Workshop on Grid Generation and Related Areas

NASA Technical Reports Server (NTRS)

1992-01-01

A collection of papers given at the Workshop on Grid Generation and Related Areas is presented. The purpose of this workshop was to assemble engineers and scientists who are currently working on grid generation for computational fluid dynamics (CFD), surface modeling, and related areas. The objectives were to provide an informal forum on grid generation and related topics, to assess user experience, to identify needs, and to help promote synergy among engineers and scientists working in this area. The workshop consisted of four sessions representative of grid generation and surface modeling research and application within NASA LeRC. Each session contained presentations and an open discussion period.

Surface Habitat Systems

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.

2009-01-01

The Surface Habitat Systems (SHS) Focused Investment Group (FIG) is part of the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) effort to provide a focused direction and funding to the various projects that are working on human surface habitat designs and technologies for the planetary exploration missions. The overall SHS-FIG effort focuses on directing and guiding those projects that: 1) develop and demonstrate new surface habitat system concepts, innovations, and technologies to support human exploration missions, 2) improve environmental systems that interact with human habitats, 3) handle and emplace human surface habitats, and 4) focus on supporting humans living and working in habitats on planetary surfaces. The activity areas of the SHS FIG described herein are focused on the surface habitat project near-term objectives as described in this document. The SHS-FIG effort focuses on mitigating surface habitat risks (as identified by the Lunar Surface Systems Project Office (LSSPO) Surface Habitat Element Team; and concentrates on developing surface habitat technologies as identified in the FY08 gap analysis. The surface habitat gap assessment will be updated annually as the surface architecture and surface habitat definition continues to mature. These technologies are mapped to the SHS-FIG Strategic Development Roadmap. The Roadmap will bring to light the areas where additional innovative efforts are needed to support the development of habitat concepts and designs and the development of new technologies to support of the LSSPO Habitation Element development plan. Three specific areas of development that address Lunar Architecture Team (LAT)-2 and Constellation Architecture Team (CxAT) Lunar habitat design issues or risks will be focused on by the SHS-FIG. The SHS-FIG will establish four areas of development that will help the projects prepare in their planning for surface habitat systems development. Those development areas are the 1) surface habitat concept definition, 2) inflatable surface habitat development, and 3) autonomous habitat operations, and 4) cross-cutting / systems engineering. In subsequent years, the SHS-FIG will solicit a call for innovations and technologies that will support the development of these four development areas. The other development areas will be assessed yearly and identified on the SHS-FIG s Strategic Development Roadmap. Initial investment projects that are funded by the Constellation Program Office (CxPO), LSSPO, or the Exploration Technology Development Projects (ETDP) will also be included on the Roadmap. For example, in one or two years from now, the autonomous habitat operations and testbed would collaborations with the Integrated Systems Health Management (ISHM) and Automation for Operations ETDP projects, which will give the surface habitat projects an integrated habitat autonomy testbed to test software and systems. The SHS-FIG scope is to provide focused direction for multiple innovations, technologies and subsystems that are needed to support humans at a remote planetary surface habitat during the concept development, design definition, and integration phases of that project. Subsystems include: habitability, lightweight structures, power management, communications, autonomy, deployment, outfitting, life support, wireless connectivity, lighting, thermal and more.

Water resources of Lincoln County coastal area, Oregon

USGS Publications Warehouse

Frank, F.J.; Laenen, Antonius

1976-01-01

Water supplies for all municipalities in Lincoln County currently (1975) are obtained from surface-water sources. Because of rapid economic development of the coastal area, it is expected that additional water will be needed in the future. Additional water can be supplied (1) by reservoirs on major streams; (2) by the expansion, in some locations, of present surface-water facilities on small streams; and (3) locally, by an additional small volume of supplemental water from ground-water sources.

Characterizing the fabric of the urban environment: A case study of Salt Lake City, Utah

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

Akbari, Hashem; Rose, L. Shea

2001-02-28

Urban fabric data are needed in order to estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city, and to design effective implementation programs. In this report, we discuss the result of a semi-automatic Monte-Carlo statistical approach used to develop data on surface-type distribution and city-fabric makeup (percentage of various surface-types) using aerial color orthophotography. The digital aerial photographs for Salt Lake City covered a total of about 34 km2 (13 mi2). At 0.50-m resolution, there were approximately 1.4 x 108 pixels of data. Four majormore » land-use types were examined: (1) commercial, (2) industrial, (3) educational, and (4) residential. On average, for the areas studied, vegetation covers about 46 percent of the area (ranging 44-51 percent), roofs cover about 21 percent (ranging 15-24 percent), and paved surfaces about 26 percent (ranging 21-28 percent). For the most part, trees shade streets, parking lots, grass, and sidewalks. In most non-residential areas, paved surfaces cover 46-66 percent of the area. In residential areas, on average, paved surfaces cover about 32 percent of the area. Land-use/land-cover (LU/LC) data from the United States Geological Survey were used to extrapolate these results from neighborhood scales to metropolitan Salt Lake City. In an area of roughly 560 km2, defining most of metropolitan Salt Lake City, over 60 percent is residential. The total roof area is about 110 km2, and the total paved surface area (roads, parking areas, sidewalks) covers about 170 km2. The total vegetated area covers about 230 km2.« less

Development and Testing of High Surface Area Iridium Anodes for Molten Oxide Electrolysis

NASA Technical Reports Server (NTRS)

Shchetkovskiy, Anatoliy; McKechnie, Timothy; Sadoway, Donald R.; Paramore, James; Melendez, Orlando; Curreri, Peter A.

2010-01-01

Processing of lunar regolith into oxygen for habitat and propulsion is needed to support future space missions. Direct electrochemical reduction of molten regolith is an attractive method of processing, because no additional chemical reagents are needed. The electrochemical processing of molten oxides requires high surface area, inert anodes. Such electrodes need to be structurally robust at elevated temperatures (1400-1600?C), be resistant to thermal shock, have good electrical conductivity, be resistant to attack by molten oxide (silicate), be electrochemically stable and support high current density. Iridium with its high melting point, good oxidation resistance, superior high temperature strength and ductility is the most promising candidate for anodes in high temperature electrochemical processes. Several innovative concepts for manufacturing such anodes by electrodeposition of iridium from molten salt electrolyte (EL-Form? process) were evaluated. Iridium electrodeposition to form of complex shape components and coating was investigated. Iridium coated graphite, porous iridium structure and solid iridium anodes were fabricated. Testing of electroformed iridium anodes shows no visible degradation. The result of development, manufacturing and testing of high surface, inert iridium anodes will be presented.

Development and Testing of High Surface Area Iridium Anodes for Molten Oxide Electrolysis

NASA Technical Reports Server (NTRS)

Shchetkovskiy, Anatoliy; McKechnie, Timothy; Sadoway, Donald R.; Paramore, James; Melendez, Orlando; Curreri, Peter A.

2010-01-01

Processing of lunar regolith into oxygen for habitat and propulsion is needed to support future space missions. Direct electrochemical reduction of molten regolith is an attractive method of processing, because no additional chemical reagents are needed. The electrochemical processing of molten oxides requires high surface area, inert anodes. Such electrodes need to be structurally robust at elevated temperatures (1400-1600 C), be resistant to thermal shock, have good electrical conductivity, be resistant to attack by molten oxide (silicate), be electrochemically stable and support high current density. Iridium with its high melting point, good oxidation resistance, superior high temperature strength and ductility is the most promising candidate for anodes in high temperature electrochemical processes. Several innovative concepts for manufacturing such anodes by electrodeposition of iridium from molten salt electrolyte (EL-Form process) were evaluated. Iridium electrodeposition to form of complex shape components and coating was investigated. Iridium coated graphite, porous iridium structure and solid iridium anodes were fabricated. Testing of electroformed iridium anodes shows no visible degradation. The result of development, manufacturing and testing of high surface, inert iridium anodes will be presented.

Estimating home-range size: when to include a third dimension?

PubMed Central

Monterroso, Pedro; Sillero, Neftalí; Rosalino, Luís Miguel; Loureiro, Filipa; Alves, Paulo Célio

2013-01-01

Most studies dealing with home ranges consider the study areas as if they were totally flat, working only in two dimensions, when in reality they are irregular surfaces displayed in three dimensions. By disregarding the third dimension (i.e., topography), the size of home ranges underestimates the surface actually occupied by the animal, potentially leading to misinterpretations of the animals' ecological needs. We explored the influence of considering the third dimension in the estimation of home-range size by modeling the variation between the planimetric and topographic estimates at several spatial scales. Our results revealed that planimetric approaches underestimate home-range size estimations, which range from nearly zero up to 22%. The difference between planimetric and topographic estimates of home-ranges sizes produced highly robust models using the average slope as the sole independent factor. Moreover, our models suggest that planimetric estimates in areas with an average slope of 16.3° (±0.4) or more will incur in errors ≥5%. Alternatively, the altitudinal range can be used as an indicator of the need to include topography in home-range estimates. Our results confirmed that home-range estimates could be significantly biased when topography is disregarded. We suggest that study areas where home-range studies will be performed should firstly be scoped for its altitudinal range, which can serve as an indicator for the need for posterior use of average slope values to model the surface area used and/or available for the studied animals. PMID:23919170

Tilling the Soil of the European Higher Education Area

ERIC Educational Resources Information Center

Burnett, John

2007-01-01

The Bologna Process presents both opportunities and challenges for teachers in the European area. As tensions surface between different forms of national legislation, accreditation and quality assurance, projects need to be developed that model ways of resolving problems within a European context. Utilising their links and network of contacts…

Metabolic rate M  0.75 in human beings

NASA Astrophysics Data System (ADS)

Agrawal, D. C.

2014-11-01

Human beings consume energy every day. Even at rest, energy is still needed for the working of the internal organs. This is achieved by the metabolism of consumed food in the presence of inhaled oxygen. During the resting state this is called the maintenance rate, and follows the mouse-to-elephant formula, Pmet = 70M0.75 kcal per day. Here, M is the body mass of the subject in kilograms. The heat generated in metabolism is lost through the body surface of the subject, so the metabolic rate should also be proportional to the body surface area. In other words, the body surface area in the case of a human being must also depend on M0.75. The present paper examines this issue by finding a relationship between human body surface area and its mass through a very simple model that can be easily understood and verified by physics students, who can also compare it with all the expressions for body surface area available in the literature. This will build confidence in the students that the heat generated from metabolism in fact dissipates through the surface of the body.

Active microwave remote sensing research program plan. Recommendations of the Earth Resources Synthetic Aperture Radar Task Force. [application areas: vegetation canopies, surface water, surface morphology, rocks and soils, and man-made structures

NASA Technical Reports Server (NTRS)

1980-01-01

A research program plan developed by the Office of Space and Terrestrial Applications to provide guidelines for a concentrated effort to improve the understanding of the measurement capabilities of active microwave imaging sensors, and to define the role of such sensors in future Earth observations programs is outlined. The focus of the planned activities is on renewable and non-renewable resources. Five general application areas are addressed: (1) vegetation canopies, (2) surface water, (3) surface morphology, (4) rocks and soils, and (5) man-made structures. Research tasks are described which, when accomplished, will clearly establish the measurement capabilities in each area, and provide the theoretical and empirical results needed to specify and justify satellite systems using imaging radar sensors for global observations.

Update of the Accounting Surface Along the Lower Colorado River

USGS Publications Warehouse

Wiele, Stephen M.; Leake, Stanley A.; Owen-Joyce, Sandra J.; McGuire, Emmet H.

2008-01-01

The accounting-surface method was developed in the 1990s by the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, to identify wells outside the flood plain of the lower Colorado River that yield water that will be replaced by water from the river. This method was needed to identify which wells require an entitlement for diversion of water from the Colorado River and need to be included in accounting for consumptive use of Colorado River water as outlined in the Consolidated Decree of the United States Supreme Court in Arizona v. California. The method is based on the concept of a river aquifer and an accounting surface within the river aquifer. The study area includes the valley adjacent to the lower Colorado River and parts of some adjacent valleys in Arizona, California, Nevada, and Utah and extends from the east end of Lake Mead south to the southerly international boundary with Mexico. Contours for the original accounting surface were hand drawn based on the shape of the aquifer, water-surface elevations in the Colorado River and drainage ditches, and hydrologic judgment. This report documents an update of the original accounting surface based on updated water-surface elevations in the Colorado River and drainage ditches and the use of simple, physically based ground-water flow models to calculate the accounting surface in four areas adjacent to the free-flowing river.

Evaluation of airborne lidar elevation surfaces for propagation of coastal inundation: the importance of hydrologic connectivity

USGS Publications Warehouse

Poppenga, Sandra K.; Worstell, Bruce B.

2015-01-01

Detailed information about coastal inundation is vital to understanding dynamic and populated areas that are impacted by storm surge and flooding. To understand these natural hazard risks, lidar elevation surfaces are frequently used to model inundation in coastal areas. A single-value surface method is sometimes used to inundate areas in lidar elevation surfaces that are below a specified elevation value. However, such an approach does not take into consideration hydrologic connectivity between elevation grids cells resulting in inland areas that should be hydrologically connected to the ocean, but are not. Because inland areas that should drain to the ocean are hydrologically disconnected by raised features in a lidar elevation surface, simply raising the water level to propagate coastal inundation will lead to inundation uncertainties. We took advantage of this problem to identify hydrologically disconnected inland areas to point out that they should be considered for coastal inundation, and that a lidar-based hydrologic surface should be developed with hydrologic connectivity prior to inundation analysis. The process of achieving hydrologic connectivity with hydrologic-enforcement is not new, however, the application of hydrologically-enforced lidar elevation surfaces for improved coastal inundation mapping as approached in this research is innovative. In this article, we propagated a high-resolution lidar elevation surface in coastal Staten Island, New York to demonstrate that inland areas lacking hydrologic connectivity to the ocean could potentially be included in inundation delineations. For inland areas that were hydrologically disconnected, we evaluated if drainage to the ocean was evident, and calculated an area exceeding 11 ha (~0.11 km2) that could be considered in inundation delineations. We also assessed land cover for each inland area to determine the type of physical surfaces that would be potentially impacted if the inland areas were considered as part of a coastal inundation. A visual analysis indicated that developed, medium intensity and palustrine forested wetland land cover types would be impacted for those locations. This article demonstrates that hydrologic connectivity is an important factor to consider when inundating a lidar elevation surface. This information is needed for inundation monitoring and management in sensitive coastal regions.

Beyond greening and browning: the need for an integrated understanding of Arctic change

NASA Astrophysics Data System (ADS)

Gamon, J. A.; Huemmrich, K. F.; Hmimina, G.; Yu, R.

2017-12-01

Satellite records and field observations povide contradictory evidence for "greening" or "browning" of Arctic tundra. Large-scale observations of apparent greening have been based on satellite vegetation indices (e.g NDVI). However, a clear interpretation of these trends are confounded by changing snow cover and surface hydrology, both of which influence NDVI and are known to be changing independently of any direct vegetation response. Field studies have demonstrated greening in some areas, but not others, and have also documented changing permafrost depth, surface hydrology and snow cover. Together, these confounding factors can explain some of the contradictory evidence based regarding greening and browning. Given the multiple influences on Arctic NDVI, simple conclusions regarding greening and browning from satellite data alone can be incorrect; when these confounding factors are taken into account, some areas that show apparent greening in the satellite record appear to be undergoing productivity declines due to surface drying. These contradictory interpretations have profound implications for our understanding of changing surface energy balance, biogeochemistry, and surface-atmosphere feedbacks. To better address Arctic ecosystem responses to a changing climate, an integrated, multi-scale, multivariate approach that considers hydrology, permafrost, snow cover and vegetation is needed.

Surface models for coupled modelling of runoff and sewer flow in urban areas.

PubMed

Ettrich, N; Steiner, K; Thomas, M; Rothe, R

2005-01-01

Traditional methods fail for the purpose of simulating the complete flow process in urban areas as a consequence of heavy rainfall and as required by the European Standard EN-752 since the bi-directional coupling between sewer and surface is not properly handled. The new methodology, developed in the EUREKA-project RisUrSim, solves this problem by carrying out the runoff on the basis of shallow water equations solved on high-resolution surface grids. Exchange nodes between the sewer and the surface, like inlets and manholes, are located in the computational grid and water leaving the sewer in case of surcharge is further distributed on the surface. Dense topographical information is needed to build a model suitable for hydrodynamic runoff calculations; in urban areas, in addition, many line-shaped elements like houses, curbs, etc. guide the runoff of water and require polygonal input. Airborne data collection methods offer a great chance to economically gather densely sampled input data.

Surface water areas significantly impacted 2014 dengue outbreaks in Guangzhou, China

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

Tian, Huaiyu; Huang, Shanqian

Dengue transmission in urban areas is strongly influenced by a range of biological and environmental factors, yet the key drivers still need further exploration. To better understand mechanisms of environment–mosquito–urban dengue transmission, we propose an empirical model parameterized and cross-validated from a unique dataset including viral gene sequences, vector dynamics and human dengue cases in Guangzhou, China, together with a 36-year urban environmental change maps investigated by spatiotemporal satellite image fusion. The dengue epidemics in Guangzhou are highly episodic and were not associated with annual rainfall over time. Our results indicate that urban environmental changes, especially variations in surface areamore » covered by water in urban areas, can substantially alter the virus population and dengue transmission. The recent severe dengue outbreaks in Guangzhou may be due to the surge in an artificial lake construction, which could increase infection force between vector (mainly Aedes albopictus) and host when urban water area significantly increased. Impacts of urban environmental change on dengue dynamics may not have been thoroughly investigated in the past studies and more work needs to be done to better understand the consequences of urbanization processes in our changing world. - Highlights: • Urban dengue outbreak is associated with water area in Guangzhou, 1978–2014. • Surface water area can alter population size of dengue virus in urban area. • Urban dengue outbreak is not associated with annual rainfall in Guangzhou. • Spatiotemporal satellite image fusion can investigate urban environmental change. • Urban environmental change could induce virus, vector, and dengue epidemic change.« less

Wastewater Treatment Methods

NASA Astrophysics Data System (ADS)

Smith, Dana; Williams, Fred; Moffatt, Scott

Alcoa's Point Comfort, Texas industrial facility is a combination of a bauxite refining plant utilizing the Bayer process and an aluminum fluoride production plant. Due to the location's use of dry stack technology for bauxite residue disposal, the pond surface areas for evaporation are minimal compared to the rainfall catchment areas. This results in the periodic need to reduce accumulated volumes of storm water at the Residue Disposal Area (RDA).

Proceedings of the 5th Symposium on applied surface analysis

NASA Astrophysics Data System (ADS)

Grant, J. T.

1984-04-01

The 5th Symposium on Applied Surface Analysis was held at the University of Dayton, 8-10 June 1983. This Symposium was held to meet a need, namely to show the transition between basic surface science research and applications of this research to areas of Department of Defense interest. Areas receiving special attention at this Symposium were chemical bonding and reactions at metal-semiconductors interfaces, surface analysis and the tribological processes of ion implanted materials, microbeam analysis and laser ionization of sputtered neutrals. Other topics discussed included adsorption, adhesion, corrosion, wear and thin films. Approximately 110 scientists active in the field of surface analysis participated in the Symposium. Four scientists presented invited papers at the Symposium. There were 29 contributed presentations. The proceedings of the Symposium are being published in a special issue of the journal, Applications of Surface Science, by North-Holland Publishing Company.

Wide-Area Soil Moisture Estimation Using the Propagation of Lightning Generated Low-Frequency Electromagnetic Signals 1977

USDA-ARS?s Scientific Manuscript database

Land surface moisture measurements are central to our understanding of the earth’s water system, and are needed to produce accurate model-based weather/climate predictions. Currently, there exists no in-situ network capable of estimating wide-area soil moisture. In this paper, we explore an alterna...

Regional potentiometric surface of the Ozark aquifer in Arkansas, Kansas, Missouri, and Oklahoma, November 2014–January 2015

USGS Publications Warehouse

Nottmeier, Anna M.

2015-12-21

The Ozark aquifer, within the Ozark Plateaus aquifer system (herein referred to as the “Ozark system”), is the primary groundwater source in the Ozark Plateaus physiographic province (herein referred to as the “Ozark Plateaus”) of Arkansas, Kansas, Missouri, and Oklahoma. Groundwater from the Ozark system has historically been an important part of the water resource base, and groundwater availability is a concern in some areas; dependency on the Ozark aquifer as a water supply has caused evolving, localized issues. The construction of a regional potentiometric-surface map of the Ozark aquifer is needed to aid assessment of current and future groundwater use and availability. The regional potentiometric-surface mapping is part of the U.S. Geological Survey (USGS) Groundwater Resources Program initiative (http://water.usgs.gov/ogw/gwrp/activities/regional.html) and the Ozark system groundwater availability project (http://ar.water.usgs.gov/ozarks), which seeks to quantify current groundwater resources, evaluate changes in these resources over time, and provide the information needed to simulate system response to future human-related and environmental stresses.The Ozark groundwater availability project objectives include assessing (1) growing demands for groundwater and associated declines in groundwater levels as agricultural, industrial, and public supply pumping increases to address needs; (2) regional climate variability and pumping effects on groundwater and surface-water flow paths; (3) effects of a gradual shift to a greater surface-water dependence in some areas; and (4) shale-gas production requiring groundwater and surface water for hydraulic fracturing. Data compiled and used to construct the regional Ozark aquifer potentiometric surface will aid in the assessment of those objectives.

Discovery of a Potent Free Fatty Acid 1 Receptor Agonist with Low Lipophilicity, Low Polar Surface Area, and Robust in Vivo Efficacy.

PubMed

Hansen, Steffen V F; Christiansen, Elisabeth; Urban, Christian; Hudson, Brian D; Stocker, Claire J; Due-Hansen, Maria E; Wargent, Ed T; Shimpukade, Bharat; Almeida, Reinaldo; Ejsing, Christer S; Cawthorne, Michael A; Kassack, Matthias U; Milligan, Graeme; Ulven, Trond

2016-03-24

The free fatty acid receptor 1 (FFA1 or GPR40) is established as an interesting potential target for treatment of type 2 diabetes. However, to obtain optimal ligands, it may be necessary to limit both lipophilicity and polar surface area, translating to a need for small compounds. We here describe the identification of 24, a potent FFA1 agonist with low lipophilicity and very high ligand efficiency that exhibit robust glucose lowering effect.

The influence of surface type on the absorbed radiation by a human under hot, dry conditions

NASA Astrophysics Data System (ADS)

Hardin, A. W.; Vanos, J. K.

2018-01-01

Given the predominant use of heat-retaining materials in urban areas, numerous studies have addressed the urban heat island mitigation potential of various "cool" options, such as vegetation and high-albedo surfaces. The influence of altered radiational properties of such surfaces affects not only the air temperature within a microclimate, but more importantly the interactions of long- and short-wave radiation fluxes with the human body. Minimal studies have assessed how cool surfaces affect thermal comfort via changes in absorbed radiation by a human ( R abs) using real-world, rather than modeled, urban field data. The purpose of the current study is to assess the changes in the absorbed radiation by a human—a critical component of human energy budget models—based on surface type on hot summer days (air temperatures > 38.5∘C). Field tests were conducted using a high-end microclimate station under predominantly clear sky conditions over ten surfaces with higher sky view factors in Lubbock, Texas. Three methods were used to measure and estimate R abs: a cylindrical radiation thermometer (CRT), a net radiometer, and a theoretical estimation model. Results over dry surfaces suggest that the use of high-albedo surfaces to reduce overall urban heat gain may not improve acute human thermal comfort in clear conditions due to increased reflected radiation. Further, the use of low-cost instrumentation, such as the CRT, shows potential in quantifying radiative heat loads within urban areas at temporal scales of 5-10 min or greater, yet further research is needed. Fine-scale radiative information in urban areas can aid in the decision-making process for urban heat mitigation using non-vegetated urban surfaces, with surface type choice is dependent on the need for short-term thermal comfort, or reducing cumulative heat gain to the urban fabric.

Coupling surface water (Delft3D) to groundwater (MODFLOW) in the Bay-Delta community model: the effect of major abstractions in the Delta

NASA Astrophysics Data System (ADS)

Hendriks, D.; Ball, S. M.; Van der Wegen, M.; Verkaik, J.; van Dam, A.

2016-12-01

We present a coupled groundwater-surface water model for the San Francisco Bay and Sacramento Valley that consists of a combination of a spatially-distributed groundwater model (Modflow) based on the USGS Central Valley model(1) and the Flexible Mesh (FM) surface water model of the Bay Area(2). With this coupled groundwater-surface water model, we assessed effects of climate, surface water abstractions and groundwater pumping on surface water and groundwater levels, groundwater-surface water interaction and infiltration/seepage fluxes. Results show that the effect of climate (high flow and low flow) on surface water and groundwater is significant and most prominent in upstream areas. The surface water abstractions cause significant local surface water levels decrease (over 2 m), which may cause inflow of bay water during low flow periods, resulting in salinization of surface water in more upstream areas. Groundwater level drawdown due to surface water withdrawal is moderate and limited to the area of the withdrawals. The groundwater pumping causes large groundwater level drawdowns (up to 0.8 m) and significant changes in seepage/infiltration fluxes in the model. However, the effect on groundwater-surface water exchange is relatively small. The presented model instrument gives a sound first impression of the effects of climate and water abstraction on both surface water and groundwater. The combination of Modflow and Flexible Mesh has potential for modelling of groundwater-surface water exchange in deltaic areas, also in other parts of the world. However, various improvements need to be made in order to make the simulation results useful in practice. In addition, a water quality aspect could be added to assess salinization processes as well as groundwater-surface water aspects of water and soil pollution. (1) http://ca.water.usgs.gov/projects/central-valley/central-valley-hydrologic-model.html (2) www.d3d-baydelta.org

Lane Blockage Effects on Freeway Traffic Flow

DOT National Transportation Integrated Search

1996-09-01

Intelligent Transportation Systems (ITS) apply advanced and emerging technologies in such fields as information processing, communications, control, and electronics to surface transportation needs. ITS encompasses a number of diverse program areas in...

Effect of wildfires on surface reflectance from a savanna ecosystem

NASA Astrophysics Data System (ADS)

Poudyal, R.; Gatebe, C. K.; Ichoku, C. M.; Varnai, T.

2015-12-01

During an airborne field campaign in South Africa in 2005, NASA's Cloud Absorption Radiometer (CAR) flew aboard South Africa Weather Service, Aerocommander 690A and measured surface bidirectional reflectance-distribution function (BRDF) over savanna comprised mostly of grasses and a few scattered trees. Savannas cover half the surface of Africa, large areas of Australia, South America, and India. . The region that was studied is located in Kruger National Park in northeastern South Africa, which was heavily affected by the wildfires. The CAR measured surface reflectance along its flight path covering both burned and unburned areas. . In this study, we compared surface reflectance between burnt and un-burnt areas at various wavelengths (340nm, 380nm, 472nm, 682nm, 870nm, 1036nm, 1219nm, 1273nm, and 2205nm) at satellite sub-pixel scales. We found a relative burnt surface reflectance decrease of between 8 and 65% due to fires. These results not only serve to highlight the importance of biomass burning and effects on the energy budgets, but also the need to determine the effects of albedo changes due to fires on soil moisture budget, evapotranspiration, infiltration, and runoff, all of which govern the land-surface component of the water cycle.

MBE growth of VCSELs for high volume applications

NASA Astrophysics Data System (ADS)

Jäger, Roland; Riedl, Michael C.

2011-05-01

Mass market applications like laser computer mouse or optical data transmission based on vertical-cavity surface-emitting laser (VCSEL) chips need a high over all yield including epitaxy, processing, dicing, mounting and testing. One yield limitation for VCSEL structures is the emission wavelength variation of the substrate surface area leading to the fraction on laser chips which are below or above the specification limits. For most 850 nm VCSEL products a resonator wavelength variation of ±2 nm is common. This represents an average resonator thickness variation of much less than 1% which is quite challenging to be fulfilled on the entire processed wafer surface area. A high over all yield is demonstrated on MBE grown VCSEL structures.

Characterizing the fabric of the urban environment: A case studyof Metropolitan Chicago, Illinois and Executive Summary

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

Akbari, Hashem; Rose, Leanna Shea

2001-10-30

Urban fabric data are needed in order to estimate the impactof light-colored surfaces (roofs and pavements) and urban vegetation(trees, grass, shrubs) on the meteorology and air quality of a city, andto design effective implementation programs. In this report, we discussthe result of a semi-automatic Monte-Carlo statistical approach used todevelop data on surface-type distribution and city-fabric makeup(percentage of various surface-types) using aerial colororthophotography. The digital aerial photographs for metropolitan Chicagocovered a total of about 36 km2 (14 mi2). At 0.3m resolution, there wereapproximately 3.9 x 108 pixels of data. Four major land-use types wereexamined: commercial, industrial, residential, andtransportation/communication. On average, formore » the areas studied, atground level vegetation covers about 29 percent of the area (ranging 4 80percent); roofs cover about 25 percent (ranging 8 41 percent), and pavedsurfaces about 33 percent (ranging 12 59 percent). For the most part,trees shade streets, parking lots, grass, and side-walks. In commercialareas, paved surfaces cover 50 60 percent of the area. In residentialareas, on average, paved surfaces cover about 27percent of the area.Land-use/land-cover (LULC) data from the United States Geological Surveywas used to extrapolate these results from neighborhood scales tometropolitan Chicago. In an area of roughly 2500 km2, defining most ofmetropolitan Chicago, over 53 percent is residential. The total roof areais about 680 km2, and the total paved surfaces (roads, parking areas,sidewalks) are about 880 km2. The total vegetated area is about 680km2.« less

Restoring the hydrologic response to pre-developed conditions in an urbanized headwater catchment: Reality or utopia?

NASA Astrophysics Data System (ADS)

Wright, O.; Istanbulluoglu, E.

2012-12-01

The conversion of forested areas to impervious surfaces, lawns and pastures alters the natural hydrology of an area by increasing the flashiness of stormwater generated runoff, resulting in increased streamflow peaks and volumes. Currently, most of the stormwater from developed areas in the Puget Sound region remains uncontrolled. The lack of adequate stormwater facilities along with increasing urbanization and population growth illustrates the importance of understanding urban watershed behavior and best management practices (BMPs) that improve changes in hydrology. In this study, we developed a lumped urban ecohydrology model that represents vegetation dynamics, connects pervious and impervious surfaces and implements various BMP scenarios. The model is implemented in an urban headwater subcatchment located in the Newaukum Creek Basin. We evaluate the hydrologic impact of controlling runoff at the source and disconnecting impervious surfaces from the storm drain using rain barrels and bioretention cells. BMP scenarios consider the basin's land use/land coverage, the response of different impervious surface types, the potential for BMP placement, the size and drainage area for BMPs, and the mitigation needs to meet in-stream flow goals.

Grass seeding and soil erosion in a steep, logged area in northeastern Oregon.

Treesearch

J.D. Helvey; W.B. Fowler

1979-01-01

This case study tested the common belief that grass seeding is needed to prevent erosion after areas are clearcut in the Blue Mountains. Changes in the soil surface height at about 500 points each in a seedbed and an unseeded area were measured on four dates covering a 20-month period. Average vertical displacement was not consistently related to seeding nor to degree...

Hydrogeology for land-use planning: the Peters Creek area, Municipality of Anchorage, Alaska

USGS Publications Warehouse

Brunett, Jilann O.; Lee, Michael

1983-01-01

Wells currently provide all water supplies in the area. Most wells obtain enough water for individual household needs from unconsolidated, principally glacial and glacioalluvial deposits. In some places, however, wells must be drilled into the underlying bedrock to obtain adequate supplies. It may be possible to develop small community supplies--for individual trailer courts or subdivisions--in areas where yields of 20 gallons per minute or greater are reported for private, domestic wells. Peters Creek is a potential source of surface-water supply, but it would have to be treated to remove glacial silt during summer months. The chemical quality of both ground water and surface water in the area in generally acceptable for most uses. Foundation and excavation conditions, the potential for water pollution from onsite disposal of wastewater through septic tank systems, and the suitability of specific areas for certain types of development may be affected by the following factors: wetlands and areas of shallow ground water underlie about 30 percent of the study area; landslope exceeds 20 percent in about a third of the area; areas of fine-grained, low-permeability sediments are present locally; bedrock is within 25 feet of the land surface in about a third of the area. (USGS)

Radiofrequency-sputtered coatings for lubrication system components and other complex surfaces

NASA Technical Reports Server (NTRS)

Spalvins, T.

1972-01-01

Irregularly shaped surfaces, such as lubrication system components (ball bearings, seals, gears, etc.), can be coated on all surfaces, including irregular shapes, when radiofrequency sputtering is used. When the specimen is properly located with respect to the sputtering target, the sputtered material covers the entire surface of the object irrespective of its geometrical configuration. An adherent, dense film is formed. The film thickness varies from 20 to 50 percent on, for example, a hearing cage or race depending on its geometry. When sputtered solid film lubricants such as molybdenum disulfide are used, a film thickness only of the order of 10 to the minus 7th power m (thousands of angstroms) is required at the contacting areas. It is only essential to determine the required film thickness at the critical areas in need of lubrication. The sections outside the areas to be lubricated fall within the thickness deviation range of 20 to 50 percent, which still constitutes a negligible change respect to tolerance requirements.

Improvement of the Raman detection system for pesticide residues on/in fruits and vegetables

NASA Astrophysics Data System (ADS)

Li, Yan; Peng, Yankun; Zhai, Chen; Chao, Kuanglin; Qin, Jianwei

2017-05-01

Pesticide residue is one of the major challenges to fruits safety, while the traditional detection methods of pesticide residue on fruits and vegetables can't afford the demand of rapid detection in actual production because of timeconsuming. Thus rapid identification and detection methods for pesticide residue are urgently needed at present. While most Raman detection systems in the market are spot detection systems, which limits the range of application. In the study, our lab develops a Raman detection system to achieve area-scan thorough the self-developed spot detection Raman system with a control software and two devices. In the system, the scanning area is composed of many scanning spots, which means every spot needs to be detected and more time will be taken than area-scan Raman system. But lower detection limit will be achieved in this method. And some detection device is needed towards fruits and vegetables in different shape. Two detection devices are developed to detect spherical fruits and leaf vegetables. During the detection, the device will make spherical fruit rotate along its axis of symmetry, and leaf vegetables will be pressed in the test surface smoothly. The detection probe will be set to keep a proper distance to the surface of fruits and vegetables. It should make sure the laser shins on the surface of spherical fruit vertically. And two software are used to detect spherical fruits and leaf vegetables will be integrated to one, which make the operator easier to switch. Accordingly two detection devices for spherical fruits and leaf vegetables will also be portable devices to make it easier to change. In the study, a new way is developed to achieve area-scan result by spot-scan Raman detection system.

Frequency response of electrochemical cells

NASA Technical Reports Server (NTRS)

Thomas, Daniel L.

1989-01-01

Impedance concepts can be applied to the analysis of battery electrodes, yielding information about the structure of the electrode and the processes occurring in the electrode. Structural parameters such as the specific area (surface area per gram of electrode) can be estimated. Electrode variables such as surface overpotential, ohmic losses, and diffusion limitations may be studied. Nickel and cadmium electrodes were studied by measuring the ac impedance as a function of frequency, and the specific areas that were determined were well within the range of specific areas determined from BET measurements. Impedance spectra were measured for the nickel and cadmium electrodes, and for a 20 A-hr NiCd battery as functions of the state of charge. More work is needed to determine the feasibility of using frequency response as a nondestructive testing technique for batteries.

A Large Lunar Surface Testbed from Low Cost Material

NASA Technical Reports Server (NTRS)

Rickman, Douglas

2014-01-01

For users needing to simulate the lunar surface, several distinct avenues have been used. Numerous volcanic areas, including Hawaii, have been used. While providing very large areas and scenic interest, field parties to such an area is expensive and limits testing time. An alternative is to build test facilities locally. This has been done many ways, contrast GRC-1, GSC-1, BP-1 and the KSC Morpheus facility [1-4]. GRC-1 is a mixture of sand and clay; GSC-1 and BP-1 are waste materials created in the process of crushing basaltic rock. The Morpheus field used salvaged concrete and crushed quartz rock [5]. Here I report about a 30 m X 30 m test area at MSFC which was both low cost and relatively high fidelity [6].

Potentiometric Surface of the Ozark Aquifer in Northern Arkansas, 2007

USGS Publications Warehouse

Pugh, Aaron L.

2008-01-01

The Ozark aquifer in northern Arkansas is composed of dolomite, limestone, sandstone, and shale of Late Cambrian to Middle Devonian age, and ranges in thickness from approximately 1,100 feet to more than 4,000 feet. Hydrologically, the aquifer is complex, characterized by discrete and discontinuous flow components with large variations in permeability. The potentiometric-surface map, based on 58 well and 5 spring water-level measurements collected in 2007 in Arkansas and Missouri, has a maximum water-level altitude measurement of 1,169 feet in Carroll County and a minimum water-level altitude measurement of 118 feet in Randolph County. Regionally, the flow within the aquifer is to the south and southeast in the eastern and central part of the study area and to the west, northwest, and north in the western part of the study area. Comparing the 2007 potentiometric-surface map with a predevelopment potentiometric-surface map indicates general agreement between the two surfaces except in the northwestern part of the study area. Potentiometric-surface differences can be attributed to withdrawals related to increasing population, changes in public-supply sources, processes or water withdrawals outside the study area, or differences in data-collection or map-construction methods. The rapidly increasing population within the study area appears to have some effect on ground-water levels. Although, the effect appears to have been minimized by the development and use of surface-water distribution infrastructure, suggesting most of the incoming populations are fulfilling their water needs from surface-water sources. The conversion of some users from ground water to surface water may be allowing water levels in wells to recover (rise) or decline at a slower rate, such as in Benton, Carroll, and Washington Counties.

Some environmental problems and their satellite monitoring. [anthropogenic modifications of earth surface

NASA Technical Reports Server (NTRS)

Otterman, J.

1975-01-01

Anthropogenic modification of the earth's surface is discussed in two problem areas: (1) land use changes and overgrazing, and how it affects albedo and land surface-atmosphere interactions, and (2) water and land surface pollution, especially oil slicks. A literature survey evidences the importance of these problems. The need for monitoring is stressed, and it is suggested that with some modifications to the sensors, ERTS (Landsat) series satellites can provide approximate monitoring information. The European Landsat receiving station in Italy will facilitate data collection for the tasks described.

Hercules Single-Stage Reusable Vehicle (HSRV) Operating Base

NASA Technical Reports Server (NTRS)

Moon, Michael J.; McCleskey, Carey M.

2017-01-01

Conceptual design for the layout of lunar-planetary surface support systems remains an important area needing further master planning. This paper explores a structured approach to organize the layout of a Mars-based site equipped for routinely flying a human-scale reusable taxi system. The proposed Hercules Transportation System requires a surface support capability to sustain its routine, affordable, and dependable operation. The approach organizes a conceptual Hercules operating base through functional station sets. The station set approach will allow follow-on work to trade design approaches and consider technologies for more efficient flow of material, energy, and information at future Mars bases and settlements. The station set requirements at a Mars site point to specific capabilities needed. By drawing from specific Hercules design characteristics, the technology requirements for surface-based systems will come into greater focus. This paper begins a comprehensive process for documenting functional needs, architectural design methods, and analysis techniques necessary for follow-on concept studies.

Data needs and data bases for climate studies

NASA Technical Reports Server (NTRS)

Matthews, Elaine

1986-01-01

Two complementary global digital data bases of vegetation and land use, compiled at 1 deg resolution from published sources for use in climate studies, are discussed. The data bases were implemented, in several individually tailored formulations, in a series of climate related applications including: land-surface prescriptions in three-dimensional general circulation models, global biogeochemical cycles (CO2, methane), critical-area mapping for satellite monitoring of land-cover change, and large-scale remote sensing of surface reflectance. The climate applications are discussed with reference to data needs, and data availability from traditional and remote sensing sources.

Characterizing the fabric of the urban environment: A case study of Greater Houston, Texas

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

Rose, Leanna Shea; Akbari, Hashem; Taha, Haider

2003-01-15

In this report, the materials and various surface types that comprise a city are referred to as the ''urban fabric.'' Urban fabric data are needed in order to estimate the impact of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city, and to design effective urban environmental implementation programs. We discuss the results of a semi-automatic Monte-Carlo statistical approach used to develop data on surface-type distribution and city-fabric makeup (percentage of various surface-types) using aerial color orthophotography. The digital aerial photographs for Houston covered a total of about 52more » km2 (20 mi2). At 0.30-m resolution, there were approximately 5.8 x 108 pixels of data. Four major land-use types were examined: (1) commercial, (2) industrial, (3) educational, and (4) residential. On average, for the regions studied, vegetation covers about 39 percent of the area, roofs cover about 21 percent, and paved surfaces cover about 29 percent. For the most part, trees shade streets, parking lots, grass, and sidewalks. At ground level, i.e., view from below the vegetation canopies, paved surfaces cover about 32 percent of the study area. GLOBEIS model data from University of Texas and land-use/land-cover (LULC) information from the United States Geological Survey (USGS) were used to extrapolate these results from neighborhood scales to Greater Houston. It was found that in an area of roughly 3,430 km2, defining most of Greater Houston, over 56 percent is residential. The total roof area is about 740 km2, and the total paved surface area (roads, parking areas, sidewalks) covers about 1000 km2. Vegetation covers about 1,320 km2.« less

Synthesis and Characterization of Poly(maleic Anhydride)s Cross-linked Polyimide Aerogels

NASA Technical Reports Server (NTRS)

Guo, Haiquan; Meador, Mary Ann B.

2015-01-01

With the development of technology for aerospace applications, new thermal insulation materials are required to be flexible and capable of surviving high heat flux. For instance, flexible insulation is needed for inflatable aerodynamic decelerators which are used to slow spacecraft for entry, descent and landing (EDL) operations. Polyimide aerogels have low density, high porosity, high surface area, and better mechanical properties than silica aerogels and can be made into flexible thin films, thus they are potential candidates for aerospace needs. The previously reported cross-linkers such as octa(aminophenyl)silsesquioxane (OAPS) and 1,3,5-triaminophenoxybenzene (TAB) are either expensive or not commercially available. Here, we report the synthesis of a series of polyimide aerogels cross-linked using various commercially available poly(maleic anhydride)s, as seen in Figure 1. The amine end capped polyimide oligomers were made with 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA) and diamine combinations of dimethylbenzidine (DMBZ) and 4, 4-oxydianiline (ODA). The resulting aerogels have low density (0.12 gcm3 to 0.16 gcm3), high porosity (90) and high surface area (380-554 m2g). The effect of the different poly(maleic anhydride) cross-linkers and polyimide backbone structures on density, shrinkage, porosity, surface area, mechanical properties, moisture resistance and thermal properties will be discussed.

Evaluation of Satellite Remote Sensing Albedo Retrievals over the Ablation Area of the Southwestern Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Moustafa, Samiah E.; Rennermalm, Asa K.; Roman, Miguel O.; Wang, Zhuosen; Schaaf, Crystal B.; Smith, Laurence C.; Koenig, Lora S.; Erb, Angela

2017-01-01

MODerate resolution Imaging Spectroradiometer (MODIS) albedo products have been validated over spatially uniform, snow-covered areas of the Greenland ice sheet (GrIS) using the so-called single 'point-to-pixel' method. This study expands on this methodology by applying a 'multiple-point-to-pixel' method and examination of spatial autocorrelation (here using semivariogram analysis) by using in situ observations, high-resolution World- View-2 (WV-2) surface reflectances, and MODIS Collection V006 daily blue-sky albedo over a spatially heterogeneous surfaces in the lower ablation zone in southwest Greenland. Our results using 232 ground-based samples within two MODIS pixels, one being more spatial heterogeneous than the other, show little difference in accuracy among narrow and broad band albedos (except for Band 2). Within the more homogenous pixel area, in situ and MODIS albedos were very close (error varied from -4% to +7%) and within the range of ASD standard errors. The semivariogram analysis revealed that the minimum observational footprint needed for a spatially representative sample is 30 m. In contrast, over the more spatially heterogeneous surface pixel, a minimum footprint size was not quantifiable due to spatial autocorrelation, and far exceeds the effective resolution of the MODIS retrievals. Over the high spatial heterogeneity surface pixel, MODIS is lower than ground measurements by 4-7%, partly due to a known in situ undersampling of darker surfaces that often are impassable by foot (e.g., meltwater features and shadowing effects over crevasses). Despite the sampling issue, our analysis errors are very close to the stated general accuracy of the MODIS product of 5%. Thus, our study suggests that the MODIS albedo product performs well in a very heterogeneous, low-albedo, area of the ice sheet ablation zone. Furthermore, we demonstrate that single 'point-to-pixel' methods alone are insufficient in characterizing and validating the variation of surface albedo displayed in the lower ablation area. This is true because the distribution of in situ data deviations from MODIS albedo show a substantial range, with the average values for the 10th and 90th percentiles being -0.30 and 0.43 across all bands. Thus, if only single point is taken for ground validation, and is randomly selected from either distribution tails, the error would appear to be considerable. Given the need for multiple in-situ points, concurrent albedo measurements derived from existing AWSs, (low-flying vehicles (airborne or unmanned) and high-resolution imagery (WV-2)) are needed to resolve high sub-pixel variability in the ablation zone, and thus, further improve our characterization of Greenland's surface albedo.

Landscape characteristics affecting streams in urbanizing regions of the Delaware River Basin (New Jersey, New York, and Pennsylvania, U.S.)

Treesearch

Karen Riva-Murray; Rachel Riemann; Peter Murdoch; Jeffrey M. Fischer; Robin. Brightbill

2010-01-01

Widespread and increasing urbanization has resulted in the need to assess, monitor, and understand its effects on stream water quality. Identifying relations between stream ecological condition and urban intensity indicators such as impervious surface provides important, but insufficient information to effectively address planning and management needs in such areas. In...

Surface-directed capillary system; theory, experiments and applications.

PubMed

Bouaidat, Salim; Hansen, Ole; Bruus, Henrik; Berendsen, Christian; Bau-Madsen, Niels Kristian; Thomsen, Peter; Wolff, Anders; Jonsmann, Jacques

2005-08-01

We present a capillary flow system for liquid transport in microsystems. Our simple microfluidic system consists of two planar parallel surfaces, separated by spacers. One of the surfaces is entirely hydrophobic, the other mainly hydrophobic, but with hydrophilic pathways defined on it by photolithographic means. By controlling the wetting properties of the surfaces in this manner, the liquid can be confined to certain areas defined by the hydrophilic pathways. This technique eliminates the need for alignment of the two surfaces. Patterned plasma-polymerized hexafluoropropene constitutes the hydrophobic areas, whereas the untreated glass surface constitutes the hydrophilic pathways. We developed a theoretical model of the capillary flow and obtained analytical solutions which are in good agreement with the experimental results. The capillarity-driven microflow system was also used to pattern and immobilize biological material on planar substrates: well-defined 200 microm wide strips of human cells (HeLa) and fluorescence labelled proteins (fluorescein isothiocyanate-labelled bovine serum albumin, i.e., FITC-BSA) were fabricated using the capillary flow system presented here.

Quantitative analysis of trace levels of surface contamination by X-ray photoelectron spectroscopy Part I: statistical uncertainty near the detection limit.

PubMed

Hill, Shannon B; Faradzhev, Nadir S; Powell, Cedric J

2017-12-01

We discuss the problem of quantifying common sources of statistical uncertainties for analyses of trace levels of surface contamination using X-ray photoelectron spectroscopy. We examine the propagation of error for peak-area measurements using common forms of linear and polynomial background subtraction including the correlation of points used to determine both background and peak areas. This correlation has been neglected in previous analyses, but we show that it contributes significantly to the peak-area uncertainty near the detection limit. We introduce the concept of relative background subtraction variance (RBSV) which quantifies the uncertainty introduced by the method of background determination relative to the uncertainty of the background area itself. The uncertainties of the peak area and atomic concentration and of the detection limit are expressed using the RBSV, which separates the contributions from the acquisition parameters, the background-determination method, and the properties of the measured spectrum. These results are then combined to find acquisition strategies that minimize the total measurement time needed to achieve a desired detection limit or atomic-percentage uncertainty for a particular trace element. Minimization of data-acquisition time is important for samples that are sensitive to x-ray dose and also for laboratories that need to optimize throughput.

Needs, opportunities and strategies for a long-term oceanic sciences satellite program

NASA Technical Reports Server (NTRS)

Ruttenberg, S. (Editor)

1981-01-01

Several areas of the National Oceanic Satellite System are addressed including Satellite-borne communication systems, subsurface remote sensing, data coordination, color scanners, formatting important historical data sets, and sea surface temperature observations.

The use of radar imagery for surface water investigations

NASA Technical Reports Server (NTRS)

Bryan, M. L.

1981-01-01

The paper is concerned with the interpretation of hydrologic features using L-band (HH) imagery collected by aircraft and Seasat systems. Areas of research needed to more precisely define the accuracy and repeatability of measurements related to the conditions of surfaces and boundaries of fresh water bodies are identified. These include: the definition of shoreline, the nature of variations in surface roughness across a water body and along streams and lake shores, and the separation of ambiguous conditions which appear similar to lakes.

Aerocapture Inflatable Decelerator for Planetary Entry

NASA Technical Reports Server (NTRS)

Reza, Sajjad; Hund, Richard; Kustas, Frank; Willcockson, William; Songer, Jarvis; Brown, Glen

2007-01-01

Forward Attached Inflatable Decelerators, more commonly known as inflatable aeroshells, provide an effective, cost efficient means of decelerating spacecrafts by using atmospheric drag for aerocapture or planetary entry instead of conventional liquid propulsion deceleration systems. Entry into planetary atmospheres results in significant heating and aerodynamic pressures which stress aeroshell systems to their useful limits. Incorporation of lightweight inflatable decelerator surfaces with increased surface-area footprints provides the opportunity to reduce heat flux and induced temperatures, while increasing the payload mass fraction. Furthermore, inflatable aeroshell decelerators provide the needed deceleration at considerably higher altitudes and Mach numbers when compared with conventional rigid aeroshell entry systems. Inflatable aeroshells also provide for stowage in a compact space, with subsequent deployment of a large-area, lightweight heatshield to survive entry heating. Use of a deployable heatshield decelerator enables an increase in the spacecraft payload mass fraction and may eliminate the need for a spacecraft backshell.

Opto-Technical Monitoring - a Standardized Methodology to Assess the Treatment of Historical Stone Surfaces

NASA Astrophysics Data System (ADS)

Rahrig, M.; Drewello, R.; Lazzeri, A.

2018-05-01

Monitoring is an essential requirement for the planning, assessment and evaluation of conservation measures. It should be based on a standardized and reproducible observation of the historical surface. For many areas and materials suitable methods for long-term monitoring already exist. But hardly any non-destructive testing methods have been used to test new materials for conservation of damaged stone surfaces. The Nano-Cathedral project, funded by the European Union's Horizon 2020 research and innovation program, is developing new materials and technologies for preserving damaged stone surfaces of built heritage. The prototypes developed are adjusted to the needs and problems of a total of six major cultural monuments in Europe. In addition to the testing of the materials under controlled laboratory conditions, the products have been applied to trial areas on the original stone surfaces. For a location-independent standardized assessment of surface changes of the entire trial areas a monitoring method based on opto-technical, non-contact and non-destructive testing methods has been developed. This method involves a three-dimensional measurement of the surface topography using Structured-Light-Scanning and the analysis of the surfaces in different light ranges using high resolution VIS photography, as well as UV-A-fluorescence photography and reflected near-field IR photography. The paper will show the workflow of this methodology, including a detailed description of the equipment used data processing and the advantages for monitoring highly valuable stone surfaces. Alongside the theoretical discussion, the results of two measuring campaigns on trial areas of the Nano-Cathedral project will be shown.

Osseointegrated dental implants produced via microwave processing

NASA Astrophysics Data System (ADS)

Kutty, Muralithran G.

This research is a comprehensive effort to develop osseointegrated dental implants via microwave processing. A net-shape microwave sintering procedure was employed to fabricate dental implants. Commercial pure titanium powders (-100, -200 and -325 mesh sizes) were used in this work. This process eliminates the need for machining of implants and prevents contamination. The idea was to take advantage of the peculiar way microwave couple with metallic powders, i.e. generating heat in the interior of the sample and dissipating it away through the surface. The desired features for an implant, a dense core with surface pores, is not possible via conventional sintering. Coating with hydroxyapatite via electrodeposition and chemical combustion vapor deposition was also attempted to further enhance the bioactivity of this layer. Surface roughness and area were measured using a non-contact surface profilometer to further describe the unique surface. In-vitro studies, conducted using osteoblast cells extracted from neonatal rat calvarial, showed improved cell growth on all the uncoated porous samples. However, the highest cell growth was observed on the -200 mesh size samples. The higher surface area of the -200 mesh samples is attributed to this observation. This work was able to identify the processing parameters for titanium in microwave and establishes the importance of surface area as a key parameter for cell growth on porous surfaces as compared to surface roughness.

High-energy x-ray diffraction from surfaces and nanoparticles

NASA Astrophysics Data System (ADS)

Hejral, U.; Müller, P.; Shipilin, M.; Gustafson, J.; Franz, D.; Shayduk, R.; Rütt, U.; Zhang, C.; Merte, L. R.; Lundgren, E.; Vonk, V.; Stierle, A.

2017-11-01

High-energy surface-sensitive x-ray diffraction (HESXRD) is a powerful high-energy photon technique (E > 70 keV) that has in recent years proven to allow a fast data acquisition for the 3D structure determination of surfaces and nanoparticles under in situ and operando conditions. The use of a large-area detector facilitates the direct collection of nearly distortion-free diffraction patterns over a wide q range, including crystal truncation rods perpendicular to the surface and large-area reciprocal space maps from epitaxial nanoparticles, which is not possible in the conventional low-photon energy approach (E =10 -20 keV ). Here, we present a comprehensive mathematical approach, explaining the working principle of HESXRD for both single-crystal surfaces and epitaxial nanostructures on single-crystal supports. The angular calculations used in conventional crystal truncation rod measurements at low-photon energies are adopted for the high-photon-energy regime, illustrating why and to which extent large reciprocal-space areas can be probed in stationary geometry with fixed sample rotation. We discuss how imperfections such as mosaicity and finite domain size aid in sampling a substantial part of reciprocal space without the need of rotating the sample. An exact account is given of the area probed in reciprocal space using such a stationary mode, which is essential for in situ or operando time-resolved experiments on surfaces and nanostructures.

Preliminary post-tsunami water quality survey in Phang-Nga province, southern Thailand.

PubMed

Tharnpoophasiam, Prapin; Suthisarnsuntorn, Usanee; Worakhunpiset, Suwalee; Charoenjai, Prasasana; Tunyong, Witawat; Phrom-In, Suvannee; Chattanadee, Siriporn

2006-01-01

This preliminary water quality survey was performed eight weeks after the tsunami hit Phang-Nga Province on 26 December 2004. Water samples collected from the affected area, 10 km parallel to the seaside, were compared with water samples from the control area approximately 4 km from the seaside, which the tsunami waves could not reach. These samples included 18 surface-water samples, 37 well-water samples, and 8 drinking-water samples, which were examined for microbiology and physical-chemical properties. The microbiological examinations focused on enteric bacteria, which were isolated by culture method, while physical-chemical properties comprised on-site testing for pH, salinity, dissolved oxygen (DO), conductivity and total dissolved solids (TDS) by portable electrochemical meter (Sens Ion 156). The results of the microbiological examinations showed that water samples in the affected areas were more contaminated with enteric bacteria than the control area: 45.4% of surface-water samples in the affected area, and 40.0% in the control; 19.0% of well-water samples in the affected area, and 7.7% in the control. All eight drinking-water samples were clear of enteric bacteria. Tests for physical-chemical properties showed that the salinity, pH, conductivity, and TDS of surface-water samples from the affected area were significantly higher than the control. The salinity, conductivity, and TDS of the well-water samples from the affected areas were also significantly greater than those from the control area. The surface and well water in the tsunami-affected area have been changed greatly and need improvement.

Exploring proximity effects and large depth of field in helium ion beam lithography: large-area dense patterns and tilted surface exposure.

PubMed

Flatabø, Ranveig; Agarwal, Akshay; Hobbs, Richard; Greve, Martin M; Holst, Bodil; Berggren, Karl K

2018-07-06

Helium ion beam lithography (HIL) is an emerging nanofabrication technique. It benefits from a reduced interaction volume compared to that of an electron beam of similar energy, and hence reduced long-range scattering (proximity effect), higher resist sensitivity and potentially higher resolution. Furthermore, the small angular spread of the helium ion beam gives rise to a large depth of field. This should enable patterning on tilted and curved surfaces without the need of any additional adjustments, such as laser-auto focus. So far, most work on HIL has been focused on exploiting the reduced proximity effect to reach single-digit nanometer resolution, and has thus been concentrated on single-pixel exposures over small areas. Here we explore two new areas of application. Firstly, we investigate the proximity effect in large-area exposures and demonstrate HIL's capabilities in fabricating precise high-density gratings on large planar surfaces (100 μm × 100 μm, with pitch down to 35 nm) using an area dose for exposure. Secondly, we exploit the large depth of field by making the first HIL patterns on tilted surfaces (sample stage tilted 45°). We demonstrate a depth of field greater than 100 μm for a resolution of about 20 nm.

Research note: Mapping spatial patterns in sewer age, material, and proximity to surface waterways to infer sewer leakage hotspots

USGS Publications Warehouse

Hopkins, Kristina G.; Bain, Daniel J.

2018-01-01

Identifying areas where deteriorating sewer infrastructure is in close proximity to surface waterways is needed to map likely connections between sewers and streams. We present a method to estimate sewer installation year and deterioration status using historical maps of the sewer network, parcel-scale property assessment data, and pipe material. Areas where streams were likely buried into the sewer system were mapped by intersecting the historical stream network derived from a 10-m resolution digital elevation model with sewer pipe locations. Potential sewer leakage hotspots were mapped by identifying where aging sewer pipes are in close proximity (50-m) to surface waterways. Results from Pittsburgh, Pennsylvania (USA), indicated 41% of the historical stream length was lost or buried and the potential interface between sewers and streams is great. The co-location of aging sewer infrastructure (>75 years old) near stream channels suggests that 42% of existing streams are located in areas with a high potential for sewer leakage if sewer infrastructure fails. Mapping the sewer-stream interface provides an approach to better understand areas were failing sewers may contribute a disproportional amount of nutrients and other pathogens to surface waterways.

Resolution dependence of petrophysical parameters derived from X-ray tomography of chalk

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

Müter, D.; Sørensen, H. O.; Jha, D.

2014-07-28

X-ray computed tomography data from chalk drill cuttings were taken over a series of voxel dimensions, ranging from 320 to 25 nm. From these data sets, standard petrophysical parameters (porosity, surface area, and permeability) were derived and we examined the effect of the voxel dimension (i.e., image resolution) on these properties. We found that for the higher voxel dimensions, they are severely over or underestimated, whereas for 50 and 25 nm voxel dimension, the resulting values (5%–30% porosity, 0.2–2 m{sup 2}/g specific surface area, and 0.06–0.34 mD permeability) are within the expected range for this type of rock. We compared our resultsmore » to macroscopic measurements and in the case of surface area, also to measurements using the Brunauer-Emmett-Teller (BET) method and found that independent of the degree of compaction, the results from tomography amount to about 30% of the BET method. Finally, we concluded that at 25 nm voxel dimension, the essential features of the nanoscopic pore network in chalk are captured but better resolution is still needed to derive surface area.« less

Operation BUSTER. Project 2.2. Thermal and Blast Effects on Idealized Forest Fuels

DTIC Science & Technology

1952-04-29

outside the test area . Naturally occurring fuels at the test site mm brush, grass clumps, and Joshua bark — ware studied before the tests and...oharrad« Conclusions based on results and observations from Operation BDSBRt 1. Under fire weather oonditionsi/ in a forest area , atomic ex...following atomic explosions over forest areas * 5* Bomb-induced conreotion does not produce surface winds follow« lag blastHTind effects and need not be

77 FR 41370 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

... Response: 5 minutes. Burden Hours: 10,235. Needs and Uses: This request is for extension of a current... one or two color codes, designating the type of gear and area where the gear is set. The surface buoys...

High Resolution Surface Geometry and Albedo by Combining Laser Altimetry and Visible Images

NASA Technical Reports Server (NTRS)

Morris, Robin D.; vonToussaint, Udo; Cheeseman, Peter C.; Clancy, Daniel (Technical Monitor)

2001-01-01

The need for accurate geometric and radiometric information over large areas has become increasingly important. Laser altimetry is one of the key technologies for obtaining this geometric information. However, there are important application areas where the observing platform has its orbit constrained by the other instruments it is carrying, and so the spatial resolution that can be recorded by the laser altimeter is limited. In this paper we show how information recorded by one of the other instruments commonly carried, a high-resolution imaging camera, can be combined with the laser altimeter measurements to give a high resolution estimate both of the surface geometry and its reflectance properties. This estimate has an accuracy unavailable from other interpolation methods. We present the results from combining synthetic laser altimeter measurements on a coarse grid with images generated from a surface model to re-create the surface model.

Climate Products and Services to Meet the Challenges of Extreme Events

NASA Astrophysics Data System (ADS)

McCalla, M. R.

2008-12-01

The 2002 Office of the Federal Coordinator for Meteorological Services and Supporting Research (OFCM1)-sponsored report, Weather Information for Surface Transportation: National Needs Assessment Report, addressed meteorological needs for six core modes of surface transportation: roadway, railway, transit, marine transportation/operations, pipeline, and airport ground operations. The report's goal was to articulate the weather information needs and attendant surface transportation weather products and services for those entities that use, operate, and manage America's surface transportation infrastructure. The report documented weather thresholds and associated impacts which are critical for decision-making in surface transportation. More recently, the 2008 Climate Change Science Program's (CCSP) Synthesis and Assessment Product (SAP) 4.7 entitled, Impacts of Climate Change and Variability on Transportation Systems and Infrastructure: Gulf Coast Study, Phase I, included many of the impacts from the OFCM- sponsored report in Table 1.1 of this SAP.2 The Intergovernmental Panel on Climate Change (IPCC) reported that since 1950, there has been an increase in the number of heat waves, heavy precipitation events, and areas of drought. Moreover, the IPCC indicated that greater wind speeds could accompany more severe tropical cyclones.3 Taken together, the OFCM, CCSP, and IPCC reports indicate not only the significance of extreme events, but also the potential increasing significance of many of the weather thresholds and associated impacts which are critical for decision-making in surface transportation. Accordingly, there is a real and urgent need to understand what climate products and services are available now to address the weather thresholds within the surface transportation arena. It is equally urgent to understand what new climate products and services are needed to address these weather thresholds, and articulate what can be done to fill the gap between the existing federal climate products and services and the needed federal climate products and services which will address these weather thresholds. Just as important, as we work to meet the needs, a robust education and outreach program is essential to take full advantage of new products, services and capabilities. To ascertain what climate products and services currently exist to address weather thresholds relative to surface transportation, what climate products and services are needed to address these weather thresholds, and how to bridge the gap between what is available and what is needed, the OFCM surveyed the federal meteorological community. Consistent with the extreme events highlighted in the IPCC report, the OFCM survey categorized the weather thresholds associated with surface transportation into the following extreme event areas: (a) excessive heat, (b) winter precipitation, (c) summer precipitation, (d) high winds, and (e) flooding and coastal inundation. The survey results, the gap analysis, as well as OFCM's planned, follow-on activities with additional categories (i.e., in addition to surface transportation) and weather thresholds will be shared with meeting participants. 1 The OFCM is an interdepartmental office established in response to Public Law 87-843 with the mission to ensure the effective use of federal meteorological resources by leading the systematic coordination of operational weather and climate requirements, products, services, and supporting research among the federal agencies. 2 http://www.climatescience.gov/Library/sap/sap4-7/final-report/sap4-7-final-ch1.pdf 3 http://www.gcrio.org/ipcc/ar4/wg1/faq/ar4wg1faq-3-3.pdf

Automated AFM for small-scale and large-scale surface profiling in CMP applications

NASA Astrophysics Data System (ADS)

Zandiatashbar, Ardavan; Kim, Byong; Yoo, Young-kook; Lee, Keibock; Jo, Ahjin; Lee, Ju Suk; Cho, Sang-Joon; Park, Sang-il

2018-03-01

As the feature size is shrinking in the foundries, the need for inline high resolution surface profiling with versatile capabilities is increasing. One of the important areas of this need is chemical mechanical planarization (CMP) process. We introduce a new generation of atomic force profiler (AFP) using decoupled scanners design. The system is capable of providing small-scale profiling using XY scanner and large-scale profiling using sliding stage. Decoupled scanners design enables enhanced vision which helps minimizing the positioning error for locations of interest in case of highly polished dies. Non-Contact mode imaging is another feature of interest in this system which is used for surface roughness measurement, automatic defect review, and deep trench measurement. Examples of the measurements performed using the atomic force profiler are demonstrated.

The development of composite materials for spacecraft precision reflector panels

NASA Technical Reports Server (NTRS)

Tompkins, Stephen S.; Bowles, David E.; Funk, Joan G.; Towell, Timothy W.; Lavoie, J. A.

1990-01-01

One of the critical technology needs for large precision reflectors required for future astrophysics and optical communications is in the area of structural materials. Therefore, a major area of the Precision Segmented Reflector Program at NASA is to develop lightweight composite reflector panels with durable, space environmentally stable materials which maintain both surface figure and required surface accuracy necessary for space telescope applications. Results from the materials research and development program at NASA Langley Research Center are discussed. Advanced materials that meet the reflector panel requirements are identified. Thermal, mechanical and durability properties of candidate materials after exposure to simulated space environments are compared to the baseline material.

Relating Radiative Fluxes on Arctic Sea Ice Area Using Arctic Observation and Reanalysis Integrated System (ArORIS)

NASA Astrophysics Data System (ADS)

Sledd, A.; L'Ecuyer, T. S.

2017-12-01

With Arctic sea ice declining rapidly and Arctic temperatures rising faster than the rest of the globe, a better understanding of the Arctic climate, and ice cover-radiation feedbacks in particular, is needed. Here we present the Arctic Observation and Reanalysis Integrated System (ArORIS), a dataset of integrated products to facilitate studying the Arctic using satellite, reanalysis, and in-situ datasets. The data include cloud properties, radiative fluxes, aerosols, meteorology, precipitation, and surface properties, to name just a few. Each dataset has uniform grid-spacing, time-averaging and naming conventions for ease of use between products. One intended use of ArORIS is to assess Arctic radiation and moisture budgets. Following that goal, we use observations from ArORIS - CERES-EBAF radiative fluxes and NSIDC sea ice fraction and area to quantify relationships between the Arctic energy balance and surface properties. We find a discernable difference between energy budgets for years with high and low September sea ice areas. Surface fluxes are especially responsive to the September sea ice minimum in months both leading up to September and the months following. In particular, longwave fluxes at the surface show increased sensitivity in the months preceding September. Using a single-layer model of solar radiation we also investigate the individual responses of surface and planetary albedos to changes in sea ice area. By partitioning the planetary albedo into surface and atmospheric contributions, we find that the atmospheric contribution to planetary albedo is less sensitive to changes in sea ice area than the surface contribution. Further comparisons between observations and reanalyses can be made using the available datasets in ArORIS.

Sustainable nano-catalysis

EPA Science Inventory

A novel nano-catalyst system which bridges the homogenous and heterogeneous system is described that is cheaper, easily accessible (sustainable) and requires no need of catalyst filtration during the work-up. Because of its nano-size, i.e. high surface area, the contact between r...

OAST Theme Workshop. Volume 3: Working group summary. 8: Structures, dynamics (M-2). A. Statement. B. Technology needs (form 1). C. Priority assessments (form 2)

NASA Technical Reports Server (NTRS)

1976-01-01

A technology program on large space structures was defined to respond to common need perceived for five of the six themes. Greatly expanded power, facilities, and communications/sensing requirements appear to demand a new structures technology for construction in space. Requirements to construct huge structural arrays with precision surfaces in space will need creative research efforts to identify practical structural elements and construction techniques. Requirements for advanced transportation structures were defined to respond to the space transportation theme. Because of the criticality of thermal structures to achieve lower cost transportation systems, renewed emphasis on technology in this area is recommended. A second technology needing renewed emphasis is the area of recovery and landing technology structures to permit full reuse of launch vehicle propulsion elements.

Coupling device with improved thermal interface

NASA Astrophysics Data System (ADS)

Milam, Malcolm Bruce

1992-04-01

The primary object of the present invention is to provide a simple, reliable, and lightweight coupling that will also have an efficient thermal interface. A further object of the invention is to provide a coupling that is capable of blind mating with little or no insertion forces. Another object of the invention is to provide a coupling that acts as a thermal regulator to maintain a constant temperature on one side of the coupling. Another object of the invention is to increase the available surface area of a coupling thus providing a larger area for the conduction of heat across the thermal interface. Another object of the invention is to provide a fluidic coupling that has no fluid passing across the interface, thus reducing the likelihood of leaks and contamination. The foregoing objects are achieved by utilizing, as in the prior art, a hot area (at an elevated temperature as compared to a cold area) with a need to remove excess heat from the hot area to a cold area. In this device, the thermal interface will occur not on a planar horizontal surface, but along a non-planar vertical surface, which will reduce the reaction forces and increase the thermal conductivity of the device. One non-planar surface is a surface on a cold pin extending from the cold area and the other non-planar surface is a surface on a hot pin extending from the hot area. The cold pin is fixed and does not move while the hot pin is a flexible member and its movement towards the cold pin will bring the two non-planar surfaces together forming the thermal interface. The actuating member for the device is a shape-memory actuation wire which is attached through an aperture to the hot pin and through another aperture to an actuation wire retainer. By properly programming the actuation wire, heat from the hot area will cause the actuation wire to bend the hot wire. Heat from the hot area will cause the actuation wire to bend the hot pin towards the cold pin forming the coupling and the desired thermal interface. The shape-memory actuation wire is made of a shape-memory-effect alloy such as Nitinol.

Measuring Surface Deformation in Glacier Retreated Areas Based on Ps-Insar - Geladandong Glacier as a Case Study

NASA Astrophysics Data System (ADS)

Mohamadi, B.; Balz, T.

2018-04-01

Glaciers are retreating in many parts of the world as a result of global warming. Many researchers consider Qinghai-Tibetan Plateau as a reference for climate change by measuring glaciers retreat on the plateau. This retreat resulted in some topographic changes in retreated areas, and in some cases can lead to geohazards as landslides, and rock avalanches, which is known in glacier retreated areas as paraglacial slope failure (PSF). In this study, Geladandong biggest and main glacier mass was selected to estimate surface deformation on its glacier retreated areas and define potential future PSF based on PS-InSAR technique. 56 ascending and 49 descending images were used to fulfill this aim. Geladandong glacier retreated areas were defined based on the maximum extent of the glacier in the little ice age. Results revealed a general uplift in the glacier retreated areas with velocity less than 5mm/year. Obvious surface motion was revealed in seven parts surround glacier retreated areas with high relative velocity reached ±60mm/year in some parts. Four parts were considered as PSF potential motion, and two of them showed potential damage for the main road in the study area in case of rock avalanche into recent glacier lakes that could result in glacier lake outburst flooding heading directly to the road. Finally, further analysis and field investigations are needed to define the main reasons for different types of deformation and estimate future risks of these types of surface motion in the Qinghai-Tibetan Plateau.

Modeling Košice Green Roofs Maps

NASA Astrophysics Data System (ADS)

Poorova, Zuzana; Vranayova, Zuzana

2017-06-01

The need to house population in urban areas is expected to rise to 66% in 2050, according to United Nations. The replacement of natural permeable green areas with concrete constructions and hard surfaces will be noticed. The densification of existing built-up areas is responsible for the decreasing vegetation, which results in the lack of evapotranspiration cooling the air. Such decreasing vegetation causes urban heat islands. Since roofs and pavements have a very low albedo, they absorb a lot of sunlight. Several studies have shown that natural and permeable surfaces, as in the case of green roofs, can play crucial role in mitigating this negative climate phenomenon and providing higher efficiency for the building, leading to savings. Such as water saving, what is the main idea of this research.

The Relationship between Self-Assembly and Conformal Mappings

NASA Astrophysics Data System (ADS)

Duque, Carlos; Santangelo, Christian

The isotropic growth of a thin sheet has been used as a way to generate programmed shapes through controlled buckling. We discuss how conformal mappings, which are transformations that locally preserve angles, provide a way to quantify the area growth needed to produce a particular shape. A discrete version of the conformal map can be constructed from circle packings, which are maps between packings of circles whose contact network is preserved. This provides a link to the self-assembly of particles on curved surfaces. We performed simulations of attractive particles on a curved surface using molecular dynamics. The resulting particle configurations were used to generate the corresponding discrete conformal map, allowing us to quantify the degree of area distortion required to produce a particular shape by finding particle configurations that minimize the area distortion.

Quantifying root water extraction after drought recovery using sub-mm in situ empirical data

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

Dhiman, Indu; Bilheux, Hassina Z.; DeCarlo, Keito F.

Root-specific responses to stress are not well-known, and have been largely based on indirect measurements of bulk soil water extraction, which limits mechanistic modeling of root function. Here, we used neutron radiography to examine in situ root-soil water dynamics of a previously droughted black cottonwood ( Populus trichocarpa) seedling, contrasting water uptake by younger, thinner or older, thicker parts of the fine root system. The smaller diameter roots had greater water uptake capacity per unit surface area than the larger diameter roots, but they had less total surface area leading to less total water extraction; rates ranged from 0.0027 –more » 0.0116 g cm -2 hr -1. The finest most-active roots were not visible in the radiographs, indicating the need to include destructive sampling. Analysis based on bulk soil hydraulic properties indicated substantial redistribution of water via saturated/unsaturated flow, capillary wicking, and root hydraulic redistribution across the layers - suggesting water uptake dynamics following an infiltration event may be more complex than approximated by common soil hydraulic or root surface area modeling approaches. Lastly, our results highlight the need for continued exploration of root-trait specific water uptake rates in situ, and impacts of roots on soil hydraulic properties – both critical components for mechanistic modeling of root function.« less

Quantifying root water extraction after drought recovery using sub-mm in situ empirical data

DOE PAGES

Dhiman, Indu; Bilheux, Hassina Z.; DeCarlo, Keito F.; ...

2017-09-09

Root-specific responses to stress are not well-known, and have been largely based on indirect measurements of bulk soil water extraction, which limits mechanistic modeling of root function. Here, we used neutron radiography to examine in situ root-soil water dynamics of a previously droughted black cottonwood ( Populus trichocarpa) seedling, contrasting water uptake by younger, thinner or older, thicker parts of the fine root system. The smaller diameter roots had greater water uptake capacity per unit surface area than the larger diameter roots, but they had less total surface area leading to less total water extraction; rates ranged from 0.0027 –more » 0.0116 g cm -2 hr -1. The finest most-active roots were not visible in the radiographs, indicating the need to include destructive sampling. Analysis based on bulk soil hydraulic properties indicated substantial redistribution of water via saturated/unsaturated flow, capillary wicking, and root hydraulic redistribution across the layers - suggesting water uptake dynamics following an infiltration event may be more complex than approximated by common soil hydraulic or root surface area modeling approaches. Lastly, our results highlight the need for continued exploration of root-trait specific water uptake rates in situ, and impacts of roots on soil hydraulic properties – both critical components for mechanistic modeling of root function.« less

HIGH STRENGTH GLASS FIBERS DEVELOPMENT PROGRAM

DTIC Science & Technology

Contents: Status of information relative to commercial fiberglass Intrinsic strength of the glass fiber Degree of surface damage existing in...the fibers after processing into the filament wound structure Failure mechanisms in a filament wound structure Need for understanding in two distinct problem areas

Hydrologic effects of ground- and surface-water withdrawals in the Milford area, Elkhart and Kosciusko counties, Indiana

USGS Publications Warehouse

Lindgren, H.A.; Peters, J.G.; Cohen, D.A.; Crompton, E.J.

1985-01-01

Results of plans 1, 2, 3, and 4 indicate that the outwash system provides adequate water for current (1982) needs and substantial growth for irrigation. However, maximum irrigational development might cause temporary, local competition for water in several parts of the area. Plan 5 indicates .that water use could increase substantially before effects of pumping would prevail year-round.

Representation of urban surfaces of tropical and subtropical cities in numerical models of the atmosphere

NASA Astrophysics Data System (ADS)

Karam, H. A.; Pereira Filho, A. J.

This work proposes a numerical representation of the urban surface for tropical and subtropical cities in numerical models of atmosphere. A typical tropical metropolis is São Paulo City, SP, Brazil, that presents a neighborhood area characterized by an uncompleted urbanization and where the public services are limited in attend the needs of the population. The suburban area of São Paulo city presents an occupation that is distinguished of the typical occupation of the European cities because: (1) it occurs in risk areas, i.e., over inclined terrain or potentially flooded areas on the borders of rivers; (2) the buildings are made with some cheap row material mixed with traditional materials; (3) the distribution of short and long wave radiation is conditioned by the inclination of the terrain, geometry of the buildings, materials and population density; (4) the exclusion of many common living areas; (5) intense or free thermal convection is found over the urban surface on the diurnal time with impact in the Atmospheric Boundary Layer dynamics; (6) high levels of airborne pollutants are found; etc. The proposed numerical scheme is designed to contribute with the current tools used to forecast the impact of convective precipitations in the risk areas of São Paulo City.

Virus-based surface patterning of biological molecules, probes, and inorganic materials.

PubMed

Ahn, Suji; Jeon, Seongho; Kwak, Eun-A; Kim, Jong-Man; Jaworski, Justyn

2014-10-01

An essential requirement for continued technological advancement in many areas of biology, physics, chemistry, and materials science is the growing need to generate custom patterned materials. Building from recent achievements in the site-specific modification of virus for covalent surface tethering, we show in this work that stable 2D virus patterns can be generated in custom geometries over large area glass surfaces to yield templates of biological, biochemical, and inorganic materials in high density. As a nanomaterial building block, filamentous viruses have been extensively used in recent years to produce materials with interesting properties, owing to their ease of genetic and chemical modification. By utilizing un-natural amino acids generated at specific locations on the filamentous fd bacteriophage protein coat, surface immobilization is carried out on APTES patterned glass resulting in precise geometries of covalently linked virus material. This technique facilitated the surface display of a high density of virus that were labeled with biomolecules, fluorescent probes, and gold nanoparticles, thereby opening the possibility of integrating virus as functional components for surface engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

Heterogenous Material Integration and Band Engineering With Type II Superlattice

DTIC Science & Technology

2015-10-26

tunneling or surface effects. A careful variable area diode study is needed to investigate the effect of surfaces in this low temperature regime. In the mid...theoretically predicted advantages of T2SL over bulk MCT detectors, including lower tunneling currents [1] and suppressed Auger recombination rates [2...The tunneling currents are also reduced due to significant reduction in field drop. Thus the device can be made diffusion limited over wide range of

The U.S. Geological Survey Coal Hydrology Program and the potential of hydrologic models for impact assessments

USGS Publications Warehouse

Doyle, W. Harry

1981-01-01

A requirement of Public Law 95-87, the Surface Mining Control and Reclamation Act of 1977, is the understanding of the hydrology in actual and proposed surface-mined areas. Surface-water data for small specific-sites and for larger areas such as adjacent and general areas are needed also to satisfy the hydrologic requirements of the Act. The Act specifies that surface-water modeling techniques may be used to generate the data and information. The purpose of this report is to describe how this can be achieved for smaller watersheds. This report also characterizes 12 ' state-of-the-art ' strip-mining assessment models that are to be tested with data from two data-intensive studies involving small watersheds in Tennessee and Indiana. Watershed models are best applied to small watersheds with specific-site data. Extending the use of modeling techniques to larger watersheds remains relatively untested, and to date the upper limits for application have not been established. The U.S. Geological Survey is currently collecting regional hydrologic data in the major coal provinces of the United States and this data will be used to help satisfy the ' general-area ' data requirements of the Act. This program is reviewed and described in this report. (USGS)

Investigation of the effect of tablet surface area/volume on drug release from hydroxypropylmethylcellulose controlled-release matrix tablets.

PubMed

Reynolds, Thomas D; Mitchell, Shawn A; Balwinski, Karen M

2002-04-01

The purpose of this study was to investigate the influence of tablet surface area/volume (SA/Vol) on drug release from controlled-release matrix tablets containing hydroxypropylmethylcellulose (HPMC). Soluble drugs (promethazine HCl, diphenhydramine HCl, and propranolol HCl) were utilized in this study to give predominantly diffusion-controlled release. Drug release from HPMC matrix tablets with similar values of SA/Vol was comparable within the same tablet shape (i.e., flat-faced round tablets) and among different shapes (i.e., oval, round concave, flat-faced beveled-edge, and flat-faced round tablets). Tablets having the same surface area but different SA/Vol values did not result in similar drug release; tablets with larger SA/Vol values hadfaster release profiles. Utility of SA/Vol to affect drug release was demonstrated by changing drug doses, and altering tablet shape to adjust SA/Vol. When SA/Vol was held constant, similar release profiles were obtained with f2 metric values greater than 70. Thus, surface area/volume is one of the key variables in controlling drug release from HPMC matrix tablets. Proper use of this variable has practical application by formulators who may need to duplicate drug release profiles from tablets of different sizes and different shapes.

Publications of the Western Earth Surface Processes Team 2006

USGS Publications Warehouse

Powell, Charles L.; Stone, Paul

2007-01-01

The Western Earth Surface Processes Team (WESPT) of the U.S. Geological Survey (USGS) conducts geologic mapping, earth-surface process investigations, and related topical earth science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, landslides and other potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2006 included southern California, the San Francisco Bay region, the Mojave Desert, the Colorado Plateau region of northern Arizona, and the Pacific Northwest. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. This compilation gives the bibliographical citations for 123 new publications, most of which are available online using the hyperlinks provided.

Evaluation of a moderate resolution, satellite-based impervious surface map using an independent, high-resolution validation data set

USGS Publications Warehouse

Jones, J.W.; Jarnagin, T.

2009-01-01

Given the relatively high cost of mapping impervious surfaces at regional scales, substantial effort is being expended in the development of moderate-resolution, satellite-based methods for estimating impervious surface area (ISA). To rigorously assess the accuracy of these data products high quality, independently derived validation data are needed. High-resolution data were collected across a gradient of development within the Mid-Atlantic region to assess the accuracy of National Land Cover Data (NLCD) Landsat-based ISA estimates. Absolute error (satellite predicted area - "reference area") and relative error [satellite (predicted area - "reference area")/ "reference area"] were calculated for each of 240 sample regions that are each more than 15 Landsat pixels on a side. The ability to compile and examine ancillary data in a geographic information system environment provided for evaluation of both validation and NLCD data and afforded efficient exploration of observed errors. In a minority of cases, errors could be explained by temporal discontinuities between the date of satellite image capture and validation source data in rapidly changing places. In others, errors were created by vegetation cover over impervious surfaces and by other factors that bias the satellite processing algorithms. On average in the Mid-Atlantic region, the NLCD product underestimates ISA by approximately 5%. While the error range varies between 2 and 8%, this underestimation occurs regardless of development intensity. Through such analyses the errors, strengths, and weaknesses of particular satellite products can be explored to suggest appropriate uses for regional, satellite-based data in rapidly developing areas of environmental significance. ?? 2009 ASCE.

Aerocapture Inflatable Decelerator (AID)

NASA Technical Reports Server (NTRS)

Reza, Sajjad

2007-01-01

Forward Attached Inflatable Decelerators, more commonly known as inflatable aeroshells, provide an effective, cost efficient means of decelerating spacecrafts by using atmospheric drag for aerocapture or planetary entry instead of conventional liquid propulsion deceleration systems. Entry into planetary atmospheres results in significant heating and aerodynamic pressures which stress aeroshell systems to their useful limits. Incorporation of lightweight inflatable decelerator surfaces with increased surface-area footprints provides the opportunity to reduce heat flux and induced temperatures, while increasing the payload mass fraction. Furthermore, inflatable aeroshell decelerators provide the needed deceleration at considerably higher altitudes and Mach numbers when compared with conventional rigid aeroshell entry systems. Inflatable aeroshells also provide for stowage in a compact space, with subsequent deployment of a large-area, lightweight heatshield to survive entry heating. Use of a deployable heatshield decelerator not only enables an increase in the spacecraft payload mass fraction and but may also eliminate the need for a spacecraft backshell and cruise stage. This document is the viewgraph slides for the paper's presentation.

Assessing implicit models for nonpolar mean solvation forces: The importance of dispersion and volume terms

PubMed Central

Wagoner, Jason A.; Baker, Nathan A.

2006-01-01

Continuum solvation models provide appealing alternatives to explicit solvent methods because of their ability to reproduce solvation effects while alleviating the need for expensive sampling. Our previous work has demonstrated that Poisson-Boltzmann methods are capable of faithfully reproducing polar explicit solvent forces for dilute protein systems; however, the popular solvent-accessible surface area model was shown to be incapable of accurately describing nonpolar solvation forces at atomic-length scales. Therefore, alternate continuum methods are needed to reproduce nonpolar interactions at the atomic scale. In the present work, we address this issue by supplementing the solvent-accessible surface area model with additional volume and dispersion integral terms suggested by scaled particle models and Weeks–Chandler–Andersen theory, respectively. This more complete nonpolar implicit solvent model shows very good agreement with explicit solvent results and suggests that, although often overlooked, the inclusion of appropriate dispersion and volume terms are essential for an accurate implicit solvent description of atomic-scale nonpolar forces. PMID:16709675

Rapid Startup and Loading of an Attached Growth, Simultaneous Nitrification/Denitrification Membrane Aerated Bioreactor

NASA Technical Reports Server (NTRS)

Meyer, Caitlin; Vega, Leticia

2014-01-01

The Membrane Aerated Bioreactor (MABR) is an attached-growth biological system for simultaneous nitrification and denitrification. This design is an innovative approach to common terrestrial wastewater treatments for nitrogen and carbon removal. Implementing a biologically-based water treatment system for long-duration human exploration is an attractive, low energy alternative to physiochemical processes. Two obstacles to implementing such a system are (1) the "start-up" duration from inoculation to steady-state operations and (2) the amount of surface area needed for the biological activity to occur. The Advanced Water Recovery Systems (AWRS) team at JSC explored these two issues through two tests; a rapid inoculation study and a wastewater loading study. Results from these tests demonstrate that the duration from inoculation to steady state can be reduced to two weeks and that the surface area to volume ratio baseline used in the Alternative Water Processor (AWP) test was higher than what was needed to remove the organic carbon and ammonium from the system.

Divergent opinions on surface disinfection: myths or prevention? A review of the literature

PubMed Central

Exner, Martin

2007-01-01

Virtually no prevention strategy in hospital hygiene has been the focus of such frequent controversial discussions as the role of surface disinfection. Set against that background, the Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute founded a working group comprising members with divergent views of risk evaluation as regards the role of disinfection. This working group produced a most carefully drafted guideline on how to deal with various risk areas and also incorporated a new provision into the guideline, stating that: “Cleaning and disinfection procedures must be organized and implemented such that there is no increase in the microbial load or spread of facultatively pathogenic or pathogenic microorganisms on surfaces.” Numerous studies have come to the conclusion that surface disinfection constitutes a basic infection control measure with which the spread of pathogens can be controlled. Conversely, when using only detergents such a form of control is not possible, something that must be taken into account in future when engaging in risk evaluation and formulating infection control measures. In view of the burgeoning trend in, for example, norovirus outbreaks, also in hospitals and nursing homes, such insights are of paramount importance and attest to the need for disinfection of surfaces and of areas with frequent hand and skin contacts. This discussion about the need for surface disinfection has, in addition to causing confusion among users, led to a decline in the willingness to accept hygienic practices, thus increasing the risk of occurrence of nosocomial infections as well as of antibiotic-resistant microorganisms. PMID:20200680

Divergent opinions on surface disinfection: myths or prevention? A review of the literature.

PubMed

Exner, Martin

2007-09-13

Virtually no prevention strategy in hospital hygiene has been the focus of such frequent controversial discussions as the role of surface disinfection. Set against that background, the Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute founded a working group comprising members with divergent views of risk evaluation as regards the role of disinfection. This working group produced a most carefully drafted guideline on how to deal with various risk areas and also incorporated a new provision into the guideline, stating that: "Cleaning and disinfection procedures must be organized and implemented such that there is no increase in the microbial load or spread of facultatively pathogenic or pathogenic microorganisms on surfaces."Numerous studies have come to the conclusion that surface disinfection constitutes a basic infection control measure with which the spread of pathogens can be controlled. Conversely, when using only detergents such a form of control is not possible, something that must be taken into account in future when engaging in risk evaluation and formulating infection control measures. In view of the burgeoning trend in, for example, norovirus outbreaks, also in hospitals and nursing homes, such insights are of paramount importance and attest to the need for disinfection of surfaces and of areas with frequent hand and skin contacts. This discussion about the need for surface disinfection has, in addition to causing confusion among users, led to a decline in the willingness to accept hygienic practices, thus increasing the risk of occurrence of nosocomial infections as well as of antibiotic-resistant microorganisms.

Mapping and analyzing change of impervious surface for two decades using multi-temporal Landsat imagery in Missouri

NASA Astrophysics Data System (ADS)

Zhou, Bo; He, Hong S.; Nigh, Timothy A.; Schulz, John H.

2012-08-01

Human population growth and associated sprawl has rapidly converted open lands to developed use and affected their distinctive ecological characteristics. Missouri reflects a full range of sprawl characteristics that include large metropolitan centers, which led growth in 1980s, and smaller metropolitan and rural areas, which led growth in 1990s. In order to study the historical patterns of sprawl, there is a need to quantitatively and geographically depict the extent and density of impervious surface for three time periods of 1980, 1990, and 2000 for the entire state of Missouri. We mapped impervious surface using Sub-pixel Classifier™, an add-on module of Erdas Imagine for the three time periods, where impervious surface growth was derived as the subtraction of impervious surface mapped from the different time periods. Accuracy assessment was performed by comparing satellite derived impervious surface images with ground-truth acquired from high resolution air photos. Results show that during 1980-2000, 129,853 ha of land were converted to impervious surface. Sprawl was prominent on urban fringe (within the urban boundaries) during 1980s with 23,674 ha of land converted to impervious surface compared to 22,918 ha in 1990s. There was a temporal shift in the rural landscapes (outside the urban boundaries) in the 1990s with 48,079 ha of land converted to impervious surface compared to 35,180 ha in 1980s. Major findings based on analysis of the impervious surface growth include: (i) new growth of impervious surfaces are concentrated on areas with 0.5-1.0% road cover; (ii) most new growths are either inside or close to urban watersheds; and (iii) most new growths are either inside or close to counties with metropolitan cities. This research goes beyond the usual hot spots of metropolitan areas to include rural landscapes where negative impact was exerted to the ecosystem due to the low density development and larger affected areas.

Design of open rectangular and trapezoidal channels

NASA Astrophysics Data System (ADS)

González, C. P.; Vera, P. E.; Carrillo, G.; García, S.

2018-04-01

In this work, the results of designing open channels in rectangular and trapezoidal form are presented. For the development of the same important aspects were taken as determination of flows by means of formula of the rational method, area of the surface for its implementation, optimal form of the flow to meet the needs of that environment. In the design the parameter of the hydraulic radius expressed in terms of the hydraulic area and wet perimeter was determined, considering that the surface on which the fluid flows is the product of the perimeter of the section and the length of the channel and where shear is generated by the condition of no slippage.

Percolation characteristics of solvent invasion in rough fractures under miscible conditions

NASA Astrophysics Data System (ADS)

Korfanta, M.; Babadagli, T.; Develi, K.

2017-10-01

Surface roughness and flow rate effects on the solvent transport under miscible conditions in a single fracture are studied. Surface replicas of seven different rocks (marble, granite, and limestone) are used to represent different surface roughness characteristics each described by different mathematical models including three fractal dimensions. Distribution of dyed solvent is investigated at various flow rate conditions to clarify the effect of roughness on convective and diffusive mixing. After a qualitative analysis using comparative images of different rocks, the area covered by solvent with respect to time is determined to conduct a semi-quantitative analysis. In this exercise, two distinct zones are identified, namely the straight lines obtained for convective (early times) and diffusive (late times) flow. The bending point between these two lines is used to point the transition between the two zones. Finally, the slopes of the straight lines and the bending points are correlated to five different roughness parameters and the rate (Peclet number). It is observed that both surface roughness and flow rate have significant effect on solvent spatial distribution. The largest area covered is obtained at moderate flow rates and hence not only the average surface roughness characteristic is important, but coessentially total fracture surface area needs to be considered when evaluating fluid distribution. It is also noted that the rate effect is critically different for the fracture samples of large grain size (marbles and granite) compared to smaller grain sizes (limestones). Variogram fractal dimension exhibits the strongest correlation with the maximum area covered by solvent, and display increasing trend at the moderate flow rates. Equations with variogram surface fractal dimension in combination with any other surface fractal parameter coupled with Peclet number can be used to predict maximum area covered by solvent in a single fracture, which in turn can be utilized to model oil recovery, waste disposal, and groundwater contamination processes in the presence of fractures.

Improved AFM Mapping of ICF Target Surfaces

NASA Astrophysics Data System (ADS)

Olson, D. K.; Drake, T.; Frey, D.; Huang, H.; Stephens, R. B.

2003-10-01

Targets for Inertial Confinement Fusion (ICF) research are made from spherical shells with very strict requirements on surface smoothness. Hydrodynamic instabilities are amplified by the presence of surface defects, greatly reducing the gain of ICF targets. Sub-micron variations in the surface can be examined using an Atomic Force Microscope. The current sphere mapping assembly at General Atomics is designed to trace near the equator of a rotating sphere under the AFM head. Spheres are traced on three mutually orthogonal planes. The ˜10 mm piezo-electric actuator range limits how far off the equator we can scan spheres of millimeter diameter. Because only a small fraction of the target's surface can be covered, localized high-mode defects are difficult to detect. In order to meet the needs of ICF research, we need to scan more surface area of the sphere with the AFM. By integrating an additional stepping motor to the sphere mapping assembly, we will be able to recenter the piezo driver of the AFM while mapping. This additional ability allows us to increase the amount of the sphere's surface we are able to scan with the AFM by extending the range of the AFM from the sphere's equator.

Center for Advanced Sensors, Year One Funding (FY2005)

DTIC Science & Technology

2006-10-30

on a plane and located near a planar wall. The box is a tank-sized box and the wall can represent a building or a tree line, depending on what...antenna is needed to geometrically couple the large spot to the small detector. As in all focal plane arrays, surface area is required to route...area at the antennae plane . Current antenna implementations for focal plane arrays emphasize frequency independent and modifications of frequency

(Quasi-) 2D aggregation of polystyrene-b-dextran at the air-water interface.

PubMed

Bosker, Wouter T E; Cohen Stuart, Martien A; Norde, Willem

2013-02-26

Polystyrene-b-dextran (PS-b-Dextran) copolymers can be used to prepare dextran brushes at solid surfaces, applying Langmuir-Blodgett deposition. When recording the interfacial pressure versus area isotherms of a PS-b-Dextran monolayer, time-dependent hysteresis was observed upon compression and expansion. We argue that this is due to (quasi-) 2D aggregation of the copolymer at the air-water surface, with three contributions. First, at large area per molecule, a zero surface pressure is measured; we ascribe this to self-assembly of block copolymers into surface micelles. At intermediate area we identify a second regime ("desorption regime") where aggregation into large patches occurs due to van der Waals attraction between PS blocks. At high surface pressure ("brush regime") we observe hysteretic behavior attributed to H-bonding between dextran chains. When compared to hysteresis of other amphiphilic diblock copolymers (also containing PS, e.g., polystyrene-b-poly(ethylene oxide)) a general criterion can be formulated concerning the extent of hysteresis: when the hydrophobic (PS) block is of equal size as (or bigger than) the hydrophilic block, the hysteresis is maximal. The (quasi-) 2D aggregation of PS-b-Dextran has significant implications for the preparation of dextran brushes at solid surfaces using Langmuir-Blodgett deposition. For each grafting density the monolayer needs to relax, up to several hours, prior to transfer.

Characteristics of Surface Urban Heat Island (SUHI) over the Gangetic Plain of Bihar, India

NASA Astrophysics Data System (ADS)

Barat, Archisman; Kumar, Sunny; Kumar, Praveen; Parth Sarthi, P.

2018-05-01

The rapid urbanisation impacts on environment, climate, agriculture, water resources trigger several problems to human beings. The present study is carried out to estimate intensity and trend of Urban Heat Island (UHI) as Surface UHI (SUHI) over towns/cities of the Gangetic plain of the state of Bihar, India, in which urban areas show relatively greater Land Surface Temperature (LST) than its rural surroundings especially during night times. The LST data (2001-14) of Moderate Resolution Imaging Spectroradiometer (MODIS) is used for five major towns/cities of Bihar namely, Bhagalpur, Gaya, Patna, Purnea and Muzzaffarpur. Each city is classified into Urban, Suburban and Rural zones as per land cover of the area. During winter months (January, February, November and December), UHI is more intense over all towns/cities. Mann-Kendall Test is applied on Surface Urban Heat Island Intensity (SUHII) in which MK-Test Statistic (S) shows a significant increasing trend. This trend would alarm a risk to increase in air pollution, heat related biohazards, energy demand in the region. This study shows the need of urban greening and proper town planning over the considered areas to mitigate the changes.

Stereoplotting Hominid Brain Endocasts : Some Preliminary Results

NASA Astrophysics Data System (ADS)

Holloway, Ralph L.

1980-07-01

To objectively and quantitatively demonstrate regional differences in brain endocast morphology, traditional anthropometric caliper measurements must be replaced by a system providing not only localness, but homology and reasonable freedom from allometric distortion. Stereoplotting the radial distances from endocast surface (the closest point to the once underlying brain cortex) to a homologous center every ten degrees provides some 300+ data points for each dorsal endocast surface, thus giving the requisite localness. These measurements provide a large matrix of data suitable for a number of multivariate statistical techniques, and the translation of such data and analyses to readily visualized maps, which can then be compared in relation to both taxonomic and functional knowledge about the cerebral surface. This paper descri-bes some preliminary results from using such methods on a sample of 64 undistorted endocasts composed of both pongids and fossil hominids. While sample sizes within taxonomic groups need to be augmented, the preliminary and tentative pilot studies conducted so far suggest that the method has excellent potential, and that two major areas of the brain endocast surface show the greatest shape changes : 1) the posterior association areas (inferior parietal lobule); 2) the anterior prefrontal areas.

UV 380 nm Reflectivity of the Earth's Surface

NASA Technical Reports Server (NTRS)

Herman, J. R.; Celarier, E.; Larko, D.

2000-01-01

The 380 nm radiance measurements of TOMS (Total Ozone Mapping Spectrometer) have been converted into a global data set of daily (1979 to 1992) Lambert equivalent reflectivities R of the Earth's surface and boundary layer (clouds, aerosols, surface haze, and snow/ice). Since UV surface reflectivity is between 2 and 8% for both land and water during all seasons of the year (except for ice and snow cover), reflectivities larger than the surface value indicates the presence of clouds, haze, or aerosols in the satellite field of view. Statistical analysis of 14 years of daily data show that most snow/ice-free regions of the Earth have their largest fraction of days each year when the reflectivity is low (R less than 10%). The 380 nm reflectivity data shows that the true surface reflectivity is 2 to 3% lower than the most frequently occurring reflectivity value for each TOMS scene. The most likely cause of this could be a combination of frequently occurring boundary-layer water or aerosol haze. For most regions, the observation of extremely clear conditions needed to estimate the surface reflectivity from space is a comparatively rare occurrence. Certain areas (e.g., Australia, southern Africa, portions of northern Africa) are cloud-free more than 80% of the year, which exposes these regions to larger amounts of UV radiation than at comparable latitudes in the Northern Hemisphere. Regions over rain-forests, jungle areas, Europe and Russia, the bands surrounding the Arctic and Antarctic regions, and many ocean areas have significant cloud cover (R greater than 15%) more than half of each year. In the low to middle latitudes, the areas with the heaviest cloud cover (highest reflectivity for most of the year) are the forest areas of northern South America, southern Central America, the jungle areas of equatorial Africa, and high mountain regions such as the Himalayas or the Andes. The TOMS reflectivity data show the presence of large nearly clear ocean areas and the effects of the major ocean currents on cloud production.

UV 380 nm reflectivity of the Earth's surface, clouds and aerosols

NASA Astrophysics Data System (ADS)

Herman, J. R.; Celarier, E.; Larko, D.

2001-03-01

The 380 nm radiance measurements of the Total Ozone Mapping Spectrometer (TOMS) have been converted into a global data set of daily (1979-1992) Lambert equivalent reflectivities R of the Earth's surface and boundary layer (clouds, aerosols, surface haze, and snow/ice) and then corrected to RPC for the presence of partly clouded scenes. Since UV surface reflectivity is between 2 and 8% for both land and water during all seasons of the year (except for ice and snow cover), reflectivities larger than the surface value indicate the presence of clouds, haze, or aerosols in the satellite field of view. A statistical analysis of 14 years of daily reflectivity data shows that most snow-/ice-free scenes observed by TOMS have a reflectivity less than 10% for the majority of days during a year. The 380 nm reflectivity data show that the true surface reflectivity is 2-3% lower than the most frequently occurring reflectivity value for each TOMS scene as seen from space. Most likely the cause is a combination of frequently occurring boundary layer water and/or aerosol haze. For most regions the observation of extremely clear conditions needed to estimate the surface reflectivity from space is a comparatively rare occurrence. Certain areas (e.g., Australia, southern Africa, portions of northern Africa) are cloud-free more than 80% of the year, which exposes these regions to larger amounts of UV radiation than at comparable latitudes in the Northern Hemisphere. Regions over rain forests, jungle areas, Europe and Russia, the bands surrounding the Arctic and Antarctic regions, and many ocean areas have significant cloud cover (R>15%) more than half of each year. In the low to middle latitudes the areas with the heaviest cloud cover (highest reflectivity for most of the year) are the forest areas of northern South America, southern Central America, the jungle areas of equatorial Africa, and high mountain regions such as the Himalayas or the Andes. The TOMS reflectivity data show both the presence of large nearly clear ocean areas and the effects of the major ocean currents on cloud production.

Plasma Surface Interactions Common to Advanced Fusion Wall Materials and EUV Lithography - Lithium and Tin

NASA Astrophysics Data System (ADS)

Ruzic, D. N.; Alman, D. A.; Jurczyk, B. E.; Stubbers, R.; Coventry, M. D.; Neumann, M. J.; Olczak, W.; Qiu, H.

2004-09-01

Advanced plasma facing components (PFCs) are needed to protect walls in future high power fusion devices. In the semiconductor industry, extreme ultraviolet (EUV) sources are needed for next generation lithography. Lithium and tin are candidate materials in both areas, with liquid Li and Sn plasma material interactions being critical. The Plasma Material Interaction Group at the University of Illinois is leveraging liquid metal experimental and computational facilities to benefit both fields. The Ion surface InterAction eXperiment (IIAX) has measured liquid Li and Sn sputtering, showing an enhancement in erosion with temperature for light ion bombardment. Surface Cleaning of Optics by Plasma Exposure (SCOPE) measures erosion and damage of EUV mirror samples, and tests cleaning recipes with a helicon plasma. The Flowing LIquid surface Retention Experiment (FLIRE) measures the He and H retention in flowing liquid metals, with retention coefficients varying between 0.001 at 500 eV to 0.01 at 4000 eV.

Atmospheric effect on classification of finite fields. [satellite-imaged agricultural areas

NASA Technical Reports Server (NTRS)

Kaufman, Y. J.; Fraser, R. S.

1984-01-01

The atmospheric effect on the upward radiance of sunlight scattered from the earth-atmosphere system is strongly influenced by the contrasts between fields and their sizes. In this paper, the radiances above finite fields are computed to simulate radiances measured by a satellite. A simulation case including 11 agricultural fields and four natural fields (water, soil, savanah, and forest) is used to test the effect of field size, background reflectance, and optical thickness of the atmosphere on the classification accuracy. For a given atmospheric turbidity, the atmospheric effect on classification of surface features may be much stronger for nonuniform surfaces than for uniform surfaces. Therefore, the classification accuracy of agricultural fields and urban areas is dependent not only on the optical characteristics of the atmosphere, but also on the size of the surface elements to be classified and their contrasts. It is concluded that new atmospheric correction methods, which take into account the finite size of the fields, are needed.

Potentiometric surface of the Ozark aquifer in northern Arkansas, 2010

USGS Publications Warehouse

Czarnecki, John B.; Pugh, Aaron L.; Blackstock, Joshua M.

2014-01-01

The Ozark aquifer in northern Arkansas is composed of dolomite, limestone, sandstone, and shale of Late Cambrian to Middle Devonian age and ranges in thickness from approximately 1,100 feet to more than 4,000 feet. Hydrologically, the aquifer is complex, characterized by discrete and discontinuous flow components with large variations in permeability. The potentiometric-surface map, based on 56 well and 5 spring water-level measurements made in 2010 in Arkansas and Missouri, has a maximum water-level altitude measurement of 1,174 feet in Carroll County and a minimum water-level altitude measurement of 120 feet in Randolph County. Regionally, the flow within the aquifer is to the south and southeast in the eastern and central part of the study area and to the west, northwest, and north in the western part of the study area. Water-level altitudes changed 0.5 feet or less in 31 out of 56 wells measured between 2007 and 2010. Despite rapidly increasing population within the study area, the increase appears to have minimal effect on groundwater levels, although the effect may have been minimized by the development and use of surface-water distribution infrastructure, suggesting that most of the incoming populations are fulfilling their water needs from surface-water sources. The conversion of some users from groundwater to surface water may be allowing water levels in some wells to recover (rise) or decline at a slower rate in some areas such as in Benton, Carroll, and Washington Counties.

Cleaning and disinfecting environmental surfaces in health care: Toward an integrated framework for infection and occupational illness prevention.

PubMed

Quinn, Margaret M; Henneberger, Paul K; Braun, Barbara; Delclos, George L; Fagan, Kathleen; Huang, Vanthida; Knaack, Jennifer L S; Kusek, Linda; Lee, Soo-Jeong; Le Moual, Nicole; Maher, Kathryn A E; McCrone, Susan H; Mitchell, Amber Hogan; Pechter, Elise; Rosenman, Kenneth; Sehulster, Lynne; Stephens, Alicia C; Wilburn, Susan; Zock, Jan-Paul

2015-05-01

The Cleaning and Disinfecting in Healthcare Working Group of the National Institute for Occupational Safety and Health, National Occupational Research Agenda, is a collaboration of infection prevention and occupational health researchers and practitioners with the objective of providing a more integrated approach to effective environmental surface cleaning and disinfection (C&D) while protecting the respiratory health of health care personnel. The Working Group, comprised of >40 members from 4 countries, reviewed current knowledge and identified knowledge gaps and future needs for research and practice. An integrated framework was developed to guide more comprehensive efforts to minimize harmful C&D exposures without reducing the effectiveness of infection prevention. Gaps in basic knowledge and practice that are barriers to an integrated approach were grouped in 2 broad areas related to the need for improved understanding of the (1) effectiveness of environmental surface C&D to reduce the incidence of infectious diseases and colonization in health care workers and patients and (2) adverse health impacts of C&D on health care workers and patients. Specific needs identified within each area relate to basic knowledge, improved selection and use of products and practices, effective hazard communication and training, and safer alternatives. A more integrated approach can support multidisciplinary teams with the capacity to maximize effective and safe C&D in health care. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. All rights reserved.

The impact of extensive green roofs on the improvement of thermal performance for urban areas in Mediterranean climate with reference to the city of Jijel in Algeria

NASA Astrophysics Data System (ADS)

Lehtihet, M. C.; Bouchair, A.

2018-05-01

Buildings with dark surfaces, concrete and pavement, needed for the expansion of cities, absorb huge amounts of heat, increasing the mean radiant temperatures of urban areas and offer significant potential for urban heat island (UHI) effect. The purpose of this work is to investigate the impact of green roofs on the improvement of urban heat performance in Mediterranean climate. A field investigation is carried out using two large-scale modules built in the city of Jijel in the north of Algeria. The first is a bare reinforced concrete slab whereas the second is covered with ivy plants. The experimental site, the air and surface temperature parameters and the various measurement points at the level of the modules are chosen. Measurements are performed using thermo-hygrometer, surface sensors and data acquisition apparatus. The results show that green roofs can be a potential mean of improving the thermal performance of the surrounding microclimate and energy performance of buildings in an urban area. The green roof could be an encouraging strategy against urban heat island effect not only for Mediterranean cities but also for other areas.

Use of ERTS-1 pictures in coastal oceanography in British Columbia

NASA Technical Reports Server (NTRS)

Gower, J. F. R.

1973-01-01

The ERTS-1 color composite picture of the Vancouver-Victoria region illustrates the value of ERTS data for coastal oceanography. The water of the Fraser River plume which is so clearly visible in the center of the scene has been of interest to oceanographers on the west coast of Canada for a long time as an easily visible tracer of surface water circulation in the strait of Georgia. Maps of the plume at different states of the tide and with different river flow and weather were compiled from oblique aerial photographs in 1950 and used in the siting of sewage and other outfalls in the Vancouver area. More recently high level aerial photomosaics have been used to map the plume area, but the plume can spread over distances of 30 to 40 miles and many photographs, with the uneven illumination inherent in wide angle coverage, are needed for the mosaic. The ERTS satellite gives the first complete view of the plume area. Electronic enhancement of the images shows that the satellite's narrow angle coverage allows very weak surface turbidity features to be made visible to give information on surface currents over a wide area.

Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 415: Project 57 No. 1 Plutonium Dispersion (NTTR), Nevada, Revision 0

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

Matthews, Patrick; Burmeister, Mark

2014-04-01

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 415, Project 57 No. 1 Plutonium Dispersion (NTTR). CAU 415 is located on Range 4808A of the Nevada Test and Training Range (NTTR) and consists of one corrective action site: NAFR-23-02, Pu Contaminated Soil. The CAU 415 site consists of the atmospheric release of radiological contaminants to surface soil from the Project 57 safety experiment conducted in 1957. The safety experiment released plutonium (Pu), uranium (U), and americium (Am) to the surface soil over an area of approximately 1.9 squaremore » miles. This area is currently fenced and posted as a radiological contamination area. Vehicles and debris contaminated by the experiment were subsequently buried in a disposal trench within the surface-contaminated, fenced area and are assumed to have released radiological contamination to subsurface soils. Potential source materials in the form of pole-mounted electrical transformers were also identified at the site and will be removed as part of closure activities.« less

A method of multi-view intraoral 3D measurement

NASA Astrophysics Data System (ADS)

Zhao, Huijie; Wang, Zhen; Jiang, Hongzhi; Xu, Yang; Lv, Peijun; Sun, Yunchun

2015-02-01

In dental restoration, its important to achieve a high-accuracy digital impression. Most of the existing intraoral measurement systems can only measure the tooth from a single view. Therfore - if we are wilng to acquire the whole data of a tooth, the scans of the tooth from multi-direction ad the data stitching based on the features of the surface are needed, which increases the measurement duration and influence the measurement accuracy. In this paper, we introduce a fringe-projection based on multi-view intraoral measurement system. It can acquire 3D data of the occlusal surface, the buccal surface and the lingual surface of a tooth synchronously, by using a senor with three mirrors, which aim at the three surfaces respectively and thus expand the measuring area. The constant relationship of the three mirrors is calibrated before measurement and can help stitch the data clouds acquired through different mirrors accurately. Therefore the system can obtain the 3D data of a tooth without the need to measure it from different directions for many times. Experiments proved the availability and reliability of this miniaturized measurement system.

Thin film passivation of laser generated 3D micro patterns in lithium manganese oxide cathodes

NASA Astrophysics Data System (ADS)

Pröll, J.; Kohler, R.; Bruns, M.; Oberst, V.; Weidler, P. G.; Heißler, S.; Kübel, C.; Scherer, T.; Prang, R.; Seifert, H. J.; Pfleging, W.

2013-03-01

The increasing need for long-life lithium-ion batteries requires the further development of electrode materials. Especially on the cathode side new materials or material composites are needed to increase the cycle lifetime. On the one hand, spinel-type lithium manganese oxide is a promising candidate to be used as cathode material due to its non-toxicity, low cost and good thermal stability. On the other hand, the spinel structure suffers from change in the oxidation state of manganese during cycling which is also accompanied by loss of active material into the liquid electrolyte. The general trend is to enhance the active surface area of the cathode in order to increase lithium-ion mobility through the electrode/electrolyte interface, while an enhanced surface area will also promote chemical degradation. In this work, laser microstructuring of lithium manganese oxide thin films was applied in a first step to increase the active surface area. This was done by using 248 nm excimer laser radiation and chromium/quartz mask imaging techniques. In a second step, high power diode laser-annealing operating at a wavelength of 940 nm was used for forming a cubic spinel-like battery phase. This was verified by means of Raman spectroscopy and cyclic voltammetric measurements. In a last step, the laser patterned thin films were coated with indium tin oxide (ITO) layers with a thickness of 10 nm to 50 nm. The influence of the 3D surface topography as well as the ITO thickness on the electrochemical performance was studied by cyclic voltammetry. Post-mortem studies were carried out by using scanning electron microscopy and focused ion beam analysis.

Landscape characteristics affecting streams in urbanizing regions of the Delaware River Basin (New Jersey, New York, and Pennsylvania, U.S.)

USGS Publications Warehouse

Riva-Murray, K.; Riemann, R.; Murdoch, P.; Fischer, J.M.; Brightbill, R.

2010-01-01

Widespread and increasing urbanization has resulted in the need to assess, monitor, and understand its effects on stream water quality. Identifying relations between stream ecological condition and urban intensity indicators such as impervious surface provides important, but insufficient information to effectively address planning and management needs in such areas. In this study we investigate those specific landscape metrics which are functionally linked to indicators of stream ecological condition, and in particular, identify those characteristics that exacerbate or mitigate changes in ecological condition over and above impervious surface. The approach used addresses challenges associated with redundancy of landscape metrics, and links landscape pattern and composition to an indicator of stream ecological condition across a broad area of the eastern United States. Macroinvertebrate samples were collected during 2000-2001 from forty-two sites in the Delaware River Basin, and landscape data of high spatial and thematic resolution were obtained from photointerpretation of 1999 imagery. An ordination-derived 'biotic score' was positively correlated with assemblage tolerance, and with urban-related chemical characteristics such as chloride concentration and an index of potential pesticide toxicity. Impervious surface explained 56% of the variation in biotic score, but the variation explained increased to as high as 83% with the incorporation of a second land use, cover, or configuration metric at catchment or riparian scales. These include land use class-specific cover metrics such as percent of urban land with tree cover, forest fragmentation metrics such as aggregation index, riparian metrics such as percent tree cover, and metrics related to urban aggregation. Study results indicate that these metrics will be important to monitor in urbanizing areas in addition to impervious surface. ?? 2010 US Government.

Inducement of a spontaneously wrinkled polydimethylsiloxane surface and its potential as a cell culture substrate.

PubMed

Kim, Da Som; Lee, Ho Won; Lee, Jong Hyun; Kwon, Hyuck Gi; Lee, Sang Wook; Han, Seung Jin; Jeong, Ok Chan

2018-06-18

Spontaneous wrinkling of a polydimethylsiloxane (PDMS) surface was induced by repeated thermal shrinkage of liquid PDMS coated onto a cured PDMS layer. We investigated and evaluated the potential of the resulting surface as a cell culture substrate by monitoring the viability, spreading area, and proliferation rate of MG-63 cells cultured on native, wrinkled, and poly-L-lysine (PLL)-coated PDMS surfaces. Cells seeded on the wrinkled and PLL-coated PDMS surfaces spread and adhered better than those on native surfaces. The numbers of attached cells growing on wrinkled and PLL-coated PDMS surfaces were higher than those of cells on a native PDMS surface. The spreading area of cells on the wrinkled surface was similar to that of cells on the PLL-coated surface, and was much larger than that on native PDMS. The proliferation rate of cells on the wrinkled surface was more than double that of cells on native PDMS. Reverse-transcription polymerase chain reaction (RT-PCR) analysis of integrin mRNA expression showed that cells on the wrinkled surface were more tightly attached due to higher expression of the protein than exhibited in cells on native PDMS. Thus, the novel findings of this study are that the induction of a wrinkled PDMS surface through a simple curing process produces a suitable cell culture substrate without need of surface modification, and that its effectiveness is comparable to that of a PLL-coated PDMS surface. Copyright © 2018 Elsevier B.V. All rights reserved.

Land cover characterization and land surface parameterization research

USGS Publications Warehouse

Steyaert, Louis T.; Loveland, Thomas R.; Parton, William J.

1997-01-01

The understanding of land surface processes and their parameterization in atmospheric, hydrologic, and ecosystem models has been a dominant research theme over the past decade. For example, many studies have demonstrated the key role of land cover characteristics as controlling factors in determining land surface processes, such as the exchange of water, energy, carbon, and trace gases between the land surface and the lower atmosphere. The requirements for multiresolution land cover characteristics data to support coupled-systems modeling have also been well documented, including the need for data on land cover type, land use, and many seasonally variable land cover characteristics, such as albedo, leaf area index, canopy conductance, surface roughness, and net primary productivity. Recently, the developers of land data have worked more closely with the land surface process modelers in these efforts.

Near-infrared imaging of enamel hypomineralization due to developmental defects

NASA Astrophysics Data System (ADS)

Lee, Robert C.; Jang, Andrew; Fried, Daniel

2017-02-01

The increasing prevalence of mild hypomineralization due to developmental defects on tooth surfaces poses a challenge for caries detection and caries risk assessment and reliable methods need to be developed to discriminate such lesions from active caries lesions that need intervention. Previous studies have demonstrated that areas of hypomineralization are typically covered with a relatively thick surface layer of highly mineralized and transparent enamel similar to arrested lesions. Seventy-six extracted human teeth with mild to moderate degrees of suspicious fluorosis were imaged using near-infrared reflectance and transillumination. Enamel hypomineralization was clearly visible in both modalities. However, it was difficult to distinguish hypomineralization due to developmental defects from caries lesions with contrast measurements alone. The location of the lesion on tooth coronal surface (i.e. generalized vs. localized) seems to be the most important indicator for the presence of enamel hypomineralization due to developmental defects.

A Center for Extraterrestrial Engineering and Construction (CETEC)

NASA Technical Reports Server (NTRS)

Leigh, Gerald G.

1992-01-01

A group of knowledgeable scientists and engineers in New Mexico has recognized the need for such a testing capability and has proposed a project to evelop an extraterrestrial surface simulation facility. A group of universities, national laboratories, and private industrial firms is proposing to establish a Center for Extraterrestrial Engineering and Construction (CETEC) and to develop large extraterrestrial surface simulation facilities in which this needed testing can be realistically performed. The CETEC is envisioned to be both a center of knowledge and data regarding engineering, construction, mining, and material process operations on extraterrestrial bodies and a set of extraterrestrial surface simulation facilities. The primary CETEC facility is proposed to be a large domed building made of steel reinforced concrete with more than one acre of test floor area covered with several feet of simulated lunar soil and dust. Various aspects of the project are presented in viewgraph form.

Near-infrared imaging of enamel hypomineralization due to developmental defects.

PubMed

Lee, Robert C; Jang, Andrew; Fried, Daniel

2017-01-28

The increasing prevalence of mild hypomineralization due to developmental defects on tooth surfaces poses a challenge for caries detection and caries risk assessment and reliable methods need to be developed to discriminate such lesions from active caries lesions that need intervention. Previous studies have demonstrated that areas of hypomineralization are typically covered with a relatively thick surface layer of highly mineralized and transparent enamel similar to arrested lesions. Seventy-six extracted human teeth with mild to moderate degrees of suspicious fluorosis were imaged using near-infrared reflectance and transillumination. Enamel hypomineralization was clearly visible in both modalities. However, it was difficult to distinguish hypomineralization due to developmental defects from caries lesions with contrast measurements alone. The location of the lesion on tooth coronal surface (i.e. generalized vs. localized) seems to be the most important indicator for the presence of enamel hypomineralization due to developmental defects.

Safety Hazards in Child Care Settings. CPSC Staff Study.

ERIC Educational Resources Information Center

Consumer Product Safety Commission, Washington, DC.

Each year, thousands of children in child care settings are injured seriously enough to need emergency medical treatment. This national study identified potential safety hazards in 220 licensed child care settings in October and November 1998. Eight product areas were examined: cribs, soft bedding, playground surfacing, playground surface…

Benefit transfer with limited data: An application to recreational fishing losses from surface mining

EPA Science Inventory

The challenges of applying benefit transfer models to policy sites are often underestimated. Analysts commonly need to estimate site-specific effects for areas that lack data on the number of people who use the resource, intensity of use, and other relevant variables. Yet, the be...

75 FR 36587 - Proposed Revocation of Class E Airspace; Chillicotte, MO

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-28

... control facility management have determined that this airspace is no longer needed and would not... action proposes to remove Class E airspace at Chillicotte, MO. Airport management and air traffic control facility managers have determined that the Class E surface area at Chillicotte Municipal Airport is no...

Engineering potential for lunar missions after Apollo.

NASA Technical Reports Server (NTRS)

Burke, J. D.

1972-01-01

The need for continuing post-Apollo lunar research is defined by outlining problems in stellar, planetary, biological, and social evolution which require specific studies of the moon. Engineering capabilities existing immediately after the Apollo program are described in the areas of launch vehicles and spacecraft, lunar surface mobility, instrumentation, and communications.

41 CFR 102-85.35 - What definitions apply to this part?

Code of Federal Regulations, 2010 CFR

2010-07-01

... professional techniques of planning, layout and interior design to determine the best internal location and the..., due to its layout, design, location, or other characteristics, is unlikely to be needed by another GSA... space means surface land, structures, or areas within structures designed and designated for the purpose...

Innovative research in the design and operation of large telescopes for space: Aspects of giant telescopes in space

NASA Technical Reports Server (NTRS)

Angel, J. R. P.

1985-01-01

The capability and understanding of how to finish the reflector surfaces needed for large space telescopes is discussed. The technology for making very light glass substrates for mirrors is described. Other areas of development are in wide field imaging design for very fast primaries, in data analysis and retrieval methods for astronomical images, and in methods for making large area closely packed mosaics of solid state array detectors.

Energy exchanges in a Central Business District - Interpretation of Eddy Covariance and radiation flux measurements (London UK)

NASA Astrophysics Data System (ADS)

Kotthaus, S.; Grimmond, S.

2013-12-01

Global urbanisation brings increasingly dense and complex urban structures. To manage cities sustainably and smartly, currently and into the future under changing climates, urban climate research needs to advance in areas such as Central Business Districts (CBD) where human interactions with the environment are particularly concentrated. Measurement and modelling approaches may be pushed to their limits in dense urban settings, but if urban climate research is to contribute to the challenges of real cities those limits have to be addressed. The climate of cities is strongly governed by surface-atmosphere exchanges of energy, moisture and momentum. Observations of the relevant fluxes provide important information for improvement and evaluation of modelling approaches. Due to the CBD's heterogeneity, a very careful analysis of observations is required to understand the relevant processes. Current approaches used to interpret observations and set them in a wider context may need to be adapted for use in these more complex areas. Here, we present long-term observations of the radiation balance components and turbulent fluxes of latent heat, sensible heat and momentum in the city centre of London. This is one of the first measurement studies in a CBD covering multiple years with analysis at temporal scales from days to seasons. Data gathered at two sites in close vicinity, but with different measurement heights, are analysed to investigate the influence of source area characteristics on long-term radiation and turbulent fluxes. Challenges of source area modelling and the critical aspect of siting in such a complex environment are considered. Outgoing long- and short-wave radiation are impacted by the anisotropic nature of the urban surface and the high reflectance materials increasingly being used as building materials. Results highlight the need to consider the source area of radiometers in terms of diffuse and direct irradiance. Sensible heat fluxes (QH) are positive all year round, even at night. QH systematically exceeds input from net all-wave radiation (Q*), probably sustained by a both storage and anthropogenic heat fluxes (QF). Model estimates suggest QF can exceed the Q* nearly all year round. The positive QH inhibits stable conditions, but the stability classification is determined predominantly by the pattern of friction velocity over the rough urban surface. Turbulent latent heat flux variations are controlled (beyond the available energy) by rainfall due to the small vegetation cover. The Bowen ratio is mostly larger than one. Analysis of the eddy covariance footprint surface controls for the different land cover types by flow patterns for measurements at the two heights suggests the spatial variations of the sensible heat flux observed are partly related to changes in surface roughness, even at the local scale. Where the source areas are most homogeneous, flow conditions are vertically consistent - even if initial morphometric parameters suggested the measurements may be below the blending height. Turbulence statistics and momentum flux patterns prove useful for the interpretation of turbulent heat exchanges observed.

Design of an Airlift Bioreactor

DOE Data Explorer

Jiao, Yongqin; Park, Dan; Ho, Lewis

2017-03-13

An important consideration for the process design is cell immobilization-enabled flow-through operation. Large-scale biosorption relies on cells that are immobilized on a supporting substrate and used to 'attract' metal ions. Cell immobilization allows easy separation of the feed solution and REEs that are attached to the cell surface. It also allows continuous operation without the need of energy-intensive centrifugation or filtration. Lightweight, high surface area, low cost (~$200/m3) high-density polyethylene (HDPE) plastic disks are used as cell carriers for biofilm formation.

SiGe Based Low Temperature Electronics for Lunar Surface Applications

NASA Technical Reports Server (NTRS)

Mojarradi, Mohammad M.; Kolawa, Elizabeth; Blalock, Benjamin; Cressler, John

2012-01-01

The temperature at the permanently shadowed regions of the moon's surface is approximately -240 C. Other areas of the lunar surface experience temperatures that vary between 120 C and -180 C during the day and night respectively. To protect against the large temperature variations of the moon surface, traditional electronics used in lunar robotics systems are placed inside a thermally controlled housing which is bulky, consumes power and adds complexity to the integration and test. SiGe Based electronics have the capability to operate over wide temperature range like that of the lunar surface. Deploying low temperature SiGe electronics in a lander platform can minimize the need for the central thermal protection system and enable the development of a new generation of landers and mobility platforms with highly efficient distributed architecture. For the past five years a team consisting of NASA, university and industry researchers has been examining the low temperature and wide temperature characteristic of SiGe based transistors for developing electronics for wide temperature needs of NASA environments such as the Moon, Titan, Mars and Europa. This presentation reports on the status of the development of wide temperature SiGe based electronics for the landers and lunar surface mobility systems.

Thermal mapping, geothermal source location, natural effluents and plant stress in the Mediterranean coast of Spain

NASA Technical Reports Server (NTRS)

Delascuevas, R. N. (Principal Investigator); Dearagon, A. M.

1981-01-01

Data obtained by HCMM satellite over a complex area in eastern Spain were evaluated and found to be most useful in studying macrostructures in geology and in analyzing marine currents, layers, and areas (although other satellites provide more data). The upper scale to work with HCMM data appears to be 1:2.000.000. Techniques used in preprocessing, processing, and analyzing imagery are discussed as well as methods for pattern recognition. Surface temperatures obtained for soils, farmlands, forests, geological structures, and coastal waters are discussed. Suggestions are included for improvements needed to achieve better results in geographic areas similar to the study area.

Preliminary study of near surface detections at geothermal field using optic and SAR imageries

NASA Astrophysics Data System (ADS)

Kurniawahidayati, Beta; Agoes Nugroho, Indra; Syahputra Mulyana, Reza; Saepuloh, Asep

2017-12-01

Current remote sensing technologies shows that surface manifestation of geothermal system could be detected with optical and SAR remote sensing, but to assess target beneath near the surface layer with the surficial method needs a further study. This study conducts a preliminary result using Optic and SAR remote sensing imagery to detect near surface geothermal manifestation at and around Mt. Papandayan, West Java, Indonesia. The data used in this study were Landsat-8 OLI/TIRS for delineating geothermal manifestation prospect area and an Advanced Land Observing Satellite(ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) level 1.1 for extracting lineaments and their density. An assumption was raised that the lineaments correlated with near surface structures due to long L-band wavelength about 23.6 cm. Near surface manifestation prospect area are delineated using visual comparison between Landsat 8 RGB True Colour Composite band 4,3,2 (TCC), False Colour Composite band 5,6,7 (FCC), and lineament density map of ALOS PALSAR. Visual properties of ground object were distinguished from interaction of the electromagnetic radiation and object whether it reflect, scatter, absorb, or and emit electromagnetic radiation based on characteristic of their molecular composition and their macroscopic scale and geometry. TCC and FCC composite bands produced 6 and 7 surface manifestation zones according to its visual classification, respectively. Classified images were then compared to a Normalized Different Vegetation Index (NDVI) to obtain the influence of vegetation at the ground surface to the image. Geothermal area were classified based on vegetation index from NDVI. TCC image is more sensitive to the vegetation than FCC image. The later composite produced a better result for identifying visually geothermal manifestation showed by detail-detected zones. According to lineament density analysis high density area located on the peak of Papandayan overlaid with zone 1 and 2 of FCC. Comparing to the extracted lineament density, we interpreted that the near surface manifestation is located at zone 1 and 2 of FCC image.

An Improved MUSIC Model for Gibbsite Surfaces

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

Mitchell, Scott C.; Bickmore, Barry R.; Tadanier, Christopher J.

2004-06-01

Here we use gibbsite as a model system with which to test a recently published, bond-valence method for predicting intrinsic pKa values for surface functional groups on oxides. At issue is whether the method is adequate when valence parameters for the functional groups are derived from ab initio structure optimization of surfaces terminated by vacuum. If not, ab initio molecular dynamics (AIMD) simulations of solvated surfaces (which are much more computationally expensive) will have to be used. To do this, we had to evaluate extant gibbsite potentiometric titration data that where some estimate of edge and basal surface area wasmore » available. Applying BET and recently developed atomic force microscopy methods, we found that most of these data sets were flawed, in that their surface area estimates were probably wrong. Similarly, there may have been problems with many of the titration procedures. However, one data set was adequate on both counts, and we applied our method of surface pKa int prediction to fitting a MUSIC model to this data with considerable success—several features of the titration data were predicted well. However, the model fit was certainly not perfect, and we experienced some difficulties optimizing highly charged, vacuum-terminated surfaces. Therefore, we conclude that we probably need to do AIMD simulations of solvated surfaces to adequately predict intrinsic pKa values for surface functional groups.« less

Analysis of surface scale on the Ni-based superalloy CMSX-10N and proposed mechanism of formation

NASA Astrophysics Data System (ADS)

Simmonds, S.; D'Souza, N.; Ryder, K. S.; Dong, H.

2012-01-01

There is a continuing demand to raise the operating temperature of jet engine turbine blades to meet the need for higher turbine entry temperatures (TET) in order to increase thermal efficiency and thrust. Modern, high-pressure turbine blades are made from Ni-based superalloys in single-crystal form via the investment casting process. One important post-cast surface defect, known as 'surface scale', has been investigated on the alloy CMSX-10N. This is an area of distinct discolouration of the aerofoil seen after casting. Auger electron and X-ray photoelectron spectroscopy analysis were carried out on both scaled and un-scaled areas. In the scaled region, a thin layer (~800nm) of Ni oxide is evident. In the un-scaled regions there is a thicker Al2O3 layer. It is shown that, as the blade cools during casting, differential thermal contraction of mould and alloy causes the solid blade to 'detach' from the mould in these scaled areas. The formation of Ni Oxides is facilitated by this separation.

Fabrication and radio frequency test of large-area MgB 2 films on niobium substrates

DOE PAGES

Ni, Zhimao; Guo, Xin; Welander, Paul B.; ...

2017-01-19

Magnesium diboride (MgB 2) is a promising candidate material for superconducting radio frequency (RF) cavities because of its higher transition temperature and critical field compared with niobium. To meet the demand of RF test devices, the fabrication of large-area MgB 2 films on metal substrates is needed. Here, in this work, high quality MgB 2 films with 50 mm diameter were fabricated on niobium by using an improved HPCVD system at Peking University, and RF tests were carried out at SLAC National Accelerator Laboratory. The transition temperature is approximately 39.6 K and the RF surface resistance is about 120 μΩmore » at 4 K and 11.4 GHz. Finally, the fabrication processes, surface morphology, DC superconducting properties and RF tests of these large-area MgB 2 films are presented.« less

Fabrication and radio frequency test of large-area MgB 2 films on niobium substrates

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

Ni, Zhimao; Guo, Xin; Welander, Paul B.

Magnesium diboride (MgB 2) is a promising candidate material for superconducting radio frequency (RF) cavities because of its higher transition temperature and critical field compared with niobium. To meet the demand of RF test devices, the fabrication of large-area MgB 2 films on metal substrates is needed. Here, in this work, high quality MgB 2 films with 50 mm diameter were fabricated on niobium by using an improved HPCVD system at Peking University, and RF tests were carried out at SLAC National Accelerator Laboratory. The transition temperature is approximately 39.6 K and the RF surface resistance is about 120 μΩmore » at 4 K and 11.4 GHz. Finally, the fabrication processes, surface morphology, DC superconducting properties and RF tests of these large-area MgB 2 films are presented.« less

Bayesian Maximum Entropy space/time estimation of surface water chloride in Maryland using river distances.

PubMed

Jat, Prahlad; Serre, Marc L

2016-12-01

Widespread contamination of surface water chloride is an emerging environmental concern. Consequently accurate and cost-effective methods are needed to estimate chloride along all river miles of potentially contaminated watersheds. Here we introduce a Bayesian Maximum Entropy (BME) space/time geostatistical estimation framework that uses river distances, and we compare it with Euclidean BME to estimate surface water chloride from 2005 to 2014 in the Gunpowder-Patapsco, Severn, and Patuxent subbasins in Maryland. River BME improves the cross-validation R 2 by 23.67% over Euclidean BME, and river BME maps are significantly different than Euclidean BME maps, indicating that it is important to use river BME maps to assess water quality impairment. The river BME maps of chloride concentration show wide contamination throughout Baltimore and Columbia-Ellicott cities, the disappearance of a clean buffer separating these two large urban areas, and the emergence of multiple localized pockets of contamination in surrounding areas. The number of impaired river miles increased by 0.55% per year in 2005-2009 and by 1.23% per year in 2011-2014, corresponding to a marked acceleration of the rate of impairment. Our results support the need for control measures and increased monitoring of unassessed river miles. Copyright © 2016. Published by Elsevier Ltd.

Daily trends and source apportionment of ultrafine particulate mass (PM0.1) over an annual cycle in a typical California city.

PubMed

Kuwayama, Toshihiro; Ruehl, Chris R; Kleeman, Michael J

2013-12-17

Toxicology studies indicate that inhalation of ultrafine particles (Dp < 0.1 μm) causes adverse health effects, presumably due to their large surface area-to-volume ratio that can drive heterogeneous reactions. Epidemiological associations between ultrafine particles and health effects, however, have been difficult to identify due to the lack of appropriate long-term monitoring and exposure data. The majority of the existing ultrafine particle epidemiology studies are based on exposure to particle number, although an independent analysis suggests that ultrafine particle mass (PM0.1) correlates better with particle surface area. More information is needed to characterize PM0.1 exposure to fully evaluate the health effects of ultrafine particles using epidemiology. The present study summarizes 1 year of daily PM0.1 chemistry and source apportionment at Sacramento, CA, USA. Positive matrix factorization (PMF) was used to resolve PM0.1 source contributions from old-technology diesel engines, residential wood burning, rail, regional traffic, and brake wear/road dust. Diesel PM0.1 and total PM0.1 concentrations were reduced by 97 and 26%, respectively, as a result of the adoption of cleaner diesel technology. The strong linear correlation between PM0.1 and particle surface area in central California suggests that the adoption of clean diesel engines reduced particle surface area by similar amounts. PM0.1 sulfate reduction occurred as a result of reduced primary particle surface area available for sulfate condensation. The current study demonstrates the capability of measuring PM0.1 source contributions over a 12 month period and identifies the extended benefits of emissions reduction efforts for diesel engines on ambient concentrations of primary and secondary PM0.1.

Prototype Global Burnt Area Algorithm Using a Multi-sensor Approach

NASA Astrophysics Data System (ADS)

López Saldaña, G.; Pereira, J.; Aires, F.

2013-05-01

One of the main limitations of products derived from remotely-sensed data is the length of the data records available for climate studies. The Advanced Very High Resolution Radiometer (AVHRR) long-term data record (LTDR) comprises a daily global atmospherically-corrected surface reflectance dataset at 0.05Deg spatial resolution and is available for the 1981-1999 time period. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument has been on orbit in the Terra platform since late 1999 and in Aqua since mid 2002; surface reflectance products, MYD09CMG and MOD09CMG, are available at 0.05Deg spatial resolution. Fire is strong cause of land surface change and emissions of greenhouse gases around the globe. A global long-term identification of areas affected by fire is needed to analyze trends and fire-clime relationships. A burnt area algorithm can be seen as a change point detection problem where there is an abrupt change in the surface reflectance due to the biomass burning. Using the AVHRR-LTDR and the aforementioned MODIS products, a time series of bidirectional reflectance distribution function (BRDF) corrected surface reflectance was generated using the daily observations and constraining the BRDF model inversion using a climatology of BRDF parameters derived from 12 years of MODIS data. The identification of the burnt area was performed using a t-test in the pre- and post-fire reflectance values and a change point detection algorithm, then spectral constraints were applied to flag changes caused by natural land processes like vegetation seasonality or flooding. Additional temporal constraints are applied focusing in the persistence of the affected areas. Initial results for years 1998 to 2002, show spatio-temporal coherence but further analysis is required and a formal rigorous validation will be applied using burn scars identified from high-resolution datasets.

High surface area aerogels for energy storage and efficiency

NASA Astrophysics Data System (ADS)

Maloney, Ryan Patrick

The dissertation is divided into two main chapters, each focused on a different application for aerogel. The first chapter concerns the development of silica aerogel for thermal insulation. It begins with initial characterization of a silica aerogel insulation for a next-generation Advanced Radioisotope Stirling Generator for space vehicles. While the aerogel as made performs well, it is apparent that further improvements in mechanical strength and durability are necessary. The chapter then continues with the exploration of chlorotrimethysilane surface modification, which somewhat surprisingly provides a drastic increase in mechanical properties, allowing the inherently brittle silica network to deform plastically to >80% strain. It is hypothesized that the hydrophobic surface groups reduce capillary forces during drying, lowering the number of microcracks that may form and weaken the gel. This surface modification scheme is then implemented in a fiber-reinforced, opacified aerogel insulation for a prototypical thermoelectric generator for automotive waste heat recovery. This is the first known report of aerogel insulation for thermoelectrics. The aerogel insulation is able to increase the efficiency of the thermoelectric generator by 40% compared with commercial high-temperature insulating wool. Unfortunately, the supercritical drying process adds significant cost to the aerogel insulation, limiting its commercial viability. The chapter then culminates in the development and characterization of an Ambiently Dried Aerogel Insulation (ADAI) that eliminates the need for expensive supercritical drying. It is believed that this report represents the first aerogel insulation that can be dried without undergoing a large volume change before "springing back" to near its original volume, which allows it to be cast into place into complex geometries and around rigid inclusions. This reduces a large barrier to the commercial viability of aerogel insulation. The advantages of ADAI are demonstrated in a third-generation prototypical thermoelectric generator for automotive waste heat recovery. The second chapter then details two different aerogel-based materials for electrochemical energy storage. It begins with lithium titanate aerogel, which takes advantage of the high surface area of the aerogel morphology to display a batt-cap behavior. This should allow the lithium titanate aerogel to perform at higher rates than would normally be expected for the bulk oxide material. Additionally, the flexibility of the sol-gel process is demonstrated through the incorporation of electrically conductive high-surface area exfoliated graphite nanoplatelets in the oxide. The last section describes the characterization of a LiMn2O 4 spinel coated carbon nanofoam in a non-aqueous electrolyte. The short diffusion path, high surface area and intimately wired architecture of the nanofoam allows the oxide to retain its capacity at significantly higher rates when compared with literature values for the bulk oxide. Additionally, the nanometric length scale improves cycle life, and the high surface area dramatically increases the insertion capacity by providing a higher concentration of surface defects. Taken together, it is clear that aerogels are an extremely attractive class of material for applications pertaining to energy and efficiency, and further research in this area will provide valuable solutions for pressing societal needs. (Abstract shortened by UMI.).

A scheme for computing surface layer turbulent fluxes from mean flow surface observations

NASA Technical Reports Server (NTRS)

Hoffert, M. I.; Storch, J.

1978-01-01

A physical model and computational scheme are developed for generating turbulent surface stress, sensible heat flux and humidity flux from mean velocity, temperature and humidity at some fixed height in the atmospheric surface layer, where conditions at this reference level are presumed known from observations or the evolving state of a numerical atmospheric circulation model. The method is based on coupling the Monin-Obukov surface layer similarity profiles which include buoyant stability effects on mean velocity, temperature and humidity to a force-restore formulation for the evolution of surface soil temperature to yield the local values of shear stress, heat flux and surface temperature. A self-contained formulation is presented including parameterizations for solar and infrared radiant fluxes at the surface. Additional parameters needed to implement the scheme are the thermal heat capacity of the soil per unit surface area, surface aerodynamic roughness, latitude, solar declination, surface albedo, surface emissivity and atmospheric transmissivity to solar radiation.

Effectiveness of a Coral-Derived Surfacing Material for Reducing Sediment Production on Unpaved Roads, Schoffield Barracks, Oahu, Hawaii

NASA Astrophysics Data System (ADS)

Ziegler, Alan D.; Sutherland, Ross A.

2006-01-01

This study evaluated the effectiveness of two application rates of a coral-derived surfacing material for both traffic and nontraffic road conditions using simulated rainfall (110-120 mm h-1 for 30-90 min) on 0.75-m (wide) × 5.0-m (long) plots of similar slope (roughly 0.1 m m-1). The coral is a locally available material that has been applied to unpaved roads surfaces on Schoffield Barracks, Oahu, Hawaii (USA), where this experiment was conducted. The simulations show that compared with a bare control plot, the coral-based surface application rates of 80 and 160 kg m-2 (equivalent to only 10- and 20-mm thicknesses) reduced road sediment production by 75% and 95%, respectively, for nontraffic conditions. However, after two passes of the research vehicle during wet conditions, sediment production rates for the two coral treatments were not significantly different from those on the bare road plots. The overall effectiveness of the coral-derived surfacing material is unsatisfactory, primarily because the on-road surface thickness associated with the application rates tested was too small. These rates were selected to bracket those applied to training roads in the study area. Furthermore, the composition of the coral-based material does not facilitate the development of a sealed, erosion-resistant surface. When applied at the low rates tested, the coral material breaks down under normal traffic conditions, thereby losing its ability to counter shearing forces exerted by overland flow on long hillslopes where erosion measures are most needed. These simulations, combined with observations on roads in the study area, indicate that this material is not an appropriate road surfacing material for the site—at least for the low application rates examined. These results are preliminary; extended testing of higher applications rates at the hillslope scale under natural climate and traffic conditions is needed to better judge the effectiveness of this material over time.

Effectiveness of a coral-derived surfacing material for reducing sediment production on unpaved roads, Schoffield barracks, Oahu, Hawaii.

PubMed

Ziegler, Alan D; Sutherland, Ross A

2006-01-01

This study evaluated the effectiveness of two application rates of a coral-derived surfacing material for both traffic and nontraffic road conditions using simulated rainfall (110-120 mm h(-1) for 30-90 min) on 0.75-m (wide) x 5.0-m (long) plots of similar slope (roughly 0.1 m m(-1)). The coral is a locally available material that has been applied to unpaved roads surfaces on Schoffield Barracks, Oahu, Hawaii (USA), where this experiment was conducted. The simulations show that compared with a bare control plot, the coral-based surface application rates of 80 and 160 kg m(-2) (equivalent to only 10- and 20-mm thicknesses) reduced road sediment production by 75% and 95%, respectively, for nontraffic conditions. However, after two passes of the research vehicle during wet conditions, sediment production rates for the two coral treatments were not significantly different from those on the bare road plots. The overall effectiveness of the coral-derived surfacing material is unsatisfactory, primarily because the on-road surface thickness associated with the application rates tested was too small. These rates were selected to bracket those applied to training roads in the study area. Furthermore, the composition of the coral-based material does not facilitate the development of a sealed, erosion-resistant surface. When applied at the low rates tested, the coral material breaks down under normal traffic conditions, thereby losing its ability to counter shearing forces exerted by overland flow on long hillslopes where erosion measures are most needed. These simulations, combined with observations on roads in the study area, indicate that this material is not an appropriate road surfacing material for the site-at least for the low application rates examined. These results are preliminary; extended testing of higher applications rates at the hillslope scale under natural climate and traffic conditions is needed to better judge the effectiveness of this material over time.

Microbial Contamination on Touch Surfaces in Sick- and Well-Child Waiting Rooms in Pediatric Outpatient Facilities.

PubMed

Gudakova, Irina; Kim, JinYoung; Meredith, Jennifer F; Webb, Ginny

2017-12-01

Healthcare-associated infections are a significant public health burden resulting in approximately 1.7 million infections each year. Much work is done to study the contributing factors in inpatient settings; however, little has been done to study outpatient facilities and their roles in healthcare-associated infections. While many pediatric outpatient offices utilize separated waiting areas for sick and well children to decrease the spread of disease, research has not been done to determine whether this practice is of benefit. In this study, we aimed to determine whether there is a difference in microbial burden between sick- and well-child waiting areas and to identify surfaces with the highest levels of contamination. Touch surfaces in waiting rooms were swabbed and surveyed for total microbial growth, staphylococcal growth and Gram-negative enteric bacterial growth. Selected bacteria were identified to screen for pathogenic organisms. Surfaces sampled included seats, tables, children's tables, children's seats, magazines and books. We found seats, children's seats and children's books to have the highest microbial burden. No conclusions can be made on the differences in microbial contamination in sick- and well-child waiting areas because of high variation. Streptococcus pyogenes was isolated as were several opportunistic pathogens. This study suggests the need for better cleaning practices by pediatric outpatient facilities, to include the disinfection of additional surfaces as well as more frequent and thorough cleaning.

How Well Can We Estimate Areal-Averaged Spectral Surface Albedo from Ground-Based Transmission in an Atlantic Coastal Area?

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

Kassianov, Evgueni I.; Barnard, James C.; Flynn, Connor J.

Areal-averaged albedos are particularly difficult to measure in coastal regions, because the surface is not homogenous, consisting of a sharp demarcation between land and water. With this difficulty in mind, we evaluate a simple retrieval of areal-averaged surface albedo using ground-based measurements of atmospheric transmission alone under fully overcast conditions. To illustrate the performance of our retrieval, we find the areal-averaged albedo using measurements from the Multi-Filter Rotating Shadowband Radiometer (MFRSR) at five wavelengths (415, 500, 615, 673, and 870 nm). These MFRSR data are collected at a coastal site in Graciosa Island, Azores supported by the U.S. Department ofmore » Energy’s (DOE’s) Atmospheric Radiation Measurement (ARM) Program. The areal-averaged albedos obtained from the MFRSR are compared with collocated and coincident Moderate Resolution Imaging Spectroradiometer (MODIS) white-sky albedo at four nominal wavelengths (470, 560, 670 and 860 nm). These comparisons are made during a 19-month period (June 2009 - December 2010). We also calculate composite-based spectral values of surface albedo by a weighted-average approach using estimated fractions of major surface types observed in an area surrounding this coastal site. Taken as a whole, these three methods of finding albedo show spectral and temporal similarities, and suggest that our simple, transmission-based technique holds promise, but with estimated errors of about ±0.03. Additional work is needed to reduce this uncertainty in areas with inhomogeneous surfaces.« less

Water reservoir characteristics derivation from pubicly available global elevation data

NASA Astrophysics Data System (ADS)

Van De Giesen, N.; van Bemmelen, C.; Mann, M.; de Ridder, M.; Gupta, V.; Rutten, M.

2017-12-01

In order to assess human impact on the global hydrological cycle, it is imperative to characterize all major man made reservoirs. One important characteristic is the relationship between the surface area of a reservoir and its stored water volume. Surface areas can readily be determined through optical and radar satellite remote sensing. Once the relationship between the surface area of a reservoir and its stored water volume is known, one can determine the stored volumes over time using remotely sensed surface areas. It has been known for some time that this relationship between surface and stored volume shows a very high level of regional consistency [1]. This implies that if one knows this relationship in a certain region, one can predict the same for any nearby reservoir. We have tried to exploit this fact by examining whether one can build virtual dams in the neighborhood of an existing dam to determine the general relationship between surface area and stored volume. We examined twelve reservoirs around the world and found, generally, very good results. Especially in geomorphologically homogeneous areas, the relationships could reliable be extrapolated over space. Even in very heterogeneous areas, the final results were acceptable and much better than generic relationships used so far. Finally, we have examined to what extent it is possible to select virtual dam sites automatically. The first results for this are promising and show that it may be possible to characterize most major dams in the world according to this approach. It is likely that there will be the need for human detection for a reasonable percentage. For these relatively rare case, some human micro-tasking may be the way forward. It is expected, however, that >90% of the worldś dams can be characterized automatically [1] Liebe, J., N. Van De Giesen, and Marc Andreini. "Estimation of small reservoir storage capacities in a semi-arid environment: A case study in the Upper East Region of Ghana." Physics and Chemistry of the Earth, Parts A/B/C 30, no. 6 (2005): 448-454.

Diagnostic and model dependent uncertainty of simulated Tibetan permafrost area

NASA Astrophysics Data System (ADS)

Wang, W.; Rinke, A.; Moore, J. C.; Cui, X.; Ji, D.; Li, Q.; Zhang, N.; Wang, C.; Zhang, S.; Lawrence, D. M.; McGuire, A. D.; Zhang, W.; Delire, C.; Koven, C.; Saito, K.; MacDougall, A.; Burke, E.; Decharme, B.

2015-03-01

We perform a land surface model intercomparison to investigate how the simulation of permafrost area on the Tibetan Plateau (TP) varies between 6 modern stand-alone land surface models (CLM4.5, CoLM, ISBA, JULES, LPJ-GUESS, UVic). We also examine the variability in simulated permafrost area and distribution introduced by 5 different methods of diagnosing permafrost (from modeled monthly ground temperature, mean annual ground and air temperatures, air and surface frost indexes). There is good agreement (99-135 x 104 km2) between the two diagnostic methods based on air temperature which are also consistent with the best current observation-based estimate of actual permafrost area (101 x 104 km2). However the uncertainty (1-128 x 104 km2) using the three methods that require simulation of ground temperature is much greater. Moreover simulated permafrost distribution on TP is generally only fair to poor for these three methods (diagnosis of permafrost from monthly, and mean annual ground temperature, and surface frost index), while permafrost distribution using air temperature based methods is generally good. Model evaluation at field sites highlights specific problems in process simulations likely related to soil texture specification and snow cover. Models are particularly poor at simulating permafrost distribution using definition that soil temperature remains at or below 0°C for 24 consecutive months, which requires reliable simulation of both mean annual ground temperatures and seasonal cycle, and hence is relatively demanding. Although models can produce better permafrost maps using mean annual ground temperature and surface frost index, analysis of simulated soil temperature profiles reveals substantial biases. The current generation of land surface models need to reduce biases in simulated soil temperature profiles before reliable contemporary permafrost maps and predictions of changes in permafrost distribution can be made for the Tibetan Plateau.

Proceedings of the Tri-Service Conference on Corrosion Held in Atlantic City, New Jersey on 17-19 October 1989

DTIC Science & Technology

1989-10-19

installation. 4. Corrosion inhibiting compounds need to be applied in the final assealbly of models to all corrosion prone areas of the structure, e.g...Figure 12 shows an example of poor surface treatment of a previously repaired stringer area. Application of a corrosion inhibiting compound may have... compounds and a good corrosion control maintenance program. REFERENCE U. G. Goranson and M. Miller, "Aging Fleet - Aging Fleet Evaluation Program

Climatic and lake temperature data for Wetland P1, Cottonwood Lake Area, Stutsman County, North Dakota, 1982-87

USGS Publications Warehouse

Parkhurst, Renee S.; Sturrock, A.M.; Rosenberry, D.O.; Winter, T.C.

1995-01-01

Research on the hydrology of Wetland P1 and the Cottonwood Lake Area includes the study of evaporation. Presented here in a graphical format are those data collected during the open-water seasons of 1982-87 that were needed for energy- budget and mass-transfer evaporation studies. The data include air temperatures, water surface and lake-bottom temperatures, windspeed, radiation, humidity, and precipitation. Data were collected at a raft station and two land stations.

Recent advances in engineering topography mediated antibacterial surfaces

PubMed Central

Hasan, Jafar

2015-01-01

The tendency of bacterial cells to adhere and colonize a material surface leading to biofilm formation is a fundamental challenge underlying many different applications including microbial infections associated with biomedical devices and products. Although, bacterial attachment to surfaces has been extensively studied in the past, the effect of surface topography on bacteria–material interactions has received little attention until more recently. We review the recent progress in surface topography based approaches for engineering antibacterial surfaces. Biomimicry of antibacterial surfaces in nature is a popular strategy. Whereas earlier endeavors in the field aimed at minimizing cell attachment, more recent efforts have focused on developing bactericidal surfaces. However, not all such topography mediated bactericidal surfaces are necessarily cytocompatible thus underscoring the need for continued efforts for research in this area for developing antibacterial and yet cytocompatible surfaces for use in implantable biomedical applications. This mini-review provides a brief overview of the current strategies and challenges in the emerging field of topography mediated antibacterial surfaces. PMID:26372264

Recent advances in engineering topography mediated antibacterial surfaces

NASA Astrophysics Data System (ADS)

Hasan, Jafar; Chatterjee, Kaushik

2015-09-01

The tendency of bacterial cells to adhere and colonize a material surface leading to biofilm formation is a fundamental challenge underlying many different applications including microbial infections associated with biomedical devices and products. Although, bacterial attachment to surfaces has been extensively studied in the past, the effect of surface topography on bacteria-material interactions has received little attention until more recently. We review the recent progress in surface topography based approaches for engineering antibacterial surfaces. Biomimicry of antibacterial surfaces in nature is a popular strategy. Whereas earlier endeavors in the field aimed at minimizing cell attachment, more recent efforts have focused on developing bactericidal surfaces. However, not all such topography mediated bactericidal surfaces are necessarily cytocompatible thus underscoring the need for continued efforts for research in this area for developing antibacterial and yet cytocompatible surfaces for use in implantable biomedical applications. This mini-review provides a brief overview of the current strategies and challenges in the emerging field of topography mediated antibacterial surfaces.

Assessment of Different Biofilter Media Particle Sizes for Ammonia Removal Optimization

USDA-ARS?s Scientific Manuscript database

The main objective of this study is to determine a range of particle sizes that provides low resistance to the air flow but also sufficient surface area for microbial attachment, which is needed for higher biofiltration efficiency. This will be done by assessing ammonia removal and pressure drop in ...

Predicting fire severity using surface fuels and moisture

Treesearch

Pamela G. Sikkink; Robert E. Keane

2012-01-01

Fire severity classifications have been used extensively in fire management over the last 30 years to describe specific environmental or ecological impacts of fire on fuels, vegetation, wildlife, and soils in recently burned areas. New fire severity classifications need to be more objective, predictive, and ultimately more useful to fire management and planning. Our...

10 CFR 60.121 - Requirements for ownership and control of interests in land.

Code of Federal Regulations, 2013 CFR

2013-01-01

... postclosure controlled area. DOE shall exercise any jurisdiction and control over surface and subsurface... interests, servitudes, or withdrawals from location or patent under the general mining laws. (c) Water rights. (1) DOE shall also have obtained such water rights as may be needed to accomplish the purpose of...

10 CFR 60.121 - Requirements for ownership and control of interests in land.

Code of Federal Regulations, 2014 CFR

2014-01-01

... postclosure controlled area. DOE shall exercise any jurisdiction and control over surface and subsurface... interests, servitudes, or withdrawals from location or patent under the general mining laws. (c) Water rights. (1) DOE shall also have obtained such water rights as may be needed to accomplish the purpose of...

10 CFR 60.121 - Requirements for ownership and control of interests in land.

Code of Federal Regulations, 2012 CFR

2012-01-01

... postclosure controlled area. DOE shall exercise any jurisdiction and control over surface and subsurface... interests, servitudes, or withdrawals from location or patent under the general mining laws. (c) Water rights. (1) DOE shall also have obtained such water rights as may be needed to accomplish the purpose of...

Impact of macropores and gravel outcrops on phosphorus leaching at the plot scale in silt loam soils

USDA-ARS?s Scientific Manuscript database

In response to increased nutrient loads in surface waters, scientists and engineers need to identify critical nutrient source areas and transport mechanisms within a catchment to protect beneficial uses of aquatic systems in a cost effective manner. It was hypothesized that hydrologic heterogeneitie...

Marine biosurfaces research program

NASA Astrophysics Data System (ADS)

The Office of Naval Research (ONR) of the U.S. Navy is starting a basic research program to address the initial events that control colonization of surfaces by organisms in marine environments. The program “arises from the Navy's need to understand and ultimately control biofouling and biocorrosion in marine environments,” according to a Navy announcement.The program, “Biological Processes Controlling Surface Modification in the Marine Environment,” will emphasize the application of in situ techniques and modern molecular biological, biochemical, and biophysical approaches; it will also encourage the development of interdisciplinary projects. Specific areas of interest include sensing and response to environmental surface (physiology/physical chemistry), factors controlling movement to and retention at surfaces (behavior/hydrodynamics), genetic regulation of attachment (molecular genetics), and mechanisms of attachment (biochemistry/surface chemistry).

Titan probe technology assessment and technology development plan study

NASA Technical Reports Server (NTRS)

Castro, A. J.

1980-01-01

The need for technology advances to accomplish the Titan probe mission was determined by defining mission conditions and requirements and evaluating the technology impact on the baseline probe configuration. Mission characteristics found to be technology drivers include (1) ten years dormant life in space vacuum; (2) unknown surface conditions, various sample materials, and a surface temperature; and (3) mission constraints of the Saturn Orbiter Dual Probe mission regarding weight allocation. The following areas were identified for further development: surface sample acquisition system; battery powered system; nonmetallic materials; magnetic bubble memory devices, and the landing system. Preentry science, reliability, and weight reduction and redundancy must also be considered.

Study of role of meniscus and viscous forces during liquid-mediated contacts separation

NASA Astrophysics Data System (ADS)

Dhital, Prabin

Menisci may form between two solid surfaces with the presence of an ultra-thin liquid film. When the separation operation is needed, meniscus and viscous forces contribute to an adhesion leading stiction, high friction, possibly high wear and potential failure of the contact systems, for instance microdevices, magnetic head disks and diesel fuel injectors. The situation may become more pronounced when the contacting surfaces are ultra-smooth and the normal load is small. Various design parameters, such as contact angle, initial separation height, surface tension and liquid viscosity, have been investigated during liquid-mediated contact separation. However, how the involved forces will change roles for various liquid is of interest and is necessary to be studied. In this study, meniscus and viscous forces due to water and liquid lubricants during separation of two flat surfaces are studied. Previously established mathematical model for meniscus and viscous forces during flat on flat contact separation is simulated. The effect of meniscus and viscous force on critical meniscus area at which those forces change role is studied with different liquid properties for flat on flat contact surfaces. The roles of the involved forces at various meniscus areas are analyzed. Experiments are done in concerns to studying the effect of surface roughness on contact angle. The impact of liquid properties, initial separation heights and contact angle on critical meniscus area for different liquid properties are analyzed. The study provides a fundamental understanding of the forces of the separation process and its value for the design of interfaces. The effect of surface roughness and liquid properties on contact angle are studied.

Evaluation of methods for characterizing surface topography of models for high Reynolds number wind-tunnels

NASA Technical Reports Server (NTRS)

Teague, E. C.; Vorburger, T. V.; Scire, F. E.; Baker, S. M.; Jensen, S. W.; Gloss, B. B.; Trahan, C.

1982-01-01

Current work by the National Bureau of Standards at the NASA National Transonic Facility (NTF) to evaluate the performance of stylus instruments for determining the topography of models under investigation is described along with instrumentation for characterization of the surface microtopography. Potential areas of surface effects are reviewed, and the need for finer surfaced models for the NTF high Reynolds number flows is stressed. Current stylus instruments have a radii as large as 25 microns, and three models with surface finishes of 4-6, 8-10, and 12-15 micro-in. rms surface finishes were fabricated for tests with a stylus with a tip radius of 1 micron and a 50 mg force. Work involving three-dimensional stylus profilometry is discussed in terms of stylus displacement being converted to digital signals, and the design of a light scattering instrument capable of measuring the surface finish on curved objects is presented.

Nano-objects as biomaterials: immense opportunities, significant challenges and the important use of surface analytical methods

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

Baer, Donald R.; Shutthanandan, Vaithiyalingam

Nano-sized objects are increasingly important as biomaterials and their surfaces play critical roles in determining their beneficial or deleterious behaviors in biological systems. Important characteristics of nanomaterials that impact their application in many areas are described with a strong focus on the importance of particle surfaces and surface characterization. Understanding aspects of the inherent nature of nano-objects and the important role that surfaces play in these applications is a universal need for any research or product development using such materials in biological applications. The role of surface analysis methods in collecting critical information about the nature of particle surfaces andmore » physicochemical properties of nano-objects is described along with the importance of including sample history and analysis results in a record of provenance information regarding specific batches of nano-objects.« less

Ground-water recharge in humid areas of the United States: A summary of Ground-Water Resources Program studies, 2003-2006

USGS Publications Warehouse

Delin, Geoffrey N.; Risser, Dennis W.

2007-01-01

Increased demands on water resources by a growing population and recent droughts have raised awareness about the adequacy of ground-water resources in humid areas of the United States. The spatial and temporal variability of ground-water recharge are key factors that need to be quantified to determine the sustainability of ground-water resources. Ground-water recharge is defined herein as the entry into the saturated zone of water made available at the water-table surface, together with the associated flow away from the water table within the saturated zone (Freeze and Cherry, 1979). In response to the need for better estimates of ground-water recharge, the Ground-Water Resources Program (GWRP) of the U.S. Geological Survey (USGS) began an initiative in 2003 to estimate ground-water recharge rates in the relatively humid areas of the United States.

Bird Richness and Abundance in Response to Urban Form in a Latin American City: Valdivia, Chile as a Case Study.

PubMed

Silva, Carmen Paz; García, Cristóbal E; Estay, Sergio A; Barbosa, Olga

2015-01-01

There is mounting evidence that urban areas influence biodiversity. Generalizations however require that multiple urban areas on multiple continents be examined. Here we evaluated the role of urban areas on avian diversity for a South American city, allowing us to examine the effects of urban features common worldwide, using the city of Valdivia, Chile as case study. We assessed the number of birds and their relative abundance in 152 grid cells of equal size (250 m2) distributed across the city. We estimated nine independent variables: land cover diversity (DC), building density (BD), impervious surface (IS),municipal green space (MG),non-municipal green space (NG), domestic garden space (DG), distance to the periphery (DP), social welfare index (SW), and vegetation diversity (RV). Impervious surface represent 41.8% of the study area, while municipal green, non-municipal green and domestic garden represent 11.6%, 23.6% and 16% of the non- man made surface. Exotic vegetation species represent 74.6% of the total species identified across the city. We found 32 bird species, all native with the exception of House Sparrow and Rock Pigeon. The most common species were House Sparrow and Chilean Swallow. Total bird richness responds negatively to IS and MG, while native bird richness responds positively to NG and negatively to BD, IS DG and, RV. Total abundance increase in areas with higher values of DC and BD, and decrease in areas of higher values of IS, SW and VR. Native bird abundance responds positively to NG and negatively to BD, IS MG, DG and RV. Our results suggest that not all the general patterns described in previous studies, conducted mainly in the USA, Europe, and Australia, can be applied to Latin American cities, having important implications for urban planning. Conservation efforts should focus on non-municipal areas, which harbor higher bird diversity, while municipal green areas need to be improved to include elements that can enhance habitat quality for birds and other species. These findings are relevant for urban planning in where both types of green space need to be considered, especially non-municipal green areas, which includes wetlands, today critically threatened by urban development.

Bird Richness and Abundance in Response to Urban Form in a Latin American City: Valdivia, Chile as a Case Study

PubMed Central

García, Cristóbal E.; Estay, Sergio A.

2015-01-01

There is mounting evidence that urban areas influence biodiversity. Generalizations however require that multiple urban areas on multiple continents be examined. Here we evaluated the role of urban areas on avian diversity for a South American city, allowing us to examine the effects of urban features common worldwide, using the city of Valdivia, Chile as case study. We assessed the number of birds and their relative abundance in 152 grid cells of equal size (250 m2) distributed across the city. We estimated nine independent variables: land cover diversity (DC), building density (BD), impervious surface (IS),municipal green space (MG),non-municipal green space (NG), domestic garden space (DG), distance to the periphery (DP), social welfare index (SW), and vegetation diversity (RV). Impervious surface represent 41.8% of the study area, while municipal green, non-municipal green and domestic garden represent 11.6%, 23.6% and 16% of the non- man made surface. Exotic vegetation species represent 74.6% of the total species identified across the city. We found 32 bird species, all native with the exception of House Sparrow and Rock Pigeon. The most common species were House Sparrow and Chilean Swallow. Total bird richness responds negatively to IS and MG, while native bird richness responds positively to NG and negatively to BD, IS DG and, RV. Total abundance increase in areas with higher values of DC and BD, and decrease in areas of higher values of IS, SW and VR. Native bird abundance responds positively to NG and negatively to BD, IS MG, DG and RV. Our results suggest that not all the general patterns described in previous studies, conducted mainly in the USA, Europe, and Australia, can be applied to Latin American cities, having important implications for urban planning. Conservation efforts should focus on non-municipal areas, which harbor higher bird diversity, while municipal green areas need to be improved to include elements that can enhance habitat quality for birds and other species. These findings are relevant for urban planning in where both types of green space need to be considered, especially non-municipal green areas, which includes wetlands, today critically threatened by urban development. PMID:26422260

Quantifying the Significance of Heterogeneity in Supraglacial Reflectance Characteristics for Meltwater Production in Southwest Greenland

NASA Astrophysics Data System (ADS)

Irvine-Fynn, T. D.; Bunting, P.; Cook, J.; Hardy, A. J.; Hodson, A. J.; Holt, T.; Hubbard, A.; Naegeli, K.; Nilsson, J.; Ryan, J.; Roberts, O.; Tedstone, A.; Tranter, M.; Williamson, C.

2017-12-01

The seasonal melt on the southwestern margin of the Greenland Ice Sheet has been enhanced due to processes affecting the ablation area's ice surface reflectance (albedo). Recent trends in surface reflectance in the region suggest a decline potentially linked to an albedo-feedback associated with regional climate warming, emergence of organic and mineral particulates, and expansion of melt area. However, the heterogeneity of reflectance over bare ice areas in space and time has remained relatively poorly characterised. Numerous surface mass balance models utilise albedo products derived from remote sensing platforms with coarse scale resolution. Such products provide reasonable albedo estimates, but quantification of local variability in reflectance remains lacking. Consequently, there is a need to better define the distribution and representativeness of ice surface reflectance at and below the scale of satellite sensor pixel footprints to facilitate examination of albedo parameterisations. Here, we present reflectance data repeatedly collected in SW Greenland during the 2016 summer melt season over a 0.0625 km2 area proximate to the IMAU K-transect site S6 (67°04.5'N, 49°21.0'W). The Moderate Resolution Imaging Spectrometer (MODIS) albedo product MOD10A1(c6) for the study site was compared to reflectance data from Sentinel-2, centimetre resolution calibrated 12Mpix optical imagery collected using an Unmanned Aerial Vehicle (UAV) flown at a height of 70 m above the ice surface, and ground-based reflectance survey data acquired using a StellarNet Red-Dwarf/Blue-Wave visible-infrared dual system (250-1700nm) at 30 sites distributed over the area of interest. Our data highlight variability in the spatial distribution of ice surface reflectance characteristics over time. Specifically, data demonstrate marked changes in the distribution of reflectance values, despite maintaining a broadly equitable mean and median during July and August. The influence of the varied surface heterogeneity is explored further using surface energy balance modelling to quantify the impact of such changes on melt production. The findings determine the necessity to account for local variability underlying the pixel-averaged values retrieved from remote sensing platforms such as MODIS.

Prototype global burnt area algorithm using the AVHRR-LTDR time series

NASA Astrophysics Data System (ADS)

López-Saldaña, Gerardo; Pereira, José Miguel; Aires, Filipe

2013-04-01

One of the main limitations of products derived from remotely-sensed data is the length of the data records available for climate studies. The Advanced Very High Resolution Radiometer (AVHRR) long-term data record (LTDR) comprises a daily global atmospherically-corrected surface reflectance dataset at 0.05° spatial resolution and is available for the 1981-1999 time period. Fire is strong cause of land surface change and emissions of greenhouse gases around the globe. A global long-term identification of areas affected by fire is needed to analyze trends and fire-clime relationships. A burnt area algorithm can be seen as a change point detection problem where there is an abrupt change in the surface reflectance due to the biomass burning. Using the AVHRR-LTDR dataset, a time series of bidirectional reflectance distribution function (BRDF) corrected surface reflectance was generated using the daily observations and constraining the BRDF model inversion using a climatology of BRDF parameters derived from 12 years of MODIS data. The identification of the burnt area was performed using a t-test in the pre- and post-fire reflectance values and a change point detection algorithm, then spectral constraints were applied to flag changes caused by natural land processes like vegetation seasonality or flooding. Additional temporal constraints are applied focusing in the persistence of the affected areas. Initial results for year 1998, which was selected because of a positive fire anomaly, show spatio-temporal coherence but further analysis is required and a formal rigorous validation will be applied using burn scars identified from high-resolution datasets.

Graphite fiber brush anodes for increased power production in air-cathode microbial fuel cells.

PubMed

Logan, Bruce; Cheng, Shaoan; Watson, Valerie; Estadt, Garett

2007-05-01

To efficiently generate electricity using bacteria in microbial fuel cells (MFCs), highly conductive noncorrosive materials are needed that have a high specific surface area (surface area per volume) and an open structure to avoid biofouling. Graphite brush anodes, consisting of graphite fibers wound around a conductive, but noncorrosive metal core, were examined for power production in cube (C-MFC) and bottle (B-MFC) air-cathode MFCs. Power production in C-MFCs containing brush electrodes at 9600 m2/m3 reactor volume reached a maximum power density of 2400 mW/m2 (normalized to the cathode projected surface area), or 73 W/m3 based on liquid volume, with a maximum Coulombic efficiency (CE) of 60%. This power density, normalized by cathode projected area, is the highest value yet achieved by an air-cathode system. The increased power resulted from a reduction in internal resistance from 31 to 8 Q. Brush electrodes (4200 m2/m3) were also tested in B-MFCs, consisting of a laboratory media bottle modified to have a single side arm with a cathode clamped to its end. B-MFCs inoculated with wastewater produced up to 1430 mW/m2 (2.3 W/m3, CE = 23%) with brush electrodes, versus 600 mW/m2 with a plain carbon paper electrode. These findings show that brush anodes that have high surface areas and a porous structure can produce high power densities, and therefore have qualities that make them ideal for scaling up MFC systems.

In-situ monitoring of flow-permeable surface area of high explosive powder using small sample masses

DOE PAGES

Maiti, Amitesh; Han, Yong; Zaka, Fowzia; ...

2015-02-17

To ensure good performance of high explosive devices over long periods of time, initiating powders need to maintain their specific surface area within allowed margins during the entire duration of deployment. A common diagnostic used in this context is the Fisher sub-sieve surface area (FSSA). Furthermore, commercial permeametry instruments measuring the FSSA requires the utilization of a sample mass equal to the crystal density of the sample material, an amount that is often one or two orders of magnitude larger than the typical masses found in standard detonator applications. Here we develop a customization of the standard device that canmore » utilize just tens of milligram samples, and with simple calibration yield FSSA values at ac curacy levels comparable to the standard apparatus. This necessitated a newly designed sample holder, made from a material of low coefficient of thermal expansion, which is conveniently transferred between an aging chamber and a re-designed permeametry tube. This improves the fidelity of accelerated aging studies by allowing measurement on the same physical sample at various time - instants during the aging process, and by obviating the need for a potentially FSSA-altering powder re-compaction step. We used the customized apparatus to monitor the FSSA evolution of a number of undoped and homolog-doped PETN powder samples that were subjected to artificial aging for several months at elevated temperatures. These results, in conjunction with an Arrhenius-based aging model were used to assess powder-coarsening - rates under long-term storage.« less

Development of Autonomous Magnetometer Rotorcraft For Wide Area Assessment

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

Mark D. McKay; Matthew O. Anderson

2011-08-01

Large areas across the United States and internationally are potentially contaminated with unexploded ordinance (UXO), with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with (1) near 100% coverage and (2) near 100% detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area assessment is a multi-level one, in which medium - altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry. Subsequent to this wide areamore » assessment targeted surface investigations are performed using either towed geophysical sensor arrays or man portable sensors. In order to be an effective tool for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 to 3 meters. These altitude requirements mean that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys, resulting in costs of approximately $100-$150/acre. In addition, due to the low altitude there are substantial risks to pilots and equipment. Surface towed arrays provide highresolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. Thus there is a need for other systems, which can be used for effective data collection. An Unmanned Aerial Vehicle (UAV) magnetometer platform is an obvious alternative. The motivation behind such a system is that it reduces risk to operators, is lower in initial and Operational and Maintenance (O&M) costs (and can thus potentially be applied to smaller sites) and has the potential of being more effective in terms of detection and possibly characterization (through the use of dynamic acquisition, i.e. survey mission in-flight reprioritization).« less

Laser Processed Condensing Heat Exchanger Technology Development

NASA Technical Reports Server (NTRS)

Hansen, Scott; Wright, Sarah; Wallace, Sarah; Hamilton, Tanner; Dennis, Alexander; Zuhlke, Craig; Roth, Nick; Sanders, John

2017-01-01

The reliance on non-permanent coatings in Condensing Heat Exchanger (CHX) designs is a significant technical issue to be solved before long-duration spaceflight can occur. Therefore, high reliability CHXs have been identified by the Evolvable Mars Campaign (EMC) as critical technologies needed to move beyond low earth orbit. The Laser Processed Condensing Heat Exchanger project aims to solve these problems through the use of femtosecond laser processed surfaces, which have unique wetting properties and potentially exhibit anti-microbial growth properties. These surfaces were investigated to identify if they would be suitable candidates for a replacement CHX surface. Among the areas researched in this project include microbial growth testing, siloxane flow testing in which laser processed surfaces were exposed to siloxanes in an air stream, and manufacturability.

Modeling adsorption: Investigating adsorbate and adsorbent properties

NASA Astrophysics Data System (ADS)

Webster, Charles Edwin

1999-12-01

Surface catalyzed reactions play a major role in current chemical production technology. Currently, 90% of all chemicals are produced by heterogeneously catalyzed reactions. Most of these catalyzed reactions involve adsorption, concentrating the substrate(s) (the adsorbate) on the surface of the solid (the adsorbent). Pore volumes, accessible surface areas, and the thermodynamics of adsorption are essential in the understanding of solid surface characteristics fundamental to catalyst and adsorbent screening and selection. Molecular properties such as molecular volumes and projected molecular areas are needed in order to convert moles adsorbed to surface volumes and areas. Generally, these molecular properties have been estimated from bulk properties, but many assumptions are required. As a result, different literature values are employed for these essential molecular properties. Calculated molar volumes and excluded molecular areas are determined and tabulated for a variety of molecules. Molecular dimensions of molecules are important in the understanding of molecular exclusion as well as size and shape selectivity, diffusion, and adsorbent selection. Molecular dimensions can also be used in the determination of the effective catalytic pore size of a catalyst. Adsorption isotherms, on zeolites, (crystalline mineral oxides) and amorphous solids, can be analyzed with the Multiple Equilibrium Analysis (MEA) description of adsorption. The MEA produces equilibrium constants (Ki), capacities (ni), and thermodynamic parameters (enthalpies, ΔHi, and entropies, ΔSi) of adsorption for each process. Pore volumes and accessible surface areas are calculated from the process capacities. Adsorption isotherms can also be predicted for existing and new adsorbate-adsorbent systems with the MEA. The results show that MEA has the potential of becoming a standard characterization method for microporous solids that will lead to an increased understanding of their behavior in gas adsorption and catalysis. These studies are also applicable to environmental cleanup applications, such as waste stream purification and separation procedures as well as decontamination of chemical warfare agents.

Quaternary Geology and Surface Faulting Hazard: Active and Capable Faults in Central Apennines, Italy

NASA Astrophysics Data System (ADS)

Falcucci, E.; Gori, S.

2015-12-01

The 2009 L'Aquila earthquake (Mw 6.1), in central Italy, raised the issue of surface faulting hazard in Italy, since large urban areas were affected by surface displacement along the causative structure, the Paganica fault. Since then, guidelines for microzonation were drew up that take into consideration the problem of surface faulting in Italy, and laying the bases for future regulations about related hazard, similarly to other countries (e.g. USA). More specific guidelines on the management of areas affected by active and capable faults (i.e. able to produce surface faulting) are going to be released by National Department of Civil Protection; these would define zonation of areas affected by active and capable faults, with prescriptions for land use planning. As such, the guidelines arise the problem of the time interval and general operational criteria to asses fault capability for the Italian territory. As for the chronology, the review of the international literature and regulatory allowed Galadini et al. (2012) to propose different time intervals depending on the ongoing tectonic regime - compressive or extensional - which encompass the Quaternary. As for the operational criteria, the detailed analysis of the large amount of works dealing with active faulting in Italy shows that investigations exclusively based on surface morphological features (e.g. fault planes exposition) or on indirect investigations (geophysical data), are not sufficient or even unreliable to define the presence of an active and capable fault; instead, more accurate geological information on the Quaternary space-time evolution of the areas affected by such tectonic structures is needed. A test area for which active and capable faults can be first mapped based on such a classical but still effective methodological approach can be the central Apennines. Reference Galadini F., Falcucci E., Galli P., Giaccio B., Gori S., Messina P., Moro M., Saroli M., Scardia G., Sposato A. (2012). Time intervals to assess active and capable faults for engineering practices in Italy. Eng. Geol., 139/140, 50-65.

Average Cross-Sectional Area of DebriSat Fragments Using Volumetrically Constructed 3D Representations

NASA Technical Reports Server (NTRS)

Scruggs, T.; Moraguez, M.; Patankar, K.; Fitz-Coy, N.; Liou, J.-C.; Sorge, M.; Huynh, T.

2016-01-01

Debris fragments from the hypervelocity impact testing of DebriSat are being collected and characterized for use in updating existing satellite breakup models. One of the key parameters utilized in these models is the ballistic coefficient of the fragment which is directly related to its area-to-mass ratio. However, since the attitude of fragments varies during their orbital lifetime, it is customary to use the average cross-sectional area in the calculation of the area-to-mass ratio. The average cross-sectional area is defined as the average of the projected surface areas perpendicular to the direction of motion and has been shown to be equal to one-fourth of the total surface area of a convex object. Unfortunately, numerous fragments obtained from the DebriSat experiment show significant concavity (i.e., shadowing) and thus we have explored alternate methods for computing the average cross-sectional area of the fragments. An imaging system based on the volumetric reconstruction of a 3D object from multiple 2D photographs of the object was developed for use in determining the size characteristic (i.e., characteristics length) of the DebriSat fragments. For each fragment, the imaging system generates N number of images from varied azimuth and elevation angles and processes them using a space-carving algorithm to construct a 3D point cloud of the fragment. This paper describes two approaches for calculating the average cross-sectional area of debris fragments based on the 3D imager. Approach A utilizes the constructed 3D object to generate equally distributed cross-sectional area projections and then averages them to determine the average cross-sectional area. Approach B utilizes a weighted average of the area of the 2D photographs to directly compute the average cross-sectional area. A comparison of the accuracy and computational needs of each approach is described as well as preliminary results of an analysis to determine the "optimal" number of images needed for the 3D imager to accurately measure the average cross sectional area of objects with known dimensions.

Determination of the Electrochemical Area of Screen-Printed Electrochemical Sensing Platforms.

PubMed

García-Miranda Ferrari, Alejandro; Foster, Christopher W; Kelly, Peter J; Brownson, Dale A C; Banks, Craig E

2018-06-08

Screen-printed electrochemical sensing platforms, due to their scales of economy and high reproducibility, can provide a useful approach to translate laboratory-based electrochemistry into the field. An important factor when utilising screen-printed electrodes (SPEs) is the determination of their real electrochemical surface area, which allows for the benchmarking of these SPEs and is an important parameter in quality control. In this paper, we consider the use of cyclic voltammetry and chronocoulometry to allow for the determination of the real electrochemical area of screen-printed electrochemical sensing platforms, highlighting to experimentalists the various parameters that need to be diligently considered and controlled in order to obtain useful measurements of the real electroactive area.

Sol-gel chemical sensors for surface-enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Lee, Vincent Y.; Farquharson, Stuart; Kwon, Hueong-Chan; Shahriari, Mahmoud R.; Rainey, Petrie M.

1999-02-01

Surface-enhanced Raman spectroscopy (SERS) promises to be one of the most sensitive methods for chemical detection. Unfortunately, the inability of SERS to perform quantitative chemical analysis has slowed its general use in laboratories. This is largely due to the difficulty of manufacturing either active surfaces that yield reproducible enhancements, or surfaces that are capable of reversible chemical adsorption, or both. In an effort to meet this need, we have developed metal-doped sol-gels that provide surface-enhancement of Raman scattering. The porous silica network offers a unique environment for stabilizing SER active metal particles and the high surface area increases the interaction between the analyte and metal particles. This eliminates the need to concentrate the analyte on the surface by evaporating the solvent. The sol-gel is easily coated on a variety of surfaces, such as fiber optics, glass slides, or glass tubing, and can be designed into sample flow systems. Here we present the development of both gold- and silver-doped sol-gels, which have been used to coat the inside walls of glass sample vials for SERS applications. The performance of the metal-doped sol-gels was evaluated using p-aminobenzoic acid, to establish enhancement factors, detection limits, dynamic response range, reversibility, reproducibility, and suitability to commercial spectrometers. Measurements of trace chemicals, such as adenine and cocaine, are also presented.

Effects of surface mining on fish and wildlife in Appalachia

USGS Publications Warehouse

Boccardy, Joseph A.; Spaulding, William M.

1968-01-01

This report on the effects of strip and surface mining on the fish and wildlife resources in eight Appalachian States is based in part on observation made during a tour of strip and surface mined area by the authors, as members of a team of specialist from six Federal agencies. Surface mining has caused extensive damage to fish and wildlife habitats and populations. A total of 832,605 acres of land have been disturbed; 81 percent of these are in Ohio, Pennsylvania, and West Virginia. More than 5,000 miles of Appalachian streams and 13,800 acres of impoundments have been seriously contaminated by acid mine water, some of it from surface mining. Additional water acreage has been adversely affected by tremendous quantities of silt and sediment. Reclamation of mined lands is needed. Three of the eight states visited in 1965-66 had no law requiring restoration of strip-mined lands, and other States needed stronger laws and more enforcement (Virginia and Tennessee have since passed laws governing strip mining). Reclamation as currently practiced in the Appalachian region does not adequately restore mined lands to minimal standards necessary to protect and improve fish and wildlife resources.

Roll-to-roll, shrink-induced superhydrophobic surfaces for antibacterial applications, enhanced point-of-care detection, and blood anticoagulation

NASA Astrophysics Data System (ADS)

Nokes, Jolie McLane

Superhydrophobic (SH) surfaces are desirable because of their unique anti-wetting behavior. Fluid prefers to bead up (contact angle >150°) and roll off (contact angle hysteresis <10°) a SH surface because micro- and nanostructure features trap air pockets. Fluid only adheres to the peaks of the structures, causing minimal adhesion to the surface. Here, shrink-induced SH plastics are fabricated for a plethora of applications, including antibacterial applications, enhanced point-of-care (POC) detection, and reduced blood coagulation. Additionally, these purely structural SH surfaces are achieved in a roll-to-roll (R2R) platform for scalable manufacturing. Because their self-cleaning and water resistant properties, structurally modified SH surfaces prohibit bacterial growth and obviate bacterial chemical resistance. Antibacterial properties are demonstrated in a variety of SH plastics by preventing gram-negative Escherichia coli (E. coli) bacterial growth >150x compared to flat when fluid is rinsed and >20x without rinsing. Therefore, a robust and stable means to prevent bacteria growth is possible. Next, protein in urine is detected using a simple colorimetric output by evaporating droplets on a SH surface. Contrary to evaporation on a flat surface, evaporation on a SH surface allows fluid to dramatically concentrate because the weak adhesion constantly decreases the footprint area. On a SH surface, molecules in solution are confined to a footprint area 8.5x smaller than the original. By concentrating molecules, greater than 160x improvements in detection sensitivity are achieved compared to controls. Utility is demonstrated by detecting protein in urine in the pre-eclampsia range (150-300microgmL -1) for pregnant women. Further, SH surfaces repel bodily fluids including blood, urine, and saliva. Importantly, the surfaces minimize blood adhesion, leading to reduced blood coagulation without the need for anticoagulants. SH surfaces have >4200x and >28x reduction of blood residue area and volume compared to the non-structured controls of the same material. In addition, blood clotting area is reduced >5x using whole blood directly from the patient. In this study, biocompatible SH surfaces are achieved using commodity shrink-wrap film and are scaled up for R2R manufacturing. The purely structural modification negates complex and expensive post processing, and SH features are achieved in commercially-available and FDA-approved plastics.

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

Boxley, Chett J.; Kadota, Rod

This research program performed by Ceramatec may significantly increase the beneficial utilization of fly ash, and improve the overall performance of high quality animal litter products. Ceramatec has developed a novel high surface area material, which is capable of ammonia adsorption. High surface area zeolites when combined with agglomerated fly ash can significantly reduce the use of naturally mined materials (i.e. clay bentonite) for animal litter manufacture. This not only preserves natural resources and the natural environment, but it also will reduce CO 2 emissions, via the reduced need for heavy mining equipment. This novel animal litter is made withmore » over 85% of recycled materials, thus preventing their disposition to landfills. The novel litter material is similar to traditional clay-like litters, and it is clumpable and has superior odor control properties.« less

Platinum Nanoparticle Decorated SiO2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion.

PubMed

Chen, Bolin; Garland, Nathaniel T; Geder, Jason; Pruessner, Marius; Mootz, Eric; Cargill, Allison; Leners, Anne; Vokshi, Granit; Davis, Jacob; Burns, Wyatt; Daniele, Michael A; Kogot, Josh; Medintz, Igor L; Claussen, Jonathan C

2016-11-16

Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H 2 O 2 ) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO 2 ) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts. The mercapto-silanization of the SiO 2 microfibers enables strong covalent attachment with PtNPs, and the resultant PtNP-SiO 2 fibers act as a robust, high surface area catalyst for H 2 O 2 decomposition. The PtNP-SiO 2 catalysts are fitted inside a micro UUV reaction chamber for vehicular propulsion; the catalysts can propel a micro UUV for 5.9 m at a velocity of 1.18 m/s with 50 mL of 50% (w/w) H 2 O 2 . The concomitance of facile fabrication, economic and scalable processing, and high performance-including a reduction in H 2 O 2 decomposition activation energy of 40-50% over conventional material catalysts-paves the way for using these nanostructured microfibers in modern, small-scale underwater vehicle propulsion systems.

Surface features of soil particles of three types of soils under different land use strategies

NASA Astrophysics Data System (ADS)

Matveeva, Nataliy; Kotelnikova, Anna; Rogova, Olga; Proskurnin, Mikhail

2017-04-01

Nowadays, there is a clear need in a deep investigation of molecular composition of soils and of its influence on surface characteristics of soil particles. The aim of this study is to evaluate the composition and properties of physical fractions in different soil types in determining functional specificity of soil solid-phase surface. The experiments were carried out with three different types of Russian soils—Sod-Podzolic, Chestnut, and Chernozem soils—under various treatments (fallow, different doses of mineral fertilizers and their aftereffects). The samples were separated into three fractions: silt (SF) with a particle size of <2 μm, light fraction (LF) with a density of <2 g/cm3, and residual fraction (RF) with a size >2 μm and the density >2 g/cm3. We measured specific surface area, surface hydrophobicity (contact angle, CA), ζ-potential, and the point of zero charge (PZC). For Chernozem and Chestnut soils and their fractions of we observed an increase in hydrophobicity for SF and RF under fertilizer treatment. At the sites not treated with fertilizers and aftereffect sites, the hydrophobicity of fractions was lower compared to the sites under treatment. The CA of the original soils and fractions were different: in 35% of cases CA was higher for SF and RF by 12-16%. The rest of samples demonstrated CA of all three physical fractions lower than CA of the original soil. The variability of the mean CA indicates considerable differences in ζ-potential and PZC between different types of soils and soil fractions. The results of potentiometric titration of PZC for Sod-Podzolic soil showed that all values are in acidic range, which suggests predominance of acidic functional groups at the surface of soil particles. Specific surface area determines soil sorption processes, bioavailability of nutrients, water etc. Here, specific surface area of Sod-Podzolic soil was low and SF-dependent. We calculated specific surface charge from obtained data on specific surface area and PZC. The results suggested considerable differences between sorption features of both soils and fractions under different land use strategies.

Surface texture change on-demand and microfluidic devices based on thickness mode actuation of dielectric elastomer actuators (DEAs)

NASA Astrophysics Data System (ADS)

Ankit, Ankit; Nguyen, Anh Chien; Mathews, Nripan

2017-04-01

Tactile feedback devices and microfluidic devices have huge significance in strengthening the area of robotics, human machine interaction and low cost healthcare. Dielectric Elastomer Actuators (DEAs) are an attractive alternative for both the areas; offering the advantage of low cost and simplistic fabrication in addition to the high actuation strains. The inplane deformations produced by the DEAs can be used to produce out-of-plane deformations by what is known as the thickness mode actuation of DEAs. The thickness mode actuation is achieved by adhering a soft passive layer to the DEA. This enables a wide area of applications in tactile applications without the need of complex systems and multiple actuators. But the thickness mode actuation has not been explored enough to understand how the deformations can be improved without altering the material properties; which is often accompanied with increased cost and a trade off with other closely associated material properties. We have shown the effect of dimensions of active region and non-active region in manipulating the out-of-plane deformation. Making use of this, we have been able to demonstrate large area devices and complex patterns on the passive top layer for the surface texture change on-demand applications. We have also been able to demonstrate on-demand microfluidic channels and micro-chambers without the need of actually fabricating the channels; which is a cost incurring and cumbersome process.

A global, spatially-explicit assessment of irrigated croplands influenced by urban wastewater flows

NASA Astrophysics Data System (ADS)

Thebo, A. L.; Drechsel, P.; Lambin, E. F.; Nelson, K. L.

2017-07-01

When urban areas expand without concomitant increases in wastewater treatment capacity, vast quantities of wastewater are released to surface waters with little or no treatment. Downstream of many urban areas are large areas of irrigated croplands reliant on these same surface water sources. Case studies document the widespread use of untreated wastewater in irrigated agriculture, but due to the practical and political challenges of conducting a true census of this practice, its global extent is not well known except where reuse has been planned. This study used GIS-based modeling methods to develop the first spatially-explicit estimate of the global extent of irrigated croplands influenced by urban wastewater flows, including indirect wastewater use. These croplands were further classified by their likelihood of using poor quality water based on the spatial proximity of croplands to urban areas, urban wastewater return flow ratios, and proportion of wastewater treated. This study found that 65% (35.9 Mha) of downstream irrigated croplands were located in catchments with high levels of dependence on urban wastewater flows. These same catchments were home to 1.37 billion urban residents. Of these croplands, 29.3 Mha were located in countries with low levels of wastewater treatment and home to 885 million urban residents. These figures provide insight into the key role that water reuse plays in meeting the water and food needs of people around the world, and the need to invest in wastewater treatment to protect public health.

Hydraulic Characteristics of Bedrock Constrictions and Evaluation of One- and Two-Dimensional Models of Flood Flow on the Big Lost River at the Idaho National Engineering and Environmental Laboratory, Idaho

USGS Publications Warehouse

Berenbrock, Charles; Rousseau, Joseph P.; Twining, Brian V.

2007-01-01

A 1.9-mile reach of the Big Lost River, between the Idaho National Engineering and Environmental Laboratory (INEEL) diversion dam and the Pioneer diversion structures, was investigated to evaluate the effects of streambed erosion and bedrock constrictions on model predictions of water-surface elevations. Two one-dimensional (1-D) models, a fixed-bed surface-water flow model (HEC-RAS) and a movable-bed surface-water flow and sediment-transport model (HEC-6), were used to evaluate these effects. The results of these models were compared to the results of a two-dimensional (2-D) fixed-bed model [Transient Inundation 2-Dimensional (TRIM2D)] that had previously been used to predict water-surface elevations for peak flows with sufficient stage and stream power to erode floodplain terrain features (Holocene inset terraces referred to as BLR#6 and BLR#8) dated at 300 to 500 years old, and an unmodified Pleistocene surface (referred to as the saddle area) dated at 10,000 years old; and to extend the period of record at the Big Lost River streamflow-gaging station near Arco for flood-frequency analyses. The extended record was used to estimate the magnitude of the 100-year flood and the magnitude of floods with return periods as long as 10,000 years. In most cases, the fixed-bed TRIM2D model simulated higher water-surface elevations, shallower flow depths, higher flow velocities, and higher stream powers than the fixed-bed HEC-RAS and movable-bed HEC-6 models for the same peak flows. The HEC-RAS model required flow increases of 83 percent [100 to 183 cubic meters per second (m3/s)], and 45 percent (100 to 145 m3/s) to match TRIM2D simulations of water-surface elevations at two paleoindicator sites that were used to determine peak flows (100 m3/s) with an estimated return period of 300 to 500 years; and an increase of 13 percent (150 to 169 m3/s) to match TRIM2D water-surface elevations at the saddle area that was used to establish the peak flow (150 m3/s) of a paleoflood with a return period of 10,000 years. A field survey of the saddle area, however, indicated that the elevation of the lowest point on the saddle area was 1.2 feet higher than indicated on the 2-ft contour map that was used in the TRIM2D model. Because of this elevation discrepancy, HEC-RAS model simulations indicated that a peak flow of at least 210 m3/s would be needed to initiate flow across the 10,000-year old Pleistocene surface. HEC-6 modeling results indicated that to compensate for the effects of streambed scour, additional flow increases would be needed to match HEC-RAS and TRIM2D water-surface elevations along the upper and middle reaches of the river, and to compensate for sediment deposition, a slight decrease in flows would be needed to match HEC-RAS water-surface elevations along the lower reach of the river. Differences in simulated water-surface elevations between the TRIM2D and the HEC-RAS and HEC-6 models are attributed primarily to differences in topographic relief and to differences in the channel and floodplain geometries used in these models. Topographic differences were sufficiently large that it was not possible to isolate the effects of these differences on simulated water-surface elevations from those attributable to the effects of supercritical flow, streambed scour, and sediment deposition.

An evaluation of campground conditions and needs for research

Treesearch

Arthur W. Magill; Eamor C. Nord

1963-01-01

Heavy use of 137 National Forest campgrounds and picnic areas surveyed in California has resulted in several critical types of site deterioration. More than half were inadequately stocked; four-fifths were disturbed 1963 by trampling , erosion, and mechanical means; and two-thirds had poor accumulations of protective plant litter on soil surfaces. Ecological studies of...

Water and water use in southern Nevada [Chapter 3

Treesearch

Wayne R. Belcher; Michael J. Moran; Megan E. Rogers

2013-01-01

Water and water use in southern Nevada is an important issue. The scarcity of water resources for both human and biologic communities often leads to intense competition for both surface and groundwaters. Anthropogenic and climate change impacts on scarce water resources need to be understood to assess human and ecosystem health for the study area.

"Advances in Linked Air Quality, Farm Management and Biogeochemistry Models to Address Bidrectional Ammonia Flux in CMAQ"

EPA Science Inventory

Recent increases in anthropogenic inputs of nitrogen to air, land and water media pose a growing threat to human health and ecosystems. Modeling of air-surface N flux is one area in need of improvement. Implementation of a linked air quality and cropland management system is de...

Thrust and Performance Study of Micro Pulsed Plasma Thrusters

DTIC Science & Technology

2010-03-01

Due to the high- voltage potential, numerous electrons are able to collect in a small area. As the collection of the electrons grows, the ...quasi- neutral plasma removes the need to have a second emitter of free electrons to neutralize the plasma like in the Hall thrusters. PPTs and µPPTs...surface of the cathode. The micro-protrusions

Iowa Commercial Pesticide Applicator Manual, Category 5: Aquatic Pest Control. CS-17.

ERIC Educational Resources Information Center

Jennings, Vivan M.; Ryan, Stephen O.

This manual provides information needed to meet specific standards for certification as a pesticide applicator. The text is concerned with the control of aquatic weeds in a variety of water use situations, i.e. static water, limited-flow impoundments and moving water. Also discussed are the principles of limited area application such as surface or…

Spontaneous Phase Transformation and Exfoliation of Rectangular Single-Crystal Zinc Hydroxy Dodecylsulfate Nanomembranes

Treesearch

Fei Wang; Joseph E. Jakes; Dalong Geng; Xudong Wang

2013-01-01

Free-standing two-dimensional (2D) nanostructures, exemplified by graphene and semiconductor nanomembranes, exhibit exotic electrical and mechanical properties and have great potential in electronic applications where devices need to be flexible or conformal to nonplanar surfaces. Based on our previous development of a substrate-free synthesis of large-area, free-...

Advances in Linked Air Quality, Farm Management and Biogeochemistry Models to Address Bidirectional Ammonia Flux in CMAQ

EPA Science Inventory

Recent increases in anthropogenic inputs of nitrogen to air, land and water media pose a growing threat to human health and ecosystems. Modeling of air-surface N flux is one area in need of improvement. Implementation of a linked air quality and cropland management system is de...

Enhanced Deep Blue Aerosol Retrieval Algorithm: The Second Generation

NASA Technical Reports Server (NTRS)

Hsu, N. C.; Jeong, M.-J.; Bettenhausen, C.; Sayer, A. M.; Hansell, R.; Seftor, C. S.; Huang, J.; Tsay, S.-C.

2013-01-01

The aerosol products retrieved using the MODIS collection 5.1 Deep Blue algorithm have provided useful information about aerosol properties over bright-reflecting land surfaces, such as desert, semi-arid, and urban regions. However, many components of the C5.1 retrieval algorithm needed to be improved; for example, the use of a static surface database to estimate surface reflectances. This is particularly important over regions of mixed vegetated and non- vegetated surfaces, which may undergo strong seasonal changes in land cover. In order to address this issue, we develop a hybrid approach, which takes advantage of the combination of pre-calculated surface reflectance database and normalized difference vegetation index in determining the surface reflectance for aerosol retrievals. As a result, the spatial coverage of aerosol data generated by the enhanced Deep Blue algorithm has been extended from the arid and semi-arid regions to the entire land areas.

Laboratory column experiments and transport modeling to evaluate retardation of uranium in an aquifer downgradient of a uranium in-situ recovery site

DOE PAGES

Dangelmayr, Martin A.; Reimus, Paul W.; Wasserman, Naomi L.; ...

2017-05-01

The purpose of this study was to determine the attenuation potential and retardation of uranium in sediments taken from boreholes at the Smith-Ranch Highland in-situ recovery (ISR) site. Five column experiments with four different sediments were conducted to study the effects of variable mineralogy and alkalinity on uranium breakthrough. Uranium transport was modeled with PHREEQC using a generalized composite surface complexation model (GC SCM) with one, two, and, three generic surfaces, respectively. Reactive surface areas were approximated with PEST using BET derived surface areas to constrain fitting parameters. Uranium breakthrough was delayed by a factor of 1.68, 1.69 and 1.47more » relative to the non-reactive tracer for three of the 5 experiments at an alkalinity of 540 mg/l. A sediment containing smectite and kaolinite retained uranium by a factor of 2.80 despite a lower measured BET surface area. Decreasing alkalinity to 360 mg/l from 540 mg/l increased retardation by a factor of 4.26. Model fits correlated well to overall BET surface area in the three columns where clay content was less than 1%. For the sediment with clay, models consistently understated uranium retardation when reactive surface sites were restricted by BET results. Calcite saturation was shown to be a controlling factor for uranium desorption as the pH of the system changes. A pH of 6 during a secondary background water flush remobilized previously sorbed uranium resulting in a secondary uranium peak at twice the influent concentrations. Furthermore, this study demonstrates the potential of GC SCM models to predict uranium transport in sediments with homogenous mineral composition, but highlights the need for further research to understand the role of sediment clay composition and calcite saturation in uranium transport.« less

Laboratory column experiments and transport modeling to evaluate retardation of uranium in an aquifer downgradient of a uranium in-situ recovery site

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

Dangelmayr, Martin A.; Reimus, Paul W.; Wasserman, Naomi L.

The purpose of this study was to determine the attenuation potential and retardation of uranium in sediments taken from boreholes at the Smith-Ranch Highland in-situ recovery (ISR) site. Five column experiments with four different sediments were conducted to study the effects of variable mineralogy and alkalinity on uranium breakthrough. Uranium transport was modeled with PHREEQC using a generalized composite surface complexation model (GC SCM) with one, two, and, three generic surfaces, respectively. Reactive surface areas were approximated with PEST using BET derived surface areas to constrain fitting parameters. Uranium breakthrough was delayed by a factor of 1.68, 1.69 and 1.47more » relative to the non-reactive tracer for three of the 5 experiments at an alkalinity of 540 mg/l. A sediment containing smectite and kaolinite retained uranium by a factor of 2.80 despite a lower measured BET surface area. Decreasing alkalinity to 360 mg/l from 540 mg/l increased retardation by a factor of 4.26. Model fits correlated well to overall BET surface area in the three columns where clay content was less than 1%. For the sediment with clay, models consistently understated uranium retardation when reactive surface sites were restricted by BET results. Calcite saturation was shown to be a controlling factor for uranium desorption as the pH of the system changes. A pH of 6 during a secondary background water flush remobilized previously sorbed uranium resulting in a secondary uranium peak at twice the influent concentrations. Furthermore, this study demonstrates the potential of GC SCM models to predict uranium transport in sediments with homogenous mineral composition, but highlights the need for further research to understand the role of sediment clay composition and calcite saturation in uranium transport.« less

Determination of Large-Scale Cloud Ice Water Concentration by Combining Surface Radar and Satellite Data in Support of ARM SCM Activities

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

Liu, Guosheng

2013-03-15

Single-column modeling (SCM) is one of the key elements of Atmospheric Radiation Measurement (ARM) research initiatives for the development and testing of various physical parameterizations to be used in general circulation models (GCMs). The data required for use with an SCM include observed vertical profiles of temperature, water vapor, and condensed water, as well as the large-scale vertical motion and tendencies of temperature, water vapor, and condensed water due to horizontal advection. Surface-based measurements operated at ARM sites and upper-air sounding networks supply most of the required variables for model inputs, but do not provide the horizontal advection term ofmore » condensed water. Since surface cloud radar and microwave radiometer observations at ARM sites are single-point measurements, they can provide the amount of condensed water at the location of observation sites, but not a horizontal distribution of condensed water contents. Consequently, observational data for the large-scale advection tendencies of condensed water have not been available to the ARM cloud modeling community based on surface observations alone. This lack of advection data of water condensate could cause large uncertainties in SCM simulations. Additionally, to evaluate GCMs cloud physical parameterization, we need to compare GCM results with observed cloud water amounts over a scale that is large enough to be comparable to what a GCM grid represents. To this end, the point-measurements at ARM surface sites are again not adequate. Therefore, cloud water observations over a large area are needed. The main goal of this project is to retrieve ice water contents over an area of 10 x 10 deg. surrounding the ARM sites by combining surface and satellite observations. Built on the progress made during previous ARM research, we have conducted the retrievals of 3-dimensional ice water content by combining surface radar/radiometer and satellite measurements, and have produced 3-D cloud ice water contents in support of cloud modeling activities. The approach of the study is to expand a (surface) point measurement to an (satellite) area measurement. That is, the study takes the advantage of the high quality cloud measurements (particularly cloud radar and microwave radiometer measurements) at the point of the ARM sites. We use the cloud ice water characteristics derived from the point measurement to guide/constrain a satellite retrieval algorithm, then use the satellite algorithm to derive the 3-D cloud ice water distributions within an 10° (latitude) x 10° (longitude) area. During the research period, we have developed, validated and improved our cloud ice water retrievals, and have produced and archived at ARM website as a PI-product of the 3-D cloud ice water contents using combined satellite high-frequency microwave and surface radar observations for SGP March 2000 IOP and TWP-ICE 2006 IOP over 10 deg. x 10 deg. area centered at ARM SGP central facility and Darwin sites. We have also worked on validation of the 3-D ice water product by CloudSat data, synergy with visible/infrared cloud ice water retrievals for better results at low ice water conditions, and created a long-term (several years) of ice water climatology in 10 x 10 deg. area of ARM SGP and TWP sites and then compared it with GCMs.« less

Screen Cage Ion Plating (SCIP) and scratch testing of polycrystalline aluminum oxide

NASA Technical Reports Server (NTRS)

Spalvins, Talivaldis; Sliney, Harold E.; Deadmore, Daniel L.

1992-01-01

A screen cage ion plating (SCIP) technique was developed to apply silver films on electrically nonconducting aluminum oxide. It is shown that SCIP has remarkable throwing power; surfaces to be coated need not be in direct line of sight with the evaporation source. Scratch tests, employing a diamond stylus with a 200 micro m radius tip, were performed on uncoated and on silver coated alumina. Subsequent surface analysis show that a significant amount of silver remains on the scratched surfaces, even in areas where high stylus load produced severe crack patterns in the ceramic. Friction coefficients were lowered during the scratch tests on the coated alumina indicating that this modification of the ion planting process should be useful for applying lubricating films of soft metals to electrical insulating materials. The very good throwing power of SCIP also strongly suggests general applicability of this process in other areas of technology, e.g., electronics, in addition to tribology.

Understanding Practical Catalysts Using a Surface Science Approach. The Importance of Strong Interaction between BaO and Al 2O 3 in NO x Storage Materials

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

Yi, Cheol-Woo W.; Kwak, Ja Hun; Peden, Charles H.F.

2007-09-21

Modern surface science techniques have been commonly applied to understand issues arising from practical catalytic systems.[1-4] However, the applicability of most of the results obtained from model systems has been limited, due, primarily, to the vastly different conditions studies on model and practical systems are carried out (catalyst composition, reaction conditions etc.).[5, 6] Therefore, the need to conduct experiments on compositionally similar systems (model and practical) is necessary to obtain valuable information on the workings of real catalysts. In this communication we demonstrate the utility of surface science studies on model catalysts in understanding the properties of high surface area,more » BaO-based NO x storage-reduction (NSR) catalysts.[7] We present evidence for the facile formation of surface barium aluminate-like species even at very low coverages of BaO. This Ba-aluminate layer, however, can react with NO 2 resulting in the formation of a bulk-like Ba(NO 3) 2 phase. In order to construct model catalysts that are representative of the practical NO x storage systems, we first needed to estimate the BaO covareges on the high surface area catalysts. Since the publication of the work by Fanson et al.[8], BaO loadings of 8 – 10 wt.% on a γ-alumina support (200 m 2/g) have been regarded as corresponding to one monolayer (ML) coverage, based on the unit cell size of bulk BaO. The coverage equivalent of one ML, however, was significantly underestimated. Assuming complete spreading of the BaO layer and using a Ba–O distance of ~ 2.77 Å (one unit of BaO occupies 1.53 × 10 -19 m 2), 10 wt.% loading of BaO would cover only about 1/3 of the alumina surface. Table 1 shows our calculated estimates of two-dimensional BaO coverages as a function of loading on a -Al 2O 3 surface (200 m 2/g) based on the lattice parameters of bulk BaO[9] (5.54 Å). Based on these values, for our model system studies we prepared BaO/Al 2O 3/NiAl(110) materials in which the BaO coverages were very close to those of 4, 8, and 20 wt.% BaO/γ-Al 2O 3 high surface area catalysts used in prior studies.« less

Surface water records of New Mexico, water year 1963

USGS Publications Warehouse

,

1964-01-01

This report is the third in a series presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States". Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in New Mexico were contained in Parts 7, 8, and 9 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5- year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of conterminous United States will be further subdivided.

[Determination of joint contact area using MRI].

PubMed

Yoshida, Hidenori; Kobayashi, Koichi; Sakamoto, Makoto; Tanabe, Yuji

2009-10-20

Elevated contact stress on the articular joints has been hypothesized to contribute to articular cartilage wear and joint pain. However, given the limitations of using contact stress and areas from human cadaver specimens to estimate articular joint stress, there is need for an in vivo method to obtain such data. Magnetic resonance imaging (MRI) has been shown to be a valid method of quantifying the human joint contact area, indicating the potential for in vivo assessment. The purpose of this study was to describe a method of quantifying the tibiofemoral joint contact area using MRI. The validity of this technique was established in porcine cadaver specimens by comparing the contact area obtained from MRI with the contact area obtained using pressure-sensitive film (PSF). In particular, we assessed the actual condition of contact by using the ratio of signal intensity of MR images of cartilage surfaces. Two fresh porcine cadaver knees were used. A custom loading apparatus was designed to apply a compressive load to the tibiofemoral joint. We measured the contact area by using MRI and PSF methods. When the ratio of signal intensity of the cartilage surface was 0.9, the error of the contact area between the MR image and PSF was about 6%. These results suggest that this MRI method may be a valuable tool in quantifying joint contact area in vivo.

Hydrologic connectivity: Quantitative assessments of hydrologic-enforced drainage structures in an elevation model

USGS Publications Warehouse

Poppenga, Sandra K.; Worstell, Bruce B.

2016-01-01

Elevation data derived from light detection and ranging present challenges for hydrologic modeling as the elevation surface includes bridge decks and elevated road features overlaying culvert drainage structures. In reality, water is carried through these structures; however, in the elevation surface these features impede modeled overland surface flow. Thus, a hydrologically-enforced elevation surface is needed for hydrodynamic modeling. In the Delaware River Basin, hydrologic-enforcement techniques were used to modify elevations to simulate how constructed drainage structures allow overland surface flow. By calculating residuals between unfilled and filled elevation surfaces, artificially pooled depressions that formed upstream of constructed drainage structure features were defined, and elevation values were adjusted by generating transects at the location of the drainage structures. An assessment of each hydrologically-enforced drainage structure was conducted using field-surveyed culvert and bridge coordinates obtained from numerous public agencies, but it was discovered the disparate drainage structure datasets were not comprehensive enough to assess all remotely located depressions in need of hydrologic-enforcement. Alternatively, orthoimagery was interpreted to define drainage structures near each depression, and these locations were used as reference points for a quantitative hydrologic-enforcement assessment. The orthoimagery-interpreted reference points resulted in a larger corresponding sample size than the assessment between hydrologic-enforced transects and field-surveyed data. This assessment demonstrates the viability of rules-based hydrologic-enforcement that is needed to achieve hydrologic connectivity, which is valuable for hydrodynamic models in sensitive coastal regions. Hydrologic-enforced elevation data are also essential for merging with topographic/bathymetric elevation data that extend over vulnerable urbanized areas and dynamic coastal regions.

Organic chemistry on solid surfaces

NASA Astrophysics Data System (ADS)

Ma, Zhen; Zaera, Francisco

2006-07-01

Chemistry on solid surfaces is central to many areas of practical interest such as heterogeneous catalysis, tribology, electrochemistry, and materials processing. With the development of many surface-sensitive analytical techniques in the past decades, great advances have been possible in our understanding of such surface chemistry at the molecular level. Earlier studies with model systems, single crystals in particular, have provided rich information about the adsorption and reaction kinetics of simple inorganic molecules. More recently, the same approach has been expanded to the study of the surface chemistry of relatively complex organic molecules, in large measure in connection with the selective synthesis of fine chemicals and pharmaceuticals. In this report, the chemical reactions of organic molecules and fragments on solid surfaces, mainly on single crystals of metals but also on crystals of metal oxides, carbides, nitrides, phosphides, sulfides and semiconductors as well as on more complex models such as bimetallics, alloys, and supported particles, are reviewed. A scheme borrowed from the organometallic and organic chemistry literature is followed in which key examples of representative reactions are cited first, and general reactivity trends in terms of both the reactants and the nature of the surface are then identified to highlight important mechanistic details. An attempt has been made to emphasize recent advances, but key earlier examples are cited as needed. Finally, correlations between surface and organometallic and organic chemistry, the relevance of surface reactions to applied catalysis and materials functionalization, and some promising future directions in this area are briefly discussed.

Contamination of ground water, surface water, and soil, and evaluation of selected ground-water pumping alternatives in the Canal Creek area of Aberdeen Proving Ground, Maryland

USGS Publications Warehouse

Lorah, Michelle M.; Clark, Jeffrey S.

1996-01-01

Chemical manufacturing, munitions filling, and other military-support activities have resulted in the contamination of ground water, surface water, and soil in the Canal Creek area of Aberdeen Proving Ground, Maryland. Chlorinated volatile organic compounds, including 1,1,2,2-tetrachloroethane and trichloroethylene, are widespread ground-water contaminants in two aquifers that are composed of unconsolidated sand and gravel. Distribution and fate of chlorinated organic compounds in the ground water has been affected by the movement and dissolution of solvents in their dense immiscible phase and by microbial degradation under anaerobic conditions. Detection of volatile organic contaminants in adjacent surface water indicates that shallow contaminated ground water discharges to surface water. Semivolatile organic compounds, especially polycyclic aromatic hydrocarbons, are the most prevalent organic contaminants in soils. Various trace elements, such as arsenic, cadmium, lead, and zinc, were found in elevated concentrations in ground water, surface water, and soil. Simulations with a ground-water-flow model and particle tracker postprocessor show that, without remedial pumpage, the contaminants will eventually migrate to Canal Creek and Gunpowder River. Simulations indicate that remedial pumpage of 2.0 million gallons per day from existing wells is needed to capture all particles originating in the contaminant plumes. Simulated pumpage from offsite wells screened in a lower confined aquifer does not affect the flow of contaminated ground water in the Canal Creek area.

Pilot monitoring study of ibuprofen in surface waters of north of Portugal.

PubMed

Paíga, Paula; Santos, Lúcia H M L M; Amorim, Célia G; Araújo, Alberto N; Montenegro, M Conceição B S M; Pena, Angelina; Delerue-Matos, Cristina

2013-04-01

Ibuprofen is amongst the most worldwide consumed pharmaceuticals. The present work presents the first data in the occurrence of ibuprofen in Portuguese surface waters, focusing in the north area of the country, which is one of the most densely populated areas of Portugal. Analysis of ibuprofen is based on pre-concentration of the analyte with solid phase extraction and subsequent determination with liquid chromatography coupled to fluorescence detection. A total of 42 water samples, including surface waters, landfill leachates, Wastewater Treatment Plant (WWTP), and hospital effluents, were analyzed in order to evaluate the occurrence of ibuprofen in the north of Portugal. In general, the highest concentrations were found in the river mouths and in the estuarine zone. The maximum concentrations found were 48,720 ng L(-1) in the landfill leachate, 3,868 ng L(-1) in hospital effluent, 616 ng L(-1) in WWTP effluent, and 723 ng L(-1) in surface waters (Lima river). Environmental risk assessment was evaluated and at the measured concentrations only landfill leachates reveal potential ecotoxicological risk for aquatic organisms. Owing to a high consumption rate of ibuprofen among Portuguese population, as prescribed and non-prescribed medicine, the importance of hospitals, WWTPs, and landfills as sources of entrance of pharmaceuticals in the environment was pointed out. Landfill leachates showed the highest contribution for ibuprofen mass loading into surface waters. On the basis of our findings, more studies are needed as an attempt to assess more vulnerable areas.

Reduced Blood Coagulation on Roll-to-Roll, Shrink-Induced Superhydrophobic Plastics.

PubMed

Nokes, Jolie M; Liedert, Ralph; Kim, Monica Y; Siddiqui, Ali; Chu, Michael; Lee, Eugene K; Khine, Michelle

2016-03-09

The unique antiwetting properties of superhydrophobic (SH) surfaces prevent the adhesion of water and bodily fluids, including blood, urine, and saliva. While typical manufacturable approaches to create SH surfaces rely on chemical and structural modifications, such approaches are expensive, require postprocessing, and are often not biocompatible. By contrast, it is demonstrated that purely structural SH features are easily formed using high throughput roll-to-roll (R2R) manufacturing by shrinking a prestressed thermoplastic with a thin, stiff layer of silver and calcium. These features are subsequently embossed into any commercially available and Food and Drug Administration (FDA)-approved plastic. The R2R SH surfaces have contact angles >150° and contact angle hysteresis <10°. Importantly, the surfaces minimize blood adhesion, leading to reduced blood coagulation without the need for anticoagulants. SH surfaces have >4200× reduction of blood residue area compared to the nonstructured controls of the same material. In addition, blood clotting is reduced >5× using whole blood directly from the patient. Furthermore, these surfaces can be easily configured into 3D shapes, as demonstrated with SH tubes. With the simple scale-up production and the eliminated need for anticoagulants to prevent clotting, the proposed conformable SH surfaces can be impactful for a wide range of medical tools, including catheters and microfluidic channels. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Homogeneous near surface activity distribution by double energy activation for TLA

NASA Astrophysics Data System (ADS)

Takács, S.; Ditrói, F.; Tárkányi, F.

2007-10-01

Thin layer activation (TLA) is a versatile tool for activating thin surface layers in order to study real-time the surface loss by wear, corrosion or erosion processes of the activated parts, without disassembling or stopping running mechanical structures or equipment. The research problem is the determination of the irradiation parameters to produce point-like or large area optimal activity-depth distribution in the sample. Different activity-depth profiles can be produced depending on the type of the investigated material and the nuclear reaction used. To produce activity that is independent of the depth up to a certain depth is desirable when the material removed from the surface by wear, corrosion or erosion can be collected completely. By applying dual energy irradiation the thickness of this quasi-constant activity layer can be increased or the deviation of the activity distribution from a constant value can be minimized. In the main, parts made of metals and alloys are suitable for direct activation, but by using secondary particle implantation the wear of other materials can also be studied in a surface range a few micrometers thick. In most practical cases activation of a point-like spot (several mm2) is enough to monitor the wear, corrosion or erosion, but for special problems relatively large surfaces areas of complicated spatial geometry need to be activated uniformly. Two ways are available for fulfilling this task, (1) production of large area beam spot or scanning the beam over the surface in question from the accelerator side, or (2) a programmed 3D movement of the sample from the target side. Taking into account the large variability of tasks occurring in practice, the latter method was chosen as the routine solution in our cyclotron laboratory.

Variable exchange between a stream and an aquifer in the Rio Grande Project Area

NASA Astrophysics Data System (ADS)

Sheng, Z.; Abudu, S.; Michelsen, A.; King, P.

2016-12-01

Both surface water and groundwater in the Rio Grande Project area in southern New Mexico and Far West Texas have been stressed by natural conditions such as droughts and human activities, including urban development and agricultural irrigation. In some area pumping stress in the aquifer becomes so great that it depletes the river flow especially during the irrigation season, typically from March through October. Therefore understanding such relationship between surface water and groundwater becomes more important in regional water resources planning and management. In this area, stream flows are highly regulated by the upstream reservoirs during the irrigation season and greatly influenced by return flows during non-irrigation season. During a drought additional groundwater pumping to supplement surface water shortage further complicates the surface water and groundwater interaction. In this paper the authors will use observation data and results of numerical models (MODFLOW) to characterize and quantify hydrological exchange fluxes between groundwater in the aquifers and surface water as well as impacts of groundwater pumping. The interaction shows a very interesting seasonal variation (irrigation vs. non-irrigation) as well as impact of a drought. Groundwater has been pumped for both municipal supplies and agricultural irrigation, which has imposed stresses toward both stream flows and aquifer storage. The results clearly show that historic groundwater pumping has caused some reaches of the river change from gaining stream to losing stream. Beyond the exchange between surface water and groundwater in the shallow aquifer, groundwater pumping in a deep aquifer could also enhance the exchanges between different aquifers through leaky confining layers. In the earlier history of pumping, pumping from the shallow aquifer is compensated by simple depletion of surface water, while deep aquifer tends to use the aquifer storage. With continued pumping, the cumulative stresses from deeper aquifers migrate upward, resulting in additional depletion of surface water. Eventually such impacts turn some reaches of a gaining river into a losing stream. The research finding provides information needed for future regional water planning and conjunctive management of surface water and groundwater resources.

Estimation of Land Surface Temperature for the Quantitative Analysis of Land Cover of Lower Areas of Sindh to Assess the Impacts of Climate Variability

NASA Astrophysics Data System (ADS)

Qaisar, Maha

2016-07-01

Due to the present land use practices and climate variability, drastic shifts in regional climate and land covers are easily seen and their future reduction and gain are too well predicted. Therefore, there is an increasing need for data on land-cover changes at narrow and broad spatial scales. In this study, a remote sensing-based technique for land-cover-change analysis is applied to the lower Sindh areas for the last decade. Landsat satellite products were analyzed on an alternate yearly basis, from 1990 to 2016. Then Land-cover-change magnitudes were measured and mapped for alternate years. Land Surface Temperature (LST) is one of the critical elements in the natural phenomena of surface energy and water balance at local and global extent. However, LST was computed by using Landsat thermal bands via brightness temperature and a vegetation index. Normalized difference vegetation index (NDVI) was interpreted and maps were achieved. LST reflected NDVI patterns with complexity of vegetation patterns. Along with this, Object Based Image Analysis (OBIA) was done for classifying 5 major classes of water, vegetation, urban, marshy lands and barren lands with significant map layouts. Pakistan Meteorological Department provided the climate data in which rainfall, temperature and air temperature are included. Once the LST and OBIA are performed, overlay analysis was done to correlate the results of LST with OBIA and LST with meteorological data to ascertain the changes in land covers due to increasing centigrade of LST. However, satellite derived LST was also correlated with climate data for environmental analysis and to estimate Land Surface Temperature for assessing the inverse impacts of climate variability. This study's results demonstrate the land-cover changes in Lower Areas of Sindh including the Indus Delta mostly involve variations in land-cover conditions due to inter-annual climatic variability and temporary shifts in seasonality. However it is too concluded that transitory alteration of the biophysical characteristics of the surface driven by variations in rainfall is the prevailing progression. Moreover, future work will focus on finer-scale analysis and validations of patterns of changes due to rapid urbanization and population explosion in poverty stricken areas of Sindh which are posing an adverse impact on the land utilization and in turn increasing the land surface temperature and ultimately more stress on the low lying areas of Sindh i.e. Indus Delta will be losing its productivity and capacity to bear biodiversity whether the fauna or flora. Hence, this regional scale problem will become a global concern. Therefore, it is needed to stop the menace in its starting phase to mitigate the problem and to bring minds on this horrendous situation.

Irrigated acreage and other land uses on the Snake River Plain, Idaho and eastern Oregon

USGS Publications Warehouse

Lindholm, Gerald F.; Goodell, S.A.

1986-01-01

Prompted by the need for a current, accurate, and repeatable delineation of irrigated acreage on the Snake River Plain, the U.S. Geological Survey entered into a cooperative agreement with the Idaho Department of Water Resources Image Analysis Facility and the U.S. Bureau of Reclamation to delineate 1980 land use form Landsat data. Irrigated acreage data were needed as input to groundwater flow models developed by the U.S. Geological Survey in a study of the regional aquifer system underlying the Snake River Plain. Single-date digital multispectral scanner data analyzed to delineate land-use classes. Source of irrigation water (surface water, ground water, and combined) was determined from county maps of 1975 water-related land use, data from previous investigations, and field checking. Surface-water diversions for irrigation on the Snake River Plain began in the 1840's. With the stimulus of Federal aid authorized by the Desert Land Act, Carey Act, and Reclamation Act, irrigated area increased rapidly in the early 1900's. By 1929, 2.2 million acres were irrigated. Ground water became and important source of irrigation water after World War II. In 1980, about 3.1 million acres of the Snake River Plain were irrigate: 2.0 million acres with surface water, 1.0 million with ground water, and 0.1 million with combined surface and ground water. About 5.2 million acres (half of the plain) are undeveloped rangeland, 1.0 million acres (one-tenth) are classified as barren. The remaining land is a mixture of dryland agriculture, water bodies, wetland, forests, and urban areas.

OAST Space Theme Workshop. Volume 3: Working group summary. 3: Sensors (E-3). A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2). D. Additional assessment

NASA Technical Reports Server (NTRS)

1976-01-01

Developments required to support the space power, SETI, solar system exploration and global services programs are identified. Instrumentation and calibration sensors (rather than scientific) are needed for the space power system. Highly sophisticated receivers for narrowband detection of microwave sensors and sensors for automated stellar cataloging to provide a mapping data base for SETI are needed. Various phases of solar system exploration require large area solid state imaging arrays from UV to IR; a long focal plane telescope; high energy particle detectors; advanced spectrometers; a gravitometer; and atmospheric distanalyzer; sensors for penetrometers; in-situ sensors for surface chemical analysis, life detection, spectroscopic and microscopic analyses of surface soils, and for meteorological measurements. Active and passive multiapplication sensors, advanced multispectral scanners with improved resolution in the UV and IR ranges, and laser techniques for advanced probing and oceanographic characterization will enhance for global services.

Novel use of magnetic biochars for the remediation of soils contaminated by contaminants of emerging concerns (CECs)

NASA Astrophysics Data System (ADS)

Sani, Badruddeen; Mrozik, Wojciech; Werner, David

2016-04-01

The advantage of using magnetic biochar over nonmagnetic biochar in amendments of contaminated soils is in the fact that the former can be easily removed from the soil matrix whenever the need arises, using simple principles of magnetism. In this study, magnetic biochar was produced using a simple co-precipitation technique. The resulting composite has about 33% (w/w) magnetic iron oxides, the presence of which resulted in modification of the biochar's surface characteristics such as BET surface area, porosity and point of zero charge. Modifications in these properties will most likely alter the CEC sorption properties of the biochar, hence the necessity for the proper evaluation of the possible trade off that exist between the need for magnetisation and altered sorption characteristics of the biochar. To achieve this, bottle point sorption experiments in aqueous solutions were conducted using activated and non-activated biochars in magnetic and nonmagnetic forms as sorbents and two pharmaceuticals -ibuprofen and diclofenac- as representative CECs. Sorption isotherms were evaluated and the data was fitted to Langmuir, Freundlich, Redlich-Peterson, Dubinin-Ashtakov and Polanyi-Dubinin-Manes isotherm models. Removal efficiencies and sorption capacities correlated well with the effective mass of pristine biochar used, therefore the sorption characteristics of both magnetic and nonmagnetic biochars are not detrimentally affected by the magnetite impregnation. Biochars in activated form show superior sorption capacities due to amplified surface area and better developed pores. Also, non-activated biochars needed to be used in higher amounts to achieve considerable level of CEC removal, thus they are more easily exhausted. Sorption was observed to decrease with a corresponding increase in solution pH. This suggests that sorption is favoured within the acidic pH range when the surfaces of the sorbents have net positive charge and the sorbates are in their neutral forms.

The Use of Solar Heating and Heat Cured Polymers for Lunar Surface Stabilization

NASA Technical Reports Server (NTRS)

Hintze, Paul; Curran, Jerry; Back, Reddy

2008-01-01

Dust ejecta can affect visibility during a lunar landing, erode nearby coated surfaces and get into mechanical assemblies of in-place infrastructure. Regolith erosion was observed at many of the Apollo landing sites. This problem needs to be addressed at the beginning of the lunar base missions, as the amount of infrastructure susceptible to problems will increase with each landing. Protecting infrastructure from dust and debris is a crucial step in its long term functionality. A proposed way to mitigate these hazards is to build a lunar launch pad. Other areas of a lunar habitat will also need surface stabilization methods to help mitigate dust hazards. Roads would prevent dust from being lifted during movement and dust free zones might be required for certain areas critical to crew safety or to critical science missions. Work at NASA Kennedy Space Center (KSC) is investigating methods of stabilizing the lunar regolith including: sintering the regolith into a solid and using heat or UV cured polymers to stabilize the surface. Sintering, a method in which powders are heated until fusing into solids, has been proposed as one way of building a Lunar launch/landing pad. A solar concentrator has been built and used in the field to sinter JSC-1 Lunar stimulant. Polymer palliatives are used by the military to build helicopter landing pads and roads in dusty and sandy areas. Those polymers are dispersed in a solvent (water), making them unsuitable for lunar use. Commercially available, solvent free, polymer powders are being investigated to determine their viability to work in the same way as the solvent borne terrestrial analog. This presentation will describe the ongoing work at KSC in this field. Results from field testing will be presented. Physical testing results, including compression and abrasion, of field and laboratory prepared samples will be presented.

Present morphoclimate and morphodynamics in the boreal Homla drainage basin system (Trøndelag, middle Norway)

NASA Astrophysics Data System (ADS)

Beylich, Achim A.

2017-04-01

It is generally accepted that ongoing and future climate change will cause major changes in Earth surface systems and environments. From a geomorphological point of view, it is accordingly of increasing importance to obtain a better understanding of the relationships between contemporary geomorphological processes and present-day climatic conditions to come to more reliable assessments of the possible geomorphological effects of climate change. Until recently, the present-day climate has often only been characterized by monthly and annual means or sum values of wind speed, air temperature and precipitation. As most geomorphological surface processes consist of discrete events which are only partly correlated to these meteorological means or sum values, there is an obvious need for an additional approach of statistical analysis of meteorological data. In this study the "morphoclimate" of the Homla drainage basin situated in a boreal environment in Trøndelag in middle Norway is analyzed. "Morphoclimate" according to Ahnert (e.g., 1982) is specially related to geomorphological needs and, in this sense, is defined as the totality of those climatic characteristics of an area that influence the type, frequency, duration and intensity of the exogenic geomorphologic processes in this area. The statistical method primarily used in this context is the magnitude-frequency analysis. Particular emphasis is on (i) the frequencies or recurrence intervals of meteorological events of given magnitudes, and (ii) the frequencies of geomorphologically important thresholds. Aspects of the current wind, temperature and precipitation regimes which control the type, frequency, duration and intensity of the contemporary denudational surface processes as well as the sedimentary budget in the selected study area are presented. Runoff in the boreal Homla drainage basin is occurring year-round and the contemporary morphodynamics are altogether characterized by a clear dominance of chemical denudation over mechanical fluvial denudation. The general intensity of the denudational surface processes operating under the present-day morphoclimate is low.

A numerical study of the effect of urbanization on the climate of Las Vegas metropolitan area

NASA Astrophysics Data System (ADS)

Kamal, S. M.; Huang, H. P.; Myint, S. W.

2014-12-01

Las Vegas is one of the fastest growing desert cities. Its developed area has doubled in the last 30 years. An accurate prediction of the effect of urbanization on the climate of the city is crucial for resource management and planning. In this study, we use the Weather Research and Forecasting (WRF) model coupled with a land surface and urban canopy model to investigate the effects of urbanization on the regional climate pattern around Las Vegas. High resolution numerical simulations are performed with a 3 km resolution over the metropolitan area. With identical lateral boundary conditions, three land-use land-cover maps, representing 2006, 1992 and hypothetical 1900, are used in multiple simulations. The differences in the simulated climate among those cases are used to quantify the urban effect. The simulated surface air temperature is validated against observational data from the weather station at the McCarran airport. It is found that urbanization affects substantial warming during the night but a minor cooling during the day. Detailed diagnostics of the surface energy budget are performed to help interpret this result. In addition, the emerging urban structures are found to have a mechanical effect of slowing down the climatological wind field over the urban area. The change in wind, in turn, leads to a secondary modification of the temperature structure within the air shed of the city. This finding suggests the need to combine the mechanical and thermodynamic effects to construct a complete picture of the influence of land cover on urban climate. In all cases of the simulations, it is also demonstrated that urbanization influences surface air temperature mainly within the metropolitan area.

Central Facilities Area Sewage Lagoon Evaluation

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

Cole, Mark R.

2013-12-01

The Central Facilities Area (CFA), located in Butte County, Idaho, at the Idaho National Laboratory has an existing wastewater system to collect and treat sanitary wastewater and non-contact cooling water from the facility. The existing treatment facility consists of three cells: Cell #1 has a surface area of 1.7 acres, Cell #2 has a surface area of 10.3 acres, and Cell #3 has a surface area of 0.5 acres. If flows exceed the evaporative capacity of the cells, wastewater is discharged to a 73.5-acre land application site that uses a center-pivot irrigation sprinkler system. As flows at CFA have decreasedmore » in recent years, the amount of wastewater discharged to the land application site has decreased from 13.64 million gallons in 2004 to no discharge in 2012 and 2013. In addition to the decreasing need for land application, approximately 7.7 MG of supplemental water was added to the system in 2013 to maintain a water level and prevent the clay soil liners in the cells from drying out and “cracking.” The Idaho National Laboratory is concerned that the sewage lagoons and land application site may be oversized for current and future flows. A further concern is the sustainability of the large volumes of supplemental water that are added to the system according to current operational practices. Therefore, this study was initiated to evaluate the system capacity, operational practices, and potential improvement alternatives, as warranted.« less

Application of a Groundwater Modeling Tool for Managing Hydrologically Connected Area in State of Nebraska, US

NASA Astrophysics Data System (ADS)

Li, R.; Flyr, B.; Bradley, J.; Pun, M.; Schneider, J.; Wietjes, J.; Chinta, S.

2014-12-01

Determination of the nature and degree of hydrologically connected groundwater and surface water resources is of paramount importance to integrated water management within the State of Nebraska to understand the impact of water uses on available supplies, such as depletion of streams and aquifers caused by groundwater pumping. The ability to quantify effects of surface water-groundwater hydrologic connection and interactions, is regarded as one of the most important steps towards effectively managing water resources in Nebraska and provides the basis for designating management areas. Designation of management areas allows the state and other management entities to focus various efforts and resources towards those projects that have the greatest impact to water users. Nebraska Department of Natural Resources (NDNR) developed a groundwater modeling tool, Cycle Well Analysis, to determine the areas defined to have a high degree of connectivity between groundwater and surface water (in accordance with the state regulations). This tool features two graphic user interfaces to allow the analysis to be fully compatible with most MODFLOW-based numerical groundwater models currently utilized by NDNR. Case studies showed that the tool, in combination of Geographic Information Systems (GIS), can be used to quantify the degree of stream depletion and delineate the boundary of hydrologically connected areas within different political boundaries and subbasins in Nebraska. This approach may be applied to other regions with similar background and need for integrated water management.

Using CFD Surface Solutions to Shape Sonic Boom Signatures Propagated from Off-Body Pressure

NASA Technical Reports Server (NTRS)

Ordaz, Irian; Li, Wu

2013-01-01

The conceptual design of a low-boom and low-drag supersonic aircraft remains a challenge despite significant progress in recent years. Inverse design using reversed equivalent area and adjoint methods have been demonstrated to be effective in shaping the ground signature propagated from computational fluid dynamics (CFD) off-body pressure distributions. However, there is still a need to reduce the computational cost in the early stages of design to obtain a baseline that is feasible for low-boom shaping, and in the search for a robust low-boom design over the entire sonic boom footprint. The proposed design method addresses the need to reduce the computational cost for robust low-boom design by using surface pressure distributions from CFD solutions to shape sonic boom ground signatures propagated from CFD off-body pressure.

Infrared fiber optic sensor for measurements of nonuniform temperature distributions

NASA Astrophysics Data System (ADS)

Belotserkovsky, Edward; Drizlikh, S.; Zur, Albert; Bar-Or, O.; Katzir, Abraham

1992-04-01

Infrared (IR) fiber optic radiometry of thermal surfaces offers several advantages over refractive optics radiometry. It does not need a direct line of sight to the measured thermal surface and combines high capability of monitoring small areas with high efficiency. These advantages of IR fibers are important in the control of nonuniform temperature distributions, in which the temperature of closely situated points differs considerably and a high spatial resolution is necessary. The theoretical and experimental transforming functions of the sensor during scanning of an area with a nonuniform temperature distribution were obtained and their dependence on the spacial location of the fiber and type of temperature distribution were analyzed. Parameters such as accuracy and precision were determined. The results suggest that IR fiber radiometric thermometry may be useful in medical applications such as laser surgery, hyperthermia, and hypothermia.

Study and design of cryogenic propellant acquisition systems. Volume 2: Supporting experimental program

NASA Technical Reports Server (NTRS)

Burge, G. W.; Blackmon, J. B.

1973-01-01

Areas of cryogenic fuel systems were identified where critical experimental information was needed either to define a design criteria or to establish the feasibility of a design concept or a critical aspect of a particular design. Such data requirements fell into three broad categories: (1) basic surface tension screen characteristics; (2) screen acquisition device fabrication problems; and (3) screen surface tension device operational failure modes. To explore these problems and to establish design criteria where possible, extensive laboratory or bench test scale experiments were conducted. In general, these proved to be quite successful and, in many instances, the test results were directly used in the system design analyses and development. In some cases, particularly those relating to operational-type problems, areas requiring future research were identified, especially screen heat transfer and vibrational effects.

Decoration of silicon nanostructures with copper particles for simultaneous selective capture and mass spectrometry detection of His-tagged model peptide.

PubMed

Coffinier, Yannick; Kurylo, Ievgen; Drobecq, Hervé; Szunerits, Sabine; Melnyk, Oleg; Zaitsev, Vladimir N; Boukherroub, Rabah

2014-10-21

We present in this work a simple and fast preparation method of a new affinity surface-assisted laser/desorption ionization mass spectrometry (SALDI-MS) substrate based on silicon nanostructures decorated with copper particles. The silicon nanostructures were fabricated by the metal-assisted chemical etching (MACE) method. Then, superhydrophilic areas surrounded by superhydrophobic regions were formed through hydrosilylation reaction of 1-octadecene, followed by local degradation of the octadecyl layer. After that, copper particles were deposited in the hydrophilic areas by using the electroless method. We have demonstrated that these surfaces were able to perform high selective capture of model His-tag peptide even in a complex mixture such as serum solution. Then, the captured peptide was detected by mass spectrometry at a femtomolar level without the need of organic matrix.

Treatment considerations in actinic keratosis.

PubMed

Goldenberg, G

2017-03-01

The chronic skin condition actinic keratosis (AK) is characterized by the formation of keratotic lesions of variable thickness that are poorly delimited. AK occurs on areas of the skin that have had long-term exposure to the sun or UV radiation. Although AKs may regress, they usually persist and can progress to squamous cell carcinoma (SCC). Clinicians are unable to predict which AKs will progress; therefore, both clinically visible lesions and subclinical, non-visible (i.e. the entire area affected by AK/field cancerization) should be treated. AK treatment options include lesion-directed therapies that target specific AK lesions and field-directed therapies that target multiple clinical lesions and the underlying field damage. This article reviews currently available treatment options in AK, with a focus on patient-applied field therapies, and their suitability according to specific disease characteristics and patient needs. Choice of treatment in AK depends on lesion-, patient- and treatment-related factors and should be individualized. Considerations when choosing a therapy include site of application, treatment duration, surface area of application, tolerability profiles and implications on adherence. Field-directed therapies treat clinical and subclinical damage (i.e. the entire area affected by AK), achieve high rates of sustained clearance of AKs and may reduce the risk of progression to SCC. There is a clear need for field therapies with short duration of treatment and predictable, short-lived, mild local skin reactions that can be used over a large surface area. Therapies with shorter and simpler treatment courses are often associated with better adherence than treatments with longer courses. These may, therefore, represent more appropriate choices in patients for whom convenience and/or adherence are an issue. © 2017 European Academy of Dermatology and Venereology.

Chemical and geotechnical assessment of low organic foundation soils across the coastal area of Southwestern Nigeria

NASA Astrophysics Data System (ADS)

Adebisi, N. O.; Osammor, J.; Oluwafemi, O. S.

2018-04-01

Pressure on land use has caused great site development along the coastal area of south western Nigeria. However, research works for the purpose of evaluating appropriate depths of foundations in the area were without cognizance of engineering challenges that may ensue as a result of the organic content, and associated factors of the soils. This paper evaluates the compositional effects of the soils on foundation materials, and a phenomenological model of compressibility of fines during design and construction of problem-free foundations in the area. Thirty (30) disturbed soils were analysed for moisture content, grain size distribution, consistency limits, chloride, pH and sulphate, while the oedometer consolidation test was carried out on another 30 undisturbed soils. The stratigraphic sequence in the profile comprises medium dense to coarse grained silty clayey sand to 16.80 m depth, below loose grey organic silty clayey sand from the surface. Results show in most cases, that the foundation soils contain insignificant percentages (0.95-5.8%) of organic solids. Moisture content (44-70%), chloride (74.9 ppm), sulphate (420 ppm) ions concentration and pH (8.96) could enhance the corrosive potential of the soils. It is recommended that Portland cement concrete will be suitable in the environment. Foundation settlement with respect to surface area (0.028≤ mv ≤ 0.434m2MN-1 at 200 kNm-2; 0.038mv ≤ 0.776m2MN-1 at 400 kNm-2; 0.038≤ mv ≤ 0.879m2MN-1 at 800 kNm-2) ranges from low to medium compressibility with respect to consolidation pressure. Therefore, footings load need be spread over the soils, and foundation design need be based on site-specific soil information.

Water-resources programs and hydrologic-information needs, Marion County, Indiana, 1987

USGS Publications Warehouse

Duwelius, R.F.

1990-01-01

Water resources are abundant in Marion County, Indiana, and have been developed for public and industrial supply, energy generation, irrigation, and recreation. The largest water withdrawals are from surface water, and the two largest water uses are public supply and cooling water for electrical-generating plants. Water-resources programs in the county are carried out by Federal, State and local agencies to address issues of surface and groundwater availability and quality. The programs of each agency are related to the functions and goals of the agency. Although each agency has specific information needs to fulfill its functions, sometimes these needs overlap, and there are times when the same hydrologic information benefits all. Overlapping information needs and activities create opportunities for interagency coordination and cooperation. Such cooperation could lead to a savings of dollars spent on water-resources programs and could assure an improved understanding of the water resources of the county. Representatives from four agencies-- the Indiana Department of Environmental Management, the Indiana Department of Natural Resources, the Indianapolis Department of Public Works, and the U.S. Geological Survey--met four times in 1987 to describe their own water-resources programs, to identify hydrologic-information needs, and to contact other agencies with related programs. This report presents the interagency findings and is intended to further communication among water resource agencies by identifying current programs and common needs for hydrologic information. Hydrologic information needs identified by the agency representatives include more precise methods for determining the volume of water withdrawals and for determining the volume of industrial and municipal discharges to surface water. Maps of flood-prone areas need to be updated as more of the county is developed. Improved aquifer maps of the inter-till aquifers are needed, and additional observation wells are needed in the inter-till and bedrock aquifers. Finally, immediate access to instantaneous precipitation data is needed to assess flooding potential. (USGS)

Adsorption characteristics of activated carbon fibers (ACFs) for toluene: application in respiratory protection.

PubMed

Balanay, Jo Anne G; Bartolucci, Alfred A; Lungu, Claudiu T

2014-01-01

Granular activated carbon (GAC) is currently the standard adsorbent in respirators against several gases and vapors because of its efficiency, low cost, and available technology. However, a drawback of GAC due to its granular form is its need for containment, adding weight and bulkiness to respirators. This makes respirators uncomfortable to wear, resulting in poor compliance in their use. Activated carbon fibers (ACF) are considered viable alternative adsorbent materials for developing thinner, light-weight, and efficient respirators because of their larger surface area, lighter weight, and fabric form. This study aims to determine the critical bed depth and adsorption capacity of different types of commercially available ACFs for toluene to understand how thin a respirator can be and the service life of the adsorbents, respectively. ACF in cloth (ACFC) and felt (ACFF) forms with three different surface areas per form were tested. Each ACF type was challenged with six concentrations of toluene (50, 100, 200, 300, 400, 500 ppm) at constant air temperature (23°C), relative humidity (50%), and airflow (16 LPM) at different adsorbent weights and bed depths. Breakthrough data were obtained for each adsorbent using gas chromatography with flame ionization detector. The ACFs' surface areas were measured by an automatic physisorption analyzer. The results showed that ACFC has a lower critical bed depth and higher adsorption capacity compared to ACFF with similar surface area for each toluene concentration. Among the ACF types, ACFC2000 (cloth with the highest measured surface area of 1614 ± 5 m(2)/g) has one of the lowest critical bed depths (ranging from 0.11-0.22 cm) and has the highest adsorption capacity (ranging from 595-878 mg/g). Based on these studied adsorption characteristics, it is concluded that ACF has great potential for application in respiratory protection against toluene, particularly the ACFC2000, which is the best candidate for developing thinner and efficient respirators.

Monitoring monthly surface water dynamics of Dongting Lake using Sentinel-1 data at 10 m.

PubMed

Xing, Liwei; Tang, Xinming; Wang, Huabin; Fan, Wenfeng; Wang, Guanghui

2018-01-01

High temporal resolution water distribution maps are essential for surface water monitoring because surface water exhibits significant inner-annual variation. Therefore, high-frequency remote sensing data are needed for surface water mapping. Dongting Lake, the second-largest freshwater lake in China, is famous for the seasonal fluctuations of its inundation extents in the middle reaches of the Yangtze River. It is also greatly affected by the Three Gorges Project. In this study, we used Sentinel-1 data to generate surface water maps of Dongting Lake at 10 m resolution. First, we generated the Sentinel-1 time series backscattering coefficient for VH and VV polarizations at 10 m resolution by using a monthly composition method. Second, we generated the thresholds for mapping surface water at 10 m resolution with monthly frequencies using Sentinel-1 data. Then, we derived the monthly surface water distribution product of Dongting Lake in 2016, and finally, we analyzed the inner-annual surface water dynamics. The results showed that: (1) The thresholds were -21.56 and -15.82 dB for the backscattering coefficients for VH and VV, respectively, and the overall accuracy and Kappa coefficients were above 95.50% and 0.90, respectively, for the VH backscattering coefficient, and above 94.50% and 0.88, respectively, for the VV backscattering coefficient. The VV backscattering coefficient achieved lower accuracy due to the effect of the wind causing roughness on the surface of the water. (2) The maximum and minimum areas of surface water were 2040.33 km 2 in July, and 738.89 km 2 in December. The surface water area of Dongting Lake varied most significantly in April and August. The permanent water acreage in 2016 was 556.35 km 2 , accounting for 19.65% of the total area of Dongting Lake, and the acreage of seasonal water was 1525.21 km 2 . This study proposed a method to automatically generate monthly surface water at 10 m resolution, which may contribute to monitoring surface water in a timely manner.

Need for new caries detection methods

NASA Astrophysics Data System (ADS)

Young, Douglas A.; Featherstone, John D. B.

1999-05-01

Dental caries (tooth decay) continues to be a major problems for adults as well as children, even though great advances have been made in preventive methods in the last 20 years. New methods for the management of caries will work best if lesions can be detected at an early stage and chemical rather than physical intervention can take place, thereby preserving the natural tooth structure and helping the saliva to heal, or remineralize, the areas of early decay. Clinical detection of caries in the US relies on visual examination, tactile with hand held explorer, and conventional radiographs, all of which are inadequate for the occlusal (biting) surfaces of the teeth where most of the decay now occurs. The dentist often has to explore by drilling with a dental bur to confirm early decay in these areas. New method that can determine the extent and degree of subsurface lesions in these surfaces non-destructively are essential for further advances in the clinical management of dental caries. Optical methods, which exploit the differences between sound and carious enamel and dentin, show great promise for the accurate detection of these lesions. Two or three- dimensional images, which include a measure of severity will be needed.

Albuquerque, New Mexico, USA: A sunbelt city rapidly outgrowing its aquifer

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

Turin, H.J.; Gaume, A.N.; Bitner, M.J.

1997-02-01

Albuquerque, New Mexico, is located along the Rio Grande in central New Mexico, at an elevation of 5280 feet. Albuquerque`s climate reflects its high desert setting; average annual precipitation in the basin is only 8 to 10 inches. The Albuquerque metropolitan area is part of the rapidly growing {open_quotes}sunbelt{close_quotes} region of the southwestern United States and is undergoing rapid development. The municipal, industrial, and residential water needs of the entire population are currently met by groundwater, while agricultural needs within the basin are met by surface water diverted from the Rio Grande. While the city is blessed with an extremelymore » productive aquifer, current metropolitan area annual groundwater extractions of 170,000 acre-feet far exceed the sustainable yield of the aquifer. Continued drawdown will lead to greater pumping costs, ground surface subsidence problems, and eventual aquifer depletion. At the same time, industrial and non-point-source contamination and naturally occurring arsenic levels are raising concerns about groundwater quality. New Mexico water law has required the City to acquire surface water rights and allocations on the Rio Grande sufficient to offset estimated losses from the river induced by the City`s groundwater extraction. It has become increasingly clear that the induced recharge had been greatly overestimated, and that the City is thus not actually consuming its surface water as intended. The City, in cooperation with local, state, and federal agencies, has explored a variety of conjunctive use proposals, all designed to permit the City to use its surface water more directly. The City Council is presently considering a strategy calling for full use of the city`s surface water resources and creation of a groundwater drought reserve. Implementation of this strategy will require regulatory approval and major capital investment, both of which require political support.« less

The influence of badland surfaces and erosion processes on vegetation cover

NASA Astrophysics Data System (ADS)

Hardenbicker, Ulrike; Matheis, Sarah

2014-05-01

To assess the links between badland geomorphology and vegetation cover, we used detailed mapping in the Avonlea badlands, 60 km southwest of Regina, Saskatchewan Canada. Three badlands surfaces are typical in the study area: a basal pediment surface, a mid-slope of bentonitic mudstone with typical popcorn surface, and an upper slope with mud-cemented sandstone. Badland development was triggered by rapid post Pleistocene incision of a meltwater channel in Upper Cretaceous marine and lagoonal sediments. After surveying and mapping of a test area, sediment samples were taken to analyze geophysical parameters. A detailed geomorphic map and vegetation map (1:1000) were compared and analyzed in order to determine the geomorphic environment for plant colonization. The shrink-swell capacity of the bentonitic bedrock, slaking potential and dispersivity are controlled by soil texture, clay mineralogy and chemistry, strongly influencing the timing and location of runoff and the relative significance of surface and subsurface erosional processes. The absence of shrink-swell cracking of the alluvial surfaces of the pediments indicates a low infiltration capacity and sheetflow. The compact lithology of the sandstone is responsible for its low permeability and high runoff coefficient. Slope drainage of steep sandstone slopes is routed through a deep corrasional pipe network. Silver sagebrush (Artemisia cana) is the only species growing on the popcorn surface of the mudrock, which is in large parts vegetation free. The basal pediment shows a distinct 2 m band surrounding the mudrock outcrop without vegetation as a result of high sedimentation rate due to slope wash. Otherwise the typical pioneer vegetation of this basal pediment are grasses. In the transition zone below the steep sandstone cliffs and above the gentle bentonitic mudrock surfaces patches of short-grass vegetation are found, marking slumped blocks with intact vegetation and soil cover. These patches are surrounded by less dense pioneer vegetation consisting of grasses and sage bushes indicating minimal surface erosion or sedimentation. Geomorphic mapping documented a high density of active pipes in this area, transporting silt and fine sand from the sandstone cliffs to lower and basal pediments. Vegetation cover alone is a poor indicator of badland surfaces and erosion processes because of the three-dimensional nature of badland erosion processes, and the shrink-swell capacity of the bentonitic bedrock. A combination of geomorphic and vegetation mapping is needed to identify badland surfaces and processes in the study area.

Using a 3D tool to document and determine graft loss: A mini-review and case report.

PubMed

Benjamin, Nicole C; Wurzer, Paul; Voigt, Charles D; Benjamin, Debra A; Herndon, David N

2016-06-01

In severe burns, accurate determination of burn wound size and areas of debridement and graft loss is challenging. In this case report, we describe the use of 3D wound measurement software (BurnCase 3D, RISC Software GmbH, Hagenberg, Austria) in a 29-year-old patient with burns covering 92% of the total body surface area. BurnCase 3D was used to assess burn and monitor all surgical interventions. The software allowed us to calculate areas of graft loss and graft take throughout the acute hospitalization (until 90% of the wounds were covered with homografts). It also enabled preoperative planning for wound coverage and blood loss. Thus, BurnCase 3D appears to be a useful tool for accurate determination of burn wound areas and preoperative planning. However, whether the benefit of more efficient preoperative planning overcomes the disadvantage of the additional time needed to document the wound using the software needs to be evaluated further. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Surface Gravity Data Contribution to the Puerto Rico and U.S. Virgin Islands Geoid Model

NASA Astrophysics Data System (ADS)

Li, X.; Gerhards, C.; Holmes, S. A.; Saleh, J.; Shaw, B.

2015-12-01

The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project provides updated local gravity field information for the XGEOID15 models. In particular, its airborne gravity data in the area of Puerto Rico and U.S. Virgin Islands (PRVI) made substantial improvements (~60%) on the precision of the geoid models at the local GNSS/Leveling bench marks in the target area. Fortunately, PRVI is free of the huge systematic error in the North American Vertical Datum of 1988 (NAVD88). Thus, the airborne contribution was evaluated more realistically. In addition, the airborne data picked up more detailed gravity field information in the medium wavelength band (spherical harmonic degree 200 to 600) that are largely beyond the resolution of the current satellite missions, especially along the nearby ocean trench areas. Under this circumstance (significant airborne contributions in the medium band), local surface gravity data need to be examined more carefully than before during merging with the satellite and airborne information for local geoid improvement, especially considering the well-known systematic problems in the NGS historical gravity holdings (Saleh et al 2013 JoG). Initial tests showed that it is very important to maintain high consistency between the surface data sets and the airborne enhanced reference model. In addition, a new aggregation method (Gerhards 2014, Inverse Problems) will also be tested to optimally combine the local surface data with the reference model. The data cleaning and combining procedures in the target area will be summarized here as reference for future applications.

Methane fluxes from tropical coastal lagoons surrounded bymangroves, Yucatán, Mexico

USGS Publications Warehouse

Chuang, Pei-Chuan; Young, Megan B.; Dale, Andrew W.; Miller, Laurence G.; Herrera-Silveira, Jorge A; Paytan, Adina

2017-01-01

Methane concentrations in the water column and emissions to the atmosphere were determined for three tropical coastal lagoons surrounded by mangrove forests on the Yucatán Peninsula, Mexico. Surface water dissolved methane was sampled at different seasons over a period of 2 years in areas representing a wide range of salinities and anthropogenic impacts. The highest surface water methane concentrations (up to 8378 nM) were measured in a polluted canal associated with Terminos Lagoon. In Chelem Lagoon, methane concentrations were typically lower, except in the polluted harbor area (1796 nM). In the relatively pristine Celestún Lagoon, surface water methane concentrations ranged from 41 to 2551 nM. Methane concentrations were negatively correlated with salinity in Celestún, while in Chelem and Terminos high methane concentrations were associated with areas of known pollution inputs, irrespective of salinity. The diffusive methane flux from surface lagoon water to the atmosphere ranged from 0.0023 to 15 mmol CH4 m−2 d−1. Flux chamber measurements revealed that direct methane release as ebullition was up to 3 orders of magnitude greater than measured diffusive flux. Coastal mangrove lagoons may therefore be an important natural source of methane to the atmosphere despite their relatively high salinity. Pollution inputs are likely to substantially enhance this flux. Additional statistically rigorous data collected globally are needed to better consider methane fluxes from mangrove-surrounded coastal areas in response to sea level changes and anthropogenic pollution in order to refine projections of future atmospheric methane budgets.

Practical issues for using solar-reflective materials to mitigate urban heat islands

NASA Astrophysics Data System (ADS)

Bretz, Sarah; Akbari, Hashem; Rosenfeld, Arthur

Solar-reflective or high-albedo, alternatives to traditionally absorptive urban surfaces such as rooftops and roadways can reduce cooling energy use and improve urban air quality at almost no cost. This paper presents information to support programs that mitigate urban heat islands with solar-reflective surfaces: estimates of the achievable increase in albedo for a variety of surfaces, issues related to the selection of materials and costs and benefits of using them. As an example, we present data for Sacramento, California. In Sacramento, we estimate that 20% of the 96 square mile area is dark roofing and 10% is dark pavement. Based on the change in albedo that is achievable for these surfaces, the overall albedo of Sacramento could be increased by 18%, a change that would produce significant energy savings and increase comfort within the city. Roofing market data indicate which roofing materials should be targeted for incentive programs. In 1995, asphalt shingle was used for over 65% of residential roofing area in the U.S. and 6% of commercial. Built-up roofing was used for about 5% of residential roofing and about 30% of commercial roofing. Single-ply membranes covered about 9% of the residential roofing area and over 30% of the commercial area. White, solar-reflective alternatives are presently available for these roofing materials but a low- first-cost, solar-reflective alternative to asphalt shingles is needed to capture the sloped-roof market. Since incoming solar radiation has a large non-visible component, solar-reflective materials can also be produced in a variety of colors.

Procedural Documentation and Accuracy Assessment of Bathymetric Maps and Area/Capacity Tables for Small Reservoirs

USGS Publications Warehouse

Wilson, Gary L.; Richards, Joseph M.

2006-01-01

Because of the increasing use and importance of lakes for water supply to communities, a repeatable and reliable procedure to determine lake bathymetry and capacity is needed. A method to determine the accuracy of the procedure will help ensure proper collection and use of the data and resulting products. It is important to clearly define the intended products and desired accuracy before conducting the bathymetric survey to ensure proper data collection. A survey-grade echo sounder and differential global positioning system receivers were used to collect water-depth and position data in December 2003 at Sugar Creek Lake near Moberly, Missouri. Data were collected along planned transects, with an additional set of quality-assurance data collected for use in accuracy computations. All collected data were imported into a geographic information system database. A bathymetric surface model, contour map, and area/capacity tables were created from the geographic information system database. An accuracy assessment was completed on the collected data, bathymetric surface model, area/capacity table, and contour map products. Using established vertical accuracy standards, the accuracy of the collected data, bathymetric surface model, and contour map product was 0.67 foot, 0.91 foot, and 1.51 feet at the 95 percent confidence level. By comparing results from different transect intervals with the quality-assurance transect data, it was determined that a transect interval of 1 percent of the longitudinal length of Sugar Creek Lake produced nearly as good results as 0.5 percent transect interval for the bathymetric surface model, area/capacity table, and contour map products.

Pulmonary function test in healthy school children of 8 to 14 years age in south Gujarat region, India

PubMed Central

Doctor, Tahera H.; Trivedi, Sangeeta S.; Chudasama, Rajesh K.

2010-01-01

Objective: To obtain reference values for FEV1, FVC, FEV1% and PEFR among children aged 8-14 years in south Gujarat region of India. Materials and Methods: This cross-sectional study was conducted among 655 normal healthy school children (408 boys and 247 girls) of Surat city aged 8 to 14 years studying in V to VII standard during November 2007 to April 2008. Height, weight, body surface area were measured. All included children were tested in a sitting position with the head straight after taking written consent from parents. Spirometry was done using the spirometer “Spirolab II” MIR 010. Spirometer used in the study facilitates the total valuation of lung function including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory volume ratio in one second (FEV1%) and peak expiratory flow rate (PEFR). Results: FVC, FEV1 and PEFR were found to be statistically significant in the study groups. For FVC and FEV1, highest correlation was found with age in girls and height in boys. For FEV1%, significant negative correlation was found with age and height in both sexes, but positive correlation was found with surface area. Similarly, PEFR showed highest correlation with surface area in boys and girls. Conclusion: Variables such as FVC, FEV1 and PEFR show good positive correlation with height, age and body surface area in both sexes. There is a need to have regional values for the prediction of normal spirometric parameters in a country like India with considerable diversity. PMID:20931033

Methane fluxes from tropical coastal lagoons surrounded by mangroves, Yucatán, Mexico

NASA Astrophysics Data System (ADS)

Chuang, P.-C.; Young, M. B.; Dale, A. W.; Miller, L. G.; Herrera-Silveira, J. A.; Paytan, A.

2017-05-01

Methane concentrations in the water column and emissions to the atmosphere were determined for three tropical coastal lagoons surrounded by mangrove forests on the Yucatán Peninsula, Mexico. Surface water dissolved methane was sampled at different seasons over a period of 2 years in areas representing a wide range of salinities and anthropogenic impacts. The highest surface water methane concentrations (up to 8378 nM) were measured in a polluted canal associated with Terminos Lagoon. In Chelem Lagoon, methane concentrations were typically lower, except in the polluted harbor area (1796 nM). In the relatively pristine Celestún Lagoon, surface water methane concentrations ranged from 41 to 2551 nM. Methane concentrations were negatively correlated with salinity in Celestún, while in Chelem and Terminos high methane concentrations were associated with areas of known pollution inputs, irrespective of salinity. The diffusive methane flux from surface lagoon water to the atmosphere ranged from 0.0023 to 15 mmol CH4 m-2 d-1. Flux chamber measurements revealed that direct methane release as ebullition was up to 3 orders of magnitude greater than measured diffusive flux. Coastal mangrove lagoons may therefore be an important natural source of methane to the atmosphere despite their relatively high salinity. Pollution inputs are likely to substantially enhance this flux. Additional statistically rigorous data collected globally are needed to better consider methane fluxes from mangrove-surrounded coastal areas in response to sea level changes and anthropogenic pollution in order to refine projections of future atmospheric methane budgets.

Comparison of plantar pressures and contact area between normal and cavus foot.

PubMed

Fernández-Seguín, Lourdes M; Diaz Mancha, Juan Antonio; Sánchez Rodríguez, Raquel; Escamilla Martínez, Elena; Gómez Martín, Beatriz; Ramos Ortega, Javier

2014-02-01

In pes cavus, the medial longitudinal arch elevation reduces the contact surface area and consequently increases the corresponding plantar pressure measurements. This poor distribution of loads may produce associated pathology and pain in this or other areas of the body. Normal reference values need to be established in order to determine which patterns are prone to pathology. To compare the plantar pressures and weight-bearing surface in a population with pes cavus to a population with neutral feet. The sample comprised 68 adults, 34 with pes cavus and 34 with neutral feet. The Footscan USB Gait Clinical System(®) was used as a platform to measure the total contact area and plantar pressure under the forefoot, midfoot, hindfoot, each metatarsal head, and the overall metatarsal area. A statistical analysis of the data was performed using Student's t-test for independent samples. The pes cavus subjects showed a significant reduction in their weight-bearing area [neutral feet: 165.04 ( ± 20.68) cm(2); pes cavus: 118.26 ( ± 30.31) cm(2); p < 0.001] and significantly increased pressures under all zones of the forefoot except the fifth metatarsal [metatarsal pressure: in neutral feet 503,797 ( ± 9.32) kPa; in pes cavus 656.12 ( ± 22.39) kPa; p < 0.001]. Compared to neutral feet, pes cavus feet show a reduction in total contact surface and the load under the first toe. A significant increase is present in the load under the metatarsal areas, but the relative distribution of this load is similar in both groups. Copyright © 2013 Elsevier B.V. All rights reserved.

Surface Infiltration Rates of Permeable Surfaces: Six Month ...

EPA Pesticide Factsheets

At the end of October 2009, EPA opened a parking lot on the Edison Environmental Center that included three parking rows of permeable pavement. The construction was a cooperative effort among EPA’s Office of Administration and Resources Management, National Risk Management Research Laboratory, and the facility owner, Region 2. The lot serves as an active parking area for facility staff and visitors and also as a research platform. Key unknowns in the application of green infrastructure include the long term performance and the maintenance requirements. The perceived uncertainty in these is a barrier to widespread adoption of the installation of permeable surfaces for stormwater management. EPA recognizes the need for credible long-term performance maintenance data and has begun a long-term monitoring effort on this installation. This document outlines the methods and results of the surface infiltration monitoring of the permeable parking surfaces during the first six months of operation. To inform the public.

How coalescing droplets jump.

PubMed

Enright, Ryan; Miljkovic, Nenad; Sprittles, James; Nolan, Kevin; Mitchell, Robert; Wang, Evelyn N

2014-10-28

Surface engineering at the nanoscale is a rapidly developing field that promises to impact a range of applications including energy production, water desalination, self-cleaning and anti-icing surfaces, thermal management of electronics, microfluidic platforms, and environmental pollution control. As the area advances, more detailed insights of dynamic wetting interactions on these surfaces are needed. In particular, the coalescence of two or more droplets on ultra-low adhesion surfaces leads to droplet jumping. Here we show, through detailed measurements of jumping droplets during water condensation coupled with numerical simulations of binary droplet coalescence, that this process is fundamentally inefficient with only a small fraction of the available excess surface energy (≲ 6%) convertible into translational kinetic energy. These findings clarify the role of internal fluid dynamics during the jumping droplet coalescence process and underpin the development of systems that can harness jumping droplets for a wide range of applications.

Single-step fabrication of polydimethylsiloxane microwell arrays with long-lasting hydrophilic inner surfaces

NASA Astrophysics Data System (ADS)

Gowa Oyama, Tomoko; Barba, Bin Jeremiah Duenas; Hosaka, Yuji; Taguchi, Mitsumasa

2018-05-01

We propose a single-step fabrication method for polydimethylsiloxane (PDMS) cell-adhesive microwell arrays with long-lasting (>10 months in aqueous medium) hydrophilic inner surfaces without the need for any chemical treatment such as development. Irradiation of a PDMS film with a low-energy electron beam (55 kV) in air generated a ˜40-μm-thick hydrophilic silica-like layer on the PDMS surface, which was the key to the prolonged hydrophilicity. Moreover, the concomitant compaction of the irradiated area produced dozens-of-micrometers-deep concave wells. The hydrophilic microwells generated on the hydrophobic non-irradiated PDMS surface easily trapped nano-/picoliter droplets and cells/single-cells. In addition, the surfaces of the microwells offered stable and favorable cell-adherent environments. The method presented here can realize stable and reliable lab-on-chips and cater to the expanding demand in biological and medical applications.

Water-Table Levels and Gradients, Nevada, 1947-2004

USGS Publications Warehouse

Lopes, Thomas J.; Buto, Susan G.; Smith, J. LaRue; Welborn, Toby L.

2006-01-01

In 1999, the U.S. Environmental Protection Agency began a program to protect the quality of ground water in areas other than ground-water protection areas. These other sensitive ground water areas (OSGWA) are areas that are not currently, but could eventually be, used as a source of drinking water. The OSGWA program specifically addresses existing wells that are used for underground injection of motor-vehicle waste. To help determine whether a well is in an OSGWA, the Nevada Division of Environmental Protection needs statewide information on depth to water and the water table, which partly control the susceptibility of ground water to contamination and contaminant transport. This report describes a study that used available maps and data to create statewide maps of water-table and depth-to-water contours and surfaces, assessed temporal changes in water-table levels, and characterized water-table gradients in selected areas of Nevada. A literature search of published water-table and depth-to-water contours produced maps of varying detail and scope in 104 reports published from 1948 to 2004. Where multiple maps covered the same area, criteria were used to select the most recent, detailed maps that covered the largest area and had plotted control points. These selection criteria resulted in water-table and depth-to-water contours that are based on data collected from 1947 to 2004 being selected from 39 reports. If not already available digitally, contours and control points were digitized from selected maps, entered into a geographic information system, and combined to make a statewide map of water-table contours. Water-table surfaces were made by using inverse distance weighting to estimate the water table between contours and then gridding the estimates. Depth-to-water surfaces were made by subtracting the water-table altitude from the land-surface altitude. Water-table and depth-to-water surfaces were made for only 21 percent of Nevada because of a lack of information for 49 of 232 basins and for most consolidated-rock hydrogeologic units. Depth to water is commonly less than 50 feet beneath valley floors, 50 to 500 feet beneath alluvial fans, and more than 500 feet in some areas such as north-central and southern Nevada. In areas without water-table information, greasewood and mapped ground-water discharge areas are good indicators of depth to water less than 100 feet. The average difference between measured depth to water and depth to water estimated from surfaces was 90 feet. More recent and detailed information may be needed than that presented in this report to evaluate a specific site. Temporal changes in water-table levels were evaluated for 1,981 wells with 10 or more years between the first depth-to-water measurement and last measurement made since 1990. The greatest increases in depth to water occurred where the first measurement was less than 200 feet, where the time between first and last measurements was 40 years or less, and for wells between 100 and 600 feet deep. These characteristics describe production wells where ground water is fairly shallow in recently developing areas such as the Las Vegas and Reno metropolitan areas. In basins with little pumping, 90 percent of the changes during the past 100 years are within ?20 feet, which is about the natural variation in the water table due to changes in the climate and recharge. Gradients in unconsolidated sediments of the Great Basin are generally steep near mountain fronts, shallow beneath valley floors, and depend on variables such as the horizontal hydraulic conductivity of adjacent consolidated rocks and recharge. Gradients beneath alluvial fans and valley floors at 58 sites were correlated with selected variables to identify those variables that are statistically related. Water-table measurements at three sites were used to characterize the water table between the valley floor and consolidated rock. Water-table gradients beneath alluvial fan

Efficacy of "green" cleaning products with respect to common respiratory viruses and mold growth.

PubMed

Light, Ed

2009-05-01

Some disinfectants have been demonstrated to be effective against surface mold growth and/or viruses responsible for the spread of common respiratory infections. Antimicrobial efficacy of green cleaning products has generally not been established in these areas. In this survey, the author found that out of 27 products approved by Green Seal as hard surface cleaners, 26 do not claim antimicrobial capability. While some contained hydrogen peroxide, a compound with limited spectrum disinfection capabilities, only one was registered with the U.S. Environmental Protection Agency as antimicrobial. The need for additional research and documentation is discussed.

A reflection model for eclipsing binary stars

NASA Technical Reports Server (NTRS)

Wood, D. B.

1973-01-01

A highly accurate reflection model has been developed which emphasizes efficiency of computer calculation. It is assumed that the heating of the irradiated star must depend upon the following properties of the irradiating star: (1) effective temperature; (2) apparent area as seen from a point on the surface of the irradiated star; (3) limb darkening; and (4) zenith distance of the apparent centre as seen from a point on the surface of the irradiated star. The algorithm eliminates the need to integrate over the irradiating star while providing a highly accurate representation of the integrated bolometric flux, even for gravitationally distorted stars.

A Bright Idea for the Eyes

NASA Technical Reports Server (NTRS)

2004-01-01

The WEstinghouse Lighting Corporation's Eye Saver[TM] Easy Reading Light Bulb is the result of collaboration between Westinghouse, Marshall Research LLC, and NASA's Space Optics Manufacturing Technology Center at Marshall Space Flight Center. The light bulb contains a chrome top that directs light to areas where it is needed most. The bulb, which lasts 2,000 hours, provides 40 percent more surface illumination on work and reading surfaces, compared to a standard incandescent bulb. The lightly frosted finish reduces glare, which helps to reduce eyestrain. The bulb is particularly helpful for people with low vision and eye diseases such as macular degeneration.

Development of new maskless manufacturing method for anti-reflection structure and application to large-area lens with curved surface

NASA Astrophysics Data System (ADS)

Yamamoto, Kazuya; Takaoka, Toshimitsu; Fukui, Hidetoshi; Haruta, Yasuyuki; Yamashita, Tomoya; Kitagawa, Seiichiro

2016-03-01

In general, thin-film coating process is widely applied on optical lens surface as anti-reflection function. In normal production process, at first lens is manufactured by molding, then anti-reflection is added by thin-film coating. In recent years, instead of thin-film coating, sub-wavelength structures adding on surface of molding die are widely studied and development to keep anti-reflection performance. As merits, applying sub-wavelength structure, coating process becomes unnecessary and it is possible to reduce man-hour costs. In addition to cost merit, these are some technical advantages on this study. Adhesion of coating depends on material of plastic, and it is impossible to apply anti-reflection function on arbitrary surface. Sub-wavelength structure can solve both problems. Manufacturing method of anti-reflection structure can be divided into two types mainly. One method is with the resist patterning, and the other is mask-less method that does not require patterning. What we have developed is new mask-less method which is no need for resist patterning and possible to impart an anti-reflection structure to large area and curved lens surface, and can be expected to apply to various market segments. We report developed technique and characteristics of production lens.

Adaptive wettability-enhanced surfaces ordered on molded etched substrates using shrink film

NASA Astrophysics Data System (ADS)

Jayadev, Shreshta; Pegan, Jonathan; Dyer, David; McLane, Jolie; Lim, Jessica; Khine, Michelle

2013-01-01

Superhydrophobic surfaces in nature exhibit desirable properties including self-cleaning, bacterial resistance, and flight efficiency. However, creating such intricate multi-scale features with conventional fabrication approaches is difficult, expensive, and not scalable. By patterning photoresist on pre-stressed shrink-wrap film, which contracts by 95% in surface area when heated, such features over large areas can be obtained easily. Photoresist serves as a dry etch mask to create complex and high-aspect ratio microstructures in the film. Using a double-shrink process, we introduce adaptive wettability-enhanced surfaces ordered on molded etched (AWESOME) substrates. We first create a mask out of the children’s toy ‘Shrinky-Dinks’ by printing dots using a laserjet printer. Heating this thermoplastic sheet causes the printed dots to shrink to a fraction of their original size. We then lithographically transfer the inverse pattern onto photoresist-coated shrink-wrap polyolefin film. The film is then plasma etched. After shrinking, the film serves as a high-aspect ratio mold for polydimethylsiloxane, creating a superhydrophobic surface with water contact angles >150° and sliding angles <10°. We pattern a microarray of ‘sticky’ spots with a dramatically different sliding angle compared to that of the superhydrophobic region, enabling microtiter-plate type assays without the need for a well plate.

Diagnostic and model dependent uncertainty of simulated Tibetan permafrost area

USGS Publications Warehouse

Wang, A.; Moore, J.C.; Cui, Xingquan; Ji, D.; Li, Q.; Zhang, N.; Wang, C.; Zhang, S.; Lawrence, D.M.; McGuire, A.D.; Zhang, W.; Delire, C.; Koven, C.; Saito, K.; MacDougall, A.; Burke, E.; Decharme, B.

2016-01-01

 We perform a land-surface model intercomparison to investigate how the simulation of permafrost area on the Tibetan Plateau (TP) varies among six modern stand-alone land-surface models (CLM4.5, CoLM, ISBA, JULES, LPJ-GUESS, UVic). We also examine the variability in simulated permafrost area and distribution introduced by five different methods of diagnosing permafrost (from modeled monthly ground temperature, mean annual ground and air temperatures, air and surface frost indexes). There is good agreement (99 to 135  ×  104 km2) between the two diagnostic methods based on air temperature which are also consistent with the observation-based estimate of actual permafrost area (101  × 104 km2). However the uncertainty (1 to 128  ×  104 km2) using the three methods that require simulation of ground temperature is much greater. Moreover simulated permafrost distribution on the TP is generally only fair to poor for these three methods (diagnosis of permafrost from monthly, and mean annual ground temperature, and surface frost index), while permafrost distribution using air-temperature-based methods is generally good. Model evaluation at field sites highlights specific problems in process simulations likely related to soil texture specification, vegetation types and snow cover. Models are particularly poor at simulating permafrost distribution using the definition that soil temperature remains at or below 0 °C for 24 consecutive months, which requires reliable simulation of both mean annual ground temperatures and seasonal cycle, and hence is relatively demanding. Although models can produce better permafrost maps using mean annual ground temperature and surface frost index, analysis of simulated soil temperature profiles reveals substantial biases. The current generation of land-surface models need to reduce biases in simulated soil temperature profiles before reliable contemporary permafrost maps and predictions of changes in future permafrost distribution can be made for the Tibetan Plateau.

Diagnostic and model dependent uncertainty of simulated Tibetan permafrost area

NASA Astrophysics Data System (ADS)

Wang, W.; Rinke, A.; Moore, J. C.; Cui, X.; Ji, D.; Li, Q.; Zhang, N.; Wang, C.; Zhang, S.; Lawrence, D. M.; McGuire, A. D.; Zhang, W.; Delire, C.; Koven, C.; Saito, K.; MacDougall, A.; Burke, E.; Decharme, B.

2016-02-01

We perform a land-surface model intercomparison to investigate how the simulation of permafrost area on the Tibetan Plateau (TP) varies among six modern stand-alone land-surface models (CLM4.5, CoLM, ISBA, JULES, LPJ-GUESS, UVic). We also examine the variability in simulated permafrost area and distribution introduced by five different methods of diagnosing permafrost (from modeled monthly ground temperature, mean annual ground and air temperatures, air and surface frost indexes). There is good agreement (99 to 135 × 104 km2) between the two diagnostic methods based on air temperature which are also consistent with the observation-based estimate of actual permafrost area (101 × 104 km2). However the uncertainty (1 to 128 × 104 km2) using the three methods that require simulation of ground temperature is much greater. Moreover simulated permafrost distribution on the TP is generally only fair to poor for these three methods (diagnosis of permafrost from monthly, and mean annual ground temperature, and surface frost index), while permafrost distribution using air-temperature-based methods is generally good. Model evaluation at field sites highlights specific problems in process simulations likely related to soil texture specification, vegetation types and snow cover. Models are particularly poor at simulating permafrost distribution using the definition that soil temperature remains at or below 0 °C for 24 consecutive months, which requires reliable simulation of both mean annual ground temperatures and seasonal cycle, and hence is relatively demanding. Although models can produce better permafrost maps using mean annual ground temperature and surface frost index, analysis of simulated soil temperature profiles reveals substantial biases. The current generation of land-surface models need to reduce biases in simulated soil temperature profiles before reliable contemporary permafrost maps and predictions of changes in future permafrost distribution can be made for the Tibetan Plateau.

Investigating scintillometer source areas

NASA Astrophysics Data System (ADS)

Perelet, A. O.; Ward, H. C.; Pardyjak, E.

2017-12-01

Scintillometry is an indirect ground-based method for measuring line-averaged surface heat and moisture fluxes on length scales of 0.5 - 10 km. These length scales are relevant to urban and other complex areas where setting up traditional instrumentation like eddy covariance is logistically difficult. In order to take full advantage of scintillometry, a better understanding of the flux source area is needed. The source area for a scintillometer is typically calculated as a convolution of point sources along the path. A weighting function is then applied along the path to compensate for a total signal contribution that is biased towards the center of the beam path, and decreasing near the beam ends. While this method of calculating the source area provides an estimate of the contribution of the total flux along the beam, there are still questions regarding the physical meaning of the weighted source area. These questions are addressed using data from an idealized experiment near the Salt Lake City International Airport in northern Utah, U.S.A. The site is a flat agricultural area consisting of two different land uses. This simple heterogeneity in the land use facilitates hypothesis testing related to source areas. Measurements were made with a two wavelength scintillometer system spanning 740 m along with three standard open-path infrared gas analyzer-based eddy-covariance stations along the beam path. This configuration allows for direct observations of fluxes along the beam and comparisons to the scintillometer average. The scintillometer system employed measures the refractive index structure parameter of air for two wavelengths of electromagnetic radiation, 880 μm and 1.86 cm to simultaneously estimate path-averaged heat and moisture fluxes, respectively. Meteorological structure parameters (CT2, Cq2, and CTq) as well as surface fluxes are compared for various amounts of source area overlap between eddy covariance and scintillometry. Additionally, surface properties from LANDSAT 7 & 8 are used to help understand source area composition for different times throughout the experiment.

Biomedical surface analysis: Evolution and future directions (Review)

PubMed Central

Castner, David G.

2017-01-01

This review describes some of the major advances made in biomedical surface analysis over the past 30–40 years. Starting from a single technique analysis of homogeneous surfaces, it has been developed into a complementary, multitechnique approach for obtaining detailed, comprehensive information about a wide range of surfaces and interfaces of interest to the biomedical community. Significant advances have been made in each surface analysis technique, as well as how the techniques are combined to provide detailed information about biological surfaces and interfaces. The driving force for these advances has been that the surface of a biomaterial is the interface between the biological environment and the biomaterial, and so, the state-of-the-art in instrumentation, experimental protocols, and data analysis methods need to be developed so that the detailed surface structure and composition of biomedical devices can be determined and related to their biological performance. Examples of these advances, as well as areas for future developments, are described for immobilized proteins, complex biomedical surfaces, nanoparticles, and 2D/3D imaging of biological materials. PMID:28438024

Atmospheric particulate matter in proximity to mountaintop coal mines: Sources and potential environmental and human health impacts

USGS Publications Warehouse

Kurth, Laura; Kolker, Allan; Engle, Mark A.; Geboy, Nicholas J.; Hendryx, Michael; Orem, William H.; McCawley, Michael; Crosby, Lynn M.; Tatu, Calin A.; Varonka, Matthew S.; DeVera, Christina A.

2015-01-01

Mountaintop removal mining (MTM) is a widely used approach to surface coal mining in the US Appalachian region whereby large volumes of coal overburden are excavated using explosives, removed, and transferred to nearby drainages below MTM operations. To investigate the air quality impact of MTM, the geochemical characteristics of atmospheric particulate matter (PM) from five surface mining sites in south central West Virginia, USA, and five in-state study control sites having only underground coal mining or no coal mining whatsoever were determined and compared. Epidemiologic studies show increased rates of cancer, respiratory disease, cardiovascular disease, and overall mortality in Appalachian surface mining areas compared to Appalachian non-mining areas. In the present study, 24-h coarse (>2.5 µm) and fine (≤2.5 µm) PM samples were collected from two surface mining sites in June 2011 showed pronounced enrichment in elements having a crustal affinity (Ga, Al, Ge, Rb, La, Ce) contributed by local sources, relative to controls. Follow-up sampling in August 2011 lacked this enrichment, suggesting that PM input from local sources is intermittent. Using passive samplers, dry deposition total PM elemental fluxes calculated for three surface mining sites over multi-day intervals between May and August 2012 were 5.8 ± 1.5 times higher for crustal elements than at controls. Scanning microscopy of 2,249 particles showed that primary aluminosilicate PM was prevalent at surface mining sites compared to secondary PM at controls. Additional testing is needed to establish any link between input of lithogenic PM and disease rates in the study area.

Atmospheric particulate matter in proximity to mountaintop coal mines: sources and potential environmental and human health impacts.

PubMed

Kurth, Laura; Kolker, Allan; Engle, Mark; Geboy, Nicholas; Hendryx, Michael; Orem, William; McCawley, Michael; Crosby, Lynn; Tatu, Calin; Varonka, Matthew; DeVera, Christina

2015-06-01

Mountaintop removal mining (MTM) is a widely used approach to surface coal mining in the US Appalachian region whereby large volumes of coal overburden are excavated using explosives, removed, and transferred to nearby drainages below MTM operations. To investigate the air quality impact of MTM, the geochemical characteristics of atmospheric particulate matter (PM) from five surface mining sites in south central West Virginia, USA, and five in-state study control sites having only underground coal mining or no coal mining whatsoever were determined and compared. Epidemiologic studies show increased rates of cancer, respiratory disease, cardiovascular disease, and overall mortality in Appalachian surface mining areas compared to Appalachian non-mining areas. In the present study, 24-h coarse (>2.5 µm) and fine (≤2.5 µm) PM samples were collected from two surface mining sites in June 2011 showed pronounced enrichment in elements having a crustal affinity (Ga, Al, Ge, Rb, La, Ce) contributed by local sources, relative to controls. Follow-up sampling in August 2011 lacked this enrichment, suggesting that PM input from local sources is intermittent. Using passive samplers, dry deposition total PM elemental fluxes calculated for three surface mining sites over multi-day intervals between May and August 2012 were 5.8 ± 1.5 times higher for crustal elements than at controls. Scanning microscopy of 2,249 particles showed that primary aluminosilicate PM was prevalent at surface mining sites compared to secondary PM at controls. Additional testing is needed to establish any link between input of lithogenic PM and disease rates in the study area.

Spotted star light curve numerical modeling technique and its application to HII 1883 surface imaging

NASA Astrophysics Data System (ADS)

Kolbin, A. I.; Shimansky, V. V.

2014-04-01

We developed a code for imaging the surfaces of spotted stars by a set of circular spots with a uniform temperature distribution. The flux from the spotted surface is computed by partitioning the spots into elementary areas. The code takes into account the passing of spots behind the visible stellar limb, limb darkening, and overlapping of spots. Modeling of light curves includes the use of recent results of the theory of stellar atmospheres needed to take into account the temperature dependence of flux intensity and limb darkening coefficients. The search for spot parameters is based on the analysis of several light curves obtained in different photometric bands. We test our technique by applying it to HII 1883.

Progress in remote sensing of global land surface heat fluxes and evaporations with a turbulent heat exchange parameterization method

NASA Astrophysics Data System (ADS)

Chen, Xuelong; Su, Bob

2017-04-01

Remote sensing has provided us an opportunity to observe Earth land surface with a much higher resolution than any of GCM simulation. Due to scarcity of information for land surface physical parameters, up-to-date GCMs still have large uncertainties in the coupled land surface process modeling. One critical issue is a large amount of parameters used in their land surface models. Thus remote sensing of land surface spectral information can be used to provide information on these parameters or assimilated to decrease the model uncertainties. Satellite imager could observe the Earth land surface with optical, thermal and microwave bands. Some basic Earth land surface status (land surface temperature, canopy height, canopy leaf area index, soil moisture etc.) has been produced with remote sensing technique, which already help scientists understanding Earth land and atmosphere interaction more precisely. However, there are some challenges when applying remote sensing variables to calculate global land-air heat and water exchange fluxes. Firstly, a global turbulent exchange parameterization scheme needs to be developed and verified, especially for global momentum and heat roughness length calculation with remote sensing information. Secondly, a compromise needs to be innovated to overcome the spatial-temporal gaps in remote sensing variables to make the remote sensing based land surface fluxes applicable for GCM model verification or comparison. A flux network data library (more 200 flux towers) was collected to verify the designed method. Important progress in remote sensing of global land flux and evaporation will be presented and its benefits for GCM models will also be discussed. Some in-situ studies on the Tibetan Plateau and problems of land surface process simulation will also be discussed.

Risk Factors Detection for Strategic Importance Objectives in Littoral Areas

NASA Astrophysics Data System (ADS)

Slămnoiu, G.; Radu, O.; Roşca, V.; Pascu, C.; Surdu, G.; Curcă, E.; Damian, R. G.; Rădulescu, A.

2017-06-01

With the invention and development of underwater explosive devices the need to neutralize them has also appeared, both for enemy and for own devices once conflicts are finished. The fight against active underwater explosive devices is a very complicated action that requires a very careful approach. Also, in the current context, strategic importance objectives located in the littoral areas can also become targets for divers or fast boats (suicidal actions).The system for detection, localization, tracking and identification of risk factors for strategic importance objectives in littoral areas has as one of its components an AUV and a hydro-acoustic sub-system for determining the ‘fingerprints’ of potential targets. The overall system will provide support for main missions such as underwater environment surveillance (detection, monitoring) in harbor areas and around other coast objectives, ship anchorage areas, mandatory pass points and also provide warnings about the presence of underwater and surface dangers in the interest areas.

Surface water records of New Mexico, water year 1961

USGS Publications Warehouse

,

1962-01-01

The surface-water records for the 1961 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of New Mexico are given in this report. For convenience there are also included for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U. S. Geological Survey, under the direction of W. L. Heckler, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U. S. Geological Survey water supply papers entitled "Surface Water Supply of the United States." Since 1951 there has been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in New Mexico were contained in Parts 7, 8, and 9 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports On a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey watersupply paper at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of conterminous United States will be further subdivided.

Surface water records of Indiana, 1962

USGS Publications Warehouse

,

1962-01-01

The surface-water records for the 1962 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Surface water records of Indiana, 1963

USGS Publications Warehouse

,

1963-01-01

The surface-water records for the 1963 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Surface water records of Indiana, 1964

USGS Publications Warehouse

,

1964-01-01

The surface-water records for the 1964 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Surface water records of Indiana, 1961

USGS Publications Warehouse

,

1961-01-01

The surface-water records for the 1961 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Integration of LIDAR Data Into a Municipal GIS to Study Solar Radiation

NASA Astrophysics Data System (ADS)

Africani, P.; Bitelli, G.; Lambertini, A.; Minghetti, A.; Paselli, E.

2013-04-01

Identifying the right roofs to install solar panels inside a urban area is crucial for both private citizens and the whole local population. The aim is not easy because a lot of consideration must be made: insolation, orientation of the surface, size of the surface, shading due to topography, shading due to taller buildings next the surface, shading due to taller vegetation and other possible problems typical of urban areas like the presence of chimneys. Accuracy of data related to the analyzed surfaces is indeed fundamental, and also the detail of geometric models used to represent buildings and their roofs. The complexity that these roofs can reach is elevated. This work uses LiDAR data to obtain, with a semi-automatic technique, the full geometry of each roof part complementing the pre-existing building data in the municipal cartography. With this data is possible to evaluate the placement of solar panels on roofs of a whole city analyzing the solar potential of each building in detail. Other traditional techniques, like photogrammetry, need strong manual editing effort in order to identify slopes and insert vector on surfaces at the right height. Regarding LiDAR data, in order to perform accurate modelling, it is necessary to obtain an high density point cloud. The method proposed can also be used as a fast and linear workflow process for an area where LiDAR data are available and a municipal cartography already exist: LiDAR data can be furthermore successfully used to cross-check errors in pre-existent digital cartography that can remain otherwise hidden.

Estimating the surface area of birds: using the homing pigeon (Columba livia) as a model.

PubMed

Perez, Cristina R; Moye, John K; Pritsos, Chris A

2014-05-08

Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird. © 2014. Published by The Company of Biologists Ltd | Biology Open.

Nonlinear optical probe of biopolymer adsorption on colloidal particle surface: poly-L-lysine on polystyrene sulfate microspheres.

PubMed

Eckenrode, Heather M; Dai, Hai-Lung

2004-10-12

A nonlinear optical technique--second harmonic generation (SHG)--has been applied to characterize the adsorption of poly-L-lysine on micrometer size polystyrene particles, whose surface is covered with negatively charged sulfonate groups, in aqueous solutions. Adsorption behavior of the biopolymer with two chain lengths (14 and 75 amino acid units; PL14 and PL75) has been examined. Centrifugation experiments were also performed to support the adsorption measurements made using SHG. The adsorption free energies of the two polymers PL75 and PL14 are determined as -16.57 and -14.40 kcal/mol, respectively. The small difference in the adsorption free energies of the two chain lengths, however, leads to dramatic difference in the concentration needed for saturated surface coverage: nearly 50 times higher concentration is needed for the smaller polymer. Under acidic colloidal conditions, polylysine is found to adsorb in a relatively flat conformation on the surface. The surface area that each polylysine molecule occupies is nearly 1 order of magnitude larger than the size of the molecule in its extended form. The low adsorption density is likely a result from Coulombic repulsion between the positive charges on the amino acid units of PL. The measurements demonstrate the utility of SHG as an efficient and sensitive experimental approach for measuring adsorption characteristics of bio/macromolecules on colloidal particles and define surface and colloidal conditions for achieving maximum surface coverage of a widely used biopolymer. Copyright 2004 American Chemical Society

Measuring the specific surface area of natural and manmade glasses: effects of formation process, morphology, and particle size

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

Papelis, Charalambos; Um, Wooyong; Russel, Charles E.

2003-03-28

The specific surface area of natural and manmade solid materials is a key parameter controlling important interfacial processes in natural environments and engineered systems, including dissolution reactions and sorption processes at solid-fluid interfaces. To improve our ability to quantify the release of trace elements trapped in natural glasses, the release of hazardous compounds trapped in manmade glasses, or the release of radionuclides from nuclear melt glass, we measured the specific surface area of natural and manmade glasses as a function of particle size, morphology, and composition. Volcanic ash, volcanic tuff, tektites, obsidian glass, and in situ vitrified rock were analyzed.more » Specific surface area estimates were obtained using krypton as gas adsorbent and the BET model. The range of surface areas measured exceeded three orders of magnitude. A tektite sample had the highest surface area (1.65 m2/g), while one of the samples of in situ vitrified rock had the lowest surf ace area (0.0016 m2/g). The specific surface area of the samples was a function of particle size, decreasing with increasing particle size. Different types of materials, however, showed variable dependence on particle size, and could be assigned to one of three distinct groups: (1) samples with low surface area dependence on particle size and surface areas approximately two orders of magnitude higher than the surface area of smooth spheres of equivalent size. The specific surface area of these materials was attributed mostly to internal porosity and surface roughness. (2) samples that showed a trend of decreasing surface area dependence on particle size as the particle size increased. The minimum specific surface area of these materials was between 0.1 and 0.01 m2/g and was also attributed to internal porosity and surface roughness. (3) samples whose surface area showed a monotonic decrease with increasing particle size, never reaching an ultimate surface area limit within the particle size range examined. The surface area results were consistent with particle morphology, examined by scanning electron microscopy, and have significant implications for the release of radionuclides and toxic metals in the environment.« less

Hydrologic and geochemical data for the Big Brown lignite mine area, Freestone County, Texas

USGS Publications Warehouse

Dorsey, Michael E.

1985-01-01

Lignite mining in east and east-central Texas is increasing in response to increased energy needs throughout the State. Associated with the increase in mining activities is a greater need to know the effects of mining activities on the water quantity and quality of near-surface aquifers. The near-surface lignite beds mined at the Big Brown Lignite Mine are from the Calvert Bluff Formation of the Wilcox Group of Eocene age, which is a minor aquifer generally having water suitable for all uses, in eastern Freestone County, Texas. One of the potential hydro!ogic effects of surface-coal mining is a change in the quality of ground water associated with replacement of aquifer materials by mine spoils. The purpose of this report is to compile and categorize geologic, mineralogic, geochemical, and hydrologic data for the Big Brown Lignite Mine and surrounding area in east-central Texas. Included are results of pasteextract analyses, constituent concentrations in water from batch-mixing experiments, sulfur analyses, and minerals or mineral groups detected by X-ray diffraction in 12 spoil material samples collected from 3 locations at the mine site. Also, common-constituent and trace-constituent concentrations in water from eight selected wells, located updip and downdip from the mine, are presented. Dissolved-solids concentrations in water from batch-mixing experiments vary from 12 to 908 milligrams per liter. Water from selected wells contain dissolved-solids concentrations ranging from 75 to 510 milligrams per liter.

Near-station terrain corrections for gravity data by a surface-integral technique

USGS Publications Warehouse

Gettings, M.E.

1982-01-01

A new method of computing gravity terrain corrections by use of a digitizer and digital computer can result in substantial savings in the time and manual labor required to perform such corrections by conventional manual ring-chart techniques. The method is typically applied to estimate terrain effects for topography near the station, for example within 3 km of the station, although it has been used successfully to a radius of 15 km to estimate corrections in areas where topographic mapping is poor. Points (about 20) that define topographic maxima, minima, and changes in the slope gradient are picked on the topographic map, within the desired radius of correction about the station. Particular attention must be paid to the area immediately surrounding the station to ensure a good topographic representation. The horizontal and vertical coordinates of these points are entered into the computer, usually by means of a digitizer. The computer then fits a multiquadric surface to the input points to form an analytic representation of the surface. By means of the divergence theorem, the gravity effect of an interior closed solid can be expressed as a surface integral, and the terrain correction is calculated by numerical evaluation of the integral over the surfaces of a cylinder, The vertical sides of which are at the correction radius about the station, the flat bottom surface at the topographic minimum, and the upper surface given by the multiquadric equation. The method has been tested with favorable results against models for which an exact result is available and against manually computed field-station locations in areas of rugged topography. By increasing the number of points defining the topographic surface, any desired degree of accuracy can be obtained. The method is more objective than manual ring-chart techniques because no average compartment elevations need be estimated ?

Use of iodine surface geochemical surveys in the Lodgepole and Minnelusa plays, U.S. northern Rockies

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

Tedesco, S.A.; Bretz, S.

1995-06-05

The use of surface geochemistry is becoming more prevalent in oil exploration, especially for focusing specific target areas for 2D and 3D seismic surveys. Presented here are two surface geochemical surveys utilizing the iodine method in delineating Upper Minnelusa sands of Permian age in the Powder River basin and Lodgepole Waulsortian-like mounds of Mississippian age in the Williston basin. Iodine is an indirect indicator of a petroleum accumulation at depth. Increases in iodine anomalies are caused by the presence of petroleum seepage in the upper part of the soil section. In the very shallow surface, less than 10 ft, amore » reaction occurs between hydrocarbons and iodine under sunlight forming inorganic compounds. The source of the iodine is either from minerals in the soil and/or from the atmosphere with ultraviolet light as the initiator of the reaction. Any iodine in the subsurface could not migrate far in the presence of hydrocarbons and due to its large molecular size. The compounds that form in the soil remain solid and are relatively difficult to remove. Any surface geochemical anomaly needs to be followed by seismic in order to provide a specific drilling target. If a surface geochemical survey is properly designed and implemented, when no anomaly is present, then to date regardless of the type of method used the results have been dry holes. If a surface geochemical anomaly is present, the intensity, areal extent, and quality of the anomaly cannot determine the economic viability of the accumulation of depth, but there is a significant increase in the success rate. The best utilization of these methods is to determine areas where there is no possibility of finding petroleum and focusing on areas that do. In the case of the Lodgepole and Minnelusa plays, surface geochemistry allows a low cost approach and helps focus and minimize 2D and 3D survey costs.« less

Nanosecond multi-pulse laser milling for certain area removal of metal coating on plastics surface

NASA Astrophysics Data System (ADS)

Zhao, Kai; Jia, Zhenyuan; Ma, Jianwei; Liu, Wei; Wang, Ling

2014-12-01

Metal coating with functional pattern on engineering plastics surface plays an important role in industry applications; it can be obtained by adding or removing certain area of metal coating on engineering plastics surface. However, the manufacturing requirements are improved continuously and the plastic substrate presents three-dimensional (3D) structure-many of these parts cannot be fabricated by conventional processing methods, and a new manufacturing method is urgently needed. As the laser-processing technology has many advantages like high machining accuracy and constraints free substrate structure, the machining of the parts is studied through removing certain area of metal coating based on the nanosecond multi-pulse laser milling. To improve the edge quality of the functional pattern, generation mechanism and corresponding avoidance strategy of the processing defects are studied. Additionally, a prediction model for the laser ablation depth is proposed, which can effectively avoid the existence of residual metal coating and reduces the damage of substrate. With the optimal machining parameters, an equiangular spiral pattern on copper-clad polyimide (CCPI) is machined based on the laser milling at last. The experimental results indicate that the edge of the pattern is smooth and consistent, the substrate is flat and without damage. The achievements in this study could be applied in industrial production.

Carrier effects on tertiary nitrifying moving bed biofilm reactor: An examination of performance, biofilm and biologically produced solids.

PubMed

Forrest, Daina; Delatolla, Robert; Kennedy, Kevin

2016-01-01

Increasingly stricter ammonia and nitrogen release regulations with respect to wastewater effluents are creating a need for tertiary treatment systems. The moving bed biofilm reactor (MBBR) is being considered as an upgrade option for an increasing number of wastewater treatment facilities due to its small footprint and ease of operation. Despite the MBBRs creation as a system to remove nitrogen, recent research on MBBR systems showing that the system's performance is directly related to carrier surface area and is irrespective of carrier shape and type has been performed exclusively on chemical oxygen demand (COD) removal systems. Furthermore, the influence of carrier type on the solids produced by MBBR systems has also been exclusively studied for COD removal systems. This work investigates the effects of three specific carrier types on ammonia removal rates, biofilm morphology, along with solids production and settleability of tertiary nitrifying MBBR systems. The study concludes that carrier type has no significant effect on tertiary nitrifying MBBR system performance under steady, moderate loading conditions. The research does however highlight the propensity of greater surface area to volume carriers to become clogged under high loading conditions and that the high surface area carriers investigated in this study required longer adjustment periods to changes in loading after becoming clogged.

Using Landsat Surface Reflectance Data as a Reference Target for Multiswath Hyperspectral Data Collected Over Mixed Agricultural Rangeland Areas

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

McCann, Cooper; Repasky, Kevin S.; Morin, Mikindra

Low-cost flight-based hyperspectral imaging systems have the potential to provide important information for ecosystem and environmental studies as well as aide in land management. To realize this potential, methods must be developed to provide large-area surface reflectance data allowing for temporal data sets at the mesoscale. This paper describes a bootstrap method of producing a large-area, radiometrically referenced hyperspectral data set using the Landsat surface reflectance (LaSRC) data product as a reference target. The bootstrap method uses standard hyperspectral processing techniques that are extended to remove uneven illumination conditions between flight passes, allowing for radiometrically self-consistent data after mosaicking. Throughmore » selective spectral and spatial resampling, LaSRC data are used as a radiometric reference target. Advantages of the bootstrap method include the need for minimal site access, no ancillary instrumentation, and automated data processing. Data from two hyperspectral flights over the same managed agricultural and unmanaged range land covering approximately 5.8 km 2 acquired on June 21, 2014 and June 24, 2015 are presented. As a result, data from a flight over agricultural land collected on June 6, 2016 are compared with concurrently collected ground-based reflectance spectra as a means of validation.« less

Using Landsat Surface Reflectance Data as a Reference Target for Multiswath Hyperspectral Data Collected Over Mixed Agricultural Rangeland Areas

DOE PAGES

McCann, Cooper; Repasky, Kevin S.; Morin, Mikindra; ...

2017-07-25

Low-cost flight-based hyperspectral imaging systems have the potential to provide important information for ecosystem and environmental studies as well as aide in land management. To realize this potential, methods must be developed to provide large-area surface reflectance data allowing for temporal data sets at the mesoscale. This paper describes a bootstrap method of producing a large-area, radiometrically referenced hyperspectral data set using the Landsat surface reflectance (LaSRC) data product as a reference target. The bootstrap method uses standard hyperspectral processing techniques that are extended to remove uneven illumination conditions between flight passes, allowing for radiometrically self-consistent data after mosaicking. Throughmore » selective spectral and spatial resampling, LaSRC data are used as a radiometric reference target. Advantages of the bootstrap method include the need for minimal site access, no ancillary instrumentation, and automated data processing. Data from two hyperspectral flights over the same managed agricultural and unmanaged range land covering approximately 5.8 km 2 acquired on June 21, 2014 and June 24, 2015 are presented. As a result, data from a flight over agricultural land collected on June 6, 2016 are compared with concurrently collected ground-based reflectance spectra as a means of validation.« less

A technique for sampling low shrub vegetation, by crown volume classes

Treesearch

Jay R. Bentley; Donald W. Seegrist; David A. Blakeman

1970-01-01

The effects of herbicides or other cultural treatments of low shrubs can be sampled by a new technique using crown volume as the key variable. Low shrubs were grouped in 12 crown volume classes with index values based on height times surface area of crown. The number of plants, by species, in each class is counted on quadrats. Many quadrats are needed for highly...

Preliminary Design Guide for Arctic Equipment

DTIC Science & Technology

1989-05-01

areas that need to be addressed. The components of the various assemblies that Metals , plastics and elastomers make up the subject piece of equipment...polyester elastomer . Allow sufficient length for contraction (- 10- in./in, per IF). Do not allow long, unsup- ported lengths of hose . Lubricants Viscosity...this compressed air cools upon several manufacturers offer teflon hoses with expansion and contact with a cold surface, the braided stainless steel

Summary of the NASA Science Instrument, Observatories and Sensor Systems (SIOSS) Technology Assessment Roadmap

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2011-01-01

In August 2010, the NASA Office of Chief Technologist (OCT) commissioned an assessment of 15 different technology areas of importance to the future of NASA. Technology Assessment #8 (TA8) was Science Instruments, Observatories and Sensor Systems (SIOSS). SIOSS assessed the needs for optical technology ranging from detectors to lasers, x-ray mirrors to microwave antenna, in-situ spectrographs for on-surface planetary sample characterization to large space telescopes. This needs assessment looked across the entirety of NASA and not just the Science Mission Directorate. This paper summarizes the SIOSS findings and recommendations.

Coupled Surface and Groundwater Hydrological Modeling in a Changing Climate.

PubMed

Sridhar, Venkataramana; Billah, Mirza M; Hildreth, John W

2017-11-09

Many current watershed modeling efforts now incorporate surface water and groundwater for managing water resources since the exchanges between groundwater and surface water need a special focus considering the changing climate. The influence of groundwater dynamics on water and energy balance components is investigated in the Snake River Basin (SRB) by coupling the Variable Infiltration Capacity (VIC) and MODFLOW models (VIC-MF) for the period of 1986 through 2042. A 4.4% increase in base flows and a 10.3% decrease in peak flows are estimated by VIC-MF compared to the VIC model in SRB. The VIC-MF model shows significant improvement in the streamflow simulation (Nash-Sutcliffe efficiency [NSE] of 0.84) at King Hill, where the VIC model could not capture the effect of spring discharge in the streamflow simulation (NSE of -0.30); however, the streamflow estimates show an overall decreasing trend. Two climate scenarios representing median and high radiative-forcings such as representative concentration pathways 4.5 and 8.5 show an average increase in the water table elevations between 2.1 and 2.6 m (6.9 and 8.5 feet) through the year 2042. The spatial patterns of these exchanges show a higher groundwater elevation of 15 m (50 feet) in the downstream area and a lower elevation of up to 3 m (10 feet) in the upstream area. Broadly, this study supports results of previous work demonstrating that integrated assessment of groundwater-surface water enables stakeholders to balance pumping, recharge and base flow needs and to manage the watersheds that are subjected to human pressures more sustainably. © 2017, National Ground Water Association.

Method and system for optical figuring by imagewise heating of a solvent

DOEpatents

Rushford, Michael C.

2005-08-30

A method and system of imagewise etching the surface of a substrate, such as thin glass, in a parallel process. The substrate surface is placed in contact with an etchant solution which increases in etch rate with temperature. A local thermal gradient is then generated in each of a plurality of selected local regions of a boundary layer of the etchant solution to imagewise etch the substrate surface in a parallel process. In one embodiment, the local thermal gradient is a local heating gradient produced at selected addresses chosen from an indexed array of addresses. The activation of each of the selected addresses is independently controlled by a computer processor so as to imagewise etch the substrate surface at region-specific etch rates. Moreover, etching progress is preferably concurrently monitored in real time over the entire surface area by an interferometer so as to deterministically control the computer processor to image-wise figure the substrate surface where needed.

Influence of Layup and Curing on the Surface Accuracy in the Manufacturing of Carbon Fiber Reinforced Polymer (CFRP) Composite Space Mirrors

NASA Astrophysics Data System (ADS)

Yang, Zhiyong; Zhang, Jianbao; Xie, Yongjie; Zhang, Boming; Sun, Baogang; Guo, Hongjun

2017-12-01

Carbon fiber reinforced polymer, CFRP, composite materials have been used to fabricate space mirror. Usually the composite space mirror can completely replicate the high-precision surface of mould by replication process, but the actual surface accuracy of replicated space mirror is always reduced, still needed further study. We emphatically studied the error caused by layup and curing on the surface accuracy of space mirror through comparative experiments and analyses, the layup and curing influence factors include curing temperature, cooling rate of curing, method of prepreg lay-up, and area weight of fiber. Focusing on the four factors, we analyzed the error influence rule and put forward corresponding control measures to improve the surface figure of space mirror. For comparative analysis, six CFRP composite mirrors were fabricated and surface profile of mirrors were measured. Four guiding control measures were described here. Curing process of composite space mirror is our next focus.

Incorporating Rich Mesoporosity into a Ceria-Based Catalyst via Mechanochemistry

DOE PAGES

Zhan, Wangcheng; Yang, Shize; Zhang, Pengfei; ...

2017-08-15

Ceria-based materials possessing mesoporous structures afford higher activity than the corresponding bulk materials in CO oxidation and other catalytic applications, because of the wide pore channel and high surface area. The development of a direct, template-free, and scalable technology for directing porosity inside ceriabased materials is highly welcome. Here in this paper, a family of mesoporous transition-metaldoped ceria catalysts with specific surface areas up to 122 m 2 g -1 is constructed by mechanochemical grinding. No templates, additives, or solvents are needed in this process, while the mechanochemistry-mediated restructuring and the decomposing of the organic group led to plentiful mesopores.more » Interestingly, the copper species are evenly dispersed in the ceria matrix at the atomic scale, as observed in high resolution scanning transmission electron microscopy in high angle annular dark field. The copper-doped ceria materials show good activity in the CO oxidation.« less

Solid sorbents for removal of carbon dioxide from gas streams at low temperatures

DOEpatents

Sirwardane, Ranjani V.

2005-06-21

New low-cost CO.sub.2 sorbents are provided that can be used in large-scale gas-solid processes. A new method is provided for making these sorbents that involves treating substrates with an amine and/or an ether so that the amine and/or ether comprise at least 50 wt. percent of the sorbent. The sorbent acts by capturing compounds contained in gaseous fluids via chemisorption and/or physisorption between the unit layers of the substrate's lattice where the polar amine liquids and solids and/or polar ether liquids and solids are located. The method eliminates the need for high surface area supports and polymeric materials for the preparation of CO.sub.2 capture systems, and provides sorbents with absorption capabilities that are independent of the sorbents' surface areas. The sorbents can be regenerated by heating at temperatures in excess of 35.degree. C.

Objective Characterization of Snow Microstructure for Microwave Emission Modeling

NASA Technical Reports Server (NTRS)

Durand, Michael; Kim, Edward J.; Molotch, Noah P.; Margulis, Steven A.; Courville, Zoe; Malzler, Christian

2012-01-01

Passive microwave (PM) measurements are sensitive to the presence and quantity of snow, a fact that has long been used to monitor snowcover from space. In order to estimate total snow water equivalent (SWE) within PM footprints (on the order of approx 100 sq km), it is prerequisite to understand snow microwave emission at the point scale and how microwave radiation integrates spatially; the former is the topic of this paper. Snow microstructure is one of the fundamental controls on the propagation of microwave radiation through snow. Our goal in this study is to evaluate the prospects for driving the Microwave Emission Model of Layered Snowpacks with objective measurements of snow specific surface area to reproduce measured brightness temperatures when forced with objective measurements of snow specific surface area (S). This eliminates the need to treat the grain size as a free-fit parameter.

BOREAS Level-2 MAS Surface Reflectance and Temperature Images in BSQ Format

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Newcomer, Jeffrey (Editor); Lobitz, Brad; Spanner, Michael; Strub, Richard; Lobitz, Brad

2000-01-01

The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Aircraft Data Acquisition Program focused on providing the research teams with the remotely sensed aircraft data products they needed to compare and spatially extend point results. The MODIS Airborne Simulator (MAS) images, along with other remotely sensed data, were collected to provide spatially extensive information over the primary study areas. This information includes biophysical parameter maps such as surface reflectance and temperature. Collection of the MAS images occurred over the study areas during the 1994 field campaigns. The level-2 MAS data cover the dates of 21-Jul-1994, 24-Jul-1994, 04-Aug-1994, and 08-Aug-1994. The data are not geographically/geometrically corrected; however, files of relative X and Y coordinates for each image pixel were derived by using the C130 navigation data in a MAS scan model. The data are provided in binary image format files.

Report of the Working Group on Space/Lunar Tradeoffs

NASA Technical Reports Server (NTRS)

1992-01-01

The group discussed the advantages and disadvantages of five locations for an optical/infrared array: low-Earth orbit (LEO), Sun-synchronous Earth-orbit, geosynchronous orbit (GEO), Lagrangian points (L4 and L5), and the lunar surface. The factors affecting an array and our assessments of them are given and briefly discussed. In the discussions, two axioms are assumed: (1) Human expansion into space and to the Moon will occur; and (2) The Space Station will be constructed and operational. The major conclusion reached is that baselines of moderate size (greater than 300 m) are best done on the Moon and that large baselines (greater than 10 km) can be done only on the Moon. Three areas needing additional research were identified as follows. (1) Studies are needed on methods to steer long-baseline systems in orbit. This involves learning how to control free-flyers. It is not clear how the difficulty of control varies with orbital elevation. (2) More work is needed on the internal metrology of array systems, both orbital and lunar-surface systems.(3) We need to understand the radiation effects on detectors and electronics and learn how to mitigate them.

Quantifying surface water runoff from Wadi Arogut towards the Dead Sea

NASA Astrophysics Data System (ADS)

Geyer, Stefan; Khayat, Saed; Marei, Amer

2015-04-01

The surrounded area of the Dead Sea, especially the west side suffers from many hydrological problems. While the Dead Sea level drop considered a major problem that affect the quality of the surrounded freshwater resources, a lot of the surface water flood from the adjacent Wadi are lost through direct run off without any exploitation. Therefore, it is necessary to maintain a type of balance between surface water exploitation through the Wadi and at the same time allow a sufficient amount of flow to the Dead Sea to ensure its sustainability. In this study, we choose one of the larger tributaries in the western side of the Dead Sea basin. The stream was modelled for runoff response to different rainfall amount and climate conditions (dry, normal, and wet seasons) which were chosen from the rainy seasons in the previous 30 years. Finally, the amount of surface water contribution from each of the three seasons of the Dead Sea was quantified. The outcome of the model shows the results from the normal rainy season, which is frequently reoccurs and common in the region. The model data show that such events normally contribute with about 18-22 MCM annually to the Dead Sea. The problem is with the recurrence of dry season such as 2005/2006, by which the amount of the surface water decrease and consequently has adverse effect on the Dead Sea. However, the presence of less frequent thunder storm season such as that one in 1991/1992 has also a positive effect on the Dead Sea level. In the rainy season 1991/1992 there was a higher amount of rainfall over the study area that reaches around 155 MCM. Despite the presence of this high amount most of the recharge lost to the ground as groundwater recharge. The high amount of rain increases the amount of inundated surface water out of the Wadi banks and covers more surfaces all over the study area, which in role promote more water loss to the ground. That is why the total loss (rather than surface runoff) was much higher (77%). Moreover, 50% less precipitation in 2006 decrease the Dead Sea five metres within five years, and 60% 1992 increase of precipitation raise the water level two metre only for two to three next years. How can we balance the groundwater needs and the Dead Sea survival with those 40% surface water? By no mean: preventing the Dead Sea decline by increasing runoff will not only preventing the fresh water deterioration, but also it will be in the account of groundwater recharge in the surrounding aquifers of the Dead Sea. These conclusions suggest strongly the need of an integrated groundwater model, in order to quantify all scenarios.

Spatial-Temporal dynamics of surface water flooding and consequences for emergency services accessibility

NASA Astrophysics Data System (ADS)

Pattison, Ian; Green, Daniel; Yu, Dapeng; Bosher, Lee; Wilby, Rob; Yang, Lili; Ryley, Tim

2016-04-01

Urban areas are increasingly susceptible to surface water flooding, with more intense precipitation and intensification of land development. Flooding has both direct impacts i.e. locations inundated with water, and indirect impacts i.e. transport networks, utility e.g. electricity/water services etc. The direct areas flooded evolve in space through the event, and are predicted by standard inundation models. However, the wider indirect impacts and the spatial-temporal patterns are less constrained and it is these that are needed to manage the impacts in real-time. This paper focusses on the Category One responders of the Fire and Rescue and Ambulance Services in the City of Leicester, East Midlands, UK. Leicester is ranked 16th out of 4215 settlements at risk of surface water flooding in the UK based upon the population at risk (15,200 people) (DEFRA, 2009). The analysis undertaken involved overlaying the flood extent with the Integrated Transport Network (ITN) data within a GIS framework. Then a simple transport routing algorithm was used to predict the travel time from specific nodes representing ambulance or fire stations to different parts of the city. Flood magnitudes with 1:20, 1:100 and 1:1000 return periods have been investigated. Under a scenario of no flooding, 100% of the city is accessible by the six fire stations in the city. However, in the 1 in 20 year surface water flood event the peak inundation results in 66.5% being accessible in the 10 minute permitted time and 6% is totally inaccessible. This falls to 40% and 13% respectively for the 1 in 100 year event. Maps show the area of the city that are accessible by two or more stations within the permitted response time, which shows these areas are the most resilient to surface water flooding. However, it isn't just the peak water depths at every location which impacts accessibility within the city but the spatial-temporal patterns of the inundation. The areas within the 10 minute response time expand and contract through the event as the inundated area makes roads in different parts of the city inaccessible through the event. These maps also allow key access roads to be identified. Key stakeholders, within the City of Leicester, have highlighted the potential benefit of such dynamic accessibility maps for their multi-agency planning and response for surface water flooding.

GIS based optimal impervious surface map generation using various spatial data for urban nonpoint source management.

PubMed

Lee, Cholyoung; Kim, Kyehyun; Lee, Hyuk

2018-01-15

Impervious surfaces are mainly artificial structures such as rooftops, roads, and parking lots that are covered by impenetrable materials. These surfaces are becoming the major causes of nonpoint source (NPS) pollution in urban areas. The rapid progress of urban development is increasing the total amount of impervious surfaces and NPS pollution. Therefore, many cities worldwide have adopted a stormwater utility fee (SUF) that generates funds needed to manage NPS pollution. The amount of SUF is estimated based on the impervious ratio, which is calculated by dividing the total impervious surface area by the net area of an individual land parcel. Hence, in order to identify the exact impervious ratio, large-scale impervious surface maps (ISMs) are necessary. This study proposes and assesses various methods for generating large-scale ISMs for urban areas by using existing GIS data. Bupyeong-gu, a district in the city of Incheon, South Korea, was selected as the study area. Spatial data that were freely offered by national/local governments in S. Korea were collected. First, three types of ISMs were generated by using the land-cover map, digital topographic map, and orthophotographs, to validate three methods that had been proposed conceptually by Korea Environment Corporation. Then, to generate an ISM of higher accuracy, an integration method using all data was proposed. Error matrices were made and Kappa statistics were calculated to evaluate the accuracy. Overlay analyses were performed to examine the distribution of misclassified areas. From the results, the integration method delivered the highest accuracy (Kappa statistic of 0.99) compared to the three methods that use a single type of spatial data. However, a longer production time and higher cost were limiting factors. Among the three methods using a single type of data, the land-cover map showed the highest accuracy with a Kappa statistic of 0.91. Thus, it was judged that the mapping method using the land-cover map is more appropriate than the others. In conclusion, it is desirable to apply the integration method when generating the ISM with the highest accuracy. However, if time and cost are constrained, it would be effective to primarily use the land-cover map. Copyright © 2017 Elsevier Ltd. All rights reserved.

a Semi-Empirical Topographic Correction Model for Multi-Source Satellite Images

NASA Astrophysics Data System (ADS)

Xiao, Sa; Tian, Xinpeng; Liu, Qiang; Wen, Jianguang; Ma, Yushuang; Song, Zhenwei

2018-04-01

Topographic correction of surface reflectance in rugged terrain areas is the prerequisite for the quantitative application of remote sensing in mountainous areas. Physics-based radiative transfer model can be applied to correct the topographic effect and accurately retrieve the reflectance of the slope surface from high quality satellite image such as Landsat8 OLI. However, as more and more images data available from various of sensors, some times we can not get the accurate sensor calibration parameters and atmosphere conditions which are needed in the physics-based topographic correction model. This paper proposed a semi-empirical atmosphere and topographic corrction model for muti-source satellite images without accurate calibration parameters.Based on this model we can get the topographic corrected surface reflectance from DN data, and we tested and verified this model with image data from Chinese satellite HJ and GF. The result shows that the correlation factor was reduced almost 85 % for near infrared bands and the classification overall accuracy of classification increased 14 % after correction for HJ. The reflectance difference of slope face the sun and face away the sun have reduced after correction.

Temperature distribution of a water droplet moving on a heated super-hydrophobic surface under the icing condition

NASA Astrophysics Data System (ADS)

Yamazaki, Masafumi; Sumino, Yutaka; Morita, Katsuaki

2017-11-01

In the aviation industry, ice accretion on the airfoil has been a hazardous issue since it greatly declines the aerodynamic performance. Electric heaters and bleed air, which utilizes a part of gas emissions from engines, are used to prevent the icing. Nowadays, a new de-icing system combining electric heaters and super hydrophobic coatings have been developed to reduce the energy consumption. In the system, the heating temperature and the coating area need to be adjusted. Otherwise, the heater excessively consumes energy when it is set too high and when the coating area is not properly located, water droplets which are once dissolved possibly adhere again to the rear part of the airfoil as runback ice In order to deal with these problems, the physical phenomena of water droplets on the hydrophobic surface demand to be figured out. However, not many investigations focused on the behavior of droplets under the icing condition have been conducted. In this research, the temperature profiling of the rolling droplet on a heated super-hydrophobic surface is experimentally observed by the dual luminescent imaging.

Overview of physiological principles to support thermal balance and comfort of astronauts in open space and on planetary surfaces

NASA Astrophysics Data System (ADS)

Koscheyev, Victor S.; Coca, Aitor; Leon, Gloria R.

2007-02-01

Although specialists have attempted to improve the space suit to provide better protection in open space or on planetary surfaces, there has been a relative lack of attention to features of human thermoregulatory processes that influence comfort and therefore have an impact on the effectiveness of protective equipment. Our findings showed that different body tissues transfer heat in/out of the body in a different manner. There are also individual differences in thermal transfer through body areas with different proportions of tissues; therefore, data on the thermal profile of each astronaut needs to be used to estimate the optimal body areas for heat/cold transfer in and out of the body in an individually tailored cooling/warming garment. Principles for supporting thermal comfort in space were formulated based on a series of studies to evaluate the human body's response to uniform/nonuniform thermal conditions on the body surface. We conclude that future space suit design and comfort support of astronauts can be easier and more effective if these principles are incorporated.

Up Close and Personal

NASA Image and Video Library

2014-05-08

This image is one of the highest-resolution MDIS observations to date! Many craters of varying degradation states are visible, as well as gentle terrain undulations. Very short exposure times are needed to make these low-altitude observations while the spacecraft is moving quickly over the surface; thus the images are slightly noisier than typical MDIS images. This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week. Date acquired: March 15, 2014 Image Mission Elapsed Time (MET): 37173522 Image ID: 5936740 Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) Center Latitude: 71.91° Center Longitude: 232.7° E Resolution: 5 meters/pixel Scale: The image is approximately 8.3 km (5.2 mi.) across. Incidence Angle: 79.4° Emission Angle: 4.0° Phase Angle: 83.4° http://photojournal.jpl.nasa.gov/catalog/PIA18370

Preliminary appraisal of the geohydrologic aspects of drainage wells, Orlando area, central Florida

USGS Publications Warehouse

Kimrey, Joel O.

1978-01-01

The Floridan aquifer contains two highly transmissive cavernous zones in the Orlando area: an upper producing zone about 150-600 feet below land surface; and a lower producing zone about 1,100-1,500 feet below land surface. Natural head differences are downward and there is hydraulic connection between the two producing zones. Drainage wells are finished open-end into the upper producing zone and emplace surface waters directly into that zone by gravity. Quantitatively, their use constitutes an effective method of artificial recharge. Their negative aspects relate to the probably poor, but unknown, quality of the recharge water. Caution is suggested in drawing definite and final conclusions on the overall geohydrologic and environmental effects of drainage wells prior to the collection and interpretation of a considerable quantity of new data. Though few ground-water pollution problems have been documented to date, the potential for such pollution should be seriously considered in light of the prob-able continuing need to use drainage wells; the probable volumes and quality of water involved; and the hydraulic relations between the two producing zones.

Fast and precise large area metrology of micropattern detectors using laser distance sensors

NASA Astrophysics Data System (ADS)

Müller, R.; Biebel, O.; Hertenberger, R.; Lösel, P.; Schaile, O.

2016-07-01

Novel developments in micropattern detector technology require fast and precise methods to measure large area topologies in the order of a few square meters. Standard tactile coordinate measurement systems have resolutions better 10 μm, but suffer from relatively long measuring time of several hours for one cycle. Sensitive structures may be damaged when touched by the tactile sensor. We present a method using laser distance sensors. Such a device is able to scan surfaces fast without touching them. The presented device has the capability to measure semitransparent surfaces. The vertical translator to mount the sensor is able to move in sub-mm steps. Using this we are able to measure the position and height of copper on FR4 with an accuracy better than 10 μm. We report on the performance of the sensor scanning non-transparent as well as semi-transparent surfaces. This includes studies to minimize the measurement time without a loss in resolution. Our method to calibrate the measurement system will also be shown. This calibration is needed to reach a resolution better than 10 μm.

Key subsurface data help to refine Trinity aquifer hydrostratigraphic units, south-central Texas

USGS Publications Warehouse

Blome, Charles D.; Clark, Allan K.

2014-01-01

The geologic framework and hydrologic characteristics of aquifers are important components for studying the nation’s subsurface heterogeneity and predicting its hydraulic budgets. Detailed study of an aquifer’s subsurface hydrostratigraphy is needed to understand both its geologic and hydrologic frameworks. Surface hydrostratigraphic mapping can also help characterize the spatial distribution and hydraulic connectivity of an aquifer’s permeable zones. Advances in three-dimensional (3-D) mapping and modeling have also enabled geoscientists to visualize the spatial relations between the saturated and unsaturated lithologies. This detailed study of two borehole cores, collected in 2001 on the Camp Stanley Storage Activity (CSSA) area, provided the foundation for revising a number of hydrostratigraphic units representing the middle zone of the Trinity aquifer. The CSSA area is a restricted military facility that encompasses approximately 4,000 acres and is located in Boerne, Texas, northwest of the city of San Antonio. Studying both the surface and subsurface geology of the CSSA area are integral parts of a U.S. Geological Survey project funded through the National Cooperative Geologic Mapping Program. This modification of hydrostratigraphic units is being applied to all subsurface data used to construct a proposed 3-D EarthVision model of the CSSA area and areas to the south and west.

A New Vehicle for Planetary Surface Exploration: The Mars Tumbleweed

NASA Technical Reports Server (NTRS)

Antol, Jeffrey

2005-01-01

The surface of Mars is currently being explored with a combination of orbiting spacecraft, stationary landers and wheeled rovers. However, only a small portion of the Martian surface has undergone in-situ examination. Landing sites must be chosen to insure the safety of the vehicles (and human explorers) and provide the greatest opportunity for mission success. While wheeled rovers provide the ability to move beyond the landing sites, they are also limited in their ability to traverse rough terrain; therefore, many scientifically interesting sites are inaccessible by current vehicles. In order to access these sites, a capability is needed that can transport scientific instruments across varied Martian terrain. A new "rover" concept for exploring the Martian surface, known as the Mars Tumbleweed, will derive mobility through use of the surface winds on Mars, much like the Tumbleweed plant does here on Earth. Using the winds on Mars, a Tumbleweed rover could conceivably travel great distances and cover broad areas of the planetary surface. Tumbleweed vehicles would be designed to withstand repeated bouncing and rolling on the rock covered Martian surface and may be durable enough to explore areas on Mars such as gullies and canyons that are currently inaccessible by conventional rovers. Achieving Mars wind-driven mobility; however, is not a minor task. The density of the atmosphere on Mars is approximately 60-80 times less than that on Earth and wind speeds are typically around 2-5 m/s during the day, with periodic winds of 10 m/s to 20 m/s (in excess of 25 m/s during seasonal dust storms). However, because of the Martian atmosphere#s low density, even the strongest winds on Mars equate to only a gentle breeze on Earth. Tumbleweed rovers therefore need to be relatively large (4-6 m in diameter), very lightweight (10-20 kg), and equipped with lightweight, low-power instruments. This paper provides an overview of the Tumbleweed concept, presents several notional design concepts, mission scenarios, and highlights recent tests and analyses of Tumbleweed prototypes.

Fluctuating snow line altitudes in the Hunza basin (Karakoram) using Landsat OLI imagery

NASA Astrophysics Data System (ADS)

Racoviteanu, Adina; Rittger, Karl; Brodzik, Mary J.; Painter, Thomas H.; Armstrong, Richard

2016-04-01

Snowline altitudes (SLAs) on glacier surfaces are needed for separating snow and ice as input for melt models. When measured at the end of the ablation season, SLAs are used for inferring stable-state glacier equilibrium line altitudes (ELAs). Direct measurements of snowlines are rarely possible particularly in remote, high altitude glacierized terrain, but remote sensing data can be used to separate these snow and ice surfaces. Snow lines are commonly visible on optical satellite images acquired at the end of the ablation season if the images are contrasted enough, and are manually digitized on screen using various satellite band combinations for visual interpretation, which is a time-consuming, subjective process. Here we use Landsat OLI imagery at 30 m resolution to estimate glacier SLAs for a subset of the Hunza basin in the Upper Indus in the Karakoram. Clean glacier ice surfaces are delineated using a standardized semi-automated band ratio algorithm with image segmentation. Within the glacier surface, snow and ice are separated using supervised classification schemes based on regions of interest, and glacier SLAs are extracted on the basis of these areas. SLAs are compared with estimates from a new automated method that relies on fractional snow covered area rather than on band ratio algorithms for delineating clean glacier ice surfaces, and on grain size (instead of supervised classification) for separating snow from glacier ice on the glacier surface. The two methods produce comparable snow/ice outputs. The fSCA-derived glacierized areas are slightly larger than the band ratio estimates. Some of the additional area is the result of better detection in shadows from spectral mixture analysis (true positive) while the rest is shallow water, which is spectrally similar to snow/ice (false positive). On the glacier surface, a thresholding the snow grain size image (grain size > 500μm) results in similar glacier ice areas derived from the supervised classification, but there is noise (snow) on edges of dirty ice/ moraines at the glacier termini and around rock outcrops on the glacier surface. Neither of the two methods distinguishes the debris-covered ice, so these were mapped separately using a combination of topographic indices (slope, terrain curvature), along with remote sensing surface temperature and texture data. Using average elevation of snow and ice areas, we calculate an ELA of 5260 m for 2013. We construct yearly time series of the ELAs around the centerlines of selected glaciers in the Hunza for the period 2000 - 2014 using Landsat imagery. We explore spatial trends in glacier ELAs within the region, as well as relationships between ELA and topographic characteristics extracted on a glacier-by-glacier basis from a digital elevation model.

Does lake size matter? Combining morphology and process modeling to examine the contribution of lake classes to population-scale processes

USGS Publications Warehouse

Winslow, Luke A.; Read, Jordan S.; Hanson, Paul C.; Stanley, Emily H.

2014-01-01

With lake abundances in the thousands to millions, creating an intuitive understanding of the distribution of morphology and processes in lakes is challenging. To improve researchers’ understanding of large-scale lake processes, we developed a parsimonious mathematical model based on the Pareto distribution to describe the distribution of lake morphology (area, perimeter and volume). While debate continues over which mathematical representation best fits any one distribution of lake morphometric characteristics, we recognize the need for a simple, flexible model to advance understanding of how the interaction between morphometry and function dictates scaling across large populations of lakes. These models make clear the relative contribution of lakes to the total amount of lake surface area, volume, and perimeter. They also highlight the critical thresholds at which total perimeter, area and volume would be evenly distributed across lake size-classes have Pareto slopes of 0.63, 1 and 1.12, respectively. These models of morphology can be used in combination with models of process to create overarching “lake population” level models of process. To illustrate this potential, we combine the model of surface area distribution with a model of carbon mass accumulation rate. We found that even if smaller lakes contribute relatively less to total surface area than larger lakes, the increasing carbon accumulation rate with decreasing lake size is strong enough to bias the distribution of carbon mass accumulation towards smaller lakes. This analytical framework provides a relatively simple approach to upscaling morphology and process that is easily generalizable to other ecosystem processes.

Mapping and modeling the biogeochemical cycling of turf grasses in the United States.

PubMed

Milesi, Cristina; Running, Steven W; Elvidge, Christopher D; Dietz, John B; Tuttle, Benjamin T; Nemani, Ramakrishna R

2005-09-01

Turf grasses are ubiquitous in the urban landscape of the United States and are often associated with various types of environmental impacts, especially on water resources, yet there have been limited efforts to quantify their total surface and ecosystem functioning, such as their total impact on the continental water budget and potential net ecosystem exchange (NEE). In this study, relating turf grass area to an estimate of fractional impervious surface area, it was calculated that potentially 163,800 km2 (+/- 35,850 km2) of land are cultivated with turf grasses in the continental United States, an area three times larger than that of any irrigated crop. Using the Biome-BGC ecosystem process model, the growth of warm-season and cool-season turf grasses was modeled at a number of sites across the 48 conterminous states under different management scenarios, simulating potential carbon and water fluxes as if the entire turf surface was to be managed like a well-maintained lawn. The results indicate that well-watered and fertilized turf grasses act as a carbon sink. The potential NEE that could derive from the total surface potentially under turf (up to 17 Tg C/yr with the simulated scenarios) would require up to 695 to 900 liters of water per person per day, depending on the modeled water irrigation practices, suggesting that outdoor water conservation practices such as xeriscaping and irrigation with recycled waste-water may need to be extended as many municipalities continue to face increasing pressures on freshwater.

Water-resources data network evaluation for Monterey County, California; Phase 2, northern and coastal areas of Monterey County

USGS Publications Warehouse

Templin, W.E.; Smith, P.E.; DeBortoli, M.L.; Schluter, R.C.

1995-01-01

This report presents an evaluation of water- resources data-collection networks in the northern and coastal areas of Monterey County, California. This evaluation was done by the U.S. Geological Survey in cooperation with the Monterey County Flood Control and Water Conservation District to evaluate precipitation, surface water, and ground water monitoring networks. This report describes existing monitoring networks in the study areas and areas where possible additional data-collection is needed. During this study, 106 precipitation-quantity gages were identified, of which 84 were active; however, no precipitation-quality gages were identified in the study areas. The precipitaion-quantity gages were concentrated in the Monterey Peninsula and the northern part of the county. If the number of gages in these areas were reduced, coverage would still be adequate to meet most objectives; however, additional gages could improve coverage in the Tularcitos Creek basin and in the coastal areas south of Carmel to the county boundary. If collection of precipitation data were expanded to include monitoring precipitation quality, this expanded monitoring also could include monitoring precipitation for acid rain and pesticides. Eleven continuous streamflow-gaging stations were identified during this study, of which seven were active. To meet the objectives of the streamflow networks outlined in this report, the seven active stations would need to be continued, four stations would need to be reactivated, and an additional six streamflow-gaging stations would need to be added. Eleven stations that routinely were sampled for chemical constituents were identified in the study areas. Surface water in the lower Big Sur River basin was sampled annually for total coli- form and fecal coliform bacteria, and the Big Sur River was sampled monthly at 16 stations for these bacteria. Routine sampling for chemical constituents also was done in the Big Sur River basin. The Monterey County Flood Control and Water Conservation District maintained three networks in the study areas to measure ground-water levels: (1) the summer network, (2) the monthly network, and (3) the annual autumn network. The California American Water Company also did some ground-water-level monitoring in these areas. Well coverage for ground-water monitoring was dense in the seawater-intrusion area north of Moss Landing (possibly because of multiple overlying aquifers), but sparse in other parts of the study areas. During the study, 44 sections were identified as not monitored for ground-water levels. In an ideal ground-water-level network, wells would be evenly spaced, except where local conditions or correlations of wells make monitoring unnecessary. A total of 384 wells that monitor ground-water levels and/or ground-water quality were identified during this study. The Monterey County Flood Control and Water Conservation District sampled ground-water quality monthly during the irrigation season to monitor seawater intrusion. Once each year (during the summer), the wells in this network were monitored for chlorides, specific conductance, and nitrates. Additional samples were collected from each well once every 5 years for complete mineral analysis. The California Department of Health Services, the California American Water Company, the U.S. Army Health Service at Ford Ord, and the Monterey Peninsula Water Management District also monitored ground-water quality in wells in the study areas. Well coverage for the ground-water- quality networks was dense in the seawater- intrusion area north of Moss Landing, but sparse in the rest of the study areas. During this study, 54 sections were identified as not monitored for water quality.

PAHs behavior in surface water and groundwater of the Yellow River estuary: Evidence from isotopes and hydrochemistry.

PubMed

Li, Jing; Li, Fadong; Liu, Qiang

2017-07-01

Large-scale irrigation projects have impacted the regional surface-groundwater interactions in the North China Plain (NCP). Given this concern, the aim of this study is to evaluate levels of PAH pollution, identify the sources of the PAHs, analyze the influence of surface-groundwater interactions on PAH distribution, and propose urgent management strategies for PAHs in China's agricultural areas. PAH concentrations, hydrochemical indicators and stable isotopic compositions (δ 18 O and δ 2 H) were determined for surface water (SW) and groundwater (GW) samples. PAHs concentrations in surface water and groundwater varied from 11.84 to 393.12 ng/L and 8.51-402.84 ng/L, respectively, indicating mild pollution. The seasonal variations showed the following trend: PAHs in surface water at the low-water phase > PAHs in groundwater at the low-water phase > PAHs in surface water at the high-water phase > PAHs in groundwater at the high-water phase. Hydrochemical and δ 18 O value of most groundwater samples distributed between the Yellow River and seawater. The mean value of mixture ratio of the Yellow River water recharge to the groundwater was 65%, few anomalous sites can reach to 90%. Surface-groundwater interactions influence the spatial distribution of PAHs in the study area. In light of the ongoing serious pollution, management practices for source control, improved control technologies, and the construction of a monitoring network to warn of increased risk are urgently needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lp-dual affine surface area

NASA Astrophysics Data System (ADS)

Wei, Wang; Binwu, He

2008-12-01

According to the notion of Lp-affine surface area by Lutwak, in this paper, we introduce the concept of Lp-dual affine surface area. Further, we establish the affine isoperimetric inequality and the Blaschke-Santaló inequality for Lp-dual affine surface area. Besides, the dual Brunn-Minkowski inequality for Lp-dual affine surface area is presented.

The impact of conjunctive use of canal and tube well water in Lagar irrigated area, Pakistan

NASA Astrophysics Data System (ADS)

Kazmi, Syed Iftikhar; Ertsen, Maurits W.; Asi, Muhammad Rafique

Introduction of the large gravity irrigation system in the Indus Basin in the late 19th century without a drainage system resulted in a rising water table, which resulted in water logging and salinity problems over large areas. In order to cope with the salinity and water logging problem, the Pakistan government initiated installation of 10,000 tube wells in different areas. This not only resulted in the lowering of water table, but also supplemented irrigation. Resulting benefits from the irrigation opportunities motivated framers to install private tube wells. The Punjab area meets 40% of its irrigation needs from groundwater abstraction. Today, farmers apply both surface water flows and groundwater from tube wells, creating a pattern of private and public water control. Sustainable use of groundwater needs proper quantification of the resource and information on processes involved in its recharge and discharge. The field work in the Lagar irrigated area, discussed in this paper, show that within the general picture of conjunctive use of canal water and groundwater, there is a clear spatial pattern between upstream and downstream areas, with upstream areas depending much less on groundwater than downstream areas. The irrigation context in the study area proves to be highly complex, with water users having differential access to canal and tube well water, resulting in different responses of farmers with their irrigation strategies, which in turn affect the salinity and water balances on the fields.

Developing Integrated Remote Sensing and Geographical Information Sciences Procedures to Assess Impacts of Climate Variations on Spatio-Temporal Distribution of Mangroves

NASA Astrophysics Data System (ADS)

Qaisar, Maha

2016-07-01

Pakistan's periled treasures of mangroves require protection from devastating anthropogenic activities, which can only be achieved through the identification and management of this habitat. The primary objective of this study is to identify the potential habitat of mangroves along the coastline of Pakistan with the help of Remote Sensing (RS) and Geographical Information System (GIS) techniques. Once the mangroves were identified, species of mangroves need to be separated through Object Based Image Analysis (OBIA) which gave the area of mangroves and non mangroves sites. Later other parameters of Sea Surface Temperature, Sea Surface Salinity, chlorophyll-a along with altimetry data were used to assess the climatic variations on the spatio-temporal distribution of mangroves. Since mangroves provide economical, ecological, biological indication of Coastal Change or Sea Level Rise. Therefore, this provides a strong platform to assess the climatic variations which are posing negative impacts on the mangroves ecosystem. The results indicate that mangroves are present throughout along the coastline, proving that Pakistan is rich in these diverse ecosystems. Pakistan being at important geo strategic position can also benefit from its vast mangroves and other coastal resources such as coral reefs and fish varieties. Moreover, coastal zone management through involvement of the local community and establishment of Marine Protected Area (MPA) is the need of the hour to avoid deforestation of mangroves, which can prove to be deadly damaging for the fish populace since it provides habitats to various marine animals. However, the established relationship among SST, SSS, chlorophyll-a and altimetry data assisted to know the suitable sites for mangroves. But due to enhanced climatic impacts these relationships are distorted which has posed devastating effects on the growth and distribution of mangroves. Study area was Karachi Coast, Pakistan. The total area of Karachi is about 70 km long with vital importance of ecological, economical and biological indication of sea level rise. The desktop work was started with the acquisition of Landsat 8 image then pre-processing was applied, that includes stacking of bands, digitizing of study area and latterly sub setting of this area. Now spectral indices were applied to enhance water and vegetation. Normalized Difference Vegetative Index (NDVI) and Normalized Difference Water Index (NDWI) were calculated. Object Based Image Analysis (OBIA) was performed on land covers to get the land cover maps. However, other parameters of SST, chlorophyll-a of the study area were also estimated using MODIS products to establish the relationship for ascertaining the mangroves growth and distribution. Whereas, sea level in relation with mangroves has a substantial correlation i.e. when the sea level is not changing relative to the mangrove surface, mangrove position remains generally stable. Whereas, if the sea level is falling relative to the mangrove surface, mangrove margins migrate seaward and possibly laterally if these areas adjacent to the mangrove develop conditions suitable for mangrove establishment. Moreover, if sea-level is rising relative to the elevation of the mangrove sediment surface, the mangrove's seaward and landward margins retreat landward as the mangrove species maintain their preferred hydro period. The mangrove may also expand laterally into areas of higher elevation. Therefore, the study of altimetry provides a milestone in the spatio-temporal growth and distribution of mangrove. Thus, this established study can help coastal related agencies to work more efficiently in the field of research and even for the welfare of the coastal community so that the risk of climate variability on the mangrove ecosystem can be minimized.

Global Land Product Validation Protocols: An Initiative of the CEOS Working Group on Calibration and Validation to Evaluate Satellite-derived Essential Climate Variables

NASA Astrophysics Data System (ADS)

Guillevic, P. C.; Nickeson, J. E.; Roman, M. O.; camacho De Coca, F.; Wang, Z.; Schaepman-Strub, G.

2016-12-01

The Global Climate Observing System (GCOS) has specified the need to systematically produce and validate Essential Climate Variables (ECVs). The Committee on Earth Observation Satellites (CEOS) Working Group on Calibration and Validation (WGCV) and in particular its subgroup on Land Product Validation (LPV) is playing a key coordination role leveraging the international expertise required to address actions related to the validation of global land ECVs. The primary objective of the LPV subgroup is to set standards for validation methods and reporting in order to provide traceable and reliable uncertainty estimates for scientists and stakeholders. The Subgroup is comprised of 9 focus areas that encompass 10 land surface variables. The activities of each focus area are coordinated by two international co-leads and currently include leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FAPAR), vegetation phenology, surface albedo, fire disturbance, snow cover, land cover and land use change, soil moisture, land surface temperature (LST) and emissivity. Recent additions to the focus areas include vegetation indices and biomass. The development of best practice validation protocols is a core activity of CEOS LPV with the objective to standardize the evaluation of land surface products. LPV has identified four validation levels corresponding to increasing spatial and temporal representativeness of reference samples used to perform validation. Best practice validation protocols (1) provide the definition of variables, ancillary information and uncertainty metrics, (2) describe available data sources and methods to establish reference validation datasets with SI traceability, and (3) describe evaluation methods and reporting. An overview on validation best practice components will be presented based on the LAI and LST protocol efforts to date.

Optical metrology at the Optical Sciences Center: an historical review

NASA Astrophysics Data System (ADS)

Creath, Katherine; Parks, Robert E.

2014-10-01

The Optical Sciences Center (OSC) begun as a graduate-level applied optics teaching institution to support the US space effort. The making of optics representative of those used in other space programs was deemed essential. This led to the need for optical metrology: at first Hartmann tests, but almost immediately to interferometric tests using the newly invented HeNe laser. Not only were new types of interferometers needed, but the whole infrastructure that went with testing, fringe location methods, aberration removal software and contour map generation to aid the opticians during polishing needed to be developed. Over the last half century more rapid and precise methods of interferogram data reduction, surface roughness measurement, and methods of instrument calibration to separate errors from those in the optic have been pioneered at OSC. Other areas of research included null lens design and the writing of lens design software that led into the design of computer generated holograms for asphere testing. More recently work has been done on the reduction of speckle noise in interferograms, methods to test large convex aspheres, and a return to slope measuring tests to increase the dynamic range of the types of aspheric surfaces amenable to optical testing including free-form surfaces. This paper documents the history of the development of optical testing projects at OSC and highlights the contributions some of the individuals associated with new methods of testing and the infrastructure needed to support the testing. We conclude with comments about the future trends optical metrology.

Pseudo-Capacitors: SPPS Deposition and Electrochemical Analysis of α-MoO3 and Mo2N Coatings

NASA Astrophysics Data System (ADS)

Golozar, Mehdi; Chien, Ken; Lian, Keryn; Coyle, Thomas W.

2013-06-01

Solution precursor plasma spraying (SPPS) is a novel thermal spray process in which a solution precursor is injected into the high-temperature zone of a DC-arc plasma jet to allow solvent evaporation from the precursor droplets, solute precipitation, and precipitate pyrolysis prior to substrate impact. This investigation explored the potential of SPPS to fabricate α-MoO3 coatings with fine grain sizes, high porosity levels, and high surface area: characteristics needed for application as pseudo-capacitor electrodes. Since molybdenum nitride has shown a larger electrochemical stability window and higher specific area capacitance, the α-MoO3 deposits were subsequently converted into molybdenum nitride. A multistep heat-treatment procedure resulted in a topotactic phase-transformation mechanism, which retained the high surface area lath-shaped features of the original α-MoO3. The electrochemical behaviors of molybdenum oxide and molybdenum nitride deposits formed under different deposition conditions were studied using cyclic voltammetry to assess the influence of the resulting microstructure on the charge storage behavior and potential for use in pseudo-capacitors.

Plan of study of the hydrology of the Madison Limestone and associated rocks in Montana, Nebraska, North Dakota, South Dakota, and Wyoming

USGS Publications Warehouse

,

1975-01-01

A major part of the United States ' coal reserves is in the Fort Union coal region of the Northern Great Plains. Large-scale development of these reserves would place a heavy demand on the area 's limited water resources. Surface water is poorly distributed in time and space. Its use for coal development in parts of the area would require storage reservoirs and distribution systems, whereas in the rest of the area surface water is fully appropriated and its use would deprive present users of their supply. Preliminary studies by the U.S. Geological Survey and State agencies in Wyoming, Montana, and South Dakota indicate that the Madison Limestone and associated rocks might provide a significant percentage of the total water requirements for coal development. This report briefly summarized the present knowledge of the geohydrology of the Madison and associated rocks, identifies the need for additional data, and outlines a 5-year plan for a comprehensive study of the hydrology of these rocks. (Woodard-USGS)

Dispersion of inorganic contaminants in surface water in the vicinity of Potchefstroom

NASA Astrophysics Data System (ADS)

Manyatshe, A.; Fosso-Kankeu, E.; van der Berg, D.; Lemmer, N.; Waanders, F.; Tutu, H.

2017-08-01

Potchefstroom and the neighbouring cities rely mostly on the Mooi River and Vaal River for their water needs. These rivers flow through the gold mining areas and farms, and are therefore likely to be contaminated with substantial amounts of inorganic pollutants. Water was collected along the rivers network, streams, canals and dams in Potchefstroom and the vicinity. The samples were characterized for geochemical parameters, metals and anions concentrations. The results showed high concentrations of potentially toxic elements such as As (4.53 mg/L - 5.74 mg/L), Cd (0.25 mg/L - 0.7 mg/L), Pb (1.14 mg/L - 5.13 mg/L) and U (0.04 mg/L - 0.11 mg/L) which were predominantly found around the mining areas. Elevated concentrations of anions such SO42- and CN- were detected around mining areas while NO3- was dominant near farms. The relatively high levels of anions and metals in the surface water made it unfit for domestic or agricultural use. The study showed that contaminants in mining and agricultural facilities were potentially mobilised, thus impacting the nearby water systems.

Terrain Correction on the moving equal area cylindrical map projection of the surface of a reference ellipsoid

NASA Astrophysics Data System (ADS)

Ardalan, A.; Safari, A.; Grafarend, E.

2003-04-01

An operational algorithm for computing the ellipsoidal terrain correction based on application of closed form solution of the Newton integral in terms of Cartesian coordinates in the cylindrical equal area map projected surface of a reference ellipsoid has been developed. As the first step the mapping of the points on the surface of a reference ellipsoid onto the cylindrical equal area map projection of a cylinder tangent to a point on the surface of reference ellipsoid closely studied and the map projection formulas are computed. Ellipsoidal mass elements with various sizes on the surface of the reference ellipsoid is considered and the gravitational potential and the vector of gravitational intensity of these mass elements has been computed via the solution of Newton integral in terms of ellipsoidal coordinates. The geographical cross section areas of the selected ellipsoidal mass elements are transferred into cylindrical equal area map projection and based on the transformed area elements Cartesian mass elements with the same height as that of the ellipsoidal mass elements are constructed. Using the close form solution of the Newton integral in terms of Cartesian coordinates the potential of the Cartesian mass elements are computed and compared with the same results based on the application of the ellipsoidal Newton integral over the ellipsoidal mass elements. The results of the numerical computations show that difference between computed gravitational potential of the ellipsoidal mass elements and Cartesian mass element in the cylindrical equal area map projection is of the order of 1.6 × 10-8m^2/s^2 for a mass element with the cross section size of 10 km × 10 km and the height of 1000 m. For a 1 km × 1 km mass element with the same height, this difference is less than 1.5 × 10-4 m^2}/s^2. The results of the numerical computations indicate that a new method for computing the terrain correction based on the closed form solution of the Newton integral in terms of Cartesian coordinates and with accuracy of ellipsoidal terrain correction has been achieved! In this way one can enjoy the simplicity of the solution of the Newton integral in terms of Cartesian coordinates and at the same time the accuracy of the ellipsoidal terrain correction, which is needed for the modern theory of geoid computations.

Mercury Underpotential Deposition to Determine Iridium and Iridium Oxide Electrochemical Surface Areas

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

Alia, Shaun M.; Hurst, Katherine E.; Kocha, Shyam S.

Determining the surface areas of electrocatalysts is critical for separating the key properties of area-specific activity and electrochemical surface area from mass activity. Hydrogen underpotential deposition and carbon monoxide oxidation are typically used to evaluate iridium (Ir) surface areas, but are ineffective on oxides and can be sensitive to surface oxides formed on Ir metals. Mercury underpotential deposition is presented in this study as an alternative, able to produce reasonable surface areas on Ir and Ir oxide nanoparticles, and able to produce similar surface areas prior to and following characterization in oxygen evolution. Reliable electrochemical surface areas allow for comparativemore » studies of different catalyst types and the characterization of advanced oxygen evolution catalysts. Lastly, they also enable the study of catalyst degradation in durability testing, both areas of increasing importance within electrolysis and electrocatalysis.« less

Mercury Underpotential Deposition to Determine Iridium and Iridium Oxide Electrochemical Surface Areas

DOE PAGES

Alia, Shaun M.; Hurst, Katherine E.; Kocha, Shyam S.; ...

2016-06-02

Determining the surface areas of electrocatalysts is critical for separating the key properties of area-specific activity and electrochemical surface area from mass activity. Hydrogen underpotential deposition and carbon monoxide oxidation are typically used to evaluate iridium (Ir) surface areas, but are ineffective on oxides and can be sensitive to surface oxides formed on Ir metals. Mercury underpotential deposition is presented in this study as an alternative, able to produce reasonable surface areas on Ir and Ir oxide nanoparticles, and able to produce similar surface areas prior to and following characterization in oxygen evolution. Reliable electrochemical surface areas allow for comparativemore » studies of different catalyst types and the characterization of advanced oxygen evolution catalysts. Lastly, they also enable the study of catalyst degradation in durability testing, both areas of increasing importance within electrolysis and electrocatalysis.« less

Base-flow characteristics of streams in the Valley and Ridge, the Blue Ridge, and the Piedmont physiographic provinces of Virginia

USGS Publications Warehouse

Nelms, David L.; Harlow, George E.; Hayes, Donald C.

1997-01-01

Growth within the Valley and Ridge, Blue Ridge, and Piedmont physiographic provinces of Virginia has focused concern about allocation of surface-water flow and increased demands on the ground-water resources. Potential surface-water yield was determined from statistical analysis of base-flow characteristics of streams. Base-flow characteristics also may provide a relative indication of the potential ground-water yield for areas that lack sufficient specific capacity or will-yield data; however, other factors need to be considered, such as geologic structure, lithology, precipitation, relief, and the degree of hydraulic interconnection between the regolith and bedrock.

Regional Geochemical Results from Analyses of Stream-Water, Stream-Sediment, Soil, Soil-Water, Bedrock, and Vegetation Samples, Tangle Lakes District, Alaska

USGS Publications Warehouse

Wang, Bronwen; Gough, L.P.; Wanty, R.B.; Lee, G.K.; Vohden, James; O'Neill, J. M.; Kerin, L.J.

2008-01-01

We report chemical analyses of stream-water, stream-sediment, soil, soil-water, bedrock, and vegetation samples collected from the headwaters of the Delta River (Tangle Lakes District, Mount Hayes 1:250,000-scale quadrangle) in east-central Alaska for the period June 20-25, 2006. Additionally, we present mineralogic analyses of stream sediment, concentrated by panning. The study area includes the southwestward extent of the Bureau of Land Management (BLM) Delta River Mining District (Bittenbender and others, 2007), including parts of the Delta River Archeological District, and encompasses an area of about 500 km2(approximately bordered by the Denali Highway to the south, near Round Tangle Lake, northward to the foothills of the Alaska Range (fig. 1). The primary focus of this study was the chemical characterization of native materials, especially surface-water and sediment samples, of first-order streams from the headwaters of the Delta River. The impetus for this work was the need, expressed by the Alaska Department of Natural Resources (ADNR), for an inventory of geochemical and hydrogeochemical baseline information about the Delta River Mining District. This information is needed because of a major upturn in exploration, drilling, and general mineral-resources assessments in the region since the late 1990s. Currently, the study area, called the 'MAN Project' area is being explored by Pure Nickel, Inc. (http://www.purenickel.com/s/MAN_Alaska.asp), and includes both Cu-Au-Ag and Ni-Cu-PGE (Pt-Pd-Au-Ag) mining claims. Geochemical data on surface-water, stream-sediment, soil, soil-water, grayleaf willow (Salix glauca L.), and limited bedrock samples are provided along with the analytical methodologies used and panned-concentrate mineralogy. We are releasing the data at this time with only minimal interpretation.

Reconnaissance Study of the Hydrology of American Memorial Park, Island of Saipan, Commonwealth of the Northern Mariana Islands

USGS Publications Warehouse

Perreault, Jeff A.

2007-01-01

American Memorial Park, a unit of the National Park Service on the Island of Saipan, includes among its features a 27-acre estuarine system that has become a rarity within the Commonwealth of the Northern Mariana Islands. The estuarine system's mosaic of marshy areas interspersed with emergent wetlands and mixed wet forests provides critical habitat for various migratory and resident waterfowl, including two Federally listed endangered species: the Marianas gallinule (Gallinula chloropus guami) and the nightingale reed warbler (Acrocephalus luscinia). With sensitivity to the park's ecologic assets and the uncertainty associated with locally rapid urbanization, a need to better understand the hydrology of American Memorial Park was recognized. To address that need, a reconnaissance study of the park was undertaken during August and September 2005. The goals of the study were (1) to describe the occurrence and salinity of surface and ground water within the park; (2) to develop a hydrologic model of the park area of the island, with emphasis on the 27-acre estuarine system; and (3) to identify additional data needed to further develop this model. With regard to surface water, three freshwater inputs to the park's natural wetland are possible: direct rainfall, seaward-flowing ground water, and overland flow. Direct rainfall, which is an important source of freshwater to the wetland, commonly exceeds evapotranspiration both seasonally and per storm. The seaward flow of ground water is likely to be a source of freshwater to the wetland because ground water generally has an upward vertical component in the nearshore environment. Overland flow upgradient of the park could potentially contribute a significant input of freshwater during periods of intense rainfall, but roads that flank the park's perimeter act as a barrier to surficial inflows. During the reconnaissance, four discrete bodies, or zones, of surface water were observed within the park's natural wetland. Conductivity within these surface-water zones typically ranged from 1,540 to 4,370 microsiemens per centimeter (?S/cm) at 25?C, although values as low as 829 and as high as 8,750 ?S/cm were measured. As a result of these observations, the American Memorial Park wetland area meets the definition criteria of an estuarine system that is dominantly oligohaline. Conductivity was also measured in a constructed wetland that was built within the park to augment the storm-drainage infrastructure of the village of Garapan. Reverse-osmosis facilities, in operation at hotels adjacent to the park, have historically discharged highly saline wastewater into the storm-drainage system. This collective storm and wastewater flow is routed into the constructed wetland and from there into the ocean. The conductivity of water in the constructed wetland ranged from 45,000 to 62,500 ?S/cm, exceeding nominal seawater values by as much as 25 percent, with the highest conductivities recorded near discharging storm drains. With regard to ground water, the reconnaissance included installation of a ground-water-monitoring network. Data collected from this network identified the presence of freshwater underlying the park and indicated that surface water is directly connected to ground water in the natural wetland because the water levels of both surface water and ground water directly varied with the tide. Conductivities of ground-water samples from wells in the monitoring network indicated that ground-water salinity was geographically related: conductivities were lower (801-2,490 ?S/cm) in surficially dry areas, intermediate (6,090-9,180 ?S/cm) in natural-wetland areas, and higher (18,250-27,700 ?S/cm) in areas adjacent to the constructed wetland and its associated ocean-discharge channel. Synoptic water-level surveys were made to enhance understanding of the spatial expression of the water table; they were scheduled to overlap with peak and trough tidal signals to enable limited characteri

Water resources data for New Mexico, water year 1967; Part 1. surface water records

USGS Publications Warehouse

,

1968-01-01

an area whose boundaries coincided with those of certain natural drainage areas. The records in New Mexico were contained in Parts 7, 8, and 9 of that series. Beginning with the 1961 water year, streamflow records and related data have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports is limited and primarily for local needs. The records will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of conterminous United States will be further subdivided.

Strongly Enhanced THz Emission caused by Localized Surface Charges in Semiconducting Germanium Nanowires

PubMed Central

Lee, Woo-Jung; Ma, Jin Won; Bae, Jung Min; Jeong, Kwang-Sik; Cho, Mann-Ho; Kang, Chul; Wi, Jung-Sub

2013-01-01

A principal cause of THz emission in semiconductor nanostructures is deeply involved with geometry, which stimulates the utilization of indirect bandgap semiconductors for THz applications. To date, applications for optoelectronic devices, such as emitters and detectors, using THz radiation have focused only on direct bandgap materials. This paper reports the first observation of strongly enhanced THz emission from Germanium nanowires (Ge NWs). The origin of THz generation from Ge NWs can be interpreted using two terms: high photoexcited electron-hole carriers (Δn) and strong built-in electric field (Eb) at the wire surface based on the relation . The first is related to the extensive surface area needed to trigger an irradiated photon due to high aspect ratio. The second corresponds to the variation of Fermi-level determined by confined surface charges. Moreover, the carrier dynamics of optically excited electrons and holes give rise to phonon emission according to the THz region. PMID:23760467

Building Airport Surface HITL Simulation Capability

NASA Technical Reports Server (NTRS)

Chinn, Fay Cherie

2016-01-01

FutureFlight Central is a high fidelity, real-time simulator designed to study surface operations and automation. As an air traffic control tower simulator, FFC allows stakeholders such as the FAA, controllers, pilots, airports, and airlines to develop and test advanced surface and terminal area concepts and automation including NextGen and beyond automation concepts and tools. These technologies will improve the safety, capacity and environmental issues facing the National Airspace system. FFC also has extensive video streaming capabilities, which combined with the 3-D database capability makes the facility ideal for any research needing an immersive virtual and or video environment. FutureFlight Central allows human in the loop testing which accommodates human interactions and errors giving a more complete picture than fast time simulations. This presentation describes FFCs capabilities and the components necessary to build an airport surface human in the loop simulation capability.

Design of high strength polymer metal interfaces by laser microstructured surfaces

NASA Astrophysics Data System (ADS)

Steinert, P.; Dittes, A.; Schimmelpfennig, R.; Scharf, I.; Lampke, T.; Schubert, A.

2018-06-01

In the areas of automotive, aeronautics and civil structures, lightweight construction is a current and a future need. Thus, multi material design has rapidly grown in importance, especially hybrid materials based on fiber reinforced plastics and aluminum offer great potential. Therefore, mechanical interlocking is a convenient way of designing the interface. Laser structuring is already used to generate a variety of surface topographies leading to high bond strengths. This paper investigates different laser structures aiming on highest joint strengths for aluminum and glass fiber reinforced polyamide 6 interfaces. Self-organizing pin structures comprised by additional micro/nano features as well as drilled hole structures, both ranging on the micrometer range, are compared to corundum blasting as a standard method for surface conditioning. For the presented surface structures, thermal joining and ultrasonic assisted joining are regarded towards their potential for an optimum joint design.

Cutaneous exposure scenarios for engineered nanoparticles used in semiconductor fabrication: a preliminary investigation of workplace surface contamination.

PubMed

Shepard, Michele; Brenner, Sara

2014-01-01

Numerous studies are ongoing in the fields of nanotoxicology and exposure science; however, gaps remain in identifying and evaluating potential exposures from skin contact with engineered nanoparticles in occupational settings. The aim of this study was to identify potential cutaneous exposure scenarios at a workplace using engineered nanoparticles (alumina, ceria, amorphous silica) and evaluate the presence of these materials on workplace surfaces. Process review, workplace observations, and preliminary surface sampling were conducted using microvacuum and wipe sample collection methods and transmission electron microscopy with elemental analysis. Exposure scenarios were identified with potential for incidental contact. Nanoparticles of silica or silica and/or alumina agglomerates (or aggregates) were identified in surface samples from work areas where engineered nanoparticles were used or handled. Additional data are needed to evaluate occupational exposures from skin contact with engineered nanoparticles; precautionary measures should be used to minimize potential cutaneous exposures in the workplace.

Calculating landscape surface area from digital elevation models

Treesearch

Jeff S. Jenness

2004-01-01

There are many reasons to want to know the true surface area of the landscape, especially in landscape analysis and studies of wildlife habitat. Surface area provides a better estimate of the land area available to an animal than planimetric area, and the ratio of this surface area to planimetric area provides a useful measure of topographic roughness of the landscape...

Measuring and Mapping the Topography of the Florida Everglades for Ecosystem Restoration

USGS Publications Warehouse

Desmond, Gregory B.

2003-01-01

One of the major issues facing ecosystem restoration and management of the Greater Everglades is the availability and distribution of clean, fresh water. The South Florida ecosystem encompasses an area of approximately 28,000 square kilometers and supports a human population that exceeds 5 million and is continuing to grow. The natural systems of the Kissimmee-Okeechobee-Everglades watershed compete for water resources primarily with the region's human population and urbanization, and with the agricultural and tourism industries. Surface water flow modeling and ecological modeling studies are important means of providing scientific information needed for ecosystem restoration planning and modeling. Hydrologic and ecological models provide much-needed predictive capabilities for evaluating management options for parks, refuges, and land acquisition and for understanding the impacts of land management practices in surrounding areas. These models require various input data, including elevation data that very accurately define the topography of the Florida Everglades.

ERTS-1 Role in land management and planning in Minnesota

NASA Technical Reports Server (NTRS)

Sizer, J. E.; Brown, D. A.

1974-01-01

Research on applications of ERTS-1 imagery to land use has focused on evaluating the ability of ERTS-1 imagery to update and refine the detail of land use information in the Minnesota Land Management Information System. Work has been directed toward defining the capabilities of the ERTS-1 system to provide information about surface cover by identifying forest, water, and wetland resources; urban and agricultural development: and testing and evaluating data input and output procedures. As capabilities were developed, meetings were held with administrators and resource information users from various agencies of government to identify their information needs. A full scale systems test for several selected pilot areas in the state is nearly complete. Users have been identified for each test area and they have been instrumental in identifying data requirements and analysis needs for administrative purposes. Users have both rural and urban orientations and provide a basis for evaluation of the results.

Detecting geothermal anomalies and evaluating LST geothermal component by combining thermal remote sensing time series and land surface model data

USGS Publications Warehouse

Romaguera, Mireia; Vaughan, R. Greg; Ettema, J.; Izquierdo-Verdiguier, E.; Hecker, C. A.; van der Meer, F.D.

2018-01-01

This paper explores for the first time the possibilities to use two land surface temperature (LST) time series of different origins (geostationary Meteosat Second Generation satellite data and Noah land surface modelling, LSM), to detect geothermal anomalies and extract the geothermal component of LST, the LSTgt. We hypothesize that in geothermal areas the LSM time series will underestimate the LST as compared to the remote sensing data, since the former does not account for the geothermal component in its model.In order to extract LSTgt, two approaches of different nature (physical based and data mining) were developed and tested in an area of about 560 × 560 km2 centered at the Kenyan Rift. Pre-dawn data in the study area during the first 45 days of 2012 were analyzed.The results show consistent spatial and temporal LSTgt patterns between the two approaches, and systematic differences of about 2 K. A geothermal area map from surface studies was used to assess LSTgt inside and outside the geothermal boundaries. Spatial means were found to be higher inside the geothermal limits, as well as the relative frequency of occurrence of high LSTgt. Results further show that areas with strong topography can result in anomalously high LSTgt values (false positives), which suggests the need for a slope and aspect correction in the inputs to achieve realistic results in those areas. The uncertainty analysis indicates that large uncertainties of the input parameters may limit detection of LSTgt anomalies. To validate the approaches, higher spatial resolution images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data over the Olkaria geothermal field were used. An established method to estimate radiant geothermal flux was applied providing values between 9 and 24 W/m2 in the geothermal area, which coincides with the LSTgt flux rates obtained with the proposed approaches.The proposed approaches are a first step in estimating LSTgt at large spatial coverage from remote sensing and LSM data series, and provide an innovative framework for future improvements.

Coastal surface water suitability analysis for irrigation in Bangladesh

NASA Astrophysics Data System (ADS)

Mahtab, Mohammad Hossain; Zahid, Anwar

2018-03-01

Water with adequate quality and quantity is very important for irrigation to ensure the crop yields. Salinity is common problem in the coastal waters in Bangladesh. The intensity of salinity in the coastal zone in Bangladesh is not same. It fluctuates over the year. Sodium is another hazard which may hamper permeability and ultimately affects the fertility. It can reduce the crop yields. Although surface water is available in the coastal zone of Bangladesh, but its quality for irrigation needs to be monitored over the year. This paper will investigate the overall quality of coastal surface waters. Thirty-three water samples from different rivers were collected both in wet period (October-December) and in dry period (February-April). Different physical and chemical parameters are considered for investigation of the adequacy of water with respect to international irrigation water quality standards and Bangladesh standards. A comparison between the dry and wet period coastal surface water quality in Bangladesh will also be drawn here. The analysis shows that coastal surface water in Bangladesh is overall suitable for irrigation during wet period, while it needs treatment (which will increase the irrigation cost) for using for irrigation during dry period. Adaptation to this situation can improve the scenario. An integrated plan should be taken to increase the water storing capacity in the coastal area to harvest water during wet period.

On the influence of substrate morphology and surface area on phytofauna

USGS Publications Warehouse

Becerra-Munoz, S.; Schramm, H.L.

2007-01-01

The independent effects and interactions between substrate morphology and substrate surface area on invertebrate density or biomass colonizing artificial plant beds were assessed in a clear-water and a turbid playa lake in Castro County, Texas, USA. Total invertebrate density and biomass were consistently greater on filiform substrates than on laminar substrates with equivalent substrate surface areas. The relationship among treatments (substrates with different morphologies and surface areas) and response (invertebrate density or biomass) was assessed with equally spaced surface areas. Few statistically significant interactions between substrate morphology and surface area were detected, indicating that these factors were mostly independent from each other in their effect on colonizing invertebrates. Although infrequently, when substrate morphology and surface area were not independent, the effects of equally spaced changes in substrate surface area on the rate of change of phytofauna density or biomass per unit of substrate surface area were dependent upon substrate morphology. The absence of three-way interactions indicated that effects of substrate morphology and substrate area on phytofauna density or biomass were independent of environmental conditions outside and inside exclosures. ?? 2006 Springer Science+Business Media B.V.

Thermodynamic Versus Surface Area Control of Microbial Fe(III) Oxide Reduction Kinetics

NASA Astrophysics Data System (ADS)

Roden, E. E.

2003-12-01

Recent experimental studies of synthetic and natural Fe(III) oxide reduction permit development of conceptual and quantitative models of enzymatic Fe(III) oxide reduction at circumneutral pH that can be compared to and contrasted with established models of abiotic mineral dissolution. The findings collectively support a model for controls on enzymatic reduction that differs fundamentally from those applied to abiotic reductive dissolution as a result of two basic phenomena: (1) the relatively minor influence of oxide mineralogical and thermodynamic properties on surface area-normalized rates of enzymatic reduction compared to abiotic reductive dissolution; and (2) the major limitation which sorption and/or surface precipitation of biogenic Fe(II) on residual oxide and Fe(III)-reducing bacterial cell surfaces poses to enzymatic electron transfer in the presence of excess electron donor. Parallel studies with two major Fe(III)-reducing bacteria genera (Shewanella and Geobacter) lead to common conclusions regarding the importance of these phenomena in regulating the rate and long-term extent of Fe(III) oxide reduction. Although the extent to which these phenomena can be traced to underlying kinetic vs. thermodynamic effects cannot be resolved with current information, models in which rates of enzymatic reduction are limited kinetically by the abundance of "available" oxide surface sites (as controlled by oxide surface area and the abundance of surface-bound Fe(II)) provide an adequate macroscopic description of controls on the initial rate and long-term extent of oxide reduction. In some instances, thermodynamic limitation posed by the accumulation of aqueous reaction end-products (i.e. Fe(II) and alkalinity) must also be invoked to explain observed long-term patterns of reduction. In addition, the abundance of Fe(III)-reducing microorganisms plays an important role in governing rates of reduction and needs to be considered in models of Fe(III) reduction in nonsteady-state systems, e.g. subsurface environments in which Fe(III) reduction is stimulated by contamination with organics or for the purposes of metal/radionuclide bioremediation.

Joint Sensing/Sampling Optimization for Surface Drifting Mine Detection with High-Resolution Drift Model

DTIC Science & Technology

2012-09-01

as potential tools for large area detection coverage while being moderately inexpensive (Wettergren, Performance of Search via Track - Before - Detect for...via Track - Before - Detect for Distribute 34 Sensor Networks, 2008). These statements highlight three specific needs to further sensor network research...Bay hydrography. Journal of Marine Systems, 12, 221–236. Wettergren, T. A. (2008). Performance of search via track - before - detect for distributed

Bouncing Continents: Insights into the Physics of the Polar Regions of the Earth from the POLENET Project in the International Polar Year

ERIC Educational Resources Information Center

Reading, Anya M.

2008-01-01

When ice sheets melt, and reduce the load on the surface of the Earth, the land areas beneath them bounce back up. New, accurate observations are needed to investigate this uplift and its implications effectively. This article provides a topical starting point for investigating some applications of physics applied to the polar regions of the…

Manufacture of Cryoshroud Surfaces for Space Simulation Chambers

NASA Technical Reports Server (NTRS)

Ash, Gary S.

2008-01-01

Environmental test chambers for space applications use internal shrouds to simulate temperature conditions encountered in space. Shroud temperatures may range from +150 C to -253 C (20 K), and internal surfaces are coated with special high emissivity/absorptivity paints. To obtain temperature uniformity over large areas, detailed thermal design is required for placement of tubing for gaseous or liquid nitrogen and helium and other exotic heat exchange fluids. The recent increase in space simulation activity related to the James Webb Space Telescope has led to the design of new cryogenic shrouds to meet critical needs in instrument package testing. This paper will review the design and manufacturing of shroud surfaces for several of these programs, including fabrication methods and the selection and application of paints for simulation chambers.

Extreme ultraviolet reflector

DOEpatents

Newnam, Brian E.

1990-01-01

A multi-faceted mirror forms a retroreflector for a resonator loop in a free electron laser (FEL) operating in the XUV (.lambda.=10-100 nm). The number of facets is determined by the angle-of-incidence needed to obtain total external reflectance (TER) from the facet surface and the angle through which the FEL beam is to be turned. Angles-of-incidence greater than the angle for TER may be used to increase the area of the beam incident on the surface and reduce energy absorption density. Suitable surface films having TER in the 10-100 nm range may be formed from a variety of materials, including Al, single-crystal Si, Ag, and Rh. One of the facets is formed as an off-axis conic section to collimate the output beam with minimum astigmatism.

Subsidence from underground mining; environmental analysis and planning considerations

USGS Publications Warehouse

Lee, Fitzhugh T.; Abel, John F.

1983-01-01

Subsidence, a universal process that occurs in response to the voids created by extracting solids or liquids from beneath the Earth's surface, is controlled by many factors including mining methods, depth of extraction, thickness of deposit, and topography, as well as the in situ properties of the rock mass above the deposit. The impacts of subsidence are potentially severe in terms of damage to surface utility lines and structures, changes in surface-water and ground-water conditions, and effects on vegetation and animals. Although subsidence cannot be eliminated, it can be reduced or controlled in areas where deformation of the ground surface would produce dangerous or costly effects. Subsidence prediction is highly developed in Europe where there are comparatively uniform mining conditions and a long history of field measurements. Much of this mining has been carried out beneath crowded urban and industrial areas where accurate predictions have facilitated use of the surface and reduced undesirable impacts. Concerted efforts to understand subsidence processes in the United States are recent. Empirical methods of subsidence analysis and prediction based on local conditions seem better suited to the current state of knowledge of the varied geologic and topographic conditions in domestic coal mining regions than do theoretical/mathematical approaches. In order to develop broadly applicable subsidence prediction methods and models for the United States, more information is needed on magnitude and timing of ground movements and geologic properties.

Effects of Surface Albedo on Smoke Detection Through Geostationary Satellite Imagery in the Hazard Mapping System (HMS)

NASA Astrophysics Data System (ADS)

Salemi, A.; Ruminski, M. G.

2012-12-01

The Satellite Analysis Branch (SAB) of NOAA/NESDIS uses geostationary and polar orbiting satellite imagery to identify fires and smoke throughout the continental United States. The fires and smoke are analyzed daily on the Hazard Mapping System (HMS) and made available via the internet in various formats. Analysis of smoke plumes generated from wildfires, agricultural and prescribe burns is performed with single channel visible imagery primarily from NOAA's Geostationary Operational Environmental Satellite (GOES) animations. Identification of smoke in visible imagery is complicated by the presence of clouds, the viewing angle produced by the sun, smoke, satellite geometry, and the surface albedo of the ground below the smoke among other factors. This study investigates the role of surface albedo in smoke detection. LIght Detection And Ranging (LIDAR) instruments are capable of detecting smoke and other aerosols. Through the use of ground and space based LIDAR systems in areas of varying albedo a relationship between the subjective analyst drawn smoke plumes versus those detected by LIDAR is established. The ability to detect smoke over regions of higher albedo (brighter surface, such as grassland, scrub and desert) is diminished compared to regions of lower albedo (darker surface, such as forest and water). Users of the HMS smoke product need to be aware of this limitation in smoke detection in areas of higher albedo.

Study on evaluation of corrosion condition of reinforcing bar embedded concrete using infrared thermal imaging camera

NASA Astrophysics Data System (ADS)

Ruiko, Watanabe; Toshiaki, Mizobuchi

2017-04-01

Rapid aging of many concrete structures, which have been developed during rapid economic growth period in Japan, has become a serious problem for us these days. And thus, there is an urgent need to prolong their service life expectancies. For this purpose, the deterioration of reinforcing bars in the concrete structures should be detected quickly and correctly at the early stages. Nevertheless, conventional testing methods such as destructive and nondestructive testing have disadvantages: partial damages on concrete structures; difficulty with quantitative evaluation, etc. Many preceding studies have examined to estimate the deterioration of reinforcing bars based on the temperature of the concrete specimen surfaces. According to those papers, the differences in corrosion degree of reinforcing bars have a certain effect on the temperature of concrete specimen surfaces. In this study, firstly, the quantitative evaluation of the corrosion degree was conducted with 3D scanner which could measure the volume, coverage area and cross-sectional area. Secondly, the surface of the concrete specimen was cooled down with liquid nitrogen, and thirdly, thermographic change was observed up until the air temperature. Finally, the surface of the concrete specimen was detected clearly by the thermal images. As a result, this study shows that the corrosion thickness tends to get bigger, following the uprising temperature of the concrete specimen surfaces. The same kind of tendency can be observed by the thermal images, too.

Evaluation of Advanced Reactive Surface Area Estimates for Improved Prediction of Mineral Reaction Rates in Porous Media

NASA Astrophysics Data System (ADS)

Beckingham, L. E.; Mitnick, E. H.; Zhang, S.; Voltolini, M.; Yang, L.; Steefel, C. I.; Swift, A.; Cole, D. R.; Sheets, J.; Kneafsey, T. J.; Landrot, G.; Anovitz, L. M.; Mito, S.; Xue, Z.; Ajo Franklin, J. B.; DePaolo, D.

2015-12-01

CO2 sequestration in deep sedimentary formations is a promising means of reducing atmospheric CO2 emissions but the rate and extent of mineral trapping remains difficult to predict. Reactive transport models provide predictions of mineral trapping based on laboratory mineral reaction rates, which have been shown to have large discrepancies with field rates. This, in part, may be due to poor quantification of mineral reactive surface area in natural porous media. Common estimates of mineral reactive surface area are ad hoc and typically based on grain size, adjusted several orders of magnitude to account for surface roughness and reactivity. This results in orders of magnitude discrepancies in estimated surface areas that directly translate into orders of magnitude discrepancies in model predictions. Additionally, natural systems can be highly heterogeneous and contain abundant nano- and micro-porosity, which can limit connected porosity and access to mineral surfaces. In this study, mineral-specific accessible surface areas are computed for a sample from the reservoir formation at the Nagaoka pilot CO2 injection site (Japan). Accessible mineral surface areas are determined from a multi-scale image analysis including X-ray microCT, SEM QEMSCAN, XRD, SANS, and SEM-FIB. Powder and flow-through column laboratory experiments are performed and the evolution of solutes in the aqueous phase is tracked. Continuum-scale reactive transport models are used to evaluate the impact of reactive surface area on predictions of experimental reaction rates. Evaluated reactive surface areas include geometric and specific surface areas (eg. BET) in addition to their reactive-site weighted counterparts. The most accurate predictions of observed powder mineral dissolution rates were obtained through use of grain-size specific surface areas computed from a BET-based correlation. Effectively, this surface area reflects the grain-fluid contact area, or accessible surface area, in the powder dissolution experiment. In the model of the flow-through column experiment, the accessible mineral surface area, computed from the multi-scale image analysis, is evaluated in addition to the traditional surface area estimates.

Potential climatic impacts and reliability of very large-scale wind farms

NASA Astrophysics Data System (ADS)

Wang, C.; Prinn, R. G.

2010-02-01

Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG) emission technologies such as wind energy. The widespread availability of wind power has fueled substantial interest in this renewable energy source as one of the needed technologies. For very large-scale utilization of this resource, there are however potential environmental impacts, and also problems arising from its inherent intermittency, in addition to the present need to lower unit costs. To explore some of these issues, we use a three-dimensional climate model to simulate the potential climate effects associated with installation of wind-powered generators over vast areas of land or coastal ocean. Using wind turbines to meet 10% or more of global energy demand in 2100, could cause surface warming exceeding 1 °C over land installations. In contrast, surface cooling exceeding 1 °C is computed over ocean installations, but the validity of simulating the impacts of wind turbines by simply increasing the ocean surface drag needs further study. Significant warming or cooling remote from both the land and ocean installations, and alterations of the global distributions of rainfall and clouds also occur. These results are influenced by the competing effects of increases in roughness and decreases in wind speed on near-surface turbulent heat fluxes, the differing nature of land and ocean surface friction, and the dimensions of the installations parallel and perpendicular to the prevailing winds. These results are also dependent on the accuracy of the model used, and the realism of the methods applied to simulate wind turbines. Additional theory and new field observations will be required for their ultimate validation. Intermittency of wind power on daily, monthly and longer time scales as computed in these simulations and inferred from meteorological observations, poses a demand for one or more options to ensure reliability, including backup generation capacity, very long distance power transmission lines, and onsite energy storage, each with specific economic and/or technological challenges.

Potential climatic impacts and reliability of very large-scale wind farms

NASA Astrophysics Data System (ADS)

Wang, C.; Prinn, R. G.

2009-09-01

Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG) emission technologies such as wind energy. The widespread availability of wind power has fueled legitimate interest in this renewable energy source as one of the needed technologies. For very large-scale utilization of this resource, there are however potential environmental impacts, and also problems arising from its inherent intermittency, in addition to the present need to lower unit costs. To explore some of these issues, we use a three-dimensional climate model to simulate the potential climate effects associated with installation of wind-powered generators over vast areas of land or coastal ocean. Using wind turbines to meet 10% or more of global energy demand in 2100, could cause surface warming exceeding 1°C over land installations. In contrast, surface cooling exceeding 1°C is computed over ocean installations, but the validity of simulating the impacts of wind turbines by simply increasing the ocean surface drag needs further study. Significant warming or cooling remote from both the land and ocean installations, and alterations of the global distributions of rainfall and clouds also occur. These results are influenced by the competing effects of increases in roughness and decreases in wind speed on near-surface turbulent heat fluxes, the differing nature of land and ocean surface friction, and the dimensions of the installations parallel and perpendicular to the prevailing winds. These results are also dependent on the accuracy of the model used, and the realism of the methods applied to simulate wind turbines. Additional theory and new field observations will be required for their ultimate validation. Intermittency of wind power on daily, monthly and longer time scales as computed in these simulations and inferred from meteorological observations, poses a demand for one or more options to ensure reliability, including backup generation capacity, very long distance power transmission lines, and onsite energy storage, each with specific economic and/or technological challenges.

Using the 3D active fault model to estimate the surface deformation, a study on HsinChu area, Taiwan.

NASA Astrophysics Data System (ADS)

Lin, Y. K.; Ke, M. C.; Ke, S. S.

2016-12-01

An active fault is commonly considered to be active if they have moved one or more times in the last 10,000 years and likely to have another earthquake sometime in the future. The relationship between the fault reactivation and the surface deformation after the Chi-Chi earthquake (M=7.2) in 1999 has been concerned up to now. According to the investigations of well-known disastrous earthquakes in recent years, indicated that surface deformation is controlled by the 3D fault geometric shape. Because the surface deformation may cause dangerous damage to critical infrastructures, buildings, roads, power, water and gas lines etc. Therefore it's very important to make pre-disaster risk assessment via the 3D active fault model to decrease serious economic losses, people injuries and deaths caused by large earthquake. The approaches to build up the 3D active fault model can be categorized as (1) field investigation (2) digitized profile data and (3) build the 3D modeling. In this research, we tracked the location of the fault scarp in the field first, then combined the seismic profiles (had been balanced) and historical earthquake data to build the underground fault plane model by using SKUA-GOCAD program. Finally compared the results come from trishear model (written by Richard W. Allmendinger, 2012) and PFC-3D program (Itasca) and got the calculated range of the deformation area. By analysis of the surface deformation area made from Hsin-Chu Fault, we concluded the result the damage zone is approaching 68 286m, the magnitude is 6.43, the offset is 0.6m. base on that to estimate the population casualties, building damage by the M=6.43 earthquake in Hsin-Chu area, Taiwan. In the future, in order to be applied accurately on earthquake disaster prevention, we need to consider further the groundwater effect and the soil structure interaction inducing by faulting.

The role of surface water redistribution in an area of patterned vegetation in a semi-arid environment, south-west Niger

NASA Astrophysics Data System (ADS)

Bromley, J.; Brouwer, J.; Barker, A. P.; Gaze, S. R.; Valentine, C.

1997-11-01

The surface hydrology of a semi-arid area of patterned vegetation in south-west Niger is described. In this region alternating bands of vegetation and bare ground aligned along the contours of a gently sloping terrain give rise to a phenomenon known as `brousse tigrée' (tiger bush). At the selected study site the vegetation bands are 10-30 m wide, separated by 50-100-m-wide bands of bare ground. Five species of shrub dominate, Guiera senegalensis, Combretum micranthum, C. nigricans, Acacia ataxacantha and A. macrostachya. Herbaceous vegetation is generally limited to the upslope edges of vegetation bands. A comprehensive field programme was undertaken to investigate the hydrology. Topographic, vegetation and surface feature surveys were carried out in conjunction with the measurement of rainfall, surface and subsurface hydraulic conductivity, particle size and soil moisture content. Four types of vegetation class are recognised, each tending to occupy a constant position relative to the others and to the regional slope. In a downslope direction the classes are: bare ground, grassy open bush, closed bush, bare open bush, bare ground etc. The nature of the ground surface is closely linked to the vegetation class. Over the bare, bare open and grassy open classes various types of surface crust are present with each type of crust tending to occupy a constant position on the regional slope relative to the vegetation class and other crust types. Below closed bush crusts are generally absent. The typical downslope sequence from the downslope boundary of a vegetation band is: structural (sieving) crust→erosion crust→(gravel crust)→sedimentation crust→microphytic sedimentation crust→no crust→sieving crust, etc. It is also shown that these crust types are dynamic and evolve from one to the other as hydrological conditions change. Hydraulic conductivities of surface crusts are low, typically falling within the range 10 -6-10 -7 m s -1. The presence of large expanses of crust over bare regions tends to generate run-off, which moves down the regional slope to be intercepted and pond within and just upslope of vegetated areas. Such run-off concentrates rainfall by a factor of up to 3.7 below vegetated areas. This concentration combined with an absence of crust development in closed bush areas promotes rapid infiltration below and just upslope of vegetation bands. In this way the hydrology of the area operates to ensure that the bulk of the rain which falls is directed as quickly as possible to the areas where it is most needed to support the existing vegetation.

Mapping the articular contact area of the long head of the biceps tendon on the humeral head.

PubMed

Morris, Brent J; Byram, Ian R; Lathrop, Ray A; Dunn, Warren R; Kuhn, John E

2014-01-01

The purpose of this investigation was to calculate the contact surface area of the long head of the biceps (LHB) in neutral position and abduction. We sought to determine whether the LHB articulates with the humeral head in a consistent pattern comparing articular contact area in neutral position and abduction. Eleven fresh frozen matched cadaveric shoulders were analyzed. The path of the biceps tendon on the articular surface of the humeral head and the total articular surface were digitized using a MicronTracker 2 H3-60 three-dimensional optical tracker. Contact surface area was significantly less in abduction than in neutral position (P = 0.002) with a median ratio of 41% (36%, 47.5%). Ratios of contact area in neutral position to full articular surface area were consistent between left and right shoulders (rho = 1, P = 0.017) as were ratios of abduction area to full articular surface area (rho = 0.97, P = 0.005). The articular contact surface area is significantly greater in neutral position than abduction. The ratios of articular contact surface areas to total humeral articular surface areas have a narrow range and are consistent between left and right shoulders of the same cadaver.

Development of unbonded and bonded areas in relation to Populus species wood characteristics in grinding

Treesearch

L.K. Lehtonen; J.H. Lehto; A.W. Rudie

2004-01-01

In terms of fibre development in mechanical pulping, most of the energy is spent on the creation of specific surface area. The total surface area created can be divided into two categories: surface area that adds to the unbonded area (optical properties) and surface area that adds to the bonded area (strength properties) of mechanical papers. This paper considers these...

Poor neighborhoods: safe playgrounds.

PubMed

Powell, Elizabeth C; Ambardekar, Erin J; Sheehan, Karen M

2005-09-01

Although unstructured physical play is helpful to child development and physical activity is important to obesity prevention, up-to-date information about playgrounds and playground hazards in urban areas is limited. Local data are needed to identify problems and target interventions. The aim of this study was to describe the hazards in playgrounds located in low-income (median dollars 28,728-38,915) and very low-income (median dollars 18,266-18,955) Chicago neighborhoods. Using a standardized on-site survey (National Program for Playground Safety), two investigators reviewed seventy-eight public playgrounds for hazards related to playground design, safe surfaces, supervision, and equipment design and maintenance. The design of 56 playgrounds (72%) posed no hazards. One playground lacked protection from motor vehicles, and 21 had minor flaws. One playground had an asphalt surface; all others had protective surfaces, usually wood chips. The chips were too thin in many places, and in 15 playgrounds (19%), at least one concrete footing was exposed. Trash was a common surface hazard (68%). Although most equipment was safe (swings of soft materials and appropriate platform barriers), many pieces needed repairs. Equipment maintenance hazards included gaps (44%) and missing (38%) or broken parts (35%). In 13 of 39 playgrounds (33%) where children were observed playing, one or more were unsupervised. Playgrounds in very low-income neighborhoods more often had trash in the fall zone and exposed footings (P<.01 for each); there were no differences between low and very low-income neighborhoods in playground design or equipment maintenance. We conclude that playgrounds in low-income Chicago neighborhoods are of good design and have appropriate surfaces. Needed improvements include attention to wood chip depth, the removal of trash from the fall zone, and equipment repairs. Greater adult supervision is warranted.

Evaluating the Utility of Satellite Soil Moisture Retrievals over Irrigated Areas and the Ability of Land Data Assimilation Methods to Correct for Unmodeled Processes

NASA Technical Reports Server (NTRS)

Kumar, S. V.; Peters-Lidard, C. D.; Santanello, J. A.; Reichle, R. H.; Draper, C. S.; Koster, R. D.; Nearing, G.; Jasinski, M. F.

2015-01-01

Earth's land surface is characterized by tremendous natural heterogeneity and human-engineered modifications, both of which are challenging to represent in land surface models. Satellite remote sensing is often the most practical and effective method to observe the land surface over large geographical areas. Agricultural irrigation is an important human-induced modification to natural land surface processes, as it is pervasive across the world and because of its significant influence on the regional and global water budgets. In this article, irrigation is used as an example of a human-engineered, often unmodeled land surface process, and the utility of satellite soil moisture retrievals over irrigated areas in the continental US is examined. Such retrievals are based on passive or active microwave observations from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E), the Advanced Microwave Scanning Radiometer 2 (AMSR2), the Soil Moisture Ocean Salinity (SMOS) mission, WindSat and the Advanced Scatterometer (ASCAT). The analysis suggests that the skill of these retrievals for representing irrigation effects is mixed, with ASCAT-based products somewhat more skillful than SMOS and AMSR2 products. The article then examines the suitability of typical bias correction strategies in current land data assimilation systems when unmodeled processes dominate the bias between the model and the observations. Using a suite of synthetic experiments that includes bias correction strategies such as quantile mapping and trained forward modeling, it is demonstrated that the bias correction practices lead to the exclusion of the signals from unmodeled processes, if these processes are the major source of the biases. It is further shown that new methods are needed to preserve the observational information about unmodeled processes during data assimilation.

Effect of oxygen plasma treatment on the electrochemical performance of the rayon and polyacrylonitrile based carbon felt for the vanadium redox flow battery application

NASA Astrophysics Data System (ADS)

Dixon, D.; Babu, D. J.; Langner, J.; Bruns, M.; Pfaffmann, L.; Bhaskar, A.; Schneider, J. J.; Scheiba, F.; Ehrenberg, H.

2016-11-01

Oxygen plasma treatment was applied on commercially available graphite felt electrodes based on rayon (GFA) and polyacrylonitrile (GFD). The formation of functional groups on the surface of the felt was confirmed by X-ray photoelectron spectroscopy measurements. The BET studies of the plasma treated electrodes showed no significant increase in surface area for both the rayon as well as the PAN based felts. Both plasma treated electrodes showed significantly enhanced V3+/V2+ redox activity compared to the pristine electrodes. Since an increase of the surface area has been ruled out for plasma treated electrode the enhanced activity could be attributed to surface functional groups. Interestingly, plasma treated GFD felts showed less electrochemical activity towards V5+/V4+ compared to the pristine electrode. Nevertheless, an overall increase of the single cell performance was still observed as the negative electrode is known to be the performance limiting electrode. Thus, to a great extent the present work helps to preferentially understand the importance of functional groups on the electrochemical activity of negative and positive redox reaction. The study emphasizes the need of highly active electrodes especially at the negative electrode side as inactive electrodes can still facilitate hydrogen evolution and degrade the electrolyte in VRFBs.

Pre-clinical laboratory evaluation of the new 'AF' arterial line filter range.

PubMed

Yarham, Gemma; Mulholland, John

2010-07-01

The presence of emboli was recognised relatively early in the history of open heart surgery. The emboli produced during cardiopulmonary bypass have the predisposition to distribute into, and ultimately obstruct, microvessels of all tissues. The Sorin Group has recently developed a new range of arterial line filters. Before the Sorin AF range of filters was released for pre-launch clinical trials, our group performed in vitro laboratory testing of the AF range against a selection of commercially available filters on the global market. The Sorin AF620 and AF640 demonstrate both the smallest prime volume and smallest surface contact area (92ml and 290 cm(2), respectively).The results of the GME Handling Efficiency experiments ranged by 39.6%, from 95.9% to 56.3%. In terms of an air bolus handling, the results of the Limit Bolus experiment ranged by 97 ml, from 147.5 ml down to 50 ml. The pressure drop across all the filters was measured under steady state experimental conditions. All of the above investigations were considered against surface area and prime volume. It is clear from the results that some commercially available arterial line filters perform better than others, not only in overall performance, but also with regard to individual characteristics. Evaluating arterial line filters for hospital-specific use has to balance pressure drop, surface area, micro air handling, prime volume and gross air handling; all points need to be considered. In the AF620 and AF640, Sorin boast that they are the two smallest prime and smallest surface area filters commercially available on the global market. The Sorin AF filter range performs well in all of the areas we investigated and will be a competitive option for centres, irrespective of which characteristics they use to evaluate and select their arterial line filter.

Geology of the Southern Guadalupe Mountains, Texas

USGS Publications Warehouse

King, Philip B.

1948-01-01

This report deals with an area of 425 square miles in the western part of Texas, immediately south of the New Mexico line. The area comprises the south end of the Guadalupe Mountains and the adjacent part of the Delaware Mountains; it includes the highest peaks in the State of Texas. The area is a segment of a large mountain mass that extends 50 miles or more northward and southward. The report describes the geology of the area, that is, the nature of its rocks, tectonics, and surface features, and the evidence that they give as to the evolution of the area through geologic time. Incidental reference is made to the geology of surrounding regions in order to place the area in its environment. The Permian system of the southwestern United States has been until recently one of the intriguing but little known subjects of American stratigraphy. In the latter half of the nineteenth century after the western. United States was settled, the "red bed" sections of the Permian were studied and reported on by many geologists, but up to 1920 the existence of a contemporaneous marine sequence in western Texas and southeastern New Mexico was little appreciated. Since that year the discovery of extensive oil fields and potash beds in this region gave an impetus to the study of the Permian rocks, and furnished the geologist with records of hundreds of drill holes from which to deduce the nature of the strata not exposed at the surface. At the same time geologists have studied the rocks in the outcropping areas, and have compared them with the strata encountered by drilling.Much remains to be done in order to understand the history of Permian time in the region. The physical and chemical conditions that caused. the deposition of .the various and often complexly related deposits need to be better understood. More of the fossils of the rich and interesting marine faunas should be described, and the relations of the fossils to their environments should be determined. Further, a satisfactory scheme of correlation is needed, and also a subdivision into series that will express the contemporaneity of strata in different areas. One useful contribution to the solution of these problems is the detailed study of sequences of rocks exposed at the surface in the different mountain ranges of Texas and New Mexico.This report deals with one such sequence of rocks in western Texas, the one exposed in the southern Guadalupe Mountains (fig. 1). Here, the Permian rocks are magnificently exposed, to a thickness of about 4,000 feet (pl. 1). They are all of marine origin, and belong to the middle part of the system, with the base concealed and the top absent. Overlying and underlying beds, however, are found in nearby areas.

Mapping Aquifer Systems with Airborne Electromagnetics in the Central Valley of California

NASA Astrophysics Data System (ADS)

Knight, R. J.; Smith, R.; Asch, T. H.; Abraham, J.; Cannia, J.; Fogg, G. E.; Viezzoli, A.

2016-12-01

The Central Valley of California is an important agricultural region struggling to meet the need for irrigation water. Recent periods of drought have significantly reduced the delivery of surface water, resulting in extensive pumping of groundwater. This has exacerbated an already serious problem in the Central Valley, where a number of areas have experienced declining water levels for several decades leading to ongoing concerns about depletion of aquifers and impacts on ecosystems, as well as subsidence of the ground surface. The overdraft has been so significant, that there are now approximately140 million acre-feet (MAF) of unused groundwater storage in the Central Valley, storage that could be used to complement the 42 MAF of surface storage. The alluvial sedimentary geology of the Central Valley is typically composed of more than 50 to 70 percent fine-grained deposits dominated by silt and clay beds. These fine grained deposits can block potential recharge, and are associated with the large amount of observed subsidence. Fortunately, the geologic processes that formed the region created networks of sand and gravel which provide both a supply of water and pathways for recharge from the surface to the aquifers. The challenge is to find these sand and gravel deposits and thus identify optimal locations for surface spreading techniques so that recharge could be dramatically increased, and re-pressurization of the confined aquifer networks could be accomplished. We have acquired 100 line kilometers of airborne electromagnetic data over an area in the San Joaquin Valley, imaging the subsurface hydrostratigraphy to a depth of 500 m with spatial resolution on the order of meters to tens of meters. Following inversion of the data to obtain resistivity models along the flight lines, we used lithology logs in the area to transform the models to images displaying the distribution of sand and gravel, clay, and mixed fine and coarse materials. The quality of the data and final images are superb. The results of our survey have allowed us to1) better define the aquifer framework, that is needed to better model and manage groundwater, 2) gain insight into the geologic controls on the spatial variation in observed subsidence and 3) assist in identifying potential locations where recharge could prevent and/or reverse groundwater overdraft.

Study of Osteoclast Adhesion to Cortical Bone Surfaces: A Correlative Microscopy Approach for Concomitant Imaging of Cellular Dynamics and Surface Modifications

PubMed Central

2015-01-01

Bone remodeling relies on the coordinated functioning of osteoblasts, bone-forming cells, and osteoclasts, bone-resorbing cells. The effects of specific chemical and physical bone features on the osteoclast adhesive apparatus, the sealing zone ring, and their relation to resorption functionality are still not well-understood. We designed and implemented a correlative imaging method that enables monitoring of the same area of bone surface by time-lapse light microscopy, electron microscopy, and atomic force microscopy before, during, and after exposure to osteoclasts. We show that sealing zone rings preferentially develop around surface protrusions, with lateral dimensions of several micrometers, and ∼1 μm height. Direct overlay of sealing zone rings onto resorption pits on the bone surface shows that the rings adapt to pit morphology. The correlative procedure presented here is noninvasive and performed under ambient conditions, without the need for sample labeling. It can potentially be applied to study various aspects of cell-matrix interactions. PMID:26682493

Ultralow surface recombination velocity in InP nanowires probed by terahertz spectroscopy.

PubMed

Joyce, Hannah J; Wong-Leung, Jennifer; Yong, Chaw-Keong; Docherty, Callum J; Paiman, Suriati; Gao, Qiang; Tan, H Hoe; Jagadish, Chennupati; Lloyd-Hughes, James; Herz, Laura M; Johnston, Michael B

2012-10-10

Using transient terahertz photoconductivity measurements, we have made noncontact, room temperature measurements of the ultrafast charge carrier dynamics in InP nanowires. InP nanowires exhibited a very long photoconductivity lifetime of over 1 ns, and carrier lifetimes were remarkably insensitive to surface states despite the large nanowire surface area-to-volume ratio. An exceptionally low surface recombination velocity (170 cm/s) was recorded at room temperature. These results suggest that InP nanowires are prime candidates for optoelectronic devices, particularly photovoltaic devices, without the need for surface passivation. We found that the carrier mobility is not limited by nanowire diameter but is strongly limited by the presence of planar crystallographic defects such as stacking faults in these predominantly wurtzite nanowires. These findings show the great potential of very narrow InP nanowires for electronic devices but indicate that improvements in the crystallographic uniformity of InP nanowires will be critical for future nanowire device engineering.

Sensitivity of Climate Simulations to Land-Surface and Atmospheric Boundary-Layer Treatments-A Review.

NASA Astrophysics Data System (ADS)

Garratt, J. R.

1993-03-01

Aspects of the land-surface and boundary-layer treatments in some 20 or so atmospheric general circulation models (GCMS) are summarized. In only a small fraction of these have significant sensitivity studies been carried out and published. Predominantly, the sensitivity studies focus upon the parameterization of land-surface processes and specification of land-surface properties-the most important of these include albedo, roughness length, soil moisture status, and vegetation density. The impacts of surface albedo and soil moisture upon the climate simulated in GCMs with bare-soil land surfaces are well known. Continental evaporation and precipitation tend to decrease with increased albedo and decreased soil moisture availability. For example, results from numerous studies give an average decrease in continental precipitation of 1 mm day1 in response to an average albedo increase of 0.13. Few conclusive studies have been carried out on the impact of a gross roughness-length change-the primary study included an important statistical assessment of the impact upon the mean July climate around the globe of a decreased continental roughness (by three orders of magnitude). For example, such a decrease reduced the precipitation over Amazonia by 1 to 2 mm day1.The inclusion of a canopy scheme in a GCM ensures the combined impacts of roughness (canopies tend to be rougher than bare soil), albedo (canopies tend to be less reflective than bare soil), and soil-moisture availability (canopies prevent the near-surface soil region from drying out and can access the deep soil moisture) upon the simulated climate. The most revealing studies to date involve the regional impact of Amazonian deforestation. The results of four such studies show that replacing tropical forest with a degraded pasture results in decreased evaporation ( 1 mm day1) and precipitation (1-2 mm day1), and increased near-surface air temperatures (2 K).Sensitivity studies as a whole suggest the need for a realistic surface representation in general circulation models of the atmosphere. It is not yet clear how detailed this representation needs to be, but even allowing for the importance of surface processes, the parameterization of boundary-layer and convective clouds probably represents a greater challenge to improved climate simulations. This is illustrated in the case of surface net radiation for Aniazonia, which is not well simulated and tends to be overestimated, leading to evaporation rates that are too large. Underestimates in cloudiness, cloud albedo, and clear-sky shortwave absorption, rather than in surface albedo, appear to be the main culprits.There are three major tasks that confront the researcher so far as the development and validation of atmospheric boundary-layer (ABL) and surface schemes in GCMs are concerned:(i) There is a need to as' critically the impact of `improved' parameterization schemes on WM simulations, taking into account the problem of natural variability and hence the statistical significance of the induced changes.(ii) There is a need to compare GCM simulations of surface and ABL behavior (particularly regarding the diurnal cycle of surface fluxes, air temperature, and ABL depth) with observations over a range of surface types (vegetation, desert, ocean). In this context, area-average values of surface fluxes will be required to calibrate directly the ABL/land-surface scheme in the GCM.(iii) There is a need for intercomparisons of ABL and land-surface schemes used in GCMS, both for one- dimensional stand-alone models and for GCMs that incorporate the respective schemes.

Plasma-surface interaction in the context of ITER.

PubMed

Kleyn, A W; Lopes Cardozo, N J; Samm, U

2006-04-21

The decreasing availability of energy and concern about climate change necessitate the development of novel sustainable energy sources. Fusion energy is such a source. Although it will take several decades to develop it into routinely operated power sources, the ultimate potential of fusion energy is very high and badly needed. A major step forward in the development of fusion energy is the decision to construct the experimental test reactor ITER. ITER will stimulate research in many areas of science. This article serves as an introduction to some of those areas. In particular, we discuss research opportunities in the context of plasma-surface interactions. The fusion plasma, with a typical temperature of 10 keV, has to be brought into contact with a physical wall in order to remove the helium produced and drain the excess energy in the fusion plasma. The fusion plasma is far too hot to be brought into direct contact with a physical wall. It would degrade the wall and the debris from the wall would extinguish the plasma. Therefore, schemes are developed to cool down the plasma locally before it impacts on a physical surface. The resulting plasma-surface interaction in ITER is facing several challenges including surface erosion, material redeposition and tritium retention. In this article we introduce how the plasma-surface interaction relevant for ITER can be studied in small scale experiments. The various requirements for such experiments are introduced and examples of present and future experiments will be given. The emphasis in this article will be on the experimental studies of plasma-surface interactions.

Integral Radiator and Storage Tank

NASA Technical Reports Server (NTRS)

Burke, Kenneth A.; Miller, John R.; Jakupca, Ian; Sargi,Scott

2007-01-01

A simplified, lightweight system for dissipating heat of a regenerative fuel- cell system would include a heat pipe with its evaporator end placed at the heat source and its condenser end integrated into the wall of the regenerative fuel cell system gas-storage tanks. The tank walls act as heat-radiating surfaces for cooling the regenerative fuel cell system. The system was conceived for use in outer space, where radiation is the only physical mechanism available for transferring heat to the environment. The system could also be adapted for use on propellant tanks or other large-surface-area structures to convert them to space heat-radiating structures. Typically for a regenerative fuel cell system, the radiator is separate from the gas-storage tanks. By using each tank s surface as a heat-radiating surface, the need for a separate, potentially massive radiator structure is eliminated. In addition to the mass savings, overall volume is reduced because a more compact packaging scheme is possible. The underlying tank wall structure provides ample support for heat pipes that help to distribute the heat over the entire tank surface. The heat pipes are attached to the outer surface of each gas-storage tank by use of a high-thermal conductance, carbon-fiber composite-material wrap. Through proper choice of the composite layup, it is possible to exploit the high longitudinal conductivity of the carbon fibers (greater than the thermal conductivity of copper) to minimize the unevenness of the temperature distribution over the tank surface, thereby helping to maximize the overall heat-transfer efficiency. In a prototype of the system, the heat pipe and the composite wrap contribute an average mass of 340 g/sq m of radiator area. Lightweight space radiator panels have a mass of about 3,000 g/sq m of radiator area, so this technique saves almost 90 percent of the mass of separate radiator panels. In tests, the modified surface of the tank was found to have an emissivity of 0.85. The composite wrap remained tightly bound to the surface of the tank throughout the testing in thermal vacuum conditions.

Hierarchical zeolites from class F coal fly ash

NASA Astrophysics Data System (ADS)

Chitta, Pallavi

Fly ash, a coal combustion byproduct is classified as types class C and class F. Class C fly ash is traditionally recycled for concrete applications and Class F fly ash often disposed in landfills. Class F poses an environmental hazard due to disposal and leaching of heavy metals into ground water and is important to be recycled in order to mitigate the environmental challenges. A major recycling option is to reuse the fly ash as a low-cost raw material for the production of crystalline zeolites, which serve as catalysts, detergents and adsorbents in the chemical industry. Most of the prior literature of fly ash conversion to zeolites does not focus on creating high zeolite surface area zeolites specifically with hierarchical pore structure, which are very important properties in developing a heterogeneous catalyst for catalysis applications. This research work aids in the development of an economical process for the synthesis of high surface area hierarchical zeolites from class F coal fly ash. In this work, synthesis of zeolites from fly ash using classic hydrothermal treatment approach and fusion pretreatment approach were examined. The fusion pretreatment method led to higher extent of dissolution of silica from quartz and mullite phases, which in turn led to higher surface area and pore size of the zeolite. A qualitative kinetic model developed here attributes the difference in silica content to Si/Al ratio of the beginning fraction of fly ash. At near ambient crystallization temperatures and longer crystallization times, the zeolite formed is a hierarchical faujasite with high surface area of at least 360 m2/g. This work enables the large scale recycling of class F coal fly ash to produce zeolites and mitigate environmental concerns. Design of experiments was used to predict surface area and pore sizes of zeolites - thus obviating the need for intense experimentation. The hierarchical zeolite catalyst supports tested for CO2 conversion, yielded hydrocarbons up to C9, a performance attesting the hierarchal pore structure. The preliminary techno-economic feasibility assessment demonstrates a net energy saving of 75% and cost saving of 63% compared to the commercial zeolite manufacturing process.

Hydrology of Area 62, Northern Great Plains and Rocky Mountain Coal Provinces, New Mexico and Arizona

USGS Publications Warehouse

Roybal, F.E.; Wells, J.G.; Gold, R.L.; Flager, J.V.

1984-01-01

This report summarizes available hydrologic data for Area 62 and will aid leasing decisions, and the preparation and appraisal of environmental impact studies and mine-permit applications. Area 62 is located at the southern end of the Rocky Mountain Coal Province in parts of New Mexico and Arizona and includes approximately 9,500 square miles. Surface mining alters, at least temporarily, the environment; if the areas are unreclaimed, there can be long-term environmental consequences. The land-ownership pattern in Area 62 is complicated. The checkerboard pattern created by several types of ownership makes effective management of these lands difficult. The climate generally is semiarid with average annual precipitation ranging from 10 to 20 inches. Pinons, junipers, and grasslands cover most of the area, and much of it is used for grazing by livestock. Soils vary with landscape, differing from flood plains and hillslopes to mountain slopes. The major structural features of this area were largely developed during middle Tertiary time. The main structural features are the southern San Juan Basin and the Mogollon slope. Coal-bearing rocks are present in four Cretaceous rock units of the Mesaverde Group: the Gallup Sandstone, the Dileo Coal Member, and the Gibson Coal Member of the Crevasse Canyon Formation, and the Cleary Coal Member of the Menefee Formation. Area 62 is drained by Black Creek, the Puerco River, the Zuni River, Carrizo Wash-Largo Creek, and the Rio San Jose. Only at the headwaters of the Zuni River is the flow perennial. The streamflow-gaging station network consists of 25 stations operated for a variety of needs. Streamflow changes throughout the year with variation related directly to rainfall and snowmelt. Base flow in Area 62 is zero indicating no significant ground-water discharge. Mountainous areas contribute the highest mean annual runoff of 1.0 inch. Very few water-quality data are available for the surface-water stations. Of the nine surface-water stations that have water-quality data, only one has chemical analyses from more than 10 samples. Therefore, sufficient data to characterize the area in detail are not available. Suspended sediment data are available only for a few surface- water stations in the area. Erosion rates generally are less than 1 acre-foot per square mile per year. Greater erosion rates are found within the badland areas. Water levels are periodically measured at 21 selected wells in Area 62. These observation wells are located mostly along the Rio San Jose and northeast of Gallup, New Mexico. The recharge to ground-water aquifers generally coincide with areas of greater precipitation in the mountainous areas. Depth to water below land surface is generally less than 200 feet. Well yields of 100 gallons per minute are common in most of the area. Ground-water quality is variable both within each aquifer and between aquifers. Water quality generally is best near recharge areas. Historical and current data related to stream discharge, water quality, and suspended sediment are available from computer files in the U.S. Geological Survey's National Water Data Storage and Retrieval System (WATSTORE) and through the National Water Data Exchange (NAWDEX).

Effect of solution and leaf surface polarity on droplet spread area and contact angle.

PubMed

Nairn, Justin J; Forster, W Alison; van Leeuwen, Rebecca M

2016-03-01

How much an agrochemical spray droplet spreads on a leaf surface can significantly influence efficacy. This study investigates the effect solution polarity has on droplet spreading on leaf surfaces and whether the relative leaf surface polarity, as quantified using the wetting tension dielectric (WTD) technique, influences the final spread area. Contact angles and spread areas were measured using four probe solutions on 17 species. Probe solution polarity was found to affect the measured spread area and the contact angle of the droplets on non-hairy leaves. Leaf hairs skewed the spread area measurement, preventing investigation of the influence of surface polarity on hairy leaves. WTD-measured leaf surface polarity of non-hairy leaves was found to correlate strongly with the effect of solution polarity on spread area. For non-polar leaf surfaces the spread area decreases with increasing solution polarity, for neutral surfaces polarity has no effect on spread area and for polar leaf surfaces the spread area increases with increasing solution polarity. These results attest to the use of the WTD technique as a means to quantify leaf surface polarity. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Better utilization of ground water in the Piedmont and mountain region of the southeast

USGS Publications Warehouse

Heath, Ralph C.

1979-01-01

The development of water supplies for domestic consumption, and for those commercial and industrial uses requiring relatively pure water, has followed a pattern in the Piedmont and mountain areas of the southeast similar to that in most other humid areas. The first settlers utilized seepage springs on hillsides. Such springs occur along steep slopes where the water table intersects the land surface. As the population of the region grew, it became increasingly necessary to resort to shallow dug wells for domestic water supplies. Such wells also served as sources of water for the villages that developed, in time, around crossroad taverns. Seepage springs and dug wells are a satisfactory source of water in a virgin environment but are quickly polluted by careless waste-disposal practices. Thus disposal of domestic wastes in shallow pits resulted in epidemics of water-borne diseases as the villages grew into towns. This resulted in the third phase of water-supply development, which consisted of installing water lines and supplying water to homes from town-owned wells. In time, some of these wells became polluted and others failed to supply adequate water for the increasing needs of the larger urban areas. In the fourth phase these areas met their needs by drawing water from nearby streams. By the early years of this century it was possible to make this water palatable and relatively safe as a result of improvement in filtration methods. Streams, of course, have highly variable rates of flow and, as towns grew into small cities, the minimum flow of many streams was not adequate to meet the water-supply needs. This problem was solved in the fifth phase by building dams on the streams. We are still in this phase as we build larger and larger reservoirs to meet our growing water needs. Thus, through five phases of growth in the Piedmont and mountains we have advanced from the point where ground water was the sole source of supply to the point where it is the forgotten resource. For reasons to be explained below, a sixth phase can be foreseen in which ground water and surface water are recognized as parts of the hydrologic system with advantages in their conjunctive development and use.

Shell Canada Limited application for a well license, Quirk Creek field, LSD 16-19-21-4 W5M: Decision 98-9, application number 970451

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

NONE

1998-09-01

Shell Canada Ltd. applied to the Alberta Energy and Utilities Board for a license to drill a deviated sour gas exploration well from a location in the Kananaskis Country Recreation Area. This report presents the views of Shell, the Board, and various intervenors at a hearing held to consider matters related to the application. Issues discussed include the need for the well, the surface location of the well, access management, environmental impacts, the need for an environmental assessment, and public safety. The report concludes with the Board`s decision and conditions for approval.

Feasibility of using Big Area Additive Manufacturing to Directly Manufacture Boat Molds

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

Post, Brian K.; Chesser, Phillip C.; Lind, Randall F.

The goal of this project was to explore the feasibility of using Big Area Additive Manufacturing (BAAM) to directly manufacture a boat mold without the need for coatings. All prior tooling projects with BAAM required the use to thick coatings to overcome the surface finish limitations of the BAAM process. While the BAAM process significantly lowers the cost of building the mold, the high cost element rapidly became the coatings (cost of the material, labor on coating, and finishing). As an example, the time and cost to manufacture the molds for the Wind Turbine project with TPI Composites Inc. andmore » the molds for the submarine project with Carderock Naval Warfare Systems was a fraction of the time and cost of the coatings. For this project, a catamaran boat hull mold was designed, manufactured, and assembled with an additional 0.15” thickness of material on all mold surfaces. After printing, the mold was immediately machined and assembled. Alliance MG, LLC (AMG), the industry partner of this project, experimented with mold release agents on the carbon-fiber reinforced acrylonitrile butadiene styrene (CF ABS) to verify that the material can be directly used as a mold (rather than needing a coating). In addition, for large molds (such as the wind turbine mold with TPI Composites Inc.), the mold only provided the target surface. A steel subframe had to be manufactured to provide structural integrity. If successful, this will significantly reduce the time and cost necessary for manufacturing large resin infusion molds using the BAAM process.« less

Efficacy of simple short-term in vitro assays for predicting the potential of metal oxide nanoparticles to cause pulmonary inflammation.

PubMed

Lu, Senlin; Duffin, Rodger; Poland, Craig; Daly, Paul; Murphy, Fiona; Drost, Ellen; Macnee, William; Stone, Vicki; Donaldson, Ken

2009-02-01

There has been concern regarding risks from inhalation exposure to nanoparticles (NPs). The large number of particles requiring testing means that alternative approaches to animal testing are needed. We set out to determine whether short-term in vitro assays that assess intrinsic oxidative stress potential and membrane-damaging potency of a panel of metal oxide NPs can be used to predict their inflammogenic potency. For a panel of metal oxide NPs, we investigated intrinsic free radical generation, oxidative activity in an extracellular environment, cytotoxicity to lung epithelial cells, hemolysis, and inflammation potency in rat lungs. All exposures were carried out at equal surface area doses. Only nickel oxide (NiO) and alumina 2 caused significant lung inflammation when instilled into rat lungs at equal surface area, suggesting that these two had extra surface reactivity. We observed significant free radical generation with 4 of 13 metal oxides, only one of which was inflammogenic. Only 3 of 13 were significantly hemolytic, two of which were inflammogenic. Potency in generating free radicals in vitro did not predict inflammation, whereas alumina 2 had no free radical activity but was inflammogenic. The hemolysis assay was correct in predicting the proinflammatory potential of 12 of 13 of the particles examined. Using a battery of simple in vitro tests, it is possible to predict the inflammogenicity of metal oxide NPs, although some false-positive results are likely. More research using a larger panel is needed to confirm the efficacy and generality of this approach for metal oxide NPs.

A review of the fate of engineered nanomaterials in municipal solid waste streams.

PubMed

Part, Florian; Berge, Nicole; Baran, Paweł; Stringfellow, Anne; Sun, Wenjie; Bartelt-Hunt, Shannon; Mitrano, Denise; Li, Liang; Hennebert, Pierre; Quicker, Peter; Bolyard, Stephanie C; Huber-Humer, Marion

2018-05-01

Significant knowledge and data gaps associated with the fate of product-embedded engineered nanomaterials (ENMs) in waste management processes exist that limit our current ability to develop appropriate end-of-life management strategies. This review paper was developed as part of the activities of the IWWG ENMs in Waste Task Group. The specific objectives of this review paper are to assess the current knowledge associated with the fate of ENMs in commonly used waste management processes, including key processes and mechanisms associated with ENM fate and transport in each waste management process, and to use that information to identify the data gaps and research needs in this area. Literature associated with the fate of ENMs in wastes was reviewed and summarized. Overall, results from this literature review indicate a need for continued research in this area. No work has been conducted to quantify ENMs present in discarded materials and an understanding of ENM release from consumer products under conditions representative of those found in relevant waste management process is needed. Results also indicate that significant knowledge gaps associated with ENM behaviour exist for each waste management process investigated. There is a need for additional research investigating the fate of different types of ENMs at larger concentration ranges with different surface chemistries. Understanding how changes in treatment process operation may influence ENM fate is also needed. A series of specific research questions associated with the fate of ENMs during the management of ENM-containing wastes have been identified and used to direct future research in this area. Copyright © 2018 Elsevier Ltd. All rights reserved.

Shallow Alluvial Aquifer Ground Water System and Surface Water/Ground Water Interaction, Boulder Creek, Boulder, Colorado

NASA Astrophysics Data System (ADS)

Babcock, K. P.; Ge, S.; Crifasi, R. R.

2006-12-01

Water chemistry in Boulder Creek, Colorado, shows significant variation as the Creek flows through the City of Boulder [Barber et al., 2006]. This variation is partially due to ground water inputs, which are not quantitatively understood. The purpose of this study is (1) to understand ground water movement in a shallow alluvial aquifer system and (2) to assess surface water/ground water interaction. The study area, encompassing an area of 1 mi2, is located at the Sawhill and Walden Ponds area in Boulder. This area was reclaimed by the City of Boulder and Boulder County after gravel mining operations ceased in the 1970's. Consequently, ground water has filled in the numerous gravel pits allowing riparian vegetation regrowth and replanting. An integrated approach is used to examine the shallow ground water and surface water of the study area through field measurements, water table mapping, graphical data analysis, and numerical modeling. Collected field data suggest that lateral heterogeneity exists throughout the unconsolidated sediment. Alluvial hydraulic conductivities range from 1 to 24 ft/day and flow rates range from 0.01 to 2 ft/day. Preliminary data analysis suggests that ground water movement parallels surface topography and does not noticeably vary with season. Recharge via infiltrating precipitation is dependent on evapotranspiration (ET) demands and is influenced by preferential flow paths. During the growing season when ET demand exceeds precipitation rates, there is little recharge; however recharge occurs during cooler months when ET demand is insignificant. Preliminary data suggest that the Boulder Creek is gaining ground water as it traverses the study area. Stream flow influences the water table for distances up to 400 feet. The influence of stream flow is reflected in the zones relatively low total dissolved solids concentration. A modeling study is being conducted to synthesize aquifer test data, ground water levels, and stream flow data. The model will quantitatively assess the interaction between surface water and ground water, particularly the amount of exchange between the creek and ground water and to what extent these systems influence each other. Model sensitivity study will help identify important system parameters. A comprehensive model of the study area will serve as a tool for efficiently allocating water throughout the study area (from Boulder Creek). Water allocation is needed to prevent the eutrophication of the ponds, improve fishery management, and efficiently meet the water rights obligations in the watershed.

Monitoring of chlorophyll-a and sea surface silicate concentrations in the south part of Cheju island in the East China sea using MODIS data

NASA Astrophysics Data System (ADS)

Zhang, Yuanzhi; Huang, Zhaojun; Fu, Dongyang; Tsou, Jin Yeu; Jiang, Tingchen; Liang, X. San; Lu, Xia

2018-05-01

Continually supplied with nutrients, phytoplankton maintains high productivity under ideal illumination and temperature conditions. Data in the south part of Cheju Island in the East China Sea (ECS), which has experienced a spring bloom since the 2000s, were acquired during a research cruise in the spring of 2007. Compared with in-situ measurements, MODIS chlorophyll-a measurements showed high stability in this area. Excluding some invalid stations data, the relationships between nutrients and chlorophyll-a concentrations in the study area were examined and compared with the results in 2015. A high positive correlation between silicate and chlorophyll-a concentration was identified, and a regression relationship was proposed. MODIS chlorophyll-a measurements and sea surface temperature were utilized to determine surface silicate distribution. The silicate concentration retrieved from MODIS exhibited good agreement with in-situ measurements with R2 of 0.803, root mean square error (RMSE) of 0.326 μmol/L (8.23%), and mean absolute error (MAE) of 0.925 μmol/L (23.38%). The study provides a new solution to identify nutrient distributions using satellite data such as MODIS for water bodies, but the method still needs to be refined to determine the relationship of chlorophyll-a and nutrients during other seasons to monitor water quality in this and other areas.

Fair performance comparison of different carbon blacks in lithium-sulfur batteries with practical mass loadings - Simple design competes with complex cathode architecture

NASA Astrophysics Data System (ADS)

Jozwiuk, Anna; Sommer, Heino; Janek, Jürgen; Brezesinski, Torsten

2015-11-01

The lithium-sulfur system is one of the most promising next generation battery systems, as elemental sulfur is cheap, abundant and has a high theoretical specific capacity. Although much research is conducted on complex sulfur/carbon composites and architectures, it is difficult to compare the performance of the cathodes to one another. Factors, such as different electrolyte composition and cell components strongly affect the cyclability of the battery. Here, we show the importance of optimizing ;standard; conditions to allow for fair performance comparison of different carbon blacks. Our optimal electrolyte-to-sulfur ratio is 11 μL mgsulfur-1 and high concentrations of LiNO3 (>0.6 M) are needed because nitrate is consumed continuously during cycling. Utilizing these standard conditions, we tested the cycling behavior of four types of cathodes with individual carbon blacks having different specific surface areas, namely Printex-A, Super C65, Printex XE-2 and Ketjenblack EC-600JD. Both the specific capacity and polysulfide adsorption capability clearly correlate with the surface area of the carbon being used. High specific capacities (>1000 mAh gsulfur-1 at C/5) are achieved with high surface area carbons. We also demonstrate that a simple cathode using Ketjenblack EC-600JD as the conductive matrix material can well compete with those having complex architectures or additives.

Grid-Sphere Electrodes for Contact with Ionospheric Plasma

NASA Technical Reports Server (NTRS)

Stone, Nobie H.; Poe, Garrett D.

2010-01-01

Grid-sphere electrodes have been proposed for use on the positively biased end of electrodynamic space tethers. A grid-sphere electrode is fabricated by embedding a wire mesh in a thin film from which a spherical balloon is formed. The grid-sphere electrode would be deployed from compact stowage by inflating the balloon in space. The thin-film material used to inflate the balloon is formulated to vaporize when exposed to the space environment. This would leave the bare metallic spherical grid electrode attached to the tether, which would present a small cross-sectional area (essentially, the geometric wire shadow area only) to incident neutral atoms and molecules. Most of the neutral particles, which produce dynamic drag when they impact a surface, would pass unimpeded through the open grid spaces. However, partly as a result of buildup of a space charge inside the grid-sphere, and partially, the result of magnetic field effects, the electrode would act almost like a solid surface with respect to the flux of electrons. The net result would be that grid-sphere electrodes would introduce minimal aerodynamic drag, yet have effective electrical-contact surface areas large enough to collect multiampere currents from the ionospheric plasma that are needed for operation of electrodynamic tethers. The vaporizable-balloon concept could also be applied to the deployment of large radio antennas in outer space.

Ocean-Atmosphere Interactions Modulate Irrigation's Climate Impacts

NASA Technical Reports Server (NTRS)

Krakauer, Nir Y.; Puma, Michael J.; Cook, Benjamin I.; Gentine, Pierre; Nazarenko, Larissa

2016-01-01

Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean- atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity. We find that ocean-atmosphere interaction does impact the magnitude of global-mean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, particularly over the oceans, tend to be larger. The interaction amplifies irrigation-driven standing wave patterns in the tropics and mid-latitudes in our simulations, approximately doubling the global-mean amplitude of surface temperature changes due to irrigation. The fractions of global area experiencing significant annual-mean surface air temperature and precipitation change also approximately double with ocean-atmosphere interaction. Subject to confirmation with other models, these findings imply that LCLUC is an important contributor to climate change even in remote areas such as the Southern Ocean, and that attribution studies should include interactive oceans and need to consider LCLUC, including irrigation, as a truly global forcing that affects climate and the water cycle over ocean as well as land areas.

Improved MODIS aerosol retrieval in urban areas using a land classification approach and empirical orthogonal functions

NASA Astrophysics Data System (ADS)

Levitan, Nathaniel; Gross, Barry

2016-10-01

New, high-resolution aerosol products are required in urban areas to improve the spatial coverage of the products, in terms of both resolution and retrieval frequency. These new products will improve our understanding of the spatial variability of aerosols in urban areas and will be useful in the detection of localized aerosol emissions. Urban aerosol retrieval is challenging for existing algorithms because of the high spatial variability of the surface reflectance, indicating the need for improved urban surface reflectance models. This problem can be stated in the language of novelty detection as the problem of selecting aerosol parameters whose effective surface reflectance spectrum is not an outlier in some space. In this paper, empirical orthogonal functions, a reconstruction-based novelty detection technique, is used to perform single-pixel aerosol retrieval using the single angular and temporal sample provided by the MODIS sensor. The empirical orthogonal basis functions are trained for different land classes using the MODIS BRDF MCD43 product. Existing land classification products are used in training and aerosol retrieval. The retrieval is compared against the existing operational MODIS 3 KM Dark Target (DT) aerosol product and co-located AERONET data. Based on the comparison, our method allows for a significant increase in retrieval frequency and a moderate decrease in the known biases of MODIS urban aerosol retrievals.

Pilot Scale Production of Activated Carbon Spheres Using Fluidized Bed Reactor and Its Evaluation for the Removal of Hexavalent Chromium from Aqueous Solutions

NASA Astrophysics Data System (ADS)

Tripathi, Nagesh Kumar; Sathe, Manisha

2017-12-01

Large scale production of activated carbon is need of ongoing research due to its excellent adsorption capacity for removal of heavy metals from contaminated solutions. In the present study, polymeric precursor polystyrene beads [Brunauer Emmett Teller (BET) surface area, 46 m2/g; carbon content, 40.64%; crushing strength, 0.32 kg/sphere] were used to produce a new variant of activated carbon, Activated Carbon Spheres (ACS) in a pilot scale fluidized bed reactor. ACS were prepared by carbonization of polymeric precursor at 850 °C followed by activation of resultant material with steam. Prepared ACS were characterized using scanning electron microscope, CHNS analyzer, thermogravimetric analyzer, surface area analyzer and crushing strength tester. The produced ACS have 1009 m2/g BET surface area, 0.89 cm3/g total pore volume, 92.32% carbon content and 1.1 kg/sphere crushing strength with less than 1% of moisture and ash content. The ACS were also evaluated for its potential to remove hexavalent chromium [Cr(VI)] from contaminated solutions. The chromium removal is observed to be 99.1% at initial concentration 50 mg/l, pH 2, ACS dose 1 g/l, contact time 2 h, agitation 120 rpm and temperature 30 °C. Thus ACS can be used as an adsorbent material for the removal of Cr(VI) from contaminated solutions.

Potential sources of nitrous acid (HONO) and their impacts on ozone: A WRF-Chem study in a polluted subtropical region

NASA Astrophysics Data System (ADS)

Zhang, Li; Wang, Tao; Zhang, Qiang; Zheng, Junyu; Xu, Zheng; Lv, Mengyao

2016-04-01

Current chemical transport models commonly undersimulate the atmospheric concentration of nitrous acid (HONO), which plays an important role in atmospheric chemistry, due to the lack or inappropriate representations of some sources in the models. In the present study, we parameterized up-to-date HONO sources into a state-of-the-art three-dimensional chemical transport model (Weather Research and Forecasting model coupled with Chemistry: WRF-Chem). These sources included (1) heterogeneous reactions on ground surfaces with the photoenhanced effect on HONO production, (2) photoenhanced reactions on aerosol surfaces, (3) direct vehicle and vessel emissions, (4) potential conversion of NO2 at the ocean surface, and (5) emissions from soil bacteria. The revised WRF-Chem was applied to explore the sources of the high HONO concentrations (0.45-2.71 ppb) observed at a suburban site located within complex land types (with artificial land covers, ocean, and forests) in Hong Kong. With the addition of these sources, the revised model substantially reproduced the observed HONO levels. The heterogeneous conversions of NO2 on ground surfaces dominated HONO sources contributing about 42% to the observed HONO mixing ratios, with emissions from soil bacterial contributing around 29%, followed by the oceanic source (~9%), photochemical formation via NO and OH (~6%), conversion on aerosol surfaces (~3%), and traffic emissions (~2%). The results suggest that HONO sources in suburban areas could be more complex and diverse than those in urban or rural areas and that the bacterial and/or ocean processes need to be considered in HONO production in forested and/or coastal areas. Sensitivity tests showed that the simulated HONO was sensitive to the uptake coefficient of NO2 on the surfaces. Incorporation of the aforementioned HONO sources significantly improved the simulations of ozone, resulting in increases of ground-level ozone concentrations by 6-12% over urban areas in Hong Kong and the Pearl River Delta region. This result highlights the importance of accurately representing HONO sources in simulations of secondary pollutants over polluted regions.

Modelling MIZ dynamics in a global model

NASA Astrophysics Data System (ADS)

Rynders, Stefanie; Aksenov, Yevgeny; Feltham, Daniel; Nurser, George; Naveira Garabato, Alberto

2016-04-01

Exposure of large, previously ice-covered areas of the Arctic Ocean to the wind and surface ocean waves results in the Arctic pack ice cover becoming more fragmented and mobile, with large regions of ice cover evolving into the Marginal Ice Zone (MIZ). The need for better climate predictions, along with growing economic activity in the Polar Oceans, necessitates climate and forecasting models that can simulate fragmented sea ice with a greater fidelity. Current models are not fully fit for the purpose, since they neither model surface ocean waves in the MIZ, nor account for the effect of floe fragmentation on drag, nor include sea ice rheology that represents both the now thinner pack ice and MIZ ice dynamics. All these processes affect the momentum transfer to the ocean. We present initial results from a global ocean model NEMO (Nucleus for European Modelling of the Ocean) coupled to the Los Alamos sea ice model CICE. The model setup implements a novel rheological formulation for sea ice dynamics, accounting for ice floe collisions, thus offering a seamless framework for pack ice and MIZ simulations. The effect of surface waves on ice motion is included through wave pressure and the turbulent kinetic energy of ice floes. In the multidecadal model integrations we examine MIZ and basin scale sea ice and oceanic responses to the changes in ice dynamics. We analyse model sensitivities and attribute them to key sea ice and ocean dynamical mechanisms. The results suggest that the effect of the new ice rheology is confined to the MIZ. However with the current increase in summer MIZ area, which is projected to continue and may become the dominant type of sea ice in the Arctic, we argue that the effects of the combined sea ice rheology will be noticeable in large areas of the Arctic Ocean, affecting sea ice and ocean. With this study we assert that to make more accurate sea ice predictions in the changing Arctic, models need to include MIZ dynamics and physics.

Informal e-waste recycling: environmental risk assessment of heavy metal contamination in Mandoli industrial area, Delhi, India.

PubMed

Pradhan, Jatindra Kumar; Kumar, Sudhir

2014-01-01

Nowadays, e-waste is a major source of environmental problems and opportunities due to presence of hazardous elements and precious metals. This study was aimed to evaluate the pollution risk of heavy metal contamination by informal recycling of e-waste. Environmental risk assessment was determined using multivariate statistical analysis, index of geoaccumulation, enrichment factor, contamination factor, degree of contamination and pollution load index by analysing heavy metals in surface soils, plants and groundwater samples collected from and around informal recycling workshops in Mandoli industrial area, Delhi, India. Concentrations of heavy metals like As (17.08 mg/kg), Cd (1.29 mg/kg), Cu (115.50 mg/kg), Pb (2,645.31 mg/kg), Se (12.67 mg/kg) and Zn (776.84 mg/kg) were higher in surface soils of e-waste recycling areas compared to those in reference site. Level exceeded the values suggested by the US Environmental Protection Agency (EPA). High accumulations of heavy metals were also observed in the native plant samples (Cynodon dactylon) of e-waste recycling areas. The groundwater samples collected form recycling area had high heavy metal concentrations as compared to permissible limit of Indian Standards and maximum allowable limit of WHO guidelines for drinking water. Multivariate analysis and risk assessment studies based on total metal content explains the clear-cut differences among sampling sites and a strong evidence of heavy metal pollution because of informal recycling of e-waste. This study put forward that prolonged informal recycling of e-waste may accumulate high concentration of heavy metals in surface soils, plants and groundwater, which will be a matter of concern for both environmental and occupational hazards. This warrants an immediate need of remedial measures to reduce the heavy metal contamination of e-waste recycling sites.

Fluvial erosion and post-erosional processes on Titan

USGS Publications Warehouse

Jaumann, R.; Brown, R.H.; Stephan, K.; Barnes, J.W.; Soderblom, L.A.; Sotin, Christophe; Le, Mouelic S.; Clark, R.N.; Soderblom, J.; Buratti, B.J.; Wagner, R.; McCord, T.B.; Rodriguez, S.; Baines, K.H.; Cruikshank, D.P.; Nicholson, P.D.; Griffith, C.A.; Langhans, M.; Lorenz, R.D.

2008-01-01

The surface of Titan has been revealed by Cassini observations in the infrared and radar wavelength ranges as well as locally by the Huygens lander instruments. Sand seas, recently discovered lakes, distinct landscapes and dendritic erosion patterns indicate dynamic surface processes. This study focus on erosional and depositional features that can be used to constrain the amount of liquids involved in the erosional process as well as on the compositional characteristics of depositional areas. Fluvial erosion channels on Titan as identified at the Huygens landing site and in RADAR and Visible and Infrared Mapping Spectrometer (VIMS) observations have been compared to analogous channel widths on Earth yielding average discharges of up to 1600 m3/s for short recurrence intervals that are sufficient to move centimeter-sized sediment and significantly higher discharges for long intervals. With respect to the associated drainage areas, this roughly translates to 1-150 cm/day runoff production rates with 10 years recurrence intervals and by assuming precipitation this implies 0.6-60 mm/h rainfall rates. Thus the observed surface erosion fits with the methane convective storm models as well as with the rates needed to transport sediment. During Cassini's T20 fly-by, the VIMS observed an extremely eroded area at 30?? W, 7?? S with resolutions of up to 500 m/pixel that extends over thousands of square kilometers. The spectral characteristics of this area change systematically, reflecting continuous compositional and/or particle size variations indicative of transported sediment settling out while flow capacities cease. To account for the estimated runoff production and widespread alluvial deposits of fine-grained material, release of area-dependent large fluid volumes are required. Only frequent storms with heavy rainfall or cryovolcanic induced melting can explain these erosional features. ?? 2008 Elsevier Inc.

Applying Geospatial Techniques to Investigate Boundary Layer Land-Atmosphere Interactions Involved in Tornadogensis

NASA Astrophysics Data System (ADS)

Weigel, A. M.; Griffin, R.; Knupp, K. R.; Molthan, A.; Coleman, T.

2017-12-01

Northern Alabama is among the most tornado-prone regions in the United States. This region has a higher degree of spatial variability in both terrain and land cover than the more frequently studied North American Great Plains region due to its proximity to the southern Appalachian Mountains and Cumberland Plateau. More research is needed to understand North Alabama's high tornado frequency and how land surface heterogeneity influences tornadogenesis in the boundary layer. Several modeling and simulation studies stretching back to the 1970's have found that variations in the land surface induce tornadic-like flow near the surface, illustrating a need for further investigation. This presentation introduces research investigating the hypothesis that horizontal gradients in land surface roughness, normal to the direction of flow in the boundary layer, induce vertically oriented vorticity at the surface that can potentially aid in tornadogenesis. A novel approach was implemented to test this hypothesis using a GIS-based quadrant pattern analysis method. This method was developed to quantify spatial relationships and patterns between horizontal variations in land surface roughness and locations of tornadogenesis. Land surface roughness was modeled using the Noah land surface model parameterization scheme which, was applied to MODIS 500 m and Landsat 30 m data in order to compare the relationship between tornadogenesis locations and roughness gradients at different spatial scales. This analysis found a statistical relationship between areas of higher roughness located normal to flow surrounding tornadogenesis locations that supports the tested hypothesis. In this presentation, the innovative use of satellite remote sensing data and GIS technologies to address interactions between the land and atmosphere will be highlighted.

Simulation and assessment of groundwater flow and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2003 through 2013: Chapter B of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

USGS Publications Warehouse

Jones, Perry M.; Roth, Jason L.; Trost, Jared J.; Christenson, Catherine A.; Diekoff, Aliesha L.; Erickson, Melinda L.

2017-09-05

Water levels during 2003 through 2013 were less than mean water levels for the period 1925–2013 for several lakes in the northeast Twin Cities Metropolitan Area in Minnesota. Previous periods of low lake-water levels generally were correlated with periods with less than mean precipitation. Increases in groundwater withdrawals and land-use changes have brought into question whether or not recent (2003–13) lake-water-level declines are solely caused by decreases in precipitation. A thorough understanding of groundwater and surface-water exchanges was needed to assess the effect of water-management decisions on lake-water levels. To address this need, the U.S. Geological Survey, in cooperation with the Metropolitan Council and the Minnesota Department of Health, developed and calibrated a three-dimensional, steady-state groundwater-flow model representing 2003–13 mean hydrologic conditions to assess groundwater and lake-water exchanges, and the effects of groundwater withdrawals and precipitation on water levels of 96 lakes in the northeast Twin Cities Metropolitan Area.Lake-water budgets for the calibrated groundwater-flow model indicated that groundwater is flowing into lakes in the northeast Twin Cities Metropolitan Area and lakes are providing water to underlying aquifers. Lake-water outflow to the simulated groundwater system was a major outflow component for Big Marine Lake, Lake Elmo, Snail Lake, and White Bear Lake, accounting for 45 to 64 percent of the total outflows from the lakes. Evaporation and transpiration from the lake surface ranged from 19 to 52 percent of the total outflow from the four lakes. Groundwater withdrawals and precipitation were varied from the 2003‒13 mean values used in the calibrated model (30-percent changes in groundwater withdrawals and 5-percent changes in precipitation) for hypothetical scenarios to assess the effects of groundwater withdrawals and precipitation on water budgets and levels in Big Marine Lake, Snail Lake, and White Bear Lake. Simulated lake-water levels and budgets for Snail Lake and White Bear Lake were affected by 30-percent changes in groundwater withdrawals and 5-percent changes in precipitation in the area, whereas the water level in Big Marine Lake was mainly affected by 5-percent precipitation changes. The effects of groundwater withdrawals on the lake-water levels depend on the number of wells and amount of withdrawals from wells near the lakes. Although lake-water levels are sensitive to precipitation changes, increases in groundwater withdrawals during dry periods exacerbate lake-water level declines. The calibrated, groundwater-flow model is a tool that water-resources managers can use to address future water management issues in the northeast Twin Cities Metropolitan Area.

Quantifying Ground-Water and Surface-Water Discharge from Evapotranspiration Processes in 12 Hydrographic Areas of the Colorado Regional Ground-Water Flow System, Nevada, Utah, and Arizona

USGS Publications Warehouse

DeMeo, Guy A.; Smith, J. LaRue; Damar, Nancy A.; Darnell, Jon

2008-01-01

Rapid population growth in southern Nevada has increased the demand for additional water supplies from rural areas of northern Clark and southern Lincoln counties to meet projected water-supply needs. Springs and rivers in these undeveloped areas sustain fragile riparian habitat and may be susceptible to ground-water withdrawals. Most natural ground-water and surface-water discharge from these basins occurs by evapotranspiration (ET) along narrow riparian corridors that encompassed about 45,000 acres or about 1 percent of the study area. This report presents estimates of ground- and surface-water discharge from ET across 3.5 million acres in 12 hydrographic areas of the Colorado Regional Ground-Water Flow System. Ground-and surface-water discharge from ET were determined by identifying areas of ground- and surface-water ET, delineating areas of similar vegetation and soil conditions (ET units), and computing ET rates for each of these ET units. Eight ET units were identified using spectral-reflectance characteristics determined from 2003 satellite imagery, high-resolution aerial photography, and land classification cover. These ET units are dense meadowland vegetation (200 acres), dense woodland vegetation (7,200 acres), moderate woodland vegetation (6,100 acres), dense shrubland vegetation (5,800 acres), moderate shrubland vegetation (22,600 acres), agricultural fields (3,100 acres), non-phreatophytic areas (3,400,000 acres), and open water (300 acres). ET from diffuse ground-water and channelized surface-water is expressed as ETgs and is equal to the difference between total annual ET and precipitation. Total annual ET rates were calculated by the Bowen ratio and eddy covariance methods using micrometeorological data collected from four sites and estimated at 3.9 ft at a dense woodland site (February 2003 to March 2005), 3.6 ft at a moderate woodland site (July 2003 to October 2006), 2.8 ft at a dense shrubland site (June 2005 to October 2006), and 1.5 ft at a moderate shrubland site (April 2006 to October 2006). Annual ETgs rates were 3.4 ft for dense woodland vegetation, 3.2 ft for moderate woodland vegetation, 2.2 ft for dense shrubland vegetation, and 1.0 ft for moderate shrubland vegetation. Published annual rates of ETgs were used for the other ET units found in the study area. These rates were 3.4 ft for dense meadowland vegetation, 5.2 ft for agricultural fields, and 4.9 ft for open water. For the non-phreatophytic ET unit, ETgs was assumed to be zero. Estimated ground- and surface-water discharge from ET was calculated by multiplying the ETgs by the ET-unit acreage and equaled 24,480 acre-ft for dense woodland vegetation, 19,520 acre-ft for moderate woodland vegetation, 12,760 acre-ft for dense shrubland vegetation, 22,600 acre-ft for moderate shrubland vegetation, 680 acre-ft for dense meadowland vegetation, 16,120 acre-ft for agricultural fields, 1,440 acre-ft for open water, and 0 acre-ft for the non-phreatophytic ET unit. Estimated ground-water and surface-water discharge from ET from each hydrographic area was calculated by summing the total annual ETgs rate for ET units found within each hydrographic area and equaled 1,952 acre-ft for the Black Mountains Area, 6,080 acre-ft for California Wash, 4,090 acre-ft for the Muddy River Springs Area, 11,510 acre-ft for Lower Moapa Valley, 51,960 acre-ft for the Virgin River Valley, 16,168 acre-ft for Lower Meadow Valley Wash, 5,840 acre-ft for Clover Valley, and 0 acre-ft for Coyote Spring Valley, Kane Springs Valley, Tule Desert, Hidden Valley (North), and Garnet Valley. The annual discharge from ETgs for the study area totals about 98,000 acre-ft.

Properties that influence the specific surface areas of carbon nanotubes and nanofibers.

PubMed

Birch, M Eileen; Ruda-Eberenz, Toni A; Chai, Ming; Andrews, Ronnee; Hatfield, Randal L

2013-11-01

Commercially available carbon nanotubes and nanofibers were analyzed to examine possible relationships between their Brunauer-Emmett-Teller specific surface areas (SSAs) and their physical and chemical properties. Properties found to influence surface area were number of walls/diameter, impurities, and surface functionalization with hydroxyl and carboxyl groups. Characterization by electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and elemental analysis indicates that SSA can provide insight on carbon nanomaterials properties, which can differ vastly depending on synthesis parameters and post-production treatments. In this study, how different properties may influence surface area is discussed. The materials examined have a wide range of surface areas. The measured surface areas differed from product specifications, to varying degrees, and between similar products. Findings emphasize the multiple factors that influence surface area and mark its utility in carbon nanomaterial characterization, a prerequisite to understanding their potential applications and toxicities. Implications for occupational monitoring are discussed.

Non-contact temperature measurements for biotechnology discipline working group

NASA Technical Reports Server (NTRS)

Snyder, Robert S.

1988-01-01

In the biotechnology research areas, there is interest in measuring temperature changes over very small dimensions, such as the surface of a 10-micrometer diameter biological cell immersed in cell culture fluid. Non-interference measurements of other properties, such as chemical constituents and their concentrations, are also needed. Contacting probes for pH have recently been developed to penetrate a cell but questions have been raised about their accuracy and net value.

Surface Area Analysis Using the Brunauer-Emmett-Teller (BET) Method: Standard Operating Procedure Series: SOP-C

DTIC Science & Technology

2016-09-01

Method Scientific Operating Procedure Series : SOP-C En vi ro nm en ta l L ab or at or y Jonathon Brame and Chris Griggs September 2016...BET) Method Scientific Operating Procedure Series : SOP-C Jonathon Brame and Chris Griggs Environmental Laboratory U.S. Army Engineer Research and...response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing

Specific surface area of a crushed welded tuff before and after aqueous dissolution

USGS Publications Warehouse

Reddy, M.M.; Claassen, H.C.

1994-01-01

Specific surface areas were measured for several reference minerals (anorthoclase, labradorite and augite), welded tuff and stream sediments from Snowshoe Mountain, near Creede, Colorado. Crushed and sieved tuff had an unexpectedly small variation in specific surface area over a range of size fractions. Replicate surface area measurements of the largest and smallest tuff particle size fractions examined (1-0.3 mm and <0.212 mm) were 2.3 ?? 0.2 m2/g for each size fraction. Reference minerals prepared in the same way as the tuff had smaller specific surface areas than that of the tuff of the same size fraction. Higher than expected tuff specific surface areas appear to be due to porous matrix. Tuff, reacted in solutions with pH values from 2 to 6, had little change in specific surface area in comparison with unreacted tuff. Tuff, reacted with solutions having high acid concentrations (0.1 M hydrochloric acid or sulfuric-hydrofluoric acid), exhibited a marked increase in specific surface area compared to unreacted tuff. ?? 1994.

Potentiometric Surfaces in the Springfield Plateau and Ozark Aquifers of Northwestern Arkansas, Southeastern Kansas, Southwestern Missouri, and Northeastern Oklahoma, 2006

USGS Publications Warehouse

Gillip, Jonathan A.; Czarnecki, John B.; Mugel, Douglas N.

2008-01-01

The Springfield Plateau and Ozark aquifers are important sources of ground water in the Ozark Plateaus aquifer system. Water from these aquifers is used for agricultural, domestic, industrial, and municipal water sources. Changing water use over time in these aquifers presents a need for updated potentiometric-surface maps of the Springfield Plateau and Ozark aquifers. The Springfield Plateau aquifer consists of water-bearing Mississippian-age limestone and chert. The Ozark aquifer consists of Late Cambrian to Middle Devonian age water-bearing rocks consisting of dolostone, limestone, and sandstone. Both aquifers are complex with areally varying lithologies, discrete hydrologic units, varying permeabilities, and secondary permeabilities related to fractures and karst features. During the spring of 2006, ground-water levels were measured in 285 wells. These data, and water levels from selected lakes, rivers, and springs, were used to create potentiometric-surface maps for the Springfield Plateau and Ozark aquifers. Linear kriging was used initially to construct the water-level contours on the maps; the contours were subsequently modified using hydrologic judgment. The potentiometric-surface maps presented in this report represent ground-water conditions during the spring of 2006. During the spring of 2006, the region received less than average rainfall. Dry conditions prior to the spring of 2006 could have contributed to the observed water levels as well. The potentiometric-surface map of the Springfield Plateau aquifer shows a maximum measured water-level altitude within the study area of about 1,450 feet at a spring in Barry County, Missouri, and a minimum measured water-level altitude of 579 feet at a well in Ottawa County, Oklahoma. Cones of depression occur in Dade, Lawrence and Newton Counties in Missouri and Delaware and Ottawa Counties in Oklahoma. These cones of depression are associated with private wells. Ground water in the Springfield Plateau aquifer generally flows to the west in the study area, and to surface features (lakes, rivers, and springs) particularly in the south and east of the study area where the Springfield Plateau aquifer is closest to land surface. The potentiometric-surface map of the Ozark aquifer indicates a maximum measured water-level altitude of 1,303 feet in the study area at a well in Washington County, Arkansas, and a minimum measured water-level altitude of 390 feet in Ottawa County, Oklahoma. The water in the Ozark aquifer generally flows to the northwest in the northern part of the study area and to the west in the remaining study area. Cones of depression occur in Barry, Barton, Cedar, Jasper, Lawrence, McDonald, Newton, and Vernon Counties in Missouri, Cherokee and Crawford Counties in Kansas, and Craig and Ottawa Counties in Oklahoma. These cones of depression are associated with municipal supply wells. The flow directions, based on both potentiometric-surface maps, generally agree with flow directions indicated by previous studies.

Water resources data for Indiana, 1965

USGS Publications Warehouse

,

1965-01-01

The surface-water records for the 1965 water year for gaging stations, partial-record stations, and miscellaneous sites within the State of Indiana are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U.S. Geological Survey, under the direction of Malcolm D. Hale, district engineer, Surface Water Branch. This report marks the beginning of a new method of presenting, annually, basic data on surface-water records by States. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water-supply papers entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Indiana were contained in Parts 3A, 4 and 5 of that series. Beginning with the 1961 water year, streamflow records and related data will be released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports will be limited and primarily for local needs. The records later will be published in Geological Survey water-supply papers at 5-year intervals. These 5-year water-supply papers will show daily discharge and will be compiled on the same geographical areas previously used for the annual series; however, some of the 14 parts of coterminous United States will be further subdivided.

Visualizing diurnal population change in urban areas for emergency management.

PubMed

Kobayashi, Tetsuo; Medina, Richard M; Cova, Thomas J

2011-01-01

There is an increasing need for a quick, simple method to represent diurnal population change in metropolitan areas for effective emergency management and risk analysis. Many geographic studies rely on decennial U.S. Census data that assume that urban populations are static in space and time. This has obvious limitations in the context of dynamic geographic problems. The U.S. Department of Transportation publishes population data at the transportation analysis zone level in fifteen-minute increments. This level of spatial and temporal detail allows for improved dynamic population modeling. This article presents a methodology for visualizing and analyzing diurnal population change for metropolitan areas based on this readily available data. Areal interpolation within a geographic information system is used to create twenty-four (one per hour) population surfaces for the larger metropolitan area of Salt Lake County, Utah. The resulting surfaces represent diurnal population change for an average workday and are easily combined to produce an animation that illustrates population dynamics throughout the day. A case study of using the method to visualize population distributions in an emergency management context is provided using two scenarios: a chemical release and a dirty bomb in Salt Lake County. This methodology can be used to address a wide variety of problems in emergency management.

[Etiological analysis of subambient temperature burn in 351 cases of Hefei area].

PubMed

Shi, Jie; Qi, Weiwei; Xu, Qinglian; Zhou, Shunying; Wang, Guobao

2010-06-01

To study the preventive measure of the subambient temperature burn by analysing the pathogenesis feature. The clinical data were analysed from 351 cases of subambient temperature burn between February 2004 and February 2009, including age, sex, burn season, burn factors, burn position, burn area, burn degree, treatment way, and wound healing. Subambient temperature burn occurred in every age stage. The susceptible age stages included infant, children, and the elderly. Female patients were more than male patients. The common burn reasons were hot-water bottle burn, honey warm keeper burn, and heating device burn. The peak season was winter. Lower limb was the most common site of the subambient temperature burn. The deep II degree to III degree were the most common level, and the burn area was always small, often < or = 1% of total body surface area. Most of patients were treated with changing dressings at clinic and few patients needed hospitalization. Though the surface of wound could heal finally, and the wound healed well with no obvious scar in patients who received operation. Subambient temperature burn is the frequently encountered disease in winter. Use of the warming articles should be cautious, at the same time safety awareness should be strengthened so as to decrease the incidence rate of subambient temperature burn and the injury degree.

Evaluation of an urban land surface scheme over a tropical suburban neighborhood

NASA Astrophysics Data System (ADS)

Harshan, Suraj; Roth, Matthias; Velasco, Erik; Demuzere, Matthias

2017-07-01

The present study evaluates the performance of the SURFEX (TEB/ISBA) urban land surface parametrization scheme in offline mode over a suburban area of Singapore. Model performance (diurnal and seasonal characteristics) is investigated using measurements of energy balance fluxes, surface temperatures of individual urban facets, and canyon air temperature collected during an 11-month period. Model performance is best for predicting net radiation and sensible heat fluxes (both are slightly overpredicted during daytime), but weaker for latent heat (underpredicted during daytime) and storage heat fluxes (significantly underpredicted daytime peaks and nighttime storage). Daytime surface temperatures are generally overpredicted, particularly those containing horizontal surfaces such as roofs and roads. This result, together with those for the storage heat flux, point to the need for a better characterization of the thermal and radiative characteristics of individual urban surface facets in the model. Significant variation exists in model behavior between dry and wet seasons, the latter generally being better predicted. The simple vegetation parametrization used is inadequate to represent seasonal moisture dynamics, sometimes producing unrealistically dry conditions.

Mucoadhesive microparticles with a nanostructured surface for enhanced bioavailability of glaucoma drug.

PubMed

Park, Chun Gwon; Kim, Young Kook; Kim, Mi Jeung; Park, Min; Kim, Myung Hun; Lee, Seung Ho; Choi, Sung Yoon; Lee, Won Seok; Chung, You Jung; Jung, Young Eun; Park, Ki Ho; Choy, Young Bin

2015-12-28

Topical drug administration to the eye is limited by low drug bioavailability due to its rapid clearance from the preocular surface. Thus, multiple daily administrations are often needed, but patient compliance is low, hence a high chance of unsatisfactory treatment of ocular diseases. To resolve this, we propose mucoadhesive microparticles with a nanostructured surface as potential carriers for delivery of brimonidine, an ocular drug for glaucoma treatment. For sustained drug delivery, the microparticles were composed mainly of a diffusion-wall material, poly(lactic-co-glycolic acid) and a mucoadhesive polymer, polyethylene glycol, was used as an additive. Due to their nanostructured surface, the microparticles with a mucoadhesive material exhibited a 13-fold increase in specific surface area and could thus adhere better to the mucous layer on the eye, as compared with the conventional spherical microparticles. When loaded with brimonidine, the mucoadhesive microparticles with a nanostructured surface increased both drug bioavailability and its activity period by a factor of more than 2 over Alphagan P, a marketed eye drop of brimonidine. Copyright © 2015 Elsevier B.V. All rights reserved.

Kansei, surfaces and perception engineering

NASA Astrophysics Data System (ADS)

Rosen, B.-G.; Eriksson, L.; Bergman, M.

2016-09-01

The aesthetic and pleasing properties of a product are important and add significantly to the meaning and relevance of a product. Customer sensation and perception are largely about psychological factors. There has been a strong industrial and academic need and interest for methods and tools to quantify and link product properties to the human response but a lack of studies of the impact of surfaces. In this study, affective surface engineering is used to illustrate and model the link between customer expectations and perception to controllable product surface properties. The results highlight the use of the soft metrology concept for linking physical and human factors contributing to the perception of products. Examples of surface applications of the Kansei methodology are presented from sauna bath, health care, architectural and hygiene tissue application areas to illustrate, discuss and confirm the strength of the methodology. In the conclusions of the study, future research in soft metrology is proposed to allow understanding and modelling of product perception and sensations in combination with a development of the Kansei surface engineering methodology and software tools.

‘Action’ on structured freeform surfaces

NASA Astrophysics Data System (ADS)

Whitehouse, David J.

2018-06-01

Surfaces are becoming more complex partly due to the more complicated function required of them and partly due to the introduction of different manufacturing processes. These have thrown into relief the need to consider new ways of measuring and characterizing such surfaces and more importantly to make such characterization more relevant by tying together the geometry and the function more closely. The surfaces which have freeform and structure have been chosen to be a carrier for this investigation because so far there has been little work carried out in this neglected but potentially important area. This necessitates the development of a strategy for their characterization. In this article, some ways have been found of identifying possible strategies for tackling this characterization problem but also linking this characterization to performance and manufacture, based in part on the principles of least action and on the way that nature has evolved to solve the marriage of flexible freeform geometry, structure and function. Recommendations are made for the most suitable surface parameter to use which satisfies the requirement for characterizing structured freeform surfaces as well as utilizing ‘Action’ to predict functionality.

Surface Water pCO2 Variations and Sea-Air CO2 Fluxes During Summer in the Eastern Canadian Arctic

NASA Astrophysics Data System (ADS)

Burgers, T. M.; Miller, L. A.; Thomas, H.; Else, B. G. T.; Gosselin, M.; Papakyriakou, T.

2017-12-01

Based on a 2 year data set, the eastern Canadian Arctic Archipelago and Baffin Bay appear to be a modest summertime sink of atmospheric CO2. We measured surface water CO2 partial pressure (pCO2), salinity, and temperature throughout northern Baffin Bay, Nares Strait, and Lancaster Sound from the CCGS Amundsen during its 2013 and 2014 summer cruises. Surface water pCO2 displayed considerable variability (144-364 μatm) but never exceeded atmospheric concentrations, and average calculated CO2 fluxes in 2013 and 2014 were -12 and -3 mmol C m-2 d-1 (into the ocean), respectively. Ancillary measurements of chlorophyll a reveal low summertime productivity in surface waters. Based on total alkalinity and stable oxygen isotopes (δ18O) data, a strong riverine signal in northern Nares Strait coincided with relatively high surface pCO2, whereas areas of sea-ice melt occur with low surface pCO2. Further assessments, extending the seasonal observation period, are needed to properly constrain both seasonal and annual CO2 fluxes in this region.

Simulating Lake-Groundwater Interactions During Decadal Climate Cycles: Accounting For Variable Lake Area In The Watershed

NASA Astrophysics Data System (ADS)

Virdi, M. L.; Lee, T. M.

2009-12-01

The volume and extent of a lake within the topo-bathymetry of a watershed can change substantially during wetter and drier climate cycles, altering the interaction of the lake with the groundwater flow system. Lake Starr and other seepage lakes in the permeable sandhills of central Florida are vulnerable to climate changes as they rely exclusively on rainfall and groundwater for inflows in a setting where annual rainfall and recharge vary widely. The groundwater inflow typically arrives from a small catchment area bordering the lake. The sinkhole origin of these lakes combined with groundwater pumping from underlying aquifers further complicate groundwater interactions. Understanding the lake-groundwater interactions and their effects on lake stage over multi-decadal climate cycles is needed to manage groundwater pumping and public expectation about future lake levels. The interdependence between climate, recharge, changing lake area and the groundwater catchment pose unique challenges to simulating lake-groundwater interactions. During the 10-year study period, Lake Starr stage fluctuated more than 13 feet and the lake surface area receded and expanded from 96 acres to 148 acres over drier and wetter years that included hurricanes, two El Nino events and a La Nina event. The recently developed Unsaturated Zone Flow (UZF1) and Lake (LAK7) packages for MODFLOW-2005 were used to simulate the changing lake sizes and the extent of the groundwater catchment contributing flow to the lake. The lake area was discretized to occupy the largest surface area at the highest observed stage and then allowed to change size. Lake cells convert to land cells and receive infiltration as receding lake area exposes the underlying unsaturated zone to rainfall and recharge. The unique model conceptualization also made it possible to capture the dynamic size of the groundwater catchment contributing to lake inflows, as the surface area and volume of the lake changed during the study period. Groundwater flows simulated using daily time steps over a 10-year period were used to describe the relationship between climate, the size of the groundwater catchment, and the relative importance of groundwater inflow to the lake water budget. Modeling approaches used in this study should be applicable to other surface-water bodies such as wetlands and playa lakes. Lake Starr watershed (depressions from sinkholes)

Lp-mixed affine surface area

NASA Astrophysics Data System (ADS)

Wang, Weidong; Leng, Gangsong

2007-11-01

According to the three notions of mixed affine surface area, Lp-affine surface area and Lp-mixed affine surface area proposed by Lutwak, in this article, we give the concept of ith Lp-mixed affine surface area such that the first and second notions of Lutwak are its special cases. Further, some Lutwak's results are extended associated with this concept. Besides, applying this concept, we establish an inequality for the volumes and dual quermassintegrals of a class of star bodies.

Assessing the Increase in Specific Surface Area for Electrospun Fibrous Network due to Pore Induction.

PubMed

Katsogiannis, Konstantinos Alexandros G; Vladisavljević, Goran T; Georgiadou, Stella; Rahmani, Ramin

2016-10-26

The effect of pore induction on increasing electrospun fibrous network specific surface area was investigated in this study. Theoretical models based on the available surface area of the fibrous network and exclusion of the surface area lost due to fiber-to-fiber contacts were developed. The models for calculation of the excluded area are based on Hertzian, Derjaguin-Muller-Toporov (DMT), and Johnson-Kendall-Roberts (JKR) contact models. Overall, the theoretical models correlated the network specific surface area to the material properties including density, surface tension, Young's modulus, Poisson's ratio, as well as network physical properties, such as density and geometrical characteristics including fiber radius, fiber aspect ratio and network thickness. Pore induction proved to increase the network specific surface area up to 52%, compared to the maximum surface area that could be achieved by nonporous fiber network with the same physical properties and geometrical characteristics. The model based on Johnson-Kendall-Roberts contact model describes accurately the fiber-to-fiber contact area under the experimental conditions used for pore generation. The experimental results and the theoretical model based on Johnson-Kendall-Roberts contact model show that the increase in network surface area due to pore induction can reach to up to 58%.

Enhancing fish Underwater Visual Census to move forward assessment of fish assemblages: An application in three Mediterranean Marine Protected Areas

PubMed Central

Thiriet, Pierre; Di Franco, Antonio; Francour, Patrice

2017-01-01

Monitoring fish assemblages is needed to assess whether Marine Protected Areas (MPAs) are meeting their conservation and fisheries management goals, as it allows one to track the progress of recovery of exploited species and associated communities. Underwater Visual Census techniques (UVC) are used to monitor fish assemblages in MPAs. UVCs should be adapted to fish abundance, body-size and behaviour, which can strongly affect fish detectability. In Mediterranean subtidal habitats, however, UVC strip transects of one surface area (25x5 m2) are commonly used to survey the whole fish assemblage, from large shy fish to small crypto-benthic fish. Most high trophic level predators (HTLPs) are large shy fish which rarely swim close to divers and, consequently, their abundance may be under-estimated with commonly used transects. Here, we propose an improvement to traditional transect surveys to better account for differences in behaviour among and within species. First, we compared the effectiveness of combining two transect surface areas (large: 35x20 m2; medium: 25x5 m2) in quantifying large, shy fish within and outside Mediterranean MPAs. We identified species-specific body-size thresholds defining a smaller and a larger size class better sampled by medium and large transects respectively. Combining large and medium transects provided more accurate biomass and species richness estimates for large, shy species than using medium transects alone. We thus combined the new approach with two other transect surface areas commonly used to survey crypto-benthic (10x1 m2) and necto-benthic (25x5 m2) species in order to assess how effectively MPAs protection the whole fish assemblage. We verified that MPAs offer significant protection for HTLPs, their response in terms of biomass and density increase in MPAs was always higher in magnitude than other functional groups. Inside MPAs, the contribution of HTLP reached >25% of total fish biomass, against < 2% outside MPAs. Surveys with multiple transect surface areas allow for a more realistic assessment of the structure of the whole fish assemblage and better assessment of potential recovery of HTLPs within reserves of HTLP. PMID:28594836

Enhancing fish Underwater Visual Census to move forward assessment of fish assemblages: An application in three Mediterranean Marine Protected Areas.

PubMed

Prato, Giulia; Thiriet, Pierre; Di Franco, Antonio; Francour, Patrice

2017-01-01

Monitoring fish assemblages is needed to assess whether Marine Protected Areas (MPAs) are meeting their conservation and fisheries management goals, as it allows one to track the progress of recovery of exploited species and associated communities. Underwater Visual Census techniques (UVC) are used to monitor fish assemblages in MPAs. UVCs should be adapted to fish abundance, body-size and behaviour, which can strongly affect fish detectability. In Mediterranean subtidal habitats, however, UVC strip transects of one surface area (25x5 m2) are commonly used to survey the whole fish assemblage, from large shy fish to small crypto-benthic fish. Most high trophic level predators (HTLPs) are large shy fish which rarely swim close to divers and, consequently, their abundance may be under-estimated with commonly used transects. Here, we propose an improvement to traditional transect surveys to better account for differences in behaviour among and within species. First, we compared the effectiveness of combining two transect surface areas (large: 35x20 m2; medium: 25x5 m2) in quantifying large, shy fish within and outside Mediterranean MPAs. We identified species-specific body-size thresholds defining a smaller and a larger size class better sampled by medium and large transects respectively. Combining large and medium transects provided more accurate biomass and species richness estimates for large, shy species than using medium transects alone. We thus combined the new approach with two other transect surface areas commonly used to survey crypto-benthic (10x1 m2) and necto-benthic (25x5 m2) species in order to assess how effectively MPAs protection the whole fish assemblage. We verified that MPAs offer significant protection for HTLPs, their response in terms of biomass and density increase in MPAs was always higher in magnitude than other functional groups. Inside MPAs, the contribution of HTLP reached >25% of total fish biomass, against < 2% outside MPAs. Surveys with multiple transect surface areas allow for a more realistic assessment of the structure of the whole fish assemblage and better assessment of potential recovery of HTLPs within reserves of HTLP.

Body Surface Area and Baseline Blood Pressure Predict Subclinical Anthracycline Cardiotoxicity in Women Treated for Early Breast Cancer.

PubMed

Kotwinski, Paul; Smith, Gillian; Cooper, Jackie; Sanders, Julie; Ma, Louise; Teis, Albert; Kotwinski, David; Mythen, Michael; Pennell, Dudley J; Jones, Alison; Montgomery, Hugh

2016-01-01

Anthracyclines are highly effective chemotherapeutic agents which may cause long-term cardiac damage (chronic anthracycline cardiotoxicity) and heart failure. The pathogenesis of anthracycline cardiotoxicity remains incompletely understood and individual susceptibility difficult to predict. We sought clinical features which might contribute to improved risk assessment. Subjects were women with early breast cancer, free of pre-existing cardiac disease. Left ventricular ejection fraction was measured using cardiovascular magnetic resonance before and >12 months after anthracycline-based chemotherapy (>3 months post-Trastuzumab). Variables associated with subclinical cardiotoxicity (defined as a fall in left ventricular ejection fraction of ≥5%) were identified by logistic regression. One hundred and sixty-five women (mean age 48.3 years at enrollment) completed the study 21.7 months [IQR 18.0-26.8] after starting chemotherapy. All received anthracyclines (98.8% epirubicin, cumulative dose 400 [300-450] mg/m2); 18% Trastuzumab. Baseline blood pressure was elevated (≥140/90mmHg, mean 147.3/86.1mmHg) in 18 subjects. Thirty-four subjects (20.7%) were identified with subclinical cardiotoxicity, independent predictors of which were the number of anthracycline cycles (odds ratio, OR 1.64 [1.17-2.30] per cycle), blood pressure ≥140/90mmHg (OR 5.36 [1.73-17.61]), body surface area (OR 2.08 [1.36-3.20] per standard deviation (0.16m2) increase), and Trastuzumab therapy (OR 3.35 [1.18-9.51]). The resultant predictive-model had an area under the receiver operating characteristics curve of 0.78 [0.70-0.86]. We found subclinical cardiotoxicity to be common even within this low risk cohort. Risk of cardiotoxicity was associated with modestly elevated baseline blood pressure-indicating that close attention should be paid to blood pressure in patients considered for anthracycline based chemotherapy. The association with higher body surface area suggests that indexing of anthracycline doses to surface area may not be appropriate for all, and points to the need for additional research in this area.

Develop and Test a Solvent Accessible Surface Area-Based Model in Conformational Entropy Calculations

PubMed Central

Wang, Junmei; Hou, Tingjun

2012-01-01

It is of great interest in modern drug design to accurately calculate the free energies of protein-ligand or nucleic acid-ligand binding. MM-PBSA (Molecular Mechanics-Poisson Boltzmann Surface Area) and MM-GBSA (Molecular Mechanics-Generalized Born Surface Area) have gained popularity in this field. For both methods, the conformational entropy, which is usually calculated through normal mode analysis (NMA), is needed to calculate the absolute binding free energies. Unfortunately, NMA is computationally demanding and becomes a bottleneck of the MM-PB/GBSA-NMA methods. In this work, we have developed a fast approach to estimate the conformational entropy based upon solvent accessible surface area calculations. In our approach, the conformational entropy of a molecule, S, can be obtained by summing up the contributions of all atoms, no matter they are buried or exposed. Each atom has two types of surface areas, solvent accessible surface area (SAS) and buried SAS (BSAS). The two types of surface areas are weighted to estimate the contribution of an atom to S. Atoms having the same atom type share the same weight and a general parameter k is applied to balance the contributions of the two types of surface areas. This entropy model was parameterized using a large set of small molecules for which their conformational entropies were calculated at the B3LYP/6-31G* level taking the solvent effect into account. The weighted solvent accessible surface area (WSAS) model was extensively evaluated in three tests. For the convenience, TS, the product of temperature T and conformational entropy S, were calculated in those tests. T was always set to 298.15 K through the text. First of all, good correlations were achieved between WSAS TS and NMA TS for 44 protein or nucleic acid systems sampled with molecular dynamics simulations (10 snapshots were collected for post-entropy calculations): the mean correlation coefficient squares (R2) was 0.56. As to the 20 complexes, the TS changes upon binding, TΔS, were also calculated and the mean R2 was 0.67 between NMA and WSAS. In the second test, TS were calculated for 12 proteins decoy sets (each set has 31 conformations) generated by the Rosetta software package. Again, good correlations were achieved for all decoy sets: the mean, maximum, minimum of R2 were 0.73, 0.89 and 0.55, respectively. Finally, binding free energies were calculated for 6 protein systems (the numbers of inhibitors range from 4 to 18) using four scoring functions. Compared to the measured binding free energies, the mean R2 of the six protein systems were 0.51, 0.47, 0.40 and 0.43 for MM-GBSA-WSAS, MM-GBSA-NMA, MM-PBSA-WSAS and MM-PBSA-NMA, respectively. The mean RMS errors of prediction were 1.19, 1.24, 1.41, 1.29 kcal/mol for the four scoring functions, correspondingly. Therefore, the two scoring functions employing WSAS achieved a comparable prediction performance to that of the scoring functions using NMA. It should be emphasized that no minimization was performed prior to the WSAS calculation in the last test. Although WSAS is not as rigorous as physical models such as quasi-harmonic analysis and thermodynamic integration (TI), it is computationally very efficient as only surface area calculation is involved and no structural minimization is required. Moreover, WSAS has achieved a comparable performance to normal mode analysis. We expect that this model could find its applications in the fields like high throughput screening (HTS), molecular docking and rational protein design. In those fields, efficiency is crucial since there are a large number of compounds, docking poses or protein models to be evaluated. A list of acronyms and abbreviations used in this work is provided for quick reference. PMID:22497310

Disturbance automated reference toolset (DART): Assessing patterns in ecological recovery from energy development on the Colorado Plateau

USGS Publications Warehouse

Nauman, Travis; Duniway, Michael C.; Villarreal, Miguel; Poitras, Travis

2017-01-01

A new disturbance automated reference toolset (DART) was developed to monitor human land surface impacts using soil-type and ecological context. DART identifies reference areas with similar soils, topography, and geology; and compares the disturbance condition to the reference area condition using a quantile-based approach based on a satellite vegetation index. DART was able to represent 26–55% of variation of relative differences in bare ground and 26–41% of variation in total foliar cover when comparing sites with nearby ecological reference areas using the Soil Adjusted Total Vegetation Index (SATVI). Assessment of ecological recovery at oil and gas pads on the Colorado Plateau with DART revealed that more than half of well-pads were below the 25th percentile of reference areas. Machine learning trend analysis of poorly recovering well-pads (quantile < 0.23) had out-of-bag error rates between 37 and 40% indicating moderate association with environmental and management variables hypothesized to influence recovery. Well-pads in grasslands (median quantile [MQ] = 13%), blackbrush (Coleogyne ramosissima) shrublands (MQ = 18%), arid canyon complexes (MQ = 18%), warmer areas with more summer-dominated precipitation, and state administered areas (MQ = 12%) had low recovery rates. Results showcase the usefulness of DART for assessing discrete surface land disturbances, and highlight the need for more targeted rehabilitation efforts at oil and gas well-pads in the arid southwest US.

Disturbance automated reference toolset (DART): Assessing patterns in ecological recovery from energy development on the Colorado Plateau.

PubMed

Nauman, Travis W; Duniway, Michael C; Villarreal, Miguel L; Poitras, Travis B

2017-04-15

A new disturbance automated reference toolset (DART) was developed to monitor human land surface impacts using soil-type and ecological context. DART identifies reference areas with similar soils, topography, and geology; and compares the disturbance condition to the reference area condition using a quantile-based approach based on a satellite vegetation index. DART was able to represent 26-55% of variation of relative differences in bare ground and 26-41% of variation in total foliar cover when comparing sites with nearby ecological reference areas using the Soil Adjusted Total Vegetation Index (SATVI). Assessment of ecological recovery at oil and gas pads on the Colorado Plateau with DART revealed that more than half of well-pads were below the 25th percentile of reference areas. Machine learning trend analysis of poorly recovering well-pads (quantile<0.23) had out-of-bag error rates between 37 and 40% indicating moderate association with environmental and management variables hypothesized to influence recovery. Well-pads in grasslands (median quantile [MQ]=13%), blackbrush (Coleogyne ramosissima) shrublands (MQ=18%), arid canyon complexes (MQ=18%), warmer areas with more summer-dominated precipitation, and state administered areas (MQ=12%) had low recovery rates. Results showcase the usefulness of DART for assessing discrete surface land disturbances, and highlight the need for more targeted rehabilitation efforts at oil and gas well-pads in the arid southwest US. Published by Elsevier B.V.

Long-term studies on the effects of nonvolatile organic compounds on porous media surface areas.

PubMed

Khachikian, Crist S; Harmon, Thomas C

2002-01-01

This paper investigates the long-term behavior of porous media contaminated by nonvolatile organic compounds (NVOC) in terms of specific interfacial surface area. Specifically, a natural sand, Moffett sand (MS), was contaminated with naphthalene and the surface area was measured repeatedly over time using nitrogen adsorption-desorption techniques. A field-contaminated sand affected by lamp-black material (LB) from former manufactured gas plant operations was also studied. Lampblack is a carbonaceous skeleton containing polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons. It is hypothesized that soils contaminated by these types of chemicals will exhibit significantly less surface area than their clean counterparts. The surface areas for the contaminated MS samples increased toward their clean-MS values during the 700-h aging period, but achieved the clean values only after pentane extraction or heating at 60 degrees C. Heating at 50 degrees C failed to achieve a similar recovery of the clean-MS surface area value. Nonspecific mass loss tracked the increase in surface area as indirect evidence that naphthalene loss was the cause of the surface area increase. For the LB samples, aging at 100 degrees C produced a slight decrease in surface area and mass while aging at 250 degrees C caused the surface area to increase roughly threefold while the mass decreased by approximately 1%. These results suggest that, under moderate heating and over the time scale of this investigation, there is a redistribution of the complex contaminant mixture on the solid matrix. Greater temperatures remove mass more efficiently and therefore exhibited the surface area increase expected in this experiment.

The surface area of soil organic matter

USGS Publications Warehouse

Chiou, C.T.; Lee, J.-F.; Boyd, S.A.

1990-01-01

The previously reported surface area for soil organic matter (SOM) of 560-800 m2/g as determined by the ethylene glycol (EG) retention method was reexamined by the standard BET method based on nitrogen adsorption at liquid nitrogen temperature. Test samples consisted of two high organic content soils, a freeze-dried soil humic acid, and an oven-dried soil humic acid. The measured BET areas for these samples were less than 1 m2/g, except for the freeze-dried humic acid. The results suggest that surface adsorption of nonionic organic compounds by SOM is practically insignificant in comparison to uptake by partition. The discrepancy between the surface areas of SOM obtained by BET and EG methods was explained in terms of the 'free surface area' and the 'apparent surface area' associated with these measurements.The previously reported surface area for soil organic matter (SOM) of 560-800 m2/g as determined by the ethylene glycol (EG) retention method was reexamined by the standard BET method based on nitrogen adsorption at liquid nitrogen temperature. Test samples consisted of two high organic content soils, a freeze-dried soil humic acid, and an oven-dried soil humic acid. The measured BET areas for these samples were less than 1 m2/g, except for the freeze-dried humic acid. The results suggest that surface adsorption of nonionic organic compounds by SOM is practically insignificant in comparison to uptake by partition. The discrepancy between the surface areas of SOM obtained by BET and EG methods was explained in terms of the 'free surface area' and the 'apparent surface area' associated with these measurements.

Direct Linearization and Adjoint Approaches to Evaluation of Atmospheric Weighting Functions and Surface Partial Derivatives: General Principles, Synergy and Areas of Application

NASA Technical Reports Server (NTRS)

Ustino, Eugene A.

2006-01-01

This slide presentation reviews the observable radiances as functions of atmospheric parameters and of surface parameters; the mathematics of atmospheric weighting functions (WFs) and surface partial derivatives (PDs) are presented; and the equation of the forward radiative transfer (RT) problem is presented. For non-scattering atmospheres this can be done analytically, and all WFs and PDs can be computed analytically using the direct linearization approach. For scattering atmospheres, in general case, the solution of the forward RT problem can be obtained only numerically, but we need only two numerical solutions: one of the forward RT problem and one of the adjoint RT problem to compute all WFs and PDs we can think of. In this presentation we discuss applications of both the linearization and adjoint approaches

A New Tool for Quality Control

NASA Technical Reports Server (NTRS)

1988-01-01

Diffracto, Ltd. is now offering a new product inspection system that allows detection of minute flaws previously difficult or impossible to observe. Called D-Sight, it represents a revolutionary technique for inspection of flat or curved surfaces to find such imperfections as dings, dents and waviness. System amplifies defects, making them highly visible to simplify decision making as to corrective measures or to identify areas that need further study. CVA 3000 employs a camera, high intensity lamps and a special reflective screen to produce a D- Sight image of light reflected from a surface. Image is captured and stored in a computerized vision system then analyzed by a computer program. A live image of surface is projected onto a video display and compared with a stored master image to identify imperfections. Localized defects measuring less than 1/1000 of an inch are readily detected.

Cardiac mesothelial papillary hyperplasia in four dogs.

PubMed

Kirejczyk, Shannon G; Burnum, Anne L; Brown, Corrie C; Sakamoto, Kaori; Rissi, Daniel R

2018-05-01

Mesothelial papillary hyperplasia (MPH) has been described as an incidental finding on the epicardial surface of clinically normal laboratory Beagle dogs. We describe MPH in 4 dogs diagnosed with acute cardiac tamponade (1 case) or chronic cardiac disease (3 cases). Cardiac MPH appeared as distinct, soft, irregular villous plaques on the epicardial surface of the auricles and occasionally the ventricles. Histologically, areas of MPH were composed of multiple papillary fronds arising from the epicardial surface and projecting into the pericardial space. Fronds were covered by cuboidal and occasionally vacuolated mesothelial cells and were supported by loose fibrovascular stroma with various degrees of edema and inflammation. Although these may represent incidental findings with no clinical significance, the gross appearance warrants differentiation from other conditions. Additional insight into the pathogenesis of MPH is needed to fully understand its significance in the face of concurrent cardiac disease.

Effects of spatial configuration of imperviousness and green infrastructure networks on hydrologic response in a residential sewershed

NASA Astrophysics Data System (ADS)

Lim, Theodore C.; Welty, Claire

2017-09-01

Green infrastructure (GI) is an approach to stormwater management that promotes natural processes of infiltration and evapotranspiration, reducing surface runoff to conventional stormwater drainage infrastructure. As more urban areas incorporate GI into their stormwater management plans, greater understanding is needed on the effects of spatial configuration of GI networks on hydrological performance, especially in the context of potential subsurface and lateral interactions between distributed facilities. In this research, we apply a three-dimensional, coupled surface-subsurface, land-atmosphere model, ParFlow.CLM, to a residential urban sewershed in Washington DC that was retrofitted with a network of GI installations between 2009 and 2015. The model was used to test nine additional GI and imperviousness spatial network configurations for the site and was compared with monitored pipe-flow data. Results from the simulations show that GI located in higher flow-accumulation areas of the site intercepted more surface runoff, even during wetter and multiday events. However, a comparison of the differences between scenarios and levels of variation and noise in monitored data suggests that the differences would only be detectable between the most and least optimal GI/imperviousness configurations.

Surface water records of Texas, 1964

USGS Publications Warehouse

,

1965-01-01

The surface-water records for the 1964 water year for gaging stations, partial-record stations, miscellaneous sites, and base-flow studies within the State of Texas are given in this report. For convenience there are also included records for a few pertinent gaging stations in bordering States. The records were collected and computed by the Water Resources Division of the U. S. Geological Survey, under the direction of Trigg Twichell, district chief, Water Resources Division. Through September 30, 1960, the records of discharge and stage of streams and contents and stage of lakes or reservoirs were published in an annual series of U.S. Geological Survey water supply papers, entitled "Surface Water Supply of the United States." Since 1951 there have been 20 volumes in the series; each volume covered an area whose boundaries coincided with those of certain natural drainage areas. The records in Texas were contained in Parts 7 and 8 of that series. Beginning with the 1961 water year, streamflow records and related data have been released by the Geological Survey in annual reports on a State-boundary basis. Distribution of these basic-data reports is limited and primarily for local needs. Records will be published in Geological Survey water-supply papers at 5-year intervals.

Vertical Structure of Heat and Momentum Transport in the Urban Surface Layer

NASA Astrophysics Data System (ADS)

Hrisko, J.; Ramamurthy, P.

2017-12-01

Vertical transport of heat and momentum during convective periods is investigated in the urban surface layer using eddy covariance measurements at 5 levels. The Obukhov length is used to divide the dataset into distinct stability regimes: weakly unstable, unstable and very unstable. Our preliminary analysis indicates critical differences in the transport of heat and momentum as the instability increases. Particularly, during periods of increased instability the vertical heat flux deviates from surface layer similarity theory. Further analysis of primary quadrant sweeps and ejections also indicate deviations from the theory, alluding that ejections dominate during convective periods for heat transport, but equally contribute with sweeps for momentum transport. The transport efficiencies of momentum at all 5 levels uniformly decreases as the instability increases, in stark contrast the heat transport efficiencies increase non-linearly as the instability increases. Collectively, these results demonstrate the breakdown of similarity theory during convective periods, and reaffirm that revised and improved methods for characterizing heat and momentum transport in urban areas is needed. These implications could ultimately advance weather prediction and estimation of scalar transport for urban areas susceptible to weather hazards and large amounts of pollution.

Low temperature ozone oxidation of solid waste surrogates

NASA Astrophysics Data System (ADS)

Nabity, James A.; Lee, Jeffrey M.

2015-09-01

Solid waste management presents a significant challenge to human spaceflight and especially, long-term missions beyond Earth orbit. A six-month mission will generate over 300 kg of solid wastes per crewmember that must be dealt with to eliminate the need for storage and prevent it from becoming a biological hazard to the crew. There are several methods for the treatment of wastes that include oxidation via ozone, incineration, microbial oxidation or pyrolysis and physical methods such as microwave drying and compaction. In recent years, a low temperature oxidation process using ozonated water has been developed for the chemical conversion of organic wastes to CO2 and H2O. Experiments were conducted to evaluate the rate and effectiveness with which ozone oxidized several different waste materials. Increasing the surface area by chopping or shredding the solids into small pieces more than doubled the rate of oxidation. A greater flow of ozone and agitation of the ozonated water system also increased processing rates. Of the materials investigated, plastics have proven the most difficult to oxidize. The processing of plastics above the glass transition temperatures caused the plastics to clump together which reduced the exposed surface area, while processing at lower temperatures reduced surface reaction kinetics.

Groundwater potential prediction by using geoelectricity method a case study in Simpang Lima and around it

NASA Astrophysics Data System (ADS)

Rahmawati, D. R.; Supriyadi; Aryani, N. P.; Naufal, M. A.

2018-03-01

Water is an important natural resource, which is available both on surface as well as in recharge zone of weathered layer and in various other suitable water reservoir formations/structures below the surface. The study was conducted in Semarang City, Indonesian. Simpang Lima area were chosen since they have geology record of thick alluvium. The condition of Simpang Lima and around it which currently has developed into the main business area in Semarang City. This is marked by the presence like hotels, super market, that is more than one. This condition certainly requires a supply of water for various purposes that support economic efforts in the region. During this time the water needs are met by drilling wells and used as much as possible without taking into account the impact of water utilization. This study aims to determine the zones that have the potential existence of groundwater. The method used is Geoelectric method with Shlumberger configuration in 7 distributed spatial point. The results showed that there is a potential groundwater in eastern Pekunden, Erlanga, behind The Hotel Horizon, and Simpang Lima. Groundwater is found successively at an average depth of 15 meters under earth’s surface.

Real-time continuous nitrate monitoring in Illinois in 2013

USGS Publications Warehouse

Warner, Kelly L.; Terrio, Paul J.; Straub, Timothy D.; Roseboom, Donald; Johnson, Gary P.

2013-01-01

Many sources contribute to the nitrogen found in surface water in Illinois. Illinois is located in the most productive agricultural area in the country, and nitrogen fertilizer is commonly used to maximize corn production in this area. Additionally, septic/wastewater systems, industrial emissions, and lawn fertilizer are common sources of nitrogen in urban areas of Illinois. In agricultural areas, the use of fertilizer has increased grain production to meet the needs of a growing population, but also has resulted in increases in nitrogen concentrations in many streams and aquifers (Dubrovsky and others, 2010). The urban sources can increase nitrogen concentrations, too. The Federal limit for nitrate nitrogen in water that is safe to drink is 10 milligrams per liter (mg/L) (http://water.epa.gov/drink/contaminants/basicinformation/nitrate.cfm, accessed on May 24, 2013). In addition to the concern with nitrate nitrogen in drinking water, nitrogen, along with phosphorus, is an aquatic concern because it feeds the intensive growth of algae that are responsible for the hypoxic zone in the Gulf of Mexico. The largest nitrogen flux to the waters feeding the Gulf of Mexico is from Illinois (Alexander and others, 2008). Most studies of nitrogen in surface water and groundwater include samples for nitrate nitrogen collected weekly or monthly, but nitrate concentrations can change rapidly and these discrete samples may not capture rapid changes in nitrate concentrations that can affect human and aquatic health. Continuous monitoring for nitrate could inform scientists and water-resource managers of these changes and provide information on the transport of nitrate in surface water and groundwater.

Composite materials for precision space reflector panels

NASA Technical Reports Server (NTRS)

Tompkins, Stephen S.; Funk, Joan G.; Bowles, David E.; Towell, Timothy W.; Connell, John W.

1992-01-01

One of the critical technology needs of large precision reflectors for future astrophysical and optical communications satellites lies in the area of structural materials. Results from a materials research and development program at NASA Langley Research Center to provide materials for these reflector applications are discussed. Advanced materials that meet the reflector panel requirements are identified, and thermal, mechanical and durability properties of candidate materials after exposure to simulated space environments are compared. A parabolic, graphite-phenolic honeycomb composite panel having a surface accuracy of 70.8 microinches rms and an areal weight of 1.17 lbm/sq ft was fabricated with T50/ERL1962 facesheets, a PAEI thermoplastic surface film, and Al and SiO(x) coatings.

Cu-modified carbon spheres/reduced graphene oxide as a high sensitivity of gas sensor for NO2 detection at room temperature

NASA Astrophysics Data System (ADS)

Su, Zhibin; Tan, Li; Yang, Ruiqiang; Zhang, Yu; Tao, Jin; Zhang, Nan; Wen, Fusheng

2018-03-01

Nitrogen dioxide (NO2) as one of the most serious air pollution is harmful to people's health, therefore high-performance gas sensors is critically needed. Here, Cu-modified carbon spheres/reduced graphene oxide (Cu@CS/RGO) composite have been prepared as NO2 gas sensor material. Carbon sphere in the interlayer of RGO can increase the specific surface area of RGO. Copper nanoparticles decorated on the surface of CS can effectively enhance the adsorption activity of RGO as supplier of free electrons. The experimental results showed that its particular structure improved the gas sensitivity of RGO at different NO2 concentrations at room temperature.

Engineering Platinum Alloy Electrocatalysts in Nanoscale for PEMFC Application

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

He, Ting

2016-03-01

Fuel cells are expected to be a key next-generation energy source used for vehicles and homes, offering high energy conversion efficiency and minimal pollutant emissions. However, due to large overpotentials on anode and cathode, the efficiency is still much lower than theoretically predicted. During the past decades, considerable efforts have been made to investigate synergy effect of platinum alloyed with base metals. But, engineering the alloy particles in nanoscale has been a challenge. Most important challenges in developing nanostructured materials are the abilities to control size, monodispersity, microcomposition, and even morphology or self-assembly capability, so called Nanomaterials-by-Design, which requires interdisciplinarymore » collaborations among computational modeling, chemical synthesis, nanoscale characterization as well as manufacturing processing. Electrocatalysts, particularly fuel cell catalysts, are dramatically different from heterogeneous catalysts because the surface area in micropores cannot be electrochemically controlled on the same time scale as more transport accessible surfaces. Therefore, electrocatalytic architectures need minimal microporous surface area while maximizing surfaces accessible through mesopores or macropores, and to "pin" the most active, highest performance physicochemical state of the materials even when exposed to thermodynamic forces, which would otherwise drive restructuring, crystallization, or densification of the nanoscale materials. In this presentation, results of engineering nanoscale platinum alloy particles down to 2 ~ 4 nm will be discussed. Based on nature of alloyed base metals, various synthesis technologies have been studied and developed to achieve capabilities of controlling particle size and particle microcomposition, namely, core-shell synthesis, microemulsion technique, thermal decomposition process, surface organometallic chemical method, etc. The results show that by careful engineering the particle size and microcomposition in nanoscale, it is able to achieve superior electrocatalytic activities comparing with traditional preparative methods. Examples to be discussed are high surface area carbon supported Pt, PtM binary, and PtMN ternary alloys, their synthesis processes, characterizations and electrocatalytic activities towards molecular oxygen reduction.« less

Two-dimensional simulation of the June 11, 2010, flood of the Little Missouri River at Albert Pike Recreational Area, Ouachita National Forest, Arkansas

USGS Publications Warehouse

Wagner, Daniel M.

2013-01-01

In the early morning hours of June 11, 2010, substantial flooding occurred at Albert Pike Recreation Area in the Ouachita National Forest of west-central Arkansas, killing 20 campers. The U.S. Forest Service needed information concerning the extent and depth of flood inundation, the water velocity, and flow paths throughout Albert Pike Recreation Area for the flood and for streamflows corresponding to annual exceedence probabilities of 1 and 2 percent. The two-dimensional flow model Fst2DH, part of the Federal Highway Administration’s Finite Element Surface-water Modeling System, and the graphical user interface Surface-water Modeling System (SMS) were used to perform a steady-state simulation of the flood in a 1.5-mile reach of the Little Missouri River at Albert Pike Recreation Area. Peak streamflows of the Little Missouri River and tributary Brier Creek served as inputs to the simulation, which was calibrated to the surveyed elevations of high-water marks left by the flood and then used to predict flooding that would result from streamflows corresponding to annual exceedence probabilities of 1 and 2 percent. The simulated extent of the June 11, 2010, flood matched the observed extent of flooding at Albert Pike Recreation Area. The mean depth of inundation in the camp areas was 8.5 feet in Area D, 7.4 feet in Area C, 3.8 feet in Areas A, B, and the Day Use Area, and 12.5 feet in Lowry’s Camp Albert Pike. The mean water velocity was 7.2 feet per second in Area D, 7.6 feet per second in Area C, 7.2 feet per second in Areas A, B, and the Day Use Area, and 7.6 feet per second in Lowry’s Camp Albert Pike. A sensitivity analysis indicated that varying the streamflow of the Little Missouri River had the greatest effect on simulated water-surface elevation, while varying the streamflow of tributary Brier Creek had the least effect. Simulated water-surface elevations were lower than those modeled by the U.S. Forest Service using the standard-step method, but the comparison between the two was favorable with a mean absolute difference of 0.58 feet in Area C and 0.32 feet in Area D. Results of a HEC-RAS model of the Little Missouri River watershed upstream from the U.S. Geological Survey streamflow-gaging station near Langley showed no difference in mean depth in the areas in common between the models, and a difference in mean velocity of only 0.5 foot per second. Predictions of flooding that would result from streamflows corresponding to annual exceedence probabilities of 1 and 2 percent indicated that the extent of inundation of the June 11, 2010, flood exceeded that of the 1 percent flood, and that for both the 1 and 2 percent floods, all of Areas C and D, and parts of Areas A, B, and the Day Use Area were inundated. Predicted water-surface elevations for the 1 and 2 percent floods were approximately 1 foot lower than those predicted by the U.S. Forest Service using a standard-step model.

Bathymetry of Walker Lake, West-Central Nevada

USGS Publications Warehouse

Lopes, Thomas J.; Smith, J. LaRue

2007-01-01

Walker Lake lies within a topographically closed basin in west-central Nevada and is the terminus of the Walker River. Much of the streamflow in the Walker River is diverted for irrigation, which has contributed to a decline in lake-surface altitude of about 150 feet and an increase in dissolved solids from 2,500 to 16,000 milligrams per liter in Walker Lake since 1882. The increase in salinity threatens the fresh-water ecosystem and survival of the Lahontan cutthroat trout, a species listed as threatened under the Endangered Species Act. Accurately determining the bathymetry and relations between lake-surface altitude, surface area, and storage volume are part of a study to improve the water budget for Walker Lake. This report describes the updated bathymetry of Walker Lake, a comparison of results from this study and a study by Rush in 1970, and an estimate of the 1882 lake-surface altitude. Bathymetry was measured using a single-beam echosounder coupled to a differentially-corrected global positioning system. Lake depth was subtracted from the lake-surface altitude to calculate the altitude of the lake bottom. A Lidar (light detection and ranging) survey and high resolution aerial imagery were used to create digital elevation models around Walker Lake. The altitude of the lake bottom and digital elevation models were merged together to create a single map showing land-surface altitude contours delineating areas that are currently or that were submerged by Walker Lake. Surface area and storage volume for lake-surface altitudes of 3,851.5-4,120 feet were calculated with 3-D surface-analysis software. Walker Lake is oval shaped with a north-south trending long axis. On June 28, 2005, the lake-surface altitude was 3,935.6 feet, maximum depth was 86.3 feet, and the surface area was 32,190 acres. The minimum altitude of the lake bottom from discrete point depths is 3,849.3 feet near the center of Walker Lake. The lake bottom is remarkably smooth except for mounds near the shore and river mouth that could be boulders, tree stumps, logs, or other submerged objects. The echosounder detected what appeared to be mounds in the deepest parts of Walker Lake, miles from the shore and river mouth. However, side-scan sonar and divers did not confirm the presence of mounds. Anomalies occur in two northwest trending groups in northern and southern Walker Lake. It is hypothesized that some anomalies indicate spring discharge along faults based on tufa-like rocks that were observed and the northwest trend parallel to and in proximity of mapped faults. Also, evaporation measured from Walker Lake is about 50 percent more than the previous estimate, indicating more water is flowing into the lake from sources other than the Walker River. Additional studies need to be done to determine what the anomalies are and whether they are related to the hydrology of Walker Lake. Most differences in surface area and storage volume between this study and a study by Rush in 1970 were less than 1 percent. The largest differences occur at lake-surface altitudes less than 3,916 feet. In general, relations between lake-surface altitude, surface area, and storage volume from Rush's study and this study are nearly identical throughout most of the range in lake-surface altitude. The lake-surface altitude in 1882 was estimated to be between 4,080 feet and 4,086 feet with a probable altitude of 4,082 feet. This estimate compares well with two previous estimates of 4,083 feet and 4,086 feet. Researchers believe the historic highstand of Walker Lake occurred in 1868 and estimated the highstand was between 4,089 feet and 4,108 feet. By 1882, Mason Valley was predominantly agricultural. The 7-26 feet decline in lake-surface altitude between 1868 and 1882 could partially be due to irrigation diversions during this time.

Hydrology, nutrient concentrations, and nutrient yields in nearshore areas of four lakes in northern Wisconsin, 1999-2001

USGS Publications Warehouse

Graczyk, David J.; Hunt, Randall J.; Greb, Steven R.; Buchwald, Cheryl A.; Krohelski, James T.

2003-01-01

The effects of shoreline development on water quality and nutrient yields in nearshore areas of four lakes in northern Wisconsin were investigated from October 1999 through September 2001. The study measured surface runoff and ground-water flows from paired developed (sites containing lawn, rooftops, sidewalks, and driveways) and undeveloped (mature and immature woods) catchments adjacent to four lakes in northern Wisconsin. Water samples from surface runoff and ground water were collected and analyzed for nutrients. Coupled with water volumes, loads and subsequent yields of selected constituents were computed for developed and undeveloped catchments. The median runoff from lawn surfaces ranged from 0.0019 to 0.059 inch over the catchment area. Median surface runoff estimates from the wooded catchments were an order of magnitude less than those from the lawn catchments. The increased water volumes from the lawn catchments resulted in greater nutrient loads and subsequent annual nutrient yields from the developed sites. Soil temperature and soil moisture were measured at two sites with mixed lawn and wooded areas. At both of these sites, the area covered with a lawn commonly was warmer than the wooded area. No consistent differences in soil moisture were found. A ground-water model was constructed to simulate the local flow systems at two of the paired catchments. Model simulations showed that much of the ground water delivered to the lake originated from distant areas that did not contribute runoff directly to the lake. Surface runoff and ground-water nutrient concentrations from the lawn and wooded catchments did not have apparent patterns. Some of the median concentrations from lawns were significantly different (at the 0.05 significance level) from those at wooded catchments. Water wells and piezometers were sampled for chemical analyses three times during the study period. Variability in the shallow ground-water chemistry over time in the lawn samples was larger than samples from the wooded areas and upgradient wells. Median nutrient yields in surface runoff from lawns always were greater than those from the wooded catchments. Runoff volumes were the most important factor in determining whether lawns or wooded catchments contribute more nutrients to the lake. The ground-water system had appreciable nutrient concentrations, and are likely an important pathway for nutrient transport to the lake. The nitrate plus nitrite nitrogen and total phosphorus yields to the ground-water system from a lawn catchment were approximately 3 to 4 times greater than those from the wooded catchment. There was no difference in the yields of dissolved inorganic phosphorus to the ground-water system from the lawn and wooded catchments. Study results demonstrate that choosing the appropriate landscape position for locating lawns in sloped areas (specifically, slopes that do not terminate at the lake or areas with intervening flat or buffer zones between lawn and lake) can help reduce the adverse effect of lawns on the shallow ground water and, ultimately, the lake. Additional information would be needed to extrapolate these results to a large drainage area of a lake.

Toward Large-Area Sub-Arcsecond X-Ray Telescopes II

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Allured, Ryan; Ames, Andrew O.; Biskach, Michael P.; Broadway David M.; Bruni, Ricardo J.; Burrows, David; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing;

Unmanned surface traverses of Mars and Moon: Science objectives, payloads, operations

NASA Technical Reports Server (NTRS)

Jaffe, L. D.; Choate, R.

1973-01-01

Science objectives and properties to be measured are outlined for long surface traverse missions on Mars and the Moon, with remotely-controlled roving vehicles. A series of candidate rover payloads is proposed for each planet, varying in weight, cost, purpose, and development needed. The smallest weighs 35 kg; the largest almost 300 kg. A high degree of internal control will be needed on the Mars rover, including the ability to carry out complex science sequences. Decision-making by humans in the Mars mission includes supervisory control of rover operations and selection of features and samples of geological and biological interest. For the lunar mission, less control on the rover and more on earth is appropriate. Science portions of the rover mission profile are outlined, with timelines and mileage breakdowns. Operational problem areas for Mars include control, communications, data storage, night operations, and the mission operations system. For the moon, science data storage on the rover would be unnecessary and control much simpler.

Darrieus wind-turbine and pump performance for low-lift irrigation pumping

NASA Astrophysics Data System (ADS)

Hagen, L. J.; Sharif, M.

1981-10-01

In the Great Plains about 15 percent of the irrigation water pumped on farms comes from surface water sources; for the United States as a whole, the figure is about 22 percent. Because of forecast fuel shortages, there is a need to develop alternative energy sources such as wind power for surface water pumping. Specific objectives of this investigation were to: design and assemble a prototype wind powered pumping system for low lift irrigation pumping; determine performance of the prototype system; design and test an irrigation system using the wind powered prototype in a design and test an farm application; and determine the size combinations of wind turbines, tailwater pits, and temporary storage reservoirs needed for successful farm application of wind powered tailwater pumping systems in western Kansas. The power source selected was a two bladed, 6 m diameter, 9 m tall Darrieus vertical axis wind turbine with 0.10 solidity and 36.1 M(2) swept area.

Effect of Surface Properties on Colloid Retention on Natural and Surrogate Produce Surfaces.

PubMed

Lazouskaya, Volha; Sun, Taozhu; Liu, Li; Wang, Gang; Jin, Yan

2016-12-01

Bacterial contamination of fresh produce is a growing concern in food industry. Pathogenic bacteria can attach to and colonize the surfaces of fresh produce and cause disease outbreaks among consumers. Surface properties of both bacteria and produce affect bacterial contamination; however, the effects of produce roughness, topography, and hydrophobicity on bacterial retention are still poorly understood. In this work, we used spherical polystyrene colloids as bacterial surrogates to investigate colloid retention on and removal (by rinsing) from fresh produce surfaces including tomato, orange, apple, lettuce, spinach, and cantaloupe, and from surrogate produce surface Sharklet (a micro-patterned polymer). All investigated surfaces were characterized in terms of surface roughness and hydrophobicity (including contact angle and water retention area measurements). The results showed that there was no single parameter that dominated colloid retention on fresh produce, yet strong connection was found between colloid retention and water retention and distribution on all the surfaces investigated except apple. Rinsing was generally not efficient in removing colloids from produce surfaces, which suggests the need to modify current cleaning procedures and to develop novel contamination prevention strategies. This work offers a physicochemical approach to a food safety problem and improves understanding of mechanisms leading to produce contamination. © 2016 Institute of Food Technologists®.

Overview of processing activities aimed at higher efficiencies and economical production

NASA Technical Reports Server (NTRS)

Bickler, D. B.

1985-01-01

An overview of processing activities aimed at higher efficiencies and economical production were presented. Present focus is on low-cost process technology for higher-efficiency cells of up to 18% or higher. Process development concerns center on the use of less than optimum silicon sheet, the control of production yields, and making uniformly efficient large-area cells. High-efficiency cell factors that require process development are bulk material perfection, very shallow junction formation, front-surface passivation, and finely detailed metallization. Better bulk properties of the silicon sheet and the keeping of those qualities throughout large areas during cell processing are required so that minority carrier lifetimes are maintained and cell performance is not degraded by high doping levels. When very shallow junctions are formed, the process must be sensitive to metallizatin punch-through, series resisitance in the cell, and control of dopant leaching during surface passivation. There is a need to determine the sensitivity to processing by mathematical modeling and experimental activities.

Dynamic Development of Regional Cortical Thickness and Surface Area in Early Childhood.

PubMed

Lyall, Amanda E; Shi, Feng; Geng, Xiujuan; Woolson, Sandra; Li, Gang; Wang, Li; Hamer, Robert M; Shen, Dinggang; Gilmore, John H

2015-08-01

Cortical thickness (CT) and surface area (SA) are altered in many neuropsychiatric disorders and are correlated with cognitive functioning. Little is known about how these components of cortical gray matter develop in the first years of life. We studied the longitudinal development of regional CT and SA expansion in healthy infants from birth to 2 years. CT and SA have distinct and heterogeneous patterns of development that are exceptionally dynamic; overall CT increases by an average of 36.1%, while cortical SA increases 114.6%. By age 2, CT is on average 97% of adult values, compared with SA, which is 69%. This suggests that early identification, prevention, and intervention strategies for neuropsychiatric illness need to be targeted to this period of rapid postnatal brain development, and that SA expansion is the principal driving factor in cortical volume after 2 years of age. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The Relationship of the Anthropometric Variables to the Infusion Rate of Rocuronium in the Elderly

PubMed Central

Koo, Bon Nyeo; Bai, Sun Jun; Lee, Woo Chang

2005-01-01

We have determined the infusion rates of rocuronium in the elderly and young adult patients during sevoflurane and nitrous oxide anesthesia. The correlation of some anthropometric predictors with infusion rate of rocuronium was also investigated for both elderly and young adult. Participating patients were assigned to one of two groups: 1) young adult patients aged 20 to 50 years (n = 30); 2) elderly patients aged over 65 years (n = 30). The anthropometric variables such as height, weight, ratio of weight to body surface area, subscapularis and suprailiac skin folds, body surface area, body mass index and % ideal body weight were evaluated as predictors for infusion rate. The infusion rate in elderly patients was significantly less compared with that in young adult patients (p < 0.05). In elderly patients, no anthropometric predictor was related to the infusion rate of rocuronium. This suggests that the infusion rate of rocuronium for an elderly patient needs to be individualized by monitoring neuromuscular transmission to avoid excessive dose. PMID:16259061

Cryogenic and Simulated Fuel Jet Breakup in Argon, Helium and Nitrogen Gas Flows

NASA Technical Reports Server (NTRS)

Ingebo, Robert D.

1995-01-01

Two-phase flow atomization of liquid nitrogen jets was experimentally investigated. They were co-axially injected into high-velocity gas flows of helium, nitrogen and argon, respectively, and atomized internally inside a two-fluid fuel nozzle. Cryogenic sprays with relatively high specific surface areas were produced, i.e., ratios of surface area to volume were fairly high. This was indicated by values of reciprocal Sauter mean diameters, RSMD's, as measured with a scattered- light scanning instrument developed at NASA Lewis Research Center. Correlating expressions were derived for the three atomizing gases over a gas temperature range of 111 to 422 K. Also, the correlation was extended to include waterjet breakup data that had been previously obtained in simulating fuel jet breakup in sonic velocity gas flow. The final correlating expression included a new dimensionless molecular-scale acceleration group. It was needed to correlate RSMD data, for LN2 and H2O sprays, with the fluid properties of the liquid jets and atomizing gases used in this investigation.

A review of visual cues associated with food on food acceptance and consumption.

PubMed

Wadhera, Devina; Capaldi-Phillips, Elizabeth D

2014-01-01

Several sensory cues affect food intake including appearance, taste, odor, texture, temperature, and flavor. Although taste is an important factor regulating food intake, in most cases, the first sensory contact with food is through the eyes. Few studies have examined the effects of the appearance of a food portion on food acceptance and consumption. The purpose of this review is to identify the various visual factors associated with food such as proximity, visibility, color, variety, portion size, height, shape, number, volume, and the surface area and their effects on food acceptance and consumption. We suggest some ways that visual cues can be used to increase fruit and vegetable intake in children and decrease excessive food intake in adults. In addition, we discuss the need for future studies that can further establish the relationship between several unexplored visual dimensions of food (specifically shape, number, size, and surface area) and food intake. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Overview of the NASA Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Kellas, Sotiris; Fuchs, Yvonne T.

2009-01-01

This paper provides an overview of rotorcraft crashworthiness research being conducted at NASA Langley Research Center under sponsorship of the Subsonic Rotary Wing (SRW) Aeronautics Program. The research is focused in two areas: development of an externally deployable energy attenuating concept and improved prediction of rotorcraft crashworthiness. The deployable energy absorber (DEA) is a composite honeycomb structure, with a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed for deployment. The capabilities of the DEA have been demonstrated through component crush tests and vertical drop tests of a retrofitted fuselage section onto different surfaces or terrain. The research on improved prediction of rotorcraft crashworthiness is focused in several areas including simulating occupant responses and injury risk assessment, predicting multi-terrain impact, and utilizing probabilistic analysis methods. A final task is to perform a system-integrated simulation of a full-scale helicopter crash test onto a rigid surface. A brief description of each research task is provided along with a summary of recent accomplishments.

Overview of the NASA Subsonic Rotary Wing Aeronautics Research Program in Rotorcraft Crashworthiness

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fuchs, Yvonne T.; Kellas, Sotiris

2008-01-01

This paper provides an overview of rotorcraft crashworthiness research being conducted at NASA Langley Research Center under sponsorship of the Subsonic Rotary Wing (SRW) Aeronautics Program. The research is focused in two areas: development of an externally deployable energy attenuating concept and improved prediction of rotorcraft crashworthiness. The deployable energy absorber (DEA) is a composite honeycomb structure, with a unique flexible hinge design that allows the honeycomb to be packaged and remain flat until needed for deployment. The capabilities of the DEA have been demonstrated through component crush tests and vertical drop tests of a retrofitted fuselage section onto different surfaces or terrain. The research on improved prediction of rotorcraft crashworthiness is focused in several areas including simulating occupant responses and injury risk assessment, predicting multi-terrain impact, and utilizing probabilistic analysis methods. A final task is to perform a system-integrated simulation of a full-scale helicopter crash test onto a rigid surface. A brief description of each research task is provided along with a summary of recent accomplishments.

A citrus waste-based biorefinery as a source of renewable energy: technical advances and analysis of engineering challenges.

PubMed

Rivas-Cantu, Raul C; Jones, Kim D; Mills, Patrick L

2013-04-01

An assessment of recent technical advances on pretreatment processes and its effects on enzymatic hydrolysis as the main steps of a proposed citrus processing waste (CPW) biorefinery is presented. Engineering challenges and relevant gaps in scientific and technical information for reliable design, modeling and scale up of a CPW biorefinery are also discussed. Some integrated physico-chemical pretreatments are proposed for testing for CPW, including high speed knife-grinding and simultaneous caustic addition. These new proposed processes and the effect of parameters such as particle size, surface area and morphology, pore volume and chemical composition of the diverse fractions resulting from pretreatment and enzymatic hydrolysis need to be evaluated and compared for pretreated and untreated samples of grapefruit processing waste. This assessment suggests the potential for filling the data gaps, and preliminary results demonstrate that the reduction of particle size and the increased surface area for the CPW will result in higher reaction rates and monosaccharide yields for the pretreated waste material.

Characteristics of cellulose-microalgae composite

NASA Astrophysics Data System (ADS)

Hwang, Kyo-Jung; Kwon, Gu-Joong; Yang, Ji-Wook; Kim, Sung-yeol; Kim, Dae-Young

2017-10-01

The composites were prepared in order of mixing the cellulose with the N. commune, dissolution-regeneration procedure by LiOH/Urea aqueous solution and freeze-drying. Before the freeze-drying, internal pores of the composites were substituted with an organic solvent. SEM analysis showed that the increase of N. commune results in blockage of cellulose network structure. Brunauer-Emmett-Teller (BET) surface area analysis showed the decrease of mesopore and macropore as the N. commune ratio increases, also the decrease of the specific surface area was shown. The composites appear to have different thermogravimetric analysis properties with the pure N. commune or cellulose itself. Fourier transform infrared spectroscopy (FT-IR) spectra of the composites have specific peaks of the cellulose and N. commune, and increase of N. commune ratio results broadening of peaks relevant to proteins, lipids, and fatty acids. The composites showed higher adsorptivity as the N. commune ratio increases. Especially, the adsorptivity was higher than active carbon before 120 minutes of adsorption. The composite is expected to be used for the situations which need urgent adsorption.

Ecotoxicological studies of environmental samples from Buenos Aires area using a standardized amphibian embryo toxicity test (AMPHITOX).

PubMed

Herkovits, Jorge; Perez-Coll, Cristina; Herkovits, Francisco D

2002-01-01

The toxicity of 34 environmental samples from potentially polluted and reference stations were evaluated by means of the AMPHITOX test from acute to chronic exposure according to the toxicity found in each sample. The samples were obtained from surface and ground water, leaches, industrial effluents and soils. The data, expressed in acute, short-term chronic and chronic Toxicity Units (TUa, TUstc and TUc) resulted in a maximal value of 1000 TUc, found in a leach, while the lower toxicity value was 1.4 TUa corresponding to two surface water samples. In five samples (four providing from reference places) no toxicity was detected. The results point out the possibility of evaluating the toxicity of a wide diversity of samples by means of AMPHITOX as a customized toxicity test. The fact that almost all samples with suspected toxicity in rivers and streams from the Metropolitan area of Buenos Aires city resulted toxic, indicates the need of enhanced stewardship of chemical substances for environmental and human health protection purposes.

The flaming gypsy skirt injury.

PubMed

Leong, S C L; Emecheta, I E; James, M I

2007-01-01

On review of admissions over a 12-month period, we noted a significant number of women presenting with gypsy skirt burns. We describe all six cases to highlight the unique distribution of the wounds and the circumstances in which the accidents occurred. Four skirts were ignited by open fire heaters: two skirts ignited whilst the women were standing nearby, distracted with a telephone conversation; one brushed over the flame as she was walking past the heater; other whilst dancing in the lounge. One skirt was ignited by decorative candles placed on the floor during a social gathering. Another skirt was set alight by cigarette ember, whilst smoking in the toilet. Percentage surface area burned, estimated according to the rule of nines, showed that gypsy skirt burns were significant ranging from 7 to 14% total body surface area (TBSA) and averaging 9% TBSA. Two patients required allogenic split-skin grafts. Common sense care with proximity to naked flame is all that is needed to prevent this injury.

Dynamics of fingertip contact during the onset of tangential slip

PubMed Central

Delhaye, Benoit; Lefèvre, Philippe; Thonnard, Jean-Louis

2014-01-01

Through highly precise perceptual and sensorimotor activities, the human tactile system continuously acquires information about the environment. Mechanical interactions between the skin at the point of contact and a touched surface serve as the source of this tactile information. Using a dedicated custom robotic platform, we imaged skin deformation at the contact area between the finger and a flat surface during the onset of tangential sliding movements in four different directions (proximal, distal, radial and ulnar) and with varying normal force and tangential speeds. This simple tactile event evidenced complex mechanics. We observed a reduction of the contact area while increasing the tangential force and proposed to explain this phenomenon by nonlinear stiffening of the skin. The deformation's shape and amplitude were highly dependent on stimulation direction. We conclude that the complex, but highly patterned and reproducible, deformations measured in this study are a potential source of information for the central nervous system and that further mechanical measurement are needed to better understand tactile perceptual and motor performances. PMID:25253033

Features of Protein-Protein Interactions that Translate into Potent Inhibitors: Topology, Surface Area and Affinity

PubMed Central

Smith, Matthew C.; Gestwicki, Jason E.

2013-01-01

Protein-protein interactions (PPIs) control the assembly of multi-protein complexes and, thus, these contacts have enormous potential as drug targets. However, the field has produced a mix of both exciting success stories and frustrating challenges. Here, we review known examples and explore how the physical features of a PPI, such as its affinity, hotspots, off-rates, buried surface area and topology, may influence the chances of success in finding inhibitors. This analysis suggests that concise, tight binding PPIs are most amenable to inhibition. However, it is also clear that emerging technical methods are expanding the repertoire of “druggable” protein contacts and increasing the odds against difficult targets. In particular, natural product-like compound libraries, high throughput screens specifically designed for PPIs and approaches that favor discovery of allosteric inhibitors appear to be attractive routes. The first group of PPI inhibitors has entered clinical trials, further motivating the need to understand the challenges and opportunities in pursuing these types of targets. PMID:22831787

Nano-plastics in the aquatic environment.

PubMed

Mattsson, K; Hansson, L-A; Cedervall, T

2015-10-01

The amount of plastics released to the environment in modern days has increased substantially since the development of modern plastics in the early 1900s. As a result, concerns have been raised by the public about the impact of plastics on nature and on, specifically, aquatic wildlife. Lately, much attention has been paid to macro- and micro-sized plastics and their impact on aquatic organisms. However, micro-sized plastics degrade subsequently into nano-sizes whereas nano-sized particles may be released directly into nature. Such particles have a different impact on aquatic organisms than larger pieces of plastic due to their small size, high surface curvature, and large surface area. This review describes the possible sources of nano-sized plastic, its distribution and behavior in nature, the impact of nano-sized plastic on the well-being of aquatic organisms, and the difference of impact between nano- and micro-sized particles. We also identify research areas which urgently need more attention and suggest experimental methods to obtain useful data.

Selective-area growth and controlled substrate coupling of transition metal dichalcogenides

NASA Astrophysics Data System (ADS)

Bersch, Brian M.; Eichfeld, Sarah M.; Lin, Yu-Chuan; Zhang, Kehao; Bhimanapati, Ganesh R.; Piasecki, Aleksander F.; Labella, Michael, III; Robinson, Joshua A.

2017-06-01

Developing a means for true bottom-up, selective-area growth of two-dimensional (2D) materials on device-ready substrates will enable synthesis in regions only where they are needed. Here, we demonstrate seed-free, site-specific nucleation of transition metal dichalcogenides (TMDs) with precise control over lateral growth by utilizing an ultra-thin polymeric surface functionalization capable of precluding nucleation and growth. This polymer functional layer (PFL) is derived from conventional photoresists and lithographic processing, and is compatible with multiple growth techniques, precursors (metal organics, solid-source) and TMDs. Additionally, we demonstrate that the substrate can play a major role in TMD transport properties. With proper TMD/substrate decoupling, top-gated field-effect transistors (FETs) fabricated with selectively-grown monolayer MoS2 channels are competitive with current reported MoS2 FETs. The work presented here demonstrates that substrate surface engineering is key to realizing precisely located and geometrically-defined 2D layers via unseeded chemical vapor deposition techniques.

Supercritical fluid attachment of palladium nanoparticles on aligned carbon nanotubes.

PubMed

Ye, Xiang-Rong; Lin, Yuehe; Wai, Chien M; Talbot, Jan B; Jin, Sungho

2005-06-01

Nanocomposite materials consisting of Pd nanoparticles deposited on aligned multi-walled carbon nanotubes have been fabricated through hydrogen reduction of palladium-beta-diketone precursor in supercritical carbon dioxide. The supercritical fluid processing allowed deposition of high-density Pd nanoparticles (approximately 5-10 nm) on both as-grown (unfunctionalized) and functionalized (using HNO3 oxidation) nanotubes. However, the wet processing for functionalization results in pre-agglomerated, bundle-shaped nanotubes, thus significantly reducing the effective surface area for Pd particle deposition, although the bundling provides more secure, lock-in-place positioning of nanotubes and Pd catalyst particles. The nanotube bundling is substantially mitigated by Pd nanoparticle deposition on the unfunctionalized and geometrically separated nanotubes, which provides much higher catalyst surface area. Such nanocomposite materials utilizing geometrically secured and aligned nanotubes can be useful for providing much enhanced catalytic activities to chemical and electrochemical reactions (e.g., fuel cell reactions), and eliminate the need for tedious catalyst recovery process after the reaction is completed.

Surface-mediated molecular events in material-induced blood-plasma coagulation

NASA Astrophysics Data System (ADS)

Chatterjee, Kaushik

Coagulation and thrombosis persist as major impediments associated with the use of blood-contacting medical devices. We are investigating the molecular mechanism underlying material-induced blood-plasma coagulation focusing on the role of the surface as a step towards prospective development of improved hemocompatible biomaterials. A classic observation in hematology is that blood/blood-plasma in contact with clean glass surface clots faster than when in contact with many plastic surfaces. The traditional biochemical theory explaining the underlying molecular mechanism suggests that hydrophilic surfaces, like that of glass, are specific activators of the coagulation cascade because of the negatively-charged groups on the surface. Hydrophobic surfaces are poor procoagulants or essentially "benign" because they lack anionic groups. Further, these negatively-charged surfaces are believed to not only activate blood factor XII (FXII), the key protein in contact activation, but also play a cofactor role in the amplification and propagation reactions that ultimately lead to clot formation. In sharp contrast to the traditional theory, our investigations indicate a need for a paradigm shift in the proposed sequence of contact activation events to incorporate the role of protein adsorption at the material surfaces. These studies have lead to the central hypothesis for this work proposing that protein adsorption to hydrophobic surfaces attenuates the contact activation reactions so that poorly-adsorbent hydrophilic surfaces appear to be stronger procoagulants relative to hydrophobic surfaces. Our preliminary studies measuring the plasma coagulation response of activated FXII (FXIIa) on different model surfaces suggested that the material did not play a cofactor role in the processing of this enzyme dose through the coagulation pathway. Therefore, we focused our efforts on studying the mechanism of initial production of enzyme at the procoagulant surface. Calculations for the amounts of FXIIa generated at material surfaces in plasma using a mathematical model for measured coagulation responses indicate that the relative contributions of the individual pathways of enzyme generation are similar at both hydrophilic and hydrophobic surfaces, only the amounts of enzyme generated scale with surface energy and area of the activating surface. Further, from direct measurement of enzyme activation at test surfaces we observed that contact activation reactions are not specific to negatively-charged hydrophilic surfaces. Rather, the molecular interactions are attenuated at hydrophobic surfaces due to protein adsorption so that poorly-adsorbent hydrophilic surfaces exhibit an apparent specificity for contact activation reactions. Preliminary studies were preformed to assay the plasma coagulation response to low-fouling surfaces prepared by either grafting poly(ethylene glycol) chains or using zwitterions. Results indicate that poly(ethylene glycol)-modified surfaces are significantly weaker procoagulants than surfaces containing zwitterions underscoring a need to specifically evaluate the coagulation response despite similarities in observed protein adsorption to both surfaces. In summary, our studies demonstrate a need to incorporate protein-adsorption competition at procoagulant surfaces into the mechanism of contact activation to account for the observed moderation of FXII activation by blood proteins unrelated to the plasma coagulation cascade.

Feasibility of high recovery highwall mining equipment. Final report

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

Not Available

1981-01-01

Three equipment systems exhibited significant promise: the RSV Miner, a surface longwall using standard underground equipment, and the variable angle auger. Other equipment systems showing considerable merit were the surface shortwall, and the two extended depth augers. Of the three most significant systems, the RSV Miner exhibits the greatest versatility and adaptability. It may be used competently in many surface mining applications and readily adapts to geologic anomalies and changing seam heights. The machine employs steering and guidance equipment and provides the necessary capabilities for extended depth operation. Safety is good, as no men are required to work underground. However,more » most important is the system's recovery factor of approximately 75% to 80% of the in-situ coal reserve within reach. The surface longwall system using standard underground equipment (preferably a ranging drum shearer in conjunction with shield supports) is most suited to either a trench mining or a modified area mining application. Both applications would allow the length of the face to be held constant. Another important consideration is legal requirements for a tailgate entry, which would necessitate additional equipment for development in a modified area mining application. When compared to surface shortwall, surface longwall exhibits higher productivity, a far greater equipment selection which allows system tailoring to geologic conditions, and greater roof control due to the significantly smaller section of overburden that must be supported. Recovery should approach, and possibly exceed, 90% of the coal in-place. The variable angle auger, which is currently only a concept, fills a very real need for which no other equipment is available at this time.« less

Blood pressure cuffs as a vector for transmission of multi-resistant organisms: colonisation rates and effects of disinfection.

PubMed

Grewal, Harjeet; Varshney, Kavita; Thomas, Lee C; Kok, Jen; Shetty, Amith

2013-06-01

Blood pressure (BP) cuffs are potential vectors for transmission of multi-resistant organisms (MROs). The present study aims to determine MRO colonisation rates in BP cuffs from areas of high patient flow as an assessment of the quality of disinfection and infection control practices. BP cuffs in the ED, high dependency unit (HDU) and operating theatres (OT) were prospectively examined after routine disinfection procedures. Swabs collected from the inner and outer surfaces of BP cuffs during inter-patient intervals were plated onto replicate organism detection and counting, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) chromogenic agar plates to detect rates of bacterial, MRSA and VRE colonisation, respectively. High bacterial colonisation rates were detected in BP cuffs from all three areas. BP cuffs from OT were significantly less colonised compared with cuffs from HDU and ED; 76% versus 96% and 100% (P < 0.0001) for inner surfaces and 86% versus 98% and 100% (P < 0.0001) for outer surfaces, respectively. Equivalent or higher bacterial growth was observed on the inner surface compared with outer surface in 54%, 84% and 86% of BP cuffs from OT, HDU and ED, respectively. MRSA was detected in 3 of 150 (2%) swabs collected, but no VRE was detected. Although MRSA and VRE were infrequently isolated, current disinfection and infection control protocols need to be improved given the greater recovery of organisms from the inner compared with outer surfaces of BP cuffs. © 2013 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Surface conductance of graphene from non-contact resonant cavity.

PubMed

Obrzut, Jan; Emiroglu, Caglar; Kirillov, Oleg; Yang, Yanfei; Elmquist, Randolph E

2016-06-01

A method is established to reliably determine surface conductance of single-layer or multi-layer atomically thin nano-carbon graphene structures. The measurements are made in an air filled standard R100 rectangular waveguide configuration at one of the resonant frequency modes, typically at TE 103 mode of 7.4543 GHz. Surface conductance measurement involves monitoring a change in the quality factor of the cavity as the specimen is progressively inserted into the cavity in quantitative correlation with the specimen surface area. The specimen consists of a nano-carbon-layer supported on a low loss dielectric substrate. The thickness of the conducting nano-carbon layer does not need to be explicitly known, but it is assumed that the lateral dimension is uniform over the specimen area. The non-contact surface conductance measurements are illustrated for a typical graphene grown by chemical vapor deposition process, and for a high quality monolayer epitaxial graphene grown on silicon carbide wafers for which we performed non-gated quantum Hall resistance measurements. The sequence of quantized transverse Hall resistance at the Landau filling factors ν = ±6 and ±2, and the absence of the Hall plateau at ν = 4 indicate that the epitaxially grown graphene is a high quality mono-layer. The resonant microwave cavity measurement is sensitive to the surface and bulk conductivity, and since no additional processing is required, it preserves the integrity of the conductive graphene layer. It allows characterization with high speed, precision and efficiency, compared to transport measurements where sample contacts must be defined and applied in multiple processing steps.

City of Flagstaff Project: Ground Water Resource Evaluation, Remote Sensing Component

USGS Publications Warehouse

Chavez, Pat S.; Velasco, Miguel G.; Bowell, Jo-Ann; Sides, Stuart C.; Gonzalez, Rosendo R.; Soltesz, Deborah L.

1996-01-01

Many regions, cities, and towns in the Western United States need new or expanded water resources because of both population growth and increased development. Any tools or data that can help in the evaluation of an area's potential water resources must be considered for this increasingly critical need. Remotely sensed satellite images and subsequent digital image processing have been under-utilized in ground water resource evaluation and exploration. Satellite images can be helpful in detecting and mapping an area's regional structural patterns, including major fracture and fault systems, two important geologic settings for an area's surface to ground water relations. Within the United States Geological Survey's (USGS) Flagstaff Field Center, expertise and capabilities in remote sensing and digital image processing have been developed over the past 25 years through various programs. For the City of Flagstaff project, this expertise and these capabilities were combined with traditional geologic field mapping to help evaluate ground water resources in the Flagstaff area. Various enhancement and manipulation procedures were applied to the digital satellite images; the results, in both digital and hardcopy format, were used for field mapping and analyzing the regional structure. Relative to surface sampling, remotely sensed satellite and airborne images have improved spatial coverage that can help study, map, and monitor the earth surface at local and/or regional scales. Advantages offered by remotely sensed satellite image data include: 1. a synoptic/regional view compared to both aerial photographs and ground sampling, 2. cost effectiveness, 3. high spatial resolution and coverage compared to ground sampling, and 4. relatively high temporal coverage on a long term basis. Remotely sensed images contain both spectral and spatial information. The spectral information provides various properties and characteristics about the surface cover at a given location or pixel (that is, vegetation and/or soil type). The spatial information gives the distribution, variation, and topographic relief of the cover types from pixel to pixel. Therefore, the main characteristics that determine a pixel's brightness/reflectance and, consequently, the digital number (DN) assigned to the pixel, are the physical properties of the surface and near surface, the cover type, and the topographic slope. In this application, the ability to detect and map lineaments, especially those related to fractures and faults, is critical. Therefore, the extraction of spatial information from the digital images was of prime interest in this project. The spatial information varies among the different spectral bands available; in particular, a near infrared spectral band is better than a visible band when extracting spatial information in highly vegetated areas. In this study, both visible and near infrared bands were analyzed and used to extract the desired spatial information from the images. The wide swath coverage of remotely sensed satellite digital images makes them ideal for regional analysis and mapping. Since locating and mapping highly fractured and faulted areas is a major requirement for ground water resource evaluation and exploration this aspect of satellite images was considered critical; it allowed us to stand back (actually up about 440 miles), look at, and map the regional structural setting of the area. The main focus of the remote sensing and digital image processing component of this project was to use both remotely sensed digital satellite images and a Digital Elevation Model (DEM) to extract spatial information related to the structural and topographic patterns in the area. The data types used were digital satellite images collected by the United States' Landsat Thematic Mapper (TM) and French Systeme Probatoire d'Observation de laTerre (SPOT) imaging systems, along with a DEM of the Flagstaff region. The USGS Mini Image Processing Sy

Land Use and Land Cover (LULC) Change Detection in Islamabad and its Comparison with Capital Development Authority (CDA) 2006 Master Plan

NASA Astrophysics Data System (ADS)

Hasaan, Zahra

2016-07-01

Remote sensing is very useful for the production of land use and land cover statistics which can be beneficial to determine the distribution of land uses. Using remote sensing techniques to develop land use classification mapping is a convenient and detailed way to improve the selection of areas designed to agricultural, urban and/or industrial areas of a region. In Islamabad city and surrounding the land use has been changing, every day new developments (urban, industrial, commercial and agricultural) are emerging leading to decrease in vegetation cover. The purpose of this work was to develop the land use of Islamabad and its surrounding area that is an important natural resource. For this work the eCognition Developer 64 computer software was used to develop a land use classification using SPOT 5 image of year 2012. For image processing object-based classification technique was used and important land use features i.e. Vegetation cover, barren land, impervious surface, built up area and water bodies were extracted on the basis of object variation and compared the results with the CDA Master Plan. The great increase was found in built-up area and impervious surface area. On the other hand vegetation cover and barren area followed a declining trend. Accuracy assessment of classification yielded 92% accuracies of the final land cover land use maps. In addition these improved land cover/land use maps which are produced by remote sensing technique of class definition, meet the growing need of legend standardization.

Future space development scenarios: Environmental considerations

NASA Technical Reports Server (NTRS)

Tangum, Richard

1992-01-01

The formation of positive attitudes and values concerning the environment of space, as the basis for assuming a wise stewardship role, is becoming increasingly important as many nations begin their journeys into space. A strong emphasis should be placed on fostering an international space environmental ethics. The object of environmental assessment and management in space should be to define what interplanetary regulatory procedures are needed to avoid unnecessary environmental damage and to monitor the effectiveness of such avoidance. The first requirement for research is to narrow the field of concern to areas where there could be an increased scale of development in space in the immediate future. Research needs to be focused on methodologies for defining the environmental systems involved (e.g., the lunar surface) and then recognizing key variables in the system that are fragile and need to be respected. Criteria for environmental quality should emerge which identify, in the case of lunar surface, how much mining activity can be safely undertaken and what quantity of exhaust gases can be released over a given period of time. Only then will humans be most able to evaluate the likely consequences of ventures into space.

Determination of the Volume of Water for Suppressing the Thermal Decomposition of Forest Combustibles

NASA Astrophysics Data System (ADS)

Volkov, R. S.; Zhdanova, A. O.; Kuznetsov, G. V.; Strizhak, P. A.

2017-07-01

From the results of experimental studies of the processes of suppressing the thermal decomposition of the typical forest combustibles (birch leaves, fir needles, asp twigs, and a mixture of these three materials) by water aerosol, the minimum volumes of the fire-extinguishing liquid have been determined (by varying the volume of samples of the forest combustibles from 0.00002 m3 to 0.0003 m3 and the area of their open surface from 0.0001 m2 to 0.018 m2). The dependences of the minimum volume of water on the area of the open surface of the forest combustible have been established. Approximation expressions for these dependences have been obtained. Forecast has been made of the minimum volume of water for suppressing the process of thermal decomposition of forest combustibles in areas from 1 cm2 to 1 km2, as well as of the characteristic quenching times by varying the water concentration per unit time. It has been shown that the amount of water needed for effective suppression of the process of thermal decomposition of forest combustibles is several times less than is customarily assumed.

Feasibility study for locating archaeological village sites by satellite remote sensing techniques. [multispectral photography of Alaska

NASA Technical Reports Server (NTRS)

Cook, J. P. (Principal Investigator); Stringer, W. J.

1974-01-01

The author has identified the following significant results. The objective is to determine the feasibility of detecting large Alaskan archaeological sites by satellite remote sensing techniques and mapping such sites. The approach used is to develop digital multispectral signatures of dominant surface features including vegetation, exposed soils and rock, hydrological patterns and known archaeological sites. ERTS-1 scenes are then printed out digitally in a map-like array with a letter reflecting the most appropriate classification representing each pixel. Preliminary signatures were developed and tested. It was determined that there was a need to tighten up the archaeological site signature by developing accurate signatures for all naturally-occurring vegetation and surface conditions in the vicinity of the test area. These second generation signatures have been tested by means of computer printouts and classified tape displays on the University of Alaska CDU-200 and by comparison with aerial photography. It has been concluded that the archaeological signatures now in use are as good as can be developed. Plans are to print out signatures for the entire test area and locate on topographic maps the likely locations of archaeological sites within the test area.

Biological synthesis of nanoparticles in biofilms.

PubMed

Tanzil, Abid H; Sultana, Sujala T; Saunders, Steven R; Shi, Liang; Marsili, Enrico; Beyenal, Haluk

2016-12-01

The biological synthesis of nanoparticles (NPs) by bacteria and biofilms via extracellular redox reactions has received attention because of the minimization of harmful chemicals, low cost, and ease of culturing and downstream processing. Bioreduction mechanisms vary across bacteria and growth conditions, which leads to various sizes and shapes of biosynthesized NPs. NP synthesis in biofilms offers additional advantages, such as higher biomass concentrations and larger surface areas, which can lead to more efficient and scalable biosynthesis. Although biofilms have been used to produce NPs, the mechanistic details of NP formation are not well understood. In this review, we identify three critical areas of research and development needed to advance our understanding of NP production by biofilms: 1) synthesis, 2) mechanism and 3) stabilization. Advancement in these areas could result in the biosynthesis of NPs that are suitable for practical applications, especially in drug delivery and biocatalysis. Specifically, the current status of methods and mechanisms of nanoparticle synthesis and surface stabilization using planktonic bacteria and biofilms is discussed. We conclude that the use of biofilms to synthesize and stabilize NPs is underappreciated and could provide a new direction in biofilm-based NP production. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of geometrical characteristics of dental endodontic micro-instruments utilizing X-ray micro computed tomography

PubMed Central

Al JABBARI, Youssef S.; TSAKIRIDIS, Peter; ELIADES, George; AL-HADLAQ, Solaiman M.; ZINELIS, Spiros

2012-01-01

Objective The aim of this study was to quantify the surface area, volume and specific surface area of endodontic files employing quantitative X-ray micro computed tomography (mXCT). Material and Methods Three sets (six files each) of the Flex-Master Ni-Ti system (Nº 20, 25 and 30, taper .04) were utilized in this study. The files were scanned by mXCT. The surface area and volume of all files were determined from the cutting tip up to 16 mm. The data from the surface area, volume and specific area were statistically evaluated using the one-way ANOVA and SNK multiple comparison tests at α=0.05, employing the file size as a discriminating variable. The correlation between the surface area and volume with nominal ISO sizes were tested employing linear regression analysis. Results The surface area and volume of Nº 30 files showed the highest value followed by Nº 25 and Nº 20 and the differences were statistically significant. The Nº 20 files showed a significantly higher specific surface area compared to Nº 25 and Nº 30. The increase in surface and volume towards higher file sizes follows a linear relationship with the nominal ISO sizes (r2=0.930 for surface area and r2=0.974 for volume respectively). Results indicated that the surface area and volume demonstrated an almost linear increase while the specific surface area exhibited an abrupt decrease towards higher sizes. Conclusions This study demonstrates that mXCT can be effectively applied to discriminate very small differences in the geometrical features of endodontic micro-instruments, while providing quantitative information for their geometrical properties. PMID:23329248

A Mathematical Method to Calculate Tumor Contact Surface Area: An Effective Parameter to Predict Renal Function after Partial Nephrectomy.

PubMed

Hsieh, Po-Fan; Wang, Yu-De; Huang, Chi-Ping; Wu, Hsi-Chin; Yang, Che-Rei; Chen, Guang-Heng; Chang, Chao-Hsiang

2016-07-01

We proposed a mathematical formula to calculate contact surface area between a tumor and renal parenchyma. We examined the applicability of using contact surface area to predict renal function after partial nephrectomy. We performed this retrospective study in patients who underwent partial nephrectomy between January 2012 and December 2014. Based on abdominopelvic computerized tomography or magnetic resonance imaging, we calculated the contact surface area using the formula (2*π*radius*depth) developed by integral calculus. We then evaluated the correlation between contact surface area and perioperative parameters, and compared contact surface area and R.E.N.A.L. (Radius/Exophytic/endophytic/Nearness to collecting system/Anterior/Location) score in predicting a reduction in renal function. Overall 35, 26 and 45 patients underwent partial nephrectomy with open, laparoscopic and robotic approaches, respectively. Mean ± SD contact surface area was 30.7±26.1 cm(2) and median (IQR) R.E.N.A.L. score was 7 (2.25). Spearman correlation analysis showed that contact surface area was significantly associated with estimated blood loss (p=0.04), operative time (p=0.04) and percent change in estimated glomerular filtration rate (p <0.001). On multivariate analysis contact surface area and R.E.N.A.L. score independently affected percent change in estimated glomerular filtration rate (p <0.001 and p=0.03, respectively). On ROC curve analysis contact surface area was a better independent predictor of a greater than 10% change in estimated glomerular filtration rate compared to R.E.N.A.L. score (AUC 0.86 vs 0.69). Using this simple mathematical method, contact surface area was associated with surgical outcomes. Compared to R.E.N.A.L. score, contact surface area was a better predictor of functional change after partial nephrectomy. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Ground-water-level monitoring, basin boundaries, and potentiometric surfaces of the aquifer system at Edwards Air Force Base, California, 1992

USGS Publications Warehouse

Rewis, D.L.

1995-01-01

A ground-water-level monitoring program was implemented at Edwards Air Force Base, California, from January through December 1992 to monitor spatial and temporal changes in poten-tiometric surfaces that largely are affected by ground-water pumping. Potentiometric-surface maps are needed to determine the correlation between declining ground- water levels and the distribution of land subsidence. The monitoring program focused on areas of the base where pumping has occurred, especially near Rogers Lake, and involved three phases of data collection: (1) well canvassing and selection, (2) geodetic surveys, and (3) monthly ground-water-level measurements. Construction and historical water- level data were compiled for 118 wells and pi-ezometers on or near the base, and monthly ground-water-level measurements were made in 82 wells and piezometers on the base. The compiled water-level data were used in conjunction with previously collected geologic data to identify three types of no-flow boundaries in the aquifer system: structural boundaries, a principal-aquifer boundary, and ground-water divides. Heads were computed from ground-water-level measurements and land-surface altitudes and then were used to map seasonal potentiometric surfaces for the principal and deep aquifers underlying the base. Pumping has created a regional depression in the potentiometric surface of the deep aquifer in the South Track, South Base, and Branch Park well-field area. A 15-foot decline in the potentiometric surface from April to September 1992 and 20- to 30-foot drawdowns in the three production wells in the South Track well field caused locally unconfined conditions in the deep aquifer.

Improvement of oxygen-containing functional groups on olive stones activated carbon by ozone and nitric acid for heavy metals removal from aqueous phase.

PubMed

Bohli, Thouraya; Ouederni, Abdelmottaleb

2016-08-01

Recently, modification of surface structure of activated carbons in order to improve their adsorption performance toward especial pollutants has gained great interest. Oxygen-containing functional groups have been devoted as the main responsible for heavy metal binding on the activated carbon surface; their introduction or enhancement needs specific modification and impregnation methods. In the present work, olive stones activated carbon (COSAC) undergoes surface modifications in gaseous phase using ozone (O3) and in liquid phase using nitric acid (HNO3). The activated carbon samples were characterized using N2 adsorption-desorption isotherm, SEM, pHpzc, FTIR, and Boehm titration. The activated carbon parent (COSAC) has a high surface area of 1194 m(2)/g and shows a predominantly microporous structure. Oxidation treatments with nitric acid and ozone show a decrease in both specific surface area and micropore volumes, whereas these acidic treatments have led to a fixation of high amount of surface oxygen functional groups, thus making the carbon surface more hydrophilic. Activated carbon samples were used as an adsorbent matrix for the removal of Co(II), Ni(II), and Cu(II) heavy metal ions from aqueous solutions. Adsorption isotherms were obtained at 30 °C, and the data are well fitted to the Redlich-Peterson and Langmuir equation. Results show that oxidized COSACs, especially COSAC(HNO3), are capable to remove more Co(II), Cu(II), and Ni(II) from aqueous solution. Nitric acid-oxidized olive stones activated carbon was tested in its ability to remove metal ions from binary systems and results show an important maximum adsorbed amount as compared to single systems.

Surface Curvature Relation to Protein Adsorption for Carbon-based Nanomaterials

NASA Astrophysics Data System (ADS)

Gu, Zonglin; Yang, Zaixing; Chong, Yu; Ge, Cuicui; Weber, Jeffrey K.; Bell, David R.; Zhou, Ruhong

2015-06-01

The adsorption of proteins onto carbon-based nanomaterials (CBNs) is dictated by hydrophobic and π-π interactions between aliphatic and aromatic residues and the conjugated CBN surface. Accordingly, protein adsorption is highly sensitive to topological constraints imposed by CBN surface structure; in particular, adsorption capacity is thought to increase as the incident surface curvature decreases. In this work, we couple Molecular Dynamics (MD) simulations with fluorescence spectroscopy experiments to characterize this curvature dependence in detail for the model protein bovine serum albumin (BSA). By studying BSA adsorption onto carbon nanotubes of increasing radius (featuring descending local curvatures) and a flat graphene sheet, we confirm that adsorption capacity is indeed enhanced on flatter surfaces. Naïve fluorescence experiments featuring multi-walled carbon nanotubes (MWCNTs), however, conform to an opposing trend. To reconcile these observations, we conduct additional MD simulations with MWCNTs that match those prepared in experiments; such simulations indicate that increased mass to surface area ratios in multi-walled systems explain the observed discrepancies. In reduction, our work substantiates the inverse relationship between protein adsorption capacity and surface curvature and further demonstrates the need for subtle consideration in experimental and simulation design.

[Adequate prescription and application of topicals : How to calculate the right volume for the prescription of ointment needed?

PubMed

Homayoon, D; Dahlhoff, P; Augustin, M

2017-12-15

Uncertainty regarding the suitable amount of prescribed ointment and its application by patients may cause insufficient or uneconomic health care provision. To address this issue, standardized methods and experts' knowledge on the suitable amount and coherent patient's elucidation for application of topicals are needed. Presented are current data in routine care and scientific evidence on the prescribed amount of topical agents as well as its application by patients in dermatological care. A literature review was conducted via PubMed using the keywords as individual and pooled search terms: "local therapy", "topical treatment", "prescription", "amount of ointment needed", "involved area", "BSA", "finger-tip-unit", "Rule of Hand", "calculated dosage" and "rule of nines". We included original studies by manually screening title and abstract according to the relevance of the topic. The search strategy identified 19 clinical trials. The fingertip unit (FTU) is the most frequently used measurement for accurate application of external agents. Appropriate prescribed amount is calculated by required topical agent per involved surface area. There is still a need for clarification to which extent the optimized amount of ointment is prescribed and advice for its application in routine care is given. The FTU combined with the "Rule of Hand" is an adequate measurement for patient's guidance on self-application.

Ultrasonic Measurements of Bore Temperature in Large Caliber Guns

NASA Astrophysics Data System (ADS)

Yuhas, Donald E.; Mutton, Mark J.; Remiasz, Jack R.; Vorres, Carol L.

2009-03-01

The Navy has a need to measure temperatures at critical areas on large caliber gun inner bore surfaces to insure appropriate action is taken in case of a misfire. Inappropriate actions could result in the loss of life and the disabling of a naval warship. In this report we describe the development of an ultrasonic-based sensor capable of non-intrusively measuring internal bore temperature. The results obtained during live fire field trials will be presented.

Report on results of current and future metal casting

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

Unal, Cetin; Carlson, Neil N.

2015-09-28

New modeling capabilities needed to simulate the casting of metallic fuels are added to Truchas code. In this report we summarize improvements we made in FY2015 in three areas; (1) Analysis of new casting experiments conducted with BCS and EFL designs, (2) the simulation of INL’s U-Zr casting experiments with Flow3D computer program, (3) the implementation of surface tension model into Truchas for unstructured mesh required to run U-Zr casting.

Stainless hooks to bond lower lingual retainer.

PubMed

Durgekar, Sujala G; Nagaraj, K

2011-01-01

We introduced a simple and economical technique for precise placement of lower lingual retainers. Two stainless steel hooks made of 0.6mm wire are placed interdentally in the embrasure area between canine and lateral incisor bilaterally to lock the retainer wire in the correct position. Etch, rinse and dry the enamel surfaces with the retainer passively in place, then bond the retainer with light-cured adhesive. Hooks are simple to fabricate and eliminate the need for a transfer tray.

Development of a New Arterial-Line Filter Design Using Computational Fluid Dynamics Analysis

PubMed Central

Herbst, Daniel P.; Najm, Hani K.

2012-01-01

Abstract: Arterial-line filters used during extracorporeal circulation continue to rely on the physical properties of a wetted micropore and reductions in blood flow velocity to affect air separation from the circulating blood volume. Although problems associated with air embolism during cardiac surgery persist, a number of investigators have concluded that further improvements in filtration are needed to enhance air removal during cardiopulmonary bypass procedures. This article reviews theoretical principles of micropore filter technology and outlines the development of a new arterial-line filter concept using computational fluid dynamics analysis. Manufacturer-supplied data of a micropore screen and experimental results taken from an ex vivo test circuit were used to define the inputs needed for numerical modeling of a new filter design. Flow patterns, pressure distributions, and velocity profiles predicted with computational fluid dynamics softwarewere used to inform decisions on model refinements and how to achieve initial design goals of ≤225 mL prime volume and ≤500 cm2 of screen surface area. Predictions for optimal model geometry included a screen angle of 56° from the horizontal plane with a total surface area of 293.9 cm2 and a priming volume of 192.4 mL. This article describes in brief the developmental process used to advance a new filter design and supports the value of numerical modeling in this undertaking. PMID:23198394

Development of a new arterial-line filter design using computational fluid dynamics analysis.

PubMed

Herbst, Daniel P; Najm, Hani K

2012-09-01

Arterial-line filters used during extracorporeal circulation continue to rely on the physical properties of a wetted micropore and reductions in blood flow velocity to affect air separation from the circulating blood volume. Although problems associated with air embolism during cardiac surgery persist, a number of investigators have concluded that further improvements in filtration are needed to enhance air removal during cardiopulmonary bypass procedures. This article reviews theoretical principles of micropore filter technology and outlines the development of a new arterial-line filter concept using computational fluid dynamics analysis. Manufacturer-supplied data of a micropore screen and experimental results taken from an ex vivo test circuit were used to define the inputs needed for numerical modeling of a new filter design. Flow patterns, pressure distributions, and velocity profiles predicted with computational fluid dynamics software were used to inform decisions on model refinements and how to achieve initial design goals of < or = 225 mL prime volume and < or = 500 cm2 of screen surface area. Predictions for optimal model geometry included a screen angle of 56 degrees from the horizontal plane with a total surface area of 293.9 cm2 and a priming volume of 192.4 mL. This article describes in brief the developmental process used to advance a new filter design and supports the value of numerical modeling in this undertaking.

Do we need a voxel-based approach for LiDAR data in geomorphology?

NASA Astrophysics Data System (ADS)

Székely, Balázs; Dorninger, Peter; Faber, Robert; Nothegger, Clemens

2010-05-01

Generations of geomorphologists have developed a multi-faceted approach to model the Earth's (and planetary) surface and the corresponding processes. This set of models is based on data, more specifically on conspicuously increasing amount of data. Obviously, all geomorphologists wish themselves more accurate and increasingly high resolution data on, or related to the Earth surface. This evolution also means that the studied boundary is not anymore a single surface; instead it is considered mostly a 2.5D object, sometimes a real 3D object. LiDAR technology can cope with this challenge: the data accuracy and resolution requirements can be fulfilled by applying this method. Although it is yet somewhat still expensive, more and more areas will be scanned, and in some regions the topographic point clouds are already multitemporal (causing of course other types of processing and evaluation problems). It is rather obvious that for certain, geomorphologically very interesting areas very dense and severalfold multitemporal LiDAR data will be available in the near future. These data sets will have various differences concerning the data density, accuracy, data acquisition technique (conventional or full-waveform), and perhaps most importantly, concerning the actual state of the surface. Similar to the satellite imagery integration problems, soon we all have to face with the LiDAR data integration problem. What type of surface or surfaces can be derived from this multitude of data sources with acceptable ambiguity? What conclusions can be drawn from these data that were originally acquired for various other purposes using various acquisition concepts? Will it be advantageous for geomorphic use to have a coverage of the surface with 100-200 points/m² density? Clearly, these data are, if they are once collected, still too expensive not to be integrated for further analyses. Consequently, we need a data reduction concept that effectively decreases the computer capacity needed to store, process and visualize the results. To reduce the amount of originally collected data for further applications, in general, continuous model surfaces are derived from the point clouds using interpolation approaches. Commonly, grid-based or triangulation models are used for that purpose. Typical models are Digital Surface Models (DSM) representing the whole topography including all natural (e.g. vegetation) and artificial (e.g. buildings) objects and Digital Terrain Models (DTM) representing the topography only. In the visual computing industry the voxel-based approach is quite common for various purposes. Although this technology is quite straightforward concerning the data reduction, it is hardly applied in the geomorphic context. An argument can be against its application that mostly we are interested in a surface, not a volume. Of course in the strict sense it is true, however, if we consider the technology itself how the data, especially the ground data are derived, it turns out that actually it is a volume with a certain accuracy that we are sampling of. The position of this "relatively thin" volume also varies, especially in mountainous areas. Here, depending on the slope angles, the accuracy also varies, especially for the integrated data set consisting of a multitude of sources, e.g. mixing conventional (first echo/last echo) and full-waveform data. These point clouds also contain attributes that otherwise could be very valuable, but during the integration, their meaning may be lost, or it cannot be integrated to the data set. A large scale application of such approaches is mainly prevented by the problems introduced by the high amount of data, making on-the-fly processing a challenging task. To overcome these restrictions and to enable taking advantage of the new possibilities provided by the waveform analysis, we propose a voxel-based data representation approach. The multichannel/multilayer design with an a priori unlimited number of layers enables storing an unlimited number of additional parameter per point. We expect that such a voxel structure enables to represent and analyze huge datasets of large areas (e.g., connected regions which are geologically relevant to be analyzed at once) in applicable processing times in order to bridge the gap between the original point cloud and the user and interpretation level. The challenging task to be solved will be to reduce the amount of data significantly by means of the proposed structure while preserving the content of the original data.

Prognostication of valvular aortic stenosis using tissue Doppler echocardiography: underappreciated importance of late diastolic mitral annular velocity.

PubMed

Poh, Kian-Keong; Chan, Mark Yan-Yee; Yang, Hong; Yong, Quek-Wei; Chan, Yiong-Huak; Ling, Lieng H

2008-05-01

Intact left atrial booster pump function helps maintain cardiac compensation in patients with aortic valve stenosis (AS). Because late diastolic mitral annular (A') velocity reflects left atrial systolic function, we hypothesized that A' velocity correlates with plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) level and clinical outcome in AS. We prospectively enrolled 53 consecutive patients (median age 74 years) with variable degrees of AS, in sinus rhythm, and left ventricular ejection fraction greater than 50%. Indices of valvular stenosis, left ventricular diastolic dysfunction, and mitral annular motion were correlated with plasma NT-proBNP and a composite clinical end point comprising cardiac death and symptom-driven aortic valve replacement. Tissue Doppler echocardiographic parameters, including early diastolic (E') velocity and A' velocity and ratio of early diastolic transmitral (E) to E' velocity (E/E') at the annular septum correlated better with NT-proBNP levels than body surface area-indexed aortic valve area. Eighteen patients had the composite end point, which was univariately predicted by body surface area-indexed aortic valve area, NT-proBNP, and all tissue Doppler echocardiographic indices. This outcome was most strongly predicted by the combination of septal A' velocity and E/E' ratio in bivariate Cox modeling. Septal annular A' velocity less than 9.6 cm/s was associated with significantly reduced event-free survival (Kaplan Meier log rank = 27.3, P < .0001) and predicted the end point with a sensitivity, specificity, and accuracy of 94%, 80%, and 85%, respectively. In patients with AS and normal ejection fraction, annular tissue Doppler echocardiographic indices may better reflect the physiologic consequences of afterload burden on the left ventricle than body surface area-indexed aortic valve area. Lower A' velocity is a predictor of cardiac death and need for valve surgery, suggesting an important role for compensatory left atrial booster pump function.

Estimation of grazing-induced erosion through remote-sensing technologies in the Autonomous Province of Trento, Northern Italy

NASA Astrophysics Data System (ADS)

Torresani, Loris; Prosdocimi, Massimo; Masin, Roberta; Penasa, Mauro; Tarolli, Paolo

2017-04-01

Grassland and pasturelands cover a vast portion of the Earth surface and are vital for biodiversity richness, environmental protection and feed resources for livestock. Overgrazing is considered one of the major causes of soil degradation worldwide, mainly in pasturelands grazed by domestic animals. Therefore, an in-depth investigation to better quantify the effects of overgrazing in terms of soil loss is needed. At this regard, this work aims to estimate the volume of eroded materials caused by mismanagement of grazing areas in the whole Autonomous Province of Trento (Northern Italy). To achieve this goal, the first step dealt with the analysis of the entire provincial area by means of freely available aerial images, which allowed the identification and accurate mapping of every eroded area caused by grazing animals. The terrestrial digital photogrammetric technique, namely Structure from Motion (SfM), was then applied to obtain high-resolution Digital Surface Models (DSMs) of two representative eroded areas. By having the pre-event surface conditions, DSMs of difference, namely DoDs, was computed to estimate the erosion volume and the average depth of erosion for both areas. The average depths obtained from the DoDs were compared and validated by measures taken in the field. A large amount of depth measures from different sites were then collected to obtain a reference value for the whole province. This value was used as reference depth for calculating the eroded volume in the whole province. In the final stage, the Connectivity Index (CI) was adopted to analyse the existing connection between the eroded areas and the channel network. This work highlighted that SfM can be a solid low-cost technique for the low-cost and fast quantification of eroded soil due to grazing. It can also be used as a strategic instrument for improving the grazing management system at large scales, with the goal of reducing the risk of pastureland degradation.

Wind-tunnel Modelling of Dispersion from a Scalar Area Source in Urban-Like Roughness

NASA Astrophysics Data System (ADS)

Pascheke, Frauke; Barlow, Janet F.; Robins, Alan

2008-01-01

A wind-tunnel study was conducted to investigate ventilation of scalars from urban-like geometries at neighbourhood scale by exploring two different geometries a uniform height roughness and a non-uniform height roughness, both with an equal plan and frontal density of λ p = λ f = 25%. In both configurations a sub-unit of the idealized urban surface was coated with a thin layer of naphthalene to represent area sources. The naphthalene sublimation method was used to measure directly total area-averaged transport of scalars out of the complex geometries. At the same time, naphthalene vapour concentrations controlled by the turbulent fluxes were detected using a fast Flame Ionisation Detection (FID) technique. This paper describes the novel use of a naphthalene coated surface as an area source in dispersion studies. Particular emphasis was also given to testing whether the concentration measurements were independent of Reynolds number. For low wind speeds, transfer from the naphthalene surface is determined by a combination of forced and natural convection. Compared with a propane point source release, a 25% higher free stream velocity was needed for the naphthalene area source to yield Reynolds-number-independent concentration fields. Ventilation transfer coefficients w T / U derived from the naphthalene sublimation method showed that, whilst there was enhanced vertical momentum exchange due to obstacle height variability, advection was reduced and dispersion from the source area was not enhanced. Thus, the height variability of a canopy is an important parameter when generalising urban dispersion. Fine resolution concentration measurements in the canopy showed the effect of height variability on dispersion at street scale. Rapid vertical transport in the wake of individual high-rise obstacles was found to generate elevated point-like sources. A Gaussian plume model was used to analyse differences in the downstream plumes. Intensified lateral and vertical plume spread and plume dilution with height was found for the non-uniform height roughness.

Recent High Heat Flux Tests on W-Rod-Armored Mockups

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

NYGREN,RICHARD E.; YOUCHISON,DENNIS L.; MCDONALD,JIMMIE M.

2000-07-18

In the authors initial high heat flux tests on small mockups armored with W rods, done in the small electron beam facility (EBTS) at Sandia National Laboratories, the mockups exhibited excellent thermal performance. However, to reach high heat fluxes, they reduced the heated area to only a portion ({approximately}25%) of the sample. They have now begun tests in their larger electron beam facility, EB 1200, where the available power (1.2 MW) is more than enough to heat the entire surface area of the small mockups. The initial results indicate that, at a given power, the surface temperatures of rods inmore » the EB 1200 tests is somewhat higher than was observed in the EBTS tests. Also, it appears that one mockup (PW-10) has higher surface temperatures than other mockups with similar height (10mm) W rods, and that the previously reported values of absorbed heat flux on this mockup were too high. In the tests in EB 1200 of a second mockup, PW-4, absorbed heat fluxes of {approximately}22MW/m{sup 2} were reached but the corresponding surface temperatures were somewhat higher than in EBTS. A further conclusion is that the simple 1-D model initially used in evaluating some of the results from the EBTS testing was not adequate, and 3-D thermal modeling will be needed to interpret the results.« less

Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography.

PubMed

Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

2015-01-01

A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography ([Formula: see text]) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In [Formula: see text], the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer-Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to [Formula: see text] in SS-OCT. A correlation between [Formula: see text] and SS-OCT was found regarding lesion depth ([Formula: see text], [Formula: see text]) and also surface layer thickness ([Formula: see text], [Formula: see text]). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution [Formula: see text] without the use of x-ray.

Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography

PubMed Central

Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

2015-01-01

Abstract. A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography (μCT) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In μCT, the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer–Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to 606  μm in SS-OCT. A correlation between μCT and SS-OCT was found regarding lesion depth (R=0.81, p<0.001) and also surface layer thickness (R=0.76, p<0.005). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution μCT without the use of x-ray. PMID:26158079

Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area

PubMed Central

Mukherjee, Nabanita; Dowd, Scot E.; Wise, Andy; Kedia, Sapna; Vohra, Varun; Banerjee, Pratik

2014-01-01

Public fitness centers and exercise facilities have been implicated as possible sources for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial community residing on the surfaces in these indoor environments is still unknown. In this study, we investigated the overall bacterial ecology of selected fitness centers in a metropolitan area (Memphis, TN, USA) utilizing culture-independent pyrosequencing of the 16S rRNA genes. Samples were collected from the skin-contact surfaces (e.g., exercise instruments, floor mats, handrails, etc.) within fitness centers. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Proteobacter and Actinobacteria, with a total of 17 bacterial families and 25 bacterial genera. Most of these bacterial genera are of human and environmental origin (including, air, dust, soil, and water). Additionally, we found the presence of some pathogenic or potential pathogenic bacterial genera including Salmonella, Staphylococcus, Klebsiella, and Micrococcus. Staphylococcus was found to be the most prevalent genus. Presence of viable forms of these pathogens elevates risk of exposure of any susceptible individuals. Several factors (including personal hygiene, surface cleaning and disinfection schedules of the facilities) may be the reasons for the rich bacterial diversity found in this study. The current finding underscores the need to increase public awareness on the importance of personal hygiene and sanitation for public gym users. PMID:25479039

Influence of specific surface area on coal dust explosibility using the 20-L chamber.

PubMed

Zlochower, Isaac A; Sapko, Michael J; Perera, Inoka E; Brown, Connor B; Harris, Marcia L; Rayyan, Naseem S

2018-07-01

The relationship between the explosion inerting effectiveness of rock dusts on coal dusts, as a function of the specific surface area (cm 2 /g) of each component is examined through the use of 20-L explosion chamber testing. More specifically, a linear relationship is demonstrated for the rock dust to coal dust (or incombustible to combustible) content of such inerted mixtures with the specific surface area of the coal and the inverse of that area of the rock dust. Hence, the inerting effectiveness, defined as above, is more generally linearly dependent on the ratio of the two surface areas. The focus on specific surface areas, particularly of the rock dust, provide supporting data for minimum surface area requirements in addition to the 70% less than 200 mesh requirement specified in 30 CFR 75.2.

Nanocrystal cellulose as drug excipient in transdermal patch for wound healing: an overview

NASA Astrophysics Data System (ADS)

Zuki, S. A. Mohd; Rahman, N. Abd; Abu Bakar, N. F.

2018-03-01

Wound must be carefully treated to avoid serious infection that needs costly treatment. Method to enhance the recovery of the wound is crucial to have effective wound treatment. One of the technologies in wound treatment is transdermal patch that has the benefits of being non-invasive, easy to handle and permits constant drug dosage. In order to obtain a good controlled drug release, drug excipient needs to be investigated. Recently, natural Nanocrystal Cellulose (NCC) which can be synthesized from animal, algae, microorganism or plant has been actively used in drug delivery system as excipient. The application of NCC is advantageous due to its large surface area, biodegradable, non-toxic and abundance source.

Optical Manufacturing and Testing Requirements Identified by the NASA Science Instruments, Observatories and Sensor Systems Technology Assessment

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Barney, Rich; Bauman, Jill; Feinberg, Lee; Mcleese, Dan; Singh, Upendra

2011-01-01

In August 2010, the NASA Office of Chief Technologist (OCT) commissioned an assessment of 15 different technology areas of importance to the future of NASA. Technology assessment #8 (TA8) was Science Instruments, Observatories and Sensor Systems (SIOSS). SIOSS assess the needs for optical technology ranging from detectors to lasers, x-ray mirrors to microwave antenna, in-situ spectrographs for on-surface planetary sample characterization to large space telescopes. The needs assessment looked across the entirety of NASA and not just the Science Mission Directorate. This paper reviews the optical manufacturing and testing technologies identified by SIOSS which require development in order to enable future NASA high priority missions.

Tribology theory versus experiment

NASA Technical Reports Server (NTRS)

Ferrante, John

1987-01-01

Tribology, the study of friction and wear of materials, has achieved a new interest because of the need for energy conservation. Fundamental understanding of this field is very complex and requires a knowledge of solid-state physics, material science, chemistry, and mechanical engineering. This paper is meant to be didactic in nature and outlines some of the considerations needed for a tribology research program. The approach is first to present a simple model, a field emission tip in contact with a flat surface, in order to elucidate important considerations, such as contact area, mechanical deformations, and interfacial bonding. Then examples from illustrative experiments are presented. Finally, the current status of physical theories concerning interfacial bonding are presented.

Estimating Number of People Using Calibrated Monocular Camera Based on Geometrical Analysis of Surface Area

NASA Astrophysics Data System (ADS)

Arai, Hiroyuki; Miyagawa, Isao; Koike, Hideki; Haseyama, Miki

We propose a novel technique for estimating the number of people in a video sequence; it has the advantages of being stable even in crowded situations and needing no ground-truth data. By analyzing the geometrical relationships between image pixels and their intersection volumes in the real world quantitatively, a foreground image directly indicates the number of people. Because foreground detection is possible even in crowded situations, the proposed method can be applied in such situations. Moreover, it can estimate the number of people in an a priori manner, so it needs no ground-truth data unlike existing feature-based estimation techniques. Experiments show the validity of the proposed method.

A systematic methodology for selecting decontamination strategies following a biocontamination event.

PubMed

Krauter, Paula; Edwards, Donna; Yang, Lynn; Tucker, Mark

2011-09-01

Decontamination and recovery of a facility or outdoor area after a wide-area biological incident involving a highly persistent agent (eg, Bacillus anthracis spores) is a complex process that requires extensive information and significant resources, which are likely to be limited, particularly if multiple facilities or areas are affected. This article proposes a systematic methodology for evaluating information to select the decontamination or alternative treatments that optimize use of resources if decontamination is required for the facility or area. The methodology covers a wide range of approaches, including volumetric and surface decontamination, monitored natural attenuation, and seal and abandon strategies. A proposed trade-off analysis can help decision makers understand the relative appropriateness, efficacy, and labor, skill, and cost requirements of the various decontamination methods for the particular facility or area needing treatment--whether alone or as part of a larger decontamination effort. Because the state of decontamination knowledge and technology continues to evolve rapidly, the methodology presented here is designed to accommodate new strategies and materials and changing information.

Maps summarizing geohydrologic information in an area of salt-water disposal, eastern Altamount-Bluebell Petroleum Field, Uinta Basin, Utah

USGS Publications Warehouse

Freethey, Geoffrey W.

1994-01-01

In the Altamont-Bluebell Petroleum Field within the Uinta Basin of Utah, saline oil-production water is being injected into the Duchesne River Formation. On the basis of geohydrologic information, a qualitative assessment of the possible effects of this injection indicates that fresh groundwater in certain areas of the Duchesne River formation may be more susceptible than water in other areas to becoming mixed with injected oil-production water. The reason for this possible mixing is because these areas containing the susceptible groundwater lack a thick shale layer above the disposal zone, as indicated in geophysical logs. In other areas, naturally occurring moderately saline water exists at shallow depths and may be withdrawn from water wells completed more than 200 ft below land surface. Additional geohydrologic information will need to be collected to allow investigators to make a quantitative determination of the rate of horizontal and vertical migration of injected oil-production water within and above the disposal zone.

Are Water-lean Solvent Systems Viable for Post-Combustion CO 2 Capture?

DOE PAGES

Heldebrant, David J.; Koech, Phillip K.; Rousseau, Roger; ...

2017-08-18

Here, we present here an overview of water-lean solvents that compares their projected costs and performance to aqueous amine systems, emphasizing critical areas of study needed to evaluate their performance against their water-based brethren. The work presented her focuses on bridging these knowledge gaps. Because the majority of water-lean solvents are still at the lab scale, substantial studies are still needed to model their performance at scale. This presents a significant challenge as eachformulation has different physical and thermodynamic properties and behavior, and quantifying how these different properties manifest themselves in conventional absorber-stripper configurations, or identifying new configurations that aremore » specific for a solvent’s signature behavior. We identify critical areas of study that are needed, and our efforts (e.g. custom infrastructure, molecular models) to predict, measure, and model these behaviors. Such findings are critical for determining the rheology required for heat exchanger design; absorber designs and packing to accommodate solvents with gradient changes (e.g. viscosity, contact angle, surface tension), and stripper configurations without direct steam utilization or water reflux. Another critical area of research need is to understand the molecular structure of the liquid interface and bulk as a function of CO 2 loading, and to assess whether conventional film theories accurately quantify solvent behavior, or if thermodynamic models adequately quantify activity coefficients of ions in solution. We conclude with an assessment of our efforts to aid in bridging the knowledge gaps in understanding water-lean solvents, and suggestions of what is needed to enable large-scale demonstrations to meet the United States Department of Energy’s year 2030 goal.« less

Are Water-lean Solvent Systems Viable for Post-Combustion CO 2 Capture?

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

Heldebrant, David J.; Koech, Phillip K.; Rousseau, Roger

Here, we present here an overview of water-lean solvents that compares their projected costs and performance to aqueous amine systems, emphasizing critical areas of study needed to evaluate their performance against their water-based brethren. The work presented her focuses on bridging these knowledge gaps. Because the majority of water-lean solvents are still at the lab scale, substantial studies are still needed to model their performance at scale. This presents a significant challenge as eachformulation has different physical and thermodynamic properties and behavior, and quantifying how these different properties manifest themselves in conventional absorber-stripper configurations, or identifying new configurations that aremore » specific for a solvent’s signature behavior. We identify critical areas of study that are needed, and our efforts (e.g. custom infrastructure, molecular models) to predict, measure, and model these behaviors. Such findings are critical for determining the rheology required for heat exchanger design; absorber designs and packing to accommodate solvents with gradient changes (e.g. viscosity, contact angle, surface tension), and stripper configurations without direct steam utilization or water reflux. Another critical area of research need is to understand the molecular structure of the liquid interface and bulk as a function of CO 2 loading, and to assess whether conventional film theories accurately quantify solvent behavior, or if thermodynamic models adequately quantify activity coefficients of ions in solution. We conclude with an assessment of our efforts to aid in bridging the knowledge gaps in understanding water-lean solvents, and suggestions of what is needed to enable large-scale demonstrations to meet the United States Department of Energy’s year 2030 goal.« less

30 CFR 905.764 - Process for designating areas unsuitable for surface coal mining operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... surface coal mining operations. 905.764 Section 905.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE CALIFORNIA § 905.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal...

30 CFR 910.764 - Process for designating areas unsuitable for surface coal mining operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... surface coal mining operations. 910.764 Section 910.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE GEORGIA § 910.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal...

30 CFR 912.764 - Process for designating areas unsuitable for surface coal mining operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... surface coal mining operations. 912.764 Section 912.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE IDAHO § 912.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal...

30 CFR 903.764 - Process for designating areas unsuitable for surface coal mining operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... surface coal mining operations. 903.764 Section 903.764 Mineral Resources OFFICE OF SURFACE MINING... WITHIN EACH STATE ARIZONA § 903.764 Process for designating areas unsuitable for surface coal mining operations. Part 764 of this chapter, State Processes for Designating Areas Unsuitable for Surface Coal...

Activated, coal-based carbon foam

DOEpatents

Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

2004-12-21

An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

Fabrication technology

NASA Astrophysics Data System (ADS)

1988-05-01

Many laboratory programs continue to need optical components of ever-increasing size and accuracy. Unfortunately, optical surfaces produced by the conventional sequence of grinding, lapping, and polishing can become prohibitively expensive. Research in the Fabrication Technology area focuses on methods of fabricating components with heretofore unrealized levels of precision. In FY87, researchers worked to determine the fundamental mechanical limits of material removal, experimented with unique material removal and deposition processes, developed servo systems for controlling the geometric position of ultraprecise machine tools, and advanced the ability to precisely measure contoured workpieces. Continued work in these areas will lead to more cost-effective processes to fabricate even higher quality optical components for advanced lasers and for visible, ultraviolet, and X-ray diagnostic systems.

Mapping agroecosystem zone using remote sensing for food security analysis in Bantul district Daerah Istimewa Yogyakarta

NASA Astrophysics Data System (ADS)

Murti, Sigit Heru

2017-10-01

Food security is one of the most important issue for Indonesia. The huge population number and high population growing rate has made the food security a critical issue. This paper describe the application of remote sensing data to (1) map agroecosystem zones in Bantul District, Special Region of Yogyakarta, Indonesia in 2012 and (2) analyze the food security in the study area based on the resulting agro-ecosystem map. Bantul District is selected as the pilot area because this area is among the highest food crop production area in the Province. ALOS AVNIR-2 image accquired on 15 June 2010 was integrated with Indonesian Surface map (RBI map), soil types map, and slope steepness map. Population statistics data was also used to calculate the food needs. Field survey was conducted to obtain the crop field productivity information on each agro-ecosystem zone and assess the accuracy of the model. This research indicates that (1) Bantul District can be divided into three agroecosystem zones, where each zone has unique topograhic configuration and soil types composition, and (2) Bantul Distict is categorized as food secure area since the rice production in 2012 managed to cover the food needs of the people with the surplus of 33,208.6 tonnes of rice. However, when the analysis was conducted at sub-district level, there are four subdistrict with food insecurity where the food needs surpass the rice production. These sub-district are Kasihan Sub-district (-5,598.4 t), Banguntapan Sub-district (-2,483.4 t), Pajangan Sub-district (-1,039.6 t) and Dlingo Sub-district (-798.7 t).

The use of total lake-surface area as an indicator of climatic change: Examples from the Lahontan basin

USGS Publications Warehouse

Benson, L.V.; Paillet, Frederick L.

1989-01-01

Variation in the size of lakes in the Lahontan basin is topographically constrained. River diversion also has played a major role in regulating lake size in Lahontan subbasins. The proper gage of lake response to change in the hydrologic balance is neither lake depth (level) nor lake volume but instead lake-surface area. Normalization of surface area is necessary when comparing surface areas of lakes in basins having different topographies. To a first approximation, normalization can be accomplished by dividing the paleosurface area of a lake by its mean-historical, reconstructed surface area. ?? 1989.

Reflected GPS Power for the Detection of Surface Roughness Patterns in Coastal Water

NASA Technical Reports Server (NTRS)

Oertel, George, F.; Allen, Thomas R.

2000-01-01

Coastal bays formed by the barrier islands of Delaware, Maryland and Virginia are parts of a coastal region known as a "Coastal Compartment". The coastal compartment between the Chesapeake and Delaware Bays is actually the mosaic of landscapes on the headland of the interfluve that separates these large drainage basins. The coastal compartments form a variety of different-shaped waterways landward of the coastline. Shape differences along the boundaries produce differences in exposure to wind and waves. Different shoreface topographies seaward of the coastline also influence surface roughness by changing wave-refraction patterns. Surface-water roughness (caused by waves) is controlled by a number of parameters, including fetch, shielding, exposure corridors, water-mass boundary conditions, wetland vegetation and water depth in coastal bays. In the coastal ocean, surface roughness patterns are controlled by shoreface shoaling and inlet refraction patterns in the coastal ocean. Knowledge of wave phenomena in the nearshore and backbarrier areas is needed to understand how wave climate influences important ecosystems in estuaries and bays.

Lunar surface exploration using mobile robots

NASA Astrophysics Data System (ADS)

Nishida, Shin-Ichiro; Wakabayashi, Sachiko

2012-06-01

A lunar exploration architecture study is being carried out by space agencies. JAXA is carrying out research and development of a mobile robot (rover) to be deployed on the lunar surface for exploration and outpost construction. The main target areas for outpost construction and lunar exploration are mountainous zones. The moon's surface is covered by regolith. Achieving a steady traversal of such irregular terrain constitutes the major technical problem for rovers. A newly developed lightweight crawler mechanism can effectively traverse such irregular terrain because of its low contact force with the ground. This fact was determined on the basis of the mass and expected payload of the rover. This paper describes a plan for Japanese lunar surface exploration using mobile robots, and presents the results of testing and analysis needed in their development. This paper also gives an overview of the lunar exploration robot to be deployed in the SELENE follow-on mission, and the composition of its mobility, navigation, and control systems.

Past epochs of significantly higher pressure atmospheres on Pluto

NASA Astrophysics Data System (ADS)

Stern, S. A.; Binzel, R. P.; Earle, A. M.; Singer, K. N.; Young, L. A.; Weaver, H. A.; Olkin, C. B.; Ennico, K.; Moore, J. M.; McKinnon, W. B.; Spencer, J. R.; New Horizons Geology; Geophysics; Atmospheres Teams

2017-05-01

Pluto is known to have undergone thousands of cycles of obliquity change and polar precession. These variations have a large and corresponding impact on the total average solar insolation reaching various places on Pluto's surface as a function of time. Such changes could produce dramatic increases in surface pressure and may explain certain features observed by New Horizons on Pluto's surface, including some that indicate the possibility of surface paleo-liquids. This paper is the first to discuss multiple lines of geomorphological evidence consistent with higher pressure epochs in Pluto's geologic past, and it also the first to provide a mechanism for potentially producing the requisite high pressure conditions needed for an environment that could support liquids on Pluto. The presence of such liquids and such conditions, if borne out by future work, would fundamentally affect our view of Pluto's past climate, volatile transport, and geological evolution. This paper motivates future, more detailed climate modeling and geologic interpretation efforts in this area.

Microbial Keratitis: Could Contact Lens Material Affect Disease Pathogenesis?

PubMed Central

Evans, David J.; Fleiszig, Suzanne M. J.

2012-01-01

Microbial keratitis is a sight-threatening complication associated with contact lenses. The introduction of silicone hydrogel lens materials with increased oxygen transmission to the ocular surface has not significantly altered the incidence of microbial keratitis. These data suggest that alternate, or additional, predisposing factors involving lens wear must be addressed to reduce or eliminate these infections. The contact lens can provide a surface for microbial growth in situ, and can also influence ocular surface homeostasis through effects on the tear fluid and corneal epithelium. Thus, it is intuitive that future contact lens materials could make a significant contribution to preventing microbial keratitis. Design of the “right” material to prevent microbial keratitis requires understanding the effects of current materials on bacterial virulence in the cornea, and on ocular surface innate defenses. Current knowledge in each of these areas will be presented, with a discussion of future directions needed to understand the influence of lens material on the pathogenesis of microbial keratitis. PMID:23266587

Cutaneous exposure scenarios for engineered nanoparticles used in semiconductor fabrication: a preliminary investigation of workplace surface contamination

PubMed Central

Shepard, Michele; Brenner, Sara

2014-01-01

Background: Numerous studies are ongoing in the fields of nanotoxicology and exposure science; however, gaps remain in identifying and evaluating potential exposures from skin contact with engineered nanoparticles in occupational settings. Objectives: The aim of this study was to identify potential cutaneous exposure scenarios at a workplace using engineered nanoparticles (alumina, ceria, amorphous silica) and evaluate the presence of these materials on workplace surfaces. Methods: Process review, workplace observations, and preliminary surface sampling were conducted using microvacuum and wipe sample collection methods and transmission electron microscopy with elemental analysis. Results: Exposure scenarios were identified with potential for incidental contact. Nanoparticles of silica or silica and/or alumina agglomerates (or aggregates) were identified in surface samples from work areas where engineered nanoparticles were used or handled. Conclusions: Additional data are needed to evaluate occupational exposures from skin contact with engineered nanoparticles; precautionary measures should be used to minimize potential cutaneous exposures in the workplace. PMID:25000112

Use of modeling to protect, plan, and manage water resources in catchment areas.

PubMed

Constant, Thibaut; Charrière, Séverine; Lioeddine, Abdejalil; Emsellem, Yves

2016-08-01

The degradation of water resources by diffuse pollution, mainly due to nitrate and pesticides, is an important matter for public health. Restoration of the quality of natural water catchments by focusing on their catchment areas is therefore a national priority in France. To consider catchment areas as homogeneous and to expend an equal effort on the entire area inevitably leads to a waste of time and money, and restorative actions may not be as efficient as intended. The variability of the pedological and geological properties of the area is actually an opportunity to invest effort on smaller areas, simply because every action is not equally efficient on every kind of pedological or geological surface. Using this approach, it is possible to invest in a few selected zones that will be efficient in terms of environmental results. The contributive hydraulic areas (CHA) concept is different from that of the catchment area. Because the transport of most of the mobile and persistent pollutants is primarily driven by water circulation, the concept of the CHA is based on the water pathway from the surface of the soil in the catchment area to the well. The method uses a three-dimensional hydrogeological model of surface and groundwater integrated with a geographic information system called Watermodel. The model calculates the contribution (m(3)/h or %) of each point of the soil to the total flow pumped in a well. Application of this model, partially funded by the Seine Normandy Basin Agency, to the catchment of the Dormelles Well in the Cretaceous chalk aquifer in the Orvanne valley, France (catchment area of 23,000 ha at Dormelles, county 77), shows that 95 % of the water pumped at the Dormelles Well comes from only 26 % of the total surface area of the catchment. Consequently, an action plan to protect the water resource will be targeted at the 93 farmers operating in this source area rather than the total number of farmers (250) across the entire 23,000 ha. Another model, developed from Epiclès© software, permits the calculation of the under-root nitrate concentrations for each field based on soil type, climate, and farming practices. When the Watermodel and Epiclès© are coupled, nitrate transfers from the soil to the catchment and the river can be modeled. In this study, the initial pollution due to the actual farming practices was simulated and we were also able to estimate the efficiency of the agronomic action plan by testing several scenarios and calculating the time needed to reach the target nitrate concentration in the well.

Spatiotemporal variation of surface shortwave forcing from fire-induced albedo change in interior Alaska

USGS Publications Warehouse

Huang, Shengli; Dahal, Devendra; Liu, Heping; Jin, Suming; Young, Claudia J.; Liu, Shuang; Liu, Shu-Guang

2015-01-01

The albedo change caused by both fires and subsequent succession is spatially heterogeneous, leading to the need to assess the spatiotemporal variation of surface shortwave forcing (SSF) as a component to quantify the climate impacts of high-latitude fires. We used an image reconstruction approach to compare postfire albedo with the albedo assuming fires had not occurred. Combining the fire-caused albedo change from the 2001-2010 fires in interior Alaska and the monthly surface incoming solar radiation, we examined the spatiotemporal variation of SSF in the early successional stage of around 10 years. Our results showed that while postfire albedo generally increased in fall, winter, and spring, some burned areas could show an albedo decrease during these seasons. In summer, the albedo increased for several years and then declined again. The spring SSF distribution did not show a latitudinal decrease from south to north as previously reported. The results also indicated that although the SSF is usually largely negative in the early successional years, it may not be significant during the first postfire year. The annual 2005-2010 SSF for the 2004 fire scars was -1.30, -4.40, -3.31, -4.00, -3.42, and -2.47 Wm-2. The integrated annual SSF map showed significant spatial variation with a mean of -3.15 Wm-2 and a standard deviation of 3.26 Wm-2, 16% of burned areas having positive SSF. Our results suggest that boreal deciduous fires would be less positive for climate change than boreal evergreen fires. Future research is needed to comprehensively investigate the spatiotemporal radiative and non-radiative forcings to determine the effect of boreal fires on climate.

Molar crown and root size relationship in anthropoid primates.

PubMed

Kupczik, Kornelius; Olejniczak, Anthony J; Skinner, Matthew M; Hublin, Jean-Jacques

2009-01-01

Mandibular corpus form is thought to reflect masticatory function and the size of the dentition, but there is no universal association between crown dimensions and corpus size across anthropoids. Previous research was based on the assumption that crown size is an appropriate proxy for overall tooth size, but this hypothesis remains largely untested. This study assesses the relationship between the volume and surface area of molar crowns and roots by examining two main hypotheses: (1) crown size correlates significantly with root size, and (2) the proportion of root-to-crown surface area is related to dietary proclivity. Permanent M2s (n=58) representing 19 anthropoid species were CT scanned and the volume and surface area of the crown and root were measured. Interspecific correlation and regression analyses reveal significant isometric relationships between crown and root volume and a positive allometric relationship between root and crown surface area (i.e. as crown surface area increases, root surface area becomes disproportionately greater). Intraspecifically, crown and root surface area correlate significantly in some species where such analyses were possible. In general, hard object feeders exhibit relatively larger root surface area per unit crown surface area compared to soft and tough object feeders. The results also show that despite differences in food specialization closely related species have similar root-to-crown surface area proportions, thus indicating a strong phylogenetic influence. Since it is possible that, at least in some species, crown and root size vary independently, future studies should elucidate the relationship between tooth root size and mandible form. Copyright (c) 2009 S. Karger AG, Basel.

Characterization of sediment sources, sediment budget estimations, consequences and implications for populations in the Jatún Mayu watershed (Cochabamba, Bolivia)

NASA Astrophysics Data System (ADS)

Vuignier, Jean-Marie; Penna, Ivanna; Jaboyedoff, Michel; Sudmeier-Rieux, Karen

2015-04-01

Natural and human-induced erosive processes shape landscape by transferring masses from the mountain to downstream areas. They also impact population both located in the source areas of sediments as well as urban areas settle on the depositional area. Mountain areas in Bolivia present high surface dynamics and high rates of rural migrations, causing e.g. a significant increase of population in Cochabamba city in the last 20 years. This work aims to estimate the sediment production on the Jatún Mayu (Pankuruma) watershed in Cochabamba department taking into account the different origins of sediments. The population of this region is predominantly rural and quechua speaking. The region of study consists in a mountain area situated in the Andes with altitudes ranging from 2500 to 4600m. Field work on July 2014 and high resolution satellite image interpretation (2004 & 2009) allowed us to map and measure landslides and gullies. Almost a hundred of landslides are recorded mostly around the river channel in the middle and the lower part of the valley and provide a moving surface estimated at 3,15km2. Most of the gullies are situated in the upper part of the valley where the vegetation is less abundant on low-sloping agricultural lands. Photogrammetric reconstructions using camera and drone were the main method used to characterise some strategic points along the river in order to get dimensions of landslides, gullies, as well as the riverbed roughness, as the final goal was to model the flooding prone area at the mouth of the watershed, were migrants have been settling for the last years. A total of 9 points of interests along the river bed were surveyed and for each of them a square surface equal to 25m2 was analysed. Approximately 250 pictures by area were needed to estimate roughness along the channel. A flood model has been performed, by using the Riverflo-2D software, to produce a susceptibility map of the downstream region.

Age Differences in Prefrontal Surface Area and Thickness in Middle Aged to Older Adults.

PubMed

Dotson, Vonetta M; Szymkowicz, Sarah M; Sozda, Christopher N; Kirton, Joshua W; Green, Mackenzie L; O'Shea, Andrew; McLaren, Molly E; Anton, Stephen D; Manini, Todd M; Woods, Adam J

2015-01-01

Age is associated with reductions in surface area and cortical thickness, particularly in prefrontal regions. There is also evidence of greater thickness in some regions at older ages. Non-linear age effects in some studies suggest that age may continue to impact brain structure in later decades of life, but relatively few studies have examined the impact of age on brain structure within middle-aged to older adults. We investigated age differences in prefrontal surface area and cortical thickness in healthy adults between the ages of 51 and 81 years. Participants received a structural 3-Tesla magnetic resonance imaging scan. Based on a priori hypotheses, primary analyses focused on surface area and cortical thickness in the dorsolateral prefrontal cortex, anterior cingulate cortex, and orbitofrontal cortex. We also performed exploratory vertex-wise analyses of surface area and cortical thickness across the entire cortex. We found that older age was associated with smaller surface area in the dorsolateral prefrontal and orbitofrontal cortices but greater cortical thickness in the dorsolateral prefrontal and anterior cingulate cortices. Vertex-wise analyses revealed smaller surface area in primarily frontal regions at older ages, but no age effects were found for cortical thickness. Results suggest age is associated with reduced surface area but greater cortical thickness in prefrontal regions during later decades of life, and highlight the differential effects age has on regional surface area and cortical thickness.

Surface Area, and Oxidation Effects on Nitridation Kinetics of Silicon Powder Compacts

NASA Technical Reports Server (NTRS)

Bhatt, R. T.; Palczer, A. R.

1998-01-01

Commercially available silicon powders were wet-attrition-milled from 2 to 48 hr to achieve surface areas (SA's) ranging from 1.3 to 70 sq m/g. The surface area effects on the nitridation kinetics of silicon powder compacts were determined at 1250 or 1350 C for 4 hr. In addition, the influence of nitridation environment, and preoxidation on nitridation kinetics of a silicon powder of high surface area (approximately equals 63 sq m/g) was investigated. As the surface area increased, so did the percentage nitridation after 4 hr in N2 at 1250 or 1350 C. Silicon powders of high surface area (greater than 40 sq m/g) can be nitrided to greater than 70% at 1250 C in 4 hr. The nitridation kinetics of the high-surface-area powder compacts were significantly delayed by preoxidation treatment. Conversely, the nitridation environment had no significant influence on the nitridation kinetics of the same powder. Impurities present in the starting powder, and those accumulated during attrition milling, appeared to react with the silica layer on the surface of silicon particles to form a molten silicate layer, which provided a path for rapid diffusion of nitrogen and enhanced the nitridation kinetics of high surface area silicon powder.

In Situ Aerosol Profile Measurements and Comparisons with SAGE 3 Aerosol Extinction and Surface Area Profiles at 68 deg North

NASA Technical Reports Server (NTRS)

2005-01-01

Under funding from this proposal three in situ profile measurements of stratospheric sulfate aerosol and ozone were completed from balloon-borne platforms. The measured quantities are aerosol size resolved number concentration and ozone. The one derived product is aerosol size distribution, from which aerosol moments, such as surface area, volume, and extinction can be calculated for comparison with SAGE III measurements and SAGE III derived products, such as surface area. The analysis of these profiles and comparison with SAGE III extinction measurements and SAGE III derived surface areas are provided in Yongxiao (2005), which comprised the research thesis component of Mr. Jian Yongxiao's M.S. degree in Atmospheric Science at the University of Wyoming. In addition analysis continues on using principal component analysis (PCA) to derive aerosol surface area from the 9 wavelength extinction measurements available from SAGE III. Ths paper will present PCA components to calculate surface area from SAGE III measurements and compare these derived surface areas with those available directly from in situ size distribution measurements, as well as surface areas which would be derived from PCA and Thomason's algorithm applied to the four wavelength SAGE II extinction measurements.

Urban Heat Island ın Ankara

NASA Astrophysics Data System (ADS)

Yılmaz, Erkan

2016-04-01

In this study, the seasonal variation of the surface temperature of Ankara urban area and its enviroment have been analyzed by using Landsat 7 image. The Landsat 7 images of each month from 2007 to 2011 have been used to analyze the annually changes of the surface temperature. The land cover of the research area was defined with supervised classification method on the basis of the satellite image belonging to 2008 July. After determining the surface temperatures from 6-1 bands of satellite images, the monthly mean surface temperatures were calculated for land cover classification for the period between 2007 and 2011. According to the results obtained, the surface temperatures are high in summer and low in winter from the airtemperatures. all satellite images were taken at 10:00 am, it is found that urban areas are cooler than rural areas at 10:00 am. Regarding the land cover classification, the water surfaces are the coolest surfaces during the whole year.The warmest areas are the grasslands and dry farming areas. While the parks are warmer than the urban areas during the winter, during the summer they are cooler than artificial land covers. The urban areas with higher building density are the cooler surfaces after water bodies.

Surface areas of fractally rough particles studied by scattering

NASA Astrophysics Data System (ADS)

Hurd, Alan J.; Schaefer, Dale W.; Smith, Douglas M.; Ross, Steven B.; Le Méhauté, Alain; Spooner, Steven

1989-05-01

The small-angle scattering from fractally rough surfaces has the potential to give information on the surface area at a given resolution. By use of quantitative neutron and x-ray scattering, a direct comparison of surface areas of fractally rough powders was made between scattering and adsorption techniques. This study supports a recently proposed correction to the theory for scattering from fractal surfaces. In addition, the scattering data provide an independent calibration of molecular adsorbate areas.

Ground-water resources of the Bengasi area, Cyrenaica, United Kingdom of Libya

USGS Publications Warehouse

Doyel, William Watson; Maguire, Frank J.

1964-01-01

The Benpsi area of Libya, in the northwestern part of the Province of Cyrenaica (Wilayat Barqah), is semiarid, and available ground-water supplies in the area are relatively small. Potable ground water from known sources is reserved for the present and future needs of the city, and no surface-water supplies are available in the area. This investigation to evaluate known, as well as potential, water supplies in the area was undertaken as part of a larger program of ground-water investigations in Libya under the auspices of the U. S. Operations Mission to Libya and the Government of Libya. A ground-water reservoir underlies the Bengasi area, in which the water occurs in solution channels, cavities, and other openings in Miocene limestone. The reservoir is recharged directly by rainfall on the area and by infiltration from ephemeral streams (wadis) rising in Al Jabal al Akhar to the east. In the Baninah and Al Fuwayhit areas the ground-water reservoir yields water of fair quality and in sufficient quantity for the current (1959) needs. of the Bengasi city supply. The test-drilling program in the area south and southeast of Bengasi indicates that water in sufficient quantity for additional public supply probably can be obtained in some localities from wells. The water, however, is moderately to highly mineralized and would require treatment or demineralization before it could be used for additional public supply. Much of the water could be used directly for irrigation, but careful attention would have to be given to cultivation, drainage, and cropping practices. The hazard of saltwater encroachment also exists if large-scale withdrawals are undertaken in the coastal zones.

Forward to the Future: Estimating River Discharge with McFLI

NASA Astrophysics Data System (ADS)

Gleason, C. J.; Durand, M. T.; Garambois, P. A.

2016-12-01

The global surface water budget is still poorly understood, and improving our understanding of freshwater budgets requires coordination between in situ observations, models, and remote sensing. The upcoming launch of the NASA/CNES Surface Water and Ocean Topography (SWOT) satellite has generated considerable excitement as a new tool enabling hydrologists to tackle some of the most pressing questions facing their discipline. One question in particular which SWOT seems well suited to answer is river discharge (flow rate) estimation in ungauged basins: SWOT's anticipated measurements of river surface height and area have ushered in a new technique in hydrology- what we are here calling Mass conserved Flow Law Inversions, or McFLI. McFLI algorithms leverage classic hydraulic flow expressions (e.g. Manning's Equation, hydraulic geometry) within mass conserved river reaches to construct a simplified but still underconstrained system of equations to be solved for an unknown discharge. Most existing McFLI techniques have been designed to take advantage of SWOT's measurements and Manning's Equation: SWOT will observe changes in cross sectional area and river surface slope over time, so the McFLI need only solve for baseflow area and Manning's roughness coefficient. Recently published preliminary results have indicated that McFLI can be a viable tool in a global hydrologist's toolbox (discharge errors less than 30% as compared to gauges are possible in most cases). Therefore, we here outline the progress to date for McFLI techniques, and highlight three key areas for future development: 1) Maximize the accuracy and robustness of McFLI by incorporating ancillary data from satellites, models, and in situ observations. 2) Develop new McFLI techniques using novel or underutilized flow laws. 3) Systematically test McFLI to define different inversion classes of rivers with well-defined error budgets based on geography and available data for use in gauged and ungauged basins alike.

Deconvolution analysis of 24-h serum cortisol profiles informs the amount and distribution of hydrocortisone replacement therapy.

PubMed

Peters, Catherine J; Hill, Nathan; Dattani, Mehul T; Charmandari, Evangelia; Matthews, David R; Hindmarsh, Peter C

2013-03-01

Hydrocortisone therapy is based on a dosing regimen derived from estimates of cortisol secretion, but little is known of how the dose should be distributed throughout the 24 h. We have used deconvolution analysis of 24-h serum cortisol profiles to determine 24-h cortisol secretion and distribution to inform hydrocortisone dosing schedules in young children and older adults. Twenty four hour serum cortisol profiles from 80 adults (41 men, aged 60-74 years) and 29 children (24 boys, aged 5-9 years) were subject to deconvolution analysis using an 80-min half-life to ascertain total cortisol secretion and distribution throughout the 24-h period. Mean daily cortisol secretion was similar between adults (6.3 mg/m(2) body surface area/day, range 5.1-9.3) and children (8.0 mg/m(2) body surface area/day, range 5.3-12.0). Peak serum cortisol concentration was higher in children compared with adults, whereas nadir serum cortisol concentrations were similar. Timing of the peak serum cortisol concentration was similar (07.05-07.25), whereas that of the nadir concentration occurred later in adults (midnight) compared with children (22.48) (P = 0.003). Children had the highest percentage of cortisol secretion between 06.00 and 12.00 (38.4%), whereas in adults this took place between midnight and 06.00 (45.2%). These observations suggest that the daily hydrocortisone replacement dose should be equivalent on average to 6.3 mg/m(2) body surface area/day in adults and 8.0 mg/m(2) body surface area/day in children. Differences in distribution of the total daily dose between older adults and young children need to be taken into account when using a three or four times per day dosing regimen. © 2012 Blackwell Publishing Ltd.

Estimation of small-scale soil erosion in laboratory experiments with Structure from Motion photogrammetry

NASA Astrophysics Data System (ADS)

Balaguer-Puig, Matilde; Marqués-Mateu, Ángel; Lerma, José Luis; Ibáñez-Asensio, Sara

2017-10-01

The quantitative estimation of changes in terrain surfaces caused by water erosion can be carried out from precise descriptions of surfaces given by means of digital elevation models (DEMs). Some stages of water erosion research efforts are conducted in the laboratory using rainfall simulators and soil boxes with areas less than 1 m2. Under these conditions, erosive processes can lead to very small surface variations and high precision DEMs are needed to account for differences measured in millimetres. In this paper, we used a photogrammetric Structure from Motion (SfM) technique to build DEMs of a 0.5 m2 soil box to monitor several simulated rainfall episodes in the laboratory. The technique of DEM of difference (DoD) was then applied using GIS tools to compute estimates of volumetric changes between each pair of rainfall episodes. The aim was to classify the soil surface into three classes: erosion areas, deposition areas, and unchanged or neutral areas, and quantify the volume of soil that was eroded and deposited. We used a thresholding criterion of changes based on the estimated error of the difference of DEMs, which in turn was obtained from the root mean square error of the individual DEMs. Experimental tests showed that the choice of different threshold values in the DoD can lead to volume differences as large as 60% when compared to the direct volumetric difference. It turns out that the choice of that threshold was a key point in this method. In parallel to photogrammetric work, we collected sediments from each rain episode and obtained a series of corresponding measured sediment yields. The comparison between computed and measured sediment yields was significantly correlated, especially when considering the accumulated value of the five simulations. The computed sediment yield was 13% greater than the measured sediment yield. The procedure presented in this paper proved to be suitable for the determination of sediment yields in rainfall-driven soil erosion experiments conducted in the laboratory.

Robust flood area detection using a L-band synthetic aperture radar: Preliminary application for Florida, the U.S. affected by Hurricane Irma

NASA Astrophysics Data System (ADS)

Nagai, H.; Ohki, M.; Abe, T.

2017-12-01

Urgent crisis response for a hurricane-induced flood needs urgent providing of a flood map covering a broad region. However, there is no standard threshold values for automatic flood identification from pre-and-post images obtained by satellite-based synthetic aperture radars (SARs). This problem could hamper prompt data providing for operational uses. Furthermore, one pre-flood SAR image does not always represent potential water surfaces and river flows especially in tropical flat lands which are greatly influenced by seasonal precipitation cycle. We are, therefore, developing a new method of flood mapping using PALSAR-2, an L-band SAR, which is less affected by temporal surface changes. Specifically, a mean-value image and a standard-deviation image are calculated from a series of pre-flood SAR images. It is combined with a post-flood SAR image to obtain normalized backscatter amplitude difference (NoBADi), with which a difference between a post-flood image and a mean-value image is divided by a standard-deviation image to emphasize anomalous water extents. Flooding areas are then automatically obtained from the NoBADi images as lower-value pixels avoiding potential water surfaces. We applied this method to PALSAR-2 images acquired on Sept. 8, 10, and 12, 2017, covering flooding areas in a central region of Dominican Republic and west Florida, the U.S. affected by Hurricane Irma. The output flooding outlines are validated with flooding areas manually delineated from high-resolution optical satellite images, resulting in higher consistency and less uncertainty than previous methods (i.e., a simple pre-and-post flood difference and pre-and-post coherence changes). The NoBADi method has a great potential to obtain a reliable flood map for future flood hazards, not hampered by cloud cover, seasonal surface changes, and "casual" thresholds in the flood identification process.

A Future Estimation of the Surface Runoff in the Greek Region: A Case Study of one of the Main Catchments Areas (Aravissos - Central Macedonia)

NASA Astrophysics Data System (ADS)

Anagnostopoulou, C.; Tolika, K.; Vafiadis, M.

2010-09-01

According to the IPCC latest report (IPCC, 2007) many semi-arid and arid areas, as the Mediterranean basin, are particularly exposed to the impacts of climate change and may suffer a decrease of water resources in the future. By the middle of the 21st century it is estimated that the annual average river runoff and water availability will decrease over these dry regions at mid-latitudes. So, it is of great importance the study of the future changes in the hydrological cycle, due to the increasing freshwater demands. The main scope of the present study is to estimate the future changes of the surface runoff in the Aravissos area (central Macedonia - Greece) due to the enhanced greenhouse effect until the end of the 21st century. The selection of Aravissos was based to the fact that the water needs of the second largest in population city in Greece (Thessaloniki) are covered mainly by the selected catchments area. Daily precipitation, temperature, relative humidity, wind speed and sunlight duration data derived from updated regional climate models, are used for selected grid points covering the domain of study. The main two climatological parameters (precipitation -temperature) are on a first step evaluated in comparison to re-analysis data (E-Obs -Ensembles project) for the same grid points. On a second step, utilizing several different evapotranspiration methods we calculated the surface runoff for two different time periods: the first in the middle and the second at the end of the 21st century. The first results of the study showed that the surface runoff depends on the methodology used for the calculation of the evapotranspiration but also from the regional model. Acknowledgements: This study has been supported by the CC-WaterS project (Contract number SEE/A/022/2.1/X)