site, Luigi; Kremer, Kurt

2005-09-08

Using the phenol-terminated polycarbonate blend as an example, we demonstrate that the hydrodynamic boundary conditions for a flow of an adsorbing polymer melt are extremely sensitive to the structure of the epitaxial layer. Under shear, the adsorbed parts (chain ends) of the polymer melt move along the equipotential lines of the surface potential whereas the adsorbed additives serve as the surface defects. In response to the increase of the number of the adsorbed additives the surface layer becomes thinner and solidifies. This results in a gradual transition from the slip to the no-slip boundary condition for the melt flow, with a nonmonotonic dependence of the slip length on the surface concentration of the adsorbed ends.

Atomistic modelling of evaporation and explosive boiling of thin film liquid argon over internally recessed nanostructured surface

NASA Astrophysics Data System (ADS)

Hasan, Mohammad Nasim; Shavik, Sheikh Mohammad; Rabbi, Kazi Fazle; Haque, Mominul

2016-07-01

Molecular dynamics (MD) simulations have been carried out to investigate evaporation and explosive boiling phenomena of thin film liquid argon on nanostructured solid surface with emphasis on the effect of solid-liquid interfacial wettability. The nanostructured surface considered herein consists of trapezoidal internal recesses of the solid platinum wall. The wetting conditions of the solid surface were assumed such that it covers both the hydrophilic and hydrophobic conditions and hence effect of interfacial wettability on resulting evaporation and boiling phenomena was the main focus of this study. The initial configuration of the simulation domain comprised of a three phase system (solid platinum, liquid argon and vapor argon) on which equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. After equilibrium of the three-phase system was established, the wall was set to different temperatures (130 K and 250 K for the case of evaporation and explosive boiling respectively) to perform non-equilibrium molecular dynamics (NEMD). The variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat flux normal to the solid surface was also calculated to illustrate the effectiveness of heat transfer for hydrophilic and hydrophobic surfaces in cases of both nanostructured surface and flat surface. The results obtained show that both the wetting condition of the surface and the presence of internal recesses have significant effect on normal evaporation and explosive boiling of the thin liquid film. The heat transfer from solid to liquid in cases of surface with recesses are higher compared to flat surface without recesses. Also the surface with higher wettability (hydrophilic) provides more favorable conditions for boiling than the low-wetting surface (hydrophobic) and therefore, liquid argon responds quickly and shifts from liquid to vapor phase faster in case of hydrophilic surface. The heat transfer rate is also much higher in case of hydrophilic surface.

Atomistic modelling of evaporation and explosive boiling of thin film liquid argon over internally recessed nanostructured surface

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

Hasan, Mohammad Nasim, E-mail: nasim@me.buet.ac.bd.com; Shavik, Sheikh Mohammad, E-mail: shavik@me.buet.ac.bd.com; Rabbi, Kazi Fazle, E-mail: rabbi35.me10@gmail.com

2016-07-12

Molecular dynamics (MD) simulations have been carried out to investigate evaporation and explosive boiling phenomena of thin film liquid argon on nanostructured solid surface with emphasis on the effect of solid-liquid interfacial wettability. The nanostructured surface considered herein consists of trapezoidal internal recesses of the solid platinum wall. The wetting conditions of the solid surface were assumed such that it covers both the hydrophilic and hydrophobic conditions and hence effect of interfacial wettability on resulting evaporation and boiling phenomena was the main focus of this study. The initial configuration of the simulation domain comprised of a three phase system (solidmore » platinum, liquid argon and vapor argon) on which equilibrium molecular dynamics (EMD) was performed to reach equilibrium state at 90 K. After equilibrium of the three-phase system was established, the wall was set to different temperatures (130 K and 250 K for the case of evaporation and explosive boiling respectively) to perform non-equilibrium molecular dynamics (NEMD). The variation of temperature and density as well as the variation of system pressure with respect to time were closely monitored for each case. The heat flux normal to the solid surface was also calculated to illustrate the effectiveness of heat transfer for hydrophilic and hydrophobic surfaces in cases of both nanostructured surface and flat surface. The results obtained show that both the wetting condition of the surface and the presence of internal recesses have significant effect on normal evaporation and explosive boiling of the thin liquid film. The heat transfer from solid to liquid in cases of surface with recesses are higher compared to flat surface without recesses. Also the surface with higher wettability (hydrophilic) provides more favorable conditions for boiling than the low-wetting surface (hydrophobic) and therefore, liquid argon responds quickly and shifts from liquid to vapor phase faster in case of hydrophilic surface. The heat transfer rate is also much higher in case of hydrophilic surface.« less

Experimental study on soluble chemical transfer to surface runoff from soil.

PubMed

Tong, Juxiu; Yang, Jinzhong; Hu, Bill X; Sun, Huaiwei

2016-10-01

Prevention of chemical transfer from soil to surface runoff, under condition of irrigation and subsurface drainage, would improve surface water quality. In this paper, a series of laboratory experiments were conducted to assess the effects of various soil and hydraulic factors on chemical transfer from soil to surface runoff. The factors include maximum depth of ponding water on soil surface, initial volumetric water content of soil, depth of soil with low porosity, type or texture of soil and condition of drainage. In the experiments, two soils, sand and loam, mixed with different quantities of soluble KCl were filled in the sandboxes and prepared under different initial saturated conditions. Simulated rainfall induced surface runoff are operated in the soils, and various ponding water depths on soil surface are simulated. Flow rates and KCl concentration of surface runoff are measured during the experiments. The following conclusions are made from the study results: (1) KCl concentration in surface runoff water would decrease with the increase of the maximum depth of ponding water on soil surface; (2) KCl concentration in surface runoff water would increase with the increase of initial volumetric water content in the soil; (3) smaller depth of soil with less porosity or deeper depth of soil with larger porosity leads to less KCl transfer to surface runoff; (4) the soil with finer texture, such as loam, could keep more fertilizer in soil, which will result in more KCl concentration in surface runoff; and (5) good subsurface drainage condition will increase the infiltration and drainage rates during rainfall event and will decrease KCl concentration in surface runoff. Therefore, it is necessary to reuse drained fertile water effectively during rainfall, without polluting groundwater. These study results should be considered in agriculture management to reduce soluble chemical transfer from soil to surface runoff for reducing non-point sources pollution.

The Role of Surface Chemistry in Adhesion and Wetting of Gecko Toe Pads

PubMed Central

Badge, Ila; Stark, Alyssa Y.; Paoloni, Eva L.; Niewiarowski, Peter H.; Dhinojwala, Ali

2014-01-01

An array of micron-sized setal hairs offers geckos a unique ability to walk on vertical surfaces using van der Waals interactions. Although many studies have focused on the role of surface morphology of the hairs, very little is known about the role of surface chemistry on wetting and adhesion. We expect that both surface chemistry and morphology are important, not only to achieve optimum dry adhesion but also for increased efficiency in self-cleaning of water and adhesion under wet conditions. Here, we used a plasma-based vapor deposition process to coat the hairy patterns on gecko toe pad sheds with polar and non-polar coatings without significantly perturbing the setal morphology. By a comparison of wetting across treatments, we show that the intrinsic surface of gecko setae has a water contact angle between 70–90°. As expected, under wet conditions, adhesion on a hydrophilic surface (glass) was lower than that on a hydrophobic surface (alkyl-silane monolayer on glass). Surprisingly under wet and dry conditions the adhesion was comparable on the hydrophobic surface, independent of the surface chemistry of the setal hairs. This work highlights the need to utilize morphology and surface chemistry in developing successful synthetic adhesives with desirable adhesion and self-cleaning properties. PMID:25323067

Controlled surface diffusion in plasma-enhanced chemical vapor deposition of GaN nanowires.

PubMed

Hou, Wen Chi; Hong, Franklin Chau-Nan

2009-02-04

This study investigates the growth of GaN nanowires by controlling the surface diffusion of Ga species on sapphire in a plasma-enhanced chemical vapor deposition (CVD) system. Under nitrogen-rich growth conditions, Ga has a tendency to adsorb on the substrate surface diffusing to nanowires to contribute to their growth. The significance of surface diffusion on the growth of nanowires is dependent on the environment of the nanowire on the substrate surface as well as the gas phase species and compositions. Under nitrogen-rich growth conditions, the growth rate is strongly dependent on the surface diffusion of gallium, but the addition of 5% hydrogen in nitrogen plasma instantly diminishes the surface diffusion effect. Gallium desorbs easily from the surface by reaction with hydrogen. On the other hand, under gallium-rich growth conditions, nanowire growth is shown to be dominated by the gas phase deposition, with negligible contribution from surface diffusion. This is the first study reporting the inhibition of surface diffusion effects by hydrogen addition, which can be useful in tailoring the growth and characteristics of nanowires. Without any evidence of direct deposition on the nanowire surface, gallium and nitrogen are shown to dissolve into the catalyst for growing the nanowires at 900 degrees C.

The Role of Surface Chemistry in Adhesion and Wetting of Gecko Toe Pads

NASA Astrophysics Data System (ADS)

Badge, Ila; Stark, Alyssa Y.; Paoloni, Eva L.; Niewiarowski, Peter H.; Dhinojwala, Ali

2014-10-01

An array of micron-sized setal hairs offers geckos a unique ability to walk on vertical surfaces using van der Waals interactions. Although many studies have focused on the role of surface morphology of the hairs, very little is known about the role of surface chemistry on wetting and adhesion. We expect that both surface chemistry and morphology are important, not only to achieve optimum dry adhesion but also for increased efficiency in self-cleaning of water and adhesion under wet conditions. Here, we used a plasma-based vapor deposition process to coat the hairy patterns on gecko toe pad sheds with polar and non-polar coatings without significantly perturbing the setal morphology. By a comparison of wetting across treatments, we show that the intrinsic surface of gecko setae has a water contact angle between 70-90°. As expected, under wet conditions, adhesion on a hydrophilic surface (glass) was lower than that on a hydrophobic surface (alkyl-silane monolayer on glass). Surprisingly under wet and dry conditions the adhesion was comparable on the hydrophobic surface, independent of the surface chemistry of the setal hairs. This work highlights the need to utilize morphology and surface chemistry in developing successful synthetic adhesives with desirable adhesion and self-cleaning properties.

CADDIS Volume 2. Sources, Stressors and Responses: Urbanization - Stormwater Runoff

EPA Pesticide Factsheets

Introduction to impervious surfaces associated with urbanization, overview of effects vs. total imperviousness, overview of how impervious surfaces affect biotic condition, summary of threshold values of impervious cover for stream biotic condition.

Equilibrium Wall Model Implementation in a Nodal Finite Element Flow Solver JENRE for Large Eddy Simulations

DTIC Science & Technology

2017-11-13

condition is applied to the inviscid and viscous fluxes on the wall to satisfy the surface physical condition, but a non -zero surface tangential...velocity profiles and turbulence quantities predicted by the current wall-model implementation agree well with available experimental data and...implementations. The volume and surface integrals based on the non -zero surface velocity in a cell adjacent to the wall show a good agreement with those

Response of near-surface currents in the Indian Ocean to the anomalous atmospheric condition in 2015

NASA Astrophysics Data System (ADS)

Utari, P. A.; Nurkhakim, M. Y.; Setiabudidaya, D.; Iskandar, I.

2018-05-01

Anomalous ocean-atmosphere conditions were detected in the tropical Indian Ocean during boreal spring to boreal winter 2015. It was suggested that the anomalous conditions were characteristics of the positive Indian Ocean Dipole (pIOD) event. The purpose of this investigation was to investigate the response of near-surface currents in the tropical Indian Ocean to the anomalous atmospheric condition in 2015. Near-surface current from OSCAR (Ocean Surface Current Analyses Real Time) reanalysis data combined with the sea surface temperature (SST) data from OISST – NOAA, sea surface height (SSH) and surface winds from the ECMWF were used in this investigation. The analysis showed that the evolution of 2015 pIOD started in June/July, peaked in the September and terminated in late November 2015. Correlated with the evolution of the pIOD, easterly winds anomalies were detected along the equator. As the oceanic response to these easterly wind anomalies, the surface currents anomalously westward during the peak of the pIOD. It was interesting to note that the evolution of 2015 pIOD event was closely related to the ocean wave dynamics as revealed by the SSH data. Downwelling westward propagating Rossby waves were detected in the southwestern tropical Indian Ocean. Once reached the western boundary of the Indian Ocean, they were redirected back into interior Indian Ocean and propagating eastward as the downwelling Kelvin waves.

Experimental Studies of Hydrogenation and Other Reactions on Surfaces Under Astrophysically Relevant Conditions

NASA Technical Reports Server (NTRS)

Vidali, Gianfranco

1998-01-01

The goal of our project is to study hydrogen recombination reactions on solid surfaces under conditions that are relevant in astrophysics. Laboratory experiments were conducted using low-flux, cold atomic H and D beams impinging on a sample kept under ultra high vacuum conditions. Realistic analogues of interstellar dust grains were used. Our results show that current models for hydrogen recombination reactions have to be modified to take into account the role of activated diffusion of H on surfaces even at low temperature.

Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration.

PubMed

Reis, Gustavo Msm; Grigg, John; Chua, Brian; Lee, Anne; Lim, Ridia; Higgins, Ralph; Martins, Alessandra; Goldberg, Ivan; Clement, Colin I

2017-01-01

The aim of this article is to evaluate the rate of patients developing sustained elevated intraocular pressure (IOP) after ranibizumab (Lucentis) intravitreal (IVT) injections. This is a retrospective study. Charts of 192 consecutive patients receiving Lucentis for age-related macular degeneration (AMD) were retrospectively reviewed. We enrolled patients with at least two IOP measurements between injections. Elevated IOP was defined as >21 mm Hg with an increase of at least 20% from baseline. Noninjected contralateral eyes of the same patient cohort were used as control. Primary outcome was defined as elevated IOP. Secondary outcomes were presence and type of glaucoma, number of injections, and time to IOP elevation. Elevated IOP occurred at a significantly higher rate in eyes receiving IVT ranibizumab (7.47%; n = 9) compared with control (0.93%; n = 1). Patients with preexisting glaucoma or ocular hypertension (OHT) were more likely to develop elevated IOP after IVT ranibizumab injection. Intravitreal ranibizumab injections are associated with sustained IOP elevation in some eyes. Reis GMSM, Grigg J, Chua B, Lee A, Lim R, Higgins R, Martins A, Goldberg I, Clement CI. The Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration. J Curr Glaucoma Pract 2017;11(1):3-7.

Preference for a stimulus that follows a relatively aversive event: contrast or delay reduction?

PubMed

Singer, Rebecca A; Berry, Laura M; Zentall, Thomas R

2007-03-01

Several types of contrast effects have been identified including incentive contrast, anticipatory contrast, and behavioral contrast. Clement, Feltus, Kaiser, and Zentall (2000) proposed a type of contrast that appears to be different from these others and called it within-trial contrast. In this form of contrast the relative value of a reinforcer depends on the events that occur immediately prior to the reinforcer. Reinforcers that follow relatively aversive events are preferred over those that follow less aversive events. In many cases the delay reduction hypothesis proposed by Fantino (1969) also can account for such effects. The current experiments provide a direct test of the delay reduction and contrast hypotheses by manipulating the schedule of reinforcement while holding trial duration constant. In Experiment 1, preference for fixed-interval (FI) versus differential-reinforcement-of-other-behavior (DRO) schedules of reinforcement was assessed. Some pigeons preferred one schedule over the other while others demonstrated a position (side) preference. Thus, no systematic preference was found. In Experiment 2, a simultaneous color discrimination followed the FI or DRO schedule, and following training, preference was assessed by presenting the two positive stimuli simultaneously. Consistent with the contrast hypothesis, pigeons showed a significant preference for the positive stimulus that in training had followed their less preferred schedule.

Within-trial contrast: when you see it and when you don't.

PubMed

Zentall, Thomas R

2008-02-01

Within-trial contrast occurs when a discriminative stimulus that is preceded by a relatively aversive event is preferred over another that is preceded by a less aversive event. Recent failures to replicate (Arantes & Grace, 2008; Vasconcelos, Urcuioli, & Lionello-DeNolf, 2007) may allow us to identify factors that may be responsible. In the case of Vasconcelos et al., it is likely that insufficient training was provided (often 35-65 sessions are required). In the case of Arantes and Grace (Experiment 2), these pigeons had been involved in prior experiments involving lean schedules of reinforcement, and we find that prior experience its occurrence. with lean (relatively aversive) schedules appears to reduce the presumed aversiveness of the many-peck requirement, thus obviating the contrast effect. Finally, in the case of Vasconcelos and Urcuioli (2008), although the contrast effect with a simultaneous discrimination was not reliable, it was not reliably smaller than with a successive discrimination that did show a reliable effect, and the contrast effect was also similar in magnitude to a reliable effect reported by Kacelnik and Marsh (2002). Thus, although there have been several failures to replicate the original effects reported by Clement, Feltus, Kaiser and Zentall (2000), insufficient training, prior history with lean schedules of reinforcement, and low statistical power may have been responsible for those failures.

Planning ahead for asteroid and comet hazard mitigation, phase 1: parameter space exploration and scenario modeling

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

Plesko, Catherine S; Clement, R Ryan; Weaver, Robert P

2009-01-01

The mitigation of impact hazards resulting from Earth-approaching asteroids and comets has received much attention in the popular press. However, many questions remain about the near-term and long-term, feasibility and appropriate application of all proposed methods. Recent and ongoing ground- and space-based observations of small solar-system body composition and dynamics have revolutionized our understanding of these bodies (e.g., Ryan (2000), Fujiwara et al. (2006), and Jedicke et al. (2006)). Ongoing increases in computing power and algorithm sophistication make it possible to calculate the response of these inhomogeneous objects to proposed mitigation techniques. Here we present the first phase of amore » comprehensive hazard mitigation planning effort undertaken by Southwest Research Institute and Los Alamos National Laboratory. We begin by reviewing the parameter space of the object's physical and chemical composition and trajectory. We then use the radiation hydrocode RAGE (Gittings et al. 2008), Monte Carlo N-Particle (MCNP) radiation transport (see Clement et al., this conference), and N-body dynamics codes to explore the effects these variations in object properties have on the coupling of energy into the object from a variety of mitigation techniques, including deflection and disruption by nuclear and conventional munitions, and a kinetic impactor.« less

2D and 3D Models of Convective Turbulence and Oscillations in Intermediate-Mass Main-Sequence Stars

NASA Astrophysics Data System (ADS)

Guzik, Joyce Ann; Morgan, Taylor H.; Nelson, Nicholas J.; Lovekin, Catherine; Kitiashvili, Irina N.; Mansour, Nagi N.; Kosovichev, Alexander

2015-08-01

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the sun, using three separate approaches: 1) Applying the spherical 3D MHD ASH (Anelastic Spherical Harmonics) code to simulate the core convection and radiative zone. Our goal is to determine whether core convection can excite low-frequency gravity modes, and thereby explain the presence of low frequencies for some hybrid gamma Dor/delta Sct variables for which the envelope convection zone is too shallow for the convective blocking mechanism to drive g modes; 2) Using the 3D planar ‘StellarBox’ radiation hydrodynamics code to model the envelope convection zone and part of the radiative zone. Our goals are to examine the interaction of stellar pulsations with turbulent convection in the envelope, excitation of acoustic modes, and the role of convective overshooting; 3) Applying the ROTORC 2D stellar evolution and dynamics code to calculate evolution with a variety of initial rotation rates and extents of core convective overshooting. The nonradial adiabatic pulsation frequencies of these nonspherical models will be calculated using the 2D pulsation code NRO of Clement. We will present new insights into gamma Dor and delta Sct pulsations gained by multidimensional modeling compared to 1D model expectations.

Larval dispersion of the estuarine crab Neohelice granulata in coastal marine waters of the Southwest Atlantic

NASA Astrophysics Data System (ADS)

Bas, Claudia; Luppi, Tomás; Spivak, Eduardo; Schejter, Laura

2009-08-01

The estuarine brachyuran crab Neohelice granulata export their larvae from the parental intertidal population of the Mar Chiquita coastal lagoon, and probably other populations, to marine waters. The degree of larval dispersion or self-recruitment of populations is unknown. We evaluated the presence of all larval stages of N. granulata in coastal waters of Argentina between 37.9° and 35.8° S, at two different spatial scales: a broad scale of tens to hundreds of kilometers from the Río de la Plata estuary in the north, to Mar Chiquita lagoon in the south, and a small scale of hundreds of meters to some kilometers around the mouth of Mar Chiquita, during spring and summer. Additionally, we registered the larval composition and density at San Clemente creek population, in Samborombon Bay (Río de la Plata estuary), every 3 h along a 30-hour period. Evidence indicates that larval release of N. granulata is temporally synchronized with nocturnal ebb tides and all development from Zoea I to Zoea IV occur in areas close to the parental population, even with very different oceanographic characteristics. A possible mechanism based on salinity selection and wind-driven transport is proposed for such behavior, and some considerations related to the connectivity of present populations are made.

Listening in circles. Spoken drama and the architects of sound, 1750-1830.

PubMed

Tkaczyk, Viktoria

2014-07-01

The establishment of the discipline of architectural acoustics is generally attributed to the physicist Wallace Clement Sabine, who developed the formula for reverberation time around 1900, and with it the possibility of making calculated prognoses about the acoustic potential of a particular design. If, however, we shift the perspective from the history of this discipline to the history of architectural knowledge and praxis, it becomes apparent that the topos of 'good sound' had already entered the discourse much earlier. This paper traces the Europe-wide discussion on theatre architecture between 1750 and 1830. It will be shown that the period of investigation is marked by an increasing interest in auditorium acoustics, one linked to the emergence of a bourgeois theatre culture and the growing socio-political importance of the spoken word. In the wake of this development the search among architects for new methods of acoustic research started to differ fundamentally from an analogical reasoning on the nature of sound propagation and reflection, which in part dated back to antiquity. Through their attempts to find new ways of visualising the behaviour of sound in enclosed spaces and to rethink both the materiality and the mediality of theatre auditoria, architects helped pave the way for the establishment of architectural acoustics as an academic discipline around 1900.

Christopher Addison: a realist in pursuit of dreams.

PubMed

Honigsbaum, F

1993-01-01

Addison was the only politician present at the start and end of the legislative process that produced the National Health Service. Having established a national reputation as an anatomist at the age of 41, he abandoned medicine for politics, entering Parliament in 1910 as a Liberal, moving to Labour in 1923, accepting a peerage in 1937, and ending as Leader of the Lords from 1945-1951. His life in politics was as long as the one before it--41 years--with all but 11 as a member of one House or the other. He served in three Cabinets, holding eight offices while in the lower House and four in the upper. Lacking debating skill or a charismatic personality, he owed his advancement to his industrious character and the regard with which he was held by two prime ministers, David Lloyd George and Clement Attlee. Though doubts were raised about his administrative ability, no one ever questioned his courage, diligence, perseverance or ability to adapt to whatever task he undertook. He pursued radical goals throughout his long life but always with regard to the realities of politics. His most important contribution, certainly in the field of public health, lay in the part he played in the creation of the panel system and the Ministry of Health.

The impact of the care equity project with community/public health nursing students.

PubMed

Kamau-Small, Sylvia; Joyce, Barbara; Bermingham, Neysa; Roberts, Jada; Robbins, Curtis

2015-01-01

The purpose of this article is to report on the evaluation process of a multi-disciplinary interactive teaching-learning workshop implemented in a college of nursing baccalaureate program. A 6-hr workshop on cultural humility and care equity was implemented using educational theater to bring clinical situations involved in community/public health practice into the classroom. One hundred and forty-nine students participated in the workshop. Stages of Change (Prochaska and DiClemente [2005] Handbook of psychotherapy integration. New York: Oxford University Press) and the Learning Transfer Barriers Framework (Price, Miller, Rahm, Brace, & Larson [2010] Journal of Continuing Education in the Health Professions, 30, 237-245.) provided conceptual underpinnings for project evaluation. Nursing students completed a quiz, post-workshop online surveys at 2 and 8 weeks, and a clinical application report (CAR). Survey data provided information on barriers to the transfer of knowledge from theory class to the clinical setting. Qualitative methods were used to audit the CARs. Each CAR was independently reviewed to determine the Stage of Change reflected in the narrative. Workshop evaluation outcomes provide evidence that cultural humility skill building has created behavior change in clinical practice for new health care community/public health nursing providers. © 2014 Wiley Periodicals, Inc.

Development of an instrument to assess readiness to recover in anorexia nervosa.

PubMed

Rieger, E; Touyz, S; Schotte, D; Beumont, P; Russell, J; Clarke, S; Kohn, M; Griffiths, R

2000-12-01

The degree to which patients with anorexia nervosa demonstrate readiness to recover from their illness has received scant theoretical or empirical attention. Investigating the prevalence and degree of amotivation for recovery in anorexia nervosa, its role in outcome, and the effectiveness of interventions designed to enhance readiness to recover necessitates the existence of a reliable and valid measure of motivational issues relevant to the disorder. The present study aimed to develop and evaluate an instrument for assessing readiness to recover in anorexia nervosa, namely, the Anorexia Nervosa Stages of Change Questionnaire (ANSOCQ), a 23-item self-report questionnaire based on Prochaska and DiClemente's stages of change model. Seventy-one inpatients with anorexia nervosa participated in the study. On several occasions during their admission, participants completed the ANSOCQ as well as questionnaires assessing readiness to recover, anorexic symptomatology, general distress, and social desirability. The ANSOCQ demonstrated good internal consistency (.90) and 1-week test-retest reliability (.89). Various aspects of validity were also supported, such as significant relationships with other instruments assessing readiness to recover and the prediction of weight gain during different periods of treatment. The results suggest that the ANSOCQ is a psychometrically sound instrument that may prove useful in investigating the role of readiness to recover in anorexia nervosa. Copyright 2000 John Wiley & Sons, Inc.

Stability analysis of nanoscale surface patterns in stressed solids

NASA Astrophysics Data System (ADS)

Kostyrko, Sergey A.; Shuvalov, Gleb M.

2018-05-01

Here, we use the theory of surface elasticity to extend the morphological instability analysis of stressed solids developed in the works of Asaro, Tiller, Grinfeld, Srolovitz and many others. Within the framework of Gurtin-Murdoch model, the surface phase is assumed to be a negligibly thin layer with the elastic properties which differ from those of the bulk material. We consider the mass transport mechanism driven by the variation of surface and bulk energy along undulated surface of stressed solid. The linearized surface evolution equation is derived in the case of plane strain conditions and describes the amplitude change of surface perturbations with time. A parametric analysis of this equation leads to the definition of critical conditions which depend on undulation wavelength, residual surface stress, applied loading, surface and bulk elastic constants and predict the surface morphological stability.

The PROCESS experiment: amino and carboxylic acids under Mars-like surface UV radiation conditions in low-earth orbit.

PubMed

Noblet, Audrey; Stalport, Fabien; Guan, Yuan Yong; Poch, Olivier; Coll, Patrice; Szopa, Cyril; Cloix, Mégane; Macari, Frédérique; Raulin, Francois; Chaput, Didier; Cottin, Hervé

2012-05-01

The search for organic molecules at the surface of Mars is a top priority of the next Mars exploration space missions: Mars Science Laboratory (NASA) and ExoMars (ESA). The detection of organic matter could provide information about the presence of a prebiotic chemistry or even biological activity on this planet. Therefore, a key step in interpretation of future data collected by these missions is to understand the preservation of organic matter in the martian environment. Several laboratory experiments have been devoted to quantifying and qualifying the evolution of organic molecules under simulated environmental conditions of Mars. However, these laboratory simulations are limited, and one major constraint is the reproduction of the UV spectrum that reaches the surface of Mars. As part of the PROCESS experiment of the European EXPOSE-E mission on board the International Space Station, a study was performed on the photodegradation of organics under filtered extraterrestrial solar electromagnetic radiation that mimics Mars-like surface UV radiation conditions. Glycine, serine, phthalic acid, phthalic acid in the presence of a mineral phase, and mellitic acid were exposed to these conditions for 1.5 years, and their evolution was determined by Fourier transform infrared spectroscopy after their retrieval. The results were compared with data from laboratory experiments. A 1.5-year exposure to Mars-like surface UV radiation conditions in space resulted in complete degradation of the organic compounds. Half-lives between 50 and 150 h for martian surface conditions were calculated from both laboratory and low-Earth orbit experiments. The results highlight that none of those organics are stable under low-Earth orbit solar UV radiation conditions.

Analysis of surface integrity in machining of AISI 304 stainless steel under various cooling and cutting conditions

NASA Astrophysics Data System (ADS)

Klocke, F.; Döbbeler, B.; Lung, S.; Seelbach, T.; Jawahir, I. S.

2018-05-01

Recent studies have shown that machining under specific cooling and cutting conditions can be used to induce a nanocrystalline surface layer in the workspiece. This layer has beneficial properties, such as improved fatigue strength, wear resistance and tribological behavior. In machining, a promising approach for achieving grain refinement in the surface layer is the application of cryogenic cooling. The aim is to use the last step of the machining operation to induce the desired surface quality to save time-consuming and expensive post machining surface treatments. The material used in this study was AISI 304 stainless steel. This austenitic steel suffers from low yield strength that limits its technological applications. In this paper, liquid nitrogen (LN2) as cryogenic coolant, as well as minimum quantity lubrication (MQL), was applied and investigated. As a reference, conventional flood cooling was examined. Besides the cooling conditions, the feed rate was varied in four steps. A large rounded cutting edge radius and finishing cutting parameters were chosen to increase the mechanical load on the machined surface. The surface integrity was evaluated at both, the microstructural and the topographical levels. After turning experiments, a detailed analysis of the microstructure was carried out including the imaging of the surface layer and hardness measurements at varying depths within the machined layer. Along with microstructural investigations, different topological aspects, e.g., the surface roughness, were analyzed. It was shown that the resulting microstructure strongly depends on the cooling condition. This study also shows that it was possible to increase the micro hardness in the top surface layer significantly.

Impact of Dental Implant Surface Modifications on Osseointegration

PubMed Central

Smeets, Ralf; Stadlinger, Bernd; Schwarz, Frank; Beck-Broichsitter, Benedicta; Jung, Ole; Precht, Clarissa; Kloss, Frank; Gröbe, Alexander; Heiland, Max

2016-01-01

Objective. The aim of this paper is to review different surface modifications of dental implants and their effect on osseointegration. Common marketed as well as experimental surface modifications are discussed. Discussion. The major challenge for contemporary dental implantologists is to provide oral rehabilitation to patients with healthy bone conditions asking for rapid loading protocols or to patients with quantitatively or qualitatively compromised bone. These charging conditions require advances in implant surface design. The elucidation of bone healing physiology has driven investigators to engineer implant surfaces that closely mimic natural bone characteristics. This paper provides a comprehensive overview of surface modifications that beneficially alter the topography, hydrophilicity, and outer coating of dental implants in order to enhance osseointegration in healthy as well as in compromised bone. In the first part, this paper discusses dental implants that have been successfully used for a number of years focusing on sandblasting, acid-etching, and hydrophilic surface textures. Hereafter, new techniques like Discrete Crystalline Deposition, laser ablation, and surface coatings with proteins, drugs, or growth factors are presented. Conclusion. Major advancements have been made in developing novel surfaces of dental implants. These innovations set the stage for rehabilitating patients with high success and predictable survival rates even in challenging conditions. PMID:27478833

Geostatistics: a new tool for describing spatially-varied surface conditions from timber harvested and burned hillslopes

Treesearch

Peter R. Robichaud

1997-01-01

Geostatistics provides a method to describe the spatial continuity of many natural phenomena. Spatial models are based upon the concept of scaling, kriging and conditional simulation. These techniques were used to describe the spatially-varied surface conditions on timber harvest and burned hillslopes. Geostatistical techniques provided estimates of the ground cover (...

Evaluation of the Effect of Surface Finish on High-Cycle Fatigue for SLM-IN718

NASA Technical Reports Server (NTRS)

Lambert, Dennis M.

2016-01-01

A high-cycle fatigue (HCF) knockdown factor was estimated for Inconel 718, manufactured with the selective laser melt (SLM) process. This factor is the reduction at a common fatigue life from the maximum stress in fatigue for low-stress ground (LSG) specimens to the maximum stress of those left with the original surface condition. Various vendors provided specimens. To reduce the number of degrees-of-freedom, only one heat treat condition was evaluated. Testing temperatures included room temperature, 800F, 1000F, and 1200F. The two surface conditions were compared at constant lives, where data was available. The recommended knockdown factor of the as-built surface condition (average roughness of approximately 245 micro-inches/inch) versus low-stress ground condition (roughness <= 4 micro-inches/inch) is approximately 1/3 or 33%. This is to say that for the as-built surface condition, a maximum stress of 2/3 of the stress for LSG can be expected to produce the same life in the as built surface condition. As an alternative method, the surface finish was incorporated into a new parameter with the maximum stress. The new parameter was formulated to be similar to the fracture mechanics stress intensity factor, and it was named the pseudo stress intensity factor, Kp. Using Kp, the variance seemed acceptable across all sources, and the knockdown factor was estimated over the range of data identified by Kp where data occurred. A plot of the results suggests that the knockdown factor is a function of temperature, and that for low lives the knockdown is greater than the knockdown observed above about one million cycles, where it stabilizes. One data point at room temperature was clearly different, and the sparsity of data in the higher life region reduces the value of these results. The method does appear to provide useful results, and further characterization of the method is suggested.

Colonization by Cladosporium spp. of painted metal surfaces associated with heating and air conditioning systems

NASA Technical Reports Server (NTRS)

Ahearn, D. G.; Simmons, R. B.; Switzer, K. F.; Ajello, L.; Pierson, D. L.

1991-01-01

Cladosporium cladosporioides and C. hebarum colonized painted metal surfaces of covering panels and register vents of heating, air conditioning and ventilation systems. Hyphae penetrated the paint film and developed characteristic conidiophores and conidia. The colonies were tightly appressed to the metal surface and conidia were not readily detectable via standard air sampling procedures.

Preliminary evaluation of cavitation resistance of type 316LN stainless steel in mercury using a vibratory horn

NASA Astrophysics Data System (ADS)

Pawel, S. J.; Manneschmidt, E. T.

2003-05-01

Type 316LN stainless steel in a variety of conditions (annealed, cold-worked, surface-modified) was exposed to cavitation conditions in stagnant mercury using a vibratory horn. The test conditions included peak-to-peak displacement of the specimen surface of 25 μm at a frequency of 20 kHz and a mercury temperature in the range -5 to 80 °C. Following a brief incubation period in which little or no damage was observed, specimens of annealed 316LN exhibited increasing weight loss and surface roughening with increasing exposure times. Examination of test surfaces with the scanning electron microscope revealed primarily general/uniform wastage in all cases but, for long exposure times, a few randomly oriented 'pits' were also observed. Type 316LN that was 50% cold-worked was considerably more resistant to cavitation erosion damage than annealed material, but the surface modifications (CrN coating, metallic glass coating, laser treatment to form a diamond-like surface) provided little or no protection for the substrate. In addition, the cavitation erosion resistance of other materials - Inconel 718, Nitronic 60, and Stellite 3 - was also compared with that of 316LN for identical screening test conditions.

Surface pre-conditioning with bioactive glass air-abrasion can enhance enamel white spot lesion remineralization.

PubMed

Milly, Hussam; Festy, Frederic; Andiappan, Manoharan; Watson, Timothy F; Thompson, Ian; Banerjee, Avijit

2015-05-01

To evaluate the effect of pre-conditioning enamel white spot lesion (WSL) surfaces using bioactive glass (BAG) air-abrasion prior to remineralization therapy. Ninety human enamel samples with artificial WSLs were assigned to three WSL surface pre-conditioning groups (n=30): (a) air-abrasion with BAG-polyacrylic acid (PAA-BAG) powder, (b) acid-etching using 37% phosphoric acid gel (positive control) and (c) unconditioned (negative control). Each group was further divided into three subgroups according to the following remineralization therapy (n=10): (I) BAG paste (36 wt.% BAG), (II) BAG slurry (100 wt.% BAG) and (III) de-ionized water (negative control). The average surface roughness and the lesion step height compared to intra-specimen sound enamel reference points were analyzed using non-contact profilometry. Optical changes within the lesion subsurface compared to baseline scans were assessed using optical coherence tomography (OCT). Knoop microhardness evaluated the WSLs' mechanical properties. Raman micro-spectroscopy measured the v-(CO3)(2-)/v1-(PO4)(3-) ratio. Structural changes in the lesion were observed using confocal laser scanning microscopy (CLSM) and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX). All comparisons were considered statistically significant if p<0.05. PAA-BAG air-abrasion removed 5.1 ± 0.6 μm from the lesion surface, increasing the WSL surface roughness. Pre-conditioning WSL surfaces with PAA-BAG air-abrasion reduced subsurface light scattering, increased the Knoop microhardness and the mineral content of the remineralized lesions (p<0.05). SEM-EDX revealed mineral depositions covering the lesion surface. BAG slurry resulted in a superior remineralization outcome, when compared to BAG paste. Pre-conditioning WSL surfaces with PAA-BAG air-abrasion modified the lesion surface physically and enhanced remineralization using BAG 45S5 therapy. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Perfluoropolyalkylether Oil Degradation: Inference of FeF3 Formation on Steel Surfaces under Boundary Conditions

DTIC Science & Technology

1985-08-01

REPORT SD-TR-85-37 O,-) Lfl Perfluoropolyalkylether Oil Degradation: Inference of FeF 3 Formation on Steel Surfaces I under Boundary Conditions DAVID...S. TYPE OF REPORT & PERIOD COVERED PERFLUOROPOLYALKYLETHER OIL DEGRADATION: INFERENCE OF FeF3 FORMATION ON STEELSURFACES UNDER BOUNDARY CONDITIONS 0...number) Boundary conditions Oil Degradation Perfluoropolyalkylether FeF3 Wear test Lubrication .... 440C 20. ABSTRACT (Contlnue o 0 ,systes sI . I

Asphalt surface treatment practice in southeastern United States.

DOT National Transportation Integrated Search

2014-07-01

It costs less to maintain roads in good condition than in poor condition. Pavement preservation is a set of : activities to extend pavement life, improve safety, and meet road user expectations. Surface treatments are : pavement preservation treatmen...

A Novel Method for Modeling Neumann and Robin Boundary Conditions in Smoothed Particle Hydrodynamics

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

Ryan, Emily M.; Tartakovsky, Alexandre M.; Amon, Cristina

2010-08-26

In this paper we present an improved method for handling Neumann or Robin boundary conditions in smoothed particle hydrodynamics. The Neumann and Robin boundary conditions are common to many physical problems (such as heat/mass transfer), and can prove challenging to model in volumetric modeling techniques such as smoothed particle hydrodynamics (SPH). A new SPH method for diffusion type equations subject to Neumann or Robin boundary conditions is proposed. The new method is based on the continuum surface force model [1] and allows an efficient implementation of the Neumann and Robin boundary conditions in the SPH method for geometrically complex boundaries.more » The paper discusses the details of the method and the criteria needed to apply the model. The model is used to simulate diffusion and surface reactions and its accuracy is demonstrated through test cases for boundary conditions describing different surface reactions.« less

Derivation and application of a class of generalized impedance boundary conditions, part 2

NASA Technical Reports Server (NTRS)

Volakis, J. L.; Senior, T. B. A.; Jin, J.-M.

1989-01-01

Boundary conditions involving higher order derivatives are presented by simulating surfaces whose reflection coefficients are known analytically, numerically, or experimentally. Procedures for determining the coefficients of the derivatives are discussed, along with the effect of displacing the surface where the boundary conditions are applied. Provided the coefficients satisfy a duality relation, equivalent forms of the boundary conditions involving tangential field components are deduced, and these provide the natural extension to non-planar surfaces. As an illustration, the simulation of metal-backed uniform and three-layer dielectric coatings is given. It is shown that fourth order conditions are capable of providing an accurate simulation for the uniform coating at least a quarter of a wavelength in thickness. Provided, though, some compromise in accuracy is acceptable, it is also shown that a third order condition may be sufficient for practical purposes when simulating uniform coatings.

A system to test the ground surface conditions of construction sites--for safe and efficient work without physical strain.

PubMed

Koningsveld, Ernst; van der Grinten, Maarten; van der Molen, Henk; Krause, Frank

2005-07-01

Ground surface conditions on construction sites have an important influence on the health and safety of workers and their productivity. The development of an expert-based "working conditions evaluation" system is described, intended to assist site managers in recognising unsatisfactory ground conditions and remedying these. The system was evaluated in the period 2002-2003. The evaluation shows that companies recognize poor soil/ground conditions as problematic, but are not aware of the specific physical workload hazards. The developed methods allow assessment of the ground surface quality and selection of appropriate measures for improvement. However, barriers exist at present to wide implementation of the system across the industry. Most significant of these is that responsibility for a site's condition is not clearly located within contracting arrangements, nor is it a topic of serious negotiation.

Thermal performance of a Concrete Cool Roof under different climatic conditions of Mexico

DOE PAGES

Hernández-Pérez, I.; Álvarez, G.; Gilbert, H.; ...

2014-11-27

A cool roof is an ordinary roof with a reflective coating on the exterior surface which has a high solar reflectance and high thermal emittance. These properties let the roof keep a lower temperature than a standard roof under the same conditions. In this work, the thermal performance of a concrete roof with and without insulation and with two colors has been analyzed using the finite volume method. The boundary conditions of the external roof surface were taken from hourly averaged climatic data of four cities. For the internal surface, it is considered that the building is air-conditioned and themore » inside air has a constant temperature. The interior surface temperature and the heat flux rates into the roofs were obtained for two consecutive days in order to assess the benefits of a cool roofs in different climates.« less

Energetics of Mg incorporation at GaN(0001) and GaN(0001¯) surfaces

NASA Astrophysics Data System (ADS)

Sun, Qiang; Selloni, Annabella; Myers, T. H.; Doolittle, W. Alan

2006-04-01

By using density functional calculations in the generalized gradient approximation, we investigate the energetics of Mg adsorption and incorporation at GaN(0001) and GaN(0001¯) surfaces under various Ga and Mg coverage conditions as well as in presence of light or electron beam-induced electronic excitation. We find significant differences in Mg incorporation between Ga- and N-polar surfaces. Mg incorporation is easier at the Ga-polar surface, but high Mg coverages are found to cause important distortions which locally change the polarity from Ga to N polar. At the N-rich and moderately Ga-rich GaN(0001) surface, 0.25 ML of Mg substituting Ga in the top bilayer strongly reduce the surface diffusion barriers of Ga and N adatoms, in agreement with the surfactant effect observed in experiments. As the Mg coverage exceeds 0.5 ML, partial incorporation in the subsurface region (second bilayer) becomes favorable. A surface structure with 0.5 ML of incorporated Mg in the top bilayer and 0.25 ML in the second bilayer is found to be stable over a wide range of Ga chemical potential. At the Ga bilayer-terminated GaN(0001) surface, corresponding to Ga-rich conditions, configurations where Mg is incorporated in the interface region between the metallic Ga bilayer and the underlying GaN bilayer appear to be favored. At the N-polar surface, Mg is not incorporated under N-rich or moderately Ga-rich conditions, whereas incorporation in the adlayer may take place under Ga-rich conditions. In the presence of light or electron beam induced excitation, energy differences between Mg incorporated at the surface and in deeper layers are reduced so that the tendency toward surface segregation is also reduced.

Integrating Hydrogeological, Microbiological, and Geochemical Data Using a Multi-Component Reactive Transport Model: Quantifying the Biogeochemical Evolution of Redox Zones in a Contaminated Aquifer

NASA Astrophysics Data System (ADS)

McGuire, J. T.; Phanikumar, M. S.; Long, D. T.; Hyndman, D. W.

2003-12-01

Hydrogeological, microbiological, and geochemical processes operating in a shallow sandy aquifer contaminated by waste fuels and chlorinated solvents were integrated using high-resolution mechanistic models. A 3-D, transient, reactive transport model was developed to quantitatively describe coupled processes via thermodynamic and kinetic arguments. The model was created by linking the hydrodynamic model MODFLOW (McDonald and Harbaugh, 1988), with advection, dispersion and user defined kinetic reactions based on RT3D 2.0, (Clement and Jones, 1998) and geochemical model PHREEQC (Parkhurst and Appelo, 1999). This model, BGTK3D 2.0, describes 1) the biodegradation of organic matter based on the influence of transport processes on microbial growth, 2) the complex suite of biogeochemical reactions operating in the aquifer, and 3) sharp chemical gradients. Some key features of this model are an ability to incorporate realistic solid phases to test hypotheses regarding mineral-water interactions, and an ability to accurately describe small-scale biogeochemical cycling (cm variability) observed in the field without oscillations or excessive numerical damping. BGTK3D was used to test hypotheses regarding the evolution of redox chemistry in a contaminated aquifer. The conceptual model that terminal electron accepting processes (TEAPs) distribute themselves sequentially into redox zones down flow path in aqueous systems is often used to interpret how and at what rates organic compounds will be degraded in the environment. Geochemical and microbiological data collected from a mixed contaminant plume at the former Wurtsmith AFB in Oscoda, Michigan suggests that under steady-state, mature plume conditions, traditional redox zonation may not be a realistic model of the distribution of TEAPs and therefore may not be the best model to evaluate the potential degradation of organic compounds. Based on these data, a conceptual model of TEAP evolution in contaminated systems was established. This model proposes that during initial plume development terminal electron acceptors O2, Fe3+, NO3, and SO4, are consumed sequentially based on thermodynamic arguments until a balance between organic degradation rates and source inputs and thus a stable plume length can be achieved. Once this "mature" state has been achieved, distinct redox zones can no longer be sustained and methanogenesis will dominate except in portions of the aquifer impacted by recharge water and diffusion of TEAs from all sides. Under these conditions, TEAPs will not proceed sequentially.

The effects of surface wettability on the fog and dew moisture harvesting performance on tubular surfaces

PubMed Central

Seo, Donghyun; Lee, Junghun; Lee, Choongyeop; Nam, Youngsuk

2016-01-01

The efficient water harvesting from air-laden moisture has been a subject of great interest to address world-wide water shortage issues. Recently, it has been shown that tailoring surface wettability can enhance the moisture harvesting performance. However, depending on the harvesting condition, a different conclusion has often been reported and it remains unclear what type of surface wettability would be desirable for the efficient water harvesting under the given condition. Here we compare the water harvesting performance of the surfaces with various wettability under two different harvesting conditions–dewing and fogging, and show that the different harvesting efficiency of each surface under these two conditions can be understood by considering the relative importance of the water capturing and removal efficiency of the surface. At fogging, the moisture harvesting performance is determined by the water removal efficiency of the surface with the oil-infused surfaces exhibiting the best performance. Meanwhile, at dewing, both the water capturing and removal efficiency are crucial to the harvesting performance. And well-wetting surfaces with a lower barrier to nucleation of condensates exhibit a better harvesting performance due to the increasing importance of the water capture efficiency over the water removal efficiency at dewing. PMID:27063149

Molecular simulation study of feruloyl esterase adsorption on charged surfaces: effects of surface charge density and ionic strength.

PubMed

Liu, Jie; Peng, Chunwang; Yu, Gaobo; Zhou, Jian

2015-10-06

The surrounding conditions, such as surface charge density and ionic strength, play an important role in enzyme adsorption. The adsorption of a nonmodular type-A feruloyl esterase from Aspergillus niger (AnFaeA) on charged surfaces was investigated by parallel tempering Monte Carlo (PTMC) and all-atom molecular dynamics (AAMD) simulations at different surface charge densities (±0.05 and ±0.16 C·m(-2)) and ionic strengths (0.007 and 0.154 M). The adsorption energy, orientation, and conformational changes were analyzed. Simulation results show that whether AnFaeA can adsorb onto a charged surface is mainly controlled by electrostatic interactions between AnFaeA and the charged surface. The electrostatic interactions between AnFaeA and charged surfaces are weakened when the ionic strength increases. The positively charged surface at low surface charge density and high ionic strength conditions can maximize the utilization of the immobilized AnFaeA. The counterion layer plays a key role in the adsorption of AnFaeA on the negatively charged COOH-SAM. The native conformation of AnFaeA is well preserved under all of these conditions. The results of this work can be used for the controlled immobilization of AnFaeA.

Volatilization of pesticides from the bare soil surface: evaluation of the humidity effect.

PubMed

Schneider, Martina; Endo, Satoshi; Goss, Kai-Uwe

2013-01-01

Volatilization of pesticides from soils under dry conditions (water content below the permanent wilting point) can be significantly influenced by sorption to hydrated mineral surfaces. This sorption process strongly depends on the water activity, expressed as equilibrium relative humidity in the pore space of the soil, and on the available surface area of the hydrated minerals. In this study, the influence of different humidity regimes on the volatilization of two pesticides (triallate and trifluralin) was demonstrated with a bench-scale wind tunnel system that allowed the establishment of well controlled humidity conditions within the soil. In the experiment starting with very dry conditions, increasing the relative humidity in the adjacent air from 60 to 85% resulted in an up to 8 times higher volatilization rate of the pesticides. An additional strong increase in volatilization (up to 3 times higher) was caused by a simulated rain event, which eliminates all sorption sites associated to mineral surfaces. In agreement with this interpretation, the comparison of two soils suggested that mineral surface area was the soil property that governs the volatilization under dry conditions, whereas soil organic matter was the controlling variable under wet conditions. In contrast to expectations, the use of a novel capsulated suspension for triallate showed the same humidity effects and no substantially lower volatilization rates in comparison to the regular formulation. This study demonstrated that humidity effects on pesticide volatilization can be interpreted via the mechanism of sorption to mineral surfaces under dry conditions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The Role of the Persian Gulf in Shaping Southwest Asian Surface Climate

NASA Astrophysics Data System (ADS)

Pal, J. S.; Eltahir, E. A. B.

2015-12-01

Summer surface climate of the Persian Gulf region is characterized by hot and humid conditions. Despite such conditions - which in other regions tends to trigger moist convection - typically this region experiences clear sky conditions and very little rainfall in the summer. In this study, we customize the MIT Regional Climate Model specifically for the Southwest Asia region and apply it at a 25-km grid spacing using reanalysis boundary conditions for present-day climate (1975-2005). Specific customizations include accurate representations of surface albedo and emissivity as well as mineral dust processes, all of which improve model bias. To assess the role of the Persian Gulf in shaping the region's climate, a 30-year experiment is performed without the Persian Gulf characterized. Results suggest that observed conditions over the Persian Gulf are due to a combination of physical processes involving adiabatic and diabatic descent. First, virtually clear sky conditions, due to subsidence during summer associated with the rising air motion over the monsoon region to the east, suppress upward motion and deep convection and increase incoming solar radiation. Second, the low surface albedo of the Persian Gulf results in enhanced absorption of solar radiation and total heat flux. Third, high evaporation rates increase water vapor, and therefore trap heat at the surface via the greenhouse effect for water vapor. Fourth, the relatively shallow boundary layer over the Persian Gulf concentrates water vapor and heat close to the surface. These combined factors maximize the total flux of heat in the boundary layer and hence moist static energy over the Persian Gulf.

Soil moisture sensing with aircraft observations of the diurnal range of surface temperature

NASA Technical Reports Server (NTRS)

Schmugge, T. J.; Blanchard, B.; Anderson, A.; Wang, V.

1977-01-01

Aircraft observations of the surface temperature were made by measurements of the thermal emission in the 8-14 micrometers band over agricultural fields around Phoenix, Arizona. The diurnal range of these surface temperature measurements were well correlated with the ground measurement of soil moisture in the 0-2 cm layer. The surface temperature observations for vegetated fields were found to be within 1 or 2 C of the ambient air temperature indicating no moisture stress. These results indicate that for clear atmospheric conditions remotely sensed surface temperatures are a reliable indicator of soil moisture conditions and crop status.

Stability diagrams for the surface patterns of GaN(0001bar) as a function of Schwoebel barrier height

NASA Astrophysics Data System (ADS)

Krzyżewski, Filip; Załuska-Kotur, Magdalena A.

2017-01-01

Height and type of Schwoebel barriers (direct or inverse) decides about the character of the surface instability. Different surface morphologies are presented. Step bunches, double steps, meanders, mounds and irregular patterns emerge at the surface as a result of step (Schwoebel) barriers at some temperature or miscut values. The study was carried out on the two-component kinetic Monte Carlo (kMC) model of GaN(0001bar) surface grown in nitrogen rich conditions. Diffusion of gallium adatoms over N-polar surface is slow and nitrogen adatoms are almost immobile. We show that in such conditions surfaces remain smooth when gallium adatoms diffuse in the presence of low inverse Schwoebel barrier. It is illustrated by adequate stability diagrams for surface morphologies.

A Volcanic Environment for Bedrock Diagenesis at Meridiani Planum, Mars

NASA Astrophysics Data System (ADS)

Hynek, B. M.; McCollom, T. M.

2005-12-01

Exposed bedrocks at Meridiani Planum on Mars display chemical and mineralogical evidence suggesting interaction with liquid water. Based on the observed bedding morphology, crystal vugs, varying Br:Cl ratios, as well as high abundances of hematite and sulfate minerals, the rocks have been interpreted by the Mars Exploration Rover (MER) team as sedimentary/evaporite deposits. However, the composition of the Meridiani bedrocks indicates that the formation model advocated by the MER team is not plausible. If the sulfates were attributable to precipitation of salts from an evaporating brine the rocks would be enriched in a balancing cation (e.g., Ca, Mg, or Fe) but this is not observed. Ratios of cations including Fe, Mg, Ca, and Na to (Si + Al) in the rocks are nearly identical to the basaltic martian meteorite Shergotty, and also very similar to unweathered basaltic rocks at Meridiani and Gusev Crater. The compositional data strongly suggest that the Meridiani rocks represent typical martian basalt with a sulfur component added. Here, we propose an alternative model for diagenesis of Meridiani bedrock that involves deposition of volcanic ash followed by reaction with condensed SO2- and H2O-bearing vapors in a solfatara-like setting. We suggest that volcanic deposition may account for the textures observed in Meridiani rocks since morphologic bedding features including sorted grains, planar bedding, low-angle cross-stratification, festoon bedding, and ripple lamination are common in base surge deposits of ash on Earth. The lath-shaped vugs may be the remains of ferrous sulfates (or mixed Fe-Mg-Ca sulfates) formed in the early stages of alteration that became unstable during oxidation. Widely varying Br:Cl ratios are also common in solfatara environments on Earth. In this scenario, most of the alteration of the rocks likely occurred at high temperatures (~100° C or higher), possibly soon after the volcaniclastic deposits were emplaced and still retained their original heat. Extended periods of time, a standing body of water, and clement conditions would not have been required for completion of the hypothesized diagenetic sequence.

The stress shadow effect: a mechanical analysis of the evenly-spaced parallel strike-slip faults in the San Andreas fault system

NASA Astrophysics Data System (ADS)

Zuza, A. V.; Yin, A.; Lin, J. C.

2015-12-01

Parallel evenly-spaced strike-slip faults are prominent in the southern San Andreas fault system, as well as other settings along plate boundaries (e.g., the Alpine fault) and within continental interiors (e.g., the North Anatolian, central Asian, and northern Tibetan faults). In southern California, the parallel San Jacinto, Elsinore, Rose Canyon, and San Clemente faults to the west of the San Andreas are regularly spaced at ~40 km. In the Eastern California Shear Zone, east of the San Andreas, faults are spaced at ~15 km. These characteristic spacings provide unique mechanical constraints on how the faults interact. Despite the common occurrence of parallel strike-slip faults, the fundamental questions of how and why these fault systems form remain unanswered. We address this issue by using the stress shadow concept of Lachenbruch (1961)—developed to explain extensional joints by using the stress-free condition on the crack surface—to present a mechanical analysis of the formation of parallel strike-slip faults that relates fault spacing and brittle-crust thickness to fault strength, crustal strength, and the crustal stress state. We discuss three independent models: (1) a fracture mechanics model, (2) an empirical stress-rise function model embedded in a plastic medium, and (3) an elastic-plate model. The assumptions and predictions of these models are quantitatively tested using scaled analogue sandbox experiments that show that strike-slip fault spacing is linearly related to the brittle-crust thickness. We derive constraints on the mechanical properties of the southern San Andreas strike-slip faults and fault-bounded crust (e.g., local fault strength and crustal/regional stress) given the observed fault spacing and brittle-crust thickness, which is obtained by defining the base of the seismogenic zone with high-resolution earthquake data. Our models allow direct comparison of the parallel faults in the southern San Andreas system with other similar strike-slip fault systems, both on Earth and throughout the solar system (e.g., the Tiger Stripe Fractures on Enceladus).

Spatial variability in the response of surface-water extent to climate extremes across the Prairie Pothole Region and adjacent Northern Prairie, United States

NASA Astrophysics Data System (ADS)

Vanderhoof, M.; Lane, C.; McManus, M.; Alexander, L. C.; Christensen, J.

2017-12-01

Surface-water extent, duration and movement will depend not only on climatic inputs but also the relative importance of different hydrologic pathways (e.g., surface storage, infiltration, evapotranspiration, stream outflows). We mapped surface-water extent from historic drought years to historic wet years spanning 1985 - 2015 across eleven Landsat path/rows representing the Prairie Pothole Region (PPR) and adjacent Northern Prairie of the United States. The PPR not only experienced a greater surface water extent under median conditions (2.6 times more) relative to the adjacent Northern Prairie, but showed a greater difference between drought and deluge conditions as well (range averaged 8.5 ha surface water km-2 relative to 2.5 ha surface water km-2 for the PPR and Northern Prairie, respectively). To explain the spatial variability in the amount of surface water expansion and contraction we used a two-stage modeling approach. First, surface-water extent was regressed on accumulated water availability (precipitation minus potential evapotranspiration). The slope of surface-water extent to climate inputs (per watershed) was our dependent variable in the second stage. That slope was regressed against independent variables representing hydrology-related landscape characteristics (e.g., infiltration capacity, surface storage capacity, stream density). Stream-connected surface water can leave via stream flow, influencing the rate at which surface-water may leave a location, therefore stream-connected and disconnected surface water were analyzed separately. Stream-connected surface water responded more strongly to wetter climatic conditions (i.e., accumulated) in landscapes with more lakes and less artificial drainage (e.g., ditching, tile drainage). Disconnected surface water responded more strongly to wetter climatic conditions when landscapes contained greater wetland density, fewer streams and a lower predicted rate of infiltration. From these findings, we can expect that the relationship between upstream and downstream waters will require consideration of hydrology-related landscape characteristics, and that climate-change related shifts in precipitation and evaporative demand will have an uneven effect on surface water expansion and contraction across the landscape.

Modified Balance Error Scoring System (M-BESS) test scores in athletes wearing protective equipment and cleats.

PubMed

Azad, Aftab Mohammad; Al Juma, Saad; Bhatti, Junaid Ahmad; Delaney, J Scott

2016-01-01

Balance testing is an important part of the initial concussion assessment. There is no research on the differences in Modified Balance Error Scoring System (M-BESS) scores when tested in real world as compared to control conditions. To assess the difference in M-BESS scores in athletes wearing their protective equipment and cleats on different surfaces as compared to control conditions. This cross-sectional study examined university North American football and soccer athletes. Three observers independently rated athletes performing the M-BESS test in three different conditions: (1) wearing shorts and T-shirt in bare feet on firm surface (control); (2) wearing athletic equipment with cleats on FieldTurf; and (3) wearing athletic equipment with cleats on firm surface. Mean M-BESS scores were compared between conditions. 60 participants were recruited: 39 from football (all males) and 21 from soccer (11 males and 10 females). Average age was 21.1 years (SD=1.8). Mean M-BESS scores were significantly lower (p<0.001) for cleats on FieldTurf (mean=26.3; SD=2.0) and for cleats on firm surface (mean=26.6; SD=2.1) as compared to the control condition (mean=28.4; SD=1.5). Females had lower scores than males for cleats on FieldTurf condition (24.9 (SD=1.9) vs 27.3 (SD=1.6), p=0.005). Players who had taping or bracing on their ankles/feet had lower scores when tested with cleats on firm surface condition (24.6 (SD=1.7) vs 26.9 (SD=2.0), p=0.002). Total M-BESS scores for athletes wearing protective equipment and cleats standing on FieldTurf or a firm surface are around two points lower than M-BESS scores performed on the same athletes under control conditions.

Modified Balance Error Scoring System (M-BESS) test scores in athletes wearing protective equipment and cleats

PubMed Central

Azad, Aftab Mohammad; Al Juma, Saad; Bhatti, Junaid Ahmad; Delaney, J Scott

2016-01-01

Background Balance testing is an important part of the initial concussion assessment. There is no research on the differences in Modified Balance Error Scoring System (M-BESS) scores when tested in real world as compared to control conditions. Objective To assess the difference in M-BESS scores in athletes wearing their protective equipment and cleats on different surfaces as compared to control conditions. Methods This cross-sectional study examined university North American football and soccer athletes. Three observers independently rated athletes performing the M-BESS test in three different conditions: (1) wearing shorts and T-shirt in bare feet on firm surface (control); (2) wearing athletic equipment with cleats on FieldTurf; and (3) wearing athletic equipment with cleats on firm surface. Mean M-BESS scores were compared between conditions. Results 60 participants were recruited: 39 from football (all males) and 21 from soccer (11 males and 10 females). Average age was 21.1 years (SD=1.8). Mean M-BESS scores were significantly lower (p<0.001) for cleats on FieldTurf (mean=26.3; SD=2.0) and for cleats on firm surface (mean=26.6; SD=2.1) as compared to the control condition (mean=28.4; SD=1.5). Females had lower scores than males for cleats on FieldTurf condition (24.9 (SD=1.9) vs 27.3 (SD=1.6), p=0.005). Players who had taping or bracing on their ankles/feet had lower scores when tested with cleats on firm surface condition (24.6 (SD=1.7) vs 26.9 (SD=2.0), p=0.002). Conclusions Total M-BESS scores for athletes wearing protective equipment and cleats standing on FieldTurf or a firm surface are around two points lower than M-BESS scores performed on the same athletes under control conditions. PMID:27900181

Investigation of aerosol indirect effects on simulated flash-flood heavy rainfall over Korea

NASA Astrophysics Data System (ADS)

Lim, Kyo-Sun Sunny; Hong, Song-You

2012-11-01

This study investigates aerosol indirect effects on the development of heavy rainfall near Seoul, South Korea, on 12 July 2006, focusing on precipitation amount. The impact of the aerosol concentration on simulated precipitation is evaluated by varying the initial cloud condensation nuclei (CCN) number concentration in the Weather Research and Forecasting (WRF) Double-Moment 6-class (WDM6) microphysics scheme. The simulations are performed under clean, semi-polluted, and polluted conditions. Detailed analysis of the physical processes that are responsible for surface precipitation, including moisture and cloud microphysical budgets shows enhanced ice-phase processes to be the primary driver of increased surface precipitation under the semi-polluted condition. Under the polluted condition, suppressed auto-conversion and the enhanced evaporation of rain cause surface precipitation to decrease. To investigate the role of environmental conditions on precipitation response under different aerosol number concentrations, a set of sensitivity experiments are conducted with a 5 % decrease in relative humidity at the initial time, relative to the base simulations. Results show ice-phase processes having small sensitivity to CCN number concentration, compared with the base simulations. Surface precipitation responds differently to CCN number concentration under the lower humidity initial condition, being greatest under the clean condition, followed by the semi-polluted and polluted conditions.

Thickened boundary layer theory for air film drag reduction on a van body surface

NASA Astrophysics Data System (ADS)

Xie, Xiaopeng; Cao, Lifeng; Huang, Heng

2018-05-01

To elucidate drag reduction mechanism on a van body surface under air film condition, a thickened boundary layer theory was proposed and a frictional resistance calculation model of the van body surface was established. The frictional resistance on the van body surface was calculated with different parameters of air film thickness. In addition, the frictional resistance of the van body surface under the air film condition was analyzed by computational fluid dynamics (CFD) simulation and different air film states that influenced the friction resistance on the van body surface were discussed. As supported by the CFD simulation results, the thickened boundary layer theory may provide reference for practical application of air film drag reduction on a van body surface.

Influence of Surface Properties and Impact Conditions on Adhesion of Insect Residues

NASA Technical Reports Server (NTRS)

Wohl, Christopher J.; Smith, Joseph G.; Connell, John W.; Siochi, Emilie J.; Doss, Jereme R.; Shanahan, Michelle H.; Penner, Ronald K.

2015-01-01

Insect residues can cause premature transition to turbulent flow on laminar flow airfoils. Engineered surfaces that mitigate the adhesion of insect residues provide, therefore, a route to more efficient aerodynamics and reduced fuel burn rates. Areal coverage and heights of residues depend not only on surface properties, but also on impact conditions. We report high speed photography of fruit fly impacts at different angles of inclination on a rigid aluminum surface, optical microscopy and profilometry, and contact angle goniometry to support the design of engineered surfaces. For the polyurethane and epoxy coatings studied, some of which exhibited superhydrophobicity, it was determined that impact angle and surface compositions play critical roles in the efficacy of these surfaces to reduce insect residue adhesion.

Solution of the surface Euler equations for accurate three-dimensional boundary-layer analysis of aerodynamic configurations

NASA Technical Reports Server (NTRS)

Iyer, V.; Harris, J. E.

1987-01-01

The three-dimensional boundary-layer equations in the limit as the normal coordinate tends to infinity are called the surface Euler equations. The present paper describes an accurate method for generating edge conditions for three-dimensional boundary-layer codes using these equations. The inviscid pressure distribution is first interpolated to the boundary-layer grid. The surface Euler equations are then solved with this pressure field and a prescribed set of initial and boundary conditions to yield the velocities along the two surface coordinate directions. Results for typical wing and fuselage geometries are presented. The smoothness and accuracy of the edge conditions obtained are found to be superior to the conventional interpolation procedures.

The effect of root surface conditioning on smear layer removal in periodontal regeneration (a scanning electron microscopic study)

NASA Astrophysics Data System (ADS)

Fidyawati, D.; Soeroso, Y.; Masulili, S. L. C.

2017-08-01

The role of root surface conditioning treatment on smear layer removal of human teeth is affected by periodontitis in periodontal regeneration. The objective of this study is to analyze the smear layer on root surface conditioned with 2.1% minocycline HCl ointment (Periocline), and 24% EDTA gel (Prefgel). A total of 10 human teeth indicated for extraction due to chronic periodontitis were collected and root planed. The teeth were sectioned in thirds of the cervical area, providing 30 samples that were divided into three groups - minocycline ointment treatment, 24% EDTA gel treatment, and saline as a control. The samples were examined by scanning electron microscope. No significant differences in levels of smear layer were observed between the minocycline group and the EDTA group (p=0.759). However, there were significant differences in the level of smear layer after root surface treatment in the minocycline and EDTA groups, compared with the control group (p=0.00). There was a relationship between root surface conditioning treatment and smear layer levels following root planing.

Potential contribution of microbial degradation to natural attenuation of MTBE in surface water systems

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

2001-01-01

The potential contribution of in situ biodegradation as a mechanism for natural attenuation of MTBE in surface water was studied. Surface water sediments from streams and lakes at 11 sites throughout the US. Microbial degradation of [U-14C] MTBE was observed in surface-water-sediment microcosms under anaerobic conditions, but the efficiency and products of anaerobic MTBE biodegradation were strongly dependent on the predominant terminal electron accepting conditions. In the presence of substantial methanogenic activity, MTBE biodegradation was nominal and involved reduction of MTBE to t-butanol (TBA). Under more oxidizing conditions, minimal accumulation of 14C-TBA and significant mineralization of [U-14C] MTBE to 14CO2 were observed. Microorganisms inhabiting the bed sediments of streams and lakes could degrade MTBE effectively under a range of anaerobic terminal electron accepting conditions. Thus, anaerobic bed sediment microbial processes also might contribute to natural attenuation of MTBE in surface water systems throughout the US. This is an abstract of a paper presented at the 222nd ACS National Meting (Chicago, IL 8/26-30/2001).

Human skin surface evaluation by image processing

NASA Astrophysics Data System (ADS)

Zhu, Liangen; Zhan, Xuemin; Xie, Fengying

2003-12-01

Human skin gradually lose its tension and becomes very dry as time flies by. Use of cosmetics is effective to prevent skin aging. Recently, there are many choices of products of cosmetics. To show their effects, It is desirable to develop a way to evaluate quantificationally skin surface condition. In this paper, An automatic skin evaluating method is proposed. The skin surface has the pattern called grid-texture. This pattern is composed of the valleys that spread vertically, horizontally, and obliquely and the hills separated by them. Changes of the grid are closely linked to the skin surface condition. They can serve as a good indicator for the skin condition. By measuring the skin grid using digital image processing technologies, we can evaluate skin surface about its aging, health, and alimentary status. In this method, the skin grid is first detected to form a closed net. Then, some skin parameters such as Roughness, tension, scale and gloss can be calculated from the statistical measurements of the net. Through analyzing these parameters, the condition of the skin can be monitored.

Influence of boundary conditions on the existence and stability of minimal surfaces of revolution made of soap films

NASA Astrophysics Data System (ADS)

Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

2014-09-01

Because of surface tension, soap films seek the shape that minimizes their surface energy and thus their surface area. This mathematical postulate allows one to predict the existence and stability of simple minimal surfaces. After briefly recalling classical results obtained in the case of symmetric catenoids that span two circular rings with the same radius, we discuss the role of boundary conditions on such shapes, working with two rings having different radii. We then investigate the conditions of existence and stability of other shapes that include two portions of catenoids connected by a planar soap film and half-symmetric catenoids for which we introduce a method of observation. We report a variety of experimental results including metastability—an hysteretic evolution of the shape taken by a soap film—explained using simple physical arguments. Working by analogy with the theory of phase transitions, we conclude by discussing universal behaviors of the studied minimal surfaces in the vicinity of their existence thresholds.

Probing Pluto's underworld: Ice temperatures from microwave radiometry decoupled from surface conditions

NASA Astrophysics Data System (ADS)

Leyrat, Cedric; Lorenz, Ralph D.; Le Gall, Alice

2016-04-01

Present models admit a wide range of 2015 surface conditions at Pluto and Charon, where the atmospheric pressure may undergo dramatic seasonal variation and for which measurements are imminent from the New Horizons mission. One anticipated observation is the microwave brightness temperature, heretofore anticipated as indicating surface conditions relevant to surface-atmosphere equilibrium. However, drawing on recent experience with Cassini observations at Iapetus and Titan, we call attention to the large electrical skin depth of outer Solar System materials such as methane, nitrogen or water ice, such that this observation may indicate temperatures averaged over depths of several or tens of meters beneath the surface. Using a seasonally-forced thermal model to determine microwave emission we predict that the southern hemisphere observations (in polar night) of New Horizons in July 2015 will suggest effective temperatures of ∼40 K, reflecting deep heat buried over the last century of summer, even if the atmospheric pressure suggests that the surface nitrogen frost point may be much lower.

Weathering of iron sulfides under Mars surface ambient conditions

NASA Technical Reports Server (NTRS)

Blackburn, T. R.

1981-01-01

The study of iron sulfide surface alternation reactions under Mars' surface ambient conditions begun during 1980 was extended through improved irradiation design and experimental protocols. A wider range of humidities and more intense irradiation were incorporated in the study. X-ray photoelectron spectra of irradiated chips suggest formation of FeSO4, FeCO3, and an iron oxide on the iron sulfide substrates studied.